621
497
__attribute__((unused)) const char *txt){}
623
499
/* Called when a Mandos server is found */
624
static int start_mandos_communication(const char *ip, in_port_t port,
500
static int start_mandos_communication(const char *ip, uint16_t port,
625
501
AvahiIfIndex if_index,
626
int af, mandos_context *mc){
627
int ret, tcp_sd = -1;
630
struct sockaddr_in in;
631
struct sockaddr_in6 in6;
505
union { struct sockaddr in; struct sockaddr_in6 in6; } to;
633
506
char *buffer = NULL;
634
char *decrypted_buffer = NULL;
507
char *decrypted_buffer;
635
508
size_t buffer_length = 0;
636
509
size_t buffer_capacity = 0;
510
ssize_t decrypted_buffer_size;
513
char interface[IF_NAMESIZE];
639
514
gnutls_session_t session;
640
int pf; /* Protocol family */
657
fprintf_plus(stderr, "Bad address family: %d\n", af);
662
/* If the interface is specified and we have a list of interfaces */
663
if(if_index != AVAHI_IF_UNSPEC and mc->interfaces != NULL){
664
/* Check if the interface is one of the interfaces we are using */
667
char *interface = NULL;
668
while((interface=argz_next(mc->interfaces, mc->interfaces_size,
670
if(if_nametoindex(interface) == (unsigned int)if_index){
677
/* This interface does not match any in the list, so we don't
678
connect to the server */
680
char interface[IF_NAMESIZE];
681
if(if_indextoname((unsigned int)if_index, interface) == NULL){
682
perror_plus("if_indextoname");
684
fprintf_plus(stderr, "Skipping server on non-used interface"
686
if_indextoname((unsigned int)if_index,
516
ret = init_gnutls_session (mc, &session);
522
fprintf(stderr, "Setting up a tcp connection to %s, port %" PRIu16
526
tcp_sd = socket(PF_INET6, SOCK_STREAM, 0);
533
if(if_indextoname((unsigned int)if_index, interface) == NULL){
534
perror("if_indextoname");
694
ret = init_gnutls_session(&session, mc);
700
fprintf_plus(stderr, "Setting up a TCP connection to %s, port %"
701
PRIuMAX "\n", ip, (uintmax_t)port);
704
tcp_sd = socket(pf, SOCK_STREAM, 0);
707
perror_plus("socket");
537
fprintf(stderr, "Binding to interface %s\n", interface);
717
540
memset(&to, 0, sizeof(to));
719
to.in6.sin6_family = (sa_family_t)af;
720
ret = inet_pton(af, ip, &to.in6.sin6_addr);
722
to.in.sin_family = (sa_family_t)af;
723
ret = inet_pton(af, ip, &to.in.sin_addr);
727
perror_plus("inet_pton");
541
to.in6.sin6_family = AF_INET6;
542
/* It would be nice to have a way to detect if we were passed an
543
IPv4 address here. Now we assume an IPv6 address. */
544
ret = inet_pton(AF_INET6, ip, &to.in6.sin6_addr);
733
fprintf_plus(stderr, "Bad address: %s\n", ip);
738
to.in6.sin6_port = htons(port);
739
if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */
740
(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower and
742
if(if_index == AVAHI_IF_UNSPEC){
743
fprintf_plus(stderr, "An IPv6 link-local address is"
744
" incomplete without a network interface\n");
748
/* Set the network interface number as scope */
749
to.in6.sin6_scope_id = (uint32_t)if_index;
752
to.in.sin_port = htons(port); /* Spurious warnings from
754
-Wunreachable-code */
550
fprintf(stderr, "Bad address: %s\n", ip);
553
to.in6.sin6_port = htons(port); /* Spurious warning */
555
to.in6.sin6_scope_id = (uint32_t)if_index;
763
if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){
764
char interface[IF_NAMESIZE];
765
if(if_indextoname((unsigned int)if_index, interface) == NULL){
766
perror_plus("if_indextoname");
768
fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIuMAX
769
"\n", ip, interface, (uintmax_t)port);
772
fprintf_plus(stderr, "Connection to: %s, port %" PRIuMAX "\n",
773
ip, (uintmax_t)port);
775
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
776
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
779
pcret = inet_ntop(af, &(to.in6.sin6_addr), addrstr,
782
pcret = inet_ntop(af, &(to.in.sin_addr), addrstr,
786
perror_plus("inet_ntop");
558
fprintf(stderr, "Connection to: %s, port %" PRIu16 "\n", ip,
560
char addrstr[INET6_ADDRSTRLEN] = "";
561
if(inet_ntop(to.in6.sin6_family, &(to.in6.sin6_addr), addrstr,
562
sizeof(addrstr)) == NULL){
788
565
if(strcmp(addrstr, ip) != 0){
789
fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);
566
fprintf(stderr, "Canonical address form: %s\n", addrstr);
800
ret = connect(tcp_sd, &to.in6, sizeof(to));
802
ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */
805
if ((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){
807
perror_plus("connect");
571
ret = connect(tcp_sd, &to.in, sizeof(to));
818
577
const char *out = mandos_protocol_version;
821
580
size_t out_size = strlen(out);
822
581
ret = (int)TEMP_FAILURE_RETRY(write(tcp_sd, out + written,
823
out_size - written));
826
perror_plus("write");
582
out_size - written));
830
588
written += (size_t)ret;
831
589
if(written < out_size){
834
if(out == mandos_protocol_version){
592
if (out == mandos_protocol_version){
849
