1 /*
2 * cache.c - allocation/initialization/free routines for cache
3 *
4 * Copyright (C) 2001 Andreas Dilger
5 * Copyright (C) 2003 Theodore Ts'o
6 *
7 * %Begin-Header%
8 * This file may be redistributed under the terms of the
9 * GNU Lesser General Public License.
10 * %End-Header%
11 */
12
13 #include "config.h"
14 #if HAVE_UNISTD_H
15 #include <unistd.h>
16 #endif
17 #ifdef HAVE_ERRNO_H
18 #include <errno.h>
19 #endif
20 #include <stdlib.h>
21 #include <string.h>
22 #ifdef HAVE_SYS_PRCTL_H
23 #include <sys/prctl.h>
24 #else
25 #define PR_GET_DUMPABLE 3
26 #endif
27 #if (!defined(HAVE_PRCTL) && defined(linux))
28 #include <sys/syscall.h>
29 #endif
30 #ifdef HAVE_SYS_STAT_H
31 #include <sys/stat.h>
32 #endif
33 #include "blkidP.h"
34
35 int blkid_debug_mask = 0;
36
37
safe_getenv(const char * arg)38 static char *safe_getenv(const char *arg)
39 {
40 if ((getuid() != geteuid()) || (getgid() != getegid()))
41 return NULL;
42 #if HAVE_PRCTL
43 if (prctl(PR_GET_DUMPABLE, 0, 0, 0, 0) == 0)
44 return NULL;
45 #else
46 #if (defined(linux) && defined(SYS_prctl))
47 if (syscall(SYS_prctl, PR_GET_DUMPABLE, 0, 0, 0, 0) == 0)
48 return NULL;
49 #endif
50 #endif
51
52 #if defined(HAVE_SECURE_GETENV)
53 return secure_getenv(arg);
54 #elif defined(HAVE___SECURE_GETENV)
55 return __secure_getenv(arg);
56 #else
57 return getenv(arg);
58 #endif
59 }
60
61 #if 0 /* ifdef CONFIG_BLKID_DEBUG */
62 static blkid_debug_dump_cache(int mask, blkid_cache cache)
63 {
64 struct list_head *p;
65
66 if (!cache) {
67 printf("cache: NULL\n");
68 return;
69 }
70
71 printf("cache: time = %lu\n", cache->bic_time);
72 printf("cache: flags = 0x%08X\n", cache->bic_flags);
73
74 list_for_each(p, &cache->bic_devs) {
75 blkid_dev dev = list_entry(p, struct blkid_struct_dev, bid_devs);
76 blkid_debug_dump_dev(dev);
77 }
78 }
79 #endif
80
blkid_get_cache(blkid_cache * ret_cache,const char * filename)81 int blkid_get_cache(blkid_cache *ret_cache, const char *filename)
82 {
83 blkid_cache cache;
84
85 #ifdef CONFIG_BLKID_DEBUG
86 if (!(blkid_debug_mask & DEBUG_INIT)) {
87 char *dstr = getenv("BLKID_DEBUG");
88
89 if (dstr)
90 blkid_debug_mask = strtoul(dstr, 0, 0);
91 blkid_debug_mask |= DEBUG_INIT;
92 }
93 #endif
94
95 DBG(DEBUG_CACHE, printf("creating blkid cache (using %s)\n",
96 filename ? filename : "default cache"));
97
98 if (!(cache = (blkid_cache) calloc(1, sizeof(struct blkid_struct_cache))))
99 return -BLKID_ERR_MEM;
100
101 INIT_LIST_HEAD(&cache->bic_devs);
102 INIT_LIST_HEAD(&cache->bic_tags);
103
104 if (filename && !strlen(filename))
105 filename = 0;
106 if (!filename)
107 filename = safe_getenv("BLKID_FILE");
108 if (!filename)
109 filename = BLKID_CACHE_FILE;
110 cache->bic_filename = blkid_strdup(filename);
111
112 blkid_read_cache(cache);
113
114 *ret_cache = cache;
115 return 0;
116 }
117
blkid_put_cache(blkid_cache cache)118 void blkid_put_cache(blkid_cache cache)
119 {
120 if (!cache)
121 return;
122
123 (void) blkid_flush_cache(cache);
124
125 DBG(DEBUG_CACHE, printf("freeing cache struct\n"));
126
127 /* DBG(DEBUG_CACHE, blkid_debug_dump_cache(cache)); */
128
129 while (!list_empty(&cache->bic_devs)) {
130 blkid_dev dev = list_entry(cache->bic_devs.next,
131 struct blkid_struct_dev,
132 bid_devs);
133 blkid_free_dev(dev);
134 }
135
136 while (!list_empty(&cache->bic_tags)) {
137 blkid_tag tag = list_entry(cache->bic_tags.next,
138 struct blkid_struct_tag,
139 bit_tags);
140
141 while (!list_empty(&tag->bit_names)) {
142 blkid_tag bad = list_entry(tag->bit_names.next,
143 struct blkid_struct_tag,
144 bit_names);
145
146 DBG(DEBUG_CACHE, printf("warning: unfreed tag %s=%s\n",
147 bad->bit_name, bad->bit_val));
148 blkid_free_tag(bad);
149 }
150 blkid_free_tag(tag);
151 }
152 free(cache->bic_filename);
153
154 free(cache);
155 }
156
blkid_gc_cache(blkid_cache cache)157 void blkid_gc_cache(blkid_cache cache)
158 {
159 struct list_head *p, *pnext;
160 struct stat st;
161
162 if (!cache)
163 return;
164
165 list_for_each_safe(p, pnext, &cache->bic_devs) {
166 blkid_dev dev = list_entry(p, struct blkid_struct_dev, bid_devs);
167 if (stat(dev->bid_name, &st) < 0) {
168 DBG(DEBUG_CACHE,
169 printf("freeing %s\n", dev->bid_name));
170 blkid_free_dev(dev);
171 cache->bic_flags |= BLKID_BIC_FL_CHANGED;
172 } else {
173 DBG(DEBUG_CACHE,
174 printf("Device %s exists\n", dev->bid_name));
175 }
176 }
177 }
178
179
180 #ifdef TEST_PROGRAM
main(int argc,char ** argv)181 int main(int argc, char** argv)
182 {
183 blkid_cache cache = NULL;
184 int ret;
185
186 blkid_debug_mask = DEBUG_ALL;
187 if ((argc > 2)) {
188 fprintf(stderr, "Usage: %s [filename] \n", argv[0]);
189 exit(1);
190 }
191
192 if ((ret = blkid_get_cache(&cache, argv[1])) < 0) {
193 fprintf(stderr, "error %d parsing cache file %s\n", ret,
194 argv[1] ? argv[1] : BLKID_CACHE_FILE);
195 exit(1);
196 }
197 if ((ret = blkid_get_cache(&cache, "/dev/null")) != 0) {
198 fprintf(stderr, "%s: error creating cache (%d)\n",
199 argv[0], ret);
200 exit(1);
201 }
202 if ((ret = blkid_probe_all(cache) < 0))
203 fprintf(stderr, "error probing devices\n");
204
205 blkid_put_cache(cache);
206
207 return ret;
208 }
209 #endif
210