811
1160
case AVAHI_BROWSER_ALL_FOR_NOW:
812
1161
case AVAHI_BROWSER_CACHE_EXHAUSTED:
814
fprintf(stderr, "No Mandos server found, still searching...\n");
1163
fprintf_plus(stderr, "No Mandos server found, still"
1170
/* Signal handler that stops main loop after SIGTERM */
1171
static void handle_sigterm(int sig){
1176
signal_received = sig;
1177
int old_errno = errno;
1178
/* set main loop to exit */
1179
if(simple_poll != NULL){
1180
avahi_simple_poll_quit(simple_poll);
1185
__attribute__((nonnull, warn_unused_result))
1186
bool get_flags(const char *ifname, struct ifreq *ifr){
1190
int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1193
perror_plus("socket");
1197
strcpy(ifr->ifr_name, ifname);
1198
ret = ioctl(s, SIOCGIFFLAGS, ifr);
1202
perror_plus("ioctl SIOCGIFFLAGS");
1210
__attribute__((nonnull, warn_unused_result))
1211
bool good_flags(const char *ifname, const struct ifreq *ifr){
1213
/* Reject the loopback device */
1214
if(ifr->ifr_flags & IFF_LOOPBACK){
1216
fprintf_plus(stderr, "Rejecting loopback interface \"%s\"\n",
1221
/* Accept point-to-point devices only if connect_to is specified */
1222
if(connect_to != NULL and (ifr->ifr_flags & IFF_POINTOPOINT)){
1224
fprintf_plus(stderr, "Accepting point-to-point interface"
1225
" \"%s\"\n", ifname);
1229
/* Otherwise, reject non-broadcast-capable devices */
1230
if(not (ifr->ifr_flags & IFF_BROADCAST)){
1232
fprintf_plus(stderr, "Rejecting non-broadcast interface"
1233
" \"%s\"\n", ifname);
1237
/* Reject non-ARP interfaces (including dummy interfaces) */
1238
if(ifr->ifr_flags & IFF_NOARP){
1240
fprintf_plus(stderr, "Rejecting non-ARP interface \"%s\"\n",
1246
/* Accept this device */
1248
fprintf_plus(stderr, "Interface \"%s\" is good\n", ifname);
1254
* This function determines if a directory entry in /sys/class/net
1255
* corresponds to an acceptable network device.
1256
* (This function is passed to scandir(3) as a filter function.)
1258
__attribute__((nonnull, warn_unused_result))
1259
int good_interface(const struct dirent *if_entry){
1260
if(if_entry->d_name[0] == '.'){
1265
if(not get_flags(if_entry->d_name, &ifr)){
1267
fprintf_plus(stderr, "Failed to get flags for interface "
1268
"\"%s\"\n", if_entry->d_name);
1273
if(not good_flags(if_entry->d_name, &ifr)){
1280
* This function determines if a network interface is up.
1282
__attribute__((nonnull, warn_unused_result))
1283
bool interface_is_up(const char *interface){
1285
if(not get_flags(interface, &ifr)){
1287
fprintf_plus(stderr, "Failed to get flags for interface "
1288
"\"%s\"\n", interface);
1293
return (bool)(ifr.ifr_flags & IFF_UP);
1297
* This function determines if a network interface is running
1299
__attribute__((nonnull, warn_unused_result))
1300
bool interface_is_running(const char *interface){
1302
if(not get_flags(interface, &ifr)){
1304
fprintf_plus(stderr, "Failed to get flags for interface "
1305
"\"%s\"\n", interface);
1310
return (bool)(ifr.ifr_flags & IFF_RUNNING);
1313
__attribute__((nonnull, pure, warn_unused_result))
1314
int notdotentries(const struct dirent *direntry){
1315
/* Skip "." and ".." */
1316
if(direntry->d_name[0] == '.'
1317
and (direntry->d_name[1] == '\0'
1318
or (direntry->d_name[1] == '.'
1319
and direntry->d_name[2] == '\0'))){
1325
/* Is this directory entry a runnable program? */
1326
__attribute__((nonnull, warn_unused_result))
1327
int runnable_hook(const struct dirent *direntry){
1332
if((direntry->d_name)[0] == '\0'){
1337
sret = strspn(direntry->d_name, "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
1338
"abcdefghijklmnopqrstuvwxyz"
1341
if((direntry->d_name)[sret] != '\0'){
1342
/* Contains non-allowed characters */
1344
fprintf_plus(stderr, "Ignoring hook \"%s\" with bad name\n",
1350
ret = fstatat(hookdir_fd, direntry->d_name, &st, 0);
1353
perror_plus("Could not stat hook");
1357
if(not (S_ISREG(st.st_mode))){
1358
/* Not a regular file */
1360
fprintf_plus(stderr, "Ignoring hook \"%s\" - not a file\n",
1365
if(not (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))){
1366
/* Not executable */
1368
fprintf_plus(stderr, "Ignoring hook \"%s\" - not executable\n",
1374
fprintf_plus(stderr, "Hook \"%s\" is acceptable\n",
1380
__attribute__((nonnull, warn_unused_result))
1381
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,
1382
mandos_context *mc){
1384
struct timespec now;
1385
struct timespec waited_time;
1386
intmax_t block_time;
1389
if(mc->current_server == NULL){
1391
fprintf_plus(stderr, "Wait until first server is found."
