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- Committer: Teddy Hogeborn
- Date: 2018-08-15 09:13:36 UTC
- Revision ID: teddy@recompile.se-20180815091336-fxwk6vbop0m8xyur
Linking flags correction
* Makefile (CFLAGS): Remove "$(GNUTLS_CFLAGS) $(AVAHI_CFLAGS)
$(GPGME_CFLAGS)", since these libraries are not
used by all programs.
(plugins.d/mandos-client): Add "$(GNUTLS_CFLAGS) $(AVAHI_CFLAGS)
$(GPGME_CFLAGS)".
* Makefile (CFLAGS): Remove "$(GNUTLS_CFLAGS) $(AVAHI_CFLAGS)
$(GPGME_CFLAGS)", since these libraries are not
used by all programs.
(plugins.d/mandos-client): Add "$(GNUTLS_CFLAGS) $(AVAHI_CFLAGS)
$(GPGME_CFLAGS)".
- files added:
- .bzr-builddeb
- debian
- debian/po
- debian/source
- debian/upstream
- network-hooks.d
- plugin-helpers
- plugins.d
- files removed:
- bad-ca.pem
- files renamed:
- mandos-clients.conf => clients.conf
- server.py => mandos
- files modified:
- Makefile
added
removed
plugins.d/mandos-client.c
1
/* -*- coding: utf-8 -*- */
2
/*
3
* Mandos-client - get and decrypt data from a Mandos server
4
*
5
* This program is partly derived from an example program for an Avahi
6
* service browser, downloaded from
7
* <http://avahi.org/browser/examples/core-browse-services.c>. This
8
* includes the following functions: "resolve_callback",
9
* "browse_callback", and parts of "main".
10
*
11
* Everything else is
12
* Copyright © 2008-2018 Teddy Hogeborn
13
* Copyright © 2008-2018 Björn Påhlsson
14
*
15
* This file is part of Mandos.
16
*
17
* Mandos is free software: you can redistribute it and/or modify it
18
* under the terms of the GNU General Public License as published by
19
* the Free Software Foundation, either version 3 of the License, or
20
* (at your option) any later version.
21
*
22
* Mandos is distributed in the hope that it will be useful, but
23
* WITHOUT ANY WARRANTY; without even the implied warranty of
24
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
25
* General Public License for more details.
26
*
27
* You should have received a copy of the GNU General Public License
28
* along with Mandos. If not, see <http://www.gnu.org/licenses/>.
29
*
30
* Contact the authors at <mandos@recompile.se>.
31
*/
32
33
/* Needed by GPGME, specifically gpgme_data_seek() */
34
#ifndef _LARGEFILE_SOURCE
35
#define _LARGEFILE_SOURCE
36
#endif /* not _LARGEFILE_SOURCE */
37
#ifndef _FILE_OFFSET_BITS
38
#define _FILE_OFFSET_BITS 64
39
#endif /* not _FILE_OFFSET_BITS */
40
41
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
42
43
#include <stdio.h> /* fprintf(), stderr, fwrite(),
44
stdout, ferror() */
45
#include <stdint.h> /* uint16_t, uint32_t, intptr_t */
46
#include <stddef.h> /* NULL, size_t, ssize_t */
47
#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),
48
strtof(), abort() */
49
#include <stdbool.h> /* bool, false, true */
50
#include <string.h> /* strcmp(), strlen(), strerror(),
51
asprintf(), strncpy(), strsignal()
52
*/
53
#include <sys/ioctl.h> /* ioctl */
54
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
55
sockaddr_in6, PF_INET6,
56
SOCK_STREAM, uid_t, gid_t, open(),
57
opendir(), DIR */
58
#include <sys/stat.h> /* open(), S_ISREG */
59
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
60
inet_pton(), connect(),
61
getnameinfo() */
62
#include <fcntl.h> /* open(), unlinkat(), AT_REMOVEDIR */
63
#include <dirent.h> /* opendir(), struct dirent, readdir()
64
*/
65
#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,
66
strtoimax() */
67
#include <errno.h> /* perror(), errno, EINTR, EINVAL,
68
EAI_SYSTEM, ENETUNREACH,
69
EHOSTUNREACH, ECONNREFUSED, EPROTO,
70
EIO, ENOENT, ENXIO, ENOMEM, EISDIR,
71
ENOTEMPTY,
72
program_invocation_short_name */
73
#include <time.h> /* nanosleep(), time(), sleep() */
74
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
75
SIOCSIFFLAGS, if_indextoname(),
76
if_nametoindex(), IF_NAMESIZE */
77
#include <netinet/in.h> /* IN6_IS_ADDR_LINKLOCAL,
78
INET_ADDRSTRLEN, INET6_ADDRSTRLEN
79
*/
80
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
81
getuid(), getgid(), seteuid(),
82
setgid(), pause(), _exit(),
83
unlinkat() */
84
#include <arpa/inet.h> /* inet_pton(), htons() */
85
#include <iso646.h> /* not, or, and */
86
#include <argp.h> /* struct argp_option, error_t, struct
87
argp_state, struct argp,
88
argp_parse(), ARGP_KEY_ARG,
89
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
90
#include <signal.h> /* sigemptyset(), sigaddset(),
91
sigaction(), SIGTERM, sig_atomic_t,
92
raise() */
93
#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,
94
EX_NOHOST, EX_IOERR, EX_PROTOCOL */
95
#include <sys/wait.h> /* waitpid(), WIFEXITED(),
96
WEXITSTATUS(), WTERMSIG() */
97
#include <grp.h> /* setgroups() */
98
#include <argz.h> /* argz_add_sep(), argz_next(),
99
argz_delete(), argz_append(),
100
argz_stringify(), argz_add(),
101
argz_count() */
102
#include <netdb.h> /* getnameinfo(), NI_NUMERICHOST,
103
EAI_SYSTEM, gai_strerror() */
104
105
#ifdef __linux__
106
#include <sys/klog.h> /* klogctl() */
107
#endif /* __linux__ */
108
109
/* Avahi */
110
/* All Avahi types, constants and functions
111
Avahi*, avahi_*,
112
AVAHI_* */
113
#include <avahi-core/core.h>
114
#include <avahi-core/lookup.h>
115
#include <avahi-core/log.h>
116
#include <avahi-common/simple-watch.h>
117
#include <avahi-common/malloc.h>
118
#include <avahi-common/error.h>
119
120
/* GnuTLS */
121
#include <gnutls/gnutls.h> /* All GnuTLS types, constants and
122
functions:
123
gnutls_*
124
init_gnutls_session(),
125
GNUTLS_* */
126
#include <gnutls/openpgp.h>
127
/* gnutls_certificate_set_openpgp_key_file(),
128
GNUTLS_OPENPGP_FMT_BASE64 */
129
130
/* GPGME */
131
#include <gpgme.h> /* All GPGME types, constants and
132
functions:
133
gpgme_*
134
GPGME_PROTOCOL_OpenPGP,
135
GPG_ERR_NO_* */
136
137
#define BUFFER_SIZE 256
138
139
#define PATHDIR "/conf/conf.d/mandos"
140
#define SECKEY "seckey.txt"
141
#define PUBKEY "pubkey.txt"
142
#define HOOKDIR "/lib/mandos/network-hooks.d"
143
144
bool debug = false;
145
static const char mandos_protocol_version[] = "1";
146
const char *argp_program_version = "mandos-client " VERSION;
147
const char *argp_program_bug_address = "<mandos@recompile.se>";
148
static const char sys_class_net[] = "/sys/class/net";
149
char *connect_to = NULL;
150
const char *hookdir = HOOKDIR;
151
int hookdir_fd = -1;
152
uid_t uid = 65534;
153
gid_t gid = 65534;
154
155
/* Doubly linked list that need to be circularly linked when used */
156
typedef struct server{
157
const char *ip;
158
in_port_t port;
159
AvahiIfIndex if_index;
160
int af;
161
struct timespec last_seen;
162
struct server *next;
163
struct server *prev;
164
} server;
165
166
/* Used for passing in values through the Avahi callback functions */
167
typedef struct {
168
AvahiServer *server;
169
gnutls_certificate_credentials_t cred;
170
unsigned int dh_bits;
171
gnutls_dh_params_t dh_params;
172
const char *priority;
173
gpgme_ctx_t ctx;
174
server *current_server;
175
char *interfaces;
176
size_t interfaces_size;
177
} mandos_context;
178
179
/* global so signal handler can reach it*/
180
AvahiSimplePoll *simple_poll;
181
182
sig_atomic_t quit_now = 0;
183
int signal_received = 0;
184
185
/* Function to use when printing errors */
186
void perror_plus(const char *print_text){
187
int e = errno;
188
fprintf(stderr, "Mandos plugin %s: ",
189
program_invocation_short_name);
190
errno = e;
191
perror(print_text);
192
}
193
194
__attribute__((format (gnu_printf, 2, 3), nonnull))
195
int fprintf_plus(FILE *stream, const char *format, ...){
196
va_list ap;
197
va_start (ap, format);
198
199
TEMP_FAILURE_RETRY(fprintf(stream, "Mandos plugin %s: ",
200
program_invocation_short_name));
201
return (int)TEMP_FAILURE_RETRY(vfprintf(stream, format, ap));
202
}
203
204
/*
205
* Make additional room in "buffer" for at least BUFFER_SIZE more
206
* bytes. "buffer_capacity" is how much is currently allocated,
207
* "buffer_length" is how much is already used.
208
*/
209
__attribute__((nonnull, warn_unused_result))
210
size_t incbuffer(char **buffer, size_t buffer_length,
211
size_t buffer_capacity){
212
if(buffer_length + BUFFER_SIZE > buffer_capacity){
213
char *new_buf = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
214
if(new_buf == NULL){
215
int old_errno = errno;
216
free(*buffer);
217
errno = old_errno;
218
*buffer = NULL;
219
return 0;
220
}
221
*buffer = new_buf;
222
buffer_capacity += BUFFER_SIZE;
223
}
224
return buffer_capacity;
225
}
226
227
/* Add server to set of servers to retry periodically */
228
__attribute__((nonnull, warn_unused_result))
229
bool add_server(const char *ip, in_port_t port, AvahiIfIndex if_index,
230
int af, server **current_server){
231
int ret;
232
server *new_server = malloc(sizeof(server));
233
if(new_server == NULL){
234
perror_plus("malloc");
235
return false;
236
}
237
*new_server = (server){ .ip = strdup(ip),
238
.port = port,
239
.if_index = if_index,
240
.af = af };
241
if(new_server->ip == NULL){
242
perror_plus("strdup");
243
free(new_server);
244
return false;
245
}
246
ret = clock_gettime(CLOCK_MONOTONIC, &(new_server->last_seen));
247
if(ret == -1){
248
perror_plus("clock_gettime");
249
#ifdef __GNUC__
250
#pragma GCC diagnostic push
251
#pragma GCC diagnostic ignored "-Wcast-qual"
252
#endif
253
free((char *)(new_server->ip));
254
#ifdef __GNUC__
255
#pragma GCC diagnostic pop
256
#endif
257
free(new_server);
258
return false;
259
}
260
/* Special case of first server */
261
if(*current_server == NULL){
262
new_server->next = new_server;
263
new_server->prev = new_server;
264
*current_server = new_server;
265
} else {
266
/* Place the new server last in the list */
267
new_server->next = *current_server;
268
new_server->prev = (*current_server)->prev;
269
new_server->prev->next = new_server;
270
(*current_server)->prev = new_server;
271
}
272
return true;
273
}
274
275
/*
276
* Initialize GPGME.
277
*/
278
__attribute__((nonnull, warn_unused_result))
279
static bool init_gpgme(const char * const seckey,
280
const char * const pubkey,
281
const char * const tempdir,
282
mandos_context *mc){
283
gpgme_error_t rc;
284
gpgme_engine_info_t engine_info;
285
286
/*
287
* Helper function to insert pub and seckey to the engine keyring.
