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 */
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
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.
966
1078
signal_received = sig;
967
1079
int old_errno = errno;
1080
/* set main loop to exit */
968
1081
if(mc.simple_poll != NULL){
969
1082
avahi_simple_poll_quit(mc.simple_poll);
971
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;
974
1274
int main(int argc, char *argv[]){
975
1275
AvahiSServiceBrowser *sb = NULL;
1032
1354
.arg = "SECONDS",
1033
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 },
1035
1370
{ .name = NULL }
1038
1373
error_t parse_opt(int key, char *arg,
1039
1374
struct argp_state *state){
1041
1377
case 128: /* --debug */
1071
1406
delay = strtof(arg, &tmp);
1072
1407
if(errno != 0 or tmp == arg or *tmp != '\0'){
1073
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);
1082
1433
return ARGP_ERR_UNKNOWN;
1087
1438
struct argp argp = { .options = options, .parser = parse_opt,
1088
1439
.args_doc = "",
1089
1440
.doc = "Mandos client -- Get and decrypt"
1090
1441
" passwords from a Mandos server" };
1091
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
1092
if(ret == ARGP_ERR_UNKNOWN){
1093
fprintf(stderr, "Unknown error while parsing arguments\n");
1094
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;
1460
/* Work around Debian bug #633582:
1461
<http://bugs.debian.org/633582> */
1464
/* Re-raise priviliges */
1468
perror_plus("seteuid");
1471
int seckey_fd = open(PATHDIR "/" SECKEY, O_RDONLY);
1472
if(seckey_fd == -1){
1473
perror_plus("open");
1475
ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));
1477
perror_plus("fstat");
1479
if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){
1480
ret = fchown(seckey_fd, uid, gid);
1482
perror_plus("fchown");
1486
TEMP_FAILURE_RETRY(close(seckey_fd));
1489
int pubkey_fd = open(PATHDIR "/" PUBKEY, O_RDONLY);
1490
if(pubkey_fd == -1){
1491
perror_plus("open");
1493
ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));
1495
perror_plus("fstat");
1497
if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){
1498
ret = fchown(pubkey_fd, uid, gid);
1500
perror_plus("fchown");
1504
TEMP_FAILURE_RETRY(close(pubkey_fd));
1507
/* Lower privileges */
1511
perror_plus("seteuid");
1100
1516
avahi_set_log_function(empty_log);
1519
if(interface[0] == '\0'){
1520
struct dirent **direntries;
1521
ret = scandir(sys_class_net, &direntries, good_interface,
1524
/* Pick the first good interface */
1525
interface = strdup(direntries[0]->d_name);
1527
fprintf(stderr, "Using interface \"%s\"\n", interface);
1529
if(interface == NULL){
1530
perror_plus("malloc");
1532
exitcode = EXIT_FAILURE;
1538
fprintf(stderr, "Could not find a network interface\n");
1539
exitcode = EXIT_FAILURE;
1103
1544
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
1104
1545
from the signal handler */
1137
1578
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1139
perror("sigaction");
1140
return EXIT_FAILURE;
1580
perror_plus("sigaction");
1142
1583
if(old_sigterm_action.sa_handler != SIG_IGN){
1143
1584
ret = sigaction(SIGINT, &sigterm_action, NULL);
1145
perror("sigaction");
1146
exitcode = EXIT_FAILURE;
1586
perror_plus("sigaction");
1587
exitcode = EX_OSERR;
1150
1591
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1152
perror("sigaction");
1153
return EXIT_FAILURE;
1593
perror_plus("sigaction");
1155
1596
if(old_sigterm_action.sa_handler != SIG_IGN){
1156
1597
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1158
perror("sigaction");
1159
exitcode = EXIT_FAILURE;
1599
perror_plus("sigaction");
1600
exitcode = EX_OSERR;
1163
1604
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1165
perror("sigaction");
1166
return EXIT_FAILURE;
1606
perror_plus("sigaction");
1168
1609
if(old_sigterm_action.sa_handler != SIG_IGN){
1169
1610
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1171
perror("sigaction");
1172
exitcode = EXIT_FAILURE;
1612
perror_plus("sigaction");
1613
exitcode = EX_OSERR;
1177
1618
/* If the interface is down, bring it up */
1178
if(interface[0] != '\0'){
1619
if(strcmp(interface, "none") != 0){
1179
1620
if_index = (AvahiIfIndex) if_nametoindex(interface);
1180
1621
if(if_index == 0){
1181
1622
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1182
