app_disa.c

/*
 * 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
 */
 
#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision$")

#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"

static char *app = "DISA";

static char *synopsis = "DISA (Direct Inward System Access)";

static char *descrip = 
"DISA(<numeric passcode>[,<context>[,<cid>[,mailbox[,options]]]]) or\n"
"DISA(<filename>[,,,,options])\n"
"The DISA, Direct Inward System Access, application allows someone from \n"
"outside the telephone switch (PBX) to obtain an \"internal\" system \n"
"dialtone and to place calls from it as if they were placing a call from \n"
"within the switch.\n"
"DISA plays a dialtone. The user enters their numeric passcode, followed by\n"
"the pound sign (#). If the passcode is correct, the user is then given\n"
"system dialtone within <context> on which a call may be placed. If the user\n"
"enters an invalid extension and extension \"i\" exists in the specified\n"
"context, it will be used.\n"
"\n"
"If you need to present a DISA dialtone without entering a password, simply\n"
"set <passcode> to \"no-password\".\n"
"\n"
"Be aware that using this may compromise the security of your PBX.\n"
"\n"
"The arguments to this application (in extensions.conf) allow either\n"
"specification of a single global passcode (that everyone uses), or\n"
"individual passcodes contained in a file.\n"
"\n"
"The file that contains the passcodes (if used) allows a complete\n"
"specification of all of the same arguments available on the command\n"
"line, with the sole exception of the options. The file may contain blank\n"
"lines, or comments starting with \"#\" or \";\".\n"
"\n"
"<context> specifies the dialplan context in which the user-entered extension\n"
"will be matched. If no context is specified, the DISA application defaults\n"
"the context to \"disa\". Presumably a normal system will have a special\n"
"context set up for DISA use with some or a lot of restrictions.\n"
"\n"
"<cid> specifies a new (different) callerid to be used for this call.\n"
"\n"
"<mailbox[@context]> will cause a stutter-dialtone (indication \"dialrecall\")\n"
"to be used, if the specified mailbox contains any new messages.\n"
"\n"
"The following options are available:\n"
"  n - the DISA application will not answer initially.\n"
"  p - the extension entered will be considered complete when a '#' is entered.\n";

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

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)
{
	const struct ind_tone_zone_sound *ts = NULL;
	if(ast_app_has_voicemail(mailbox, NULL))
		ts = ast_get_indication_tone(chan->zone, "dialrecall");
	else
		ts = ast_get_indication_tone(chan->zone, "dial");
	if (ts)
		ast_playtones_start(chan, 0, ts->data, 0);
	else
		ast_tonepair_start(chan, 350, 440, 0, 0);
}

static int disa_exec(struct ast_channel *chan, void *data)
{
	int i = 0, j, k = 0, did_ignore = 0, special_noanswer = 0;
	int firstdigittimeout = (chan->pbx ? chan->pbx->rtimeout * 1000 : 20000);
	int digittimeout = (chan->pbx ? chan->pbx->dtimeout * 1000 : 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);

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

	if (!ast_test_flag(&flags, NOANSWER_FLAG)) {
		if (chan->_state != 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_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"),chan->name);
			break;
		}
		
		if ((res = ast_waitfor(chan, -1) < 0)) {
			ast_debug(1, "Waitfor returned %d\n", res);
			continue;
		}

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

		if ((f->frametype == AST_FRAME_CONTROL) && (f->subclass == AST_CONTROL_HANGUP)) {
			ast_frfree(f);
			ast_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;  /* 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,"%d",&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,chan->name);
							ast_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,"%d", &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",chan->name,exten);
						goto reorder;

					}
					 /* password good, set to dial state */
					ast_debug(1,"DISA on chan %s password is good\n",chan->name);
					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", chan->name);
					continue;
				}
			} else {
				if (j == '#') { /* end of extension */
					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, chan->cid.cid_num)) {
				break;
			}
		}
	}

	ast_clear_flag(chan, AST_FLAG_END_DTMF_ONLY);

	if (k == 3) {
		int recheck = 0;
		struct ast_flags flags = { AST_CDR_FLAG_POSTED };

		if (!ast_exists_extension(chan, args.context, exten, 1, chan->cid.cid_num)) {
			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, chan->cid.cid_num)) {
			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_string_field_set(chan, accountcode, acctcode);

			if (special_noanswer) flags.flags = 0;
			ast_cdr_reset(chan->cdr, &flags);
			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(app, disa_exec, synopsis, descrip);
}

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