1/* 2 * Copyright (c) 2000-2009 Apple Inc. All rights reserved. 3 * 4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ 5 * 6 * This file contains Original Code and/or Modifications of Original Code 7 * as defined in and that are subject to the Apple Public Source License 8 * Version 2.0 (the 'License'). You may not use this file except in 9 * compliance with the License. The rights granted to you under the License 10 * may not be used to create, or enable the creation or redistribution of, 11 * unlawful or unlicensed copies of an Apple operating system, or to 12 * circumvent, violate, or enable the circumvention or violation of, any 13 * terms of an Apple operating system software license agreement. 14 * 15 * Please obtain a copy of the License at 16 * http://www.opensource.apple.com/apsl/ and read it before using this file. 17 * 18 * The Original Code and all software distributed under the License are 19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER 20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, 21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. 23 * Please see the License for the specific language governing rights and 24 * limitations under the License. 25 * 26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ 27 */ 28/* 29 * Copyright (c) 1988, 1992, 1993 30 * The Regents of the University of California. All rights reserved. 31 * 32 * Redistribution and use in source and binary forms, with or without 33 * modification, are permitted provided that the following conditions 34 * are met: 35 * 1. Redistributions of source code must retain the above copyright 36 * notice, this list of conditions and the following disclaimer. 37 * 2. Redistributions in binary form must reproduce the above copyright 38 * notice, this list of conditions and the following disclaimer in the 39 * documentation and/or other materials provided with the distribution. 40 * 3. All advertising materials mentioning features or use of this software 41 * must display the following acknowledgement: 42 * This product includes software developed by the University of 43 * California, Berkeley and its contributors. 44 * 4. Neither the name of the University nor the names of its contributors 45 * may be used to endorse or promote products derived from this software 46 * without specific prior written permission. 47 * 48 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 51 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 58 * SUCH DAMAGE. 59 * 60 * @(#)in_cksum.c 8.1 (Berkeley) 6/10/93 61 */ 62 63#include <sys/param.h> 64#include <sys/mbuf.h> 65#include <sys/kdebug.h> 66#include <kern/debug.h> 67#include <netinet/in.h> 68#include <netinet/ip.h> 69#include <libkern/libkern.h> 70 71#define DBG_FNC_IN_CKSUM NETDBG_CODE(DBG_NETIP, (3 << 8)) 72 73/* 74 * Checksum routine for Internet Protocol family headers (Portable Version). 75 * 76 * This routine is very heavily used in the network 77 * code and should be modified for each CPU to be as fast as possible. 78 */ 79 80union s_util { 81 char c[2]; 82 u_short s; 83}; 84 85union l_util { 86 u_int16_t s[2]; 87 u_int32_t l; 88}; 89 90union q_util { 91 u_int16_t s[4]; 92 u_int32_t l[2]; 93 u_int64_t q; 94}; 95 96#define ADDCARRY(x) do { if (x > 65535) { x -= 65535; } } while (0) 97 98#define REDUCE32 \ 99 { \ 100 q_util.q = sum; \ 101 sum = q_util.s[0] + q_util.s[1] + q_util.s[2] + q_util.s[3]; \ 102 } 103#define REDUCE16 \ 104 { \ 105 q_util.q = sum; \ 106 l_util.l = q_util.s[0] + q_util.s[1] + q_util.s[2] + q_util.s[3]; \ 107 sum = l_util.s[0] + l_util.s[1]; \ 108 ADDCARRY(sum); \ 109 } 110 111#define REDUCE {l_util.l = sum; sum = l_util.s[0] + l_util.s[1]; ADDCARRY(sum);} 112 113u_int16_t inet_cksum_simple(struct mbuf *, int); 114 115u_int16_t 116inet_cksum_simple(struct mbuf *m, int len) 117{ 118 return (inet_cksum(m, 0, 0, len)); 119} 120 121u_short 122in_addword(u_short a, u_short b) 123{ 124 union l_util l_util; 125 u_int32_t sum = a + b; 126 127 REDUCE; 128 return (sum); 129} 130 131u_short 132in_pseudo(u_int a, u_int b, u_int c) 133{ 134 u_int64_t sum; 135 union