26
26
* along with this program. If not, see
27
27
* <http://www.gnu.org/licenses/>.
29
* Contact the authors at <mandos@fukt.bsnet.se>.
29
* Contact the authors at <mandos@recompile.se>.
32
32
/* Needed by GPGME, specifically gpgme_data_seek() */
33
#ifndef _LARGEFILE_SOURCE
33
34
#define _LARGEFILE_SOURCE
36
#ifndef _FILE_OFFSET_BITS
34
37
#define _FILE_OFFSET_BITS 64
36
40
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
38
42
#include <stdio.h> /* fprintf(), stderr, fwrite(),
39
stdout, ferror(), sscanf(),
43
stdout, ferror(), remove() */
41
44
#include <stdint.h> /* uint16_t, uint32_t */
42
45
#include <stddef.h> /* NULL, size_t, ssize_t */
43
#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
45
#include <stdbool.h> /* bool, true */
46
#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),
48
#include <stdbool.h> /* bool, false, true */
46
49
#include <string.h> /* memset(), strcmp(), strlen(),
47
50
strerror(), asprintf(), strcpy() */
48
#include <sys/ioctl.h> /* ioctl */
51
#include <sys/ioctl.h> /* ioctl */
49
52
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
50
53
sockaddr_in6, PF_INET6,
51
SOCK_STREAM, INET6_ADDRSTRLEN,
52
uid_t, gid_t, open(), opendir(),
54
#include <sys/stat.h> /* open() */
54
SOCK_STREAM, uid_t, gid_t, open(),
56
#include <sys/stat.h> /* open(), S_ISREG */
55
57
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
56
struct in6_addr, inet_pton(),
58
inet_pton(), connect() */
58
59
#include <fcntl.h> /* open() */
59
60
#include <dirent.h> /* opendir(), struct dirent, readdir()
61
#include <inttypes.h> /* PRIu16, intmax_t, SCNdMAX */
62
#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,
62
64
#include <assert.h> /* assert() */
63
#include <errno.h> /* perror(), errno */
64
#include <time.h> /* nanosleep(), time() */
65
#include <errno.h> /* perror(), errno,
66
program_invocation_short_name */
67
#include <time.h> /* nanosleep(), time(), sleep() */
65
68
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
66
69
SIOCSIFFLAGS, if_indextoname(),
67
70
if_nametoindex(), IF_NAMESIZE */
68
#include <netinet/in.h>
71
#include <netinet/in.h> /* IN6_IS_ADDR_LINKLOCAL,
72
INET_ADDRSTRLEN, INET6_ADDRSTRLEN
69
74
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
70
getuid(), getgid(), setuid(),
72
#include <arpa/inet.h> /* inet_pton(), htons */
73
#include <iso646.h> /* not, and, or */
75
getuid(), getgid(), seteuid(),
76
setgid(), pause(), _exit() */
77
#include <arpa/inet.h> /* inet_pton(), htons, inet_ntop() */
78
#include <iso646.h> /* not, or, and */
74
79
#include <argp.h> /* struct argp_option, error_t, struct
75
80
argp_state, struct argp,
76
81
argp_parse(), ARGP_KEY_ARG,
77
82
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
83
#include <signal.h> /* sigemptyset(), sigaddset(),
84
sigaction(), SIGTERM, sig_atomic_t,
86
#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,
87
EX_NOHOST, EX_IOERR, EX_PROTOCOL */
88
#include <sys/wait.h> /* waitpid(), WIFEXITED(),
89
WEXITSTATUS(), WTERMSIG() */
90
#include <grp.h> /* setgroups() */
79
93
#include <sys/klog.h> /* klogctl() */
94
#endif /* __linux__ */
83
97
/* All Avahi types, constants and functions
160
254
* Helper function to insert pub and seckey to the engine keyring.
