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- Committer: Teddy Hogeborn
- Date: 2015-07-06 20:29:34 UTC
- mfrom: (738.1.6 route-external)
- Revision ID: teddy@recompile.se-20150706202934-09j06jm2fiw1bn80
Merge change to add local route when network is "unreachable".
- files added:
- .bzr-builddeb
- debian
- debian/po
- debian/source
- debian/upstream
- network-hooks.d
- plugin-helpers
- plugins.d
- files removed:
- bad-ca.pem
- 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 © 2008-2015 Teddy Hogeborn
13
* Copyright © 2008-2015 Björn Påhlsson
14
*
15
* This program is free software: you can redistribute it and/or
16
* modify it under the terms of the GNU General Public License as
17
* published by the Free Software Foundation, either version 3 of the
18
* License, or (at your option) any later version.
19
*
20
* This program is distributed in the hope that it will be useful, but
21
* WITHOUT ANY WARRANTY; without even the implied warranty of
22
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
23
* General Public License for more details.
24
*
25
* You should have received a copy of the GNU General Public License
26
* along with this program. If not, see
27
* <http://www.gnu.org/licenses/>.
28
*
29
* Contact the authors at <mandos@recompile.se>.
30
*/
31
32
/* Needed by GPGME, specifically gpgme_data_seek() */
33
#ifndef _LARGEFILE_SOURCE
34
#define _LARGEFILE_SOURCE
35
#endif /* not _LARGEFILE_SOURCE */
36
#ifndef _FILE_OFFSET_BITS
37
#define _FILE_OFFSET_BITS 64
38
#endif /* not _FILE_OFFSET_BITS */
39
40
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
41
42
#include <stdio.h> /* fprintf(), stderr, fwrite(),
43
stdout, ferror() */
44
#include <stdint.h> /* uint16_t, uint32_t, intptr_t */
45
#include <stddef.h> /* NULL, size_t, ssize_t */
46
#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),
47
strtof(), abort() */
48
#include <stdbool.h> /* bool, false, true */
49
#include <string.h> /* memset(), strcmp(), strlen(),
50
strerror(), asprintf(), strcpy() */
51
#include <sys/ioctl.h> /* ioctl */
52
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
53
sockaddr_in6, PF_INET6,
54
SOCK_STREAM, uid_t, gid_t, open(),
55
opendir(), DIR */
56
#include <sys/stat.h> /* open(), S_ISREG */
57
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
58
inet_pton(), connect(),
59
getnameinfo() */
60
#include <fcntl.h> /* open(), unlinkat() */
61
#include <dirent.h> /* opendir(), struct dirent, readdir()
62
*/
63
#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,
64
strtoimax() */
65
#include <errno.h> /* perror(), errno,
66
program_invocation_short_name */
67
#include <time.h> /* nanosleep(), time(), sleep() */
68
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
69
SIOCSIFFLAGS, if_indextoname(),
70
if_nametoindex(), IF_NAMESIZE */
71
#include <netinet/in.h> /* IN6_IS_ADDR_LINKLOCAL,
72
INET_ADDRSTRLEN, INET6_ADDRSTRLEN
73
*/
74
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
75
getuid(), getgid(), seteuid(),
76
setgid(), pause(), _exit(),
77
unlinkat() */
78
#include <arpa/inet.h> /* inet_pton(), htons() */
79
#include <iso646.h> /* not, or, and */
80
#include <argp.h> /* struct argp_option, error_t, struct
81
argp_state, struct argp,
82
argp_parse(), ARGP_KEY_ARG,
83
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
84
#include <signal.h> /* sigemptyset(), sigaddset(),
85
sigaction(), SIGTERM, sig_atomic_t,
86
raise() */
87
#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,
88
EX_NOHOST, EX_IOERR, EX_PROTOCOL */
89
#include <sys/wait.h> /* waitpid(), WIFEXITED(),
90
WEXITSTATUS(), WTERMSIG() */
91
#include <grp.h> /* setgroups() */
92
#include <argz.h> /* argz_add_sep(), argz_next(),
93
argz_delete(), argz_append(),
94
argz_stringify(), argz_add(),
95
argz_count() */
96
#include <netdb.h> /* getnameinfo(), NI_NUMERICHOST,
97
EAI_SYSTEM, gai_strerror() */
98
99
#ifdef __linux__
100
#include <sys/klog.h> /* klogctl() */
101
#endif /* __linux__ */
102
103
/* Avahi */
104
/* All Avahi types, constants and functions
105
Avahi*, avahi_*,
106
AVAHI_* */
107
#include <avahi-core/core.h>
108
#include <avahi-core/lookup.h>
109
#include <avahi-core/log.h>
110
#include <avahi-common/simple-watch.h>
111
#include <avahi-common/malloc.h>
112
#include <avahi-common/error.h>
113
114
/* GnuTLS */
115
#include <gnutls/gnutls.h> /* All GnuTLS types, constants and
116
functions:
117
gnutls_*
118
init_gnutls_session(),
119
GNUTLS_* */
120
#include <gnutls/openpgp.h>
121
/* gnutls_certificate_set_openpgp_key_file(),
122
GNUTLS_OPENPGP_FMT_BASE64 */
123
124
/* GPGME */
125
#include <gpgme.h> /* All GPGME types, constants and
126
functions:
127
gpgme_*
128
GPGME_PROTOCOL_OpenPGP,
129
GPG_ERR_NO_* */
130
131
#define BUFFER_SIZE 256
132
133
#define PATHDIR "/conf/conf.d/mandos"
134
#define SECKEY "seckey.txt"
135
#define PUBKEY "pubkey.txt"
136
#define HOOKDIR "/lib/mandos/network-hooks.d"
137
138
bool debug = false;
139
static const char mandos_protocol_version[] = "1";
140
const char *argp_program_version = "mandos-client " VERSION;
141
const char *argp_program_bug_address = "<mandos@recompile.se>";
142
static const char sys_class_net[] = "/sys/class/net";
143
char *connect_to = NULL;
144
const char *hookdir = HOOKDIR;
145
int hookdir_fd = -1;
146
uid_t uid = 65534;
147
gid_t gid = 65534;
148
149
/* Doubly linked list that need to be circularly linked when used */
150
typedef struct server{
151
const char *ip;
152
in_port_t port;
153
AvahiIfIndex if_index;
154
int af;
155
struct timespec last_seen;
156
struct server *next;
157
struct server *prev;
158
} server;
159
160
/* Used for passing in values through the Avahi callback functions */
161
typedef struct {
162
AvahiServer *server;
163
gnutls_certificate_credentials_t cred;
164
unsigned int dh_bits;
165
gnutls_dh_params_t dh_params;
166
const char *priority;
167
gpgme_ctx_t ctx;
168
server *current_server;
169
char *interfaces;
170
size_t interfaces_size;
171
} mandos_context;
172
173
/* global so signal handler can reach it*/
174
AvahiSimplePoll *simple_poll;
175
176
sig_atomic_t quit_now = 0;
177
int signal_received = 0;
178
179
/* Function to use when printing errors */
180
void perror_plus(const char *print_text){
181
int e = errno;
182
fprintf(stderr, "Mandos plugin %s: ",
183
program_invocation_short_name);
184
errno = e;
185
perror(print_text);
186
}
187
188
__attribute__((format (gnu_printf, 2, 3), nonnull))
189
int fprintf_plus(FILE *stream, const char *format, ...){
190
va_list ap;
191
va_start (ap, format);
192
193
TEMP_FAILURE_RETRY(fprintf(stream, "Mandos plugin %s: ",
194
program_invocation_short_name));
195
return (int)TEMP_FAILURE_RETRY(vfprintf(stream, format, ap));
196
}
197
198
/*
199
* Make additional room in "buffer" for at least BUFFER_SIZE more
200
* bytes. "buffer_capacity" is how much is currently allocated,
201
* "buffer_length" is how much is already used.
202
*/
203
__attribute__((nonnull, warn_unused_result))
204
size_t incbuffer(char **buffer, size_t buffer_length,
205
size_t buffer_capacity){
206
if(buffer_length + BUFFER_SIZE > buffer_capacity){
207
char *new_buf = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
208
if(new_buf == NULL){
209
int old_errno = errno;
210
free(*buffer);
211
errno = old_errno;
212
*buffer = NULL;
213
return 0;
214
}
215
*buffer = new_buf;
216
buffer_capacity += BUFFER_SIZE;
217
}
218
return buffer_capacity;
219
}
220
221
/* Add server to set of servers to retry periodically */
222
__attribute__((nonnull, warn_unused_result))
223
bool add_server(const char *ip, in_port_t port, AvahiIfIndex if_index,
224
int af, server **current_server){
225
int ret;
226
server *new_server = malloc(sizeof(server));
227
if(new_server == NULL){
228
perror_plus("malloc");
229
return false;
230
}
231
*new_server = (server){ .ip = strdup(ip),
232
.port = port,
233
.if_index = if_index,
234
.af = af };
235
if(new_server->ip == NULL){
236
perror_plus("strdup");
237
free(new_server);
238
return false;
239
}
240
ret = clock_gettime(CLOCK_MONOTONIC, &(new_server->last_seen));
241
if(ret == -1){
242
perror_plus("clock_gettime");
243
#ifdef __GNUC__
244
#pragma GCC diagnostic push
245
#pragma GCC diagnostic ignored "-Wcast-qual"
246
#endif
247
free((char *)(new_server->ip));
248
#ifdef __GNUC__
249
#pragma GCC diagnostic pop
250
#endif
251
free(new_server);
252
return false;
253
}
254
/* Special case of first server */
255
if(*current_server == NULL){
256
new_server->next = new_server;
257
new_server->prev = new_server;
258
*current_server = new_server;
259
} else {
260
/* Place the new server last in the list */
261
new_server->next = *current_server;
262
new_server->prev = (*current_server)->prev;
263
new_server->prev->next = new_server;
264
(*current_server)->prev = new_server;
265
}
266
return true;
267
}
268
269
/*
270
* Initialize GPGME.
271
*/
272
__attribute__((nonnull, warn_unused_result))
273
static bool init_gpgme(const char * const seckey,
274
const char * const pubkey,
275
const char * const tempdir,
276
mandos_context *mc){
277
gpgme_error_t rc;
278
gpgme_engine_info_t engine_info;
279
280
/*
281
* Helper function to insert pub and seckey to the engine keyring.
282
*/
283
bool import_key(const char * const filename){
284
int ret;
285
int fd;
286
gpgme_data_t pgp_data;
287
288
fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
289
if(fd == -1){
290
perror_plus("open");
291
return false;
292
}
293
294
rc = gpgme_data_new_from_fd(&pgp_data, fd);
295
if(rc != GPG_ERR_NO_ERROR){
296
fprintf_plus(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
297
gpgme_strsource(rc), gpgme_strerror(rc));
298
return false;
299
}
300
301
rc = gpgme_op_import(mc->ctx, pgp_data);
302
if(rc != GPG_ERR_NO_ERROR){
303
fprintf_plus(stderr, "bad gpgme_op_import: %s: %s\n",
304
gpgme_strsource(rc), gpgme_strerror(rc));
305
return false;
306
}
307
308
ret = (int)TEMP_FAILURE_RETRY(close(fd));
309
if(ret == -1){
310
perror_plus("close");
311
}
312
gpgme_data_release(pgp_data);
313
return true;
314
}
315
316
if(debug){
317
fprintf_plus(stderr, "Initializing GPGME\n");
318
}
319
320
/* Init GPGME */
321
gpgme_check_version(NULL);
322
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
323
if(rc != GPG_ERR_NO_ERROR){
324
fprintf_plus(stderr, "bad gpgme_engine_check_version: %s: %s\n",
325
gpgme_strsource(rc), gpgme_strerror(rc));
326
return false;
327
}
328
329
/* Set GPGME home directory for the OpenPGP engine only */
330
rc = gpgme_get_engine_info(&engine_info);
331
if(rc != GPG_ERR_NO_ERROR){
332
fprintf_plus(stderr, "bad gpgme_get_engine_info: %s: %s\n",
333
gpgme_strsource(rc), gpgme_strerror(rc));
334
return false;
335
}
336
while(engine_info != NULL){
337
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
338
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
339
engine_info->file_name, tempdir);
340
break;
341
}
342
engine_info = engine_info->next;
343
}
344
if(engine_info == NULL){
345
fprintf_plus(stderr, "Could not set GPGME home dir to %s\n",
346
tempdir);
347
return false;
348
}
349
350
/* Create new GPGME "context" */
351
rc = gpgme_new(&(mc->ctx));
352
if(rc != GPG_ERR_NO_ERROR){
353
fprintf_plus(stderr, "Mandos plugin mandos-client: "
354
"bad gpgme_new: %s: %s\n", gpgme_strsource(rc),
355
gpgme_strerror(rc));
356
return false;
357
}
358
359
if(not import_key(pubkey) or not import_key(seckey)){
360
return false;
361
}
362
363
return true;
364
}
365
366
/*
367
* Decrypt OpenPGP data.
