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 *
nvstore_get_store(const char * name)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
nvstore_init(const char * name,nvs_callbacks_t * cb,void * data)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
nvstore_fini(const char * name)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
nvstore_print(void * ptr)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
nvstore_get_var(void * ptr,const char * name,void ** data)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
nvstore_set_var(void * ptr,int type,const char * name,void * data,size_t size)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
nvstore_set_var_from_string(void * ptr,const char * type,const char * name,const char * data)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
nvstore_unset_var(void * ptr,const char * name)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