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* src: implement add/create/delete for ct helper objectsFlorian Westphal2017-03-161-2/+61
| | | | | Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: allow listing all ct helpersFlorian Westphal2017-03-161-0/+19
| | | | | | | | | | | this implements nft list ct helpers table filter table ip filter { ct helper ftp-standard { .. Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: add initial ct helper supportFlorian Westphal2017-03-161-2/+72
| | | | | | | | | | | | | | | | | This adds initial support for defining conntrack helper objects which can then be assigned to connections using the objref infrastructure: table ip filter { ct helper ftp-standard { type "ftp" protocol tcp } chain y { tcp dport 21 ct helper set "ftp-standard" } } Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
* exthdr: Implement existence checkPhil Sutter2017-03-101-0/+34
| | | | | | | | | | | This allows to check for existence of an IPv6 extension or TCP option header by using the following syntax: | exthdr frag exists | tcpopt window exists Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* Introduce boolean datatype and boolean expressionPhil Sutter2017-03-101-0/+20
| | | | | Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: hash: support of symmetric hashLaura Garcia Liebana2017-03-061-6/+10
| | | | | | | | | | | | | | | | | | | | | This patch provides symmetric hash support according to source ip address and port, and destination ip address and port. The new attribute NFTA_HASH_TYPE has been included to support different types of hashing functions. Currently supported NFT_HASH_JENKINS through jhash and NFT_HASH_SYM through symhash. The main difference between both types are: - jhash requires an expression with sreg, symhash doesn't. - symhash supports modulus and offset, but not seed. Examples: nft add rule ip nat prerouting ct mark set jhash ip saddr mod 2 nft add rule ip nat prerouting ct mark set symhash mod 2 Signed-off-by: Laura Garcia Liebana <laura.garcia@zevenet.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: revisit tcp options supportPablo Neira Ayuso2017-02-281-33/+48
| | | | | | | | | | | | | | | | | | | Rework syntax, add tokens so we can extend the grammar more easily. This has triggered several syntax changes with regards to the original patch, specifically: tcp option sack0 left 1 There is no space between sack and the block number anymore, no more offset field, now they are a single field. Just like we do with rt, rt0 and rt2. This simplifies our grammar and that is good since it makes our life easier when extending it later on to accomodate new features. I have also renamed sack_permitted to sack-permitted. I couldn't find any option using underscore so far, so let's keep it consistent with what we have. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: support zone set statement with optional directionFlorian Westphal2017-02-281-2/+15
| | | | | | | | | | | | nft automatically understands 'ct zone set 1' but when a direction is specified too we get a parser error since they are currently only allowed for plain ct expressions. This permits the existing syntax ('ct original zone') for all tokens with an optional direction also for set statements. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: add conntrack zone supportFlorian Westphal2017-02-281-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This enables zone get/set support. As the zone can be optionally tied to a direction as well we need a new token for this (unless we turn reply/original into tokens in which case we could handle zone via STRING). There was some discussion on how zone set support should be handled, especially 'zone set 1'. There are several issues to consider: 1. its not possible to change a zone 'later on', any given conntrack flow has exactly one zone for its entire lifetime. 2. to create conntracks in a given zone, the zone therefore has to be assigned *before* the packet gets picked up by conntrack (so that lookup finds the correct existing flow or the flow is created with the desired zone id). In iptables, this is enforced because zones are assigned with CT target and this is restricted to the 'raw' table in iptables, which runs after defragmentation but before connection tracking. 