shorewall-rules

title: shorewall-rules(5)

summary: Shorewall rules file

text:
# shorewall-rules(5)

## NAME
rules - Shorewall rules file

## SYNOPSIS
/etc/shorewall[6]/rules

## DESCRIPTION
Entries in this file govern connection establishment by defining exceptions to the policies laid out in shorewall-policy[1](5). By default, subsequent requests and responses are automatically allowed using connection tracking. For any particular (source,dest) pair of zones, the rules are evaluated in the order in which they appear in this file and the first terminating match is the one that determines the disposition of the request. All rules are terminating except LOG and COUNT rules.

Warning

If you masquerade or use SNAT from a local system to the internet, you cannot use an ACCEPT rule to allow traffic from the internet to that system. You must use a DNAT rule instead.

The rules file is divided into sections. Each section is introduced by a "Section Header" which is a line beginning with ?SECTION and followed by the section name.

Sections are as follows and must appear in the order listed:

ALL

This section was added in Shorewall 4.4.23. Rules in this section are applied, regardless of the connection tracking state of the packet and are applied before rules in the other sections.

ESTABLISHED

Packets in the ESTABLISHED state are processed by rules in this section. The only ACTIONs allowed in this section are ACCEPT, DROP, REJECT, LOG, NFLOG, NFQUEUE and QUEUE

There is an implicit ACCEPT rule inserted at the end of this section.

RELATED

Packets in the RELATED state are processed by rules in this section. The only ACTIONs allowed in this section are ACCEPT, DROP, REJECT, LOG, NFLOG, NFQUEUE and QUEUE

There is an implicit rule added at the end of this section that invokes the RELATED_DISPOSITION (shorewall.conf[2](5)).

INVALID

Added in Shorewall 4.5.13. Packets in the INVALID state are processed by rules in this section. The only Actions allowed in this section are ACCEPT, DROP, REJECT, LOG, NFLOG, NFQUEUE and QUEUE.

There is an implicit rule added at the end of this section that invokes the INVALID_DISPOSITION (shorewall.conf[2](5)).

UNTRACKED

Added in Shorewall 4.5.13. Packets in the UNTRACKED state are processed by rules in this section. The only Actions allowed in this section are ACCEPT, DROP, REJECT, LOG, NFLOG, NFQUEUE and QUEUE.

There is an implicit rule added at the end of this section that invokes the UNTRACKED_DISPOSITION (shorewall.conf[2](5)).

NEW

Packets in the NEW state are processed by rules in this section. If the INVALID and/or UNTRACKED sections are empty or not included, then the packets in the corresponding state(s) are also processed in this section.

Note

If you are not familiar with Netfilter to the point where you are comfortable with the differences between the various connection tracking states, then it is suggested that you place all of your rules in the NEW section (That's after the line that reads ?SECTION NEW').

Warning

If you specify FASTACCEPT=Yes in shorewall.conf[2](5) then the ALL, ESTABLISHED and RELATED sections must be empty.

An exception is made if you are running Shorewall 4.4.27 or later and you have specified a non-default value for RELATED_DISPOSITION or RELATED_LOG_LEVEL. In that case, you may have rules in the RELATED section of this file.

You may omit any section that you don't need. If no Section Headers appear in the file then all rules are assumed to be in the NEW section.

When defining rules that rewrite the destination IP address and/or port number (namely DNAT and REDIRECT rules), it is important to keep straight which columns in the file specify the packet before rewriting and which specify how the packet will look after rewriting.

•The DEST column specifies the final destination for the packet after rewriting and can include the final IP address and/or port number.

•The remaining columns specify characteristics of the packet before rewriting. In particular, the ORIGDEST column gives the original destination IP address of the packet and the DPORT column give the original destination port(s).

The columns in the file are as follows (where the column name is followed by a different name in parentheses, the different name is used in the alternate specification syntax).

ACTION - target[:{log-level|none}[!][:tag]]

Specifies the action to be taken if the connection request matches the rule. target must be one of the following. ACCEPT

Allow the connection request.

ACCEPT+

like ACCEPT but also excludes the connection from any subsequent matching DNAT[-] or REDIRECT[-] rules. Use with IPv6 requires Shorewall 4.5.14 or later.

ACCEPT!

like ACCEPT but exempts the rule from being suppressed by OPTIMIZE=1 in shorewall.conf[2](5).

action

The name of an action declared in shorewall-actions[3](5) or in /usr/share/shorewall[6]/actions.std.

ADD(ipset:flags[:timeout])

Added in Shorewall 4.4.12. Causes addresses and/or port numbers to be added to the named ipset. The flags specify the address or tuple to be added to the set and must match the type of ipset involved. For example, for an iphash ipset, either the SOURCE or DESTINATION address can be added using flags src or dst respectively (see the -A command in ipset (8)). Beginning with Shorewall 5.0.3, an optional timeout can be specified. This is the number of seconds that the new entry in the ipset is to remain valid and overrides any timeout specified when the ipset was created.

ADD is non-terminating. Even if a packet matches the rule, it is passed on to the next rule.

AUDIT[(accept|drop|reject)]

Added in Shorewall 4.5.10. Audits the packet with the specified type; if the type is omitted, then drop is assumed. Require AUDIT_TARGET support in the kernel and iptables.

A_ACCEPT, A_ACCEPT+ and A_ACCEPT!

Added in Shorewall 4.4.20. Audited versions of ACCEPT, ACCEPT+ and ACCEPT! respectively. Require AUDIT_TARGET support in the kernel and iptables. A_ACCEPT+ with IPv6 requires Shorewall 4.5.14 or later.

A_DROP and A_DROP!

Added in Shorewall 4.4.20. Audited versions of DROP and DROP! respectively. Require AUDIT_TARGET support in the kernel and iptables.

A_REJECT AND A_REJECT!

Added in Shorewall 4.4.20. Audited versions of REJECT and REJECT! respectively. Require AUDIT_TARGET support in the kernel and iptables.

?COMMENT

the rest of the line will be attached as a comment to the Netfilter rule(s) generated by the following entries. The comment will appear delimited by "/* ... */" in the output of "shorewall show <chain>". To stop the comment from being attached to further rules, simply include ?COMMENT on a line by itself.

CONMARK({mark})

Added in Shorewall 5.0.7, CONNMARK is identical to MARK with the exception that the mark is assigned to connection to which the packet belongs is marked rather than to the packet itself.

CONTINUE

For experts only. Do not process any of the following rules for this (source zone,destination zone). If the source and/or destination IP address falls into a zone defined later in shorewall-zones[4](5) or in a parent zone of the source or destination zones, then this connection request will be passed to the rules defined for that (those) zone(s). See shorewall-nesting[5](5) for additional information.

CONTINUE!

like CONTINUE but exempts the rule from being suppressed by OPTIMIZE=1 in shorewall.conf[2](5).

COUNT

Simply increment the rule's packet and byte count and pass the packet to the next rule.

DEL(ipset:flags)

Added in Shorewall 4.4.12. Causes an entry to be deleted from the named ipset. The flags specify the address or tuple to be deleted from the set and must match the type of ipset involved. For example, for an iphash ipset, either the SOURCE or DESTINATION address can be deleted using flags src or dst respectively (see the -D command in ipset (8)). DEL is non-terminating. Even if a packet matches the rule, it is passed on to the next rule.

DNAT

Forward the request to another system (and optionally another port). Use with IPv6 requires Shorewall 4.5.14 or later.

DNAT-

Advanced users only. Like DNAT but only generates the DNAT iptables rule and not the companion ACCEPT rule. Use with IPv6 requires Shorewall 4.5.14 or later.

DROP

Ignore the request.

DROP!

like DROP but exempts the rule from being suppressed by OPTIMIZE=1 in shorewall.conf[2](5).

HELPER

Added in Shorewall 4.5.7. This action requires that the HELPER column contains the name of the Netfilter helper to be associated with connections matching this connection. May only be specified in the NEW section and is useful for being able to specify a helper when the applicable policy is ACCEPT. No destination zone should be specified in HELPER rules.

INLINE[(action)]

Added in Shorewall 4.5.16. This action allows you to construct most of the rule yourself using iptables syntax. The part that you specify must follow two semicolons (';;') and is completely free-form. If the target of the rule (the part following 'j') is something that Shorewall supports in the ACTION column, then you may enclose it in parentheses (e.g., INLINE(ACCEPT)). Otherwise, you can include it after the semicolon(s). In this case, you must declare the target as a builtin action in shorewall-actions[3](5). Some considerations when using INLINE:

•The p, s, d, i, o, policy, and state match (state or conntrack --ctstate) matches will always appear in the front of the rule in that order.

•When multiple matches are specified, the compiler will keep them in the order in which they appear (excluding the above listed ones), but they will not necessarily be at the end of the generated rule. For example, if addresses are specified in the SOURCE and/or DEST columns, their generated matches will appear after those specified using ';;' or ';'.

IPTABLES({iptables-target [option ...])

IPv4 only. This action allows you to specify an iptables target with options (e.g., 'IPTABLES(MARK --set-xmark 0x01/0xff)'. If the iptables-target is not one recognized by Shorewall, the following error message will be issued:

```
    ERROR: Unknown target (iptables-target)
```

This error message may be eliminated by adding the iptables-target as a builtin action in shorewall-actions[3](5).

Important

If you specify REJECT as the iptables-target, the target of the rule will be the iptables REJECT target and not Shorewall's builtin 'reject' chain which is used when REJECT (see below) is specified as the target in the ACTION column.

IP6TABLES({ip6tables-target [option ...])

IPv6 only. This action allows you to specify an ip6tables target with options (e.g., 'IPTABLES(MARK --set-xmark 0x01/0xff)'. If the ip6tables-target is not one recognized by Shorewall, the following error message will be issued:

```
    ERROR: Unknown target (ip6tables-target)
```

This error message may be eliminated by adding the ip6tables-target as a builtin action in shorewall-actions[3](5).

Important

If you specify REJECT as the ip6tables-target, the target of the rule will be the i6ptables REJECT target and not Shorewall's builtin 'reject' chain which is used when REJECT (see below) is specified as the target in the ACTION column.

LOG:level

Simply log the packet and continue with the next rule.

macro[(macrotarget)]

The name of a macro defined in a file named macro.macro. If the macro accepts an action parameter (Look at the macro source to see if it has PARAM in the TARGET column) then the macro name is followed by the parenthesized macrotarget (ACCEPT, DROP, REJECT, ...) to be substituted for the parameter. Example: FTP(ACCEPT).

The older syntax where the macro name and the target are separated by a slash (e.g. FTP/ACCEPT) is still allowed but is deprecated.

MARK({mark})

where mark is a packet mark value. Added in Shorewall 5.0.7, MARK requires "Mark in filter table" support in your kernel and iptables.

Normally will set the mark value of the current packet. If preceded by a vertical bar ("|"), the mark value will be logically ORed with the current mark value to produce a new mark value. If preceded by an ampersand ("&"), will be logically ANDed with the current mark value to produce a new mark value.

Both "|" and "&" require Extended MARK Target support in your kernel and iptables.

The mark value may be optionally followed by "/" and a mask value (used to determine those bits of the connection mark to actually be set). When a mask is specified, the result of logically ANDing the mark value with the mask must be the same as the mark value.