288
*/
289
bool import_key(const char * const filename){
290
int ret;
291
int fd;
292
gpgme_data_t pgp_data;
293
294
fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
295
if(fd == -1){
296
perror_plus("open");
297
return false;
298
}
299
300
rc = gpgme_data_new_from_fd(&pgp_data, fd);
301
if(rc != GPG_ERR_NO_ERROR){
302
fprintf_plus(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
303
gpgme_strsource(rc), gpgme_strerror(rc));
304
return false;
305
}
306
307
rc = gpgme_op_import(mc->ctx, pgp_data);
308
if(rc != GPG_ERR_NO_ERROR){
309
fprintf_plus(stderr, "bad gpgme_op_import: %s: %s\n",
310
gpgme_strsource(rc), gpgme_strerror(rc));
311
return false;
312
}
313
{
314
gpgme_import_result_t import_result
315
= gpgme_op_import_result(mc->ctx);
316
if((import_result->imported < 1
317
or import_result->not_imported > 0)
318
and import_result->unchanged == 0){
319
fprintf_plus(stderr, "bad gpgme_op_import_results:\n");
320
fprintf_plus(stderr,
321
"The total number of considered keys: %d\n",
322
import_result->considered);
323
fprintf_plus(stderr,
324
"The number of keys without user ID: %d\n",
325
import_result->no_user_id);
326
fprintf_plus(stderr,
327
"The total number of imported keys: %d\n",
328
import_result->imported);
329
fprintf_plus(stderr, "The number of imported RSA keys: %d\n",
330
import_result->imported_rsa);
331
fprintf_plus(stderr, "The number of unchanged keys: %d\n",
332
import_result->unchanged);
333
fprintf_plus(stderr, "The number of new user IDs: %d\n",
334
import_result->new_user_ids);
335
fprintf_plus(stderr, "The number of new sub keys: %d\n",
336
import_result->new_sub_keys);
337
fprintf_plus(stderr, "The number of new signatures: %d\n",
338
import_result->new_signatures);
339
fprintf_plus(stderr, "The number of new revocations: %d\n",
340
import_result->new_revocations);
341
fprintf_plus(stderr,
342
"The total number of secret keys read: %d\n",
343
import_result->secret_read);
344
fprintf_plus(stderr,
345
"The number of imported secret keys: %d\n",
346
import_result->secret_imported);
347
fprintf_plus(stderr,
348
"The number of unchanged secret keys: %d\n",
349
import_result->secret_unchanged);
350
fprintf_plus(stderr, "The number of keys not imported: %d\n",
351
import_result->not_imported);
352
for(gpgme_import_status_t import_status
353
= import_result->imports;
354
import_status != NULL;
355
import_status = import_status->next){
356
fprintf_plus(stderr, "Import status for key: %s\n",
357
import_status->fpr);
358
if(import_status->result != GPG_ERR_NO_ERROR){
359
fprintf_plus(stderr, "Import result: %s: %s\n",
360
gpgme_strsource(import_status->result),
361
gpgme_strerror(import_status->result));
362
}
363
fprintf_plus(stderr, "Key status:\n");
364
fprintf_plus(stderr,
365
import_status->status & GPGME_IMPORT_NEW
366
? "The key was new.\n"
367
: "The key was not new.\n");
368
fprintf_plus(stderr,
369
import_status->status & GPGME_IMPORT_UID
370
? "The key contained new user IDs.\n"
371
: "The key did not contain new user IDs.\n");
372
fprintf_plus(stderr,
373
import_status->status & GPGME_IMPORT_SIG
374
? "The key contained new signatures.\n"
375
: "The key did not contain new signatures.\n");
376
fprintf_plus(stderr,
377
import_status->status & GPGME_IMPORT_SUBKEY
378
? "The key contained new sub keys.\n"
379
: "The key did not contain new sub keys.\n");
380
fprintf_plus(stderr,
381
import_status->status & GPGME_IMPORT_SECRET
382
? "The key contained a secret key.\n"
383
: "The key did not contain a secret key.\n");
384
}
385
return false;
386
}
387
}
388
389
ret = close(fd);
390
if(ret == -1){
391
perror_plus("close");
392
}
393
gpgme_data_release(pgp_data);
394
return true;
395
}
396
397
if(debug){
398
fprintf_plus(stderr, "Initializing GPGME\n");
399
}
400
401
/* Init GPGME */
402
gpgme_check_version(NULL);
403
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
404
if(rc != GPG_ERR_NO_ERROR){
405
fprintf_plus(stderr, "bad gpgme_engine_check_version: %s: %s\n",
406
gpgme_strsource(rc), gpgme_strerror(rc));
407
return false;
408
}
409
410
/* Set GPGME home directory for the OpenPGP engine only */
411
rc = gpgme_get_engine_info(&engine_info);
412
if(rc != GPG_ERR_NO_ERROR){
413
fprintf_plus(stderr, "bad gpgme_get_engine_info: %s: %s\n",
414
gpgme_strsource(rc), gpgme_strerror(rc));
415
return false;
416
}
417
while(engine_info != NULL){
418
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
419
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
420
engine_info->file_name, tempdir);
421
break;
422
}
423
engine_info = engine_info->next;
424
}
425
if(engine_info == NULL){
426
fprintf_plus(stderr, "Could not set GPGME home dir to %s\n",
427
tempdir);
428
return false;
429
}
430
431
/* Create new GPGME "context" */
432
rc = gpgme_new(&(mc->ctx));
433
if(rc != GPG_ERR_NO_ERROR){
434
fprintf_plus(stderr, "bad gpgme_new: %s: %s\n",
435
gpgme_strsource(rc), gpgme_strerror(rc));
436
return false;
437
}
438
439
if(not import_key(pubkey) or not import_key(seckey)){
440
return false;
441
}
442
443
return true;
444
}
445
446
/*
447
* Decrypt OpenPGP data.
448
* Returns -1 on error
449
*/
450
__attribute__((nonnull, warn_unused_result))
451
static ssize_t pgp_packet_decrypt(const char *cryptotext,
452
size_t crypto_size,
453
char **plaintext,
454
mandos_context *mc){
455
gpgme_data_t dh_crypto, dh_plain;
456
gpgme_error_t rc;
457
ssize_t ret;
458
size_t plaintext_capacity = 0;
459
ssize_t plaintext_length = 0;
460
461
if(debug){
462
fprintf_plus(stderr, "Trying to decrypt OpenPGP data\n");
463
}
464
465
/* Create new GPGME data buffer from memory cryptotext */
466
rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,
467
0);
468
if(rc != GPG_ERR_NO_ERROR){
469
fprintf_plus(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
470
gpgme_strsource(rc), gpgme_strerror(rc));
471
return -1;
472
}
473
474
/* Create new empty GPGME data buffer for the plaintext */
475
rc = gpgme_data_new(&dh_plain);
476
if(rc != GPG_ERR_NO_ERROR){
477
fprintf_plus(stderr, "bad gpgme_data_new: %s: %s\n",
478
gpgme_strsource(rc), gpgme_strerror(rc));
479
gpgme_data_release(dh_crypto);
480
return -1;
481
}
482
483
/* Decrypt data from the cryptotext data buffer to the plaintext
484
data buffer */
485
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
486
if(rc != GPG_ERR_NO_ERROR){
487
fprintf_plus(stderr, "bad gpgme_op_decrypt: %s: %s\n",
488
gpgme_strsource(rc), gpgme_strerror(rc));
489
plaintext_length = -1;
490
if(debug){
491
gpgme_decrypt_result_t result;
492
result = gpgme_op_decrypt_result(mc->ctx);
493
if(result == NULL){
494
fprintf_plus(stderr, "gpgme_op_decrypt_result failed\n");
495
} else {
496
if(result->unsupported_algorithm != NULL) {
497
fprintf_plus(stderr, "Unsupported algorithm: %s\n",
498
result->unsupported_algorithm);
499
}
500
fprintf_plus(stderr, "Wrong key usage: %s\n",
501
result->wrong_key_usage ? "Yes" : "No");
502
if(result->file_name != NULL){
503
fprintf_plus(stderr, "File name: %s\n", result->file_name);
504
}
505
506
for(gpgme_recipient_t r = result->recipients; r != NULL;
507
r = r->next){
508
fprintf_plus(stderr, "Public key algorithm: %s\n",
509
gpgme_pubkey_algo_name(r->pubkey_algo));
510
fprintf_plus(stderr, "Key ID: %s\n", r->keyid);
511
fprintf_plus(stderr, "Secret key available: %s\n",
512
r->status == GPG_ERR_NO_SECKEY ? "No" : "Yes");
513
}
514
}
515
}
516
goto decrypt_end;
517
}
518
519
if(debug){
520
fprintf_plus(stderr, "Decryption of OpenPGP data succeeded\n");
521
}
522
523
/* Seek back to the beginning of the GPGME plaintext data buffer */
524
if(gpgme_data_seek(dh_plain, (off_t)0, SEEK_SET) == -1){
525
perror_plus("gpgme_data_seek");
526
plaintext_length = -1;
527
goto decrypt_end;
528
}
529
530
*plaintext = NULL;
531
while(true){
532
plaintext_capacity = incbuffer(plaintext,
533
(size_t)plaintext_length,
534
plaintext_capacity);
535
if(plaintext_capacity == 0){
536
perror_plus("incbuffer");
537
plaintext_length = -1;
538
goto decrypt_end;
539
}
540
541
ret = gpgme_data_read(dh_plain, *plaintext + plaintext_length,
542
BUFFER_SIZE);
543
/* Print the data, if any */
544
if(ret == 0){
545
/* EOF */
546
break;
547
}
548
if(ret < 0){
549
perror_plus("gpgme_data_read");
550
plaintext_length = -1;
551
goto decrypt_end;
552
}
553
plaintext_length += ret;
554
}
555
556
if(debug){
557
fprintf_plus(stderr, "Decrypted password is: ");
558
for(ssize_t i = 0; i < plaintext_length; i++){
559
fprintf(stderr, "%02hhX ", (*plaintext)[i]);
560
}
561
fprintf(stderr, "\n");
562
}
563
564
decrypt_end:
565
566
/* Delete the GPGME cryptotext data buffer */
567
gpgme_data_release(dh_crypto);
568
569
/* Delete the GPGME plaintext data buffer */
570
gpgme_data_release(dh_plain);
571
return plaintext_length;
572
}
573
574
__attribute__((warn_unused_result, const))
575
static const char *safe_string(const char *str){
576
if(str == NULL)
577
return "(unknown)";
578
return str;
579
}
580
581
__attribute__((warn_unused_result))
582
static const char *safer_gnutls_strerror(int value){
583
const char *ret = gnutls_strerror(value);
584
return safe_string(ret);
585
}
586
587
/* GnuTLS log function callback */
588
__attribute__((nonnull))
589
static void debuggnutls(__attribute__((unused)) int level,
590
const char* string){
591
fprintf_plus(stderr, "GnuTLS: %s", string);
592
}
593
594
__attribute__((nonnull(1, 2, 4), warn_unused_result))
595
static int init_gnutls_global(const char *pubkeyfilename,
596
const char *seckeyfilename,
597
const char *dhparamsfilename,
598
mandos_context *mc){
599
int ret;
600
unsigned int uret;
601
602
if(debug){
603
fprintf_plus(stderr, "Initializing GnuTLS\n");
604
}
605
606
if(debug){
607
/* "Use a log level over 10 to enable all debugging options."
