/*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2012 Apple Inc. All rights reserved.
*
- * @APPLE_LICENSE_HEADER_START@
- *
- * Copyright (c) 1999-2003 Apple Computer, 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. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
+ * 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
* Please see the License for the specific language governing rights and
* limitations under the License.
*
- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
/*
* Copyright (c) 1988, 1992, 1993
*/
#include <sys/param.h>
+#include <machine/endian.h>
#include <sys/mbuf.h>
-#include <sys/kdebug.h>
-
-#define DBG_FNC_IN_CKSUM NETDBG_CODE(DBG_NETIP, (3 << 8))
+#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.
*/
-
-union s_util {
- char c[2];
- u_short s;
-};
+#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 {
- u_int16_t s[2];
- u_int32_t l;
+ uint16_t s[2];
+ uint32_t l;
};
union q_util {
- u_int16_t s[4];
- u_int32_t l[2];
- u_int64_t q;
-};
-
-#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); \
- }
-
-#define REDUCE {l_util.l = sum; sum = l_util.s[0] + l_util.s[1]; ADDCARRY(sum);}
-
-
-#if defined(ppc)
-
-__inline unsigned short
-in_addword(u_short a, u_short b)
-{
- union l_util l_util;
- u_int32_t sum = a + b;
- REDUCE;
- return (sum);
-}
+ uint16_t s[4];
+ uint32_t l[2];
+ uint64_t q;
+};
-__inline unsigned short
-in_pseudo(u_int a, u_int b, u_int c)
-{
- u_int64_t sum;
- union q_util q_util;
- union l_util l_util;
+#define PREDICT_FALSE(_exp) __builtin_expect((_exp), 0)
- sum = (u_int64_t) a + b + c;
- REDUCE16;
- return (sum);
+static uint16_t in_cksumdata(const void *buf, int len);
-}
+/*
+ * Portable version of 16-bit 1's complement sum function that works
+ * on a contiguous buffer. This is used mainly for instances where
+ * the caller is certain about the buffer requirements, e.g. for IP
+ * header checksum calculation, though it is capable of being used
+ * on any arbitrary data span. The platform-specific cpu_in_cksum()
+ * routine might be better-optmized, so use that instead for large
+ * data span.
+ *
+ * The logic is borrowed from <bsd/netinet/cpu_in_cksum.c>
+ */
-int
-in_cksum(m, len)
- register struct mbuf *m;
- register int len;
+#if ULONG_MAX == 0xffffffffUL
+/* 32-bit version */
+static uint16_t
+in_cksumdata(const void *buf, int mlen)
{
- register u_short *w;
- register int sum = 0;
- register int mlen = 0;
- int starting_on_odd = 0;
-
-
- KERNEL_DEBUG(DBG_FNC_IN_CKSUM | DBG_FUNC_START, len,0,0,0,0);
-
- for (;m && len; m = m->m_next) {
- if (m->m_len == 0)
- continue;
- mlen = m->m_len;
- w = mtod(m, u_short *);
-
- if (len < mlen)
- mlen = len;
-
- sum = xsum_assym(w, mlen, sum, starting_on_odd);
- len -= mlen;
- if (mlen & 0x1)
- {
- if (starting_on_odd)
- starting_on_odd = 0;
- else
- starting_on_odd = 1;
+ uint32_t sum, partial;
+ unsigned int final_acc;
+ uint8_t *data = (void *)buf;
+ boolean_t needs_swap, started_on_odd;
+
+ VERIFY(mlen >= 0);
+
+ needs_swap = FALSE;
+ started_on_odd = FALSE;
+
+ sum = 0;
+ 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
+ partial = *data;
+#endif
+ ++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 (PREDICT_FALSE(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
+ partial += *data << 8;
+#endif
+ started_on_odd = !started_on_odd;
+ }
- KERNEL_DEBUG(DBG_FNC_IN_CKSUM | DBG_FUNC_END, 0,0,0,0,0);
- return (~sum & 0xffff);
+ if (needs_swap)