NFLOG[(nflog-parameters)]

Added in Shorewall 4.5.9.3. Queues matching packets to a back end logging daemon via a netlink socket then continues to the next rule. See https://shorewall.org/shorewall_logging.html[6]. The nflog-parameters are a comma-separated list of up to 3 numbers:

•The first number specifies the netlink group (0-65535). If omitted (e.g., NFLOG(,0,10)) then a value of 0 is assumed.

•The second number specifies the maximum number of bytes to copy. If omitted, 0 (no limit) is assumed.

•The third number specifies the number of log messages that should be buffered in the kernel before they are sent to user space. The default is 1.

NFLOG is similar to LOG:NFLOG[(nflog-parameters)], except that the log level is not changed when this ACTION is used in an action or macro body and the invocation of that action or macro specifies a log level.

NFQUEUE[([queuenumber1[:queuenumber2[c]][,bypass]]|bypass)]

Queues the packet to a user-space application using the nfnetlink_queue mechanism. If a queuenumber1 is not specified, queue zero (0) is assumed. Beginning with Shorewall 4.6.10, the keyword bypass can be given. By default, if no userspace program is listening on an NFQUEUE, then all packets that are to be queued are dropped. When this option is used, the NFQUEUE rule behaves like ACCEPT instead. Also beginning in Shorewall 4.6.10, a second queue number (queuenumber2) may be specified. This specifies a range of queues to use. Packets are then balanced across the given queues. This is useful for multicore systems: start multiple instances of the userspace program on queues x, x+1, .. x+n and use "x:x+n". Packets belonging to the same connection are put into the same nfqueue. Beginning with Shorewall 5.1.0, queuenumber2 may be followed by the letter 'c' to indicate that the CPU ID will be used as an index to map packets to the queues. The idea is that you can improve performance if there's a queue per CPU. Requires the NFQUEUE CPU Fanout capability in your kernel and iptables.

NFQUEUE![([queuenumber1[:queuenumber2[c]][,bypass]]|bypass)]

like NFQUEUE but exempts the rule from being suppressed by OPTIMIZE=1 in shorewall.conf[2](5).

NONAT

Excludes the connection from any subsequent DNAT[-] or REDIRECT[-] rules but doesn't generate a rule to accept the traffic. Use with IPv6 requires Shorewall 4.5.14 or later.

QUEUE

Queue the packet to a user-space application such as ftwall (http://p2pwall.sf.net). The application may reinsert the packet for further processing.

QUEUE!

like QUEUE but exempts the rule from being suppressed by OPTIMIZE=1 in shorewall.conf[2](5).

REJECT[(option)]

disallow the request and return an icmp-unreachable or an RST packet. If no option is passed, Shorewall selects the appropriate option based on the protocol of the packet. Beginning with Shorewall 5.0.8, the type of reject may be specified in the option paramater. Valid IPv4 option values are:

icmp-net-unreachable

icmp-host-unreachable

icmp-port-unreachable

icmp-proto-unreachable

icmp-net-prohibited

icmp-host-prohibited

icmp-admin-prohibited

icmp-tcp-reset (the PROTO column

must specify TCP). Beginning with Shorewall 5.1.3, this

option may also be specified as

tcp-reset.

Valid IPv6 option values are: icmp6-no-route

no-route

icmp6-adm-prohibited

adm-prohibited

icmp6-addr-unreachable

addr-unreach

icmp6-port-unreachable

tcp-reset (the PROTO column must

specify TCP)

REJECT!

like REJECT but exempts the rule from being suppressed by OPTIMIZE=1 in shorewall.conf[2](5).

REDIRECT

Redirect the request to a server running on the firewall. Use with IPv6 requires Shorewall 4.5.14 or later.

REDIRECT-

Advanced users only. Like REDIRECT but only generates the REDIRECT iptables rule and not the companion ACCEPT rule. Use with IPv6 requires Shorewall 4.5.14 or later.

TARPIT [(tarpit | honeypot | reset)]

Added in Shorewall 4.6.6. TARPIT captures and holds incoming TCP connections using no local per-connection resources.

TARPIT only works with the PROTO column set to tcp (6), and is totally application agnostic. This module will answer a TCP request and play along like a listening server, but aside from sending an ACK or RST, no data is sent. Incoming packets are ignored and dropped. The attacker will terminate the session eventually. This module allows the initial packets of an attack to be captured by other software for inspection. In most cases this is sufficient to determine the nature of the attack.

This offers similar functionality to LaBrea <http://www.hackbusters.net/LaBrea/> but does not require dedicated hardware or IPs. Any TCP port that you would normally DROP or REJECT can instead become a tarpit.

The target accepts a single optional parameter:

tarpit

This mode is the default and completes a connection with the attacker but limits the window size to 0, thus keeping the attacker waiting long periods of time. While he is maintaining state of the connection and trying to continue every 60-240 seconds, we keep none, so it is very lightweight. Attempts to close the connection are ignored, forcing the remote side to time out the connection in 12-24 minutes.

honeypot

This mode completes a connection with the attacker, but signals a normal window size, so that the remote side will attempt to send data, often with some very nasty exploit attempts. We can capture these packets for decoding and further analysis. The module does not send any data, so if the remote expects an application level response, the game is up.

reset

This mode is handy because we can send an inline RST (reset). It has no other function.

ULOG[(ulog-parameters)]

IPv4 only. Added in Shorewall 4.5.10. Queues matching packets to a back end logging daemon via a netlink socket then continues to the next rule. See shorewall-logging(5)[7]. Similar to LOG:ULOG[(ulog-parameters)], except that the log level is not changed when this ACTION is used in an action or macro body and the invocation of that action or macro specifies a log level.

The target may optionally be followed by ":" and a syslog log level (e.g, REJECT:info or Web(ACCEPT):debug). This causes the packet to be logged at the specified level. Note that if the ACTION involves destination network address translation (DNAT, REDIRECT, etc.) then the packet is logged before the destination address is rewritten.

If the ACTION names an action declared in shorewall-actions[3](5) or in /usr/share/shorewall/actions.std then:

•If the log level is followed by "!' then all rules in the action are logged at the log level.

•If the log level is not followed by "!" then only those rules in the action that do not specify logging are logged at the specified level.

•The special log level none! suppresses logging by the action.

You may also specify ULOG (IPv4 only) or NFLOG (must be in upper case) as a log level.This will log to the ULOG or NFLOG target for routing to a separate log through use of ulogd (shorewall-logging(5)[7]).

Actions specifying logging may be followed by a log tag (a string of alphanumeric characters) which is appended to the string generated by the LOGPREFIX (in shorewall.conf[2](5)).

Example: ACCEPT:info:ftp would include 'ftp ' at the end of the log prefix generated by the LOGPREFIX setting.

SOURCE - source-spec[,...]

Source hosts to which the rule applies. source-spec is one of the following:

zone[,...[+]]

The name of a zone defined in shorewall-zones[4](5). When only the zone name is specified, the packet source may be any host in that zone. zone may also be one of the following:

all[+]

all, without the "-" means "All Zones, including the firewall zone". Normally all omits intra-zone traffic, but intra-zone traffic can be included specifying "+".

any[+]

any is equivalent to all when there are no nested zones. When there are nested zones, any only refers to top-level zones (those with no parent zones). Note that any excludes all vserver zones, since those zones are nested within the firewall zone.

none

When none is used either in the SOURCE or DEST column, the rule is ignored.

Similar to with all and any, intra-zone traffic is normally excluded when multiple zones are listed. Intra-zone traffic may be included by following the list with a plus sign ("+").

all and any may be followed by an exclamation point ("!") and a comma-separated list of zone names to be omitted.

zone:[!]interface

When this form is used, interface must be the name of an interface associated with the named zone in either shorewall-interfaces[8](5) or shorewall-hosts[9](5). Only packets from hosts in the zone that arrive through the named interface will match the rule. Beginning with Shorweall 5.2.1, the interface may be preceded with '!' which matches all interfaces associated with the zone except the one specified.

zone:address[,...]

where address can be:

•A host or network IP address. A network address may be followed by exclusion (see shorewall-exclusion[10](5)).

•An address range, specified using the syntax lowaddress-highaddress.

•+ipset where ipset is the name of an ipset and must be preceded by a plus sign ("+").

•A MAC address in Shorewall format (preceded by a tilde ("~") and with the hex byte values separated by dashes (e.g., "~00-0a-f6-04-9c-7d").

•^country-code where country-code is a two-character ISO-3661 country code preceded by a caret ("^").

•^country-code-list where country-code-list is a comma-separated list of up to 15 ISO-3661 country codes enclosed in square brackets ("[...]").

•The primary IP address of a firewall interface can be specified by an ampersand ('&') followed by the logical name of the interface as found in the INTERFACE column of shorewall-interfaces[8] (5).

zone:interface:address[,...]

This form combines the preceding two and requires that both the incoming interface and source address match.

zone:exclusion

This form matches if the host IP address does not match any of the entries in the exclusion (see shorewall-exclusion[10](5)).

zone:interface:exclusion

This form matches packets from the named zone entering through the specified interface where the source address does not match any entry in the exclusion.

Beginning with Shorewall 5.1.0, multiple source-specs may be listed, provided that extended forms of the source-spec are used: zone:(interface)

zone:(address[,...])

zone:(interface:address[,...])

zone:(exclusion)

zone:(interface:exclusion) Examples:

dmz:192.168.2.2

Host 192.168.2.2 in the DMZ

net:155.186.235.0/24

Subnet 155.186.235.0/24 on the Internet

loc:192.168.1.1,192.168.1.2

Hosts 192.168.1.1 and 192.168.1.2 in the local zone.

loc:~00-A0-C9-15-39-78

Host in the local zone with MAC address 00:A0:C9:15:39:78.

net:192.0.2.11-192.0.2.17

Hosts 192.0.2.11-192.0.2.17 in the net zone.

net:!192.0.2.11-192.0.2.17

All hosts in the net zone except for 192.0.2.11-192.0.2.17.

net:155.186.235.0/24!155.186.235.16/28

Subnet 155.186.235.0/24 on the Internet except for 155.186.235.16/28

$FW:&eth0

The primary IP address of eth0 in the firewall zone.

loc,dmz

Both the loc and dmz zones.

all!dmz

All but the dmz zone.

all+!$FW

All but the firewall zone and applies to intrazone traffic.

net:^CN

China.

loc:(eth1:1.2.3.4,2.3.4.5),dmz:(eth2:5.6.7.8,9.10.11.12),net

Hosts 1.2.3.4 and 2.3.4.5 in the loc zone when the packet arrives through eth1 plus hosts 5.6.7.8 and 9.10.11.12 in the dmz zone when the packet arrives through eth2 plus all of the net zone.

dmz:[2002:ce7c:2b4:1::2]

Host 2002:ce7c:92b4:1::2 in the DMZ

net:2001:4d48:ad51:24::/64

Subnet 2001:4d48:ad51:24::/64 on the Internet

loc:[2002:cec792b4:1::2],[2002:cec792b4:1::44]

Hosts 2002:cec792b4:1::2 and 2002:cec792b4:1::44 in the local zone.

loc:~00-A0-C9-15-39-78

Host in the local zone with MAC address 00:A0:C9:15:39:78.

net:[2001:4d48:ad51:24::]/64![2001:4d48:ad51:24:6::]/80

Subnet 2001:4d48:ad51:24::/64 on the Internet except for 2001:4d48:ad51:24:6::/80.

