62
62
#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,
64
64
#include <assert.h> /* assert() */
65
#include <errno.h> /* perror(), errno,
66
program_invocation_short_name */
67
#include <time.h> /* nanosleep(), time(), sleep() */
65
#include <errno.h> /* perror(), errno */
66
#include <time.h> /* nanosleep(), time() */
68
67
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
69
68
SIOCSIFFLAGS, if_indextoname(),
70
69
if_nametoindex(), IF_NAMESIZE */
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;
893
738
fprintf(stderr, "Closing TLS session\n");
902
ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);
907
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
741
gnutls_bye(session, GNUTLS_SHUT_RDWR);
909
743
if(buffer_length > 0){
910
ssize_t decrypted_buffer_size;
911
744
decrypted_buffer_size = pgp_packet_decrypt(buffer,
913
746
&decrypted_buffer);
914
747
if(decrypted_buffer_size >= 0){
917
749
while(written < (size_t) decrypted_buffer_size){
923
750
ret = (int)fwrite(decrypted_buffer + written, 1,
924
751
(size_t)decrypted_buffer_size - written,
926
753
if(ret == 0 and ferror(stdout)){
929
755
fprintf(stderr, "Error writing encrypted data: %s\n",
930
756
strerror(errno));
935
761
written += (size_t)ret;
763
free(decrypted_buffer);
941
771
/* Shutdown procedure */
946
free(decrypted_buffer);
949
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
955
perror_plus("close");
957
gnutls_deinit(session);
775
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
779
gnutls_deinit(session);
783
sig_atomic_t quit_now = 0;
967
785
static void resolve_callback(AvahiSServiceResolver *r,
968
786
AvahiIfIndex interface,
969
787
AvahiProtocol proto,
1073
/* Signal handler that stops main loop after SIGTERM */
1074
static void handle_sigterm(int sig){
884
/* stop main loop after sigterm has been called */
885
static void handle_sigterm(__attribute__((unused)) int sig){
1079
signal_received = sig;
1080
890
int old_errno = errno;
1081
/* set main loop to exit */
1082
891
if(mc.simple_poll != NULL){
1083
892
avahi_simple_poll_quit(mc.simple_poll);
1085
894
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
897
int main(int argc, char *argv[]){
1276
898
AvahiSServiceBrowser *sb = NULL;
1355
955
.arg = "SECONDS",
1356
956
.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
958
{ .name = NULL }
1374
961
error_t parse_opt(int key, char *arg,
1375
962
struct argp_state *state){
1378
964
case 128: /* --debug */
1407
994
delay = strtof(arg, &tmp);
1408
995
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");
996
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
1005
return ARGP_ERR_UNKNOWN;
1440
1010
struct argp argp = { .options = options, .parser = parse_opt,
1441
1011
.args_doc = "",
1442
1012
.doc = "Mandos client -- Get and decrypt"
1443
1013
" 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");
1014
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
1015
if(ret == ARGP_ERR_UNKNOWN){
1016
fprintf(stderr, "Unknown error while parsing arguments\n");
1017
exitcode = EXIT_FAILURE;
1522
1023
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
1026
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
1551
1027
from the signal handler */
1554
1030
mc.simple_poll = avahi_simple_poll_new();
1555
1031
if(mc.simple_poll == NULL){
1556
1032
fprintf(stderr, "Avahi: Failed to create simple poll object.\n");
1557
exitcode = EX_UNAVAILABLE;
1033
exitcode = EXIT_FAILURE;
1561
1037
sigemptyset(&sigterm_action.sa_mask);
1562
1038
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1564
perror_plus("sigaddset");
1565
exitcode = EX_OSERR;
1040
perror("sigaddset");
1041
exitcode = EXIT_FAILURE;
1568
1044
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1570
perror_plus("sigaddset");
1571
exitcode = EX_OSERR;
1046
perror("sigaddset");
1047
exitcode = EXIT_FAILURE;
1574
1050
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;
1052
perror("sigaddset");
1053
exitcode = EXIT_FAILURE;
1056
ret = sigaction(SIGTERM, &sigterm_action, &old_sigterm_action);
1058
perror("sigaction");
1059
exitcode = EXIT_FAILURE;
