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,
47
srand(), strtof(), abort() */
46
#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),
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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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82
#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 */
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#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,
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EX_NOHOST, EX_IOERR, EX_PROTOCOL */
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#include <sys/klog.h> /* klogctl() */
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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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const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
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static const char sys_class_net[] = "/sys/class/net";
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char *connect_to = NULL;
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133
/* Used for passing in values through the Avahi callback functions */
975
1022
errno = old_errno;
1026
* This function determines if a directory entry in /sys/class/net
1027
* corresponds to an acceptable network device.
1028
* (This function is passed to scandir(3) as a filter function.)
1030
int good_interface(const struct dirent *if_entry){
1032
char *flagname = NULL;
1033
int ret = asprintf(&flagname, "%s/%s/flags", sys_class_net,
1039
if(if_entry->d_name[0] == '.'){
1042
int flags_fd = (int)TEMP_FAILURE_RETRY(open(flagname, O_RDONLY));
1047
typedef short ifreq_flags; /* ifreq.ifr_flags in netdevice(7) */
1048
/* read line from flags_fd */
1049
ssize_t to_read = (sizeof(ifreq_flags)*2)+3; /* "0x1003\n" */
1050
char *flagstring = malloc((size_t)to_read+1); /* +1 for final \0 */
1051
flagstring[(size_t)to_read] = '\0';
1052
if(flagstring == NULL){
1058
ssret = (ssize_t)TEMP_FAILURE_RETRY(read(flags_fd, flagstring,
1075
tmpmax = strtoimax(flagstring, &tmp, 0);
1076
if(errno != 0 or tmp == flagstring or (*tmp != '\0'
1077
and not (isspace(*tmp)))
1078
or tmpmax != (ifreq_flags)tmpmax){
1080
fprintf(stderr, "Invalid flags \"%s\" for interface \"%s\"\n",
1081
flagstring, if_entry->d_name);
1087
ifreq_flags flags = (ifreq_flags)tmpmax;
1088
/* Reject the loopback device */
1089
if(flags & IFF_LOOPBACK){
1091
fprintf(stderr, "Rejecting loopback interface \"%s\"\n",
1096
/* Accept point-to-point devices only if connect_to is specified */
1097
if(connect_to != NULL and (flags & IFF_POINTOPOINT)){
1099
fprintf(stderr, "Accepting point-to-point interface \"%s\"\n",
1104
/* Otherwise, reject non-broadcast-capable devices */
1105
if(not (flags & IFF_BROADCAST)){
1107
fprintf(stderr, "Rejecting non-broadcast interface \"%s\"\n",
1112
/* Accept this device */
1114
fprintf(stderr, "Interface \"%s\" is acceptable\n",
978
1120
int main(int argc, char *argv[]){
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1121
AvahiSServiceBrowser *sb = NULL;
982
1124
intmax_t tmpmax;
984
1126
int exitcode = EXIT_SUCCESS;
985
const char *interface = "eth0";
1127
const char *interface = "";
986
1128
struct ifreq network;
988
1130
bool take_down_interface = false;
991
char *connect_to = NULL;
992
1133
char tempdir[] = "/tmp/mandosXXXXXX";
993
1134
bool tempdir_created = false;
994
1135
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
1152
1293
avahi_set_log_function(empty_log);
1296
if(interface[0] == '\0'){
1297
struct dirent **direntries;
1298
ret = scandir(sys_class_net, &direntries, good_interface,
1301
/* Pick the first good interface */
1302
interface = strdup(direntries[0]->d_name);
1304
fprintf(stderr, "Using interface \"%s\"\n", interface);
1306
if(interface == NULL){
1309
exitcode = EXIT_FAILURE;
1315
fprintf(stderr, "Could not find a network interface\n");
1316
exitcode = EXIT_FAILURE;
1155
1321
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
1156
1322
from the signal handler */
1167
1333
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1169
1335
perror("sigaddset");
1170
exitcode = EXIT_FAILURE;
1336
exitcode = EX_OSERR;
1173
1339
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1175
1341
perror("sigaddset");
1176
exitcode = EXIT_FAILURE;
1342
exitcode = EX_OSERR;
1179
1345
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1181
1347
perror("sigaddset");
1182
exitcode = EXIT_FAILURE;
1348
exitcode = EX_OSERR;
1185
1351
/* Need to check if the handler is SIG_IGN before handling:
1189
1355
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1191
1357
perror("sigaction");
1192
return EXIT_FAILURE;
1194
1360
if(old_sigterm_action.sa_handler != SIG_IGN){
1195
1361
ret = sigaction(SIGINT, &sigterm_action, NULL);
1197
1363
perror("sigaction");
1198
exitcode = EXIT_FAILURE;
1364
exitcode = EX_OSERR;
1202
1368
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1204
1370
perror("sigaction");
1205
return EXIT_FAILURE;
1207
1373
if(old_sigterm_action.sa_handler != SIG_IGN){
1208
1374
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1210
1376
perror("sigaction");
1211
exitcode = EXIT_FAILURE;
1377
exitcode = EX_OSERR;
1215
1381
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1217
1383
perror("sigaction");
1218
return EXIT_FAILURE;
1220
1386
if(old_sigterm_action.sa_handler != SIG_IGN){
1221
1387
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1223
1389
perror("sigaction");
1224
exitcode = EXIT_FAILURE;
1390
exitcode = EX_OSERR;
1229
1395
/* If the interface is down, bring it up */
1230
if(interface[0] != '\0'){
1396
if(strcmp(interface, "none") != 0){
1231
1397
if_index = (AvahiIfIndex) if_nametoindex(interface);
1232
1398
if(if_index == 0){
1233
1399
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1234
exitcode = EXIT_FAILURE;
1400
exitcode = EX_UNAVAILABLE;
1304
1470
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1306
1472
take_down_interface = false;
1307
perror("ioctl SIOCSIFFLAGS");
1308
exitcode = EXIT_FAILURE;
1473
perror("ioctl SIOCSIFFLAGS +IFF_UP");
1474
exitcode = EX_OSERR;
1309
1475
#ifdef __linux__
1310
1476
if(restore_loglevel){
1311
1477
ret = klogctl(7, NULL, 0);
1401
1567
if(not init_gpgme(pubkey, seckey, tempdir)){
1402
1568
fprintf(stderr, "init_gpgme failed\n");
1403
exitcode = EXIT_FAILURE;
1569
exitcode = EX_UNAVAILABLE;
1406
1572
gpgme_initialized = true;
1561
1745
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1562
1746
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1564
perror("ioctl SIOCSIFFLAGS");
1748
perror("ioctl SIOCSIFFLAGS -IFF_UP");
1567
1751
ret = (int)TEMP_FAILURE_RETRY(close(sd));