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1da177e4 LT |
1 | /* |
2 | * This file is subject to the terms and conditions of the GNU General Public | |
3 | * License. See the file "COPYING" in the main directory of this archive | |
4 | * for more details. | |
5 | * | |
6 | * Copyright (C) 1995, 96, 97, 98, 99, 2001 by Ralf Baechle | |
7 | * Copyright (C) 1999 Silicon Graphics, Inc. | |
8 | * Copyright (C) 2001 Thiemo Seufer. | |
9 | * Copyright (C) 2002 Maciej W. Rozycki | |
10 | */ | |
11 | #ifndef _ASM_CHECKSUM_H | |
12 | #define _ASM_CHECKSUM_H | |
13 | ||
14 | #include <linux/config.h> | |
15 | #include <linux/in6.h> | |
16 | ||
17 | #include <asm/uaccess.h> | |
18 | ||
19 | /* | |
20 | * computes the checksum of a memory block at buff, length len, | |
21 | * and adds in "sum" (32-bit) | |
22 | * | |
23 | * returns a 32-bit number suitable for feeding into itself | |
24 | * or csum_tcpudp_magic | |
25 | * | |
26 | * this function must be called with even lengths, except | |
27 | * for the last fragment, which may be odd | |
28 | * | |
29 | * it's best to have buff aligned on a 32-bit boundary | |
30 | */ | |
31 | unsigned int csum_partial(const unsigned char *buff, int len, unsigned int sum); | |
32 | ||
33 | /* | |
34 | * this is a new version of the above that records errors it finds in *errp, | |
35 | * but continues and zeros the rest of the buffer. | |
36 | */ | |
fe00f943 RB |
37 | unsigned int csum_partial_copy_from_user(const unsigned char __user *src, |
38 | unsigned char *dst, int len, | |
39 | unsigned int sum, int *errp); | |
1da177e4 LT |
40 | |
41 | /* | |
42 | * Copy and checksum to user | |
43 | */ | |
44 | #define HAVE_CSUM_COPY_USER | |
45 | static inline unsigned int csum_and_copy_to_user (const unsigned char *src, | |
46 | unsigned char __user *dst, | |
47 | int len, int sum, | |
48 | int *err_ptr) | |
49 | { | |
50 | might_sleep(); | |
51 | sum = csum_partial(src, len, sum); | |
52 | ||
53 | if (copy_to_user(dst, src, len)) { | |
54 | *err_ptr = -EFAULT; | |
55 | return -1; | |
56 | } | |
57 | ||
58 | return sum; | |
59 | } | |
60 | ||
61 | /* | |
62 | * the same as csum_partial, but copies from user space (but on MIPS | |
63 | * we have just one address space, so this is identical to the above) | |
64 | */ | |
65 | unsigned int csum_partial_copy_nocheck(const unsigned char *src, unsigned char *dst, | |
66 | int len, unsigned int sum); | |
67 | ||
68 | /* | |
69 | * Fold a partial checksum without adding pseudo headers | |
70 | */ | |
71 | static inline unsigned short int csum_fold(unsigned int sum) | |
72 | { | |
73 | __asm__( | |
04988d6f TS |
74 | " .set push # csum_fold\n" |
75 | " .set noat \n" | |
76 | " sll $1, %0, 16 \n" | |
77 | " addu %0, $1 \n" | |
78 | " sltu $1, %0, $1 \n" | |
79 | " srl %0, %0, 16 \n" | |
80 | " addu %0, $1 \n" | |
81 | " xori %0, 0xffff \n" | |
82 | " .set pop" | |
1da177e4 LT |
83 | : "=r" (sum) |
84 | : "0" (sum)); | |
85 | ||
86 | return sum; | |
87 | } | |
88 | ||
89 | /* | |
90 | * This is a version of ip_compute_csum() optimized for IP headers, | |
91 | * which always checksum on 4 octet boundaries. | |
92 | * | |
93 | * By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by | |
94 | * Arnt Gulbrandsen. | |
95 | */ | |
96 | static inline unsigned short ip_fast_csum(unsigned char *iph, unsigned int ihl) | |
97 | { | |
98 | unsigned int *word = (unsigned int *) iph; | |
99 | unsigned int *stop = word + ihl; | |
100 | unsigned int csum; | |
101 | int carry; | |
102 | ||
103 | csum = word[0]; | |
104 | csum += word[1]; | |
105 | carry = (csum < word[1]); | |
106 | csum += carry; | |
107 | ||
108 | csum += word[2]; | |
109 | carry = (csum < word[2]); | |
110 | csum += carry; | |
111 | ||
112 | csum += word[3]; | |
113 | carry = (csum < word[3]); | |
114 | csum += carry; | |
115 | ||
116 | word += 4; | |
117 | do { | |
118 | csum += *word; | |
119 | carry = (csum < *word); | |
120 | csum += carry; | |
121 | word++; | |
122 | } while (word != stop); | |
123 | ||
124 | return csum_fold(csum); | |
