app_stack.c File Reference

Stack applications Gosub, Return, etc. More...

#include "asterisk.h"
#include "asterisk/pbx.h"
#include "asterisk/module.h"
#include "asterisk/app.h"
#include "asterisk/manager.h"
#include "asterisk/channel.h"
#include "asterisk/agi.h"

Include dependency graph for app_stack.c:

Go to the source code of this file.

Data Structures
struct	gosub_stack_frame
Defines
#define	ASTERISK_AGI_OPTIONAL
Functions
static void	__reg_module (void)
static void	__unreg_module (void)
static int	frame_set_var (struct ast_channel *chan, struct gosub_stack_frame *frame, const char *var, const char *value)
static struct gosub_stack_frame *	gosub_allocate_frame (const char *context, const char *extension, int priority, unsigned char arguments)
static int	gosub_exec (struct ast_channel *chan, void *data)
static void	gosub_free (void *data)
static void	gosub_release_frame (struct ast_channel *chan, struct gosub_stack_frame *frame)
static int	gosubif_exec (struct ast_channel *chan, void *data)
static int	handle_gosub (struct ast_channel *chan, AGI *agi, int argc, char **argv)
static int	load_module (void)
static int	local_read (struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t len)
static int	local_write (struct ast_channel *chan, const char *cmd, char *var, const char *value)
static int	pop_exec (struct ast_channel *chan, void *data)
static int	return_exec (struct ast_channel *chan, void *data)
static int	unload_module (void)
Variables
static struct ast_module_info	__mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_DEFAULT , .description = "Dialplan subroutines (Gosub, Return, etc)" , .key = "This paragraph is copyright (c) 2006 by Digium, Inc. \In order for your module to load, it must return this \key via a function called \"key\". Any code which \includes this paragraph must be licensed under the GNU \General Public License version 2 or later (at your \option). In addition to Digium's general reservations \of rights, Digium expressly reserves the right to \allow other parties to license this paragraph under \different terms. Any use of Digium, Inc. trademarks or \logos (including \"Asterisk\" or \"Digium\") without \express written permission of Digium, Inc. is prohibited.\n" , .buildopt_sum = "a9c98e5d177805051735cb5b0b16b0a0" , .load = load_module, .unload = unload_module, }
static const char *	app_gosub = "Gosub"
static const char *	app_gosubif = "GosubIf"
static const char *	app_pop = "StackPop"
static const char *	app_return = "Return"
static struct ast_module_info *	ast_module_info = &__mod_info
struct agi_command	gosub_agi_command
static const char *	gosub_descrip
static const char *	gosub_synopsis = "Jump to label, saving return address"
static const char *	gosubif_descrip
static const char *	gosubif_synopsis = "Conditionally jump to label, saving return address"
static struct ast_custom_function	local_function
static const char *	pop_descrip
static const char *	pop_synopsis = "Remove one address from gosub stack"
static const char *	return_descrip
static const char *	return_synopsis = "Return from gosub routine"
static struct ast_datastore_info	stack_info
static char	usage_gosub []

---

Detailed Description

Stack applications Gosub, Return, etc.

Author:

Tilghman Lesher <app_stack_v003@the-tilghman.com>

Definition in file app_stack.c.

---

Define Documentation

#define ASTERISK_AGI_OPTIONAL

Definition at line 43 of file app_stack.c.

---

Function Documentation

static void __reg_module

(

void

)

[static]

Definition at line 551 of file app_stack.c.

static void __unreg_module

(

void

)

[static]

Definition at line 551 of file app_stack.c.

static int frame_set_var	(	struct ast_channel *	chan,
		struct gosub_stack_frame *	frame,
		const char *	var,
		const char *	value
	)			[static]

Definition at line 91 of file app_stack.c.

References AST_LIST_INSERT_HEAD, AST_LIST_TRAVERSE, ast_var_assign(), ast_var_name(), EVENT_FLAG_DIALPLAN, manager_event, pbx_builtin_pushvar_helper(), and pbx_builtin_setvar_helper().

Referenced by gosub_exec(), and local_write().

