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, 24 insertions, 13 deletions

diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index ba63f22..5484113 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -468,9 +468,9 @@ enum rxrpc_call_flag {
 enum rxrpc_call_event {
 	RXRPC_CALL_EV_ACK,		/* need to generate ACK */
 	RXRPC_CALL_EV_ABORT,		/* need to generate abort */
-	RXRPC_CALL_EV_TIMER,		/* Timer expired */
 	RXRPC_CALL_EV_RESEND,		/* Tx resend required */
 	RXRPC_CALL_EV_PING,		/* Ping send required */
+	RXRPC_CALL_EV_EXPIRED,		/* Expiry occurred */
 };
 
 /*
@@ -514,10 +514,14 @@ struct rxrpc_call {
 	struct rxrpc_peer	*peer;		/* Peer record for remote address */
 	struct rxrpc_sock __rcu	*socket;	/* socket responsible */
 	struct mutex		user_mutex;	/* User access mutex */
-	ktime_t			ack_at;		/* When deferred ACK needs to happen */
-	ktime_t			resend_at;	/* When next resend needs to happen */
-	ktime_t			ping_at;	/* When next to send a ping */
-	ktime_t			expire_at;	/* When the call times out */
+	unsigned long		ack_at;		/* When deferred ACK needs to happen */
+	unsigned long		resend_at;	/* When next resend needs to happen */
+	unsigned long		ping_at;	/* When next to send a ping */
+	unsigned long		expect_rx_by;	/* When we expect to get a packet by */
+	unsigned long		expect_req_by;	/* When we expect to get a request DATA packet by */
+	unsigned long		expect_term_by;	/* When we expect call termination by */
+	u32			next_rx_timo;	/* Timeout for next Rx packet (jif) */
+	u32			next_req_timo;	/* Timeout for next Rx request packet (jif) */
 	struct timer_list	timer;		/* Combined event timer */
 	struct work_struct	processor;	/* Event processor */
 	rxrpc_notify_rx_t	notify_rx;	/* kernel service Rx notification function */
@@ -697,12 +701,19 @@ int rxrpc_reject_call(struct rxrpc_sock *);
 /*
  * call_event.c
  */
-void __rxrpc_set_timer(struct rxrpc_call *, enum rxrpc_timer_trace, ktime_t);
-void rxrpc_set_timer(struct rxrpc_call *, enum rxrpc_timer_trace, ktime_t);
 void rxrpc_propose_ACK(struct rxrpc_call *, u8, u16, u32, bool, bool,
 		       enum rxrpc_propose_ack_trace);
 void rxrpc_process_call(struct work_struct *);
 
+static inline void rxrpc_reduce_call_timer(struct rxrpc_call *call,
+					   unsigned long expire_at,
+					   unsigned long now,
+					   enum rxrpc_timer_trace why)
+{
+	trace_rxrpc_timer(call, why, now);
+	timer_reduce(&call->timer, expire_at);
+}
+
 /*
  * call_object.c
  */
@@ -843,8 +854,8 @@ static inline bool __rxrpc_abort_eproto(struct rxrpc_call *call,
  */
 extern unsigned int rxrpc_max_client_connections;
 extern unsigned int rxrpc_reap_client_connections;
-extern unsigned int rxrpc_conn_idle_client_expiry;
-extern unsigned int rxrpc_conn_idle_client_fast_expiry;
+extern unsigned long rxrpc_conn_idle_client_expiry;
+extern unsigned long rxrpc_conn_idle_client_fast_expiry;
 extern struct idr rxrpc_client_conn_ids;
 
 void rxrpc_destroy_client_conn_ids(void);
@@ -976,13 +987,13 @@ static inline void rxrpc_queue_local(struct rxrpc_local *local)
  * misc.c
  */
 extern unsigned int rxrpc_max_backlog __read_mostly;
-extern unsigned int rxrpc_requested_ack_delay;
-extern unsigned int rxrpc_soft_ack_delay;
-extern unsigned int rxrpc_idle_ack_delay;
+extern unsigned long rxrpc_requested_ack_delay;
+extern unsigned long rxrpc_soft_ack_delay;
+extern unsigned long rxrpc_idle_ack_delay;
 extern unsigned int rxrpc_rx_window_size;
 extern unsigned int rxrpc_rx_mtu;
 extern unsigned int rxrpc_rx_jumbo_max;
-extern unsigned int rxrpc_resend_timeout;
+extern unsigned long rxrpc_resend_timeout;
 
 extern const s8 rxrpc_ack_priority[];