1218
* This function determines if a network interface is up.
1220
bool interface_is_up(const char *interface){
1222
if(not get_flags(interface, &ifr)){
1224
fprintf_plus(stderr, "Failed to get flags for interface "
1225
"\"%s\"\n", interface);
1230
return (bool)(ifr.ifr_flags & IFF_UP);
1234
* This function determines if a network interface is running
1236
bool interface_is_running(const char *interface){
1238
if(not get_flags(interface, &ifr)){
1240
fprintf_plus(stderr, "Failed to get flags for interface "
1241
"\"%s\"\n", interface);
1246
return (bool)(ifr.ifr_flags & IFF_RUNNING);
1202
* This function determines if a directory entry in /sys/class/net
1203
* corresponds to an acceptable network device which is up.
1204
* (This function is passed to scandir(3) as a filter function.)
1206
int up_interface(const struct dirent *if_entry){
1207
if(if_entry->d_name[0] == '.'){
1212
if(not get_flags(if_entry->d_name, &ifr)){
1214
fprintf_plus(stderr, "Failed to get flags for interface "
1215
"\"%s\"\n", if_entry->d_name);
1220
/* Reject down interfaces */
1221
if(not (ifr.ifr_flags & IFF_UP)){
1223
fprintf_plus(stderr, "Rejecting down interface \"%s\"\n",
1229
/* Reject non-running interfaces */
1230
if(not (ifr.ifr_flags & IFF_RUNNING)){
1232
fprintf_plus(stderr, "Rejecting non-running interface \"%s\"\n",
1238
if(not good_flags(if_entry->d_name, &ifr)){
1249
1244
int notdotentries(const struct dirent *direntry){
1393
/* Set effective uid to 0, return errno */
1394
error_t raise_privileges(void){
1395
error_t old_errno = errno;
1396
error_t ret_errno = 0;
1397
if(seteuid(0) == -1){
1399
perror_plus("seteuid");
1405
/* Set effective and real user ID to 0. Return errno. */
1406
error_t raise_privileges_permanently(void){
1407
error_t old_errno = errno;
1408
error_t ret_errno = raise_privileges();
1413
if(setuid(0) == -1){
1415
perror_plus("seteuid");
1421
/* Set effective user ID to unprivileged saved user ID */
1422
error_t lower_privileges(void){
1423
error_t old_errno = errno;
1424
error_t ret_errno = 0;
1425
if(seteuid(uid) == -1){
1427
perror_plus("seteuid");
1433
/* Lower privileges permanently */
1434
error_t lower_privileges_permanently(void){
1435
error_t old_errno = errno;
1436
error_t ret_errno = 0;
1437
if(setuid(uid) == -1){
1439
perror_plus("setuid");
1445
1388
bool run_network_hooks(const char *mode, const char *interface,
1446
1389
const float delay){
1447
1390
struct dirent **direntries;
1571
error_t bring_up_interface(const char *const interface,
1574
error_t old_errno = errno;
1575
error_t ret_errno = 0;
1576
int ret, ret_setflags;
1577
struct ifreq network;
1578
unsigned int if_index = if_nametoindex(interface);
1580
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1590
if(not interface_is_up(interface)){
1591
if(not get_flags(interface, &network) and debug){
1593
fprintf_plus(stderr, "Failed to get flags for interface "
1594
"\"%s\"\n", interface);
1597
network.ifr_flags |= IFF_UP;
1599
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1602
perror_plus("socket");
1614
fprintf_plus(stderr, "Bringing up interface \"%s\"\n",
1618
/* Raise priviliges */
1622
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1623
messages about the network interface to mess up the prompt */
1624
int ret_linux = klogctl(8, NULL, 5);
1625
bool restore_loglevel = true;
1626
if(ret_linux == -1){
1627
restore_loglevel = false;
1628
perror_plus("klogctl");
1630
#endif /* __linux__ */
1631
ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1634
if(restore_loglevel){
1635
ret_linux = klogctl(7, NULL, 0);
1636
if(ret_linux == -1){
1637
perror_plus("klogctl");
1640
#endif /* __linux__ */
1642
/* Lower privileges */
1645
/* Close the socket */
1646
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1648
perror_plus("close");
1651
if(ret_setflags == -1){
1653
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1658
fprintf_plus(stderr, "Interface \"%s\" is already up; good\n",
1662
/* Sleep checking until interface is running.