125 | } | |
126 | ||
127 | static inline unsigned int csum_tcpudp_nofold(unsigned long saddr, | |
128 | unsigned long daddr, unsigned short len, unsigned short proto, | |
129 | unsigned int sum) | |
130 | { | |
131 | __asm__( | |
04988d6f TS |
132 | " .set push # csum_tcpudp_nofold\n" |
133 | " .set noat \n" | |
875d43e7 | 134 | #ifdef CONFIG_32BIT |
04988d6f TS |
135 | " addu %0, %2 \n" |
136 | " sltu $1, %0, %2 \n" | |
137 | " addu %0, $1 \n" | |
1da177e4 | 138 | |
04988d6f TS |
139 | " addu %0, %3 \n" |
140 | " sltu $1, %0, %3 \n" | |
141 | " addu %0, $1 \n" | |
1da177e4 | 142 | |
04988d6f TS |
143 | " addu %0, %4 \n" |
144 | " sltu $1, %0, %4 \n" | |
145 | " addu %0, $1 \n" | |
1da177e4 | 146 | #endif |
875d43e7 | 147 | #ifdef CONFIG_64BIT |
04988d6f TS |
148 | " daddu %0, %2 \n" |
149 | " daddu %0, %3 \n" | |
150 | " daddu %0, %4 \n" | |
151 | " dsll32 $1, %0, 0 \n" | |
152 | " daddu %0, $1 \n" | |
153 | " dsrl32 %0, %0, 0 \n" | |
1da177e4 | 154 | #endif |
04988d6f | 155 | " .set pop" |
1da177e4 LT |
156 | : "=r" (sum) |
157 | : "0" (daddr), "r"(saddr), | |
158 | #ifdef __MIPSEL__ | |
159 | "r" (((unsigned long)htons(len)<<16) + proto*256), | |
160 | #else | |
161 | "r" (((unsigned long)(proto)<<16) + len), | |
162 | #endif | |
163 | "r" (sum)); | |
164 | ||
165 | return sum; | |
166 | } | |
167 | ||
168 | /* | |
169 | * computes the checksum of the TCP/UDP pseudo-header | |
170 | * returns a 16-bit checksum, already complemented | |
171 | */ | |
172 | static inline unsigned short int csum_tcpudp_magic(unsigned long saddr, | |
173 | unsigned long daddr, | |
174 | unsigned short len, | |
175 | unsigned short proto, | |
176 | unsigned int sum) | |
177 | { | |
178 | return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); | |
179 | } | |
180 | ||
181 | /* | |
182 | * this routine is used for miscellaneous IP-like checksums, mainly | |
183 | * in icmp.c | |
184 | */ | |
185 | static inline unsigned short ip_compute_csum(unsigned char * buff, int len) | |
186 | { | |
187 | return csum_fold(csum_partial(buff, len, 0)); | |
188 | } | |
189 | ||
190 | #define _HAVE_ARCH_IPV6_CSUM | |
191 | static __inline__ unsigned short int csum_ipv6_magic(struct in6_addr *saddr, | |
192 | struct in6_addr *daddr, | |
193 | __u32 len, | |
194 | unsigned short proto, | |
195 | unsigned int sum) | |
196 | { | |
197 | __asm__( | |
04988d6f TS |
198 | " .set push # csum_ipv6_magic\n" |
199 | " .set noreorder \n" | |
200 | " .set noat \n" | |
201 | " addu %0, %5 # proto (long in network byte order)\n" | |
202 | " sltu $1, %0, %5 \n" | |
203 | " addu %0, $1 \n" | |
204 | ||
205 | " addu %0, %6 # csum\n" | |
206 | " sltu $1, %0, %6 \n" | |
207 | " lw %1, 0(%2) # four words source address\n" | |
208 | " addu %0, $1 \n" | |
209 | " addu %0, %1 \n" | |
210 | " sltu $1, %0, %1 \n" | |
211 | ||
212 | " lw %1, 4(%2) \n" | |
213 | " addu %0, $1 \n" | |
214 | " addu %0, %1 \n" | |
215 | " sltu $1, %0, %1 \n" | |
216 | ||
217 | " lw %1, 8(%2) \n" | |
218 | " addu %0, $1 \n" | |
219 | " addu %0, %1 \n" | |
220 | " sltu $1, %0, %1 \n" | |
221 | ||
222 | " lw %1, 12(%2) \n" | |
223 | " addu %0, $1 \n" | |
224 | " addu %0, %1 \n" | |
225 | " sltu $1, %0, %1 \n" | |
226 | ||
227 | " lw %1, 0(%3) \n" | |
228 | " addu %0, $1 \n" | |
229 | " addu %0, %1 \n" | |
230 | " sltu $1, %0, %1 \n" | |
231 | ||
232 | " lw %1, 4(%3) \n" | |
233 | " addu %0, $1 \n" | |
234 | " addu %0, %1 \n" | |
235 | " sltu $1, %0, %1 \n" | |
236 | ||
237 | " lw %1, 8(%3) \n" | |
238 | " addu %0, $1 \n" | |
239 | " addu %0, %1 \n" | |
240 | " sltu $1, %0, %1 \n" | |
241 | ||
242 | " lw %1, 12(%3) \n" | |
243 | " addu %0, $1 \n" | |
244 | " addu %0, %1 \n" | |
245 | " sltu $1, %0, %1 \n" | |
246 | ||
247 | " addu %0, $1 # Add final carry\n" | |
248 | " .set pop" | |
1da177e4 LT |
249 | : "=r" (sum), "=r" (proto) |
250 | : "r" (saddr), "r" (daddr), | |
251 | "0" (htonl(len)), "1" (htonl(proto)), "r" (sum)); | |
252 | ||
253 | return csum_fold(sum); | |
254 | } | |
255 | ||
256 | #endif /* _ASM_CHECKSUM_H */ |