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- Committer: Teddy Hogeborn
- Date: 2014-06-07 21:59:20 UTC
- Revision ID: teddy@recompile.se-20140607215920-r4qkj7ktnjyqmrn5
Make mandos-client use fexecve().
* plugins.d/mandos-client.d (run_network_hooks): Use fexecve().
* plugins.d/mandos-client.d (run_network_hooks): Use fexecve().
- files removed:
- plugin-helpers
- files modified:
- DBUS-API
added
removed
plugins.d/mandos-client.c
9
9
* "browse_callback", and parts of "main".
10
10
*
11
11
* Everything else is
12
* Copyright © 2008-2015 Teddy Hogeborn
13
* Copyright © 2008-2015 Björn Påhlsson
12
* Copyright © 2008-2014 Teddy Hogeborn
13
* Copyright © 2008-2014 Björn Påhlsson
14
14
*
15
15
* This program is free software: you can redistribute it and/or
16
16
* modify it under the terms of the GNU General Public License as
40
40
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
41
41
42
42
#include <stdio.h> /* fprintf(), stderr, fwrite(),
43
stdout, ferror() */
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(), strcpy() */
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(),
59
59
getnameinfo() */
60
#include <fcntl.h> /* open(), unlinkat() */
60
#include <fcntl.h> /* open() */
61
61
#include <dirent.h> /* opendir(), struct dirent, readdir()
62
62
*/
63
63
#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,
73
73
*/
74
74
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
75
75
getuid(), getgid(), seteuid(),
76
setgid(), pause(), _exit(),
77
unlinkat() */
76
setgid(), pause(), _exit() */
78
77
#include <arpa/inet.h> /* inet_pton(), htons() */
79
78
#include <iso646.h> /* not, or, and */
80
79
#include <argp.h> /* struct argp_option, error_t, struct
234
233
.af = af };
235
234
if(new_server->ip == NULL){
236
235
perror_plus("strdup");
237
free(new_server);
238
236
return false;
239
237
}
240
238
ret = clock_gettime(CLOCK_MONOTONIC, &(new_server->last_seen));
241
239
if(ret == -1){
242
240
perror_plus("clock_gettime");
243
#ifdef __GNUC__
244
#pragma GCC diagnostic push
245
#pragma GCC diagnostic ignored "-Wcast-qual"
246
#endif
247
free((char *)(new_server->ip));
248
#ifdef __GNUC__
249
#pragma GCC diagnostic pop
250
#endif
251
free(new_server);
252
241
return false;
253
242
}
254
243
/* Special case of first server */
305
294
return false;
306
295
}
307
296
308
ret = close(fd);
297
ret = (int)TEMP_FAILURE_RETRY(close(fd));
309
298
if(ret == -1){
310
299
perror_plus("close");
311
300
}
493
482
return plaintext_length;
494
483
}
495
484
496
__attribute__((warn_unused_result, const))
497
static const char *safe_string(const char *str){
498
if(str == NULL)
499
return "(unknown)";
500
return str;
501
}
502
503
485
__attribute__((warn_unused_result))
504
486
static const char *safer_gnutls_strerror(int value){
505
487
const char *ret = gnutls_strerror(value);
506
return safe_string(ret);
488
if(ret == NULL)
489
ret = "(unknown)";
490
return ret;
507
491
}
508
492
509
493
/* GnuTLS log function callback */
516
500
__attribute__((nonnull, warn_unused_result))
517
501
static int init_gnutls_global(const char *pubkeyfilename,
518
502
const char *seckeyfilename,
519
const char *dhparamsfilename,
520
503
mandos_context *mc){
521
504
int ret;
522
unsigned int uret;
523
505
524
506
if(debug){
525
507
fprintf_plus(stderr, "Initializing GnuTLS\n");
576
558
safer_gnutls_strerror(ret));
577
559
goto globalfail;
578
560
}
579
/* If a Diffie-Hellman parameters file was given, try to use it */
580
if(dhparamsfilename != NULL){
581
gnutls_datum_t params = { .data = NULL, .size = 0 };
582
do {
583
int dhpfile = open(dhparamsfilename, O_RDONLY);
584
if(dhpfile == -1){
585
perror_plus("open");
586
dhparamsfilename = NULL;
587
break;
588
}
589
size_t params_capacity = 0;
590
while(true){
591
params_capacity = incbuffer((char **)¶ms.data,
592
(size_t)params.size,
593
(size_t)params_capacity);
594
if(params_capacity == 0){
595
perror_plus("incbuffer");
596
free(params.data);
597
params.data = NULL;
598
dhparamsfilename = NULL;
599
break;
600
}
601
ssize_t bytes_read = read(dhpfile,
602
params.data + params.size,
603
BUFFER_SIZE);
604
/* EOF */
605
if(bytes_read == 0){
606
break;
607
}
608
/* check bytes_read for failure */
609
if(bytes_read < 0){
610
perror_plus("read");
611
free(params.data);
612
params.data = NULL;
613
