Firehol + Fireqos Reference

FireHOL + FireQOS Reference

FireHOL Team

Release 2.0.0-pre7 Built 13 Apr 2014 FireHOL + FireQOS Reference Release 2.0.0-pre7 i

Contents

1 Introduction 1 1.1 Latest version...... 1 1.2 Who should read this manual...... 1 1.3 Where to get help...... 1 1.4 Manual Organisation...... 1 1.5 Installation...... 2 1.6 Licence...... 2

I FireHOL3

2 Conﬁguration 4 2.1 Getting started...... 4 2.2 Language...... 4 2.2.1 Use of bash...... 4 2.2.1.1 What to avoid...... 4

3 Security 6 3.1 Important Security Note...... 6 3.2 What happens when FireHOL Runs?...... 6 3.3 Where to learn more...... 7

4 Troubleshooting 8 4.1 Reading log output...... 8 FireHOL + FireQOS Reference Release 2.0.0-pre7 iii

II FireQOS 11

5 Conﬁguration 12

III FireHOL Reference 13

6 Running and Configuring 14 6.1 FireHOL program: firehol...... 15 6.2 FireHOL configuration: firehol.conf...... 18 6.3 control variables: firehol-variables...... 23 6.4 ipv4/ipv6 selection: firehol-modifiers...... 31

7 Definition Commands 33 7.1 interface definition: firehol-interface...... 34 7.2 router definition: firehol-router...... 36

8 Rule Subcommands 39 8.1 policy command: firehol-policy...... 40 8.2 protection command: firehol-protection...... 41 8.3 server, route commands: firehol-server...... 44 8.4 client command: firehol-client...... 46 8.5 group command: firehol-group...... 48

9 Optional Parameters and Actions 50 9.1 optional rule parameters: ﬁrehol-rule-params...... 51 9.2 actions for rules: ﬁrehol-actions...... 57

10 Helper Commands 63 10.1 iptables helper: firehol-iptables...... 64 10.2 masquerade helper: firehol-masquerade...... 65 10.3 tcpmss helper: firehol-tcpmss...... 67 FireHOL + FireQOS Reference Release 2.0.0-pre7 iv

11 Configuration Helper Commands 68 11.1 version config helper: firehol-version...... 69 11.2 action config helper: firehol-action...... 70 11.3 blacklist config helper: firehol-blacklist...... 72 11.4 classify config helper: firehol-classify...... 73 11.5 connmark config helper: firehol-connmark...... 74 11.6 dscp config helper: firehol-dscp...... 76 11.7 mac config helper: firehol-mac...... 78 11.8 mark config helper: firehol-mark...... 79 11.9 nat, snat, dnat, redirect config helpers: firehol-nat...... 81 11.10transparent_proxy, transparent_squid helpers: firehol-transparent_proxy...... 84 11.11tos config helper: firehol-tos...... 86 11.12tosfix config helper: firehol-tosfix...... 88

12 Services Reference 89 12.1 services list: firehol-services...... 90 12.2 services list a: firehol-services-a...... 91 12.3 services list b: firehol-services-b...... 96 12.4 services list c: firehol-services-c...... 97 12.5 services list d: firehol-services-d...... 99 12.6 services list e: firehol-services-e...... 105 12.7 services list f: firehol-services-f...... 108 12.8 services list g: firehol-services-g...... 110 12.9 services list h: firehol-services-h...... 113 12.10services list i: firehol-services-i...... 117 12.11services list j: firehol-services-j...... 126 12.12services list k: firehol-services-k...... 128 12.13services list l: firehol-services-l...... 129 12.14services list m: firehol-services-m...... 132 12.15services list n: firehol-services-n...... 136 FireHOL + FireQOS Reference Release 2.0.0-pre7 v

12.16services list o: firehol-services-o...... 144 12.17services list p: firehol-services-p...... 146 12.18services list q: firehol-services-q...... 150 12.19services list r: firehol-services-r...... 151 12.20services list s: firehol-services-s...... 155 12.21services list t: firehol-services-t...... 163 12.22services list u: firehol-services-u...... 166 12.23services list v: firehol-services-v...... 168 12.24services list w: firehol-services-w...... 171 12.25services list x: firehol-services-x...... 173 12.26services list y: firehol-services-y...... 175 12.27services list z: firehol-services-z...... 176

IV FireQOS Reference 177

13 Running and Configuring 178 13.1 FireQOS program: fireqos...... 179 13.2 FireQOS configuration: fireqos.conf...... 181

14 Organising Traffic 184 14.1 interface definition: fireqos-interface...... 185 14.2 traffic class: fireqos-class...... 187 14.3 traffic match: fireqos-match...... 190

15 Optional Parameters 192 15.1 class/match parameters: fireqos-shared-params...... 193 15.2 optional class parameters: fireqos-class-params...... 194 15.3 optional match parameters: fireqos-match-params...... 199 FireHOL + FireQOS Reference Release 2.0.0-pre7 vi

V Appendices 203

A ICMPv6 Firewall Recommendations 204 A.1 Introduction...... 204 A.2 Allow outbound echo requests from preﬁxes which belong to the site...... 204 A.3 Allow inbound echo requests towards only predetermined hosts...... 204 A.4 Allow incoming and outgoing echo reply messages only for existing sessions...... 205 A.5 Deny icmps to/from link local addresses...... 205 A.6 Drop echo replies which have a multicast address as a destination...... 205 A.7 Allow incoming destination unreachable messages only for existing sessions...... 205 A.8 Allow outgoing destination unreachable messages...... 205 A.9 Allow incoming Packet Too Big messages only for existing sessions...... 206 A.10 Allow outgoing Packet Too Big messages...... 206 A.11 Allow incoming time exceeded code 0 messages only for existing sessions...... 206 A.12 Allow incoming time exceeded code 1 messages...... 206 A.13 Allow outgoing time exceeded code 0 messages...... 206 A.14 Allow outgoing time exceeded code 1 messages...... 206 A.15 Allow incoming parameter problem code 1 and 2 messages for an existing session.... 207 A.16 Allow outgoing parameter problem code 1 and code 2 messages...... 207 A.17 Allow incoming and outgoing parameter problem code 0 messages...... 207 A.18 Drop NS/NA messages both incoming and outgoing...... 207 A.19 Drop RS/RA messages both incoming and outgoing...... 207 A.20 Drop Redirect messages both incoming and outgoing...... 208 A.21 Drop incoming and outgoing Multicast Listener queries (MLDv1 and MLDv2)..... 208 A.22 Drop incoming and outgoing Multicast Listener reports (MLDv1)...... 208 A.23 Drop incoming and outgoing Multicast Listener Done messages (MLDv1)...... 209 A.24 Drop incoming and outgoing Multicast Listener reports (MLDv2)...... 209 A.25 Drop router renumbering messages...... 209 A.26 Drop node information queries (139) and replies (140)...... 210 A.27 If there are mobile ipv6 home agents present on the trusted side allow...... 210 A.28 If there are roaming mobile nodes present on the trusted side allow...... 210 A.29 Drop everything else...... 211 FireHOL + FireQOS Reference Release 2.0.0-pre7 vii

16 Index 212 FireHOL + FireQOS Reference Release 2.0.0-pre7 viii

List of Tables

6.1 iptables/klogd levels...... 25 FireHOL + FireQOS Reference Release 2.0.0-pre7 1 / 215

Chapter 1

Introduction

1.1 Latest version

The latest version of this document will always be available here. There are PDF and HTML versions.

1.2 Who should read this manual

This manual is aimed at those who wish to create and maintain ﬁrewalls with FireHOL or perform trafﬁc shaping with FireQOS. For more information and tutorials, see the FireHOL website.

1.3 Where to get help

The FireHOL website. The mailing lists and archives. The package comes with a complete set of manpages, a README and a brief INSTALL guide.

1.4 Manual Organisation

FireHOL, the package, consists of two principal programs. The manual is split into four parts. For ﬁrewalling read about FireHOL in PartI with reference material in Part III For trafﬁc shaping/QOS read about FireQOS in PartII with reference material in PartIV. FireHOL + FireQOS Reference Release 2.0.0-pre7 2 / 215

1.5 Installation

You can download tar-ﬁle releases by visiting the FireHOL website download area. Unpack and change directory with: tar xfz firehol-version.tar.gz cd firehol-version

Options for the conﬁgure program can be seen in the INSTALL ﬁle and by running: ./configure--help

To build and install taking the default options: ./configure&& make&& sudo make install

Alternatively, just copy the sbin/firehol.in and sbin/fireqos.in ﬁles to where you want them. All of the common SysVInit command line arguments are recognised which makes it easy to deploy the scripts as startup services. Packages are available for most distributions and you can use your distribution’s standard commands (e.g. aptitude, yum, etc.) to install these.

Note Distributions do not always offer the latest version. You can see what the latest release is on the FireHOL website.

1.6 Licence

This manual is licensed under the same terms as the FireHOL package, the GNU GPL v2 or later. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA FireHOL + FireQOS Reference Release 2.0.0-pre7 3 / 215

Part I

FireHOL FireHOL + FireQOS Reference Release 2.0.0-pre7 4 / 215

Chapter 2

Conﬁguration

2.1 Getting started

Please see the online tutorials for help getting started.

2.2 Language

2.2.1 Use of bash

FireHOL configuration files are normal BASH scripts. As such, you can use all BASH features within FireHOL configuration files, including functions, loops, variables, I/O, etc. BASH is used as the base configuration language for FireHOL since it is the common denominator for a language that all UNIX system administrators and developers should know and understand. The fact that FireHOL uses BASH for its configuration, allows development of add-ons and enables FireHOL to use programs to access SQL databases, directory structures, DBM or other files, web front ends or other means for the rules of the firewall. Exactly the same reason allows the build of remote managers for centralised administration of a large number of Linux hosts and routers.

2.2.1.1 What to avoid

The only BASH commands a FireHOL conﬁguration script should never use are trap and exit. FireHOL + FireQOS Reference Release 2.0.0-pre7 5 / 215

Traps are used by FireHOL for cleaning up all temporary files, and possibly restoring the previously running firewall in case FireHOL execution breaks, and the exit command will not just exit the configuration file, it will exit FireHOL. FireHOL has disabled these features by default, so that you will not be able to use them, unless you specifically enable them. Since a FireHOL configuration script runs inline with FireHOL, all variables and function names defined within the configuration file overwrite the ones defined by FireHOL so you should avoid some names. Avoid using variables that start with FIREHOL_, work_, server_, and client_ as many such variables are used by FireHOL internally. There are also a number of functions names you should avoid, but there is no generic pattern at the moment. I suggest you should avoid defining functions with the names of FireHOL commands (interface, router, client, server, etc) and functions starting with rules_.

Note You may wish to overwrite a few variables and functions if you want to modify FireHOL services. See the section called “Adding Services” for details. FireHOL + FireQOS Reference Release 2.0.0-pre7 6 / 215

Chapter 3

Security

This chapter discusses some of the security considerations of ﬁrewalls in general and using FireHOL in particular.

3.1 Important Security Note

It should be observed that FireHOL can be no more secure than your use of it. You should audit the output results at least once to ensure you are happy with the rules produced. The rules that get output are extremely regular and should make the task fairly straightforward. In particular it is your responsibility to ensure the final firewall produced behaves as you expect. If in doubt we recommend that you seek help from a firewall/networking professional. Please consider signing up to the mailing lists to ensure you are kept informed in the event that a security problem is discovered.

3.2 What happens when FireHOL Runs?

FireHOL is a BASH script. To run its configuration file, FireHOL first defines a set of functions and variables and then it "sources" (runs inline) its configuration file to be executed by BASH. The keywords interface, client, server, router, etc. are all BASH functions that are executed by BASH when and if they appear in the configuration file. Using shared variables these functions share some state information that allows them to know, for example, that a client command appears within an interface and not within a router and that the name given to an interface that has not been used before. FireHOL + FireQOS Reference Release 2.0.0-pre7 7 / 215

Instead of running iptables commands directly, each of these functions (i.e. FireHOL) just writes the generated iptables commands to a temporary file. This is done to prevent altering a running firewall before ensuring that the syntax of the configuration file is correct. So, a complete run of the configuration file actually produces all the iptables commands for the firewall, written to a temporary file (script). Even the iptables commands given within the configuration file use the same concept (they just generate iptables commands in this script). Finally, this script (the generated iptables commands) has to be run, but before doing so, FireHOL saves the running firewall to another temporary file. The saved firewall will be automatically restored if some of the generated iptables commands produces an error. Such an error is possible when for example, you specify an invalid IP address or hostname, or an invalid argument to some parameter that gets passed to iptables as-is. It is important to understand that during the run of the generated iptables script (including the possible restoration of the old firewall), FireHOL allows all traffic to reach its destination. This has been done to prevent a possible lock-out situation where you are SSHing to the server to alter its firewall, and suddenly you loose the connection (although this can still happen if your new firewall doesn’t allow the connection). To control this behaviour, set the ACTIVATION variables (see control variables: firehol-variables(5)). If no error has been seen, FireHOL deletes all temporary files generated and exits. In case there was an error, FireHOL will make the most to restore your previous firewall and will present you details about the error and its line number in the original configuration file.

3.3 Where to learn more

The FireHOL website contains more information and there are a number of iptables tutorials online. FireHOL + FireQOS Reference Release 2.0.0-pre7 8 / 215

Chapter 4

Troubleshooting

The main tool you have for troubleshooting a running ﬁrewall is the system log, typically /var/log/ syslog, /var/log/messages or similar.

4.1 Reading log output

The system log will log any packets dropped implicitly by FireHOL. This means any packets which do not match any rules in the configuration file. FireHOL always logs packets not matched by any rule, although it does not log every single packet, in order to protect you from an attack that could use all of your free hard disk space. The rate is controlled in the same way as loglimit. In the system log you will find entries that look like: Dec 21 20:01:07 gateway kernel:IN-internet:IN=ppp0 OUT= MAC= \ SRC=200.75.88.187 DST=195.97.5.193 LEN=78 TOS=0x00 PREC=0x00\ TTL=111ID=63816 PROTO=UDP SPT=34165 DPT=137 LEN=58

Dec 21 22:25:39 gateway kernel: OUT-unknown:IN= OUT=ppp0\ SRC=195.97.5.193 DST=192.168.23.1 LEN=48 TOS=0x00 PREC=0x00\ TTL=64ID=0DF PROTO=TCP SPT=139 DPT=1255 WINDOW=2128 \ RES=0x00 ACK SYN URGP=0

Dec 21 20:01:07 gateway kernel: PASS-unknown:IN=ppp0 OUT=eth0\ SRC=200.75.88.187 DST=195.97.5.194 LEN=78 TOS=0x00 PREC=0x00\ TTL=110ID=64840 PROTO=UDP SPT=34132 DPT=137 LEN=58

Each of such lines represent one packet that did not satisfy the requirements of the conﬁguration ﬁle rules. FireHOL + FireQOS Reference Release 2.0.0-pre7 9 / 215

FireHOL provides a reason text which indicates where a packet was dropped:

IN-name IN-name refers to packets that were dropped at the end of the interface definition called name’s input (see interface definition: firehol-interface(5)). These packets tried to come into this host (it is not routed traffic). There is also the special name unknown that matches packets which tried to come into this host but did not match any of the interfaces given in FireHOL’s configuration file.

OUT-name OUT-name refers to packets that were dropped at the end of the interface definition called name’s output (see interface definition: firehol-interface(5)). These are packets the host tried to send (it is not routed traffic). There is also the special name unknown that matches packets which tried to come into this host but did not match any of the interfaces given in FireHOL’s configuration file.

PASS-unknown PASS-unknown refers to packets that that were dropped at the end of all router definitions (see router definition: firehol-router(5)). This matches forwarded traffic. There is no name here, since all FireHOL routers have only one policy RETURN. All packets are processed against all routers and then get dropped at the end of the firewall.

Further information about the dropped packet is logged:

IN= The real network interface name the packet came in from. It can be empty when the packet was generated locally. OUT= The real network interface name the packet tried to use to go out of this host. It can be empty when the packet was received by the ﬁrewall host. SRC= The IP address of the packet’s sender. DST= The IP address of the packet’s destination. PROTO= The protocol this packet is using (TCP, UDP, ICMP, etc). SPT= The source port number of this packet. DPT= The destination port number of this packet. FireHOL + FireQOS Reference Release 2.0.0-pre7 10 / 215

Generally, you should monitor the system log for such entries and decide if each entry was something useful or not. If it was something useful, you should have added another service somewhere in your FireHOL configuration to match that packet and allow it to reach its destination. If it was not something useful, then FireHOL did the right job and dropped it. Keep in mind that there are certain cases where packets get dropped even though FireHOL has specific rules that should allow them to pass. Such cases are not always errors, and here is why: The iptables connection tracker has a mechanism for matching request packets and reply packets. When an allowed request comes in, the connection tracker keeps it in a list and then waits for a matching reply to come in the opposite direction. This list of active connections is available for you to see at /proc/net/ip_conntrack. Simply cat this file to see all the current connections your system has. The connection tracker will wait for a reply a certain amount of time. This time is, for example, about 20 seconds for UDP traffic. After that time the connection tracker will remove the request from its list. A reply that is send after the connection tracker has removed the request from its list, will be dropped and therefore logged in the system log. This situation may, for example, produce a few log entries in your DNS server for cases where the DNS server could not respond within the time limits set by iptables, but this is not a problem because the DNS client had already timed out in 2 or 3 seconds. Note however that the above are common when the connection tracker is trying to keep a state on a stateless protocol (such as UDP or ICMP). Stateful protocols, such as TCP, always respond immediately to acknowledge the connection and therefore the time needed by the application server to respond does not make the connection tracker to remove the request from its list. FireHOL + FireQOS Reference Release 2.0.0-pre7 11 / 215

Part II

FireQOS FireHOL + FireQOS Reference Release 2.0.0-pre7 12 / 215

Chapter 5

Conﬁguration

TODO FireHOL + FireQOS Reference Release 2.0.0-pre7 13 / 215

Part III

FireHOL Reference FireHOL + FireQOS Reference Release 2.0.0-pre7 14 / 215

Chapter 6

Running and Conﬁguring FireHOL + FireQOS Reference Release 2.0.0-pre7 15 / 215

6.1 FireHOL program: ﬁrehol

Name

ﬁrehol — an easy to use but powerful iptables stateful ﬁrewall

Synopsis firehol sudo -E firehol panic [IP] firehol command [ -- conf-arg... ] firehol CONFIGFILE [start | debug | try] [ -- conf-arg... ]

Description

Running firehol invokes iptables(8) to manipulate your firewall. Run without any arguments, firehol will present some help on usage. When given CONFIGFILE, firehol will use the named file instead of /etc/firehol/firehol. conf as its configuration. If no command is given, firehol assumes try. It is possible to pass arguments for use by the configuration file separating any conf-arg values from the rest of the arguments with --. The arguments are accessible in the configuration using standard bash(1) syntax e.g. $1, $2, etc.

Panic

To block all communication, invoke firehol with the panic command. FireHOL removes all rules from the running firewall and then DROPs all traffic on all iptables tables (mangle, nat, filter) and pre-defined chains (PREROUTING, INPUT, FORWARD, OUTPUT, POSTROUT- ING). DROPing is not done by changing the default policy to DROP, but by adding one rule per table/chain to drop all traffic. This allows systems which do not reset all the chains to ACCEPT when starting to function correctly. When activating panic mode, FireHOL checks for the existence of the SSH_CLIENT shell environment variable, which is set by ssh. If it finds this, then panic mode will allow the established SSH connection specified in this variable to operate. FireHOL + FireQOS Reference Release 2.0.0-pre7 16 / 215

Note In order for FireHOL to see the environment variable you must ensure that it is preserved. For sudo use the -E and for su omit the - (minus sign).

If SSH_CLIENT is not set, the IP after the panic argument allows you to give an IP address for which all established connections between the IP address and the host in panic will be allowed to continue.

Commands start, restart Activates the firewall configuration from /etc/firehol/firehol.conf. Use of the term restart is allowed for compatibility with common init implementations. try Activates the firewall, waiting for the user to type the word commit. If this word is not typed within 30 seconds, the previous firewall is restored. stop Stops a running iptables firewall by clearing all of the tables and chains and setting the default policies to ACCEPT. This will allow all traffic to pass unchecked. condrestart Restarts the FireHOL firewall only if it is already active. This is the generally expected behaviour (but opposite to FireHOL prior to 2.0.0-pre4). status Shows the running firewall, using /sbin/iptables -nxvL | less. save Start the firewall and then save it using /sbin/iptables-save to /etc/sysconfig/iptables. The required kernel modules are saved to an executable shell script /var/spool/firehol/ last_save_modules.sh, which can be called during boot if a firewall is to be restored.

Note External changes may cause a firewall restored after a reboot to not work as intended where starting the firewall with FireHOL will work. This is because as part of starting a firewall, FireHOL checks some changeable values. For instance the current kernel configuration is checked (for client port ranges), and RPC servers are queried (to allow correct functioning of the NFS service). debug Parses the configuration file but instead of activating it, FireHOL shows the generated iptables statements. FireHOL + FireQOS Reference Release 2.0.0-pre7 17 / 215 explain Enters an interactive mode where FireHOL accepts normal configuration commands and presents the generated iptables commands for each of them, together with some reasoning for its purpose. Additionally, FireHOL automatically generates a configuration script based on the successful commands given. Some extra commands are available in explain mode. SPECIALCOMMANDSINEXPLAINMODE help Present some help show Present the generated configuration quit Exit interactive mode and quit helpme, wizard Tries to guess the FireHOL configuration needed for the current machine. FireHOL will not stop or alter the running firewall. The configuration file is given in the standard output of firehol, thus firehol helpme > /tmp/firehol.conf will produce the output in /tmp/firehol.conf. The generated FireHOL configuration must be edited before use on your systems. You are required to take a number of decisions; the comments in the generated file will instruct you in the choices you must make.

Files

/etc/firehol/firehol.conf

See Also

FireHOL configuration: firehol.conf(5) control variables: firehol-variables(5) FireHOL Manual: firehol-manual.pdf FireHOL Online Documentation FireHOL + FireQOS Reference Release 2.0.0-pre7 18 / 215

6.2 FireHOL conﬁguration: ﬁrehol.conf

Name

firehol.conf — FireHOL configuration file

Description

/etc/firehol/firehol.conf is the default configuration file for FireHOL program: firehol(1). It defines the stateful firewall that will be produced. A configuration file starts with an optional version indicator which looks like this: version5

See version config helper: firehol-version(5) for full details. A configuration file contains one or more interface definitions, which look like this: interface eth0 lan client all accept# This host can access any remote service server ssh accept# Remote hosts can access SSH on local server # ...

