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2024-01-17netfilter: propagate net to nf_bridge_get_physindevPavel Tikhomirov
This is a preparation patch for replacing physindev with physinif on nf_bridge_info structure. We will use dev_get_by_index_rcu to resolve device, when needed, and it requires net to be available. Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2024-01-17netfilter: nf_queue: remove excess nf_bridge variablePavel Tikhomirov
We don't really need nf_bridge variable here. And nf_bridge_info_exists is better replacement for nf_bridge_info_get in case we are only checking for existence. Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2022-03-01netfilter: nf_queue: handle socket prefetchFlorian Westphal
In case someone combines bpf socket assign and nf_queue, then we will queue an skb who references a struct sock that did not have its reference count incremented. As we leave rcu protection, there is no guarantee that skb->sk is still valid. For refcount-less skb->sk case, try to increment the reference count and then override the destructor. In case of failure we have two choices: orphan the skb and 'delete' preselect or let nf_queue() drop the packet. Do the latter, it should not happen during normal operation. Fixes: cf7fbe660f2d ("bpf: Add socket assign support") Acked-by: Joe Stringer <joe@cilium.io> Signed-off-by: Florian Westphal <fw@strlen.de>
2022-03-01netfilter: nf_queue: fix possible use-after-freeFlorian Westphal
Eric Dumazet says: The sock_hold() side seems suspect, because there is no guarantee that sk_refcnt is not already 0. On failure, we cannot queue the packet and need to indicate an error. The packet will be dropped by the caller. v2: split skb prefetch hunk into separate change Fixes: 271b72c7fa82c ("udp: RCU handling for Unicast packets.") Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Florian Westphal <fw@strlen.de>
2022-03-01netfilter: nf_queue: don't assume sk is full socketFlorian Westphal
There is no guarantee that state->sk refers to a full socket. If refcount transitions to 0, sock_put calls sk_free which then ends up with garbage fields. I'd like to thank Oleksandr Natalenko and Jiri Benc for considerable debug work and pointing out state->sk oddities. Fixes: ca6fb0651883 ("tcp: attach SYNACK messages to request sockets instead of listener") Tested-by: Oleksandr Natalenko <oleksandr@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de>
2021-08-11Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-nextDavid S. Miller
Pablo Neira Ayuso says: ==================== Netfilter updates for net-next The following patchset contains Netfilter updates for net-next: 1) Use nfnetlink_unicast() instead of netlink_unicast() in nft_compat. 2) Remove call to nf_ct_l4proto_find() in flowtable offload timeout fixup. 3) CLUSTERIP registers ARP hook on demand, from Florian. 4) Use clusterip_net to store pernet warning, also from Florian. 5) Remove struct netns_xt, from Florian Westphal. 6) Enable ebtables hooks in initns on demand, from Florian. 7) Allow to filter conntrack netlink dump per status bits, from Florian Westphal. 8) Register x_tables hooks in initns on demand, from Florian. 9) Remove queue_handler from per-netns structure, again from Florian. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-10netfilter: nf_queue: move hookfn registration out of struct netFlorian Westphal
This was done to detect when the pernet->init() function was not called yet, by checking if net->nf.queue_handler is NULL. Once the nfnetlink_queue module is active, all struct net pointers contain the same address. So place this back in nf_queue.c. Handle the 'netns error unwind' test by checking nfnl_queue_net for a NULL pointer and add a comment for this. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2021-08-05net: Remove redundant if statementsYajun Deng
The 'if (dev)' statement already move into dev_{put , hold}, so remove redundant if statements. Signed-off-by: Yajun Deng <yajun.deng@linux.dev> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29netfilter: nf_queue: prefer nf_queue_entry_freeFlorian Westphal
