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
ret = init_gnutls_session(&session, mc);
668
fprintf_plus(stderr, "Setting up a TCP connection to %s, port %"
669
PRIuMAX "\n", ip, (uintmax_t)port);
672
tcp_sd = socket(pf, SOCK_STREAM, 0);
675
perror_plus("socket");
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");
537
fprintf(stderr, "Binding to interface %s\n", interface);
685
540
memset(&to, 0, sizeof(to));
687
to.in6.sin6_family = (sa_family_t)af;
688
ret = inet_pton(af, ip, &to.in6.sin6_addr);
690
to.in.sin_family = (sa_family_t)af;
691
ret = inet_pton(af, ip, &to.in.sin_addr);
695
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);
701
fprintf_plus(stderr, "Bad address: %s\n", ip);
706
to.in6.sin6_port = htons(port);
707
if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */
708
(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower and
710
if(if_index == AVAHI_IF_UNSPEC){
711
fprintf_plus(stderr, "An IPv6 link-local address is"
712
" incomplete without a network interface\n");
716
/* Set the network interface number as scope */
717
to.in6.sin6_scope_id = (uint32_t)if_index;
720
to.in.sin_port = htons(port); /* Spurious warnings from
722
-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;
731
if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){
732
char interface[IF_NAMESIZE];
733
if(if_indextoname((unsigned int)if_index, interface) == NULL){
734
perror_plus("if_indextoname");
736
fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIuMAX
737
"\n", ip, interface, (uintmax_t)port);
740
fprintf_plus(stderr, "Connection to: %s, port %" PRIuMAX "\n",
741
ip, (uintmax_t)port);
743
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
744
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
747
pcret = inet_ntop(af, &(to.in6.sin6_addr), addrstr,
750
pcret = inet_ntop(af, &(to.in.sin_addr), addrstr,
754
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){
756
565
if(strcmp(addrstr, ip) != 0){
757
fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);
566
fprintf(stderr, "Canonical address form: %s\n", addrstr);
768
ret = connect(tcp_sd, &to.in6, sizeof(to));
770
ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */
773
if ((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){
775
perror_plus("connect");
571
ret = connect(tcp_sd, &to.in, sizeof(to));
786
577
const char *out = mandos_protocol_version;
789
580
size_t out_size = strlen(out);
790
581
ret = (int)TEMP_FAILURE_RETRY(write(tcp_sd, out + written,
791
out_size - written));
794
perror_plus("write");
582
out_size - written));
798
588
written += (size_t)ret;
799
589
if(written < out_size){
802
if(out == mandos_protocol_version){
592
if (out == mandos_protocol_version){
817
fprintf_plus(stderr, "Establishing TLS session with %s\n", ip);
825
/* This casting via intptr_t is to eliminate warning about casting
826
an int to a pointer type. This is exactly how the GnuTLS Guile
827
function "set-session-transport-fd!" does it. */
828
gnutls_transport_set_ptr(session,
829
(gnutls_transport_ptr_t)(intptr_t)tcp_sd);
837
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);
842
609
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
844
if(ret != GNUTLS_E_SUCCESS){
611
if (ret != GNUTLS_E_SUCCESS){
846
fprintf_plus(stderr, "*** GnuTLS Handshake failed ***\n");
613
fprintf(stderr, "*** GnuTLS Handshake failed ***\n");
853
620
/* Read OpenPGP packet that contains the wanted password */
856
fprintf_plus(stderr, "Retrieving OpenPGP encrypted password from"
623
fprintf(stderr, "Retrieving pgp encrypted password from %s\n",
867
buffer_capacity = incbuffer(&buffer, buffer_length,
869
if(buffer_capacity == 0){
871
perror_plus("incbuffer");
628
buffer_capacity = adjustbuffer(&buffer, buffer_length,
630
if (buffer_capacity == 0){
631
perror("adjustbuffer");
881
636
sret = gnutls_record_recv(session, buffer+buffer_length,
888
643
case GNUTLS_E_INTERRUPTED:
889
644
case GNUTLS_E_AGAIN:
891
646
case GNUTLS_E_REHANDSHAKE:
893
ret = gnutls_handshake(session);
648
ret = gnutls_handshake (session);
899
649
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
901
fprintf_plus(stderr, "*** GnuTLS Re-handshake failed "
651
fprintf(stderr, "*** GnuTLS Re-handshake failed ***\n");
909
fprintf_plus(stderr, "Unknown error while reading data from"
910
