--resolve FS-5432

conf/vanilla/sip_profiles/internal.xml

@@ -311,6 +311,10 @@
 
     <!--force suscription expires to a lower value than requested-->
     <!--<param name="force-subscription-expires" value="60"/>-->
+
+    <!-- add a random deviation to the expires value of the 202 Accepted -->
+    <!--<param name="sip-subscription-max-deviation" value="120"/>-->
+
     <!-- disable register and transfer which may be undesirable in a public switch -->
     <!--<param name="disable-transfer" value="true"/>-->
     <!--<param name="disable-register" value="true"/>-->

src/mod/endpoints/mod_sofia/conf/sofia.conf.xml

@@ -353,6 +353,10 @@
 
         <!-- force suscription expires to a lower value than requested -->
         <!-- <param name="force-subscription-expires" value="60"/> -->
+
+        <!-- add a random deviation to the expires value of the 202 Accepted -->
+        <!--<param name="sip-subscription-max-deviation" value="120"/>-->
+
         <!-- disable register and transfer which may be undesirable in a public
              switch -->
         <!-- <param name="disable-transfer" value="true"/> -->

src/mod/endpoints/mod_sofia/mod_sofia.h

@@ -672,6 +672,7 @@ struct sofia_profile {
 	su_strlst_t *tls_verify_in_subjects;
 	uint32_t sip_force_expires;
 	uint32_t sip_expires_max_deviation;
+	uint32_t sip_subscription_max_deviation;
 	int ireg_seconds;
 	sofia_paid_type_t paid_type;
 	uint32_t rtp_digit_delay;

src/mod/endpoints/mod_sofia/sofia.c

@@ -3685,6 +3685,7 @@ switch_status_t config_sofia(sofia_config_t reload, char *profile_name)
 					profile->rtp_digit_delay = 40;
 					profile->sip_force_expires = 0;
 					profile->sip_expires_max_deviation = 0;
+					profile->sip_subscription_max_deviation = 0;
 					profile->tls_version = 0;
 					profile->tls_timeout = 300;
 					profile->mflags = MFLAG_REFER | MFLAG_REGISTER;
@@ -4635,6 +4636,13 @@ switch_status_t config_sofia(sofia_config_t reload, char *profile_name)
 						} else {
 							profile->sip_expires_max_deviation = 0;
 						}
+					} else if (!strcasecmp(var, "sip-subscription-max-deviation")) {
+						int32_t sip_subscription_max_deviation = atoi(val);
+						if (sip_subscription_max_deviation >= 0) {
+							profile->sip_subscription_max_deviation = sip_subscription_max_deviation;
+						} else {
+							profile->sip_subscription_max_deviation = 0;
+						}
 					} else if (!strcasecmp(var, "reuse-connections")) {
 						switch_bool_t value = switch_true(val);
 						if (!value) {

src/mod/endpoints/mod_sofia/sofia_presence.c

@@ -3516,6 +3516,7 @@ void sofia_presence_handle_sip_i_subscribe(int status,
 
 	long exp_delta = 0;
 	char exp_delta_str[30] = "";
+	uint32_t sub_max_deviation_var = 0;
 	sip_to_t const *to;
 	const char *from_user = NULL, *from_host = NULL;
 	const char *to_user = NULL, *to_host = NULL;
@@ -3615,6 +3616,18 @@ void sofia_presence_handle_sip_i_subscribe(int status,
 		}
 	}
 
+	if ((sub_max_deviation_var = profile->sip_subscription_max_deviation)) {
+		if (sub_max_deviation_var > 0) {
+			int sub_deviation;
+			srand( (unsigned) ( (unsigned)(intptr_t)switch_thread_self() + switch_micro_time_now() ) );
+			/* random negative number between 0 and negative sub_max_deviation_var: */
+			sub_deviation = ( rand() % sub_max_deviation_var ) - sub_max_deviation_var;
+			if ( (exp_delta + sub_deviation) > 45 ) {
+				exp_delta += sub_deviation;
+			}
+		}
+	}
+
 	if (mod_sofia_globals.debug_presence > 0 || mod_sofia_globals.debug_sla > 0) {
 		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "DELTA %ld\n", exp_delta);
 	}