1
/* -*- coding: utf-8 -*- */
3
* Mandos-client - get and decrypt data from a Mandos server
5
* This program is partly derived from an example program for an Avahi
6
* service browser, downloaded from
7
* <http://avahi.org/browser/examples/core-browse-services.c>. This
8
* includes the following functions: "resolve_callback",
9
* "browse_callback", and parts of "main".
12
* Copyright © 2008-2015 Teddy Hogeborn
13
* Copyright © 2008-2015 Björn Påhlsson
15
* This program is free software: you can redistribute it and/or
16
* modify it under the terms of the GNU General Public License as
17
* published by the Free Software Foundation, either version 3 of the
18
* License, or (at your option) any later version.
20
* This program is distributed in the hope that it will be useful, but
21
* WITHOUT ANY WARRANTY; without even the implied warranty of
22
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
23
* General Public License for more details.
25
* You should have received a copy of the GNU General Public License
26
* along with this program. If not, see
27
* <http://www.gnu.org/licenses/>.
29
* Contact the authors at <mandos@recompile.se>.
32
/* Needed by GPGME, specifically gpgme_data_seek() */
33
#ifndef _LARGEFILE_SOURCE
34
#define _LARGEFILE_SOURCE
35
#endif /* not _LARGEFILE_SOURCE */
36
#ifndef _FILE_OFFSET_BITS
37
#define _FILE_OFFSET_BITS 64
38
#endif /* not _FILE_OFFSET_BITS */
40
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
42
#include <stdio.h> /* fprintf(), stderr, fwrite(),
44
#include <stdint.h> /* uint16_t, uint32_t, intptr_t */
45
#include <stddef.h> /* NULL, size_t, ssize_t */
46
#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),
48
#include <stdbool.h> /* bool, false, true */
49
#include <string.h> /* memset(), strcmp(), strlen(),
50
strerror(), asprintf(), strcpy() */
51
#include <sys/ioctl.h> /* ioctl */
52
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
53
sockaddr_in6, PF_INET6,
54
SOCK_STREAM, uid_t, gid_t, open(),
56
#include <sys/stat.h> /* open(), S_ISREG */
57
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
58
inet_pton(), connect(),
60
#include <fcntl.h> /* open(), unlinkat() */
61
#include <dirent.h> /* opendir(), struct dirent, readdir()
63
#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,
65
#include <errno.h> /* perror(), errno,
66
program_invocation_short_name */
67
#include <time.h> /* nanosleep(), time(), sleep() */
68
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
69
SIOCSIFFLAGS, if_indextoname(),
70
if_nametoindex(), IF_NAMESIZE */
71
#include <netinet/in.h> /* IN6_IS_ADDR_LINKLOCAL,
72
INET_ADDRSTRLEN, INET6_ADDRSTRLEN
74
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
75
getuid(), getgid(), seteuid(),
76
setgid(), pause(), _exit(),
78
#include <arpa/inet.h> /* inet_pton(), htons() */
79
#include <iso646.h> /* not, or, and */
80
#include <argp.h> /* struct argp_option, error_t, struct
81
argp_state, struct argp,
82
argp_parse(), ARGP_KEY_ARG,
83
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
84
#include <signal.h> /* sigemptyset(), sigaddset(),
85
sigaction(), SIGTERM, sig_atomic_t,
87
#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,
88
EX_NOHOST, EX_IOERR, EX_PROTOCOL */
89
#include <sys/wait.h> /* waitpid(), WIFEXITED(),
90
WEXITSTATUS(), WTERMSIG() */
91
#include <grp.h> /* setgroups() */
92
#include <argz.h> /* argz_add_sep(), argz_next(),
93
argz_delete(), argz_append(),
94
argz_stringify(), argz_add(),
96
#include <netdb.h> /* getnameinfo(), NI_NUMERICHOST,
97
EAI_SYSTEM, gai_strerror() */
100
#include <sys/klog.h> /* klogctl() */
101
#endif /* __linux__ */
104
/* All Avahi types, constants and functions
107
#include <avahi-core/core.h>
108
#include <avahi-core/lookup.h>
109
#include <avahi-core/log.h>
110
#include <avahi-common/simple-watch.h>
