Merge tcpdump 4.2.1.

MFC after:	2 weeks

1 files changed, 36 insertions, 3 deletions

diff --git a/contrib/tcpdump/tcpdump-stdinc.h b/contrib/tcpdump/tcpdump-stdinc.h
index c437cc1..d350d1b 100644
--- a/contrib/tcpdump/tcpdump-stdinc.h
+++ b/contrib/tcpdump/tcpdump-stdinc.h
@@ -131,10 +131,43 @@ typedef char* caddr_t;
 
 #endif /* WIN32 */
 
-#ifdef INET6
-#include "ip6.h"
+#ifndef HAVE___ATTRIBUTE__
+#define __attribute__(x)
 #endif
 
+/*
+ * Used to declare a structure unaligned, so that the C compiler,
+ * if necessary, generates code that doesn't assume alignment.
+ * This is required because there is no guarantee that the packet
+ * data we get from libpcap/WinPcap is properly aligned.
+ *
+ * This assumes that, for all compilers that support __attribute__:
+ *
+ *	1) they support __attribute__((packed));
+ *
+ *	2) for all instruction set architectures requiring strict
+ *	   alignment, declaring a structure with that attribute
+ *	   causes the compiler to generate code that handles
+ *	   misaligned 2-byte, 4-byte, and 8-byte integral
+ *	   quantities.
+ *
+ * It does not (yet) handle compilers where you can get the compiler
+ * to generate code of that sort by some other means.
+ *
+ * This is required in order to, for example, keep the compiler from
+ * generating, for
+ *
+ *	if (bp->bp_htype == 1 && bp->bp_hlen == 6 && bp->bp_op == BOOTPREQUEST) {
+ *
+ * in print-bootp.c, code that loads the first 4-byte word of a
+ * "struct bootp", masking out the bp_hops field, and comparing the result
+ * against 0x01010600.
+ *
+ * Note: this also requires that padding be put into the structure,
+ * at least for compilers where it's implemented as __attribute__((packed)).
+ */
+#define UNALIGNED	__attribute__((packed))
+
 #if defined(WIN32) || defined(MSDOS)
   #define FOPEN_READ_TXT   "rt"
   #define FOPEN_READ_BIN   "rb"
@@ -147,7 +180,7 @@ typedef char* caddr_t;
   #define FOPEN_WRITE_BIN  FOPEN_WRITE_TXT
 #endif
 
-#if defined(__GNUC__) && defined(__i386__) && !defined(__ntohl) 
+#if defined(__GNUC__) && defined(__i386__) && !defined(__APPLE__) && !defined(__ntohl) 
   #undef ntohl
   #undef ntohs
   #undef htonl