1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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 28 #ifndef __CONFIG_H__ 29 #define __CONFIG_H__ 30 31 #include <sys/nv.h> 32 33 /*- 34 * Manages a configuration database backed by an nv(9) list. 35 * 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. 42 * 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) 45 * OIDs. 46 */ 47 48 /* 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 53 * this function. 54 * 55 * If no node is found, returns NULL. 56 * 57 * If 'parent' is NULL, 'name' is assumed to be a top-level variable. 58 */ 59 const char *get_config_value_node(const nvlist_t *parent, const char *name); 60 61 /* 62 * Similar to get_config_value_node but expects a full path to the 63 * leaf node. 64 */ 65 const char *get_config_value(const char *path); 66 67 /* Initializes the tree to an empty state. */ 68 void init_config(void); 69 70 /* 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 74 * the existing node. 75 */ 76 nvlist_t *create_config_node(const char *path); 77 78 /* 79 * Looks for an existing configuration node via a dot-separated OID 80 * path. Will fail if the path names an existing leaf configuration 81 * variable. 82 */ 83 nvlist_t *find_config_node(const char *path); 84 85 /* 86 * Similar to the above, but treats the path relative to an existing 87 * 'parent' node rather than as an absolute path. 88 */ 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); 91 92 /* 93 * Adds or replaces the value of the specified variable. 94 * 95 * If 'parent' is NULL, 'name' is assumed to be a top-level variable. 96 */ 97 void set_config_value_node(nvlist_t *parent, const char *name, 98 const char *value); 99 100 /* 101 * Similar to set_config_value_node but only sets value if it's unset yet. 102 */ 103 void set_config_value_node_if_unset(nvlist_t *const parent, 104 const char *const name, const char *const value); 105 106 /* 107 * Similar to set_config_value_node but expects a full path to the 108 * leaf node. 109 */ 110 void set_config_value(const char *path, const char *value); 111 112 /* 113 * Similar to set_config_value but only sets the value if it's unset yet. 114 */ 115 void set_config_value_if_unset(const char *const path, 116 const char *const value); 117 118 /* 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, 123 bool def); 124 void set_config_bool(const char *path, bool value); 125 void set_config_bool_node(nvlist_t *parent, const char *name, bool value); 126 127 void dump_config(void); 128 129 #endif /* !__CONFIG_H__ */ 130