chan_zap.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 Zaptel Pseudo TDM interface 
 *
 * \author Mark Spencer <markster@digium.com>
 * 
 * Connects to the zaptel telephony library as well as 
 * libpri. Libpri is optional and needed only if you are
 * going to use ISDN connections.
 *
 * You need to install libraries before you attempt to compile
 * and install the zaptel channel.
 *
 * \par See also
 * \arg \ref Config_zap
 *
 * \ingroup channel_drivers
 *
 * \todo Decprecate the "musiconhold" configuration option in v1.5dev
 */

#include <stdio.h>
#include <string.h>
#ifdef __NetBSD__
#include <pthread.h>
#include <signal.h>
#else
#include <sys/signal.h>
#endif
#include <errno.h>
#include <stdlib.h>
#if !defined(SOLARIS) && !defined(__FreeBSD__)
#include <stdint.h>
#endif
#include <unistd.h>
#include <sys/ioctl.h>
#ifdef __linux__
#include <linux/zaptel.h>
#else
#include <zaptel.h>
#endif /* __linux__ */
#include <math.h>
#include <tonezone.h>
#include <ctype.h>
#ifdef ZAPATA_PRI
#include <libpri.h>
#ifndef PRI_KEYPAD_FACILITY_TX
#error "You need newer libpri"
#endif
#endif
#ifdef ZAPATA_R2
#include <libmfcr2.h>
#endif

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision$")

#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/file.h"
#include "asterisk/ulaw.h"
#include "asterisk/alaw.h"
#include "asterisk/callerid.h"
#include "asterisk/adsi.h"
#include "asterisk/cli.h"
#include "asterisk/cdr.h"
#include "asterisk/features.h"
#include "asterisk/musiconhold.h"
#include "asterisk/say.h"
#include "asterisk/tdd.h"
#include "asterisk/app.h"
#include "asterisk/dsp.h"
#include "asterisk/astdb.h"
#include "asterisk/manager.h"
#include "asterisk/causes.h"
#include "asterisk/term.h"
#include "asterisk/utils.h"
#include "asterisk/transcap.h"
#include "asterisk/stringfields.h"
#ifdef WITH_SMDI
#include "asterisk/smdi.h"
#include "asterisk/astobj.h"
#define SMDI_MD_WAIT_TIMEOUT 1500 /* 1.5 seconds */
#endif

#if !defined(ZT_SIG_EM_E1) || (defined(ZAPATA_PRI) && !defined(ZT_SIG_HARDHDLC))
#error "Your zaptel is too old.  please update"
#endif

#ifndef ZT_TONEDETECT
/* Work around older code with no tone detect */
#define ZT_EVENT_DTMFDOWN 0
#define ZT_EVENT_DTMFUP 0
#endif

/* define this to send PRI user-user information elements */
#undef SUPPORT_USERUSER

/*! 
 * \note Define ZHONE_HACK to cause us to go off hook and then back on hook when
 * the user hangs up to reset the state machine so ring works properly.
 * This is used to be able to support kewlstart by putting the zhone in
 * groundstart mode since their forward disconnect supervision is entirely
 * broken even though their documentation says it isn't and their support
 * is entirely unwilling to provide any assistance with their channel banks
 * even though their web site says they support their products for life.
 */
/* #define ZHONE_HACK */

/*! \note
 * Define if you want to check the hook state for an FXO (FXS signalled) interface
 * before dialing on it.  Certain FXO interfaces always think they're out of
 * service with this method however.
 */
/* #define ZAP_CHECK_HOOKSTATE */

/*! \brief Typically, how many rings before we should send Caller*ID */
#define DEFAULT_CIDRINGS 1

#define CHANNEL_PSEUDO -12

#define AST_LAW(p) (((p)->law == ZT_LAW_ALAW) ? AST_FORMAT_ALAW : AST_FORMAT_ULAW)

/*! \brief Signaling types that need to use MF detection should be placed in this macro */
#define NEED_MFDETECT(p) (((p)->sig == SIG_FEATDMF) || ((p)->sig == SIG_FEATDMF_TA) || ((p)->sig == SIG_E911) || ((p)->sig == SIG_FGC_CAMA) || ((p)->sig == SIG_FGC_CAMAMF) || ((p)->sig == SIG_FEATB)) 

static const char desc[] = "Zapata Telephony"
#ifdef ZAPATA_PRI
               " w/PRI"
#endif
#ifdef ZAPATA_R2
               " w/R2"
#endif
;

static const char tdesc[] = "Zapata Telephony Driver"
#ifdef ZAPATA_PRI
               " w/PRI"
#endif
#ifdef ZAPATA_R2
               " w/R2"
#endif
;

static const char config[] = "zapata.conf";