The above definition has name "lan" and specifies a network interface (eth0). A definition may contain zero or more subcommands. See interface definition: firehol-interface(5) for full details. By default FireHOL will try to create both IPv4 and IPv6 rules for each interface. To make this explicit or restrict which rules are created write both interface, ipv4 interface or ipv6 interface. A configuration file contains zero or more router definitions, which look like this: DMZ_IF=eth0 WAN_IF=eth1 router wan2dmz inface${WAN_IF} outface${DMZ_IF} route http accept# Hosts on WAN may access HTTP on hosts in DMZ server ssh accept# Hosts on WAN may access SSH on hosts in DMZ client pop3 accept# Hosts in DMZ may access POP3 on hosts on WAN # ...

The above definition has name "wan2dmz" and specifies incoming and outgoing network interfaces (eth1 and eth0) using variables. A definition may contain zero or more subcommands. Note that a router is not required to specify network interfaces to operate on. See router definition: firehol-router(5) for full details. By default FireHOL will try to create both IPv4 and IPv6 rules for each router. To make this explicit or restrict which rules are created write both router, ipv4 router or ipv6 router. FireHOL + FireQOS Reference Release 2.0.0-pre7 19 / 215

It is simple to add extra service definitions which can then be used in the same way as those provided as standard. See the section called “Adding Services”. The configuration file is parsed as a bash(1) script, allowing you to set up and use variables, flow control and external commands. Special control variables: firehol-variables(5) may be set up and used outside of any definition as can the functions in the section called “Configuration Helper Commands” and the section called “Helper Commands”.

Variables Available

The following variables are made available in the FireHOL conﬁguration ﬁle and can be accessed as ${VARIABLE}.

UNROUTABLE_IPS This variable includes the IPs from both PRIVATE_IPS and RESERVED_IPS. It is useful to restrict trafﬁc on interfaces and routers accepting Internet trafﬁc, for example: interface eth0 internet src not"${UNROUTABLE_IPS}"

PRIVATE_IPS This variable includes all the IP addresses defined as Private or Test by RFC 3330. You can override the default values by creating a file called /etc/firehol/PRIVATE_IPS. RESERVED_IPS This variable includes all the IP addresses defined by IANA as reserved. You can override the default values by creating a file called /etc/firehol/RESERVED_IPS. Now that IPv4 address space has all been allocated there is very little reason that this value will need to change in future. MULTICAST_IPS This variable includes all the IP addresses defined as Multicast by RFC 3330. You can override the default values by creating a file called /etc/firehol/MULTICAST_IPS.

Adding Services

To define new services you add the appropriate lines before using them later in the configuration file. The following are required: server_myservice_ports="proto/sports" client_myservice_ports="cports" FireHOL + FireQOS Reference Release 2.0.0-pre7 20 / 215 proto is anything iptables(8) accepts e.g. "tcp", "udp", "icmp", including numeric protocol values. sports is the ports the server is listening at. It is a space-separated list of port numbers, names and ranges (from:to). The keyword any will match any server port. cports is the ports the client may use to initiate a connection. It is a space-separated list of port numbers, names and ranges (from:to). The keyword any will match any client port. The keyword default will match default client ports. For the local machine (e.g. a client within an interface) it resolves to sysctl variable net.ipv4.ip_local_port_range (or /proc/sys/net/ipv4/ip_local_port_ range). For a remote machine (e.g. a client within an interface or anything in a router) it resolves to the variable DEFAULT_CLIENT_PORTS (see control variables: firehol-variables(5)). The following are optional: require_myservice_modules="modules" require_myservice_nat_modules="nat-modules"

The named kernel modules will be loaded when the deﬁnition is used. The NAT modules will only be loaded if FIREHOL_NAT is non-zero (see control variables: ﬁrehol-variables(5)). For example, for a service named daftnet that listens at two ports, port 1234 TCP and 1234 UDP where the expected client ports are the default random ports a system may choose, plus the same port numbers the server listens at, with further dynamic ports requiring kernel modules to be loaded: version5 server_daftnet_ports="tcp/1234 udp/1234" client_daftnet_ports="default 1234" require_daftnet_modules="ip_conntrack_daftnet" require_daftnet_nat_modules="ip_nat_daftnet" interface eth0 lan0 server daftnet accept interface eth1 lan1 client daftnet reject router lan2lan inface eth0 outface eth1 route daftnet accept

Where multiple ports are provides (as per the example), FireHOL simply determines all of the combinations of client and server ports and generates multiple iptables statements to match them. To create more complex rules, or stateless rules, you will need to create a bash function preﬁxed rules_ e.g. rules_myservice. The best reference is the many such functions in the main ﬁrehol executable. When adding a service which uses modules, or via a custom function, you may also wish to include the following: FireHOL + FireQOS Reference Release 2.0.0-pre7 21 / 215

ALL_SHOULD_ALSO_RUN="${ALL_SHOULD_ALSO_RUN} myservice" which will ensure your service is set-up correctly as part of the all service.

Note To allow definitions to be shared you can instead create files and install them in the /etc/firehol/ services directory with a .conf extension. The first line must read: FHVER 1:213

1 is the service deﬁnition API version. It will be changed if the API is ever modiﬁed. The 213 originally referred to a FireHOL 1.x minor version but is no longer checked. FireHOL will refuse to run if the API version does not match the expected one.

Deﬁnitions

interface definition: firehol-interface(5) router definition: firehol-router(5)

Subcommands

policy command: firehol-policy(5) protection command: firehol-protection(5) server, route commands: firehol-server(5) client command: firehol-client(5) group command: firehol-group(5)

Helper Commands

These helpers can be used in interface and router definitions as well as before them. iptables helper: firehol-iptables(5) masquerade helper: firehol-masquerade(5) This helper can be used in router definitions as well as before any router or interface. tcpmss helper: firehol-tcpmss(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 22 / 215

Conﬁguration Helper Commands

These helpers should only be used outside of interface and router definitions (i.e. before the first interface is defined). version config helper: firehol-version(5) action config helper: firehol-action(5) blacklist config helper: firehol-blacklist(5) classify config helper: firehol-classify(5) connmark config helper: firehol-connmark(5) dscp config helper: firehol-dscp(5) mac config helper: firehol-mac(5) mark config helper: firehol-mark(5) nat, snat, dnat, redirect config helpers: firehol-nat(5) transparent_proxy, transparent_squid helpers: firehol-transparent_proxy(5) tos config helper: firehol-tos(5) tosfix config helper: firehol-tosfix(5)

See Also

FireHOL program: firehol(1) control variables: firehol-variables(5) services list: firehol-services(5) actions for rules: firehol-actions(5) FireHOL Manual: firehol-manual.pdf FireHOL Online Documentation FireHOL + FireQOS Reference Release 2.0.0-pre7 23 / 215

6.3 control variables: ﬁrehol-variables

Name

ﬁrehol-variables — Variables controlling FireHOL

Description

There are a number of variables that control the behaviour of FireHOL. All variables may be set in the main FireHOL configuration file /etc/firehol/firehol.conf. Variables which affect the runtime but not the created firewall may also be set as environment variables before running firehol. These can change the default values but will be overwritten by values set in the configuration file. If a variable can be set by an environment variable it is specified below. FireHOL also sets some variables before processing the configuration file which you can use as part of your configuration. These are described in FireHOL configuration: firehol.conf(5).

Variables

DEFAULT_INTERFACE_POLICY This variable controls the default action to be taken on trafﬁc not matched by any rule within an interface. It can be overridden using policy command: ﬁrehol-policy(5). Packets that reach the end of an interface without an action of return or accept are logged. You can control the frequency of this logging by altering FIREHOL_LOG_FREQUENCY. Default: DEFAULT_INTERFACE_POLICY="DROP"

Example: DEFAULT_INTERFACE_POLICY="REJECT"

DEFAULT_ROUTER_POLICY This variable controls the default action to be taken on trafﬁc not matched by any rule within a router. It can be overridden using policy command: ﬁrehol-policy(5). Packets that reach the end of a router without an action of return or accept are logged. You can control the frequency of this logging by altering FIREHOL_LOG_FREQUENCY. Default: DEFAULT_ROUTER_POLICY="RETURN" FireHOL + FireQOS Reference Release 2.0.0-pre7 24 / 215

Example: DEFAULT_ROUTER_POLICY="REJECT"

UNMATCHED_INPUT_POLICY, UNMATCHED_OUTPUT_POLICY, UNMATCHED_FORWARD_POLICY These variables control the default action to be taken on traffic not matched by any interface or router definition that was incoming, outgoing or for forwarding respectively. Any supported value from actions for rules: firehol-actions(5) may be set. All packets that reach the end of a chain are logged, regardless of these settings. You can control the frequency of this logging by altering FIREHOL_LOG_FREQUENCY. Defaults: UNMATCHED_INPUT_POLICY="DROP" UNMATCHED_OUTPUT_POLICY="DROP" UNMATCHED_FORWARD_POLICY="DROP"

Example: UNMATCHED_INPUT_POLICY="REJECT" UNMATCHED_OUTPUT_POLICY="REJECT" UNMATCHED_FORWARD_POLICY="REJECT"

FIREHOL_INPUT_ACTIVATION_POLICY, FIREHOL_OUTPUT_ACTIVATION_POLICY, FIREH OL_FORWARD_ACTIVATION_POLICY These variables control the default action to be taken on traffic during firewall activation for incoming, outgoing and forwarding respectively. Acceptable values are ACCEPT, DROP and REJECT. They may be set as environment variables. FireHOL defaults all values to ACCEPT so that your communications continue to work uninter- rupted. If you wish to prevent connections whilst the new firewall is activating, set these values to DROP. This is important to do if you are using all or any to match traffic; connections established during activation will continue even if they would not be allowed once the firewall is established. Defaults: UNMATCHED_INPUT_POLICY="ACCEPT" UNMATCHED_OUTPUT_POLICY="ACCEPT" UNMATCHED_FORWARD_POLICY="ACCEPT"

Example: FIREHOL_INPUT_ACTIVATION_POLICY="DROP" FIREHOL_OUTPUT_ACTIVATION_POLICY="DROP" FIREHOL_FORWARD_ACTIVATION_POLICY="DROP" FireHOL + FireQOS Reference Release 2.0.0-pre7 25 / 215

FIREHOL_LOG_MODE This variable controls method that FireHOL uses for logging. Acceptable values are LOG (normal syslog) and ULOG (netﬁlter ulogd). When ULOG is selected, FIREHOL_LOG_LEVEL is ignored. Default: FIREHOL_LOG_MODE="LOG"

Example: FIREHOL_LOG_MODE="ULOG"

To see the available options run: /sbin/iptables -j LOG --help or /sbin/iptables -j ULOG --help FIREHOL_LOG_LEVEL This variable controls the level at which events will be logged to syslog. To avoid packet logs appearing on your console you should ensure klogd only logs trafﬁc that is more important than that produced by FireHOL. Use the following option to choose an iptables log level (alpha or numeric) which is higher than the -c of klogd.

iptables klogd description emerg (0) 0 system is unusable alert (1) 1 action must be taken immediately crit (2) 2 critical conditions error (3) 3 error conditions warning (4) 4 warning conditions notice (5) 5 normal but signiﬁcant condition info (6) 6 informational debug (7) 7 debug-level messages

Table 6.1: iptables/klogd levels

Note The default for klogd is generally to log everything (7 and lower) and the default level for iptables is to log as warnings (4).

FIREHOL_LOG_OPTIONS This variable controls the way in which events will be logged to syslog. Default: FireHOL + FireQOS Reference Release 2.0.0-pre7 26 / 215

FIREHOL_LOG_OPTIONS="--log-level warning"

Example: FIREHOL_LOG_OPTIONS="--log-level info\ --log-tcp-options--log-ip-options"

To see the available options run: /sbin/iptables -j LOG --help FIREHOL_LOG_FREQUENCY, FIREHOL_LOG_BURST These variables control the frequency that each logging rule will write events to syslog. FIRE HOL_LOG_FREQUENCY is set to the maximum average frequency and FIREHOL_LOG_BURST speciﬁes the maximum initial number. Default: FIREHOL_LOG_FREQUENCY="1/second" FIREHOL_LOG_BURST="5"

Example: FIREHOL_LOG_FREQUENCY="30/minute" FIREHOL_LOG_BURST="2"

To see the available options run: /sbin/iptables -m limit --help FIREHOL_LOG_PREFIX This value is added to the contents of each logged line for easy detection of FireHOL lines in the system logs. By default it is empty. Default: FIREHOL_LOG_PREFIX=""

Example: FIREHOL_LOG_PREFIX="FIREHOL:"

FIREHOL_DROP_INVALID If set to 1, this variable causes FireHOL to drop all packets matched as INVALID in the iptables(8) connection tracker.

Note You can use protection command: ﬁrehol-protection(5) to control matching of INVALID packets and others on per-interface and per-router basis. FireHOL + FireQOS Reference Release 2.0.0-pre7 27 / 215

Default: FIREHOL_DROP_INVALID="0"

Example: FIREHOL_DROP_INVALID="1"

DEFAULT_CLIENT_PORTS This variable controls the port range that is used when a remote client is speciﬁed. For clients on the local host, FireHOL ﬁnds the exact client ports by querying the kernel options. Default: DEFAULT_CLIENT_PORTS="1000:65535"

Example: DEFAULT_CLIENT_PORTS="0:65535"

FIREHOL_NAT If set to 1, this variable causes FireHOL to load the NAT kernel modules. If you make use of the NAT helper commands, the variable will be set to 1 automatically. It may be set as an environment variable. Default: FIREHOL_NAT="0"

Example: FIREHOL_NAT="1"

FIREHOL_ROUTING If set to 1, this variable causes FireHOL to enable routing in the kernel. If you make use of router deﬁnitions or certain helper commands the variable will be set to 1 automatically. It may be set as an environment variable. Default: FIREHOL_ROUTING="0"

Example: FIREHOL_ROUTING="1" FireHOL + FireQOS Reference Release 2.0.0-pre7 28 / 215

FIREHOL_AUTOSAVE This variable specifies the file of (IPv4) rules that will be created when FireHOL program: firehol(1) is called with the save argument. It may be set as an environment variable. If the variable is not set, a system-specific value is used which was defined at configure-time. If no value was chosen then the save fails. Default: FIREHOL_AUTOSAVE=""

Example: FIREHOL_AUTOSAVE="/tmp/firehol-saved-ipv4.txt"

FIREHOL_LOAD_KERNEL_MODULES If set to 0, this variable forces FireHOL to not load any kernel modules. It is needed only if the kernel has modules statically included and in the rare event that FireHOL cannot access the kernel conﬁguration. It may be set as an environment variable. Default: FIREHOL_LOAD_KERNEL_MODULES="1"

Example: FIREHOL_LOAD_KERNEL_MODULES="0"

FIREHOL_TRUST_LOOPBACK If set to 0, the loopback device "lo" will not be trusted and you can write standard ﬁrewall rules for it.

Warning If you do not set up appropriate rules, local processes will not be able to communicate with each other which can result in serious breakages.

By default "lo" is trusted and all INPUT and OUTPUT trafﬁc is accepted (forwarding is not included). Default: FIREHOL_TRUST_LOOPBACK="1"

Example: FIREHOL_TRUST_LOOPBACK="0" FireHOL + FireQOS Reference Release 2.0.0-pre7 29 / 215

FIREHOL_DROP_ORPHAN_TCP_ACK_FIN If set to 1, FireHOL will drop all TCP connections with ACK FIN set without logging them. In busy environments the iptables connection tracker removes connection tracking list entries as soon as it receives a FIN. This makes the ACK FIN appear as an invalid packet which will normally be logged by FireHOL. Default: FIREHOL_DROP_ORPHAN_TCP_ACK_FIN="0"

Example: FIREHOL_DROP_ORPHAN_TCP_ACK_FIN="1"

FIREHOL_DEBUGGING If set to a non-empty value, switches on debug output so that it is possible to see what processing FireHOL is doing.

Note This variable can only be set as an environment variable, since it is processed before any con- ﬁguration ﬁles are read.

Default: FIREHOL_DEBUGGING=""

Example: FIREHOL_DEBUGGING="Y"

WAIT_FOR_IFACE If set to the name of a network device (e.g. eth0), FireHOL will wait until the device is up (or until 60 seconds have elapsed) before continuing.

Note This variable can only be set as an environment variable, since it determines when the main conﬁguration ﬁle will be processed.

A device does not need to be up in order to have firewall rules created for it, so this option should only be used if you have a specific need to wait (e.g. the network must be queried to determine the hosts or ports which will be firewalled). Default: FireHOL + FireQOS Reference Release 2.0.0-pre7 30 / 215

WAIT_FOR_IFACE=""

Example: WAIT_FOR_IFACE="eth0"

See Also

FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) interface definition: firehol-interface(5) router definition: firehol-router(5) policy command: firehol-policy(5) protection command: firehol-protection(5) client command: firehol-client(5) server, route commands: firehol-server(5) group command: firehol-group(5) iptables helper: firehol-iptables(5) masquerade helper: firehol-masquerade(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 33 / 215

Chapter 7

Deﬁnition Commands FireHOL + FireQOS Reference Release 2.0.0-pre7 34 / 215

7.1 interface deﬁnition: ﬁrehol-interface

Name

firehol-interface, firehol-interface4, firehol-interface6, firehol-interface46 — create an interface definition

Synopsis interface|interface46 real-interface name [rule-params] interface4 real-interface name [rule-params] interface6 real-interface name [rule-params]

Description

An interface definition creates a firewall for protecting the host on which the firewall is running. The default policy is DROP, so that if no subcommands are given, the firewall will just drop all incoming and outgoing traffic using this interface. The behaviour of the defined interface is controlled by adding subcommands (listed in the section called “See Also”).

Note Forwarded traffic is never matched by the interface rules, even if it was originally destined for the firewall but was redirected using NAT. Any traffic to be passed through the firewall for whatever reason must be in a router (see router definition: firehol-router(5)).

Note Writing interface4 is equivalent to writing ipv4 interface and ensures the defined interface is created only in the IPv4 firewall along with any rules within it. Writing interface6 is equivalent to writing ipv6 interface and ensures the defined interface is created only in the IPv6 firewall along with any rules within it. Writing interface46 is equivalent to writing both interface and ensures the defined interface is created in both the IPv4 and IPv6 firewalls. Any rules within it will also be applied to both, unless they specify otherwise. FireHOL + FireQOS Reference Release 2.0.0-pre7 35 / 215

Parameters real-interface This is the interface name as shown by ip link show. Generally anything iptables accepts is valid. The + (plus sign) after some text will match all interfaces that start with this text. Multiple interfaces may be specified by enclosing them within quotes, delimited by spaces for example: interface"eth0 eth1 ppp0" myname name This is a name for this interface. You should use short names (10 characters maximum) without spaces or other symbols. A name should be unique for all FireHOL interface and router definitions. rule-params The set of rule parameters to further restrict the traffic that is matched to this interface. See optional rule parameters: firehol-rule-params(5) for information on the parameters that can be used. Some examples: interface eth0 intranet src 192.0.2.0/24

interface eth0 internet src not"${UNROUTABLE_IPS}"

See FireHOL conﬁguration: ﬁrehol.conf(5) for an explanation of ${UNROUTABLE_IPS}.

See Also

FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) ipv4/ipv6 selection: firehol-modifiers(5) router definition: firehol-router(5) policy command: firehol-policy(5) protection command: firehol-protection(5) client command: firehol-client(5) server, route commands: firehol-server(5) group command: firehol-group(5) iptables helper: firehol-iptables(5) masquerade helper: firehol-masquerade(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 36 / 215

7.2 router deﬁnition: ﬁrehol-router

Name

firehol-router, firehol-router4, firehol-router6, firehol-router46 — create a router definition

Synopsis router|router46 name [rule-params] router4 name [rule-params] router6 name [rule-params]

Description

A router definition consists of a set of rules for traffic passing through the host running the firewall. The default policy for router definitions is RETURN, meaning packets are not dropped by any particular router. Packets not matched by any router are dropped at the end of the firewall. The behaviour of the defined router is controlled by adding subcommands (listed in the section called “See Also”).

Note Writing router4 is equivalent to writing ipv4 router and ensures the defined router is created only in the IPv4 firewall along with any rules within it. Writing router6 is equivalent to writing ipv6 router and ensures the defined router is created only in the IPv6 firewall along with any rules within it. Writing router46 is equivalent to writing both router and ensures the defined router is created in both the IPv4 and IPv6 firewalls. Any rules within it will also be applied to both, unless they specify otherwise.

Parameters name This is a name for this router. You should use short names (10 characters maximum) without spaces or other symbols. A name should be unique for all FireHOL interface and router deﬁnitions. FireHOL + FireQOS Reference Release 2.0.0-pre7 37 / 215

rule-params The set of rule parameters to further restrict the trafﬁc that is matched to this router. See optional rule parameters: ﬁrehol-rule-params(5) for information on the parameters that can be used. Some examples: router mylan inface ppp+ outface eth0 src not${UNROUTABLE_IPS}

router myrouter

See FireHOL conﬁguration: ﬁrehol.conf(5) for an explanation of ${UNROUTABLE_IPS}.

Working with routers

Routers create stateful iptables rules which match traffic in both directions. To match some client or server traffic, the input/output interface or source/destination of the request must be specified. All inface/outface and src/dst optional rule parameters: firehol-rule-params(5) can be given on the router statement (in which case they will be applied to all subcommands for the router) or just within the subcommands of the router. For example, to define a router which matches requests from any PPP interface and destined for eth0, and on this allowing HTTP servers (on eth0) to be accessed by clients (from PPP) and SMTP clients (from eth0) to access any servers (on PPP): router mylan inface ppp+ outface eth0 server http accept client smtp accept

Note The client subcommand reverses any optional rule parameters passed to the router, in this case the inface and outface.

Equivalently, to deﬁne a router which matches all forwarded trafﬁc and within the the router allow HTTP servers on eth0 to be accessible to PPP and any SMTP servers on PPP to be accessible from eth0: router mylan server http accept inface ppp+ outface eth0 server smtp accept inface eth0 outface ppp

Note In this instance two server subcommands are used since there are no parameters on the router to reverse. Avoid the use of the client subcommand in routers unless the inputs and outputs are deﬁned as part of the router. FireHOL + FireQOS Reference Release 2.0.0-pre7 38 / 215

Any number of routers can be defined and the traffic they match can overlap. Since the default policy is RETURN, any traffic that is not matched by any rules in one will proceed to the next, in order, until none are left.

