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1965aae3 PA |
1 | #ifndef _ASM_X86_CHECKSUM_32_H |
2 | #define _ASM_X86_CHECKSUM_32_H | |
1da177e4 LT |
3 | |
4 | #include <linux/in6.h> | |
13d4ea09 | 5 | #include <linux/uaccess.h> |
a9ed8817 | 6 | |
1da177e4 LT |
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 | */ | |
72685fcd | 19 | asmlinkage __wsum csum_partial(const void *buff, int len, __wsum sum); |
1da177e4 LT |
20 | |
21 | /* | |
22 | * the same as csum_partial, but copies from src while it | |
23 | * checksums, and handles user-space pointer exceptions correctly, when needed. | |
24 | * | |
25 | * here even more important to align src and dst on a 32-bit (or even | |
26 | * better 64-bit) boundary | |
27 | */ | |
28 | ||
72685fcd | 29 | asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst, |
0883e91a JP |
30 | int len, __wsum sum, |
31 | int *src_err_ptr, int *dst_err_ptr); | |
1da177e4 LT |
32 | |
33 | /* | |
34 | * Note: when you get a NULL pointer exception here this means someone | |
35 | * passed in an incorrect kernel address to one of these functions. | |
36 | * | |
37 | * If you use these functions directly please don't forget the | |
e49332bd | 38 | * access_ok(). |
1da177e4 | 39 | */ |
0883e91a JP |
40 | static inline __wsum csum_partial_copy_nocheck(const void *src, void *dst, |
41 | int len, __wsum sum) | |
1da177e4 | 42 | { |
0883e91a | 43 | return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL); |
1da177e4 LT |
44 | } |
45 | ||
0883e91a JP |
46 | static inline __wsum csum_partial_copy_from_user(const void __user *src, |
47 | void *dst, | |
48 | int len, __wsum sum, | |
49 | int *err_ptr) | |
1da177e4 | 50 | { |
7263dda4 PA |
51 | __wsum ret; |
52 | ||
1da177e4 | 53 | might_sleep(); |
7263dda4 PA |
54 | stac(); |
55 | ret = csum_partial_copy_generic((__force void *)src, dst, | |
56 | len, sum, err_ptr, NULL); | |
57 | clac(); | |
58 | ||
59 | return ret; | |
1da177e4 LT |
60 | } |
61 | ||
62 | /* | |
63 | * This is a version of ip_compute_csum() optimized for IP headers, | |
64 | * which always checksum on 4 octet boundaries. | |
65 | * | |
66 | * By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by | |
67 | * Arnt Gulbrandsen. | |
68 | */ | |
72685fcd | 69 | static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) |
1da177e4 LT |
70 | { |
71 | unsigned int sum; | |
72 | ||
0883e91a JP |
73 | asm volatile("movl (%1), %0 ;\n" |
74 | "subl $4, %2 ;\n" | |
75 | "jbe 2f ;\n" | |
76 | "addl 4(%1), %0 ;\n" | |
77 | "adcl 8(%1), %0 ;\n" | |
78 | "adcl 12(%1), %0;\n" | |
79 | "1: adcl 16(%1), %0 ;\n" | |
80 | "lea 4(%1), %1 ;\n" | |
81 | "decl %2 ;\n" | |
82 | "jne 1b ;\n" | |
83 | "adcl $0, %0 ;\n" | |
84 | "movl %0, %2 ;\n" | |
85 | "shrl $16, %0 ;\n" | |
86 | "addw %w2, %w0 ;\n" | |
87 | "adcl $0, %0 ;\n" | |
88 | "notl %0 ;\n" | |
89 | "2: ;\n" | |
2c656491 | 90 | /* Since the input registers which are loaded with iph and ihl |
1da177e4 LT |
91 | are modified, we must also specify them as outputs, or gcc |
92 | will assume they contain their original values. */ | |
0883e91a JP |
93 | : "=r" (sum), "=r" (iph), "=r" (ihl) |
94 | : "1" (iph), "2" (ihl) | |
95 | : "memory"); | |
72685fcd | 96 | return (__force __sum16)sum; |
1da177e4 LT |
97 | } |
98 | ||
99 | /* | |
100 | * Fold a partial checksum | |
