1072
/* Signal handler that stops main loop after SIGTERM */
1073
static void handle_sigterm(int sig){
1078
signal_received = sig;
874
static void handle_sigterm(__attribute__((unused)) int sig){
1079
875
int old_errno = errno;
1080
/* set main loop to exit */
1081
if(mc.simple_poll != NULL){
1082
avahi_simple_poll_quit(mc.simple_poll);
876
avahi_simple_poll_quit(mc.simple_poll);
1084
877
errno = old_errno;
1088
* This function determines if a directory entry in /sys/class/net
1089
* corresponds to an acceptable network device.
1090
* (This function is passed to scandir(3) as a filter function.)
1092
int good_interface(const struct dirent *if_entry){
1094
char *flagname = NULL;
1095
if(if_entry->d_name[0] == '.'){
1098
int ret = asprintf(&flagname, "%s/%s/flags", sys_class_net,
1101
perror_plus("asprintf");
1104
int flags_fd = (int)TEMP_FAILURE_RETRY(open(flagname, O_RDONLY));
1106
perror_plus("open");
1111
typedef short ifreq_flags; /* ifreq.ifr_flags in netdevice(7) */
1112
/* read line from flags_fd */
1113
ssize_t to_read = 2+(sizeof(ifreq_flags)*2)+1; /* "0x1003\n" */
1114
char *flagstring = malloc((size_t)to_read+1); /* +1 for final \0 */
1115
flagstring[(size_t)to_read] = '\0';
1116
if(flagstring == NULL){
1117
perror_plus("malloc");
1122
ssret = (ssize_t)TEMP_FAILURE_RETRY(read(flags_fd, flagstring,
1125
perror_plus("read");
1139
tmpmax = strtoimax(flagstring, &tmp, 0);
1140
if(errno != 0 or tmp == flagstring or (*tmp != '\0'
1141
and not (isspace(*tmp)))
1142
or tmpmax != (ifreq_flags)tmpmax){
1144
fprintf(stderr, "Invalid flags \"%s\" for interface \"%s\"\n",
1145
flagstring, if_entry->d_name);
1151
ifreq_flags flags = (ifreq_flags)tmpmax;
1152
/* Reject the loopback device */
1153
if(flags & IFF_LOOPBACK){
1155
fprintf(stderr, "Rejecting loopback interface \"%s\"\n",
1160
/* Accept point-to-point devices only if connect_to is specified */
1161
if(connect_to != NULL and (flags & IFF_POINTOPOINT)){
1163
fprintf(stderr, "Accepting point-to-point interface \"%s\"\n",
1168
/* Otherwise, reject non-broadcast-capable devices */
1169
if(not (flags & IFF_BROADCAST)){
1171
fprintf(stderr, "Rejecting non-broadcast interface \"%s\"\n",
1176
/* Reject non-ARP interfaces (including dummy interfaces) */
1177
if(flags & IFF_NOARP){
1179
fprintf(stderr, "Rejecting non-ARP interface \"%s\"\n",
1184
/* Accept this device */
1186
fprintf(stderr, "Interface \"%s\" is acceptable\n",
1192
int notdotentries(const struct dirent *direntry){
1193
/* Skip "." and ".." */
1194
if(direntry->d_name[0] == '.'
1195
and (direntry->d_name[1] == '\0'
1196
or (direntry->d_name[1] == '.'
1197
and direntry->d_name[2] == '\0'))){
1203
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){
1205
struct timespec now;
1206
struct timespec waited_time;
1207
intmax_t block_time;
1210
if(mc.current_server == NULL){
1213
"Wait until first server is found. No timeout!\n");
1215
ret = avahi_simple_poll_iterate(s, -1);
1218
fprintf(stderr, "Check current_server if we should run it,"
1221
/* the current time */
1222
ret = clock_gettime(CLOCK_MONOTONIC, &now);
1224
perror_plus("clock_gettime");
1227
/* Calculating in ms how long time between now and server
1228
who we visted longest time ago. Now - last seen. */
1229
waited_time.tv_sec = (now.tv_sec
1230
- mc.current_server->last_seen.tv_sec);
1231
waited_time.tv_nsec = (now.tv_nsec
1232
- mc.current_server->last_seen.tv_nsec);
1233
/* total time is 10s/10,000ms.
