1 /*
2 * plausible.c --- Figure out if a pathname is ext* or something else.
3 *
4 * Copyright 2014, Oracle, Inc.
5 *
6 * Some parts are:
7 * Copyright 1995, 1996, 1997, 1998, 1999, 2000 by Theodore Ts'o.
8 *
9 * %Begin-Header%
10 * This file may be redistributed under the terms of the GNU Public
11 * License.
12 * %End-Header%
13 */
14
15 #ifndef _LARGEFILE_SOURCE
16 #define _LARGEFILE_SOURCE
17 #endif
18 #ifndef _LARGEFILE64_SOURCE
19 #define _LARGEFILE64_SOURCE
20 #endif
21
22 #include "config.h"
23 #include <fcntl.h>
24 #include <time.h>
25 #include <sys/types.h>
26 #ifdef HAVE_SYS_STAT_H
27 #include <sys/stat.h>
28 #endif
29 #ifdef HAVE_UNISTD_H
30 #include <unistd.h>
31 #endif
32 #ifdef HAVE_MAGIC_H
33 #include <magic.h>
34 #endif
35 #include "plausible.h"
36 #include "ext2fs/ext2fs.h"
37 #include "nls-enable.h"
38 #include "blkid/blkid.h"
39
40 #ifdef HAVE_MAGIC_H
41 static magic_t (*dl_magic_open)(int);
42 static const char *(*dl_magic_file)(magic_t, const char *);
43 static int (*dl_magic_load)(magic_t, const char *);
44 static void (*dl_magic_close)(magic_t);
45
46 /*
47 * NO_CHECK functionality was only added in file 4.20.
48 * Older systems like RHEL 5.x still have file 4.17
49 */
50 #ifndef MAGIC_NO_CHECK_COMPRESS
51 #define MAGIC_NO_CHECK_COMPRESS 0x0001000
52 #endif
53 #ifndef MAGIC_NO_CHECK_ELF
54 #define MAGIC_NO_CHECK_ELF 0x0010000
55 #endif
56
57 #ifdef HAVE_DLOPEN
58 #include <dlfcn.h>
59
60 static void *magic_handle;
61
magic_library_available(void)62 static int magic_library_available(void)
63 {
64 if (!magic_handle) {
65 magic_handle = dlopen("libmagic.so.1", RTLD_NOW);
66 if (!magic_handle)
67 return 0;
68
69 dl_magic_open = (magic_t (*)(int))
70 dlsym(magic_handle, "magic_open");
71 dl_magic_file = (const char *(*)(magic_t, const char *))
72 dlsym(magic_handle, "magic_file");
73 dl_magic_load = (int (*)(magic_t, const char *))
74 dlsym(magic_handle, "magic_load");
75 dl_magic_close = (void (*)(magic_t))
76 dlsym(magic_handle, "magic_close");
77 }
78
79 if (!dl_magic_open || !dl_magic_file ||
80 !dl_magic_load || !dl_magic_close)
81 return 0;
82 return 1;
83 }
84 #else
magic_library_available(void)85 static int magic_library_available(void)
86 {
87 dl_magic_open = magic_open;
88 dl_magic_file = magic_file;
89 dl_magic_load = magic_load;
90 dl_magic_close = magic_close;
91
92 return 1;
93 }
94 #endif
95 #endif
96
print_ext2_info(const char * device)97 static void print_ext2_info(const char *device)
98
99 {
100 struct ext2_super_block *sb;
101 ext2_filsys fs;
102 errcode_t retval;
103 time_t tm;
104 char buf[80];
105
106 retval = ext2fs_open2(device, 0, EXT2_FLAG_64BITS, 0, 0,
107 unix_io_manager, &fs);
108 if (retval)
109 return;
110 sb = fs->super;
111
112 if (sb->s_mtime) {
113 tm = sb->s_mtime;
114 if (sb->s_last_mounted[0]) {
115 memset(buf, 0, sizeof(buf));
116 strncpy(buf, sb->s_last_mounted,
117 sizeof(sb->s_last_mounted));
118 printf(_("\tlast mounted on %s on %s"), buf,
119 ctime(&tm));
120 } else
121 printf(_("\tlast mounted on %s"), ctime(&tm));
122 } else if (sb->s_mkfs_time) {
123 tm = sb->s_mkfs_time;
124 printf(_("\tcreated on %s"), ctime(&tm));
125 } else if (sb->s_wtime) {
126 tm = sb->s_wtime;
127 printf(_("\tlast modified on %s"), ctime(&tm));
128 }
129 ext2fs_close_free(&fs);
130 }
131
132 /*
133 * return 1 if there is no partition table, 0 if a partition table is
134 * detected, and -1 on an error.
