From 007ca97f25c20971ebfd2032db7e305351bac5d8 Mon Sep 17 00:00:00 2001
From: Michael Brown <mcb30@etherboot.org>
Date: Tue, 12 Dec 2006 15:49:46 +0000
Subject: [PATCH] Added clear_setting()

---
 src/core/settings.c         | 27 +++++++++++++++++++++++++--
 src/include/gpxe/settings.h |  1 +
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/src/core/settings.c b/src/core/settings.c
index 650673be..3eface4b 100644
--- a/src/core/settings.c
+++ b/src/core/settings.c
@@ -115,7 +115,8 @@ find_or_build_config_setting ( const char *name,
 	return setting;
 }
 
-/** Show value of setting
+/**
+ * Show value of setting
  *
  * @v context		Configuration context
  * @v name		Configuration setting name
@@ -134,7 +135,8 @@ int show_setting ( struct config_context *context, const char *name,
 	return setting->type->show ( context, setting, buf, len );
 }
 
-/** Set value of setting
+/**
+ * Set value of setting
  *
  * @v context		Configuration context
  * @v name		Configuration setting name
@@ -152,6 +154,27 @@ int set_setting ( struct config_context *context, const char *name,
 	return setting->type->set ( context, setting, value );
 }
 
+/**
+ * Clear setting
+ *
+ * @v context		Configuration context
+ * @v name		Configuration setting name
+ * @ret rc		Return status code
+ */
+int clear_setting ( struct config_context *context, const char *name ) {
+	struct config_setting *setting;
+	struct config_setting tmp_setting;
+
+	setting = find_or_build_config_setting ( name, &tmp_setting );
+	if ( ! setting )
+		return -ENOENT;
+
+	/* All types of settings get cleared the same way */
+	delete_dhcp_option ( context->options, setting->tag );
+
+	return 0;
+}
+
 /**
  * Show value of string setting
  *
diff --git a/src/include/gpxe/settings.h b/src/include/gpxe/settings.h
index f5ecae94..ab0de5b4 100644
--- a/src/include/gpxe/settings.h
+++ b/src/include/gpxe/settings.h
@@ -102,5 +102,6 @@ extern int show_setting ( struct config_context *context, const char *name,
 			  char *buf, size_t len );
 extern int set_setting ( struct config_context *context, const char *name,
 			 const char *value );
+extern int clear_setting ( struct config_context *context, const char *name );
 
 #endif /* _GPXE_SETTINGS_H */