643
650
static void empty_log(__attribute__((unused)) AvahiLogLevel level,
644
651
__attribute__((unused)) const char *txt){}
653
/* Set effective uid to 0, return errno */
654
__attribute__((warn_unused_result))
655
error_t raise_privileges(void){
656
error_t old_errno = errno;
657
error_t ret_errno = 0;
658
if(seteuid(0) == -1){
665
/* Set effective and real user ID to 0. Return errno. */
666
__attribute__((warn_unused_result))
667
error_t raise_privileges_permanently(void){
668
error_t old_errno = errno;
669
error_t ret_errno = raise_privileges();
681
/* Set effective user ID to unprivileged saved user ID */
682
__attribute__((warn_unused_result))
683
error_t lower_privileges(void){
684
error_t old_errno = errno;
685
error_t ret_errno = 0;
686
if(seteuid(uid) == -1){
693
/* Lower privileges permanently */
694
__attribute__((warn_unused_result))
695
error_t lower_privileges_permanently(void){
696
error_t old_errno = errno;
697
error_t ret_errno = 0;
698
if(setuid(uid) == -1){
705
/* Helper function to add_local_route() and delete_local_route() */
706
__attribute__((nonnull, warn_unused_result))
707
static bool add_delete_local_route(const bool add,
709
AvahiIfIndex if_index){
711
char helper[] = "mandos-client-iprouteadddel";
712
char add_arg[] = "add";
713
char delete_arg[] = "delete";
714
char debug_flag[] = "--debug";
715
char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");
716
if(pluginhelperdir == NULL){
718
fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"
719
" variable not set; cannot run helper\n");
724
char interface[IF_NAMESIZE];
725
if(if_indextoname((unsigned int)if_index, interface) == NULL){
726
perror_plus("if_indextoname");
730
int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));
732
perror_plus("open(\"/dev/null\", O_RDONLY)");
738
/* Raise privileges */
739
errno = raise_privileges_permanently();
741
perror_plus("Failed to raise privileges");
742
/* _exit(EX_NOPERM); */
748
perror_plus("setgid");
751
/* Reset supplementary groups */
753
ret = setgroups(0, NULL);
755
perror_plus("setgroups");
759
ret = dup2(devnull, STDIN_FILENO);
761
perror_plus("dup2(devnull, STDIN_FILENO)");
764
ret = (int)TEMP_FAILURE_RETRY(close(devnull));
766
perror_plus("close");
769
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
771
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
774
int helperdir_fd = (int)TEMP_FAILURE_RETRY(open(pluginhelperdir,
779
if(helperdir_fd == -1){
781
_exit(EX_UNAVAILABLE);
783
int helper_fd = (int)TEMP_FAILURE_RETRY(openat(helperdir_fd,
786
perror_plus("openat");
787
_exit(EX_UNAVAILABLE);
789
TEMP_FAILURE_RETRY(close(helperdir_fd));
791
#pragma GCC diagnostic push
792
#pragma GCC diagnostic ignored "-Wcast-qual"
794
if(fexecve(helper_fd, (char *const [])
795
{ helper, add ? add_arg : delete_arg, (char *)address,
796
interface, debug ? debug_flag : NULL, NULL },
799
#pragma GCC diagnostic pop
801
perror_plus("fexecve");
813
pret = waitpid(pid, &status, 0);
814
if(pret == -1 and errno == EINTR and quit_now){
815
int errno_raising = 0;
816
if((errno = raise_privileges()) != 0){
817
errno_raising = errno;
818
perror_plus("Failed to raise privileges in order to"
819
" kill helper program");
821
if(kill(pid, SIGTERM) == -1){
824
if((errno_raising == 0) and (errno = lower_privileges()) != 0){
825
perror_plus("Failed to lower privileges after killing"
830
} while(pret == -1 and errno == EINTR);
832
perror_plus("waitpid");
835
if(WIFEXITED(status)){
836
if(WEXITSTATUS(status) != 0){
837
fprintf_plus(stderr, "Error: iprouteadddel exited"
838
" with status %d\n", WEXITSTATUS(status));
843
if(WIFSIGNALED(status)){
844
fprintf_plus(stderr, "Error: iprouteadddel died by"