Instead of dropping refs+kfree, use the helper added in previous patch. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-03-29netfilter: nf_queue: do not release refcouts until nf_reinject is doneFlorian Westphal
nf_queue is problematic when another NF_QUEUE invocation happens from nf_reinject(). 1. nf_queue is invoked, increments state->sk refcount. 2. skb is queued, waiting for verdict. 3. sk is closed/released. 3. verdict comes back, nf_reinject is called. 4. nf_reinject drops the reference -- refcount can now drop to 0 Instead of get_ref/release_ref pattern, we need to nest the get_ref calls: get_ref get_ref release_ref release_ref So that when we invoke the next processing stage (another netfilter or the okfn()), we hold at least one reference count on the devices/socket. After previous patch, it is now safe to put the entry even after okfn() has potentially free'd the skb. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-03-29netfilter: nf_queue: place bridge physports into queue_entry structFlorian Westphal
The refcount is done via entry->skb, which does work fine. Major problem: When putting the refcount of the bridge ports, we must always put the references while the skb is still around. However, we will need to put the references after okfn() to avoid a possible 1 -> 0 -> 1 refcount transition, so we cannot use the skb pointer anymore. Place the physports in the queue entry structure instead to allow for refcounting changes in the next patch. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-03-29netfilter: nf_queue: make nf_queue_entry_release_refs staticFlorian Westphal
This is a preparation patch, no logical changes. Move free_entry into core and rename it to something more sensible. Will ease followup patches which will complicate the refcount handling. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-12-07netfilter: nf_queue: enqueue skbs with NULL dstMarco Oliverio
Bridge packets that are forwarded have skb->dst == NULL and get dropped by the check introduced by b60a77386b1d4868f72f6353d35dabe5fbe981f2 (net: make skb_dst_force return true when dst is refcounted). To fix this we check skb_dst() before skb_dst_force(), so we don't drop skb packet with dst == NULL. This holds also for skb at the PRE_ROUTING hook so we remove the second check. Fixes: b60a77386b1d ("net: make skb_dst_force return true when dst is refcounted") Signed-off-by: Marco Oliverio <marco.oliverio@tanaza.com> Signed-off-by: Rocco Folino <rocco.folino@tanaza.com> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-07-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Two cases of overlapping changes, nothing fancy. Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-04netfilter: nf_queue: remove unused hook entries pointerFlorian Westphal
Its not used anywhere, so remove this. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-06-29net: make skb_dst_force return true when dst is refcountedFlorian Westphal
netfilter did not expect that skb_dst_force() can cause skb to lose its dst entry. I got a bug report with a skb->dst NULL dereference in netfilter output path. The backtrace contains nf_reinject(), so the dst might have been cleared when skb got queued to userspace. Other users were fixed via if (skb_dst(skb)) { skb_dst_force(skb); if (!skb_dst(skb)) goto handle_err; } But I think its preferable to make the 'dst might be cleared' part of the function explicit. In netfilter case, skb with a null dst is expected when queueing in prerouting hook, so drop skb for the other hooks. v2: v1 of this patch returned true in case skb had no dst entry. Eric said: Say if we have two skb_dst_force() calls for some reason on the same skb, only the first one will return false. This now returns false even when skb had no dst, as per Erics suggestion, so callers might need to check skb_dst() first before skb_dst_force(). Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-21netfilter: nf_queue: fix reinject verdict handlingJagdish Motwani
