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- Committer: Björn Påhlsson
- Date: 2007-10-20 21:38:25 UTC
- Revision ID: belorn@tower-20071020213825-abf6f0d1c33ee961
First working version with: IPv6, GnuTLS, X.509 certificates, DN
retrieval.
retrieval.
- files added:
- bad-ca.pem
- files removed:
- .bzr-builddeb
- debian
- debian/po
- debian/source
- debian/upstream
- network-hooks.d
- plugins.d
- 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 © 2008-2014 Teddy Hogeborn
13
* Copyright © 2008-2014 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
return false;
238
}
239
ret = clock_gettime(CLOCK_MONOTONIC, &(new_server->last_seen));
240
if(ret == -1){
241
perror_plus("clock_gettime");
242
return false;
243
}
244
/* Special case of first server */
245
if(*current_server == NULL){
246
new_server->next = new_server;
247
new_server->prev = new_server;
248
*current_server = new_server;
249
} else {
250
/* Place the new server last in the list */
251
new_server->next = *current_server;
252
new_server->prev = (*current_server)->prev;
253
new_server->prev->next = new_server;
254
(*current_server)->prev = new_server;
255
}
256
return true;
257
}
258
259
/*
260
* Initialize GPGME.
261
*/
262
__attribute__((nonnull, warn_unused_result))
263
static bool init_gpgme(const char * const seckey,
264
const char * const pubkey,
265
const char * const tempdir,
266
mandos_context *mc){
267
gpgme_error_t rc;
268
gpgme_engine_info_t engine_info;
269
270
/*
271
* Helper function to insert pub and seckey to the engine keyring.
272
*/
273
bool import_key(const char * const filename){
274
int ret;
275
int fd;
276
gpgme_data_t pgp_data;
277
278
fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
279
if(fd == -1){
280
perror_plus("open");
281
return false;
282
}
283
284
rc = gpgme_data_new_from_fd(&pgp_data, fd);
285
if(rc != GPG_ERR_NO_ERROR){
286
fprintf_plus(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
287
gpgme_strsource(rc), gpgme_strerror(rc));
288
return false;
289
}
290
291
rc = gpgme_op_import(mc->ctx, pgp_data);
292
if(rc != GPG_ERR_NO_ERROR){
293
fprintf_plus(stderr, "bad gpgme_op_import: %s: %s\n",
294
gpgme_strsource(rc), gpgme_strerror(rc));
295
return false;
296
}
297
298
ret = (int)TEMP_FAILURE_RETRY(close(fd));
299
if(ret == -1){
300
perror_plus("close");
301
}
302
gpgme_data_release(pgp_data);
303
return true;
304
}
305
306
if(debug){
307
fprintf_plus(stderr, "Initializing GPGME\n");
308
}
309
310
/* Init GPGME */
311
gpgme_check_version(NULL);
312
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
313
if(rc != GPG_ERR_NO_ERROR){
314
fprintf_plus(stderr, "bad gpgme_engine_check_version: %s: %s\n",
315
gpgme_strsource(rc), gpgme_strerror(rc));
316
return false;
317
}
318
319
/* Set GPGME home directory for the OpenPGP engine only */
320
rc = gpgme_get_engine_info(&engine_info);
321
if(rc != GPG_ERR_NO_ERROR){
322
fprintf_plus(stderr, "bad gpgme_get_engine_info: %s: %s\n",
323
gpgme_strsource(rc), gpgme_strerror(rc));
324
return false;
325
}
326
while(engine_info != NULL){
327
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
328
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
329
engine_info->file_name, tempdir);
330
break;
331
}
332
engine_info = engine_info->next;
333
}
334
if(engine_info == NULL){
335
fprintf_plus(stderr, "Could not set GPGME home dir to %s\n",
336
tempdir);
337
return false;
338
}
339
340
/* Create new GPGME "context" */
341
rc = gpgme_new(&(mc->ctx));
342
if(rc != GPG_ERR_NO_ERROR){
343
fprintf_plus(stderr, "Mandos plugin mandos-client: "
344
"bad gpgme_new: %s: %s\n", gpgme_strsource(rc),
345
gpgme_strerror(rc));
346
return false;
347
}
348
349
if(not import_key(pubkey) or not import_key(seckey)){
350
return false;
351
}
352
353
return true;
354
}
355
356
/*
357
* Decrypt OpenPGP data.
358
* Returns -1 on error
359
*/
360
__attribute__((nonnull, warn_unused_result))
361
static ssize_t pgp_packet_decrypt(const char *cryptotext,
362
size_t crypto_size,
363
char **plaintext,
364
mandos_context *mc){
365
gpgme_data_t dh_crypto, dh_plain;
366
gpgme_error_t rc;
367
ssize_t ret;
368
size_t plaintext_capacity = 0;
369
ssize_t plaintext_length = 0;
370
371
if(debug){
372
fprintf_plus(stderr, "Trying to decrypt OpenPGP data\n");
373
}
374
375
/* Create new GPGME data buffer from memory cryptotext */
376
rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,
377
0);
378
if(rc != GPG_ERR_NO_ERROR){
379
fprintf_plus(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
380
gpgme_strsource(rc), gpgme_strerror(rc));
381
return -1;
382
}
383
384
/* Create new empty GPGME data buffer for the plaintext */
385
rc = gpgme_data_new(&dh_plain);
386
if(rc != GPG_ERR_NO_ERROR){
387
fprintf_plus(stderr, "Mandos plugin mandos-client: "
388
"bad gpgme_data_new: %s: %s\n",
389
gpgme_strsource(rc), gpgme_strerror(rc));
390
gpgme_data_release(dh_crypto);
391
return -1;
392
}
393
394
/* Decrypt data from the cryptotext data buffer to the plaintext
395
data buffer */
396
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
397
if(rc != GPG_ERR_NO_ERROR){
398
fprintf_plus(stderr, "bad gpgme_op_decrypt: %s: %s\n",
399
gpgme_strsource(rc), gpgme_strerror(rc));
400
plaintext_length = -1;
401
if(debug){
402
gpgme_decrypt_result_t result;
403
result = gpgme_op_decrypt_result(mc->ctx);
404
if(result == NULL){
405
fprintf_plus(stderr, "gpgme_op_decrypt_result failed\n");
406
} else {
407
fprintf_plus(stderr, "Unsupported algorithm: %s\n",
408
result->unsupported_algorithm);
409
fprintf_plus(stderr, "Wrong key usage: %u\n",
410
result->wrong_key_usage);
411
if(result->file_name != NULL){
412
fprintf_plus(stderr, "File name: %s\n", result->file_name);
413
}
414
gpgme_recipient_t recipient;
415
recipient = result->recipients;
416
while(recipient != NULL){
417
fprintf_plus(stderr, "Public key algorithm: %s\n",
418
gpgme_pubkey_algo_name
419
(recipient->pubkey_algo));
420
fprintf_plus(stderr, "Key ID: %s\n", recipient->keyid);
421
fprintf_plus(stderr, "Secret key available: %s\n",
422
recipient->status == GPG_ERR_NO_SECKEY
423
? "No" : "Yes");
424
recipient = recipient->next;
425
}
426
}
427
}
428
goto decrypt_end;
429
}
430
431
if(debug){
432
fprintf_plus(stderr, "Decryption of OpenPGP data succeeded\n");
433
}
434
435
/* Seek back to the beginning of the GPGME plaintext data buffer */
436
if(gpgme_data_seek(dh_plain, (off_t)0, SEEK_SET) == -1){
437
perror_plus("gpgme_data_seek");
438
plaintext_length = -1;
439
goto decrypt_end;
440
}
441
442
*plaintext = NULL;
443
while(true){
444
plaintext_capacity = incbuffer(plaintext,
445
(size_t)plaintext_length,
446
plaintext_capacity);
447
if(plaintext_capacity == 0){
448
perror_plus("incbuffer");
449
plaintext_length = -1;
450
goto decrypt_end;
451
}
452
453
ret = gpgme_data_read(dh_plain, *plaintext + plaintext_length,
454
BUFFER_SIZE);
455
/* Print the data, if any */
456
if(ret == 0){
457
/* EOF */
458
break;
459
}
460
if(ret < 0){
461
perror_plus("gpgme_data_read");
462
plaintext_length = -1;
463
goto decrypt_end;
464
}
465
plaintext_length += ret;
466
}
467
468
if(debug){
469
fprintf_plus(stderr, "Decrypted password is: ");
470
for(ssize_t i = 0; i < plaintext_length; i++){
471
fprintf(stderr, "%02hhX ", (*plaintext)[i]);
472
}
473
fprintf(stderr, "\n");
474
}
475
476
decrypt_end:
477
478
/* Delete the GPGME cryptotext data buffer */
479
gpgme_data_release(dh_crypto);
480
481
/* Delete the GPGME plaintext data buffer */
482
gpgme_data_release(dh_plain);
483
return plaintext_length;
484
}
485
486
__attribute__((warn_unused_result))
487
static const char *safer_gnutls_strerror(int value){
488
const char *ret = gnutls_strerror(value);
489
if(ret == NULL)
490
ret = "(unknown)";
491
return ret;
492
}
493
494
/* GnuTLS log function callback */
495
__attribute__((nonnull))
496
static void debuggnutls(__attribute__((unused)) int level,
497
const char* string){
498
fprintf_plus(stderr, "GnuTLS: %s", string);
499
}
500
501
__attribute__((nonnull, warn_unused_result))
502
static int init_gnutls_global(const char *pubkeyfilename,
503
const char *seckeyfilename,
504
mandos_context *mc){
505
int ret;
506
507
if(debug){
508
fprintf_plus(stderr, "Initializing GnuTLS\n");
509
}
510
511
ret = gnutls_global_init();
512
if(ret != GNUTLS_E_SUCCESS){
513
fprintf_plus(stderr, "GnuTLS global_init: %s\n",
514
safer_gnutls_strerror(ret));
515
return -1;
516
}
517
518
if(debug){
519
/* "Use a log level over 10 to enable all debugging options."