" encrypted session with Mandos server\n");
911
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);
1107
803
case AVAHI_BROWSER_ALL_FOR_NOW:
1108
804
case AVAHI_BROWSER_CACHE_EXHAUSTED:
1110
fprintf_plus(stderr, "No Mandos server found, still"
806
fprintf(stderr, "No Mandos server found, still searching...\n");
1117
/* Signal handler that stops main loop after SIGTERM */
1118
static void handle_sigterm(int sig){
1123
signal_received = sig;
1124
int old_errno = errno;
1125
/* set main loop to exit */
1126
if(simple_poll != NULL){
1127
avahi_simple_poll_quit(simple_poll);
1132
bool get_flags(const char *ifname, struct ifreq *ifr){
1136
int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1139
perror_plus("socket");
1143
strcpy(ifr->ifr_name, ifname);
1144
ret = ioctl(s, SIOCGIFFLAGS, ifr);
1148
perror_plus("ioctl SIOCGIFFLAGS");
1156
bool good_flags(const char *ifname, const struct ifreq *ifr){
1158
/* Reject the loopback device */
1159
if(ifr->ifr_flags & IFF_LOOPBACK){
1161
fprintf_plus(stderr, "Rejecting loopback interface \"%s\"\n",
1166
/* Accept point-to-point devices only if connect_to is specified */
1167
if(connect_to != NULL and (ifr->ifr_flags & IFF_POINTOPOINT)){
1169
fprintf_plus(stderr, "Accepting point-to-point interface"
1170
" \"%s\"\n", ifname);
1174
/* Otherwise, reject non-broadcast-capable devices */
1175
if(not (ifr->ifr_flags & IFF_BROADCAST)){
1177
fprintf_plus(stderr, "Rejecting non-broadcast interface"
1178
" \"%s\"\n", ifname);
1182
/* Reject non-ARP interfaces (including dummy interfaces) */
1183
if(ifr->ifr_flags & IFF_NOARP){
1185
fprintf_plus(stderr, "Rejecting non-ARP interface \"%s\"\n",
1191
/* Accept this device */
1193
fprintf_plus(stderr, "Interface \"%s\" is good\n", ifname);
1199
* This function determines if a directory entry in /sys/class/net
1200
* corresponds to an acceptable network device.
1201
* (This function is passed to scandir(3) as a filter function.)
1203
int good_interface(const struct dirent *if_entry){
1204
if(if_entry->d_name[0] == '.'){
1209
if(not get_flags(if_entry->d_name, &ifr)){
1211
fprintf_plus(stderr, "Failed to get flags for interface "
1212
"\"%s\"\n", if_entry->d_name);
1217
if(not good_flags(if_entry->d_name, &ifr)){
1224
* This function determines if a network interface is up.
1226
bool interface_is_up(const char *interface){
1228
if(not get_flags(interface, &ifr)){
1230
fprintf_plus(stderr, "Failed to get flags for interface "
1231
"\"%s\"\n", interface);
1236
return (bool)(ifr.ifr_flags & IFF_UP);
1240
* This function determines if a network interface is running
1242
bool interface_is_running(const char *interface){
1244
if(not get_flags(interface, &ifr)){
1246
fprintf_plus(stderr, "Failed to get flags for interface "
1247
"\"%s\"\n", interface);
1252
return (bool)(ifr.ifr_flags & IFF_RUNNING);
1255
int notdotentries(const struct dirent *direntry){
1256
/* Skip "." and ".." */
1257
if(direntry->d_name[0] == '.'
1258
and (direntry->d_name[1] == '\0'
1259
or (direntry->d_name[1] == '.'
1260
and direntry->d_name[2] == '\0'))){
1266
/* Is this directory entry a runnable program? */
1267
int runnable_hook(const struct dirent *direntry){
1272
if((direntry->d_name)[0] == '\0'){
1277
sret = strspn(direntry->d_name, "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
1278
"abcdefghijklmnopqrstuvwxyz"
1281
if((direntry->d_name)[sret] != '\0'){
1282
/* Contains non-allowed characters */
1284
fprintf_plus(stderr, "Ignoring hook \"%s\" with bad name\n",
1290
char *fullname = NULL;
1291
ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);
1293
perror_plus("asprintf");
1297
ret = stat(fullname, &st);
1300
perror_plus("Could not stat hook");
1304
if(not (S_ISREG(st.st_mode))){
1305
/* Not a regular file */
1307
fprintf_plus(stderr, "Ignoring hook \"%s\" - not a file\n",
1312
if(not (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))){
1313
/* Not executable */
1315
fprintf_plus(stderr, "Ignoring hook \"%s\" - not executable\n",
1321
fprintf_plus(stderr, "Hook \"%s\" is acceptable\n",
1327
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,
1328
mandos_context *mc){
1330
struct timespec now;
1331
struct timespec waited_time;
1332
intmax_t block_time;
1335
if(mc->current_server == NULL){
1337
fprintf_plus(stderr, "Wait until first server is found."
