Provided by: shorewall_5.1.12.2-1_all 
NAME
mangle - Shorewall Packet marking/mangling rules file
SYNOPSIS
/etc/shorewall[6]/mangle
DESCRIPTION
This file was introduced in Shorewall 4.6.0 and replaces shorewall-tcrules(5)[1]. This file is only
processed by the compiler if:
Entries in this file cause packets to be marked as a means of classifying them for traffic control or
policy routing.
Important
Unlike rules in the shorewall-rules[2](5) file, evaluation of rules in this file will continue after
a match. So the final mark for each packet will be the one assigned by the LAST tcrule that matches.
If you use multiple internet providers with the 'track' option, in /etc/shorewall/providers be sure
to read the restrictions at http://www.shorewall.net/MultiISP.html[3].
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 - command[(parameters)][:chain-designator]
The chain-designator indicates the Netfilter chain that the entry applies to and may be one of the
following:
P
PREROUTING chain.
F
FORWARD chain.
T
POSTROUTING chain.
I
INPUT chain.
Unless otherwise specified for the particular command, the default chain is PREROUTING when
MARK_IN_FORWARD_CHAIN=No in shorewall.conf(5)[4], and FORWARD when MARK_IN_FORWARD_CHAIN=Yes.
A chain-designator may not be specified if the SOURCE or DEST columns begin with '$FW'. When the
SOURCE is $FW, the generated rule is always placed in the OUTPUT chain. If DEST is '$FW', then the
rule is placed in the INPUT chain. Additionally, a chain-designator may not be specified in an action
body.
Where a command takes parameters, those parameters are enclosed in parentheses ("(....)") and
separated by commas.
The command may be one of the following.
action[([param[,...])]
Added in Shorewall 5.0.7. action must be an action declared with the mangle option in
shorewall-actions(5)[5]. If the action accepts parameters, they are specified as a
comma-separated list within parentheses following the action name.
ADD(ipset:flags)
Added in Shorewall 4.6.7. 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)).
ADD is non-terminating. Even if a packet matches the rule, it is passed on to the next rule.
CHECKSUM
Compute and fill in the checksum in a packet that lacks a checksum. This is particularly useful
if you need to work around old applications, such as dhcp clients, that do not work well with
checksum offloads, but you don't want to disable checksum offload in your device.
Requires 'Checksum Target' support in your kernel and iptables.
CLASSIFY(classid)
A classification Id (classid) is of the form major:minor where major and minor are integers.
Corresponds to the 'class' specification in these traffic shaping modules:
atm
cbq
dsmark
pfifo_fast
htb
prio
Classification occurs in the POSTROUTING chain except when the SOURCE is $FW[:address] in which
case classification occurs in the OUTPUT chain.
When using Shorewall's built-in traffic shaping tool, the major class is the device number (the
first device in shorewall-tcdevices[6](5) is major class 1, the second device is major class 2,
and so on) and the minor class is the class's MARK value in shorewall-tcclasses[7](5) preceded by
the number 1 (MARK 1 corresponds to minor class 11, MARK 5 corresponds to minor class 15, MARK 22
corresponds to minor class 122, etc.).
?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 mangle
To stop the comment from being attached to further rules, simply include ?COMMENT on a line by
itself.
CONMARK({mark|range})
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
Don't process any more marking rules in the table.
Currently, CONTINUE may not be used with exclusion (see the SOURCE and DEST columns below); that
restriction will be removed when iptables/Netfilter provides the necessary support.
DEL(ipset:flags)
Added in Shorewall 4.6.7. 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.
DIVERT
Two DIVERT rule should precede the TPROXY rule and should select DEST PORT tcp 80 and SOURCE PORT
tcp 80 respectively (assuming that tcp port 80 is being proxied). DIVERT avoids sending packets
to the TPROXY target once a socket connection to Squid3 has been established by TPROXY. DIVERT
marks the packet with a unique mark and exempts it from any rules that follow.
