71
72
INET_ADDRSTRLEN, INET6_ADDRSTRLEN
73
74
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
74
getuid(), getgid(), setuid(),
76
#include <arpa/inet.h> /* inet_pton(), htons */
75
getuid(), getgid(), seteuid(),
77
#include <arpa/inet.h> /* inet_pton(), htons, inet_ntop() */
77
78
#include <iso646.h> /* not, or, and */
78
79
#include <argp.h> /* struct argp_option, error_t, struct
79
80
argp_state, struct argp,
80
81
argp_parse(), ARGP_KEY_ARG,
81
82
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
82
83
#include <signal.h> /* sigemptyset(), sigaddset(),
83
sigaction(), SIGTERM, sigaction,
84
sigaction(), SIGTERM, sig_atomic_t,
86
#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,
87
EX_NOHOST, EX_IOERR, EX_PROTOCOL */
87
90
#include <sys/klog.h> /* klogctl() */
159
187
return buffer_capacity;
190
int add_server(const char *ip, uint16_t port,
191
AvahiIfIndex if_index,
194
server *new_server = malloc(sizeof(server));
195
if(new_server == NULL){
196
perror_plus("malloc");
199
*new_server = (server){ .ip = strdup(ip),
201
.if_index = if_index,
203
if(new_server->ip == NULL){
204
perror_plus("strdup");
207
/* unique case of first server */
208
if (mc.current_server == NULL){
209
new_server->next = new_server;
210
new_server->prev = new_server;
211
mc.current_server = new_server;
212
/* Placing the new server last in the list */
214
new_server->next = mc.current_server;
215
new_server->prev = mc.current_server->prev;
216
new_server->prev->next = new_server;
217
mc.current_server->prev = new_server;
219
ret = clock_gettime(CLOCK_MONOTONIC, &mc.current_server->last_seen);
221
perror_plus("clock_gettime");
163
228
* Initialize GPGME.
165
230
static bool init_gpgme(const char *seckey,
166
231
const char *pubkey, const char *tempdir){
168
232
gpgme_error_t rc;
169
233
gpgme_engine_info_t engine_info;
310
375
gpgme_recipient_t recipient;
311
376
recipient = result->recipients;
313
while(recipient != NULL){
314
fprintf(stderr, "Public key algorithm: %s\n",
315
gpgme_pubkey_algo_name(recipient->pubkey_algo));
316
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
317
fprintf(stderr, "Secret key available: %s\n",
318
recipient->status == GPG_ERR_NO_SECKEY
320
recipient = recipient->next;
377
while(recipient != NULL){
378
fprintf(stderr, "Public key algorithm: %s\n",
379
gpgme_pubkey_algo_name(recipient->pubkey_algo));
380
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
381
fprintf(stderr, "Secret key available: %s\n",
382
recipient->status == GPG_ERR_NO_SECKEY
384
recipient = recipient->next;
880
sig_atomic_t quit_now = 0;
882
/* stop main loop after sigterm has been called */
883
static void handle_sigterm(__attribute__((unused)) int sig){
1072
/* Signal handler that stops main loop after SIGTERM */
1073
static void handle_sigterm(int sig){
1078
signal_received = sig;
888
1079
int old_errno = errno;
1080
/* set main loop to exit */
889
1081
if(mc.simple_poll != NULL){
890
1082
avahi_simple_poll_quit(mc.simple_poll);
892
1084
errno = old_errno;
1088
* This function determines if a directory entry in /sys/class/net
1089
* corresponds to an acceptable network device.
1090
* (This function is passed to scandir(3) as a filter function.)
