xref: /third_party/backends/backend/magicolor.c

/*
 * magicolor.c - SANE library for Magicolor scanners.
 *
 * (C) 2010 Reinhold Kainhofer <reinhold@kainhofer.com>
 *
 * Based on the epson2 sane backend:
 * Based on Kazuhiro Sasayama previous
 * Work on epson.[ch] file from the SANE package.
 * Please see those files for additional copyrights.
 * Copyright (C) 2006-10 Tower Technologies
 * Author: Alessandro Zummo <a.zummo@towertech.it>
 *
 * This file is part of the SANE package.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, version 2.
 */

#define MAGICOLOR_VERSION	0
#define MAGICOLOR_REVISION	0
#define MAGICOLOR_BUILD	1

/* debugging levels:
 *
 *     127	mc_recv buffer
 *     125	mc_send buffer
 *	35	fine-grained status and progress
 *	30	sane_read
 *	25	setvalue, getvalue, control_option
 *	20	low-level (I/O) mc_* functions
 *	15	mid-level mc_* functions
 *	10	high-level cmd_* functions
 *	 7	open/close/attach
 *	 6	print_params
 *	 5	basic functions
 *	 3	status info and progress
 *	 2	scanner info and capabilities
 *	 1	errors & warnings
 */

#include "sane/config.h"

#include <limits.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <sys/time.h>
#include <math.h>
#include <poll.h>
#include <sys/types.h>
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif


#if HAVE_LIBSNMP
#include <net-snmp/net-snmp-config.h>
#include <net-snmp/net-snmp-includes.h>
#include <net-snmp/library/snmp_transport.h>
#include <arpa/inet.h>
#endif

#include "../include/sane/saneopts.h"
#include "../include/sane/sanei_usb.h"
#include "../include/sane/sanei_tcp.h"
#include "../include/sane/sanei_udp.h"
#include "../include/sane/sanei_config.h"
#include "../include/sane/sanei_backend.h"

#include "magicolor.h"


#define min(x,y) (((x)<(y))?(x):(y))



/****************************************************************************
 *   Devices supported by this backend
 ****************************************************************************/



/*          Scanner command type
 *          |     Start scan
 *          |     |     Poll for error
 *          |     |     |     Stop scan?
 *          |     |     |     |     Query image parameters
 *          |     |     |     |     |     set scan parameters
 *          |     |     |     |     |     |     Get status?
 *          |     |     |     |     |     |     |     Read scanned data
 *          |     |     |     |     |     |     |     |     Unknown
 *          |     |     |     |     |     |     |     |     |     Unknown
 *          |     |     |     |     |     |     |     |     |     |     Net wrapper command type
 *          |     |     |     |     |     |     |     |     |     |     |     Net Welcome
 *          |     |     |     |     |     |     |     |     |     |     |     |     Net Lock
 *          |     |     |     |     |     |     |     |     |     |     |     |     |     Net Lock ACK
 *          |     |     |     |     |     |     |     |     |     |     |     |     |     |     Net Unlock
 *          |     |     |     |     |     |     |     |     |     |     |     |     |     |     |
*/
static struct MagicolorCmd magicolor_cmd[] = {
  {"mc1690mf", CMD, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x12, NET, 0x00, 0x01, 0x02, 0x03},
  {"mc4690mf", CMD, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x12, NET, 0x00, 0x01, 0x02, 0x03},
};

static SANE_Int magicolor_default_resolutions[] = {150, 300, 600};
static SANE_Int magicolor_default_depths[] = {1,8};

static struct MagicolorCap magicolor_cap[] = {

  /* KONICA MINOLTA magicolor 1690MF, USB ID 0x123b:2089 */
  {
      0x2089, "mc1690mf", "KONICA MINOLTA magicolor 1690MF", ".1.3.6.1.4.1.18334.1.1.1.1.1.23.1.1",
      -1, 0x85,
      600, {150, 600, 0}, magicolor_default_resolutions, 3,  /* 600 dpi max, 3 resolutions */
      8, magicolor_default_depths,                          /* color depth 8 default, 1 and 8 possible */
      {1, 9, 0},                                             /* brightness ranges (TODO!) */
      {0, SANE_FIX(0x13f8 * MM_PER_INCH / 600), 0}, {0, SANE_FIX(0x1b9c * MM_PER_INCH / 600), 0}, /* FBF x/y ranges (TODO!) */
      SANE_TRUE, SANE_FALSE, /* non-duplex ADF, x/y ranges (TODO!) */
      {0, SANE_FIX(0x1390 * MM_PER_INCH / 600), 0}, {0, SANE_FIX(0x20dc * MM_PER_INCH / 600), 0},
  },

  /* KONICA MINOLTA magicolor 4690MF, USB ID 0x132b:2079 */
  {
      0x2079, "mc4690mf", "KONICA MINOLTA magicolor 4690MF",
      "FIXME",                                              /* FIXME: fill in the correct OID! */
      0x03, 0x85,
      600, {150, 600, 0}, magicolor_default_resolutions, 3,  /* 600 dpi max, 3 resolutions */
      8, magicolor_default_depths,                          /* color depth 8 default, 1 and 8 possible */
      {1, 9, 0},                                             /* brightness ranges (TODO!) */
      {0, SANE_FIX(0x13f8 * MM_PER_INCH / 600), 0}, {0, SANE_FIX(0x1b9c * MM_PER_INCH / 600), 0}, /* FBF x/y ranges (TODO!) */
      SANE_TRUE, SANE_TRUE, /* duplex ADF, x/y ranges (TODO!) */
      {0, SANE_FIX(0x1390 * MM_PER_INCH / 600), 0}, {0, SANE_FIX(0x20dc * MM_PER_INCH / 600), 0},
  },

};

static int MC_SNMP_Timeout = 2500;
static int MC_Scan_Data_Timeout = 15000;
static int MC_Request_Timeout = 5000;



/****************************************************************************
 *   General configuration parameter definitions
 ****************************************************************************/


/*
 * Definition of the mode_param struct, that is used to
 * specify the valid parameters for the different scan modes.
 *
 * The depth variable gets updated when the bit depth is modified.
 */

static struct mode_param mode_params[] = {
	{0x00, 1, 1},  /* Lineart, 1 color, 1 bit */
	{0x02, 1, 24}, /* Grayscale, 1 color, 24 bit */
	{0x03, 3, 24}  /* Color, 3 colors, 24 bit */
};

static SANE_String_Const mode_list[] = {
	SANE_VALUE_SCAN_MODE_LINEART,
	SANE_VALUE_SCAN_MODE_GRAY,
	SANE_VALUE_SCAN_MODE_COLOR,
	NULL
};

static const SANE_String_Const adf_mode_list[] = {
	SANE_I18N("Simplex"),
	SANE_I18N("Duplex"),
	NULL
};

/* Define the different scan sources */

#define FBF_STR	SANE_I18N("Flatbed")
#define ADF_STR	SANE_I18N("Automatic Document Feeder")

/*
 * source list need one dummy entry (save device settings is crashing).
 * NOTE: no const - this list gets created while exploring the capabilities
 * of the scanner.
 */

static SANE_String_Const source_list[] = {
	FBF_STR,
	NULL,
	NULL,
	NULL
};

/* Some utility functions */

static size_t
max_string_size(const SANE_String_Const strings[])
{
	size_t size, max_size = 0;
	int i;

	for (i = 0; strings[i]; i++) {
		size = strlen(strings[i]) + 1;
		if (size > max_size)
			max_size = size;
	}
	return max_size;
}

static SANE_Status attach_one_usb(SANE_String_Const devname);
static SANE_Status attach_one_net(SANE_String_Const devname, unsigned int device);

static void
print_params(const SANE_Parameters params)
{
	DBG(6, "params.format          = %d\n", params.format);
	DBG(6, "params.last_frame      = %d\n", params.last_frame);
	DBG(6, "params.bytes_per_line  = %d\n", params.bytes_per_line);
	DBG(6, "params.pixels_per_line = %d\n", params.pixels_per_line);
	DBG(6, "params.lines           = %d\n", params.lines);
	DBG(6, "params.depth           = %d\n", params.depth);
}



/****************************************************************************
 *   Low-level Network communication functions
 ****************************************************************************/


#define MAGICOLOR_SNMP_SYSDESCR_OID  ".1.3.6.1.2.1.1.1.0"
#define MAGICOLOR_SNMP_SYSOBJECT_OID ".1.3.6.1.2.1.1.2.0"
#define MAGICOLOR_SNMP_MAC_OID       ".1.3.6.1.2.1.2.2.1.6.1"
#define MAGICOLOR_SNMP_DEVICE_TREE   ".1.3.6.1.4.1.18334.1.1.1.1.1"


/* We don't have a packet wrapper, which holds packet size etc., so we
   don't have to use a *read_raw and a *_read function... */
static int
sanei_magicolor_net_read(struct Magicolor_Scanner *s, unsigned char *buf, size_t wanted,
		       SANE_Status * status)
{
	size_t size, read = 0;
	struct pollfd fds[1];

	*status = SANE_STATUS_GOOD;

	/* poll for data-to-be-read (using a 5 seconds timeout) */
	fds[0].fd = s->fd;
	fds[0].events = POLLIN;
	if (poll (fds, 1, MC_Request_Timeout) <= 0) {
		*status = SANE_STATUS_IO_ERROR;
		return read;
	}

	while (read < wanted) {
		size = sanei_tcp_read(s->fd, buf + read, wanted - read);

		if (size == 0)
			break;

		read += size;
	}

	if (read < wanted)
		*status = SANE_STATUS_IO_ERROR;

	return read;
}

/* We need to optionally pad the buffer with 0x00 to send 64-byte chunks.
   On the other hand, the 0x04 commands don't need this, so we need two
   functions, one *_write function that pads the buffer and then calls
    *_write_raw */
static int
sanei_magicolor_net_write_raw(struct Magicolor_Scanner *s,
			      const unsigned char *buf, size_t buf_size,
			      SANE_Status *status)
{
	sanei_tcp_write(s->fd, buf, buf_size);
	/* TODO: Check whether sending failed... */

	*status = SANE_STATUS_GOOD;
	return buf_size;
}

static int
sanei_magicolor_net_write(struct Magicolor_Scanner *s,
			  const unsigned char *buf, size_t buf_size,
			  SANE_Status *status)
{
	size_t len = 64;
	unsigned char *new_buf = malloc(len);
	if (!new_buf) {
		*status = SANE_STATUS_NO_MEM;
		return 0;
	}
	memset(new_buf, 0x00, len);
	if (buf_size > len)
		buf_size = len;
	if (buf_size)
		memcpy(new_buf, buf, buf_size);
	return sanei_magicolor_net_write_raw (s, new_buf, len, status);
}

static SANE_Status
sanei_magicolor_net_open(struct Magicolor_Scanner *s)
{
	SANE_Status status;
	unsigned char buf[5];

	ssize_t read;
	struct timeval tv;
	struct MagicolorCmd *cmd = s->hw->cmd;

	tv.tv_sec = 5;
	tv.tv_usec = 0;

	setsockopt(s->fd, SOL_SOCKET, SO_RCVTIMEO, (char *)&tv,  sizeof(tv));

	DBG(1, "%s\n", __func__);

	/* the scanner sends a kind of welcome msg */
	read = sanei_magicolor_net_read(s, buf, 3, &status);
	if (read != 3)
		return SANE_STATUS_IO_ERROR;
	if (buf[0] != cmd->net_wrapper_cmd || buf[1] != cmd->net_welcome) {
		DBG (32, "Invalid welcome message received, Expected 0x%02x %02x 00, but got 0x%02x %02x %02x\n",
			cmd->net_wrapper_cmd, cmd->net_welcome, buf[0], buf[1], buf[2]);
		return SANE_STATUS_IO_ERROR;
	} else if (buf[2] != 0x00) {
		/* TODO: Handle response "04 00 01", indicating an error! */
		DBG (32, "Welcome message received, busy status %02x\n", buf[2]);
		/* TODO: Return a human-readable error message (Unable to connect to scanner, scanner is not ready) */
		return SANE_STATUS_DEVICE_BUSY;
	}

	buf[0] = cmd->net_wrapper_cmd;
	buf[1] = cmd->net_lock;
	buf[2] = 0x00;
	/* Copy the device's USB id to bytes 3-4: */
	buf[3] = s->hw->cap->id & 0xff;
	buf[4] = (s->hw->cap->id >> 8) & 0xff;

	DBG(32, "Proper welcome message received, locking the scanner...\n");
	sanei_magicolor_net_write_raw(s, buf, 5, &status);

	read = sanei_magicolor_net_read(s, buf, 3, &status);
	if (read != 3)
		return SANE_STATUS_IO_ERROR;
	if (buf[0] != cmd->net_wrapper_cmd || buf[1] != cmd->net_lock_ack || buf[2] != 0x00) {
		DBG (32, "Welcome message received, Expected 0x%x %x 00, but got 0x%x %x %x\n",
			cmd->net_wrapper_cmd, cmd->net_lock_ack, buf[0], buf[1], buf[2]);
		return SANE_STATUS_IO_ERROR;
	}

	DBG(32, "scanner locked\n");

	return status;
}

static SANE_Status
sanei_magicolor_net_close(struct Magicolor_Scanner *s)
{
	SANE_Status status;
	struct MagicolorCmd *cmd = s->hw->cmd;
	unsigned char buf[3];