DIVERTHA
Added in Shorewall 5.0.4. To setup the HAProxy configuration described at
http://www.loadbalancer.org/blog/setting-up-haproxy-with-transparent-mode-on-centos-6-x, place
this entry in shorewall-providers(5)[8]:
#NAME NUMBER MARK DUPLICATE INTERFACE GATEWAY OPTIONS COPY
TProxy 1 - - lo - tproxy
and use this DIVERTHA entry:
#ACTION SOURCE DEST PROTO DPORT SPORT USER TEST LENGTH TOS CONNBYTES HELPER PROBABILITY DSCP
DIVERTHA - - tcp
DROP
Causes matching packets to be discarded.
DSCP(dscp)
Sets the Differentiated Services Code Point field in the IP header. The dscp value may be given
as an even number (hex or decimal) or as the name of a DSCP class. Valid class names and their
associated hex numeric values are:
CS0 => 0x00
CS1 => 0x08
CS2 => 0x10
CS3 => 0x18
CS4 => 0x20
CS5 => 0x28
CS6 => 0x30
CS7 => 0x38
BE => 0x00
AF11 => 0x0a
AF12 => 0x0c
AF13 => 0x0e
AF21 => 0x12
AF22 => 0x14
AF23 => 0x16
AF31 => 0x1a
AF32 => 0x1c
AF33 => 0x1e
AF41 => 0x22
AF42 => 0x24
AF43 => 0x26
EF => 0x2e
To indicate more than one class, add their hex values together and specify the result. By
default, DSCP rules are placed in the POSTROUTING chain.
ECN
Added in Shorewall 5.0.6 as an alternative to entries in shorewall-ecn(5)[9]. If a PROTO is
specified, it must be 'tcp' (6). If no PROTO is supplied, TCP is assumed. This action causes all
ECN bits in the TCP header to be cleared.
IMQ(number)
Specifies that the packet should be passed to the IMQ identified by number. Requires IMQ Target
support in your kernel and iptables.
INLINE[(action)]
Allows you to place your own ip[6]tables matches at the end of the line following two semicolons
(";;") (preferred) or a single semicolon (";") (deprecated). If an action is specified, the
compiler proceeds as if that action had been specified in this column. If no action is specified,
then you may include your own jump ("-j target [option] ...") after any matches specified at the
end of the rule. If the target is not one known to Shorewall, then it must be defined as a
builtin action in shorewall-actions[10] (5).
The following rules are equivalent:
2:P eth0 - tcp 22
INLINE(MARK(2)):P eth0 - tcp 22
INLINE(MARK(2)):P eth0 - ;; -p tcp
INLINE eth0 - tcp 22 ;; -j MARK --set-mark 2
INLINE eth0 - ;; -p tcp -j MARK --set-mark 2
IPMARK
Assigns a mark to each matching packet based on the either the source or destination IP address.
By default, it assigns a mark value equal to the low-order 8 bits of the source address. Default
values are:
src
mask1 = 0xFF
mask2 = 0x00
shift = 0
'src' and 'dst' specify whether the mark is to be based on the source or destination address
respectively. The selected address is first shifted to the right by shift bits. The result is
then LANDed with mask1 then LORed with mask2.
In a sense, the IPMARK target is more like an IPCLASSIFY target in that the mark value is later
interpreted as a class ID. A packet mark is 32 bits wide; so is a class ID. The <major> class
occupies the high-order 16 bits and the <minor> class occupies the low-order 16 bits. So the
class ID 1:4ff (remember that class IDs are always in hex) is equivalent to a mark value of
0x104ff. Remember that Shorewall uses the interface number as the <major> number where the first
interface in tcdevices has <major> number 1, the second has <major> number 2, and so on.
