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- Committer: Teddy Hogeborn
- Date: 2012-06-14 17:03:12 UTC
- Revision ID: teddy@recompile.se-20120614170312-pl62gn832v09z4bi
* plugins.d/mandos-client.c: Don't use assert(). Use in_port_t for
port numbers everywhere except the
"resolve_callback" function; its
signature is forced by the signature of
the avahi_s_service_resolver_new
function.
port numbers everywhere except the
"resolve_callback" function; its
signature is forced by the signature of
the avahi_s_service_resolver_new
function.
added
removed
plugins.d/mandos-client.c
9
9
* "browse_callback", and parts of "main".
10
10
*
11
11
* Everything else is
12
* Copyright © 2008-2016 Teddy Hogeborn
13
* Copyright © 2008-2016 Björn Påhlsson
12
* Copyright © 2008-2012 Teddy Hogeborn
13
* Copyright © 2008-2012 Björn Påhlsson
14
14
*
15
15
* This program is free software: you can redistribute it and/or
16
16
* modify it under the terms of the GNU General Public License as
32
32
/* Needed by GPGME, specifically gpgme_data_seek() */
33
33
#ifndef _LARGEFILE_SOURCE
34
34
#define _LARGEFILE_SOURCE
35
#endif /* not _LARGEFILE_SOURCE */
35
#endif
36
36
#ifndef _FILE_OFFSET_BITS
37
37
#define _FILE_OFFSET_BITS 64
38
#endif /* not _FILE_OFFSET_BITS */
38
#endif
39
39
40
40
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
41
41
42
42
#include <stdio.h> /* fprintf(), stderr, fwrite(),
43
stdout, ferror() */
43
stdout, ferror(), remove() */
44
44
#include <stdint.h> /* uint16_t, uint32_t, intptr_t */
45
45
#include <stddef.h> /* NULL, size_t, ssize_t */
46
46
#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),
47
47
strtof(), abort() */
48
48
#include <stdbool.h> /* bool, false, true */
49
#include <string.h> /* strcmp(), strlen(), strerror(),
50
asprintf(), strncpy(), strsignal()
51
*/
49
#include <string.h> /* memset(), strcmp(), strlen(),
50
strerror(), asprintf(), strcpy() */
52
51
#include <sys/ioctl.h> /* ioctl */
53
52
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
54
53
sockaddr_in6, PF_INET6,
56
55
opendir(), DIR */
57
56
#include <sys/stat.h> /* open(), S_ISREG */
58
57
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
59
inet_pton(), connect(),
60
getnameinfo() */
61
#include <fcntl.h> /* open(), unlinkat(), AT_REMOVEDIR */
58
inet_pton(), connect() */
59
#include <fcntl.h> /* open() */
62
60
#include <dirent.h> /* opendir(), struct dirent, readdir()
63
61
*/
64
62
#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,
65
63
strtoimax() */
66
#include <errno.h> /* perror(), errno, EINTR, EINVAL,
67
EAI_SYSTEM, ENETUNREACH,
68
EHOSTUNREACH, ECONNREFUSED, EPROTO,
69
EIO, ENOENT, ENXIO, ENOMEM, EISDIR,
70
ENOTEMPTY,
64
#include <errno.h> /* perror(), errno,
71
65
program_invocation_short_name */
72
66
#include <time.h> /* nanosleep(), time(), sleep() */
73
67
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
78
72
*/
79
73
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
80
74
getuid(), getgid(), seteuid(),
81
setgid(), pause(), _exit(),
82
unlinkat() */
83
#include <arpa/inet.h> /* inet_pton(), htons() */
75
setgid(), pause(), _exit() */
76
#include <arpa/inet.h> /* inet_pton(), htons, inet_ntop() */
84
77
#include <iso646.h> /* not, or, and */
85
78
#include <argp.h> /* struct argp_option, error_t, struct
86
79
argp_state, struct argp,
98
91
argz_delete(), argz_append(),
99
92
argz_stringify(), argz_add(),
100
93
argz_count() */
101
#include <netdb.h> /* getnameinfo(), NI_NUMERICHOST,
102
EAI_SYSTEM, gai_strerror() */
103
94
104
95
#ifdef __linux__
105
96
#include <sys/klog.h> /* klogctl() */
147
138
static const char sys_class_net[] = "/sys/class/net";
148
139
char *connect_to = NULL;
149
140
const char *hookdir = HOOKDIR;
150
int hookdir_fd = -1;
151
141
uid_t uid = 65534;
152
142
gid_t gid = 65534;
153
143
164
154
165
155
/* Used for passing in values through the Avahi callback functions */
166
156
typedef struct {
157
AvahiSimplePoll *simple_poll;
167
158
AvahiServer *server;
168
159
gnutls_certificate_credentials_t cred;
169
160
unsigned int dh_bits;
171
162
const char *priority;
172
163
gpgme_ctx_t ctx;
173
164
server *current_server;
174
char *interfaces;
175
size_t interfaces_size;
176
165
} mandos_context;
177
166
178
/* global so signal handler can reach it*/
179
AvahiSimplePoll *simple_poll;
167
/* global context so signal handler can reach it*/
168
mandos_context mc = { .simple_poll = NULL, .server = NULL,
169
.dh_bits = 1024, .priority = "SECURE256"
170
":!CTYPE-X.509:+CTYPE-OPENPGP",
171
.current_server = NULL };
180
172
181
173
sig_atomic_t quit_now = 0;
182
174
int signal_received = 0;
190
182
perror(print_text);
191
183
}
192
184
193
__attribute__((format (gnu_printf, 2, 3), nonnull))
185
__attribute__((format (gnu_printf, 2, 3)))
194
186
int fprintf_plus(FILE *stream, const char *format, ...){
195
187
va_list ap;
196
188
va_start (ap, format);
197
189
198
190
TEMP_FAILURE_RETRY(fprintf(stream, "Mandos plugin %s: ",
199
191
program_invocation_short_name));
200
return (int)TEMP_FAILURE_RETRY(vfprintf(stream, format, ap));
192
return TEMP_FAILURE_RETRY(vfprintf(stream, format, ap));
201
193
}
202
194
203
195
/*
205
197
* bytes. "buffer_capacity" is how much is currently allocated,
206
198
* "buffer_length" is how much is already used.
207
199
*/
208
__attribute__((nonnull, warn_unused_result))
209
200
size_t incbuffer(char **buffer, size_t buffer_length,
210
201
size_t buffer_capacity){
211
202
if(buffer_length + BUFFER_SIZE > buffer_capacity){
212
char *new_buf = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
213
if(new_buf == NULL){
214
int old_errno = errno;
215
free(*buffer);
216
errno = old_errno;
217
*buffer = NULL;
203
*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
204
if(buffer == NULL){
218
205
return 0;
219
206
}
220
*buffer = new_buf;
221
207
buffer_capacity += BUFFER_SIZE;
222
208
}
223
209
return buffer_capacity;
224
210
}
225
211
226
212
/* Add server to set of servers to retry periodically */
227
__attribute__((nonnull, warn_unused_result))
228
213
bool add_server(const char *ip, in_port_t port, AvahiIfIndex if_index,
229
int af, server **current_server){
214
int af){
230
215
int ret;
231
216
server *new_server = malloc(sizeof(server));
232
217
if(new_server == NULL){
239
224
.af = af };
240
225
if(new_server->ip == NULL){
241
226
perror_plus("strdup");
242
free(new_server);
243
return false;
244
}
245
ret = clock_gettime(CLOCK_MONOTONIC, &(new_server->last_seen));
246
if(ret == -1){
247
perror_plus("clock_gettime");
248
#ifdef __GNUC__
249
#pragma GCC diagnostic push
250
#pragma GCC diagnostic ignored "-Wcast-qual"
251
#endif
252
free((char *)(new_server->ip));
253
#ifdef __GNUC__
254
#pragma GCC diagnostic pop
255
#endif
256
free(new_server);
257
227
return false;
258
228
}
259
229
/* Special case of first server */
260
if(*current_server == NULL){
230
if (mc.current_server == NULL){
261
231
new_server->next = new_server;
262
232
new_server->prev = new_server;
263
*current_server = new_server;
233
mc.current_server = new_server;
234
/* Place the new server last in the list */
264
235
} else {
265
/* Place the new server last in the list */
266
new_server->next = *current_server;
267
new_server->prev = (*current_server)->prev;
236
new_server->next = mc.current_server;
237
new_server->prev = mc.current_server->prev;
268
238
new_server->prev->next = new_server;
269
(*current_server)->prev = new_server;
239
mc.current_server->prev = new_server;
240
}
241
ret = clock_gettime(CLOCK_MONOTONIC, &mc.current_server->last_seen);
242
if(ret == -1){
243
perror_plus("clock_gettime");
244
return false;
270
245
}
271
246
return true;
272
247
}
274
249
/*
275
250
* Initialize GPGME.
276
251
*/
277
__attribute__((nonnull, warn_unused_result))
278
static bool init_gpgme(const char * const seckey,
279
const char * const pubkey,
280
const char * const tempdir,
281
mandos_context *mc){
252
static bool init_gpgme(const char *seckey, const char *pubkey,
253
const char *tempdir){
282
254
gpgme_error_t rc;
283
255
gpgme_engine_info_t engine_info;
284
256
257
285
258
/*
286
259
* Helper function to insert pub and seckey to the engine keyring.
287
260
*/
288
bool import_key(const char * const filename){
261
bool import_key(const char *filename){
289
262
int ret;
290
263
int fd;
291
264
gpgme_data_t pgp_data;
303
276
return false;
304
277
}
305
278
306
rc = gpgme_op_import(mc->ctx, pgp_data);
279
rc = gpgme_op_import(mc.ctx, pgp_data);
307
280
if(rc != GPG_ERR_NO_ERROR){
308
281
fprintf_plus(stderr, "bad gpgme_op_import: %s: %s\n",
309
282
gpgme_strsource(rc), gpgme_strerror(rc));
310
283
return false;
311
284
}
312
285
313
ret = close(fd);
286
ret = (int)TEMP_FAILURE_RETRY(close(fd));
314
287
if(ret == -1){
315
288
perror_plus("close");
316
289
}
353
326
}
354
327
355
328
/* Create new GPGME "context" */
356
rc = gpgme_new(&(mc->ctx));
329
rc = gpgme_new(&(mc.ctx));
357
330
if(rc != GPG_ERR_NO_ERROR){
358
331
fprintf_plus(stderr, "Mandos plugin mandos-client: "
359
332
"bad gpgme_new: %s: %s\n", gpgme_strsource(rc),
372
345
* Decrypt OpenPGP data.