#define SIG_EM		ZT_SIG_EM
#define SIG_EMWINK 	(0x0100000 | ZT_SIG_EM)
#define SIG_FEATD	(0x0200000 | ZT_SIG_EM)
#define	SIG_FEATDMF	(0x0400000 | ZT_SIG_EM)
#define	SIG_FEATB	(0x0800000 | ZT_SIG_EM)
#define	SIG_E911	(0x1000000 | ZT_SIG_EM)
#define	SIG_FEATDMF_TA	(0x2000000 | ZT_SIG_EM)
#define	SIG_FGC_CAMA	(0x4000000 | ZT_SIG_EM)
#define	SIG_FGC_CAMAMF	(0x8000000 | ZT_SIG_EM)
#define SIG_FXSLS	ZT_SIG_FXSLS
#define SIG_FXSGS	ZT_SIG_FXSGS
#define SIG_FXSKS	ZT_SIG_FXSKS
#define SIG_FXOLS	ZT_SIG_FXOLS
#define SIG_FXOGS	ZT_SIG_FXOGS
#define SIG_FXOKS	ZT_SIG_FXOKS
#define SIG_PRI		ZT_SIG_CLEAR
#define SIG_R2		ZT_SIG_CAS
#define	SIG_SF		ZT_SIG_SF
#define SIG_SFWINK 	(0x0100000 | ZT_SIG_SF)
#define SIG_SF_FEATD	(0x0200000 | ZT_SIG_SF)
#define	SIG_SF_FEATDMF	(0x0400000 | ZT_SIG_SF)
#define	SIG_SF_FEATB	(0x0800000 | ZT_SIG_SF)
#define SIG_EM_E1	ZT_SIG_EM_E1
#define SIG_GR303FXOKS	(0x0100000 | ZT_SIG_FXOKS)
#define SIG_GR303FXSKS	(0x0100000 | ZT_SIG_FXSKS)

#define NUM_SPANS 		32
#define NUM_DCHANS		4	/*!< No more than 4 d-channels */
#define MAX_CHANNELS	672		/*!< No more than a DS3 per trunk group */

#define CHAN_PSEUDO	-2

#define DCHAN_PROVISIONED (1 << 0)
#define DCHAN_NOTINALARM  (1 << 1)
#define DCHAN_UP          (1 << 2)

#define DCHAN_AVAILABLE	(DCHAN_PROVISIONED | DCHAN_NOTINALARM | DCHAN_UP)

static char context[AST_MAX_CONTEXT] = "default";
static char cid_num[256] = "";
static char cid_name[256] = "";
static char defaultcic[64] = "";
static char defaultozz[64] = "";

static char language[MAX_LANGUAGE] = "";
static char musicclass[MAX_MUSICCLASS] = "";
static char progzone[10]= "";

static int usedistinctiveringdetection = 0;

static int transfertobusy = 1;

static int use_callerid = 1;
static int cid_signalling = CID_SIG_BELL;
static int cid_start = CID_START_RING;
static int zaptrcallerid = 0;
static int cur_signalling = -1;
static int cur_outsignalling = -1;

static ast_group_t cur_group = 0;
static ast_group_t cur_callergroup = 0;
static ast_group_t cur_pickupgroup = 0;
static int relaxdtmf = 0;

static int immediate = 0;

static int stripmsd = 0;

static int callwaiting = 0;

static int callwaitingcallerid = 0;

static int hidecallerid = 0;

static int restrictcid = 0;

static int use_callingpres = 0;

static int callreturn = 0;

static int threewaycalling = 0;

static int transfer = 0;

static int canpark = 0;

static int cancallforward = 0;

static float rxgain = 0.0;

static float txgain = 0.0;

static int tonezone = -1;

static int echocancel;

static int echotraining;

static int pulse;

static int echocanbridged = 0;

static int busydetect = 0;

static int busycount = 3;
static int busy_tonelength = 0;
static int busy_quietlength = 0;

static int callprogress = 0;

static char accountcode[AST_MAX_ACCOUNT_CODE] = "";

static char mailbox[AST_MAX_EXTENSION];

static int amaflags = 0;

static int adsi = 0;
#ifdef WITH_SMDI
static int use_smdi = 0;
static char smdi_port[SMDI_MAX_FILENAME_LEN] = "/dev/ttyS0";
#endif
static int numbufs = 4;

static int cur_prewink = -1;
static int cur_preflash = -1;
static int cur_wink = -1;
static int cur_flash = -1;
static int cur_start = -1;
static int cur_rxwink = -1;
static int cur_rxflash = -1;
static int cur_debounce = -1;
static int cur_priexclusive = 0;

static int priindication_oob = 0;

