[DCCP]: Honour and make use of shutdown option set by user

[mirror_ubuntu-bionic-kernel.git] / net / dccp / input.c

diff --git a/net/dccp/input.c b/net/dccp/input.c
index 1ce101062824ef25fca9280889a572ae2c62408b..df0fb2c149a6a994685c136cd7b57fc568fe0e87 100644 (file)
--- 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);
        }
 
        /*