/* channel.c -- device communication channel
* Copyright (C) 2008, 2009, 2013 SEIKO EPSON CORPORATION
*
* License: GPLv2+|iscan
* Authors: AVASYS CORPORATION
*
* This file is part of the SANE backend distributed with Image Scan!
*
* Image Scan!'s SANE backend 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 ought to have received a copy of the GNU General Public License
* along with this package. If not, see .
*
*
* Linking Image Scan!'s SANE backend statically or dynamically with
* other modules is making a combined work based on this SANE backend.
* Thus, the terms and conditions of the GNU General Public License
* cover the whole combination.
*
* As a special exception, the copyright holders of Image Scan!'s SANE
* backend give you permission to link Image Scan!'s SANE backend with
* SANE frontends that communicate with Image Scan!'s SANE backend
* solely through the SANE Application Programming Interface,
* regardless of the license terms of these SANE frontends, and to
* copy and distribute the resulting combined work under terms of your
* choice, provided that every copy of the combined work is
* accompanied by a complete copy of the source code of Image Scan!'s
* SANE backend (the version of Image Scan!'s SANE backend used to
* produce the combined work), being distributed under the terms of
* the GNU General Public License plus this exception. An independent
* module is a module which is not derived from or based on Image
* Scan!'s SANE backend.
*
* As a special exception, the copyright holders of Image Scan!'s SANE
* backend give you permission to link Image Scan!'s SANE backend with
* independent modules that communicate with Image Scan!'s SANE
* backend solely through the "Interpreter" interface, regardless of
* the license terms of these independent modules, and to copy and
* distribute the resulting combined work under terms of your choice,
* provided that every copy of the combined work is accompanied by a
* complete copy of the source code of Image Scan!'s SANE backend (the
* version of Image Scan!'s SANE backend used to produce the combined
* work), being distributed under the terms of the GNU General Public
* License plus this exception. An independent module is a module
* which is not derived from or based on Image Scan!'s SANE backend.
*
* Note that people who make modified versions of Image Scan!'s SANE
* backend are not obligated to grant special exceptions for their
* modified versions; it is their choice whether to do so. The GNU
* General Public License gives permission to release a modified
* version without this exception; this exception also makes it
* possible to release a modified version which carries forward this
* exception.
*/
/*! \file
\brief Implements a hardware communication channel.
Hardware channels supported are usb, scsi and parallel.
*/
#ifdef HAVE_CONFIG_H
#include
#endif
#define USE_PROTECTED_CHANNEL_API
#include "channel.h"
#include "utils.h"
extern channel *
channel_net_ctor (channel *self, const char *dev_name, SANE_Status *status);
extern channel *
channel_pio_ctor (channel *self, const char *dev_name, SANE_Status *status);
extern channel *
channel_scsi_ctor (channel *self, const char *dev_name, SANE_Status *status);
extern channel *
channel_usb_ctor (channel *self, const char *dev_name, SANE_Status *status);
extern channel *
channel_interpreter_ctor (channel *self,
const char *dev_name, SANE_Status *status);
#include
#include "epkowa_ip.h"
#include "hw-data.h"
/*! A ::channel factory method.
*
* Creates and initializes a channel object to match a \a dev_name.
*
* \todo Validate \a dev_name?
