Allow VLAN hack to be disabled at compile

config.h.in

@@ -8,6 +8,7 @@
 #define USE_PCRE                     @USE_PCRE@
 #define USE_IPv6                     @USE_IPv6@
 #define USE_TCPKILL                  @USE_TCPKILL@
+#define USE_VLAN_HACK                @USE_VLAN_HACK@
 
 #define HAVE_DLT_RAW                 @HAVE_DLT_RAW@
 #define HAVE_DLT_PFLOG               @HAVE_DLT_PFLOG@

configure

@@ -666,6 +666,7 @@ enable_ipv6
 enable_pcap_restart
 enable_pcre
 enable_tcpkill
+enable_vlan_hack
 with_pcap_includes
 '
       ac_precious_vars='build_alias
@@ -1305,6 +1306,7 @@ Optional Features:
   --enable-pcap-restart   enable BPF lexer restart bugfix for older versions of PCAP (default off)
   --enable-pcre           use PCRE instead of GNU regex (default GNU)
   --enable-tcpkill        enable connection killing support (default off)
+  --disable-vlan-hack     disable automatic inclusion of VLAN frames (default on)
 
 Optional Packages:
   --with-PACKAGE[=ARG]    use PACKAGE [ARG=yes]
@@ -3514,6 +3516,21 @@ else
 fi
 
 
+# Check whether --enable-vlan-hack was given.
+if test "${enable_vlan_hack+set}" = set; then :
+  enableval=$enable_vlan_hack; use_vlan_hack="$enableval"
+else
+  use_vlan_hack="yes"
+fi
+
+
+if test $use_vlan_hack = yes; then
+  USE_VLAN_HACK="1"
+else
+  USE_VLAN_HACK="0"
+fi
+
+
 
 # Check whether --with-pcap-includes was given.
 if test "${with_pcap_includes+set}" = set; then :
@@ -4075,6 +4092,11 @@ cat >>confdefs.h <<_ACEOF
 _ACEOF
 
 
+cat >>confdefs.h <<_ACEOF
+#define USE_VLAN_HACK $USE_VLAN_HACK
+_ACEOF
+
+
 
 cat >>confdefs.h <<_ACEOF
 #define USE_DROPPRIVS $USE_DROPPRIVS
@@ -4170,6 +4192,14 @@ else
 $as_echo "CONFIG: tcpkill feature disabled" >&6; }
 fi
 
+if test "$USE_VLAN_HACK" = "1"; then
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: CONFIG: automatically including VLAN frames" >&5
+$as_echo "CONFIG: automatically including VLAN frames" >&6; }
+else
+    { $as_echo "$as_me:${as_lineno-$LINENO}: result: CONFIG: not automatically including VLAN frames" >&5
+$as_echo "CONFIG: not automatically including VLAN frames" >&6; }
+fi
+
 
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: " >&5
 $as_echo "" >&6; }

configure.in

@@ -189,6 +189,18 @@ else
 fi
 
 
+AC_ARG_ENABLE(vlan-hack,
+[  --disable-vlan-hack     disable automatic inclusion of VLAN frames (default on)],
+[use_vlan_hack="$enableval"],
+[use_vlan_hack="yes"])
+
+if test $use_vlan_hack = yes; then
+  USE_VLAN_HACK="1"
+else
+  USE_VLAN_HACK="0"
+fi
+
+
 AC_ARG_WITH(pcap-includes,
 [  --with-pcap-includes=dir       specify the pcap include directory],
 [PCAP_DIR=$withval],
@@ -467,6 +479,7 @@ AC_DEFINE_UNQUOTED(PCAP_RESTART_FUNC,         $PCAP_RESTART_FUNC,         [routi
 AC_DEFINE_UNQUOTED(USE_PCRE,                  $USE_PCRE,                  [whether to use PCRE (default GNU Regex)])
 AC_DEFINE_UNQUOTED(USE_IPv6,                  $USE_IPv6,                  [whether to use IPv6 (default off)])
 AC_DEFINE_UNQUOTED(USE_TCPKILL,               $USE_TCPKILL,               [whether to enable tcpkill functionality (default off)])
+AC_DEFINE_UNQUOTED(USE_VLAN_HACK,             $USE_VLAN_HACK,             [whether to automatically include VLAN frames (default on)])
 
 AC_DEFINE_UNQUOTED(USE_DROPPRIVS,             $USE_DROPPRIVS,             [whether to use privileges dropping (default yes)])
 AC_DEFINE_UNQUOTED(DROPPRIVS_USER,           "$DROPPRIVS_USER",           [pseudo-user for running ngrep (default "nobody")])
@@ -523,6 +536,12 @@ else
     AC_MSG_RESULT(CONFIG: tcpkill feature disabled)
 fi
 
+if test "$USE_VLAN_HACK" = "1"; then
+    AC_MSG_RESULT(CONFIG: automatically including VLAN frames)
+else
+    AC_MSG_RESULT(CONFIG: NOT automatically including VLAN frames)
+fi
+
 dnl
 dnl And we're done.  ALL YOUR BASE.  Don't forget.
 dnl

ngrep.c

@@ -159,7 +159,7 @@ char *filter = NULL, *filter_file = NULL;
 char pc_err[PCAP_ERRBUF_SIZE];
 uint8_t link_offset;
 uint8_t radiotap_present = 0;
-uint8_t include_vlan = 1;
+uint8_t include_vlan = USE_VLAN_HACK;
 
 pcap_t *pd = NULL, *pd_dumppcap = NULL;
 pcap_dumper_t *pd_dump = NULL;