SHOREWALL-TCRULES(5)SHOREWALL-TCRULES(5)NAME
tcrules - Shorewall Packet Marking rules file
SYNOPSIS
/etc/shorewall/rules
DESCRIPTION
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[1](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://shorewall.net/MultiISP.html.
The columns in the file are as follows.
MARK/CLASSIFY -
{value|major:minor|RESTORE[/mask]|SAVE[/mask]|CONTINUE|SAME|COMMENT|IPMARK[([(src|dst}][,[mask1][,[mask2][,[shift]]]]])]}[:{C|F|P|T|CF|CP|CT}]
May assume one of the following values.
1. A mark value which is an integer in the range 1-255.
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; neither may be used with connection marks
(see below).
May optionally be followed by :P, :F or :T where :P indicates
that marking should occur in the PREROUTING chain, :F indicates
that marking should occur in the FORWARD chain and :T indicates
that marking should occur in the POSTROUTING chain. If neither
:P, :F nor :T follow the mark value then the chain is
determined as follows:
- If the SOURCE is
$FW[:address-or-range[,address-or-range]...], then the rule is
inserted into the OUTPUT chain. When HIGH_ROUTE_MARKS=Yes, only
high mark values may be assigned there. Packet marking rules
for traffic shaping of packets originating on the firewall must
be coded in the POSTROUTING chain (see below).
- Otherwise, the chain is determined by the setting of
MARK_IN_FORWARD_CHAIN in shorewall.conf[2](5).
If your kernel and iptables include CONNMARK support then you
can also mark the connection rather than the packet.
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). The mark and optional mask are then followed
by one of:+
C
Mark the connection in the chain determined by the setting
of MARK_IN_FORWARD_CHAIN
CF
Mark the connection in the FORWARD chain
CP
Mark the connection in the PREROUTING chain.
CT
Mark the connecdtion in the POSTROUTING chain
Special considerations for If HIGH_ROUTE_MARKS=Yes in
shorewall.conf[2](5).
If HIGH_ROUTE_MARKS=Yes, then you may also specify a value in
the range 0x0100-0xFF00 with the low-order byte being zero.
Such values may only be used in the PREROUTING chain (value
followed by :P or you have set MARK_IN_FORWARD_CHAIN=No in
shorewall.conf[2](5) and have not followed the value with :F)
or the OUTPUT chain (SOURCE is $FW). With HIGH_ROUTE_MARKS=Yes,
non-zero mark values less that 256 are not permitted. Shorewall
prohibits non-zero mark values less that 256 in the OUTPUT
chain when HIGH_ROUTE_MARKS=Yes. While earlier versions allow
such values in the OUTPUT chain, it is strongly recommended
that with HIGH_ROUTE_MARKS=Yes, you use the POSTROUTING chain
to apply traffic shaping marks/classification.
2. A classification Id (classid) 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[3](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[4](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.).
3. 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.
As in 1) above, may be followed by :P or :F
4. 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.
As in 1) above, may be followed by :P or :F
5. CONTINUE Don´t process any more marking rules –in the table.
As in 1) above, may be followed by :P or :F. 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.
6. SAME 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:
#MARK/ SOURCE DEST PROTO DEST
#CLASSIFY PORT(S)
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:
#MARK/ SOURCE DEST PROTO DEST
#CLASSIFY PORT(S)
SAME $FW 0.0.0.0/0 tcp 80,443
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 five
minutes to the same remote system then the new connection will
use the same provider as the connection over which that last
packet was sent.
7. 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.
8. 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 0x0x10100 = 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 chose instent to
use IPMARK(src,0xFF,0x10100) as in the example above so
that all of your minor classes will have a value > 256.
SOURCE -
{-|{interface|$FW}|[{interface|$FW}:]address-or-range[,address-or-range]...}[exclusion]
May be:
1. An interface name - matches traffic entering the firewall on
the specified interface. May not be used in classify rules or
in rules using the :T chain qualifier.
2. A comma-separated list of host or network IP addresses or MAC
addresses. 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 MARK column.
