gems-kernel/source/THIRDPARTY/xnu/bsd/netinet/in_cksum.c
2024-06-03 11:29:39 -05:00

639 lines
17 KiB
C

/*
* Copyright (c) 2000-2017 Apple Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. The rights granted to you under the License
* may not be used to create, or enable the creation or redistribution of,
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
*
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
*
* The 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, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_OSREFERENCE_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 <machine/endian.h>
#include <sys/mbuf.h>
#include <kern/debug.h>
#include <net/dlil.h>
#include <netinet/in.h>
#define _IP_VHL
#include <netinet/ip.h>
#include <netinet/ip_var.h>
/*
* 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.
*/
#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); \
}
union l_util {
uint16_t s[2];
uint32_t l;
};
union q_util {
uint16_t s[4];
uint32_t l[2];
uint64_t q;
};
extern uint32_t os_cpu_in_cksum(const void *, uint32_t, uint32_t);
/*
* Perform 16-bit 1's complement sum on a contiguous span.
*/
uint16_t
b_sum16(const void *buf, int len)
{
return (uint16_t)os_cpu_in_cksum(buf, len, 0);
}
uint16_t inet_cksum_simple(struct mbuf *, int);
/*
* For the exported _in_cksum symbol in BSDKernel symbol set.
*/
uint16_t
inet_cksum_simple(struct mbuf *m, int len)
{
return inet_cksum(m, 0, 0, len);
}
uint16_t
in_addword(uint16_t a, uint16_t b)
{
uint64_t sum = a + b;
ADDCARRY(sum);
return (uint16_t)sum;
}
uint16_t
in_pseudo(uint32_t a, uint32_t b, uint32_t c)
{
uint64_t sum;
union q_util q_util;
union l_util l_util;
sum = (uint64_t)a + b + c;
REDUCE16;
return (uint16_t)sum;
}
uint16_t
in_pseudo64(uint64_t a, uint64_t b, uint64_t c)
{
uint64_t sum;
union q_util q_util;
union l_util l_util;
sum = a + b + c;
REDUCE16;
return (uint16_t)sum;
}
/*
* May be used on IP header with options.
*/
uint16_t
in_cksum_hdr_opt(const struct ip *ip)
{
return ~b_sum16(ip, (IP_VHL_HL(ip->ip_vhl) << 2)) & 0xffff;
}
/*
* A wrapper around the simple in_cksum_hdr() and the more complicated
* inet_cksum(); the former is chosen if the IP header is simple,
* contiguous and 32-bit aligned. Also does some stats accounting.
*/
uint16_t
ip_cksum_hdr_dir(struct mbuf *m, uint32_t hlen, int out)
{
struct ip *ip = mtod(m, struct ip *);
if (out) {
ipstat.ips_snd_swcsum++;
ipstat.ips_snd_swcsum_bytes += hlen;
} else {
ipstat.ips_rcv_swcsum++;
ipstat.ips_rcv_swcsum_bytes += hlen;
}
if (hlen == sizeof(*ip) &&
m->m_len >= sizeof(*ip) && IP_HDR_ALIGNED_P(ip)) {
return in_cksum_hdr(ip);
}
return inet_cksum(m, 0, 0, hlen);
}
uint16_t
ip_cksum_hdr_dir_buffer(const void *buffer, uint32_t hlen, uint32_t len,
int out)
{
const struct ip *ip = buffer;
if (out) {
ipstat.ips_snd_swcsum++;
ipstat.ips_snd_swcsum_bytes += hlen;
} else {
ipstat.ips_rcv_swcsum++;
ipstat.ips_rcv_swcsum_bytes += hlen;
}
if (hlen == sizeof(*ip) &&
len >= sizeof(*ip) && IP_HDR_ALIGNED_P(ip)) {
return in_cksum_hdr(ip);
}
return inet_cksum_buffer(buffer, 0, 0, hlen);
}
/*
* m MUST contain at least an IP header, if nxt is specified;
* nxt is the upper layer protocol number;
* off is an offset where TCP/UDP/ICMP header starts;
* len is a total length of a transport segment (e.g. TCP header + TCP payload)
*/
uint16_t
inet_cksum(struct mbuf *m, uint32_t nxt, uint32_t off, uint32_t len)
{
uint32_t sum;
sum = m_sum16(m, off, len);
/* include pseudo header checksum? */
if (nxt != 0) {
struct ip *ip;
unsigned char buf[sizeof((*ip))] __attribute__((aligned(8)));
uint32_t mlen;
/*
* Sanity check
*
* Use m_length2() instead of m_length(), as we cannot rely on
* the caller setting m_pkthdr.len correctly, if the mbuf is
* a M_PKTHDR one.
