sane-project-backends/sanei/sanei_usb.c

/* sane - Scanner Access Now Easy.
   Copyright (C) 2001 Henning Meier-Geinitz
   Copyright (C) 2001 Frank Zago (sanei_usb_control_msg)
   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; either version 2 of the
   License, or (at your option) any later version.

   This program is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330, Boston,
   MA 02111-1307, USA.

   As a special exception, the authors of SANE give permission for
   additional uses of the libraries contained in this release of SANE.

   The exception is that, if you link a SANE library with other files
   to produce an executable, this does not by itself cause the
   resulting executable to be covered by the GNU General Public
   License.  Your use of that executable is in no way restricted on
   account of linking the SANE library code into it.

   This exception does not, however, invalidate any other reasons why
   the executable file might be covered by the GNU General Public
   License.

   If you submit changes to SANE to the maintainers to be included in
   a subsequent release, you agree by submitting the changes that
   those changes may be distributed with this exception intact.

   If you write modifications of your own for SANE, it is your choice
   whether to permit this exception to apply to your modifications.
   If you do not wish that, delete this exception notice.

   This file provides a generic (?) USB interface.  */

#include "../include/sane/config.h"

#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <stdio.h>

#define BACKEND_NAME	sanei_usb
#include "../include/sane/sane.h"
#include "../include/sane/sanei_debug.h"
#include "../include/sane/sanei_usb.h"
#include "../include/sane/sanei_config.h"

#if defined (__linux__)

/* From /usr/src/linux/driver/usb/scanner.h */
#define SCANNER_IOCTL_VENDOR _IOR('U', 0x20, int)
#define SCANNER_IOCTL_PRODUCT _IOR('U', 0x21, int)
#define SCANNER_IOCTL_CTRLMSG _IOWR('U', 0x22, devrequest)
/* Older (unofficial) IOCTL numbers for Linux < v2.4.13 */
#define SCANNER_IOCTL_VENDOR_OLD _IOR('u', 0xa0, int)
#define SCANNER_IOCTL_PRODUCT_OLD _IOR('u', 0xa1, int)

/* From /usr/src/linux/include/linux/usb.h */ 
typedef struct {
  unsigned char requesttype;
  unsigned char request;
  unsigned short value;
  unsigned short index;
  unsigned short length;
} devrequest __attribute__ ((packed));

/* From /usr/src/linux/driver/usb/scanner.h */
struct ctrlmsg_ioctl {
  devrequest  req;
  void        *data;
} cmsg;

#endif /* __linux__ */


void
sanei_usb_init (void)
{
  DBG_INIT();
}

/* This logically belongs to sanei_config.c but not every backend that
   uses sanei_config() wants to depend on sanei_usb.  */
void
sanei_usb_attach_matching_devices (const char *name,
				   SANE_Status (*attach) (const char *dev))
{
  char *vendor, *product;

  if (strncmp (name, "usb", 3) == 0)
    {
      SANE_Word vendorID = 0, productID = 0;

      name += 3;

      name = sanei_config_skip_whitespace (name);
      if (*name)
	{
	  name = sanei_config_get_string (name, &vendor);
	  if (vendor)
	    {
	      vendorID = strtol (vendor, 0, 0);
	      free (vendor);
	    }
	  name = sanei_config_skip_whitespace (name);
	}

      name = sanei_config_skip_whitespace (name);
      if (*name)
	{
	  name = sanei_config_get_string (name, &product);
	  if (product)
	    {
	      productID = strtol (product, 0, 0);
	      free (product);
	    }
	}
      sanei_usb_find_devices (vendorID, productID, attach);
    }
  else 
    (*attach) (name);
}

SANE_Status
sanei_usb_get_vendor_product (SANE_Int fd, SANE_Word * vendor,
			      SANE_Word * product)
{
  SANE_Word vendorID, productID;

#if defined (__linux__)
  /* read the vendor and product IDs via the IOCTLs */
  if (ioctl (fd, SCANNER_IOCTL_VENDOR , &vendorID) == -1)
    {
      if (ioctl (fd, SCANNER_IOCTL_VENDOR_OLD , &vendorID) == -1)
	{
	  DBG (3, "sanei_usb_get_vendor_product: ioctl (vendor) of fd %d "
	       "failed: %s\n", fd, strerror (errno));
	  /* just set the vendor ID to 0 */
	  vendorID = 0;
	}
    }
  if (ioctl (fd, SCANNER_IOCTL_PRODUCT , &productID) == -1)
    {
      if (ioctl (fd, SCANNER_IOCTL_PRODUCT_OLD , &productID) == -1)
	{
	  DBG (3, "sanei_usb_get_vendor_product: ioctl (product) of fd %d "
	       "failed: %s\n", fd, strerror (errno));
	  /* just set the product ID to 0 */
	  productID = 0;
	}
    }
  if (vendor)
    *vendor = vendorID;
  if (product)
    *product = productID;
#else /* not defined (__linux__) */
  vendorID = 0;
  productID = 0;
#endif /* not defined (__linux__) */

  if (!vendorID || !productID)
    {
      DBG (3, "sanei_usb_get_vendor_product: fd %d: Your OS doesn't seem to "
	   "support detection of vendor+product ids\n",
	   fd);

      return SANE_STATUS_UNSUPPORTED;
    }
  else
    {
      DBG (3, "sanei_usb_get_vendor_product: fd %d: vendorID: 0x%x, "
	   "productID: 0x%x\n", fd, vendorID, productID);
      return SANE_STATUS_GOOD;
    }
}


static SANE_Status
check_vendor_product (SANE_String_Const devname, SANE_Word vendor,
		      SANE_Word product,
		      SANE_Status (*attach) (SANE_String_Const dev))
{
  SANE_Status status;
  SANE_Word devvendor, devproduct;
  SANE_Int fd;

  status = sanei_usb_open (devname, &fd);
  if (status != SANE_STATUS_GOOD)
    return status;

  status = sanei_usb_get_vendor_product (fd, &devvendor, &devproduct);
  sanei_usb_close (fd);
  if (status == SANE_STATUS_GOOD)
    {
      if (devvendor == vendor && devproduct == product)
	{
	  if (attach)
	    attach (devname);
	}
    }
  return status;
}

