chan_mobile.c

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2006, Digium, Inc.
 *
 * 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 Bluetooth Mobile Device channel driver
 *
 * \author Dave Bowerman <david.bowerman@gmail.com>
 *
 * \ingroup channel_drivers
 */

/*** MODULEINFO
	<depend>bluetooth</depend>
	<defaultenabled>no</defaultenabled>
 ***/

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision$")

#include <pthread.h>
#include <signal.h>

#include <bluetooth/bluetooth.h>
#include <bluetooth/hci.h>
#include <bluetooth/hci_lib.h>
#include <bluetooth/sdp.h>
#include <bluetooth/sdp_lib.h>
#include <bluetooth/rfcomm.h>
#include <bluetooth/sco.h>
#include <bluetooth/l2cap.h>

#include "asterisk/compat.h"
#include "asterisk/lock.h"
#include "asterisk/channel.h"
#include "asterisk/config.h"
#include "asterisk/logger.h"
#include "asterisk/module.h"
#include "asterisk/pbx.h"
#include "asterisk/options.h"
#include "asterisk/utils.h"
#include "asterisk/linkedlists.h"
#include "asterisk/cli.h"
#include "asterisk/devicestate.h"
#include "asterisk/causes.h"
#include "asterisk/dsp.h"
#include "asterisk/app.h"
#include "asterisk/manager.h"
#include "asterisk/io.h"

#define MBL_CONFIG "mobile.conf"

#define DEVICE_FRAME_SIZE 48
#define DEVICE_FRAME_FORMAT AST_FORMAT_SLINEAR
#define CHANNEL_FRAME_SIZE 320

static int prefformat = DEVICE_FRAME_FORMAT;

static int discovery_interval = 60;			/* The device discovery interval, default 60 seconds. */
static pthread_t discovery_thread = AST_PTHREADT_NULL;	/* The discovery thread */
static sdp_session_t *sdp_session;

AST_MUTEX_DEFINE_STATIC(unload_mutex);
static int unloading_flag = 0;
static inline int check_unloading(void);
static inline void set_unloading(void);

enum mbl_type {
	MBL_TYPE_PHONE,
	MBL_TYPE_HEADSET
};

struct adapter_pvt {
	int dev_id;					/* device id */
	int hci_socket;					/* device descriptor */
	char id[31];					/* the 'name' from mobile.conf */
	bdaddr_t addr;					/* adddress of adapter */
	unsigned int inuse:1;				/* are we in use ? */
	unsigned int alignment_detection:1;		/* do alignment detection on this adpater? */
	struct io_context *io;				/*!< io context for audio connections */
	struct io_context *accept_io;			/*!< io context for sco listener */
	int *sco_id;					/*!< the io context id of the sco listener socket */
	int sco_socket;					/*!< sco listener socket */
	pthread_t sco_listener_thread;			/*!< sco listener thread */
	AST_LIST_ENTRY(adapter_pvt) entry;
};

static AST_RWLIST_HEAD_STATIC(adapters, adapter_pvt);

struct msg_queue_entry;
struct hfp_pvt;
struct mbl_pvt {
	struct ast_channel *owner;			/* Channel we belong to, possibly NULL */
	struct ast_frame fr;				/* "null" frame */
	ast_mutex_t lock;				/*!< pvt lock */
	/*! queue for messages we are expecting */
	AST_LIST_HEAD_NOLOCK(msg_queue, msg_queue_entry) msg_queue;
	enum mbl_type type;				/* Phone or Headset */
	char id[31];					/* The id from mobile.conf */
	int group;					/* group number for group dialling */
	bdaddr_t addr;					/* address of device */
	struct adapter_pvt *adapter;			/* the adapter we use */
	char context[AST_MAX_CONTEXT];			/* the context for incoming calls */
	struct hfp_pvt *hfp;				/*!< hfp pvt */
	int rfcomm_port;				/* rfcomm port number */
	int rfcomm_socket;				/* rfcomm socket descriptor */
	char rfcomm_buf[256];
	char io_buf[CHANNEL_FRAME_SIZE + AST_FRIENDLY_OFFSET];
	struct ast_smoother *smoother;			/* our smoother, for making 48 byte frames */
	int sco_socket;					/* sco socket descriptor */
	pthread_t monitor_thread;			/* monitor thread handle */
	int timeout;					/*!< used to set the timeout for rfcomm data (may be used in the future) */
	unsigned int no_callsetup:1;
	unsigned int has_sms:1;
	unsigned int do_alignment_detection:1;
	unsigned int alignment_detection_triggered:1;
	unsigned int blackberry:1;
	short alignment_samples[4];
	int alignment_count;
	int ring_sched_id;
	struct ast_dsp *dsp;
	struct sched_context *sched;

