[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 3560a2a875a05561f2d0b353cb62b6b58095e8b4..df0fb2c149a6a994685c136cd7b57fc568fe0e87 100644 (file)
--- a/net/dccp/input.c
+++ b/net/dccp/input.c
@@ -58,6 +58,42 @@ static void dccp_rcv_closereq(struct sock *sk, struct sk_buff *skb)
        dccp_send_close(sk, 0);
 }
 
+static u8 dccp_reset_code_convert(const u8 code)
+{
+       const u8 error_code[] = {
+       [DCCP_RESET_CODE_CLOSED]             = 0,       /* normal termination */
+       [DCCP_RESET_CODE_UNSPECIFIED]        = 0,       /* nothing known */
+       [DCCP_RESET_CODE_ABORTED]            = ECONNRESET,
+
+       [DCCP_RESET_CODE_NO_CONNECTION]      = ECONNREFUSED,
+       [DCCP_RESET_CODE_CONNECTION_REFUSED] = ECONNREFUSED,
+       [DCCP_RESET_CODE_TOO_BUSY]           = EUSERS,
+       [DCCP_RESET_CODE_AGGRESSION_PENALTY] = EDQUOT,
+
+       [DCCP_RESET_CODE_PACKET_ERROR]       = ENOMSG,
+       [DCCP_RESET_CODE_BAD_INIT_COOKIE]    = EBADR,
+       [DCCP_RESET_CODE_BAD_SERVICE_CODE]   = EBADRQC,
+       [DCCP_RESET_CODE_OPTION_ERROR]       = EILSEQ,
+       [DCCP_RESET_CODE_MANDATORY_ERROR]    = EOPNOTSUPP,
+       };
+
+       return code >= DCCP_MAX_RESET_CODES ? 0 : error_code[code];
+}
+
+static void dccp_rcv_reset(struct sock *sk, struct sk_buff *skb)
+{
+       u8 err = dccp_reset_code_convert(dccp_hdr_reset(skb)->dccph_reset_code);
+
+       sk->sk_err = err;
+
+       /* Queue the equivalent of TCP fin so that dccp_recvmsg exits the loop */
+       dccp_fin(sk, skb);
+
+       if (err && !sock_flag(sk, SOCK_DEAD))
+               sk_wake_async(sk, 0, POLL_ERR);
+       dccp_time_wait(sk, DCCP_TIME_WAIT, 0);
+}
+
 static void dccp_event_ack_recv(struct sock *sk, struct sk_buff *skb)
 {
        struct dccp_sock *dp = dccp_sk(sk);
@@ -67,6 +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);
@@ -173,8 +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);
@@ -191,9 +243,8 @@ static int __dccp_rcv_established(struct sock *sk, struct sk_buff *skb,
                 *              S.state := TIMEWAIT
                 *              Set TIMEWAIT timer
                 *              Drop packet and return
-               */
-               dccp_fin(sk, skb);
-               dccp_time_wait(sk, DCCP_TIME_WAIT, 0);
+                */
+               dccp_rcv_reset(sk, skb);
                return 0;
        case DCCP_PKT_CLOSEREQ:
                dccp_rcv_closereq(sk, skb);
@@ -265,9 +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:
@@ -508,8 +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);
        }
 
        /*
@@ -521,12 +569,7 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
         *              Drop packet and return
        */
        if (dh->dccph_type == DCCP_PKT_RESET) {
-               /*
-                * Queue the equivalent of TCP fin so that dccp_recvmsg
-                * exits the loop
-                */
-               dccp_fin(sk, skb);
-               dccp_time_wait(sk, DCCP_TIME_WAIT, 0);
+               dccp_rcv_reset(sk, skb);
                return 0;
                /*
                 *   Step 7: Check for unexpected packet types