1092
int good_interface(const struct dirent *if_entry){
1094
char *flagname = NULL;
1095
if(if_entry->d_name[0] == '.'){
1098
int ret = asprintf(&flagname, "%s/%s/flags", sys_class_net,
1101
perror_plus("asprintf");
1104
int flags_fd = (int)TEMP_FAILURE_RETRY(open(flagname, O_RDONLY));
1106
perror_plus("open");
1111
typedef short ifreq_flags; /* ifreq.ifr_flags in netdevice(7) */
1112
/* read line from flags_fd */
1113
ssize_t to_read = 2+(sizeof(ifreq_flags)*2)+1; /* "0x1003\n" */
1114
char *flagstring = malloc((size_t)to_read+1); /* +1 for final \0 */
1115
flagstring[(size_t)to_read] = '\0';
1116
if(flagstring == NULL){
1117
perror_plus("malloc");
1122
ssret = (ssize_t)TEMP_FAILURE_RETRY(read(flags_fd, flagstring,
1125
perror_plus("read");
1139
tmpmax = strtoimax(flagstring, &tmp, 0);
1140
if(errno != 0 or tmp == flagstring or (*tmp != '\0'
1141
and not (isspace(*tmp)))
1142
or tmpmax != (ifreq_flags)tmpmax){
1144
fprintf(stderr, "Invalid flags \"%s\" for interface \"%s\"\n",
1145
flagstring, if_entry->d_name);
1151
ifreq_flags flags = (ifreq_flags)tmpmax;
1152
/* Reject the loopback device */
1153
if(flags & IFF_LOOPBACK){
1155
fprintf(stderr, "Rejecting loopback interface \"%s\"\n",
1160
/* Accept point-to-point devices only if connect_to is specified */
1161
if(connect_to != NULL and (flags & IFF_POINTOPOINT)){
1163
fprintf(stderr, "Accepting point-to-point interface \"%s\"\n",
1168
/* Otherwise, reject non-broadcast-capable devices */
1169
if(not (flags & IFF_BROADCAST)){
1171
fprintf(stderr, "Rejecting non-broadcast interface \"%s\"\n",
1176
/* Reject non-ARP interfaces (including dummy interfaces) */
1177
if(flags & IFF_NOARP){
1179
fprintf(stderr, "Rejecting non-ARP interface \"%s\"\n",
1184
/* Accept this device */
1186
fprintf(stderr, "Interface \"%s\" is acceptable\n",
1192
int notdotentries(const struct dirent *direntry){
1193
/* Skip "." and ".." */
1194
if(direntry->d_name[0] == '.'
1195
and (direntry->d_name[1] == '\0'
1196
or (direntry->d_name[1] == '.'
1197
and direntry->d_name[2] == '\0'))){
1203
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){
1205
struct timespec now;
1206
struct timespec waited_time;
1207
intmax_t block_time;
1210
if(mc.current_server == NULL){
1213
"Wait until first server is found. No timeout!\n");
1215
ret = avahi_simple_poll_iterate(s, -1);
1218
fprintf(stderr, "Check current_server if we should run it,"
1221
/* the current time */
1222
ret = clock_gettime(CLOCK_MONOTONIC, &now);
1224
perror_plus("clock_gettime");
1227
/* Calculating in ms how long time between now and server
1228
who we visted longest time ago. Now - last seen. */
1229
waited_time.tv_sec = (now.tv_sec
1230
- mc.current_server->last_seen.tv_sec);
1231
waited_time.tv_nsec = (now.tv_nsec
1232
- mc.current_server->last_seen.tv_nsec);
1233
/* total time is 10s/10,000ms.