101 | */ | |
102 | ||
72685fcd | 103 | static inline __sum16 csum_fold(__wsum sum) |
1da177e4 | 104 | { |
0883e91a JP |
105 | asm("addl %1, %0 ;\n" |
106 | "adcl $0xffff, %0 ;\n" | |
107 | : "=r" (sum) | |
108 | : "r" ((__force u32)sum << 16), | |
109 | "0" ((__force u32)sum & 0xffff0000)); | |
72685fcd | 110 | return (__force __sum16)(~(__force u32)sum >> 16); |
1da177e4 LT |
111 | } |
112 | ||
72685fcd | 113 | static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, |
01cfbad7 | 114 | __u32 len, __u8 proto, |
0883e91a | 115 | __wsum sum) |
1da177e4 | 116 | { |
0883e91a JP |
117 | asm("addl %1, %0 ;\n" |
118 | "adcl %2, %0 ;\n" | |
119 | "adcl %3, %0 ;\n" | |
120 | "adcl $0, %0 ;\n" | |
121 | : "=r" (sum) | |
122 | : "g" (daddr), "g"(saddr), | |
123 | "g" ((len + proto) << 8), "0" (sum)); | |
124 | return sum; | |
1da177e4 LT |
125 | } |
126 | ||
127 | /* | |
128 | * computes the checksum of the TCP/UDP pseudo-header | |
129 | * returns a 16-bit checksum, already complemented | |
130 | */ | |
72685fcd | 131 | static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, |
01cfbad7 | 132 | __u32 len, __u8 proto, |
0883e91a | 133 | __wsum sum) |
1da177e4 | 134 | { |
0883e91a | 135 | return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); |
1da177e4 LT |
136 | } |
137 | ||
138 | /* | |
139 | * this routine is used for miscellaneous IP-like checksums, mainly | |
140 | * in icmp.c | |
141 | */ | |
142 | ||
72685fcd | 143 | static inline __sum16 ip_compute_csum(const void *buff, int len) |
1da177e4 | 144 | { |
0883e91a | 145 | return csum_fold(csum_partial(buff, len, 0)); |
1da177e4 LT |
146 | } |
147 | ||
148 | #define _HAVE_ARCH_IPV6_CSUM | |
0883e91a JP |
149 | static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr, |
150 | const struct in6_addr *daddr, | |
1e940829 | 151 | __u32 len, __u8 proto, __wsum sum) |
1da177e4 | 152 | { |
0883e91a JP |
153 | asm("addl 0(%1), %0 ;\n" |
154 | "adcl 4(%1), %0 ;\n" | |
155 | "adcl 8(%1), %0 ;\n" | |
156 | "adcl 12(%1), %0 ;\n" | |
157 | "adcl 0(%2), %0 ;\n" | |
158 | "adcl 4(%2), %0 ;\n" | |
159 | "adcl 8(%2), %0 ;\n" | |
160 | "adcl 12(%2), %0 ;\n" | |
161 | "adcl %3, %0 ;\n" | |
162 | "adcl %4, %0 ;\n" | |
163 | "adcl $0, %0 ;\n" | |
164 | : "=&r" (sum) | |
165 | : "r" (saddr), "r" (daddr), | |
392d814d ST |
166 | "r" (htonl(len)), "r" (htonl(proto)), "0" (sum) |
167 | : "memory"); | |
1da177e4 LT |
168 | |
169 | return csum_fold(sum); | |
170 | } | |
171 | ||
172 | /* | |
173 | * Copy and checksum to user | |
174 | */ | |
175 | #define HAVE_CSUM_COPY_USER | |
0883e91a JP |
176 | static inline __wsum csum_and_copy_to_user(const void *src, |
177 | void __user *dst, | |
178 | int len, __wsum sum, | |
179 | int *err_ptr) | |
1da177e4 | 180 | { |
7263dda4 PA |
181 | __wsum ret; |
182 | ||
1da177e4 | 183 | might_sleep(); |
7263dda4 PA |
184 | if (access_ok(VERIFY_WRITE, dst, len)) { |
185 | stac(); | |
186 | ret = csum_partial_copy_generic(src, (__force void *)dst, | |
187 | len, sum, NULL, err_ptr); | |
188 | clac(); | |
189 | return ret; | |
190 | } | |
1da177e4 LT |
191 | |
192 | if (len) | |
193 | *err_ptr = -EFAULT; | |
194 | ||
72685fcd | 195 | return (__force __wsum)-1; /* invalid checksum */ |
1da177e4 LT |
196 | } |
197 | ||
1965aae3 | 198 | #endif /* _ASM_X86_CHECKSUM_32_H */ |