wslua: Add ability to query current temporary color filter text

The LUA API provides the "set_color_filter_slot" function, but without
a corresponding "get_" function, it's very hard for two LUA dissectors
to co-exist without one overwriting any color filters set by the other.

It also looks like the documentation comment for
"set_color_filter_slot" had an off-by-one error, which I've corrected
as I was adding almost identical documentation for the new API.

Change-Id: Ic54d23be555ec12e1830bbe6f84a1b04d04fd4f0
Reviewed-on: https://code.wireshark.org/review/37511
Petri-Dish: Anders Broman <a.broman58@gmail.com>
Tested-by: Petri Dish Buildbot
Reviewed-by: Anders Broman <a.broman58@gmail.com>

7 files changed, 94 insertions, 12 deletions

diff --git a/debian/libwireshark0.symbols b/debian/libwireshark0.symbols
index c1eead9326..600a6711c4 100644
--- a/debian/libwireshark0.symbols
+++ b/debian/libwireshark0.symbols
@@ -137,6 +137,7 @@ libwireshark.so.0 libwireshark0 #MINVER#
  color_filters_clone@Base 2.1.0
  color_filters_colorize_packet@Base 2.1.0
  color_filters_export@Base 2.1.0
+ color_filters_get_tmp@Base 3.3.0
  color_filters_import@Base 2.1.0
  color_filters_init@Base 2.1.0
  color_filters_prime_edt@Base 2.1.0
diff --git a/epan/color_filters.c b/epan/color_filters.c
index cb5586529c..8dfd8c2e32 100644
--- a/epan/color_filters.c
+++ b/epan/color_filters.c
@@ -119,6 +119,29 @@ color_filters_find_by_name_cb(gconstpointer arg1, gconstpointer arg2)
     return strcmp(colorf->filter_name, name);
 }
 
+/* Get the filter of a temporary color filter */
+gchar*
+color_filters_get_tmp(guint8 filt_nr)
+{
+    gchar* name = NULL;
+    gchar* filter = NULL;
+    GSList* cfl;
+    color_filter_t* colorf;
+    /* Only perform a lookup if the supplied filter number is in the expected range */
+    if (filt_nr < 1 || filt_nr > 10)
+        return NULL;
+
+    name = g_strdup_printf("%s%02d", CONVERSATION_COLOR_PREFIX, filt_nr);
+    cfl = g_slist_find_custom(color_filter_list, name, color_filters_find_by_name_cb);
+    colorf = (color_filter_t*)cfl->data;
+
+    if (!colorf->disabled)
+        filter = g_strdup(colorf->filter_text);
+
+    g_free(name);
+
+    return filter;
+}
 
 /* Set the filter off a temporary colorfilters and enable it */
 gboolean
diff --git a/epan/color_filters.h b/epan/color_filters.h
index 092de7af68..873b85508f 100644
--- a/epan/color_filters.h
+++ b/epan/color_filters.h
@@ -70,6 +70,14 @@ WS_DLL_PUBLIC gboolean color_filters_used(void);
  */
 WS_DLL_PUBLIC gboolean tmp_color_filters_used(void);
 
+/** Get the filter string of a temporary color filter
+ *
+ * @param filt_nr a number 1-10 pointing to a temporary color
+ * @return the current filter string which is assigned to the specified slot, or NULL if not available.
+ */
+WS_DLL_PUBLIC gchar*
+color_filters_get_tmp(guint8 filt_nr);
+
 /** Set the filter string of a temporary color filter
  *
  * @param filt_nr a number 1-10 pointing to a temporary color
diff --git a/epan/funnel.h b/epan/funnel.h
index 534a5baa8c..0953b9f6f6 100644
--- a/epan/funnel.h
+++ b/epan/funnel.h
@@ -80,7 +80,8 @@ typedef struct _funnel_ops_t {
 
