32
32
/* Needed by GPGME, specifically gpgme_data_seek() */
33
33
#ifndef _LARGEFILE_SOURCE
34
34
#define _LARGEFILE_SOURCE
35
#endif /* not _LARGEFILE_SOURCE */
36
36
#ifndef _FILE_OFFSET_BITS
37
37
#define _FILE_OFFSET_BITS 64
38
#endif /* not _FILE_OFFSET_BITS */
40
40
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
42
42
#include <stdio.h> /* fprintf(), stderr, fwrite(),
43
stdout, ferror(), remove() */
44
44
#include <stdint.h> /* uint16_t, uint32_t, intptr_t */
45
45
#include <stddef.h> /* NULL, size_t, ssize_t */
46
46
#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),
47
47
strtof(), abort() */
48
48
#include <stdbool.h> /* bool, false, true */
49
#include <string.h> /* strcmp(), strlen(), strerror(),
50
asprintf(), strncpy() */
49
#include <string.h> /* memset(), strcmp(), strlen(),
50
strerror(), asprintf(), strcpy() */
51
51
#include <sys/ioctl.h> /* ioctl */
52
52
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
53
53
sockaddr_in6, PF_INET6,
57
57
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
58
58
inet_pton(), connect(),
60
#include <fcntl.h> /* open(), unlinkat(), AT_REMOVEDIR */
60
#include <fcntl.h> /* open() */
61
61
#include <dirent.h> /* opendir(), struct dirent, readdir()
63
63
#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,
65
#include <errno.h> /* perror(), errno, EINTR, EINVAL,
66
EAI_SYSTEM, ENETUNREACH,
67
EHOSTUNREACH, ECONNREFUSED, EPROTO,
68
EIO, ENOENT, ENXIO, ENOMEM, EISDIR,
65
#include <errno.h> /* perror(), errno,
70
66
program_invocation_short_name */
71
67
#include <time.h> /* nanosleep(), time(), sleep() */
72
68
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
572
557
safer_gnutls_strerror(ret));
575
/* If a Diffie-Hellman parameters file was given, try to use it */
576
if(dhparamsfilename != NULL){
577
gnutls_datum_t params = { .data = NULL, .size = 0 };
579
int dhpfile = open(dhparamsfilename, O_RDONLY);
582
dhparamsfilename = NULL;
585
size_t params_capacity = 0;
587
params_capacity = incbuffer((char **)¶ms.data,
589
(size_t)params_capacity);
590
if(params_capacity == 0){
591
perror_plus("incbuffer");
594
dhparamsfilename = NULL;
597
ssize_t bytes_read = read(dhpfile,
598
params.data + params.size,
604
/* check bytes_read for failure */
609
dhparamsfilename = NULL;
612
params.size += (unsigned int)bytes_read;
614
if(params.data == NULL){
615
dhparamsfilename = NULL;
617
if(dhparamsfilename == NULL){
620
ret = gnutls_dh_params_import_pkcs3(mc->dh_params, ¶ms,
621
GNUTLS_X509_FMT_PEM);
622
if(ret != GNUTLS_E_SUCCESS){
623
fprintf_plus(stderr, "Failed to parse DH parameters in file"
624
" \"%s\": %s\n", dhparamsfilename,
625
safer_gnutls_strerror(ret));
626
dhparamsfilename = NULL;
630
if(dhparamsfilename == NULL){
631
if(mc->dh_bits == 0){
632
/* Find out the optimal number of DH bits */
633
/* Try to read the private key file */
634
gnutls_datum_t buffer = { .data = NULL, .size = 0 };
636
int secfile = open(seckeyfilename, O_RDONLY);
641
size_t buffer_capacity = 0;
643
buffer_capacity = incbuffer((char **)&buffer.data,
645
(size_t)buffer_capacity);
646
if(buffer_capacity == 0){
647
perror_plus("incbuffer");
652
ssize_t bytes_read = read(secfile,
653
buffer.data + buffer.size,
659
/* check bytes_read for failure */
666
buffer.size += (unsigned int)bytes_read;
670
/* If successful, use buffer to parse private key */
671
gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;
672
if(buffer.data != NULL){
674
gnutls_openpgp_privkey_t privkey = NULL;
675
ret = gnutls_openpgp_privkey_init(&privkey);
676