The IPMARK target assigns a mark to each matching packet based on the either the source or
destination IP address. By default, it assigns a mark value equal to the low-order 8 bits of the
source address. The syntax is as follows: IPMARK[([{src|dst}][,[mask1][,[mask2][,[shift]]]])]
Default values are:
src
mask1 = 0xFF
mask2 = 0x00
shift = 0
src and dst specify whether the mark is to be based on the source or destination address
respectively. The selected address is first shifted right by shift, then LANDed with mask1 and
then LORed with mask2. The shift argument is intended to be used primarily with IPv6 addresses.
Example: IPMARK(src,0xff,0x10100)
Suppose that the source IP address is 192.168.4.3
= 0xc0a80403; then
0xc0a80403 >> 0 = 0xc0a80403
0xc0a80403 LAND 0xFF = 0x03
0x03 LOR 0x10100 = 0x10103 or class ID
1:103
It is important to realize that, while class IDs are composed of a major and a minor value, the
set of values must be unique. That is, the same numeric value cannot be used as both a major and
a minor number for the same interface unless class nesting occurs (which is not currently
possible with Shorewall). You should keep this in mind when deciding how to map IP addresses to
class IDs.
For example, suppose that your internal network is 192.168.1.0/29 (host IP addresses 192.168.1.1
- 192.168.1.6). Your first notion might be to use IPMARK(src,0xFF,0x10000) so as to produce class
IDs 1:1 through 1:6. But 1:1 is an invalid class ID since the major and minor classes are equal.
So you might choose instead to use IPMARK(src,0xFF,0x10100) as in the example above so that all
of your minor classes will have a value > 256.
IP6TABLES({target [option ...])
IPv6 only.
This action allows you to specify an iptables target with options (e.g., 'IP6TABLES(MARK
--set-xmark 0x01/0xff)'. 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 the target as a builtin action in
shorewall-actions(5)[10].
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 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 the target as a builtin action in
shorewall-actions(5)[10].
MARK({mark|range})
where mark is a packet mark value.
Normally will set the mark value. 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.
A mark range is a pair of integers separated by a dash ("-").
May be optionally followed by a slash ("/") and a mask and requires the Statistics Match
capability in iptables and kernel. Marks in the specified range are assigned to packets on a
round-robin fashion.
When a mask is specified, the result of logically ANDing each mark value with the mask must be
the same as the mark value. The least significant bit in the mask is used as an increment. For
example, if '0x200-0x400/0xff00' is specified, then the assigned mark values are 0x200, 0x300 and
0x400 in equal proportions. If no mask is specified, then ( 2 ** MASK_BITS ) - 1 is assumed
(MASK_BITS is set in shorewall.conf[4](5)).
NFLOG[(nflog-parameters)]
Added in Shorewall 5.0.9. Logs matching packets using NFLOG. 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.
RESTORE[(mask)]
Restore the packet's mark from the connection's mark using the supplied mask if any. Your kernel
and iptables must include CONNMARK support.
SAME[(timeout)]
Some websites run applications that require multiple connections from a client browser. Where
multiple 'balanced' providers are configured, this can lead to problems when some of the
connections are routed through one provider and some through another. The SAME target allows you
to work around that problem. SAME may be used in the PREROUTING and OUTPUT chains. When used in
PREROUTING, it causes matching connections from an individual local system to all use the same
provider. For example:
#ACTION SOURCE DEST PROTO DPORT
SAME:P 192.168.1.0/24 0.0.0.0/0 tcp 80,443
If a host in 192.168.1.0/24 attempts a connection on TCP port 80 or 443 and it has sent a packet
on either of those ports in the last five minutes then the new connection will use the same
provider as the connection over which that last packet was sent.
When used in the OUTPUT chain, it causes all matching connections to an individual remote system
to all use the same provider. For example:
#ACTION SOURCE DEST PROTO DPORT
SAME $FW 0.0.0.0/0 tcp 80,443
The optional timeout parameter was added in Shorewall 4.6.7 and specifies a number of seconds .
When not specified, a value of 300 seconds (5 minutes) is assumed. If the firewall attempts a
connection on TCP port 80 or 443 and it has sent a packet on either of those ports in the last
timeout seconds to the same remote system then the new connection will use the same provider as
the connection over which that last packet was sent.