	/* flags */
	unsigned int outgoing:1;	/*!< outgoing call */
	unsigned int incoming:1;	/*!< incoming call */
	unsigned int outgoing_sms:1;	/*!< outgoing sms */
	unsigned int incoming_sms:1;	/*!< outgoing sms */
	unsigned int needcallerid:1;	/*!< we need callerid */
	unsigned int needchup:1;	/*!< we need to send a chup */
	unsigned int needring:1;	/*!< we need to send a RING */
	unsigned int answered:1;	/*!< we sent/recieved an answer */
	unsigned int connected:1;	/*!< do we have an rfcomm connection to a device */

	AST_LIST_ENTRY(mbl_pvt) entry;
};

static AST_RWLIST_HEAD_STATIC(devices, mbl_pvt);

static int handle_response_ok(struct mbl_pvt *pvt, char *buf);
static int handle_response_error(struct mbl_pvt *pvt, char *buf);
static int handle_response_ciev(struct mbl_pvt *pvt, char *buf);
static int handle_response_clip(struct mbl_pvt *pvt, char *buf);
static int handle_response_ring(struct mbl_pvt *pvt, char *buf);
static int handle_response_cmti(struct mbl_pvt *pvt, char *buf);
static int handle_response_cmgr(struct mbl_pvt *pvt, char *buf);
static int handle_sms_prompt(struct mbl_pvt *pvt, char *buf);

/* CLI stuff */
static char *handle_cli_mobile_show_devices(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a);
static char *handle_cli_mobile_search(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a);
static char *handle_cli_mobile_rfcomm(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a);

static struct ast_cli_entry mbl_cli[] = {
	AST_CLI_DEFINE(handle_cli_mobile_show_devices, "Show Bluetooth Cell / Mobile devices"),
	AST_CLI_DEFINE(handle_cli_mobile_search,       "Search for Bluetooth Cell / Mobile devices"),
	AST_CLI_DEFINE(handle_cli_mobile_rfcomm,       "Send commands to the rfcomm port for debugging"),
};

/* App stuff */
static char *app_mblstatus = "MobileStatus";
static char *mblstatus_synopsis = "MobileStatus(Device,Variable)";
static char *mblstatus_desc =
"MobileStatus(Device,Variable)\n"
"  Device - Id of mobile device from mobile.conf\n"
"  Variable - Variable to store status in will be 1-3.\n"
"             In order, Disconnected, Connected & Free, Connected & Busy.\n";

static char *app_mblsendsms = "MobileSendSMS";
static char *mblsendsms_synopsis = "MobileSendSMS(Device,Dest,Message)";
static char *mblsendsms_desc =
"MobileSendSms(Device,Dest,Message)\n"
"  Device - Id of device from mobile.conf\n"
"  Dest - destination\n"
"  Message - text of the message\n";

static struct ast_channel *mbl_new(int state, struct mbl_pvt *pvt, char *cid_num,
		const struct ast_channel *requestor);
static struct ast_channel *mbl_request(const char *type, int format,
		const struct ast_channel *requestor, void *data, int *cause);
static int mbl_call(struct ast_channel *ast, char *dest, int timeout);
static int mbl_hangup(struct ast_channel *ast);
static int mbl_answer(struct ast_channel *ast);
static int mbl_digit_end(struct ast_channel *ast, char digit, unsigned int duration);
static struct ast_frame *mbl_read(struct ast_channel *ast);
static int mbl_write(struct ast_channel *ast, struct ast_frame *frame);
static int mbl_fixup(struct ast_channel *oldchan, struct ast_channel *newchan);
static int mbl_devicestate(void *data);

static void do_alignment_detection(struct mbl_pvt *pvt, char *buf, int buflen);

static int mbl_queue_control(struct mbl_pvt *pvt, enum ast_control_frame_type control);
static int mbl_queue_hangup(struct mbl_pvt *pvt);
static int mbl_ast_hangup(struct mbl_pvt *pvt);

static int rfcomm_connect(bdaddr_t src, bdaddr_t dst, int remote_channel);
static int rfcomm_write(int rsock, char *buf);
static int rfcomm_write_full(int rsock, char *buf, size_t count);
static int rfcomm_wait(int rsock, int *ms);
static ssize_t rfcomm_read(int rsock, char *buf, size_t count);

static int sco_connect(bdaddr_t src, bdaddr_t dst);
static int sco_write(int s, char *buf, int len);
static int sco_accept(int *id, int fd, short events, void *data);
static int sco_bind(struct adapter_pvt *adapter);

static void *do_sco_listen(void *data);
static int sdp_search(char *addr, int profile);

static int headset_send_ring(const void *data);