if(ret != GNUTLS_E_SUCCESS){
677
fprintf_plus(stderr, "Error initializing OpenPGP key"
679
safer_gnutls_strerror(ret));
683
ret = gnutls_openpgp_privkey_import
684
(privkey, &buffer, GNUTLS_OPENPGP_FMT_BASE64, "", 0);
685
if(ret != GNUTLS_E_SUCCESS){
686
fprintf_plus(stderr, "Error importing OpenPGP key : %s",
687
safer_gnutls_strerror(ret));
693
/* Use private key to suggest an appropriate
695
sec_param = gnutls_openpgp_privkey_sec_param(privkey);
696
gnutls_openpgp_privkey_deinit(privkey);
698
fprintf_plus(stderr, "This OpenPGP key implies using"
699
" a GnuTLS security parameter \"%s\".\n",
700
safe_string(gnutls_sec_param_get_name
706
if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){
707
/* Err on the side of caution */
708
sec_param = GNUTLS_SEC_PARAM_ULTRA;
710
fprintf_plus(stderr, "Falling back to security parameter"
712
safe_string(gnutls_sec_param_get_name
717
uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);
721
fprintf_plus(stderr, "A \"%s\" GnuTLS security parameter"
722
" implies %u DH bits; using that.\n",
723
safe_string(gnutls_sec_param_get_name
728
fprintf_plus(stderr, "Failed to get implied number of DH"
729
" bits for security parameter \"%s\"): %s\n",
730
safe_string(gnutls_sec_param_get_name
732
safer_gnutls_strerror(ret));
736
fprintf_plus(stderr, "DH bits explicitly set to %u\n",
739
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
740
if(ret != GNUTLS_E_SUCCESS){
741
fprintf_plus(stderr, "Error in GnuTLS prime generation (%u"
742
" bits): %s\n", mc->dh_bits,
743
safer_gnutls_strerror(ret));
560
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
561
if(ret != GNUTLS_E_SUCCESS){
562
fprintf_plus(stderr, "Error in GnuTLS prime generation: %s\n",
563
safer_gnutls_strerror(ret));
747
567
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
815
638
static void empty_log(__attribute__((unused)) AvahiLogLevel level,
816
639
__attribute__((unused)) const char *txt){}
818
/* Set effective uid to 0, return errno */
819
__attribute__((warn_unused_result))
820
int raise_privileges(void){
821
int old_errno = errno;
823
if(seteuid(0) == -1){
830
/* Set effective and real user ID to 0. Return errno. */
831
__attribute__((warn_unused_result))
832
int raise_privileges_permanently(void){
833
int old_errno = errno;
834
int ret = raise_privileges();
846
/* Set effective user ID to unprivileged saved user ID */
847
__attribute__((warn_unused_result))
848
int lower_privileges(void){
849
int old_errno = errno;
851
if(seteuid(uid) == -1){
858
/* Lower privileges permanently */
859
__attribute__((warn_unused_result))
860
int lower_privileges_permanently(void){
861
int old_errno = errno;
863
if(setuid(uid) == -1){
870
/* Helper function to add_local_route() and delete_local_route() */
871
__attribute__((nonnull, warn_unused_result))
872
static bool add_delete_local_route(const bool add,
874
AvahiIfIndex if_index){
876
char helper[] = "mandos-client-iprouteadddel";
877
char add_arg[] = "add";
878
char delete_arg[] = "delete";
879
char debug_flag[] = "--debug";
880
char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");
881
if(pluginhelperdir == NULL){
883
fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"
884
" variable not set; cannot run helper\n");
889
char interface[IF_NAMESIZE];
890
if(if_indextoname((unsigned int)if_index, interface) == NULL){
891
perror_plus("if_indextoname");
895
int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));
897
perror_plus("open(\"/dev/null\", O_RDONLY)");
903
/* Raise privileges */
904
errno = raise_privileges_permanently();
