Mon Apr 30 07:36:28 2007

Asterisk developer's documentation

---

app_macro.c

Go to the documentation of this file.

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2005, Digium, Inc.
 *
 * Mark Spencer <markster@digium.com>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 *
 * \brief Dial plan macro Implementation
 *
 * \author Mark Spencer <markster@digium.com>
 * 
 * \ingroup applications
 */

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision$")

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>

#include "asterisk/file.h"
#include "asterisk/logger.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/module.h"
#include "asterisk/options.h"
#include "asterisk/config.h"
#include "asterisk/utils.h"
#include "asterisk/lock.h"

#define MAX_ARGS 80

/* special result value used to force macro exit */
#define MACRO_EXIT_RESULT 1024

static char *descrip =
"  Macro(macroname|arg1|arg2...): Executes a macro using the context\n"
"'macro-<macroname>', jumping to the 's' extension of that context and\n"
"executing each step, then returning when the steps end. \n"
"The calling extension, context, and priority are stored in ${MACRO_EXTEN}, \n"
"${MACRO_CONTEXT} and ${MACRO_PRIORITY} respectively.  Arguments become\n"
"${ARG1}, ${ARG2}, etc in the macro context.\n"
"If you Goto out of the Macro context, the Macro will terminate and control\n"
"will be returned at the location of the Goto.\n"
"If ${MACRO_OFFSET} is set at termination, Macro will attempt to continue\n"
"at priority MACRO_OFFSET + N + 1 if such a step exists, and N + 1 otherwise.\n"
"Extensions: While a macro is being executed, it becomes the current context.\n"
"            This means that if a hangup occurs, for instance, that the macro\n"
"            will be searched for an 'h' extension, NOT the context from which\n"
"            the macro was called. So, make sure to define all appropriate\n"
"            extensions in your macro! (you can use 'catch' in AEL) \n"
"WARNING: Because of the way Macro is implemented (it executes the priorities\n"
"         contained within it via sub-engine), and a fixed per-thread\n"
"         memory stack allowance, macros are limited to 7 levels\n"
"         of nesting (macro calling macro calling macro, etc.); It\n"
"         may be possible that stack-intensive applications in deeply nested macros\n"
"         could cause asterisk to crash earlier than this limit. It is advised that\n"
"         if you need to deeply nest macro calls, that you use the Gosub application\n"
"         (now allows arguments like a Macro) with explict Return() calls instead.\n";

static char *if_descrip =
"  MacroIf(<expr>?macroname_a[|arg1][:macroname_b[|arg1]])\n"
"Executes macro defined in <macroname_a> if <expr> is true\n"
"(otherwise <macroname_b> if provided)\n"
"Arguments and return values as in application macro()\n";

static char *exclusive_descrip =
"  MacroExclusive(macroname|arg1|arg2...):\n"
"Executes macro defined in the context 'macro-macroname'\n"
"Only one call at a time may run the macro.\n"
"(we'll wait if another call is busy executing in the Macro)\n"
"Arguments and return values as in application Macro()\n";

static char *exit_descrip =
"  MacroExit():\n"
"Causes the currently running macro to exit as if it had\n"
"ended normally by running out of priorities to execute.\n"
"If used outside a macro, will likely cause unexpected\n"
"behavior.\n";

static char *app = "Macro";
static char *if_app = "MacroIf";
static char *exclusive_app = "MacroExclusive";
static char *exit_app = "MacroExit";

static char *synopsis = "Macro Implementation";
static char *if_synopsis = "Conditional Macro Implementation";
static char *exclusive_synopsis = "Exclusive Macro Implementation";
static char *exit_synopsis = "Exit From Macro";


static struct ast_exten *find_matching_priority(struct ast_context *c, const char *exten, int priority, const char *callerid)
{
   struct ast_exten *e;
   struct ast_include *i;
   struct ast_context *c2;

   for (e=ast_walk_context_extensions(c, NULL); e; e=ast_walk_context_extensions(c, e)) {
      if (ast_extension_match(ast_get_extension_name(e), exten)) {
         int needmatch = ast_get_extension_matchcid(e);
         if ((needmatch && ast_extension_match(ast_get_extension_cidmatch(e), callerid)) ||
            (!needmatch)) {
            /* This is the matching extension we want */
            struct ast_exten *p;
            for (p=ast_walk_extension_priorities(e, NULL); p; p=ast_walk_extension_priorities(e, p)) {
               if (priority != ast_get_extension_priority(p))
                  continue;
               return p;
            }
         }
      }
   }