{
   struct ast_var_t *variables;
   int found = 0;

   /* Does this variable already exist? */
   AST_LIST_TRAVERSE(&frame->varshead, variables, entries) {
      if (!strcmp(var, ast_var_name(variables))) {
         found = 1;
         break;
      }
   }

   if (!found) {
      variables = ast_var_assign(var, "");
      AST_LIST_INSERT_HEAD(&frame->varshead, variables, entries);
      pbx_builtin_pushvar_helper(chan, var, value);
   } else {
      pbx_builtin_setvar_helper(chan, var, value);
   }

   manager_event(EVENT_FLAG_DIALPLAN, "VarSet",
      "Channel: %s\r\n"
      "Variable: LOCAL(%s)\r\n"
      "Value: %s\r\n"
      "Uniqueid: %s\r\n",
      chan->name, var, value, chan->uniqueid);
   return 0;
}

static struct gosub_stack_frame* gosub_allocate_frame	(	const char *	context,
		const char *	extension,
		int	priority,
		unsigned char	arguments
	)			[static, read]

Definition at line 140 of file app_stack.c.

References ast_calloc, and AST_LIST_HEAD_INIT_NOLOCK.

Referenced by gosub_exec().

{
   struct gosub_stack_frame *new = NULL;
   int len_extension = strlen(extension), len_context = strlen(context);

   if ((new = ast_calloc(1, sizeof(*new) + 2 + len_extension + len_context))) {
      AST_LIST_HEAD_INIT_NOLOCK(&new->varshead);
      strcpy(new->extension, extension);
      new->context = new->extension + len_extension + 1;
      strcpy(new->context, context);
      new->priority = priority;
      new->arguments = arguments;
   }
   return new;
}

static int gosub_exec	(	struct ast_channel *	chan,
		void *	data
	)			[static]

Definition at line 227 of file app_stack.c.

References AST_APP_ARG, ast_calloc, ast_channel_datastore_add(), ast_channel_datastore_find(), ast_copy_string(), ast_datastore_alloc, ast_datastore_free(), ast_debug, AST_DECLARE_APP_ARGS, ast_exists_extension(), AST_FLAG_IN_AUTOLOOP, ast_free, AST_LIST_HEAD, AST_LIST_HEAD_INIT, AST_LIST_INSERT_HEAD, AST_LIST_LOCK, AST_LIST_UNLOCK, ast_log(), ast_parseable_goto(), AST_STANDARD_RAW_ARGS, ast_strdupa, ast_strlen_zero(), ast_test_flag, ast_channel::cid, ast_callerid::cid_num, gosub_stack_frame::context, ast_channel::context, ast_datastore::data, gosub_stack_frame::entries, ast_channel::exten, gosub_stack_frame::extension, frame_set_var(), gosub_allocate_frame(), LOG_ERROR, LOG_WARNING, gosub_stack_frame::priority, ast_channel::priority, and strsep().

Referenced by gosubif_exec(), and load_module().

{
   struct ast_datastore *stack_store = ast_channel_datastore_find(chan, &stack_info, NULL);
   AST_LIST_HEAD(, gosub_stack_frame) *oldlist;
   struct gosub_stack_frame *newframe;
   char argname[15], *tmp = ast_strdupa(data), *label, *endparen;
   int i;
   AST_DECLARE_APP_ARGS(args2,
      AST_APP_ARG(argval)[100];
   );

   if (ast_strlen_zero(data)) {
      ast_log(LOG_ERROR, "%s requires an argument: %s([[context,]exten,]priority[(arg1[,...][,argN])])\n", app_gosub, app_gosub);
      return -1;
   }

   if (!stack_store) {
      ast_debug(1, "Channel %s has no datastore, so we're allocating one.\n", chan->name);
      stack_store = ast_datastore_alloc(&stack_info, NULL);
      if (!stack_store) {
         ast_log(LOG_ERROR, "Unable to allocate new datastore.  Gosub will fail.\n");
         return -1;
      }

      oldlist = ast_calloc(1, sizeof(*oldlist));
      if (!oldlist) {
         ast_log(LOG_ERROR, "Unable to allocate datastore list head.  Gosub will fail.\n");
         ast_datastore_free(stack_store);
         return -1;
      }

      stack_store->data = oldlist;
      AST_LIST_HEAD_INIT(oldlist);
      ast_channel_datastore_add(chan, stack_store);
   }

   /* Separate the arguments from the label */
   /* NOTE:  you cannot use ast_app_separate_args for this, because '(' cannot be used as a delimiter. */
   label = strsep(&tmp, "(");
   if (tmp) {
      endparen = strrchr(tmp, ')');
      if (endparen)
         *endparen = '\0';
      else
         ast_log(LOG_WARNING, "Ouch.  No closing paren: '%s'?\n", (char *)data);
      AST_STANDARD_RAW_ARGS(args2, tmp);
   } else
      args2.argc = 0;

