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 #include <stdbool.h> 47 #include <sys/queue.h> 48 #include "stand.h" 49 #include "nvstore.h" 50 51 nvstore_list_t stores = STAILQ_HEAD_INITIALIZER(stores); 52 53 void * 54 nvstore_get_store(const char *name) 55 { 56 nvstore_t *st; 57 58 st = NULL; 59 60 STAILQ_FOREACH(st, &stores, nvs_next) { 61 if (strcmp(name, st->nvs_name) == 0) 62 break; 63 } 64 65 return (st); 66 } 67 68 int 69 nvstore_init(const char *name, nvs_callbacks_t *cb, void *data) 70 { 71 nvstore_t *st; 72 73 st = nvstore_get_store(name); 74 if (st != NULL) 75 return (EEXIST); 76 77 if ((st = malloc(sizeof (*st))) == NULL) 78 return (ENOMEM); 79 80 if ((st->nvs_name = strdup(name)) == NULL) { 81 free(st); 82 return (ENOMEM); 83 } 84 85 st->nvs_data = data; 86 st->nvs_cb = cb; 87 88 STAILQ_INSERT_TAIL(&stores, st, nvs_next); 89 return (0); 90 } 91 92 int 93 nvstore_fini(const char *name) 94 { 95 nvstore_t *st; 96 97 st = nvstore_get_store(name); 98 if (st == NULL) 99 return (ENOENT); 100 101 STAILQ_REMOVE(&stores, st, nvstore, nvs_next); 102 103 free(st->nvs_name); 104 free(st->nvs_data); 105 free(st); 106 return (0); 107 } 108 109 int 110 nvstore_print(void *ptr) 111 { 112 nvstore_t *st = ptr; 113 114 return (st->nvs_cb->nvs_iterate(st->nvs_data, st->nvs_cb->nvs_print)); 115 } 116 117 int 118 nvstore_get_var(void *ptr, const char *name, void **data) 119 { 120 nvstore_t *st = ptr; 121 122 return (st->nvs_cb->nvs_getter(st->nvs_data, name, data)); 123 } 124 125 int 126 nvstore_set_var(void *ptr, int type, const char *name, 127 void *data, size_t size) 128 { 129 nvstore_t *st = ptr; 130 131 return (st->nvs_cb->nvs_setter(st->nvs_data, type, name, data, size)); 132 } 133 134 int 135 nvstore_set_var_from_string(void *ptr, const char *type, const char *name, 136 const char *data) 137 { 138 nvstore_t *st = ptr; 139 140 return (st->nvs_cb->nvs_setter_str(st->nvs_data, type, name, data)); 141 } 142 143 int 144 nvstore_unset_var(void *ptr, const char *name) 145 { 146 nvstore_t *st = ptr; 147 148 return (st->nvs_cb->nvs_unset(st->nvs_data, name)); 149 } 150