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* netlink: add support for handling shift expressions.Jeremy Sowden2020-01-281-3/+47
| | | | | | | | | The kernel supports bitwise shift operations, so add support to the netlink linearization and delinearization code. The number of bits (the righthand operand) is expected to be a 32-bit value in host endianness. Signed-off-by: Jeremy Sowden <jeremy@azazel.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: white-space fixes.Jeremy Sowden2020-01-281-1/+1
| | | | | | | Remove some trailing white-space and fix some indentation. Signed-off-by: Jeremy Sowden <jeremy@azazel.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netlink: Avoid potential NULL-pointer deref in netlink_gen_payload_stmt()Phil Sutter2020-01-221-1/+1
| | | | | | | | | | With payload_needs_l4csum_update_pseudohdr() unconditionally dereferencing passed 'desc' parameter and a previous check for it to be non-NULL, make sure to call the function only if input is sane. Fixes: 68de70f2b3fc6 ("netlink_linearize: fix IPv6 layer 4 checksum mangling") Signed-off-by: Phil Sutter <phil@nwl.cc> Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: introduce SYNPROXY matchingFernando Fernandez Mancera2019-07-171-0/+17
| | | | | | | | | | | | | | | | | | | | Add support for "synproxy" statement. For example (for TCP port 8888): table ip x { chain y { type filter hook prerouting priority raw; policy accept; tcp dport 8888 tcp flags syn notrack } chain z { type filter hook input priority filter; policy accept; tcp dport 8888 ct state invalid,untracked synproxy mss 1460 wscale 7 timestamp sack-perm ct state invalid drop } } Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: use UDATA defines from libnftnlPhil Sutter2019-05-031-1/+1
| | | | | | | | | | | | | Userdata attribute names have been added to libnftnl, use them instead of the local copy. While being at it, rename udata_get_comment() in netlink_delinearize.c and the callback it uses since the function is specific to rules. Also integrate the existence check for NFTNL_RULE_USERDATA into it along with the call to nftnl_rule_get_data(). Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: add nat support for the inet familyFlorian Westphal2019-04-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | consider a simple ip6 nat table: table ip6 nat { chain output { type nat hook output priority 0; policy accept; dnat to dead:2::99 } Now consider same ruleset, but using 'table inet nat': nft now lacks context to determine address family to parse 'to $address'. This adds code to make the following work: table inet nat { [ .. ] # detect af from network protocol context: ip6 daddr dead::2::1 dnat to dead:2::99 # use new dnat ip6 keyword: dnat ip6 to dead:2::99 } On list side, the keyword is only shown in the inet family, else the short version (dnat to ...) is used as the family is redundant when the table already mandates the ip protocol version supported. Address mismatches such as table ip6 { .. dnat ip to 1.2.3.4 are detected/handled during the evaluation phase. Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
* osf: add version fingerprint supportFernando Fernandez Mancera2019-04-081-0/+1
| | | | | | | | | | | | | | | Add support for version fingerprint in "osf" expression. Example: table ip foo { chain bar { type filter hook input priority filter; policy accept; osf ttl skip name "Linux" osf ttl skip version "Linux:4.20" } } Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: expr: add expression etypeFlorian Westphal2019-02-081-13/+13
| | | | | | | | Temporary kludge to remove all the expr->ops->type == ... patterns. Followup patch will remove expr->ops, and make expr_ops() lookup the correct expr_ops struct instead to reduce struct expr size. Signed-off-by: Florian Westphal <fw@strlen.de>
* src: expr: add and use expr_name helperFlorian Westphal2019-02-081-1/+1
| | | | | | | | Currently callers use expr->ops->name, but follouwp patch will remove the ops pointer from struct expr. So add this helper and use it everywhere. Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
* osf: add ttl option supportFernando Fernandez Mancera2018-10-231-0/+1
| | | | | | | | | | | | | | Add support for ttl option in "osf" expression. Example: table ip foo { chain bar { type filter hook input priority filter; policy accept; osf ttl skip name "Linux" } } Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: add ipsec (xfrm) expressionMáté Eckl2018-09-211-0/+16
