9
9
* "browse_callback", and parts of "main".
11
11
* Everything else is
12
* Copyright © 2008,2009 Teddy Hogeborn
13
* Copyright © 2008,2009 Björn Påhlsson
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.
20
* This program is distributed in the hope that it will be useful, but
12
* Copyright © 2008-2018 Teddy Hogeborn
13
* Copyright © 2008-2018 Björn Påhlsson
15
* This file is part of Mandos.
17
* Mandos is free software: you can redistribute it and/or modify it
18
* under the terms of the GNU General Public License as published by
19
* the Free Software Foundation, either version 3 of the License, or
20
* (at your option) any later version.
22
* Mandos is distributed in the hope that it will be useful, but
21
23
* WITHOUT ANY WARRANTY; without even the implied warranty of
22
24
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
23
25
* General Public License for more details.
25
27
* 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
* along with Mandos. If not, see <http://www.gnu.org/licenses/>.
29
* Contact the authors at <mandos@fukt.bsnet.se>.
30
* Contact the authors at <mandos@recompile.se>.
32
33
/* Needed by GPGME, specifically gpgme_data_seek() */
33
34
#ifndef _LARGEFILE_SOURCE
34
35
#define _LARGEFILE_SOURCE
36
#endif /* not _LARGEFILE_SOURCE */
36
37
#ifndef _FILE_OFFSET_BITS
37
38
#define _FILE_OFFSET_BITS 64
39
#endif /* not _FILE_OFFSET_BITS */
40
41
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
42
43
#include <stdio.h> /* fprintf(), stderr, fwrite(),
43
stdout, ferror(), remove() */
44
#include <stdint.h> /* uint16_t, uint32_t */
45
#include <stdint.h> /* uint16_t, uint32_t, intptr_t */
45
46
#include <stddef.h> /* NULL, size_t, ssize_t */
46
#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
47
#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),
48
49
#include <stdbool.h> /* bool, false, true */
49
#include <string.h> /* memset(), strcmp(), strlen(),
50
strerror(), asprintf(), strcpy() */
50
#include <string.h> /* strcmp(), strlen(), strerror(),
51
asprintf(), strncpy(), strsignal()
51
53
#include <sys/ioctl.h> /* ioctl */
52
54
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
53
55
sockaddr_in6, PF_INET6,
54
56
SOCK_STREAM, uid_t, gid_t, open(),
56
#include <sys/stat.h> /* open() */
58
#include <sys/stat.h> /* open(), S_ISREG */
57
59
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
58
inet_pton(), connect() */
59
#include <fcntl.h> /* open() */
60
inet_pton(), connect(),
62
#include <fcntl.h> /* open(), unlinkat(), AT_REMOVEDIR */
60
63
#include <dirent.h> /* opendir(), struct dirent, readdir()
62
65
#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,
64
#include <assert.h> /* assert() */
65
#include <errno.h> /* perror(), errno */
66
#include <time.h> /* nanosleep(), time() */
67
#include <errno.h> /* perror(), errno, EINTR, EINVAL,
68
EAI_SYSTEM, ENETUNREACH,
69
EHOSTUNREACH, ECONNREFUSED, EPROTO,
70
EIO, ENOENT, ENXIO, ENOMEM, EISDIR,
72
program_invocation_short_name */
73
#include <time.h> /* nanosleep(), time(), sleep() */
67
74
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
68
75
SIOCSIFFLAGS, if_indextoname(),
69
76
if_nametoindex(), IF_NAMESIZE */
120
139
#define PATHDIR "/conf/conf.d/mandos"
121
140
#define SECKEY "seckey.txt"
122
141
#define PUBKEY "pubkey.txt"
142
#define HOOKDIR "/lib/mandos/network-hooks.d"
124
144
bool debug = false;
125
145
static const char mandos_protocol_version[] = "1";
126
146
const char *argp_program_version = "mandos-client " VERSION;
127
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
147
const char *argp_program_bug_address = "<mandos@recompile.se>";
148
static const char sys_class_net[] = "/sys/class/net";
149
char *connect_to = NULL;
150
const char *hookdir = HOOKDIR;
155
/* Doubly linked list that need to be circularly linked when used */
156
typedef struct server{
159
AvahiIfIndex if_index;
161
struct timespec last_seen;
129
166
/* Used for passing in values through the Avahi callback functions */
131
AvahiSimplePoll *simple_poll;
132
168
AvahiServer *server;
133
169
gnutls_certificate_credentials_t cred;
134
170
unsigned int dh_bits;
135
171
gnutls_dh_params_t dh_params;
136
172
const char *priority;
174
server *current_server;
176
size_t interfaces_size;
138
177
} mandos_context;
140
/* global context so signal handler can reach it*/
141
mandos_context mc = { .simple_poll = NULL, .server = NULL,
142
.dh_bits = 1024, .priority = "SECURE256"
143
":!CTYPE-X.509:+CTYPE-OPENPGP" };
179
/* global so signal handler can reach it*/
180
AvahiSimplePoll *simple_poll;
182
sig_atomic_t quit_now = 0;
183
int signal_received = 0;
185
/* Function to use when printing errors */
186
void perror_plus(const char *print_text){
188
fprintf(stderr, "Mandos plugin %s: ",
189
program_invocation_short_name);
194
__attribute__((format (gnu_printf, 2, 3), nonnull))
195
int fprintf_plus(FILE *stream, const char *format, ...){
197
va_start (ap, format);
199
TEMP_FAILURE_RETRY(fprintf(stream, "Mandos plugin %s: ",
200
program_invocation_short_name));
201
return (int)TEMP_FAILURE_RETRY(vfprintf(stream, format, ap));
146
205
* Make additional room in "buffer" for at least BUFFER_SIZE more
147
206
* bytes. "buffer_capacity" is how much is currently allocated,
148
207
* "buffer_length" is how much is already used.
209
__attribute__((nonnull, warn_unused_result))
150
210
size_t incbuffer(char **buffer, size_t buffer_length,
151
size_t buffer_capacity){
211
size_t buffer_capacity){
152
212
if(buffer_length + BUFFER_SIZE > buffer_capacity){
153
*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
213
char *new_buf = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
215
int old_errno = errno;
157
222
buffer_capacity += BUFFER_SIZE;
159
224
return buffer_capacity;
227
/* Add server to set of servers to retry periodically */
228
__attribute__((nonnull, warn_unused_result))
229
bool add_server(const char *ip, in_port_t port, AvahiIfIndex if_index,
230
int af, server **current_server){
232
server *new_server = malloc(sizeof(server));
233
if(new_server == NULL){
234
perror_plus("malloc");
237
*new_server = (server){ .ip = strdup(ip),
239
.if_index = if_index,
241
if(new_server->ip == NULL){
242
perror_plus("strdup");
246
ret = clock_gettime(CLOCK_MONOTONIC, &(new_server->last_seen));
248
perror_plus("clock_gettime");
250
#pragma GCC diagnostic push
251
#pragma GCC diagnostic ignored "-Wcast-qual"
253
free((char *)(new_server->ip));
255
#pragma GCC diagnostic pop
260
/* Special case of first server */
261
if(*current_server == NULL){
262
new_server->next = new_server;
263
new_server->prev = new_server;
264
*current_server = new_server;
266
/* Place the new server last in the list */
267
new_server->next = *current_server;
268
new_server->prev = (*current_server)->prev;
269
new_server->prev->next = new_server;
270
(*current_server)->prev = new_server;
163
276
* Initialize GPGME.
165
static bool init_gpgme(const char *seckey,
166
const char *pubkey, const char *tempdir){
278
__attribute__((nonnull, warn_unused_result))
279
static bool init_gpgme(const char * const seckey,
280
const char * const pubkey,
281
const char * const tempdir,
168
283
gpgme_error_t rc;
169
284
gpgme_engine_info_t engine_info;
173
287
* Helper function to insert pub and seckey to the engine keyring.
