/mandos/trunk : revision 594.1.2

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#include <stdio.h> /* fprintf(), stderr, fwrite(),

43

stdout, ferror(), remove() */

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#include <stdint.h> /* uint16_t, uint32_t */

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#include <stdint.h> /* uint16_t, uint32_t, intptr_t */

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#include <stddef.h> /* NULL, size_t, ssize_t */

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#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),

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strtof(), abort() */

135

static const char sys_class_net[] = "/sys/class/net";

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char *connect_to = NULL;

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const char *hookdir = HOOKDIR;

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uid_t uid = 65534;

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gid_t gid = 65534;

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/* Doubly linked list that need to be circularly linked when used */

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typedef struct server{

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goto mandos_end;

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}

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/* Spurious warning from -Wint-to-pointer-cast */

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gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

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/* This casting via intptr_t is to eliminate warning about casting

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an int to a pointer type. This is exactly how the GnuTLS Guile

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function "set-session-transport-fd!" does it. */

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gnutls_transport_set_ptr(session,

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(gnutls_transport_ptr_t)(intptr_t)tcp_sd);

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831

827

832

if(quit_now){

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errno = EINTR;

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}

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}

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/* Set effective uid to 0, return errno */

1396

int raise_privileges(void){

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int old_errno = errno;

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int ret_errno = 0;

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errno = 0;

1400

if(seteuid(0) == -1){

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perror_plus("seteuid");

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}

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ret_errno = errno;

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errno = old_errno;

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return ret_errno;

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}

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/* Set effective and real user ID to 0. Return errno. */

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int raise_privileges_permanently(void){

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int old_errno = errno;

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int ret_errno = raise_privileges();

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if(ret_errno != 0){

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errno = old_errno;

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return ret_errno;

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}

1416

errno = 0;

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if(setuid(0) == -1){

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perror_plus("seteuid");

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}

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ret_errno = errno;

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errno = old_errno;

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return ret_errno;

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}

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/* Set effective user ID to unprivileged saved user ID */

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int lower_privileges(void){

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int old_errno = errno;

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int ret_errno = 0;

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errno = 0;

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if(seteuid(uid) == -1){

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perror_plus("seteuid");

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}

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ret_errno = errno;

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errno = old_errno;

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return ret_errno;

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}

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bool run_network_hooks(const char *mode, const char *interface,

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1439

const float delay){

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struct dirent **direntries;

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if(hook_pid == 0){

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/* Child */

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/* Raise privileges */

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errno = 0;

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ret = seteuid(0);

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if(ret == -1){

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perror_plus("seteuid");

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}

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/* Raise privileges even more */

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errno = 0;

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ret = setuid(0);

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if(ret == -1){

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perror_plus("setuid");

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}

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raise_privileges_permanently();

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/* Set group */

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errno = 0;

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ret = setgid(0);

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return true;

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}

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int bring_up_interface(const char * const interface, const float delay){

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int sd = -1;

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int old_errno = errno;

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int ret_errno = 0;

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int ret;

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struct ifreq network;

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AvahiIfIndex if_index = (AvahiIfIndex)if_nametoindex(interface);

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if(if_index == 0){

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fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);

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errno = old_errno;

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return ENXIO;

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}

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if(quit_now){

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errno = old_errno;

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return EINTR;

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}

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/* Re-raise priviliges */

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raise_privileges();

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#ifdef __linux__

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/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

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messages about the network interface to mess up the prompt */

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ret = klogctl(8, NULL, 5);

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bool restore_loglevel = true;

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if(ret == -1){

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restore_loglevel = false;

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perror_plus("klogctl");

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}

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#endif /* __linux__ */

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sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

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if(sd < 0){

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ret_errno = errno;

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perror_plus("socket");

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#ifdef __linux__

1601

if(restore_loglevel){

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ret = klogctl(7, NULL, 0);

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if(ret == -1){

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perror_plus("klogctl");

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}

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}

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#endif /* __linux__ */

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/* Lower privileges */

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lower_privileges();

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errno = old_errno;

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return ret_errno;

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}

1613

strcpy(network.ifr_name, interface);

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ret = ioctl(sd, SIOCGIFFLAGS, &network);

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if(ret == -1){

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ret_errno = errno;

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perror_plus("ioctl SIOCGIFFLAGS");

