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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 | /* * linux/include/asm-arm/checksum.h * * IP checksum routines * * Copyright (C) Original authors of ../asm-i386/checksum.h * Copyright (C) 1996,1997,1998 Russell King */ #ifndef __ASM_ARM_CHECKSUM_H #define __ASM_ARM_CHECKSUM_H #ifndef __ASM_ARM_SEGMENT_H #include <asm/segment.h> #endif /* * computes the checksum of a memory block at buff, length len, * and adds in "sum" (32-bit) * * returns a 32-bit number suitable for feeding into itself * or csum_tcpudp_magic * * this function must be called with even lengths, except * for the last fragment, which may be odd * * it's best to have buff aligned on a 32-bit boundary */ unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum); /* * the same as csum_partial, but copies from src while it * checksums, and handles user-space pointer exceptions correctly, when needed. * * here even more important to align src and dst on a 32-bit (or even * better 64-bit) boundary */ unsigned int csum_partial_copy_nocheck(const char *src, char *dst, int len, int sum); unsigned int csum_partial_copy_from_user(const char *src, char *dst, int len, int sum, int *err_ptr); #if 0 /* * This combination is currently not used, but possible: */ unsigned int csum_partial_copy_to_user(const char *src, char *dst, int len, int sum, int *err_ptr); #endif /* * These are the old (and unsafe) way of doing checksums, a warning message will be * printed if they are used and an exception occurs. * * these functions should go away after some time. */ #define csum_partial_copy_fromuser csum_partial_copy unsigned int csum_partial_copy(const char *src, char *dst, int len, int sum); /* * This is a version of ip_compute_csum() optimized for IP headers, * which always checksum on 4 octet boundaries. * * Converted and optimised for ARM by R. M. King. * * Note: the order that the LDM registers are loaded with respect to * the adc's doesn't matter. */ static inline unsigned short ip_fast_csum(unsigned char * iph, unsigned int ihl) { unsigned int sum, tmp1; __asm__ __volatile__(" sub %2, %2, #5 ldr %0, [%1], #4 ldr %3, [%1], #4 adds %0, %0, %3 ldr %3, [%1], #4 adcs %0, %0, %3 ldr %3, [%1], #4 adcs %0, %0, %3 1: ldr %3, [%1], #4 adcs %0, %0, %3 tst %2, #15 subne %2, %2, #1 bne 1b adc %0, %0, #0 adds %0, %0, %0, lsl #16 addcs %0, %0, #0x10000 mvn %0, %0 mov %0, %0, lsr #16 " : "=&r" (sum), "=&r" (iph), "=&r" (ihl), "=&r" (tmp1) : "1" (iph), "2" (ihl)); return(sum); } /* * Fold a partial checksum without adding pseudo headers */ static inline unsigned int csum_fold(unsigned int sum) { __asm__(" adds %0, %0, %0, lsl #16 addcs %0, %0, #0x10000" : "=r" (sum) : "0" (sum)); return (~sum) >> 16; } static inline unsigned long csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr, unsigned short len, unsigned short proto, unsigned int sum) { __asm__(" adds %0, %0, %1 adcs %0, %0, %2 adcs %0, %0, %3 adc %0, %0, #0" : "=&r"(sum) : "r" (daddr), "r" (saddr), "r" ((ntohs(len)<<16)+proto*256), "0" (sum)); return sum; } /* * computes the checksum of the TCP/UDP pseudo-header * returns a 16-bit checksum, already complemented */ static inline unsigned short int csum_tcpudp_magic(unsigned long saddr, unsigned long daddr, unsigned short len, unsigned short proto, unsigned int sum) { return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); } /* * this routine is used for miscellaneous IP-like checksums, mainly * in icmp.c */ static inline unsigned short ip_compute_csum(unsigned char * buff, int len) { return csum_fold(csum_partial(buff, len, 0)); } #define _HAVE_ARCH_IPV6_CSUM extern unsigned long __csum_ipv6_magic(struct in6_addr *saddr, struct in6_addr *daddr, __u32 len, __u32 proto, unsigned int sum); extern __inline__ unsigned short int csum_ipv6_magic(struct in6_addr *saddr, struct in6_addr *daddr, __u16 len, unsigned short proto, unsigned int sum) { return csum_fold(__csum_ipv6_magic(saddr, daddr, htonl((__u32)len), htonl(proto), sum)); } #endif |