175
bool import_key(const char *filename){
289
bool import_key(const char * const filename){
177
292
gpgme_data_t pgp_data;
179
294
fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
185
300
rc = gpgme_data_new_from_fd(&pgp_data, fd);
186
301
if(rc != GPG_ERR_NO_ERROR){
187
fprintf(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
188
gpgme_strsource(rc), gpgme_strerror(rc));
302
fprintf_plus(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
303
gpgme_strsource(rc), gpgme_strerror(rc));
192
rc = gpgme_op_import(mc.ctx, pgp_data);
307
rc = gpgme_op_import(mc->ctx, pgp_data);
193
308
if(rc != GPG_ERR_NO_ERROR){
194
fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
195
gpgme_strsource(rc), gpgme_strerror(rc));
309
fprintf_plus(stderr, "bad gpgme_op_import: %s: %s\n",
310
gpgme_strsource(rc), gpgme_strerror(rc));
199
ret = (int)TEMP_FAILURE_RETRY(close(fd));
316
perror_plus("close");
203
318
gpgme_data_release(pgp_data);
208
fprintf(stderr, "Initializing GPGME\n");
323
fprintf_plus(stderr, "Initializing GPGME\n");
212
327
gpgme_check_version(NULL);
213
328
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
214
329
if(rc != GPG_ERR_NO_ERROR){
215
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
216
gpgme_strsource(rc), gpgme_strerror(rc));
330
fprintf_plus(stderr, "bad gpgme_engine_check_version: %s: %s\n",
331
gpgme_strsource(rc), gpgme_strerror(rc));
220
/* Set GPGME home directory for the OpenPGP engine only */
335
/* Set GPGME home directory for the OpenPGP engine only */
221
336
rc = gpgme_get_engine_info(&engine_info);
222
337
if(rc != GPG_ERR_NO_ERROR){
223
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
224
gpgme_strsource(rc), gpgme_strerror(rc));
338
fprintf_plus(stderr, "bad gpgme_get_engine_info: %s: %s\n",
339
gpgme_strsource(rc), gpgme_strerror(rc));
227
342
while(engine_info != NULL){
266
385
ssize_t plaintext_length = 0;
269
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
388
fprintf_plus(stderr, "Trying to decrypt OpenPGP data\n");
272
391
/* Create new GPGME data buffer from memory cryptotext */
273
392
rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,
275
394
if(rc != GPG_ERR_NO_ERROR){
276
fprintf(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
277
gpgme_strsource(rc), gpgme_strerror(rc));
395
fprintf_plus(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
396
gpgme_strsource(rc), gpgme_strerror(rc));
281
400
/* Create new empty GPGME data buffer for the plaintext */
282
401
rc = gpgme_data_new(&dh_plain);
283
402
if(rc != GPG_ERR_NO_ERROR){
284
fprintf(stderr, "bad gpgme_data_new: %s: %s\n",
285
gpgme_strsource(rc), gpgme_strerror(rc));
403
fprintf_plus(stderr, "Mandos plugin mandos-client: "
404
"bad gpgme_data_new: %s: %s\n",
405
gpgme_strsource(rc), gpgme_strerror(rc));
286
406
gpgme_data_release(dh_crypto);
290
410
/* Decrypt data from the cryptotext data buffer to the plaintext
292
rc = gpgme_op_decrypt(mc.ctx, dh_crypto, dh_plain);
412
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
293
413
if(rc != GPG_ERR_NO_ERROR){
294
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
295
gpgme_strsource(rc), gpgme_strerror(rc));
414
fprintf_plus(stderr, "bad gpgme_op_decrypt: %s: %s\n",
415
gpgme_strsource(rc), gpgme_strerror(rc));
296
416
plaintext_length = -1;
298
418
gpgme_decrypt_result_t result;
299
result = gpgme_op_decrypt_result(mc.ctx);
419
result = gpgme_op_decrypt_result(mc->ctx);
300
420
if(result == NULL){
301
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
421
fprintf_plus(stderr, "gpgme_op_decrypt_result failed\n");
303
fprintf(stderr, "Unsupported algorithm: %s\n",
304
result->unsupported_algorithm);
305
fprintf(stderr, "Wrong key usage: %u\n",
306
result->wrong_key_usage);
423
fprintf_plus(stderr, "Unsupported algorithm: %s\n",
424
result->unsupported_algorithm);
425
fprintf_plus(stderr, "Wrong key usage: %u\n",
426
result->wrong_key_usage);
307
427
if(result->file_name != NULL){
308
fprintf(stderr, "File name: %s\n", result->file_name);
428
fprintf_plus(stderr, "File name: %s\n", result->file_name);
310
430
gpgme_recipient_t recipient;
311
431
recipient = result->recipients;
312
432
while(recipient != NULL){
313
fprintf(stderr, "Public key algorithm: %s\n",
314
gpgme_pubkey_algo_name(recipient->pubkey_algo));
315
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
316
fprintf(stderr, "Secret key available: %s\n",
317
recipient->status == GPG_ERR_NO_SECKEY
433
fprintf_plus(stderr, "Public key algorithm: %s\n",
434
gpgme_pubkey_algo_name
435
(recipient->pubkey_algo));
436
fprintf_plus(stderr, "Key ID: %s\n", recipient->keyid);
437
fprintf_plus(stderr, "Secret key available: %s\n",
438
recipient->status == GPG_ERR_NO_SECKEY
319
440
recipient = recipient->next;
418
542
/* OpenPGP credentials */
419
gnutls_certificate_allocate_credentials(&mc.cred);
543
ret = gnutls_certificate_allocate_credentials(&mc->cred);
420
544
if(ret != GNUTLS_E_SUCCESS){
421
fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning
425
safer_gnutls_strerror(ret));
426
gnutls_global_deinit();
545
fprintf_plus(stderr, "GnuTLS memory error: %s\n",
546
safer_gnutls_strerror(ret));
431
fprintf(stderr, "Attempting to use OpenPGP public key %s and"
432
" secret key %s as GnuTLS credentials\n", pubkeyfilename,
551
fprintf_plus(stderr, "Attempting to use OpenPGP public key %s and"
552
" secret key %s as GnuTLS credentials\n",
436
557
ret = gnutls_certificate_set_openpgp_key_file
437
(mc.cred, pubkeyfilename, seckeyfilename,
558
(mc->cred, pubkeyfilename, seckeyfilename,
438
559
GNUTLS_OPENPGP_FMT_BASE64);
439
560
if(ret != GNUTLS_E_SUCCESS){
441
"Error[%d] while reading the OpenPGP key pair ('%s',"
442
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
443
fprintf(stderr, "The GnuTLS error is: %s\n",
444
safer_gnutls_strerror(ret));
562
"Error[%d] while reading the OpenPGP key pair ('%s',"
563
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
564
fprintf_plus(stderr, "The GnuTLS error is: %s\n",
565
safer_gnutls_strerror(ret));
448
569
/* GnuTLS server initialization */
449
ret = gnutls_dh_params_init(&mc.dh_params);
450
if(ret != GNUTLS_E_SUCCESS){
451
fprintf(stderr, "Error in GnuTLS DH parameter initialization:"
452
" %s\n", safer_gnutls_strerror(ret));
455
ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);
456
if(ret != GNUTLS_E_SUCCESS){
457
fprintf(stderr, "Error in GnuTLS prime generation: %s\n",
458
safer_gnutls_strerror(ret));
462
gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);
570
ret = gnutls_dh_params_init(&mc->dh_params);
571
if(ret != GNUTLS_E_SUCCESS){
572
fprintf_plus(stderr, "Error in GnuTLS DH parameter"
573
" initialization: %s\n",
574
safer_gnutls_strerror(ret));
577
/* If a Diffie-Hellman parameters file was given, try to use it */
578
if(dhparamsfilename != NULL){
579
gnutls_datum_t params = { .data = NULL, .size = 0 };
581
int dhpfile = open(dhparamsfilename, O_RDONLY);
584
dhparamsfilename = NULL;
587
size_t params_capacity = 0;
589
params_capacity = incbuffer((char **)¶ms.data,
591
(size_t)params_capacity);
592
if(params_capacity == 0){
593
perror_plus("incbuffer");
596
dhparamsfilename = NULL;
599
ssize_t bytes_read = read(dhpfile,
600
params.data + params.size,
606
/* check bytes_read for failure */
611
dhparamsfilename = NULL;
614
params.size += (unsigned int)bytes_read;
616
ret = close(dhpfile);
618
perror_plus("close");
620
if(params.data == NULL){
621
dhparamsfilename = NULL;
623
if(dhparamsfilename == NULL){
626
ret = gnutls_dh_params_import_pkcs3(mc->dh_params, ¶ms,