	DBG(1, "%s\n", __func__);
	buf[0] = cmd->net_wrapper_cmd;
	buf[1] = cmd->net_unlock;
	buf[2] = 0x00;
	sanei_magicolor_net_write_raw(s, buf, 3, &status);
	return status;
}



/****************************************************************************
 *   Low-level USB communication functions
 ****************************************************************************/

#define SANE_MAGICOLOR_VENDOR_ID	(0x132b)

SANE_Word sanei_magicolor_usb_product_ids[] = {
  0x2089, /* magicolor 1690MF */
  0x2079, /* magicolor 4690MF */
  0				/* last entry - this is used for devices that are specified
				   in the config file as "usb <vendor> <product>" */
};

static int
sanei_magicolor_getNumberOfUSBProductIds (void)
{
  return sizeof (sanei_magicolor_usb_product_ids) / sizeof (SANE_Word);
}




/****************************************************************************
 *   Magicolor low-level communication commands
 ****************************************************************************/

static void dump_hex_buffer_dense (int level, const unsigned char *buf, size_t buf_size)
{
	size_t k;
	char msg[1024], fmt_buf[1024];
	memset (&msg[0], 0x00, 1024);
	memset (&fmt_buf[0], 0x00, 1024);
	for (k = 0; k < min(buf_size, 80); k++) {
		if (k % 16 == 0) {
			if (k>0) {
				DBG (level, "%s\n", msg);
				memset (&msg[0], 0x00, 1024);
			}
			sprintf (fmt_buf, "     0x%04lx  ", (unsigned long)k);
			strcat (msg, fmt_buf);
		}
		if (k % 8 == 0) {
			strcat (msg, " ");
		}
		sprintf (fmt_buf, " %02x" , buf[k]);
		strcat (msg, fmt_buf);
	}
	if (msg[0] != 0 ) {
		DBG (level, "%s\n", msg);
	}
}

/* Create buffers containing the command and arguments. Length of reserved
 * buffer is returned. It's the caller's job to free the buffer! */
static int mc_create_buffer (Magicolor_Scanner *s, unsigned char cmd_type, unsigned char cmd,
		      unsigned char **buf, unsigned char* arg1, size_t len1,
		      SANE_Status *status)
{
	unsigned char* b = NULL;
	size_t buf_len = 2+4+len1+4;
	NOT_USED (s);
	if (len1 <= 0)
		buf_len = 6; /* no args, just cmd + final 0x00 00 00 00 */
	*buf = b = malloc (buf_len);
	memset (b, 0x00, buf_len);
	if (!b) {
		*status = SANE_STATUS_NO_MEM;
		return 0;
	}
	b[0] = cmd_type;
	b[1] = cmd;
	if (len1>0) {
		b[2] = len1 & 0xff;
		b[3] = (len1 >> 8) & 0xff;
		b[4] = (len1 >> 16) & 0xff;
		b[5] = (len1 >> 24) & 0xff;
		if (arg1)
			memcpy(b+6, arg1, len1);
	}
	/* Writing the final 0x00 00 00 00 is not necessary, they are 0x00 already */
	*status = SANE_STATUS_GOOD;
	return buf_len;
}

static int mc_create_buffer2 (Magicolor_Scanner *s, unsigned char cmd_type, unsigned char cmd,
		       unsigned char **buf, unsigned char* arg1, size_t len1,
		       unsigned char* arg2, size_t len2, SANE_Status *status)
{
	unsigned char* b = NULL;
	size_t buf_len = 2+4+len1+4+len2+4;
	/* If any of the two args has size 0, use the simpler mc_create_buffer */
	if (len1<=0)
		return mc_create_buffer (s, cmd_type, cmd, buf, arg2, len2, status);
	else if (len2<=0)
		return mc_create_buffer (s, cmd_type, cmd, buf, arg1, len1, status);
	/* Allocate memory and copy over args and their lengths */
	*buf = b = malloc (buf_len);
	if (!b) {
		*status = SANE_STATUS_NO_MEM;
		return 0;
	}
	memset (b, 0x00, buf_len);
	b[0] = cmd_type;
	b[1] = cmd;
	/* copy over the argument length in lower endian */
	b[2] = len1 & 0xff;
	b[3] = (len1 >> 8) & 0xff;
	b[4] = (len1 >> 16) & 0xff;
	b[5] = (len1 >> 24) & 0xff;
	if (arg1) {
		/* Copy the arguments */
		memcpy(b+6, arg1, len1);
	}
	/* copy over the second argument length in little endian */
	b[6+len1] = len2 & 0xff;
	b[7+len1] = (len2 >> 8) & 0xff;
	b[8+len1] = (len2 >> 16) & 0xff;
	b[9+len1] = (len2 >> 24) & 0xff;
	if (arg2) {
		memcpy(b+10+len1, arg2, len2);
	}
	*status = SANE_STATUS_GOOD;
	return buf_len;
}

static int
mc_send(Magicolor_Scanner * s, void *buf, size_t buf_size, SANE_Status * status)
{
	DBG(15, "%s: size = %lu\n", __func__, (u_long) buf_size);

	if (DBG_LEVEL >= 125) {
		const unsigned char *s = buf;
		DBG(125, "Cmd: 0x%02x %02x, complete buffer:\n", s[0], s[1]);
		dump_hex_buffer_dense (125, s, buf_size);
	}

	if (s->hw->connection == SANE_MAGICOLOR_NET) {
		return sanei_magicolor_net_write(s, buf, buf_size, status);
	} else if (s->hw->connection == SANE_MAGICOLOR_USB) {
		size_t n;
		n = buf_size;
		*status = sanei_usb_write_bulk(s->fd, buf, &n);
		DBG(125, "USB: wrote %lu bytes, status: %s\n", (unsigned long)n, sane_strstatus(*status));
		return n;
	}

	*status = SANE_STATUS_INVAL;
	return 0;
	/* never reached */
}

static ssize_t
mc_recv(Magicolor_Scanner * s, void *buf, ssize_t buf_size,
	    SANE_Status * status)
{
	ssize_t n = 0;

	DBG(15, "%s: size = %ld, buf = %p\n", __func__, (long) buf_size, buf);

	if (s->hw->connection == SANE_MAGICOLOR_NET) {
		n = sanei_magicolor_net_read(s, buf, buf_size, status);
	} else if (s->hw->connection == SANE_MAGICOLOR_USB) {
		/* !!! only report an error if we don't read anything */
		n = buf_size;	/* buf_size gets overwritten */
		*status =
			sanei_usb_read_bulk(s->fd, (SANE_Byte *) buf,
					    (size_t *) & n);

		if (n > 0)
			*status = SANE_STATUS_GOOD;
	}

	if (n < buf_size) {
		DBG(1, "%s: expected = %lu, got = %ld\n", __func__,
		    (u_long) buf_size, (long) n);
		*status = SANE_STATUS_IO_ERROR;
	}

	/* dump buffer if appropriate */
	if (DBG_LEVEL >= 127 && n > 0) {
		const unsigned char* b=buf;
		dump_hex_buffer_dense (125, b, buf_size);
	}

	return n;
}

/* Simple function to exchange a fixed amount of
 * data with the scanner
 */
static SANE_Status
mc_txrx(Magicolor_Scanner * s, unsigned char *txbuf, size_t txlen,
	    unsigned char *rxbuf, size_t rxlen)
{
	SANE_Status status;

	mc_send(s, txbuf, txlen, &status);
	if (status != SANE_STATUS_GOOD) {
		DBG(1, "%s: tx err, %s\n", __func__, sane_strstatus(status));
		return status;
	}

	mc_recv(s, rxbuf, rxlen, &status);
	if (status != SANE_STATUS_GOOD) {
		DBG(1, "%s: rx err, %s\n", __func__, sane_strstatus(status));
	}

	return status;
}





/****************************************************************************
 *   Magicolor high-level communication commands
 ****************************************************************************/


/** 0x03 09 01 - Request last error
 * <- Information block (0x00 for OK, 0x01 for ERROR)
 */
static SANE_Status
cmd_request_error (SANE_Handle handle)
{
	Magicolor_Scanner *s = (Magicolor_Scanner *) handle;
	SANE_Status status;
	unsigned char params[1];
	unsigned char *buf;
	size_t buflen;

	DBG(8, "%s\n", __func__);

	if (s->hw->cmd->request_status == 0)
		return SANE_STATUS_UNSUPPORTED;

	buflen = mc_create_buffer (s, s->hw->cmd->scanner_cmd, s->hw->cmd->request_error,
				   &buf, NULL, 1, &status);
	if (buflen <= 0 ) {
		return SANE_STATUS_NO_MEM;
	} else if (status != SANE_STATUS_GOOD) {
		return status;
	}

	status = mc_txrx (s, buf, buflen, params, 1);
	free(buf);
	if (status != SANE_STATUS_GOOD)
		return status;

	DBG(1, "status: %02x\n", params[0]);

	switch (params[0]) {
		case STATUS_READY:
			DBG(1, " ready\n");
			break;
		case STATUS_ADF_JAM:
			DBG(1, " paper jam in ADF\n");
			return SANE_STATUS_JAMMED;
			break;
		case STATUS_OPEN:
			DBG(1, " printer door open or waiting for button press\n");
			return SANE_STATUS_COVER_OPEN;
			break;
		case STATUS_NOT_READY:
			DBG(1, " scanner not ready (in use on another interface or warming up)\n");
			return SANE_STATUS_DEVICE_BUSY;
			break;
		default:
			DBG(1, " unknown status 0x%x\n", params[0]);
	}
	return status;
}

/** 0x03 0d  - Request status command */
static SANE_Status
cmd_request_status(SANE_Handle handle, unsigned char *b)
{
	Magicolor_Scanner *s = (Magicolor_Scanner *) handle;
	SANE_Status status;
	unsigned char *buf;
	size_t buflen;

	DBG(8, "%s\n", __func__);
	if (!b) {
		DBG(1, "%s called with NULL buffer\n", __func__);
		return SANE_STATUS_INVAL;
	}
	memset (b, 0x00, 0x0b); /* initialize all 0x0b bytes with 0 */
	buflen = mc_create_buffer (s, s->hw->cmd->scanner_cmd, s->hw->cmd->request_status,
				   &buf, NULL, 0x0b, &status);
	if (buflen <= 0 ) {
		return SANE_STATUS_NO_MEM;
	} else if (status != SANE_STATUS_GOOD) {
		return status;
	}

	status = mc_txrx (s, buf, buflen, b, 0x0b);
	free (buf);
	if (status != SANE_STATUS_GOOD)
		DBG(8, "%s: Status NOT successfully retrieved\n", __func__);
	else {
		DBG(8, "%s: Status successfully retrieved:\n", __func__);
		/* TODO: debug output of the returned parameters... */
		DBG (11, "  ADF status: 0x%02x", b[1]);
		if (b[1] & ADF_LOADED) {
			DBG (11, " loaded\n");
		} else {
			DBG (11, " not loaded\n");
		}
	}
	return status;
}


/** 0x03 08  - Start scan command */
static SANE_Status
cmd_start_scan (SANE_Handle handle, size_t value)
{
	Magicolor_Scanner *s = (Magicolor_Scanner *) handle;
	SANE_Status status;
	unsigned char params1[4], params2[1];
	unsigned char *buf;
	size_t buflen;

	DBG(8, "%s\n", __func__);
	/* Copy params to buffers */
	/* arg1 is expected returned bytes per line, 4-byte little endian */
	/* arg2 is unknown, seems to be always 0x00 */
	params1[0] = value & 0xff;
	params1[1] = (value >> 8) & 0xff;
	params1[2] = (value >> 16) & 0xff;
	params1[3] = (value >> 24) & 0xff;

	params2[0] = 0x00;
	buflen = mc_create_buffer2 (s, s->hw->cmd->scanner_cmd, s->hw->cmd->start_scanning,
				    &buf, params1, 4, params2, 1, &status);
	if (buflen <= 0 ) {
		return SANE_STATUS_NO_MEM;
	} else if (status != SANE_STATUS_GOOD) {
		return status;
	}

	mc_send(s, buf, buflen, &status);
	free (buf);
	if (status != SANE_STATUS_GOOD)
		DBG(8, "%s: Data NOT successfully sent\n", __func__);
	else
		DBG(8, "%s: Data successfully sent\n", __func__);
	return status;
}

/** 0x03 0a  - Cancel(?) Scan command */
/* TODO: Does this command really mean CANCEL??? */
static SANE_Status
cmd_cancel_scan (SANE_Handle handle)
{
	Magicolor_Scanner *s = (Magicolor_Scanner *) handle;
	SANE_Status status;
	unsigned char *buf;
	size_t buflen;

	DBG(8, "%s\n", __func__);
	buflen = mc_create_buffer (s, s->hw->cmd->scanner_cmd, s->hw->cmd->stop_scanning,
				    &buf, NULL, 0, &status);
	if (buflen <= 0 ) {
		return SANE_STATUS_NO_MEM;
	} else if (status != SANE_STATUS_GOOD) {
		return status;
	}

	mc_send(s, buf, buflen, &status);
	free (buf);
	if (status != SANE_STATUS_GOOD)
		DBG(8, "%s: Data NOT successfully sent\n", __func__);
	else
		DBG(8, "%s: Data successfully sent\n", __func__);
	return status;
}

/** 0x03 12  - Finish(?) scan command */
/* TODO: Does this command really mean FINISH??? */
static SANE_Status
cmd_finish_scan (SANE_Handle handle)
{
	Magicolor_Scanner *s = (Magicolor_Scanner *) handle;
	SANE_Status status;
	unsigned char *buf, returned[0x0b];
	size_t buflen;

