rxrpc: Add keepalive for a call

[sfrench/cifs-2.6.git] / net / rxrpc / output.c

diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c
index f47659c7b224ef910fcaa7f8c9271d449ae3eada..42410e910affbdf39691a0cb080c053b1e8aa661 100644 (file)
--- a/net/rxrpc/output.c
+++ b/net/rxrpc/output.c
@@ -32,6 +32,24 @@ struct rxrpc_abort_buffer {
        __be32 abort_code;
 };
 
+/*
+ * Arrange for a keepalive ping a certain time after we last transmitted.  This
+ * lets the far side know we're still interested in this call and helps keep
+ * the route through any intervening firewall open.
+ *
+ * Receiving a response to the ping will prevent the ->expect_rx_by timer from
+ * expiring.
+ */
+static void rxrpc_set_keepalive(struct rxrpc_call *call)
+{
+       unsigned long now = jiffies, keepalive_at = call->next_rx_timo / 6;
+
+       keepalive_at += now;
+       WRITE_ONCE(call->keepalive_at, keepalive_at);
+       rxrpc_reduce_call_timer(call, keepalive_at, now,
+                               rxrpc_timer_set_for_keepalive);
+}
+
 /*
  * Fill out an ACK packet.
  */
@@ -95,7 +113,8 @@ static size_t rxrpc_fill_out_ack(struct rxrpc_connection *conn,
 /*
  * Send an ACK call packet.
  */
-int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping)
+int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping,
+                         rxrpc_serial_t *_serial)
 {
        struct rxrpc_connection *conn = NULL;
        struct rxrpc_ack_buffer *pkt;
@@ -165,6 +184,8 @@ int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping)
                           ntohl(pkt->ack.firstPacket),
                           ntohl(pkt->ack.serial),
                           pkt->ack.reason, pkt->ack.nAcks);
+       if (_serial)
+               *_serial = serial;
 
        if (ping) {
                call->ping_serial = serial;
@@ -202,6 +223,8 @@ int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping)
                                call->ackr_seen = top;
                        spin_unlock_bh(&call->lock);
                }
+
+               rxrpc_set_keepalive(call);
        }
 
 out:
@@ -323,7 +346,8 @@ int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb,
         * ACKs if a DATA packet appears to have been lost.
         */
        if (!(sp->hdr.flags & RXRPC_LAST_PACKET) &&
-           (retrans ||
+           (test_and_clear_bit(RXRPC_CALL_EV_ACK_LOST, &call->events) ||
+            retrans ||
             call->cong_mode == RXRPC_CALL_SLOW_START ||
             (call->peer->rtt_usage < 3 && sp->hdr.seq & 1) ||
             ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000),
@@ -370,8 +394,23 @@ done:
                if (whdr.flags & RXRPC_REQUEST_ACK) {
                        call->peer->rtt_last_req = now;
                        trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_data, serial);
+                       if (call->peer->rtt_usage > 1) {
+                               unsigned long nowj = jiffies, ack_lost_at;
+
+                               ack_lost_at = nsecs_to_jiffies(2 * call->peer->rtt);
+                               if (ack_lost_at < 1)
+                                       ack_lost_at = 1;
+
+                               ack_lost_at += nowj;
+                               WRITE_ONCE(call->ack_lost_at, ack_lost_at);
+                               rxrpc_reduce_call_timer(call, ack_lost_at, nowj,
+                                                       rxrpc_timer_set_for_lost_ack);
+                       }
                }
        }
+
+       rxrpc_set_keepalive(call);
+
        _leave(" = %d [%u]", ret, call->peer->maxdata);
        return ret;