1234
Converting to s from ms by dividing by 1,000,
1235
and ns to ms by dividing by 1,000,000. */
1236
block_time = ((retry_interval
1237
- ((intmax_t)waited_time.tv_sec * 1000))
1238
- ((intmax_t)waited_time.tv_nsec / 1000000));
1241
fprintf(stderr, "Blocking for %ld ms\n", block_time);
1244
if(block_time <= 0){
1245
ret = start_mandos_communication(mc.current_server->ip,
1246
mc.current_server->port,
1247
mc.current_server->if_index,
1248
mc.current_server->af);
1250
avahi_simple_poll_quit(mc.simple_poll);
1253
ret = clock_gettime(CLOCK_MONOTONIC,
1254
&mc.current_server->last_seen);
1256
perror_plus("clock_gettime");
1259
mc.current_server = mc.current_server->next;
1260
block_time = 0; /* Call avahi to find new Mandos
1261
servers, but don't block */
1264
ret = avahi_simple_poll_iterate(s, (int)block_time);
1267
if (ret > 0 or errno != EINTR) {
1268
return (ret != 1) ? ret : 0;
1274
880
int main(int argc, char *argv[]){
1275
881
AvahiSServiceBrowser *sb = NULL;
1278
884
intmax_t tmpmax;
1280
886
int exitcode = EXIT_SUCCESS;
1281
const char *interface = "";
887
const char *interface = "eth0";
1282
888
struct ifreq network;
1284
bool take_down_interface = false;
892
char *connect_to = NULL;
1287
893
char tempdir[] = "/tmp/mandosXXXXXX";
1288
894
bool tempdir_created = false;
1289
895
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
1290
896
const char *seckey = PATHDIR "/" SECKEY;
1291
897
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" };
1293
903
bool gnutls_initialized = false;
1294
904
bool gpgme_initialized = false;
1296
double retry_interval = 10; /* 10s between trying a server and
1297
retrying the same server again */
1299
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
907
struct sigaction old_sigterm_action;
1300
908
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
1305
/* Lower any group privileges we might have, just to be safe */
1309
perror_plus("setgid");
1312
/* Lower user privileges (temporarily) */
1316
perror_plus("seteuid");
1324
911
struct argp_option options[] = {
1325
912
{ .name = "debug", .key = 128,
1402
975
mc.priority = arg;
1404
977
case 131: /* --delay */
1406
delay = strtof(arg, &tmp);
1407
if(errno != 0 or tmp == arg or *tmp != '\0'){
1408
argp_error(state, "Bad delay");
1410
case 132: /* --retry */
1412
retry_interval = strtod(arg, &tmp);
1413
if(errno != 0 or tmp == arg or *tmp != '\0'
1414
or (retry_interval * 1000) > INT_MAX){
1415
argp_error(state, "Bad retry interval");
978
ret = sscanf(arg, "%lf%n", &delay, &numchars);
979
if(ret < 1 or arg[numchars] != '\0'){
980
fprintf(stderr, "Bad delay\n");
1419
* These reproduce what we would get without ARGP_NO_HELP
1421
case '?': /* --help */
1422
argp_state_help(state, state->out_stream,
1423
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
1424
& ~(unsigned int)ARGP_HELP_EXIT_OK);
1425
case -3: /* --usage */
1426
argp_state_help(state, state->out_stream,
1427
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
1428
case 'V': /* --version */
1429
fprintf(state->out_stream, "%s\n", argp_program_version);
1430
exit(argp_err_exit_status);
1433
989
return ARGP_ERR_UNKNOWN;
1438
994
struct argp argp = { .options = options, .parser = parse_opt,
1440
996
.doc = "Mandos client -- Get and decrypt"
1441
997
" passwords from a Mandos server" };
1442
ret = argp_parse(&argp, argc, argv,
1443
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
1450
perror_plus("argp_parse");
1451
exitcode = EX_OSERR;
1454
exitcode = EX_USAGE;
1460
