From bf296b125b21b8d558ceb6ec30bb4eba2730cd6b Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Mon, 15 Dec 2008 23:43:36 -0800 Subject: tcp: Add GRO support This patch adds the TCP-specific portion of GRO. The criterion for merging is extremely strict (the TCP header must match exactly apart from the checksum) so as to allow refragmentation. Otherwise this is pretty much identical to LRO, except that we support the merging of ECN packets. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- net/ipv4/tcp_ipv4.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) (limited to 'net/ipv4/tcp_ipv4.c') diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 26b9030747c..10172487921 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -2346,6 +2346,41 @@ void tcp4_proc_exit(void) } #endif /* CONFIG_PROC_FS */ +struct sk_buff **tcp4_gro_receive(struct sk_buff **head, struct sk_buff *skb) +{ + struct iphdr *iph = ip_hdr(skb); + + switch (skb->ip_summed) { + case CHECKSUM_COMPLETE: + if (!tcp_v4_check(skb->len, iph->saddr, iph->daddr, + skb->csum)) { + skb->ip_summed = CHECKSUM_UNNECESSARY; + break; + } + + /* fall through */ + case CHECKSUM_NONE: + NAPI_GRO_CB(skb)->flush = 1; + return NULL; + } + + return tcp_gro_receive(head, skb); +} +EXPORT_SYMBOL(tcp4_gro_receive); + +int tcp4_gro_complete(struct sk_buff *skb) +{ + struct iphdr *iph = ip_hdr(skb); + struct tcphdr *th = tcp_hdr(skb); + + th->check = ~tcp_v4_check(skb->len - skb_transport_offset(skb), + iph->saddr, iph->daddr, 0); + skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; + + return tcp_gro_complete(skb); +} +EXPORT_SYMBOL(tcp4_gro_complete); + struct proto tcp_prot = { .name = "TCP", .owner = THIS_MODULE, -- cgit v1.2.3