/*
 * bluetooth handsfree profile helpers
 */

#define HFP_HF_ECNR	(1 << 0)
#define HFP_HF_CW	(1 << 1)
#define HFP_HF_CID	(1 << 2)
#define HFP_HF_VOICE	(1 << 3)
#define HFP_HF_VOLUME	(1 << 4)
#define HFP_HF_STATUS	(1 << 5)
#define HFP_HF_CONTROL	(1 << 6)

#define HFP_AG_CW	(1 << 0)
#define HFP_AG_ECNR	(1 << 1)
#define HFP_AG_VOICE	(1 << 2)
#define HFP_AG_RING	(1 << 3)
#define HFP_AG_TAG	(1 << 4)
#define HFP_AG_REJECT	(1 << 5)
#define HFP_AG_STATUS	(1 << 6)
#define HFP_AG_CONTROL	(1 << 7)
#define HFP_AG_ERRORS	(1 << 8)

#define HFP_CIND_UNKNOWN	-1
#define HFP_CIND_NONE		0
#define HFP_CIND_SERVICE	1
#define HFP_CIND_CALL		2
#define HFP_CIND_CALLSETUP	3
#define HFP_CIND_CALLHELD	4
#define HFP_CIND_SIGNAL		5
#define HFP_CIND_ROAM		6
#define HFP_CIND_BATTCHG	7

/* call indicator values */
#define HFP_CIND_CALL_NONE	0
#define HFP_CIND_CALL_ACTIVE	1

/* callsetup indicator values */
#define HFP_CIND_CALLSETUP_NONE		0
#define HFP_CIND_CALLSETUP_INCOMING	1
#define HFP_CIND_CALLSETUP_OUTGOING	2
#define HFP_CIND_CALLSETUP_ALERTING	3

/*!
 * \brief This struct holds HFP features that we support.
 */
struct hfp_hf {
	int ecnr:1;	/*!< echo-cancel/noise reduction */
	int cw:1;	/*!< call waiting and three way calling */
	int cid:1;	/*!< cli presentation (callier id) */
	int voice:1;	/*!< voice recognition activation */
	int volume:1;	/*!< remote volume control */
	int status:1;	/*!< enhanced call status */
	int control:1;	/*!< enhanced call control*/
};

/*!
 * \brief This struct holds HFP features the AG supports.
 */
struct hfp_ag {
	int cw:1;	/*!< three way calling */
	int ecnr:1;	/*!< echo-cancel/noise reduction */
	int voice:1;	/*!< voice recognition */
	int ring:1;	/*!< in band ring tone capability */
	int tag:1;	/*!< attach a number to a voice tag */
	int reject:1;	/*!< ability to reject a call */
	int status:1;	/*!< enhanced call status */
	int control:1;	/*!< enhanced call control*/
	int errors:1;	/*!< extended error result codes*/
};

/*!
 * \brief This struct holds mappings for indications.
 */
struct hfp_cind {
	int service;	/*!< whether we have service or not */
	int call;	/*!< call state */
	int callsetup;	/*!< bluetooth call setup indications */
	int callheld;	/*!< bluetooth call hold indications */
	int signal;	/*!< signal strength */
	int roam;	/*!< roaming indicator */
	int battchg;	/*!< battery charge indicator */
};


/*!
 * \brief This struct holds state information about the current hfp connection.
 */
struct hfp_pvt {
	struct mbl_pvt *owner;		/*!< the mbl_pvt struct that owns this struct */
	int initialized:1;		/*!< whether a service level connection exists or not */
	int nocallsetup:1;		/*!< whether we detected a callsetup indicator */
	struct hfp_ag brsf;		/*!< the supported feature set of the AG */
	int cind_index[16];		/*!< the cind/ciev index to name mapping for this AG */
	int cind_state[16];		/*!< the cind/ciev state for this AG */
	struct hfp_cind cind_map;	/*!< the cind name to index mapping for this AG */
	int rsock;			/*!< our rfcomm socket */
	int rport;			/*!< our rfcomm port */
};