373
346
* Returns -1 on error
374
347
*/
375
__attribute__((nonnull, warn_unused_result))
376
348
static ssize_t pgp_packet_decrypt(const char *cryptotext,
377
349
size_t crypto_size,
378
char **plaintext,
379
mandos_context *mc){
350
char **plaintext){
380
351
gpgme_data_t dh_crypto, dh_plain;
381
352
gpgme_error_t rc;
382
353
ssize_t ret;
408
379
409
380
/* Decrypt data from the cryptotext data buffer to the plaintext
410
381
data buffer */
411
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
382
rc = gpgme_op_decrypt(mc.ctx, dh_crypto, dh_plain);
412
383
if(rc != GPG_ERR_NO_ERROR){
413
384
fprintf_plus(stderr, "bad gpgme_op_decrypt: %s: %s\n",
414
385
gpgme_strsource(rc), gpgme_strerror(rc));
415
386
plaintext_length = -1;
416
387
if(debug){
417
388
gpgme_decrypt_result_t result;
418
result = gpgme_op_decrypt_result(mc->ctx);
389
result = gpgme_op_decrypt_result(mc.ctx);
419
390
if(result == NULL){
420
391
fprintf_plus(stderr, "gpgme_op_decrypt_result failed\n");
421
392
} else {
498
469
return plaintext_length;
499
470
}
500
471
501
__attribute__((warn_unused_result, const))
502
static const char *safe_string(const char *str){
503
if(str == NULL)
504
return "(unknown)";
505
return str;
506
}
507
508
__attribute__((warn_unused_result))
509
static const char *safer_gnutls_strerror(int value){
472
static const char * safer_gnutls_strerror(int value){
510
473
const char *ret = gnutls_strerror(value);
511
return safe_string(ret);
474
if(ret == NULL)
475
ret = "(unknown)";
476
return ret;
512
477
}
513
478
514
479
/* GnuTLS log function callback */
515
__attribute__((nonnull))
516
480
static void debuggnutls(__attribute__((unused)) int level,
517
481
const char* string){
518
482
fprintf_plus(stderr, "GnuTLS: %s", string);
519
483
}
520
484
521
__attribute__((nonnull(1, 2, 4), warn_unused_result))
522
485
static int init_gnutls_global(const char *pubkeyfilename,
523
const char *seckeyfilename,
524
const char *dhparamsfilename,
525
mandos_context *mc){
486
const char *seckeyfilename){
526
487
int ret;
527
unsigned int uret;
528
488
529
489
if(debug){
530
490
fprintf_plus(stderr, "Initializing GnuTLS\n");
531
491
}
532
492
493
ret = gnutls_global_init();
494
if(ret != GNUTLS_E_SUCCESS){
495
fprintf_plus(stderr, "GnuTLS global_init: %s\n",
496
safer_gnutls_strerror(ret));
497
return -1;
498
}
499
533
500
if(debug){
534
501
/* "Use a log level over 10 to enable all debugging options."
535
502
* - GnuTLS manual
539
506
}
540
507
541
508
/* OpenPGP credentials */
542
ret = gnutls_certificate_allocate_credentials(&mc->cred);
509
ret = gnutls_certificate_allocate_credentials(&mc.cred);
543
510
if(ret != GNUTLS_E_SUCCESS){
544
511
fprintf_plus(stderr, "GnuTLS memory error: %s\n",
545
512
safer_gnutls_strerror(ret));
513
gnutls_global_deinit();
546
514
return -1;
547
515
}
548
516
554
522
}
555
523
556
524
ret = gnutls_certificate_set_openpgp_key_file
557
(mc->cred, pubkeyfilename, seckeyfilename,
525
(mc.cred, pubkeyfilename, seckeyfilename,
558
526
GNUTLS_OPENPGP_FMT_BASE64);
559
527
if(ret != GNUTLS_E_SUCCESS){
560
528
fprintf_plus(stderr,
566
534
}
567
535
568
536
/* GnuTLS server initialization */
569
ret = gnutls_dh_params_init(&mc->dh_params);
537
ret = gnutls_dh_params_init(&mc.dh_params);
570
538
if(ret != GNUTLS_E_SUCCESS){
571
539
fprintf_plus(stderr, "Error in GnuTLS DH parameter"
572
540
" initialization: %s\n",
573
541
safer_gnutls_strerror(ret));
574
542
goto globalfail;
575
543
}
576
/* If a Diffie-Hellman parameters file was given, try to use it */
577
if(dhparamsfilename != NULL){
578
gnutls_datum_t params = { .data = NULL, .size = 0 };
579
do {
580
int dhpfile = open(dhparamsfilename, O_RDONLY);
581
if(dhpfile == -1){
582
perror_plus("open");
583
dhparamsfilename = NULL;
584
break;
585
}
586
size_t params_capacity = 0;
587
while(true){
588
params_capacity = incbuffer((char **)¶ms.data,
589
(size_t)params.size,
590
(size_t)params_capacity);
591
if(params_capacity == 0){
592
perror_plus("incbuffer");
593
free(params.data);
594
params.data = NULL;
595
dhparamsfilename = NULL;
596
break;
597
}
598
ssize_t bytes_read = read(dhpfile,
599
params.data + params.size,
600
BUFFER_SIZE);
601
/* EOF */
602
if(bytes_read == 0){
603
break;
604
}
605
/* check bytes_read for failure */
606
if(bytes_read < 0){
607
perror_plus("read");
608
free(params.data);
609
params.data = NULL;
610
dhparamsfilename = NULL;
611
break;
612
}
613
params.size += (unsigned int)bytes_read;
614
}
615
if(params.data == NULL){
616
dhparamsfilename = NULL;
617
}
618
if(dhparamsfilename == NULL){
619
break;
620
}
621
ret = gnutls_dh_params_import_pkcs3(mc->dh_params, ¶ms,
622
GNUTLS_X509_FMT_PEM);
623
if(ret != GNUTLS_E_SUCCESS){
624
fprintf_plus(stderr, "Failed to parse DH parameters in file"
625
" \"%s\": %s\n", dhparamsfilename,
626
safer_gnutls_strerror(ret));
627
dhparamsfilename = NULL;
628
}
629
free(params.data);
630
} while(false);
631
}
632
if(dhparamsfilename == NULL){
633
if(mc->dh_bits == 0){
634
/* Find out the optimal number of DH bits */
635
/* Try to read the private key file */
636
gnutls_datum_t buffer = { .data = NULL, .size = 0 };
637
do {
638
int secfile = open(seckeyfilename, O_RDONLY);
639
if(secfile == -1){
640
perror_plus("open");
641
break;
642
}
643
size_t buffer_capacity = 0;
644
while(true){
645
buffer_capacity = incbuffer((char **)&buffer.data,
646
(size_t)buffer.size,
647
(size_t)buffer_capacity);
648
if(buffer_capacity == 0){
649
perror_plus("incbuffer");
650
free(buffer.data);
651
buffer.data = NULL;
652
break;
653
}
654
ssize_t bytes_read = read(secfile,
655
buffer.data + buffer.size,
656
BUFFER_SIZE);
657
/* EOF */
658
if(bytes_read == 0){
659
break;
660
}
661
/* check bytes_read for failure */
662
if(bytes_read < 0){
663
perror_plus("read");
664
free(buffer.data);
665
buffer.data = NULL;
666
break;
667
}
668
buffer.size += (unsigned int)bytes_read;
669
}
670
close(secfile);
671
} while(false);
672
/* If successful, use buffer to parse private key */
673
gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;
674
if(buffer.data != NULL){
675
{
676
gnutls_openpgp_privkey_t privkey = NULL;
677
ret = gnutls_openpgp_privkey_init(&privkey);
678
if(ret != GNUTLS_E_SUCCESS){
679
fprintf_plus(stderr, "Error initializing OpenPGP key"
680
" structure: %s",
681
safer_gnutls_strerror(ret));
682
free(buffer.data);
683
buffer.data = NULL;
684
} else {
685
ret = gnutls_openpgp_privkey_import
686
(privkey, &buffer, GNUTLS_OPENPGP_FMT_BASE64, "", 0);
687
if(ret != GNUTLS_E_SUCCESS){
688
fprintf_plus(stderr, "Error importing OpenPGP key : %s",
689
safer_gnutls_strerror(ret));
690
privkey = NULL;
691
}
692
free(buffer.data);
693
buffer.data = NULL;
694
if(privkey != NULL){
695
/* Use private key to suggest an appropriate
696
sec_param */
697
sec_param = gnutls_openpgp_privkey_sec_param(privkey);
698
gnutls_openpgp_privkey_deinit(privkey);
699
if(debug){
700
fprintf_plus(stderr, "This OpenPGP key implies using"
701
" a GnuTLS security parameter \"%s\".\n",
702
safe_string(gnutls_sec_param_get_name
703
(sec_param)));
704
}
705
}
706
}
707
}
708
if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){
709
/* Err on the side of caution */
710
sec_param = GNUTLS_SEC_PARAM_ULTRA;
711
if(debug){
712
fprintf_plus(stderr, "Falling back to security parameter"
713
" \"%s\"\n",
714
safe_string(gnutls_sec_param_get_name
715
(sec_param)));
716
}
717
}
718
}
719
uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);
720
if(uret != 0){
721
mc->dh_bits = uret;
722
if(debug){
723
fprintf_plus(stderr, "A \"%s\" GnuTLS security parameter"
724
" implies %u DH bits; using that.\n",
725
safe_string(gnutls_sec_param_get_name
726
(sec_param)),
727
mc->dh_bits);
728
}
729
} else {
730
fprintf_plus(stderr, "Failed to get implied number of DH"
731
" bits for security parameter \"%s\"): %s\n",
732
safe_string(gnutls_sec_param_get_name
733
(sec_param)),
734
safer_gnutls_strerror(ret));
735
goto globalfail;
736
}
737
} else if(debug){
738
fprintf_plus(stderr, "DH bits explicitly set to %u\n",
739
mc->dh_bits);
740
}
741
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
742
if(ret != GNUTLS_E_SUCCESS){
743
fprintf_plus(stderr, "Error in GnuTLS prime generation (%u"
744
" bits): %s\n", mc->dh_bits,
745
safer_gnutls_strerror(ret));
746
goto globalfail;
747
}
748
}
749
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
544
ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);
545
if(ret != GNUTLS_E_SUCCESS){
546
fprintf_plus(stderr, "Error in GnuTLS prime generation: %s\n",
547
safer_gnutls_strerror(ret));
548
goto globalfail;
549
}
550
551
gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);
750
552
751
553
return 0;
752
554
753
555
globalfail:
754
556
755
gnutls_certificate_free_credentials(mc->cred);
756
gnutls_dh_params_deinit(mc->dh_params);
557
gnutls_certificate_free_credentials(mc.cred);
558
gnutls_global_deinit();
559
gnutls_dh_params_deinit(mc.dh_params);
757
560
return -1;
758
561
}
759
562
760
__attribute__((nonnull, warn_unused_result))
761
static int init_gnutls_session(gnutls_session_t *session,
762
mandos_context *mc){
563
static int init_gnutls_session(gnutls_session_t *session){
763
564
int ret;
764
565
/* GnuTLS session creation */
765
566
do {
777
578
{
778
579
const char *err;
779
580
do {
780
ret = gnutls_priority_set_direct(*session, mc->priority, &err);
581
ret = gnutls_priority_set_direct(*session, mc.priority, &err);
781
582
if(quit_now){
782
583
gnutls_deinit(*session);
783
584
return -1;
794
595
795
596
do {
796
597
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
797
mc->cred);
598
mc.cred);
798
599
if(quit_now){
799
600
gnutls_deinit(*session);
800
601
return -1;
810
611
/* ignore client certificate if any. */
811
612
gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);
812
613
614
gnutls_dh_set_prime_bits(*session, mc.dh_bits);
615
813
616
return 0;
814
617
}
815
618
817
620
static void empty_log(__attribute__((unused)) AvahiLogLevel level,
818
621
__attribute__((unused)) const char *txt){}
819
622
820
/* Set effective uid to 0, return errno */
821
__attribute__((warn_unused_result))
822
int raise_privileges(void){
823
int old_errno = errno;
824
int ret = 0;
825
if(seteuid(0) == -1){
826
ret = errno;
827
}
828
errno = old_errno;
829
return ret;
830
}
831
832
/* Set effective and real user ID to 0. Return errno. */
833
__attribute__((warn_unused_result))
834
int raise_privileges_permanently(void){
835
int old_errno = errno;
836
int ret = raise_privileges();
837
if(ret != 0){
838
errno = old_errno;
839
return ret;
840
}
841
if(setuid(0) == -1){
842
ret = errno;
843
}
844
errno = old_errno;
845
return ret;
846
}
847
848
/* Set effective user ID to unprivileged saved user ID */
849
