From: Gerrit Renker Date: Thu, 13 Dec 2007 13:28:43 +0000 (-0200) Subject: [DCCP]: Perform SHUT_RD and SHUT_WR on receiving close X-Git-Tag: v2.6.25-rc1~1162^2~1111 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=69567d0b63b7f4ffeb53fe746c87bd6efe1c284b;p=linux-2.6 [DCCP]: Perform SHUT_RD and SHUT_WR on receiving close This patch performs two changes: 1) Close the write-end in addition to the read-end when a fin-like segment (Close or CloseReq) is received by DCCP. This accounts for the fact that DCCP, in contrast to TCP, does not have a half-close. RFC 4340 says in this respect that when a fin-like segment has been sent there is no guarantee at all that any further data will be processed. Thus this patch performs SHUT_WR in addition to the SHUT_RD when a fin-like segment is encountered. 2) Minor change: I noted that code appears twice in different places and think it makes sense to put this into a self-contained function (dccp_enqueue()). Signed-off-by: Gerrit Renker Signed-off-by: Ian McDonald Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: David S. Miller --- diff --git a/net/dccp/input.c b/net/dccp/input.c index decf2f2114..dacd4fd3c6 100644 --- a/net/dccp/input.c +++ b/net/dccp/input.c @@ -22,16 +22,27 @@ /* rate-limit for syncs in reply to sequence-invalid packets; RFC 4340, 7.5.4 */ int sysctl_dccp_sync_ratelimit __read_mostly = HZ / 8; -static void dccp_fin(struct sock *sk, struct sk_buff *skb) +static void dccp_enqueue_skb(struct sock *sk, struct sk_buff *skb) { - sk->sk_shutdown |= RCV_SHUTDOWN; - sock_set_flag(sk, SOCK_DONE); __skb_pull(skb, dccp_hdr(skb)->dccph_doff * 4); __skb_queue_tail(&sk->sk_receive_queue, skb); skb_set_owner_r(skb, sk); sk->sk_data_ready(sk, 0); } +static void dccp_fin(struct sock *sk, struct sk_buff *skb) +{ + /* + * On receiving Close/CloseReq, both RD/WR shutdown are performed. + * RFC 4340, 8.3 says that we MAY send further Data/DataAcks after + * receiving the closing segment, but there is no guarantee that such + * data will be processed at all. + */ + sk->sk_shutdown = SHUTDOWN_MASK; + sock_set_flag(sk, SOCK_DONE); + dccp_enqueue_skb(sk, skb); +} + static int dccp_rcv_close(struct sock *sk, struct sk_buff *skb) { int queued = 0; @@ -282,10 +293,7 @@ static int __dccp_rcv_established(struct sock *sk, struct sk_buff *skb, * - sk_shutdown == RCV_SHUTDOWN, use Code 1, "Not Listening" * - sk_receive_queue is full, use Code 2, "Receive Buffer" */ - __skb_pull(skb, dh->dccph_doff * 4); - __skb_queue_tail(&sk->sk_receive_queue, skb); - skb_set_owner_r(skb, sk); - sk->sk_data_ready(sk, 0); + dccp_enqueue_skb(sk, skb); return 0; case DCCP_PKT_ACK: goto discard;