122
133
#define PATHDIR "/conf/conf.d/mandos"
123
134
#define SECKEY "seckey.txt"
124
135
#define PUBKEY "pubkey.txt"
136
#define HOOKDIR "/lib/mandos/network-hooks.d"
126
138
bool debug = false;
127
139
static const char mandos_protocol_version[] = "1";
128
140
const char *argp_program_version = "mandos-client " VERSION;
129
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
141
const char *argp_program_bug_address = "<mandos@recompile.se>";
130
142
static const char sys_class_net[] = "/sys/class/net";
131
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;
133
160
/* Used for passing in values through the Avahi callback functions */
135
AvahiSimplePoll *simple_poll;
136
162
AvahiServer *server;
137
163
gnutls_certificate_credentials_t cred;
138
164
unsigned int dh_bits;
139
165
gnutls_dh_params_t dh_params;
140
166
const char *priority;
168
server *current_server;
170
size_t interfaces_size;
142
171
} mandos_context;
144
/* global context so signal handler can reach it*/
145
mandos_context mc = { .simple_poll = NULL, .server = NULL,
146
.dh_bits = 1024, .priority = "SECURE256"
147
":!CTYPE-X.509:+CTYPE-OPENPGP" };
173
/* global so signal handler can reach it*/
174
AvahiSimplePoll *simple_poll;
149
176
sig_atomic_t quit_now = 0;
150
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));
153
199
* Make additional room in "buffer" for at least BUFFER_SIZE more
154
200
* bytes. "buffer_capacity" is how much is currently allocated,
155
201
* "buffer_length" is how much is already used.
203
__attribute__((nonnull, warn_unused_result))
157
204
size_t incbuffer(char **buffer, size_t buffer_length,
158
size_t buffer_capacity){
205
size_t buffer_capacity){
159
206
if(buffer_length + BUFFER_SIZE > buffer_capacity){
160
*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
207
char *new_buf = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
209
int old_errno = errno;
164
216
buffer_capacity += BUFFER_SIZE;
166
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;
170
270
* Initialize GPGME.
172
static bool init_gpgme(const char *seckey,
173
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,
174
277
gpgme_error_t rc;
175
278
gpgme_engine_info_t engine_info;
179
281
* Helper function to insert pub and seckey to the engine keyring.
181
bool import_key(const char *filename){
283
bool import_key(const char * const filename){
184
286
gpgme_data_t pgp_data;
186
288
fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
192
294
rc = gpgme_data_new_from_fd(&pgp_data, fd);
193
295
if(rc != GPG_ERR_NO_ERROR){
194
fprintf(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
195
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));
199
rc = gpgme_op_import(mc.ctx, pgp_data);
301
rc = gpgme_op_import(mc->ctx, pgp_data);
200
302
if(rc != GPG_ERR_NO_ERROR){
201
fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
202
gpgme_strsource(rc), gpgme_strerror(rc));
303
fprintf_plus(stderr, "bad gpgme_op_import: %s: %s\n",
304
gpgme_strsource(rc), gpgme_strerror(rc));
206
308
ret = (int)TEMP_FAILURE_RETRY(close(fd));
310
perror_plus("close");
210
312
gpgme_data_release(pgp_data);
215
fprintf(stderr, "Initializing GPGME\n");
317
fprintf_plus(stderr, "Initializing GPGME\n");
219
321
gpgme_check_version(NULL);
220
322
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
221
323
if(rc != GPG_ERR_NO_ERROR){
222
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
223
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));
227
/* Set GPGME home directory for the OpenPGP engine only */
329
/* Set GPGME home directory for the OpenPGP engine only */
228
330
rc = gpgme_get_engine_info(&engine_info);
229
331
if(rc != GPG_ERR_NO_ERROR){
230
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
231
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));
234
336
while(engine_info != NULL){
273
379
ssize_t plaintext_length = 0;
276
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
382
fprintf_plus(stderr, "Trying to decrypt OpenPGP data\n");
279
385
/* Create new GPGME data buffer from memory cryptotext */
280
386
rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,
282
388
if(rc != GPG_ERR_NO_ERROR){
283
fprintf(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
284
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));
288
394
/* Create new empty GPGME data buffer for the plaintext */
289
395
rc = gpgme_data_new(&dh_plain);
290
396
if(rc != GPG_ERR_NO_ERROR){
291
fprintf(stderr, "bad gpgme_data_new: %s: %s\n",
292
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));
