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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _ASM_IA64_CHECKSUM_H
2#define _ASM_IA64_CHECKSUM_H
3
4/*
5 * Modified 1998, 1999
6 * David Mosberger-Tang <davidm@hpl.hp.com>, Hewlett-Packard Co
7 */
8
9/*
10 * This is a version of ip_compute_csum() optimized for IP headers,
11 * which always checksum on 4 octet boundaries.
12 */
13extern unsigned short ip_fast_csum (unsigned char * iph, unsigned int ihl);
14
15/*
16 * Computes the checksum of the TCP/UDP pseudo-header returns a 16-bit
17 * checksum, already complemented
18 */
19extern unsigned short int csum_tcpudp_magic (unsigned long saddr,
20 unsigned long daddr,
21 unsigned short len,
22 unsigned short proto,
23 unsigned int sum);
24
25extern unsigned int csum_tcpudp_nofold (unsigned long saddr,
26 unsigned long daddr,
27 unsigned short len,
28 unsigned short proto,
29 unsigned int sum);
30
31/*
32 * Computes the checksum of a memory block at buff, length len,
33 * and adds in "sum" (32-bit)
34 *
35 * returns a 32-bit number suitable for feeding into itself
36 * or csum_tcpudp_magic
37 *
38 * this function must be called with even lengths, except
39 * for the last fragment, which may be odd
40 *
41 * it's best to have buff aligned on a 32-bit boundary
42 */
43extern unsigned int csum_partial (const unsigned char * buff, int len,
44 unsigned int sum);
45
46/*
47 * Same as csum_partial, but copies from src while it checksums.
48 *
49 * Here it is even more important to align src and dst on a 32-bit (or
50 * even better 64-bit) boundary.
51 */
52extern unsigned int csum_partial_copy_from_user (const char *src, char *dst,
53 int len, unsigned int sum,
54 int *errp);
55
56extern unsigned int csum_partial_copy_nocheck (const char *src, char *dst,
57 int len, unsigned int sum);
58
59/*
60 * This routine is used for miscellaneous IP-like checksums, mainly in
61 * icmp.c
62 */
63extern unsigned short ip_compute_csum (unsigned char *buff, int len);
64
65/*
66 * Fold a partial checksum without adding pseudo headers.
67 */
68static inline unsigned short
69csum_fold (unsigned int sum)
70{
71 sum = (sum & 0xffff) + (sum >> 16);
72 sum = (sum & 0xffff) + (sum >> 16);
73 return ~sum;
74}
75
76#endif /* _ASM_IA64_CHECKSUM_H */