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");
239
ret = clock_gettime(CLOCK_MONOTONIC, &(new_server->last_seen));
241
perror_plus("clock_gettime");
244
/* Special case of first server */
245
if(*current_server == NULL){
246
new_server->next = new_server;
247
new_server->prev = new_server;
248
*current_server = new_server;
250
/* Place the new server last in the list */
251
new_server->next = *current_server;
252
new_server->prev = (*current_server)->prev;
253
new_server->prev->next = new_server;
254
(*current_server)->prev = new_server;
167
260
* Initialize GPGME.
169
static bool init_gpgme(const char *seckey,
170
const char *pubkey, const char *tempdir){
262
__attribute__((nonnull, warn_unused_result))
263
static bool init_gpgme(const char * const seckey,
264
const char * const pubkey,
265
const char * const tempdir,
171
267
gpgme_error_t rc;
172
268
gpgme_engine_info_t engine_info;
176
271
* Helper function to insert pub and seckey to the engine keyring.
178
bool import_key(const char *filename){
273
bool import_key(const char * const filename){
181
276
gpgme_data_t pgp_data;
183
278
fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
189
284
rc = gpgme_data_new_from_fd(&pgp_data, fd);
190
285
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));
286
fprintf_plus(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
287
gpgme_strsource(rc), gpgme_strerror(rc));
196
rc = gpgme_op_import(mc.ctx, pgp_data);
291
rc = gpgme_op_import(mc->ctx, pgp_data);
197
292
if(rc != GPG_ERR_NO_ERROR){
198
fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
199
gpgme_strsource(rc), gpgme_strerror(rc));
293
fprintf_plus(stderr, "bad gpgme_op_import: %s: %s\n",
294
gpgme_strsource(rc), gpgme_strerror(rc));
203
298
ret = (int)TEMP_FAILURE_RETRY(close(fd));
300
perror_plus("close");
207
302
gpgme_data_release(pgp_data);
212
fprintf(stderr, "Initializing GPGME\n");
307
fprintf_plus(stderr, "Initializing GPGME\n");
216
311
gpgme_check_version(NULL);
217
312
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
218
313
if(rc != GPG_ERR_NO_ERROR){
219
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
220
gpgme_strsource(rc), gpgme_strerror(rc));
314
fprintf_plus(stderr, "bad gpgme_engine_check_version: %s: %s\n",
315
gpgme_strsource(rc), gpgme_strerror(rc));
224
/* Set GPGME home directory for the OpenPGP engine only */
319
/* Set GPGME home directory for the OpenPGP engine only */
225
320
rc = gpgme_get_engine_info(&engine_info);
226
321
if(rc != GPG_ERR_NO_ERROR){
227
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
228
gpgme_strsource(rc), gpgme_strerror(rc));
322
fprintf_plus(stderr, "bad gpgme_get_engine_info: %s: %s\n",
323
gpgme_strsource(rc), gpgme_strerror(rc));
231
326
while(engine_info != NULL){
270
369
ssize_t plaintext_length = 0;
273
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
372
fprintf_plus(stderr, "Trying to decrypt OpenPGP data\n");
276
375
/* Create new GPGME data buffer from memory cryptotext */
277
376
rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,
279
378
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));
379
fprintf_plus(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
380
gpgme_strsource(rc), gpgme_strerror(rc));
285
384
/* Create new empty GPGME data buffer for the plaintext */
286
385
rc = gpgme_data_new(&dh_plain);
287
386
if(rc != GPG_ERR_NO_ERROR){
288
fprintf(stderr, "bad gpgme_data_new: %s: %s\n",
289
gpgme_strsource(rc), gpgme_strerror(rc));
387
fprintf_plus(stderr, "Mandos plugin mandos-client: "
388
"bad gpgme_data_new: %s: %s\n",
389
gpgme_strsource(rc), gpgme_strerror(rc));
290
390
gpgme_data_release(dh_crypto);
294
394
/* Decrypt data from the cryptotext data buffer to the plaintext
296
rc = gpgme_op_decrypt(mc.ctx, dh_crypto, dh_plain);
396
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
297
397
if(rc != GPG_ERR_NO_ERROR){
298
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