fprintf_plus(stderr, "Establishing TLS session with %s\n", ip);
857
/* This casting via intptr_t is to eliminate warning about casting
858
an int to a pointer type. This is exactly how the GnuTLS Guile
859
function "set-session-transport-fd!" does it. */
860
gnutls_transport_set_ptr(session,
861
(gnutls_transport_ptr_t)(intptr_t)tcp_sd);
869
ret = gnutls_handshake(session);
602
fprintf(stderr, "Establishing TLS session with %s\n", ip);
605
gnutls_transport_set_ptr (session, (gnutls_transport_ptr_t) tcp_sd);
608
ret = gnutls_handshake (session);
874
609
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
876
if(ret != GNUTLS_E_SUCCESS){
611
if (ret != GNUTLS_E_SUCCESS){
878
fprintf_plus(stderr, "*** GnuTLS Handshake failed ***\n");
613
fprintf(stderr, "*** GnuTLS Handshake failed ***\n");
885
620
/* Read OpenPGP packet that contains the wanted password */
888
fprintf_plus(stderr, "Retrieving OpenPGP encrypted password from"
623
fprintf(stderr, "Retrieving pgp encrypted password from %s\n",
899
buffer_capacity = incbuffer(&buffer, buffer_length,
901
if(buffer_capacity == 0){
903
perror_plus("incbuffer");
628
buffer_capacity = adjustbuffer(&buffer, buffer_length,
630
if (buffer_capacity == 0){
631
perror("adjustbuffer");
913
636
sret = gnutls_record_recv(session, buffer+buffer_length,
920
643
case GNUTLS_E_INTERRUPTED:
921
644
case GNUTLS_E_AGAIN:
923
646
case GNUTLS_E_REHANDSHAKE:
925
ret = gnutls_handshake(session);
648
ret = gnutls_handshake (session);
931
649
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
933
fprintf_plus(stderr, "*** GnuTLS Re-handshake failed "
651
fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");
941
fprintf_plus(stderr, "Unknown error while reading data from"
942
" encrypted session with Mandos server\n");
943
gnutls_bye(session, GNUTLS_SHUT_RDWR);
658
fprintf(stderr, "Unknown error while reading data from"
659
" encrypted session with Mandos server\n");
661
gnutls_bye (session, GNUTLS_SHUT_RDWR);
1139
803
case AVAHI_BROWSER_ALL_FOR_NOW:
1140
804
case AVAHI_BROWSER_CACHE_EXHAUSTED:
1142
fprintf_plus(stderr, "No Mandos server found, still"
806
fprintf(stderr, "No Mandos server found, still searching...\n");
1149
/* Signal handler that stops main loop after SIGTERM */
1150
static void handle_sigterm(int sig){
1155
signal_received = sig;
1156
int old_errno = errno;
1157
/* set main loop to exit */
1158
if(simple_poll != NULL){
1159
avahi_simple_poll_quit(simple_poll);
1164
bool get_flags(const char *ifname, struct ifreq *ifr){
1168
int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1171
perror_plus("socket");
1175
strcpy(ifr->ifr_name, ifname);
1176
ret = ioctl(s, SIOCGIFFLAGS, ifr);
1180
perror_plus("ioctl SIOCGIFFLAGS");
1188
bool good_flags(const char *ifname, const struct ifreq *ifr){
1190
/* Reject the loopback device */
1191
if(ifr->ifr_flags & IFF_LOOPBACK){
1193
fprintf_plus(stderr, "Rejecting loopback interface \"%s\"\n",
1198
/* Accept point-to-point devices only if connect_to is specified */
1199
if(connect_to != NULL and (ifr->ifr_flags & IFF_POINTOPOINT)){
1201
fprintf_plus(stderr, "Accepting point-to-point interface"
1202
" \"%s\"\n", ifname);
1206
/* Otherwise, reject non-broadcast-capable devices */
1207
if(not (ifr->ifr_flags & IFF_BROADCAST)){
1209
fprintf_plus(stderr, "Rejecting non-broadcast interface"
1210
" \"%s\"\n", ifname);
1214
/* Reject non-ARP interfaces (including dummy interfaces) */
1215
if(ifr->ifr_flags & IFF_NOARP){
1217
fprintf_plus(stderr, "Rejecting non-ARP interface \"%s\"\n",
1223
/* Accept this device */
1225
fprintf_plus(stderr, "Interface \"%s\" is good\n", ifname);
1231
* This function determines if a directory entry in /sys/class/net
1232
* corresponds to an acceptable network device.
1233
* (This function is passed to scandir(3) as a filter function.)
1235
int good_interface(const struct dirent *if_entry){
1236
if(if_entry->d_name[0] == '.'){
1241
if(not get_flags(if_entry->d_name, &ifr)){
1243
fprintf_plus(stderr, "Failed to get flags for interface "
1244
"\"%s\"\n", if_entry->d_name);
1249
if(not good_flags(if_entry->d_name, &ifr)){
1256
* This function determines if a network interface is up.
1258
bool interface_is_up(const char *interface){
1260
if(not get_flags(interface, &ifr)){
1262
fprintf_plus(stderr, "Failed to get flags for interface "
1263
"\"%s\"\n", interface);
1268
return (bool)(ifr.ifr_flags & IFF_UP);
1272
* This function determines if a network interface is running
1274
bool interface_is_running(const char *interface){
1276
if(not get_flags(interface, &ifr)){
1278
fprintf_plus(stderr, "Failed to get flags for interface "
1279
"\"%s\"\n", interface);
1284
return (bool)(ifr.ifr_flags & IFF_RUNNING);
1287
int notdotentries(const struct dirent *direntry){
1288
/* Skip "." and ".." */
1289
if(direntry->d_name[0] == '.'
1290
and (direntry->d_name[1] == '\0'
1291
or (direntry->d_name[1] == '.'
