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* tcpopt: don't create exthdr expression without datatypeFlorian Westphal2023-12-191-1/+1
| | | | | | | | | | | | | The reproducer crashes during concat evaluation, as the exthdr expression lacks a datatype. This should never happen, i->dtype must be set. In this case the culprit is tcp option parsing, it will wire up a non-existent template, because the "nop" option has no length field (1 byte only). Signed-off-by: Florian Westphal <fw@strlen.de>
* parser: tcpopt: fix tcp option parsing with NUM + length fieldFlorian Westphal2023-12-061-10/+34
| | | | | | | | | | | | | | | | | | | | | | tcp option 254 length ge 4 ... will segfault. The crash bug is that tcpopt_expr_alloc() can return NULL if we cannot find a suitable template for the requested kind + field combination, so add the needed error handling in the bison parser. However, we can handle this. NOP and EOL have templates, all other options (known or unknown) must also have a length field. So also add a fallback template to handle both kind and length, even if only a numeric option is given that nft doesn't recognize. Don't bother with output, above will be printed via raw syntax, i.e. tcp option @254,8,8 >= 4. Fixes: 24d8da308342 ("tcpopt: allow to check for presence of any tcp option") Reported-by: Maciej Żenczykowski <zenczykowski@gmail.com> Signed-off-by: Florian Westphal <fw@strlen.de>
* include: include <string.h> in <nft.h>Thomas Haller2023-09-281-1/+0
| | | | | | | | <string.h> provides strcmp(), as such it's very basic and used everywhere. Signed-off-by: Thomas Haller <thaller@redhat.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* include: include <stdlib.h> in <nft.h>Thomas Haller2023-09-111-1/+0
| | | | | | | | | | | | | | It provides malloc()/free(), which is so basic that we need it everywhere. Include via <nft.h>. The ultimate purpose is to define more things in <nft.h>. While it has not corresponding C sources, <nft.h> can contain macros and static inline functions, and is a good place for things that we shall have everywhere. Since <stdlib.h> provides malloc()/free() and size_t, that is a very basic dependency, that will be needed for that. Signed-off-by: Thomas Haller <thaller@redhat.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* include: include <std{bool,int}.h> via <nft.h>Thomas Haller2023-08-251-1/+0
| | | | | | | | | | | | | | | | | | | | There is a minimum base that all our sources will end up needing. This is what <nft.h> provides. Add <stdbool.h> and <stdint.h> there. It's unlikely that we want to implement anything, without having "bool" and "uint32_t" types available. Yes, this means the internal headers are not self-contained, with respect to what <nft.h> provides. This is the exception to the rule, and our internal headers should rely to have <nft.h> included for them. They should not include <nft.h> themselves, because <nft.h> needs always be included as first. So when an internal header would include <nft.h> it would be unnecessary, because the header is *always* included already. Signed-off-by: Thomas Haller <thaller@redhat.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: add <nft.h> header and include it as firstThomas Haller2023-08-251-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | <config.h> is generated by the configure script. As it contains our feature detection, it want to use it everywhere. Likewise, in some of our sources, we define _GNU_SOURCE. This defines the C variant we want to use. Such a define need to come before anything else, and it would be confusing if different source files adhere to a different C variant. It would be good to use autoconf's AC_USE_SYSTEM_EXTENSIONS, in which case we would also need to ensure that <config.h> is always included as first. Instead of going through all source files and include <config.h> as first, add a new header "include/nft.h", which is supposed to be included in all our sources (and as first). This will also allow us later to prepare some common base, like include <stdbool.h> everywhere. We aim that headers are self-contained, so that they can be included in any order. Which, by the way, already didn't work because some headers define _GNU_SOURCE, which would only work if the header gets included as first. <nft.h> is however an exception to the rule: everything we compile shall rely on having <nft.h> header included as first. This applies to source files (which explicitly include <nft.h>) and to internal header files (which are only compiled indirectly, by being included from a source file). Note that <config.h> has no include guards, which is at least ugly to include multiple times. It doesn't cause problems in practice, because it only contains defines and the compiler doesn't warn about redefining a macro with the same value. Still, <nft.h> also ensures to include <config.h> exactly once. Signed-off-by: Thomas Haller <thaller@redhat.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* exthdr: fix tcpopt_find_template to use length after mask adjustmentFlorian Westphal2021-12-011-4/+3