608
* - GnuTLS manual
609
*/
610
gnutls_global_set_log_level(11);
611
gnutls_global_set_log_function(debuggnutls);
612
}
613
614
/* OpenPGP credentials */
615
ret = gnutls_certificate_allocate_credentials(&mc->cred);
616
if(ret != GNUTLS_E_SUCCESS){
617
fprintf_plus(stderr, "GnuTLS memory error: %s\n",
618
safer_gnutls_strerror(ret));
619
return -1;
620
}
621
622
if(debug){
623
fprintf_plus(stderr, "Attempting to use OpenPGP public key %s and"
624
" secret key %s as GnuTLS credentials\n",
625
pubkeyfilename,
626
seckeyfilename);
627
}
628
629
ret = gnutls_certificate_set_openpgp_key_file
630
(mc->cred, pubkeyfilename, seckeyfilename,
631
GNUTLS_OPENPGP_FMT_BASE64);
632
if(ret != GNUTLS_E_SUCCESS){
633
fprintf_plus(stderr,
634
"Error[%d] while reading the OpenPGP key pair ('%s',"
635
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
636
fprintf_plus(stderr, "The GnuTLS error is: %s\n",
637
safer_gnutls_strerror(ret));
638
goto globalfail;
639
}
640
641
/* GnuTLS server initialization */
642
ret = gnutls_dh_params_init(&mc->dh_params);
643
if(ret != GNUTLS_E_SUCCESS){
644
fprintf_plus(stderr, "Error in GnuTLS DH parameter"
645
" initialization: %s\n",
646
safer_gnutls_strerror(ret));
647
goto globalfail;
648
}
649
/* If a Diffie-Hellman parameters file was given, try to use it */
650
if(dhparamsfilename != NULL){
651
gnutls_datum_t params = { .data = NULL, .size = 0 };
652
do {
653
int dhpfile = open(dhparamsfilename, O_RDONLY);
654
if(dhpfile == -1){
655
perror_plus("open");
656
dhparamsfilename = NULL;
657
break;
658
}
659
size_t params_capacity = 0;
660
while(true){
661
params_capacity = incbuffer((char **)¶ms.data,
662
(size_t)params.size,
663
(size_t)params_capacity);
664
if(params_capacity == 0){
665
perror_plus("incbuffer");
666
free(params.data);
667
params.data = NULL;
668
dhparamsfilename = NULL;
669
break;
670
}
671
ssize_t bytes_read = read(dhpfile,
672
params.data + params.size,
673
BUFFER_SIZE);
674
/* EOF */
675
if(bytes_read == 0){
676
break;
677
}
678
/* check bytes_read for failure */
679
if(bytes_read < 0){
680
perror_plus("read");
681
free(params.data);
682
params.data = NULL;
683
dhparamsfilename = NULL;
684
break;
685
}
686
params.size += (unsigned int)bytes_read;
687
}
688
ret = close(dhpfile);
689
if(ret == -1){
690
perror_plus("close");
691
}
692
if(params.data == NULL){
693
dhparamsfilename = NULL;
694
}
695
if(dhparamsfilename == NULL){
696
break;
697
}
698
ret = gnutls_dh_params_import_pkcs3(mc->dh_params, ¶ms,
699
GNUTLS_X509_FMT_PEM);
700
if(ret != GNUTLS_E_SUCCESS){
701
fprintf_plus(stderr, "Failed to parse DH parameters in file"
702
" \"%s\": %s\n", dhparamsfilename,
703
safer_gnutls_strerror(ret));
704
dhparamsfilename = NULL;
705
}
706
free(params.data);
707
} while(false);
708
}
709
if(dhparamsfilename == NULL){
710
if(mc->dh_bits == 0){
711
/* Find out the optimal number of DH bits */
712
/* Try to read the private key file */
713
gnutls_datum_t buffer = { .data = NULL, .size = 0 };
714
do {
715
int secfile = open(seckeyfilename, O_RDONLY);
716
if(secfile == -1){
717
perror_plus("open");
718
break;
719
}
720
size_t buffer_capacity = 0;
721
while(true){
722
buffer_capacity = incbuffer((char **)&buffer.data,
723
(size_t)buffer.size,
724
(size_t)buffer_capacity);
725
if(buffer_capacity == 0){
726
perror_plus("incbuffer");
727
free(buffer.data);
728
buffer.data = NULL;
729
break;
730
}
731
ssize_t bytes_read = read(secfile,
732
buffer.data + buffer.size,
733
BUFFER_SIZE);
734
/* EOF */
735
if(bytes_read == 0){
736
break;
737
}
738
/* check bytes_read for failure */
739
if(bytes_read < 0){
740
perror_plus("read");
741
free(buffer.data);
742
buffer.data = NULL;
743
break;
744
}
745
buffer.size += (unsigned int)bytes_read;
746
}
747
close(secfile);
748
} while(false);
749
/* If successful, use buffer to parse private key */
750
gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;
751
if(buffer.data != NULL){
752
{
753
gnutls_openpgp_privkey_t privkey = NULL;
754
ret = gnutls_openpgp_privkey_init(&privkey);
755
if(ret != GNUTLS_E_SUCCESS){
756
fprintf_plus(stderr, "Error initializing OpenPGP key"
757
" structure: %s",
758
safer_gnutls_strerror(ret));
759
free(buffer.data);
760
buffer.data = NULL;
761
} else {
762
ret = gnutls_openpgp_privkey_import
763
(privkey, &buffer, GNUTLS_OPENPGP_FMT_BASE64, "", 0);
764
if(ret != GNUTLS_E_SUCCESS){
765
fprintf_plus(stderr, "Error importing OpenPGP key : %s",
766
safer_gnutls_strerror(ret));
767
privkey = NULL;
768
}
769
free(buffer.data);
770
buffer.data = NULL;
771
if(privkey != NULL){
772
/* Use private key to suggest an appropriate
773
sec_param */
774
sec_param = gnutls_openpgp_privkey_sec_param(privkey);
775
gnutls_openpgp_privkey_deinit(privkey);
776
if(debug){
777
fprintf_plus(stderr, "This OpenPGP key implies using"
778
" a GnuTLS security parameter \"%s\".\n",
779
safe_string(gnutls_sec_param_get_name
780
(sec_param)));
781
}
782
}
783
}
784
}
785
if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){
786
/* Err on the side of caution */
787
sec_param = GNUTLS_SEC_PARAM_ULTRA;
788
if(debug){
789
fprintf_plus(stderr, "Falling back to security parameter"
790
" \"%s\"\n",
791
safe_string(gnutls_sec_param_get_name
792
(sec_param)));
793
}
794
}
795
}
796
uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);
797
if(uret != 0){
798
mc->dh_bits = uret;
799
if(debug){
800
fprintf_plus(stderr, "A \"%s\" GnuTLS security parameter"
801
" implies %u DH bits; using that.\n",
802
safe_string(gnutls_sec_param_get_name
803
(sec_param)),
804
mc->dh_bits);
805
}
806
} else {
807
fprintf_plus(stderr, "Failed to get implied number of DH"
808
" bits for security parameter \"%s\"): %s\n",
809
safe_string(gnutls_sec_param_get_name
810
(sec_param)),
811
safer_gnutls_strerror(ret));
812
goto globalfail;
813
}
814
} else if(debug){
815
fprintf_plus(stderr, "DH bits explicitly set to %u\n",
816
mc->dh_bits);
817
}
818
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
819
if(ret != GNUTLS_E_SUCCESS){
820
fprintf_plus(stderr, "Error in GnuTLS prime generation (%u"
821
" bits): %s\n", mc->dh_bits,
822
safer_gnutls_strerror(ret));
823
goto globalfail;
824
}
825
}
826
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
827
828
return 0;
829
830
globalfail:
831
832
gnutls_certificate_free_credentials(mc->cred);
833
gnutls_dh_params_deinit(mc->dh_params);
834
return -1;
835
}
836
837
__attribute__((nonnull, warn_unused_result))
838
static int init_gnutls_session(gnutls_session_t *session,
839
mandos_context *mc){
840
int ret;
841
/* GnuTLS session creation */
842
do {
843
ret = gnutls_init(session, GNUTLS_SERVER);
844
if(quit_now){
845
return -1;
846
}
847
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
848
if(ret != GNUTLS_E_SUCCESS){
849
fprintf_plus(stderr,
850
"Error in GnuTLS session initialization: %s\n",
851
safer_gnutls_strerror(ret));
852
}
853
854
{
855
const char *err;
856
do {
857
ret = gnutls_priority_set_direct(*session, mc->priority, &err);
858
if(quit_now){
859
gnutls_deinit(*session);
860
return -1;
861
}
862
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
863
if(ret != GNUTLS_E_SUCCESS){
864
fprintf_plus(stderr, "Syntax error at: %s\n", err);
865
fprintf_plus(stderr, "GnuTLS error: %s\n",
866
safer_gnutls_strerror(ret));
867
gnutls_deinit(*session);
868
return -1;
869
}
870
}
871
872
do {
873
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
874
mc->cred);
875
if(quit_now){
876
gnutls_deinit(*session);
877
return -1;
878
}
879
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
880
if(ret != GNUTLS_E_SUCCESS){
881
fprintf_plus(stderr, "Error setting GnuTLS credentials: %s\n",
882
safer_gnutls_strerror(ret));
883
gnutls_deinit(*session);
884
return -1;
885
}
886
887
/* ignore client certificate if any. */
888
gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);
889
890
return 0;
891
}
892
893
/* Avahi log function callback */
894
static void empty_log(__attribute__((unused)) AvahiLogLevel level,
895
__attribute__((unused)) const char *txt){}
896
897
/* Set effective uid to 0, return errno */
898
__attribute__((warn_unused_result))
899
int raise_privileges(void){
900
int old_errno = errno;
901
int ret = 0;
902
if(seteuid(0) == -1){
903
ret = errno;
904
}
905
errno = old_errno;
906
return ret;
907
}
908
909
/* Set effective and real user ID to 0. Return errno. */
910
__attribute__((warn_unused_result))
911
int raise_privileges_permanently(void){
912
int old_errno = errno;
913
int ret = raise_privileges();
914
if(ret != 0){
915
errno = old_errno;
916
return ret;
917
}
918
if(setuid(0) == -1){
919
ret = errno;
920
}
921
errno = old_errno;
922
return ret;
923
}
924
925
/* Set effective user ID to unprivileged saved user ID */
926
__attribute__((warn_unused_result))
927
int lower_privileges(void){
928
int old_errno = errno;
929
int ret = 0;
930
if(seteuid(uid) == -1){
931
ret = errno;
932
}
933
errno = old_errno;
934
return ret;
935
}
936
937
/* Lower privileges permanently */
938
__attribute__((warn_unused_result))
939
int lower_privileges_permanently(void){
940
int old_errno = errno;
941
int ret = 0;
942
if(setuid(uid) == -1){
943
ret = errno;
944
}
945
errno = old_errno;
946
return ret;
947
}
948
949
/* Helper function to add_local_route() and delete_local_route() */
950
__attribute__((nonnull, warn_unused_result))
951
static bool add_delete_local_route(const bool add,
952
const char *address,
953
AvahiIfIndex if_index){
954
int ret;
955
char helper[] = "mandos-client-iprouteadddel";
956
char add_arg[] = "add";
957
char delete_arg[] = "delete";
958
char debug_flag[] = "--debug";
959
char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");
960
if(pluginhelperdir == NULL){
961
if(debug){
962
fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"
963
" variable not set; cannot run helper\n");
964
}
965
return false;
966
}
967
968
char interface[IF_NAMESIZE];
969
if(if_indextoname((unsigned int)if_index, interface) == NULL){
970
perror_plus("if_indextoname");
971
return false;
972
}
973
974
int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));
975
if(devnull == -1){
976
perror_plus("open(\"/dev/null\", O_RDONLY)");
977
return false;
978
}
979
pid_t pid = fork();
980
if(pid == 0){
981
/* Child */
982
/* Raise privileges */
983
errno = raise_privileges_permanently();
984
if(errno != 0){
985
perror_plus("Failed to raise privileges");
986
/* _exit(EX_NOPERM); */
987
} else {
988
/* Set group */
989
errno = 0;
990
ret = setgid(0);
991
if(ret == -1){
992
perror_plus("setgid");
993
_exit(EX_NOPERM);
994
}
995
/* Reset supplementary groups */
996
errno = 0;
997
ret = setgroups(0, NULL);
998
if(ret == -1){
999
perror_plus("setgroups");
1000
_exit(EX_NOPERM);
1001
}
1002
}
1003
ret = dup2(devnull, STDIN_FILENO);
1004
if(ret == -1){
1005
perror_plus("dup2(devnull, STDIN_FILENO)");
1006
_exit(EX_OSERR);
1007
}
1008
ret = close(devnull);
1009
if(ret == -1){
1010
perror_plus("close");
1011
_exit(EX_OSERR);
1012
}
1013
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
1014
if(ret == -1){
1015
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
1016
_exit(EX_OSERR);
1017
}
1018
int helperdir_fd = (int)TEMP_FAILURE_RETRY(open(pluginhelperdir,
1019
O_RDONLY
1020
| O_DIRECTORY
1021
| O_PATH
1022
| O_CLOEXEC));
1023
if(helperdir_fd == -1){
1024
perror_plus("open");
1025
_exit(EX_UNAVAILABLE);
1026
}
1027
int helper_fd = (int)TEMP_FAILURE_RETRY(openat(helperdir_fd,
1028
helper, O_RDONLY));
1029
if(helper_fd == -1){
1030
perror_plus("openat");
1031
close(helperdir_fd);
1032
_exit(EX_UNAVAILABLE);
1033
}
1034
close(helperdir_fd);
1035
#ifdef __GNUC__
1036
#pragma GCC diagnostic push
1037
#pragma GCC diagnostic ignored "-Wcast-qual"
1038
#endif
1039
if(fexecve(helper_fd, (char *const [])
1040
{ helper, add ? add_arg : delete_arg, (char *)address,
1041
interface, debug ? debug_flag : NULL, NULL },
1042
environ) == -1){
1043
#ifdef __GNUC__
1044
#pragma GCC diagnostic pop
1045
#endif
1046
