Implement the '!' negation element to negate codecs directly in the allow keyword.

This permits the list of codecs to be specified in one configuration line,
instead of two or more, generally with the aim of either allowing all codecs
with the exception of a few or disallowing most but permitting a few.

Review: https://reviewboard.asterisk.org/r/1411/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@334574 65c4cc65-6c06-0410-ace0-fbb531ad65f3

CHANGES

@@ -24,6 +24,13 @@ Chan_local changes
  * Added a manager event "LocalBridge" for local channel call bridges between
    the two pseudo-channels created.
 
+Codec changes
+-------------
+ * Codec lists may now be modified by the '!' character, to allow succinct
+   specification of a list of codecs allowed and disallowed, without the
+   requirement to use two different keywords.  For example, to specify all
+   codecs except g729 and g723, one need only specify allow=all,!g729,!g723.
+
 ------------------------------------------------------------------------------
 --- Functionality changes from Asterisk 1.8 to Asterisk 10 -------------------
 ------------------------------------------------------------------------------

configs/sip.conf.sample

@@ -1216,10 +1216,14 @@ srvlookup=yes                   ; Enable DNS SRV lookups on outbound calls
         allow=gsm
         allow=g723
         allow=ulaw
+        ; Or, more simply:
+        ;allow=!all,ilbc,g729,gsm,g723,ulaw
 
 [ulaw-phone](!)                   ; and another one for ulaw-only
         disallow=all
         allow=ulaw
+        ; Again, more simply:
+        ;allow=!all,ulaw
 
 ; and finally instantiate a few phones
 ;

contrib/realtime/mysql/iaxfriends.sql

@@ -37,8 +37,7 @@ CREATE TABLE `iaxfriends` (
   `transfer` varchar(10) NULL, -- mediaonly/yes/no
   `jitterbuffer` varchar(3) NULL, -- yes/no
   `forcejitterbuffer` varchar(3) NULL, -- yes/no
-  `disallow` varchar(40) NULL, -- all/{list-of-codecs}
-  `allow` varchar(40) NULL, -- all/{list-of-codecs}
+  `allow` varchar(200) NULL, -- all/{list-of-codecs}
   `codecpriority` varchar(40) NULL, 
   `qualify` varchar(10) NULL, -- yes/no/{number of milliseconds}
   `qualifysmoothing` varchar(10) NULL, -- yes/no

contrib/realtime/mysql/sipfriends.sql

@@ -28,8 +28,7 @@ CREATE TABLE IF NOT EXISTS `sipfriends` (
       `callgroup` varchar(40) DEFAULT NULL,
       `pickupgroup` varchar(40) DEFAULT NULL,
       `language` varchar(40) DEFAULT NULL,
-      `allow` varchar(40) DEFAULT NULL,
-      `disallow` varchar(40) DEFAULT NULL,
+      `allow` varchar(200) DEFAULT NULL,
       `insecure` varchar(40) DEFAULT NULL,
       `trustrpid` enum('yes','no') DEFAULT NULL,
       `progressinband` enum('yes','no','never') DEFAULT NULL,

contrib/realtime/postgresql/realtime.sql

@@ -61,8 +61,7 @@ rtpholdtimeout character varying(3),
 secret character varying(80),
 "type" character varying DEFAULT 'friend' NOT NULL,
 username character varying(80) DEFAULT '' NOT NULL,
-disallow character varying(100) DEFAULT 'all',
-allow character varying(100) DEFAULT 'g729;ilbc;gsm;ulaw;alaw',
+allow character varying(200) DEFAULT '!all,g729,ilbc,gsm,ulaw,alaw',
 musiconhold character varying(100),
 regseconds bigint DEFAULT 0::bigint NOT NULL,
 ipaddr character varying(40) DEFAULT '' NOT NULL,

main/frame.c

@@ -730,13 +730,18 @@ void ast_frame_dump(const char *name, struct ast_frame *f, char *prefix)
 
 int ast_parse_allow_disallow(struct ast_codec_pref *pref, struct ast_format_cap *cap, const char *list, int allowing) 
 {
-	int errors = 0, framems = 0, all = 0;
+	int errors = 0, framems = 0, all = 0, iter_allowing;
 	char *parse = NULL, *this = NULL, *psize = NULL;
 	struct ast_format format;
 
 	parse = ast_strdupa(list);
 	while ((this = strsep(&parse, ","))) {
+		iter_allowing = allowing;
 		framems = 0;
+		if (*this == '!') {
+			this++;
+			iter_allowing = !allowing;
+		}
 		if ((psize = strrchr(this, ':'))) {
 			*psize++ = '\0';
 			ast_debug(1, "Packetization for codec: %s is %s\n", this, psize);
@@ -750,13 +755,13 @@ int ast_parse_allow_disallow(struct ast_codec_pref *pref, struct ast_format_cap
 		all = strcasecmp(this, "all") ? 0 : 1;
 
 		if (!all && !ast_getformatbyname(this, &format)) {
-			ast_log(LOG_WARNING, "Cannot %s unknown format '%s'\n", allowing ? "allow" : "disallow", this);
+			ast_log(LOG_WARNING, "Cannot %s unknown format '%s'\n", iter_allowing ? "allow" : "disallow", this);
 			errors++;
 			continue;
 		}
 
 		if (cap) {
-			if (allowing) {
+			if (iter_allowing) {
 				if (all) {
 					ast_format_cap_add_all(cap);
 				} else {
@@ -773,13 +778,13 @@ int ast_parse_allow_disallow(struct ast_codec_pref *pref, struct ast_format_cap
 
 		if (pref) {
 			if (!all) {
-				if (allowing) {
+				if (iter_allowing) {
 					ast_codec_pref_append(pref, &format);
 					ast_codec_pref_setsize(pref, &format, framems);
 				} else {
 					ast_codec_pref_remove(pref, &format);
 				}
-			} else if (!allowing) {
+			} else if (!iter_allowing) {
 				memset(pref, 0, sizeof(*pref));
 			}
 		}