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 */
16extern __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 */
25extern __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 */
33extern __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 */
43extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
 
44
 
45/*
46 * Fold a partial checksum
47 */
48static 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 */
61extern __wsum
62csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len,
63		unsigned short proto, __wsum sum);
64#endif
65
 
66static inline __sum16
67csum_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 */
77extern __sum16 ip_compute_csum(const void *buff, int len);
78
79#endif /* __ASM_GENERIC_CHECKSUM_H */

 1/* SPDX-License-Identifier: GPL-2.0 */
 2#ifndef __ASM_GENERIC_CHECKSUM_H
 3#define __ASM_GENERIC_CHECKSUM_H
 4
 5/*
 6 * computes the checksum of a memory block at buff, length len,
 7 * and adds in "sum" (32-bit)
 8 *
 9 * returns a 32-bit number suitable for feeding into itself
10 * or csum_tcpudp_magic
11 *
12 * this function must be called with even lengths, except
13 * for the last fragment, which may be odd
14 *
15 * it's best to have buff aligned on a 32-bit boundary
16 */
17extern __wsum csum_partial(const void *buff, int len, __wsum sum);
18
19/*
20 * the same as csum_partial, but copies from src while it
21 * checksums
22 *
23 * here even more important to align src and dst on a 32-bit (or even
24 * better 64-bit) boundary
25 */
26#ifndef csum_partial_copy_nocheck
27__wsum csum_partial_copy_nocheck(const void *src, void *dst, int len,
28		__wsum sum);
29#endif
 
 
 
 
 
 
 
 
 
30
31#ifndef ip_fast_csum
32/*
33 * This is a version of ip_compute_csum() optimized for IP headers,
34 * which always checksum on 4 octet boundaries.
35 */
36extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
37#endif
38
39#ifndef csum_fold
40/*
41 * Fold a partial checksum
42 */
43static inline __sum16 csum_fold(__wsum csum)
44{
45	u32 sum = (__force u32)csum;
46	sum = (sum & 0xffff) + (sum >> 16);
47	sum = (sum & 0xffff) + (sum >> 16);
48	return (__force __sum16)~sum;
49}
50#endif
51
52#ifndef csum_tcpudp_nofold
53/*
54 * computes the checksum of the TCP/UDP pseudo-header
55 * returns a 16-bit checksum, already complemented
56 */
57extern __wsum
58csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len,
59		   __u8 proto, __wsum sum);
60#endif
61
62#ifndef csum_tcpudp_magic
63static inline __sum16
64csum_tcpudp_magic(__be32 saddr, __be32 daddr, __u32 len,
65		  __u8 proto, __wsum sum)
66{
67	return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
68}
69#endif
70
71/*
72 * this routine is used for miscellaneous IP-like checksums, mainly
73 * in icmp.c
74 */
75extern __sum16 ip_compute_csum(const void *buff, int len);
76
77#endif /* __ASM_GENERIC_CHECKSUM_H */