perror_plus("fexecve");
1047
_exit(EXIT_FAILURE);
1048
}
1049
}
1050
if(pid == -1){
1051
perror_plus("fork");
1052
return false;
1053
}
1054
int status;
1055
pid_t pret = -1;
1056
errno = 0;
1057
do {
1058
pret = waitpid(pid, &status, 0);
1059
if(pret == -1 and errno == EINTR and quit_now){
1060
int errno_raising = 0;
1061
if((errno = raise_privileges()) != 0){
1062
errno_raising = errno;
1063
perror_plus("Failed to raise privileges in order to"
1064
" kill helper program");
1065
}
1066
if(kill(pid, SIGTERM) == -1){
1067
perror_plus("kill");
1068
}
1069
if((errno_raising == 0) and (errno = lower_privileges()) != 0){
1070
perror_plus("Failed to lower privileges after killing"
1071
" helper program");
1072
}
1073
return false;
1074
}
1075
} while(pret == -1 and errno == EINTR);
1076
if(pret == -1){
1077
perror_plus("waitpid");
1078
return false;
1079
}
1080
if(WIFEXITED(status)){
1081
if(WEXITSTATUS(status) != 0){
1082
fprintf_plus(stderr, "Error: iprouteadddel exited"
1083
" with status %d\n", WEXITSTATUS(status));
1084
return false;
1085
}
1086
return true;
1087
}
1088
if(WIFSIGNALED(status)){
1089
fprintf_plus(stderr, "Error: iprouteadddel died by"
1090
" signal %d\n", WTERMSIG(status));
1091
return false;
1092
}
1093
fprintf_plus(stderr, "Error: iprouteadddel crashed\n");
1094
return false;
1095
}
1096
1097
__attribute__((nonnull, warn_unused_result))
1098
static bool add_local_route(const char *address,
1099
AvahiIfIndex if_index){
1100
if(debug){
1101
fprintf_plus(stderr, "Adding route to %s\n", address);
1102
}
1103
return add_delete_local_route(true, address, if_index);
1104
}
1105
1106
__attribute__((nonnull, warn_unused_result))
1107
static bool delete_local_route(const char *address,
1108
AvahiIfIndex if_index){
1109
if(debug){
1110
fprintf_plus(stderr, "Removing route to %s\n", address);
1111
}
1112
return add_delete_local_route(false, address, if_index);
1113
}
1114
1115
/* Called when a Mandos server is found */
1116
__attribute__((nonnull, warn_unused_result))
1117
static int start_mandos_communication(const char *ip, in_port_t port,
1118
AvahiIfIndex if_index,
1119
int af, mandos_context *mc){
1120
int ret, tcp_sd = -1;
1121
ssize_t sret;
1122
struct sockaddr_storage to;
1123
char *buffer = NULL;
1124
char *decrypted_buffer = NULL;
1125
size_t buffer_length = 0;
1126
size_t buffer_capacity = 0;
1127
size_t written;
1128
int retval = -1;
1129
gnutls_session_t session;
1130
int pf; /* Protocol family */
1131
bool route_added = false;
1132
1133
errno = 0;
1134
1135
if(quit_now){
1136
errno = EINTR;
1137
return -1;
1138
}
1139
1140
switch(af){
1141
case AF_INET6:
1142
pf = PF_INET6;
1143
break;
1144
case AF_INET:
1145
pf = PF_INET;
1146
break;
1147
default:
1148
fprintf_plus(stderr, "Bad address family: %d\n", af);
1149
errno = EINVAL;
1150
return -1;
1151
}
1152
1153
/* If the interface is specified and we have a list of interfaces */
1154
if(if_index != AVAHI_IF_UNSPEC and mc->interfaces != NULL){
1155
/* Check if the interface is one of the interfaces we are using */
1156
bool match = false;
1157
{
1158
char *interface = NULL;
1159
while((interface = argz_next(mc->interfaces,
1160
mc->interfaces_size,
1161
interface))){
1162
if(if_nametoindex(interface) == (unsigned int)if_index){
1163
match = true;
1164
break;
1165
}
1166
}
1167
}
1168
if(not match){
1169
/* This interface does not match any in the list, so we don't
1170
connect to the server */
1171
if(debug){
1172
char interface[IF_NAMESIZE];
1173
if(if_indextoname((unsigned int)if_index, interface) == NULL){
1174
perror_plus("if_indextoname");
1175
} else {
1176
fprintf_plus(stderr, "Skipping server on non-used interface"
1177
" \"%s\"\n",
1178
if_indextoname((unsigned int)if_index,
1179
interface));
1180
}
1181
}
1182
return -1;
1183
}
1184
}
1185
1186
ret = init_gnutls_session(&session, mc);
1187
if(ret != 0){
1188
return -1;
1189
}
1190
1191
if(debug){
1192
fprintf_plus(stderr, "Setting up a TCP connection to %s, port %"
1193
PRIuMAX "\n", ip, (uintmax_t)port);
1194
}
1195
1196
tcp_sd = socket(pf, SOCK_STREAM | SOCK_CLOEXEC, 0);
1197
if(tcp_sd < 0){
1198
int e = errno;
1199
perror_plus("socket");
1200
errno = e;
1201
goto mandos_end;
1202
}
1203
1204
if(quit_now){
1205
errno = EINTR;
1206
goto mandos_end;
1207
}
1208
1209
if(af == AF_INET6){
1210
struct sockaddr_in6 *to6 = (struct sockaddr_in6 *)&to;
1211
*to6 = (struct sockaddr_in6){ .sin6_family = (sa_family_t)af };
1212
ret = inet_pton(af, ip, &to6->sin6_addr);
1213
} else { /* IPv4 */
1214
struct sockaddr_in *to4 = (struct sockaddr_in *)&to;
1215
*to4 = (struct sockaddr_in){ .sin_family = (sa_family_t)af };
1216
ret = inet_pton(af, ip, &to4->sin_addr);
1217
}
1218
if(ret < 0 ){
1219
int e = errno;
1220
perror_plus("inet_pton");
1221
errno = e;
1222
goto mandos_end;
1223
}
1224
if(ret == 0){
1225
int e = errno;
1226
fprintf_plus(stderr, "Bad address: %s\n", ip);
1227
errno = e;
1228
goto mandos_end;
1229
}
1230
if(af == AF_INET6){
1231
((struct sockaddr_in6 *)&to)->sin6_port = htons(port);
1232
if(IN6_IS_ADDR_LINKLOCAL
1233
(&((struct sockaddr_in6 *)&to)->sin6_addr)){
1234
if(if_index == AVAHI_IF_UNSPEC){
1235
fprintf_plus(stderr, "An IPv6 link-local address is"
1236
" incomplete without a network interface\n");
1237
errno = EINVAL;
1238
goto mandos_end;
1239
}
1240
/* Set the network interface number as scope */
1241
((struct sockaddr_in6 *)&to)->sin6_scope_id = (uint32_t)if_index;
1242
}
1243
} else {
1244
((struct sockaddr_in *)&to)->sin_port = htons(port);
1245
}
1246
1247
if(quit_now){
1248
errno = EINTR;
1249
goto mandos_end;
1250
}
1251
1252
if(debug){
1253
if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){
1254
char interface[IF_NAMESIZE];
1255
if(if_indextoname((unsigned int)if_index, interface) == NULL){
1256
perror_plus("if_indextoname");
1257
} else {
1258
fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIuMAX
1259
"\n", ip, interface, (uintmax_t)port);
1260
}
1261
} else {
1262
fprintf_plus(stderr, "Connection to: %s, port %" PRIuMAX "\n",
1263
ip, (uintmax_t)port);
1264
}
1265
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
1266
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
1267
if(af == AF_INET6){
1268
ret = getnameinfo((struct sockaddr *)&to,
1269
sizeof(struct sockaddr_in6),
1270
addrstr, sizeof(addrstr), NULL, 0,
1271
NI_NUMERICHOST);
1272
} else {
1273
ret = getnameinfo((struct sockaddr *)&to,
1274
sizeof(struct sockaddr_in),
1275
addrstr, sizeof(addrstr), NULL, 0,
1276
NI_NUMERICHOST);
1277
}
1278
if(ret == EAI_SYSTEM){
1279
perror_plus("getnameinfo");
1280
} else if(ret != 0) {
1281
fprintf_plus(stderr, "getnameinfo: %s", gai_strerror(ret));
1282
} else if(strcmp(addrstr, ip) != 0){
1283
fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);
1284
}
1285
}
1286
1287
if(quit_now){
1288
errno = EINTR;
1289
goto mandos_end;
1290
}
1291
1292
while(true){
1293
if(af == AF_INET6){
1294
ret = connect(tcp_sd, (struct sockaddr *)&to,
1295
sizeof(struct sockaddr_in6));
1296
} else {
1297
ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */
1298
sizeof(struct sockaddr_in));
1299
}
1300
if(ret < 0){
1301
if(((errno == ENETUNREACH) or (errno == EHOSTUNREACH))
1302
and if_index != AVAHI_IF_UNSPEC
1303
and connect_to == NULL
1304
and not route_added and
1305
((af == AF_INET6 and not
1306
IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)
1307
&to)->sin6_addr)))
1308
or (af == AF_INET and
1309
/* Not a a IPv4LL address */
1310
(ntohl(((struct sockaddr_in *)&to)->sin_addr.s_addr)
1311
& 0xFFFF0000L) != 0xA9FE0000L))){
1312
/* Work around Avahi bug - Avahi does not announce link-local
1313
addresses if it has a global address, so local hosts with
1314
*only* a link-local address (e.g. Mandos clients) cannot
1315
connect to a Mandos server announced by Avahi on a server
1316
host with a global address. Work around this by retrying
1317
with an explicit route added with the server's address.
1318
1319
Avahi bug reference:
1320
https://lists.freedesktop.org/archives/avahi/2010-February/001833.html
1321
https://bugs.debian.org/587961
1322
*/
1323
if(debug){
1324
fprintf_plus(stderr, "Mandos server unreachable, trying"
1325
" direct route\n");
1326
}
1327
int e = errno;
1328
route_added = add_local_route(ip, if_index);
1329
if(route_added){
1330
continue;
1331
}
1332
errno = e;
1333
}
1334
if(errno != ECONNREFUSED or debug){
1335
int e = errno;
1336
perror_plus("connect");
1337
errno = e;
1338
}
1339
goto mandos_end;
1340
}
1341
1342
if(quit_now){
1343
errno = EINTR;
1344
goto mandos_end;
1345
}
1346
break;
1347
}
1348
1349
const char *out = mandos_protocol_version;
1350
written = 0;
1351
while(true){
1352
size_t out_size = strlen(out);
1353
ret = (int)TEMP_FAILURE_RETRY(write(tcp_sd, out + written,
1354
out_size - written));
1355
if(ret == -1){
1356
int e = errno;
1357
perror_plus("write");
1358
errno = e;
1359
goto mandos_end;
1360
}
1361
written += (size_t)ret;
1362
if(written < out_size){
1363
continue;
1364
} else {
1365
if(out == mandos_protocol_version){
1366
written = 0;
1367
out = "\r\n";
1368
} else {
1369
break;
1370
}
1371
}
1372
1373
if(quit_now){
1374
errno = EINTR;
1375
goto mandos_end;
1376
}
1377
}
1378
1379
if(debug){
1380
fprintf_plus(stderr, "Establishing TLS session with %s\n", ip);
1381
}
1382
1383
if(quit_now){
1384
errno = EINTR;
1385
goto mandos_end;
1386
}
1387
1388
/* This casting via intptr_t is to eliminate warning about casting
1389
an int to a pointer type. This is exactly how the GnuTLS Guile
1390
function "set-session-transport-fd!" does it. */
1391
gnutls_transport_set_ptr(session,
1392
(gnutls_transport_ptr_t)(intptr_t)tcp_sd);
1393
1394
if(quit_now){
1395
errno = EINTR;
1396
goto mandos_end;
1397
}
1398
1399
do {
1400
ret = gnutls_handshake(session);
1401
if(quit_now){
1402
errno = EINTR;
1403
goto mandos_end;
1404
}
1405
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
1406
1407
if(ret != GNUTLS_E_SUCCESS){
1408
if(debug){
1409
fprintf_plus(stderr, "*** GnuTLS Handshake failed ***\n");
1410
gnutls_perror(ret);
1411
}
1412
errno = EPROTO;
1413
goto mandos_end;
1414
}
1415
1416
/* Read OpenPGP packet that contains the wanted password */
1417
1418
if(debug){
1419
fprintf_plus(stderr, "Retrieving OpenPGP encrypted password from"
1420
" %s\n", ip);
1421
}
1422
1423
while(true){
1424
1425
if(quit_now){
1426
errno = EINTR;
1427
goto mandos_end;
1428
}
1429
1430
buffer_capacity = incbuffer(&buffer, buffer_length,
1431
buffer_capacity);
1432
if(buffer_capacity == 0){
1433
int e = errno;
1434
perror_plus("incbuffer");
1435
errno = e;
1436
goto mandos_end;
1437
}
1438
1439
if(quit_now){
1440
errno = EINTR;
1441
goto mandos_end;
1442
}
1443
1444
sret = gnutls_record_recv(session, buffer+buffer_length,
1445
BUFFER_SIZE);
1446
if(sret == 0){
1447
break;
1448
}
1449
if(sret < 0){
1450
switch(sret){
1451
case GNUTLS_E_INTERRUPTED:
1452
case GNUTLS_E_AGAIN:
1453
break;
1454
case GNUTLS_E_REHANDSHAKE:
1455
do {
1456
ret = gnutls_handshake(session);
1457
1458
if(quit_now){
1459
errno = EINTR;
1460
goto mandos_end;
1461
}
1462
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
1463
if(ret < 0){
1464
fprintf_plus(stderr, "*** GnuTLS Re-handshake failed "
1465
"***\n");
1466
gnutls_perror(ret);
1467
errno = EPROTO;
1468
goto mandos_end;
1469
}
1470
break;
1471
default:
1472
fprintf_plus(stderr, "Unknown error while reading data from"
1473
" encrypted session with Mandos server\n");
1474
gnutls_bye(session, GNUTLS_SHUT_RDWR);
1475
errno = EIO;
1476
goto mandos_end;
1477
}
1478
} else {
1479
buffer_length += (size_t) sret;
1480
}
1481
}
1482
1483
if(debug){
1484
fprintf_plus(stderr, "Closing TLS session\n");
1485
}
1486
1487
if(quit_now){
1488
errno = EINTR;
1489
goto mandos_end;
1490
}
1491
1492
do {
1493
ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);
1494
if(quit_now){
1495
errno = EINTR;
1496
goto mandos_end;
1497
}
1498
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
1499
1500
