625
501
/* Called when a Mandos server is found */
626
502
static int start_mandos_communication(const char *ip, uint16_t port,
627
503
AvahiIfIndex if_index,
629
int ret, tcp_sd = -1;
632
struct sockaddr_in in;
633
struct sockaddr_in6 in6;
506
union { struct sockaddr in; struct sockaddr_in6 in6; } to;
635
507
char *buffer = NULL;
636
char *decrypted_buffer = NULL;
508
char *decrypted_buffer;
637
509
size_t buffer_length = 0;
638
510
size_t buffer_capacity = 0;
511
ssize_t decrypted_buffer_size;
514
char interface[IF_NAMESIZE];
641
515
gnutls_session_t session;
642
int pf; /* Protocol family */
659
fprintf_plus(stderr, "Bad address family: %d\n", af);
664
ret = init_gnutls_session(&session);
670
fprintf_plus(stderr, "Setting up a TCP connection to %s, port %"
671
PRIu16 "\n", ip, port);
674
tcp_sd = socket(pf, SOCK_STREAM, 0);
677
perror_plus("socket");
517
ret = init_gnutls_session (mc, &session);
523
fprintf(stderr, "Setting up a tcp connection to %s, port %" PRIu16
527
tcp_sd = socket(PF_INET6, SOCK_STREAM, 0);
534
if(if_indextoname((unsigned int)if_index, interface) == NULL){
535
perror("if_indextoname");
538
fprintf(stderr, "Binding to interface %s\n", interface);
687
541
memset(&to, 0, sizeof(to));
689
to.in6.sin6_family = (sa_family_t)af;
690
ret = inet_pton(af, ip, &to.in6.sin6_addr);
692
to.in.sin_family = (sa_family_t)af;
693
ret = inet_pton(af, ip, &to.in.sin_addr);
697
perror_plus("inet_pton");
542
to.in6.sin6_family = AF_INET6;
543
/* It would be nice to have a way to detect if we were passed an
544
IPv4 address here. Now we assume an IPv6 address. */
545
ret = inet_pton(AF_INET6, ip, &to.in6.sin6_addr);
703
fprintf_plus(stderr, "Bad address: %s\n", ip);
708
to.in6.sin6_port = htons(port); /* Spurious warnings from
710
-Wunreachable-code */
712
if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */
713
(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower and
715
if(if_index == AVAHI_IF_UNSPEC){
716
fprintf_plus(stderr, "An IPv6 link-local address is"
717
" incomplete without a network interface\n");
721
/* Set the network interface number as scope */
722
to.in6.sin6_scope_id = (uint32_t)if_index;
725
to.in.sin_port = htons(port); /* Spurious warnings from
727
-Wunreachable-code */
551
fprintf(stderr, "Bad address: %s\n", ip);
554
to.in6.sin6_port = htons(port); /* Spurious warning */
556
to.in6.sin6_scope_id = (uint32_t)if_index;
736
if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){
737
char interface[IF_NAMESIZE];
738
if(if_indextoname((unsigned int)if_index, interface) == NULL){
739
perror_plus("if_indextoname");
741
fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIu16
742
"\n", ip, interface, port);
745
fprintf_plus(stderr, "Connection to: %s, port %" PRIu16 "\n",
748
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
749
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
752
pcret = inet_ntop(af, &(to.in6.sin6_addr), addrstr,
755
pcret = inet_ntop(af, &(to.in.sin_addr), addrstr,
759
perror_plus("inet_ntop");
559
fprintf(stderr, "Connection to: %s, port %" PRIu16 "\n", ip,
561
char addrstr[INET6_ADDRSTRLEN] = "";
562
if(inet_ntop(to.in6.sin6_family, &(to.in6.sin6_addr), addrstr,
563
sizeof(addrstr)) == NULL){
761
566
if(strcmp(addrstr, ip) != 0){
762
fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);
567
fprintf(stderr, "Canonical address form: %s\n", addrstr);
773
ret = connect(tcp_sd, &to.in6, sizeof(to));
775
ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */
778
if ((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){
780
perror_plus("connect");
572
ret = connect(tcp_sd, &to.in, sizeof(to));
791
578
const char *out = mandos_protocol_version;
794
581
size_t out_size = strlen(out);
795
ret = (int)TEMP_FAILURE_RETRY(write(tcp_sd, out + written,
796
out_size - written));
799
perror_plus("write");
582
ret = TEMP_FAILURE_RETRY(write(tcp_sd, out + written,
583
out_size - written));
803
589
written += (size_t)ret;
804
590
if(written < out_size){
807
if(out == mandos_protocol_version){
593
if (out == mandos_protocol_version){
822
fprintf_plus(stderr, "Establishing TLS session with %s\n", ip);
830
/* This casting via intptr_t is to eliminate warning about casting
831
an int to a pointer type. This is exactly how the GnuTLS Guile
832
function "set-session-transport-fd!" does it. */
833
gnutls_transport_set_ptr(session,
834
(gnutls_transport_ptr_t)(intptr_t)tcp_sd);
842
ret = gnutls_handshake(session);
603
fprintf(stderr, "Establishing TLS session with %s\n", ip);
606
gnutls_transport_set_ptr (session, (gnutls_transport_ptr_t) tcp_sd);
609
ret = gnutls_handshake (session);
847
610
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
849
if(ret != GNUTLS_E_SUCCESS){
612
if (ret != GNUTLS_E_SUCCESS){
851
fprintf_plus(stderr, "*** GnuTLS Handshake failed ***\n");
614
fprintf(stderr, "*** GnuTLS Handshake failed ***\n");
858
621
/* Read OpenPGP packet that contains the wanted password */
861