See Also

FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) ipv4/ipv6 selection: firehol-modifiers(5) interface definition: firehol-interface(5) policy command: firehol-policy(5) protection command: firehol-protection(5) client command: firehol-client(5) server, route commands: firehol-server(5) group command: firehol-group(5) iptables helper: firehol-iptables(5) masquerade helper: firehol-masquerade(5) tcpmss helper: firehol-tcpmss(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 39 / 215

Chapter 8

Rule Subcommands FireHOL + FireQOS Reference Release 2.0.0-pre7 40 / 215

8.1 policy command: ﬁrehol-policy

Name

ﬁrehol-policy — set default action for a deﬁnition

Synopsis policy action

Description

The policy subcommand deﬁnes the default policy for an interface or router. The action can be any of the actions listed in actions for rules: ﬁrehol-actions(5).

Note Change the default policy of a router only if you understand clearly what will be matched by the router statement whose policy is being changed. It is common to define overlapping router definitions. Changing the policy to anything other than the default return may cause strange results for your configuration.

Warning Do not set a policy to accept unless you fully trust all hosts that can reach the interface. FireHOL CANNOT create valid "accept by default" ﬁrewalls.

See Also

FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) interface definition: firehol-interface(5) actions for rules: firehol-actions(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 41 / 215

8.2 protection command: ﬁrehol-protection

Name

ﬁrehol-protection — add extra protections to a deﬁnition

Synopsis protection [reverse] flood-protection-type [requests/period [burst]] protection [reverse] strong [requests/period [burst]] protection [reverse] bad-packets | packet-protection-type

Description

The protection subcommand sets protection rules on an interface or router. Flood protections honour the options requests/period and burst. They are used to limit the rate of certain types of traffic. The default rate FireHOL uses is 100 operations per second with a burst of 50. Run iptables -m limit --help for more information. The protection type strong will switch on all protections (both packet and flood protections) except all-floods. It has aliases full and all. The protection type bad-packets will switch on all packet protections but not flood protections. You can specify multiple protection types by using multiple protection commands or in a single command by enclosing the types in quotes.

Note On a router, protections are normally set up on inface. The reverse option will set up the protections on outface. You must use it as the ﬁrst keyword.

Packet protection types invalid Drops all incoming invalid packets, as detected INVALID by the connection tracker. See also FIREHOL_DROP_INVALID in control variables: firehol-variables(5) which allows setting this function globally. FireHOL + FireQOS Reference Release 2.0.0-pre7 42 / 215 fragments Drops all packet fragments. This rule will probably never match anything since iptables(8) reconstructs all packets automatically before the firewall rules are processed whenever connection tracking is running. new-tcp-w/o-syn Drops all TCP packets that initiate a socket but have not got the SYN flag set. malformed-xmas Drops all TCP packets that have all TCP flags set. malformed-null Drops all TCP packets that have all TCP flags unset. malformed-bad Drops all TCP packets that have illegal combinations of TCP flags set.

Flood protection types icmp-floods [requests/period [burst]] Allows only a certain amount of ICMP echo requests. syn-floods [requests/period [burst]] Allows only a certain amount of new TCP connections. Be careful to not set the rate too low as the rule is applied to all connections regardless of their final result (rejected, dropped, established, etc). all-floods [requests/period [burst]] Allows only a certain amount of new connections. Be careful to not set the rate too low as the rule is applied to all connections regardless of their final result (rejected, dropped, established, etc).

Examples protection strong protection"invalid new-tcp-w/o-syn" protection syn-floods 90/sec 40 FireHOL + FireQOS Reference Release 2.0.0-pre7 43 / 215

Bugs

When using multiple types in a single command, if the quotes are forgotten, incorrect rules will be generated without warning. When using multiple types in a single command, FireHOL will silently ignore any types that come after a group type (bad-packets, strong and its aliases). Only use group types on their own line.

See Also

FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) interface definition: firehol-interface(5) router definition: firehol-router(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 44 / 215

8.3 server, route commands: ﬁrehol-server

Name

firehol-server, firehol-server4, firehol-server6, firehol-server46, firehol-route, firehol-route4, firehol-route6, firehol-route46 — accept requests to a service

Description

The server subcommand defines a server of a service on an interface or router. Any rule-params given to a parent interface or router are inherited by the server. For FireHOL a server is the destination of a request. Even though this is more complex for some multi- socket services, to FireHOL a server always accepts requests. The route subcommand is an alias for server which may only be used in routers. The service parameter is one of the supported service names from services list: firehol-services(5). Multiple services may be specified, space delimited in quotes. The action can be any of the actions listed in actions for rules: firehol-actions(5). The rule-params define a set of rule parameters to further restrict the traffic that is matched to this service. See optional rule parameters: firehol-rule-params(5) for more details.

Note Writing server4 is equivalent to writing ipv4 server and ensures this subcommand is applied only in the IPv4 firewall rules. Writing server6 is equivalent to writing ipv6 server and ensures this subcommand is applied only in the IPv6 firewall rules. Writing server46 is equivalent to writing both server and ensures this subcommand is applied in both the IPv4 and IPv6 firewall rules; it cannot be used as part an interface or router that is IPv4 or IPv6 only. The default server inherits its behaviour from the enclosing interface or router. The same rules apply to the variations of route. FireHOL + FireQOS Reference Release 2.0.0-pre7 45 / 215

Examples server smtp accept server"smtp pop3" accept server smtp accept src 192.0.2.1 server smtp accept log"mail packet" src 192.0.2.1

See Also

FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) ipv4/ipv6 selection: firehol-modifiers(5) interface definition: firehol-interface(5) router definition: firehol-router(5) services list: firehol-services(5) actions for rules: firehol-actions(5) optional rule parameters: firehol-rule-params(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 46 / 215

8.4 client command: ﬁrehol-client

Name

firehol-client, firehol-client4, firehol-client6, firehol-client46 — accept replies from a service

Synopsis client|client46|client4|client6 service action [rule-params]

Description

The client subcommand defines a client of a service on an interface or router. Any rule-params given to a parent interface or router are inherited by the client, but are reversed. For FireHOL a client is the source of a request. Even though this is more complex for some multi-socket services, to FireHOL a client always initiates the connection. The service parameter is one of the supported service names from services list: firehol-services(5). Multiple services may be specified, space delimited in quotes. The action can be any of the actions listed in actions for rules: firehol-actions(5). The rule-params define a set of rule parameters to further restrict the traffic that is matched to this service. See optional rule parameters: firehol-rule-params(5) for more details.

Note Writing client4 is equivalent to writing ipv4 client and ensures this subcommand is applied only in the IPv4 firewall rules. Writing client6 is equivalent to writing ipv6 client and ensures this subcommand is applied only in the IPv6 firewall rules. Writing client46 is equivalent to writing both client and ensures this subcommand is applied in both the IPv4 and IPv6 firewall rules; it cannot be used as part an interface or router that is IPv4 or IPv6 only. The default server inherits its behaviour from the enclosing interface or router.

Examples client smtp accept client"smtp pop3" accept FireHOL + FireQOS Reference Release 2.0.0-pre7 47 / 215

client smtp accept src 192.0.2.1 client smtp accept log"mail packet" src 192.0.2.1

See Also

8.5 group command: ﬁrehol-group

Name

ﬁrehol-group — group commands with common options

Synopsis group with [rule-params] group end

Description

The group command allows you to group together multiple client and server commands. Grouping commands with common options (see optional rule parameters: firehol-rule-params(5)) allows the option values to be checked only once in the generated firewall rather than once per service, making it more efficient. Nested groups may be used.

Examples

This: interface any world client all accept server http accept

# Provide these services to trusted hosts only server"ssh telnet" accept src "192.0.2.1 192.0.2.2" can be replaced to produce a more efﬁcient ﬁrewall by this: interface any world client all accept server http accept

# Provide these services to trusted hosts only group with src "192.0.2.1 192.0.2.2" server telnet accept server ssh accept group end FireHOL + FireQOS Reference Release 2.0.0-pre7 49 / 215

See Also

FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) interface definition: firehol-interface(5) router definition: firehol-router(5) optional rule parameters: firehol-rule-params(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 50 / 215

Chapter 9

Optional Parameters and Actions FireHOL + FireQOS Reference Release 2.0.0-pre7 51 / 215

9.1 optional rule parameters: ﬁrehol-rule-params

Name

firehol-rule-params, firehol-src, firehol-src4, firehol-src6, firehol-dst, firehol-dst4, firehol-dst6, firehol- srctype, firehol-dsttype, firehol-dport, firehol-sport, firehol-inface, firehol-outface, firehol-physin, firehol- physout, firehol-custom, firehol-log, firehol-loglimit, firehol-proto, firehol-uid, firehol-gid, firehol-mac- param, firehol-mark-param, firehol-tos-param, firehol-dscp-param, firehol-dport, firehol-sport — optional rule parameters

Synopsis

Common src|src4|src6 [not] host dst|dst4|dst6 [not] host srctype [not] type dsttype [not] type proto [not] protocol mac [not] macaddr dscp [not] value | class classid mark [not] id tos [not] id custom "iptables-options..." Router Only inface [not] interface outface [not] interface physin [not] interface physout [not] interface Interface Only uid [not] user gid [not] group Logging FireHOL + FireQOS Reference Release 2.0.0-pre7 52 / 215 log "log text" [level loglevel] loglimit "log text" [level loglevel] Other sport port(s) dport port(s)

Description

Optional rule parameters are accepted by many commands to narrow the match they make. Not all parameters are accepted by all commands so you should check the individual commands for exclusions. All matches are made against the REQUEST. FireHOL automatically sets up the necessary stateful rules to deal with replies in the reverse direction. Use the option not to match any value other than the one(s) speciﬁed. The logging parameters are unusual in that they do not affect the match, they just cause a log message to be emitted. Therefore, the logging parameters don’t support the not option. FireHOL is designed so that if you specify a parameter that is also used internally by the command then a warning will be issued (and the internal version will be used).

Common

Use src and dst to deﬁne the source and destination IP addresses of the request respectively. host deﬁnes the IP or IPs to be matched. Examples: server4 smtp accept src not 192.0.2.1 server4 smtp accept dst 198.51.100.1 server4 smtp accept src not 192.0.2.1 dst 198.51.100.1 server6 smtp accept src not 2001:DB8:1::/64 server6 smtp accept dst 2001:DB8:2::/64 server6 smtp accept src not 2001:DB8:1::/64 dst 2001:DB8:2::/64

When attempting to create rules for both IPv4 and IPv6 it is generally easier to use the src4, src6, dst4 and dst6 pairs: server46 smtp accept src4 192.0.2.1 src6 2001:DB8:1::/64 server46 smtp accept dst4 198.51.100.1 dst6 2001:DB8:2::/64 server46 smtp accept dst4 $d4 dst6 $d6 src4 not $d4 src6 not $s6

To keep the rules sane, if one of the 4/6 pair speciﬁes not, then so must the other. If you do not want to use both IPv4 and IPv6 addresses, you must specify the rule as IPv4 or IPv6 only. It is always possible to write a second IPv4 or IPv6 only rule. FireHOL + FireQOS Reference Release 2.0.0-pre7 53 / 215

Use srctype or dsttype to deﬁne the source or destination IP address type of the request. type is the address type category as used in the kernel’s network stack. It can be one of:

UNSPEC an unspeciﬁed address (i.e. 0.0.0.0) UNICAST a unicast address LOCAL a local address BROADCAST a broadcast address ANYCAST an anycast address MULTICAST a multicast address BLACKHOLE a blackhole address UNREACHABLE an unreachable address PROHIBIT a prohibited address THROW, NAT, XRESOLVE undocumented

See iptables(8) or run iptables -m addrtype --help for more information. Examples: server smtp accept srctype not"UNREACHABLE PROHIBIT"

Use proto to match by protocol. The protocol can be any accepted by iptables(8). Use mac to match by MAC address. The macaddr matches to the "remote" host. In an interface, "remote" always means the non-local host. In a router, "remote" refers to the source of requests for servers. It refers to the destination of requests for clients. Examples: # Only allow pop3 requests to the e6 host client pop3 accept mac 00:01:01:00:00:e6

# Only allow hosts other than e7/e8 to access smtp server smtp accept mac not "00:01:01:00:00:e7 00:01:01:00:00:e8" FireHOL + FireQOS Reference Release 2.0.0-pre7 54 / 215

Use dscp to match the DSCP field on packets. For details on DSCP values and classids, see dscp config helper: firehol-dscp(5). server smtp accept dscp not "0x200x30" server smtp accept dscp not class"BEEF"

Use mark to match marks set on packets. For details on mark ids, see mark conﬁg helper: ﬁrehol- mark(5). server smtp accept mark not "20 55"

Use tos to match the TOS field on packets. For details on TOS ids, see tos config helper: firehol-tos(5). server smtp accept tos not"Maximize-Throughput0x10"

Use custom to pass arguments directly to iptables(8). All of the parameters must be in a single quoted string. To pass an option to iptables(8) that itself contains a space you need to quote strings in the usual bash(1) manner. For example: server smtp accept custom "--some-option some-value" server smtp accept custom "--some-option’some-value second-value’"

Router Only

Use inface and outface to define the interface via which a request is received and forwarded respectively. Use the same format as interface definition: firehol-interface(5). Examples: server smtp accept inface not eth0 server smtp accept inface not"eth0 eth1" server smtp accept inface eth0 outface eth1

Use physin and physout to define the physical interface via which a request is received or send in cases where the inface or outface is known to be a virtual interface; e.g. a bridge. Use the same format as interface definition: firehol-interface(5). Examples: server smtp accept physin not eth0

Interface only

These parameters match information related to information gathered from the local host. They apply only to outgoing packets and are silently ignored for incoming requests and requests that will be forwarded. Use uid to match the operating system user sending the trafﬁc. The user is a username, uid number or a quoted list of the two. For example, to limit which users can access POP3 and IMAP by preventing replies for certain users from being sent: FireHOL + FireQOS Reference Release 2.0.0-pre7 55 / 215

client"pop3 imap" accept user not"user1 user2 user3"

Similarly, this will allow all requests to reach the server but prevent replies unless the web server is running as apache: server http accept user apache

Use gid to match the operating system group sending the trafﬁc. The group is a group name, gid number or a quoted list of the two.

Note The Linux kernel infrastructure to match PID/SID and executable names with pid, sid and cmd has been removed so these options can no longer be used.

Logging

Use log or loglimit to log matching packets to syslog. Unlike iptables(8) logging, this is not an action: FireHOL will produce multiple iptables commands to accomplish both the action for the rule and the logging. Logging is controlled using the FIREHOL_LOG_OPTIONS and FIREHOL_LOG_LEVEL environment variables (see control variables: ﬁrehol-variables(5)). loglimit additionally honours the FIREHOL_LOG _FREQUENCY and FIREHOL_LOG_BURST variables. Specifying level (which takes the same values as FIREHOL_LOG_LEVEL) allows you to override the log level for a single rule.

Lesser used parameters

FireHOL also provides dport, sport and limit which are used internally and rarely needed within configuration files. dport requires an argument port which can be a name, number, range (FROM:TO) or a quoted list of ports. It specifies the destination port of a request and can be useful when matching traffic to helper commands (such as nat) where there is no implicit port. sport requires an argument port which can be a name, number, range (FROM:TO) or a quoted list of ports. It specifies the source port of a request and can be useful when matching traffic to helper commands (such as nat) where there is no implicit port. limit requires the arguments frequency and burst and will limit the matching of traffic in both directions. FireHOL + FireQOS Reference Release 2.0.0-pre7 56 / 215

See Also

FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) client command: firehol-client(5) server, route commands: firehol-server(5) interface definition: firehol-interface(5) router definition: firehol-router(5) mark config helper: firehol-mark(5) tos config helper: firehol-tos(5) dscp config helper: firehol-dscp(5) control variables: firehol-variables(5) administration tool for IPv4 firewalls: iptables(8) FireHOL + FireQOS Reference Release 2.0.0-pre7 57 / 215

9.2 actions for rules: ﬁrehol-actions

Name

firehol-actions, firehol-accept, firehol-deny, firehol-drop, firehol-reject, firehol-return, firehol-tarpit — rule actions

Synopsis accept accept with limit requests/period burst [ overﬂow action ] accept with recent name seconds hits accept with knock name reject [ with message ] drop deny return tarpit

Description

These actions are the actions to be taken on trafﬁc that has been matched by a particular rule. FireHOL will also pass through any actions that iptables(8) accepts, however these deﬁnitions provide lowercase versions which accept arguments where appropriate and which could otherwise not be passed through.

Note The iptables(8) LOG action is best used through the optional rule parameter log since the latter can be combined with one of these actions (FireHOL will generate multiple ﬁrewall rules to make this happen). For information on log and loglimit, see optional rule parameters: ﬁrehol-rule-params(5).

The following actions are defined: accept accept allows the traffic matching the rules to reach its destination. For example, to allow SMTP requests and their replies to flow: FireHOL + FireQOS Reference Release 2.0.0-pre7 58 / 215

server smtp accept accept with limit accept with limit allows the trafﬁc, with new connections limited to requests/period with a maximum burst. Run iptables -m limit --help for more information. The default overflow action is to REJECT the excess connections (DROP would produce timeouts on otherwise valid service clients). Examples: server smtp accept with limit 10/sec 100

server smtp accept with limit 10/sec 100 overflow drop accept with recent accept with recent allows the trafﬁc matching the rules to reach its destination, limited per remote IP to hits per seconds. Run iptables -m recent --help for more information. The name parameter is used to allow multiple rules to share the same table of recent IPs. For example, to allow only 2 connections every 60 seconds per remote IP, to the smtp server: server smtp accept with recent mail 60 2

Note When a new connection is not allowed, the traffic will continue to be matched by the rest of the firewall. In other words, if the traffic is not allowed due to the limitations set here, it is not dropped, it is just not matched by this rule. accept with knock accept with knock allows easy integration with knockd, a server that allows you to control access to services by sending certain packets to "knock" on the door, before the door is opened for service. The name is used to build a special chain knock_ which contains rules to allow established connections to work. If knockd has not allowed new connections any traffic entering this chain will just return back and continue to match against the other rules until the end of the firewall. For example, to allow HTTPS requests based on a knock write: server https accept with knock hidden

then conﬁgure knockd to enable the HTTPS service with: iptables-A knock_hidden-s%IP%-j ACCEPT FireHOL + FireQOS Reference Release 2.0.0-pre7 59 / 215

and disable it with: iptables-D knock_hidden-s%IP%-j ACCEPT

You can use the same knock name in more than one FireHOL rule to enable/disable all the services based on a single knockd conﬁguration entry.

Note There is no need to match anything other than the IP in knockd. FireHOL already matches everything else needed for its rules to work. reject with message, reject reject discards the traffic matching the rules and sends a rejecting message back to the sender. When used with with the specific message to return can be specified. Run iptables -j REJECT --help for a list of the --reject-with values which can be used for message. See the section called “Reject With Messsages” for some examples. The default (no message specified) is to send tcp-reset when dealing with TCP connections and icmp-port-unreachable for all other protocols. For example: UNMATCHED_INPUT_POLICY="reject with host-prohib"

policy reject with host-unreach

server ident reject with tcp-reset drop, deny drop discards the trafﬁc matching the rules. It does so silently and the sender will need to timeout to conclude it cannot reach the service. deny is a synonym for drop. For example, either of these would silently discard SMTP trafﬁc: server smtp drop

server smtp deny return return will return the flow of processing to the parent of the current command. Currently, the only time return can be used meaningfully used is as a policy for an interface definition. Unmatched traffic will continue being processed with the possibility of being matched by a later definition. For example: policy return FireHOL + FireQOS Reference Release 2.0.0-pre7 60 / 215 tarpit tarpit captures and holds incoming TCP connections open. Connections are accepted and immediately switched to the persist state (0 byte window), in which the remote side stops sending data and asks to continue every 60-240 seconds. Attempts to close the connection are ignored, forcing the remote side to time out the connection after 12-24 minutes. Example: server smtp tarpit

Note As the kernel conntrack modules are always loaded by FireHOL, some per-connection resources will be consumed. See this bug report for details.

The following actions also exist but should not be used under normal circumstances: mirror mirror returns the traffic it receives by switching the source and destination fields. REJECT will be used for traffic generated by the local host.

Warning The MIRROR target was removed from the Linux kernel due to its security implications. MIRROR is dangerous; use it with care and only if you understand what you are doing. redirect, redirect to-port port redirect is used internally by FireHOL helper commands. Only FireHOL developers should need to use this action directly.

Reject With Messsages

The following RFCs contain information relevant to these messages: RFC 1812 RFC 1122 RFC 792 FireHOL + FireQOS Reference Release 2.0.0-pre7 61 / 215 icmp-net-unreachable, net-unreach ICMP network unreachable Generated by a router if a forwarding path (route) to the destination network is not available. From RFC 1812, section 5.2.7.1. See RFC 1812 and RFC 792.

Note Use with care. The sender and the routers between you and the sender may conclude that the whole network your host resides in is unreachable, and prevent other trafﬁc from reaching you. icmp-host-unreachable, host-unreach ICMP host unreachable Generated by a router if a forwarding path (route) to the destination host on a directly connected network is not available (does not respond to ARP). From RFC 1812, section 5.2.7.1. See RFC 1812 and RFC 792.

Note Use with care. The sender and the routers between you and the sender may conclude that your host is entirely unreachable, and prevent other traffic from reaching you. icmp-proto-unreachable, proto-unreach ICMP protocol unreachable Generated if the transport protocol designated in a datagram is not supported in the transport layer of the final destination. From RFC 1812, section 5.2.7.1. See RFC 1812 and RFC 792. icmp-port-unreachable, port-unreach ICMP port unreachable Generated if the designated transport protocol (e.g. TCP, UDP, etc.) is unable to demultiplex the datagram in the transport layer of the final destination but has no protocol mechanism to inform the sender. From RFC 1812, section 5.2.7.1. See RFC 1812 and RFC 792. Generated by hosts to indicate that the required port is not active. icmp-net-prohibited, net-prohib ICMP communication with destination network administratively prohibited This code was intended for use by end-to-end encryption devices used by U.S. military agencies. Routers SHOULD use the newly defined Code 13 (Communication Administratively Prohibited) if they administratively filter packets. From RFC 1812, section 5.2.7.1. See RFC 1812 and RFC 1122. FireHOL + FireQOS Reference Release 2.0.0-pre7 62 / 215

Note This message may not be widely understood. icmp-host-prohibited, host-prohib ICMP communication with destination host administratively prohibited This code was intended for use by end-to-end encryption devices used by U.S. military agencies. Routers SHOULD use the newly deﬁned Code 13 (Communication Administratively Prohibited) if they administratively ﬁlter packets. From RFC 1812, section 5.2.7.1. See RFC 1812 and RFC 1122.

