26
26
* along with this program. If not, see
27
27
* <http://www.gnu.org/licenses/>.
29
* Contact the authors at <mandos@fukt.bsnet.se>.
29
* Contact the authors at <mandos@recompile.se>.
32
32
/* Needed by GPGME, specifically gpgme_data_seek() */
33
33
#ifndef _LARGEFILE_SOURCE
34
34
#define _LARGEFILE_SOURCE
35
#endif /* not _LARGEFILE_SOURCE */
36
36
#ifndef _FILE_OFFSET_BITS
37
37
#define _FILE_OFFSET_BITS 64
38
#endif /* not _FILE_OFFSET_BITS */
40
40
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
42
42
#include <stdio.h> /* fprintf(), stderr, fwrite(),
43
stdout, ferror(), remove() */
44
#include <stdint.h> /* uint16_t, uint32_t */
44
#include <stdint.h> /* uint16_t, uint32_t, intptr_t */
45
45
#include <stddef.h> /* NULL, size_t, ssize_t */
46
#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
46
#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),
48
48
#include <stdbool.h> /* bool, false, true */
49
#include <string.h> /* memset(), strcmp(), strlen(),
50
strerror(), asprintf(), strcpy() */
49
#include <string.h> /* strcmp(), strlen(), strerror(),
50
asprintf(), strcpy() */
51
51
#include <sys/ioctl.h> /* ioctl */
52
52
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
53
53
sockaddr_in6, PF_INET6,
54
54
SOCK_STREAM, uid_t, gid_t, open(),
56
#include <sys/stat.h> /* open() */
56
#include <sys/stat.h> /* open(), S_ISREG */
57
57
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
58
inet_pton(), connect() */
59
#include <fcntl.h> /* open() */
58
inet_pton(), connect(),
60
#include <fcntl.h> /* open(), unlinkat() */
60
61
#include <dirent.h> /* opendir(), struct dirent, readdir()
62
63
#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,
64
#include <assert.h> /* assert() */
65
#include <errno.h> /* perror(), errno */
66
#include <time.h> /* nanosleep(), time() */
65
#include <errno.h> /* perror(), errno,
66
program_invocation_short_name */
67
#include <time.h> /* nanosleep(), time(), sleep() */
67
68
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
68
69
SIOCSIFFLAGS, if_indextoname(),
69
70
if_nametoindex(), IF_NAMESIZE */
120
133
#define PATHDIR "/conf/conf.d/mandos"
121
134
#define SECKEY "seckey.txt"
122
135
#define PUBKEY "pubkey.txt"
136
#define HOOKDIR "/lib/mandos/network-hooks.d"
124
138
bool debug = false;
125
139
static const char mandos_protocol_version[] = "1";
126
140
const char *argp_program_version = "mandos-client " VERSION;
127
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
141
const char *argp_program_bug_address = "<mandos@recompile.se>";
142
static const char sys_class_net[] = "/sys/class/net";
143
char *connect_to = NULL;
144
const char *hookdir = HOOKDIR;
149
/* Doubly linked list that need to be circularly linked when used */
150
typedef struct server{
153
AvahiIfIndex if_index;
155
struct timespec last_seen;
129
160
/* Used for passing in values through the Avahi callback functions */
131
AvahiSimplePoll *simple_poll;
132
162
AvahiServer *server;
133
163
gnutls_certificate_credentials_t cred;
134
164
unsigned int dh_bits;
135
165
gnutls_dh_params_t dh_params;
136
166
const char *priority;
168
server *current_server;
170
size_t interfaces_size;
138
171
} 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" };
173
/* global so signal handler can reach it*/
174
AvahiSimplePoll *simple_poll;
176
sig_atomic_t quit_now = 0;
177
int signal_received = 0;
179
/* Function to use when printing errors */
180
void perror_plus(const char *print_text){
182
fprintf(stderr, "Mandos plugin %s: ",
183
program_invocation_short_name);
188
__attribute__((format (gnu_printf, 2, 3), nonnull))
189
int fprintf_plus(FILE *stream, const char *format, ...){
191
va_start (ap, format);
193
TEMP_FAILURE_RETRY(fprintf(stream, "Mandos plugin %s: ",
194
program_invocation_short_name));
195
return (int)TEMP_FAILURE_RETRY(vfprintf(stream, format, ap));
146
199
* Make additional room in "buffer" for at least BUFFER_SIZE more
147
200
* bytes. "buffer_capacity" is how much is currently allocated,
148
201
* "buffer_length" is how much is already used.
203
__attribute__((nonnull, warn_unused_result))
150
204
size_t incbuffer(char **buffer, size_t buffer_length,
151
size_t buffer_capacity){
205
size_t buffer_capacity){
152
206
if(buffer_length + BUFFER_SIZE > buffer_capacity){
153
*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
207
char *new_buf = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
209
int old_errno = errno;
157
216
buffer_capacity += BUFFER_SIZE;
159
218
return buffer_capacity;
221
/* Add server to set of servers to retry periodically */
222
__attribute__((nonnull, warn_unused_result))
223
bool add_server(const char *ip, in_port_t port, AvahiIfIndex if_index,
224
int af, server **current_server){
226
server *new_server = malloc(sizeof(server));
227
if(new_server == NULL){
228
perror_plus("malloc");
231
*new_server = (server){ .ip = strdup(ip),
233
.if_index = if_index,
235
if(new_server->ip == NULL){
236
perror_plus("strdup");
240
ret = clock_gettime(CLOCK_MONOTONIC, &(new_server->last_seen));
242
perror_plus("clock_gettime");
244
#pragma GCC diagnostic push
245
#pragma GCC diagnostic ignored "-Wcast-qual"
247
free((char *)(new_server->ip));
249
#pragma GCC diagnostic pop
254
/* Special case of first server */
255
if(*current_server == NULL){
256
new_server->next = new_server;
257
new_server->prev = new_server;
258
*current_server = new_server;
260
/* Place the new server last in the list */
261
new_server->next = *current_server;
262
new_server->prev = (*current_server)->prev;
263
new_server->prev->next = new_server;
264
(*current_server)->prev = new_server;
163
270
* Initialize GPGME.
165
static bool init_gpgme(const char *seckey,
166
const char *pubkey, const char *tempdir){
272
__attribute__((nonnull, warn_unused_result))
273
static bool init_gpgme(const char * const seckey,
274
const char * const pubkey,
275
const char * const tempdir,
167
277
gpgme_error_t rc;
168
278
gpgme_engine_info_t engine_info;
172
281
* Helper function to insert pub and seckey to the engine keyring.