fprintf_plus(stderr, "Retrieving OpenPGP encrypted password from"
624
fprintf(stderr, "Retrieving pgp encrypted password from %s\n",
872
buffer_capacity = incbuffer(&buffer, buffer_length,
874
if(buffer_capacity == 0){
876
perror_plus("incbuffer");
886
sret = gnutls_record_recv(session, buffer+buffer_length,
629
buffer_capacity = adjustbuffer(&buffer, buffer_length,
631
if (buffer_capacity == 0){
632
perror("adjustbuffer");
637
ret = gnutls_record_recv(session, buffer+buffer_length,
893
644
case GNUTLS_E_INTERRUPTED:
894
645
case GNUTLS_E_AGAIN:
896
647
case GNUTLS_E_REHANDSHAKE:
898
ret = gnutls_handshake(session);
649
ret = gnutls_handshake (session);
904
650
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
906
fprintf_plus(stderr, "*** GnuTLS Re-handshake failed "
652
fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");
914
fprintf_plus(stderr, "Unknown error while reading data from"
915
" encrypted session with Mandos server\n");
916
gnutls_bye(session, GNUTLS_SHUT_RDWR);
659
fprintf(stderr, "Unknown error while reading data from"
660
" encrypted session with Mandos server\n");
662
gnutls_bye (session, GNUTLS_SHUT_RDWR);
921
buffer_length += (size_t) sret;
666
buffer_length += (size_t) ret;
926
fprintf_plus(stderr, "Closing TLS session\n");
935
ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);
940
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
942
if(buffer_length > 0){
943
ssize_t decrypted_buffer_size;
944
decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,
671
fprintf(stderr, "Closing TLS session\n");
674
gnutls_bye (session, GNUTLS_SHUT_RDWR);
676
if (buffer_length > 0){
677
decrypted_buffer_size = pgp_packet_decrypt(mc, buffer,
945
679
&decrypted_buffer);
946
if(decrypted_buffer_size >= 0){
680
if (decrypted_buffer_size >= 0){
949
682
while(written < (size_t) decrypted_buffer_size){
955
ret = (int)fwrite(decrypted_buffer + written, 1,
956
(size_t)decrypted_buffer_size - written,
683
ret = (int)fwrite (decrypted_buffer + written, 1,
684
(size_t)decrypted_buffer_size - written,
958
686
if(ret == 0 and ferror(stdout)){
961
fprintf_plus(stderr, "Error writing encrypted data: %s\n",
688
fprintf(stderr, "Error writing encrypted data: %s\n",
967
694
written += (size_t)ret;
696
free(decrypted_buffer);
973
704
/* Shutdown procedure */
978
free(decrypted_buffer);
981
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
987
perror_plus("close");
989
gnutls_deinit(session);
708
ret = TEMP_FAILURE_RETRY(close(tcp_sd));
712
gnutls_deinit (session);
999
716
static void resolve_callback(AvahiSServiceResolver *r,
1000
717
AvahiIfIndex interface,
1001
AvahiProtocol proto,
718
AVAHI_GCC_UNUSED AvahiProtocol protocol,
1002
719
AvahiResolverEvent event,
1003
720
const char *name,
1004
721
const char *type,
1101
804
case AVAHI_BROWSER_ALL_FOR_NOW:
1102
805
case AVAHI_BROWSER_CACHE_EXHAUSTED:
1104
fprintf_plus(stderr, "No Mandos server found, still"
807
fprintf(stderr, "No Mandos server found, still searching...\n");
1111
/* Signal handler that stops main loop after SIGTERM */
1112
static void handle_sigterm(int sig){
1117
signal_received = sig;
1118
int old_errno = errno;
1119
/* set main loop to exit */
1120
if(mc.simple_poll != NULL){
1121
avahi_simple_poll_quit(mc.simple_poll);
1126
bool get_flags(const char *ifname, struct ifreq *ifr){
1130
int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1133
perror_plus("socket");
1137
strcpy(ifr->ifr_name, ifname);
1138
ret = ioctl(s, SIOCGIFFLAGS, ifr);
1142
perror_plus("ioctl SIOCGIFFLAGS");
1150
bool good_flags(const char *ifname, const struct ifreq *ifr){
1152
/* Reject the loopback device */
1153
if(ifr->ifr_flags & IFF_LOOPBACK){
1155
fprintf_plus(stderr, "Rejecting loopback interface \"%s\"\n",
1160
/* Accept point-to-point devices only if connect_to is specified */
1161
if(connect_to != NULL and (ifr->ifr_flags & IFF_POINTOPOINT)){
1163
fprintf_plus(stderr, "Accepting point-to-point interface"
1164
" \"%s\"\n", ifname);
1168
/* Otherwise, reject non-broadcast-capable devices */
1169
if(not (ifr->ifr_flags & IFF_BROADCAST)){
1171
fprintf_plus(stderr, "Rejecting non-broadcast interface"
1172
" \"%s\"\n", ifname);
1176
/* Reject non-ARP interfaces (including dummy interfaces) */
1177
if(ifr->ifr_flags & IFF_NOARP){
1179
fprintf_plus(stderr, "Rejecting non-ARP interface \"%s\"\n",
1185
/* Accept this device */
1187
fprintf_plus(stderr, "Interface \"%s\" is good\n", ifname);
1193
* This function determines if a directory entry in /sys/class/net
1194
* corresponds to an acceptable network device.
1195
* (This function is passed to scandir(3) as a filter function.)
1197
int good_interface(const struct dirent *if_entry){
1198
if(if_entry->d_name[0] == '.'){
1203
if(not get_flags(if_entry->d_name, &ifr)){
1205
fprintf_plus(stderr, "Failed to get flags for interface "
1206
"\"%s\"\n", if_entry->d_name);
1211
if(not good_flags(if_entry->d_name, &ifr)){
1218
* This function determines if a network interface is up.