dhparamsfilename = NULL;
614
break;
615
}
616
params.size += (unsigned int)bytes_read;
617
}
618
if(params.data == NULL){
619
dhparamsfilename = NULL;
620
}
621
if(dhparamsfilename == NULL){
622
break;
623
}
624
ret = gnutls_dh_params_import_pkcs3(mc->dh_params, ¶ms,
625
GNUTLS_X509_FMT_PEM);
626
if(ret != GNUTLS_E_SUCCESS){
627
fprintf_plus(stderr, "Failed to parse DH parameters in file"
628
" \"%s\": %s\n", dhparamsfilename,
629
safer_gnutls_strerror(ret));
630
dhparamsfilename = NULL;
631
}
632
} while(false);
633
}
634
if(dhparamsfilename == NULL){
635
if(mc->dh_bits == 0){
636
/* Find out the optimal number of DH bits */
637
/* Try to read the private key file */
638
gnutls_datum_t buffer = { .data = NULL, .size = 0 };
639
do {
640
int secfile = open(seckeyfilename, O_RDONLY);
641
if(secfile == -1){
642
perror_plus("open");
643
break;
644
}
645
size_t buffer_capacity = 0;
646
while(true){
647
buffer_capacity = incbuffer((char **)&buffer.data,
648
(size_t)buffer.size,
649
(size_t)buffer_capacity);
650
if(buffer_capacity == 0){
651
perror_plus("incbuffer");
652
free(buffer.data);
653
buffer.data = NULL;
654
break;
655
}
656
ssize_t bytes_read = read(secfile,
657
buffer.data + buffer.size,
658
BUFFER_SIZE);
659
/* EOF */
660
if(bytes_read == 0){
661
break;
662
}
663
/* check bytes_read for failure */
664
if(bytes_read < 0){
665
perror_plus("read");
666
free(buffer.data);
667
buffer.data = NULL;
668
break;
669
}
670
buffer.size += (unsigned int)bytes_read;
671
}
672
close(secfile);
673
} while(false);
674
/* If successful, use buffer to parse private key */
675
gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;
676
if(buffer.data != NULL){
677
{
678
gnutls_openpgp_privkey_t privkey = NULL;
679
ret = gnutls_openpgp_privkey_init(&privkey);
680
if(ret != GNUTLS_E_SUCCESS){
681
fprintf_plus(stderr, "Error initializing OpenPGP key"
682
" structure: %s",
683
safer_gnutls_strerror(ret));
684
free(buffer.data);
685
buffer.data = NULL;
686
} else {
687
ret = gnutls_openpgp_privkey_import
688
(privkey, &buffer, GNUTLS_OPENPGP_FMT_BASE64, "", 0);
689
if(ret != GNUTLS_E_SUCCESS){
690
fprintf_plus(stderr, "Error importing OpenPGP key : %s",
691
safer_gnutls_strerror(ret));
692
privkey = NULL;
693
}
694
free(buffer.data);
695
buffer.data = NULL;
696
if(privkey != NULL){
697
/* Use private key to suggest an appropriate
698
sec_param */
699
sec_param = gnutls_openpgp_privkey_sec_param(privkey);
700
gnutls_openpgp_privkey_deinit(privkey);
701
if(debug){
702
fprintf_plus(stderr, "This OpenPGP key implies using"
703
" a GnuTLS security parameter \"%s\".\n",
704
safe_string(gnutls_sec_param_get_name
705
(sec_param)));
706
}
707
}
708
}
709
}
710
if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){
711
/* Err on the side of caution */
712
sec_param = GNUTLS_SEC_PARAM_ULTRA;
713
if(debug){
714
fprintf_plus(stderr, "Falling back to security parameter"
715
" \"%s\"\n",
716
safe_string(gnutls_sec_param_get_name
717
(sec_param)));
718
}
719
}
720
}
721
uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);
722
if(uret != 0){
723
mc->dh_bits = uret;
724
if(debug){
725
fprintf_plus(stderr, "A \"%s\" GnuTLS security parameter"
726
" implies %u DH bits; using that.\n",
727
safe_string(gnutls_sec_param_get_name
728
(sec_param)),
729
mc->dh_bits);
730
}
731
} else {
732
fprintf_plus(stderr, "Failed to get implied number of DH"
733
" bits for security parameter \"%s\"): %s\n",
734
safe_string(gnutls_sec_param_get_name
735
(sec_param)),
736
safer_gnutls_strerror(ret));
737
goto globalfail;
738
}
739
} else if(debug){
740
fprintf_plus(stderr, "DH bits explicitly set to %u\n",
741
mc->dh_bits);
742
}
743
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
744
if(ret != GNUTLS_E_SUCCESS){
745
fprintf_plus(stderr, "Error in GnuTLS prime generation (%u"
746
" bits): %s\n", mc->dh_bits,
747
safer_gnutls_strerror(ret));
748
goto globalfail;
749
}
750
}
561
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
562
if(ret != GNUTLS_E_SUCCESS){
563
fprintf_plus(stderr, "Error in GnuTLS prime generation: %s\n",
564
safer_gnutls_strerror(ret));
565
goto globalfail;
566
}
567
751
568
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
752
569
753
570
return 0;
813
630
/* ignore client certificate if any. */
814
631
gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);