__attribute__((warn_unused_result))
850
int lower_privileges(void){
851
int old_errno = errno;
852
int ret = 0;
853
if(seteuid(uid) == -1){
854
ret = errno;
855
}
856
errno = old_errno;
857
return ret;
858
}
859
860
/* Lower privileges permanently */
861
__attribute__((warn_unused_result))
862
int lower_privileges_permanently(void){
863
int old_errno = errno;
864
int ret = 0;
865
if(setuid(uid) == -1){
866
ret = errno;
867
}
868
errno = old_errno;
869
return ret;
870
}
871
872
/* Helper function to add_local_route() and delete_local_route() */
873
__attribute__((nonnull, warn_unused_result))
874
static bool add_delete_local_route(const bool add,
875
const char *address,
876
AvahiIfIndex if_index){
877
int ret;
878
char helper[] = "mandos-client-iprouteadddel";
879
char add_arg[] = "add";
880
char delete_arg[] = "delete";
881
char debug_flag[] = "--debug";
882
char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");
883
if(pluginhelperdir == NULL){
884
if(debug){
885
fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"
886
" variable not set; cannot run helper\n");
887
}
888
return false;
889
}
890
891
char interface[IF_NAMESIZE];
892
if(if_indextoname((unsigned int)if_index, interface) == NULL){
893
perror_plus("if_indextoname");
894
return false;
895
}
896
897
int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));
898
if(devnull == -1){
899
perror_plus("open(\"/dev/null\", O_RDONLY)");
900
return false;
901
}
902
pid_t pid = fork();
903
if(pid == 0){
904
/* Child */
905
/* Raise privileges */
906
errno = raise_privileges_permanently();
907
if(errno != 0){
908
perror_plus("Failed to raise privileges");
909
/* _exit(EX_NOPERM); */
910
} else {
911
/* Set group */
912
errno = 0;
913
ret = setgid(0);
914
if(ret == -1){
915
perror_plus("setgid");
916
_exit(EX_NOPERM);
917
}
918
/* Reset supplementary groups */
919
errno = 0;
920
ret = setgroups(0, NULL);
921
if(ret == -1){
922
perror_plus("setgroups");
923
_exit(EX_NOPERM);
924
}
925
}
926
ret = dup2(devnull, STDIN_FILENO);
927
if(ret == -1){
928
perror_plus("dup2(devnull, STDIN_FILENO)");
929
_exit(EX_OSERR);
930
}
931
ret = close(devnull);
932
if(ret == -1){
933
perror_plus("close");
934
_exit(EX_OSERR);
935
}
936
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
937
if(ret == -1){
938
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
939
_exit(EX_OSERR);
940
}
941
int helperdir_fd = (int)TEMP_FAILURE_RETRY(open(pluginhelperdir,
942
O_RDONLY
943
| O_DIRECTORY
944
| O_PATH
945
| O_CLOEXEC));
946
if(helperdir_fd == -1){
947
perror_plus("open");
948
_exit(EX_UNAVAILABLE);
949
}
950
int helper_fd = (int)TEMP_FAILURE_RETRY(openat(helperdir_fd,
951
helper, O_RDONLY));
952
if(helper_fd == -1){
953
perror_plus("openat");
954
close(helperdir_fd);
955
_exit(EX_UNAVAILABLE);
956
}
957
close(helperdir_fd);
958
#ifdef __GNUC__
959
#pragma GCC diagnostic push
960
#pragma GCC diagnostic ignored "-Wcast-qual"
961
#endif
962
if(fexecve(helper_fd, (char *const [])
963
{ helper, add ? add_arg : delete_arg, (char *)address,
964
interface, debug ? debug_flag : NULL, NULL },
965
environ) == -1){
966
#ifdef __GNUC__
967
#pragma GCC diagnostic pop
968
#endif
969
perror_plus("fexecve");
970
_exit(EXIT_FAILURE);
971
}
972
}
973
if(pid == -1){
974
perror_plus("fork");
975
return false;
976
}
977
int status;
978
pid_t pret = -1;
979
errno = 0;
980
do {
981
pret = waitpid(pid, &status, 0);
982
if(pret == -1 and errno == EINTR and quit_now){
983
int errno_raising = 0;
984
if((errno = raise_privileges()) != 0){
985
errno_raising = errno;
986
perror_plus("Failed to raise privileges in order to"
987
" kill helper program");
988
}
989
if(kill(pid, SIGTERM) == -1){
990
perror_plus("kill");
991
}
992
if((errno_raising == 0) and (errno = lower_privileges()) != 0){
993
perror_plus("Failed to lower privileges after killing"
994
" helper program");
995
}
996
return false;
997
}
998
} while(pret == -1 and errno == EINTR);
999
if(pret == -1){
1000
perror_plus("waitpid");
1001
return false;
1002
}
1003
if(WIFEXITED(status)){
1004
if(WEXITSTATUS(status) != 0){
1005
fprintf_plus(stderr, "Error: iprouteadddel exited"
1006
" with status %d\n", WEXITSTATUS(status));
1007
return false;
1008
}
1009
return true;
1010
}
1011
if(WIFSIGNALED(status)){
1012
fprintf_plus(stderr, "Error: iprouteadddel died by"
1013
" signal %d\n", WTERMSIG(status));
1014
return false;
1015
}
1016
fprintf_plus(stderr, "Error: iprouteadddel crashed\n");
1017
return false;
1018
}
1019
1020
__attribute__((nonnull, warn_unused_result))
1021
static bool add_local_route(const char *address,
1022
AvahiIfIndex if_index){
1023
if(debug){
1024
fprintf_plus(stderr, "Adding route to %s\n", address);
1025
}
1026
return add_delete_local_route(true, address, if_index);
1027
}
1028
1029
__attribute__((nonnull, warn_unused_result))
1030
static bool delete_local_route(const char *address,
1031
AvahiIfIndex if_index){
1032
if(debug){
1033
fprintf_plus(stderr, "Removing route to %s\n", address);
1034
}
1035
return add_delete_local_route(false, address, if_index);
1036
}
1037
1038
623
/* Called when a Mandos server is found */
1039
__attribute__((nonnull, warn_unused_result))
1040
624
static int start_mandos_communication(const char *ip, in_port_t port,
1041
625
AvahiIfIndex if_index,
1042
int af, mandos_context *mc){
626
int af){
1043
627
int ret, tcp_sd = -1;
1044
628
ssize_t sret;
1045
struct sockaddr_storage to;
629
union {
630
struct sockaddr_in in;
631
struct sockaddr_in6 in6;
632
} to;
1046
633
char *buffer = NULL;
1047
634
char *decrypted_buffer = NULL;
1048
635
size_t buffer_length = 0;
1051
638
int retval = -1;
1052
639
gnutls_session_t session;
1053
640
int pf; /* Protocol family */
1054
bool route_added = false;
1055
641
1056
642
errno = 0;
1057
643
1073
659
return -1;
1074
660
}
1075
661
1076
/* If the interface is specified and we have a list of interfaces */
1077
if(if_index != AVAHI_IF_UNSPEC and mc->interfaces != NULL){
1078
/* Check if the interface is one of the interfaces we are using */
1079
bool match = false;
1080
{
1081
char *interface = NULL;
1082
while((interface=argz_next(mc->interfaces, mc->interfaces_size,
1083
interface))){
1084
if(if_nametoindex(interface) == (unsigned int)if_index){
1085
match = true;
1086
break;
1087
}
1088
}
1089
}
1090
if(not match){
1091
/* This interface does not match any in the list, so we don't
1092
connect to the server */
1093
if(debug){
1094
char interface[IF_NAMESIZE];
1095
if(if_indextoname((unsigned int)if_index, interface) == NULL){
1096
perror_plus("if_indextoname");
1097
} else {
1098
fprintf_plus(stderr, "Skipping server on non-used interface"
1099
" \"%s\"\n",
1100
if_indextoname((unsigned int)if_index,
1101
interface));
1102
}
1103
}
1104
return -1;
1105
}
1106
}
1107
1108
ret = init_gnutls_session(&session, mc);
662
ret = init_gnutls_session(&session);
1109
663
if(ret != 0){
1110
664
return -1;
1111
665
}
1115
669
PRIuMAX "\n", ip, (uintmax_t)port);
1116
670
}
1117
671
1118
tcp_sd = socket(pf, SOCK_STREAM | SOCK_CLOEXEC, 0);
672
tcp_sd = socket(pf, SOCK_STREAM, 0);
1119
673
if(tcp_sd < 0){
1120
674
int e = errno;
1121
675
perror_plus("socket");
1128
682
goto mandos_end;
1129
683
}
1130
684
685
memset(&to, 0, sizeof(to));
1131
686
if(af == AF_INET6){
1132
struct sockaddr_in6 *to6 = (struct sockaddr_in6 *)&to;
1133
*to6 = (struct sockaddr_in6){ .sin6_family = (sa_family_t)af };
1134
ret = inet_pton(af, ip, &to6->sin6_addr);
687
to.in6.sin6_family = (sa_family_t)af;
688
ret = inet_pton(af, ip, &to.in6.sin6_addr);
1135
689
} else { /* IPv4 */
1136
struct sockaddr_in *to4 = (struct sockaddr_in *)&to;
1137
*to4 = (struct sockaddr_in){ .sin_family = (sa_family_t)af };
1138
ret = inet_pton(af, ip, &to4->sin_addr);
690
to.in.sin_family = (sa_family_t)af;
691
ret = inet_pton(af, ip, &to.in.sin_addr);
1139
692
}
1140
693
if(ret < 0 ){
1141
694
int e = errno;
1150
703
goto mandos_end;
1151
704
}
1152
705
if(af == AF_INET6){
1153
((struct sockaddr_in6 *)&to)->sin6_port = htons(port);
1154
if(IN6_IS_ADDR_LINKLOCAL
1155
(&((struct sockaddr_in6 *)&to)->sin6_addr)){
706
to.in6.sin6_port = htons(port);
707
if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */
708
(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower and
709
-Wunreachable-code*/
1156
710
if(if_index == AVAHI_IF_UNSPEC){
1157
711
fprintf_plus(stderr, "An IPv6 link-local address is"
1158
712
" incomplete without a network interface\n");
1160
714
goto mandos_end;
1161
715
}
1162
716
/* Set the network interface number as scope */
1163
((struct sockaddr_in6 *)&to)->sin6_scope_id = (uint32_t)if_index;
717
to.in6.sin6_scope_id = (uint32_t)if_index;
1164
718
}
1165
719
} else {
1166
((struct sockaddr_in *)&to)->sin_port = htons(port);
720
to.in.sin_port = htons(port); /* Spurious warnings from
721
-Wconversion and
722
-Wunreachable-code */
1167
723
}
1168
724
1169
725
if(quit_now){
1186
742
}
1187
743
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
1188
744
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
1189
if(af == AF_INET6){
1190
ret = getnameinfo((struct sockaddr *)&to,
1191
sizeof(struct sockaddr_in6),
1192
addrstr, sizeof(addrstr), NULL, 0,
1193
NI_NUMERICHOST);
1194
} else {
1195
ret = getnameinfo((struct sockaddr *)&to,
1196
sizeof(struct sockaddr_in),
1197
addrstr, sizeof(addrstr), NULL, 0,
1198
NI_NUMERICHOST);
1199
}
1200
if(ret == EAI_SYSTEM){
1201
perror_plus("getnameinfo");
1202
} else if(ret != 0) {
1203
fprintf_plus(stderr, "getnameinfo: %s", gai_strerror(ret));
1204
} else if(strcmp(addrstr, ip) != 0){
1205
fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);
1206
}
1207
}
1208
1209
if(quit_now){
1210
errno = EINTR;
1211
goto mandos_end;
1212
}
1213
1214
while(true){
1215
if(af == AF_INET6){
1216
ret = connect(tcp_sd, (struct sockaddr *)&to,
1217
sizeof(struct sockaddr_in6));
1218
} else {
1219
ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */
1220
sizeof(struct sockaddr_in));
1221
}
1222
if(ret < 0){
1223
if(((errno == ENETUNREACH) or (errno == EHOSTUNREACH))
1224
and if_index != AVAHI_IF_UNSPEC
1225
and connect_to == NULL
1226
and not route_added and
1227
((af == AF_INET6 and not
1228
IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)
1229
&to)->sin6_addr)))
1230
or (af == AF_INET and
1231
/* Not a a IPv4LL address */
1232
(ntohl(((struct sockaddr_in *)&to)->sin_addr.s_addr)
1233
& 0xFFFF0000L) != 0xA9FE0000L))){
1234
/* Work around Avahi bug - Avahi does not announce link-local
1235
addresses if it has a global address, so local hosts with
1236
*only* a link-local address (e.g. Mandos clients) cannot
1237
connect to a Mandos server announced by Avahi on a server
1238
host with a global address. Work around this by retrying
1239
with an explicit route added with the server's address.