This patch fixes netfilter hook traversal when there are more than 1 hooks returning NF_QUEUE verdict. When the first queue reinjects the packet, 'nf_reinject' starts traversing hooks with a proper hook_index. However, if it again receives a NF_QUEUE verdict (by some other netfilter hook), it queues the packet with a wrong hook_index. So, when the second queue reinjects the packet, it re-executes hooks in between. Fixes: 960632ece694 ("netfilter: convert hook list to an array") Signed-off-by: Jagdish Motwani <jagdish.motwani@sophos.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-04-12bridge: netfilter: unroll NF_HOOK helper in bridge input pathFlorian Westphal
Replace NF_HOOK() based invocation of the netfilter hooks with a private copy of nf_hook_slow(). This copy has one difference: it can return the rx handler value expected by the stack, i.e. RX_HANDLER_CONSUMED or RX_HANDLER_PASS. This is needed by the next patch to invoke the ebtables "broute" table via the standard netfilter hooks rather than the custom "br_should_route_hook" indirection that is used now. When the skb is to be "brouted", we must return RX_HANDLER_PASS from the bridge rx input handler, but there is no way to indicate this via NF_HOOK(), unless perhaps by some hack such as exposing bridge_cb in the netfilter core or a percpu flag. text data bss dec filename 3369 56 0 3425 net/bridge/br_input.o.before 3458 40 0 3498 net/bridge/br_input.o.after This allows removal of the "br_should_route_hook" in the next patch. Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-12-19netfilter: avoid using skb->nf_bridge directlyFlorian Westphal
This pointer is going to be removed soon, so use the existing helpers in more places to avoid noise when the removal happens. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-01-10netfilter: remove duplicated includeWei Yongjun
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-01-08netfilter: remove route_key_size field in struct nf_afinfoPablo Neira Ayuso
This is only needed by nf_queue, place this code where it belongs. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-01-08netfilter: move reroute indirection to struct nf_ipv6_opsPablo Neira Ayuso
We cannot make a direct call to nf_ip6_reroute() because that would result in autoloading the 'ipv6' module because of symbol dependencies. Therefore, define reroute indirection in nf_ipv6_ops where this really belongs to. For IPv4, we can indeed make a direct function call, which is faster, given IPv4 is built-in in the networking code by default. Still, CONFIG_INET=n and CONFIG_NETFILTER=y is possible, so define empty inline stub for IPv4 in such case. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-01-08netfilter: remove saveroute indirection in struct nf_afinfoPablo Neira Ayuso
This is only used by nf_queue.c and this function comes with no symbol dependencies with IPv6, it just refers to structure layouts. Therefore, we can replace it by a direct function call from where it belongs. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-01-08netfilter: don't allocate space for arp/bridge hooks unless neededFlorian Westphal
no need to define hook points if the family isn't supported. Because we need these hooks for either nftables, arp/ebtables or the 'call-iptables' hack we have in the bridge layer add two new dependencies, NETFILTER_FAMILY_{ARP,BRIDGE}, and have the users select them. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-01-08netfilter: reduce size of hook entry point locationsFlorian Westphal
struct net contains: struct nf_hook_entries __rcu *hooks[NFPROTO_NUMPROTO][NF_MAX_HOOKS]; which store the hook entry point locations for the various protocol families and the hooks. Using array results in compact c code when doing accesses, i.e. x = rcu_dereference(net->nf.hooks[pf][hook]); but its also wasting a lot of memory, as most families are not used. So split the array into those families that are used, which are only 5 (instead of 13). In most cases, the 'pf' argument is constant, i.e. gcc removes switch statement. struct net before: /* size: 5184, cachelines: 81, members: 46 */ after: /* size: 4672, cachelines: 73, members: 46 */ Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2018-01-08netfilter: core: remove synchronize_net call if nfqueue is usedFlorian Westphal