3. Thus, in nftables the 'ct zone set' rule needs to hook before conntrack too, e.g. via table raw { chain pre { type filter hook prerouting priority -300; iif eth3 ct zone set 23 } chain out { type filter hook output priority -300; oif eth3 ct zone set 23 } } ... but this is not enforced. There were two alternatives to better document this. One was to use an explicit 'template' keyword: nft ... template zone set 23 ... but 'connection tracking templates' are a kernel detail that users should not and need not know about. The other one was to use the meta keyword instead since we're (from a practical point of view) assigning the zone to the packet, not the conntrack: nft ... meta zone set 23 However, next patch also supports 'directional' zones, and nft ... meta original zone 23 makes no sense because 'direction' refers to a direction as understood by the connection tracker. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: add TCP option matchingManuel Messner2017-02-121-5/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch enables nft to match against TCP options. Currently these TCP options are supported: * End of Option List (eol) * No-Operation (noop) * Maximum Segment Size (maxseg) * Window Scale (window) * SACK Permitted (sack_permitted) * SACK (sack) * Timestamps (timestamp) Syntax: tcp options $option_name [$offset] $field_name Example: # count all incoming packets with a specific maximum segment size `x` # nft add rule filter input tcp option maxseg size x counter # count all incoming packets with a SACK TCP option where the third # (counted from zero) left field is greater `x`. # nft add rule filter input tcp option sack 2 left \> x counter If the offset (the `2` in the example above) is zero, it can optionally be omitted. For all non-SACK TCP options it is always zero, thus can be left out. Option names and field names are parsed from templates, similar to meta and ct options rather than via keywords to prevent adding more keywords than necessary. Signed-off-by: Manuel Messner <mm@skelett.io> Signed-off-by: Florian Westphal <fw@strlen.de>
* src: Allow list stateful objects in a tableElise Lennion2017-01-271-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, stateful objects can be listed by: listing all objects in all tables; listing a single object in a table. Now it's allowed to list all objects in a table. $ nft list counters table filter table ip filter { counter https-traffic { packets 14825 bytes 950063 } counter http-traffic { packets 117 bytes 9340 } } $ nft list quotas table filter table ip filter { quota https-quota { 25 mbytes used 2 mbytes } quota http-quota { 25 mbytes used 10 kbytes } } Signed-off-by: Elise Lennion <elise.lennion@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: Allow reset single stateful objectElise Lennion2017-01-271-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | Currently the stateful objects can only be reseted in groups. With this patch reseting a single object is allowed: $ nft reset counter filter https-traffic table ip filter { counter https-traffic { packets 8774 bytes 542668 } } $ nft list counter filter https-traffic table ip filter { counter https-traffic { packets 0 bytes 0 } } Heavily based on work from Pablo Neira Ayuso <pablo@netfilter.org>. Signed-off-by: Elise Lennion <elise.lennion@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* ct: add average bytes per packet counter supportLiping Zhang2017-01-161-0/+2
| | | | | | | | | | | | | | | | | Similar to connbytes extension in iptables, now you can use it to match average bytes per packet a connection has transferred so far. For example, match avgpkt in "BOTH" diretion: # nft add rule x y ct avgpkt \> 100 Match avgpkt in reply direction: # nft add rule x y ct reply avgpkt \< 900 Or match avgpkt in original direction: # nft add rule x y ct original avgpkt \> 200 Signed-off-by: Liping Zhang <zlpnobody@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* parser_bison: remove obsolete tokensFlorian Westphal2017-01-081-6/+0
| | | | | | removed in c992153402c78d91e8be ("ct: allow resolving ct keys at run time"). Signed-off-by: Florian Westphal <fw@strlen.de>
* src: add support for stateful object mapsPablo Neira Ayuso2017-01-031-1/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | You can create these maps using explicit map declarations: # nft add table filter # nft add chain filter input { type filter hook input priority 0\; } # nft add map filter badguys { type ipv4_addr : counter \; } # nft add rule filter input counter name ip saddr map @badguys # nft add counter filter badguy1 # nft add counter filter badguy2 # nft add element filter badguys { 192.168.2.3 : "badguy1" } # nft add element filter badguys { 192.168.2.4 : "badguy2" } Or through implicit map definitions: table ip filter { counter http-traffic { packets 8 bytes 672 } chain input { type filter hook input priority 0; policy accept; counter name tcp dport map { 80 : "http-traffic", 443 : "http-traffic"} } } Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: add stateful object reference expressionPablo Neira Ayuso2017-01-031-0/+13