162
256
bool import_key(const char *filename){
164
259
gpgme_data_t pgp_data;
166
261
fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
172
267
rc = gpgme_data_new_from_fd(&pgp_data, fd);
173
268
if(rc != GPG_ERR_NO_ERROR){
174
fprintf(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
175
gpgme_strsource(rc), gpgme_strerror(rc));
269
fprintf_plus(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
270
gpgme_strsource(rc), gpgme_strerror(rc));
179
rc = gpgme_op_import(mc->ctx, pgp_data);
274
rc = gpgme_op_import(mc.ctx, pgp_data);
180
275
if(rc != GPG_ERR_NO_ERROR){
181
fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
182
gpgme_strsource(rc), gpgme_strerror(rc));
276
fprintf_plus(stderr, "bad gpgme_op_import: %s: %s\n",
277
gpgme_strsource(rc), gpgme_strerror(rc));
186
281
ret = (int)TEMP_FAILURE_RETRY(close(fd));
283
perror_plus("close");
190
285
gpgme_data_release(pgp_data);
195
fprintf(stderr, "Initialize gpgme\n");
290
fprintf_plus(stderr, "Initializing GPGME\n");
199
294
gpgme_check_version(NULL);
200
295
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
201
296
if(rc != GPG_ERR_NO_ERROR){
202
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
203
gpgme_strsource(rc), gpgme_strerror(rc));
297
fprintf_plus(stderr, "bad gpgme_engine_check_version: %s: %s\n",
298
gpgme_strsource(rc), gpgme_strerror(rc));
207
/* Set GPGME home directory for the OpenPGP engine only */
302
/* Set GPGME home directory for the OpenPGP engine only */
208
303
rc = gpgme_get_engine_info(&engine_info);
209
304
if(rc != GPG_ERR_NO_ERROR){
210
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
211
gpgme_strsource(rc), gpgme_strerror(rc));
305
fprintf_plus(stderr, "bad gpgme_get_engine_info: %s: %s\n",
306
gpgme_strsource(rc), gpgme_strerror(rc));
214
309
while(engine_info != NULL){
254
350
ssize_t plaintext_length = 0;
257
fprintf(stderr, "Trying to decrypt OpenPGP data\n");
353
fprintf_plus(stderr, "Trying to decrypt OpenPGP data\n");
260
356
/* Create new GPGME data buffer from memory cryptotext */
261
357
rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,
263
359
if(rc != GPG_ERR_NO_ERROR){
264
fprintf(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
265
gpgme_strsource(rc), gpgme_strerror(rc));
360
fprintf_plus(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
361
gpgme_strsource(rc), gpgme_strerror(rc));
269
365
/* Create new empty GPGME data buffer for the plaintext */
270
366
rc = gpgme_data_new(&dh_plain);
271
367
if(rc != GPG_ERR_NO_ERROR){
272
fprintf(stderr, "bad gpgme_data_new: %s: %s\n",
273
gpgme_strsource(rc), gpgme_strerror(rc));
368
fprintf_plus(stderr, "Mandos plugin mandos-client: "
369
"bad gpgme_data_new: %s: %s\n",
370
gpgme_strsource(rc), gpgme_strerror(rc));
274
371
gpgme_data_release(dh_crypto);
278
375
/* Decrypt data from the cryptotext data buffer to the plaintext
280
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
377
rc = gpgme_op_decrypt(mc.ctx, dh_crypto, dh_plain);
281
378
if(rc != GPG_ERR_NO_ERROR){
282
fprintf(stderr, "bad gpgme_op_decrypt: %s: %s\n",
283
gpgme_strsource(rc), gpgme_strerror(rc));
379
fprintf_plus(stderr, "bad gpgme_op_decrypt: %s: %s\n",
380
gpgme_strsource(rc), gpgme_strerror(rc));
284
381
plaintext_length = -1;
286
383
gpgme_decrypt_result_t result;
287
result = gpgme_op_decrypt_result(mc->ctx);
384
result = gpgme_op_decrypt_result(mc.ctx);
288
385
if(result == NULL){
289
fprintf(stderr, "gpgme_op_decrypt_result failed\n");
386
fprintf_plus(stderr, "gpgme_op_decrypt_result failed\n");
291
fprintf(stderr, "Unsupported algorithm: %s\n",
292
result->unsupported_algorithm);
293
fprintf(stderr, "Wrong key usage: %u\n",
294
result->wrong_key_usage);
388
fprintf_plus(stderr, "Unsupported algorithm: %s\n",
389
result->unsupported_algorithm);
390
fprintf_plus(stderr, "Wrong key usage: %u\n",
391
result->wrong_key_usage);
295
392
if(result->file_name != NULL){
296
fprintf(stderr, "File name: %s\n", result->file_name);
393
fprintf_plus(stderr, "File name: %s\n", result->file_name);
298
395
gpgme_recipient_t recipient;
299
396
recipient = result->recipients;
301
while(recipient != NULL){
302
fprintf(stderr, "Public key algorithm: %s\n",
303
gpgme_pubkey_algo_name(recipient->pubkey_algo));
304
fprintf(stderr, "Key ID: %s\n", recipient->keyid);
305
fprintf(stderr, "Secret key available: %s\n",
306
recipient->status == GPG_ERR_NO_SECKEY
308
recipient = recipient->next;
397
while(recipient != NULL){
398
fprintf_plus(stderr, "Public key algorithm: %s\n",
399
gpgme_pubkey_algo_name
400
(recipient->pubkey_algo));
401
fprintf_plus(stderr, "Key ID: %s\n", recipient->keyid);
402
fprintf_plus(stderr, "Secret key available: %s\n",
403
recipient->status == GPG_ERR_NO_SECKEY
405
recipient = recipient->next;
409
504
/* OpenPGP credentials */
410
gnutls_certificate_allocate_credentials(&mc->cred);
505
ret = gnutls_certificate_allocate_credentials(&mc.cred);
411
506
if(ret != GNUTLS_E_SUCCESS){
412
fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning
416
safer_gnutls_strerror(ret));
507
fprintf_plus(stderr, "GnuTLS memory error: %s\n",
508
safer_gnutls_strerror(ret));
417
509
gnutls_global_deinit();
422
fprintf(stderr, "Attempting to use OpenPGP public key %s and"
423
" secret key %s as GnuTLS credentials\n", pubkeyfilename,
514
fprintf_plus(stderr, "Attempting to use OpenPGP public key %s and"
515
" secret key %s as GnuTLS credentials\n",
427
520
ret = gnutls_certificate_set_openpgp_key_file
428
(mc->cred, pubkeyfilename, seckeyfilename,
521
(mc.cred, pubkeyfilename, seckeyfilename,
429
522
GNUTLS_OPENPGP_FMT_BASE64);
430
523
if(ret != GNUTLS_E_SUCCESS){
432
"Error[%d] while reading the OpenPGP key pair ('%s',"
433
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
434
fprintf(stderr, "The GnuTLS error is: %s\n",
435
safer_gnutls_strerror(ret));
525
"Error[%d] while reading the OpenPGP key pair ('%s',"
526
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
527
fprintf_plus(stderr, "The GnuTLS error is: %s\n",
528
safer_gnutls_strerror(ret));
439
532
/* GnuTLS server initialization */
440
ret = gnutls_dh_params_init(&mc->dh_params);
533
ret = gnutls_dh_params_init(&mc.dh_params);
441
534
if(ret != GNUTLS_E_SUCCESS){
442
fprintf(stderr, "Error in GnuTLS DH parameter initialization:"
443
" %s\n", safer_gnutls_strerror(ret));
535
fprintf_plus(stderr, "Error in GnuTLS DH parameter"
536
" initialization: %s\n",
537
safer_gnutls_strerror(ret));
446
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
540
ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);
447
541
if(ret != GNUTLS_E_SUCCESS){
448
fprintf(stderr, "Error in GnuTLS prime generation: %s\n",
449
safer_gnutls_strerror(ret));
542
fprintf_plus(stderr, "Error in GnuTLS prime generation: %s\n",
543
safer_gnutls_strerror(ret));
453
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
547
gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);
459
gnutls_certificate_free_credentials(mc->cred);
553
gnutls_certificate_free_credentials(mc.cred);
460
554
gnutls_global_deinit();
461
gnutls_dh_params_deinit(mc->dh_params);
555
gnutls_dh_params_deinit(mc.dh_params);
465
static int init_gnutls_session(mandos_context *mc,
466
gnutls_session_t *session){
559
static int init_gnutls_session(gnutls_session_t *session){
468
561
/* GnuTLS session creation */
469
ret = gnutls_init(session, GNUTLS_SERVER);
563
ret = gnutls_init(session, GNUTLS_SERVER);
567
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
470
568
if(ret != GNUTLS_E_SUCCESS){
471
fprintf(stderr, "Error in GnuTLS session initialization: %s\n",
472
safer_gnutls_strerror(ret));
570
"Error in GnuTLS session initialization: %s\n",
571
safer_gnutls_strerror(ret));
477
ret = gnutls_priority_set_direct(*session, mc->priority, &err);
577
ret = gnutls_priority_set_direct(*session, mc.priority, &err);
579
gnutls_deinit(*session);
582
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
478
583
if(ret != GNUTLS_E_SUCCESS){
479
fprintf(stderr, "Syntax error at: %s\n", err);
480
fprintf(stderr, "GnuTLS error: %s\n",
481
safer_gnutls_strerror(ret));
584
fprintf_plus(stderr, "Syntax error at: %s\n", err);
585
fprintf_plus(stderr, "GnuTLS error: %s\n",
586
safer_gnutls_strerror(ret));
482
587
gnutls_deinit(*session);
487
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
593
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
596
gnutls_deinit(*session);
599
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
489
600
if(ret != GNUTLS_E_SUCCESS){
490
fprintf(stderr, "Error setting GnuTLS credentials: %s\n",
491
safer_gnutls_strerror(ret));
601
fprintf_plus(stderr, "Error setting GnuTLS credentials: %s\n",
602
safer_gnutls_strerror(ret));
492
603
gnutls_deinit(*session);
496
607
/* ignore client certificate if any. */
497
gnutls_certificate_server_set_request(*session,
608
gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);
500
gnutls_dh_set_prime_bits(*session, mc->dh_bits);
610
gnutls_dh_set_prime_bits(*session, mc.dh_bits);
509
619
/* Called when a Mandos server is found */
510
620
static int start_mandos_communication(const char *ip, uint16_t port,
511
621
AvahiIfIndex if_index,
623
int ret, tcp_sd = -1;
515
union { struct sockaddr in; struct sockaddr_in6 in6; } to;
626
struct sockaddr_in in;
627
struct sockaddr_in6 in6;
516
629
char *buffer = NULL;
517
char *decrypted_buffer;
630
char *decrypted_buffer = NULL;
518
631
size_t buffer_length = 0;
519
632
size_t buffer_capacity = 0;
520
ssize_t decrypted_buffer_size;
523
char interface[IF_NAMESIZE];
524
635
gnutls_session_t session;
526
ret = init_gnutls_session(mc, &session);
636
int pf; /* Protocol family */
653
fprintf_plus(stderr, "Bad address family: %d\n", af);
658
ret = init_gnutls_session(&session);
532
fprintf(stderr, "Setting up a tcp connection to %s, port %" PRIu16
664
fprintf_plus(stderr, "Setting up a TCP connection to %s, port %"
665
PRIu16 "\n", ip, port);
536
tcp_sd = socket(PF_INET6, SOCK_STREAM, 0);
668
tcp_sd = socket(pf, SOCK_STREAM, 0);
671
perror_plus("socket");