1220
bool interface_is_up(const char *interface){
1222
if(not get_flags(interface, &ifr)){
1224
fprintf_plus(stderr, "Failed to get flags for interface "
1225
"\"%s\"\n", interface);
1230
return (bool)(ifr.ifr_flags & IFF_UP);
1234
* This function determines if a network interface is running
1236
bool interface_is_running(const char *interface){
1238
if(not get_flags(interface, &ifr)){
1240
fprintf_plus(stderr, "Failed to get flags for interface "
1241
"\"%s\"\n", interface);
1246
return (bool)(ifr.ifr_flags & IFF_RUNNING);
1249
int notdotentries(const struct dirent *direntry){
1250
/* Skip "." and ".." */
1251
if(direntry->d_name[0] == '.'
1252
and (direntry->d_name[1] == '\0'
1253
or (direntry->d_name[1] == '.'
1254
and direntry->d_name[2] == '\0'))){
1260
/* Is this directory entry a runnable program? */
1261
int runnable_hook(const struct dirent *direntry){
1266
if((direntry->d_name)[0] == '\0'){
1271
sret = strspn(direntry->d_name, "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
1272
"abcdefghijklmnopqrstuvwxyz"
1275
if((direntry->d_name)[sret] != '\0'){
1276
/* Contains non-allowed characters */
1278
fprintf_plus(stderr, "Ignoring hook \"%s\" with bad name\n",
1284
char *fullname = NULL;
1285
ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);
1287
perror_plus("asprintf");
1291
ret = stat(fullname, &st);
1294
perror_plus("Could not stat hook");
1298
if(not (S_ISREG(st.st_mode))){
1299
/* Not a regular file */
1301
fprintf_plus(stderr, "Ignoring hook \"%s\" - not a file\n",
1306
if(not (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))){
1307
/* Not executable */
1309
fprintf_plus(stderr, "Ignoring hook \"%s\" - not executable\n",
1315
fprintf_plus(stderr, "Hook \"%s\" is acceptable\n",
1321
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){
1323
struct timespec now;
1324
struct timespec waited_time;
1325
intmax_t block_time;
1328
if(mc.current_server == NULL){
1330
fprintf_plus(stderr, "Wait until first server is found."
1333
ret = avahi_simple_poll_iterate(s, -1);
1336
fprintf_plus(stderr, "Check current_server if we should run"
1339
/* the current time */
1340
ret = clock_gettime(CLOCK_MONOTONIC, &now);
813
int main(int argc, char *argv[]){
814
AvahiSServiceBrowser *sb = NULL;
817
int exitcode = EXIT_SUCCESS;
818
const char *interface = "eth0";
819
struct ifreq network;
823
char *connect_to = NULL;
824
char tempdir[] = "/tmp/mandosXXXXXX";
825
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
826
const char *seckey = PATHDIR "/" SECKEY;
827
const char *pubkey = PATHDIR "/" PUBKEY;
829
mandos_context mc = { .simple_poll = NULL, .server = NULL,
830
.dh_bits = 1024, .priority = "SECURE256"
831
":!CTYPE-X.509:+CTYPE-OPENPGP" };
832
bool gnutls_initalized = false;
833
bool pgpme_initalized = false;
836
struct argp_option options[] = {
837
{ .name = "debug", .key = 128,
838
.doc = "Debug mode", .group = 3 },
839
{ .name = "connect", .key = 'c',
840
.arg = "ADDRESS:PORT",
841
.doc = "Connect directly to a specific Mandos server",
843
{ .name = "interface", .key = 'i',
845
.doc = "Interface that will be used to search for Mandos"
848
{ .name = "seckey", .key = 's',
850
.doc = "OpenPGP secret key file base name",
852
{ .name = "pubkey", .key = 'p',
854
.doc = "OpenPGP public key file base name",
856
{ .name = "dh-bits", .key = 129,
858
.doc = "Bit length of the prime number used in the"
859
" Diffie-Hellman key exchange",
861
{ .name = "priority", .key = 130,
863
.doc = "GnuTLS priority string for the TLS handshake",
868
error_t parse_opt (int key, char *arg,
869
struct argp_state *state) {
870
/* Get the INPUT argument from `argp_parse', which we know is
871
a pointer to our plugin list pointer. */
873
case 128: /* --debug */
876
case 'c': /* --connect */
879
case 'i': /* --interface */
882
case 's': /* --seckey */
885
case 'p': /* --pubkey */
888
case 129: /* --dh-bits */
890
mc.dh_bits = (unsigned int) strtol(arg, NULL, 10);
896
case 130: /* --priority */
904
return ARGP_ERR_UNKNOWN;
909
struct argp argp = { .options = options, .parser = parse_opt,
911
.doc = "Mandos client -- Get and decrypt"
912
" passwords from a Mandos server" };
913
ret = argp_parse (&argp, argc, argv, 0, 0, NULL);
914
if (ret == ARGP_ERR_UNKNOWN){
915
fprintf(stderr, "Unknown error while parsing arguments\n");
916
exitcode = EXIT_FAILURE;
921
/* If the interface is down, bring it up */
923
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
926
exitcode = EXIT_FAILURE;
929
strcpy(network.ifr_name, interface);
930
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1342
perror_plus("clock_gettime");
1345
/* Calculating in ms how long time between now and server
1346
who we visted longest time ago. Now - last seen. */
1347
waited_time.tv_sec = (now.tv_sec
1348
- mc.current_server->last_seen.tv_sec);
1349
waited_time.tv_nsec = (now.tv_nsec
1350
- mc.current_server->last_seen.tv_nsec);
1351
/* total time is 10s/10,000ms.
