/* * Copyright (c) 2000 Apple Computer, Inc. All rights reserved. * * @APPLE_LICENSE_HEADER_START@ * * The contents of this file constitute Original Code as defined in and * are subject to the Apple Public Source License Version 1.1 (the * "License"). You may not use this file except in compliance with the * License. Please obtain a copy of the License at * http://www.apple.com/publicsource and read it before using this file. * * This Original Code and all software distributed under the License are * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the * License for the specific language governing rights and limitations * under the License. * * @APPLE_LICENSE_HEADER_END@ */ /* * Copyright (c) 1988, 1992, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)in_cksum.c 8.1 (Berkeley) 6/10/93 */ #include <sys/param.h> #include <sys/mbuf.h> #include <sys/kdebug.h> #define DBG_FNC_IN_CKSUM NETDBG_CODE(DBG_NETIP, (3 << 8)) /* * Checksum routine for Internet Protocol family headers (Portable Version). * * This routine is very heavily used in the network * code and should be modified for each CPU to be as fast as possible. */ #if defined(ppc) int in_cksum(m, len) register struct mbuf *m; register int len; { register u_short *w; register int sum = 0; register int mlen = 0; int starting_on_odd = 0; KERNEL_DEBUG(DBG_FNC_IN_CKSUM | DBG_FUNC_START, len,0,0,0,0); for (;m && len; m = m->m_next) { if (m->m_len == 0) continue; mlen = m->m_len; w = mtod(m, u_short *); if (len < mlen) mlen = len; sum = xsum_assym(w, mlen, sum, starting_on_odd); len -= mlen; if (mlen & 0x1) { if (starting_on_odd) starting_on_odd = 0; else starting_on_odd = 1; } } KERNEL_DEBUG(DBG_FNC_IN_CKSUM | DBG_FUNC_END, 0,0,0,0,0); return (~sum & 0xffff); } #else #define ADDCARRY(x) (x > 65535 ? x -= 65535 : x) #define REDUCE {l_util.l = sum; sum = l_util.s[0] + l_util.s[1]; ADDCARRY(sum);} int in_cksum(m, len) register struct mbuf *m; register int len; { register u_short *w; register int sum = 0; register int mlen = 0; int byte_swapped = 0; union { char c[2]; u_short s; } s_util; union { u_short s[2]; long l; } l_util; KERNEL_DEBUG(DBG_FNC_IN_CKSUM | DBG_FUNC_START, len,0,0,0,0); for (;m && len; m = m->m_next) { if (m->m_len == 0) continue; w = mtod(m, u_short *); if (mlen == -1) { /* * The first byte of this mbuf is the continuation * of a word spanning between this mbuf and the * last mbuf. * * s_util.c[0] is already saved when scanning previous * mbuf. */ s_util.c[1] = *(char *)w; sum += s_util.s; w = (u_short *)((char *)w + 1); mlen = m->m_len - 1; len--; } else mlen = m->m_len; if (len < mlen) mlen = len; len -= mlen; /* * Force to even boundary. */ if ((1 & (int) w) && (mlen > 0)) { REDUCE; sum <<= 8; s_util.c[0] = *(u_char *)w; w = (u_short *)((char *)w + 1); mlen--; byte_swapped = 1; } /* * Unroll the loop to make overhead from * branches &c small. */ while ((mlen -= 32) >= 0) { sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3]; sum += w[4]; sum += w[5]; sum += w[6]; sum += w[7]; sum += w[8]; sum += w[9]; sum += w[10]; sum += w[11]; sum += w[12]; sum += w[13]; sum += w[14]; sum += w[15]; w += 16; } mlen += 32; while ((mlen -= 8) >= 0) { sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3]; w += 4; } mlen += 8; if (mlen == 0 && byte_swapped == 0) continue; REDUCE; while ((mlen -= 2) >= 0) { sum += *w++; } if (byte_swapped) { REDUCE; sum <<= 8; byte_swapped = 0; if (mlen == -1) { s_util.c[1] = *(char *)w; sum += s_util.s; mlen = 0; } else mlen = -1; } else if (mlen == -1) s_util.c[0] = *(char *)w; } if (len) printf("cksum: out of data\n"); if (mlen == -1) { /* The last mbuf has odd # of bytes. Follow the standard (the odd byte may be shifted left by 8 bits or not as determined by endian-ness of the machine) */ s_util.c[1] = 0; sum += s_util.s; } REDUCE; KERNEL_DEBUG(DBG_FNC_IN_CKSUM | DBG_FUNC_END, 0,0,0,0,0); return (~sum & 0xffff); } #endif