906
perror_plus("Failed to raise privileges");
907
/* _exit(EX_NOPERM); */
913
perror_plus("setgid");
916
/* Reset supplementary groups */
918
ret = setgroups(0, NULL);
920
perror_plus("setgroups");
924
ret = dup2(devnull, STDIN_FILENO);
926
perror_plus("dup2(devnull, STDIN_FILENO)");
929
ret = close(devnull);
931
perror_plus("close");
934
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
936
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
939
int helperdir_fd = (int)TEMP_FAILURE_RETRY(open(pluginhelperdir,
944
if(helperdir_fd == -1){
946
_exit(EX_UNAVAILABLE);
948
int helper_fd = (int)TEMP_FAILURE_RETRY(openat(helperdir_fd,
951
perror_plus("openat");
953
_exit(EX_UNAVAILABLE);
957
#pragma GCC diagnostic push
958
#pragma GCC diagnostic ignored "-Wcast-qual"
960
if(fexecve(helper_fd, (char *const [])
961
{ helper, add ? add_arg : delete_arg, (char *)address,
962
interface, debug ? debug_flag : NULL, NULL },
965
#pragma GCC diagnostic pop
967
perror_plus("fexecve");
979
pret = waitpid(pid, &status, 0);
980
if(pret == -1 and errno == EINTR and quit_now){
981
int errno_raising = 0;
982
if((errno = raise_privileges()) != 0){
983
errno_raising = errno;
984
perror_plus("Failed to raise privileges in order to"
985
" kill helper program");
987
if(kill(pid, SIGTERM) == -1){
990
if((errno_raising == 0) and (errno = lower_privileges()) != 0){
991
perror_plus("Failed to lower privileges after killing"
996
} while(pret == -1 and errno == EINTR);
998
perror_plus("waitpid");
1001
if(WIFEXITED(status)){
1002
if(WEXITSTATUS(status) != 0){
1003
fprintf_plus(stderr, "Error: iprouteadddel exited"
1004
" with status %d\n", WEXITSTATUS(status));
1009
if(WIFSIGNALED(status)){
1010
fprintf_plus(stderr, "Error: iprouteadddel died by"
1011
" signal %d\n", WTERMSIG(status));
1014
fprintf_plus(stderr, "Error: iprouteadddel crashed\n");
1018
__attribute__((nonnull, warn_unused_result))
1019
static bool add_local_route(const char *address,
1020
AvahiIfIndex if_index){
1022
fprintf_plus(stderr, "Adding route to %s\n", address);
1024
return add_delete_local_route(true, address, if_index);
1027
__attribute__((nonnull, warn_unused_result))
1028
static bool delete_local_route(const char *address,
1029
AvahiIfIndex if_index){
1031
fprintf_plus(stderr, "Removing route to %s\n", address);
1033
return add_delete_local_route(false, address, if_index);
1036
641
/* Called when a Mandos server is found */
1037
642
__attribute__((nonnull, warn_unused_result))
1038
643
static int start_mandos_communication(const char *ip, in_port_t port,
1209
812
goto mandos_end;
1214
ret = connect(tcp_sd, (struct sockaddr *)&to,
1215
sizeof(struct sockaddr_in6));
1217
ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */
1218
sizeof(struct sockaddr_in));
1221
if(((errno == ENETUNREACH) or (errno == EHOSTUNREACH))
1222
and if_index != AVAHI_IF_UNSPEC
1223
and connect_to == NULL
1224
and not route_added and
1225
((af == AF_INET6 and not
1226
IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)
1228
or (af == AF_INET and
1229
/* Not a a IPv4LL address */
1230
(ntohl(((struct sockaddr_in *)&to)->sin_addr.s_addr)
1231
& 0xFFFF0000L) != 0xA9FE0000L))){
1232
/* Work around Avahi bug - Avahi does not announce link-local
1233
addresses if it has a global address, so local hosts with
1234
*only* a link-local address (e.g. Mandos clients) cannot
1235
connect to a Mandos server announced by Avahi on a server
1236
host with a global address. Work around this by retrying
1237
with an explicit route added with the server's address.
