in_cksum.c revision 330897
1274578Sngie/*- 2274578Sngie * SPDX-License-Identifier: BSD-3-Clause 3274578Sngie * 4274578Sngie * Copyright (c) 1990 The Regents of the University of California. 5274578Sngie * All rights reserved. 6274578Sngie * 7274578Sngie * Redistribution and use in source and binary forms, with or without 8274578Sngie * modification, are permitted provided that the following conditions 9274578Sngie * are met: 10274578Sngie * 1. Redistributions of source code must retain the above copyright 11274578Sngie * notice, this list of conditions and the following disclaimer. 12274578Sngie * 2. Redistributions in binary form must reproduce the above copyright 13274578Sngie * notice, this list of conditions and the following disclaimer in the 14274578Sngie * documentation and/or other materials provided with the distribution. 15274578Sngie * 4. Neither the name of the University nor the names of its contributors 16274578Sngie * may be used to endorse or promote products derived from this software 17274578Sngie * without specific prior written permission. 18274578Sngie * 19274578Sngie * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20274578Sngie * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21274578Sngie * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22274578Sngie * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23274578Sngie * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24274578Sngie * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25313535Sngie * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26274578Sngie * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27274578Sngie * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28274578Sngie * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29274578Sngie * SUCH DAMAGE. 30274578Sngie */ 31274578Sngie/*- 32274578Sngie * Copyright (c) 2001 by Thomas Moestl <tmm@FreeBSD.org>. 33274578Sngie * All rights reserved. 34274578Sngie * 35274578Sngie * Redistribution and use in source and binary forms, with or without 36274578Sngie * modification, are permitted provided that the following conditions 37274578Sngie * are met: 38274578Sngie * 1. Redistributions of source code must retain the above copyright 39274578Sngie * notice, this list of conditions and the following disclaimer. 40274578Sngie * 2. Redistributions in binary form must reproduce the above copyright 41274578Sngie * notice, this list of conditions and the following disclaimer in the 42274578Sngie * documentation and/or other materials provided with the distribution. 43274578Sngie * 44274578Sngie * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 45274578Sngie * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 46274578Sngie * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 47274578Sngie * IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 48274578Sngie * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 49274578Sngie * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 50274578Sngie * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 51274578Sngie * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 52274578Sngie * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE 53274578Sngie * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 54274578Sngie * 55274578Sngie * from tahoe: in_cksum.c 1.2 86/01/05 56 * from: @(#)in_cksum.c 1.3 (Berkeley) 1/19/91 57 * from: FreeBSD: src/sys/i386/i386/in_cksum.c,v 1.22 2000/11/25 58 */ 59 60#include <sys/cdefs.h> 61__FBSDID("$FreeBSD: stable/11/sys/sparc64/sparc64/in_cksum.c 330897 2018-03-14 03:19:51Z eadler $"); 62 63#include <sys/param.h> 64#include <sys/systm.h> 65#include <sys/mbuf.h> 66 67#include <netinet/in.h> 68#include <netinet/in_systm.h> 69#include <netinet/ip.h> 70 71#include <machine/in_cksum.h> 72 73/* 74 * Checksum routine for Internet Protocol family headers. 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 * This implementation is a sparc64 version. Most code was taken over 80 * and adapted from the i386. Some optimizations were changed to achieve 81 * (hopefully) better performance. 