72
71
INET_ADDRSTRLEN, INET6_ADDRSTRLEN
74
73
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
75
getuid(), getgid(), seteuid(),
77
#include <arpa/inet.h> /* inet_pton(), htons, inet_ntop() */
74
getuid(), getgid(), setuid(),
76
#include <arpa/inet.h> /* inet_pton(), htons */
78
77
#include <iso646.h> /* not, or, and */
79
78
#include <argp.h> /* struct argp_option, error_t, struct
80
79
argp_state, struct argp,
81
80
argp_parse(), ARGP_KEY_ARG,
82
81
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
83
82
#include <signal.h> /* sigemptyset(), sigaddset(),
84
sigaction(), SIGTERM, sig_atomic_t,
86
#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,
87
EX_NOHOST, EX_IOERR, EX_PROTOCOL */
83
sigaction(), SIGTERM, sigaction,
90
87
#include <sys/klog.h> /* klogctl() */
187
159
return buffer_capacity;
190
/* Add server to set of servers to retry periodically */
191
int add_server(const char *ip, uint16_t port,
192
AvahiIfIndex if_index,
195
server *new_server = malloc(sizeof(server));
196
if(new_server == NULL){
197
perror_plus("malloc");
200
*new_server = (server){ .ip = strdup(ip),
202
.if_index = if_index,
204
if(new_server->ip == NULL){
205
perror_plus("strdup");
208
/* Special case of first server */
209
if (mc.current_server == NULL){
210
new_server->next = new_server;
211
new_server->prev = new_server;
212
mc.current_server = new_server;
213
/* Place the new server last in the list */
215
new_server->next = mc.current_server;
216
new_server->prev = mc.current_server->prev;
217
new_server->prev->next = new_server;
218
mc.current_server->prev = new_server;
220
ret = clock_gettime(CLOCK_MONOTONIC, &mc.current_server->last_seen);
222
perror_plus("clock_gettime");
229
163
* Initialize GPGME.
231
165
static bool init_gpgme(const char *seckey,
232
166
const char *pubkey, const char *tempdir){
233
168
gpgme_error_t rc;
234
169
gpgme_engine_info_t engine_info;
1073
/* Signal handler that stops main loop after SIGTERM */
1074
static void handle_sigterm(int sig){
878
sig_atomic_t quit_now = 0;
880
/* stop main loop after sigterm has been called */
881
static void handle_sigterm(__attribute__((unused)) int sig){
1079
signal_received = sig;
1080
886
int old_errno = errno;
1081
/* set main loop to exit */
1082
887
if(mc.simple_poll != NULL){
1083
888
avahi_simple_poll_quit(mc.simple_poll);
1085
890
errno = old_errno;
1089
* This function determines if a directory entry in /sys/class/net
1090
* corresponds to an acceptable network device.
1091
* (This function is passed to scandir(3) as a filter function.)
1093
int good_interface(const struct dirent *if_entry){
1095
char *flagname = NULL;
1096
if(if_entry->d_name[0] == '.'){
1099
int ret = asprintf(&flagname, "%s/%s/flags", sys_class_net,
1102
perror_plus("asprintf");
1105
int flags_fd = (int)TEMP_FAILURE_RETRY(open(flagname, O_RDONLY));
1107
perror_plus("open");
1112
typedef short ifreq_flags; /* ifreq.ifr_flags in netdevice(7) */
1113
/* read line from flags_fd */
1114
ssize_t to_read = 2+(sizeof(ifreq_flags)*2)+1; /* "0x1003\n" */
1115
char *flagstring = malloc((size_t)to_read+1); /* +1 for final \0 */
1116
flagstring[(size_t)to_read] = '\0';
1117
if(flagstring == NULL){
1118
perror_plus("malloc");
1123
ssret = (ssize_t)TEMP_FAILURE_RETRY(read(flags_fd, flagstring,
1126
perror_plus("read");
1140
tmpmax = strtoimax(flagstring, &tmp, 0);
1141
if(errno != 0 or tmp == flagstring or (*tmp != '\0'
1142
and not (isspace(*tmp)))
1143
or tmpmax != (ifreq_flags)tmpmax){
1145
fprintf(stderr, "Invalid flags \"%s\" for interface \"%s\"\n",
1146
flagstring, if_entry->d_name);
1152
ifreq_flags flags = (ifreq_flags)tmpmax;
1153
/* Reject the loopback device */
1154
if(flags & IFF_LOOPBACK){
1156
fprintf(stderr, "Rejecting loopback interface \"%s\"\n",
1161
/* Accept point-to-point devices only if connect_to is specified */
1162
if(connect_to != NULL and (flags & IFF_POINTOPOINT)){
1164
fprintf(stderr, "Accepting point-to-point interface \"%s\"\n",
1169
/* Otherwise, reject non-broadcast-capable devices */
1170
if(not (flags & IFF_BROADCAST)){
1172
fprintf(stderr, "Rejecting non-broadcast interface \"%s\"\n",
1177
/* Reject non-ARP interfaces (including dummy interfaces) */
1178
if(flags & IFF_NOARP){
1180
fprintf(stderr, "Rejecting non-ARP interface \"%s\"\n",
1185
/* Accept this device */
1187
fprintf(stderr, "Interface \"%s\" is acceptable\n",
1193
int notdotentries(const struct dirent *direntry){
1194
/* Skip "." and ".." */
1195
if(direntry->d_name[0] == '.'