520
* - GnuTLS manual
521
*/
522
gnutls_global_set_log_level(11);
523
gnutls_global_set_log_function(debuggnutls);
524
}
525
526
/* OpenPGP credentials */
527
ret = gnutls_certificate_allocate_credentials(&mc->cred);
528
if(ret != GNUTLS_E_SUCCESS){
529
fprintf_plus(stderr, "GnuTLS memory error: %s\n",
530
safer_gnutls_strerror(ret));
531
gnutls_global_deinit();
532
return -1;
533
}
534
535
if(debug){
536
fprintf_plus(stderr, "Attempting to use OpenPGP public key %s and"
537
" secret key %s as GnuTLS credentials\n",
538
pubkeyfilename,
539
seckeyfilename);
540
}
541
542
ret = gnutls_certificate_set_openpgp_key_file
543
(mc->cred, pubkeyfilename, seckeyfilename,
544
GNUTLS_OPENPGP_FMT_BASE64);
545
if(ret != GNUTLS_E_SUCCESS){
546
fprintf_plus(stderr,
547
"Error[%d] while reading the OpenPGP key pair ('%s',"
548
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
549
fprintf_plus(stderr, "The GnuTLS error is: %s\n",
550
safer_gnutls_strerror(ret));
551
goto globalfail;
552
}
553
554
/* GnuTLS server initialization */
555
ret = gnutls_dh_params_init(&mc->dh_params);
556
if(ret != GNUTLS_E_SUCCESS){
557
fprintf_plus(stderr, "Error in GnuTLS DH parameter"
558
" initialization: %s\n",
559
safer_gnutls_strerror(ret));
560
goto globalfail;
561
}
562
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
563
if(ret != GNUTLS_E_SUCCESS){
564
fprintf_plus(stderr, "Error in GnuTLS prime generation: %s\n",
565
safer_gnutls_strerror(ret));
566
goto globalfail;
567
}
568
569
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
570
571
return 0;
572
573
globalfail:
574
575
gnutls_certificate_free_credentials(mc->cred);
576
gnutls_global_deinit();
577
gnutls_dh_params_deinit(mc->dh_params);
578
return -1;
579
}
580
581
__attribute__((nonnull, warn_unused_result))
582
static int init_gnutls_session(gnutls_session_t *session,
583
mandos_context *mc){
584
int ret;
585
/* GnuTLS session creation */
586
do {
587
ret = gnutls_init(session, GNUTLS_SERVER);
588
if(quit_now){
589
return -1;
590
}
591
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
592
if(ret != GNUTLS_E_SUCCESS){
593
fprintf_plus(stderr,
594
"Error in GnuTLS session initialization: %s\n",
595
safer_gnutls_strerror(ret));
596
}
597
598
{
599
const char *err;
600
do {
601
ret = gnutls_priority_set_direct(*session, mc->priority, &err);
602
if(quit_now){
603
gnutls_deinit(*session);
604
return -1;
605
}
606
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
607
if(ret != GNUTLS_E_SUCCESS){
608
fprintf_plus(stderr, "Syntax error at: %s\n", err);
609
fprintf_plus(stderr, "GnuTLS error: %s\n",
610
safer_gnutls_strerror(ret));
611
gnutls_deinit(*session);
612
return -1;
613
}
614
}
615
616
do {
617
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
618
mc->cred);
619
if(quit_now){
620
gnutls_deinit(*session);
621
return -1;
622
}
623
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
624
if(ret != GNUTLS_E_SUCCESS){
625
fprintf_plus(stderr, "Error setting GnuTLS credentials: %s\n",
626
safer_gnutls_strerror(ret));
627
gnutls_deinit(*session);
628
return -1;
629
}
630
631
/* ignore client certificate if any. */
632
gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);
633
634
gnutls_dh_set_prime_bits(*session, mc->dh_bits);
635
636
return 0;
637
}
638
639
/* Avahi log function callback */
640
static void empty_log(__attribute__((unused)) AvahiLogLevel level,
641
__attribute__((unused)) const char *txt){}
642
643
/* Called when a Mandos server is found */
644
__attribute__((nonnull, warn_unused_result))
645
static int start_mandos_communication(const char *ip, in_port_t port,
646
AvahiIfIndex if_index,
647
int af, mandos_context *mc){
648
int ret, tcp_sd = -1;
649
ssize_t sret;
650
struct sockaddr_storage to;
651
char *buffer = NULL;
652
char *decrypted_buffer = NULL;
653
size_t buffer_length = 0;
654
size_t buffer_capacity = 0;
655
size_t written;
656
int retval = -1;
657
gnutls_session_t session;
658
int pf; /* Protocol family */
659
660
errno = 0;
661
662
if(quit_now){
663
errno = EINTR;
664
return -1;
665
}
666
667
switch(af){
668
case AF_INET6:
669
pf = PF_INET6;
670
break;
671
case AF_INET:
672
pf = PF_INET;
673
break;
674
default:
675
fprintf_plus(stderr, "Bad address family: %d\n", af);
676
errno = EINVAL;
677
return -1;
678
}
679
680
/* If the interface is specified and we have a list of interfaces */
681
if(if_index != AVAHI_IF_UNSPEC and mc->interfaces != NULL){
682
/* Check if the interface is one of the interfaces we are using */
683
bool match = false;
684
{
685
char *interface = NULL;
686
while((interface=argz_next(mc->interfaces, mc->interfaces_size,
687
interface))){
688
if(if_nametoindex(interface) == (unsigned int)if_index){
689
match = true;
690
break;
691
}
692
}
693
}
694
if(not match){
695
/* This interface does not match any in the list, so we don't
696
connect to the server */
697
if(debug){
698
char interface[IF_NAMESIZE];
699
if(if_indextoname((unsigned int)if_index, interface) == NULL){
700
perror_plus("if_indextoname");
701
} else {
702
fprintf_plus(stderr, "Skipping server on non-used interface"
703
" \"%s\"\n",
704
if_indextoname((unsigned int)if_index,
705
interface));
706
}
707
}
708
return -1;
709
}
710
}
711
712
ret = init_gnutls_session(&session, mc);
713
if(ret != 0){
714
return -1;
715
}
716
717
if(debug){
718
fprintf_plus(stderr, "Setting up a TCP connection to %s, port %"
719
PRIuMAX "\n", ip, (uintmax_t)port);
720
}
721
722
tcp_sd = socket(pf, SOCK_STREAM, 0);
723
if(tcp_sd < 0){
724
int e = errno;
725
perror_plus("socket");
726
errno = e;
727
goto mandos_end;
728
}
729
730
if(quit_now){
731
errno = EINTR;
732
goto mandos_end;
733
}
734
735
memset(&to, 0, sizeof(to));
736
if(af == AF_INET6){
737
((struct sockaddr_in6 *)&to)->sin6_family = (sa_family_t)af;
738
ret = inet_pton(af, ip, &((struct sockaddr_in6 *)&to)->sin6_addr);
739
} else { /* IPv4 */
740
((struct sockaddr_in *)&to)->sin_family = (sa_family_t)af;
741
ret = inet_pton(af, ip, &((struct sockaddr_in *)&to)->sin_addr);
742
}
743
if(ret < 0 ){
744
int e = errno;
745
perror_plus("inet_pton");
746
errno = e;
747
goto mandos_end;
748
}
749
if(ret == 0){
750
int e = errno;
751
fprintf_plus(stderr, "Bad address: %s\n", ip);
752
errno = e;
753
goto mandos_end;
754
}
755
if(af == AF_INET6){
756
((struct sockaddr_in6 *)&to)->sin6_port = htons(port);
757
if(IN6_IS_ADDR_LINKLOCAL
758
(&((struct sockaddr_in6 *)&to)->sin6_addr)){
759
if(if_index == AVAHI_IF_UNSPEC){
760
fprintf_plus(stderr, "An IPv6 link-local address is"
761
" incomplete without a network interface\n");
762
errno = EINVAL;
763
goto mandos_end;
764
}
765
/* Set the network interface number as scope */
766
((struct sockaddr_in6 *)&to)->sin6_scope_id = (uint32_t)if_index;
767
}
768
} else {
769
((struct sockaddr_in *)&to)->sin_port = htons(port);
770
}
771
772
if(quit_now){
773
errno = EINTR;
774
goto mandos_end;
775
}
776
777
if(debug){
778
if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){
779
char interface[IF_NAMESIZE];
780
if(if_indextoname((unsigned int)if_index, interface) == NULL){
781
perror_plus("if_indextoname");
782
} else {
783
fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIuMAX
784
"\n", ip, interface, (uintmax_t)port);
785
}
786
} else {
787
fprintf_plus(stderr, "Connection to: %s, port %" PRIuMAX "\n",
788
ip, (uintmax_t)port);
789
}
790
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
791
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
792
if(af == AF_INET6){
793
ret = getnameinfo((struct sockaddr *)&to,
794
sizeof(struct sockaddr_in6),
795
addrstr, sizeof(addrstr), NULL, 0,
796
NI_NUMERICHOST);
797
} else {
798
ret = getnameinfo((struct sockaddr *)&to,