627
GNUTLS_X509_FMT_PEM);
628
if(ret != GNUTLS_E_SUCCESS){
629
fprintf_plus(stderr, "Failed to parse DH parameters in file"
630
" \"%s\": %s\n", dhparamsfilename,
631
safer_gnutls_strerror(ret));
632
dhparamsfilename = NULL;
637
if(dhparamsfilename == NULL){
638
if(mc->dh_bits == 0){
639
/* Find out the optimal number of DH bits */
640
/* Try to read the private key file */
641
gnutls_datum_t buffer = { .data = NULL, .size = 0 };
643
int secfile = open(seckeyfilename, O_RDONLY);
648
size_t buffer_capacity = 0;
650
buffer_capacity = incbuffer((char **)&buffer.data,
652
(size_t)buffer_capacity);
653
if(buffer_capacity == 0){
654
perror_plus("incbuffer");
659
ssize_t bytes_read = read(secfile,
660
buffer.data + buffer.size,
666
/* check bytes_read for failure */
673
buffer.size += (unsigned int)bytes_read;
677
/* If successful, use buffer to parse private key */
678
gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;
679
if(buffer.data != NULL){
681
gnutls_openpgp_privkey_t privkey = NULL;
682
ret = gnutls_openpgp_privkey_init(&privkey);
683
if(ret != GNUTLS_E_SUCCESS){
684
fprintf_plus(stderr, "Error initializing OpenPGP key"
686
safer_gnutls_strerror(ret));
690
ret = gnutls_openpgp_privkey_import
691
(privkey, &buffer, GNUTLS_OPENPGP_FMT_BASE64, "", 0);
692
if(ret != GNUTLS_E_SUCCESS){
693
fprintf_plus(stderr, "Error importing OpenPGP key : %s",
694
safer_gnutls_strerror(ret));
700
/* Use private key to suggest an appropriate
702
sec_param = gnutls_openpgp_privkey_sec_param(privkey);
703
gnutls_openpgp_privkey_deinit(privkey);
705
fprintf_plus(stderr, "This OpenPGP key implies using"
706
" a GnuTLS security parameter \"%s\".\n",
707
safe_string(gnutls_sec_param_get_name
713
if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){
714
/* Err on the side of caution */
715
sec_param = GNUTLS_SEC_PARAM_ULTRA;
717
fprintf_plus(stderr, "Falling back to security parameter"
719
safe_string(gnutls_sec_param_get_name
724
uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);
728
fprintf_plus(stderr, "A \"%s\" GnuTLS security parameter"
729
" implies %u DH bits; using that.\n",
730
safe_string(gnutls_sec_param_get_name
735
fprintf_plus(stderr, "Failed to get implied number of DH"
736
" bits for security parameter \"%s\"): %s\n",
737
safe_string(gnutls_sec_param_get_name
739
safer_gnutls_strerror(ret));
743
fprintf_plus(stderr, "DH bits explicitly set to %u\n",
746
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
747
if(ret != GNUTLS_E_SUCCESS){
748
fprintf_plus(stderr, "Error in GnuTLS prime generation (%u"
749
" bits): %s\n", mc->dh_bits,
750
safer_gnutls_strerror(ret));
754
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
468
gnutls_certificate_free_credentials(mc.cred);
469
gnutls_global_deinit();
470
gnutls_dh_params_deinit(mc.dh_params);
760
gnutls_certificate_free_credentials(mc->cred);
761
gnutls_dh_params_deinit(mc->dh_params);
474
static int init_gnutls_session(gnutls_session_t *session){
765
__attribute__((nonnull, warn_unused_result))
766
static int init_gnutls_session(gnutls_session_t *session,
476
769
/* GnuTLS session creation */
477
ret = gnutls_init(session, GNUTLS_SERVER);
771
ret = gnutls_init(session, GNUTLS_SERVER);
775
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
478
776
if(ret != GNUTLS_E_SUCCESS){
479
fprintf(stderr, "Error in GnuTLS session initialization: %s\n",
480
safer_gnutls_strerror(ret));
778
"Error in GnuTLS session initialization: %s\n",
779
safer_gnutls_strerror(ret));
485
ret = gnutls_priority_set_direct(*session, mc.priority, &err);
785
ret = gnutls_priority_set_direct(*session, mc->priority, &err);
787
gnutls_deinit(*session);
790
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
486
791
if(ret != GNUTLS_E_SUCCESS){
487
fprintf(stderr, "Syntax error at: %s\n", err);
488
fprintf(stderr, "GnuTLS error: %s\n",
489
safer_gnutls_strerror(ret));
792
fprintf_plus(stderr, "Syntax error at: %s\n", err);
793
fprintf_plus(stderr, "GnuTLS error: %s\n",
794
safer_gnutls_strerror(ret));
490
795
gnutls_deinit(*session);
495
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
801
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
804
gnutls_deinit(*session);
807
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
497
808
if(ret != GNUTLS_E_SUCCESS){
498
fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
499
safer_gnutls_strerror(ret));
809
fprintf_plus(stderr, "Error setting GnuTLS credentials: %s\n",
810
safer_gnutls_strerror(ret));
500
811
gnutls_deinit(*session);
504
815
/* ignore client certificate if any. */
505
gnutls_certificate_server_set_request(*session,
508
gnutls_dh_set_prime_bits(*session, mc.dh_bits);
816
gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);
514
822
static void empty_log(__attribute__((unused)) AvahiLogLevel level,
515
823
__attribute__((unused)) const char *txt){}
825
/* Set effective uid to 0, return errno */
826
__attribute__((warn_unused_result))
827
int raise_privileges(void){
828
int old_errno = errno;
830
if(seteuid(0) == -1){
837
/* Set effective and real user ID to 0. Return errno. */
838
__attribute__((warn_unused_result))
839
int raise_privileges_permanently(void){
840
int old_errno = errno;
841
int ret = raise_privileges();
853
/* Set effective user ID to unprivileged saved user ID */
854
__attribute__((warn_unused_result))
855
int lower_privileges(void){
856
int old_errno = errno;
858
if(seteuid(uid) == -1){
865
/* Lower privileges permanently */
866
__attribute__((warn_unused_result))
867
int lower_privileges_permanently(void){
868
int old_errno = errno;
870
if(setuid(uid) == -1){
877
/* Helper function to add_local_route() and delete_local_route() */
878
__attribute__((nonnull, warn_unused_result))
879
static bool add_delete_local_route(const bool add,
881
AvahiIfIndex if_index){
883
char helper[] = "mandos-client-iprouteadddel";
884
char add_arg[] = "add";
885
char delete_arg[] = "delete";
886
char debug_flag[] = "--debug";
887
char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");
888
if(pluginhelperdir == NULL){
890
fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"
891
" variable not set; cannot run helper\n");
896
char interface[IF_NAMESIZE];
897
if(if_indextoname((unsigned int)if_index, interface) == NULL){
898
perror_plus("if_indextoname");
902
int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));
904
perror_plus("open(\"/dev/null\", O_RDONLY)");
910
/* Raise privileges */
911
errno = raise_privileges_permanently();
913
perror_plus("Failed to raise privileges");
914
/* _exit(EX_NOPERM); */
920
perror_plus("setgid");
923
/* Reset supplementary groups */
925
ret = setgroups(0, NULL);
927
perror_plus("setgroups");
931
ret = dup2(devnull, STDIN_FILENO);
933
perror_plus("dup2(devnull, STDIN_FILENO)");
936
ret = close(devnull);
938
perror_plus("close");
941
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
943
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
946
int helperdir_fd = (int)TEMP_FAILURE_RETRY(open(pluginhelperdir,
951
if(helperdir_fd == -1){
953
_exit(EX_UNAVAILABLE);
955
int helper_fd = (int)TEMP_FAILURE_RETRY(openat(helperdir_fd,
958
perror_plus("openat");
960
_exit(EX_UNAVAILABLE);
964
#pragma GCC diagnostic push
965
#pragma GCC diagnostic ignored "-Wcast-qual"
967
if(fexecve(helper_fd, (char *const [])
968
{ helper, add ? add_arg : delete_arg, (char *)address,
969
interface, debug ? debug_flag : NULL, NULL },
972
#pragma GCC diagnostic pop
974
perror_plus("fexecve");
986
pret = waitpid(pid, &status, 0);
987