DEST - dest-spec[,...]

Destination hosts to which the rule applies. dest-spec is one of the following:

zone[,...[+]]

The name of a zone defined in shorewall-zones[4](5). When only the zone name is specified, the packet destination may be any host in that zone. zone may also be one of the following:

all[+]

all, without the "-" means "All Zones, including the firewall zone". Normally all omits intra-zone traffic, but intra-zone traffic can be included specifying "+".

any[+]

any is equivalent to all when there are no nested zones. When there are nested zones, any only refers to top-level zones (those with no parent zones). Note that any excludes all vserver zones, since those zones are nested within the firewall zone.

none

When none is used either in the SOURCE or DEST column, the rule is ignored.

Similar to with all and any, intra-zone traffic is normally excluded when multiple zones are listed. Intra-zone traffic may be included by following the list with a plus sign ("+").

all and any may be followed by an exclamation point ("!") and a comma-separated list of zone names to be omitted.

zone:[!]interface

When this form is used, interface must be the name of an interface associated with the named zone in either shorewall-interfaces[8](5) or shorewall-hosts[11](5). Only packets to hosts in the zone that are sent through the named interface will match the rule. Beginning with Shorweall 5.2.1, the interface may be preceded with '!' which matches all interfaces associated with the zone except the one specified.

zone:address[,...]

where address can be:

•A host or network IP address. A network address may be followed by exclusion (see shorewall-exclusion[10](5)).

•An address range, specified using the syntax lowaddress-highaddress.

•+ipset where ipset is the name of an ipset and must be preceded by a plus sign ("+").

•^country-code where country-code is a two-character ISO-3661 country code preceded by a caret ("^").

•^country-code-list where country-code-list is a comma-separated list of up to 15 ISO-3661 country codes enclosed in square brackets ("[...]").

•The primary IP address of a firewall interface can be specified by an ampersand ('&') followed by the logical name of the interface as found in the INTERFACE column of shorewall-interfaces[8] (5).

zone:[!]interface:address[,...]

This form combines the preceding two and requires that both the outgoing interface and destinationaddress match. Beginning with Shorweall 5.2.1, the interface may be preceded with '!' which matches all interfaces associated with the zone except the one specified.

zone:exclusion

This form matches if the host IP address does not match any of the entries in the exclusion (see shorewall-exclusion[10](5)).

zone:[!]interface:exclusion

This form matches packets to the named zone leaving through the specified interface where the destination address does not match any entry in the exclusion. Beginning with Shorweall 5.2.1, the interface may be preceded with '!' which matches all interfaces associated with the zone except the one specified.

[zone]:[server-IP][:port-or-port-range[:random]]

This form applies when the ACTION is DNAT[-] or REDIRECT[-]. The zone may be omitted in REDIRECT rules ($FW is assumed) and must be omitted in DNAT-, REDIRECT- and NONAT rules. server-IP is not allowed in REDIRECT rules and may be omitted in DNAT[-] rules provided that port-or-port-range is included.

•The IP address of the server to which the packet is to be sent.

•A range of IP address with the low and high address separated by a dash (:"-"). Connections are distributed among the IP addresses in the range.

If server-IP is omitted in a DNAT[-] rule, only the destination port number is modified by the rule.

port-or-port-range may be:

•An integer port number in the range 1 - 65535.

•The name of a service from /etc/services.

•A port range with the low and high integer port numbers separated by a dash ("-"). Connections are distributed among the ports in the range.

If random is specified, port mapping will be randomized.

If the DEST zone is a bport zone, then either:

1.the SOURCE must be all[+], or

2.the SOURCE zone must be another bport zone associated with the same bridge, or

3.the SOURCE zone must be an ipv4 zone that is associated with only the same bridge.

Beginning with Shorewall 5.1.0, multiple dest-specs may be listed, provided that extended forms of the source-spec are used: zone:(interface)

zone:(address[,...])

zone:(interface:address[,...])

zone:(exclusion)

zone:(interface:exclusion) Multiple dest-specs are not permitted in DNAT[-] and REDIRECT[-] rules.

Examples:

dmz:192.168.2.2

Host 192.168.2.2 in the DMZ

net:155.186.235.0/24

Subnet 155.186.235.0/24 on the Internet

loc:192.168.1.1,192.168.1.2

Hosts 192.168.1.1 and 192.168.1.2 in the local zone.

net:192.0.2.11-192.0.2.17

Hosts 192.0.2.11-192.0.2.17 in the net zone.

net:!192.0.2.11-192.0.2.17

All hosts in the net zone except for 192.0.2.11-192.0.2.17.

net:155.186.235.0/24!155.186.235.16/28

Subnet 155.186.235.0/24 on the Internet except for 155.186.235.16/28

$FW:&eth0

The primary IP address of eth0 in the firewall zone.

loc,dmz

Both the loc and dmz zones.

all!dmz

All but the dmz zone.

net:^CN

China.

dmz:192.168.10.4:25

Port 25 on server 192.168.10.4 in the dmz zone (DNAT rule).

loc:(eth1:1.2.3.4,2.3.4.5),dmz:(eth2:5.6.7.8,9.10.11.12),net

Hosts 1.2.3.4 and 2.3.4.5 in the loc zone when the packet arrives through eth1 plus hosts 5.6.7.8 and 9.10.11.12 in the dmz zone when the packet arrives through eth2 plus all of the net zone.

PROTO- {-|tcp:[!]syn|ipp2p|ipp2p:udp|ipp2p:all|protocol-number|protocol-name|all}

Optional Protocol - ipp2p* requires ipp2p match support in your kernel and iptables. tcp:syn implies tcp plus the SYN flag must be set and the RST, ACK and FIN flags must be reset. Beginning with Shorewall 5.1.3, you may also specify tcp:!syn, which matches if SYN is not set or if RST, ACK or FIN is set. Beginning with Shorewall 4.4.19, this column can contain a comma-separated list of protocol-numbers and/or protocol names.

DPORT - {-|port-name-number-or-range[,port-name-number-or-range]...|+ipset}

Optional destination Ports. A comma-separated list of Port names (from services(5)), port numbers or port ranges; if the protocol is icmp, this column is interpreted as the destination icmp-type(s). ICMP types may be specified as a numeric type, a numeric type and code separated by a slash (e.g., 3/4), or a typename. See https://shorewall.org/configuration_file_basics.htm#ICMP[12]. Note that prior to Shorewall 4.4.19, only a single ICMP type may be listed. If the protocol is ipp2p, this column is interpreted as an ipp2p option without the leading "--" (example bit for bit-torrent). If no port is given, ipp2p is assumed.

A port range is expressed as lowport:highport.

This column is ignored if PROTO = all but must be entered if any of the following columns are supplied. In that case, it is suggested that this field contain a dash (-).

If your kernel contains multi-port match support, then only a single Netfilter rule will be generated if in this list and the SPORT list below:

1. There are 15 or less ports listed.

2. No port ranges are included or your kernel and iptables contain extended multi-port match support.

Beginning with Shorewall 4.6.0, an ipset name can be specified in this column. This is intended to be used with bitmap:port ipsets.

This column was formerly labelled DEST PORT(S).

SPORT - {-|port-name-number-or-range[,port-name-number-or-range]...|+ipset}

Optional port(s) used by the client. If omitted, any source port is acceptable. Specified as a comma- separated list of port names, port numbers or port ranges. Beginning with Shorewall 4.5.15, you may place '=' in this column, provided that the DPORT column is non-empty. This causes the rule to match when either the source port or the destination port in a packet matches one of the ports specified in DEST PORTS(S). Use of '=' requires multi-port match in your iptables and kernel.

Warning

Unless you really understand IP, you should leave this column empty or place a dash (-) in the column. Most people who try to use this column get it wrong.

If you don't want to restrict client ports but need to specify an ORIGDEST in the next column, then place "-" in this column. If your kernel contains multi-port match support, then only a single Netfilter rule will be generated if in this list and the DPORT list above:

1. There are 15 or less ports listed.

2. No port ranges are included or your kernel and iptables contain extended multi-port match support.

Beginning with Shorewall 4.6.0, an ipset name can be specified in this column. This is intended to be used with bitmap:port ipsets.

This column was formerly labelled SOURCE PORT(S).

ORIGDEST - [-|address[,address]...[exclusion]|exclusion]

Optional. If ACTION is DNAT[-] or REDIRECT[-] then if this column is included and is different from the IP address given in the DEST column, then connections destined for that address will be forwarded to the IP and port specified in the DEST column. A comma-separated list of addresses may also be used. This is most useful with the REDIRECT target where you want to redirect traffic destined for particular set of hosts. Finally, if the list of addresses begins with "!" (exclusion) then the rule will be followed only if the original destination address in the connection request does not match any of the addresses listed.

Beginning with Shorewall 4.4.17, the primary IP address of a firewall interface can be specified by an ampersand ('&') followed by the logical name of the interface as found in the INTERFACE column of shorewall-interfaces[8] (5).

For other actions, this column may be included and may contain one or more addresses (host or network) separated by commas. Address ranges are not allowed. When this column is supplied, rules are generated that require that the original destination address matches one of the listed addresses. This feature is most useful when you want to generate a filter rule that corresponds to a DNAT- or REDIRECT- rule. In this usage, the list of addresses should not begin with "!".

It is also possible to specify a set of addresses then exclude part of those addresses. For example, 192.168.1.0/24!192.168.1.16/28 specifies the addresses 192.168.1.0-182.168.1.15 and 192.168.1.32-192.168.1.255. See shorewall-exclusion[10](5).

See https://shorewall.org/PortKnocking.html[13] for an example of using an entry in this column with a user-defined action rule.

This column was formerly labelled ORIGINAL DEST.

RATE - limit

where limit is one of: [-|[{s|d}[/vlsm]:[name[(ht-buckets,ht-max)]:]rate/{sec|min|hour|day}[:burst]

[s[/vlsm1]:][name1[(ht-buckets1,ht-max1)]:]rate1/{sec|min|hour|day}[:burst1],[d[/vlsm2:][name2[(ht-buckets2,ht-max2)]:]rate2/{sec|min|hour|day}[:burst2]

You may optionally rate-limit the rule by placing a value in this column: rate* is the number of connections per interval (sec or min) and burst* is the largest burst permitted. If no burst is given, a value of 5 is assumed. There may be no no white-space embedded in the specification.

Example: 10/sec:20

When s: or d: is specified, the rate applies per source IP address or per destination IP address respectively. The names may be chosen by the user and specify a hash table to be used to count matching connections. If not given, the name shorewallN (where N is a unique integer) is assumed. Where more than one rule or POLICY specifies the same name, the connections counts for the rules are aggregated and the individual rates apply to the aggregated count. Beginning with Shorewall 5.2.1, the s or d may be followed by a slash ("/") and an integer vlsm. When a vlsm is specified, all source or destination addresses encountered will be grouped according to the given prefix length and the so-created subnet will be subject to the rate limit.