174
bool import_key(const char *filename){
283
bool import_key(const char * const filename){
177
286
gpgme_data_t pgp_data;
179
288
fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
185
294
rc = gpgme_data_new_from_fd(&pgp_data, fd);
186
295
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));
296
fprintf_plus(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
297
gpgme_strsource(rc), gpgme_strerror(rc));
192
rc = gpgme_op_import(mc.ctx, pgp_data);
301
rc = gpgme_op_import(mc->ctx, pgp_data);
193
302
if(rc != GPG_ERR_NO_ERROR){
194
fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
195
gpgme_strsource(rc), gpgme_strerror(rc));
303
fprintf_plus(stderr, "bad gpgme_op_import: %s: %s\n",
304
gpgme_strsource(rc), gpgme_strerror(rc));
199
ret = (int)TEMP_FAILURE_RETRY(close(fd));
310
perror_plus("close");
203
312
gpgme_data_release(pgp_data);
208
fprintf(stderr, "Initializing GPGME\n");
317
fprintf_plus(stderr, "Initializing GPGME\n");
212
321
gpgme_check_version(NULL);
213
322
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
214
323
if(rc != GPG_ERR_NO_ERROR){
215
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
216
gpgme_strsource(rc), gpgme_strerror(rc));
324
fprintf_plus(stderr, "bad gpgme_engine_check_version: %s: %s\n",
325
gpgme_strsource(rc), gpgme_strerror(rc));
220
/* Set GPGME home directory for the OpenPGP engine only */
329
/* Set GPGME home directory for the OpenPGP engine only */
221
330
rc = gpgme_get_engine_info(&engine_info);
222
331
if(rc != GPG_ERR_NO_ERROR){
223
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
224
gpgme_strsource(rc), gpgme_strerror(rc));
332
fprintf_plus(stderr, "bad gpgme_get_engine_info: %s: %s\n",
333
gpgme_strsource(rc), gpgme_strerror(rc));
227
336
while(engine_info != NULL){
266
379
ssize_t plaintext_length = 0;
269
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
382
fprintf_plus(stderr, "Trying to decrypt OpenPGP data\n");
272
385
/* Create new GPGME data buffer from memory cryptotext */
273
386
rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,
275
388
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));
389
fprintf_plus(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
390
gpgme_strsource(rc), gpgme_strerror(rc));
281
394
/* Create new empty GPGME data buffer for the plaintext */
282
395
rc = gpgme_data_new(&dh_plain);
283
396
if(rc != GPG_ERR_NO_ERROR){
284
fprintf(stderr, "bad gpgme_data_new: %s: %s\n",
285
gpgme_strsource(rc), gpgme_strerror(rc));
397
fprintf_plus(stderr, "Mandos plugin mandos-client: "
398
"bad gpgme_data_new: %s: %s\n",
399
gpgme_strsource(rc), gpgme_strerror(rc));
286
400
gpgme_data_release(dh_crypto);
290
404
/* Decrypt data from the cryptotext data buffer to the plaintext
292
rc = gpgme_op_decrypt(mc.ctx, dh_crypto, dh_plain);
406
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
293
407
if(rc != GPG_ERR_NO_ERROR){
294
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
295
gpgme_strsource(rc), gpgme_strerror(rc));
408
fprintf_plus(stderr, "bad gpgme_op_decrypt: %s: %s\n",
409
gpgme_strsource(rc), gpgme_strerror(rc));
296
410
plaintext_length = -1;
298
412
gpgme_decrypt_result_t result;
299
result = gpgme_op_decrypt_result(mc.ctx);
413
result = gpgme_op_decrypt_result(mc->ctx);
300
414
if(result == NULL){
301
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
415
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);
417
fprintf_plus(stderr, "Unsupported algorithm: %s\n",
418
result->unsupported_algorithm);
419
fprintf_plus(stderr, "Wrong key usage: %u\n",
420
result->wrong_key_usage);
307
421
if(result->file_name != NULL){
308
fprintf(stderr, "File name: %s\n", result->file_name);
422
fprintf_plus(stderr, "File name: %s\n", result->file_name);
310
424
gpgme_recipient_t recipient;
311
425
recipient = result->recipients;
312
426
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
427
fprintf_plus(stderr, "Public key algorithm: %s\n",
428
gpgme_pubkey_algo_name
429
(recipient->pubkey_algo));
430
fprintf_plus(stderr, "Key ID: %s\n", recipient->keyid);
431
fprintf_plus(stderr, "Secret key available: %s\n",
432
recipient->status == GPG_ERR_NO_SECKEY
319
434
recipient = recipient->next;
418
543
/* OpenPGP credentials */
419
gnutls_certificate_allocate_credentials(&mc.cred);
544
ret = gnutls_certificate_allocate_credentials(&mc->cred);
420
545
if(ret != GNUTLS_E_SUCCESS){
421
fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning
425
safer_gnutls_strerror(ret));
546
fprintf_plus(stderr, "GnuTLS memory error: %s\n",
547
safer_gnutls_strerror(ret));
426
548
gnutls_global_deinit();
431
fprintf(stderr, "Attempting to use OpenPGP public key %s and"
432
" secret key %s as GnuTLS credentials\n", pubkeyfilename,
553
fprintf_plus(stderr, "Attempting to use OpenPGP public key %s and"
554
" secret key %s as GnuTLS credentials\n",
436
559
ret = gnutls_certificate_set_openpgp_key_file
437
(mc.cred, pubkeyfilename, seckeyfilename,
560
(mc->cred, pubkeyfilename, seckeyfilename,
438
561
GNUTLS_OPENPGP_FMT_BASE64);
439
562
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));
564
"Error[%d] while reading the OpenPGP key pair ('%s',"
565
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
566
fprintf_plus(stderr, "The GnuTLS error is: %s\n",
567
safer_gnutls_strerror(ret));
448
571
/* 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);
572
ret = gnutls_dh_params_init(&mc->dh_params);
573
if(ret != GNUTLS_E_SUCCESS){
574
fprintf_plus(stderr, "Error in GnuTLS DH parameter"
575
" initialization: %s\n",
576
safer_gnutls_strerror(ret));
579
/* If a Diffie-Hellman parameters file was given, try to use it */
580
if(dhparamsfilename != NULL){
581
gnutls_datum_t params = { .data = NULL, .size = 0 };
583
int dhpfile = open(dhparamsfilename, O_RDONLY);
586
dhparamsfilename = NULL;
589
size_t params_capacity = 0;
591
params_capacity = incbuffer((char **)¶ms.data,
593
(size_t)params_capacity);
594
if(params_capacity == 0){
595
perror_plus("incbuffer");
598
dhparamsfilename = NULL;
601
ssize_t bytes_read = read(dhpfile,
602
params.data + params.size,
608
/* check bytes_read for failure */
613
dhparamsfilename = NULL;
616
params.size += (unsigned int)bytes_read;
618
if(params.data == NULL){
619
dhparamsfilename = NULL;
621
if(dhparamsfilename == NULL){
624
ret = gnutls_dh_params_import_pkcs3(mc->dh_params, ¶ms,
625
GNUTLS_X509_FMT_PEM);
626
if(ret != GNUTLS_E_SUCCESS){
627
fprintf_plus(stderr, "Failed to parse DH parameters in file"
628
" \"%s\": %s\n", dhparamsfilename,
629
safer_gnutls_strerror(ret));
630
dhparamsfilename = NULL;
634
if(dhparamsfilename == NULL){
635
if(mc->dh_bits == 0){
636
/* Find out the optimal number of DH bits */
637
/* Try to read the private key file */
638
gnutls_datum_t buffer = { .data = NULL, .size = 0 };
640
int secfile = open(seckeyfilename, O_RDONLY);
645
size_t buffer_capacity = 0;
647
buffer_capacity = incbuffer((char **)&buffer.data,
649
(size_t)buffer_capacity);
650
if(buffer_capacity == 0){
651
