extcap: Convert settings to preference friendly key names

Preferences are only allowed to contain lowercase ASCII letters,
numbers, underscores or dot characters. Create a utility function
to convert an extcap setting to its equivalent preference key and
use it wherever conversion from setting to preference key is needed.

Bug: 12064
Change-Id: I39bbac7de5f0f905bd41c54257fa997a3b32442d
Reviewed-on: https://code.wireshark.org/review/13687
Petri-Dish: Pascal Quantin <pascal.quantin@gmail.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Roland Knall <rknall@gmail.com>

extcap.c

@@ -461,6 +461,34 @@ static void extcap_free_if_configuration(GList *list)
     g_list_free(list);
 }
 
+gchar * extcap_settings_key(const gchar * ifname, const gchar * setting)
+{
+    gchar * setting_nohyphen;
+    gchar * ifname_underscore;
+    gchar * ifname_lower;
+    gchar * key;
+    GRegex * regex = g_regex_new ("(?![a-zA-Z1-9_]).", (GRegexCompileFlags) 0, (GRegexMatchFlags) 0, NULL );
+
+    if (!regex)
+        return NULL;
+
+    setting_nohyphen =
+        g_regex_replace_literal(regex, setting, strlen(setting), 0,
+            "", (GRegexMatchFlags) 0, NULL );
+    ifname_underscore =
+        g_regex_replace_literal(regex, ifname, strlen(ifname), 0,
+            "_", (GRegexMatchFlags) 0, NULL );
+    ifname_lower = g_utf8_strdown(ifname_underscore, -1);
+    key = g_strconcat(ifname_lower, ".", setting_nohyphen, NULL);
+
+    g_free(setting_nohyphen);
+    g_free(ifname_underscore);
+    g_free(ifname_lower);
+    g_regex_unref(regex);
+
+    return key;
+}
+
 static gboolean search_cb(const gchar *extcap _U_, const gchar *ifname _U_, gchar *output, void *data,
         char **err_str _U_) {
     extcap_token_sentence *tokens = NULL;
@@ -482,16 +510,12 @@ static gboolean search_cb(const gchar *extcap _U_, const gchar *ifname _U_, gcha
     if ( dev_module ) {
         GList * walker = arguments;
 
-        GRegex * regex = g_regex_new ("[-]+", (GRegexCompileFlags) 0, (GRegexMatchFlags) 0, NULL );
-        if (regex) {
         while ( walker != NULL ) {
             extcap_arg * arg = (extcap_arg *)walker->data;
 
             if ( arg->save ) {
                 struct preference * pref = NULL;
-
+                gchar * pref_ifname = extcap_settings_key(ifname, arg->call);
-                    gchar * pref_name = g_regex_replace(regex, arg->call, strlen(arg->call), 0, "", (GRegexMatchFlags) 0, NULL );
-                    gchar * pref_ifname = g_strdup(g_strconcat(ifname, ".", pref_name, NULL));
 
                 if ( ( pref = prefs_find_preference(dev_module, pref_ifname) ) == NULL ) {
                     /* Set an initial value */
@@ -505,15 +529,11 @@ static gboolean search_cb(const gchar *extcap _U_, const gchar *ifname _U_, gcha
                     if (! arg->storeval && pref->varp.string)
                         arg->storeval = g_strdup(*(pref->varp.string));
                     }
-
-                    g_free(pref_name);
                 g_free(pref_ifname);
             }
 
             walker = g_list_next(walker);
         }
-            g_regex_unref(regex);
-        }
     }
 
     *il = g_list_append(*il, arguments);

extcap.h

@@ -87,6 +87,9 @@ extcap_get_if_configuration(const char * ifname);
 gboolean
 extcap_has_configuration(const char * ifname, gboolean is_required);
 
+/* converts an extcap setting to its equivalent preference key */
+gchar * extcap_settings_key(const gchar * ifname, const gchar * setting);
+
 #ifdef WIN32
 HANDLE
 extcap_get_win32_handle();

ui/qt/extcap_argument.cpp

@@ -593,12 +593,12 @@ QString ExtcapArgument::defaultValue()
     return QString();
 }
 
-QString ExtcapArgument::prefKey()
+QString ExtcapArgument::prefKey(const QString & device_name)
 {
     if ( ! _argument->save )
         return QString();
 
-    return QString(_argument->call).replace("-", "");
+    return QString(extcap_settings_key(device_name.toStdString().c_str(), _argument->call));
 }
 
 bool ExtcapArgument::isRequired()

ui/qt/extcap_argument.h

@@ -98,7 +98,7 @@ public:
     bool isValid();
     bool isRequired();
 
-    QString prefKey();
+    QString prefKey(const QString & device_name);
     virtual QString prefValue();
 
     static ExtcapArgument * create(extcap_arg * argument = 0);

ui/qt/extcap_options_dialog.cpp

@@ -373,16 +373,15 @@ void ExtcapOptionsDialog::storeValues()
         else
             value = (*iter)->prefValue();
 
-        QString prefKey = QString("%1.%2").arg(device_name).arg(argument->prefKey());
+        QString key = argument->prefKey(device_name);
-        if ( prefKey.length() > 0 )
+        if (key.length() > 0)
         {
-            gchar * key = g_strdup(prefKey.toStdString().c_str());
             gchar * val = g_strdup(value.length() == 0 ? " " : value.toStdString().c_str());
 
             /* Setting the internally stored value for the preference to the new value */
             (*iter)->argument()->storeval = g_strdup(val);
 
-            g_hash_table_insert(entries, key, val);
+            g_hash_table_insert(entries, g_strdup(key.toStdString().c_str()), val);
         }
     }