1340
ret = avahi_simple_poll_iterate(s, -1);
1343
fprintf_plus(stderr, "Check current_server if we should run"
1346
/* the current time */
1347
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);
887
if(ret == 0 or mc.dh_bits == 0){
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);
1349
perror_plus("clock_gettime");
1352
/* Calculating in ms how long time between now and server
1353
who we visted longest time ago. Now - last seen. */
1354
waited_time.tv_sec = (now.tv_sec
1355
- mc->current_server->last_seen.tv_sec);
1356
waited_time.tv_nsec = (now.tv_nsec
1357
- mc->current_server->last_seen.tv_nsec);
1358
/* total time is 10s/10,000ms.
1359
Converting to s from ms by dividing by 1,000,
1360
and ns to ms by dividing by 1,000,000. */
1361
block_time = ((retry_interval
1362
- ((intmax_t)waited_time.tv_sec * 1000))
1363
- ((intmax_t)waited_time.tv_nsec / 1000000));
1366
fprintf_plus(stderr, "Blocking for %" PRIdMAX " ms\n",
1370
if(block_time <= 0){
1371
ret = start_mandos_communication(mc->current_server->ip,
1372
mc->current_server->port,
1373
mc->current_server->if_index,
1374
mc->current_server->af, mc);
1376
avahi_simple_poll_quit(s);
1379
ret = clock_gettime(CLOCK_MONOTONIC,
1380
&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);
1382
perror_plus("clock_gettime");
936
perror("ioctl SIOCSIFFLAGS");
937
exitcode = EXIT_FAILURE;
1385
mc->current_server = mc->current_server->next;
1386
block_time = 0; /* Call avahi to find new Mandos
1387
servers, but don't block */
1390
ret = avahi_simple_poll_iterate(s, (int)block_time);
1393
if (ret > 0 or errno != EINTR){
1394
return (ret != 1) ? ret : 0;
1400
/* Set effective uid to 0, return errno */
1401
error_t raise_privileges(void){
1402
error_t old_errno = errno;
1403
error_t ret_errno = 0;
1404
if(seteuid(0) == -1){
1406
perror_plus("seteuid");
1412
/* Set effective and real user ID to 0. Return errno. */
1413
error_t raise_privileges_permanently(void){
1414
error_t old_errno = errno;
1415
error_t ret_errno = raise_privileges();
1420
if(setuid(0) == -1){
1422
perror_plus("seteuid");
1428
/* Set effective user ID to unprivileged saved user ID */
1429
error_t lower_privileges(void){
1430
error_t old_errno = errno;
1431
error_t ret_errno = 0;
1432
if(seteuid(uid) == -1){
1434
perror_plus("seteuid");
1440
/* Lower privileges permanently */
1441
error_t lower_privileges_permanently(void){
1442
error_t old_errno = errno;
1443
error_t ret_errno = 0;
1444
if(setuid(uid) == -1){
1446
perror_plus("setuid");
1452
bool run_network_hooks(const char *mode, const char *interface,
1454
struct dirent **direntries;
1455
struct dirent *direntry;
1457
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1460
if(errno == ENOENT){
1462
fprintf_plus(stderr, "Network hook directory \"%s\" not"
1463
" found\n", hookdir);
1466
perror_plus("scandir");
1469
int devnull = open("/dev/null", O_RDONLY);
1470
for(int i = 0; i < numhooks; i++){
1471
direntry = direntries[i];
1472
char *fullname = NULL;
1473
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);
1000
if(ret == 0 or port == 0){
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);
1475
perror_plus("asprintf");
1479
fprintf_plus(stderr, "Running network hook \"%s\"\n",