| | | | | | | | | This patch adds a new objref statement to refer to existing stateful objects from rules, eg. # nft add rule filter input counter name test counter Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* parser_bison: allow RESET token from rhsPablo Neira Ayuso2017-01-031-8/+8
| | | | | | | | | | Stateful objects have introduced a RESET token in the parser. This breaks the use of RESET from the rhs, to fix this: 1) I added a new rule to catch this case, thus, dccp doesn't break. 2) Update reject_opts so reject with tcp reset still works. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: reset internal stateful objectsPablo Neira Ayuso2017-01-031-2/+22
| | | | | | | | | | | | | | | | | | | | | This patch allows you to atomically dump and reset stateful objects, eg. # nft list counters table ip filter { counter test { packets 1024 bytes 100000 } } # nft reset quotas table filter counter test { packets 1024 bytes 100000 } # nft reset quotas table filter counter test { packets 0 bytes 0 } Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: add/create/delete stateful objectsPablo Neira Ayuso2017-01-031-2/+159
| | | | | | | | | | | | | | | | This patch allows you to add and to delete objects, eg. # nft add quota filter test 1234567 bytes # nft list quotas table ip filter { quota test { 1234567 bytes } } # nft delete quota filter test Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: listing of stateful objectsPablo Neira Ayuso2017-01-031-2/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch allows you to dump existing stateful objects, eg. # nft list ruleset table ip filter { counter test { packets 64 bytes 1268 } quota test { over 1 mbytes used 1268 bytes } chain input { type filter hook input priority 0; policy accept; quota name test drop counter name test } } # nft list quotas table ip filter { quota test { over 1 mbytes used 1268 bytes } } # nft list counters table ip filter { counter test { packets 64 bytes 1268 } } Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: add used quota supportPablo Neira Ayuso2017-01-031-2/+19
| | | | | | | | | | | | | table ip x { chain y { type filter hook forward priority 0; policy accept; quota over 200 mbytes used 1143 kbytes drop } } This patch allows us to list and to restore used quota. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: remove SET_F_* flag definitionsPablo Neira Ayuso2017-01-031-3/+3
| | | | | | | They map exactly one to one to we have in the kernel headers, so use kernel definitions instead. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* bison: remove old log level tokensFlorian Westphal2016-11-301-8/+0
| | | | | | | not used anymore since 0423caa91ad26e7 ("src: don't need keyword for log level") Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
* parser_bison: Allow parens on RHS of relational_exprPhil Sutter2016-11-291-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is useful to allow a construct such as: | tcp flags & (syn|fin) == (syn|fin) Before, only the parentheses on the left side were allowed, but via a quite funny path through the parser: * expr might be a concat_expr * concat_expr might be a basic_expr * basic_expr is an inclusive_or_expr * inclusive_or_expr might be an exclusive_or_expr * exclusive_or_expr might be an and_expr * and_expr might be 'and_expr AMPERSAND shift_expr' -> here we eliminate 'flags &' in above statement * shift_expr might be a primary_expr * primary_expr might be '( basic_expr )' Commit a3e60492a684b ("parser: restrict relational rhs expression recursion") introduced rhs_expr to disallow recursion on RHS, so just reverting that change for relational_expr is a no go. Allowing rhs_expr to be '( rhs_expr )' though seems way too intrusive to me since it's being used in all kinds of places, so this patch is the safest way to allow the above I could come up with. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: add log flags syntax supportLiping Zhang2016-11-241-1/+49
| | | | | | | | | | | | | | | | | | | | | Now NF_LOG_XXX is exposed to the userspace, we can set it explicitly. Like iptables LOG target, we can log TCP sequence numbers, TCP options, IP options, UID owning local socket and decode MAC header. Note the log flags are mutually exclusive with group. Some examples are listed below: # nft add rule t c log flags tcp sequence,options # nft add rule t c log flags ip options # nft add rule t c log flags skuid # nft add rule t c log flags ether # nft add rule t c log flags all # nft add rule t c log flags all group 1 <cmdline>:1:14-16: Error: flags and group are mutually exclusive add rule t c log flags all group 1 ^^^ Signed-off-by: Liping Zhang <zlpnobody@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: add notrack supportPablo Neira Ayuso2016-11-141-0/+6