exitcode = EXIT_FAILURE;
1623
exitcode = EX_UNAVAILABLE;
1631
/* Re-raise priviliges */
1635
perror_plus("seteuid");
1190
1638
#ifdef __linux__
1191
1639
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1192
messages to mess up the prompt */
1640
messages about the network interface to mess up the prompt */
1193
1641
ret = klogctl(8, NULL, 5);
1194
1642
bool restore_loglevel = true;
1196
1644
restore_loglevel = false;
1645
perror_plus("klogctl");
1199
1647
#endif /* __linux__ */
1201
1649
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1204
exitcode = EXIT_FAILURE;
1651
perror_plus("socket");
1652
exitcode = EX_OSERR;
1205
1653
#ifdef __linux__
1206
1654
if(restore_loglevel){
1207
1655
ret = klogctl(7, NULL, 0);
1657
perror_plus("klogctl");
1212
1660
#endif /* __linux__ */
1661
/* Lower privileges */
1665
perror_plus("seteuid");
1215
1669
strcpy(network.ifr_name, interface);
1216
1670
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1218
perror("ioctl SIOCGIFFLAGS");
1672
perror_plus("ioctl SIOCGIFFLAGS");
1219
1673
#ifdef __linux__
1220
1674
if(restore_loglevel){
1221
1675
ret = klogctl(7, NULL, 0);
1677
perror_plus("klogctl");
1226
1680
#endif /* __linux__ */
1227
exitcode = EXIT_FAILURE;
1681
exitcode = EX_OSERR;
1682
/* Lower privileges */
1686
perror_plus("seteuid");
1230
1690
if((network.ifr_flags & IFF_UP) == 0){
1233
1693
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1235
1695
take_down_interface = false;
1236
perror("ioctl SIOCSIFFLAGS");
1237
exitcode = EXIT_FAILURE;
1696
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1697
exitcode = EX_OSERR;
1238
1698
#ifdef __linux__
1239
1699
if(restore_loglevel){
1240
1700
ret = klogctl(7, NULL, 0);
1702
perror_plus("klogctl");
1245
1705
#endif /* __linux__ */
1706
/* Lower privileges */
1710
perror_plus("seteuid");
1249
/* sleep checking until interface is running */
1715
/* Sleep checking until interface is running.
1716
Check every 0.25s, up to total time of delay */
1250
1717
for(int i=0; i < delay * 4; i++){
1251
1718
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1253
perror("ioctl SIOCGIFFLAGS");
1720
perror_plus("ioctl SIOCGIFFLAGS");
1254
1721
} else if(network.ifr_flags & IFF_RUNNING){
1257
1724
struct timespec sleeptime = { .tv_nsec = 250000000 };
1258
1725
ret = nanosleep(&sleeptime, NULL);
1259
1726
if(ret == -1 and errno != EINTR){
1260
perror("nanosleep");
1727
perror_plus("nanosleep");
1263
1730
if(not take_down_interface){
1264
1731
/* We won't need the socket anymore */
1265
1732
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1734
perror_plus("close");
1270
1737
#ifdef __linux__
1491
1963
ret = seteuid(0);
1965
perror_plus("seteuid");
1495
1967
if(geteuid() == 0){
1496
1968
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1498
perror("ioctl SIOCGIFFLAGS");
1970
perror_plus("ioctl SIOCGIFFLAGS");
1499
1971
} else if(network.ifr_flags & IFF_UP) {
1500
network.ifr_flags &= ~IFF_UP; /* clear flag */
1972
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1501
1973
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1503
perror("ioctl SIOCSIFFLAGS");
1975
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
1506
1978
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1980
perror_plus("close");
1510
/* Lower privileges, permanently this time */
1982
/* Lower privileges permanently */
1512
1984
ret = setuid(uid);
1986
perror_plus("setuid");
1519
/* Removes the temp directory used by GPGME */
1991
/* Removes the GPGME temp directory and all files inside */
1520
1992
if(tempdir_created){
1522
struct dirent *direntry;
1523
d = opendir(tempdir);
1525
if(errno != ENOENT){
1530
direntry = readdir(d);
1531
if(direntry == NULL){
1534
/* Skip "." and ".." */
1535
if(direntry->d_name[0] == '.'
1536
and (direntry->d_name[1] == '\0'
1537
or (direntry->d_name[1] == '.'
1538
and direntry->d_name[2] == '\0'))){
1993
struct dirent **direntries = NULL;
1994
struct dirent *direntry = NULL;
1995
ret = scandir(tempdir, &direntries, notdotentries, alphasort);
1997
for(int i = 0; i < ret; i++){
1998
direntry = direntries[i];
1541
1999
char *fullname = NULL;
1542
2000
ret = asprintf(&fullname, "%s/%s", tempdir,
1543
2001
direntry->d_name);
2003
perror_plus("asprintf");
1548
2006
ret = remove(fullname);