293
400
gpgme_data_release(dh_crypto);
297
404
/* Decrypt data from the cryptotext data buffer to the plaintext
299
rc = gpgme_op_decrypt(mc.ctx, dh_crypto, dh_plain);
406
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
300
407
if(rc != GPG_ERR_NO_ERROR){
301
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
302
gpgme_strsource(rc), gpgme_strerror(rc));
408
fprintf_plus(stderr, "bad gpgme_op_decrypt: %s: %s\n",
409
gpgme_strsource(rc), gpgme_strerror(rc));
303
410
plaintext_length = -1;
305
412
gpgme_decrypt_result_t result;
306
result = gpgme_op_decrypt_result(mc.ctx);
413
result = gpgme_op_decrypt_result(mc->ctx);
307
414
if(result == NULL){
308
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
415
fprintf_plus(stderr, "gpgme_op_decrypt_result failed\n");
310
fprintf(stderr, "Unsupported algorithm: %s\n",
311
result->unsupported_algorithm);
312
fprintf(stderr, "Wrong key usage: %u\n",
313
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);
314
421
if(result->file_name != NULL){
315
fprintf(stderr, "File name: %s\n", result->file_name);
422
fprintf_plus(stderr, "File name: %s\n", result->file_name);
317
424
gpgme_recipient_t recipient;
318
425
recipient = result->recipients;
319
426
while(recipient != NULL){
320
fprintf(stderr, "Public key algorithm: %s\n",
321
gpgme_pubkey_algo_name(recipient->pubkey_algo));
322
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
323
fprintf(stderr, "Secret key available: %s\n",
324
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
326
434
recipient = recipient->next;
425
542
/* OpenPGP credentials */
426
gnutls_certificate_allocate_credentials(&mc.cred);
543
ret = gnutls_certificate_allocate_credentials(&mc->cred);
427
544
if(ret != GNUTLS_E_SUCCESS){
428
fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning
432
safer_gnutls_strerror(ret));
545
fprintf_plus(stderr, "GnuTLS memory error: %s\n",
546
safer_gnutls_strerror(ret));
433
547
gnutls_global_deinit();
438
fprintf(stderr, "Attempting to use OpenPGP public key %s and"
439
" secret key %s as GnuTLS credentials\n", pubkeyfilename,
552
fprintf_plus(stderr, "Attempting to use OpenPGP public key %s and"
553
" secret key %s as GnuTLS credentials\n",
443
558
ret = gnutls_certificate_set_openpgp_key_file
444
(mc.cred, pubkeyfilename, seckeyfilename,
559
(mc->cred, pubkeyfilename, seckeyfilename,
445
560
GNUTLS_OPENPGP_FMT_BASE64);
446
561
if(ret != GNUTLS_E_SUCCESS){
448
"Error[%d] while reading the OpenPGP key pair ('%s',"
449
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
450
fprintf(stderr, "The GnuTLS error is: %s\n",
451
safer_gnutls_strerror(ret));
563
"Error[%d] while reading the OpenPGP key pair ('%s',"
564
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
565
fprintf_plus(stderr, "The GnuTLS error is: %s\n",
566
safer_gnutls_strerror(ret));
455
570
/* GnuTLS server initialization */
456
ret = gnutls_dh_params_init(&mc.dh_params);
571
ret = gnutls_dh_params_init(&mc->dh_params);
457
572
if(ret != GNUTLS_E_SUCCESS){
458
fprintf(stderr, "Error in GnuTLS DH parameter initialization:"
459
" %s\n", safer_gnutls_strerror(ret));
573
fprintf_plus(stderr, "Error in GnuTLS DH parameter"
574
" initialization: %s\n",
575
safer_gnutls_strerror(ret));
462
ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);
578
if(mc->dh_bits == 0){
579
/* Find out the optimal number of DH bits */
580
/* Try to read the private key file */
581
gnutls_datum_t buffer = { .data = NULL, .size = 0 };
583
int secfile = open(seckeyfilename, O_RDONLY);
584
size_t buffer_capacity = 0;
586
buffer_capacity = incbuffer((char **)&buffer.data,
588
(size_t)buffer_capacity);
589
if(buffer_capacity == 0){
590
perror_plus("incbuffer");
595
ssize_t bytes_read = read(secfile, buffer.data + buffer.size,
601
/* check bytes_read for failure */
608
buffer.size += (unsigned int)bytes_read;
612
/* If successful, use buffer to parse private key */
613
gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;
614
if(buffer.data != NULL){
616
gnutls_openpgp_privkey_t privkey = NULL;
617
ret = gnutls_openpgp_privkey_init(&privkey);
618
if(ret != GNUTLS_E_SUCCESS){
619
fprintf_plus(stderr, "Error initializing OpenPGP key"
620
" structure: %s", safer_gnutls_strerror(ret));
624
ret = gnutls_openpgp_privkey_import(privkey, &buffer,
625
GNUTLS_OPENPGP_FMT_BASE64,
627
if(ret != GNUTLS_E_SUCCESS){
628
fprintf_plus(stderr, "Error importing OpenPGP key : %s",
629
safer_gnutls_strerror(ret));
635
/* Use private key to suggest an appropriate sec_param */
636