     const gchar * (*get_filter)(funnel_ops_id_t *ops_id);
     void (*set_filter)(funnel_ops_id_t *ops_id, const char* filter);
-    void (*set_color_filter_slot)(guint8 flit_nr, const gchar* filter);
+    gchar * (*get_color_filter_slot)(guint8 filt_nr);
+    void (*set_color_filter_slot)(guint8 filt_nr, const gchar* filter);
     gboolean (*open_file)(funnel_ops_id_t *ops_id, const char* fname, const char* filter, char** error);
     void (*reload_packets)(funnel_ops_id_t *ops_id);
     void (*reload_lua_plugins)(funnel_ops_id_t *ops_id);
diff --git a/epan/wslua/wslua_gui.c b/epan/wslua/wslua_gui.c
index fd6f5ff96e..17d72070c2 100644
--- a/epan/wslua/wslua_gui.c
+++ b/epan/wslua/wslua_gui.c
@@ -929,13 +929,55 @@ WSLUA_FUNCTION wslua_set_filter(lua_State* L) { /* Set the main filter text. */
     return 0;
 }
 
+WSLUA_FUNCTION wslua_get_color_filter_slot(lua_State* L) { /*
+    Gets the current https://wiki.wireshark.org/ColoringRules[packet coloring rule] (by index) for the
+    current session. Wireshark reserves 10 slots for these coloring rules. Requires a GUI.
+*/
+#define WSLUA_ARG_get_color_filter_slot_ROW 1 /*
+    The index (1-10) of the desired color filter value in the temporary coloring rules list.
+
+    .Default background colors
+    [cols="3",options="header"]
+    |===
+    |Index |RGB (hex) |Color
+    |1  |ffc0c0 |{set:cellbgcolor:#ffc0c0} pink 1
+    |2  |ffc0ff |{set:cellbgcolor:#ffc0ff} pink 2
+    |3  |e0c0e0 |{set:cellbgcolor:#e0c0e0} purple 1
+    |4  |c0c0ff |{set:cellbgcolor:#c0c0ff} purple 2
+    |5  |c0e0e0 |{set:cellbgcolor:#c0e0e0} green 1
+    |6  |c0ffff |{set:cellbgcolor:#c0ffff} green 2
+    |7  |c0ffc0 |{set:cellbgcolor:#c0ffc0} green 3
+    |8  |ffffc0 |{set:cellbgcolor:#ffffc0} yellow 1
+    |9  |e0e0c0 |{set:cellbgcolor:#e0e0c0} yellow 2
+    |10 |e0e0e0 |{set:cellbgcolor:#e0e0e0} gray
+    |===
+    */
+    guint8 row = (guint8)luaL_checkinteger(L, WSLUA_ARG_get_color_filter_slot_ROW);
+    gchar* filter_str = NULL;
+
+    if (!ops->get_color_filter_slot) {
+        WSLUA_ERROR(get_color_filter_slot, "GUI not available");
+        return 0;
+    }
+
+    filter_str = ops->get_color_filter_slot(row);
+    if (filter_str == NULL) {
+        lua_pushnil(L);
+    } else {
+        lua_pushstring(L, filter_str);
+        g_free(filter_str);
+    }
+
+    return 1;
+}
+
 WSLUA_FUNCTION wslua_set_color_filter_slot(lua_State* L) { /*
     Sets a https://wiki.wireshark.org/ColoringRules[packet coloring rule] (by index) for the current session.
     Wireshark reserves 10 slots for these coloring rules.
     Requires a GUI.
 */
 #define WSLUA_ARG_set_color_filter_slot_ROW 1 /*
-    The index (0-9) of the desired color in the temporary coloring rules list.
+    The index (1-10) of the desired color in the temporary coloring rules list.
     The default foreground is black and the default backgrounds are listed below.
 
