apps/app_while.c

   1 /*
   2  * Asterisk -- An open source telephony toolkit.
   3  *
   4  * Copyright 2004 - 2005, Anthony Minessale <anthmct@yahoo.com>
   5  *
   6  * Anthony Minessale <anthmct@yahoo.com>
   7  *
   8  * See http://www.asterisk.org for more information about
   9  * the Asterisk project. Please do not directly contact
  10  * any of the maintainers of this project for assistance;
  11  * the project provides a web site, mailing lists and IRC
  12  * channels for your use.
  13  *
  14  * This program is free software, distributed under the terms of
  15  * the GNU General Public License Version 2. See the LICENSE file
  16  * at the top of the source tree.
  17  */
  18
  19 /*! \file
  20  *
  21  * \brief While Loop Implementation
  22  *
  23  * \author Anthony Minessale <anthmct@yahoo.com>
  24  *
  25  * \ingroup applications
  26  */
  27
  28 #include "asterisk.h"
  29
  30 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  31
  32 #include "asterisk/pbx.h"
  33 #include "asterisk/module.h"
  34 #include "asterisk/channel.h"
  35
  36 static char *start_app = "While";
  37 static char *start_desc =
  38 "  While(<expr>): Start a While Loop.  Execution will return to this\n"
  39 "point when EndWhile() is called until expr is no longer true.\n";
  40
  41 static char *start_synopsis = "Start a while loop";
  42
  43
  44 static char *stop_app = "EndWhile";
  45 static char *stop_desc =
  46 "  EndWhile(): Return to the previous called While()\n";
  47
  48 static char *stop_synopsis = "End a while loop";
  49
  50 static char *exit_app = "ExitWhile";
  51 static char *exit_desc =
  52 "  ExitWhile(): Exits a While() loop, whether or not the conditional has been satisfied.\n";
  53 static char *exit_synopsis = "End a While loop";
  54
  55 static char *continue_app = "ContinueWhile";
  56 static char *continue_desc =
  57 "  ContinueWhile(): Returns to the top of the while loop and re-evaluates the conditional.\n";
  58 static char *continue_synopsis = "Restart a While loop";
  59
  60 #define VAR_SIZE 64
  61
  62
  63 static const char *get_index(struct ast_channel *chan, const char *prefix, int index) {
  64         char varname[VAR_SIZE];
  65
  66         snprintf(varname, VAR_SIZE, "%s_%d", prefix, index);
  67         return pbx_builtin_getvar_helper(chan, varname);
  68 }
  69
  70 static struct ast_exten *find_matching_priority(struct ast_context *c, const char *exten, int priority, const char *callerid)
  71 {
  72         struct ast_exten *e;
  73         struct ast_include *i;
  74         struct ast_context *c2;
  75
  76         for (e=ast_walk_context_extensions(c, NULL); e; e=ast_walk_context_extensions(c, e)) {
  77                 if (ast_extension_match(ast_get_extension_name(e), exten)) {
  78                         int needmatch = ast_get_extension_matchcid(e);
  79                         if ((needmatch && ast_extension_match(ast_get_extension_cidmatch(e), callerid)) ||
  80                                 (!needmatch)) {
  81                                 /* This is the matching extension we want */
  82                                 struct ast_exten *p;
  83                                 for (p=ast_walk_extension_priorities(e, NULL); p; p=ast_walk_extension_priorities(e, p)) {
  84                                         if (priority != ast_get_extension_priority(p))
  85                                                 continue;
  86                                         return p;
  87                                 }
  88                         }
  89                 }
  90         }
  91
  92         /* No match; run through includes */
  93         for (i=ast_walk_context_includes(c, NULL); i; i=ast_walk_context_includes(c, i)) {
  94                 for (c2=ast_walk_contexts(NULL); c2; c2=ast_walk_contexts(c2)) {
  95                         if (!strcmp(ast_get_context_name(c2), ast_get_include_name(i))) {
  96                                 e = find_matching_priority(c2, exten, priority, callerid);
  97                                 if (e)
  98                                         return e;
  99                         }
 100                 }
 101         }
 102         return NULL;
 103 }
 104
