Change maxsessions feature behaviour

*  0 will allow 0 sessions (e.g. can be used for draining rtpengine)
* -1 will disable the feature and will be treated the same way as if
MAX_SESSIONS variable has not been set via configuration file
(or has been set to -1 in configuration file)
* < -1 will not be taken into consideration
* add check for minint range also

daemon/call_interfaces.c

@@ -752,7 +752,7 @@ out:
 const char *call_offer_ng(bencode_item_t *input, struct callmaster *m, bencode_item_t *output, const char* addr,
 		const struct sockaddr_in6 *sin)
 {
-	if (m->conf.max_sessions>0) {
+	if (m->conf.max_sessions>=0) {
 		rwlock_lock_r(&m->hashlock);
 		if (g_hash_table_size(m->callhash) >= m->conf.max_sessions) {
 			rwlock_unlock_r(&m->hashlock);

daemon/cli.c

@@ -286,6 +286,8 @@ static void cli_incoming_set_maxopenfiles(char* buffer, int len, struct callmast
 static void cli_incoming_set_maxsessions(char* buffer, int len, struct callmaster* m, char* replybuffer, const char* outbufend) {
 	int printlen = 0;
 	int maxsessions_num;
+	int err = 0x80000000;
+	int disabled = -1;
 	str maxsessions;
 
 	if (len<=1) {
@@ -297,22 +299,27 @@ static void cli_incoming_set_maxsessions(char* buffer, int len, struct callmaste
 	++buffer; --len; // one space
 	maxsessions.s = buffer;
 	maxsessions.len = len;
-	maxsessions_num = str_to_i(&maxsessions, -1);
+	maxsessions_num = str_to_i(&maxsessions, err);
 
-	if (maxsessions_num == -1) {
+	if (maxsessions_num == err) {
 		printlen = snprintf (replybuffer,(outbufend-replybuffer), "Fail setting maxsessions to %.*s; not an integer\n", maxsessions.len, maxsessions.s);
 		ADJUSTLEN(printlen,outbufend,replybuffer);
-		return;
-	} else if (maxsessions_num < 0) {
-		printlen = snprintf (replybuffer,(outbufend-replybuffer), "Fail setting maxsessions to %d; negative value\n", maxsessions_num);
+	} else if (maxsessions_num < disabled) {
+		printlen = snprintf (replybuffer,(outbufend-replybuffer), "Fail setting maxsessions to %d; either positive or -1 values allowed\n", maxsessions_num);
+		ADJUSTLEN(printlen,outbufend,replybuffer);
+	} else if (maxsessions_num == disabled) {
+		/* don't lock anything while writing the value - only this command modifies its value */
+		m->conf.max_sessions = maxsessions_num;
+		printlen = snprintf (replybuffer,(outbufend-replybuffer), "Success setting maxsessions to %d; disable feature\n", maxsessions_num);
 		ADJUSTLEN(printlen,outbufend,replybuffer);
-		return;
 	} else {
 		/* don't lock anything while writing the value - only this command modifies its value */
 		m->conf.max_sessions = maxsessions_num;
 		printlen = snprintf (replybuffer,(outbufend-replybuffer), "Success setting maxsessions to %d\n", maxsessions_num);
 		ADJUSTLEN(printlen,outbufend,replybuffer);
 	}
+
+	return;
 }
 
 static void cli_incoming_list(char* buffer, int len, struct callmaster* m, char* replybuffer, const char* outbufend) {

daemon/main.c

@@ -72,7 +72,7 @@ static int timeout;
 static int silent_timeout;
 static int port_min = 30000;
 static int port_max = 40000;
-static int max_sessions = 0;
+static int max_sessions = -1;
 static u_int32_t redis_ip;
 static u_int16_t redis_port;
 static int redis_db = -1;
@@ -530,6 +530,9 @@ no_kernel:
 	mc.interfaces = &interfaces;
 	mc.port_min = port_min;
 	mc.port_max = port_max;
+	if (max_sessions < -1) {
+		max_sessions = -1;
+	}
 	mc.max_sessions = max_sessions;
 	mc.timeout = timeout;
 	mc.silent_timeout = silent_timeout;

daemon/str.h

@@ -248,6 +248,7 @@ INLINE int str_to_i(str *s, int def) {
 	char c, *ep;
 	long ret;
 	int maxint = 0x7FFFFFFF;
+	int minint = 0x80000000;
 	if (s->len <= 0)
 		return def;
 	c = s->s[s->len];
@@ -258,6 +259,8 @@ INLINE int str_to_i(str *s, int def) {
 		return def;
 	if (ret > maxint)
 		return def;
+	if (ret < minint)
+		return def;
 	return ret;
 }