perror_plus("incbuffer");
656
ssize_t bytes_read = read(secfile,
657
buffer.data + buffer.size,
663
/* check bytes_read for failure */
670
buffer.size += (unsigned int)bytes_read;
674
/* If successful, use buffer to parse private key */
675
gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;
676
if(buffer.data != NULL){
678
gnutls_openpgp_privkey_t privkey = NULL;
679
ret = gnutls_openpgp_privkey_init(&privkey);
680
if(ret != GNUTLS_E_SUCCESS){
681
fprintf_plus(stderr, "Error initializing OpenPGP key"
683
safer_gnutls_strerror(ret));
687
ret = gnutls_openpgp_privkey_import
688
(privkey, &buffer, GNUTLS_OPENPGP_FMT_BASE64, "", 0);
689
if(ret != GNUTLS_E_SUCCESS){
690
fprintf_plus(stderr, "Error importing OpenPGP key : %s",
691
safer_gnutls_strerror(ret));
697
/* Use private key to suggest an appropriate
699
sec_param = gnutls_openpgp_privkey_sec_param(privkey);
700
gnutls_openpgp_privkey_deinit(privkey);
702
fprintf_plus(stderr, "This OpenPGP key implies using"
703
" a GnuTLS security parameter \"%s\".\n",
704
safe_string(gnutls_sec_param_get_name
710
if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){
711
/* Err on the side of caution */
712
sec_param = GNUTLS_SEC_PARAM_ULTRA;
714
fprintf_plus(stderr, "Falling back to security parameter"
716
safe_string(gnutls_sec_param_get_name
721
uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);
725
fprintf_plus(stderr, "A \"%s\" GnuTLS security parameter"
726
" implies %u DH bits; using that.\n",
727
safe_string(gnutls_sec_param_get_name
732
fprintf_plus(stderr, "Failed to get implied number of DH"
733
" bits for security parameter \"%s\"): %s\n",
734
safe_string(gnutls_sec_param_get_name
736
safer_gnutls_strerror(ret));
740
fprintf_plus(stderr, "DH bits explicitly set to %u\n",
743
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
744
if(ret != GNUTLS_E_SUCCESS){
745
fprintf_plus(stderr, "Error in GnuTLS prime generation (%u"
746
" bits): %s\n", mc->dh_bits,
747
safer_gnutls_strerror(ret));
751
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
468
gnutls_certificate_free_credentials(mc.cred);
757
gnutls_certificate_free_credentials(mc->cred);
469
758
gnutls_global_deinit();
470
gnutls_dh_params_deinit(mc.dh_params);
759
gnutls_dh_params_deinit(mc->dh_params);
474
static int init_gnutls_session(gnutls_session_t *session){
763
__attribute__((nonnull, warn_unused_result))
764
static int init_gnutls_session(gnutls_session_t *session,
476
767
/* GnuTLS session creation */
478
769
ret = gnutls_init(session, GNUTLS_SERVER);
479
773
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
480
774
if(ret != GNUTLS_E_SUCCESS){
481
fprintf(stderr, "Error in GnuTLS session initialization: %s\n",
482
safer_gnutls_strerror(ret));
776
"Error in GnuTLS session initialization: %s\n",
777
safer_gnutls_strerror(ret));
488
ret = gnutls_priority_set_direct(*session, mc.priority, &err);
783
ret = gnutls_priority_set_direct(*session, mc->priority, &err);
785
gnutls_deinit(*session);
489
788
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
490
789
if(ret != GNUTLS_E_SUCCESS){
491
fprintf(stderr, "Syntax error at: %s\n", err);
492
fprintf(stderr, "GnuTLS error: %s\n",
493
safer_gnutls_strerror(ret));
790
fprintf_plus(stderr, "Syntax error at: %s\n", err);
791
fprintf_plus(stderr, "GnuTLS error: %s\n",
792
safer_gnutls_strerror(ret));
494
793
gnutls_deinit(*session);
519
820
static void empty_log(__attribute__((unused)) AvahiLogLevel level,
520
821
__attribute__((unused)) const char *txt){}
522
sig_atomic_t quit_now = 0;
523
int signal_received = 0;
823
/* Set effective uid to 0, return errno */
824
__attribute__((warn_unused_result))
825
error_t raise_privileges(void){
826
error_t old_errno = errno;
827
error_t ret_errno = 0;
828
if(seteuid(0) == -1){
835
/* Set effective and real user ID to 0. Return errno. */
836
__attribute__((warn_unused_result))
837
error_t raise_privileges_permanently(void){
838
error_t old_errno = errno;
839
error_t ret_errno = raise_privileges();
851
/* Set effective user ID to unprivileged saved user ID */
852
__attribute__((warn_unused_result))
853
error_t lower_privileges(void){
854
error_t old_errno = errno;
855
error_t ret_errno = 0;
856
if(seteuid(uid) == -1){
863
/* Lower privileges permanently */
864
__attribute__((warn_unused_result))
865
error_t lower_privileges_permanently(void){
866
error_t old_errno = errno;
867
error_t ret_errno = 0;
868
if(setuid(uid) == -1){
875
/* Helper function to add_local_route() and delete_local_route() */
876
__attribute__((nonnull, warn_unused_result))
877
static bool add_delete_local_route(const bool add,
879
AvahiIfIndex if_index){
881
char helper[] = "mandos-client-iprouteadddel";
882
char add_arg[] = "add";
883
char delete_arg[] = "delete";
884
char debug_flag[] = "--debug";
885
char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");
886
if(pluginhelperdir == NULL){
888
fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"
889
" variable not set; cannot run helper\n");
894
char interface[IF_NAMESIZE];
895
if(if_indextoname((unsigned int)if_index, interface) == NULL){
896
perror_plus("if_indextoname");
900
int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));
902
perror_plus("open(\"/dev/null\", O_RDONLY)");
908
/* Raise privileges */
909
errno = raise_privileges_permanently();
911
perror_plus("Failed to raise privileges");
912
/* _exit(EX_NOPERM); */
918
perror_plus("setgid");
921
/* Reset supplementary groups */
923
ret = setgroups(0, NULL);
925
perror_plus("setgroups");
929
ret = dup2(devnull, STDIN_FILENO);
931
perror_plus("dup2(devnull, STDIN_FILENO)");
934
ret = close(devnull);
936
perror_plus("close");
939
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
941
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
944
int helperdir_fd = (int)TEMP_FAILURE_RETRY(open(pluginhelperdir,
949
if(helperdir_fd == -1){
951
_exit(EX_UNAVAILABLE);
953
int helper_fd = (int)TEMP_FAILURE_RETRY(openat(helperdir_fd,
956
perror_plus("openat");
958
_exit(EX_UNAVAILABLE);
962
#pragma GCC diagnostic push
963
#pragma GCC diagnostic ignored "-Wcast-qual"
965
if(fexecve(helper_fd, (char *const [])
966
{ helper, add ? add_arg : delete_arg, (char *)address,
967
interface, debug ? debug_flag : NULL, NULL },
970
#pragma GCC diagnostic pop
972
perror_plus("fexecve");
984
pret = waitpid(pid, &status, 0);
985
if(pret == -1 and errno == EINTR and quit_now){
986
int errno_raising = 0;
987
if((errno = raise_privileges()) != 0){
988
errno_raising = errno;
989
perror_plus("Failed to raise privileges in order to"
990
" kill helper program");
992
if(kill(pid, SIGTERM) == -1){
995
if((errno_raising == 0) and (errno = lower_privileges()) != 0){
996
perror_plus("Failed to lower privileges after killing"
1001
} while(pret == -1 and errno == EINTR);
1003
perror_plus("waitpid");
1006
if(WIFEXITED(status)){
1007
if(WEXITSTATUS(status) != 0){
1008
fprintf_plus(stderr, "Error: iprouteadddel exited"
1009
" with status %d\n", WEXITSTATUS(status));
1014
if(WIFSIGNALED(status)){