799
sizeof(struct sockaddr_in),
800
addrstr, sizeof(addrstr), NULL, 0,
801
NI_NUMERICHOST);
802
}
803
if(ret == EAI_SYSTEM){
804
perror_plus("getnameinfo");
805
} else if(ret != 0) {
806
fprintf_plus(stderr, "getnameinfo: %s", gai_strerror(ret));
807
} else if(strcmp(addrstr, ip) != 0){
808
fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);
809
}
810
}
811
812
if(quit_now){
813
errno = EINTR;
814
goto mandos_end;
815
}
816
817
if(af == AF_INET6){
818
ret = connect(tcp_sd, (struct sockaddr *)&to,
819
sizeof(struct sockaddr_in6));
820
} else {
821
ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */
822
sizeof(struct sockaddr_in));
823
}
824
if(ret < 0){
825
if((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){
826
int e = errno;
827
perror_plus("connect");
828
errno = e;
829
}
830
goto mandos_end;
831
}
832
833
if(quit_now){
834
errno = EINTR;
835
goto mandos_end;
836
}
837
838
const char *out = mandos_protocol_version;
839
written = 0;
840
while(true){
841
size_t out_size = strlen(out);
842
ret = (int)TEMP_FAILURE_RETRY(write(tcp_sd, out + written,
843
out_size - written));
844
if(ret == -1){
845
int e = errno;
846
perror_plus("write");
847
errno = e;
848
goto mandos_end;
849
}
850
written += (size_t)ret;
851
if(written < out_size){
852
continue;
853
} else {
854
if(out == mandos_protocol_version){
855
written = 0;
856
out = "\r\n";
857
} else {
858
break;
859
}
860
}
861
862
if(quit_now){
863
errno = EINTR;
864
goto mandos_end;
865
}
866
}
867
868
if(debug){
869
fprintf_plus(stderr, "Establishing TLS session with %s\n", ip);
870
}
871
872
if(quit_now){
873
errno = EINTR;
874
goto mandos_end;
875
}
876
877
/* This casting via intptr_t is to eliminate warning about casting
878
an int to a pointer type. This is exactly how the GnuTLS Guile
879
function "set-session-transport-fd!" does it. */
880
gnutls_transport_set_ptr(session,
881
(gnutls_transport_ptr_t)(intptr_t)tcp_sd);
882
883
if(quit_now){
884
errno = EINTR;
885
goto mandos_end;
886
}
887
888
do {
889
ret = gnutls_handshake(session);
890
if(quit_now){
891
errno = EINTR;
892
goto mandos_end;
893
}
894
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
895
896
if(ret != GNUTLS_E_SUCCESS){
897
if(debug){
898
fprintf_plus(stderr, "*** GnuTLS Handshake failed ***\n");
899
gnutls_perror(ret);
900
}
901
errno = EPROTO;
902
goto mandos_end;
903
}
904
905
/* Read OpenPGP packet that contains the wanted password */
906
907
if(debug){
908
fprintf_plus(stderr, "Retrieving OpenPGP encrypted password from"
909
" %s\n", ip);
910
}
911
912
while(true){
913
914
if(quit_now){
915
errno = EINTR;
916
goto mandos_end;
917
}
918
919
buffer_capacity = incbuffer(&buffer, buffer_length,
920
buffer_capacity);
921
if(buffer_capacity == 0){
922
int e = errno;
923
perror_plus("incbuffer");
924
errno = e;
925
goto mandos_end;
926
}
927
928
if(quit_now){
929
errno = EINTR;
930
goto mandos_end;
931
}
932
933
sret = gnutls_record_recv(session, buffer+buffer_length,
934
BUFFER_SIZE);
935
if(sret == 0){
936
break;
937
}
938
if(sret < 0){
939
switch(sret){
940
case GNUTLS_E_INTERRUPTED:
941
case GNUTLS_E_AGAIN:
942
break;
943
case GNUTLS_E_REHANDSHAKE:
944
do {
945
ret = gnutls_handshake(session);
946
947
if(quit_now){
948
errno = EINTR;
949
goto mandos_end;
950
}
951
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
952
if(ret < 0){
953
fprintf_plus(stderr, "*** GnuTLS Re-handshake failed "
954
"***\n");
955
gnutls_perror(ret);
956
errno = EPROTO;
957
goto mandos_end;
958
}
959
break;
960
default:
961
fprintf_plus(stderr, "Unknown error while reading data from"
962
" encrypted session with Mandos server\n");
963
gnutls_bye(session, GNUTLS_SHUT_RDWR);
964
errno = EIO;
965
goto mandos_end;
966
}
967
} else {
968
buffer_length += (size_t) sret;
969
}
970
}
971
972
if(debug){
973
fprintf_plus(stderr, "Closing TLS session\n");
974
}
975
976
if(quit_now){
977
errno = EINTR;
978
goto mandos_end;
979
}
980
981
do {
982
ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);
983
if(quit_now){
984
errno = EINTR;
985
goto mandos_end;
986
}
987
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
988
989
if(buffer_length > 0){
990
ssize_t decrypted_buffer_size;
991
decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,
992
&decrypted_buffer, mc);
993
if(decrypted_buffer_size >= 0){
994
995
written = 0;
996
while(written < (size_t) decrypted_buffer_size){
997
if(quit_now){
998
errno = EINTR;
999
goto mandos_end;
1000
}
1001
1002
ret = (int)fwrite(decrypted_buffer + written, 1,
1003
(size_t)decrypted_buffer_size - written,
1004
stdout);
1005
if(ret == 0 and ferror(stdout)){
1006
int e = errno;
1007
if(debug){
1008
fprintf_plus(stderr, "Error writing encrypted data: %s\n",
1009
strerror(errno));
1010
}
1011
errno = e;
1012
goto mandos_end;
1013
}
1014
written += (size_t)ret;
1015
}
1016
retval = 0;
1017
}
1018
}
1019
1020
/* Shutdown procedure */
1021
1022
mandos_end:
1023
{
1024
int e = errno;
1025
free(decrypted_buffer);
1026
free(buffer);
1027
if(tcp_sd >= 0){
1028
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
1029
}
1030
if(ret == -1){
1031
if(e == 0){
1032
e = errno;
1033
}
1034
perror_plus("close");
1035
}
1036
gnutls_deinit(session);
1037
errno = e;
1038
if(quit_now){
1039
errno = EINTR;
1040
retval = -1;
1041
}
1042
}
1043
return retval;
1044
}
1045
1046
__attribute__((nonnull))
1047
static void resolve_callback(AvahiSServiceResolver *r,
1048
AvahiIfIndex interface,
1049
AvahiProtocol proto,
1050
AvahiResolverEvent event,
1051
const char *name,
1052
const char *type,
1053
const char *domain,
1054
const char *host_name,
1055
const AvahiAddress *address,
1056
uint16_t port,
1057
AVAHI_GCC_UNUSED AvahiStringList *txt,
1058
AVAHI_GCC_UNUSED AvahiLookupResultFlags
1059
flags,
1060
void *mc){
1061
if(r == NULL){
1062
return;
1063
}
1064
1065
/* Called whenever a service has been resolved successfully or
1066
timed out */
1067
1068
if(quit_now){
1069
return;
1070
}
1071
1072
switch(event){
1073
default:
1074
case AVAHI_RESOLVER_FAILURE:
1075
fprintf_plus(stderr, "(Avahi Resolver) Failed to resolve service "
1076
"'%s' of type '%s' in domain '%s': %s\n", name, type,
1077
domain,
1078
avahi_strerror(avahi_server_errno
1079
(((mandos_context*)mc)->server)));
1080
break;
1081
1082
case AVAHI_RESOLVER_FOUND:
1083
{
1084
char ip[AVAHI_ADDRESS_STR_MAX];
1085
avahi_address_snprint(ip, sizeof(ip), address);
1086
if(debug){
1087
fprintf_plus(stderr, "Mandos server \"%s\" found on %s (%s, %"
1088
PRIdMAX ") on port %" PRIu16 "\n", name,
1089
host_name, ip, (intmax_t)interface, port);
1090
}
1091
int ret = start_mandos_communication(ip, (in_port_t)port,
1092
interface,
1093
avahi_proto_to_af(proto),
1094
mc);
1095
if(ret == 0){
1096
avahi_simple_poll_quit(simple_poll);
1097
} else {
1098
if(not add_server(ip, (in_port_t)port, interface,
1099
avahi_proto_to_af(proto),
1100
&((mandos_context*)mc)->current_server)){
1101
fprintf_plus(stderr, "Failed to add server \"%s\" to server"
1102
" list\n", name);
1103
}
1104
}
1105
}
1106
}
1107
avahi_s_service_resolver_free(r);
1108
}
1109
1110
static void browse_callback(AvahiSServiceBrowser *b,
1111
AvahiIfIndex interface,
1112
AvahiProtocol protocol,
1113
AvahiBrowserEvent event,
1114
const char *name,
1115
const char *type,
1116
const char *domain,
1117
AVAHI_GCC_UNUSED AvahiLookupResultFlags
1118
flags,
1119
void *mc){
1120
if(b == NULL){
1121
return;
1122
}
1123
1124
/* Called whenever a new services becomes available on the LAN or
1125
is removed from the LAN */
1126
1127
if(quit_now){
1128
return;
1129
}
1130
1131
switch(event){
1132
default:
1133
case AVAHI_BROWSER_FAILURE:
1134
1135
fprintf_plus(stderr, "(Avahi browser) %s\n",