| | | | | | | This patch adds the notrack statement, to skip connection tracking for certain packets. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: add offset attribute for hash expressionLaura Garcia Liebana2016-11-091-4/+4
| | | | | | | | | | | Add support to add an offset to the hash generator, eg. ct mark set hash ip saddr mod 10 offset 100 This will generate marks with series between 100-109. Signed-off-by: Laura Garcia Liebana <nevola@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: make hash seed attribute optionalLaura Garcia Liebana2016-11-091-0/+5
| | | | | | | | | | | | | | | | | | The hash expression requires a seed attribute to call the jhash operation, eg. # nft add rule x y meta mark set jhash ip saddr . ip daddr mod 2 \ seed 0xdeadbeef With this patch the seed attribute is optional and it's generated by a random function from userspace, eg. # nft add rule x y meta mark set jhash ip saddr . ip daddr mod 2 The kernel will take care of generate a random seed. Signed-off-by: Laura Garcia Liebana <nevola@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* log: rename the log level "warning" to "warn"Liping Zhang2016-10-311-1/+1
| | | | | | | | | This is to keep compatibility. The original keyword in grammer is "warn" instead of "warning". Fixes: 0423caa91ad2 ("src: don't need keyword for log level") Signed-off-by: Liping Zhang <zlpnobody@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* ct: fix "ct l3proto/protocol" syntax brokenLiping Zhang2016-10-301-1/+3
| | | | | | | | | | | | | | | "l3proto" and "protocol" are still keywords in our grammer, they are not STRING, so if the user input the following rule, nft will complain that the syntax is error: # nft add t c ct l3proto ipv4 <cmdline>:1:12-18: Error: syntax error, unexpected l3proto, expecting string or mark or packets or bytes add t c ct l3proto ipv4 ^^^^^^^ Fixes: c992153402c7 ("ct: allow resolving ct keys at run time") Signed-off-by: Liping Zhang <zlpnobody@gmail.com> Signed-off-by: Florian Westphal <fw@strlen.de>
* src: add fib expressionFlorian Westphal2016-10-281-0/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds the 'fib' expression which can be used to obtain the output interface from the route table based on either source or destination address of a packet. This can be used to e.g. add reverse path filtering: # drop if not coming from the same interface packet # arrived on # nft add rule x prerouting fib saddr . iif oif eq 0 drop # accept only if from eth0 # nft add rule x prerouting fib saddr . iif oif eq "eth0" accept # accept if from any valid interface # nft add rule x prerouting fib saddr oif accept Querying of address type is also supported. This can be used to e.g. only accept packets to addresses configured in the same interface: # fib daddr . iif type local Its also possible to use mark and verdict map, e.g.: # nft add rule x prerouting meta mark set 0xdead fib daddr . mark type vmap { blackhole : drop, prohibit : drop, unicast : accept } Signed-off-by: Florian Westphal <fw@strlen.de>
* rt: introduce routing expressionAnders K. Pedersen2016-10-281-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce rt expression for routing related data with support for nexthop (i.e. the directly connected IP address that an outgoing packet is sent to), which can be used either for matching or accounting, eg. # nft add rule filter postrouting \ ip daddr 192.168.1.0/24 rt nexthop != 192.168.0.1 drop This will drop any traffic to 192.168.1.0/24 that is not routed via 192.168.0.1. # nft add rule filter postrouting \ flow table acct { rt nexthop timeout 600s counter } # nft add rule ip6 filter postrouting \ flow table acct { rt nexthop timeout 600s counter } These rules count outgoing traffic per nexthop. Note that the timeout releases an entry if no traffic is seen for this nexthop within 10 minutes. # nft add rule inet filter postrouting \ ether type ip \ flow table acct { rt nexthop timeout 600s counter } # nft add rule inet filter postrouting \ ether type ip6 \ flow table acct { rt nexthop timeout 600s counter } Same as above, but via the inet family, where the ether type must be specified explicitly. "rt classid" is also implemented identical to "meta rtclassid", since it is more logical to have this match in the routing expression going forward. Signed-off-by: Anders K. Pedersen <akp@cohaesio.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* meta: allow resolving meta keys at run timeFlorian Westphal2016-10-271-5/+26
| | | | | | | | | use the meta template to translate the textual token to the enum value. This allows to remove two keywords from the scanner and also means we do not need to introduce new keywords when more meta keys get added. Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