sec_param = gnutls_openpgp_privkey_sec_param(privkey);
637
gnutls_openpgp_privkey_deinit(privkey);
639
fprintf_plus(stderr, "This OpenPGP key implies using a"
640
" GnuTLS security parameter \"%s\".\n",
641
safe_string(gnutls_sec_param_get_name
647
if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){
648
/* Err on the side of caution */
649
sec_param = GNUTLS_SEC_PARAM_ULTRA;
651
fprintf_plus(stderr, "Falling back to security parameter"
653
safe_string(gnutls_sec_param_get_name
658
uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);
662
fprintf_plus(stderr, "A \"%s\" GnuTLS security parameter"
663
" implies %u DH bits; using that.\n",
664
safe_string(gnutls_sec_param_get_name
669
fprintf_plus(stderr, "Failed to get implied number of DH"
670
" bits for security parameter \"%s\"): %s\n",
671
safe_string(gnutls_sec_param_get_name(sec_param)),
672
safer_gnutls_strerror(ret));
676
fprintf_plus(stderr, "DH bits explicitly set to %u\n",
679
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
463
680
if(ret != GNUTLS_E_SUCCESS){
464
fprintf(stderr, "Error in GnuTLS prime generation: %s\n",
465
safer_gnutls_strerror(ret));
681
fprintf_plus(stderr, "Error in GnuTLS prime generation (%u bits):"
682
" %s\n", mc->dh_bits, safer_gnutls_strerror(ret));
469
gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);
686
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
475
gnutls_certificate_free_credentials(mc.cred);
692
gnutls_certificate_free_credentials(mc->cred);
476
693
gnutls_global_deinit();
477
gnutls_dh_params_deinit(mc.dh_params);
694
gnutls_dh_params_deinit(mc->dh_params);
481
static int init_gnutls_session(gnutls_session_t *session){
698
__attribute__((nonnull, warn_unused_result))
699
static int init_gnutls_session(gnutls_session_t *session,
483
702
/* GnuTLS session creation */
1017
1294
signal_received = sig;
1018
1295
int old_errno = errno;
1019
if(mc.simple_poll != NULL){
1020
avahi_simple_poll_quit(mc.simple_poll);
1296
/* set main loop to exit */
1297
if(simple_poll != NULL){
1298
avahi_simple_poll_quit(simple_poll);
1022
1300
errno = old_errno;
1303
__attribute__((nonnull, warn_unused_result))
1304
bool get_flags(const char *ifname, struct ifreq *ifr){
1308
int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1311
perror_plus("socket");
1315
strcpy(ifr->ifr_name, ifname);
1316
ret = ioctl(s, SIOCGIFFLAGS, ifr);
1320
perror_plus("ioctl SIOCGIFFLAGS");
1328
__attribute__((nonnull, warn_unused_result))
1329
bool good_flags(const char *ifname, const struct ifreq *ifr){
1331
/* Reject the loopback device */
1332
if(ifr->ifr_flags & IFF_LOOPBACK){
1334
fprintf_plus(stderr, "Rejecting loopback interface \"%s\"\n",
1339
/* Accept point-to-point devices only if connect_to is specified */
1340
if(connect_to != NULL and (ifr->ifr_flags & IFF_POINTOPOINT)){
1342
fprintf_plus(stderr, "Accepting point-to-point interface"
1343
" \"%s\"\n", ifname);
1347
/* Otherwise, reject non-broadcast-capable devices */
1348
if(not (ifr->ifr_flags & IFF_BROADCAST)){
1350
fprintf_plus(stderr, "Rejecting non-broadcast interface"
1351
" \"%s\"\n", ifname);
1355
/* Reject non-ARP interfaces (including dummy interfaces) */
1356
if(ifr->ifr_flags & IFF_NOARP){
1358
fprintf_plus(stderr, "Rejecting non-ARP interface \"%s\"\n",
1364
/* Accept this device */
1366
fprintf_plus(stderr, "Interface \"%s\" is good\n", ifname);
1026
1372
* This function determines if a directory entry in /sys/class/net
1027
1373
* corresponds to an acceptable network device.
1028
1374
* (This function is passed to scandir(3) as a filter function.)
1376
__attribute__((nonnull, warn_unused_result))
1030
1377
int good_interface(const struct dirent *if_entry){
1032
char *flagname = NULL;
1033
int ret = asprintf(&flagname, "%s/%s/flags", sys_class_net,
1039
1378
if(if_entry->d_name[0] == '.'){
1042
int flags_fd = (int)TEMP_FAILURE_RETRY(open(flagname, O_RDONLY));
1047
typedef short ifreq_flags; /* ifreq.ifr_flags in netdevice(7) */
1048
/* read line from flags_fd */
1049
ssize_t to_read = (sizeof(ifreq_flags)*2)+3; /* "0x1003\n" */
1050
char *flagstring = malloc((size_t)to_read+1); /* +1 for final \0 */
1051
flagstring[(size_t)to_read] = '\0';
1052
if(flagstring == NULL){
1058
ssret = (ssize_t)TEMP_FAILURE_RETRY(read(flags_fd, flagstring,
1383
if(not get_flags(if_entry->d_name, &ifr)){
1385
fprintf_plus(stderr, "Failed to get flags for interface "
1386
"\"%s\"\n", if_entry->d_name);
1391
if(not good_flags(if_entry->d_name, &ifr)){
1398
* This function determines if a network interface is up.