1394
ret = avahi_simple_poll_iterate(s, -1);
1397
fprintf_plus(stderr, "Check current_server if we should run"
1400
/* the current time */
1401
ret = clock_gettime(CLOCK_MONOTONIC, &now);
1403
perror_plus("clock_gettime");
1406
/* Calculating in ms how long time between now and server
1407
who we visted longest time ago. Now - last seen. */
1408
waited_time.tv_sec = (now.tv_sec
1409
- mc->current_server->last_seen.tv_sec);
1410
waited_time.tv_nsec = (now.tv_nsec
1411
- mc->current_server->last_seen.tv_nsec);
1412
/* total time is 10s/10,000ms.
1413
Converting to s from ms by dividing by 1,000,
1414
and ns to ms by dividing by 1,000,000. */
1415
block_time = ((retry_interval
1416
- ((intmax_t)waited_time.tv_sec * 1000))
1417
- ((intmax_t)waited_time.tv_nsec / 1000000));
1420
fprintf_plus(stderr, "Blocking for %" PRIdMAX " ms\n",
1424
if(block_time <= 0){
1425
ret = start_mandos_communication(mc->current_server->ip,
1426
mc->current_server->port,
1427
mc->current_server->if_index,
1428
mc->current_server->af, mc);
1430
avahi_simple_poll_quit(s);
1433
ret = clock_gettime(CLOCK_MONOTONIC,
1434
&mc->current_server->last_seen);
1436
perror_plus("clock_gettime");
1439
mc->current_server = mc->current_server->next;
1440
block_time = 0; /* Call avahi to find new Mandos
1441
servers, but don't block */
1444
ret = avahi_simple_poll_iterate(s, (int)block_time);
1447
if(ret > 0 or errno != EINTR){
1448
return (ret != 1) ? ret : 0;
1454
/* Set effective uid to 0, return errno */
1455
__attribute__((warn_unused_result))
1456
error_t raise_privileges(void){
1457
error_t old_errno = errno;
1458
error_t ret_errno = 0;
1459
if(seteuid(0) == -1){
1461
perror_plus("seteuid");
1467
/* Set effective and real user ID to 0. Return errno. */
1468
__attribute__((warn_unused_result))
1469
error_t raise_privileges_permanently(void){
1470
error_t old_errno = errno;
1471
error_t ret_errno = raise_privileges();
1476
if(setuid(0) == -1){
1478
perror_plus("seteuid");
1484
/* Set effective user ID to unprivileged saved user ID */
1485
__attribute__((warn_unused_result))
1486
error_t lower_privileges(void){
1487
error_t old_errno = errno;
1488
error_t ret_errno = 0;
1489
if(seteuid(uid) == -1){
1491
perror_plus("seteuid");
1497
/* Lower privileges permanently */
1498
__attribute__((warn_unused_result))
1499
error_t lower_privileges_permanently(void){
1500
error_t old_errno = errno;
1501
error_t ret_errno = 0;
1502
if(setuid(uid) == -1){
1504
perror_plus("setuid");
1510
__attribute__((nonnull))
1511
void run_network_hooks(const char *mode, const char *interface,
1513
struct dirent **direntries = NULL;
1514
if(hookdir_fd == -1){
1515
hookdir_fd = open(hookdir, O_RDONLY);
1516
if(hookdir_fd == -1){
1517
if(errno == ENOENT){
1519
fprintf_plus(stderr, "Network hook directory \"%s\" not"
1520
" found\n", hookdir);
1523
perror_plus("open");
1529
#if __GLIBC_PREREQ(2, 15)
1530
int numhooks = scandirat(hookdir_fd, ".", &direntries,
1531
runnable_hook, alphasort);
1532
#else /* not __GLIBC_PREREQ(2, 15) */
1533
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1535
#endif /* not __GLIBC_PREREQ(2, 15) */
1536
#else /* not __GLIBC__ */
1537
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1539
#endif /* not __GLIBC__ */
1541
perror_plus("scandir");
1544
struct dirent *direntry;
1546
int devnull = open("/dev/null", O_RDONLY);
1547
for(int i = 0; i < numhooks; i++){
1548
direntry = direntries[i];
1550
fprintf_plus(stderr, "Running network hook \"%s\"\n",
1553
pid_t hook_pid = fork();
1556
/* Raise privileges */
1557
if(raise_privileges_permanently() != 0){
1558
perror_plus("Failed to raise privileges");
1565
perror_plus("setgid");
1568
/* Reset supplementary groups */
1570
ret = setgroups(0, NULL);
1572
perror_plus("setgroups");
1575
ret = dup2(devnull, STDIN_FILENO);
1577
perror_plus("dup2(devnull, STDIN_FILENO)");
1580
ret = close(devnull);
1582
perror_plus("close");
1585
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
1587
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
1590
ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);
1592
perror_plus("setenv");
1595
ret = setenv("DEVICE", interface, 1);
1597
perror_plus("setenv");
1600
ret = setenv("VERBOSITY", debug ? "1" : "0", 1);
1602
perror_plus("setenv");
1605
ret = setenv("MODE", mode, 1);
1607
perror_plus("setenv");
1611
ret = asprintf(&delaystring, "%f", (double)delay);
1613
perror_plus("asprintf");
1616
ret = setenv("DELAY", delaystring, 1);
1619
perror_plus("setenv");
1623
if(connect_to != NULL){
1624
ret = setenv("CONNECT", connect_to, 1);
1626
perror_plus("setenv");
1630
int hook_fd = openat(hookdir_fd, direntry->d_name, O_RDONLY);
1632
perror_plus("openat");
1633
_exit(EXIT_FAILURE);