	DBG(8, "%s\n", __func__);
	buflen = mc_create_buffer (s, s->hw->cmd->scanner_cmd, s->hw->cmd->unknown2,
				    &buf, NULL, 0x0b, &status);
	if (buflen <= 0 ) {
		return SANE_STATUS_NO_MEM;
	} else if (status != SANE_STATUS_GOOD) {
		return status;
	}
	memset (&returned[0], 0x00, 0x0b);

	status = mc_txrx (s, buf, buflen, returned, 0x0b);
	free (buf);
	if (status != SANE_STATUS_GOOD)
		DBG(8, "%s: Data NOT successfully sent\n", __func__);
	else
		DBG(8, "%s: Data successfully sent\n", __func__);
	return status;
}

/** 0x03 0b  - Get scanning parameters command
 *    input buffer seems to be 0x00 always */
static SANE_Status
cmd_get_scanning_parameters(SANE_Handle handle,
			    SANE_Frame *format, SANE_Int *depth,
			    SANE_Int *data_pixels, SANE_Int *pixels_per_line,
			    SANE_Int *lines)
{
	Magicolor_Scanner *s = (Magicolor_Scanner *) handle;
	SANE_Status status;
	unsigned char *txbuf, rxbuf[8];
	size_t buflen;
	NOT_USED (format);
	NOT_USED (depth);

	DBG(8, "%s\n", __func__);
	buflen = mc_create_buffer (s, s->hw->cmd->scanner_cmd,
				   s->hw->cmd->request_scan_parameters,
				   &txbuf, NULL, 8, &status);
	if (buflen <= 0 ) {
		return SANE_STATUS_NO_MEM;
	} else if (status != SANE_STATUS_GOOD) {
		return status;
	}

	status = mc_txrx (s, txbuf, buflen, rxbuf, 8);
	free (txbuf);
	if (status != SANE_STATUS_GOOD)
		DBG(8, "%s: Parameters NOT successfully retrieved\n", __func__);
	else {
		DBG(8, "%s: Parameters successfully retrieved\n", __func__);

		/* Assign px_per_line and lines. Bytes 7-8 must match 3-4 */
		if (rxbuf[2]!=rxbuf[6] || rxbuf[3]!=rxbuf[7]) {
			DBG (1, "%s: ERROR: Returned image parameters indicate an "
				"unsupported device: Bytes 3-4 do not match "
				"bytes 7-8! Trying to continue with bytes 3-4.\n",
				__func__);
			dump_hex_buffer_dense (1, rxbuf, 8);
		}
		/* Read returned values, encoded in 2-byte little endian */
		*data_pixels = rxbuf[1] * 0x100 + rxbuf[0];
		*lines = rxbuf[3] * 0x100 + rxbuf[2];
		*pixels_per_line = rxbuf[5] * 0x100 + rxbuf[4];
		DBG (8, "%s: data_pixels = 0x%x (%u), lines = 0x%x (%u), "
		        "pixels_per_line = 0x%x (%u)\n", __func__,
		        *data_pixels, *data_pixels,
		        *lines, *lines,
		        *pixels_per_line, *pixels_per_line);

		/*
		 * SECURITY REMEDIATION
		 * See gitlab issue #279 - Issue10 SIGFPE in mc_setup_block_mode
		 *
		 * pixels_per_line cannot be zero, otherwise a division by zero error can occur later.
		 * Added checking the parameters to ensure that this issue cannot occur.
		 *
		 * Additionally to the reported issue, it makes no sense for any of the values of
		 * data_pixels, lines or pixels_per_line to be zero. I do not have any knowledge
		 * of valid maximums for these parameters.
		 *
		 */
		if ((*data_pixels == 0) || (*lines == 0) || (*pixels_per_line == 0)) {
			DBG (1, "%s: ERROR: Returned image parameters contain invalid "
				"bytes. Zero values for these parameters are not rational.\n",
				__func__);
			dump_hex_buffer_dense (1, rxbuf, 8);
			return SANE_STATUS_INVAL;
		}
	}

	return status;
}

/** 0x03 0c  - Set scanning parameters command */
static SANE_Status
cmd_set_scanning_parameters(SANE_Handle handle,
	unsigned char resolution, unsigned char color_mode,
	unsigned char brightness, unsigned char contrast,
	int tl_x, int tl_y, int width, int height, unsigned char source)
{
	Magicolor_Scanner *s = (Magicolor_Scanner *) handle;
	SANE_Status status;
	unsigned char param[0x11];
	unsigned char *buf;
	size_t buflen;

	DBG(8, "%s\n", __func__);
	/* Copy over the params to the param byte array */
	/* Byte structure:
	 *   byte 0:     resolution
	 *   byte 1:     color mode
	 *   byte 2:     brightness
	 *   byte 3:     0xff
	 *   byte 4-5:   x-start
	 *   byte 6-7:   y-start
	 *   byte 8-9:  x-extent
	 *   byte 10-11: y-extent
	 *   byte 12:    source (ADF/FBF)
	 **/
	memset (&param[0], 0x00, 0x11);
	param[0] = resolution;
	param[1] = color_mode;
	param[2] = brightness;
	param[3] = contrast | 0xff; /* TODO: Always 0xff? What about contrast? */
	/* Image coordinates are encoded 2-byte little endian: */
	param[4] = tl_x & 0xff;
	param[5] = (tl_x >> 8) & 0xff;
	param[6] = tl_y & 0xff;
	param[7] = (tl_y >> 8) & 0xff;
	param[8] = width & 0xff;
	param[9] = (width >> 8) & 0xff;
	param[10] = height & 0xff;
	param[11] = (height >> 8) & 0xff;

	param[12] = source;

	/* dump buffer if appropriate */
	DBG (127, "  Scanning parameter buffer:");
	dump_hex_buffer_dense (127, param, 0x11);

	buflen = mc_create_buffer (s, s->hw->cmd->scanner_cmd, s->hw->cmd->set_scan_parameters,
				   &buf, param, 0x11, &status);
	if (buflen <= 0 ) {
		return SANE_STATUS_NO_MEM;
	} else if (status != SANE_STATUS_GOOD) {
		return status;
	}

	mc_send(s, buf, buflen, &status);
	free (buf);
	if (status != SANE_STATUS_GOOD)
		DBG(8, "%s: Data NOT successfully sent\n", __func__);
	else
		DBG(8, "%s: Data successfully sent\n", __func__);
	return status;
}

/** 0x03 ??  - Request push button status command */
#if 0
static SANE_Status
cmd_request_push_button_status(SANE_Handle handle, unsigned char *bstatus)
{
	Magicolor_Scanner *s = (Magicolor_Scanner *) handle;
	SANE_Status status;
	unsigned char *buf;
	size_t buflen;

	DBG(8, "%s\n", __func__);


	if (s->hw->cmd->unknown1 == 0)
		return SANE_STATUS_UNSUPPORTED;

	DBG(8, "%s: Supported\n", __func__);
	memset (bstatus, 0x00, 1);
	buflen = mc_create_buffer (s, s->hw->cmd->scanner_cmd, s->hw->cmd->unknown1,
				   &buf, bstatus, 1, &status);
	if (buflen <= 0 ) {
		return SANE_STATUS_NO_MEM;
	} else if (status != SANE_STATUS_GOOD) {
		return status;
	}

	status = mc_txrx (s, buf, buflen, bstatus, 1);
	free(buf);
	if (status != SANE_STATUS_GOOD)
		return status;

	DBG(1, "push button status: %02x ", bstatus[0]);
	switch (bstatus[0]) {
		/* TODO: What's the response code for button pressed??? */
		default:
			DBG(1, " unknown\n");
			status = SANE_STATUS_UNSUPPORTED;
	}
	return status;
}
#endif

/** 0x03 0e  - Read data command */
static SANE_Status
cmd_read_data (SANE_Handle handle, unsigned char *buf, size_t len)
{
	Magicolor_Scanner *s = (Magicolor_Scanner *) handle;
	SANE_Status status;
	unsigned char *txbuf;
	unsigned char param[4];
	size_t txbuflen;
	int oldtimeout = MC_Request_Timeout;

	DBG(8, "%s\n", __func__);
	param[0] = len & 0xff;
	param[1] = (len >> 8) & 0xff;
	param[2] = (len >> 16) & 0xff;
	param[3] = (len >> 24) & 0xff;

	txbuflen = mc_create_buffer (s, s->hw->cmd->scanner_cmd, s->hw->cmd->request_data,
				   &txbuf, param, 4, &status);
	if (txbuflen <= 0 ) {
		return SANE_STATUS_NO_MEM;
	} else if (status != SANE_STATUS_GOOD) {
		return status;
	}

	/* Temporarily set the poll timeout to 10 seconds instead of 2,
	 * because a color scan needs >5 seconds to initialize. */
	MC_Request_Timeout = MC_Scan_Data_Timeout;
	status = mc_txrx (s, txbuf, txbuflen, buf, len);
	MC_Request_Timeout = oldtimeout;
	free (txbuf);
	if (status != SANE_STATUS_GOOD)
		DBG(8, "%s: Image data NOT successfully retrieved\n", __func__);
	else {
		DBG(8, "%s: Image data successfully retrieved\n", __func__);
	}

	return status;
}



/* TODO: 0x03 0f command (unknown), 0x03 10 command (set button wait) */




/****************************************************************************
 *   Magicolor backend high-level operations
 ****************************************************************************/


static void
mc_dev_init(Magicolor_Device *dev, const char *devname, int conntype)
{
	DBG(5, "%s\n", __func__);

	dev->name = NULL;
	dev->model = NULL;
	dev->connection = conntype;
	dev->sane.name = devname;
	dev->sane.model = NULL;
	dev->sane.type = "flatbed scanner";
	dev->sane.vendor = "Magicolor";
	dev->cap = &magicolor_cap[MAGICOLOR_CAP_DEFAULT];
	dev->cmd = &magicolor_cmd[MAGICOLOR_LEVEL_DEFAULT];
	/* Change default level when using a network connection */
	if (dev->connection == SANE_MAGICOLOR_NET)
		dev->cmd = &magicolor_cmd[MAGICOLOR_LEVEL_NET];
}

static SANE_Status
mc_dev_post_init(struct Magicolor_Device *dev)
{
	DBG(5, "%s\n", __func__);
	NOT_USED (dev);
	/* Correct device parameters if needed */
	return SANE_STATUS_GOOD;
}

static SANE_Status
mc_set_model(Magicolor_Scanner * s, const char *model, size_t len)
{
	unsigned char *buf;
	unsigned char *p;
	struct Magicolor_Device *dev = s->hw;

	buf = malloc(len + 1);
	if (buf == NULL)
		return SANE_STATUS_NO_MEM;

	memcpy(buf, model, len);
	buf[len] = '\0';

	p = &buf[len - 1];

	while (*p == ' ') {
		*p = '\0';
		p--;
	}

	if (dev->model)
		free(dev->model);

	dev->model = strndup((const char *) buf, len);
	dev->sane.model = dev->model;
	DBG(10, "%s: model is '%s'\n", __func__, dev->model);

	free(buf);

	return SANE_STATUS_GOOD;
}

static void
mc_set_device (SANE_Handle handle, unsigned int device)
{
	Magicolor_Scanner *s = (Magicolor_Scanner *) handle;
	Magicolor_Device *dev = s->hw;
	const char* cmd_level;
	int n;

	DBG(1, "%s: 0x%x\n", __func__, device);

	for (n = 0; n < NELEMS (magicolor_cap); n++) {
		if (magicolor_cap[n].id == device)
			break;
	}
	if (n < NELEMS(magicolor_cap)) {
		dev->cap = &magicolor_cap[n];
	} else {
		dev->cap = &magicolor_cap[MAGICOLOR_CAP_DEFAULT];
		DBG(1, " unknown device 0x%x, using default %s\n",
		    device, dev->cap->model);
	}
	mc_set_model (s, dev->cap->model, strlen (dev->cap->model));

	cmd_level = dev->cap->cmds;
	/* set command type and level */
	for (n = 0; n < NELEMS(magicolor_cmd); n++) {
		if (!strcmp(cmd_level, magicolor_cmd[n].level))
			break;
	}

	if (n < NELEMS(magicolor_cmd)) {
		dev->cmd = &magicolor_cmd[n];
	} else {
		dev->cmd = &magicolor_cmd[MAGICOLOR_LEVEL_DEFAULT];
		DBG(1, " unknown command level %s, using %s\n",
		    cmd_level, dev->cmd->level);
	}
}

static SANE_Status
mc_discover_capabilities(Magicolor_Scanner *s)
{
	SANE_Status status;
	Magicolor_Device *dev = s->hw;

	SANE_String_Const *source_list_add = source_list;

	DBG(5, "%s\n", __func__);

	/* always add flatbed */
	*source_list_add++ = FBF_STR;
	/* TODO: How can I check for existence of an ADF??? */
	if (dev->cap->ADF)
		*source_list_add++ = ADF_STR;

	/* TODO: Is there any capability that we can extract from the
	 *       device by some scanne command? So far, it looks like
	 *       the device does not support any reporting. I don't even
	 *       see a way to determine which device we are talking to!
	 */


	/* request error status */
	status = cmd_request_error(s);
	if (status != SANE_STATUS_GOOD)
		return status;

	dev->x_range = &dev->cap->fbf_x_range;
	dev->y_range = &dev->cap->fbf_y_range;

