inet: frags: fix defragmented packet's IP header for af_packet
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 reassembly
functions can be called on outgoing packets that contain L2 headers.
Also, IPv4 checksum is not corrected after reassembly.
Fixes: 7736d33f4262 ("packet: Add pre-defragmentation support for ipv4 fanouts.")
Signed-off-by: Edward Hyunkoo Jee <edjee@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Jerry Chu <hkchu@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index a50dc6d4..31f71b1 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -351,7 +351,7 @@
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 @@
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 @@
iph->frag_off = 0;
}
+ ip_send_check(iph);
+
IP_INC_STATS_BH(net, IPSTATS_MIB_REASMOKS);
qp->q.fragments = NULL;
qp->q.fragments_tail = NULL;