From efdfa2f7848f64517008136fb41f53c4a1faf93a Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Wed, 11 Nov 2015 23:25:40 +0100 Subject: packet: do skb_probe_transport_header when we actually have data In tpacket_fill_skb() commit c1aad275b029 ("packet: set transport header before doing xmit") and later on 40893fd0fd4e ("net: switch to use skb_probe_transport_header()") was probing for a transport header on the skb from a ring buffer slot, but at a time, where the skb has _not even_ been filled with data yet. So that call into the flow dissector is pretty useless. Lets do it after we've set up the skb frags. Fixes: c1aad275b029 ("packet: set transport header before doing xmit") Reported-by: Eric Dumazet Signed-off-by: Daniel Borkmann Acked-by: Jason Wang Signed-off-by: David S. Miller --- net/packet/af_packet.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'net/packet/af_packet.c') diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index af399cac5205..80c36c0867d3 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2368,8 +2368,6 @@ static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, skb_reserve(skb, hlen); skb_reset_network_header(skb); - if (!packet_use_direct_xmit(po)) - skb_probe_transport_header(skb, 0); if (unlikely(po->tp_tx_has_off)) { int off_min, off_max, off; off_min = po->tp_hdrlen - sizeof(struct sockaddr_ll); @@ -2449,6 +2447,9 @@ static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, len = ((to_write > len_max) ? len_max : to_write); } + if (!packet_use_direct_xmit(po)) + skb_probe_transport_header(skb, 0); + return tp_len; } -- cgit v1.2.3