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path: root/include/net/netfilter/nf_tables.h
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2025-05-23netfilter: nf_tables: Add notifications for hook changesPhil Sutter
Notify user space if netdev hooks are updated due to netdev add/remove events. Send minimal notification messages by introducing NFT_MSG_NEWDEV/DELDEV message types describing a single device only. Upon NETDEV_CHANGENAME, the callback has no information about the interface's old name. To provide a clear message to user space, include the hook's stored interface name in the notification. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2025-05-23netfilter: nf_tables: Have a list of nf_hook_ops in nft_hookPhil Sutter
Supporting a 1:n relationship between nft_hook and nf_hook_ops is convenient since a chain's or flowtable's nft_hooks may remain in place despite matching interfaces disappearing. This stabilizes ruleset dumps in that regard and opens the possibility to claim newly added interfaces which match the spec. Also it prepares for wildcard interface specs since these will potentially match multiple interfaces. All spots dealing with hook registration are updated to handle a list of multiple nf_hook_ops, but nft_netdev_hook_alloc() only adds a single item for now to retain the old behaviour. The only expected functional change here is how vanishing interfaces are handled: Instead of dropping the respective nft_hook, only the matching nf_hook_ops are dropped. To safely remove individual ops from the list in netdev handlers, an rcu_head is added to struct nf_hook_ops so kfree_rcu() may be used. There is at least nft_flowtable_find_dev() which may be iterating through the list at the same time. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2025-05-23netfilter: nf_tables: Introduce nft_hook_find_ops{,_rcu}()Phil Sutter
Also a pretty dull wrapper around the hook->ops.dev comparison for now. Will search the embedded nf_hook_ops list in future. The ugly cast to eliminate the const qualifier will vanish then, too. Since this future list will be RCU-protected, also introduce an _rcu() variant here. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2025-03-06netfilter: nf_tables: make destruction work queue pernetFlorian Westphal
The call to flush_work before tearing down a table from the netlink notifier was supposed to make sure that all earlier updates (e.g. rule add) that might reference that table have been processed. Unfortunately, flush_work() waits for the last queued instance. This could be an instance that is different from the one that we must wait for. This is because transactions are protected with a pernet mutex, but the work item is global, so holding the transaction mutex doesn't prevent another netns from queueing more work. Make the work item pernet so that flush_work() will wait for all transactions queued from this netns. A welcome side effect is that we no longer need to wait for transaction objects from foreign netns. The gc work queue is still global. This seems to be ok because nft_set structures are reference counted and each container structure owns a reference on the net namespace. The destroy_list is still protected by a global spinlock rather than pernet one but the hold time is very short anyway. v2: call cancel_work_sync before reaping the remaining tables (Pablo). Fixes: 9f6958ba2e90 ("netfilter: nf_tables: unconditionally flush pending work before notifier") Reported-by: syzbot+5d8c5789c8cb076b2c25@syzkaller.appspotmail.com Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2025-01-19netfilter: nf_tables: Tolerate chains with no remaining hooksPhil Sutter
Do not drop a netdev-family chain if the last interface it is registered for vanishes. Users dumping and storing the ruleset upon shutdown to restore it upon next boot may otherwise lose the chain and all contained rules. They will still lose the list of devices, a later patch will fix that. For now, this aligns the event handler's behaviour with that for flowtables. The controversal situation at netns exit should be no problem here: event handler will unregister the hooks, core nftables cleanup code will drop the chain itself. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2025-01-19netfilter: nf_tables: Store user-defined hook ifnamePhil Sutter
Prepare for hooks with NULL ops.dev pointer (due to non-existent device) and store the interface name and length as specified by the user upon creation. No functional change intended. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2025-01-19netfilter: nf_tables: fix set size with rbtree backendPablo Neira Ayuso
