121
133
#define PATHDIR "/conf/conf.d/mandos"
122
134
#define SECKEY "seckey.txt"
123
135
#define PUBKEY "pubkey.txt"
136
#define HOOKDIR "/lib/mandos/network-hooks.d"
125
138
bool debug = false;
126
139
static const char mandos_protocol_version[] = "1";
127
140
const char *argp_program_version = "mandos-client " VERSION;
128
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;
130
160
/* Used for passing in values through the Avahi callback functions */
132
AvahiSimplePoll *simple_poll;
133
162
AvahiServer *server;
134
163
gnutls_certificate_credentials_t cred;
135
164
unsigned int dh_bits;
136
165
gnutls_dh_params_t dh_params;
137
166
const char *priority;
168
server *current_server;
170
size_t interfaces_size;
139
171
} mandos_context;
141
/* global context so signal handler can reach it*/
142
mandos_context mc = { .simple_poll = NULL, .server = NULL,
143
.dh_bits = 1024, .priority = "SECURE256"
144
":!CTYPE-X.509:+CTYPE-OPENPGP" };
173
/* global so signal handler can reach it*/
174
AvahiSimplePoll *simple_poll;
146
176
sig_atomic_t quit_now = 0;
147
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));
150
199
* Make additional room in "buffer" for at least BUFFER_SIZE more
151
200
* bytes. "buffer_capacity" is how much is currently allocated,
152
201
* "buffer_length" is how much is already used.
203
__attribute__((nonnull, warn_unused_result))
154
204
size_t incbuffer(char **buffer, size_t buffer_length,
155
size_t buffer_capacity){
205
size_t buffer_capacity){
156
206
if(buffer_length + BUFFER_SIZE > buffer_capacity){
157
*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
207
char *new_buf = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
209
int old_errno = errno;
161
216
buffer_capacity += BUFFER_SIZE;
163
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;
167
270
* Initialize GPGME.
169
static bool init_gpgme(const char *seckey,
170
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,
171
277
gpgme_error_t rc;
172
278
gpgme_engine_info_t engine_info;
176
281
* Helper function to insert pub and seckey to the engine keyring.
178
bool import_key(const char *filename){
283
bool import_key(const char * const filename){
181
286
gpgme_data_t pgp_data;
183
288
fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
189
294
rc = gpgme_data_new_from_fd(&pgp_data, fd);
190
295
if(rc != GPG_ERR_NO_ERROR){
191
fprintf(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
192
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));
196
rc = gpgme_op_import(mc.ctx, pgp_data);
301
rc = gpgme_op_import(mc->ctx, pgp_data);
197
302
if(rc != GPG_ERR_NO_ERROR){
198
fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
199
gpgme_strsource(rc), gpgme_strerror(rc));
303
fprintf_plus(stderr, "bad gpgme_op_import: %s: %s\n",
304
gpgme_strsource(rc), gpgme_strerror(rc));
203
308
ret = (int)TEMP_FAILURE_RETRY(close(fd));
310
perror_plus("close");
207
312
gpgme_data_release(pgp_data);
212
fprintf(stderr, "Initializing GPGME\n");
317
fprintf_plus(stderr, "Initializing GPGME\n");
216
321
gpgme_check_version(NULL);
217
322
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
218
323
if(rc != GPG_ERR_NO_ERROR){
219
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
220
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));
224
/* Set GPGME home directory for the OpenPGP engine only */
329
/* Set GPGME home directory for the OpenPGP engine only */
225
330
rc = gpgme_get_engine_info(&engine_info);
226
331
if(rc != GPG_ERR_NO_ERROR){
227
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
228
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));
231
336
while(engine_info != NULL){
270
379
ssize_t plaintext_length = 0;
273
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
382
fprintf_plus(stderr, "Trying to decrypt OpenPGP data\n");
276
385
/* Create new GPGME data buffer from memory cryptotext */
277
386
rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,
279
388
if(rc != GPG_ERR_NO_ERROR){
280
fprintf(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
281
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));
285
394
/* Create new empty GPGME data buffer for the plaintext */
286
395
rc = gpgme_data_new(&dh_plain);
287
396
if(rc != GPG_ERR_NO_ERROR){
288
fprintf(stderr, "bad gpgme_data_new: %s: %s\n",
289
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));
290
400
gpgme_data_release(dh_crypto);
294
404
/* Decrypt data from the cryptotext data buffer to the plaintext
