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, srand(),
46
#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
47
srand(), strtof(), abort() */
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#include <stdbool.h> /* bool, false, true */
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#include <string.h> /* memset(), strcmp(), strlen(),
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strerror(), asprintf(), strcpy() */
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#include <signal.h> /* sigemptyset(), sigaddset(),
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sigaction(), SIGTERM, sig_atomic_t,
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#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,
86
EX_NOHOST, EX_IOERR, EX_PROTOCOL */
89
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#include <sys/klog.h> /* klogctl() */
127
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static const char mandos_protocol_version[] = "1";
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const char *argp_program_version = "mandos-client " VERSION;
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127
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
128
static const char sys_class_net[] = "/sys/class/net";
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char *connect_to = NULL;
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/* Used for passing in values through the Avahi callback functions */
628
617
if(if_index == AVAHI_IF_UNSPEC){
629
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fprintf(stderr, "An IPv6 link-local address is incomplete"
630
619
" without a network interface\n");
634
622
/* Set the network interface number as scope */
863
829
(size_t)decrypted_buffer_size - written,
865
831
if(ret == 0 and ferror(stdout)){
868
833
fprintf(stderr, "Error writing encrypted data: %s\n",
869
834
strerror(errno));
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written += (size_t)ret;
1020
976
errno = old_errno;
980
* This function determines if a directory entry in /sys/class/net
981
* corresponds to an acceptable network device.
982
* (This function is passed to scandir(3) as a filter function.)
984
int good_interface(const struct dirent *if_entry){
986
char *flagname = NULL;
987
int ret = asprintf(&flagname, "%s/%s/flags", sys_class_net,
993
if(if_entry->d_name[0] == '.'){
996
int flags_fd = (int)TEMP_FAILURE_RETRY(open(flagname, O_RDONLY));
1001
typedef short ifreq_flags; /* ifreq.ifr_flags in netdevice(7) */
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/* read line from flags_fd */
1003
ssize_t to_read = (sizeof(ifreq_flags)*2)+3; /* "0x1003\n" */
1004
char *flagstring = malloc((size_t)to_read);
1005
if(flagstring == NULL){
1011
ssret = (ssize_t)TEMP_FAILURE_RETRY(read(flags_fd, flagstring,
1028
tmpmax = strtoimax(flagstring, &tmp, 0);
1029
if(errno != 0 or tmp == flagstring or (*tmp != '\0'
1030
and not (isspace(*tmp)))
1031
or tmpmax != (ifreq_flags)tmpmax){
1036
ifreq_flags flags = (ifreq_flags)tmpmax;
1037
/* Reject the loopback device */
1038
if(flags & IFF_LOOPBACK){
1041
/* Accept point-to-point devices only if connect_to is specified */
1042
if(connect_to != NULL and (flags & IFF_POINTOPOINT)){
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/* Otherwise, reject non-broadcast-capable devices */
1046
if(not (flags & IFF_BROADCAST)){
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/* Accept this device */
1023
1053
int main(int argc, char *argv[]){
1024
1054
AvahiSServiceBrowser *sb = NULL;
1027
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intmax_t tmpmax;
1029
1059
int exitcode = EXIT_SUCCESS;
1030
const char *interface = "eth0";
1060
const char *interface = "";
1031
1061
struct ifreq network;
1033
1063
bool take_down_interface = false;
1036
char *connect_to = NULL;
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1066
char tempdir[] = "/tmp/mandosXXXXXX";
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1067
bool tempdir_created = false;
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1068
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
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.arg = "SECONDS",
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1132
.doc = "Maximum delay to wait for interface startup",
1106
* These reproduce what we would get without ARGP_NO_HELP
1108
{ .name = "help", .key = '?',
1109
.doc = "Give this help list", .group = -1 },
1110
{ .name = "usage", .key = -3,
1111
.doc = "Give a short usage message", .group = -1 },
1112
{ .name = "version", .key = 'V',
1113
.doc = "Print program version", .group = -1 },
1114
1134
{ .name = NULL }
1117
1137
error_t parse_opt(int key, char *arg,
1118
1138
struct argp_state *state){
1121
1140
case 128: /* --debug */
1138
1157
tmpmax = strtoimax(arg, &tmp, 10);
1139
1158
if(errno != 0 or tmp == arg or *tmp != '\0'
1140
1159
or tmpmax != (typeof(mc.dh_bits))tmpmax){
1141