1482
pid_t hook_pid = fork();
1485
/* Raise privileges */
1486
raise_privileges_permanently();
1491
perror_plus("setgid");
1493
/* Reset supplementary groups */
1495
ret = setgroups(0, NULL);
1497
perror_plus("setgroups");
1499
dup2(devnull, STDIN_FILENO);
1501
dup2(STDERR_FILENO, STDOUT_FILENO);
1502
ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);
1504
perror_plus("setenv");
1507
ret = setenv("DEVICE", interface, 1);
1509
perror_plus("setenv");
1512
ret = setenv("VERBOSITY", debug ? "1" : "0", 1);
1514
perror_plus("setenv");
1517
ret = setenv("MODE", mode, 1);
1519
perror_plus("setenv");
1523
ret = asprintf(&delaystring, "%f", delay);
1525
perror_plus("asprintf");
1528
ret = setenv("DELAY", delaystring, 1);
1531
perror_plus("setenv");
1535
if(connect_to != NULL){
1536
ret = setenv("CONNECT", connect_to, 1);
1538
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){
1542
if(execl(fullname, direntry->d_name, mode, NULL) == -1){
1543
perror_plus("execl");
1544
_exit(EXIT_FAILURE);
1548
if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){
1549
perror_plus("waitpid");
1553
if(WIFEXITED(status)){
1554
if(WEXITSTATUS(status) != 0){
1555
fprintf_plus(stderr, "Warning: network hook \"%s\" exited"
1556
" with status %d\n", direntry->d_name,
1557
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));
1558
1132
free(fullname);
1561
} else if(WIFSIGNALED(status)){
1562
fprintf_plus(stderr, "Warning: network hook \"%s\" died by"
1563
" signal %d\n", direntry->d_name,
1568
fprintf_plus(stderr, "Warning: network hook \"%s\""
1569
" crashed\n", direntry->d_name);
1576
fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",
1585
error_t bring_up_interface(const char *const interface,
1588
error_t old_errno = errno;
1589
error_t ret_errno = 0;
1590
int ret, ret_setflags;
1591
struct ifreq network;
1592
unsigned int if_index = if_nametoindex(interface);
1594
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1604
if(not interface_is_up(interface)){
1605
if(not get_flags(interface, &network) and debug){
1607
fprintf_plus(stderr, "Failed to get flags for interface "
1608
"\"%s\"\n", interface);
1611
network.ifr_flags |= IFF_UP;
1613
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1616
perror_plus("socket");
1628
fprintf_plus(stderr, "Bringing up interface \"%s\"\n",
1632
/* Raise priviliges */
1636
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1637
messages about the network interface to mess up the prompt */
1638
int ret_linux = klogctl(8, NULL, 5);
1639
bool restore_loglevel = true;
1640
if(ret_linux == -1){
1641
restore_loglevel = false;
1642
perror_plus("klogctl");
1644
#endif /* __linux__ */
1645
ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1648
if(restore_loglevel){
1649
ret_linux = klogctl(7, NULL, 0);
1650
if(ret_linux == -1){
1651
perror_plus("klogctl");
1654
#endif /* __linux__ */
1656
/* Lower privileges */
1659
/* Close the socket */
1660
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1662
perror_plus("close");
1665
if(ret_setflags == -1){
1667
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1672
fprintf_plus(stderr, "Interface \"%s\" is already up; good\n",
1676
/* Sleep checking until interface is running.