if(buffer_length > 0){
1501
ssize_t decrypted_buffer_size;
1502
decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,
1503
&decrypted_buffer, mc);
1504
if(decrypted_buffer_size >= 0){
1505
1506
clearerr(stdout);
1507
written = 0;
1508
while(written < (size_t) decrypted_buffer_size){
1509
if(quit_now){
1510
errno = EINTR;
1511
goto mandos_end;
1512
}
1513
1514
ret = (int)fwrite(decrypted_buffer + written, 1,
1515
(size_t)decrypted_buffer_size - written,
1516
stdout);
1517
if(ret == 0 and ferror(stdout)){
1518
int e = errno;
1519
if(debug){
1520
fprintf_plus(stderr, "Error writing encrypted data: %s\n",
1521
strerror(errno));
1522
}
1523
errno = e;
1524
goto mandos_end;
1525
}
1526
written += (size_t)ret;
1527
}
1528
ret = fflush(stdout);
1529
if(ret != 0){
1530
int e = errno;
1531
if(debug){
1532
fprintf_plus(stderr, "Error writing encrypted data: %s\n",
1533
strerror(errno));
1534
}
1535
errno = e;
1536
goto mandos_end;
1537
}
1538
retval = 0;
1539
}
1540
}
1541
1542
/* Shutdown procedure */
1543
1544
mandos_end:
1545
{
1546
if(route_added){
1547
if(not delete_local_route(ip, if_index)){
1548
fprintf_plus(stderr, "Failed to delete local route to %s on"
1549
" interface %d", ip, if_index);
1550
}
1551
}
1552
int e = errno;
1553
free(decrypted_buffer);
1554
free(buffer);
1555
if(tcp_sd >= 0){
1556
ret = close(tcp_sd);
1557
}
1558
if(ret == -1){
1559
if(e == 0){
1560
e = errno;
1561
}
1562
perror_plus("close");
1563
}
1564
gnutls_deinit(session);
1565
errno = e;
1566
if(quit_now){
1567
errno = EINTR;
1568
retval = -1;
1569
}
1570
}
1571
return retval;
1572
}
1573
1574
static void resolve_callback(AvahiSServiceResolver *r,
1575
AvahiIfIndex interface,
1576
AvahiProtocol proto,
1577
AvahiResolverEvent event,
1578
const char *name,
1579
const char *type,
1580
const char *domain,
1581
const char *host_name,
1582
const AvahiAddress *address,
1583
uint16_t port,
1584
AVAHI_GCC_UNUSED AvahiStringList *txt,
1585
AVAHI_GCC_UNUSED AvahiLookupResultFlags
1586
flags,
1587
void *mc){
1588
if(r == NULL){
1589
return;
1590
}
1591
1592
/* Called whenever a service has been resolved successfully or
1593
timed out */
1594
1595
if(quit_now){
1596
avahi_s_service_resolver_free(r);
1597
return;
1598
}
1599
1600
switch(event){
1601
default:
1602
case AVAHI_RESOLVER_FAILURE:
1603
fprintf_plus(stderr, "(Avahi Resolver) Failed to resolve service "
1604
"'%s' of type '%s' in domain '%s': %s\n", name, type,
1605
domain,
1606
avahi_strerror(avahi_server_errno
1607
(((mandos_context*)mc)->server)));
1608
break;
1609
1610
case AVAHI_RESOLVER_FOUND:
1611
{
1612
char ip[AVAHI_ADDRESS_STR_MAX];
1613
avahi_address_snprint(ip, sizeof(ip), address);
1614
if(debug){
1615
fprintf_plus(stderr, "Mandos server \"%s\" found on %s (%s, %"
1616
PRIdMAX ") on port %" PRIu16 "\n", name,
1617
host_name, ip, (intmax_t)interface, port);
1618
}
1619
int ret = start_mandos_communication(ip, (in_port_t)port,
1620
interface,
1621
avahi_proto_to_af(proto),
1622
mc);
1623
if(ret == 0){
1624
avahi_simple_poll_quit(simple_poll);
1625
} else {
1626
if(not add_server(ip, (in_port_t)port, interface,
1627
avahi_proto_to_af(proto),
1628
&((mandos_context*)mc)->current_server)){
1629
fprintf_plus(stderr, "Failed to add server \"%s\" to server"
1630
" list\n", name);
1631
}
1632
}
1633
}
1634
}
1635
avahi_s_service_resolver_free(r);
1636
}
1637
1638
static void browse_callback(AvahiSServiceBrowser *b,
1639
AvahiIfIndex interface,
1640
AvahiProtocol protocol,
1641
AvahiBrowserEvent event,
1642
const char *name,
1643
const char *type,
1644
const char *domain,
1645
AVAHI_GCC_UNUSED AvahiLookupResultFlags
1646
flags,
1647
void *mc){
1648
if(b == NULL){
1649
return;
1650
}
1651
1652
/* Called whenever a new services becomes available on the LAN or
1653
is removed from the LAN */
1654
1655
if(quit_now){
1656
return;
1657
}
1658
1659
switch(event){
1660
default:
1661
case AVAHI_BROWSER_FAILURE:
1662
1663
fprintf_plus(stderr, "(Avahi browser) %s\n",
1664
avahi_strerror(avahi_server_errno
1665
(((mandos_context*)mc)->server)));
1666
avahi_simple_poll_quit(simple_poll);
1667
return;
1668
1669
case AVAHI_BROWSER_NEW:
1670
/* We ignore the returned Avahi resolver object. In the callback
1671
function we free it. If the Avahi server is terminated before
1672
the callback function is called the Avahi server will free the
1673
resolver for us. */
1674
1675
if(avahi_s_service_resolver_new(((mandos_context*)mc)->server,
1676
interface, protocol, name, type,
1677
domain, protocol, 0,
1678
resolve_callback, mc) == NULL)
1679
fprintf_plus(stderr, "Avahi: Failed to resolve service '%s':"
1680
" %s\n", name,
1681
avahi_strerror(avahi_server_errno
1682
(((mandos_context*)mc)->server)));
1683
break;
1684
1685
case AVAHI_BROWSER_REMOVE:
1686
break;
1687
1688
case AVAHI_BROWSER_ALL_FOR_NOW:
1689
case AVAHI_BROWSER_CACHE_EXHAUSTED:
1690
if(debug){
1691
fprintf_plus(stderr, "No Mandos server found, still"
1692
" searching...\n");
1693
}
1694
break;
1695
}
1696
}
1697
1698
/* Signal handler that stops main loop after SIGTERM */
1699
static void handle_sigterm(int sig){
1700
if(quit_now){
1701
return;
1702
}
1703
quit_now = 1;
1704
signal_received = sig;
1705
int old_errno = errno;
1706
/* set main loop to exit */
1707
if(simple_poll != NULL){
1708
avahi_simple_poll_quit(simple_poll);
1709
}
1710
errno = old_errno;
1711
}
1712
1713
__attribute__((nonnull, warn_unused_result))
1714
bool get_flags(const char *ifname, struct ifreq *ifr){
1715
int ret;
1716
int old_errno;
1717
1718
int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1719
if(s < 0){
1720
old_errno = errno;
1721
perror_plus("socket");
1722
errno = old_errno;
1723
return false;
1724
}
1725
strncpy(ifr->ifr_name, ifname, IF_NAMESIZE);
1726
ifr->ifr_name[IF_NAMESIZE-1] = '\0'; /* NUL terminate */
1727
ret = ioctl(s, SIOCGIFFLAGS, ifr);
1728
if(ret == -1){
1729
if(debug){
1730
old_errno = errno;
1731
perror_plus("ioctl SIOCGIFFLAGS");
1732
errno = old_errno;
1733
}
1734
if((close(s) == -1) and debug){
1735
old_errno = errno;
1736
perror_plus("close");
1737
errno = old_errno;
1738
}
1739
return false;
1740
}
1741
if((close(s) == -1) and debug){
1742
old_errno = errno;
1743
perror_plus("close");
1744
errno = old_errno;
1745
}
1746
return true;
1747
}
1748
1749
__attribute__((nonnull, warn_unused_result))
1750
bool good_flags(const char *ifname, const struct ifreq *ifr){
1751
1752
/* Reject the loopback device */
1753
if(ifr->ifr_flags & IFF_LOOPBACK){
1754
if(debug){
1755
fprintf_plus(stderr, "Rejecting loopback interface \"%s\"\n",
1756
ifname);
1757
}
1758
return false;
1759
}
1760
/* Accept point-to-point devices only if connect_to is specified */
1761
if(connect_to != NULL and (ifr->ifr_flags & IFF_POINTOPOINT)){
1762
if(debug){
1763
fprintf_plus(stderr, "Accepting point-to-point interface"
1764
" \"%s\"\n", ifname);
1765
}
1766
return true;
1767
}
1768
/* Otherwise, reject non-broadcast-capable devices */
1769
if(not (ifr->ifr_flags & IFF_BROADCAST)){
1770
if(debug){
1771
fprintf_plus(stderr, "Rejecting non-broadcast interface"
1772
" \"%s\"\n", ifname);
1773
}
1774
return false;
1775
}
1776
/* Reject non-ARP interfaces (including dummy interfaces) */
1777
if(ifr->ifr_flags & IFF_NOARP){
1778
if(debug){
1779
fprintf_plus(stderr, "Rejecting non-ARP interface \"%s\"\n",
1780
ifname);
1781
}
1782
return false;
1783
}
1784
1785
/* Accept this device */
1786
if(debug){
1787
fprintf_plus(stderr, "Interface \"%s\" is good\n", ifname);
1788
}
1789
return true;
1790
}
1791
1792
/*
1793
* This function determines if a directory entry in /sys/class/net
1794
* corresponds to an acceptable network device.
1795
* (This function is passed to scandir(3) as a filter function.)
1796
*/
1797
__attribute__((nonnull, warn_unused_result))
1798
int good_interface(const struct dirent *if_entry){
1799
if(if_entry->d_name[0] == '.'){
1800
return 0;
1801
}
1802
1803
struct ifreq ifr;
1804
if(not get_flags(if_entry->d_name, &ifr)){
1805
if(debug){
1806
fprintf_plus(stderr, "Failed to get flags for interface "
1807
"\"%s\"\n", if_entry->d_name);
1808
}
1809
return 0;
1810
}
1811
1812
if(not good_flags(if_entry->d_name, &ifr)){
1813
return 0;
1814
}
1815
return 1;
1816
}
1817
1818
/*
1819
* This function determines if a network interface is up.
1820
*/
1821
__attribute__((nonnull, warn_unused_result))
1822
bool interface_is_up(const char *interface){
1823
struct ifreq ifr;
1824
if(not get_flags(interface, &ifr)){
1825
if(debug){
1826
fprintf_plus(stderr, "Failed to get flags for interface "
1827
"\"%s\"\n", interface);
1828
}
1829
return false;
1830
}
1831
1832
return (bool)(ifr.ifr_flags & IFF_UP);
1833
}
1834
1835
/*
1836
* This function determines if a network interface is running
1837
*/
1838
__attribute__((nonnull, warn_unused_result))
1839
bool interface_is_running(const char *interface){
1840
struct ifreq ifr;
1841
if(not get_flags(interface, &ifr)){
1842
if(debug){
1843
fprintf_plus(stderr, "Failed to get flags for interface "
1844
"\"%s\"\n", interface);
1845
}
1846
return false;
1847
}
1848
1849
return (bool)(ifr.ifr_flags & IFF_RUNNING);
1850
}
1851
1852
__attribute__((nonnull, pure, warn_unused_result))
1853
int notdotentries(const struct dirent *direntry){
1854
/* Skip "." and ".." */
1855
if(direntry->d_name[0] == '.'
1856
and (direntry->d_name[1] == '\0'
1857
or (direntry->d_name[1] == '.'
1858
and direntry->d_name[2] == '\0'))){
1859
return 0;
1860
}
1861
return 1;
1862
}
1863
1864
/* Is this directory entry a runnable program? */
1865
__attribute__((nonnull, warn_unused_result))
1866
int runnable_hook(const struct dirent *direntry){
1867
int ret;
1868
size_t sret;
1869
struct stat st;
1870
1871
if((direntry->d_name)[0] == '\0'){
1872
/* Empty name? */
1873
return 0;
1874
}
1875
1876
sret = strspn(direntry->d_name, "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
1877
"abcdefghijklmnopqrstuvwxyz"
1878
"0123456789"
1879
"_.-");
1880
if((direntry->d_name)[sret] != '\0'){
1881
/* Contains non-allowed characters */
1882
if(debug){
1883
fprintf_plus(stderr, "Ignoring hook \"%s\" with bad name\n",
1884
direntry->d_name);
1885
}
1886
return 0;
1887
}
1888
1889
ret = fstatat(hookdir_fd, direntry->d_name, &st, 0);
1890
if(ret == -1){
1891
if(debug){
1892
perror_plus("Could not stat hook");
1893
}
1894
return 0;
1895
}
1896
if(not (S_ISREG(st.st_mode))){
1897
/* Not a regular file */
1898
if(debug){
1899
fprintf_plus(stderr, "Ignoring hook \"%s\" - not a file\n",
1900
direntry->d_name);
1901
}
1902
return 0;
1903
}
1904
if(not (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))){
1905
/* Not executable */
1906
if(debug){
1907
fprintf_plus(stderr, "Ignoring hook \"%s\" - not executable\n",
1908
direntry->d_name);
1909
}
1910
return 0;
1911
}
1912
if(debug){
1913
fprintf_plus(stderr, "Hook \"%s\" is acceptable\n",
1914
direntry->d_name);
1915
}
1916
return 1;
1917
}
1918
1919
__attribute__((nonnull, warn_unused_result))
1920
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,
1921
mandos_context *mc){
1922
int ret;
1923
struct timespec now;
1924
struct timespec waited_time;
1925
intmax_t block_time;
1926
1927
while(true){
1928
if(mc->current_server == NULL){
1929
if(debug){
1930
fprintf_plus(stderr, "Wait until first server is found."
1931
" No timeout!\n");
1932
}
1933
ret = avahi_simple_poll_iterate(s, -1);
1934
} else {
1935
if(debug){
1936
fprintf_plus(stderr, "Check current_server if we should run"
1937
" it, or wait\n");
1938
}
1939
/* the current time */
1940
ret = clock_gettime(CLOCK_MONOTONIC, &now);
1941
if(ret == -1){
1942
perror_plus("clock_gettime");
1943
return -1;
1944
}
1945
/* Calculating in ms how long time between now and server
1946
who we visted longest time ago. Now - last seen. */
1947
waited_time.tv_sec = (now.tv_sec
1948
- mc->current_server->last_seen.tv_sec);
1949
waited_time.tv_nsec = (now.tv_nsec
1950
- mc->current_server->last_seen.tv_nsec);
1951
/* total time is 10s/10,000ms.