/* Our supported features.
 * we only support caller id
 */
static struct hfp_hf hfp_our_brsf = {
	.ecnr = 0,
	.cw = 0,
	.cid = 1,
	.voice = 0,
	.volume = 0,
	.status = 0,
	.control = 0,
};


static int hfp_parse_ciev(struct hfp_pvt *hfp, char *buf, int *value);
static char *hfp_parse_clip(struct hfp_pvt *hfp, char *buf);
static int hfp_parse_cmti(struct hfp_pvt *hfp, char *buf);
static int hfp_parse_cmgr(struct hfp_pvt *hfp, char *buf, char **from_number, char **text);
static int hfp_parse_brsf(struct hfp_pvt *hfp, const char *buf);
static int hfp_parse_cind(struct hfp_pvt *hfp, char *buf);
static int hfp_parse_cind_test(struct hfp_pvt *hfp, char *buf);

static int hfp_brsf2int(struct hfp_hf *hf);
static struct hfp_ag *hfp_int2brsf(int brsf, struct hfp_ag *ag);

static int hfp_send_brsf(struct hfp_pvt *hfp, struct hfp_hf *brsf);
static int hfp_send_cind(struct hfp_pvt *hfp);
static int hfp_send_cind_test(struct hfp_pvt *hfp);
static int hfp_send_cmer(struct hfp_pvt *hfp, int status);
static int hfp_send_clip(struct hfp_pvt *hfp, int status);
static int hfp_send_vgs(struct hfp_pvt *hfp, int value);

#if 0
static int hfp_send_vgm(struct hfp_pvt *hfp, int value);
#endif
static int hfp_send_dtmf(struct hfp_pvt *hfp, char digit);
static int hfp_send_cmgf(struct hfp_pvt *hfp, int mode);
static int hfp_send_cnmi(struct hfp_pvt *hfp);
static int hfp_send_cmgr(struct hfp_pvt *hfp, int index);
static int hfp_send_cmgs(struct hfp_pvt *hfp, const char *number);
static int hfp_send_sms_text(struct hfp_pvt *hfp, const char *message);
static int hfp_send_chup(struct hfp_pvt *hfp);
static int hfp_send_atd(struct hfp_pvt *hfp, const char *number);
static int hfp_send_ata(struct hfp_pvt *hfp);

/*
 * bluetooth headset profile helpers
 */
static int hsp_send_ok(int rsock);
static int hsp_send_error(int rsock);
static int hsp_send_vgs(int rsock, int gain);
static int hsp_send_vgm(int rsock, int gain);
static int hsp_send_ring(int rsock);


/*
 * Hayes AT command helpers
 */
typedef enum {
	/* errors */
	AT_PARSE_ERROR = -2,
	AT_READ_ERROR = -1,
	AT_UNKNOWN = 0,
	/* at responses */
	AT_OK,
	AT_ERROR,
	AT_RING,
	AT_BRSF,
	AT_CIND,
	AT_CIEV,
	AT_CLIP,
	AT_CMTI,
	AT_CMGR,
	AT_SMS_PROMPT,
	AT_CMS_ERROR,
	/* at commands */
	AT_A,
	AT_D,
	AT_CHUP,
	AT_CKPD,
	AT_CMGS,
	AT_VGM,
	AT_VGS,
	AT_VTS,
	AT_CMGF,
	AT_CNMI,
	AT_CMER,
	AT_CIND_TEST,
} at_message_t;

static int at_match_prefix(char *buf, char *prefix);
static at_message_t at_read_full(int rsock, char *buf, size_t count);
static inline const char *at_msg2str(at_message_t msg);

struct msg_queue_entry {
	at_message_t expected;
	at_message_t response_to;
	void *data;

	AST_LIST_ENTRY(msg_queue_entry) entry;
};

static int msg_queue_push(struct mbl_pvt *pvt, at_message_t expect, at_message_t response_to);
static int msg_queue_push_data(struct mbl_pvt *pvt, at_message_t expect, at_message_t response_to, void *data);
static struct msg_queue_entry *msg_queue_pop(struct mbl_pvt *pvt);
static void msg_queue_free_and_pop(struct mbl_pvt *pvt);
static void msg_queue_flush(struct mbl_pvt *pvt);
static struct msg_queue_entry *msg_queue_head(struct mbl_pvt *pvt);