	DBG(5, "   x-range: %f %f\n", SANE_UNFIX(dev->x_range->min), SANE_UNFIX(dev->x_range->max));
	DBG(5, "   y-range: %f %f\n", SANE_UNFIX(dev->y_range->min), SANE_UNFIX(dev->y_range->max));

	DBG(5, "End of %s, status:%s\n", __func__, sane_strstatus(status));
	*source_list_add = NULL; /* add end marker to source list */
	return status;
}

static SANE_Status
mc_setup_block_mode (Magicolor_Scanner *s)
{
	/* block_len should always be a multiple of bytes_per_line, so
	 * we retrieve only whole lines at once */
	s->block_len = (int)(0xff00/s->scan_bytes_per_line) * s->scan_bytes_per_line;
	s->blocks = s->data_len / s->block_len;
	s->last_len = s->data_len - (s->blocks * s->block_len);
	if (s->last_len>0)
		s->blocks++;
	DBG(5, "%s: block_len=0x%x, last_len=0x%0x, blocks=%d\n", __func__, s->block_len, s->last_len, s->blocks);
	s->counter = 0;
	s->bytes_read_in_line = 0;
	if (s->line_buffer)
		free(s->line_buffer);
	s->line_buffer = malloc(s->scan_bytes_per_line);
	if (s->line_buffer == NULL) {
		DBG(1, "out of memory (line %d)\n", __LINE__);
		return SANE_STATUS_NO_MEM;
	}


	DBG (5, " %s: Setup block mode - scan_bytes_per_line=%d, pixels_per_line=%d, depth=%d, data_len=%x, block_len=%x, blocks=%d, last_len=%x\n",
		__func__, s->scan_bytes_per_line, s->params.pixels_per_line, s->params.depth, s->data_len, s->block_len, s->blocks, s->last_len);
	return SANE_STATUS_GOOD;
}

/* Call the 0x03 0c command to set scanning parameters from the s->opt list */
static SANE_Status
mc_set_scanning_parameters(Magicolor_Scanner * s)
{
	SANE_Status status;
	unsigned char rs, source, brightness;
	struct mode_param *mparam = &mode_params[s->val[OPT_MODE].w];
	SANE_Int scan_pixels_per_line = 0;

	DBG(1, "%s\n", __func__);

	/* Find the resolution in the res list and assign the index to buf[1] */
	for (rs=0; rs < s->hw->cap->res_list_size; rs++ ) {
		if ( s->val[OPT_RESOLUTION].w == s->hw->cap->res_list[rs] )
			break;
	}

	if (SANE_OPTION_IS_ACTIVE(s->opt[OPT_BRIGHTNESS].cap)) {
		brightness = s->val[OPT_BRIGHTNESS].w;
	} else {
		brightness = 5;
	}

	/* ADF used? */
	if (strcmp(source_list[s->val[OPT_SOURCE].w], ADF_STR) == 0) {
		/* Use ADF */
		if (s->val[OPT_ADF_MODE].w == 0) {
			source = 0x01;
		} else {
			/* Use duplex */
			source = 0x02;
		}
	} else {
		source = 0x00;
	}

	/* TODO: Any way to set PREVIEW??? */

	/* Remaining bytes unused */
	status = cmd_set_scanning_parameters(s,
					     rs, mparam->flags,  /* res, color mode */
					     brightness, 0xff, /* brightness, contrast? */
					     s->left, s->top,  /* top/left start */
					     s->width, s->height, /* extent */
					     source); /* source */

	if (status != SANE_STATUS_GOOD)
		DBG (2, "%s: Command cmd_set_scanning_parameters failed, %s\n",
		     __func__, sane_strstatus(status));

	/* Now query the scanner for the current image parameters */
	status = cmd_get_scanning_parameters (s,
			&s->params.format, &s->params.depth,
			&scan_pixels_per_line,
			&s->params.pixels_per_line, &s->params.lines);
	if (status != SANE_STATUS_GOOD) {
		DBG (2, "%s: Command cmd_get_scanning_parameters failed, %s\n",
		     __func__, sane_strstatus(status));
		return status;
	}

	/* Calculate how many bytes are really used per line */
	s->params.bytes_per_line = ceil (s->params.pixels_per_line * s->params.depth / 8.0);
	if (s->val[OPT_MODE].w == MODE_COLOR)
		s->params.bytes_per_line *= 3;

	/* Calculate how many bytes per line will be returned by the scanner.
	 * The values needed for this are returned by get_scannign_parameters */
	s->scan_bytes_per_line = ceil (scan_pixels_per_line * s->params.depth / 8.0);
	if (s->val[OPT_MODE].w == MODE_COLOR) {
		s->scan_bytes_per_line *= 3;
	}
	s->data_len = s->params.lines * s->scan_bytes_per_line;

	status = mc_setup_block_mode (s);
	if (status != SANE_STATUS_GOOD)
		DBG (2, "%s: Command mc_setup_block_mode failed, %s\n",
		     __func__, sane_strstatus(status));

	DBG (1, "%s: bytes_read  in line: %d\n", __func__, s->bytes_read_in_line);

	return status;
}

static SANE_Status
mc_check_adf(Magicolor_Scanner * s)
{
	SANE_Status status;
	unsigned char buf[0x0b];

	DBG(5, "%s\n", __func__);

	status = cmd_request_status(s, buf);
	if (status != SANE_STATUS_GOOD)
		return status;

	if (!(buf[1] & ADF_LOADED))
		return SANE_STATUS_NO_DOCS;

	/* TODO: Check for jam in ADF */
	return SANE_STATUS_GOOD;
}

static SANE_Status
mc_scan_finish(Magicolor_Scanner * s)
{
	SANE_Status status;
	DBG(5, "%s\n", __func__);

	/* If we have not yet read all data, cancel the scan */
	if (s->buf && !s->eof)
		status = cmd_cancel_scan (s);

	if (s->line_buffer)
		free (s->line_buffer);
	s->line_buffer = NULL;
	free(s->buf);
	s->buf = s->end = s->ptr = NULL;

	/* TODO: Any magicolor command for "scan finished"? */
	status = cmd_finish_scan (s);

	status = cmd_request_error(s);
	if (status != SANE_STATUS_GOOD) {
		cmd_cancel_scan (s);
		return status;
        }

	/* XXX required? */
	/* TODO:	cmd_reset(s);*/
	return SANE_STATUS_GOOD;
}

static void
mc_copy_image_data(Magicolor_Scanner * s, SANE_Byte * data, SANE_Int max_length,
		   SANE_Int * length)
{
	DBG (1, "%s: bytes_read  in line: %d\n", __func__, s->bytes_read_in_line);
	if (s->params.format == SANE_FRAME_RGB) {
		SANE_Int bytes_available, scan_pixels_per_line = s->scan_bytes_per_line/3;
		*length = 0;

		while ((max_length >= s->params.bytes_per_line) && (s->ptr < s->end)) {
			SANE_Int bytes_to_copy = s->scan_bytes_per_line - s->bytes_read_in_line;
			/* First, fill the line buffer for the current line: */
			bytes_available = (s->end - s->ptr);
			/* Don't copy more than we have buffer and available */
			if (bytes_to_copy > bytes_available)
				bytes_to_copy = bytes_available;

			if (bytes_to_copy > 0) {
				memcpy (s->line_buffer + s->bytes_read_in_line, s->ptr, bytes_to_copy);
				s->ptr += bytes_to_copy;
				s->bytes_read_in_line += bytes_to_copy;
			}

			/* We have filled as much as possible of the current line
			 * with data from the scanner. If we have a complete line,
			 * copy it over. */
			if ((s->bytes_read_in_line >= s->scan_bytes_per_line) &&
			    (s->params.bytes_per_line <= max_length))
			{
				SANE_Int i;
				SANE_Byte *line = s->line_buffer;
				*length += s->params.bytes_per_line;
				for (i=0; i< s->params.pixels_per_line; ++i) {
					*data++ = line[0];
					*data++ = line[scan_pixels_per_line];
					*data++ = line[2 * scan_pixels_per_line];
					line++;
				}
				max_length -= s->params.bytes_per_line;
				s->bytes_read_in_line -= s->scan_bytes_per_line;
			}
		}

	} else {
		/* B/W and Grayscale use the same structure, so we use the same code */
		SANE_Int bytes_available;
		*length = 0;

		while ((max_length != 0) && (s->ptr < s->end)) {
			SANE_Int bytes_to_skip, bytes_to_copy;
			bytes_available = (s->end - s->ptr);
			bytes_to_copy = s->params.bytes_per_line - s->bytes_read_in_line;
			bytes_to_skip = s->scan_bytes_per_line - s->bytes_read_in_line;

			/* Don't copy more than we have buffer */
			if (bytes_to_copy > max_length) {
				bytes_to_copy = max_length;
				bytes_to_skip = max_length;
			}

			/* Don't copy/skip more bytes than we have read in */
			if (bytes_to_copy > bytes_available)
				bytes_to_copy = bytes_available;
			if (bytes_to_skip > bytes_available)
				bytes_to_skip = bytes_available;

			if (bytes_to_copy > 0) {
				/* we have not yet copied all pixels of the line */
				memcpy (data, s->ptr, bytes_to_copy);
				max_length -= bytes_to_copy;
				*length += bytes_to_copy;
				data += bytes_to_copy;
			}
			if (bytes_to_skip > 0) {
				s->ptr += bytes_to_skip;
				s->bytes_read_in_line += bytes_to_skip;
			}
			if (s->bytes_read_in_line >= s->scan_bytes_per_line)
				s->bytes_read_in_line -= s->scan_bytes_per_line;

		}
	}
}

static SANE_Status
mc_init_parameters(Magicolor_Scanner * s)
{
	int dpi, optres;

	DBG(5, "%s\n", __func__);

	memset(&s->params, 0, sizeof(SANE_Parameters));

	dpi = s->val[OPT_RESOLUTION].w;
	optres = s->hw->cap->optical_res;

	if (SANE_UNFIX(s->val[OPT_BR_Y].w) == 0 ||
		SANE_UNFIX(s->val[OPT_BR_X].w) == 0)
		return SANE_STATUS_INVAL;

	/* TODO: Use OPT_RESOLUTION or fixed 600dpi for left/top/width/height? */
	s->left = ((SANE_UNFIX(s->val[OPT_TL_X].w) / MM_PER_INCH) * optres) + 0.5;

	s->top = ((SANE_UNFIX(s->val[OPT_TL_Y].w) / MM_PER_INCH) * optres) + 0.5;

	s->width =
		((SANE_UNFIX(s->val[OPT_BR_X].w -
			   s->val[OPT_TL_X].w) / MM_PER_INCH) * optres) + 0.5;

	s->height =
		((SANE_UNFIX(s->val[OPT_BR_Y].w -
			   s->val[OPT_TL_Y].w) / MM_PER_INCH) * optres) + 0.5;

	s->params.pixels_per_line = s->width * dpi / optres + 0.5;
	s->params.lines = s->height * dpi / optres + 0.5;


	DBG(1, "%s: resolution = %d, preview = %d\n",
		__func__, dpi, s->val[OPT_PREVIEW].w);

	DBG(1, "%s: %p %p tlx %f tly %f brx %f bry %f [mm]\n",
	    __func__, (void *) s, (void *) s->val,
	    SANE_UNFIX(s->val[OPT_TL_X].w), SANE_UNFIX(s->val[OPT_TL_Y].w),
	    SANE_UNFIX(s->val[OPT_BR_X].w), SANE_UNFIX(s->val[OPT_BR_Y].w));

	/*
	 * The default color depth is stored in mode_params.depth:
	 */
	DBG(1, " %s, vor depth\n", __func__);

	if (mode_params[s->val[OPT_MODE].w].depth == 1)
		s->params.depth = 1;
	else
		s->params.depth = s->val[OPT_BIT_DEPTH].w;

	s->params.last_frame = SANE_TRUE;

	s->params.bytes_per_line = ceil (s->params.depth * s->params.pixels_per_line / 8.0);

	switch (s->val[OPT_MODE].w) {
	case MODE_BINARY:
	case MODE_GRAY:
		s->params.format = SANE_FRAME_GRAY;
		break;
	case MODE_COLOR:
		s->params.format = SANE_FRAME_RGB;
		s->params.bytes_per_line *= 3;
		break;
	}


	DBG(1, "%s: Parameters are format=%d, bytes_per_line=%d, lines=%d\n", __func__, s->params.format, s->params.bytes_per_line, s->params.lines);
	return (s->params.lines > 0) ? SANE_STATUS_GOOD : SANE_STATUS_INVAL;
}

static SANE_Status
mc_start_scan(Magicolor_Scanner * s)
{
	SANE_Status status = cmd_start_scan (s, s->data_len);
	if (status != SANE_STATUS_GOOD ) {
		DBG (1, "%s: starting the scan failed (%s)\n", __func__, sane_strstatus(status));
	}
	return status;
}

static SANE_Status
mc_read(struct Magicolor_Scanner *s)
{
	SANE_Status status = SANE_STATUS_GOOD;
	ssize_t buf_len = 0;

	/* did we passed everything we read to sane? */
	if (s->ptr == s->end) {

		if (s->eof)
			return SANE_STATUS_EOF;

		s->counter++;
		buf_len = s->block_len;

		if (s->counter == s->blocks && s->last_len)
			buf_len = s->last_len;