1952
Converting to s from ms by dividing by 1,000,
1953
and ns to ms by dividing by 1,000,000. */
1954
block_time = ((retry_interval
1955
- ((intmax_t)waited_time.tv_sec * 1000))
1956
- ((intmax_t)waited_time.tv_nsec / 1000000));
1957
1958
if(debug){
1959
fprintf_plus(stderr, "Blocking for %" PRIdMAX " ms\n",
1960
block_time);
1961
}
1962
1963
if(block_time <= 0){
1964
ret = start_mandos_communication(mc->current_server->ip,
1965
mc->current_server->port,
1966
mc->current_server->if_index,
1967
mc->current_server->af, mc);
1968
if(ret == 0){
1969
avahi_simple_poll_quit(s);
1970
return 0;
1971
}
1972
ret = clock_gettime(CLOCK_MONOTONIC,
1973
&mc->current_server->last_seen);
1974
if(ret == -1){
1975
perror_plus("clock_gettime");
1976
return -1;
1977
}
1978
mc->current_server = mc->current_server->next;
1979
block_time = 0; /* Call avahi to find new Mandos
1980
servers, but don't block */
1981
}
1982
1983
ret = avahi_simple_poll_iterate(s, (int)block_time);
1984
}
1985
if(ret != 0){
1986
if(ret > 0 or errno != EINTR){
1987
return (ret != 1) ? ret : 0;
1988
}
1989
}
1990
}
1991
}
1992
1993
__attribute__((nonnull))
1994
void run_network_hooks(const char *mode, const char *interface,
1995
const float delay){
1996
struct dirent **direntries = NULL;
1997
if(hookdir_fd == -1){
1998
hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH
1999
| O_CLOEXEC);
2000
if(hookdir_fd == -1){
2001
if(errno == ENOENT){
2002
if(debug){
2003
fprintf_plus(stderr, "Network hook directory \"%s\" not"
2004
" found\n", hookdir);
2005
}
2006
} else {
2007
perror_plus("open");
2008
}
2009
return;
2010
}
2011
}
2012
int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));
2013
if(devnull == -1){
2014
perror_plus("open(\"/dev/null\", O_RDONLY)");
2015
return;
2016
}
2017
int numhooks = scandirat(hookdir_fd, ".", &direntries,
2018
runnable_hook, alphasort);
2019
if(numhooks == -1){
2020
perror_plus("scandir");
2021
close(devnull);
2022
return;
2023
}
2024
struct dirent *direntry;
2025
int ret;
2026
for(int i = 0; i < numhooks; i++){
2027
direntry = direntries[i];
2028
if(debug){
2029
fprintf_plus(stderr, "Running network hook \"%s\"\n",
2030
direntry->d_name);
2031
}
2032
pid_t hook_pid = fork();
2033
if(hook_pid == 0){
2034
/* Child */
2035
/* Raise privileges */
2036
errno = raise_privileges_permanently();
2037
if(errno != 0){
2038
perror_plus("Failed to raise privileges");
2039
_exit(EX_NOPERM);
2040
}
2041
/* Set group */
2042
errno = 0;
2043
ret = setgid(0);
2044
if(ret == -1){
2045
perror_plus("setgid");
2046
_exit(EX_NOPERM);
2047
}
2048
/* Reset supplementary groups */
2049
errno = 0;
2050
ret = setgroups(0, NULL);
2051
if(ret == -1){
2052
perror_plus("setgroups");
2053
_exit(EX_NOPERM);
2054
}
2055
ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);
2056
if(ret == -1){
2057
perror_plus("setenv");
2058
_exit(EX_OSERR);
2059
}
2060
ret = setenv("DEVICE", interface, 1);
2061
if(ret == -1){
2062
perror_plus("setenv");
2063
_exit(EX_OSERR);
2064
}
2065
ret = setenv("VERBOSITY", debug ? "1" : "0", 1);
2066
if(ret == -1){
2067
perror_plus("setenv");
2068
_exit(EX_OSERR);
2069
}
2070
ret = setenv("MODE", mode, 1);
2071
if(ret == -1){
2072
perror_plus("setenv");
2073
_exit(EX_OSERR);
2074
}
2075
char *delaystring;
2076
ret = asprintf(&delaystring, "%f", (double)delay);
2077
if(ret == -1){
2078
perror_plus("asprintf");
2079
_exit(EX_OSERR);
2080
}
2081
ret = setenv("DELAY", delaystring, 1);
2082
if(ret == -1){
2083
free(delaystring);
2084
perror_plus("setenv");
2085
_exit(EX_OSERR);
2086
}
2087
free(delaystring);
2088
if(connect_to != NULL){
2089
ret = setenv("CONNECT", connect_to, 1);
2090
if(ret == -1){
2091
perror_plus("setenv");
2092
_exit(EX_OSERR);
2093
}
2094
}
2095
int hook_fd = (int)TEMP_FAILURE_RETRY(openat(hookdir_fd,
2096
direntry->d_name,
2097
O_RDONLY));
2098
if(hook_fd == -1){
2099
perror_plus("openat");
2100
_exit(EXIT_FAILURE);
2101
}
2102
if(close(hookdir_fd) == -1){
2103
perror_plus("close");
2104
_exit(EXIT_FAILURE);
2105
}
2106
ret = dup2(devnull, STDIN_FILENO);
2107
if(ret == -1){
2108
perror_plus("dup2(devnull, STDIN_FILENO)");
2109
_exit(EX_OSERR);
2110
}
2111
ret = close(devnull);
2112
if(ret == -1){
2113
perror_plus("close");
2114
_exit(EX_OSERR);
2115
}
2116
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
2117
if(ret == -1){
2118
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
2119
_exit(EX_OSERR);
2120
}
2121
if(fexecve(hook_fd, (char *const []){ direntry->d_name, NULL },
2122
environ) == -1){
2123
perror_plus("fexecve");
2124
_exit(EXIT_FAILURE);
2125
}
2126
} else {
2127
if(hook_pid == -1){
2128
perror_plus("fork");
2129
free(direntry);
2130
continue;
2131
}
2132
int status;
2133
if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){
2134
perror_plus("waitpid");
2135
free(direntry);
2136
continue;
2137
}
2138
if(WIFEXITED(status)){
2139
if(WEXITSTATUS(status) != 0){
2140
fprintf_plus(stderr, "Warning: network hook \"%s\" exited"
2141
" with status %d\n", direntry->d_name,
2142
WEXITSTATUS(status));
2143
free(direntry);
2144
continue;
2145
}
2146
} else if(WIFSIGNALED(status)){
2147
fprintf_plus(stderr, "Warning: network hook \"%s\" died by"
2148
" signal %d\n", direntry->d_name,
2149
WTERMSIG(status));
2150
free(direntry);
2151
continue;
2152
} else {
2153
fprintf_plus(stderr, "Warning: network hook \"%s\""
2154
" crashed\n", direntry->d_name);
2155
free(direntry);
2156
continue;
2157
}
2158
}
2159
if(debug){
2160
fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",
2161
direntry->d_name);
2162
}
2163
free(direntry);
2164
}
2165
free(direntries);
2166
if(close(hookdir_fd) == -1){
2167
perror_plus("close");
2168
} else {
2169
hookdir_fd = -1;
2170
}
2171
close(devnull);
2172
}
2173
2174
__attribute__((nonnull, warn_unused_result))
2175
int bring_up_interface(const char *const interface,
2176
const float delay){
2177
int old_errno = errno;
2178
int ret;
2179
struct ifreq network;
2180
unsigned int if_index = if_nametoindex(interface);
2181
if(if_index == 0){
2182
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
2183
errno = old_errno;
2184
return ENXIO;
2185
}
2186
2187
if(quit_now){
2188
errno = old_errno;
2189
return EINTR;
2190
}
2191
2192
if(not interface_is_up(interface)){
2193
int ret_errno = 0;
2194
int ioctl_errno = 0;
2195
if(not get_flags(interface, &network)){
2196
ret_errno = errno;
2197
fprintf_plus(stderr, "Failed to get flags for interface "
2198
"\"%s\"\n", interface);
2199
errno = old_errno;
2200
return ret_errno;
2201
}
2202
network.ifr_flags |= IFF_UP; /* set flag */
2203
2204
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
2205
if(sd == -1){
2206
ret_errno = errno;
2207
perror_plus("socket");
2208
errno = old_errno;
2209
return ret_errno;
2210
}
2211
2212
if(quit_now){
2213
ret = close(sd);
2214
if(ret == -1){
2215
perror_plus("close");
2216
}
2217
errno = old_errno;
2218
return EINTR;
2219
}
2220
2221
if(debug){
2222
fprintf_plus(stderr, "Bringing up interface \"%s\"\n",
2223
interface);
2224
}
2225
2226
/* Raise privileges */
2227
ret_errno = raise_privileges();
2228
if(ret_errno != 0){
2229
errno = ret_errno;
2230
perror_plus("Failed to raise privileges");
2231
}
2232
2233
#ifdef __linux__
2234
int ret_linux;
2235
bool restore_loglevel = false;
2236
if(ret_errno == 0){
2237
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
2238
messages about the network interface to mess up the prompt */
2239
ret_linux = klogctl(8, NULL, 5);
2240
if(ret_linux == -1){
2241
perror_plus("klogctl");
2242
} else {
2243
restore_loglevel = true;
2244
}
2245
}
2246
#endif /* __linux__ */
2247
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
2248
ioctl_errno = errno;
2249
#ifdef __linux__
2250
if(restore_loglevel){
2251
ret_linux = klogctl(7, NULL, 0);
2252
if(ret_linux == -1){
2253
perror_plus("klogctl");
2254
}
2255
}
2256
#endif /* __linux__ */
2257
2258
/* If raise_privileges() succeeded above */
2259
if(ret_errno == 0){
2260
/* Lower privileges */
2261
ret_errno = lower_privileges();
2262
if(ret_errno != 0){
2263
errno = ret_errno;
2264
perror_plus("Failed to lower privileges");
2265
}
2266
}
2267
2268
/* Close the socket */
2269
ret = close(sd);
2270
if(ret == -1){
2271
perror_plus("close");
2272
}
2273
2274
if(ret_setflags == -1){
2275
errno = ioctl_errno;
2276
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
2277
errno = old_errno;
2278
return ioctl_errno;
2279
}
2280
} else if(debug){
2281
fprintf_plus(stderr, "Interface \"%s\" is already up; good\n",
2282
interface);
2283
}
2284
2285
/* Sleep checking until interface is running.
