diff options
Diffstat (limited to 'payloads/libpayload/libcbfs/cbfs_core.c')
| -rw-r--r-- | payloads/libpayload/libcbfs/cbfs_core.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/payloads/libpayload/libcbfs/cbfs_core.c b/payloads/libpayload/libcbfs/cbfs_core.c index 7926d9d650..6a19b269c1 100644 --- a/payloads/libpayload/libcbfs/cbfs_core.c +++ b/payloads/libpayload/libcbfs/cbfs_core.c @@ -213,6 +213,47 @@ void *cbfs_get_file_content(struct cbfs_media *media, const char *name, return (void *)CBFS_SUBHEADER(file); } +struct cbfs_file_attribute *cbfs_file_first_attr(struct cbfs_file *file) +{ + /* attributes_offset should be 0 when there is no attribute, but all + * values that point into the cbfs_file header are invalid, too. */ + if (ntohl(file->attributes_offset) <= sizeof(*file)) + return NULL; + + /* There needs to be enough space for the file header and one + * attribute header for this to make sense. */ + if (ntohl(file->offset) <= + sizeof(*file) + sizeof(struct cbfs_file_attribute)) + return NULL; + + return (struct cbfs_file_attribute *) + (((uint8_t *)file) + ntohl(file->attributes_offset)); +} + +struct cbfs_file_attribute *cbfs_file_next_attr(struct cbfs_file *file, + struct cbfs_file_attribute *attr) +{ + /* ex falso sequitur quodlibet */ + if (attr == NULL) + return NULL; + + /* Is there enough space for another attribute? */ + if ((uint8_t *)attr + ntohl(attr->len) + + sizeof(struct cbfs_file_attribute) >= + (uint8_t *)file + ntohl(file->offset)) + return NULL; + + struct cbfs_file_attribute *next = (struct cbfs_file_attribute *) + (((uint8_t *)attr) + ntohl(attr->len)); + /* If any, "unused" attributes must come last. */ + if (ntohl(next->tag) == CBFS_FILE_ATTR_TAG_UNUSED) + return NULL; + if (ntohl(next->tag) == CBFS_FILE_ATTR_TAG_UNUSED2) + return NULL; + + return next; +} + int cbfs_decompress(int algo, void *src, void *dst, int len) { switch (algo) { |