/*
 * channel stuff
 */

static const struct ast_channel_tech mbl_tech = {
	.type = "Mobile",
	.description = "Bluetooth Mobile Device Channel Driver",
	.capabilities = AST_FORMAT_SLINEAR,
	.requester = mbl_request,
	.call = mbl_call,
	.hangup = mbl_hangup,
	.answer = mbl_answer,
	.send_digit_end = mbl_digit_end,
	.read = mbl_read,
	.write = mbl_write,
	.fixup = mbl_fixup,
	.devicestate = mbl_devicestate
};

/* CLI Commands implementation */

static char *handle_cli_mobile_show_devices(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
	struct mbl_pvt *pvt;
	char bdaddr[18];
	char group[6];

#define FORMAT1 "%-15.15s %-17.17s %-5.5s %-15.15s %-9.9s %-5.5s %-3.3s\n"

	switch (cmd) {
	case CLI_INIT:
		e->command = "mobile show devices";
		e->usage =
			"Usage: mobile show devices\n"
			"       Shows the state of Bluetooth Cell / Mobile devices.\n";
		return NULL;
	case CLI_GENERATE:
		return NULL;
	}

	if (a->argc != 3)
		return CLI_SHOWUSAGE;

	ast_cli(a->fd, FORMAT1, "ID", "Address", "Group", "Adapter", "Connected", "State", "SMS");
	AST_RWLIST_RDLOCK(&devices);
	AST_RWLIST_TRAVERSE(&devices, pvt, entry) {
		ast_mutex_lock(&pvt->lock);
		ba2str(&pvt->addr, bdaddr);
		snprintf(group, sizeof(group), "%d", pvt->group);
		ast_cli(a->fd, FORMAT1,
				pvt->id,
				bdaddr,
				group,
				pvt->adapter->id,
				pvt->connected ? "Yes" : "No",
				(!pvt->connected) ? "None" : (pvt->owner) ? "Busy" : (pvt->outgoing_sms || pvt->incoming_sms) ? "SMS" : "Free",
				(pvt->has_sms) ? "Yes" : "No"
		       );
		ast_mutex_unlock(&pvt->lock);
	}
	AST_RWLIST_UNLOCK(&devices);

#undef FORMAT1

	return CLI_SUCCESS;
}

static char *handle_cli_mobile_search(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
	struct adapter_pvt *adapter;
	inquiry_info *ii = NULL;
	int max_rsp, num_rsp;
	int len, flags;
	int i, phport, hsport;
	char addr[19] = {0};
	char name[31] = {0};

#define FORMAT1 "%-17.17s %-30.30s %-6.6s %-7.7s %-4.4s\n"
#define FORMAT2 "%-17.17s %-30.30s %-6.6s %-7.7s %d\n"

	switch (cmd) {
	case CLI_INIT:
		e->command = "mobile search";
		e->usage =
			"Usage: mobile search\n"
			"       Searches for Bluetooth Cell / Mobile devices in range.\n";
		return NULL;
	case CLI_GENERATE:
		return NULL;
	}

	if (a->argc != 2)
		return CLI_SHOWUSAGE;

	/* find a free adapter */
	AST_RWLIST_RDLOCK(&adapters);
	AST_RWLIST_TRAVERSE(&adapters, adapter, entry) {
		if (!adapter->inuse)
			break;
	}
	AST_RWLIST_UNLOCK(&adapters);

	if (!adapter) {
		ast_cli(a->fd, "All Bluetooth adapters are in use at this time.\n");
		return CLI_SUCCESS;
	}

	len  = 8;
	max_rsp = 255;
	flags = IREQ_CACHE_FLUSH;

	ii = alloca(max_rsp * sizeof(inquiry_info));
	num_rsp = hci_inquiry(adapter->dev_id, len, max_rsp, NULL, &ii, flags);
	if (num_rsp > 0) {
		ast_cli(a->fd, FORMAT1, "Address", "Name", "Usable", "Type", "Port");
		for (i = 0; i < num_rsp; i++) {
			ba2str(&(ii + i)->bdaddr, addr);
			name[0] = 0x00;
			if (hci_read_remote_name(adapter->hci_socket, &(ii + i)->bdaddr, sizeof(name) - 1, name, 0) < 0)
				strcpy(name, "[unknown]");
			phport = sdp_search(addr, HANDSFREE_AGW_PROFILE_ID);
			if (!phport)
				hsport = sdp_search(addr, HEADSET_PROFILE_ID);
			else
				hsport = 0;
			ast_cli(a->fd, FORMAT2, addr, name, (phport > 0 || hsport > 0) ? "Yes" : "No",
				(phport > 0) ? "Phone" : "Headset", (phport > 0) ? phport : hsport);
		}
	} else
		ast_cli(a->fd, "No Bluetooth Cell / Mobile devices found.\n");

