From mboxrd@z Thu Jan 1 00:00:00 1970 From: Edward Jee Subject: [PATCH] inet: frags: fix defragmented packet's IP header for af_packet Date: Thu, 16 Jul 2015 01:54:41 -0700 Message-ID: <1437036881-708-1-git-send-email-edjee@google.com> Cc: willemb@google.com, edumazet@google.com, hkchu@google.com, netdev@vger.kernel.org, Edward Jee To: davem@davemloft.net Return-path: Received: from mail-ig0-f180.google.com ([209.85.213.180]:37573 "EHLO mail-ig0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754589AbbGPIzL (ORCPT ); Thu, 16 Jul 2015 04:55:11 -0400 Received: by igbpg9 with SMTP id pg9so8610957igb.0 for ; Thu, 16 Jul 2015 01:55:10 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: When ip_frag_queue() computes positions, it assumes that the passed sk_buff does not contain L2 headers. However, when PACKET_FANOUT_FLAG_DEFRAG is used, IP defragmentation functions can be called on outgoing packets that contain L2 headers. Also, IPv4 checksum is not corrected after defragmentation. Fixes: 7736d33f4262 ("packet: Add pre-defragmentation support for ipv4 fanouts.") Signed-off-by: Edward Hyunkoo Jee Acked-by: Eric Dumazet Cc: Willem de Bruijn Cc: Jerry Chu --- net/ipv4/ip_fragment.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c index a50dc6d..44c8f2a 100644 --- a/net/ipv4/ip_fragment.c +++ b/net/ipv4/ip_fragment.c @@ -351,7 +351,7 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb) ihl = ip_hdrlen(skb); /* Determine the position of this fragment. */ - end = offset + skb->len - ihl; + end = offset + skb->len - skb_network_offset(skb) - ihl; err = -EINVAL; /* Is this the final fragment? */ @@ -381,7 +381,7 @@ static int ip_frag_queue(struct ipq *qp, struct sk_buff *skb) goto err; err = -ENOMEM; - if (!pskb_pull(skb, ihl)) + if (!pskb_pull(skb, skb_network_offset(skb) + ihl)) goto err; err = pskb_trim_rcsum(skb, end - offset); @@ -641,6 +641,8 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev, iph->frag_off = 0; } + ip_send_check(ip_hdr(skb)); + IP_INC_STATS_BH(net, IPSTATS_MIB_REASMOKS); qp->q.fragments = NULL; qp->q.fragments_tail = NULL; -- 2.4.3.573.g4eafbef