diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-cris/checksum.h |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'include/asm-cris/checksum.h')
-rw-r--r-- | include/asm-cris/checksum.h | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/include/asm-cris/checksum.h b/include/asm-cris/checksum.h new file mode 100644 index 000000000000..15ca8aec5c63 --- /dev/null +++ b/include/asm-cris/checksum.h | |||
@@ -0,0 +1,87 @@ | |||
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 | */ | ||
20 | unsigned 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 | |||
30 | unsigned 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 | |||
37 | extern 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 | |||
48 | extern 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 | |||
58 | extern 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 | |||
69 | extern 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 | |||
83 | extern inline unsigned short ip_compute_csum(unsigned char * buff, int len) { | ||
84 | return csum_fold (csum_partial(buff, len, 0)); | ||
85 | } | ||
86 | |||
87 | #endif | ||