kernel.git/net/bridge/br_input.c, branch linux-4.8.y

net: bridge: don't increment tx_dropped in br_do_proxy_arp

2016-09-01T23:35:30Z

pskb_may_pull may fail due to various reasons (e.g. alloc failure), but the skb isn't changed/dropped and processing continues so we shouldn't increment tx_dropped. CC: Kyeyoon Park CC: Roopa Prabhu CC: Stephen Hemminger CC: bridge@lists.linux-foundation.org Fixes: 958501163ddd ("bridge: Add support for IEEE 802.11 Proxy ARP") Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller

bridge: Fix incorrect re-injection of LLDP packets

2016-07-25T17:53:34Z

Commit 8626c56c8279 ("bridge: fix potential use-after-free when hook returns QUEUE or STOLEN verdict") caused LLDP packets arriving through a bridge port to be re-injected to the Rx path with skb->dev set to the bridge device, but this breaks the lldpad daemon. The lldpad daemon opens a packet socket with protocol set to ETH_P_LLDP for any valid device on the system, which doesn't not include soft devices such as bridge and VLAN. Since packet sockets (ptype_base) are processed in the Rx path after the Rx handler, LLDP packets with skb->dev set to the bridge device never reach the lldpad daemon. Fix this by making the bridge's Rx handler re-inject LLDP packets with RX_HANDLER_PASS, which effectively restores the behaviour prior to the mentioned commit. This means netfilter will never receive LLDP packets coming through a bridge port, as I don't see a way in which we can have okfn() consume the packet without breaking existing behaviour. I've already carried out a similar fix for STP packets in commit 56fae404fb2c ("bridge: Fix incorrect re-injection of STP packets"). Fixes: 8626c56c8279 ("bridge: fix potential use-after-free when hook returns QUEUE or STOLEN verdict") Signed-off-by: Ido Schimmel Reviewed-by: Jiri Pirko Cc: Florian Westphal Cc: John Fastabend Signed-off-by: David S. Miller

net: bridge: remove _deliver functions and consolidate forward code

2016-07-17T02:57:38Z

Before this patch we had two flavors of most forwarding functions - _forward and _deliver, the difference being that the latter are used when the packets are locally originated. Instead of all this function pointer passing and code duplication, we can just pass a boolean noting that the packet was locally originated and use that to perform the necessary checks in __br_forward. This gives a minor performance improvement but more importantly consolidates the forwarding paths. Also add a kernel doc comment to explain the exported br_forward()'s arguments. Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller

net: bridge: drop skb2/skb0 variables and use a local_rcv boolean

2016-07-17T02:57:38Z

Currently if the packet is going to be received locally we set skb0 or sometimes called skb2 variables to the original skb. This can get confusing and also we can avoid one conditional on the fast path by simply using a boolean and passing it around. Thanks to Roopa for the name suggestion. Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller

net: bridge: rearrange flood vs unicast receive paths

2016-07-17T02:57:37Z

This patch removes one conditional from the unicast path by using the fact that skb is NULL only when the packet is multicast or is local. Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller

net: bridge: minor style adjustments in br_handle_frame_finish

2016-07-17T02:57:37Z

Trivial style changes in br_handle_frame_finish. Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller

net: bridge: extend MLD/IGMP query stats

2016-07-09T21:40:09Z

As was suggested this patch adds support for the different versions of MLD and IGMP query types. Since the user visible structure is still in net-next we can augment it instead of adding netlink attributes. The distinction between the different IGMP/MLD query types is done as suggested in Section 7.1, RFC 3376 [1] and Section 8.1, RFC 3810 [2] based on query payload size and code for IGMP. Since all IGMP packets go through multicast_rcv() and it uses ip_mc_check_igmp/ipv6_mc_check_mld we can be sure that at least the ip/ipv6 header can be directly used. [1] https://tools.ietf.org/html/rfc3376#section-7 [2] https://tools.ietf.org/html/rfc3810#section-8.1 Suggested-by: Linus Lüssing Signed-off-by: Nikolay Aleksandrov Acked-by: Stephen Hemminger Signed-off-by: David S. Miller