 105 static int find_matching_endwhile(struct ast_channel *chan)
 106 {
 107         struct ast_context *c;
 108         int res=-1;
 109
 110         if (ast_rdlock_contexts()) {
 111                 ast_log(LOG_ERROR, "Failed to lock contexts list\n");
 112                 return -1;
 113         }
 114
 115         for (c=ast_walk_contexts(NULL); c; c=ast_walk_contexts(c)) {
 116                 struct ast_exten *e;
 117
 118                 if (!ast_rdlock_context(c)) {
 119                         if (!strcmp(ast_get_context_name(c), chan->context)) {
 120                                 /* This is the matching context we want */
 121                                 int cur_priority = chan->priority + 1, level=1;
 122
 123                                 for (e = find_matching_priority(c, chan->exten, cur_priority, chan->cid.cid_num); e; e = find_matching_priority(c, chan->exten, ++cur_priority, chan->cid.cid_num)) {
 124                                         if (!strcasecmp(ast_get_extension_app(e), "WHILE")) {
 125                                                 level++;
 126                                         } else if (!strcasecmp(ast_get_extension_app(e), "ENDWHILE")) {
 127                                                 level--;
 128                                         }
 129
 130                                         if (level == 0) {
 131                                                 res = cur_priority;
 132                                                 break;
 133                                         }
 134                                 }
 135                         }
 136                         ast_unlock_context(c);
 137                         if (res > 0) {
 138                                 break;
 139                         }
 140                 }
 141         }
 142         ast_unlock_contexts();
 143         return res;
 144 }
 145
 146 static int _while_exec(struct ast_channel *chan, void *data, int end)
 147 {
 148         int res=0;
 149         const char *while_pri = NULL;
 150         char *my_name = NULL;
 151         const char *condition = NULL, *label = NULL;
 152         char varname[VAR_SIZE], end_varname[VAR_SIZE];
 153         const char *prefix = "WHILE";
 154         size_t size=0;
 155         int used_index_i = -1, x=0;
 156         char used_index[VAR_SIZE] = "0", new_index[VAR_SIZE] = "0";
 157
 158         if (!chan) {
 159                 /* huh ? */
 160                 return -1;
 161         }
 162
 163         /* dont want run away loops if the chan isn't even up
 164            this is up for debate since it slows things down a tad ......
 165         */
 166         if (ast_waitfordigit(chan,1) < 0)
 167                 return -1;
 168
 169         for (x=0;;x++) {
 170                 if (get_index(chan, prefix, x)) {
 171                         used_index_i = x;
 172                 } else
 173                         break;
 174         }
 175
 176         snprintf(used_index, VAR_SIZE, "%d", used_index_i);
 177         snprintf(new_index, VAR_SIZE, "%d", used_index_i + 1);
 178
 179         if (!end)
 180                 condition = ast_strdupa(data);
 181
 182         size = strlen(chan->context) + strlen(chan->exten) + 32;
 183         my_name = alloca(size);
 184         memset(my_name, 0, size);
 185         snprintf(my_name, size, "%s_%s_%d", chan->context, chan->exten, chan->priority);
 186
 187         ast_channel_lock(chan);
 188         if (end) {
 189                 label = used_index;
 190         } else if (!(label = pbx_builtin_getvar_helper(chan, my_name))) {
 191                 label = new_index;
 192                 pbx_builtin_setvar_helper(chan, my_name, label);
 193         }
 194         snprintf(varname, VAR_SIZE, "%s_%s", prefix, label);
 195         if ((while_pri = pbx_builtin_getvar_helper(chan, varname)) && !end) {
 196                 while_pri = ast_strdupa(while_pri);
 197                 snprintf(end_varname,VAR_SIZE,"END_%s",varname);
 198         }
 199         ast_channel_unlock(chan);
 200
 201
 202         if ((!end && !pbx_checkcondition(condition)) || (end == 2)) {
 203                 /* Condition Met (clean up helper vars) */
 204                 const char *goto_str;
