From 1b048ea7242555f91066228ef136ba299f4ae567 Mon Sep 17 00:00:00 2001 From: Eric Leblond Date: Thu, 16 Aug 2012 22:02:58 +0000 Subject: af_packet: don't emit packet on orig fanout group [ Upstream commit c0de08d04215031d68fa13af36f347a6cfa252ca ] If a packet is emitted on one socket in one group of fanout sockets, it is transmitted again. It is thus read again on one of the sockets of the fanout group. This result in a loop for software which generate packets when receiving one. This retransmission is not the intended behavior: a fanout group must behave like a single socket. The packet should not be transmitted on a socket if it originates from a socket belonging to the same fanout group. This patch fixes the issue by changing the transmission check to take fanout group info account. Reported-by: Aleksandr Kotov Signed-off-by: Eric Leblond Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- net/packet/af_packet.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'net/packet') diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 13b14dc..85afc13 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -1281,6 +1281,14 @@ static void __fanout_unlink(struct sock *sk, struct packet_sock *po) spin_unlock(&f->lock); } +bool match_fanout_group(struct packet_type *ptype, struct sock * sk) +{ + if (ptype->af_packet_priv == (void*)((struct packet_sock *)sk)->fanout) + return true; + + return false; +} + static int fanout_add(struct sock *sk, u16 id, u16 type_flags) { struct packet_sock *po = pkt_sk(sk); @@ -1333,6 +1341,7 @@ static int fanout_add(struct sock *sk, u16 id, u16 type_flags) match->prot_hook.dev = po->prot_hook.dev; match->prot_hook.func = packet_rcv_fanout; match->prot_hook.af_packet_priv = match; + match->prot_hook.id_match = match_fanout_group; dev_add_pack(&match->prot_hook); list_add(&match->list, &fanout_list); } -- cgit v1.1