#undef FORMAT1
#undef FORMAT2

	return CLI_SUCCESS;
}

static char *handle_cli_mobile_rfcomm(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
	char buf[128];
	struct mbl_pvt *pvt = NULL;

	switch (cmd) {
	case CLI_INIT:
		e->command = "mobile rfcomm";
		e->usage =
			"Usage: mobile rfcomm <device ID> <command>\n"
			"       Send <command> to the rfcomm port on the device\n"
			"       with the specified <device ID>.\n";
		return NULL;
	case CLI_GENERATE:
		return NULL;
	}

	if (a->argc != 4)
		return CLI_SHOWUSAGE;

	AST_RWLIST_RDLOCK(&devices);
	AST_RWLIST_TRAVERSE(&devices, pvt, entry) {
		if (!strcmp(pvt->id, a->argv[2]))
			break;
	}
	AST_RWLIST_UNLOCK(&devices);

	if (!pvt) {
		ast_cli(a->fd, "Device %s not found.\n", a->argv[2]);
		goto e_return;
	}

	ast_mutex_lock(&pvt->lock);
	if (!pvt->connected) {
		ast_cli(a->fd, "Device %s not connected.\n", a->argv[2]);
		goto e_unlock_pvt;
	}

	snprintf(buf, sizeof(buf), "%s\r", a->argv[3]);
	rfcomm_write(pvt->rfcomm_socket, buf);
	msg_queue_push(pvt, AT_OK, AT_UNKNOWN);

e_unlock_pvt:
	ast_mutex_unlock(&pvt->lock);
e_return:
	return CLI_SUCCESS;
}

/*

	Dialplan applications implementation

*/

static int mbl_status_exec(struct ast_channel *ast, const char *data)
{

	struct mbl_pvt *pvt;
	char *parse;
	int stat;
	char status[2];

	AST_DECLARE_APP_ARGS(args,
		AST_APP_ARG(device);
		AST_APP_ARG(variable);
	);

	if (ast_strlen_zero(data))
		return -1;

	parse = ast_strdupa(data);

	AST_STANDARD_APP_ARGS(args, parse);

	if (ast_strlen_zero(args.device) || ast_strlen_zero(args.variable))
		return -1;

	stat = 1;

	AST_RWLIST_RDLOCK(&devices);
	AST_RWLIST_TRAVERSE(&devices, pvt, entry) {
		if (!strcmp(pvt->id, args.device))
			break;
	}
	AST_RWLIST_UNLOCK(&devices);

	if (pvt) {
		ast_mutex_lock(&pvt->lock);
		if (pvt->connected)
			stat = 2;
		if (pvt->owner)
			stat = 3;
		ast_mutex_unlock(&pvt->lock);
	}

	snprintf(status, sizeof(status), "%d", stat);
	pbx_builtin_setvar_helper(ast, args.variable, status);

	return 0;

}

static int mbl_sendsms_exec(struct ast_channel *ast, const char *data)
{

	struct mbl_pvt *pvt;
	char *parse, *message;

	AST_DECLARE_APP_ARGS(args,
		AST_APP_ARG(device);
		AST_APP_ARG(dest);
		AST_APP_ARG(message);
	);

	if (ast_strlen_zero(data))
		return -1;

	parse = ast_strdupa(data);

	AST_STANDARD_APP_ARGS(args, parse);

	if (ast_strlen_zero(args.device)) {
		ast_log(LOG_ERROR,"NULL device for message -- SMS will not be sent.\n");
		return -1;
	}

	if (ast_strlen_zero(args.dest)) {
		ast_log(LOG_ERROR,"NULL destination for message -- SMS will not be sent.\n");
		return -1;
	}

	if (ast_strlen_zero(args.message)) {
		ast_log(LOG_ERROR,"NULL Message to be sent -- SMS will not be sent.\n");
		return -1;
	}

