summaryrefslogtreecommitdiff
path: root/src/dissect/dissect.c
blob: fd9db5ba8786b4016ff4edb2bb50fbdbcdd7b2d8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
/***
  This file is part of systemd.

  Copyright 2016 Lennart Poettering

  systemd is free software; you can redistribute it and/or modify it
  under the terms of the GNU Lesser General Public License as published by
  the Free Software Foundation; either version 2.1 of the License, or
  (at your option) any later version.

  systemd is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/

#include <fcntl.h>
#include <stdio.h>
#include <getopt.h>

#include "architecture.h"
#include "dissect-image.h"
#include "hexdecoct.h"
#include "log.h"
#include "loop-util.h"
#include "string-util.h"
#include "util.h"

static enum {
        ACTION_DISSECT,
        ACTION_MOUNT,
} arg_action = ACTION_DISSECT;
static const char *arg_image = NULL;
static const char *arg_path = NULL;
static DissectImageFlags arg_flags = DISSECT_IMAGE_REQUIRE_ROOT|DISSECT_IMAGE_DISCARD_ON_LOOP;
static void *arg_root_hash = NULL;
static size_t arg_root_hash_size = 0;

static void help(void) {
        printf("%s [OPTIONS...] IMAGE\n"
               "%s [OPTIONS...] --mount IMAGE PATH\n"
               "Dissect a file system OS image.\n\n"
               "  -h --help            Show this help\n"
               "     --version         Show package version\n"
               "  -m --mount           Mount the image to the specified directory\n"
               "  -r --read-only       Mount read-only\n"
               "     --discard=MODE    Choose 'discard' mode (disabled, loop, all, crypto)\n"
               "     --root-hash=HASH  Specify root hash for verity\n",
               program_invocation_short_name,
               program_invocation_short_name);
}

static int parse_argv(int argc, char *argv[]) {

        enum {
                ARG_VERSION = 0x100,
                ARG_DISCARD,
                ARG_ROOT_HASH,
        };

        static const struct option options[] = {
                { "help",      no_argument,       NULL, 'h'           },
                { "version",   no_argument,       NULL, ARG_VERSION   },
                { "mount",     no_argument,       NULL, 'm'           },
                { "read-only", no_argument,       NULL, 'r'           },
                { "discard",   required_argument, NULL, ARG_DISCARD   },
                { "root-hash", required_argument, NULL, ARG_ROOT_HASH },
                {}
        };

        int c, r;

        assert(argc >= 0);
        assert(argv);

        while ((c = getopt_long(argc, argv, "hmr", options, NULL)) >= 0) {

                switch (c) {

                case 'h':
                        help();
                        return 0;

                case ARG_VERSION:
                        return version();

                case 'm':
                        arg_action = ACTION_MOUNT;
                        break;

                case 'r':
                        arg_flags |= DISSECT_IMAGE_READ_ONLY;
                        break;

                case ARG_DISCARD: {
                        DissectImageFlags flags;

                        if (streq(optarg, "disabled"))
                                flags = 0;
                        else if (streq(optarg, "loop"))
                                flags = DISSECT_IMAGE_DISCARD_ON_LOOP;
                        else if (streq(optarg, "all"))
                                flags = DISSECT_IMAGE_DISCARD_ON_LOOP | DISSECT_IMAGE_DISCARD;
                        else if (streq(optarg, "crypt"))
                                flags = DISSECT_IMAGE_DISCARD_ANY;
                        else {
                                log_error("Unknown --discard= parameter: %s", optarg);
                                return -EINVAL;
                        }
                        arg_flags = (arg_flags & ~DISSECT_IMAGE_DISCARD_ANY) | flags;

                        break;
                }

                case ARG_ROOT_HASH: {
                        void *p;
                        size_t l;

                        r = unhexmem(optarg, strlen(optarg), &p, &l);
                        if (r < 0)
                                return log_error_errno(r, "Failed to parse root hash: %s", optarg);
                        if (l < sizeof(sd_id128_t)) {
                                log_error("Root hash must be at least 128bit long: %s", optarg);
                                free(p);
                                return -EINVAL;
                        }

