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* use nf_tables and nf_tables compatibility interfacePablo Neira Ayuso2013-12-301-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds the following utilities: * xtables * xtables-restore * xtables-save * xtables-config They all use Patrick's nf_tables infrastructure plus my compatibility layer. xtables, xtables-restore and xtables-save are syntax compatible with ip[6]tables, ip[6]tables-restore and ip[6]tables-save. Semantics aims to be similar, still the main exception is that there is no commit operation. Thus, we incrementally add/delete rules without entire table locking. The following options are also not yet implemented: -Z (this requires adding expr->ops->reset(...) so nft_counters can reset internal state of expressions while dumping it) -R and -E (this requires adding this feature to nf_tables) -f (can be implemented with expressions: payload 6 (2-bytes) + bitwise a&b^!b + cmp neq 0) -IPv6 support. But those are a matter of time to get them done. A new utility, xtables-config, is available to register tables and chains. By default there is a configuration file that adds backward compatible tables and chains under iptables/etc/xtables.conf. You have to call this utility first to register tables and chains. However, it would be possible to automagically register tables and chains while using xtables and xtables-restore to get similar operation than with iptables. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* ip[6]tables: Add locking to prevent concurrent instancesPhil Oester2013-06-111-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There have been numerous complaints and bug reports over the years when admins attempt to run more than one instance of iptables simultaneously. Currently open bug reports which are related: 325: Parallel execution of the iptables is impossible 758: Retry iptables command on transient failure 764: Doing -Z twice in parallel breaks counters 822: iptables shows negative or other bad packet/byte counts As Patrick notes in 325: "Since this has been a problem people keep running into, I'd suggest to simply add some locking to iptables to catch the most common case." I started looking into alternatives to add locking, and of course the most common/obvious solution is to use a pidfile. But this has various downsides, such as if the application is terminated abnormally and the pidfile isn't cleaned up. And this also requires a writable filesystem. Using a UNIX domain socket file (e.g. in /var/run) has similar issues. Starting in 2.2, Linux added support for abstract sockets. These sockets require no filesystem, and automatically disappear once the application terminates. This is the locking solution I chose to implement in ip[6]tables. As an added bonus, since each network namespace has its own socket pool, an ip[6]tables instance running in one namespace will not lock out an ip[6]tables instance running in another namespace. A filesystem approach would have to recognize and handle multiple network namespaces. Signed-off-by: Phil Oester <kernel@linuxace.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
* iptables: consolidate target/match init callJan Engelhardt2011-06-211-0/+2
| | | | | | | This is useful for the upcoming patch about per-instance auxiliary data. Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
* option: fix ignored negation before implicit extension loadingJan Engelhardt2011-06-071-1/+1
| | | | | | | | | | | | `iptables -A INPUT -p tcp ! --syn` forgot the negation, i.e. it was not present in a subsequent `iptables -S`. Commit v1.4.11~77^2~9 missed the fact that after autoloading a proto extension, cs.invert must not be touched until the next getopt call. This is now fixed by having command_default return a value to indicate whether to jump or not. Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
* src: move all iptables pieces into a separate directoryJan Engelhardt2011-06-071-0/+87
(Unclutter top-level dir) Signed-off-by: Jan Engelhardt <jengelh@medozas.de>