Provided by: shorewall_5.1.12.2-1_all bug

NAME

       conntrack - shorewall conntrack file

SYNOPSIS

       /etc/shorewall[6]/conntrack

DESCRIPTION

       The original intent of the notrack file was to exempt certain traffic from Netfilter
       connection tracking. Traffic matching entries in the file were not to be tracked.

       The role of the file was expanded in Shorewall 4.4.27 to include all rules that can be
       added in the Netfilter raw table. In 4.5.7, the file's name was changed to conntrack.

       The file supports three different column layouts: FORMAT 1, FORMAT 2, and FORMAT 3 with
       FORMAT 1 being the default. The three differ as follows:

       •   in FORMAT 2 and 3, there is an additional leading ACTION column.

       •   in FORMAT 3, the SOURCE column accepts no zone name; rather the ACTION column allows a
           SUFFIX that determines the chain(s) that the generated rule will be added to.

       When an entry in the following form is encountered, the format of the following entries
       are assumed to be of the specified format.
           ?FORMAT
                 format

       where format is either 1,2 or 3.

       Format 3 was introduced in Shorewall 4.5.10.

       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.

       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 -
       {NOTRACK|CT:helper:name[(arg=val[,...])|CT:ctevents:event[,...]|CT:expevents:new|CT:notrack|DROP|LOG|ULOG(ulog-parameters):NFLOG(nflog-parameters)|IP[6]TABLES(target)}[log-level[:log-tag]][:chain-designator]
           This column is only present when FORMAT >= 2. Values other than NOTRACK or DROP
           require CT Targetsupport in your iptables and kernel.

           •   NOTRACK or CT:notrack

               Disables connection tracking for this packet. If a log-level is specified, the
               packet will also be logged at that level.

           •   CT:helper:name

               Attach the helper identified by the name to this connection. This is more flexible
               than loading the conntrack helper with preset ports. If a log-level is specified,
               the packet will also be logged at that level. Beginning with Shorewall 4.6.10, the
               helper name is optional

               At this writing, the available helpers are:

               amanda
                   Requires that the amanda netfilter helper is present.

               ftp
                   Requires that the FTP netfilter helper is present.

               irc
                   Requires that the IRC netfilter helper is present.

               netbios-ns
                   Requires that the netbios_ns (sic) helper is present.

               RAS and Q.931
                   These require that the H323 netfilter helper is present.

               pptp
                   Requires that the pptp netfilter helper is present.

               sane
                   Requires that the SANE netfilter helper is present.

               sip
                   Requires that the SIP netfilter helper is present.

               snmp
                   Requires that the SNMP netfilter helper is present.

               tftp
                   Requires that the TFTP netfilter helper is present.

               May be followed by an option list of arg=val pairs in parentheses:

               •   ctevents=event[,...]

                   Only generate the specified conntrack events for this connection. Possible
                   event types are: new, related, destroy, reply, assured, protoinfo, helper,
                   mark (this is connection mark, not packet mark), natseqinfo, and secmark. If
                   more than one event is listed, the event list must be enclosed in parentheses
                   (e.g., ctevents=(new,related)).

               •   expevents=new

                   Only generate a new expectation events for this connection.

           •   ctevents:event[,...]

               Added in Shorewall 4.6.10. Only generate the specified conntrack events for this
               connection. Possible event types are: new, related, destroy, reply, assured,
               protoinfo, helper, mark (this is connection mark, not packet mark), natseqinfo,
               and secmark.

           •   expevents=new

               Added in Shorewall 4.6.10. Only generate new expectation events for this
               connection.

           •   DROP

               Added in Shorewall 4.5.10. Silently discard the packet. If a log-level is
               specified, the packet will also be logged at that level.

           •   IP6TABLES(target)

               IPv6 only.

               Added in Shorewall 4.6.0. Allows you to specify any iptables target with target
               options (e.g., "IP6TABLES(AUDIT --type drop)"). If the target is not one
               recognized by Shorewall, the following error message will be issued:
                   ERROR: Unknown target
                                   (target)
               This error message may be eliminated by adding target as a builtin action in
               shorewall-actions[1](5).

