Return to aitpelco.c CVS log

Up to [ELWIX - Embedded LightWeight unIX -] / libaitpelco / src

version 2.0

/*************************************************************************
* (C) 2010 AITNET ltd - Sofia/Bulgaria - <misho@aitbg.com>
*  by Michael Pounov <misho@openbsd-bg.org>
*
* $Author: misho $
* $Id: aitpelco.c,v 1.4 2013/05/30 09:20:16 misho Exp $
*
**************************************************************************
The ELWIX and AITNET software is distributed under the following
terms:

All of the documentation and software included in the ELWIX and AITNET
Releases is copyrighted by ELWIX - Sofia/Bulgaria <info@elwix.org>

Copyright 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013
	by Michael Pounov <misho@elwix.org>.  All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   documentation and/or other materials provided with the distribution.
3. All advertising materials mentioning features or use of this software
   must display the following acknowledgement:
This product includes software developed by Michael Pounov <misho@elwix.org>
ELWIX - Embedded LightWeight unIX and its contributors.
4. Neither the name of AITNET nor the names of its contributors
   may be used to endorse or promote products derived from this software
   without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY AITNET AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.
*/
#include "global.h"
#include "aitpelco.h"


static int pelco_Errno;
static char pelco_Error[STRSIZ];


//
// Error maintenance functions ...
//

// pelco_GetErrno() Get error code of last operation
int
pelco_GetErrno()
{
	return pelco_Errno;
}

// pelco_GetError() Get error text of last operation
const char *
pelco_GetError()
{
	return pelco_Error;
}

// pelco_SetErr() Set error to variables for internal use!!!
void
pelcoSetErr(int eno, char *estr, ...)
{
	va_list lst;

	pelco_Errno = eno;
	memset(pelco_Error, 0, sizeof pelco_Error);
	va_start(lst, estr);
	vsnprintf(pelco_Error, sizeof pelco_Error, estr, lst);
	va_end(lst);
}

// ----------------------------------------------------------

/*
 * pelcoOpen() Open packet record for camera number with Pelco version D/P
 * @pelcoVer = Pelco protocol version Dd | Pp
 * @camNo = Packet for camera number address
 * return: NULL error, !=NULL ok, allocated memory for packet
 */
void *
pelcoOpen(u_char pelcoVer, u_char camNo)
{
	pelco_d_t *pd;
	pelco_p_t *pp;
	void *p = NULL;

	switch (pelcoVer) {
		case 'D':
		case 'd':
			if (camNo < FIRST_CAM_D) {
				pelcoSetErr(ENOEXEC, "unsupported camera number %d!\n", camNo);
				return NULL;
			}

			pd = malloc(sizeof(pelco_d_t));
			if (!pd) {
				SETERR;
				return NULL;
			} else
				memset(pd, 0, sizeof(pelco_d_t));

			pd->d_sync = VER_D_SYNC;
			pd->d_cam = camNo;

			p = pd;
			break;
		case 'P':
		case 'p':
			pp = malloc(sizeof(pelco_p_t));
			if (!pp) {
				SETERR;
				return NULL;
			} else
				memset(pp, 0, sizeof(pelco_p_t));

			pp->p_stx = VER_P_STX;
			pp->p_cam = !camNo ? camNo : camNo - 1;
			pp->p_etx = VER_P_ETX;

			p = pp;
			break;
		default:
			pelcoSetErr(ENOEXEC, "unsupported Pelco protocol version!\n");
	}

	return p;
}

/*
 * pelcoClose() Close packet record and free memory
 * @p = Packet structure for close
 */
void
pelcoClose(void * __restrict p)
{
	if (p)
		free(p);
}

/*
 * pelcoLoad() Load packet from input buffer
 * @buffer = Pelco packet from input buffer
 * return: NULL error, !=NULL ok, allocated memory for packet
 */
void *
pelcoLoad(u_char *buffer)
{
	pelco_d_t *pd;
	pelco_p_t *pp;
	void *p = NULL;

	if (!buffer || !*buffer) {
		pelcoSetErr(EINVAL, "invalid argument!\n");
		return NULL;
	}

	switch (pelco_GetVersion(buffer)) {
		case 'd':
			if (pelco_GetCamNo(buffer) < FIRST_CAM_D) {
				pelcoSetErr(ENOEXEC, "unsupported camera number %d!\n", 
						pelco_GetCamNo(buffer));
				return NULL;
			}