   /* No match; run through includes */
   for (i=ast_walk_context_includes(c, NULL); i; i=ast_walk_context_includes(c, i)) {
      for (c2=ast_walk_contexts(NULL); c2; c2=ast_walk_contexts(c2)) {
         if (!strcmp(ast_get_context_name(c2), ast_get_include_name(i))) {
            e = find_matching_priority(c2, exten, priority, callerid);
            if (e)
               return e;
         }
      }
   }
   return NULL;
}

static int _macro_exec(struct ast_channel *chan, void *data, int exclusive)
{
   const char *s;
   char *tmp;
   char *cur, *rest;
   char *macro;
   char fullmacro[80];
   char varname[80];
   char *oldargs[MAX_ARGS + 1] = { NULL, };
   int argc, x;
   int res=0;
   char oldexten[256]="";
   int oldpriority, gosub_level = 0;
   char pc[80], depthc[12];
   char oldcontext[AST_MAX_CONTEXT] = "";
   const char *inhangupc;
   int offset, depth = 0, maxdepth = 7;
   int setmacrocontext=0;
   int autoloopflag, dead = 0, inhangup = 0;
  
   char *save_macro_exten;
   char *save_macro_context;
   char *save_macro_priority;
   char *save_macro_offset;
   struct ast_module_user *u;
 
   struct ast_context *c;
   struct ast_exten *e;

   if (ast_strlen_zero(data)) {
      ast_log(LOG_WARNING, "Macro() requires arguments. See \"show application macro\" for help.\n");
      return -1;
   }

   u = ast_module_user_add(chan);

   /* does the user want a deeper rabbit hole? */
   s = pbx_builtin_getvar_helper(chan, "MACRO_RECURSION");
   if (s)
      sscanf(s, "%d", &maxdepth);

   /* Count how many levels deep the rabbit hole goes */
   s = pbx_builtin_getvar_helper(chan, "MACRO_DEPTH");
   if (s)
      sscanf(s, "%d", &depth);
   /* Used for detecting whether to return when a Macro is called from another Macro after hangup */
   if (strcmp(chan->exten, "h") == 0)
      pbx_builtin_setvar_helper(chan, "MACRO_IN_HANGUP", "1");
   inhangupc = pbx_builtin_getvar_helper(chan, "MACRO_IN_HANGUP");
   if (!ast_strlen_zero(inhangupc))
      sscanf(inhangupc, "%d", &inhangup);

   if (depth >= maxdepth) {
      ast_log(LOG_ERROR, "Macro():  possible infinite loop detected.  Returning early.\n");
      ast_module_user_remove(u);
      return 0;
   }
   snprintf(depthc, sizeof(depthc), "%d", depth + 1);
   pbx_builtin_setvar_helper(chan, "MACRO_DEPTH", depthc);

   tmp = ast_strdupa(data);
   rest = tmp;
   macro = strsep(&rest, "|");
   if (ast_strlen_zero(macro)) {
      ast_log(LOG_WARNING, "Invalid macro name specified\n");
      ast_module_user_remove(u);
      return 0;
   }

   snprintf(fullmacro, sizeof(fullmacro), "macro-%s", macro);
   if (!ast_exists_extension(chan, fullmacro, "s", 1, chan->cid.cid_num)) {
      if (!ast_context_find(fullmacro)) 
         ast_log(LOG_WARNING, "No such context '%s' for macro '%s'\n", fullmacro, macro);
      else
         ast_log(LOG_WARNING, "Context '%s' for macro '%s' lacks 's' extension, priority 1\n", fullmacro, macro);
      ast_module_user_remove(u);
      return 0;
   }