815
632
633
gnutls_dh_set_prime_bits(*session, mc->dh_bits);
634
816
635
return 0;
817
636
}
818
637
820
639
static void empty_log(__attribute__((unused)) AvahiLogLevel level,
821
640
__attribute__((unused)) const char *txt){}
822
641
823
/* Set effective uid to 0, return errno */
824
__attribute__((warn_unused_result))
825
error_t raise_privileges(void){
826
error_t old_errno = errno;
827
error_t ret_errno = 0;
828
if(seteuid(0) == -1){
829
ret_errno = errno;
830
}
831
errno = old_errno;
832
return ret_errno;
833
}
834
835
/* Set effective and real user ID to 0. Return errno. */
836
__attribute__((warn_unused_result))
837
error_t raise_privileges_permanently(void){
838
error_t old_errno = errno;
839
error_t ret_errno = raise_privileges();
840
if(ret_errno != 0){
841
errno = old_errno;
842
return ret_errno;
843
}
844
if(setuid(0) == -1){
845
ret_errno = errno;
846
}
847
errno = old_errno;
848
return ret_errno;
849
}
850
851
/* Set effective user ID to unprivileged saved user ID */
852
__attribute__((warn_unused_result))
853
error_t lower_privileges(void){
854
error_t old_errno = errno;
855
error_t ret_errno = 0;
856
if(seteuid(uid) == -1){
857
ret_errno = errno;
858
}
859
errno = old_errno;
860
return ret_errno;
861
}
862
863
/* Lower privileges permanently */
864
__attribute__((warn_unused_result))
865
error_t lower_privileges_permanently(void){
866
error_t old_errno = errno;
867
error_t ret_errno = 0;
868
if(setuid(uid) == -1){
869
ret_errno = errno;
870
}
871
errno = old_errno;
872
return ret_errno;
873
}
874
875
/* Helper function to add_local_route() and delete_local_route() */
876
__attribute__((nonnull, warn_unused_result))
877
static bool add_delete_local_route(const bool add,
878
const char *address,
879
AvahiIfIndex if_index){
880
int ret;
881
char helper[] = "mandos-client-iprouteadddel";
882
char add_arg[] = "add";
883
char delete_arg[] = "delete";
884
char debug_flag[] = "--debug";
885
char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");
886
if(pluginhelperdir == NULL){
887
if(debug){
888
fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"
889
" variable not set; cannot run helper\n");
890
}
891
return false;
892
}
893
894
char interface[IF_NAMESIZE];
895
if(if_indextoname((unsigned int)if_index, interface) == NULL){
896
perror_plus("if_indextoname");
897
return false;
898
}
899
900
int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));
901
if(devnull == -1){
902
perror_plus("open(\"/dev/null\", O_RDONLY)");
903
return false;
904
}
905
pid_t pid = fork();
906
if(pid == 0){
907
/* Child */
908
/* Raise privileges */
909
errno = raise_privileges_permanently();
910
if(errno != 0){
911
perror_plus("Failed to raise privileges");
912
/* _exit(EX_NOPERM); */
913
} else {
914
/* Set group */
915
errno = 0;
916
ret = setgid(0);
917
if(ret == -1){
918
perror_plus("setgid");
919
_exit(EX_NOPERM);
920
}
921
/* Reset supplementary groups */
922
errno = 0;
923
ret = setgroups(0, NULL);
924
if(ret == -1){
925
perror_plus("setgroups");
926
_exit(EX_NOPERM);
927
}
928
}
929
ret = dup2(devnull, STDIN_FILENO);
930
if(ret == -1){
931
perror_plus("dup2(devnull, STDIN_FILENO)");
932
_exit(EX_OSERR);
933
}
934
ret = close(devnull);
935
if(ret == -1){
936
perror_plus("close");
937
_exit(EX_OSERR);
938
}
939
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
940
if(ret == -1){
941
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
942
_exit(EX_OSERR);
943
}
944
int helperdir_fd = (int)TEMP_FAILURE_RETRY(open(pluginhelperdir,
945
O_RDONLY
946
| O_DIRECTORY
947
| O_PATH
948
| O_CLOEXEC));
949
if(helperdir_fd == -1){
950
perror_plus("open");
951
_exit(EX_UNAVAILABLE);
952
}
953
int helper_fd = (int)TEMP_FAILURE_RETRY(openat(helperdir_fd,
954
helper, O_RDONLY));
955
if(helper_fd == -1){
956
perror_plus("openat");
957
close(helperdir_fd);
958
_exit(EX_UNAVAILABLE);
959
}
960
close(helperdir_fd);
961
#ifdef __GNUC__
962
#pragma GCC diagnostic push
963
#pragma GCC diagnostic ignored "-Wcast-qual"
964
#endif
965
if(fexecve(helper_fd, (char *const [])
966
{ helper, add ? add_arg : delete_arg, (char *)address,
967
interface, debug ? debug_flag : NULL, NULL },
968
environ) == -1){
969
#ifdef __GNUC__
970
#pragma GCC diagnostic pop
971
#endif
972
perror_plus("fexecve");
973
_exit(EXIT_FAILURE);
974
}
975
}
976
