Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Licensed under the GPL |
| 3 | */ |
| 4 | |
| 5 | #ifndef __UM_SYSDEP_CHECKSUM_H |
| 6 | #define __UM_SYSDEP_CHECKSUM_H |
| 7 | |
| 8 | #include "linux/in6.h" |
| 9 | #include "linux/string.h" |
| 10 | |
| 11 | /* |
| 12 | * computes the checksum of a memory block at buff, length len, |
| 13 | * and adds in "sum" (32-bit) |
| 14 | * |
| 15 | * returns a 32-bit number suitable for feeding into itself |
| 16 | * or csum_tcpudp_magic |
| 17 | * |
| 18 | * this function must be called with even lengths, except |
| 19 | * for the last fragment, which may be odd |
| 20 | * |
| 21 | * it's best to have buff aligned on a 32-bit boundary |
| 22 | */ |
Al Viro | abf419b | 2006-11-14 21:19:22 -0800 | [diff] [blame] | 23 | __wsum csum_partial(const void *buff, int len, __wsum sum); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | |
| 25 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 26 | * Note: when you get a NULL pointer exception here this means someone |
| 27 | * passed in an incorrect kernel address to one of these functions. |
| 28 | * |
| 29 | * If you use these functions directly please don't forget the |
| 30 | * access_ok(). |
| 31 | */ |
| 32 | |
| 33 | static __inline__ |
Al Viro | abf419b | 2006-11-14 21:19:22 -0800 | [diff] [blame] | 34 | __wsum csum_partial_copy_nocheck(const void *src, void *dst, |
| 35 | int len, __wsum sum) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | { |
| 37 | memcpy(dst, src, len); |
Jesper Juhl | 014c254 | 2006-01-15 02:37:08 +0100 | [diff] [blame] | 38 | return csum_partial(dst, len, sum); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | } |
| 40 | |
Bodo Stroesser | 7d37c6d | 2005-05-05 16:15:36 -0700 | [diff] [blame] | 41 | /* |
| 42 | * the same as csum_partial, but copies from src while it |
| 43 | * checksums, and handles user-space pointer exceptions correctly, when needed. |
| 44 | * |
| 45 | * here even more important to align src and dst on a 32-bit (or even |
| 46 | * better 64-bit) boundary |
| 47 | */ |
| 48 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | static __inline__ |
Al Viro | abf419b | 2006-11-14 21:19:22 -0800 | [diff] [blame] | 50 | __wsum csum_partial_copy_from_user(const void __user *src, void *dst, |
| 51 | int len, __wsum sum, int *err_ptr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | { |
Al Viro | abf419b | 2006-11-14 21:19:22 -0800 | [diff] [blame] | 53 | if (copy_from_user(dst, src, len)) { |
Bodo Stroesser | 7d37c6d | 2005-05-05 16:15:36 -0700 | [diff] [blame] | 54 | *err_ptr = -EFAULT; |
Al Viro | abf419b | 2006-11-14 21:19:22 -0800 | [diff] [blame] | 55 | return (__force __wsum)-1; |
Bodo Stroesser | 7d37c6d | 2005-05-05 16:15:36 -0700 | [diff] [blame] | 56 | } |
| 57 | |
| 58 | return csum_partial(dst, len, sum); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | } |
| 60 | |
| 61 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | * This is a version of ip_compute_csum() optimized for IP headers, |
| 63 | * which always checksum on 4 octet boundaries. |
| 64 | * |
| 65 | * By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by |
| 66 | * Arnt Gulbrandsen. |
| 67 | */ |
Al Viro | abf419b | 2006-11-14 21:19:22 -0800 | [diff] [blame] | 68 | static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 69 | { |
| 70 | unsigned int sum; |
| 71 | |
| 72 | __asm__ __volatile__( |
| 73 | "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" |
| 90 | /* Since the input registers which are loaded with iph and ipl |
| 91 | are modified, we must also specify them as outputs, or gcc |
| 92 | will assume they contain their original values. */ |
| 93 | : "=r" (sum), "=r" (iph), "=r" (ihl) |
| 94 | : "1" (iph), "2" (ihl) |
| 95 | : "memory"); |
Al Viro | abf419b | 2006-11-14 21:19:22 -0800 | [diff] [blame] | 96 | return (__force __sum16)sum; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 97 | } |
| 98 | |
| 99 | /* |
| 100 | * Fold a partial checksum |
| 101 | */ |
| 102 | |
Al Viro | abf419b | 2006-11-14 21:19:22 -0800 | [diff] [blame] | 103 | static inline __sum16 csum_fold(__wsum sum) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 104 | { |
| 105 | __asm__( |
| 106 | "addl %1, %0 ;\n" |
| 107 | "adcl $0xffff, %0 ;\n" |
| 108 | : "=r" (sum) |
Al Viro | abf419b | 2006-11-14 21:19:22 -0800 | [diff] [blame] | 109 | : "r" ((__force u32)sum << 16), |
| 110 | "0" ((__force u32)sum & 0xffff0000) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | ); |