296
rc = gpgme_op_decrypt(mc.ctx, dh_crypto, dh_plain);
406
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
297
407
if(rc != GPG_ERR_NO_ERROR){
298
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
299
gpgme_strsource(rc), gpgme_strerror(rc));
408
fprintf_plus(stderr, "bad gpgme_op_decrypt: %s: %s\n",
409
gpgme_strsource(rc), gpgme_strerror(rc));
300
410
plaintext_length = -1;
302
412
gpgme_decrypt_result_t result;
303
result = gpgme_op_decrypt_result(mc.ctx);
413
result = gpgme_op_decrypt_result(mc->ctx);
304
414
if(result == NULL){
305
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
415
fprintf_plus(stderr, "gpgme_op_decrypt_result failed\n");
307
fprintf(stderr, "Unsupported algorithm: %s\n",
308
result->unsupported_algorithm);
309
fprintf(stderr, "Wrong key usage: %u\n",
310
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);
311
421
if(result->file_name != NULL){
312
fprintf(stderr, "File name: %s\n", result->file_name);
422
fprintf_plus(stderr, "File name: %s\n", result->file_name);
314
424
gpgme_recipient_t recipient;
315
425
recipient = result->recipients;
316
426
while(recipient != NULL){
317
fprintf(stderr, "Public key algorithm: %s\n",
318
gpgme_pubkey_algo_name(recipient->pubkey_algo));
319
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
320
fprintf(stderr, "Secret key available: %s\n",
321
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
323
434
recipient = recipient->next;
422
536
/* OpenPGP credentials */
423
gnutls_certificate_allocate_credentials(&mc.cred);
537
ret = gnutls_certificate_allocate_credentials(&mc->cred);
424
538
if(ret != GNUTLS_E_SUCCESS){
425
fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning
429
safer_gnutls_strerror(ret));
539
fprintf_plus(stderr, "GnuTLS memory error: %s\n",
540
safer_gnutls_strerror(ret));
430
541
gnutls_global_deinit();
435
fprintf(stderr, "Attempting to use OpenPGP public key %s and"
436
" secret key %s as GnuTLS credentials\n", pubkeyfilename,
546
fprintf_plus(stderr, "Attempting to use OpenPGP public key %s and"
547
" secret key %s as GnuTLS credentials\n",
440
552
ret = gnutls_certificate_set_openpgp_key_file
441
(mc.cred, pubkeyfilename, seckeyfilename,
553
(mc->cred, pubkeyfilename, seckeyfilename,
442
554
GNUTLS_OPENPGP_FMT_BASE64);
443
555
if(ret != GNUTLS_E_SUCCESS){
445
"Error[%d] while reading the OpenPGP key pair ('%s',"
446
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
447
fprintf(stderr, "The GnuTLS error is: %s\n",
448
safer_gnutls_strerror(ret));
557
"Error[%d] while reading the OpenPGP key pair ('%s',"
558
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
559
fprintf_plus(stderr, "The GnuTLS error is: %s\n",
560
safer_gnutls_strerror(ret));
452
564
/* GnuTLS server initialization */
453
ret = gnutls_dh_params_init(&mc.dh_params);
565
ret = gnutls_dh_params_init(&mc->dh_params);
454
566
if(ret != GNUTLS_E_SUCCESS){
455
fprintf(stderr, "Error in GnuTLS DH parameter initialization:"
456
" %s\n", safer_gnutls_strerror(ret));
567
fprintf_plus(stderr, "Error in GnuTLS DH parameter"
568
" initialization: %s\n",
569
safer_gnutls_strerror(ret));
459
ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);
572
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
460
573
if(ret != GNUTLS_E_SUCCESS){
461
fprintf(stderr, "Error in GnuTLS prime generation: %s\n",
462
safer_gnutls_strerror(ret));
574
fprintf_plus(stderr, "Error in GnuTLS prime generation: %s\n",
575
safer_gnutls_strerror(ret));
466
gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);
579
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
472
gnutls_certificate_free_credentials(mc.cred);
585
gnutls_certificate_free_credentials(mc->cred);
473
586
gnutls_global_deinit();
474
gnutls_dh_params_deinit(mc.dh_params);
587
gnutls_dh_params_deinit(mc->dh_params);
478
static int init_gnutls_session(gnutls_session_t *session){
591
__attribute__((nonnull, warn_unused_result))
592
static int init_gnutls_session(gnutls_session_t *session,
480
595
/* GnuTLS session creation */
568
fprintf(stderr, "Bad address family: %d\n", af);
685
fprintf_plus(stderr, "Bad address family: %d\n", af);
572
ret = init_gnutls_session(&session);
690
/* If the interface is specified and we have a list of interfaces */
691
if(if_index != AVAHI_IF_UNSPEC and mc->interfaces != NULL){
692
/* Check if the interface is one of the interfaces we are using */
695
char *interface = NULL;
696