| | | | | | | | | | | | | | | | This allows matching on ipsec tunnel/beet addresses in xfrm state associated with a packet, ipsec request id and the SPI. Examples: ipsec in ip saddr 192.168.1.0/24 ipsec out ip6 daddr @endpoints ipsec in spi 1-65536 Joint work with Florian Westphal. Cc: Máté Eckl <ecklm94@gmail.com> Signed-off-by: Florian Westphal <fw@strlen.de>
* src: integrate stateful expressions into sets and mapsPablo Neira Ayuso2018-08-241-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following example shows how to populate a set from the packet path using the destination IP address, for each entry there is a counter. The entry expires after the 1 hour timeout if no packets matching this entry are seen. table ip x { set xyz { type ipv4_addr size 65535 flags dynamic,timeout timeout 1h } chain y { type filter hook output priority filter; policy accept; update @xyz { ip daddr counter } counter } } Similar example, that creates a mapping better IP address and mark, where the mark is assigned using an incremental sequence generator from 0 to 1 inclusive. table ip x { map xyz { type ipv4_addr : mark size 65535 flags dynamic,timeout timeout 1h } chain y { type filter hook input priority filter; policy accept; update @xyz { ip saddr counter : numgen inc mod 2 } } } Supported stateful statements are: limit, quota, counter and connlimit. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: simplify map statementPablo Neira Ayuso2018-08-241-10/+11
| | | | | | | Instead of using the map expression, store dynamic key and data separately since they need special handling than constant maps. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: introduce passive OS fingerprint matchingFernando Fernandez Mancera2018-08-041-0/+13
| | | | | | | | | | | | | | Add support for "osf" expression. Example: table ip foo { chain bar { type filter hook input priority 0; policy accept; osf name "Linux" counter packets 3 bytes 132 } } Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: Add tproxy supportMáté Eckl2018-08-031-0/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds support for transparent proxy functionality which is supported in ip, ip6 and inet tables. The syntax is the following: tproxy [{|ip|ip6}] to {<ip address>|:<port>|<ip address>:<port>} It looks for a socket listening on the specified address or port and assigns it to the matching packet. In an inet table, a packet matches for both families until address is specified. Network protocol family has to be specified **only** in inet tables if address is specified. As transparent proxy support is implemented for sockets with layer 4 information, a transport protocol header criterion has to be set in the same rule. eg. 'meta l4proto tcp' or 'udp dport 4444' Example ruleset: table ip x { chain y { type filter hook prerouting priority -150; policy accept; tcp dport ntp tproxy to 1.1.1.1 udp dport ssh tproxy to :2222 } } table ip6 x { chain y { type filter hook prerouting priority -150; policy accept; tcp dport ntp tproxy to [dead::beef] udp dport ssh tproxy to :2222 } } table inet x { chain y { type filter hook prerouting priority -150; policy accept; tcp dport 321 tproxy to :ssh tcp dport 99 tproxy ip to 1.1.1.1:999 udp dport 155 tproxy ip6 to [dead::beef]:smux } } Signed-off-by: Máté Eckl <ecklm94@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: Introduce socket matchingMáté Eckl2018-06-061-0/+14
| | | | | | | | | | | | | | | | For now it can only match sockets with IP(V6)_TRANSPARENT socket option set. Example: table inet sockin { chain sockchain { type filter hook prerouting priority -150; policy accept; socket transparent 1 mark set 0x00000001 nftrace set 1 counter packets 9 bytes 504 accept } } Signed-off-by: Máté Eckl <ecklm94@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* expr: extend fwd statement to support address and familyPablo Neira Ayuso2018-06-061-4/+15
| | | | | | | | Allow to forward packets through to explicit destination and interface. nft add rule netdev x y fwd ip to 192.168.2.200 device eth0 Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: connlimit supportPablo Neira Ayuso2018-06-061-0/+18