1677
Check every 0.25s, up to total time of delay */
1678
for(int i=0; i < delay * 4; i++){
1679
if(interface_is_running(interface)){
1682
struct timespec sleeptime = { .tv_nsec = 250000000 };
1683
ret = nanosleep(&sleeptime, NULL);
1684
if(ret == -1 and errno != EINTR){
1685
perror_plus("nanosleep");
1693
error_t take_down_interface(const char *const interface){
1695
error_t old_errno = errno;
1696
error_t ret_errno = 0;
1697
int ret, ret_setflags;
1698
struct ifreq network;
1699
unsigned int if_index = if_nametoindex(interface);
1701
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1705
if(interface_is_up(interface)){
1706
if(not get_flags(interface, &network) and debug){
1708
fprintf_plus(stderr, "Failed to get flags for interface "
1709
"\"%s\"\n", interface);
1712
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1714
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1717
perror_plus("socket");
1723
fprintf_plus(stderr, "Taking down interface \"%s\"\n",
1727
/* Raise priviliges */
1730
ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1733
/* Lower privileges */
1736
/* Close the socket */
1737
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1739
perror_plus("close");
1742
if(ret_setflags == -1){
1744
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
1749
fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",
1757
int main(int argc, char *argv[]){
1758
mandos_context mc = { .server = NULL, .dh_bits = 1024,
1759
.priority = "SECURE256:!CTYPE-X.509:"
1760
"+CTYPE-OPENPGP", .current_server = NULL,
1761
.interfaces = NULL, .interfaces_size = 0 };
1762
AvahiSServiceBrowser *sb = NULL;
1767
int exitcode = EXIT_SUCCESS;
1768
char *interfaces_to_take_down = NULL;
1769
size_t interfaces_to_take_down_size = 0;
1770
char tempdir[] = "/tmp/mandosXXXXXX";
1771
bool tempdir_created = false;
1772
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
1773
const char *seckey = PATHDIR "/" SECKEY;
1774
const char *pubkey = PATHDIR "/" PUBKEY;
1775
char *interfaces_hooks = NULL;
1776
size_t interfaces_hooks_size = 0;
1778
bool gnutls_initialized = false;
1779
bool gpgme_initialized = false;
1781
double retry_interval = 10; /* 10s between trying a server and
1782
retrying the same server again */
1784
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
1785
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
1790
/* Lower any group privileges we might have, just to be safe */
1794
perror_plus("setgid");
1797
/* Lower user privileges (temporarily) */
1801
perror_plus("seteuid");
1809
struct argp_option options[] = {
1810
{ .name = "debug", .key = 128,
1811
.doc = "Debug mode", .group = 3 },
1812
{ .name = "connect", .key = 'c',
1813
.arg = "ADDRESS:PORT",
1814
.doc = "Connect directly to a specific Mandos server",
1816
{ .name = "interface", .key = 'i',
1818
.doc = "Network interface that will be used to search for"
1821
{ .name = "seckey", .key = 's',
1823
.doc = "OpenPGP secret key file base name",
1825
{ .name = "pubkey", .key = 'p',
1827
.doc = "OpenPGP public key file base name",
1829
{ .name = "dh-bits", .key = 129,
1831
.doc = "Bit length of the prime number used in the"
1832
" Diffie-Hellman key exchange",
1834
{ .name = "priority", .key = 130,
1836
.doc = "GnuTLS priority string for the TLS handshake",
1838
{ .name = "delay", .key = 131,
1840
.doc = "Maximum delay to wait for interface startup",
1842
{ .name = "retry", .key = 132,
1844
.doc = "Retry interval used when denied by the Mandos server",
1846
{ .name = "network-hook-dir", .key = 133,
1848
.doc = "Directory where network hooks are located",
1851
* These reproduce what we would get without ARGP_NO_HELP
1853
{ .name = "help", .key = '?',
1854
.doc = "Give this help list", .group = -1 },
1855
{ .name = "usage", .key = -3,
1856
.doc = "Give a short usage message", .group = -1 },
1857
{ .name = "version", .key = 'V',
1858
.doc = "Print program version", .group = -1 },
1862
error_t parse_opt(int key, char *arg,
1863
struct argp_state *state){
1866
case 128: /* --debug */
1869
case 'c': /* --connect */
1872
case 'i': /* --interface */
1873
