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 /arch/ia64/lib/checksum.c |
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 'arch/ia64/lib/checksum.c')
-rw-r--r-- | arch/ia64/lib/checksum.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/arch/ia64/lib/checksum.c b/arch/ia64/lib/checksum.c new file mode 100644 index 000000000000..beb11721d9f5 --- /dev/null +++ b/arch/ia64/lib/checksum.c | |||
@@ -0,0 +1,102 @@ | |||
1 | /* | ||
2 | * Network checksum routines | ||
3 | * | ||
4 | * Copyright (C) 1999, 2003 Hewlett-Packard Co | ||
5 | * Stephane Eranian <eranian@hpl.hp.com> | ||
6 | * | ||
7 | * Most of the code coming from arch/alpha/lib/checksum.c | ||
8 | * | ||
9 | * This file contains network checksum routines that are better done | ||
10 | * in an architecture-specific manner due to speed.. | ||
11 | */ | ||
12 | |||
13 | #include <linux/module.h> | ||
14 | #include <linux/string.h> | ||
15 | |||
16 | #include <asm/byteorder.h> | ||
17 | |||
18 | static inline unsigned short | ||
19 | from64to16 (unsigned long x) | ||
20 | { | ||
21 | /* add up 32-bit words for 33 bits */ | ||
22 | x = (x & 0xffffffff) + (x >> 32); | ||
23 | /* add up 16-bit and 17-bit words for 17+c bits */ | ||
24 | x = (x & 0xffff) + (x >> 16); | ||
25 | /* add up 16-bit and 2-bit for 16+c bit */ | ||
26 | x = (x & 0xffff) + (x >> 16); | ||
27 | /* add up carry.. */ | ||
28 | x = (x & 0xffff) + (x >> 16); | ||
29 | return x; | ||
30 | } | ||
31 | |||
32 | /* | ||
33 | * computes the checksum of the TCP/UDP pseudo-header | ||
34 | * returns a 16-bit checksum, already complemented. | ||
35 | */ | ||
36 | unsigned short int | ||
37 | csum_tcpudp_magic (unsigned long saddr, unsigned long daddr, unsigned short len, | ||
38 | unsigned short proto, unsigned int sum) | ||
39 | { | ||
40 | return ~from64to16(saddr + daddr + sum + ((unsigned long) ntohs(len) << 16) + | ||
41 | ((unsigned long) proto << 8)); | ||
42 | } | ||
43 | |||
44 | EXPORT_SYMBOL(csum_tcpudp_magic); | ||
45 | |||
46 | unsigned int | ||
47 | csum_tcpudp_nofold (unsigned long saddr, unsigned long daddr, unsigned short len, | ||
48 | unsigned short proto, unsigned int sum) | ||
49 | { | ||
50 | unsigned long result; | ||
51 | |||
52 | result = (saddr + daddr + sum + | ||
53 | ((unsigned long) ntohs(len) << 16) + | ||
54 | ((unsigned long) proto << 8)); | ||
55 | |||
56 | /* Fold down to 32-bits so we don't lose in the typedef-less network stack. */ | ||
57 | /* 64 to 33 */ | ||
58 | result = (result & 0xffffffff) + (result >> 32); | ||
59 | /* 33 to 32 */ | ||
60 | result = (result & 0xffffffff) + (result >> 32); | ||
61 | return result; | ||
62 | } | ||
63 | |||
64 | extern unsigned long do_csum (const unsigned char *, long); | ||
65 | |||
66 | /* | ||
67 | * computes the checksum of a memory block at buff, length len, | ||
68 | * and adds in "sum" (32-bit) | ||
69 | * | ||
70 | * returns a 32-bit number suitable for feeding into itself | ||
71 | * or csum_tcpudp_magic | ||
72 | * | ||
73 | * this function must be called with even lengths, except | ||
74 | * for the last fragment, which may be odd | ||
75 | * | ||
76 | * it's best to have buff aligned on a 32-bit boundary | ||
77 | */ | ||
78 | unsigned int | ||
79 | csum_partial (const unsigned char * buff, int len, unsigned int sum) | ||
80 | { | ||
81 | unsigned long result = do_csum(buff, len); | ||
82 | |||
83 | /* add in old sum, and carry.. */ | ||
84 | result += sum; | ||
85 | /* 32+c bits -> 32 bits */ | ||
86 | result = (result & 0xffffffff) + (result >> 32); | ||
87 | return result; | ||
88 | } | ||
89 | |||
90 | EXPORT_SYMBOL(csum_partial); | ||
91 | |||
92 | /* | ||
93 | * this routine is used for miscellaneous IP-like checksums, mainly | ||
94 | * in icmp.c | ||
95 | */ | ||
96 | unsigned short | ||
97 | ip_compute_csum (unsigned char * buff, int len) | ||
98 | { | ||
99 | return ~do_csum(buff,len); | ||
100 | } | ||
101 | |||
102 | EXPORT_SYMBOL(ip_compute_csum); | ||