874
static void handle_sigterm(__attribute__((unused)) int sig){
1073
/* Signal handler that stops main loop after SIGTERM */
1074
static void handle_sigterm(int sig){
1079
signal_received = sig;
875
1080
int old_errno = errno;
876
avahi_simple_poll_quit(mc.simple_poll);
1081
/* set main loop to exit */
1082
if(mc.simple_poll != NULL){
1083
avahi_simple_poll_quit(mc.simple_poll);
877
1085
errno = old_errno;
1089
* This function determines if a directory entry in /sys/class/net
1090
* corresponds to an acceptable network device.
1091
* (This function is passed to scandir(3) as a filter function.)
1093
int good_interface(const struct dirent *if_entry){
1096
if(if_entry->d_name[0] == '.'){
1099
int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1101
perror_plus("socket");
1105
strcpy(ifr.ifr_name, if_entry->d_name);
1106
ret = ioctl(s, SIOCGIFFLAGS, &ifr);
1109
perror_plus("ioctl SIOCGIFFLAGS");
1113
/* Reject the loopback device */
1114
if(ifr.ifr_flags & IFF_LOOPBACK){
1116
fprintf(stderr, "Rejecting loopback interface \"%s\"\n",
1121
/* Accept point-to-point devices only if connect_to is specified */
1122
if(connect_to != NULL and (ifr.ifr_flags & IFF_POINTOPOINT)){
1124
fprintf(stderr, "Accepting point-to-point interface \"%s\"\n",
1129
/* Otherwise, reject non-broadcast-capable devices */
1130
if(not (ifr.ifr_flags & IFF_BROADCAST)){
1132
fprintf(stderr, "Rejecting non-broadcast interface \"%s\"\n",
1137
/* Reject non-ARP interfaces (including dummy interfaces) */
1138
if(ifr.ifr_flags & IFF_NOARP){
1140
fprintf(stderr, "Rejecting non-ARP interface \"%s\"\n",
1145
/* Accept this device */
1147
fprintf(stderr, "Interface \"%s\" is acceptable\n",
1153
int notdotentries(const struct dirent *direntry){
1154
/* Skip "." and ".." */
1155
if(direntry->d_name[0] == '.'
1156
and (direntry->d_name[1] == '\0'
1157
or (direntry->d_name[1] == '.'
1158
and direntry->d_name[2] == '\0'))){
1164
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){
1166
struct timespec now;
1167
struct timespec waited_time;
1168
intmax_t block_time;
1171
if(mc.current_server == NULL){
1174
"Wait until first server is found. No timeout!\n");
1176
ret = avahi_simple_poll_iterate(s, -1);
1179
fprintf(stderr, "Check current_server if we should run it,"
1182
/* the current time */
1183
ret = clock_gettime(CLOCK_MONOTONIC, &now);
1185
perror_plus("clock_gettime");
1188
/* Calculating in ms how long time between now and server
1189
who we visted longest time ago. Now - last seen. */
1190
waited_time.tv_sec = (now.tv_sec
1191
- mc.current_server->last_seen.tv_sec);
1192
waited_time.tv_nsec = (now.tv_nsec
1193
- mc.current_server->last_seen.tv_nsec);
1194
/* total time is 10s/10,000ms.