ret_errno = argz_add_sep(&mc.interfaces, &mc.interfaces_size,
1876
argp_error(state, "%s", strerror(ret_errno));
1879
case 's': /* --seckey */
1882
case 'p': /* --pubkey */
1885
case 129: /* --dh-bits */
1887
tmpmax = strtoimax(arg, &tmp, 10);
1888
if(errno != 0 or tmp == arg or *tmp != '\0'
1889
or tmpmax != (typeof(mc.dh_bits))tmpmax){
1890
argp_error(state, "Bad number of DH bits");
1892
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
1894
case 130: /* --priority */
1897
case 131: /* --delay */
1899
delay = strtof(arg, &tmp);
1900
if(errno != 0 or tmp == arg or *tmp != '\0'){
1901
argp_error(state, "Bad delay");
1903
case 132: /* --retry */
1905
retry_interval = strtod(arg, &tmp);
1906
if(errno != 0 or tmp == arg or *tmp != '\0'
1907
or (retry_interval * 1000) > INT_MAX
1908
or retry_interval < 0){
1909
argp_error(state, "Bad retry interval");
1912
case 133: /* --network-hook-dir */
1916
* These reproduce what we would get without ARGP_NO_HELP
1918
case '?': /* --help */
1919
argp_state_help(state, state->out_stream,
1920
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
1921
& ~(unsigned int)ARGP_HELP_EXIT_OK);
1922
case -3: /* --usage */
1923
argp_state_help(state, state->out_stream,
1924
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
1925
case 'V': /* --version */
1926
fprintf_plus(state->out_stream, "%s\n", argp_program_version);
1927
exit(argp_err_exit_status);
1930
return ARGP_ERR_UNKNOWN;
1935
struct argp argp = { .options = options, .parser = parse_opt,
1937
.doc = "Mandos client -- Get and decrypt"
1938
" passwords from a Mandos server" };
1939
ret = argp_parse(&argp, argc, argv,
1940
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
1947
perror_plus("argp_parse");
1948
exitcode = EX_OSERR;
1951
exitcode = EX_USAGE;
1957
/* Work around Debian bug #633582:
1958
<http://bugs.debian.org/633582> */
1960
/* Re-raise priviliges */
1961
if(raise_privileges() == 0){
1964
if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){
1965
int seckey_fd = open(seckey, O_RDONLY);
1966
if(seckey_fd == -1){
1967
perror_plus("open");
1969
ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));
1971
perror_plus("fstat");
1973
if(S_ISREG(st.st_mode)
1974
and st.st_uid == 0 and st.st_gid == 0){
1975
ret = fchown(seckey_fd, uid, gid);
1977
perror_plus("fchown");
1981
TEMP_FAILURE_RETRY(close(seckey_fd));
1985
if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){
1986
int pubkey_fd = open(pubkey, O_RDONLY);
1987
if(pubkey_fd == -1){
1988
perror_plus("open");
1990
ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));
1992
perror_plus("fstat");
1994
if(S_ISREG(st.st_mode)
1995
and st.st_uid == 0 and st.st_gid == 0){
1996
ret = fchown(pubkey_fd, uid, gid);
1998
perror_plus("fchown");
2002
TEMP_FAILURE_RETRY(close(pubkey_fd));
2006
/* Lower privileges */
2010
perror_plus("seteuid");
2015
/* Remove empty interface names */
2017
char *interface = NULL;
2018
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2020
if(if_nametoindex(interface) == 0){
2021
if(interface[0] != '\0' and strcmp(interface, "none") != 0){
2022
fprintf_plus(stderr, "Not using nonexisting interface"
2023
" \"%s\"\n", interface);
2025
argz_delete(&mc.interfaces, &mc.interfaces_size, interface);
2031
/* Run network hooks */
2034
if(mc.interfaces != NULL){
2035
interfaces_hooks = malloc(mc.interfaces_size);
2036
if(interfaces_hooks == NULL){
2037
perror_plus("malloc");
2040
memcpy(interfaces_hooks, mc.interfaces, mc.interfaces_size);
2041
interfaces_hooks_size = mc.interfaces_size;
2042
argz_stringify(interfaces_hooks, interfaces_hooks_size,
2045
if(not run_network_hooks("start", interfaces_hooks != NULL ?
2046
interfaces_hooks : "", delay)){
2052
avahi_set_log_function(empty_log);
2055
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
2056
from the signal handler */
2057
/* Initialize the pseudo-RNG for Avahi */
2058
srand((unsigned int) time(NULL));
2059
simple_poll = avahi_simple_poll_new();
2060
if(simple_poll == NULL){
2061
fprintf_plus(stderr,
2062
"Avahi: Failed to create simple poll object.\n");
2063
exitcode = EX_UNAVAILABLE;
2067