299
gpgme_strsource(rc), gpgme_strerror(rc));
398
fprintf_plus(stderr, "bad gpgme_op_decrypt: %s: %s\n",
399
gpgme_strsource(rc), gpgme_strerror(rc));
300
400
plaintext_length = -1;
302
402
gpgme_decrypt_result_t result;
303
result = gpgme_op_decrypt_result(mc.ctx);
403
result = gpgme_op_decrypt_result(mc->ctx);
304
404
if(result == NULL){
305
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
405
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);
407
fprintf_plus(stderr, "Unsupported algorithm: %s\n",
408
result->unsupported_algorithm);
409
fprintf_plus(stderr, "Wrong key usage: %u\n",
410
result->wrong_key_usage);
311
411
if(result->file_name != NULL){
312
fprintf(stderr, "File name: %s\n", result->file_name);
412
fprintf_plus(stderr, "File name: %s\n", result->file_name);
314
414
gpgme_recipient_t recipient;
315
415
recipient = result->recipients;
316
416
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
417
fprintf_plus(stderr, "Public key algorithm: %s\n",
418
gpgme_pubkey_algo_name
419
(recipient->pubkey_algo));
420
fprintf_plus(stderr, "Key ID: %s\n", recipient->keyid);
421
fprintf_plus(stderr, "Secret key available: %s\n",
422
recipient->status == GPG_ERR_NO_SECKEY
323
424
recipient = recipient->next;
422
526
/* OpenPGP credentials */
423
gnutls_certificate_allocate_credentials(&mc.cred);
527
ret = gnutls_certificate_allocate_credentials(&mc->cred);
424
528
if(ret != GNUTLS_E_SUCCESS){
425
fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning
429
safer_gnutls_strerror(ret));
529
fprintf_plus(stderr, "GnuTLS memory error: %s\n",
530
safer_gnutls_strerror(ret));
430
531
gnutls_global_deinit();
435
fprintf(stderr, "Attempting to use OpenPGP public key %s and"
436
" secret key %s as GnuTLS credentials\n", pubkeyfilename,
536
fprintf_plus(stderr, "Attempting to use OpenPGP public key %s and"
537
" secret key %s as GnuTLS credentials\n",
440
542
ret = gnutls_certificate_set_openpgp_key_file
441
(mc.cred, pubkeyfilename, seckeyfilename,
543
(mc->cred, pubkeyfilename, seckeyfilename,
442
544
GNUTLS_OPENPGP_FMT_BASE64);
443
545
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));
547
"Error[%d] while reading the OpenPGP key pair ('%s',"
548
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
549
fprintf_plus(stderr, "The GnuTLS error is: %s\n",
550
safer_gnutls_strerror(ret));
452
554
/* GnuTLS server initialization */
453
ret = gnutls_dh_params_init(&mc.dh_params);
555
ret = gnutls_dh_params_init(&mc->dh_params);
454
556
if(ret != GNUTLS_E_SUCCESS){
455
fprintf(stderr, "Error in GnuTLS DH parameter initialization:"
456
" %s\n", safer_gnutls_strerror(ret));
557
fprintf_plus(stderr, "Error in GnuTLS DH parameter"
558
" initialization: %s\n",
559
safer_gnutls_strerror(ret));
459
ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);
562
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
460
563
if(ret != GNUTLS_E_SUCCESS){
461
fprintf(stderr, "Error in GnuTLS prime generation: %s\n",
462
safer_gnutls_strerror(ret));
564
fprintf_plus(stderr, "Error in GnuTLS prime generation: %s\n",
565
safer_gnutls_strerror(ret));
466
gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);
569
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
472
gnutls_certificate_free_credentials(mc.cred);
575
gnutls_certificate_free_credentials(mc->cred);
473
576
gnutls_global_deinit();
474
gnutls_dh_params_deinit(mc.dh_params);
577
gnutls_dh_params_deinit(mc->dh_params);
478
static int init_gnutls_session(gnutls_session_t *session){
581
__attribute__((nonnull, warn_unused_result))
582
static int init_gnutls_session(gnutls_session_t *session,
480
585
/* GnuTLS session creation */
568
fprintf(stderr, "Bad address family: %d\n", af);
675
fprintf_plus(stderr, "Bad address family: %d\n", af);
572
ret = init_gnutls_session(&session);
680
/* If the interface is specified and we have a list of interfaces */
681
if(if_index != AVAHI_IF_UNSPEC and mc->interfaces != NULL){