1400
__attribute__((nonnull, warn_unused_result))
1401
bool interface_is_up(const char *interface){
1403
if(not get_flags(interface, &ifr)){
1405
fprintf_plus(stderr, "Failed to get flags for interface "
1406
"\"%s\"\n", interface);
1411
return (bool)(ifr.ifr_flags & IFF_UP);
1415
* This function determines if a network interface is running
1417
__attribute__((nonnull, warn_unused_result))
1418
bool interface_is_running(const char *interface){
1420
if(not get_flags(interface, &ifr)){
1422
fprintf_plus(stderr, "Failed to get flags for interface "
1423
"\"%s\"\n", interface);
1428
return (bool)(ifr.ifr_flags & IFF_RUNNING);
1431
__attribute__((nonnull, pure, warn_unused_result))
1432
int notdotentries(const struct dirent *direntry){
1433
/* Skip "." and ".." */
1434
if(direntry->d_name[0] == '.'
1435
and (direntry->d_name[1] == '\0'
1436
or (direntry->d_name[1] == '.'
1437
and direntry->d_name[2] == '\0'))){
1443
/* Is this directory entry a runnable program? */
1444
__attribute__((nonnull, warn_unused_result))
1445
int runnable_hook(const struct dirent *direntry){
1450
if((direntry->d_name)[0] == '\0'){
1455
sret = strspn(direntry->d_name, "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
1456
"abcdefghijklmnopqrstuvwxyz"
1459
if((direntry->d_name)[sret] != '\0'){
1460
/* Contains non-allowed characters */
1462
fprintf_plus(stderr, "Ignoring hook \"%s\" with bad name\n",
1468
ret = fstatat(hookdir_fd, direntry->d_name, &st, 0);
1471
perror_plus("Could not stat hook");
1475
if(not (S_ISREG(st.st_mode))){
1476
/* Not a regular file */
1478
fprintf_plus(stderr, "Ignoring hook \"%s\" - not a file\n",
1483
if(not (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))){
1484
/* Not executable */
1486
fprintf_plus(stderr, "Ignoring hook \"%s\" - not executable\n",
1492
fprintf_plus(stderr, "Hook \"%s\" is acceptable\n",
1498
__attribute__((nonnull, warn_unused_result))
1499
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,
1500
mandos_context *mc){
1502
struct timespec now;
1503
struct timespec waited_time;
1504
intmax_t block_time;
1507
if(mc->current_server == NULL){
1509
fprintf_plus(stderr, "Wait until first server is found."
1512
ret = avahi_simple_poll_iterate(s, -1);
1515
fprintf_plus(stderr, "Check current_server if we should run"
1518
/* the current time */
1519
ret = clock_gettime(CLOCK_MONOTONIC, &now);
1521
perror_plus("clock_gettime");
1524
/* Calculating in ms how long time between now and server
1525
who we visted longest time ago. Now - last seen. */
1526
waited_time.tv_sec = (now.tv_sec
1527
- mc->current_server->last_seen.tv_sec);
1528
waited_time.tv_nsec = (now.tv_nsec
1529
- mc->current_server->last_seen.tv_nsec);
1530
/* total time is 10s/10,000ms.
1531
Converting to s from ms by dividing by 1,000,
1532
and ns to ms by dividing by 1,000,000. */
1533
block_time = ((retry_interval
1534
- ((intmax_t)waited_time.tv_sec * 1000))
1535
- ((intmax_t)waited_time.tv_nsec / 1000000));
1538
fprintf_plus(stderr, "Blocking for %" PRIdMAX " ms\n",
1542
if(block_time <= 0){
1543
ret = start_mandos_communication(mc->current_server->ip,
1544
mc->current_server->port,
1545
mc->current_server->if_index,
1546
mc->current_server->af, mc);
1548
avahi_simple_poll_quit(s);
1551
ret = clock_gettime(CLOCK_MONOTONIC,
1552
&mc->current_server->last_seen);
1554
perror_plus("clock_gettime");
1557
mc->current_server = mc->current_server->next;
1558
block_time = 0; /* Call avahi to find new Mandos
1559
servers, but don't block */
1562
ret = avahi_simple_poll_iterate(s, (int)block_time);
1565
if(ret > 0 or errno != EINTR){
1566
return (ret != 1) ? ret : 0;
1572
/* Set effective uid to 0, return errno */
1573
__attribute__((warn_unused_result))
1574
error_t raise_privileges(void){
1575
error_t old_errno = errno;
1576
error_t ret_errno = 0;
1577
if(seteuid(0) == -1){
1584
/* Set effective and real user ID to 0. Return errno. */
1585
__attribute__((warn_unused_result))
1586
error_t raise_privileges_permanently(void){
1587
error_t old_errno = errno;
1588
error_t ret_errno = raise_privileges();
1593
if(setuid(0) == -1){
1600
/* Set effective user ID to unprivileged saved user ID */
1601
__attribute__((warn_unused_result))
1602
error_t lower_privileges(void){
1603
error_t old_errno = errno;
1604
error_t ret_errno = 0;
1605
if(seteuid(uid) == -1){
1612
/* Lower privileges permanently */
1613
__attribute__((warn_unused_result))
1614
error_t lower_privileges_permanently(void){
1615
error_t old_errno = errno;
1616
error_t ret_errno = 0;
1617
if(setuid(uid) == -1){
1624
__attribute__((nonnull))
1625
void run_network_hooks(const char *mode, const char *interface,
1627
struct dirent **direntries = NULL;
1628
if(hookdir_fd == -1){
1629
hookdir_fd = open(hookdir, O_RDONLY);
1630
if(hookdir_fd == -1){
1631
if(errno == ENOENT){
1633