while((interface=argz_next(mc->interfaces, mc->interfaces_size,
698
if(if_nametoindex(interface) == (unsigned int)if_index){
705
/* This interface does not match any in the list, so we don't
706
connect to the server */
708
char interface[IF_NAMESIZE];
709
if(if_indextoname((unsigned int)if_index, interface) == NULL){
710
perror_plus("if_indextoname");
712
fprintf_plus(stderr, "Skipping server on non-used interface"
714
if_indextoname((unsigned int)if_index,
722
ret = init_gnutls_session(&session, mc);
578
fprintf(stderr, "Setting up a TCP connection to %s, port %" PRIu16
728
fprintf_plus(stderr, "Setting up a TCP connection to %s, port %"
729
PRIuMAX "\n", ip, (uintmax_t)port);
582
732
tcp_sd = socket(pf, SOCK_STREAM, 0);
735
perror_plus("socket");
592
745
memset(&to, 0, sizeof(to));
593
746
if(af == AF_INET6){
594
to.in6.sin6_family = (sa_family_t)af;
595
ret = inet_pton(af, ip, &to.in6.sin6_addr);
747
((struct sockaddr_in6 *)&to)->sin6_family = (sa_family_t)af;
748
ret = inet_pton(af, ip, &((struct sockaddr_in6 *)&to)->sin6_addr);
596
749
} else { /* IPv4 */
597
to.in.sin_family = (sa_family_t)af;
598
ret = inet_pton(af, ip, &to.in.sin_addr);
750
((struct sockaddr_in *)&to)->sin_family = (sa_family_t)af;
751
ret = inet_pton(af, ip, &((struct sockaddr_in *)&to)->sin_addr);
755
perror_plus("inet_pton");
605
fprintf(stderr, "Bad address: %s\n", ip);
761
fprintf_plus(stderr, "Bad address: %s\n", ip);
608
765
if(af == AF_INET6){
609
to.in6.sin6_port = htons(port); /* Spurious warnings from
611
-Wunreachable-code */
613
if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */
614
(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower and
766
((struct sockaddr_in6 *)&to)->sin6_port = htons(port);
767
if(IN6_IS_ADDR_LINKLOCAL
768
(&((struct sockaddr_in6 *)&to)->sin6_addr)){
616
769
if(if_index == AVAHI_IF_UNSPEC){
617
fprintf(stderr, "An IPv6 link-local address is incomplete"
618
" without a network interface\n");
770
fprintf_plus(stderr, "An IPv6 link-local address is"
771
" incomplete without a network interface\n");
621
775
/* Set the network interface number as scope */
622
to.in6.sin6_scope_id = (uint32_t)if_index;
776
((struct sockaddr_in6 *)&to)->sin6_scope_id = (uint32_t)if_index;
625
to.in.sin_port = htons(port); /* Spurious warnings from
627
-Wunreachable-code */
779
((struct sockaddr_in *)&to)->sin_port = htons(port);
970
1187
signal_received = sig;
971
1188
int old_errno = errno;
972
if(mc.simple_poll != NULL){
973
avahi_simple_poll_quit(mc.simple_poll);
1189
/* set main loop to exit */
1190
if(simple_poll != NULL){
1191
avahi_simple_poll_quit(simple_poll);
1196
__attribute__((nonnull, warn_unused_result))
1197
bool get_flags(const char *ifname, struct ifreq *ifr){
1201
int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1204
perror_plus("socket");
1208
strcpy(ifr->ifr_name, ifname);
1209
ret = ioctl(s, SIOCGIFFLAGS, ifr);
1213
perror_plus("ioctl SIOCGIFFLAGS");
1221
__attribute__((nonnull, warn_unused_result))
1222
bool good_flags(const char *ifname, const struct ifreq *ifr){
1224
/* Reject the loopback device */
1225
if(ifr->ifr_flags & IFF_LOOPBACK){
1227
fprintf_plus(stderr, "Rejecting loopback interface \"%s\"\n",
1232
/* Accept point-to-point devices only if connect_to is specified */
1233
if(connect_to != NULL and (ifr->ifr_flags & IFF_POINTOPOINT)){
1235
fprintf_plus(stderr, "Accepting point-to-point interface"
1236
" \"%s\"\n", ifname);
1240
/* Otherwise, reject non-broadcast-capable devices */
1241
if(not (ifr->ifr_flags & IFF_BROADCAST)){
1243
fprintf_plus(stderr, "Rejecting non-broadcast interface"
1244
" \"%s\"\n", ifname);
1248
/* Reject non-ARP interfaces (including dummy interfaces) */
1249
if(ifr->ifr_flags & IFF_NOARP){
1251
fprintf_plus(stderr, "Rejecting non-ARP interface \"%s\"\n",
1257
/* Accept this device */
1259
fprintf_plus(stderr, "Interface \"%s\" is good\n", ifname);
1265
* This function determines if a directory entry in /sys/class/net
1266
* corresponds to an acceptable network device.
1267
* (This function is passed to scandir(3) as a filter function.)
1269
__attribute__((nonnull, warn_unused_result))
1270
int good_interface(const struct dirent *if_entry){
1271
if(if_entry->d_name[0] == '.'){
1276
if(not get_flags(if_entry->d_name, &ifr)){
1278
fprintf_plus(stderr, "Failed to get flags for interface "
1279
"\"%s\"\n", if_entry->d_name);
1284
if(not good_flags(if_entry->d_name, &ifr)){
1291
* This function determines if a network interface is up.
