1073
/* Signal handler that stops main loop after SIGTERM */
1074
static void handle_sigterm(int sig){
1079
signal_received = sig;
1080
int old_errno = errno;
1081
/* set main loop to exit */
1082
if(mc.simple_poll != NULL){
1083
avahi_simple_poll_quit(mc.simple_poll);
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){
1095
char *flagname = NULL;
1096
if(if_entry->d_name[0] == '.'){
1099
int ret = asprintf(&flagname, "%s/%s/flags", sys_class_net,
1102
perror_plus("asprintf");
1105
int flags_fd = (int)TEMP_FAILURE_RETRY(open(flagname, O_RDONLY));
1107
perror_plus("open");
1112
typedef short ifreq_flags; /* ifreq.ifr_flags in netdevice(7) */
1113
/* read line from flags_fd */
1114
ssize_t to_read = 2+(sizeof(ifreq_flags)*2)+1; /* "0x1003\n" */
1115
char *flagstring = malloc((size_t)to_read+1); /* +1 for final \0 */
1116
flagstring[(size_t)to_read] = '\0';
1117
if(flagstring == NULL){
1118
perror_plus("malloc");
1123
ssret = (ssize_t)TEMP_FAILURE_RETRY(read(flags_fd, flagstring,
1126
perror_plus("read");
1140
tmpmax = strtoimax(flagstring, &tmp, 0);
1141
if(errno != 0 or tmp == flagstring or (*tmp != '\0'
1142
and not (isspace(*tmp)))
1143
or tmpmax != (ifreq_flags)tmpmax){
1145
fprintf(stderr, "Invalid flags \"%s\" for interface \"%s\"\n",
1146
flagstring, if_entry->d_name);
1152
ifreq_flags flags = (ifreq_flags)tmpmax;
1153
/* Reject the loopback device */
1154
if(flags & IFF_LOOPBACK){
1156
fprintf(stderr, "Rejecting loopback interface \"%s\"\n",
1161
/* Accept point-to-point devices only if connect_to is specified */
1162
if(connect_to != NULL and (flags & IFF_POINTOPOINT)){
1164
fprintf(stderr, "Accepting point-to-point interface \"%s\"\n",
1169
/* Otherwise, reject non-broadcast-capable devices */
1170
if(not (flags & IFF_BROADCAST)){
1172
fprintf(stderr, "Rejecting non-broadcast interface \"%s\"\n",
1177
/* Reject non-ARP interfaces (including dummy interfaces) */
1178
if(flags & IFF_NOARP){
1180
fprintf(stderr, "Rejecting non-ARP interface \"%s\"\n",
1185
/* Accept this device */
1187
fprintf(stderr, "Interface \"%s\" is acceptable\n",
1193
int notdotentries(const struct dirent *direntry){
1194
/* Skip "." and ".." */
1195
if(direntry->d_name[0] == '.'
1196
and (direntry->d_name[1] == '\0'
1197
or (direntry->d_name[1] == '.'
1198
and direntry->d_name[2] == '\0'))){
1204
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){
1206
struct timespec now;
1207
struct timespec waited_time;
1208
intmax_t block_time;
1211
if(mc.current_server == NULL){
1214
"Wait until first server is found. No timeout!\n");
1216
ret = avahi_simple_poll_iterate(s, -1);
1219
fprintf(stderr, "Check current_server if we should run it,"
1222
/* the current time */
1223
ret = clock_gettime(CLOCK_MONOTONIC, &now);
1225
perror_plus("clock_gettime");
1228
/* Calculating in ms how long time between now and server
1229
who we visted longest time ago. Now - last seen. */
1230
waited_time.tv_sec = (now.tv_sec
1231
- mc.current_server->last_seen.tv_sec);
1232
waited_time.tv_nsec = (now.tv_nsec
1233
- mc.current_server->last_seen.tv_nsec);
1234
/* total time is 10s/10,000ms.