1352
Converting to s from ms by dividing by 1,000,
1353
and ns to ms by dividing by 1,000,000. */
1354
block_time = ((retry_interval
1355
- ((intmax_t)waited_time.tv_sec * 1000))
1356
- ((intmax_t)waited_time.tv_nsec / 1000000));
1359
fprintf_plus(stderr, "Blocking for %" PRIdMAX " ms\n",
1363
if(block_time <= 0){
1364
ret = start_mandos_communication(mc.current_server->ip,
1365
mc.current_server->port,
1366
mc.current_server->if_index,
1367
mc.current_server->af);
1369
avahi_simple_poll_quit(mc.simple_poll);
1372
ret = clock_gettime(CLOCK_MONOTONIC,
1373
&mc.current_server->last_seen);
932
perror("ioctl SIOCGIFFLAGS");
933
exitcode = EXIT_FAILURE;
936
if((network.ifr_flags & IFF_UP) == 0){
937
network.ifr_flags |= IFF_UP;
938
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1375
perror_plus("clock_gettime");
940
perror("ioctl SIOCSIFFLAGS");
941
exitcode = EXIT_FAILURE;
1378
mc.current_server = mc.current_server->next;
1379
block_time = 0; /* Call avahi to find new Mandos
1380
servers, but don't block */
1383
ret = avahi_simple_poll_iterate(s, (int)block_time);
1386
if (ret > 0 or errno != EINTR){
1387
return (ret != 1) ? ret : 0;
1393
/* Set effective uid to 0, return errno */
1394
error_t raise_privileges(void){
1395
error_t old_errno = errno;
1396
error_t ret_errno = 0;
1397
if(seteuid(0) == -1){
1399
perror_plus("seteuid");
1405
/* Set effective and real user ID to 0. Return errno. */
1406
error_t raise_privileges_permanently(void){
1407
error_t old_errno = errno;
1408
error_t ret_errno = raise_privileges();
1413
if(setuid(0) == -1){
1415
perror_plus("seteuid");
1421
/* Set effective user ID to unprivileged saved user ID */
1422
error_t lower_privileges(void){
1423
error_t old_errno = errno;
1424
error_t ret_errno = 0;
1425
if(seteuid(uid) == -1){
1427
perror_plus("seteuid");
1433
/* Lower privileges permanently */
1434
error_t lower_privileges_permanently(void){
1435
error_t old_errno = errno;
1436
error_t ret_errno = 0;
1437
if(setuid(uid) == -1){
1439
perror_plus("setuid");
1445
bool run_network_hooks(const char *mode, const char *interface,
1447
struct dirent **direntries;
1448
struct dirent *direntry;
1450
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1453
perror_plus("scandir");
1455
int devnull = open("/dev/null", O_RDONLY);
1456
for(int i = 0; i < numhooks; i++){
1457
direntry = direntries[i];
1458
char *fullname = NULL;
1459
ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);
945
ret = TEMP_FAILURE_RETRY(close(sd));
964
ret = init_gnutls_global(&mc, pubkey, seckey);
966
fprintf(stderr, "init_gnutls_global failed\n");
967
exitcode = EXIT_FAILURE;
970
gnutls_initalized = true;
973
if(mkdtemp(tempdir) == NULL){
979
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
980
fprintf(stderr, "pgpme_initalized failed\n");
981
exitcode = EXIT_FAILURE;
984
pgpme_initalized = true;
987
if_index = (AvahiIfIndex) if_nametoindex(interface);
989
fprintf(stderr, "No such interface: \"%s\"\n", interface);
993
if(connect_to != NULL){
994
/* Connect directly, do not use Zeroconf */
995
/* (Mainly meant for debugging) */
996
char *address = strrchr(connect_to, ':');
998
fprintf(stderr, "No colon in address\n");
999
exitcode = EXIT_FAILURE;
1003
uint16_t port = (uint16_t) strtol(address+1, NULL, 10);
1005
perror("Bad port number");
1006
exitcode = EXIT_FAILURE;
1010
address = connect_to;
1011
ret = start_mandos_communication(address, port, if_index, &mc);
1461
perror_plus("asprintf");
1465
fprintf_plus(stderr, "Running network hook \"%s\"\n",
1468
pid_t hook_pid = fork();
1471
/* Raise privileges */
1472
raise_privileges_permanently();
1477
perror_plus("setgid");
1479
/* Reset supplementary groups */
1481
ret = setgroups(0, NULL);
1483
perror_plus("setgroups");
1485
dup2(devnull, STDIN_FILENO);
1487
dup2(STDERR_FILENO, STDOUT_FILENO);
1488
ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);
1490
perror_plus("setenv");
1493
ret = setenv("DEVICE", interface, 1);
1495
perror_plus("setenv");
1498
ret = setenv("VERBOSITY", debug ? "1" : "0", 1);
1500
perror_plus("setenv");
1503
ret = setenv("MODE", mode, 1);
1505
perror_plus("setenv");
1509
ret = asprintf(&delaystring, "%f", delay);
1511
perror_plus("asprintf");
1514
ret = setenv("DELAY", delaystring, 1);
1517
perror_plus("setenv");
1521
if(connect_to != NULL){
1522
ret = setenv("CONNECT", connect_to, 1);
1524
perror_plus("setenv");
1013
exitcode = EXIT_FAILURE;
1015
exitcode = EXIT_SUCCESS;
1021
avahi_set_log_function(empty_log);
1024
/* Initialize the pseudo-RNG for Avahi */