net: bridge: add support for IGMP/MLD stats and export them via netlink

2016-06-30T10:18:24Z

This patch adds stats support for the currently used IGMP/MLD types by the bridge. The stats are per-port (plus one stat per-bridge) and per-direction (RX/TX). The stats are exported via netlink via the new linkxstats API (RTM_GETSTATS). In order to minimize the performance impact, a new option is used to enable/disable the stats - multicast_stats_enabled, similar to the recent vlan stats. Also in order to avoid multiple IGMP/MLD type lookups and checks, we make use of the current "igmp" member of the bridge private skb->cb region to record the type on Rx (both host-generated and external packets pass by multicast_rcv()). We can do that since the igmp member was used as a boolean and all the valid IGMP/MLD types are positive values. The normal bridge fast-path is not affected at all, the only affected paths are the flooding ones and since we make use of the IGMP/MLD type, we can quickly determine if the packet should be counted using cache-hot data (cb's igmp member). We add counters for: * IGMP Queries * IGMP Leaves * IGMP v1/v2/v3 reports * MLD Queries * MLD Leaves * MLD v1/v2 reports These are invaluable when monitoring or debugging complex multicast setups with bridges. Signed-off-by: Nikolay Aleksandrov Signed-off-by: David S. Miller

bridge: Fix incorrect re-injection of STP packets

2016-06-11T05:41:58Z

Commit 8626c56c8279 ("bridge: fix potential use-after-free when hook returns QUEUE or STOLEN verdict") fixed incorrect usage of NF_HOOK's return value by consuming packets in okfn via br_pass_frame_up(). However, this function re-injects packets to the Rx path with skb->dev set to the bridge device, which breaks kernel's STP, as all STP packets appear to originate from the bridge device itself. Instead, if STP is enabled and bridge isn't a 802.1ad bridge, then learn packet's SMAC and inject it back to the Rx path for further processing by the packet handlers. The patch also makes netfilter's behavior consistent with regards to packets destined to the Bridge Group Address, as no hook registered at LOCAL_IN will ever be called, regardless if STP is enabled or not. Cc: Florian Westphal Cc: Shmulik Ladkani Cc: Toshiaki Makita Fixes: 8626c56c8279 ("bridge: fix potential use-after-free when hook returns QUEUE or STOLEN verdict") Signed-off-by: Jiri Pirko Signed-off-by: Ido Schimmel Signed-off-by: David S. Miller

bridge: fix potential use-after-free when hook returns QUEUE or STOLEN verdict

2016-03-14T19:46:41Z

Zefir Kurtisi reported kernel panic with an openwrt specific patch. However, it turns out that mainline has a similar bug waiting to happen. Once NF_HOOK() returns the skb is in undefined state and must not be used. Moreover, the okfn must consume the skb to support async processing (NF_QUEUE). Current okfn in this spot doesn't consume it and caller assumes that NF_HOOK return value tells us if skb was freed or not, but thats wrong. It "works" because no in-tree user registers a NFPROTO_BRIDGE hook at LOCAL_IN that returns STOLEN or NF_QUEUE verdicts. Once we add NF_QUEUE support for nftables bridge this will break -- NF_QUEUE holds the skb for async processing, caller will erronoulsy return RX_HANDLER_PASS and on reinject netfilter will access free'd skb. Fix this by pushing skb up the stack in the okfn instead. NB: It also seems dubious to use LOCAL_IN while bypassing PRE_ROUTING completely in this case but this is how its been forever so it seems preferable to not change this. Cc: Felix Fietkau Cc: Zefir Kurtisi Signed-off-by: Florian Westphal Tested-by: Zefir Kurtisi Signed-off-by: David S. Miller