1240
1241
Avahi bug reference:
1242
https://lists.freedesktop.org/archives/avahi/2010-February/001833.html
1243
https://bugs.debian.org/587961
1244
*/
1245
if(debug){
1246
fprintf_plus(stderr, "Mandos server unreachable, trying"
1247
" direct route\n");
1248
}
1249
int e = errno;
1250
route_added = add_local_route(ip, if_index);
1251
if(route_added){
1252
continue;
1253
}
1254
errno = e;
1255
}
1256
if(errno != ECONNREFUSED or debug){
1257
int e = errno;
1258
perror_plus("connect");
1259
errno = e;
1260
}
1261
goto mandos_end;
1262
}
1263
1264
if(quit_now){
1265
errno = EINTR;
1266
goto mandos_end;
1267
}
1268
break;
745
const char *pcret;
746
if(af == AF_INET6){
747
pcret = inet_ntop(af, &(to.in6.sin6_addr), addrstr,
748
sizeof(addrstr));
749
} else {
750
pcret = inet_ntop(af, &(to.in.sin_addr), addrstr,
751
sizeof(addrstr));
752
}
753
if(pcret == NULL){
754
perror_plus("inet_ntop");
755
} else {
756
if(strcmp(addrstr, ip) != 0){
757
fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);
758
}
759
}
760
}
761
762
if(quit_now){
763
errno = EINTR;
764
goto mandos_end;
765
}
766
767
if(af == AF_INET6){
768
ret = connect(tcp_sd, &to.in6, sizeof(to));
769
} else {
770
ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */
771
}
772
if(ret < 0){
773
if ((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){
774
int e = errno;
775
perror_plus("connect");
776
errno = e;
777
}
778
goto mandos_end;
779
}
780
781
if(quit_now){
782
errno = EINTR;
783
goto mandos_end;
1269
784
}
1270
785
1271
786
const char *out = mandos_protocol_version;
1422
937
if(buffer_length > 0){
1423
938
ssize_t decrypted_buffer_size;
1424
939
decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,
1425
&decrypted_buffer, mc);
940
&decrypted_buffer);
1426
941
if(decrypted_buffer_size >= 0){
1427
942
1428
clearerr(stdout);
1429
943
written = 0;
1430
944
while(written < (size_t) decrypted_buffer_size){
1431
945
if(quit_now){
1447
961
}
1448
962
written += (size_t)ret;
1449
963
}
1450
ret = fflush(stdout);
1451
if(ret != 0){
1452
int e = errno;
1453
if(debug){
1454
fprintf_plus(stderr, "Error writing encrypted data: %s\n",
1455
strerror(errno));
1456
}
1457
errno = e;
1458
goto mandos_end;
1459
}
1460
964
retval = 0;
1461
965
}
1462
966
}
1465
969
1466
970
mandos_end:
1467
971
{
1468
if(route_added){
1469
if(not delete_local_route(ip, if_index)){
1470
fprintf_plus(stderr, "Failed to delete local route to %s on"
1471
" interface %d", ip, if_index);
1472
}
1473
}
1474
972
int e = errno;
1475
973
free(decrypted_buffer);
1476
974
free(buffer);
1477
975
if(tcp_sd >= 0){
1478
ret = close(tcp_sd);
976
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
1479
977
}
1480
978
if(ret == -1){
1481
979
if(e == 0){
1493
991
return retval;
1494
992
}
1495
993
1496
__attribute__((nonnull))
1497
994
static void resolve_callback(AvahiSServiceResolver *r,
1498
995
AvahiIfIndex interface,
1499
996
AvahiProtocol proto,
1507
1004
AVAHI_GCC_UNUSED AvahiStringList *txt,
1508
1005
AVAHI_GCC_UNUSED AvahiLookupResultFlags
1509
1006
flags,
1510
void *mc){
1007
AVAHI_GCC_UNUSED void* userdata){
1511
1008
if(r == NULL){
1512
1009
return;
1513
1010
}
1516
1013
timed out */
1517
1014
1518
1015
if(quit_now){
1519
avahi_s_service_resolver_free(r);
1520
1016
return;
1521
1017
}
1522
1018
1526
1022
fprintf_plus(stderr, "(Avahi Resolver) Failed to resolve service "
1527
1023
"'%s' of type '%s' in domain '%s': %s\n", name, type,
1528
1024
domain,
1529
avahi_strerror(avahi_server_errno
1530
(((mandos_context*)mc)->server)));
1025
avahi_strerror(avahi_server_errno(mc.server)));
1531
1026
break;
1532
1027
1533
1028
case AVAHI_RESOLVER_FOUND:
1541
1036
}
1542
1037
int ret = start_mandos_communication(ip, (in_port_t)port,
1543
1038
interface,
1544
avahi_proto_to_af(proto),
1545
mc);
1039
avahi_proto_to_af(proto));
1546
1040
if(ret == 0){
1547
avahi_simple_poll_quit(simple_poll);
1041
avahi_simple_poll_quit(mc.simple_poll);
1548
1042
} else {
1549
1043
if(not add_server(ip, (in_port_t)port, interface,
1550
avahi_proto_to_af(proto),
1551
&((mandos_context*)mc)->current_server)){
1044
avahi_proto_to_af(proto))){
1552
1045
fprintf_plus(stderr, "Failed to add server \"%s\" to server"
1553
1046
" list\n", name);
1554
1047
}
1567
1060
const char *domain,
1568
1061
AVAHI_GCC_UNUSED AvahiLookupResultFlags
1569
1062
flags,
1570
void *mc){
1063
AVAHI_GCC_UNUSED void* userdata){
1571
1064
if(b == NULL){
1572
1065
return;
1573
1066
}
1584
1077
case AVAHI_BROWSER_FAILURE:
1585
1078
1586
1079
fprintf_plus(stderr, "(Avahi browser) %s\n",
1587
avahi_strerror(avahi_server_errno
1588
(((mandos_context*)mc)->server)));
1589
avahi_simple_poll_quit(simple_poll);
1080
avahi_strerror(avahi_server_errno(mc.server)));
1081
avahi_simple_poll_quit(mc.simple_poll);
1590
1082
return;
1591
1083
1592
1084
case AVAHI_BROWSER_NEW:
1595
1087
the callback function is called the Avahi server will free the
1596
1088
resolver for us. */
1597
1089
1598
if(avahi_s_service_resolver_new(((mandos_context*)mc)->server,
1599
interface, protocol, name, type,
1600
domain, protocol, 0,
1601
resolve_callback, mc) == NULL)
1090
if(avahi_s_service_resolver_new(mc.server, interface, protocol,
1091
name, type, domain, protocol, 0,
1092
resolve_callback, NULL) == NULL)
1602
1093
fprintf_plus(stderr, "Avahi: Failed to resolve service '%s':"
1603
1094
" %s\n", name,
1604
avahi_strerror(avahi_server_errno
1605
(((mandos_context*)mc)->server)));
1095
avahi_strerror(avahi_server_errno(mc.server)));
1606
1096
break;
1607
1097
1608
1098
case AVAHI_BROWSER_REMOVE:
1627
1117
signal_received = sig;
1628
1118
int old_errno = errno;
1629
1119
/* set main loop to exit */
1630
if(simple_poll != NULL){
1631
avahi_simple_poll_quit(simple_poll);
1120
if(mc.simple_poll != NULL){
1121
avahi_simple_poll_quit(mc.simple_poll);
1632
1122
}
1633
1123
errno = old_errno;
1634
1124
}
1635
1125
1636
__attribute__((nonnull, warn_unused_result))
1637
1126
bool get_flags(const char *ifname, struct ifreq *ifr){
1638
1127
int ret;
1639
int old_errno;
1128
error_t ret_errno;
1640
1129
1641
1130
int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1642
1131
if(s < 0){
1643
old_errno = errno;
1132
ret_errno = errno;
1644
1133
perror_plus("socket");
1645
errno = old_errno;
1134
errno = ret_errno;
1646
1135
return false;
1647
1136
}
1648
strncpy(ifr->ifr_name, ifname, IF_NAMESIZE);
1649
ifr->ifr_name[IF_NAMESIZE-1] = '\0'; /* NUL terminate */
1137
strcpy(ifr->ifr_name, ifname);
1650
1138
ret = ioctl(s, SIOCGIFFLAGS, ifr);
1651
1139
if(ret == -1){
1652
1140
if(debug){
1653
old_errno = errno;
1141
ret_errno = errno;
1654
1142
perror_plus("ioctl SIOCGIFFLAGS");
1655
errno = old_errno;
1143
errno = ret_errno;
1656
1144
}
1657
1145
return false;
1658
1146
}
1659
1147
return true;
1660
1148
}
1661
1149
1662
__attribute__((nonnull, warn_unused_result))
1663
1150
bool good_flags(const char *ifname, const struct ifreq *ifr){
1664
1151
1665
1152
/* Reject the loopback device */
1707
1194
* corresponds to an acceptable network device.
1708
1195
* (This function is passed to scandir(3) as a filter function.)
1709
1196
*/
1710
__attribute__((nonnull, warn_unused_result))
1711
1197
int good_interface(const struct dirent *if_entry){
1712
1198
if(if_entry->d_name[0] == '.'){
1713
1199
return 0;
1731
1217
/*
1732
1218
* This function determines if a network interface is up.
1733
1219
*/
1734
__attribute__((nonnull, warn_unused_result))
1735
1220
bool interface_is_up(const char *interface){
1736
1221
struct ifreq ifr;
1737
1222
if(not get_flags(interface, &ifr)){
1748
1233
/*
1749
1234
* This function determines if a network interface is running
1750
1235
*/
1751
__attribute__((nonnull, warn_unused_result))
1752
1236
bool interface_is_running(const char *interface){
1753
1237
struct ifreq ifr;
1754
1238
if(not get_flags(interface, &ifr)){
1762
1246
return (bool)(ifr.ifr_flags & IFF_RUNNING);
1763
1247
}
1764
1248
1765
__attribute__((nonnull, pure, warn_unused_result))
1766
1249
int notdotentries(const struct dirent *direntry){
1767
1250
/* Skip "." and ".." */
1768
1251
if(direntry->d_name[0] == '.'
