xnu-7195.60.75.tar.gz

[apple/xnu.git] / bsd / netinet6 / in6_cksum.c

diff --git a/bsd/netinet6/in6_cksum.c b/bsd/netinet6/in6_cksum.c
index 2bea8cbcc7bf0a3adef902180160d53e296b4dda..41350d56057eddadc0a24829bd3e09a3b84bbee5 100644 (file)
--- a/bsd/netinet6/in6_cksum.c
+++ b/bsd/netinet6/in6_cksum.c
@@ -2,7 +2,7 @@
  * Copyright (c) 2009-2012 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
@@ -11,10 +11,10 @@
  * 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,
@@ -22,7 +22,7 @@
  * 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@
  */
 
@@ -149,8 +149,9 @@ in6_pseudo(const struct in6_addr *src, const struct in6_addr *dst, uint32_t x)
         */
        w = (const uint16_t *)src;
        sum += w[0];
-       if (!IN6_IS_SCOPE_EMBED(src))
+       if (!IN6_IS_SCOPE_EMBED(src)) {
                sum += w[1];
+       }
        sum += w[2]; sum += w[3]; sum += w[4]; sum += w[5];
        sum += w[6]; sum += w[7];
 
@@ -159,8 +160,9 @@ in6_pseudo(const struct in6_addr *src, const struct in6_addr *dst, uint32_t x)
         */
        w = (const uint16_t *)dst;
        sum += w[0];
-       if (!IN6_IS_SCOPE_EMBED(dst))
+       if (!IN6_IS_SCOPE_EMBED(dst)) {
                sum += w[1];
+       }
        sum += w[2]; sum += w[3]; sum += w[4]; sum += w[5];
        sum += w[6]; sum += w[7];
 
@@ -175,7 +177,7 @@ in6_pseudo(const struct in6_addr *src, const struct in6_addr *dst, uint32_t x)
        /* fold in carry bits */
        ADDCARRY(sum);
 
-       return (sum);
+       return (uint16_t)sum;
 }
 
 /*
@@ -193,7 +195,7 @@ inet6_cksum(struct mbuf *m, uint32_t nxt, uint32_t off, uint32_t len)
 
        if (nxt != 0) {
                struct ip6_hdr *ip6;
-               unsigned char buf[sizeof (*ip6)] __attribute__((aligned(8)));
+               unsigned char buf[sizeof(*ip6)] __attribute__((aligned(8)));
                uint32_t mlen;
 
                /*
@@ -203,7 +205,7 @@ inet6_cksum(struct mbuf *m, uint32_t nxt, uint32_t off, uint32_t len)
                 * the caller setting m_pkthdr.len correctly, if the mbuf is
                 * a M_PKTHDR one.
                 */
-               if ((mlen = m_length2(m, NULL)) < sizeof (*ip6)) {
+               if ((mlen = m_length2(m, NULL)) < sizeof(*ip6)) {
                        panic("%s: mbuf %p pkt too short (%d) for IPv6 header",
                            __func__, m, mlen);
                        /* NOTREACHED */
@@ -214,9 +216,9 @@ inet6_cksum(struct mbuf *m, uint32_t nxt, uint32_t off, uint32_t len)
                 * aligned, copy it to a local buffer.  Note here that we
                 * expect the data pointer to point to the IPv6 header.
                 */
-               if ((sizeof (*ip6) > m->m_len) ||
+               if ((sizeof(*ip6) > m->m_len) ||
                    !IP6_HDR_ALIGNED_P(mtod(m, caddr_t))) {
-                       m_copydata(m, 0, sizeof (*ip6), (caddr_t)buf);
+                       m_copydata(m, 0, sizeof(*ip6), (caddr_t)buf);
                        ip6 = (struct ip6_hdr *)(void *)buf;
                } else {
                        ip6 = (struct ip6_hdr *)(void *)(m->m_data);
@@ -230,5 +232,50 @@ inet6_cksum(struct mbuf *m, uint32_t nxt, uint32_t off, uint32_t len)
                ADDCARRY(sum);
        }
 
-       return (~sum & 0xffff);
+       return ~sum & 0xffff;
+}
+
+/*
+ * buffer MUST contain at least an IPv6 header, if nxt is specified;
+ * nxt is the upper layer protocol number;
+ * off is an offset where TCP/UDP/ICMP6 header starts;
+ * len is a total length of a transport segment (e.g. TCP header + TCP payload)
+ */
+u_int16_t
+inet6_cksum_buffer(const uint8_t *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);
+
+       if (nxt != 0) {
+               const struct ip6_hdr *ip6;
+               unsigned char buf[sizeof(*ip6)] __attribute__((aligned(8)));
+
+               /*
+                * In case the IPv6 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 IPv6 header.
+                */
+               if (!IP6_HDR_ALIGNED_P(buffer)) {
+                       memcpy(buf, buffer, sizeof(*ip6));
+                       ip6 = (const struct ip6_hdr *)(const void *)buf;
+               } else {
+                       ip6 = (const struct ip6_hdr *)buffer;
+               }
+
+               /* add pseudo header checksum */
+               sum += in6_pseudo(&ip6->ip6_src, &ip6->ip6_dst,
+                   htonl(nxt + len));
+
+               /* fold in carry bits */
+               ADDCARRY(sum);
+       }
+
+       return ~sum & 0xffff;
 }