1239
Avahi bug reference:
1240
http://lists.freedesktop.org/archives/avahi/2010-February/001833.html
1241
https://bugs.debian.org/587961
1244
fprintf_plus(stderr, "Mandos server unreachable, trying"
1248
route_added = add_local_route(ip, if_index);
1254
if(errno != ECONNREFUSED or debug){
1256
perror_plus("connect");
816
ret = connect(tcp_sd, (struct sockaddr *)&to,
817
sizeof(struct sockaddr_in6));
819
ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */
820
sizeof(struct sockaddr_in));
823
if((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){
825
perror_plus("connect");
1269
836
const char *out = mandos_protocol_version;
1460
/* Set effective uid to 0, return errno */
1461
__attribute__((warn_unused_result))
1462
error_t raise_privileges(void){
1463
error_t old_errno = errno;
1464
error_t ret_errno = 0;
1465
if(seteuid(0) == -1){
1467
perror_plus("seteuid");
1473
/* Set effective and real user ID to 0. Return errno. */
1474
__attribute__((warn_unused_result))
1475
error_t raise_privileges_permanently(void){
1476
error_t old_errno = errno;
1477
error_t ret_errno = raise_privileges();
1482
if(setuid(0) == -1){
1484
perror_plus("seteuid");
1490
/* Set effective user ID to unprivileged saved user ID */
1491
__attribute__((warn_unused_result))
1492
error_t lower_privileges(void){
1493
error_t old_errno = errno;
1494
error_t ret_errno = 0;
1495
if(seteuid(uid) == -1){
1497
perror_plus("seteuid");
1503
/* Lower privileges permanently */
1504
__attribute__((warn_unused_result))
1505
error_t lower_privileges_permanently(void){
1506
error_t old_errno = errno;
1507
error_t ret_errno = 0;
1508
if(setuid(uid) == -1){
1510
perror_plus("setuid");
1893
1516
__attribute__((nonnull))
1894
1517
void run_network_hooks(const char *mode, const char *interface,
1895
1518
const float delay){
1896
struct dirent **direntries = NULL;
1897
if(hookdir_fd == -1){
1898
hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH
1900
if(hookdir_fd == -1){
1901
if(errno == ENOENT){
1903
fprintf_plus(stderr, "Network hook directory \"%s\" not"
1904
" found\n", hookdir);
1907
perror_plus("open");
1912
int numhooks = scandirat(hookdir_fd, ".", &direntries,
1913
runnable_hook, alphasort);
1519
struct dirent **direntries;
1520
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1914
1522
if(numhooks == -1){
1915
perror_plus("scandir");
1918
struct dirent *direntry;
1920
int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));
1922
perror_plus("open(\"/dev/null\", O_RDONLY)");
1925
for(int i = 0; i < numhooks; i++){
1926
direntry = direntries[i];
1928
fprintf_plus(stderr, "Running network hook \"%s\"\n",
1523
if(errno == ENOENT){
1525
fprintf_plus(stderr, "Network hook directory \"%s\" not"
1526
" found\n", hookdir);
1529
perror_plus("scandir");
1931
pid_t hook_pid = fork();
1934
/* Raise privileges */
1935
errno = raise_privileges_permanently();
1937
perror_plus("Failed to raise privileges");
1944
perror_plus("setgid");
1947
/* Reset supplementary groups */
1949
ret = setgroups(0, NULL);
1951
perror_plus("setgroups");
1954
ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);
1956
perror_plus("setenv");