fprintf_plus(stderr, "Network hook directory \"%s\" not"
1634
" found\n", hookdir);
1637
perror_plus("open");
1643
#if __GLIBC_PREREQ(2, 15)
1644
int numhooks = scandirat(hookdir_fd, ".", &direntries,
1645
runnable_hook, alphasort);
1646
#else /* not __GLIBC_PREREQ(2, 15) */
1647
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1649
#endif /* not __GLIBC_PREREQ(2, 15) */
1650
#else /* not __GLIBC__ */
1651
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1653
#endif /* not __GLIBC__ */
1655
perror_plus("scandir");
1658
struct dirent *direntry;
1660
int devnull = open("/dev/null", O_RDONLY);
1661
for(int i = 0; i < numhooks; i++){
1662
direntry = direntries[i];
1664
fprintf_plus(stderr, "Running network hook \"%s\"\n",
1667
pid_t hook_pid = fork();
1670
/* Raise privileges */
1671
errno = raise_privileges_permanently();
1673
perror_plus("Failed to raise privileges");
1680
perror_plus("setgid");
1683
/* Reset supplementary groups */
1685
ret = setgroups(0, NULL);
1687
perror_plus("setgroups");
1690
ret = dup2(devnull, STDIN_FILENO);
1692
perror_plus("dup2(devnull, STDIN_FILENO)");
1695
ret = close(devnull);
1697
perror_plus("close");
1700
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
1702
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
1705
ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);
1707
perror_plus("setenv");
1710
ret = setenv("DEVICE", interface, 1);
1712
perror_plus("setenv");
1715
ret = setenv("VERBOSITY", debug ? "1" : "0", 1);
1717
perror_plus("setenv");
1720
ret = setenv("MODE", mode, 1);
1722
perror_plus("setenv");
1726
ret = asprintf(&delaystring, "%f", (double)delay);
1728
perror_plus("asprintf");
1731
ret = setenv("DELAY", delaystring, 1);
1734
perror_plus("setenv");
1738
if(connect_to != NULL){
1739
ret = setenv("CONNECT", connect_to, 1);
1741
perror_plus("setenv");
1745
int hook_fd = openat(hookdir_fd, direntry->d_name, O_RDONLY);
1747
perror_plus("openat");
1748
_exit(EXIT_FAILURE);
1750
if((int)TEMP_FAILURE_RETRY(close(hookdir_fd)) == -1){
1751
perror_plus("close");
1752
_exit(EXIT_FAILURE);
1754
if(fexecve(hook_fd, (char *const []){ direntry->d_name, NULL },
1756
perror_plus("fexecve");
1757
_exit(EXIT_FAILURE);
1761
perror_plus("fork");
1766
if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){
1767
perror_plus("waitpid");
1771
if(WIFEXITED(status)){
1772
if(WEXITSTATUS(status) != 0){
1773
fprintf_plus(stderr, "Warning: network hook \"%s\" exited"
1774
" with status %d\n", direntry->d_name,
1775
WEXITSTATUS(status));
1779
} else if(WIFSIGNALED(status)){
1780
fprintf_plus(stderr, "Warning: network hook \"%s\" died by"
1781
" signal %d\n", direntry->d_name,
1786
fprintf_plus(stderr, "Warning: network hook \"%s\""
1787
" crashed\n", direntry->d_name);
1793
fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",
1799
if((int)TEMP_FAILURE_RETRY(close(hookdir_fd)) == -1){
1800
perror_plus("close");
1807
__attribute__((nonnull, warn_unused_result))
1808
error_t bring_up_interface(const char *const interface,
1810
error_t old_errno = errno;
1812
struct ifreq network;
1813
unsigned int if_index = if_nametoindex(interface);
1815
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1825
if(not interface_is_up(interface)){
1826
error_t ret_errno = 0, ioctl_errno = 0;
1827
if(not get_flags(interface, &network)){
1829
fprintf_plus(stderr, "Failed to get flags for interface "
1830
"\"%s\"\n", interface);
1834
network.ifr_flags |= IFF_UP; /* set flag */
1836
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1839
perror_plus("socket");
1845
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1847
perror_plus("close");
1854
fprintf_plus(stderr, "Bringing up interface \"%s\"\n",
1858
/* Raise privileges */
1859
ret_errno = raise_privileges();
1862
perror_plus("Failed to raise privileges");
1867
bool restore_loglevel = false;
1869
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1870
messages about the network interface to mess up the prompt */
1871
ret_linux = klogctl(8, NULL, 5);
1872
if(ret_linux == -1){
1873
perror_plus("klogctl");
1875
restore_loglevel = true;
1878
#endif /* __linux__ */
1879
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1880
ioctl_errno = errno;
1882
if(restore_loglevel){
1883
ret_linux = klogctl(7, NULL, 0);
1884
if(ret_linux == -1){
1885
perror_plus("klogctl");
1888
#endif /* __linux__ */
1890
/* If raise_privileges() succeeded above */
1892
/* Lower privileges */
1893
ret_errno = lower_privileges();
1896
perror_plus("Failed to lower privileges");
1900
/* Close the socket */
1901
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1903
perror_plus("close");
1906
if(ret_setflags == -1){
1907
errno = ioctl_errno;
1908
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1913
fprintf_plus(stderr, "Interface \"%s\" is already up; good\n",
1917
/* Sleep checking until interface is running.
