1 /*- 2 * Copyright 2020 Toomas Soome <tsoome@me.com> 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23 * SUCH DAMAGE. 24 */ 25 26 /* 27 * Big Theory Statement. 28 * 29 * nvstore is abstraction layer to implement data read/write to different 30 * types of non-volatile storage. 31 * 32 * User interfaces: 33 * Provide mapping via environment: setenv/unsetenv/putenv. Access via 34 * environment functions/commands is available once nvstore has 35 * attached the backend and stored textual data is mapped to environment. 36 * 37 * nvstore_init(): attach new backend and create the environment mapping. 38 * nvstore_fini: detach backend and unmap the related environment. 39 * 40 * The disk based storage, such as UFS file or ZFS bootenv label area, is 41 * only accessible after root file system is set. Root file system change 42 * will switch the back end storage. 43 */ 44 45 #include <sys/cdefs.h> 46 __FBSDID("$FreeBSD$"); 47 48 #include <stdbool.h> 49 #include <sys/queue.h> 50 #include "stand.h" 51 #include "nvstore.h" 52 53 nvstore_list_t stores = STAILQ_HEAD_INITIALIZER(stores); 54 55 void * 56 nvstore_get_store(const char *name) 57 { 58 nvstore_t *st; 59 60 st = NULL; 61 62 STAILQ_FOREACH(st, &stores, nvs_next) { 63 if (strcmp(name, st->nvs_name) == 0) 64 break; 65 } 66 67 return (st); 68 } 69 70 int 71 nvstore_init(const char *name, nvs_callbacks_t *cb, void *data) 72 { 73 nvstore_t *st; 74 75 st = nvstore_get_store(name); 76 if (st != NULL) 77 return (EEXIST); 78 79 if ((st = malloc(sizeof (*st))) == NULL) 80 return (ENOMEM); 81 82 if ((st->nvs_name = strdup(name)) == NULL) { 83 free(st); 84 return (ENOMEM); 85 } 86 87 st->nvs_data = data; 88 st->nvs_cb = cb; 89 90 STAILQ_INSERT_TAIL(&stores, st, nvs_next); 91 return (0); 92 } 93 94 int 95 nvstore_fini(const char *name) 96 { 97 nvstore_t *st; 98 99 st = nvstore_get_store(name); 100 if (st == NULL) 101 return (ENOENT); 102 103 STAILQ_REMOVE(&stores, st, nvstore, nvs_next); 104 105 free(st->nvs_name); 106 free(st->nvs_data); 107 free(st); 108 return (0); 109 } 110 111 int 112 nvstore_print(void *ptr) 113 { 114 nvstore_t *st = ptr; 115 116 return (st->nvs_cb->nvs_iterate(st->nvs_data, st->nvs_cb->nvs_print)); 117 } 118 119 int 120 nvstore_get_var(void *ptr, const char *name, void **data) 121 { 122 nvstore_t *st = ptr; 123 124 return (st->nvs_cb->nvs_getter(st->nvs_data, name, data)); 125 } 126 127 int 128 nvstore_set_var(void *ptr, int type, const char *name, 129 void *data, size_t size) 130 { 131 nvstore_t *st = ptr; 132 133 return (st->nvs_cb->nvs_setter(st->nvs_data, type, name, data, size)); 134 } 135 136 int 137 nvstore_set_var_from_string(void *ptr, const char *type, const char *name, 138 const char *data) 139 { 140 nvstore_t *st = ptr; 141 142 return (st->nvs_cb->nvs_setter_str(st->nvs_data, type, name, data)); 143 } 144 145 int 146 nvstore_unset_var(void *ptr, const char *name) 147 { 148 nvstore_t *st = ptr; 149 150 return (st->nvs_cb->nvs_unset(st->nvs_data, name)); 151 } 152