app_disa.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2005, Digium, Inc.
 *
 *
 * Made only slightly more sane by Mark Spencer <[email protected]>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 *
 * \brief DISA -- Direct Inward System Access Application
 *
 * \author Jim Dixon <[email protected]>
 *
 * \ingroup applications
 */

/*** MODULEINFO
   <use type="module">app_cdr</use>
   <support_level>core</support_level>
 ***/

#include "asterisk.h"

#include <math.h>
#include <sys/time.h>

#include "asterisk/lock.h"
#include "asterisk/file.h"
#include "asterisk/channel.h"
#include "asterisk/app.h"
#include "asterisk/indications.h"
#include "asterisk/pbx.h"
#include "asterisk/module.h"
#include "asterisk/translate.h"
#include "asterisk/ulaw.h"
#include "asterisk/callerid.h"
#include "asterisk/stringfields.h"

/*** DOCUMENTATION
   <application name="DISA" language="en_US">
      <synopsis>
         Direct Inward System Access.
      </synopsis>
      <syntax>
         <parameter name="passcode|filename" required="true">
            <para>If you need to present a DISA dialtone without entering a password,
            simply set <replaceable>passcode</replaceable> to <literal>no-password</literal></para>
            <para>You may specified a <replaceable>filename</replaceable> instead of a
            <replaceable>passcode</replaceable>, this filename must contain individual passcodes</para>
         </parameter>
         <parameter name="context">
            <para>Specifies the dialplan context in which the user-entered extension
            will be matched. If no context is specified, the DISA application defaults
            to the <literal>disa</literal> context. Presumably a normal system will have a special
            context set up for DISA use with some or a lot of restrictions.</para>
         </parameter>
         <parameter name="cid">
            <para>Specifies a new (different) callerid to be used for this call.</para>
         </parameter>
         <parameter name="mailbox" argsep="@">
            <para>Will cause a stutter-dialtone (indication <emphasis>dialrecall</emphasis>)
            to be used, if the specified mailbox contains any new messages.</para>
            <argument name="mailbox" required="true" />
            <argument name="context" required="false" />
         </parameter>
         <parameter name="options">
            <optionlist>
               <option name="n">
                  <para>The DISA application will not answer initially.</para>
               </option>
               <option name="p">
                  <para>The extension entered will be considered complete when a <literal>#</literal>
                  is entered.</para>
               </option>
            </optionlist>
         </parameter>
      </syntax>
      <description>
         <para>The DISA, Direct Inward System Access, application allows someone from
         outside the telephone switch (PBX) to obtain an <emphasis>internal</emphasis> system
         dialtone and to place calls from it as if they were placing a call from
         within the switch.
         DISA plays a dialtone. The user enters their numeric passcode, followed by
         the pound sign <literal>#</literal>. If the passcode is correct, the user is then given
         system dialtone within <replaceable>context</replaceable> on which a call may be placed.
         If the user enters an invalid extension and extension <literal>i</literal> exists in the specified
         <replaceable>context</replaceable>, it will be used.
         </para>
         <para>Be aware that using this may compromise the security of your PBX.</para>
         <para>The arguments to this application (in <filename>extensions.conf</filename>) allow either
         specification of a single global <replaceable>passcode</replaceable> (that everyone uses), or
         individual passcodes contained in a file (<replaceable>filename</replaceable>).</para>
         <para>The file that contains the passcodes (if used) allows a complete
         specification of all of the same arguments available on the command
         line, with the sole exception of the options. The file may contain blank
         lines, or comments starting with <literal>#</literal> or <literal>;</literal>.</para>
      </description>
      <see-also>
         <ref type="application">Authenticate</ref>
         <ref type="application">VMAuthenticate</ref>
      </see-also>
   </application>
 ***/
static const char app[] = "DISA";

enum {
   NOANSWER_FLAG = (1 << 0),
   POUND_TO_END_FLAG = (1 << 1),
};

AST_APP_OPTIONS(app_opts, {
   AST_APP_OPTION('n', NOANSWER_FLAG),
   AST_APP_OPTION('p', POUND_TO_END_FLAG),
});

static void play_dialtone(struct ast_channel *chan, char *mailbox)
{
   struct ast_tone_zone_sound *ts = NULL;

   if (ast_app_has_voicemail(mailbox, NULL)) {
      ts = ast_get_indication_tone(ast_channel_zone(chan), "dialrecall");
   } else {
      ts = ast_get_indication_tone(ast_channel_zone(chan), "dial");
   }

   if (ts) {
      ast_playtones_start(chan, 0, ts->data, 0);
      ts = ast_tone_zone_sound_unref(ts);
   } else {
      ast_tonepair_start(chan, 350, 440, 0, 0);
   }
}