if(pret == -1 and errno == EINTR and quit_now){
988
int errno_raising = 0;
989
if((errno = raise_privileges()) != 0){
990
errno_raising = errno;
991
perror_plus("Failed to raise privileges in order to"
992
" kill helper program");
994
if(kill(pid, SIGTERM) == -1){
997
if((errno_raising == 0) and (errno = lower_privileges()) != 0){
998
perror_plus("Failed to lower privileges after killing"
1003
} while(pret == -1 and errno == EINTR);
1005
perror_plus("waitpid");
1008
if(WIFEXITED(status)){
1009
if(WEXITSTATUS(status) != 0){
1010
fprintf_plus(stderr, "Error: iprouteadddel exited"
1011
" with status %d\n", WEXITSTATUS(status));
1016
if(WIFSIGNALED(status)){
1017
fprintf_plus(stderr, "Error: iprouteadddel died by"
1018
" signal %d\n", WTERMSIG(status));
1021
fprintf_plus(stderr, "Error: iprouteadddel crashed\n");
1025
__attribute__((nonnull, warn_unused_result))
1026
static bool add_local_route(const char *address,
1027
AvahiIfIndex if_index){
1029
fprintf_plus(stderr, "Adding route to %s\n", address);
1031
return add_delete_local_route(true, address, if_index);
1034
__attribute__((nonnull, warn_unused_result))
1035
static bool delete_local_route(const char *address,
1036
AvahiIfIndex if_index){
1038
fprintf_plus(stderr, "Removing route to %s\n", address);
1040
return add_delete_local_route(false, address, if_index);
517
1043
/* Called when a Mandos server is found */
518
static int start_mandos_communication(const char *ip, uint16_t port,
1044
__attribute__((nonnull, warn_unused_result))
1045
static int start_mandos_communication(const char *ip, in_port_t port,
519
1046
AvahiIfIndex if_index,
1047
int af, mandos_context *mc){
1048
int ret, tcp_sd = -1;
524
struct sockaddr_in in;
525
struct sockaddr_in6 in6;
1050
struct sockaddr_storage to;
527
1051
char *buffer = NULL;
528
char *decrypted_buffer;
1052
char *decrypted_buffer = NULL;
529
1053
size_t buffer_length = 0;
530
1054
size_t buffer_capacity = 0;
531
ssize_t decrypted_buffer_size;
534
1057
gnutls_session_t session;
535
1058
int pf; /* Protocol family */
1059
bool route_added = false;
545
fprintf(stderr, "Bad address family: %d\n", af);
1076
fprintf_plus(stderr, "Bad address family: %d\n", af);
549
ret = init_gnutls_session(&session);
1081
/* If the interface is specified and we have a list of interfaces */
1082
if(if_index != AVAHI_IF_UNSPEC and mc->interfaces != NULL){
1083
/* Check if the interface is one of the interfaces we are using */
1086
char *interface = NULL;
1087
while((interface = argz_next(mc->interfaces,
1088
mc->interfaces_size,
1090
if(if_nametoindex(interface) == (unsigned int)if_index){
1097
/* This interface does not match any in the list, so we don't
1098
connect to the server */
1100
char interface[IF_NAMESIZE];
1101
if(if_indextoname((unsigned int)if_index, interface) == NULL){
1102
perror_plus("if_indextoname");
1104
fprintf_plus(stderr, "Skipping server on non-used interface"
1106
if_indextoname((unsigned int)if_index,
1114
ret = init_gnutls_session(&session, mc);
555
fprintf(stderr, "Setting up a TCP connection to %s, port %" PRIu16
1120
fprintf_plus(stderr, "Setting up a TCP connection to %s, port %"
1121
PRIuMAX "\n", ip, (uintmax_t)port);
559
tcp_sd = socket(pf, SOCK_STREAM, 0);
1124
tcp_sd = socket(pf, SOCK_STREAM | SOCK_CLOEXEC, 0);
565
memset(&to, 0, sizeof(to));
1127
perror_plus("socket");
566
1137
if(af == AF_INET6){
567
to.in6.sin6_family = (sa_family_t)af;
568
ret = inet_pton(af, ip, &to.in6.sin6_addr);
1138
struct sockaddr_in6 *to6 = (struct sockaddr_in6 *)&to;
1139
*to6 = (struct sockaddr_in6){ .sin6_family = (sa_family_t)af };
1140
ret = inet_pton(af, ip, &to6->sin6_addr);
569
1141
} else { /* IPv4 */
570
to.in.sin_family = (sa_family_t)af;
571
ret = inet_pton(af, ip, &to.in.sin_addr);
1142
struct sockaddr_in *to4 = (struct sockaddr_in *)&to;
1143
*to4 = (struct sockaddr_in){ .sin_family = (sa_family_t)af };
1144
ret = inet_pton(af, ip, &to4->sin_addr);
1148
perror_plus("inet_pton");
578
fprintf(stderr, "Bad address: %s\n", ip);
1154
fprintf_plus(stderr, "Bad address: %s\n", ip);
581
1158
if(af == AF_INET6){
582
to.in6.sin6_port = htons(port); /* Spurious warnings from
584
-Wunreachable-code */
586
if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */
587
(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower and
1159
((struct sockaddr_in6 *)&to)->sin6_port = htons(port);
1160
if(IN6_IS_ADDR_LINKLOCAL
1161
(&((struct sockaddr_in6 *)&to)->sin6_addr)){
589
1162
if(if_index == AVAHI_IF_UNSPEC){
590
fprintf(stderr, "An IPv6 link-local address is incomplete"
591
" without a network interface\n");
1163
fprintf_plus(stderr, "An IPv6 link-local address is"
1164
" incomplete without a network interface\n");
594
1168
/* Set the network interface number as scope */
595
to.in6.sin6_scope_id = (uint32_t)if_index;
1169
((struct sockaddr_in6 *)&to)->sin6_scope_id = (uint32_t)if_index;
598
to.in.sin_port = htons(port); /* Spurious warnings from
600
-Wunreachable-code */
1172
((struct sockaddr_in *)&to)->sin_port = htons(port);
604
1181
if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){
605
1182
char interface[IF_NAMESIZE];
606
1183
if(if_indextoname((unsigned int)if_index, interface) == NULL){
607
perror("if_indextoname");
1184
perror_plus("if_indextoname");
609
fprintf(stderr, "Connection to: %s%%%s, port %" PRIu16 "\n",
610
ip, interface, port);
1186
fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIuMAX
1187
"\n", ip, interface, (uintmax_t)port);
613
fprintf(stderr, "Connection to: %s, port %" PRIu16 "\n", ip,
1190
fprintf_plus(stderr, "Connection to: %s, port %" PRIuMAX "\n",
1191
ip, (uintmax_t)port);
616
1193
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
617
1194
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
620
pcret = inet_ntop(af, &(to.in6.sin6_addr), addrstr,
623
pcret = inet_ntop(af, &(to.in.sin_addr), addrstr,
629
if(strcmp(addrstr, ip) != 0){
630
fprintf(stderr, "Canonical address form: %s\n", addrstr);
636
ret = connect(tcp_sd, &to.in6, sizeof(to));
638
ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */
1196
ret = getnameinfo((struct sockaddr *)&to,
1197
sizeof(struct sockaddr_in6),
1198
addrstr, sizeof(addrstr), NULL, 0,
1201
ret = getnameinfo((struct sockaddr *)&to,
1202
sizeof(struct sockaddr_in),
1203
addrstr, sizeof(addrstr), NULL, 0,
1206
if(ret == EAI_SYSTEM){
1207
perror_plus("getnameinfo");
1208
} else if(ret != 0) {
1209
fprintf_plus(stderr, "getnameinfo: %s", gai_strerror(ret));
1210
} else if(strcmp(addrstr, ip) != 0){
1211
fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);
1222
ret = connect(tcp_sd, (struct sockaddr *)&to,
1223
sizeof(struct sockaddr_in6));
1225
ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */
1226
sizeof(struct sockaddr_in));
1229
if(((errno == ENETUNREACH) or (errno == EHOSTUNREACH))
1230
and if_index != AVAHI_IF_UNSPEC
1231
and connect_to == NULL
1232
and not route_added and
1233
((af == AF_INET6 and not
1234
IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)
1236
or (af == AF_INET and
1237
/* Not a a IPv4LL address */
1238
(ntohl(((struct sockaddr_in *)&to)->sin_addr.s_addr)
1239
& 0xFFFF0000L) != 0xA9FE0000L))){
1240
/* Work around Avahi bug - Avahi does not announce link-local
1241
addresses if it has a global address, so local hosts with
1242
*only* a link-local address (e.g. Mandos clients) cannot
1243
connect to a Mandos server announced by Avahi on a server
1244
host with a global address. Work around this by retrying
1245
with an explicit route added with the server's address.
