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Diffstat (limited to 'util/cbfstool/cbfs_image.c')
-rw-r--r--util/cbfstool/cbfs_image.c40
1 files changed, 29 insertions, 11 deletions
diff --git a/util/cbfstool/cbfs_image.c b/util/cbfstool/cbfs_image.c
index 0230d8032..621a35d16 100644
--- a/util/cbfstool/cbfs_image.c
+++ b/util/cbfstool/cbfs_image.c
@@ -267,7 +267,8 @@ int cbfs_image_create(struct cbfs_image *image,
return 0;
}
-int cbfs_image_from_file(struct cbfs_image *image, const char *filename)
+int cbfs_image_from_file(struct cbfs_image *image,
+ const char *filename, uint32_t offset)
{
void *header_loc;
@@ -275,7 +276,9 @@ int cbfs_image_from_file(struct cbfs_image *image, const char *filename)
return -1;
DEBUG("read_cbfs_image: %s (%zd bytes)\n", image->buffer.name,
image->buffer.size);
- header_loc = cbfs_find_header(image->buffer.data, image->buffer.size);
+ header_loc = cbfs_find_header(image->buffer.data,
+ image->buffer.size,
+ offset);
if (!header_loc) {
ERROR("%s does not have CBFS master header.\n", filename);
cbfs_image_delete(image);
@@ -767,21 +770,41 @@ int cbfs_walk(struct cbfs_image *image, cbfs_entry_callback callback,
return count;
}
-struct cbfs_header *cbfs_find_header(char *data, size_t size)
+static int cbfs_header_valid(struct cbfs_header *header, size_t size)
+{
+ if ((ntohl(header->magic) == CBFS_HEADER_MAGIC) &&
+ ((ntohl(header->version) == CBFS_HEADER_VERSION1) ||
+ (ntohl(header->version) == CBFS_HEADER_VERSION2)) &&
+ (ntohl(header->romsize) <= size) &&
+ (ntohl(header->offset) < ntohl(header->romsize)))
+ return 1;
+ return 0;
+}
+
+struct cbfs_header *cbfs_find_header(char *data, size_t size,
+ uint32_t forced_offset)
{
size_t offset;
int found = 0;
int32_t rel_offset;
struct cbfs_header *header, *result = NULL;
+ if (forced_offset < (size - sizeof(struct cbfs_header))) {
+ /* Check if the forced header is valid. */
+ header = (struct cbfs_header *)(data + forced_offset);
+ if (cbfs_header_valid(header, size))
+ return header;
+ return NULL;
+ }
+
// Try finding relative offset of master header at end of file first.
rel_offset = *(int32_t *)(data + size - sizeof(int32_t));
offset = size + rel_offset;
DEBUG("relative offset: %#zx(-%#zx), offset: %#zx\n",
(size_t)rel_offset, (size_t)-rel_offset, offset);
+
if (offset >= size - sizeof(*header) ||
- ntohl(((struct cbfs_header *)(data + offset))->magic) !=
- CBFS_HEADER_MAGIC) {
+ !cbfs_header_valid((struct cbfs_header *)(data + offset), size)) {
// Some use cases append non-CBFS data to the end of the ROM.
DEBUG("relative offset seems wrong, scanning whole image...\n");
offset = 0;
@@ -789,13 +812,8 @@ struct cbfs_header *cbfs_find_header(char *data, size_t size)
for (; offset + sizeof(*header) < size; offset++) {
header = (struct cbfs_header *)(data + offset);
- if (ntohl(header->magic) !=(CBFS_HEADER_MAGIC))
- continue;
- if (ntohl(header->version) != CBFS_HEADER_VERSION1 &&
- ntohl(header->version) != CBFS_HEADER_VERSION2) {
- // Probably not a real CBFS header?
+ if (!cbfs_header_valid(header, size))
continue;
- }
if (!found++)
result = header;
}