   /* Create the return address, but don't save it until we know that the Gosub destination exists */
   newframe = gosub_allocate_frame(chan->context, chan->exten, chan->priority + 1, args2.argc);

   if (!newframe) {
      return -1;
   }

   if (ast_parseable_goto(chan, label)) {
      ast_log(LOG_ERROR, "Gosub address is invalid: '%s'\n", (char *)data);
      ast_free(newframe);
      return -1;
   }

   if (!ast_exists_extension(chan, chan->context, chan->exten, ast_test_flag(chan, AST_FLAG_IN_AUTOLOOP) ? chan->priority + 1 : chan->priority, chan->cid.cid_num)) {
      ast_log(LOG_ERROR, "Attempt to reach a non-existent destination for gosub: (Context:%s, Extension:%s, Priority:%d)\n",
            chan->context, chan->exten, chan->priority);
      ast_copy_string(chan->context, newframe->context, sizeof(chan->context));
      ast_copy_string(chan->exten, newframe->extension, sizeof(chan->exten));
      chan->priority = newframe->priority;
      ast_free(newframe);
      return -1;
   }

   /* Now that we know for certain that we're going to a new location, set our arguments */
   for (i = 0; i < args2.argc; i++) {
      snprintf(argname, sizeof(argname), "ARG%d", i + 1);
      frame_set_var(chan, newframe, argname, args2.argval[i]);
      ast_debug(1, "Setting '%s' to '%s'\n", argname, args2.argval[i]);
   }

   /* And finally, save our return address */
   oldlist = stack_store->data;
   AST_LIST_LOCK(oldlist);
   AST_LIST_INSERT_HEAD(oldlist, newframe, entries);
   AST_LIST_UNLOCK(oldlist);

   return 0;
}

static void gosub_free

(

void *

data

)

[static]

Definition at line 156 of file app_stack.c.

References ast_free, AST_LIST_HEAD, AST_LIST_HEAD_DESTROY, AST_LIST_LOCK, AST_LIST_REMOVE_HEAD, AST_LIST_UNLOCK, gosub_stack_frame::entries, and gosub_release_frame().

{
   AST_LIST_HEAD(, gosub_stack_frame) *oldlist = data;
   struct gosub_stack_frame *oldframe;
   AST_LIST_LOCK(oldlist);
   while ((oldframe = AST_LIST_REMOVE_HEAD(oldlist, entries))) {
      gosub_release_frame(NULL, oldframe);
   }
   AST_LIST_UNLOCK(oldlist);
   AST_LIST_HEAD_DESTROY(oldlist);
   ast_free(oldlist);
}

static void gosub_release_frame	(	struct ast_channel *	chan,
		struct gosub_stack_frame *	frame
	)			[static]

Definition at line 121 of file app_stack.c.

References ast_free, AST_LIST_REMOVE_HEAD, ast_var_delete(), ast_var_name(), gosub_stack_frame::entries, pbx_builtin_setvar_helper(), and gosub_stack_frame::varshead.

Referenced by gosub_free(), pop_exec(), and return_exec().

{
   struct ast_var_t *vardata;

   /* If chan is not defined, then we're calling it as part of gosub_free,
    * and the channel variables will be deallocated anyway.  Otherwise, we're
    * just releasing a single frame, so we need to clean up the arguments for
    * that frame, so that we re-expose the variables from the previous frame
    * that were hidden by this one.
    */
   while ((vardata = AST_LIST_REMOVE_HEAD(&frame->varshead, entries))) {
      if (chan)
         pbx_builtin_setvar_helper(chan, ast_var_name(vardata), NULL);  
      ast_var_delete(vardata);
   }

   ast_free(frame);
}

static int gosubif_exec	(	struct ast_channel *	chan,
		void *	data
	)			[static]

Definition at line 315 of file app_stack.c.

References AST_APP_ARG, AST_DECLARE_APP_ARGS, ast_log(), AST_NONSTANDARD_RAW_ARGS, ast_strdupa, ast_strlen_zero(), cond, gosub_exec(), LOG_WARNING, and pbx_checkcondition().

Referenced by load_module().