SAVE[(mask)]
Save the packet's mark to the connection's mark using the supplied mask if any. Your kernel and
iptables must include CONNMARK support.
TCPMSS([mss[,ipsec]])
Added in Shorewall 5.1.9. This target only applies to TCP traffic and alters the MSS value in SYN
packets. It may be used in the FORWARD and POSTROUTING chains; the default is FORWARD.
The mss parameter may be either pmtu or an integer in the range 500:65533. The value pmtu
automatically clamps the MSS value to (path_MTU - 40 for IPv4; -60 for IPv6). This may not
function as desired where asymmetric routes with differing path MTU exist — the kernel uses the
path MTU which it would use to send packets from itself to the source and destination IP
addresses. Prior to Linux 2.6.25, only the path MTU to the destination IP address was considered
by this option; subsequent kernels also consider the path MTU to the source IP address. If an
integer is given, the MSS option is set to the specified value. If the MSS of the packet is
already lower than mss, it will not be increased (from Linux 2.6.25 onwards) to avoid more
problems with hosts relying on a proper MSS. If mss is omitted, pmtu is assumed.
The ipsec parameter determines whether the rule applies to IPSEC traffic (ipsec is passed),
non-IPSEC traffic (none is passed) or both (all is passed). If omitted, all is assumed.
TOS(tos[/mask])
Sets the Type of Service field in the IP header. The tos value may be given as an number (hex or
decimal) or as the name of a TOS type. Valid type names and their associated hex numeric values
are:
Minimize-Delay => 0x10,
Maximize-Throughput => 0x08,
Maximize-Reliability => 0x04,
Minimize-Cost => 0x02,
Normal-Service => 0x00
To indicate more than one class, add their hex values together and specify the result.
When tos is given as a number, it may be optionally followed by '/' and a mask. When no mask is
given, the value 0xff is assumed. When tos is given as a type name, the mask 0x3f is assumed.
The action performed is to zero out the bits specified by the mask, then set the bits specified
by tos.
TPROXY([port[,address]])
Transparently redirects a packet without altering the IP header. Requires a tproxy provider to be
defined in shorewall-providers[8](5).
There are three parameters to TPROXY - neither is required:
• port - the port on which the proxy server is listening. If omitted, the original destination
port.
• address - a local (to the firewall) IP address on which the proxy server is listening. If
omitted, the IP address of the interface on which the request arrives.
TTL([-|+]number)
If + is included, packets matching the rule will have their TTL incremented by number. Similarly,
if - is included, matching packets have their TTL decremented by number. If neither + nor - is
given, the TTL of matching packets is set to number. The valid range of values for number is
1-255.
SOURCE - {-|source-spec[,...]}
where source-spec is one of:
interface
where interface is the logical name of an interface defined in shorewall-interfaces[11](5).
Matches packets entering the firewall from the named interface. May not be used in CLASSIFY rules
or in rules using the :T chain qualifier.
address[,...][exclusion]
where address is: A host or network IP address.
The name of an ipset preceded by a plus sign ("+").
A MAC address in Shorewall format (preceded by a tilde ("~") and using dash ("-") as a separator
(e.g., ~00-A0-C9-15-39-78). Matches traffic whose source IP address matches one of the listed
addresses and that does not match an address listed in the exclusion (see
shorewall-exclusion[12](5)).
This form will not match traffic that originates on the firewall itself unless either
<major><minor> or the :T chain qualifier is used in the ACTION column.
interface:address,[...][exclusion]
This form combines the preceding two forms and matches when both the incoming interface and
source IP address match.
interface:exclusion
This form matches packets arriving through the named interface and whose source IP address does
not match any of the addresses in the exclusion.
$FW
Matches packets originating on the firewall system. May not be used with a chain qualifier (:P,
:F, etc.) in the ACTION column.
