2 * SPDX-License-Identifier: BSD-2-Clause
4 * Copyright (c) 2021 John H. Baldwin <jhb@FreeBSD.org>
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24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * Manages a configuration database backed by an nv(9) list.
36 * The database only stores string values. Callers should parse
37 * values into other types if needed. String values can reference
38 * other configuration variables using a '%(name)' syntax. In this
39 * case, the name must be the full path of the configuration
40 * variable. The % character can be escaped with a preceding \ to
41 * avoid expansion. Any \ characters must be escaped.
43 * Configuration variables are stored in a tree. The full path of a
44 * variable is specified as a dot-separated name similar to sysctl(8)
49 * Fetches the value of a configuration variable. If the "raw" value
50 * contains references to other configuration variables, this function
51 * expands those references and returns a pointer to the parsed
52 * string. The string's storage is only stable until the next call to
55 * If no node is found, returns NULL.
57 * If 'parent' is NULL, 'name' is assumed to be a top-level variable.
59 const char *get_config_value_node(const nvlist_t *parent, const char *name);
62 * Similar to get_config_value_node but expects a full path to the
65 const char *get_config_value(const char *path);
67 /* Initializes the tree to an empty state. */
68 void init_config(void);
71 * Creates an existing configuration node via a dot-separated OID
72 * path. Will fail if the path names an existing leaf configuration
73 * variable. If the node already exists, this returns a pointer to
76 nvlist_t *create_config_node(const char *path);
79 * Looks for an existing configuration node via a dot-separated OID
80 * path. Will fail if the path names an existing leaf configuration
83 nvlist_t *find_config_node(const char *path);
86 * Similar to the above, but treats the path relative to an existing
87 * 'parent' node rather than as an absolute path.
89 nvlist_t *create_relative_config_node(nvlist_t *parent, const char *path);
90 nvlist_t *find_relative_config_node(nvlist_t *parent, const char *path);
93 * Adds or replaces the value of the specified variable.
95 * If 'parent' is NULL, 'name' is assumed to be a top-level variable.
97 void set_config_value_node(nvlist_t *parent, const char *name,
101 * Similar to set_config_value_node but only sets value if it's unset yet.
103 void set_config_value_node_if_unset(nvlist_t *const parent,
104 const char *const name, const char *const value);
107 * Similar to set_config_value_node but expects a full path to the
110 void set_config_value(const char *path, const char *value);
113 * Similar to set_config_value but only sets the value if it's unset yet.
115 void set_config_value_if_unset(const char *const path,
116 const char *const value);
118 /* Convenience wrappers for boolean variables. */
119 bool get_config_bool(const char *path);
120 bool get_config_bool_node(const nvlist_t *parent, const char *name);
121 bool get_config_bool_default(const char *path, bool def);
122 bool get_config_bool_node_default(const nvlist_t *parent, const char *name,
124 void set_config_bool(const char *path, bool value);
125 void set_config_bool_node(nvlist_t *parent, const char *name, bool value);
127 void dump_config(void);
129 #endif /* !__CONFIG_H__ */