543
if(if_indextoname((unsigned int)if_index, interface) == NULL){
544
perror("if_indextoname");
547
fprintf(stderr, "Binding to interface %s\n", interface);
550
681
memset(&to, 0, sizeof(to));
551
to.in6.sin6_family = AF_INET6;
552
/* It would be nice to have a way to detect if we were passed an
553
IPv4 address here. Now we assume an IPv6 address. */
554
ret = inet_pton(AF_INET6, ip, &to.in6.sin6_addr);
683
to.in6.sin6_family = (sa_family_t)af;
684
ret = inet_pton(af, ip, &to.in6.sin6_addr);
686
to.in.sin_family = (sa_family_t)af;
687
ret = inet_pton(af, ip, &to.in.sin_addr);
691
perror_plus("inet_pton");
560
fprintf(stderr, "Bad address: %s\n", ip);
697
fprintf_plus(stderr, "Bad address: %s\n", ip);
563
to.in6.sin6_port = htons(port); /* Spurious warnings from
702
to.in6.sin6_port = htons(port); /* Spurious warnings from
704
-Wunreachable-code */
706
if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */
707
(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower and
709
if(if_index == AVAHI_IF_UNSPEC){
710
fprintf_plus(stderr, "An IPv6 link-local address is"
711
" incomplete without a network interface\n");
715
/* Set the network interface number as scope */
716
to.in6.sin6_scope_id = (uint32_t)if_index;
719
to.in.sin_port = htons(port); /* Spurious warnings from
565
721
-Wunreachable-code */
567
to.in6.sin6_scope_id = (uint32_t)if_index;
570
fprintf(stderr, "Connection to: %s, port %" PRIu16 "\n", ip,
572
char addrstr[INET6_ADDRSTRLEN] = "";
573
if(inet_ntop(to.in6.sin6_family, &(to.in6.sin6_addr), addrstr,
574
sizeof(addrstr)) == NULL){
730
if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){
731
char interface[IF_NAMESIZE];
732
if(if_indextoname((unsigned int)if_index, interface) == NULL){
733
perror_plus("if_indextoname");
735
fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIu16
736
"\n", ip, interface, port);
739
fprintf_plus(stderr, "Connection to: %s, port %" PRIu16 "\n",
742
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
743
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
746
pcret = inet_ntop(af, &(to.in6.sin6_addr), addrstr,
749
pcret = inet_ntop(af, &(to.in.sin_addr), addrstr,
753
perror_plus("inet_ntop");
577
755
if(strcmp(addrstr, ip) != 0){
578
fprintf(stderr, "Canonical address form: %s\n", addrstr);
756
fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);
583
ret = connect(tcp_sd, &to.in, sizeof(to));
767
ret = connect(tcp_sd, &to.in6, sizeof(to));
769
ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */
772
if ((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){
774
perror_plus("connect");
589
785
const char *out = mandos_protocol_version;
815
1092
case AVAHI_BROWSER_ALL_FOR_NOW:
816
1093
case AVAHI_BROWSER_CACHE_EXHAUSTED:
818
fprintf(stderr, "No Mandos server found, still searching...\n");
1095
fprintf_plus(stderr, "No Mandos server found, still"
1102
/* Signal handler that stops main loop after SIGTERM */
1103
static void handle_sigterm(int sig){
1108
signal_received = sig;
1109
int old_errno = errno;
1110
/* set main loop to exit */
1111
if(mc.simple_poll != NULL){
1112
avahi_simple_poll_quit(mc.simple_poll);
1117
bool get_flags(const char *ifname, struct ifreq *ifr){
1120
int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1122
perror_plus("socket");
1125
strcpy(ifr->ifr_name, ifname);
1126
ret = ioctl(s, SIOCGIFFLAGS, ifr);
1129
perror_plus("ioctl SIOCGIFFLAGS");
1136
bool good_flags(const char *ifname, const struct ifreq *ifr){
1138
/* Reject the loopback device */
1139
if(ifr->ifr_flags & IFF_LOOPBACK){
1141
fprintf_plus(stderr, "Rejecting loopback interface \"%s\"\n",
1146
/* Accept point-to-point devices only if connect_to is specified */
1147
if(connect_to != NULL and (ifr->ifr_flags & IFF_POINTOPOINT)){
1149
fprintf_plus(stderr, "Accepting point-to-point interface"
1150
" \"%s\"\n", ifname);
1154
/* Otherwise, reject non-broadcast-capable devices */
1155
if(not (ifr->ifr_flags & IFF_BROADCAST)){
1157
fprintf_plus(stderr, "Rejecting non-broadcast interface"
1158
" \"%s\"\n", ifname);
1162
/* Reject non-ARP interfaces (including dummy interfaces) */
1163
if(ifr->ifr_flags & IFF_NOARP){
1165
fprintf_plus(stderr, "Rejecting non-ARP interface \"%s\"\n",
1171
/* Accept this device */
1173
fprintf_plus(stderr, "Interface \"%s\" is good\n", ifname);
1179
* This function determines if a directory entry in /sys/class/net
1180
* corresponds to an acceptable network device.
1181
* (This function is passed to scandir(3) as a filter function.)
1183
int good_interface(const struct dirent *if_entry){
1184
if(if_entry->d_name[0] == '.'){
1189
if(not get_flags(if_entry->d_name, &ifr)){
1191
fprintf_plus(stderr, "Failed to get flags for interface "
1192
"\"%s\"\n", if_entry->d_name);
1197
if(not good_flags(if_entry->d_name, &ifr)){
1204
* This function determines if a directory entry in /sys/class/net
1205
* corresponds to an acceptable network device which is up.
1206
* (This function is passed to scandir(3) as a filter function.)
