1 /*
2 * This file and its contents are supplied under the terms of the
3 * Common Development and Distribution License ("CDDL"), version 1.0.
4 * You may only use this file in accordance with the terms of version
5 * 1.0 of the CDDL.
6 *
7 * A full copy of the text of the CDDL should have accompanied this
8 * source. A copy of the CDDL is also available via the Internet at
9 * http://www.illumos.org/license/CDDL.
10 */
11 /*
12 * Copyright 2020 Toomas Soome <tsoome@me.com>
13 */
14
15 #include <sys/types.h>
16 #include <string.h>
17 #include <libzfs.h>
18 #include <libzfsbootenv.h>
19 #include <sys/zfs_bootenv.h>
20 #include <sys/vdev_impl.h>
21
22 /*
23 * Store device name to zpool label bootenv area.
24 * This call will set bootenv version to VB_NVLIST, if bootenv currently
25 * does contain other version, then old data will be replaced.
26 */
27 int
lzbe_set_boot_device(const char * pool,lzbe_flags_t flag,const char * device)28 lzbe_set_boot_device(const char *pool, lzbe_flags_t flag, const char *device)
29 {
30 libzfs_handle_t *hdl;
31 zpool_handle_t *zphdl;
32 nvlist_t *nv;
33 char *descriptor;
34 uint64_t version;
35 int rv = -1;
36
37 if (pool == NULL || *pool == '\0')
38 return (rv);
39
40 if ((hdl = libzfs_init()) == NULL)
41 return (rv);
42
43 zphdl = zpool_open(hdl, pool);
44 if (zphdl == NULL) {
45 libzfs_fini(hdl);
46 return (rv);
47 }
48
49 switch (flag) {
50 case lzbe_add:
51 rv = zpool_get_bootenv(zphdl, &nv);
52 if (rv == 0) {
53 /*
54 * We got the nvlist, check for version.
55 * if version is missing or is not VB_NVLIST,
56 * create new list.
57 */
58 rv = nvlist_lookup_uint64(nv, BOOTENV_VERSION,
59 &version);
60 if (rv == 0 && version == VB_NVLIST)
61 break;
62
63 /* Drop this nvlist */
64 fnvlist_free(nv);
65 }
66 /* FALLTHROUGH */
67 case lzbe_replace:
68 nv = fnvlist_alloc();
69 break;
70 default:
71 return (rv);
72 }
73
74 /* version is mandatory */
75 fnvlist_add_uint64(nv, BOOTENV_VERSION, VB_NVLIST);
76
77 /*
78 * If device name is empty, remove boot device configuration.
79 */
80 if ((device == NULL || *device == '\0')) {
81 if (nvlist_exists(nv, OS_BOOTONCE))
82 fnvlist_remove(nv, OS_BOOTONCE);
83 } else {
84 /*
85 * Use device name directly if it does start with
86 * prefix "zfs:". Otherwise, add prefix and sufix.
87 */
88 if (strncmp(device, "zfs:", 4) == 0) {
89 fnvlist_add_string(nv, OS_BOOTONCE, device);
90 } else {
91 descriptor = NULL;
92 if (asprintf(&descriptor, "zfs:%s:", device) > 0)
93 fnvlist_add_string(nv, OS_BOOTONCE, descriptor);
94 else
95 rv = ENOMEM;
96 free(descriptor);
97 }
98 }
99
100 rv = zpool_set_bootenv(zphdl, nv);
101 if (rv != 0)
102 fprintf(stderr, "%s\n", libzfs_error_description(hdl));
103
104 fnvlist_free(nv);
105 zpool_close(zphdl);
106 libzfs_fini(hdl);
107 return (rv);
108 }
109
110 /*
111 * Return boot device name from bootenv, if set.
112 */
113 int
lzbe_get_boot_device(const char * pool,char ** device)114 lzbe_get_boot_device(const char *pool, char **device)
115 {
116 libzfs_handle_t *hdl;
117 zpool_handle_t *zphdl;
118 nvlist_t *nv;
119 char *val;
120 int rv = -1;
121
122 if (pool == NULL || *pool == '\0' || device == NULL)
123 return (rv);
124
125 if ((hdl = libzfs_init()) == NULL)
126 return (rv);
127
128 zphdl = zpool_open(hdl, pool);
129 if (zphdl == NULL) {
130 libzfs_fini(hdl);
131 return (rv);
132 }
133
134 rv = zpool_get_bootenv(zphdl, &nv);
135 if (rv == 0) {
136 rv = nvlist_lookup_string(nv, OS_BOOTONCE, &val);
137 if (rv == 0) {
138 /*
139 * zfs device descriptor is in form of "zfs:dataset:",
140 * we only do need dataset name.
141 */
142 if (strncmp(val, "zfs:", 4) == 0) {
143 val += 4;
144 val = strdup(val);
145 if (val != NULL) {
146 size_t len = strlen(val);
147
148 if (val[len - 1] == ':')
149 val[len - 1] = '\0';
150 *device = val;
151 } else {
152 rv = ENOMEM;
153 }
154 } else {
155 rv = EINVAL;
156 }
157 }
158 nvlist_free(nv);
159 }
160
161 zpool_close(zphdl);
162 libzfs_fini(hdl);
163 return (rv);
164 }
165