Description

shorewall6-rules 5 Configuration Files rules Shorewall6 rules file /etc/shorewall6/rules Description Entries in this file govern connection establishment by defining exceptions to the policies laid out in shorewall6-policy(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 QUEUE rules. 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. 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 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 and QUEUE There is an implicit rule added at the end of this section that invokes the RELATED_DISPOSITION (shorewall6.conf(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 and QUEUE. There is an implicit rule added at the end of this section that invokes the INVALID_DISPOSITION (shorewall6.conf(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 and QUEUE. There is an implicit rule added at the end of this section that invokes the UNTRACKED_DISPOSITION (shorewall6.conf(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. 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 omit the ESTABLISHED and RELATED sections and place all of your rules in the NEW section (That's after the line that reads ?SECTION NEW'). If you specify FASTACCEPT=Yes in shorewall6.conf(5) then the ESTABLISHED and RELATED sections must be empty. An except 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. 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. Requires Shorewall 4.5.14 or later. ACCEPT! like ACCEPT but exempts the rule from being suppressed by OPTIMIZE=1 in shorewall6.conf(5). action The name of an action declared in shorewall6-actions(5) or in /usr/share/shorewall/actions.std. ADD(ipset:flags) 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 is assumed. Require AUDIT_TARGET support in the kernel and iptables. A_ACCEPT, and A_ACCEPT! Added in Shorewall 4.4.20. Audited versions of ACCEPT and ACCEPT! respectively. Require AUDIT_TARGET support in the kernel and iptables. 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. Beginning with Shorewall 4.5.11, ?COMMENT is a synonym for COMMENT and is preferred. 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 shorewall6-zones(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 shorewall6-nesting(5) for additional information. CONTINUE! like CONTINUE but exempts the rule from being suppressed by OPTIMIZE=1 in shorewall6.conf(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). 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. 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 shorewall6.conf(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 ip6tables syntax. The part that you specify must follow a semicolon (';') 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. In this case, you must declare the target as a builtin action in shorewall6-actions(5). Some considerations when using INLINE: The , , , , , , and state match ( or ) 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 ';'. IP6TABLES({ip6tables-target [option ...]) 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 shorewall6-actions(5). 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 http://www.shorewall.net/shorewall_logging.html. 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 and the invocation of that action or macro specifies a log level. NFQUEUE[([queuenumber1[:queuenumber2][,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 is silently bypassed instead. The packet will move on to the next rule. 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. NFQUEUE![([queuenumber1[,queuenumber2][,bypass]]|bypass)] like NFQUEUE but exempts the rule from being suppressed by OPTIMIZE=1 in shorewall6.conf(5). NONAT Excludes the connection from any subsequent DNAT[-] or REDIRECT[-] rules but doesn't generate a rule to accept the traffic. 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 shorewall6.conf(5). REDIRECT Redirect the request to a server running on the firewall. 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. Requires Shorewall 4.5.14 or later. 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 option values are: (the PROTO column must specify TCP) REJECT! like REJECT but exempts the rule from being suppressed by OPTIMIZE=1 in shorewall6.conf(5). 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. 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 shorewall6-actions(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 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 (http://www.netfilter.org/projects/ulogd/index.html). 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 shorewall6.conf(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 shorewall6-zones(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". If the "-" is included, the firewall zone is omitted. 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 shorewall6-interfaces(5) or shorewall6-hosts(5). Only packets from hosts in the zone that arrive through the named interface will match the rule. zone:address[,...] where address can be: A host or network IP address. IPv6 ddresses must follow the standard convention and be enclosed in square brackets (e.g., [2001:470:b:227::0]/64). A network address may be followed by exclusion (see shorewall6-exclusion(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 shorewall6-interfaces (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 shorewall6-exclusion(5)). 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)

Examples: 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. $FW:&eth0 The primary IP address of eth0 in the firewall zone (Shorewall6 4.4.17 and later). 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 shorewall6-zones(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". If the "-" is included, the firewall zone is omitted. 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 shorewall6-interfaces(5) or shorewall6-hosts(5). Only packets to hosts in the zone that are sent through the named interface will match the rule. zone:address[,...] where address can be: A host or network IP address. A network address may be followed by exclusion (see shorewall6-exclusion(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 shorewall6-interfaces (5). zone:interface:address[,...] This form combines the preceding two and requires that both the outgoing interface and destinationaddress match. zone:exclusion This form matches if the host IP address does not match any of the entries in the exclusion (see shorewall6-exclusion(5)). [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. When omitting the server-IP, simply enter "[]" (e.g., loc:[]:3128). 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: the SOURCE must be , or the SOURCE zone must be another bport zone associated with the same bridge, or the SOURCE zone must be an ipv6 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)