			pd = malloc(sizeof(pelco_d_t));
			if (!pd) {
				SETERR;
				return NULL;
			} else
				memcpy(pd, buffer, sizeof(pelco_d_t));

			p = pd;
			break;
		case 'p':
			pp = malloc(sizeof(pelco_p_t));
			if (!pp) {
				SETERR;
				return NULL;
			} else
				memcpy(pp, buffer, sizeof(pelco_p_t));

			p = pp;
			break;
		default:
			pelcoSetErr(ENOEXEC, "unsupported Pelco protocol version!\n");
	}

	return p;
}

/*
 * pelcoAddCmdData() Add commands and datas for already opened packet
 * @p = Input Packet structure
 * @cmd[2] = Input Commands 1 & 2
 * @data[2] = Input Data for commands 1 & 2
 * return: 0xFF - error, 0 - ok
 */
u_char
pelcoAddCmdData(void * __restrict p, u_char * __restrict cmd, u_char * __restrict data)
{
	u_char ret = 0;
	pelco_d_t *pd = (pelco_d_t *) p;
	pelco_p_t *pp = (pelco_p_t *) p;
	u_char *ptr = p;

	if (!p || !*ptr) {
		pelcoSetErr(EINVAL, "invalid argument!\n");
		return 0xFF;
	}

	switch (ptr[0]) {
		case VER_D_SYNC:
			if (ptr[1] < FIRST_CAM_D) {
				pelcoSetErr(ENOEXEC, "unsupported camera number %d!\n", ptr[1]);
				return 0xFF;
			}

			if (cmd)
				memcpy(&pd->d_cmd1, cmd, 2);
			if (data)
				memcpy(&pd->d_data, data, 2);
			pd->d_crc = crcPelco('d', p);
			break;
		case VER_P_STX:
			if (VER_P_ETX != ptr[6]) {
				pelcoSetErr(ENOEXEC, "Broken Pelco P packet!\n");
				return 0xFF;
			}

			if (cmd)
				memcpy(&pp->p_cmd1, cmd, 2);
			if (data)
				memcpy(&pp->p_data, data, 2);
			pp->p_crc = crcPelco('p', p);
			break;
		default:
			pelcoSetErr(ENOEXEC, "Invalid protocol!\n");
			return 0xFF;
	}

	return ret;
}

/*
 * pelcoGetCmdData() Get from packet commands and datas with verify packet
 * @p = Input Packet structure
 * @cmd[2] = Output Commands 1 & 2
 * @data[2] = Output Data for commands 1 & 2
 * return: 'd' - PelcoD, 'p' - PelcoP, 0 - unknown or bad packet
 */
u_char
pelcoGetCmdData(void * __restrict p, u_char * __restrict cmd, u_char * __restrict data)
{
	return pelco_GetCamCmdData(p, NULL, cmd, data);
}

/*
 * pelcoChkSum() Check ot Correct check sum in packet
 * @p = Input Packet structure
 * @correct = Calculate new check sum if incorrect !=0, if ==0 only check
 * return: 0xFF - bad packet, 1 invalid check sum, 0 check sum is correct.
 */
u_char
pelcoChkSum(void * __restrict p, u_char correct)
{
	u_char sum, *ptr = p;
	pelco_d_t *pd = (pelco_d_t *) p;
	pelco_p_t *pp = (pelco_p_t *) p;

	if (!p || !*ptr) {
		pelcoSetErr(EINVAL, "invalid argument!\n");
		return 0xFF;
	}

	switch (ptr[0]) {
		case VER_D_SYNC:
			if (ptr[1] < FIRST_CAM_D) {
				pelcoSetErr(ENOEXEC, "unsupported camera number %d!\n", ptr[1]);
				return 0xFF;
			}

			sum = crcPelco('d', p);
			if (correct)
				pd->d_crc = sum;
			break;
		case VER_P_STX:
			if (VER_P_ETX != ptr[6]) {
				pelcoSetErr(ENOEXEC, "Broken Pelco P packet!\n");
				return 0xFF;
			}

			sum = crcPelco('p', p);
			if (correct)
				pp->p_crc = sum;
			break;
		default:
			pelcoSetErr(ENOEXEC, "Invalid protocol!\n");
			return 0xFF;
	}

	return sum;
}