111
#include <avahi-common/malloc.h>
112
#include <avahi-common/error.h>
115
#include <gnutls/gnutls.h> /* All GnuTLS types, constants and
118
init_gnutls_session(),
120
#include <gnutls/openpgp.h>
121
/* gnutls_certificate_set_openpgp_key_file(),
122
GNUTLS_OPENPGP_FMT_BASE64 */
125
#include <gpgme.h> /* All GPGME types, constants and
128
GPGME_PROTOCOL_OpenPGP,
131
#define BUFFER_SIZE 256
133
#define PATHDIR "/conf/conf.d/mandos"
134
#define SECKEY "seckey.txt"
135
#define PUBKEY "pubkey.txt"
136
#define HOOKDIR "/lib/mandos/network-hooks.d"
139
static const char mandos_protocol_version[] = "1";
140
const char *argp_program_version = "mandos-client " VERSION;
141
const char *argp_program_bug_address = "<mandos@recompile.se>";
142
static const char sys_class_net[] = "/sys/class/net";
143
char *connect_to = NULL;
144
const char *hookdir = HOOKDIR;
149
/* Doubly linked list that need to be circularly linked when used */
150
typedef struct server{
153
AvahiIfIndex if_index;
155
struct timespec last_seen;
160
/* Used for passing in values through the Avahi callback functions */
163
gnutls_certificate_credentials_t cred;
164
unsigned int dh_bits;
165
gnutls_dh_params_t dh_params;
166
const char *priority;
168
server *current_server;
170
size_t interfaces_size;
173
/* global so signal handler can reach it*/
174
AvahiSimplePoll *simple_poll;
176
sig_atomic_t quit_now = 0;
177
int signal_received = 0;
179
/* Function to use when printing errors */
180
void perror_plus(const char *print_text){
182
fprintf(stderr, "Mandos plugin %s: ",
183
program_invocation_short_name);
188
__attribute__((format (gnu_printf, 2, 3), nonnull))
189
int fprintf_plus(FILE *stream, const char *format, ...){
191
va_start (ap, format);
193
TEMP_FAILURE_RETRY(fprintf(stream, "Mandos plugin %s: ",
194
program_invocation_short_name));
195
return (int)TEMP_FAILURE_RETRY(vfprintf(stream, format, ap));
199
* Make additional room in "buffer" for at least BUFFER_SIZE more
200
* bytes. "buffer_capacity" is how much is currently allocated,
201
* "buffer_length" is how much is already used.
203
__attribute__((nonnull, warn_unused_result))
204
size_t incbuffer(char **buffer, size_t buffer_length,
205
size_t buffer_capacity){
206
if(buffer_length + BUFFER_SIZE > buffer_capacity){
207
char *new_buf = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
209
int old_errno = errno;
216
buffer_capacity += BUFFER_SIZE;
218
return buffer_capacity;
221
/* Add server to set of servers to retry periodically */
222
__attribute__((nonnull, warn_unused_result))
223
bool add_server(const char *ip, in_port_t port, AvahiIfIndex if_index,
224
int af, server **current_server){
226
server *new_server = malloc(sizeof(server));
227
if(new_server == NULL){
228
perror_plus("malloc");
231
*new_server = (server){ .ip = strdup(ip),
233
.if_index = if_index,
235
if(new_server->ip == NULL){
236
perror_plus("strdup");
240
ret = clock_gettime(CLOCK_MONOTONIC, &(new_server->last_seen));
242
perror_plus("clock_gettime");
244
#pragma GCC diagnostic push
245
#pragma GCC diagnostic ignored "-Wcast-qual"
247
free((char *)(new_server->ip));
249
#pragma GCC diagnostic pop
254
/* Special case of first server */
255
if(*current_server == NULL){
256
new_server->next = new_server;
257
new_server->prev = new_server;
258
*current_server = new_server;
260
/* Place the new server last in the list */
261
new_server->next = *current_server;
262
new_server->prev = (*current_server)->prev;
263
new_server->prev->next = new_server;
264
(*current_server)->prev = new_server;
272
__attribute__((nonnull, warn_unused_result))
273
static bool init_gpgme(const char * const seckey,
274
const char * const pubkey,
275
const char * const tempdir,
278
gpgme_engine_info_t engine_info;
281
* Helper function to insert pub and seckey to the engine keyring.
