/*
 * (CAPI*)
 *
 * An implementation of Common ISDN API 2.0 for Asterisk
 *
 * Copyright (C) 2006-2007 Cytronics & Melware
 *
 * Armin Schindler <armin@melware.de>
 * 
 * This program is free software and may be modified and 
 * distributed under the terms of the GNU Public License.
 */
 
#include <stdio.h>
#include <stdlib.h>
#include "chan_capi20.h"
#include "chan_capi.h"
#include "chan_capi_utils.h"
#include "chan_capi_supplementary.h"

int capidebug = 0;
char *emptyid = "\0";

AST_MUTEX_DEFINE_STATIC(verbose_lock);
AST_MUTEX_DEFINE_STATIC(messagenumber_lock);
AST_MUTEX_DEFINE_STATIC(capi_put_lock);

static _cword capi_MessageNumber;

#define CAPI_MAX_PEERLINKCHANNELS  32
static struct ast_channel *peerlinkchannel[CAPI_MAX_PEERLINKCHANNELS];

/*
 * helper for <pbx>_verbose with different verbose settings
 */
void cc_verbose(int o_v, int c_d, char *text, ...)
{
	char line[4096];
	va_list ap;

	va_start(ap, text);
	vsnprintf(line, sizeof(line), text, ap);
	va_end(ap);

	if ((o_v == 0) || (option_verbose > o_v)) {
		if ((!c_d) || ((c_d) && (capidebug))) {	
			cc_mutex_lock(&verbose_lock);
			cc_pbx_verbose(line);
			cc_mutex_unlock(&verbose_lock);	
		}
	}
}

/*
 * get a new capi message number automically
 */
_cword get_capi_MessageNumber(void)
{
	_cword mn;

	cc_mutex_lock(&messagenumber_lock);

	capi_MessageNumber++;
	if (capi_MessageNumber == 0) {
	    /* avoid zero */
	    capi_MessageNumber = 1;
	}

	mn = capi_MessageNumber;

	cc_mutex_unlock(&messagenumber_lock);

	return(mn);
}

/*
 * write a capi message to capi device
 */
MESSAGE_EXCHANGE_ERROR _capi_put_cmsg(_cmsg *CMSG)
{
	MESSAGE_EXCHANGE_ERROR error;
	
	if (cc_mutex_lock(&capi_put_lock)) {
		cc_log(LOG_WARNING, "Unable to lock capi put!\n");
		return -1;
	} 
	
	error = capi20_put_cmsg(CMSG);
	
	if (cc_mutex_unlock(&capi_put_lock)) {
		cc_log(LOG_WARNING, "Unable to unlock capi put!\n");
		return -1;
	}

	if (error) {
		cc_log(LOG_ERROR, "CAPI error sending %s (NCCI=%#x) (error=%#x %s)\n",
			capi_cmsg2str(CMSG), (unsigned int)HEADER_CID(CMSG),
			error, capi_info_string((unsigned int)error));
	} else {
		unsigned short wCmd = HEADER_CMD(CMSG);
		if ((wCmd == CAPI_P_REQ(DATA_B3)) ||
		    (wCmd == CAPI_P_RESP(DATA_B3))) {
			cc_verbose(7, 1, "%s\n", capi_cmsg2str(CMSG));
		} else {
			cc_verbose(4, 1, "%s\n", capi_cmsg2str(CMSG));
		}
	}

	return error;
}

/*
 * wait some time for a new capi message
 */
MESSAGE_EXCHANGE_ERROR capidev_check_wait_get_cmsg(_cmsg *CMSG)
{
	MESSAGE_EXCHANGE_ERROR Info;
	struct timeval tv;

 repeat:
	Info = capi_get_cmsg(CMSG, capi_ApplID);

#if (CAPI_OS_HINT == 1) || (CAPI_OS_HINT == 2)
	/*
	 * For BSD allow controller 0:
	 */
	if ((HEADER_CID(CMSG) & 0xFF) == 0) {
		HEADER_CID(CMSG) += capi_num_controllers;
 	}
#endif

	/* if queue is empty */
	if (Info == 0x1104) {
		/* try waiting a maximum of 0.100 seconds for a message */
		tv.tv_sec = 0;
		tv.tv_usec = 10000;
		
		Info = capi20_waitformessage(capi_ApplID, &tv);

		if (Info == 0x0000)
			goto repeat;
	}
	
	if ((Info != 0x0000) && (Info != 0x1104)) {
		if (capidebug) {
			cc_log(LOG_DEBUG, "Error waiting for cmsg... INFO = %#x\n", Info);
		}
	}
    
	return Info;
}

/*
 * decode capi 2.0 info word
 */
char *capi_info_string(unsigned int info)
{
	switch (info) {
	/* informative values (corresponding message was processed) */
	case 0x0001:
		return "NCPI not supported by current protocol, NCPI ignored";
	case 0x0002:
		return "Flags not supported by current protocol, flags ignored";
	case 0x0003:
		return "Alert already sent by another application";