1775
1258
}
1776
1259
1777
1260
/* Is this directory entry a runnable program? */
1778
__attribute__((nonnull, warn_unused_result))
1779
1261
int runnable_hook(const struct dirent *direntry){
1780
1262
int ret;
1781
1263
size_t sret;
1789
1271
sret = strspn(direntry->d_name, "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
1790
1272
"abcdefghijklmnopqrstuvwxyz"
1791
1273
"0123456789"
1792
"_.-");
1274
"_-");
1793
1275
if((direntry->d_name)[sret] != '\0'){
1794
1276
/* Contains non-allowed characters */
1795
1277
if(debug){
1799
1281
return 0;
1800
1282
}
1801
1283
1802
ret = fstatat(hookdir_fd, direntry->d_name, &st, 0);
1284
char *fullname = NULL;
1285
ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);
1286
if(ret < 0){
1287
perror_plus("asprintf");
1288
return 0;
1289
}
1290
1291
ret = stat(fullname, &st);
1803
1292
if(ret == -1){
1804
1293
if(debug){
1805
1294
perror_plus("Could not stat hook");
1829
1318
return 1;
1830
1319
}
1831
1320
1832
__attribute__((nonnull, warn_unused_result))
1833
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,
1834
mandos_context *mc){
1321
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){
1835
1322
int ret;
1836
1323
struct timespec now;
1837
1324
struct timespec waited_time;
1838
1325
intmax_t block_time;
1839
1326
1840
1327
while(true){
1841
if(mc->current_server == NULL){
1842
if(debug){
1328
if(mc.current_server == NULL){
1329
if (debug){
1843
1330
fprintf_plus(stderr, "Wait until first server is found."
1844
1331
" No timeout!\n");
1845
1332
}
1846
1333
ret = avahi_simple_poll_iterate(s, -1);
1847
1334
} else {
1848
if(debug){
1335
if (debug){
1849
1336
fprintf_plus(stderr, "Check current_server if we should run"
1850
1337
" it, or wait\n");
1851
1338
}
1858
1345
/* Calculating in ms how long time between now and server
1859
1346
who we visted longest time ago. Now - last seen. */
1860
1347
waited_time.tv_sec = (now.tv_sec
1861
- mc->current_server->last_seen.tv_sec);
1348
- mc.current_server->last_seen.tv_sec);
1862
1349
waited_time.tv_nsec = (now.tv_nsec
1863
- mc->current_server->last_seen.tv_nsec);
1350
- mc.current_server->last_seen.tv_nsec);
1864
1351
/* total time is 10s/10,000ms.
1865
1352
Converting to s from ms by dividing by 1,000,
1866
1353
and ns to ms by dividing by 1,000,000. */
1868
1355
- ((intmax_t)waited_time.tv_sec * 1000))
1869
1356
- ((intmax_t)waited_time.tv_nsec / 1000000));
1870
1357
1871
if(debug){
1358
if (debug){
1872
1359
fprintf_plus(stderr, "Blocking for %" PRIdMAX " ms\n",
1873
1360
block_time);
1874
1361
}
1875
1362
1876
1363
if(block_time <= 0){
1877
ret = start_mandos_communication(mc->current_server->ip,
1878
mc->current_server->port,
1879
mc->current_server->if_index,
1880
mc->current_server->af, mc);
1364
ret = start_mandos_communication(mc.current_server->ip,
1365
mc.current_server->port,
1366
mc.current_server->if_index,
1367
mc.current_server->af);
1881
1368
if(ret == 0){
1882
avahi_simple_poll_quit(s);
1369
avahi_simple_poll_quit(mc.simple_poll);
1883
1370
return 0;
1884
1371
}
1885
1372
ret = clock_gettime(CLOCK_MONOTONIC,
1886
&mc->current_server->last_seen);
1373
&mc.current_server->last_seen);
1887
1374
if(ret == -1){
1888
1375
perror_plus("clock_gettime");
1889
1376
return -1;
1890
1377
}
1891
mc->current_server = mc->current_server->next;
1378
mc.current_server = mc.current_server->next;
1892
1379
block_time = 0; /* Call avahi to find new Mandos
1893
1380
servers, but don't block */
1894
1381
}
1896
1383
ret = avahi_simple_poll_iterate(s, (int)block_time);
1897
1384
}
1898
1385
if(ret != 0){
1899
if(ret > 0 or errno != EINTR){
1386
if (ret > 0 or errno != EINTR){
1900
1387
return (ret != 1) ? ret : 0;
1901
1388
}
1902
1389
}
1903
1390
}
1904
1391
}
1905
1392
1906
__attribute__((nonnull))
1907
void run_network_hooks(const char *mode, const char *interface,
1393
/* Set effective uid to 0, return errno */
1394
error_t raise_privileges(void){
1395
error_t old_errno = errno;
1396
error_t ret_errno = 0;
1397
if(seteuid(0) == -1){
1398
ret_errno = errno;
1399
perror_plus("seteuid");
1400
}
1401
errno = old_errno;
1402
return ret_errno;
1403
}
1404
1405
/* Set effective and real user ID to 0. Return errno. */
1406
error_t raise_privileges_permanently(void){
1407
error_t old_errno = errno;
1408
error_t ret_errno = raise_privileges();
1409
if(ret_errno != 0){
1410
errno = old_errno;
1411
return ret_errno;
1412
}
1413
if(setuid(0) == -1){
1414
ret_errno = errno;
1415
perror_plus("seteuid");
1416
}
1417
errno = old_errno;
1418
return ret_errno;
1419
}
1420
1421
/* Set effective user ID to unprivileged saved user ID */
1422
error_t lower_privileges(void){
1423
error_t old_errno = errno;
1424
error_t ret_errno = 0;
1425
if(seteuid(uid) == -1){
1426
ret_errno = errno;
1427
perror_plus("seteuid");
1428
}
1429
errno = old_errno;
1430
return ret_errno;
1431
}
1432
1433
/* Lower privileges permanently */
1434
error_t lower_privileges_permanently(void){
1435
error_t old_errno = errno;
1436
error_t ret_errno = 0;
1437
if(setuid(uid) == -1){
1438
ret_errno = errno;
1439
perror_plus("setuid");
1440
}
1441
errno = old_errno;
1442
return ret_errno;
1443
}
1444
1445
bool run_network_hooks(const char *mode, const char *interface,
1908
1446
const float delay){
1909
struct dirent **direntries = NULL;
1910
if(hookdir_fd == -1){
1911
hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH
1912
| O_CLOEXEC);
1913
if(hookdir_fd == -1){
1914
if(errno == ENOENT){
1915
if(debug){
1916
fprintf_plus(stderr, "Network hook directory \"%s\" not"
1917
" found\n", hookdir);
1918
}
1919
} else {
1920
perror_plus("open");
1921
}
1922
return;
1923
}
1924
}
1925
int numhooks = scandirat(hookdir_fd, ".", &direntries,
1926
runnable_hook, alphasort);
1447
struct dirent **direntries;
1448
struct dirent *direntry;
1449
int ret;
1450
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1451
alphasort);
1927
1452
if(numhooks == -1){
1928
1453
perror_plus("scandir");
1929
return;
1930
}
1931
struct dirent *direntry;
1932
int ret;
1933
int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));
1934
if(devnull == -1){
1935
perror_plus("open(\"/dev/null\", O_RDONLY)");
1936
return;
1937
}
1938
for(int i = 0; i < numhooks; i++){
1939
direntry = direntries[i];
1940
if(debug){
1941
fprintf_plus(stderr, "Running network hook \"%s\"\n",
1942
direntry->d_name);
1943
}
1944
pid_t hook_pid = fork();
1945
if(hook_pid == 0){
1946
/* Child */
1947
/* Raise privileges */
1948
errno = raise_privileges_permanently();
1949
if(errno != 0){
1950
perror_plus("Failed to raise privileges");
1951
_exit(EX_NOPERM);
1952
}
1953
/* Set group */
1954
errno = 0;
1955
ret = setgid(0);
1956
if(ret == -1){
1957
perror_plus("setgid");
1958
_exit(EX_NOPERM);
1959
}
1960
/* Reset supplementary groups */
1961
errno = 0;
1962
ret = setgroups(0, NULL);
1963
if(ret == -1){
1964
perror_plus("setgroups");
1965
_exit(EX_NOPERM);
1966
}
1967
ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);
1968
if(ret == -1){
1969
perror_plus("setenv");
1970
_exit(EX_OSERR);
1971
}
1972
ret = setenv("DEVICE", interface, 1);
1973
if(ret == -1){
1974
perror_plus("setenv");
1975
_exit(EX_OSERR);
1976
}
1977
ret = setenv("VERBOSITY", debug ? "1" : "0", 1);
1978
if(ret == -1){
1979
perror_plus("setenv");
1980
_exit(EX_OSERR);
1981
}
1982
ret = setenv("MODE", mode, 1);
1983
if(ret == -1){
1984
perror_plus("setenv");
1985
_exit(EX_OSERR);
1986
}
1987
char *delaystring;
1988
ret = asprintf(&delaystring, "%f", (double)delay);
1989
if(ret == -1){
1454
} else {
1455
int devnull = open("/dev/null", O_RDONLY);
1456
for(int i = 0; i < numhooks; i++){
1457
direntry = direntries[i];
1458
char *fullname = NULL;
1459
ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);
1460
if(ret < 0){
1990
1461
perror_plus("asprintf");
1991
_exit(EX_OSERR);
1992
}
1993
ret = setenv("DELAY", delaystring, 1);
1994
if(ret == -1){
1462
continue;
1463
}
1464
if(debug){
1465
fprintf_plus(stderr, "Running network hook \"%s\"\n",
1466
direntry->d_name);
1467
}
1468
pid_t hook_pid = fork();
1469
if(hook_pid == 0){
1470
/* Child */
1471
/* Raise privileges */
1472
raise_privileges_permanently();
1473
/* Set group */
1474
errno = 0;
1475
ret = setgid(0);
1476
if(ret == -1){
1477
perror_plus("setgid");
1478
}
1479
/* Reset supplementary groups */
1480
errno = 0;
1481
ret = setgroups(0, NULL);
1482
if(ret == -1){
1483
perror_plus("setgroups");
1484
}
1485
dup2(devnull, STDIN_FILENO);
1486
close(devnull);
1487
dup2(STDERR_FILENO, STDOUT_FILENO);
1488
ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);
1489
if(ret == -1){
1490
perror_plus("setenv");
1491
_exit(EX_OSERR);
1492
}
1493
ret = setenv("DEVICE", interface, 1);
1494
if(ret == -1){
1495
perror_plus("setenv");
1496
_exit(EX_OSERR);
1497
}
1498
ret = setenv("VERBOSITY", debug ? "1" : "0", 1);
1499
if(ret == -1){
1500
perror_plus("setenv");
1501
_exit(EX_OSERR);
1502
}
1503
ret = setenv("MODE", mode, 1);
1504
if(ret == -1){
1505
perror_plus("setenv");
1506
_exit(EX_OSERR);
1507
}
1508
char *delaystring;
1509
ret = asprintf(&delaystring, "%f", delay);
1510
if(ret == -1){
1511
perror_plus("asprintf");
1512
_exit(EX_OSERR);
1513
}
1514
ret = setenv("DELAY", delaystring, 1);
1515
if(ret == -1){
1516