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#ifdef __linux__

1619

if(restore_loglevel){

1620

ret = klogctl(7, NULL, 0);

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if(ret == -1){

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perror_plus("klogctl");

1623

}

1624

}

1625

#endif /* __linux__ */

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/* Lower privileges */

1627

lower_privileges();

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errno = old_errno;

1629

return ret_errno;

1630

}

1631

if((network.ifr_flags & IFF_UP) == 0){

1632

network.ifr_flags |= IFF_UP;

1633

ret = ioctl(sd, SIOCSIFFLAGS, &network);

1634

if(ret == -1){

1635

ret_errno = errno;

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perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1637

#ifdef __linux__

1638

if(restore_loglevel){

1639

ret = klogctl(7, NULL, 0);

1640

if(ret == -1){

1641

perror_plus("klogctl");

1642

}

1643

}

1644

#endif /* __linux__ */

1645

/* Lower privileges */

1646

lower_privileges();

1647

errno = old_errno;

1648

return ret_errno;

1649

}

1650

}

1651

/* Sleep checking until interface is running.

1652

Check every 0.25s, up to total time of delay */

1653

for(int i=0; i < delay * 4; i++){

1654

ret = ioctl(sd, SIOCGIFFLAGS, &network);

1655

if(ret == -1){

1656

perror_plus("ioctl SIOCGIFFLAGS");

1657

} else if(network.ifr_flags & IFF_RUNNING){

1658

break;

1659

}

1660

struct timespec sleeptime = { .tv_nsec = 250000000 };

1661

ret = nanosleep(&sleeptime, NULL);

1662

if(ret == -1 and errno != EINTR){

1663

perror_plus("nanosleep");

1664

}

1665

}

1666

/* Close the socket */

1667

ret = (int)TEMP_FAILURE_RETRY(close(sd));

1668

if(ret == -1){

1669

perror_plus("close");

1670

}

1671

#ifdef __linux__

1672

if(restore_loglevel){

1673

/* Restores kernel loglevel to default */

1674

ret = klogctl(7, NULL, 0);

1675

if(ret == -1){

1676

perror_plus("klogctl");

1677

}

1678

}

1679

#endif /* __linux__ */

1680

/* Lower privileges */

1681

lower_privileges();

1682

errno = old_errno;

1683

return 0;

1684

}

1685

1526

1686

int main(int argc, char *argv[]){

1527

1687

AvahiSServiceBrowser *sb = NULL;

1528

1688

int error;

1534

1694

struct ifreq network;

1535

1695

int sd = -1;

1536

1696

bool take_down_interface = false;

1537

uid_t uid;

1538

gid_t gid;

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1697

char tempdir[] = "/tmp/mandosXXXXXX";

1540

1698

bool tempdir_created = false;

1541

1699

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

1721

1879

<http://bugs.debian.org/633582> */

1722

1880

1723

1881

/* Re-raise priviliges */

1724

errno = 0;

1725

ret = seteuid(0);

1726

if(ret == -1){

1727

perror_plus("seteuid");

1728

} else {

1882

if(raise_privileges() == 0){

1729

1883

struct stat st;

1730

1884

1731

1885

if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){

1896

2050

}

1897

2051

1898

2052

/* If the interface is down, bring it up */

1899

if(strcmp(interface, "none") != 0){

1900

if_index = (AvahiIfIndex) if_nametoindex(interface);

1901

if(if_index == 0){

1902

fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);

1903

exitcode = EX_UNAVAILABLE;

1904

goto end;

1905

}

1906

1907

if(quit_now){

1908

goto end;

1909

}

1910

1911

/* Re-raise priviliges */

1912

errno = 0;

1913

ret = seteuid(0);

1914

if(ret == -1){

1915

perror_plus("seteuid");

1916

}

1917

1918

#ifdef __linux__

1919

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1920

messages about the network interface to mess up the prompt */

1921

ret = klogctl(8, NULL, 5);

1922

bool restore_loglevel = true;

1923

if(ret == -1){

1924

restore_loglevel = false;

1925

perror_plus("klogctl");

1926

}

1927

#endif /* __linux__ */

1928

1929

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1930

if(sd < 0){

1931

perror_plus("socket");

1932

exitcode = EX_OSERR;

1933

#ifdef __linux__

1934

if(restore_loglevel){

1935

ret = klogctl(7, NULL, 0);