1015
fprintf_plus(stderr, "Error: iprouteadddel died by"
1016
" signal %d\n", WTERMSIG(status));
1019
fprintf_plus(stderr, "Error: iprouteadddel crashed\n");
1023
__attribute__((nonnull, warn_unused_result))
1024
static bool add_local_route(const char *address,
1025
AvahiIfIndex if_index){
1027
fprintf_plus(stderr, "Adding route to %s\n", address);
1029
return add_delete_local_route(true, address, if_index);
1032
__attribute__((nonnull, warn_unused_result))
1033
static bool delete_local_route(const char *address,
1034
AvahiIfIndex if_index){
1036
fprintf_plus(stderr, "Removing route to %s\n", address);
1038
return add_delete_local_route(false, address, if_index);
525
1041
/* Called when a Mandos server is found */
526
static int start_mandos_communication(const char *ip, uint16_t port,
1042
__attribute__((nonnull, warn_unused_result))
1043
static int start_mandos_communication(const char *ip, in_port_t port,
527
1044
AvahiIfIndex if_index,
1045
int af, mandos_context *mc){
529
1046
int ret, tcp_sd = -1;
532
struct sockaddr_in in;
533
struct sockaddr_in6 in6;
1048
struct sockaddr_storage to;
535
1049
char *buffer = NULL;
536
char *decrypted_buffer;
1050
char *decrypted_buffer = NULL;
537
1051
size_t buffer_length = 0;
538
1052
size_t buffer_capacity = 0;
541
1055
gnutls_session_t session;
542
1056
int pf; /* Protocol family */
1057
bool route_added = false;
556
fprintf(stderr, "Bad address family: %d\n", af);
1074
fprintf_plus(stderr, "Bad address family: %d\n", af);
560
ret = init_gnutls_session(&session);
1079
/* If the interface is specified and we have a list of interfaces */
1080
if(if_index != AVAHI_IF_UNSPEC and mc->interfaces != NULL){
1081
/* Check if the interface is one of the interfaces we are using */
1084
char *interface = NULL;
1085
while((interface=argz_next(mc->interfaces, mc->interfaces_size,
1087
if(if_nametoindex(interface) == (unsigned int)if_index){
1094
/* This interface does not match any in the list, so we don't
1095
connect to the server */
1097
char interface[IF_NAMESIZE];
1098
if(if_indextoname((unsigned int)if_index, interface) == NULL){
1099
perror_plus("if_indextoname");
1101
fprintf_plus(stderr, "Skipping server on non-used interface"
1103
if_indextoname((unsigned int)if_index,
1111
ret = init_gnutls_session(&session, mc);
566
fprintf(stderr, "Setting up a TCP connection to %s, port %" PRIu16
1117
fprintf_plus(stderr, "Setting up a TCP connection to %s, port %"
1118
PRIuMAX "\n", ip, (uintmax_t)port);
570
tcp_sd = socket(pf, SOCK_STREAM, 0);
1121
tcp_sd = socket(pf, SOCK_STREAM | SOCK_CLOEXEC, 0);
1124
perror_plus("socket");
574
1126
goto mandos_end;
578
1131
goto mandos_end;
581
memset(&to, 0, sizeof(to));
582
1134
if(af == AF_INET6){
583
to.in6.sin6_family = (sa_family_t)af;
584
ret = inet_pton(af, ip, &to.in6.sin6_addr);
1135
struct sockaddr_in6 *to6 = (struct sockaddr_in6 *)&to;
1136
*to6 = (struct sockaddr_in6){ .sin6_family = (sa_family_t)af };
1137
ret = inet_pton(af, ip, &to6->sin6_addr);
585
1138
} else { /* IPv4 */
586
to.in.sin_family = (sa_family_t)af;
587
ret = inet_pton(af, ip, &to.in.sin_addr);
1139
struct sockaddr_in *to4 = (struct sockaddr_in *)&to;
1140
*to4 = (struct sockaddr_in){ .sin_family = (sa_family_t)af };
1141
ret = inet_pton(af, ip, &to4->sin_addr);
1145
perror_plus("inet_pton");
592
1147
goto mandos_end;
595
fprintf(stderr, "Bad address: %s\n", ip);
1151
fprintf_plus(stderr, "Bad address: %s\n", ip);
597
1153
goto mandos_end;
599
1155
if(af == AF_INET6){
600
to.in6.sin6_port = htons(port); /* Spurious warnings from
602
-Wunreachable-code */
604
if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */
605
(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower and
1156
((struct sockaddr_in6 *)&to)->sin6_port = htons(port);
1157
if(IN6_IS_ADDR_LINKLOCAL
1158
(&((struct sockaddr_in6 *)&to)->sin6_addr)){
607
1159
if(if_index == AVAHI_IF_UNSPEC){
608
fprintf(stderr, "An IPv6 link-local address is incomplete"
609
" without a network interface\n");
1160
fprintf_plus(stderr, "An IPv6 link-local address is"
1161
" incomplete without a network interface\n");
611
1163
goto mandos_end;
613
1165
/* Set the network interface number as scope */
614
to.in6.sin6_scope_id = (uint32_t)if_index;
1166
((struct sockaddr_in6 *)&to)->sin6_scope_id = (uint32_t)if_index;
617
to.in.sin_port = htons(port); /* Spurious warnings from
619
-Wunreachable-code */
1169
((struct sockaddr_in *)&to)->sin_port = htons(port);
623
1174
goto mandos_end;
627
1178
if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){
628
1179
char interface[IF_NAMESIZE];
629
1180
if(if_indextoname((unsigned int)if_index, interface) == NULL){
630
perror("if_indextoname");
1181
perror_plus("if_indextoname");
632
fprintf(stderr, "Connection to: %s%%%s, port %" PRIu16 "\n",
633
ip, interface, port);
1183
fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIuMAX
1184
"\n", ip, interface, (uintmax_t)port);
636
fprintf(stderr, "Connection to: %s, port %" PRIu16 "\n", ip,
1187
fprintf_plus(stderr, "Connection to: %s, port %" PRIuMAX "\n",
1188
ip, (uintmax_t)port);
639
1190
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
640
1191
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
643
pcret = inet_ntop(af, &(to.in6.sin6_addr), addrstr,
646
pcret = inet_ntop(af, &(to.in.sin_addr), addrstr,
652
if(strcmp(addrstr, ip) != 0){
653
fprintf(stderr, "Canonical address form: %s\n", addrstr);
663
ret = connect(tcp_sd, &to.in6, sizeof(to));
665
ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */
1193
ret = getnameinfo((struct sockaddr *)&to,
1194
sizeof(struct sockaddr_in6),
1195
addrstr, sizeof(addrstr), NULL, 0,
1198
ret = getnameinfo((struct sockaddr *)&to,
1199
sizeof(struct sockaddr_in),
1200
addrstr, sizeof(addrstr), NULL, 0,
1203
if(ret == EAI_SYSTEM){
1204
perror_plus("getnameinfo");
1205
} else if(ret != 0) {
1206
fprintf_plus(stderr, "getnameinfo: %s", gai_strerror(ret));
1207
} else if(strcmp(addrstr, ip) != 0){
1208
fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);
1219
ret = connect(tcp_sd, (struct sockaddr *)&to,
1220
sizeof(struct sockaddr_in6));
1222
ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */
1223
sizeof(struct sockaddr_in));
1226
if(((errno == ENETUNREACH) or (errno == EHOSTUNREACH))
1227
and if_index != AVAHI_IF_UNSPEC
1228
and connect_to == NULL
1229
and not route_added and
1230
((af == AF_INET6 and not
1231
IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)
1233
or (af == AF_INET and
1234
/* Not a a IPv4LL address */
1235
(ntohl(((struct sockaddr_in *)&to)->sin_addr.s_addr)
1236
& 0xFFFF0000L) != 0xA9FE0000L))){
1237
/* Work around Avahi bug - Avahi does not announce link-local
1238
addresses if it has a global address, so local hosts with
1239
*only* a link-local address (e.g. Mandos clients) cannot
1240
connect to a Mandos server announced by Avahi on a server
1241
host with a global address. Work around this by retrying
1242
with an explicit route added with the server's address.