1959
ret = setenv("DEVICE", interface, 1);
1961
perror_plus("setenv");
1964
ret = setenv("VERBOSITY", debug ? "1" : "0", 1);
1966
perror_plus("setenv");
1969
ret = setenv("MODE", mode, 1);
1971
perror_plus("setenv");
1975
ret = asprintf(&delaystring, "%f", (double)delay);
1532
struct dirent *direntry;
1534
int devnull = open("/dev/null", O_RDONLY);
1535
for(int i = 0; i < numhooks; i++){
1536
direntry = direntries[i];
1537
char *fullname = NULL;
1538
ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);
1977
1540
perror_plus("asprintf");
1980
ret = setenv("DELAY", delaystring, 1);
1544
fprintf_plus(stderr, "Running network hook \"%s\"\n",
1547
pid_t hook_pid = fork();
1550
/* Raise privileges */
1551
if(raise_privileges_permanently() != 0){
1552
perror_plus("Failed to raise privileges");
1559
perror_plus("setgid");
1562
/* Reset supplementary groups */
1564
ret = setgroups(0, NULL);
1566
perror_plus("setgroups");
1569
ret = dup2(devnull, STDIN_FILENO);
1571
perror_plus("dup2(devnull, STDIN_FILENO)");
1574
ret = close(devnull);
1576
perror_plus("close");
1579
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
1581
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
1584
ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);
1586
perror_plus("setenv");
1589
ret = setenv("DEVICE", interface, 1);
1591
perror_plus("setenv");
1594
ret = setenv("VERBOSITY", debug ? "1" : "0", 1);
1596
perror_plus("setenv");
1599
ret = setenv("MODE", mode, 1);
1601
perror_plus("setenv");
1605
ret = asprintf(&delaystring, "%f", (double)delay);
1607
perror_plus("asprintf");
1610
ret = setenv("DELAY", delaystring, 1);
1613
perror_plus("setenv");
1982
1616
free(delaystring);
1983
perror_plus("setenv");
1987
if(connect_to != NULL){
1988
ret = setenv("CONNECT", connect_to, 1);
1990
perror_plus("setenv");
1994
int hook_fd = (int)TEMP_FAILURE_RETRY(openat(hookdir_fd,
1998
perror_plus("openat");
1999
_exit(EXIT_FAILURE);
2001
if(close(hookdir_fd) == -1){
2002
perror_plus("close");
2003
_exit(EXIT_FAILURE);
2005
ret = dup2(devnull, STDIN_FILENO);
2007
perror_plus("dup2(devnull, STDIN_FILENO)");
2010
ret = close(devnull);
2012
perror_plus("close");
2015
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
2017
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
2020
if(fexecve(hook_fd, (char *const []){ direntry->d_name, NULL },
2022
perror_plus("fexecve");
2023
_exit(EXIT_FAILURE);
2027
perror_plus("fork");
2032
if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){
2033
perror_plus("waitpid");
2037
if(WIFEXITED(status)){
2038
if(WEXITSTATUS(status) != 0){
2039
fprintf_plus(stderr, "Warning: network hook \"%s\" exited"
2040
" with status %d\n", direntry->d_name,
2041
WEXITSTATUS(status));
2045
} else if(WIFSIGNALED(status)){
2046
fprintf_plus(stderr, "Warning: network hook \"%s\" died by"
2047
" signal %d\n", direntry->d_name,
1617
if(connect_to != NULL){
1618
ret = setenv("CONNECT", connect_to, 1);
1620
perror_plus("setenv");
1624
if(execl(fullname, direntry->d_name, mode, NULL) == -1){
1625
perror_plus("execl");
1626
_exit(EXIT_FAILURE);
2052
fprintf_plus(stderr, "Warning: network hook \"%s\""
2053