#ifdef ZAPATA_PRI
static int minunused = 2;
static int minidle = 0;
static char idleext[AST_MAX_EXTENSION];
static char idledial[AST_MAX_EXTENSION];
static int overlapdial = 0;
static int facilityenable = 0;
static char internationalprefix[10] = "";
static char nationalprefix[10] = "";
static char localprefix[20] = "";
static char privateprefix[20] = "";
static char unknownprefix[20] = "";
static long resetinterval = 3600;	/*!< How often (in seconds) to reset unused channels. Default 1 hour. */
static struct ast_channel inuse;
#ifdef PRI_GETSET_TIMERS
static int pritimers[PRI_MAX_TIMERS];
#endif
static int pridebugfd = -1;
static char pridebugfilename[1024]="";
#endif

/*! \brief Wait up to 16 seconds for first digit (FXO logic) */
static int firstdigittimeout = 16000;

/*! \brief How long to wait for following digits (FXO logic) */
static int gendigittimeout = 8000;

/*! \brief How long to wait for an extra digit, if there is an ambiguous match */
static int matchdigittimeout = 3000;

static int usecnt =0;
AST_MUTEX_DEFINE_STATIC(usecnt_lock);

/*! \brief Protect the interface list (of zt_pvt's) */
AST_MUTEX_DEFINE_STATIC(iflock);


static int ifcount = 0;

#ifdef ZAPATA_PRI
AST_MUTEX_DEFINE_STATIC(pridebugfdlock);
#endif

/*! \brief Whether we answer on a Polarity Switch event */
static int answeronpolarityswitch = 0;

/*! \brief Whether we hang up on a Polarity Switch event */
static int hanguponpolarityswitch = 0;

/*! \brief How long (ms) to ignore Polarity Switch events after we answer a call */
static int polarityonanswerdelay = 600;

/*! \brief When to send the CallerID signals (rings) */
static int sendcalleridafter = DEFAULT_CIDRINGS;

/*! \brief Protect the monitoring thread, so only one process can kill or start it, and not
   when it's doing something critical. */
AST_MUTEX_DEFINE_STATIC(monlock);

/*! \brief This is the thread for the monitor which checks for input on the channels
   which are not currently in use.  */
static pthread_t monitor_thread = AST_PTHREADT_NULL;

static int restart_monitor(void);

static enum ast_bridge_result zt_bridge(struct ast_channel *c0, struct ast_channel *c1, int flags, struct ast_frame **fo, struct ast_channel **rc, int timeoutms);

static int zt_sendtext(struct ast_channel *c, const char *text);

/*! \brief Avoid the silly zt_getevent which ignores a bunch of events */
static inline int zt_get_event(int fd)
{
	int j;
	if (ioctl(fd, ZT_GETEVENT, &j) == -1) return -1;
	return j;
}

/*! \brief Avoid the silly zt_waitevent which ignores a bunch of events */
static inline int zt_wait_event(int fd)
{
	int i,j=0;
	i = ZT_IOMUX_SIGEVENT;
	if (ioctl(fd, ZT_IOMUX, &i) == -1) return -1;
	if (ioctl(fd, ZT_GETEVENT, &j) == -1) return -1;
	return j;
}

/*! Chunk size to read -- we use 20ms chunks to make things happy.  */   
#define READ_SIZE 160

#define MASK_AVAIL		(1 << 0)	/*!< Channel available for PRI use */
#define MASK_INUSE		(1 << 1)	/*!< Channel currently in use */

#define CALLWAITING_SILENT_SAMPLES	( (300 * 8) / READ_SIZE) /*!< 300 ms */
#define CALLWAITING_REPEAT_SAMPLES	( (10000 * 8) / READ_SIZE) /*!< 300 ms */
#define CIDCW_EXPIRE_SAMPLES		( (500 * 8) / READ_SIZE) /*!< 500 ms */
#define MIN_MS_SINCE_FLASH			( (2000) )	/*!< 2000 ms */
#define DEFAULT_RINGT 				( (8000 * 8) / READ_SIZE)

struct zt_pvt;


#ifdef ZAPATA_R2
static int r2prot = -1;
#endif

static int ringt_base = DEFAULT_RINGT;