		DBG(18, "%s: block %d/%d, size %lu\n", __func__,
			s->counter, s->blocks,
			(unsigned long) buf_len);

		/* receive image data + error code */
		status = cmd_read_data (s, s->buf, buf_len);
		if (status != SANE_STATUS_GOOD) {
			DBG (1, "%s: Receiving image data failed (%s)\n",
					__func__, sane_strstatus(status));
			cmd_cancel_scan(s);
			return status;
		}

		DBG(18, "%s: successfully read %lu bytes\n", __func__, (unsigned long) buf_len);

		if (s->counter < s->blocks) {
			if (s->canceling) {
				cmd_cancel_scan(s);
				return SANE_STATUS_CANCELLED;
			}
		} else
			s->eof = SANE_TRUE;

		s->end = s->buf + buf_len;
		s->ptr = s->buf;
	}

	return status;
}




/****************************************************************************
 *   SANE API implementation (high-level functions)
 ****************************************************************************/


#if HAVE_LIBSNMP
static struct MagicolorCap *
mc_get_device_from_identification (const char*ident)
{
	int n;
	for (n = 0; n < NELEMS (magicolor_cap); n++) {
		if ((strcmp (magicolor_cap[n].model, ident) == 0) || (strcmp (magicolor_cap[n].OID, ident) == 0))
		{
			return &magicolor_cap[n];
		}
	}
	return NULL;
}
#endif


/*
 * close_scanner()
 *
 * Close the open scanner. Depending on the connection method, a different
 * close function is called.
 */
static void
close_scanner(Magicolor_Scanner *s)
{
	DBG(7, "%s: fd = %d\n", __func__, s->fd);

	if (s->fd == -1)
		return;

	mc_scan_finish(s);
	if (s->hw->connection == SANE_MAGICOLOR_NET) {
		sanei_magicolor_net_close(s);
		sanei_tcp_close(s->fd);
	} else if (s->hw->connection == SANE_MAGICOLOR_USB) {
		sanei_usb_close(s->fd);
	}

	s->fd = -1;
}

static SANE_Bool
split_scanner_name (const char *name, char * IP, unsigned int *model)
{
	const char *device = name;
	const char *qm;
	*model = 0;
	/* cut off leading net: */
	if (strncmp(device, "net:", 4) == 0)
		device = &device[4];

	qm = strchr(device, '?');
	if (qm != NULL) {
		size_t len = qm-device;
		strncpy (IP, device, len);
		IP[len] = '\0';
		qm++;
		if (strncmp(qm, "model=", 6) == 0) {
			qm += 6;
			if (!sscanf(qm, "0x%x", model))
				sscanf(qm, "%x", model);
		}
	} else {
		strcpy (IP, device);
	}
	return SANE_TRUE;
}

/*
 * open_scanner()
 *
 * Open the scanner device. Depending on the connection method,
 * different open functions are called.
 */

static SANE_Status
open_scanner(Magicolor_Scanner *s)
{
	SANE_Status status = 0;

	DBG(7, "%s: %s\n", __func__, s->hw->sane.name);

	if (s->fd != -1) {
		DBG(7, "scanner is already open: fd = %d\n", s->fd);
		return SANE_STATUS_GOOD;	/* no need to open the scanner */
	}

	if (s->hw->connection == SANE_MAGICOLOR_NET) {
		/* device name has the form net:ipaddr?model=... */
		char IP[1024];
		unsigned int model = 0;
		if (!split_scanner_name (s->hw->sane.name, IP, &model))
			return SANE_STATUS_INVAL;
		status = sanei_tcp_open(IP, 4567, &s->fd);
		if (model>0)
			mc_set_device (s, model);
		if (status == SANE_STATUS_GOOD) {
			DBG(7, "awaiting welcome message\n");
			status = sanei_magicolor_net_open (s);
		}

	} else if (s->hw->connection == SANE_MAGICOLOR_USB) {
		status = sanei_usb_open(s->hw->sane.name, &s->fd);
		if (s->hw->cap->out_ep>0)
			sanei_usb_set_endpoint (s->fd,
				USB_DIR_OUT | USB_ENDPOINT_TYPE_BULK, s->hw->cap->out_ep);
		if (s->hw->cap->in_ep>0)
			sanei_usb_set_endpoint (s->fd,
				USB_DIR_IN | USB_ENDPOINT_TYPE_BULK, s->hw->cap->in_ep);
	}

	if (status == SANE_STATUS_ACCESS_DENIED) {
		DBG(1, "please check that you have permissions on the device.\n");
		DBG(1, "if this is a multi-function device with a printer,\n");
		DBG(1, "disable any conflicting driver (like usblp).\n");
	}

	if (status != SANE_STATUS_GOOD)
		DBG(1, "%s open failed: %s\n", s->hw->sane.name,
			sane_strstatus(status));
	else
		DBG(3, "scanner opened\n");

	return status;
}

static SANE_Status
detect_usb(struct Magicolor_Scanner *s)
{
	SANE_Status status;
	int vendor, product;
	int i, numIds;
	SANE_Bool is_valid;

	/* if the sanei_usb_get_vendor_product call is not supported,
	 * then we just ignore this and rely on the user to config
	 * the correct device.
	 */

	status = sanei_usb_get_vendor_product(s->fd, &vendor, &product);
	if (status != SANE_STATUS_GOOD) {
		DBG(1, "the device cannot be verified - will continue\n");
		return SANE_STATUS_GOOD;
	}

	/* check the vendor ID to see if we are dealing with an MAGICOLOR device */
	if (vendor != SANE_MAGICOLOR_VENDOR_ID) {
		/* this is not a supported vendor ID */
		DBG(1, "not an Magicolor device at %s (vendor id=0x%x)\n",
		    s->hw->sane.name, vendor);
		return SANE_STATUS_INVAL;
	}

	numIds = sanei_magicolor_getNumberOfUSBProductIds();
	is_valid = SANE_FALSE;
	i = 0;

	/* check all known product IDs to verify that we know
	 *	   about the device */
	while (i != numIds && !is_valid) {
		if (product == sanei_magicolor_usb_product_ids[i])
			is_valid = SANE_TRUE;
		i++;
	}

	if (is_valid == SANE_FALSE) {
		DBG(1, "the device at %s is not a supported (product id=0x%x)\n",
		    s->hw->sane.name, product);
		return SANE_STATUS_INVAL;
	}

	DBG(2, "found valid Magicolor scanner: 0x%x/0x%x (vendorID/productID)\n",
	    vendor, product);
	mc_set_device(s, product);

	return SANE_STATUS_GOOD;
}

/*
 * used by attach* and sane_get_devices
 * a ptr to a single-linked list of Magicolor_Device structs
 * a ptr to a null term array of ptrs to SANE_Device structs
 */
static int num_devices;		/* number of scanners attached to backend */
static Magicolor_Device *first_dev;	/* first MAGICOLOR scanner in list */
static const SANE_Device **devlist = NULL;

static struct Magicolor_Scanner *
scanner_create(struct Magicolor_Device *dev, SANE_Status *status)
{
	struct Magicolor_Scanner *s;

	s = malloc(sizeof(struct Magicolor_Scanner));
	if (s == NULL) {
		*status = SANE_STATUS_NO_MEM;
		return NULL;
	}

	memset(s, 0x00, sizeof(struct Magicolor_Scanner));

	s->fd = -1;
	s->hw = dev;

	return s;
}

static struct Magicolor_Scanner *
device_detect(const char *name, int type, SANE_Status *status)
{
	struct Magicolor_Scanner *s;
	struct Magicolor_Device *dev;

	/* try to find the device in our list */
	for (dev = first_dev; dev; dev = dev->next) {
		if (strcmp(dev->sane.name, name) == 0) {
			dev->missing = 0;
			DBG (10, "%s: Device %s already attached!\n", __func__,
			     name);
			return scanner_create(dev, status);
		}
	}

	if (type == SANE_MAGICOLOR_NODEV) {
		*status = SANE_STATUS_INVAL;
		return NULL;
	}

	/* alloc and clear our device structure */
	dev = malloc(sizeof(*dev));
	if (!dev) {
		*status = SANE_STATUS_NO_MEM;
		return NULL;
	}
	memset(dev, 0x00, sizeof(struct Magicolor_Device));

	s = scanner_create(dev, status);
	if (s == NULL)
		return NULL;

	mc_dev_init(dev, name, type);

	*status = open_scanner(s);
	if (*status != SANE_STATUS_GOOD) {
		free(s);
		return NULL;
	}

	/* from now on, close_scanner() must be called */

	/* USB requires special care */
	if (dev->connection == SANE_MAGICOLOR_USB) {
		*status = detect_usb(s);
	}

	if (*status != SANE_STATUS_GOOD)
		goto close;

	/* set name and model (if not already set) */
	if (dev->model == NULL)
		mc_set_model(s, "generic", 7);

	dev->name = strdup(name);
	dev->sane.name = dev->name;

	*status = mc_discover_capabilities(s);
	if (*status != SANE_STATUS_GOOD)
		goto close;

	if (source_list[0] == NULL || dev->cap->dpi_range.min == 0) {
		DBG(1, "something is wrong in the discovery process, aborting.\n");
		*status = SANE_STATUS_IO_ERROR;
		goto close;
	}

	mc_dev_post_init(dev);

	/* add this scanner to the device list */
	num_devices++;
	dev->missing = 0;
	dev->next = first_dev;
	first_dev = dev;

	return s;

	close:
	close_scanner(s);
	free(s);
	return NULL;
}

#if HAVE_LIBSNMP

/* Keep a linked list of already observed IP addresses */
/* typedef struct snmp_ip SNMP_IP; */
typedef struct snmp_ip {
  char ip_addr[1024];
  struct snmp_ip*next;
} snmp_ip;

typedef struct {
  int nr;
  snmp_ip*handled;
  snmp_ip*detected;
} snmp_discovery_data;


/** Handle one SNMP response (whether received sync or async) and if describes
 * a magicolor device, attach it. Returns the number of attached devices (0
 * or 1) */
static int
mc_network_discovery_handle (struct snmp_pdu *pdu, snmp_discovery_data *magic)
{
	netsnmp_variable_list *varlist = pdu->variables, *vp;
	oid anOID[MAX_OID_LEN];
	size_t anOID_len = MAX_OID_LEN;
	/* Device information variables */
	char ip_addr[1024] = "";
	char model[1024] = "";
	char device[1024] = "";
	/* remote IP detection variables */
	netsnmp_indexed_addr_pair *responder = (netsnmp_indexed_addr_pair *) pdu->transport_data;
	struct sockaddr_in *remote = NULL;
	struct MagicolorCap *cap;
	snmp_ip *ip = NULL;

	DBG(5, "%s: Handling SNMP response \n", __func__);

	if (responder == NULL || pdu->transport_data_length != sizeof(netsnmp_indexed_addr_pair )) {
		DBG(1, "%s: Unable to extract IP address from SNMP response.\n",
		    __func__);
		return 0;
	}
	remote = (struct sockaddr_in *) &(responder->remote_addr);
	if (remote == NULL) {
		DBG(1, "%s: Unable to extract IP address from SNMP response.\n",
			__func__);
		return 0;
	}
	snprintf(ip_addr, sizeof(ip_addr), "%s", inet_ntoa(remote->sin_addr));
	DBG(35, "%s: IP Address of responder is %s\n", __func__, ip_addr);
	if (magic)
		ip = magic->handled;
	while (ip) {
		if (strcmp (ip->ip_addr, ip_addr) == 0) {
			DBG (5, "%s: Already handled device %s, skipping\n", __func__, ip_addr);
			return 0;
		}
		ip = ip->next;
	}
	if (magic) {
		snmp_ip *new_handled = malloc(sizeof(snmp_ip));
		strcpy (&new_handled->ip_addr[0], ip_addr);
		new_handled->next = magic->handled;
		magic->handled = new_handled;
	}

	/* System Object ID (Unique OID identifying model)
	 * This determines whether we really have a magicolor device */
	anOID_len = MAX_OID_LEN;
	read_objid(MAGICOLOR_SNMP_SYSOBJECT_OID, anOID, &anOID_len);
	vp = find_varbind_in_list (varlist, anOID, anOID_len);
	if (vp) {
		size_t value_len = vp->val_len/sizeof(oid);
		if (vp->type != ASN_OBJECT_ID) {
			DBG (3, "%s: SystemObjectID does not return an OID, device is not a magicolor device\n", __func__);
			return 0;
		}

		// Make sure that snprint_objid gives us just numbers, instead of a
		// SNMPv2-SMI::enterprises prefix.
		netsnmp_ds_set_int(NETSNMP_DS_LIBRARY_ID,
				   NETSNMP_DS_LIB_OID_OUTPUT_FORMAT,
				   NETSNMP_OID_OUTPUT_NUMERIC);

		snprint_objid (device, sizeof(device), vp->val.objid, value_len);
		DBG (5, "%s: Device object ID is '%s'\n", __func__, device);

		anOID_len = MAX_OID_LEN;
		read_objid (MAGICOLOR_SNMP_DEVICE_TREE, anOID, &anOID_len);
		if (netsnmp_oid_is_subtree (anOID, anOID_len,
				vp->val.objid, value_len) == 0) {
			DBG (5, "%s: Device appears to be a magicolor device (OID=%s)\n", __func__, device);
		} else {
			DBG (5, "%s: Device is not a Magicolor device\n", __func__);
			return 0;
		}
	}

