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
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
|
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2015 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 <sys/prctl.h>
#include "util.h"
#include "strv.h"
#include "copy.h"
#include "btrfs-util.h"
#include "capability.h"
#include "import-job.h"
#include "import-common.h"
#define FILENAME_ESCAPE "/.#\"\'"
int import_find_old_etags(const char *url, const char *image_root, int dt, const char *prefix, const char *suffix, char ***etags) {
_cleanup_free_ char *escaped_url = NULL;
_cleanup_closedir_ DIR *d = NULL;
_cleanup_strv_free_ char **l = NULL;
struct dirent *de;
int r;
assert(url);
assert(etags);
if (!image_root)
image_root = "/var/lib/machines";
escaped_url = xescape(url, FILENAME_ESCAPE);
if (!escaped_url)
return -ENOMEM;
d = opendir(image_root);
if (!d) {
if (errno == ENOENT) {
*etags = NULL;
return 0;
}
return -errno;
}
FOREACH_DIRENT_ALL(de, d, return -errno) {
const char *a, *b;
char *u;
if (de->d_type != DT_UNKNOWN &&
de->d_type != dt)
continue;
if (prefix) {
a = startswith(de->d_name, prefix);
if (!a)
continue;
} else
a = de->d_name;
a = startswith(a, escaped_url);
if (!a)
continue;
a = startswith(a, ".");
if (!a)
continue;
if (suffix) {
b = endswith(de->d_name, suffix);
if (!b)
continue;
} else
b = strchr(de->d_name, 0);
if (a >= b)
continue;
u = cunescape_length(a, b - a);
if (!u)
return -ENOMEM;
if (!http_etag_is_valid(u)) {
free(u);
continue;
}
r = strv_consume(&l, u);
if (r < 0)
return r;
}
*etags = l;
l = NULL;
return 0;
}
int import_make_local_copy(const char *final, const char *image_root, const char *local, bool force_local) {
const char *p;
int r;
assert(final);
assert(local);
if (!image_root)
image_root = "/var/lib/machines";
p = strappenda(image_root, "/", local);
if (force_local) {
(void) btrfs_subvol_remove(p);
(void) rm_rf_dangerous(p, false, true, false);
}
r = btrfs_subvol_snapshot(final, p, false, false);
if (r == -ENOTTY) {
r = copy_tree(final, p, false);
if (r < 0)
return log_error_errno(r, "Failed to copy image: %m");
} else if (r < 0)
return log_error_errno(r, "Failed to create local image: %m");
log_info("Created new local image '%s'.", local);
return 0;
}
int import_make_read_only_fd(int fd) {
int r;
assert(fd >= 0);
/* First, let's make this a read-only subvolume if it refers
* to a subvolume */
r = btrfs_subvol_set_read_only_fd(fd, true);
if (r == -ENOTTY || r == -ENOTDIR || r == -EINVAL) {
struct stat st;
/* This doesn't refer to a subvolume, or the file
* system isn't even btrfs. In that, case fall back to
* chmod()ing */
r = fstat(fd, &st);
if (r < 0)
return log_error_errno(errno, "Failed to stat temporary image: %m");
/* Drop "w" flag */
if (fchmod(fd, st.st_mode & 07555) < 0)
return log_error_errno(errno, "Failed to chmod() final image: %m");
return 0;
} else if (r < 0)
return log_error_errno(r, "Failed to make subvolume read-only: %m");
return 0;
}
int import_make_read_only(const char *path) {
_cleanup_close_ int fd = 1;
fd = open(path, O_RDONLY|O_NOCTTY|O_CLOEXEC);
if (fd < 0)
return log_error_errno(errno, "Failed to open %s: %m", path);
return import_make_read_only_fd(fd);
}
int import_make_path(const char *url, const char *etag, const char *image_root, const char *prefix, const char *suffix, char **ret) {
_cleanup_free_ char *escaped_url = NULL;
char *path;
assert(url);
assert(ret);
if (!image_root)
image_root = "/var/lib/machines";
escaped_url = xescape(url, FILENAME_ESCAPE);
if (!escaped_url)
return -ENOMEM;
if (etag) {
_cleanup_free_ char *escaped_etag = NULL;
escaped_etag = xescape(etag, FILENAME_ESCAPE);
if (!escaped_etag)
return -ENOMEM;
path = strjoin(image_root, "/", strempty(prefix), escaped_url, ".", escaped_etag, strempty(suffix), NULL);
