1019
1117
signal_received = sig;
1020
1118
int old_errno = errno;
1119
/* set main loop to exit */
1021
1120
if(mc.simple_poll != NULL){
1022
1121
avahi_simple_poll_quit(mc.simple_poll);
1024
1123
errno = old_errno;
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);
1028
1193
* This function determines if a directory entry in /sys/class/net
1029
1194
* corresponds to an acceptable network device.
1030
1195
* (This function is passed to scandir(3) as a filter function.)
1032
1197
int good_interface(const struct dirent *if_entry){
1034
char *flagname = NULL;
1035
int ret = asprintf(&flagname, "%s/%s/flags", sys_class_net,
1041
1198
if(if_entry->d_name[0] == '.'){
1044
int flags_fd = (int)TEMP_FAILURE_RETRY(open(flagname, O_RDONLY));
1049
typedef short ifreq_flags; /* ifreq.ifr_flags in netdevice(7) */
1050
/* read line from flags_fd */
1051
ssize_t to_read = (sizeof(ifreq_flags)*2)+3; /* "0x1003\n" */
1052
char *flagstring = malloc((size_t)to_read+1); /* +1 for final \0 */
1053
flagstring[(size_t)to_read] = '\0';
1054
if(flagstring == NULL){
1060
ssret = (ssize_t)TEMP_FAILURE_RETRY(read(flags_fd, flagstring,
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);
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);
1375
perror_plus("clock_gettime");
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
if(errno == ENOENT){
1455
fprintf_plus(stderr, "Network hook directory \"%s\" not"
1456
" found\n", hookdir);
1459
perror_plus("scandir");
1462
int devnull = open("/dev/null", O_RDONLY);
1463
for(int i = 0; i < numhooks; i++){
1464
direntry = direntries[i];
1465
char *fullname = NULL;
1466
ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);
1468
perror_plus("asprintf");
1472
fprintf_plus(stderr, "Running network hook \"%s\"\n",
1475
pid_t hook_pid = fork();
1478
/* Raise privileges */
1479
raise_privileges_permanently();
1484
perror_plus("setgid");
1486
/* Reset supplementary groups */
1488
ret = setgroups(0, NULL);
1490
perror_plus("setgroups");
1492
dup2(devnull, STDIN_FILENO);
1494
dup2(STDERR_FILENO, STDOUT_FILENO);
1495
ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);
1497
perror_plus("setenv");
1500
ret = setenv("DEVICE", interface, 1);
1502
perror_plus("setenv");
1505
ret = setenv("VERBOSITY", debug ? "1" : "0", 1);
1507
perror_plus("setenv");
1510
ret = setenv("MODE", mode, 1);
1512
perror_plus("setenv");
1516
ret = asprintf(&delaystring, "%f", delay);
1518
perror_plus("asprintf");
1521
ret = setenv("DELAY", delaystring, 1);
1524
perror_plus("setenv");
1528
if(connect_to != NULL){
1529
ret = setenv("CONNECT", connect_to, 1);
1531
perror_plus("setenv");
1535
if(execl(fullname, direntry->d_name, mode, NULL) == -1){
1536
perror_plus("execl");
1537
_exit(EXIT_FAILURE);
1541
if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){
1542
perror_plus("waitpid");
1546
if(WIFEXITED(status)){
1547
if(WEXITSTATUS(status) != 0){
1548
fprintf_plus(stderr, "Warning: network hook \"%s\" exited"
1549
" with status %d\n", direntry->d_name,
1550
WEXITSTATUS(status));
1554
} else if(WIFSIGNALED(status)){
1555
fprintf_plus(stderr, "Warning: network hook \"%s\" died by"
1556
" signal %d\n", direntry->d_name,
1561
fprintf_plus(stderr, "Warning: network hook \"%s\""
1562
" crashed\n", direntry->d_name);
1569
fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",
1578
error_t bring_up_interface(const char *const interface,
1581
error_t old_errno = errno;
1582
error_t ret_errno = 0;
1583
int ret, ret_setflags;
1584
struct ifreq network;
1585
unsigned int if_index = if_nametoindex(interface);
1587
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1597
if(not interface_is_up(interface)){
1598
if(not get_flags(interface, &network) and debug){
1600
fprintf_plus(stderr, "Failed to get flags for interface "
1601
"\"%s\"\n", interface);
1604
network.ifr_flags |= IFF_UP;
1606
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1609
perror_plus("socket");
1621
fprintf_plus(stderr, "Bringing up interface \"%s\"\n",
1625
/* Raise priviliges */
1629
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1630
messages about the network interface to mess up the prompt */
1631
int ret_linux = klogctl(8, NULL, 5);
1632
bool restore_loglevel = true;
1633
if(ret_linux == -1){
1634
restore_loglevel = false;
1635
perror_plus("klogctl");
1637
#endif /* __linux__ */
1638
ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1641
if(restore_loglevel){
1642
ret_linux = klogctl(7, NULL, 0);
1643
if(ret_linux == -1){
1644
perror_plus("klogctl");
1647
#endif /* __linux__ */
1649
/* Lower privileges */
1652
/* Close the socket */
1653
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1655
perror_plus("close");
1658
if(ret_setflags == -1){
1660
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1665
fprintf_plus(stderr, "Interface \"%s\" is already up; good\n",
1669
/* Sleep checking until interface is running.
