161
157
const char *priority;
163
159
server *current_server;
165
size_t interfaces_size;
166
160
} mandos_context;
168
/* global so signal handler can reach it*/
169
AvahiSimplePoll *simple_poll;
162
/* global context so signal handler can reach it*/
163
mandos_context mc = { .simple_poll = NULL, .server = NULL,
164
.dh_bits = 1024, .priority = "SECURE256"
165
":!CTYPE-X.509:+CTYPE-OPENPGP",
166
.current_server = NULL };
171
168
sig_atomic_t quit_now = 0;
172
169
int signal_received = 0;
174
171
/* Function to use when printing errors */
175
172
void perror_plus(const char *print_text){
177
173
fprintf(stderr, "Mandos plugin %s: ",
178
174
program_invocation_short_name);
180
175
perror(print_text);
183
__attribute__((format (gnu_printf, 2, 3)))
184
178
int fprintf_plus(FILE *stream, const char *format, ...){
186
180
va_start (ap, format);
223
217
if(new_server->ip == NULL){
224
218
perror_plus("strdup");
227
221
/* Special case of first server */
228
if(*current_server == NULL){
222
if (mc.current_server == NULL){
229
223
new_server->next = new_server;
230
224
new_server->prev = new_server;
231
*current_server = new_server;
225
mc.current_server = new_server;
232
226
/* Place the new server last in the list */
234
new_server->next = *current_server;
235
new_server->prev = (*current_server)->prev;
228
new_server->next = mc.current_server;
229
new_server->prev = mc.current_server->prev;
236
230
new_server->prev->next = new_server;
237
(*current_server)->prev = new_server;
231
mc.current_server->prev = new_server;
239
ret = clock_gettime(CLOCK_MONOTONIC, &(*current_server)->last_seen);
233
ret = clock_gettime(CLOCK_MONOTONIC, &mc.current_server->last_seen);
241
235
perror_plus("clock_gettime");
248
242
* Initialize GPGME.
250
244
static bool init_gpgme(const char *seckey, const char *pubkey,
251
const char *tempdir, mandos_context *mc){
245
const char *tempdir){
252
246
gpgme_error_t rc;
253
247
gpgme_engine_info_t engine_info;
256
251
* Helper function to insert pub and seckey to the engine keyring.
378
372
/* Decrypt data from the cryptotext data buffer to the plaintext
380
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
374
rc = gpgme_op_decrypt(mc.ctx, dh_crypto, dh_plain);
381
375
if(rc != GPG_ERR_NO_ERROR){
382
376
fprintf_plus(stderr, "bad gpgme_op_decrypt: %s: %s\n",
383
377
gpgme_strsource(rc), gpgme_strerror(rc));
384
378
plaintext_length = -1;
386
380
gpgme_decrypt_result_t result;
387
result = gpgme_op_decrypt_result(mc->ctx);
381
result = gpgme_op_decrypt_result(mc.ctx);
388
382
if(result == NULL){
389
383
fprintf_plus(stderr, "gpgme_op_decrypt_result failed\n");
535
529
/* GnuTLS server initialization */
536
ret = gnutls_dh_params_init(&mc->dh_params);
530
ret = gnutls_dh_params_init(&mc.dh_params);
537
531
if(ret != GNUTLS_E_SUCCESS){
538
532
fprintf_plus(stderr, "Error in GnuTLS DH parameter"
539
533
" initialization: %s\n",
540
534
safer_gnutls_strerror(ret));
543
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
537
ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);
544
538
if(ret != GNUTLS_E_SUCCESS){
545
539
fprintf_plus(stderr, "Error in GnuTLS prime generation: %s\n",
546
540
safer_gnutls_strerror(ret));
550
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
544
gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);
556
gnutls_certificate_free_credentials(mc->cred);
550
gnutls_certificate_free_credentials(mc.cred);
557
551
gnutls_global_deinit();
558
gnutls_dh_params_deinit(mc->dh_params);
552
gnutls_dh_params_deinit(mc.dh_params);
562
static int init_gnutls_session(gnutls_session_t *session,
556
static int init_gnutls_session(gnutls_session_t *session){
565
558
/* GnuTLS session creation */
733
729
if(if_indextoname((unsigned int)if_index, interface) == NULL){
734
730
perror_plus("if_indextoname");
736
fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIuMAX
737
"\n", ip, interface, (uintmax_t)port);
732
fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIu16
733
"\n", ip, interface, port);
740
fprintf_plus(stderr, "Connection to: %s, port %" PRIuMAX "\n",