682
/* Check if the interface is one of the interfaces we are using */
685
char *interface = NULL;
686
while((interface=argz_next(mc->interfaces, mc->interfaces_size,
688
if(if_nametoindex(interface) == (unsigned int)if_index){
695
/* This interface does not match any in the list, so we don't
696
connect to the server */
698
char interface[IF_NAMESIZE];
699
if(if_indextoname((unsigned int)if_index, interface) == NULL){
700
perror_plus("if_indextoname");
702
fprintf_plus(stderr, "Skipping server on non-used interface"
704
if_indextoname((unsigned int)if_index,
712
ret = init_gnutls_session(&session, mc);
578
fprintf(stderr, "Setting up a TCP connection to %s, port %" PRIu16
718
fprintf_plus(stderr, "Setting up a TCP connection to %s, port %"
719
PRIuMAX "\n", ip, (uintmax_t)port);
582
722
tcp_sd = socket(pf, SOCK_STREAM, 0);
725
perror_plus("socket");
592
735
memset(&to, 0, sizeof(to));
593
736
if(af == AF_INET6){
594
to.in6.sin6_family = (sa_family_t)af;
595
ret = inet_pton(af, ip, &to.in6.sin6_addr);
737
((struct sockaddr_in6 *)&to)->sin6_family = (sa_family_t)af;
738
ret = inet_pton(af, ip, &((struct sockaddr_in6 *)&to)->sin6_addr);
596
739
} else { /* IPv4 */
597
to.in.sin_family = (sa_family_t)af;
598
ret = inet_pton(af, ip, &to.in.sin_addr);
740
((struct sockaddr_in *)&to)->sin_family = (sa_family_t)af;
741
ret = inet_pton(af, ip, &((struct sockaddr_in *)&to)->sin_addr);
745
perror_plus("inet_pton");
605
fprintf(stderr, "Bad address: %s\n", ip);
751
fprintf_plus(stderr, "Bad address: %s\n", ip);
608
755
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
756
((struct sockaddr_in6 *)&to)->sin6_port = htons(port);
757
if(IN6_IS_ADDR_LINKLOCAL
758
(&((struct sockaddr_in6 *)&to)->sin6_addr)){
616
759
if(if_index == AVAHI_IF_UNSPEC){
617
fprintf(stderr, "An IPv6 link-local address is incomplete"
618
" without a network interface\n");
760
fprintf_plus(stderr, "An IPv6 link-local address is"
761
" incomplete without a network interface\n");
621
765
/* Set the network interface number as scope */
622
to.in6.sin6_scope_id = (uint32_t)if_index;
766
((struct sockaddr_in6 *)&to)->sin6_scope_id = (uint32_t)if_index;
625
to.in.sin_port = htons(port); /* Spurious warnings from
627
-Wunreachable-code */
769
((struct sockaddr_in *)&to)->sin_port = htons(port);
970
1176
signal_received = sig;
971
1177
int old_errno = errno;
972
if(mc.simple_poll != NULL){
973
avahi_simple_poll_quit(mc.simple_poll);
1178
/* set main loop to exit */
1179
if(simple_poll != NULL){
1180
avahi_simple_poll_quit(simple_poll);
1185
__attribute__((nonnull, warn_unused_result))
1186
bool get_flags(const char *ifname, struct ifreq *ifr){
1190
int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1193
perror_plus("socket");
1197
strcpy(ifr->ifr_name, ifname);
1198
ret = ioctl(s, SIOCGIFFLAGS, ifr);
1202
perror_plus("ioctl SIOCGIFFLAGS");
1210
__attribute__((nonnull, warn_unused_result))
1211
bool good_flags(const char *ifname, const struct ifreq *ifr){
1213
/* Reject the loopback device */
1214
if(ifr->ifr_flags & IFF_LOOPBACK){
1216
fprintf_plus(stderr, "Rejecting loopback interface \"%s\"\n",
1221
/* Accept point-to-point devices only if connect_to is specified */
1222
if(connect_to != NULL and (ifr->ifr_flags & IFF_POINTOPOINT)){
1224
fprintf_plus(stderr, "Accepting point-to-point interface"
1225
" \"%s\"\n", ifname);
1229
/* Otherwise, reject non-broadcast-capable devices */
1230
if(not (ifr->ifr_flags & IFF_BROADCAST)){
1232
fprintf_plus(stderr, "Rejecting non-broadcast interface"
1233
" \"%s\"\n", ifname);
1237
/* Reject non-ARP interfaces (including dummy interfaces) */
1238
if(ifr->ifr_flags & IFF_NOARP){
1240
fprintf_plus(stderr, "Rejecting non-ARP interface \"%s\"\n",
1246
/* Accept this device */
1248
fprintf_plus(stderr, "Interface \"%s\" is good\n", ifname);
1254
* This function determines if a directory entry in /sys/class/net
1255
* corresponds to an acceptable network device.