1663
Check every 0.25s, up to total time of delay */
1664
for(int i=0; i < delay * 4; i++){
1665
if(interface_is_running(interface)){
1668
struct timespec sleeptime = { .tv_nsec = 250000000 };
1669
ret = nanosleep(&sleeptime, NULL);
1670
if(ret == -1 and errno != EINTR){
1671
perror_plus("nanosleep");
1679
error_t take_down_interface(const char *const interface){
1681
error_t old_errno = errno;
1682
error_t ret_errno = 0;
1683
int ret, ret_setflags;
1684
struct ifreq network;
1685
unsigned int if_index = if_nametoindex(interface);
1687
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1691
if(interface_is_up(interface)){
1692
if(not get_flags(interface, &network) and debug){
1694
fprintf_plus(stderr, "Failed to get flags for interface "
1695
"\"%s\"\n", interface);
1698
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1700
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1703
perror_plus("socket");
1709
fprintf_plus(stderr, "Taking down interface \"%s\"\n",
1713
/* Raise priviliges */
1716
ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1719
/* Lower privileges */
1722
/* Close the socket */
1723
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1725
perror_plus("close");
1728
if(ret_setflags == -1){
1730
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
1735
fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",
1743
1517
int main(int argc, char *argv[]){
1744
1518
AvahiSServiceBrowser *sb = NULL;
1747
1521
intmax_t tmpmax;
1749
1523
int exitcode = EXIT_SUCCESS;
1750
char *interfaces = NULL;
1751
size_t interfaces_size = 0;
1752
char *interfaces_to_take_down = NULL;
1753
size_t interfaces_to_take_down_size = 0;
1524
const char *interface = "";
1525
struct ifreq network;
1527
bool take_down_interface = false;
1754
1530
char tempdir[] = "/tmp/mandosXXXXXX";
1755
1531
bool tempdir_created = false;
1756
1532
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
1757
1533
const char *seckey = PATHDIR "/" SECKEY;
1758
1534
const char *pubkey = PATHDIR "/" PUBKEY;
1759
char *interfaces_hooks = NULL;
1760
size_t interfaces_hooks_size = 0;
1762
1536
bool gnutls_initialized = false;
1763
1537
bool gpgme_initialized = false;
1999
/* Remove empty interface names */
2001
char *interface = NULL;
2002
while((interface = argz_next(interfaces, interfaces_size,
2004
if(if_nametoindex(interface) == 0){
2005
if(interface[0] != '\0' and strcmp(interface, "none") != 0){
2006
fprintf_plus(stderr, "Not using nonexisting interface"
2007
" \"%s\"\n", interface);
2009
argz_delete(&interfaces, &interfaces_size, interface);
2015
1773
/* Run network hooks */
2017
ret_errno = argz_append(&interfaces_hooks, &interfaces_hooks_size,
2018
interfaces, interfaces_size);
2021
perror_plus("argz_append");
2024
argz_stringify(interfaces_hooks, interfaces_hooks_size, (int)',');
2025
if(not run_network_hooks("start", interfaces_hooks, delay)){
1774
if(not run_network_hooks("start", interface, delay)){
2031
1779
avahi_set_log_function(empty_log);
1782
if(interface[0] == '\0'){
1783
struct dirent **direntries;
1784
/* First look for interfaces that are up */
1785
ret = scandir(sys_class_net, &direntries, up_interface,
1788
/* No up interfaces, look for any good interfaces */
1790
ret = scandir(sys_class_net, &direntries, good_interface,
1794
/* Pick the first interface returned */
1795
interface = strdup(direntries[0]->d_name);
1797
fprintf_plus(stderr, "Using interface \"%s\"\n", interface);
1799
if(interface == NULL){
1800
perror_plus("malloc");
1802
exitcode = EXIT_FAILURE;
1808
fprintf_plus(stderr, "Could not find a network interface\n");
1809
exitcode = EXIT_FAILURE;
2034
1814
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
2035
1815
from the signal handler */
2036
1816
/* Initialize the pseudo-RNG for Avahi */
2109
/* If no interfaces were specified, make a list */
2110
if(interfaces == NULL){
2111
struct dirent **direntries;
2112
/* Look for any good interfaces */
2113
ret = scandir(sys_class_net, &direntries, good_interface,
2116
/* Add all found interfaces to interfaces list */
2117
for(int i = 0; i < ret; ++i){
2118
ret_errno = argz_add(&interfaces, &interfaces_size,
2119
direntries[i]->d_name);
2121
perror_plus("argz_add");
2125
fprintf_plus(stderr, "Will use interface \"%s\"\n",
2126
direntries[i]->d_name);
2132
fprintf_plus(stderr, "Could not find a network interface\n");
2133
exitcode = EXIT_FAILURE;
2138
/* If we only got one interface, explicitly use only that one */
2139
if(argz_count(interfaces, interfaces_size) == 1){
2141
fprintf_plus(stderr, "Using only interface \"%s\"\n",
2144
