app_dial.c: Simplify dialplan using Dial.

Dialplan has to be careful about passing an empty destination list or
empty positions in the list.  As a result, dialplan has to check for
these conditions before using Dial.  Simplify dialplan by making Dial
handle these conditions gracefully.

* Made tolerate empty positions in the dialed device list.

* Reduced some message log levels from notice to verbose.

ASTERISK-28638

Change-Id: I6edc731aff451f8bdfaee5498078dd18c3a11ab9

diff --git a/apps/app_dial.c b/apps/app_dial.c
index 4adfc47ecf3ef7e968f733dccecd66f5e57bac76..2744868201d94858305cc38cad9bf8ac9a89d9d5 100644 (file)
--- a/apps/app_dial.c
+++ b/apps/app_dial.c
@@ -74,7 +74,7 @@
                        Attempt to connect to another device or endpoint and bridge the call.
                </synopsis>
                <syntax>
-                       <parameter name="Technology/Resource" required="true" argsep="&amp;">
+                       <parameter name="Technology/Resource" required="false" argsep="&amp;">
                                <argument name="Technology/Resource" required="true">
                                        <para>Specification of the device(s) to dial.  These must be in the format of
                                        <literal>Technology/Resource</literal>, where <replaceable>Technology</replaceable>
@@ -1003,7 +1003,8 @@ static void do_forward(struct chanlist *o, struct cause_args *num,
                         * any Dial operations that happen later won't record CC interfaces.
                         */
                        ast_ignore_cc(o->chan);
-                       ast_log(LOG_NOTICE, "Not accepting call completion offers from call-forward recipient %s\n", ast_channel_name(o->chan));
+                       ast_verb(3, "Not accepting call completion offers from call-forward recipient %s\n",
+                               ast_channel_name(o->chan));
                } else
                        ast_log(LOG_NOTICE,
                                "Forwarding failed to create channel to dial '%s/%s' (cause = %d)\n",
@@ -2003,7 +2004,7 @@ static int do_privacy(struct ast_channel *chan, struct ast_channel *peer,
                /* well, there seems basically two choices. Just patch the caller thru immediately,
                          or,... put 'em thru to voicemail. */
                /* since the callee may have hung up, let's do the voicemail thing, no database decision */
-               ast_log(LOG_NOTICE, "privacy: no valid response from the callee. Sending the caller to voicemail, the callee isn't responding\n");
+               ast_verb(3, "privacy: no valid response from the callee. Sending the caller to voicemail, the callee isn't responding\n");
                /* XXX should we set status to DENY ? */
                /* XXX what about the privacy flags ? */
                break;
@@ -2294,12 +2295,6 @@ static int dial_exec_full(struct ast_channel *chan, const char *data, struct ast
                return -1;
        }
 
-       if (ast_strlen_zero(data)) {
-               ast_log(LOG_WARNING, "Dial requires an argument (technology/resource)\n");
-               pbx_builtin_setvar_helper(chan, "DIALSTATUS", pa.status);
-               return -1;
-       }
-
        if (ast_check_hangup_locked(chan)) {
                /*
                 * Caller hung up before we could dial.  If dial is executed
@@ -2318,7 +2313,7 @@ static int dial_exec_full(struct ast_channel *chan, const char *data, struct ast
                return -1;
        }
 
-       parse = ast_strdupa(data);
+       parse = ast_strdupa(data ?: "");
 
        AST_STANDARD_APP_ARGS(args, parse);
 
@@ -2328,12 +2323,6 @@ static int dial_exec_full(struct ast_channel *chan, const char *data, struct ast
                goto done;
        }
 
-       if (ast_strlen_zero(args.peers)) {
-               ast_log(LOG_WARNING, "Dial requires an argument (technology/resource)\n");
-               pbx_builtin_setvar_helper(chan, "DIALSTATUS", pa.status);
-               goto done;
-       }
-
        if (ast_cc_call_init(chan, &ignore_cc)) {
                goto done;
        }
@@ -2359,7 +2348,7 @@ static int dial_exec_full(struct ast_channel *chan, const char *data, struct ast
        if (ast_test_flag64(&opts, OPT_DURATION_STOP) && !ast_strlen_zero(opt_args[OPT_ARG_DURATION_STOP])) {
                calldurationlimit.tv_sec = atoi(opt_args[OPT_ARG_DURATION_STOP]);
                if (!calldurationlimit.tv_sec) {
-                       ast_log(LOG_WARNING, "Dial does not accept S(%s), hanging up.\n", opt_args[OPT_ARG_DURATION_STOP]);
+                       ast_log(LOG_WARNING, "Dial does not accept S(%s)\n", opt_args[OPT_ARG_DURATION_STOP]);
                        pbx_builtin_setvar_helper(chan, "DIALSTATUS", pa.status);
                        goto done;
                }
@@ -2506,15 +2495,24 @@ static int dial_exec_full(struct ast_channel *chan, const char *data, struct ast
 
        /* loop through the list of dial destinations */
        rest = args.peers;
-       while ((cur = strsep(&rest, "&")) ) {
+       while ((cur = strsep(&rest, "&"))) {
                struct ast_channel *tc; /* channel for this destination */
-               /* Get a technology/resource pair */
-               char *number = cur;
-               char *tech = strsep(&number, "/");
+               char *number;
+               char *tech;
                size_t tech_len;
                size_t number_len;
                struct ast_stream_topology *topology;
 
+               cur = ast_strip(cur);
+               if (ast_strlen_zero(cur)) {
+                       /* No tech/resource in this position. */
+                       continue;
+               }
+
+               /* Get a technology/resource pair */
+               number = cur;
+               tech = strsep(&number, "/");
+
                num_dialed++;
                if (ast_strlen_zero(number)) {
                        ast_log(LOG_WARNING, "Dial argument takes format (technology/resource)\n");
@@ -2713,6 +2711,17 @@ static int dial_exec_full(struct ast_channel *chan, const char *data, struct ast
                AST_LIST_INSERT_TAIL(&out_chans, tmp, node);
        }
 
+       if (AST_LIST_EMPTY(&out_chans)) {
+               ast_verb(3, "No devices or endpoints to dial (technology/resource)\n");
+               if (continue_exec) {
+                       /* There is no point in having RetryDial try again */
+                       *continue_exec = 1;
+               }
+               strcpy(pa.status, "CHANUNAVAIL");
+               res = 0;
+               goto out;
+       }
+
        /*
         * PREDIAL: Run gosub on all of the callee channels
         *

diff --git a/doc/CHANGES-staging/app_dial_empty_dial_list.txt b/doc/CHANGES-staging/app_dial_empty_dial_list.txt
new file mode 100644 (file)
index 0000000..dc68ee6
--- /dev/null
+++ b/doc/CHANGES-staging/app_dial_empty_dial_list.txt
@@ -0,0 +1,6 @@
+Subject: app_dial
+
+The Dial application now tolerates empty positions in the supplied
+destination list.  Dialplan can now be simplified by not having to check
+for empty positions in the destination list.  If there are no endpoints to
+dial then DIALSTATUS is set to CHANUNAVAIL.