Allow a dissector to register preferences that it no longer supports as

obsolete; we silently ignore attempts to set those in a preferences
file, so that we don't spam the user with error messages caused by them
having saved preferences in an earlier release that contained those
preferences.

Make the Diameter and iSCSI dissectors register obsolete preferences.

Crash if some code tries to register a preferences module with a name
that contains something other than lower-case ASCII letters, numbers, or
underscores, or that has already been registered, or if some code tries
to register a preference with a name that contains something other than
lower-case ASCII letters, numbers, underscores, or periods, or that has
already been registered, so that we don't put code like that in a
release and have to shovel code into "prefs.c" to fix it up later.  (The
problem with multiple modules or preferences with the same name should
be obvious; the problem with names with blanks, or upper-case letters,
or punctuation, is that they're a pain to type on the command line.)

svn path=/trunk/; revision=4148

1 files changed, 95 insertions, 3 deletions

diff --git a/prefs.c b/prefs.c
index f58c1dce3c..257d91d336 100644
--- a/prefs.c
+++ b/prefs.c
@@ -1,7 +1,7 @@
 /* prefs.c
  * Routines for handling preferences
  *
- * $Id: prefs.c,v 1.69 2001/11/03 21:37:00 guy Exp $
+ * $Id: prefs.c,v 1.70 2001/11/04 02:50:19 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -53,6 +53,7 @@
 #include "prefs-int.h"
 
 /* Internal functions */
+static module_t *find_module(const char *name);
 static struct preference *find_preference(module_t *, const char *);
 static int    set_pref(gchar*, gchar*);
 static GList *get_string_list(gchar *);
@@ -111,6 +112,7 @@ prefs_register_module(const char *name, const char *title,
     void (*apply_cb)(void))
 {
 	module_t *module;
+	const guchar *p;
 
 	module = g_malloc(sizeof (module_t));
 	module->name = name;
@@ -120,6 +122,28 @@ prefs_register_module(const char *name, const char *title,
 	module->numprefs = 0;
 	module->prefs_changed = FALSE;
 
+	/*
+	 * Make sure that only lower-case ASCII letters, numbers, and
+	 * underscores appear in the module name.
+	 *
+	 * Crash if there is, as that's an error in the code;
+	 * you can make the title a nice string with capitalization,
+	 * white space, punctuation, etc., but the name can be used
+	 * on the command line, and shouldn't require quoting,
+	 * shifting, etc.
+	 */
+	for (p = name; *p != '\0'; p++)
+		g_assert(isascii(*p) &&
+		    (islower(*p) || isdigit(*p) || *p == '_'));
+
+	/*
+	 * Make sure there's not already a module with that
+	 * name.  Crash if there is, as that's an error in the
+	 * code, and the code has to be fixed not to register
+	 * more than one module with the same name.
+	 */
+	g_assert(find_module(name) == NULL);
+
 	modules = g_list_insert_sorted(modules, module, module_compare_name);
 
 	return module;
@@ -149,11 +173,11 @@ module_match(gconstpointer a, gconstpointer b)
 }
 
 static module_t *
-find_module(char *name)
+find_module(const char *name)
 {
 	GList *list_entry;
 
-	list_entry = g_list_find_custom(modules, name, module_match);
+	list_entry = g_list_find_custom(modules, (gpointer)name, module_match);
 	if (list_entry == NULL)
 		return NULL;	/* no such module */
 	return (module_t *) list_entry->data;
@@ -218,6 +242,7 @@ register_preference(module_t *module, const char *name, const char *title,
     const char *description)
 {
 	pref_t *preference;
+	const guchar *p;
 
 	preference = g_malloc(sizeof (pref_t));
 	preference->name = name;
@@ -226,6 +251,20 @@ register_preference(module_t *module, const char *name, const char *title,
 	preference->ordinal = module->numprefs;
 