283
bool import_key(const char * const filename){
286
gpgme_data_t pgp_data;
288
fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
294
rc = gpgme_data_new_from_fd(&pgp_data, fd);
295
if(rc != GPG_ERR_NO_ERROR){
296
fprintf_plus(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
297
gpgme_strsource(rc), gpgme_strerror(rc));
301
rc = gpgme_op_import(mc->ctx, pgp_data);
302
if(rc != GPG_ERR_NO_ERROR){
303
fprintf_plus(stderr, "bad gpgme_op_import: %s: %s\n",
304
gpgme_strsource(rc), gpgme_strerror(rc));
308
ret = (int)TEMP_FAILURE_RETRY(close(fd));
310
perror_plus("close");
312
gpgme_data_release(pgp_data);
317
fprintf_plus(stderr, "Initializing GPGME\n");
321
gpgme_check_version(NULL);
322
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
323
if(rc != GPG_ERR_NO_ERROR){
324
fprintf_plus(stderr, "bad gpgme_engine_check_version: %s: %s\n",
325
gpgme_strsource(rc), gpgme_strerror(rc));
329
/* Set GPGME home directory for the OpenPGP engine only */
330
rc = gpgme_get_engine_info(&engine_info);
331
if(rc != GPG_ERR_NO_ERROR){
332
fprintf_plus(stderr, "bad gpgme_get_engine_info: %s: %s\n",
333
gpgme_strsource(rc), gpgme_strerror(rc));
336
while(engine_info != NULL){
337
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
338
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
339
engine_info->file_name, tempdir);
342
engine_info = engine_info->next;
344
if(engine_info == NULL){
345
fprintf_plus(stderr, "Could not set GPGME home dir to %s\n",
350
/* Create new GPGME "context" */
351
rc = gpgme_new(&(mc->ctx));
352
if(rc != GPG_ERR_NO_ERROR){
353
fprintf_plus(stderr, "Mandos plugin mandos-client: "
354
"bad gpgme_new: %s: %s\n", gpgme_strsource(rc),
359
if(not import_key(pubkey) or not import_key(seckey)){
367
* Decrypt OpenPGP data.
368
* Returns -1 on error
370
__attribute__((nonnull, warn_unused_result))
371
static ssize_t pgp_packet_decrypt(const char *cryptotext,
375
gpgme_data_t dh_crypto, dh_plain;
378
size_t plaintext_capacity = 0;
379
ssize_t plaintext_length = 0;
382
fprintf_plus(stderr, "Trying to decrypt OpenPGP data\n");
385
/* Create new GPGME data buffer from memory cryptotext */
386
rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,
388
if(rc != GPG_ERR_NO_ERROR){
389
fprintf_plus(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
390
gpgme_strsource(rc), gpgme_strerror(rc));
394
/* Create new empty GPGME data buffer for the plaintext */
395
rc = gpgme_data_new(&dh_plain);
396
if(rc != GPG_ERR_NO_ERROR){
397
fprintf_plus(stderr, "Mandos plugin mandos-client: "
398
"bad gpgme_data_new: %s: %s\n",
399
gpgme_strsource(rc), gpgme_strerror(rc));
400
gpgme_data_release(dh_crypto);
404
/* Decrypt data from the cryptotext data buffer to the plaintext
406
rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);
407
if(rc != GPG_ERR_NO_ERROR){
408
fprintf_plus(stderr, "bad gpgme_op_decrypt: %s: %s\n",
409
gpgme_strsource(rc), gpgme_strerror(rc));
410
plaintext_length = -1;
412
gpgme_decrypt_result_t result;
413
result = gpgme_op_decrypt_result(mc->ctx);
415
fprintf_plus(stderr, "gpgme_op_decrypt_result failed\n");
417
fprintf_plus(stderr, "Unsupported algorithm: %s\n",
418
result->unsupported_algorithm);
419
fprintf_plus(stderr, "Wrong key usage: %u\n",
420
result->wrong_key_usage);
421
if(result->file_name != NULL){
422
fprintf_plus(stderr, "File name: %s\n", result->file_name);
424
gpgme_recipient_t recipient;
425
recipient = result->recipients;
426
while(recipient != NULL){
427
fprintf_plus(stderr, "Public key algorithm: %s\n",
428
gpgme_pubkey_algo_name
429
(recipient->pubkey_algo));
430
fprintf_plus(stderr, "Key ID: %s\n", recipient->keyid);
431
fprintf_plus(stderr, "Secret key available: %s\n",
432
recipient->status == GPG_ERR_NO_SECKEY
434
recipient = recipient->next;
442
fprintf_plus(stderr, "Decryption of OpenPGP data succeeded\n");
445
/* Seek back to the beginning of the GPGME plaintext data buffer */
446
if(gpgme_data_seek(dh_plain, (off_t)0, SEEK_SET) == -1){
447
perror_plus("gpgme_data_seek");
448
plaintext_length = -1;
454
plaintext_capacity = incbuffer(plaintext,
455
(size_t)plaintext_length,