Examples:.IP "" 4 0.0.0.0/0
192.168.1.0/24, 172.20.4.0/24
3. An interface name followed by a colon (":") followed by a
comma-separated list of host or network IP addresses or MAC
addresses. May not be used in classify rules or in rules using
the :T chain qualifier.
4. $FW optionally followed by a colon (":") and a comma-separated
list of host or network IP addresses. Matches packets
originating on the firewall. May not be used with a chain
qualifier (:P, :F, etc.) in the MARK column.
MAC addresses must be prefixed with "~" and use "-" as a
separator.
Example: ~00-A0-C9-15-39-78
You may exclude certain hosts from the set already defined
through use of an exclusion (see shorewall-exclusion[5](5)).
DEST -
{-|{interface|[interface:]address-or-range[,address-or-range]...}[exclusion]
May be:
1. An interface name. 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[6] (5)). The
interface name may be optionally followed by a colon (":") and
an IP address list.
2. A comma-separated list of host or network IP addresses. The
list may include ip address ranges if your kernel and iptables
include iprange support.
You may exclude certain hosts from the set already defined
through use of an exclusion (see shorewall-exclusion[5](5)).
PROTO -
{-|tcp:syn|ipp2p|ipp2p:udp|ipp2p:all|protocol-number|protocol-name|all}
Protocol - ipp2p requires ipp2p match support in your kernel and
iptables.
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). ICMP
types may be specified as a numeric type, a numberic type and code
separated by a slash (e.g., 3/4), or a typename. See
http://www.shorewall.net/configuration_file_basics.htm#ICMP.
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.
This column is ignored if PROTOCOL = all but must be entered if any
of the following field is supplied. In that case, it is suggested
that this field contain "-"
SOURCE PORT(S) (Optional) -
[-|port-name-number-or-range[,port-name-number-or-range]...]
Source port(s). If omitted, any source port is acceptable.
Specified as a comma-separated list of port names, port numbers or
port ranges.
USER (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.
TEST - [!]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.
LENGTH (Optional) - [length|[min]:[max]]
Packet Length. This field, if present allow you to match the length
of a packet 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}]]]
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 Netfiler protocol helper module such as ftp, sip, amanda,
etc. A packet will match if it was accepted by the named helper
module. You can also append "-" and a port number to the helper
module name (e.g., ftp-21) to specify the port number that the
original connection was made on.
Example: Mark all FTP data connections with mark 4:
#MARK/ SOURCE DEST PROTO PORT(S) SOURCE USER TEST LENGTH TOS CONNBYTES HELPER
#CLASSIFY PORT(S)
4:T 0.0.0.0/0 0.0.0.0/0 TCP - - - - - - - ftp
EXAMPLE
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.
#MARK/ SOURCE DEST PROTO PORT(S) SOURCE USER TEST
#CLASSIFY PORT(S)
1:T 0.0.0.0/0 0.0.0.0/0 icmp echo-request
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
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 classifed (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/tcrules
SEE ALSO
http://shorewall.net/traffic_shaping.htm
http://shorewall.net/MultiISP.html
http://shorewall.net/PacketMarking.html
shorewall(8), shorewall-accounting(5), shorewall-actions(5),
shorewall-blacklist(5), shorewall-ecn(5), shorewall-exclusion(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_rules(5), shorewall-routestopped(5),
shorewall-rules(5), shorewall.conf(5), shorewall-tcclasses(5),
shorewall-tcdevices(5), shorewall-tos(5), shorewall-tunnels(5),
shorewall-zones(5)NOTES
1. shorewall-rules
shorewall-rules.html
2. shorewall.conf
shorewall.conf.html
3. shorewall-tcdevices
shorewall-tcdevices.html
4. shorewall-tcclasses
shorewall-tcclasses.html
5. shorewall-exclusion
shorewall-exclusion.html
6. shorewall.conf
manpages/shorewall.conf
05/07/2010 SHOREWALL-TCRULES(5)