1635
if((int)TEMP_FAILURE_RETRY(close(hookdir_fd)) == -1){
1636
perror_plus("close");
1637
_exit(EXIT_FAILURE);
1639
if(fexecve(hook_fd, (char *const []){ direntry->d_name, NULL },
1641
perror_plus("fexecve");
1642
_exit(EXIT_FAILURE);
1646
if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){
1647
perror_plus("waitpid");
1650
if(WIFEXITED(status)){
1651
if(WEXITSTATUS(status) != 0){
1652
fprintf_plus(stderr, "Warning: network hook \"%s\" exited"
1653
" with status %d\n", direntry->d_name,
1654
WEXITSTATUS(status));
1657
} else if(WIFSIGNALED(status)){
1658
fprintf_plus(stderr, "Warning: network hook \"%s\" died by"
1659
" signal %d\n", direntry->d_name,
1663
fprintf_plus(stderr, "Warning: network hook \"%s\""
1664
" crashed\n", direntry->d_name);
1669
fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",
1674
if((int)TEMP_FAILURE_RETRY(close(hookdir_fd)) == -1){
1675
perror_plus("close");
1682
__attribute__((nonnull, warn_unused_result))
1683
error_t bring_up_interface(const char *const interface,
1685
error_t old_errno = errno;
1687
struct ifreq network;
1688
unsigned int if_index = if_nametoindex(interface);
1690
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1700
if(not interface_is_up(interface)){
1701
error_t ret_errno = 0, ioctl_errno = 0;
1702
if(not get_flags(interface, &network)){
1704
fprintf_plus(stderr, "Failed to get flags for interface "
1705
"\"%s\"\n", interface);
1709
network.ifr_flags |= IFF_UP; /* set flag */
1711
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1714
perror_plus("socket");
1720
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1722
perror_plus("close");
1729
fprintf_plus(stderr, "Bringing up interface \"%s\"\n",
1733
/* Raise privileges */
1734
ret_errno = raise_privileges();
1736
perror_plus("Failed to raise privileges");
1741
bool restore_loglevel = false;
1743
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1744
messages about the network interface to mess up the prompt */
1745
ret_linux = klogctl(8, NULL, 5);
1746
if(ret_linux == -1){
1747
perror_plus("klogctl");
1749
restore_loglevel = true;
1752
#endif /* __linux__ */
1753
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1754
ioctl_errno = errno;
1756
if(restore_loglevel){
1757
ret_linux = klogctl(7, NULL, 0);
1758
if(ret_linux == -1){
1759
perror_plus("klogctl");
1762
#endif /* __linux__ */
1764
/* If raise_privileges() succeeded above */
1766
/* Lower privileges */
1767
ret_errno = lower_privileges();
1770
perror_plus("Failed to lower privileges");
1774
/* Close the socket */
1775
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1777
perror_plus("close");
1780
if(ret_setflags == -1){
1781
errno = ioctl_errno;
1782
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1787
fprintf_plus(stderr, "Interface \"%s\" is already up; good\n",
1791
/* Sleep checking until interface is running.
1792
Check every 0.25s, up to total time of delay */
1793
for(int i=0; i < delay * 4; i++){
1794
if(interface_is_running(interface)){
1797
struct timespec sleeptime = { .tv_nsec = 250000000 };
1798
ret = nanosleep(&sleeptime, NULL);
1799
if(ret == -1 and errno != EINTR){
1800
perror_plus("nanosleep");
1808
__attribute__((nonnull, warn_unused_result))
1809
error_t take_down_interface(const char *const interface){
1810
error_t old_errno = errno;
1811
struct ifreq network;
1812
unsigned int if_index = if_nametoindex(interface);
1814
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1818
if(interface_is_up(interface)){
1819
error_t ret_errno = 0, ioctl_errno = 0;
1820
if(not get_flags(interface, &network) and debug){
1822
fprintf_plus(stderr, "Failed to get flags for interface "
1823
"\"%s\"\n", interface);
1827
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1829
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1832
perror_plus("socket");
1838
fprintf_plus(stderr, "Taking down interface \"%s\"\n",
1842
/* Raise privileges */
1843
ret_errno = raise_privileges();
1845
perror_plus("Failed to raise privileges");
1848
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1849
ioctl_errno = errno;
1851
/* If raise_privileges() succeeded above */
1853
/* Lower privileges */
1854
ret_errno = lower_privileges();
1857
perror_plus("Failed to lower privileges");
1861
/* Close the socket */
1862
int ret = (int)TEMP_FAILURE_RETRY(close(sd));
1864
perror_plus("close");
1867
if(ret_setflags == -1){
1868
errno = ioctl_errno;
1869
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
1874
fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",
820
1882
int main(int argc, char *argv[]){
821
AvahiSServiceBrowser *sb = NULL;
826
int exitcode = EXIT_SUCCESS;
827
const char *interface = "eth0";
828
struct ifreq network;
832