1234
Converting to s from ms by dividing by 1,000,
1235
and ns to ms by dividing by 1,000,000. */
1236
block_time = ((retry_interval
1237
- ((intmax_t)waited_time.tv_sec * 1000))
1238
- ((intmax_t)waited_time.tv_nsec / 1000000));
1241
fprintf(stderr, "Blocking for %ld ms\n", block_time);
1244
if(block_time <= 0){
1245
ret = start_mandos_communication(mc.current_server->ip,
1246
mc.current_server->port,
1247
mc.current_server->if_index,
1248
mc.current_server->af);
1250
avahi_simple_poll_quit(mc.simple_poll);
1253
ret = clock_gettime(CLOCK_MONOTONIC,
1254
&mc.current_server->last_seen);
1256
perror_plus("clock_gettime");
1259
mc.current_server = mc.current_server->next;
1260
block_time = 0; /* Call avahi to find new Mandos
1261
servers, but don't block */
1264
ret = avahi_simple_poll_iterate(s, (int)block_time);
1267
if (ret > 0 or errno != EINTR) {
1268
return (ret != 1) ? ret : 0;
895
1274
int main(int argc, char *argv[]){
896
1275
AvahiSServiceBrowser *sb = NULL;
952
1354
.arg = "SECONDS",
953
1355
.doc = "Maximum delay to wait for interface startup",
1357
{ .name = "retry", .key = 132,
1359
.doc = "Retry interval used when denied by the mandos server",
1362
* These reproduce what we would get without ARGP_NO_HELP
1364
{ .name = "help", .key = '?',
1365
.doc = "Give this help list", .group = -1 },
1366
{ .name = "usage", .key = -3,
1367
.doc = "Give a short usage message", .group = -1 },
1368
{ .name = "version", .key = 'V',
1369
.doc = "Print program version", .group = -1 },
955
1370
{ .name = NULL }
958
1373
error_t parse_opt(int key, char *arg,
959
1374
struct argp_state *state){
961
1377
case 128: /* --debug */
991
1406
delay = strtof(arg, &tmp);
992
1407
if(errno != 0 or tmp == arg or *tmp != '\0'){
993
fprintf(stderr, "Bad delay\n");
1408
argp_error(state, "Bad delay");
1410
case 132: /* --retry */
1412
retry_interval = strtod(arg, &tmp);
1413
if(errno != 0 or tmp == arg or *tmp != '\0'
1414
or (retry_interval * 1000) > INT_MAX){
1415
argp_error(state, "Bad retry interval");
1419
* These reproduce what we would get without ARGP_NO_HELP
1421
case '?': /* --help */
1422
argp_state_help(state, state->out_stream,
1423
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
1424
& ~(unsigned int)ARGP_HELP_EXIT_OK);
1425
case -3: /* --usage */
1426
argp_state_help(state, state->out_stream,
1427
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
1428
case 'V': /* --version */
1429
fprintf(state->out_stream, "%s\n", argp_program_version);
1430
exit(argp_err_exit_status);
1002
1433
return ARGP_ERR_UNKNOWN;
1007
1438
struct argp argp = { .options = options, .parser = parse_opt,
1008
1439
.args_doc = "",
1009
1440
.doc = "Mandos client -- Get and decrypt"
1010
1441
" passwords from a Mandos server" };
1011
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
1012
if(ret == ARGP_ERR_UNKNOWN){
1013
fprintf(stderr, "Unknown error while parsing arguments\n");
1014
exitcode = EXIT_FAILURE;
1442
ret = argp_parse(&argp, argc, argv,
1443
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
1450
perror_plus("argp_parse");
1451
exitcode = EX_OSERR;
1454
exitcode = EX_USAGE;
1027
1492
mc.simple_poll = avahi_simple_poll_new();
1028
1493
if(mc.simple_poll == NULL){
1029
1494
fprintf(stderr, "Avahi: Failed to create simple poll object.\n");
1030
exitcode = EXIT_FAILURE;
1495
exitcode = EX_UNAVAILABLE;
1034
1499
sigemptyset(&sigterm_action.sa_mask);
1035
1500
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1037
perror("sigaddset");
1038
exitcode = EXIT_FAILURE;
1502
perror_plus("sigaddset");
1503
exitcode = EX_OSERR;
1041
1506