	/* error information concerning CAPI_REGISTER */
	case 0x1001:
		return "Too many applications";
	case 0x1002:
		return "Logical block size to small, must be at least 128 Bytes";
	case 0x1003:
		return "Buffer exceeds 64 kByte";
	case 0x1004:
		return "Message buffer size too small, must be at least 1024 Bytes";
	case 0x1005:
		return "Max. number of logical connections not supported";
	case 0x1006:
		return "Reserved";
	case 0x1007:
		return "The message could not be accepted because of an internal busy condition";
	case 0x1008:
		return "OS resource error (no memory ?)";
	case 0x1009:
		return "CAPI not installed";
	case 0x100A:
		return "Controller does not support external equipment";
	case 0x100B:
		return "Controller does only support external equipment";

	/* error information concerning message exchange functions */
	case 0x1101:
		return "Illegal application number";
	case 0x1102:
		return "Illegal command or subcommand or message length less than 12 bytes";
	case 0x1103:
		return "The message could not be accepted because of a queue full condition !! The error code does not imply that CAPI cannot receive messages directed to another controller, PLCI or NCCI";
	case 0x1104:
		return "Queue is empty";
	case 0x1105:
		return "Queue overflow, a message was lost !! This indicates a configuration error. The only recovery from this error is to perform a CAPI_RELEASE";
	case 0x1106:
		return "Unknown notification parameter";
	case 0x1107:
		return "The Message could not be accepted because of an internal busy condition";
	case 0x1108:
		return "OS Resource error (no memory ?)";
	case 0x1109:
		return "CAPI not installed";
	case 0x110A:
		return "Controller does not support external equipment";
	case 0x110B:
		return "Controller does only support external equipment";

	/* error information concerning resource / coding problems */
	case 0x2001:
		return "Message not supported in current state";
	case 0x2002:
		return "Illegal Controller / PLCI / NCCI";
	case 0x2003:
		return "Out of PLCIs";
	case 0x2004:
		return "Out of NCCIs";
	case 0x2005:
		return "Out of LISTEN requests";
	case 0x2006:
		return "Out of FAX resources (protocol T.30)";
	case 0x2007:
		return "Illegal message parameter coding";

	/* error information concerning requested services */
	case 0x3001:
		return "B1 protocol not supported";
	case 0x3002:
		return "B2 protocol not supported";
	case 0x3003:
		return "B3 protocol not supported";
	case 0x3004:
		return "B1 protocol parameter not supported";
	case 0x3005:
		return "B2 protocol parameter not supported";
	case 0x3006:
		return "B3 protocol parameter not supported";
	case 0x3007:
		return "B protocol combination not supported";
	case 0x3008:
		return "NCPI not supported";
	case 0x3009:
		return "CIP Value unknown";
	case 0x300A:
		return "Flags not supported (reserved bits)";
	case 0x300B:
		return "Facility not supported";
	case 0x300C:
		return "Data length not supported by current protocol";
	case 0x300D:
		return "Reset procedure not supported by current protocol";
	case 0x300E:
		return "TEI assignment failed or supplementary service not supported";
	case 0x3010:
		return "Request not allowed in this state";

	/* informations about the clearing of a physical connection */
	case 0x3301:
		return "Protocol error layer 1 (broken line or B-channel removed by signalling protocol)";
	case 0x3302:
		return "Protocol error layer 2";
	case 0x3303:
		return "Protocol error layer 3";
	case 0x3304:
		return "Another application got that call";

	/* T.30 specific reasons */
	case 0x3311:
		return "Connecting not successful (remote station is no FAX G3 machine)";
	case 0x3312:
		return "Connecting not successful (training error)";
	case 0x3313:
		return "Disconnected before transfer (remote station does not support transfer mode, e.g. resolution)";
	case 0x3314:
		return "Disconnected during transfer (remote abort)";
	case 0x3315:
		return "Disconnected during transfer (remote procedure error, e.g. unsuccessful repetition of T.30 commands)";
	case 0x3316:
		return "Disconnected during transfer (local tx data underrun)";
	case 0x3317:
		return "Disconnected during transfer (local rx data overflow)";
	case 0x3318:
		return "Disconnected during transfer (local abort)";
	case 0x3319:
		return "Illegal parameter coding (e.g. SFF coding error)";

