/* * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (C) 1995, 96, 97, 98, 99, 2001 by Ralf Baechle * Copyright (C) 1999 Silicon Graphics, Inc. * Copyright (C) 2001 Thiemo Seufer. * Copyright (C) 2002 Maciej W. Rozycki */ #ifndef _ASM_CHECKSUM_H #define _ASM_CHECKSUM_H #include <linux/in6.h> #include <asm/uaccess.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 */ __wsum csum_partial(const void *buff, int len, __wsum sum); __wsum __csum_partial_copy_user(const void *src, void *dst, int len, __wsum sum, int *err_ptr); /* * this is a new version of the above that records errors it finds in *errp, * but continues and zeros the rest of the buffer. */ static inline __wsum csum_partial_copy_from_user(const void __user *src, void *dst, int len, __wsum sum, int *err_ptr) { might_sleep(); return __csum_partial_copy_user((__force void *)src, dst, len, sum, err_ptr); } /* * Copy and checksum to user */ #define HAVE_CSUM_COPY_USER static inline __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len, __wsum sum, int *err_ptr) { might_sleep(); if (access_ok(VERIFY_WRITE, dst, len)) return __csum_partial_copy_user(src, (__force void *)dst, len, sum, err_ptr); if (len) *err_ptr = -EFAULT; return (__force __wsum)-1; /* invalid checksum */ } /* * the same as csum_partial, but copies from user space (but on MIPS * we have just one address space, so this is identical to the above) */ __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum); /* * Fold a partial checksum without adding pseudo headers */ static inline __sum16 csum_fold(__wsum sum) { __asm__( " .set push # csum_fold\n" " .set noat \n" " sll $1, %0, 16 \n" " addu %0, $1 \n" " sltu $1, %0, $1 \n" " srl %0, %0, 16 \n" " addu %0, $1 \n" " xori %0, 0xffff \n" " .set pop" : "=r" (sum) : "0" (sum)); return (__force __sum16)sum; } /* * This is a version of ip_compute_csum() optimized for IP headers, * which always checksum on 4 octet boundaries. * * By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by * Arnt Gulbrandsen. */ static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) { const unsigned int *word = iph; const unsigned int *stop = word + ihl; unsigned int csum; int carry; csum = word[0]; csum += word[1]; carry = (csum < word[1]); csum += carry; csum += word[2]; carry = (csum < word[2]); csum += carry; csum += word[3]; carry = (csum < word[3]); csum += carry; word += 4; do { csum += *word; carry = (csum < *word); csum += carry; word++; } while (word != stop); return csum_fold(csum); } static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len, unsigned short proto, __wsum sum) { __asm__( " .set push # csum_tcpudp_nofold\n" " .set noat \n" #ifdef CONFIG_32BIT " addu %0, %2 \n" " sltu $1, %0, %2 \n" " addu %0, $1 \n" " addu %0, %3 \n" " sltu $1, %0, %3 \n" " addu %0, $1 \n" " addu %0, %4 \n" " sltu $1, %0, %4 \n" " addu %0, $1 \n" #endif #ifdef CONFIG_64BIT " daddu %0, %2 \n" " daddu %0, %3 \n" " daddu %0, %4 \n" " dsll32 $1, %0, 0 \n" " daddu %0, $1 \n" " dsra32 %0, %0, 0 \n" #endif " .set pop" : "=r" (sum) : "0" ((__force unsigned long)daddr), "r" ((__force unsigned long)saddr), #ifdef __MIPSEL__ "r" ((proto + len) << 8), #else "r" (proto + len), #endif "r" (sum)); return sum; } /* * computes the checksum of the TCP/UDP pseudo-header * returns a 16-bit checksum, already complemented */ static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, unsigned short len, unsigned short proto, __wsum 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 __sum16 ip_compute_csum(const void *buff, int len) { return csum_fold(csum_partial(buff, len, 0)); } #define _HAVE_ARCH_IPV6_CSUM static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr, __u32 len, unsigned short proto, __wsum sum) { __asm__( " .set push # csum_ipv6_magic\n" " .set noreorder \n" " .set noat \n" " addu %0, %5 # proto (long in network byte order)\n" " sltu $1, %0, %5 \n" " addu %0, $1 \n" " addu %0, %6 # csum\n" " sltu $1, %0, %6 \n" " lw %1, 0(%2) # four words source address\n" " addu %0, $1 \n" " addu %0, %1 \n" " sltu $1, %0, %1 \n" " lw %1, 4(%2) \n" " addu %0, $1 \n" " addu %0, %1 \n" " sltu $1, %0, %1 \n" " lw %1, 8(%2) \n" " addu %0, $1 \n" " addu %0, %1 \n" " sltu $1, %0, %1 \n" " lw %1, 12(%2) \n" " addu %0, $1 \n" " addu %0, %1 \n" " sltu $1, %0, %1 \n" " lw %1, 0(%3) \n" " addu %0, $1 \n" " addu %0, %1 \n" " sltu $1, %0, %1 \n" " lw %1, 4(%3) \n" " addu %0, $1 \n" " addu %0, %1 \n" " sltu $1, %0, %1 \n" " lw %1, 8(%3) \n" " addu %0, $1 \n" " addu %0, %1 \n" " sltu $1, %0, %1 \n" " lw %1, 12(%3) \n" " addu %0, $1 \n" " addu %0, %1 \n" " sltu $1, %0, %1 \n" " addu %0, $1 # Add final carry\n" " .set pop" : "=r" (sum), "=r" (proto) : "r" (saddr), "r" (daddr), "0" (htonl(len)), "1" (htonl(proto)), "r" (sum)); return csum_fold(sum); } #endif /* _ASM_CHECKSUM_H */