The existing rbtree implementation uses singleton elements to represent ranges, however, userspace provides a set size according to the number of ranges in the set. Adjust provided userspace set size to the number of singleton elements in the kernel by multiplying the range by two. Check if the no-match all-zero element is already in the set, in such case release one slot in the set size. Fixes: 0ed6389c483d ("netfilter: nf_tables: rename set implementations") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-12-25netfilter: nft_set_hash: unaligned atomic read on struct nft_set_extPablo Neira Ayuso
Access to genmask field in struct nft_set_ext results in unaligned atomic read: [ 72.130109] Unable to handle kernel paging request at virtual address ffff0000c2bb708c [ 72.131036] Mem abort info: [ 72.131213] ESR = 0x0000000096000021 [ 72.131446] EC = 0x25: DABT (current EL), IL = 32 bits [ 72.132209] SET = 0, FnV = 0 [ 72.133216] EA = 0, S1PTW = 0 [ 72.134080] FSC = 0x21: alignment fault [ 72.135593] Data abort info: [ 72.137194] ISV = 0, ISS = 0x00000021, ISS2 = 0x00000000 [ 72.142351] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 72.145989] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 72.150115] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000237d27000 [ 72.154893] [ffff0000c2bb708c] pgd=0000000000000000, p4d=180000023ffff403, pud=180000023f84b403, pmd=180000023f835403, +pte=0068000102bb7707 [ 72.163021] Internal error: Oops: 0000000096000021 [#1] SMP [...] [ 72.170041] CPU: 7 UID: 0 PID: 54 Comm: kworker/7:0 Tainted: G E 6.13.0-rc3+ #2 [ 72.170509] Tainted: [E]=UNSIGNED_MODULE [ 72.170720] Hardware name: QEMU QEMU Virtual Machine, BIOS edk2-stable202302-for-qemu 03/01/2023 [ 72.171192] Workqueue: events_power_efficient nft_rhash_gc [nf_tables] [ 72.171552] pstate: 21400005 (nzCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) [ 72.171915] pc : nft_rhash_gc+0x200/0x2d8 [nf_tables] [ 72.172166] lr : nft_rhash_gc+0x128/0x2d8 [nf_tables] [ 72.172546] sp : ffff800081f2bce0 [ 72.172724] x29: ffff800081f2bd40 x28: ffff0000c2bb708c x27: 0000000000000038 [ 72.173078] x26: ffff0000c6780ef0 x25: ffff0000c643df00 x24: ffff0000c6778f78 [ 72.173431] x23: 000000000000001a x22: ffff0000c4b1f000 x21: ffff0000c6780f78 [ 72.173782] x20: ffff0000c2bb70dc x19: ffff0000c2bb7080 x18: 0000000000000000 [ 72.174135] x17: ffff0000c0a4e1c0 x16: 0000000000003000 x15: 0000ac26d173b978 [ 72.174485] x14: ffffffffffffffff x13: 0000000000000030 x12: ffff0000c6780ef0 [ 72.174841] x11: 0000000000000000 x10: ffff800081f2bcf8 x9 : ffff0000c3000000 [ 72.175193] x8 : 00000000000004be x7 : 0000000000000000 x6 : 0000000000000000 [ 72.175544] x5 : 0000000000000040 x4 : ffff0000c3000010 x3 : 0000000000000000 [ 72.175871] x2 : 0000000000003a98 x1 : ffff0000c2bb708c x0 : 0000000000000004 [ 72.176207] Call trace: [ 72.176316] nft_rhash_gc+0x200/0x2d8 [nf_tables] (P) [ 72.176653] process_one_work+0x178/0x3d0 [ 72.176831] worker_thread+0x200/0x3f0 [ 72.176995] kthread+0xe8/0xf8 [ 72.177130] ret_from_fork+0x10/0x20 [ 72.177289] Code: 54fff984 d503201f d2800080 91003261 (f820303f) [ 72.177557] ---[ end trace 0000000000000000 ]--- Align struct nft_set_ext to word size to address this and documentation it. pahole reports that this increases the size of elements for rhash and pipapo in 8 bytes on x86_64. Fixes: 7ffc7481153b ("netfilter: nft_set_hash: skip duplicated elements pending gc run") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-12-11netfilter: nf_tables: do not defer rule destruction via call_rcuFlorian Westphal
nf_tables_chain_destroy can sleep, it can't be used from call_rcu callbacks. Moreover, nf_tables_rule_release() is only safe for error unwinding, while transaction mutex is held and the to-be-desroyed rule was not exposed to either dataplane or dumps, as it deactives+frees without the required synchronize_rcu() in-between. nft_rule_expr_deactivate() callbacks will change ->use counters of other chains/sets, see e.g. nft_lookup .deactivate callback, these must be serialized via transaction mutex. Also add a few lockdep asserts to make this more explicit. Calling synchronize_rcu() isn't ideal, but fixing this without is hard and way more intrusive. As-is, we can get: WARNING: .. net/netfilter/nf_tables_api.c:5515 nft_set_destroy+0x.. Workqueue: events nf_tables_trans_destroy_work RIP: 0010:nft_set_destroy+0x3fe/0x5c0 Call Trace: <TASK> nf_tables_trans_destroy_work+0x6b7/0xad0 process_one_work+0x64a/0xce0 worker_thread+0x613/0x10d0 In case the synchronize_rcu becomes an issue, we can explore alternatives. One way would be to allocate nft_trans_rule objects + one nft_trans_chain object, deactivate the rules + the chain and then defer the freeing to the nft destroy workqueue. We'd still need to keep the synchronize_rcu path as a fallback to handle -ENOMEM corner cases though. Reported-by: syzbot+b26935466701e56cfdc2@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/67478d92.050a0220.253251.0062.GAE@google.com/T/ Fixes: c03d278fdf35 ("netfilter: nf_tables: wait for rcu grace period on net_device removal") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-11-14netfilter: nf_tables: allocate element update information dynamicallyFlorian Westphal