2286
Check every 0.25s, up to total time of delay */
2287
for(int i = 0; i < delay * 4; i++){
2288
if(interface_is_running(interface)){
2289
break;
2290
}
2291
struct timespec sleeptime = { .tv_nsec = 250000000 };
2292
ret = nanosleep(&sleeptime, NULL);
2293
if(ret == -1 and errno != EINTR){
2294
perror_plus("nanosleep");
2295
}
2296
}
2297
2298
errno = old_errno;
2299
return 0;
2300
}
2301
2302
__attribute__((nonnull, warn_unused_result))
2303
int take_down_interface(const char *const interface){
2304
int old_errno = errno;
2305
struct ifreq network;
2306
unsigned int if_index = if_nametoindex(interface);
2307
if(if_index == 0){
2308
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
2309
errno = old_errno;
2310
return ENXIO;
2311
}
2312
if(interface_is_up(interface)){
2313
int ret_errno = 0;
2314
int ioctl_errno = 0;
2315
if(not get_flags(interface, &network) and debug){
2316
ret_errno = errno;
2317
fprintf_plus(stderr, "Failed to get flags for interface "
2318
"\"%s\"\n", interface);
2319
errno = old_errno;
2320
return ret_errno;
2321
}
2322
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
2323
2324
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
2325
if(sd == -1){
2326
ret_errno = errno;
2327
perror_plus("socket");
2328
errno = old_errno;
2329
return ret_errno;
2330
}
2331
2332
if(debug){
2333
fprintf_plus(stderr, "Taking down interface \"%s\"\n",
2334
interface);
2335
}
2336
2337
/* Raise privileges */
2338
ret_errno = raise_privileges();
2339
if(ret_errno != 0){
2340
errno = ret_errno;
2341
perror_plus("Failed to raise privileges");
2342
}
2343
2344
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
2345
ioctl_errno = errno;
2346
2347
/* If raise_privileges() succeeded above */
2348
if(ret_errno == 0){
2349
/* Lower privileges */
2350
ret_errno = lower_privileges();
2351
if(ret_errno != 0){
2352
errno = ret_errno;
2353
perror_plus("Failed to lower privileges");
2354
}
2355
}
2356
2357
/* Close the socket */
2358
int ret = close(sd);
2359
if(ret == -1){
2360
perror_plus("close");
2361
}
2362
2363
if(ret_setflags == -1){
2364
errno = ioctl_errno;
2365
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
2366
errno = old_errno;
2367
return ioctl_errno;
2368
}
2369
} else if(debug){
2370
fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",
2371
interface);
2372
}
2373
2374
errno = old_errno;
2375
return 0;
2376
}
2377
2378
int main(int argc, char *argv[]){
2379
mandos_context mc = { .server = NULL, .dh_bits = 0,
2380
.priority = "SECURE256:!CTYPE-X.509"
2381
":+CTYPE-OPENPGP:!RSA:+SIGN-DSA-SHA256",
2382
.current_server = NULL, .interfaces = NULL,
2383
.interfaces_size = 0 };
2384
AvahiSServiceBrowser *sb = NULL;
2385
error_t ret_errno;
2386
int ret;
2387
intmax_t tmpmax;
2388
char *tmp;
2389
int exitcode = EXIT_SUCCESS;
2390
char *interfaces_to_take_down = NULL;
2391
size_t interfaces_to_take_down_size = 0;
2392
char run_tempdir[] = "/run/tmp/mandosXXXXXX";
2393
char old_tempdir[] = "/tmp/mandosXXXXXX";
2394
char *tempdir = NULL;
2395
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
2396
const char *seckey = PATHDIR "/" SECKEY;
2397
const char *pubkey = PATHDIR "/" PUBKEY;
2398
const char *dh_params_file = NULL;
2399
char *interfaces_hooks = NULL;
2400
2401
bool gnutls_initialized = false;
2402
bool gpgme_initialized = false;
2403
float delay = 2.5f;
2404
double retry_interval = 10; /* 10s between trying a server and
2405
retrying the same server again */
2406
2407
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
2408
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
2409
2410
uid = getuid();
2411
gid = getgid();
2412
2413
/* Lower any group privileges we might have, just to be safe */
2414
errno = 0;
2415
ret = setgid(gid);
2416
if(ret == -1){
2417
perror_plus("setgid");
2418
}
2419
2420
/* Lower user privileges (temporarily) */
2421
errno = 0;
2422
ret = seteuid(uid);
2423
if(ret == -1){
2424
perror_plus("seteuid");
2425
}
2426
2427
if(quit_now){
2428
goto end;
2429
}
2430
2431
{
2432
struct argp_option options[] = {
2433
{ .name = "debug", .key = 128,
2434
.doc = "Debug mode", .group = 3 },
2435
{ .name = "connect", .key = 'c',
2436
.arg = "ADDRESS:PORT",
2437
.doc = "Connect directly to a specific Mandos server",
2438
.group = 1 },
2439
{ .name = "interface", .key = 'i',
2440
.arg = "NAME",
2441
.doc = "Network interface that will be used to search for"
2442
" Mandos servers",
2443
.group = 1 },
2444
{ .name = "seckey", .key = 's',
2445
.arg = "FILE",
2446
.doc = "OpenPGP secret key file base name",
2447
.group = 1 },
2448
{ .name = "pubkey", .key = 'p',
2449
.arg = "FILE",
2450
.doc = "OpenPGP public key file base name",
2451
.group = 2 },
2452
{ .name = "dh-bits", .key = 129,
2453
.arg = "BITS",
2454
.doc = "Bit length of the prime number used in the"
2455
" Diffie-Hellman key exchange",
2456
.group = 2 },
2457
{ .name = "dh-params", .key = 134,
2458
.arg = "FILE",
2459
.doc = "PEM-encoded PKCS#3 file with pre-generated parameters"
2460
" for the Diffie-Hellman key exchange",
2461
.group = 2 },
2462
{ .name = "priority", .key = 130,
2463
.arg = "STRING",
2464
.doc = "GnuTLS priority string for the TLS handshake",
2465
.group = 1 },
2466
{ .name = "delay", .key = 131,
2467
.arg = "SECONDS",
2468
.doc = "Maximum delay to wait for interface startup",
2469
.group = 2 },
2470
{ .name = "retry", .key = 132,
2471
.arg = "SECONDS",
2472
.doc = "Retry interval used when denied by the Mandos server",
2473
.group = 2 },
2474
{ .name = "network-hook-dir", .key = 133,
2475
.arg = "DIR",
2476
.doc = "Directory where network hooks are located",
2477
.group = 2 },
2478
/*
2479
* These reproduce what we would get without ARGP_NO_HELP
2480
*/
2481
{ .name = "help", .key = '?',
2482
.doc = "Give this help list", .group = -1 },
2483
{ .name = "usage", .key = -3,
2484
.doc = "Give a short usage message", .group = -1 },
2485
{ .name = "version", .key = 'V',
2486
.doc = "Print program version", .group = -1 },
2487
{ .name = NULL }
2488
};
2489
2490
error_t parse_opt(int key, char *arg,
2491
struct argp_state *state){
2492
errno = 0;
2493
switch(key){
2494
case 128: /* --debug */
2495
debug = true;
2496
break;
2497
case 'c': /* --connect */
2498
connect_to = arg;
2499
break;
2500
case 'i': /* --interface */
2501
ret_errno = argz_add_sep(&mc.interfaces, &mc.interfaces_size,
2502
arg, (int)',');
2503
if(ret_errno != 0){
2504
argp_error(state, "%s", strerror(ret_errno));
2505
}
2506
break;
2507
case 's': /* --seckey */
2508
seckey = arg;
2509
break;
2510
case 'p': /* --pubkey */
2511
pubkey = arg;
2512
break;
2513
case 129: /* --dh-bits */
2514
errno = 0;
2515
tmpmax = strtoimax(arg, &tmp, 10);
2516
if(errno != 0 or tmp == arg or *tmp != '\0'
2517
or tmpmax != (typeof(mc.dh_bits))tmpmax){
2518
argp_error(state, "Bad number of DH bits");
2519
}
2520
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
2521
break;
2522
case 134: /* --dh-params */
2523
dh_params_file = arg;
2524
break;
2525
case 130: /* --priority */
2526
mc.priority = arg;
2527
break;
2528
case 131: /* --delay */
2529
errno = 0;
2530
delay = strtof(arg, &tmp);
2531
if(errno != 0 or tmp == arg or *tmp != '\0'){
2532
argp_error(state, "Bad delay");
2533
}
2534
case 132: /* --retry */
2535
errno = 0;
2536
retry_interval = strtod(arg, &tmp);
2537
if(errno != 0 or tmp == arg or *tmp != '\0'
2538
or (retry_interval * 1000) > INT_MAX
2539
or retry_interval < 0){
2540
argp_error(state, "Bad retry interval");
2541
}
2542
break;
2543
case 133: /* --network-hook-dir */
2544
hookdir = arg;
2545
break;
2546
/*
2547
* These reproduce what we would get without ARGP_NO_HELP
2548
*/
2549
case '?': /* --help */
2550
argp_state_help(state, state->out_stream,
2551
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
2552
& ~(unsigned int)ARGP_HELP_EXIT_OK);
2553
case -3: /* --usage */
2554
argp_state_help(state, state->out_stream,
2555
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
2556
case 'V': /* --version */
2557
fprintf_plus(state->out_stream, "%s\n", argp_program_version);
2558
exit(argp_err_exit_status);
2559
break;
2560
default:
2561
return ARGP_ERR_UNKNOWN;
2562
}
2563
return errno;
2564
}
2565
2566
struct argp argp = { .options = options, .parser = parse_opt,
2567
.args_doc = "",
2568
.doc = "Mandos client -- Get and decrypt"
2569
" passwords from a Mandos server" };
2570
ret_errno = argp_parse(&argp, argc, argv,
2571
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
2572
switch(ret_errno){
2573
case 0:
2574
break;
2575
case ENOMEM:
2576
default:
2577
errno = ret_errno;
2578
perror_plus("argp_parse");
2579
exitcode = EX_OSERR;
2580
goto end;
2581
case EINVAL:
2582
exitcode = EX_USAGE;
2583
goto end;
2584
}
2585
}
2586
2587
{
2588
/* Work around Debian bug #633582:
2589
<https://bugs.debian.org/633582> */
2590
2591
/* Re-raise privileges */
2592
ret = raise_privileges();
2593
if(ret != 0){
2594
errno = ret;
2595
perror_plus("Failed to raise privileges");
2596
} else {
2597
struct stat st;
2598
2599
if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){
2600
int seckey_fd = open(seckey, O_RDONLY);
2601
if(seckey_fd == -1){
2602
perror_plus("open");
2603
} else {
2604
ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));
2605
if(ret == -1){
2606
perror_plus("fstat");
2607
} else {
2608
if(S_ISREG(st.st_mode)
2609
and st.st_uid == 0 and st.st_gid == 0){
2610
ret = fchown(seckey_fd, uid, gid);
2611
if(ret == -1){
2612
perror_plus("fchown");
2613
}
2614
}
2615
}
2616
close(seckey_fd);
2617
}
2618
}
2619
2620
if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){
2621
int pubkey_fd = open(pubkey, O_RDONLY);
2622
if(pubkey_fd == -1){
2623
perror_plus("open");
2624
} else {
2625
ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));
2626
if(ret == -1){
2627
perror_plus("fstat");
2628
} else {
2629
if(S_ISREG(st.st_mode)
2630
and st.st_uid == 0 and st.st_gid == 0){
2631
ret = fchown(pubkey_fd, uid, gid);
2632
if(ret == -1){
2633
perror_plus("fchown");
2634
}
2635
}
2636
}
2637
close(pubkey_fd);
2638
}
2639
}
2640
2641
if(dh_params_file != NULL
2642
and strcmp(dh_params_file, PATHDIR "/dhparams.pem" ) == 0){
2643
int dhparams_fd = open(dh_params_file, O_RDONLY);
2644
if(dhparams_fd == -1){
2645
perror_plus("open");
2646
} else {
2647
ret = (int)TEMP_FAILURE_RETRY(fstat(dhparams_fd, &st));
2648
if(ret == -1){
2649
perror_plus("fstat");
2650
} else {
2651
if(S_ISREG(st.st_mode)
2652
and st.st_uid == 0 and st.st_gid == 0){
2653
ret = fchown(dhparams_fd, uid, gid);
2654
if(ret == -1){
2655
perror_plus("fchown");
2656
}
2657
}
2658
}
2659
close(dhparams_fd);
2660
}
2661
}
2662
2663
/* Lower privileges */
2664
ret = lower_privileges();
2665
if(ret != 0){
2666
errno = ret;
2667
perror_plus("Failed to lower privileges");
2668
}
2669
}
2670
}
2671
2672
/* Remove invalid interface names (except "none") */
2673
{
2674
char *interface = NULL;
2675
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2676
interface))){
2677
if(strcmp(interface, "none") != 0
2678
and if_nametoindex(interface) == 0){
2679
if(interface[0] != '\0'){
2680
fprintf_plus(stderr, "Not using nonexisting interface"
2681
" \"%s\"\n", interface);
2682
}
2683
argz_delete(&mc.interfaces, &mc.interfaces_size, interface);
2684
interface = NULL;
2685
}
2686
}
2687
}
2688
2689
/* Run network hooks */
2690
{
2691
if(mc.interfaces != NULL){
2692
interfaces_hooks = malloc(mc.interfaces_size);
2693
if(interfaces_hooks == NULL){
2694
perror_plus("malloc");
2695
goto end;
2696
}
2697
memcpy(interfaces_hooks, mc.interfaces, mc.interfaces_size);
2698
argz_stringify(interfaces_hooks, mc.interfaces_size, (int)',');
2699
}
2700
run_network_hooks("start", interfaces_hooks != NULL ?
2701
interfaces_hooks : "", delay);
2702
}
2703
2704
if(not debug){
2705
avahi_set_log_function(empty_log);
2706
}
2707
2708
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
2709
from the signal handler */
2710
/* Initialize the pseudo-RNG for Avahi */
2711
srand((unsigned int) time(NULL));
2712
simple_poll = avahi_simple_poll_new();
2713
if(simple_poll == NULL){
2714
fprintf_plus(stderr,
2715
"Avahi: Failed to create simple poll object.\n");
2716
exitcode = EX_UNAVAILABLE;
2717
goto end;
2718
}
2719
2720
sigemptyset(&sigterm_action.sa_mask);
2721
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
2722
if(ret == -1){
2723
perror_plus("sigaddset");
2724
exitcode = EX_OSERR;
2725
goto end;
2726
}
2727
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
2728
if(ret == -1){
2729
perror_plus("sigaddset");
2730
exitcode = EX_OSERR;
2731
goto end;
2732
}
2733
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
2734
if(ret == -1){
2735
perror_plus("sigaddset");
2736
exitcode = EX_OSERR;
2737
goto end;
2738
}
2739
/* Need to check if the handler is SIG_IGN before handling:
2740
| [[info:libc:Initial Signal Actions]] |
2741
| [[info:libc:Basic Signal Handling]] |
2742
*/
2743
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
2744
if(ret == -1){
2745
perror_plus("sigaction");
2746
return EX_OSERR;
2747
}
2748
if(old_sigterm_action.sa_handler != SIG_IGN){
2749
ret = sigaction(SIGINT, &sigterm_action, NULL);
2750
if(ret == -1){
2751
perror_plus("sigaction");
2752
exitcode = EX_OSERR;
2753
goto end;
2754
}
2755
}
2756
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
2757
if(ret == -1){
2758
perror_plus("sigaction");
2759
return EX_OSERR;
2760
}
2761
if(old_sigterm_action.sa_handler != SIG_IGN){
2762
ret = sigaction(SIGHUP, &sigterm_action, NULL);
2763
if(ret == -1){
2764
perror_plus("sigaction");
2765
exitcode = EX_OSERR;
2766
goto end;
2767
}
2768
}
2769
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
2770
if(ret == -1){
2771
perror_plus("sigaction");
2772
return EX_OSERR;
2773
}
2774
if(old_sigterm_action.sa_handler != SIG_IGN){
2775
ret = sigaction(SIGTERM, &sigterm_action, NULL);
2776
if(ret == -1){
2777
perror_plus("sigaction");
2778
exitcode = EX_OSERR;
2779
goto end;
2780
}
2781
}
2782
2783
/* If no interfaces were specified, make a list */
2784
if(mc.interfaces == NULL){
2785
struct dirent **direntries = NULL;
2786
/* Look for any good interfaces */
2787
ret = scandir(sys_class_net, &direntries, good_interface,
2788
alphasort);
2789
if(ret >= 1){
2790
/* Add all found interfaces to interfaces list */
2791
for(int i = 0; i < ret; ++i){
2792
ret_errno = argz_add(&mc.interfaces, &mc.interfaces_size,
2793
direntries[i]->d_name);
2794
if(ret_errno != 0){
2795
errno = ret_errno;
2796
perror_plus("argz_add");
2797
free(direntries[i]);
2798
continue;
2799
}
2800
if(debug){
2801
fprintf_plus(stderr, "Will use interface \"%s\"\n",
2802
direntries[i]->d_name);
2803
}
2804
free(direntries[i]);
2805
}
2806
free(direntries);
2807
} else {
2808
if(ret == 0){
2809
free(direntries);
2810
}
2811
fprintf_plus(stderr, "Could not find a network interface\n");
2812
exitcode = EXIT_FAILURE;
2813
goto end;
2814
}
2815
}
2816
2817
/* Bring up interfaces which are down, and remove any "none"s */
2818
{
2819
char *interface = NULL;
2820
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2821
interface))){
2822
/* If interface name is "none", stop bringing up interfaces.