#ifdef ZAPATA_PRI

#define PVT_TO_CHANNEL(p) (((p)->prioffset) | ((p)->logicalspan << 8) | (p->pri->mastertrunkgroup ? 0x10000 : 0))
#define PRI_CHANNEL(p) ((p) & 0xff)
#define PRI_SPAN(p) (((p) >> 8) & 0xff)
#define PRI_EXPLICIT(p) (((p) >> 16) & 0x01)

struct zt_pri {
	pthread_t master;						/*!< Thread of master */
	ast_mutex_t lock;						/*!< Mutex */
	char idleext[AST_MAX_EXTENSION];				/*!< Where to idle extra calls */
	char idlecontext[AST_MAX_CONTEXT];				/*!< What context to use for idle */
	char idledial[AST_MAX_EXTENSION];				/*!< What to dial before dumping */
	int minunused;							/*!< Min # of channels to keep empty */
	int minidle;							/*!< Min # of "idling" calls to keep active */
	int nodetype;							/*!< Node type */
	int switchtype;							/*!< Type of switch to emulate */
	int nsf;							/*!< Network-Specific Facilities */
	int dialplan;							/*!< Dialing plan */
	int localdialplan;						/*!< Local dialing plan */
	char internationalprefix[10];					/*!< country access code ('00' for european dialplans) */
	char nationalprefix[10];					/*!< area access code ('0' for european dialplans) */
	char localprefix[20];						/*!< area access code + area code ('0'+area code for european dialplans) */
	char privateprefix[20];						/*!< for private dialplans */
	char unknownprefix[20];						/*!< for unknown dialplans */
	int dchannels[NUM_DCHANS];					/*!< What channel are the dchannels on */
	int trunkgroup;							/*!< What our trunkgroup is */
	int mastertrunkgroup;						/*!< What trunk group is our master */
	int prilogicalspan;						/*!< Logical span number within trunk group */
	int numchans;							/*!< Num of channels we represent */
	int overlapdial;						/*!< In overlap dialing mode */
	int facilityenable;						/*!< Enable facility IEs */
	struct pri *dchans[NUM_DCHANS];					/*!< Actual d-channels */
	int dchanavail[NUM_DCHANS];					/*!< Whether each channel is available */
	struct pri *pri;						/*!< Currently active D-channel */
	int debug;
	int fds[NUM_DCHANS];						/*!< FD's for d-channels */
	int offset;
	int span;
	int resetting;
	int resetpos;
	time_t lastreset;						/*!< time when unused channels were last reset */
	long resetinterval;						/*!< Interval (in seconds) for resetting unused channels */
	struct zt_pvt *pvts[MAX_CHANNELS];				/*!< Member channel pvt structs */
	struct zt_pvt *crvs;						/*!< Member CRV structs */
	struct zt_pvt *crvend;						/*!< Pointer to end of CRV structs */
};


static struct zt_pri pris[NUM_SPANS];

static int pritype = PRI_CPE;

#if 0
#define DEFAULT_PRI_DEBUG (PRI_DEBUG_Q931_DUMP | PRI_DEBUG_Q921_DUMP | PRI_DEBUG_Q921_RAW | PRI_DEBUG_Q921_STATE)
#else
#define DEFAULT_PRI_DEBUG 0
#endif

static inline void pri_rel(struct zt_pri *pri)
{
	ast_mutex_unlock(&pri->lock);
}

static int switchtype = PRI_SWITCH_NI2;
static int nsf = PRI_NSF_NONE;
static int dialplan = PRI_NATIONAL_ISDN + 1;
static int localdialplan = PRI_NATIONAL_ISDN + 1;

#else
/*! Shut up the compiler */
struct zt_pri;
#endif

#define SUB_REAL	0			/*!< Active call */
#define SUB_CALLWAIT	1			/*!< Call-Waiting call on hold */
#define SUB_THREEWAY	2			/*!< Three-way call */

/* Polarity states */
#define POLARITY_IDLE   0
#define POLARITY_REV    1


static struct zt_distRings drings;

struct distRingData {
	int ring[3];
};
struct ringContextData {
	char contextData[AST_MAX_CONTEXT];
};
struct zt_distRings {
	struct distRingData ringnum[3];
	struct ringContextData ringContext[3];
};

static char *subnames[] = {
	"Real",
	"Callwait",
	"Threeway"
};

struct zt_subchannel {
	int zfd;
	struct ast_channel *owner;
	int chan;
	short buffer[AST_FRIENDLY_OFFSET/2 + READ_SIZE];
	struct ast_frame f;		/*!< One frame for each channel.  How did this ever work before? */
	unsigned int needringing:1;
	unsigned int needbusy:1;
	unsigned int needcongestion:1;
	unsigned int needcallerid:1;
	unsigned int needanswer:1;
	unsigned int needflash:1;
	unsigned int linear:1;
	unsigned int inthreeway:1;
	ZT_CONFINFO curconf;
};