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1043
perror("sigaddset");
1044
exitcode = EXIT_FAILURE;
1508
perror_plus("sigaddset");
1509
exitcode = EX_OSERR;
1047
1512
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1049
perror("sigaddset");
1050
exitcode = EXIT_FAILURE;
1053
ret = sigaction(SIGTERM, &sigterm_action, &old_sigterm_action);
1055
perror("sigaction");
1056
exitcode = EXIT_FAILURE;
1514
perror_plus("sigaddset");
1515
exitcode = EX_OSERR;
1518
/* Need to check if the handler is SIG_IGN before handling:
1519
| [[info:libc:Initial Signal Actions]] |
1520
| [[info:libc:Basic Signal Handling]] |
1522
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1524
perror_plus("sigaction");
1527
if(old_sigterm_action.sa_handler != SIG_IGN){
1528
ret = sigaction(SIGINT, &sigterm_action, NULL);
1530
perror_plus("sigaction");
1531
exitcode = EX_OSERR;
1535
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1537
perror_plus("sigaction");
1540
if(old_sigterm_action.sa_handler != SIG_IGN){
1541
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1543
perror_plus("sigaction");
1544
exitcode = EX_OSERR;
1548
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1550
perror_plus("sigaction");
1553
if(old_sigterm_action.sa_handler != SIG_IGN){
1554
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1556
perror_plus("sigaction");
1557
exitcode = EX_OSERR;
1060
1562
/* If the interface is down, bring it up */
1061
if(interface[0] != '\0'){
1563
if(strcmp(interface, "none") != 0){
1564
if_index = (AvahiIfIndex) if_nametoindex(interface);
1566
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1567
exitcode = EX_UNAVAILABLE;
1575
/* Re-raise priviliges */
1579
perror_plus("seteuid");
1062
1582
#ifdef __linux__
1063
1583
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1064
messages to mess up the prompt */
1584
messages about the network interface to mess up the prompt */
1065
1585
ret = klogctl(8, NULL, 5);
1066
1586
bool restore_loglevel = true;
1068
1588
restore_loglevel = false;
1589
perror_plus("klogctl");
1071
1591
#endif /* __linux__ */
1073
1593
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1076
exitcode = EXIT_FAILURE;
1595
perror_plus("socket");
1596
exitcode = EX_OSERR;
1077
1597
#ifdef __linux__
1078
1598
if(restore_loglevel){
1079
1599
ret = klogctl(7, NULL, 0);
1601
perror_plus("klogctl");
1084
1604
#endif /* __linux__ */
1605
/* Lower privileges */
1609
perror_plus("seteuid");
1087
1613
strcpy(network.ifr_name, interface);
1088
1614
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1090
perror("ioctl SIOCGIFFLAGS");
1616
perror_plus("ioctl SIOCGIFFLAGS");
1091
1617
#ifdef __linux__
1092
1618
if(restore_loglevel){
1093
1619
ret = klogctl(7, NULL, 0);
1621
perror_plus("klogctl");
1098
1624
#endif /* __linux__ */
1099
exitcode = EXIT_FAILURE;
1625
exitcode = EX_OSERR;
1626
/* Lower privileges */
1630
perror_plus("seteuid");
1102
1634
if((network.ifr_flags & IFF_UP) == 0){
1103
1635
network.ifr_flags |= IFF_UP;
1636
take_down_interface = true;
1104
1637
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1106
perror("ioctl SIOCSIFFLAGS");
1107
exitcode = EXIT_FAILURE;
1639
take_down_interface = false;
1640
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1641
exitcode = EX_OSERR;
1108
1642
#ifdef __linux__
1109
1643
if(restore_loglevel){
1110
1644
ret = klogctl(7, NULL, 0);
1646
perror_plus("klogctl");
1115
1649
#endif /* __linux__ */
1650
/* Lower privileges */
1654
perror_plus("seteuid");
1119
/* sleep checking until interface is running */
1659
/* Sleep checking until interface is running.