457
if(plaintext_capacity == 0){
458
perror_plus("incbuffer");
459
plaintext_length = -1;
463
ret = gpgme_data_read(dh_plain, *plaintext + plaintext_length,
465
/* Print the data, if any */
471
perror_plus("gpgme_data_read");
472
plaintext_length = -1;
475
plaintext_length += ret;
479
fprintf_plus(stderr, "Decrypted password is: ");
480
for(ssize_t i = 0; i < plaintext_length; i++){
481
fprintf(stderr, "%02hhX ", (*plaintext)[i]);
483
fprintf(stderr, "\n");
488
/* Delete the GPGME cryptotext data buffer */
489
gpgme_data_release(dh_crypto);
491
/* Delete the GPGME plaintext data buffer */
492
gpgme_data_release(dh_plain);
493
return plaintext_length;
496
__attribute__((warn_unused_result))
497
static const char *safer_gnutls_strerror(int value){
498
const char *ret = gnutls_strerror(value);
504
/* GnuTLS log function callback */
505
__attribute__((nonnull))
506
static void debuggnutls(__attribute__((unused)) int level,
508
fprintf_plus(stderr, "GnuTLS: %s", string);
511
__attribute__((nonnull, warn_unused_result))
512
static int init_gnutls_global(const char *pubkeyfilename,
513
const char *seckeyfilename,
518
fprintf_plus(stderr, "Initializing GnuTLS\n");
521
ret = gnutls_global_init();
522
if(ret != GNUTLS_E_SUCCESS){
523
fprintf_plus(stderr, "GnuTLS global_init: %s\n",
524
safer_gnutls_strerror(ret));
529
/* "Use a log level over 10 to enable all debugging options."
532
gnutls_global_set_log_level(11);
533
gnutls_global_set_log_function(debuggnutls);
536
/* OpenPGP credentials */
537
ret = gnutls_certificate_allocate_credentials(&mc->cred);
538
if(ret != GNUTLS_E_SUCCESS){
539
fprintf_plus(stderr, "GnuTLS memory error: %s\n",
540
safer_gnutls_strerror(ret));
541
gnutls_global_deinit();
546
fprintf_plus(stderr, "Attempting to use OpenPGP public key %s and"
547
" secret key %s as GnuTLS credentials\n",
552
ret = gnutls_certificate_set_openpgp_key_file
553
(mc->cred, pubkeyfilename, seckeyfilename,
554
GNUTLS_OPENPGP_FMT_BASE64);
555
if(ret != GNUTLS_E_SUCCESS){
557
"Error[%d] while reading the OpenPGP key pair ('%s',"
558
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
559
fprintf_plus(stderr, "The GnuTLS error is: %s\n",
560
safer_gnutls_strerror(ret));
564
/* GnuTLS server initialization */
565
ret = gnutls_dh_params_init(&mc->dh_params);
566
if(ret != GNUTLS_E_SUCCESS){
567
fprintf_plus(stderr, "Error in GnuTLS DH parameter"
568
" initialization: %s\n",
569
safer_gnutls_strerror(ret));
572
ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);
573
if(ret != GNUTLS_E_SUCCESS){
574
fprintf_plus(stderr, "Error in GnuTLS prime generation: %s\n",
575
safer_gnutls_strerror(ret));
579
gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);
585
gnutls_certificate_free_credentials(mc->cred);
586
gnutls_global_deinit();
587
gnutls_dh_params_deinit(mc->dh_params);
591
__attribute__((nonnull, warn_unused_result))
592
static int init_gnutls_session(gnutls_session_t *session,
595
/* GnuTLS session creation */
597
ret = gnutls_init(session, GNUTLS_SERVER);
601
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
602
if(ret != GNUTLS_E_SUCCESS){
604
"Error in GnuTLS session initialization: %s\n",
605
safer_gnutls_strerror(ret));
611
ret = gnutls_priority_set_direct(*session, mc->priority, &err);
613
gnutls_deinit(*session);
616
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
617
if(ret != GNUTLS_E_SUCCESS){
618
fprintf_plus(stderr, "Syntax error at: %s\n", err);
619
fprintf_plus(stderr, "GnuTLS error: %s\n",
620
safer_gnutls_strerror(ret));
621
gnutls_deinit(*session);
627
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
630
gnutls_deinit(*session);
633
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
634
if(ret != GNUTLS_E_SUCCESS){
635
fprintf_plus(stderr, "Error setting GnuTLS credentials: %s\n",
636
safer_gnutls_strerror(ret));
637
gnutls_deinit(*session);
641
/* ignore client certificate if any. */
642
gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);
644
gnutls_dh_set_prime_bits(*session, mc->dh_bits);
649
/* Avahi log function callback */
650
static void empty_log(__attribute__((unused)) AvahiLogLevel level,