   /* If we are to run the macro exclusively, take the mutex */
   if (exclusive) {
      ast_log(LOG_DEBUG, "Locking macrolock for '%s'\n", fullmacro);
      ast_autoservice_start(chan);
      if (ast_context_lockmacro(fullmacro)) {
         ast_log(LOG_WARNING, "Failed to lock macro '%s' as in-use\n", fullmacro);
         ast_autoservice_stop(chan);
         ast_module_user_remove(u);

         return 0;
      }
      ast_autoservice_stop(chan);
   }
   
   /* Save old info */
   oldpriority = chan->priority;
   ast_copy_string(oldexten, chan->exten, sizeof(oldexten));
   ast_copy_string(oldcontext, chan->context, sizeof(oldcontext));
   if (ast_strlen_zero(chan->macrocontext)) {
      ast_copy_string(chan->macrocontext, chan->context, sizeof(chan->macrocontext));
      ast_copy_string(chan->macroexten, chan->exten, sizeof(chan->macroexten));
      chan->macropriority = chan->priority;
      setmacrocontext=1;
   }
   argc = 1;
   /* Save old macro variables */
   save_macro_exten = ast_strdup(pbx_builtin_getvar_helper(chan, "MACRO_EXTEN"));
   pbx_builtin_setvar_helper(chan, "MACRO_EXTEN", oldexten);

   save_macro_context = ast_strdup(pbx_builtin_getvar_helper(chan, "MACRO_CONTEXT"));
   pbx_builtin_setvar_helper(chan, "MACRO_CONTEXT", oldcontext);

   save_macro_priority = ast_strdup(pbx_builtin_getvar_helper(chan, "MACRO_PRIORITY"));
   snprintf(pc, sizeof(pc), "%d", oldpriority);
   pbx_builtin_setvar_helper(chan, "MACRO_PRIORITY", pc);
  
   save_macro_offset = ast_strdup(pbx_builtin_getvar_helper(chan, "MACRO_OFFSET"));
   pbx_builtin_setvar_helper(chan, "MACRO_OFFSET", NULL);

   /* Setup environment for new run */
   chan->exten[0] = 's';
   chan->exten[1] = '\0';
   ast_copy_string(chan->context, fullmacro, sizeof(chan->context));
   chan->priority = 1;

   while((cur = strsep(&rest, "|")) && (argc < MAX_ARGS)) {
      const char *s;
      /* Save copy of old arguments if we're overwriting some, otherwise
         let them pass through to the other macro */
      snprintf(varname, sizeof(varname), "ARG%d", argc);
      s = pbx_builtin_getvar_helper(chan, varname);
      if (s)
         oldargs[argc] = ast_strdup(s);
      pbx_builtin_setvar_helper(chan, varname, cur);
      argc++;
   }
   autoloopflag = ast_test_flag(chan, AST_FLAG_IN_AUTOLOOP);
   ast_set_flag(chan, AST_FLAG_IN_AUTOLOOP);
   while(ast_exists_extension(chan, chan->context, chan->exten, chan->priority, chan->cid.cid_num)) {
      /* What application will execute? */
      for (c = ast_walk_contexts(NULL), e = NULL; c; c = ast_walk_contexts(c)) {
         if (!strcmp(ast_get_context_name(c), chan->context)) {
            e = find_matching_priority(c, chan->exten, chan->priority, chan->cid.cid_num);
            break;
         }
      }

      /* Reset the macro depth, if it was changed in the last iteration */
      pbx_builtin_setvar_helper(chan, "MACRO_DEPTH", depthc);

      if ((res = ast_spawn_extension(chan, chan->context, chan->exten, chan->priority, chan->cid.cid_num))) {
         /* Something bad happened, or a hangup has been requested. */
         if (((res >= '0') && (res <= '9')) || ((res >= 'A') && (res <= 'F')) ||
            (res == '*') || (res == '#')) {
            /* Just return result as to the previous application as if it had been dialed */
            ast_log(LOG_DEBUG, "Oooh, got something to jump out with ('%c')!\n", res);
            break;
         }
         switch(res) {
         case MACRO_EXIT_RESULT:
            res = 0;
            goto out;
         case AST_PBX_KEEPALIVE:
            if (option_debug)
               ast_log(LOG_DEBUG, "Spawn extension (%s,%s,%d) exited KEEPALIVE in macro %s on '%s'\n", chan->context, chan->exten, chan->priority, macro, chan->name);
            else if (option_verbose > 1)
               ast_verbose( VERBOSE_PREFIX_2 "Spawn extension (%s, %s, %d) exited KEEPALIVE in macro '%s' on '%s'\n", chan->context, chan->exten, chan->priority, macro, chan->name);
            goto out;
            break;
         default:
            if (option_debug)
               ast_log(LOG_DEBUG, "Spawn extension (%s,%s,%d) exited non-zero on '%s' in macro '%s'\n", chan->context, chan->exten, chan->priority, chan->name, macro);
            else if (option_verbose > 1)
               ast_verbose( VERBOSE_PREFIX_2 "Spawn extension (%s, %s, %d) exited non-zero on '%s' in macro '%s'\n", chan->context, chan->exten, chan->priority, chan->name, macro);
            dead = 1;
            goto out;
         }
      }