1936

if(ret == -1){

1937

perror_plus("klogctl");

1938

}

1939

}

1940

#endif /* __linux__ */

1941

/* Lower privileges */

1942

errno = 0;

1943

ret = seteuid(uid);

1944

if(ret == -1){

1945

perror_plus("seteuid");

1946

}

1947

goto end;

1948

}

1949

strcpy(network.ifr_name, interface);

1950

ret = ioctl(sd, SIOCGIFFLAGS, &network);

1951

if(ret == -1){

1952

perror_plus("ioctl SIOCGIFFLAGS");

1953

#ifdef __linux__

1954

if(restore_loglevel){

1955

ret = klogctl(7, NULL, 0);

1956

if(ret == -1){

1957

perror_plus("klogctl");

1958

}

1959

}

1960

#endif /* __linux__ */

1961

exitcode = EX_OSERR;

1962

/* Lower privileges */

1963

errno = 0;

1964

ret = seteuid(uid);

1965

if(ret == -1){

1966

perror_plus("seteuid");

1967

}

1968

goto end;

1969

}

1970

if((network.ifr_flags & IFF_UP) == 0){

1971

network.ifr_flags |= IFF_UP;

1972

take_down_interface = true;

1973

ret = ioctl(sd, SIOCSIFFLAGS, &network);

1974

if(ret == -1){

1975

take_down_interface = false;

1976

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1977

exitcode = EX_OSERR;

1978

#ifdef __linux__

1979

if(restore_loglevel){

1980

ret = klogctl(7, NULL, 0);

1981

if(ret == -1){

1982

perror_plus("klogctl");

1983

}

1984

}

1985

#endif /* __linux__ */

1986

/* Lower privileges */

1987

errno = 0;

1988

ret = seteuid(uid);

1989

if(ret == -1){

1990

perror_plus("seteuid");

1991

}

1992

goto end;

1993

}

1994

}

1995

/* Sleep checking until interface is running.

1996

Check every 0.25s, up to total time of delay */

1997

for(int i=0; i < delay * 4; i++){

1998

ret = ioctl(sd, SIOCGIFFLAGS, &network);

1999

if(ret == -1){

2000

perror_plus("ioctl SIOCGIFFLAGS");

2001

} else if(network.ifr_flags & IFF_RUNNING){

2002

break;

2003

}

2004

struct timespec sleeptime = { .tv_nsec = 250000000 };

2005

ret = nanosleep(&sleeptime, NULL);

2006

if(ret == -1 and errno != EINTR){

2007

perror_plus("nanosleep");

2008

}

2009

}

2010

if(not take_down_interface){

2011

/* We won't need the socket anymore */

2012

ret = (int)TEMP_FAILURE_RETRY(close(sd));

2013

if(ret == -1){

2014

perror_plus("close");

2015

}

2016

}

2017

#ifdef __linux__

2018

if(restore_loglevel){

2019

/* Restores kernel loglevel to default */

2020

ret = klogctl(7, NULL, 0);

2021

if(ret == -1){

2022

perror_plus("klogctl");

2023

}

2024

}

2025

#endif /* __linux__ */

2026

/* Lower privileges */

2027

errno = 0;

2028

/* Lower privileges */

2029

ret = seteuid(uid);

2030

if(ret == -1){

2031

perror_plus("seteuid");

2053

if((interface[0] != '\0') and (strcmp(interface, "none") != 0)){

2054

ret = bring_up_interface(interface, delay);

2055

if(ret != 0){

2056

errno = ret;

2057

perror_plus("Failed to bring up interface");

2032

2058

}

2033

2059

}

2034

2060

2075

2101

/* Connect directly, do not use Zeroconf */

2076

2102

/* (Mainly meant for debugging) */

2077

2103

char *address = strrchr(connect_to, ':');

2104

2078

2105

if(address == NULL){

2079

2106

fprintf_plus(stderr, "No colon in address\n");

2080

2107

exitcode = EX_USAGE;

2243

2270

2244

2271

/* Re-raise priviliges */

2245

2272

{

2246

errno = 0;

2247

ret = seteuid(0);

2248

if(ret == -1){

2249

perror_plus("seteuid");

2250

}

2273

raise_privileges();

2251

2274

2252

2275

/* Take down the network interface */

2253

2276

if(take_down_interface and geteuid() == 0){