Move the timeout/expire/flag members from nft_trans_one_elem struct into a dybamically allocated structure, only needed when timeout update was requested. This halves size of nft_trans_one_elem struct and allows to compact up to 124 elements in one transaction container rather than 62. This halves memory requirements for a large flush or insert transaction, where ->update remains NULL. Care has to be taken to release the extra data in all spots, including abort path. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-11-14netfilter: nf_tables: prepare for multiple elements in nft_trans_elem structureFlorian Westphal
Add helpers to release the individual elements contained in the trans_elem container structure. No functional change intended. Followup patch will add 'nelems' member and will turn 'priv' into a flexible array. These helpers can then loop over all elements. Care needs to be taken to handle a mix of new elements and existing elements that are being updated (e.g. timeout refresh). Before this patch, NEWSETELEM transaction with update is released early so nft_trans_set_elem_destroy() won't get called, so we need to skip elements marked as update. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-11-07Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-6.12-rc7). Conflicts: drivers/net/ethernet/freescale/enetc/enetc_pf.c e15c5506dd39 ("net: enetc: allocate vf_state during PF probes") 3774409fd4c6 ("net: enetc: build enetc_pf_common.c as a separate module") https://lore.kernel.org/20241105114100.118bd35e@canb.auug.org.au Adjacent changes: drivers/net/ethernet/ti/am65-cpsw-nuss.c de794169cf17 ("net: ethernet: ti: am65-cpsw: Fix multi queue Rx on J7") 4a7b2ba94a59 ("net: ethernet: ti: am65-cpsw: Use tstats instead of open coded version") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-07netfilter: nf_tables: wait for rcu grace period on net_device removalPablo Neira Ayuso
8c873e219970 ("netfilter: core: free hooks with call_rcu") removed synchronize_net() call when unregistering basechain hook, however, net_device removal event handler for the NFPROTO_NETDEV was not updated to wait for RCU grace period. Note that 835b803377f5 ("netfilter: nf_tables_netdev: unregister hooks on net_device removal") does not remove basechain rules on device removal, I was hinted to remove rules on net_device removal later, see 5ebe0b0eec9d ("netfilter: nf_tables: destroy basechain and rules on netdevice removal"). Although NETDEV_UNREGISTER event is guaranteed to be handled after synchronize_net() call, this path needs to wait for rcu grace period via rcu callback to release basechain hooks if netns is alive because an ongoing netlink dump could be in progress (sockets hold a reference on the netns). Note that nf_tables_pre_exit_net() unregisters and releases basechain hooks but it is possible to see NETDEV_UNREGISTER at a later stage in the netns exit path, eg. veth peer device in another netns: cleanup_net() default_device_exit_batch() unregister_netdevice_many_notify() notifier_call_chain() nf_tables_netdev_event() __nft_release_basechain() In this particular case, same rule of thumb applies: if netns is alive, then wait for rcu grace period because netlink dump in the other netns could be in progress. Otherwise, if the other netns is going away then no netlink dump can be in progress and basechain hooks can be released inmediately. While at it, turn WARN_ON() into WARN_ON_ONCE() for the basechain validation, which should not ever happen. Fixes: 835b803377f5 ("netfilter: nf_tables_netdev: unregister hooks on net_device removal") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-11-05netfilter: nf_tables: avoid false-positive lockdep splats with flowtablesFlorian Westphal
The transaction mutex prevents concurrent add/delete, its ok to iterate those lists outside of rcu read side critical sections. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-10-02move asm/unaligned.h to linux/unaligned.hAl Viro
asm/unaligned.h is always an include of asm-generic/unaligned.h; might as well move that thing to linux/unaligned.h and include that - there's nothing arch-specific in that header. auto-generated by the following: for i in `git grep -l -w asm/unaligned.h`; do sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i done for i in `git grep -l -w asm-generic/unaligned.h`; do sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i done git mv include/asm-generic/unaligned.h include/linux/unaligned.h git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h
2024-09-03netfilter: nf_tables: set element timeout update supportPablo Neira Ayuso
