extcap: Tell utilities the wireshark version

Add an optional argument to extcap-version, which tells the utilities
the wireshark version and therefore allows them to handle different
versions differently.

If no version is provided, the utility has to assume it is dealing
with a Wireshark 2.x version (default behavior).

Change-Id: I51658300f28f503ca8050d204b73749f1a54df16
Reviewed-on: https://code.wireshark.org/review/26752
Petri-Dish: Roland Knall <rknall@gmail.com>
Tested-by: Petri Dish Buildbot
Reviewed-by: Roland Knall <rknall@gmail.com>

5 files changed, 37 insertions, 1 deletions

diff --git a/doc/extcap_example.py b/doc/extcap_example.py
index 12ee0cd2aa..568dc1a25b 100755
--- a/doc/extcap_example.py
+++ b/doc/extcap_example.py
@@ -142,6 +142,9 @@ def extcap_config(interface):
         print ("value {arg=%d}{value=%s}{display=%s}{default=%s}" % value)
 
 
+def extcap_version():
+    print ("extcap {version=1.0}{help=http://www.wireshark.org}{display=Example extcap interface}")
+
 def extcap_interfaces():
     print ("extcap {version=1.0}{help=http://www.wireshark.org}{display=Example extcap interface}")
     print ("interface {value=example1}{display=Example interface 1 for extcap}")
@@ -404,6 +407,7 @@ if __name__ == '__main__':
     parser.add_argument("--fifo", help="Use together with capture to provide the fifo to dump data to")
     parser.add_argument("--extcap-control-in", help="Used to get control messages from toolbar")
     parser.add_argument("--extcap-control-out", help="Used to send control messages to toolbar")
+    parser.add_argument("--extcap-version", help="Shows the version of this utility", action="store_true")
 
     # Interface Arguments
     parser.add_argument("--verify", help="Demonstrates a verification bool flag", action="store_true" )
@@ -431,6 +435,10 @@ if __name__ == '__main__':
     if ( len(sys.argv) <= 1 ):
         parser.exit("No arguments given!")
 
+    if ( args.extcap_version ):
+        extcap_version()
+        sys.exit(0)
+
     if ( args.extcap_interfaces == False and args.extcap_interface == None ):
         parser.exit("An interface must be provided or the selection must be displayed")
     if ( args.extcap_capture_filter and not args.capture ):
diff --git a/extcap.c b/extcap.c
index 061d4535e2..df5c3a726c 100644
--- a/extcap.c
+++ b/extcap.c
@@ -50,6 +50,8 @@
 #include "extcap.h"
 #include "extcap_parser.h"
 
+#include "version_info.h"
+
 #ifdef _WIN32
 static HANDLE pipe_h = INVALID_HANDLE_VALUE;
 #endif
@@ -1676,7 +1678,7 @@ static gboolean cb_load_interfaces(extcap_callback_info_t cb_info)
 static void
 extcap_load_interface_list(void)
 {
-    gchar *error;
+    gchar *error = NULL;
 
     if (prefs.capture_no_extcap)
         return;
@@ -1699,6 +1701,8 @@ extcap_load_interface_list(void)
     if (_loaded_interfaces == NULL)
     {
         GList * arguments = NULL;
+        int major = 0;
+        int minor = 0;
 
         _loaded_interfaces = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, extcap_free_interface_info);
         /* Cleanup lookup table */
@@ -1711,6 +1715,11 @@ extcap_load_interface_list(void)
         }
 
         arguments = g_list_append(arguments, g_strdup(EXTCAP_ARGUMENT_LIST_INTERFACES));
+        arguments = g_list_append(arguments, g_strdup(EXTCAP_ARGUMENT_VERSION));
+
+        get_ws_version_number(&major, &minor, NULL);
+
+        arguments = g_list_append(arguments, g_strdup_printf("%d.%d", major, minor));
 
         extcap_callback_info_t cb_info;
         cb_info.data = NULL;
@@ -1719,6 +1728,20 @@ extcap_load_interface_list(void)
 
         extcap_foreach(arguments, cb_load_interfaces, cb_info);
 
+        /* Compatibility mode. Utility did not accept version argument, therefore we just ask for the interfaces
+         * and assume, that the utility will handle compatibility on it's end */
+        if ( ! cb_info.data )
+        {
+            g_free(error);
+            error = NULL;
+
+            g_list_free_full(arguments, g_free);
+            arguments = NULL;
+
+            arguments = g_list_append(arguments, g_strdup(EXTCAP_ARGUMENT_LIST_INTERFACES));
+            extcap_foreach(arguments, cb_load_interfaces, cb_info);
+        }
+
         g_list_free_full(arguments, g_free);
     }
 }
diff --git a/extcap.h b/extcap.h
index d7728006e3..3f1eeed2f5 100644
--- a/extcap.h
+++ b/extcap.h
@@ -35,6 +35,7 @@
 #define EXTCAP_ARGUMENT_LIST_INTERFACES         "--extcap-interfaces"
 #define EXTCAP_ARGUMENT_INTERFACE               "--extcap-interface"
 #define EXTCAP_ARGUMENT_LIST_DLTS               "--extcap-dlts"
+#define EXTCAP_ARGUMENT_VERSION                 "--extcap-version"
 
 #define EXTCAP_ARGUMENT_RUN_CAPTURE             "--capture"
 #define EXTCAP_ARGUMENT_CAPTURE_FILTER          "--extcap-capture-filter"
diff --git a/extcap/extcap-base.c b/extcap/extcap-base.c
index 6ec654c790..45713adfd6 100644
--- a/extcap/extcap-base.c
+++ b/extcap/extcap-base.c
@@ -171,6 +171,7 @@ uint8_t extcap_base_parse_options(extcap_parameters * extcap, int result, char *
             extcap->do_list_interfaces = 1;
             break;
         case EXTCAP_OPT_VERSION:
+            extcap->ws_version = g_strdup(optargument);
             extcap->do_version = 1;
             break;
         case EXTCAP_OPT_LIST_DLTS:
@@ -297,6 +298,7 @@ void extcap_base_cleanup(extcap_parameters ** extcap)
     g_free((*extcap)->version);
     g_free((*extcap)->helppage);
     g_free((*extcap)->help_header);
+    g_free((*extcap)->ws_version);
     g_list_foreach((*extcap)->help_options, (GFunc)extcap_help_option_free, NULL);
     g_list_free((*extcap)->help_options);
     g_free(*extcap);
diff --git a/extcap/extcap-base.h b/extcap/extcap-base.h
index 264281577c..9413bf931f 100644
--- a/extcap/extcap-base.h
+++ b/extcap/extcap-base.h
@@ -75,6 +75,8 @@ typedef struct _extcap_parameters
 	uint8_t capture;
 	uint8_t show_config;
 
+	char * ws_version;
+
 	/* private content */
 	GList * interfaces;
 	uint8_t do_version;