static int disa_exec(struct ast_channel *chan, const char *data)
{
   int i = 0, j, k = 0, did_ignore = 0, special_noanswer = 0;
   int firstdigittimeout = (ast_channel_pbx(chan) ? ast_channel_pbx(chan)->rtimeoutms : 20000);
   int digittimeout = (ast_channel_pbx(chan) ? ast_channel_pbx(chan)->dtimeoutms : 10000);
   struct ast_flags flags;
   char *tmp, exten[AST_MAX_EXTENSION] = "", acctcode[20]="";
   char pwline[256];
   char ourcidname[256],ourcidnum[256];
   struct ast_frame *f;
   struct timeval lastdigittime;
   int res;
   FILE *fp;
   AST_DECLARE_APP_ARGS(args,
      AST_APP_ARG(passcode);
      AST_APP_ARG(context);
      AST_APP_ARG(cid);
      AST_APP_ARG(mailbox);
      AST_APP_ARG(options);
   );

   if (ast_strlen_zero(data)) {
      ast_log(LOG_WARNING, "DISA requires an argument (passcode/passcode file)\n");
      return -1;
   }

   ast_debug(1, "Digittimeout: %d\n", digittimeout);
   ast_debug(1, "Responsetimeout: %d\n", firstdigittimeout);

   tmp = ast_strdupa(data);

   AST_STANDARD_APP_ARGS(args, tmp);

   if (ast_strlen_zero(args.context))
      args.context = "disa";
   if (ast_strlen_zero(args.mailbox))
      args.mailbox = "";
   if (!ast_strlen_zero(args.options)) {
      ast_app_parse_options(app_opts, &flags, NULL, args.options);
   } else {
      /* Coverity - This uninit_use should be ignored since this macro initializes the flags */
      ast_clear_flag(&flags, AST_FLAGS_ALL);
   }


   ast_debug(1, "Mailbox: %s\n",args.mailbox);

   if (!ast_test_flag(&flags, NOANSWER_FLAG)) {
      if (ast_channel_state(chan) != AST_STATE_UP) {
         /* answer */
         ast_answer(chan);
      }
   } else special_noanswer = 1;

   ast_debug(1, "Context: %s\n",args.context);

   if (!strcasecmp(args.passcode, "no-password")) {
      k |= 1; /* We have the password */
      ast_debug(1, "DISA no-password login success\n");
   }

   lastdigittime = ast_tvnow();

   play_dialtone(chan, args.mailbox);

   ast_channel_set_flag(chan, AST_FLAG_END_DTMF_ONLY);

   for (;;) {
        /* if outa time, give em reorder */
      if (ast_tvdiff_ms(ast_tvnow(), lastdigittime) > ((k&2) ? digittimeout : firstdigittimeout)) {
         ast_debug(1,"DISA %s entry timeout on chan %s\n",
            ((k&1) ? "extension" : "password"),ast_channel_name(chan));
         break;
      }

      if ((res = ast_waitfor(chan, -1)) < 0) {
         ast_debug(1, "Waitfor returned %d\n", res);
         continue;
      }

      if (!(f = ast_read(chan))) {
         ast_channel_clear_flag(chan, AST_FLAG_END_DTMF_ONLY);
         return -1;
      }

      if ((f->frametype == AST_FRAME_CONTROL) && (f->subclass.integer == AST_CONTROL_HANGUP)) {
         if (f->data.uint32)
            ast_channel_hangupcause_set(chan, f->data.uint32);
         ast_frfree(f);
         ast_channel_clear_flag(chan, AST_FLAG_END_DTMF_ONLY);
         return -1;
      }

      /* If the frame coming in is not DTMF, just drop it and continue */
      if (f->frametype != AST_FRAME_DTMF) {
         ast_frfree(f);
         continue;
      }

      j = f->subclass.integer;  /* save digit */
      ast_frfree(f);

      if (!i) {
         k |= 2; /* We have the first digit */
         ast_playtones_stop(chan);
      }

      lastdigittime = ast_tvnow();

      /* got a DTMF tone */
      if (i < AST_MAX_EXTENSION) { /* if still valid number of digits */
         if (!(k&1)) { /* if in password state */
            if (j == '#') { /* end of password */
                 /* see if this is an integer */
               if (sscanf(args.passcode,"%30d",&j) < 1) { /* nope, it must be a filename */
                  fp = fopen(args.passcode,"r");
                  if (!fp) {
                     ast_log(LOG_WARNING,"DISA password file %s not found on chan %s\n",args.passcode,ast_channel_name(chan));
                     ast_channel_clear_flag(chan, AST_FLAG_END_DTMF_ONLY);
                     return -1;
                  }
                  pwline[0] = 0;
                  while(fgets(pwline,sizeof(pwline) - 1,fp)) {
                     if (!pwline[0])
                        continue;
                     if (pwline[strlen(pwline) - 1] == '\n')
                        pwline[strlen(pwline) - 1] = 0;
                     if (!pwline[0])
                        continue;
                      /* skip comments */
                     if (pwline[0] == '#')
                        continue;
                     if (pwline[0] == ';')
                        continue;

                     AST_STANDARD_APP_ARGS(args, pwline);

                     ast_debug(1, "Mailbox: %s\n",args.mailbox);

