Wed Aug 18 22:33:41 2010

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: 220291 $")
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->rtimeoutms : 20000);
00120    int digittimeout = (chan->pbx ? chan->pbx->dtimeoutms : 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 special_noanswer = 1;
00164 
00165    ast_debug(1, "Context: %s\n",args.context);
00166 
00167    if (!strcasecmp(args.passcode, "no-password")) {
00168       k |= 1; /* We have the password */
00169       ast_debug(1, "DISA no-password login success\n");
00170    }
00171 
00172    lastdigittime = ast_tvnow();
00173 
00174    play_dialtone(chan, args.mailbox);
00175 
00176    ast_set_flag(chan, AST_FLAG_END_DTMF_ONLY);
00177 
00178    for (;;) {
00179         /* if outa time, give em reorder */
00180       if (ast_tvdiff_ms(ast_tvnow(), lastdigittime) > ((k&2) ? digittimeout : firstdigittimeout)) {
00181          ast_debug(1,"DISA %s entry timeout on chan %s\n",
00182             ((k&1) ? "extension" : "password"),chan->name);
00183          break;
00184       }
00185 
00186       if ((res = ast_waitfor(chan, -1) < 0)) {
00187          ast_debug(1, "Waitfor returned %d\n", res);
00188          continue;
00189       }
00190 
00191       if (!(f = ast_read(chan))) {
00192          ast_clear_flag(chan, AST_FLAG_END_DTMF_ONLY);
00193          return -1;
00194       }
00195 
00196       if ((f->frametype == AST_FRAME_CONTROL) && (f->subclass == AST_CONTROL_HANGUP)) {
00197          if (f->data.uint32)
00198             chan->hangupcause = f->data.uint32;
00199          ast_frfree(f);
00200          ast_clear_flag(chan, AST_FLAG_END_DTMF_ONLY);
00201          return -1;
00202       }
00203 
00204       /* If the frame coming in is not DTMF, just drop it and continue */
00205       if (f->frametype != AST_FRAME_DTMF) {
00206          ast_frfree(f);
00207          continue;
00208       }
00209 
00210       j = f->subclass;  /* save digit */
00211       ast_frfree(f);
00212 
00213       if (!i) {
00214          k |= 2; /* We have the first digit */
00215          ast_playtones_stop(chan);
00216       }
00217 
00218       lastdigittime = ast_tvnow();
00219 
00220       /* got a DTMF tone */
00221       if (i < AST_MAX_EXTENSION) { /* if still valid number of digits */
00222          if (!(k&1)) { /* if in password state */
00223             if (j == '#') { /* end of password */
00224                  /* see if this is an integer */
00225                if (sscanf(args.passcode,"%30d",&j) < 1) { /* nope, it must be a filename */
00226                   fp = fopen(args.passcode,"r");
00227                   if (!fp) {
00228                      ast_log(LOG_WARNING,"DISA password file %s not found on chan %s\n",args.passcode,chan->name);
00229                      ast_clear_flag(chan, AST_FLAG_END_DTMF_ONLY);
00230                      return -1;
00231                   }
00232                   pwline[0] = 0;
00233                   while(fgets(pwline,sizeof(pwline) - 1,fp)) {
00234                      if (!pwline[0])
00235                         continue;
00236                      if (pwline[strlen(pwline) - 1] == '\n')
00237                         pwline[strlen(pwline) - 1] = 0;
00238                      if (!pwline[0])
00239                         continue;
00240                       /* skip comments */
00241                      if (pwline[0] == '#')
00242                         continue;
00243                      if (pwline[0] == ';')
00244                         continue;
00245 
00246                      AST_STANDARD_APP_ARGS(args, pwline);
00247 
00248                      ast_debug(1, "Mailbox: %s\n",args.mailbox);
00249 
00250                      /* password must be in valid format (numeric) */
00251                      if (sscanf(args.passcode,"%30d", &j) < 1)
00252                         continue;
00253                       /* if we got it */
00254                      if (!strcmp(exten,args.passcode)) {
00255                         if (ast_strlen_zero(args.context))
00256                            args.context = "disa";
00257                         if (ast_strlen_zero(args.mailbox))
00258                            args.mailbox = "";
00259                         break;
00260                      }
00261                   }
00262                   fclose(fp);
00263                }
00264                /* compare the two */
