diff options
Diffstat (limited to 'include/net/checksum.h')
-rw-r--r-- | include/net/checksum.h | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/include/net/checksum.h b/include/net/checksum.h new file mode 100644 index 000000000000..e3ea7cc2c728 --- /dev/null +++ b/include/net/checksum.h | |||
@@ -0,0 +1,87 @@ | |||
1 | /* | ||
2 | * INET An implementation of the TCP/IP protocol suite for the LINUX | ||
3 | * operating system. INET is implemented using the BSD Socket | ||
4 | * interface as the means of communication with the user level. | ||
5 | * | ||
6 | * Checksumming functions for IP, TCP, UDP and so on | ||
7 | * | ||
8 | * Authors: Jorge Cwik, <jorge@laser.satlink.net> | ||
9 | * Arnt Gulbrandsen, <agulbra@nvg.unit.no> | ||
10 | * Borrows very liberally from tcp.c and ip.c, see those | ||
11 | * files for more names. | ||
12 | * | ||
13 | * This program is free software; you can redistribute it and/or | ||
14 | * modify it under the terms of the GNU General Public License | ||
15 | * as published by the Free Software Foundation; either version | ||
16 | * 2 of the License, or (at your option) any later version. | ||
17 | */ | ||
18 | |||
19 | #ifndef _CHECKSUM_H | ||
20 | #define _CHECKSUM_H | ||
21 | |||
22 | #include <linux/errno.h> | ||
23 | #include <asm/types.h> | ||
24 | #include <asm/byteorder.h> | ||
25 | #include <asm/uaccess.h> | ||
26 | #include <asm/checksum.h> | ||
27 | |||
28 | #ifndef _HAVE_ARCH_COPY_AND_CSUM_FROM_USER | ||
29 | static inline | ||
30 | unsigned int csum_and_copy_from_user (const unsigned char __user *src, unsigned char *dst, | ||
31 | int len, int sum, int *err_ptr) | ||
32 | { | ||
33 | if (access_ok(VERIFY_READ, src, len)) | ||
34 | return csum_partial_copy_from_user(src, dst, len, sum, err_ptr); | ||
35 | |||
36 | if (len) | ||
37 | *err_ptr = -EFAULT; | ||
38 | |||
39 | return sum; | ||
40 | } | ||
41 | #endif | ||
42 | |||
43 | #ifndef HAVE_CSUM_COPY_USER | ||
44 | static __inline__ unsigned int csum_and_copy_to_user | ||
45 | (const unsigned char *src, unsigned char __user *dst, int len, unsigned int sum, int *err_ptr) | ||
46 | { | ||
47 | sum = csum_partial(src, len, sum); | ||
48 | |||
49 | if (access_ok(VERIFY_WRITE, dst, len)) { | ||
50 | if (copy_to_user(dst, src, len) == 0) | ||
51 | return sum; | ||
52 | } | ||
53 | if (len) | ||
54 | *err_ptr = -EFAULT; | ||
55 | |||
56 | return -1; /* invalid checksum */ | ||
57 | } | ||
58 | #endif | ||
59 | |||
60 | static inline unsigned int csum_add(unsigned int csum, unsigned int addend) | ||
61 | { | ||
62 | csum += addend; | ||
63 | return csum + (csum < addend); | ||
64 | } | ||
65 | |||
66 | static inline unsigned int csum_sub(unsigned int csum, unsigned int addend) | ||
67 | { | ||
68 | return csum_add(csum, ~addend); | ||
69 | } | ||
70 | |||
71 | static inline unsigned int | ||
72 | csum_block_add(unsigned int csum, unsigned int csum2, int offset) | ||
73 | { | ||
74 | if (offset&1) | ||
75 | csum2 = ((csum2&0xFF00FF)<<8)+((csum2>>8)&0xFF00FF); | ||
76 | return csum_add(csum, csum2); | ||
77 | } | ||
78 | |||
79 | static inline unsigned int | ||
80 | csum_block_sub(unsigned int csum, unsigned int csum2, int offset) | ||
81 | { | ||
82 | if (offset&1) | ||
83 | csum2 = ((csum2&0xFF00FF)<<8)+((csum2>>8)&0xFF00FF); | ||
84 | return csum_sub(csum, csum2); | ||
85 | } | ||
86 | |||
87 | #endif | ||