                     /* password must be in valid format (numeric) */
                     if (sscanf(args.passcode,"%30d", &j) < 1)
                        continue;
                      /* if we got it */
                     if (!strcmp(exten,args.passcode)) {
                        if (ast_strlen_zero(args.context))
                           args.context = "disa";
                        if (ast_strlen_zero(args.mailbox))
                           args.mailbox = "";
                        break;
                     }
                  }
                  fclose(fp);
               }
               /* compare the two */
               if (strcmp(exten,args.passcode)) {
                  ast_log(LOG_WARNING,"DISA on chan %s got bad password %s\n",ast_channel_name(chan),exten);
                  goto reorder;

               }
                /* password good, set to dial state */
               ast_debug(1,"DISA on chan %s password is good\n",ast_channel_name(chan));
               play_dialtone(chan, args.mailbox);

               k|=1; /* In number mode */
               i = 0;  /* re-set buffer pointer */
               exten[sizeof(acctcode)] = 0;
               ast_copy_string(acctcode, exten, sizeof(acctcode));
               exten[0] = 0;
               ast_debug(1,"Successful DISA log-in on chan %s\n", ast_channel_name(chan));
               continue;
            }
         } else {
            if (j == '#') { /* end of extension .. maybe */
               if (i == 0
                  && (ast_matchmore_extension(chan, args.context, "#", 1,
                     S_COR(ast_channel_caller(chan)->id.number.valid, ast_channel_caller(chan)->id.number.str, NULL))
                     || ast_exists_extension(chan, args.context, "#", 1,
                        S_COR(ast_channel_caller(chan)->id.number.valid, ast_channel_caller(chan)->id.number.str, NULL))) ) {
                  /* Let the # be the part of, or the entire extension */
               } else {
                  break;
               }
            }
         }

         exten[i++] = j;  /* save digit */
         exten[i] = 0;
         if (!(k&1))
            continue; /* if getting password, continue doing it */
         /* if this exists */

         /* user wants end of number, remove # */
         if (ast_test_flag(&flags, POUND_TO_END_FLAG) && j == '#') {
            exten[--i] = 0;
            break;
         }

         if (ast_ignore_pattern(args.context, exten)) {
            play_dialtone(chan, "");
            did_ignore = 1;
         } else
            if (did_ignore) {
               ast_playtones_stop(chan);
               did_ignore = 0;
            }

         /* if can do some more, do it */
         if (!ast_matchmore_extension(chan, args.context, exten, 1,
            S_COR(ast_channel_caller(chan)->id.number.valid, ast_channel_caller(chan)->id.number.str, NULL))) {
            break;
         }
      }
   }

   ast_channel_clear_flag(chan, AST_FLAG_END_DTMF_ONLY);

   if (k == 3) {
      int recheck = 0;
      struct ast_app *app_reset_cdr;

      if (!ast_exists_extension(chan, args.context, exten, 1,
         S_COR(ast_channel_caller(chan)->id.number.valid, ast_channel_caller(chan)->id.number.str, NULL))) {
         pbx_builtin_setvar_helper(chan, "INVALID_EXTEN", exten);
         exten[0] = 'i';
         exten[1] = '\0';
         recheck = 1;
      }
      if (!recheck
         || ast_exists_extension(chan, args.context, exten, 1,
            S_COR(ast_channel_caller(chan)->id.number.valid, ast_channel_caller(chan)->id.number.str, NULL))) {
         ast_playtones_stop(chan);
         /* We're authenticated and have a target extension */
         if (!ast_strlen_zero(args.cid)) {
            ast_callerid_split(args.cid, ourcidname, sizeof(ourcidname), ourcidnum, sizeof(ourcidnum));
            ast_set_callerid(chan, ourcidnum, ourcidname, ourcidnum);
         }

         if (!ast_strlen_zero(acctcode)) {
            ast_channel_lock(chan);
            ast_channel_accountcode_set(chan, acctcode);
            ast_channel_unlock(chan);
         }

         app_reset_cdr = pbx_findapp("ResetCDR");
         if (app_reset_cdr) {
            pbx_exec(chan, app_reset_cdr, special_noanswer ? "" : "e");
         } else {
            ast_log(AST_LOG_NOTICE, "ResetCDR application not found; CDR will not be reset\n");
         }
         ast_explicit_goto(chan, args.context, exten, 1);
         return 0;
      }
   }

   /* Received invalid, but no "i" extension exists in the given context */

reorder:
   /* Play congestion for a bit */
   ast_indicate(chan, AST_CONTROL_CONGESTION);
   ast_safe_sleep(chan, 10*1000);

   ast_playtones_stop(chan);

   return -1;
}

static int unload_module(void)
{
   return ast_unregister_application(app);
}

static int load_module(void)
{
   return ast_register_application_xml(app, disa_exec) ?
      AST_MODULE_LOAD_DECLINE : AST_MODULE_LOAD_SUCCESS;
}

AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "DISA (Direct Inward System Access) Application");