1670
Check every 0.25s, up to total time of delay */
1671
for(int i=0; i < delay * 4; i++){
1672
if(interface_is_running(interface)){
1077
tmpmax = strtoimax(flagstring, &tmp, 0);
1078
if(errno != 0 or tmp == flagstring or (*tmp != '\0'
1079
and not (isspace(*tmp)))
1080
or tmpmax != (ifreq_flags)tmpmax){
1082
fprintf(stderr, "Invalid flags \"%s\" for interface \"%s\"\n",
1083
flagstring, if_entry->d_name);
1089
ifreq_flags flags = (ifreq_flags)tmpmax;
1090
/* Reject the loopback device */
1091
if(flags & IFF_LOOPBACK){
1093
fprintf(stderr, "Rejecting loopback interface \"%s\"\n",
1098
/* Accept point-to-point devices only if connect_to is specified */
1099
if(connect_to != NULL and (flags & IFF_POINTOPOINT)){
1101
fprintf(stderr, "Accepting point-to-point interface \"%s\"\n",
1106
/* Otherwise, reject non-broadcast-capable devices */
1107
if(not (flags & IFF_BROADCAST)){
1109
fprintf(stderr, "Rejecting non-broadcast interface \"%s\"\n",
1114
/* Accept this device */
1116
fprintf(stderr, "Interface \"%s\" is acceptable\n",
1675
struct timespec sleeptime = { .tv_nsec = 250000000 };
1676
ret = nanosleep(&sleeptime, NULL);
1677
if(ret == -1 and errno != EINTR){
1678
perror_plus("nanosleep");
1686
error_t take_down_interface(const char *const interface){
1688
error_t old_errno = errno;
1689
error_t ret_errno = 0;
1690
int ret, ret_setflags;
1691
struct ifreq network;
1692
unsigned int if_index = if_nametoindex(interface);
1694
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1698
if(interface_is_up(interface)){
1699
if(not get_flags(interface, &network) and debug){
1701
fprintf_plus(stderr, "Failed to get flags for interface "
1702
"\"%s\"\n", interface);
1705
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1707
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1710
perror_plus("socket");
1716
fprintf_plus(stderr, "Taking down interface \"%s\"\n",
1720
/* Raise priviliges */
1723
ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1726
/* Lower privileges */
1729
/* Close the socket */
1730
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1732
perror_plus("close");
1735
if(ret_setflags == -1){
1737
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
1742
fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",
1122
1750
int main(int argc, char *argv[]){
1123
1751
AvahiSServiceBrowser *sb = NULL;
1126
1754
intmax_t tmpmax;
1128
1756
int exitcode = EXIT_SUCCESS;
1129
const char *interface = "";
1130
struct ifreq network;
1132
bool take_down_interface = false;
1757
char *interfaces = NULL;
1758
size_t interfaces_size = 0;
1759
char *interfaces_to_take_down = NULL;
1760
size_t interfaces_to_take_down_size = 0;
1135
1761
char tempdir[] = "/tmp/mandosXXXXXX";
1136
1762
bool tempdir_created = false;
1137
1763
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
1138
1764
const char *seckey = PATHDIR "/" SECKEY;
1139
1765
const char *pubkey = PATHDIR "/" PUBKEY;
1766
char *interfaces_hooks = NULL;
1767
size_t interfaces_hooks_size = 0;
1141
1769
bool gnutls_initialized = false;
1142
1770
bool gpgme_initialized = false;
1143
1771
float delay = 2.5f;
1772
double retry_interval = 10; /* 10s between trying a server and
1773
retrying the same server again */
1145
1775
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
1146
1776
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
1357
2081
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1359
perror("sigaction");
2083
perror_plus("sigaction");
1360
2084
return EX_OSERR;
1362
2086
if(old_sigterm_action.sa_handler != SIG_IGN){
1363
2087
ret = sigaction(SIGINT, &sigterm_action, NULL);
1365
perror("sigaction");
2089
perror_plus("sigaction");
1366
2090
exitcode = EX_OSERR;
1370
2094
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1372
perror("sigaction");
2096
perror_plus("sigaction");
1373
2097
return EX_OSERR;
1375
2099
if(old_sigterm_action.sa_handler != SIG_IGN){
1376
2100
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1378
perror("sigaction");
2102
perror_plus("sigaction");
1379
2103
exitcode = EX_OSERR;