| | | | | | | | | | | | | | This patch adds support for the new connlimit stateful expression, that provides a mapping with the connlimit iptables extension through meters. eg. nft add rule filter input tcp dport 22 \ meter test { ip saddr ct count over 2 } counter reject This limits the maximum amount incoming of SSH connections per source address up to 2 simultaneous connections. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: add set_specPablo Neira Ayuso2018-05-061-5/+5
| | | | | | Store location object in handle to improve error reporting. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: avoid errouneous assert with map+concatFlorian Westphal2018-03-271-0/+8
| | | | | | | | | | | | | | | | | | Phil reported following assert: add rule ip6 f o mark set ip6 saddr . ip6 daddr . tcp dport \ map { dead::beef . f00::. 22 : 1 } nft: netlink_linearize.c:655: netlink_gen_expr: Assertion `dreg < ctx->reg_low' failed. This happens because "mark set" will allocate one register (the dreg), but netlink_gen_concat_expr will populate a lot more register space if the concat expression strings a lot of expressions together. As the assert is useful pseudo-reserve the register space as per concat->len and undo after generating the expressions. Reported-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Florian Westphal <fw@strlen.de>
* Combine redir and masq statements into natPhil Sutter2018-03-171-99/+36
| | | | | | | | | | | | | | | | | | | All these statements are very similar, handling them with the same code is obvious. The only thing required here is a custom extension of enum nft_nat_types which is used in nat_stmt to distinguish between snat and dnat already. Though since enum nft_nat_types is part of kernel uAPI, create a local extended version containing the additional fields. Note that nat statement printing got a bit more complicated to get the number of spaces right for every possible combination of attributes. Note also that there wasn't a case for STMT_MASQ in rule_parse_postprocess(), which seems like a bug. Since STMT_MASQ became just a variant of STMT_NAT, postprocessing will take place for it now anyway. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netlink: Fold netlink_gen_cmp() into netlink_gen_relational()Phil Sutter2018-03-161-65/+53
| | | | | | | | | Since netlink_gen_relational() didn't do much anymore after meta OP treating had been removed, it makes sense to merge it with the only function it dispached to. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* relational: Eliminate meta OPsPhil Sutter2018-03-161-7/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With a bit of code reorganization, relational meta OPs OP_RANGE, OP_FLAGCMP and OP_LOOKUP become unused and can be removed. The only meta OP left is OP_IMPLICIT which is usually treated as alias to OP_EQ. Though it needs to stay in place for one reason: When matching against a bitmask (e.g. TCP flags or conntrack states), it has a different meaning: | nft --debug=netlink add rule ip t c tcp flags syn | ip t c | [ meta load l4proto => reg 1 ] | [ cmp eq reg 1 0x00000006 ] | [ payload load 1b @ transport header + 13 => reg 1 ] | [ bitwise reg 1 = (reg=1 & 0x00000002 ) ^ 0x00000000 ] | [ cmp neq reg 1 0x00000000 ] | nft --debug=netlink add rule ip t c tcp flags == syn | ip t c | [ meta load l4proto => reg 1 ] | [ cmp eq reg 1 0x00000006 ] | [ payload load 1b @ transport header + 13 => reg 1 ] | [ cmp eq reg 1 0x00000002 ] OP_IMPLICIT creates a match which just checks the given flag is present, while OP_EQ creates a match which ensures the given flag and no other is present. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: support of dynamic map addition and update of elementsLaura Garcia Liebana2018-03-151-0/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The support of dynamic adds and updates are only available for sets and meters. This patch gives such abilities to maps as well. This patch is useful in cases where dynamic population of maps are required, for example, to maintain a persistence during some period of time. Example: table ip nftlb { map persistencia { type ipv4_addr : mark timeout 1h elements = { 192.168.1.132 expires 59m55s : 0x00000064, 192.168.56.101 expires 59m24s : 0x00000065 } } chain pre { type nat hook prerouting priority 0; policy accept; map update \ { @nh,96,32 : numgen inc mod 2 offset 100 } @persistencia } } An example of the netlink generated sequence: nft --debug=netlink add rule ip nftlb pre map add \ { ip saddr : numgen inc mod 2 offset 100 } @persistencia ip nftlb pre [ payload load 4b @ network header + 12 => reg 1 ] [ numgen reg 2 = inc mod 2 offset 100 ] [ dynset add reg_key 1 set persistencia sreg_data 2 ] Signed-off-by: Laura Garcia Liebana <nevola@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: flow offload supportPablo Neira Ayuso2018-03-051-0/+13
