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 <stdlib.h>
  33 #include <stdio.h>
  34 #include <string.h>
  35 #include <unistd.h>
  36
  37 #include "asterisk/file.h"
  38 #include "asterisk/logger.h"
  39 #include "asterisk/channel.h"
  40 #include "asterisk/utils.h"
  41 #include "asterisk/config.h"
  42 #include "asterisk/pbx.h"
  43 #include "asterisk/module.h"
  44 #include "asterisk/lock.h"
  45 #include "asterisk/options.h"
  46
  47 #define ALL_DONE(u,ret) {ast_module_user_remove(u); return ret;}
  48
  49
  50 static char *start_app = "While";
  51 static char *start_desc =
  52 "Usage:  While(<expr>)\n"
  53 "Start a While Loop.  Execution will return to this point when\n"
  54 "EndWhile is called until expr is no longer true.\n";
  55
  56 static char *start_synopsis = "Start a while loop";
  57
  58
  59 static char *stop_app = "EndWhile";
  60 static char *stop_desc =
  61 "Usage:  EndWhile()\n"
  62 "Return to the previous called While\n";
  63
  64 static char *stop_synopsis = "End a while loop";
  65
  66 static char *exit_app = "ExitWhile";
  67 static char *exit_desc =
  68 "Usage:  ExitWhile()\n"
  69 "Exits a While loop, whether or not the conditional has been satisfied.\n";
  70 static char *exit_synopsis = "End a While loop";
  71
  72 static char *continue_app = "ContinueWhile";
  73 static char *continue_desc =
  74 "Usage:  ContinueWhile()\n"
  75 "Returns to the top of the while loop and re-evaluates the conditional.\n";
  76 static char *continue_synopsis = "Restart a While loop";
  77
  78 #define VAR_SIZE 64
  79
  80
  81 static const char *get_index(struct ast_channel *chan, const char *prefix, int index) {
  82         char varname[VAR_SIZE];
  83
  84         snprintf(varname, VAR_SIZE, "%s_%d", prefix, index);
  85         return pbx_builtin_getvar_helper(chan, varname);
  86 }
  87
  88 static struct ast_exten *find_matching_priority(struct ast_context *c, const char *exten, int priority, const char *callerid)
  89 {
  90         struct ast_exten *e;
  91         struct ast_include *i;
  92         struct ast_context *c2;
  93
  94         for (e=ast_walk_context_extensions(c, NULL); e; e=ast_walk_context_extensions(c, e)) {
  95                 if (ast_extension_match(ast_get_extension_name(e), exten)) {
  96                         int needmatch = ast_get_extension_matchcid(e);
  97                         if ((needmatch && ast_extension_match(ast_get_extension_cidmatch(e), callerid)) ||
  98                                 (!needmatch)) {
  99                                 /* This is the matching extension we want */
 100                                 struct ast_exten *p;
 101                                 for (p=ast_walk_extension_priorities(e, NULL); p; p=ast_walk_extension_priorities(e, p)) {
 102                                         if (priority != ast_get_extension_priority(p))
 103                                                 continue;
 104                                         return p;
 105                                 }
 106                         }
 107                 }
 108         }
 109
 110         /* No match; run through includes */
 111         for (i=ast_walk_context_includes(c, NULL); i; i=ast_walk_context_includes(c, i)) {
 112                 for (c2=ast_walk_contexts(NULL); c2; c2=ast_walk_contexts(c2)) {
 113                         if (!strcmp(ast_get_context_name(c2), ast_get_include_name(i))) {
 114                                 e = find_matching_priority(c2, exten, priority, callerid);
 115                                 if (e)
 116                                         return e;
 117                         }
 118                 }
 119         }
 120         return NULL;
 121 }
 122
 123 static int find_matching_endwhile(struct ast_channel *chan)
 124 {
 125         struct ast_context *c;
 126         int res=-1;
 127
 128         if (ast_lock_contexts()) {
 129                 ast_log(LOG_ERROR, "Failed to lock contexts list\n");
 130                 return -1;
 131         }
 132
 133         for (c=ast_walk_contexts(NULL); c; c=ast_walk_contexts(c)) {