1247
Avahi bug reference:
1248
https://lists.freedesktop.org/archives/avahi/2010-February/001833.html
1249
https://bugs.debian.org/587961
1252
fprintf_plus(stderr, "Mandos server unreachable, trying"
1256
route_added = add_local_route(ip, if_index);
1262
if(errno != ECONNREFUSED or debug){
1264
perror_plus("connect");
645
1277
const char *out = mandos_protocol_version;
875
1616
case AVAHI_BROWSER_ALL_FOR_NOW:
876
1617
case AVAHI_BROWSER_CACHE_EXHAUSTED:
878
fprintf(stderr, "No Mandos server found, still searching...\n");
1619
fprintf_plus(stderr, "No Mandos server found, still"
884
/* stop main loop after sigterm has been called */
885
static void handle_sigterm(__attribute__((unused)) int sig){
1626
/* Signal handler that stops main loop after SIGTERM */
1627
static void handle_sigterm(int sig){
890
int old_errno = errno;
891
if(mc.simple_poll != NULL){
892
avahi_simple_poll_quit(mc.simple_poll);
1632
signal_received = sig;
1633
int old_errno = errno;
1634
/* set main loop to exit */
1635
if(simple_poll != NULL){
1636
avahi_simple_poll_quit(simple_poll);
1641
__attribute__((nonnull, warn_unused_result))
1642
bool get_flags(const char *ifname, struct ifreq *ifr){
1646
int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1649
perror_plus("socket");
1653
strncpy(ifr->ifr_name, ifname, IF_NAMESIZE);
1654
ifr->ifr_name[IF_NAMESIZE-1] = '\0'; /* NUL terminate */
1655
ret = ioctl(s, SIOCGIFFLAGS, ifr);
1659
perror_plus("ioctl SIOCGIFFLAGS");
1662
if((close(s) == -1) and debug){
1664
perror_plus("close");
1669
if((close(s) == -1) and debug){
1671
perror_plus("close");
1677
__attribute__((nonnull, warn_unused_result))
1678
bool good_flags(const char *ifname, const struct ifreq *ifr){
1680
/* Reject the loopback device */
1681
if(ifr->ifr_flags & IFF_LOOPBACK){
1683
fprintf_plus(stderr, "Rejecting loopback interface \"%s\"\n",
1688
/* Accept point-to-point devices only if connect_to is specified */
1689
if(connect_to != NULL and (ifr->ifr_flags & IFF_POINTOPOINT)){
1691
fprintf_plus(stderr, "Accepting point-to-point interface"
1692
" \"%s\"\n", ifname);
1696
/* Otherwise, reject non-broadcast-capable devices */
1697
if(not (ifr->ifr_flags & IFF_BROADCAST)){
1699
fprintf_plus(stderr, "Rejecting non-broadcast interface"
1700
" \"%s\"\n", ifname);
1704
/* Reject non-ARP interfaces (including dummy interfaces) */
1705
if(ifr->ifr_flags & IFF_NOARP){
1707
fprintf_plus(stderr, "Rejecting non-ARP interface \"%s\"\n",
1713
/* Accept this device */
1715
fprintf_plus(stderr, "Interface \"%s\" is good\n", ifname);
1721
* This function determines if a directory entry in /sys/class/net
1722
* corresponds to an acceptable network device.
1723
* (This function is passed to scandir(3) as a filter function.)
1725
__attribute__((nonnull, warn_unused_result))
1726
int good_interface(const struct dirent *if_entry){
1727
if(if_entry->d_name[0] == '.'){
1732
if(not get_flags(if_entry->d_name, &ifr)){
1734
fprintf_plus(stderr, "Failed to get flags for interface "
1735
"\"%s\"\n", if_entry->d_name);
1740
if(not good_flags(if_entry->d_name, &ifr)){
1747
* This function determines if a network interface is up.
1749
__attribute__((nonnull, warn_unused_result))
1750
bool interface_is_up(const char *interface){
1752
if(not get_flags(interface, &ifr)){
1754
fprintf_plus(stderr, "Failed to get flags for interface "
1755
"\"%s\"\n", interface);
1760
return (bool)(ifr.ifr_flags & IFF_UP);
1764
* This function determines if a network interface is running
1766
__attribute__((nonnull, warn_unused_result))
1767
bool interface_is_running(const char *interface){
1769
if(not get_flags(interface, &ifr)){
1771
fprintf_plus(stderr, "Failed to get flags for interface "
1772
"\"%s\"\n", interface);
1777
return (bool)(ifr.ifr_flags & IFF_RUNNING);
1780
__attribute__((nonnull, pure, warn_unused_result))
1781
int notdotentries(const struct dirent *direntry){
1782
/* Skip "." and ".." */
1783
if(direntry->d_name[0] == '.'
1784
and (direntry->d_name[1] == '\0'
1785
or (direntry->d_name[1] == '.'
1786
and direntry->d_name[2] == '\0'))){
1792
/* Is this directory entry a runnable program? */
1793
__attribute__((nonnull, warn_unused_result))
1794
int runnable_hook(const struct dirent *direntry){
1799
if((direntry->d_name)[0] == '\0'){
1804
sret = strspn(direntry->d_name, "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
1805
"abcdefghijklmnopqrstuvwxyz"
1808
if((direntry->d_name)[sret] != '\0'){
1809
/* Contains non-allowed characters */
1811
fprintf_plus(stderr, "Ignoring hook \"%s\" with bad name\n",
1817
ret = fstatat(hookdir_fd, direntry->d_name, &st, 0);
1820
perror_plus("Could not stat hook");
1824
if(not (S_ISREG(st.st_mode))){
1825
/* Not a regular file */
1827
fprintf_plus(stderr, "Ignoring hook \"%s\" - not a file\n",
1832
if(not (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))){
1833
/* Not executable */
1835
fprintf_plus(stderr, "Ignoring hook \"%s\" - not executable\n",
1841
fprintf_plus(stderr, "Hook \"%s\" is acceptable\n",
1847
__attribute__((nonnull, warn_unused_result))
1848
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,
1849
mandos_context *mc){
1851
struct timespec now;
1852
struct timespec waited_time;
1853
intmax_t block_time;
1856
if(mc->current_server == NULL){
1858
fprintf_plus(stderr, "Wait until first server is found."
1861
ret = avahi_simple_poll_iterate(s, -1);
1864
fprintf_plus(stderr, "Check current_server if we should run"
1867
/* the current time */
1868
ret = clock_gettime(CLOCK_MONOTONIC, &now);
1870
perror_plus("clock_gettime");
1873
/* Calculating in ms how long time between now and server
1874
who we visted longest time ago. Now - last seen. */
1875
waited_time.tv_sec = (now.tv_sec
1876
- mc->current_server->last_seen.tv_sec);
1877
waited_time.tv_nsec = (now.tv_nsec
1878
- mc->current_server->last_seen.tv_nsec);
1879
/* total time is 10s/10,000ms.
