chan_dahdi: remove by_name support

Support for referring to DAHDI channels by logical names was added in
(FIXME: when? Asterisk 11? 1.8?) and was intended to be part of support
of refering to channels by name.

While technically usable, it has never been properly supported in
dahdi-tools, as using it would require many changes at the Asterisk
level. Instead logical mapping was added at the kernel level.

Thus it seems that refering to DAHDI channels by name is not really used
by anyone, and therefore should probably be removed.

Change-Id: I7d50bbfd9d957586f5cd06570244ef87bd54b485

UPGRADE.txt

@@ -32,3 +32,12 @@ Queue:
    added via the CLI command "queue add" or the AMI action "QueueAdd") now have
    their ringinuse value updated to the value of the queue. Previously, the
    ringinuse value for dynamic members was not updated on reload.
+
+Channel Drivers:
+
+chan_dahdi:
+ - Support for specifying a DAHDI channel using a path under /dev/dahdi
+   ("by name") has been removed. It was never used. Instead you should
+   use kernel-level channel number allocation using span assignments.
+   See the documentation of dahdi-linux and dahdi-tools.
+

channels/chan_dahdi.c

@@ -11977,38 +11977,6 @@ static int sigtype_to_signalling(int sigtype)
 	return sigtype;
 }
 
-/*!
- * \internal
- * \brief Get file name and channel number from (subdir,number)
- *
- * \param subdir name of the subdirectory under /dev/dahdi/
- * \param channel name of device file under /dev/dahdi/<subdir>/
- * \param path buffer to put file name in
- * \param pathlen maximal length of path
- *
- * \retval minor number of dahdi channel.
- * \retval -errno on error.
- */
-static int device2chan(const char *subdir, int channel, char *path, int pathlen)
-{
-	struct stat	stbuf;
-	int		num;
-
-	snprintf(path, pathlen, "/dev/dahdi/%s/%d", subdir, channel);
-	if (stat(path, &stbuf) < 0) {
-		ast_log(LOG_ERROR, "stat(%s) failed: %s\n", path, strerror(errno));
-		return -errno;
-	}
-	if (!S_ISCHR(stbuf.st_mode)) {
-		ast_log(LOG_ERROR, "%s: Not a character device file\n", path);
-		return -EINVAL;
-	}
-	num = minor(stbuf.st_rdev);
-	ast_debug(1, "%s -> %d\n", path, num);
-	return num;
-
-}
-
 /*!
  * \internal
  * \brief Initialize/create a channel interface.
@@ -17426,33 +17394,9 @@ static int unload_module(void)
 	return __unload_module();
 }
 
-static void string_replace(char *str, int char1, int char2)
-{
-	for (; *str; str++) {
-		if (*str == char1) {
-			*str = char2;
-		}
-	}
-}
-
-static char *parse_spanchan(char *chanstr, char **subdir)
-{
-	char *p;
-
-	if ((p = strrchr(chanstr, '!')) == NULL) {
-		*subdir = NULL;
-		return chanstr;
-	}
-	*p++ = '\0';
-	string_replace(chanstr, '!', '/');
-	*subdir = chanstr;
-	return p;
-}
-
 static int build_channels(struct dahdi_chan_conf *conf, const char *value, int reload, int lineno)
 {
 	char *c, *chan;
-	char *subdir;
 	int x, start, finish;
 	struct dahdi_pvt *tmp;
 
@@ -17462,7 +17406,6 @@ static int build_channels(struct dahdi_chan_conf *conf, const char *value, int r
 	}
 
 	c = ast_strdupa(value);
-	c = parse_spanchan(c, &subdir);
 
 	while ((chan = strsep(&c, ","))) {
 		if (sscanf(chan, "%30d-%30d", &start, &finish) == 2) {
@@ -17484,39 +17427,22 @@ static int build_channels(struct dahdi_chan_conf *conf, const char *value, int r
 		}
 
 		for (x = start; x <= finish; x++) {
-			char fn[PATH_MAX];
-			int real_channel = x;
-
-			if (!ast_strlen_zero(subdir)) {
-				real_channel = device2chan(subdir, x, fn, sizeof(fn));
-				if (real_channel < 0) {
-					if (conf->ignore_failed_channels) {
-						ast_log(LOG_WARNING, "Failed configuring %s!%d, (got %d). But moving on to others.\n",
-								subdir, x, real_channel);
-						continue;
-					} else {
-						ast_log(LOG_ERROR, "Failed configuring %s!%d, (got %d).\n",
-								subdir, x, real_channel);
-						return -1;
-					}
-				}
-			}
 			if (conf->wanted_channels_start &&
-				(real_channel < conf->wanted_channels_start ||
-				 real_channel > conf->wanted_channels_end)
+				(x < conf->wanted_channels_start ||
+				 x > conf->wanted_channels_end)
 			   ) {
 				continue;
 			}
-			tmp = mkintf(real_channel, conf, reload);
+			tmp = mkintf(x, conf, reload);
 
 			if (tmp) {
-				ast_verb(3, "%s channel %d, %s signalling\n", reload ? "Reconfigured" : "Registered", real_channel, sig2str(tmp->sig));
+				ast_verb(3, "%s channel %d, %s signalling\n", reload ? "Reconfigured" : "Registered", x, sig2str(tmp->sig));
 			} else {
 				ast_log(LOG_ERROR, "Unable to %s channel '%s'\n",
 						(reload == 1) ? "reconfigure" : "register", value);
 				return -1;
 			}
-			if (real_channel == CHAN_PSEUDO) {
+			if (x == CHAN_PSEUDO) {
 				has_pseudo = 1;
 			}
 		}

configs/samples/chan_dahdi.conf.sample

@@ -1330,24 +1330,6 @@ pickupgroup=1
 ; signalling = pri_cpe
 ; group = 2
 ; channel => 1-23
-;
-; Alternatively, the number of the channel may be replaced with a relative
-; path to a device file under /dev/dahdi . The final element of that file
-; must be a number, though. The directory separator is '!', as we can't
-; use '/' in a dial string. So if we have
-;
-;   /dev/dahdi/span-name/pstn/00/1
-;   /dev/dahdi/span-name/pstn/00/2
-;   /dev/dahdi/span-name/pstn/00/3
-;   /dev/dahdi/span-name/pstn/00/4
-;
-; we could use:
-;channel => span-name!pstn!00!1-4
-;
-; or:
-;channel => span-name!pstn!00!1,2,3,4
-;
-; See also ignore_failed_channels above.
 
 ;  Used for distinctive ring support for x100p.
 ;  You can see the dringX patterns is to set any one of the dringXcontext fields