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* 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>
* src: Add GPLv2+ header to .c files of recent creationPablo Neira Ayuso2023-01-021-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch comes after a proposal of mine at NFWS 2022 that resulted in agreement to license recent .c files under GPLv2+ by the attendees at this meeting: - Stefano Brivio - Fernando F. Mancera - Phil Sutter - Jozsef Kadlecsik - Florian Westphal - Laura Garcia - Arturo Borrero - Pablo Neira It has already happened that one of the external library dependencies was moved to GPLv3+ (libreadline), resulting in a change to libedit by default in b4dded0ca78d ("configure: default to libedit for cli"). I have added the GPLv2+ header to the following files: Authors ------- src/cmd.c Pablo src/fib.c Florian src/hash.c Pablo src/iface.c Pablo src/json.c Phil + fixes from occasional contributors src/libnftables.c Eric Leblond and Phil src/mergesort.c Elise Lenion src/misspell.c Pablo src/mnl.c Pablo + fixes from occasional contributors src/monitor.c Arturo src/numgen.c Pablo src/osf.c Fernando src/owner.c Pablo src/parser_json.c Phil + fixes from occasional contributors src/print.c Phil src/xfrm.c Florian src/xt.c Pablo Eric Leblond and Elise Lennion did not attend NFWS 2022, but they acknowledged this license update already in the past when I proposed this to them in private emails. Update COPYING file too to refer that we are now moving towards GPLv2 or any later. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* numgen: add parse and build userdata interfacePablo Neira Ayuso2019-12-171-0/+62
| | | | | | | Add support for meta userdata area. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Florian Westphal <fw@strlen.de>
* src: expr: remove expr_ops from struct exprFlorian Westphal2019-02-081-2/+2
| | | | | | | | 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>
* libnftables: Implement JSON output supportPhil Sutter2018-05-111-0/+1
| | | | | | | | | | | | Although technically there already is support for JSON output via 'nft export json' command, it is hardly useable since it exports all the gory details of nftables VM. Also, libnftables has no control over what is exported since the content comes directly from libnftnl. Instead, implement JSON format support for regular 'nft list' commands. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* src: get rid of printfPhil Sutter2017-09-291-3/+4
| | | | | | | | | | | | | | | | | 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: 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>
* src: add offset attribute for numgen expressionLaura Garcia Liebana2016-10-271-2/+8
| | | | | | | | | | | | | 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: add numgen expressionPablo Neira Ayuso2016-08-291-0/+68
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>