if(pid == -1){
977
perror_plus("fork");
978
return false;
979
}
980
int status;
981
pid_t pret = -1;
982
errno = 0;
983
do {
984
pret = waitpid(pid, &status, 0);
985
if(pret == -1 and errno == EINTR and quit_now){
986
int errno_raising = 0;
987
if((errno = raise_privileges()) != 0){
988
errno_raising = errno;
989
perror_plus("Failed to raise privileges in order to"
990
" kill helper program");
991
}
992
if(kill(pid, SIGTERM) == -1){
993
perror_plus("kill");
994
}
995
if((errno_raising == 0) and (errno = lower_privileges()) != 0){
996
perror_plus("Failed to lower privileges after killing"
997
" helper program");
998
}
999
return false;
1000
}
1001
} while(pret == -1 and errno == EINTR);
1002
if(pret == -1){
1003
perror_plus("waitpid");
1004
return false;
1005
}
1006
if(WIFEXITED(status)){
1007
if(WEXITSTATUS(status) != 0){
1008
fprintf_plus(stderr, "Error: iprouteadddel exited"
1009
" with status %d\n", WEXITSTATUS(status));
1010
return false;
1011
}
1012
return true;
1013
}
1014
if(WIFSIGNALED(status)){
1015
fprintf_plus(stderr, "Error: iprouteadddel died by"
1016
" signal %d\n", WTERMSIG(status));
1017
return false;
1018
}
1019
fprintf_plus(stderr, "Error: iprouteadddel crashed\n");
1020
return false;
1021
}
1022
1023
__attribute__((nonnull, warn_unused_result))
1024
static bool add_local_route(const char *address,
1025
AvahiIfIndex if_index){
1026
if(debug){
1027
fprintf_plus(stderr, "Adding route to %s\n", address);
1028
}
1029
return add_delete_local_route(true, address, if_index);
1030
}
1031
1032
__attribute__((nonnull, warn_unused_result))
1033
static bool delete_local_route(const char *address,
1034
AvahiIfIndex if_index){
1035
if(debug){
1036
fprintf_plus(stderr, "Removing route to %s\n", address);
1037
}
1038
return add_delete_local_route(false, address, if_index);
1039
}
1040
1041
642
/* Called when a Mandos server is found */
1042
643
__attribute__((nonnull, warn_unused_result))
1043
644
static int start_mandos_communication(const char *ip, in_port_t port,
1054
655
int retval = -1;
1055
656
gnutls_session_t session;
1056
657
int pf; /* Protocol family */
1057
bool route_added = false;
1058
658
1059
659
errno = 0;
1060
660
1118
718
PRIuMAX "\n", ip, (uintmax_t)port);
1119
719
}
1120
720
1121
tcp_sd = socket(pf, SOCK_STREAM | SOCK_CLOEXEC, 0);
721
tcp_sd = socket(pf, SOCK_STREAM, 0);
1122
722
if(tcp_sd < 0){
1123
723
int e = errno;
1124
724
perror_plus("socket");
1131
731
goto mandos_end;
1132
732
}
1133
733
734
memset(&to, 0, sizeof(to));
1134
735
if(af == AF_INET6){
1135
struct sockaddr_in6 *to6 = (struct sockaddr_in6 *)&to;
1136
*to6 = (struct sockaddr_in6){ .sin6_family = (sa_family_t)af };
1137
ret = inet_pton(af, ip, &to6->sin6_addr);
736
((struct sockaddr_in6 *)&to)->sin6_family = (sa_family_t)af;
737
ret = inet_pton(af, ip, &((struct sockaddr_in6 *)&to)->sin6_addr);
1138
738
} else { /* IPv4 */
1139
struct sockaddr_in *to4 = (struct sockaddr_in *)&to;
1140
*to4 = (struct sockaddr_in){ .sin_family = (sa_family_t)af };
1141
ret = inet_pton(af, ip, &to4->sin_addr);
739
((struct sockaddr_in *)&to)->sin_family = (sa_family_t)af;
740
ret = inet_pton(af, ip, &((struct sockaddr_in *)&to)->sin_addr);
1142
741
}
1143
742
if(ret < 0 ){
1144
743
int e = errno;
1214
813
goto mandos_end;
1215
814
}
1216
815
1217
while(true){
1218
if(af == AF_INET6){
1219
ret = connect(tcp_sd, (struct sockaddr *)&to,
1220
sizeof(struct sockaddr_in6));
1221
} else {
1222
ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */
1223
sizeof(struct sockaddr_in));
1224
}
1225
if(ret < 0){
1226
if(errno == ENETUNREACH
1227
and if_index != AVAHI_IF_UNSPEC
1228
and connect_to == NULL
1229
and not route_added and
1230
((af == AF_INET6 and not
1231
IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)
1232
&to)->sin6_addr)))
1233
or (af == AF_INET and
1234
/* Not a a IPv4LL address */
1235
(ntohl(((struct sockaddr_in *)&to)->sin_addr.s_addr)
1236
& 0xFFFF0000L) != 0xA9FE0000L))){
1237
/* Work around Avahi bug - Avahi does not announce link-local
1238
addresses if it has a global address, so local hosts with
1239
*only* a link-local address (e.g. Mandos clients) cannot
1240
connect to a Mandos server announced by Avahi on a server
1241
host with a global address. Work around this by retrying
1242
with an explicit route added with the server's address.