1383
2107
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1385
perror("sigaction");
2109
perror_plus("sigaction");
1386
2110
return EX_OSERR;
1388
2112
if(old_sigterm_action.sa_handler != SIG_IGN){
1389
2113
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1391
perror("sigaction");
2115
perror_plus("sigaction");
1392
2116
exitcode = EX_OSERR;
1397
/* If the interface is down, bring it up */
1398
if(strcmp(interface, "none") != 0){
1399
if_index = (AvahiIfIndex) if_nametoindex(interface);
1401
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1402
exitcode = EX_UNAVAILABLE;
1410
/* Re-raise priviliges */
1418
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1419
messages about the network interface to mess up the prompt */
1420
ret = klogctl(8, NULL, 5);
1421
bool restore_loglevel = true;
1423
restore_loglevel = false;
1426
#endif /* __linux__ */
1428
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1431
exitcode = EX_OSERR;
1433
if(restore_loglevel){
1434
ret = klogctl(7, NULL, 0);
1439
#endif /* __linux__ */
1440
/* Lower privileges */
1448
strcpy(network.ifr_name, interface);
1449
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1451
perror("ioctl SIOCGIFFLAGS");
1453
if(restore_loglevel){
1454
ret = klogctl(7, NULL, 0);
1459
#endif /* __linux__ */
1460
exitcode = EX_OSERR;
1461
/* Lower privileges */
1469
if((network.ifr_flags & IFF_UP) == 0){
1470
network.ifr_flags |= IFF_UP;
1471
take_down_interface = true;
1472
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1474
take_down_interface = false;
1475
perror("ioctl SIOCSIFFLAGS +IFF_UP");
1476
exitcode = EX_OSERR;
1478
if(restore_loglevel){
1479
ret = klogctl(7, NULL, 0);
1484
#endif /* __linux__ */
1485
/* Lower privileges */
1494
/* sleep checking until interface is running */
1495
for(int i=0; i < delay * 4; i++){
1496
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1498
perror("ioctl SIOCGIFFLAGS");
1499
} else if(network.ifr_flags & IFF_RUNNING){
1502
struct timespec sleeptime = { .tv_nsec = 250000000 };
1503
ret = nanosleep(&sleeptime, NULL);
1504
if(ret == -1 and errno != EINTR){
1505
perror("nanosleep");
1508
if(not take_down_interface){
1509
/* We won't need the socket anymore */
1510
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1516
if(restore_loglevel){
1517
/* Restores kernel loglevel to default */
1518
ret = klogctl(7, NULL, 0);
1523
#endif /* __linux__ */
1524
/* Lower privileges */
1526
if(take_down_interface){
1527
/* Lower privileges */
2121
/* If no interfaces were specified, make a list */
2122
if(interfaces == NULL){
2123
struct dirent **direntries;
2124
/* Look for any good interfaces */
2125
ret = scandir(sys_class_net, &direntries, good_interface,
2128
/* Add all found interfaces to interfaces list */
2129
for(int i = 0; i < ret; ++i){
2130
ret_errno = argz_add(&interfaces, &interfaces_size,
2131
direntries[i]->d_name);
2133
perror_plus("argz_add");
2137
fprintf_plus(stderr, "Will use interface \"%s\"\n",
2138
direntries[i]->d_name);
1533
/* Lower privileges permanently */
2144
fprintf_plus(stderr, "Could not find a network interface\n");
2145
exitcode = EXIT_FAILURE;
2150
/* If we only got one interface, explicitly use only that one */
2151
if(argz_count(interfaces, interfaces_size) == 1){
2153
fprintf_plus(stderr, "Using only interface \"%s\"\n",
2156
if_index = (AvahiIfIndex)if_nametoindex(interfaces);
2159
/* Bring up interfaces which are down */
2160
if(not (argz_count(interfaces, interfaces_size) == 1
2161
and strcmp(interfaces, "none") == 0)){
2162
char *interface = NULL;
2163
while((interface = argz_next(interfaces, interfaces_size,
2165
bool interface_was_up = interface_is_up(interface);
2166
ret = bring_up_interface(interface, delay);
2167
if(not interface_was_up){
2170
perror_plus("Failed to bring up interface");
2172
ret_errno = argz_add(&interfaces_to_take_down,
2173
&interfaces_to_take_down_size,
2180
interfaces_size = 0;
2181
if(debug and (interfaces_to_take_down == NULL)){
2182
fprintf_plus(stderr, "No interfaces were brought up\n");