since commit 960632ece6949b ("netfilter: convert hook list to an array") nfqueue no longer stores a pointer to the hook that caused the packet to be queued. Therefore no extra synchronize_net() call is needed after dropping the packets enqueued by the old rule blob. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-08-28netfilter: convert hook list to an arrayAaron Conole
This converts the storage and layout of netfilter hook entries from a linked list to an array. After this commit, hook entries will be stored adjacent in memory. The next pointer is no longer required. The ops pointers are stored at the end of the array as they are only used in the register/unregister path and in the legacy br_netfilter code. nf_unregister_net_hooks() is slower than needed as it just calls nf_unregister_net_hook in a loop (i.e. at least n synchronize_net() calls), this will be addressed in followup patch. Test setup: - ixgbe 10gbit - netperf UDP_STREAM, 64 byte packets - 5 hooks: (raw + mangle prerouting, mangle+filter input, inet filter): empty mangle and raw prerouting, mangle and filter input hooks: 353.9 this patch: 364.2 Signed-off-by: Aaron Conole <aconole@bytheb.org> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-07-31netfilter: conntrack: destroy functions need to free queued packetsFlorian Westphal
queued skbs might be using conntrack extensions that are being removed, such as timeout. This happens for skbs that have a skb->nfct in unconfirmed state (i.e., not in hash table yet). This is destructive, but there are only two use cases: - module removal (rare) - netns cleanup (most likely no conntracks exist, and if they do, they are removed anyway later on). Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2017-05-01netfilter: nf_queue: only call synchronize_net twice if nf_queue is activeFlorian Westphal
nf_unregister_net_hook(s) can avoid a second call to synchronize_net, provided there is no nfqueue active in that net namespace (which is the common case). This also gets rid of the extra arg to nf_queue_nf_hook_drop(), normally this gets called during netns cleanup so no packets should be queued. For the rare case of base chain being unregistered or module removal while nfqueue is in use the extra hiccup due to the packet drops isn't a big deal. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-12-06netfilter: introduce accessor functions for hook entriesAaron Conole
This allows easier future refactoring. Signed-off-by: Aaron Conole <aconole@bytheb.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-11-03netfilter: merge nf_iterate() into nf_hook_slow()Pablo Neira Ayuso
nf_iterate() has become rather simple, we can integrate this code into nf_hook_slow() to reduce the amount of LOC in the core path. However, we still need nf_iterate() around for nf_queue packet handling, so move this function there where we only need it. I think it should be possible to refactor nf_queue code to get rid of it definitely, but given this is slow path anyway, let's have a look this later. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-11-03netfilter: remove hook_entries field from nf_hook_statePablo Neira Ayuso
This field is only useful for nf_queue, so store it in the nf_queue_entry structure instead, away from the core path. Pass hook_head to nf_hook_slow(). Since we always have a valid entry on the first iteration in nf_iterate(), we can use 'do { ... } while (entry)' loop instead. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-11-03netfilter: kill NF_HOOK_THRESH() and state->treshPablo Neira Ayuso
Patch c5136b15ea36 ("netfilter: bridge: add and use br_nf_hook_thresh") introduced br_nf_hook_thresh(). Replace NF_HOOK_THRESH() by br_nf_hook_thresh from br_nf_forward_finish(), so we have no more callers for this macro. As a result, state->thresh and explicit thresh parameter in the hook state structure is not required anymore. And we can get rid of skip-hook-under-thresh loop in nf_iterate() in the core path that is only used by br_netfilter to search for the filter hook. Suggested-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-10-20netfilter: fix nf_queue handlingPablo Neira Ayuso