*/
channel *
channel_create (const char *dev_name, SANE_Status *status)
{
channel *ch = NULL;
require (dev_name);
if (status) *status = SANE_STATUS_GOOD;
ch = t_calloc (1, channel);
if (!ch)
{
if (status) *status = SANE_STATUS_NO_MEM;
return NULL;
}
ch->dtor = channel_dtor;
ch->is_open = channel_is_open;
ch->max_request_size = channel_max_request_size;
ch->set_max_request_size = channel_set_max_request_size;
ch->fd = -1;
ch->id = 0;
ch->max_size = 32 * 1024;
if (0 == strncmp_c (dev_name, "net:", strlen ("net:")))
{
ch->ctor = channel_net_ctor;
ch->type = CHAN_NET;
}
if (0 == strncmp_c (dev_name, "pio:", strlen ("pio:")))
{
ch->ctor = channel_pio_ctor;
ch->type = CHAN_PIO;
}
if (0 == strncmp_c (dev_name, "scsi:", strlen ("scsi:")))
{
ch->ctor = channel_scsi_ctor;
ch->type = CHAN_SCSI;
}
if (0 == strncmp_c (dev_name, "usb:", strlen ("usb:")))
{
ch->ctor = channel_usb_ctor;
ch->type = CHAN_USB;
}
if (0 == strncmp_c (dev_name, "interpreter:", strlen ("interpreter:")))
{
ch->ctor = channel_interpreter_ctor;
ch->type = CHAN_INTERP;
}
if (!ch->ctor)
{
err_major ("unsupported channel for '%s'", dev_name);
if (status) *status = SANE_STATUS_UNSUPPORTED;
delete (ch);
return NULL;
}
return ch->ctor (ch, dev_name, status);
}
/*! Logging wrapper around a channel's send() method.
*/
ssize_t
channel_send (channel* ch, const void *buffer, size_t size,
SANE_Status *status)
{
ssize_t n = 0;
log_call ("(%zd)", size);
dbg_hex (buffer, size);
n = ch->send (ch, buffer, size, status);
log_call ("transferred %zd bytes", n);
return n;
}
/*! Logging wrapper around a channel's recv() method.
*/
ssize_t
channel_recv (channel *ch, void *buffer, size_t size, SANE_Status *status)
{
ssize_t n = 0;
log_call ("(%zd)", size);
if (size < 256)
memset (buffer, 0x00, size);
n = ch->recv (ch, buffer, size, status);
if (0 < n)
{
if (size < 256)
{ dbg_hex (buffer, n); }
else
{ dbg_img (buffer, n); }
}
log_call ("transferred %zd bytes", n);
return n;
}
/*! Throttle the number of bytes read in a single go
*/
static ssize_t
channel_recv_throttle (channel *ch, void *buffer, size_t size,
SANE_Status *status)
{
size_t max = ch->max_request_size (ch);
return ch->recv (ch, buffer, size < max ? size : max, status);
}
ssize_t channel_recv_all (channel *ch, void *buffer,
size_t size, SANE_Status *status)
{
return channel_recv_all_retry (ch, buffer, size, 1, status);
}
ssize_t
channel_recv_all_retry (channel *ch, void *buffer, size_t size,
size_t max_attempts, SANE_Status *status)
{
SANE_Status s = SANE_STATUS_GOOD;
ssize_t n = 0;
ssize_t t = 0;
size_t attempts = 0;
log_call ("(%zd)", size);
while (n < size && attempts < max_attempts)
{
t = channel_recv_throttle (ch, buffer + n, size - n, &s);
if (SANE_STATUS_GOOD != s || 0 >= t)
{
++attempts;
log_info ("attempts: %zd/%zd", attempts, max_attempts);
}
if (0 < t) n += t;
log_call ("transferred %zd bytes, total %zd/%zd", t, n, size);
}
if (0 < n)
{
if (size < 256)
{ dbg_hex (buffer, n); }
else
{ dbg_img (buffer, n); }
}
if (status) *status = s;
return n;
}
/*! Tells whether a channel is ready to send() and recv() data.
*/
bool
channel_is_open (const struct channel *self)
{
return (self && 0 <= self->fd);
}
/*! Indicates the maximum number of bytes the channel should read
* in a singe request.
*/
size_t
channel_max_request_size (const struct channel *self)
{
require (self);
return self->max_size;
}
/*! Change the maximum number of bytes a channel should read in a
* single request.
*/
void
channel_set_max_request_size (struct channel *self, size_t size)
{
require (self);
self->max_size = size;
}
/*! "Base class" destructor.
*/
channel *
channel_dtor (struct channel *self)
{
SANE_Status status = SANE_STATUS_GOOD;
log_call ("(fd = %d)", self->fd);
if (!self) return NULL;
if (self->interpreter) self->interpreter->dtor (self);
if (self->is_open (self))
{
self->close (self, &status);
}
delete (self->name);
delete (self);
return NULL;
}