1244
Avahi bug reference:
1245
http://lists.freedesktop.org/archives/avahi/2010-February/001833.html
1246
https://bugs.debian.org/587961
1249
fprintf_plus(stderr, "Mandos server unreachable, trying"
1253
route_added = add_local_route(ip, if_index);
1259
if(errno != ECONNREFUSED or debug){
1261
perror_plus("connect");
677
1274
const char *out = mandos_protocol_version;
971
1619
signal_received = sig;
972
1620
int old_errno = errno;
973
if(mc.simple_poll != NULL){
974
avahi_simple_poll_quit(mc.simple_poll);
1621
/* set main loop to exit */
1622
if(simple_poll != NULL){
1623
avahi_simple_poll_quit(simple_poll);
1628
__attribute__((nonnull, warn_unused_result))
1629
bool get_flags(const char *ifname, struct ifreq *ifr){
1633
int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1636
perror_plus("socket");
1640
strcpy(ifr->ifr_name, ifname);
1641
ret = ioctl(s, SIOCGIFFLAGS, ifr);
1645
perror_plus("ioctl SIOCGIFFLAGS");
1653
__attribute__((nonnull, warn_unused_result))
1654
bool good_flags(const char *ifname, const struct ifreq *ifr){
1656
/* Reject the loopback device */
1657
if(ifr->ifr_flags & IFF_LOOPBACK){
1659
fprintf_plus(stderr, "Rejecting loopback interface \"%s\"\n",
1664
/* Accept point-to-point devices only if connect_to is specified */
1665
if(connect_to != NULL and (ifr->ifr_flags & IFF_POINTOPOINT)){
1667
fprintf_plus(stderr, "Accepting point-to-point interface"
1668
" \"%s\"\n", ifname);
1672
/* Otherwise, reject non-broadcast-capable devices */
1673
if(not (ifr->ifr_flags & IFF_BROADCAST)){
1675
fprintf_plus(stderr, "Rejecting non-broadcast interface"
1676
" \"%s\"\n", ifname);
1680
/* Reject non-ARP interfaces (including dummy interfaces) */
1681
if(ifr->ifr_flags & IFF_NOARP){
1683
fprintf_plus(stderr, "Rejecting non-ARP interface \"%s\"\n",
1689
/* Accept this device */
1691
fprintf_plus(stderr, "Interface \"%s\" is good\n", ifname);
1697
* This function determines if a directory entry in /sys/class/net
1698
* corresponds to an acceptable network device.
1699
* (This function is passed to scandir(3) as a filter function.)
1701
__attribute__((nonnull, warn_unused_result))
1702
int good_interface(const struct dirent *if_entry){
1703
if(if_entry->d_name[0] == '.'){
1708
if(not get_flags(if_entry->d_name, &ifr)){
1710
fprintf_plus(stderr, "Failed to get flags for interface "
1711
"\"%s\"\n", if_entry->d_name);
1716
if(not good_flags(if_entry->d_name, &ifr)){
1723
* This function determines if a network interface is up.
1725
__attribute__((nonnull, warn_unused_result))
1726
bool interface_is_up(const char *interface){
1728
if(not get_flags(interface, &ifr)){
1730
fprintf_plus(stderr, "Failed to get flags for interface "
1731
"\"%s\"\n", interface);
1736
return (bool)(ifr.ifr_flags & IFF_UP);
1740
* This function determines if a network interface is running
1742
__attribute__((nonnull, warn_unused_result))
1743
bool interface_is_running(const char *interface){
1745
if(not get_flags(interface, &ifr)){
1747
fprintf_plus(stderr, "Failed to get flags for interface "
1748
"\"%s\"\n", interface);
1753
return (bool)(ifr.ifr_flags & IFF_RUNNING);
1756
__attribute__((nonnull, pure, warn_unused_result))
1757
int notdotentries(const struct dirent *direntry){
1758
/* Skip "." and ".." */
1759
if(direntry->d_name[0] == '.'
1760
and (direntry->d_name[1] == '\0'
1761
or (direntry->d_name[1] == '.'
1762
and direntry->d_name[2] == '\0'))){
1768
/* Is this directory entry a runnable program? */
1769
__attribute__((nonnull, warn_unused_result))
1770
int runnable_hook(const struct dirent *direntry){
1775
if((direntry->d_name)[0] == '\0'){
1780
sret = strspn(direntry->d_name, "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
1781
"abcdefghijklmnopqrstuvwxyz"
1784
if((direntry->d_name)[sret] != '\0'){
1785
/* Contains non-allowed characters */
1787
fprintf_plus(stderr, "Ignoring hook \"%s\" with bad name\n",
1793
ret = fstatat(hookdir_fd, direntry->d_name, &st, 0);
1796
perror_plus("Could not stat hook");
1800
if(not (S_ISREG(st.st_mode))){
1801
/* Not a regular file */
1803
fprintf_plus(stderr, "Ignoring hook \"%s\" - not a file\n",
1808
if(not (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))){
1809
/* Not executable */
1811
fprintf_plus(stderr, "Ignoring hook \"%s\" - not executable\n",
1817
fprintf_plus(stderr, "Hook \"%s\" is acceptable\n",
1823
__attribute__((nonnull, warn_unused_result))
1824
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,
1825
mandos_context *mc){
1827
struct timespec now;
1828
struct timespec waited_time;
1829
intmax_t block_time;
1832
if(mc->current_server == NULL){
1834
fprintf_plus(stderr, "Wait until first server is found."
1837
ret = avahi_simple_poll_iterate(s, -1);
1840
fprintf_plus(stderr, "Check current_server if we should run"
1843
/* the current time */
1844
ret = clock_gettime(CLOCK_MONOTONIC, &now);
1846
perror_plus("clock_gettime");
1849
/* Calculating in ms how long time between now and server
1850
who we visted longest time ago. Now - last seen. */
1851
waited_time.tv_sec = (now.tv_sec
1852
- mc->current_server->last_seen.tv_sec);
1853
waited_time.tv_nsec = (now.tv_nsec
1854
- mc->current_server->last_seen.tv_nsec);
1855
/* total time is 10s/10,000ms.