nf_queue handling is broken since e3b37f11e6e4 ("netfilter: replace list_head with single linked list") for two reasons: 1) If the bypass flag is set on, there are no userspace listeners and we still have more hook entries to iterate over, then jump to the next hook. Otherwise accept the packet. On nf_reinject() path, the okfn() needs to be invoked. 2) We should not re-enter the same hook on packet reinjection. If the packet is accepted, we have to skip the current hook from where the packet was enqueued, otherwise the packets gets enqueued over and over again. This restores the previous list_for_each_entry_continue() behaviour happening from nf_iterate() that was dealing with these two cases. This patch introduces a new nf_queue() wrapper function so this fix becomes simpler. Fixes: e3b37f11e6e4 ("netfilter: replace list_head with single linked list") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-09-25netfilter: replace list_head with single linked listAaron Conole
The netfilter hook list never uses the prev pointer, and so can be trimmed to be a simple singly-linked list. In addition to having a more light weight structure for hook traversal, struct net becomes 5568 bytes (down from 6400) and struct net_device becomes 2176 bytes (down from 2240). Signed-off-by: Aaron Conole <aconole@bytheb.org> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-05-25netfilter: nf_queue: Make the queue_handler pernetEric W. Biederman
Florian Weber reported: > Under full load (unshare() in loop -> OOM conditions) we can > get kernel panic: > > BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 > IP: [<ffffffff81476c85>] nfqnl_nf_hook_drop+0x35/0x70 > [..] > task: ffff88012dfa3840 ti: ffff88012dffc000 task.ti: ffff88012dffc000 > RIP: 0010:[<ffffffff81476c85>] [<ffffffff81476c85>] nfqnl_nf_hook_drop+0x35/0x70 > RSP: 0000:ffff88012dfffd80 EFLAGS: 00010206 > RAX: 0000000000000008 RBX: ffffffff81add0c0 RCX: ffff88013fd80000 > [..] > Call Trace: > [<ffffffff81474d98>] nf_queue_nf_hook_drop+0x18/0x20 > [<ffffffff814738eb>] nf_unregister_net_hook+0xdb/0x150 > [<ffffffff8147398f>] netfilter_net_exit+0x2f/0x60 > [<ffffffff8141b088>] ops_exit_list.isra.4+0x38/0x60 > [<ffffffff8141b652>] setup_net+0xc2/0x120 > [<ffffffff8141bd09>] copy_net_ns+0x79/0x120 > [<ffffffff8106965b>] create_new_namespaces+0x11b/0x1e0 > [<ffffffff810698a7>] unshare_nsproxy_namespaces+0x57/0xa0 > [<ffffffff8104baa2>] SyS_unshare+0x1b2/0x340 > [<ffffffff81608276>] entry_SYSCALL_64_fastpath+0x1e/0xa8 > Code: 65 00 48 89 e5 41 56 41 55 41 54 53 83 e8 01 48 8b 97 70 12 00 00 48 98 49 89 f4 4c 8b 74 c2 18 4d 8d 6e 08 49 81 c6 88 00 00 00 <49> 8b 5d 00 48 85 db 74 1a 48 89 df 4c 89 e2 48 c7 c6 90 68 47 > The simple fix for this requires a new pernet variable for struct nf_queue that indicates when it is safe to use the dynamically allocated nf_queue state. As we need a variable anyway make nf_register_queue_handler and nf_unregister_queue_handler pernet. This allows the existing logic of when it is safe to use the state from the nfnetlink_queue module to be reused with no changes except for making it per net. The syncrhonize_rcu from nf_unregister_queue_handler is moved to a new function nfnl_queue_net_exit_batch so that the worst case of having a syncrhonize_rcu in the pernet exit path is not experienced in batch mode. Reported-by: Florian Westphal <fw@strlen.de> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-10-16netfilter: nf_queue: remove rcu_read_lock callsFlorian Westphal
All verdict handlers make use of the nfnetlink .call_rcu callback so rcu readlock is already held. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-10-16netfilter: make nf_queue_entry_get_refs return voidFlorian Westphal
We don't care if module is being unloaded anymore since hook unregister handling will destroy queue entries using that hook. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-10-16netfilter: remove hook owner refcountingFlorian Westphal
since commit 8405a8fff3f8 ("netfilter: nf_qeueue: Drop queue entries on nf_unregister_hook") all pending queued entries are discarded. So we can simply remove all of the owner handling -- when module is removed it also needs to unregister all its hooks. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-10-13netfilter: nfqueue: don't use prev pointerFlorian Westphal
