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/* file.c - file I/O functions */
/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2002,2006,2007,2009 Free Software Foundation, Inc.
*
* GRUB 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 3 of the License, or
* (at your option) any later version.
*
* GRUB 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 GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#include <grub/misc.h>
#include <grub/err.h>
#include <grub/file.h>
#include <grub/net.h>
#include <grub/mm.h>
#include <grub/fs.h>
#include <grub/device.h>
#include <grub/i18n.h>
void (*EXPORT_VAR (grub_grubnet_fini)) (void);
grub_file_filter_t grub_file_filters[GRUB_FILE_FILTER_MAX];
/* Get the device part of the filename NAME. It is enclosed by parentheses. */
char *
grub_file_get_device_name (const char *name)
{
if (name[0] == '(')
{
char *p = grub_strchr (name, ')');
char *ret;
if (! p)
{
grub_error (GRUB_ERR_BAD_FILENAME, N_("missing `%c' symbol"), ')');
return 0;
}
ret = (char *) grub_malloc (p - name);
if (! ret)
return 0;
grub_memcpy (ret, name + 1, p - name - 1);
ret[p - name - 1] = '\0';
return ret;
}
return 0;
}
grub_file_t
grub_file_open (const char *name, enum grub_file_type type)
{
grub_device_t device = 0;
grub_file_t file = 0, last_file = 0;
char *device_name;
const char *file_name;
grub_file_filter_id_t filter;
device_name = grub_file_get_device_name (name);
if (grub_errno)
goto fail;
/* Get the file part of NAME. */
file_name = (name[0] == '(') ? grub_strchr (name, ')') : NULL;
if (file_name)
file_name++;
else
file_name = name;
device = grub_device_open (device_name);
grub_free (device_name);
if (! device)
goto fail;
file = (grub_file_t) grub_zalloc (sizeof (*file));
if (! file)
goto fail;
file->device = device;
/* In case of relative pathnames and non-Unix systems (like Windows)
* name of host files may not start with `/'. Blocklists for host files
* are meaningless as well (for a start, host disk does not allow any direct
* access - it is just a marker). So skip host disk in this case.
*/
if (device->disk && file_name[0] != '/'
#if defined(GRUB_UTIL) || defined(GRUB_MACHINE_EMU)
&& grub_strcmp (device->disk->name, "host")
#endif
)
/* This is a block list. */
file->fs = &grub_fs_blocklist;
else
{
file->fs = grub_fs_probe (device);
if (! file->fs)
goto fail;
}
if ((file->fs->fs_open) (file, file_name) != GRUB_ERR_NONE)
goto fail;
file->name = grub_strdup (name);
grub_errno = GRUB_ERR_NONE;
for (filter = 0; file && filter < ARRAY_SIZE (grub_file_filters);
filter++)
if (grub_file_filters[filter])
{
last_file = file;
file = grub_file_filters[filter] (file, type);
if (file && file != last_file)
{
file->name = grub_strdup (name);
grub_errno = GRUB_ERR_NONE;
}
}
if (!file)
grub_file_close (last_file);
return file;
fail:
if (device)
grub_device_close (device);
/* if (net) grub_net_close (net); */
grub_free (file);
return 0;
}
grub_disk_read_hook_t grub_file_progress_hook;
grub_ssize_t
grub_file_read (grub_file_t file, void *buf, grub_size_t len)
{
grub_ssize_t res;
grub_disk_read_hook_t read_hook;
void *read_hook_data;
if (file->offset > file->size)
{
grub_error (GRUB_ERR_OUT_OF_RANGE,
N_("attempt to read past the end of file"));
return -1;
}
if (len == 0)
return 0;
if (len > file->size - file->offset)
len = file->size - file->offset;
/* Prevent an overflow. */
if ((grub_ssize_t) len < 0)
len >>= 1;
if (len == 0)
return 0;
read_hook = file->read_hook;
read_hook_data = file->read_hook_data;
if (!file->read_hook)
{
file->read_hook = grub_file_progress_hook;
file->read_hook_data = file;
file->progress_offset = file->offset;
}
res = (file->fs->fs_read) (file, buf, len);
file->read_hook = read_hook;
file->read_hook_data = read_hook_data;
if (res > 0)
file->offset += res;
return res;
}
grub_err_t
grub_file_close (grub_file_t file)
{
if (file->fs->fs_close)
(file->fs->fs_close) (file);
if (file->device)
grub_device_close (file->device);
grub_free (file->name);
grub_free (file);
return grub_errno;
}
grub_off_t
grub_file_seek (grub_file_t file, grub_off_t offset)
{
grub_off_t old;
if (offset > file->size)
{
grub_error (GRUB_ERR_OUT_OF_RANGE,
N_("attempt to seek outside of the file"));
return -1;
}
old = file->offset;
file->offset = offset;
return old;
}
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