| | | | | | | | | | | | | | | | | | | | | | Unify binop handling for ipv6 extension header, ip option and tcp option processing. Pass the real offset and length expected, not the one used in the kernel. This was already done for extension headers and ip options, but tcp option parsing did not do this. This was fine before because no existing tcp option template had a non-byte sized member. With mptcp addition this isn't the case anymore, subtype field is only 4 bits wide, but tcp option delinearization passed 8bits instead. Pass the offset and mask delta, just like ip option/ipv6 exthdr. This makes nft show 'tcp option mptcp subtype 1' instead of 'tcp option mptcp unknown & 240 == 16'. Signed-off-by: Florian Westphal <fw@strlen.de>
* mptcp: add subtype matchingFlorian Westphal2021-12-011-0/+1
| | | | | | | | | | | | | | | | | | | | | | MPTCP multiplexes the various mptcp signalling data using the first 4 bits of the mptcp option. This allows to match on the mptcp subtype via: tcp option mptcp subtype 1 This misses delinearization support. mptcp subtype is the first tcp option field that has a length of less than one byte. Serialization processing will add a binop for this, but netlink delinearization can't remove them, yet. Also misses a new datatype/symbol table to allow to use mnemonics like 'mp_join' instead of raw numbers. For this reason, no tests are added yet. Signed-off-by: Florian Westphal <fw@strlen.de>
* tcpopt: add md5sig, fastopen and mptcp optionsFlorian Westphal2021-12-011-0/+30
| | | | | | | | | Allow to use "fastopen", "md5sig" and "mptcp" mnemonics rather than the raw option numbers. These new keywords are only recognized while scanner is in tcp state. Signed-off-by: Florian Westphal <fw@strlen.de>
* tcpopt: bogus assertion on undefined optionsPablo Neira Ayuso2021-08-111-1/+2
| | | | | | | | | | # nft add rule x y tcp option 6 exists # nft list ruleset nft: tcpopt.c:208: tcpopt_init_raw: Assertion `expr->exthdr.desc != NULL' failed. Aborted Closes: https://bugzilla.netfilter.org/show_bug.cgi?id=1557 Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* tcp: add raw tcp option match supportFlorian Westphal2020-11-091-0/+2
| | | | | | tcp option @42,16,4 (@kind,offset,length). Signed-off-by: Florian Westphal <fw@strlen.de>
* tcpopt: allow to check for presence of any tcp optionFlorian Westphal2020-11-091-6/+36
| | | | | | | | | | | | | nft currently doesn't allow to check for presence of arbitrary tcp options. Only known options where nft provides a template can be tested for. This allows to test for presence of raw protocol values as well. Example: tcp option 42 exists Signed-off-by: Florian Westphal <fw@strlen.de>
* tcpopt: split tcpopt_hdr_fields into per-option enumFlorian Westphal2020-11-091-68/+51
| | | | | | | | | | | | | | | | | | Currently we're limited to ten template fields in exthdr_desc struct. Using a single enum for all tpc option fields thus won't work indefinitely (TCPOPTHDR_FIELD_TSECR is 9) when new option templates get added. Fortunately we can just use one enum per tcp option to avoid this. As a side effect this also allows to simplify the sack offset calculations. Rather than computing that on-the-fly, just add extra fields to the SACK template. expr->exthdr.offset now holds the 'raw' value, filled in from the option template. This would ease implementation of 'raw option matching' using offset and length to load from the option. Signed-off-by: Florian Westphal <fw@strlen.de>
* tcpopt: rename noop to nopFlorian Westphal2020-11-091-1/+1
| | | | | | | 'nop' is the tcp padding "option". "noop" is retained for compatibility on parser side. Signed-off-by: Florian Westphal <fw@strlen.de>
* tcpopts: clean up parser -> tcpopt.c plumbingFlorian Westphal2020-11-091-57/+35
| | | | | | | | | | | | | | | | | tcpopt template mapping is asymmetric: one mapping is to match dumped netlink exthdr expression to the original tcp option template. This struct is indexed by the raw, on-write kind/type number. The other mapping maps parsed options to the tcp option template. Remove the latter. The parser is changed to translate the textual option name, e.g. "maxseg" to the on-wire number. This avoids the second mapping, it will also allow to more easily support raw option matching in a followup patch. Signed-off-by: Florian Westphal <fw@strlen.de>