1243
1244
Avahi bug reference:
1245
http://lists.freedesktop.org/archives/avahi/2010-February/001833.html
1246
https://bugs.debian.org/587961
1247
*/
1248
if(debug){
1249
fprintf_plus(stderr, "Mandos server unreachable, trying"
1250
" direct route\n");
1251
}
1252
int e = errno;
1253
route_added = add_local_route(ip, if_index);
1254
if(route_added){
1255
continue;
1256
}
1257
errno = e;
1258
}
1259
if(errno != ECONNREFUSED or debug){
1260
int e = errno;
1261
perror_plus("connect");
1262
errno = e;
1263
}
1264
goto mandos_end;
1265
}
1266
1267
if(quit_now){
1268
errno = EINTR;
1269
goto mandos_end;
1270
}
1271
break;
816
if(af == AF_INET6){
817
ret = connect(tcp_sd, (struct sockaddr *)&to,
818
sizeof(struct sockaddr_in6));
819
} else {
820
ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */
821
sizeof(struct sockaddr_in));
822
}
823
if(ret < 0){
824
if((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){
825
int e = errno;
826
perror_plus("connect");
827
errno = e;
828
}
829
goto mandos_end;
830
}
831
832
if(quit_now){
833
errno = EINTR;
834
goto mandos_end;
1272
835
}
1273
836
1274
837
const char *out = mandos_protocol_version;
1457
1020
1458
1021
mandos_end:
1459
1022
{
1460
if(route_added){
1461
if(not delete_local_route(ip, if_index)){
1462
fprintf_plus(stderr, "Failed to delete local route to %s on"
1463
" interface %d", ip, if_index);
1464
}
1465
}
1466
1023
int e = errno;
1467
1024
free(decrypted_buffer);
1468
1025
free(buffer);
1469
1026
if(tcp_sd >= 0){
1470
ret = close(tcp_sd);
1027
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
1471
1028
}
1472
1029
if(ret == -1){
1473
1030
if(e == 0){
1508
1065
timed out */
1509
1066
1510
1067
if(quit_now){
1511
avahi_s_service_resolver_free(r);
1512
1068
return;
1513
1069
}
1514
1070
1790
1346
return 0;
1791
1347
}
1792
1348
1793
ret = fstatat(hookdir_fd, direntry->d_name, &st, 0);
1349
char *fullname = NULL;
1350
ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);
1351
if(ret < 0){
1352
perror_plus("asprintf");
1353
return 0;
1354
}
1355
1356
ret = stat(fullname, &st);
1794
1357
if(ret == -1){
1795
1358
if(debug){
1796
1359
perror_plus("Could not stat hook");
1797
1360
}
1798
1361
return 0;
1799
1362
}
1363
free(fullname);
1800
1364
if(not (S_ISREG(st.st_mode))){
1801
1365
/* Not a regular file */
1802
1366
if(debug){
1894
1458
}
1895
1459
}
1896
1460
1461
/* Set effective uid to 0, return errno */
1462
__attribute__((warn_unused_result))
1463
error_t raise_privileges(void){
1464
error_t old_errno = errno;
1465
error_t ret_errno = 0;
1466
if(seteuid(0) == -1){
1467
ret_errno = errno;
1468
perror_plus("seteuid");
1469
}
1470
errno = old_errno;
1471
return ret_errno;
1472
}
1473
1474
/* Set effective and real user ID to 0. Return errno. */
1475
__attribute__((warn_unused_result))
1476
error_t raise_privileges_permanently(void){
1477
error_t old_errno = errno;
1478
error_t ret_errno = raise_privileges();
1479
if(ret_errno != 0){
1480
errno = old_errno;
1481
return ret_errno;
1482
}
1483
if(setuid(0) == -1){
1484
ret_errno = errno;
1485
perror_plus("seteuid");
1486
}
1487
errno = old_errno;
1488
return ret_errno;
1489
}
1490
1491
/* Set effective user ID to unprivileged saved user ID */
1492
__attribute__((warn_unused_result))
1493
error_t lower_privileges(void){
1494
error_t old_errno = errno;
1495
error_t ret_errno = 0;
1496
if(seteuid(uid) == -1){
1497
ret_errno = errno;
1498
perror_plus("seteuid");
1499
}
1500
errno = old_errno;
1501
return ret_errno;
1502
}
1503
1504
/* Lower privileges permanently */
1505
__attribute__((warn_unused_result))
1506
error_t lower_privileges_permanently(void){
1507
error_t old_errno = errno;
1508
error_t ret_errno = 0;
1509
if(setuid(uid) == -1){
1510
ret_errno = errno;
1511
perror_plus("setuid");
1512
}
1513
errno = old_errno;
1514
return ret_errno;
1515
}
1516
1517
#ifndef O_CLOEXEC
1518
/*
1519
* Based on the example in the GNU LibC manual chapter 13.13 "File
1520
* Descriptor Flags".
