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
105 retval = ext2fs_open2(device, 0, EXT2_FLAG_64BITS, 0, 0,
106 default_io_manager, &fs);
107 if (retval)
108 return;
109 sb = fs->super;
110
111 if (sb->s_mtime) {
112 tm = sb->s_mtime;
113 if (sb->s_last_mounted[0])
114 printf(_("\tlast mounted on %.*s on %s"),
115 EXT2_LEN_STR(sb->s_last_mounted), ctime(&tm));
116 else
117 printf(_("\tlast mounted on %s"), ctime(&tm));
118 } else if (sb->s_mkfs_time) {
119 tm = sb->s_mkfs_time;
120 printf(_("\tcreated on %s"), ctime(&tm));
121 } else if (sb->s_wtime) {
122 tm = sb->s_wtime;
123 printf(_("\tlast modified on %s"), ctime(&tm));
124 }
125 ext2fs_close_free(&fs);
126 }
127
128 /*
129 * return 1 if there is no partition table, 0 if a partition table is
130 * detected, and -1 on an error.
131 */
132 #ifdef HAVE_BLKID_PROBE_ENABLE_PARTITIONS
check_partition_table(const char * device)133 static int check_partition_table(const char *device)
134 {
135 blkid_probe pr;
136 const char *value;
137 int ret;
138
139 pr = blkid_new_probe_from_filename(device);
140 if (!pr)
141 return -1;
142
143 ret = blkid_probe_enable_partitions(pr, 1);
144 if (ret < 0)
145 goto errout;
146
147 ret = blkid_probe_enable_superblocks(pr, 0);
148 if (ret < 0)
149 goto errout;
150
151 ret = blkid_do_fullprobe(pr);
152 if (ret < 0)
153 goto errout;
154
155 ret = blkid_probe_lookup_value(pr, "PTTYPE", &value, NULL);
156 if (ret == 0)
157 fprintf(stderr, _("Found a %s partition table in %s\n"),
158 value, device);
159 else
160 ret = 1;
161
162 errout:
163 blkid_free_probe(pr);
164 return ret;
165 }
166 #else
check_partition_table(const char * device EXT2FS_ATTR ((unused)))167 static int check_partition_table(const char *device EXT2FS_ATTR((unused)))
168 {
169 return -1;
170 }
171 #endif
172
173 /*
174 * return 1 if the device looks plausible, creating the file if necessary
175 */
check_plausibility(const char * device,int flags,int * ret_is_dev)176 int check_plausibility(const char *device, int flags, int *ret_is_dev)
177 {
178 int fd, ret, is_dev = 0;
179 ext2fs_struct_stat s;
180 int fl = O_RDONLY;
181 blkid_cache cache = NULL;
182 char *fs_type = NULL;
183 char *fs_label = NULL;
184
185 fd = ext2fs_open_file(device, fl, 0666);
186 if ((fd < 0) && (errno == ENOENT) && (flags & NO_SIZE)) {
187 fprintf(stderr, _("The file %s does not exist and no "
188 "size was specified.\n"), device);
189 exit(1);
190 }
191 if ((fd < 0) && (errno == ENOENT) && (flags & CREATE_FILE)) {
192 fl |= O_CREAT;
193 fd = ext2fs_open_file(device, fl, 0666);
194 if (fd >= 0 && (flags & VERBOSE_CREATE))
195 printf(_("Creating regular file %s\n"), device);
196 }
197 if (fd < 0) {
198 fprintf(stderr, _("Could not open %s: %s\n"),
199 device, error_message(errno));
200 if (errno == ENOENT)
201 fputs(_("\nThe device apparently does not exist; "
202 "did you specify it correctly?\n"), stderr);
203 exit(1);
204 }
205
206 if (ext2fs_fstat(fd, &s) < 0) {
207 perror("stat");
208 exit(1);
209 }
210 close(fd);
211
212 if (S_ISBLK(s.st_mode))
213 is_dev = 1;
214 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
215 /* On FreeBSD, all disk devices are character specials */
216 if (S_ISCHR(s.st_mode))
217 is_dev = 1;
218 #endif
219 if (ret_is_dev)
220 *ret_is_dev = is_dev;
221
222 if ((flags & CHECK_BLOCK_DEV) && !is_dev) {
223 printf(_("%s is not a block special device.\n"), device);
224 return 0;
225 }
226
227 /*
228 * Note: we use the older-style blkid API's here because we
229 * want as much functionality to be available when using the
230 * internal blkid library, when e2fsprogs is compiled for
231 * non-Linux systems that will probably not have the libraries
232 * from util-linux available. We only use the newer
233 * blkid-probe interfaces to access functionality not
234 * available in the original blkid library.
235 */
236 if ((flags & CHECK_FS_EXIST) && blkid_get_cache(&cache, NULL) >= 0) {
237 fs_type = blkid_get_tag_value(cache, "TYPE", device);
238 if (fs_type)
239 fs_label = blkid_get_tag_value(cache, "LABEL", device);
240 blkid_put_cache(cache);
241 }
242
243 if (fs_type) {
244 if (fs_label)
245 printf(_("%s contains a %s file system labelled '%s'\n"),
246 device, fs_type, fs_label);
247 else
248 printf(_("%s contains a %s file system\n"), device,
249 fs_type);
250 if (strncmp(fs_type, "ext", 3) == 0)
251 print_ext2_info(device);
252 free(fs_type);
253 free(fs_label);
254 return 0;
255 }
256
257 #ifdef HAVE_MAGIC_H
258 if ((flags & CHECK_FS_EXIST) &&
259 !getenv("E2FSPROGS_LIBMAGIC_SUPPRESS") &&
260 magic_library_available()) {
261 const char *msg;
262 magic_t mag;
263 int has_magic = 0;
264
265 mag = dl_magic_open(MAGIC_RAW | MAGIC_SYMLINK | MAGIC_DEVICES |
266 MAGIC_ERROR | MAGIC_NO_CHECK_ELF |
267 MAGIC_NO_CHECK_COMPRESS);
268 dl_magic_load(mag, NULL);
269
270 msg = dl_magic_file(mag, device);
271 if (msg && strcmp(msg, "data") && strcmp(msg, "empty")) {
272 printf(_("%s contains `%s' data\n"), device, msg);
273 has_magic = 1;
274 }
275
276 dl_magic_close(mag);
277 return !has_magic;
278 }
279 #endif
280 if (flags & CHECK_FS_EXIST) {
281 ret = check_partition_table(device);
282 if (ret >= 0)
283 return ret;
284 }
285 return 1;
286 }
287
288