$FW:address[,...][exclusion]
where address is as above (MAC addresses are not permitted). Matches packets originating on the
firewall and whose source IP address matches one of the listed addresses and does not match any
address listed in the exclusion. May not be used with a chain qualifier (:P, :F, etc.) in the
ACTION column.
$FW:exclusion
Matches traffic originating on the firewall, provided that the source IP address does not match
any address listed in the exclusion.
Beginning with Shorewall 5.1.0, multiple source_specs, separated by commas, may be given provided
that the following alternative forms are used: (address[,...][exclusion])
interface:(address[,...][exclusion])
interface:(exclusion)
$FW:(address[,...][exclusion])
$FW:(exclusion)
DEST - {-|dest-spec[,...]}
where dest-spec is one of:
interface
where interface is the logical name of an interface defined in shorewall-interfaces[11](5).
Matches packets leaving the firewall through the named interface. May not be used in the
PREROUTING chain (:P in the mark column or no chain qualifier and MARK_IN_FORWARD_CHAIN=No in
shorewall.conf[13] (5)).
address[,...][exclusion]
where address is: A host or network IP address.
The name of an ipset preceded by a plus sign ("+").
A MAC address in Shorewall format (preceded by a tilde ("~") and using dash ("-") as a separator
(e.g., ~00-A0-C9-15-39-78). Matches traffic whose destination IP address matches one of the
listed addresses and that does not match an address listed in the exclusion (see
shorewall-exclusion[12](5)).
interface:address,[...][exclusion]
This form combines the preceding two forms and matches when both the outgoing interface and
destination IP address match. May not be used in the PREROUTING chain (:P in the mark column or
no chain qualifier and MARK_IN_FORWARD_CHAIN=No in shorewall.conf[13] (5)).
interface:exclusion
This form matches packets leaving through the named interface and whose destination IP address
does not match any of the addresses in the exclusion. May not be used in the PREROUTING chain (:P
in the mark column or no chain qualifier and MARK_IN_FORWARD_CHAIN=No in shorewall.conf[13] (5)).
$FW
Matches packets originating on the firewall system. May not be used with a chain qualifier (:P,
:F, etc.) in the ACTION column.
$FW:address[,...][exclusion]
where address is as above (MAC addresses are not permitted). Matches packets destined for the
firewall and whose destination IP address matches one of the listed addresses and does not match
any address listed in the exclusion. May not be used with a chain qualifier (:P, :F, etc.) in the
ACTION column.
$FW:exclusion
Matches traffic destined for the firewall, provided that the destination IP address does not
match any address listed in the exclusion.
Beginning with Shorewall 5.1.0, multiple dest_specs, separated by commas, may be given provided that
the following alternative forms are used: (address[,...][exclusion])
interface:(address[,...][exclusion])
interface:(exclusion)
$FW:(address[,...][exclusion])
$FW:(exclusion)
PROTO - {-|{tcp:[!]syn|ipp2p|ipp2p:udp|ipp2p:all|protocol-number|protocol-name|all}[,...]}
See shorewall-rules(5)[2] 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]...|+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[14].
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.
An entry in this field requires that the PROTO column specify icmp (1), tcp (6), udp (17), sctp (132)
or udplite (136). Use '-' if any of the following field is supplied.
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 named 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.
An entry in this field requires that the PROTO column specify tcp (6), udp (17), sctp (132) or
udplite (136). Use '-' if any of the following fields is supplied.
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.
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).
USER - [!][user-name-or-number][:group-name-or-number][+program-name]
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
+upnpd
#program named upnpd
Important
The ability to specify a program name was removed from Netfilter in kernel version 2.6.14.
TEST - [!]value[/mask][:C]
Optional - 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.
LENGTH - [length|[min]:[max]]
Optional - packet payload length. This field, if present allow you to match the length of a packet
payload (Layer 4 data ) against a specific value or range of values. You must have iptables length
support for this to work. A range is specified in the form min:max where either min or max (but not
both) may be omitted. If min is omitted, then 0 is assumed; if max is omitted, than any packet that
is min or longer will match.