SANE_Status
sanei_usb_find_devices (SANE_Int vendor, SANE_Int product,
			SANE_Status (*attach) (SANE_String_Const dev))
{
  SANE_String *prefix;
  SANE_String prefixlist[] = {
#if defined(__linux__)
    "/dev/usbscanner",
    "/dev/usb/scanner",
#elif defined(__FreeBSD__)
    "/dev/uscanner",
#endif
    0};
  SANE_Char devname[30];
  int devcount;
  SANE_Status status;

#define SANEI_USB_MAX_DEVICES 16

  DBG (3, "sanei_usb_find_devices: vendor=0x%x, product=0x%x, attach=%p\n",
       vendor, product, attach);

  for (prefix = prefixlist; *prefix; prefix++)
    {
      status = check_vendor_product (*prefix, vendor, product, attach);
      if (status == SANE_STATUS_UNSUPPORTED)
	return status; /* give up if we can't detect vendor/product */
      for (devcount = 0; devcount < SANEI_USB_MAX_DEVICES; 
	   devcount++)
	{
	  snprintf (devname, sizeof (devname), "%s%d", *prefix,
		    devcount);
	  status = check_vendor_product (devname, vendor, product, attach);
	  if (status == SANE_STATUS_UNSUPPORTED)
	    return status; /* give up if we can't detect vendor/product */
	}
    }
  return SANE_STATUS_GOOD;
}

SANE_Status
sanei_usb_open (SANE_String_Const devname, SANE_Int *fd)
{
  if (!fd)
    {
      DBG (1, "sanei_usb_open: fd == NULL\n");
      return SANE_STATUS_INVAL;
    }
  *fd = open (devname, O_RDWR);
  if (*fd < 0)
    {
      SANE_Status status = SANE_STATUS_INVAL;

      DBG (1, "sanei_usb_open: open failed: %s\n", strerror (errno));
      if (errno == EACCES)
	status = SANE_STATUS_ACCESS_DENIED;
      return status;
    }
  DBG (5, "sanei_usb_open: fd %d opened\n", *fd);
  return SANE_STATUS_GOOD;
}

void
sanei_usb_close (SANE_Int fd)
{
  DBG (5, "sanei_usb_close: closing fd %d\n", fd);
  close (fd);
  return;
}

SANE_Status
sanei_usb_read_bulk (SANE_Int fd, SANE_Byte * buffer, size_t *size)
{
  ssize_t read_size;

  if (!size)
    {
      DBG (1, "sanei_usb_read_bulk: size == NULL\n");
      return SANE_STATUS_INVAL;
    }

  read_size = read (fd, buffer, *size);
  if (read_size < 0)
    {
      DBG (1, "sanei_usb_read_bulk: read failed: %s\n", strerror (errno));
      *size = 0;
      return SANE_STATUS_IO_ERROR;
    }
  if (read_size == 0)
    {
      DBG (3, "sanei_usb_read_bulk: read returned EOF\n");
      *size = 0;
      return SANE_STATUS_EOF;
    }
  DBG (5, "sanei_usb_read_bulk: wanted %lu bytes, got %ld bytes\n",
	 (unsigned long) *size, (unsigned long) read_size);
  *size = read_size;
  return SANE_STATUS_GOOD;
}

SANE_Status
sanei_usb_write_bulk (SANE_Int fd, SANE_Byte * buffer, size_t *size)
{
  ssize_t write_size;

  if (!size)
    {
      DBG (1, "sanei_usb_write_bulk: size == NULL\n");
      return SANE_STATUS_INVAL;
    }

  write_size = write (fd, buffer, *size);
  if (write_size < 0)
    {
      DBG (1, "sanei_usb_write_bulk: write failed: %s\n", strerror (errno));
      *size = 0;
      return SANE_STATUS_IO_ERROR;
    }
  DBG (5, "sanei_usb_write_bulk: wanted %lu bytes, wrote %ld bytes\n",
	 (unsigned long) *size, (unsigned long) write_size);
  *size = write_size;
  return SANE_STATUS_GOOD;
}

SANE_Status
sanei_usb_control_msg(SANE_Int fd, SANE_Int rtype, SANE_Int req,
		      SANE_Int value, SANE_Int index, SANE_Int len,
		      SANE_Byte *data )
{
#if defined(__linux__)
  struct ctrlmsg_ioctl c;

  c.req.requesttype = rtype;
  c.req.request = req;
  c.req.value = value;
  c.req.index = index;
  c.req.length = len;
  c.data = data;

  DBG(5, "sanei_usb_control_msg: rtype = 0x%02x, req = %d, value = %d, "
      "index = %d, len = %d\n", rtype, req, value, index, len);
  
  if (ioctl(fd, SCANNER_IOCTL_CTRLMSG, &c) < 0)
    {
      DBG(5, "sanei_usb_control_msg: SCANNER_IOCTL_CTRLMSG error - %s\n",
	  strerror(errno));
      return SANE_STATUS_IO_ERROR;
    }
  return SANE_STATUS_GOOD;
#else
  DBG (5, "sanei_usb_control_msg: not supported on this OS\n");
  return SANE_STATUS_UNSUPPORTED;
#endif /* __linux__ */
}