Store new timeout and expiration in transaction object, use them to update elements from .commit path. Otherwise, discard update if .abort path is exercised. Use update_flags in the transaction to note whether the timeout, expiration, or both need to be updated. Annotate access to timeout extension now that it can be updated while lockless read access is possible. Reject timeout updates on elements with no timeout extension. Element transaction remains in the 96 bytes kmalloc slab on x86_64 after this update. This patch requires ("netfilter: nf_tables: use timestamp to check for set element timeout") to make sure an element does not expire while transaction is ongoing. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-09-03netfilter: nf_tables: zero timeout means element never times outPablo Neira Ayuso
This patch uses zero as timeout marker for those elements that never expire when the element is created. If userspace provides no timeout for an element, then the default set timeout applies. However, if no default set timeout is specified and timeout flag is set on, then timeout extension is allocated and timeout is set to zero to allow for future updates. Use of zero a never timeout marker has been suggested by Phil Sutter. Note that, in older kernels, it is already possible to define elements that never expire by declaring a set with the set timeout flag set on and no global set timeout, in this case, new element with no explicit timeout never expire do not allocate the timeout extension, hence, they never expire. This approach makes it complicated to accomodate element timeout update, because element extensions do not support reallocations. Therefore, allocate the timeout extension and use the new marker for this case, but do not expose it to userspace to retain backward compatibility in the set listing. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-09-03netfilter: nf_tables: consolidate timeout extension for elementsPablo Neira Ayuso
Expiration and timeout are stored in separated set element extensions, but they are tightly coupled. Consolidate them in a single extension to simplify and prepare for set element updates. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-09-03netfilter: nf_tables: annotate data-races around element expirationPablo Neira Ayuso
element expiration can be read-write locklessly, it can be written by dynset and read from netlink dump, add annotation. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-09-03netfilter: nf_tables: Add missing Kernel docSimon Horman
- Add missing documentation of struct field and enum items. - Add missing documentation of function parameter. Flagged by ./scripts/kernel-doc -none. No functional change intended. Compile tested only. Signed-off-by: Simon Horman <horms@kernel.org> Reviewed-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-09-03netfilter: nf_tables: Correct spelling in nf_tables.hSimon Horman
Correct spelling in nf_tables.h. As reported by codespell. Signed-off-by: Simon Horman <horms@kernel.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-09-03netfilter: nf_tables: drop unused 3rd argument from validate callback opsFlorian Westphal
Since commit a654de8fdc18 ("netfilter: nf_tables: fix chain dependency validation") the validate() callback no longer needs the return pointer argument. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-08-20netfilter: nf_tables: allow loads only when register is initializedFlorian Westphal
Reject rules where a load occurs from a register that has not seen a store early in the same rule. commit 4c905f6740a3 ("netfilter: nf_tables: initialize registers in nft_do_chain()") had to add a unconditional memset to the nftables register space to avoid leaking stack information to userspace. This memset shows up in benchmarks. After this change, this commit can be reverted again. Note that this breaks userspace compatibility, because theoretically you can do rule 1: reg2 := meta load iif, reg2 == 1 jump ... rule 2: reg2 == 2 jump ... // read access with no store in this rule ... after this change this is rejected. Neither nftables nor iptables-nft generate such rules, each rule is always standalone. This resuts in a small increase of nft_ctx structure by sizeof(long). To cope with hypothetical rulesets like the example above one could emit on-demand "reg[x] = 0" store when generating the datapath blob in nf_tables_commit_chain_prepare(). A patch that does this is linked to below. For now, lets disable this. In nf_tables, a rule is the smallest unit that can be replaced from userspace, i.e. a hypothetical ruleset that relies on earlier initialisations of registers can't be changed at will as register usage would need to be coordinated. Link: https://lore.kernel.org/netfilter-devel/20240627135330.17039-4-fw@strlen.de/ Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-08-20netfilter: nf_tables: pass context structure to nft_parse_register_loadFlorian Westphal