| | | | | | | | | | | | This patch allows us to refer to existing flowtables: # nft add rule x x flow offload @m Packets matching this rule create an entry in the flow table 'm', hence, follow up packets that get to the flowtable at ingress bypass the classic forwarding path. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* meta: introduce datatype ifname_typeArturo Borrero Gonzalez2018-02-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | This new datatype is a string subtype. It will allow us to build named maps/sets using meta keys like 'iifname', 'oifname', 'ibriport' or 'obriport'. Example: table inet t { set s { type ifname elements = { "eth0", "eth1" } } chain c { iifname @s accept oifname @s accept } } Signed-off-by: Arturo Borrero Gonzalez <arturo@netfilter.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netlink_linearize: exthdr op must be u32Florian Westphal2017-12-111-2/+2
| | | | | | | | libnftnl casts this to u32. Broke exthdr expressions on bigendian. Reported-by: Li Shuang <shuali@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: deprecate "flow table" syntax, replace it by "meter"Pablo Neira Ayuso2017-11-241-13/+13
| | | | | | | | | | | | | | | | | | | | | | | | | According to bugzilla 1137: "flow tables" should not be syntactically unique. "Flow tables are always named, but they don't conform to the way sets, maps, and dictionaries work in terms of "add" and "delete" and all that. They are also "flow tables" instead of one word like "flows" or "throttle" or something. It seems weird to just have these break the syntactic expectations." Personally, I never liked the reference to "table" since we have very specific semantics in terms of what a "table" is netfilter for long time. This patch promotes "meter" as the new keyword. The former syntax is still accepted for a while, just to reduce chances of breaking things. At some point the former syntax will just be removed. Closes: https://bugzilla.netfilter.org/show_bug.cgi?id=1137 Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Acked-by: Arturo Borrero Gonzalez <arturo@netfilter.org>
* netlink_linearize: skip set element expression in set statement keyAnders K. Pedersen2017-10-061-3/+3
| | | | | | | | | | | | | | | | | | | | Before this patch the following fails: # nft add rule ip6 filter x \ set add ip6 saddr . ip6 daddr @test nft: netlink_linearize.c:648: netlink_gen_expr: Assertion `dreg < ctx->reg_low' failed. Aborted This is was previously fixed for flow statements in fbea4a6f4449 ("netlink_linearize: skip set element expression in flow table key"), and this patch implements the same change for set statements by using the set element key in netlink_gen_set_stmt(). nft-test.py is updated to support set types with concatenated data types in order to support testing of this. Signed-off-by: Anders K. Pedersen <akp@cohaesio.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: get rid of printfPhil Sutter2017-09-291-1/+1
| | | | | | | | | | | | | | | | | This patch introduces nft_print()/nft_gmp_print() functions which have to be used instead of printf to output information that were previously send to stdout. These functions print to a FILE pointer defined in struct output_ctx. It is set by calling: | old_fp = nft_ctx_set_output(ctx, new_fp); Having an application-defined FILE pointer is actually quite flexible: Using fmemopen() or even fopencookie(), an application gains full control over what is printed and where it should go to. Signed-off-by: Eric Leblond <eric@regit.org> Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: add debugging mask to context structurePablo Neira Ayuso2017-08-231-1/+1
| | | | | | | So this toggle is not global anymore. Update name that fits better with the semantics of this variable. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: add tcp options set supportFlorian Westphal2017-08-221-0/+29
