From 2aff261d44fe933cf1c20b1fd093324c41cea4ba Mon Sep 17 00:00:00 2001
From: Florian Forster <octo@crystal.wlan.home.verplant.org>
Date: Wed, 7 Feb 2007 13:58:23 +0100
Subject: [PATCH] src/utils_dns.c: Fix the handling of the `struct udphdr'
 under the GNU libc and other systems.

---
 configure.in    | 15 +++++++++++++++
 src/utils_dns.c | 15 ++++++++++-----
 2 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/configure.in b/configure.in
index 760c9184..a15be257 100644
--- a/configure.in
+++ b/configure.in
@@ -452,6 +452,21 @@ AC_CHECK_MEMBERS([struct net_device_stats.rx_bytes, struct net_device_stats.tx_p
 	#include <linux/netdevice.h>
 	])
 
+#	[AC_DEFINE(HAVE_STRUCT_UDPHDR_BSD, 1, [Define if struct udphdr exists and is the BSD variant.])],
+AC_CHECK_MEMBERS([struct udphdr.uh_dport, struct udphdr.uh_sport],
+	[], [],
+	[
+	#include <sys/types.h>
+	#include <netinet/udp.h>
+	])
+#	[AC_DEFINE(HAVE_STRUCT_UDPHDR_GNU, 1, [Define if struct udphdr exists and is the GNU variant.])],
+AC_CHECK_MEMBERS([struct udphdr.dest, struct udphdr.source],
+	[], [],
+	[
+	#include <sys/types.h>
+	#include <netinet/udp.h>
+	])
+
 AC_MSG_CHECKING([for kernel type ($host_os)])
 case $host_os in
 	*linux*)
diff --git a/src/utils_dns.c b/src/utils_dns.c
index 89c03203..a6643bbf 100644
--- a/src/utils_dns.c
+++ b/src/utils_dns.c
@@ -110,9 +110,14 @@
 # define PPP_CONTROL_VAL 0x03	/* The control byte value */
 #endif
 
-#ifndef __FAVOR_BSD
-#define uh_sport source
-#define uh_dport dest
+#if HAVE_STRUCT_UDPHDR_UH_DPORT && HAVE_STRUCT_UDPHDR_UH_SPORT
+# define UDP_DEST uh_dport
+# define UDP_SRC  uh_dport
+#elif HAVE_STRUCT_UDPHDR_DEST && HAVE_STRUCT_UDPHDR_SOURCE
+# define UDP_DEST dest
+# define UDP_SRC  source
+#else
+# error "`struct udphdr' is unusable."
 #endif
 
 #include "utils_dns.h"
@@ -409,8 +414,8 @@ handle_udp(const struct udphdr *udp, int len,
 	const struct in6_addr *d_addr)
 {
     char buf[PCAP_SNAPLEN];
-    if ((ntohs (udp->uh_dport) != 53)
-		    && (ntohs (udp->uh_sport) != 53))
+    if ((ntohs (udp->UDP_DEST) != 53)
+		    && (ntohs (udp->UDP_SRC) != 53))
 	return 0;
     memcpy(buf, udp + 1, len - sizeof(*udp));
     if (0 == handle_dns(buf, len - sizeof(*udp), s_addr, d_addr))
-- 
2.30.2