Usage of -prev seems buggy. While packet was out our hook cannot be removed but we have no way to know if the previous one is still valid. So better not use ->prev at all. Since NF_REPEAT just asks to invoke same hook function again, just do so, and continue with nf_interate if we get an ACCEPT verdict. A side effect of this change is that if nf_reinject(NF_REPEAT) causes another REPEAT we will now drop the skb instead of a kernel loop. However, NF_REPEAT loops would be a bug so this should not happen anyway. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-09-29netfilter: Push struct net down into nf_afinfo.rerouteEric W. Biederman
The network namespace is needed when routing a packet. Stop making nf_afinfo.reroute guess which network namespace is the proper namespace to route the packet in. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-09-17netfilter: Pass net into okfnEric W. Biederman
This is immediately motivated by the bridge code that chains functions that call into netfilter. Without passing net into the okfns the bridge code would need to guess about the best expression for the network namespace to process packets in. As net is frequently one of the first things computed in continuation functions after netfilter has done it's job passing in the desired network namespace is in many cases a code simplification. To support this change the function dst_output_okfn is introduced to simplify passing dst_output as an okfn. For the moment dst_output_okfn just silently drops the struct net. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-23netfilter: nf_queue: fix nf_queue_nf_hook_drop()Pablo Neira Ayuso
This function reacquires the rtnl_lock() which is already held by nf_unregister_hook(). This can be triggered via: modprobe nf_conntrack_ipv4 && rmmod nf_conntrack_ipv4 [ 720.628746] INFO: task rmmod:3578 blocked for more than 120 seconds. [ 720.628749] Not tainted 4.2.0-rc2+ #113 [ 720.628752] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 720.628754] rmmod D ffff8800ca46fd58 0 3578 3571 0x00000080 [...] [ 720.628783] Call Trace: [ 720.628790] [<ffffffff8152ea0b>] schedule+0x6b/0x90 [ 720.628795] [<ffffffff8152ecb3>] schedule_preempt_disabled+0x13/0x20 [ 720.628799] [<ffffffff8152ff55>] mutex_lock_nested+0x1f5/0x380 [ 720.628803] [<ffffffff81462622>] ? rtnl_lock+0x12/0x20 [ 720.628807] [<ffffffff81462622>] ? rtnl_lock+0x12/0x20 [ 720.628812] [<ffffffff81462622>] rtnl_lock+0x12/0x20 [ 720.628817] [<ffffffff8148ab25>] nf_queue_nf_hook_drop+0x15/0x160 [ 720.628825] [<ffffffff81488d48>] nf_unregister_net_hook+0x168/0x190 [ 720.628831] [<ffffffff81488e24>] nf_unregister_hook+0x64/0x80 [ 720.628837] [<ffffffff81488e60>] nf_unregister_hooks+0x20/0x30 [...] Moreover, nf_unregister_net_hook() should only destroy the queue for this netns, not for every netns. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Fixes: 085db2c04557 ("netfilter: Per network namespace netfilter hooks.") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
2015-07-02netfilter: nf_queue: Don't recompute the hook_list headEric W. Biederman
If someone sends packets from one of the netdevice ingress hooks to the a userspace queue, and then userspace later accepts the packet, the netfilter code can enter an infinite loop as the list head will never be found. Pass in the saved list_head to avoid this. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-06-23netfilter: nf_qeueue: Drop queue entries on nf_unregister_hookEric W. Biederman