Mechanical transformation, no logical changes intended. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-08-19netfilter: nf_tables: store new sets in dedicated listFlorian Westphal
nft_set_lookup_byid() is very slow when transaction becomes large, due to walk of the transaction list. Add a dedicated list that contains only the new sets. Before: nft -f ruleset 0.07s user 0.00s system 0% cpu 1:04.84 total After: nft -f ruleset 0.07s user 0.00s system 0% cpu 30.115 total .. where ruleset contains ~10 sets with ~100k elements. The above number is for a combined flush+reload of the ruleset. With previous flush, even the first NEWELEM has to walk through a few hundred thousands of DELSET(ELEM) transactions before the first NEWSET object. To cope with random-order-newset-newsetelem we'd need to replace commit_set_list with a hashtable. Expectation is that a NEWELEM operation refers to the most recently added set, so last entry of the dedicated list should be the set we want. NB: This is not a bug fix per se (functionality is fine), but with larger transaction batches list search takes forever, so it would be nice to speed this up for -stable too, hence adding a "fixes" tag. Fixes: 958bee14d071 ("netfilter: nf_tables: use new transaction infrastructure to handle sets") Reported-by: Nadia Pinaeva <n.m.pinaeva@gmail.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-07-01Merge tag 'nf-next-24-06-28' of ↵David S. Miller
git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next into main Pablo Neira Ayuso says: ==================== Netfilter/IPVS updates for net-next The following patchset contains Netfilter/IPVS updates for net-next: Patch #1 to #11 to shrink memory consumption for transaction objects: struct nft_trans_chain { /* size: 120 (-32), cachelines: 2, members: 10 */ struct nft_trans_elem { /* size: 72 (-40), cachelines: 2, members: 4 */ struct nft_trans_flowtable { /* size: 80 (-48), cachelines: 2, members: 5 */ struct nft_trans_obj { /* size: 72 (-40), cachelines: 2, members: 4 */ struct nft_trans_rule { /* size: 80 (-32), cachelines: 2, members: 6 */ struct nft_trans_set { /* size: 96 (-24), cachelines: 2, members: 8 */ struct nft_trans_table { /* size: 56 (-40), cachelines: 1, members: 2 */ struct nft_trans_elem can now be allocated from kmalloc-96 instead of kmalloc-128 slab. Series from Florian Westphal. For the record, I have mangled patch #1 to add nft_trans_container_*() and use if for every transaction object. I have also added BUILD_BUG_ON to ensure struct nft_trans always comes at the beginning of the container transaction object. And few minor cleanups, any new bugs are of my own. Patch #12 simplify check for SCTP GSO in IPVS, from Ismael Luceno. Patch #13 nf_conncount key length remains in the u32 bound, from Yunjian Wang. Patch #14 removes unnecessary check for CTA_TIMEOUT_L3PROTO when setting default conntrack timeouts via nfnetlink_cttimeout API, from Lin Ma. Patch #15 updates NFT_SECMARK_CTX_MAXLEN to 4096, SELinux could use larger secctx names than the existing 256 bytes length. Patch #16 adds a selftest to exercise nfnetlink_queue listeners leaving nfnetlink_queue, from Florian Westphal. Patch #17 increases hitcount from 255 to 65535 in xt_recent, from Phil Sutter. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2024-06-27netfilter: nf_tables: fully validate NFT_DATA_VALUE on store to data registersPablo Neira Ayuso
register store validation for NFT_DATA_VALUE is conditional, however, the datatype is always either NFT_DATA_VALUE or NFT_DATA_VERDICT. This only requires a new helper function to infer the register type from the set datatype so this conditional check can be removed. Otherwise, pointer to chain object can be leaked through the registers. Fixes: 96518518cc41 ("netfilter: add nftables") Reported-by: Linus Torvalds <torvalds@linuxfoundation.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-06-25netfilter: nf_tables: do not store nft_ctx in transaction objectsFlorian Westphal
nft_ctx is huge and most of the information stored within isn't used at all. Remove nft_ctx member from the base transaction structure and store only what is needed. After this change, relevant struct sizes are: struct nft_trans_chain { /* size: 120 (-32), cachelines: 2, members: 10 */ struct nft_trans_elem { /* size: 72 (-40), cachelines: 2, members: 4 */ struct nft_trans_flowtable { /* size: 80 (-48), cachelines: 2, members: 5 */ struct nft_trans_obj { /* size: 72 (-40), cachelines: 2, members: 4 */ struct nft_trans_rule { /* size: 80 (-32), cachelines: 2, members: 6 */ struct nft_trans_set { /* size: 96 (-24), cachelines: 2, members: 8 */ struct nft_trans_table { /* size: 56 (-40), cachelines: 1, members: 2 */ struct nft_trans_elem can now be allocated from kmalloc-96 instead of kmalloc-128 slab. A further reduction by 8 bytes would even allow for kmalloc-64. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-06-25netfilter: nf_tables: store chain pointer in rule transactionFlorian Westphal