#define CONF_USER_REAL		(1 << 0)
#define CONF_USER_THIRDCALL	(1 << 1)

#define MAX_SLAVES	4

static struct zt_pvt {
	ast_mutex_t lock;
	struct ast_channel *owner;			/*!< Our current active owner (if applicable) */
							/*!< Up to three channels can be associated with this call */
		
	struct zt_subchannel sub_unused;		/*!< Just a safety precaution */
	struct zt_subchannel subs[3];			/*!< Sub-channels */
	struct zt_confinfo saveconf;			/*!< Saved conference info */

	struct zt_pvt *slaves[MAX_SLAVES];		/*!< Slave to us (follows our conferencing) */
	struct zt_pvt *master;				/*!< Master to us (we follow their conferencing) */
	int inconference;				/*!< If our real should be in the conference */
	
	int sig;					/*!< Signalling style */
	int radio;					/*!< radio type */
	int outsigmod;					/*!< Outbound Signalling style (modifier) */
	float rxgain;
	float txgain;
	int tonezone;					/*!< tone zone for this chan, or -1 for default */
	struct zt_pvt *next;				/*!< Next channel in list */
	struct zt_pvt *prev;				/*!< Prev channel in list */

	/* flags */
	unsigned int adsi:1;
	unsigned int answeronpolarityswitch:1;
	unsigned int busydetect:1;
	unsigned int callreturn:1;
	unsigned int callwaiting:1;
	unsigned int callwaitingcallerid:1;
	unsigned int cancallforward:1;
	unsigned int canpark:1;
	unsigned int confirmanswer:1;			/*!< Wait for '#' to confirm answer */
	unsigned int destroy:1;
	unsigned int didtdd:1;				/*!< flag to say its done it once */
	unsigned int dialednone:1;
	unsigned int dialing:1;
	unsigned int digital:1;
	unsigned int dnd:1;
	unsigned int echobreak:1;
	unsigned int echocanbridged:1;
	unsigned int echocanon:1;
	unsigned int faxhandled:1;			/*!< Has a fax tone already been handled? */
	unsigned int firstradio:1;
	unsigned int hanguponpolarityswitch:1;
	unsigned int hardwaredtmf:1;
	unsigned int hidecallerid;
	unsigned int ignoredtmf:1;
	unsigned int immediate:1;			/*!< Answer before getting digits? */
	unsigned int inalarm:1;
	unsigned int mate:1;				/*!< flag to say its in MATE mode */
	unsigned int outgoing:1;
	unsigned int overlapdial:1;
	unsigned int permcallwaiting:1;
	unsigned int permhidecallerid:1;		/*!< Whether to hide our outgoing caller ID or not */
	unsigned int priindication_oob:1;
	unsigned int priexclusive:1;
	unsigned int pulse:1;
	unsigned int pulsedial:1;			/*!< whether a pulse dial phone is detected */
	unsigned int restrictcid:1;			/*!< Whether restrict the callerid -> only send ANI */
	unsigned int threewaycalling:1;
	unsigned int transfer:1;
	unsigned int use_callerid:1;			/*!< Whether or not to use caller id on this channel */
	unsigned int use_callingpres:1;			/*!< Whether to use the callingpres the calling switch sends */
	unsigned int usedistinctiveringdetection:1;
	unsigned int zaptrcallerid:1;			/*!< should we use the callerid from incoming call on zap transfer or not */
	unsigned int transfertobusy:1;			/*!< allow flash-transfers to busy channels */
#if defined(ZAPATA_PRI)
	unsigned int alerting:1;
	unsigned int alreadyhungup:1;
	unsigned int isidlecall:1;
	unsigned int proceeding:1;
	unsigned int progress:1;
	unsigned int resetting:1;
	unsigned int setup_ack:1;
#endif
#if defined(ZAPATA_R2)
	unsigned int hasr2call:1;
	unsigned int r2blocked:1;
	unsigned int sigchecked:1;
#endif
#ifdef WITH_SMDI
	unsigned int use_smdi:1;		/* Whether to use SMDI on this channel */
	struct ast_smdi_interface *smdi_iface;	/* The serial port to listen for SMDI data on */
#endif

	struct zt_distRings drings;