1293
__attribute__((nonnull, warn_unused_result))
1294
bool interface_is_up(const char *interface){
1296
if(not get_flags(interface, &ifr)){
1298
fprintf_plus(stderr, "Failed to get flags for interface "
1299
"\"%s\"\n", interface);
1304
return (bool)(ifr.ifr_flags & IFF_UP);
1308
* This function determines if a network interface is running
1310
__attribute__((nonnull, warn_unused_result))
1311
bool interface_is_running(const char *interface){
1313
if(not get_flags(interface, &ifr)){
1315
fprintf_plus(stderr, "Failed to get flags for interface "
1316
"\"%s\"\n", interface);
1321
return (bool)(ifr.ifr_flags & IFF_RUNNING);
1324
__attribute__((nonnull, pure, warn_unused_result))
1325
int notdotentries(const struct dirent *direntry){
1326
/* Skip "." and ".." */
1327
if(direntry->d_name[0] == '.'
1328
and (direntry->d_name[1] == '\0'
1329
or (direntry->d_name[1] == '.'
1330
and direntry->d_name[2] == '\0'))){
1336
/* Is this directory entry a runnable program? */
1337
__attribute__((nonnull, warn_unused_result))
1338
int runnable_hook(const struct dirent *direntry){
1343
if((direntry->d_name)[0] == '\0'){
1348
sret = strspn(direntry->d_name, "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
1349
"abcdefghijklmnopqrstuvwxyz"
1352
if((direntry->d_name)[sret] != '\0'){
1353
/* Contains non-allowed characters */
1355
fprintf_plus(stderr, "Ignoring hook \"%s\" with bad name\n",
1361
ret = fstatat(hookdir_fd, direntry->d_name, &st, 0);
1364
perror_plus("Could not stat hook");
1368
if(not (S_ISREG(st.st_mode))){
1369
/* Not a regular file */
1371
fprintf_plus(stderr, "Ignoring hook \"%s\" - not a file\n",
1376
if(not (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))){
1377
/* Not executable */
1379
fprintf_plus(stderr, "Ignoring hook \"%s\" - not executable\n",
1385
fprintf_plus(stderr, "Hook \"%s\" is acceptable\n",
1391
__attribute__((nonnull, warn_unused_result))
1392
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,
1393
mandos_context *mc){
1395
struct timespec now;
1396
struct timespec waited_time;
1397
intmax_t block_time;
1400
if(mc->current_server == NULL){
1402
fprintf_plus(stderr, "Wait until first server is found."
1405
ret = avahi_simple_poll_iterate(s, -1);
1408
fprintf_plus(stderr, "Check current_server if we should run"
1411
/* the current time */
1412
ret = clock_gettime(CLOCK_MONOTONIC, &now);
1414
perror_plus("clock_gettime");
1417
/* Calculating in ms how long time between now and server
1418
who we visted longest time ago. Now - last seen. */
1419
waited_time.tv_sec = (now.tv_sec
1420
- mc->current_server->last_seen.tv_sec);
1421
waited_time.tv_nsec = (now.tv_nsec
1422
- mc->current_server->last_seen.tv_nsec);
1423
/* total time is 10s/10,000ms.
1424
Converting to s from ms by dividing by 1,000,
1425
and ns to ms by dividing by 1,000,000. */
1426
block_time = ((retry_interval
1427
- ((intmax_t)waited_time.tv_sec * 1000))
1428
- ((intmax_t)waited_time.tv_nsec / 1000000));
1431
fprintf_plus(stderr, "Blocking for %" PRIdMAX " ms\n",
1435
if(block_time <= 0){
1436
ret = start_mandos_communication(mc->current_server->ip,
1437
mc->current_server->port,
1438
mc->current_server->if_index,
1439
mc->current_server->af, mc);
1441
avahi_simple_poll_quit(s);
1444
ret = clock_gettime(CLOCK_MONOTONIC,
1445
&mc->current_server->last_seen);
1447
perror_plus("clock_gettime");
1450
mc->current_server = mc->current_server->next;
1451
block_time = 0; /* Call avahi to find new Mandos
1452
servers, but don't block */
1455
ret = avahi_simple_poll_iterate(s, (int)block_time);
1458
if(ret > 0 or errno != EINTR){
1459
return (ret != 1) ? ret : 0;
1465
/* Set effective uid to 0, return errno */
1466
__attribute__((warn_unused_result))
1467
error_t raise_privileges(void){
1468
error_t old_errno = errno;
1469
error_t ret_errno = 0;
1470
if(seteuid(0) == -1){
1477
/* Set effective and real user ID to 0. Return errno. */
1478
__attribute__((warn_unused_result))
1479
error_t raise_privileges_permanently(void){
1480
error_t old_errno = errno;
1481
error_t ret_errno = raise_privileges();
1486
if(setuid(0) == -1){
1493
/* Set effective user ID to unprivileged saved user ID */
1494
__attribute__((warn_unused_result))
1495
error_t lower_privileges(void){
1496
error_t old_errno = errno;
1497
error_t ret_errno = 0;
1498
if(seteuid(uid) == -1){
1505
/* Lower privileges permanently */
1506
__attribute__((warn_unused_result))
1507
error_t lower_privileges_permanently(void){
1508
error_t old_errno = errno;
1509
error_t ret_errno = 0;
1510
if(setuid(uid) == -1){
1517
__attribute__((nonnull))
1518
void run_network_hooks(const char *mode, const char *interface,
1520
struct dirent **direntries = NULL;
1521
if(hookdir_fd == -1){
1522
hookdir_fd = open(hookdir, O_RDONLY);
1523
if(hookdir_fd == -1){
1524
if(errno == ENOENT){
1526