Currently the chain can be derived from trans->ctx.chain, but the ctx will go away soon. Thus add the chain pointer to nft_trans_rule structure itself. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-06-25netfilter: nf_tables: pass nft_chain to destroy function, not nft_ctxFlorian Westphal
It would be better to not store nft_ctx inside nft_trans object, the netlink ctx strucutre is huge and most of its information is never needed in places that use trans->ctx. Avoid/reduce its usage if possible, no runtime behaviour change intended. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-06-25netfilter: nf_tables: compact chain+ft transaction objectsFlorian Westphal
Cover holes to reduce both structures by 8 byte. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-06-25netfilter: nf_tables: move bind list_head into relevant subtypesFlorian Westphal
Only nft_trans_chain and nft_trans_set subtypes use the trans->binding_list member. Add a new common binding subtype and move the member there. This reduces size of all other subtypes by 16 bytes on 64bit platforms. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-06-25netfilter: nf_tables: make struct nft_trans first member of derived subtypesFlorian Westphal
There is 'struct nft_trans', the basic structure for all transactional objects, and the the various different transactional objects, such as nft_trans_table, chain, set, set_elem and so on. Right now 'struct nft_trans' uses a flexible member at the tail (data[]), and casting is needed to access the actual type-specific members. Change this to make the hierarchy visible in source code, i.e. make struct nft_trans the first member of all derived subtypes. This has several advantages: 1. pahole output reflects the real size needed by the particular subtype 2. allows to use container_of() to convert the base type to the actual object type instead of casting ->data to the overlay structure. 3. It makes it easy to add intermediate types. 'struct nft_trans' contains a 'binding_list' that is only needed by two subtypes, so it should be part of the two subtypes, not in the base structure. But that makes it hard to interate over the binding_list, because there is no common base structure. A follow patch moves the bind list to a new struct: struct nft_trans_binding { struct nft_trans nft_trans; struct list_head binding_list; }; ... and makes that structure the new 'first member' for both nft_trans_chain and nft_trans_set. No functional change intended in this patch. Some numbers: struct nft_trans { /* size: 88, cachelines: 2, members: 5 */ struct nft_trans_chain { /* size: 152, cachelines: 3, members: 10 */ struct nft_trans_elem { /* size: 112, cachelines: 2, members: 4 */ struct nft_trans_flowtable { /* size: 128, cachelines: 2, members: 5 */ struct nft_trans_obj { /* size: 112, cachelines: 2, members: 4 */ struct nft_trans_rule { /* size: 112, cachelines: 2, members: 5 */ struct nft_trans_set { /* size: 120, cachelines: 2, members: 8 */ struct nft_trans_table { /* size: 96, cachelines: 2, members: 2 */ Of particular interest is nft_trans_elem, which needs to be allocated once for each pending (to be added or removed) set element. Add BUILD_BUG_ON to check struct nft_trans is placed at the top of the container structure. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-05-10netfilter: nf_tables: allow clone callbacks to sleepFlorian Westphal
Sven Auhagen reports transaction failures with following error: ./main.nft:13:1-26: Error: Could not process rule: Cannot allocate memory percpu: allocation failed, size=16 align=8 atomic=1, atomic alloc failed, no space left This points to failing pcpu allocation with GFP_ATOMIC flag. However, transactions happen from user context and are allowed to sleep. One case where we can call into percpu allocator with GFP_ATOMIC is nft_counter expression. Normally this happens from control plane, so this could use GFP_KERNEL instead. But one use case, element insertion from packet path, needs to use GFP_ATOMIC allocations (nft_dynset expression). At this time, .clone callbacks always use GFP_ATOMIC for this reason. Add gfp_t argument to the .clone function and pass GFP_KERNEL or GFP_ATOMIC flag depending on context, this allows all clone memory allocations to sleep for the normal (transaction) case. Cc: Sven Auhagen <sven.auhagen@voleatech.de> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-04-11netfilter: nft_set_pipapo: walk over current view on netlink dumpPablo Neira Ayuso
