From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: [PATCH net-next 1/2] tcp: introduce TCP_SKB_CB(skb)->tcp_tw_isn Date: Fri, 5 Sep 2014 15:33:32 -0700 Message-ID: <1409956413-29472-2-git-send-email-edumazet@google.com> References: <1409956413-29472-1-git-send-email-edumazet@google.com> Cc: netdev@vger.kernel.org, Yuchung Cheng , Neal Cardwell , Eric Dumazet To: "David S. Miller" Return-path: Received: from mail-oa0-f74.google.com ([209.85.219.74]:49746 "EHLO mail-oa0-f74.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751144AbaIEWdh (ORCPT ); Fri, 5 Sep 2014 18:33:37 -0400 Received: by mail-oa0-f74.google.com with SMTP id eb12so2150794oac.5 for ; Fri, 05 Sep 2014 15:33:36 -0700 (PDT) In-Reply-To: <1409956413-29472-1-git-send-email-edumazet@google.com> Sender: netdev-owner@vger.kernel.org List-ID: TCP_SKB_CB(skb)->when has different meaning in output and input paths. In output path, it contains a timestamp. In input path, it contains an ISN, chosen by tcp_timewait_state_process() Lets add a different name to ease code comprehension. Note that 'when' field will disappear in following patch, as skb_mstamp already contains timestamp, the anonymous union will promptly disappear as well. Signed-off-by: Eric Dumazet --- include/net/tcp.h | 7 ++++++- net/ipv4/tcp_input.c | 2 +- net/ipv4/tcp_ipv4.c | 2 +- net/ipv4/tcp_minisocks.c | 2 +- net/ipv6/tcp_ipv6.c | 4 ++-- 5 files changed, 11 insertions(+), 6 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index 590e01a476ac..0cd7d2c65dc0 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -698,7 +698,12 @@ struct tcp_skb_cb { } header; /* For incoming frames */ __u32 seq; /* Starting sequence number */ __u32 end_seq; /* SEQ + FIN + SYN + datalen */ - __u32 when; /* used to compute rtt's */ + union { + /* used in output path */ + __u32 when; /* used to compute rtt's */ + /* used in input path */ + __u32 tcp_tw_isn; /* isn chosen by tcp_timewait_state_process() */ + }; __u8 tcp_flags; /* TCP header flags. (tcp[13]) */ __u8 sacked; /* State flags for SACK/FACK. */ diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index aba4926ca095..9c8b9f1dcf69 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5906,7 +5906,7 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops, struct request_sock *req; struct tcp_sock *tp = tcp_sk(sk); struct dst_entry *dst = NULL; - __u32 isn = TCP_SKB_CB(skb)->when; + __u32 isn = TCP_SKB_CB(skb)->tcp_tw_isn; bool want_cookie = false, fastopen; struct flowi fl; struct tcp_fastopen_cookie foc = { .len = -1 }; diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 487e2a41667f..02e6cd29ebf1 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1627,7 +1627,7 @@ int tcp_v4_rcv(struct sk_buff *skb) TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin + skb->len - th->doff * 4); TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq); - TCP_SKB_CB(skb)->when = 0; + TCP_SKB_CB(skb)->tcp_tw_isn = 0; TCP_SKB_CB(skb)->ip_dsfield = ipv4_get_dsfield(iph); TCP_SKB_CB(skb)->sacked = 0; diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index 1649988bd1b6..a058f411d3a6 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -232,7 +232,7 @@ kill: u32 isn = tcptw->tw_snd_nxt + 65535 + 2; if (isn == 0) isn++; - TCP_SKB_CB(skb)->when = isn; + TCP_SKB_CB(skb)->tcp_tw_isn = isn; return TCP_TW_SYN; } diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 29964c3d363c..5b3c70ff7a72 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -738,7 +738,7 @@ static void tcp_v6_init_req(struct request_sock *req, struct sock *sk, ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL) ireq->ir_iif = inet6_iif(skb); - if (!TCP_SKB_CB(skb)->when && + if (!TCP_SKB_CB(skb)->tcp_tw_isn && (ipv6_opt_accepted(sk, skb) || np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo || np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim || np->repflow)) { @@ -1412,7 +1412,7 @@ static int tcp_v6_rcv(struct sk_buff *skb) TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin + skb->len - th->doff*4); TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq); - TCP_SKB_CB(skb)->when = 0; + TCP_SKB_CB(skb)->tcp_tw_isn = 0; TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr); TCP_SKB_CB(skb)->sacked = 0; -- 2.1.0.rc2.206.gedb03e5