char *connect_to = NULL;
833
char tempdir[] = "/tmp/mandosXXXXXX";
834
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
835
const char *seckey = PATHDIR "/" SECKEY;
836
const char *pubkey = PATHDIR "/" PUBKEY;
838
mandos_context mc = { .simple_poll = NULL, .server = NULL,
839
.dh_bits = 1024, .priority = "SECURE256"
840
":!CTYPE-X.509:+CTYPE-OPENPGP" };
841
bool gnutls_initalized = false;
842
bool gpgme_initalized = false;
845
struct argp_option options[] = {
846
{ .name = "debug", .key = 128,
847
.doc = "Debug mode", .group = 3 },
848
{ .name = "connect", .key = 'c',
849
.arg = "ADDRESS:PORT",
850
.doc = "Connect directly to a specific Mandos server",
852
{ .name = "interface", .key = 'i',
854
.doc = "Interface that will be used to search for Mandos"
857
{ .name = "seckey", .key = 's',
859
.doc = "OpenPGP secret key file base name",
861
{ .name = "pubkey", .key = 'p',
863
.doc = "OpenPGP public key file base name",
865
{ .name = "dh-bits", .key = 129,
867
.doc = "Bit length of the prime number used in the"
868
" Diffie-Hellman key exchange",
870
{ .name = "priority", .key = 130,
872
.doc = "GnuTLS priority string for the TLS handshake",
877
error_t parse_opt(int key, char *arg,
878
struct argp_state *state) {
880
case 128: /* --debug */
883
case 'c': /* --connect */
886
case 'i': /* --interface */
889
case 's': /* --seckey */
892
case 'p': /* --pubkey */
895
case 129: /* --dh-bits */
896
ret = sscanf(arg, "%" SCNdMAX "%n", &tmpmax, &numchars);
897
if(ret < 1 or tmpmax != (typeof(mc.dh_bits))tmpmax
898
or arg[numchars] != '\0'){
899
fprintf(stderr, "Bad number of DH bits\n");
902
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
904
case 130: /* --priority */
912
return ARGP_ERR_UNKNOWN;
917
struct argp argp = { .options = options, .parser = parse_opt,
919
.doc = "Mandos client -- Get and decrypt"
920
" passwords from a Mandos server" };
921
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
922
if(ret == ARGP_ERR_UNKNOWN){
923
fprintf(stderr, "Unknown error while parsing arguments\n");
924
exitcode = EXIT_FAILURE;
929
/* If the interface is down, bring it up */
931
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
934
exitcode = EXIT_FAILURE;
937
strcpy(network.ifr_name, interface);
938
ret = ioctl(sd, SIOCGIFFLAGS, &network);
940
perror("ioctl SIOCGIFFLAGS");
941
exitcode = EXIT_FAILURE;
944
if((network.ifr_flags & IFF_UP) == 0){
945
network.ifr_flags |= IFF_UP;
946
ret = ioctl(sd, SIOCSIFFLAGS, &network);
948
perror("ioctl SIOCSIFFLAGS");
949
exitcode = EXIT_FAILURE;
953
ret = (int)TEMP_FAILURE_RETRY(close(sd));
972
ret = init_gnutls_global(&mc, pubkey, seckey);
974
fprintf(stderr, "init_gnutls_global failed\n");
975
exitcode = EXIT_FAILURE;
978
gnutls_initalized = true;
981
if(mkdtemp(tempdir) == NULL){
987
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
988
fprintf(stderr, "gpgme_initalized failed\n");
989
exitcode = EXIT_FAILURE;
992
gpgme_initalized = true;
995
if_index = (AvahiIfIndex) if_nametoindex(interface);
997
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1001
if(connect_to != NULL){
1002
/* Connect directly, do not use Zeroconf */
1003
/* (Mainly meant for debugging) */
1004
char *address = strrchr(connect_to, ':');
1005
if(address == NULL){
1006
fprintf(stderr, "No colon in address\n");
1007
exitcode = EXIT_FAILURE;
1011
ret = sscanf(address+1, "%" SCNdMAX "%n", &tmpmax, &numchars);
1012
if(ret < 1 or tmpmax != (uint16_t)tmpmax
1013
or address[numchars+1] != '\0'){
1014
fprintf(stderr, "Bad port number\n");
1015
exitcode = EXIT_FAILURE;
1018
port = (uint16_t)tmpmax;
1020
address = connect_to;
1021
ret = start_mandos_communication(address, port, if_index, &mc);
1023
exitcode = EXIT_FAILURE;
1025
exitcode = EXIT_SUCCESS;
1031
avahi_set_log_function(empty_log);
1034
/* Initialize the pseudo-RNG for Avahi */
1035
srand((unsigned int) time(NULL));
1037
/* Allocate main Avahi loop object */
1038
mc.simple_poll = avahi_simple_poll_new();
1039
if(mc.simple_poll == NULL) {
1040
fprintf(stderr, "Avahi: Failed to create simple poll"
1042
exitcode = EXIT_FAILURE;
1047
AvahiServerConfig config;
1048
/* Do not publish any local Zeroconf records */
1049
avahi_server_config_init(&config);
1050
config.publish_hinfo = 0;
1051
config.publish_addresses = 0;
1052
config.publish_workstation = 0;
1053
config.publish_domain = 0;
1055
/* Allocate a new server */
1056
mc.server = avahi_server_new(avahi_simple_poll_get
1057
(mc.simple_poll), &config, NULL,
1060
/* Free the Avahi configuration data */
1061
avahi_server_config_free(&config);
1064
/* Check if creating the Avahi server object succeeded */
1065
if(mc.server == NULL) {
1066
fprintf(stderr, "Failed to create Avahi server: %s\n",
1067