82 * This uses 64-bit loads, but 32-bit additions due to the lack of a 64-bit 83 * add-with-carry operation. 84 */ 85 86/* 87 * REDUCE() is actually not used that frequently... maybe a C implementation 88 * would suffice. 89 */ 90#define REDUCE(sum, tmp) __asm( \ 91 "sll %2, 16, %1\n" \ 92 "addcc %2, %1, %0\n" \ 93 "srl %0, 16, %0\n" \ 94 "addc %0, 0, %0" : "=r" (sum), "=&r" (tmp) : "0" (sum) : "cc") 95 96/* 97 * Note that some of these macros depend on the flags being preserved 98 * between calls, thus they have to be used within a single __asm(). 99 */ 100#define LD64_ADD32(n, mod) \ 101 "ldx [%3 + " #n "], %1\n" \ 102 "add" #mod " %2, %1, %0\n" \ 103 "srlx %1, 32, %1\n" \ 104 "addccc %0, %1, %0\n" 105 106#define LD32_ADD32(n, mod) \ 107 "lduw [%3 + " #n "], %1\n" \ 108 "add" #mod " %2, %1, %0\n" 109 110#define MOP(sum, tmp, addr) \ 111 "addc %2, 0, %0" \ 112 : "=r" (sum), "=&r" (tmp) : "0" (sum), "r" (addr) : "cc" 113 114u_short 115in_cksum_skip(struct mbuf *m, int len, int skip) 116{ 117 u_short *w; 118 unsigned long tmp, sum = 0; 119 int mlen = 0; 120 int byte_swapped = 0; 121 u_short su = 0; 122 123 len -= skip; 124 for (; skip > 0 && m != NULL; m = m->m_next) { 125 if (m->m_len > skip) { 126 mlen = m->m_len - skip; 127 w = (u_short *)(mtod(m, u_char *) + skip); 128 goto skip_start; 129 } else 130 skip -= m->m_len; 131 } 132 133 for (; m != NULL && len > 0; m = m->m_next) { 134 if (m->m_len == 0) 135 continue; 136 w = mtod(m, u_short *); 137 if (mlen == -1) { 138 /* 139 * The first byte of this mbuf is the continuation 140 * of a word spanning between this mbuf and the 141 * last mbuf. 142 * 143 * The high order byte of su is already saved when 144 * scanning previous mbuf. sum was REDUCEd when we 145 * found mlen == -1 146 */ 147 sum += su | *(u_char *)w; 148 w = (u_short *)((u_char *)w + 1); 149 mlen = m->m_len - 1; 150 len--; 151 } else 152 mlen = m->m_len; 153skip_start: 154 if (len < mlen) 155 mlen = len; 156 len -= mlen; 157 /* 158 * Force to a 8-byte boundary first so that we can use 159 * LD64_ADD32. 160 */ 161 if (((u_long)w & 7) != 0) { 162 REDUCE(sum, tmp); 163 if (((u_long)w & 1) != 0 && mlen >= 1) { 164 sum <<= 8; 165 su = *(u_char *)w << 8; 166 w = (u_short *)((u_char *)w + 1); 167 mlen--; 168 byte_swapped = 1; 169 } 170 if (((u_long)w & 2) != 0 && mlen >= 2) { 171 sum += *w++; 172 mlen -= 2; 173 } 174 if (((u_long)w & 4) != 0 && mlen >= 4) { 175 __asm( 176 LD32_ADD32(0, cc) 177 MOP(sum, tmp, w) 178 ); 179 w += 2; 180 mlen -= 4; 181 } 182 } 183 /* 184 * Do as much of the checksum as possible 64 bits at at time. 185 * In fact, this loop is unrolled to make overhead from 186 * branches &c small. 187 */ 188 for (; mlen >= 64; mlen -= 64) { 189 __asm( 190 LD64_ADD32(0, cc) 191 LD64_ADD32(8, ccc) 192 LD64_ADD32(16, ccc) 193 LD64_ADD32(24, ccc) 194 LD64_ADD32(32, ccc) 195 LD64_ADD32(40, ccc) 196 LD64_ADD32(48, ccc) 197 LD64_ADD32(56, ccc) 198 MOP(sum, tmp, w) 199 ); 200 w += 32; 201 } 202 if (mlen >= 32) { 203 __asm( 204 LD64_ADD32(0, cc) 205 LD64_ADD32(8, ccc) 206 LD64_ADD32(16, ccc) 207 LD64_ADD32(24, ccc) 208 MOP(sum, tmp, w) 209 ); 210 w += 16; 211 mlen -= 32; 212 } 213 if (mlen >= 16) { 214 __asm( 215 LD64_ADD32(0, cc) 216 LD64_ADD32(8, ccc) 217 MOP(sum, tmp, w) 218 ); 219 w += 8; 220 mlen -= 16; 221 } 222 if (mlen >= 8) { 223 __asm( 224 LD64_ADD32(0, cc) 225 MOP(sum, tmp, w) 226 ); 227 w += 4; 228 mlen -= 8; 229 } 230 REDUCE(sum, tmp); 231 while ((mlen -= 2) >= 0) 232 sum += *w++; 233 if (byte_swapped) { 234 sum <<= 8; 235 byte_swapped = 0; 236 if (mlen == -1) { 237 su |= *(u_char *)w; 238 sum += su; 239 mlen = 0; 240 } else 241 mlen = -1; 242 } else if (mlen == -1) { 243 /* 244 * This mbuf has odd number of bytes. 245 * There could be a word split between 246 * this mbuf and the next mbuf. 247 * Save the last byte (to prepend to next mbuf). 248 */ 249 su = *(u_char *)w << 8; 250 } 251 } 252 253 if (len) 254 printf("%s: out of data by %d\n", __func__, len); 255 if (mlen == -1) { 256 /* 257 * The last mbuf has odd # of bytes. Follow the 258 * standard (the odd byte is shifted left by 8 bits). 259 */ 260 sum += su & 0xff00; 261 } 262 REDUCE(sum, tmp); 263 return (~sum & 0xffff); 264} 265