* ct: allow resolving ct keys at run timeFlorian Westphal2016-10-271-9/+27
| | | | | | | ... and remove those keywords we no longer need. Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
* parser: add offset keyword and parser rulePablo Neira Ayuso2016-10-271-1/+6
| | | | | | This is required by the numgen and jhash expressions. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: add offset attribute for numgen expressionLaura Garcia Liebana2016-10-271-2/+2
| | | | | | | | | | | | | Add support to add an offset to the numgen generated value. Example: ct mark set numgen inc mod 2 offset 100 This will generate marks with serie like 100, 101, 100, ... Signed-off-by: Laura Garcia Liebana <nevola@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: don't need keyword for log levelPablo Neira Ayuso2016-10-211-8/+24
| | | | | | | We can handle log levels without keywords in our grammar, use string instead. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* parser_bison: allow to use variable to add/create/delete elementsPablo Neira Ayuso2016-10-211-3/+3
| | | | | | | | | | | | | | | | | | | | | | | Using variable definitions from element command doesn't work, eg. -test.nft- define whitelist_v4 = { 1.1.1.1 } table inet filter { set whitelist_v4 { type ipv4_addr; } } add element inet filter whitelist_v4 $whitelist_v4 -EOF- # nft -f test.nft test.nft:7:38-38: Error: syntax error, unexpected '$', expecting '{' add element inet filter whitelist_v4 $whitelist_v4 ^ Fix this by using set_block_expr rule for every element command. This patch also comes with a new regression test. Reported-by: Leon Merten Lohse <leon@green-side.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: support ct l3proto/protocol without direction syntaxLiping Zhang2016-10-171-0/+2
| | | | | | | | | | | | | | | Acctually, ct l3proto and ct protocol are unrelated to direction, so it's unnecessary that we must specify dir if we want to use them. Now add support that we can match ct l3proto/protocol without direction: # nft add rule filter input ct l3proto ipv4 # nft add rule filter output ct protocol 17 Note: existing syntax is still preserved, so "ct reply l3proto ipv6" is still fine. Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* parser_bison: allow variable references in set elements definitionPablo Neira Ayuso2016-08-291-4/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Andreas reports that he cannot use variables in set definitions: define s-ext-2-int = 10.10.10.10 . 25, 10.10.10.10 . 143 set s-ext-2-int { type ipv4_addr . inet_service elements = { $s-ext-2-int } } This syntax is not correct though, since the curly braces should be placed in the variable definition itself, so we have context to handle this variable as a list of set elements. The correct syntax that works after this patch is: define s-ext-2-int = { 10.10.10.10 . 25, 10.10.10.10 . 143 } table inet forward { set s-ext-2-int { type ipv4_addr . inet_service elements = $s-ext-2-int } } Reported-by: Andreas Hainke <andreas.hainke@foteviken.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* parser_bison: add variable_expr rulePablo Neira Ayuso2016-08-291-10/+13
| | | | | | | This patch adds a rule for variable expression so we can reuse it in a follow up patch to allow set element initialization from variable. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: add hash expressionPablo Neira Ayuso2016-08-291-2/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This is special expression that transforms an input expression into a 32-bit unsigned integer. This expression takes a modulus parameter to scale the result and the random seed so the hash result becomes harder to predict. You can use it to set the packet mark, eg. # nft add rule x y meta mark set jhash ip saddr . ip daddr mod 2 seed 0xdeadbeef You can combine this with maps too, eg. # nft add rule x y dnat to jhash ip saddr mod 2 seed 0xdeadbeef map { \ 0 : 192.168.20.100, \ 1 : 192.168.30.100 \ } Currently, this expression implements the jenkins hash implementation available in the Linux kernel: http://lxr.free-electrons.com/source/include/linux/jhash.h But it should be possible to extend it to support any other hash function type. