linux/net/netfilter/nf_queue.c, branch v4.11

netfilter: introduce accessor functions for hook entries

2016-12-06T20:42:15Z

This allows easier future refactoring. Signed-off-by: Aaron Conole Signed-off-by: Pablo Neira Ayuso

netfilter: merge nf_iterate() into nf_hook_slow()

2016-11-03T10:52:59Z

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

netfilter: remove hook_entries field from nf_hook_state

2016-11-03T10:52:58Z

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

netfilter: kill NF_HOOK_THRESH() and state->tresh

2016-11-03T09:56:12Z

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 Signed-off-by: Pablo Neira Ayuso

netfilter: fix nf_queue handling

2016-10-20T17:59:59Z

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

netfilter: replace list_head with single linked list

2016-09-25T12:38:48Z

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 Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

netfilter: nf_queue: Make the queue_handler pernet

2016-05-25T09:54:22Z

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: [] nfqnl_nf_hook_drop+0x35/0x70 > [..] > task: ffff88012dfa3840 ti: ffff88012dffc000 task.ti: ffff88012dffc000 > RIP: 0010:[] [] nfqnl_nf_hook_drop+0x35/0x70 > RSP: 0000:ffff88012dfffd80 EFLAGS: 00010206 > RAX: 0000000000000008 RBX: ffffffff81add0c0 RCX: ffff88013fd80000 > [..] > Call Trace: > [] nf_queue_nf_hook_drop+0x18/0x20 > [] nf_unregister_net_hook+0xdb/0x150 > [] netfilter_net_exit+0x2f/0x60 > [] ops_exit_list.isra.4+0x38/0x60 > [] setup_net+0xc2/0x120 > [] copy_net_ns+0x79/0x120 > [] create_new_namespaces+0x11b/0x1e0 > [] unshare_nsproxy_namespaces+0x57/0xa0 > [] SyS_unshare+0x1b2/0x340 > [] 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 Signed-off-by: "Eric W. Biederman" Acked-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

netfilter: nf_queue: remove rcu_read_lock calls

2015-10-16T16:22:41Z

All verdict handlers make use of the nfnetlink .call_rcu callback so rcu readlock is already held. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso

netfilter: make nf_queue_entry_get_refs return void

2015-10-16T16:22:23Z

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 Signed-off-by: Pablo Neira Ayuso

netfilter: remove hook owner refcounting

2015-10-16T16:21:39Z

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 Signed-off-by: Pablo Neira Ayuso