1918
Check every 0.25s, up to total time of delay */
1919
for(int i=0; i < delay * 4; i++){
1920
if(interface_is_running(interface)){
1075
tmpmax = strtoimax(flagstring, &tmp, 0);
1076
if(errno != 0 or tmp == flagstring or (*tmp != '\0'
1077
and not (isspace(*tmp)))
1078
or tmpmax != (ifreq_flags)tmpmax){
1080
fprintf(stderr, "Invalid flags \"%s\" for interface \"%s\"\n",
1081
flagstring, if_entry->d_name);
1087
ifreq_flags flags = (ifreq_flags)tmpmax;
1088
/* Reject the loopback device */
1089
if(flags & IFF_LOOPBACK){
1091
fprintf(stderr, "Rejecting loopback interface \"%s\"\n",
1096
/* Accept point-to-point devices only if connect_to is specified */
1097
if(connect_to != NULL and (flags & IFF_POINTOPOINT)){
1099
fprintf(stderr, "Accepting point-to-point interface \"%s\"\n",
1104
/* Otherwise, reject non-broadcast-capable devices */
1105
if(not (flags & IFF_BROADCAST)){
1107
fprintf(stderr, "Rejecting non-broadcast interface \"%s\"\n",
1112
/* Accept this device */
1114
fprintf(stderr, "Interface \"%s\" is acceptable\n",
1923
struct timespec sleeptime = { .tv_nsec = 250000000 };
1924
ret = nanosleep(&sleeptime, NULL);
1925
if(ret == -1 and errno != EINTR){
1926
perror_plus("nanosleep");
1934
__attribute__((nonnull, warn_unused_result))
1935
error_t take_down_interface(const char *const interface){
1936
error_t old_errno = errno;
1937
struct ifreq network;
1938
unsigned int if_index = if_nametoindex(interface);
1940
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1944
if(interface_is_up(interface)){
1945
error_t ret_errno = 0, ioctl_errno = 0;
1946
if(not get_flags(interface, &network) and debug){
1948
fprintf_plus(stderr, "Failed to get flags for interface "
1949
"\"%s\"\n", interface);
1953
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1955
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1958
perror_plus("socket");
1964
fprintf_plus(stderr, "Taking down interface \"%s\"\n",
1968
/* Raise privileges */
1969
ret_errno = raise_privileges();
1972
perror_plus("Failed to raise privileges");
1975
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1976
ioctl_errno = errno;
1978
/* If raise_privileges() succeeded above */
1980
/* Lower privileges */
1981
ret_errno = lower_privileges();
1984
perror_plus("Failed to lower privileges");
1988
/* Close the socket */
1989
int ret = (int)TEMP_FAILURE_RETRY(close(sd));
1991
perror_plus("close");
1994
if(ret_setflags == -1){
1995
errno = ioctl_errno;
1996
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
2001
fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",
1120
2009
int main(int argc, char *argv[]){
2010
mandos_context mc = { .server = NULL, .dh_bits = 0,
2011
.priority = "SECURE256:!CTYPE-X.509:"
2012
"+CTYPE-OPENPGP:!RSA", .current_server = NULL,
2013
.interfaces = NULL, .interfaces_size = 0 };
1121
2014
AvahiSServiceBrowser *sb = NULL;
1124
2017
intmax_t tmpmax;
1126
2019
int exitcode = EXIT_SUCCESS;
1127
const char *interface = "";
1128
struct ifreq network;
1130
bool take_down_interface = false;
1133
char tempdir[] = "/tmp/mandosXXXXXX";
1134
bool tempdir_created = false;
2020
char *interfaces_to_take_down = NULL;
2021
size_t interfaces_to_take_down_size = 0;
2022
char run_tempdir[] = "/run/tmp/mandosXXXXXX";
2023
char old_tempdir[] = "/tmp/mandosXXXXXX";
2024
char *tempdir = NULL;
1135
2025
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
1136
2026
const char *seckey = PATHDIR "/" SECKEY;
1137
2027
const char *pubkey = PATHDIR "/" PUBKEY;
2028
char *interfaces_hooks = NULL;
1139
2030
bool gnutls_initialized = false;
1140
2031
bool gpgme_initialized = false;
1141
2032
float delay = 2.5f;
2033
double retry_interval = 10; /* 10s between trying a server and
2034
retrying the same server again */
1143
2036
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
1144
2037
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
1355
2342
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1357
perror("sigaction");
2344
perror_plus("sigaction");
1358
2345
return EX_OSERR;
1360
2347
if(old_sigterm_action.sa_handler != SIG_IGN){
1361
2348
ret = sigaction(SIGINT, &sigterm_action, NULL);
1363
perror("sigaction");
2350
perror_plus("sigaction");
1364
2351
exitcode = EX_OSERR;
1368
2355
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1370
perror("sigaction");
2357