{
   char *args;
   int res=0;
   AST_DECLARE_APP_ARGS(cond,
      AST_APP_ARG(ition);
      AST_APP_ARG(labels);
   );
   AST_DECLARE_APP_ARGS(label,
      AST_APP_ARG(iftrue);
      AST_APP_ARG(iffalse);
   );

   if (ast_strlen_zero(data)) {
      ast_log(LOG_WARNING, "GosubIf requires an argument: GosubIf(cond?label1(args):label2(args)\n");
      return 0;
   }

   args = ast_strdupa(data);
   AST_NONSTANDARD_RAW_ARGS(cond, args, '?');
   if (cond.argc != 2) {
      ast_log(LOG_WARNING, "GosubIf requires an argument: GosubIf(cond?label1(args):label2(args)\n");
      return 0;
   }

   AST_NONSTANDARD_RAW_ARGS(label, cond.labels, ':');

   if (pbx_checkcondition(cond.ition)) {
      if (!ast_strlen_zero(label.iftrue))
         res = gosub_exec(chan, label.iftrue);
   } else if (!ast_strlen_zero(label.iffalse)) {
      res = gosub_exec(chan, label.iffalse);
   }

   return res;
}

static int handle_gosub	(	struct ast_channel *	chan,
		AGI *	agi,
		int	argc,
		char **	argv
	)			[static]

Definition at line 415 of file app_stack.c.

References asprintf, ast_agi_send(), ast_channel_datastore_find(), ast_copy_string(), ast_debug, ast_exists_extension(), ast_findlabel_extension(), ast_free, AST_LIST_FIRST, AST_LIST_HEAD, ast_log(), AST_MAX_CONTEXT, AST_MAX_EXTENSION, ast_pbx_run_args(), ast_channel::cid, ast_callerid::cid_num, ast_channel::context, ast_datastore::data, errno, ast_channel::exten, agi_state::fd, gosub_stack_frame::is_agi, LOG_ERROR, LOG_WARNING, ast_pbx_args::no_hangup_chan, ast_channel::pbx, pbx_exec(), pbx_findapp(), ast_channel::priority, gosub_stack_frame::priority, RESULT_FAILURE, RESULT_SHOWUSAGE, and RESULT_SUCCESS.

{
   int old_priority, priority;
   char old_context[AST_MAX_CONTEXT], old_extension[AST_MAX_EXTENSION];
   struct ast_app *theapp;
   char *gosub_args;

   if (argc < 4 || argc > 5) {
      return RESULT_SHOWUSAGE;
   }

   ast_debug(1, "Gosub called with %d arguments: 0:%s 1:%s 2:%s 3:%s 4:%s\n", argc, argv[0], argv[1], argv[2], argv[3], argc == 5 ? argv[4] : "");

   if (sscanf(argv[3], "%30d", &priority) != 1 || priority < 1) {
      /* Lookup the priority label */
      if ((priority = ast_findlabel_extension(chan, argv[1], argv[2], argv[3], chan->cid.cid_num)) < 0) {
         ast_log(LOG_ERROR, "Priority '%s' not found in '%s@%s'\n", argv[3], argv[2], argv[1]);
         ast_agi_send(agi->fd, chan, "200 result=-1 Gosub label not found\n");
         return RESULT_FAILURE;
      }
   } else if (!ast_exists_extension(chan, argv[1], argv[2], priority, chan->cid.cid_num)) {
      ast_agi_send(agi->fd, chan, "200 result=-1 Gosub label not found\n");
      return RESULT_FAILURE;
   }

   /* Save previous location, since we're going to change it */
   ast_copy_string(old_context, chan->context, sizeof(old_context));
   ast_copy_string(old_extension, chan->exten, sizeof(old_extension));
   old_priority = chan->priority;

   if (!(theapp = pbx_findapp("Gosub"))) {
      ast_log(LOG_ERROR, "Gosub() cannot be found in the list of loaded applications\n");
      ast_agi_send(agi->fd, chan, "503 result=-2 Gosub is not loaded\n");
      return RESULT_FAILURE;
   }