     // XXX We need get the colors working, e.g. by adding them to a stylesheet.
@@ -943,16 +985,16 @@ WSLUA_FUNCTION wslua_set_color_filter_slot(lua_State* L) { /*
     [cols="3",options="header"]
     |===
     |Index |RGB (hex) |Color
-    |0 |ffc0c0 |{set:cellbgcolor:#ffc0c0} pink 1
-    |1 |ffc0ff |{set:cellbgcolor:#ffc0ff} pink 2
-    |2 |e0c0e0 |{set:cellbgcolor:#e0c0e0} purple 1
-    |3 |c0c0ff |{set:cellbgcolor:#c0c0ff} purple 2
-    |4 |c0e0e0 |{set:cellbgcolor:#c0e0e0} green 1
-    |5 |c0ffff |{set:cellbgcolor:#c0ffff} green 2
-    |6 |c0ffc0 |{set:cellbgcolor:#c0ffc0} green 3
-    |7 |ffffc0 |{set:cellbgcolor:#ffffc0} yellow 1
-    |8 |e0e0c0 |{set:cellbgcolor:#e0e0c0} yellow 2
-    |9 |e0e0e0 |{set:cellbgcolor:#e0e0e0} gray
+    |1  |ffc0c0 |{set:cellbgcolor:#ffc0c0} pink 1
+    |2  |ffc0ff |{set:cellbgcolor:#ffc0ff} pink 2
+    |3  |e0c0e0 |{set:cellbgcolor:#e0c0e0} purple 1
+    |4  |c0c0ff |{set:cellbgcolor:#c0c0ff} purple 2
+    |5  |c0e0e0 |{set:cellbgcolor:#c0e0e0} green 1
+    |6  |c0ffff |{set:cellbgcolor:#c0ffff} green 2
+    |7  |c0ffc0 |{set:cellbgcolor:#c0ffc0} green 3
+    |8  |ffffc0 |{set:cellbgcolor:#ffffc0} yellow 1
+    |9  |e0e0c0 |{set:cellbgcolor:#e0e0c0} yellow 2
+    |10 |e0e0e0 |{set:cellbgcolor:#e0e0e0} gray
     |===
 
     The color list can be set from the command line using two unofficial preferences: `gui.colorized_frame.bg` and `gui.colorized_frame.fg`, which require 10 hex RGB codes (6 hex digits each), e.g.
diff --git a/ui/cli/tap-funnel.c b/ui/cli/tap-funnel.c
index 0b24096f8c..0171abaa8b 100644
--- a/ui/cli/tap-funnel.c
+++ b/ui/cli/tap-funnel.c
@@ -103,6 +103,7 @@ static const funnel_ops_t funnel_ops = {
     NULL,
     NULL,
     NULL,
+    NULL,
     NULL
 };
 
diff --git a/ui/qt/funnel_statistics.cpp b/ui/qt/funnel_statistics.cpp
index cc9dbc0156..c7f67e600a 100644
--- a/ui/qt/funnel_statistics.cpp
+++ b/ui/qt/funnel_statistics.cpp
@@ -42,6 +42,7 @@ static void funnel_statistics_retap_packets(funnel_ops_id_t *ops_id);
 static void funnel_statistics_copy_to_clipboard(GString *text);
 static const gchar *funnel_statistics_get_filter(funnel_ops_id_t *ops_id);
 static void funnel_statistics_set_filter(funnel_ops_id_t *ops_id, const char* filter_string);
+static gchar* funnel_statistics_get_color_filter_slot(guint8 filter_num);
 static void funnel_statistics_set_color_filter_slot(guint8 filter_num, const gchar* filter_string);
 static gboolean funnel_statistics_open_file(funnel_ops_id_t *ops_id, const char* fname, const char* filter, char**);
 static void funnel_statistics_reload_packets(funnel_ops_id_t *ops_id);
@@ -130,6 +131,7 @@ FunnelStatistics::FunnelStatistics(QObject *parent, CaptureFile &cf) :
     funnel_ops_->copy_to_clipboard = funnel_statistics_copy_to_clipboard;
     funnel_ops_->get_filter = funnel_statistics_get_filter;
     funnel_ops_->set_filter = funnel_statistics_set_filter;
+    funnel_ops_->get_color_filter_slot = funnel_statistics_get_color_filter_slot;
     funnel_ops_->set_color_filter_slot = funnel_statistics_set_color_filter_slot;
     funnel_ops_->open_file = funnel_statistics_open_file;
     funnel_ops_->reload_packets = funnel_statistics_reload_packets;
@@ -241,6 +243,10 @@ void funnel_statistics_set_filter(funnel_ops_id_t *ops_id, const char* filter_st
     ops_id->funnel_statistics->emitSetDisplayFilter(filter_string);
 }
 
+gchar* funnel_statistics_get_color_filter_slot(guint8 filter_num) {
+    return color_filters_get_tmp(filter_num);
+}
+
 void funnel_statistics_set_color_filter_slot(guint8 filter_num, const gchar* filter_string) {
     gchar *err_msg = nullptr;
     if (!color_filters_set_tmp(filter_num, filter_string, FALSE, &err_msg)) {