perror_plus("sigaction");
1371
2358
return EX_OSERR;
1373
2360
if(old_sigterm_action.sa_handler != SIG_IGN){
1374
2361
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1376
perror("sigaction");
2363
perror_plus("sigaction");
1377
2364
exitcode = EX_OSERR;
1381
2368
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1383
perror("sigaction");
2370
perror_plus("sigaction");
1384
2371
return EX_OSERR;
1386
2373
if(old_sigterm_action.sa_handler != SIG_IGN){
1387
2374
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1389
perror("sigaction");
1390
exitcode = EX_OSERR;
1395
/* If the interface is down, bring it up */
1396
if(strcmp(interface, "none") != 0){
1397
if_index = (AvahiIfIndex) if_nametoindex(interface);
1399
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1400
exitcode = EX_UNAVAILABLE;
1408
/* Re-raise priviliges */
1416
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1417
messages about the network interface to mess up the prompt */
1418
ret = klogctl(8, NULL, 5);
1419
bool restore_loglevel = true;
1421
restore_loglevel = false;
1424
#endif /* __linux__ */
1426
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1429
exitcode = EX_OSERR;
1431
if(restore_loglevel){
1432
ret = klogctl(7, NULL, 0);
1437
#endif /* __linux__ */
1438
/* Lower privileges */
1446
strcpy(network.ifr_name, interface);
1447
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1449
perror("ioctl SIOCGIFFLAGS");
1451
if(restore_loglevel){
1452
ret = klogctl(7, NULL, 0);
1457
#endif /* __linux__ */
1458
exitcode = EX_OSERR;
1459
/* Lower privileges */
1467
if((network.ifr_flags & IFF_UP) == 0){
1468
network.ifr_flags |= IFF_UP;
1469
take_down_interface = true;
1470
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1472
take_down_interface = false;
1473
perror("ioctl SIOCSIFFLAGS +IFF_UP");
1474
exitcode = EX_OSERR;
1476
if(restore_loglevel){
1477
ret = klogctl(7, NULL, 0);
2376
perror_plus("sigaction");
2377
exitcode = EX_OSERR;
2382
/* If no interfaces were specified, make a list */
2383
if(mc.interfaces == NULL){
2384
struct dirent **direntries = NULL;
2385
/* Look for any good interfaces */
2386
ret = scandir(sys_class_net, &direntries, good_interface,
2389
/* Add all found interfaces to interfaces list */
2390
for(int i = 0; i < ret; ++i){
2391
ret_errno = argz_add(&mc.interfaces, &mc.interfaces_size,
2392
direntries[i]->d_name);
2395
perror_plus("argz_add");
2396
free(direntries[i]);
2400
fprintf_plus(stderr, "Will use interface \"%s\"\n",
2401
direntries[i]->d_name);
2403
free(direntries[i]);
2410
fprintf_plus(stderr, "Could not find a network interface\n");
2411
exitcode = EXIT_FAILURE;
2416
/* Bring up interfaces which are down, and remove any "none"s */
2418
char *interface = NULL;
2419
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2421
/* If interface name is "none", stop bringing up interfaces.
2422
Also remove all instances of "none" from the list */
2423
if(strcmp(interface, "none") == 0){
2424
argz_delete(&mc.interfaces, &mc.interfaces_size,
2427
while((interface = argz_next(mc.interfaces,
2428
mc.interfaces_size, interface))){
2429
if(strcmp(interface, "none") == 0){
2430
argz_delete(&mc.interfaces, &mc.interfaces_size,
1482
#endif /* __linux__ */
1483
/* Lower privileges */
1492
/* sleep checking until interface is running */
1493
for(int i=0; i < delay * 4; i++){
1494
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1496
perror("ioctl SIOCGIFFLAGS");
1497
} else if(network.ifr_flags & IFF_RUNNING){
1500
struct timespec sleeptime = { .tv_nsec = 250000000 };
1501
ret = nanosleep(&sleeptime, NULL);
1502
if(ret == -1 and errno != EINTR){
1503
perror("nanosleep");
1506
if(not take_down_interface){
1507
/* We won't need the socket anymore */
1508
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1514
if(restore_loglevel){
1515
/* Restores kernel loglevel to default */
1516
ret = klogctl(7, NULL, 0);
1521
#endif /* __linux__ */
1522
/* Lower privileges */
1524
if(take_down_interface){
1525
/* Lower privileges */
1531
/* Lower privileges permanently */
2437
bool interface_was_up = interface_is_up(interface);
2438
errno = bring_up_interface(interface, delay);
2439
if(not interface_was_up){
2441
perror_plus("Failed to bring up interface");
2443
errno = argz_add(&interfaces_to_take_down,
2444
