[linux-2.6-block.git] / include / asm-generic / checksum.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_GENERIC_CHECKSUM_H
#define __ASM_GENERIC_CHECKSUM_H

#include <linux/bitops.h>

/*
 * computes the checksum of a memory block at buff, length len,
 * and adds in "sum" (32-bit)
 *
 * returns a 32-bit number suitable for feeding into itself
 * or csum_tcpudp_magic
 *
 * this function must be called with even lengths, except
 * for the last fragment, which may be odd
 *
 * it's best to have buff aligned on a 32-bit boundary
 */
extern __wsum csum_partial(const void *buff, int len, __wsum sum);

#ifndef ip_fast_csum
/*
 * This is a version of ip_compute_csum() optimized for IP headers,
 * which always checksum on 4 octet boundaries.
 */
extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
#endif

#ifndef csum_fold
/*
 * Fold a partial checksum
 */
static inline __sum16 csum_fold(__wsum csum)
{
	u32 sum = (__force u32)csum;
	return (__force __sum16)((~sum - ror32(sum, 16)) >> 16);
}
#endif

#ifndef csum_tcpudp_nofold
/*
 * computes the checksum of the TCP/UDP pseudo-header
 * returns a 16-bit checksum, already complemented
 */
extern __wsum
csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len,
		   __u8 proto, __wsum sum);
#endif

#ifndef csum_tcpudp_magic
static inline __sum16
csum_tcpudp_magic(__be32 saddr, __be32 daddr, __u32 len,
		  __u8 proto, __wsum sum)
{
	return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
}
#endif

/*
 * this routine is used for miscellaneous IP-like checksums, mainly
 * in icmp.c
 */
extern __sum16 ip_compute_csum(const void *buff, int len);

#endif /* __ASM_GENERIC_CHECKSUM_H */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
26a28fa4 AB	2	#ifndef __ASM_GENERIC_CHECKSUM_H
	3	#define __ASM_GENERIC_CHECKSUM_H
	4
1e7196fa CJ	5	#include <linux/bitops.h>
1e7196fa CJ	6
26a28fa4 AB	7	/*
	8	* computes the checksum of a memory block at buff, length len,
	9	* and adds in "sum" (32-bit)
	10	*
	11	* returns a 32-bit number suitable for feeding into itself
	12	* or csum_tcpudp_magic
	13	*
	14	* this function must be called with even lengths, except
	15	* for the last fragment, which may be odd
	16	*
	17	* it's best to have buff aligned on a 32-bit boundary
	18	*/
	19	extern __wsum csum_partial(const void *buff, int len, __wsum sum);
	20
64e69073	21	#ifndef ip_fast_csum
26a28fa4 AB	22	/*
	23	* This is a version of ip_compute_csum() optimized for IP headers,
	24	* which always checksum on 4 octet boundaries.
	25	*/
	26	extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
64e69073	27	#endif
26a28fa4	28
64e69073	29	#ifndef csum_fold
26a28fa4 AB	30	/*
	31	* Fold a partial checksum
	32	*/
	33	static inline __sum16 csum_fold(__wsum csum)
	34	{
	35	u32 sum = (__force u32)csum;
1e7196fa	36	return (__force __sum16)((~sum - ror32(sum, 16)) >> 16);
26a28fa4	37	}
64e69073	38	#endif
26a28fa4 AB	39
	40	#ifndef csum_tcpudp_nofold
	41	/*
	42	* computes the checksum of the TCP/UDP pseudo-header
	43	* returns a 16-bit checksum, already complemented
	44	*/
	45	extern __wsum
01cfbad7 AD	46	csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len,
01cfbad7 AD	47	__u8 proto, __wsum sum);
26a28fa4 AB	48	#endif
26a28fa4 AB	49
4e29198e	50	#ifndef csum_tcpudp_magic
26a28fa4	51	static inline __sum16
01cfbad7 AD	52	csum_tcpudp_magic(__be32 saddr, __be32 daddr, __u32 len,
01cfbad7 AD	53	__u8 proto, __wsum sum)
26a28fa4 AB	54	{
	55	return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
	56	}
4e29198e	57	#endif
26a28fa4 AB	58
	59	/*
	60	* this routine is used for miscellaneous IP-like checksums, mainly
	61	* in icmp.c
	62	*/
	63	extern __sum16 ip_compute_csum(const void *buff, int len);
	64
	65	#endif /* __ASM_GENERIC_CHECKSUM_H */