1#ifndef _ASM_X86_CHECKSUM_32_H 2#define _ASM_X86_CHECKSUM_32_H 3 4#include <linux/in6.h> 5 6#include <asm/uaccess.h> 7 8/* 9 * computes the checksum of a memory block at buff, length len, 10 * and adds in "sum" (32-bit) 11 * 12 * returns a 32-bit number suitable for feeding into itself 13 * or csum_tcpudp_magic 14 * 15 * this function must be called with even lengths, except 16 * for the last fragment, which may be odd 17 * 18 * it's best to have buff aligned on a 32-bit boundary 19 */ 20asmlinkage __wsum csum_partial(const void *buff, int len, __wsum sum); 21 22/* 23 * the same as csum_partial, but copies from src while it 24 * checksums, and handles user-space pointer exceptions correctly, when needed. 25 * 26 * here even more important to align src and dst on a 32-bit (or even 27 * better 64-bit) boundary 28 */ 29 30asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst, 31 int len, __wsum sum, 32 int *src_err_ptr, int *dst_err_ptr); 33 34/* 35 * Note: when you get a NULL pointer exception here this means someone 36 * passed in an incorrect kernel address to one of these functions. 37 * 38 * If you use these functions directly please don't forget the 39 * access_ok(). 40 */ 41static inline __wsum csum_partial_copy_nocheck(const void *src, void *dst, 42 int len, __wsum sum) 43{ 44 return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL); 45} 46 47static inline __wsum csum_partial_copy_from_user(const void __user *src, 48 void *dst, 49 int len, __wsum sum, 50 int *err_ptr) 51{ 52 might_sleep(); 53 return csum_partial_copy_generic((__force void *)src, dst, 54 len, sum, err_ptr, NULL); 55} 56 57/* 58 * This is a version of ip_compute_csum() optimized for IP headers, 59 * which always checksum on 4 octet boundaries. 60 * 61 * By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by 62 * Arnt Gulbrandsen. 63 */ 64static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) 65{ 66 unsigned int sum; 67 68 asm volatile("movl (%1), %0 ;\n" 69 "subl $4, %2 ;\n" 70 "jbe 2f ;\n" 71 "addl 4(%1), %0 ;\n" 72 "adcl 8(%1), %0 ;\n" 73 "adcl 12(%1), %0;\n" 74 "1: adcl 16(%1), %0 ;\n" 75 "lea 4(%1), %1 ;\n" 76 "decl %2 ;\n" 77 "jne 1b ;\n" 78 "adcl $0, %0 ;\n" 79 "movl %0, %2 ;\n" 80 "shrl $16, %0 ;\n" 81 "addw %w2, %w0 ;\n" 82 "adcl $0, %0 ;\n" 83 "notl %0 ;\n" 84 "2: ;\n" 85 /* Since the input registers which are loaded with iph and ihl 86 are modified, we must also specify them as outputs, or gcc 87 will assume they contain their original values. */ 88 : "=r" (sum), "=r" (iph), "=r" (ihl) 89 : "1" (iph), "2" (ihl) 90 : "memory"); 91 return (__force __sum16)sum; 92} 93 94/* 95 * Fold a partial checksum 96 */ 97 98static inline __sum16 csum_fold(__wsum sum) 99{ 100 asm("addl %1, %0 ;\n" 101 "adcl $0xffff, %0 ;\n" 102 : "=r" (sum) 103 : "r" ((__force u32)sum << 16), 104 "0" ((__force u32)sum & 0xffff0000)); 105 return (__force __sum16)(~(__force u32)sum >> 16); 106} 107 108static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, 109 unsigned short len, 110 unsigned short proto, 111 __wsum sum) 112{ 113 asm("addl %1, %0 ;\n" 114 "adcl %2, %0 ;\n" 115 "adcl %3, %0 ;\n" 116 "adcl $0, %0 ;\n" 117 : "=r" (sum) 118 : "g" (daddr), "g"(saddr), 119 "g" ((len + proto) << 8), "0" (sum)); 120 return sum; 121} 122 123/* 124 * computes the checksum of the TCP/UDP pseudo-header 125 * returns a 16-bit checksum, already complemented 126 */ 127static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, 128 unsigned short len, 129 unsigned short proto, 130 __wsum sum) 131{ 132 return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); 133} 134 135/* 136 * this routine is used for miscellaneous IP-like checksums, mainly 137 * in icmp.c 138 */ 139 140static inline __sum16 ip_compute_csum(const void *buff, int len) 141{ 142 return csum_fold(csum_partial(buff, len, 0)); 143} 144 145#define _HAVE_ARCH_IPV6_CSUM 146static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr, 147 const struct in6_addr *daddr, 148 __u32 len, unsigned short proto, 149 __wsum sum) 150{ 151 asm("addl 0(%1), %0 ;\n" 152 "adcl 4(%1), %0 ;\n" 153 "adcl 8(%1), %0 ;\n" 154 "adcl 12(%1), %0 ;\n" 155 "adcl 0(%2), %0 ;\n" 156 "adcl 4(%2), %0 ;\n" 157 "adcl 8(%2), %0 ;\n" 158 "adcl 12(%2), %0 ;\n" 159 "adcl %3, %0 ;\n" 160 "adcl %4, %0 ;\n" 161 "adcl $0, %0 ;\n" 162 : "=&r" (sum) 163 : "r" (saddr), "r" (daddr), 164 "r" (htonl(len)), "r" (htonl(proto)), "0" (sum) 165 : "memory"); 166 167 return csum_fold(sum); 168} 169 170/* 171 * Copy and checksum to user 172 */ 173#define HAVE_CSUM_COPY_USER 174static inline __wsum csum_and_copy_to_user(const void *src, 175 void __user *dst, 176 int len, __wsum sum, 177 int *err_ptr) 178{ 179 might_sleep(); 180 if (access_ok(VERIFY_WRITE, dst, len)) 181 return csum_partial_copy_generic(src, (__force void *)dst, 182 len, sum, NULL, err_ptr); 183 184 if (len) 185 *err_ptr = -EFAULT; 186 187 return (__force __wsum)-1; /* invalid checksum */ 188} 189 190#endif /* _ASM_X86_CHECKSUM_32_H */ 191