1025
srand((unsigned int) time(NULL));
1027
/* Allocate main Avahi loop object */
1028
mc.simple_poll = avahi_simple_poll_new();
1029
if (mc.simple_poll == NULL) {
1030
fprintf(stderr, "Avahi: Failed to create simple poll"
1032
exitcode = EXIT_FAILURE;
1037
AvahiServerConfig config;
1038
/* Do not publish any local Zeroconf records */
1039
avahi_server_config_init(&config);
1040
config.publish_hinfo = 0;
1041
config.publish_addresses = 0;
1042
config.publish_workstation = 0;
1043
config.publish_domain = 0;
1045
/* Allocate a new server */
1046
mc.server = avahi_server_new(avahi_simple_poll_get
1047
(mc.simple_poll), &config, NULL,
1050
/* Free the Avahi configuration data */
1051
avahi_server_config_free(&config);
1054
/* Check if creating the Avahi server object succeeded */
1055
if (mc.server == NULL) {
1056
fprintf(stderr, "Failed to create Avahi server: %s\n",
1057
avahi_strerror(error));
1058
exitcode = EXIT_FAILURE;
1062
/* Create the Avahi service browser */
1063
sb = avahi_s_service_browser_new(mc.server, if_index,
1065
"_mandos._tcp", NULL, 0,
1066
browse_callback, &mc);
1068
fprintf(stderr, "Failed to create service browser: %s\n",
1069
avahi_strerror(avahi_server_errno(mc.server)));
1070
exitcode = EXIT_FAILURE;
1074
/* Run the main loop */
1077
fprintf(stderr, "Starting Avahi loop search\n");
1080
avahi_simple_poll_loop(mc.simple_poll);
1085
fprintf(stderr, "%s exiting\n", argv[0]);
1088
/* Cleanup things */
1090
avahi_s_service_browser_free(sb);
1092
if (mc.server != NULL)
1093
avahi_server_free(mc.server);
1095
if (mc.simple_poll != NULL)
1096
avahi_simple_poll_free(mc.simple_poll);
1098
if (gnutls_initalized){
1099
gnutls_certificate_free_credentials(mc.cred);
1100
gnutls_global_deinit ();
1103
if(pgpme_initalized){
1104
gpgme_release(mc.ctx);
1107
/* Removes the temp directory used by GPGME */
1108
if(tempdir[0] != '\0'){
1110
struct dirent *direntry;
1111
d = opendir(tempdir);
1116
direntry = readdir(d);
1117
if(direntry == NULL){
1528
if(execl(fullname, direntry->d_name, mode, NULL) == -1){
1529
perror_plus("execl");
1530
_exit(EXIT_FAILURE);
1534
if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){
1535
perror_plus("waitpid");
1539
if(WIFEXITED(status)){
1540
if(WEXITSTATUS(status) != 0){
1541
fprintf_plus(stderr, "Warning: network hook \"%s\" exited"
1542
" with status %d\n", direntry->d_name,
1543
WEXITSTATUS(status));
1120
if (direntry->d_type == DT_REG){
1121
char *fullname = NULL;
1122
ret = asprintf(&fullname, "%s/%s", tempdir,
1128
ret = unlink(fullname);
1130
fprintf(stderr, "unlink(\"%s\"): %s",
1131
fullname, strerror(errno));
1544
1133
free(fullname);
1547
} else if(WIFSIGNALED(status)){
1548
fprintf_plus(stderr, "Warning: network hook \"%s\" died by"
1549
" signal %d\n", direntry->d_name,
1554
fprintf_plus(stderr, "Warning: network hook \"%s\""
1555
" crashed\n", direntry->d_name);
1562
fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",
1571
error_t bring_up_interface(const char *const interface,
1574
error_t old_errno = errno;
1575
error_t ret_errno = 0;
1576
int ret, ret_setflags;
1577
struct ifreq network;
1578
unsigned int if_index = if_nametoindex(interface);
1580
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1590
if(not interface_is_up(interface)){
1591
if(not get_flags(interface, &network) and debug){
1593
fprintf_plus(stderr, "Failed to get flags for interface "
1594
"\"%s\"\n", interface);
1597
network.ifr_flags |= IFF_UP;
1599
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1602
perror_plus("socket");
1614
fprintf_plus(stderr, "Bringing up interface \"%s\"\n",
1618
/* Raise priviliges */
1622
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1623
messages about the network interface to mess up the prompt */
1624
int ret_linux = klogctl(8, NULL, 5);
1625
bool restore_loglevel = true;
1626
if(ret_linux == -1){
1627
restore_loglevel = false;
1628
perror_plus("klogctl");
1630
#endif /* __linux__ */
1631
ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1634
if(restore_loglevel){
1635
ret_linux = klogctl(7, NULL, 0);
1636
if(ret_linux == -1){
1637
perror_plus("klogctl");
1640
#endif /* __linux__ */
1642
/* Lower privileges */
1645
/* Close the socket */
1646
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1648
perror_plus("close");
1651
if(ret_setflags == -1){
1653
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1658
fprintf_plus(stderr, "Interface \"%s\" is already up; good\n",
1662
/* Sleep checking until interface is running.
