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 <markster@digium.com>
 *
 * 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 <jim@lambdatel.com>
 *
 * \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;
 
        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);
            }
 
            if (ast_pbx_exec_application(chan, "ResetCDR", special_noanswer ? "" : "e")) {
                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");