00265                if (strcmp(exten,args.passcode)) {
00266                   ast_log(LOG_WARNING,"DISA on chan %s got bad password %s\n",chan->name,exten);
00267                   goto reorder;
00268 
00269                }
00270                 /* password good, set to dial state */
00271                ast_debug(1,"DISA on chan %s password is good\n",chan->name);
00272                play_dialtone(chan, args.mailbox);
00273 
00274                k|=1; /* In number mode */
00275                i = 0;  /* re-set buffer pointer */
00276                exten[sizeof(acctcode)] = 0;
00277                ast_copy_string(acctcode, exten, sizeof(acctcode));
00278                exten[0] = 0;
00279                ast_debug(1,"Successful DISA log-in on chan %s\n", chan->name);
00280                continue;
00281             }
00282          } else {
00283             if (j == '#') { /* end of extension .. maybe */
00284                if (i == 0 && 
00285                      (ast_matchmore_extension(chan, args.context, "#", 1, chan->cid.cid_num) ||
00286                       ast_exists_extension(chan, args.context, "#", 1, chan->cid.cid_num)) ) {
00287                   /* Let the # be the part of, or the entire extension */
00288                } else {
00289                   break;
00290                }
00291             }
00292          }
00293 
00294          exten[i++] = j;  /* save digit */
00295          exten[i] = 0;
00296          if (!(k&1))
00297             continue; /* if getting password, continue doing it */
00298          /* if this exists */
00299 
00300          /* user wants end of number, remove # */
00301          if (ast_test_flag(&flags, POUND_TO_END_FLAG) && j == '#') {
00302             exten[--i] = 0;
00303             break;
00304          }
00305 
00306          if (ast_ignore_pattern(args.context, exten)) {
00307             play_dialtone(chan, "");
00308             did_ignore = 1;
00309          } else
00310             if (did_ignore) {
00311                ast_playtones_stop(chan);
00312                did_ignore = 0;
00313             }
00314 
00315          /* if can do some more, do it */
00316          if (!ast_matchmore_extension(chan,args.context,exten,1, chan->cid.cid_num)) {
00317             break;
00318          }
00319       }
00320    }
00321 
00322    ast_clear_flag(chan, AST_FLAG_END_DTMF_ONLY);
00323 
00324    if (k == 3) {
00325       int recheck = 0;
00326       struct ast_flags cdr_flags = { AST_CDR_FLAG_POSTED };
00327 
00328       if (!ast_exists_extension(chan, args.context, exten, 1, chan->cid.cid_num)) {
00329          pbx_builtin_setvar_helper(chan, "INVALID_EXTEN", exten);
00330          exten[0] = 'i';
00331          exten[1] = '\0';
00332          recheck = 1;
00333       }
00334       if (!recheck || ast_exists_extension(chan, args.context, exten, 1, chan->cid.cid_num)) {
00335          ast_playtones_stop(chan);
00336          /* We're authenticated and have a target extension */
00337          if (!ast_strlen_zero(args.cid)) {
00338             ast_callerid_split(args.cid, ourcidname, sizeof(ourcidname), ourcidnum, sizeof(ourcidnum));
00339             ast_set_callerid(chan, ourcidnum, ourcidname, ourcidnum);
00340          }
00341 
00342          if (!ast_strlen_zero(acctcode))
00343             ast_string_field_set(chan, accountcode, acctcode);
00344 
00345          if (special_noanswer) cdr_flags.flags = 0;
00346          ast_cdr_reset(chan->cdr, &cdr_flags);
00347          ast_explicit_goto(chan, args.context, exten, 1);
00348          return 0;
00349       }
00350    }
00351 
00352    /* Received invalid, but no "i" extension exists in the given context */
00353 
00354 reorder:
00355    /* Play congestion for a bit */
00356    ast_indicate(chan, AST_CONTROL_CONGESTION);
00357    ast_safe_sleep(chan, 10*1000);
00358 
00359    ast_playtones_stop(chan);
00360 
00361    return -1;
00362 }
00363 
00364 static int unload_module(void)
00365 {
00366    return ast_unregister_application(app);
00367 }
00368 
00369 static int load_module(void)
00370 {
00371    return ast_register_application(app, disa_exec, synopsis, descrip) ?
00372       AST_MODULE_LOAD_DECLINE : AST_MODULE_LOAD_SUCCESS;
00373 }
00374 
00375 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "DISA (Direct Inward System Access) Application");

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