1208
int up_interface(const struct dirent *if_entry){
1209
if(if_entry->d_name[0] == '.'){
1214
if(not get_flags(if_entry->d_name, &ifr)){
1216
fprintf_plus(stderr, "Failed to get flags for interface "
1217
"\"%s\"\n", if_entry->d_name);
1222
/* Reject down interfaces */
1223
if(not (ifr.ifr_flags & IFF_UP)){
1225
fprintf_plus(stderr, "Rejecting down interface \"%s\"\n",
1231
/* Reject non-running interfaces */
1232
if(not (ifr.ifr_flags & IFF_RUNNING)){
1234
fprintf_plus(stderr, "Rejecting non-running interface \"%s\"\n",
1240
if(not good_flags(if_entry->d_name, &ifr)){
1246
int notdotentries(const struct dirent *direntry){
1247
/* Skip "." and ".." */
1248
if(direntry->d_name[0] == '.'
1249
and (direntry->d_name[1] == '\0'
1250
or (direntry->d_name[1] == '.'
1251
and direntry->d_name[2] == '\0'))){
1257
/* Is this directory entry a runnable program? */
1258
int runnable_hook(const struct dirent *direntry){
1263
if((direntry->d_name)[0] == '\0'){
1268
sret = strspn(direntry->d_name, "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
1269
"abcdefghijklmnopqrstuvwxyz"
1272
if((direntry->d_name)[sret] != '\0'){
1273
/* Contains non-allowed characters */
1275
fprintf_plus(stderr, "Ignoring hook \"%s\" with bad name\n",
1281
char *fullname = NULL;
1282
ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);
1284
perror_plus("asprintf");
1288
ret = stat(fullname, &st);
1291
perror_plus("Could not stat hook");
1295
if(not (S_ISREG(st.st_mode))){
1296
/* Not a regular file */
1298
fprintf_plus(stderr, "Ignoring hook \"%s\" - not a file\n",
1303
if(not (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))){
1304
/* Not executable */
1306
fprintf_plus(stderr, "Ignoring hook \"%s\" - not executable\n",
1312
fprintf_plus(stderr, "Hook \"%s\" is acceptable\n",
1318
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){
1320
struct timespec now;
1321
struct timespec waited_time;
1322
intmax_t block_time;
1325
if(mc.current_server == NULL){
1327
fprintf_plus(stderr, "Wait until first server is found."
1330
ret = avahi_simple_poll_iterate(s, -1);
1333
fprintf_plus(stderr, "Check current_server if we should run"
1336
/* the current time */
1337
ret = clock_gettime(CLOCK_MONOTONIC, &now);
1339
perror_plus("clock_gettime");
1342
/* Calculating in ms how long time between now and server
1343
who we visted longest time ago. Now - last seen. */
1344
waited_time.tv_sec = (now.tv_sec
1345
- mc.current_server->last_seen.tv_sec);
1346
waited_time.tv_nsec = (now.tv_nsec
1347
- mc.current_server->last_seen.tv_nsec);
1348
/* total time is 10s/10,000ms.
1349
Converting to s from ms by dividing by 1,000,
1350
and ns to ms by dividing by 1,000,000. */
1351
block_time = ((retry_interval
1352
- ((intmax_t)waited_time.tv_sec * 1000))
1353
- ((intmax_t)waited_time.tv_nsec / 1000000));
1356
fprintf_plus(stderr, "Blocking for %" PRIdMAX " ms\n",
1360
if(block_time <= 0){
1361
ret = start_mandos_communication(mc.current_server->ip,
1362
mc.current_server->port,
1363
mc.current_server->if_index,
1364
mc.current_server->af);
1366
avahi_simple_poll_quit(mc.simple_poll);
1369
ret = clock_gettime(CLOCK_MONOTONIC,
1370
&mc.current_server->last_seen);
1372
perror_plus("clock_gettime");
1375
mc.current_server = mc.current_server->next;
1376
block_time = 0; /* Call avahi to find new Mandos
1377
servers, but don't block */
1380
ret = avahi_simple_poll_iterate(s, (int)block_time);
1383
if (ret > 0 or errno != EINTR){
1384
return (ret != 1) ? ret : 0;
1390
bool run_network_hooks(const char *mode, const char *interface,
1392
struct dirent **direntries;
1393
struct dirent *direntry;
1395
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1398
perror_plus("scandir");
1400
int devnull = open("/dev/null", O_RDONLY);
1401
for(int i = 0; i < numhooks; i++){
1402
direntry = direntries[i];
1403
char *fullname = NULL;
1404
ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);
1406
perror_plus("asprintf");
1410
fprintf_plus(stderr, "Running network hook \"%s\"\n",
1413
pid_t hook_pid = fork();
1416
/* Raise privileges */
1420
perror_plus("seteuid");
1422
/* Raise privileges even more */
1426
perror_plus("setuid");
1432
perror_plus("setgid");
1434
/* Reset supplementary groups */
1436
ret = setgroups(0, NULL);
1438
perror_plus("setgroups");
1440
dup2(devnull, STDIN_FILENO);
1442
dup2(STDERR_FILENO, STDOUT_FILENO);
1443
ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);
1445
perror_plus("setenv");
1448
ret = setenv("DEVICE", interface, 1);
1450
perror_plus("setenv");
1453
ret = setenv("VERBOSITY", debug ? "1" : "0", 1);
1455
perror_plus("setenv");
1458
ret = setenv("MODE", mode, 1);
1460
perror_plus("setenv");
1464
ret = asprintf(&delaystring, "%f", delay);
1466