	char context[AST_MAX_CONTEXT];
	char defcontext[AST_MAX_CONTEXT];
	char exten[AST_MAX_EXTENSION];
	char language[MAX_LANGUAGE];
	char musicclass[MAX_MUSICCLASS];
#ifdef PRI_ANI
	char cid_ani[AST_MAX_EXTENSION];
#endif
	char cid_num[AST_MAX_EXTENSION];
	int cid_ton;					/*!< Type Of Number (TON) */
	char cid_name[AST_MAX_EXTENSION];
	char lastcid_num[AST_MAX_EXTENSION];
	char lastcid_name[AST_MAX_EXTENSION];
	char *origcid_num;				/*!< malloced original callerid */
	char *origcid_name;				/*!< malloced original callerid */
	char callwait_num[AST_MAX_EXTENSION];
	char callwait_name[AST_MAX_EXTENSION];
	char rdnis[AST_MAX_EXTENSION];
	char dnid[AST_MAX_EXTENSION];
	unsigned int group;
	int law;
	int confno;					/*!< Our conference */
	int confusers;					/*!< Who is using our conference */
	int propconfno;					/*!< Propagated conference number */
	ast_group_t callgroup;
	ast_group_t pickupgroup;
	int channel;					/*!< Channel Number or CRV */
	int span;					/*!< Span number */
	time_t guardtime;				/*!< Must wait this much time before using for new call */
	int cid_signalling;				/*!< CID signalling type bell202 or v23 */
	int cid_start;					/*!< CID start indicator, polarity or ring */
	int callingpres;				/*!< The value of callling presentation that we're going to use when placing a PRI call */
	int callwaitingrepeat;				/*!< How many samples to wait before repeating call waiting */
	int cidcwexpire;				/*!< When to expire our muting for CID/CW */
	unsigned char *cidspill;
	int cidpos;
	int cidlen;
	int ringt;
	int ringt_base;
	int stripmsd;
	int callwaitcas;
	int callwaitrings;
	int echocancel;
	int echotraining;
	char echorest[20];
	int busycount;
	int busy_tonelength;
	int busy_quietlength;
	int callprogress;
	struct timeval flashtime;			/*!< Last flash-hook time */
	struct ast_dsp *dsp;
	int cref;					/*!< Call reference number */
	ZT_DIAL_OPERATION dop;
	int whichwink;					/*!< SIG_FEATDMF_TA Which wink are we on? */
	char finaldial[64];
	char accountcode[AST_MAX_ACCOUNT_CODE];		/*!< Account code */
	int amaflags;					/*!< AMA Flags */
	struct tdd_state *tdd;				/*!< TDD flag */
	char call_forward[AST_MAX_EXTENSION];
	char mailbox[AST_MAX_EXTENSION];
	char dialdest[256];
	int onhooktime;
	int msgstate;
	int distinctivering;				/*!< Which distinctivering to use */
	int cidrings;					/*!< Which ring to deliver CID on */
	int dtmfrelax;					/*!< whether to run in relaxed DTMF mode */
	int fake_event;
	int polarityonanswerdelay;
	struct timeval polaritydelaytv;
	int sendcalleridafter;
#ifdef ZAPATA_PRI
	struct zt_pri *pri;
	struct zt_pvt *bearer;
	struct zt_pvt *realcall;
	q931_call *call;
	int prioffset;
	int logicalspan;
#endif	
#ifdef ZAPATA_R2
	int r2prot;
	mfcr2_t *r2;
#endif	
	int polarity;
	int dsp_features;

} *iflist = NULL, *ifend = NULL;

static struct ast_channel *zt_request(const char *type, int format, void *data, int *cause);
static int zt_digit(struct ast_channel *ast, char digit);
static int zt_sendtext(struct ast_channel *c, const char *text);
static int zt_call(struct ast_channel *ast, char *rdest, int timeout);
static int zt_hangup(struct ast_channel *ast);
static int zt_answer(struct ast_channel *ast);
struct ast_frame *zt_read(struct ast_channel *ast);
static int zt_write(struct ast_channel *ast, struct ast_frame *frame);
struct ast_frame *zt_exception(struct ast_channel *ast);
static int zt_indicate(struct ast_channel *chan, int condition);
static int zt_fixup(struct ast_channel *oldchan, struct ast_channel *newchan);
static int zt_setoption(struct ast_channel *chan, int option, void *data, int datalen);

static const struct ast_channel_tech zap_tech = {
	.type = "Zap",
	.description = tdesc,
	.capabilities = AST_FORMAT_SLINEAR | AST_FORMAT_ULAW | AST_FORMAT_ALAW,
	.requester = zt_request,
	.send_digit = zt_digit,
	.send_text = zt_sendtext,
	.call = zt_call,
	.hangup = zt_hangup,
	.answer = zt_answer,
	.read = zt_read,
	.write = zt_write,
	.bridge = zt_bridge,
	.exception = zt_exception,
	.indicate = zt_indicate,
	.fixup = zt_fixup,
	.setoption = zt_setoption,
};

