b2b_entities: add more randomness to callid generation to handle client_htable collisions

Author: Giedriusj1

modules/b2b_entities/b2be_load.h

@@ -55,7 +55,7 @@
 #define B2B_NOTIFY_FL_TERM_BYE   (1<<2)
 
 #define B2B_MAX_PREFIX_LEN    5
-#define B2B_MAX_KEY_SIZE	(B2B_MAX_PREFIX_LEN+4+10+10+INT2STR_MAX_LEN)
+#define B2B_MAX_KEY_SIZE	(B2B_MAX_PREFIX_LEN+5+10+10+INT2STR_MAX_LEN+10)
 
 enum b2b_entity_type {B2B_SERVER=0, B2B_CLIENT, B2B_NONE};
 

modules/b2b_entities/dlg.c

@@ -290,7 +290,7 @@ str* b2b_htable_insert(b2b_table table, b2b_dlg_t* dlg, int hash_index,
 	return b2b_key;
 }
 
-/* key format : B2B.hash_index.local_index.timestamp *
+/* key format : B2B.hash_index.local_index.timestamp.random *
  */
 
 int b2b_parse_key(str* key, unsigned int* hash_index, unsigned int* local_index,
@@ -341,8 +341,14 @@ int b2b_parse_key(str* key, unsigned int* hash_index, unsigned int* local_index,
 	}
 
 	if (timestamp) {
-		s.s = p+1;
-		s.len = key->len - (s.s - key->s);
+	        s.s = p+1;
+	        // There might be a random number after timestamp, we want to ignore it.
+		p= strchr(s.s, '.');
+		if (p != NULL) {
+		    s.len= p - s.s;
+		} else {
+		    s.len = key->len - (s.s - key->s);
+		}
 		if(str2int64(&s, timestamp) < 0)
 		{
 			LM_DBG("Could not extract timestamp [%.*s] from key [%.*s]\n", s.len, s.s, key->len, key->s);
@@ -366,8 +372,8 @@ str* b2b_generate_key(unsigned int hash_index, unsigned int local_index,
 	str* b2b_key;
 	int len;
 
-	len = sprintf(buf, "%s.%d.%d.%ld", b2b_key_prefix.s, hash_index, local_index,
-		timestamp ? timestamp : startup_time+get_ticks());
+	len = sprintf(buf, "%s.%d.%d.%ld.%d", b2b_key_prefix.s, hash_index, local_index,
+		      timestamp ? timestamp : startup_time+get_ticks(), rand());
 
 	b2b_key = (str*)pkg_malloc(sizeof(str)+ len);
 	if(b2b_key== NULL)