1856
Converting to s from ms by dividing by 1,000,
1857
and ns to ms by dividing by 1,000,000. */
1858
block_time = ((retry_interval
1859
- ((intmax_t)waited_time.tv_sec * 1000))
1860
- ((intmax_t)waited_time.tv_nsec / 1000000));
1863
fprintf_plus(stderr, "Blocking for %" PRIdMAX " ms\n",
1867
if(block_time <= 0){
1868
ret = start_mandos_communication(mc->current_server->ip,
1869
mc->current_server->port,
1870
mc->current_server->if_index,
1871
mc->current_server->af, mc);
1873
avahi_simple_poll_quit(s);
1876
ret = clock_gettime(CLOCK_MONOTONIC,
1877
&mc->current_server->last_seen);
1879
perror_plus("clock_gettime");
1882
mc->current_server = mc->current_server->next;
1883
block_time = 0; /* Call avahi to find new Mandos
1884
servers, but don't block */
1887
ret = avahi_simple_poll_iterate(s, (int)block_time);
1890
if(ret > 0 or errno != EINTR){
1891
return (ret != 1) ? ret : 0;
1897
__attribute__((nonnull))
1898
void run_network_hooks(const char *mode, const char *interface,
1900
struct dirent **direntries = NULL;
1901
if(hookdir_fd == -1){
1902
hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH
1904
if(hookdir_fd == -1){
1905
if(errno == ENOENT){
1907
fprintf_plus(stderr, "Network hook directory \"%s\" not"
1908
" found\n", hookdir);
1911
perror_plus("open");
1917
#if __GLIBC_PREREQ(2, 15)
1918
int numhooks = scandirat(hookdir_fd, ".", &direntries,
1919
runnable_hook, alphasort);
1920
#else /* not __GLIBC_PREREQ(2, 15) */
1921
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1923
#endif /* not __GLIBC_PREREQ(2, 15) */
1924
#else /* not __GLIBC__ */
1925
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1927
#endif /* not __GLIBC__ */
1929
perror_plus("scandir");
1932
struct dirent *direntry;
1934
int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));
1936
perror_plus("open(\"/dev/null\", O_RDONLY)");
1939
for(int i = 0; i < numhooks; i++){
1940
direntry = direntries[i];
1942
fprintf_plus(stderr, "Running network hook \"%s\"\n",
1945
pid_t hook_pid = fork();
1948
/* Raise privileges */
1949
errno = raise_privileges_permanently();
1951
perror_plus("Failed to raise privileges");
1958
perror_plus("setgid");
1961
/* Reset supplementary groups */
1963
ret = setgroups(0, NULL);
1965
perror_plus("setgroups");
1968
ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);
1970
perror_plus("setenv");
1973
ret = setenv("DEVICE", interface, 1);
1975
perror_plus("setenv");
1978
ret = setenv("VERBOSITY", debug ? "1" : "0", 1);
1980
perror_plus("setenv");
1983
ret = setenv("MODE", mode, 1);
1985
perror_plus("setenv");
1989
ret = asprintf(&delaystring, "%f", (double)delay);
1991
perror_plus("asprintf");
1994
ret = setenv("DELAY", delaystring, 1);
1997
perror_plus("setenv");
2001
if(connect_to != NULL){
2002
ret = setenv("CONNECT", connect_to, 1);
2004
perror_plus("setenv");
2008
int hook_fd = (int)TEMP_FAILURE_RETRY(openat(hookdir_fd,
2012
perror_plus("openat");
2013
_exit(EXIT_FAILURE);
2015
if(close(hookdir_fd) == -1){
2016
perror_plus("close");
2017
_exit(EXIT_FAILURE);
2019
ret = dup2(devnull, STDIN_FILENO);
2021
perror_plus("dup2(devnull, STDIN_FILENO)");
2024
ret = close(devnull);
2026
perror_plus("close");
2029
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
2031
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
2034
if(fexecve(hook_fd, (char *const []){ direntry->d_name, NULL },
2036
perror_plus("fexecve");
2037
_exit(EXIT_FAILURE);
2041
perror_plus("fork");
2046
if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){
2047
perror_plus("waitpid");
2051
if(WIFEXITED(status)){
2052
if(WEXITSTATUS(status) != 0){
2053
fprintf_plus(stderr, "Warning: network hook \"%s\" exited"
2054
" with status %d\n", direntry->d_name,
2055
WEXITSTATUS(status));
2059
} else if(WIFSIGNALED(status)){
2060
fprintf_plus(stderr, "Warning: network hook \"%s\" died by"
2061
" signal %d\n", direntry->d_name,
2066
fprintf_plus(stderr, "Warning: network hook \"%s\""
2067
" crashed\n", direntry->d_name);
2073
fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",
2079
if(close(hookdir_fd) == -1){
2080
perror_plus("close");
2087
__attribute__((nonnull, warn_unused_result))
2088
error_t bring_up_interface(const char *const interface,
2090
error_t old_errno = errno;
2092
struct ifreq network;
2093
unsigned int if_index = if_nametoindex(interface);
2095
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
2105
if(not interface_is_up(interface)){
2106
error_t ret_errno = 0, ioctl_errno = 0;
2107
if(not get_flags(interface, &network)){
2109
fprintf_plus(stderr, "Failed to get flags for interface "
2110
"\"%s\"\n", interface);
2114
network.ifr_flags |= IFF_UP; /* set flag */
2116
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
2119
perror_plus("socket");
2127
perror_plus("close");
2134
fprintf_plus(stderr, "Bringing up interface \"%s\"\n",
2138
/* Raise privileges */
2139
ret_errno = raise_privileges();
2142
perror_plus("Failed to raise privileges");
2147
bool restore_loglevel = false;
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");
2155
restore_loglevel = true;
2158
#endif /* __linux__ */
2159
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
2160
ioctl_errno = errno;
2162
if(restore_loglevel){
2163
ret_linux = klogctl(7, NULL, 0);
2164
if(ret_linux == -1){
2165
perror_plus("klogctl");
2168
#endif /* __linux__ */
2170
/* If raise_privileges() succeeded above */
2172
/* Lower privileges */
2173
ret_errno = lower_privileges();
2176
perror_plus("Failed to lower privileges");
2180
/* Close the socket */
2183
perror_plus("close");
2186
if(ret_setflags == -1){
2187
errno = ioctl_errno;
2188
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
2193
fprintf_plus(stderr, "Interface \"%s\" is already up; good\n",
2197
/* Sleep checking until interface is running.
2198
Check every 0.25s, up to total time of delay */
2199
for(int i=0; i < delay * 4; i++){
2200
if(interface_is_running(interface)){
2203
struct timespec sleeptime = { .tv_nsec = 250000000 };
2204
ret = nanosleep(&sleeptime, NULL);
2205
if(ret == -1 and errno != EINTR){
2206
perror_plus("nanosleep");
2214
__attribute__((nonnull, warn_unused_result))
2215
error_t take_down_interface(const char *const interface){
2216
error_t old_errno = errno;
2217
struct ifreq network;
2218
unsigned int if_index = if_nametoindex(interface);
2220
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
2224
if(interface_is_up(interface)){
2225
error_t ret_errno = 0, ioctl_errno = 0;
2226
if(not get_flags(interface, &network) and debug){
2228
fprintf_plus(stderr, "Failed to get flags for interface "
2229
"\"%s\"\n", interface);
2233
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
2235
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
2238
perror_plus("socket");
2244
fprintf_plus(stderr, "Taking down interface \"%s\"\n",
2248
/* Raise privileges */
2249
ret_errno = raise_privileges();
2252
perror_plus("Failed to raise privileges");
2255
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
2256
ioctl_errno = errno;
2258
/* If raise_privileges() succeeded above */
2260
/* Lower privileges */
2261
ret_errno = lower_privileges();
2264
perror_plus("Failed to lower privileges");
2268
/* Close the socket */
2269
int ret = close(sd);
2271
perror_plus("close");
2274
if(ret_setflags == -1){
2275
errno = ioctl_errno;
2276
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
2281
fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",
979
2289
int main(int argc, char *argv[]){
2290
mandos_context mc = { .server = NULL, .dh_bits = 0,
2291
.priority = "SECURE256:!CTYPE-X.509"
2292
":+CTYPE-OPENPGP:!RSA:+SIGN-DSA-SHA256",
2293
.current_server = NULL, .interfaces = NULL,
2294
.interfaces_size = 0 };
980
2295
AvahiSServiceBrowser *sb = NULL;
983
2298
intmax_t tmpmax;
985
2300
int exitcode = EXIT_SUCCESS;
986
const char *interface = "eth0";
987
struct ifreq network;
989
bool take_down_interface = false;
992
char *connect_to = NULL;
993
char tempdir[] = "/tmp/mandosXXXXXX";
994
bool tempdir_created = false;
2301
char *interfaces_to_take_down = NULL;
2302
