/* append area to existing structure, return new total size if successful */
int fmap_append_area(struct fmap **fmap,
uint32_t offset, uint32_t size,
const uint8_t *name, uint16_t flags)
{
struct fmap_area *area;
int orig_size, new_size;
if ((fmap == NULL || *fmap == NULL) || (name == NULL))
return -1;
/* too many areas */
if ((*fmap)->nareas >= 0xffff)
return -1;
orig_size = fmap_size(*fmap);
new_size = orig_size + sizeof(*area);
*fmap = realloc(*fmap, new_size);
if (*fmap == NULL)
return -1;
area = (struct fmap_area *)((uint8_t *)*fmap + orig_size);
memset(area, 0, sizeof(*area));
memcpy(&area->offset, &offset, sizeof(area->offset));
memcpy(&area->size, &size, sizeof(area->size));
memccpy(&area->name, name, '\0', FMAP_STRLEN);
memcpy(&area->flags, &flags, sizeof(area->flags));
(*fmap)->nareas++;
return new_size;
}
partitioned_file_t *partitioned_file_create(const char *filename,
struct buffer *flashmap)
{
assert(filename);
assert(flashmap);
assert(flashmap->data);
if (fmap_find((const uint8_t *)flashmap->data, flashmap->size) != 0) {
ERROR("Attempted to create a partitioned image out of something that isn't an FMAP\n");
return NULL;
}
struct fmap *bootstrap_fmap = (struct fmap *)flashmap->data;
const struct fmap_area *fmap_area =
fmap_find_area(bootstrap_fmap, SECTION_NAME_FMAP);
if (!fmap_area) {
ERROR("Provided FMAP missing '%s' region\n", SECTION_NAME_FMAP);
return NULL;
}
if (count_selected_fmap_entries(bootstrap_fmap,
partitioned_file_fmap_select_children_of, fmap_area)) {
ERROR("Provided FMAP's '%s' region contains other regions\n",
SECTION_NAME_FMAP);
return NULL;
}
int fmap_len = fmap_size(bootstrap_fmap);
if (fmap_len < 0) {
ERROR("Unable to determine size of provided FMAP\n");
return NULL;
}
assert((size_t)fmap_len <= flashmap->size);
if ((uint32_t)fmap_len > fmap_area->size) {
ERROR("Provided FMAP's '%s' region needs to be at least %d bytes\n",
SECTION_NAME_FMAP, fmap_len);
return NULL;
}
partitioned_file_t *file = partitioned_file_create_flat(filename,
bootstrap_fmap->size);
if (!file)
return NULL;
struct buffer fmap_region;
buffer_splice(&fmap_region, &file->buffer, fmap_area->offset, fmap_area->size);
memcpy(fmap_region.data, bootstrap_fmap, fmap_len);
if (!partitioned_file_write_region(file, &fmap_region)) {
partitioned_file_close(file);
return NULL;
}
file->fmap = (struct fmap *)(file->buffer.data + fmap_area->offset);
return file;
}
static int fmap_size_test(void)
{
status = fail;
if (fmap_size(NULL) >= 0) {
printf("FAILURE: failed to abort on NULL pointer input\n");
goto fmap_size_test_exit;
}
status = pass;
fmap_size_test_exit:
return status;
}
partitioned_file_t *partitioned_file_reopen(const char *filename,
partitioned_file_flat_decider_t flat_override)
{
assert(filename);
partitioned_file_t *file = reopen_flat_file(filename);
if (!file)
return NULL;
if (flat_override && flat_override(&file->buffer)) {
INFO("Opening image as a flat file in response to explicit request\n");
return file;
}
long fmap_region_offset = fmap_find((const uint8_t *)file->buffer.data,
file->buffer.size);
if (fmap_region_offset < 0) {
INFO("Opening image as a flat file because it doesn't contain any FMAP\n");
return file;
}
file->fmap = (struct fmap *)(file->buffer.data + fmap_region_offset);
if (file->fmap->size > file->buffer.size) {
int fmap_region_size = fmap_size(file->fmap);
ERROR("FMAP records image size as %u, but file is only %zu bytes%s\n",
file->fmap->size, file->buffer.size,
fmap_region_offset == 0 &&
(signed)file->buffer.size == fmap_region_size ?
" (is it really an image, or *just* an FMAP?)" :
" (did something truncate this file?)");
partitioned_file_close(file);
return NULL;
}
const struct fmap_area *fmap_fmap_entry =
fmap_find_area(file->fmap, SECTION_NAME_FMAP);
if ((long)fmap_fmap_entry->offset != fmap_region_offset) {
ERROR("FMAP's '%s' section doesn't point back to FMAP start (did something corrupt this file?)\n",
SECTION_NAME_FMAP);
partitioned_file_close(file);
return NULL;
}
return file;
}
/* brute force linear search */
static long int fmap_lsearch(const uint8_t *image, size_t len)
{
unsigned long int offset;
int fmap_found = 0;
for (offset = 0; offset < len - strlen(FMAP_SIGNATURE); offset++) {
if (is_valid_fmap((const struct fmap *)&image[offset])) {
fmap_found = 1;
break;
}
}
if (!fmap_found)
return -1;
if (offset + fmap_size((const struct fmap *)&image[offset]) > len)
return -1;
return offset;
}
/* brute force linear search */
static long int fmap_lsearch(const uint8_t *image, size_t len)
{
long int offset;
int fmap_found = 0;
for (offset = 0; offset < len - strlen(FMAP_SIGNATURE); offset++) {
if (!memcmp(&image[offset],
FMAP_SIGNATURE,
strlen(FMAP_SIGNATURE))) {
fmap_found = 1;
break;
}
}
if (!fmap_found)
return -1;
if (offset + fmap_size((struct fmap *)&image[offset]) > len)
return -1;
return offset;
}
/* if image length is a power of 2, use binary search */
static long int fmap_bsearch(const uint8_t *image, size_t len)
{
long int offset = -1;
int fmap_found = 0, stride;
/*
* For efficient operation, we start with the largest stride possible
* and then decrease the stride on each iteration. Also, check for a
* remainder when modding the offset with the previous stride. This
* makes it so that each offset is only checked once.
