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