perror_plus("asprintf");
1469
ret = setenv("DELAY", delaystring, 1);
1472
perror_plus("setenv");
1476
if(connect_to != NULL){
1477
ret = setenv("CONNECT", connect_to);
1479
perror_plus("setenv");
1483
if(execl(fullname, direntry->d_name, mode, NULL) == -1){
1484
perror_plus("execl");
1485
_exit(EXIT_FAILURE);
1489
if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){
1490
perror_plus("waitpid");
1494
if(WIFEXITED(status)){
1495
if(WEXITSTATUS(status) != 0){
1496
fprintf_plus(stderr, "Warning: network hook \"%s\" exited"
1497
" with status %d\n", direntry->d_name,
1498
WEXITSTATUS(status));
1502
} else if(WIFSIGNALED(status)){
1503
fprintf_plus(stderr, "Warning: network hook \"%s\" died by"
1504
" signal %d\n", direntry->d_name,
1509
fprintf_plus(stderr, "Warning: network hook \"%s\""
1510
" crashed\n", direntry->d_name);
1517
fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",
824
1526
int main(int argc, char *argv[]){
825
1527
AvahiSServiceBrowser *sb = NULL;
828
1530
intmax_t tmpmax;
830
1532
int exitcode = EXIT_SUCCESS;
831
const char *interface = "eth0";
1533
const char *interface = "";
832
1534
struct ifreq network;
1536
bool take_down_interface = false;
836
char *connect_to = NULL;
837
1539
char tempdir[] = "/tmp/mandosXXXXXX";
838
1540
bool tempdir_created = false;
839
1541
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
840
1542
const char *seckey = PATHDIR "/" SECKEY;
841
1543
const char *pubkey = PATHDIR "/" PUBKEY;
843
mandos_context mc = { .simple_poll = NULL, .server = NULL,
844
.dh_bits = 1024, .priority = "SECURE256"
845
":!CTYPE-X.509:+CTYPE-OPENPGP" };
846
1545
bool gnutls_initialized = false;
847
1546
bool gpgme_initialized = false;
1548
double retry_interval = 10; /* 10s between trying a server and
1549
retrying the same server again */
1551
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
1552
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
1557
/* Lower any group privileges we might have, just to be safe */
1561
perror_plus("setgid");
1564
/* Lower user privileges (temporarily) */
1568
perror_plus("seteuid");
851
1576
struct argp_option options[] = {
915
1658
mc.priority = arg;
917
1660
case 131: /* --delay */
918
ret = sscanf(arg, "%lf%n", &delay, &numchars);
919
if(ret < 1 or arg[numchars] != '\0'){
920
fprintf(stderr, "Bad delay\n");
1662
delay = strtof(arg, &tmp);
1663
if(errno != 0 or tmp == arg or *tmp != '\0'){
1664
argp_error(state, "Bad delay");
1666
case 132: /* --retry */
1668
retry_interval = strtod(arg, &tmp);
1669
if(errno != 0 or tmp == arg or *tmp != '\0'
1670
or (retry_interval * 1000) > INT_MAX
1671
or retry_interval < 0){
1672
argp_error(state, "Bad retry interval");
1675
case 133: /* --network-hook-dir */
1679
* These reproduce what we would get without ARGP_NO_HELP
1681
case '?': /* --help */
1682
argp_state_help(state, state->out_stream,
1683
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
1684
& ~(unsigned int)ARGP_HELP_EXIT_OK);
1685
case -3: /* --usage */
1686
argp_state_help(state, state->out_stream,
1687
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
1688
case 'V': /* --version */
1689
fprintf_plus(state->out_stream, "%s\n", argp_program_version);
1690
exit(argp_err_exit_status);
929
1693
return ARGP_ERR_UNKNOWN;
934
1698
struct argp argp = { .options = options, .parser = parse_opt,
936
1700
.doc = "Mandos client -- Get and decrypt"
937
1701
" passwords from a Mandos server" };
938
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
939
if(ret == ARGP_ERR_UNKNOWN){
940
fprintf(stderr, "Unknown error while parsing arguments\n");
1702
ret = argp_parse(&argp, argc, argv,
1703
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
1710
perror_plus("argp_parse");
1711
exitcode = EX_OSERR;
1714
exitcode = EX_USAGE;
1720
/* Work around Debian bug #633582:
1721
<http://bugs.debian.org/633582> */
1723
/* Re-raise priviliges */
1727
perror_plus("seteuid");
1731
if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){
1732
int seckey_fd = open(seckey, O_RDONLY);
1733
if(seckey_fd == -1){
1734
perror_plus("open");
1736
ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));
1738
perror_plus("fstat");
1740
if(S_ISREG(st.st_mode)
1741
and st.st_uid == 0 and st.st_gid == 0){
1742
ret = fchown(seckey_fd, uid, gid);
1744
perror_plus("fchown");
1748
TEMP_FAILURE_RETRY(close(seckey_fd));
1752
if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){
1753
int pubkey_fd = open(pubkey, O_RDONLY);
1754
if(pubkey_fd == -1){
1755
perror_plus("open");
1757
ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));
1759
perror_plus("fstat");
1761
if(S_ISREG(st.st_mode)
1762
and st.st_uid == 0 and st.st_gid == 0){
1763
ret = fchown(pubkey_fd, uid, gid);
1765
perror_plus("fchown");