1880
Converting to s from ms by dividing by 1,000,
1881
and ns to ms by dividing by 1,000,000. */
1882
block_time = ((retry_interval
1883
- ((intmax_t)waited_time.tv_sec * 1000))
1884
- ((intmax_t)waited_time.tv_nsec / 1000000));
1887
fprintf_plus(stderr, "Blocking for %" PRIdMAX " ms\n",
1891
if(block_time <= 0){
1892
ret = start_mandos_communication(mc->current_server->ip,
1893
mc->current_server->port,
1894
mc->current_server->if_index,
1895
mc->current_server->af, mc);
1897
avahi_simple_poll_quit(s);
1900
ret = clock_gettime(CLOCK_MONOTONIC,
1901
&mc->current_server->last_seen);
1903
perror_plus("clock_gettime");
1906
mc->current_server = mc->current_server->next;
1907
block_time = 0; /* Call avahi to find new Mandos
1908
servers, but don't block */
1911
ret = avahi_simple_poll_iterate(s, (int)block_time);
1914
if(ret > 0 or errno != EINTR){
1915
return (ret != 1) ? ret : 0;
1921
__attribute__((nonnull))
1922
void run_network_hooks(const char *mode, const char *interface,
1924
struct dirent **direntries = NULL;
1925
if(hookdir_fd == -1){
1926
hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH
1928
if(hookdir_fd == -1){
1929
if(errno == ENOENT){
1931
fprintf_plus(stderr, "Network hook directory \"%s\" not"
1932
" found\n", hookdir);
1935
perror_plus("open");
1940
int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));
1942
perror_plus("open(\"/dev/null\", O_RDONLY)");
1945
int numhooks = scandirat(hookdir_fd, ".", &direntries,
1946
runnable_hook, alphasort);
1948
perror_plus("scandir");
1952
struct dirent *direntry;
1954
for(int i = 0; i < numhooks; i++){
1955
direntry = direntries[i];
1957
fprintf_plus(stderr, "Running network hook \"%s\"\n",
1960
pid_t hook_pid = fork();
1963
/* Raise privileges */
1964
errno = raise_privileges_permanently();
1966
perror_plus("Failed to raise privileges");
1973
perror_plus("setgid");
1976
/* Reset supplementary groups */
1978
ret = setgroups(0, NULL);
1980
perror_plus("setgroups");
1983
ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);
1985
perror_plus("setenv");
1988
ret = setenv("DEVICE", interface, 1);
1990
perror_plus("setenv");
1993
ret = setenv("VERBOSITY", debug ? "1" : "0", 1);
1995
perror_plus("setenv");
1998
ret = setenv("MODE", mode, 1);
2000
perror_plus("setenv");
2004
ret = asprintf(&delaystring, "%f", (double)delay);
2006
perror_plus("asprintf");
2009
ret = setenv("DELAY", delaystring, 1);
2012
perror_plus("setenv");
2016
if(connect_to != NULL){
2017
ret = setenv("CONNECT", connect_to, 1);
2019
perror_plus("setenv");
2023
int hook_fd = (int)TEMP_FAILURE_RETRY(openat(hookdir_fd,
2027
perror_plus("openat");
2028
_exit(EXIT_FAILURE);
2030
if(close(hookdir_fd) == -1){
2031
perror_plus("close");
2032
_exit(EXIT_FAILURE);
2034
ret = dup2(devnull, STDIN_FILENO);
2036
perror_plus("dup2(devnull, STDIN_FILENO)");
2039
ret = close(devnull);
2041
perror_plus("close");
2044
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
2046
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
2049
if(fexecve(hook_fd, (char *const []){ direntry->d_name, NULL },
2051
perror_plus("fexecve");
2052
_exit(EXIT_FAILURE);
2056
perror_plus("fork");
2061
if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){
2062
perror_plus("waitpid");
2066
if(WIFEXITED(status)){
2067
if(WEXITSTATUS(status) != 0){
2068
fprintf_plus(stderr, "Warning: network hook \"%s\" exited"
2069
" with status %d\n", direntry->d_name,
2070
WEXITSTATUS(status));
2074
} else if(WIFSIGNALED(status)){
2075
fprintf_plus(stderr, "Warning: network hook \"%s\" died by"
2076
" signal %d\n", direntry->d_name,
2081
fprintf_plus(stderr, "Warning: network hook \"%s\""
2082
" crashed\n", direntry->d_name);
2088
fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",
2094
if(close(hookdir_fd) == -1){
2095
perror_plus("close");
2102
__attribute__((nonnull, warn_unused_result))
2103
int bring_up_interface(const char *const interface,
2105
int old_errno = errno;
2107
struct ifreq network;
2108
unsigned int if_index = if_nametoindex(interface);
2110
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
2120
if(not interface_is_up(interface)){
2122
int ioctl_errno = 0;
2123
if(not get_flags(interface, &network)){
2125
fprintf_plus(stderr, "Failed to get flags for interface "
2126
"\"%s\"\n", interface);
2130
network.ifr_flags |= IFF_UP; /* set flag */
2132
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
2135
perror_plus("socket");
2143
perror_plus("close");
2150
fprintf_plus(stderr, "Bringing up interface \"%s\"\n",
2154
/* Raise privileges */
2155
ret_errno = raise_privileges();
2158
perror_plus("Failed to raise privileges");
2163
bool restore_loglevel = false;
2165
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
2166
messages about the network interface to mess up the prompt */
2167
ret_linux = klogctl(8, NULL, 5);
2168
if(ret_linux == -1){
2169
perror_plus("klogctl");
2171
restore_loglevel = true;
2174
#endif /* __linux__ */
2175
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
2176
ioctl_errno = errno;
2178
if(restore_loglevel){
2179
ret_linux = klogctl(7, NULL, 0);
2180
if(ret_linux == -1){
2181
perror_plus("klogctl");
2184
#endif /* __linux__ */
2186
/* If raise_privileges() succeeded above */
2188
/* Lower privileges */
2189
ret_errno = lower_privileges();
2192
perror_plus("Failed to lower privileges");
2196
/* Close the socket */
2199
perror_plus("close");
2202
if(ret_setflags == -1){
2203
errno = ioctl_errno;
2204
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
2209
fprintf_plus(stderr, "Interface \"%s\" is already up; good\n",
2213
/* Sleep checking until interface is running.
2214
Check every 0.25s, up to total time of delay */
2215
for(int i = 0; i < delay * 4; i++){
2216
if(interface_is_running(interface)){
2219
struct timespec sleeptime = { .tv_nsec = 250000000 };
2220
ret = nanosleep(&sleeptime, NULL);
2221
if(ret == -1 and errno != EINTR){
2222
perror_plus("nanosleep");
2230
__attribute__((nonnull, warn_unused_result))
2231
int take_down_interface(const char *const interface){
2232
int old_errno = errno;
2233
struct ifreq network;
2234
unsigned int if_index = if_nametoindex(interface);
2236
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
2240
if(interface_is_up(interface)){
2242
int ioctl_errno = 0;
2243
if(not get_flags(interface, &network) and debug){
2245
fprintf_plus(stderr, "Failed to get flags for interface "
2246
"\"%s\"\n", interface);
2250
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
2252
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
2255
perror_plus("socket");
2261
fprintf_plus(stderr, "Taking down interface \"%s\"\n",
2265
/* Raise privileges */
2266
ret_errno = raise_privileges();
2269
perror_plus("Failed to raise privileges");
2272
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
2273
ioctl_errno = errno;
2275
/* If raise_privileges() succeeded above */
2277
/* Lower privileges */
2278
ret_errno = lower_privileges();
2281
perror_plus("Failed to lower privileges");
2285
/* Close the socket */
2286
int ret = close(sd);
2288
perror_plus("close");
2291
if(ret_setflags == -1){
2292
errno = ioctl_errno;
2293
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
2298
fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",
897
2306
int main(int argc, char *argv[]){
2307
mandos_context mc = { .server = NULL, .dh_bits = 0,
2308
.priority = "SECURE256:!CTYPE-X.509"
2309
":+CTYPE-OPENPGP:!RSA:+SIGN-DSA-SHA256",
2310
.current_server = NULL, .interfaces = NULL,
2311
.interfaces_size = 0 };
898
2312
AvahiSServiceBrowser *sb = NULL;
901
2315
intmax_t tmpmax;
903
2317
int exitcode = EXIT_SUCCESS;
904
const char *interface = "eth0";
905
struct ifreq network;
907
bool take_down_interface = false;
910
char *connect_to = NULL;
911
char tempdir[] = "/tmp/mandosXXXXXX";
912
bool tempdir_created = false;
2318
char *interfaces_to_take_down = NULL;
2319
size_t interfaces_to_take_down_size = 0;
2320
char run_tempdir[] = "/run/tmp/mandosXXXXXX";
2321
char old_tempdir[] = "/tmp/mandosXXXXXX";
2322
char *tempdir = NULL;
913
2323
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
914
2324
const char *seckey = PATHDIR "/" SECKEY;
915
2325
const char *pubkey = PATHDIR "/" PUBKEY;
2326
const char *dh_params_file = NULL;
2327
char *interfaces_hooks = NULL;
917
2329
bool gnutls_initialized = false;
918
2330
bool gpgme_initialized = false;
919
2331
float delay = 2.5f;
2332
double retry_interval = 10; /* 10s between trying a server and
2333
retrying the same server again */
921
struct sigaction old_sigterm_action;