2823
Also remove all instances of "none" from the list */
2824
if(strcmp(interface, "none") == 0){
2825
argz_delete(&mc.interfaces, &mc.interfaces_size,
2826
interface);
2827
interface = NULL;
2828
while((interface = argz_next(mc.interfaces,
2829
mc.interfaces_size, interface))){
2830
if(strcmp(interface, "none") == 0){
2831
argz_delete(&mc.interfaces, &mc.interfaces_size,
2832
interface);
2833
interface = NULL;
2834
}
2835
}
2836
break;
2837
}
2838
bool interface_was_up = interface_is_up(interface);
2839
errno = bring_up_interface(interface, delay);
2840
if(not interface_was_up){
2841
if(errno != 0){
2842
fprintf_plus(stderr, "Failed to bring up interface \"%s\":"
2843
" %s\n", interface, strerror(errno));
2844
} else {
2845
errno = argz_add(&interfaces_to_take_down,
2846
&interfaces_to_take_down_size,
2847
interface);
2848
if(errno != 0){
2849
perror_plus("argz_add");
2850
}
2851
}
2852
}
2853
}
2854
if(debug and (interfaces_to_take_down == NULL)){
2855
fprintf_plus(stderr, "No interfaces were brought up\n");
2856
}
2857
}
2858
2859
/* If we only got one interface, explicitly use only that one */
2860
if(argz_count(mc.interfaces, mc.interfaces_size) == 1){
2861
if(debug){
2862
fprintf_plus(stderr, "Using only interface \"%s\"\n",
2863
mc.interfaces);
2864
}
2865
if_index = (AvahiIfIndex)if_nametoindex(mc.interfaces);
2866
}
2867
2868
if(quit_now){
2869
goto end;
2870
}
2871
2872
ret = init_gnutls_global(pubkey, seckey, dh_params_file, &mc);
2873
if(ret == -1){
2874
fprintf_plus(stderr, "init_gnutls_global failed\n");
2875
exitcode = EX_UNAVAILABLE;
2876
goto end;
2877
} else {
2878
gnutls_initialized = true;
2879
}
2880
2881
if(quit_now){
2882
goto end;
2883
}
2884
2885
/* Try /run/tmp before /tmp */
2886
tempdir = mkdtemp(run_tempdir);
2887
if(tempdir == NULL and errno == ENOENT){
2888
if(debug){
2889
fprintf_plus(stderr, "Tempdir %s did not work, trying %s\n",
2890
run_tempdir, old_tempdir);
2891
}
2892
tempdir = mkdtemp(old_tempdir);
2893
}
2894
if(tempdir == NULL){
2895
perror_plus("mkdtemp");
2896
goto end;
2897
}
2898
2899
if(quit_now){
2900
goto end;
2901
}
2902
2903
if(not init_gpgme(pubkey, seckey, tempdir, &mc)){
2904
fprintf_plus(stderr, "init_gpgme failed\n");
2905
exitcode = EX_UNAVAILABLE;
2906
goto end;
2907
} else {
2908
gpgme_initialized = true;
2909
}
2910
2911
if(quit_now){
2912
goto end;
2913
}
2914
2915
if(connect_to != NULL){
2916
/* Connect directly, do not use Zeroconf */
2917
/* (Mainly meant for debugging) */
2918
char *address = strrchr(connect_to, ':');
2919
2920
if(address == NULL){
2921
fprintf_plus(stderr, "No colon in address\n");
2922
exitcode = EX_USAGE;
2923
goto end;
2924
}
2925
2926
if(quit_now){
2927
goto end;
2928
}
2929
2930
in_port_t port;
2931
errno = 0;
2932
tmpmax = strtoimax(address+1, &tmp, 10);
2933
if(errno != 0 or tmp == address+1 or *tmp != '\0'
2934
or tmpmax != (in_port_t)tmpmax){
2935
fprintf_plus(stderr, "Bad port number\n");
2936
exitcode = EX_USAGE;
2937
goto end;
2938
}
2939
2940
if(quit_now){
2941
goto end;
2942
}
2943
2944
port = (in_port_t)tmpmax;
2945
*address = '\0';
2946
/* Colon in address indicates IPv6 */
2947
int af;
2948
if(strchr(connect_to, ':') != NULL){
2949
af = AF_INET6;
2950
/* Accept [] around IPv6 address - see RFC 5952 */
2951
if(connect_to[0] == '[' and address[-1] == ']')
2952
{
2953
connect_to++;
2954
address[-1] = '\0';
2955
}
2956
} else {
2957
af = AF_INET;
2958
}
2959
address = connect_to;
2960
2961
if(quit_now){
2962
goto end;
2963
}
2964
2965
while(not quit_now){
2966
ret = start_mandos_communication(address, port, if_index, af,
2967
&mc);
2968
if(quit_now or ret == 0){
2969
break;
2970
}
2971
if(debug){
2972
fprintf_plus(stderr, "Retrying in %d seconds\n",
2973
(int)retry_interval);
2974
}
2975
sleep((unsigned int)retry_interval);
2976
}
2977
2978
if(not quit_now){
2979
exitcode = EXIT_SUCCESS;
2980
}
2981
2982
goto end;
2983
}
2984
2985
if(quit_now){
2986
goto end;
2987
}
2988
2989
{
2990
AvahiServerConfig config;
2991
/* Do not publish any local Zeroconf records */
2992
avahi_server_config_init(&config);
2993
config.publish_hinfo = 0;
2994
config.publish_addresses = 0;
2995
config.publish_workstation = 0;
2996
config.publish_domain = 0;
2997
2998
/* Allocate a new server */
2999
mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),
3000
&config, NULL, NULL, &ret);
3001
3002
/* Free the Avahi configuration data */
3003
avahi_server_config_free(&config);
3004
}
3005
3006
/* Check if creating the Avahi server object succeeded */
3007
if(mc.server == NULL){
3008
fprintf_plus(stderr, "Failed to create Avahi server: %s\n",
3009
avahi_strerror(ret));
3010
exitcode = EX_UNAVAILABLE;
3011
goto end;
3012
}
3013
3014
if(quit_now){
3015
goto end;
3016
}
3017
3018
/* Create the Avahi service browser */
3019
sb = avahi_s_service_browser_new(mc.server, if_index,
3020
AVAHI_PROTO_UNSPEC, "_mandos._tcp",
3021
NULL, 0, browse_callback,
3022
(void *)&mc);
3023
if(sb == NULL){
3024
fprintf_plus(stderr, "Failed to create service browser: %s\n",
3025
avahi_strerror(avahi_server_errno(mc.server)));
3026
exitcode = EX_UNAVAILABLE;
3027
goto end;
3028
}
3029
3030
if(quit_now){
3031
goto end;
3032
}
3033
3034
/* Run the main loop */
3035
3036
if(debug){
3037
fprintf_plus(stderr, "Starting Avahi loop search\n");
3038
}
3039
3040
ret = avahi_loop_with_timeout(simple_poll,
3041
(int)(retry_interval * 1000), &mc);
3042
if(debug){
3043
fprintf_plus(stderr, "avahi_loop_with_timeout exited %s\n",
3044
(ret == 0) ? "successfully" : "with error");
3045
}
3046
3047
end:
3048
3049
if(debug){
3050
if(signal_received){
3051
fprintf_plus(stderr, "%s exiting due to signal %d: %s\n",
3052
argv[0], signal_received,
3053
strsignal(signal_received));
3054
} else {
3055
fprintf_plus(stderr, "%s exiting\n", argv[0]);
3056
}
3057
}
3058
3059
/* Cleanup things */
3060
free(mc.interfaces);
3061
3062
if(sb != NULL)
3063
avahi_s_service_browser_free(sb);
3064
3065
if(mc.server != NULL)
3066
avahi_server_free(mc.server);
3067
3068
if(simple_poll != NULL)
3069
avahi_simple_poll_free(simple_poll);
3070
3071
if(gnutls_initialized){
3072
gnutls_certificate_free_credentials(mc.cred);
3073
gnutls_dh_params_deinit(mc.dh_params);
3074
}
3075
3076
if(gpgme_initialized){
3077
gpgme_release(mc.ctx);
3078
}
3079
3080
/* Cleans up the circular linked list of Mandos servers the client
3081
has seen */
3082
if(mc.current_server != NULL){
3083
mc.current_server->prev->next = NULL;
3084
while(mc.current_server != NULL){
3085
server *next = mc.current_server->next;
3086
#ifdef __GNUC__
3087
#pragma GCC diagnostic push
3088
#pragma GCC diagnostic ignored "-Wcast-qual"
3089
#endif
3090
free((char *)(mc.current_server->ip));
3091
#ifdef __GNUC__
3092
#pragma GCC diagnostic pop
3093
#endif
3094
free(mc.current_server);
3095
mc.current_server = next;
3096
}
3097
}
3098
3099
/* Re-raise privileges */
3100
{
3101
ret = raise_privileges();
3102
if(ret != 0){
3103
errno = ret;
3104
perror_plus("Failed to raise privileges");
3105
} else {
3106
3107
/* Run network hooks */
3108
run_network_hooks("stop", interfaces_hooks != NULL ?
3109
interfaces_hooks : "", delay);
3110
3111
/* Take down the network interfaces which were brought up */
3112
{
3113
char *interface = NULL;
3114
while((interface = argz_next(interfaces_to_take_down,
3115
interfaces_to_take_down_size,
3116
interface))){
3117
ret = take_down_interface(interface);
3118
if(ret != 0){
3119
errno = ret;
3120
perror_plus("Failed to take down interface");
3121
}
3122
}
3123
if(debug and (interfaces_to_take_down == NULL)){
3124
fprintf_plus(stderr, "No interfaces needed to be taken"
3125
" down\n");
3126
}
3127
}
3128
}
3129
3130
ret = lower_privileges_permanently();
3131
if(ret != 0){
3132
errno = ret;
3133
perror_plus("Failed to lower privileges permanently");
3134
}
3135
}
3136
3137
free(interfaces_to_take_down);
3138
free(interfaces_hooks);
3139
3140
void clean_dir_at(int base, const char * const dirname,
3141
uintmax_t level){
3142
struct dirent **direntries = NULL;
3143
int dret;
3144
int dir_fd = (int)TEMP_FAILURE_RETRY(openat(base, dirname,
3145
O_RDONLY
3146
| O_NOFOLLOW
3147
| O_DIRECTORY
3148
| O_PATH));
3149
if(dir_fd == -1){
3150
perror_plus("open");
3151
return;
3152
}
3153
int numentries = scandirat(dir_fd, ".", &direntries,
3154
notdotentries, alphasort);
3155
if(numentries >= 0){
3156
for(int i = 0; i < numentries; i++){
3157
if(debug){
3158
fprintf_plus(stderr, "Unlinking \"%s/%s\"\n",
3159
dirname, direntries[i]->d_name);
3160
}
3161
dret = unlinkat(dir_fd, direntries[i]->d_name, 0);
3162
if(dret == -1){
3163
if(errno == EISDIR){
3164
dret = unlinkat(dir_fd, direntries[i]->d_name,
3165
AT_REMOVEDIR);
3166
}
3167
if((dret == -1) and (errno == ENOTEMPTY)
3168
and (strcmp(direntries[i]->d_name, "private-keys-v1.d")
3169
== 0) and (level == 0)){
3170
/* Recurse only in this special case */
3171
clean_dir_at(dir_fd, direntries[i]->d_name, level+1);
3172
dret = 0;
3173
}
3174
if((dret == -1) and (errno != ENOENT)){
3175
fprintf_plus(stderr, "unlink(\"%s/%s\"): %s\n", dirname,
3176
direntries[i]->d_name, strerror(errno));
3177
}
3178
}
3179
free(direntries[i]);
3180
}
3181
3182
/* need to clean even if 0 because man page doesn't specify */
3183
free(direntries);
3184
dret = unlinkat(base, dirname, AT_REMOVEDIR);
3185
if(dret == -1 and errno != ENOENT){
3186
perror_plus("rmdir");
3187
}
3188
} else {
3189
perror_plus("scandirat");
3190
}
3191
close(dir_fd);
3192
}
3193
3194
/* Removes the GPGME temp directory and all files inside */
3195
if(tempdir != NULL){
3196
clean_dir_at(-1, tempdir, 0);
3197
}
3198
3199
if(quit_now){
3200
sigemptyset(&old_sigterm_action.sa_mask);
3201
old_sigterm_action.sa_handler = SIG_DFL;
3202
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
3203
&old_sigterm_action,
3204
NULL));
3205
if(ret == -1){
3206
perror_plus("sigaction");
3207
}
3208
do {
3209
ret = raise(signal_received);
3210
} while(ret != 0 and errno == EINTR);
3211
if(ret != 0){
3212
perror_plus("raise");
3213
abort();
3214
}
3215
TEMP_FAILURE_RETRY(pause());
3216
}
3217
3218
return exitcode;
3219
}
Loggerhead is a web-based interface for Breezy
Version: 2.0.2.dev0