1 files changed, 129 insertions, 0 deletions
diff --git a/usr.sbin/bhyve/config.h b/usr.sbin/bhyve/config.h
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+++ b/usr.sbin/bhyve/config.h
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+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2021 John H. Baldwin <jhb@FreeBSD.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef __CONFIG_H__
+#define	__CONFIG_H__
+
+#include <sys/nv.h>
+
+/*-
+ * Manages a configuration database backed by an nv(9) list.
+ *
+ * The database only stores string values.  Callers should parse
+ * values into other types if needed.  String values can reference
+ * other configuration variables using a '%(name)' syntax.  In this
+ * case, the name must be the full path of the configuration
+ * variable.  The % character can be escaped with a preceding \ to
+ * avoid expansion.  Any \ characters must be escaped.
+ *
+ * Configuration variables are stored in a tree.  The full path of a
+ * variable is specified as a dot-separated name similar to sysctl(8)
+ * OIDs.
+ */
+
+/*
+ * Fetches the value of a configuration variable.  If the "raw" value
+ * contains references to other configuration variables, this function
+ * expands those references and returns a pointer to the parsed
+ * string.  The string's storage is only stable until the next call to
+ * this function.
+ *
+ * If no node is found, returns NULL.
+ *
+ * If 'parent' is NULL, 'name' is assumed to be a top-level variable.
+ */
+const char *get_config_value_node(const nvlist_t *parent, const char *name);
+
+/*
+ * Similar to get_config_value_node but expects a full path to the
+ * leaf node.
+ */
+const char *get_config_value(const char *path);
+
+/* Initializes the tree to an empty state. */
+void	init_config(void);
+
+/*
+ * Creates an existing configuration node via a dot-separated OID
+ * path.  Will fail if the path names an existing leaf configuration
+ * variable.  If the node already exists, this returns a pointer to
+ * the existing node.
+ */
+nvlist_t *create_config_node(const char *path);
+
+/*
+ * Looks for an existing configuration node via a dot-separated OID
+ * path.  Will fail if the path names an existing leaf configuration
+ * variable.
+ */
+nvlist_t *find_config_node(const char *path);
+
+/*
+ * Similar to the above, but treats the path relative to an existing
+ * 'parent' node rather than as an absolute path.
+ */
+nvlist_t *create_relative_config_node(nvlist_t *parent, const char *path);
+nvlist_t *find_relative_config_node(nvlist_t *parent, const char *path);
+
+/*
+ * Adds or replaces the value of the specified variable.
+ *
+ * If 'parent' is NULL, 'name' is assumed to be a top-level variable.
+ */
+void	set_config_value_node(nvlist_t *parent, const char *name,
+    const char *value);
+
+/*
+ * Similar to set_config_value_node but only sets value if it's unset yet.
+ */
+void 	set_config_value_node_if_unset(nvlist_t *const parent,
+    const char *const name, const char *const value);
+
+/*
+ * Similar to set_config_value_node but expects a full path to the
+ * leaf node.
+ */
+void	set_config_value(const char *path, const char *value);
+
+/*
+ * Similar to set_config_value but only sets the value if it's unset yet.
+ */
+void 	set_config_value_if_unset(const char *const path,
+    const char *const value);
+
+/* Convenience wrappers for boolean variables. */
+bool	get_config_bool(const char *path);
+bool	get_config_bool_node(const nvlist_t *parent, const char *name);
+bool	get_config_bool_default(const char *path, bool def);
+bool	get_config_bool_node_default(const nvlist_t *parent, const char *name,
+    bool def);
+void	set_config_bool(const char *path, bool value);
+void	set_config_bool_node(nvlist_t *parent, const char *name, bool value);
+
+void	dump_config(void);
+
+#endif /* !__CONFIG_H__ */