1521
| [[info:libc:Descriptor%20Flags][File Descriptor Flags]] |
1522
*/
1523
__attribute__((warn_unused_result))
1524
static int set_cloexec_flag(int fd){
1525
int ret = (int)TEMP_FAILURE_RETRY(fcntl(fd, F_GETFD, 0));
1526
/* If reading the flags failed, return error indication now. */
1527
if(ret < 0){
1528
return ret;
1529
}
1530
/* Store modified flag word in the descriptor. */
1531
return (int)TEMP_FAILURE_RETRY(fcntl(fd, F_SETFD,
1532
ret | FD_CLOEXEC));
1533
}
1534
#endif /* not O_CLOEXEC */
1535
1897
1536
__attribute__((nonnull))
1898
1537
void run_network_hooks(const char *mode, const char *interface,
1899
1538
const float delay){
1900
struct dirent **direntries = NULL;
1539
struct dirent **direntries;
1901
1540
if(hookdir_fd == -1){
1902
hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH
1903
| O_CLOEXEC);
1541
hookdir_fd = open(hookdir, O_RDONLY |
1542
#ifdef O_CLOEXEC
1543
O_CLOEXEC
1544
#else /* not O_CLOEXEC */
1545
0
1546
#endif /* not O_CLOEXEC */
1547
);
1904
1548
if(hookdir_fd == -1){
1905
1549
if(errno == ENOENT){
1906
1550
if(debug){
1912
1556
}
1913
1557
return;
1914
1558
}
1559
#ifndef O_CLOEXEC
1560
if(set_cloexec_flag(hookdir_fd) < 0){
1561
perror_plus("set_cloexec_flag");
1562
if((int)TEMP_FAILURE_RETRY(close(hookdir_fd)) == -1){
1563
perror_plus("close");
1564
} else {
1565
hookdir_fd = -1;
1566
}
1567
return;
1568
}
1569
#endif /* not O_CLOEXEC */
1915
1570
}
1916
1571
#ifdef __GLIBC__
1917
1572
#if __GLIBC_PREREQ(2, 15)
1931
1586
}
1932
1587
struct dirent *direntry;
1933
1588
int ret;
1934
int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));
1935
if(devnull == -1){
1936
perror_plus("open(\"/dev/null\", O_RDONLY)");
1937
return;
1938
}
1589
int devnull = open("/dev/null", O_RDONLY);
1939
1590
for(int i = 0; i < numhooks; i++){
1940
1591
direntry = direntries[i];
1941
1592
if(debug){
1946
1597
if(hook_pid == 0){
1947
1598
/* Child */
1948
1599
/* Raise privileges */
1949
errno = raise_privileges_permanently();
1950
if(errno != 0){
1600
if(raise_privileges_permanently() != 0){
1951
1601
perror_plus("Failed to raise privileges");
1952
1602
_exit(EX_NOPERM);
1953
1603
}
1965
1615
perror_plus("setgroups");
1966
1616
_exit(EX_NOPERM);
1967
1617
}
1618
ret = dup2(devnull, STDIN_FILENO);
1619
if(ret == -1){
1620
perror_plus("dup2(devnull, STDIN_FILENO)");
1621
_exit(EX_OSERR);
1622
}
1623
ret = close(devnull);
1624
if(ret == -1){
1625
perror_plus("close");
1626
_exit(EX_OSERR);
1627
}
1628
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
1629
if(ret == -1){
1630
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
1631
_exit(EX_OSERR);
1632
}
1968
1633
ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);
1969
1634
if(ret == -1){
1970
1635
perror_plus("setenv");
2005
1670
_exit(EX_OSERR);
2006
1671
}
2007
1672
}
2008
int hook_fd = (int)TEMP_FAILURE_RETRY(openat(hookdir_fd,
2009
direntry->d_name,
2010
O_RDONLY));
2011
if(hook_fd == -1){
2012
perror_plus("openat");
2013
_exit(EXIT_FAILURE);
2014
}
2015
if(close(hookdir_fd) == -1){
2016
perror_plus("close");
2017
_exit(EXIT_FAILURE);
2018
}
2019
ret = dup2(devnull, STDIN_FILENO);
2020
if(ret == -1){
2021
perror_plus("dup2(devnull, STDIN_FILENO)");
2022
_exit(EX_OSERR);
2023
}
2024
ret = close(devnull);
2025
if(ret == -1){
2026
perror_plus("close");
2027
_exit(EX_OSERR);
2028
}
2029
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
2030
if(ret == -1){
2031
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
2032
_exit(EX_OSERR);
2033
}
2034
if(fexecve(hook_fd, (char *const []){ direntry->d_name, NULL },
2035
environ) == -1){
1673
if(fexecve(hookdir_fd, (char *const [])
1674
{ direntry->d_name, NULL }, environ) == -1){
2036
1675
perror_plus("fexecve");
2037
1676
_exit(EXIT_FAILURE);
2038
1677
}
2039
1678
} else {
2040
if(hook_pid == -1){
2041
perror_plus("fork");
2042
free(direntry);
2043
continue;
2044
}
2045
1679
int status;
2046
1680
if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){
2047
1681
perror_plus("waitpid");
2048
free(direntry);
2049
1682
continue;
2050
1683
}
2051
1684
if(WIFEXITED(status)){
2053
1686
fprintf_plus(stderr, "Warning: network hook \"%s\" exited"
2054
1687
" with status %d\n", direntry->d_name,
2055
1688
WEXITSTATUS(status));
2056
free(direntry);
2057
1689
continue;
2058
1690
}
2059
1691
} else if(WIFSIGNALED(status)){
2060
1692
fprintf_plus(stderr, "Warning: network hook \"%s\" died by"
2061
1693
" signal %d\n", direntry->d_name,
2062
1694
WTERMSIG(status));
2063
free(direntry);
2064
1695
continue;
2065
1696
} else {
2066