Example: s/24::10/sec

Beginning with Shorewall 4.6.5, two limits may be specified, separated by a comma. In this case, the first limit (name1, rate1, burst1) specifies the per-source IP limit and the second limit specifies the per-destination IP limit.

Example: client:10/sec:20,:60/sec:100

In this example, the 'client' hash table will be used to enforce the per-source limit and the compiler will pick a unique name for the hash table that tracks the per-destination limit.

Beginning with Shorewall 5.2.1, the table name, if any, may be followed by two integers separated by commas and enclosed in parentheses. The first integer (ht-buckets) specifies the number of buckets in the generated hash table. The second integer (ht-max) specifies the maximum number of entries in the hash table.

Example: s:netfw(1024,65536):10/sec

This column was formerly labelled RATE LIMIT.

USER - [!][user-name-or-number][:group-name-or-number][,...]

This optional column may only be non-empty if the SOURCE is the firewall itself. When this column is non-empty, the rule applies only if the program generating the output is running under the effective user and/or group specified (or is NOT running under that id if "!" is given).

Beginning with Shorewall 4.5.8, multiple user or group names/ids separated by commas may be specified.

Examples:

joe

program must be run by joe

:kids

program must be run by a member of the 'kids' group

!:kids

program must not be run by a member of the 'kids' group

2001-2099

UIDs 2001 through 2099 (Shorewall 4.5.6 and later)

This column was formerly labelled USER/GROUP.

MARK - [!]value[/mask][:C]

Defines a test on the existing packet or connection mark. The rule will match only if the test returns true. If you don't want to define a test but need to specify anything in the following columns, place a "-" in this field.

!

Inverts the test (not equal)

value

Value of the packet or connection mark.

mask

A mask to be applied to the mark before testing.

:C

Designates a connection mark. If omitted, the packet mark's value is tested.

CONNLIMIT - [d:][!]limit[:mask]

May be used to limit the number of simultaneous connections to/from each individual host or network to limit connections. Requires connlimit match in your kernel and iptables. While the limit is only checked on rules specifying CONNLIMIT, the number of current connections is calculated over all current connections from the SOURCE or DESTINATION host. By default, limiting is done by SOURCE host or net, but if the specification begins with d:, then limiting will be donw by destination host or net. By default, the limit is applied to each host but can be made to apply to networks of hosts by specifying a mask. The mask specifies the width of a VLSM mask to be applied to the source address; the number of current connections is then taken over all hosts in the subnet source-address/mask. When ! is specified, the rule matches when the number of connection exceeds the limit.

TIME - timeelement[&timeelement...]

May be used to limit the rule to a particular time period each day, to particular days of the week or month, or to a range defined by dates and times. Requires time match support in your kernel and iptables. timeelement may be:

timestart=hh:mm[:ss]

Defines the starting time of day.

timestop=hh:mm[:ss]

Defines the ending time of day.

contiguous

Added in Shoreawll 5.0.12. When timestop is smaller than timestart value, match this as a single time period instead of distinct intervals.

utc

Times are expressed in Greenwich Mean Time.

localtz

Deprecated by the Netfilter team in favor of kerneltz. Times are expressed in Local Civil Time (default).

kerneltz

Added in Shorewall 4.5.2. Times are expressed in Local Kernel Time (requires iptables 1.4.12 or later).

weekdays=ddd[,ddd]...

where ddd is one of Mon, Tue, Wed, Thu, Fri, Sat or Sun

monthdays=dd[,dd],...

where dd is an ordinal day of the month

datestart=yyyy[-mm[-dd[Thh[:mm[:ss]]]]]

Defines the starting date and time.

datestop=yyyy[-mm[-dd[Thh[:mm[:ss]]]]]

Defines the ending date and time.

HEADERS - [!][any:|exactly:]header-list (Optional - Added in Shorewall 4.4.15)

This column is only used in IPv6. In IPv4, supply "-" in this column if you with to place a value in one of the following columns. The header-list consists of a comma-separated list of headers from the following list.

auth, ah, or 51

Authentication Headers extension header.

esp, or 50

Encrypted Security Payload extension header.

hop, hop-by-hop or 0

Hop-by-hop options extension header.

route, ipv6-route or 43

IPv6 Route extension header.

frag, ipv6-frag or 44

IPv6 fragmentation extension header.

none, ipv6-nonxt or 59

No next header

proto, protocol or 255

Any protocol header.

If any: is specified, the rule will match if any of the listed headers are present. If exactly: is specified, the will match packets that exactly include all specified headers. If neither is given, any: is assumed.

If ! is entered, the rule will match those packets which would not be matched when ! is omitted.

SWITCH - [!]switch-name[={0|1}]

Added in Shorewall 4.4.24 and allows enabling and disabling the rule without requiring shorewall reload. The rule is enabled if the value stored in /proc/net/nf_condition/switch-name is 1. The rule is disabled if that file contains 0 (the default). If '!' is supplied, the test is inverted such that the rule is enabled if the file contains 0.

Within the switch-name, '@0' and '@{0}' are replaced by the name of the chain to which the rule is a added. The switch-name (after '@...' expansion) must begin with a letter and be composed of letters, decimal digits, underscores or hyphens. Switch names must be 30 characters or less in length.

Switches are normally off. To turn a switch on:

echo 1 >

/proc/net/nf_condition/switch-name

To turn it off again: echo 0 >

/proc/net/nf_condition/switch-name

Switch settings are retained over shorewall reload. Beginning with Shorewall 4.5.10, when the switch-name is followed by =0 or =1, then the switch is initialized to off or on respectively by the start command. Other commands do not affect the switch setting.

HELPER - [helper]

Added in Shorewall 4.5.7. In the NEW section, causes the named conntrack helper to be associated with this connection; the contents of this column are ignored unless ACTION is ACCEPT*, DNAT* or REDIRECT*.

In the RELATED section, will only match if the related connection has the named helper associated with it.

The helper may be one of:

amanda

ftp

irc

netbios-ns

pptp

Q.931

RAS

sane

sip

snmp

tftp

If the HELPERS option is specified in shorewall.conf[2](5), then any module specified in this column must be listed in the HELPERS setting.

## EXAMPLES
Example 1:

Accept SMTP requests from the DMZ to the internet

```
         #ACTION SOURCE  DEST      PROTO      DPORT   SPORT   ORIGDEST

         ACCEPT  dmz     net       tcp        smtp
```

Example 2:

Forward all ssh and http connection requests from the internet to local system 192.168.1.3

```
        #ACTION SOURCE  DEST            PROTO   DPORT   SPORT   ORIGDEST

        DNAT    net     loc:192.168.1.3 tcp     ssh,http
```

Example 3:

Forward all http connection requests from the internet to local system 192.168.1.3 with a limit of 3 per second and a maximum burst of 10

```
        #ACTION SOURCE DEST             PROTO  DPORT SPORT   ORIGDEST RATE

        DNAT    net    loc:192.168.1.3  tcp    http  -       -        3/sec:10
```

Example 4:

Redirect all locally-originating www connection requests to port 3128 on the firewall (Squid running on the firewall system) except when the destination address is 192.168.2.2

```
        #ACTION  SOURCE DEST      PROTO DPORT   SPORT   ORIGDEST

        REDIRECT loc    3128      tcp   www      -      !192.168.2.2
```

Example 5:

All http requests from the internet to address 130.252.100.69 are to be forwarded to 192.168.1.3

```
        #ACTION  SOURCE DEST            PROTO   DPORT   SPORT   ORIGDEST

        DNAT      net   loc:192.168.1.3 tcp     80      -       130.252.100.69
```

Example 6:

You want to accept SSH connections to your firewall only from internet IP addresses 130.252.100.69 and 130.252.100.70

```
        #ACTION  SOURCE DEST            PROTO   DPORT   SPORT   ORIGDEST

        ACCEPT   net:130.252.100.69,130.252.100.70 \

                        $FW             tcp     22
```

Example 7:

You wish to accept connections from the internet to your firewall on port 2222 and you want to forward them to local system 192.168.1.3, port 22

```
        #ACTION  SOURCE DEST                PROTO   DPORT   SPORT   ORIGDEST

        DNAT     net    loc:192.168.1.3:22  tcp     2222
```

Example 8:

You want to redirect connection requests to port 80 randomly to the port range 81-90.

```
        #ACTION  SOURCE DEST                PROTO DPORT   SPORT   ORIGDEST

        REDIRECT net    $FW::81-90:random   tcp   www
```

Example 9:

Shorewall does not impose as much structure on the Netfilter rules in the 'nat' table as it does on those in the filter table. As a consequence, when using Shorewall versions before 4.1.4, care must be exercised when using DNAT and REDIRECT rules with zones defined with wildcard interfaces (those ending with '+'. Here is an example: shorewall-zones[4](5):

```
        #ZONE       TYPE    OPTIONS

        fw          firewall

        net         ipv4

        dmz         ipv4

        loc         ipv4
```

shorewall-interfaces[8](5):

```
        #ZONE       INTERFACE       BROADCAST      OPTIONS

        net         ppp0

        loc         eth1            detect

        dmz         eth2            detect

        -           ppp+                           # Addresses are assigned from 192.168.3.0/24
```

shorewall-host[11](5):

```
        #ZONE       HOST(S)              OPTIONS

        loc         ppp+:192.168.3.0/24
```

rules:

```
        #ACTION     SOURCE          DEST       PROTO       DPORT

        REDIRECT    loc             3128       tcp         80
```

Note that it would have been tempting to simply define the loc zone entirely in shorewall-interfaces(8):

```
        #******************* INCORRECT *****************

        #ZONE       INTERFACE       BROADCAST      OPTIONS

        net         ppp0

        loc         eth1            detect

        loc         ppp+

        dmz         eth2
```

This would have made it impossible to run a internet-accessible web server in the DMZ because all traffic entering ppp+ interfaces would have been redirected to port 3128 on the firewall and there would have been no net->fw ACCEPT rule for that traffic.

