From 28b2774a0d5852236dab77a4147b8b88548110f1 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 8 Mar 2010 11:32:01 -0800 Subject: [PATCH] tcp: Fix tcp_make_synack() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Commit 4957faad (TCPCT part 1g: Responder Cookie => Initiator), part of TCP_COOKIE_TRANSACTION implementation, forgot to correctly size synack skb in case user data must be included. Many thanks to Mika Pentillä for spotting this error. Reported-by: Penttillä Mika Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/tcp_output.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 4a1605d..f181b78 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2395,13 +2395,17 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst, struct tcp_extend_values *xvp = tcp_xv(rvp); struct inet_request_sock *ireq = inet_rsk(req); struct tcp_sock *tp = tcp_sk(sk); + const struct tcp_cookie_values *cvp = tp->cookie_values; struct tcphdr *th; struct sk_buff *skb; struct tcp_md5sig_key *md5; int tcp_header_size; int mss; + int s_data_desired = 0; - skb = sock_wmalloc(sk, MAX_TCP_HEADER + 15, 1, GFP_ATOMIC); + if (cvp != NULL && cvp->s_data_constant && cvp->s_data_desired) + s_data_desired = cvp->s_data_desired; + skb = sock_wmalloc(sk, MAX_TCP_HEADER + 15 + s_data_desired, 1, GFP_ATOMIC); if (skb == NULL) return NULL; @@ -2457,16 +2461,12 @@ struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst, TCPCB_FLAG_SYN | TCPCB_FLAG_ACK); if (OPTION_COOKIE_EXTENSION & opts.options) { - const struct tcp_cookie_values *cvp = tp->cookie_values; - - if (cvp != NULL && - cvp->s_data_constant && - cvp->s_data_desired > 0) { - u8 *buf = skb_put(skb, cvp->s_data_desired); + if (s_data_desired) { + u8 *buf = skb_put(skb, s_data_desired); /* copy data directly from the listening socket. */ - memcpy(buf, cvp->s_data_payload, cvp->s_data_desired); - TCP_SKB_CB(skb)->end_seq += cvp->s_data_desired; + memcpy(buf, cvp->s_data_payload, s_data_desired); + TCP_SKB_CB(skb)->end_seq += s_data_desired; } if (opts.hash_size > 0) { -- 2.7.4