           •   IPTABLES(target)

               IPv4 only.

               Added in Shorewall 4.6.0. Allows you to specify any iptables target with target
               options (e.g., "IPTABLES(AUDIT --type drop)"). If the target is not one recognized
               by Shorewall, the following error message will be issued:
                   ERROR: Unknown target
                                   (target)
               This error message may be eliminated by adding target as a builtin action in
               shorewall-actions[1](5).

           •   LOG

               Added in Shoreawll 4.6.0. Logs the packet using the specified log-level and
               log-tag (if any). If no log-level is specified, then 'info' is assumed.

           •   NFLOG

               Added in Shoreawll 4.6.0. Queues the packet to a backend logging daemon using the
               NFLOG netfilter target with the specified nflog-parameters.

           •   ULOG

               IPv4 only. Added in Shoreawll 4.6.0. Queues the packet to a backend logging daemon
               using the ULOG netfilter target with the specified ulog-parameters.

           When FORMAT = 1, this column is not present and the rule is processed as if NOTRACK
           had been entered in this column.

           Beginning with Shorewall 4.5.10, when FORMAT = 3, this column can end with a colon
           followed by a chain-designator. The chain-designator can be one of the following:

           P
               The rule is added to the raw table PREROUTING chain. This is the default if no
               chain-designator is present.

           O
               The rule is added to the raw table OUTPUT chain.

           PO or OP
               The rule is added to the raw table PREROUTING and OUTPUT chains.

       SOURCE (formats 1 and 2) – {zone[:interface][:address-list]}
           where zone is the name of a zone, interface is an interface to that zone, and
           address-list is a comma-separated list of addresses (may contain exclusion - see
           shorewall-exclusion[2] (5)).

           Beginning with Shorewall 4.5.7, all can be used as the zone name to mean all zones.

           Beginning with Shorewall 4.5.10, all- can be used as the zone name to mean all
           off-firewall zones.

       SOURCE (format 3 prior to Shorewall 5.1.0) – {-|interface[:address-list]|address-list}
           Where interface is an interface to that zone, and address-list is a comma-separated
           list of addresses (may contain exclusion - see shorewall-exclusion[2] (5)).

       SOURCE (format 3 on Shorewall 5.1.0 and later) - {-|[source-spec[,...]]}
           where source-spec is one of the following:

           interface
               Where interface is the logical name of an interface defined in
               shorewall-interface[3](5).

           address[,...][exclusion]
               where address may be:

               •   A host or network IP address.

               •   A MAC address in Shorewall format (preceded by a tilde ("~") and using dash
                   ("-") as a separator.

               •   The name of an ipset preceded by a plus sign ("+"). See
                   shorewall-ipsets[4](5).

               exclusion is described in shorewall-exclusion[2](5).

           interface:address[,...][exclusion]
               This form combines the preceding two and requires that both the incoming interface
               and source address match.

           exclusion
               See shorewall-exclusion[2] (5)

           Beginning with Shorewall 5.1.0, multiple source-specs separated by commas may be
           specified provided that the following alternative forms are used:
           (address[,...][exclusion])

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

           (exclusion)

       DEST (Prior to Shorewall 5.1.0) – {-|interface[:address-list]|address-list}
           where address-list is a comma-separated list of addresses (may contain exclusion - see
           shorewall-exclusion[2] (5)).

       DEST (Shorewall 5.1.0 and later) - {-|dest-spec[,...]}
           where dest-spec is one of the following:

           interface
               Where interface is the logical name of an interface defined in
               shorewall-interface[3](5).

           address[,...][exclusion]
               where address may be:

               •   A host or network IP address.

               •   A MAC address in Shorewall format (preceded by a tilde ("~") and using dash
                   ("-") as a separator.