fprintf_plus(stderr, "Network hook directory \"%s\" not"
1527
" found\n", hookdir);
1530
perror_plus("open");
1536
#if __GLIBC_PREREQ(2, 15)
1537
int numhooks = scandirat(hookdir_fd, ".", &direntries,
1538
runnable_hook, alphasort);
1539
#else /* not __GLIBC_PREREQ(2, 15) */
1540
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1542
#endif /* not __GLIBC_PREREQ(2, 15) */
1543
#else /* not __GLIBC__ */
1544
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1546
#endif /* not __GLIBC__ */
1548
perror_plus("scandir");
1551
struct dirent *direntry;
1553
int devnull = open("/dev/null", O_RDONLY);
1554
for(int i = 0; i < numhooks; i++){
1555
direntry = direntries[i];
1557
fprintf_plus(stderr, "Running network hook \"%s\"\n",
1560
pid_t hook_pid = fork();
1563
/* Raise privileges */
1564
errno = raise_privileges_permanently();
1566
perror_plus("Failed to raise privileges");
1573
perror_plus("setgid");
1576
/* Reset supplementary groups */
1578
ret = setgroups(0, NULL);
1580
perror_plus("setgroups");
1583
ret = dup2(devnull, STDIN_FILENO);
1585
perror_plus("dup2(devnull, STDIN_FILENO)");
1588
ret = close(devnull);
1590
perror_plus("close");
1593
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
1595
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
1598
ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);
1600
perror_plus("setenv");
1603
ret = setenv("DEVICE", interface, 1);
1605
perror_plus("setenv");
1608
ret = setenv("VERBOSITY", debug ? "1" : "0", 1);
1610
perror_plus("setenv");
1613
ret = setenv("MODE", mode, 1);
1615
perror_plus("setenv");
1619
ret = asprintf(&delaystring, "%f", (double)delay);
1621
perror_plus("asprintf");
1624
ret = setenv("DELAY", delaystring, 1);
1627
perror_plus("setenv");
1631
if(connect_to != NULL){
1632
ret = setenv("CONNECT", connect_to, 1);
1634
perror_plus("setenv");
1638
int hook_fd = openat(hookdir_fd, direntry->d_name, O_RDONLY);
1640
perror_plus("openat");
1641
_exit(EXIT_FAILURE);
1643
if((int)TEMP_FAILURE_RETRY(close(hookdir_fd)) == -1){
1644
perror_plus("close");
1645
_exit(EXIT_FAILURE);
1647
if(fexecve(hook_fd, (char *const []){ direntry->d_name, NULL },
1649
perror_plus("fexecve");
1650
_exit(EXIT_FAILURE);
1654
perror_plus("fork");
1659
if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){
1660
perror_plus("waitpid");
1664
if(WIFEXITED(status)){
1665
if(WEXITSTATUS(status) != 0){
1666
fprintf_plus(stderr, "Warning: network hook \"%s\" exited"
1667
" with status %d\n", direntry->d_name,
1668
WEXITSTATUS(status));
1672
} else if(WIFSIGNALED(status)){
1673
fprintf_plus(stderr, "Warning: network hook \"%s\" died by"
1674
" signal %d\n", direntry->d_name,
1679
fprintf_plus(stderr, "Warning: network hook \"%s\""
1680
" crashed\n", direntry->d_name);
1686
fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",
1692
if((int)TEMP_FAILURE_RETRY(close(hookdir_fd)) == -1){
1693
perror_plus("close");
1700
__attribute__((nonnull, warn_unused_result))
1701
error_t bring_up_interface(const char *const interface,
1703
error_t old_errno = errno;
1705
struct ifreq network;
1706
unsigned int if_index = if_nametoindex(interface);
1708
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1718
if(not interface_is_up(interface)){
1719
error_t ret_errno = 0, ioctl_errno = 0;
1720
if(not get_flags(interface, &network)){
1722
fprintf_plus(stderr, "Failed to get flags for interface "
1723
"\"%s\"\n", interface);
1727
network.ifr_flags |= IFF_UP; /* set flag */
1729
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1732
perror_plus("socket");
1738
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1740
perror_plus("close");
1747
fprintf_plus(stderr, "Bringing up interface \"%s\"\n",
1751
/* Raise privileges */
1752
ret_errno = raise_privileges();
1755
perror_plus("Failed to raise privileges");
1760
bool restore_loglevel = false;
1762
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1763
messages about the network interface to mess up the prompt */
1764
ret_linux = klogctl(8, NULL, 5);
1765
if(ret_linux == -1){
1766
perror_plus("klogctl");
1768
restore_loglevel = true;
1771
#endif /* __linux__ */
1772
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1773
ioctl_errno = errno;
1775
if(restore_loglevel){
1776
ret_linux = klogctl(7, NULL, 0);
1777
if(ret_linux == -1){
1778
perror_plus("klogctl");
1781
#endif /* __linux__ */
1783
/* If raise_privileges() succeeded above */
1785
/* Lower privileges */
1786
ret_errno = lower_privileges();
1789
perror_plus("Failed to lower privileges");
1793
/* Close the socket */
1794
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1796
perror_plus("close");
1799
if(ret_setflags == -1){
1800
errno = ioctl_errno;
1801
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1806
fprintf_plus(stderr, "Interface \"%s\" is already up; good\n",
1810
/* Sleep checking until interface is running.
