shorewall6-conntrack 5 conntrack shorewall6 conntrack file /etc/shorewall6/conntrack 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 two different column layouts: FORMAT 1, FORMAT 2, and FORMAT 3, 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 the word 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. 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:notrack}[:chain-designator] This column is only present when FORMAT = 2. Values other than NOTRACK require CT Target support in your iptables and kernel. NOTRACK or CT:notrack Disables connection tracking for this packet. DROP Added in Shorewall 4.5.10. Silently discard the packet. helper:name Attach the helper identified by the name to this connection. This is more flexible than loading the conntrack helper with preset ports. 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. When FORMAT = 1, this column is not present and the rule is processed as if NOTRACK had been entered in this column. Beginning with Shoreall 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 shorewall6-exclusion (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. In 4.5.10, handling of all was changed. all now causes the generated netfilter rule to be appended to the raw table PREROUTING and OUTPUT chains directly. all- rules are added directly to PREROUTING. all and all- rules are processed after the more specific rules that specify an individual zone. SOURCE (formats 3) ‒ {-|[:interface][: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 (5)). COMMENT is only allowed in format 1; the remainder of the line is treated as a comment that will be associated with the generated rule(s). DEST ‒ [interface|address-list] where address-list is a comma-separated list of addresses (may contain exclusion - see shorewall6-exclusion (5)). If an interface is given: It must be up and configured with an IPv6 address when Shorewall is started or restarted. All routes out of the interface must be configured when Shorewall is started or restarted. Default routes out of the interface will result in a warning message and will be ignored. PROTO ‒ protocol-name-or-number A protocol name from /etc/protocols or a protocol number. DEST PORT(S) (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. SOURCE 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. USER/GROUP (user) ‒ [user][:group] 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 Added in Shorewall6 4.5.10 and allows enabling and disabling the rule without requiring shorewall6 restart. Enables the rule if the value stored in /proc/net/nf_condition/switch-name is 1. Disables the rule 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. The switch-name 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 shorewall6 restart. Example 1: Use the FTP helper for TCP port 21 connections from the firewall itself. FORMAT 2 #ACTION SOURCE DEST PROTO DEST SOURCE USER/GROUP # PORT(S) PORT(S) CT:helper:ftp(expevents=new) fw - tcp 21 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 DEST SOURCE USER/GROUP # PORT(S) PORT(S) DROP all-:2001:1.2.3::4 - DROP all 2001:1.2.3::4 orFORMAT 3 #ACTION SOURCE DEST PROTO DEST SOURCE USER/GROUP # PORT(S) PORT(S) DROP:P 2001:1.2.3::4 - DROP:PO - 2001:1.2.3::4 /etc/shorewall6/notrack http://shorewall.net/configuration_file_basics.htm#Pairs shorewall6(8), shorewall6-accounting(5), shorewall6-actions(5), shorewall6-blacklist(5), shorewall6-hosts(5), shorewall6-interfaces(5), shorewall6-ipsec(5), shoewall6-netmap(5),shorewall6-params(5), shorewall6-policy(5), shorewall6-providers(5), shorewall6-proxyarp(5), shorewall6-rtrules(5), shorewall6-routestopped(5), shorewall6-rules(5), shorewall6.conf(5), shorewall6-secmarks(5), shorewall6-tcclasses(5), shorewall6-tcdevices(5), shorewall6-tcrules(5), shorewall6-tos(5), shorewall6-tunnels(5), shorewall-zones(5)