Note This message may not be widely understood. tcp-reset TCP RST The port unreachable message of the TCP stack. See RFC 1122.

Note tcp-reset is useful when you want to prevent timeouts on rejected TCP services where the client incorrectly ignores ICMP port unreachable messages.

See Also

Chapter 10

Helper Commands FireHOL + FireQOS Reference Release 2.0.0-pre7 64 / 215

10.1 iptables helper: ﬁrehol-iptables

Name

ﬁrehol-iptables — include custom iptables commands

Synopsis iptables argument...

Description

The iptables helper command passes all of its arguments to the real iptables(8) at the appropriate point during run-time.

Note When used in an interface or router, the result will not have a direct relationship to the enclosing deﬁnition as the parameters passed are only those you supply.

You should not use /sbin/iptables directly in a FireHOL configuration as it will run before FireHOL activates its firewall. This means they it be applied to the running firewall, not the new firewall, so will be removed when the new firewall is activated. The iptables helper is provided to allow you to hook in commands safely.

See Also

FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) administration tool for IPv4 firewalls: iptables(8) FireHOL + FireQOS Reference Release 2.0.0-pre7 65 / 215

10.2 masquerade helper: ﬁrehol-masquerade

Name

ﬁrehol-masquerade — set up masquerading (NAT) on an interface

Synopsis masquerade real-interface [rule-params] masquerade [reverse] [rule-params]

Description

The masquerade helper command sets up masquerading on the output of a real network interface (as opposed to a FireHOL interface definition). If a real-interface is specified the command should be used before any interface or router definitions. Multiple values can be given separated by whitespace, so long as they are enclosed in quotes. If used within an interface definition the definition’s real-interface will be used. If used within a router definition the definition’s outface(s) will be used if specified. If the reverse option is gived, then the definition’s inface(s) will be used if specified. Unlike most commands, masquerade does not inherit its parent definition’s rules-params, it only honour’s its own. The inface and outface parameters should not be used (iptables does not support inface in the POSTROUTING chain and outface will be overwritten by FireHOL using the rules above).

Note The masquerade always applies to the output of the chosen network interfaces. FIREHOL_NAT will be turned on automatically (see control variables: ﬁrehol-variables(5)) and Fire- HOL will enable packet-forwarding in the kernel.

Masquerading and SNAT

Masquerading is a special form of Source NAT (SNAT) that changes the source of requests when they go out and replaces their original source when they come in. This way a Linux host can become an Internet router for a LAN of clients having unroutable IP addresses. Masquerading takes care to re-map IP addresses and ports as required. Masquerading is expensive compare to SNAT because it checks the IP address of the outgoing interface every time for every packet. If your host has a static IP address you should generally prefer SNAT. FireHOL + FireQOS Reference Release 2.0.0-pre7 66 / 215

Examples

# Before any interface or router masquerade eth0 src 192.0.2.0/24 dst not 192.0.2.0/24

# In an interface definition to masquerade the output of its real- ←- interface masquerade

# Ina router definition to masquerade the output of its outface masquerade

# Ina router definition to masquerade the output of its inface masquerade reverse

See Also

FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) interface definition: firehol-interface(5) router definition: firehol-router(5) optional rule parameters: firehol-rule-params(5) nat, snat, dnat, redirect config helpers: firehol-nat(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 67 / 215

10.3 tcpmss helper: ﬁrehol-tcpmss

Name

ﬁrehol-tcpmss — set the MSS of TCP SYN packets for routers

Synopsis tcpmss mss | auto [ if-list ]

Description

The tcpmss helper command sets the MSS (Maximum Segment Size) of TCP SYN packets routed through the firewall. This can be used to overcome situations where Path MTU Discovery is not working and packet fragmentation is not possible. A numeric mss will set MSS of TCP connections to the value given. Using the word auto will set the MSS to the MTU of the outgoing interface minus 40 (clamp-mss-to-pmtu). If used within a router or interface definition the MSS will be applied to outgoing traffic on the outf ace(s) of the router or interface. If used before any router or interface definitions it will be applied to all traffic passing through the firewall. If if-list is given, the MSS will be applied only to those interfaces.

Examples tcpmss auto tcpmss 500 tcpmss 500 "eth1 eth2 eth3"

See Also

FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) router definition: firehol-router(5) TCPMSS target in the iptables tutorial FireHOL + FireQOS Reference Release 2.0.0-pre7 68 / 215

Chapter 11

Conﬁguration Helper Commands FireHOL + FireQOS Reference Release 2.0.0-pre7 69 / 215

11.1 version conﬁg helper: ﬁrehol-version

Name

firehol-version — set version number of configuration file

Synopsis version 6

Description

The version helper command states the configuration file version. If the value passed is newer than the running version of FireHOL supports, FireHOL will not run. You do not have to specify a version number for a configuration file, but by doing so you will prevent FireHOL trying to process a file which it cannot handle. The value that FireHOL expects is increased every time that the configuration file format changes.

Note If you pass version 5 to FireHOL, it will disable IPv6 support and warn you that you must update your conﬁguration.

See Also

FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 70 / 215

11.2 action conﬁg helper: ﬁrehol-action

Name

ﬁrehol-action — set up custom ﬁlter actions

Synopsis action chain name action

Description

The action helper command creates an iptables chain which can be used to control the action of other firewall rules once the firewall is running. For example, you can setup the custom action ACT1, which by default is ACCEPT, but can be dynamically changed to DROP, REJECT or RETURN (and back) without restarting the firewall. The name can be any chain name accepted by iptables. You should try to keep it within 5 and 10 characters.

Note The names created with this command are case-sensitive.

The action can be any of those supported by FireHOL (see actions for rules: ﬁrehol-actions(5)). Only ACCEPT, REJECT, DROP, RETURN have any meaning in this instance.

Examples

To create a custom chain and have some rules use it: action chain ACT1 accept interface any world server smtp ACT1 client smtp ACT1

Once the ﬁrewall is running you can dynamically modify the behaviour of the chain from the Linux command-line, as detailed below: To insert a DROP action at the start of the chain to override the default action (ACCEPT): FireHOL + FireQOS Reference Release 2.0.0-pre7 71 / 215

iptables-t filter-I ACT1-j DROP

To delete the DROP action from the start of the chain to return to the default action: iptables-t filter-D ACT1-j DROP

Note If you delete all of the rules in the chain, the default will be to RETURN, in which case the behaviour will be as if any rules with the action were not present in the conﬁguration ﬁle.

You can also create multiple chains simultaneously. To create 3 ACCEPT and 3 DROP chains you can do the following: action chain"ACT1 ACT2 ACT3" accept action chain"ACT4 ACT5 ACT6" drop

See Also

FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) actions for rules: firehol-actions(5) administration tool for IPv4 firewalls: iptables(8) FireHOL + FireQOS Reference Release 2.0.0-pre7 72 / 215

11.3 blacklist conﬁg helper: ﬁrehol-blacklist

Name

ﬁrehol-blacklist — set up a unidirectional or bidirectional blacklist

Description

The blacklist helper command creates a blacklist for the ip list given (which can be in quotes or not). If the type full or one of its aliases is supplied, or no type is given, a bidirectional stateless blacklist will be generated. The firewall will REJECT all traffic going to the IP addresses and DROP all traffic coming from them. If the type input or one of its aliases is supplied, a unidirectional stateful blacklist will be generated. Connections can be initiated to such IP addresses, but the IP addresses will not be able to connect to the firewall or hosts protected by it. Any blacklists will affect all router and interface definitions. They must be declared before the first router or interface.

Examples blacklist full 192.0.2.1 192.0.2.2 blacklist input "192.0.2.3 192.0.2.4"

See Also

FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 73 / 215

11.4 classify conﬁg helper: ﬁrehol-classify

Name

firehol-classify — classify traffic for traffic shaping tools

Synopsis classify class [rule-params]

Description

The classify helper command puts matching traffic into the specified traffic shaping class. The class is a class as used by iptables and tc (e.g. MAJOR:MINOR). The rule-params define a set of rule parameters to match the traffic that is to be classified. See optional rule parameters: firehol-rule-params(5) for more details. Any classify commands will affect all traffic matched. They must be declared before the first router or interface.

Examples

# Put all smtp traffic leaving via eth1 in class 1:1 classify 1:1 outface eth1 proto tcp dport 25

See Also

FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) administration tool for IPv4 firewalls: iptables(8) show / manipulate traffic control settings: tc(8) Linux Advanced Routing & Traffic Control HOWTO FireHOL + FireQOS Reference Release 2.0.0-pre7 74 / 215

11.5 connmark conﬁg helper: ﬁrehol-connmark

Name

ﬁrehol-connmark — set a stateful mark on a connection

Synopsis connmark value | save | restore chain [rule-params]

Description

The connmark helper command sets a mark on a whole connection. It applies to both directions.

Note To set a mark on packets matching particular rules, regardless of any connection, see mark conﬁg helper: ﬁrehol-mark(5).

The value is the mark value to set (a 32 bit integer). If you specify save then the mark on the matched packet will be turned into a connmark. If you specify restore then the matched packet will have its mark set to the current connmark. The chain will be used to find traffic to mark. It can be any of the iptables built in chains belong- ing to the mangle table. The chain names are: INPUT, FORWARD, OUTPUT, PREROUTING and POSTROUTING. The names are case-sensitive. The rule-params define a set of rule parameters to match the traffic that is to be marked within the chosen chain. See optional rule parameters: firehol-rule-params(5) for more details. Any connmark commands will affect all traffic matched. They must be declared before the first router or interface.

Examples

Consider a scenario with 3 ethernet ports, where eth0 is on the local LAN, eth1 connects to ISP ’A’ and eth2 to ISP ’B’. To ensure trafﬁc leaves via the same ISP as it arrives from you can mark the trafﬁc: # mark connections when they arrive from the ISPs connmark1 PREROUTING inface eth1 connmark2 PREROUTING inface eth2 FireHOL + FireQOS Reference Release 2.0.0-pre7 75 / 215

# restore the mark(from the connmark) when packets arrive from the LAN connmark restore OUTPUT connmark restore PREROUTING inface eth0

It is then possible to use the commands from iproute2 such as ip, to pick the correct routing table based on the mark on the packets.

See Also

FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) mark config helper: firehol-mark(5) administration tool for IPv4 firewalls: iptables(8) show / manipulate routing, devices, policy routing and tunnels: ip(8) Linux Advanced Routing & Traffic Control HOWTO FireHOL + FireQOS Reference Release 2.0.0-pre7 76 / 215

11.6 dscp conﬁg helper: ﬁrehol-dscp

Name

ﬁrehol-dscp — set the DSCP ﬁeld in the packet header

Synopsis dscp value | class classid chain [rule-params]

Description

The dscp helper command sets the DSCP ﬁeld in the header of packets trafﬁc, to allow QoS shaping.

Note There is also a dscp parameter which allows matching DSCP values within individual rules (see optional rule parameters: ﬁrehol-rule-params(5)).

Set value to a decimal or hexadecimal (0xnn) number to set an explicit DSCP value or use class classid to use an iptables DiffServ class, such as EF, BE, CSxx or AFxx (see iptables -j DSCP --help for more information). The chain will be used to find traffic to mark. It can be any of the iptables built in chains belong- ing to the mangle table. The chain names are: INPUT, FORWARD, OUTPUT, PREROUTING and POSTROUTING. The names are case-sensitive. The rule-params define a set of rule parameters to match the traffic that is to be marked within the chosen chain. See optional rule parameters: firehol-rule-params(5) for more details. Any dscp commands will affect all traffic matched. They must be declared before the first router or interface.

Examples

# set DSCP field to 32, packets sent by the local machine dscp 32 OUTPUT

# set DSCP field to 32 (hex 20), packets routed by the local machine dscp0x20 FORWARD FireHOL + FireQOS Reference Release 2.0.0-pre7 77 / 215

# set DSCP to DiffServ classEF, packets routed by the local machine # and destined for port TCP/25 of 198.51.100.1 dscp classEF FORWARD proto tcp dport 25 dst 198.51.100.1

See Also

FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) administration tool for IPv4 firewalls: iptables(8) show / manipulate routing, devices, policy routing and tunnels: ip(8) Linux Advanced Routing & Traffic Control HOWTO optional rule parameters: firehol-rule-params(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 78 / 215

11.7 mac conﬁg helper: ﬁrehol-mac

Name

ﬁrehol-mac — ensure source IP and source MAC address match

Synopsis mac IP macaddr

Description

Any mac commands will affect all traffic destined for the firewall host, or to be forwarded by the host. They must be declared before the first router or interface.

Note There is also a mac parameter which allows matching MAC addresses within individual rules (see optional rule parameters: ﬁrehol-rule-params(5)).

The mac helper command DROPs traffic from any IP address that was not sent using the macaddr specified. When packets are dropped, a log is produced with the label "MAC MISSMATCH" (sic.). mac obeys the default log limits (see the section called “Logging” in optional rule parameters: firehol-rule-params(5)).

Note This command restricts an IP to a particular MAC address. The same MAC address is permitted send trafﬁc with a different IP.

Examples mac 192.0.2.1 00:01:01:00:00:e6 mac 198.51.100.1 00:01:01:02:aa:e8

See Also

FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) optional rule parameters: firehol-rule-params(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 79 / 215

11.8 mark conﬁg helper: ﬁrehol-mark

Name

firehol-mark — mark traffic for traffic shaping tools

Synopsis mark value chain [rule-params]

Description

The mark helper command sets a mark on packets that can be matched by trafﬁc shaping tools for controlling the trafﬁc.

Note To set a mark on whole connections, see connmark config helper: firehol-connmark(5). There is also a mark parameter which allows matching marks within individual rules (see optional rule parameters: firehol-rule-params(5)).

The value is the mark value to set (a 32 bit integer). The chain will be used to find traffic to mark. It can be any of the iptables built in chains belong- ing to the mangle table. The chain names are: INPUT, FORWARD, OUTPUT, PREROUTING and POSTROUTING. The names are case-sensitive. The rule-params define a set of rule parameters to match the traffic that is to be marked within the chosen chain. See optional rule parameters: firehol-rule-params(5) for more details. Any mark commands will affect all traffic matched. They must be declared before the first router or interface.

Note If you want to do policy based routing based on iptables marks, you will need to disable the Root Path Filtering on the interfaces involved (rp_ﬁlter in sysctl). FireHOL + FireQOS Reference Release 2.0.0-pre7 80 / 215

Examples

# mark with 1, packets sent by the local machine mark1 OUTPUT

# mark with 2, packets routed by the local machine mark2 FORWARD

# mark with 3, packets routed by the local machine, sent from # 192.0.2.2 destined for port TCP/25 of 198.51.100.1 mark3 FORWARD proto tcp dport 25 dst 198.51.100.1 src 192.0.2.2

See Also

FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) connmark config helper: firehol-connmark(5) administration tool for IPv4 firewalls: iptables(8) show / manipulate routing, devices, policy routing and tunnels: ip(8) Linux Advanced Routing & Traffic Control HOWTO optional rule parameters: firehol-rule-params(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 81 / 215

11.9 nat, snat, dnat, redirect conﬁg helpers: ﬁrehol-nat

Name

firehol-nat, firehol-snat, firehol-dnat, firehol-redirect — set up NAT and port redirections

Synopsis nat to-source | to-destination ipaddr[:port] [rule-params] nat redirect-to port[-range] [rule-params] snat [to] ipaddr[:port] [rule-params] dnat [to] ipaddr[:port] [rule-params] redirect [to] port[-range] [rule-params]

Description

Note The rule-params are used only to determine the traffic that will be matched for NAT in these commands, not to permit traffic to flow.

The dnat helper is a synonym for nat to-destination (Destination NAT), the snat helper is a synonym for nat to-source (Source NAT), and the redirect helper is a synonym for nat redirect-to (redirect to port on local host). The port part of the new address is optional with SNAT and DNAT; if not specified it will not be changed. When you apply NAT to a packet, the Linux kernel will track the changes it makes, so that when it sees replies the transformation will be applied in the opposite direction. For instance if you changed the destination port of a packet from 80 to 8080, when a reply comes back, its source is set as 80. This means the original sender does not need to be aware a transformation is happening. Applying NAT does not automatically create rules to allow the traffic to pass. You will still need to include client or server entries in an interface or router to allow the traffic. When using SNAT, the transformation is in the POSTROUTING chain of the NAT table and happens after normal rules are matched, so your client or server rule should match the "unmodified" traffic. When using DNAT or a REDIRECT, the transformation is in the PREROUTING chain of the NAT table and happens before normal rules are matched, so your client or server rule should match the "modified" traffic. FireHOL + FireQOS Reference Release 2.0.0-pre7 82 / 215

If you would like to see more detail, this flow diagram shows how network packets are processed by the kernel. The nat helper takes one of the following sub-commands: to-destination ipaddr[:port] Defines a Destination NAT (DNAT). Commonly thought of as port-forwarding (where packets destined for the firewall with a given port and protocol are sent to a different IP address and possibly port), DNAT is much more flexible in that any number of parameters can be matched before the destination information is rewritten. ipaddr[:port] is the destination address to be set in packets matching rule-params. If no rules are given, all forwarded traffic will be matched. outface should not be used in DNAT since the information is not available at the time the decision is made. ipaddr[:port] accepts any --to-destination values that iptables(8) accepts. Run iptables -j DNAT --help to for more information. Multiple ipaddr may be specified by separating with spaces and enclosing with quotes. to-source ipaddr[:port] Defines a Source NAT (SNAT). SNAT is similar to masquerading (see masquerade helper: firehol- masquerade(5)) but more efficient for static IP addresses. You can use it to give a public IP address to a host which does not have one behind the firewall. ipaddr[:port] is the source address to be set in packets matching rule-params. If no rules are given, all forwarded traffic will be matched. inface should not be used in SNAT since the information is not available at the time the decision is made. ipaddr[:port] accepts any --to-source values that iptables(8) accepts. Run iptables -j SNAT --help to for more information. Multiple ipaddr[:port] may be specified by separating with spaces and enclosing with quotes. redirect-to port[-range] Redirect matching traffic to the local machine. This is typically useful if you want to intercept some traffic and process it on the local machine. port[-range] is the port range (from-to) or single port that packets matching rule-params will be redirected to. If no rules are given, all forwarded traffic will be matched. outface should not be used in REDIRECT since the information is not available at the time the decision is made.

Examples

# Port forwarding HTTP dnat to 192.0.2.2 proto tcp dport 80 FireHOL + FireQOS Reference Release 2.0.0-pre7 83 / 215

# Port forwarding HTTPS on toa different port internally dnat to 192.0.2.2:4443 proto tcp dport 443

# Fix source for traffic leaving the firewall via eth0 with private ←- address snat to 198.51.100.1 outface eth0 src 192.168.0.0/24

# Transparent squid(running on the firewall) for some hosts redirect to 8080 inface eth0 src 198.51.100.0/24 proto tcp dport 80

# Send to 192.0.2.1 #- all traffic arriving at or passing through the firewall nat to-destination 192.0.2.1

# Send to 192.0.2.1 #- all traffic arriving at or passing through the firewall #- which WAS going to 203.0.113.1 nat to-destination 192.0.2.1 dst 203.0.113.1

# Send to 192.0.2.1 #- TCP traffic arriving at or passing through the firewall #- which WAS going to 203.0.113.1 nat to-destination 192.0.2.1 proto tcp dst 203.0.113.1

# Send to 192.0.2.1 #- TCP traffic arriving at or passing through the firewall #- which WAS going to 203.0.113.1, port 25 nat to-destination 192.0.2.1 proto tcp dport 25 dst 203.0.113.1

See Also

FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) interface definition: firehol-interface(5) router definition: firehol-router(5) optional rule parameters: firehol-rule-params(5) masquerade helper: firehol-masquerade(5) NAT HOWTO FireHOL + FireQOS Reference Release 2.0.0-pre7 84 / 215

11.10 transparent_proxy, transparent_squid helpers: ﬁrehol-transparent_proxy

Name

ﬁrehol-transparent_proxy, ﬁrehol-transparent_squid — set up a transparent proxy

Synopsis transparent_proxy service port user [rule-params] transparent_squid port user [rule-params]

Description

The transparent_proxy helper command sets up transparent caching for TCP trafﬁc.

Note The proxy application must be running on the ﬁrewall host at port port with the credentials of the local user user (which may be a space-delimited list enclosed in quotes) serving requests appropriate to the TCP port service.

The rule-params define a set of rule parameters to define the traffic that is to be proxied. See optional rule parameters: firehol-rule-params(5) for more details. For traffic destined for the firewall host or passing through the firewall, do not use the outface rule because the rules are applied before the routing decision and so the outgoing interface will not be known. An empty user string ("") disables caching of locally-generated traffic. Otherwise, traffic starting from the firewall is captured, except traffic generated by the local user(s) user. The inface, outface and src rule-params are all ignored for locally-generated traffic. The transparent_squid helper command sets up the special case for HTTP traffic with service implicitly set to 80.

Examples transparent_proxy 80 3128 squid inface eth0 src 192.0.2.0/24 transparent_squid 3128 squid inface eth0 src 192.0.2.0/24 transparent_proxy "80 3128 8080" 3128 "squid privoxy root bin"\ inface not"ppp+ ipsec+" dst not"a.not.proxied.server" transparent_squid "80 3128 8080" "squid privoxy root bin"\ inface not"ppp+ ipsec+" dst not"non.proxied.server" FireHOL + FireQOS Reference Release 2.0.0-pre7 85 / 215

See Also

11.11 tos conﬁg helper: ﬁrehol-tos

Name

ﬁrehol-tos — set the Type of Service (TOS) of packets

Synopsis tos value chain [rule-params]

Description

The tos helper command sets the Type of Service (TOS) ﬁeld in packet headers.

Note There is also a tos parameter which allows matching TOS values within individual rules (see optional rule parameters: ﬁrehol-rule-params(5)).

