/*
* Copyright © 2014 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#include <string.h>
#include "main/macros.h"
#include "util/ralloc.h"
#include "blob.h"
#define BLOB_INITIAL_SIZE 4096
/* Ensure that \blob will be able to fit an additional object of size
* \additional. The growing (if any) will occur by doubling the existing
* allocation.
*/
static bool
grow_to_fit(struct blob *blob, size_t additional)
{
size_t to_allocate;
uint8_t *new_data;
if (blob->size + additional <= blob->allocated)
return true;
if (blob->allocated == 0)
to_allocate = BLOB_INITIAL_SIZE;
else
to_allocate = blob->allocated * 2;
to_allocate = MAX2(to_allocate, blob->allocated + additional);
new_data = reralloc_size(blob, blob->data, to_allocate);
if (new_data == NULL)
return false;
blob->data = new_data;
blob->allocated = to_allocate;
return true;
}
/* Align the blob->size so that reading or writing a value at (blob->data +
* blob->size) will result in an access aligned to a granularity of \alignment
* bytes.
*
* \return True unless allocation fails
*/
static bool
align_blob(struct blob *blob, size_t alignment)
{
const size_t new_size = ALIGN(blob->size, alignment);
if (! grow_to_fit (blob, new_size - blob->size))
return false;
blob->size = new_size;
return true;
}
static void
align_blob_reader(struct blob_reader *blob, size_t alignment)
{
blob->current = blob->data + ALIGN(blob->current - blob->data, alignment);
}
struct blob *
blob_create(void *mem_ctx)
{
struct blob *blob;
blob = ralloc(mem_ctx, struct blob);
if (blob == NULL)
return NULL;
blob->data = NULL;
blob->allocated = 0;
blob->size = 0;
return blob;
}
bool
blob_overwrite_bytes(struct blob *blob,
size_t offset,
const void *bytes,
size_t to_write)
{
/* Detect an attempt to overwrite data out of bounds. */
if (offset < 0 || blob->size - offset < to_write)
return false;
memcpy(blob
->data
+ offset
, bytes
, to_write
);
return true;
}
bool
blob_write_bytes(struct blob *blob, const void *bytes, size_t to_write)
{
if (! grow_to_fit(blob, to_write))
return false;
memcpy(blob
->data
+ blob
->size
, bytes
, to_write
); blob->size += to_write;
return true;
}
uint8_t *
blob_reserve_bytes(struct blob *blob, size_t to_write)
{
uint8_t *ret;
if (! grow_to_fit (blob, to_write))
return NULL;
ret = blob->data + blob->size;
blob->size += to_write;
return ret;
}
bool
blob_write_uint32(struct blob *blob, uint32_t value)
{
align_blob(blob, sizeof(value));
return blob_write_bytes(blob, &value, sizeof(value));
}
bool
blob_overwrite_uint32 (struct blob *blob,
size_t offset,
uint32_t value)
{
return blob_overwrite_bytes(blob, offset, &value, sizeof(value));
}
bool
blob_write_uint64(struct blob *blob, uint64_t value)
{
align_blob(blob, sizeof(value));
return blob_write_bytes(blob, &value, sizeof(value));
}
bool
blob_write_intptr(struct blob *blob, intptr_t value)
{
align_blob(blob, sizeof(value));
return blob_write_bytes(blob, &value, sizeof(value));
}
bool
blob_write_string(struct blob *blob, const char *str)
{
return blob_write_bytes
(blob
, str
, strlen(str
) + 1); }
void
blob_reader_init(struct blob_reader *blob, uint8_t *data, size_t size)
{
blob->data = data;
blob->end = data + size;
blob->current = data;
blob->overrun = false;
}
/* Check that an object of size \size can be read from this blob.
*
* If not, set blob->overrun to indicate that we attempted to read too far.
*/
static bool
ensure_can_read(struct blob_reader *blob, size_t size)
{
if (blob->current < blob->end && blob->end - blob->current >= size)
return true;
blob->overrun = true;
return false;
}
void *
blob_read_bytes(struct blob_reader *blob, size_t size)
{
void *ret;
if (! ensure_can_read (blob, size))
return NULL;
ret = blob->current;
blob->current += size;
return ret;
}
void
blob_copy_bytes(struct blob_reader *blob, uint8_t *dest, size_t size)
{
uint8_t *bytes;
bytes = blob_read_bytes(blob, size);
if (bytes == NULL)
return;
}
/* These next three read functions have identical form. If we add any beyond
* these first three we should probably switch to generating these with a
* preprocessor macro.
*/
uint32_t
blob_read_uint32(struct blob_reader *blob)
{
uint32_t ret;
int size = sizeof(ret);
align_blob_reader(blob, size);
if (! ensure_can_read(blob, size))
return 0;
ret = *((uint32_t*) blob->current);
blob->current += size;
return ret;
}
uint64_t
blob_read_uint64(struct blob_reader *blob)
{
uint64_t ret;
int size = sizeof(ret);
align_blob_reader(blob, size);
if (! ensure_can_read(blob, size))
return 0;
ret = *((uint64_t*) blob->current);
blob->current += size;
return ret;
}
intptr_t
blob_read_intptr(struct blob_reader *blob)
{
intptr_t ret;
int size = sizeof(ret);
align_blob_reader(blob, size);
if (! ensure_can_read(blob, size))
return 0;
ret = *((intptr_t *) blob->current);
blob->current += size;
return ret;
}
char *
blob_read_string(struct blob_reader *blob)
{
int size;
char *ret;
uint8_t *nul;
/* If we're already at the end, then this is an overrun. */
if (blob->current >= blob->end) {
blob->overrun = true;
return NULL;
}
/* Similarly, if there is no zero byte in the data remaining in this blob,
* we also consider that an overrun.
*/
nul
= memchr(blob
->current
, 0, blob
->end
- blob
->current
);
if (nul == NULL) {
blob->overrun = true;
return NULL;
}
size = nul - blob->current + 1;
assert(ensure_can_read
(blob
, size
));
ret = (char *) blob->current;
blob->current += size;
return ret;
}