#ifdef ZAPATA_PRI
#define GET_CHANNEL(p) ((p)->bearer ? (p)->bearer->channel : p->channel)
#else
#define GET_CHANNEL(p) ((p)->channel)
#endif

struct zt_pvt *round_robin[32];

#ifdef ZAPATA_PRI
static inline int pri_grab(struct zt_pvt *pvt, struct zt_pri *pri)
{
	int res;
	/* Grab the lock first */
	do {
		res = ast_mutex_trylock(&pri->lock);
		if (res) {
			ast_mutex_unlock(&pvt->lock);
			/* Release the lock and try again */
			usleep(1);
			ast_mutex_lock(&pvt->lock);
		}
	} while(res);
	/* Then break the poll */
	pthread_kill(pri->master, SIGURG);
	return 0;
}
#endif

#define NUM_CADENCE_MAX 25
static int num_cadence = 4;
static int user_has_defined_cadences = 0;

static struct zt_ring_cadence cadences[NUM_CADENCE_MAX] = {
	{ { 125, 125, 2000, 4000 } },			/*!< Quick chirp followed by normal ring */
	{ { 250, 250, 500, 1000, 250, 250, 500, 4000 } }, /*!< British style ring */
	{ { 125, 125, 125, 125, 125, 4000 } },	/*!< Three short bursts */
	{ { 1000, 500, 2500, 5000 } },	/*!< Long ring */
};

int receivedRingT; /*!< Used to find out what ringtone we are on */

/*! \brief cidrings says in which pause to transmit the cid information, where the first pause
 * is 1, the second pause is 2 and so on.
 */

static int cidrings[NUM_CADENCE_MAX] = {
	2,										/*!< Right after first long ring */
	4,										/*!< Right after long part */
	3,										/*!< After third chirp */
	2,										/*!< Second spell */
};

#define ISTRUNK(p) ((p->sig == SIG_FXSLS) || (p->sig == SIG_FXSKS) || \
			(p->sig == SIG_FXSGS) || (p->sig == SIG_PRI))

#define CANBUSYDETECT(p) (ISTRUNK(p) || (p->sig & (SIG_EM | SIG_EM_E1 | SIG_SF)) /* || (p->sig & __ZT_SIG_FXO) */)
#define CANPROGRESSDETECT(p) (ISTRUNK(p) || (p->sig & (SIG_EM | SIG_EM_E1 | SIG_SF)) /* || (p->sig & __ZT_SIG_FXO) */)

static int zt_get_index(struct ast_channel *ast, struct zt_pvt *p, int nullok)
{
	int res;
	if (p->subs[0].owner == ast)
		res = 0;
	else if (p->subs[1].owner == ast)
		res = 1;
	else if (p->subs[2].owner == ast)
		res = 2;
	else {
		res = -1;
		if (!nullok)
			ast_log(LOG_WARNING, "Unable to get index, and nullok is not asserted\n");
	}
	return res;
}

#ifdef ZAPATA_PRI
static void wakeup_sub(struct zt_pvt *p, int a, struct zt_pri *pri)
#else
static void wakeup_sub(struct zt_pvt *p, int a, void *pri)
#endif
{
#ifdef ZAPATA_PRI
	if (pri)
		ast_mutex_unlock(&pri->lock);
#endif			
	for (;;) {
		if (p->subs[a].owner) {
			if (ast_mutex_trylock(&p->subs[a].owner->lock)) {
				ast_mutex_unlock(&p->lock);
				usleep(1);
				ast_mutex_lock(&p->lock);
			} else {
				ast_queue_frame(p->subs[a].owner, &ast_null_frame);
				ast_mutex_unlock(&p->subs[a].owner->lock);
				break;
			}
		} else
			break;
	}
#ifdef ZAPATA_PRI
	if (pri)
		ast_mutex_lock(&pri->lock);
#endif			
}