&interfaces_to_take_down_size,
2447
perror_plus("argz_add");
2452
if(debug and (interfaces_to_take_down == NULL)){
2453
fprintf_plus(stderr, "No interfaces were brought up\n");
2457
/* If we only got one interface, explicitly use only that one */
2458
if(argz_count(mc.interfaces, mc.interfaces_size) == 1){
2460
fprintf_plus(stderr, "Using only interface \"%s\"\n",
2463
if_index = (AvahiIfIndex)if_nametoindex(mc.interfaces);
1543
ret = init_gnutls_global(pubkey, seckey);
2470
ret = init_gnutls_global(pubkey, seckey, &mc);
1545
fprintf(stderr, "init_gnutls_global failed\n");
2472
fprintf_plus(stderr, "init_gnutls_global failed\n");
1546
2473
exitcode = EX_UNAVAILABLE;
1729
2670
gpgme_release(mc.ctx);
1732
/* Take down the network interface */
1733
if(take_down_interface){
1734
/* Re-raise priviliges */
1741
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1743
perror("ioctl SIOCGIFFLAGS");
1744
} else if(network.ifr_flags & IFF_UP) {
1745
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1746
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1748
perror("ioctl SIOCSIFFLAGS -IFF_UP");
1751
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1755
/* Lower privileges permanently */
1764
/* Removes the temp directory used by GPGME */
1765
if(tempdir_created){
1767
struct dirent *direntry;
1768
d = opendir(tempdir);
1770
if(errno != ENOENT){
1775
direntry = readdir(d);
1776
if(direntry == NULL){
1779
/* Skip "." and ".." */
1780
if(direntry->d_name[0] == '.'
1781
and (direntry->d_name[1] == '\0'
1782
or (direntry->d_name[1] == '.'
1783
and direntry->d_name[2] == '\0'))){
1786
char *fullname = NULL;
1787
ret = asprintf(&fullname, "%s/%s", tempdir,
1793
ret = remove(fullname);
1795
fprintf(stderr, "remove(\"%s\"): %s\n", fullname,
1802
ret = rmdir(tempdir);
1803
if(ret == -1 and errno != ENOENT){
2673
/* Cleans up the circular linked list of Mandos servers the client
2675
if(mc.current_server != NULL){
2676
mc.current_server->prev->next = NULL;
2677
while(mc.current_server != NULL){
2678
server *next = mc.current_server->next;
2680
#pragma GCC diagnostic push
2681
#pragma GCC diagnostic ignored "-Wcast-qual"
2683
free((char *)(mc.current_server->ip));
2685
#pragma GCC diagnostic pop
2687
free(mc.current_server);
2688
mc.current_server = next;
2692
/* Re-raise privileges */
2694
ret_errno = raise_privileges();
2697
perror_plus("Failed to raise privileges");
2700
/* Run network hooks */
2701
run_network_hooks("stop", interfaces_hooks != NULL ?
2702
interfaces_hooks : "", delay);
2704
/* Take down the network interfaces which were brought up */
2706
char *interface = NULL;
2707
while((interface=argz_next(interfaces_to_take_down,
2708
interfaces_to_take_down_size,
2710
ret_errno = take_down_interface(interface);
2713
perror_plus("Failed to take down interface");
2716
if(debug and (interfaces_to_take_down == NULL)){
2717
fprintf_plus(stderr, "No interfaces needed to be taken"
2723
ret_errno = lower_privileges_permanently();
2726
perror_plus("Failed to lower privileges permanently");
2730
free(interfaces_to_take_down);
2731
free(interfaces_hooks);
2733
/* Removes the GPGME temp directory and all files inside */
2734
if(tempdir != NULL){
2735
struct dirent **direntries = NULL;
2736
int tempdir_fd = (int)TEMP_FAILURE_RETRY(open(tempdir, O_RDONLY |
2738
if(tempdir_fd == -1){
2739
perror_plus("open");
2742
#if __GLIBC_PREREQ(2, 15)
2743
int numentries = scandirat(tempdir_fd, ".", &direntries,
2744
notdotentries, alphasort);
2745
#else /* not __GLIBC_PREREQ(2, 15) */
2746
int numentries = scandir(tempdir, &direntries, notdotentries,
2748
#endif /* not __GLIBC_PREREQ(2, 15) */
2749
#else /* not __GLIBC__ */
2750
int numentries = scandir(tempdir, &direntries, notdotentries,
2752
#endif /* not __GLIBC__ */
2753
if(numentries >= 0){
2754
for(int i = 0; i < numentries; i++){
2755
ret = unlinkat(tempdir_fd, direntries[i]->d_name, 0);
2757
fprintf_plus(stderr, "unlinkat(open(\"%s\", O_RDONLY),"
2758
" \"%s\", 0): %s\n", tempdir,
2759
direntries[i]->d_name, strerror(errno));
2761
free(direntries[i]);
2764
/* need to clean even if 0 because man page doesn't specify */
2766
if(numentries == -1){
2767
perror_plus("scandir");
2769
ret = rmdir(tempdir);
2770
if(ret == -1 and errno != ENOENT){
2771
perror_plus("rmdir");
2774
TEMP_FAILURE_RETRY(close(tempdir_fd));