Fix bridge backoff calculation.

ChangeLog.txt

@@ -19,6 +19,7 @@ Broker:
 - Fix messages to `$` prefixed topics being rejected. Closes #2111.
 - Fix QoS 0 messages not being delivered when max_queued_bytes was configured.
  Closes #2123.
+- Fix bridge increasing backoff calculation.
 
 Client library:
 - Fix encrypted connections incorrectly connecting when the CA file passed to

src/bridge.c

@@ -645,11 +645,11 @@ void bridge__packet_cleanup(struct mosquitto *context)
  packet__cleanup(&(context->in_packet));
 }
 
-static int rand_between(int base, int cap)
+static int rand_between(int low, int high)
 {
  int r;
  util__random_bytes(&r, sizeof(int));
- return (r % (cap - base)) + base;
+ return (abs(r) % (high - low)) + low;
 }
 
 static void bridge__backoff_step(struct mosquitto *context)
@@ -684,6 +684,33 @@ static void bridge__backoff_reset(struct mosquitto *context)
  }
 }
 
+
+static void bridge_check_pending(struct mosquitto *context)
+{
+ int err;
+ socklen_t len;
+
+ if(context->state == mosq_cs_connect_pending){
+ len = sizeof(int);
+ if(!getsockopt(context->sock, SOL_SOCKET, SO_ERROR, (char *)&err, &len)){
+ if(err == 0){
+ mosquitto__set_state(context, mosq_cs_new);
+#if defined(WITH_ADNS) && defined(WITH_BRIDGE)
+ if(context->bridge){
+ bridge__connect_step3(context);
+ }
+#endif
+ }else if(err == ECONNREFUSED){
+ do_disconnect(context, MOSQ_ERR_CONN_LOST);
+ return;
+ }
+ }else{
+ do_disconnect(context, MOSQ_ERR_CONN_LOST);
+ return;
+ }
+ }
+}
+
 void bridge_check(void)
 {
  static time_t last_check = 0;
@@ -702,6 +729,7 @@ void bridge_check(void)
 
  if(context->sock != INVALID_SOCKET){
  mosquitto__check_keepalive(context);
+ bridge_check_pending(context);
 
  /* Check for bridges that are not round robin and not currently
  * connected to their primary broker. */