1256
* (This function is passed to scandir(3) as a filter function.)
1258
__attribute__((nonnull, warn_unused_result))
1259
int good_interface(const struct dirent *if_entry){
1260
if(if_entry->d_name[0] == '.'){
1265
if(not get_flags(if_entry->d_name, &ifr)){
1267
fprintf_plus(stderr, "Failed to get flags for interface "
1268
"\"%s\"\n", if_entry->d_name);
1273
if(not good_flags(if_entry->d_name, &ifr)){
1280
* This function determines if a network interface is up.
1282
__attribute__((nonnull, warn_unused_result))
1283
bool interface_is_up(const char *interface){
1285
if(not get_flags(interface, &ifr)){
1287
fprintf_plus(stderr, "Failed to get flags for interface "
1288
"\"%s\"\n", interface);
1293
return (bool)(ifr.ifr_flags & IFF_UP);
1297
* This function determines if a network interface is running
1299
__attribute__((nonnull, warn_unused_result))
1300
bool interface_is_running(const char *interface){
1302
if(not get_flags(interface, &ifr)){
1304
fprintf_plus(stderr, "Failed to get flags for interface "
1305
"\"%s\"\n", interface);
1310
return (bool)(ifr.ifr_flags & IFF_RUNNING);
1313
__attribute__((nonnull, pure, warn_unused_result))
1314
int notdotentries(const struct dirent *direntry){
1315
/* Skip "." and ".." */
1316
if(direntry->d_name[0] == '.'
1317
and (direntry->d_name[1] == '\0'
1318
or (direntry->d_name[1] == '.'
1319
and direntry->d_name[2] == '\0'))){
1325
/* Is this directory entry a runnable program? */
1326
__attribute__((nonnull, warn_unused_result))
1327
int runnable_hook(const struct dirent *direntry){
1332
if((direntry->d_name)[0] == '\0'){
1337
sret = strspn(direntry->d_name, "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
1338
"abcdefghijklmnopqrstuvwxyz"
1341
if((direntry->d_name)[sret] != '\0'){
1342
/* Contains non-allowed characters */
1344
fprintf_plus(stderr, "Ignoring hook \"%s\" with bad name\n",
1350
ret = fstatat(hookdir_fd, direntry->d_name, &st, 0);
1353
perror_plus("Could not stat hook");
1357
if(not (S_ISREG(st.st_mode))){
1358
/* Not a regular file */
1360
fprintf_plus(stderr, "Ignoring hook \"%s\" - not a file\n",
1365
if(not (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))){
1366
/* Not executable */
1368
fprintf_plus(stderr, "Ignoring hook \"%s\" - not executable\n",
1374
fprintf_plus(stderr, "Hook \"%s\" is acceptable\n",
1380
__attribute__((nonnull, warn_unused_result))
1381
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,
1382
mandos_context *mc){
1384
struct timespec now;
1385
struct timespec waited_time;
1386
intmax_t block_time;
1389
if(mc->current_server == NULL){
1391
fprintf_plus(stderr, "Wait until first server is found."
1394
ret = avahi_simple_poll_iterate(s, -1);
1397
fprintf_plus(stderr, "Check current_server if we should run"
1400
/* the current time */
1401
ret = clock_gettime(CLOCK_MONOTONIC, &now);
1403
perror_plus("clock_gettime");
1406
/* Calculating in ms how long time between now and server
1407
who we visted longest time ago. Now - last seen. */
1408
waited_time.tv_sec = (now.tv_sec
1409
- mc->current_server->last_seen.tv_sec);
1410
waited_time.tv_nsec = (now.tv_nsec
1411
- mc->current_server->last_seen.tv_nsec);
1412
/* total time is 10s/10,000ms.