1136
avahi_strerror(avahi_server_errno
1137
(((mandos_context*)mc)->server)));
1138
avahi_simple_poll_quit(simple_poll);
1139
return;
1140
1141
case AVAHI_BROWSER_NEW:
1142
/* We ignore the returned Avahi resolver object. In the callback
1143
function we free it. If the Avahi server is terminated before
1144
the callback function is called the Avahi server will free the
1145
resolver for us. */
1146
1147
if(avahi_s_service_resolver_new(((mandos_context*)mc)->server,
1148
interface, protocol, name, type,
1149
domain, protocol, 0,
1150
resolve_callback, mc) == NULL)
1151
fprintf_plus(stderr, "Avahi: Failed to resolve service '%s':"
1152
" %s\n", name,
1153
avahi_strerror(avahi_server_errno
1154
(((mandos_context*)mc)->server)));
1155
break;
1156
1157
case AVAHI_BROWSER_REMOVE:
1158
break;
1159
1160
case AVAHI_BROWSER_ALL_FOR_NOW:
1161
case AVAHI_BROWSER_CACHE_EXHAUSTED:
1162
if(debug){
1163
fprintf_plus(stderr, "No Mandos server found, still"
1164
" searching...\n");
1165
}
1166
break;
1167
}
1168
}
1169
1170
/* Signal handler that stops main loop after SIGTERM */
1171
static void handle_sigterm(int sig){
1172
if(quit_now){
1173
return;
1174
}
1175
quit_now = 1;
1176
signal_received = sig;
1177
int old_errno = errno;
1178
/* set main loop to exit */
1179
if(simple_poll != NULL){
1180
avahi_simple_poll_quit(simple_poll);
1181
}
1182
errno = old_errno;
1183
}
1184
1185
__attribute__((nonnull, warn_unused_result))
1186
bool get_flags(const char *ifname, struct ifreq *ifr){
1187
int ret;
1188
error_t ret_errno;
1189
1190
int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1191
if(s < 0){
1192
ret_errno = errno;
1193
perror_plus("socket");
1194
errno = ret_errno;
1195
return false;
1196
}
1197
strcpy(ifr->ifr_name, ifname);
1198
ret = ioctl(s, SIOCGIFFLAGS, ifr);
1199
if(ret == -1){
1200
if(debug){
1201
ret_errno = errno;
1202
perror_plus("ioctl SIOCGIFFLAGS");
1203
errno = ret_errno;
1204
}
1205
return false;
1206
}
1207
return true;
1208
}
1209
1210
__attribute__((nonnull, warn_unused_result))
1211
bool good_flags(const char *ifname, const struct ifreq *ifr){
1212
1213
/* Reject the loopback device */
1214
if(ifr->ifr_flags & IFF_LOOPBACK){
1215
if(debug){
1216
fprintf_plus(stderr, "Rejecting loopback interface \"%s\"\n",
1217
ifname);
1218
}
1219
return false;
1220
}
1221
/* Accept point-to-point devices only if connect_to is specified */
1222
if(connect_to != NULL and (ifr->ifr_flags & IFF_POINTOPOINT)){
1223
if(debug){
1224
fprintf_plus(stderr, "Accepting point-to-point interface"
1225
" \"%s\"\n", ifname);
1226
}
1227
return true;
1228
}
1229
/* Otherwise, reject non-broadcast-capable devices */
1230
if(not (ifr->ifr_flags & IFF_BROADCAST)){
1231
if(debug){
1232
fprintf_plus(stderr, "Rejecting non-broadcast interface"
1233
" \"%s\"\n", ifname);
1234
}
1235
return false;
1236
}
1237
/* Reject non-ARP interfaces (including dummy interfaces) */
1238
if(ifr->ifr_flags & IFF_NOARP){
1239
if(debug){
1240
fprintf_plus(stderr, "Rejecting non-ARP interface \"%s\"\n",
1241
ifname);
1242
}
1243
return false;
1244
}
1245
1246
/* Accept this device */
1247
if(debug){
1248
fprintf_plus(stderr, "Interface \"%s\" is good\n", ifname);
1249
}
1250
return true;
1251
}
1252
1253
/*
1254
* This function determines if a directory entry in /sys/class/net
1255
* corresponds to an acceptable network device.
1256
* (This function is passed to scandir(3) as a filter function.)
1257
*/
1258
__attribute__((nonnull, warn_unused_result))
1259
int good_interface(const struct dirent *if_entry){
1260
if(if_entry->d_name[0] == '.'){
1261
return 0;
1262
}
1263
1264
struct ifreq ifr;
1265
if(not get_flags(if_entry->d_name, &ifr)){
1266
if(debug){
1267
fprintf_plus(stderr, "Failed to get flags for interface "
1268
"\"%s\"\n", if_entry->d_name);
1269
}
1270
return 0;
1271
}
1272
1273
if(not good_flags(if_entry->d_name, &ifr)){
1274
return 0;
1275
}
1276
return 1;
1277
}
1278
1279
/*
1280
* This function determines if a network interface is up.
1281
*/
1282
__attribute__((nonnull, warn_unused_result))
1283
bool interface_is_up(const char *interface){
1284
struct ifreq ifr;
1285
if(not get_flags(interface, &ifr)){
1286
if(debug){
1287
fprintf_plus(stderr, "Failed to get flags for interface "
1288
"\"%s\"\n", interface);
1289
}
1290
return false;
1291
}
1292
1293
return (bool)(ifr.ifr_flags & IFF_UP);
1294
}
1295
1296
/*
1297
* This function determines if a network interface is running
1298
*/
1299
__attribute__((nonnull, warn_unused_result))
1300
bool interface_is_running(const char *interface){
1301
struct ifreq ifr;
1302
if(not get_flags(interface, &ifr)){
1303
if(debug){
1304
fprintf_plus(stderr, "Failed to get flags for interface "
1305
"\"%s\"\n", interface);
1306
}
1307
return false;
1308
}
1309
1310
return (bool)(ifr.ifr_flags & IFF_RUNNING);
1311
}
1312
1313
__attribute__((nonnull, pure, warn_unused_result))
1314
int notdotentries(const struct dirent *direntry){
1315
/* Skip "." and ".." */
1316
if(direntry->d_name[0] == '.'
1317
and (direntry->d_name[1] == '\0'
1318
or (direntry->d_name[1] == '.'
1319
and direntry->d_name[2] == '\0'))){
1320
return 0;
1321
}
1322
return 1;
1323
}
1324
1325
/* Is this directory entry a runnable program? */
1326
__attribute__((nonnull, warn_unused_result))
1327
int runnable_hook(const struct dirent *direntry){
1328
int ret;
1329
size_t sret;
1330
struct stat st;
1331
1332
if((direntry->d_name)[0] == '\0'){
1333
/* Empty name? */
1334
return 0;
1335
}
1336
1337
sret = strspn(direntry->d_name, "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
1338
"abcdefghijklmnopqrstuvwxyz"
1339
"0123456789"
1340
"_.-");
1341
if((direntry->d_name)[sret] != '\0'){
1342
/* Contains non-allowed characters */
1343
if(debug){
1344
fprintf_plus(stderr, "Ignoring hook \"%s\" with bad name\n",
1345
direntry->d_name);
1346
}
1347
return 0;
1348
}
1349
1350
ret = fstatat(hookdir_fd, direntry->d_name, &st, 0);
1351
if(ret == -1){
1352
if(debug){
1353
perror_plus("Could not stat hook");
1354
}
1355
return 0;
1356
}
1357
if(not (S_ISREG(st.st_mode))){
1358
/* Not a regular file */
1359
if(debug){
1360
fprintf_plus(stderr, "Ignoring hook \"%s\" - not a file\n",
1361
direntry->d_name);
1362
}
1363
return 0;
1364
}
1365
if(not (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))){
1366
/* Not executable */
1367
if(debug){
1368
fprintf_plus(stderr, "Ignoring hook \"%s\" - not executable\n",
1369
direntry->d_name);
1370
}
1371
return 0;
1372
}
1373
if(debug){
1374
fprintf_plus(stderr, "Hook \"%s\" is acceptable\n",
1375
direntry->d_name);
1376
}
1377
return 1;
1378
}
1379
1380
__attribute__((nonnull, warn_unused_result))
1381
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,
1382
mandos_context *mc){
1383
int ret;
1384
struct timespec now;
1385
struct timespec waited_time;
1386
intmax_t block_time;
1387
1388
while(true){
1389
if(mc->current_server == NULL){
1390
if(debug){
1391
fprintf_plus(stderr, "Wait until first server is found."
1392
" No timeout!\n");
1393
}
1394
ret = avahi_simple_poll_iterate(s, -1);
1395
} else {
1396
if(debug){
1397
fprintf_plus(stderr, "Check current_server if we should run"
1398
" it, or wait\n");
1399
}
1400
/* the current time */
1401
ret = clock_gettime(CLOCK_MONOTONIC, &now);
1402
if(ret == -1){
1403
perror_plus("clock_gettime");
1404
return -1;
1405
}
1406
/* Calculating in ms how long time between now and server
1407
who we visted longest time ago. Now - last seen. */
1408
waited_time.tv_sec = (now.tv_sec
1409
- mc->current_server->last_seen.tv_sec);
1410
waited_time.tv_nsec = (now.tv_nsec
1411
- mc->current_server->last_seen.tv_nsec);
1412
/* total time is 10s/10,000ms.