sigemptyset(&sigterm_action.sa_mask);
2068
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
2070
perror_plus("sigaddset");
2071
exitcode = EX_OSERR;
2074
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
2076
perror_plus("sigaddset");
2077
exitcode = EX_OSERR;
2080
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
2082
perror_plus("sigaddset");
2083
exitcode = EX_OSERR;
2086
/* Need to check if the handler is SIG_IGN before handling:
2087
| [[info:libc:Initial Signal Actions]] |
2088
| [[info:libc:Basic Signal Handling]] |
2090
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
2092
perror_plus("sigaction");
2095
if(old_sigterm_action.sa_handler != SIG_IGN){
2096
ret = sigaction(SIGINT, &sigterm_action, NULL);
2098
perror_plus("sigaction");
2099
exitcode = EX_OSERR;
2103
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
2105
perror_plus("sigaction");
2108
if(old_sigterm_action.sa_handler != SIG_IGN){
2109
ret = sigaction(SIGHUP, &sigterm_action, NULL);
2111
perror_plus("sigaction");
2112
exitcode = EX_OSERR;
2116
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
2118
perror_plus("sigaction");
2121
if(old_sigterm_action.sa_handler != SIG_IGN){
2122
ret = sigaction(SIGTERM, &sigterm_action, NULL);
2124
perror_plus("sigaction");
2125
exitcode = EX_OSERR;
2130
/* If no interfaces were specified, make a list */
2131
if(mc.interfaces == NULL){
2132
struct dirent **direntries;
2133
/* Look for any good interfaces */
2134
ret = scandir(sys_class_net, &direntries, good_interface,
2137
/* Add all found interfaces to interfaces list */
2138
for(int i = 0; i < ret; ++i){
2139
ret_errno = argz_add(&mc.interfaces, &mc.interfaces_size,
2140
direntries[i]->d_name);
2142
perror_plus("argz_add");
2146
fprintf_plus(stderr, "Will use interface \"%s\"\n",
2147
direntries[i]->d_name);
2153
fprintf_plus(stderr, "Could not find a network interface\n");
2154
exitcode = EXIT_FAILURE;
2159
/* If we only got one interface, explicitly use only that one */
2160
if(argz_count(mc.interfaces, mc.interfaces_size) == 1){
2162
fprintf_plus(stderr, "Using only interface \"%s\"\n",
2165
if_index = (AvahiIfIndex)if_nametoindex(mc.interfaces);
2168
/* Bring up interfaces which are down */
2169
if(not (argz_count(mc.interfaces, mc.interfaces_size) == 1
2170
and strcmp(mc.interfaces, "none") == 0)){
2171
char *interface = NULL;
2172
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2174
bool interface_was_up = interface_is_up(interface);
2175
ret = bring_up_interface(interface, delay);
2176
if(not interface_was_up){
2179
perror_plus("Failed to bring up interface");
2181
ret_errno = argz_add(&interfaces_to_take_down,
2182
&interfaces_to_take_down_size,
2187
free(mc.interfaces);
2188
mc.interfaces = NULL;
2189
mc.interfaces_size = 0;
2190
if(debug and (interfaces_to_take_down == NULL)){
2191
fprintf_plus(stderr, "No interfaces were brought up\n");
2199
ret = init_gnutls_global(pubkey, seckey, &mc);
2201
fprintf_plus(stderr, "init_gnutls_global failed\n");
2202
exitcode = EX_UNAVAILABLE;
2205
gnutls_initialized = true;
2212
if(mkdtemp(tempdir) == NULL){
2213
perror_plus("mkdtemp");
2216
tempdir_created = true;
2222
if(not init_gpgme(pubkey, seckey, tempdir, &mc)){
2223
fprintf_plus(stderr, "init_gpgme failed\n");
2224
exitcode = EX_UNAVAILABLE;
2227
gpgme_initialized = true;
2234
if(connect_to != NULL){
2235
/* Connect directly, do not use Zeroconf */
2236
/* (Mainly meant for debugging) */
2237
char *address = strrchr(connect_to, ':');
2239
if(address == NULL){
2240
fprintf_plus(stderr, "No colon in address\n");
2241
exitcode = EX_USAGE;
2251
tmpmax = strtoimax(address+1, &tmp, 10);
2252
if(errno != 0 or tmp == address+1 or *tmp != '\0'
2253
or tmpmax != (in_port_t)tmpmax){
2254
fprintf_plus(stderr, "Bad port number\n");
2255
exitcode = EX_USAGE;
2263
port = (in_port_t)tmpmax;
2265
/* Colon in address indicates IPv6 */
2267
if(strchr(connect_to, ':') != NULL){
2269
/* Accept [] around IPv6 address - see RFC 5952 */
2270
if(connect_to[0] == '[' and address[-1] == ']')
2278
address = connect_to;
2284
while(not quit_now){
2285