1195
Converting to s from ms by dividing by 1,000,
1196
and ns to ms by dividing by 1,000,000. */
1197
block_time = ((retry_interval
1198
- ((intmax_t)waited_time.tv_sec * 1000))
1199
- ((intmax_t)waited_time.tv_nsec / 1000000));
1202
fprintf(stderr, "Blocking for %" PRIdMAX " ms\n", block_time);
1205
if(block_time <= 0){
1206
ret = start_mandos_communication(mc.current_server->ip,
1207
mc.current_server->port,
1208
mc.current_server->if_index,
1209
mc.current_server->af);
1211
avahi_simple_poll_quit(mc.simple_poll);
1214
ret = clock_gettime(CLOCK_MONOTONIC,
1215
&mc.current_server->last_seen);
1217
perror_plus("clock_gettime");
1220
mc.current_server = mc.current_server->next;
1221
block_time = 0; /* Call avahi to find new Mandos
1222
servers, but don't block */
1225
ret = avahi_simple_poll_iterate(s, (int)block_time);
1228
if (ret > 0 or errno != EINTR) {
1229
return (ret != 1) ? ret : 0;
880
1235
int main(int argc, char *argv[]){
881
1236
AvahiSServiceBrowser *sb = NULL;
884
1239
intmax_t tmpmax;
886
1241
int exitcode = EXIT_SUCCESS;
887
const char *interface = "eth0";
1242
const char *interface = "";
888
1243
struct ifreq network;
1245
bool take_down_interface = false;
892
char *connect_to = NULL;
893
1248
char tempdir[] = "/tmp/mandosXXXXXX";
894
1249
bool tempdir_created = false;
895
1250
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
896
1251
const char *seckey = PATHDIR "/" SECKEY;
897
1252
const char *pubkey = PATHDIR "/" PUBKEY;
899
/* Initialize Mandos context */
900
mc = (mandos_context){ .simple_poll = NULL, .server = NULL,
901
.dh_bits = 1024, .priority = "SECURE256"
902
":!CTYPE-X.509:+CTYPE-OPENPGP" };
903
1254
bool gnutls_initialized = false;
904
1255
bool gpgme_initialized = false;
907
struct sigaction old_sigterm_action;
1257
double retry_interval = 10; /* 10s between trying a server and
1258
retrying the same server again */
1260
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
908
1261
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
1266
/* Lower any group privileges we might have, just to be safe */
1270
perror_plus("setgid");
1273
/* Lower user privileges (temporarily) */
1277
perror_plus("seteuid");
911
1285
struct argp_option options[] = {
912
1286
{ .name = "debug", .key = 128,
975
1363
mc.priority = arg;
977
1365
case 131: /* --delay */
978
ret = sscanf(arg, "%lf%n", &delay, &numchars);
979
if(ret < 1 or arg[numchars] != '\0'){
980
fprintf(stderr, "Bad delay\n");
1367
delay = strtof(arg, &tmp);
1368
if(errno != 0 or tmp == arg or *tmp != '\0'){
1369
argp_error(state, "Bad delay");
1371
case 132: /* --retry */
1373
retry_interval = strtod(arg, &tmp);
1374
if(errno != 0 or tmp == arg or *tmp != '\0'
1375
or (retry_interval * 1000) > INT_MAX
1376
or retry_interval < 0){
1377
argp_error(state, "Bad retry interval");
1381
* These reproduce what we would get without ARGP_NO_HELP
1383
case '?': /* --help */
1384
argp_state_help(state, state->out_stream,
1385
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
1386
& ~(unsigned int)ARGP_HELP_EXIT_OK);
1387
case -3: /* --usage */
1388
argp_state_help(state, state->out_stream,
1389
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
1390
case 'V': /* --version */
1391
fprintf(state->out_stream, "%s\n", argp_program_version);
1392
exit(argp_err_exit_status);
989
1395
return ARGP_ERR_UNKNOWN;
994
1400
struct argp argp = { .options = options, .parser = parse_opt,
996
1402
.doc = "Mandos client -- Get and decrypt"
997
1403
" passwords from a Mandos server" };
998
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
999
if(ret == ARGP_ERR_UNKNOWN){
1000
fprintf(stderr, "Unknown error while parsing arguments\n");
1404
ret = argp_parse(&argp, argc, argv,
1405
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
1412
perror_plus("argp_parse");
1413
exitcode = EX_OSERR;
1416
exitcode = EX_USAGE;
1422
/* Work around Debian bug #633582:
1423
<http://bugs.debian.org/633582> */
1426
/* Re-raise priviliges */
1430
perror_plus("seteuid");
1433
if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){
1434
int seckey_fd = open(seckey, O_RDONLY);
1435
if(seckey_fd == -1){
1436
perror_plus("open");
1438
ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));
1440
perror_plus("fstat");
1442
if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){
1443
ret = fchown(seckey_fd, uid, gid);
1445
perror_plus("fchown");
1449
TEMP_FAILURE_RETRY(close(seckey_fd));
1453
if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){
1454
int pubkey_fd = open(pubkey, O_RDONLY);
1455
if(pubkey_fd == -1){
1456
perror_plus("open");
1458
ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));
