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* src: get rid of printfPhil Sutter2017-09-291-7/+8
| | | | | | | | | | | | | | | | | 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>
* exthdr: Simplify tcp option printing a bitPhil Sutter2017-09-291-8/+4
| | | | | | | This eliminates the need for that temporary buffer. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: add tcp options set supportFlorian Westphal2017-08-221-0/+25
| | | | | | | | | | | | 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>
* exhtdr: pacify compiler warningFlorian Westphal2017-07-131-1/+1
| | | | | | | | | | | | gcc 7.1.1 complains: exthdr.c:41:31: warning: ‘%d’ directive output may be truncated writing between 1 and 8 bytes into a region of size 3 [-Wformat-truncation=] snprintf(buf, sizeof buf, "%d", offset); ^~ This warning is incorrect, as offset is limited by tcp option ranges, but gcc doesn't know this. Increase buffer to avoid the warning. Signed-off-by: Florian Westphal <fw@strlen.de>
* include: Remove datatype_register().Varsha Rao2017-06-301-6/+1
| | | | | | | | Remove datatype_register() function and its calling __init functions. Add arguments of datatype_register() function to datatype array. Signed-off-by: Varsha Rao <rvarsha016@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: Pass stateless, numeric, ip2name and handle variables as structure members.Varsha Rao2017-06-181-1/+1
| | | | | | | | | | | | | | | | | libnftables library will be created soon. So declare numeric_output, stateless_output, ip2name_output and handle_output as members of structure output_ctx, instead of global variables. Rename these variables as following, numeric_output -> numeric stateless_output -> stateless ip2name_output -> ip2name handle_output -> handle Also add struct output_ctx *octx as member of struct netlink_ctx. Signed-off-by: Varsha Rao <rvarsha016@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* exthdr: avoid crash with older kernelsFlorian Westphal2017-04-081-16/+21
| | | | | | | | | | | | | | | | | | if kernel is older it won't understand the EXTHDR_OP attribute, i.e. the rule gets accepted as a check for ipv6 exthdr. On dump nft is then presented with a invalid ipv6 exthdr. So we need to get rid of the assert and output an "invalid" message on list. Longterm we need a proper vm description or kernel-side check to reject such messages in first place. After patch, test suite yields erros of type ip6/tcpopt.t: WARNING: 'src/nft add rule --debug=netlink ip6 test-ip6 \ input tcp option sack right 1': 'tcp option sack right 1' mismatches 'ip6 nexthdr 6 unknown-exthdr unknown 0x1 [invalid type]' Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
* exthdr: Implement existence checkPhil Sutter2017-03-101-4/+24
| | | | | | | | | | | 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 Sutter2017-03-101-4/+7
| | | | | | | | | 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 Ayuso2017-02-281-1/+1
| | | | | | | | | | | | | | | | | | | 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 Messner2017-02-121-3/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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/+3
| | | | | | | | | | | 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>
* expression: Show the base which pre-defined constants are displayedElise Lennion2016-12-201-0/+1
| | | | | | | | | | so the user know how we express it. The base was added to all symbol tables, which are associated with datatype->sym_tbl, so they are displayed in the right base. Signed-off-by: Elise Lennion <elise.lennion@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* netlink_delinearize: handle extension header templates with odd sizesFlorian Westphal2016-03-021-0/+31
| | | | | | | | | | | | | | | | | | This enables nft to display frag frag-off 33 ... by considering a mask during binop postprocess in case the initial template lookup done when the exthdr expression was created did not yield a match. In the above example, kernel netlink data specifies 16bits, but the frag field is only 13bits wide. We use the implicit binop mask to re-do the template lookup with corrected offset and size information. Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
* exthdr: store offset for later useFlorian Westphal2016-03-021-0/+2
| | | | | | | | Its possible that we cannot find the template without also considering an implicit mask. For this we need to store the offset. Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: add specific byteorder to the struct proto_hdr_templateAlvaro Neira Ayuso2014-09-171-1/+5
| | | | | | | | | | | | | | | | | | | | | If we try to add a rule like: nft add rule filter input udp length {55-9999} nftable shows: BUG: invalid byte order conversion 0 => 2 nft: src/evaluate.c:153: byteorder_conversion_op: Assertion `0' failed. Some of the existing payload fields rely on BYTEORDER_INVALID. Therefore, if we try to convert it in evaluation step, we hit this bug. This patch allows to add a specific byteorder to the struct proto_hdr_template. If we create a expression with a invalid byteorder, we will use the byteorder added to the proto_hdr_template structure. Signed-off-by: Alvaro Neira Ayuso <alvaroneay@gmail.com> Signed-off-by: Patrick McHardy <kaber@trash.net>
* expr: add comparison function for singleton expressionsPatrick McHardy2014-03-071-0/+7
| | | | Singed-off-by: Patrick McHardy <kaber@trash.net>
* nftables: generic procotol contextsPatrick McHardy2014-01-081-13/+13
| | | | | | | | | | | | | | | Currently the context of higher layer protocols is specific to payload expressions with some special cases for meta IIFTYPE expressions. This approach has a few shortcomings, concretely there are more expression types which define upper layer protocols like the ct expression and two upcoming new types for the meta expression. Replace the payload context by a generic protocol context to deal with this. This patch just splits off the requires parts from the payload expression without any functional changes, the following patches will add further functionality for other expressions. Signed-off-by: Patrick McHardy <kaber@trash.net>
* datatype: add/move size and byte order information into data typesPatrick McHardy2009-03-311-2/+2
| | | | | | | | | | Add size and type information to non-basetype types and remove the now redundant information from the symbol tables. This will be used to determine size and byteorder of set members without analyzing the ruleset for incremental update operations. Signed-off-by: Patrick McHardy <kaber@trash.net>
* datatype: maintain table of all datatypes and add registration/lookup functionPatrick McHardy2009-03-311-1/+7
| | | | | | | | | | | Add a table containing all available datatypes and registration/lookup functions. This will be used to associate a stand-alone set in the kernel with the correct type without parsing the entire ruleset. Additionally it would now be possible to remove the global declarations for the core types. Not done yet though. Signed-off-by: Patrick McHardy <kaber@trash.net>
* expr: add support for cloning expressionsPatrick McHardy2009-03-201-0/+7
| | | | Signed-off-by: Patrick McHardy <kaber@trash.net>
* Initial commitv0.01-alpha1Patrick McHardy2009-03-181-0/+238