135 */
136 #ifdef HAVE_BLKID_PROBE_ENABLE_PARTITIONS
check_partition_table(const char * device)137 static int check_partition_table(const char *device)
138 {
139 blkid_probe pr;
140 const char *value;
141 int ret;
142
143 pr = blkid_new_probe_from_filename(device);
144 if (!pr)
145 return -1;
146
147 ret = blkid_probe_enable_partitions(pr, 1);
148 if (ret < 0)
149 goto errout;
150
151 ret = blkid_probe_enable_superblocks(pr, 0);
152 if (ret < 0)
153 goto errout;
154
155 ret = blkid_do_fullprobe(pr);
156 if (ret < 0)
157 goto errout;
158
159 ret = blkid_probe_lookup_value(pr, "PTTYPE", &value, NULL);
160 if (ret == 0)
161 fprintf(stderr, _("Found a %s partition table in %s\n"),
162 value, device);
163 else
164 ret = 1;
165
166 errout:
167 blkid_free_probe(pr);
168 return ret;
169 }
170 #else
check_partition_table(const char * device EXT2FS_ATTR ((unused)))171 static int check_partition_table(const char *device EXT2FS_ATTR((unused)))
172 {
173 return -1;
174 }
175 #endif
176
177 /*
178 * return 1 if the device looks plausible, creating the file if necessary
179 */
check_plausibility(const char * device,int flags,int * ret_is_dev)180 int check_plausibility(const char *device, int flags, int *ret_is_dev)
181 {
182 int fd, ret, is_dev = 0;
183 ext2fs_struct_stat s;
184 int fl = O_RDONLY;
185 blkid_cache cache = NULL;
186 char *fs_type = NULL;
187 char *fs_label = NULL;
188
189 fd = ext2fs_open_file(device, fl, 0666);
190 if ((fd < 0) && (errno == ENOENT) && (flags & NO_SIZE)) {
191 fprintf(stderr, _("The file %s does not exist and no "
192 "size was specified.\n"), device);
193 exit(1);
194 }
195 if ((fd < 0) && (errno == ENOENT) && (flags & CREATE_FILE)) {
196 fl |= O_CREAT;
197 fd = ext2fs_open_file(device, fl, 0666);
198 if (fd >= 0 && (flags & VERBOSE_CREATE))
199 printf(_("Creating regular file %s\n"), device);
200 }
201 if (fd < 0) {
202 fprintf(stderr, _("Could not open %s: %s\n"),
203 device, error_message(errno));
204 if (errno == ENOENT)
205 fputs(_("\nThe device apparently does not exist; "
206 "did you specify it correctly?\n"), stderr);
207 exit(1);
208 }
209
210 if (ext2fs_fstat(fd, &s) < 0) {
211 perror("stat");
212 exit(1);
213 }
214 close(fd);
215
216 if (S_ISBLK(s.st_mode))
217 is_dev = 1;
218 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
219 /* On FreeBSD, all disk devices are character specials */
220 if (S_ISCHR(s.st_mode))
221 is_dev = 1;
222 #endif
223 if (ret_is_dev)
224 *ret_is_dev = is_dev;
225
226 if ((flags & CHECK_BLOCK_DEV) && !is_dev) {
227 printf(_("%s is not a block special device.\n"), device);
228 return 0;
229 }
230
231 /*
232 * Note: we use the older-style blkid API's here because we
233 * want as much functionality to be available when using the
234 * internal blkid library, when e2fsprogs is compiled for
235 * non-Linux systems that will probably not have the libraries
236 * from util-linux available. We only use the newer
237 * blkid-probe interfaces to access functionality not
238 * available in the original blkid library.
239 */
240 if ((flags & CHECK_FS_EXIST) && blkid_get_cache(&cache, NULL) >= 0) {
241 fs_type = blkid_get_tag_value(cache, "TYPE", device);
242 if (fs_type)
243 fs_label = blkid_get_tag_value(cache, "LABEL", device);
244 blkid_put_cache(cache);
245 }
246
247 if (fs_type) {
248 if (fs_label)
249 printf(_("%s contains a %s file system labelled '%s'\n"),
250 device, fs_type, fs_label);
251 else
252 printf(_("%s contains a %s file system\n"), device,
253 fs_type);
254 if (strncmp(fs_type, "ext", 3) == 0)
255 print_ext2_info(device);
256 free(fs_type);
257 free(fs_label);
258 return 0;
259 }
260
261 #ifdef HAVE_MAGIC_H
262 if ((flags & CHECK_FS_EXIST) &&
263 !getenv("E2FSPROGS_LIBMAGIC_SUPPRESS") &&
264 magic_library_available()) {
265 const char *msg;
266 magic_t mag;
267 int has_magic = 0;
268
269 mag = dl_magic_open(MAGIC_RAW | MAGIC_SYMLINK | MAGIC_DEVICES |
270 MAGIC_ERROR | MAGIC_NO_CHECK_ELF |
271 MAGIC_NO_CHECK_COMPRESS);
272 dl_magic_load(mag, NULL);
273
274 msg = dl_magic_file(mag, device);
275 if (msg && strcmp(msg, "data") && strcmp(msg, "empty")) {
276 printf(_("%s contains `%s' data\n"), device, msg);
277 has_magic = 1;
278 }
279
280 dl_magic_close(mag);
281 return !has_magic;
282 }
283 #endif
284
285 ret = check_partition_table(device);
286 if (ret >= 0)
287 return ret;
288
289 return 1;
290 }
291
292