blob: 56c0f6056f165f1020940de239d096ca2ee69a07 [file] [log] [blame]
#include <sys/types.h>
#include <stdio.h>
#include <errno.h>
#include <sys/acl.h>
#include "reiserfs_lib.h"
static inline unsigned short from32to16(unsigned int x)
{
/* add up 16-bit and 16-bit for 16+c bit */
x = (x & 0xffff) + (x >> 16);
/* add up carry.. */
x = (x & 0xffff) + (x >> 16);
return x;
}
static unsigned int do_csum(const unsigned char *buff, int len)
{
int odd;
unsigned int result = 0;
if (len <= 0)
goto out;
odd = 1 & (unsigned long) buff;
if (odd) {
#ifdef __LITTLE_ENDIAN
result += (*buff << 8);
#else
result = *buff;
#endif
len--;
buff++;
}
if (len >= 2) {
if (2 & (unsigned long) buff) {
result += *(unsigned short *) buff;
len -= 2;
buff += 2;
}
if (len >= 4) {
const unsigned char *end = buff + ((unsigned)len & ~3);
unsigned int carry = 0;
do {
unsigned int w = *(unsigned int *) buff;
buff += 4;
result += carry;
result += w;
carry = (w > result);
} while (buff < end);
result += carry;
result = (result & 0xffff) + (result >> 16);
}
if (len & 2) {
result += *(unsigned short *) buff;
buff += 2;
}
}
if (len & 1)
#ifdef __LITTLE_ENDIAN
result += *buff;
#else
result += (*buff << 8);
#endif
result = from32to16(result);
if (odd)
result = ((result >> 8) & 0xff) | ((result & 0xff) << 8);
out:
return result;
}
__wsum csum_partial(const void *buff, int len, __wsum wsum)
{
unsigned int sum = (__force unsigned int)wsum;
unsigned int result = do_csum(buff, len);
/* add in old sum, and carry.. */
result += sum;
if (sum > result)
result += 1;
return (__force __wsum)result;
}
inline __u32 reiserfs_xattr_hash(const char *msg, int len)
{
return csum_partial(msg, len, 0);
}
int reiserfs_check_xattr(const void *body, int len)
{
const struct reiserfs_xattr_header *xah = body;
int hdrsz = sizeof(struct reiserfs_xattr_header);
__u32 hash, disk_hash;
if (len < hdrsz)
return -EINVAL;
hash = reiserfs_xattr_hash(body + hdrsz, len - hdrsz);
disk_hash = le32_to_cpu(xah->h_hash);
return xah->h_magic == cpu_to_le32(REISERFS_XATTR_MAGIC) &&
(disk_hash == hash || from32to16(disk_hash) == hash);
}
int reiserfs_acl_count(size_t size)
{
ssize_t s;
size -= sizeof(struct reiserfs_acl_header);
s = size - 4 * sizeof(struct reiserfs_acl_entry_short);
if (s < 0) {
if (size % sizeof(struct reiserfs_acl_entry_short))
return -1;
return size / sizeof(struct reiserfs_acl_entry_short);
} else {
if (s % sizeof(struct reiserfs_acl_entry))
return -1;
return s / sizeof(struct reiserfs_acl_entry) + 4;
}
}