[Swan-dev] pluto: Do not retransmit forever

[Herbert Xu]

The commit 09de73638a62207c268482982fce7ee96a9d6ba1 ("pluto:
first attempt to replace pluto select loop with libevent") causes
pluto to retransmit forever.

This patch fixes this by stopping retransmissions after the count
reaches MAXIMUM_RETRANSMITS_PER_EXCHANGE.

diff --git a/programs/pluto/timer.c b/programs/pluto/timer.c
index 700b018..f4299a9 100644
--- a/programs/pluto/timer.c
+++ b/programs/pluto/timer.c
@@ -62,6 +62,9 @@ static unsigned long retrans_delay(struct state *st, unsigned long delay_ms)
 	unsigned long delay_cap = deltamillisecs(c->r_timeout); /* ms */
 	u_int8_t x = st->st_retransmit++;	/* ??? odd type */
 
+	if (x > MAXIMUM_RETRANSMITS_PER_EXCHANGE)
+		return 0;
+
 	/*
 	 * Very carefully calculate capped exponential backoff.
 	 * The test is expressed as a right shift to avoid overflow.
@@ -70,8 +73,7 @@ static unsigned long retrans_delay(struct state *st, unsigned long delay_ms)
 	 * Surely a bound of 12 (factor of 2048) is safe and more than enough.
 	 */
 
-	delay_ms = (x > MAXIMUM_RETRANSMITS_PER_EXCHANGE ||
-			delay_cap >> x < delay_ms) ?
+	delay_ms = delay_cap >> x < delay_ms ?
 		delay_cap : delay_ms << x;
 
 	whack_log(RC_RETRANSMISSION,
@@ -128,8 +130,10 @@ static void retransmit_v1_msg(struct state *st)
 		delay_ms = c->r_interval;
 	}
 
+	if (delay_ms != 0)
+		delay_ms = retrans_delay(st, delay_ms);
+
 	if (delay_ms != 0) {
-		delay_ms =  retrans_delay(st, delay_ms);
 		resend_ike_v1_msg(st, "EVENT_v1_RETRANSMIT");
 		event_schedule_ms(EVENT_v1_RETRANSMIT, delay_ms, st);
 	} else {
@@ -241,8 +245,10 @@ static void retransmit_v2_msg(struct state *st)
 		delay_ms = c->r_interval;
 	}
 
+	if (delay_ms != 0)
+		delay_ms = retrans_delay(st, delay_ms);
+
 	if (delay_ms != 0) {
-		delay_ms =  retrans_delay(st, delay_ms);
 		send_ike_msg(st, "EVENT_v2_RETRANSMIT");
 		event_schedule_ms(EVENT_v2_RETRANSMIT, delay_ms, st);
 		return;
-- 
Email: Herbert Xu <herbert at gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt