Thu Jul 9 13:40:18 2009

Asterisk developer's documentation


app_disa.c

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00001 /*
00002  * Asterisk -- An open source telephony toolkit.
00003  *
00004  * Copyright (C) 1999 - 2005, Digium, Inc.
00005  *
00006  *
00007  * Made only slightly more sane by Mark Spencer <markster@digium.com>
00008  *
00009  * See http://www.asterisk.org for more information about
00010  * the Asterisk project. Please do not directly contact
00011  * any of the maintainers of this project for assistance;
00012  * the project provides a web site, mailing lists and IRC
00013  * channels for your use.
00014  *
00015  * This program is free software, distributed under the terms of
00016  * the GNU General Public License Version 2. See the LICENSE file
00017  * at the top of the source tree.
00018  */
00019 
00020 /*! \file
00021  *
00022  * \brief DISA -- Direct Inward System Access Application
00023  *
00024  * \author Jim Dixon <jim@lambdatel.com>
00025  *
00026  * \ingroup applications
00027  */
00028 
00029 #include "asterisk.h"
00030 
00031 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 168564 $")
00032 
00033 #include <math.h>
00034 #include <sys/time.h>
00035 
00036 #include "asterisk/lock.h"
00037 #include "asterisk/file.h"
00038 #include "asterisk/channel.h"
00039 #include "asterisk/app.h"
00040 #include "asterisk/indications.h"
00041 #include "asterisk/pbx.h"
00042 #include "asterisk/module.h"
00043 #include "asterisk/translate.h"
00044 #include "asterisk/ulaw.h"
00045 #include "asterisk/callerid.h"
00046 #include "asterisk/stringfields.h"
00047 
00048 static char *app = "DISA";
00049 
00050 static char *synopsis = "DISA (Direct Inward System Access)";
00051 
00052 static char *descrip =
00053 "DISA(<numeric passcode>[,<context>[,<cid>[,mailbox[,options]]]]) or\n"
00054 "DISA(<filename>[,,,,options])\n"
00055 "The DISA, Direct Inward System Access, application allows someone from \n"
00056 "outside the telephone switch (PBX) to obtain an \"internal\" system \n"
00057 "dialtone and to place calls from it as if they were placing a call from \n"
00058 "within the switch.\n"
00059 "DISA plays a dialtone. The user enters their numeric passcode, followed by\n"
00060 "the pound sign (#). If the passcode is correct, the user is then given\n"
00061 "system dialtone within <context> on which a call may be placed. If the user\n"
00062 "enters an invalid extension and extension \"i\" exists in the specified\n"
00063 "context, it will be used.\n"
00064 "\n"
00065 "If you need to present a DISA dialtone without entering a password, simply\n"
00066 "set <passcode> to \"no-password\".\n"
00067 "\n"
00068 "Be aware that using this may compromise the security of your PBX.\n"
00069 "\n"
00070 "The arguments to this application (in extensions.conf) allow either\n"
00071 "specification of a single global passcode (that everyone uses), or\n"
00072 "individual passcodes contained in a file.\n"
00073 "\n"
00074 "The file that contains the passcodes (if used) allows a complete\n"
00075 "specification of all of the same arguments available on the command\n"
00076 "line, with the sole exception of the options. The file may contain blank\n"
00077 "lines, or comments starting with \"#\" or \";\".\n"
00078 "\n"
00079 "<context> specifies the dialplan context in which the user-entered extension\n"
00080 "will be matched. If no context is specified, the DISA application defaults\n"
00081 "the context to \"disa\". Presumably a normal system will have a special\n"
00082 "context set up for DISA use with some or a lot of restrictions.\n"
00083 "\n"
00084 "<cid> specifies a new (different) callerid to be used for this call.\n"
00085 "\n"
00086 "<mailbox[@context]> will cause a stutter-dialtone (indication \"dialrecall\")\n"
00087 "to be used, if the specified mailbox contains any new messages.\n"
00088 "\n"
00089 "The following options are available:\n"
00090 "  n - the DISA application will not answer initially.\n"
00091 "  p - the extension entered will be considered complete when a '#' is entered.\n";
00092 
00093 enum {
00094    NOANSWER_FLAG = (1 << 0),
00095    POUND_TO_END_FLAG = (1 << 1),
00096 } option_flags;
00097 
00098 AST_APP_OPTIONS(app_opts, {
00099    AST_APP_OPTION('n', NOANSWER_FLAG),
00100    AST_APP_OPTION('p', POUND_TO_END_FLAG),
00101 });
00102 
00103 static void play_dialtone(struct ast_channel *chan, char *mailbox)
00104 {
00105    const struct tone_zone_sound *ts = NULL;
00106    if(ast_app_has_voicemail(mailbox, NULL))
00107       ts = ast_get_indication_tone(chan->zone, "dialrecall");
00108    else
00109       ts = ast_get_indication_tone(chan->zone, "dial");
00110    if (ts)
00111       ast_playtones_start(chan, 0, ts->data, 0);
00112    else
00113       ast_tonepair_start(chan, 350, 440, 0, 0);
00114 }
00115 
00116 static int disa_exec(struct ast_channel *chan, void *data)
00117 {
00118    int i = 0, j, k = 0, did_ignore = 0, special_noanswer = 0;
00119    int firstdigittimeout = (chan->pbx ? chan->pbx->rtimeout * 1000 : 20000);
00120    int digittimeout = (chan->pbx ? chan->pbx->dtimeout * 1000 : 10000);
00121    struct ast_flags flags;
00122    char *tmp, exten[AST_MAX_EXTENSION] = "", acctcode[20]="";
00123    char pwline[256];
00124    char ourcidname[256],ourcidnum[256];
00125    struct ast_frame *f;
00126    struct timeval lastdigittime;
00127    int res;
00128    FILE *fp;
00129    AST_DECLARE_APP_ARGS(args,
00130       AST_APP_ARG(passcode);
00131       AST_APP_ARG(context);
00132       AST_APP_ARG(cid);
00133       AST_APP_ARG(mailbox);
00134       AST_APP_ARG(options);
00135    );
00136 
00137    if (ast_strlen_zero(data)) {
00138       ast_log(LOG_WARNING, "DISA requires an argument (passcode/passcode file)\n");
00139       return -1;
00140    }
00141 
00142    ast_debug(1, "Digittimeout: %d\n", digittimeout);
00143    ast_debug(1, "Responsetimeout: %d\n", firstdigittimeout);
00144 
00145    tmp = ast_strdupa(data);
00146 
00147    AST_STANDARD_APP_ARGS(args, tmp);
00148 
00149    if (ast_strlen_zero(args.context))
00150       args.context = "disa";
00151    if (ast_strlen_zero(args.mailbox))
00152       args.mailbox = "";
00153    if (!ast_strlen_zero(args.options))
00154       ast_app_parse_options(app_opts, &flags, NULL, args.options);
00155 
00156    ast_debug(1, "Mailbox: %s\n",args.mailbox);
00157 
00158    if (!ast_test_flag(&flags, NOANSWER_FLAG)) {
00159       if (chan->_state != AST_STATE_UP) {
00160          /* answer */
00161          ast_answer(chan);
00162       }
00163    } else
00164       special_noanswer = 1;
00165 
00166    ast_debug(1, "Context: %s\n",args.context);
00167 
00168    if (!strcasecmp(args.passcode, "no-password")) {
00169       k |= 1; /* We have the password */
00170       ast_debug(1, "DISA no-password login success\n");
00171    }
00172 
00173    lastdigittime = ast_tvnow();
00174 
00175    play_dialtone(chan, args.mailbox);
00176 
00177    ast_set_flag(chan, AST_FLAG_END_DTMF_ONLY);
00178 
00179    for (;;) {
00180         /* if outa time, give em reorder */
00181       if (ast_tvdiff_ms(ast_tvnow(), lastdigittime) > ((k&2) ? digittimeout : firstdigittimeout)) {
00182          ast_debug(1,"DISA %s entry timeout on chan %s\n",
00183             ((k&1) ? "extension" : "password"),chan->name);
00184          break;
00185       }
00186 
00187       if ((res = ast_waitfor(chan, -1) < 0)) {
00188          ast_debug(1, "Waitfor returned %d\n", res);
00189          continue;
00190       }
00191 
00192       if (!(f = ast_read(chan))) {
00193          ast_clear_flag(chan, AST_FLAG_END_DTMF_ONLY);
00194          return -1;
00195       }
00196 
00197       if ((f->frametype == AST_FRAME_CONTROL) && (f->subclass == AST_CONTROL_HANGUP)) {
00198          ast_frfree(f);
00199          ast_clear_flag(chan, AST_FLAG_END_DTMF_ONLY);
00200          return -1;
00201       }
00202 
00203       /* If the frame coming in is not DTMF, just drop it and continue */
00204       if (f->frametype != AST_FRAME_DTMF) {
00205          ast_frfree(f);
00206          continue;
00207       }
00208 
00209       j = f->subclass;  /* save digit */
00210       ast_frfree(f);
00211 
00212       if (!i) {
00213          k |= 2; /* We have the first digit */
00214          ast_playtones_stop(chan);
00215       }
00216 
00217       lastdigittime = ast_tvnow();
00218 
00219       /* got a DTMF tone */
00220       if (i < AST_MAX_EXTENSION) { /* if still valid number of digits */
00221          if (!(k&1)) { /* if in password state */
00222             if (j == '#') { /* end of password */
00223                  /* see if this is an integer */
00224                if (sscanf(args.passcode,"%d",&j) < 1) { /* nope, it must be a filename */
00225                   fp = fopen(args.passcode,"r");
00226                   if (!fp) {
00227                      ast_log(LOG_WARNING,"DISA password file %s not found on chan %s\n",args.passcode,chan->name);
00228                      ast_clear_flag(chan, AST_FLAG_END_DTMF_ONLY);
00229                      return -1;
00230                   }
00231                   pwline[0] = 0;
00232                   while(fgets(pwline,sizeof(pwline) - 1,fp)) {
00233                      if (!pwline[0])
00234                         continue;
00235                      if (pwline[strlen(pwline) - 1] == '\n')
00236                         pwline[strlen(pwline) - 1] = 0;
00237                      if (!pwline[0])
00238                         continue;
00239                       /* skip comments */
00240                      if (pwline[0] == '#')
00241                         continue;
00242                      if (pwline[0] == ';')
00243                         continue;
00244 
00245                      AST_STANDARD_APP_ARGS(args, pwline);
00246 
00247                      ast_debug(1, "Mailbox: %s\n",args.mailbox);
00248 
00249                      /* password must be in valid format (numeric) */
00250                      if (sscanf(args.passcode,"%d", &j) < 1)
00251                         continue;
00252                       /* if we got it */
00253                      if (!strcmp(exten,args.passcode)) {
00254                         if (ast_strlen_zero(args.context))
00255                            args.context = "disa";
00256                         if (ast_strlen_zero(args.mailbox))
00257                            args.mailbox = "";
00258                         break;
00259                      }
00260                   }
00261                   fclose(fp);
00262                }
00263                /* compare the two */
00264                if (strcmp(exten,args.passcode)) {
00265                   ast_log(LOG_WARNING,"DISA on chan %s got bad password %s\n",chan->name,exten);
00266                   goto reorder;
00267 
00268                }
00269                 /* password good, set to dial state */
00270                ast_debug(1,"DISA on chan %s password is good\n",chan->name);
00271                play_dialtone(chan, args.mailbox);
00272 
00273                k|=1; /* In number mode */
00274                i = 0;  /* re-set buffer pointer */
00275                exten[sizeof(acctcode)] = 0;