   /* Apparently, if you run ast_pbx_run on a channel that already has a pbx
    * structure, you need to add 1 to the priority to get it to go to the
    * right place.  But if it doesn't have a pbx structure, then leaving off
    * the 1 is the right thing to do.  See how this code differs when we
    * call a Gosub for the CALLEE channel in Dial or Queue.
    */
   if (argc == 5) {
      if (asprintf(&gosub_args, "%s,%s,%d(%s)", argv[1], argv[2], priority + (chan->pbx ? 1 : 0), argv[4]) < 0) {
         ast_log(LOG_WARNING, "asprintf() failed: %s\n", strerror(errno));
         gosub_args = NULL;
      }
   } else {
      if (asprintf(&gosub_args, "%s,%s,%d", argv[1], argv[2], priority + (chan->pbx ? 1 : 0)) < 0) {
         ast_log(LOG_WARNING, "asprintf() failed: %s\n", strerror(errno));
         gosub_args = NULL;
      }
   }

   if (gosub_args) {
      int res;

      ast_debug(1, "Trying gosub with arguments '%s'\n", gosub_args);

      if ((res = pbx_exec(chan, theapp, gosub_args)) == 0) {
         struct ast_pbx *pbx = chan->pbx;
         struct ast_pbx_args args;
         struct ast_datastore *stack_store = ast_channel_datastore_find(chan, &stack_info, NULL);
         AST_LIST_HEAD(, gosub_stack_frame) *oldlist = stack_store->data;
         struct gosub_stack_frame *cur = AST_LIST_FIRST(oldlist);
         cur->is_agi = 1;

         memset(&args, 0, sizeof(args));
         args.no_hangup_chan = 1;
         /* Suppress warning about PBX already existing */
         chan->pbx = NULL;
         ast_agi_send(agi->fd, chan, "100 result=0 Trying...\n");
         ast_pbx_run_args(chan, &args);
         ast_agi_send(agi->fd, chan, "200 result=0 Gosub complete\n");
         if (chan->pbx) {
            ast_free(chan->pbx);
         }
         chan->pbx = pbx;
      } else {
         ast_agi_send(agi->fd, chan, "200 result=%d Gosub failed\n", res);
      }
      ast_free(gosub_args);
   } else {
      ast_agi_send(agi->fd, chan, "503 result=-2 Memory allocation failure\n");
      return RESULT_FAILURE;
   }

   /* Restore previous location */
   ast_copy_string(chan->context, old_context, sizeof(chan->context));
   ast_copy_string(chan->exten, old_extension, sizeof(chan->exten));
   chan->priority = old_priority;

   return RESULT_SUCCESS;
}

static int load_module

(

void

)

[static]

Definition at line 533 of file app_stack.c.

References ast_agi_register(), ast_custom_function_register, ast_register_application, gosub_agi_command, gosub_exec(), gosubif_exec(), local_function, pop_exec(), and return_exec().

{
   /* usage of AGI is optional, so check to see if the ast_agi_register()
      function is available; if so, use it.
   */
   if (ast_agi_register) {
      ast_agi_register(ast_module_info->self, &gosub_agi_command);
   }

   ast_register_application(app_pop, pop_exec, pop_synopsis, pop_descrip);
   ast_register_application(app_return, return_exec, return_synopsis, return_descrip);
   ast_register_application(app_gosubif, gosubif_exec, gosubif_synopsis, gosubif_descrip);
   ast_register_application(app_gosub, gosub_exec, gosub_synopsis, gosub_descrip);
   ast_custom_function_register(&local_function);

   return 0;
}

static int local_read	(	struct ast_channel *	chan,
		const char *	cmd,
		char *	data,
		char *	buf,
		size_t	len
	)			[static]

Definition at line 352 of file app_stack.c.

References ast_channel_datastore_find(), ast_channel_lock, ast_channel_unlock, ast_copy_string(), AST_LIST_FIRST, AST_LIST_HEAD, AST_LIST_LOCK, AST_LIST_TRAVERSE, AST_LIST_UNLOCK, ast_var_name(), ast_datastore::data, gosub_stack_frame::entries, pbx_builtin_getvar_helper(), S_OR, and gosub_stack_frame::varshead.

{
   struct ast_datastore *stack_store = ast_channel_datastore_find(chan, &stack_info, NULL);
   AST_LIST_HEAD(, gosub_stack_frame) *oldlist;
   struct gosub_stack_frame *frame;
   struct ast_var_t *variables;

   if (!stack_store)
      return -1;

   oldlist = stack_store->data;
   AST_LIST_LOCK(oldlist);
   if (!(frame = AST_LIST_FIRST(oldlist))) {
      /* Not within a Gosub routine */
      AST_LIST_UNLOCK(oldlist);
      return -1;
   }

   AST_LIST_TRAVERSE(&frame->varshead, variables, entries) {
      if (!strcmp(data, ast_var_name(variables))) {
         const char *tmp;
         ast_channel_lock(chan);
         tmp = pbx_builtin_getvar_helper(chan, data);
         ast_copy_string(buf, S_OR(tmp, ""), len);
         ast_channel_unlock(chan);
         break;
      }
   }
   AST_LIST_UNLOCK(oldlist);
   return 0;
}

static int local_write	(	struct ast_channel *	chan,
		const char *	cmd,
		char *	var,
		const char *	value
	)			[static]

Definition at line 384 of file app_stack.c.