741
ip, (uintmax_t)port);
736
fprintf_plus(stderr, "Connection to: %s, port %" PRIu16 "\n",
743
739
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
744
740
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
1035
1025
PRIdMAX ") on port %" PRIu16 "\n", name,
1036
1026
host_name, ip, (intmax_t)interface, port);
1038
int ret = start_mandos_communication(ip, (in_port_t)port,
1040
avahi_proto_to_af(proto),
1028
int ret = start_mandos_communication(ip, port, interface,
1029
avahi_proto_to_af(proto));
1043
avahi_simple_poll_quit(simple_poll);
1031
avahi_simple_poll_quit(mc.simple_poll);
1045
if(not add_server(ip, (in_port_t)port, interface,
1046
avahi_proto_to_af(proto),
1047
&((mandos_context*)mc)->current_server)){
1048
fprintf_plus(stderr, "Failed to add server \"%s\" to server"
1033
ret = add_server(ip, port, interface,
1034
avahi_proto_to_af(proto));
1091
1072
the callback function is called the Avahi server will free the
1092
1073
resolver for us. */
1094
if(avahi_s_service_resolver_new(((mandos_context*)mc)->server,
1095
interface, protocol, name, type,
1096
domain, protocol, 0,
1097
resolve_callback, mc) == NULL)
1075
if(avahi_s_service_resolver_new(mc.server, interface, protocol,
1076
name, type, domain, protocol, 0,
1077
resolve_callback, NULL) == NULL)
1098
1078
fprintf_plus(stderr, "Avahi: Failed to resolve service '%s':"
1100
avahi_strerror(avahi_server_errno
1101
(((mandos_context*)mc)->server)));
1080
avahi_strerror(avahi_server_errno(mc.server)));
1104
1083
case AVAHI_BROWSER_REMOVE:
1224
* This function determines if a network interface is up.
1226
bool interface_is_up(const char *interface){
1228
if(not get_flags(interface, &ifr)){
1230
fprintf_plus(stderr, "Failed to get flags for interface "
1231
"\"%s\"\n", interface);
1236
return (bool)(ifr.ifr_flags & IFF_UP);
1240
* This function determines if a network interface is running
1242
bool interface_is_running(const char *interface){
1244
if(not get_flags(interface, &ifr)){
1246
fprintf_plus(stderr, "Failed to get flags for interface "
1247
"\"%s\"\n", interface);
1252
return (bool)(ifr.ifr_flags & IFF_RUNNING);
1198
* This function determines if a directory entry in /sys/class/net
1199
* corresponds to an acceptable network device which is up.
1200
* (This function is passed to scandir(3) as a filter function.)
1202
int up_interface(const struct dirent *if_entry){
1203
if(if_entry->d_name[0] == '.'){
1208
if(not get_flags(if_entry->d_name, &ifr)){
1210
fprintf_plus(stderr, "Failed to get flags for interface "
1211
"\"%s\"\n", if_entry->d_name);
1216
/* Reject down interfaces */
1217
if(not (ifr.ifr_flags & IFF_UP)){
1219
fprintf_plus(stderr, "Rejecting down interface \"%s\"\n",
1225
/* Reject non-running interfaces */
1226
if(not (ifr.ifr_flags & IFF_RUNNING)){
1228
fprintf_plus(stderr, "Rejecting non-running interface \"%s\"\n",
1234
if(not good_flags(if_entry->d_name, &ifr)){
1255
1240
int notdotentries(const struct dirent *direntry){
1370
1354
if(block_time <= 0){
1371
ret = start_mandos_communication(mc->current_server->ip,
1372
mc->current_server->port,
1373
mc->current_server->if_index,
1374
mc->current_server->af, mc);
1355
ret = start_mandos_communication(mc.current_server->ip,
1356
mc.current_server->port,
1357
mc.current_server->if_index,
1358
mc.current_server->af);
1376
avahi_simple_poll_quit(s);
1360
avahi_simple_poll_quit(mc.simple_poll);
1379
1363
ret = clock_gettime(CLOCK_MONOTONIC,
1380
&mc->current_server->last_seen);
1364
&mc.current_server->last_seen);
1382
1366
perror_plus("clock_gettime");
1385
mc->current_server = mc->current_server->next;
1369
mc.current_server = mc.current_server->next;
1386
1370
block_time = 0; /* Call avahi to find new Mandos
1387
1371
servers, but don't block */
1400
/* Set effective uid to 0, return errno */
1401
error_t raise_privileges(void){
1402
error_t old_errno = errno;
1403
error_t ret_errno = 0;
1404
if(seteuid(0) == -1){
1406
perror_plus("seteuid");
1412
/* Set effective and real user ID to 0. Return errno. */
1413
