On Sun, 2012-05-27 at 20:13 +0100, Jack Stone wrote:
On 05/27/2012 06:35 PM, Eric Dumazet wrote:
quoted
So it seems we can queue in sk_receive_queue a packet with SYN flag set.
(A SYN or SYNACK packet contains DATA payload...)
The sequence number of such frames should be tweaked (seq++) instead of
games we do in fast path :
if (tcp_hdr(skb)->syn)
offset--;
Oh well this can wait linux-3.6, please test following patch in the
meantime.
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index b224eb8..34c8dcc 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -4553,7 +4553,7 @@ static bool tcp_try_coalesce(struct sock *sk,
*fragstolen = false;
- if (tcp_hdr(from)->fin)
+ if (tcp_hdr(from)->fin || tcp_hdr(to)->syn)
return false;
/* Its possible this segment overlaps with prior segment in queue */
Still seems to fire with the above applied, it also sets of the warn just above it...
Could it be something to do with my staging network driver?
Yes it could be memory corruption.
(making tcp _think_ tcp_hdr(skb)->syn is set, while it was not at all.
Please replace debugging patch by following, because tcp flags are
copied elsewhere, so we can double check.
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 3ba605f..22e4c9a 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1606,8 +1606,10 @@ int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
if (tcp_hdr(skb)->fin)
goto found_fin_ok;
WARN(!(flags & MSG_PEEK),
- "recvmsg bug 2: copied %X seq %X rcvnxt %X fl %X\n",
- *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, flags);
+ "recvmsg bug 2: copied %X seq %X end_seq %X rcvnxt %X fl %X offset %u len %u syn %d tcp_flags %X\n",
+ *seq, TCP_SKB_CB(skb)->seq, TCP_SKB_CB(skb)->end_seq,
+ tp->rcv_nxt, flags, offset, skb->len, tcp_hdr(skb)->syn,
+ TCP_SKB_CB(skb)->tcp_flags);
}
/* Well, if we have backlog, try to process it now yet. */