	/* disconnect causes from the network according to ETS 300 102-1/Q.931 */
	case 0x3481:
		return "Unallocated (unassigned) number";
	case 0x3482:
		return "No route to specified transit network";
	case 0x3483:
		return "No route to destination";
	case 0x3486:
		return "Channel unacceptable";
	case 0x3487:
		return "Call awarded and being delivered in an established channel";
	case 0x3490:
		return "Normal call clearing";
	case 0x3491:
		return "User busy";
	case 0x3492:
		return "No user responding";
	case 0x3493:
		return "No answer from user (user alerted)";
	case 0x3495:
		return "Call rejected";
	case 0x3496:
		return "Number changed";
	case 0x349A:
		return "Non-selected user clearing";
	case 0x349B:
		return "Destination out of order";
	case 0x349C:
		return "Invalid number format";
	case 0x349D:
		return "Facility rejected";
	case 0x349E:
		return "Response to STATUS ENQUIRY";
	case 0x349F:
		return "Normal, unspecified";
	case 0x34A2:
		return "No circuit / channel available";
	case 0x34A6:
		return "Network out of order";
	case 0x34A9:
		return "Temporary failure";
	case 0x34AA:
		return "Switching equipment congestion";
	case 0x34AB:
		return "Access information discarded";
	case 0x34AC:
		return "Requested circuit / channel not available";
	case 0x34AF:
		return "Resources unavailable, unspecified";
	case 0x34B1:
		return "Quality of service unavailable";
	case 0x34B2:
		return "Requested facility not subscribed";
	case 0x34B9:
		return "Bearer capability not authorized";
	case 0x34BA:
		return "Bearer capability not presently available";
	case 0x34BF:
		return "Service or option not available, unspecified";
	case 0x34C1:
		return "Bearer capability not implemented";
	case 0x34C2:
		return "Channel type not implemented";
	case 0x34C5:
		return "Requested facility not implemented";
	case 0x34C6:
		return "Only restricted digital information bearer capability is available";
	case 0x34CF:
		return "Service or option not implemented, unspecified";
	case 0x34D1:
		return "Invalid call reference value";
	case 0x34D2:
		return "Identified channel does not exist";
	case 0x34D3:
		return "A suspended call exists, but this call identity does not";
	case 0x34D4:
		return "Call identity in use";
	case 0x34D5:
		return "No call suspended";
	case 0x34D6:
		return "Call having the requested call identity has been cleared";
	case 0x34D8:
		return "Incompatible destination";
	case 0x34DB:
		return "Invalid transit network selection";
	case 0x34DF:
		return "Invalid message, unspecified";
	case 0x34E0:
		return "Mandatory information element is missing";
	case 0x34E1:
		return "Message type non-existent or not implemented";
	case 0x34E2:
		return "Message not compatible with call state or message type non-existent or not implemented";
	case 0x34E3:
		return "Information element non-existent or not implemented";
	case 0x34E4:
		return "Invalid information element contents";
	case 0x34E5:
		return "Message not compatible with call state";
	case 0x34E6:
		return "Recovery on timer expiry";
	case 0x34EF:
		return "Protocol error, unspecified";
	case 0x34FF:
		return "Interworking, unspecified";

	/* B3 protocol 7 (Modem) */
	case 0x3500:
		return "Normal end of connection";
	case 0x3501:
		return "Carrier lost";
	case 0x3502:
		return "Error on negotiation, i.e. no modem with error correction at other end";
	case 0x3503:
		return "No answer to protocol request";
	case 0x3504:
		return "Remote modem only works in synchronous mode";
	case 0x3505:
		return "Framing fails";
	case 0x3506:
		return "Protocol negotiation fails";
	case 0x3507:
		return "Other modem sends wrong protocol request";
	case 0x3508:
		return "Sync information (data or flags) missing";
	case 0x3509:
		return "Normal end of connection from the other modem";
	case 0x350a:
		return "No answer from other modem";
	case 0x350b:
		return "Protocol error";
	case 0x350c:
		return "Error on compression";
	case 0x350d:
		return "No connect (timeout or wrong modulation)";
	case 0x350e:
		return "No protocol fall-back allowed";
	case 0x350f:
		return "No modem or fax at requested number";
	case 0x3510:
		return "Handshake error";

	/* error info concerning the requested supplementary service */
	case 0x3600:
		return "Supplementary service not subscribed";
	case 0x3603:
		return "Supplementary service not available";
	case 0x3604:
		return "Supplementary service not implemented";
	case 0x3606:
		return "Invalid served user number";
	case 0x3607:
		return "Invalid call state";
	case 0x3608:
		return "Basic service not provided";
	case 0x3609:
		return "Supplementary service not requested for an incoming call";
	case 0x360a:
		return "Supplementary service interaction not allowed";
	case 0x360b:
		return "Resource unavailable";

	/* error info concerning the context of a supplementary service request */
	case 0x3700:
		return "Duplicate invocation";
	case 0x3701:
		return "Unrecognized operation";
	case 0x3702:
		return "Mistyped argument";
	case 0x3703:
		return "Resource limitation";
	case 0x3704:
		return "Initiator releasing";
	case 0x3705:
		return "Unrecognized linked-ID";
	case 0x3706:
		return "Linked response unexpected";
	case 0x3707:
		return "Unexpected child operation";