651
__attribute__((unused)) const char *txt){}
653
/* Set effective uid to 0, return errno */
654
__attribute__((warn_unused_result))
655
error_t raise_privileges(void){
656
error_t old_errno = errno;
657
error_t ret_errno = 0;
658
if(seteuid(0) == -1){
665
/* Set effective and real user ID to 0. Return errno. */
666
__attribute__((warn_unused_result))
667
error_t raise_privileges_permanently(void){
668
error_t old_errno = errno;
669
error_t ret_errno = raise_privileges();
681
/* Set effective user ID to unprivileged saved user ID */
682
__attribute__((warn_unused_result))
683
error_t lower_privileges(void){
684
error_t old_errno = errno;
685
error_t ret_errno = 0;
686
if(seteuid(uid) == -1){
693
/* Lower privileges permanently */
694
__attribute__((warn_unused_result))
695
error_t lower_privileges_permanently(void){
696
error_t old_errno = errno;
697
error_t ret_errno = 0;
698
if(setuid(uid) == -1){
705
/* Helper function to add_local_route() and remove_local_route() */
706
__attribute__((nonnull, warn_unused_result))
707
static bool add_remove_local_route(const bool add,
709
AvahiIfIndex if_index){
711
char helper[] = "mandos-client-iprouteadddel";
712
char add_arg[] = "add";
713
char remove_arg[] = "remove";
714
char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");
715
if(pluginhelperdir == NULL){
717
fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"
718
" variable not set; cannot run helper\n");
723
char interface[IF_NAMESIZE];
724
if(if_indextoname((unsigned int)if_index, interface) == NULL){
725
perror_plus("if_indextoname");
729
int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));
731
perror_plus("open(\"/dev/null\", O_RDONLY)");
737
/* Raise privileges */
738
errno = raise_privileges_permanently();
740
perror_plus("Failed to raise privileges");
741
/* _exit(EX_NOPERM); */
747
perror_plus("setgid");
750
/* Reset supplementary groups */
752
ret = setgroups(0, NULL);
754
perror_plus("setgroups");
758
ret = dup2(devnull, STDIN_FILENO);
760
perror_plus("dup2(devnull, STDIN_FILENO)");
763
ret = close(devnull);
765
perror_plus("close");
768
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
770
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
773
int helperdir_fd = (int)TEMP_FAILURE_RETRY(open(pluginhelperdir,
778
int helper_fd = (int)TEMP_FAILURE_RETRY(openat(helperdir_fd,
780
TEMP_FAILURE_RETRY(close(helperdir_fd));
782
#pragma GCC diagnostic push
783
#pragma GCC diagnostic ignored "-Wcast-qual"
785
if(fexecve(helper_fd, (char *const [])
786
{ helper, add ? add_arg : remove_arg, (char *)address,
787
interface, NULL }, environ) == -1){
789
#pragma GCC diagnostic pop
791
perror_plus("fexecve");
803
pret = waitpid(pid, &status, 0);
804
if(pret == -1 and errno == EINTR and quit_now){
805
int errno_raising = 0;
806
if((errno = raise_privileges()) != 0){
807
errno_raising = errno;
808
perror_plus("Failed to raise privileges in order to"
809
" kill helper program");
811
if(kill(pid, SIGTERM) == -1){
814
if((errno_raising == 0) and (errno = lower_privileges()) != 0){
815
perror_plus("Failed to lower privileges after killing"
820
} while(pret == -1 and errno == EINTR);
822
perror_plus("waitpid");
825
if(WIFEXITED(status)){
826
if(WEXITSTATUS(status) != 0){
827
fprintf_plus(stderr, "Error: iprouteadddel exited"
828
" with status %d\n", WEXITSTATUS(status));
833
if(WIFSIGNALED(status)){
834
fprintf_plus(stderr, "Error: iprouteadddel died by"
835
" signal %d\n", WTERMSIG(status));
838
fprintf_plus(stderr, "Error: iprouteadddel crashed\n");
842
__attribute__((nonnull, warn_unused_result))
843
static bool add_local_route(const char *address,
844
AvahiIfIndex if_index){
845
return add_remove_local_route(true, address, if_index);
848
__attribute__((nonnull, warn_unused_result))
849
static bool remove_local_route(const char *address,
850
AvahiIfIndex if_index){
851
return add_remove_local_route(false, address, if_index);
854
/* Called when a Mandos server is found */
855
__attribute__((nonnull, warn_unused_result))
856
static int start_mandos_communication(const char *ip, in_port_t port,