1413
Converting to s from ms by dividing by 1,000,
1414
and ns to ms by dividing by 1,000,000. */
1415
block_time = ((retry_interval
1416
- ((intmax_t)waited_time.tv_sec * 1000))
1417
- ((intmax_t)waited_time.tv_nsec / 1000000));
1420
fprintf_plus(stderr, "Blocking for %" PRIdMAX " ms\n",
1424
if(block_time <= 0){
1425
ret = start_mandos_communication(mc->current_server->ip,
1426
mc->current_server->port,
1427
mc->current_server->if_index,
1428
mc->current_server->af, mc);
1430
avahi_simple_poll_quit(s);
1433
ret = clock_gettime(CLOCK_MONOTONIC,
1434
&mc->current_server->last_seen);
1436
perror_plus("clock_gettime");
1439
mc->current_server = mc->current_server->next;
1440
block_time = 0; /* Call avahi to find new Mandos
1441
servers, but don't block */
1444
ret = avahi_simple_poll_iterate(s, (int)block_time);
1447
if(ret > 0 or errno != EINTR){
1448
return (ret != 1) ? ret : 0;
1454
/* Set effective uid to 0, return errno */
1455
__attribute__((warn_unused_result))
1456
error_t raise_privileges(void){
1457
error_t old_errno = errno;
1458
error_t ret_errno = 0;
1459
if(seteuid(0) == -1){
1461
perror_plus("seteuid");
1467
/* Set effective and real user ID to 0. Return errno. */
1468
__attribute__((warn_unused_result))
1469
error_t raise_privileges_permanently(void){
1470
error_t old_errno = errno;
1471
error_t ret_errno = raise_privileges();
1476
if(setuid(0) == -1){
1478
perror_plus("seteuid");
1484
/* Set effective user ID to unprivileged saved user ID */
1485
__attribute__((warn_unused_result))
1486
error_t lower_privileges(void){
1487
error_t old_errno = errno;
1488
error_t ret_errno = 0;
1489
if(seteuid(uid) == -1){
1491
perror_plus("seteuid");
1497
/* Lower privileges permanently */
1498
__attribute__((warn_unused_result))
1499
error_t lower_privileges_permanently(void){
1500
error_t old_errno = errno;
1501
error_t ret_errno = 0;
1502
if(setuid(uid) == -1){
1504
perror_plus("setuid");
1510
__attribute__((nonnull))
1511
void run_network_hooks(const char *mode, const char *interface,
1513
struct dirent **direntries;
1514
if(hookdir_fd == -1){
1515
hookdir_fd = open(hookdir, O_RDONLY);
1516
if(hookdir_fd == -1){
1517
if(errno == ENOENT){
1519
fprintf_plus(stderr, "Network hook directory \"%s\" not"
1520
" found\n", hookdir);
1523
perror_plus("open");
1529
#if __GLIBC_PREREQ(2, 15)
1530
int numhooks = scandirat(hookdir_fd, ".", &direntries,
1531
runnable_hook, alphasort);
1532
#else /* not __GLIBC_PREREQ(2, 15) */
1533
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1535
#endif /* not __GLIBC_PREREQ(2, 15) */
1536
#else /* not __GLIBC__ */
1537
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1539
#endif /* not __GLIBC__ */
1541
perror_plus("scandir");
1544
struct dirent *direntry;
1546
int devnull = open("/dev/null", O_RDONLY);
1547
for(int i = 0; i < numhooks; i++){
1548
direntry = direntries[i];
1550
fprintf_plus(stderr, "Running network hook \"%s\"\n",
1553
pid_t hook_pid = fork();
1556
/* Raise privileges */
1557
if(raise_privileges_permanently() != 0){
1558
perror_plus("Failed to raise privileges");
1565
perror_plus("setgid");
1568
/* Reset supplementary groups */
1570
ret = setgroups(0, NULL);
1572
perror_plus("setgroups");
1575
ret = dup2(devnull, STDIN_FILENO);
1577
perror_plus("dup2(devnull, STDIN_FILENO)");
1580
ret = close(devnull);
1582
perror_plus("close");
1585
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
1587
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
1590
ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);