	/* Retrieve sysDescr (i.e. model name) */
	anOID_len = MAX_OID_LEN;
	read_objid(MAGICOLOR_SNMP_SYSDESCR_OID, anOID, &anOID_len);
	vp = find_varbind_in_list (varlist, anOID, anOID_len);
	if (vp) {
		size_t model_len = min(vp->val_len, sizeof(model) - 1);
		memcpy(model, vp->val.string, model_len);
		model[model_len] = '\0';
		DBG (5, "%s: Found model: %s\n", __func__, model);
	}

	DBG (1, "%s: Detected device '%s' on IP %s\n",
	     __func__, model, ip_addr);

	vp = pdu->variables;
	/* TODO: attach the IP with attach_one_net(ip) */
	cap = mc_get_device_from_identification (device);
	if (cap) {
		DBG(1, "%s: Found autodiscovered device: %s (type 0x%x)\n", __func__, cap->model, cap->id);
		attach_one_net (ip_addr, cap->id);
		if (magic) {
			snmp_ip *new_detected = malloc(sizeof(snmp_ip));
			strcpy (&new_detected->ip_addr[0], ip_addr);
			new_detected->next = magic->detected;
			magic->detected = new_detected;
		}
		return 1;
	}
	return 0;
}

static int
mc_network_discovery_cb (int operation, struct snmp_session *sp, int reqid,
			 struct snmp_pdu *pdu, void *magic)
{
	NOT_USED (reqid);
	NOT_USED (sp);
	DBG(5, "%s: Received broadcast response \n", __func__);

	if (operation == NETSNMP_CALLBACK_OP_RECEIVED_MESSAGE) {
		snmp_discovery_data *m = (snmp_discovery_data*)magic;
		int nr = mc_network_discovery_handle (pdu, m);
		m->nr += nr;
		DBG(5, "%s: Added %d discovered host(s) for SNMP response.\n", __func__, nr);
	}

	return 0;
}
#endif

/* Use SNMP for automatic network discovery. If host is given, try to detect
 * that one host (using sync SNMP, otherwise send an SNMP broadcast (async).
 */
static int
mc_network_discovery(const char*host)
{
#if HAVE_LIBSNMP
	netsnmp_session session, *ss;
	netsnmp_pdu *pdu;
	oid anOID[MAX_OID_LEN];
	size_t anOID_len = MAX_OID_LEN;
	snmp_discovery_data magic;
	magic.nr = 0;
	magic.handled = 0;
	magic.detected = 0;

	DBG(1, "%s: running network discovery \n", __func__);

	/* Win32: init winsock */
	SOCK_STARTUP;
	init_snmp("sane-magicolor-backend");
	snmp_sess_init (&session);
	session.version = SNMP_VERSION_2c;
	session.community = (u_char *) "public";
	session.community_len = strlen ((char *)session.community);
	if (host) {
		session.peername = (char *) host;
	} else {
		/* Do a network discovery via a broadcast */
		session.peername = "255.255.255.255";
		session.flags   |= SNMP_FLAGS_UDP_BROADCAST;
		session.callback = mc_network_discovery_cb;
		session.callback_magic = &magic;
	}

	ss = snmp_open (&session); /* establish the session */
	if (!ss) {
		snmp_sess_perror ("ack", &session);
		SOCK_CLEANUP;
		return 0;
	}

	/* Create the PDU for the data for our request and add the three
	 * desired OIDs to the PDU */
	pdu = snmp_pdu_create (SNMP_MSG_GET);

	/* SNMPv2-MIB::sysDescr.0 */
	anOID_len = MAX_OID_LEN;
	if (read_objid(MAGICOLOR_SNMP_SYSDESCR_OID, anOID, &anOID_len)) {
		snmp_add_null_var (pdu, anOID, anOID_len);
	}
	/* SNMPv2-MIB::sysObjectID.0 */
	anOID_len = MAX_OID_LEN;
	if (read_objid(MAGICOLOR_SNMP_SYSOBJECT_OID, anOID, &anOID_len)) {
		snmp_add_null_var (pdu, anOID, anOID_len);
	}
	/* IF-MIB::ifPhysAddress.1 */
	anOID_len = MAX_OID_LEN;
	if (read_objid(MAGICOLOR_SNMP_MAC_OID, anOID, &anOID_len)) {
		snmp_add_null_var (pdu, anOID, anOID_len);
	}
	/* TODO: Add more interesting OIDs, in particular vendor OIDs */

	/* Now send out the request and wait for responses for some time.
	 * If we get a response, connect to that device (in the callback),
	 * otherwise we probably don't have a magicolor device in the
	 * LAN (or SNMP is turned off, in which case we have no way to detect
	 * it.
	 */
	DBG(100, "%s: Sending SNMP packet\n", __func__);
	if (host) {
		/* sync request to given hostname, immediately read the reply */
		netsnmp_pdu *response = 0;
		int status = snmp_synch_response(ss, pdu, &response);
 		if (status == STAT_SUCCESS && response->errstat == SNMP_ERR_NOERROR) {
			magic.nr = mc_network_discovery_handle (response, &magic);
		}
		if (response)
			snmp_free_pdu(response);


	} else {
		/* No hostname, so do a broadcast */
		struct timeval nowtime, endtime; /* end time for SNMP scan */
		struct timeval timeout;
		int i=0;

		if (!snmp_send(ss, pdu)) {
			snmp_free_pdu(pdu);
			DBG(100, "%s: Sending SNMP packet NOT successful\n", __func__);
			return 0;
		}
		/* listen for responses for MC_AutoDetectionTimeout milliseconds: */
		/* First get the final timeout time */
		gettimeofday (&nowtime, NULL);
		timeout.tv_sec = MC_SNMP_Timeout / 1000;
		timeout.tv_usec = (MC_SNMP_Timeout % 1000) * 1000;
		timeradd (&nowtime, &timeout, &endtime);

		while (timercmp(&nowtime, &endtime, <)) {
			int fds = 0, block = 0;
			fd_set fdset;
			DBG(1, "    loop=%d\n", i++);
			timeout.tv_sec = 0;
			/* Use a 125ms timeout for select. If we get a response,
			 * the loop will be entered earlier again, anyway */
			timeout.tv_usec = 125000;
			FD_ZERO (&fdset);
			snmp_select_info (&fds, &fdset, &timeout, &block);
			fds = select (fds, &fdset, NULL, NULL, /*block?NULL:*/&timeout);
			if (fds) snmp_read(&fdset);
			else snmp_timeout();
			gettimeofday(&nowtime, NULL);
		}
		/* Clean up the data in magic */
		while (magic.handled) {
		  snmp_ip *tmp = magic.handled->next;
		  free (magic.handled);
		  magic.handled = tmp;
		}
		while (magic.detected) {
		  snmp_ip *tmp = magic.detected->next;
		  free (magic.detected);
		  magic.detected = tmp;
		}
	}

	/* Clean up */
	snmp_close(ss);
	SOCK_CLEANUP;
	DBG (5, "%s: Discovered %d host(s)\n", __func__, magic.nr);
	return magic.nr;

#else
	DBG (1, "%s: net-snmp library not enabled, auto-detecting network scanners not supported.\n", __func__);
	NOT_USED (host);
	return 0;
#endif
}

static SANE_Status
attach(const char *name, int type)
{
	SANE_Status status;
	Magicolor_Scanner *s;

	DBG(7, "%s: devname = %s, type = %d\n", __func__, name, type);

	s = device_detect(name, type, &status);
	if(s == NULL)
		return status;

	close_scanner(s);
	free(s);
	return status;
}

SANE_Status
attach_one_usb(const char *dev)
{
	DBG(7, "%s: dev = %s\n", __func__, dev);
	return attach(dev, SANE_MAGICOLOR_USB);
}

static SANE_Status
attach_one_net(const char *dev, unsigned int model)
{
	char name[1024];

	DBG(7, "%s: dev = %s\n", __func__, dev);
	if (model > 0) {
		snprintf(name, 1024, "net:%s?model=0x%x", dev, model);
	} else {
		snprintf(name, 1024, "net:%s", dev);
	}

	return attach(name, SANE_MAGICOLOR_NET);
}

static SANE_Status
attach_one_config(SANEI_Config __sane_unused__ *config, const char *line,
		  void *data)
{
	int vendor, product, timeout;
	SANE_Bool local_only = *(SANE_Bool*) data;
	int len = strlen(line);

	DBG(7, "%s: len = %d, line = %s\n", __func__, len, line);

	if (sscanf(line, "usb %i %i", &vendor, &product) == 2) {
		/* add the vendor and product IDs to the list of
		 *		   known devices before we call the attach function */

		int numIds = sanei_magicolor_getNumberOfUSBProductIds();

		if (vendor != SANE_MAGICOLOR_VENDOR_ID)
			return SANE_STATUS_INVAL; /* this is not a KONICA MINOLTA device */

		sanei_magicolor_usb_product_ids[numIds - 1] = product;
		sanei_usb_attach_matching_devices(line, attach_one_usb);

	} else if (strncmp(line, "usb", 3) == 0 && len == 3) {
		int i, numIds;

		numIds = sanei_magicolor_getNumberOfUSBProductIds();

		for (i = 0; i < numIds; i++) {
			sanei_usb_find_devices(SANE_MAGICOLOR_VENDOR_ID,
					       sanei_magicolor_usb_product_ids[i], attach_one_usb);
		}

	} else if (strncmp(line, "net", 3) == 0) {

		if (!local_only) {
			/* remove the "net" sub string */
			const char *name =
				sanei_config_skip_whitespace(line + 3);
			char IP[1024];
			unsigned int model = 0;

			if (strncmp(name, "autodiscovery", 13) == 0) {
				DBG (50, "%s: Initiating network autodiscovervy via SNMP\n", __func__);
				mc_network_discovery(NULL);
			} else if (sscanf(name, "%s %x", IP, &model) == 2) {
				DBG(50, "%s: Using network device on IP %s, forcing model 0x%x\n", __func__, IP, model);
				attach_one_net(IP, model);
			} else {
				/* use SNMP to detect the type. If not successful,
				 * add the host with model type 0 */
				DBG(50, "%s: Using network device on IP %s, trying to autodetect model\n", __func__, IP);
				if (mc_network_discovery(name)==0) {
					DBG(1, "%s: Autodetecting device model failed, using default model\n", __func__);
					attach_one_net(name, 0);
				}
			}
		}

	} else if (sscanf(line, "snmp-timeout %i\n", &timeout)) {
		/* Timeout for SNMP network discovery */
		DBG(50, "%s: SNMP timeout set to %d\n", __func__, timeout);
		MC_SNMP_Timeout = timeout;

	} else if (sscanf(line, "scan-data-timeout %i\n", &timeout)) {
		/* Timeout for scan data requests */
		DBG(50, "%s: Scan data timeout set to %d\n", __func__, timeout);
		MC_Scan_Data_Timeout = timeout;

	} else if (sscanf(line, "request-timeout %i\n", &timeout)) {
		/* Timeout for all other read requests */
		DBG(50, "%s: Request timeout set to %d\n", __func__, timeout);
		MC_Request_Timeout = timeout;

	} else {
		/* TODO: Warning about unparsable line! */
	}

	return SANE_STATUS_GOOD;
}

static void
free_devices(void)
{
	Magicolor_Device *dev, *next;

	DBG(5, "%s\n", __func__);

	for (dev = first_dev; dev; dev = next) {
		next = dev->next;
		free(dev->name);
		free(dev->model);
		free(dev);
	}

	if (devlist)
		free(devlist);
	devlist = NULL;
	first_dev = NULL;
}

SANE_Status
sane_init(SANE_Int *version_code, SANE_Auth_Callback __sane_unused__ authorize)
{
	DBG_INIT();
	DBG(2, "%s: " PACKAGE " " VERSION "\n", __func__);

	DBG(1, "magicolor backend, version %i.%i.%i\n",
	    MAGICOLOR_VERSION, MAGICOLOR_REVISION, MAGICOLOR_BUILD);

	if (version_code != NULL)
		*version_code = SANE_VERSION_CODE(SANE_CURRENT_MAJOR, SANE_CURRENT_MINOR,
						  MAGICOLOR_BUILD);

	sanei_usb_init();

	return SANE_STATUS_GOOD;
}

/* Clean up the list of attached scanners. */
void
sane_exit(void)
{
	DBG(5, "%s\n", __func__);
	free_devices();
}

SANE_Status
sane_get_devices(const SANE_Device ***device_list, SANE_Bool local_only)
{
	Magicolor_Device *dev, *s, *prev=0;
	int i;

	DBG(5, "%s\n", __func__);

	sanei_usb_init();

	/* mark all existing scanners as missing, attach_one will remove mark */
	for (s = first_dev; s; s = s->next) {
		s->missing = 1;
	}

	/* Read the config, mark each device as found, possibly add new devs */
	sanei_configure_attach(MAGICOLOR_CONFIG_FILE, NULL,
			       attach_one_config, &local_only);

	/*delete missing scanners from list*/
	for (s = first_dev; s;) {
		if (s->missing) {
			DBG (5, "%s: missing scanner %s\n", __func__, s->name);

			/*splice s out of list by changing pointer in prev to next*/
			if (prev) {
				prev->next = s->next;
				free (s);
				s = prev->next;
				num_devices--;
			} else {
				/*remove s from head of list */
				first_dev = s->next;
				free(s);
				s = first_dev;
				prev=NULL;
				num_devices--;
			}
		} else {
			prev = s;
			s = prev->next;
		}
	}

