From b0da8537037f337103348f239ad901477e907aa8 Mon Sep 17 00:00:00 2001 From: Michael Chan Date: Thu, 29 Jun 2006 12:30:00 -0700 Subject: [NET]: Add ECN support for TSO In the current TSO implementation, NETIF_F_TSO and ECN cannot be turned on together in a TCP connection. The problem is that most hardware that supports TSO does not handle CWR correctly if it is set in the TSO packet. Correct handling requires CWR to be set in the first packet only if it is set in the TSO header. This patch adds the ability to turn on NETIF_F_TSO and ECN using GSO if necessary to handle TSO packets with CWR set. Hardware that handles CWR correctly can turn on NETIF_F_TSO_ECN in the dev-> features flag. All TSO packets with CWR set will have the SKB_GSO_TCPV4_ECN set. If the output device does not have the NETIF_F_TSO_ECN feature set, GSO will split the packet up correctly with CWR only set in the first segment. With help from Herbert Xu . Since ECN can always be enabled with TSO, the SOCK_NO_LARGESEND sock flag is completely removed. Signed-off-by: Michael Chan Signed-off-by: David S. Miller --- net/ipv4/tcp_output.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'net/ipv4/tcp_output.c') diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index bdd71db8bf90..5a7cb4a9c867 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2044,8 +2044,6 @@ struct sk_buff * tcp_make_synack(struct sock *sk, struct dst_entry *dst, memset(th, 0, sizeof(struct tcphdr)); th->syn = 1; th->ack = 1; - if (dst->dev->features&NETIF_F_TSO) - ireq->ecn_ok = 0; TCP_ECN_make_synack(req, th); th->source = inet_sk(sk)->sport; th->dest = ireq->rmt_port; -- cgit v1.2.2