References ast_channel_datastore_find(), AST_LIST_FIRST, AST_LIST_HEAD, AST_LIST_LOCK, AST_LIST_UNLOCK, ast_log(), ast_datastore::data, frame_set_var(), and LOG_ERROR.

{
   struct ast_datastore *stack_store = ast_channel_datastore_find(chan, &stack_info, NULL);
   AST_LIST_HEAD(, gosub_stack_frame) *oldlist;
   struct gosub_stack_frame *frame;

   if (!stack_store) {
      ast_log(LOG_ERROR, "Tried to set LOCAL(%s), but we aren't within a Gosub routine\n", var);
      return -1;
   }

   oldlist = stack_store->data;
   AST_LIST_LOCK(oldlist);
   frame = AST_LIST_FIRST(oldlist);

   if (frame)
      frame_set_var(chan, frame, var, value);

   AST_LIST_UNLOCK(oldlist);

   return 0;
}

static int pop_exec	(	struct ast_channel *	chan,
		void *	data
	)			[static]

Definition at line 169 of file app_stack.c.

References ast_channel_datastore_find(), ast_debug, AST_LIST_HEAD, AST_LIST_LOCK, AST_LIST_REMOVE_HEAD, AST_LIST_UNLOCK, ast_log(), ast_datastore::data, gosub_stack_frame::entries, gosub_release_frame(), and LOG_WARNING.

Referenced by load_module().

{
   struct ast_datastore *stack_store = ast_channel_datastore_find(chan, &stack_info, NULL);
   struct gosub_stack_frame *oldframe;
   AST_LIST_HEAD(, gosub_stack_frame) *oldlist;

   if (!stack_store) {
      ast_log(LOG_WARNING, "%s called with no gosub stack allocated.\n", app_pop);
      return 0;
   }

   oldlist = stack_store->data;
   AST_LIST_LOCK(oldlist);
   oldframe = AST_LIST_REMOVE_HEAD(oldlist, entries);
   AST_LIST_UNLOCK(oldlist);

   if (oldframe) {
      gosub_release_frame(chan, oldframe);
   } else {
      ast_debug(1, "%s called with an empty gosub stack\n", app_pop);
   }
   return 0;
}

static int return_exec	(	struct ast_channel *	chan,
		void *	data
	)			[static]

Definition at line 193 of file app_stack.c.

References ast_channel_datastore_find(), ast_explicit_goto(), AST_LIST_HEAD, AST_LIST_LOCK, AST_LIST_REMOVE_HEAD, AST_LIST_UNLOCK, ast_log(), gosub_stack_frame::context, ast_datastore::data, gosub_stack_frame::entries, gosub_stack_frame::extension, gosub_release_frame(), gosub_stack_frame::is_agi, LOG_ERROR, pbx_builtin_setvar_helper(), gosub_stack_frame::priority, and S_OR.

Referenced by load_module().

{
   struct ast_datastore *stack_store = ast_channel_datastore_find(chan, &stack_info, NULL);
   struct gosub_stack_frame *oldframe;
   AST_LIST_HEAD(, gosub_stack_frame) *oldlist;
   char *retval = data;
   int res = 0;

   if (!stack_store) {
      ast_log(LOG_ERROR, "Return without Gosub: stack is unallocated\n");
      return -1;
   }

   oldlist = stack_store->data;
   AST_LIST_LOCK(oldlist);
   oldframe = AST_LIST_REMOVE_HEAD(oldlist, entries);
   AST_LIST_UNLOCK(oldlist);

   if (!oldframe) {
      ast_log(LOG_ERROR, "Return without Gosub: stack is empty\n");
      return -1;
   } else if (oldframe->is_agi) {
      /* Exit from AGI */
      res = -1;
   }

   ast_explicit_goto(chan, oldframe->context, oldframe->extension, oldframe->priority);
   gosub_release_frame(chan, oldframe);

   /* Set a return value, if any */
   pbx_builtin_setvar_helper(chan, "GOSUB_RETVAL", S_OR(retval, ""));
   return res;
}

static int unload_module

(

void

)

[static]

Definition at line 518 of file app_stack.c.