ret = start_mandos_communication(address, port, if_index, af,
2287
if(quit_now or ret == 0){
2291
fprintf_plus(stderr, "Retrying in %d seconds\n",
2292
(int)retry_interval);
2294
sleep((int)retry_interval);
2298
exitcode = EXIT_SUCCESS;
2309
AvahiServerConfig config;
2310
/* Do not publish any local Zeroconf records */
2311
avahi_server_config_init(&config);
2312
config.publish_hinfo = 0;
2313
config.publish_addresses = 0;
2314
config.publish_workstation = 0;
2315
config.publish_domain = 0;
2317
/* Allocate a new server */
2318
mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),
2319
&config, NULL, NULL, &ret_errno);
2321
/* Free the Avahi configuration data */
2322
avahi_server_config_free(&config);
2325
/* Check if creating the Avahi server object succeeded */
2326
if(mc.server == NULL){
2327
fprintf_plus(stderr, "Failed to create Avahi server: %s\n",
2328
avahi_strerror(ret_errno));
2329
exitcode = EX_UNAVAILABLE;
2337
/* Create the Avahi service browser */
2338
sb = avahi_s_service_browser_new(mc.server, if_index,
2339
AVAHI_PROTO_UNSPEC, "_mandos._tcp",
2340
NULL, 0, browse_callback,
2343
fprintf_plus(stderr, "Failed to create service browser: %s\n",
2344
avahi_strerror(avahi_server_errno(mc.server)));
2345
exitcode = EX_UNAVAILABLE;
2353
/* Run the main loop */
2356
fprintf_plus(stderr, "Starting Avahi loop search\n");
2359
ret = avahi_loop_with_timeout(simple_poll,
2360
(int)(retry_interval * 1000), &mc);
2362
fprintf_plus(stderr, "avahi_loop_with_timeout exited %s\n",
2363
(ret == 0) ? "successfully" : "with error");
2369
fprintf_plus(stderr, "%s exiting\n", argv[0]);
2372
/* Cleanup things */
2374
avahi_s_service_browser_free(sb);
2376
if(mc.server != NULL)
2377
avahi_server_free(mc.server);
2379
if(simple_poll != NULL)
2380
avahi_simple_poll_free(simple_poll);
2382
if(gnutls_initialized){
2383
gnutls_certificate_free_credentials(mc.cred);
2384
gnutls_global_deinit();
2385
gnutls_dh_params_deinit(mc.dh_params);
2388
if(gpgme_initialized){
2389
gpgme_release(mc.ctx);
2392
/* Cleans up the circular linked list of Mandos servers the client
2394
if(mc.current_server != NULL){
2395
mc.current_server->prev->next = NULL;
2396
while(mc.current_server != NULL){
2397
server *next = mc.current_server->next;
2398
free(mc.current_server);
2399
mc.current_server = next;
2403
/* Re-raise priviliges */
2407
/* Run network hooks */
2408
run_network_hooks("stop", interfaces_hooks != NULL ?
2409
interfaces_hooks : "", delay);
2411
/* Take down the network interfaces which were brought up */
2413
char *interface = NULL;
2414
while((interface=argz_next(interfaces_to_take_down,
2415
interfaces_to_take_down_size,
2417
ret_errno = take_down_interface(interface);
2420
perror_plus("Failed to take down interface");
2423
if(debug and (interfaces_to_take_down == NULL)){
2424
fprintf_plus(stderr, "No interfaces needed to be taken"
2429
lower_privileges_permanently();
2432
free(interfaces_to_take_down);
2433
free(interfaces_hooks);
2435
/* Removes the GPGME temp directory and all files inside */
2436
if(tempdir_created){
2437
struct dirent **direntries = NULL;
2438
struct dirent *direntry = NULL;
2439
int numentries = scandir(tempdir, &direntries, notdotentries,
2441
if (numentries > 0){
2442
for(int i = 0; i < numentries; i++){
2443
direntry = direntries[i];
2444
char *fullname = NULL;
2445
ret = asprintf(&fullname, "%s/%s", tempdir,
2448
perror_plus("asprintf");
2451
ret = remove(fullname);
2453
fprintf_plus(stderr, "remove(\"%s\"): %s\n", fullname,
2460
/* need to clean even if 0 because man page doesn't specify */
2462
if (numentries == -1){
2463
perror_plus("scandir");
2465
ret = rmdir(tempdir);
2466
if(ret == -1 and errno != ENOENT){
2467
perror_plus("rmdir");
2472
sigemptyset(&old_sigterm_action.sa_mask);
2473
old_sigterm_action.sa_handler = SIG_DFL;
2474
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
2475
&old_sigterm_action,
2478
perror_plus("sigaction");
2481
ret = raise(signal_received);
2482
} while(ret != 0 and errno == EINTR);
2484
perror_plus("raise");
2487
TEMP_FAILURE_RETRY(pause());
1137
ret = rmdir(tempdir);
1138
if(ret == -1 and errno != ENOENT){