1592
perror_plus("setenv");
1595
ret = setenv("DEVICE", interface, 1);
1597
perror_plus("setenv");
1600
ret = setenv("VERBOSITY", debug ? "1" : "0", 1);
1602
perror_plus("setenv");
1605
ret = setenv("MODE", mode, 1);
1607
perror_plus("setenv");
1611
ret = asprintf(&delaystring, "%f", (double)delay);
1613
perror_plus("asprintf");
1616
ret = setenv("DELAY", delaystring, 1);
1619
perror_plus("setenv");
1623
if(connect_to != NULL){
1624
ret = setenv("CONNECT", connect_to, 1);
1626
perror_plus("setenv");
1630
int hook_fd = openat(hookdir_fd, direntry->d_name, O_RDONLY);
1632
perror_plus("openat");
1633
_exit(EXIT_FAILURE);
1635
if((int)TEMP_FAILURE_RETRY(close(hookdir_fd)) == -1){
1636
perror_plus("close");
1637
_exit(EXIT_FAILURE);
1639
if(fexecve(hook_fd, (char *const []){ direntry->d_name, NULL },
1641
perror_plus("fexecve");
1642
_exit(EXIT_FAILURE);
1646
if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){
1647
perror_plus("waitpid");
1650
if(WIFEXITED(status)){
1651
if(WEXITSTATUS(status) != 0){
1652
fprintf_plus(stderr, "Warning: network hook \"%s\" exited"
1653
" with status %d\n", direntry->d_name,
1654
WEXITSTATUS(status));
1657
} else if(WIFSIGNALED(status)){
1658
fprintf_plus(stderr, "Warning: network hook \"%s\" died by"
1659
" signal %d\n", direntry->d_name,
1663
fprintf_plus(stderr, "Warning: network hook \"%s\""
1664
" crashed\n", direntry->d_name);
1669
fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",
1673
if((int)TEMP_FAILURE_RETRY(close(hookdir_fd)) == -1){
1674
perror_plus("close");
1681
__attribute__((nonnull, warn_unused_result))
1682
error_t bring_up_interface(const char *const interface,
1684
error_t old_errno = errno;
1686
struct ifreq network;
1687
unsigned int if_index = if_nametoindex(interface);
1689
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1699
if(not interface_is_up(interface)){
1700
error_t ret_errno = 0, ioctl_errno = 0;
1701
if(not get_flags(interface, &network)){
1703
fprintf_plus(stderr, "Failed to get flags for interface "
1704
"\"%s\"\n", interface);
1708
network.ifr_flags |= IFF_UP; /* set flag */
1710
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1713
perror_plus("socket");
1719
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1721
perror_plus("close");
1728
fprintf_plus(stderr, "Bringing up interface \"%s\"\n",
1732
/* Raise privileges */
1733
ret_errno = raise_privileges();
1735
perror_plus("Failed to raise privileges");
1740
bool restore_loglevel = false;
1742
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1743
messages about the network interface to mess up the prompt */
1744
ret_linux = klogctl(8, NULL, 5);
1745
if(ret_linux == -1){
1746
perror_plus("klogctl");
1748
restore_loglevel = true;
1751
#endif /* __linux__ */
1752
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1753
ioctl_errno = errno;
1755
if(restore_loglevel){
1756
ret_linux = klogctl(7, NULL, 0);
1757
if(ret_linux == -1){
1758
perror_plus("klogctl");
1761
#endif /* __linux__ */
1763
/* If raise_privileges() succeeded above */
1765
/* Lower privileges */
1766
ret_errno = lower_privileges();
1769
perror_plus("Failed to lower privileges");
1773
/* Close the socket */
1774
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1776
perror_plus("close");
1779
if(ret_setflags == -1){
1780
errno = ioctl_errno;
1781
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1786
fprintf_plus(stderr, "Interface \"%s\" is already up; good\n",
1790
/* Sleep checking until interface is running.