      ast_log(LOG_DEBUG, "Executed application: %s\n", ast_get_extension_app(e));

      if (e && !strcasecmp(ast_get_extension_app(e), "GOSUB")) {
         gosub_level++;
         ast_log(LOG_DEBUG, "Incrementing gosub_level\n");
      } else if (e && !strcasecmp(ast_get_extension_app(e), "GOSUBIF")) {
         const char *tmp = ast_get_extension_app_data(e);
         char tmp2[1024] = "", *cond, *app, *app2 = tmp2;
         pbx_substitute_variables_helper(chan, tmp, tmp2, sizeof(tmp2) - 1);
         cond = strsep(&app2, "?");
         app = strsep(&app2, ":");
         if (pbx_checkcondition(cond)) {
            if (!ast_strlen_zero(app)) {
               gosub_level++;
               ast_log(LOG_DEBUG, "Incrementing gosub_level\n");
            }
         } else {
            if (!ast_strlen_zero(app2)) {
               gosub_level++;
               ast_log(LOG_DEBUG, "Incrementing gosub_level\n");
            }
         }
      } else if (e && !strcasecmp(ast_get_extension_app(e), "RETURN")) {
         gosub_level--;
         ast_log(LOG_DEBUG, "Decrementing gosub_level\n");
      } else if (e && !strcasecmp(ast_get_extension_app(e), "STACKPOP")) {
         gosub_level--;
         ast_log(LOG_DEBUG, "Decrementing gosub_level\n");
      } else if (e && !strncasecmp(ast_get_extension_app(e), "EXEC", 4)) {
         /* Must evaluate args to find actual app */
         const char *tmp = ast_get_extension_app_data(e);
         char tmp2[1024] = "", *tmp3 = NULL;
         pbx_substitute_variables_helper(chan, tmp, tmp2, sizeof(tmp2) - 1);
         if (!strcasecmp(ast_get_extension_app(e), "EXECIF")) {
            tmp3 = strchr(tmp2, '|');
            if (tmp3)
               *tmp3++ = '\0';
            if (!pbx_checkcondition(tmp2))
               tmp3 = NULL;
         } else
            tmp3 = tmp2;

         if (tmp3)
            ast_log(LOG_DEBUG, "Last app: %s\n", tmp3);

         if (tmp3 && !strncasecmp(tmp3, "GOSUB", 5)) {
            gosub_level++;
            ast_log(LOG_DEBUG, "Incrementing gosub_level\n");
         } else if (tmp3 && !strncasecmp(tmp3, "RETURN", 6)) {
            gosub_level--;
            ast_log(LOG_DEBUG, "Decrementing gosub_level\n");
         } else if (tmp3 && !strncasecmp(tmp3, "STACKPOP", 8)) {
            gosub_level--;
            ast_log(LOG_DEBUG, "Decrementing gosub_level\n");
         }
      }

      if (gosub_level == 0 && strcasecmp(chan->context, fullmacro)) {
         if (option_verbose > 1)
            ast_verbose(VERBOSE_PREFIX_2 "Channel '%s' jumping out of macro '%s'\n", chan->name, macro);
         break;
      }

      /* don't stop executing extensions when we're in "h" */
      if (chan->_softhangup && !inhangup) {
         ast_log(LOG_DEBUG, "Extension %s, macroexten %s, priority %d returned normally even though call was hung up\n",
            chan->exten, chan->macroexten, chan->priority);
         goto out;
      }
      chan->priority++;
   }
   out:
   /* Reset the depth back to what it was when the routine was entered (like if we called Macro recursively) */
   snprintf(depthc, sizeof(depthc), "%d", depth);
   if (!dead) {
      pbx_builtin_setvar_helper(chan, "MACRO_DEPTH", depthc);
      ast_set2_flag(chan, autoloopflag, AST_FLAG_IN_AUTOLOOP);
   }

   for (x = 1; x < argc; x++) {
      /* Restore old arguments and delete ours */
      snprintf(varname, sizeof(varname), "ARG%d", x);
      if (oldargs[x]) {
         if (!dead)
            pbx_builtin_setvar_helper(chan, varname, oldargs[x]);
         free(oldargs[x]);
      } else if (!dead) {
         pbx_builtin_setvar_helper(chan, varname, NULL);
      }
   }