1769
TEMP_FAILURE_RETRY(close(pubkey_fd));
1773
/* Lower privileges */
1777
perror_plus("seteuid");
1782
/* Run network hooks */
1783
if(not run_network_hooks("start", interface, delay)){
1788
avahi_set_log_function(empty_log);
1791
if(interface[0] == '\0'){
1792
struct dirent **direntries;
1793
/* First look for interfaces that are up */
1794
ret = scandir(sys_class_net, &direntries, up_interface,
1797
/* No up interfaces, look for any good interfaces */
1799
ret = scandir(sys_class_net, &direntries, good_interface,
1803
/* Pick the first interface returned */
1804
interface = strdup(direntries[0]->d_name);
1806
fprintf_plus(stderr, "Using interface \"%s\"\n", interface);
1808
if(interface == NULL){
1809
perror_plus("malloc");
1811
exitcode = EXIT_FAILURE;
1817
fprintf_plus(stderr, "Could not find a network interface\n");
941
1818
exitcode = EXIT_FAILURE;
1823
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
1824
from the signal handler */
1825
/* Initialize the pseudo-RNG for Avahi */
1826
srand((unsigned int) time(NULL));
1827
mc.simple_poll = avahi_simple_poll_new();
1828
if(mc.simple_poll == NULL){
1829
fprintf_plus(stderr,
1830
"Avahi: Failed to create simple poll object.\n");
1831
exitcode = EX_UNAVAILABLE;
1835
sigemptyset(&sigterm_action.sa_mask);
1836
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
1838
perror_plus("sigaddset");
1839
exitcode = EX_OSERR;
1842
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
1844
perror_plus("sigaddset");
1845
exitcode = EX_OSERR;
1848
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
1850
perror_plus("sigaddset");
1851
exitcode = EX_OSERR;
1854
/* Need to check if the handler is SIG_IGN before handling:
1855
| [[info:libc:Initial Signal Actions]] |
1856
| [[info:libc:Basic Signal Handling]] |
1858
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1860
perror_plus("sigaction");
1863
if(old_sigterm_action.sa_handler != SIG_IGN){
1864
ret = sigaction(SIGINT, &sigterm_action, NULL);
1866
perror_plus("sigaction");
1867
exitcode = EX_OSERR;
1871
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1873
perror_plus("sigaction");
1876
if(old_sigterm_action.sa_handler != SIG_IGN){
1877
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1879
perror_plus("sigaction");
1880
exitcode = EX_OSERR;
1884
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1886
perror_plus("sigaction");
1889
if(old_sigterm_action.sa_handler != SIG_IGN){
1890
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1892
perror_plus("sigaction");
1893
exitcode = EX_OSERR;
946
1898
/* If the interface is down, bring it up */
1899
if(strcmp(interface, "none") != 0){
1900
if_index = (AvahiIfIndex) if_nametoindex(interface);
1902
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1903
exitcode = EX_UNAVAILABLE;
1911
/* Re-raise priviliges */
1915
perror_plus("seteuid");
948
1918
#ifdef __linux__
949
1919
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
950
messages to mess up the prompt */
1920
messages about the network interface to mess up the prompt */
951
1921
ret = klogctl(8, NULL, 5);
1922
bool restore_loglevel = true;
1924
restore_loglevel = false;
1925
perror_plus("klogctl");
1927
#endif /* __linux__ */
957
1929
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
960
exitcode = EXIT_FAILURE;
1931
perror_plus("socket");
1932
exitcode = EX_OSERR;
961
1933
#ifdef __linux__
962
ret = klogctl(7, NULL, 0);
1934
if(restore_loglevel){
1935
ret = klogctl(7, NULL, 0);
1937
perror_plus("klogctl");
1940
#endif /* __linux__ */
1941
/* Lower privileges */
1945
perror_plus("seteuid");
969
1949
strcpy(network.ifr_name, interface);
970
1950
ret = ioctl(sd, SIOCGIFFLAGS, &network);
972
perror("ioctl SIOCGIFFLAGS");
1952
perror_plus("ioctl SIOCGIFFLAGS");
973
1953
#ifdef __linux__
974
ret = klogctl(7, NULL, 0);
1954
if(restore_loglevel){
1955
ret = klogctl(7, NULL, 0);
1957
perror_plus("klogctl");
1960
#endif /* __linux__ */
1961
exitcode = EX_OSERR;
1962
/* Lower privileges */
1966
perror_plus("seteuid");
979
exitcode = EXIT_FAILURE;
982
1970
if((network.ifr_flags & IFF_UP) == 0){
983
1971
network.ifr_flags |= IFF_UP;
1972
take_down_interface = true;
984
1973
ret = ioctl(sd, SIOCSIFFLAGS, &network);
986
perror("ioctl SIOCSIFFLAGS");
987
exitcode = EXIT_FAILURE;
1975
take_down_interface = false;
1976
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1977
exitcode = EX_OSERR;
988
1978
#ifdef __linux__
989
ret = klogctl(7, NULL, 0);
1979
if(restore_loglevel){
1980
ret = klogctl(7, NULL, 0);
1982
perror_plus("klogctl");
1985
#endif /* __linux__ */
1986
/* Lower privileges */
1990
perror_plus("seteuid");
997
/* sleep checking until interface is running */
1995
/* Sleep checking until interface is running.