2335
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
922
2336
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
2341
/* Lower any group privileges we might have, just to be safe */
2345
perror_plus("setgid");
2348
/* Lower user privileges (temporarily) */
2352
perror_plus("seteuid");
925
2360
struct argp_option options[] = {
926
2361
{ .name = "debug", .key = 128,
994
2458
delay = strtof(arg, &tmp);
995
2459
if(errno != 0 or tmp == arg or *tmp != '\0'){
996
fprintf(stderr, "Bad delay\n");
2460
argp_error(state, "Bad delay");
2462
case 132: /* --retry */
2464
retry_interval = strtod(arg, &tmp);
2465
if(errno != 0 or tmp == arg or *tmp != '\0'
2466
or (retry_interval * 1000) > INT_MAX
2467
or retry_interval < 0){
2468
argp_error(state, "Bad retry interval");
2471
case 133: /* --network-hook-dir */
2475
* These reproduce what we would get without ARGP_NO_HELP
2477
case '?': /* --help */
2478
argp_state_help(state, state->out_stream,
2479
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
2480
& ~(unsigned int)ARGP_HELP_EXIT_OK);
2481
case -3: /* --usage */
2482
argp_state_help(state, state->out_stream,
2483
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
2484
case 'V': /* --version */
2485
fprintf_plus(state->out_stream, "%s\n", argp_program_version);
2486
exit(argp_err_exit_status);
1005
2489
return ARGP_ERR_UNKNOWN;
1010
2494
struct argp argp = { .options = options, .parser = parse_opt,
1011
2495
.args_doc = "",
1012
2496
.doc = "Mandos client -- Get and decrypt"
1013
2497
" passwords from a Mandos server" };
1014
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
1015
if(ret == ARGP_ERR_UNKNOWN){
1016
fprintf(stderr, "Unknown error while parsing arguments\n");
1017
exitcode = EXIT_FAILURE;
2498
ret_errno = argp_parse(&argp, argc, argv,
2499
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
2506
perror_plus("argp_parse");
2507
exitcode = EX_OSERR;
2510
exitcode = EX_USAGE;
2516
/* Work around Debian bug #633582:
2517
<https://bugs.debian.org/633582> */
2519
/* Re-raise privileges */
2520
ret = raise_privileges();
2523
perror_plus("Failed to raise privileges");
2527
if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){
2528
int seckey_fd = open(seckey, O_RDONLY);
2529
if(seckey_fd == -1){
2530
perror_plus("open");
2532
ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));
2534
perror_plus("fstat");
2536
if(S_ISREG(st.st_mode)
2537
and st.st_uid == 0 and st.st_gid == 0){
2538
ret = fchown(seckey_fd, uid, gid);
2540
perror_plus("fchown");
2548
if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){
2549
int pubkey_fd = open(pubkey, O_RDONLY);
2550
if(pubkey_fd == -1){
2551
perror_plus("open");
2553
ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));
2555
perror_plus("fstat");
2557
if(S_ISREG(st.st_mode)
2558
and st.st_uid == 0 and st.st_gid == 0){
2559
ret = fchown(pubkey_fd, uid, gid);
2561
perror_plus("fchown");
2569
if(dh_params_file != NULL
2570
and strcmp(dh_params_file, PATHDIR "/dhparams.pem" ) == 0){
2571
int dhparams_fd = open(dh_params_file, O_RDONLY);
2572
if(dhparams_fd == -1){
2573
perror_plus("open");
2575
ret = (int)TEMP_FAILURE_RETRY(fstat(dhparams_fd, &st));
2577
perror_plus("fstat");
2579
if(S_ISREG(st.st_mode)
2580
and st.st_uid == 0 and st.st_gid == 0){
2581
ret = fchown(dhparams_fd, uid, gid);
2583
perror_plus("fchown");
2591
/* Lower privileges */
2592
ret = lower_privileges();
2595
perror_plus("Failed to lower privileges");
2600
/* Remove invalid interface names (except "none") */
2602
char *interface = NULL;
2603
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2605
if(strcmp(interface, "none") != 0
2606
and if_nametoindex(interface) == 0){
2607
if(interface[0] != '\0'){
2608
fprintf_plus(stderr, "Not using nonexisting interface"
2609
" \"%s\"\n", interface);
2611
argz_delete(&mc.interfaces, &mc.interfaces_size, interface);
2617
/* Run network hooks */
2619
if(mc.interfaces != NULL){
2620
interfaces_hooks = malloc(mc.interfaces_size);
2621
if(interfaces_hooks == NULL){
2622
perror_plus("malloc");
2625
memcpy(interfaces_hooks, mc.interfaces, mc.interfaces_size);
2626
argz_stringify(interfaces_hooks, mc.interfaces_size, (int)',');
2628
run_network_hooks("start", interfaces_hooks != NULL ?
2629
interfaces_hooks : "", delay);
1027
2637
from the signal handler */
1028
2638
/* Initialize the pseudo-RNG for Avahi */
1029
2639
srand((unsigned int) time(NULL));
1030
mc.simple_poll = avahi_simple_poll_new();
1031
if(mc.simple_poll == NULL){
1032
fprintf(stderr, "Avahi: Failed to create simple poll object.\n");
1033
exitcode = EXIT_FAILURE;
2640
simple_poll = avahi_simple_poll_new();
2641
if(simple_poll == NULL){
2642
fprintf_plus(stderr,
2643
"Avahi: Failed to create simple poll object.\n");
2644
exitcode = EX_UNAVAILABLE;
1037
2648
sigemptyset(&sigterm_action.sa_mask);
1038
2649
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1040
perror("sigaddset");
1041
exitcode = EXIT_FAILURE;
2651
perror_plus("sigaddset");
2652
exitcode = EX_OSERR;
1044
2655
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1046
perror("sigaddset");
1047
exitcode = EXIT_FAILURE;
2657
perror_plus("sigaddset");
2658
exitcode = EX_OSERR;
1050
2661
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1052
perror("sigaddset");
1053
exitcode = EXIT_FAILURE;
1056
ret = sigaction(SIGTERM, &sigterm_action, &old_sigterm_action);
1058
perror("sigaction");
1059
exitcode = EXIT_FAILURE;
1063
/* If the interface is down, bring it up */
1064
if(interface[0] != '\0'){
1065
if_index = (AvahiIfIndex) if_nametoindex(interface);
1067
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1068
exitcode = EXIT_FAILURE;
1077
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1078
messages to mess up the prompt */
1079
ret = klogctl(8, NULL, 5);
1080
bool restore_loglevel = true;
1082
restore_loglevel = false;
1085
#endif /* __linux__ */
1087
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1090
exitcode = EXIT_FAILURE;
1092
if(restore_loglevel){
1093
ret = klogctl(7, NULL, 0);
1098
#endif /* __linux__ */
1101
strcpy(network.ifr_name, interface);
1102
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1104
perror("ioctl SIOCGIFFLAGS");
1106
if(restore_loglevel){
1107
ret = klogctl(7, NULL, 0);
1112
#endif /* __linux__ */
1113
exitcode = EXIT_FAILURE;
1116
if((network.ifr_flags & IFF_UP) == 0){
1117
network.ifr_flags |= IFF_UP;
1118
take_down_interface = true;
1119
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1121
take_down_interface = false;
1122
perror("ioctl SIOCSIFFLAGS");
1123
exitcode = EXIT_FAILURE;
1125
if(restore_loglevel){
1126
ret = klogctl(7, NULL, 0);
2663
perror_plus("sigaddset");
2664
exitcode = EX_OSERR;
2667
/* Need to check if the handler is SIG_IGN before handling:
2668
| [[info:libc:Initial Signal Actions]] |
2669
| [[info:libc:Basic Signal Handling]] |
2671
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
2673
perror_plus("sigaction");
2676
if(old_sigterm_action.sa_handler != SIG_IGN){
2677
ret = sigaction(SIGINT, &sigterm_action, NULL);
2679
perror_plus("sigaction");
2680
exitcode = EX_OSERR;
2684
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
2686
perror_plus("sigaction");
2689
if(old_sigterm_action.sa_handler != SIG_IGN){
2690
ret = sigaction(SIGHUP, &sigterm_action, NULL);
2692
perror_plus("sigaction");
2693
exitcode = EX_OSERR;
2697
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
2699
perror_plus("sigaction");
2702
if(old_sigterm_action.sa_handler != SIG_IGN){
2703
ret = sigaction(SIGTERM, &sigterm_action, NULL);
2705
perror_plus("sigaction");
2706
exitcode = EX_OSERR;
2711
/* If no interfaces were specified, make a list */
2712
if(mc.interfaces == NULL){
2713
struct dirent **direntries = NULL;
2714
/* Look for any good interfaces */
2715
ret = scandir(sys_class_net, &direntries, good_interface,
2718
/* Add all found interfaces to interfaces list */
2719
for(int i = 0; i < ret; ++i){
2720
ret_errno = argz_add(&mc.interfaces, &mc.interfaces_size,
2721
direntries[i]->d_name);
2724
perror_plus("argz_add");
2725
free(direntries[i]);
2729
fprintf_plus(stderr, "Will use interface \"%s\"\n",
2730
direntries[i]->d_name);
2732
free(direntries[i]);
2739
fprintf_plus(stderr, "Could not find a network interface\n");
2740
exitcode = EXIT_FAILURE;
2745
/* Bring up interfaces which are down, and remove any "none"s */
2747
char *interface = NULL;
2748
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2750
/* If interface name is "none", stop bringing up interfaces.
