linux / linux / kernel / git / klassert / ipsec-next / 4d78b6c78ae6d87e4c1c8072f42efa716f04afb9 / . / include / asm-cris / checksum.h

/* 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 | |

*/ | |

extern 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. | |

* | |

*/ | |

extern 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 | |

*/ | |

extern 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 | |

*/ | |

extern inline unsigned short ip_compute_csum(unsigned char * buff, int len) { | |

return csum_fold (csum_partial(buff, len, 0)); | |

} | |

#endif |