               •   The name of an ipset preceded by a plus sign ("+"). See
                   shorewall-ipsets[4](5).

               exclusion is described in shorewall-exclusion[2](5).

           interface:address[,...][exclusion]
               This form combines the preceding two and requires that both the outgoing interface
               and destination address match.

           exclusion
               See shorewall-exclusion[2] (5)

           Beginning with Shorewall 5.1.0, multiple source-specs separated by commas may be
           specified provided that the following alternative forms are used:
           (address[,...][exclusion])

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

           (exclusion)

       PROTO – protocol-name-or-number[,...]
           A protocol name from /etc/protocols or a protocol number. tcp and 6 may be optionally
           followed by :syn to match only the SYN packet (first packet in the three-way
           handshake).

           Beginning with Shorewall 4.5.12, this column can accept a comma-separated list of
           protocols and either proto or protos is accepted in the alternate input format.

           Beginning with Shorewall 5.1.11, when tcp or 6 is specified and the ACTION is CT, the
           compiler will default to :syn. If you wish the rule to match packets with any valid
           combination of TCP flags, you may specify tcp:all or 6:all.

       DPORT - port-number/service-name-list
           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 - port-number/service-name-list
           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 DPORT. Use
           of '=' requires multi-port match in your iptables and kernel.

           This column was formerly labelled SOURCE PORT(S).

       USER – [user][:group]
           This column was formerly named USER/GROUP and may only be specified if the SOURCE zone
           is $FW. Specifies the effective user id and or group id of the process sending the
           traffic.

       SWITCH - [!]switch-name[={0|1}]
           Added in Shorewall 4.5.10 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.

           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.

EXAMPLE

       IPv4 Example 1:

           #ACTION                       SOURCE            DEST               PROTO            DPORT             SPORT               USER
           CT:helper:ftp(expevents=new)  fw                -                  tcp              21

       IPv4 Example 2 (Shorewall 4.5.10 or later):

       Drop traffic to/from all zones to IP address 1.2.3.4

           ?FORMAT 2
           #ACTION                       SOURCE             DEST               PROTO           DPORT             SPORT               USER
           DROP                          all-:1.2.3.4       -
           DROP                          all                1.2.3.4

       or

           ?FORMAT 3
           #ACTION                       SOURCE             DEST               PROTO           DPORT             SPORT               USER
           DROP:P                        1.2.3.4            -
           DROP:PO                       -                  1.2.3.4

       IPv6 Example 1:

       Use the FTP helper for TCP port 21 connections from the firewall itself.

           FORMAT 2
           #ACTION                       SOURCE            DEST               PROTO            DPORT             SPORT               USER
           CT:helper:ftp(expevents=new)  fw                -                  tcp              21

       IPv6 Example 2 (Shorewall 4.5.10 or later):

       Drop traffic to/from all zones to IP address 2001:1.2.3::4

           FORMAT 2
           #ACTION                       SOURCE             DEST               PROTO            DPORT             SPORT               USER
           DROP                          all-:2001:1.2.3::4 -
           DROP                          all                2001:1.2.3::4

       or

           FORMAT 3
           #ACTION                       SOURCE             DEST               PROTO            DPORT             SPORT               USER
           DROP:P                        2001:1.2.3::4      -
           DROP:PO                       -                  2001:1.2.3::4

FILES

       /etc/shorewall/conntrack

       /etc/shorewall6/conntrack

SEE ALSO

       http://www.shorewall.net/configuration_file_basics.htm#Pairs[5]

       shorewall(8)

NOTES

        1. shorewall-actions
           http://www.shorewall.net/manpages/shorewall-actions.html

        2. shorewall-exclusion
           http://www.shorewall.net/manpages/shorewall-exclusion.html

        3. shorewall-interface
           http://www.shorewall.netshorewall-interfaces.html

        4. shorewall-ipsets
           http://www.shorewall.netshorewall-ipsets.html

        5. http://www.shorewall.net/configuration_file_basics.htm#Pairs
           http://www.shorewall.net/configuration_file_basics.htm#Pairs