1663
Check every 0.25s, up to total time of delay */
1664
for(int i=0; i < delay * 4; i++){
1665
if(interface_is_running(interface)){
1668
struct timespec sleeptime = { .tv_nsec = 250000000 };
1669
ret = nanosleep(&sleeptime, NULL);
1670
if(ret == -1 and errno != EINTR){
1671
perror_plus("nanosleep");
1679
error_t take_down_interface(const char *const interface){
1681
error_t old_errno = errno;
1682
error_t ret_errno = 0;
1683
int ret, ret_setflags;
1684
struct ifreq network;
1685
unsigned int if_index = if_nametoindex(interface);
1687
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1691
if(interface_is_up(interface)){
1692
if(not get_flags(interface, &network) and debug){
1694
fprintf_plus(stderr, "Failed to get flags for interface "
1695
"\"%s\"\n", interface);
1698
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1700
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1703
perror_plus("socket");
1709
fprintf_plus(stderr, "Taking down interface \"%s\"\n",
1713
/* Raise priviliges */
1716
ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1719
/* Lower privileges */
1722
/* Close the socket */
1723
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1725
perror_plus("close");
1728
if(ret_setflags == -1){
1730
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
1735
fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",
1743
int main(int argc, char *argv[]){
1744
AvahiSServiceBrowser *sb = NULL;
1749
int exitcode = EXIT_SUCCESS;
1750
char *interfaces = NULL;
1751
size_t interfaces_size = 0;
1752
char *interfaces_to_take_down = NULL;
1753
size_t interfaces_to_take_down_size = 0;
1754
char tempdir[] = "/tmp/mandosXXXXXX";
1755
bool tempdir_created = false;
1756
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
1757
const char *seckey = PATHDIR "/" SECKEY;
1758
const char *pubkey = PATHDIR "/" PUBKEY;
1759
char *interfaces_hooks = NULL;
1760
size_t interfaces_hooks_size = 0;
1762
bool gnutls_initialized = false;
1763
bool gpgme_initialized = false;
1765
double retry_interval = 10; /* 10s between trying a server and
1766
retrying the same server again */
1768
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
1769
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
1774
/* Lower any group privileges we might have, just to be safe */
1778
perror_plus("setgid");
1781
/* Lower user privileges (temporarily) */
1785
perror_plus("seteuid");
1793
struct argp_option options[] = {
1794
{ .name = "debug", .key = 128,
1795
.doc = "Debug mode", .group = 3 },
1796
{ .name = "connect", .key = 'c',
1797
.arg = "ADDRESS:PORT",
1798
.doc = "Connect directly to a specific Mandos server",
1800
{ .name = "interface", .key = 'i',
1802
.doc = "Network interface that will be used to search for"
1805
{ .name = "seckey", .key = 's',
1807
.doc = "OpenPGP secret key file base name",
1809
{ .name = "pubkey", .key = 'p',
1811
.doc = "OpenPGP public key file base name",
1813
{ .name = "dh-bits", .key = 129,
1815
.doc = "Bit length of the prime number used in the"
1816
" Diffie-Hellman key exchange",
1818
{ .name = "priority", .key = 130,
1820
.doc = "GnuTLS priority string for the TLS handshake",
1822
{ .name = "delay", .key = 131,
1824
.doc = "Maximum delay to wait for interface startup",
1826
{ .name = "retry", .key = 132,
1828
.doc = "Retry interval used when denied by the Mandos server",
1830
{ .name = "network-hook-dir", .key = 133,
1832
.doc = "Directory where network hooks are located",
1835
* These reproduce what we would get without ARGP_NO_HELP
1837
{ .name = "help", .key = '?',
1838
.doc = "Give this help list", .group = -1 },
1839
{ .name = "usage", .key = -3,
1840
.doc = "Give a short usage message", .group = -1 },
1841
{ .name = "version", .key = 'V',
1842
.doc = "Print program version", .group = -1 },
1846
error_t parse_opt(int key, char *arg,
1847
struct argp_state *state){
1850
case 128: /* --debug */
1853
case 'c': /* --connect */
1856
case 'i': /* --interface */
1857
ret_errno = argz_add_sep(&interfaces, &interfaces_size, arg,
1860
argp_error(state, "%s", strerror(ret_errno));
1863
case 's': /* --seckey */
1866
case 'p': /* --pubkey */
1869
case 129: /* --dh-bits */
1871
tmpmax = strtoimax(arg, &tmp, 10);
1872
if(errno != 0 or tmp == arg or *tmp != '\0'
1873
or tmpmax != (typeof(mc.dh_bits))tmpmax){
1874
argp_error(state, "Bad number of DH bits");
1876
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
1878
case 130: /* --priority */
1881
case 131: /* --delay */
1883
delay = strtof(arg, &tmp);
1884
if(errno != 0 or tmp == arg or *tmp != '\0'){
1885
argp_error(state, "Bad delay");
1887
case 132: /* --retry */
1889
retry_interval = strtod(arg, &tmp);
1890
if(errno != 0 or tmp == arg or *tmp != '\0'
1891
or (retry_interval * 1000) > INT_MAX
1892
or retry_interval < 0){
1893
argp_error(state, "Bad retry interval");
1896
case 133: /* --network-hook-dir */
1900
* These reproduce what we would get without ARGP_NO_HELP
1902
case '?': /* --help */
1903
argp_state_help(state, state->out_stream,
1904
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
1905
& ~(unsigned int)ARGP_HELP_EXIT_OK);
1906
case -3: /* --usage */
1907
argp_state_help(state, state->out_stream,
1908
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
1909
case 'V': /* --version */
1910
fprintf_plus(state->out_stream, "%s\n", argp_program_version);
