xhttp: allow chaining with xmlrpc module

- new parameter url_skip to skip execution of xhttp event route if the
  HTTP URL matches the regexp
- e.g., allow to execute all HTTP requests to /RPC2 via xmlrpc module
  with skip_url="^/RPC2"

modules/xhttp/README

@@ -25,7 +25,8 @@ Daniel-Constantin Mierla
 
         3. Exported Parameters
 
-              3.1. url_match (str)
+              3.1. url_skip (str)
+              3.2. url_match (str)
 
         4. Exported Functions
 
@@ -33,8 +34,9 @@ Daniel-Constantin Mierla
 
    List of Examples
 
-   1.1. Set url_match parameter
-   1.2. xhttp_reply usage
+   1.1. Set url_skip parameter
+   1.2. Set url_match parameter
+   1.3. xhttp_reply usage
 
 Chapter 1. Admin Guide
 
@@ -48,7 +50,8 @@ Chapter 1. Admin Guide
 
    3. Exported Parameters
 
-        3.1. url_match (str)
+        3.1. url_skip (str)
+        3.2. url_match (str)
 
    4. Exported Functions
 
@@ -83,16 +86,31 @@ Chapter 1. Admin Guide
 
 3. Exported Parameters
 
-   3.1. url_match (str)
+   3.1. url_skip (str)
+   3.2. url_match (str)
 
-3.1. url_match (str)
+3.1. url_skip (str)
+
+   Regular expression to match the HTPP URL. If there is match, then event
+   route is not executed.
+
+   Default value is null (don't skip).
+
+   Example 1.1. Set url_skip parameter
+...
+modparam("xhttp", "url_skip", "^/RPC2")
+...
+
+3.2. url_match (str)
 
    Regular expression to match the HTPP URL. If there is no match, then
-   event route is not executed
+   event route is not executed. This check is done after url_skip, so if
+   both url_skip and url_match would match then the event route is not
+   executed (url_skip has higher priority).
 
    Default value is null (match everything).
 
-   Example 1.1. Set url_match parameter
+   Example 1.2. Set url_match parameter
 ...
 modparam("xhttp", "url_match", "^/sip/")
 ...
@@ -105,7 +123,7 @@ modparam("xhttp", "url_match", "^/sip/")
 
    Send back a reply with content-type and body.
 
-   Example 1.2. xhttp_reply usage
+   Example 1.3. xhttp_reply usage
 ...
 event_route[xhttp:request] {
     xhttp_reply("200", "OK", "text/html",

modules/xhttp/doc/xhttp_admin.xml

@@ -60,11 +60,33 @@
 	</section>
 	<section>
 	<title>Exported Parameters</title>
+	<section>
+		<title><varname>url_skip</varname> (str)</title>
+		<para>
+			Regular expression to match the HTPP URL. If there is match,
+			then event route is not executed.
+		</para>
+		<para>
+		<emphasis>
+			Default value is null (don't skip).
+		</emphasis>
+		</para>
+		<example>
+		<title>Set <varname>url_skip</varname> parameter</title>
+		<programlisting format="linespecific">
+...
+modparam("xhttp", "url_skip", "^/RPC2")
+...
+</programlisting>
+		</example>
+	</section>
 	<section>
 		<title><varname>url_match</varname> (str)</title>
 		<para>
 			Regular expression to match the HTPP URL. If there is no match,
-			then event route is not executed
+			then event route is not executed. This check is done after
+			url_skip, so if both url_skip and url_match would match then
+			the event route is not executed (url_skip has higher priority).
 		</para>
 		<para>
 		<emphasis>

modules/xhttp/xhttp_mod.c

@@ -58,7 +58,9 @@ static int pv_get_huri(struct sip_msg *msg, pv_param_t *param,
 
 static int xhttp_route_no=DEFAULT_RT;
 static char* xhttp_url_match = NULL;
-static regex_t xhttp_url_regexp;
+static regex_t xhttp_url_match_regexp;
+static char* xhttp_url_skip = NULL;
+static regex_t xhttp_url_skip_regexp;
 
 /** SL API structure */
 sl_api_t slb;
@@ -80,6 +82,7 @@ static pv_export_t mod_pvs[] = {
 
 static param_export_t params[] = {
 	{"url_match",       STR_PARAM, &xhttp_url_match},
+	{"url_skip",        STR_PARAM, &xhttp_url_skip},
 	{0, 0, 0}
 };
 
@@ -138,9 +141,17 @@ static int mod_init(void)
 
 	if(xhttp_url_match!=NULL)
 	{
-		memset(&xhttp_url_regexp, 0, sizeof(regex_t));
-		if (regcomp(&xhttp_url_regexp, xhttp_url_match, REG_EXTENDED)!=0) {
-			LM_ERR("bad re %s\n", xhttp_url_match);
+		memset(&xhttp_url_match_regexp, 0, sizeof(regex_t));
+		if (regcomp(&xhttp_url_match_regexp, xhttp_url_match, REG_EXTENDED)!=0) {
+			LM_ERR("bad match re %s\n", xhttp_url_match);
+			return E_BAD_RE;
+		}
+	}
+	if(xhttp_url_skip!=NULL)
+	{
+		memset(&xhttp_url_skip_regexp, 0, sizeof(regex_t));
+		if (regcomp(&xhttp_url_skip_regexp, xhttp_url_skip, REG_EXTENDED)!=0) {
+			LM_ERR("bad skip re %s\n", xhttp_url_skip);
 			return E_BAD_RE;
 		}
 	}
@@ -292,12 +303,22 @@ static int xhttp_handler(sip_msg_t* msg)
 		return NONSIP_MSG_PASS;
 	}
 
-	if(xhttp_url_match!=NULL)
+	if(xhttp_url_skip!=NULL || xhttp_url_match!=NULL)
 	{
 		c = msg->first_line.u.request.uri.s[msg->first_line.u.request.uri.len];
 		msg->first_line.u.request.uri.s[msg->first_line.u.request.uri.len]
 			= '\0';
-		if (regexec(&xhttp_url_regexp, msg->first_line.u.request.uri.s,
+		if (xhttp_url_skip!=NULL &&
+			regexec(&xhttp_url_skip_regexp, msg->first_line.u.request.uri.s,
+					1, &pmatch, 0)==0)
+		{
+			LM_DBG("URL matched skip re\n");
+			msg->first_line.u.request.uri.s[msg->first_line.u.request.uri.len]
+				= c;
+			return NONSIP_MSG_PASS;
+		}
+		if (xhttp_url_match!=NULL &&
+			regexec(&xhttp_url_match_regexp, msg->first_line.u.request.uri.s,
 					1, &pmatch, 0)!=0)
 		{
 			LM_DBG("URL not matched\n");