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diff --git a/doc/bird.sgml b/doc/bird.sgml index a734b2ff..999fa294 100644 --- a/doc/bird.sgml +++ b/doc/bird.sgml @@ -715,6 +715,137 @@ agreement"). </descrip> + +<sect>Flowspec network type +<label id="flowspec-network-type"> + +<p>The flow specification are rules for routers and firewalls for filtering +purpose. It is described by <rfc id="5575">. There are 3 types of arguments: +<m/inet4/ or <m/inet6/ prefixes, bitmasks matching expressions and numbers +matching expressions. + +Bitmasks matching is written using <m/value/<cf>/</cf><m/mask/ or +<cf/!/<m/value/<cf>/</cf><m/mask/ pairs. It means that <cf/(/<m/data/ <cf/&/ +<m/mask/<cf/)/ is or is not equal to <m/value/. + +Numbers matching is a matching sequence of numbers and ranges separeted by a +commas (<cf/,/) (e.g. <cf/10,20,30/). Ranges can be written using double dots +<cf/../ notation (e.g. <cf/80..90,120..124/). An alternative notation are +sequence of one or more pairs of relational operators and values separated by +logical operators <cf/&&/ or <cf/||/. Allowed relational operators are <cf/=/, +<cf/!=/, <cf/</, <cf/<=/, <cf/>/, <cf/>=/, <cf/true/ and <cf/false/. + +<sect1>IPv4 Flowspec + +<p><descrip> + <tag><label id="flow-dst">dst <m/inet4/</tag> + Set a matching destination prefix (e.g. <cf>dst 192.168.0.0/16</cf>). + Only this option is mandatory in IPv4 Flowspec. + + <tag><label id="flow-src">src <m/inet4/</tag> + Set a matching source prefix (e.g. <cf>src 10.0.0.0/8</cf>). + + <tag><label id="flow-proto">proto <m/numbers-match/</tag> + Set a matching IP protocol numbers (e.g. <cf/proto 6/). + + <tag><label id="flow-port">port <m/numbers-match/</tag> + Set a matching source or destination TCP/UDP port numbers (e.g. + <cf>port 1..1023,1194,3306</cf>). + + <tag><label id="flow-dport">dport <m/numbers-match/</tag> + Set a mating destination port numbers (e.g. <cf>dport 49151</cf>). + + <tag><label id="flow-sport">sport <m/numbers-match/</tag> + Set a matching source port numbers (e.g. <cf>sport = 0</cf>). + + <tag><label id="flow-icmp-type">icmp type <m/numbers-match/</tag> + Set a matching type field number of an ICMP packet (e.g. <cf>icmp type + 3</cf>) + + <tag><label id="flow-icmp-code">icmp code <m/numbers-match/</tag> + Set a matching code field number of an ICMP packet (e.g. <cf>icmp code + 1</cf>) + + <tag><label id="flow-tcp-flags">tcp flags <m/bitmask-match/</tag> + Set a matching bitmask for TCP header flags (aka control bits) (e.g. + <cf>tcp flags 0x03/0x0f;</cf>). + + <tag><label id="flow-length">length <m/numbers-match/</tag> + Set a matching packet length (e.g. <cf>length > 1500;</cf>) + + <tag><label id="flow-dscp">dscp <m/numbers-match/</tag> + Set a matching DiffServ Code Point number (e.g. <cf>length > 1500;</cf>). + + <tag><label id="flow-fragment">fragment <m/fragmentation-type/</tag> + Set a matching type of packet fragmentation. Allowed fragmentation + types are <cf/dont_fragment/, <cf/is_fragment/, <cf/first_fragment/, + <cf/last_fragment/ (e.g. <cf>fragment is_fragment && + !dont_fragment</cf>). +</descrip> + +<p><code> +protocol static { + flow4; + + route flow4 { + dst 10.0.0.0/8; + port > 24 && < 30 || 40..50,60..70,80 && >= 90; + tcp flags 0x03/0x0f; + length > 1024; + dscp = 63; + fragment dont_fragment, is_fragment || !first_fragment; + } drop; +} +</code> + +<sect1>Differences for IPv6 Flowspec + +<p>Flowspec IPv6 are same as Flowspec IPv4 with a few exceptions. +<itemize> + <item>Prefixes <m/inet6/ can be specified not only with prefix length, + but with prefix <cf/offset/ <m/num/ too (e.g. + <cf>::1234:5678:9800:0000/101 offset 64</cf>). Offset means to don't + care of <m/num/ first bits. + <item>IPv6 Flowspec hasn't mandatory any flowspec component. + <item>In IPv6 packets, there is a matching the last next header value + for a matching IP protocol number (e.g. <cf>next header 6</cf>). + <item>It is not possible to set <cf>dont_fragment</cf> as a type of + packet fragmentation. +</itemize> + +<p><descrip> + <tag><label id="flow6-dst">dst <m/inet6/ [offset <m/num/]</tag> + Set a matching destination IPv6 prefix (e.g. <cf>dst + ::1c77:3769:27ad:a11a/128 offset 64</cf>). + + <tag><label id="flow6-src">src <m/inet6/ [offset <m/num/]</tag> + Set a matching source IPv6 prefix (e.g. <cf>src fe80::/64</cf>). + + <tag><label id="flow6-next-header">next header <m/numbers-match/</tag> + Set a matching IP protocol numbers (e.g. <cf>next header != 6</cf>). + + <tag><label id="flow6-label">label <m/bitmask-match/</tag> + Set a 20-bit bitmask for matching Flow Label field in IPv6 packets + (e.g. <cf>label 0x8e5/0x8e5</cf>). +</descrip> + +<p><code> +protocol static { + flow6; + + route flow6 { + dst fec0:1122:3344:5566:7788:99aa:bbcc:ddee/128; + src 0000:0000:0000:0001:1234:5678:9800:0000/101 offset 63; + next header = 23; + sport > 24 && < 30 || = 40 || 50,60,70..80; + dport = 50; + tcp flags 0x03/0x0f, !0/0xff || 0x33/0x33; + fragment !is_fragment || !first_fragment; + label 0xaaaa/0xaaaa && 0x33/0x33; + } drop; +} +</code> + <chapt>Remote control <label id="remote-control"> |