368
* Returns -1 on error
369
*/
370
__attribute__((nonnull, warn_unused_result))
371
static ssize_t pgp_packet_decrypt(const char *cryptotext,
372
size_t crypto_size,
373
char **plaintext,
374
mandos_context *mc){
375
gpgme_data_t dh_crypto, dh_plain;
376
gpgme_error_t rc;
377
ssize_t ret;
378
size_t plaintext_capacity = 0;
379
ssize_t plaintext_length = 0;
380
381
if(debug){
382
fprintf_plus(stderr, "Trying to decrypt OpenPGP data\n");
383
}
384
385
/* Create new GPGME data buffer from memory cryptotext */
386
rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,
387
0);
388
if(rc != GPG_ERR_NO_ERROR){
389
fprintf_plus(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
390
gpgme_strsource(rc), gpgme_strerror(rc));
391
return -1;
392
}
393
394
/* Create new empty GPGME data buffer for the plaintext */
395
rc = gpgme_data_new(&dh_plain);
396
if(rc != GPG_ERR_NO_ERROR){
397
fprintf_plus(stderr, "Mandos plugin mandos-client: "
398
"bad gpgme_data_new: %s: %s\n",
399
gpgme_strsource(rc), gpgme_strerror(rc));
400
gpgme_data_release(dh_crypto);
401
return -1;
402
}
403
404
/* Decrypt data from the cryptotext data buffer to the plaintext
405
data buffer */
406
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
407
if(rc != GPG_ERR_NO_ERROR){
408
fprintf_plus(stderr, "bad gpgme_op_decrypt: %s: %s\n",
409
gpgme_strsource(rc), gpgme_strerror(rc));
410
plaintext_length = -1;
411
if(debug){
412
gpgme_decrypt_result_t result;
413
result = gpgme_op_decrypt_result(mc->ctx);
414
if(result == NULL){
415
fprintf_plus(stderr, "gpgme_op_decrypt_result failed\n");
416
} else {
417
fprintf_plus(stderr, "Unsupported algorithm: %s\n",
418
result->unsupported_algorithm);
419
fprintf_plus(stderr, "Wrong key usage: %u\n",
420
result->wrong_key_usage);
421
if(result->file_name != NULL){
422
fprintf_plus(stderr, "File name: %s\n", result->file_name);
423
}
424
gpgme_recipient_t recipient;
425
recipient = result->recipients;
426
while(recipient != NULL){
427
fprintf_plus(stderr, "Public key algorithm: %s\n",
428
gpgme_pubkey_algo_name
429
(recipient->pubkey_algo));
430
fprintf_plus(stderr, "Key ID: %s\n", recipient->keyid);
431
fprintf_plus(stderr, "Secret key available: %s\n",
432
recipient->status == GPG_ERR_NO_SECKEY
433
? "No" : "Yes");
434
recipient = recipient->next;
435
}
436
}
437
}
438
goto decrypt_end;
439
}
440
441
if(debug){
442
fprintf_plus(stderr, "Decryption of OpenPGP data succeeded\n");
443
}
444
445
/* Seek back to the beginning of the GPGME plaintext data buffer */
446
if(gpgme_data_seek(dh_plain, (off_t)0, SEEK_SET) == -1){
447
perror_plus("gpgme_data_seek");
448
plaintext_length = -1;
449
goto decrypt_end;
450
}
451
452
*plaintext = NULL;
453
while(true){
454
plaintext_capacity = incbuffer(plaintext,
455
(size_t)plaintext_length,
456
plaintext_capacity);
457
if(plaintext_capacity == 0){
458
perror_plus("incbuffer");
459
plaintext_length = -1;
460
goto decrypt_end;
461
}
462
463
ret = gpgme_data_read(dh_plain, *plaintext + plaintext_length,
464
BUFFER_SIZE);
465
/* Print the data, if any */
466
if(ret == 0){
467
/* EOF */
468
break;
469
}
470
if(ret < 0){
471
perror_plus("gpgme_data_read");
472
plaintext_length = -1;
473
goto decrypt_end;
474
}
475
plaintext_length += ret;
476
}
477
478
if(debug){
479
fprintf_plus(stderr, "Decrypted password is: ");
480
for(ssize_t i = 0; i < plaintext_length; i++){
481
fprintf(stderr, "%02hhX ", (*plaintext)[i]);
482
}
483
fprintf(stderr, "\n");
484
}
485
486
decrypt_end:
487
488
/* Delete the GPGME cryptotext data buffer */
489
gpgme_data_release(dh_crypto);
490
491
/* Delete the GPGME plaintext data buffer */
492
gpgme_data_release(dh_plain);
493
return plaintext_length;
494
}
495
496
__attribute__((warn_unused_result, const))
497
static const char *safe_string(const char *str){
498
if(str == NULL)
499
return "(unknown)";
500
return str;
501
}
502
503
__attribute__((warn_unused_result))
504
static const char *safer_gnutls_strerror(int value){
505
const char *ret = gnutls_strerror(value);
506
return safe_string(ret);
507
}
508
509
/* GnuTLS log function callback */
510
__attribute__((nonnull))
511
static void debuggnutls(__attribute__((unused)) int level,
512
const char* string){
513
fprintf_plus(stderr, "GnuTLS: %s", string);
514
}
515
516
__attribute__((nonnull, warn_unused_result))
517
static int init_gnutls_global(const char *pubkeyfilename,
518
const char *seckeyfilename,
519
mandos_context *mc){
520
int ret;
521
unsigned int uret;
522
523
if(debug){
524
fprintf_plus(stderr, "Initializing GnuTLS\n");
525
}
526
527
ret = gnutls_global_init();
528
if(ret != GNUTLS_E_SUCCESS){
529
fprintf_plus(stderr, "GnuTLS global_init: %s\n",
530
safer_gnutls_strerror(ret));
531
return -1;
532
}
533
534
if(debug){
535
/* "Use a log level over 10 to enable all debugging options."
536
* - GnuTLS manual
537
*/
538
gnutls_global_set_log_level(11);
539
gnutls_global_set_log_function(debuggnutls);
540
}
541
542
/* OpenPGP credentials */
543
ret = gnutls_certificate_allocate_credentials(&mc->cred);
544
if(ret != GNUTLS_E_SUCCESS){
545
fprintf_plus(stderr, "GnuTLS memory error: %s\n",
546
safer_gnutls_strerror(ret));
547
gnutls_global_deinit();
548
return -1;
549
}
550
551
if(debug){
552
fprintf_plus(stderr, "Attempting to use OpenPGP public key %s and"
553
" secret key %s as GnuTLS credentials\n",
554
pubkeyfilename,
555
seckeyfilename);
556
}
557
558
ret = gnutls_certificate_set_openpgp_key_file
559
(mc->cred, pubkeyfilename, seckeyfilename,
560
GNUTLS_OPENPGP_FMT_BASE64);
561
if(ret != GNUTLS_E_SUCCESS){
562
fprintf_plus(stderr,
563
"Error[%d] while reading the OpenPGP key pair ('%s',"
564
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
565
fprintf_plus(stderr, "The GnuTLS error is: %s\n",
566
safer_gnutls_strerror(ret));
567
goto globalfail;
568
}
569
570
/* GnuTLS server initialization */
571
ret = gnutls_dh_params_init(&mc->dh_params);
572
if(ret != GNUTLS_E_SUCCESS){
573
fprintf_plus(stderr, "Error in GnuTLS DH parameter"
574
" initialization: %s\n",
575
safer_gnutls_strerror(ret));
576
goto globalfail;
577
}
578
if(mc->dh_bits == 0){
579
/* Find out the optimal number of DH bits */
580
/* Try to read the private key file */
581
gnutls_datum_t buffer = { .data = NULL, .size = 0 };
582
{
583
int secfile = open(seckeyfilename, O_RDONLY);
584
size_t buffer_capacity = 0;
585
while(true){
586
buffer_capacity = incbuffer((char **)&buffer.data,
587
(size_t)buffer.size,
588
(size_t)buffer_capacity);
589
if(buffer_capacity == 0){
590
perror_plus("incbuffer");
591
free(buffer.data);
592
buffer.data = NULL;
593
break;
594
}
595
ssize_t bytes_read = read(secfile, buffer.data + buffer.size,
596
BUFFER_SIZE);
597
/* EOF */
598
if(bytes_read == 0){
599
break;
600
}
601
/* check bytes_read for failure */
602
if(bytes_read < 0){
603
perror_plus("read");
604
free(buffer.data);
605
buffer.data = NULL;
606
break;
607
}
608
buffer.size += (unsigned int)bytes_read;
609
}
610
close(secfile);
611
}
612
/* If successful, use buffer to parse private key */
613
gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;
614
if(buffer.data != NULL){
615
{
616
gnutls_openpgp_privkey_t privkey = NULL;
617
ret = gnutls_openpgp_privkey_init(&privkey);
618
if(ret != GNUTLS_E_SUCCESS){
619
fprintf_plus(stderr, "Error initializing OpenPGP key"
620
" structure: %s", safer_gnutls_strerror(ret));
621
free(buffer.data);
622
buffer.data = NULL;
623
} else {
624
ret = gnutls_openpgp_privkey_import(privkey, &buffer,
625
GNUTLS_OPENPGP_FMT_BASE64,
626
"", 0);
627
if(ret != GNUTLS_E_SUCCESS){
628
fprintf_plus(stderr, "Error importing OpenPGP key : %s",
629
safer_gnutls_strerror(ret));
630
privkey = NULL;
631
}
632
free(buffer.data);
633
buffer.data = NULL;
634
if(privkey != NULL){
635
/* Use private key to suggest an appropriate sec_param */
636
sec_param = gnutls_openpgp_privkey_sec_param(privkey);
637
gnutls_openpgp_privkey_deinit(privkey);
638
if(debug){
639
fprintf_plus(stderr, "This OpenPGP key implies using a"
640
" GnuTLS security parameter \"%s\".\n",
641
safe_string(gnutls_sec_param_get_name
642
(sec_param)));
643
}
644
}
645
}
646
}
647
if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){
648
/* Err on the side of caution */
649
sec_param = GNUTLS_SEC_PARAM_ULTRA;
650
if(debug){
651
fprintf_plus(stderr, "Falling back to security parameter"
652
" \"%s\"\n",
653
safe_string(gnutls_sec_param_get_name
654
(sec_param)));
655
}
656
}
657
}
658
uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);
659
if(uret != 0){
660
mc->dh_bits = uret;
661
if(debug){
662
fprintf_plus(stderr, "A \"%s\" GnuTLS security parameter"
663
" implies %u DH bits; using that.\n",
664
safe_string(gnutls_sec_param_get_name
665
(sec_param)),
666
mc->dh_bits);
667
}
668
} else {
669
fprintf_plus(stderr, "Failed to get implied number of DH"
670
" bits for security parameter \"%s\"): %s\n",
671
safe_string(gnutls_sec_param_get_name(sec_param)),
672
safer_gnutls_strerror(ret));
673
goto globalfail;
674
}
675
} else if(debug){
676
fprintf_plus(stderr, "DH bits explicitly set to %u\n",
677
mc->dh_bits);
678
}
679
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
680
if(ret != GNUTLS_E_SUCCESS){
681
fprintf_plus(stderr, "Error in GnuTLS prime generation (%u bits):"
682
" %s\n", mc->dh_bits, safer_gnutls_strerror(ret));
683
goto globalfail;
684
}
685
686
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
687
688
return 0;
689
690
globalfail:
691
692
gnutls_certificate_free_credentials(mc->cred);
693
gnutls_global_deinit();
694
gnutls_dh_params_deinit(mc->dh_params);
695
return -1;
696
}
697
698
__attribute__((nonnull, warn_unused_result))
699
static int init_gnutls_session(gnutls_session_t *session,
700
mandos_context *mc){
701
int ret;
702
/* GnuTLS session creation */
703
do {
704
ret = gnutls_init(session, GNUTLS_SERVER);
705
if(quit_now){
706
return -1;
707
}
708
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
709
if(ret != GNUTLS_E_SUCCESS){
710
fprintf_plus(stderr,
711
"Error in GnuTLS session initialization: %s\n",
712
safer_gnutls_strerror(ret));
713
}
714
715
{
716
const char *err;
717
do {
718
ret = gnutls_priority_set_direct(*session, mc->priority, &err);
719
if(quit_now){
720
gnutls_deinit(*session);
721
return -1;
722
}
723
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
724
if(ret != GNUTLS_E_SUCCESS){
725
fprintf_plus(stderr, "Syntax error at: %s\n", err);
726
fprintf_plus(stderr, "GnuTLS error: %s\n",
727
safer_gnutls_strerror(ret));
728
gnutls_deinit(*session);
729
return -1;
730
}
731
}
732
733
do {
734
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
735
mc->cred);
736
if(quit_now){
737
gnutls_deinit(*session);
738
return -1;
739
}
740
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
741
if(ret != GNUTLS_E_SUCCESS){
742
fprintf_plus(stderr, "Error setting GnuTLS credentials: %s\n",
743
safer_gnutls_strerror(ret));
744
gnutls_deinit(*session);
745
return -1;
746
}
747
748
/* ignore client certificate if any. */
749
gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);
750
751
gnutls_dh_set_prime_bits(*session, mc->dh_bits);
752
753
return 0;
754
}
755
756
/* Avahi log function callback */
757
static void empty_log(__attribute__((unused)) AvahiLogLevel level,
758
__attribute__((unused)) const char *txt){}
759
760
/* Set effective uid to 0, return errno */
761
__attribute__((warn_unused_result))
762
error_t raise_privileges(void){
763
error_t old_errno = errno;
764
error_t ret_errno = 0;
765
if(seteuid(0) == -1){
766
ret_errno = errno;
767
}
768
errno = old_errno;