error_t raise_privileges_permanently(void){
1414
error_t old_errno = errno;
1415
error_t ret_errno = raise_privileges();
1420
if(setuid(0) == -1){
1422
perror_plus("seteuid");
1428
/* Set effective user ID to unprivileged saved user ID */
1429
error_t lower_privileges(void){
1430
error_t old_errno = errno;
1431
error_t ret_errno = 0;
1432
if(seteuid(uid) == -1){
1434
perror_plus("seteuid");
1440
/* Lower privileges permanently */
1441
error_t lower_privileges_permanently(void){
1442
error_t old_errno = errno;
1443
error_t ret_errno = 0;
1444
if(setuid(uid) == -1){
1446
perror_plus("setuid");
1452
1384
bool run_network_hooks(const char *mode, const char *interface,
1453
1385
const float delay){
1454
1386
struct dirent **direntries;
1585
error_t bring_up_interface(const char *const interface,
1588
error_t old_errno = errno;
1589
error_t ret_errno = 0;
1590
int ret, ret_setflags;
1591
struct ifreq network;
1592
unsigned int if_index = if_nametoindex(interface);
1594
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1604
if(not interface_is_up(interface)){
1605
if(not get_flags(interface, &network) and debug){
1607
fprintf_plus(stderr, "Failed to get flags for interface "
1608
"\"%s\"\n", interface);
1611
network.ifr_flags |= IFF_UP;
1613
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1616
perror_plus("socket");
1628
fprintf_plus(stderr, "Bringing up interface \"%s\"\n",
1632
/* Raise priviliges */
1636
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1637
messages about the network interface to mess up the prompt */
1638
int ret_linux = klogctl(8, NULL, 5);
1639
bool restore_loglevel = true;
1640
if(ret_linux == -1){
1641
restore_loglevel = false;
1642
perror_plus("klogctl");
1644
#endif /* __linux__ */
1645
ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1648
if(restore_loglevel){
1649
ret_linux = klogctl(7, NULL, 0);
1650
if(ret_linux == -1){
1651
perror_plus("klogctl");
1654
#endif /* __linux__ */
1656
/* Lower privileges */
1659
/* Close the socket */
1660
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1662
perror_plus("close");
1665
if(ret_setflags == -1){
1667
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1672
fprintf_plus(stderr, "Interface \"%s\" is already up; good\n",
1676
/* Sleep checking until interface is running.
1677
Check every 0.25s, up to total time of delay */
1678
for(int i=0; i < delay * 4; i++){
1679
if(interface_is_running(interface)){
1682
struct timespec sleeptime = { .tv_nsec = 250000000 };
1683
ret = nanosleep(&sleeptime, NULL);
1684
if(ret == -1 and errno != EINTR){
1685
perror_plus("nanosleep");
1693
error_t take_down_interface(const char *const interface){
1695
error_t old_errno = errno;
1696
error_t ret_errno = 0;
1697
int ret, ret_setflags;
1698
struct ifreq network;
1699
unsigned int if_index = if_nametoindex(interface);
1701
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1705
if(interface_is_up(interface)){
1706
if(not get_flags(interface, &network) and debug){
1708
fprintf_plus(stderr, "Failed to get flags for interface "
1709
"\"%s\"\n", interface);
1712
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1714
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1717
perror_plus("socket");
1723
fprintf_plus(stderr, "Taking down interface \"%s\"\n",
1727
/* Raise priviliges */
1730
ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1733
/* Lower privileges */
1736
/* Close the socket */
1737
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1739
perror_plus("close");
1742
if(ret_setflags == -1){
1744
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
1749
fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",
1757
1511
int main(int argc, char *argv[]){
1758
mandos_context mc = { .server = NULL, .dh_bits = 1024,
1759
.priority = "SECURE256:!CTYPE-X.509:"
1760
"+CTYPE-OPENPGP", .current_server = NULL,
1761
.interfaces = NULL, .interfaces_size = 0 };
1762
1512
AvahiSServiceBrowser *sb = NULL;
1765
1515
intmax_t tmpmax;
1767
1517
int exitcode = EXIT_SUCCESS;
1768
char *interfaces_to_take_down = NULL;
1769
