1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2021 John H. Baldwin <jhb@FreeBSD.org> 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 * $FreeBSD$ 28 */ 29 30 #ifndef __CONFIG_H__ 31 #define __CONFIG_H__ 32 33 #include <sys/nv.h> 34 35 /*- 36 * Manages a configuration database backed by an nv(9) list. 37 * 38 * The database only stores string values. Callers should parse 39 * values into other types if needed. String values can reference 40 * other configuration variables using a '%(name)' syntax. In this 41 * case, the name must be the full path of the configuration 42 * variable. The % character can be escaped with a preceding \ to 43 * avoid expansion. Any \ characters must be escaped. 44 * 45 * Configuration variables are stored in a tree. The full path of a 46 * variable is specified as a dot-separated name similar to sysctl(8) 47 * OIDs. 48 */ 49 50 /* 51 * Fetches the value of a configuration variable. If the "raw" value 52 * contains references to other configuration variables, this function 53 * expands those references and returns a pointer to the parsed 54 * string. The string's storage is only stable until the next call to 55 * this function. 56 * 57 * If no node is found, returns NULL. 58 * 59 * If 'parent' is NULL, 'name' is assumed to be a top-level variable. 60 */ 61 const char *get_config_value_node(const nvlist_t *parent, const char *name); 62 63 /* 64 * Similar to get_config_value_node but expects a full path to the 65 * leaf node. 66 */ 67 const char *get_config_value(const char *path); 68 69 /* Initializes the tree to an empty state. */ 70 void init_config(void); 71 72 /* 73 * Creates an existing configuration node via a dot-separated OID 74 * path. Will fail if the path names an existing leaf configuration 75 * variable. If the node already exists, this returns a pointer to 76 * the existing node. 77 */ 78 nvlist_t *create_config_node(const char *path); 79 80 /* 81 * Looks for an existing configuration node via a dot-separated OID 82 * path. Will fail if the path names an existing leaf configuration 83 * variable. 84 */ 85 nvlist_t *find_config_node(const char *path); 86 87 /* 88 * Similar to the above, but treats the path relative to an existing 89 * 'parent' node rather than as an absolute path. 90 */ 91 nvlist_t *create_relative_config_node(nvlist_t *parent, const char *path); 92 nvlist_t *find_relative_config_node(nvlist_t *parent, const char *path); 93 94 /* 95 * Adds or replaces the value of the specified variable. 96 * 97 * If 'parent' is NULL, 'name' is assumed to be a top-level variable. 98 */ 99 void set_config_value_node(nvlist_t *parent, const char *name, 100 const char *value); 101 102 /* 103 * Similar to set_config_value_node but only sets value if it's unset yet. 104 */ 105 void set_config_value_node_if_unset(nvlist_t *const parent, 106 const char *const name, const char *const value); 107 108 /* 109 * Similar to set_config_value_node but expects a full path to the 110 * leaf node. 111 */ 112 void set_config_value(const char *path, const char *value); 113 114 /* 115 * Similar to set_config_value but only sets the value if it's unset yet. 116 */ 117 void set_config_value_if_unset(const char *const path, 118 const char *const value); 119 120 /* Convenience wrappers for boolean variables. */ 121 bool get_config_bool(const char *path); 122 bool get_config_bool_node(const nvlist_t *parent, const char *name); 123 bool get_config_bool_default(const char *path, bool def); 124 bool get_config_bool_node_default(const nvlist_t *parent, const char *name, 125 bool def); 126 void set_config_bool(const char *path, bool value); 127 void set_config_bool_node(nvlist_t *parent, const char *name, bool value); 128 129 void dump_config(void); 130 131 #endif /* !__CONFIG_H__ */ 132