Provided by:
shorewall-common_4.0.6-1_all 
NAME
rules - Shorewall rules file
SYNOPSIS
/etc/shorewall/rules
DESCRIPTION
Entries in this file govern connection establishment by defining
exceptions to the policies layed out in shorewall-policy
〈shorewall-policy.html〉 (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.
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:
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 ACCEPT rule inserted at the end of this
section.
NEW Packets in the NEW and INVALID states are processed by rules 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 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’).
Warning
If you specify FASTACCEPT=Yes in shorewall.conf
〈shorewall.conf.html〉 (5) then the ESTABLISHED and RELATED
sections must be empty.
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 ORIGINAL DEST column gives the original
destination IP address of the packet and the DEST PORT(S) column give
the original destination port(s).
The columns in the file are as follows.
ACTION —
{ACCEPT[+|!]|NONAT|DROP[!]|REJECT[!]|DNAT[-]|SAME[-]|REDIRECT[-]|CONTINUE[!]|LOG|QUEUE[!]|NFQUEUE[/queuenumber]|COMMENT|action|macro[/target]}[:{log-
level|none}[!][:tag]]
Specifies the action to be taken if the connection request
matches the rule. 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
ACCEPT!
like ACCEPT but exempts the rule from being suppressed by
OPTIMIZE=1 in shorewall.conf 〈shorewall.conf.html〉 (5).
NONAT Excludes the connection from any subsequent DNAT[-] or
REDIRECT[-] rules but doesn’t generate a rule to accept
the traffic.
DROP Ignore the request.
DROP! like DROP but exempts the rule from being suppressed by
OPTIMIZE=1 in shorewall.conf 〈shorewall.conf.html〉 (5).
REJECT disallow the request and return an icmp-unreachable or an
RST packet.
REJECT!
like REJECT but exempts the rule from being suppressed by
OPTIMIZE=1 in shorewall.conf 〈shorewall.conf.html〉 (5).
DNAT Forward the request to another system (and optionally
another port).
DNAT- Advanced users only.
Like DNAT but only generates the DNAT iptables rule and
not the companion ACCEPT rule.
SAME Similar to DNAT except that the port may not be remapped
and when multiple server addresses are listed, all
requests from a given remote system go to the same
server.
Warning
Support for SAME is scheduled for removal from the Linux
kernel in 2008.
SAME- Advanced users only.
Like SAME but only generates the nat iptables rule and
not the companion ACCEPT rule.
REDIRECT
Redirect the request to a server running on the firewall.
REDIRECT-
Advanced users only.
Like REDIRECT but only generates the REDIRECT iptables
rule and not the companion ACCEPT rule.
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 〈shorewall-zones.html〉 (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
〈shorewall-nesting.html〉 (5) for additional information.
CONTINUE!
like CONTINUE but exempts the rule from being suppressed
by OPTIMIZE=1 in shorewall.conf 〈shorewall.conf.html〉
(5).
LOG Simply log the packet and continue with the next rule.
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 〈shorewall.conf.html〉 (5).
NFQUEUE
Only supported by Shorewall-perl >= 4.0.3.
Queues the packet to a user-space application using the
nfnetlink_queue mechanism. If a queuenumber is not
specified, queue zero (0) is assumed.
NFQUEUE!
like NFQUEUE but exempts the rule from being suppressed
by OPTIMIZE=1 in shorewall.conf 〈shorewall.conf.html〉
(5).
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.
action The name of an action declared in shorewall-actions
〈shorewall-actions.html〉 (5) or in
/usr/share/shorewall/actions.std.
macro 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 "/" and the target
(ACCEPT, DROP, REJECT, ...) to be substituted for the
parameter.
Example: FTP/ACCEPT.
The ACTION may optionally be followed by ":" and a syslog log
level (e.g, REJECT:info or DNAT:debug). This causes the packet
to be logged at the specified level. Note that if the ACTION
involves destination network address translation (DNAT,
REDIRECT, SAME, etc.) then the packet is logged before the
destination address is rewritten.
If the ACTION names an action declared in shorewall-actions
〈shorewall-actions.html〉 (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 (must be in upper case) as a log
level.This will log to the ULOG 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 shorewall.conf
〈shorewall.conf.html〉 (5)).
