kernel/include/net/netns/nftables.h, branch linux-6.18.y

netfilter: nf_tables: place base_seq in struct net

2025-09-10T18:30:37Z

This will soon be read from packet path around same time as the gencursor. Both gencursor and base_seq get incremented almost at the same time, so it makes sense to place them in the same structure. This doesn't increase struct net size on 64bit due to padding. Signed-off-by: Florian Westphal

net: Remove leftover include from nftables.h

2023-08-13T13:55:25Z

Commit db3685b4046f ("net: remove obsolete members from struct net") removed the uses of struct list_head from this header, without removing the corresponding included header. Signed-off-by: Jörn-Thorben Hinz Reviewed-by: Simon Horman Signed-off-by: David S. Miller

net: remove obsolete members from struct net

2021-04-05T22:34:53Z

all have been moved to generic_net infra. On x86_64, this reduces struct net size from 70 to 63 cache lines (4480 to 4032 byte). Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: coalesce multiple notifications into one skbuff

2020-09-08T11:02:44Z

On x86_64, each notification results in one skbuff allocation which consumes at least 768 bytes due to the skbuff overhead. This patch coalesces several notifications into one single skbuff, so each notification consumes at least ~211 bytes, that ~3.5 times less memory consumption. As a result, this is reducing the chances to exhaust the netlink socket receive buffer. Rule of thumb is that each notification batch only contains netlink messages whose report flag is the same, nfnetlink_send() requires this to do appropriate delivery to userspace, either via unicast (echo mode) or multicast (monitor mode). The skbuff control buffer is used to annotate the report flag for later handling at the new coalescing routine. The batch skbuff notification size is NLMSG_GOODSIZE, using a larger skbuff would allow for more socket receiver buffer savings (to amortize the cost of the skbuff even more), however, going over that size might break userspace applications, so let's be conservative and stick to NLMSG_GOODSIZE. Reported-by: Phil Sutter Acked-by: Phil Sutter Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: autoload modules from the abort path

2020-01-24T19:54:29Z

This patch introduces a list of pending module requests. This new module list is composed of nft_module_request objects that contain the module name and one status field that tells if the module has been already loaded (the 'done' field). In the first pass, from the preparation phase, the netlink command finds that a module is missing on this list. Then, a module request is allocated and added to this list and nft_request_module() returns -EAGAIN. This triggers the abort path with the autoload parameter set on from nfnetlink, request_module() is called and the module request enters the 'done' state. Since the mutex is released when loading modules from the abort phase, the module list is zapped so this is iteration occurs over a local list. Therefore, the request_module() calls happen when object lists are in consistent state (after fulling aborting the transaction) and the commit list is empty. On the second pass, the netlink command will find that it already tried to load the module, so it does not request it again and nft_request_module() returns 0. Then, there is a look up to find the object that the command was missing. If the module was successfully loaded, the command proceeds normally since it finds the missing object in place, otherwise -ENOENT is reported to userspace. This patch also updates nfnetlink to include the reason to enter the abort phase, which is required for this new autoload module rationale. Fixes: ec7470b834fe ("netfilter: nf_tables: store transaction list locally while requesting module") Reported-by: syzbot+29125d208b3dae9a7019@syzkaller.appspotmail.com Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: use dedicated mutex to guard transactions

2018-07-18T09:26:48Z

Continue to use nftnl subsys mutex to protect (un)registration of hook types, expressions and so on, but force batch operations to do their own locking. This allows distinct net namespaces to perform transactions in parallel. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: fix chain dependency validation

2018-06-01T07:46:22Z

The following ruleset: add table ip filter add chain ip filter input { type filter hook input priority 4; } add chain ip filter ap add rule ip filter input jump ap add rule ip filter ap masquerade results in a panic, because the masquerade extension should be rejected from the filter chain. The existing validation is missing a chain dependency check when the rule is added to the non-base chain. This patch fixes the problem by walking down the rules from the basechains, searching for either immediate or lookup expressions, then jumping to non-base chains and again walking down the rules to perform the expression validation, so we make sure the full ruleset graph is validated. This is done only once from the commit phase, in case of problem, we abort the transaction and perform fine grain validation for error reporting. This patch requires 003087911af2 ("netfilter: nfnetlink: allow commit to fail") to achieve this behaviour. This patch also adds a cleanup callback to nfnl batch interface to reset the validate state from the exit path. As a result of this patch, nf_tables_check_loops() doesn't use ->validate to check for loops, instead it just checks for immediate expressions. Reported-by: Taehee Yoo Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: remove nft_af_info.

2018-05-23T10:16:25Z

The struct nft_af_info was removed. Signed-off-by: Taehee Yoo Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: get rid of pernet families

2018-01-10T14:32:10Z

Now that we have a single table list for each netns, we can get rid of one pointer per family and the global afinfo list, thus, shrinking struct netns for nftables that now becomes 64 bytes smaller. And call __nft_release_afinfo() from __net_exit path accordingly to release netnamespace objects on removal. Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: add single table list for all families

2018-01-10T14:32:08Z

Place all existing user defined tables in struct net *, instead of having one list per family. This saves us from one level of indentation in netlink dump functions. Place pointer to struct nft_af_info in struct nft_table temporarily, as we still need this to put back reference module reference counter on table removal. This patch comes in preparation for the removal of struct nft_af_info. Signed-off-by: Pablo Neira Ayuso