1660
Check every 0.25s, up to total time of delay */
1120
1661
for(int i=0; i < delay * 4; i++){
1121
1662
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1123
perror("ioctl SIOCGIFFLAGS");
1664
perror_plus("ioctl SIOCGIFFLAGS");
1124
1665
} else if(network.ifr_flags & IFF_RUNNING){
1127
1668
struct timespec sleeptime = { .tv_nsec = 250000000 };
1128
1669
ret = nanosleep(&sleeptime, NULL);
1129
1670
if(ret == -1 and errno != EINTR){
1130
perror("nanosleep");
1671
perror_plus("nanosleep");
1133
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1674
if(not take_down_interface){
1675
/* We won't need the socket anymore */
1676
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1678
perror_plus("close");
1137
1681
#ifdef __linux__
1138
1682
if(restore_loglevel){
1139
1683
/* Restores kernel loglevel to default */
1140
1684
ret = klogctl(7, NULL, 0);
1686
perror_plus("klogctl");
1145
1689
#endif /* __linux__ */
1690
/* Lower privileges */
1692
if(take_down_interface){
1693
/* Lower privileges */
1696
perror_plus("seteuid");
1699
/* Lower privileges permanently */
1702
perror_plus("setuid");
1162
1711
ret = init_gnutls_global(pubkey, seckey);
1164
1713
fprintf(stderr, "init_gnutls_global failed\n");
1165
exitcode = EXIT_FAILURE;
1714
exitcode = EX_UNAVAILABLE;
1168
1717
gnutls_initialized = true;
1171
1724
if(mkdtemp(tempdir) == NULL){
1725
perror_plus("mkdtemp");
1175
1728
tempdir_created = true;
1177
1734
if(not init_gpgme(pubkey, seckey, tempdir)){
1178
1735
fprintf(stderr, "init_gpgme failed\n");
1179
exitcode = EXIT_FAILURE;
1736
exitcode = EX_UNAVAILABLE;
1182
1739
gpgme_initialized = true;
1185
if(interface[0] != '\0'){
1186
if_index = (AvahiIfIndex) if_nametoindex(interface);
1188
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1189
exitcode = EXIT_FAILURE;
1194
1746
if(connect_to != NULL){
1298
1888
if(gpgme_initialized){
1299
1889
gpgme_release(mc.ctx);
1302
/* Removes the temp directory used by GPGME */
1892
/* Cleans up the circular linked list of Mandos servers the client
1894
if(mc.current_server != NULL){
1895
mc.current_server->prev->next = NULL;
1896
while(mc.current_server != NULL){
1897
server *next = mc.current_server->next;
1898
free(mc.current_server);
1899
mc.current_server = next;
1903
/* Take down the network interface */
1904
if(take_down_interface){
1905
/* Re-raise priviliges */
1909
perror_plus("seteuid");
1912
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1914
perror_plus("ioctl SIOCGIFFLAGS");
1915
} else if(network.ifr_flags & IFF_UP) {
1916
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1917
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1919
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
1922
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1924
perror_plus("close");
1926
/* Lower privileges permanently */
1930
perror_plus("setuid");
1935
/* Removes the GPGME temp directory and all files inside */
1303
1936
if(tempdir_created){
1305
struct dirent *direntry;
1306
d = opendir(tempdir);
1308
if(errno != ENOENT){
1313
direntry = readdir(d);
1314
if(direntry == NULL){
1317
/* Skip "." and ".." */
1318
if(direntry->d_name[0] == '.'
1319
and (direntry->d_name[1] == '\0'
1320
or (direntry->d_name[1] == '.'
1321
and direntry->d_name[2] == '\0'))){
1937
struct dirent **direntries = NULL;
1938
struct dirent *direntry = NULL;
1939
ret = scandir(tempdir, &direntries, notdotentries, alphasort);
1941
for(int i = 0; i < ret; i++){
1942
direntry = direntries[i];
1324
1943
char *fullname = NULL;
1325
1944
ret = asprintf(&fullname, "%s/%s", tempdir,
1326
1945
direntry->d_name);
1947
perror_plus("asprintf");
1331
1950
ret = remove(fullname);