1292
and direntry->d_name[2] == '\0'))){
1298
/* Is this directory entry a runnable program? */
1299
int runnable_hook(const struct dirent *direntry){
1304
if((direntry->d_name)[0] == '\0'){
1309
sret = strspn(direntry->d_name, "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
1310
"abcdefghijklmnopqrstuvwxyz"
1313
if((direntry->d_name)[sret] != '\0'){
1314
/* Contains non-allowed characters */
1316
fprintf_plus(stderr, "Ignoring hook \"%s\" with bad name\n",
1322
char *fullname = NULL;
1323
ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);
1325
perror_plus("asprintf");
1329
ret = stat(fullname, &st);
1332
perror_plus("Could not stat hook");
1336
if(not (S_ISREG(st.st_mode))){
1337
/* Not a regular file */
1339
fprintf_plus(stderr, "Ignoring hook \"%s\" - not a file\n",
1344
if(not (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))){
1345
/* Not executable */
1347
fprintf_plus(stderr, "Ignoring hook \"%s\" - not executable\n",
1353
fprintf_plus(stderr, "Hook \"%s\" is acceptable\n",
1359
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,
1360
mandos_context *mc){
1362
struct timespec now;
1363
struct timespec waited_time;
1364
intmax_t block_time;
1367
if(mc->current_server == NULL){
1369
fprintf_plus(stderr, "Wait until first server is found."
1372
ret = avahi_simple_poll_iterate(s, -1);
1375
fprintf_plus(stderr, "Check current_server if we should run"
1378
/* the current time */
1379
ret = clock_gettime(CLOCK_MONOTONIC, &now);
812
int main(int argc, char *argv[]){
813
AvahiSServiceBrowser *sb = NULL;
816
int exitcode = EXIT_SUCCESS;
817
const char *interface = "eth0";
818
struct ifreq network;
822
char *connect_to = NULL;
823
char tempdir[] = "/tmp/mandosXXXXXX";
824
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
825
const char *seckey = PATHDIR "/" SECKEY;
826
const char *pubkey = PATHDIR "/" PUBKEY;
828
mandos_context mc = { .simple_poll = NULL, .server = NULL,
829
.dh_bits = 1024, .priority = "SECURE256"
830
":!CTYPE-X.509:+CTYPE-OPENPGP" };
831
bool gnutls_initalized = false;
832
bool gpgme_initalized = false;
835
struct argp_option options[] = {
836
{ .name = "debug", .key = 128,
837
.doc = "Debug mode", .group = 3 },
838
{ .name = "connect", .key = 'c',
839
.arg = "ADDRESS:PORT",
840
.doc = "Connect directly to a specific Mandos server",
842
{ .name = "interface", .key = 'i',
844
.doc = "Interface that will be used to search for Mandos"
847
{ .name = "seckey", .key = 's',
849
.doc = "OpenPGP secret key file base name",
851
{ .name = "pubkey", .key = 'p',
853
.doc = "OpenPGP public key file base name",
855
{ .name = "dh-bits", .key = 129,
857
.doc = "Bit length of the prime number used in the"
858
" Diffie-Hellman key exchange",
860
{ .name = "priority", .key = 130,
862
.doc = "GnuTLS priority string for the TLS handshake",
867
error_t parse_opt (int key, char *arg,
868
struct argp_state *state) {
870
case 128: /* --debug */
873
case 'c': /* --connect */
876
case 'i': /* --interface */
879
case 's': /* --seckey */
882
case 'p': /* --pubkey */
885
case 129: /* --dh-bits */
886
ret = sscanf(arg, "%u", &mc.dh_bits);
888
fprintf(stderr, "Bad number of DH bits\n");
892
case 130: /* --priority */
900
return ARGP_ERR_UNKNOWN;
905
struct argp argp = { .options = options, .parser = parse_opt,
907
.doc = "Mandos client -- Get and decrypt"
908
" passwords from a Mandos server" };
909
ret = argp_parse (&argp, argc, argv, 0, 0, NULL);
910
if (ret == ARGP_ERR_UNKNOWN){
911
fprintf(stderr, "Unknown error while parsing arguments\n");
912
exitcode = EXIT_FAILURE;
917
/* If the interface is down, bring it up */
919
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
922
exitcode = EXIT_FAILURE;
925
strcpy(network.ifr_name, interface);
926
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1381
perror_plus("clock_gettime");
1384
/* Calculating in ms how long time between now and server
1385
who we visted longest time ago. Now - last seen. */
1386
waited_time.tv_sec = (now.tv_sec
1387
- mc->current_server->last_seen.tv_sec);
1388
waited_time.tv_nsec = (now.tv_nsec
1389
- mc->current_server->last_seen.tv_nsec);
1390
/* total time is 10s/10,000ms.