*/
if ((mlen = m_length2(m, NULL)) < sizeof(*ip)) {
panic("%s: mbuf %p too short (%d) for IPv4 header",
__func__, m, mlen);
/* NOTREACHED */
}
/*
* In case the IP header is not contiguous, or not 32-bit
* aligned, copy it to a local buffer. Note here that we
* expect the data pointer to point to the IP header.
*/
if ((sizeof(*ip) > m->m_len) ||
!IP_HDR_ALIGNED_P(mtod(m, caddr_t))) {
m_copydata(m, 0, sizeof(*ip), (caddr_t)buf);
ip = (struct ip *)(void *)buf;
} else {
ip = (struct ip *)(void *)(m->m_data);
}
/* add pseudo header checksum */
sum += in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
htonl(len + nxt));
/* fold in carry bits */
ADDCARRY(sum);
}
return ~sum & 0xffff;
}
/*
* buffer MUST contain at least an IP header, if nxt is specified;
* nxt is the upper layer protocol number;
* off is an offset where TCP/UDP/ICMP header starts;
* len is a total length of a transport segment (e.g. TCP header + TCP payload)
*/
uint16_t
inet_cksum_buffer(const void *buffer, uint32_t nxt, uint32_t off,
uint32_t len)
{
uint32_t sum;
if (off >= len) {
panic("%s: off (%d) >= len (%d)", __func__, off, len);
}
sum = b_sum16(&((const uint8_t *)buffer)[off], len);
/* include pseudo header checksum? */
if (nxt != 0) {
const struct ip *ip;
unsigned char buf[sizeof((*ip))] __attribute__((aligned(8)));
/*
* In case the IP header is not contiguous, or not 32-bit
* aligned, copy it to a local buffer. Note here that we
* expect the data pointer to point to the IP header.
*/
if (!IP_HDR_ALIGNED_P(buffer)) {
memcpy(buf, buffer, sizeof(*ip));
ip = (const struct ip *)(const void *)buf;
} else {
ip = (const struct ip *)buffer;
}
/* add pseudo header checksum */
sum += in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
htonl(len + nxt));
/* fold in carry bits */
ADDCARRY(sum);
}
return ~sum & 0xffff;
}
#if DEBUG || DEVELOPMENT
#include <pexpert/pexpert.h>
#define CKSUM_ERR kprintf
/*
* The following routines implement the portable, reference implementation
* of os_cpu_in_cksum_mbuf(). This is currently used only for validating
* the correctness of the platform-specific implementation, at boot time
* in dlil_verify_sum16(). It returns the 32-bit accumulator without doing
* a 1's complement on it.
*/
#if !defined(__LP64__)
/* 32-bit version */
uint32_t
in_cksum_mbuf_ref(struct mbuf *m, int len, int off, uint32_t initial_sum)
{
int mlen;
uint32_t sum, partial;
unsigned int final_acc;
uint8_t *data;
boolean_t needs_swap, started_on_odd;
VERIFY(len >= 0);
VERIFY(off >= 0);
needs_swap = FALSE;
started_on_odd = FALSE;
sum = (initial_sum >> 16) + (initial_sum & 0xffff);
for (;;) {
if (__improbable(m == NULL)) {
CKSUM_ERR("%s: out of data\n", __func__);
return (uint32_t)-1;
}
mlen = m->m_len;
if (mlen > off) {
mlen -= off;
data = mtod(m, uint8_t *) + off;
goto post_initial_offset;
}
off -= mlen;
if (len == 0) {