 	/*
+	 * Make sure that only lower-case ASCII letters, numbers,
+	 * underscores, and dots appear in the preference name.
+	 *
+	 * Crash if there is, as that's an error in the code;
+	 * you can make the title and description nice strings
+	 * with capitalization, white space, punctuation, etc.,
+	 * but the name can be used on the command line,
+	 * and shouldn't require quoting, Shifting, etc.
+	 */
+	for (p = name; *p != '\0'; p++)
+		g_assert(isascii(*p) &&
+		    (islower(*p) || isdigit(*p) || *p == '_' || *p == '.'));
+
+	/*
 	 * Make sure there's not already a preference with that
 	 * name.  Crash if there is, as that's an error in the
 	 * code, and the code has to be fixed not to register
@@ -348,6 +387,18 @@ prefs_register_string_preference(module_t *module, const char *name,
 	preference->saved_val.string = NULL;
 }
 
+/*
+ * Register a preference that used to be supported but no longer is.
+ */
+void
+prefs_register_obsolete_preference(module_t *module, const char *name)
+{
+	pref_t *preference;
+
+	preference = register_preference(module, name, NULL, NULL);
+	preference->type = PREF_OBSOLETE;
+}
+
 typedef struct {
 	pref_cb callback;
 	gpointer user_data;
@@ -359,6 +410,17 @@ do_pref_callback(gpointer data, gpointer user_data)
 	pref_t *pref = data;
 	pref_cb_arg_t *arg = user_data;
 
+	if (pref->type == PREF_OBSOLETE) {
+		/*
+		 * This preference is no longer supported; it's not a
+		 * real preference, so we don't call the callback for
+		 * it (i.e., we treat it as if it weren't found in the
+		 * list of preferences, and we weren't called in the
+		 * first place).
+		 */
+		return;
+	}
+
 	(*arg->callback)(pref, arg->user_data);
 }
 
@@ -837,6 +899,13 @@ read_prefs_file(const char *pf_path, FILE *pf)
                 g_warning ("%s line %d: No such preference \"%s\"", pf_path,
 				pline, cur_var);
                 break;
+
+	      case PREFS_SET_OBSOLETE:
+	        /* We silently ignore attempts to set these; it's
+	           probably not the user's fault that it's in there -
+	           they may have saved preferences with a release that
+	           supported them. */
+                break;
               }
             } else {
               g_warning ("%s line %d: Incomplete preference", pf_path, pline);
@@ -898,6 +967,12 @@ read_prefs_file(const char *pf_path, FILE *pf)
         g_warning ("%s line %d: No such preference \"%s\"", pf_path,
 			pline, cur_var);
         break;
+
+      case PREFS_SET_OBSOLETE:
+	/* We silently ignore attempts to set these; it's probably not
+	   the user's fault that it's in there - they may have saved
+	   preferences with a release that supported it. */
+        break;
       }
     } else {
       g_warning ("%s line %d: Incomplete preference", pf_path, pline);
@@ -1355,6 +1430,9 @@ set_pref(gchar *pref_name, gchar *value)
         *pref->varp.string = g_strdup(value);
       }
       break;
+
+    case PREF_OBSOLETE:
+      return PREFS_SET_OBSOLETE;	/* no such preference any more */
     }
   }
   
@@ -1377,6 +1455,16 @@ write_pref(gpointer data, gpointer user_data)
 	const enum_val_t *enum_valp;
 	const char *val_string;
 
+	if (pref->type == PREF_OBSOLETE) {
+		/*
+		 * This preference is no longer supported; it's not a
+		 * real preference, so we don't write it out (i.e., we
+		 * treat it as if it weren't found in the list of
+		 * preferences, and we weren't called in the first place).
+		 */
+		return;
+	}
+
 	fprintf(arg->pf, "\n# %s\n", pref->description);
 
 	switch (pref->type) {
@@ -1434,6 +1522,10 @@ write_pref(gpointer data, gpointer user_data)
 		fprintf(arg->pf, "%s.%s: %s\n", arg->module->name, pref->name,
 		    *pref->varp.string);
 		break;
+
+	case PREF_OBSOLETE:
+		g_assert_not_reached();
+		break;
 	}
 }