1460
perror_plus("fstat");
1462
if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){
1463
ret = fchown(pubkey_fd, uid, gid);
1465
perror_plus("fchown");
1469
TEMP_FAILURE_RETRY(close(pubkey_fd));
1473
/* Lower privileges */
1477
perror_plus("seteuid");
1482
avahi_set_log_function(empty_log);
1485
if(interface[0] == '\0'){
1486
struct dirent **direntries;
1487
ret = scandir(sys_class_net, &direntries, good_interface,
1490
/* Pick the first good interface */
1491
interface = strdup(direntries[0]->d_name);
1493
fprintf(stderr, "Using interface \"%s\"\n", interface);
1495
if(interface == NULL){
1496
perror_plus("malloc");
1498
exitcode = EXIT_FAILURE;
1504
fprintf(stderr, "Could not find a network interface\n");
1001
1505
exitcode = EXIT_FAILURE;
1510
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
1511
from the signal handler */
1512
/* Initialize the pseudo-RNG for Avahi */
1513
srand((unsigned int) time(NULL));
1514
mc.simple_poll = avahi_simple_poll_new();
1515
if(mc.simple_poll == NULL){
1516
fprintf(stderr, "Avahi: Failed to create simple poll object.\n");
1517
exitcode = EX_UNAVAILABLE;
1521
sigemptyset(&sigterm_action.sa_mask);
1522
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1524
perror_plus("sigaddset");
1525
exitcode = EX_OSERR;
1528
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1530
perror_plus("sigaddset");
1531
exitcode = EX_OSERR;
1534
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1536
perror_plus("sigaddset");
1537
exitcode = EX_OSERR;
1540
/* Need to check if the handler is SIG_IGN before handling:
1541
| [[info:libc:Initial Signal Actions]] |
1542
| [[info:libc:Basic Signal Handling]] |
1544
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1546
perror_plus("sigaction");
1549
if(old_sigterm_action.sa_handler != SIG_IGN){
1550
ret = sigaction(SIGINT, &sigterm_action, NULL);
1552
perror_plus("sigaction");
1553
exitcode = EX_OSERR;
1557
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1559
perror_plus("sigaction");
1562
if(old_sigterm_action.sa_handler != SIG_IGN){
1563
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1565
perror_plus("sigaction");
1566
exitcode = EX_OSERR;
1570
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1572
perror_plus("sigaction");
1575
if(old_sigterm_action.sa_handler != SIG_IGN){
1576
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1578
perror_plus("sigaction");
1579
exitcode = EX_OSERR;
1006
1584
/* If the interface is down, bring it up */
1007
if(interface[0] != '\0'){
1585
if(strcmp(interface, "none") != 0){
1586
if_index = (AvahiIfIndex) if_nametoindex(interface);
1588
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1589
exitcode = EX_UNAVAILABLE;
1597
/* Re-raise priviliges */
1601
perror_plus("seteuid");
1008
1604
#ifdef __linux__
1009
1605
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1010
messages to mess up the prompt */
1606
messages about the network interface to mess up the prompt */
1011
1607
ret = klogctl(8, NULL, 5);
1012
1608
bool restore_loglevel = true;
1014
1610
restore_loglevel = false;
1611
perror_plus("klogctl");
1613
#endif /* __linux__ */
1019
1615
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1022
exitcode = EXIT_FAILURE;
1617
perror_plus("socket");
1618
exitcode = EX_OSERR;
1023
1619
#ifdef __linux__
1024
1620
if(restore_loglevel){
1025
1621
ret = klogctl(7, NULL, 0);
1623
perror_plus("klogctl");
1626
#endif /* __linux__ */
1627
/* Lower privileges */
1631
perror_plus("seteuid");
1033
1635
strcpy(network.ifr_name, interface);
1034
1636
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1036
perror("ioctl SIOCGIFFLAGS");
1638
perror_plus("ioctl SIOCGIFFLAGS");
1037
1639
#ifdef __linux__
1038
1640
if(restore_loglevel){
1039
1641
ret = klogctl(7, NULL, 0);
1643
perror_plus("klogctl");
1045
exitcode = EXIT_FAILURE;
1646
#endif /* __linux__ */
1647
exitcode = EX_OSERR;
1648
/* Lower privileges */
1652
perror_plus("seteuid");
1048
1656
if((network.ifr_flags & IFF_UP) == 0){
1049
1657
network.ifr_flags |= IFF_UP;
1658
take_down_interface = true;
1050
1659
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1052
perror("ioctl SIOCSIFFLAGS");
1053
exitcode = EXIT_FAILURE;
1661
take_down_interface = false;
1662
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1663
exitcode = EX_OSERR;
1054
1664
#ifdef __linux__
1055
1665
if(restore_loglevel){
1056
1666
ret = klogctl(7, NULL, 0);
1668
perror_plus("klogctl");
1671
#endif /* __linux__ */
1672
/* Lower privileges */
1676
perror_plus("seteuid");
1065
/* sleep checking until interface is running */
1681
/* Sleep checking until interface is running.
