git-commit-vandalism/delta.h
Nicolas Pitre 8960844a78 check patch_delta bounds more carefully
Let's avoid going south with invalid delta data.

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-07 16:31:20 -07:00

36 lines
955 B
C

#ifndef DELTA_H
#define DELTA_H
/* handling of delta buffers */
extern void *diff_delta(void *from_buf, unsigned long from_size,
void *to_buf, unsigned long to_size,
unsigned long *delta_size, unsigned long max_size);
extern void *patch_delta(void *src_buf, unsigned long src_size,
void *delta_buf, unsigned long delta_size,
unsigned long *dst_size);
/* the smallest possible delta size is 4 bytes */
#define DELTA_SIZE_MIN 4
/*
* This must be called twice on the delta data buffer, first to get the
* expected reference buffer size, and again to get the result buffer size.
*/
static inline unsigned long get_delta_hdr_size(const unsigned char **datap,
const unsigned char *top)
{
const unsigned char *data = *datap;
unsigned char cmd;
unsigned long size = 0;
int i = 0;
do {
cmd = *data++;
size |= (cmd & ~0x80) << i;
i += 7;
} while (cmd & 0x80 && data < top);
*datap = data;
return size;
}
#endif