769
return ret_errno;
770
}
771
772
/* Set effective and real user ID to 0. Return errno. */
773
__attribute__((warn_unused_result))
774
error_t raise_privileges_permanently(void){
775
error_t old_errno = errno;
776
error_t ret_errno = raise_privileges();
777
if(ret_errno != 0){
778
errno = old_errno;
779
return ret_errno;
780
}
781
if(setuid(0) == -1){
782
ret_errno = errno;
783
}
784
errno = old_errno;
785
return ret_errno;
786
}
787
788
/* Set effective user ID to unprivileged saved user ID */
789
__attribute__((warn_unused_result))
790
error_t lower_privileges(void){
791
error_t old_errno = errno;
792
error_t ret_errno = 0;
793
if(seteuid(uid) == -1){
794
ret_errno = errno;
795
}
796
errno = old_errno;
797
return ret_errno;
798
}
799
800
/* Lower privileges permanently */
801
__attribute__((warn_unused_result))
802
error_t lower_privileges_permanently(void){
803
error_t old_errno = errno;
804
error_t ret_errno = 0;
805
if(setuid(uid) == -1){
806
ret_errno = errno;
807
}
808
errno = old_errno;
809
return ret_errno;
810
}
811
812
/* Helper function to add_local_route() and delete_local_route() */
813
__attribute__((nonnull, warn_unused_result))
814
static bool add_delete_local_route(const bool add,
815
const char *address,
816
AvahiIfIndex if_index){
817
int ret;
818
char helper[] = "mandos-client-iprouteadddel";
819
char add_arg[] = "add";
820
char delete_arg[] = "delete";
821
char debug_flag[] = "--debug";
822
char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");
823
if(pluginhelperdir == NULL){
824
if(debug){
825
fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"
826
" variable not set; cannot run helper\n");
827
}
828
return false;
829
}
830
831
char interface[IF_NAMESIZE];
832
if(if_indextoname((unsigned int)if_index, interface) == NULL){
833
perror_plus("if_indextoname");
834
return false;
835
}
836
837
int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));
838
if(devnull == -1){
839
perror_plus("open(\"/dev/null\", O_RDONLY)");
840
return false;
841
}
842
pid_t pid = fork();
843
if(pid == 0){
844
/* Child */
845
/* Raise privileges */
846
errno = raise_privileges_permanently();
847
if(errno != 0){
848
perror_plus("Failed to raise privileges");
849
/* _exit(EX_NOPERM); */
850
} else {
851
/* Set group */
852
errno = 0;
853
ret = setgid(0);
854
if(ret == -1){
855
perror_plus("setgid");
856
_exit(EX_NOPERM);
857
}
858
/* Reset supplementary groups */
859
errno = 0;
860
ret = setgroups(0, NULL);
861
if(ret == -1){
862
perror_plus("setgroups");
863
_exit(EX_NOPERM);
864
}
865
}
866
ret = dup2(devnull, STDIN_FILENO);
867
if(ret == -1){
868
perror_plus("dup2(devnull, STDIN_FILENO)");
869
_exit(EX_OSERR);
870
}
871
ret = (int)TEMP_FAILURE_RETRY(close(devnull));
872
if(ret == -1){
873
perror_plus("close");
874
_exit(EX_OSERR);
875
}
876
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
877
if(ret == -1){
878
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
879
_exit(EX_OSERR);
880
}
881
int helperdir_fd = (int)TEMP_FAILURE_RETRY(open(pluginhelperdir,
882
O_RDONLY
883
| O_DIRECTORY
884
| O_PATH
885
| O_CLOEXEC));
886
if(helperdir_fd == -1){
887
perror_plus("open");
888
_exit(EX_UNAVAILABLE);
889
}
890
int helper_fd = (int)TEMP_FAILURE_RETRY(openat(helperdir_fd,
891
helper, O_RDONLY));
892
if(helper_fd == -1){
893
perror_plus("openat");
894
_exit(EX_UNAVAILABLE);
895
}
896
TEMP_FAILURE_RETRY(close(helperdir_fd));
897
#ifdef __GNUC__
898
#pragma GCC diagnostic push
899
#pragma GCC diagnostic ignored "-Wcast-qual"
900
#endif
901
if(fexecve(helper_fd, (char *const [])
902
{ helper, add ? add_arg : delete_arg, (char *)address,
903
interface, debug ? debug_flag : NULL, NULL },
904
environ) == -1){
905
#ifdef __GNUC__
906
#pragma GCC diagnostic pop
907
#endif
908
perror_plus("fexecve");
909
_exit(EXIT_FAILURE);
910
}
911
}
912
if(pid == -1){
913
perror_plus("fork");
914
return false;
915
}
916
int status;
917
pid_t pret = -1;
918
errno = 0;
919
do {
920
pret = waitpid(pid, &status, 0);
921
if(pret == -1 and errno == EINTR and quit_now){
922
int errno_raising = 0;
923
if((errno = raise_privileges()) != 0){
924
errno_raising = errno;
925
perror_plus("Failed to raise privileges in order to"
926
" kill helper program");
927
}
928
if(kill(pid, SIGTERM) == -1){
929
perror_plus("kill");
930
}
931
if((errno_raising == 0) and (errno = lower_privileges()) != 0){
932
perror_plus("Failed to lower privileges after killing"
933
" helper program");
934
}
935
return false;
936
}
937
} while(pret == -1 and errno == EINTR);
938
if(pret == -1){
939
perror_plus("waitpid");
940
return false;
941
}
942
if(WIFEXITED(status)){
943
if(WEXITSTATUS(status) != 0){
944
fprintf_plus(stderr, "Error: iprouteadddel exited"
945
" with status %d\n", WEXITSTATUS(status));
946
return false;
947
}
948
return true;
949
}
950
if(WIFSIGNALED(status)){
951
fprintf_plus(stderr, "Error: iprouteadddel died by"
952
" signal %d\n", WTERMSIG(status));
953
return false;
954
}
955
fprintf_plus(stderr, "Error: iprouteadddel crashed\n");
956
return false;
957
}
958
959
__attribute__((nonnull, warn_unused_result))
960
static bool add_local_route(const char *address,
961
AvahiIfIndex if_index){
962
if(debug){
963
fprintf_plus(stderr, "Adding route to %s\n", address);
964
}
965
return add_delete_local_route(true, address, if_index);
966
}
967
968
__attribute__((nonnull, warn_unused_result))
969
static bool delete_local_route(const char *address,
970
AvahiIfIndex if_index){
971
if(debug){
972
fprintf_plus(stderr, "Removing route to %s\n", address);
973
}
974
return add_delete_local_route(false, address, if_index);
975
}
976
977
/* Called when a Mandos server is found */
978
__attribute__((nonnull, warn_unused_result))
979
static int start_mandos_communication(const char *ip, in_port_t port,
980
AvahiIfIndex if_index,
981
int af, mandos_context *mc){
982
int ret, tcp_sd = -1;
983
ssize_t sret;
984
struct sockaddr_storage to;
985
char *buffer = NULL;
986
char *decrypted_buffer = NULL;
987
size_t buffer_length = 0;
988
size_t buffer_capacity = 0;
989
size_t written;
990
int retval = -1;
991
gnutls_session_t session;
992
int pf; /* Protocol family */
993
bool route_added = false;
994
995
errno = 0;
996
997
if(quit_now){
998
errno = EINTR;
999
return -1;
1000
}
1001
1002
switch(af){
1003
case AF_INET6:
1004
pf = PF_INET6;
1005
break;
1006
case AF_INET:
1007
pf = PF_INET;
1008
break;
1009
default:
1010
fprintf_plus(stderr, "Bad address family: %d\n", af);
1011
errno = EINVAL;
1012
return -1;
1013
}
1014
1015
/* If the interface is specified and we have a list of interfaces */
1016
if(if_index != AVAHI_IF_UNSPEC and mc->interfaces != NULL){
1017
/* Check if the interface is one of the interfaces we are using */
1018
bool match = false;
1019
{
1020
char *interface = NULL;
1021
while((interface=argz_next(mc->interfaces, mc->interfaces_size,
1022
interface))){
1023
if(if_nametoindex(interface) == (unsigned int)if_index){
1024
match = true;
1025
break;
1026
}
1027
}
1028
}
1029
if(not match){
1030
/* This interface does not match any in the list, so we don't
1031
connect to the server */
1032
if(debug){
1033
char interface[IF_NAMESIZE];
1034
if(if_indextoname((unsigned int)if_index, interface) == NULL){
1035
perror_plus("if_indextoname");
1036
} else {
1037
fprintf_plus(stderr, "Skipping server on non-used interface"
1038
" \"%s\"\n",
1039
if_indextoname((unsigned int)if_index,
1040
interface));
1041
}
1042
}
1043
return -1;
1044
}
1045
}
1046
1047
ret = init_gnutls_session(&session, mc);
1048
if(ret != 0){
1049
return -1;
1050
}
1051
1052
if(debug){
1053
fprintf_plus(stderr, "Setting up a TCP connection to %s, port %"
1054
PRIuMAX "\n", ip, (uintmax_t)port);
1055
}
1056
1057
tcp_sd = socket(pf, SOCK_STREAM | SOCK_CLOEXEC, 0);
1058
if(tcp_sd < 0){
1059
int e = errno;
1060
perror_plus("socket");
1061
errno = e;
1062
goto mandos_end;
1063
}
1064
1065
if(quit_now){
1066
errno = EINTR;
1067
goto mandos_end;
1068
}
1069
1070
memset(&to, 0, sizeof(to));
1071
if(af == AF_INET6){
1072
((struct sockaddr_in6 *)&to)->sin6_family = (sa_family_t)af;
1073
ret = inet_pton(af, ip, &((struct sockaddr_in6 *)&to)->sin6_addr);
1074
} else { /* IPv4 */
1075
((struct sockaddr_in *)&to)->sin_family = (sa_family_t)af;
1076
ret = inet_pton(af, ip, &((struct sockaddr_in *)&to)->sin_addr);
1077
}
1078
if(ret < 0 ){
1079
int e = errno;
1080
perror_plus("inet_pton");
1081
errno = e;
1082
goto mandos_end;
1083
}
1084
if(ret == 0){
1085
int e = errno;
1086
fprintf_plus(stderr, "Bad address: %s\n", ip);
1087
errno = e;
1088
goto mandos_end;
1089
}
1090
if(af == AF_INET6){
1091
((struct sockaddr_in6 *)&to)->sin6_port = htons(port);
1092
if(IN6_IS_ADDR_LINKLOCAL
1093
(&((struct sockaddr_in6 *)&to)->sin6_addr)){
1094
if(if_index == AVAHI_IF_UNSPEC){
1095
fprintf_plus(stderr, "An IPv6 link-local address is"
1096
" incomplete without a network interface\n");
1097
errno = EINVAL;
1098
goto mandos_end;
1099
}
1100
/* Set the network interface number as scope */
1101
((struct sockaddr_in6 *)&to)->sin6_scope_id = (uint32_t)if_index;
1102
}
1103
} else {
1104
((struct sockaddr_in *)&to)->sin_port = htons(port);
1105
}
1106
1107
if(quit_now){
1108
errno = EINTR;
1109
goto mandos_end;
1110
}
1111
1112
if(debug){
1113
if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){
1114
char interface[IF_NAMESIZE];
1115
if(if_indextoname((unsigned int)if_index, interface) == NULL){
1116
perror_plus("if_indextoname");
1117
} else {
1118
fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIuMAX
1119
"\n", ip, interface, (uintmax_t)port);
1120
}
1121
} else {
1122
fprintf_plus(stderr, "Connection to: %s, port %" PRIuMAX "\n",
1123
ip, (uintmax_t)port);
1124
}
1125
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
1126
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
1127
if(af == AF_INET6){
1128
ret = getnameinfo((struct sockaddr *)&to,
1129
sizeof(struct sockaddr_in6),
1130
addrstr, sizeof(addrstr), NULL, 0,
1131
NI_NUMERICHOST);
1132
} else {
1133
ret = getnameinfo((struct sockaddr *)&to,
1134
sizeof(struct sockaddr_in),
1135
addrstr, sizeof(addrstr), NULL, 0,
1136
NI_NUMERICHOST);
1137
}
1138
if(ret == EAI_SYSTEM){
1139
perror_plus("getnameinfo");
1140
} else if(ret != 0) {
1141
fprintf_plus(stderr, "getnameinfo: %s", gai_strerror(ret));
1142
} else if(strcmp(addrstr, ip) != 0){
1143
fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);
1144
}
1145
}
1146
1147
if(quit_now){
1148
errno = EINTR;
1149
goto mandos_end;
1150
}
1151
1152
while(true){
1153
if(af == AF_INET6){
1154
ret = connect(tcp_sd, (struct sockaddr *)&to,
1155
sizeof(struct sockaddr_in6));
1156
} else {
1157
ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */
1158
sizeof(struct sockaddr_in));
1159
}
1160
if(ret < 0){
1161
if(errno == ENETUNREACH
1162
and if_index != AVAHI_IF_UNSPEC
1163
and connect_to == NULL
1164
and not route_added and
1165
((af == AF_INET6 and not
1166
IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)
1167
&to)->sin6_addr)))
1168
or (af == AF_INET and
1169
/* Not a a IPv4LL address */
1170
(ntohl(((struct sockaddr_in *)&to)->sin_addr.s_addr)
1171
& 0xFFFF0000L) != 0xA9FE0000L))){
1172
/* Work around Avahi bug - Avahi does not announce link-local
1173
addresses if it has a global address, so local hosts with
1174
*only* a link-local address (e.g. Mandos clients) cannot
1175
connect to a Mandos server announced by Avahi on a server
1176
host with a global address. Work around this by retrying
1177
with an explicit route added with the server's address.
