From: Gerrit Renker <gerrit@xxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxx>
Signed-off-by: Ian McDonald <ian.mcdonald@xxxxxxxxxxx>
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
net/dccp/input.c | 22 +++++++++++++++-------
1 files changed, 15 insertions(+), 7 deletions(-)
diff --git a/net/dccp/input.c b/net/dccp/input.c
index decf2f2..dacd4fd 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;
--
1.5.3.4
-
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