Multiple dest-specs are not permitted in DNAT[-] and REDIRECT[-] rules. PROTO - {-|tcp:syn|ipp2p|ipp2p:udp|ipp2p:all|protocol-number|protocol-name|all} Optional protocol - ipp2p* requires ipp2p match support in your kernel and ip6tables. tcp:syn implies tcp plus the SYN flag must be set and the RST,ACK and FIN flags must be reset. Beginning with Shorewall6 4.4.19, this column can contain a comma-separated list of protocol-numbers and/or protocol names (e.g., tcp,udp). 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 http://www.shorewall.net/configuration_file_basics.htm#ICMP. Note that prior to Shorewall6 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 in this list and the SPORT list below if: 1. There are 15 or less ports listed. 2. No port ranges are included or your kernel and ip6tables 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 source port(s). 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 DPORT. Use of '=' requires multi-port match in your iptables and kernel. 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 a later 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 ip6tables 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 - [-] Included for compatibility with Shorewall. Enter '-' in this column if you need to specify one of the later columns. This column was formerly labelled ORIGINAL DEST. RATE - limit where limit is one of: [-|[{s|d}:[[name]:]]]rate/{sec|min|hour|day}[:burst] [name1]:rate1/{sec|min|hour|day}[:burst1],[name2]: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 or 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 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. This column was formerly labelled RATE LIMIT. USER - [!][user-name-or-number-or-range][:group-name-or-number-or-range] 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 ip6tables. 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 , , , , , or monthdays=dd[,dd],... where dd is an ordinal day of the month datestart=yyyy[-mm[-dd[hh[:mm[:ss]]]]] Defines the starting date and time. datestop=yyyy[-mm[-dd[hh[:mm[:ss]]]]] Defines the ending date and time. HEADERS - [!][any:|exactly:]header-list (Optional - Added in Shorewall 4.4.15) 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 Shorewall6 4.4.24 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. 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 shorewall6 restart. Beginning with Shorewall 4.5.10, when the switch-name is followed by or , 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: If the HELPERS option is specified in shorewall6.conf(5), then any module specified in this column must be listed in the HELPERS setting. Example Example 1: Accept SMTP requests from the DMZ to the internet #ACTION SOURCE DEST PROTO DPORT SPORT ORIGDEST ACCEPT dmz net tcp smtp Example 4: 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 Example 5: 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 6: Forward port 80 to dmz host $BACKUP if switch 'primary_down' is set. #ACTION SOURCE DEST PROTO DPORT SPORT ORIGDEST RATE USER MARK CONNLIMIT TIME HEADERS SWITCH DNAT net dmz:$BACKUP tcp 80 - - - - - - - - primary_down Example 7: Drop all email from IP addresses in the country whose ISO-3661 country code is ZZ. #ACTION SOURCE DEST PROTO DPORT DROP net:^ZZ fw tcp 25 Example 8: You want to generate your own rule involving ip6tables 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 ip6tables-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 shorewall6-actions(5): #ACTION OPTIONS SECCTX builtin FILES /etc/shorewall6/rules See ALSO http://www.shorewall.net/shorewall_logging.html http://www.shorewall.net/configuration_file_basics.htm#Pairs shorewall6(8), shorewall6-accounting(5), shorewall6-actions(5), shorewall6-blacklist(5), shorewall6-blrules(5), shorewall6-hosts(5), shorewall6-interfaces(5), shorewall6-maclist(5), shorewall6-netmap(5),shorewall6-params(5), shorewall6-policy(5), shorewall6-providers(5), shorewall6-rtrules(5), shorewall6-routestopped(5), shorewall6.conf(5), shorewall6-secmarks(5), shorewall6-tcclasses(5), shorewall6-tcdevices(5), shorewall6-mangle(5), shorewall6-tos(5), shorewall6-tunnels(5), shorewall6-zones(5)