2751
Also remove all instances of "none" from the list */
2752
if(strcmp(interface, "none") == 0){
2753
argz_delete(&mc.interfaces, &mc.interfaces_size,
2756
while((interface = argz_next(mc.interfaces,
2757
mc.interfaces_size, interface))){
2758
if(strcmp(interface, "none") == 0){
2759
argz_delete(&mc.interfaces, &mc.interfaces_size,
1131
#endif /* __linux__ */
1135
/* sleep checking until interface is running */
1136
for(int i=0; i < delay * 4; i++){
1137
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1139
perror("ioctl SIOCGIFFLAGS");
1140
} else if(network.ifr_flags & IFF_RUNNING){
1143
struct timespec sleeptime = { .tv_nsec = 250000000 };
1144
ret = nanosleep(&sleeptime, NULL);
1145
if(ret == -1 and errno != EINTR){
1146
perror("nanosleep");
1149
if(not take_down_interface){
1150
/* We won't need the socket anymore */
1151
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1157
if(restore_loglevel){
1158
/* Restores kernel loglevel to default */
1159
ret = klogctl(7, NULL, 0);
1164
#endif /* __linux__ */
1189
ret = init_gnutls_global(pubkey, seckey);
1191
fprintf(stderr, "init_gnutls_global failed\n");
1192
exitcode = EXIT_FAILURE;
2766
bool interface_was_up = interface_is_up(interface);
2767
errno = bring_up_interface(interface, delay);
2768
if(not interface_was_up){
2770
fprintf_plus(stderr, "Failed to bring up interface \"%s\":"
2771
" %s\n", interface, strerror(errno));
2773
errno = argz_add(&interfaces_to_take_down,
2774
&interfaces_to_take_down_size,
2777
perror_plus("argz_add");
2782
if(debug and (interfaces_to_take_down == NULL)){
2783
fprintf_plus(stderr, "No interfaces were brought up\n");
2787
/* If we only got one interface, explicitly use only that one */
2788
if(argz_count(mc.interfaces, mc.interfaces_size) == 1){
2790
fprintf_plus(stderr, "Using only interface \"%s\"\n",
2793
if_index = (AvahiIfIndex)if_nametoindex(mc.interfaces);
2800
ret = init_gnutls_global(pubkey, seckey, dh_params_file, &mc);
2802
fprintf_plus(stderr, "init_gnutls_global failed\n");
2803
exitcode = EX_UNAVAILABLE;
1195
2806
gnutls_initialized = true;
1357
3005
gpgme_release(mc.ctx);
1360
/* Take down the network interface */
1361
if(take_down_interface){
1362
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1364
perror("ioctl SIOCGIFFLAGS");
1365
} else if(network.ifr_flags & IFF_UP) {
1366
network.ifr_flags &= ~IFF_UP; /* clear flag */
1367
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1369
perror("ioctl SIOCSIFFLAGS");
1372
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1378
/* Removes the temp directory used by GPGME */
1379
if(tempdir_created){
1381
struct dirent *direntry;
1382
d = opendir(tempdir);
1384
if(errno != ENOENT){
1389
direntry = readdir(d);
1390
if(direntry == NULL){
1393
/* Skip "." and ".." */
1394
if(direntry->d_name[0] == '.'
1395
and (direntry->d_name[1] == '\0'
1396
or (direntry->d_name[1] == '.'
1397
and direntry->d_name[2] == '\0'))){
1400
char *fullname = NULL;
1401
ret = asprintf(&fullname, "%s/%s", tempdir,
1407
ret = remove(fullname);
1409
fprintf(stderr, "remove(\"%s\"): %s\n", fullname,
1416
ret = rmdir(tempdir);
1417
if(ret == -1 and errno != ENOENT){
3008
/* Cleans up the circular linked list of Mandos servers the client
3010
if(mc.current_server != NULL){
3011
mc.current_server->prev->next = NULL;
3012
while(mc.current_server != NULL){
3013
server *next = mc.current_server->next;
3015
#pragma GCC diagnostic push
3016
#pragma GCC diagnostic ignored "-Wcast-qual"
3018
free((char *)(mc.current_server->ip));
3020
#pragma GCC diagnostic pop
3022
free(mc.current_server);
3023
mc.current_server = next;
3027
/* Re-raise privileges */
3029
ret = raise_privileges();
3032
perror_plus("Failed to raise privileges");
3035
/* Run network hooks */
3036
run_network_hooks("stop", interfaces_hooks != NULL ?
3037
interfaces_hooks : "", delay);
3039
/* Take down the network interfaces which were brought up */
3041
char *interface = NULL;
3042
while((interface = argz_next(interfaces_to_take_down,
3043
interfaces_to_take_down_size,
3045
ret = take_down_interface(interface);
3048
perror_plus("Failed to take down interface");
3051
if(debug and (interfaces_to_take_down == NULL)){
3052
fprintf_plus(stderr, "No interfaces needed to be taken"
3058
ret = lower_privileges_permanently();
3061
perror_plus("Failed to lower privileges permanently");
3065
free(interfaces_to_take_down);
3066
free(interfaces_hooks);
3068
void clean_dir_at(int base, const char * const dirname,
3070
struct dirent **direntries = NULL;
3072
int dir_fd = (int)TEMP_FAILURE_RETRY(openat(base, dirname,
3078
perror_plus("open");
3081
int numentries = scandirat(dir_fd, ".", &direntries,
3082
notdotentries, alphasort);
3083
if(numentries >= 0){
3084
for(int i = 0; i < numentries; i++){
3086
fprintf_plus(stderr, "Unlinking \"%s/%s\"\n",
3087
dirname, direntries[i]->d_name);
3089
dret = unlinkat(dir_fd, direntries[i]->d_name, 0);
3091
if(errno == EISDIR){
3092
dret = unlinkat(dir_fd, direntries[i]->d_name,
3095
if((dret == -1) and (errno == ENOTEMPTY)
3096
and (strcmp(direntries[i]->d_name, "private-keys-v1.d")
3097
== 0) and (level == 0)){
3098
/* Recurse only in this special case */
3099
clean_dir_at(dir_fd, direntries[i]->d_name, level+1);
3102
if((dret == -1) and (errno != ENOENT)){
3103
fprintf_plus(stderr, "unlink(\"%s/%s\"): %s\n", dirname,
3104
direntries[i]->d_name, strerror(errno));
3107
free(direntries[i]);
3110
/* need to clean even if 0 because man page doesn't specify */
3112
dret = unlinkat(base, dirname, AT_REMOVEDIR);
3113
if(dret == -1 and errno != ENOENT){
3114
perror_plus("rmdir");
3117
perror_plus("scandirat");
3122
/* Removes the GPGME temp directory and all files inside */
3123
if(tempdir != NULL){
3124
clean_dir_at(-1, tempdir, 0);
3128
sigemptyset(&old_sigterm_action.sa_mask);
3129
old_sigterm_action.sa_handler = SIG_DFL;
3130
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
3131
&old_sigterm_action,
3134
perror_plus("sigaction");
3137
ret = raise(signal_received);
3138
} while(ret != 0 and errno == EINTR);
3140
perror_plus("raise");
3143
TEMP_FAILURE_RETRY(pause());
1422
3146
return exitcode;