1395
/* Set effective uid to 0, return errno */
1396
error_t raise_privileges(void){
1397
error_t old_errno = errno;
1398
error_t ret_errno = 0;
1399
if(seteuid(0) == -1){
1401
perror_plus("seteuid");
1407
/* Set effective and real user ID to 0. Return errno. */
1408
error_t raise_privileges_permanently(void){
1409
error_t old_errno = errno;
1410
error_t ret_errno = raise_privileges();
1415
if(setuid(0) == -1){
1417
perror_plus("seteuid");
1423
/* Set effective user ID to unprivileged saved user ID */
1424
error_t lower_privileges(void){
1425
error_t old_errno = errno;
1426
error_t ret_errno = 0;
1427
if(seteuid(uid) == -1){
1429
perror_plus("seteuid");
1435
1393
bool run_network_hooks(const char *mode, const char *interface,
1436
1394
const float delay){
1437
1395
struct dirent **direntries;
1561
int bring_up_interface(const char *const interface,
1564
int old_errno = errno;
1567
struct ifreq network;
1568
AvahiIfIndex if_index = (AvahiIfIndex)if_nametoindex(interface);
1570
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1580
/* Re-raise priviliges */
1584
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1585
messages about the network interface to mess up the prompt */
1586
ret = klogctl(8, NULL, 5);
1587
bool restore_loglevel = true;
1589
restore_loglevel = false;
1590
perror_plus("klogctl");
1592
#endif /* __linux__ */
1594
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1597
perror_plus("socket");
1599
if(restore_loglevel){
1600
ret = klogctl(7, NULL, 0);
1602
perror_plus("klogctl");
1605
#endif /* __linux__ */
1606
/* Lower privileges */
1611
strcpy(network.ifr_name, interface);
1612
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1615
perror_plus("ioctl SIOCGIFFLAGS");
1617
if(restore_loglevel){
1618
ret = klogctl(7, NULL, 0);
1620
perror_plus("klogctl");
1623
#endif /* __linux__ */
1624
/* Lower privileges */
1629
if((network.ifr_flags & IFF_UP) == 0){
1630
network.ifr_flags |= IFF_UP;
1631
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1634
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1636
if(restore_loglevel){
1637
ret = klogctl(7, NULL, 0);
1639
perror_plus("klogctl");
1642
#endif /* __linux__ */
1643
/* Lower privileges */
1649
/* Sleep checking until interface is running.
1650
Check every 0.25s, up to total time of delay */
1651
for(int i=0; i < delay * 4; i++){
1652
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1654
perror_plus("ioctl SIOCGIFFLAGS");
1655
} else if(network.ifr_flags & IFF_RUNNING){
1658
struct timespec sleeptime = { .tv_nsec = 250000000 };
1659
ret = nanosleep(&sleeptime, NULL);
1660
if(ret == -1 and errno != EINTR){
1661
perror_plus("nanosleep");
1664
/* Close the socket */
1665
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1667
perror_plus("close");
1670
if(restore_loglevel){
1671
/* Restores kernel loglevel to default */
1672
ret = klogctl(7, NULL, 0);
1674
perror_plus("klogctl");
1677
#endif /* __linux__ */
1678
/* Lower privileges */
1684
1529
int main(int argc, char *argv[]){
1685
1530
AvahiSServiceBrowser *sb = NULL;
2050
1901
/* If the interface is down, bring it up */
2051
if((interface[0] != '\0') and (strcmp(interface, "none") != 0)){
2052
ret = bring_up_interface(interface, delay);
2055
perror_plus("Failed to bring up interface");
1902
if(strcmp(interface, "none") != 0){
1903
if_index = (AvahiIfIndex) if_nametoindex(interface);
1905
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1906
exitcode = EX_UNAVAILABLE;
1914
/* Re-raise priviliges */
1918
perror_plus("seteuid");
1922
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1923
messages about the network interface to mess up the prompt */
1924
ret = klogctl(8, NULL, 5);
1925
bool restore_loglevel = true;
1927
restore_loglevel = false;
1928
perror_plus("klogctl");
1930
#endif /* __linux__ */
1932
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1934
perror_plus("socket");
1935
exitcode = EX_OSERR;
1937
if(restore_loglevel){
1938
ret = klogctl(7, NULL, 0);
1940
perror_plus("klogctl");
1943
#endif /* __linux__ */
1944
/* Lower privileges */
1948
perror_plus("seteuid");
1952
strcpy(network.ifr_name, interface);
1953
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1955
perror_plus("ioctl SIOCGIFFLAGS");
1957
if(restore_loglevel){
1958
ret = klogctl(7, NULL, 0);
1960
perror_plus("klogctl");
1963
#endif /* __linux__ */
1964
exitcode = EX_OSERR;
1965
/* Lower privileges */
1969
perror_plus("seteuid");
1973
if((network.ifr_flags & IFF_UP) == 0){
1974
network.ifr_flags |= IFF_UP;
1975
take_down_interface = true;
1976
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1978
take_down_interface = false;
1979
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1980
exitcode = EX_OSERR;
1982
if(restore_loglevel){
1983
ret = klogctl(7, NULL, 0);
1985
perror_plus("klogctl");
1988
#endif /* __linux__ */
1989
/* Lower privileges */
1993
perror_plus("seteuid");
1998
/* Sleep checking until interface is running.
1999
Check every 0.25s, up to total time of delay */
2000
for(int i=0; i < delay * 4; i++){
2001
ret = ioctl(sd, SIOCGIFFLAGS, &network);
2003
perror_plus("ioctl SIOCGIFFLAGS");
2004
} else if(network.ifr_flags & IFF_RUNNING){
2007
struct timespec sleeptime = { .tv_nsec = 250000000 };
2008
ret = nanosleep(&sleeptime, NULL);
2009
if(ret == -1 and errno != EINTR){
2010
perror_plus("nanosleep");
2013
if(not take_down_interface){
2014
/* We won't need the socket anymore */
2015
ret = (int)TEMP_FAILURE_RETRY(close(sd));
2017
perror_plus("close");
2021
if(restore_loglevel){
2022
/* Restores kernel loglevel to default */
2023
ret = klogctl(7, NULL, 0);
2025
perror_plus("klogctl");
2028
#endif /* __linux__ */
2029
/* Lower privileges */
2031
/* Lower privileges */
2034
perror_plus("seteuid");