1413
Converting to s from ms by dividing by 1,000,
1414
and ns to ms by dividing by 1,000,000. */
1415
block_time = ((retry_interval
1416
- ((intmax_t)waited_time.tv_sec * 1000))
1417
- ((intmax_t)waited_time.tv_nsec / 1000000));
1418
1419
if(debug){
1420
fprintf_plus(stderr, "Blocking for %" PRIdMAX " ms\n",
1421
block_time);
1422
}
1423
1424
if(block_time <= 0){
1425
ret = start_mandos_communication(mc->current_server->ip,
1426
mc->current_server->port,
1427
mc->current_server->if_index,
1428
mc->current_server->af, mc);
1429
if(ret == 0){
1430
avahi_simple_poll_quit(s);
1431
return 0;
1432
}
1433
ret = clock_gettime(CLOCK_MONOTONIC,
1434
&mc->current_server->last_seen);
1435
if(ret == -1){
1436
perror_plus("clock_gettime");
1437
return -1;
1438
}
1439
mc->current_server = mc->current_server->next;
1440
block_time = 0; /* Call avahi to find new Mandos
1441
servers, but don't block */
1442
}
1443
1444
ret = avahi_simple_poll_iterate(s, (int)block_time);
1445
}
1446
if(ret != 0){
1447
if(ret > 0 or errno != EINTR){
1448
return (ret != 1) ? ret : 0;
1449
}
1450
}
1451
}
1452
}
1453
1454
/* Set effective uid to 0, return errno */
1455
__attribute__((warn_unused_result))
1456
error_t raise_privileges(void){
1457
error_t old_errno = errno;
1458
error_t ret_errno = 0;
1459
if(seteuid(0) == -1){
1460
ret_errno = errno;
1461
perror_plus("seteuid");
1462
}
1463
errno = old_errno;
1464
return ret_errno;
1465
}
1466
1467
/* Set effective and real user ID to 0. Return errno. */
1468
__attribute__((warn_unused_result))
1469
error_t raise_privileges_permanently(void){
1470
error_t old_errno = errno;
1471
error_t ret_errno = raise_privileges();
1472
if(ret_errno != 0){
1473
errno = old_errno;
1474
return ret_errno;
1475
}
1476
if(setuid(0) == -1){
1477
ret_errno = errno;
1478
perror_plus("seteuid");
1479
}
1480
errno = old_errno;
1481
return ret_errno;
1482
}
1483
1484
/* Set effective user ID to unprivileged saved user ID */
1485
__attribute__((warn_unused_result))
1486
error_t lower_privileges(void){
1487
error_t old_errno = errno;
1488
error_t ret_errno = 0;
1489
if(seteuid(uid) == -1){
1490
ret_errno = errno;
1491
perror_plus("seteuid");
1492
}
1493
errno = old_errno;
1494
return ret_errno;
1495
}
1496
1497
/* Lower privileges permanently */
1498
__attribute__((warn_unused_result))
1499
error_t lower_privileges_permanently(void){
1500
error_t old_errno = errno;
1501
error_t ret_errno = 0;
1502
if(setuid(uid) == -1){
1503
ret_errno = errno;
1504
perror_plus("setuid");
1505
}
1506
errno = old_errno;
1507
return ret_errno;
1508
}
1509
1510
__attribute__((nonnull))
1511
void run_network_hooks(const char *mode, const char *interface,
1512
const float delay){
1513
struct dirent **direntries;
1514
if(hookdir_fd == -1){
1515
hookdir_fd = open(hookdir, O_RDONLY);
1516
if(hookdir_fd == -1){
1517
if(errno == ENOENT){
1518
if(debug){
1519
fprintf_plus(stderr, "Network hook directory \"%s\" not"
1520
" found\n", hookdir);
1521
}
1522
} else {
1523
perror_plus("open");
1524
}
1525
return;
1526
}
1527
}
1528
#ifdef __GLIBC__
1529
#if __GLIBC_PREREQ(2, 15)
1530
int numhooks = scandirat(hookdir_fd, ".", &direntries,
1531
runnable_hook, alphasort);
1532
#else /* not __GLIBC_PREREQ(2, 15) */
1533
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1534
alphasort);
1535
#endif /* not __GLIBC_PREREQ(2, 15) */
1536
#else /* not __GLIBC__ */
1537
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1538
alphasort);
1539
#endif /* not __GLIBC__ */
1540
if(numhooks == -1){
1541
perror_plus("scandir");
1542
return;
1543
}
1544
struct dirent *direntry;
1545
int ret;
1546
int devnull = open("/dev/null", O_RDONLY);
1547
for(int i = 0; i < numhooks; i++){
1548
direntry = direntries[i];
1549
if(debug){
1550
fprintf_plus(stderr, "Running network hook \"%s\"\n",
1551
direntry->d_name);
1552
}
1553
pid_t hook_pid = fork();
1554
if(hook_pid == 0){
1555
/* Child */
1556
/* Raise privileges */
1557
if(raise_privileges_permanently() != 0){
1558
perror_plus("Failed to raise privileges");
1559
_exit(EX_NOPERM);
1560
}
1561
/* Set group */
1562
errno = 0;
1563
ret = setgid(0);
1564
if(ret == -1){
1565
perror_plus("setgid");
1566
_exit(EX_NOPERM);
1567
}
1568
/* Reset supplementary groups */
1569
errno = 0;
1570
ret = setgroups(0, NULL);
1571
if(ret == -1){
1572
perror_plus("setgroups");
1573
_exit(EX_NOPERM);
1574
}
1575
ret = dup2(devnull, STDIN_FILENO);
1576
if(ret == -1){
1577
perror_plus("dup2(devnull, STDIN_FILENO)");
1578
_exit(EX_OSERR);
1579
}
1580
ret = close(devnull);
1581
if(ret == -1){
1582
perror_plus("close");
1583
_exit(EX_OSERR);
1584
}
1585
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
1586
if(ret == -1){
1587
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
1588
_exit(EX_OSERR);
1589
}
1590
ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);
1591
if(ret == -1){
1592
perror_plus("setenv");
1593
_exit(EX_OSERR);
1594
}
1595
ret = setenv("DEVICE", interface, 1);
1596
if(ret == -1){
1597
perror_plus("setenv");
1598
_exit(EX_OSERR);
1599
}
1600
ret = setenv("VERBOSITY", debug ? "1" : "0", 1);
1601
if(ret == -1){
1602
perror_plus("setenv");
1603
_exit(EX_OSERR);
1604
}
1605
ret = setenv("MODE", mode, 1);
1606
if(ret == -1){
1607
perror_plus("setenv");
1608
_exit(EX_OSERR);
1609
}
1610
char *delaystring;
1611
ret = asprintf(&delaystring, "%f", (double)delay);
1612
if(ret == -1){
1613
perror_plus("asprintf");
1614
_exit(EX_OSERR);
1615
}
1616
ret = setenv("DELAY", delaystring, 1);
1617
if(ret == -1){
1618
free(delaystring);
1619
perror_plus("setenv");
1620
_exit(EX_OSERR);
1621
}
1622
free(delaystring);
1623
if(connect_to != NULL){
1624
ret = setenv("CONNECT", connect_to, 1);
1625
if(ret == -1){
1626
perror_plus("setenv");
1627
_exit(EX_OSERR);
1628
}
1629
}
1630
int hook_fd = openat(hookdir_fd, direntry->d_name, O_RDONLY);
1631
if(hook_fd == -1){
1632
perror_plus("openat");
1633
_exit(EXIT_FAILURE);
1634
}
1635
if((int)TEMP_FAILURE_RETRY(close(hookdir_fd)) == -1){
1636
perror_plus("close");
1637
_exit(EXIT_FAILURE);
1638
}
1639
if(fexecve(hook_fd, (char *const []){ direntry->d_name, NULL },
1640
environ) == -1){
1641
perror_plus("fexecve");
1642
_exit(EXIT_FAILURE);
1643
}
1644
} else {
1645
int status;
1646
if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){
1647
perror_plus("waitpid");
1648
continue;
1649
}
1650
if(WIFEXITED(status)){
1651
if(WEXITSTATUS(status) != 0){
1652
fprintf_plus(stderr, "Warning: network hook \"%s\" exited"
1653
" with status %d\n", direntry->d_name,
1654
WEXITSTATUS(status));
1655
continue;
1656
}
1657
} else if(WIFSIGNALED(status)){
1658
fprintf_plus(stderr, "Warning: network hook \"%s\" died by"
1659
" signal %d\n", direntry->d_name,
1660
WTERMSIG(status));
1661
continue;
1662
} else {
1663
fprintf_plus(stderr, "Warning: network hook \"%s\""
1664
" crashed\n", direntry->d_name);
1665
continue;
1666
}
1667
}
1668
if(debug){
1669
fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",
1670
direntry->d_name);
1671
}
1672
}
1673
if((int)TEMP_FAILURE_RETRY(close(hookdir_fd)) == -1){
1674
perror_plus("close");
1675
} else {
1676
hookdir_fd = -1;
1677
}
1678
close(devnull);
1679
}
1680
1681
__attribute__((nonnull, warn_unused_result))
1682
error_t bring_up_interface(const char *const interface,
1683
const float delay){
1684
error_t old_errno = errno;
1685
int ret;
1686
struct ifreq network;
1687
unsigned int if_index = if_nametoindex(interface);
1688
if(if_index == 0){
1689
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1690
errno = old_errno;
1691
return ENXIO;
1692
}
1693
1694
if(quit_now){
1695
errno = old_errno;
1696
return EINTR;
1697
}
1698
1699
if(not interface_is_up(interface)){
1700
error_t ret_errno = 0, ioctl_errno = 0;
1701
if(not get_flags(interface, &network)){
1702
ret_errno = errno;
1703
fprintf_plus(stderr, "Failed to get flags for interface "
1704
"\"%s\"\n", interface);
1705
errno = old_errno;
1706
return ret_errno;
1707
}
1708
network.ifr_flags |= IFF_UP; /* set flag */
1709
1710
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1711
if(sd == -1){
1712
ret_errno = errno;
1713
perror_plus("socket");
1714
errno = old_errno;
1715
return ret_errno;
1716
}
1717
1718
if(quit_now){
1719
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1720
if(ret == -1){
1721
perror_plus("close");
1722
}
1723
errno = old_errno;
1724
return EINTR;
1725
}
1726
1727
if(debug){
1728
fprintf_plus(stderr, "Bringing up interface \"%s\"\n",
1729
interface);
1730
}
1731
1732
/* Raise privileges */
1733
ret_errno = raise_privileges();
1734
if(ret_errno != 0){
1735
perror_plus("Failed to raise privileges");
1736
}
1737
1738
#ifdef __linux__
1739
int ret_linux;
1740
bool restore_loglevel = false;
1741
if(ret_errno == 0){
1742
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1743
messages about the network interface to mess up the prompt */
1744
ret_linux = klogctl(8, NULL, 5);
1745
if(ret_linux == -1){
1746
perror_plus("klogctl");
1747
} else {
1748
restore_loglevel = true;
1749
}
1750
}
1751
#endif /* __linux__ */
1752
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1753
ioctl_errno = errno;
1754
#ifdef __linux__
1755
if(restore_loglevel){
1756
ret_linux = klogctl(7, NULL, 0);
1757
if(ret_linux == -1){
1758
perror_plus("klogctl");
1759
}
1760
}
1761
#endif /* __linux__ */
1762
1763
/* If raise_privileges() succeeded above */
1764
if(ret_errno == 0){
1765
/* Lower privileges */
1766
ret_errno = lower_privileges();
1767
if(ret_errno != 0){
1768
errno = ret_errno;
1769
perror_plus("Failed to lower privileges");
1770
}
1771
}
1772
1773
/* Close the socket */
1774
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1775
if(ret == -1){
1776
perror_plus("close");
1777
}
1778
1779
if(ret_setflags == -1){
1780
errno = ioctl_errno;
1781
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1782
errno = old_errno;
1783
return ioctl_errno;
1784
}
1785
} else if(debug){
1786
fprintf_plus(stderr, "Interface \"%s\" is already up; good\n",
1787
interface);
1788
}
1789
1790
/* Sleep checking until interface is running.