The generation mask can be updated while netlink dump is in progress. The pipapo set backend walk iterator cannot rely on it to infer what view of the datastructure is to be used. Add notation to specify if user wants to read/update the set. Based on patch from Florian Westphal. Fixes: 2b84e215f874 ("netfilter: nft_set_pipapo: .walk does not deal with generations") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-02-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR. No conflicts. Adjacent changes: drivers/net/ethernet/stmicro/stmmac/common.h 38cc3c6dcc09 ("net: stmmac: protect updates of 64-bit statistics counters") fd5a6a71313e ("net: stmmac: est: Per Tx-queue error count for HLBF") c5c3e1bfc9e0 ("net: stmmac: Offload queueMaxSDU from tc-taprio") drivers/net/wireless/microchip/wilc1000/netdev.c c9013880284d ("wifi: fill in MODULE_DESCRIPTION()s for wilc1000") 328efda22af8 ("wifi: wilc1000: do not realloc workqueue everytime an interface is added") net/unix/garbage.c 11498715f266 ("af_unix: Remove io_uring code for GC.") 1279f9d9dec2 ("af_unix: Call kfree_skb() for dead unix_(sk)->oob_skb in GC.") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-02-08netfilter: nf_tables: use timestamp to check for set element timeoutPablo Neira Ayuso
Add a timestamp field at the beginning of the transaction, store it in the nftables per-netns area. Update set backend .insert, .deactivate and sync gc path to use the timestamp, this avoids that an element expires while control plane transaction is still unfinished. .lookup and .update, which are used from packet path, still use the current time to check if the element has expired. And .get path and dump also since this runs lockless under rcu read size lock. Then, there is async gc which also needs to check the current time since it runs asynchronously from a workqueue. Fixes: c3e1b005ed1c ("netfilter: nf_tables: add set element timeout support") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-02-01Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR. No conflicts or adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-31netfilter: nf_tables: restrict tunnel object to NFPROTO_NETDEVPablo Neira Ayuso
Bail out on using the tunnel dst template from other than netdev family. Add the infrastructure to check for the family in objects. Fixes: af308b94a2a4 ("netfilter: nf_tables: add tunnel support") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-01-29netfilter: nf_tables: Implement table adoption supportPhil Sutter
Allow a new process to take ownership of a previously owned table, useful mostly for firewall management services restarting or suspending when idle. By extending __NFT_TABLE_F_UPDATE, the on/off/on check in nf_tables_updtable() also covers table adoption, although it is actually not needed: Table adoption is irreversible because nf_tables_updtable() rejects attempts to drop NFT_TABLE_F_OWNER so table->nlpid setting can happen just once within the transaction. If the transaction commences, table's nlpid and flags fields are already set and no further action is required. If it aborts, the table returns to orphaned state. Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Florian Westphal <fw@strlen.de>
2024-01-24netfilter: nf_tables: cleanup documentationGeorge Guo
- Correct comments for nlpid, family, udlen and udata in struct nft_table, and afinfo is no longer a member of enum nft_set_class. - Add comment for data in struct nft_set_elem. - Add comment for flags in struct nft_ctx. - Add comments for timeout in struct nft_set_iter, and flags is not a member of struct nft_set_iter, remove the comment for it. - Add comments for commit, abort, estimate and gc_init in struct nft_set_ops. - Add comments for pending_update, num_exprs, exprs and catchall_list in struct nft_set. - Add comment for ext_len in struct nft_set_ext_tmpl. - Add comment for inner_ops in struct nft_expr_type. - Add comments for clone, destroy_clone, reduce, gc, offload, offload_action, offload_stats in struct nft_expr_ops. - Add comments for blob_gen_0, blob_gen_1, bound, genmask, udlen, udata, blob_next in struct nft_chain. - Add comment for flags in struct nft_base_chain. - Add comments for udlen, udata in struct nft_object. - Add comment for type in struct nft_object_ops. - Add comment for hook_list in struct nft_flowtable, and remove comments for dev_name and ops which are not members of struct nft_flowtable. Signed-off-by: George Guo <guodongtai@kylinos.cn> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-11-14netfilter: nf_tables: fix pointer math issue in nft_byteorder_eval()Dan Carpenter