 134                 struct ast_exten *e;
 135
 136                 if (!ast_lock_context(c)) {
 137                         if (!strcmp(ast_get_context_name(c), chan->context)) {
 138                                 /* This is the matching context we want */
 139                                 int cur_priority = chan->priority + 1, level=1;
 140
 141                                 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)) {
 142                                         if (!strcasecmp(ast_get_extension_app(e), "WHILE")) {
 143                                                 level++;
 144                                         } else if (!strcasecmp(ast_get_extension_app(e), "ENDWHILE")) {
 145                                                 level--;
 146                                         }
 147
 148                                         if (level == 0) {
 149                                                 res = cur_priority;
 150                                                 break;
 151                                         }
 152                                 }
 153                         }
 154                         ast_unlock_context(c);
 155                         if (res > 0) {
 156                                 break;
 157                         }
 158                 }
 159         }
 160         ast_unlock_contexts();
 161         return res;
 162 }
 163
 164 static int _while_exec(struct ast_channel *chan, void *data, int end)
 165 {
 166         int res=0;
 167         struct ast_module_user *u;
 168         const char *while_pri = NULL;
 169         char *my_name = NULL;
 170         const char *condition = NULL, *label = NULL;
 171         char varname[VAR_SIZE], end_varname[VAR_SIZE];
 172         const char *prefix = "WHILE";
 173         size_t size=0;
 174         int used_index_i = -1, x=0;
 175         char used_index[VAR_SIZE] = "0", new_index[VAR_SIZE] = "0";
 176
 177         if (!chan) {
 178                 /* huh ? */
 179                 return -1;
 180         }
 181
 182         u = ast_module_user_add(chan);
 183
 184         /* dont want run away loops if the chan isn't even up
 185            this is up for debate since it slows things down a tad ......
 186         */
 187         if (ast_waitfordigit(chan,1) < 0)
 188                 ALL_DONE(u,-1);
 189
 190
 191         for (x=0;;x++) {
 192                 if (get_index(chan, prefix, x)) {
 193                         used_index_i = x;
 194                 } else
 195                         break;
 196         }
 197
 198         snprintf(used_index, VAR_SIZE, "%d", used_index_i);
 199         snprintf(new_index, VAR_SIZE, "%d", used_index_i + 1);
 200
 201         if (!end)
 202                 condition = ast_strdupa(data);
 203
 204         size = strlen(chan->context) + strlen(chan->exten) + 32;
 205         my_name = alloca(size);
 206         memset(my_name, 0, size);
 207         snprintf(my_name, size, "%s_%s_%d", chan->context, chan->exten, chan->priority);
 208
 209         if (ast_strlen_zero(label)) {
 210                 if (end)
 211                         label = used_index;
 212                 else if (!(label = pbx_builtin_getvar_helper(chan, my_name))) {
 213                         label = new_index;
 214                         pbx_builtin_setvar_helper(chan, my_name, label);
 215                 }
 216
 217         }
 218
 219         snprintf(varname, VAR_SIZE, "%s_%s", prefix, label);
 220         while_pri = pbx_builtin_getvar_helper(chan, varname);
 221
 222         if ((while_pri = pbx_builtin_getvar_helper(chan, varname)) && !end) {
 223                 snprintf(end_varname,VAR_SIZE,"END_%s",varname);
 224         }
 225
 226
 227         if ((!end && !pbx_checkcondition(condition)) || (end == 2)) {
 228                 /* Condition Met (clean up helper vars) */
 229                 const char *goto_str;
 230                 pbx_builtin_setvar_helper(chan, varname, NULL);
 231                 pbx_builtin_setvar_helper(chan, my_name, NULL);
 232                 snprintf(end_varname,VAR_SIZE,"END_%s",varname);