+ partial = (partial << 8) + (partial >> 24);
+ sum += (partial >> 16) + (partial & 0xffff);
+ sum = (sum >> 16) + (sum & 0xffff);
+
+ final_acc = ((sum >> 16) & 0xffff) + (sum & 0xffff);
+ final_acc = (final_acc >> 16) + (final_acc & 0xffff);
+
+ return (final_acc);
}
-u_short
-in_cksum_skip(m, len, skip)
- register struct mbuf *m;
- register int len;
- register int skip;
+#else
+/* 64-bit version */
+static uint16_t
+in_cksumdata(const void *buf, int mlen)
{
- register u_short *w;
- register int sum = 0;
- register int mlen = 0;
- int starting_on_odd = 0;
-
- len -= skip;
- for (; skip && m; m = m->m_next) {
- if (m->m_len > skip) {
- mlen = m->m_len - skip;
- w = (u_short *)(m->m_data+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;
- w = mtod(m, u_short *);
-
-skip_start:
- if (len < mlen)
- mlen = len;
- sum = xsum_assym(w, mlen, sum, starting_on_odd);
- len -= mlen;
- if (mlen & 0x1)
- {
- if (starting_on_odd)
- starting_on_odd = 0;
- else
- starting_on_odd = 1;
+ uint64_t sum, partial;
+ unsigned int final_acc;
+ uint8_t *data = (void *)buf;
+ boolean_t needs_swap, started_on_odd;
+
+ VERIFY(mlen >= 0);
+
+ needs_swap = FALSE;
+ started_on_odd = FALSE;
+
+ sum = 0;
+ 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
+ partial = *data;
+#endif
+ ++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 (PREDICT_FALSE(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
+ partial += *data << 8;
+#endif
+ started_on_odd = !started_on_odd;
+ }
- return (~sum & 0xffff);
+ if (needs_swap)
+ partial = (partial << 8) + (partial >> 56);
+ sum += (partial >> 32) + (partial & 0xffffffff);
+ 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);
}
-#else
+#endif /* ULONG_MAX != 0xffffffffUL */
-u_short
-in_addword(u_short a, u_short b)
-{
- union l_util l_util;
- u_int32_t sum = a + b;
- REDUCE(sum);
- return (sum);
-}
+/*
+ * Perform 16-bit 1's complement sum on a contiguous span.
+ */
+uint16_t
+b_sum16(const void *buf, int len)
+{
+ return (in_cksumdata(buf, len));
+}
+
+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 (sum);
+}
-u_short
-in_pseudo(u_int a, u_int b, u_int c)
+uint16_t
+in_pseudo(uint32_t a, uint32_t b, uint32_t c)
{
- u_int64_t sum;
+ uint64_t sum;
union q_util q_util;
- union l_util l_util;
+ union l_util l_util;
- sum = (u_int64_t) a + b + c;
+ sum = (uint64_t)a + b + c;
REDUCE16;
return (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;
-int
-in_cksum(m, len)
- register struct mbuf *m;
- register int len;
+ sum = a + b + c;
+ REDUCE16;
+ return (sum);
+}
+
+/*
+ * May be used on IP header with options.
+ */
+uint16_t
+in_cksum_hdr_opt(const struct ip *ip)
{
- register u_short *w;
- register int sum = 0;
- register int mlen = 0;
- int byte_swapped = 0;
- union s_util s_util;
- union l_util l_util;
-
- KERNEL_DEBUG(DBG_FNC_IN_CKSUM | DBG_FUNC_START, len,0,0,0,0);
-
- for (;m && len; m = m->m_next) {
- if (m->m_len == 0)
- continue;
- w = mtod(m, u_short *);
- 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] = *(char *)w;
- sum += s_util.s;
- w = (u_short *)((char *)w + 1);
- mlen = m->m_len - 1;
- len--;
- } else
- mlen = m->m_len;
- if (len < mlen)
- mlen = len;
- len -= mlen;
- /*
- * Force to even boundary.
- */
- if ((1 & (int) w) && (mlen > 0)) {
- REDUCE;
- sum <<= 8;
- s_util.c[0] = *(u_char *)w;
- w = (u_short *)((char *)w + 1);
- mlen--;
- byte_swapped = 1;
- }
- /*
- * Unroll the loop to make overhead from
- * branches &c small.