The problem is in nft_byteorder_eval() where we are iterating through a loop and writing to dst[0], dst[1], dst[2] and so on... On each iteration we are writing 8 bytes. But dst[] is an array of u32 so each element only has space for 4 bytes. That means that every iteration overwrites part of the previous element. I spotted this bug while reviewing commit caf3ef7468f7 ("netfilter: nf_tables: prevent OOB access in nft_byteorder_eval") which is a related issue. I think that the reason we have not detected this bug in testing is that most of time we only write one element. Fixes: ce1e7989d989 ("netfilter: nft_byteorder: provide 64bit le/be conversion") Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-10-24netfilter: nf_tables: set->ops->insert returns opaque set element in case of ↵Pablo Neira Ayuso
EEXIST Return struct nft_elem_priv instead of struct nft_set_ext for consistency with ("netfilter: nf_tables: expose opaque set element as struct nft_elem_priv") and to prepare the introduction of element timeout updates from control path. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-10-24netfilter: nf_tables: shrink memory consumption of set elementsPablo Neira Ayuso
Instead of copying struct nft_set_elem into struct nft_trans_elem, store the pointer to the opaque set element object in the transaction. Adapt set backend API (and set backend implementations) to take the pointer to opaque set element representation whenever required. This patch deconstifies .remove() and .activate() set backend API since these modify the set element opaque object. And it also constify nft_set_elem_ext() this provides access to the nft_set_ext struct without updating the object. According to pahole on x86_64, this patch shrinks struct nft_trans_elem size from 216 to 24 bytes. This patch also reduces stack memory consumption by removing the template struct nft_set_elem object, using the opaque set element object instead such as from the set iterator API, catchall elements and the get element command. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-10-24netfilter: nf_tables: expose opaque set element as struct nft_elem_privPablo Neira Ayuso
Add placeholder structure and place it at the beginning of each struct nft_*_elem for each existing set backend, instead of exposing elements as void type to the frontend which defeats compiler type checks. Use this pointer to this new type to replace void *. This patch updates the following set backend API to use this new struct nft_elem_priv placeholder structure: - update - deactivate - flush - get as well as the following helper functions: - nft_set_elem_ext() - nft_set_elem_init() - nft_set_elem_destroy() - nf_tables_set_elem_destroy() This patch adds nft_elem_priv_cast() to cast struct nft_elem_priv to native element representation from the corresponding set backend. BUILD_BUG_ON() makes sure this .priv placeholder is always at the top of the opaque set element representation. Suggested-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-10-24netfilter: nf_tables: set backend .flush always succeedsPablo Neira Ayuso
.flush is always successful since this results from iterating over the set elements to toggle mark the element as inactive in the next generation. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2023-10-18netfilter: nf_tables: de-constify set commit ops function argumentFlorian Westphal
The set backend using this already has to work around this via ugly cast, don't spread this pattern. Signed-off-by: Florian Westphal <fw@strlen.de>
2023-10-10netfilter: cleanup struct nft_tableGeorge Guo
Add comments for nlpid, family, udlen and udata in struct nft_table, and afinfo is no longer a member of struct nft_table, so remove the comment for it. Signed-off-by: George Guo <guodongtai@kylinos.cn> Signed-off-by: Florian Westphal <fw@strlen.de>
2023-09-20netfilter: nf_tables: fix memleak when more than 255 elements expiredFlorian Westphal
When more than 255 elements expired we're supposed to switch to a new gc container structure. This never happens: u8 type will wrap before reaching the boundary and nft_trans_gc_space() always returns true. This means we recycle the initial gc container structure and lose track of the elements that came before. While at it, don't deref 'gc' after we've passed it to call_rcu. Fixes: 5f68718b34a5 ("netfilter: nf_tables: GC transaction API to avoid race with control plane") Reported-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Florian Westphal <fw@strlen.de>
2023-09-08netfilter: nft_set_pipapo: call nft_trans_gc_queue_sync() in catchall GCPablo Neira Ayuso
pipapo needs to enqueue GC transactions for catchall elements through nft_trans_gc_queue_sync(). Add nft_trans_gc_catchall_sync() and nft_trans_gc_catchall_async() to handle GC transaction queueing accordingly. Fixes: 5f68718b34a5 ("netfilter: nf_tables: GC transaction API to avoid race with control plane") Fixes: f6c383b8c31a ("netfilter: nf_tables: adapt set backend to use GC transaction API") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>