/* $OpenBSD: in_cksum.c,v 1.11 2022/02/01 15:30:10 miod Exp $ */ /* $NetBSD: in_cksum.c,v 1.7 2003/07/15 02:54:48 lukem Exp $ */ /* * Copyright 2001 Wasabi Systems, Inc. * All rights reserved. * * Written by Simon Burge and Eduardo Horvath for Wasabi Systems, Inc. * * 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 for the NetBSD Project by * Wasabi Systems, Inc. * 4. The name of Wasabi Systems, Inc. may not be used to endorse * or promote products derived from this software without specific prior * written permission. * * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``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 WASABI SYSTEMS, INC * 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. */ #include <sys/param.h> #include <sys/systm.h> #include <sys/mbuf.h> #include <sys/socketvar.h> #include <netinet/in.h> #include <netinet/ip.h> #include <netinet/ip_var.h> /* * Checksum routine for Internet Protocol family headers. * * This routine is very heavily used in the network * code and should be modified for each CPU to be as fast as possible. * * PowerPC version. */ #define REDUCE1 sum = (sum & 0xffff) + (sum >> 16) /* Two REDUCE1s is faster than REDUCE1; if (sum > 65535) sum -= 65536; */ #define REDUCE { REDUCE1; REDUCE1; } static __inline__ int in_cksum_internal(struct mbuf *m, int off, int len, u_int sum) { uint8_t *w; int mlen = 0; int byte_swapped = 0; int n; union { uint8_t c[2]; uint16_t s; } s_util; for (;m && len; m = m->m_next) { if (m->m_len == 0) continue; w = mtod(m, uint8_t *) + off; /* * 'off' can only be non-zero on the first pass of this * loop when mlen != -1, so we don't need to worry about * 'off' in the if clause below. */ 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] = *w++; sum += s_util.s; mlen = m->m_len - 1; len--; } else { mlen = m->m_len - off; off = 0; } if (len < mlen) mlen = len; len -= mlen; /* * Force to a word boundary. */ if ((3 & (long) w) && (mlen > 0)) { if ((1 & (long) w)) { REDUCE; sum <<= 8; s_util.c[0] = *w++; mlen--; byte_swapped = 1; } if ((2 & (long) w) && (mlen > 1)) { /* * Since the `sum' may contain full 32 bit * value, we can't simply add any value. */ __asm volatile( "lhz 7,0(%1);" /* load current data half word */ "addc %0,%0,7;" /* add to sum */ "addze %0,%0;" /* add carry bit */ : "+r"(sum) : "b"(w) : "7"); /* clobber r7 */ w += 2; mlen -= 2; } } if (mlen >= 64) { n = mlen >> 6; __asm volatile( "addic 0,0,0;" /* clear carry */ "mtctr %1;" /* load loop count */ "1:" "lwz 7,4(%2);" /* load current data word */ "lwz 8,8(%2);" "lwz 9,12(%2);" "lwz 10,16(%2);" "adde %0,%0,7;" /* add to sum */ "adde %0,%0,8;" "adde %0,%0,9;" "adde %0,%0,10;" "lwz 7,20(%2);" "lwz 8,24(%2);" "lwz 9,28(%2);" "lwz 10,32(%2);" "adde %0,%0,7;" "adde %0,%0,8;" "adde %0,%0,9;" "adde %0,%0,10;" "lwz 7,36(%2);" "lwz 8,40(%2);" "lwz 9,44(%2);" "lwz 10,48(%2);" "adde %0,%0,7;" "adde %0,%0,8;" "adde %0,%0,9;" "adde %0,%0,10;" "lwz 7,52(%2);" "lwz 8,56(%2);" "lwz 9,60(%2);" "lwzu 10,64(%2);" "adde %0,%0,7;" "adde %0,%0,8;" "adde %0,%0,9;" "adde %0,%0,10;" "bdnz 1b;" /* loop */ "addze %0,%0;" /* add carry bit */ : "+r"(sum) : "r"(n), "b"(w - 4) : "7", "8", "9", "10"); /* clobber r7, r8, r9, r10 */ w += n * 64; mlen -= n * 64; } if (mlen >= 8) { n = mlen >> 3; __asm volatile( "addic 0,0,0;" /* clear carry */ "mtctr %1;" /* load loop count */ "1:" "lwz 7,4(%2);" /* load current data word */ "lwzu 8,8(%2);" "adde %0,%0,7;" /* add to sum */ "adde %0,%0,8;" "bdnz 1b;" /* loop */ "addze %0,%0;" /* add carry bit */ : "+r"(sum) : "r"(n), "b"(w - 4) : "7", "8"); /* clobber r7, r8 */ w += n * 8; mlen -= n * 8; } if (mlen == 0 && byte_swapped == 0) continue; REDUCE; while ((mlen -= 2) >= 0) { sum += *(uint16_t *)w; w += 2; } if (byte_swapped) { REDUCE; sum <<= 8; byte_swapped = 0; if (mlen == -1) { s_util.c[1] = *w; sum += s_util.s; mlen = 0; } else mlen = -1; } else if (mlen == -1) s_util.c[0] = *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; return (~sum & 0xffff); } int in_cksum(struct mbuf *m, int len) { return (in_cksum_internal(m, 0, len, 0)); } int in4_cksum(struct mbuf *m, uint8_t nxt, int off, int len) { uint16_t *w; u_int sum = 0; union { struct ipovly ipov; u_int16_t w[10]; } u; if (nxt != 0) { /* pseudo header */ u.ipov.ih_x1[8] = 0; u.ipov.ih_pr = nxt; u.ipov.ih_len = htons(len); u.ipov.ih_src = mtod(m, struct ip *)->ip_src; u.ipov.ih_dst = mtod(m, struct ip *)->ip_dst; w = u.w; /* assumes sizeof(ipov) == 20 and first 8 bytes are zeroes */ sum += w[4]; sum += w[5]; sum += w[6]; sum += w[7]; sum += w[8]; sum += w[9]; } /* skip unnecessary part */ while (m && off > 0) { if (m->m_len > off) break; off -= m->m_len; m = m->m_next; } return (in_cksum_internal(m, off, len, sum)); }