avahi_strerror(error));
1068
exitcode = EXIT_FAILURE;
1072
/* Create the Avahi service browser */
1073
sb = avahi_s_service_browser_new(mc.server, if_index,
1075
"_mandos._tcp", NULL, 0,
1076
browse_callback, &mc);
1078
fprintf(stderr, "Failed to create service browser: %s\n",
1079
avahi_strerror(avahi_server_errno(mc.server)));
1080
exitcode = EXIT_FAILURE;
1084
/* Run the main loop */
1883
mandos_context mc = { .server = NULL, .dh_bits = 1024,
1884
.priority = "SECURE256:!CTYPE-X.509:"
1885
"+CTYPE-OPENPGP", .current_server = NULL,
1886
.interfaces = NULL, .interfaces_size = 0 };
1887
AvahiSServiceBrowser *sb = NULL;
1892
int exitcode = EXIT_SUCCESS;
1893
char *interfaces_to_take_down = NULL;
1894
size_t interfaces_to_take_down_size = 0;
1895
char run_tempdir[] = "/run/tmp/mandosXXXXXX";
1896
char old_tempdir[] = "/tmp/mandosXXXXXX";
1897
char *tempdir = NULL;
1898
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
1899
const char *seckey = PATHDIR "/" SECKEY;
1900
const char *pubkey = PATHDIR "/" PUBKEY;
1901
char *interfaces_hooks = NULL;
1903
bool gnutls_initialized = false;
1904
bool gpgme_initialized = false;
1906
double retry_interval = 10; /* 10s between trying a server and
1907
retrying the same server again */
1909
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
1910
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
1915
/* Lower any group privileges we might have, just to be safe */
1919
perror_plus("setgid");
1922
/* Lower user privileges (temporarily) */
1926
perror_plus("seteuid");
1934
struct argp_option options[] = {
1935
{ .name = "debug", .key = 128,
1936
.doc = "Debug mode", .group = 3 },
1937
{ .name = "connect", .key = 'c',
1938
.arg = "ADDRESS:PORT",
1939
.doc = "Connect directly to a specific Mandos server",
1941
{ .name = "interface", .key = 'i',
1943
.doc = "Network interface that will be used to search for"
1946
{ .name = "seckey", .key = 's',
1948
.doc = "OpenPGP secret key file base name",
1950
{ .name = "pubkey", .key = 'p',
1952
.doc = "OpenPGP public key file base name",
1954
{ .name = "dh-bits", .key = 129,
1956
.doc = "Bit length of the prime number used in the"
1957
" Diffie-Hellman key exchange",
1959
{ .name = "priority", .key = 130,
1961
.doc = "GnuTLS priority string for the TLS handshake",
1963
{ .name = "delay", .key = 131,
1965
.doc = "Maximum delay to wait for interface startup",
1967
{ .name = "retry", .key = 132,
1969
.doc = "Retry interval used when denied by the Mandos server",
1971
{ .name = "network-hook-dir", .key = 133,
1973
.doc = "Directory where network hooks are located",
1976
* These reproduce what we would get without ARGP_NO_HELP
1978
{ .name = "help", .key = '?',
1979
.doc = "Give this help list", .group = -1 },
1980
{ .name = "usage", .key = -3,
1981
.doc = "Give a short usage message", .group = -1 },
1982
{ .name = "version", .key = 'V',
1983
.doc = "Print program version", .group = -1 },
1987
error_t parse_opt(int key, char *arg,
1988
struct argp_state *state){
1991
case 128: /* --debug */
1994
case 'c': /* --connect */
1997
case 'i': /* --interface */
1998
ret_errno = argz_add_sep(&mc.interfaces, &mc.interfaces_size,
2001
argp_error(state, "%s", strerror(ret_errno));
2004
case 's': /* --seckey */
2007
case 'p': /* --pubkey */
2010
case 129: /* --dh-bits */
2012
tmpmax = strtoimax(arg, &tmp, 10);
2013
if(errno != 0 or tmp == arg or *tmp != '\0'
2014
or tmpmax != (typeof(mc.dh_bits))tmpmax){
2015
argp_error(state, "Bad number of DH bits");
2017
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
2019
case 130: /* --priority */
2022
case 131: /* --delay */
2024
delay = strtof(arg, &tmp);
2025
if(errno != 0 or tmp == arg or *tmp != '\0'){
2026
argp_error(state, "Bad delay");
2028
case 132: /* --retry */
2030
retry_interval = strtod(arg, &tmp);
2031
if(errno != 0 or tmp == arg or *tmp != '\0'
2032
or (retry_interval * 1000) > INT_MAX
2033
or retry_interval < 0){
2034
argp_error(state, "Bad retry interval");
2037
case 133: /* --network-hook-dir */
2041
* These reproduce what we would get without ARGP_NO_HELP
2043
case '?': /* --help */
2044
argp_state_help(state, state->out_stream,
2045
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
2046
& ~(unsigned int)ARGP_HELP_EXIT_OK);
2047
case -3: /* --usage */
2048
argp_state_help(state, state->out_stream,
2049
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
2050
case 'V': /* --version */
2051
fprintf_plus(state->out_stream, "%s\n", argp_program_version);
2052
exit(argp_err_exit_status);
2055
return ARGP_ERR_UNKNOWN;
2060
struct argp argp = { .options = options, .parser = parse_opt,
2062
.doc = "Mandos client -- Get and decrypt"
2063
" passwords from a Mandos server" };
2064
ret = argp_parse(&argp, argc, argv,
