usr/src/cmd/bhyve/config.h

   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__ */