Example 10:

Add the tuple (source IP, dest port, dest IP) of an incoming SSH connection to the ipset S:

```
        #ACTION                       SOURCE           DEST           PROTO       DPORT

        ADD(+S:dst,src,dst)           net              fw             tcp         22
```

Example 11:

You wish to limit SSH connections from remote systems to 1/min with a burst of three (to allow for limited retry):

```
        #ACTION     SOURCE          DEST       PROTO       DPORT        SPORT     ORIGDEST         RATE

        SSH(ACCEPT) net             all        -           -            -         -                s:1/min:3
```

Example 12:

Forward port 80 to dmz host $BACKUP if switch 'primary_down' is on.

```
        #ACTION     SOURCE          DEST        PROTO       DPORT        SPORT     ORIGDEST   RATE      USER      MARK    CONNLIMIT     TIME     HEADERS    SWITCH

        DNAT        net             dmz:$BACKUP tcp         80           -         -          -         -         -       -             -        -          primary_down
```

Example 13:

Drop all email from the Anonymous Proxy and Satellite Provider address ranges:

```
        #ACTION                       SOURCE           DEST           PROTO       DPORT

        DROP                          net:^A1,A2       fw             tcp         25
```

Example 14:

You want to generate your own rule involving iptables targets and matches not supported by Shorewall.

```
        #ACTION                       SOURCE           DEST           PROTO       DPORT

        INLINE                        $FW              net ; -p 6 -m mickey-mouse --name test -m set --match-set set1 src -m mickey-mouse --name test2 -j SECCTX --name test3
```

The above will generate the following iptables-restore input:

```
        -A fw2net -p 6 -m mickey-mouse --name test -m set --match-set set1 src -m mickey-mouse --name test2 -j SECCTX --name test3
```

Note that SECCTX must be defined as a builtin action in shorewall-actions[3](5):

```
        #ACTION            OPTIONS

        SECCTX             builtin
```

Example 15:

You want to accept SSH connections to your firewall only from internet IP addresses 2002:ce7c::92b4:1::2 and 2002:ce7c::92b4:1::22

```
        #ACTION  SOURCE DEST            PROTO   DPORT   SPORT   ORIGDEST

        ACCEPT   net:<2002:ce7c::92b4:1::2,2002:ce7c::92b4:1::22> \

                        $FW              tcp     22
```

## FILES
/etc/shorewall/rules

/etc/shorewall6/rules

## SEE ALSO
shorewall-logging(5)[7]

https://shorewall.org/ipsets.html[14]

https://shorewall.org/configuration_file_basics.htm#Pairs[15]

shorewall(8)

## NOTES
1.

shorewall-policy

https://shorewall.org/manpages/shorewall-policy.html

2.

shorewall.conf

https://shorewall.org/manpages/shorewall.conf.html

3.

shorewall-actions

https://shorewall.org/manpages/shorewall-actions.html

4.

shorewall-zones

https://shorewall.org/manpages/shorewall-zones.html

5.

shorewall-nesting

https://shorewall.org/manpages/shorewall-nesting.html

6.

https://shorewall.org/shorewall_logging.html

https://shorewall.org/shorewall_logging.html

7.

shorewall-logging(5)

https://shorewall.org/manpages/shorewall-logging.html

8.

shorewall-interfaces

https://shorewall.org/manpages/shorewall-interfaces.html

9.

shorewall-hosts

https://shorewall.org/manpages/shorewall.hosts.html

10.

shorewall-exclusion

https://shorewall.org/manpages/shorewall-exclusion.html

11.

shorewall-hosts

https://shorewall.org/manpages/shorewall-hosts.html

12.

https://shorewall.org/configuration_file_basics.htm#ICMP

https://shorewall.org/configuration_file_basics.htm#ICMP

13.

https://shorewall.org/PortKnocking.html

https://shorewall.org/PortKnocking.html

14.

https://shorewall.org/ipsets.html

https://shorewall.org/ipsets.html

15.

https://shorewall.org/configuration_file_basics.htm#Pairs

https://shorewall.org/configuration_file_basics.htm#Pairs


shorewall-secmarks

package: shorewall

title: shorewall-secmarks(5)

summary: Shorewall file

text:
# shorewall-secmarks(5)

## NAME
secmarks - Shorewall file

## SYNOPSIS
/etc/shorewall[6]/secmarks

## DESCRIPTION

Important

Unlike rules in the shorewall-rules[1](5) file, evaluation of rules in this file will continue after a match. So the final secmark for each packet will be the one assigned by the LAST rule that matches.

The secmarks file is used to associate an SELinux context with packets. It was added in Shorewall version 4.4.13.

The columns in the file are as follows (where the column name is followed by a different name in parentheses, the different name is used in the alternate specification syntax).

SECMARK - {SAVE|RESTORE|context|?COMMENT comment}

SAVE

If an SELinux context is associated with the packet, the context is saved in the connection. Normally, the remaining columns should be left blank.

RESTORE

If an SELinux context is not currently associated with the packet, then the saved context (if any) is associated with the packet. Normally, the remaining columns should be left blank.

context

An SELinux context.

?COMMENT

The remainder of the line is treated as a comment which is attached to subsequent rules until another ?COMMENT line is found or until the end of the file is reached. To stop adding comments to rules, use a line with only the word ?COMMENT.

CHAIN - {P|I|F|O|T}[:{N|I|U|IU|NI|NU|NIU|NUI:E|ER}]

This column determines the CHAIN where the SELinux context is to be applied: P - PREROUTING

I - INPUT

F - FORWARD

O - OUTPUT

T - POSTROUTING

It may be optionally followed by a colon and an indication of the Netfilter connection state(s) at which the context is to be applied: :N - NEW connection

:I - INVALID connection

:NI - NEW or INVALID connection

:E - ESTABLISHED connection

:ER - ESTABLISHED or RELATED connection

Beginning with Shorewall 4.5.10, the following additional options are available :U - UNTRACKED connection

:IU - INVALID or UNTRACKED connection

:NU - NEW or UNTRACKED connection

:NIU - NEW, INVALID or UNTRACKED connection.

This column was formerly labelled CHAIN:STATE.

SOURCE - {-interface|[interface:]address-or-range[,address-or-range]...}[exclusion]

May be:

1.An interface name - matches traffic entering the firewall on the specified interface. May not be used in classify rules or in rules using the T in the CHAIN column.

2.A comma-separated list of host or network IP addresses or MAC addresses.

3.An interface name followed by a colon (":") followed by a comma-separated list of host or network IP addresses or MAC addresses.

MAC addresses must be prefixed with "~" and use "-" as a separator.

Example: ~00-A0-C9-15-39-78

You may exclude certain hosts from the set already defined through use of an exclusion (see shorewall-exclusion[2](5)).

Addresses may be specified using an ipset name preceded by '+'.

DEST - {-|{interface|[interface:]address-or-range[,address-or-range]...}[exclusion]

May be:

1.An interface name. May not be used in the PREROUTING or INPUT chains. The interface name may be optionally followed by a colon (":") and an IP address list.

2.A comma-separated list of host or network IP addresses. The list may include ip address ranges if your kernel and iptables include iprange support.

You may exclude certain hosts from the set already defined through use of an exclusion (see shorewall-exclusion[2](5)).

Addresses may be specified using an ipset name preceded by '+'.

PROTO - {-|tcp:syn|ipp2p|ipp2p:udp|ipp2p:all|protocol-number|protocol-name|all}[,...]

See shorewall-rules(5)[1] for details. Beginning with Shorewall 4.5.12, this column can accept a comma-separated list of protocols.

DPORT - [-|port-name-number-or-range[,port-name-number-or-range]...]

Optional destination Ports. A comma-separated list of Port names (from services(5)), port numbers or port ranges; if the protocol is icmp, this column is interpreted as the destination icmp-type(s). ICMP types may be specified as a numeric type, a numeric type and code separated by a slash (e.g., 3/4), or a typename. See https://shorewall.org/configuration_file_basics.htm#ICMP[3]. If the protocol is ipp2p, this column is interpreted as an ipp2p option without the leading "--" (example bit for bit-torrent). If no PORT is given, ipp2p is assumed.

This column is ignored if PROTOCOL = all but must be entered if any of the following field is supplied. In that case, it is suggested that this field contain "-"

This column was formerly labelled DEST PORT(S).

SPORT - [-|port-name-number-or-range[,port-name-number-or-range]...]

Optional source port(s). If omitted, any source port is acceptable. Specified as a comma-separated list of port names, port numbers or port ranges. This column was formerly labelled SOURCE PORT(S).

USER - [!][user-name-or-number][:group-name-or-number]

This optional column may only be non-empty if the SOURCE is the firewall itself. When this column is non-empty, the rule applies only if the program generating the output is running under the effective user and/or group specified (or is NOT running under that id if "!" is given).

Examples:

joe

program must be run by joe

:kids

program must be run by a member of the 'kids' group

!:kids

program must not be run by a member of the 'kids' group

MARK - [!]value[/mask][:C]

Defines a test on the existing packet or connection mark. The rule will match only if the test returns true. If you don't want to define a test but need to specify anything in the following columns, place a "-" in this field.

!

Inverts the test (not equal)

value

Value of the packet or connection mark.

mask

A mask to be applied to the mark before testing.

:C

Designates a connection mark. If omitted, the packet mark's value is tested.

## EXAMPLE
Mark the first incoming packet of a connection on the loopback interface and destined for address 127.0.0.1 and tcp port 3306 with context system_u:object_r:mysqld_t:s0 and save that context in the conntrack table. On subsequent input packets in the connection, set the context from the conntrack table.

/etc/shorewall/interfaces:

```
#ZONE      INTERFACE      BROADCAST       OPTIONS
-          lo             -               ignore
```

/etc/shorewall/secmarks:

```
#SECMARK                              CHAIN      SOURCE  DEST       PROTO   DPORT      SPORT       USER      MARK
system_u:object_r:mysqld_packet_t:s0  I:N        lo      127.0.0.1  tcp     3306
SAVE                                  I:N        lo      127.0.0.1  tcp     3306
RESTORE                               I:ER
```

## FILES
/etc/shorewall/secmarks

/etc/shorewall6/secmarks

## SEE ALSO
http://james-morris.livejournal.com/11010.html

https://shorewall.org/configuration_file_basics.htm#Pairs[4]

shorewall(8)

## NOTES
1.

shorewall-rules

https://shorewall.org/manpages/shorewall-rules.html

2.

shorewall-exclusion

https://shorewall.org/manpages/shorewall-exclusion.html

3.

https://shorewall.org/configuration_file_basics.htm#ICMP

https://shorewall.org/configuration_file_basics.htm#ICMP

4.

https://shorewall.org/configuration_file_basics.htm#Pairs

https://shorewall.org/configuration_file_basics.htm#Pairs

branch: sisyphus


shorewall-snat

title: shorewall-snat(5)

text:
# shorewall-snat(5)

## NAME
snat - Shorewall SNAT/Masquerade definition file

## SYNOPSIS
/etc/shorewall[6]/snat

## DESCRIPTION
This file is used to define dynamic NAT (Masquerading) and to define Source NAT (SNAT). It superseded shorewall-masq[1](5) in Shorewall 5.0.14.

Warning

The entries in this file are order-sensitive. The first entry that matches a particular connection will be the one that is used.

Warning

If you have more than one ISP link, adding entries to this file will not force connections to go out through a particular link. You must use entries in shorewall-rtrules[2](5) or PREROUTING entries in shorewall-mangle[3](5) to do that.

Beginning with Shorewall 5.2.6, the snat file supports two different formats:

1.The SPORT (source port) column is omitted. This is the default unless a "?FORMAT 2" compiler directive is included.

2.The SPORT column immediately follows the DPORT column.

The columns in the file are as follows.

ACTION

Defines the type of rule to generate. Beginning with Shorewall 5.1.9, with the exception of NFLOG and ULOG, the action may be followed by a colon (":") and a log level (see shorewall-logging(5)[4]). Choices for ACTION are:

action[+][(parameter,...)][:level]

where action is an action declared in shorewall-actions(5)[5] with the nat option. See https://shorewall.org/Actions.html[6] for further information.

CONTINUE[+]:level

Causes matching packets to be exempted from any following rules in the file.

LOG:level

Added in Shorewall 5.1.9. Simply log the packet and continue with the next rule.

