43
43
stdout, ferror(), remove() */
44
44
#include <stdint.h> /* uint16_t, uint32_t */
45
45
#include <stddef.h> /* NULL, size_t, ssize_t */
46
#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
46
#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),
48
48
#include <stdbool.h> /* bool, false, true */
49
49
#include <string.h> /* memset(), strcmp(), strlen(),
50
50
strerror(), asprintf(), strcpy() */
62
62
#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,
64
64
#include <assert.h> /* assert() */
65
#include <errno.h> /* perror(), errno */
66
#include <time.h> /* nanosleep(), time() */
65
#include <errno.h> /* perror(), errno,
66
program_invocation_short_name */
67
#include <time.h> /* nanosleep(), time(), sleep() */
67
68
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
68
69
SIOCSIFFLAGS, if_indextoname(),
69
70
if_nametoindex(), IF_NAMESIZE */
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,
135
151
gnutls_dh_params_t dh_params;
136
152
const char *priority;
154
server *current_server;
138
155
} mandos_context;
140
157
/* global context so signal handler can reach it*/
141
158
mandos_context mc = { .simple_poll = NULL, .server = NULL,
142
159
.dh_bits = 1024, .priority = "SECURE256"
143
":!CTYPE-X.509:+CTYPE-OPENPGP" };
160
":!CTYPE-X.509:+CTYPE-OPENPGP",
161
.current_server = NULL };
163
sig_atomic_t quit_now = 0;
164
int signal_received = 0;
166
/* Function to use when printing errors */
167
void perror_plus(const char *print_text){
168
fprintf(stderr, "Mandos plugin %s: ",
169
program_invocation_short_name);
146
174
* Make additional room in "buffer" for at least BUFFER_SIZE more
159
187
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");
163
229
* Initialize GPGME.
165
231
static bool init_gpgme(const char *seckey,
166
232
const char *pubkey, const char *tempdir){
168
233
gpgme_error_t rc;
169
234
gpgme_engine_info_t engine_info;
965
1079
signal_received = sig;
966
1080
int old_errno = errno;
1081
/* set main loop to exit */
967
1082
if(mc.simple_poll != NULL){
968
1083
avahi_simple_poll_quit(mc.simple_poll);
970
1085
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;
973
1275
int main(int argc, char *argv[]){
974
1276
AvahiSServiceBrowser *sb = NULL;
1031
1355
.arg = "SECONDS",
1032
1356
.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 },
1034
1371
{ .name = NULL }
1037
1374
error_t parse_opt(int key, char *arg,
1038
1375
struct argp_state *state){
1040
1378
case 128: /* --debug */
1070
1407
delay = strtof(arg, &tmp);
1071
1408
if(errno != 0 or tmp == arg or *tmp != '\0'){
1072
fprintf(stderr, "Bad delay\n");
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");
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);
1081
1435
return ARGP_ERR_UNKNOWN;
1086
1440
struct argp argp = { .options = options, .parser = parse_opt,
1087
1441
.args_doc = "",
1088
1442
.doc = "Mandos client -- Get and decrypt"
1089
1443
" passwords from a Mandos server" };
1090
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
1091
if(ret == ARGP_ERR_UNKNOWN){
1092
fprintf(stderr, "Unknown error while parsing arguments\n");
1093
exitcode = EXIT_FAILURE;
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");
1099
1522
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;
1102
1550
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
1103
1551
from the signal handler */
1136
1584
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1138
perror("sigaction");
1139
return EXIT_FAILURE;
1586
perror_plus("sigaction");
1141
1589
if(old_sigterm_action.sa_handler != SIG_IGN){
1142
1590
ret = sigaction(SIGINT, &sigterm_action, NULL);
1144
perror("sigaction");
1145
exitcode = EXIT_FAILURE;
1592
perror_plus("sigaction");
1593
exitcode = EX_OSERR;
1149
1597
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1151
perror("sigaction");
1152
return EXIT_FAILURE;
1599
perror_plus("sigaction");
1154
1602
if(old_sigterm_action.sa_handler != SIG_IGN){
1155
1603
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1157
perror("sigaction");
1158
exitcode = EXIT_FAILURE;
1605
perror_plus("sigaction");
1606
exitcode = EX_OSERR;
1162
1610
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1164
perror("sigaction");
1165
return EXIT_FAILURE;
1612
perror_plus("sigaction");
1167
1615
if(old_sigterm_action.sa_handler != SIG_IGN){
1168
1616
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1170