1178
1179
Avahi bug reference:
1180
http://lists.freedesktop.org/archives/avahi/2010-February/001833.html
1181
https://bugs.debian.org/587961
1182
*/
1183
if(debug){
1184
fprintf_plus(stderr, "Mandos server unreachable, trying"
1185
" direct route\n");
1186
}
1187
int e = errno;
1188
route_added = add_local_route(ip, if_index);
1189
if(route_added){
1190
continue;
1191
}
1192
errno = e;
1193
}
1194
if(errno != ECONNREFUSED or debug){
1195
int e = errno;
1196
perror_plus("connect");
1197
errno = e;
1198
}
1199
goto mandos_end;
1200
}
1201
1202
if(quit_now){
1203
errno = EINTR;
1204
goto mandos_end;
1205
}
1206
break;
1207
}
1208
1209
const char *out = mandos_protocol_version;
1210
written = 0;
1211
while(true){
1212
size_t out_size = strlen(out);
1213
ret = (int)TEMP_FAILURE_RETRY(write(tcp_sd, out + written,
1214
out_size - written));
1215
if(ret == -1){
1216
int e = errno;
1217
perror_plus("write");
1218
errno = e;
1219
goto mandos_end;
1220
}
1221
written += (size_t)ret;
1222
if(written < out_size){
1223
continue;
1224
} else {
1225
if(out == mandos_protocol_version){
1226
written = 0;
1227
out = "\r\n";
1228
} else {
1229
break;
1230
}
1231
}
1232
1233
if(quit_now){
1234
errno = EINTR;
1235
goto mandos_end;
1236
}
1237
}
1238
1239
if(debug){
1240
fprintf_plus(stderr, "Establishing TLS session with %s\n", ip);
1241
}
1242
1243
if(quit_now){
1244
errno = EINTR;
1245
goto mandos_end;
1246
}
1247
1248
/* This casting via intptr_t is to eliminate warning about casting
1249
an int to a pointer type. This is exactly how the GnuTLS Guile
1250
function "set-session-transport-fd!" does it. */
1251
gnutls_transport_set_ptr(session,
1252
(gnutls_transport_ptr_t)(intptr_t)tcp_sd);
1253
1254
if(quit_now){
1255
errno = EINTR;
1256
goto mandos_end;
1257
}
1258
1259
do {
1260
ret = gnutls_handshake(session);
1261
if(quit_now){
1262
errno = EINTR;
1263
goto mandos_end;
1264
}
1265
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
1266
1267
if(ret != GNUTLS_E_SUCCESS){
1268
if(debug){
1269
fprintf_plus(stderr, "*** GnuTLS Handshake failed ***\n");
1270
gnutls_perror(ret);
1271
}
1272
errno = EPROTO;
1273
goto mandos_end;
1274
}
1275
1276
/* Read OpenPGP packet that contains the wanted password */
1277
1278
if(debug){
1279
fprintf_plus(stderr, "Retrieving OpenPGP encrypted password from"
1280
" %s\n", ip);
1281
}
1282
1283
while(true){
1284
1285
if(quit_now){
1286
errno = EINTR;
1287
goto mandos_end;
1288
}
1289
1290
buffer_capacity = incbuffer(&buffer, buffer_length,
1291
buffer_capacity);
1292
if(buffer_capacity == 0){
1293
int e = errno;
1294
perror_plus("incbuffer");
1295
errno = e;
1296
goto mandos_end;
1297
}
1298
1299
if(quit_now){
1300
errno = EINTR;
1301
goto mandos_end;
1302
}
1303
1304
sret = gnutls_record_recv(session, buffer+buffer_length,
1305
BUFFER_SIZE);
1306
if(sret == 0){
1307
break;
1308
}
1309
if(sret < 0){
1310
switch(sret){
1311
case GNUTLS_E_INTERRUPTED:
1312
case GNUTLS_E_AGAIN:
1313
break;
1314
case GNUTLS_E_REHANDSHAKE:
1315
do {
1316
ret = gnutls_handshake(session);
1317
1318
if(quit_now){
1319
errno = EINTR;
1320
goto mandos_end;
1321
}
1322
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
1323
if(ret < 0){
1324
fprintf_plus(stderr, "*** GnuTLS Re-handshake failed "
1325
"***\n");
1326
gnutls_perror(ret);
1327
errno = EPROTO;
1328
goto mandos_end;
1329
}
1330
break;
1331
default:
1332
fprintf_plus(stderr, "Unknown error while reading data from"
1333
" encrypted session with Mandos server\n");
1334
gnutls_bye(session, GNUTLS_SHUT_RDWR);
1335
errno = EIO;
1336
goto mandos_end;
1337
}
1338
} else {
1339
buffer_length += (size_t) sret;
1340
}
1341
}
1342
1343
if(debug){
1344
fprintf_plus(stderr, "Closing TLS session\n");
1345
}
1346
1347
if(quit_now){
1348
errno = EINTR;
1349
goto mandos_end;
1350
}
1351
1352
do {
1353
ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);
1354
if(quit_now){
1355
errno = EINTR;
1356
goto mandos_end;
1357
}
1358
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
1359
1360
if(buffer_length > 0){
1361
ssize_t decrypted_buffer_size;
1362
decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,
1363
&decrypted_buffer, mc);
1364
if(decrypted_buffer_size >= 0){
1365
1366
written = 0;
1367
while(written < (size_t) decrypted_buffer_size){
1368
if(quit_now){
1369
errno = EINTR;
1370
goto mandos_end;
1371
}
1372
1373
ret = (int)fwrite(decrypted_buffer + written, 1,
1374
(size_t)decrypted_buffer_size - written,
1375
stdout);
1376
if(ret == 0 and ferror(stdout)){
1377
int e = errno;
1378
if(debug){
1379
fprintf_plus(stderr, "Error writing encrypted data: %s\n",
1380
strerror(errno));
1381
}
1382
errno = e;
1383
goto mandos_end;
1384
}
1385
written += (size_t)ret;
1386
}
1387
retval = 0;
1388
}
1389
}
1390
1391
/* Shutdown procedure */
1392
1393
mandos_end:
1394
{
1395
if(route_added){
1396
if(not delete_local_route(ip, if_index)){
1397
fprintf_plus(stderr, "Failed to delete local route to %s on"
1398
" interface %d", ip, if_index);
1399
}
1400
}
1401
int e = errno;
1402
free(decrypted_buffer);
1403
free(buffer);
1404
if(tcp_sd >= 0){
1405
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
1406
}
1407
if(ret == -1){
1408
if(e == 0){
1409
e = errno;
1410
}
1411
perror_plus("close");
1412
}
1413
gnutls_deinit(session);
1414
errno = e;
1415
if(quit_now){
1416
errno = EINTR;
1417
retval = -1;
1418
}
1419
}
1420
return retval;
1421
}
1422
1423
__attribute__((nonnull))
1424
static void resolve_callback(AvahiSServiceResolver *r,
1425
AvahiIfIndex interface,
1426
AvahiProtocol proto,
1427
AvahiResolverEvent event,
1428
const char *name,
1429
const char *type,
1430
const char *domain,
1431
const char *host_name,
1432
const AvahiAddress *address,
1433
uint16_t port,
1434
AVAHI_GCC_UNUSED AvahiStringList *txt,
1435
AVAHI_GCC_UNUSED AvahiLookupResultFlags
1436
flags,
1437
void *mc){
1438
if(r == NULL){
1439
return;
1440
}
1441
1442
/* Called whenever a service has been resolved successfully or
1443
timed out */
1444
1445
if(quit_now){
1446
avahi_s_service_resolver_free(r);
1447
return;
1448
}
1449
1450
switch(event){
1451
default:
1452
case AVAHI_RESOLVER_FAILURE:
1453
fprintf_plus(stderr, "(Avahi Resolver) Failed to resolve service "
1454
"'%s' of type '%s' in domain '%s': %s\n", name, type,
1455
domain,
1456
avahi_strerror(avahi_server_errno
1457
(((mandos_context*)mc)->server)));
1458
break;
1459
1460
case AVAHI_RESOLVER_FOUND:
1461
{
1462
char ip[AVAHI_ADDRESS_STR_MAX];
1463
avahi_address_snprint(ip, sizeof(ip), address);
1464
if(debug){
1465
fprintf_plus(stderr, "Mandos server \"%s\" found on %s (%s, %"
1466
PRIdMAX ") on port %" PRIu16 "\n", name,
1467
host_name, ip, (intmax_t)interface, port);
1468
}
1469
int ret = start_mandos_communication(ip, (in_port_t)port,
1470
interface,
1471
avahi_proto_to_af(proto),
1472
mc);
1473
if(ret == 0){
1474
avahi_simple_poll_quit(simple_poll);
1475
} else {
1476
if(not add_server(ip, (in_port_t)port, interface,
1477
avahi_proto_to_af(proto),
1478
&((mandos_context*)mc)->current_server)){
1479
fprintf_plus(stderr, "Failed to add server \"%s\" to server"
1480
" list\n", name);
1481
}
1482
}
1483
}
1484
}
1485
avahi_s_service_resolver_free(r);
1486
}
1487
1488
static void browse_callback(AvahiSServiceBrowser *b,
1489
AvahiIfIndex interface,
1490
AvahiProtocol protocol,
1491
AvahiBrowserEvent event,
1492
const char *name,
1493
const char *type,
1494
const char *domain,
1495
AVAHI_GCC_UNUSED AvahiLookupResultFlags
1496
flags,
1497
void *mc){
1498
if(b == NULL){
1499
return;
1500
}
1501
1502
/* Called whenever a new services becomes available on the LAN or
1503
is removed from the LAN */
1504
1505
if(quit_now){
1506
return;
1507
}
1508
1509
switch(event){
1510
default:
1511