MASQUERADE[+][([lowport[-highport]][random])][:level]

Causes matching outgoing packages to have their source IP address set to the primary IP address of the interface specified in the DEST column. if lowport-highport is given, that port range will be used to assign a source port. If only lowport is given, that port will be assigned, if possible. If option random is used then port mapping will be randomized. MASQUERADE should only be used when the DEST interface has a dynamic IP address. Otherwise, SNAT should be used and should specify the interface's static address.

NFLOG[(nflog-parameters)]

Added in Shorewall 5.1.9. Queues matching packets to a back end logging daemon via a netlink socket then continues to the next rule. See shorewall-logging(5)[4]. The nflog-parameters are a comma-separated list of up to 3 numbers:

•The first number specifies the netlink group (0-65535). If omitted (e.g., NFLOG(,0,10)) then a value of 0 is assumed.

•The second number specifies the maximum number of bytes to copy. If omitted, 0 (no limit) is assumed.

•The third number specifies the number of log messages that should be buffered in the kernel before they are sent to user space. The default is 1.

NFLOG is similar to LOG:NFLOG[(nflog-parameters)], except that the log level is not changed when this ACTION is used in an action or macro body and the invocation of that action or macro specifies a log level.

SNAT[+]([address-or-address-range][:lowport[-highport]][:random][:persistent]|detect)[:level]

If you specify an address here, matching packets will have their source address set to that address. If ADD_SNAT_ALIASES is set to Yes or yes in shorewall.conf[7](5) then Shorewall will automatically add this address to the INTERFACE named in the first column (IPv4 only). You may also specify a range of up to 256 IP addresses if you want the SNAT address to be assigned from that range in a round-robin fashion by connection. The range is specified by first.ip.in.range-last.ip.in.range. You may follow the port range with :random in which case assignment of ports from the list will be random. random may also be specified by itself in this column in which case random local port assignments are made for the outgoing connections.

Example: 206.124.146.177-206.124.146.180

You may follow the port range (or :random) with :persistent. This is only useful when an address range is specified and causes a client to be given the same source/destination IP pair.

You may also use the special value detect which causes Shorewall to determine the IP addresses configured on the interface named in the DEST column and substitute them in this column.

DNS Names names are not allowed.

Normally, Netfilter will attempt to retain the source port number. You may cause netfilter to remap the source port by following an address or range (if any) by ":" and a port range with the format lowport-highport. If this is done, you must specify "tcp", "udp", "dccp" or "stcp" in the PROTO column.

Examples:

```
        192.0.2.4:5000-6000

        :4000-5000
```

You may also specify a single port number, which will be assigned to the outgoing connection, if possible.

ULOG[(ulog-parameters)]

IPv4 only. Added in Shorewall 5.1.9. Queues matching packets to a back end logging daemon via a netlink socket then continues to the next rule. See shorewall-logging(5)[4]. Similar to LOG:ULOG[(ulog-parameters)], except that the log level is not changed when this ACTION is used in an action or macro body and the invocation of that action or macro specifies a log level.

Normally Masq/SNAT rules are evaluated after those for one-to-one NAT (defined in shorewall-nat[8](5)). If you want the rule to be applied before one-to-one NAT rules, follow the action name with "+": This feature should only be required if you need to insert rules in this file that preempt entries in shorewall-nat[8](5).

SOURCE (Optional) - [interface|address[,address...][exclusion]]

Set of hosts that you wish to masquerade. You can specify this as an address (net or host) or as an interface. Unless you want to perform SNAT in the INPUT chain (see DEST below), if you give the name of an interface (deprecated), the interface must be up before you start the firewall and the Shorewall rules compiler will warn you of that fact. (Shorewall will use your main routing table to determine the appropriate addresses to masquerade). The preferred way to specify the SOURCE is to supply one or more host or network addresses separated by comma. You may use ipset names preceded by a plus sign (+) to specify a set of hosts.

DEST - {interface[:digit][,interface[:digit]]...|$FW}[:[dest-address[,dest-address]...[exclusion]]

Outgoing interfaces and destination networks. Multiple interfaces may be listed when the ACTION is MASQUERADE, but this is usually just your internet interface. If ADD_SNAT_ALIASES=Yes in shorewall.conf[7](5), you may add ":" and a digit to indicate that you want the alias added with that name (e.g., eth0:0). This will allow the alias to be displayed with ifconfig. That is the only use for the alias name; it may not appear in any other place in your Shorewall configuration. Beginning with Shorewall 5.1.12, SNAT may be performed in the nat table's INPUT chain by specifying $FW rather than one or more interfaces.

Each interface must match an entry in shorewall-interfaces[9](5). Shorewall allows loose matches to wildcard entries in shorewall-interfaces[9](5). For example, ppp0 in this file will match a shorewall-interfaces[9](5) entry that defines ppp+.

Where more that one internet provider share a single interface[10], the provider is specified by including the provider name or number in parentheses:

```
        eth0(Avvanta)
```

In that case, you will want to specify the interface's address for that provider as the SNAT parameter.

The interface may be qualified by adding the character ":" followed by a comma-separated list of destination host or subnet addresses to indicate that you only want to change the source IP address for packets being sent to those particular destinations. Exclusion is allowed (see shorewall-exclusion[11](5)) as are ipset names preceded by a plus sign '+';

If you wish to inhibit the action of ADD_SNAT_ALIASES for this entry then include the ":" but omit the digit:

```
        eth0(Avvanta):

        eth2::192.0.2.32/27
```

Comments may be attached to Netfilter rules generated from entries in this file through the use of ?COMMENT lines. These lines begin with ?COMMENT; the remainder of the line is treated as a comment which is attached to subsequent rules until another ?COMMENT line is found or until the end of the file is reached. To stop adding comments to rules, use a line containing only ?COMMENT.

PROTO (Optional) - {-|[!]{protocol-name|protocol-number}[,...]|+ipset}

If you wish to restrict this entry to a particular protocol then enter the protocol name (from protocols(5)) or number here. See shorewall-rules(5)[12] for details. Beginning with Shorewall 4.5.12, this column can accept a comma-separated list of protocols.

Beginning with Shorewall 4.6.0, an ipset name can be specified in this column. This is intended to be used with bitmap:port ipsets.

{PORT|DPORT} (Optional) - {-|[!]port-name-or-number[,port-name-or-number]...|+ipset}

The column was renamed to DPORT in Shorewall 5.2.6. Beginning with that release, both PORT and DPORT are accepted in the alternative input format, If the PROTO column specifies TCP (6), UDP (17), DCCP (33), SCTP (132) or UDPLITE (136) then you may list one or more port numbers (or names from services(5)) or port ranges separated by commas.

Port ranges are of the form lowport:highport.

Beginning with Shorewall 4.6.0, an ipset name can be specified in this column. This is intended to be used with bitmap:port ipsets.

SPORT {-|[!]port-name-or-number[,port-name-or-number]...|+ipset}

FORMAT 2 only. If the PROTO column specifies TCP (6), UDP (17), DCCP (33), SCTP (132) or UDPLITE (136) then you may list one or more port numbers (or names from services(5)) or port ranges separated by commas.

Port ranges are of the form lowport:highport.

An ipset name can be specified in this column. This is intended to be used with bitmap:port ipsets.

IPSEC (Optional) - [option[,option]...]

If you specify a value other than "-" in this column, you must be running kernel 2.6 and your kernel and iptables must include policy match support. Comma-separated list of options from the following. Only packets that will be encrypted via an SA that matches these options will have their source address changed.

reqid=number

where number is specified using setkey(8) using the 'unique:number option for the SPD level.

spi=<number>

where number is the SPI of the SA used to encrypt/decrypt packets.

proto=ah|esp|ipcomp

IPSEC Encapsulation Protocol

mss=number

sets the MSS field in TCP packets

mode=transport|tunnel

IPSEC mode

tunnel-src=address[/mask]

only available with mode=tunnel

tunnel-dst=address[/mask]

only available with mode=tunnel

strict

Means that packets must match all rules.

next

Separates rules; can only be used with strict

yes

When used by itself, causes all traffic that will be encrypted/encapsulated to match the rule.

MARK - [!]value[/mask][:C]

Defines a test on the existing packet or connection mark. The rule will match only if the test returns true. If you don't want to define a test but need to specify anything in the following columns, place a "-" in this field.

!

Inverts the test (not equal)

value

Value of the packet or connection mark.

mask

A mask to be applied to the mark before testing.

:C

Designates a connection mark. If omitted, the packet mark's value is tested.

USER (Optional) - [!][user-name-or-number][:group-name-or-number][+program-name]

This column was formerly labelled USER/GROUP. Only locally-generated connections will match if this column is non-empty.

When this column is non-empty, the rule matches only if the program generating the output is running under the effective user and/or group specified (or is NOT running under that id if "!" is given).

Examples:

joe

program must be run by joe

:kids

program must be run by a member of the 'kids' group

!:kids

program must not be run by a member of the 'kids' group

+upnpd

\#program named upnpd

Important

The ability to specify a program name was removed from Netfilter in kernel version 2.6.14.

SWITCH - [!]switch-name[={0|1}]

Added in Shorewall 4.5.1 and allows enabling and disabling the rule without requiring shorewall restart. The rule is enabled if the value stored in /proc/net/nf_condition/switch-name is 1. The rule is disabled if that file contains 0 (the default). If '!' is supplied, the test is inverted such that the rule is enabled if the file contains 0.

Within the switch-name, '@0' and '@{0}' are replaced by the name of the chain to which the rule is a added. The switch-name (after '@...' expansion) must begin with a letter and be composed of letters, decimal digits, underscores or hyphens. Switch names must be 30 characters or less in length.

Switches are normally off. To turn a switch on:

echo 1 >

/proc/net/nf_condition/switch-name

To turn it off again: echo 0 >

/proc/net/nf_condition/switch-name

Switch settings are retained over shorewall restart. Beginning with Shorewall 4.5.10, when the switch-name is followed by =0 or =1, then the switch is initialized to off or on respectively by the start command. Other commands do not affect the switch setting.

ORIGDEST - [-|address[,address]...[exclusion]|exclusion]

(Optional) Added in Shorewall 4.5.6. This column may be included and may contain one or more addresses (host or network) separated by commas. Address ranges are not allowed. When this column is supplied, rules are generated that require that the original destination address matches one of the listed addresses. It is useful for specifying that SNAT should occur only for connections that were acted on by a DNAT when they entered the firewall. This column was formerly labelled ORIGINAL DEST.

PROBABILITY - [probability]

Added in Shorewall 5.0.0. When non-empty, requires the Statistics Match capability in your kernel and ip6tables and causes the rule to match randomly but with the given probability. The probability is a number 0 < probability <= 1 and may be expressed at up to 8 decimal points of precision.