| | | | | | | | | | | | This adds support for tcp mss mangling: nft add rule filter input tcp option maxseg size 1200 Its also possible to change other tcp option fields, but maxseg is one of the more useful ones to change. Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
* hash: generate a random seed if seed option is emptyLiping Zhang2017-04-151-1/+2
| | | | | | | | | | | Typing the "nft add rule x y ct mark set jhash ip saddr mod 2" will not generate a random seed, instead, the seed will always be zero. So if seed option is empty, we shoulde not set the NFTA_HASH_SEED attribute, then a random seed will be generated in the kernel. Signed-off-by: Liping Zhang <zlpnobody@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* exthdr: Add support for exthdr specific flagsPhil Sutter2017-03-101-0/+1
| | | | | | | | | This allows to have custom flags in exthdr expression, which is necessary for upcoming existence checks (of both IPv6 extension headers as well as TCP options). Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: hash: support of symmetric hashLaura Garcia Liebana2017-03-061-7/+12
| | | | | | | | | | | | | | | | | | | | | 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: support zone set statement with optional directionFlorian Westphal2017-02-281-0/+4
| | | | | | | | | | | | 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 TCP option matchingManuel Messner2017-02-121-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* exthdr: prepare for tcp supportManuel Messner2017-02-121-2/+2
| | | | | | | | | | | right now exthdr only deals with ipv6 extension headers, followup patch will enable tcp option matching. This adds the 'op' arg to exthdr_init. Signed-off-by: Manuel Messner <mm@skelett.io> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: Florian Westphal <fw@strlen.de>
* src: add support for stateful object mapsPablo Neira Ayuso2017-01-031-3/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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/+16
| | | | | | | | | 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>
* src: add used quota supportPablo Neira Ayuso2017-01-031-0/+1
| | | | | | | | | | | | | 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>
* netlink_linearize: fix IPv6 layer 4 checksum manglingPablo Neira Ayuso2016-12-161-5/+4
| | | | | | | In IPv6 there is no checksum field. We always have to trigger layer 4 checksum mangling if any of the layer 3 pseudoheader fields are updated. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: trigger layer 4 checksum when pseudoheader fields are modifiedPablo Neira2016-12-041-0/+17
| | | | | | | | This patch sets the NFT_PAYLOAD_L4CSUM_PSEUDOHDR when any of the pseudoheader fields are modified. This implicitly enables stateless NAT, that can be useful under some circuntances. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: Interpret OP_NEQ against a set as OP_LOOKUPAnatole Denis2016-11-291-5/+9
| | | | | | | | | | Now that the support for inverted matching is in the kernel and in libnftnl, add it to nftables too. This fixes bug #888 Signed-off-by: Anatole Denis <anatole@rezel.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: add log flags syntax supportLiping Zhang2016-11-241-0/+3
| | | | | | | | | | | | | | | | | | | | | 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/+11
| | | | | | | 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 Liebana2016-11-091-0/+1
| | | | | | | | | | | 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>
* netlink_linearize: skip set element expression in flow table keyPablo Neira Ayuso2016-10-311-3/+3
| | | | | | | | | | | | | | | | | | | | | Anders reports that: # nft add rule ip6 filter postrouting \ flow table acct_out \{ meta iif . ip6 saddr timeout 600s counter \} while the opposite doesn't work: # nft add rule ip6 filter postrouting \ flow table acct_out \{ ip6 saddr . meta iif timeout 600s counter \} netlink_gen_flow_stmt() relies on the flow table key, that is expressed as a set element. Use the set element key instead to skip the set element wrap, otherwise get_register() abort execution: nft: netlink_linearize.c:650: netlink_gen_expr: Assertion `dreg < ctx->reg_low' failed. Reported-by: Anders K. Pedersen <akp@cohaesio.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: add fib expressionFlorian Westphal2016-10-281-0/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>