free(delaystring);
1517
perror_plus("setenv");
1518
_exit(EX_OSERR);
1519
}
1995
1520
free(delaystring);
1996
perror_plus("setenv");
1997
_exit(EX_OSERR);
1998
}
1999
free(delaystring);
2000
if(connect_to != NULL){
2001
ret = setenv("CONNECT", connect_to, 1);
2002
if(ret == -1){
2003
perror_plus("setenv");
2004
_exit(EX_OSERR);
2005
}
2006
}
2007
int hook_fd = (int)TEMP_FAILURE_RETRY(openat(hookdir_fd,
2008
direntry->d_name,
2009
O_RDONLY));
2010
if(hook_fd == -1){
2011
perror_plus("openat");
2012
_exit(EXIT_FAILURE);
2013
}
2014
if(close(hookdir_fd) == -1){
2015
perror_plus("close");
2016
_exit(EXIT_FAILURE);
2017
}
2018
ret = dup2(devnull, STDIN_FILENO);
2019
if(ret == -1){
2020
perror_plus("dup2(devnull, STDIN_FILENO)");
2021
_exit(EX_OSERR);
2022
}
2023
ret = close(devnull);
2024
if(ret == -1){
2025
perror_plus("close");
2026
_exit(EX_OSERR);
2027
}
2028
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
2029
if(ret == -1){
2030
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
2031
_exit(EX_OSERR);
2032
}
2033
if(fexecve(hook_fd, (char *const []){ direntry->d_name, NULL },
2034
environ) == -1){
2035
perror_plus("fexecve");
2036
_exit(EXIT_FAILURE);
2037
}
2038
} else {
2039
if(hook_pid == -1){
2040
perror_plus("fork");
2041
free(direntry);
2042
continue;
2043
}
2044
int status;
2045
if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){
2046
perror_plus("waitpid");
2047
free(direntry);
2048
continue;
2049
}
2050
if(WIFEXITED(status)){
2051
if(WEXITSTATUS(status) != 0){
2052
fprintf_plus(stderr, "Warning: network hook \"%s\" exited"
2053
" with status %d\n", direntry->d_name,
2054
WEXITSTATUS(status));
2055
free(direntry);
2056
continue;
2057
}
2058
} else if(WIFSIGNALED(status)){
2059
fprintf_plus(stderr, "Warning: network hook \"%s\" died by"
2060
" signal %d\n", direntry->d_name,
2061
WTERMSIG(status));
2062
free(direntry);
2063
continue;
1521
if(connect_to != NULL){
1522
ret = setenv("CONNECT", connect_to, 1);
1523
if(ret == -1){
1524
perror_plus("setenv");
1525
_exit(EX_OSERR);
1526
}
1527
}
1528
if(execl(fullname, direntry->d_name, mode, NULL) == -1){
1529
perror_plus("execl");
1530
_exit(EXIT_FAILURE);
1531
}
2064
1532
} else {
2065
fprintf_plus(stderr, "Warning: network hook \"%s\""
2066
" crashed\n", direntry->d_name);
2067
free(direntry);
2068
continue;
2069
}
2070
}
2071
if(debug){
2072
fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",
2073
direntry->d_name);
2074
}
2075
free(direntry);
2076
}
2077
free(direntries);
2078
if(close(hookdir_fd) == -1){
2079
perror_plus("close");
2080
} else {
2081
hookdir_fd = -1;
2082
}
2083
close(devnull);
1533
int status;
1534
if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){
1535
perror_plus("waitpid");
1536
free(fullname);
1537
continue;
1538
}
1539
if(WIFEXITED(status)){
1540
if(WEXITSTATUS(status) != 0){
1541
fprintf_plus(stderr, "Warning: network hook \"%s\" exited"
1542
" with status %d\n", direntry->d_name,
1543
WEXITSTATUS(status));
1544
free(fullname);
1545
continue;
1546
}
1547
} else if(WIFSIGNALED(status)){
1548
fprintf_plus(stderr, "Warning: network hook \"%s\" died by"
1549
" signal %d\n", direntry->d_name,
1550
WTERMSIG(status));
1551
free(fullname);
1552
continue;
1553
} else {
1554
fprintf_plus(stderr, "Warning: network hook \"%s\""
1555
" crashed\n", direntry->d_name);
1556
free(fullname);
1557
continue;
1558
}
1559
}
1560
free(fullname);
1561
if(debug){
1562
fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",
1563
direntry->d_name);
1564
}
1565
}
1566
close(devnull);
1567
}
1568
return true;
2084
1569
}
2085
1570
2086
__attribute__((nonnull, warn_unused_result))
2087
int bring_up_interface(const char *const interface,
2088
const float delay){
2089
int old_errno = errno;
2090
int ret;
1571
error_t bring_up_interface(const char *const interface,
1572
const float delay){
1573
int sd = -1;
1574
error_t old_errno = errno;
1575
error_t ret_errno = 0;
1576
int ret, ret_setflags;
2091
1577
struct ifreq network;
2092
1578
unsigned int if_index = if_nametoindex(interface);
2093
1579
if(if_index == 0){
2102
1588
}
2103
1589
2104
1590
if(not interface_is_up(interface)){
2105
int ret_errno = 0;
2106
int ioctl_errno = 0;
2107
if(not get_flags(interface, &network)){
1591
if(not get_flags(interface, &network) and debug){
2108
1592
ret_errno = errno;
2109
1593
fprintf_plus(stderr, "Failed to get flags for interface "
2110
1594
"\"%s\"\n", interface);
2111
errno = old_errno;
2112
1595
return ret_errno;
2113
1596
}
2114
network.ifr_flags |= IFF_UP; /* set flag */
1597
network.ifr_flags |= IFF_UP;
2115
1598
2116
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
2117
if(sd == -1){
1599
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1600
if(sd < 0){
2118
1601
ret_errno = errno;
2119
1602
perror_plus("socket");
2120
1603
errno = old_errno;
2121
1604
return ret_errno;
2122
1605
}
2123
1606
2124
1607
if(quit_now){
2125
ret = close(sd);
2126
if(ret == -1){
2127
perror_plus("close");
2128
}
1608
close(sd);
2129
1609
errno = old_errno;
2130
1610
return EINTR;
2131
1611
}
2135
1615
interface);
2136
1616
}
2137
1617
2138
/* Raise privileges */
2139
ret_errno = raise_privileges();
2140
if(ret_errno != 0){
2141
errno = ret_errno;
2142
perror_plus("Failed to raise privileges");
2143
}
1618
/* Raise priviliges */
1619
raise_privileges();
2144
1620
2145
1621
#ifdef __linux__
2146
int ret_linux;
2147
bool restore_loglevel = false;
2148
if(ret_errno == 0){
2149
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
2150
messages about the network interface to mess up the prompt */
2151
ret_linux = klogctl(8, NULL, 5);
2152
if(ret_linux == -1){
2153
perror_plus("klogctl");
2154
} else {
2155
restore_loglevel = true;
2156
}
1622
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1623
messages about the network interface to mess up the prompt */
1624
int ret_linux = klogctl(8, NULL, 5);
1625
bool restore_loglevel = true;
1626
if(ret_linux == -1){
1627
restore_loglevel = false;
1628
perror_plus("klogctl");
2157
1629
}
2158
1630
#endif /* __linux__ */
2159
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
2160
ioctl_errno = errno;
1631
ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1632
ret_errno = errno;
2161
1633
#ifdef __linux__
2162
1634
if(restore_loglevel){
2163
1635
ret_linux = klogctl(7, NULL, 0);
2167
1639
}
2168
1640
#endif /* __linux__ */
2169
1641
2170
/* If raise_privileges() succeeded above */
2171
if(ret_errno == 0){
2172
/* Lower privileges */
2173
ret_errno = lower_privileges();
2174
if(ret_errno != 0){
2175
errno = ret_errno;
2176
perror_plus("Failed to lower privileges");
2177
}
2178
}
1642
/* Lower privileges */
1643
lower_privileges();
2179
1644
2180
1645
/* Close the socket */
2181
ret = close(sd);
1646
ret = (int)TEMP_FAILURE_RETRY(close(sd));
2182
1647
if(ret == -1){
2183
1648
perror_plus("close");
2184
1649
}
2185
1650
2186
1651
if(ret_setflags == -1){
2187
errno = ioctl_errno;
1652
errno = ret_errno;
2188
1653
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
2189
1654
errno = old_errno;
2190
return ioctl_errno;
1655
return ret_errno;
2191
1656
}
2192
1657
} else if(debug){
2193
1658
fprintf_plus(stderr, "Interface \"%s\" is already up; good\n",
2211
1676
return 0;
2212
1677
}
2213
1678
2214
__attribute__((nonnull, warn_unused_result))
2215
int take_down_interface(const char *const interface){
2216
int old_errno = errno;
1679
error_t take_down_interface(const char *const interface){
1680
int sd = -1;
1681
error_t old_errno = errno;
1682
error_t ret_errno = 0;
1683
int ret, ret_setflags;
2217
1684
struct ifreq network;
2218
1685
unsigned int if_index = if_nametoindex(interface);
2219
1686
if(if_index == 0){
2222
1689
return ENXIO;
2223
1690
}
2224
1691
if(interface_is_up(interface)){
2225
int ret_errno = 0;
2226
int ioctl_errno = 0;
2227
1692
if(not get_flags(interface, &network) and debug){
2228
1693
ret_errno = errno;
2229
1694
fprintf_plus(stderr, "Failed to get flags for interface "
2230
1695
"\"%s\"\n", interface);
2231
errno = old_errno;
2232
1696
return ret_errno;
2233
1697
}
2234
1698
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
2235
1699
2236
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
2237
if(sd == -1){
1700
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1701
if(sd < 0){
2238
1702
ret_errno = errno;
2239
1703
perror_plus("socket");
2240
1704
errno = old_errno;
2246
1710
interface);
2247
1711
}
2248
1712
2249
/* Raise privileges */
2250
ret_errno = raise_privileges();
2251
if(ret_errno != 0){
2252
errno = ret_errno;
2253
perror_plus("Failed to raise privileges");
2254
}
2255
2256
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
2257
ioctl_errno = errno;
2258
2259
/* If raise_privileges() succeeded above */
2260
if(ret_errno == 0){
2261
/* Lower privileges */
2262
ret_errno = lower_privileges();
2263
if(ret_errno != 0){
2264
errno = ret_errno;
2265
perror_plus("Failed to lower privileges");
2266
}
2267
}
1713
/* Raise priviliges */
1714
raise_privileges();
1715
1716
ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1717
ret_errno = errno;
1718
1719
/* Lower privileges */
1720
lower_privileges();
2268
1721
2269
1722
/* Close the socket */
2270
int ret = close(sd);
1723