- */
- while ((mlen -= 32) >= 0) {
- sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
- sum += w[4]; sum += w[5]; sum += w[6]; sum += w[7];
- sum += w[8]; sum += w[9]; sum += w[10]; sum += w[11];
- sum += w[12]; sum += w[13]; sum += w[14]; sum += w[15];
- w += 16;
- }
- mlen += 32;
- while ((mlen -= 8) >= 0) {
- sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
- w += 4;
- }
- mlen += 8;
- if (mlen == 0 && byte_swapped == 0)
- continue;
- REDUCE;
- while ((mlen -= 2) >= 0) {
- sum += *w++;
- }
- if (byte_swapped) {
- REDUCE;
- sum <<= 8;
- byte_swapped = 0;
- if (mlen == -1) {
- s_util.c[1] = *(char *)w;
- sum += s_util.s;
- mlen = 0;
- } else
- mlen = -1;
- } else if (mlen == -1)
- s_util.c[0] = *(char *)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;
+ 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;
}
- REDUCE;
- KERNEL_DEBUG(DBG_FNC_IN_CKSUM | DBG_FUNC_END, 0,0,0,0,0);
- return (~sum & 0xffff);
+
+ 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));
}
-int
-in_cksum_skip(m, len, skip)
- register struct mbuf *m;
- register u_short len;
- register u_short skip;
+/*
+ * 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)
{
- register u_short *w;
- register int sum = 0;
- register int mlen = 0;
- int byte_swapped = 0;
- union s_util s_util;
- union l_util l_util;
-
- KERNEL_DEBUG(DBG_FNC_IN_CKSUM | DBG_FUNC_START, len,0,0,0,0);
-
- len -= skip;
- for (; skip && m; m = m->m_next) {
- if (m->m_len > skip) {
- mlen = m->m_len - skip;
- w = (u_short *)(m->m_data+skip);
- goto skip_start;
- } else {
- skip -= m->m_len;
- }
- }
- for (;m && len; m = m->m_next) {
- if (m->m_len == 0)
- continue;
- w = mtod(m, u_short *);
-
- 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] = *(char *)w;
- sum += s_util.s;
- w = (u_short *)((char *)w + 1);
- mlen = m->m_len - 1;
- len--;
- } else {
- mlen = m->m_len;
- }
-skip_start:
- if (len < mlen)
- mlen = 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;
- len -= mlen;
/*
- * Force to even boundary.
+ * 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 ((1 & (int) w) && (mlen > 0)) {
- REDUCE;
- sum <<= 8;
- s_util.c[0] = *(u_char *)w;
- w = (u_short *)((char *)w + 1);
- mlen--;
- byte_swapped = 1;
+ if ((mlen = m_length2(m, NULL)) < sizeof (*ip)) {
+ panic("%s: mbuf %p too short (%d) for IPv4 header",
+ __func__, m, mlen);
+ /* NOTREACHED */
}
+
/*
- * Unroll the loop to make overhead from
- * branches &c small.
+ * 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.
*/
- while ((mlen -= 32) >= 0) {
- sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
- sum += w[4]; sum += w[5]; sum += w[6]; sum += w[7];
- sum += w[8]; sum += w[9]; sum += w[10]; sum += w[11];
- sum += w[12]; sum += w[13]; sum += w[14]; sum += w[15];
- w += 16;
- }
- mlen += 32;
- while ((mlen -= 8) >= 0) {
- sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
- w += 4;
- }
- mlen += 8;
- if (mlen == 0 && byte_swapped == 0)
- continue;
- REDUCE;
- while ((mlen -= 2) >= 0) {
- sum += *w++;
+ 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);
}
- if (byte_swapped) {
- REDUCE;
- sum <<= 8;
- byte_swapped = 0;
- if (mlen == -1) {
- s_util.c[1] = *(char *)w;
- sum += s_util.s;
- mlen = 0;
- } else
- mlen = -1;
- } else if (mlen == -1)
- s_util.c[0] = *(char *)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;
+
+ /* 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);
}
- REDUCE;
- KERNEL_DEBUG(DBG_FNC_IN_CKSUM | DBG_FUNC_END, 0,0,0,0,0);
+
return (~sum & 0xffff);
}
-
-#endif
projects / apple / xnu.git / blobdiff