 205                 pbx_builtin_setvar_helper(chan, varname, NULL);
 206                 pbx_builtin_setvar_helper(chan, my_name, NULL);
 207                 snprintf(end_varname,VAR_SIZE,"END_%s",varname);
 208                 ast_channel_lock(chan);
 209                 if ((goto_str = pbx_builtin_getvar_helper(chan, end_varname))) {
 210                         ast_parseable_goto(chan, goto_str);
 211                         pbx_builtin_setvar_helper(chan, end_varname, NULL);
 212                 } else {
 213                         int pri = find_matching_endwhile(chan);
 214                         if (pri > 0) {
 215                                 ast_verb(3, "Jumping to priority %d\n", pri);
 216                                 chan->priority = pri;
 217                         } else {
 218                                 ast_log(LOG_WARNING, "Couldn't find matching EndWhile? (While at %s@%s priority %d)\n", chan->context, chan->exten, chan->priority);
 219                         }
 220                 }
 221                 ast_channel_unlock(chan);
 222                 return res;
 223         }
 224
 225         if (!end && !while_pri) {
 226                 char *goto_str;
 227                 size = strlen(chan->context) + strlen(chan->exten) + 32;
 228                 goto_str = alloca(size);
 229                 memset(goto_str, 0, size);
 230                 snprintf(goto_str, size, "%s,%s,%d", chan->context, chan->exten, chan->priority);
 231                 pbx_builtin_setvar_helper(chan, varname, goto_str);
 232         }
 233
 234         else if (end && while_pri) {
 235                 /* END of loop */
 236                 snprintf(end_varname, VAR_SIZE, "END_%s", varname);
 237                 if (! pbx_builtin_getvar_helper(chan, end_varname)) {
 238                         char *goto_str;
 239                         size = strlen(chan->context) + strlen(chan->exten) + 32;
 240                         goto_str = alloca(size);
 241                         memset(goto_str, 0, size);
 242                         snprintf(goto_str, size, "%s,%s,%d", chan->context, chan->exten, chan->priority+1);
 243                         pbx_builtin_setvar_helper(chan, end_varname, goto_str);
 244                 }
 245                 ast_parseable_goto(chan, while_pri);
 246         }
 247
 248         return res;
 249 }
 250
 251 static int while_start_exec(struct ast_channel *chan, void *data) {
 252         return _while_exec(chan, data, 0);
 253 }
 254
 255 static int while_end_exec(struct ast_channel *chan, void *data) {
 256         return _while_exec(chan, data, 1);
 257 }
 258
 259 static int while_exit_exec(struct ast_channel *chan, void *data) {
 260         return _while_exec(chan, data, 2);
 261 }
 262
 263 static int while_continue_exec(struct ast_channel *chan, void *data)
 264 {
 265         int x;
 266         const char *prefix = "WHILE", *while_pri=NULL;
 267
 268         for (x = 0; ; x++) {
 269                 const char *tmp = get_index(chan, prefix, x);
 270                 if (tmp)
 271                         while_pri = tmp;
 272                 else
 273                         break;
 274         }
 275
 276         if (while_pri)
 277                 ast_parseable_goto(chan, while_pri);
 278
 279         return 0;
 280 }
 281
 282 static int unload_module(void)
 283 {
 284         int res;
 285
 286         res = ast_unregister_application(start_app);
 287         res |= ast_unregister_application(stop_app);
 288         res |= ast_unregister_application(exit_app);
 289         res |= ast_unregister_application(continue_app);
 290
 291         return res;
 292 }
 293
 294 static int load_module(void)
 295 {
 296         int res;
 297
 298         res = ast_register_application(start_app, while_start_exec, start_synopsis, start_desc);
 299         res |= ast_register_application(stop_app, while_end_exec, stop_synopsis, stop_desc);
 300         res |= ast_register_application(exit_app, while_exit_exec, exit_synopsis, exit_desc);
 301         res |= ast_register_application(continue_app, while_continue_exec, continue_synopsis, continue_desc);
 302
 303         return res;
 304 }
 305
 306 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "While Loops and Conditional Execution");