845
" signal %d\n", WTERMSIG(status));
848
fprintf_plus(stderr, "Error: iprouteadddel crashed\n");
852
__attribute__((nonnull, warn_unused_result))
853
static bool add_local_route(const char *address,
854
AvahiIfIndex if_index){
856
fprintf_plus(stderr, "Adding route to %s\n", address);
858
return add_delete_local_route(true, address, if_index);
861
__attribute__((nonnull, warn_unused_result))
862
static bool delete_local_route(const char *address,
863
AvahiIfIndex if_index){
865
fprintf_plus(stderr, "Removing route to %s\n", address);
867
return add_delete_local_route(false, address, if_index);
646
870
/* Called when a Mandos server is found */
647
871
__attribute__((nonnull, warn_unused_result))
648
872
static int start_mandos_communication(const char *ip, in_port_t port,
817
1042
goto mandos_end;
821
ret = connect(tcp_sd, (struct sockaddr *)&to,
822
sizeof(struct sockaddr_in6));
824
ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */
825
sizeof(struct sockaddr_in));
828
if((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){
830
perror_plus("connect");
1047
ret = connect(tcp_sd, (struct sockaddr *)&to,
1048
sizeof(struct sockaddr_in6));
1050
ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */
1051
sizeof(struct sockaddr_in));
1054
if(errno == ENETUNREACH
1055
and if_index != AVAHI_IF_UNSPEC
1056
and connect_to == NULL
1057
and not route_added and
1058
((af == AF_INET6 and not
1059
IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)
1061
or (af == AF_INET and
1062
/* Not a a IPv4LL address */
1063
(ntohl(((struct sockaddr_in *)&to)->sin_addr.s_addr)
1064
& 0xFFFF0000L) != 0xA9FE0000L))){
1065
/* Work around Avahi bug - Avahi does not announce link-local
1066
addresses if it has a global address, so local hosts with
1067
*only* a link-local address (e.g. Mandos clients) cannot
1068
connect to a Mandos server announced by Avahi on a server
1069
host with a global address. Work around this by retrying
1070
with an explicit route added with the server's address.
1072
Avahi bug reference:
1073
http://lists.freedesktop.org/archives/avahi/2010-February/001833.html
1074
https://bugs.debian.org/587961
1077
fprintf_plus(stderr, "Mandos server unreachable, trying"
1081
route_added = add_local_route(ip, if_index);
1087
if(errno != ECONNREFUSED or debug){
1089
perror_plus("connect");
841
1102
const char *out = mandos_protocol_version;
1457
/* Set effective uid to 0, return errno */
1458
__attribute__((warn_unused_result))
1459
error_t raise_privileges(void){
1460
error_t old_errno = errno;
1461
error_t ret_errno = 0;
1462
if(seteuid(0) == -1){
1469
/* Set effective and real user ID to 0. Return errno. */
1470
__attribute__((warn_unused_result))
1471
error_t raise_privileges_permanently(void){
1472
error_t old_errno = errno;
1473
error_t ret_errno = raise_privileges();
1478
if(setuid(0) == -1){
1485
/* Set effective user ID to unprivileged saved user ID */
1486
__attribute__((warn_unused_result))
1487
error_t lower_privileges(void){
1488
error_t old_errno = errno;
1489
error_t ret_errno = 0;
1490
if(seteuid(uid) == -1){
1497
/* Lower privileges permanently */
1498
__attribute__((warn_unused_result))
1499
error_t lower_privileges_permanently(void){
1500
error_t old_errno = errno;
1501
error_t ret_errno = 0;
1502
if(setuid(uid) == -1){
1509
1725
__attribute__((nonnull))
1510
1726
void run_network_hooks(const char *mode, const char *interface,
1511
1727
const float delay){
1512
1728
struct dirent **direntries = NULL;
1513
1729
if(hookdir_fd == -1){
1514
hookdir_fd = open(hookdir, O_RDONLY);
1730
hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH
1515
1732
if(hookdir_fd == -1){
1516
1733
if(errno == ENOENT){