857
AvahiIfIndex if_index,
858
int af, mandos_context *mc){
859
int ret, tcp_sd = -1;
861
struct sockaddr_storage to;
863
char *decrypted_buffer = NULL;
864
size_t buffer_length = 0;
865
size_t buffer_capacity = 0;
868
gnutls_session_t session;
869
int pf; /* Protocol family */
870
bool route_added = false;
887
fprintf_plus(stderr, "Bad address family: %d\n", af);
892
/* If the interface is specified and we have a list of interfaces */
893
if(if_index != AVAHI_IF_UNSPEC and mc->interfaces != NULL){
894
/* Check if the interface is one of the interfaces we are using */
897
char *interface = NULL;
898
while((interface=argz_next(mc->interfaces, mc->interfaces_size,
900
if(if_nametoindex(interface) == (unsigned int)if_index){
907
/* This interface does not match any in the list, so we don't
908
connect to the server */
910
char interface[IF_NAMESIZE];
911
if(if_indextoname((unsigned int)if_index, interface) == NULL){
912
perror_plus("if_indextoname");
914
fprintf_plus(stderr, "Skipping server on non-used interface"
916
if_indextoname((unsigned int)if_index,
924
ret = init_gnutls_session(&session, mc);
930
fprintf_plus(stderr, "Setting up a TCP connection to %s, port %"
931
PRIuMAX "\n", ip, (uintmax_t)port);
934
tcp_sd = socket(pf, SOCK_STREAM | SOCK_CLOEXEC, 0);
937
perror_plus("socket");
947
memset(&to, 0, sizeof(to));
949
((struct sockaddr_in6 *)&to)->sin6_family = (sa_family_t)af;
950
ret = inet_pton(af, ip, &((struct sockaddr_in6 *)&to)->sin6_addr);
952
((struct sockaddr_in *)&to)->sin_family = (sa_family_t)af;
953
ret = inet_pton(af, ip, &((struct sockaddr_in *)&to)->sin_addr);
957
perror_plus("inet_pton");
963
fprintf_plus(stderr, "Bad address: %s\n", ip);
968
((struct sockaddr_in6 *)&to)->sin6_port = htons(port);
969
if(IN6_IS_ADDR_LINKLOCAL
970
(&((struct sockaddr_in6 *)&to)->sin6_addr)){
971
if(if_index == AVAHI_IF_UNSPEC){
972
fprintf_plus(stderr, "An IPv6 link-local address is"
973
" incomplete without a network interface\n");
977
/* Set the network interface number as scope */
978
((struct sockaddr_in6 *)&to)->sin6_scope_id = (uint32_t)if_index;
981
((struct sockaddr_in *)&to)->sin_port = htons(port);
990
if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){
991
char interface[IF_NAMESIZE];
992
if(if_indextoname((unsigned int)if_index, interface) == NULL){
993
perror_plus("if_indextoname");
995
fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIuMAX
996
"\n", ip, interface, (uintmax_t)port);
999
fprintf_plus(stderr, "Connection to: %s, port %" PRIuMAX "\n",
1000
ip, (uintmax_t)port);
1002
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
1003
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
1005
ret = getnameinfo((struct sockaddr *)&to,
1006
sizeof(struct sockaddr_in6),
1007
addrstr, sizeof(addrstr), NULL, 0,
1010
ret = getnameinfo((struct sockaddr *)&to,
1011
sizeof(struct sockaddr_in),
1012
addrstr, sizeof(addrstr), NULL, 0,
1015
if(ret == EAI_SYSTEM){
1016
perror_plus("getnameinfo");
1017
} else if(ret != 0) {
1018
fprintf_plus(stderr, "getnameinfo: %s", gai_strerror(ret));
1019
} else if(strcmp(addrstr, ip) != 0){
1020
fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);
1031
ret = connect(tcp_sd, (struct sockaddr *)&to,
1032
sizeof(struct sockaddr_in6));
1034
ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */
1035
sizeof(struct sockaddr_in));
1038
if(errno == ENETUNREACH
1039
and if_index != AVAHI_IF_UNSPEC
1040
and connect_to == NULL
1041
and not route_added and
1042
((af == AF_INET6 and not
1043
IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)
1045
or (af == AF_INET and
1046
/* Not a a IPv4LL address */
1047
(ntohl(((struct sockaddr_in *)&to)->sin_addr.s_addr)
1048
& 0xFFFF0000L) != 0xA9FE0000L))){
1049
/* Work around Avahi bug - Avahi does not announce link-local
1050
addresses if it has a global address, so local hosts with
1051
*only* a link-local address (e.g. Mandos clients) cannot
1052
connect to a Mandos server announced by Avahi on a server
1053
host with a global address. Work around this by retrying
1054
with an explicit route added with the server's address.