1196
and (direntry->d_name[1] == '\0'
1197
or (direntry->d_name[1] == '.'
1198
and direntry->d_name[2] == '\0'))){
1204
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){
1206
struct timespec now;
1207
struct timespec waited_time;
1208
intmax_t block_time;
1211
if(mc.current_server == NULL){
1214
"Wait until first server is found. No timeout!\n");
1216
ret = avahi_simple_poll_iterate(s, -1);
1219
fprintf(stderr, "Check current_server if we should run it,"
1222
/* the current time */
1223
ret = clock_gettime(CLOCK_MONOTONIC, &now);
1225
perror_plus("clock_gettime");
1228
/* Calculating in ms how long time between now and server
1229
who we visted longest time ago. Now - last seen. */
1230
waited_time.tv_sec = (now.tv_sec
1231
- mc.current_server->last_seen.tv_sec);
1232
waited_time.tv_nsec = (now.tv_nsec
1233
- mc.current_server->last_seen.tv_nsec);
1234
/* total time is 10s/10,000ms.
1235
Converting to s from ms by dividing by 1,000,
1236
and ns to ms by dividing by 1,000,000. */
1237
block_time = ((retry_interval
1238
- ((intmax_t)waited_time.tv_sec * 1000))
1239
- ((intmax_t)waited_time.tv_nsec / 1000000));
1242
fprintf(stderr, "Blocking for %" PRIdMAX " ms\n", block_time);
1245
if(block_time <= 0){
1246
ret = start_mandos_communication(mc.current_server->ip,
1247
mc.current_server->port,
1248
mc.current_server->if_index,
1249
mc.current_server->af);
1251
avahi_simple_poll_quit(mc.simple_poll);
1254
ret = clock_gettime(CLOCK_MONOTONIC,
1255
&mc.current_server->last_seen);
1257
perror_plus("clock_gettime");
1260
mc.current_server = mc.current_server->next;
1261
block_time = 0; /* Call avahi to find new Mandos
1262
servers, but don't block */
1265
ret = avahi_simple_poll_iterate(s, (int)block_time);
1268
if (ret > 0 or errno != EINTR) {
1269
return (ret != 1) ? ret : 0;
1275
893
int main(int argc, char *argv[]){
1276
894
AvahiSServiceBrowser *sb = NULL;
1355
950
.arg = "SECONDS",
1356
951
.doc = "Maximum delay to wait for interface startup",
1358
{ .name = "retry", .key = 132,
1360
.doc = "Retry interval used when denied by the mandos server",
1363
* These reproduce what we would get without ARGP_NO_HELP
1365
{ .name = "help", .key = '?',
1366
.doc = "Give this help list", .group = -1 },
1367
{ .name = "usage", .key = -3,
1368
.doc = "Give a short usage message", .group = -1 },
1369
{ .name = "version", .key = 'V',
1370
.doc = "Print program version", .group = -1 },
1371
953
{ .name = NULL }
1374
956
error_t parse_opt(int key, char *arg,
1375
957
struct argp_state *state){
1378
959
case 128: /* --debug */
1407
989
delay = strtof(arg, &tmp);
1408
990
if(errno != 0 or tmp == arg or *tmp != '\0'){
1409
argp_error(state, "Bad delay");
1411
case 132: /* --retry */
1413
retry_interval = strtod(arg, &tmp);
1414
if(errno != 0 or tmp == arg or *tmp != '\0'
1415
or (retry_interval * 1000) > INT_MAX
1416
or retry_interval < 0){
1417
argp_error(state, "Bad retry interval");
991
fprintf(stderr, "Bad delay\n");
1421
* These reproduce what we would get without ARGP_NO_HELP
1423
case '?': /* --help */
1424
argp_state_help(state, state->out_stream,
1425
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
1426
& ~(unsigned int)ARGP_HELP_EXIT_OK);
1427
case -3: /* --usage */
1428
argp_state_help(state, state->out_stream,
1429
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
1430
case 'V': /* --version */
1431
fprintf(state->out_stream, "%s\n", argp_program_version);
1432
exit(argp_err_exit_status);
1435
1000
return ARGP_ERR_UNKNOWN;
1440
1005
struct argp argp = { .options = options, .parser = parse_opt,
1441
1006
.args_doc = "",
1442
1007
.doc = "Mandos client -- Get and decrypt"
1443
1008
" passwords from a Mandos server" };