1911
exit(argp_err_exit_status);
1914
return ARGP_ERR_UNKNOWN;
1919
struct argp argp = { .options = options, .parser = parse_opt,
1921
.doc = "Mandos client -- Get and decrypt"
1922
" passwords from a Mandos server" };
1923
ret = argp_parse(&argp, argc, argv,
1924
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
1931
perror_plus("argp_parse");
1932
exitcode = EX_OSERR;
1935
exitcode = EX_USAGE;
1941
/* Work around Debian bug #633582:
1942
<http://bugs.debian.org/633582> */
1944
/* Re-raise priviliges */
1945
if(raise_privileges() == 0){
1948
if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){
1949
int seckey_fd = open(seckey, O_RDONLY);
1950
if(seckey_fd == -1){
1951
perror_plus("open");
1953
ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));
1955
perror_plus("fstat");
1957
if(S_ISREG(st.st_mode)
1958
and st.st_uid == 0 and st.st_gid == 0){
1959
ret = fchown(seckey_fd, uid, gid);
1961
perror_plus("fchown");
1965
TEMP_FAILURE_RETRY(close(seckey_fd));
1969
if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){
1970
int pubkey_fd = open(pubkey, O_RDONLY);
1971
if(pubkey_fd == -1){
1972
perror_plus("open");
1974
ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));
1976
perror_plus("fstat");
1978
if(S_ISREG(st.st_mode)
1979
and st.st_uid == 0 and st.st_gid == 0){
1980
ret = fchown(pubkey_fd, uid, gid);
1982
perror_plus("fchown");
1986
TEMP_FAILURE_RETRY(close(pubkey_fd));
1990
/* Lower privileges */
1137
ret = rmdir(tempdir);
1994
perror_plus("seteuid");
1999
/* Remove empty interface names */
2001
char *interface = NULL;
2002
while((interface = argz_next(interfaces, interfaces_size,
2004
if(if_nametoindex(interface) == 0){
2005
if(interface[0] != '\0' and strcmp(interface, "none") != 0){
2006
fprintf_plus(stderr, "Not using nonexisting interface"
2007
" \"%s\"\n", interface);
2009
argz_delete(&interfaces, &interfaces_size, interface);
2015
/* Run network hooks */
2017
ret_errno = argz_append(&interfaces_hooks, &interfaces_hooks_size,
2018
interfaces, interfaces_size);
2021
perror_plus("argz_append");
2024
argz_stringify(interfaces_hooks, interfaces_hooks_size, (int)',');
2025
if(not run_network_hooks("start", interfaces_hooks, delay)){
2031
avahi_set_log_function(empty_log);
2034
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
2035
from the signal handler */
2036
/* Initialize the pseudo-RNG for Avahi */
2037
srand((unsigned int) time(NULL));
2038
mc.simple_poll = avahi_simple_poll_new();
2039
if(mc.simple_poll == NULL){
2040
fprintf_plus(stderr,
2041
"Avahi: Failed to create simple poll object.\n");
2042
exitcode = EX_UNAVAILABLE;
2046
sigemptyset(&sigterm_action.sa_mask);
2047
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
2049
perror_plus("sigaddset");
2050
exitcode = EX_OSERR;
2053
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
2055
perror_plus("sigaddset");
2056
exitcode = EX_OSERR;
2059
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
2061
perror_plus("sigaddset");
2062
exitcode = EX_OSERR;
2065
/* Need to check if the handler is SIG_IGN before handling:
2066
| [[info:libc:Initial Signal Actions]] |
2067
| [[info:libc:Basic Signal Handling]] |
2069
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
2071
perror_plus("sigaction");
2074
if(old_sigterm_action.sa_handler != SIG_IGN){
2075
ret = sigaction(SIGINT, &sigterm_action, NULL);
2077
perror_plus("sigaction");
2078
exitcode = EX_OSERR;
2082
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
2084
perror_plus("sigaction");
2087
if(old_sigterm_action.sa_handler != SIG_IGN){
2088
ret = sigaction(SIGHUP, &sigterm_action, NULL);
2090
perror_plus("sigaction");
2091
exitcode = EX_OSERR;
2095
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
2097
perror_plus("sigaction");
2100
if(old_sigterm_action.sa_handler != SIG_IGN){
2101
ret = sigaction(SIGTERM, &sigterm_action, NULL);
2103
perror_plus("sigaction");
2104
exitcode = EX_OSERR;
2109
/* If no interfaces were specified, make a list */
2110
if(interfaces == NULL){
2111
struct dirent **direntries;
2112
/* Look for any good interfaces */
2113
ret = scandir(sys_class_net, &direntries, good_interface,
2116
/* Add all found interfaces to interfaces list */
2117
for(int i = 0; i < ret; ++i){
2118
ret_errno = argz_add(&interfaces, &interfaces_size,
2119
direntries[i]->d_name);
2121
perror_plus("argz_add");
2125
fprintf_plus(stderr, "Will use interface \"%s\"\n",
2126
direntries[i]->d_name);
2132
fprintf_plus(stderr, "Could not find a network interface\n");
2133
exitcode = EXIT_FAILURE;
2138
/* If we only got one interface, explicitly use only that one */
2139
if(argz_count(interfaces, interfaces_size) == 1){
2141
fprintf_plus(stderr, "Using only interface \"%s\"\n",
2144
if_index = (AvahiIfIndex)if_nametoindex(interfaces);
2147
/* Bring up interfaces which are down */
2148
if(not (argz_count(interfaces, interfaces_size) == 1
2149
and strcmp(interfaces, "none") == 0)){
2150
char *interface = NULL;
2151
while((interface = argz_next(interfaces, interfaces_size,
2153
bool interface_was_up = interface_is_up(interface);
2154
ret = bring_up_interface(interface, delay);
2155
if(not interface_was_up){
2158
perror_plus("Failed to bring up interface");
2160
ret_errno = argz_add(&interfaces_to_take_down,
2161
&interfaces_to_take_down_size,
2168
interfaces_size = 0;
2169