## EXAMPLES
IPv4 Example 1:

You have a simple masquerading setup where eth0 connects to a DSL or cable modem and eth1 connects to your local network with subnet 192.168.0.0/24. Your entry in the file will be:

```
        #ACTION    SOURCE              DEST

        MASQUERADE 192.168.0.0/24      eth0
```

IPv4 Example 2:

You add a router to your local network to connect subnet 192.168.1.0/24 which you also want to masquerade. You then add a second entry for eth0 to this file:

```
        #ACTION    SOURCE              DEST

        MASQUERADE 192.168.0.0/24      eth0

        MASQUERADE 192.168.1.0/24      eth0
```

IPv4 Example 3:

You want all outgoing traffic from 192.168.1.0/24 through eth0 to use source address 206.124.146.176 which is NOT the primary address of eth0. You want 206.124.146.176 to be added to eth0 with name eth0:0.

```
        #ACTION                 SOURCE          DEST

        SNAT(206.124.146.176)   192.168.1.0/24  eth0:0
```

IPv4 Example 4:

You want all outgoing SMTP traffic entering the firewall from 172.20.1.0/29 to be sent from eth0 with source IP address 206.124.146.177. You want all other outgoing traffic from 172.20.1.0/29 to be sent from eth0 with source IP address 206.124.146.176.

```
        #INTERFACE   SOURCE           ADDRESS         PROTO   DPORT

        eth0         172.20.1.0/29    206.124.146.177 tcp     smtp

        eth0         172.20.1.0/29    206.124.146.176
```

```
        #ACTION                 SOURCE          DEST        PROTO     PORT

        SNAT(206.124.146.177)   172.20.1.0/29   eth0        tcp       smtp

        SNAT(206.124.146.176)   172.20.1.0/29   eth0
```

Warning

The order of the above two rules is significant!

IPv4 Example 5:

Connections leaving on eth0 and destined to any host defined in the ipset myset should have the source IP address changed to 206.124.146.177.

```
        #ACTION                 SOURCE          DEST

        SNAT(206.124.146.177)   -               eth0:+myset[dst]
```

IPv4 Example 6:

SNAT outgoing connections on eth0 from 192.168.1.0/24 randomly to addresses 1.1.1.1, 1.1.1.3, and 1.1.1.9 (Shorewall 5.0.0 and later).

```
/etc/shorewall/snat:

       #ACTION                 SOURCE          DEST

       SNAT(1.1.1.1)           192.168.1.0/24  eth0  { probability=0.33 }

       SNAT(1.1.1.3)           192.168.1.0/24  eth0  { probability=0.50 }

       SNAT(1.1.1.9)           192.168.1.0/24  eth0
```

IPv6 Example 1:

You have a simple 'masquerading' setup where eth0 connects to a DSL or cable modem and eth1 connects to your local network with subnet 2001:470:b:787::0/64 Your entry in the file will be:

```
        #ACTION      SOURCE                  DEST

        MASQUERADE   2001:470:b:787::0/64    eth0
```

IPv6 Example 2:

Your sit1 interface has two public IP addresses: 2001:470:a:227::1 and 2001:470:b:227::1. You want to use the iptables statistics match to masquerade outgoing connections evenly between these two addresses.

```
/etc/shorewall/snat:

       #ACTION                      SOURCE     DEST

       SNAT(2001:470:a:227::1)      ::/0       sit1              { probability=0.50 }

       SNAT(2001:470:a:227::2)      ::/0       sit
```

## FILES
/etc/shorewall/snat

/etc/shorewall6/snat

## SEE ALSO
https://shorewall.org/configuration_file_basics.htm#Pairs[13]

shorewall(8)

## NOTES
1.

shorewall-masq

https://shorewall.org/manpages/shorewall-masq.html

2.

shorewall-rtrules

https://shorewall.org/manpages/shorewall-rtrules.html

3.

shorewall-mangle

https://shorewall.org/manpages/shorewall-mangle.html

4.

shorewall-logging(5)

https://shorewall.org/manpages/shorewall-logging.html

5.

shorewall-actions(5)

https://shorewall.org/manpages/shorewall-actions.html

6.

https://shorewall.org/Actions.html

https://shorewall.org/Actions.html

7.

shorewall.conf

https://shorewall.org/manpages/shorewall.conf.html

8.

shorewall-nat

https://shorewall.org/manpages/shorewall-nat.html

9.

shorewall-interfaces

https://shorewall.org/manpages/shorewall-interfaces.html

10.

more that one internet provider share a single interface

https://shorewall.org/4.4/MultiISP.html#Shared

11.

shorewall-exclusion

https://shorewall.org/manpages/shorewall-exclusion.html

12.

shorewall-rules(5)

https://shorewall.org/manpages/shorewall-rules.html

13.

https://shorewall.org/configuration_file_basics.htm#Pairs

https://shorewall.org/configuration_file_basics.htm#Pairs


shorewall-stoppedrules

title: shorewall-stoppedrules(5)

summary: The Shorewall file that governs what traffic flows through the firewall while it is in the \*(Aqstopped\*(Aq state.

text:
# shorewall-stoppedrules(5)

## NAME
stoppedrules - The Shorewall file that governs what traffic flows through the firewall while it is in the 'stopped' state.

## SYNOPSIS
/etc/shorewall[6]/stoppedrules

## DESCRIPTION
This file is used to define the hosts that are accessible when the firewall is stopped or is being stopped.

Warning

Changes to this file do not take effect until after the next shorewall start, shorewall reload, shorewall restart, or shorewall compile command.

The columns in the file are as follows (where the column name is followed by a different name in parentheses, the different name is used in the alternate specification syntax).

ACTION - ACCEPT|NOTRACK|DROP

Determines the disposition of the packet. ACCEPT means that the packet will be accepted.

NOTRACK indicates that no conntrack entry should be created for the packet. NOTRACK does not imply ACCEPT.

DROP was added in Shorewall 4.6.0 and causes the packet to be dropped in the raw table's PREROUTING chain.

SOURCE - [-|[$FW|interface]|[{$FW|interface}[:address[,address]...]]|[address[,address]...]

$FW matches packets originating on the firewall itself, while interface specifies packets arriving on the named interface. This column may also include a comma-separated list of IP/subnet addresses. If your kernel and iptables include iprange match support, IP address ranges are also allowed. Ipsets and exclusion are also supported. When $FW or interface are specified, the list must be preceded by a colon (":").

If left empty or supplied as "-", 0.0.0.0/0 is assumed.

DEST - [-|[$FW|interface]|[{$FW|interface}[:address[,address]...]]|[address[,address]...]

$FW matches packets addressed the firewall itself, while interface specifies packets arriving on the named interface. Neither may be specified if the target is NOTRACK or DROP. This column may also include a comma-separated list of IP/subnet addresses. If your kernel and iptables include iprange match support, IP address ranges are also allowed. Ipsets and exclusion are also supported. When $FW or interface are specified, the list must be preceded by a colon (":").

If left empty or supplied as "-", 0.0.0.0/0 is assumed.

PROTO (Optional) – protocol-name-or-number[,...]

Protocol. Beginning with Shorewall 4.5.12, this column can accept a comma-separated list of protocols.

DPORT – service-name/port-number-list

Optional. A comma-separated list of port numbers and/or service names from /etc/services. May also include port ranges of the form low-port:high-port if your kernel and iptables include port range support. This column was formerly labelled DEST PORT(S).

SPORT – service-name/port-number-list

Optional. A comma-separated list of port numbers and/or service names from /etc/services. May also include port ranges of the form low-port:high-port if your kernel and iptables include port range support. Beginning with Shorewall 4.5.15, you may place '=' in this column, provided that the DPORT column is non-empty. This causes the rule to match when either the source port or the destination port in a packet matches one of the ports specified in DEST PORTS(S). Use of '=' requires multi-port match in your iptables and kernel.

This column was formerly labelled SOURCE PORT(S).

## FILES
/etc/shorewall/stoppedrules

/etc/shorewall6/stoppedrules

## SEE ALSO
https://shorewall.org/starting_and_stopping_shorewall.htm[1]

https://shorewall.org/configuration_file_basics.htm#Pairs[2]

shorewall(8)

## NOTES
1.

https://shorewall.org/starting_and_stopping_shorewall.htm

https://shorewall.org/starting_and_stopping_shorewall.htm

2.

https://shorewall.org/configuration_file_basics.htm#Pairs

https://shorewall.org/configuration_file_basics.htm#Pairs


shorewall-tcclasses

title: shorewall-tcclasses(5)

text:
# shorewall-tcclasses(5)

## NAME
tcclasses - Shorewall file to define HTB and HFSC classes

## SYNOPSIS
/etc/shorewall[6]/tcclasses

## DESCRIPTION
A note on the rate/bandwidth definitions used in this file:

•don't use a space between the integer value and the unit: 30kbit is valid while 30 kbit is NOT.

•you can use one of the following units: kpbs

Kilobytes per second.

mbps

Megabytes per second.

kbit

Kilobits per second.

mbit

Megabits per second.

bps or number

Bytes per second.

•if you want the values to be calculated for you depending on the output bandwidth setting defined for an interface in tcdevices, you can use expressions like the following: full/3

causes the bandwidth to be calculated as 1/3 of the full outgoing speed that is defined.

full*9/10

will set this bandwidth to 9/10 of the full bandwidth

Note that in a sub-class (a class that has a specified parent class), full refers to the RATE or CEIL of the parent class rather than to the OUT-BANDWIDTH of the device.

DO NOT add a unit to the rate if it is calculated !

The columns in the file are as follows.

INTERFACE - interface[[:parent]:class]

Name of interface. You may specify the interface number rather than the interface name. If the classify option is given for the interface in shorewall-tcdevices[1](5), then you must also specify an interface class (an integer that must be unique within classes associated with this interface). If the classify option is not given, you may still specify a class or you may have Shorewall generate a class number from the MARK value. Interface numbers and class numbers are always assumed to be specified in hex and class number 1 is reserved as the root class of the queuing discipline.

You may NOT specify wildcards here, e.g. if you have multiple ppp interfaces, you need to put them all in here!

Please note that you can only use interface names in here that have a bandwidth defined in the shorewall-tcdevices[1](5) file.

Normally, all classes defined here are sub-classes of a root class that is implicitly defined from the entry in shorewall-tcdevices[1](5). You can establish a class hierarchy by specifying a parent class -- the number of a class that you have previously defined. The sub-class may borrow unused bandwidth from its parent.

MARK - {-|value[:priority]}

The mark value which is an integer in the range 1-255. You set mark values in the shorewall-mangle[2](5) file, marking the traffic you want to fit in the classes defined in here. You can use the same marks for different interfaces. The priority, if specified, is an integer in the range 1-65535 and determines the relative order in which the tc mark classification filter for this class is to be applied to packets being sent on the interface. Filters are applied in ascending numerical order. If not supplied, the value is derived from the class priority (PRIORITY column value below): (class priority << 8) | 20.

RATE - {-|rate[:dmax[:umax]]}

The minimum bandwidth this class should get, when the traffic load rises. If the sum of the rates in this column exceeds the INTERFACE's OUT-BANDWIDTH, then the OUT-BANDWIDTH limit may not be honored. Similarly, if the sum of the rates of sub-classes of a class exceed the CEIL of the parent class, things don't work well. When using the HFSC queuing discipline, this column specify the real-time (RT) service curve. leaf classes may specify dmax, the maximum delay in milliseconds that the first queued packet for this class should experience. May be expressed as an integer, optionally followed by 'ms' with no intervening white-space (e.g., 10ms).

HFSC leaf classes may also specify umax, the largest packet expected in this class. May be expressed as an integer. The unit of measure is bytes and the integer may be optionally followed by 'b' with no intervening white-space (e.g., 800b). umax may only be given if dmax is also given.