References ast_agi_unregister(), ast_custom_function_unregister(), ast_unregister_application(), gosub_agi_command, and local_function.

{
   if (ast_agi_unregister) {
       ast_agi_unregister(ast_module_info->self, &gosub_agi_command);
   }

   ast_unregister_application(app_return);
   ast_unregister_application(app_pop);
   ast_unregister_application(app_gosubif);
   ast_unregister_application(app_gosub);
   ast_custom_function_unregister(&local_function);

   return 0;
}

---

Variable Documentation

struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_DEFAULT , .description = "Dialplan subroutines (Gosub, Return, etc)" , .key = "This paragraph is copyright (c) 2006 by Digium, Inc. \In order for your module to load, it must return this \key via a function called \"key\". Any code which \includes this paragraph must be licensed under the GNU \General Public License version 2 or later (at your \option). In addition to Digium's general reservations \of rights, Digium expressly reserves the right to \allow other parties to license this paragraph under \different terms. Any use of Digium, Inc. trademarks or \logos (including \"Asterisk\" or \"Digium\") without \express written permission of Digium, Inc. is prohibited.\n" , .buildopt_sum = "a9c98e5d177805051735cb5b0b16b0a0" , .load = load_module, .unload = unload_module, } [static]

Definition at line 551 of file app_stack.c.

const char* app_gosub = "Gosub" [static]

Definition at line 47 of file app_stack.c.

const char* app_gosubif = "GosubIf" [static]

Definition at line 48 of file app_stack.c.

const char* app_pop = "StackPop" [static]

Definition at line 50 of file app_stack.c.

const char* app_return = "Return" [static]

Definition at line 49 of file app_stack.c.

struct ast_module_info* ast_module_info = &__mod_info [static]

Definition at line 551 of file app_stack.c.

struct agi_command gosub_agi_command

Initial value:

   { { "gosub", NULL }, handle_gosub, "Execute a dialplan subroutine", usage_gosub , 0 }

Definition at line 515 of file app_stack.c.

Referenced by load_module(), and unload_module().

const char* gosub_descrip [static]

Initial value:

"  Gosub([[context,]exten,]priority[(arg1[,...][,argN])]):\n"
"Jumps to the label specified, saving the return address.\n"

Definition at line 57 of file app_stack.c.

const char* gosub_synopsis = "Jump to label, saving return address" [static]

Definition at line 52 of file app_stack.c.

const char* gosubif_descrip [static]

Initial value:

"  GosubIf(condition?labeliftrue[(arg1[,...])][:labeliffalse[(arg1[,...])]]):\n"
"If the condition is true, then jump to labeliftrue.  If false, jumps to\n"
"labeliffalse, if specified.  In either case, a jump saves the return point\n"
"in the dialplan, to be returned to with a Return.\n"

Definition at line 60 of file app_stack.c.

const char* gosubif_synopsis = "Conditionally jump to label, saving return address" [static]

Definition at line 53 of file app_stack.c.

struct ast_custom_function local_function [static]

Definition at line 407 of file app_stack.c.

Referenced by load_module(), and unload_module().

const char* pop_descrip [static]

Initial value:

"  StackPop():\n"
"Removes last label on the stack, discarding it.\n"

Definition at line 69 of file app_stack.c.

const char* pop_synopsis = "Remove one address from gosub stack" [static]

Definition at line 55 of file app_stack.c.

const char* return_descrip [static]

Initial value:

"  Return([return-value]):\n"
"Jumps to the last label on the stack, removing it.  The return value, if\n"
"any, is saved in the channel variable GOSUB_RETVAL.\n"

Definition at line 65 of file app_stack.c.

const char* return_synopsis = "Return from gosub routine" [static]

Definition at line 54 of file app_stack.c.

struct ast_datastore_info stack_info [static]

Initial value:

 {
   .type = "GOSUB",
   .destroy = gosub_free,
}

Definition at line 75 of file app_stack.c.

char usage_gosub[] [static]

Initial value:

" Usage: GOSUB <context> <extension> <priority> [<optional-argument>]\n"
"   Cause the channel to execute the specified dialplan subroutine, returning\n"
" to the dialplan with execution of a Return()\n"

Definition at line 510 of file app_stack.c.