ret = (int)TEMP_FAILURE_RETRY(close(sd));
2271
1724
if(ret == -1){
2272
1725
perror_plus("close");
2273
1726
}
2274
1727
2275
1728
if(ret_setflags == -1){
2276
errno = ioctl_errno;
1729
errno = ret_errno;
2277
1730
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
2278
1731
errno = old_errno;
2279
return ioctl_errno;
1732
return ret_errno;
2280
1733
}
2281
1734
} else if(debug){
2282
1735
fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",
2288
1741
}
2289
1742
2290
1743
int main(int argc, char *argv[]){
2291
mandos_context mc = { .server = NULL, .dh_bits = 0,
2292
.priority = "SECURE256:!CTYPE-X.509"
2293
":+CTYPE-OPENPGP:!RSA:+SIGN-DSA-SHA256",
2294
.current_server = NULL, .interfaces = NULL,
2295
.interfaces_size = 0 };
2296
1744
AvahiSServiceBrowser *sb = NULL;
2297
1745
error_t ret_errno;
2298
1746
int ret;
2299
1747
intmax_t tmpmax;
2300
1748
char *tmp;
2301
1749
int exitcode = EXIT_SUCCESS;
1750
char *interfaces = NULL;
1751
size_t interfaces_size = 0;
2302
1752
char *interfaces_to_take_down = NULL;
2303
1753
size_t interfaces_to_take_down_size = 0;
2304
char run_tempdir[] = "/run/tmp/mandosXXXXXX";
2305
char old_tempdir[] = "/tmp/mandosXXXXXX";
2306
char *tempdir = NULL;
1754
char tempdir[] = "/tmp/mandosXXXXXX";
1755
bool tempdir_created = false;
2307
1756
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
2308
1757
const char *seckey = PATHDIR "/" SECKEY;
2309
1758
const char *pubkey = PATHDIR "/" PUBKEY;
2310
const char *dh_params_file = NULL;
2311
1759
char *interfaces_hooks = NULL;
1760
size_t interfaces_hooks_size = 0;
2312
1761
2313
1762
bool gnutls_initialized = false;
2314
1763
bool gpgme_initialized = false;
2366
1815
.doc = "Bit length of the prime number used in the"
2367
1816
" Diffie-Hellman key exchange",
2368
1817
.group = 2 },
2369
{ .name = "dh-params", .key = 134,
2370
.arg = "FILE",
2371
.doc = "PEM-encoded PKCS#3 file with pre-generated parameters"
2372
" for the Diffie-Hellman key exchange",
2373
.group = 2 },
2374
1818
{ .name = "priority", .key = 130,
2375
1819
.arg = "STRING",
2376
1820
.doc = "GnuTLS priority string for the TLS handshake",
2410
1854
connect_to = arg;
2411
1855
break;
2412
1856
case 'i': /* --interface */
2413
ret_errno = argz_add_sep(&mc.interfaces, &mc.interfaces_size,
2414
arg, (int)',');
1857
ret_errno = argz_add_sep(&interfaces, &interfaces_size, arg,
1858
(int)',');
2415
1859
if(ret_errno != 0){
2416
1860
argp_error(state, "%s", strerror(ret_errno));
2417
1861
}
2431
1875
}
2432
1876
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
2433
1877
break;
2434
case 134: /* --dh-params */
2435
dh_params_file = arg;
2436
break;
2437
1878
case 130: /* --priority */
2438
1879
mc.priority = arg;
2439
1880
break;
2479
1920
.args_doc = "",
2480
1921
.doc = "Mandos client -- Get and decrypt"
2481
1922
" passwords from a Mandos server" };
2482
ret_errno = argp_parse(&argp, argc, argv,
2483
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
2484
switch(ret_errno){
1923
ret = argp_parse(&argp, argc, argv,
1924
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
1925
switch(ret){
2485
1926
case 0:
2486
1927
break;
2487
1928
case ENOMEM:
2488
1929
default:
2489
errno = ret_errno;
1930
errno = ret;
2490
1931
perror_plus("argp_parse");
2491
1932
exitcode = EX_OSERR;
2492
1933
goto end;
2495
1936
goto end;
2496
1937
}
2497
1938
}
2498
1939
2499
1940
{
2500
1941
/* Work around Debian bug #633582:
2501
<https://bugs.debian.org/633582> */
1942
<http://bugs.debian.org/633582> */
2502
1943
2503
/* Re-raise privileges */
2504
ret = raise_privileges();
2505
if(ret != 0){
2506
errno = ret;
2507
perror_plus("Failed to raise privileges");
2508
} else {
1944
/* Re-raise priviliges */
1945
if(raise_privileges() == 0){
2509
1946
struct stat st;
2510
1947
2511
1948
if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){
2525
1962
}
2526
1963
}
2527
1964
}
2528
close(seckey_fd);
1965
TEMP_FAILURE_RETRY(close(seckey_fd));
2529
1966
}
2530
1967
}
2531
1968
2532
1969
if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){
2533
1970
int pubkey_fd = open(pubkey, O_RDONLY);
2534
1971
if(pubkey_fd == -1){
2546
1983
}
2547
1984
}
2548
1985
}
2549
close(pubkey_fd);
2550
}
2551
}
2552
2553
if(dh_params_file != NULL
2554
and strcmp(dh_params_file, PATHDIR "/dhparams.pem" ) == 0){
2555
int dhparams_fd = open(dh_params_file, O_RDONLY);
2556
if(dhparams_fd == -1){
2557
perror_plus("open");
2558
} else {
2559
ret = (int)TEMP_FAILURE_RETRY(fstat(dhparams_fd, &st));
2560
if(ret == -1){
2561
perror_plus("fstat");
2562
} else {
2563
if(S_ISREG(st.st_mode)
2564
and st.st_uid == 0 and st.st_gid == 0){
2565
ret = fchown(dhparams_fd, uid, gid);
2566
if(ret == -1){
2567
perror_plus("fchown");
2568
}
2569
}
2570
}
2571
close(dhparams_fd);
2572
}
2573
}
2574
1986
TEMP_FAILURE_RETRY(close(pubkey_fd));
1987
}
1988
}
1989
2575
1990
/* Lower privileges */
2576
ret = lower_privileges();
2577
if(ret != 0){
2578
errno = ret;
2579
perror_plus("Failed to lower privileges");
1991
errno = 0;
1992
ret = seteuid(uid);
1993
if(ret == -1){
1994
perror_plus("seteuid");
2580
1995
}
2581
1996
}
2582
1997
}
2583
1998
2584
/* Remove invalid interface names (except "none") */
1999
/* Remove empty interface names */
2585
2000
{
2586
2001
char *interface = NULL;
2587
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2002
while((interface = argz_next(interfaces, interfaces_size,
2588
2003
interface))){
2589
if(strcmp(interface, "none") != 0
2590
and if_nametoindex(interface) == 0){
2591
if(interface[0] != '\0'){
2004
if(if_nametoindex(interface) == 0){
2005
if(interface[0] != '\0' and strcmp(interface, "none") != 0){
2592
2006
fprintf_plus(stderr, "Not using nonexisting interface"
2593
2007
" \"%s\"\n", interface);
2594
2008
}
2595
argz_delete(&mc.interfaces, &mc.interfaces_size, interface);
2009
argz_delete(&interfaces, &interfaces_size, interface);
2596
2010
interface = NULL;
2597
2011
}
2598
2012
}
2600
2014
2601
2015
/* Run network hooks */
2602
2016
{
2603
if(mc.interfaces != NULL){
2604
interfaces_hooks = malloc(mc.interfaces_size);
2605
if(interfaces_hooks == NULL){
2606
perror_plus("malloc");
2607
goto end;
2608
}
2609
memcpy(interfaces_hooks, mc.interfaces, mc.interfaces_size);
2610
argz_stringify(interfaces_hooks, mc.interfaces_size, (int)',');
2611
}
2612
run_network_hooks("start", interfaces_hooks != NULL ?
2613
interfaces_hooks : "", delay);
2017
ret_errno = argz_append(&interfaces_hooks, &interfaces_hooks_size,
2018
interfaces, interfaces_size);
2019
if(ret_errno != 0){
2020
errno = ret_errno;
2021
perror_plus("argz_append");
2022
goto end;
2023
}
2024
argz_stringify(interfaces_hooks, interfaces_hooks_size, (int)',');
2025
if(not run_network_hooks("start", interfaces_hooks, delay)){
2026
goto end;
2027
}
2614
2028
}
2615
2029
2616
2030
if(not debug){
2621
2035
from the signal handler */
2622
2036
/* Initialize the pseudo-RNG for Avahi */
2623
2037
srand((unsigned int) time(NULL));
2624
simple_poll = avahi_simple_poll_new();
2625
if(simple_poll == NULL){
2038
mc.simple_poll = avahi_simple_poll_new();
2039
if(mc.simple_poll == NULL){
2626
2040
fprintf_plus(stderr,
2627
2041
"Avahi: Failed to create simple poll object.\n");
2628
2042
exitcode = EX_UNAVAILABLE;
2693
2107
}
2694
2108
2695
2109
/* If no interfaces were specified, make a list */
2696
if(mc.interfaces == NULL){
2697
struct dirent **direntries = NULL;
2110
if(interfaces == NULL){
2111
struct dirent **direntries;
2698
2112
/* Look for any good interfaces */
2699
2113
ret = scandir(sys_class_net, &direntries, good_interface,
2700
2114
alphasort);
2701
2115
if(ret >= 1){
2702
2116
/* Add all found interfaces to interfaces list */
2703
2117
for(int i = 0; i < ret; ++i){
2704
ret_errno = argz_add(&mc.interfaces, &mc.interfaces_size,
2118
ret_errno = argz_add(&interfaces, &interfaces_size,
2705
2119
direntries[i]->d_name);
2706
2120
if(ret_errno != 0){
2707
errno = ret_errno;
2708
2121
perror_plus("argz_add");
2709
free(direntries[i]);
2710
2122
continue;
2711
2123
}
2712
2124
if(debug){
2713
2125
fprintf_plus(stderr, "Will use interface \"%s\"\n",
2714
2126
direntries[i]->d_name);
2715
2127
}
2716
free(direntries[i]);
2717
2128
}
2718
2129
free(direntries);
2719
2130
} else {
2720
if(ret == 0){
2721
free(direntries);
2722
}
2131
free(direntries);
2723
2132
fprintf_plus(stderr, "Could not find a network interface\n");
2724
2133
exitcode = EXIT_FAILURE;
2725
2134
goto end;
2726
2135
}
2727
2136
}
2728
2137
2729
/* Bring up interfaces which are down, and remove any "none"s */
2730
{
2138
/* If we only got one interface, explicitly use only that one */
2139
if(argz_count(interfaces, interfaces_size) == 1){
2140
if(debug){
2141
fprintf_plus(stderr, "Using only interface \"%s\"\n",
2142
interfaces);
2143
}
2144
if_index = (AvahiIfIndex)if_nametoindex(interfaces);
2145
}
2146
2147
/* Bring up interfaces which are down */
2148
if(not (argz_count(interfaces, interfaces_size) == 1
2149
and strcmp(interfaces, "none") == 0)){
2731
2150
char *interface = NULL;
2732
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2151
while((interface = argz_next(interfaces, interfaces_size,
2733
2152
interface))){
2734
/* If interface name is "none", stop bringing up interfaces.