TOS - tos
Type of service. Either a standard name, or a numeric value to match.
Minimize-Delay (16)
Maximize-Throughput (8)
Maximize-Reliability (4)
Minimize-Cost (2)
Normal-Service (0)
CONNBYTES - [!]min:[max[:{O|R|B}[:{B|P|A}]]]
Optional connection Bytes; defines a byte or packet range that the connection must fall within in
order for the rule to match.
A packet matches if the the packet/byte count is within the range defined by min and max (unless ! is
given in which case, a packet matches if the packet/byte count is not within the range). min is an
integer which defines the beginning of the byte/packet range. max is an integer which defines the
end of the byte/packet range; if omitted, only the beginning of the range is checked. The first
letter gives the direction which the range refers to:O - The original direction of the connection.
.sp - The opposite direction from the original connection. .sp B - The total of both directions.
If omitted, B is assumed.
The second letter determines what the range refers to.B - Bytes .sp P - Packets .sp A - Average
packet size.If omitted, B is assumed.
HELPER - helper
Names a Netfilter protocol helper module such as ftp, sip, amanda, etc. A packet will match if it was
accepted by the named helper module.
Example: Mark all FTP data connections with mark 4:
#ACTION SOURCE DEST PROTO DPORT SPORT USER TEST LENGTH TOS CONNBYTES HELPER
4:T 0.0.0.0/0 0.0.0.0/0 TCP - - - - - - - ftp
PROBABILITY - [probability]
Added in Shorewall 4.5.0. 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.
DSCP - [[!]dscp]
Added in Shorewall 4.5.1. When non-empty, match packets whose Differentiated Service Code Point field
matches the supplied value (when '!' is given, the rule matches packets whose DSCP field does not
match the supplied value). The dscp value may be given as an even number (hex or decimal) or as the
name of a DSCP class. Valid class names and their associated hex numeric values are:
CS0 => 0x00
CS1 => 0x08
CS2 => 0x10
CS3 => 0x18
CS4 => 0x20
CS5 => 0x28
CS6 => 0x30
CS7 => 0x38
BE => 0x00
AF11 => 0x0a
AF12 => 0x0c
AF13 => 0x0e
AF21 => 0x12
AF22 => 0x14
AF23 => 0x16
AF31 => 0x1a
AF32 => 0x1c
AF33 => 0x1e
AF41 => 0x22
AF42 => 0x24
AF43 => 0x26
EF => 0x2e
STATE -- {NEW|RELATED|ESTABLISHED|INVALID} [,...]
The rule will only match if the packet's connection is in one of the listed states.
TIME - timeelement[&timeelement...]
Added in Shorewall 4.6.2.
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 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.
SWITCH - [!]switch-name[={0|1}]
Added in Shorewall 5.1.0 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:
Mark all ICMP echo traffic with packet mark 1. Mark all peer to peer traffic with packet mark 4.
This is a little more complex than otherwise expected. Since the ipp2p module is unable to determine
all packets in a connection are P2P packets, we mark the entire connection as P2P if any of the
packets are determined to match.
We assume packet/connection mark 0 means unclassified.
#ACTION SOURCE DEST PROTO DPORT SPORT USER TEST
MARK(1):T 0.0.0.0/0 0.0.0.0/0 icmp echo-request
MARK(1):T 0.0.0.0/0 0.0.0.0/0 icmp echo-reply
RESTORE:T 0.0.0.0/0 0.0.0.0/0 all - - - 0
CONTINUE:T 0.0.0.0/0 0.0.0.0/0 all - - - !0
MARK(4):T 0.0.0.0/0 0.0.0.0/0 ipp2p:all
SAVE:T 0.0.0.0/0 0.0.0.0/0 all - - - !0
If a packet hasn't been classified (packet mark is 0), copy the connection mark to the packet mark.
If the packet mark is set, we're done. If the packet is P2P, set the packet mark to 4. If the packet
mark has been set, save it to the connection mark.