00276                ast_copy_string(acctcode, exten, sizeof(acctcode));
00277                exten[0] = 0;
00278                ast_debug(1,"Successful DISA log-in on chan %s\n", chan->name);
00279                continue;
00280             }
00281          } else {
00282             if (j == '#') { /* end of extension .. maybe */
00283                if (i == 0 && 
00284                      (ast_matchmore_extension(chan, args.context, "#", 1, chan->cid.cid_num) ||
00285                       ast_exists_extension(chan, args.context, "#", 1, chan->cid.cid_num)) ) {
00286                   /* Let the # be the part of, or the entire extension */
00287                } else {
00288                   break;
00289                }
00290             }
00291          }
00292 
00293          exten[i++] = j;  /* save digit */
00294          exten[i] = 0;
00295          if (!(k&1))
00296             continue; /* if getting password, continue doing it */
00297          /* if this exists */
00298 
00299          /* user wants end of number, remove # */
00300          if (ast_test_flag(&flags, POUND_TO_END_FLAG) && j == '#') {
00301             exten[--i] = 0;
00302             break;
00303          }
00304 
00305          if (ast_ignore_pattern(args.context, exten)) {
00306             play_dialtone(chan, "");
00307             did_ignore = 1;
00308          } else
00309             if (did_ignore) {
00310                ast_playtones_stop(chan);
00311                did_ignore = 0;
00312             }
00313 
00314          /* if can do some more, do it */
00315          if (!ast_matchmore_extension(chan,args.context,exten,1, chan->cid.cid_num)) {
00316             break;
00317          }
00318       }
00319    }
00320 
00321    ast_clear_flag(chan, AST_FLAG_END_DTMF_ONLY);
00322 
00323    if (k == 3) {
00324       int recheck = 0;
00325       struct ast_flags flags = { AST_CDR_FLAG_POSTED };
00326 
00327       if (!ast_exists_extension(chan, args.context, exten, 1, chan->cid.cid_num)) {
00328          pbx_builtin_setvar_helper(chan, "INVALID_EXTEN", exten);
00329          exten[0] = 'i';
00330          exten[1] = '\0';
00331          recheck = 1;
00332       }
00333       if (!recheck || ast_exists_extension(chan, args.context, exten, 1, chan->cid.cid_num)) {
00334          ast_playtones_stop(chan);
00335          /* We're authenticated and have a target extension */
00336          if (!ast_strlen_zero(args.cid)) {
00337             ast_callerid_split(args.cid, ourcidname, sizeof(ourcidname), ourcidnum, sizeof(ourcidnum));
00338             ast_set_callerid(chan, ourcidnum, ourcidname, ourcidnum);
00339          }
00340 
00341          if (!ast_strlen_zero(acctcode))
00342             ast_string_field_set(chan, accountcode, acctcode);
00343 
00344          if (special_noanswer) flags.flags = 0;
00345          ast_cdr_reset(chan->cdr, &flags);
00346          ast_explicit_goto(chan, args.context, exten, 1);
00347          return 0;
00348       }
00349    }
00350 
00351    /* Received invalid, but no "i" extension exists in the given context */
00352 
00353 reorder:
00354    /* Play congestion for a bit */
00355    ast_indicate(chan, AST_CONTROL_CONGESTION);
00356    ast_safe_sleep(chan, 10*1000);
00357 
00358    ast_playtones_stop(chan);
00359 
00360    return -1;
00361 }
00362 
00363 static int unload_module(void)
00364 {
00365    return ast_unregister_application(app);
00366 }
00367 
00368 static int load_module(void)
00369 {
00370    return ast_register_application(app, disa_exec, synopsis, descrip);
00371 }
00372 
00373 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "DISA (Direct Inward System Access) Application");

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