size_t interfaces_to_take_down_size = 0;
2303
char run_tempdir[] = "/run/tmp/mandosXXXXXX";
2304
char old_tempdir[] = "/tmp/mandosXXXXXX";
2305
char *tempdir = NULL;
995
2306
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
996
2307
const char *seckey = PATHDIR "/" SECKEY;
997
2308
const char *pubkey = PATHDIR "/" PUBKEY;
2309
const char *dh_params_file = NULL;
2310
char *interfaces_hooks = NULL;
999
2312
bool gnutls_initialized = false;
1000
2313
bool gpgme_initialized = false;
1001
2314
float delay = 2.5f;
2315
double retry_interval = 10; /* 10s between trying a server and
2316
retrying the same server again */
1003
struct sigaction old_sigterm_action;
2318
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
1004
2319
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
1006
2321
uid = getuid();
1097
2441
delay = strtof(arg, &tmp);
1098
2442
if(errno != 0 or tmp == arg or *tmp != '\0'){
1099
fprintf(stderr, "Bad delay\n");
2443
argp_error(state, "Bad delay");
2445
case 132: /* --retry */
2447
retry_interval = strtod(arg, &tmp);
2448
if(errno != 0 or tmp == arg or *tmp != '\0'
2449
or (retry_interval * 1000) > INT_MAX
2450
or retry_interval < 0){
2451
argp_error(state, "Bad retry interval");
2454
case 133: /* --network-hook-dir */
2458
* These reproduce what we would get without ARGP_NO_HELP
2460
case '?': /* --help */
2461
argp_state_help(state, state->out_stream,
2462
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
2463
& ~(unsigned int)ARGP_HELP_EXIT_OK);
2464
case -3: /* --usage */
2465
argp_state_help(state, state->out_stream,
2466
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
2467
case 'V': /* --version */
2468
fprintf_plus(state->out_stream, "%s\n", argp_program_version);
2469
exit(argp_err_exit_status);
1108
2472
return ARGP_ERR_UNKNOWN;
1113
2477
struct argp argp = { .options = options, .parser = parse_opt,
1114
2478
.args_doc = "",
1115
2479
.doc = "Mandos client -- Get and decrypt"
1116
2480
" passwords from a Mandos server" };
1117
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
1118
if(ret == ARGP_ERR_UNKNOWN){
1119
fprintf(stderr, "Unknown error while parsing arguments\n");
1120
exitcode = EXIT_FAILURE;
2481
ret = argp_parse(&argp, argc, argv,
2482
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
2489
perror_plus("argp_parse");
2490
exitcode = EX_OSERR;
2493
exitcode = EX_USAGE;
2499
/* Work around Debian bug #633582:
2500
<http://bugs.debian.org/633582> */
2502
/* Re-raise privileges */
2503
ret_errno = raise_privileges();
2506
perror_plus("Failed to raise privileges");
2510
if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){
2511
int seckey_fd = open(seckey, O_RDONLY);
2512
if(seckey_fd == -1){
2513
perror_plus("open");
2515
ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));
2517
perror_plus("fstat");
2519
if(S_ISREG(st.st_mode)
2520
and st.st_uid == 0 and st.st_gid == 0){
2521
ret = fchown(seckey_fd, uid, gid);
2523
perror_plus("fchown");
2531
if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){
2532
int pubkey_fd = open(pubkey, O_RDONLY);
2533
if(pubkey_fd == -1){
2534
perror_plus("open");
2536
ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));
2538
perror_plus("fstat");
2540
if(S_ISREG(st.st_mode)
2541
and st.st_uid == 0 and st.st_gid == 0){
2542
ret = fchown(pubkey_fd, uid, gid);
2544
perror_plus("fchown");
2552
if(dh_params_file != NULL
2553
and strcmp(dh_params_file, PATHDIR "/dhparams.pem" ) == 0){
2554
int dhparams_fd = open(dh_params_file, O_RDONLY);
2555
if(dhparams_fd == -1){
2556
perror_plus("open");
2558
ret = (int)TEMP_FAILURE_RETRY(fstat(dhparams_fd, &st));
2560
perror_plus("fstat");
2562
if(S_ISREG(st.st_mode)
2563
and st.st_uid == 0 and st.st_gid == 0){
2564
ret = fchown(dhparams_fd, uid, gid);
2566
perror_plus("fchown");
2574
/* Lower privileges */
2575
ret_errno = lower_privileges();
2578
perror_plus("Failed to lower privileges");
2583
/* Remove invalid interface names (except "none") */
2585
char *interface = NULL;
2586
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2588
if(strcmp(interface, "none") != 0
2589
and if_nametoindex(interface) == 0){
2590
if(interface[0] != '\0'){
2591
fprintf_plus(stderr, "Not using nonexisting interface"
2592
" \"%s\"\n", interface);
2594
argz_delete(&mc.interfaces, &mc.interfaces_size, interface);
2600
/* Run network hooks */
2602
if(mc.interfaces != NULL){
2603
interfaces_hooks = malloc(mc.interfaces_size);
2604
if(interfaces_hooks == NULL){
2605
perror_plus("malloc");
2608
memcpy(interfaces_hooks, mc.interfaces, mc.interfaces_size);
2609
argz_stringify(interfaces_hooks, mc.interfaces_size, (int)',');
2611
run_network_hooks("start", interfaces_hooks != NULL ?
2612
interfaces_hooks : "", delay);
1163
2654
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1165
perror("sigaction");
1166
return EXIT_FAILURE;
2656
perror_plus("sigaction");
1168
2659
if(old_sigterm_action.sa_handler != SIG_IGN){
1169
2660
ret = sigaction(SIGINT, &sigterm_action, NULL);
1171
perror("sigaction");
1172
exitcode = EXIT_FAILURE;
2662
perror_plus("sigaction");
2663
exitcode = EX_OSERR;
1176
2667
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1178
perror("sigaction");
1179
return EXIT_FAILURE;
2669
perror_plus("sigaction");
1181
2672
if(old_sigterm_action.sa_handler != SIG_IGN){
1182
2673
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1184
perror("sigaction");
1185
exitcode = EXIT_FAILURE;
2675
perror_plus("sigaction");
2676
exitcode = EX_OSERR;
1189
2680
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1191
perror("sigaction");
1192
return EXIT_FAILURE;
2682
perror_plus("sigaction");
1194
2685
if(old_sigterm_action.sa_handler != SIG_IGN){
1195
2686
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1197
perror("sigaction");
1198
exitcode = EXIT_FAILURE;
1203
/* If the interface is down, bring it up */
1204
if(interface[0] != '\0'){
1205
if_index = (AvahiIfIndex) if_nametoindex(interface);
1207
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1208
exitcode = EXIT_FAILURE;
1216
/* Re-raise priviliges */
1224
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1225
messages to mess up the prompt */
1226
ret = klogctl(8, NULL, 5);
1227
bool restore_loglevel = true;
1229
restore_loglevel = false;
1232
#endif /* __linux__ */
1234
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1237
exitcode = EXIT_FAILURE;
1239
if(restore_loglevel){
1240
ret = klogctl(7, NULL, 0);
1245
#endif /* __linux__ */
1246
/* Lower privileges */
1254
strcpy(network.ifr_name, interface);
1255
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1257
perror("ioctl SIOCGIFFLAGS");
1259
if(restore_loglevel){
1260
ret = klogctl(7, NULL, 0);
1265
#endif /* __linux__ */
1266
exitcode = EXIT_FAILURE;
1267
/* Lower privileges */
1275
if((network.ifr_flags & IFF_UP) == 0){
1276
network.ifr_flags |= IFF_UP;
1277
take_down_interface = true;
1278
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1280
take_down_interface = false;
1281
perror("ioctl SIOCSIFFLAGS");
1282
exitcode = EXIT_FAILURE;
1284
if(restore_loglevel){
1285
ret = klogctl(7, NULL, 0);
2688
perror_plus("sigaction");
2689
exitcode = EX_OSERR;
2694
/* If no interfaces were specified, make a list */
2695
if(mc.interfaces == NULL){
2696
struct dirent **direntries = NULL;
2697
/* Look for any good interfaces */
2698
ret = scandir(sys_class_net, &direntries, good_interface,
2701
/* Add all found interfaces to interfaces list */
2702
for(int i = 0; i < ret; ++i){
2703
ret_errno = argz_add(&mc.interfaces, &mc.interfaces_size,
2704
direntries[i]->d_name);
2707
perror_plus("argz_add");
2708
free(direntries[i]);
2712
fprintf_plus(stderr, "Will use interface \"%s\"\n",
2713
direntries[i]->d_name);
2715
free(direntries[i]);
2722
fprintf_plus(stderr, "Could not find a network interface\n");
2723
exitcode = EXIT_FAILURE;
2728
/* Bring up interfaces which are down, and remove any "none"s */
2730
char *interface = NULL;
2731
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2733
/* If interface name is "none", stop bringing up interfaces.