2735
Also remove all instances of "none" from the list */
2736
if(strcmp(interface, "none") == 0){
2737
argz_delete(&mc.interfaces, &mc.interfaces_size,
2738
interface);
2739
interface = NULL;
2740
while((interface = argz_next(mc.interfaces,
2741
mc.interfaces_size, interface))){
2742
if(strcmp(interface, "none") == 0){
2743
argz_delete(&mc.interfaces, &mc.interfaces_size,
2744
interface);
2745
interface = NULL;
2746
}
2747
}
2748
break;
2749
}
2750
2153
bool interface_was_up = interface_is_up(interface);
2751
errno = bring_up_interface(interface, delay);
2154
ret = bring_up_interface(interface, delay);
2752
2155
if(not interface_was_up){
2753
if(errno != 0){
2754
fprintf_plus(stderr, "Failed to bring up interface \"%s\":"
2755
" %s\n", interface, strerror(errno));
2156
if(ret != 0){
2157
errno = ret;
2158
perror_plus("Failed to bring up interface");
2756
2159
} else {
2757
errno = argz_add(&interfaces_to_take_down,
2758
&interfaces_to_take_down_size,
2759
interface);
2760
if(errno != 0){
2761
perror_plus("argz_add");
2762
}
2160
ret_errno = argz_add(&interfaces_to_take_down,
2161
&interfaces_to_take_down_size,
2162
interface);
2763
2163
}
2764
2164
}
2765
2165
}
2166
free(interfaces);
2167
interfaces = NULL;
2168
interfaces_size = 0;
2766
2169
if(debug and (interfaces_to_take_down == NULL)){
2767
2170
fprintf_plus(stderr, "No interfaces were brought up\n");
2768
2171
}
2769
2172
}
2770
2173
2771
/* If we only got one interface, explicitly use only that one */
2772
if(argz_count(mc.interfaces, mc.interfaces_size) == 1){
2773
if(debug){
2774
fprintf_plus(stderr, "Using only interface \"%s\"\n",
2775
mc.interfaces);
2776
}
2777
if_index = (AvahiIfIndex)if_nametoindex(mc.interfaces);
2778
}
2779
2780
2174
if(quit_now){
2781
2175
goto end;
2782
2176
}
2783
2177
2784
ret = init_gnutls_global(pubkey, seckey, dh_params_file, &mc);
2178
ret = init_gnutls_global(pubkey, seckey);
2785
2179
if(ret == -1){
2786
2180
fprintf_plus(stderr, "init_gnutls_global failed\n");
2787
2181
exitcode = EX_UNAVAILABLE;
2794
2188
goto end;
2795
2189
}
2796
2190
2797
/* Try /run/tmp before /tmp */
2798
tempdir = mkdtemp(run_tempdir);
2799
if(tempdir == NULL and errno == ENOENT){
2800
if(debug){
2801
fprintf_plus(stderr, "Tempdir %s did not work, trying %s\n",
2802
run_tempdir, old_tempdir);
2803
}
2804
tempdir = mkdtemp(old_tempdir);
2805
}
2806
if(tempdir == NULL){
2191
if(mkdtemp(tempdir) == NULL){
2807
2192
perror_plus("mkdtemp");
2808
2193
goto end;
2809
2194
}
2195
tempdir_created = true;
2810
2196
2811
2197
if(quit_now){
2812
2198
goto end;
2813
2199
}
2814
2200
2815
if(not init_gpgme(pubkey, seckey, tempdir, &mc)){
2201
if(not init_gpgme(pubkey, seckey, tempdir)){
2816
2202
fprintf_plus(stderr, "init_gpgme failed\n");
2817
2203
exitcode = EX_UNAVAILABLE;
2818
2204
goto end;
2848
2234
exitcode = EX_USAGE;
2849
2235
goto end;
2850
2236
}
2851
2237
2852
2238
if(quit_now){
2853
2239
goto end;
2854
2240
}
2875
2261
}
2876
2262
2877
2263
while(not quit_now){
2878
ret = start_mandos_communication(address, port, if_index, af,
2879
&mc);
2264
ret = start_mandos_communication(address, port, if_index, af);
2880
2265
if(quit_now or ret == 0){
2881
2266
break;
2882
2267
}
2884
2269
fprintf_plus(stderr, "Retrying in %d seconds\n",
2885
2270
(int)retry_interval);
2886
2271
}
2887
sleep((unsigned int)retry_interval);
2272
sleep((int)retry_interval);
2888
2273
}
2889
2274
2890
if(not quit_now){
2275
if (not quit_now){
2891
2276
exitcode = EXIT_SUCCESS;
2892
2277
}
2893
2278
2908
2293
config.publish_domain = 0;
2909
2294
2910
2295
/* Allocate a new server */
2911
mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),
2912
&config, NULL, NULL, &ret);
2296
mc.server = avahi_server_new(avahi_simple_poll_get
2297
(mc.simple_poll), &config, NULL,
2298
NULL, &ret_errno);
2913
2299
2914
2300
/* Free the Avahi configuration data */
2915
2301
avahi_server_config_free(&config);
2918
2304
/* Check if creating the Avahi server object succeeded */
2919
2305
if(mc.server == NULL){
2920
2306
fprintf_plus(stderr, "Failed to create Avahi server: %s\n",
2921
avahi_strerror(ret));
2307
avahi_strerror(ret_errno));
2922
2308
exitcode = EX_UNAVAILABLE;
2923
2309
goto end;
2924
2310
}
2930
2316
/* Create the Avahi service browser */
2931
2317
sb = avahi_s_service_browser_new(mc.server, if_index,
2932
2318
AVAHI_PROTO_UNSPEC, "_mandos._tcp",
2933
NULL, 0, browse_callback,
2934
(void *)&mc);
2319
NULL, 0, browse_callback, NULL);
2935
2320
if(sb == NULL){
2936
2321
fprintf_plus(stderr, "Failed to create service browser: %s\n",
2937
2322
avahi_strerror(avahi_server_errno(mc.server)));
2948
2333
if(debug){
2949
2334
fprintf_plus(stderr, "Starting Avahi loop search\n");
2950
2335
}
2951
2952
ret = avahi_loop_with_timeout(simple_poll,
2953
(int)(retry_interval * 1000), &mc);
2336
2337
ret = avahi_loop_with_timeout(mc.simple_poll,
2338
(int)(retry_interval * 1000));
2954
2339
if(debug){
2955
2340
fprintf_plus(stderr, "avahi_loop_with_timeout exited %s\n",
2956
2341
(ret == 0) ? "successfully" : "with error");
2959
2344
end:
2960
2345
2961
2346
if(debug){
2962
if(signal_received){
2963
fprintf_plus(stderr, "%s exiting due to signal %d: %s\n",
2964
argv[0], signal_received,
2965
strsignal(signal_received));
2966
} else {
2967
fprintf_plus(stderr, "%s exiting\n", argv[0]);
2968
}
2347
fprintf_plus(stderr, "%s exiting\n", argv[0]);
2969
2348
}
2970
2349
2971
2350
/* Cleanup things */
2972
free(mc.interfaces);
2973
2974
2351
if(sb != NULL)
2975
2352
avahi_s_service_browser_free(sb);
2976
2353
2977
2354
if(mc.server != NULL)
2978
2355
avahi_server_free(mc.server);
2979
2356
2980
if(simple_poll != NULL)
2981
avahi_simple_poll_free(simple_poll);
2357
if(mc.simple_poll != NULL)
2358
avahi_simple_poll_free(mc.simple_poll);
2982
2359
2983
2360
if(gnutls_initialized){
2984
2361
gnutls_certificate_free_credentials(mc.cred);
2362
gnutls_global_deinit();
2985
2363
gnutls_dh_params_deinit(mc.dh_params);
2986
2364
}
2987
2365
2995
2373
mc.current_server->prev->next = NULL;
2996
2374
while(mc.current_server != NULL){
2997
2375
server *next = mc.current_server->next;
2998
#ifdef __GNUC__
2999
#pragma GCC diagnostic push
3000
#pragma GCC diagnostic ignored "-Wcast-qual"
3001
#endif
3002
free((char *)(mc.current_server->ip));
3003
#ifdef __GNUC__
3004
#pragma GCC diagnostic pop
3005
#endif
3006
2376
free(mc.current_server);
3007
2377
mc.current_server = next;
3008
2378
}
3009
2379
}
3010
2380
3011
/* Re-raise privileges */
2381
/* Re-raise priviliges */
3012
2382
{
3013
ret = raise_privileges();
3014
if(ret != 0){
3015
errno = ret;
3016
perror_plus("Failed to raise privileges");
3017
} else {
3018
3019
/* Run network hooks */
3020
run_network_hooks("stop", interfaces_hooks != NULL ?
3021
interfaces_hooks : "", delay);
3022
3023
/* Take down the network interfaces which were brought up */
3024
{
3025
char *interface = NULL;
3026
while((interface=argz_next(interfaces_to_take_down,
3027
interfaces_to_take_down_size,
3028
interface))){
3029
ret = take_down_interface(interface);
3030
if(ret != 0){
3031
errno = ret;
3032
perror_plus("Failed to take down interface");
3033
}
3034
}
3035
if(debug and (interfaces_to_take_down == NULL)){
3036
fprintf_plus(stderr, "No interfaces needed to be taken"
3037
" down\n");
3038
}
3039
}
3040
}
3041
3042
ret = lower_privileges_permanently();
3043
if(ret != 0){
3044
errno = ret;
3045
perror_plus("Failed to lower privileges permanently");
3046
}
2383
raise_privileges();
2384
2385
/* Run network hooks */
2386
run_network_hooks("stop", interfaces_hooks, delay);
2387
2388
/* Take down the network interfaces which were brought up */
2389
{
2390
char *interface = NULL;
2391
while((interface=argz_next(interfaces_to_take_down,
2392
interfaces_to_take_down_size,
2393
interface))){
2394
ret_errno = take_down_interface(interface);
2395
if(ret_errno != 0){
2396
errno = ret_errno;
2397
perror_plus("Failed to take down interface");
2398
}
2399
}
2400
if(debug and (interfaces_to_take_down == NULL)){
2401
fprintf_plus(stderr, "No interfaces needed to be taken"
2402
" down\n");
2403
}
2404
}
2405
2406
lower_privileges_permanently();
3047
2407
}
3048
2408
3049
2409
free(interfaces_to_take_down);
3050
2410
free(interfaces_hooks);
3051
2411
3052
void clean_dir_at(int base, const char * const dirname,
3053
uintmax_t level){
2412
/* Removes the GPGME temp directory and all files inside */
2413
if(tempdir_created){
3054
2414
struct dirent **direntries = NULL;
3055
int dret;
3056
int dir_fd = (int)TEMP_FAILURE_RETRY(openat(base, dirname,
3057
O_RDONLY
3058
| O_NOFOLLOW
3059
| O_DIRECTORY
3060
| O_PATH));
3061
if(dir_fd == -1){
3062
perror_plus("open");
3063
}
3064
int numentries = scandirat(dir_fd, ".", &direntries,
3065
notdotentries, alphasort);
3066
if(numentries >= 0){
2415
struct dirent *direntry = NULL;
2416
int numentries = scandir(tempdir, &direntries, notdotentries,
2417
alphasort);
2418
if (numentries > 0){
3067
2419
for(int i = 0; i < numentries; i++){
3068
if(debug){
3069
fprintf_plus(stderr, "Unlinking \"%s/%s\"\n",
3070
dirname, direntries[i]->d_name);
3071
}
3072
dret = unlinkat(dir_fd, direntries[i]->d_name, 0);
3073
if(dret == -1){
3074
if(errno == EISDIR){
3075
dret = unlinkat(dir_fd, direntries[i]->d_name,
3076
AT_REMOVEDIR);
3077
}
3078
if((dret == -1) and (errno == ENOTEMPTY)
3079
and (strcmp(direntries[i]->d_name, "private-keys-v1.d")
3080
== 0) and (level == 0)){
3081
/* Recurse only in this special case */
3082
clean_dir_at(dir_fd, direntries[i]->d_name, level+1);
3083
dret = 0;
3084
}
3085
if(dret == -1){
3086
fprintf_plus(stderr, "unlink(\"%s/%s\"): %s\n", dirname,
3087
direntries[i]->d_name, strerror(errno));
3088
}
3089
}
3090
free(direntries[i]);
3091
}
3092
3093
/* need to clean even if 0 because man page doesn't specify */
3094
free(direntries);
3095
if(numentries == -1){
3096
perror_plus("scandirat");
3097
}
3098
dret = unlinkat(base, dirname, AT_REMOVEDIR);
3099
if(dret == -1 and errno != ENOENT){
3100
perror_plus("rmdir");
3101
}
3102
} else {
3103
perror_plus("scandirat");
3104
}
3105
close(dir_fd);
3106
}
3107
3108
/* Removes the GPGME temp directory and all files inside */
3109
if(tempdir != NULL){
3110
clean_dir_at(-1, tempdir, 0);
2420
direntry = direntries[i];
2421
char *fullname = NULL;
2422
ret = asprintf(&fullname, "%s/%s", tempdir,
2423
direntry->d_name);
2424
if(ret < 0){
2425
perror_plus("asprintf");
2426
continue;
2427
}
2428
ret = remove(fullname);
2429
if(ret == -1){
2430
fprintf_plus(stderr, "remove(\"%s\"): %s\n", fullname,
2431
strerror(errno));
2432
}
2433
free(fullname);
2434
}
2435
}
2436
2437
/* need to clean even if 0 because man page doesn't specify */
2438
free(direntries);
2439
if (numentries == -1){
2440
perror_plus("scandir");
2441
}
2442
ret = rmdir(tempdir);
2443
if(ret == -1 and errno != ENOENT){
2444
perror_plus("rmdir");
2445
}
3111
2446
}
3112
2447
3113
2448
if(quit_now){
Loggerhead is a web-based interface for Breezy
Version: 2.0.2.dev0