                        free(arg_root_hash);
                        arg_root_hash = p;
                        arg_root_hash_size = l;
                        break;
                }

                case '?':
                        return -EINVAL;

                default:
                        assert_not_reached("Unhandled option");
                }

        }

        switch (arg_action) {

        case ACTION_DISSECT:
                if (optind + 1 != argc) {
                        log_error("Expected a file path as only argument.");
                        return -EINVAL;
                }

                arg_image = argv[optind];
                arg_flags |= DISSECT_IMAGE_READ_ONLY;
                break;

        case ACTION_MOUNT:
                if (optind + 2 != argc) {
                        log_error("Expected a file path and mount point path as only arguments.");
                        return -EINVAL;
                }

                arg_image = argv[optind];
                arg_path = argv[optind + 1];
                break;

        default:
                assert_not_reached("Unknown action.");
        }

        return 1;
}

int main(int argc, char *argv[]) {
        _cleanup_(loop_device_unrefp) LoopDevice *d = NULL;
        _cleanup_(decrypted_image_unrefp) DecryptedImage *di = NULL;
        _cleanup_(dissected_image_unrefp) DissectedImage *m = NULL;
        int r;

        log_parse_environment();
        log_open();

        r = parse_argv(argc, argv);
        if (r <= 0)
                goto finish;

        r = loop_device_make_by_path(arg_image, (arg_flags & DISSECT_IMAGE_READ_ONLY) ? O_RDONLY : O_RDWR, &d);
        if (r < 0) {
                log_error_errno(r, "Failed to set up loopback device: %m");
                goto finish;
        }

        r = dissect_image(d->fd, arg_root_hash, arg_root_hash_size, arg_flags, &m);
        if (r == -ENOPKG) {
                log_error_errno(r, "Couldn't identify a suitable partition table or file system in %s.", arg_image);
                goto finish;
        }
        if (r == -EADDRNOTAVAIL) {
                log_error_errno(r, "No root partition for specified root hash found in %s.", arg_image);
                goto finish;
        }
        if (r < 0) {
                log_error_errno(r, "Failed to dissect image: %m");
                goto finish;
        }

        switch (arg_action) {

        case ACTION_DISSECT: {
                unsigned i;

                for (i = 0; i < _PARTITION_DESIGNATOR_MAX; i++) {
                        DissectedPartition *p = m->partitions + i;
                        int k;

                        if (!p->found)
                                continue;

                        printf("Found %s '%s' partition",
                               p->rw ? "writable" : "read-only",
                               partition_designator_to_string(i));

                        if (!sd_id128_is_null(p->uuid))
                                printf(" (UUID " SD_ID128_FORMAT_STR ")", SD_ID128_FORMAT_VAL(p->uuid));

                        if (p->fstype)
                                printf(" of type %s", p->fstype);

                        if (p->architecture != _ARCHITECTURE_INVALID)
                                printf(" for %s", architecture_to_string(p->architecture));

                        k = PARTITION_VERITY_OF(i);
                        if (k >= 0)
                                printf(" %s verity", m->partitions[k].found ? "with" : "without");

                        if (p->partno >= 0)
                                printf(" on partition #%i", p->partno);

                        if (p->node)
                                printf(" (%s)", p->node);

                        putchar('\n');
                }

                break;
        }

        case ACTION_MOUNT:
                r = dissected_image_decrypt_interactively(m, NULL, arg_root_hash, arg_root_hash_size, arg_flags, &di);
                if (r < 0)
                        goto finish;

                r = dissected_image_mount(m, arg_path, arg_flags);
                if (r < 0) {
                        log_error_errno(r, "Failed to mount image: %m");
                        goto finish;
                }

                if (di) {
                        r = decrypted_image_relinquish(di);
                        if (r < 0) {
                                log_error_errno(r, "Failed to relinquish DM devices: %m");
                                goto finish;
                        }
                }

                loop_device_relinquish(d);
                break;

        default:
                assert_not_reached("Unknown action.");
        }

finish:
        free(arg_root_hash);
        return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
}