   /* Restore macro variables */
   if (!dead) {
      pbx_builtin_setvar_helper(chan, "MACRO_EXTEN", save_macro_exten);
      pbx_builtin_setvar_helper(chan, "MACRO_CONTEXT", save_macro_context);
      pbx_builtin_setvar_helper(chan, "MACRO_PRIORITY", save_macro_priority);
   }
   if (save_macro_exten)
      free(save_macro_exten);
   if (save_macro_context)
      free(save_macro_context);
   if (save_macro_priority)
      free(save_macro_priority);

   if (!dead && setmacrocontext) {
      chan->macrocontext[0] = '\0';
      chan->macroexten[0] = '\0';
      chan->macropriority = 0;
   }

   if (!dead && !strcasecmp(chan->context, fullmacro)) {
      /* If we're leaving the macro normally, restore original information */
      chan->priority = oldpriority;
      ast_copy_string(chan->context, oldcontext, sizeof(chan->context));
      if (!(chan->_softhangup & AST_SOFTHANGUP_ASYNCGOTO)) {
         /* Copy the extension, so long as we're not in softhangup, where we could be given an asyncgoto */
         const char *offsets;
         ast_copy_string(chan->exten, oldexten, sizeof(chan->exten));
         if ((offsets = pbx_builtin_getvar_helper(chan, "MACRO_OFFSET"))) {
            /* Handle macro offset if it's set by checking the availability of step n + offset + 1, otherwise continue
               normally if there is any problem */
            if (sscanf(offsets, "%d", &offset) == 1) {
               if (ast_exists_extension(chan, chan->context, chan->exten, chan->priority + offset + 1, chan->cid.cid_num)) {
                  chan->priority += offset;
               }
            }
         }
      }
   }

   if (!dead)
      pbx_builtin_setvar_helper(chan, "MACRO_OFFSET", save_macro_offset);
   if (save_macro_offset)
      free(save_macro_offset);

   /* Unlock the macro */
   if (exclusive) {
      ast_log(LOG_DEBUG, "Unlocking macrolock for '%s'\n", fullmacro);
      if (ast_context_unlockmacro(fullmacro)) {
         ast_log(LOG_ERROR, "Failed to unlock macro '%s' - that isn't good\n", fullmacro);
         res = 0;
      }
   }
   
   ast_module_user_remove(u);

   return res;
}

static int macro_exec(struct ast_channel *chan, void *data)
{
   return _macro_exec(chan, data, 0);
}

static int macroexclusive_exec(struct ast_channel *chan, void *data)
{
   return _macro_exec(chan, data, 1);
}

static int macroif_exec(struct ast_channel *chan, void *data) 
{
   char *expr = NULL, *label_a = NULL, *label_b = NULL;
   int res = 0;
   struct ast_module_user *u;

   u = ast_module_user_add(chan);

   if (!(expr = ast_strdupa(data))) {
      ast_module_user_remove(u);
      return -1;
   }

   if ((label_a = strchr(expr, '?'))) {
      *label_a = '\0';
      label_a++;
      if ((label_b = strchr(label_a, ':'))) {
         *label_b = '\0';
         label_b++;
      }
      if (pbx_checkcondition(expr))
         macro_exec(chan, label_a);
      else if (label_b) 
         macro_exec(chan, label_b);
   } else
      ast_log(LOG_WARNING, "Invalid Syntax.\n");

   ast_module_user_remove(u);

   return res;
}
         
static int macro_exit_exec(struct ast_channel *chan, void *data)
{
   return MACRO_EXIT_RESULT;
}

static int unload_module(void)
{
   int res;

   res = ast_unregister_application(if_app);
   res |= ast_unregister_application(exit_app);
   res |= ast_unregister_application(app);
   res |= ast_unregister_application(exclusive_app);

   ast_module_user_hangup_all();

   return res;
}

static int load_module(void)
{
   int res;

   res = ast_register_application(exit_app, macro_exit_exec, exit_synopsis, exit_descrip);
   res |= ast_register_application(if_app, macroif_exec, if_synopsis, if_descrip);
   res |= ast_register_application(exclusive_app, macroexclusive_exec, exclusive_synopsis, exclusive_descrip);
   res |= ast_register_application(app, macro_exec, synopsis, descrip);

   return res;
}

AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Extension Macros");

---