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: add numgen expressionPablo Neira Ayuso2016-08-291-3/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This new expression allows us to generate incremental and random numbers bound to a specified modulus value. The following rule sets the conntrack mark of 0 to the first packet seen, then 1 to second packet, then 0 again to the third packet and so on: # nft add rule x y ct mark set numgen inc mod 2 A more useful example is a simple load balancing scenario, where you can also use maps to set the destination NAT address based on this new numgen expression: # nft add rule nat prerouting \ dnat to numgen inc mod 2 map { 0 : 192.168.10.100, 1 : 192.168.20.200 } So this is distributing new connections in a round-robin fashion between 192.168.10.100 and 192.168.20.200. Don't forget the special NAT chain semantics: Only the first packet evaluates the rule, follow up packets rely on conntrack to apply the NAT information. You can also emulate flow distribution with different backend weights using intervals: # nft add rule nat prerouting \ dnat to numgen inc mod 10 map { 0-5 : 192.168.10.100, 6-9 : 192.168.20.200 } So 192.168.10.100 gets 60% of the workload, while 192.168.20.200 gets 40%. We can also be mixed with dynamic sets, thus weight can be updated in runtime. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: add quota statementPablo Neira Ayuso2016-08-291-5/+33
| | | | | | | | | | | | | This new statement is stateful, so it can be used from flow tables, eg. # nft add rule filter input \ flow table http { ip saddr timeout 60s quota over 50 mbytes } drop This basically sets a quota per source IP address of 50 mbytes after which packets are dropped. Note that the timeout releases the entry if no traffic is seen from this IP after 60 seconds. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: create element commandPablo Neira Ayuso2016-08-251-0/+4
| | | | | | | | | | | | | | | This patch adds the create command, that send the NLM_F_EXCL flag so nf_tables bails out if the element already exists, eg. # nft add element x y { 1.1.1.1 } # nft create element x y { 1.1.1.1 } <cmdline>:1:1-31: Error: Could not process rule: File exists create element x y { 1.1.1.1 } ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ This update requires nf_tables kernel patches to honor the NLM_F_EXCL. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: add create set commandPablo Neira Ayuso2016-08-241-0/+14
| | | | | | | | | | | | | | | | | | | | | | Add support for the 'create' command, we already support this in other existing objects, so support this for sets too, eg. # nft add set x y { type ipv4_addr\; } # nft create set x y { type ipv4_addr\; } <cmdline>:1:1-35: Error: Could not process rule: File exists create set x y { type ipv4_addr; } ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ # nft add set x y { type ipv4_addr\; } # This command sets the NLM_F_EXCL netlink flag, so if the object already exists, nf_tables returns -EEXIST. This is changing the existing behaviour of 'nft add set' which was setting this flag, this is inconsistent with regards to the way other objects behave. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* parser_bison: explicit indication on export rulesetPablo Neira Ayuso2016-08-231-1/+7
| | | | | | | | | | | | | | | This patch modifies the grammar to explicitly indicate what you want to export, eg. # nft export ruleset json This leaves room to extend this later on to support other object types, such as integrating conntrack into nft. This also leaves the syntax in consistent state wrt. other existing objects. The existing syntax is still preserved. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: Simplify parser rule_spec treeCarlos Falgueras García2016-08-231-22/+21
| | | | | | | | | | This patch separates the rule identification from the rule localization, so the logic moves from the evaluator to the parser. This allows to revert the patch "evaluate: improve rule managment checks" (4176c7d30c2ff1b3f52468fc9c08b8df83f979a8) and saves a lot of code. Signed-off-by: Carlos Falgueras García <carlosfg@riseup.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* parser_bison: keep snat/dnat existing syntax unchangedLiping Zhang2016-08-221-1/+14
| | | | | | | | | | | | | | | | | | | We should keep existing syntax unchanged, and this was emphasized in the commit 850f0a56b6ad ("src: add 'to' for snat and dnat")'s commit log: "Existing syntax is still preserved, but the listing shows the one including 'to'." This problem was found by running shell test: # ./run-tests.sh [ ... ] W: [FAILED] ./testcases/maps/anonymous_snat_map_0 I: [OK] ./testcases/maps/map_with_flags_0 W: [FAILED] ./testcases/maps/named_snat_map_0 [ ... ] Fixes: 850f0a56b6ad ("src: add 'to' for snat and dnat") Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* parser_bison: redirect to :port for consistency with nat/masq statementPablo Neira Ayuso2016-08-181-0/+9
| | | | | | | Use the colon port syntax for consistency with other statements. Existing syntax is still preserved but the output displays the colon. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>