blob: 295ca61bffff3aac6e4f20d73d08757862471137
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * resolve.c - resolve names and tags into specific devices |
4 | * |
5 | * Copyright (C) 2001, 2003 Theodore Ts'o. |
6 | * Copyright (C) 2001 Andreas Dilger |
7 | * |
8 | * %Begin-Header% |
9 | * This file may be redistributed under the terms of the |
10 | * GNU Lesser General Public License. |
11 | * %End-Header% |
12 | */ |
13 | |
14 | #include <stdio.h> |
15 | #ifdef HAVE_UNISTD_H |
16 | #include <unistd.h> |
17 | #endif |
18 | #include <stdlib.h> |
19 | #include <fcntl.h> |
20 | #include <string.h> |
21 | #include <sys/types.h> |
22 | #include <sys/stat.h> |
23 | #include "blkidP.h" |
24 | #include "probe.h" |
25 | |
26 | /* |
27 | * Find a tagname (e.g. LABEL or UUID) on a specific device. |
28 | */ |
29 | char *blkid_get_tag_value(blkid_cache cache, const char *tagname, |
30 | const char *devname) |
31 | { |
32 | blkid_tag found; |
33 | blkid_dev dev; |
34 | blkid_cache c = cache; |
35 | char *ret = NULL; |
36 | |
37 | DBG(DEBUG_RESOLVE, printf("looking for %s on %s\n", tagname, devname)); |
38 | |
39 | if (!devname) |
40 | return NULL; |
41 | |
42 | if (!cache) { |
43 | if (blkid_get_cache(&c, NULL) < 0) |
44 | return NULL; |
45 | } |
46 | |
47 | if ((dev = blkid_get_dev(c, devname, BLKID_DEV_NORMAL)) && |
48 | (found = blkid_find_tag_dev(dev, tagname))) |
49 | ret = blkid_strdup(found->bit_val); |
50 | |
51 | if (!cache) |
52 | blkid_put_cache(c); |
53 | |
54 | return ret; |
55 | } |
56 | |
57 | /* |
58 | * Locate a device name from a token (NAME=value string), or (name, value) |
59 | * pair. In the case of a token, value is ignored. If the "token" is not |
60 | * of the form "NAME=value" and there is no value given, then it is assumed |
61 | * to be the actual devname and a copy is returned. |
62 | */ |
63 | char *blkid_get_devname(blkid_cache cache, const char *token, |
64 | const char *value) |
65 | { |
66 | blkid_dev dev; |
67 | blkid_cache c = cache; |
68 | char *t = NULL, *v = NULL; |
69 | char *ret = NULL; |
70 | |
71 | if (!token) |
72 | return NULL; |
73 | |
74 | if (!cache) { |
75 | if (blkid_get_cache(&c, NULL) < 0) |
76 | return NULL; |
77 | } |
78 | |
79 | DBG(DEBUG_RESOLVE, |
80 | printf("looking for %s%s%s %s\n", token, value ? "=" : "", |
81 | value ? value : "", cache ? "in cache" : "from disk")); |
82 | |
83 | if (!value) { |
84 | if (!strchr(token, '=')) |
85 | return blkid_strdup(token); |
86 | blkid_parse_tag_string(token, &t, &v); |
87 | if (!t || !v) |
88 | goto errout; |
89 | token = t; |
90 | value = v; |
91 | } |
92 | |
93 | dev = blkid_find_dev_with_tag(c, token, value); |
94 | if (!dev) |
95 | goto errout; |
96 | |
97 | ret = blkid_strdup(blkid_dev_devname(dev)); |
98 | |
99 | errout: |
100 | free(t); |
101 | free(v); |
102 | if (!cache) { |
103 | blkid_put_cache(c); |
104 | } |
105 | return ret; |
106 | } |
107 | |
108 | #ifdef TEST_PROGRAM |
109 | int main(int argc, char **argv) |
110 | { |
111 | char *value; |
112 | blkid_cache cache; |
113 | |
114 | blkid_debug_mask = DEBUG_ALL; |
115 | if (argc != 2 && argc != 3) { |
116 | fprintf(stderr, "Usage:\t%s tagname=value\n" |
117 | "\t%s tagname devname\n" |
118 | "Find which device holds a given token or\n" |
119 | "Find what the value of a tag is in a device\n", |
120 | argv[0], argv[0]); |
121 | exit(1); |
122 | } |
123 | if (blkid_get_cache(&cache, bb_dev_null) < 0) { |
124 | fprintf(stderr, "Can't get blkid cache\n"); |
125 | exit(1); |
126 | } |
127 | |
128 | if (argv[2]) { |
129 | value = blkid_get_tag_value(cache, argv[1], argv[2]); |
130 | printf("%s has tag %s=%s\n", argv[2], argv[1], |
131 | value ? value : "<missing>"); |
132 | } else { |
133 | value = blkid_get_devname(cache, argv[1], NULL); |
134 | printf("%s has tag %s\n", value ? value : "<none>", argv[1]); |
135 | } |
136 | blkid_put_cache(cache); |
137 | return value ? 0 : 1; |
138 | } |
139 | #endif |
140 |