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