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-rw-r--r--Documentation/networking/dccp.txt2
-rw-r--r--net/dccp/input.c27
-rw-r--r--net/dccp/proto.c2
3 files changed, 23 insertions, 8 deletions
diff --git a/Documentation/networking/dccp.txt b/Documentation/networking/dccp.txt
index afb66f9a8aff..f771034e8f27 100644
--- a/Documentation/networking/dccp.txt
+++ b/Documentation/networking/dccp.txt
@@ -72,6 +72,8 @@ DCCP_SOCKOPT_CCID_TX_INFO
Returns a `struct tfrc_tx_info' in optval; the buffer for optval and
optlen must be set to at least sizeof(struct tfrc_tx_info).
+On unidirectional connections it is useful to close the unused half-connection
+via shutdown (SHUT_WR or SHUT_RD): this will reduce per-packet processing costs.
Sysctl variables
================
diff --git a/net/dccp/input.c b/net/dccp/input.c
index 1ce101062824..df0fb2c149a6 100644
--- a/net/dccp/input.c
+++ b/net/dccp/input.c
@@ -103,6 +103,21 @@ static void dccp_event_ack_recv(struct sock *sk, struct sk_buff *skb)
DCCP_SKB_CB(skb)->dccpd_ack_seq);
}
+static void dccp_deliver_input_to_ccids(struct sock *sk, struct sk_buff *skb)
+{
+ const struct dccp_sock *dp = dccp_sk(sk);
+
+ /* Don't deliver to RX CCID when node has shut down read end. */
+ if (!(sk->sk_shutdown & RCV_SHUTDOWN))
+ ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb);
+ /*
+ * Until the TX queue has been drained, we can not honour SHUT_WR, since
+ * we need received feedback as input to adjust congestion control.
+ */
+ if (sk->sk_write_queue.qlen > 0 || !(sk->sk_shutdown & SEND_SHUTDOWN))
+ ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb);
+}
+
static int dccp_check_seqno(struct sock *sk, struct sk_buff *skb)
{
const struct dccp_hdr *dh = dccp_hdr(skb);
@@ -209,8 +224,9 @@ static int __dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
case DCCP_PKT_DATAACK:
case DCCP_PKT_DATA:
/*
- * FIXME: check if sk_receive_queue is full, schedule DATA_DROPPED
- * option if it is.
+ * FIXME: schedule DATA_DROPPED (RFC 4340, 11.7.2) if and when
+ * - 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);
@@ -300,9 +316,7 @@ int dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
DCCP_SKB_CB(skb)->dccpd_seq,
DCCP_ACKVEC_STATE_RECEIVED))
goto discard;
-
- ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb);
- ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb);
+ dccp_deliver_input_to_ccids(sk, skb);
return __dccp_rcv_established(sk, skb, dh, len);
discard:
@@ -543,8 +557,7 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
DCCP_ACKVEC_STATE_RECEIVED))
goto discard;
- ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb);
- ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb);
+ dccp_deliver_input_to_ccids(sk, skb);
}
/*
diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index 7a3bea9c28c1..0aec73592124 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -981,7 +981,7 @@ EXPORT_SYMBOL_GPL(dccp_close);
void dccp_shutdown(struct sock *sk, int how)
{
- dccp_pr_debug("entry\n");
+ dccp_pr_debug("called shutdown(%x)\n", how);
}
EXPORT_SYMBOL_GPL(dccp_shutdown);