	DBG (15, "%s: found %d scanner(s)\n", __func__, num_devices);
	for (s = first_dev; s; s=s->next) {
		DBG (15, "%s: found scanner %s\n", __func__, s->name);
	}

	if (devlist)
		free (devlist);

	devlist = malloc((num_devices + 1) * sizeof(devlist[0]));
	if (!devlist) {
		DBG(1, "out of memory (line %d)\n", __LINE__);
		return SANE_STATUS_NO_MEM;
	}

	DBG(5, "%s - results:\n", __func__);

	for (i = 0, dev = first_dev; i < num_devices && dev; dev = dev->next, i++) {
		DBG(1, " %d (%d): %s\n", i, dev->connection, dev->model);
		devlist[i] = &dev->sane;
	}

	devlist[i] = NULL;

	if(device_list){
		*device_list = devlist;
	}

	return SANE_STATUS_GOOD;
}

static SANE_Status
init_options(Magicolor_Scanner *s)
{
	int i;
	SANE_Word *res_list;

	for (i = 0; i < NUM_OPTIONS; i++) {
		s->opt[i].size = sizeof(SANE_Word);
		s->opt[i].cap = SANE_CAP_SOFT_SELECT | SANE_CAP_SOFT_DETECT;
	}

	s->opt[OPT_NUM_OPTS].title = SANE_TITLE_NUM_OPTIONS;
	s->opt[OPT_NUM_OPTS].desc = SANE_DESC_NUM_OPTIONS;
	s->opt[OPT_NUM_OPTS].type = SANE_TYPE_INT;
	s->opt[OPT_NUM_OPTS].cap = SANE_CAP_SOFT_DETECT;
	s->val[OPT_NUM_OPTS].w = NUM_OPTIONS;

	/* "Scan Mode" group: */

	s->opt[OPT_MODE_GROUP].name = SANE_NAME_STANDARD;
	s->opt[OPT_MODE_GROUP].title = SANE_TITLE_STANDARD;
	s->opt[OPT_MODE_GROUP].desc = SANE_DESC_STANDARD;
	s->opt[OPT_MODE_GROUP].type = SANE_TYPE_GROUP;
	s->opt[OPT_MODE_GROUP].cap = 0;

	/* scan mode */
	s->opt[OPT_MODE].name = SANE_NAME_SCAN_MODE;
	s->opt[OPT_MODE].title = SANE_TITLE_SCAN_MODE;
	s->opt[OPT_MODE].desc = SANE_DESC_SCAN_MODE;
	s->opt[OPT_MODE].type = SANE_TYPE_STRING;
	s->opt[OPT_MODE].size = max_string_size(mode_list);
	s->opt[OPT_MODE].constraint_type = SANE_CONSTRAINT_STRING_LIST;
	s->opt[OPT_MODE].constraint.string_list = mode_list;
	s->val[OPT_MODE].w = 0;	/* Binary */

	/* bit depth */
	s->opt[OPT_BIT_DEPTH].name = SANE_NAME_BIT_DEPTH;
	s->opt[OPT_BIT_DEPTH].title = SANE_TITLE_BIT_DEPTH;
	s->opt[OPT_BIT_DEPTH].desc = SANE_DESC_BIT_DEPTH;
	s->opt[OPT_BIT_DEPTH].type = SANE_TYPE_INT;
	s->opt[OPT_BIT_DEPTH].unit = SANE_UNIT_NONE;
	s->opt[OPT_BIT_DEPTH].constraint_type = SANE_CONSTRAINT_WORD_LIST;
	s->opt[OPT_BIT_DEPTH].constraint.word_list = s->hw->cap->depth_list;
	s->opt[OPT_BIT_DEPTH].cap |= SANE_CAP_INACTIVE;
	s->val[OPT_BIT_DEPTH].w = s->hw->cap->depth_list[1];	/* the first "real" element is the default */

	if (s->hw->cap->depth_list[0] == 1)	/* only one element in the list -> hide the option */
		s->opt[OPT_BIT_DEPTH].cap |= SANE_CAP_INACTIVE;


	/* brightness */
	s->opt[OPT_BRIGHTNESS].name = SANE_NAME_BRIGHTNESS;
	s->opt[OPT_BRIGHTNESS].title = SANE_TITLE_BRIGHTNESS;
	s->opt[OPT_BRIGHTNESS].desc = SANE_DESC_BRIGHTNESS;
	s->opt[OPT_BRIGHTNESS].type = SANE_TYPE_INT;
	s->opt[OPT_BRIGHTNESS].unit = SANE_UNIT_NONE;
	s->opt[OPT_BRIGHTNESS].constraint_type = SANE_CONSTRAINT_RANGE;
	s->opt[OPT_BRIGHTNESS].constraint.range = &s->hw->cap->brightness;
	s->val[OPT_BRIGHTNESS].w = 5;	/* Normal */

	/* resolution */
	s->opt[OPT_RESOLUTION].name = SANE_NAME_SCAN_RESOLUTION;
	s->opt[OPT_RESOLUTION].title = SANE_TITLE_SCAN_RESOLUTION;
	s->opt[OPT_RESOLUTION].desc = SANE_DESC_SCAN_RESOLUTION;
	s->opt[OPT_RESOLUTION].type = SANE_TYPE_INT;
	s->opt[OPT_RESOLUTION].unit = SANE_UNIT_DPI;
	s->opt[OPT_RESOLUTION].constraint_type = SANE_CONSTRAINT_WORD_LIST;
	res_list = malloc((s->hw->cap->res_list_size + 1) * sizeof(SANE_Word));
	if (res_list == NULL) {
		return SANE_STATUS_NO_MEM;
	}
	*(res_list) = s->hw->cap->res_list_size;
	memcpy(&(res_list[1]), s->hw->cap->res_list, s->hw->cap->res_list_size * sizeof(SANE_Word));
	s->opt[OPT_RESOLUTION].constraint.word_list = res_list;
	s->val[OPT_RESOLUTION].w = s->hw->cap->dpi_range.min;


	/* preview */
	s->opt[OPT_PREVIEW].name = SANE_NAME_PREVIEW;
	s->opt[OPT_PREVIEW].title = SANE_TITLE_PREVIEW;
	s->opt[OPT_PREVIEW].desc = SANE_DESC_PREVIEW;
	s->opt[OPT_PREVIEW].type = SANE_TYPE_BOOL;
	s->val[OPT_PREVIEW].w = SANE_FALSE;

	/* source */
	s->opt[OPT_SOURCE].name = SANE_NAME_SCAN_SOURCE;
	s->opt[OPT_SOURCE].title = SANE_TITLE_SCAN_SOURCE;
	s->opt[OPT_SOURCE].desc = SANE_DESC_SCAN_SOURCE;
	s->opt[OPT_SOURCE].type = SANE_TYPE_STRING;
	s->opt[OPT_SOURCE].size = max_string_size(source_list);
	s->opt[OPT_SOURCE].constraint_type = SANE_CONSTRAINT_STRING_LIST;
	s->opt[OPT_SOURCE].constraint.string_list = source_list;
	s->val[OPT_SOURCE].w = 0;	/* always use Flatbed as default */

	s->opt[OPT_ADF_MODE].name = "adf-mode";
	s->opt[OPT_ADF_MODE].title = SANE_I18N("ADF Mode");
	s->opt[OPT_ADF_MODE].desc =
	SANE_I18N("Selects the ADF mode (simplex/duplex)");
	s->opt[OPT_ADF_MODE].type = SANE_TYPE_STRING;
	s->opt[OPT_ADF_MODE].size = max_string_size(adf_mode_list);
	s->opt[OPT_ADF_MODE].constraint_type = SANE_CONSTRAINT_STRING_LIST;
	s->opt[OPT_ADF_MODE].constraint.string_list = adf_mode_list;
	s->val[OPT_ADF_MODE].w = 0;	/* simplex */
	if ((!s->hw->cap->ADF) || (s->hw->cap->adf_duplex == SANE_FALSE))
		s->opt[OPT_ADF_MODE].cap |= SANE_CAP_INACTIVE;


	/* "Geometry" group: */
	s->opt[OPT_GEOMETRY_GROUP].name = SANE_NAME_GEOMETRY;
	s->opt[OPT_GEOMETRY_GROUP].title = SANE_TITLE_GEOMETRY;
	s->opt[OPT_GEOMETRY_GROUP].desc = SANE_DESC_GEOMETRY;
	s->opt[OPT_GEOMETRY_GROUP].type = SANE_TYPE_GROUP;
	s->opt[OPT_GEOMETRY_GROUP].cap = SANE_CAP_ADVANCED;

	/* top-left x */
	s->opt[OPT_TL_X].name = SANE_NAME_SCAN_TL_X;
	s->opt[OPT_TL_X].title = SANE_TITLE_SCAN_TL_X;
	s->opt[OPT_TL_X].desc = SANE_DESC_SCAN_TL_X;
	s->opt[OPT_TL_X].type = SANE_TYPE_FIXED;
	s->opt[OPT_TL_X].unit = SANE_UNIT_MM;
	s->opt[OPT_TL_X].constraint_type = SANE_CONSTRAINT_RANGE;
	s->opt[OPT_TL_X].constraint.range = s->hw->x_range;
	s->val[OPT_TL_X].w = 0;

	/* top-left y */
	s->opt[OPT_TL_Y].name = SANE_NAME_SCAN_TL_Y;
	s->opt[OPT_TL_Y].title = SANE_TITLE_SCAN_TL_Y;
	s->opt[OPT_TL_Y].desc = SANE_DESC_SCAN_TL_Y;
	s->opt[OPT_TL_Y].type = SANE_TYPE_FIXED;
	s->opt[OPT_TL_Y].unit = SANE_UNIT_MM;
	s->opt[OPT_TL_Y].constraint_type = SANE_CONSTRAINT_RANGE;
	s->opt[OPT_TL_Y].constraint.range = s->hw->y_range;
	s->val[OPT_TL_Y].w = 0;

	/* bottom-right x */
	s->opt[OPT_BR_X].name = SANE_NAME_SCAN_BR_X;
	s->opt[OPT_BR_X].title = SANE_TITLE_SCAN_BR_X;
	s->opt[OPT_BR_X].desc = SANE_DESC_SCAN_BR_X;
	s->opt[OPT_BR_X].type = SANE_TYPE_FIXED;
	s->opt[OPT_BR_X].unit = SANE_UNIT_MM;
	s->opt[OPT_BR_X].constraint_type = SANE_CONSTRAINT_RANGE;
	s->opt[OPT_BR_X].constraint.range = s->hw->x_range;
	s->val[OPT_BR_X].w = s->hw->x_range->max;

	/* bottom-right y */
	s->opt[OPT_BR_Y].name = SANE_NAME_SCAN_BR_Y;
	s->opt[OPT_BR_Y].title = SANE_TITLE_SCAN_BR_Y;
	s->opt[OPT_BR_Y].desc = SANE_DESC_SCAN_BR_Y;
	s->opt[OPT_BR_Y].type = SANE_TYPE_FIXED;
	s->opt[OPT_BR_Y].unit = SANE_UNIT_MM;
	s->opt[OPT_BR_Y].constraint_type = SANE_CONSTRAINT_RANGE;
	s->opt[OPT_BR_Y].constraint.range = s->hw->y_range;
	s->val[OPT_BR_Y].w = s->hw->y_range->max;

	return SANE_STATUS_GOOD;
}

SANE_Status
sane_open(SANE_String_Const name, SANE_Handle *handle)
{
	SANE_Status status;
	Magicolor_Scanner *s = NULL;

	int l = strlen(name);

	DBG(7, "%s: name = %s\n", __func__, name);

	/* probe if empty device name provided */
	if (l == 0) {

		status = sane_get_devices(NULL,0);
		if (status != SANE_STATUS_GOOD) {
			return status;
		}

		if (first_dev == NULL) {
			DBG(1, "no device detected\n");
			return SANE_STATUS_INVAL;
		}

		s = device_detect(first_dev->sane.name, first_dev->connection,
					&status);
		if (s == NULL) {
			DBG(1, "cannot open a perfectly valid device (%s),"
				" please report to the authors\n", name);
			return SANE_STATUS_INVAL;
		}

	} else {

		if (strncmp(name, "net:", 4) == 0) {
			s = device_detect(name, SANE_MAGICOLOR_NET, &status);
			if (s == NULL)
				return status;
		} else if (strncmp(name, "libusb:", 7) == 0) {
			s = device_detect(name, SANE_MAGICOLOR_USB, &status);
			if (s == NULL)
				return status;
		} else {

			/* as a last resort, check for a match
			 * in the device list. This should handle platforms without libusb.
			 */
			if (first_dev == NULL) {
				status = sane_get_devices(NULL,0);
				if (status != SANE_STATUS_GOOD) {
					return status;
				}
			}

			s = device_detect(name, SANE_MAGICOLOR_NODEV, &status);
			if (s == NULL) {
				DBG(1, "invalid device name: %s\n", name);
				return SANE_STATUS_INVAL;
			}
		}
	}


	/* s is always valid here */

	DBG(1, "handle obtained\n");

	init_options(s);

	*handle = (SANE_Handle) s;

	status = open_scanner(s);
	if (status != SANE_STATUS_GOOD) {
		free(s);
		return status;
	}

	return status;
}

void
sane_close(SANE_Handle handle)
{
	Magicolor_Scanner *s;