Add code to nf_unregister_hook to flush the nf_queue when a hook is unregistered. This guarantees that the pointer that the nf_queue code retains into the nf_hook list will remain valid while a packet is queued. I tested what would happen if we do not flush queued packets and was trivially able to obtain the oops below. All that was required was to stop the nf_queue listening process, to delete all of the nf_tables, and to awaken the nf_queue listening process. > BUG: unable to handle kernel paging request at 0000000100000001 > IP: [<0000000100000001>] 0x100000001 > PGD b9c35067 PUD 0 > Oops: 0010 [#1] SMP > Modules linked in: > CPU: 0 PID: 519 Comm: lt-nfqnl_test Not tainted > task: ffff8800b9c8c050 ti: ffff8800ba9d8000 task.ti: ffff8800ba9d8000 > RIP: 0010:[<0000000100000001>] [<0000000100000001>] 0x100000001 > RSP: 0018:ffff8800ba9dba40 EFLAGS: 00010a16 > RAX: ffff8800bab48a00 RBX: ffff8800ba9dba90 RCX: ffff8800ba9dba90 > RDX: ffff8800b9c10128 RSI: ffff8800ba940900 RDI: ffff8800bab48a00 > RBP: ffff8800b9c10128 R08: ffffffff82976660 R09: ffff8800ba9dbb28 > R10: dead000000100100 R11: dead000000200200 R12: ffff8800ba940900 > R13: ffffffff8313fd50 R14: ffff8800b9c95200 R15: 0000000000000000 > FS: 00007fb91fc34700(0000) GS:ffff8800bfa00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000100000001 CR3: 00000000babfb000 CR4: 00000000000007f0 > Stack: > ffffffff8206ab0f ffffffff82982240 ffff8800bab48a00 ffff8800b9c100a8 > ffff8800b9c10100 0000000000000001 ffff8800ba940900 ffff8800b9c10128 > ffffffff8206bd65 ffff8800bfb0d5e0 ffff8800bab48a00 0000000000014dc0 > Call Trace: > [<ffffffff8206ab0f>] ? nf_iterate+0x4f/0xa0 > [<ffffffff8206bd65>] ? nf_reinject+0x125/0x190 > [<ffffffff8206dee5>] ? nfqnl_recv_verdict+0x255/0x360 > [<ffffffff81386290>] ? nla_parse+0x80/0xf0 > [<ffffffff8206c42c>] ? nfnetlink_rcv_msg+0x13c/0x240 > [<ffffffff811b2fec>] ? __memcg_kmem_get_cache+0x4c/0x150 > [<ffffffff8206c2f0>] ? nfnl_lock+0x20/0x20 > [<ffffffff82068159>] ? netlink_rcv_skb+0xa9/0xc0 > [<ffffffff820677bf>] ? netlink_unicast+0x12f/0x1c0 > [<ffffffff82067ade>] ? netlink_sendmsg+0x28e/0x650 > [<ffffffff81fdd814>] ? sock_sendmsg+0x44/0x50 > [<ffffffff81fde07b>] ? ___sys_sendmsg+0x2ab/0x2c0 > [<ffffffff810e8f73>] ? __wake_up+0x43/0x70 > [<ffffffff8141a134>] ? tty_write+0x1c4/0x2a0 > [<ffffffff81fde9f4>] ? __sys_sendmsg+0x44/0x80 > [<ffffffff823ff8d7>] ? system_call_fastpath+0x12/0x6a > Code: Bad RIP value. > RIP [<0000000100000001>] 0x100000001 > RSP <ffff8800ba9dba40> > CR2: 0000000100000001 > ---[ end trace 08eb65d42362793f ]--- Cc: stable@vger.kernel.org Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextPablo Neira Ayuso
Resolve conflicts between 5888b93 ("Merge branch 'nf-hook-compress'") and Florian Westphal br_netfilter works. Conflicts: net/bridge/br_netfilter.c Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-04-08netfilter: bridge: add helpers for fetching physin/outdevFlorian Westphal
right now we store this in the nf_bridge_info struct, accessible via skb->nf_bridge. This patch prepares removal of this pointer from skb: Instead of using skb->nf_bridge->x, we use helpers to obtain the in/out device (or ifindexes). Followup patches to netfilter will then allow nf_bridge_info to be obtained by a call into the br_netfilter core, rather than keeping a pointer to it in sk_buff. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2015-04-07netfilter: Pass socket pointer down through okfn().David Miller
On the output paths in particular, we have to sometimes deal with two socket contexts. First, and usually skb->sk, is the local socket that generated the frame. And second, is potentially the socket used to control a tunneling socket, such as one the encapsulates using UDP. We do not want to disassociate skb->sk when encapsulating in order to fix this, because that would break socket memory accounting. The most extreme case where this can cause huge problems is an AF_PACKET socket transmitting over a vxlan device. We hit code paths doing checks that assume they are dealing with an ipv4 socket, but are actually operating upon the AF_PACKET one. Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-07netfilter: Add socket pointer to nf_hook_state.David Miller
It is currently always set to NULL, but nf_queue is adjusted to be prepared for it being set to a real socket by taking and releasing a reference to that socket when necessary. Signed-off-by: David S. Miller <davem@davemloft.net>
2015-04-04netfilter: Use nf_hook_state in nf_queue_entry.David S. Miller
That way we don't have to reinstantiate another nf_hook_state on the stack of the nf_reinject() path. Signed-off-by: David S. Miller <davem@davemloft.net>