linux-kernel - [PATCH 4.16 216/279] rxrpc: Fix missing start of call timeout

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Date:   Mon, 18 Jun 2018 10:13:21 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Marc Dionne <marc.dionne@...istor.com>,
        David Howells <dhowells@...hat.com>,
        Sasha Levin <alexander.levin@...rosoft.com>
Subject: [PATCH 4.16 216/279] rxrpc: Fix missing start of call timeout

4.16-stable review patch.  If anyone has any objections, please let me know.

------------------

From: David Howells <dhowells@...hat.com>

[ Upstream commit c54e43d752c7187595c8c62a231e0b0d53c7fded ]

The expect_rx_by call timeout is supposed to be set when a call is started
to indicate that we need to receive a packet by that point.  This is
currently put back every time we receive a packet, but it isn't started
when we first send a packet.  Without this, the call may wait forever if
the server doesn't deign to reply.

Fix this by setting the timeout upon a successful UDP sendmsg call for the
first DATA packet.  The timeout is initiated only for initial transmission
and not for subsequent retries as we don't want the retry mechanism to
extend the timeout indefinitely.

Fixes: a158bdd3247b ("rxrpc: Fix call timeouts")
Reported-by: Marc Dionne <marc.dionne@...istor.com>
Signed-off-by: David Howells <dhowells@...hat.com>
Signed-off-by: Sasha Levin <alexander.levin@...rosoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 net/rxrpc/ar-internal.h |    1 +
 net/rxrpc/input.c       |    2 +-
 net/rxrpc/output.c      |   11 +++++++++++
 net/rxrpc/sendmsg.c     |   10 ++++++++++
 4 files changed, 23 insertions(+), 1 deletion(-)

--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -464,6 +464,7 @@ enum rxrpc_call_flag {
 	RXRPC_CALL_SEND_PING,		/* A ping will need to be sent */
 	RXRPC_CALL_PINGING,		/* Ping in process */
 	RXRPC_CALL_RETRANS_TIMEOUT,	/* Retransmission due to timeout occurred */
+	RXRPC_CALL_BEGAN_RX_TIMER,	/* We began the expect_rx_by timer */
 };
 
 /*
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -971,7 +971,7 @@ static void rxrpc_input_call_packet(stru
 	if (timo) {
 		unsigned long now = jiffies, expect_rx_by;
 
-		expect_rx_by = jiffies + timo;
+		expect_rx_by = now + timo;
 		WRITE_ONCE(call->expect_rx_by, expect_rx_by);
 		rxrpc_reduce_call_timer(call, expect_rx_by, now,
 					rxrpc_timer_set_for_normal);
--- a/net/rxrpc/output.c
+++ b/net/rxrpc/output.c
@@ -407,6 +407,17 @@ done:
 							rxrpc_timer_set_for_lost_ack);
 			}
 		}
+
+		if (sp->hdr.seq == 1 &&
+		    !test_and_set_bit(RXRPC_CALL_BEGAN_RX_TIMER,
+				      &call->flags)) {
+			unsigned long nowj = jiffies, expect_rx_by;
+
+			expect_rx_by = nowj + call->next_rx_timo;
+			WRITE_ONCE(call->expect_rx_by, expect_rx_by);
+			rxrpc_reduce_call_timer(call, expect_rx_by, nowj,
+						rxrpc_timer_set_for_normal);
+		}
 	}
 
 	rxrpc_set_keepalive(call);
--- a/net/rxrpc/sendmsg.c
+++ b/net/rxrpc/sendmsg.c
@@ -223,6 +223,15 @@ static void rxrpc_queue_packet(struct rx
 
 	ret = rxrpc_send_data_packet(call, skb, false);
 	if (ret < 0) {
+		switch (ret) {
+		case -ENETUNREACH:
+		case -EHOSTUNREACH:
+		case -ECONNREFUSED:
+			rxrpc_set_call_completion(call,
+						  RXRPC_CALL_LOCAL_ERROR,
+						  0, ret);
+			goto out;
+		}
 		_debug("need instant resend %d", ret);
 		rxrpc_instant_resend(call, ix);
 	} else {
@@ -241,6 +250,7 @@ static void rxrpc_queue_packet(struct rx
 					rxrpc_timer_set_for_send);
 	}
 
+out:
 	rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
 	_leave("");
 }