The value can be an integer number (decimal or hexadecimal) or one of the descriptive values accepted by iptables (run iptables -j TOS --help for a list). The chain will be used to find traffic to mark. It can be any of the iptables built in chains belong- ing to the mangle table. The chain names are: INPUT, FORWARD, OUTPUT, PREROUTING and POSTROUTING. The names are case-sensitive. The rule-params define a set of rule parameters to match the traffic that is to be marked within the chosen chain. See optional rule parameters: firehol-rule-params(5) for more details. Any tos commands will affect all traffic matched. They must be declared before the first router or interface.

Examples

# set TOS to 16, packets sent by the local machine tos 16 OUTPUT

# set TOS to0x10 (16), packets routed by the local machine tos0x10 FORWARD

# set TOS to Maximize-Throughput (8), packets routed by the local # machine, destined for port TCP/25 of 198.51.100.1 tos Maximize-Throughput FORWARD proto tcp dport 25 dst 198.51.100.1 FireHOL + FireQOS Reference Release 2.0.0-pre7 87 / 215

See Also

FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) tosfix config helper: firehol-tosfix(5) administration tool for IPv4 firewalls: iptables(8) optional rule parameters: firehol-rule-params(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 88 / 215

11.12 tosfix config helper: firehol-tosfix

Name

ﬁrehol-tosﬁx — apply suggested TOS values to packets

Synopsis tosfix

Description

The tosﬁx helper command sets the Type of Service (TOS) ﬁeld in packet headers based on the sugges- tions given by Erik Hensema in iptables and tc shaping tricks. The following TOS values are set:

• All TCP ACK packets with length less than 128 bytes are assigned Minimize-Delay, while bigger ones are assigned Maximize-Throughput • All packets with TOS Minimize-Delay, that are bigger than 512 bytes are set to Maximize-Throughput, except for short bursts of 2 packets per second

The tosﬁx command must be used before the ﬁrst router or interface.

See Also

FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) tos config helper: firehol-tos(5) administration tool for IPv4 firewalls: iptables(8) FireHOL + FireQOS Reference Release 2.0.0-pre7 89 / 215

Chapter 12

Services Reference FireHOL + FireQOS Reference Release 2.0.0-pre7 90 / 215

12.1 services list: ﬁrehol-services

Name

ﬁrehol-services — FireHOL service list

Services

This Wikipedia list of ports may be helpful if you need to deﬁne a new service. There are too many services for one page, so they are broken down alphabetically. The website has an easy-to-use single-page index.

See Also

services list a: firehol-services-a(5) services list b: firehol-services-b(5) services list c: firehol-services-c(5) services list d: firehol-services-d(5) services list e: firehol-services-e(5) services list f: firehol-services-f(5) services list g: firehol-services-g(5) services list h: firehol-services-h(5) services list i: firehol-services-i(5) services list j: firehol-services-j(5) services list k: firehol-services-k(5) services list l: firehol-services-l(5) services list m: firehol-services-m(5) services list n: firehol-services-n(5) services list o: firehol-services-o(5) services list p: firehol-services-p(5) services list q: firehol-services-q(5) services list r: firehol-services-r(5) services list s: firehol-services-s(5) services list t: firehol-services-t(5) services list u: firehol-services-u(5) services list v: firehol-services-v(5) services list w: firehol-services-w(5) services list x: firehol-services-x(5) services list y: firehol-services-y(5) services list z: firehol-services-z(5) FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 91 / 215

12.2 services list a: ﬁrehol-services-a

Name

ﬁrehol-services-a — FireHOL service list a

Services starting with A

AH - IPSec Authentication Header (AH) all - Match all traffic amanda - Advanced Maryland Automatic Network Disk Archiver any - Match all traffic (without modules or indirect) anystateless - Match all traffic statelessly apcupsd - APC UPS Daemon apcupsdnis - APC UPS Daemon Network Information Server aptproxy - Advanced Packaging Tool Proxy asterisk - Asterisk PABX

AH-IPSEC AUTHENTICATION HEADER (AH)

Example Conﬁguration sample: serverAH accept

Service Type simple Server Ports 51/any Client Ports any Links Wikipedia Notes For more information see this Archive of the FreeS/WAN documentation and RFC 2402.

ALL -MATCH ALL TRAFFIC

Example Conﬁguration sample: FireHOL + FireQOS Reference Release 2.0.0-pre7 92 / 215

server all accept

Service Type complex Server Ports all Client Ports all Notes Matches all trafﬁc (all protocols, ports, etc) while ensuring that required kernel modules are loaded. This service may indirectly setup a set of other services, if they require kernel modules to be loaded. The following complex services are activated: ftp - File Transfer Protocol irc - Internet Relay Chat

AMANDA -ADVANCED MARYLAND AUTOMATIC NETWORK DISK ARCHIVER

Service Type simple Server Ports udp/10080 Client Ports default Netﬁlter Modules nf_conntrack_amanda (CONFIG_NF_CONNTRACK_AMANDA) Netﬁlter NAT Modules nf_nat_amanda (CONFIG_NF_NAT_AMANDA) Links Homepage, Wikipedia

ANY -MATCH ALL TRAFFIC (WITHOUTMODULESORINDIRECT)

Example Conﬁguration sample: server any myname accept proto 47 FireHOL + FireQOS Reference Release 2.0.0-pre7 93 / 215

Service Type complex Server Ports all Client Ports all Notes Matches all traffic (all protocols, ports, etc), but does not care about kernel modules and does not activate any other service indirectly. In combination with the optional rule parameters: firehol-rule- params(5) this service can match unusual traffic (e.g. GRE - protocol 47). Note that you have to supply your own name in addition to "any".

ANYSTATELESS -MATCH ALL TRAFFIC STATELESSLY

Example Conﬁguration sample: server anystateless myname accept proto 47

Service Type complex Server Ports all Client Ports all Notes Matches all traffic (all protocols, ports, etc), but does not care about kernel modules and does not activate any other service indirectly. In combination with the optional rule parameters: firehol-rule- params(5) this service can match unusual traffic (e.g. GRE - protocol 47). This service is identical to "any" but does not care about the state of traffic. Note that you have to supply your own name in addition to "anystateless".

APCUPSD -APCUPSDAEMON

Example Conﬁguration sample: server apcupsd accept FireHOL + FireQOS Reference Release 2.0.0-pre7 94 / 215

Service Type simple Server Ports tcp/6544 Client Ports default Links Homepage, Wikipedia Notes This service must be defined as "server apcupsd accept" on all machines not directly connected to the UPS (i.e. slaves). Note that the port defined here is not the default port (6666) used if you download and compile APCUPSD, since the default conflicts with IRC and many distributions (like Debian) have changed this to 6544. You can define port 6544 in APCUPSD, by changing the value of NETPORT in its configuration file, or overwrite this FireHOL service definition using the procedures described in the section called “Adding Services” of FireHOL configuration: firehol.conf(5).

APCUPSDNIS -APCUPSDAEMON NETWORK INFORMATION SERVER

Example Conﬁguration sample: server apcupsdnis accept

Service Type simple Server Ports tcp/3551 Client Ports default Links Homepage, Wikipedia Notes This service allows the remote WEB interfaces of APCUPSD, to connect and get information from the server directly connected to the UPS device.

APTPROXY -ADVANCED PACKAGING TOOL PROXY FireHOL + FireQOS Reference Release 2.0.0-pre7 95 / 215

Example Conﬁguration sample: server aptproxy accept

Service Type simple Server Ports tcp/9999 Client Ports default Links Wikipedia

ASTERISK -ASTERISK PABX

Example Conﬁguration sample: server asterisk accept

Service Type simple Server Ports tcp/5038 Client Ports default Links Homepage, Wikipedia Notes This service refers only to the manager interface of asterisk. You should normally enable sip - Session Initiation Protocol, h323 - H.323 VoIP, rtp - Real-time Transport Protocol , etc. at the ﬁrewall level, if you enable the relative channel drivers of asterisk.

See Also

services list: firehol-services(5) FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 96 / 215

12.3 services list b: ﬁrehol-services-b

Name

ﬁrehol-services-b — FireHOL service list b

Services starting with B

Currently no services start with B

See Also

services list: firehol-services(5) FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 97 / 215

12.4 services list c: ﬁrehol-services-c

Name

ﬁrehol-services-c — FireHOL service list c

Services starting with C

cups - Common UNIX Printing System custom - Custom deﬁnitions cvspserver - Concurrent Versions System

CUPS -COMMON UNIXPRINTING SYSTEM

Example Conﬁguration sample: server cups accept

Service Type simple Server Ports tcp/631 udp/631 Client Ports any Links Homepage, Wikipedia

CUSTOM -CUSTOM DEFINITIONS

Example Conﬁguration sample: server custom myimap tcp/143 default accept

Service Type custom Server Ports N/A FireHOL + FireQOS Reference Release 2.0.0-pre7 98 / 215

Client Ports N/A Notes The full syntax is: subcommand custom name svr-proto/ports cli-ports action params This service is used by FireHOL to allow you create rules for services which do not have a definition. subcommand, action and params have their usual meanings. A name must be supplied along with server ports in the form proto/range and client ports which takes only a range. To define services with the built-in extension mechanism to avoid the need for custom services, see the section called “Adding Services” of FireHOL configuration: firehol.conf(5).

CVSPSERVER -CONCURRENT VERSIONS SYSTEM

Example Conﬁguration sample: server cvspserver accept

Service Type simple Server Ports tcp/2401 Client Ports default Links Homepage, Wikipedia

See Also

services list: firehol-services(5) FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 99 / 215

12.5 services list d: ﬁrehol-services-d

Name

ﬁrehol-services-d — FireHOL service list d

Services starting with D

darkstat - Darkstat network traffic analyser daytime - Daytime Protocol dcc - Distributed Checksum Clearinghouse dcpp - Direct Connect++ P2P dhcp - Dynamic Host Configuration Protocol dhcprelay - DHCP Relay dhcpv6 - Dynamic Host Configuration Protocol for IPv6 dict - Dictionary Server Protocol distcc - Distributed CC dns - Domain Name System

DARKSTAT -DARKSTAT NETWORK TRAFFIC ANALYSER

Example Conﬁguration sample: server darkstat accept

Service Type simple Server Ports tcp/666 Client Ports default Links Homepage

DAYTIME -DAYTIME PROTOCOL

Example Conﬁguration sample: server daytime accept FireHOL + FireQOS Reference Release 2.0.0-pre7 100 / 215

Service Type simple Server Ports tcp/13 Client Ports default Links Wikipedia

DCC -DISTRIBUTED CHECKSUM CLEARINGHOUSE

Example Conﬁguration sample: server dcc accept

Service Type simple Server Ports udp/6277 Client Ports default Links Wikipedia Notes See also this DCC FAQ.

DCPP -DIRECT CONNECT++ P2P

Example Conﬁguration sample: server dcpp accept

Service Type simple Server Ports tcp/1412 udp/1412 FireHOL + FireQOS Reference Release 2.0.0-pre7 101 / 215

Client Ports default Links Homepage

DHCP -DYNAMIC HOST CONFIGURATION PROTOCOL

Example Conﬁguration sample: server dhcp accept

Service Type complex Server Ports udp/67 Client Ports 68 Links Wikipedia Notes The dhcp service is implemented as stateless rules. DHCP clients broadcast to the network (src 0.0.0.0 dst 255.255.255.255) to find a DHCP server. If the DHCP service was stateful the iptables connection tracker would not match the packets and deny to send the reply. Note that this change does not affect the security of either DHCP servers or clients, since only the specific ports are allowed (there is no random port at either the server or the client side). Note also that the "server dhcp accept" or "client dhcp accept" commands should placed within interfaces that do not have src and / or dst defined (because of the initial broadcast). You can overcome this problem by placing the DHCP service on a separate interface, without a src or dst but with a policy return. Place this interface before the one that defines the rest of the services. For example: interface eth0 dhcp ~~~~policy return ~~~~server dhcp accept ~ interface eth0 lan src"$mylan" dst"$myip" ~~~~client all accept FireHOL + FireQOS Reference Release 2.0.0-pre7 102 / 215

This service implicitly sets its client or server to ipv4 mode.

DHCPRELAY -DHCPRELAY

Example Conﬁguration sample: server dhcprelay accept

Service Type simple Server Ports udp/67 Client Ports 67 Links Wikipedia Notes From RFC 1812 section 9.1.2: In many cases, BOOTP clients and their associated BOOTP server(s) do not reside on the same IP (sub)network. In such cases, a third-party agent is required to transfer BOOTP messages between clients and servers. Such an agent was originally referred to as a BOOTP forwarding agent. How- ever, to avoid confusion with the IP forwarding function of a router, the name BOOTP relay agent has been adopted instead. For more information about DHCP Relay see section 9.1.2 of RFC 1812 and section 4 of RFC 1542

DHCPV6 - DYNAMIC HOST CONFIGURATION PROTOCOLFOR IPV6

Example Conﬁguration sample: server dhcp accept src"fe80::/64" client dhcp accept src"fe80::/64"

Service Type complex Server Ports udp/547 Client Ports 546 FireHOL + FireQOS Reference Release 2.0.0-pre7 103 / 215

Links Wikipedia Notes The dhcp service is implemented as stateless rules. Clients broadcast from a link-local address to the multicast address ff02::1:2 to ﬁnd a server. The Server sends a unicast replies back to the client. If the DHCPv6 service was stateful, the iptables connection tracker would not match the packets and deny to the reply so the service is implemented as stateless rules. Note that this does not affect the security of either DHCP servers or clients, since only the speciﬁc ports are allowed (there is no random port at either the server or the client side). This service implicitly sets its client or server to ipv6 mode.

DICT -DICTIONARY SERVER PROTOCOL

Example Conﬁguration sample: server dict accept

Service Type simple Server Ports tcp/2628 Client Ports default Links Wikipedia Notes See RFC2229.

DISTCC -DISTRIBUTED CC

Example Conﬁguration sample: server distcc accept

Service Type simple FireHOL + FireQOS Reference Release 2.0.0-pre7 104 / 215

Server Ports tcp/3632 Client Ports default Links Homepage, Wikipedia Notes For distcc security, please check the distcc security design.

DNS -DOMAIN NAME SYSTEM

Example Conﬁguration sample: server dns accept

Service Type simple Server Ports udp/53 tcp/53 Client Ports any Links Wikipedia Notes On very busy DNS servers you may see a few dropped DNS packets in your logs. This is normal. The iptables connection tracker will timeout the session and lose unmatched DNS packets that arrive too late to be useful.

See Also

services list: firehol-services(5) FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 105 / 215

12.6 services list e: ﬁrehol-services-e

Name

ﬁrehol-services-e — FireHOL service list e

Services starting with E

echo - Echo Protocol emule - eMule (Donkey network client) eserver - eDonkey network server ESP - IPSec Encapsulated Security Payload (ESP)

ECHO -ECHO PROTOCOL

Example Conﬁguration sample: server echo accept

Service Type simple Server Ports tcp/7 Client Ports default Links Wikipedia

EMULE - EMULE (DONKEYNETWORKCLIENT)

Example Conﬁguration sample: client emule accept src 192.0.2.1

Service Type complex Server Ports many FireHOL + FireQOS Reference Release 2.0.0-pre7 106 / 215

Client Ports many Links Homepage Notes According to eMule Port Definitions, FireHOL defines: Accept from any client port to the server at tcp/4661 Accept from any client port to the server at tcp/4662 Accept from any client port to the server at udp/4665 Accept from any client port to the server at udp/4672 Accept from any server port to the client at tcp/4662 Accept from any server port to the client at udp/4672 Use the FireHOL client command: firehol-client(5) command to match the eMule client. Please note that the eMule client is an HTTP client also.

ESERVER - EDONKEY NETWORK SERVER

Example Conﬁguration sample: server eserver accept

Service Type simple Server Ports tcp/4661 udp/4661 udp/4665 Client Ports any Links Wikipedia

ESP-IPSEC ENCAPSULATED SECURITY PAYLOAD (ESP)

Example Conﬁguration sample: server ESP accept

Service Type simple FireHOL + FireQOS Reference Release 2.0.0-pre7 107 / 215

Server Ports 50/any Client Ports any Links Wikipedia Notes For more information see this Archive of the FreeS/WAN documentation RFC 2406.

See Also

services list: firehol-services(5) FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 108 / 215

12.7 services list f: ﬁrehol-services-f

Name

ﬁrehol-services-f — FireHOL service list f

Services starting with F

ﬁnger - Finger Protocol ftp - File Transfer Protocol FINGER -FINGER PROTOCOL

Example Conﬁguration sample: server finger accept

Service Type simple Server Ports tcp/79 Client Ports default Links Wikipedia

FTP -FILE TRANSFER PROTOCOL

Example Conﬁguration sample: server ftp accept

Service Type simple Server Ports tcp/21 Client Ports default FireHOL + FireQOS Reference Release 2.0.0-pre7 109 / 215

Netﬁlter Modules nf_conntrack_ftp (CONFIG_NF_CONNTRACK_FTP) Netﬁlter NAT Modules nf_nat_ftp (CONFIG_NF_NAT_FTP) Links Wikipedia Notes The FTP service matches both active and passive FTP connections.

See Also

services list: firehol-services(5) FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 110 / 215

12.8 services list g: ﬁrehol-services-g

Name

ﬁrehol-services-g — FireHOL service list g

Services starting with G

gift - giFT Internet File Transfer giftui - giFT Internet File Transfer User Interface gkrellmd - GKrellM Daemon GRE - Generic Routing Encapsulation

GIFT - GIFTINTERNET FILE TRANSFER

Example Conﬁguration sample: server gift accept

Service Type simple Server Ports tcp/4302 tcp/1214 tcp/2182 tcp/2472 Client Ports any Links Homepage, Wikipedia Notes The gift FireHOL service supports: Gnutella listening at tcp/4302 FastTrack listening at tcp/1214 OpenFT listening at tcp/2182 and tcp/2472 The above ports are the defaults given for the corresponding giFT modules. To allow access to the user interface ports of giFT, use the giftui - giFT Internet File Transfer User Interface.

GIFTUI - GIFTINTERNET FILE TRANSFER USER INTERFACE FireHOL + FireQOS Reference Release 2.0.0-pre7 111 / 215

Example Conﬁguration sample: server giftui accept

Service Type simple Server Ports tcp/1213 Client Ports default Links Homepage, Wikipedia Notes This service refers only to the user interface ports offered by giFT. To allow gift accept P2P requests, use the gift - giFT Internet File Transfer.

GKRELLMD -GKRELLMDAEMON

Example Conﬁguration sample: server gkrellmd accept

Service Type simple Server Ports tcp/19150 Client Ports default Links Homepage, Wikipedia

GRE-GENERIC ROUTING ENCAPSULATION

Example Conﬁguration sample: server GRE accept FireHOL + FireQOS Reference Release 2.0.0-pre7 112 / 215

Service Type simple Server Ports 47/any Client Ports any Netﬁlter Modules nf_conntrack_proto_gre (CONFIG_NF_CT_PROTO_GRE) Netﬁlter NAT Modules nf_nat_proto_gre (CONFIG_NF_NAT_PROTO_GRE) Links Wikipedia Notes Protocol No 47. For more information see RFC RFC 2784.

See Also

services list: firehol-services(5) FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 113 / 215

12.9 services list h: ﬁrehol-services-h

Name

ﬁrehol-services-h — FireHOL service list h

Services starting with H

h323 - H.323 VoIP heartbeat - HeartBeat http - Hypertext Transfer Protocol httpalt - HTTP alternate port https - Secure Hypertext Transfer Protocol hylafax - HylaFAX

H323 - H.323 VOIP

Example Conﬁguration sample: server h323 accept

Service Type simple Server Ports tcp/1720 Client Ports default Netﬁlter Modules nf_conntrack_h323 (CONFIG_NF_CONNTRACK_H323) Netﬁlter NAT Modules nf_nat_h323 (CONFIG_NF_NAT_H323) Links Wikipedia

HEARTBEAT -HEARTBEAT

Example Conﬁguration sample: FireHOL + FireQOS Reference Release 2.0.0-pre7 114 / 215

server heartbeat accept

Service Type simple Server Ports udp/690:699 Client Ports default Links Homepage Notes This FireHOL service has been designed such a way that it will allow multiple heartbeat clusters on the same LAN.

HTTP -HYPERTEXT TRANSFER PROTOCOL

Example Conﬁguration sample: server http accept

Service Type simple Server Ports tcp/80 Client Ports default Links Wikipedia

HTTPALT -HTTP ALTERNATE PORT

Example Conﬁguration sample: server httpalt accept FireHOL + FireQOS Reference Release 2.0.0-pre7 115 / 215

Service Type simple Server Ports tcp/8080 Client Ports default Links Wikipedia Notes This port is commonly used by web servers, web proxies and caches where the standard http - Hypertext Transfer Protocol port is not available or can or should not be used.

HTTPS -SECURE HYPERTEXT TRANSFER PROTOCOL

Example Conﬁguration sample: server https accept

Service Type simple Server Ports tcp/443 Client Ports default Links Wikipedia

HYLAFAX -HYLAFAX

Example Conﬁguration sample: server hylafax accept

Service Type complex Server Ports many FireHOL + FireQOS Reference Release 2.0.0-pre7 116 / 215

Client Ports many Links Homepage, Wikipedia Notes This service allows incoming requests to server port tcp/4559 and outgoing from server port tcp/4558. The correct operation of this service has not been veriﬁed. USE THIS WITH CARE. A HYLAFAX CLIENT MAY OPEN ALL TCP UNPRIVILEGED PORTS TO ANYONE (from port tcp/4558).

See Also

services list: firehol-services(5) FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 117 / 215

12.10 services list i: ﬁrehol-services-i

Name

ﬁrehol-services-i — FireHOL service list i

Services starting with I

iax - Inter-Asterisk eXchange iax2 - Inter-Asterisk eXchange v2 icmp - Internet Control Message Protocol ICMP - Internet Control Message Protocol ICMPV6 - Internet Control Message Protocol v6 icmpv6 - Internet Control Message Protocol v6 icp - Internet Cache Protocol ident - Identiﬁcation Protocol imap - Internet Message Access Protocol imaps - Secure Internet Message Access Protocol ipsecnatt - NAT traversal and IPsec ipv6error - ICMPv6 Error Handling ipv6neigh - IPv6 Neighbour discovery ipv6router - IPv6 Router discovery irc - Internet Relay Chat isakmp - Internet Security Association and Key Management Protocol (IKE)

IAX -INTER-ASTERISKEXCHANGE

Example Conﬁguration sample: server iax accept

Service Type simple Server Ports udp/5036 Client Ports default Links Homepage, Wikipedia FireHOL + FireQOS Reference Release 2.0.0-pre7 118 / 215

Notes This service refers to IAX version 1. There is also iax2 - Inter-Asterisk eXchange v2.