size_t interfaces_to_take_down_size = 0;
1518
const char *interface = "";
1519
struct ifreq network;
1521
bool take_down_interface = false;
1770
1524
char tempdir[] = "/tmp/mandosXXXXXX";
1771
1525
bool tempdir_created = false;
1772
1526
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
1773
1527
const char *seckey = PATHDIR "/" SECKEY;
1774
1528
const char *pubkey = PATHDIR "/" PUBKEY;
1775
char *interfaces_hooks = NULL;
1776
size_t interfaces_hooks_size = 0;
1778
1530
bool gnutls_initialized = false;
1779
1531
bool gpgme_initialized = false;
2015
/* Remove empty interface names */
2017
char *interface = NULL;
2018
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2020
if(if_nametoindex(interface) == 0){
2021
if(interface[0] != '\0' and strcmp(interface, "none") != 0){
2022
fprintf_plus(stderr, "Not using nonexisting interface"
2023
" \"%s\"\n", interface);
2025
argz_delete(&mc.interfaces, &mc.interfaces_size, interface);
2031
1769
/* Run network hooks */
2034
if(mc.interfaces != NULL){
2035
interfaces_hooks = malloc(mc.interfaces_size);
2036
if(interfaces_hooks == NULL){
2037
perror_plus("malloc");
2040
memcpy(interfaces_hooks, mc.interfaces, mc.interfaces_size);
2041
interfaces_hooks_size = mc.interfaces_size;
2042
argz_stringify(interfaces_hooks, interfaces_hooks_size,
2045
if(not run_network_hooks("start", interfaces_hooks != NULL ?
2046
interfaces_hooks : "", delay)){
1770
if(not run_network_hooks("start", interface, delay)){
2052
1775
avahi_set_log_function(empty_log);
1778
if(interface[0] == '\0'){
1779
struct dirent **direntries;
1780
/* First look for interfaces that are up */
1781
ret = scandir(sys_class_net, &direntries, up_interface,
1784
/* No up interfaces, look for any good interfaces */
1786
ret = scandir(sys_class_net, &direntries, good_interface,
1790
/* Pick the first interface returned */
1791
interface = strdup(direntries[0]->d_name);
1793
fprintf_plus(stderr, "Using interface \"%s\"\n", interface);
1795
if(interface == NULL){
1796
perror_plus("malloc");
1798
exitcode = EXIT_FAILURE;
1804
fprintf_plus(stderr, "Could not find a network interface\n");
1805
exitcode = EXIT_FAILURE;
2055
1810
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
2056
1811
from the signal handler */
2057
1812
/* Initialize the pseudo-RNG for Avahi */
2058
1813
srand((unsigned int) time(NULL));
2059
simple_poll = avahi_simple_poll_new();
2060
if(simple_poll == NULL){
1814
mc.simple_poll = avahi_simple_poll_new();
1815
if(mc.simple_poll == NULL){
2061
1816
fprintf_plus(stderr,
2062
1817
"Avahi: Failed to create simple poll object.\n");
2063
1818
exitcode = EX_UNAVAILABLE;
2130
/* If no interfaces were specified, make a list */
2131
if(mc.interfaces == NULL){
2132
struct dirent **direntries;
2133
/* Look for any good interfaces */
2134
ret = scandir(sys_class_net, &direntries, good_interface,
2137
/* Add all found interfaces to interfaces list */
2138
for(int i = 0; i < ret; ++i){
2139
ret_errno = argz_add(&mc.interfaces, &mc.interfaces_size,
2140
direntries[i]->d_name);
2142
perror_plus("argz_add");
2146
fprintf_plus(stderr, "Will use interface \"%s\"\n",
2147
direntries[i]->d_name);
2153
fprintf_plus(stderr, "Could not find a network interface\n");
2154
exitcode = EXIT_FAILURE;
2159
/* If we only got one interface, explicitly use only that one */
2160
if(argz_count(mc.interfaces, mc.interfaces_size) == 1){
2162
fprintf_plus(stderr, "Using only interface \"%s\"\n",
2165
if_index = (AvahiIfIndex)if_nametoindex(mc.interfaces);
2168
/* Bring up interfaces which are down */
2169
if(not (argz_count(mc.interfaces, mc.interfaces_size) == 1
2170
and strcmp(mc.interfaces, "none") == 0)){
2171
char *interface = NULL;
2172
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2174
bool interface_was_up = interface_is_up(interface);
2175
ret = bring_up_interface(interface, delay);
2176
if(not interface_was_up){
2179
perror_plus("Failed to bring up interface");
2181
ret_errno = argz_add(&interfaces_to_take_down,
2182
&interfaces_to_take_down_size,
2187
free(mc.interfaces);
2188
mc.interfaces = NULL;
2189