* parser: merge sack-perm/sack-permitted and maxseg/mssFlorian Westphal2020-11-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | One was added by the tcp option parsing ocde, the other by synproxy. So we have: synproxy ... sack-perm synproxy ... mss and tcp option maxseg tcp option sack-permitted This kills the extra tokens on the scanner/parser side, so sack-perm and sack-permitted can both be used. Likewise, 'synproxy maxseg' and 'tcp option mss size 42' will work too. On the output side, the shorter form is now preferred, i.e. sack-perm and mss. Signed-off-by: Florian Westphal <fw@strlen.de>
* src: add reference counter for dynamic datatypesPablo Neira Ayuso2019-06-131-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are two datatypes are using runtime datatype allocation: * Concatenations. * Integer, that require byteorder adjustment. From the evaluation / postprocess step, transformations are common, hence expressions may end up fetching (infering) datatypes from an existing one. This patch adds a reference counter to release the dynamic datatype object when it is shared. The API includes the following helper functions: * datatype_set(expr, datatype), to assign a datatype to an expression. This helper already deals with reference counting for dynamic datatypes. This also drops the reference counter of any previous datatype (to deal with the datatype replacement case). * datatype_get(datatype) bumps the reference counter. This function also deals with nul-pointers, that occurs when the datatype is unset. * datatype_free() drops the reference counter, and it also releases the datatype if there are not more clients of it. Rule of thumb is: The reference counter of any newly allocated datatype is set to zero. This patch also updates every spot to use datatype_set() for non-dynamic datatypes, for consistency. In this case, the helper just makes an simple assignment. Note that expr_alloc() has been updated to call datatype_get() on the datatype that is assigned to this new expression. Moreover, expr_free() calls datatype_free(). This fixes valgrind reports like this one: ==28352== 1,350 (440 direct, 910 indirect) bytes in 5 blocks are definitely lost in loss recor 3 of 3 ==28352== at 0x4C2BBAF: malloc (vg_replace_malloc.c:299) ==28352== by 0x4E79558: xmalloc (utils.c:36) ==28352== by 0x4E7963D: xzalloc (utils.c:65) ==28352== by 0x4E6029B: dtype_alloc (datatype.c:1073) ==28352== by 0x4E6029B: concat_type_alloc (datatype.c:1127) ==28352== by 0x4E6D3B3: netlink_delinearize_set (netlink.c:578) ==28352== by 0x4E6D68E: list_set_cb (netlink.c:648) ==28352== by 0x5D74023: nftnl_set_list_foreach (set.c:780) ==28352== by 0x4E6D6F3: netlink_list_sets (netlink.c:669) ==28352== by 0x4E5A7A3: cache_init_objects (rule.c:159) ==28352== by 0x4E5A7A3: cache_init (rule.c:216) ==28352== by 0x4E5A7A3: cache_update (rule.c:266) ==28352== by 0x4E7E0EE: nft_evaluate (libnftables.c:388) ==28352== by 0x4E7EADD: nft_run_cmd_from_filename (libnftables.c:479) ==28352== by 0x109A53: main (main.c:310) This patch also removes the DTYPE_F_CLONE flag which is broken and not needed anymore since proper reference counting is in place. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: expr: remove expr_ops from struct exprFlorian Westphal2019-02-081-1/+1
| | | | | | | | size of struct expr changes from 144 to 128 bytes on x86_64. This doesn't look like much, but large rulesets can have tens of thousands of expressions (each set element is represented by an expression). Signed-off-by: Florian Westphal <fw@strlen.de>
* src: expr: add expression etypeFlorian Westphal2019-02-081-1/+1
| | | | | | | | 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>
* libnftables: Make some arrays globally accessiblePhil Sutter2018-05-111-1/+1
| | | | | | | | | | | | | | | This removes static flag and adds declarations in headers for the following arrays: * ct_templates from src/ct.c * mark_tbl from src/datatype.c * meta_templates and devgroup_tbl from src/meta.c * table_flags_name from src/rule.c * set_stmt_op_names from src/statement.c * tcpopthdr_protocols from src/tcpopt.c Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* tcpopt: make tcptopt structs staticFlorian Westphal2017-07-131-8/+8
| | | | | | | not used outside of tcpopt.c, so unexport from header file and make them static. Signed-off-by: Florian Westphal <fw@strlen.de>
* exthdr: Implement existence checkPhil Sutter2017-03-101-1/+5
| | | | | | | | | | | 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>
* exthdr: Add support for exthdr specific flagsPhil Sutter2017-03-101-2/+3
| | | | | | | | | 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: revisit tcp options supportPablo Neira Ayuso2017-02-281-89/+58
| | | | | | | | | | | | | | | | | | | 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: add TCP option matchingManuel Messner2017-02-121-0/+269
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>