	AST_RWLIST_RDLOCK(&devices);
	AST_RWLIST_TRAVERSE(&devices, pvt, entry) {
		if (!strcmp(pvt->id, args.device))
			break;
	}
	AST_RWLIST_UNLOCK(&devices);

	if (!pvt) {
		ast_log(LOG_ERROR,"Bluetooth device %s wasn't found in the list -- SMS will not be sent.\n", args.device);
		goto e_return;
	}

	ast_mutex_lock(&pvt->lock);
	if (!pvt->connected) {
		ast_log(LOG_ERROR,"Bluetooth device %s wasn't connected -- SMS will not be sent.\n", args.device);
		goto e_unlock_pvt;
	}

	if (!pvt->has_sms) {
		ast_log(LOG_ERROR,"Bluetooth device %s doesn't handle SMS -- SMS will not be sent.\n", args.device);
		goto e_unlock_pvt;
	}

	message = ast_strdup(args.message);

	if (hfp_send_cmgs(pvt->hfp, args.dest)
		|| msg_queue_push_data(pvt, AT_SMS_PROMPT, AT_CMGS, message)) {

		ast_log(LOG_ERROR, "[%s] problem sending SMS message\n", pvt->id);
		goto e_free_message;
	}

	ast_mutex_unlock(&pvt->lock);

	return 0;

e_free_message:
	ast_free(message);
e_unlock_pvt:
	ast_mutex_unlock(&pvt->lock);
e_return:
	return -1;
}

/*

	Channel Driver callbacks

*/

static struct ast_channel *mbl_new(int state, struct mbl_pvt *pvt, char *cid_num,
		const struct ast_channel *requestor)
{

	struct ast_channel *chn;

	pvt->answered = 0;
	pvt->alignment_count = 0;
	pvt->alignment_detection_triggered = 0;
	if (pvt->adapter->alignment_detection)
		pvt->do_alignment_detection = 1;
	else
		pvt->do_alignment_detection = 0;

	ast_smoother_reset(pvt->smoother, DEVICE_FRAME_SIZE);
	ast_dsp_digitreset(pvt->dsp);

	chn = ast_channel_alloc(1, state, cid_num, pvt->id, 0, 0, pvt->context,
			requestor ? requestor->linkedid : "", 0,
			"Mobile/%s-%04lx", pvt->id, ast_random() & 0xffff);
	if (!chn) {
		goto e_return;
	}

	chn->tech = &mbl_tech;
	chn->nativeformats = prefformat;
	chn->rawreadformat = prefformat;
	chn->rawwriteformat = prefformat;
	chn->writeformat = prefformat;
	chn->readformat = prefformat;
	chn->tech_pvt = pvt;

	if (state == AST_STATE_RING)
		chn->rings = 1;

	ast_string_field_set(chn, language, "en");
	pvt->owner = chn;

	if (pvt->sco_socket != -1) {
		ast_channel_set_fd(chn, 0, pvt->sco_socket);
	}

	return chn;

e_return:
	return NULL;
}

static struct ast_channel *mbl_request(const char *type, int format,
		const struct ast_channel *requestor, void *data, int *cause)
{

	struct ast_channel *chn = NULL;
	struct mbl_pvt *pvt;
	char *dest_dev = NULL;
	char *dest_num = NULL;
	int oldformat, group = -1;

	if (!data) {
		ast_log(LOG_WARNING, "Channel requested with no data\n");
		*cause = AST_CAUSE_INCOMPATIBLE_DESTINATION;
		return NULL;
	}

	oldformat = format;
	format &= (AST_FORMAT_SLINEAR);
	if (!format) {
		ast_log(LOG_WARNING, "Asked to get a channel of unsupported format '%d'\n", oldformat);
		*cause = AST_CAUSE_FACILITY_NOT_IMPLEMENTED;
		return NULL;
	}

	dest_dev = ast_strdupa((char *)data);

	dest_num = strchr(dest_dev, '/');
	if (dest_num)
		*dest_num++ = 0x00;

	if (((dest_dev[0] == 'g') || (dest_dev[0] == 'G')) && ((dest_dev[1] >= '0') && (dest_dev[1] <= '9'))) {
		group = atoi(&dest_dev[1]);
	}

	/* Find requested device and make sure it's connected. */
	AST_RWLIST_RDLOCK(&devices);
	AST_RWLIST_TRAVERSE(&devices, pvt, entry) {
		if (group > -1 && pvt->group == group && pvt->connected && !pvt->owner) {
			break;
		} else if (!strcmp(pvt->id, dest_dev)) {
			break;
		}
	}
	AST_RWLIST_UNLOCK(&devices);
	if (!pvt || !pvt->connected || pvt->owner) {
		ast_log(LOG_WARNING, "Request to call on device %s which is not connected / already in use.\n", dest_dev);
		*cause = AST_CAUSE_REQUESTED_CHAN_UNAVAIL;
		return NULL;
	}

	if ((pvt->type == MBL_TYPE_PHONE) && !dest_num) {
		ast_log(LOG_WARNING, "Can't determine destination number.\n");
		*cause = AST_CAUSE_INCOMPATIBLE_DESTINATION;
		return NULL;
	}

	ast_mutex_lock(&pvt->lock);
	chn = mbl_new(AST_STATE_DOWN, pvt, NULL, requestor);
	ast_mutex_unlock(&pvt->lock);
	if (!chn) {
		ast_log(LOG_WARNING, "Unable to allocate channel structure.\n");
		*cause = AST_CAUSE_REQUESTED_CHAN_UNAVAIL;
		return NULL;
	}

	return chn;