1697
fprintf_plus(stderr, "Warning: network hook \"%s\""
2067
1698
" crashed\n", direntry->d_name);
2068
free(direntry);
2069
1699
continue;
2070
1700
}
2071
1701
}
2073
1703
fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",
2074
1704
direntry->d_name);
2075
1705
}
2076
free(direntry);
2077
1706
}
2078
free(direntries);
2079
if(close(hookdir_fd) == -1){
1707
if((int)TEMP_FAILURE_RETRY(close(hookdir_fd)) == -1){
2080
1708
perror_plus("close");
2081
1709
} else {
2082
1710
hookdir_fd = -1;
2122
1750
}
2123
1751
2124
1752
if(quit_now){
2125
ret = close(sd);
1753
ret = (int)TEMP_FAILURE_RETRY(close(sd));
2126
1754
if(ret == -1){
2127
1755
perror_plus("close");
2128
1756
}
2138
1766
/* Raise privileges */
2139
1767
ret_errno = raise_privileges();
2140
1768
if(ret_errno != 0){
2141
errno = ret_errno;
2142
1769
perror_plus("Failed to raise privileges");
2143
1770
}
2144
1771
2178
1805
}
2179
1806
2180
1807
/* Close the socket */
2181
ret = close(sd);
1808
ret = (int)TEMP_FAILURE_RETRY(close(sd));
2182
1809
if(ret == -1){
2183
1810
perror_plus("close");
2184
1811
}
2248
1875
/* Raise privileges */
2249
1876
ret_errno = raise_privileges();
2250
1877
if(ret_errno != 0){
2251
errno = ret_errno;
2252
1878
perror_plus("Failed to raise privileges");
2253
1879
}
2254
1880
2266
1892
}
2267
1893
2268
1894
/* Close the socket */
2269
int ret = close(sd);
1895
int ret = (int)TEMP_FAILURE_RETRY(close(sd));
2270
1896
if(ret == -1){
2271
1897
perror_plus("close");
2272
1898
}
2287
1913
}
2288
1914
2289
1915
int main(int argc, char *argv[]){
2290
mandos_context mc = { .server = NULL, .dh_bits = 0,
2291
.priority = "SECURE256:!CTYPE-X.509"
2292
":+CTYPE-OPENPGP:!RSA:+SIGN-DSA-SHA256",
2293
.current_server = NULL, .interfaces = NULL,
2294
.interfaces_size = 0 };
1916
mandos_context mc = { .server = NULL, .dh_bits = 1024,
1917
.priority = "SECURE256:!CTYPE-X.509:"
1918
"+CTYPE-OPENPGP", .current_server = NULL,
1919
.interfaces = NULL, .interfaces_size = 0 };
2295
1920
AvahiSServiceBrowser *sb = NULL;
2296
1921
error_t ret_errno;
2297
1922
int ret;
2306
1931
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
2307
1932
const char *seckey = PATHDIR "/" SECKEY;
2308
1933
const char *pubkey = PATHDIR "/" PUBKEY;
2309
const char *dh_params_file = NULL;
2310
1934
char *interfaces_hooks = NULL;
2311
1935
2312
1936
bool gnutls_initialized = false;
2365
1989
.doc = "Bit length of the prime number used in the"
2366
1990
" Diffie-Hellman key exchange",
2367
1991
.group = 2 },
2368
{ .name = "dh-params", .key = 134,
2369
.arg = "FILE",
2370
.doc = "PEM-encoded PKCS#3 file with pre-generated parameters"
2371
" for the Diffie-Hellman key exchange",
2372
.group = 2 },
2373
1992
{ .name = "priority", .key = 130,
2374
1993
.arg = "STRING",
2375
1994
.doc = "GnuTLS priority string for the TLS handshake",
2430
2049
}
2431
2050
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
2432
2051
break;
2433
case 134: /* --dh-params */
2434
dh_params_file = arg;
2435
break;
2436
2052
case 130: /* --priority */
2437
2053
mc.priority = arg;
2438
2054
break;
2494
2110
goto end;
2495
2111
}
2496
2112
}
2497
2113
2498
2114
{
2499
2115
/* Work around Debian bug #633582:
2500
2116
<http://bugs.debian.org/633582> */
2524
2140
}
2525
2141
}
2526
2142
}
2527
close(seckey_fd);
2143
TEMP_FAILURE_RETRY(close(seckey_fd));
2528
2144
}
2529
2145
}
2530
2146
2531
2147
if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){
2532
2148
int pubkey_fd = open(pubkey, O_RDONLY);
2533
2149
if(pubkey_fd == -1){
2545
2161
}
2546
2162
}
2547
2163
}
2548
close(pubkey_fd);
2549
}
2550
}
2551
2552
if(dh_params_file != NULL
2553
and strcmp(dh_params_file, PATHDIR "/dhparams.pem" ) == 0){
2554
int dhparams_fd = open(dh_params_file, O_RDONLY);
2555
if(dhparams_fd == -1){
2556
perror_plus("open");
2557
} else {
2558
ret = (int)TEMP_FAILURE_RETRY(fstat(dhparams_fd, &st));
2559
if(ret == -1){
2560
perror_plus("fstat");
2561
} else {
2562
if(S_ISREG(st.st_mode)
2563
and st.st_uid == 0 and st.st_gid == 0){
2564
ret = fchown(dhparams_fd, uid, gid);
2565
if(ret == -1){
2566
perror_plus("fchown");
2567
}
2568
}
2569
}
2570
close(dhparams_fd);
2571
}
2572
}
2573
2164
TEMP_FAILURE_RETRY(close(pubkey_fd));
2165
}
2166
}
2167
2574
2168
/* Lower privileges */
2575
2169
ret_errno = lower_privileges();
2576
2170
if(ret_errno != 0){
2693
2287
2694
2288
/* If no interfaces were specified, make a list */
2695
2289
if(mc.interfaces == NULL){
2696
struct dirent **direntries = NULL;
2290
struct dirent **direntries;
2697
2291
/* Look for any good interfaces */