1444
ret = argp_parse(&argp, argc, argv,
1445
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
1452
perror_plus("argp_parse");
1453
exitcode = EX_OSERR;
1456
exitcode = EX_USAGE;
1462
/* Work around Debian bug #633582:
1463
<http://bugs.debian.org/633582> */
1466
/* Re-raise priviliges */
1470
perror_plus("seteuid");
1473
if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){
1474
int seckey_fd = open(seckey, O_RDONLY);
1475
if(seckey_fd == -1){
1476
perror_plus("open");
1478
ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));
1480
perror_plus("fstat");
1482
if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){
1483
ret = fchown(seckey_fd, uid, gid);
1485
perror_plus("fchown");
1489
TEMP_FAILURE_RETRY(close(seckey_fd));
1493
if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){
1494
int pubkey_fd = open(pubkey, O_RDONLY);
1495
if(pubkey_fd == -1){
1496
perror_plus("open");
1498
ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));
1500
perror_plus("fstat");
1502
if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){
1503
ret = fchown(pubkey_fd, uid, gid);
1505
perror_plus("fchown");
1509
TEMP_FAILURE_RETRY(close(pubkey_fd));
1513
/* Lower privileges */
1517
perror_plus("seteuid");
1009
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
1010
if(ret == ARGP_ERR_UNKNOWN){
1011
fprintf(stderr, "Unknown error while parsing arguments\n");
1012
exitcode = EXIT_FAILURE;
1522
1018
avahi_set_log_function(empty_log);
1525
if(interface[0] == '\0'){
1526
struct dirent **direntries;
1527
ret = scandir(sys_class_net, &direntries, good_interface,
1530
/* Pick the first good interface */
1531
interface = strdup(direntries[0]->d_name);
1533
fprintf(stderr, "Using interface \"%s\"\n", interface);
1535
if(interface == NULL){
1536
perror_plus("malloc");
1538
exitcode = EXIT_FAILURE;
1544
fprintf(stderr, "Could not find a network interface\n");
1545
exitcode = EXIT_FAILURE;
1550
1021
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
1551
1022
from the signal handler */
1554
1025
mc.simple_poll = avahi_simple_poll_new();
1555
1026
if(mc.simple_poll == NULL){
1556
1027
fprintf(stderr, "Avahi: Failed to create simple poll object.\n");
1557
exitcode = EX_UNAVAILABLE;
1028
exitcode = EXIT_FAILURE;
1561
1032
sigemptyset(&sigterm_action.sa_mask);
1562
1033
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1564
perror_plus("sigaddset");
1565
exitcode = EX_OSERR;
1035
perror("sigaddset");
1036
exitcode = EXIT_FAILURE;
1568
1039
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1570
perror_plus("sigaddset");
1571
exitcode = EX_OSERR;
1041
perror("sigaddset");
1042
exitcode = EXIT_FAILURE;
1574
1045
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1576
perror_plus("sigaddset");
1577
exitcode = EX_OSERR;
1580
/* Need to check if the handler is SIG_IGN before handling:
1581
| [[info:libc:Initial Signal Actions]] |
1582
| [[info:libc:Basic Signal Handling]] |
1584
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1586
perror_plus("sigaction");
1589
if(old_sigterm_action.sa_handler != SIG_IGN){
1590
ret = sigaction(SIGINT, &sigterm_action, NULL);
1592
perror_plus("sigaction");
1593
exitcode = EX_OSERR;
1597
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1599
perror_plus("sigaction");
1602
if(old_sigterm_action.sa_handler != SIG_IGN){
1603
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1605
perror_plus("sigaction");
1606
exitcode = EX_OSERR;
1610
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1612
perror_plus("sigaction");
1615
if(old_sigterm_action.sa_handler != SIG_IGN){
1616
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1618
perror_plus("sigaction");
1619