1791
Check every 0.25s, up to total time of delay */
1792
for(int i=0; i < delay * 4; i++){
1793
if(interface_is_running(interface)){
1794
break;
1795
}
1796
struct timespec sleeptime = { .tv_nsec = 250000000 };
1797
ret = nanosleep(&sleeptime, NULL);
1798
if(ret == -1 and errno != EINTR){
1799
perror_plus("nanosleep");
1800
}
1801
}
1802
1803
errno = old_errno;
1804
return 0;
1805
}
1806
1807
__attribute__((nonnull, warn_unused_result))
1808
error_t take_down_interface(const char *const interface){
1809
error_t old_errno = errno;
1810
struct ifreq network;
1811
unsigned int if_index = if_nametoindex(interface);
1812
if(if_index == 0){
1813
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1814
errno = old_errno;
1815
return ENXIO;
1816
}
1817
if(interface_is_up(interface)){
1818
error_t ret_errno = 0, ioctl_errno = 0;
1819
if(not get_flags(interface, &network) and debug){
1820
ret_errno = errno;
1821
fprintf_plus(stderr, "Failed to get flags for interface "
1822
"\"%s\"\n", interface);
1823
errno = old_errno;
1824
return ret_errno;
1825
}
1826
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1827
1828
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1829
if(sd == -1){
1830
ret_errno = errno;
1831
perror_plus("socket");
1832
errno = old_errno;
1833
return ret_errno;
1834
}
1835
1836
if(debug){
1837
fprintf_plus(stderr, "Taking down interface \"%s\"\n",
1838
interface);
1839
}
1840
1841
/* Raise privileges */
1842
ret_errno = raise_privileges();
1843
if(ret_errno != 0){
1844
perror_plus("Failed to raise privileges");
1845
}
1846
1847
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1848
ioctl_errno = errno;
1849
1850
/* If raise_privileges() succeeded above */
1851
if(ret_errno == 0){
1852
/* Lower privileges */
1853
ret_errno = lower_privileges();
1854
if(ret_errno != 0){
1855
errno = ret_errno;
1856
perror_plus("Failed to lower privileges");
1857
}
1858
}
1859
1860
/* Close the socket */
1861
int ret = (int)TEMP_FAILURE_RETRY(close(sd));
1862
if(ret == -1){
1863
perror_plus("close");
1864
}
1865
1866
if(ret_setflags == -1){
1867
errno = ioctl_errno;
1868
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
1869
errno = old_errno;
1870
return ioctl_errno;
1871
}
1872
} else if(debug){
1873
fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",
1874
interface);
1875
}
1876
1877
errno = old_errno;
1878
return 0;
1879
}
1880
1881
int main(int argc, char *argv[]){
1882
mandos_context mc = { .server = NULL, .dh_bits = 1024,
1883
.priority = "SECURE256:!CTYPE-X.509:"
1884
"+CTYPE-OPENPGP", .current_server = NULL,
1885
.interfaces = NULL, .interfaces_size = 0 };
1886
AvahiSServiceBrowser *sb = NULL;
1887
error_t ret_errno;
1888
int ret;
1889
intmax_t tmpmax;
1890
char *tmp;
1891
int exitcode = EXIT_SUCCESS;
1892
char *interfaces_to_take_down = NULL;
1893
size_t interfaces_to_take_down_size = 0;
1894
char run_tempdir[] = "/run/tmp/mandosXXXXXX";
1895
char old_tempdir[] = "/tmp/mandosXXXXXX";
1896
char *tempdir = NULL;
1897
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
1898
const char *seckey = PATHDIR "/" SECKEY;
1899
const char *pubkey = PATHDIR "/" PUBKEY;
1900
char *interfaces_hooks = NULL;
1901
1902
bool gnutls_initialized = false;
1903
bool gpgme_initialized = false;
1904
float delay = 2.5f;
1905
double retry_interval = 10; /* 10s between trying a server and
1906
retrying the same server again */
1907
1908
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
1909
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
1910
1911
uid = getuid();
1912
gid = getgid();
1913
1914
/* Lower any group privileges we might have, just to be safe */
1915
errno = 0;
1916
ret = setgid(gid);
1917
if(ret == -1){
1918
perror_plus("setgid");
1919
}
1920
1921
/* Lower user privileges (temporarily) */
1922
errno = 0;
1923
ret = seteuid(uid);
1924
if(ret == -1){
1925
perror_plus("seteuid");
1926
}
1927
1928
if(quit_now){
1929
goto end;
1930
}
1931
1932
{
1933
struct argp_option options[] = {
1934
{ .name = "debug", .key = 128,
1935
.doc = "Debug mode", .group = 3 },
1936
{ .name = "connect", .key = 'c',
1937
.arg = "ADDRESS:PORT",
1938
.doc = "Connect directly to a specific Mandos server",
1939
.group = 1 },
1940
{ .name = "interface", .key = 'i',
1941
.arg = "NAME",
1942
.doc = "Network interface that will be used to search for"
1943
" Mandos servers",
1944
.group = 1 },
1945
{ .name = "seckey", .key = 's',
1946
.arg = "FILE",
1947
.doc = "OpenPGP secret key file base name",
1948
.group = 1 },
1949
{ .name = "pubkey", .key = 'p',
1950
.arg = "FILE",
1951
.doc = "OpenPGP public key file base name",
1952
.group = 2 },
1953
{ .name = "dh-bits", .key = 129,
1954
.arg = "BITS",
1955
.doc = "Bit length of the prime number used in the"
1956
" Diffie-Hellman key exchange",
1957
.group = 2 },
1958
{ .name = "priority", .key = 130,
1959
.arg = "STRING",
1960
.doc = "GnuTLS priority string for the TLS handshake",
1961
.group = 1 },
1962
{ .name = "delay", .key = 131,
1963
.arg = "SECONDS",
1964
.doc = "Maximum delay to wait for interface startup",
1965
.group = 2 },
1966
{ .name = "retry", .key = 132,
1967
.arg = "SECONDS",
1968
.doc = "Retry interval used when denied by the Mandos server",
1969
.group = 2 },
1970
{ .name = "network-hook-dir", .key = 133,
1971
.arg = "DIR",
1972
.doc = "Directory where network hooks are located",
1973
.group = 2 },
1974
/*
1975
* These reproduce what we would get without ARGP_NO_HELP
1976
*/
1977
{ .name = "help", .key = '?',
1978
.doc = "Give this help list", .group = -1 },
1979
{ .name = "usage", .key = -3,
1980
.doc = "Give a short usage message", .group = -1 },
1981
{ .name = "version", .key = 'V',
1982
.doc = "Print program version", .group = -1 },
1983
{ .name = NULL }
1984
};
1985
1986
error_t parse_opt(int key, char *arg,
1987
struct argp_state *state){
1988
errno = 0;
1989
switch(key){
1990
case 128: /* --debug */
1991
debug = true;
1992
break;
1993
case 'c': /* --connect */
1994
connect_to = arg;
1995
break;
1996
case 'i': /* --interface */
1997
ret_errno = argz_add_sep(&mc.interfaces, &mc.interfaces_size,
1998
arg, (int)',');
1999
if(ret_errno != 0){
2000
argp_error(state, "%s", strerror(ret_errno));
2001
}
2002
break;
2003
case 's': /* --seckey */
2004
seckey = arg;
2005
break;
2006
case 'p': /* --pubkey */
2007
pubkey = arg;
2008
break;
2009
case 129: /* --dh-bits */
2010
errno = 0;
2011
tmpmax = strtoimax(arg, &tmp, 10);
2012
if(errno != 0 or tmp == arg or *tmp != '\0'
2013
or tmpmax != (typeof(mc.dh_bits))tmpmax){
2014
argp_error(state, "Bad number of DH bits");
2015
}
2016
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
2017
break;
2018
case 130: /* --priority */
2019
mc.priority = arg;
2020
break;
2021
case 131: /* --delay */
2022
errno = 0;
2023
delay = strtof(arg, &tmp);
2024
if(errno != 0 or tmp == arg or *tmp != '\0'){
2025
argp_error(state, "Bad delay");
2026
}
2027
case 132: /* --retry */
2028
errno = 0;
2029
retry_interval = strtod(arg, &tmp);
2030
if(errno != 0 or tmp == arg or *tmp != '\0'
2031
or (retry_interval * 1000) > INT_MAX
2032
or retry_interval < 0){
2033