1791
Check every 0.25s, up to total time of delay */
1792
for(int i=0; i < delay * 4; i++){
1793
if(interface_is_running(interface)){
1796
struct timespec sleeptime = { .tv_nsec = 250000000 };
1797
ret = nanosleep(&sleeptime, NULL);
1798
if(ret == -1 and errno != EINTR){
1799
perror_plus("nanosleep");
1807
__attribute__((nonnull, warn_unused_result))
1808
error_t take_down_interface(const char *const interface){
1809
error_t old_errno = errno;
1810
struct ifreq network;
1811
unsigned int if_index = if_nametoindex(interface);
1813
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1817
if(interface_is_up(interface)){
1818
error_t ret_errno = 0, ioctl_errno = 0;
1819
if(not get_flags(interface, &network) and debug){
1821
fprintf_plus(stderr, "Failed to get flags for interface "
1822
"\"%s\"\n", interface);
1826
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1828
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1831
perror_plus("socket");
1837
fprintf_plus(stderr, "Taking down interface \"%s\"\n",
1841
/* Raise privileges */
1842
ret_errno = raise_privileges();
1844
perror_plus("Failed to raise privileges");
1847
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1848
ioctl_errno = errno;
1850
/* If raise_privileges() succeeded above */
1852
/* Lower privileges */
1853
ret_errno = lower_privileges();
1856
perror_plus("Failed to lower privileges");
1860
/* Close the socket */
1861
int ret = (int)TEMP_FAILURE_RETRY(close(sd));
1863
perror_plus("close");
1866
if(ret_setflags == -1){
1867
errno = ioctl_errno;
1868
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
1873
fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",
978
1881
int main(int argc, char *argv[]){
1882
mandos_context mc = { .server = NULL, .dh_bits = 1024,
1883
.priority = "SECURE256:!CTYPE-X.509:"
1884
"+CTYPE-OPENPGP", .current_server = NULL,
1885
.interfaces = NULL, .interfaces_size = 0 };
979
1886
AvahiSServiceBrowser *sb = NULL;
982
1889
intmax_t tmpmax;
984
1891
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;
1892
char *interfaces_to_take_down = NULL;
1893
size_t interfaces_to_take_down_size = 0;
1894
char run_tempdir[] = "/run/tmp/mandosXXXXXX";
1895
char old_tempdir[] = "/tmp/mandosXXXXXX";
1896
char *tempdir = NULL;
994
1897
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
995
1898
const char *seckey = PATHDIR "/" SECKEY;
996
1899
const char *pubkey = PATHDIR "/" PUBKEY;
1900
char *interfaces_hooks = NULL;
998
1902
bool gnutls_initialized = false;
999
1903
bool gpgme_initialized = false;
1000
1904
float delay = 2.5f;
1905
double retry_interval = 10; /* 10s between trying a server and
1906
retrying the same server again */
1002
1908
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
1003
1909
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
1189
2214
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1191
perror("sigaction");
1192
return EXIT_FAILURE;
2216
perror_plus("sigaction");
1194
2219
if(old_sigterm_action.sa_handler != SIG_IGN){
1195
2220
ret = sigaction(SIGINT, &sigterm_action, NULL);
1197
perror("sigaction");
1198
exitcode = EXIT_FAILURE;
2222
perror_plus("sigaction");
2223
exitcode = EX_OSERR;
1202
2227
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1204
perror("sigaction");
1205
return EXIT_FAILURE;
2229
perror_plus("sigaction");
1207
2232
if(old_sigterm_action.sa_handler != SIG_IGN){
1208
2233
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1210
perror("sigaction");
1211
exitcode = EXIT_FAILURE;
2235
perror_plus("sigaction");
2236
exitcode = EX_OSERR;
1215
2240
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1217
perror("sigaction");
1218
return EXIT_FAILURE;
2242
perror_plus("sigaction");
1220
2245
if(old_sigterm_action.sa_handler != SIG_IGN){
1221
2246
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);
2248
perror_plus("sigaction");
2249
exitcode = EX_OSERR;
2254
/* If no interfaces were specified, make a list */
2255
if(mc.interfaces == NULL){
2256
struct dirent **direntries = NULL;
2257
/* Look for any good interfaces */
2258
ret = scandir(sys_class_net, &direntries, good_interface,
2261
/* Add all found interfaces to interfaces list */
2262
for(int i = 0; i < ret; ++i){
2263
ret_errno = argz_add(&mc.interfaces, &mc.interfaces_size,
2264
direntries[i]->d_name);
2267
perror_plus("argz_add");
2271
fprintf_plus(stderr, "Will use interface \"%s\"\n",
2272
direntries[i]->d_name);
2278
fprintf_plus(stderr, "Could not find a network interface\n");
2279
exitcode = EXIT_FAILURE;
2284
/* Bring up interfaces which are down, and remove any "none"s */
2286
char *interface = NULL;
2287
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2289
/* If interface name is "none", stop bringing up interfaces.