Example: ACCEPT:info:ftp would include ’ftp ’ at the end of the
log prefix generated by the LOGPREFIX setting.
SOURCE — {zone|all[+][-]}[:interface][:{address-or-range[,address-or-
range]...[exclusion]|exclusion|+ipset}
Source hosts to which the rule applies. May be a zone declared
in /etc/shorewall/zones, $FW to indicate the firewall itself,
all, all+, all-, all+- or none.
When none is used either in the SOURCE or DEST column, the rule
is ignored.
all means "All Zones", including the firewall itself. all- means
"All Zones, except the firewall itself". When all[-] is used
either in the SOURCE or DEST column intra-zone traffic is not
affected. When all+[-] is "used, intra-zone traffic is affected.
Except when all[+][-] is specified, clients may be further
restricted to a list of networks and/or hosts by appending ":"
and a comma-separated list of network and/or host addresses.
Hosts may be specified by IP or MAC address; mac addresses must
begin with "~" and must use "-" as a separator.
Hosts may also be specified as an IP address range using the
syntax lowaddress-highaddress. This requires that your kernel
and iptables contain iprange match support. If your kernel and
iptables have ipset match support then you may give the name of
an ipset prefaced by "+". The ipset name may be optionally
followed by a number from 1 to 6 enclosed in square brackets
([]) to indicate the number of levels of source bindings to be
matched.
You may exclude certain hosts from the set already defined
through use of an exclusion (see shorewall-exclusion
〈shorewall-exclusion.html〉 (5)).
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
Alternatively, clients may be specified by interface by
appending ":" to the zone name followed by the interface name.
For example, loc:eth1 specifies a client that communicates with
the firewall system through eth1. This may be optionally
followed by another colon (":") and an IP/MAC/subnet address as
described above (e.g., loc:eth1:192.168.1.5).
DEST — {zone|all[+][-]}[:{interface|address-or-range[,address-or-
range]...[exclusion]|exclusion|+ipset}][:port[:random]]
Location of Server. May be a zone declared in shorewall-zones
〈shorewall-zones.html〉 (5), $FW to indicate the firewall itself,
all. all+ or none.
When none is used either in the SOURCE or DEST column, the rule
is ignored.
When all is used either in the SOURCE or DEST column intra-zone
traffic is not affected. When all+ is used, intra-zone traffic
is affected.
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.
Except when all[+]|[-] is specified, the server may be further
restricted to a particular network, host or interface by
appending ":" and the network, host or interface. See SOURCE
above.
You may exclude certain hosts from the set already defined
through use of an exclusion (see shorewall-exclusion
〈shorewall-exclusion.html〉 (5)).
Restrictions:
1. MAC addresses are not allowed (this is a Netfilter
restriction).
2. In DNAT rules, only IP addresses are allowed; no FQDNs or
subnet addresses are permitted.
3. You may not specify both an interface and an address.
Like in the SOURCE column, you may specify a range of IP
addresses using the syntax lowaddress-highaddress. When the
ACTION is DNAT or DNAT-, the connections will be assigned to
addresses in the range in a round-robin fashion.
If you kernel and iptables have ipset match support then you may
give the name of an ipset prefaced by "+". The ipset name may be
optionally followed by a number from 1 to 6 enclosed in square
brackets ([]) to indicate the number of levels of destination
bindings to be matched. Only one of the SOURCE and DEST columns
may specify an ipset name.
The port that the server is listening on may be included and
separated from the server’s IP address by ":". If omitted, the
firewall will not modifiy the destination port. A destination
port may only be included if the ACTION is DNAT or REDIRECT.
Example:
loc:192.168.1.3:3128 specifies a local server at
IP address 192.168.1.3 and listening on port
3128.
If you are using Shorewall-shell or Shorewall-perl before
version 4.0.5, then the port number MUST be specified as an
integer and not as a name from services(5). Shorewall-perl 4.0.5
and later permit the port to be specified as a service name.
Additionally, Shorewall-perl 4.0.5 and later permit specifying a
port range in the form lowport-highport to cause connections to
be assigned to ports in the range in round-robin fashion. When a
port range is specified, lowport and highport must be given as
integers; service names are not permitted. Beginning with
Shorewall 4.0.6, the port range may be optionally followed by
:random which causes assignment to ports in the list to be
random.