}

static int mbl_call(struct ast_channel *ast, char *dest, int timeout)
{

	struct mbl_pvt *pvt;
	char *dest_dev = NULL;
	char *dest_num = NULL;

	dest_dev = ast_strdupa((char *)dest);

	pvt = ast->tech_pvt;

	if (pvt->type == MBL_TYPE_PHONE) {
		dest_num = strchr(dest_dev, '/');
		if (!dest_num) {
			ast_log(LOG_WARNING, "Cant determine destination number.\n");
			return -1;
		}
		*dest_num++ = 0x00;
	}

	if ((ast->_state != AST_STATE_DOWN) && (ast->_state != AST_STATE_RESERVED)) {
		ast_log(LOG_WARNING, "mbl_call called on %s, neither down nor reserved\n", ast->name);
		return -1;
	}

	ast_debug(1, "Calling %s on %s\n", dest, ast->name);

	ast_mutex_lock(&pvt->lock);
	if (pvt->type == MBL_TYPE_PHONE) {
		if (hfp_send_atd(pvt->hfp, dest_num)) {
			ast_mutex_unlock(&pvt->lock);
			ast_log(LOG_ERROR, "error sending ATD command on %s\n", pvt->id);
			return -1;
		}
		pvt->needchup = 1;
		msg_queue_push(pvt, AT_OK, AT_D);
	} else {
		if (hsp_send_ring(pvt->rfcomm_socket)) {
			ast_log(LOG_ERROR, "[%s] error ringing device\n", pvt->id);
			ast_mutex_unlock(&pvt->lock);
			return -1;
		}

		if ((pvt->ring_sched_id = ast_sched_add(pvt->sched, 6000, headset_send_ring, pvt)) == -1) {
			ast_log(LOG_ERROR, "[%s] error ringing device\n", pvt->id);
			ast_mutex_unlock(&pvt->lock);
			return -1;
		}

		pvt->outgoing = 1;
		pvt->needring = 1;
	}
	ast_mutex_unlock(&pvt->lock);

	return 0;

}

static int mbl_hangup(struct ast_channel *ast)
{

	struct mbl_pvt *pvt;

	if (!ast->tech_pvt) {
		ast_log(LOG_WARNING, "Asked to hangup channel not connected\n");
		return 0;
	}
	pvt = ast->tech_pvt;

	ast_debug(1, "[%s] hanging up device\n", pvt->id);

	ast_mutex_lock(&pvt->lock);
	ast_channel_set_fd(ast, 0, -1);
	close(pvt->sco_socket);
	pvt->sco_socket = -1;

	if (pvt->needchup) {
		hfp_send_chup(pvt->hfp);
		msg_queue_push(pvt, AT_OK, AT_CHUP);
		pvt->needchup = 0;
	}

	pvt->outgoing = 0;
	pvt->incoming = 0;
	pvt->needring = 0;
	pvt->owner = NULL;
	ast->tech_pvt = NULL;

	ast_mutex_unlock(&pvt->lock);

	ast_setstate(ast, AST_STATE_DOWN);

	return 0;

}

static int mbl_answer(struct ast_channel *ast)
{

	struct mbl_pvt *pvt;

	pvt = ast->tech_pvt;

	if (pvt->type == MBL_TYPE_HEADSET)
		return 0;

	ast_mutex_lock(&pvt->lock);
	if (pvt->incoming) {
		hfp_send_ata(pvt->hfp);
		msg_queue_push(pvt, AT_OK, AT_A);
		pvt->answered = 1;
	}
	ast_mutex_unlock(&pvt->lock);

	return 0;

}

static int mbl_digit_end(struct ast_channel *ast, char digit, unsigned int duration)
{
	struct mbl_pvt *pvt = ast->tech_pvt;

	if (pvt->type == MBL_TYPE_HEADSET)
		return 0;