1996
Check every 0.25s, up to total time of delay */
998
1997
for(int i=0; i < delay * 4; i++){
999
1998
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1001
perror("ioctl SIOCGIFFLAGS");
2000
perror_plus("ioctl SIOCGIFFLAGS");
1002
2001
} else if(network.ifr_flags & IFF_RUNNING){
1005
2004
struct timespec sleeptime = { .tv_nsec = 250000000 };
1006
2005
ret = nanosleep(&sleeptime, NULL);
1007
2006
if(ret == -1 and errno != EINTR){
1008
perror("nanosleep");
2007
perror_plus("nanosleep");
1011
ret = (int)TEMP_FAILURE_RETRY(close(sd));
2010
if(not take_down_interface){
2011
/* We won't need the socket anymore */
2012
ret = (int)TEMP_FAILURE_RETRY(close(sd));
2014
perror_plus("close");
1015
2017
#ifdef __linux__
1016
/* Restores kernel loglevel to default */
1017
ret = klogctl(7, NULL, 0);
2018
if(restore_loglevel){
2019
/* Restores kernel loglevel to default */
2020
ret = klogctl(7, NULL, 0);
2022
perror_plus("klogctl");
2025
#endif /* __linux__ */
2026
/* Lower privileges */
2028
/* Lower privileges */
2031
perror_plus("seteuid");
1037
ret = init_gnutls_global(&mc, pubkey, seckey);
1039
fprintf(stderr, "init_gnutls_global failed\n");
1040
exitcode = EXIT_FAILURE;
2039
ret = init_gnutls_global(pubkey, seckey);
2041
fprintf_plus(stderr, "init_gnutls_global failed\n");
2042
exitcode = EX_UNAVAILABLE;
1043
2045
gnutls_initialized = true;
1046
2052
if(mkdtemp(tempdir) == NULL){
2053
perror_plus("mkdtemp");
1050
2056
tempdir_created = true;
1052
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
1053
fprintf(stderr, "init_gpgme failed\n");
1054
exitcode = EXIT_FAILURE;
2062
if(not init_gpgme(pubkey, seckey, tempdir)){
2063
fprintf_plus(stderr, "init_gpgme failed\n");
2064
exitcode = EX_UNAVAILABLE;
1057
2067
gpgme_initialized = true;
1060
if_index = (AvahiIfIndex) if_nametoindex(interface);
1062
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1063
exitcode = EXIT_FAILURE;
1179
2227
gpgme_release(mc.ctx);
1182
/* Removes the temp directory used by GPGME */
2230
/* Cleans up the circular linked list of Mandos servers the client
2232
if(mc.current_server != NULL){
2233
mc.current_server->prev->next = NULL;
2234
while(mc.current_server != NULL){
2235
server *next = mc.current_server->next;
2236
free(mc.current_server);
2237
mc.current_server = next;
2241
/* Run network hooks */
2242
run_network_hooks("stop", interface, delay);
2244
/* Re-raise priviliges */
2249
perror_plus("seteuid");
2252
/* Take down the network interface */
2253
if(take_down_interface and geteuid() == 0){
2254
ret = ioctl(sd, SIOCGIFFLAGS, &network);
2256
perror_plus("ioctl SIOCGIFFLAGS");
2257
} else if(network.ifr_flags & IFF_UP){
2258
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
2259
ret = ioctl(sd, SIOCSIFFLAGS, &network);
2261
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
2264
ret = (int)TEMP_FAILURE_RETRY(close(sd));
2266
perror_plus("close");
2270
/* Lower privileges permanently */
2274
perror_plus("setuid");
2277
/* Removes the GPGME temp directory and all files inside */
1183
2278
if(tempdir_created){
1185
struct dirent *direntry;
1186
d = opendir(tempdir);
1188
if(errno != ENOENT){
1193
direntry = readdir(d);
1194
if(direntry == NULL){
1197
/* Skip "." and ".." */
1198
if(direntry->d_name[0] == '.'
1199
and (direntry->d_name[1] == '\0'
1200
or (direntry->d_name[1] == '.'
1201
and direntry->d_name[2] == '\0'))){
2279
struct dirent **direntries = NULL;
2280
struct dirent *direntry = NULL;
2281
int numentries = scandir(tempdir, &direntries, notdotentries,
2283
if (numentries > 0){
2284
for(int i = 0; i < numentries; i++){
2285
direntry = direntries[i];
1204
2286
char *fullname = NULL;
1205
2287
ret = asprintf(&fullname, "%s/%s", tempdir,
1206
2288
direntry->d_name);
2290
perror_plus("asprintf");
1211
2293
ret = remove(fullname);
1213
fprintf(stderr, "remove(\"%s\"): %s\n", fullname,
2295
fprintf_plus(stderr, "remove(\"%s\"): %s\n", fullname,
1216
2298
free(fullname);
2302
/* need to clean even if 0 because man page doesn't specify */
2304
if (numentries == -1){
2305
perror_plus("scandir");
1220
2307
ret = rmdir(tempdir);
1221
2308
if(ret == -1 and errno != ENOENT){
2309
perror_plus("rmdir");
2314
sigemptyset(&old_sigterm_action.sa_mask);
2315
old_sigterm_action.sa_handler = SIG_DFL;
2316
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
2317
&old_sigterm_action,
2320
perror_plus("sigaction");
2323
ret = raise(signal_received);
2324
} while(ret != 0 and errno == EINTR);
2326
perror_plus("raise");
2329
TEMP_FAILURE_RETRY(pause());
1226
2332
return exitcode;