 233                 if ((goto_str=pbx_builtin_getvar_helper(chan, end_varname))) {
 234                         ast_parseable_goto(chan, goto_str);
 235                         pbx_builtin_setvar_helper(chan, end_varname, NULL);
 236                 } else {
 237                         int pri = find_matching_endwhile(chan);
 238                         if (pri > 0) {
 239                                 if (option_verbose > 2)
 240                                         ast_verbose(VERBOSE_PREFIX_3 "Jumping to priority %d\n", pri);
 241                                 chan->priority = pri;
 242                         } else {
 243                                 ast_log(LOG_WARNING, "Couldn't find matching EndWhile? (While at %s@%s priority %d)\n", chan->context, chan->exten, chan->priority);
 244                         }
 245                 }
 246                 ALL_DONE(u,res);
 247         }
 248
 249         if (!end && !while_pri) {
 250                 char *goto_str;
 251                 size = strlen(chan->context) + strlen(chan->exten) + 32;
 252                 goto_str = alloca(size);
 253                 memset(goto_str, 0, size);
 254                 snprintf(goto_str, size, "%s|%s|%d", chan->context, chan->exten, chan->priority);
 255                 pbx_builtin_setvar_helper(chan, varname, goto_str);
 256         }
 257
 258         else if (end && while_pri) {
 259                 /* END of loop */
 260                 snprintf(end_varname, VAR_SIZE, "END_%s", varname);
 261                 if (! pbx_builtin_getvar_helper(chan, end_varname)) {
 262                         char *goto_str;
 263                         size = strlen(chan->context) + strlen(chan->exten) + 32;
 264                         goto_str = alloca(size);
 265                         memset(goto_str, 0, size);
 266                         snprintf(goto_str, size, "%s|%s|%d", chan->context, chan->exten, chan->priority+1);
 267                         pbx_builtin_setvar_helper(chan, end_varname, goto_str);
 268                 }
 269                 ast_parseable_goto(chan, while_pri);
 270         }
 271
 272
 273
 274
 275         ALL_DONE(u, res);
 276 }
 277
 278 static int while_start_exec(struct ast_channel *chan, void *data) {
 279         return _while_exec(chan, data, 0);
 280 }
 281
 282 static int while_end_exec(struct ast_channel *chan, void *data) {
 283         return _while_exec(chan, data, 1);
 284 }
 285
 286 static int while_exit_exec(struct ast_channel *chan, void *data) {
 287         return _while_exec(chan, data, 2);
 288 }
 289
 290 static int while_continue_exec(struct ast_channel *chan, void *data)
 291 {
 292         int x;
 293         const char *prefix = "WHILE", *while_pri=NULL;
 294
 295         for (x = 0; ; x++) {
 296                 const char *tmp = get_index(chan, prefix, x);
 297                 if (tmp)
 298                         while_pri = tmp;
 299                 else
 300                         break;
 301         }
 302
 303         if (while_pri)
 304                 ast_parseable_goto(chan, while_pri);
 305
 306         return 0;
 307 }
 308
 309 static int unload_module(void)
 310 {
 311         int res;
 312
 313         res = ast_unregister_application(start_app);
 314         res |= ast_unregister_application(stop_app);
 315         res |= ast_unregister_application(exit_app);
 316         res |= ast_unregister_application(continue_app);
 317
 318         ast_module_user_hangup_all();
 319
 320         return res;
 321 }
 322
 323 static int load_module(void)
 324 {
 325         int res;
 326
 327         res = ast_register_application(start_app, while_start_exec, start_synopsis, start_desc);
 328         res |= ast_register_application(stop_app, while_end_exec, stop_synopsis, stop_desc);
 329         res |= ast_register_application(exit_app, while_exit_exec, exit_synopsis, exit_desc);
 330         res |= ast_register_application(continue_app, while_continue_exec, continue_synopsis, continue_desc);
 331
 332         return res;
 333 }
 334
 335 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "While Loops and Conditional Execution");