case AVAHI_BROWSER_FAILURE:
1512
1513
fprintf_plus(stderr, "(Avahi browser) %s\n",
1514
avahi_strerror(avahi_server_errno
1515
(((mandos_context*)mc)->server)));
1516
avahi_simple_poll_quit(simple_poll);
1517
return;
1518
1519
case AVAHI_BROWSER_NEW:
1520
/* We ignore the returned Avahi resolver object. In the callback
1521
function we free it. If the Avahi server is terminated before
1522
the callback function is called the Avahi server will free the
1523
resolver for us. */
1524
1525
if(avahi_s_service_resolver_new(((mandos_context*)mc)->server,
1526
interface, protocol, name, type,
1527
domain, protocol, 0,
1528
resolve_callback, mc) == NULL)
1529
fprintf_plus(stderr, "Avahi: Failed to resolve service '%s':"
1530
" %s\n", name,
1531
avahi_strerror(avahi_server_errno
1532
(((mandos_context*)mc)->server)));
1533
break;
1534
1535
case AVAHI_BROWSER_REMOVE:
1536
break;
1537
1538
case AVAHI_BROWSER_ALL_FOR_NOW:
1539
case AVAHI_BROWSER_CACHE_EXHAUSTED:
1540
if(debug){
1541
fprintf_plus(stderr, "No Mandos server found, still"
1542
" searching...\n");
1543
}
1544
break;
1545
}
1546
}
1547
1548
/* Signal handler that stops main loop after SIGTERM */
1549
static void handle_sigterm(int sig){
1550
if(quit_now){
1551
return;
1552
}
1553
quit_now = 1;
1554
signal_received = sig;
1555
int old_errno = errno;
1556
/* set main loop to exit */
1557
if(simple_poll != NULL){
1558
avahi_simple_poll_quit(simple_poll);
1559
}
1560
errno = old_errno;
1561
}
1562
1563
__attribute__((nonnull, warn_unused_result))
1564
bool get_flags(const char *ifname, struct ifreq *ifr){
1565
int ret;
1566
error_t ret_errno;
1567
1568
int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1569
if(s < 0){
1570
ret_errno = errno;
1571
perror_plus("socket");
1572
errno = ret_errno;
1573
return false;
1574
}
1575
strcpy(ifr->ifr_name, ifname);
1576
ret = ioctl(s, SIOCGIFFLAGS, ifr);
1577
if(ret == -1){
1578
if(debug){
1579
ret_errno = errno;
1580
perror_plus("ioctl SIOCGIFFLAGS");
1581
errno = ret_errno;
1582
}
1583
return false;
1584
}
1585
return true;
1586
}
1587
1588
__attribute__((nonnull, warn_unused_result))
1589
bool good_flags(const char *ifname, const struct ifreq *ifr){
1590
1591
/* Reject the loopback device */
1592
if(ifr->ifr_flags & IFF_LOOPBACK){
1593
if(debug){
1594
fprintf_plus(stderr, "Rejecting loopback interface \"%s\"\n",
1595
ifname);
1596
}
1597
return false;
1598
}
1599
/* Accept point-to-point devices only if connect_to is specified */
1600
if(connect_to != NULL and (ifr->ifr_flags & IFF_POINTOPOINT)){
1601
if(debug){
1602
fprintf_plus(stderr, "Accepting point-to-point interface"
1603
" \"%s\"\n", ifname);
1604
}
1605
return true;
1606
}
1607
/* Otherwise, reject non-broadcast-capable devices */
1608
if(not (ifr->ifr_flags & IFF_BROADCAST)){
1609
if(debug){
1610
fprintf_plus(stderr, "Rejecting non-broadcast interface"
1611
" \"%s\"\n", ifname);
1612
}
1613
return false;
1614
}
1615
/* Reject non-ARP interfaces (including dummy interfaces) */
1616
if(ifr->ifr_flags & IFF_NOARP){
1617
if(debug){
1618
fprintf_plus(stderr, "Rejecting non-ARP interface \"%s\"\n",
1619
ifname);
1620
}
1621
return false;
1622
}
1623
1624
/* Accept this device */
1625
if(debug){
1626
fprintf_plus(stderr, "Interface \"%s\" is good\n", ifname);
1627
}
1628
return true;
1629
}
1630
1631
/*
1632
* This function determines if a directory entry in /sys/class/net
1633
* corresponds to an acceptable network device.
1634
* (This function is passed to scandir(3) as a filter function.)
1635
*/
1636
__attribute__((nonnull, warn_unused_result))
1637
int good_interface(const struct dirent *if_entry){
1638
if(if_entry->d_name[0] == '.'){
1639
return 0;
1640
}
1641
1642
struct ifreq ifr;
1643
if(not get_flags(if_entry->d_name, &ifr)){
1644
if(debug){
1645
fprintf_plus(stderr, "Failed to get flags for interface "
1646
"\"%s\"\n", if_entry->d_name);
1647
}
1648
return 0;
1649
}
1650
1651
if(not good_flags(if_entry->d_name, &ifr)){
1652
return 0;
1653
}
1654
return 1;
1655
}
1656
1657
/*
1658
* This function determines if a network interface is up.
1659
*/
1660
__attribute__((nonnull, warn_unused_result))
1661
bool interface_is_up(const char *interface){
1662
struct ifreq ifr;
1663
if(not get_flags(interface, &ifr)){
1664
if(debug){
1665
fprintf_plus(stderr, "Failed to get flags for interface "
1666
"\"%s\"\n", interface);
1667
}
1668
return false;
1669
}
1670
1671
return (bool)(ifr.ifr_flags & IFF_UP);
1672
}
1673
1674
/*
1675
* This function determines if a network interface is running
1676
*/
1677
__attribute__((nonnull, warn_unused_result))
1678
bool interface_is_running(const char *interface){
1679
struct ifreq ifr;
1680
if(not get_flags(interface, &ifr)){
1681
if(debug){
1682
fprintf_plus(stderr, "Failed to get flags for interface "
1683
"\"%s\"\n", interface);
1684
}
1685
return false;
1686
}
1687
1688
return (bool)(ifr.ifr_flags & IFF_RUNNING);
1689
}
1690
1691
__attribute__((nonnull, pure, warn_unused_result))
1692
int notdotentries(const struct dirent *direntry){
1693
/* Skip "." and ".." */
1694
if(direntry->d_name[0] == '.'
1695
and (direntry->d_name[1] == '\0'
1696
or (direntry->d_name[1] == '.'
1697
and direntry->d_name[2] == '\0'))){
1698
return 0;
1699
}
1700
return 1;
1701
}
1702
1703
/* Is this directory entry a runnable program? */
1704
__attribute__((nonnull, warn_unused_result))
1705
int runnable_hook(const struct dirent *direntry){
1706
int ret;
1707
size_t sret;
1708
struct stat st;
1709
1710
if((direntry->d_name)[0] == '\0'){
1711
/* Empty name? */
1712
return 0;
1713
}
1714
1715
sret = strspn(direntry->d_name, "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
1716
"abcdefghijklmnopqrstuvwxyz"
1717
"0123456789"
1718
"_.-");
1719
if((direntry->d_name)[sret] != '\0'){
1720
/* Contains non-allowed characters */
1721
if(debug){
1722
fprintf_plus(stderr, "Ignoring hook \"%s\" with bad name\n",
1723
direntry->d_name);
1724
}
1725
return 0;
1726
}
1727
1728
ret = fstatat(hookdir_fd, direntry->d_name, &st, 0);
1729
if(ret == -1){
1730
if(debug){
1731
perror_plus("Could not stat hook");
1732
}
1733
return 0;
1734
}
1735
if(not (S_ISREG(st.st_mode))){
1736
/* Not a regular file */
1737
if(debug){
1738
fprintf_plus(stderr, "Ignoring hook \"%s\" - not a file\n",
1739
direntry->d_name);
1740
}
1741
return 0;
1742
}
1743
if(not (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))){
1744
/* Not executable */
1745
if(debug){
1746
fprintf_plus(stderr, "Ignoring hook \"%s\" - not executable\n",
1747
direntry->d_name);
1748
}
1749
return 0;
1750
}
1751
if(debug){
1752
fprintf_plus(stderr, "Hook \"%s\" is acceptable\n",
1753
direntry->d_name);
1754
}
1755
return 1;
1756
}
1757
1758
__attribute__((nonnull, warn_unused_result))
1759
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,
1760
mandos_context *mc){
1761
int ret;
1762
struct timespec now;
1763
struct timespec waited_time;
1764
intmax_t block_time;
1765
1766
while(true){
1767
if(mc->current_server == NULL){
1768
if(debug){
1769
fprintf_plus(stderr, "Wait until first server is found."
1770
" No timeout!\n");
1771
}
1772
ret = avahi_simple_poll_iterate(s, -1);
1773
} else {
1774
if(debug){
1775
fprintf_plus(stderr, "Check current_server if we should run"
1776
" it, or wait\n");
1777
}
1778
/* the current time */
1779
ret = clock_gettime(CLOCK_MONOTONIC, &now);
1780
if(ret == -1){
1781
perror_plus("clock_gettime");
1782
return -1;
1783
}
1784
/* Calculating in ms how long time between now and server
1785
who we visted longest time ago. Now - last seen. */
1786
waited_time.tv_sec = (now.tv_sec
1787
- mc->current_server->last_seen.tv_sec);
1788
waited_time.tv_nsec = (now.tv_nsec
1789
- mc->current_server->last_seen.tv_nsec);
1790
/* total time is 10s/10,000ms.
