+ make sure parse_uri never returns NULL pointers - this

simplifies its usage.

+ add another client for parse_uri, in handling Contact: strings
  (on passing, document the content of the "fullcontact" field);

+ in register_verify(), mark with XXX what i believe is another
  misinterpretation on the URI format when '@' is missing.
  No code changed here, so no fixes applied.



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@45977 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_sip.c

@@ -912,6 +912,7 @@ struct sip_pvt {
 		AST_STRING_FIELD(cid_name);	/*!< Caller*ID name */
 		AST_STRING_FIELD(via);		/*!< Via: header */
 		AST_STRING_FIELD(fullcontact);	/*!< The Contact: that the UA registers with us */
+			/* we only store the part in <brackets> in this field. */
 		AST_STRING_FIELD(our_contact);	/*!< Our contact header */
 		AST_STRING_FIELD(rpid);		/*!< Our RPID header */
 		AST_STRING_FIELD(rpid_from);	/*!< Our RPID From header */
@@ -2242,7 +2243,7 @@ static char *get_in_brackets(char *tmp)
  * name:pass and domain:port.
  * It is safe to call with ret_name, pass, domain, port
  * pointing all to the same place.
- *
+ * Init pointers to empty string so we never get NULL dereferencing.
  * Overwrites the string.
  * return 0 on success, other values on error.
  */
@@ -2254,9 +2255,9 @@ static int parse_uri(char *uri, char *scheme,
 
 	/* init field as required */
 	if (*pass)
-		*pass = NULL;
+		*pass = "";
 	if (*port)
-		*port = NULL;
+		*port = "";
 	name = strsep(&uri, ";");	/* remove options */
 	if (scheme) {
 		int l = strlen(scheme);
@@ -2275,12 +2276,12 @@ static int parse_uri(char *uri, char *scheme,
 		/* store the result in a temp. variable to avoid it being
 		 * overwritten if arguments point to the same place.
 		 */
-		char *c, *dom = NULL;
+		char *c, *dom = "";
 
 		if ((c = strchr(name, '@')) == NULL) {
 			/* domain-only URI, according to the SIP RFC. */
 			dom = name;
-			name = NULL;
+			name = "";
 		} else {
 			*c++ = '\0';
 			dom = c;
@@ -2289,7 +2290,7 @@ static int parse_uri(char *uri, char *scheme,
 			*c++ = '\0';
 			*port = c;
 		}
-		if (name && pass && (c = strchr(name, ':'))) {	/* user:password */
+		if (pass && (c = strchr(name, ':'))) {	/* user:password */
 			*c++ = '\0';
 			*pass = c;
 		}
@@ -2298,7 +2299,7 @@ static int parse_uri(char *uri, char *scheme,
 	if (ret_name)	/* same as for domain, store the result only at the end */
 		*ret_name = name;
 	if (options)
-		*options = uri;
+		*options = uri ? uri : "";
 
 	return error;
 }
@@ -7590,7 +7591,7 @@ static int set_address_from_contact(struct sip_pvt *pvt)
 	struct hostent *hp;
 	struct ast_hostent ahp;
 	int port;
-	char *c, *host, *pt;
+	char *host, *pt;
 	char *contact;
 
 
@@ -7604,32 +7605,12 @@ static int set_address_from_contact(struct sip_pvt *pvt)
 
 	/* Work on a copy */
 	contact = ast_strdupa(pvt->fullcontact);
+	/* We have only the part in <brackets> here so we just need to parse a SIP URI.*/
 
-	/* XXX this code is repeated all over */
-	/* Make sure it's a SIP URL */
-	if (strncasecmp(contact, "sip:", 4)) {
+	if (parse_uri(contact, "sip:", &contact, NULL, &host, &pt, NULL))
 		ast_log(LOG_NOTICE, "'%s' is not a valid SIP contact (missing sip:) trying to use anyway\n", contact);
-	} else
-		contact += 4;
-
-	/* Ditch arguments */
-	/* XXX this code is replicated also shortly below */
-	contact = strsep(&contact, ";");	/* trim ; and beyond */
-
-	/* Grab host */
-	host = strchr(contact, '@');
-	if (!host) {	/* No username part */
-		host = contact;
-		c = NULL;
-	} else {
-		*host++ = '\0';
-	}
-	pt = strchr(host, ':');
-	if (pt) {
-		*pt++ = '\0';
-		port = atoi(pt);
-	} else
-		port = STANDARD_SIP_PORT;
+	port = !ast_strlen_zero(pt) ? atoi(pt) : STANDARD_SIP_PORT;
+	ast_verbose("--- set_address_from_contact host '%s'\n", host);
 
 	/* XXX This could block for a long time XXX */
 	/* We should only do this if it's a name, not an IP */
@@ -8193,6 +8174,9 @@ static enum check_auth_result register_verify(struct sip_pvt *p, struct sockaddr
 		ast_log(LOG_NOTICE, "Invalid to address: '%s' from %s (missing sip:) trying to use anyway...\n", c, ast_inet_ntoa(sin->sin_addr));
 	}
 
+	/* XXX here too we interpret a missing @domain as a name-only
+	 * URI, whereas the RFC says this is a domain-only uri.
+	 */
 	/* Strip off the domain name */
 	if ((c = strchr(name, '@'))) {
 		*c++ = '\0';
@@ -9233,7 +9217,7 @@ static enum check_auth_result check_user_full(struct sip_pvt *p, struct sip_requ
 	if (parse_uri(of, "sip:", &of, &dummy, &domain, &dummy, &dummy)) {
 		ast_log(LOG_NOTICE, "From address missing 'sip:', using it anyway\n");
 	}
-	if (of == NULL) {
+	if (ast_strlen_zero(of)) {
 		/* XXX note: the original code considered a missing @host
 		 * as a username-only URI. The SIP RFC (19.1.1) says that
 		 * this is wrong, and it should be considered as a domain-only URI.