[DCCP]: Perform SHUT_RD and SHUT_WR on receiving close (69567d0b) · Commits · 戴 / test

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 <gerrit@erg.abdn.ac.uk> Signed-off-by:

Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by:

Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/dccp/input.c

+15 −7

Original line number	Diff line number	Diff line
		@@ -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;

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