exitcode = EX_OSERR;
1047
perror("sigaddset");
1048
exitcode = EXIT_FAILURE;
1051
ret = sigaction(SIGTERM, &sigterm_action, &old_sigterm_action);
1053
perror("sigaction");
1054
exitcode = EXIT_FAILURE;
1624
1058
/* If the interface is down, bring it up */
1625
if(strcmp(interface, "none") != 0){
1626
if_index = (AvahiIfIndex) if_nametoindex(interface);
1628
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1629
exitcode = EX_UNAVAILABLE;
1637
/* Re-raise priviliges */
1641
perror_plus("seteuid");
1059
if(interface[0] != '\0'){
1644
1060
#ifdef __linux__
1645
1061
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1646
messages about the network interface to mess up the prompt */
1062
messages to mess up the prompt */
1647
1063
ret = klogctl(8, NULL, 5);
1648
1064
bool restore_loglevel = true;
1650
1066
restore_loglevel = false;
1651
perror_plus("klogctl");
1653
1069
#endif /* __linux__ */
1655
1071
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1657
perror_plus("socket");
1658
exitcode = EX_OSERR;
1074
exitcode = EXIT_FAILURE;
1659
1075
#ifdef __linux__
1660
1076
if(restore_loglevel){
1661
1077
ret = klogctl(7, NULL, 0);
1663
perror_plus("klogctl");
1666
1082
#endif /* __linux__ */
1667
/* Lower privileges */
1671
perror_plus("seteuid");
1675
1085
strcpy(network.ifr_name, interface);
1676
1086
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1678
perror_plus("ioctl SIOCGIFFLAGS");
1088
perror("ioctl SIOCGIFFLAGS");
1679
1089
#ifdef __linux__
1680
1090
if(restore_loglevel){
1681
1091
ret = klogctl(7, NULL, 0);
1683
perror_plus("klogctl");
1686
1096
#endif /* __linux__ */
1687
exitcode = EX_OSERR;
1688
/* Lower privileges */
1692
perror_plus("seteuid");
1097
exitcode = EXIT_FAILURE;
1696
1100
if((network.ifr_flags & IFF_UP) == 0){
1697
1101
network.ifr_flags |= IFF_UP;
1698
take_down_interface = true;
1699
1102
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1701
take_down_interface = false;
1702
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1703
exitcode = EX_OSERR;
1104
perror("ioctl SIOCSIFFLAGS");
1105
exitcode = EXIT_FAILURE;
1704
1106
#ifdef __linux__
1705
1107
if(restore_loglevel){
1706
1108
ret = klogctl(7, NULL, 0);
1708
perror_plus("klogctl");
1711
1113
#endif /* __linux__ */
1712
/* Lower privileges */
1716
perror_plus("seteuid");
1721
/* Sleep checking until interface is running.
1722
Check every 0.25s, up to total time of delay */
1117
/* sleep checking until interface is running */
1723
1118
for(int i=0; i < delay * 4; i++){
1724
1119
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1726
perror_plus("ioctl SIOCGIFFLAGS");
1121
perror("ioctl SIOCGIFFLAGS");
1727
1122
} else if(network.ifr_flags & IFF_RUNNING){
1730
1125
struct timespec sleeptime = { .tv_nsec = 250000000 };
1731
1126
ret = nanosleep(&sleeptime, NULL);
1732
1127
if(ret == -1 and errno != EINTR){
1733
perror_plus("nanosleep");
1128
perror("nanosleep");
1736
if(not take_down_interface){
1737
/* We won't need the socket anymore */
1738
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1740
perror_plus("close");
1131
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1743
1135
#ifdef __linux__
1744
1136
if(restore_loglevel){
1745
1137
/* Restores kernel loglevel to default */
1746
1138
ret = klogctl(7, NULL, 0);
1748
perror_plus("klogctl");
1751
1143
#endif /* __linux__ */
1752
/* Lower privileges */
1754
if(take_down_interface){
1755
/* Lower privileges */
1758
perror_plus("seteuid");
1761
/* Lower privileges permanently */
1764
perror_plus("setuid");
1773
1160
ret = init_gnutls_global(pubkey, seckey);
1775
1162
fprintf(stderr, "init_gnutls_global failed\n");
1776
exitcode = EX_UNAVAILABLE;
1163
exitcode = EXIT_FAILURE;
