net: Introduce sk_route_nocaps
TCP-MD5 sessions have intermittent failures, when route cache is
invalidated. ip_queue_xmit() has to find a new route, calls
sk_setup_caps(sk, &rt->u.dst), destroying the
sk->sk_route_caps &= ~NETIF_F_GSO_MASK
that MD5 desperately try to make all over its way (from
tcp_transmit_skb() for example)
So we send few bad packets, and everything is fine when
tcp_transmit_skb() is called again for this socket.
Since ip_queue_xmit() is at a lower level than TCP-MD5, I chose to use a
socket field, sk_route_nocaps, containing bits to mask on sk_route_caps.
Reported-by: Bhaskar Dutta <bhaskie@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 771f814..202cf09 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -891,7 +891,7 @@
kfree(newkey);
return -ENOMEM;
}
- sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
+ sk_nocaps_add(sk, NETIF_F_GSO_MASK);
}
if (tcp_alloc_md5sig_pool(sk) == NULL) {
kfree(newkey);
@@ -1021,7 +1021,7 @@
return -EINVAL;
tp->md5sig_info = p;
- sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
+ sk_nocaps_add(sk, NETIF_F_GSO_MASK);
}
newkey = kmemdup(cmd.tcpm_key, cmd.tcpm_keylen, sk->sk_allocation);
@@ -1462,7 +1462,7 @@
if (newkey != NULL)
tcp_v4_md5_do_add(newsk, newinet->inet_daddr,
newkey, key->keylen);
- newsk->sk_route_caps &= ~NETIF_F_GSO_MASK;
+ sk_nocaps_add(newsk, NETIF_F_GSO_MASK);
}
#endif