perror("sigaction");
1171
exitcode = EXIT_FAILURE;
1618
perror_plus("sigaction");
1619
exitcode = EX_OSERR;
1176
1624
/* If the interface is down, bring it up */
1177
if(interface[0] != '\0'){
1625
if(strcmp(interface, "none") != 0){
1178
1626
if_index = (AvahiIfIndex) if_nametoindex(interface);
1179
1627
if(if_index == 0){
1180
1628
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1181
exitcode = EXIT_FAILURE;
1629
exitcode = EX_UNAVAILABLE;
1637
/* Re-raise priviliges */
1641
perror_plus("seteuid");
1189
1644
#ifdef __linux__
1190
1645
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1191
messages to mess up the prompt */
1646
messages about the network interface to mess up the prompt */
1192
1647
ret = klogctl(8, NULL, 5);
1193
1648
bool restore_loglevel = true;
1195
1650
restore_loglevel = false;
1651
perror_plus("klogctl");
1198
1653
#endif /* __linux__ */
1200
1655
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1203
exitcode = EXIT_FAILURE;
1657
perror_plus("socket");
1658
exitcode = EX_OSERR;
1204
1659
#ifdef __linux__
1205
1660
if(restore_loglevel){
1206
1661
ret = klogctl(7, NULL, 0);
1663
perror_plus("klogctl");
1211
1666
#endif /* __linux__ */
1667
/* Lower privileges */
1671
perror_plus("seteuid");
1214
1675
strcpy(network.ifr_name, interface);
1215
1676
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1217
perror("ioctl SIOCGIFFLAGS");
1678
perror_plus("ioctl SIOCGIFFLAGS");
1218
1679
#ifdef __linux__
1219
1680
if(restore_loglevel){
1220
1681
ret = klogctl(7, NULL, 0);
1683
perror_plus("klogctl");
1225
1686
#endif /* __linux__ */
1226
exitcode = EXIT_FAILURE;
1687
exitcode = EX_OSERR;
1688
/* Lower privileges */
1692
perror_plus("seteuid");
1229
1696
if((network.ifr_flags & IFF_UP) == 0){
1232
1699
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1234
1701
take_down_interface = false;
1235
perror("ioctl SIOCSIFFLAGS");
1236
exitcode = EXIT_FAILURE;
1702
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1703
exitcode = EX_OSERR;
1237
1704
#ifdef __linux__
1238
1705
if(restore_loglevel){
1239
1706
ret = klogctl(7, NULL, 0);
1708
perror_plus("klogctl");
1244
1711
#endif /* __linux__ */
1712
/* Lower privileges */
1716
perror_plus("seteuid");
1248
/* sleep checking until interface is running */
1721
/* Sleep checking until interface is running.
1722
Check every 0.25s, up to total time of delay */
1249
1723
for(int i=0; i < delay * 4; i++){
1250
1724
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1252
perror("ioctl SIOCGIFFLAGS");
1726
perror_plus("ioctl SIOCGIFFLAGS");
1253
1727
} else if(network.ifr_flags & IFF_RUNNING){
1256
1730
struct timespec sleeptime = { .tv_nsec = 250000000 };
1257
1731
ret = nanosleep(&sleeptime, NULL);
1258
1732
if(ret == -1 and errno != EINTR){
1259
perror("nanosleep");
1733
perror_plus("nanosleep");
1262
1736
if(not take_down_interface){
1263
1737
/* We won't need the socket anymore */
1264
1738
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1740
perror_plus("close");
1269
1743
#ifdef __linux__
1469
1960
if(gpgme_initialized){
1470
1961
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;
1473
1975
/* Take down the network interface */
1474
1976
if(take_down_interface){
1475
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1977
/* Re-raise priviliges */
1477
perror("ioctl SIOCGIFFLAGS");
1478
} else if(network.ifr_flags & IFF_UP) {
1479
network.ifr_flags &= ~IFF_UP; /* clear flag */
1480
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1482
perror("ioctl SIOCSIFFLAGS");
1981
perror_plus("seteuid");
1485
ret = (int)TEMP_FAILURE_RETRY(close(sd));
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");
1491
/* Removes the temp directory used by GPGME */
2007
/* Removes the GPGME temp directory and all files inside */
1492
2008
if(tempdir_created){
1494
struct dirent *direntry;
1495
d = opendir(tempdir);
1497
if(errno != ENOENT){
1502
direntry = readdir(d);
1503
if(direntry == NULL){
1506
/* Skip "." and ".." */
1507
if(direntry->d_name[0] == '.'
1508
and (direntry->d_name[1] == '\0'
1509
or (direntry->d_name[1] == '.'
1510
and direntry->d_name[2] == '\0'))){
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];
1513
2016
char *fullname = NULL;
1514
2017
ret = asprintf(&fullname, "%s/%s", tempdir,
1515
2018
direntry->d_name);
2020
perror_plus("asprintf");
1520
2023
ret = remove(fullname);