2065
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
2072
perror_plus("argp_parse");
2073
exitcode = EX_OSERR;
2076
exitcode = EX_USAGE;
2082
/* Work around Debian bug #633582:
2083
<http://bugs.debian.org/633582> */
2085
/* Re-raise privileges */
2086
ret_errno = raise_privileges();
2089
perror_plus("Failed to raise privileges");
2093
if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){
2094
int seckey_fd = open(seckey, O_RDONLY);
2095
if(seckey_fd == -1){
2096
perror_plus("open");
2098
ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));
2100
perror_plus("fstat");
2102
if(S_ISREG(st.st_mode)
2103
and st.st_uid == 0 and st.st_gid == 0){
2104
ret = fchown(seckey_fd, uid, gid);
2106
perror_plus("fchown");
2110
TEMP_FAILURE_RETRY(close(seckey_fd));
2114
if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){
2115
int pubkey_fd = open(pubkey, O_RDONLY);
2116
if(pubkey_fd == -1){
2117
perror_plus("open");
2119
ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));
2121
perror_plus("fstat");
2123
if(S_ISREG(st.st_mode)
2124
and st.st_uid == 0 and st.st_gid == 0){
2125
ret = fchown(pubkey_fd, uid, gid);
2127
perror_plus("fchown");
2131
TEMP_FAILURE_RETRY(close(pubkey_fd));
2135
/* Lower privileges */
2136
ret_errno = lower_privileges();
2139
perror_plus("Failed to lower privileges");
2144
/* Remove invalid interface names (except "none") */
2146
char *interface = NULL;
2147
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2149
if(strcmp(interface, "none") != 0
2150
and if_nametoindex(interface) == 0){
2151
if(interface[0] != '\0'){
2152
fprintf_plus(stderr, "Not using nonexisting interface"
2153
" \"%s\"\n", interface);
2155
argz_delete(&mc.interfaces, &mc.interfaces_size, interface);
2161
/* Run network hooks */
2163
if(mc.interfaces != NULL){
2164
interfaces_hooks = malloc(mc.interfaces_size);
2165
if(interfaces_hooks == NULL){
2166
perror_plus("malloc");
2169
memcpy(interfaces_hooks, mc.interfaces, mc.interfaces_size);
2170
argz_stringify(interfaces_hooks, mc.interfaces_size, (int)',');
2172
run_network_hooks("start", interfaces_hooks != NULL ?
2173
interfaces_hooks : "", delay);
2177
avahi_set_log_function(empty_log);
2180
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
2181
from the signal handler */
2182
/* Initialize the pseudo-RNG for Avahi */
2183
srand((unsigned int) time(NULL));
2184
simple_poll = avahi_simple_poll_new();
2185
if(simple_poll == NULL){
2186
fprintf_plus(stderr,
2187
"Avahi: Failed to create simple poll object.\n");
2188
exitcode = EX_UNAVAILABLE;
2192
sigemptyset(&sigterm_action.sa_mask);
2193
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
2195
perror_plus("sigaddset");
2196
exitcode = EX_OSERR;
2199
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
2201
perror_plus("sigaddset");
2202
exitcode = EX_OSERR;
2205
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
2207
perror_plus("sigaddset");
2208
exitcode = EX_OSERR;
2211
/* Need to check if the handler is SIG_IGN before handling:
2212
| [[info:libc:Initial Signal Actions]] |
2213
| [[info:libc:Basic Signal Handling]] |
2215
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
2217
perror_plus("sigaction");
2220
if(old_sigterm_action.sa_handler != SIG_IGN){
2221
ret = sigaction(SIGINT, &sigterm_action, NULL);
2223
perror_plus("sigaction");
2224
exitcode = EX_OSERR;
2228
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
2230
perror_plus("sigaction");
2233
if(old_sigterm_action.sa_handler != SIG_IGN){
2234
ret = sigaction(SIGHUP, &sigterm_action, NULL);
2236
perror_plus("sigaction");
2237
exitcode = EX_OSERR;
2241
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
2243
perror_plus("sigaction");
2246
if(old_sigterm_action.sa_handler != SIG_IGN){
2247
ret = sigaction(SIGTERM, &sigterm_action, NULL);
2249
perror_plus("sigaction");
2250
exitcode = EX_OSERR;
2255
/* If no interfaces were specified, make a list */
2256
if(mc.interfaces == NULL){
2257
struct dirent **direntries = NULL;
2258
/* Look for any good interfaces */
2259
ret = scandir(sys_class_net, &direntries, good_interface,
2262
/* Add all found interfaces to interfaces list */
2263
for(int i = 0; i < ret; ++i){
2264
ret_errno = argz_add(&mc.interfaces, &mc.interfaces_size,
2265
direntries[i]->d_name);
2268
perror_plus("argz_add");
2272
fprintf_plus(stderr, "Will use interface \"%s\"\n",
2273
direntries[i]->d_name);
2281
fprintf_plus(stderr, "Could not find a network interface\n");
2282
exitcode = EXIT_FAILURE;
2287
/* Bring up interfaces which are down, and remove any "none"s */
2289
char *interface = NULL;
2290
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2292
/* If interface name is "none", stop bringing up interfaces.
