1#ifndef _BFIN_CHECKSUM_H 2#define _BFIN_CHECKSUM_H 3 4/* 5 * MODIFIED FOR BFIN April 30, 2001 akbar.hussain@lineo.com 6 * 7 * computes the checksum of a memory block at buff, length len, 8 * and adds in "sum" (32-bit) 9 * 10 * returns a 32-bit number suitable for feeding into itself 11 * or csum_tcpudp_magic 12 * 13 * this function must be called with even lengths, except 14 * for the last fragment, which may be odd 15 * 16 * it's best to have buff aligned on a 32-bit boundary 17 */ 18unsigned int csum_partial(const unsigned char *buff, int len, unsigned int sum); 19 20/* 21 * the same as csum_partial, but copies from src while it 22 * checksums 23 * 24 * here even more important to align src and dst on a 32-bit (or even 25 * better 64-bit) boundary 26 */ 27 28unsigned int csum_partial_copy(const unsigned char *src, unsigned char *dst, 29 int len, int sum); 30 31/* 32 * the same as csum_partial_copy, but copies from user space. 33 * 34 * here even more important to align src and dst on a 32-bit (or even 35 * better 64-bit) boundary 36 */ 37 38extern unsigned int csum_partial_copy_from_user(const unsigned char *src, 39 unsigned char *dst, int len, 40 int sum, int *csum_err); 41 42#define csum_partial_copy_nocheck(src, dst, len, sum) \ 43 csum_partial_copy((src), (dst), (len), (sum)) 44 45unsigned short ip_fast_csum(unsigned char *iph, unsigned int ihl); 46 47/* 48 * Fold a partial checksum 49 */ 50 51static inline unsigned int csum_fold(unsigned int sum) 52{ 53 while (sum >> 16) 54 sum = (sum & 0xffff) + (sum >> 16); 55 return ((~(sum << 16)) >> 16); 56} 57 58/* 59 * computes the checksum of the TCP/UDP pseudo-header 60 * returns a 16-bit checksum, already complemented 61 */ 62 63static inline unsigned int 64csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr, unsigned short len, 65 unsigned short proto, unsigned int sum) 66{ 67 68 __asm__ ("%0 = %0 + %1;\n\t" 69 "CC = AC0;\n\t" 70 "if !CC jump 4;\n\t" 71 "%0 = %0 + %4;\n\t" 72 "%0 = %0 + %2;\n\t" 73 "CC = AC0;\n\t" 74 "if !CC jump 4;\n\t" 75 "%0 = %0 + %4;\n\t" 76 "%0 = %0 + %3;\n\t" 77 "CC = AC0;\n\t" 78 "if !CC jump 4;\n\t" 79 "%0 = %0 + %4;\n\t" 80 "NOP;\n\t" 81 : "=d" (sum) 82 : "d" (daddr), "d" (saddr), "d" ((ntohs(len)<<16)+proto*256), "d" (1), "0"(sum)); 83 84 return (sum); 85} 86 87static inline unsigned short int 88csum_tcpudp_magic(unsigned long saddr, unsigned long daddr, unsigned short len, 89 unsigned short proto, unsigned int sum) 90{ 91 return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); 92} 93 94/* 95 * this routine is used for miscellaneous IP-like checksums, mainly 96 * in icmp.c 97 */ 98 99extern unsigned short ip_compute_csum(const unsigned char *buff, int len); 100 101#endif /* _BFIN_CHECKSUM_H */ 102