input, output

On bidirectional interfaces, input and output will check the current direction of the interface. If the match is input but the interface is output the match will be reversed. The same will happen if output is given at the match and the interface is input.

The parameters that are reversed are:

•

src and dst

•

sport and dport

•

srcmac and dstmac

This allows a definition like this:

  interface dsl0 world bidirectional ...


    class surfing ...


      match input sport 0:1023
    

The above will match sport 0:1023 at the input interface, and will automatically reverse it to match dport 0:1023 at the output interface.

at

By default a match is attached to the parent of its parent class. For example, if its parent is a class directly under the interface, then the match is attached to the interface and is compared against all traffic of the interface. For nested classes, a match of a leaf, is attached to the parent class and is compared against all traffic of this parent class.

With the at parameter, a match can be attached any class. The name parameter should be a class name. The name root attaches the match to the interface.

class

Defines the name of the class that will get the packets matched by this match.

By default it is the name of the class the match statement appears under.

syn, syns

Match TCP SYN packets. Note that the tcp parameter must be specified.

If the same match statement includes more protocols than TCP, then this match will work for the TCP packets (it will be silently ignored for all other protocols).

For example, syn is ignored when generating the UDP filter in the below:

match tcp syn
match proto tcp,udp syn
    

ack, acks

Same as syn, but matching small TCP packets with the ACK bit set.

proto, protocol, tcp, udp, icmp, gre, ipv6

Match the protocol in the IP header.

tos, priority

Match to TOS field of ipv4 or the priority field of ipv6. The tosid can be a value/mask in any format tc(8) accepts, or one of the following:

•

min-delay, minimize-delay, minimum-delay, low-delay, interactive

•

maximize-throughput, maximum-throughput, max-throughput, high-throughput, bulk

•

maximize-reliability, maximum-reliability, max-reliability, reliable

•

min-cost, minimize-cost, minimum-cost, low-cost, cheap, normal-service, normal

dscp

Match to DSCP value in IP TOS header field. The classname has to be one of the following values:

•

CS1, CS2, CS3, CS4, CS5, CS6, CS7

•

AF11, AF12, AF13

•

AF21, AF22, AF23

•

AF31, AF32, AF33

•

AF41, AF42, AF43

•

EF

mark, connmark, custommark, rawmark

Match an iptables(8) MARK. This works the same way it works for FireHOL. FireHOL and FireQOS share the same marks and their masks.

Matching iptables(8) MARKs do not work on input interfaces. You can use them only on output. The IFB devices that are used for shaping inbound traffic do not have any iptables hooks to allow matching MARKs. If you try it, FireQOS will attempt to do it, but currently you will get an error from the tc(8) command executed or they will be silently ignored by it.

On some Linux distributions (e.g. OpenWRT) there is a module called act_commark that will enable this feature. Set this within your fireqos.conf to enable it:

FIREQOS_CONNMARK_RESTORE="act_connmark"
    

Also note that matching marks requires a suitably configured kernel (with CONFIG_CLS_U32_MARK=y). There is no error if the kernel is not configured correctly; it just silently drops the rules. For details see this error report (https://github.com/firehol/firehol/issues/231).

ports, sports, dports

Match ports of the IP header. ports will create rules for matching source and destination ports (separate rules for each). dports matches destination ports, sports matches source ports.

ip, net, host, src, dst

Match IPs of the IP header. ip, net and host will create rules for matching source and destination IPs (separate rules for each). src matches source IPs and dst destination IPs.

You can mix IPv4 and IPv6 in any way you like. FireQOS supports inheritance, to figure out for each statement which is the default. For example:

interface46 eth0 lan output rate 1Gbit # ipv4 and ipv6 enabled


  class voip # ipv4 and ipv6 class, as interface is both


    match udp port 53 # ipv4 and ipv6 rule, as class is both


    match4 src 192.0.2.1 # ipv4 only rule


    match6 src 2001:db8::1 # ipv6 only rule


  class4 realtime # ipv4 only class


    match src 198.51.100.1 # ipv4 only rule, as class is ipv4-only


  class6 servers # ipv6 only class


        match src 2001:db8::2 # ipv6 only rule, as class is ipv6-only
    

To convert an IPv4 interface to IPv6, just replace interface with interface6. All the rules in that interface, will automatically inherit the new protocol. Of course, if you use IP addresses for matching packets, make sure they are IPv6 IPs too.

prio (match)

All match statements are attached to the interface. They forward traffic to their class, but they are actually executed for all packets that are leaving the interface (note: input matches are actually output matches on an IFB device).

By default, the priority they are executed, is the priority they appear in the configuration file, i.e. the first match of the first class is executed first, then the rest matches of the first class in the sequence they appear, then the matches of the second class, etc.

It is sometimes necessary to control the order of matches. For example, when you want host 192.0.2.1 to be assigned the first class, except port tcp/1234 which should be assigned the second class. The following will not work:

interface eth0 lan output rate 1Gbit


  class high


    match host 192.0.2.1


  class low


    match host 192.0.2.1 port 1234 # Will never match
    

In this case, the first match is assigned priority 10 and the second priority 20. The second match will never match anything, since all traffic for the host is already matched by the first one.

Setting an explicit priority allows you to change the order in which the matches are executed. FireQOS gives priority 10 to the first match of every interface, 20 to the second match, 30 to the third match, etc. So the default is 10 x the sequence number. You can set prio to overwrite this number.

To force executing the second match before the first, just set a lower priority for it. For example, this will cause the desired behaviour:

interface eth0 lan output rate 1Gbit


  class high


    match host 192.0.2.1


  class low


    match host 192.0.2.1 port 1234 prio 1 # Matches before host-only
    

insidegre

By specifying keyword insidegre a GRE (Generic Routing Encapsulation) packet can be matched on the encapsulated IP packet header information.

insidegre is available for the following matches:

•

src

•

dst

•

protocol

•

port

•

tos

•

dscp

  interface eth0 world ...


    class surfing commit 128kbit ceil 1024kbit prio 7


      match src 10.1.128.230 dst 8.8.8.8 insidegre


      match protocol ospf insidegre


      match port 25 insidegre


      match tos 3 insidegre


      match dscp ef insidegre