1056
Avahi bug reference:
1057
http://lists.freedesktop.org/archives/avahi/2010-February/001833.html
1058
https://bugs.debian.org/587961
1061
route_added = add_local_route(ip, if_index);
1067
if(errno != ECONNREFUSED or debug){
1069
perror_plus("connect");
1082
const char *out = mandos_protocol_version;
1085
size_t out_size = strlen(out);
1086
ret = (int)TEMP_FAILURE_RETRY(write(tcp_sd, out + written,
1087
out_size - written));
1090
perror_plus("write");
1094
written += (size_t)ret;
1095
if(written < out_size){
1098
if(out == mandos_protocol_version){
1113
fprintf_plus(stderr, "Establishing TLS session with %s\n", ip);
1121
/* This casting via intptr_t is to eliminate warning about casting
1122
an int to a pointer type. This is exactly how the GnuTLS Guile
1123
function "set-session-transport-fd!" does it. */
1124
gnutls_transport_set_ptr(session,
1125
(gnutls_transport_ptr_t)(intptr_t)tcp_sd);
1133
ret = gnutls_handshake(session);
1138
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
1140
if(ret != GNUTLS_E_SUCCESS){
1142
fprintf_plus(stderr, "*** GnuTLS Handshake failed ***\n");
1149
/* Read OpenPGP packet that contains the wanted password */
1152
fprintf_plus(stderr, "Retrieving OpenPGP encrypted password from"
1163
buffer_capacity = incbuffer(&buffer, buffer_length,
1165
if(buffer_capacity == 0){
1167
perror_plus("incbuffer");
1177
sret = gnutls_record_recv(session, buffer+buffer_length,
1184
case GNUTLS_E_INTERRUPTED:
1185
case GNUTLS_E_AGAIN:
1187
case GNUTLS_E_REHANDSHAKE:
1189
ret = gnutls_handshake(session);
1195
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
1197
fprintf_plus(stderr, "*** GnuTLS Re-handshake failed "
1205
fprintf_plus(stderr, "Unknown error while reading data from"
1206
" encrypted session with Mandos server\n");
1207
gnutls_bye(session, GNUTLS_SHUT_RDWR);
1212
buffer_length += (size_t) sret;
1217
fprintf_plus(stderr, "Closing TLS session\n");
1226
ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);
1231
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
1233
if(buffer_length > 0){
1234
ssize_t decrypted_buffer_size;
1235
decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,
1236
&decrypted_buffer, mc);
1237
if(decrypted_buffer_size >= 0){
1240
while(written < (size_t) decrypted_buffer_size){
1246
ret = (int)fwrite(decrypted_buffer + written, 1,
1247
(size_t)decrypted_buffer_size - written,
1249
if(ret == 0 and ferror(stdout)){
1252
fprintf_plus(stderr, "Error writing encrypted data: %s\n",
1258
written += (size_t)ret;
1264
/* Shutdown procedure */
1269
if(not remove_local_route(ip, if_index)){
1270
fprintf_plus(stderr, "Failed to remove local route to %s on"
1271
" interface %d", ip, if_index);
1275
free(decrypted_buffer);
1278
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
1284
perror_plus("close");
1286
gnutls_deinit(session);
1296
__attribute__((nonnull))
1297
static void resolve_callback(AvahiSServiceResolver *r,
1298
AvahiIfIndex interface,
1299
AvahiProtocol proto,
1300
AvahiResolverEvent event,
1304
const char *host_name,
1305
const AvahiAddress *address,
1307
AVAHI_GCC_UNUSED AvahiStringList *txt,
1308
AVAHI_GCC_UNUSED AvahiLookupResultFlags
1315
/* Called whenever a service has been resolved successfully or
1319
avahi_s_service_resolver_free(r);
1325
case AVAHI_RESOLVER_FAILURE:
1326
fprintf_plus(stderr, "(Avahi Resolver) Failed to resolve service "
1327
"'%s' of type '%s' in domain '%s': %s\n", name, type,
1329