IPv4 Example 2:
SNAT outgoing connections on eth0 from 192.168.1.0/24 in round-robin fashion between addresses
1.1.1.1, 1.1.1.3, and 1.1.1.9 (Shorewall 4.5.9 and later).
/etc/shorewall/mangle:
#ACTION SOURCE DEST PROTO DPORT SPORT USER TEST
CONNMARK(1-3):F 192.168.1.0/24 eth0 ; state=NEW
/etc/shorewall/snat:
#ACTION SOURCE DEST ...
SNAT(1.1.1.1) eth0:192.168.1.0/24 - { mark=1:C }
SNAT(1.1.1.3) eth0:192.168.1.0/24 - { mark=2:C }
SNAT(1.1.1.4) eth0:192.168.1.0/24 - { mark=3:C }
IPv6 Example 1:
Mark all ICMP echo traffic with packet mark 1. Mark all peer to peer traffic with packet mark 4.
This is a little more complex than otherwise expected. Since the ipp2p module is unable to determine
all packets in a connection are P2P packets, we mark the entire connection as P2P if any of the
packets are determined to match.
We assume packet/connection mark 0 means unclassified.
#ACTION SOURCE DEST PROTO DPORT SPORT USER TEST
MARK(1):T ::/0 ::/0 icmp echo-request
MARK(1):T ::/0 ::/0 icmp echo-reply
RESTORE:T ::/0 ::/0 all - - - 0
CONTINUE:T ::/0 ::/0 all - - - !0
MARK(4):T ::/0 ::/0 ipp2p:all
SAVE:T ::/0 ::/0 all - - - !0
If a packet hasn't been classified (packet mark is 0), copy the connection mark to the packet mark.
If the packet mark is set, we're done. If the packet is P2P, set the packet mark to 4. If the packet
mark has been set, save it to the connection mark.
FILES
/etc/shorewall/mangle
/etc/shorewall6/mangle
SEE ALSO
http://www.shorewall.net/traffic_shaping.htm[15]
http://www.shorewall.net/MultiISP.html[3]
http://www.shorewall.net/PacketMarking.html[16]
http://www.shorewall.net/configuration_file_basics.htm#Pairs[17]
shorewall(8)
NOTES
1. shorewall-tcrules(5)
http://www.shorewall.net/manpages/shorewall-tcrules.html
2. shorewall-rules
http://www.shorewall.net/manpages/shorewall-rules.html
3. http://www.shorewall.net/MultiISP.html
http://www.shorewall.net/MultiISP.html
4. shorewall.conf(5)
http://www.shorewall.net/manpages/shorewall.conf.html
5. shorewall-actions(5)
http://www.shorewall.netmanpages/shorewall-actions.html
6. shorewall-tcdevices
http://www.shorewall.net/manpages/shorewall-tcdevices.html
7. shorewall-tcclasses
http://www.shorewall.net/manpages/shorewall-tcclasses.html
8. shorewall-providers(5)
http://www.shorewall.net/manpages/shorewall-providers.html
9. shorewall-ecn(5)
http://www.shorewall.net/manpages/shorewall-ecn.html
10. shorewall-actions
http://www.shorewall.net/manpages/shorewall-actions.html
11. shorewall-interfaces
http://www.shorewall.net/manpages/shorewall-interfaces.html
12. shorewall-exclusion
http://www.shorewall.net/manpages/shorewall-exclusion.html
13. shorewall.conf
http://www.shorewall.net/manpages/shorewall.conf
14. http://www.shorewall.net/configuration_file_basics.htm#ICMP
http://www.shorewall.net/configuration_file_basics.htm#ICMP
15. http://www.shorewall.net/traffic_shaping.htm
http://www.shorewall.net/traffic_shaping.htm
16. http://www.shorewall.net/PacketMarking.html
http://www.shorewall.net/PacketMarking.html
17. http://www.shorewall.net/configuration_file_basics.htm#Pairs
http://www.shorewall.net/configuration_file_basics.htm#Pairs