argp_error(state, "Bad number of DH bits");
1160
fprintf(stderr, "Bad number of DH bits\n");
1143
1163
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
1150
1170
delay = strtof(arg, &tmp);
1151
1171
if(errno != 0 or tmp == arg or *tmp != '\0'){
1152
argp_error(state, "Bad delay");
1172
fprintf(stderr, "Bad delay\n");
1156
* These reproduce what we would get without ARGP_NO_HELP
1158
case '?': /* --help */
1159
argp_state_help(state, state->out_stream,
1160
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
1161
& ~(unsigned int)ARGP_HELP_EXIT_OK);
1162
case -3: /* --usage */
1163
argp_state_help(state, state->out_stream,
1164
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
1165
case 'V': /* --version */
1166
fprintf(state->out_stream, "%s\n", argp_program_version);
1167
exit(argp_err_exit_status);
1170
1181
return ARGP_ERR_UNKNOWN;
1175
1186
struct argp argp = { .options = options, .parser = parse_opt,
1176
1187
.args_doc = "",
1177
1188
.doc = "Mandos client -- Get and decrypt"
1178
1189
" passwords from a Mandos server" };
1179
ret = argp_parse(&argp, argc, argv,
1180
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
1187
perror("argp_parse");
1188
exitcode = EX_OSERR;
1191
exitcode = EX_USAGE;
1190
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
1191
if(ret == ARGP_ERR_UNKNOWN){
1192
fprintf(stderr, "Unknown error while parsing arguments\n");
1193
exitcode = EXIT_FAILURE;
1197
1199
avahi_set_log_function(empty_log);
1202
if(interface[0] == '\0'){
1203
struct dirent **direntries;
1204
ret = scandir(sys_class_net, &direntries, good_interface,
1207
/* Pick the first good interface */
1208
interface = strdup(direntries[0]->d_name);
1209
if(interface == NULL){
1212
exitcode = EXIT_FAILURE;
1218
fprintf(stderr, "Could not find a network interface\n");
1219
exitcode = EXIT_FAILURE;
1200
1224
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
1201
1225
from the signal handler */
1204
1228
mc.simple_poll = avahi_simple_poll_new();
1205
1229
if(mc.simple_poll == NULL){
1206
1230
fprintf(stderr, "Avahi: Failed to create simple poll object.\n");
1207
exitcode = EX_UNAVAILABLE;
1231
exitcode = EXIT_FAILURE;
1212
1236
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1214
1238
perror("sigaddset");
1215
exitcode = EX_OSERR;
1239
exitcode = EXIT_FAILURE;
1218
1242
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1220
1244
perror("sigaddset");
1221
exitcode = EX_OSERR;
1245
exitcode = EXIT_FAILURE;
1224
1248
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1226
1250
perror("sigaddset");
1227
exitcode = EX_OSERR;
1251
exitcode = EXIT_FAILURE;
1230
1254
/* Need to check if the handler is SIG_IGN before handling:
1234
1258
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1236
1260
perror("sigaction");
1261
return EXIT_FAILURE;
1239
1263
if(old_sigterm_action.sa_handler != SIG_IGN){
1240
1264
ret = sigaction(SIGINT, &sigterm_action, NULL);
1242
1266
perror("sigaction");
1243
exitcode = EX_OSERR;
1267
exitcode = EXIT_FAILURE;
1247
1271
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1249
1273
perror("sigaction");
1274
return EXIT_FAILURE;
1252
1276
if(old_sigterm_action.sa_handler != SIG_IGN){
1253
1277
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1255
1279
perror("sigaction");
1256
exitcode = EX_OSERR;
1280
exitcode = EXIT_FAILURE;
1260
1284
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1262
1286
perror("sigaction");
1287
return EXIT_FAILURE;
1265
1289
if(old_sigterm_action.sa_handler != SIG_IGN){
1266
1290
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1268
1292
perror("sigaction");
1269
exitcode = EX_OSERR;
1293
exitcode = EXIT_FAILURE;
1274
1298
/* If the interface is down, bring it up */
1275
if(interface[0] != '\0'){
1299
if(strcmp(interface, "none") != 0){
1276
1300
if_index = (AvahiIfIndex) if_nametoindex(interface);
1277
1301
if(if_index == 0){
1278
1302
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1279
exitcode = EX_UNAVAILABLE;
1303
exitcode = EXIT_FAILURE;
1294
1318
#ifdef __linux__
1295
1319
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1296
messages about the network interface to mess up the prompt */
1320
messages to mess up the prompt */
1297
1321
ret = klogctl(8, NULL, 5);
1298
1322
bool restore_loglevel = true;
1422
1446
ret = init_gnutls_global(pubkey, seckey);
1424
1448
fprintf(stderr, "init_gnutls_global failed\n");
1425
exitcode = EX_UNAVAILABLE;
1449
exitcode = EXIT_FAILURE;
1428
1452
gnutls_initialized = true;
1446
1470
if(not init_gpgme(pubkey, seckey, tempdir)){
1447
1471
fprintf(stderr, "init_gpgme failed\n");
1448
exitcode = EX_UNAVAILABLE;
1472
exitcode = EXIT_FAILURE;
1451
1475
gpgme_initialized = true;
1622
1628
perror("ioctl SIOCGIFFLAGS");
1623
1629
} else if(network.ifr_flags & IFF_UP) {
1624
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1630
network.ifr_flags &= ~IFF_UP; /* clear flag */
1625
1631
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1627
1633
perror("ioctl SIOCSIFFLAGS");