f5ethtrailer: fix memleak and fix tap registration

On startup, not all protocols are ready. In particular, the ip, ipv6 and
tcp tap registrations failed (and the error messages were leaked). Fix
this by performing this registration when a capture file is loaded.

Change-Id: Idd0634e395d484bae67b343ea23a84d440c4f4bc
Reviewed-on: https://code.wireshark.org/review/26641
Petri-Dish: Peter Wu <peter@lekensteyn.nl>
Tested-by: Petri Dish Buildbot
Reviewed-by: Michael Mann <mmann78@netscape.net>
Reviewed-by: Anders Broman <a.broman58@gmail.com>

1 files changed, 53 insertions, 16 deletions

diff --git a/epan/dissectors/packet-f5ethtrailer.c b/epan/dissectors/packet-f5ethtrailer.c
index e29be1671a..ea4ee8206d 100644
--- a/epan/dissectors/packet-f5ethtrailer.c
+++ b/epan/dissectors/packet-f5ethtrailer.c
@@ -229,6 +229,7 @@ Notes:
 #include <epan/etypes.h>
 #include <epan/to_str.h>
 #include <epan/stats_tree.h>
+#include <wsutil/ws_printf.h>	/* for ws_g_warning */
 #define F5FILEINFOTAP_SRC
 #include "packet-f5ethtrailer.h"
 #undef  F5FILEINFOTAP_SRC
@@ -332,6 +333,13 @@ static gboolean pop_other_fields = FALSE;
 /** Wireshark preference to perform analysis */
 static gboolean pref_perform_analysis = TRUE;
 
+/** Identifiers for taps (when enabled), only the address is important, the
+ * values are unused. */
+static gint tap_ip_enabled;
+static gint tap_ipv6_enabled;
+static gint tap_tcp_enabled;
+
+
 /** Used "in" and "out" map for the true and false for ingress. (Not actually
  * used in field definition, but rather used to display via a format call
  * and in the info column information.) */
@@ -2191,14 +2199,40 @@ static void proto_init_f5ethtrailer(void)
 		f5eth_set_info_col = f5eth_set_info_col_slot;
 		break;
 	}
+
+	/* If we are doing analysis, enable the tap listeners */
+	if(pref_perform_analysis) {
+		GString *error_string;
+
+		error_string = register_tap_listener("ip", &tap_ip_enabled, NULL, TL_REQUIRES_NOTHING, NULL, ip_tap_pkt, NULL);
+		if (error_string) {
+			ws_g_warning("Unable to register tap \"ip\" for f5ethtrailer: %s", error_string->str);
+			g_string_free(error_string, TRUE);
+		}
+		error_string = register_tap_listener("ipv6", &tap_ipv6_enabled, NULL, TL_REQUIRES_NOTHING, NULL, ipv6_tap_pkt, NULL);
+		if (error_string) {
+			ws_g_warning("Unable to register tap \"ipv6\" for f5ethtrailer: %s", error_string->str);
+			g_string_free(error_string, TRUE);
+		}
+		error_string = register_tap_listener("tcp", &tap_tcp_enabled, NULL, TL_REQUIRES_NOTHING, NULL, tcp_tap_pkt, NULL);
+		if (error_string) {
+			ws_g_warning("Unable to register tap \"tcp\" for f5ethtrailer: %s", error_string->str);
+			g_string_free(error_string, TRUE);
+		}
+	}
 }
 
-static void f5ethtrailer_prefs(void)
+/** Cleanup after closing a capture file. */
+static void
+f5ethtrailer_cleanup(void)
 {
-	static gint tap_ip_enabled = -1;
-	static gint tap_ipv6_enabled = -1;
-	static gint tap_tcp_enabled = -1;
+	remove_tap_listener(&tap_tcp_enabled);
+	remove_tap_listener(&tap_ipv6_enabled);
+	remove_tap_listener(&tap_ip_enabled);
+}
 
+static void f5ethtrailer_prefs(void)
+{
 	wmem_free(NULL, info_format_in_only);
 	wmem_free(NULL, info_format_out_only);
 	wmem_free(NULL, info_format_in_slot);
@@ -2237,17 +2271,6 @@ static void f5ethtrailer_prefs(void)
 		info_format_out_noslot = wmem_strdup(NULL, info_format_full_out_noslot);
 		break;
 	}
-
-	remove_tap_listener(&tap_tcp_enabled);
-	remove_tap_listener(&tap_ipv6_enabled);
-	remove_tap_listener(&tap_ip_enabled);
-
-	/* If we are doing analysis, enable the tap listeners */
-	if(pref_perform_analysis) {
-		register_tap_listener("ip", &tap_ip_enabled, NULL, TL_REQUIRES_NOTHING, NULL, ip_tap_pkt, NULL);
-		register_tap_listener("ipv6", &tap_ipv6_enabled, NULL, TL_REQUIRES_NOTHING, NULL, ipv6_tap_pkt, NULL);
-		register_tap_listener("tcp", &tap_tcp_enabled, NULL, TL_REQUIRES_NOTHING, NULL, tcp_tap_pkt, NULL);
-	}
 }
 
 void proto_register_f5ethtrailer (void)
@@ -2495,7 +2518,7 @@ void proto_register_f5ethtrailer (void)
 	prefs_register_bool_preference(f5ethtrailer_module, "perform_analysis",
 		"Perform analysis of trailer data",
 		"Enabling this will perform analysis of the trailer data.  It will"
-		" enable taps on other protocols and slow down wireshark.",
+		" enable taps on other protocols and slow down Wireshark.",
 		&pref_perform_analysis);
 
 	prefs_register_static_text_preference(f5ethtrailer_module,
@@ -2537,6 +2560,7 @@ void proto_register_f5ethtrailer (void)
 		&rstcause_in_info);
 
 	register_init_routine(proto_init_f5ethtrailer);
+	register_cleanup_routine(f5ethtrailer_cleanup);
 
 	/* Analyze Menu Items */
 	register_conversation_filter("f5ethtrailer", "F5 TCP", f5_tcp_conv_valid, f5_tcp_conv_filter);
@@ -2708,3 +2732,16 @@ void proto_reg_handoff_f5fileinfo(void)
 {
 	heur_dissector_add("eth", dissect_f5fileinfo, "F5 Capture Information", "f5fileinfo", proto_f5fileinfo, HEURISTIC_ENABLE);
 }
+
+/*
+ * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
+ *
+ * Local variables:
+ * c-basic-offset: 4
+ * tab-width: 8
+ * indent-tabs-mode: t
+ * End:
+ *
+ * vi: set shiftwidth=4 tabstop=8 noexpandtab:
+ * :indentSize=4:tabSize=8:noTabs=false:
+ */