1811
Check every 0.25s, up to total time of delay */
1812
for(int i=0; i < delay * 4; i++){
1813
if(interface_is_running(interface)){
1816
struct timespec sleeptime = { .tv_nsec = 250000000 };
1817
ret = nanosleep(&sleeptime, NULL);
1818
if(ret == -1 and errno != EINTR){
1819
perror_plus("nanosleep");
1827
__attribute__((nonnull, warn_unused_result))
1828
error_t take_down_interface(const char *const interface){
1829
error_t old_errno = errno;
1830
struct ifreq network;
1831
unsigned int if_index = if_nametoindex(interface);
1833
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1837
if(interface_is_up(interface)){
1838
error_t ret_errno = 0, ioctl_errno = 0;
1839
if(not get_flags(interface, &network) and debug){
1841
fprintf_plus(stderr, "Failed to get flags for interface "
1842
"\"%s\"\n", interface);
1846
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1848
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1851
perror_plus("socket");
1857
fprintf_plus(stderr, "Taking down interface \"%s\"\n",
1861
/* Raise privileges */
1862
ret_errno = raise_privileges();
1865
perror_plus("Failed to raise privileges");
1868
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1869
ioctl_errno = errno;
1871
/* If raise_privileges() succeeded above */
1873
/* Lower privileges */
1874
ret_errno = lower_privileges();
1877
perror_plus("Failed to lower privileges");
1881
/* Close the socket */
1882
int ret = (int)TEMP_FAILURE_RETRY(close(sd));
1884
perror_plus("close");
1887
if(ret_setflags == -1){
1888
errno = ioctl_errno;
1889
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
1894
fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",
978
1902
int main(int argc, char *argv[]){
1903
mandos_context mc = { .server = NULL, .dh_bits = 1024,
1904
.priority = "SECURE256:!CTYPE-X.509:"
1905
"+CTYPE-OPENPGP", .current_server = NULL,
1906
.interfaces = NULL, .interfaces_size = 0 };
979
1907
AvahiSServiceBrowser *sb = NULL;
982
1910
intmax_t tmpmax;
984
1912
int exitcode = EXIT_SUCCESS;
985
const char *interface = "eth0";
986
struct ifreq network;
988
bool take_down_interface = false;
991
char *connect_to = NULL;
992
char tempdir[] = "/tmp/mandosXXXXXX";
993
bool tempdir_created = false;
1913
char *interfaces_to_take_down = NULL;
1914
size_t interfaces_to_take_down_size = 0;
1915
char run_tempdir[] = "/run/tmp/mandosXXXXXX";
1916
char old_tempdir[] = "/tmp/mandosXXXXXX";
1917
char *tempdir = NULL;
994
1918
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
995
1919
const char *seckey = PATHDIR "/" SECKEY;
996
1920
const char *pubkey = PATHDIR "/" PUBKEY;
1921
char *interfaces_hooks = NULL;
998
1923
bool gnutls_initialized = false;
999
1924
bool gpgme_initialized = false;
1000
1925
float delay = 2.5f;
1926
double retry_interval = 10; /* 10s between trying a server and
1927
retrying the same server again */
1002
1929
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
1003
1930
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
1189
2235
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1191
perror("sigaction");
1192
return EXIT_FAILURE;
2237
perror_plus("sigaction");
1194
2240
if(old_sigterm_action.sa_handler != SIG_IGN){
1195
2241
ret = sigaction(SIGINT, &sigterm_action, NULL);
1197
perror("sigaction");
1198
exitcode = EXIT_FAILURE;
2243
perror_plus("sigaction");
2244
exitcode = EX_OSERR;
1202
2248
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1204
perror("sigaction");
1205
return EXIT_FAILURE;
2250
perror_plus("sigaction");
1207
2253
if(old_sigterm_action.sa_handler != SIG_IGN){
1208
2254
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1210
perror("sigaction");
1211
exitcode = EXIT_FAILURE;
2256
perror_plus("sigaction");
2257
exitcode = EX_OSERR;
1215
2261
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1217
perror("sigaction");
1218
return EXIT_FAILURE;
2263
perror_plus("sigaction");
1220
2266
if(old_sigterm_action.sa_handler != SIG_IGN){
1221
2267
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1223
perror("sigaction");
1224
exitcode = EXIT_FAILURE;
1229
/* If the interface is down, bring it up */
1230
if(interface[0] != '\0'){
1231
if_index = (AvahiIfIndex) if_nametoindex(interface);
1233
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1234
exitcode = EXIT_FAILURE;
1242
/* Re-raise priviliges */
1250
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1251
messages about the network interface to mess up the prompt */
1252
ret = klogctl(8, NULL, 5);
1253
bool restore_loglevel = true;
1255
restore_loglevel = false;
1258
#endif /* __linux__ */
1260
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1263
exitcode = EXIT_FAILURE;