break;
}
m = m->m_next;
}
for (; len > 0; m = m->m_next) {
if (__improbable(m == NULL)) {
CKSUM_ERR("%s: out of data\n", __func__);
return (uint32_t)-1;
}
mlen = m->m_len;
data = mtod(m, uint8_t *);
post_initial_offset:
if (mlen == 0) {
continue;
}
if (mlen > len) {
mlen = len;
}
len -= mlen;
partial = 0;
if ((uintptr_t)data & 1) {
/* Align on word boundary */
started_on_odd = !started_on_odd;
#if BYTE_ORDER == LITTLE_ENDIAN
partial = *data << 8;
#else /* BYTE_ORDER != LITTLE_ENDIAN */
partial = *data;
#endif /* BYTE_ORDER != LITTLE_ENDIAN */
++data;
--mlen;
}
needs_swap = started_on_odd;
while (mlen >= 32) {
__builtin_prefetch(data + 32);
partial += *(uint16_t *)(void *)data;
partial += *(uint16_t *)(void *)(data + 2);
partial += *(uint16_t *)(void *)(data + 4);
partial += *(uint16_t *)(void *)(data + 6);
partial += *(uint16_t *)(void *)(data + 8);
partial += *(uint16_t *)(void *)(data + 10);
partial += *(uint16_t *)(void *)(data + 12);
partial += *(uint16_t *)(void *)(data + 14);
partial += *(uint16_t *)(void *)(data + 16);
partial += *(uint16_t *)(void *)(data + 18);
partial += *(uint16_t *)(void *)(data + 20);
partial += *(uint16_t *)(void *)(data + 22);
partial += *(uint16_t *)(void *)(data + 24);
partial += *(uint16_t *)(void *)(data + 26);
partial += *(uint16_t *)(void *)(data + 28);
partial += *(uint16_t *)(void *)(data + 30);
data += 32;
mlen -= 32;
if (__improbable(partial & 0xc0000000)) {
if (needs_swap) {
partial = (partial << 8) +
(partial >> 24);
}
sum += (partial >> 16);
sum += (partial & 0xffff);
partial = 0;
}
}
if (mlen & 16) {
partial += *(uint16_t *)(void *)data;
partial += *(uint16_t *)(void *)(data + 2);
partial += *(uint16_t *)(void *)(data + 4);
partial += *(uint16_t *)(void *)(data + 6);
partial += *(uint16_t *)(void *)(data + 8);
partial += *(uint16_t *)(void *)(data + 10);
partial += *(uint16_t *)(void *)(data + 12);
partial += *(uint16_t *)(void *)(data + 14);
data += 16;
mlen -= 16;
}
/*
* mlen is not updated below as the remaining tests
* are using bit masks, which are not affected.
*/
if (mlen & 8) {
partial += *(uint16_t *)(void *)data;
partial += *(uint16_t *)(void *)(data + 2);
partial += *(uint16_t *)(void *)(data + 4);
partial += *(uint16_t *)(void *)(data + 6);
data += 8;
}
if (mlen & 4) {
partial += *(uint16_t *)(void *)data;
partial += *(uint16_t *)(void *)(data + 2);
data += 4;
}
if (mlen & 2) {
partial += *(uint16_t *)(void *)data;
data += 2;
}
if (mlen & 1) {
#if BYTE_ORDER == LITTLE_ENDIAN
partial += *data;
#else /* BYTE_ORDER != LITTLE_ENDIAN */
partial += *data << 8;
#endif /* BYTE_ORDER != LITTLE_ENDIAN */
started_on_odd = !started_on_odd;
}
if (needs_swap) {
partial = (partial << 8) + (partial >> 24);
}
sum += (partial >> 16) + (partial & 0xffff);
/*
* Reduce sum to allow potential byte swap
* in the next iteration without carry.