1624
1063
/* If the interface is down, bring it up */
1625
if(strcmp(interface, "none") != 0){
1064
if(interface[0] != '\0'){
1626
1065
if_index = (AvahiIfIndex) if_nametoindex(interface);
1627
1066
if(if_index == 0){
1628
1067
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1629
exitcode = EX_UNAVAILABLE;
1068
exitcode = EXIT_FAILURE;
1637
/* Re-raise priviliges */
1641
perror_plus("seteuid");
1644
1076
#ifdef __linux__
1645
1077
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1646
messages about the network interface to mess up the prompt */
1078
messages to mess up the prompt */
1647
1079
ret = klogctl(8, NULL, 5);
1648
1080
bool restore_loglevel = true;
1650
1082
restore_loglevel = false;
1651
perror_plus("klogctl");
1653
1085
#endif /* __linux__ */
1655
1087
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1657
perror_plus("socket");
1658
exitcode = EX_OSERR;
1090
exitcode = EXIT_FAILURE;
1659
1091
#ifdef __linux__
1660
1092
if(restore_loglevel){
1661
1093
ret = klogctl(7, NULL, 0);
1663
perror_plus("klogctl");
1666
1098
#endif /* __linux__ */
1667
/* Lower privileges */
1671
perror_plus("seteuid");
1675
1101
strcpy(network.ifr_name, interface);
1676
1102
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1678
perror_plus("ioctl SIOCGIFFLAGS");
1104
perror("ioctl SIOCGIFFLAGS");
1679
1105
#ifdef __linux__
1680
1106
if(restore_loglevel){
1681
1107
ret = klogctl(7, NULL, 0);
1683
perror_plus("klogctl");
1686
1112
#endif /* __linux__ */
1687
exitcode = EX_OSERR;
1688
/* Lower privileges */
1692
perror_plus("seteuid");
1113
exitcode = EXIT_FAILURE;
1696
1116
if((network.ifr_flags & IFF_UP) == 0){
1699
1119
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1701
1121
take_down_interface = false;
1702
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1703
exitcode = EX_OSERR;
1122
perror("ioctl SIOCSIFFLAGS");
1123
exitcode = EXIT_FAILURE;
1704
1124
#ifdef __linux__
1705
1125
if(restore_loglevel){
1706
1126
ret = klogctl(7, NULL, 0);
1708
perror_plus("klogctl");
1711
1131
#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 */
1135
/* sleep checking until interface is running */
1723
1136
for(int i=0; i < delay * 4; i++){
1724
1137
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1726
perror_plus("ioctl SIOCGIFFLAGS");
1139
perror("ioctl SIOCGIFFLAGS");
1727
1140
} else if(network.ifr_flags & IFF_RUNNING){
1730
1143
struct timespec sleeptime = { .tv_nsec = 250000000 };
1731
1144
ret = nanosleep(&sleeptime, NULL);
1732
1145
if(ret == -1 and errno != EINTR){
1733
perror_plus("nanosleep");
1146
perror("nanosleep");
1736
1149
if(not take_down_interface){
1737
1150
/* We won't need the socket anymore */
1738
1151
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1740
perror_plus("close");
1743
1156
#ifdef __linux__
1960
1356
if(gpgme_initialized){
1961
1357
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
1360
/* Take down the network interface */
1976
1361
if(take_down_interface){
1977
/* Re-raise priviliges */
1362
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1981
perror_plus("seteuid");
1364
perror("ioctl SIOCGIFFLAGS");
1365
} else if(network.ifr_flags & IFF_UP) {
1366
network.ifr_flags &= ~IFF_UP; /* clear flag */
1367
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1369
perror("ioctl SIOCSIFFLAGS");
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");
1372
ret = (int)TEMP_FAILURE_RETRY(close(sd));
2007
/* Removes the GPGME temp directory and all files inside */
1378
/* Removes the temp directory used by GPGME */
2008
1379
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];
1381
struct dirent *direntry;
1382
d = opendir(tempdir);
1384
if(errno != ENOENT){
1389
direntry = readdir(d);
1390
if(direntry == NULL){
1393
/* Skip "." and ".." */
1394
if(direntry->d_name[0] == '.'
1395
and (direntry->d_name[1] == '\0'
1396
or (direntry->d_name[1] == '.'
1397
and direntry->d_name[2] == '\0'))){
2016
1400
char *fullname = NULL;
2017
1401
ret = asprintf(&fullname, "%s/%s", tempdir,
2018
1402
direntry->d_name);
2020
perror_plus("asprintf");
2023
1407
ret = remove(fullname);