2293
Also remove all instances of "none" from the list */
2294
if(strcmp(interface, "none") == 0){
2295
argz_delete(&mc.interfaces, &mc.interfaces_size,
2298
while((interface = argz_next(mc.interfaces,
2299
mc.interfaces_size, interface))){
2300
if(strcmp(interface, "none") == 0){
2301
argz_delete(&mc.interfaces, &mc.interfaces_size,
2308
bool interface_was_up = interface_is_up(interface);
2309
errno = bring_up_interface(interface, delay);
2310
if(not interface_was_up){
2312
perror_plus("Failed to bring up interface");
2314
errno = argz_add(&interfaces_to_take_down,
2315
&interfaces_to_take_down_size,
2318
perror_plus("argz_add");
2323
if(debug and (interfaces_to_take_down == NULL)){
2324
fprintf_plus(stderr, "No interfaces were brought up\n");
2328
/* If we only got one interface, explicitly use only that one */
2329
if(argz_count(mc.interfaces, mc.interfaces_size) == 1){
1087
fprintf(stderr, "Starting Avahi loop search\n");
1090
avahi_simple_poll_loop(mc.simple_poll);
2331
fprintf_plus(stderr, "Using only interface \"%s\"\n",
2334
if_index = (AvahiIfIndex)if_nametoindex(mc.interfaces);
2341
ret = init_gnutls_global(pubkey, seckey, &mc);
2343
fprintf_plus(stderr, "init_gnutls_global failed\n");
2344
exitcode = EX_UNAVAILABLE;
2347
gnutls_initialized = true;
2354
/* Try /run/tmp before /tmp */
2355
tempdir = mkdtemp(run_tempdir);
2356
if(tempdir == NULL and errno == ENOENT){
2358
fprintf_plus(stderr, "Tempdir %s did not work, trying %s\n",
2359
run_tempdir, old_tempdir);
2361
tempdir = mkdtemp(old_tempdir);
2363
if(tempdir == NULL){
2364
perror_plus("mkdtemp");
2372
if(not init_gpgme(pubkey, seckey, tempdir, &mc)){
2373
fprintf_plus(stderr, "init_gpgme failed\n");
2374
exitcode = EX_UNAVAILABLE;
2377
gpgme_initialized = true;
2384
if(connect_to != NULL){
2385
/* Connect directly, do not use Zeroconf */
2386
/* (Mainly meant for debugging) */
2387
char *address = strrchr(connect_to, ':');
2389
if(address == NULL){
2390
fprintf_plus(stderr, "No colon in address\n");
2391
exitcode = EX_USAGE;
2401
tmpmax = strtoimax(address+1, &tmp, 10);
2402
if(errno != 0 or tmp == address+1 or *tmp != '\0'
2403
or tmpmax != (in_port_t)tmpmax){
2404
fprintf_plus(stderr, "Bad port number\n");
2405
exitcode = EX_USAGE;
2413
port = (in_port_t)tmpmax;
2415
/* Colon in address indicates IPv6 */
2417
if(strchr(connect_to, ':') != NULL){
2419
/* Accept [] around IPv6 address - see RFC 5952 */
2420
if(connect_to[0] == '[' and address[-1] == ']')
2428
address = connect_to;
2434
while(not quit_now){
2435
ret = start_mandos_communication(address, port, if_index, af,
2437
if(quit_now or ret == 0){
2441
fprintf_plus(stderr, "Retrying in %d seconds\n",
2442
(int)retry_interval);
2444
sleep((unsigned int)retry_interval);
2448
exitcode = EXIT_SUCCESS;
2459
AvahiServerConfig config;
2460
/* Do not publish any local Zeroconf records */
2461
avahi_server_config_init(&config);
2462
config.publish_hinfo = 0;
2463
config.publish_addresses = 0;
2464
config.publish_workstation = 0;
2465
config.publish_domain = 0;
2467
/* Allocate a new server */
2468
mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),
2469
&config, NULL, NULL, &ret_errno);
2471
/* Free the Avahi configuration data */
2472
avahi_server_config_free(&config);
2475
/* Check if creating the Avahi server object succeeded */
2476
if(mc.server == NULL){
2477
fprintf_plus(stderr, "Failed to create Avahi server: %s\n",
2478
avahi_strerror(ret_errno));
2479
exitcode = EX_UNAVAILABLE;
2487
/* Create the Avahi service browser */
2488
sb = avahi_s_service_browser_new(mc.server, if_index,
2489
AVAHI_PROTO_UNSPEC, "_mandos._tcp",
2490
NULL, 0, browse_callback,
2493
fprintf_plus(stderr, "Failed to create service browser: %s\n",
2494
avahi_strerror(avahi_server_errno(mc.server)));
2495
exitcode = EX_UNAVAILABLE;
2503
/* Run the main loop */
2506
fprintf_plus(stderr, "Starting Avahi loop search\n");
2509
ret = avahi_loop_with_timeout(simple_poll,
2510
(int)(retry_interval * 1000), &mc);
2512
fprintf_plus(stderr, "avahi_loop_with_timeout exited %s\n",
2513
(ret == 0) ? "successfully" : "with error");
1095
