diff options
Diffstat (limited to 'sys/netinet/in_cksum.c')
| -rw-r--r-- | sys/netinet/in_cksum.c | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/sys/netinet/in_cksum.c b/sys/netinet/in_cksum.c new file mode 100644 index 000000000000..581950c8afa4 --- /dev/null +++ b/sys/netinet/in_cksum.c @@ -0,0 +1,257 @@ +/*- + * SPDX-License-Identifier: BSD-4-Clause + * + * Copyright (c) 1988, 1992, 1993 + * The Regents of the University of California. All rights reserved. + * Copyright (c) 1996 + * Matt Thomas <matt@3am-software.com> + * + * 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/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/param.h> +#include <sys/mbuf.h> +#include <sys/systm.h> +#include <netinet/in_systm.h> +#include <netinet/in.h> +#include <netinet/ip.h> +#include <machine/in_cksum.h> + +/* + * These implementations may be overridden on a per-platform basis. + */ +#ifndef HAVE_MD_IN_CKSUM + +/* + * Checksum routine for Internet Protocol family headers + * (Portable Alpha version). + * + * This routine is very heavily used in the network + * code and should be modified for each CPU to be as fast as possible. + */ + +#define ADDCARRY(x) (x > 65535 ? x -= 65535 : x) +#define REDUCE32 \ + { \ + q_util.q = sum; \ + sum = q_util.s[0] + q_util.s[1] + q_util.s[2] + q_util.s[3]; \ + } +#define REDUCE16 \ + { \ + q_util.q = sum; \ + l_util.l = q_util.s[0] + q_util.s[1] + q_util.s[2] + q_util.s[3]; \ + sum = l_util.s[0] + l_util.s[1]; \ + ADDCARRY(sum); \ + } + +static const u_int32_t in_masks[] = { +#if _BYTE_ORDER == _LITTLE_ENDIAN + /*0 bytes*/ /*1 byte*/ /*2 bytes*/ /*3 bytes*/ + 0x00000000, 0x000000FF, 0x0000FFFF, 0x00FFFFFF, /* offset 0 */ + 0x00000000, 0x0000FF00, 0x00FFFF00, 0xFFFFFF00, /* offset 1 */ + 0x00000000, 0x00FF0000, 0xFFFF0000, 0xFFFF0000, /* offset 2 */ + 0x00000000, 0xFF000000, 0xFF000000, 0xFF000000, /* offset 3 */ +#else + /*0 bytes*/ /*1 byte*/ /*2 bytes*/ /*3 bytes*/ + 0x00000000, 0xFF000000, 0xFFFF0000, 0xFFFFFF00, /* offset 0 */ + 0x00000000, 0x00FF0000, 0x00FFFF00, 0x00FFFFFF, /* offset 1 */ + 0x00000000, 0x0000FF00, 0x0000FFFF, 0x0000FFFF, /* offset 2 */ + 0x00000000, 0x000000FF, 0x000000FF, 0x000000FF, /* offset 3 */ +#endif +}; + +union l_util { + u_int16_t s[2]; + u_int32_t l; +}; +union q_util { + u_int16_t s[4]; + u_int32_t l[2]; + u_int64_t q; +}; + +static u_int64_t +in_cksumdata(const void *buf, int len) +{ + const u_int32_t *lw = (const u_int32_t *) buf; + u_int64_t sum = 0; + u_int64_t prefilled; + int offset; + union q_util q_util; + + if ((3 & (long) lw) == 0 && len == 20) { + sum = (u_int64_t) lw[0] + lw[1] + lw[2] + lw[3] + lw[4]; + REDUCE32; + return sum; + } + + if ((offset = 3 & (long) lw) != 0) { + const u_int32_t *masks = in_masks + (offset << 2); + lw = (u_int32_t *) (((long) lw) - offset); + sum = *lw++ & masks[len >= 3 ? 3 : len]; + len -= 4 - offset; + if (len <= 0) { + REDUCE32; + return sum; + } + } +#if 0 + /* + * Force to cache line boundary. + */ + offset = 32 - (0x1f & (long) lw); + if (offset < 32 && len > offset) { + len -= offset; + if (4 & offset) { + sum += (u_int64_t) lw[0]; + lw += 1; + } + if (8 & offset) { + sum += (u_int64_t) lw[0] + lw[1]; + lw += 2; + } + if (16 & offset) { + sum += (u_int64_t) lw[0] + lw[1] + lw[2] + lw[3]; + lw += 4; + } + } +#endif + /* + * access prefilling to start load of next cache line. + * then add current cache line + * save result of prefilling for loop iteration. + */ + prefilled = lw[0]; + while ((len -= 32) >= 4) { + u_int64_t prefilling = lw[8]; + sum += prefilled + lw[1] + lw[2] + lw[3] + + lw[4] + lw[5] + lw[6] + lw[7]; + lw += 8; + prefilled = prefilling; + } + if (len >= 0) { + sum += prefilled + lw[1] + lw[2] + lw[3] + + lw[4] + lw[5] + lw[6] + lw[7]; + lw += 8; + } else { + len += 32; + } + while ((len -= 16) >= 0) { + sum += (u_int64_t) lw[0] + lw[1] + lw[2] + lw[3]; + lw += 4; + } + len += 16; + while ((len -= 4) >= 0) { + sum += (u_int64_t) *lw++; + } + len += 4; + if (len > 0) + sum += (u_int64_t) (in_masks[len] & *lw); + REDUCE32; + return sum; +} + +u_short +in_addword(u_short a, u_short b) +{ + u_int64_t sum = a + b; + + ADDCARRY(sum); + return (sum); +} + +u_short +in_pseudo(u_int32_t a, u_int32_t b, u_int32_t c) +{ + u_int64_t sum; + union q_util q_util; + union l_util l_util; + + sum = (u_int64_t) a + b + c; + REDUCE16; + return (sum); +} + +u_short +in_cksum_skip(struct mbuf *m, int len, int skip) +{ + u_int64_t sum = 0; + int mlen = 0; + int clen = 0; + caddr_t addr; + union q_util q_util; + union l_util l_util; + + len -= skip; + for (; skip && m; m = m->m_next) { + if (m->m_len > skip) { + mlen = m->m_len - skip; + addr = mtod(m, caddr_t) + skip; + goto skip_start; + } else { + skip -= m->m_len; + } + } + + for (; m && len; m = m->m_next) { + if (m->m_len == 0) + continue; + mlen = m->m_len; + addr = mtod(m, caddr_t); +skip_start: + if (len < mlen) + mlen = len; + + if ((clen ^ (uintptr_t) addr) & 1) + sum += in_cksumdata(addr, mlen) << 8; + else + sum += in_cksumdata(addr, mlen); + + clen += mlen; + len -= mlen; + } + REDUCE16; + return (~sum & 0xffff); +} + +u_int in_cksum_hdr(const struct ip *ip) +{ + u_int64_t sum = in_cksumdata(ip, sizeof(struct ip)); + union q_util q_util; + union l_util l_util; + REDUCE16; + return (~sum & 0xffff); +} + +#endif /* !HAVE_MD_IN_CKSUM */ |