if_index = (AvahiIfIndex)if_nametoindex(interfaces);
2147
/* Bring up interfaces which are down */
2148
if(not (argz_count(interfaces, interfaces_size) == 1
2149
and strcmp(interfaces, "none") == 0)){
2150
char *interface = NULL;
2151
while((interface = argz_next(interfaces, interfaces_size,
2153
bool interface_was_up = interface_is_up(interface);
2154
ret = bring_up_interface(interface, delay);
2155
if(not interface_was_up){
2158
perror_plus("Failed to bring up interface");
2160
ret_errno = argz_add(&interfaces_to_take_down,
2161
&interfaces_to_take_down_size,
2168
interfaces_size = 0;
2169
if(debug and (interfaces_to_take_down == NULL)){
2170
fprintf_plus(stderr, "No interfaces were brought up\n");
1889
/* If the interface is down, bring it up */
1890
if(strcmp(interface, "none") != 0){
1891
if_index = (AvahiIfIndex) if_nametoindex(interface);
1893
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1894
exitcode = EX_UNAVAILABLE;
1902
/* Re-raise priviliges */
1906
perror_plus("seteuid");
1910
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1911
messages about the network interface to mess up the prompt */
1912
ret = klogctl(8, NULL, 5);
1913
bool restore_loglevel = true;
1915
restore_loglevel = false;
1916
perror_plus("klogctl");
1918
#endif /* __linux__ */
1920
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1922
perror_plus("socket");
1923
exitcode = EX_OSERR;
1925
if(restore_loglevel){
1926
ret = klogctl(7, NULL, 0);
1928
perror_plus("klogctl");
1931
#endif /* __linux__ */
1932
/* Lower privileges */
1936
perror_plus("seteuid");
1940
strcpy(network.ifr_name, interface);
1941
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1943
perror_plus("ioctl SIOCGIFFLAGS");
1945
if(restore_loglevel){
1946
ret = klogctl(7, NULL, 0);
1948
perror_plus("klogctl");
1951
#endif /* __linux__ */
1952
exitcode = EX_OSERR;
1953
/* Lower privileges */
1957
perror_plus("seteuid");
1961
if((network.ifr_flags & IFF_UP) == 0){
1962
network.ifr_flags |= IFF_UP;
1963
take_down_interface = true;
1964
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1966
take_down_interface = false;
1967
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1968
exitcode = EX_OSERR;
1970
if(restore_loglevel){
1971
ret = klogctl(7, NULL, 0);
1973
perror_plus("klogctl");
1976
#endif /* __linux__ */
1977
/* Lower privileges */
1981
perror_plus("seteuid");
1986
/* Sleep checking until interface is running.
1987
Check every 0.25s, up to total time of delay */
1988
for(int i=0; i < delay * 4; i++){
1989
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1991
perror_plus("ioctl SIOCGIFFLAGS");
1992
} else if(network.ifr_flags & IFF_RUNNING){
1995
struct timespec sleeptime = { .tv_nsec = 250000000 };
1996
ret = nanosleep(&sleeptime, NULL);
1997
if(ret == -1 and errno != EINTR){
1998
perror_plus("nanosleep");
2001
if(not take_down_interface){
2002
/* We won't need the socket anymore */
2003
ret = (int)TEMP_FAILURE_RETRY(close(sd));
2005
perror_plus("close");
2009
if(restore_loglevel){
2010
/* Restores kernel loglevel to default */
2011
ret = klogctl(7, NULL, 0);
2013
perror_plus("klogctl");
2016
#endif /* __linux__ */
2017
/* Lower privileges */
2019
/* Lower privileges */
2022
perror_plus("seteuid");
2232
/* Run network hooks */
2233
run_network_hooks("stop", interface, delay);
2381
2235
/* Re-raise priviliges */
2385
/* Run network hooks */
2386
run_network_hooks("stop", interfaces_hooks, delay);
2388
/* Take down the network interfaces which were brought up */
2390
char *interface = NULL;
2391
while((interface=argz_next(interfaces_to_take_down,
2392
interfaces_to_take_down_size,
2394
ret_errno = take_down_interface(interface);
2397
perror_plus("Failed to take down interface");
2240
perror_plus("seteuid");
2243
/* Take down the network interface */
2244
if(take_down_interface and geteuid() == 0){
2245
ret = ioctl(sd, SIOCGIFFLAGS, &network);
2247
perror_plus("ioctl SIOCGIFFLAGS");
2248
} else if(network.ifr_flags & IFF_UP){
2249
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
2250
ret = ioctl(sd, SIOCSIFFLAGS, &network);
2252
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
2400
if(debug and (interfaces_to_take_down == NULL)){
2401
fprintf_plus(stderr, "No interfaces needed to be taken"
2255
ret = (int)TEMP_FAILURE_RETRY(close(sd));
2257
perror_plus("close");
2406
lower_privileges_permanently();
2409
free(interfaces_to_take_down);
2410
free(interfaces_hooks);
2261
/* Lower privileges permanently */
2265
perror_plus("setuid");
2412
2268
/* Removes the GPGME temp directory and all files inside */
2413
2269
if(tempdir_created){