IAX2 - INTER-ASTERISKEXCHANGEV2

Example Conﬁguration sample: server iax2 accept

Service Type simple Server Ports udp/5469 udp/4569 Client Ports default Links Homepage, Wikipedia Notes This service refers to IAX version 2. There is also iax - Inter-Asterisk eXchange.

ICMP -INTERNET CONTROL MESSAGE PROTOCOL

Alias See ICMP - Internet Control Message Protocol

ICMP-INTERNET CONTROL MESSAGE PROTOCOL

Example Conﬁguration sample: server ICMP accept

Service Type simple Server Ports icmp/any Client Ports any FireHOL + FireQOS Reference Release 2.0.0-pre7 119 / 215

Links Wikipedia

ICMPV6 - INTERNET CONTROL MESSAGE PROTOCOLV6

Example Conﬁguration sample: server ICMPV6 accept

Service Type simple Server Ports icmpv6/any Client Ports any Links Wikipedia

ICMPV6 - INTERNET CONTROL MESSAGE PROTOCOLV6

Alias See ICMPV6 - Internet Control Message Protocol v6

ICP -INTERNET CACHE PROTOCOL

Example Conﬁguration sample: server icp accept

Service Type simple Server Ports udp/3130 Client Ports 3130 Links Wikipedia FireHOL + FireQOS Reference Release 2.0.0-pre7 120 / 215

IDENT -IDENTIFICATION PROTOCOL

Example Conﬁguration sample: server ident reject with tcp-reset

Service Type simple Server Ports tcp/113 Client Ports default Links Wikipedia

IMAP -INTERNET MESSAGE ACCESS PROTOCOL

Example Conﬁguration sample: server imap accept

Service Type simple Server Ports tcp/143 Client Ports default Links Wikipedia

IMAPS -SECURE INTERNET MESSAGE ACCESS PROTOCOL

Example Conﬁguration sample: server imaps accept FireHOL + FireQOS Reference Release 2.0.0-pre7 121 / 215

Service Type simple Server Ports tcp/993 Client Ports default Links Wikipedia

IPSECNATT - NAT TRAVERSAL AND IPSEC

Service Type simple Server Ports udp/4500 Client Ports any Links Wikipedia

IPV6ERROR -ICMPV6 ERROR HANDLING

Example Conﬁguration sample: server ipv6error accept

Service Type complex Server Ports N/A Client Ports N/A Notes Not all icmpv6 error types should be treated equally inbound and outbound. The ipv6error rule wraps all of them in the following way: FireHOL + FireQOS Reference Release 2.0.0-pre7 122 / 215

allow incoming messages only for existing sessions allow outgoing messages always The following ICMPv6 messages are handled: destination-unreachable packet-too-big ttl-zero-during-transit ttl-zero-during-reassembly unknown-header-type unknown-option Interfaces should always have this set: server ipv6error accept

In a router with inface being internal and outface being external the following will meet the recommendations of RFC 4890: server ipv6error accept

Do not use: client ipv6error accept

unless you are controlling trafﬁc on a router interface where outface is the internal destination. This service implicitly sets its client or server to ipv6 mode.

IPV6NEIGH -IPV6 NEIGHBOUR DISCOVERY

Example Conﬁguration sample: client ipv6neigh accept server ipv6neigh accept

Service Type complex Server Ports N/A Client Ports N/A Links Wikipedia FireHOL + FireQOS Reference Release 2.0.0-pre7 123 / 215

Notes IPv6 uses the Neighbour Discovery Protocol to do automatic conﬁguration of routes and to replace ARP. To allow this functionality the network neighbour and router solicitation/advertisement messages should be enabled on each interface. These rules are stateless since advertisement can happen automatically as well as on solicitation. Neighbour discovery (incoming) should always be enabled: server ipv6neigh accept

Neighbour advertisement (outgoing) should always be enabled: client ipv6neigh accept

The rules should not be used to pass packets across a firewall (e.g. in a router definition) unless the firewall is for a bridge. This service implicitly sets its client or server to ipv6 mode.

IPV6ROUTER -IPV6 ROUTER DISCOVERY

Example Conﬁguration sample: client ipv6router accept

Service Type complex Server Ports N/A Client Ports N/A Links Wikipedia Notes IPv6 uses the Neighbour Discovery Protocol to do automatic conﬁguration of routes and to replace ARP. To allow this functionality the network neighbour and router solicitation/advertisement messages should be enabled on each interface. These rules are stateless since advertisement can happen automatically as well as on solicitation. Router discovery (incoming) should always be enabled: client ipv6router accept FireHOL + FireQOS Reference Release 2.0.0-pre7 124 / 215

Router advertisement (outgoing) should be enabled on a host that routes: server ipv6router accept

The rules should not be used to pass packets across a firewall (e.g. in a router definition) unless the firewall is for a bridge. This service implicitly sets its client or server to ipv6 mode.

IRC -INTERNET RELAY CHAT

Example Conﬁguration sample: server irc accept

Service Type simple Server Ports tcp/6667 Client Ports default Netﬁlter Modules nf_conntrack_irc (CONFIG_NF_CONNTRACK_IRC) Netﬁlter NAT Modules nf_nat_irc (CONFIG_NF_NAT_IRC) Links Wikipedia

ISAKMP -INTERNET SECURITY ASSOCIATION AND KEY MANAGEMENT PROTOCOL (IKE)

Example Conﬁguration sample: server isakmp accept

Service Type simple Server Ports udp/500 FireHOL + FireQOS Reference Release 2.0.0-pre7 125 / 215

Client Ports any Links Wikipedia Notes For more information see the Archive of the FreeS/WAN documentation

See Also

services list: firehol-services(5) FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 126 / 215

12.11 services list j: ﬁrehol-services-j

Name

ﬁrehol-services-j — FireHOL service list j

Services starting with J

jabber - Extensible Messaging and Presence Protocol jabberd - Extensible Messaging and Presence Protocol (Server) JABBER -EXTENSIBLE MESSAGINGAND PRESENCE PROTOCOL

Example Conﬁguration sample: server jabber accept

Service Type simple Server Ports tcp/5222 tcp/5223 Client Ports default Links Wikipedia Notes Allows clear and SSL client-to-server connections.

JABBERD -EXTENSIBLE MESSAGINGAND PRESENCE PROTOCOL (SERVER)

Example Conﬁguration sample: server jabberd accept

Service Type simple Server Ports tcp/5222 tcp/5223 tcp/5269 FireHOL + FireQOS Reference Release 2.0.0-pre7 127 / 215

Client Ports default Links Wikipedia Notes Allows clear and SSL client-to-server and server-to-server connections. Use this service for a jabberd server. In all other cases, use the jabber - Extensible Messaging and Presence Protocol.

See Also

services list: firehol-services(5) FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 128 / 215

12.12 services list k: ﬁrehol-services-k

Name

ﬁrehol-services-k — FireHOL service list k

Services starting with K

Currently no services start with K

See Also

services list: firehol-services(5) FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 129 / 215

12.13 services list l: ﬁrehol-services-l

Name

ﬁrehol-services-l — FireHOL service list l

Services starting with L

l2tp - Layer 2 Tunneling Protocol ldap - Lightweight Directory Access Protocol ldaps - Secure Lightweight Directory Access Protocol lpd - Line Printer Daemon Protocol L2TP -LAYER 2 TUNNELING PROTOCOL

Service Type simple Server Ports udp/1701 Client Ports any Links Wikipedia

LDAP -LIGHTWEIGHT DIRECTORY ACCESS PROTOCOL

Example Conﬁguration sample: server ldap accept

Service Type simple Server Ports tcp/389 Client Ports default Links Wikipedia FireHOL + FireQOS Reference Release 2.0.0-pre7 130 / 215

LDAPS -SECURE LIGHTWEIGHT DIRECTORY ACCESS PROTOCOL

Example Conﬁguration sample: server ldaps accept

Service Type simple Server Ports tcp/636 Client Ports default Links Wikipedia

LPD -LINE PRINTER DAEMON PROTOCOL

Example Conﬁguration sample: server lpd accept

Service Type simple Server Ports tcp/515 Client Ports any Links Wikipedia Notes LPD is documented in RFC 1179. Since many operating systems incorrectly use the non-default client ports for LPD access, this deﬁnition allows any client port to access the service (in addition to the RFC deﬁned 721 to 731 inclusive). FireHOL + FireQOS Reference Release 2.0.0-pre7 131 / 215

See Also

services list: firehol-services(5) FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 132 / 215

12.14 services list m: ﬁrehol-services-m

Name

ﬁrehol-services-m — FireHOL service list m

Services starting with M

microsoft_ds - Direct Hosted (NETBIOS-less) SMB mms - Microsoft Media Server msn - Microsoft MSN Messenger Service msnp - msnp ms_ds - Direct Hosted (NETBIOS-less) SMB multicast - Multicast mysql - MySQL

MICROSOFT_DS -DIRECT HOSTED (NETBIOS-LESS)SMB

Example Conﬁguration sample: server microsoft_ds accept

Service Type simple Server Ports tcp/445 Client Ports default Notes Direct Hosted (i.e. NETBIOS-less SMB) This is another NETBIOS Session Service with minor differences with netbios_ssn - NETBIOS Session Service . It is supported only by Windows 2000 and Windows XP and it offers the advan- tage of being independent of WINS for name resolution. It seems that samba supports transparently this protocol on the netbios_ssn - NETBIOS Session Service ports, so that either direct hosted or traditional SMB can be served simultaneously. Please refer to the netbios_ssn - NETBIOS Session Service for more information.

MMS -MICROSOFT MEDIA SERVER FireHOL + FireQOS Reference Release 2.0.0-pre7 133 / 215

Example Conﬁguration sample: server mms accept

Service Type simple Server Ports tcp/1755 udp/1755 Client Ports default Netﬁlter Modules See here. Netﬁlter NAT Modules See here. Links Wikipedia Notes Microsoft’s proprietary network streaming protocol used to transfer unicast data in Windows Media Services (previously called NetShow Services).

MSN -MICROSOFT MSNMESSENGER SERVICE

Example Conﬁguration sample: server msn accept

Service Type simple Server Ports tcp/1863 udp/1863 Client Ports default

MSNP - MSNP

Example Conﬁguration sample: FireHOL + FireQOS Reference Release 2.0.0-pre7 134 / 215

server msnp accept

Service Type simple Server Ports tcp/6891 Client Ports default

MS_DS -DIRECT HOSTED (NETBIOS-LESS)SMB

Alias See microsoft_ds - Direct Hosted (NETBIOS-less) SMB

MULTICAST -MULTICAST

Example Conﬁguration sample: server multicast reject with proto-unreach

Service Type complex Server Ports N/A Client Ports N/A Links Wikipedia Notes The multicast service matches all packets sent to the $MULTICAST_IPS addresses using IGMP or UDP. For IPv4 that means 224.0.0.0/4 and for IPv6 FF00::/16.

MYSQL -MYSQL

Example Conﬁguration sample: FireHOL + FireQOS Reference Release 2.0.0-pre7 135 / 215

server mysql accept

Service Type simple Server Ports tcp/3306 Client Ports default Links Homepage, Wikipedia

See Also

services list: firehol-services(5) FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 136 / 215

12.15 services list n: ﬁrehol-services-n

Name

ﬁrehol-services-n — FireHOL service list n

Services starting with N

netbackup - Veritas NetBackup service netbios_dgm - NETBIOS Datagram Distribution Service netbios_ns - NETBIOS Name Service netbios_ssn - NETBIOS Session Service nfs - Network File System nis - Network Information Service nntp - Network News Transfer Protocol nntps - Secure Network News Transfer Protocol nrpe - Nagios NRPE ntp - Network Time Protocol nut - Network UPS Tools nxserver - NoMachine NX Server

NETBACKUP -VERITAS NETBACKUP SERVICE

Example Conﬁguration sample: server netbackup accept client netbackup accept

Service Type simple Server Ports tcp/13701 tcp/13711 tcp/13720 tcp/13721 tcp/13724 tcp/13782 tcp/13783 Client Ports any Links Wikipedia Notes To use this service you must deﬁne it as both client and server in NetBackup clients and NetBackup servers. FireHOL + FireQOS Reference Release 2.0.0-pre7 137 / 215

NETBIOS_DGM -NETBIOSDATAGRAM DISTRIBUTION SERVICE

Example Conﬁguration sample: server netbios_dgm accept

Service Type simple Server Ports udp/138 Client Ports any Links Wikipedia Notes See also the samba - Samba. Keep in mind that this service broadcasts (to the broadcast address of your LAN) UDP packets. If you place this service within an interface that has a dst parameter, remember to include (in the dst parameter) the broadcast address of your LAN too.

NETBIOS_NS -NETBIOSNAME SERVICE

Example Conﬁguration sample: server netbios_ns accept

Service Type simple Server Ports udp/137 Client Ports any Links Wikipedia Notes See also the samba - Samba. FireHOL + FireQOS Reference Release 2.0.0-pre7 138 / 215

NETBIOS_SSN -NETBIOSSESSION SERVICE

Example Conﬁguration sample: server netbios_ssn accept

Service Type simple Server Ports tcp/139 Client Ports default Links Wikipedia Notes See also the samba - Samba. Please keep in mind that newer NETBIOS clients prefer to use port 445 (microsoft_ds - Direct Hosted (NETBIOS-less) SMB ) for the NETBIOS session service, and when this is not available they fall back to port 139 (netbios_ssn). Versions of samba above 3.x bind automatically to ports 139 and 445. If you have an older samba version and your policy on an interface or router is DROP, clients trying to access port 445 will have to timeout before falling back to port 139. This timeout can be up to several minutes. To overcome this problem you can explicitly REJECT the microsoft_ds - Direct Hosted (NETBIOS- less) SMB with a tcp-reset message: server microsoft_ds reject with tcp-reset

NFS -NETWORK FILE SYSTEM

Example Conﬁguration sample: client nfs accept dst 192.0.2.1

Service Type complex Server Ports many FireHOL + FireQOS Reference Release 2.0.0-pre7 139 / 215

Client Ports N/A Links Wikipedia Notes The NFS service queries the RPC service on the NFS server host to find out the ports nfsd, mountd, lockd and rquotad are listening. Then, according to these ports it sets up rules on all the supported protocols (as reported by RPC) in order the clients to be able to reach the server. For this reason, the NFS service requires that: the firewall is restarted if the NFS server is restarted the NFS server must be specified on all nfs statements (only if it is not the localhost) Since NFS queries the remote RPC server, it is required to also be allowed to do so, by allowing the portmap - Open Network Computing Remote Procedure Call - Port Mapper too. Take care that this is allowed by the running firewall when FireHOL tries to query the RPC server. So you might have to setup NFS in two steps: First add the portmap service and activate the firewall, then add the NFS service and restart the firewall. To avoid this you can setup your NFS server to listen on pre-defined ports, as documented in NFS Howto. If you do this then you will have to define the the ports using the procedure described in the section called “Adding Services” of FireHOL configuration: firehol.conf(5).

NIS -NETWORK INFORMATION SERVICE

Example Conﬁguration sample: client nis accept dst 192.0.2.1

Service Type complex Server Ports many Client Ports N/A Links Wikipedia Notes The nis service queries the RPC service on the nis server host to ﬁnd out the ports ypserv and yp- passwdd are listening. Then, according to these ports it sets up rules on all the supported protocols (as reported by RPC) in order the clients to be able to reach the server. FireHOL + FireQOS Reference Release 2.0.0-pre7 140 / 215

For this reason, the nis service requires that: the firewall is restarted if the nis server is restarted the nis server must be specified on all nis statements (only if it is not the localhost) Since nis queries the remote RPC server, it is required to also be allowed to do so, by allowing the portmap - Open Network Computing Remote Procedure Call - Port Mapper too. Take care that this is allowed by the running firewall when FireHOL tries to query the RPC server. So you might have to setup nis in two steps: First add the portmap service and activate the firewall, then add the nis service and restart the firewall. This service was added to FireHOL by Carlos Rodrigues. His comments regarding this implementation, are: These rules work for client access only! Pushing changes to slave servers won’t work if these rules are active somewhere between the master and its slaves, because it is impossible to predict the ports where yppush will be listening on each push. Pulling changes directly on the slaves will work, and could be improved performance-wise if these rules are modified to open fypxfrd. This wasn’t done because it doesn’t make that much sense since pushing changes on the master server is the most common, and recommended, way to replicate maps.

NNTP -NETWORK NEWS TRANSFER PROTOCOL

Example Conﬁguration sample: server nntp accept

Service Type simple Server Ports tcp/119 Client Ports default Links Wikipedia

NNTPS -SECURE NETWORK NEWS TRANSFER PROTOCOL

Example Conﬁguration sample: FireHOL + FireQOS Reference Release 2.0.0-pre7 141 / 215

server nntps accept

Service Type simple Server Ports tcp/563 Client Ports default Links Wikipedia

NRPE -NAGIOS NRPE

Service Type simple Server Ports tcp/5666 Client Ports default Links Wikipedia

NTP -NETWORK TIME PROTOCOL

Example Conﬁguration sample: server ntp accept

Service Type simple Server Ports udp/123 tcp/123 Client Ports any Links Wikipedia FireHOL + FireQOS Reference Release 2.0.0-pre7 142 / 215

NUT -NETWORK UPSTOOLS

Example Conﬁguration sample: server nut accept

Service Type simple Server Ports tcp/3493 udp/3493 Client Ports default Links Homepage

NXSERVER -NOMACHINE NXSERVER

Example Conﬁguration sample: server nxserver accept

Service Type simple Server Ports tcp/5000:5200 Client Ports default Links Wikipedia Notes Default ports used by NX server for connections without encryption. Note that nxserver also needs the ssh - Secure Shell Protocol to be enabled. This information has been extracted from this The TCP ports used by nxserver are 4000 + DIS- PLAY_BASE to 4000 + DISPLAY_BASE + DISPLAY_LIMIT. DISPLAY_BASE and DISPLAY_LIMIT are set in /usr/NX/etc/node.conf and the defaults are DISPLAY_BASE=1000 and DISPLAY_LIMIT=200. For encrypted nxserver sessions, only ssh - Secure Shell Protocol is needed. FireHOL + FireQOS Reference Release 2.0.0-pre7 143 / 215

See Also

services list: firehol-services(5) FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 144 / 215

12.16 services list o: ﬁrehol-services-o

Name

ﬁrehol-services-o — FireHOL service list o

Services starting with O

openvpn - OpenVPN oracle - Oracle Database OSPF - Open Shortest Path First

OPENVPN -OPENVPN

Service Type simple Server Ports tcp/1194 udp/1194 Client Ports default Links Homepage, Wikipedia

ORACLE -ORACLE DATABASE

Example Conﬁguration sample: server oracle accept

Service Type simple Server Ports tcp/1521 Client Ports default Links Wikipedia FireHOL + FireQOS Reference Release 2.0.0-pre7 145 / 215

OSPF-OPEN SHORTEST PATH FIRST

Example Conﬁguration sample: server OSPF accept

Service Type simple Server Ports 89/any Client Ports any Links Wikipedia

See Also

services list: firehol-services(5) FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 146 / 215

12.17 services list p: ﬁrehol-services-p

Name

ﬁrehol-services-p — FireHOL service list p

Services starting with P

ping - Ping (ICMP echo) pop3 - Post Ofﬁce Protocol pop3s - Secure Post Ofﬁce Protocol portmap - Open Network Computing Remote Procedure Call - Port Mapper postgres - PostgreSQL pptp - Point-to-Point Tunneling Protocol privoxy - Privacy Proxy PING -PING (ICMP ECHO)

Example Conﬁguration sample: server ping accept

Service Type complex Server Ports N/A Client Ports N/A Links Wikipedia Notes This services matches requests of protocol ICMP and type echo-request (TYPE=8) and their replies of type echo-reply (TYPE=0). The ping service is stateful.

POP3 - POST OFFICE PROTOCOL

Example Conﬁguration sample: FireHOL + FireQOS Reference Release 2.0.0-pre7 147 / 215

server pop3 accept

Service Type simple Server Ports tcp/110 Client Ports default Links Wikipedia

POP3S -SECURE POST OFFICE PROTOCOL

Example Conﬁguration sample: server pop3s accept

Service Type simple Server Ports tcp/995 Client Ports default Links Wikipedia

PORTMAP -OPEN NETWORK COMPUTING REMOTE PROCEDURE CALL -PORT MAPPER

Example Conﬁguration sample: server portmap accept

Service Type simple Server Ports udp/111 tcp/111 FireHOL + FireQOS Reference Release 2.0.0-pre7 148 / 215

Client Ports any Links Wikipedia

POSTGRES -POSTGRESQL

Example Conﬁguration sample: server postgres accept

Service Type simple Server Ports tcp/5432 Client Ports default Links Wikipedia

PPTP -POINT-TO-POINT TUNNELING PROTOCOL

Example Conﬁguration sample: server pptp accept

Service Type simple Server Ports tcp/1723 Client Ports default Netﬁlter Modules nf_conntrack_pptp (CONFIG_NF_CONNTRACK_PPTP), nf_conntrack_proto_gre (CONFIG_NF_CT_PROTO_GRE) Netﬁlter NAT Modules nf_nat_pptp (CONFIG_NF_NAT_PPTP), nf_nat_proto_gre (CONFIG_NF_NAT_PROTO_GRE) FireHOL + FireQOS Reference Release 2.0.0-pre7 149 / 215

Links Wikipedia

PRIVOXY -PRIVACY PROXY

Example Conﬁguration sample: server privoxy accept

Service Type simple Server Ports tcp/8118 Client Ports default Links Homepage

See Also

services list: firehol-services(5) FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 150 / 215

12.18 services list q: ﬁrehol-services-q

Name

ﬁrehol-services-q — FireHOL service list q

Services starting with Q

Currently no services start with Q

See Also

services list: firehol-services(5) FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 151 / 215

12.19 services list r: ﬁrehol-services-r

Name

ﬁrehol-services-r — FireHOL service list r

Services starting with R

radius - Remote Authentication Dial In User Service (RADIUS) radiusold - Remote Authentication Dial In User Service (RADIUS) radiusoldproxy - Remote Authentication Dial In User Service (RADIUS) radiusproxy - Remote Authentication Dial In User Service (RADIUS) rdp - Remote Desktop Protocol rndc - Remote Name Daemon Control rsync - rsync protocol rtp - Real-time Transport Protocol

RADIUS -REMOTE AUTHENTICATION DIAL IN USER SERVICE (RADIUS)

Example Conﬁguration sample: server radius accept

Service Type simple Server Ports udp/1812 udp/1813 Client Ports default Links Wikipedia

RADIUSOLD -REMOTE AUTHENTICATION DIAL IN USER SERVICE (RADIUS)

Example Conﬁguration sample: server radiusold accept FireHOL + FireQOS Reference Release 2.0.0-pre7 152 / 215

Service Type simple Server Ports udp/1645 udp/1646 Client Ports default Links Wikipedia

RADIUSOLDPROXY -REMOTE AUTHENTICATION DIAL IN USER SERVICE (RADIUS)

Example Conﬁguration sample: server radiusoldproxy accept

Service Type simple Server Ports udp/1647 Client Ports default Links Wikipedia

RADIUSPROXY -REMOTE AUTHENTICATION DIAL IN USER SERVICE (RADIUS)

Example Conﬁguration sample: server radiusproxy accept

Service Type simple Server Ports udp/1814 Client Ports default FireHOL + FireQOS Reference Release 2.0.0-pre7 153 / 215

Links Wikipedia

RDP -REMOTE DESKTOP PROTOCOL

Example Conﬁguration sample: server rdp accept

Service Type simple Server Ports tcp/3389 Client Ports default Links Wikipedia Notes Remote Desktop Protocol is also known also as Terminal Services.