*/
sum = (sum >> 16) + (sum & 0xffff);
}
final_acc = ((sum >> 16) & 0xffff) + (sum & 0xffff);
final_acc = (final_acc >> 16) + (final_acc & 0xffff);
return final_acc & 0xffff;
}
#else /* __LP64__ */
/* 64-bit version */
uint32_t
in_cksum_mbuf_ref(struct mbuf *m, int len, int off, uint32_t initial_sum)
{
int mlen;
uint64_t sum, partial;
unsigned int final_acc;
uint8_t *data;
boolean_t needs_swap, started_on_odd;
VERIFY(len >= 0);
VERIFY(off >= 0);
needs_swap = FALSE;
started_on_odd = FALSE;
sum = initial_sum;
for (;;) {
if (__improbable(m == NULL)) {
CKSUM_ERR("%s: out of data\n", __func__);
return (uint32_t)-1;
}
mlen = m->m_len;
if (mlen > off) {
mlen -= off;
data = mtod(m, uint8_t *) + off;
goto post_initial_offset;
}
off -= mlen;
if (len == 0) {
break;
}
m = m->m_next;
}
for (; len > 0; m = m->m_next) {
if (__improbable(m == NULL)) {
CKSUM_ERR("%s: out of data\n", __func__);
return (uint32_t)-1;
}
mlen = m->m_len;
data = mtod(m, uint8_t *);
post_initial_offset:
if (mlen == 0) {
continue;
}
if (mlen > len) {
mlen = len;
}
len -= mlen;
partial = 0;
if ((uintptr_t)data & 1) {
/* Align on word boundary */
started_on_odd = !started_on_odd;
#if BYTE_ORDER == LITTLE_ENDIAN
partial = *data << 8;
#else /* BYTE_ORDER != LITTLE_ENDIAN */
partial = *data;
#endif /* BYTE_ORDER != LITTLE_ENDIAN */
++data;
--mlen;
}
needs_swap = started_on_odd;
if ((uintptr_t)data & 2) {
if (mlen < 2) {
goto trailing_bytes;
}
partial += *(uint16_t *)(void *)data;
data += 2;
mlen -= 2;
}
while (mlen >= 64) {
__builtin_prefetch(data + 32);
__builtin_prefetch(data + 64);
partial += *(uint32_t *)(void *)data;
partial += *(uint32_t *)(void *)(data + 4);
partial += *(uint32_t *)(void *)(data + 8);
partial += *(uint32_t *)(void *)(data + 12);
partial += *(uint32_t *)(void *)(data + 16);
partial += *(uint32_t *)(void *)(data + 20);
partial += *(uint32_t *)(void *)(data + 24);
partial += *(uint32_t *)(void *)(data + 28);
partial += *(uint32_t *)(void *)(data + 32);
partial += *(uint32_t *)(void *)(data + 36);
partial += *(uint32_t *)(void *)(data + 40);
partial += *(uint32_t *)(void *)(data + 44);
partial += *(uint32_t *)(void *)(data + 48);
partial += *(uint32_t *)(void *)(data + 52);
partial += *(uint32_t *)(void *)(data + 56);
partial += *(uint32_t *)(void *)(data + 60);
data += 64;
mlen -= 64;
if (__improbable(partial & (3ULL << 62))) {
if (needs_swap) {
partial = (partial << 8) +
(partial >> 56);
}
sum += (partial >> 32);
sum += (partial & 0xffffffff);
partial = 0;
}
}
/*
* mlen is not updated below as the remaining tests
* are using bit masks, which are not affected.
*/
if (mlen & 32) {
partial += *(uint32_t *)(void *)data;
partial += *(uint32_t *)(void *)(data + 4);
partial += *(uint32_t *)(void *)(data + 8);
partial += *(uint32_t *)(void *)(data + 12);
partial += *(uint32_t *)(void *)(data + 16);
partial += *(uint32_t *)(void *)(data + 20);
partial += *(uint32_t *)(void *)(data + 24);
partial += *(uint32_t *)(void *)(data + 28);
data += 32;
}
if (mlen & 16) {
partial += *(uint32_t *)(void *)data;
partial += *(uint32_t *)(void *)(data + 4);
partial += *(uint32_t *)(void *)(data + 8);
partial += *(uint32_t *)(void *)(data + 12);
data += 16;
}
if (mlen & 8) {
partial += *(uint32_t *)(void *)data;
partial += *(uint32_t *)(void *)(data + 4);
data += 8;
}
if (mlen & 4) {
partial += *(uint32_t *)(void *)data;
data += 4;
}
if (mlen & 2) {
partial += *(uint16_t *)(void *)data;
data += 2;
}
trailing_bytes:
if (mlen & 1) {
#if BYTE_ORDER == LITTLE_ENDIAN
partial += *data;
#else /* BYTE_ORDER != LITTLE_ENDIAN */
partial += *data << 8;
#endif /* BYTE_ORDER != LITTLE_ENDIAN */
started_on_odd = !started_on_odd;
}
if (needs_swap) {
partial = (partial << 8) + (partial >> 56);
}
sum += (partial >> 32) + (partial & 0xffffffff);
/*
* Reduce sum to allow potential byte swap
* in the next iteration without carry.
*/
sum = (sum >> 32) + (sum & 0xffffffff);
}
final_acc = (sum >> 48) + ((sum >> 32) & 0xffff) +
((sum >> 16) & 0xffff) + (sum & 0xffff);
final_acc = (final_acc >> 16) + (final_acc & 0xffff);
final_acc = (final_acc >> 16) + (final_acc & 0xffff);
return final_acc & 0xffff;
}
#endif /* __LP64 */
#endif /* DEBUG || DEVELOPMENT */