2698
2292
ret = scandir(sys_class_net, &direntries, good_interface,
2699
2293
alphasort);
2705
2299
if(ret_errno != 0){
2706
2300
errno = ret_errno;
2707
2301
perror_plus("argz_add");
2708
free(direntries[i]);
2709
2302
continue;
2710
2303
}
2711
2304
if(debug){
2712
2305
fprintf_plus(stderr, "Will use interface \"%s\"\n",
2713
2306
direntries[i]->d_name);
2714
2307
}
2715
free(direntries[i]);
2716
2308
}
2717
2309
free(direntries);
2718
2310
} else {
2719
if(ret == 0){
2720
free(direntries);
2721
}
2311
free(direntries);
2722
2312
fprintf_plus(stderr, "Could not find a network interface\n");
2723
2313
exitcode = EXIT_FAILURE;
2724
2314
goto end;
2750
2340
errno = bring_up_interface(interface, delay);
2751
2341
if(not interface_was_up){
2752
2342
if(errno != 0){
2753
fprintf_plus(stderr, "Failed to bring up interface \"%s\":"
2754
" %s\n", interface, strerror(errno));
2343
perror_plus("Failed to bring up interface");
2755
2344
} else {
2756
2345
errno = argz_add(&interfaces_to_take_down,
2757
2346
&interfaces_to_take_down_size,
2780
2369
goto end;
2781
2370
}
2782
2371
2783
ret = init_gnutls_global(pubkey, seckey, dh_params_file, &mc);
2372
ret = init_gnutls_global(pubkey, seckey, &mc);
2784
2373
if(ret == -1){
2785
2374
fprintf_plus(stderr, "init_gnutls_global failed\n");
2786
2375
exitcode = EX_UNAVAILABLE;
2989
2578
mc.current_server->prev->next = NULL;
2990
2579
while(mc.current_server != NULL){
2991
2580
server *next = mc.current_server->next;
2992
#ifdef __GNUC__
2993
#pragma GCC diagnostic push
2994
#pragma GCC diagnostic ignored "-Wcast-qual"
2995
#endif
2996
free((char *)(mc.current_server->ip));
2997
#ifdef __GNUC__
2998
#pragma GCC diagnostic pop
2999
#endif
3000
2581
free(mc.current_server);
3001
2582
mc.current_server = next;
3002
2583
}
3006
2587
{
3007
2588
ret_errno = raise_privileges();
3008
2589
if(ret_errno != 0){
3009
errno = ret_errno;
3010
2590
perror_plus("Failed to raise privileges");
3011
2591
} else {
3012
2592
3035
2615
3036
2616
ret_errno = lower_privileges_permanently();
3037
2617
if(ret_errno != 0){
3038
errno = ret_errno;
3039
2618
perror_plus("Failed to lower privileges permanently");
3040
2619
}
3041
2620
}
3046
2625
/* Removes the GPGME temp directory and all files inside */
3047
2626
if(tempdir != NULL){
3048
2627
struct dirent **direntries = NULL;
3049
int tempdir_fd = (int)TEMP_FAILURE_RETRY(open(tempdir, O_RDONLY
3050
| O_NOFOLLOW
3051
| O_DIRECTORY
3052
| O_PATH));
3053
if(tempdir_fd == -1){
3054
perror_plus("open");
3055
} else {
3056
#ifdef __GLIBC__
3057
#if __GLIBC_PREREQ(2, 15)
3058
int numentries = scandirat(tempdir_fd, ".", &direntries,
3059
notdotentries, alphasort);
3060
#else /* not __GLIBC_PREREQ(2, 15) */
3061
int numentries = scandir(tempdir, &direntries, notdotentries,
3062
alphasort);
3063
#endif /* not __GLIBC_PREREQ(2, 15) */
3064
#else /* not __GLIBC__ */
3065
int numentries = scandir(tempdir, &direntries, notdotentries,
3066
alphasort);
3067
#endif /* not __GLIBC__ */
3068
if(numentries >= 0){
3069
for(int i = 0; i < numentries; i++){
3070
ret = unlinkat(tempdir_fd, direntries[i]->d_name, 0);
3071
if(ret == -1){
3072
fprintf_plus(stderr, "unlinkat(open(\"%s\", O_RDONLY),"
3073
" \"%s\", 0): %s\n", tempdir,
3074
direntries[i]->d_name, strerror(errno));
3075
}
3076
free(direntries[i]);
3077
}
3078
3079
/* need to clean even if 0 because man page doesn't specify */
3080
free(direntries);
3081
if(numentries == -1){
3082
perror_plus("scandir");
3083
}
3084
ret = rmdir(tempdir);
3085
if(ret == -1 and errno != ENOENT){
3086
perror_plus("rmdir");
3087
}
2628
struct dirent *direntry = NULL;
2629
int numentries = scandir(tempdir, &direntries, notdotentries,
2630
alphasort);
2631
if(numentries > 0){
2632
for(int i = 0; i < numentries; i++){
2633
direntry = direntries[i];
2634
char *fullname = NULL;
2635
ret = asprintf(&fullname, "%s/%s", tempdir,
2636
direntry->d_name);
2637
if(ret < 0){
2638
perror_plus("asprintf");
2639
continue;
2640
}
2641
ret = remove(fullname);
2642
if(ret == -1){
2643
fprintf_plus(stderr, "remove(\"%s\"): %s\n", fullname,
2644
strerror(errno));
2645
}
2646
free(fullname);
3088
2647
}
3089
close(tempdir_fd);
2648
}
2649
2650
/* need to clean even if 0 because man page doesn't specify */
2651
free(direntries);
2652
if(numentries == -1){
2653
perror_plus("scandir");
2654
}
2655
ret = rmdir(tempdir);
2656
if(ret == -1 and errno != ENOENT){
2657
perror_plus("rmdir");
3090
2658
}
3091
2659
}
3092
2660
Loggerhead is a web-based interface for Breezy
Version: 2.0.2.dev0