The get_pai function in chan_sip.c didn't recognized a proper callerid name and

number from a P-Asserted-Identity cause the header parsing logic was wrong. 
Changing the parsing functions to the sip header parsing APIs in 
reqresp_parser.h solves this problem.

Review: https://reviewboard.asterisk.org/r/1673
Reviewed by: wdoekes2 and Mark Michelson
........

Merged revisions 351396 from http://svn.asterisk.org/svn/asterisk/branches/1.8


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/10@351408 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_sip.c

@@ -15207,10 +15207,12 @@ static int get_pai(struct sip_pvt *p, struct sip_request *req)
 {
 	char pai[256];
 	char privacy[64];
-	char *cid_num = "";
-	char *cid_name = "";
+	char *cid_num = NULL;
+	char *cid_name = NULL;
+	char emptyname[1] = "";
 	int callingpres = AST_PRES_ALLOWED_USER_NUMBER_NOT_SCREENED;
-	char *start = NULL, *end = NULL, *uri = NULL;
+	char *uri = NULL;
+	int is_anonymous = 0, do_update = 1, no_name = 0;
 
 	ast_copy_string(pai, sip_get_header(req, "P-Asserted-Identity"), sizeof(pai));
 
@@ -15218,73 +15220,59 @@ static int get_pai(struct sip_pvt *p, struct sip_request *req)
 		return 0;
 	}
 
-	start = pai;
-	if (*start == '"') {
-		*start++ = '\0';
-		end = strchr(start, '"');
-		if (!end) {
-			return 0;
-		}
-		*end++ = '\0';
-		cid_name = start;
-		start = ast_skip_blanks(end);
+	/* use the reqresp_parser function get_name_and_number*/
+	if (get_name_and_number(pai, &cid_name, &cid_num)) {
+		return 0;
 	}
 
-	if (*start != '<')
-		return 0;
-	/* At this point, 'start' points to the URI in brackets.
-	 * We need a copy so that our comparison to the anonymous
-	 * URI is valid.
-	 */
-	uri = ast_strdupa(start);
-	*start++ = '\0';
-	end = strchr(start, '@');
-	if (!end) {
-		return 0;
+	if (global_shrinkcallerid && ast_is_shrinkable_phonenumber(cid_num)) {
+		ast_shrink_phone_number(cid_num);
 	}
-	*end++ = '\0';
+
+	uri = get_in_brackets(pai);
 	if (!strncasecmp(uri, "sip:anonymous@anonymous.invalid", 31)) {
 		callingpres = AST_PRES_PROHIB_USER_NUMBER_NOT_SCREENED;
 		/*XXX Assume no change in cid_num. Perhaps it should be
 		 * blanked?
 		 */
+		ast_free(cid_num);
+		is_anonymous = 1;
 		cid_num = (char *)p->cid_num;
-	} else if (!strncasecmp(start, "sip:", 4)) {
-		cid_num = start + 4;
-		if (global_shrinkcallerid && ast_is_shrinkable_phonenumber(cid_num))
-			ast_shrink_phone_number(cid_num);
-		start = end;
-
-		end = strchr(start, '>');
-		if (!end) {
-			return 0;
-		}
-		*end = '\0';
-	} else {
-		return 0;
 	}
 
 	ast_copy_string(privacy, sip_get_header(req, "Privacy"), sizeof(privacy));
 	if (!ast_strlen_zero(privacy) && strncmp(privacy, "id", 2)) {
 		callingpres = AST_PRES_PROHIB_USER_NUMBER_NOT_SCREENED;
 	}
-
+	if (!cid_name) {
+		no_name = 1;
+		cid_name = (char *)emptyname;
+	}	
 	/* Only return true if the supplied caller id is different */
 	if (!strcasecmp(p->cid_num, cid_num) && !strcasecmp(p->cid_name, cid_name) && p->callingpres == callingpres) {
-		return 0;
-	}
+		do_update = 0;
+	} else {
 
-	ast_string_field_set(p, cid_num, cid_num);
-	ast_string_field_set(p, cid_name, cid_name);
-	p->callingpres = callingpres;
+		ast_string_field_set(p, cid_num, cid_num);
+		ast_string_field_set(p, cid_name, cid_name);
+		p->callingpres = callingpres;
 
-	if (p->owner) {
-		ast_set_callerid(p->owner, cid_num, cid_name, NULL);
-		p->owner->caller.id.name.presentation = callingpres;
-		p->owner->caller.id.number.presentation = callingpres;
+		if (p->owner) {
+			ast_set_callerid(p->owner, cid_num, cid_name, NULL);
+			p->owner->caller.id.name.presentation = callingpres;
+			p->owner->caller.id.number.presentation = callingpres;
+		}
 	}
 
-	return 1;
+	/* get_name_and_number allocates memory for cid_num and cid_name so we have to free it */
+	if (!is_anonymous) {
+		ast_free(cid_num);
+	}
+	if (!no_name) {
+		ast_free(cid_name);
+	}
+
+	return do_update;
 }
 
 /*! \brief Get name, number and presentation from remote party id header,