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checksum.h
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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  */
10 extern __sum16 ip_fast_csum(const void *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  */
17  unsigned short len,
18  unsigned short proto,
19  __wsum sum);
20 
22  unsigned short len, unsigned short proto,
23  __wsum sum);
24 
25 /*
26  * computes the checksum of a memory block at buff, length len,
27  * and adds in "sum" (32-bit)
28  *
29  * returns a 32-bit number suitable for feeding into itself
30  * or csum_tcpudp_magic
31  *
32  * this function must be called with even lengths, except
33  * for the last fragment, which may be odd
34  *
35  * it's best to have buff aligned on a 32-bit boundary
36  */
37 extern __wsum csum_partial(const void *buff, int len, __wsum sum);
38 
39 /*
40  * the same as csum_partial, but copies from src while it
41  * checksums
42  *
43  * here even more important to align src and dst on a 32-bit (or even
44  * better 64-bit) boundary
45  */
46 __wsum csum_partial_copy_from_user(const void __user *src, void *dst, int len, __wsum sum, int *errp);
47 
48 __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum);
49 
50 
51 /*
52  * this routine is used for miscellaneous IP-like checksums, mainly
53  * in icmp.c
54  */
55 
56 extern __sum16 ip_compute_csum(const void *buff, int len);
57 
58 /*
59  * Fold a partial checksum without adding pseudo headers
60  */
61 
62 static inline __sum16 csum_fold(__wsum csum)
63 {
64  u32 sum = (__force u32)csum;
65  sum = (sum & 0xffff) + (sum >> 16);
66  sum = (sum & 0xffff) + (sum >> 16);
67  return (__force __sum16)~sum;
68 }
69 
70 #define _HAVE_ARCH_IPV6_CSUM
71 extern __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
72  const struct in6_addr *daddr,
73  __u32 len, unsigned short proto,
74  __wsum sum);
75 #endif