If the ACTION is REDIRECT or REDIRECT-, this column needs only
to contain the port number on the firewall that the request
should be redirected to. That is equivalent to specifying
$FW::port.
PROTO (Optional) — {-|tcp:syn|ipp2p|ipp2p:udp|ipp2p:all|protocol-
number|protocol-name|all}
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.
DEST PORT(S) (Optional) — {-|port-name-number-or-range[,port-name-
number-or-range]...}
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).
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
CLIENT PORT(S) list below:
1. There are 15 or less ports listed.
2. No port ranges are included or your kernel and iptables
contain extended multiport match support.
Otherwise, unless you are using Shorewall-perl
〈../Shorewall-perl.html〉 , a separate rule will be generated for
each port. Shorewall-perl does not automatically break up lists
into individual rules.
SOURCE PORT(S) (Optional) — {-|port-name-number-or-range[,port-name-
number-or-range]...}
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.
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 ORIGINAL DEST 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
DEST PORT(S) list above:
1. There are 15 or less ports listed.
2. No port ranges are included or your kernel and iptables
contain extended multiport match support.
Otherwise, unless you are using Shorewall-perl
〈../Shorewall-perl.html〉 , a separate rule will be generated for
each port. Shorewall-perl does not automatically break up lists
into individual rules.
ORIGINAL DEST (Optional) —
[-|address[,address]...[exclusion]|exclusion]
If ACTION is DNAT[-] or REDIRECT[-] then if this column is
included and is different from the IP address given in the
SERVER 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.
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 〈shorewall-exclusion.html〉 (5).
See http://shorewall.net/PortKnocking.html
〈../PortKnocking.html〉 for an example of using an entry in this
column with a user-defined action rule.
RATE LIMIT (Optional) — [-|rate/{sec|min}[:burst]
You may 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 whitespace embedded in
the specification.
Example: 10/sec:20
USER/GROUP (Optional) — [!][user-name-or-number][:group-name-or-
number][+program-name]
This 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
+upnpd #program named upnpd
Important
The ability to specify a program name was removed from
Netfilter in kernel version 2.6.14.
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. This option is only supported by
Shorewall-perl.
RESTRICTIONS
Unless you are using Shorewall-perl 〈../Shorewall-perl.html〉 and your
iptables/kernel have Repeat Match support (see the output of shorewall
show capabilities), if you specify a list of DEST PORT(S), then you may
not specify SOURCE PORT(S) and vice versa.
EXAMPLE
Example 1:
Accept SMTP requests from the DMZ to the internet
#ACTION SOURCE DEST PROTO DEST SOURCE ORIGINAL
# PORT PORT(S) DEST
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 DEST SOURCE ORIGINAL
# PORT PORT(S) DEST
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 DEST SOURCE ORIGINAL RATE
# PORT PORT(S) DEST LIMIT
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 DEST SOURCE ORIGINAL
# PORT PORT(S) DEST
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 DEST SOURCE ORIGINAL
# PORT PORT(S) DEST
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 DEST SOURCE ORIGINAL
# PORT PORT(S) DEST
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 DEST SOURCE ORIGINAL
# PORT PORT(S) DEST
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 DEST SOURCE ORIGINAL
# PORT PORT(S) DEST
REDIRECT net $FW::81-90:random tcp www
FILES
/etc/shorewall/rules
SEE ALSO
shorewall(8), shorewall-accounting(5), shorewall-actions(5), shorewall-
blacklist(5), shorewall-hosts(5), shorewall-interfaces(5), shorewall-
ipsec(5), shorewall-maclist(5), shorewall-masq(5), shorewall-nat(5),
shorewall-netmap(5), shorewall-params(5), shorewall-policy(5),
shorewall-providers(5), shorewall-proxyarp(5), shorewall-
route_routes(5), shorewall-routestopped(5), shorewall.conf(5),
shorewall-tcclasses(5), shorewall-tcdevices(5), shorewall-tcrules(5),
shorewall-tos(5), shorewall-tunnels(5), shorewall-zones(5)
23 November 2007 shorewall-rules(5)