120 lines
2.6 KiB
C
120 lines
2.6 KiB
C
/*
|
|
* GRUB -- GRand Unified Bootloader
|
|
* Copyright (C) 2021 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/buffer.h>
|
|
#include <grub/err.h>
|
|
#include <grub/misc.h>
|
|
#include <grub/mm.h>
|
|
#include <grub/safemath.h>
|
|
#include <grub/types.h>
|
|
|
|
grub_buffer_t
|
|
grub_buffer_new (grub_size_t sz)
|
|
{
|
|
struct grub_buffer *ret;
|
|
|
|
ret = (struct grub_buffer *) grub_malloc (sizeof (*ret));
|
|
if (ret == NULL)
|
|
return NULL;
|
|
|
|
ret->data = (grub_uint8_t *) grub_malloc (sz);
|
|
if (ret->data == NULL)
|
|
{
|
|
grub_free (ret);
|
|
return NULL;
|
|
}
|
|
|
|
ret->sz = sz;
|
|
ret->pos = 0;
|
|
ret->used = 0;
|
|
|
|
return ret;
|
|
}
|
|
|
|
void
|
|
grub_buffer_free (grub_buffer_t buf)
|
|
{
|
|
if (buf != NULL)
|
|
{
|
|
grub_free (buf->data);
|
|
grub_free (buf);
|
|
}
|
|
}
|
|
|
|
grub_err_t
|
|
grub_buffer_ensure_space (grub_buffer_t buf, grub_size_t req)
|
|
{
|
|
grub_uint8_t *d;
|
|
grub_size_t newsz = 1;
|
|
|
|
/* Is the current buffer size adequate? */
|
|
if (buf->sz >= req)
|
|
return GRUB_ERR_NONE;
|
|
|
|
/* Find the smallest power-of-2 size that satisfies the request. */
|
|
while (newsz < req)
|
|
{
|
|
if (newsz == 0)
|
|
return grub_error (GRUB_ERR_OUT_OF_RANGE,
|
|
N_("requested buffer size is too large"));
|
|
newsz <<= 1;
|
|
}
|
|
|
|
d = (grub_uint8_t *) grub_realloc (buf->data, newsz);
|
|
if (d == NULL)
|
|
return grub_errno;
|
|
|
|
buf->data = d;
|
|
buf->sz = newsz;
|
|
|
|
return GRUB_ERR_NONE;
|
|
}
|
|
|
|
void *
|
|
grub_buffer_take_data (grub_buffer_t buf)
|
|
{
|
|
void *data = buf->data;
|
|
|
|
buf->data = NULL;
|
|
buf->sz = buf->pos = buf->used = 0;
|
|
|
|
return data;
|
|
}
|
|
|
|
void
|
|
grub_buffer_reset (grub_buffer_t buf)
|
|
{
|
|
buf->pos = buf->used = 0;
|
|
}
|
|
|
|
grub_err_t
|
|
grub_buffer_advance_read_pos (grub_buffer_t buf, grub_size_t n)
|
|
{
|
|
grub_size_t newpos;
|
|
|
|
if (grub_add (buf->pos, n, &newpos))
|
|
return grub_error (GRUB_ERR_OUT_OF_RANGE, N_("overflow is detected"));
|
|
|
|
if (newpos > buf->used)
|
|
return grub_error (GRUB_ERR_OUT_OF_RANGE,
|
|
N_("new read is position beyond the end of the written data"));
|
|
|
|
buf->pos = newpos;
|
|
|
|
return GRUB_ERR_NONE;
|
|
}
|