2290
Also remove all instances of "none" from the list */
2291
if(strcmp(interface, "none") == 0){
2292
argz_delete(&mc.interfaces, &mc.interfaces_size,
2295
while((interface = argz_next(mc.interfaces,
2296
mc.interfaces_size, interface))){
2297
if(strcmp(interface, "none") == 0){
2298
argz_delete(&mc.interfaces, &mc.interfaces_size,
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 */
2305
bool interface_was_up = interface_is_up(interface);
2306
errno = bring_up_interface(interface, delay);
2307
if(not interface_was_up){
2309
perror_plus("Failed to bring up interface");
2311
errno = argz_add(&interfaces_to_take_down,
2312
&interfaces_to_take_down_size,
2315
perror_plus("argz_add");
2320
if(debug and (interfaces_to_take_down == NULL)){
2321
fprintf_plus(stderr, "No interfaces were brought up\n");
2325
/* If we only got one interface, explicitly use only that one */
2326
if(argz_count(mc.interfaces, mc.interfaces_size) == 1){
2328
fprintf_plus(stderr, "Using only interface \"%s\"\n",
2331
if_index = (AvahiIfIndex)if_nametoindex(mc.interfaces);
1377
ret = init_gnutls_global(pubkey, seckey);
2338
ret = init_gnutls_global(pubkey, seckey, &mc);
1379
fprintf(stderr, "init_gnutls_global failed\n");
1380
exitcode = EXIT_FAILURE;
2340
fprintf_plus(stderr, "init_gnutls_global failed\n");
2341
exitcode = EX_UNAVAILABLE;
1383
2344
gnutls_initialized = true;
1545
2538
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){
2541
/* Cleans up the circular linked list of Mandos servers the client
2543
if(mc.current_server != NULL){
2544
mc.current_server->prev->next = NULL;
2545
while(mc.current_server != NULL){
2546
server *next = mc.current_server->next;
2547
free(mc.current_server);
2548
mc.current_server = next;
2552
/* Re-raise privileges */
2554
ret_errno = raise_privileges();
2556
perror_plus("Failed to raise privileges");
2559
/* Run network hooks */
2560
run_network_hooks("stop", interfaces_hooks != NULL ?
2561
interfaces_hooks : "", delay);
2563
/* Take down the network interfaces which were brought up */
2565
char *interface = NULL;
2566
while((interface=argz_next(interfaces_to_take_down,
2567
interfaces_to_take_down_size,
2569
ret_errno = take_down_interface(interface);
2572
perror_plus("Failed to take down interface");
2575
if(debug and (interfaces_to_take_down == NULL)){
2576
fprintf_plus(stderr, "No interfaces needed to be taken"
2582
ret_errno = lower_privileges_permanently();
2584
perror_plus("Failed to lower privileges permanently");
2588
free(interfaces_to_take_down);
2589
free(interfaces_hooks);
2591
/* Removes the GPGME temp directory and all files inside */
2592
if(tempdir != NULL){
2593
struct dirent **direntries = NULL;
2594
int tempdir_fd = (int)TEMP_FAILURE_RETRY(open(tempdir, O_RDONLY |
2596
if(tempdir_fd == -1){
2597
perror_plus("open");
2600
#if __GLIBC_PREREQ(2, 15)
2601
int numentries = scandirat(tempdir_fd, ".", &direntries,
2602
notdotentries, alphasort);
2603
#else /* not __GLIBC_PREREQ(2, 15) */
2604
int numentries = scandir(tempdir, &direntries, notdotentries,
2606
#endif /* not __GLIBC_PREREQ(2, 15) */
2607
#else /* not __GLIBC__ */
2608
int numentries = scandir(tempdir, &direntries, notdotentries,
2610
#endif /* not __GLIBC__ */
2612
for(int i = 0; i < numentries; i++){
2613
ret = unlinkat(tempdir_fd, direntries[i]->d_name, 0);
2615
fprintf_plus(stderr, "unlinkat(open(\"%s\", O_RDONLY),"
2616
" \"%s\", 0): %s\n", tempdir,
2617
direntries[i]->d_name, strerror(errno));
2621
/* need to clean even if 0 because man page doesn't specify */
2623
if(numentries == -1){
2624
perror_plus("scandir");
2626
ret = rmdir(tempdir);
2627
if(ret == -1 and errno != ENOENT){
2628
perror_plus("rmdir");
2631
TEMP_FAILURE_RETRY(close(tempdir_fd));