1682
Check every 0.25s, up to total time of delay */
1066
1683
for(int i=0; i < delay * 4; i++){
1067
1684
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1069
perror("ioctl SIOCGIFFLAGS");
1686
perror_plus("ioctl SIOCGIFFLAGS");
1070
1687
} else if(network.ifr_flags & IFF_RUNNING){
1073
1690
struct timespec sleeptime = { .tv_nsec = 250000000 };
1074
1691
ret = nanosleep(&sleeptime, NULL);
1075
1692
if(ret == -1 and errno != EINTR){
1076
perror("nanosleep");
1693
perror_plus("nanosleep");
1079
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1696
if(not take_down_interface){
1697
/* We won't need the socket anymore */
1698
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1700
perror_plus("close");
1083
1703
#ifdef __linux__
1084
1704
if(restore_loglevel){
1085
1705
/* Restores kernel loglevel to default */
1086
1706
ret = klogctl(7, NULL, 0);
1708
perror_plus("klogctl");
1711
#endif /* __linux__ */
1712
/* Lower privileges */
1714
if(take_down_interface){
1715
/* Lower privileges */
1718
perror_plus("seteuid");
1721
/* Lower privileges permanently */
1724
perror_plus("setuid");
1108
1733
ret = init_gnutls_global(pubkey, seckey);
1110
1735
fprintf(stderr, "init_gnutls_global failed\n");
1111
exitcode = EXIT_FAILURE;
1736
exitcode = EX_UNAVAILABLE;
1114
1739
gnutls_initialized = true;
1117
1746
if(mkdtemp(tempdir) == NULL){
1747
perror_plus("mkdtemp");
1121
1750
tempdir_created = true;
1123
1756
if(not init_gpgme(pubkey, seckey, tempdir)){
1124
1757
fprintf(stderr, "init_gpgme failed\n");
1125
exitcode = EXIT_FAILURE;
1758
exitcode = EX_UNAVAILABLE;
1128
1761
gpgme_initialized = true;
1131
if(interface[0] != '\0'){
1132
if_index = (AvahiIfIndex) if_nametoindex(interface);
1134
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1135
exitcode = EXIT_FAILURE;
1140
1768
if(connect_to != NULL){
1143
1771
char *address = strrchr(connect_to, ':');
1144
1772
if(address == NULL){
1145
1773
fprintf(stderr, "No colon in address\n");
1146
exitcode = EXIT_FAILURE;
1774
exitcode = EX_USAGE;
1150
ret = sscanf(address+1, "%" SCNdMAX "%n", &tmpmax, &numchars);
1151
if(ret < 1 or tmpmax != (uint16_t)tmpmax
1152
or address[numchars+1] != '\0'){
1784
tmpmax = strtoimax(address+1, &tmp, 10);
1785
if(errno != 0 or tmp == address+1 or *tmp != '\0'
1786
or tmpmax != (uint16_t)tmpmax){
1153
1787
fprintf(stderr, "Bad port number\n");
1154
exitcode = EXIT_FAILURE;
1788
exitcode = EX_USAGE;
1157
1796
port = (uint16_t)tmpmax;
1158
1797
*address = '\0';
1159
address = connect_to;
1160
1798
/* Colon in address indicates IPv6 */
1162
if(strchr(address, ':') != NULL){
1800
if(strchr(connect_to, ':') != NULL){
1802
/* Accept [] around IPv6 address - see RFC 5952 */
1803
if(connect_to[0] == '[' and address[-1] == ']')
1167
ret = start_mandos_communication(address, port, if_index, af);
1169
exitcode = EXIT_FAILURE;
1811
address = connect_to;
1817
while(not quit_now){
1818
ret = start_mandos_communication(address, port, if_index, af);
1819
if(quit_now or ret == 0){
1823
fprintf(stderr, "Retrying in %d seconds\n",
1824
(int)retry_interval);
1826
sleep((int)retry_interval);
1171
1830
exitcode = EXIT_SUCCESS;
1177
avahi_set_log_function(empty_log);
1180
/* Initialize the pseudo-RNG for Avahi */
1181
srand((unsigned int) time(NULL));
1183
/* Allocate main Avahi loop object */
1184
mc.simple_poll = avahi_simple_poll_new();
1185
if(mc.simple_poll == NULL){
1186
fprintf(stderr, "Avahi: Failed to create simple poll object.\n");
1187
exitcode = EXIT_FAILURE;