mc.interfaces_size = 0;
2190
if(debug and (interfaces_to_take_down == NULL)){
2191
fprintf_plus(stderr, "No interfaces were brought up\n");
1885
/* If the interface is down, bring it up */
1886
if(strcmp(interface, "none") != 0){
1887
if_index = (AvahiIfIndex) if_nametoindex(interface);
1889
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1890
exitcode = EX_UNAVAILABLE;
1898
/* Re-raise priviliges */
1902
perror_plus("seteuid");
1906
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1907
messages about the network interface to mess up the prompt */
1908
ret = klogctl(8, NULL, 5);
1909
bool restore_loglevel = true;
1911
restore_loglevel = false;
1912
perror_plus("klogctl");
1914
#endif /* __linux__ */
1916
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1918
perror_plus("socket");
1919
exitcode = EX_OSERR;
1921
if(restore_loglevel){
1922
ret = klogctl(7, NULL, 0);
1924
perror_plus("klogctl");
1927
#endif /* __linux__ */
1928
/* Lower privileges */
1932
perror_plus("seteuid");
1936
strcpy(network.ifr_name, interface);
1937
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1939
perror_plus("ioctl SIOCGIFFLAGS");
1941
if(restore_loglevel){
1942
ret = klogctl(7, NULL, 0);
1944
perror_plus("klogctl");
1947
#endif /* __linux__ */
1948
exitcode = EX_OSERR;
1949
/* Lower privileges */
1953
perror_plus("seteuid");
1957
if((network.ifr_flags & IFF_UP) == 0){
1958
network.ifr_flags |= IFF_UP;
1959
take_down_interface = true;
1960
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1962
take_down_interface = false;
1963
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1964
exitcode = EX_OSERR;
1966
if(restore_loglevel){
1967
ret = klogctl(7, NULL, 0);
1969
perror_plus("klogctl");
1972
#endif /* __linux__ */
1973
/* Lower privileges */
1977
perror_plus("seteuid");
1982
/* Sleep checking until interface is running.
1983
Check every 0.25s, up to total time of delay */
1984
for(int i=0; i < delay * 4; i++){
1985
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1987
perror_plus("ioctl SIOCGIFFLAGS");
1988
} else if(network.ifr_flags & IFF_RUNNING){
1991
struct timespec sleeptime = { .tv_nsec = 250000000 };
1992
ret = nanosleep(&sleeptime, NULL);
1993
if(ret == -1 and errno != EINTR){
1994
perror_plus("nanosleep");
1997
if(not take_down_interface){
1998
/* We won't need the socket anymore */
1999
ret = (int)TEMP_FAILURE_RETRY(close(sd));
2001
perror_plus("close");
2005
if(restore_loglevel){
2006
/* Restores kernel loglevel to default */
2007
ret = klogctl(7, NULL, 0);
2009
perror_plus("klogctl");
2012
#endif /* __linux__ */
2013
/* Lower privileges */
2015
/* Lower privileges */
2018
perror_plus("seteuid");
2228
/* Run network hooks */
2229
run_network_hooks("stop", interface, delay);
2403
2231
/* Re-raise priviliges */
2407
/* Run network hooks */
2408
run_network_hooks("stop", interfaces_hooks != NULL ?
2409
interfaces_hooks : "", delay);
2411
/* Take down the network interfaces which were brought up */
2413
char *interface = NULL;
2414
while((interface=argz_next(interfaces_to_take_down,
2415
interfaces_to_take_down_size,
2417
ret_errno = take_down_interface(interface);
2420
perror_plus("Failed to take down interface");
2236
perror_plus("seteuid");
2239
/* Take down the network interface */
2240
if(take_down_interface and geteuid() == 0){
2241
ret = ioctl(sd, SIOCGIFFLAGS, &network);
2243
perror_plus("ioctl SIOCGIFFLAGS");
2244
} else if(network.ifr_flags & IFF_UP){
2245
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
2246
ret = ioctl(sd, SIOCSIFFLAGS, &network);
2248
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
2423
if(debug and (interfaces_to_take_down == NULL)){
2424
fprintf_plus(stderr, "No interfaces needed to be taken"
2251
ret = (int)TEMP_FAILURE_RETRY(close(sd));
2253
perror_plus("close");
2429
lower_privileges_permanently();
2432
free(interfaces_to_take_down);
2433
free(interfaces_hooks);
2257
/* Lower privileges permanently */
2261
perror_plus("setuid");
2435
2264
/* Removes the GPGME temp directory and all files inside */
2436
2265
if(tempdir_created){