RNDC -REMOTE NAME DAEMON CONTROL

Example Conﬁguration sample: server rndc accept

Service Type simple Server Ports tcp/953 Client Ports default Links Wikipedia

RSYNC - RSYNCPROTOCOL FireHOL + FireQOS Reference Release 2.0.0-pre7 154 / 215

Example Conﬁguration sample: server rsync accept

Service Type simple Server Ports tcp/873 udp/873 Client Ports default Links Homepage, Wikipedia

RTP -REAL-TIME TRANSPORT PROTOCOL

Example Conﬁguration sample: server rtp accept

Service Type simple Server Ports udp/10000:20000 Client Ports any Links Wikipedia Notes RTP ports are generally all the UDP ports. This deﬁnition narrows down RTP ports to UDP 10000 to 20000.

See Also

services list: firehol-services(5) FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 155 / 215

12.20 services list s: ﬁrehol-services-s

Name

ﬁrehol-services-s — FireHOL service list s

Services starting with S

samba - Samba sane - SANE Scanner service sip - Session Initiation Protocol smtp - Simple Mail Transport Protocol smtps - Secure Simple Mail Transport Protocol snmp - Simple Network Management Protocol snmptrap - SNMP Trap socks - SOCKet Secure squid - Squid Web Cache ssh - Secure Shell Protocol stun - Session Traversal Utilities for NAT submission - SMTP over SSL/TLS submission sunrpc - Open Network Computing Remote Procedure Call - Port Mapper swat - Samba Web Administration Tool syslog - Syslog Remote Logging Protocol

SAMBA -SAMBA

Example Conﬁguration sample: server samba accept

Service Type complex Server Ports many Client Ports default Links Homepage, Wikipedia FireHOL + FireQOS Reference Release 2.0.0-pre7 156 / 215

Notes The samba service automatically sets all the rules for netbios_ns - NETBIOS Name Service, net- bios_dgm - NETBIOS Datagram Distribution Service, netbios_ssn - NETBIOS Session Service and microsoft_ds - Direct Hosted (NETBIOS-less) SMB. Please refer to the notes of the above services for more information. NETBIOS initiates based on the broadcast address of an interface (request goes to broadcast address) but the server responds from its own IP address. This makes the "server samba accept" statement drop the server reply, because of the way the iptables connection tracker works. This service deﬁnition includes a hack, that allows a Linux samba server to respond correctly in such situations, by allowing new outgoing connections from the well known netbios_ns - NETBIOS Name Service port to the clients high ports. However, for clients and routers this hack is not applied because it would open all unprivileged ports to the samba server. The only solution to overcome the problem in such cases (routers or clients) is to build a trust relationship between the samba servers and clients.

SANE -SANESCANNER SERVICE

Service Type simple Server Ports tcp/6566 Client Ports default Netﬁlter Modules nf_conntrack_sane (CONFIG_NF_CONNTRACK_SANE) Netﬁlter NAT Modules N/A Links Homepage

SIP -SESSION INITIATION PROTOCOL

Example Conﬁguration sample: server sip accept

Service Type simple FireHOL + FireQOS Reference Release 2.0.0-pre7 157 / 215

Server Ports udp/5060 Client Ports 5060 default Netﬁlter Modules nf_conntrack_sip (CONFIG_NF_CONNTRACK_SIP) Netﬁlter NAT Modules nf_nat_sip (CONFIG_NF_NAT_SIP) Links Wikipedia Notes SIP is an IETF standard protocol (RFC 2543) for initiating interactive user sessions involving multimedia elements such as video, voice, chat, gaming, etc. SIP works in the application layer of the OSI communications model.

SMTP -SIMPLE MAIL TRANSPORT PROTOCOL

Example Conﬁguration sample: server smtp accept

Service Type simple Server Ports tcp/25 Client Ports default Links Wikipedia

SMTPS -SECURE SIMPLE MAIL TRANSPORT PROTOCOL

Example Conﬁguration sample: server smtps accept FireHOL + FireQOS Reference Release 2.0.0-pre7 158 / 215

Service Type simple Server Ports tcp/465 Client Ports default Links Wikipedia

SNMP -SIMPLE NETWORK MANAGEMENT PROTOCOL

Example Conﬁguration sample: server snmp accept

Service Type simple Server Ports udp/161 Client Ports default Links Wikipedia

SNMPTRAP -SNMPTRAP

Example Conﬁguration sample: server snmptrap accept

Service Type simple Server Ports udp/162 Client Ports any FireHOL + FireQOS Reference Release 2.0.0-pre7 159 / 215

Links Wikipedia Notes An SNMP trap is a notiﬁcation from an agent to a manager.

SOCKS -SOCKET SECURE

Example Conﬁguration sample: server socks accept

Service Type simple Server Ports tcp/1080 udp/1080 Client Ports default Links Wikipedia Notes See also RFC 1928.

SQUID -SQUID WEB CACHE

Example Conﬁguration sample: server squid accept

Service Type simple Server Ports tcp/3128 Client Ports default Links Homepage, Wikipedia FireHOL + FireQOS Reference Release 2.0.0-pre7 160 / 215

SSH -SECURE SHELL PROTOCOL

Example Conﬁguration sample: server ssh accept

Service Type simple Server Ports tcp/22 Client Ports default Links Wikipedia

STUN -SESSION TRAVERSAL UTILITIESFOR NAT

Example Conﬁguration sample: server stun accept

Service Type simple Server Ports udp/3478 udp/3479 Client Ports any Links Wikipedia Notes STUN is a protocol for assisting devices behind a NAT ﬁrewall or router with their packet routing.

SUBMISSION -SMTP OVER SSL/TLS SUBMISSION

Example Conﬁguration sample: FireHOL + FireQOS Reference Release 2.0.0-pre7 161 / 215

server submission accept

Service Type simple Server Ports tcp/587 Client Ports default Links Wikipedia Notes Submission is essentially normal SMTP with an SSL/TLS negotiation.

SUNRPC -OPEN NETWORK COMPUTING REMOTE PROCEDURE CALL -PORT MAPPER

Alias See portmap - Open Network Computing Remote Procedure Call - Port Mapper

SWAT -SAMBA WEB ADMINISTRATION TOOL

Example Conﬁguration sample: server swat accept

Service Type simple Server Ports tcp/901 Client Ports default Links Homepage

SYSLOG -SYSLOG REMOTE LOGGING PROTOCOL

Example Conﬁguration sample: FireHOL + FireQOS Reference Release 2.0.0-pre7 162 / 215

server syslog accept

Service Type simple Server Ports udp/514 Client Ports syslog default Links Wikipedia

See Also

services list: firehol-services(5) FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 163 / 215

12.21 services list t: ﬁrehol-services-t

Name

ﬁrehol-services-t — FireHOL service list t

Services starting with T

telnet - Telnet tftp - Trivial File Transfer Protocol time - Time Protocol timestamp - ICMP Timestamp tomcat - HTTP alternate port

TELNET -TELNET

Example Conﬁguration sample: server telnet accept

Service Type simple Server Ports tcp/23 Client Ports default Links Wikipedia

TFTP -TRIVIAL FILE TRANSFER PROTOCOL

Example Conﬁguration sample: server tftp accept

Service Type simple FireHOL + FireQOS Reference Release 2.0.0-pre7 164 / 215

Server Ports udp/69 Client Ports default Netﬁlter Modules nf_conntrack_tftp (CONFIG_NF_CONNTRACK_TFTP) Netﬁlter NAT Modules nf_nat_tftp (CONFIG_NF_NAT_TFTP) Links Wikipedia

TIME -TIME PROTOCOL

Example Conﬁguration sample: server time accept

Service Type simple Server Ports tcp/37 udp/37 Client Ports default Links Wikipedia

TIMESTAMP -ICMPTIMESTAMP

Example Conﬁguration sample: server timestamp accept

Service Type complex Server Ports N/A FireHOL + FireQOS Reference Release 2.0.0-pre7 165 / 215

Client Ports N/A Links Wikipedia Notes This services matches requests of protocol ICMP and type timestamp-request (TYPE=13) and their replies of type timestamp-reply (TYPE=14). The timestamp service is stateful.

TOMCAT -HTTP ALTERNATE PORT

Alias See httpalt - HTTP alternate port

See Also

services list: firehol-services(5) FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 166 / 215

12.22 services list u: ﬁrehol-services-u

Name

ﬁrehol-services-u — FireHOL service list u

Services starting with U

upnp - Universal Plug and Play uucp - Unix-to-Unix Copy UPNP -UNIVERSAL PLUGAND PLAY

Example Conﬁguration sample: server upnp accept

Service Type simple Server Ports udp/1900 tcp/2869 Client Ports default Links Homepage, Wikipedia Notes For a Linux implementation see: Linux IGD.

UUCP -UNIX-TO-UNIX COPY

Example Conﬁguration sample: server uucp accept

Service Type simple Server Ports tcp/540 FireHOL + FireQOS Reference Release 2.0.0-pre7 167 / 215

Client Ports default Links Wikipedia

See Also

services list: firehol-services(5) FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 168 / 215

12.23 services list v: ﬁrehol-services-v

Name

ﬁrehol-services-v — FireHOL service list v

Services starting with V

vmware - vmware vmwareauth - vmwareauth vmwareweb - vmwareweb vnc - Virtual Network Computing VMWARE - VMWARE

Example Conﬁguration sample: server vmware accept

Service Type simple Server Ports tcp/902 Client Ports default Notes Used from VMWare 1 and up. See the VMWare KnowledgeBase.

VMWAREAUTH - VMWAREAUTH

Example Conﬁguration sample: server vmwareauth accept

Service Type simple Server Ports tcp/903 FireHOL + FireQOS Reference Release 2.0.0-pre7 169 / 215

Client Ports default Notes Used from VMWare 1 and up. See the VMWare KnowledgeBase.

VMWAREWEB - VMWAREWEB

Example Conﬁguration sample: server vmwareweb accept

Service Type simple Server Ports tcp/8222 tcp/8333 Client Ports default Notes Used from VMWare 2 and up. See VMWare Server 2.0 release notes and the VMWare Knowl- edgeBase.

VNC -VIRTUAL NETWORK COMPUTING

Example Conﬁguration sample: server vnc accept

Service Type simple Server Ports tcp/5900:5903 Client Ports default Links Wikipedia Notes VNC is a graphical desktop sharing protocol. FireHOL + FireQOS Reference Release 2.0.0-pre7 170 / 215

See Also

services list: firehol-services(5) FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 171 / 215

12.24 services list w: ﬁrehol-services-w

Name

ﬁrehol-services-w — FireHOL service list w

Services starting with W

webcache - HTTP alternate port webmin - Webmin Administration System whois - WHOIS Protocol

WEBCACHE -HTTP ALTERNATE PORT

Alias See httpalt - HTTP alternate port

WEBMIN -WEBMIN ADMINISTRATION SYSTEM

Example Conﬁguration sample: server webmin accept

Service Type simple Server Ports tcp/10000 Client Ports default Links Homepage

WHOIS -WHOISPROTOCOL

Example Conﬁguration sample: server whois accept FireHOL + FireQOS Reference Release 2.0.0-pre7 172 / 215

Service Type simple Server Ports tcp/43 Client Ports default Links Wikipedia

See Also

services list: firehol-services(5) FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 173 / 215

12.25 services list x: ﬁrehol-services-x

Name

ﬁrehol-services-x — FireHOL service list x

Services starting with X

xbox - Xbox Live xdmcp - X Display Manager Control Protocol

XBOX -XBOX LIVE

Example Conﬁguration sample: client xbox accept

Service Type complex Server Ports many Client Ports default Notes Deﬁnition for the Xbox live service. See program source for contributor details.

XDMCP -XDISPLAY MANAGER CONTROL PROTOCOL

Example Conﬁguration sample: server xdmcp accept

Service Type simple Server Ports udp/177 FireHOL + FireQOS Reference Release 2.0.0-pre7 174 / 215

Client Ports default Links Wikipedia Notes See Gnome Display Manager for a discussion about XDMCP and ﬁrewalls (Gnome Display Man- ager is a replacement for XDM).

See Also

services list: firehol-services(5) FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 175 / 215

12.26 services list y: ﬁrehol-services-y

Name

ﬁrehol-services-y — FireHOL service list y

Services starting with Y

Currently no services start with Y

See Also

services list: firehol-services(5) FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 176 / 215

12.27 services list z: ﬁrehol-services-z

Name

ﬁrehol-services-z — FireHOL service list z

Services starting with Z

Currently no services start with Z

See Also

services list: firehol-services(5) FireHOL program: firehol(1) FireHOL configuration: firehol.conf(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 177 / 215

Part IV

FireQOS Reference FireHOL + FireQOS Reference Release 2.0.0-pre7 178 / 215

Chapter 13

Running and Conﬁguring FireHOL + FireQOS Reference Release 2.0.0-pre7 179 / 215

13.1 FireQOS program: ﬁreqos

Name

ﬁreqos — an easy to use but powerful trafﬁc shaping tool

Description

FireQOS is a helper to assist you configure traffic shaping on Linux. Run without any arguments, fireqos will present some help on usage. When given CONFIGFILE, fireqos will use the named file instead of /etc/firehol/fireqos. conf as its configuration. The parameter name always refers to and interface name from the configuration file. The parameter class always refers to a named class within a named interface. It is possible to pass arguments for use by the configuration file separating any conf-arg values from the rest of the arguments with --. The arguments are accessible in the configuration using standard bash(1) syntax e.g. $1, $2, etc.

Commands start, debug Activates traffic shaping on all interfaces, as given in the configuration file. When invoked as debug, FireQOS also prints all of the tc(8) commands it executes. stop Removes all traffic shaping applied by FireQOS (it does not touch QoS on other interfaces and IFBs used by other tools). FireHOL + FireQOS Reference Release 2.0.0-pre7 180 / 215 clear_all_qos Removes all traffic shaping on all network interfaces and removes all IFB devices from the system, even those applied by other tools. status Shows live utilisation for the specified interface. FireQOS will show you the rate of traffic on all classes, adding one line per second (similarly to vmstat, iostat, etc.) If dump is specified, it tcpdumps the traffic in the given class of the interface. tcpdump, dump FireQOS temporarily mirrors the traffic of any leaf class to an IFB device. Then it runs tcpdump on this interface to dump the traffic to your console. You may add any tcpdump parameters you like to the command line, (to dump the traffic to a file, match a subset of the traffic, etc.), for example this: fireqos tcpdump adsl-in voip-n

will start a tcpdump of all trafﬁc on interface adsl-in, in class voip. The parameter -n is a tcpdump parameter.

Note When FireQOS is running in tcpdump mode, it locks itself and will refuse to run in parallel with another FireQOS altering the QoS, or tcpdumping other traffic. This is because FireQOS reserves device ifb0 for monitoring. If two FireQOS processes were allowed to tcpdump in parallel, your dumps would be wrong. So it locks itself to prevent such a case. drops Shows packets dropped per second, per class, for the specified interface. overlimits Shows packets delayed per second, per class, for the specified interface. requeues Shows packets requeued per second, per class, for the specified interface.

Files

/etc/firehol/fireqos.conf

See Also

FireQOS configuration: fireqos.conf(5) FireHOL Manual: firehol-manual.pdf FireHOL Online Documentation FireHOL + FireQOS Reference Release 2.0.0-pre7 181 / 215

13.2 FireQOS conﬁguration: ﬁreqos.conf

Name

fireqos.conf — FireQOS configuration file

Description

This file defines the traffic shaping that will be applied by FireQOS program: fireqos(1). The default configuration file is /etc/firehol/fireqos.conf. It can be overridden from the command line. A configuration consists of a number of input and output interface definitions (see interface definition: fireqos-interface(5)). Each interface can define any number of (optionally nested) classes (see traffic class: fireqos-class(5)) which shape the traffic which they match (see traffic match: fireqos-match(5)).

Speed Units

In FireQOS, speeds can be expressed in the following units:

#bps # bytes per second

#kbps, #Kbps # kilobytes per second

#mbps, #Mbps # megabytes per second

#gbps, #Gbps # gigabytes per second

#bit # bits per second

#kbit, #Kbit, # # kilobits per second (default)

#mbit, #Mbit # megabits per second

#gbit, #Gbit # gigabits per second FireHOL + FireQOS Reference Release 2.0.0-pre7 182 / 215

#% In a class, uses this percentage of the enclosing rate.

Note The default, kbit is different to tc which assumes bytes per second when no unit is speciﬁed.

Example

# incoming traffic from my ADSL router interface eth2 adsl-in input rate 10500kbit adsl remote pppoe-llc class voip commit 100kbit pfifo match udp ports 5060,10000:10100 # asterisk sip and rtp match udp ports 16393:16402 # apple facetime

class realtime commit 10% match tcp port 22,1195:1198,1753 # ssh, openvpn, pptp match udp port 53 # dns match proto GRE match icmp match tcp syn match tcp ack

class clients commit 10% match tcp port 20,21,25,80,143,443,465,873,993 # mail, web, ftp, etc

# unmatched traffic goes here(’default’ isa special name) class default max 90%

#I define torrents beneath the default class, becauseI want them # to slow down when the default class is willing to get bandwidth class torrents max 90% match port 51414 # my torrent client

# outgoing traffic to my ADSL router interface eth2 adsl-out output rate 800kbit adsl remote pppoe-llc class voip commit 100kbit pfifo match udp ports 5060,10000:10100 # asterisk sip and rtp match udp ports 16393:16402 # apple facetime

class realtime commit 10% match tcp port 22,1195:1198,1753 # ssh, openvpn, pptp match udp port 53 # dns match proto GRE match icmp match tcp syn FireHOL + FireQOS Reference Release 2.0.0-pre7 183 / 215

match tcp ack

class clients commit 10% match tcp port 20,21,25,80,143,443,465,873,993 # mail, web, ftp, etc

# unmatched traffic goes here(’default’ isa special name) class default max 90%

#I define torrents, beneath the default class, becauseI want them # to slow down when the default class is willing to get bandwidth class torrents max 90% match port 51414 # my torrent client

See Also

FireQOS program: fireqos(1) interface definition: fireqos-interface(5) FireHOL Manual: firehol-manual.pdf FireHOL Online Documentation FireHOL + FireQOS Reference Release 2.0.0-pre7 184 / 215

Chapter 14

Organising Trafﬁc FireHOL + FireQOS Reference Release 2.0.0-pre7 185 / 215

14.1 interface deﬁnition: ﬁreqos-interface

Name

fireqos-interface, fireqos-interface4, fireqos-interface6, fireqos-interface46 — create an interface definition

Synopsis interface|interface4 device name direction [optional-class-params] rate | commit | min speed interface46 ... interface6 ...

Description

Writing interface or interface4 applies traffic shaping rules only to IPv4 traffic. Writing interface6 applies traffic shaping rules only to IPv6 traffic. Writing interface46 applies traffic shaping rules to both IPv4 and IPv6 traffic. The actual traffic shaping behaviour of a class is defined by adding classes. See traffic class: fireqos- class(5).

Note To achieve best results with incoming trafﬁc shaping, you should not use 100% of the available bandwidth at the interface level. If you use all there is, at 100% utilisation of the link, the neighbour routers will start queuing packets. This will destroy prioritisation. Try 85% or 90% instead.

Parameters device This is the interface name as shown by ip link show (e.g. eth0, ppp1, etc.) name This is a single-word name for this interface and is used for retrieving status information later. FireHOL + FireQOS Reference Release 2.0.0-pre7 186 / 215

direction If set to input, traffic coming in to the interface is shaped. If set to output, traffic going out via the interface is shaped. optional-class-params For a list of optional class parameters which can be applied to an interface, see optional class parameters: fireqos-class-params(5). speed For an interface, the committed speed must be specified with the rate option. The speed can be expressed in any of the units described in FireQOS configuration: fireqos.conf(5).

Examples

To create an input policy on eth0, capable of delivering up to 1Gbit of trafﬁc: interface eth0 lan-in input rate1Gbit

See Also

FireQOS program: fireqos(1) FireQOS configuration: fireqos.conf(5) optional class parameters: fireqos-class-params(5) traffic class: fireqos-class(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 187 / 215

14.2 trafﬁc class: ﬁreqos-class

Name

fireqos-class, fireqos-class4, fireqos-class6, fireqos-class46 — define a traffic class

Description

There is also an optional match parameter called class; see optional match parameters: fireqos-match- params(5). Writing class inherits the IPv4/IPv6 version from its enclosing interface (see interface definition: fireqos- interface(5)). Writing class4 includes only IPv4 traffic in the class. Writing class6 includes only IPv6 traffic in the class. Writing class46 includes both IPv4 and IPv6 traffic in the class. The actual traffic to be matched by a class is defined by adding matches. See traffic match: fireqos- match(5). The sequence that classes appear in the configuration defines their priority. The first class is the most important one. Unless otherwise limited it will get all available bandwidth if it needs to. The second class is less important than the first, the third is even less important than the second, etc. The idea is very simple: just put the classes in the order of importance to you. Classes can have their priority assigned explicitly with the prio parameter. See optional class parameters: fireqos-class-params(5).