1391
Converting to s from ms by dividing by 1,000,
1392
and ns to ms by dividing by 1,000,000. */
1393
block_time = ((retry_interval
1394
- ((intmax_t)waited_time.tv_sec * 1000))
1395
- ((intmax_t)waited_time.tv_nsec / 1000000));
1398
fprintf_plus(stderr, "Blocking for %" PRIdMAX " ms\n",
1402
if(block_time <= 0){
1403
ret = start_mandos_communication(mc->current_server->ip,
1404
mc->current_server->port,
1405
mc->current_server->if_index,
1406
mc->current_server->af, mc);
1408
avahi_simple_poll_quit(s);
1411
ret = clock_gettime(CLOCK_MONOTONIC,
1412
&mc->current_server->last_seen);
928
perror("ioctl SIOCGIFFLAGS");
929
exitcode = EXIT_FAILURE;
932
if((network.ifr_flags & IFF_UP) == 0){
933
network.ifr_flags |= IFF_UP;
934
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1414
perror_plus("clock_gettime");
936
perror("ioctl SIOCSIFFLAGS");
937
exitcode = EXIT_FAILURE;
1417
mc->current_server = mc->current_server->next;
1418
block_time = 0; /* Call avahi to find new Mandos
1419
servers, but don't block */
1422
ret = avahi_simple_poll_iterate(s, (int)block_time);
1425
if (ret > 0 or errno != EINTR){
1426
return (ret != 1) ? ret : 0;
1432
/* Set effective uid to 0, return errno */
1433
error_t raise_privileges(void){
1434
error_t old_errno = errno;
1435
error_t ret_errno = 0;
1436
if(seteuid(0) == -1){
1438
perror_plus("seteuid");
1444
/* Set effective and real user ID to 0. Return errno. */
1445
error_t raise_privileges_permanently(void){
1446
error_t old_errno = errno;
1447
error_t ret_errno = raise_privileges();
1452
if(setuid(0) == -1){
1454
perror_plus("seteuid");
1460
/* Set effective user ID to unprivileged saved user ID */
1461
error_t lower_privileges(void){
1462
error_t old_errno = errno;
1463
error_t ret_errno = 0;
1464
if(seteuid(uid) == -1){
1466
perror_plus("seteuid");
1472
/* Lower privileges permanently */
1473
error_t lower_privileges_permanently(void){
1474
error_t old_errno = errno;
1475
error_t ret_errno = 0;
1476
if(setuid(uid) == -1){
1478
perror_plus("setuid");
1484
bool run_network_hooks(const char *mode, const char *interface,
1486
struct dirent **direntries;
1487
struct dirent *direntry;
1489
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1492
if(errno == ENOENT){
1494
fprintf_plus(stderr, "Network hook directory \"%s\" not"
1495
" found\n", hookdir);
1498
perror_plus("scandir");
1501
int devnull = open("/dev/null", O_RDONLY);
1502
for(int i = 0; i < numhooks; i++){
1503
direntry = direntries[i];
1504
char *fullname = NULL;
1505
ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);
941
ret = (int)TEMP_FAILURE_RETRY(close(sd));
960
ret = init_gnutls_global(&mc, pubkey, seckey);
962
fprintf(stderr, "init_gnutls_global failed\n");
963
exitcode = EXIT_FAILURE;
966
gnutls_initalized = true;
969
if(mkdtemp(tempdir) == NULL){
975
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
976
fprintf(stderr, "gpgme_initalized failed\n");
977
exitcode = EXIT_FAILURE;
980
gpgme_initalized = true;
983
if_index = (AvahiIfIndex) if_nametoindex(interface);
985
fprintf(stderr, "No such interface: \"%s\"\n", interface);
989
if(connect_to != NULL){
990
/* Connect directly, do not use Zeroconf */
991
/* (Mainly meant for debugging) */
992
char *address = strrchr(connect_to, ':');
994
fprintf(stderr, "No colon in address\n");
995
exitcode = EXIT_FAILURE;
999
ret = sscanf(address+1, "%" SCNu16, &port);
1001
fprintf(stderr, "Bad port number\n");
1002
exitcode = EXIT_FAILURE;
1006
address = connect_to;
1007
ret = start_mandos_communication(address, port, if_index, &mc);
1507
perror_plus("asprintf");
1511
fprintf_plus(stderr, "Running network hook \"%s\"\n",
1514
pid_t hook_pid = fork();
1517
/* Raise privileges */
1518
raise_privileges_permanently();
1523
perror_plus("setgid");
1525
/* Reset supplementary groups */
1527
ret = setgroups(0, NULL);
1529
perror_plus("setgroups");
1531
dup2(devnull, STDIN_FILENO);
1533
dup2(STDERR_FILENO, STDOUT_FILENO);
1534
ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);
1536
perror_plus("setenv");
1539
ret = setenv("DEVICE", interface, 1);
1541
perror_plus("setenv");
1544
ret = setenv("VERBOSITY", debug ? "1" : "0", 1);
1546
perror_plus("setenv");
1549
ret = setenv("MODE", mode, 1);
1551
perror_plus("setenv");
1555
ret = asprintf(&delaystring, "%f", delay);
1557
perror_plus("asprintf");
1560
ret = setenv("DELAY", delaystring, 1);
1563
perror_plus("setenv");
1567
if(connect_to != NULL){
1568
ret = setenv("CONNECT", connect_to, 1);
1570
perror_plus("setenv");
1009
exitcode = EXIT_FAILURE;
1011
exitcode = EXIT_SUCCESS;
1017
avahi_set_log_function(empty_log);
1020
/* Initialize the pseudo-RNG for Avahi */
1021
srand((unsigned int) time(NULL));
1023
/* Allocate main Avahi loop object */
1024
mc.simple_poll = avahi_simple_poll_new();
1025
if (mc.simple_poll == NULL) {
1026
fprintf(stderr, "Avahi: Failed to create simple poll"
1028
exitcode = EXIT_FAILURE;
1033
AvahiServerConfig config;
1034
/* Do not publish any local Zeroconf records */
1035
avahi_server_config_init(&config);
1036
config.publish_hinfo = 0;
1037
config.publish_addresses = 0;
1038
config.publish_workstation = 0;
1039
config.publish_domain = 0;
1041
/* Allocate a new server */
1042
mc.server = avahi_server_new(avahi_simple_poll_get
1043
(mc.simple_poll), &config, NULL,
1046
/* Free the Avahi configuration data */
1047
avahi_server_config_free(&config);
1050
/* Check if creating the Avahi server object succeeded */
1051
if (mc.server == NULL) {
1052
fprintf(stderr, "Failed to create Avahi server: %s\n",
1053
avahi_strerror(error));
1054
exitcode = EXIT_FAILURE;
1058
/* Create the Avahi service browser */
1059
