rxrpc: Fix call timeouts

Fix the rxrpc call expiration timeouts and make them settable from
userspace.  By analogy with other rx implementations, there should be three
timeouts:

 (1) "Normal timeout"

     This is set for all calls and is triggered if we haven't received any
     packets from the peer in a while.  It is measured from the last time
     we received any packet on that call.  This is not reset by any
     connection packets (such as CHALLENGE/RESPONSE packets).

     If a service operation takes a long time, the server should generate
     PING ACKs at a duration that's substantially less than the normal
     timeout so is to keep both sides alive.  This is set at 1/6 of normal
     timeout.

 (2) "Idle timeout"

     This is set only for a service call and is triggered if we stop
     receiving the DATA packets that comprise the request data.  It is
     measured from the last time we received a DATA packet.

 (3) "Hard timeout"

     This can be set for a call and specified the maximum lifetime of that
     call.  It should not be specified by default.  Some operations (such
     as volume transfer) take a long time.

Allow userspace to set/change the timeouts on a call with sendmsg, using a
control message:

	RXRPC_SET_CALL_TIMEOUTS

The data to the message is a number of 32-bit words, not all of which need
be given:

	u32 hard_timeout;	/* sec from first packet */
	u32 idle_timeout;	/* msec from packet Rx */
	u32 normal_timeout;	/* msec from data Rx */

This can be set in combination with any other sendmsg() that affects a
call.

Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 30 insertions, 4 deletions

diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index 1b592073ec96..c89647eae86d 100644
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -318,16 +318,18 @@ bad_state:
 static bool rxrpc_receiving_reply(struct rxrpc_call *call)
 {
 	struct rxrpc_ack_summary summary = { 0 };
+	unsigned long now, timo;
 	rxrpc_seq_t top = READ_ONCE(call->tx_top);
 
 	if (call->ackr_reason) {
 		spin_lock_bh(&call->lock);
 		call->ackr_reason = 0;
-		call->resend_at = call->expire_at;
-		call->ack_at = call->expire_at;
 		spin_unlock_bh(&call->lock);
-		rxrpc_set_timer(call, rxrpc_timer_init_for_reply,
-				ktime_get_real());
+		now = jiffies;
+		timo = now + MAX_JIFFY_OFFSET;
+		WRITE_ONCE(call->resend_at, timo);
+		WRITE_ONCE(call->ack_at, timo);
+		trace_rxrpc_timer(call, rxrpc_timer_init_for_reply, now);
 	}
 
 	if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags))
@@ -437,6 +439,19 @@ static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb,
 	if (state >= RXRPC_CALL_COMPLETE)
 		return;
 
+	if (call->state == RXRPC_CALL_SERVER_RECV_REQUEST) {
+		unsigned long timo = READ_ONCE(call->next_req_timo);
+		unsigned long now, expect_req_by;
+
+		if (timo) {
+			now = jiffies;
+			expect_req_by = now + timo;
+			WRITE_ONCE(call->expect_req_by, expect_req_by);
+			rxrpc_reduce_call_timer(call, expect_req_by, now,
+						rxrpc_timer_set_for_idle);
+		}
+	}
+
 	/* Received data implicitly ACKs all of the request packets we sent
 	 * when we're acting as a client.
 	 */
@@ -908,9 +923,20 @@ static void rxrpc_input_call_packet(struct rxrpc_call *call,
 				    struct sk_buff *skb, u16 skew)
 {
 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+	unsigned long timo;
 
 	_enter("%p,%p", call, skb);
 
+	timo = READ_ONCE(call->next_rx_timo);
+	if (timo) {
+		unsigned long now = jiffies, expect_rx_by;
+
+		expect_rx_by = jiffies + timo;
+		WRITE_ONCE(call->expect_rx_by, expect_rx_by);
+		rxrpc_reduce_call_timer(call, expect_rx_by, now,
+					rxrpc_timer_set_for_normal);
+	}
+	
 	switch (sp->hdr.type) {
 	case RXRPC_PACKET_TYPE_DATA:
 		rxrpc_input_data(call, skb, skew);