From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: [PATCH net-next 1/3] tcp: gro: add checksuming helpers Date: Thu, 27 Sep 2012 14:14:53 +0200 Message-ID: <1348748093.5093.1171.camel@edumazet-glaptop> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netdev To: David Miller Return-path: Received: from mail-bk0-f46.google.com ([209.85.214.46]:59061 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752418Ab2I0MO5 (ORCPT ); Thu, 27 Sep 2012 08:14:57 -0400 Received: by bkcjk13 with SMTP id jk13so1651458bkc.19 for ; Thu, 27 Sep 2012 05:14:56 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: From: Eric Dumazet skb with CHECKSUM_NONE cant currently be handled by GRO, and we notice this deep in GRO stack in tcp[46]_gro_receive() But there are cases where GRO can be a benefit, even with a lack of checksums. This preliminary work is needed to add GRO support to tunnels. Signed-off-by: Eric Dumazet --- net/ipv4/tcp_ipv4.c | 19 ++++++++++++++++--- net/ipv6/tcp_ipv6.c | 20 +++++++++++++++++--- 2 files changed, 33 insertions(+), 6 deletions(-) diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 93406c5..27a235c 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -2804,6 +2804,8 @@ void tcp4_proc_exit(void) struct sk_buff **tcp4_gro_receive(struct sk_buff **head, struct sk_buff *skb) { const struct iphdr *iph = skb_gro_network_header(skb); + __wsum wsum; + __sum16 sum; switch (skb->ip_summed) { case CHECKSUM_COMPLETE: @@ -2812,11 +2814,22 @@ struct sk_buff **tcp4_gro_receive(struct sk_buff **head, struct sk_buff *skb) skb->ip_summed = CHECKSUM_UNNECESSARY; break; } - - /* fall through */ - case CHECKSUM_NONE: +flush: NAPI_GRO_CB(skb)->flush = 1; return NULL; + + case CHECKSUM_NONE: + wsum = csum_tcpudp_nofold(iph->saddr, iph->daddr, + skb_gro_len(skb), IPPROTO_TCP, 0); + sum = csum_fold(skb_checksum(skb, + skb_gro_offset(skb), + skb_gro_len(skb), + wsum)); + if (sum) + goto flush; + + skb->ip_summed = CHECKSUM_UNNECESSARY; + break; } return tcp_gro_receive(head, skb); diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index d6212d6..49c8903 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -763,6 +763,8 @@ static struct sk_buff **tcp6_gro_receive(struct sk_buff **head, struct sk_buff *skb) { const struct ipv6hdr *iph = skb_gro_network_header(skb); + __wsum wsum; + __sum16 sum; switch (skb->ip_summed) { case CHECKSUM_COMPLETE: @@ -771,11 +773,23 @@ static struct sk_buff **tcp6_gro_receive(struct sk_buff **head, skb->ip_summed = CHECKSUM_UNNECESSARY; break; } - - /* fall through */ - case CHECKSUM_NONE: +flush: NAPI_GRO_CB(skb)->flush = 1; return NULL; + + case CHECKSUM_NONE: + wsum = ~csum_unfold(csum_ipv6_magic(&iph->saddr, &iph->daddr, + skb_gro_len(skb), + IPPROTO_TCP, 0)); + sum = csum_fold(skb_checksum(skb, + skb_gro_offset(skb), + skb_gro_len(skb), + wsum)); + if (sum) + goto flush; + + skb->ip_summed = CHECKSUM_UNNECESSARY; + break; } return tcp_gro_receive(head, skb);