fprintf(stderr, "%s exiting\n", argv[0]);
1098
/* Cleanup things */
1100
avahi_s_service_browser_free(sb);
1102
if(mc.server != NULL)
1103
avahi_server_free(mc.server);
1105
if(mc.simple_poll != NULL)
1106
avahi_simple_poll_free(mc.simple_poll);
1108
if(gnutls_initalized){
1109
gnutls_certificate_free_credentials(mc.cred);
1110
gnutls_global_deinit();
1111
gnutls_dh_params_deinit(mc.dh_params);
1114
if(gpgme_initalized){
1115
gpgme_release(mc.ctx);
1118
/* Removes the temp directory used by GPGME */
1119
if(tempdir[0] != '\0'){
1121
struct dirent *direntry;
1122
d = opendir(tempdir);
1124
if(errno != ENOENT){
1129
direntry = readdir(d);
1130
if(direntry == NULL){
1133
if(direntry->d_type == DT_REG){
1134
char *fullname = NULL;
1135
ret = asprintf(&fullname, "%s/%s", tempdir,
1141
ret = unlink(fullname);
1143
fprintf(stderr, "unlink(\"%s\"): %s",
1144
fullname, strerror(errno));
1151
ret = rmdir(tempdir);
1152
if(ret == -1 and errno != ENOENT){
2519
fprintf_plus(stderr, "%s exiting\n", argv[0]);
2522
/* Cleanup things */
2523
free(mc.interfaces);
2526
avahi_s_service_browser_free(sb);
2528
if(mc.server != NULL)
2529
avahi_server_free(mc.server);
2531
if(simple_poll != NULL)
2532
avahi_simple_poll_free(simple_poll);
2534
if(gnutls_initialized){
2535
gnutls_certificate_free_credentials(mc.cred);
2536
gnutls_global_deinit();
2537
gnutls_dh_params_deinit(mc.dh_params);
2540
if(gpgme_initialized){
2541
gpgme_release(mc.ctx);
2544
/* Cleans up the circular linked list of Mandos servers the client
2546
if(mc.current_server != NULL){
2547
mc.current_server->prev->next = NULL;
2548
while(mc.current_server != NULL){
2549
server *next = mc.current_server->next;
2550
free(mc.current_server);
2551
mc.current_server = next;
2555
/* Re-raise privileges */
2557
ret_errno = raise_privileges();
2559
perror_plus("Failed to raise privileges");
2562
/* Run network hooks */
2563
run_network_hooks("stop", interfaces_hooks != NULL ?
2564
interfaces_hooks : "", delay);
2566
/* Take down the network interfaces which were brought up */
2568
char *interface = NULL;
2569
while((interface=argz_next(interfaces_to_take_down,
2570
interfaces_to_take_down_size,
2572
ret_errno = take_down_interface(interface);
2575
perror_plus("Failed to take down interface");
2578
if(debug and (interfaces_to_take_down == NULL)){
2579
fprintf_plus(stderr, "No interfaces needed to be taken"
2585
ret_errno = lower_privileges_permanently();
2587
perror_plus("Failed to lower privileges permanently");
2591
free(interfaces_to_take_down);
2592
free(interfaces_hooks);
2594
/* Removes the GPGME temp directory and all files inside */
2595
if(tempdir != NULL){
2596
struct dirent **direntries = NULL;
2597
int tempdir_fd = (int)TEMP_FAILURE_RETRY(open(tempdir, O_RDONLY |
2599
if(tempdir_fd == -1){
2600
perror_plus("open");
2603
#if __GLIBC_PREREQ(2, 15)
2604
int numentries = scandirat(tempdir_fd, ".", &direntries,
2605
notdotentries, alphasort);
2606
#else /* not __GLIBC_PREREQ(2, 15) */
2607
int numentries = scandir(tempdir, &direntries, notdotentries,
2609
#endif /* not __GLIBC_PREREQ(2, 15) */
2610
#else /* not __GLIBC__ */
2611
int numentries = scandir(tempdir, &direntries, notdotentries,
2613
#endif /* not __GLIBC__ */
2614
if(numentries >= 0){
2615
for(int i = 0; i < numentries; i++){
2616
ret = unlinkat(tempdir_fd, direntries[i]->d_name, 0);
2618
fprintf_plus(stderr, "unlinkat(open(\"%s\", O_RDONLY),"
2619
" \"%s\", 0): %s\n", tempdir,
2620
direntries[i]->d_name, strerror(errno));
2624
/* need to clean even if 0 because man page doesn't specify */
2626
if(numentries == -1){
2627
perror_plus("scandir");
2629
ret = rmdir(tempdir);
2630
if(ret == -1 and errno != ENOENT){
2631
perror_plus("rmdir");
2634
TEMP_FAILURE_RETRY(close(tempdir_fd));
2639
sigemptyset(&old_sigterm_action.sa_mask);
2640
old_sigterm_action.sa_handler = SIG_DFL;
2641
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
2642
&old_sigterm_action,
2645
perror_plus("sigaction");
2648
ret = raise(signal_received);
2649
} while(ret != 0 and errno == EINTR);
2651
perror_plus("raise");
2654
TEMP_FAILURE_RETRY(pause());