/* Work around Debian bug #633582:
1461
<http://bugs.debian.org/633582> */
1464
/* Re-raise priviliges */
1468
perror_plus("seteuid");
1471
int seckey_fd = open(PATHDIR "/" SECKEY, O_RDONLY);
1472
if(seckey_fd == -1){
1473
perror_plus("open");
1475
ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));
1477
perror_plus("fstat");
1479
if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){
1480
ret = fchown(seckey_fd, uid, gid);
1482
perror_plus("fchown");
1486
TEMP_FAILURE_RETRY(close(seckey_fd));
1489
int pubkey_fd = open(PATHDIR "/" PUBKEY, O_RDONLY);
1490
if(pubkey_fd == -1){
1491
perror_plus("open");
1493
ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));
1495
perror_plus("fstat");
1497
if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){
1498
ret = fchown(pubkey_fd, uid, gid);
1500
perror_plus("fchown");
1504
TEMP_FAILURE_RETRY(close(pubkey_fd));
1507
/* Lower privileges */
1511
perror_plus("seteuid");
1516
avahi_set_log_function(empty_log);
1519
if(interface[0] == '\0'){
1520
struct dirent **direntries;
1521
ret = scandir(sys_class_net, &direntries, good_interface,
1524
/* Pick the first good interface */
1525
interface = strdup(direntries[0]->d_name);
1527
fprintf(stderr, "Using interface \"%s\"\n", interface);
1529
if(interface == NULL){
1530
perror_plus("malloc");
1532
exitcode = EXIT_FAILURE;
1538
fprintf(stderr, "Could not find a network interface\n");
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");
1539
1001
exitcode = EXIT_FAILURE;
1544
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
1545
from the signal handler */
1546
/* Initialize the pseudo-RNG for Avahi */
1547
srand((unsigned int) time(NULL));
1548
mc.simple_poll = avahi_simple_poll_new();
1549
if(mc.simple_poll == NULL){
1550
fprintf(stderr, "Avahi: Failed to create simple poll object.\n");
1551
exitcode = EX_UNAVAILABLE;
1555
sigemptyset(&sigterm_action.sa_mask);
1556
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1558
perror_plus("sigaddset");
1559
exitcode = EX_OSERR;
1562
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1564
perror_plus("sigaddset");
1565
exitcode = EX_OSERR;
1568
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1570
perror_plus("sigaddset");
1571
exitcode = EX_OSERR;
1574
/* Need to check if the handler is SIG_IGN before handling:
1575
| [[info:libc:Initial Signal Actions]] |
1576
| [[info:libc:Basic Signal Handling]] |
1578
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1580
perror_plus("sigaction");
1583
if(old_sigterm_action.sa_handler != SIG_IGN){
1584
ret = sigaction(SIGINT, &sigterm_action, NULL);
1586
perror_plus("sigaction");
1587
exitcode = EX_OSERR;
1591
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1593
perror_plus("sigaction");
1596
if(old_sigterm_action.sa_handler != SIG_IGN){
1597
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1599
perror_plus("sigaction");
1600
exitcode = EX_OSERR;
1604
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1606
perror_plus("sigaction");
1609
if(old_sigterm_action.sa_handler != SIG_IGN){
1610
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1612
perror_plus("sigaction");
1613
exitcode = EX_OSERR;
1618
1006
/* If the interface is down, bring it up */
1619
if(strcmp(interface, "none") != 0){
1620
if_index = (AvahiIfIndex) if_nametoindex(interface);
1622
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1623
exitcode = EX_UNAVAILABLE;
1631
/* Re-raise priviliges */
1635
perror_plus("seteuid");
1007
if(interface[0] != '\0'){
1638
1008
#ifdef __linux__
1639
