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1/* TODO: csum_tcpudp_magic could be speeded up, and csum_fold as well */
2
3#ifndef _CRIS_CHECKSUM_H
4#define _CRIS_CHECKSUM_H
5
6#include <asm/arch/checksum.h>
7
8/*
9 * computes the checksum of a memory block at buff, length len,
10 * and adds in "sum" (32-bit)
11 *
12 * returns a 32-bit number suitable for feeding into itself
13 * or csum_tcpudp_magic
14 *
15 * this function must be called with even lengths, except
16 * for the last fragment, which may be odd
17 *
18 * it's best to have buff aligned on a 32-bit boundary
19 */
20unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum);
21
22/*
23 * the same as csum_partial, but copies from src while it
24 * checksums
25 *
26 * here even more important to align src and dst on a 32-bit (or even
27 * better 64-bit) boundary
28 */
29
30unsigned int csum_partial_copy_nocheck(const char *src, char *dst,
31 int len, unsigned int sum);
32
33/*
34 * Fold a partial checksum into a word
35 */
36
37static inline unsigned int csum_fold(unsigned int sum)
38{
39 /* the while loop is unnecessary really, it's always enough with two
40 iterations */
41
42 while(sum >> 16)
43 sum = (sum & 0xffff) + (sum >> 16); /* add in end-around carry */
44
45 return ~sum;
46}
47
48extern unsigned int csum_partial_copy_from_user(const char *src, char *dst,
49 int len, unsigned int sum,
50 int *errptr);
51
52/*
53 * This is a version of ip_compute_csum() optimized for IP headers,
54 * which always checksum on 4 octet boundaries.
55 *
56 */
57
58static inline unsigned short ip_fast_csum(unsigned char * iph,
59 unsigned int ihl)
60{
61 return csum_fold(csum_partial(iph, ihl * 4, 0));
62}
63
64/*
65 * computes the checksum of the TCP/UDP pseudo-header
66 * returns a 16-bit checksum, already complemented
67 */
68
69static inline unsigned short int csum_tcpudp_magic(unsigned long saddr,
70 unsigned long daddr,
71 unsigned short len,
72 unsigned short proto,
73 unsigned int sum)
74{
75 return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
76}
77
78/*
79 * this routine is used for miscellaneous IP-like checksums, mainly
80 * in icmp.c
81 */
82
83static inline unsigned short ip_compute_csum(unsigned char * buff, int len) {
84 return csum_fold (csum_partial(buff, len, 0));
85}
86
87#endif