diff options
author | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2009-07-23 00:47:29 -0400 |
---|---|---|
committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2009-07-23 00:47:29 -0400 |
commit | bd072111e7319d90a7b8127f91c2806b9a6f279e (patch) | |
tree | 1686978814a2387ebfc16f9f5778a7f0caaf319b /include/asm-generic/checksum.h | |
parent | 24d01c0681bfbc10a99304c48a89ad213d2d7a4b (diff) | |
parent | 4be3bd7849165e7efa6b0b35a23d6a3598d97465 (diff) |
Merge commit 'v2.6.31-rc4' into next
Diffstat (limited to 'include/asm-generic/checksum.h')
-rw-r--r-- | include/asm-generic/checksum.h | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/include/asm-generic/checksum.h b/include/asm-generic/checksum.h new file mode 100644 index 000000000000..4647c762d970 --- /dev/null +++ b/include/asm-generic/checksum.h | |||
@@ -0,0 +1,79 @@ | |||
1 | #ifndef __ASM_GENERIC_CHECKSUM_H | ||
2 | #define __ASM_GENERIC_CHECKSUM_H | ||
3 | |||
4 | /* | ||
5 | * computes the checksum of a memory block at buff, length len, | ||
6 | * and adds in "sum" (32-bit) | ||
7 | * | ||
8 | * returns a 32-bit number suitable for feeding into itself | ||
9 | * or csum_tcpudp_magic | ||
10 | * | ||
11 | * this function must be called with even lengths, except | ||
12 | * for the last fragment, which may be odd | ||
13 | * | ||
14 | * it's best to have buff aligned on a 32-bit boundary | ||
15 | */ | ||
16 | extern __wsum csum_partial(const void *buff, int len, __wsum sum); | ||
17 | |||
18 | /* | ||
19 | * the same as csum_partial, but copies from src while it | ||
20 | * checksums | ||
21 | * | ||
22 | * here even more important to align src and dst on a 32-bit (or even | ||
23 | * better 64-bit) boundary | ||
24 | */ | ||
25 | extern __wsum csum_partial_copy(const void *src, void *dst, int len, __wsum sum); | ||
26 | |||
27 | /* | ||
28 | * the same as csum_partial_copy, but copies from user space. | ||
29 | * | ||
30 | * here even more important to align src and dst on a 32-bit (or even | ||
31 | * better 64-bit) boundary | ||
32 | */ | ||
33 | extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst, | ||
34 | int len, __wsum sum, int *csum_err); | ||
35 | |||
36 | #define csum_partial_copy_nocheck(src, dst, len, sum) \ | ||
37 | csum_partial_copy((src), (dst), (len), (sum)) | ||
38 | |||
39 | /* | ||
40 | * This is a version of ip_compute_csum() optimized for IP headers, | ||
41 | * which always checksum on 4 octet boundaries. | ||
42 | */ | ||
43 | extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl); | ||
44 | |||
45 | /* | ||
46 | * Fold a partial checksum | ||
47 | */ | ||
48 | static inline __sum16 csum_fold(__wsum csum) | ||
49 | { | ||
50 | u32 sum = (__force u32)csum; | ||
51 | sum = (sum & 0xffff) + (sum >> 16); | ||
52 | sum = (sum & 0xffff) + (sum >> 16); | ||
53 | return (__force __sum16)~sum; | ||
54 | } | ||
55 | |||
56 | #ifndef csum_tcpudp_nofold | ||
57 | /* | ||
58 | * computes the checksum of the TCP/UDP pseudo-header | ||
59 | * returns a 16-bit checksum, already complemented | ||
60 | */ | ||
61 | extern __wsum | ||
62 | csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len, | ||
63 | unsigned short proto, __wsum sum); | ||
64 | #endif | ||
65 | |||
66 | static inline __sum16 | ||
67 | csum_tcpudp_magic(__be32 saddr, __be32 daddr, unsigned short len, | ||
68 | unsigned short proto, __wsum sum) | ||
69 | { | ||
70 | return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); | ||
71 | } | ||
72 | |||
73 | /* | ||
74 | * this routine is used for miscellaneous IP-like checksums, mainly | ||
75 | * in icmp.c | ||
76 | */ | ||
77 | extern __sum16 ip_compute_csum(const void *buff, int len); | ||
78 | |||
79 | #endif /* __ASM_GENERIC_CHECKSUM_H */ | ||