Remove AST_PBX_KEEPALIVE usage from res_agi.
authorRussell Bryant <russell@russellbryant.com>
Mon, 22 Dec 2008 14:16:54 +0000 (14:16 +0000)
committerRussell Bryant <russell@russellbryant.com>
Mon, 22 Dec 2008 14:16:54 +0000 (14:16 +0000)
This patch removes the usage of AST_PBX_KEEPALIVE from res_agi.  The only usage
was for the AGI command, "asyncagi break".  This patch removes this feature.
Normally, a feature would not be removed like this.  However, this code is
broken and usage of it will result in a memory leak.

Usage of this feature will make the AGI code return a result of
AST_PBX_KEEPALIVE.  The PBX handler assumes that another thread has assumed
ownership of the channel.  The channel thread will exit without destroying the
channel.  Unfortunately, _no_ thread has ownership of the channel at this
point.  There are a couple of serious problems here:

1) The only way to recover the caller is to issue a channel redirect.  This
   will work, but this will be done with a masquerade, and the old ast_channel
   structure will be lost.

2) Until the channel redirect happens, there is no code servicing the channel.
   That means nothing is reading audio or handling events coming from the
   channel.  This is very bad.

The recommended way to get this same "break" functionality is to issue the
redirect while the channel is still being handled by the AGI code.  That way,
there will be no memory leak, and there will be no period of time that the
channel is not being serviced.

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@166258 65c4cc65-6c06-0410-ace0-fbb531ad65f3

res/res_agi.c

index bda3e79..151ac1a 100644 (file)
@@ -687,7 +687,7 @@ static enum agi_result launch_asyncagi(struct ast_channel *chan, char *argv[], i
                        /* OK, we have a command, let's call the
                           command handler. */
                        res = agi_handle_command(chan, &async_agi, cmd->cmd_buffer, 0);
-                       if ((res < 0) || (res == AST_PBX_KEEPALIVE)) {
+                       if (res < 0) {
                                free_agi_cmd(cmd);
                                break;
                        }
@@ -2229,12 +2229,6 @@ static int handle_speechrecognize(struct ast_channel *chan, AGI *agi, int argc,
        return RESULT_SUCCESS;
 }
 
-static int handle_asyncagi_break(struct ast_channel *chan, AGI *agi, int argc, char *argv[])
-{
-       ast_agi_send(agi->fd, chan, "200 result=0\n");
-       return AST_PBX_KEEPALIVE;
-}
-
 static char usage_verbose[] =
 " Usage: VERBOSE <message> <level>\n"
 "      Sends <message> to the console via verbose message system.\n"
@@ -2395,10 +2389,6 @@ static char usage_autohangup[] =
 " future.  Of course it can be hungup before then as well. Setting to 0 will\n"
 " cause the autohangup feature to be disabled on this channel.\n";
 
-static char usage_break_aagi[] =
-" Usage: ASYNCAGI BREAK\n"
-"      Break the Async AGI loop.\n";
-
 static char usage_speechcreate[] =
 " Usage: SPEECH CREATE <engine>\n"
 "       Create a speech object to be used by the other Speech AGI commands.\n";
@@ -2480,7 +2470,6 @@ static struct agi_command commands[] = {
        { { "speech", "activate", "grammar", NULL }, handle_speechactivategrammar, "Activates a grammar", usage_speechactivategrammar, 0 },
        { { "speech", "deactivate", "grammar", NULL }, handle_speechdeactivategrammar, "Deactivates a grammar", usage_speechdeactivategrammar, 0 },
        { { "speech", "recognize", NULL }, handle_speechrecognize, "Recognizes speech", usage_speechrecognize, 0 },
-       { { "asyncagi", "break", NULL }, handle_asyncagi_break, "Break AsyncAGI loop", usage_break_aagi, 0 },
 };
 
 static AST_RWLIST_HEAD_STATIC(agi_commands, agi_command);
@@ -2751,7 +2740,6 @@ static int agi_handle_command(struct ast_channel *chan, AGI *agi, char *buf, int
                        ast_module_unref(c->mod);
                switch (res) {
                case RESULT_SHOWUSAGE: ami_res = "Usage"; resultcode = 520; break;
-               case AST_PBX_KEEPALIVE: ami_res = "KeepAlive"; resultcode = 210; break;
                case RESULT_FAILURE: ami_res = "Failure"; resultcode = -1; break;
                case RESULT_SUCCESS: ami_res = "Success"; resultcode = 200; break;
                }
@@ -2768,10 +2756,6 @@ static int agi_handle_command(struct ast_channel *chan, AGI *agi, char *buf, int
                        ast_agi_send(agi->fd, chan, "%s", c->usage);
                        ast_agi_send(agi->fd, chan, "520 End of proper usage.\n");
                        break;
-               case AST_PBX_KEEPALIVE:
-                       /* We've been asked to keep alive, so do so */
-                       return AST_PBX_KEEPALIVE;
-                       break;
                case RESULT_FAILURE:
                        /* They've already given the failure.  We've been hung up on so handle this
                           appropriately */
@@ -2876,8 +2860,9 @@ static enum agi_result run_agi(struct ast_channel *chan, char *request, AGI *agi
 
                        if (!buf[0]) {
                                /* Program terminated */
-                               if (returnstatus && returnstatus != AST_PBX_KEEPALIVE)
+                               if (returnstatus) {
                                        returnstatus = -1;
+                               }
                                ast_verb(3, "<%s>AGI Script %s completed, returning %d\n", chan->name, request, returnstatus);
                                if (pid > 0)
                                        waitpid(pid, status, 0);
@@ -2899,7 +2884,7 @@ static enum agi_result run_agi(struct ast_channel *chan, char *request, AGI *agi
                                ast_verbose("<%s>AGI Rx << %s\n", chan->name, buf);
                        returnstatus |= agi_handle_command(chan, agi, buf, dead);
                        /* If the handle_command returns -1, we need to stop */
-                       if ((returnstatus < 0) || (returnstatus == AST_PBX_KEEPALIVE)) {
+                       if (returnstatus < 0) {
                                needhup = 1;
                                continue;
                        }