} else
path = strjoin(image_root, "/", strempty(prefix), escaped_url, strempty(suffix), NULL);
if (!path)
return -ENOMEM;
*ret = path;
return 0;
}
int import_make_verification_jobs(
ImportJob **ret_checksum_job,
ImportJob **ret_signature_job,
ImportVerify verify,
const char *url,
CurlGlue *glue,
ImportJobFinished on_finished,
void *userdata) {
_cleanup_(import_job_unrefp) ImportJob *checksum_job = NULL, *signature_job = NULL;
int r;
assert(ret_checksum_job);
assert(ret_signature_job);
assert(verify >= 0);
assert(verify < _IMPORT_VERIFY_MAX);
assert(url);
assert(glue);
if (verify != IMPORT_VERIFY_NO) {
_cleanup_free_ char *checksum_url = NULL;
/* Queue job for the SHA256SUMS file for the image */
r = import_url_change_last_component(url, "SHA256SUMS", &checksum_url);
if (r < 0)
return r;
r = import_job_new(&checksum_job, checksum_url, glue, userdata);
if (r < 0)
return r;
checksum_job->on_finished = on_finished;
checksum_job->uncompressed_max = checksum_job->compressed_max = 1ULL * 1024ULL * 1024ULL;
}
if (verify == IMPORT_VERIFY_SIGNATURE) {
_cleanup_free_ char *signature_url = NULL;
/* Queue job for the SHA256SUMS.gpg file for the image. */
r = import_url_change_last_component(url, "SHA256SUMS.gpg", &signature_url);
if (r < 0)
return r;
r = import_job_new(&signature_job, signature_url, glue, userdata);
if (r < 0)
return r;
signature_job->on_finished = on_finished;
signature_job->uncompressed_max = signature_job->compressed_max = 1ULL * 1024ULL * 1024ULL;
}
*ret_checksum_job = checksum_job;
*ret_signature_job = signature_job;
checksum_job = signature_job = NULL;
return 0;
}
int import_verify(
ImportJob *main_job,
ImportJob *checksum_job,
ImportJob *signature_job) {
_cleanup_close_pair_ int gpg_pipe[2] = { -1, -1 };
_cleanup_free_ char *fn = NULL;
_cleanup_close_ int sig_file = -1;
const char *p, *line;
char sig_file_path[] = "/tmp/sigXXXXXX";
_cleanup_sigkill_wait_ pid_t pid = 0;
int r;
assert(main_job);
assert(main_job->state == IMPORT_JOB_DONE);
if (!checksum_job)
return 0;
assert(main_job->calc_checksum);
assert(main_job->checksum);
assert(checksum_job->state == IMPORT_JOB_DONE);
if (!checksum_job->payload || checksum_job->payload_size <= 0) {
log_error("Checksum is empty, cannot verify.");
return -EBADMSG;
}
r = import_url_last_component(main_job->url, &fn);
if (r < 0)
return log_oom();
if (!filename_is_valid(fn)) {
log_error("Cannot verify checksum, could not determine valid server-side file name.");
return -EBADMSG;
}
line = strappenda(main_job->checksum, " *", fn, "\n");
p = memmem(checksum_job->payload,
checksum_job->payload_size,
line,
strlen(line));
if (!p || (p != (char*) checksum_job->payload && p[-1] != '\n')) {
log_error("Checksum did not check out, payload has been tempered with.");
return -EBADMSG;
}
log_info("SHA256 checksum of %s is valid.", main_job->url);
if (!signature_job)
return 0;
assert(signature_job->state == IMPORT_JOB_DONE);
if (!signature_job->payload || signature_job->payload_size <= 0) {
log_error("Signature is empty, cannot verify.");
return -EBADMSG;
}
r = pipe2(gpg_pipe, O_CLOEXEC);
if (r < 0)
return log_error_errno(errno, "Failed to create pipe for gpg: %m");
sig_file = mkostemp(sig_file_path, O_RDWR);
if (sig_file < 0)
return log_error_errno(errno, "Failed to create temporary file: %m");
r = loop_write(sig_file, signature_job->payload, signature_job->payload_size, false);
if (r < 0) {
log_error_errno(r, "Failed to write to temporary file: %m");
goto finish;
}
pid = fork();
if (pid < 0)
return log_error_errno(errno, "Failed to fork off gpg: %m");
if (pid == 0) {
const char *cmd[] = {
"gpg",
"--no-options",
"--no-default-keyring",
"--no-auto-key-locate",
"--no-auto-check-trustdb",