Note The underlying Linux qdisc used by FireQOS, HTB, supports only 8 priorities, from 0 to 7. If you use more than 8 priorities, all after the 8th will get the same priority (prio 7). FireHOL + FireQOS Reference Release 2.0.0-pre7 188 / 215

All classes in FireQOS share the interface bandwidth. However, every class has a committed rate (the minimum guaranteed speed it will get if it needs to) and a ceiling (the maximum rate this class can reach, provided there is capacity available and even if there is spare). Classes may be nested to any level by using the class group syntax. By default FireQOS creates nested classes as classes directly attached to their parent class. This way, nesting does not add any delays. FireQOS can also emulate new hardware at the group class level. This may be needed, when for example you have an ADSL router that you connect to via Ethernet: you want the LAN traffic to be at Ethernet speed, but WAN traffic at ADSL speed with proper ADSL overheads calculation. To accomplish hardware emulation nesting, you add a linklayer definition (ethernet, adsl, atm, etc.) or just an mtu to the group class. FireQOS will create a qdisc within the class, where the linklayer parameters will be assigned and the child classes will be attached to this qdisc. This adds some delay to the packets of the child classes, but allows you to emulate new hardware. For linklayer options, see optional class parameters: fireqos-class-params(5). There is special class, called default. Default classes can be given explicitly in the configuration file. If they are not found in the config, FireQOS will append one at the end of each interface or class group.

Parameters group It is possible to nest classes by using a group. Grouped classes must be closed with the class group end command. name This is a single-word name for this class and is used for displaying status information. optional-class-params The set of optional class parameters to apply to this class. The following optional class parameters are inherited from the interface the class is in: ceil burst cburst quantum qdisc If you deﬁne one of these at the interface level, then all classes within the interface will get the value by default. These values can be overwritten by deﬁning the parameter on the class too. Optional class parameters not in the above list are not inherited from interfaces. FireHOL + FireQOS Reference Release 2.0.0-pre7 189 / 215

Examples

To create a nested class, called servers, containing http and smtp: interface eth0 lan input rate1Gbit class voip commit1Mbit match udp ports 5060,10000:10100

class group servers commit 50% # define the parent class match tcp# apply to all child classes

class mail commit 50% # 50% of parent(’servers’) match port 25 # matches within parent(’servers’)

class web commit 50% match port 80 class group end# end the group’servers’

class streaming commit 30%

To create a nested class which emulates an ADSL modem: interface eth0 lan output rate1Gbit ethernet class lan match dst 192.168.0.0/24 # LAN traffic

class group adsl rate 10Mbit ceil 10Mbit adsl remote pppoe-llc match all# all non-lan traffic in this emulated hardware group

class voip# class within adsl match udp port 5060

class web# class within adsl match tcp port 80,443 class group end

See Also

FireQOS program: fireqos(1) FireQOS configuration: fireqos.conf(5) optional class parameters: fireqos-class-params(5) interface definition: fireqos-interface(5) traffic match: fireqos-match(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 190 / 215

14.3 trafﬁc match: ﬁreqos-match

Name

fireqos-match, fireqos-match4, fireqos-match6, fireqos-match46 — define a traffic match

Synopsis match|match4|match6|match46 [optional-match-params]

Description

Writing match inherits the IPv4/IPv6 version from its enclosing class (see traffic class: fireqos-class(5)). Writing match4 includes only IPv4 traffic in the match. Writing match6 includes only IPv6 traffic in the match. Writing match46 includes both IPv4 and IPv6 traffic in the match. You can add as many match statements as you like to a FireQOS configuration. They assign traffic to a class (see traffic class: fireqos-class(5)), by default to the class after which they are declared. The sequence that matches appear in the configuration defines their priority, with the first match being given a prio of 10, with 10 added for each subsequent match (10, 20, 30, ...). Matches can have their priority assigned explicitly with the prio parameter. See optional match parameters: fireqos-match-params(5). If one match statement generates multiple tc filter statements, all filters generated by the same match statement will have the same prio.

Note match rules are attached to the parent of the class they appear in. Within the conﬁguration they are written under a class, but in reality they are attached to their class parent, so that they classify the parent’s trafﬁc that they match, into the class.

It is also possible to group all match statements together below the classes. This allows them to be arranged in preferred order, without the need for any explicit prio parameters. In this case however, each match statement must specify to which class it classiﬁes the packets it matches, using the class parameter. See optional match parameters: ﬁreqos-match-params(5) and the examples below. FireHOL + FireQOS Reference Release 2.0.0-pre7 191 / 215

Parameters optional-match-params The set of optional parameters which describe this match. See optional match parameters: ﬁreqos- match-params(5).

Examples

Match trafﬁc within classes: interface eth0 lan output rate1Gbit class voip match udp ports 5060,10000:10100 class dns match udp port 53 class mail match tcp port 25

Matches split out and explicitly assigning traffic to classes (N.B. without the class parameters, all traffic would be classified into ’mail’): interface eth0 lan output rate1Gbit class voip class dns class mail

match udp ports 5060,10000:10100 class voip match tcp port 25 class mail match tcp port 80 class web

See Also

FireQOS program: fireqos(1) FireQOS configuration: fireqos.conf(5) optional match parameters: fireqos-match-params(5) interface definition: fireqos-interface(5) traffic class: fireqos-class(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 192 / 215

Chapter 15

Optional Parameters FireHOL + FireQOS Reference Release 2.0.0-pre7 193 / 215

15.1 class/match parameters: ﬁreqos-shared-params

Name

ﬁreqos-prio, ﬁreqos-priority — class/match parameters

Description

Some optional parameter names are the same for both class and match. This page exists as a placeholder to help you find the appropriate documentation. For the class version, see optional class parameters: fireqos-class-params(5). For the match version, see optional match parameters: fireqos-match-params(5).

See Also

FireQOS program: fireqos(1) FireQOS configuration: fireqos.conf(5) traffic class: fireqos-class(5) traffic match: fireqos-match(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 194 / 215

15.2 optional class parameters: ﬁreqos-class-params

Name

fireqos-class-params, fireqos-rate, fireqos-commit, fireqos-min, fireqos-ceil, fireqos-max, fireqos-minrate, fireqos-qdisc, fireqos-pfifo, fireqos-bfifo, fireqos-sfq, fireqos-fq_codel, fireqos-codel, fireqos-none, fireqos- class-prio, fireqos-linklayer, fireqos-ethernet, fireqos-atm, fireqos-adsl, fireqos-mtu, fireqos-mpu, fireqos- tsize, fireqos-overhead, fireqos-r2q, fireqos-burst, fireqos-cburst, fireqos-quantum, fireqos-class-priority, fireqos-balanced — optional class parameters

Description

All of the options apply to interface and class statements. Units for speeds are defined in FireQOS configuration: fireqos.conf(5). FireHOL + FireQOS Reference Release 2.0.0-pre7 195 / 215 rate speed, commit speed, min speed When a committed rate is provided to a class, it means that the bandwidth will be given to the class when it needs it. If the class does not need the bandwidth, it will be available for any other class to use. For interfaces, a rate must be defined. For classes the rate defaults to 1/100 of the interface capacity. ceil speed, max speed Defines the maximum speed a class can use. Even there is available bandwidth, a class will not exceed its ceil speed. For interfaces, the default is the rate speed of the interface. For classes, the defaults is the ceil of the their interfaces. minrate speed Defines the default committed speed for all classes not specifically given a rate in the config file. It forces a recalculation of tc r2q. When minrate is not given, FireQOS assigns a default value of 1/100 of the interface rate. qdisc qdisc-name, pfifo, bfifo, sfq, fq_codel, codel, none The qdisc defines the method to distribute class bandwidth to its sockets. It is applied within the class itself and is useful in cases where a class gets saturated. For information about these, see http://www.tldp.org/HOWTO/Traffic-Control-HOWTO/classless-qdiscs.html A qdisc is only useful when applied to a class. It can be specified at the interface level in order to set the default for all of the included classes. To pass options to a qdisc, you can specify them through an environment variable or explicitly on each class. Set the variable FIREQOS_DEFAULT_QDISC_OPTIONS_qdiscname in the config file. For example, for sfq: FIREQOS_DEFAULT_QDISC_OPTIONS_sfq="perturb 10 quantum 2000".

Using this variable each sfq will get these options by default. You can still override this by specifying explicit options for individual qdiscs. Add options "qdisc options here". So to specify, for example, sfq options you would write: class name sfq options"perturb 10 quantum 2000"

The options keyword must appear just after the qdisc name. prio 0..7|keep|last HTB supports 8 priorities, from 0 to 7. Any number less than 0 will give priority 0. Any number above 7 will give priority 7. By default, FireQOS gives the first class priority 0, and increases this number by 1 for each class it encounters in the config file. If there are more than 8 classes, all classes after the 8th will get priority 7. In balanced mode (see prioritybalanced), all classes will get priority 4 by default. FireHOL + FireQOS Reference Release 2.0.0-pre7 196 / 215

FireQOS restarts priorities for each interface and class group. The class priority deﬁnes how the spare bandwidth is spread among the classes. Classes with higher priorities (lower prio) will get all spare bandwidth. Classes with the same priority will get a percentage of the spare bandwidth, proportional to their committed rates. The keywords keep and last will make a class use the priority of the class just above / before it. So to make two consecutive classes have the same prio, just add prio keep to the second one. linklayer linklayer-name, ethernet, atm The linklayer can only be given on interfaces. It is used by the kernel to calculate the overheads in the packets. adsl local|remote encapsulation adsl is a special linklayer that automatically calculates ATM overheads for the link. local is used when the ADSL modem is directly attached to your computer (for example a PCI card, or a USB modem). remote is used when you have an ADSL router attached to an ethernet port of your computer. When one is using PPPoE pass-through, so there is an ethernet ADSL modem (not router) and PPP is running on the Linux host, the option to choose is local.

Note This special case has not yet been demonstrated for sure. Experiment a bit and if you ﬁnd out, let us know to update this page. In practice, this parameter lets the kernel know that the packets it sees, have already an ethernet header on them.

encapsulation can be one of (all the labels on the same line are aliases): IPoA-VC/Mux or ipoa-vcmux or ipoa-vc or ipoa-mux IPoA-LLC/SNAP or ipoa-llcsnap or ipoa-llc or ipoa-snap Bridged-VC/Mux or bridged-vcmux or bridged-vc or bridged-mux Bridged-LLC/SNAP or bridged-llcsnap or bridged-llc or bridged-snap PPPoA-VC/Mux or pppoa-vcmux or pppoa-vc or pppoa-mux PPPoA-LLC/SNAP or pppoa-llcsnap or pppoa-llc or pppoa-snap PPPoE-VC/Mux or pppoe-vcmux or pppoe-vc or pppoe-mux PPPoE-LLC/SNAP or pppoe-llcsnap or pppoe-llc or pppoe-snap If your adsl router can give you the mtu, it would be nice to add an mtu parameter too. For detailed info, see: http://ace-host.stuart.id.au/russell/files/tc/tc-atm/. mtu bytes Deﬁnes the MTU of the interface. FireQOS will query the interface to ﬁnd its MTU. You can overwrite this behaviour by giving this parameter to a class or interface. FireHOL + FireQOS Reference Release 2.0.0-pre7 197 / 215

mpu bytes Defines the MPU of the interface. FireQOS does not set a default value. You can set your own using this parameter. tsize size FireQOS does not set a default value. You can set your own using this parameter. overhead bytes FireQOS automatically calculates the overhead for ADSL. For all other technologies, you can specify the overhead in the config file. r2q factor FireQOS calculates the proper r2q, so that you can control speeds in steps of 1/100th of the interface speed (if that is possible).

Note The HTB manual states that this parameter is ignored when a quantum have been set. By default, FireQOS sets quantum to interface MTU, so r2q is probably is ignored by the kernel. burst bytes burst is the number of bytes that will be sent at once, at ceiling speed, when a class is allowed to send traffic. It is like a ’traffic unit’. A class is allowed to send at least burst bytes before trying to serve any other class. burst should never be lower that the interface mtu and class groups and interfaces should never have a smaller burst value than their children. If you do specify a higher burst for a child class, its parent may get stuck sometimes (the child will drain the parent). By default, FireQOS lets the kernel decide this parameter, which calculates the lowest possible value (the minimum value depends on the rate of the interface and the clock speed of the CPU). burst is inherited from interfaces to classes and from group classes to their subclasses. FireQOS will not allow you to set a burst at a subclass, higher than its parent. Setting a burst of a subclass higher than its parent will drain the parent class, which may be stuck for up to a minute when this happens. For this check to work, FireQOS uses just its configuration (it does not query the kernel to check how the value specified in the config file for a subclass relates to the actual value of its parent). cburst bytes cburst is like burst, but at hardware speed (not just ceiling speed). By default, FireQOS lets the kernel decide this parameter. cburst is inherited from interfaces to classes and from group classes to their subclasses. FireQOS will not allow you to set a cburst at a subclass, higher to its parent. Setting a cburst of a subclass higher than its parent, will drain the parent class, which may be stuck for up to a minute when this happens. For this check to work, FireQOS uses just its configuration (it does not query FireHOL + FireQOS Reference Release 2.0.0-pre7 198 / 215

the kernel to check how the value specified in the config file for a subclass relates to the actual value of its parent). quantum bytes quantum is the amount of bytes a class is allowed to send at once, when it is borrowing spare bandwidth from other classes. By default, FireQOS sets quantum to the interface mtu. quantum is inherited from interfaces to classes and from group classes to their subclasses. priority, balanced These parameters set the priority mode of the child classes. priority is the default mode, where FireQOS assigns an incremental priority to each class. In this mode, the first class takes prio 0, the second prio 1, etc. When a class has a higher prio than the others (higher = smaller number), this high priority class will get all the spare bandwidth available, when it needs it. Spare bandwidth will be allocate to lower priority classes only when the higher priority ones do not need it. balanced mode gives prio 4 to all child classes. When multiple classes have the same prio, the spare bandwidth available is spread among them, proportionally to their committed rate. The value 4 can be overwritten by setting FIREQOS_BALANCED_PRIO at the top of the config file to the prio you want the balanced mode to assign for all classes. The priority mode can be set in interfaces and class groups. The effect is the same. The classes that are defined as child classes, will get by default the calculated class prio based on the priority mode given. These options affect only the default prio that will be assigned by FireQOS. The default is used only if you don’t explicitly use a prio parameter on a class.

See Also

FireQOS program: fireqos(1) FireQOS configuration: fireqos.conf(5) interface definition: fireqos-interface(5) traffic class: fireqos-class(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 199 / 215

15.3 optional match parameters: ﬁreqos-match-params

Name

fireqos-match-params, fireqos-at, fireqos-match-class, fireqos-syn, fireqos-syns, fireqos-ack, fireqos-acks, fireqos-tos, fireqos-match-priority, fireqos-mark, fireqos-ports, fireqos-sports, fireqos-dports, fireqos-ip, fireqos-net, fireqos-host, fireqos-src, fireqos-dest, fireqos-match-prio — optional match parameters

Description

These options apply to match statements. at root|name By default a match is attached to the parent of its parent class. For example, if its parent is a class directly under the interface, then the match is attached to the interface and is compared against all trafﬁc of the interface. For nested classes, a match of a leaf, is attached to the parent class and is compared against all trafﬁc of this parent class. With the at parameter, a match can be attached any class. The name parameter should be a class name. The name root attaches the match to the interface. FireHOL + FireQOS Reference Release 2.0.0-pre7 200 / 215

class name Defines the name of the class that will get the packets matched by this match. By default it is the name of the class the match statement appears under. syn, syns Match TCP SYN packets. Note that the tcp parameter must be specified. If the same match statement includes more protocols than TCP, then this match will work for the TCP packets (it will be silently ignored for all other protocols). For example, syn is ignored when generating the UDP filter in the below: match tcp syn match proto tcp,udp syn ack, acks Same as syn, but matching TCP ACK packets. proto protocol[,protocol...], protocol protocol[,protocol...], tcp, udp, icmp, gre, ipv6 Match the protocol in the IP header. tos tosid[,tosid...], priority tosid[,tosid...] Match to TOS field of ipv4 or the priority field of ipv6. id can be a value/mask in any format tc accepts, or one of the following: min-delay, minimize-delay, minimum-delay, low-delay, interactive maximize-throughput, maximum-throughput, max-throughput, high-throughput, bulk maximize-reliability, maximum-reliability, max-reliability, reliable min-cost, minimize-cost, minimum-cost, low-cost, cheap normal-service, normal mark mark[,mark...] Match an iptables MARK. Matching iptables MARKs does not work on input interfaces. You can use them only on output. The IFB devices that are used for shaping inbound traffic do not have any iptables hooks to allow matching MARKs. If you try it, FireQOS will attempt to do it, but currently you will get an error from the tc command executed. ports port[:range][,port[:range]...], sports port[:range][,port[:range]...], dports port[: range][,port[:range]...] Match ports of the IP header. ports will create rules for matching source and destination ports (separate rules for each). dports matches destination ports, sports matches source ports. ip net[,net...], net net[,net...], host net[,net...], src net[,net...], dst net[,net...] Match IPs of the IP header. ip, net and host will create rules for matching source and destination IPs (separate rules for each). src matches source IPs and dst destination IPs. FireHOL + FireQOS Reference Release 2.0.0-pre7 201 / 215

Note If the class these matches appear in are IPv4, then only IPv4 IPs can be used. To override use match6 ... src/dst IPV6_IP. Similarly, if the class is IPv6, then only IPv6 IPs can be used. To override use match4 ... src/dst IPV4_IP. You can mix IPv4 and IPv6 in any way you like. FireQOS supports inheritance, to ﬁgure out for each statement which is the default. For example: interface46 eth0 lan output rate1Gbit# ipv4 and ipv6 enabled class voip# ipv4 and ipv6 class, as interface is both match udp port 53 # ipv4 and ipv6 rule, as class is both match4 src 192.0.2.1 # ipv4 only rule match6 src 2001:db8::1 # ipv6 only rule

class4 realtime# ipv4 only class match src 198.51.100.1 # ipv4 only rule, as class is ipv4-only

class6 servers# ipv6 only class match src 2001:db8::2 # ipv6 only rule, as class is ipv6-only

To convert an IPv4 interface to IPv6, just replace interface with interface6. All the rules in that interface, will automatically inherit the new protocol. Of course, if you use IP addresses for matching packets, make sure they are IPv6 IPs too.

prio id All match statements are attached to the interface. They forward traffic to their class, but they are actually executed for all packets that are leaving the interface (note: input matches are actually output matches on an IFB device). By default, the priority they are executed, is the priority they appear in the configuration file, i.e. the first match of the first class is executed first, then the rest matches of the first class in the sequence they appear, then the matches of the second class, etc. It is sometimes necessary to control the order of matches. For example, when you want host 192.0.2.1 to be assigned the first class, except port tcp/1234 which should be assigned the second class. The following will not work: interface eth0 lan output rate1Gbit class high match host 192.0.2.1

class low match host 192.0.2.1 port 1234 # Will never match

In this case, the first match is assigned priority 10 and the second priority 20. The second match will never match anything, since all traffic for the host is already matched by the first one. FireHOL + FireQOS Reference Release 2.0.0-pre7 202 / 215

Setting an explicit priority allows you to change the order in which the matches are executed. FireQOS gives priority 10 to the ﬁrst match of every interface, 20 to the second match, 30 to the third match, etc. So the default is 10 x the sequence number. You can set prio to overwrite this number. To force executing the second match before the ﬁrst, just set a lower priority for it. For example, this will cause the desired behaviour: interface eth0 lan output rate1Gbit class high match host 192.0.2.1

class low match host 192.0.2.1 port 1234 prio1# Matches before host-only

See Also

FireQOS program: fireqos(1) FireQOS configuration: fireqos.conf(5) traffic match: fireqos-match(5) FireHOL + FireQOS Reference Release 2.0.0-pre7 203 / 215

Part V

Appendices FireHOL + FireQOS Reference Release 2.0.0-pre7 204 / 215

Appendix A

ICMPv6 Firewall Recommendations

A.1 Introduction

RFC 4890 is entitled "Recommendations for Filtering ICMPv6 Messages in Firewalls". The recommendations pertain to ﬁrewalling at router level, not necessarily hosts or bridges (which may need to treat some packets differently, e.g. NS/NA and RS/RA). The sections below were extracted from the example implementation; each one describes how the recommendation can be achieved with FireHOL. It is assumed that a policy of reject or deny is in place. If that is not the case then some packet types need dropping explicitly to meet the recommendations.

A.2 Allow outbound echo requests from preﬁxes which belong to the site

The router command (see router definition: firehol-router(5)) should be used with an appropriate src rule parameter (see optional rule parameters: firehol-rule-params(5)).

A.3 Allow inbound echo requests towards only predetermined hosts

The ping - Ping (ICMP echo) should be used in combination with an appropriate dst rule parameter (see optional rule parameters: ﬁrehol-rule-params(5)). FireHOL + FireQOS Reference Release 2.0.0-pre7 205 / 215

A.4 Allow incoming and outgoing echo reply messages only for existing sessions

This is handled automatically by the ping - Ping (ICMP echo).

A.5 Deny icmps to/from link local addresses

The router command (see router definition: firehol-router(5)) should be used with an appropriate src and dst rule parameter (see optional rule parameters: firehol-rule-params(5)). For example: src not"${UNROUTABLE_IPS}" dst not"${UNROUTABLE_IPS}"

A.6 Drop echo replies which have a multicast address as a destination

The ping - Ping (ICMP echo) can be used with an appropriate src rule parameter (see optional rule parameters: ﬁrehol-rule-params(5)). For example: ipv6 route ping src not"${MULTICAST6_IPS}" will prevent incoming echo-requests from multicast IPs and replies to them.

A.7 Allow incoming destination unreachable messages only for existing sessions

Ensure any routers have: server ipv6error accept

Adding dst "$inner_preﬁx" ensures only public hosts receive the messages. See ipv6error - ICMPv6 Error Handling.

A.8 Allow outgoing destination unreachable messages

The rule(s) suggested by Section A.7 will also meet this recommendation. FireHOL + FireQOS Reference Release 2.0.0-pre7 206 / 215

A.9 Allow incoming Packet Too Big messages only for existing sessions