1235
Converting to s from ms by dividing by 1,000,
1236
and ns to ms by dividing by 1,000,000. */
1237
block_time = ((retry_interval
1238
- ((intmax_t)waited_time.tv_sec * 1000))
1239
- ((intmax_t)waited_time.tv_nsec / 1000000));
1242
fprintf(stderr, "Blocking for %" PRIdMAX " ms\n", block_time);
1245
if(block_time <= 0){
1246
ret = start_mandos_communication(mc.current_server->ip,
1247
mc.current_server->port,
1248
mc.current_server->if_index,
1249
mc.current_server->af);
1251
avahi_simple_poll_quit(mc.simple_poll);
1254
ret = clock_gettime(CLOCK_MONOTONIC,
1255
&mc.current_server->last_seen);
1257
perror_plus("clock_gettime");
1260
mc.current_server = mc.current_server->next;
1261
block_time = 0; /* Call avahi to find new Mandos
1262
servers, but don't block */
1265
ret = avahi_simple_poll_iterate(s, (int)block_time);
1268
if (ret > 0 or errno != EINTR) {
1269
return (ret != 1) ? ret : 0;
873
1275
int main(int argc, char *argv[]){
874
1276
AvahiSServiceBrowser *sb = NULL;
877
1279
intmax_t tmpmax;
879
1281
int exitcode = EXIT_SUCCESS;
880
const char *interface = "eth0";
1282
const char *interface = "";
881
1283
struct ifreq network;
1285
bool take_down_interface = false;
885
char *connect_to = NULL;
886
1288
char tempdir[] = "/tmp/mandosXXXXXX";
887
1289
bool tempdir_created = false;
888
1290
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
889
1291
const char *seckey = PATHDIR "/" SECKEY;
890
1292
const char *pubkey = PATHDIR "/" PUBKEY;
892
mandos_context mc = { .simple_poll = NULL, .server = NULL,
893
.dh_bits = 1024, .priority = "SECURE256"
894
":!CTYPE-X.509:+CTYPE-OPENPGP" };
895
1294
bool gnutls_initialized = false;
896
1295
bool gpgme_initialized = false;
1297
double retry_interval = 10; /* 10s between trying a server and
1298
retrying the same server again */
1300
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
1301
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
1306
/* Lower any group privileges we might have, just to be safe */
1310
perror_plus("setgid");
1313
/* Lower user privileges (temporarily) */
1317
perror_plus("seteuid");
900
1325
struct argp_option options[] = {
964
1403
mc.priority = arg;
966
1405
case 131: /* --delay */
967
ret = sscanf(arg, "%lf%n", &delay, &numchars);
968
if(ret < 1 or arg[numchars] != '\0'){
969
fprintf(stderr, "Bad delay\n");
1407
delay = strtof(arg, &tmp);
1408
if(errno != 0 or tmp == arg or *tmp != '\0'){
1409
argp_error(state, "Bad delay");
1411
case 132: /* --retry */
1413
retry_interval = strtod(arg, &tmp);
1414
if(errno != 0 or tmp == arg or *tmp != '\0'
1415
or (retry_interval * 1000) > INT_MAX
1416
or retry_interval < 0){
1417
argp_error(state, "Bad retry interval");
1421
* These reproduce what we would get without ARGP_NO_HELP
1423
case '?': /* --help */
1424
argp_state_help(state, state->out_stream,
1425
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
1426
& ~(unsigned int)ARGP_HELP_EXIT_OK);
1427
case -3: /* --usage */
1428
argp_state_help(state, state->out_stream,
1429
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
1430
case 'V': /* --version */
1431
fprintf(state->out_stream, "%s\n", argp_program_version);
1432
exit(argp_err_exit_status);
978
1435
return ARGP_ERR_UNKNOWN;
983
1440
struct argp argp = { .options = options, .parser = parse_opt,
985
1442
.doc = "Mandos client -- Get and decrypt"
986
1443
" passwords from a Mandos server" };
987
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
988
if(ret == ARGP_ERR_UNKNOWN){
989
fprintf(stderr, "Unknown error while parsing arguments\n");
1444
ret = argp_parse(&argp, argc, argv,
1445
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
1452
perror_plus("argp_parse");
1453
exitcode = EX_OSERR;
1456
exitcode = EX_USAGE;
1462
/* Work around Debian bug #633582:
1463
<http://bugs.debian.org/633582> */
1466
/* Re-raise priviliges */
1470
perror_plus("seteuid");
1473
if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){
1474
int seckey_fd = open(seckey, O_RDONLY);
1475
if(seckey_fd == -1){
1476
perror_plus("open");
1478
ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));
1480
perror_plus("fstat");
1482
if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){
1483
ret = fchown(seckey_fd, uid, gid);
1485
perror_plus("fchown");
1489
TEMP_FAILURE_RETRY(close(seckey_fd));
1493
if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){
1494
int pubkey_fd = open(pubkey, O_RDONLY);
1495
if(pubkey_fd == -1){
1496
perror_plus("open");
1498
ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));
1500
perror_plus("fstat");
1502