1009
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1640
messages about the network interface to mess up the prompt */
1010
messages to mess up the prompt */
1641
1011
ret = klogctl(8, NULL, 5);
1642
1012
bool restore_loglevel = true;
1644
1014
restore_loglevel = false;
1645
perror_plus("klogctl");
1647
#endif /* __linux__ */
1649
1019
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1651
perror_plus("socket");
1652
exitcode = EX_OSERR;
1022
exitcode = EXIT_FAILURE;
1653
1023
#ifdef __linux__
1654
1024
if(restore_loglevel){
1655
1025
ret = klogctl(7, NULL, 0);
1657
perror_plus("klogctl");
1660
#endif /* __linux__ */
1661
/* Lower privileges */
1665
perror_plus("seteuid");
1669
1033
strcpy(network.ifr_name, interface);
1670
1034
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1672
perror_plus("ioctl SIOCGIFFLAGS");
1036
perror("ioctl SIOCGIFFLAGS");
1673
1037
#ifdef __linux__
1674
1038
if(restore_loglevel){
1675
1039
ret = klogctl(7, NULL, 0);
1677
perror_plus("klogctl");
1680
#endif /* __linux__ */
1681
exitcode = EX_OSERR;
1682
/* Lower privileges */
1686
perror_plus("seteuid");
1045
exitcode = EXIT_FAILURE;
1690
1048
if((network.ifr_flags & IFF_UP) == 0){
1691
1049
network.ifr_flags |= IFF_UP;
1692
take_down_interface = true;
1693
1050
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1695
take_down_interface = false;
1696
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1697
exitcode = EX_OSERR;
1052
perror("ioctl SIOCSIFFLAGS");
1053
exitcode = EXIT_FAILURE;
1698
1054
#ifdef __linux__
1699
1055
if(restore_loglevel){
1700
1056
ret = klogctl(7, NULL, 0);
1702
perror_plus("klogctl");
1705
#endif /* __linux__ */
1706
/* Lower privileges */
1710
perror_plus("seteuid");
1715
/* Sleep checking until interface is running.
1716
Check every 0.25s, up to total time of delay */
1065
/* sleep checking until interface is running */
1717
1066
for(int i=0; i < delay * 4; i++){
1718
1067
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1720
perror_plus("ioctl SIOCGIFFLAGS");
1069
perror("ioctl SIOCGIFFLAGS");
1721
1070
} else if(network.ifr_flags & IFF_RUNNING){
1724
1073
struct timespec sleeptime = { .tv_nsec = 250000000 };
1725
1074
ret = nanosleep(&sleeptime, NULL);
1726
1075
if(ret == -1 and errno != EINTR){
1727
perror_plus("nanosleep");
1076
perror("nanosleep");
1730
if(not take_down_interface){
1731
/* We won't need the socket anymore */
1732
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1734
perror_plus("close");
1079
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1737
1083
#ifdef __linux__
1738
1084
if(restore_loglevel){
1739
1085
/* Restores kernel loglevel to default */
1740
1086
ret = klogctl(7, NULL, 0);
1742
perror_plus("klogctl");
1745
#endif /* __linux__ */
1746
/* Lower privileges */
1748
if(take_down_interface){
1749
/* Lower privileges */
1752
perror_plus("seteuid");
1755
/* Lower privileges permanently */
1758
perror_plus("setuid");
1767
1108
ret = init_gnutls_global(pubkey, seckey);
1769
1110
fprintf(stderr, "init_gnutls_global failed\n");
1770
exitcode = EX_UNAVAILABLE;
1111
exitcode = EXIT_FAILURE;
1773
1114
gnutls_initialized = true;
1780
1117
if(mkdtemp(tempdir) == NULL){
1781
perror_plus("mkdtemp");
1784
1121
tempdir_created = true;
1790
1123
if(not init_gpgme(pubkey, seckey, tempdir)){
1791
1124
fprintf(stderr, "init_gpgme failed\n");
1792
exitcode = EX_UNAVAILABLE;
1125
exitcode = EXIT_FAILURE;
1795
1128
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;
1802
1140
if(connect_to != NULL){