#ifdef ZAPATA_PRI
static void zap_queue_frame(struct zt_pvt *p, struct ast_frame *f, struct zt_pri *pri)
#else
static void zap_queue_frame(struct zt_pvt *p, struct ast_frame *f, void *pri)
#endif
{
	/* We must unlock the PRI to avoid the possibility of a deadlock */
#ifdef ZAPATA_PRI
	if (pri)
		ast_mutex_unlock(&pri->lock);
#endif		
	for (;;) {
		if (p->owner) {
			if (ast_mutex_trylock(&p->owner->lock)) {
				ast_mutex_unlock(&p->lock);
				usleep(1);
				ast_mutex_lock(&p->lock);
			} else {
				ast_queue_frame(p->owner, f);
				ast_mutex_unlock(&p->owner->lock);
				break;
			}
		} else
			break;
	}
#ifdef ZAPATA_PRI
	if (pri)
		ast_mutex_lock(&pri->lock);
#endif		
}

static int restore_gains(struct zt_pvt *p);

static void swap_subs(struct zt_pvt *p, int a, int b)
{
	int tchan;
	int tinthreeway;
	struct ast_channel *towner;

	ast_log(LOG_DEBUG, "Swapping %d and %d\n", a, b);

	tchan = p->subs[a].chan;
	towner = p->subs[a].owner;
	tinthreeway = p->subs[a].inthreeway;

	p->subs[a].chan = p->subs[b].chan;
	p->subs[a].owner = p->subs[b].owner;
	p->subs[a].inthreeway = p->subs[b].inthreeway;

	p->subs[b].chan = tchan;
	p->subs[b].owner = towner;
	p->subs[b].inthreeway = tinthreeway;

	if (p->subs[a].owner) 
		p->subs[a].owner->fds[0] = p->subs[a].zfd;
	if (p->subs[b].owner) 
		p->subs[b].owner->fds[0] = p->subs[b].zfd;
	wakeup_sub(p, a, NULL);
	wakeup_sub(p, b, NULL);
}

static int zt_open(char *fn)
{
	int fd;
	int isnum;
	int chan = 0;
	int bs;
	int x;
	isnum = 1;
	for (x=0;x<strlen(fn);x++) {
		if (!isdigit(fn[x])) {
			isnum = 0;
			break;
		}
	}
	if (isnum) {
		chan = atoi(fn);
		if (chan < 1) {
			ast_log(LOG_WARNING, "Invalid channel number '%s'\n", fn);
			return -1;
		}
		fn = "/dev/zap/channel";
	}
	fd = open(fn, O_RDWR | O_NONBLOCK);
	if (fd < 0) {
		ast_log(LOG_WARNING, "Unable to open '%s': %s\n", fn, strerror(errno));
		return -1;
	}
	if (chan) {
		if (ioctl(fd, ZT_SPECIFY, &chan)) {
			x = errno;
			close(fd);
			errno = x;
			ast_log(LOG_WARNING, "Unable to specify channel %d: %s\n", chan, strerror(errno));
			return -1;
		}
	}
	bs = READ_SIZE;
	if (ioctl(fd, ZT_SET_BLOCKSIZE, &bs) == -1) return -1;
	return fd;
}

static void zt_close(int fd)
{
	if(fd > 0)
		close(fd);
}

int zt_setlinear(int zfd, int linear)
{
	int res;
	res = ioctl(zfd, ZT_SETLINEAR, &linear);
	if (res)
		return res;
	return 0;
}


int zt_setlaw(int zfd, int law)
{
	int res;
	res = ioctl(zfd, ZT_SETLAW, &law);
	if (res)
		return res;
	return 0;
}

static int alloc_sub(struct zt_pvt *p, int x)
{
	ZT_BUFFERINFO bi;
	int res;
	if (p->subs[x].zfd < 0) {
		p->subs[x].zfd = zt_open("/dev/zap/pseudo");
		if (p->subs[x].zfd > -1) {
			res = ioctl(p->subs[x].zfd, ZT_GET_BUFINFO, &bi);
			if (!res) {
				bi.txbufpolicy = ZT_POLICY_IMMEDIATE;
				bi.rxbufpolicy = ZT_POLICY_IMMEDIATE;
				bi.numbufs = numbufs;
				res = ioctl(p->subs[x].zfd, ZT_SET_BUFINFO, &bi);
				if (res < 0) {
					ast_log(LOG_WARNING, "Unable to set buffer policy on channel %d\n", x);
				}
			} else 
				ast_log(LOG_WARNING, "Unable to check buffer policy on channel %d\n", x);
			if (ioctl(p->subs[x].zfd, ZT_CHANNO, &p->subs[x].chan) == 1) {
				ast_log(LOG_WARNING,"Unable to get channel number for pseudo channel on FD %d\n",p->subs[x].zfd);
				zt_close(p->subs[x].zfd);
				p->subs[x].zfd = -1;
				return -1;
			}
			if (option_debug)