1265
if(restore_loglevel){
1266
ret = klogctl(7, NULL, 0);
1271
#endif /* __linux__ */
1272
/* Lower privileges */
1280
strcpy(network.ifr_name, interface);
1281
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1283
perror("ioctl SIOCGIFFLAGS");
1285
if(restore_loglevel){
1286
ret = klogctl(7, NULL, 0);
1291
#endif /* __linux__ */
1292
exitcode = EXIT_FAILURE;
1293
/* Lower privileges */
1301
if((network.ifr_flags & IFF_UP) == 0){
1302
network.ifr_flags |= IFF_UP;
1303
take_down_interface = true;
1304
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1306
take_down_interface = false;
1307
perror("ioctl SIOCSIFFLAGS");
1308
exitcode = EXIT_FAILURE;
1310
if(restore_loglevel){
1311
ret = klogctl(7, NULL, 0);
2269
perror_plus("sigaction");
2270
exitcode = EX_OSERR;
2275
/* If no interfaces were specified, make a list */
2276
if(mc.interfaces == NULL){
2277
struct dirent **direntries = NULL;
2278
/* Look for any good interfaces */
2279
ret = scandir(sys_class_net, &direntries, good_interface,
2282
/* Add all found interfaces to interfaces list */
2283
for(int i = 0; i < ret; ++i){
2284
ret_errno = argz_add(&mc.interfaces, &mc.interfaces_size,
2285
direntries[i]->d_name);
2288
perror_plus("argz_add");
2289
free(direntries[i]);
2293
fprintf_plus(stderr, "Will use interface \"%s\"\n",
2294
direntries[i]->d_name);
2296
free(direntries[i]);
2303
fprintf_plus(stderr, "Could not find a network interface\n");
2304
exitcode = EXIT_FAILURE;
2309
/* Bring up interfaces which are down, and remove any "none"s */
2311
char *interface = NULL;
2312
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2314
/* If interface name is "none", stop bringing up interfaces.
2315
Also remove all instances of "none" from the list */
2316
if(strcmp(interface, "none") == 0){
2317
argz_delete(&mc.interfaces, &mc.interfaces_size,
2320
while((interface = argz_next(mc.interfaces,
2321
mc.interfaces_size, interface))){
2322
if(strcmp(interface, "none") == 0){
2323
argz_delete(&mc.interfaces, &mc.interfaces_size,
1316
#endif /* __linux__ */
1317
/* Lower privileges */
1326
/* sleep checking until interface is running */
1327
for(int i=0; i < delay * 4; i++){
1328
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1330
perror("ioctl SIOCGIFFLAGS");
1331
} else if(network.ifr_flags & IFF_RUNNING){
1334
struct timespec sleeptime = { .tv_nsec = 250000000 };
1335
ret = nanosleep(&sleeptime, NULL);
1336
if(ret == -1 and errno != EINTR){
1337
perror("nanosleep");
1340
if(not take_down_interface){
1341
/* We won't need the socket anymore */
1342
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1348
if(restore_loglevel){
1349
/* Restores kernel loglevel to default */
1350
ret = klogctl(7, NULL, 0);
1355
#endif /* __linux__ */
1356
/* Lower privileges */
1358
if(take_down_interface){
1359
/* Lower privileges */
1365
/* Lower privileges permanently */
2330
bool interface_was_up = interface_is_up(interface);
2331
errno = bring_up_interface(interface, delay);
2332
if(not interface_was_up){
2334
perror_plus("Failed to bring up interface");
2336
errno = argz_add(&interfaces_to_take_down,
2337
&interfaces_to_take_down_size,
2340
perror_plus("argz_add");
2345
if(debug and (interfaces_to_take_down == NULL)){
2346
fprintf_plus(stderr, "No interfaces were brought up\n");
2350
/* If we only got one interface, explicitly use only that one */
2351
if(argz_count(mc.interfaces, mc.interfaces_size) == 1){
2353
fprintf_plus(stderr, "Using only interface \"%s\"\n",
2356
if_index = (AvahiIfIndex)if_nametoindex(mc.interfaces);
1377
ret = init_gnutls_global(pubkey, seckey);
2363
ret = init_gnutls_global(pubkey, seckey, &mc);
1379
fprintf(stderr, "init_gnutls_global failed\n");
1380
exitcode = EXIT_FAILURE;
2365
fprintf_plus(stderr, "init_gnutls_global failed\n");
2366
exitcode = EX_UNAVAILABLE;
1383
2369
gnutls_initialized = true;
1545
2563
gpgme_release(mc.ctx);
1548
/* Take down the network interface */
1549
if(take_down_interface){
1550
/* Re-raise priviliges */
1557
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1559
perror("ioctl SIOCGIFFLAGS");
1560
} else if(network.ifr_flags & IFF_UP) {
1561
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1562
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1564
perror("ioctl SIOCSIFFLAGS");
1567
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1571
/* Lower privileges permanently */
1580
/* Removes the temp directory used by GPGME */
1581
if(tempdir_created){
1583
struct dirent *direntry;
1584
d = opendir(tempdir);
1586
if(errno != ENOENT){
1591
direntry = readdir(d);
1592
if(direntry == NULL){
1595
/* Skip "." and ".." */
1596
if(direntry->d_name[0] == '.'
