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git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/blob - include/asm-x86_64/checksum.h
1 #ifndef _X86_64_CHECKSUM_H
2 #define _X86_64_CHECKSUM_H
6 * Copyright 2002 by Andi Kleen, SuSE Labs
7 * with some code from asm-i386/checksum.h
10 #include <linux/compiler.h>
11 #include <asm/uaccess.h>
12 #include <asm/byteorder.h>
15 * csum_fold - Fold and invert a 32bit checksum.
16 * sum: 32bit unfolded sum
18 * Fold a 32bit running checksum to 16bit and invert it. This is usually
19 * the last step before putting a checksum into a packet.
20 * Make sure not to mix with 64bit checksums.
22 static inline unsigned int csum_fold(unsigned int sum
)
28 : "r" (sum
<< 16), "0" (sum
& 0xffff0000)
34 * This is a version of ip_compute_csum() optimized for IP headers,
35 * which always checksum on 4 octet boundaries.
37 * By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by
42 * ip_fast_csum - Compute the IPv4 header checksum efficiently.
44 * ihl: length of header / 4
46 static inline unsigned short ip_fast_csum(unsigned char *iph
, unsigned int ihl
)
50 asm( " movl (%1), %0\n"
56 "1: adcl 16(%1), %0\n"
67 /* Since the input registers which are loaded with iph and ihl
68 are modified, we must also specify them as outputs, or gcc
69 will assume they contain their original values. */
70 : "=r" (sum
), "=r" (iph
), "=r" (ihl
)
71 : "1" (iph
), "2" (ihl
)
77 * csum_tcpup_nofold - Compute an IPv4 pseudo header checksum.
78 * @saddr: source address
79 * @daddr: destination address
80 * @len: length of packet
81 * @proto: ip protocol of packet
82 * @sum: initial sum to be added in (32bit unfolded)
84 * Returns the pseudo header checksum the input data. Result is
87 static inline unsigned long
88 csum_tcpudp_nofold(unsigned saddr
, unsigned daddr
, unsigned short len
,
89 unsigned short proto
, unsigned int sum
)
96 : "g" (daddr
), "g" (saddr
), "g" ((ntohs(len
)<<16)+proto
*256), "0" (sum
));
102 * csum_tcpup_magic - Compute an IPv4 pseudo header checksum.
103 * @saddr: source address
104 * @daddr: destination address
105 * @len: length of packet
106 * @proto: ip protocol of packet
107 * @sum: initial sum to be added in (32bit unfolded)
109 * Returns the 16bit pseudo header checksum the input data already
110 * complemented and ready to be filled in.
112 static inline unsigned short int
113 csum_tcpudp_magic(unsigned long saddr
, unsigned long daddr
,
114 unsigned short len
, unsigned short proto
, unsigned int sum
)
116 return csum_fold(csum_tcpudp_nofold(saddr
,daddr
,len
,proto
,sum
));
120 * csum_partial - Compute an internet checksum.
121 * @buff: buffer to be checksummed
122 * @len: length of buffer.
123 * @sum: initial sum to be added in (32bit unfolded)
125 * Returns the 32bit unfolded internet checksum of the buffer.
126 * Before filling it in it needs to be csum_fold()'ed.
127 * buff should be aligned to a 64bit boundary if possible.
129 extern unsigned int csum_partial(const unsigned char *buff
, unsigned len
, unsigned int sum
);
131 #define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER 1
132 #define HAVE_CSUM_COPY_USER 1
135 /* Do not call this directly. Use the wrappers below */
136 extern unsigned long csum_partial_copy_generic(const unsigned char *src
, const unsigned char *dst
,
139 int *src_err_ptr
, int *dst_err_ptr
);
142 extern unsigned int csum_partial_copy_from_user(const unsigned char __user
*src
, unsigned char *dst
,
143 int len
, unsigned int isum
, int *errp
);
144 extern unsigned int csum_partial_copy_to_user(const unsigned char *src
, unsigned char __user
*dst
,
145 int len
, unsigned int isum
, int *errp
);
146 extern unsigned int csum_partial_copy_nocheck(const unsigned char *src
, unsigned char *dst
, int len
,
149 /* Old names. To be removed. */
150 #define csum_and_copy_to_user csum_partial_copy_to_user
151 #define csum_and_copy_from_user csum_partial_copy_from_user
154 * ip_compute_csum - Compute an 16bit IP checksum.
155 * @buff: buffer address.
156 * @len: length of buffer.
158 * Returns the 16bit folded/inverted checksum of the passed buffer.
161 extern unsigned short ip_compute_csum(unsigned char * buff
, int len
);
164 * csum_ipv6_magic - Compute checksum of an IPv6 pseudo header.
165 * @saddr: source address
166 * @daddr: destination address
167 * @len: length of packet
168 * @proto: protocol of packet
169 * @sum: initial sum (32bit unfolded) to be added in
171 * Computes an IPv6 pseudo header checksum. This sum is added the checksum
172 * into UDP/TCP packets and contains some link layer information.
173 * Returns the unfolded 32bit checksum.
178 #define _HAVE_ARCH_IPV6_CSUM 1
179 extern unsigned short
180 csum_ipv6_magic(struct in6_addr
*saddr
, struct in6_addr
*daddr
,
181 __u32 len
, unsigned short proto
, unsigned int sum
);
183 static inline unsigned add32_with_carry(unsigned a
, unsigned b
)