libpayload: Add a function to verify the checksum on a LAR file

This function verifies the checksum on a LAR file.

Signed-off-by: Jordan Crouse <jordan.crouse@amd.com>
Acked-by: Peter Stuge <peter@stuge.se>


git-svn-id: svn://svn.coreboot.org/coreboot/trunk@3352 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
This commit is contained in:
Jordan Crouse 2008-05-27 19:57:53 +00:00
parent 02a4e7f6f8
commit 9e734c29cf
2 changed files with 36 additions and 0 deletions

View File

@ -251,6 +251,7 @@ struct larent *readlar(struct LAR *lar);
void rewindlar(struct LAR *lar);
int larstat(struct LAR *lar, const char *path, struct larstat *buf);
void *larfptr(struct LAR *lar, const char *filename);
int lfverify(struct LAR *lar, const char *filename);
struct LFILE * lfopen(struct LAR *lar, const char *filename);
int lfread(void *ptr, size_t size, size_t nmemb, struct LFILE *stream);

View File

@ -228,6 +228,41 @@ void * larfptr(struct LAR *lar, const char *filename)
return (void *) ((u8 *) header + ntohl(header->offset));
}
/**
* Verify the checksum on a particular LAR entry
*
* @param lar A pointer to the LAR stream
* @param filename The lar entry to verify
* @return Return 1 if the entry is valid, 0 if it is not, or -1
* on error
*/
int lfverify(struct LAR *lar, const char *filename)
{
struct lar_header *header = get_header_by_name(lar, filename);
u8 *ptr = (u8 *) header;
int len = ntohl(header->len) + ntohl(header->offset);
int offset;
u32 csum = 0;
if (header == NULL)
return -1;
/* The checksum needs to be calulated on entire data section,
* including any padding for the 16 byte alignment (which should
* be zeros
*/
len = (len + 15) & 0xFFFFFFF0;
for(offset = 0; offset < len; offset += 4) {
csum += *((u32 *) (ptr + offset));
}
return (csum == 0xFFFFFFFF) ? 1 : 0;
}
struct LFILE * lfopen(struct LAR *lar, const char *filename)
{
struct LFILE *file;