sb = avahi_s_service_browser_new(mc.server, if_index,
1061
"_mandos._tcp", NULL, 0,
1062
browse_callback, &mc);
1064
fprintf(stderr, "Failed to create service browser: %s\n",
1065
avahi_strerror(avahi_server_errno(mc.server)));
1066
exitcode = EXIT_FAILURE;
1070
/* Run the main loop */
1073
fprintf(stderr, "Starting Avahi loop search\n");
1076
avahi_simple_poll_loop(mc.simple_poll);
1081
fprintf(stderr, "%s exiting\n", argv[0]);
1084
/* Cleanup things */
1086
avahi_s_service_browser_free(sb);
1088
if (mc.server != NULL)
1089
avahi_server_free(mc.server);
1091
if (mc.simple_poll != NULL)
1092
avahi_simple_poll_free(mc.simple_poll);
1094
if (gnutls_initalized){
1095
gnutls_certificate_free_credentials(mc.cred);
1096
gnutls_global_deinit ();
1097
gnutls_dh_params_deinit(mc.dh_params);
1100
if(gpgme_initalized){
1101
gpgme_release(mc.ctx);
1104
/* Removes the temp directory used by GPGME */
1105
if(tempdir[0] != '\0'){
1107
struct dirent *direntry;
1108
d = opendir(tempdir);
1110
if(errno != ENOENT){
1115
direntry = readdir(d);
1116
if(direntry == NULL){
1574
if(execl(fullname, direntry->d_name, mode, NULL) == -1){
1575
perror_plus("execl");
1576
_exit(EXIT_FAILURE);
1580
if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){
1581
perror_plus("waitpid");
1585
if(WIFEXITED(status)){
1586
if(WEXITSTATUS(status) != 0){
1587
fprintf_plus(stderr, "Warning: network hook \"%s\" exited"
1588
" with status %d\n", direntry->d_name,
1589
WEXITSTATUS(status));
1119
if (direntry->d_type == DT_REG){
1120
char *fullname = NULL;
1121
ret = asprintf(&fullname, "%s/%s", tempdir,
1127
ret = unlink(fullname);
1129
fprintf(stderr, "unlink(\"%s\"): %s",
1130
fullname, strerror(errno));
1590
1132
free(fullname);
1593
} else if(WIFSIGNALED(status)){
1594
fprintf_plus(stderr, "Warning: network hook \"%s\" died by"
1595
" signal %d\n", direntry->d_name,
1600
fprintf_plus(stderr, "Warning: network hook \"%s\""
1601
" crashed\n", direntry->d_name);
1608
fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",
1617
error_t bring_up_interface(const char *const interface,
1620
error_t old_errno = errno;
1621
error_t ret_errno = 0;
1622
int ret, ret_setflags;
1623
struct ifreq network;
1624
unsigned int if_index = if_nametoindex(interface);
1626
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1636
if(not interface_is_up(interface)){
1637
if(not get_flags(interface, &network) and debug){
1639
fprintf_plus(stderr, "Failed to get flags for interface "
1640
"\"%s\"\n", interface);
1643
network.ifr_flags |= IFF_UP;
1645
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1648
perror_plus("socket");
1660
fprintf_plus(stderr, "Bringing up interface \"%s\"\n",
1664
/* Raise priviliges */
1668
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1669
messages about the network interface to mess up the prompt */
1670
int ret_linux = klogctl(8, NULL, 5);
1671
bool restore_loglevel = true;
1672
if(ret_linux == -1){
1673
restore_loglevel = false;
1674
perror_plus("klogctl");
1676
#endif /* __linux__ */
1677
ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1680
if(restore_loglevel){
1681
ret_linux = klogctl(7, NULL, 0);
1682
if(ret_linux == -1){
1683
perror_plus("klogctl");
1686
#endif /* __linux__ */
1688
/* Lower privileges */
1691
/* Close the socket */
1692
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1694
perror_plus("close");
1697
if(ret_setflags == -1){
1699
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1704
fprintf_plus(stderr, "Interface \"%s\" is already up; good\n",
1708
/* Sleep checking until interface is running.
1709
Check every 0.25s, up to total time of delay */
1710
for(int i=0; i < delay * 4; i++){
1711
if(interface_is_running(interface)){
1714
struct timespec sleeptime = { .tv_nsec = 250000000 };
1715
ret = nanosleep(&sleeptime, NULL);
1716
if(ret == -1 and errno != EINTR){
1717
perror_plus("nanosleep");
1725
error_t take_down_interface(const char *const interface){
1727
error_t old_errno = errno;
1728
error_t ret_errno = 0;
1729
int ret, ret_setflags;
1730
struct ifreq network;
1731
unsigned int if_index = if_nametoindex(interface);
1733
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1737
if(interface_is_up(interface)){
1738
if(not get_flags(interface, &network) and debug){
1740
fprintf_plus(stderr, "Failed to get flags for interface "
1741
"\"%s\"\n", interface);
1744
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1746
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1749
perror_plus("socket");
1755
fprintf_plus(stderr, "Taking down interface \"%s\"\n",
1759
/* Raise priviliges */
1762
ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1765
/* Lower privileges */
1768
/* Close the socket */
1769
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1771
perror_plus("close");
1774
if(ret_setflags == -1){
1776
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
1781
fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",
1789
int main(int argc, char *argv[]){
1790
mandos_context mc = { .server = NULL, .dh_bits = 1024,
1791
.priority = "SECURE256:!CTYPE-X.509:"
1792
"+CTYPE-OPENPGP", .current_server = NULL,
1793
.interfaces = NULL, .interfaces_size = 0 };
1794
AvahiSServiceBrowser *sb = NULL;
1799
int exitcode = EXIT_SUCCESS;
1800
char *interfaces_to_take_down = NULL;
1801
size_t interfaces_to_take_down_size = 0;
1802
char tempdir[] = "/tmp/mandosXXXXXX";
1803
bool tempdir_created = false;
1804
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
1805
const char *seckey = PATHDIR "/" SECKEY;
1806
const char *pubkey = PATHDIR "/" PUBKEY;
1807
char *interfaces_hooks = NULL;
1808
size_t interfaces_hooks_size = 0;
1810
bool gnutls_initialized = false;