argp_error(state, "Bad retry interval");
2034
}
2035
break;
2036
case 133: /* --network-hook-dir */
2037
hookdir = arg;
2038
break;
2039
/*
2040
* These reproduce what we would get without ARGP_NO_HELP
2041
*/
2042
case '?': /* --help */
2043
argp_state_help(state, state->out_stream,
2044
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
2045
& ~(unsigned int)ARGP_HELP_EXIT_OK);
2046
case -3: /* --usage */
2047
argp_state_help(state, state->out_stream,
2048
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
2049
case 'V': /* --version */
2050
fprintf_plus(state->out_stream, "%s\n", argp_program_version);
2051
exit(argp_err_exit_status);
2052
break;
2053
default:
2054
return ARGP_ERR_UNKNOWN;
2055
}
2056
return errno;
2057
}
2058
2059
struct argp argp = { .options = options, .parser = parse_opt,
2060
.args_doc = "",
2061
.doc = "Mandos client -- Get and decrypt"
2062
" passwords from a Mandos server" };
2063
ret = argp_parse(&argp, argc, argv,
2064
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
2065
switch(ret){
2066
case 0:
2067
break;
2068
case ENOMEM:
2069
default:
2070
errno = ret;
2071
perror_plus("argp_parse");
2072
exitcode = EX_OSERR;
2073
goto end;
2074
case EINVAL:
2075
exitcode = EX_USAGE;
2076
goto end;
2077
}
2078
}
2079
2080
{
2081
/* Work around Debian bug #633582:
2082
<http://bugs.debian.org/633582> */
2083
2084
/* Re-raise privileges */
2085
ret_errno = raise_privileges();
2086
if(ret_errno != 0){
2087
errno = ret_errno;
2088
perror_plus("Failed to raise privileges");
2089
} else {
2090
struct stat st;
2091
2092
if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){
2093
int seckey_fd = open(seckey, O_RDONLY);
2094
if(seckey_fd == -1){
2095
perror_plus("open");
2096
} else {
2097
ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));
2098
if(ret == -1){
2099
perror_plus("fstat");
2100
} else {
2101
if(S_ISREG(st.st_mode)
2102
and st.st_uid == 0 and st.st_gid == 0){
2103
ret = fchown(seckey_fd, uid, gid);
2104
if(ret == -1){
2105
perror_plus("fchown");
2106
}
2107
}
2108
}
2109
TEMP_FAILURE_RETRY(close(seckey_fd));
2110
}
2111
}
2112
2113
if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){
2114
int pubkey_fd = open(pubkey, O_RDONLY);
2115
if(pubkey_fd == -1){
2116
perror_plus("open");
2117
} else {
2118
ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));
2119
if(ret == -1){
2120
perror_plus("fstat");
2121
} else {
2122
if(S_ISREG(st.st_mode)
2123
and st.st_uid == 0 and st.st_gid == 0){
2124
ret = fchown(pubkey_fd, uid, gid);
2125
if(ret == -1){
2126
perror_plus("fchown");
2127
}
2128
}
2129
}
2130
TEMP_FAILURE_RETRY(close(pubkey_fd));
2131
}
2132
}
2133
2134
/* Lower privileges */
2135
ret_errno = lower_privileges();
2136
if(ret_errno != 0){
2137
errno = ret_errno;
2138
perror_plus("Failed to lower privileges");
2139
}
2140
}
2141
}
2142
2143
/* Remove invalid interface names (except "none") */
2144
{
2145
char *interface = NULL;
2146
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2147
interface))){
2148
if(strcmp(interface, "none") != 0
2149
and if_nametoindex(interface) == 0){
2150
if(interface[0] != '\0'){
2151
fprintf_plus(stderr, "Not using nonexisting interface"
2152
" \"%s\"\n", interface);
2153
}
2154
argz_delete(&mc.interfaces, &mc.interfaces_size, interface);
2155
interface = NULL;
2156
}
2157
}
2158
}
2159
2160
/* Run network hooks */
2161
{
2162
if(mc.interfaces != NULL){
2163
interfaces_hooks = malloc(mc.interfaces_size);
2164
if(interfaces_hooks == NULL){
2165
perror_plus("malloc");
2166
goto end;
2167
}
2168
memcpy(interfaces_hooks, mc.interfaces, mc.interfaces_size);
2169
argz_stringify(interfaces_hooks, mc.interfaces_size, (int)',');
2170
}
2171
run_network_hooks("start", interfaces_hooks != NULL ?
2172
interfaces_hooks : "", delay);
2173
}
2174
2175
if(not debug){
2176
avahi_set_log_function(empty_log);
2177
}
2178
2179
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
2180
from the signal handler */
2181
/* Initialize the pseudo-RNG for Avahi */
2182
srand((unsigned int) time(NULL));
2183
simple_poll = avahi_simple_poll_new();
2184
if(simple_poll == NULL){
2185
fprintf_plus(stderr,
2186
"Avahi: Failed to create simple poll object.\n");
2187
exitcode = EX_UNAVAILABLE;
2188
goto end;
2189
}
2190
2191
sigemptyset(&sigterm_action.sa_mask);
2192
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
2193
if(ret == -1){
2194
perror_plus("sigaddset");
2195
exitcode = EX_OSERR;
2196
goto end;
2197
}
2198
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
2199
if(ret == -1){
2200
perror_plus("sigaddset");
2201
exitcode = EX_OSERR;
2202
goto end;
2203
}
2204
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
2205
if(ret == -1){
2206
perror_plus("sigaddset");
2207
exitcode = EX_OSERR;
2208
goto end;
2209
}
2210
/* Need to check if the handler is SIG_IGN before handling:
2211
| [[info:libc:Initial Signal Actions]] |
2212
| [[info:libc:Basic Signal Handling]] |
2213
*/
2214
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
2215
if(ret == -1){
2216
perror_plus("sigaction");
2217
return EX_OSERR;
2218
}
2219
if(old_sigterm_action.sa_handler != SIG_IGN){
2220
ret = sigaction(SIGINT, &sigterm_action, NULL);
2221
if(ret == -1){
2222
perror_plus("sigaction");
2223
exitcode = EX_OSERR;
2224
goto end;
2225
}
2226
}
2227
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
2228
if(ret == -1){
2229
perror_plus("sigaction");
2230
return EX_OSERR;
2231
}
2232
if(old_sigterm_action.sa_handler != SIG_IGN){
2233
ret = sigaction(SIGHUP, &sigterm_action, NULL);
2234
if(ret == -1){
2235
perror_plus("sigaction");
2236
exitcode = EX_OSERR;
2237
goto end;
2238
}
2239
}
2240
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
2241
if(ret == -1){
2242
perror_plus("sigaction");
2243
return EX_OSERR;
2244
}
2245
if(old_sigterm_action.sa_handler != SIG_IGN){
2246
ret = sigaction(SIGTERM, &sigterm_action, NULL);
2247
if(ret == -1){
2248
perror_plus("sigaction");
2249
exitcode = EX_OSERR;
2250
goto end;
2251
}
2252
}
2253
2254
/* If no interfaces were specified, make a list */
2255
if(mc.interfaces == NULL){
2256
struct dirent **direntries = NULL;
2257
/* Look for any good interfaces */
2258
ret = scandir(sys_class_net, &direntries, good_interface,
2259
alphasort);
2260
if(ret >= 1){
2261
/* Add all found interfaces to interfaces list */
2262
for(int i = 0; i < ret; ++i){
2263
ret_errno = argz_add(&mc.interfaces, &mc.interfaces_size,
2264
direntries[i]->d_name);
2265
if(ret_errno != 0){
2266
errno = ret_errno;
2267
perror_plus("argz_add");
2268
continue;
2269
}
2270
if(debug){
2271
fprintf_plus(stderr, "Will use interface \"%s\"\n",
2272
direntries[i]->d_name);
2273
}
2274
}
2275
free(direntries);
2276
} else {
2277
free(direntries);
2278
fprintf_plus(stderr, "Could not find a network interface\n");
2279
exitcode = EXIT_FAILURE;
2280
goto end;
2281
}
2282
}
2283
2284
/* Bring up interfaces which are down, and remove any "none"s */
2285
{
2286
char *interface = NULL;
2287
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2288
interface))){
2289
/* If interface name is "none", stop bringing up interfaces.