1779
1166
gnutls_initialized = true;
1786
1169
if(mkdtemp(tempdir) == NULL){
1787
perror_plus("mkdtemp");
1790
1173
tempdir_created = true;
1796
1175
if(not init_gpgme(pubkey, seckey, tempdir)){
1797
1176
fprintf(stderr, "init_gpgme failed\n");
1798
exitcode = EX_UNAVAILABLE;
1177
exitcode = EXIT_FAILURE;
1801
1180
gpgme_initialized = true;
1183
if(interface[0] != '\0'){
1184
if_index = (AvahiIfIndex) if_nametoindex(interface);
1186
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1187
exitcode = EXIT_FAILURE;
1808
1192
if(connect_to != NULL){
1811
1195
char *address = strrchr(connect_to, ':');
1812
1196
if(address == NULL){
1813
1197
fprintf(stderr, "No colon in address\n");
1814
exitcode = EX_USAGE;
1198
exitcode = EXIT_FAILURE;
1824
1203
tmpmax = strtoimax(address+1, &tmp, 10);
1825
1204
if(errno != 0 or tmp == address+1 or *tmp != '\0'
1826
1205
or tmpmax != (uint16_t)tmpmax){
1827
1206
fprintf(stderr, "Bad port number\n");
1828
exitcode = EX_USAGE;
1207
exitcode = EXIT_FAILURE;
1836
1210
port = (uint16_t)tmpmax;
1837
1211
*address = '\0';
1212
address = connect_to;
1838
1213
/* Colon in address indicates IPv6 */
1840
if(strchr(connect_to, ':') != NULL){
1215
if(strchr(address, ':') != NULL){
1842
/* Accept [] around IPv6 address - see RFC 5952 */
1843
if(connect_to[0] == '[' and address[-1] == ']')
1851
address = connect_to;
1857
while(not quit_now){
1858
ret = start_mandos_communication(address, port, if_index, af);
1859
if(quit_now or ret == 0){
1863
fprintf(stderr, "Retrying in %d seconds\n",
1864
(int)retry_interval);
1866
sleep((int)retry_interval);
1220
ret = start_mandos_communication(address, port, if_index, af);
1222
exitcode = EXIT_FAILURE;
1870
1224
exitcode = EXIT_SUCCESS;
1881
1230
AvahiServerConfig config;
1882
1231
/* Do not publish any local Zeroconf records */
1960
1296
if(gpgme_initialized){
1961
1297
gpgme_release(mc.ctx);
1964
/* Cleans up the circular linked list of Mandos servers the client
1966
if(mc.current_server != NULL){
1967
mc.current_server->prev->next = NULL;
1968
while(mc.current_server != NULL){
1969
server *next = mc.current_server->next;
1970
free(mc.current_server);
1971
mc.current_server = next;
1975
/* Take down the network interface */
1976
if(take_down_interface){
1977
/* Re-raise priviliges */
1981
perror_plus("seteuid");
1984
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1986
perror_plus("ioctl SIOCGIFFLAGS");
1987
} else if(network.ifr_flags & IFF_UP) {
1988
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1989
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1991
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
1994
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1996
perror_plus("close");
1998
/* Lower privileges permanently */
2002
perror_plus("setuid");
2007
/* Removes the GPGME temp directory and all files inside */
1300
/* Removes the temp directory used by GPGME */
2008
1301
if(tempdir_created){
2009
struct dirent **direntries = NULL;
2010
struct dirent *direntry = NULL;
2011
int numentries = scandir(tempdir, &direntries, notdotentries,
2013
if (numentries > 0){
2014
for(int i = 0; i < numentries; i++){
2015
direntry = direntries[i];
1303
struct dirent *direntry;
1304
d = opendir(tempdir);
1306
if(errno != ENOENT){
1311
direntry = readdir(d);
1312
if(direntry == NULL){
1315
/* Skip "." and ".." */
1316
if(direntry->d_name[0] == '.'
1317
and (direntry->d_name[1] == '\0'
1318
or (direntry->d_name[1] == '.'
1319
and direntry->d_name[2] == '\0'))){
2016
1322
char *fullname = NULL;
2017
1323
ret = asprintf(&fullname, "%s/%s", tempdir,
2018
1324
direntry->d_name);
2020
perror_plus("asprintf");
2023
1329
ret = remove(fullname);