if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){
1503
ret = fchown(pubkey_fd, uid, gid);
1505
perror_plus("fchown");
1509
TEMP_FAILURE_RETRY(close(pubkey_fd));
1513
/* Lower privileges */
1517
perror_plus("seteuid");
1522
avahi_set_log_function(empty_log);
1525
if(interface[0] == '\0'){
1526
struct dirent **direntries;
1527
ret = scandir(sys_class_net, &direntries, good_interface,
1530
/* Pick the first good interface */
1531
interface = strdup(direntries[0]->d_name);
1533
fprintf(stderr, "Using interface \"%s\"\n", interface);
1535
if(interface == NULL){
1536
perror_plus("malloc");
1538
exitcode = EXIT_FAILURE;
1544
fprintf(stderr, "Could not find a network interface\n");
990
1545
exitcode = EXIT_FAILURE;
1550
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
1551
from the signal handler */
1552
/* Initialize the pseudo-RNG for Avahi */
1553
srand((unsigned int) time(NULL));
1554
mc.simple_poll = avahi_simple_poll_new();
1555
if(mc.simple_poll == NULL){
1556
fprintf(stderr, "Avahi: Failed to create simple poll object.\n");
1557
exitcode = EX_UNAVAILABLE;
1561
sigemptyset(&sigterm_action.sa_mask);
1562
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1564
perror_plus("sigaddset");
1565
exitcode = EX_OSERR;
1568
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1570
perror_plus("sigaddset");
1571
exitcode = EX_OSERR;
1574
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1576
perror_plus("sigaddset");
1577
exitcode = EX_OSERR;
1580
/* Need to check if the handler is SIG_IGN before handling:
1581
| [[info:libc:Initial Signal Actions]] |
1582
| [[info:libc:Basic Signal Handling]] |
1584
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1586
perror_plus("sigaction");
1589
if(old_sigterm_action.sa_handler != SIG_IGN){
1590
ret = sigaction(SIGINT, &sigterm_action, NULL);
1592
perror_plus("sigaction");
1593
exitcode = EX_OSERR;
1597
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1599
perror_plus("sigaction");
1602
if(old_sigterm_action.sa_handler != SIG_IGN){
1603
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1605
perror_plus("sigaction");
1606
exitcode = EX_OSERR;
1610
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1612
perror_plus("sigaction");
1615
if(old_sigterm_action.sa_handler != SIG_IGN){
1616
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1618
perror_plus("sigaction");
1619
exitcode = EX_OSERR;
995
1624
/* If the interface is down, bring it up */
996
if(interface[0] != '\0'){
1625
if(strcmp(interface, "none") != 0){
1626
if_index = (AvahiIfIndex) if_nametoindex(interface);
1628
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1629
exitcode = EX_UNAVAILABLE;
1637
/* Re-raise priviliges */
1641
perror_plus("seteuid");
997
1644
#ifdef __linux__
998
1645
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
999
messages to mess up the prompt */
1646
messages about the network interface to mess up the prompt */
1000
1647
ret = klogctl(8, NULL, 5);
1001
1648
bool restore_loglevel = true;
1003
1650
restore_loglevel = false;
1651
perror_plus("klogctl");
1653
#endif /* __linux__ */
1008
1655
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1011
exitcode = EXIT_FAILURE;
1657
perror_plus("socket");
1658
exitcode = EX_OSERR;
1012
1659
#ifdef __linux__
1013
1660
if(restore_loglevel){
1014
1661
ret = klogctl(7, NULL, 0);
1663
perror_plus("klogctl");
1666
#endif /* __linux__ */
1667
/* Lower privileges */
1671
perror_plus("seteuid");
1022
1675
strcpy(network.ifr_name, interface);
1023
1676
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1025
perror("ioctl SIOCGIFFLAGS");
1678
perror_plus("ioctl SIOCGIFFLAGS");
1026
1679
#ifdef __linux__
1027
1680
if(restore_loglevel){
1028
1681
ret = klogctl(7, NULL, 0);
1683
perror_plus("klogctl");
1034
exitcode = EXIT_FAILURE;
1686
#endif /* __linux__ */
1687
exitcode = EX_OSERR;
1688
/* Lower privileges */
1692
perror_plus("seteuid");
1037
1696
if((network.ifr_flags & IFF_UP) == 0){
1038
1697
network.ifr_flags |= IFF_UP;
1698
take_down_interface = true;
1039
1699
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1041
perror("ioctl SIOCSIFFLAGS");
1042
exitcode = EXIT_FAILURE;
1701
take_down_interface = false;
1702
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1703
exitcode = EX_OSERR;
1043
1704
#ifdef __linux__
1044
1705
if(restore_loglevel){
1045
1706
ret = klogctl(7, NULL, 0);
1708
perror_plus("klogctl");
1711
#endif /* __linux__ */
1712
/* Lower privileges */
1716
perror_plus("seteuid");
1054
/* sleep checking until interface is running */
1721
/* Sleep checking until interface is running.
