From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shmulik Ladkani Subject: Re: [PATCH net] bridge: Fix incorrect re-injection of STP packets Date: Sat, 4 Jun 2016 09:41:41 +0300 Message-ID: <20160604094141.7dcc5687@halley> References: <1464946785-7651-1-git-send-email-idosch@mellanox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: , , , , , , , , , Florian Westphal To: Ido Schimmel Return-path: Received: from mail-wm0-f67.google.com ([74.125.82.67]:33987 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750748AbcFDGl4 (ORCPT ); Sat, 4 Jun 2016 02:41:56 -0400 Received: by mail-wm0-f67.google.com with SMTP id n184so3776496wmn.1 for ; Fri, 03 Jun 2016 23:41:55 -0700 (PDT) In-Reply-To: <1464946785-7651-1-git-send-email-idosch@mellanox.com> Sender: netdev-owner@vger.kernel.org List-ID: Hi, On Fri, 3 Jun 2016 12:39:45 +0300 Ido Schimmel wrote: > diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c > index 1607977..c73ed44 100644 > --- a/net/bridge/br_input.c > +++ b/net/bridge/br_input.c > @@ -223,9 +223,7 @@ static int br_handle_local_finish(struct net *net, struct sock *sk, struct sk_bu > if (p->flags & BR_LEARNING && br_should_learn(p, skb, &vid)) > br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vid, false); > > - BR_INPUT_SKB_CB(skb)->brdev = p->br->dev; > - br_pass_frame_up(skb); > - return 0; > + return RX_HANDLER_PASS; > } > > /* > @@ -238,6 +236,7 @@ rx_handler_result_t br_handle_frame(struct sk_buff **pskb) > struct sk_buff *skb = *pskb; > const unsigned char *dest = eth_hdr(skb)->h_dest; > br_should_route_hook_t *rhook; > + int err; > > if (unlikely(skb->pkt_type == PACKET_LOOPBACK)) > return RX_HANDLER_PASS; > @@ -287,8 +286,11 @@ rx_handler_result_t br_handle_frame(struct sk_buff **pskb) > } > > /* Deliver packet to local host only */ > - NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, dev_net(skb->dev), > - NULL, skb, skb->dev, NULL, br_handle_local_finish); > + err = NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN, dev_net(skb->dev), > + NULL, skb, skb->dev, NULL, > + br_handle_local_finish); > + if (err == RX_HANDLER_PASS) > + return RX_HANDLER_PASS; > return RX_HANDLER_CONSUMED; Seems '*pskb = skb' is needed prior returning RX_HANDLER_PASS - there's a 'skb = skb_share_check()' at beginning of br_handle_frame. (The *pskb = skb was present prior 8626c56c8279, but gone since there was no longer an RX_HANDLER_PASS return). One nit to consider: The fix relies on the fact that RX_HANDLER_PASS != 0 (otherwise we end up not knowing whether skb was STOLEN or br_handle_local_finish has executed, which was the original problem 8626c56c8279 tried to address). No reason to use the RX_HANDLER_xxx enumeration space as the ret code of an 'okfn' (br_handle_local_finish in this case). Some positive value locally defined in br_input.c (and documented in br_handle_local_finish) would do. Regards, Shmulik