	/* Line Interconnect */
	case 0x3800:
		return "PLCI has no B-channel";
	case 0x3801:
		return "Lines not compatible";
	case 0x3802:
		return "PLCI(s) is (are) not in any or not in the same interconnection";

	default:
		return NULL;
	}
}

/*
 * show the text for a CAPI message info value
 */
void show_capi_info(struct capi_pvt *i, _cword info)
{
	char *p;
	char *name = "?";
	
	if (info == 0x0000) {
		/* no error, do nothing */
		return;
	}

	if (!(p = capi_info_string((unsigned int)info))) {
		/* message not available */
		return;
	}

	if (i)
		name = i->vname;
	
	cc_verbose(3, 0, VERBOSE_PREFIX_4 "%s: CAPI INFO 0x%04x: %s\n",
		name, info, p);
	return;
}

/*
 * send Listen to specified controller
 */
unsigned ListenOnController(unsigned long CIPmask, unsigned controller)
{
	MESSAGE_EXCHANGE_ERROR error;
	_cmsg CMSG;
	int waitcount = 50;

	LISTEN_REQ_HEADER(&CMSG, capi_ApplID, get_capi_MessageNumber(), controller);

	LISTEN_REQ_INFOMASK(&CMSG) = 0xffff; /* lots of info ;) + early B3 connect */
		/* 0x00ff if no early B3 should be done */
		
	LISTEN_REQ_CIPMASK(&CMSG) = CIPmask;
	error = _capi_put_cmsg(&CMSG);

	if (error)
		goto done;

	while (waitcount) {
		error = capidev_check_wait_get_cmsg(&CMSG);

		if (IS_LISTEN_CONF(&CMSG)) {
			error = LISTEN_CONF_INFO(&CMSG);
			ListenOnSupplementary(controller);
			break;
		}
		usleep(30000);
		waitcount--;
	}
	if (!waitcount)
		error = 0x100F;

 done:
	return error;
}

/*
 * convert a number
 */
char *capi_number_func(unsigned char *data, unsigned int strip, char *buf)
{
	unsigned int len;

	if (data[0] == 0xff) {
		len = read_capi_word(&data[1]);
		data += 2;
	} else {
		len = data[0];
		data += 1;
	}
	if (len > (AST_MAX_EXTENSION - 1))
		len = (AST_MAX_EXTENSION - 1);
	
	/* convert a capi struct to a \0 terminated string */
	if ((!len) || (len < strip))
		return NULL;
		
	len = len - strip;
	data += strip;

	memcpy(buf, data, len);
	buf[len] = '\0';
	
	return buf;
}

/*
 * parse the dialstring
 */
void parse_dialstring(char *buffer, char **interface, char **dest, char **param, char **ocid)
{
	int cp = 0;
	char *buffer_p = buffer;
	char *oc;

	/* interface is the first part of the string */
	*interface = buffer;

	*dest = emptyid;
	*param = emptyid;
	*ocid = NULL;

	while (*buffer_p) {
		if (*buffer_p == '/') {
			*buffer_p = 0;
			buffer_p++;
			if (cp == 0) {
				*dest = buffer_p;
				cp++;
			} else if (cp == 1) {
				*param = buffer_p;
				cp++;
			} else {
				cc_log(LOG_WARNING, "Too many parts in dialstring '%s'\n",
					buffer);
			}
			continue;
		}
		buffer_p++;
	}
	if ((oc = strchr(*dest, ':')) != NULL) {
		*ocid = *dest;
		*oc = '\0';
		*dest = oc + 1;
	}
	cc_verbose(3, 1, VERBOSE_PREFIX_4 "parsed dialstring: '%s' '%s' '%s' '%s'\n",
		*interface, (*ocid) ? *ocid : "NULL", *dest, *param);
	return;
}

/*
 * Add a new peer link id
 */
int cc_add_peer_link_id(struct ast_channel *c)
{
	int a;

	for (a = 0; a < CAPI_MAX_PEERLINKCHANNELS; a++) {
		if (peerlinkchannel[a] == NULL) {
			peerlinkchannel[a] = c;
			break;
		}
	}
	if (a == CAPI_MAX_PEERLINKCHANNELS) {
		return -1;
	}
	return a;
}

/*
 * Get and remove peer link id
 */
struct ast_channel *cc_get_peer_link_id(const char *p)
{
	int id = -1;
	struct ast_channel *chan = NULL;

	if (p) {
		id = (int)strtol(p, NULL, 0);
	}

	if ((id >= 0) && (id < CAPI_MAX_PEERLINKCHANNELS)) {
		chan = peerlinkchannel[id];
		peerlinkchannel[id] = NULL;
	}
	return chan;
}