1722
Check every 0.25s, up to total time of delay */
1055
1723
for(int i=0; i < delay * 4; i++){
1056
1724
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1058
perror("ioctl SIOCGIFFLAGS");
1726
perror_plus("ioctl SIOCGIFFLAGS");
1059
1727
} else if(network.ifr_flags & IFF_RUNNING){
1062
1730
struct timespec sleeptime = { .tv_nsec = 250000000 };
1063
1731
ret = nanosleep(&sleeptime, NULL);
1064
1732
if(ret == -1 and errno != EINTR){
1065
perror("nanosleep");
1733
perror_plus("nanosleep");
1068
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1736
if(not take_down_interface){
1737
/* We won't need the socket anymore */
1738
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1740
perror_plus("close");
1072
1743
#ifdef __linux__
1073
1744
if(restore_loglevel){
1074
1745
/* Restores kernel loglevel to default */
1075
1746
ret = klogctl(7, NULL, 0);
1097
ret = init_gnutls_global(&mc, pubkey, seckey);
1748
perror_plus("klogctl");
1751
#endif /* __linux__ */
1752
/* Lower privileges */
1754
if(take_down_interface){
1755
/* Lower privileges */
1758
perror_plus("seteuid");
1761
/* Lower privileges permanently */
1764
perror_plus("setuid");
1773
ret = init_gnutls_global(pubkey, seckey);
1099
1775
fprintf(stderr, "init_gnutls_global failed\n");
1100
exitcode = EXIT_FAILURE;
1776
exitcode = EX_UNAVAILABLE;
1103
1779
gnutls_initialized = true;
1106
1786
if(mkdtemp(tempdir) == NULL){
1787
perror_plus("mkdtemp");
1110
1790
tempdir_created = true;
1112
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
1796
if(not init_gpgme(pubkey, seckey, tempdir)){
1113
1797
fprintf(stderr, "init_gpgme failed\n");
1114
exitcode = EXIT_FAILURE;
1798
exitcode = EX_UNAVAILABLE;
1117
1801
gpgme_initialized = true;
1120
if(interface[0] != '\0'){
1121
if_index = (AvahiIfIndex) if_nametoindex(interface);
1123
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1124
exitcode = EXIT_FAILURE;
1129
1808
if(connect_to != NULL){
1132
1811
char *address = strrchr(connect_to, ':');
1133
1812
if(address == NULL){
1134
1813
fprintf(stderr, "No colon in address\n");
1135
exitcode = EXIT_FAILURE;
1814
exitcode = EX_USAGE;
1139
ret = sscanf(address+1, "%" SCNdMAX "%n", &tmpmax, &numchars);
1140
if(ret < 1 or tmpmax != (uint16_t)tmpmax
1141
or address[numchars+1] != '\0'){
1824
tmpmax = strtoimax(address+1, &tmp, 10);
1825
if(errno != 0 or tmp == address+1 or *tmp != '\0'
1826
or tmpmax != (uint16_t)tmpmax){
1142
1827
fprintf(stderr, "Bad port number\n");
1143
exitcode = EXIT_FAILURE;
1828
exitcode = EX_USAGE;
1146
1836
port = (uint16_t)tmpmax;
1147
1837
*address = '\0';
1148
address = connect_to;
1149
1838
/* Colon in address indicates IPv6 */
1151
if(strchr(address, ':') != NULL){
1840
if(strchr(connect_to, ':') != NULL){
1842
/* Accept [] around IPv6 address - see RFC 5952 */
1843
if(connect_to[0] == '[' and address[-1] == ']')
1156
ret = start_mandos_communication(address, port, if_index, &mc,
1159
exitcode = EXIT_FAILURE;
1851
address = connect_to;
1857
while(not quit_now){
1858
ret = start_mandos_communication(address, port, if_index, af);
1859
if(quit_now or ret == 0){
1863
fprintf(stderr, "Retrying in %d seconds\n",
1864
(int)retry_interval);
1866
sleep((int)retry_interval);
1161
1870
exitcode = EXIT_SUCCESS;
1167
avahi_set_log_function(empty_log);
1170
/* Initialize the pseudo-RNG for Avahi */
1171
srand((unsigned int) time(NULL));
1173
/* Allocate main Avahi loop object */
1174
mc.simple_poll = avahi_simple_poll_new();
1175
if(mc.simple_poll == NULL){
1176
fprintf(stderr, "Avahi: Failed to create simple poll object.\n");
1177
exitcode = EXIT_FAILURE;