/* TODO: csum_tcpudp_magic could be speeded up, and csum_fold as well */ #ifndef _CRIS_CHECKSUM_H #define _CRIS_CHECKSUM_H #include <asm/arch/checksum.h> /* * 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 * * 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, unsigned int sum); /* * Fold a partial checksum into a word */ static inline unsigned int csum_fold(unsigned int sum) { /* the while loop is unnecessary really, it's always enough with two iterations */ while(sum >> 16) sum = (sum & 0xffff) + (sum >> 16); /* add in end-around carry */ return ~sum; } extern unsigned int csum_partial_copy_from_user(const char *src, char *dst, int len, unsigned int sum, int *errptr); /* * This is a version of ip_compute_csum() optimized for IP headers, * which always checksum on 4 octet boundaries. * */ static inline unsigned short ip_fast_csum(unsigned char * iph, unsigned int ihl) { return csum_fold(csum_partial(iph, ihl * 4, 0)); } /* * 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)); } #endif