1597
and (direntry->d_name[1] == '\0'
1598
or (direntry->d_name[1] == '.'
1599
and direntry->d_name[2] == '\0'))){
1602
char *fullname = NULL;
1603
ret = asprintf(&fullname, "%s/%s", tempdir,
1609
ret = remove(fullname);
1611
fprintf(stderr, "remove(\"%s\"): %s\n", fullname,
1618
ret = rmdir(tempdir);
1619
if(ret == -1 and errno != ENOENT){
2566
/* Cleans up the circular linked list of Mandos servers the client
2568
if(mc.current_server != NULL){
2569
mc.current_server->prev->next = NULL;
2570
while(mc.current_server != NULL){
2571
server *next = mc.current_server->next;
2573
#pragma GCC diagnostic push
2574
#pragma GCC diagnostic ignored "-Wcast-qual"
2576
free((char *)(mc.current_server->ip));
2578
#pragma GCC diagnostic pop
2580
free(mc.current_server);
2581
mc.current_server = next;
2585
/* Re-raise privileges */
2587
ret_errno = raise_privileges();
2590
perror_plus("Failed to raise privileges");
2593
/* Run network hooks */
2594
run_network_hooks("stop", interfaces_hooks != NULL ?
2595
interfaces_hooks : "", delay);
2597
/* Take down the network interfaces which were brought up */
2599
char *interface = NULL;
2600
while((interface=argz_next(interfaces_to_take_down,
2601
interfaces_to_take_down_size,
2603
ret_errno = take_down_interface(interface);
2606
perror_plus("Failed to take down interface");
2609
if(debug and (interfaces_to_take_down == NULL)){
2610
fprintf_plus(stderr, "No interfaces needed to be taken"
2616
ret_errno = lower_privileges_permanently();
2619
perror_plus("Failed to lower privileges permanently");
2623
free(interfaces_to_take_down);
2624
free(interfaces_hooks);
2626
/* Removes the GPGME temp directory and all files inside */
2627
if(tempdir != NULL){
2628
struct dirent **direntries = NULL;
2629
int tempdir_fd = (int)TEMP_FAILURE_RETRY(open(tempdir, O_RDONLY |
2631
if(tempdir_fd == -1){
2632
perror_plus("open");
2635
#if __GLIBC_PREREQ(2, 15)
2636
int numentries = scandirat(tempdir_fd, ".", &direntries,
2637
notdotentries, alphasort);
2638
#else /* not __GLIBC_PREREQ(2, 15) */
2639
int numentries = scandir(tempdir, &direntries, notdotentries,
2641
#endif /* not __GLIBC_PREREQ(2, 15) */
2642
#else /* not __GLIBC__ */
2643
int numentries = scandir(tempdir, &direntries, notdotentries,
2645
#endif /* not __GLIBC__ */
2646
if(numentries >= 0){
2647
for(int i = 0; i < numentries; i++){
2648
ret = unlinkat(tempdir_fd, direntries[i]->d_name, 0);
2650
fprintf_plus(stderr, "unlinkat(open(\"%s\", O_RDONLY),"
2651
" \"%s\", 0): %s\n", tempdir,
2652
direntries[i]->d_name, strerror(errno));
2654
free(direntries[i]);
2657
/* need to clean even if 0 because man page doesn't specify */
2659
if(numentries == -1){
2660
perror_plus("scandir");
2662
ret = rmdir(tempdir);
2663
if(ret == -1 and errno != ENOENT){
2664
perror_plus("rmdir");
2667
TEMP_FAILURE_RETRY(close(tempdir_fd));