features: Add no answer option to Bridge.

Adds the n "no answer" option to the Bridge application
so that answer supervision can not automatically
be provided when Bridge is executed.

Additionally, a mechanism (dialplan variable)
is added to prevent bridge targets (typically the
target of a masquerade) from answering the channel
when they enter the bridge.

ASTERISK-30223 #close

Change-Id: I76f73fcd8e403bcd18f2abb40c658f537ac1ba6d

diff --git a/doc/CHANGES-staging/features_bridge_noanswer.txt b/doc/CHANGES-staging/features_bridge_noanswer.txt
new file mode 100644 (file)
index 0000000..7399ad1
--- /dev/null
+++ b/doc/CHANGES-staging/features_bridge_noanswer.txt
@@ -0,0 +1,5 @@
+Subject: features
+
+The Bridge application now has the n "no answer" option
+that can be used to prevent the channel from being
+automatically answered prior to bridging.

diff --git a/main/features.c b/main/features.c
index db584b590d8d52a315b26eb2046567082f15cccf..39d8aabde5c781ebb9e91161796d966a6ad39b15 100644 (file)
--- a/main/features.c
+++ b/main/features.c
@@ -164,6 +164,12 @@
                                                        </variable>
                                                </variablelist>
                                        </option>
+                                       <option name="n">
+                                               <para>Do not answer the channel automatically before bridging.</para>
+                                               <para>Additionally, to prevent a bridged channel (the target of the Bridge application)
+                                               from answering, the <literal>BRIDGE_NOANSWER</literal> variable can be set to inhibit
+                                               answering.</para>
+                                       </option>
                                        <option name="S(x)">
                                                <para>Hang up the call after <replaceable>x</replaceable> seconds *after* the called party has answered the call.</para>
                                        </option>
@@ -525,7 +531,7 @@ static void bridge_failed_peer_goto(struct ast_channel *chan, struct ast_channel
 }
 
 static int pre_bridge_setup(struct ast_channel *chan, struct ast_channel *peer, struct ast_bridge_config *config,
-               struct ast_bridge_features *chan_features, struct ast_bridge_features *peer_features)
+               struct ast_bridge_features *chan_features, struct ast_bridge_features *peer_features, int noanswer)
 {
        int res;
        SCOPE_TRACE(1, "%s Peer: %s\n", ast_channel_name(chan), ast_channel_name(peer));
@@ -553,7 +559,10 @@ static int pre_bridge_setup(struct ast_channel *chan, struct ast_channel *peer,
 
        res = 0;
 
-       if (ast_channel_state(chan) != AST_STATE_UP) {
+       if (noanswer) {
+               ast_debug(1, "Skipping answer on %s due to no answer directive\n", ast_channel_name(chan));
+       } else if (ast_channel_state(chan) != AST_STATE_UP) {
+               ast_debug(1, "Answering channel for bridge: %s\n", ast_channel_name(chan));
                res = ast_raw_answer_with_stream_topology(chan, config->answer_topology);
                if (res != 0) {
                        return -1;
@@ -627,6 +636,8 @@ int ast_bridge_call_with_flags(struct ast_channel *chan, struct ast_channel *pee
        struct ast_bridge *bridge;
        struct ast_bridge_features chan_features;
        struct ast_bridge_features *peer_features;
+       const char *value;
+       int noanswer;
        SCOPE_TRACE(1, "%s Peer: %s\n", ast_channel_name(chan), ast_channel_name(peer));
 
        /* Setup features. */
@@ -639,7 +650,12 @@ int ast_bridge_call_with_flags(struct ast_channel *chan, struct ast_channel *pee
                return -1;
        }
 
-       if (pre_bridge_setup(chan, peer, config, &chan_features, peer_features)) {
+       ast_channel_lock(chan);
+       value = pbx_builtin_getvar_helper(chan, "BRIDGE_NOANSWER");
+       noanswer = !ast_strlen_zero(value) ? 1 : 0;
+       ast_channel_unlock(chan);
+
+       if (pre_bridge_setup(chan, peer, config, &chan_features, peer_features, noanswer)) {
                ast_bridge_features_destroy(peer_features);
                ast_bridge_features_cleanup(&chan_features);
                bridge_failed_peer_goto(chan, peer);
@@ -848,6 +864,7 @@ enum {
        OPT_CALLER_PARK = (1 << 10),
        OPT_CALLEE_KILL = (1 << 11),
        OPT_CALLEE_GO_ON = (1 << 12),
+       OPT_NOANSWER = (1 << 13),
 };
 
 enum {
@@ -866,6 +883,7 @@ AST_APP_OPTIONS(bridge_exec_options, BEGIN_OPTIONS
        AST_APP_OPTION('k', OPT_CALLEE_PARK),
        AST_APP_OPTION('K', OPT_CALLER_PARK),
        AST_APP_OPTION_ARG('L', OPT_DURATION_LIMIT, OPT_ARG_DURATION_LIMIT),
+       AST_APP_OPTION('n', OPT_NOANSWER),
        AST_APP_OPTION_ARG('S', OPT_DURATION_STOP, OPT_ARG_DURATION_STOP),
        AST_APP_OPTION('t', OPT_CALLEE_TRANSFER),
        AST_APP_OPTION('T', OPT_CALLER_TRANSFER),
@@ -1012,6 +1030,7 @@ static int bridge_exec(struct ast_channel *chan, const char *data)
        struct ast_bridge_features *peer_features;
        struct ast_bridge *bridge;
        struct ast_features_xfer_config *xfer_cfg;
+       int noanswer;
 
        AST_DECLARE_APP_ARGS(args,
                AST_APP_ARG(dest_chan);
@@ -1066,6 +1085,7 @@ static int bridge_exec(struct ast_channel *chan, const char *data)
                ast_set_flag(&(bconfig.features_callee), AST_FEATURE_PARKCALL);
        if (ast_test_flag(&opts, OPT_CALLER_PARK))
                ast_set_flag(&(bconfig.features_caller), AST_FEATURE_PARKCALL);
+       noanswer = ast_test_flag(&opts, OPT_NOANSWER);
 
        /* Setup after bridge goto location. */
        if (ast_test_flag(&opts, OPT_CALLEE_GO_ON)) {
@@ -1096,7 +1116,7 @@ static int bridge_exec(struct ast_channel *chan, const char *data)
                goto done;
        }
 
-       if (pre_bridge_setup(chan, current_dest_chan, &bconfig, &chan_features, peer_features)) {
+       if (pre_bridge_setup(chan, current_dest_chan, &bconfig, &chan_features, peer_features, noanswer)) {
                ast_bridge_features_destroy(peer_features);
                ast_bridge_features_cleanup(&chan_features);
                goto done;