Al Viro | abf419b | 2006-11-14 21:19:22 -0800 | [diff] [blame] | 112 | return (__force __sum16)(~(__force u32)sum >> 16); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 113 | } |
| 114 | |
Al Viro | abf419b | 2006-11-14 21:19:22 -0800 | [diff] [blame] | 115 | static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | unsigned short len, |
| 117 | unsigned short proto, |
Al Viro | abf419b | 2006-11-14 21:19:22 -0800 | [diff] [blame] | 118 | __wsum sum) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 119 | { |
| 120 | __asm__( |
| 121 | "addl %1, %0 ;\n" |
| 122 | "adcl %2, %0 ;\n" |
| 123 | "adcl %3, %0 ;\n" |
| 124 | "adcl $0, %0 ;\n" |
| 125 | : "=r" (sum) |
Al Viro | abf419b | 2006-11-14 21:19:22 -0800 | [diff] [blame] | 126 | : "g" (daddr), "g"(saddr), "g"((len + proto) << 8), "0"(sum)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 127 | return sum; |
| 128 | } |
| 129 | |
| 130 | /* |
| 131 | * computes the checksum of the TCP/UDP pseudo-header |
| 132 | * returns a 16-bit checksum, already complemented |
| 133 | */ |
Al Viro | abf419b | 2006-11-14 21:19:22 -0800 | [diff] [blame] | 134 | static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 135 | unsigned short len, |
| 136 | unsigned short proto, |
Al Viro | abf419b | 2006-11-14 21:19:22 -0800 | [diff] [blame] | 137 | __wsum sum) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 138 | { |
| 139 | return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum)); |
| 140 | } |
| 141 | |
| 142 | /* |
| 143 | * this routine is used for miscellaneous IP-like checksums, mainly |
| 144 | * in icmp.c |
| 145 | */ |
| 146 | |
Al Viro | abf419b | 2006-11-14 21:19:22 -0800 | [diff] [blame] | 147 | static inline __sum16 ip_compute_csum(const void *buff, int len) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | { |
| 149 | return csum_fold (csum_partial(buff, len, 0)); |
| 150 | } |
| 151 | |
| 152 | #define _HAVE_ARCH_IPV6_CSUM |
Al Viro | abf419b | 2006-11-14 21:19:22 -0800 | [diff] [blame] | 153 | static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr, |
| 154 | const struct in6_addr *daddr, |
| 155 | __u32 len, unsigned short proto, |
| 156 | __wsum sum) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 157 | { |
| 158 | __asm__( |
| 159 | "addl 0(%1), %0 ;\n" |
| 160 | "adcl 4(%1), %0 ;\n" |
| 161 | "adcl 8(%1), %0 ;\n" |
| 162 | "adcl 12(%1), %0 ;\n" |
| 163 | "adcl 0(%2), %0 ;\n" |
| 164 | "adcl 4(%2), %0 ;\n" |
| 165 | "adcl 8(%2), %0 ;\n" |
| 166 | "adcl 12(%2), %0 ;\n" |
| 167 | "adcl %3, %0 ;\n" |
| 168 | "adcl %4, %0 ;\n" |
| 169 | "adcl $0, %0 ;\n" |
| 170 | : "=&r" (sum) |
| 171 | : "r" (saddr), "r" (daddr), |
| 172 | "r"(htonl(len)), "r"(htonl(proto)), "0"(sum)); |
| 173 | |
| 174 | return csum_fold(sum); |
| 175 | } |
| 176 | |
| 177 | /* |
| 178 | * Copy and checksum to user |
| 179 | */ |
| 180 | #define HAVE_CSUM_COPY_USER |
Al Viro | abf419b | 2006-11-14 21:19:22 -0800 | [diff] [blame] | 181 | static __inline__ __wsum csum_and_copy_to_user(const void *src, |
| 182 | void __user *dst, |
| 183 | int len, __wsum sum, int *err_ptr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | { |
Al Viro | abf419b | 2006-11-14 21:19:22 -0800 | [diff] [blame] | 185 | if (access_ok(VERIFY_WRITE, dst, len)) { |
| 186 | if (copy_to_user(dst, src, len)) { |
Bodo Stroesser | 7d37c6d | 2005-05-05 16:15:36 -0700 | [diff] [blame] | 187 | *err_ptr = -EFAULT; |
Al Viro | abf419b | 2006-11-14 21:19:22 -0800 | [diff] [blame] | 188 | return (__force __wsum)-1; |
Bodo Stroesser | 7d37c6d | 2005-05-05 16:15:36 -0700 | [diff] [blame] | 189 | } |
| 190 | |
| 191 | return csum_partial(src, len, sum); |
| 192 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 193 | |
| 194 | if (len) |
| 195 | *err_ptr = -EFAULT; |
| 196 | |
Al Viro | abf419b | 2006-11-14 21:19:22 -0800 | [diff] [blame] | 197 | return (__force __wsum)-1; /* invalid checksum */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | } |
| 199 | |
| 200 | #endif |
| 201 | |
| 202 | /* |
| 203 | * Overrides for Emacs so that we follow Linus's tabbing style. |
| 204 | * Emacs will notice this stuff at the end of the file and automatically |
| 205 | * adjust the settings for this buffer only. This must remain at the end |
| 206 | * of the file. |
| 207 | * --------------------------------------------------------------------------- |
| 208 | * Local variables: |
| 209 | * c-file-style: "linux" |
| 210 | * End: |
| 211 | */ |