if(debug and (interfaces_to_take_down == NULL)){
2170
fprintf_plus(stderr, "No interfaces were brought up\n");
2178
ret = init_gnutls_global(pubkey, seckey);
2180
fprintf_plus(stderr, "init_gnutls_global failed\n");
2181
exitcode = EX_UNAVAILABLE;
2184
gnutls_initialized = true;
2191
if(mkdtemp(tempdir) == NULL){
2192
perror_plus("mkdtemp");
2195
tempdir_created = true;
2201
if(not init_gpgme(pubkey, seckey, tempdir)){
2202
fprintf_plus(stderr, "init_gpgme failed\n");
2203
exitcode = EX_UNAVAILABLE;
2206
gpgme_initialized = true;
2213
if(connect_to != NULL){
2214
/* Connect directly, do not use Zeroconf */
2215
/* (Mainly meant for debugging) */
2216
char *address = strrchr(connect_to, ':');
2218
if(address == NULL){
2219
fprintf_plus(stderr, "No colon in address\n");
2220
exitcode = EX_USAGE;
2230
tmpmax = strtoimax(address+1, &tmp, 10);
2231
if(errno != 0 or tmp == address+1 or *tmp != '\0'
2232
or tmpmax != (uint16_t)tmpmax){
2233
fprintf_plus(stderr, "Bad port number\n");
2234
exitcode = EX_USAGE;
2242
port = (uint16_t)tmpmax;
2244
/* Colon in address indicates IPv6 */
2246
if(strchr(connect_to, ':') != NULL){
2248
/* Accept [] around IPv6 address - see RFC 5952 */
2249
if(connect_to[0] == '[' and address[-1] == ']')
2257
address = connect_to;
2263
while(not quit_now){
2264
ret = start_mandos_communication(address, port, if_index, af);
2265
if(quit_now or ret == 0){
2269
fprintf_plus(stderr, "Retrying in %d seconds\n",
2270
(int)retry_interval);
2272
sleep((int)retry_interval);
2276
exitcode = EXIT_SUCCESS;
2287
AvahiServerConfig config;
2288
/* Do not publish any local Zeroconf records */
2289
avahi_server_config_init(&config);
2290
config.publish_hinfo = 0;
2291
config.publish_addresses = 0;
2292
config.publish_workstation = 0;
2293
config.publish_domain = 0;
2295
/* Allocate a new server */
2296
mc.server = avahi_server_new(avahi_simple_poll_get
2297
(mc.simple_poll), &config, NULL,
2300
/* Free the Avahi configuration data */
2301
avahi_server_config_free(&config);
2304
/* Check if creating the Avahi server object succeeded */
2305
if(mc.server == NULL){
2306
fprintf_plus(stderr, "Failed to create Avahi server: %s\n",
2307
avahi_strerror(ret_errno));
2308
exitcode = EX_UNAVAILABLE;
2316
/* Create the Avahi service browser */
2317
sb = avahi_s_service_browser_new(mc.server, if_index,
2318
AVAHI_PROTO_UNSPEC, "_mandos._tcp",
2319
NULL, 0, browse_callback, NULL);
2321
fprintf_plus(stderr, "Failed to create service browser: %s\n",
2322
avahi_strerror(avahi_server_errno(mc.server)));
2323
exitcode = EX_UNAVAILABLE;
2331
/* Run the main loop */
2334
fprintf_plus(stderr, "Starting Avahi loop search\n");
2337
ret = avahi_loop_with_timeout(mc.simple_poll,
2338
(int)(retry_interval * 1000));
2340
fprintf_plus(stderr, "avahi_loop_with_timeout exited %s\n",
2341
(ret == 0) ? "successfully" : "with error");
2347
fprintf_plus(stderr, "%s exiting\n", argv[0]);
2350
/* Cleanup things */
2352
avahi_s_service_browser_free(sb);
2354
if(mc.server != NULL)
2355
avahi_server_free(mc.server);
2357
if(mc.simple_poll != NULL)
2358
avahi_simple_poll_free(mc.simple_poll);
2360
if(gnutls_initialized){
2361
gnutls_certificate_free_credentials(mc.cred);
2362
gnutls_global_deinit();
2363
gnutls_dh_params_deinit(mc.dh_params);
2366
if(gpgme_initialized){
2367
gpgme_release(mc.ctx);
2370
/* Cleans up the circular linked list of Mandos servers the client
2372
if(mc.current_server != NULL){
2373
mc.current_server->prev->next = NULL;
2374
while(mc.current_server != NULL){
2375
server *next = mc.current_server->next;
2376
free(mc.current_server);
2377
mc.current_server = next;
2381
/* Re-raise priviliges */
2385
/* Run network hooks */
2386
run_network_hooks("stop", interfaces_hooks, delay);
2388
/* Take down the network interfaces which were brought up */
2390
char *interface = NULL;
2391
while((interface=argz_next(interfaces_to_take_down,
2392
interfaces_to_take_down_size,
2394
ret_errno = take_down_interface(interface);
2397
perror_plus("Failed to take down interface");
2400
if(debug and (interfaces_to_take_down == NULL)){
2401
fprintf_plus(stderr, "No interfaces needed to be taken"
2406
lower_privileges_permanently();
2409
free(interfaces_to_take_down);
2410
free(interfaces_hooks);
2412
/* Removes the GPGME temp directory and all files inside */
2413
if(tempdir_created){
2414
struct dirent **direntries = NULL;
2415
struct dirent *direntry = NULL;
2416
int numentries = scandir(tempdir, &direntries, notdotentries,
2418
if (numentries > 0){
2419
for(int i = 0; i < numentries; i++){
2420
direntry = direntries[i];
2421
char *fullname = NULL;
2422
ret = asprintf(&fullname, "%s/%s", tempdir,
2425
perror_plus("asprintf");
2428
ret = remove(fullname);
2430
fprintf_plus(stderr, "remove(\"%s\"): %s\n", fullname,
2437
/* need to clean even if 0 because man page doesn't specify */
2439
if (numentries == -1){
2440
perror_plus("scandir");
2442
ret = rmdir(tempdir);
2443
if(ret == -1 and errno != ENOENT){
2444
perror_plus("rmdir");
2449
sigemptyset(&old_sigterm_action.sa_mask);
2450
old_sigterm_action.sa_handler = SIG_DFL;
2451
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
2452
&old_sigterm_action,
2455
perror_plus("sigaction");
2458
ret = raise(signal_received);
2459
} while(ret != 0 and errno == EINTR);
2461
perror_plus("raise");
2464
TEMP_FAILURE_RETRY(pause());