1791
Converting to s from ms by dividing by 1,000,
1792
and ns to ms by dividing by 1,000,000. */
1793
block_time = ((retry_interval
1794
- ((intmax_t)waited_time.tv_sec * 1000))
1795
- ((intmax_t)waited_time.tv_nsec / 1000000));
1796
1797
if(debug){
1798
fprintf_plus(stderr, "Blocking for %" PRIdMAX " ms\n",
1799
block_time);
1800
}
1801
1802
if(block_time <= 0){
1803
ret = start_mandos_communication(mc->current_server->ip,
1804
mc->current_server->port,
1805
mc->current_server->if_index,
1806
mc->current_server->af, mc);
1807
if(ret == 0){
1808
avahi_simple_poll_quit(s);
1809
return 0;
1810
}
1811
ret = clock_gettime(CLOCK_MONOTONIC,
1812
&mc->current_server->last_seen);
1813
if(ret == -1){
1814
perror_plus("clock_gettime");
1815
return -1;
1816
}
1817
mc->current_server = mc->current_server->next;
1818
block_time = 0; /* Call avahi to find new Mandos
1819
servers, but don't block */
1820
}
1821
1822
ret = avahi_simple_poll_iterate(s, (int)block_time);
1823
}
1824
if(ret != 0){
1825
if(ret > 0 or errno != EINTR){
1826
return (ret != 1) ? ret : 0;
1827
}
1828
}
1829
}
1830
}
1831
1832
__attribute__((nonnull))
1833
void run_network_hooks(const char *mode, const char *interface,
1834
const float delay){
1835
struct dirent **direntries = NULL;
1836
if(hookdir_fd == -1){
1837
hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH
1838
| O_CLOEXEC);
1839
if(hookdir_fd == -1){
1840
if(errno == ENOENT){
1841
if(debug){
1842
fprintf_plus(stderr, "Network hook directory \"%s\" not"
1843
" found\n", hookdir);
1844
}
1845
} else {
1846
perror_plus("open");
1847
}
1848
return;
1849
}
1850
}
1851
#ifdef __GLIBC__
1852
#if __GLIBC_PREREQ(2, 15)
1853
int numhooks = scandirat(hookdir_fd, ".", &direntries,
1854
runnable_hook, alphasort);
1855
#else /* not __GLIBC_PREREQ(2, 15) */
1856
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1857
alphasort);
1858
#endif /* not __GLIBC_PREREQ(2, 15) */
1859
#else /* not __GLIBC__ */
1860
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1861
alphasort);
1862
#endif /* not __GLIBC__ */
1863
if(numhooks == -1){
1864
perror_plus("scandir");
1865
return;
1866
}
1867
struct dirent *direntry;
1868
int ret;
1869
int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));
1870
if(devnull == -1){
1871
perror_plus("open(\"/dev/null\", O_RDONLY)");
1872
return;
1873
}
1874
for(int i = 0; i < numhooks; i++){
1875
direntry = direntries[i];
1876
if(debug){
1877
fprintf_plus(stderr, "Running network hook \"%s\"\n",
1878
direntry->d_name);
1879
}
1880
pid_t hook_pid = fork();
1881
if(hook_pid == 0){
1882
/* Child */
1883
/* Raise privileges */
1884
errno = raise_privileges_permanently();
1885
if(errno != 0){
1886
perror_plus("Failed to raise privileges");
1887
_exit(EX_NOPERM);
1888
}
1889
/* Set group */
1890
errno = 0;
1891
ret = setgid(0);
1892
if(ret == -1){
1893
perror_plus("setgid");
1894
_exit(EX_NOPERM);
1895
}
1896
/* Reset supplementary groups */
1897
errno = 0;
1898
ret = setgroups(0, NULL);
1899
if(ret == -1){
1900
perror_plus("setgroups");
1901
_exit(EX_NOPERM);
1902
}
1903
ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);
1904
if(ret == -1){
1905
perror_plus("setenv");
1906
_exit(EX_OSERR);
1907
}
1908
ret = setenv("DEVICE", interface, 1);
1909
if(ret == -1){
1910
perror_plus("setenv");
1911
_exit(EX_OSERR);
1912
}
1913
ret = setenv("VERBOSITY", debug ? "1" : "0", 1);
1914
if(ret == -1){
1915
perror_plus("setenv");
1916
_exit(EX_OSERR);
1917
}
1918
ret = setenv("MODE", mode, 1);
1919
if(ret == -1){
1920
perror_plus("setenv");
1921
_exit(EX_OSERR);
1922
}
1923
char *delaystring;
1924
ret = asprintf(&delaystring, "%f", (double)delay);
1925
if(ret == -1){
1926
perror_plus("asprintf");
1927
_exit(EX_OSERR);
1928
}
1929
ret = setenv("DELAY", delaystring, 1);
1930
if(ret == -1){
1931
free(delaystring);
1932
perror_plus("setenv");
1933
_exit(EX_OSERR);
1934
}
1935
free(delaystring);
1936
if(connect_to != NULL){
1937
ret = setenv("CONNECT", connect_to, 1);
1938
if(ret == -1){
1939
perror_plus("setenv");
1940
_exit(EX_OSERR);
1941
}
1942
}
1943
int hook_fd = (int)TEMP_FAILURE_RETRY(openat(hookdir_fd,
1944
direntry->d_name,
1945
O_RDONLY));
1946
if(hook_fd == -1){
1947
perror_plus("openat");
1948
_exit(EXIT_FAILURE);
1949
}
1950
if((int)TEMP_FAILURE_RETRY(close(hookdir_fd)) == -1){
1951
perror_plus("close");
1952
_exit(EXIT_FAILURE);
1953
}
1954
ret = dup2(devnull, STDIN_FILENO);
1955
if(ret == -1){
1956
perror_plus("dup2(devnull, STDIN_FILENO)");
1957
_exit(EX_OSERR);
1958
}
1959
ret = (int)TEMP_FAILURE_RETRY(close(devnull));
1960
if(ret == -1){
1961
perror_plus("close");
1962
_exit(EX_OSERR);
1963
}
1964
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
1965
if(ret == -1){
1966
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
1967
_exit(EX_OSERR);
1968
}
1969
if(fexecve(hook_fd, (char *const []){ direntry->d_name, NULL },
1970
environ) == -1){
1971
perror_plus("fexecve");
1972
_exit(EXIT_FAILURE);
1973
}
1974
} else {
1975
if(hook_pid == -1){
1976
perror_plus("fork");
1977
free(direntry);
1978
continue;
1979
}
1980
int status;
1981
if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){
1982
perror_plus("waitpid");
1983
free(direntry);
1984
continue;
1985
}
1986
if(WIFEXITED(status)){
1987
if(WEXITSTATUS(status) != 0){
1988
fprintf_plus(stderr, "Warning: network hook \"%s\" exited"
1989
" with status %d\n", direntry->d_name,
1990
WEXITSTATUS(status));
1991
free(direntry);
1992
continue;
1993
}
1994
} else if(WIFSIGNALED(status)){
1995
fprintf_plus(stderr, "Warning: network hook \"%s\" died by"
1996
" signal %d\n", direntry->d_name,
1997
WTERMSIG(status));
1998
free(direntry);
1999
continue;
2000
} else {
2001
fprintf_plus(stderr, "Warning: network hook \"%s\""
2002
" crashed\n", direntry->d_name);
2003
free(direntry);
2004
continue;
2005
}
2006
}
2007
if(debug){
2008
fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",
2009
direntry->d_name);
2010
}
2011
free(direntry);
2012
}
2013
free(direntries);
2014
if((int)TEMP_FAILURE_RETRY(close(hookdir_fd)) == -1){
2015
perror_plus("close");
2016
} else {
2017
hookdir_fd = -1;
2018
}
2019
close(devnull);
2020
}
2021
2022
__attribute__((nonnull, warn_unused_result))
2023
error_t bring_up_interface(const char *const interface,
2024
const float delay){
2025
error_t old_errno = errno;
2026
int ret;
2027
struct ifreq network;
2028
unsigned int if_index = if_nametoindex(interface);
2029
if(if_index == 0){
2030
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
2031
errno = old_errno;
2032
return ENXIO;
2033
}
2034
2035
if(quit_now){
2036
errno = old_errno;
2037
return EINTR;
2038
}
2039
2040
if(not interface_is_up(interface)){
2041
error_t ret_errno = 0, ioctl_errno = 0;
2042
if(not get_flags(interface, &network)){
2043
ret_errno = errno;
2044
fprintf_plus(stderr, "Failed to get flags for interface "
2045
"\"%s\"\n", interface);
2046
errno = old_errno;
2047
return ret_errno;
2048
}
2049
network.ifr_flags |= IFF_UP; /* set flag */
2050
2051
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
2052
if(sd == -1){
2053
ret_errno = errno;
2054
perror_plus("socket");
2055
errno = old_errno;
2056
return ret_errno;
2057
}
2058
2059
if(quit_now){
2060
ret = (int)TEMP_FAILURE_RETRY(close(sd));
2061
if(ret == -1){
2062
perror_plus("close");
2063
}
2064
errno = old_errno;
2065
return EINTR;
2066
}
2067
2068
if(debug){
2069
fprintf_plus(stderr, "Bringing up interface \"%s\"\n",
2070
interface);
2071
}
2072
2073
/* Raise privileges */
2074
ret_errno = raise_privileges();
2075
if(ret_errno != 0){
2076
errno = ret_errno;
2077
perror_plus("Failed to raise privileges");
2078
}
2079
2080
#ifdef __linux__
2081
int ret_linux;
2082
bool restore_loglevel = false;
2083
if(ret_errno == 0){
2084
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
2085
messages about the network interface to mess up the prompt */
2086
ret_linux = klogctl(8, NULL, 5);
2087
if(ret_linux == -1){
2088
perror_plus("klogctl");
2089
} else {
2090
restore_loglevel = true;
2091
}
2092
}
2093
#endif /* __linux__ */
2094
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
2095
ioctl_errno = errno;
2096
#ifdef __linux__
2097
if(restore_loglevel){
2098
ret_linux = klogctl(7, NULL, 0);
2099
if(ret_linux == -1){
2100
perror_plus("klogctl");
2101
}
2102
}
2103
#endif /* __linux__ */
2104
2105
/* If raise_privileges() succeeded above */
2106
if(ret_errno == 0){
2107
/* Lower privileges */
2108
ret_errno = lower_privileges();
2109
if(ret_errno != 0){
2110
errno = ret_errno;
2111
perror_plus("Failed to lower privileges");
2112
}
2113
}
2114
2115
/* Close the socket */
2116
ret = (int)TEMP_FAILURE_RETRY(close(sd));
2117
if(ret == -1){
2118
perror_plus("close");
2119
}
2120
2121
if(ret_setflags == -1){
2122
errno = ioctl_errno;
2123
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
2124
errno = old_errno;
2125
return ioctl_errno;
2126
}
2127
} else if(debug){
2128
fprintf_plus(stderr, "Interface \"%s\" is already up; good\n",
2129
interface);
2130
}
2131
2132
/* Sleep checking until interface is running.
2133
Check every 0.25s, up to total time of delay */
2134
for(int i=0; i < delay * 4; i++){
2135
if(interface_is_running(interface)){
2136
break;
2137
}
2138
struct timespec sleeptime = { .tv_nsec = 250000000 };
2139
ret = nanosleep(&sleeptime, NULL);
2140
if(ret == -1 and errno != EINTR){
2141
perror_plus("nanosleep");
2142
}
2143
}
2144
2145
errno = old_errno;
2146
return 0;
2147
}
2148
2149
__attribute__((nonnull, warn_unused_result))
2150
error_t take_down_interface(const char *const interface){
2151
error_t old_errno = errno;
2152
struct ifreq network;
2153
unsigned int if_index = if_nametoindex(interface);
2154
if(if_index == 0){
2155
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
2156
errno = old_errno;
2157
return ENXIO;
2158
}
2159
if(interface_is_up(interface)){
2160
error_t ret_errno = 0, ioctl_errno = 0;
2161
if(not get_flags(interface, &network) and debug){
2162
ret_errno = errno;
2163
fprintf_plus(stderr, "Failed to get flags for interface "
2164
"\"%s\"\n", interface);
2165
errno = old_errno;
2166
return ret_errno;
2167
}
2168
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
2169
2170
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
2171
if(sd == -1){
2172
ret_errno = errno;
2173
perror_plus("socket");
2174
errno = old_errno;
2175
return ret_errno;
2176
}
2177
2178
if(debug){
2179
fprintf_plus(stderr, "Taking down interface \"%s\"\n",
2180
interface);
2181
}
2182
2183
/* Raise privileges */
2184
ret_errno = raise_privileges();
2185
if(ret_errno != 0){
2186
errno = ret_errno;
2187
perror_plus("Failed to raise privileges");
2188
}
2189
2190
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
2191
ioctl_errno = errno;
2192
2193
/* If raise_privileges() succeeded above */
2194
if(ret_errno == 0){
2195
/* Lower privileges */
2196
ret_errno = lower_privileges();
2197
if(ret_errno != 0){
2198
errno = ret_errno;
2199
perror_plus("Failed to lower privileges");
2200
}
2201
}
2202
2203
/* Close the socket */
2204
int ret = (int)TEMP_FAILURE_RETRY(close(sd));
2205
if(ret == -1){
2206
perror_plus("close");
2207
}
2208
2209
if(ret_setflags == -1){
2210
errno = ioctl_errno;
2211
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
2212
errno = old_errno;
2213
return ioctl_errno;
2214
}
2215
} else if(debug){
2216
fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",
2217
interface);
2218
}
2219
2220
errno = old_errno;
2221
return 0;
2222
}
2223
2224
int main(int argc, char *argv[]){
2225
mandos_context mc = { .server = NULL, .dh_bits = 0,
2226
.priority = "SECURE256:!CTYPE-X.509:"
2227
"+CTYPE-OPENPGP:!RSA", .current_server = NULL,
2228