q_util q_util; 136 union l_util l_util; 137 138 sum = (u_int64_t) a + b + c; 139 REDUCE16; 140 return (sum); 141 142} 143 144#if defined(__arm__) 145 146extern int cpu_in_cksum(struct mbuf *m, int len, int off, uint32_t initial_sum); 147 148u_int16_t 149inet_cksum(struct mbuf *m, unsigned int nxt, unsigned int skip, 150 unsigned int len) 151{ 152 u_int32_t sum = 0; 153 154 /* sanity check */ 155 if ((m->m_flags & M_PKTHDR) && m->m_pkthdr.len < skip + len) { 156 panic("inet_cksum: mbuf len (%d) < off+len (%d+%d)\n", 157 m->m_pkthdr.len, skip, len); 158 } 159 160 /* include pseudo header checksum? */ 161 if (nxt != 0) { 162 struct ip *iph; 163 164 if (m->m_len < sizeof (struct ip)) 165 panic("inet_cksum: bad mbuf chain"); 166 167 iph = mtod(m, struct ip *); 168 sum = in_pseudo(iph->ip_src.s_addr, iph->ip_dst.s_addr, 169 htonl(len + nxt)); 170 } 171 172 return (cpu_in_cksum(m, len, skip, sum)); 173} 174 175#else 176 177u_int16_t 178inet_cksum(struct mbuf *m, unsigned int nxt, unsigned int skip, 179 unsigned int len) 180{ 181 u_short *w; 182 u_int32_t sum = 0; 183 int mlen = 0; 184 int byte_swapped = 0; 185 union s_util s_util; 186 union l_util l_util; 187 188 KERNEL_DEBUG(DBG_FNC_IN_CKSUM | DBG_FUNC_START, len,0,0,0,0); 189 190 /* sanity check */ 191 if ((m->m_flags & M_PKTHDR) && m->m_pkthdr.len < skip + len) { 192 panic("inet_cksum: mbuf len (%d) < off+len (%d+%d)\n", 193 m->m_pkthdr.len, skip, len); 194 } 195 196 /* include pseudo header checksum? */ 197 if (nxt != 0) { 198 struct ip *iph; 199 200 if (m->m_len < sizeof (struct ip)) 201 panic("inet_cksum: bad mbuf chain"); 202 203 iph = mtod(m, struct ip *); 204 sum = in_pseudo(iph->ip_src.s_addr, iph->ip_dst.s_addr, 205 htonl(len + nxt)); 206 } 207 208 if (skip != 0) { 209 for (; skip && m; m = m->m_next) { 210 if (m->m_len > skip) { 211 mlen = m->m_len - skip; 212 w = (u_short *)(void *)(m->m_data+skip); 213 goto skip_start; 214 } else { 215 skip -= m->m_len; 216 } 217 } 218 } 219 for (;m && len; m = m->m_next) { 220 if (m->m_len == 0) 221 continue; 222 w = mtod(m, u_short *); 223 224 if (mlen == -1) { 225 /* 226 * The first byte of this mbuf is the continuation 227 * of a word spanning between this mbuf and the 228 * last mbuf. 229 * 230 * s_util.c[0] is already saved when scanning previous 231 * mbuf. 232 */ 233 s_util.c[1] = *(char *)w; 234 sum += s_util.s; 235 w = (u_short *)(void *)((char *)w + 1); 236 mlen = m->m_len - 1; 237 len--; 238 } else { 239 mlen = m->m_len; 240 } 241skip_start: 242 if (len < mlen) 243 mlen = len; 244 245 len -= mlen; 246 /* 247 * Force to even boundary. 248 */ 249 if ((1 & (uintptr_t) w) && (mlen > 0)) { 250 REDUCE; 251 sum <<= 8; 252 s_util.c[0] = *(u_char *)w; 253 w = (u_short *)(void *)((char *)w + 1); 254 mlen--; 255 byte_swapped = 1; 256 } 257 /* 258 * Unroll the loop to make overhead from 259 * branches &c small. 260 */ 261 while ((mlen -= 32) >= 0) { 262 sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3]; 263 sum += w[4]; sum += w[5]; sum += w[6]; sum += w[7]; 264 sum += w[8]; sum += w[9]; sum += w[10]; sum += w[11]; 265 sum += w[12]; sum += w[13]; sum += w[14]; sum += w[15]; 266 w += 16; 267 } 268 mlen += 32; 269 while ((mlen -= 8) >= 0) { 270 sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3]; 271 w += 4; 272 } 273 mlen += 8; 274 if (mlen == 0 && byte_swapped == 0) 275 continue; 276 REDUCE; 277 while ((mlen -= 2) >= 0) { 278 sum += *w++; 279 } 280 if (byte_swapped) { 281 REDUCE; 282 sum <<= 8; 283 byte_swapped = 0; 284 if (mlen == -1) { 285 s_util.c[1] = *(char *)w; 286 sum += s_util.s; 287 mlen = 0; 288 } else 289 mlen = -1; 290 } else if (mlen == -1) 291 s_util.c[0] = *(char *)w; 292 } 293 if (len) 294 printf("cksum: out of data by %d\n", len); 295 if (mlen == -1) { 296 /* The last mbuf has odd # of bytes. Follow the 297 standard (the odd byte may be shifted left by 8 bits 298 or not as determined by endian-ness of the machine) */ 299 s_util.c[1] = 0; 300 sum += s_util.s; 301 } 302 REDUCE; 303 KERNEL_DEBUG(DBG_FNC_IN_CKSUM | DBG_FUNC_END, 0,0,0,0,0); 304 return (~sum & 0xffff); 305} 306 307#endif 308