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