.interfaces = NULL, .interfaces_size = 0 };
2229
AvahiSServiceBrowser *sb = NULL;
2230
error_t ret_errno;
2231
int ret;
2232
intmax_t tmpmax;
2233
char *tmp;
2234
int exitcode = EXIT_SUCCESS;
2235
char *interfaces_to_take_down = NULL;
2236
size_t interfaces_to_take_down_size = 0;
2237
char run_tempdir[] = "/run/tmp/mandosXXXXXX";
2238
char old_tempdir[] = "/tmp/mandosXXXXXX";
2239
char *tempdir = NULL;
2240
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
2241
const char *seckey = PATHDIR "/" SECKEY;
2242
const char *pubkey = PATHDIR "/" PUBKEY;
2243
char *interfaces_hooks = NULL;
2244
2245
bool gnutls_initialized = false;
2246
bool gpgme_initialized = false;
2247
float delay = 2.5f;
2248
double retry_interval = 10; /* 10s between trying a server and
2249
retrying the same server again */
2250
2251
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
2252
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
2253
2254
uid = getuid();
2255
gid = getgid();
2256
2257
/* Lower any group privileges we might have, just to be safe */
2258
errno = 0;
2259
ret = setgid(gid);
2260
if(ret == -1){
2261
perror_plus("setgid");
2262
}
2263
2264
/* Lower user privileges (temporarily) */
2265
errno = 0;
2266
ret = seteuid(uid);
2267
if(ret == -1){
2268
perror_plus("seteuid");
2269
}
2270
2271
if(quit_now){
2272
goto end;
2273
}
2274
2275
{
2276
struct argp_option options[] = {
2277
{ .name = "debug", .key = 128,
2278
.doc = "Debug mode", .group = 3 },
2279
{ .name = "connect", .key = 'c',
2280
.arg = "ADDRESS:PORT",
2281
.doc = "Connect directly to a specific Mandos server",
2282
.group = 1 },
2283
{ .name = "interface", .key = 'i',
2284
.arg = "NAME",
2285
.doc = "Network interface that will be used to search for"
2286
" Mandos servers",
2287
.group = 1 },
2288
{ .name = "seckey", .key = 's',
2289
.arg = "FILE",
2290
.doc = "OpenPGP secret key file base name",
2291
.group = 1 },
2292
{ .name = "pubkey", .key = 'p',
2293
.arg = "FILE",
2294
.doc = "OpenPGP public key file base name",
2295
.group = 2 },
2296
{ .name = "dh-bits", .key = 129,
2297
.arg = "BITS",
2298
.doc = "Bit length of the prime number used in the"
2299
" Diffie-Hellman key exchange",
2300
.group = 2 },
2301
{ .name = "priority", .key = 130,
2302
.arg = "STRING",
2303
.doc = "GnuTLS priority string for the TLS handshake",
2304
.group = 1 },
2305
{ .name = "delay", .key = 131,
2306
.arg = "SECONDS",
2307
.doc = "Maximum delay to wait for interface startup",
2308
.group = 2 },
2309
{ .name = "retry", .key = 132,
2310
.arg = "SECONDS",
2311
.doc = "Retry interval used when denied by the Mandos server",
2312
.group = 2 },
2313
{ .name = "network-hook-dir", .key = 133,
2314
.arg = "DIR",
2315
.doc = "Directory where network hooks are located",
2316
.group = 2 },
2317
/*
2318
* These reproduce what we would get without ARGP_NO_HELP
2319
*/
2320
{ .name = "help", .key = '?',
2321
.doc = "Give this help list", .group = -1 },
2322
{ .name = "usage", .key = -3,
2323
.doc = "Give a short usage message", .group = -1 },
2324
{ .name = "version", .key = 'V',
2325
.doc = "Print program version", .group = -1 },
2326
{ .name = NULL }
2327
};
2328
2329
error_t parse_opt(int key, char *arg,
2330
struct argp_state *state){
2331
errno = 0;
2332
switch(key){
2333
case 128: /* --debug */
2334
debug = true;
2335
break;
2336
case 'c': /* --connect */
2337
connect_to = arg;
2338
break;
2339
case 'i': /* --interface */
2340
ret_errno = argz_add_sep(&mc.interfaces, &mc.interfaces_size,
2341
arg, (int)',');
2342
if(ret_errno != 0){
2343
argp_error(state, "%s", strerror(ret_errno));
2344
}
2345
break;
2346
case 's': /* --seckey */
2347
seckey = arg;
2348
break;
2349
case 'p': /* --pubkey */
2350
pubkey = arg;
2351
break;
2352
case 129: /* --dh-bits */
2353
errno = 0;
2354
tmpmax = strtoimax(arg, &tmp, 10);
2355
if(errno != 0 or tmp == arg or *tmp != '\0'
2356
or tmpmax != (typeof(mc.dh_bits))tmpmax){
2357
argp_error(state, "Bad number of DH bits");
2358
}
2359
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
2360
break;
2361
case 130: /* --priority */
2362
mc.priority = arg;
2363
break;
2364
case 131: /* --delay */
2365
errno = 0;
2366
delay = strtof(arg, &tmp);
2367
if(errno != 0 or tmp == arg or *tmp != '\0'){
2368
argp_error(state, "Bad delay");
2369
}
2370
case 132: /* --retry */
2371
errno = 0;
2372
retry_interval = strtod(arg, &tmp);
2373
if(errno != 0 or tmp == arg or *tmp != '\0'
2374
or (retry_interval * 1000) > INT_MAX
2375
or retry_interval < 0){
2376
argp_error(state, "Bad retry interval");
2377
}
2378
break;
2379
case 133: /* --network-hook-dir */
2380
hookdir = arg;
2381
break;
2382
/*
2383
* These reproduce what we would get without ARGP_NO_HELP
2384
*/
2385
case '?': /* --help */
2386
argp_state_help(state, state->out_stream,
2387
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
2388
& ~(unsigned int)ARGP_HELP_EXIT_OK);
2389
case -3: /* --usage */
2390
argp_state_help(state, state->out_stream,
2391
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
2392
case 'V': /* --version */
2393
fprintf_plus(state->out_stream, "%s\n", argp_program_version);
2394
exit(argp_err_exit_status);
2395
break;
2396
default:
2397
return ARGP_ERR_UNKNOWN;
2398
}
2399
return errno;
2400
}
2401
2402
struct argp argp = { .options = options, .parser = parse_opt,
2403
.args_doc = "",
2404
.doc = "Mandos client -- Get and decrypt"
2405
" passwords from a Mandos server" };
2406
ret = argp_parse(&argp, argc, argv,
2407
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
2408
switch(ret){
2409
case 0:
2410
break;
2411
case ENOMEM:
2412
default:
2413
errno = ret;
2414
perror_plus("argp_parse");
2415
exitcode = EX_OSERR;
2416
goto end;
2417
case EINVAL:
2418
exitcode = EX_USAGE;
2419
goto end;
2420
}
2421
}
2422
2423
{
2424
/* Work around Debian bug #633582:
2425
<http://bugs.debian.org/633582> */
2426
2427
/* Re-raise privileges */
2428
ret_errno = raise_privileges();
2429
if(ret_errno != 0){
2430
errno = ret_errno;
2431
perror_plus("Failed to raise privileges");
2432
} else {
2433
struct stat st;
2434
2435
if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){
2436
int seckey_fd = open(seckey, O_RDONLY);
2437
if(seckey_fd == -1){
2438
perror_plus("open");
2439
} else {
2440
ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));
2441
if(ret == -1){
2442
perror_plus("fstat");
2443
} else {
2444
if(S_ISREG(st.st_mode)
2445
and st.st_uid == 0 and st.st_gid == 0){
2446
ret = fchown(seckey_fd, uid, gid);
2447
if(ret == -1){
2448
perror_plus("fchown");
2449
}
2450
}
2451
}
2452
TEMP_FAILURE_RETRY(close(seckey_fd));
2453
}
2454
}
2455
2456
if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){
2457
int pubkey_fd = open(pubkey, O_RDONLY);
2458
if(pubkey_fd == -1){
2459
perror_plus("open");
2460
} else {
2461
ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));
2462
if(ret == -1){
2463
perror_plus("fstat");
2464
} else {
2465
if(S_ISREG(st.st_mode)
2466
and st.st_uid == 0 and st.st_gid == 0){
2467
ret = fchown(pubkey_fd, uid, gid);
2468
if(ret == -1){
2469
perror_plus("fchown");
2470
}
2471
}
2472
}
2473
TEMP_FAILURE_RETRY(close(pubkey_fd));
2474
}
2475
}
2476
2477
/* Lower privileges */
2478
ret_errno = lower_privileges();
2479
if(ret_errno != 0){
2480
errno = ret_errno;
2481
perror_plus("Failed to lower privileges");
2482
}
2483
}
2484
}
2485
2486
/* Remove invalid interface names (except "none") */
2487
{
2488
char *interface = NULL;
2489
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2490
interface))){
2491
if(strcmp(interface, "none") != 0
2492
and if_nametoindex(interface) == 0){
2493
if(interface[0] != '\0'){
2494
fprintf_plus(stderr, "Not using nonexisting interface"
2495
" \"%s\"\n", interface);
2496
}
2497
argz_delete(&mc.interfaces, &mc.interfaces_size, interface);
2498
interface = NULL;
2499
}
2500
}
2501
}
2502
2503
/* Run network hooks */
2504
{
2505
if(mc.interfaces != NULL){
2506
interfaces_hooks = malloc(mc.interfaces_size);
2507
if(interfaces_hooks == NULL){
2508
perror_plus("malloc");
2509
goto end;
2510
}
2511
memcpy(interfaces_hooks, mc.interfaces, mc.interfaces_size);
2512
argz_stringify(interfaces_hooks, mc.interfaces_size, (int)',');
2513
}
2514
run_network_hooks("start", interfaces_hooks != NULL ?
2515
interfaces_hooks : "", delay);
2516
}
2517
2518
if(not debug){
2519
avahi_set_log_function(empty_log);
2520
}
2521
2522
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
2523
from the signal handler */
2524
/* Initialize the pseudo-RNG for Avahi */
2525
srand((unsigned int) time(NULL));
2526
simple_poll = avahi_simple_poll_new();
2527
if(simple_poll == NULL){
2528
fprintf_plus(stderr,
2529
"Avahi: Failed to create simple poll object.\n");
2530
exitcode = EX_UNAVAILABLE;
2531
goto end;
2532
}
2533
2534
sigemptyset(&sigterm_action.sa_mask);
2535
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
2536
if(ret == -1){
2537
perror_plus("sigaddset");
2538
exitcode = EX_OSERR;
2539
goto end;
2540
}
2541
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
2542
if(ret == -1){
2543
perror_plus("sigaddset");
2544
exitcode = EX_OSERR;
2545
goto end;
2546
}
2547
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
2548
if(ret == -1){
2549
perror_plus("sigaddset");
2550
exitcode = EX_OSERR;
2551
goto end;
2552
}
2553
/* Need to check if the handler is SIG_IGN before handling:
2554
| [[info:libc:Initial Signal Actions]] |
2555
| [[info:libc:Basic Signal Handling]] |
2556
*/
2557
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
2558
if(ret == -1){
2559
perror_plus("sigaction");
2560
return EX_OSERR;
2561
}
2562
if(old_sigterm_action.sa_handler != SIG_IGN){
2563
ret = sigaction(SIGINT, &sigterm_action, NULL);
2564
if(ret == -1){
2565
perror_plus("sigaction");
2566
exitcode = EX_OSERR;
2567
goto end;
2568
}
2569
}
2570
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
2571
if(ret == -1){
2572
perror_plus("sigaction");
2573
return EX_OSERR;
2574
}
2575
if(old_sigterm_action.sa_handler != SIG_IGN){
2576
ret = sigaction(SIGHUP, &sigterm_action, NULL);
2577
if(ret == -1){
2578
perror_plus("sigaction");
2579
exitcode = EX_OSERR;
2580
goto end;
2581
}
2582
}
2583
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
2584
if(ret == -1){
2585
perror_plus("sigaction");
2586
return EX_OSERR;
2587
}
2588
if(old_sigterm_action.sa_handler != SIG_IGN){
2589
ret = sigaction(SIGTERM, &sigterm_action, NULL);
2590
if(ret == -1){
2591
perror_plus("sigaction");
2592
exitcode = EX_OSERR;
2593
goto end;
2594
}
2595
}
2596
2597
/* If no interfaces were specified, make a list */
2598
if(mc.interfaces == NULL){
2599
struct dirent **direntries = NULL;
2600
/* Look for any good interfaces */
2601
ret = scandir(sys_class_net, &direntries, good_interface,
2602
alphasort);
2603
if(ret >= 1){
2604
/* Add all found interfaces to interfaces list */
2605
for(int i = 0; i < ret; ++i){
2606
ret_errno = argz_add(&mc.interfaces, &mc.interfaces_size,
2607
direntries[i]->d_name);
2608
if(ret_errno != 0){
2609
errno = ret_errno;
2610
perror_plus("argz_add");
2611
free(direntries[i]);
2612
continue;
2613
}
2614
if(debug){
2615
fprintf_plus(stderr, "Will use interface \"%s\"\n",
2616
direntries[i]->d_name);
2617
}
2618
free(direntries[i]);
2619
}
2620
free(direntries);
2621
} else {
2622
if(ret == 0){
2623
free(direntries);
2624
}
2625
fprintf_plus(stderr, "Could not find a network interface\n");
2626
exitcode = EXIT_FAILURE;
2627
goto end;
2628
}
2629
}
2630
2631
/* Bring up interfaces which are down, and remove any "none"s */
2632
{
2633
char *interface = NULL;
2634
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2635
interface))){
2636
/* If interface name is "none", stop bringing up interfaces.