1811
bool gpgme_initialized = false;
1813
double retry_interval = 10; /* 10s between trying a server and
1814
retrying the same server again */
1816
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
1817
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
1822
/* Lower any group privileges we might have, just to be safe */
1826
perror_plus("setgid");
1829
/* Lower user privileges (temporarily) */
1833
perror_plus("seteuid");
1841
struct argp_option options[] = {
1842
{ .name = "debug", .key = 128,
1843
.doc = "Debug mode", .group = 3 },
1844
{ .name = "connect", .key = 'c',
1845
.arg = "ADDRESS:PORT",
1846
.doc = "Connect directly to a specific Mandos server",
1848
{ .name = "interface", .key = 'i',
1850
.doc = "Network interface that will be used to search for"
1853
{ .name = "seckey", .key = 's',
1855
.doc = "OpenPGP secret key file base name",
1857
{ .name = "pubkey", .key = 'p',
1859
.doc = "OpenPGP public key file base name",
1861
{ .name = "dh-bits", .key = 129,
1863
.doc = "Bit length of the prime number used in the"
1864
" Diffie-Hellman key exchange",
1866
{ .name = "priority", .key = 130,
1868
.doc = "GnuTLS priority string for the TLS handshake",
1870
{ .name = "delay", .key = 131,
1872
.doc = "Maximum delay to wait for interface startup",
1874
{ .name = "retry", .key = 132,
1876
.doc = "Retry interval used when denied by the Mandos server",
1878
{ .name = "network-hook-dir", .key = 133,
1880
.doc = "Directory where network hooks are located",
1883
* These reproduce what we would get without ARGP_NO_HELP
1885
{ .name = "help", .key = '?',
1886
.doc = "Give this help list", .group = -1 },
1887
{ .name = "usage", .key = -3,
1888
.doc = "Give a short usage message", .group = -1 },
1889
{ .name = "version", .key = 'V',
1890
.doc = "Print program version", .group = -1 },
1894
error_t parse_opt(int key, char *arg,
1895
struct argp_state *state){
1898
case 128: /* --debug */
1901
case 'c': /* --connect */
1904
case 'i': /* --interface */
1905
ret_errno = argz_add_sep(&mc.interfaces, &mc.interfaces_size,
1908
argp_error(state, "%s", strerror(ret_errno));
1911
case 's': /* --seckey */
1914
case 'p': /* --pubkey */
1917
case 129: /* --dh-bits */
1919
tmpmax = strtoimax(arg, &tmp, 10);
1920
if(errno != 0 or tmp == arg or *tmp != '\0'
1921
or tmpmax != (typeof(mc.dh_bits))tmpmax){
1922
argp_error(state, "Bad number of DH bits");
1924
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
1926
case 130: /* --priority */
1929
case 131: /* --delay */
1931
delay = strtof(arg, &tmp);
1932
if(errno != 0 or tmp == arg or *tmp != '\0'){
1933
argp_error(state, "Bad delay");
1935
case 132: /* --retry */
1937
retry_interval = strtod(arg, &tmp);
1938
if(errno != 0 or tmp == arg or *tmp != '\0'
1939
or (retry_interval * 1000) > INT_MAX
1940
or retry_interval < 0){
1941
argp_error(state, "Bad retry interval");
1944
case 133: /* --network-hook-dir */
1948
* These reproduce what we would get without ARGP_NO_HELP
1950
case '?': /* --help */
1951
argp_state_help(state, state->out_stream,
1952
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
1953
& ~(unsigned int)ARGP_HELP_EXIT_OK);
1954
case -3: /* --usage */
1955
argp_state_help(state, state->out_stream,
1956
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
1957
case 'V': /* --version */
1958
fprintf_plus(state->out_stream, "%s\n", argp_program_version);
1959
exit(argp_err_exit_status);
1962
return ARGP_ERR_UNKNOWN;
1967
struct argp argp = { .options = options, .parser = parse_opt,
1969
.doc = "Mandos client -- Get and decrypt"
1970
" passwords from a Mandos server" };
1971
ret = argp_parse(&argp, argc, argv,
1972
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
1979
perror_plus("argp_parse");
1980
exitcode = EX_OSERR;
1983
exitcode = EX_USAGE;
1989
/* Work around Debian bug #633582:
1990
<http://bugs.debian.org/633582> */
1992
/* Re-raise priviliges */
1993
if(raise_privileges() == 0){
1996
if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){
1997
int seckey_fd = open(seckey, O_RDONLY);
1998
if(seckey_fd == -1){
1999
perror_plus("open");
2001
ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));
2003
perror_plus("fstat");
2005
if(S_ISREG(st.st_mode)
2006
and st.st_uid == 0 and st.st_gid == 0){
2007
ret = fchown(seckey_fd, uid, gid);
2009
perror_plus("fchown");
2013
TEMP_FAILURE_RETRY(close(seckey_fd));
2017
if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){
2018
int pubkey_fd = open(pubkey, O_RDONLY);
2019
if(pubkey_fd == -1){
2020
perror_plus("open");
2022
ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));
2024
perror_plus("fstat");
2026
if(S_ISREG(st.st_mode)
2027
and st.st_uid == 0 and st.st_gid == 0){
2028
ret = fchown(pubkey_fd, uid, gid);
2030
perror_plus("fchown");
2034
TEMP_FAILURE_RETRY(close(pubkey_fd));
2038
/* Lower privileges */
2043
/* Remove invalid interface names (except "none") */
2045
char *interface = NULL;
2046
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2048
if(strcmp(interface, "none") != 0
2049
and if_nametoindex(interface) == 0){
2050
if(interface[0] != '\0'){
2051
fprintf_plus(stderr, "Not using nonexisting interface"
2052
" \"%s\"\n", interface);
2054
argz_delete(&mc.interfaces, &mc.interfaces_size, interface);
2060
/* Run network hooks */
2062
if(mc.interfaces != NULL){
2063
interfaces_hooks = malloc(mc.interfaces_size);
2064
if(interfaces_hooks == NULL){
2065
perror_plus("malloc");
2068
memcpy(interfaces_hooks, mc.interfaces, mc.interfaces_size);
2069
interfaces_hooks_size = mc.interfaces_size;
2070
argz_stringify(interfaces_hooks, interfaces_hooks_size,
2073
if(not run_network_hooks("start", interfaces_hooks != NULL ?