2734
Also remove all instances of "none" from the list */
2735
if(strcmp(interface, "none") == 0){
2736
argz_delete(&mc.interfaces, &mc.interfaces_size,
2739
while((interface = argz_next(mc.interfaces,
2740
mc.interfaces_size, interface))){
2741
if(strcmp(interface, "none") == 0){
2742
argz_delete(&mc.interfaces, &mc.interfaces_size,
1290
#endif /* __linux__ */
1291
/* Lower privileges */
1300
/* sleep checking until interface is running */
1301
for(int i=0; i < delay * 4; i++){
1302
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1304
perror("ioctl SIOCGIFFLAGS");
1305
} else if(network.ifr_flags & IFF_RUNNING){
1308
struct timespec sleeptime = { .tv_nsec = 250000000 };
1309
ret = nanosleep(&sleeptime, NULL);
1310
if(ret == -1 and errno != EINTR){
1311
perror("nanosleep");
1314
if(not take_down_interface){
1315
/* We won't need the socket anymore */
1316
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1322
if(restore_loglevel){
1323
/* Restores kernel loglevel to default */
1324
ret = klogctl(7, NULL, 0);
1329
#endif /* __linux__ */
1330
/* Lower privileges */
1332
if(take_down_interface){
1333
/* Lower privileges */
1339
/* Lower privileges permanently */
2749
bool interface_was_up = interface_is_up(interface);
2750
errno = bring_up_interface(interface, delay);
2751
if(not interface_was_up){
2753
fprintf_plus(stderr, "Failed to bring up interface \"%s\":"
2754
" %s\n", interface, strerror(errno));
2756
errno = argz_add(&interfaces_to_take_down,
2757
&interfaces_to_take_down_size,
2760
perror_plus("argz_add");
2765
if(debug and (interfaces_to_take_down == NULL)){
2766
fprintf_plus(stderr, "No interfaces were brought up\n");
2770
/* If we only got one interface, explicitly use only that one */
2771
if(argz_count(mc.interfaces, mc.interfaces_size) == 1){
2773
fprintf_plus(stderr, "Using only interface \"%s\"\n",
2776
if_index = (AvahiIfIndex)if_nametoindex(mc.interfaces);
1351
ret = init_gnutls_global(pubkey, seckey);
2783
ret = init_gnutls_global(pubkey, seckey, dh_params_file, &mc);
1353
fprintf(stderr, "init_gnutls_global failed\n");
1354
exitcode = EXIT_FAILURE;
2785
fprintf_plus(stderr, "init_gnutls_global failed\n");
2786
exitcode = EX_UNAVAILABLE;
1357
2789
gnutls_initialized = true;
1519
2983
gpgme_release(mc.ctx);
1522
/* Take down the network interface */
1523
if(take_down_interface){
1524
/* Re-raise priviliges */
1531
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1533
perror("ioctl SIOCGIFFLAGS");
1534
} else if(network.ifr_flags & IFF_UP) {
1535
network.ifr_flags &= ~IFF_UP; /* clear flag */
1536
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1538
perror("ioctl SIOCSIFFLAGS");
1541
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1545
/* Lower privileges permanently */
1554
/* Removes the temp directory used by GPGME */
1555
if(tempdir_created){
1557
struct dirent *direntry;
1558
d = opendir(tempdir);
1560
if(errno != ENOENT){
1565
direntry = readdir(d);
1566
if(direntry == NULL){
1569
/* Skip "." and ".." */
1570
if(direntry->d_name[0] == '.'
1571
and (direntry->d_name[1] == '\0'
1572
or (direntry->d_name[1] == '.'
1573
and direntry->d_name[2] == '\0'))){
1576
char *fullname = NULL;
1577
ret = asprintf(&fullname, "%s/%s", tempdir,
1583
ret = remove(fullname);
1585
fprintf(stderr, "remove(\"%s\"): %s\n", fullname,
1592
ret = rmdir(tempdir);
1593
if(ret == -1 and errno != ENOENT){
2986
/* Cleans up the circular linked list of Mandos servers the client
2988
if(mc.current_server != NULL){
2989
mc.current_server->prev->next = NULL;
2990
while(mc.current_server != NULL){
2991
server *next = mc.current_server->next;
2993
#pragma GCC diagnostic push
2994
#pragma GCC diagnostic ignored "-Wcast-qual"
2996
free((char *)(mc.current_server->ip));
2998
#pragma GCC diagnostic pop
3000
free(mc.current_server);
3001
mc.current_server = next;
3005
/* Re-raise privileges */
3007
ret_errno = raise_privileges();
3010
perror_plus("Failed to raise privileges");
3013
/* Run network hooks */
3014
run_network_hooks("stop", interfaces_hooks != NULL ?
3015
interfaces_hooks : "", delay);
3017
/* Take down the network interfaces which were brought up */
3019
char *interface = NULL;
3020
while((interface=argz_next(interfaces_to_take_down,
3021
interfaces_to_take_down_size,
3023
ret_errno = take_down_interface(interface);
3026
perror_plus("Failed to take down interface");
3029
if(debug and (interfaces_to_take_down == NULL)){
3030
fprintf_plus(stderr, "No interfaces needed to be taken"
3036
ret_errno = lower_privileges_permanently();
3039
perror_plus("Failed to lower privileges permanently");
3043
free(interfaces_to_take_down);
3044
free(interfaces_hooks);
3046
/* Removes the GPGME temp directory and all files inside */
3047
if(tempdir != NULL){
3048
struct dirent **direntries = NULL;
3049
int tempdir_fd = (int)TEMP_FAILURE_RETRY(open(tempdir, O_RDONLY
3053
if(tempdir_fd == -1){
3054
perror_plus("open");
3057
#if __GLIBC_PREREQ(2, 15)
3058
int numentries = scandirat(tempdir_fd, ".", &direntries,
3059
notdotentries, alphasort);
3060
#else /* not __GLIBC_PREREQ(2, 15) */
3061
int numentries = scandir(tempdir, &direntries, notdotentries,
3063
#endif /* not __GLIBC_PREREQ(2, 15) */
3064
#else /* not __GLIBC__ */
3065
int numentries = scandir(tempdir, &direntries, notdotentries,
3067
#endif /* not __GLIBC__ */
3068
if(numentries >= 0){
3069
for(int i = 0; i < numentries; i++){
3070
ret = unlinkat(tempdir_fd, direntries[i]->d_name, 0);
3072
fprintf_plus(stderr, "unlinkat(open(\"%s\", O_RDONLY),"
3073
" \"%s\", 0): %s\n", tempdir,
3074
direntries[i]->d_name, strerror(errno));
3076
free(direntries[i]);
3079
/* need to clean even if 0 because man page doesn't specify */
3081
if(numentries == -1){
3082
perror_plus("scandir");
3084
ret = rmdir(tempdir);
3085
if(ret == -1 and errno != ENOENT){
3086
perror_plus("rmdir");
1599
3094
sigemptyset(&old_sigterm_action.sa_mask);
1600
3095
old_sigterm_action.sa_handler = SIG_DFL;
1601
ret = sigaction(signal_received, &old_sigterm_action, NULL);
3096
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
3097
&old_sigterm_action,
1603
perror("sigaction");
1605
raise(signal_received);
3100
perror_plus("sigaction");
3103
ret = raise(signal_received);
3104
} while(ret != 0 and errno == EINTR);
3106
perror_plus("raise");
3109
TEMP_FAILURE_RETRY(pause());
1608
3112
return exitcode;