2637
Also remove all instances of "none" from the list */
2638
if(strcmp(interface, "none") == 0){
2639
argz_delete(&mc.interfaces, &mc.interfaces_size,
2640
interface);
2641
interface = NULL;
2642
while((interface = argz_next(mc.interfaces,
2643
mc.interfaces_size, interface))){
2644
if(strcmp(interface, "none") == 0){
2645
argz_delete(&mc.interfaces, &mc.interfaces_size,
2646
interface);
2647
interface = NULL;
2648
}
2649
}
2650
break;
2651
}
2652
bool interface_was_up = interface_is_up(interface);
2653
errno = bring_up_interface(interface, delay);
2654
if(not interface_was_up){
2655
if(errno != 0){
2656
perror_plus("Failed to bring up interface");
2657
} else {
2658
errno = argz_add(&interfaces_to_take_down,
2659
&interfaces_to_take_down_size,
2660
interface);
2661
if(errno != 0){
2662
perror_plus("argz_add");
2663
}
2664
}
2665
}
2666
}
2667
if(debug and (interfaces_to_take_down == NULL)){
2668
fprintf_plus(stderr, "No interfaces were brought up\n");
2669
}
2670
}
2671
2672
/* If we only got one interface, explicitly use only that one */
2673
if(argz_count(mc.interfaces, mc.interfaces_size) == 1){
2674
if(debug){
2675
fprintf_plus(stderr, "Using only interface \"%s\"\n",
2676
mc.interfaces);
2677
}
2678
if_index = (AvahiIfIndex)if_nametoindex(mc.interfaces);
2679
}
2680
2681
if(quit_now){
2682
goto end;
2683
}
2684
2685
ret = init_gnutls_global(pubkey, seckey, &mc);
2686
if(ret == -1){
2687
fprintf_plus(stderr, "init_gnutls_global failed\n");
2688
exitcode = EX_UNAVAILABLE;
2689
goto end;
2690
} else {
2691
gnutls_initialized = true;
2692
}
2693
2694
if(quit_now){
2695
goto end;
2696
}
2697
2698
/* Try /run/tmp before /tmp */
2699
tempdir = mkdtemp(run_tempdir);
2700
if(tempdir == NULL and errno == ENOENT){
2701
if(debug){
2702
fprintf_plus(stderr, "Tempdir %s did not work, trying %s\n",
2703
run_tempdir, old_tempdir);
2704
}
2705
tempdir = mkdtemp(old_tempdir);
2706
}
2707
if(tempdir == NULL){
2708
perror_plus("mkdtemp");
2709
goto end;
2710
}
2711
2712
if(quit_now){
2713
goto end;
2714
}
2715
2716
if(not init_gpgme(pubkey, seckey, tempdir, &mc)){
2717
fprintf_plus(stderr, "init_gpgme failed\n");
2718
exitcode = EX_UNAVAILABLE;
2719
goto end;
2720
} else {
2721
gpgme_initialized = true;
2722
}
2723
2724
if(quit_now){
2725
goto end;
2726
}
2727
2728
if(connect_to != NULL){
2729
/* Connect directly, do not use Zeroconf */
2730
/* (Mainly meant for debugging) */
2731
char *address = strrchr(connect_to, ':');
2732
2733
if(address == NULL){
2734
fprintf_plus(stderr, "No colon in address\n");
2735
exitcode = EX_USAGE;
2736
goto end;
2737
}
2738
2739
if(quit_now){
2740
goto end;
2741
}
2742
2743
in_port_t port;
2744
errno = 0;
2745
tmpmax = strtoimax(address+1, &tmp, 10);
2746
if(errno != 0 or tmp == address+1 or *tmp != '\0'
2747
or tmpmax != (in_port_t)tmpmax){
2748
fprintf_plus(stderr, "Bad port number\n");
2749
exitcode = EX_USAGE;
2750
goto end;
2751
}
2752
2753
if(quit_now){
2754
goto end;
2755
}
2756
2757
port = (in_port_t)tmpmax;
2758
*address = '\0';
2759
/* Colon in address indicates IPv6 */
2760
int af;
2761
if(strchr(connect_to, ':') != NULL){
2762
af = AF_INET6;
2763
/* Accept [] around IPv6 address - see RFC 5952 */
2764
if(connect_to[0] == '[' and address[-1] == ']')
2765
{
2766
connect_to++;
2767
address[-1] = '\0';
2768
}
2769
} else {
2770
af = AF_INET;
2771
}
2772
address = connect_to;
2773
2774
if(quit_now){
2775
goto end;
2776
}
2777
2778
while(not quit_now){
2779
ret = start_mandos_communication(address, port, if_index, af,
2780
&mc);
2781
if(quit_now or ret == 0){
2782
break;
2783
}
2784
if(debug){
2785
fprintf_plus(stderr, "Retrying in %d seconds\n",
2786
(int)retry_interval);
2787
}
2788
sleep((unsigned int)retry_interval);
2789
}
2790
2791
if(not quit_now){
2792
exitcode = EXIT_SUCCESS;
2793
}
2794
2795
goto end;
2796
}
2797
2798
if(quit_now){
2799
goto end;
2800
}
2801
2802
{
2803
AvahiServerConfig config;
2804
/* Do not publish any local Zeroconf records */
2805
avahi_server_config_init(&config);
2806
config.publish_hinfo = 0;
2807
config.publish_addresses = 0;
2808
config.publish_workstation = 0;
2809
config.publish_domain = 0;
2810
2811
/* Allocate a new server */
2812
mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),
2813
&config, NULL, NULL, &ret_errno);
2814
2815
/* Free the Avahi configuration data */
2816
avahi_server_config_free(&config);
2817
}
2818
2819
/* Check if creating the Avahi server object succeeded */
2820
if(mc.server == NULL){
2821
fprintf_plus(stderr, "Failed to create Avahi server: %s\n",
2822
avahi_strerror(ret_errno));
2823
exitcode = EX_UNAVAILABLE;
2824
goto end;
2825
}
2826
2827
if(quit_now){
2828
goto end;
2829
}
2830
2831
/* Create the Avahi service browser */
2832
sb = avahi_s_service_browser_new(mc.server, if_index,
2833
AVAHI_PROTO_UNSPEC, "_mandos._tcp",
2834
NULL, 0, browse_callback,
2835
(void *)&mc);
2836
if(sb == NULL){
2837
fprintf_plus(stderr, "Failed to create service browser: %s\n",
2838
avahi_strerror(avahi_server_errno(mc.server)));
2839
exitcode = EX_UNAVAILABLE;
2840
goto end;
2841
}
2842
2843
if(quit_now){
2844
goto end;
2845
}
2846
2847
/* Run the main loop */
2848
2849
if(debug){
2850
fprintf_plus(stderr, "Starting Avahi loop search\n");
2851
}
2852
2853
ret = avahi_loop_with_timeout(simple_poll,
2854
(int)(retry_interval * 1000), &mc);
2855
if(debug){
2856
fprintf_plus(stderr, "avahi_loop_with_timeout exited %s\n",
2857
(ret == 0) ? "successfully" : "with error");
2858
}
2859
2860
end:
2861
2862
if(debug){
2863
fprintf_plus(stderr, "%s exiting\n", argv[0]);
2864
}
2865
2866
/* Cleanup things */
2867
free(mc.interfaces);
2868
2869
if(sb != NULL)
2870
avahi_s_service_browser_free(sb);
2871
2872
if(mc.server != NULL)
2873
avahi_server_free(mc.server);
2874
2875
if(simple_poll != NULL)
2876
avahi_simple_poll_free(simple_poll);
2877
2878
if(gnutls_initialized){
2879
gnutls_certificate_free_credentials(mc.cred);
2880
gnutls_global_deinit();
2881
gnutls_dh_params_deinit(mc.dh_params);
2882
}
2883
2884
if(gpgme_initialized){
2885
gpgme_release(mc.ctx);
2886
}
2887
2888
/* Cleans up the circular linked list of Mandos servers the client
2889
has seen */
2890
if(mc.current_server != NULL){
2891
mc.current_server->prev->next = NULL;
2892
while(mc.current_server != NULL){
2893
server *next = mc.current_server->next;
2894
#ifdef __GNUC__
2895
#pragma GCC diagnostic push
2896
#pragma GCC diagnostic ignored "-Wcast-qual"
2897
#endif
2898
free((char *)(mc.current_server->ip));
2899
#ifdef __GNUC__
2900
#pragma GCC diagnostic pop
2901
#endif
2902
free(mc.current_server);
2903
mc.current_server = next;
2904
}
2905
}
2906
2907
/* Re-raise privileges */
2908
{
2909
ret_errno = raise_privileges();
2910
if(ret_errno != 0){
2911
errno = ret_errno;
2912
perror_plus("Failed to raise privileges");
2913
} else {
2914
2915
/* Run network hooks */
2916
run_network_hooks("stop", interfaces_hooks != NULL ?
2917
interfaces_hooks : "", delay);
2918
2919
/* Take down the network interfaces which were brought up */
2920
{
2921
char *interface = NULL;
2922
while((interface=argz_next(interfaces_to_take_down,
2923
interfaces_to_take_down_size,
2924
interface))){
2925
ret_errno = take_down_interface(interface);
2926
if(ret_errno != 0){
2927
errno = ret_errno;
2928
perror_plus("Failed to take down interface");
2929
}
2930
}
2931
if(debug and (interfaces_to_take_down == NULL)){
2932
fprintf_plus(stderr, "No interfaces needed to be taken"
2933
" down\n");
2934
}
2935
}
2936
}
2937
2938
ret_errno = lower_privileges_permanently();
2939
if(ret_errno != 0){
2940
errno = ret_errno;
2941
perror_plus("Failed to lower privileges permanently");
2942
}
2943
}
2944
2945
free(interfaces_to_take_down);
2946
free(interfaces_hooks);
2947
2948
/* Removes the GPGME temp directory and all files inside */
2949
if(tempdir != NULL){
2950
struct dirent **direntries = NULL;
2951
int tempdir_fd = (int)TEMP_FAILURE_RETRY(open(tempdir, O_RDONLY
2952
| O_NOFOLLOW
2953
| O_DIRECTORY
2954
| O_PATH));
2955
if(tempdir_fd == -1){
2956
perror_plus("open");
2957
} else {
2958
#ifdef __GLIBC__
2959
#if __GLIBC_PREREQ(2, 15)
2960
int numentries = scandirat(tempdir_fd, ".", &direntries,
2961
notdotentries, alphasort);
2962
#else /* not __GLIBC_PREREQ(2, 15) */
2963
int numentries = scandir(tempdir, &direntries, notdotentries,
2964
alphasort);
2965
#endif /* not __GLIBC_PREREQ(2, 15) */
2966
#else /* not __GLIBC__ */
2967
int numentries = scandir(tempdir, &direntries, notdotentries,
2968
alphasort);
2969
#endif /* not __GLIBC__ */
2970
if(numentries >= 0){
2971
for(int i = 0; i < numentries; i++){
2972
ret = unlinkat(tempdir_fd, direntries[i]->d_name, 0);
2973
if(ret == -1){
2974
fprintf_plus(stderr, "unlinkat(open(\"%s\", O_RDONLY),"
2975
" \"%s\", 0): %s\n", tempdir,
2976
direntries[i]->d_name, strerror(errno));
2977
}
2978
free(direntries[i]);
2979
}
2980
2981
/* need to clean even if 0 because man page doesn't specify */
2982
free(direntries);
2983
if(numentries == -1){
2984
perror_plus("scandir");
2985
}
2986
ret = rmdir(tempdir);
2987
if(ret == -1 and errno != ENOENT){
2988
perror_plus("rmdir");
2989
}
2990
}
2991
TEMP_FAILURE_RETRY(close(tempdir_fd));
2992
}
2993
}
2994
2995
if(quit_now){
2996
sigemptyset(&old_sigterm_action.sa_mask);
2997
old_sigterm_action.sa_handler = SIG_DFL;
2998
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
2999
&old_sigterm_action,
3000
NULL));
3001
if(ret == -1){
3002
perror_plus("sigaction");
3003
}
3004
do {
3005
ret = raise(signal_received);
3006
} while(ret != 0 and errno == EINTR);
3007
if(ret != 0){
3008
perror_plus("raise");
3009
abort();
3010
}
3011
TEMP_FAILURE_RETRY(pause());
3012
}
3013
3014
return exitcode;
3015
}
Loggerhead is a web-based interface for Breezy
Version: 2.0.2.dev0