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 #ifdef _WIN64
107 windows_io_manager,
108 #else
109 unix_io_manager,
110 #endif
111 &fs);
112 if (retval)
113 return;
114 sb = fs->super;
115
116 if (sb->s_mtime) {
117 tm = sb->s_mtime;
118 if (sb->s_last_mounted[0])
119 printf(_("\tlast mounted on %.*s on %s"),
120 EXT2_LEN_STR(sb->s_last_mounted), ctime(&tm));
121 else
122 printf(_("\tlast mounted on %s"), ctime(&tm));
123 } else if (sb->s_mkfs_time) {
124 tm = sb->s_mkfs_time;
125 printf(_("\tcreated on %s"), ctime(&tm));
126 } else if (sb->s_wtime) {
127 tm = sb->s_wtime;
128 printf(_("\tlast modified on %s"), ctime(&tm));
129 }
130 ext2fs_close_free(&fs);
131 }
132
133 /*
134 * return 1 if there is no partition table, 0 if a partition table is
135 * detected, and -1 on an error.
136 */
137 #ifdef HAVE_BLKID_PROBE_ENABLE_PARTITIONS
check_partition_table(const char * device)138 static int check_partition_table(const char *device)
139 {
140 blkid_probe pr;
141 const char *value;
142 int ret;
143
144 pr = blkid_new_probe_from_filename(device);
145 if (!pr)
146 return -1;
147
148 ret = blkid_probe_enable_partitions(pr, 1);
149 if (ret < 0)
150 goto errout;
151
152 ret = blkid_probe_enable_superblocks(pr, 0);
153 if (ret < 0)
154 goto errout;
155
156 ret = blkid_do_fullprobe(pr);
157 if (ret < 0)
158 goto errout;
159
160 ret = blkid_probe_lookup_value(pr, "PTTYPE", &value, NULL);
161 if (ret == 0)
162 fprintf(stderr, _("Found a %s partition table in %s\n"),
163 value, device);
164 else
165 ret = 1;
166
167 errout:
168 blkid_free_probe(pr);
169 return ret;
170 }
171 #else
check_partition_table(const char * device EXT2FS_ATTR ((unused)))172 static int check_partition_table(const char *device EXT2FS_ATTR((unused)))
173 {
174 return -1;
175 }
176 #endif
177
178 /*
179 * return 1 if the device looks plausible, creating the file if necessary
180 */
check_plausibility(const char * device,int flags,int * ret_is_dev)181 int check_plausibility(const char *device, int flags, int *ret_is_dev)
182 {
183 int fd, ret, is_dev = 0;
184 ext2fs_struct_stat s;
185 int fl = O_RDONLY;
186 blkid_cache cache = NULL;
187 char *fs_type = NULL;
188 char *fs_label = NULL;
189
190 fd = ext2fs_open_file(device, fl, 0666);
191 if ((fd < 0) && (errno == ENOENT) && (flags & NO_SIZE)) {
192 fprintf(stderr, _("The file %s does not exist and no "
193 "size was specified.\n"), device);
194 exit(1);
195 }
196 if ((fd < 0) && (errno == ENOENT) && (flags & CREATE_FILE)) {
197 fl |= O_CREAT;
198 fd = ext2fs_open_file(device, fl, 0666);
199 if (fd >= 0 && (flags & VERBOSE_CREATE))
200 printf(_("Creating regular file %s\n"), device);
201 }
202 if (fd < 0) {
203 fprintf(stderr, _("Could not open %s: %s\n"),
204 device, error_message(errno));
205 if (errno == ENOENT)
206 fputs(_("\nThe device apparently does not exist; "
207 "did you specify it correctly?\n"), stderr);
208 exit(1);
209 }
210
211 if (ext2fs_fstat(fd, &s) < 0) {
212 perror("stat");
213 exit(1);
214 }
215 close(fd);
216
217 if (S_ISBLK(s.st_mode))
218 is_dev = 1;
219 #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
220 /* On FreeBSD, all disk devices are character specials */
221 if (S_ISCHR(s.st_mode))
222 is_dev = 1;
223 #endif
224 if (ret_is_dev)
225 *ret_is_dev = is_dev;
226
227 if ((flags & CHECK_BLOCK_DEV) && !is_dev) {
228 printf(_("%s is not a block special device.\n"), device);
229 return 0;
230 }
231
232 /*
233 * Note: we use the older-style blkid API's here because we
234 * want as much functionality to be available when using the
235 * internal blkid library, when e2fsprogs is compiled for
236 * non-Linux systems that will probably not have the libraries
237 * from util-linux available. We only use the newer
238 * blkid-probe interfaces to access functionality not
239 * available in the original blkid library.
240 */
241 if ((flags & CHECK_FS_EXIST) && blkid_get_cache(&cache, NULL) >= 0) {
242 fs_type = blkid_get_tag_value(cache, "TYPE", device);
243 if (fs_type)
244 fs_label = blkid_get_tag_value(cache, "LABEL", device);
245 blkid_put_cache(cache);
246 }
247
248 if (fs_type) {
249 if (fs_label)
250 printf(_("%s contains a %s file system labelled '%s'\n"),
251 device, fs_type, fs_label);
252 else
253 printf(_("%s contains a %s file system\n"), device,
254 fs_type);
255 if (strncmp(fs_type, "ext", 3) == 0)
256 print_ext2_info(device);
257 free(fs_type);
258 free(fs_label);
259 return 0;
260 }
261
262 #ifdef HAVE_MAGIC_H
263 if ((flags & CHECK_FS_EXIST) &&
264 !getenv("E2FSPROGS_LIBMAGIC_SUPPRESS") &&
265 magic_library_available()) {
266 const char *msg;
267 magic_t mag;
268 int has_magic = 0;
269
270 mag = dl_magic_open(MAGIC_RAW | MAGIC_SYMLINK | MAGIC_DEVICES |
271 MAGIC_ERROR | MAGIC_NO_CHECK_ELF |
272 MAGIC_NO_CHECK_COMPRESS);
273 dl_magic_load(mag, NULL);
274
275 msg = dl_magic_file(mag, device);
276 if (msg && strcmp(msg, "data") && strcmp(msg, "empty")) {
277 printf(_("%s contains `%s' data\n"), device, msg);
278 has_magic = 1;
279 }
280
281 dl_magic_close(mag);
282 return !has_magic;
283 }
284 #endif
285 if (flags & CHECK_FS_EXIST) {
286 ret = check_partition_table(device);
287 if (ret >= 0)
288 return ret;
289 }
290 return 1;
291 }
292
293