" crashed\n", direntry->d_name);
2059
fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",
2065
if(close(hookdir_fd) == -1){
2066
perror_plus("close");
1630
if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){
1631
perror_plus("waitpid");
1635
if(WIFEXITED(status)){
1636
if(WEXITSTATUS(status) != 0){
1637
fprintf_plus(stderr, "Warning: network hook \"%s\" exited"
1638
" with status %d\n", direntry->d_name,
1639
WEXITSTATUS(status));
1643
} else if(WIFSIGNALED(status)){
1644
fprintf_plus(stderr, "Warning: network hook \"%s\" died by"
1645
" signal %d\n", direntry->d_name,
1650
fprintf_plus(stderr, "Warning: network hook \"%s\""
1651
" crashed\n", direntry->d_name);
1658
fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",
2073
1666
__attribute__((nonnull, warn_unused_result))
2074
int bring_up_interface(const char *const interface,
2076
int old_errno = errno;
1667
error_t bring_up_interface(const char *const interface,
1669
error_t old_errno = errno;
2078
1671
struct ifreq network;
2079
1672
unsigned int if_index = if_nametoindex(interface);
3030
2573
free(interfaces_to_take_down);
3031
2574
free(interfaces_hooks);
3033
void clean_dir_at(int base, const char * const dirname,
3035
struct dirent **direntries = NULL;
3037
int dir_fd = (int)TEMP_FAILURE_RETRY(openat(base, dirname,
3043
perror_plus("open");
3045
int numentries = scandirat(dir_fd, ".", &direntries,
3046
notdotentries, alphasort);
3047
if(numentries >= 0){
3048
for(int i = 0; i < numentries; i++){
3050
fprintf_plus(stderr, "Unlinking \"%s/%s\"\n",
3051
dirname, direntries[i]->d_name);
3053
dret = unlinkat(dir_fd, direntries[i]->d_name, 0);
3055
if(errno == EISDIR){
3056
dret = unlinkat(dir_fd, direntries[i]->d_name,
3059
if((dret == -1) and (errno == ENOTEMPTY)
3060
and (strcmp(direntries[i]->d_name, "private-keys-v1.d")
3061
== 0) and (level == 0)){
3062
/* Recurse only in this special case */
3063
clean_dir_at(dir_fd, direntries[i]->d_name, level+1);
3067
fprintf_plus(stderr, "unlink(\"%s/%s\"): %s\n", dirname,
3068
direntries[i]->d_name, strerror(errno));
3071
free(direntries[i]);
3074
/* need to clean even if 0 because man page doesn't specify */
3076
if(numentries == -1){
3077
perror_plus("scandirat");
3079
dret = unlinkat(base, dirname, AT_REMOVEDIR);
3080
if(dret == -1 and errno != ENOENT){
3081
perror_plus("rmdir");
3084
perror_plus("scandirat");
3089
2576
/* Removes the GPGME temp directory and all files inside */
3090
2577
if(tempdir != NULL){
3091
clean_dir_at(-1, tempdir, 0);
2578
struct dirent **direntries = NULL;
2579
struct dirent *direntry = NULL;
2580
int numentries = scandir(tempdir, &direntries, notdotentries,
2583
for(int i = 0; i < numentries; i++){
2584
direntry = direntries[i];
2585
char *fullname = NULL;
2586
ret = asprintf(&fullname, "%s/%s", tempdir,
2589
perror_plus("asprintf");
2592
ret = remove(fullname);
2594
fprintf_plus(stderr, "remove(\"%s\"): %s\n", fullname,
2601
/* need to clean even if 0 because man page doesn't specify */
2603
if(numentries == -1){
2604
perror_plus("scandir");
2606
ret = rmdir(tempdir);
2607
if(ret == -1 and errno != ENOENT){
2608
perror_plus("rmdir");