2074
interfaces_hooks : "", delay)){
2080
avahi_set_log_function(empty_log);
2083
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
2084
from the signal handler */
2085
/* Initialize the pseudo-RNG for Avahi */
2086
srand((unsigned int) time(NULL));
2087
simple_poll = avahi_simple_poll_new();
2088
if(simple_poll == NULL){
2089
fprintf_plus(stderr,
2090
"Avahi: Failed to create simple poll object.\n");
2091
exitcode = EX_UNAVAILABLE;
2095
sigemptyset(&sigterm_action.sa_mask);
2096
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
2098
perror_plus("sigaddset");
2099
exitcode = EX_OSERR;
2102
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
2104
perror_plus("sigaddset");
2105
exitcode = EX_OSERR;
2108
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
2110
perror_plus("sigaddset");
2111
exitcode = EX_OSERR;
2114
/* Need to check if the handler is SIG_IGN before handling:
2115
| [[info:libc:Initial Signal Actions]] |
2116
| [[info:libc:Basic Signal Handling]] |
2118
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
2120
perror_plus("sigaction");
2123
if(old_sigterm_action.sa_handler != SIG_IGN){
2124
ret = sigaction(SIGINT, &sigterm_action, NULL);
2126
perror_plus("sigaction");
2127
exitcode = EX_OSERR;
2131
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
2133
perror_plus("sigaction");
2136
if(old_sigterm_action.sa_handler != SIG_IGN){
2137
ret = sigaction(SIGHUP, &sigterm_action, NULL);
2139
perror_plus("sigaction");
2140
exitcode = EX_OSERR;
2144
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
2146
perror_plus("sigaction");
2149
if(old_sigterm_action.sa_handler != SIG_IGN){
2150
ret = sigaction(SIGTERM, &sigterm_action, NULL);
2152
perror_plus("sigaction");
2153
exitcode = EX_OSERR;
2158
/* If no interfaces were specified, make a list */
2159
if(mc.interfaces == NULL){
2160
struct dirent **direntries;
2161
/* Look for any good interfaces */
2162
ret = scandir(sys_class_net, &direntries, good_interface,
2165
/* Add all found interfaces to interfaces list */
2166
for(int i = 0; i < ret; ++i){
2167
ret_errno = argz_add(&mc.interfaces, &mc.interfaces_size,
2168
direntries[i]->d_name);
2170
perror_plus("argz_add");
2174
fprintf_plus(stderr, "Will use interface \"%s\"\n",
2175
direntries[i]->d_name);
2181
fprintf_plus(stderr, "Could not find a network interface\n");
2182
exitcode = EXIT_FAILURE;
2187
/* Bring up interfaces which are down, and remove any "none"s */
2189
char *interface = NULL;
2190
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2192
/* If interface name is "none", stop bringing up interfaces.
2193
Also remove all instances of "none" from the list */
2194
if(strcmp(interface, "none") == 0){
2195
argz_delete(&mc.interfaces, &mc.interfaces_size,
2198
while((interface = argz_next(mc.interfaces,
2199
mc.interfaces_size, interface))){
2200
if(strcmp(interface, "none") == 0){
2201
argz_delete(&mc.interfaces, &mc.interfaces_size,
2208
bool interface_was_up = interface_is_up(interface);
2209
ret = bring_up_interface(interface, delay);
2210
if(not interface_was_up){
2213
perror_plus("Failed to bring up interface");
2215
ret_errno = argz_add(&interfaces_to_take_down,
2216
&interfaces_to_take_down_size,
2221
if(debug and (interfaces_to_take_down == NULL)){
2222
fprintf_plus(stderr, "No interfaces were brought up\n");
2226
/* If we only got one interface, explicitly use only that one */
2227
if(argz_count(mc.interfaces, mc.interfaces_size) == 1){
2229
fprintf_plus(stderr, "Using only interface \"%s\"\n",
2232
if_index = (AvahiIfIndex)if_nametoindex(mc.interfaces);
2239
ret = init_gnutls_global(pubkey, seckey, &mc);
2241
fprintf_plus(stderr, "init_gnutls_global failed\n");
2242
exitcode = EX_UNAVAILABLE;
2245
gnutls_initialized = true;
2252
if(mkdtemp(tempdir) == NULL){
2253
perror_plus("mkdtemp");
2256
tempdir_created = true;
2262
if(not init_gpgme(pubkey, seckey, tempdir, &mc)){
2263
fprintf_plus(stderr, "init_gpgme failed\n");
2264
exitcode = EX_UNAVAILABLE;
2267
gpgme_initialized = true;
2274
if(connect_to != NULL){
2275
/* Connect directly, do not use Zeroconf */
2276
/* (Mainly meant for debugging) */
2277
char *address = strrchr(connect_to, ':');
2279
if(address == NULL){
2280
fprintf_plus(stderr, "No colon in address\n");
2281
exitcode = EX_USAGE;
2291
tmpmax = strtoimax(address+1, &tmp, 10);
2292
if(errno != 0 or tmp == address+1 or *tmp != '\0'
2293
or tmpmax != (in_port_t)tmpmax){
2294
fprintf_plus(stderr, "Bad port number\n");
2295