Beginning with Shorewall 4.5.6, HFSC classes may omit this column (e.g, '-' in the column), provided that an lsrate is specified (see CEIL below). These rates are used to arbitrate between classes of the same priority.

CEIL - [lsrate:]rate

The maximum bandwidth this class is allowed to use when the link is idle. Useful if you have traffic which can get full speed when more needed services (e.g. ssh) are not used. You can use the value full in here for setting the maximum bandwidth to the RATE of the parent class, or the OUT-BANDWIDTH of the device if there is no parent class.

Beginning with Shorewall 4.5.6, you can also specify an lsrate (link sharing rate).

PRIORITY - priority

For HTB: The priority in which classes will be serviced by the packet shaping scheduler and also the priority in which bandwidth in excess of the rate will be given to each class. Higher priority classes will experience less delay since they are serviced first. Priority values are serviced in ascending order (e.g. 0 is higher priority than 1).

Classes may be set to the same priority, in which case they will be serviced as equals. For both HTB and HFSC, the priority is used to calculate the priority of following Shorewall-generated classification filters that refer to the class:

•Packet MARK

•tcp-ack and the tos options (see below)

The rules for classes with lower numeric priorities will appear before those with higher numeric priorities.

Beginning with Shorewall 4.5.8, the PRIORITY may be omitted from an HFSC class if you do not use the MARK column or the tcp-ack or tos options. If you use any of those features and omit the PRIORITY, then you must specify a priority along with the MARK or option.

OPTIONS (Optional) - [option[,option]...]

A comma-separated list of options including the following: default

This is the default class for that interface where all traffic should go, that is not classified otherwise.

Note

You must define default for exactly one class per interface.

tos=0xvalue[/0xmask][:priority] (mask defaults to 0xff)

This lets you define a classifier for the given value/mask combination of the IP packet's TOS/Precedence/DiffSrv octet (aka the TOS byte). Beginning with Shorewall 4.5.8, the value/mask may be followed by a colon (":") and a priority. This priority determines the order in which filter rules are processed during packet classification. If not specified, the value (class priority << 8) | 15) is used.

tos-tosname[:priority]

Aliases for the following TOS octet value and mask encodings. TOS encodings of the "TOS byte" have been deprecated in favor of diffserve classes, but programs like ssh, rlogin, and ftp still use them. Beginning with Shorewall 4.5.8, the tos-name may be followed by a colon (":") and a priority. This priority determines the order in which filter rules are processed during packet classification. If not specified, the value (class priority << 8) | 15) is used.

```
        tos-minimize-delay       0x10/0x10

        tos-maximize-throughput  0x08/0x08

        tos-maximize-reliability 0x04/0x04

        tos-minimize-cost        0x02/0x02

        tos-normal-service       0x00/0x1e
```

Note

Each of these options is only valid for ONE class per interface.

tcp-ack[:priority]

If defined, causes a tc filter to be created that puts all tcp ack packets on that interface that have a size of <=64 Bytes to go in this class. This is useful for speeding up downloads. Please note that the size of the ack packets is limited to 64 bytes because we want only packets WITHOUT payload to match. Beginning with Shorewall 4.5.8, the tcp-ack may be followed by a colon (":") and a priority. This priority determines the order in which filter rules are processed during packet classification. If not specified, the value (class priority << 8) | 10) is used.

Note

This option is only valid for ONE class per interface.

occurs=number

Typically used with an IPMARK entry in tcrules. Causes the rule to be replicated for a total of number rules. Each rule has a successively class number and mark value. When 'occurs' is used:

•The associated device may not have the 'classify' option.

•The class may not be the default class.

•The class may not have any 'tos=' options (including 'tcp-ack').

•The class should not specify a MARK value. If one is specified, it will be ignored with a warning message.

The 'RATE' and 'CEIL' parameters apply to each instance of the class. So the total RATE represented by an entry with 'occurs' will be the listed RATE multiplied by number. For additional information, see shorewall-tcrules[3] (5).

flow=keys

Shorewall attaches an SFQ queuing discipline to each leaf HTB class. SFQ ensures that each flow gets equal access to the interface. The default definition of a flow corresponds roughly to a Netfilter connection. So if one internal system is running BitTorrent, for example, it can have lots of 'flows' and can thus take up a larger share of the bandwidth than a system having only a single active connection. The flow classifier (module cls_flow) works around this by letting you define what a 'flow' is. The classifier must be used carefully or it can block off all traffic on an interface! The flow option can be specified for an HTB leaf class (one that has no sub-classes). We recommend that you use the following: Shaping internet-bound traffic:

flow=nfct-src

Shaping traffic bound for your local net:

flow=dst

These will cause a 'flow' to consists of the traffic to/from each internal system. When more than one key is give, they must be enclosed in parenthesis and separated by commas.

To see a list of the possible flow keys, run this command: tc filter add flow help Those that begin with "nfct-" are Netfilter connection tracking fields. As shown above, we recommend flow=nfct-src; that means that we want to use the source IP address before NAT as the key.

pfifo

When specified for a leaf class, the pfifo queuing discipline is applied to the class rather than the sfq queuing discipline.

limit=number

Added in Shorewall 4.4.3. When specified for a leaf class, determines the maximum number of packets that may be queued within the class. The number must be > 2 and <=128. If not specified, the value 127 is assumed.

red=(redoption=value, ...)

Added in Shorewall 4.5.6. When specified on a leaf class, causes the class to use the RED (Random Early Detection) queuing discipline rather than SFQ. See tc-red (8) for additional information. Allowable redoptions are:

min min

Average queue size at which marking becomes a possibility.

max max

At this average queue size, the marking probability is maximal. Must be at least twice min to prevent synchronous retransmits, higher for low min.

probability probability

Maximum probability for marking, specified as a floating point number from 0.0 to 1.0. Suggested values are 0.01 or 0.02 (1 or 2%, respectively).

limit limit

Hard limit on the real (not average) queue size in bytes. Further packets are dropped. Should be set higher than max+burst. It is advised to set this a few times higher than max. Shorewall requires that limit be at least twice min.

burst burst

Used for determining how fast the average queue size is influenced by the real queue size. Larger values make the calculation more sluggish, allowing longer bursts of traffic before marking starts. Real life experiments support the following guide‐line: (min+min+max)/(3*avpkt).

avpkt avpkt

Optional. Specified in bytes. Used with burst to determine the time constant for average queue size calculations. 1000 is a good value and is the Shorewall default.

bandwidth bandwidth

Optional. This rate is used for calculating the average queue size after some idle time. Should be set to the bandwidth of your interface. Does not mean that RED will shape for you!

ecn

RED can either 'mark' or 'drop'. Explicit Congestion Notification allows RED to notify remote hosts that their rate exceeds the amount of bandwidth available. Non-ECN capable hosts can only be notified by dropping a packet. If this parameter is specified, packets which indicate that their hosts honor ECN will only be marked and not dropped, unless the queue size hits limit bytes. Recommended.

fq_codel[=(codeloption=value, ...)]

Added in Shorewall 4.5.12. When specified for a leaf class, causes the class to use the FQ_CODEL (Fair-queuing Controlled Delay) queuing discipline rather than SFQ. See tc-fq_codel (8) for additional information. Allowable codeloptions are:

limit

hard limit on the real queue size. When this limit is reached, incoming packets are dropped. If the value is lowered, packets are dropped so that the new limit is met. Default is 1000 packets.

flows

is the number of flows into which the incoming packets are classified. Due to the stochastic nature of hashing, multiple flows may end up being hashed into the same slot. Newer flows have priority over older ones. This parameter can be set only at load time since memory has to be allocated for the hash table. Default value is 1024.

target

is the acceptable minimum standing/persistent queue delay. This minimum delay is identified by tracking the local minimum queue delay that packets experience. Default and recommended value is 5ms.

interval

is used to ensure that the measured minimum delay does not become too stale. The minimum delay must be experienced in the last epoch of length interval. It should be set on the order of the worst-case RTT through the bottleneck to give endpoints sufficient time to react. Default value is 100ms.

quantum

is the number of bytes used as 'deficit' in the fair queuing algorithm. Default is set to 1514 bytes which corresponds to the Ethernet MTU plus the hardware header length of 14 bytes.

ecn | noecn

can be used to mark packets instead of dropping them. If ecn has been enabled, noecn can be used to turn it off and vice-versa. By default, ecn is enabled.

## EXAMPLES
Example 1:

Suppose you are using PPP over Ethernet (DSL) and ppp0 is the interface for this. You have 4 classes here, the first you can use for voice over IP traffic, the second interactive traffic (e.g. ssh/telnet but not scp), the third will be for all unclassified traffic, and the forth is for low priority traffic (e.g. peer-to-peer). The voice traffic in the first class will be guaranteed a minimum of 100kbps and always be serviced first (because of the low priority number, giving less delay) and will be granted excess bandwidth (up to 180kbps, the class ceiling) first, before any other traffic. A single VoIP stream, depending upon codecs, after encapsulation, can take up to 80kbps on a PPPoE/DSL link, so we pad a little bit just in case. (TOS byte values 0xb8 and 0x68 are DiffServ classes EF and AFF3-1 respectively and are often used by VOIP devices).

Interactive traffic (tos-minimum-delay) and TCP acks (and ICMP echo traffic if you use the example in tcrules) and any packet with a mark of 2 will be guaranteed 1/4 of the link bandwidth, and may extend up to full speed of the link.

Unclassified traffic and packets marked as 3 will be guaranteed 1/4th of the link bandwidth, and may extend to the full speed of the link.

Packets marked with 4 will be treated as low priority packets. (The tcrules example marks p2p traffic as such.) If the link is congested, they're only guaranteed 1/8th of the speed, and even if the link is empty, can only expand to 80% of link bandwidth just as a precaution in case there are upstream queues we didn't account for. This is the last class to get additional bandwidth and the last to get serviced by the scheduler because of the low priority.

```
        #INTERFACE  MARK  RATE    CEIL      PRIORITY    OPTIONS

        ppp0        1     100kbit 180kbit   1           tos=0x68/0xfc,tos=0xb8/0xfc

        ppp0        2     full/4  full      2           tcp-ack,tos-minimize-delay

        ppp0        3     full/4  full      3           default

        ppp0        4     full/8  full*8/10 4
```

## FILES
/etc/shorewall/tcclasses

/etc/shorewall6/tcclasses

## SEE ALSO
https://shorewall.org/traffic_shaping.htm[4]

https://shorewall.org/configuration_file_basics.htm#Pairs[5]

tc-hfsc(7)

tc-red(8)

shorewall(8)

## NOTES
1.

shorewall-tcdevices

https://shorewall.org/manpages/shorewall-tcdevices.html

2.

shorewall-mangle

https://shorewall.org/manpages/shorewall-mangle.html

3.

shorewall-tcrules

https://shorewall.org/manpages/shorewall-tcrules.html

4.

https://shorewall.org/traffic_shaping.htm

https://shorewall.org/traffic_shaping.htm

5.

https://shorewall.org/configuration_file_basics.htm#Pairs

https://shorewall.org/configuration_file_basics.htm#Pairs