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Linux kernel mirror (for testing)
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kernel
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linux
1#ifndef _ALPHA_CHECKSUM_H
2#define _ALPHA_CHECKSUM_H
3
4#include <linux/in6.h>
5
6/*
7 * This is a version of ip_compute_csum() optimized for IP headers,
8 * which always checksum on 4 octet boundaries.
9 */
10extern unsigned short ip_fast_csum(unsigned char * iph, unsigned int ihl);
11
12/*
13 * computes the checksum of the TCP/UDP pseudo-header
14 * returns a 16-bit checksum, already complemented
15 */
16extern unsigned short int csum_tcpudp_magic(unsigned long saddr,
17 unsigned long daddr,
18 unsigned short len,
19 unsigned short proto,
20 unsigned int sum);
21
22unsigned int csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr,
23 unsigned short len, unsigned short proto,
24 unsigned int sum);
25
26/*
27 * computes the checksum of a memory block at buff, length len,
28 * and adds in "sum" (32-bit)
29 *
30 * returns a 32-bit number suitable for feeding into itself
31 * or csum_tcpudp_magic
32 *
33 * this function must be called with even lengths, except
34 * for the last fragment, which may be odd
35 *
36 * it's best to have buff aligned on a 32-bit boundary
37 */
38extern unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum);
39
40/*
41 * the same as csum_partial, but copies from src while it
42 * checksums
43 *
44 * here even more important to align src and dst on a 32-bit (or even
45 * better 64-bit) boundary
46 */
47unsigned int csum_partial_copy_from_user(const char __user *src, char *dst, int len, unsigned int sum, int *errp);
48
49unsigned int csum_partial_copy_nocheck(const char *src, char *dst, int len, unsigned int sum);
50
51
52/*
53 * this routine is used for miscellaneous IP-like checksums, mainly
54 * in icmp.c
55 */
56
57extern unsigned short ip_compute_csum(unsigned char * buff, int len);
58
59/*
60 * Fold a partial checksum without adding pseudo headers
61 */
62
63static inline unsigned short csum_fold(unsigned int sum)
64{
65 sum = (sum & 0xffff) + (sum >> 16);
66 sum = (sum & 0xffff) + (sum >> 16);
67 return ~sum;
68}
69
70#define _HAVE_ARCH_IPV6_CSUM
71extern unsigned short int csum_ipv6_magic(struct in6_addr *saddr,
72 struct in6_addr *daddr,
73 __u32 len,
74 unsigned short proto,
75 unsigned int sum);
76
77#endif