exitcode = EX_USAGE;
2303
port = (in_port_t)tmpmax;
2305
/* Colon in address indicates IPv6 */
2307
if(strchr(connect_to, ':') != NULL){
2309
/* Accept [] around IPv6 address - see RFC 5952 */
2310
if(connect_to[0] == '[' and address[-1] == ']')
2318
address = connect_to;
2324
while(not quit_now){
2325
ret = start_mandos_communication(address, port, if_index, af,
2327
if(quit_now or ret == 0){
2331
fprintf_plus(stderr, "Retrying in %d seconds\n",
2332
(int)retry_interval);
2334
sleep((int)retry_interval);
2338
exitcode = EXIT_SUCCESS;
2349
AvahiServerConfig config;
2350
/* Do not publish any local Zeroconf records */
2351
avahi_server_config_init(&config);
2352
config.publish_hinfo = 0;
2353
config.publish_addresses = 0;
2354
config.publish_workstation = 0;
2355
config.publish_domain = 0;
2357
/* Allocate a new server */
2358
mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),
2359
&config, NULL, NULL, &ret_errno);
2361
/* Free the Avahi configuration data */
2362
avahi_server_config_free(&config);
2365
/* Check if creating the Avahi server object succeeded */
2366
if(mc.server == NULL){
2367
fprintf_plus(stderr, "Failed to create Avahi server: %s\n",
2368
avahi_strerror(ret_errno));
2369
exitcode = EX_UNAVAILABLE;
2377
/* Create the Avahi service browser */
2378
sb = avahi_s_service_browser_new(mc.server, if_index,
2379
AVAHI_PROTO_UNSPEC, "_mandos._tcp",
2380
NULL, 0, browse_callback,
2383
fprintf_plus(stderr, "Failed to create service browser: %s\n",
2384
avahi_strerror(avahi_server_errno(mc.server)));
2385
exitcode = EX_UNAVAILABLE;
2393
/* Run the main loop */
2396
fprintf_plus(stderr, "Starting Avahi loop search\n");
2399
ret = avahi_loop_with_timeout(simple_poll,
2400
(int)(retry_interval * 1000), &mc);
2402
fprintf_plus(stderr, "avahi_loop_with_timeout exited %s\n",
2403
(ret == 0) ? "successfully" : "with error");
2409
fprintf_plus(stderr, "%s exiting\n", argv[0]);
2412
/* Cleanup things */
2413
free(mc.interfaces);
2416
avahi_s_service_browser_free(sb);
2418
if(mc.server != NULL)
2419
avahi_server_free(mc.server);
2421
if(simple_poll != NULL)
2422
avahi_simple_poll_free(simple_poll);
2424
if(gnutls_initialized){
2425
gnutls_certificate_free_credentials(mc.cred);
2426
gnutls_global_deinit();
2427
gnutls_dh_params_deinit(mc.dh_params);
2430
if(gpgme_initialized){
2431
gpgme_release(mc.ctx);
2434
/* Cleans up the circular linked list of Mandos servers the client
2436
if(mc.current_server != NULL){
2437
mc.current_server->prev->next = NULL;
2438
while(mc.current_server != NULL){
2439
server *next = mc.current_server->next;
2440
free(mc.current_server);
2441
mc.current_server = next;
2445
/* Re-raise priviliges */
2449
/* Run network hooks */
2450
run_network_hooks("stop", interfaces_hooks != NULL ?
2451
interfaces_hooks : "", delay);
2453
/* Take down the network interfaces which were brought up */
2455
char *interface = NULL;
2456
while((interface=argz_next(interfaces_to_take_down,
2457
interfaces_to_take_down_size,
2459
ret_errno = take_down_interface(interface);
2462
perror_plus("Failed to take down interface");
2465
if(debug and (interfaces_to_take_down == NULL)){
2466
fprintf_plus(stderr, "No interfaces needed to be taken"
2471
lower_privileges_permanently();
2474
free(interfaces_to_take_down);
2475
free(interfaces_hooks);
2477
/* Removes the GPGME temp directory and all files inside */
2478
if(tempdir_created){
2479
struct dirent **direntries = NULL;
2480
struct dirent *direntry = NULL;
2481
int numentries = scandir(tempdir, &direntries, notdotentries,
2483
if (numentries > 0){
2484
for(int i = 0; i < numentries; i++){
2485
direntry = direntries[i];
2486
char *fullname = NULL;
2487
ret = asprintf(&fullname, "%s/%s", tempdir,
2490
perror_plus("asprintf");
2493
ret = remove(fullname);
2495
fprintf_plus(stderr, "remove(\"%s\"): %s\n", fullname,
2502
/* need to clean even if 0 because man page doesn't specify */
2504
if (numentries == -1){
2505
perror_plus("scandir");
2507
ret = rmdir(tempdir);
2508
if(ret == -1 and errno != ENOENT){
2509
perror_plus("rmdir");
2514
sigemptyset(&old_sigterm_action.sa_mask);
2515
old_sigterm_action.sa_handler = SIG_DFL;
2516
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
2517
&old_sigterm_action,
2520
perror_plus("sigaction");
2523
ret = raise(signal_received);
2524
} while(ret != 0 and errno == EINTR);
2526
perror_plus("raise");
2529
TEMP_FAILURE_RETRY(pause());
1137
ret = rmdir(tempdir);
1138
if(ret == -1 and errno != ENOENT){