2290
Also remove all instances of "none" from the list */
2291
if(strcmp(interface, "none") == 0){
2292
argz_delete(&mc.interfaces, &mc.interfaces_size,
2293
interface);
2294
interface = NULL;
2295
while((interface = argz_next(mc.interfaces,
2296
mc.interfaces_size, interface))){
2297
if(strcmp(interface, "none") == 0){
2298
argz_delete(&mc.interfaces, &mc.interfaces_size,
2299
interface);
2300
interface = NULL;
2301
}
2302
}
2303
break;
2304
}
2305
bool interface_was_up = interface_is_up(interface);
2306
errno = bring_up_interface(interface, delay);
2307
if(not interface_was_up){
2308
if(errno != 0){
2309
perror_plus("Failed to bring up interface");
2310
} else {
2311
errno = argz_add(&interfaces_to_take_down,
2312
&interfaces_to_take_down_size,
2313
interface);
2314
if(errno != 0){
2315
perror_plus("argz_add");
2316
}
2317
}
2318
}
2319
}
2320
if(debug and (interfaces_to_take_down == NULL)){
2321
fprintf_plus(stderr, "No interfaces were brought up\n");
2322
}
2323
}
2324
2325
/* If we only got one interface, explicitly use only that one */
2326
if(argz_count(mc.interfaces, mc.interfaces_size) == 1){
2327
if(debug){
2328
fprintf_plus(stderr, "Using only interface \"%s\"\n",
2329
mc.interfaces);
2330
}
2331
if_index = (AvahiIfIndex)if_nametoindex(mc.interfaces);
2332
}
2333
2334
if(quit_now){
2335
goto end;
2336
}
2337
2338
ret = init_gnutls_global(pubkey, seckey, &mc);
2339
if(ret == -1){
2340
fprintf_plus(stderr, "init_gnutls_global failed\n");
2341
exitcode = EX_UNAVAILABLE;
2342
goto end;
2343
} else {
2344
gnutls_initialized = true;
2345
}
2346
2347
if(quit_now){
2348
goto end;
2349
}
2350
2351
/* Try /run/tmp before /tmp */
2352
tempdir = mkdtemp(run_tempdir);
2353
if(tempdir == NULL and errno == ENOENT){
2354
if(debug){
2355
fprintf_plus(stderr, "Tempdir %s did not work, trying %s\n",
2356
run_tempdir, old_tempdir);
2357
}
2358
tempdir = mkdtemp(old_tempdir);
2359
}
2360
if(tempdir == NULL){
2361
perror_plus("mkdtemp");
2362
goto end;
2363
}
2364
2365
if(quit_now){
2366
goto end;
2367
}
2368
2369
if(not init_gpgme(pubkey, seckey, tempdir, &mc)){
2370
fprintf_plus(stderr, "init_gpgme failed\n");
2371
exitcode = EX_UNAVAILABLE;
2372
goto end;
2373
} else {
2374
gpgme_initialized = true;
2375
}
2376
2377
if(quit_now){
2378
goto end;
2379
}
2380
2381
if(connect_to != NULL){
2382
/* Connect directly, do not use Zeroconf */
2383
/* (Mainly meant for debugging) */
2384
char *address = strrchr(connect_to, ':');
2385
2386
if(address == NULL){
2387
fprintf_plus(stderr, "No colon in address\n");
2388
exitcode = EX_USAGE;
2389
goto end;
2390
}
2391
2392
if(quit_now){
2393
goto end;
2394
}
2395
2396
in_port_t port;
2397
errno = 0;
2398
tmpmax = strtoimax(address+1, &tmp, 10);
2399
if(errno != 0 or tmp == address+1 or *tmp != '\0'
2400
or tmpmax != (in_port_t)tmpmax){
2401
fprintf_plus(stderr, "Bad port number\n");
2402
exitcode = EX_USAGE;
2403
goto end;
2404
}
2405
2406
if(quit_now){
2407
goto end;
2408
}
2409
2410
port = (in_port_t)tmpmax;
2411
*address = '\0';
2412
/* Colon in address indicates IPv6 */
2413
int af;
2414
if(strchr(connect_to, ':') != NULL){
2415
af = AF_INET6;
2416
/* Accept [] around IPv6 address - see RFC 5952 */
2417
if(connect_to[0] == '[' and address[-1] == ']')
2418
{
2419
connect_to++;
2420
address[-1] = '\0';
2421
}
2422
} else {
2423
af = AF_INET;
2424
}
2425
address = connect_to;
2426
2427
if(quit_now){
2428
goto end;
2429
}
2430
2431
while(not quit_now){
2432
ret = start_mandos_communication(address, port, if_index, af,
2433
&mc);
2434
if(quit_now or ret == 0){
2435
break;
2436
}
2437
if(debug){
2438
fprintf_plus(stderr, "Retrying in %d seconds\n",
2439
(int)retry_interval);
2440
}
2441
sleep((unsigned int)retry_interval);
2442
}
2443
2444
if(not quit_now){
2445
exitcode = EXIT_SUCCESS;
2446
}
2447
2448
goto end;
2449
}
2450
2451
if(quit_now){
2452
goto end;
2453
}
2454
2455
{
2456
AvahiServerConfig config;
2457
/* Do not publish any local Zeroconf records */
2458
avahi_server_config_init(&config);
2459
config.publish_hinfo = 0;
2460
config.publish_addresses = 0;
2461
config.publish_workstation = 0;
2462
config.publish_domain = 0;
2463
2464
/* Allocate a new server */
2465
mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),
2466
&config, NULL, NULL, &ret_errno);
2467
2468
/* Free the Avahi configuration data */
2469
avahi_server_config_free(&config);
2470
}
2471
2472
/* Check if creating the Avahi server object succeeded */
2473
if(mc.server == NULL){
2474
fprintf_plus(stderr, "Failed to create Avahi server: %s\n",
2475
avahi_strerror(ret_errno));
2476
exitcode = EX_UNAVAILABLE;
2477
goto end;
2478
}
2479
2480
if(quit_now){
2481
goto end;
2482
}
2483
2484
/* Create the Avahi service browser */
2485
sb = avahi_s_service_browser_new(mc.server, if_index,
2486
AVAHI_PROTO_UNSPEC, "_mandos._tcp",
2487
NULL, 0, browse_callback,
2488
(void *)&mc);
2489
if(sb == NULL){
2490
fprintf_plus(stderr, "Failed to create service browser: %s\n",
2491
avahi_strerror(avahi_server_errno(mc.server)));
2492
exitcode = EX_UNAVAILABLE;
2493
goto end;
2494
}
2495
2496
if(quit_now){
2497
goto end;
2498
}
2499
2500
/* Run the main loop */
2501
2502
if(debug){
2503
fprintf_plus(stderr, "Starting Avahi loop search\n");
2504
}
2505
2506
ret = avahi_loop_with_timeout(simple_poll,
2507
(int)(retry_interval * 1000), &mc);
2508
if(debug){
2509
fprintf_plus(stderr, "avahi_loop_with_timeout exited %s\n",
2510
(ret == 0) ? "successfully" : "with error");
2511
}
2512
2513
end:
2514
2515
if(debug){
2516
fprintf_plus(stderr, "%s exiting\n", argv[0]);
2517
}
2518
2519
/* Cleanup things */
2520
free(mc.interfaces);
2521
2522
if(sb != NULL)
2523
avahi_s_service_browser_free(sb);
2524
2525
if(mc.server != NULL)
2526
avahi_server_free(mc.server);
2527
2528
if(simple_poll != NULL)
2529
avahi_simple_poll_free(simple_poll);
2530
2531
if(gnutls_initialized){
2532
gnutls_certificate_free_credentials(mc.cred);
2533
gnutls_global_deinit();
2534
gnutls_dh_params_deinit(mc.dh_params);
2535
}
2536
2537
if(gpgme_initialized){
2538
gpgme_release(mc.ctx);
2539
}
2540
2541
/* Cleans up the circular linked list of Mandos servers the client
2542
has seen */
2543
if(mc.current_server != NULL){
2544
mc.current_server->prev->next = NULL;
2545
while(mc.current_server != NULL){
2546
server *next = mc.current_server->next;
2547
free(mc.current_server);
2548
mc.current_server = next;
2549
}
2550
}
2551
2552
/* Re-raise privileges */
2553
{
2554
ret_errno = raise_privileges();
2555
if(ret_errno != 0){
2556
perror_plus("Failed to raise privileges");
2557
} else {
2558
2559
/* Run network hooks */
2560
run_network_hooks("stop", interfaces_hooks != NULL ?
2561
interfaces_hooks : "", delay);
2562
2563
/* Take down the network interfaces which were brought up */
2564
{
2565
char *interface = NULL;
2566
while((interface=argz_next(interfaces_to_take_down,
2567
interfaces_to_take_down_size,
2568
interface))){
2569
ret_errno = take_down_interface(interface);
2570
if(ret_errno != 0){
2571
errno = ret_errno;
2572
perror_plus("Failed to take down interface");
2573
}
2574
}
2575
if(debug and (interfaces_to_take_down == NULL)){
2576
fprintf_plus(stderr, "No interfaces needed to be taken"
2577
" down\n");
2578
}
2579
}
2580
}
2581
2582
ret_errno = lower_privileges_permanently();
2583
if(ret_errno != 0){
2584
perror_plus("Failed to lower privileges permanently");
2585
}
2586
}
2587
2588
free(interfaces_to_take_down);
2589
free(interfaces_hooks);
2590
2591
/* Removes the GPGME temp directory and all files inside */
2592
if(tempdir != NULL){
2593
struct dirent **direntries = NULL;
2594
int tempdir_fd = (int)TEMP_FAILURE_RETRY(open(tempdir, O_RDONLY |
2595
O_NOFOLLOW));
2596
if(tempdir_fd == -1){
2597
perror_plus("open");
2598
} else {
2599
#ifdef __GLIBC__
2600
#if __GLIBC_PREREQ(2, 15)
2601
int numentries = scandirat(tempdir_fd, ".", &direntries,
2602
notdotentries, alphasort);
2603
#else /* not __GLIBC_PREREQ(2, 15) */
2604
int numentries = scandir(tempdir, &direntries, notdotentries,
2605
alphasort);
2606
#endif /* not __GLIBC_PREREQ(2, 15) */
2607
#else /* not __GLIBC__ */
2608
int numentries = scandir(tempdir, &direntries, notdotentries,
2609
alphasort);
2610
#endif /* not __GLIBC__ */
2611
if(numentries > 0){
2612
for(int i = 0; i < numentries; i++){
2613
ret = unlinkat(tempdir_fd, direntries[i]->d_name, 0);
2614
if(ret == -1){
2615
fprintf_plus(stderr, "unlinkat(open(\"%s\", O_RDONLY),"
2616
" \"%s\", 0): %s\n", tempdir,
2617
direntries[i]->d_name, strerror(errno));
2618
}
2619
}
2620
2621
/* need to clean even if 0 because man page doesn't specify */
2622
free(direntries);
2623
if(numentries == -1){
2624
perror_plus("scandir");
2625
}
2626
ret = rmdir(tempdir);
2627
if(ret == -1 and errno != ENOENT){
2628
perror_plus("rmdir");
2629
}
2630
}
2631
TEMP_FAILURE_RETRY(close(tempdir_fd));
2632
}
2633
}
2634
2635
if(quit_now){
2636
sigemptyset(&old_sigterm_action.sa_mask);
2637
old_sigterm_action.sa_handler = SIG_DFL;
2638
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
2639
&old_sigterm_action,
2640
NULL));
2641
if(ret == -1){
2642
perror_plus("sigaction");
2643
}
2644
do {
2645
ret = raise(signal_received);
2646
} while(ret != 0 and errno == EINTR);
2647
if(ret != 0){
2648
perror_plus("raise");
2649
abort();
2650
}
2651
TEMP_FAILURE_RETRY(pause());
2652
}
2653
2654
return exitcode;
2655
}
Loggerhead is a web-based interface for Breezy
Version: 2.0.2.dev0