"--batch",
"--trust-model=always",
NULL, /* keyring to use */
NULL, /* --verify */
NULL, /* signature file */
NULL, /* dash */
NULL /* trailing NULL */
};
unsigned k = ELEMENTSOF(cmd) - 5;
int null_fd;
/* Child */
reset_all_signal_handlers();
reset_signal_mask();
assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0);
gpg_pipe[1] = safe_close(gpg_pipe[1]);
if (dup2(gpg_pipe[0], STDIN_FILENO) != STDIN_FILENO) {
log_error_errno(errno, "Failed to dup2() fd: %m");
_exit(EXIT_FAILURE);
}
if (gpg_pipe[0] != STDIN_FILENO)
gpg_pipe[0] = safe_close(gpg_pipe[0]);
null_fd = open("/dev/null", O_WRONLY|O_NOCTTY);
if (null_fd < 0) {
log_error_errno(errno, "Failed to open /dev/null: %m");
_exit(EXIT_FAILURE);
}
if (dup2(null_fd, STDOUT_FILENO) != STDOUT_FILENO) {
log_error_errno(errno, "Failed to dup2() fd: %m");
_exit(EXIT_FAILURE);
}
if (null_fd != STDOUT_FILENO)
null_fd = safe_close(null_fd);
/* We add the user keyring only to the command line
* arguments, if it's around since gpg fails
* otherwise. */
if (access(USER_KEYRING_PATH, F_OK) >= 0)
cmd[k++] = "--keyring=" USER_KEYRING_PATH;
else
cmd[k++] = "--keyring=" VENDOR_KEYRING_PATH;
cmd[k++] = "--verify";
cmd[k++] = sig_file_path;
cmd[k++] = "-";
cmd[k++] = NULL;
fd_cloexec(STDIN_FILENO, false);
fd_cloexec(STDOUT_FILENO, false);
fd_cloexec(STDERR_FILENO, false);
execvp("gpg", (char * const *) cmd);
log_error_errno(errno, "Failed to execute gpg: %m");
_exit(EXIT_FAILURE);
}
gpg_pipe[0] = safe_close(gpg_pipe[0]);
r = loop_write(gpg_pipe[1], checksum_job->payload, checksum_job->payload_size, false);
if (r < 0) {
log_error_errno(r, "Failed to write to pipe: %m");
goto finish;
}
gpg_pipe[1] = safe_close(gpg_pipe[1]);
r = wait_for_terminate_and_warn("gpg", pid, true);
pid = 0;
if (r < 0)
goto finish;
if (r > 0) {
log_error("Signature verification failed.");
r = -EBADMSG;
} else {
log_info("Signature verification succeeded.");
r = 0;
}
finish:
if (sig_file >= 0)
unlink(sig_file_path);
return r;
}
int import_fork_tar(const char *path, pid_t *ret) {
_cleanup_close_pair_ int pipefd[2] = { -1, -1 };
pid_t pid;
int r;
assert(path);
assert(ret);
if (pipe2(pipefd, O_CLOEXEC) < 0)
return log_error_errno(errno, "Failed to create pipe for tar: %m");
pid = fork();
if (pid < 0)
return log_error_errno(errno, "Failed to fork off tar: %m");
if (pid == 0) {
int null_fd;
uint64_t retain =
(1ULL << CAP_CHOWN) |
(1ULL << CAP_FOWNER) |
(1ULL << CAP_FSETID) |
(1ULL << CAP_MKNOD) |
(1ULL << CAP_SETFCAP);
/* Child */
reset_all_signal_handlers();
reset_signal_mask();
assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0);
pipefd[1] = safe_close(pipefd[1]);
if (dup2(pipefd[0], STDIN_FILENO) != STDIN_FILENO) {
log_error_errno(errno, "Failed to dup2() fd: %m");
_exit(EXIT_FAILURE);
}
if (pipefd[0] != STDIN_FILENO)
pipefd[0] = safe_close(pipefd[0]);
null_fd = open("/dev/null", O_WRONLY|O_NOCTTY);
if (null_fd < 0) {
log_error_errno(errno, "Failed to open /dev/null: %m");
_exit(EXIT_FAILURE);
}
if (dup2(null_fd, STDOUT_FILENO) != STDOUT_FILENO) {
log_error_errno(errno, "Failed to dup2() fd: %m");
_exit(EXIT_FAILURE);
}
if (null_fd != STDOUT_FILENO)
null_fd = safe_close(null_fd);
fd_cloexec(STDIN_FILENO, false);
fd_cloexec(STDOUT_FILENO, false);
fd_cloexec(STDERR_FILENO, false);
if (unshare(CLONE_NEWNET) < 0)
log_error_errno(errno, "Failed to lock tar into network namespace, ignoring: %m");
r = capability_bounding_set_drop(~retain, true);
if (r < 0)
log_error_errno(r, "Failed to drop capabilities, ignoring: %m");
execlp("tar", "tar", "--numeric-owner", "-C", path, "-px", NULL);
log_error_errno(errno, "Failed to execute tar: %m");
_exit(EXIT_FAILURE);
}
pipefd[0] = safe_close(pipefd[0]);
r = pipefd[1];
pipefd[1] = -1;
*ret = pid;
return r;
}
|