*/
for (stride = len / 2; stride >= 1; stride /= 2) {
if (fmap_found)
break;
for (offset = 0;
offset < len - strlen(FMAP_SIGNATURE);
offset += stride) {
if ((offset % (stride * 2) == 0) && (offset != 0))
continue;
if (!memcmp(&image[offset],
FMAP_SIGNATURE,
strlen(FMAP_SIGNATURE))) {
fmap_found = 1;
break;
}
}
}
if (!fmap_found)
return -1;
if (offset + fmap_size((struct fmap *)&image[offset]) > len)
return -1;
return offset;
}
static int fmap_get_csum_test(struct fmap *fmap)
{
uint8_t *digest = NULL, *image = NULL;
/* assume 0x100-0x10100 is marked "static" and is filled with 0x00 */
int image_size = 0x20000;
uint8_t csum[SHA_DIGEST_SIZE] = {
0x1a, 0xdc, 0x95, 0xbe, 0xbe, 0x9e, 0xea, 0x8c,
0x11, 0x2d, 0x40, 0xcd, 0x04, 0xab, 0x7a, 0x8d,
0x75, 0xc4, 0xf9, 0x61 };
status = fail;
if ((fmap_get_csum(NULL, image_size, &digest) >= 0) ||
(fmap_get_csum(image, image_size, NULL) >= 0)) {
printf("failed to abort on NULL pointer input\n");
goto fmap_get_csum_test_exit;
}
image = calloc(image_size, 1);
memcpy(image, fmap, fmap_size(fmap));
if (fmap_get_csum(image, image_size, &digest) != SHA_DIGEST_SIZE) {
printf("FAILURE: failed to calculate checksum\n");
goto fmap_get_csum_test_exit;
}
if (memcmp(digest, csum, SHA_DIGEST_SIZE)) {
printf("FAILURE: checksum is incorrect\n");
goto fmap_get_csum_test_exit;
}
status = pass;
fmap_get_csum_test_exit:
free(image);
free(digest);
return status;
}
static int fmap_find_test(struct fmap *fmap)
{
uint8_t *buf;
size_t total_size, offset;
status = fail;
/*
* Note: In these tests, we'll use fmap_find() and control usage of
* lsearch and bsearch by using a power-of-2 total_size. For lsearch,
* use total_size - 1. For bsearch, use total_size.
*/
total_size = 0x100000;
buf = calloc(total_size, 1);
/* test if image length is zero */
if (fmap_find(buf, 0) >= 0) {
printf("FAILURE: failed to abort on zero-length image\n");
goto fmap_find_test_exit;
}
/* test if no fmap exists */
if (fmap_find(buf, total_size - 1) >= 0) {
printf("FAILURE: lsearch returned false positive\n");
goto fmap_find_test_exit;
}
if (fmap_find(buf, total_size) >= 0) {
printf("FAILURE: bsearch returned false positive\n");
goto fmap_find_test_exit;
}
/* simple test case: fmap at (total_size / 2) + 1 */
offset = (total_size / 2) + 1;
memcpy(&buf[offset], fmap, fmap_size(fmap));
if ((unsigned)fmap_find(buf, total_size - 1) != offset) {
printf("FAILURE: lsearch failed to find fmap\n");
goto fmap_find_test_exit;
}
if ((unsigned)fmap_find(buf, total_size) != offset) {
printf("FAILURE: bsearch failed to find fmap\n");
goto fmap_find_test_exit;
}
/* test bsearch if offset is at 0 */
offset = 0;
memset(buf, 0, total_size);
memcpy(buf, fmap, fmap_size(fmap));
if ((unsigned)fmap_find(buf, total_size) != offset) {
printf("FAILURE: bsearch failed to find fmap at offset 0\n");
goto fmap_find_test_exit;
}
/* test overrun detection */
memset(buf, 0, total_size);
memcpy(&buf[total_size - fmap_size(fmap) + 1],
fmap,
fmap_size(fmap) + 1);
if (fmap_find(buf, total_size - 1) >= 0) {
printf("FAILURE: lsearch failed to catch overrun\n");
goto fmap_find_test_exit;
}
if (fmap_find(buf, total_size) >= 0) {
printf("FAILURE: bsearch failed to catch overrun\n");
goto fmap_find_test_exit;
}
status = pass;
fmap_find_test_exit:
free(buf);
return status;
}