	/*
	 * XXX Test if there is still data pending from
	 * the scanner. If so, then do a cancel
	 */

	s = (Magicolor_Scanner *) handle;

	if (s->fd != -1)
		close_scanner(s);

	free(s);
}

const SANE_Option_Descriptor *
sane_get_option_descriptor(SANE_Handle handle, SANE_Int option)
{
	Magicolor_Scanner *s = (Magicolor_Scanner *) handle;

	if (option < 0 || option >= NUM_OPTIONS)
		return NULL;

	return s->opt + option;
}

static const SANE_String_Const *
search_string_list(const SANE_String_Const *list, SANE_String value)
{
	while (*list != NULL && strcmp(value, *list) != 0)
		list++;

	return ((*list == NULL) ? NULL : list);
}

/*
    Activate, deactivate an option. Subroutines so we can add
    debugging info if we want. The change flag is set to TRUE
    if we changed an option. If we did not change an option,
    then the value of the changed flag is not modified.
*/

static void
activateOption(Magicolor_Scanner *s, SANE_Int option, SANE_Bool *change)
{
	if (!SANE_OPTION_IS_ACTIVE(s->opt[option].cap)) {
		s->opt[option].cap &= ~SANE_CAP_INACTIVE;
		*change = SANE_TRUE;
	}
}

static void
deactivateOption(Magicolor_Scanner *s, SANE_Int option, SANE_Bool *change)
{
	if (SANE_OPTION_IS_ACTIVE(s->opt[option].cap)) {
		s->opt[option].cap |= SANE_CAP_INACTIVE;
		*change = SANE_TRUE;
	}
}

static SANE_Status
getvalue(SANE_Handle handle, SANE_Int option, void *value)
{
	Magicolor_Scanner *s = (Magicolor_Scanner *) handle;
	SANE_Option_Descriptor *sopt = &(s->opt[option]);
	Option_Value *sval = &(s->val[option]);

	DBG(17, "%s: option = %d\n", __func__, option);

	switch (option) {

	case OPT_NUM_OPTS:
	case OPT_BIT_DEPTH:
	case OPT_BRIGHTNESS:
	case OPT_RESOLUTION:
	case OPT_PREVIEW:
	case OPT_TL_X:
	case OPT_TL_Y:
	case OPT_BR_X:
	case OPT_BR_Y:
		*((SANE_Word *) value) = sval->w;
		break;

	case OPT_MODE:
	case OPT_SOURCE:
	case OPT_ADF_MODE:
		strcpy((char *) value, sopt->constraint.string_list[sval->w]);
		break;

	default:
		return SANE_STATUS_INVAL;
	}

	return SANE_STATUS_GOOD;
}


/*
 * Handles setting the source (flatbed, or auto document feeder (ADF)).
 *
 */

static void
change_source(Magicolor_Scanner *s, SANE_Int optindex, char *value)
{
	int force_max = SANE_FALSE;
	SANE_Bool dummy;

	DBG(1, "%s: optindex = %d, source = '%s'\n", __func__, optindex,
	    value);

	if (s->val[OPT_SOURCE].w == optindex)
		return;

	s->val[OPT_SOURCE].w = optindex;

	if (s->val[OPT_TL_X].w == s->hw->x_range->min
	    && s->val[OPT_TL_Y].w == s->hw->y_range->min
	    && s->val[OPT_BR_X].w == s->hw->x_range->max
	    && s->val[OPT_BR_Y].w == s->hw->y_range->max) {
		force_max = SANE_TRUE;
	}

	if (strcmp(ADF_STR, value) == 0) {
		s->hw->x_range = &s->hw->cap->adf_x_range;
		s->hw->y_range = &s->hw->cap->adf_y_range;
		if (s->hw->cap->adf_duplex) {
			activateOption(s, OPT_ADF_MODE, &dummy);
		} else {
			deactivateOption(s, OPT_ADF_MODE, &dummy);
			s->val[OPT_ADF_MODE].w = 0;
		}

		DBG(1, "adf activated (%d)\n",s->hw->cap->adf_duplex);

	} else {
		/* ADF not active */
		s->hw->x_range = &s->hw->cap->fbf_x_range;
		s->hw->y_range = &s->hw->cap->fbf_y_range;

		deactivateOption(s, OPT_ADF_MODE, &dummy);
	}

	s->opt[OPT_BR_X].constraint.range = s->hw->x_range;
	s->opt[OPT_BR_Y].constraint.range = s->hw->y_range;

	if (s->val[OPT_TL_X].w < s->hw->x_range->min || force_max)
		s->val[OPT_TL_X].w = s->hw->x_range->min;

	if (s->val[OPT_TL_Y].w < s->hw->y_range->min || force_max)
		s->val[OPT_TL_Y].w = s->hw->y_range->min;

	if (s->val[OPT_BR_X].w > s->hw->x_range->max || force_max)
		s->val[OPT_BR_X].w = s->hw->x_range->max;

	if (s->val[OPT_BR_Y].w > s->hw->y_range->max || force_max)
		s->val[OPT_BR_Y].w = s->hw->y_range->max;

}

static SANE_Status
setvalue(SANE_Handle handle, SANE_Int option, void *value, SANE_Int *info)
{
	Magicolor_Scanner *s = (Magicolor_Scanner *) handle;
	SANE_Option_Descriptor *sopt = &(s->opt[option]);
	Option_Value *sval = &(s->val[option]);

	SANE_Status status;
	const SANE_String_Const *optval = NULL;
	int optindex = 0;
	SANE_Bool reload = SANE_FALSE;

	DBG(17, "%s: option = %d, value = %p, as word: %d\n", __func__, option, value, *(SANE_Word *) value);

	status = sanei_constrain_value(sopt, value, info);
	if (status != SANE_STATUS_GOOD)
		return status;

	if (info && value && (*info & SANE_INFO_INEXACT)
	    && sopt->type == SANE_TYPE_INT)
		DBG(17, "%s: constrained val = %d\n", __func__,
		    *(SANE_Word *) value);

	if (sopt->constraint_type == SANE_CONSTRAINT_STRING_LIST) {
		optval = search_string_list(sopt->constraint.string_list,
					    (char *) value);
		if (optval == NULL)
			return SANE_STATUS_INVAL;
		optindex = optval - sopt->constraint.string_list;
	}

	switch (option) {

	case OPT_MODE:
	{
		sval->w = optindex;
		/* if binary, then disable the bit depth selection */
		if (optindex == 0) {
			s->opt[OPT_BIT_DEPTH].cap |= SANE_CAP_INACTIVE;
		} else {
			if (s->hw->cap->depth_list[0] == 1)
				s->opt[OPT_BIT_DEPTH].cap |=
					SANE_CAP_INACTIVE;
			else {
				s->opt[OPT_BIT_DEPTH].cap &=
					~SANE_CAP_INACTIVE;
				s->val[OPT_BIT_DEPTH].w =
					mode_params[optindex].depth;
			}
		}
		reload = SANE_TRUE;
		break;
	}

	case OPT_BIT_DEPTH:
		sval->w = *((SANE_Word *) value);
		mode_params[s->val[OPT_MODE].w].depth = sval->w;
		reload = SANE_TRUE;
		break;

	case OPT_RESOLUTION:
		sval->w = *((SANE_Word *) value);
		DBG(17, "setting resolution to %d\n", sval->w);
		reload = SANE_TRUE;
		break;

	case OPT_BR_X:
	case OPT_BR_Y:
		if (SANE_UNFIX(*((SANE_Word *) value)) == 0) {
			DBG(17, "invalid br-x or br-y\n");
			return SANE_STATUS_INVAL;
		}
		// fall through
	case OPT_TL_X:
	case OPT_TL_Y:
		sval->w = *((SANE_Word *) value);
		DBG(17, "setting size to %f\n", SANE_UNFIX(sval->w));
		if (NULL != info)
			*info |= SANE_INFO_RELOAD_PARAMS;
		break;

	case OPT_SOURCE:
		change_source(s, optindex, (char *) value);
		reload = SANE_TRUE;
		break;

	case OPT_ADF_MODE:
		sval->w = optindex;	/* Simple lists */
		break;

	case OPT_BRIGHTNESS:
	case OPT_PREVIEW:	/* needed? */
		sval->w = *((SANE_Word *) value);
		break;

	default:
		return SANE_STATUS_INVAL;
	}

	if (reload && info != NULL)
		*info |= SANE_INFO_RELOAD_OPTIONS | SANE_INFO_RELOAD_PARAMS;

	DBG(17, "%s: end\n", __func__);

	return SANE_STATUS_GOOD;
}

SANE_Status
sane_control_option(SANE_Handle handle, SANE_Int option, SANE_Action action,
		    void *value, SANE_Int *info)
{
	DBG(17, "%s: action = %x, option = %d\n", __func__, action, option);

	if (option < 0 || option >= NUM_OPTIONS)
		return SANE_STATUS_INVAL;

	if (info != NULL)
		*info = 0;

	switch (action) {
	case SANE_ACTION_GET_VALUE:
		return getvalue(handle, option, value);

	case SANE_ACTION_SET_VALUE:
		return setvalue(handle, option, value, info);

	default:
		return SANE_STATUS_INVAL;
	}

	return SANE_STATUS_INVAL;
}

SANE_Status
sane_get_parameters(SANE_Handle handle, SANE_Parameters *params)
{
	Magicolor_Scanner *s = (Magicolor_Scanner *) handle;

	DBG(5, "%s\n", __func__);

	if (params == NULL)
		DBG(1, "%s: params is NULL\n", __func__);

	/*
	 * If sane_start was already called, then just retrieve the parameters
	 * from the scanner data structure
	 */

	if (!s->eof && s->ptr != NULL) {
		DBG(5, "scan in progress, returning saved params structure\n");
	} else {
		/* otherwise initialize the params structure and gather the data */
		mc_init_parameters(s);
	}

	if (params != NULL)
		*params = s->params;

	print_params(s->params);

	return SANE_STATUS_GOOD;
}

/*
 * This function is part of the SANE API and gets called from the front end to
 * start the scan process.
 */

SANE_Status
sane_start(SANE_Handle handle)
{
	Magicolor_Scanner *s = (Magicolor_Scanner *) handle;
	SANE_Status status;

	DBG(5, "%s\n", __func__);

	/* calc scanning parameters */
	status = mc_init_parameters(s);
	if (status != SANE_STATUS_GOOD)
		return status;

	print_params(s->params);

	/* set scanning parameters; also query the current image
	 * parameters from the sanner and save
	 * them to s->params */
	status = mc_set_scanning_parameters(s);

	if (status != SANE_STATUS_GOOD)
		return status;

	/* if we scan from ADF, check if it is loaded */
	if (strcmp(source_list[s->val[OPT_SOURCE].w], ADF_STR) == 0) {
		status = mc_check_adf(s);
		if (status != SANE_STATUS_GOOD)
			return status;
	}

	/* prepare buffer here so that a memory allocation failure
	 * will leave the scanner in a sane state.
	 */
	s->buf = realloc(s->buf, s->block_len);
	if (s->buf == NULL)
		return SANE_STATUS_NO_MEM;

	s->eof = SANE_FALSE;
	s->ptr = s->end = s->buf;
	s->canceling = SANE_FALSE;

	/* start scanning */
	DBG(1, "%s: scanning...\n", __func__);

	status = mc_start_scan(s);

	if (status != SANE_STATUS_GOOD) {
		DBG(1, "%s: start failed: %s\n", __func__,
		    sane_strstatus(status));

		return status;
	}

	return status;
}

/* this moves data from our buffers to SANE */

SANE_Status
sane_read(SANE_Handle handle, SANE_Byte *data, SANE_Int max_length,
	  SANE_Int *length)
{
	SANE_Status status;
	Magicolor_Scanner *s = (Magicolor_Scanner *) handle;

	if (s->buf == NULL || s->canceling)
		return SANE_STATUS_CANCELLED;

	*length = 0;

	status = mc_read(s);

	if (status == SANE_STATUS_CANCELLED) {
		mc_scan_finish(s);
		return status;
	}

	DBG(18, "moving data %p %p, %d (%d lines)\n",
		(void *) s->ptr, (void *) s->end,
		max_length, max_length / s->params.bytes_per_line);

	mc_copy_image_data(s, data, max_length, length);

	DBG(18, "%d lines read, status: %d\n",
		*length / s->params.bytes_per_line, status);

	/* continue reading if appropriate */
	if (status == SANE_STATUS_GOOD)
		return status;

	mc_scan_finish(s);

	return status;
}

/*
 * void sane_cancel(SANE_Handle handle)
 *
 * Set the cancel flag to true. The next time the backend requests data
 * from the scanner the CAN message will be sent.
 */

void
sane_cancel(SANE_Handle handle)
{
	Magicolor_Scanner *s = (Magicolor_Scanner *) handle;

	s->canceling = SANE_TRUE;
}

/*
 * SANE_Status sane_set_io_mode()
 *
 * not supported - for asynchronous I/O
 */

SANE_Status
sane_set_io_mode(SANE_Handle __sane_unused__ handle,
	SANE_Bool __sane_unused__ non_blocking)
{
	return SANE_STATUS_UNSUPPORTED;
}

/*
 * SANE_Status sane_get_select_fd()
 *
 * not supported - for asynchronous I/O
 */

SANE_Status
sane_get_select_fd(SANE_Handle __sane_unused__ handle,
	SANE_Int __sane_unused__ *fd)
{
	return SANE_STATUS_UNSUPPORTED;
}