avahi_strerror(avahi_server_errno
1330
(((mandos_context*)mc)->server)));
1333
case AVAHI_RESOLVER_FOUND:
1335
char ip[AVAHI_ADDRESS_STR_MAX];
1336
avahi_address_snprint(ip, sizeof(ip), address);
1338
fprintf_plus(stderr, "Mandos server \"%s\" found on %s (%s, %"
1339
PRIdMAX ") on port %" PRIu16 "\n", name,
1340
host_name, ip, (intmax_t)interface, port);
1342
int ret = start_mandos_communication(ip, (in_port_t)port,
1344
avahi_proto_to_af(proto),
1347
avahi_simple_poll_quit(simple_poll);
1349
if(not add_server(ip, (in_port_t)port, interface,
1350
avahi_proto_to_af(proto),
1351
&((mandos_context*)mc)->current_server)){
1352
fprintf_plus(stderr, "Failed to add server \"%s\" to server"
1358
avahi_s_service_resolver_free(r);
1361
static void browse_callback(AvahiSServiceBrowser *b,
1362
AvahiIfIndex interface,
1363
AvahiProtocol protocol,
1364
AvahiBrowserEvent event,
1368
AVAHI_GCC_UNUSED AvahiLookupResultFlags
1375
/* Called whenever a new services becomes available on the LAN or
1376
is removed from the LAN */
1384
case AVAHI_BROWSER_FAILURE:
1386
fprintf_plus(stderr, "(Avahi browser) %s\n",
1387
avahi_strerror(avahi_server_errno
1388
(((mandos_context*)mc)->server)));
1389
avahi_simple_poll_quit(simple_poll);
1392
case AVAHI_BROWSER_NEW:
1393
/* We ignore the returned Avahi resolver object. In the callback
1394
function we free it. If the Avahi server is terminated before
1395
the callback function is called the Avahi server will free the
1398
if(avahi_s_service_resolver_new(((mandos_context*)mc)->server,
1399
interface, protocol, name, type,
1400
domain, protocol, 0,
1401
resolve_callback, mc) == NULL)
1402
fprintf_plus(stderr, "Avahi: Failed to resolve service '%s':"
1404
avahi_strerror(avahi_server_errno
1405
(((mandos_context*)mc)->server)));
1408
case AVAHI_BROWSER_REMOVE:
1411
case AVAHI_BROWSER_ALL_FOR_NOW:
1412
case AVAHI_BROWSER_CACHE_EXHAUSTED:
1414
fprintf_plus(stderr, "No Mandos server found, still"
1421
/* Signal handler that stops main loop after SIGTERM */
1422
static void handle_sigterm(int sig){
1427
signal_received = sig;
1428
int old_errno = errno;
1429
/* set main loop to exit */
1430
if(simple_poll != NULL){
1431
avahi_simple_poll_quit(simple_poll);
1436
__attribute__((nonnull, warn_unused_result))
1437
bool get_flags(const char *ifname, struct ifreq *ifr){
1441
int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1444
perror_plus("socket");
1448
strcpy(ifr->ifr_name, ifname);
1449
ret = ioctl(s, SIOCGIFFLAGS, ifr);
1453
perror_plus("ioctl SIOCGIFFLAGS");
1461
__attribute__((nonnull, warn_unused_result))
1462
bool good_flags(const char *ifname, const struct ifreq *ifr){
1464
/* Reject the loopback device */
1465
if(ifr->ifr_flags & IFF_LOOPBACK){
1467
fprintf_plus(stderr, "Rejecting loopback interface \"%s\"\n",
1472
/* Accept point-to-point devices only if connect_to is specified */
1473
if(connect_to != NULL and (ifr->ifr_flags & IFF_POINTOPOINT)){
1475
fprintf_plus(stderr, "Accepting point-to-point interface"
1476
" \"%s\"\n", ifname);
1480
/* Otherwise, reject non-broadcast-capable devices */
1481
if(not (ifr->ifr_flags & IFF_BROADCAST)){
1483
fprintf_plus(stderr, "Rejecting non-broadcast interface"
1484
" \"%s\"\n", ifname);
1488
/* Reject non-ARP interfaces (including dummy interfaces) */
1489
if(ifr->ifr_flags & IFF_NOARP){
1491
fprintf_plus(stderr, "Rejecting non-ARP interface \"%s\"\n",
1497
/* Accept this device */
1499
fprintf_plus(stderr, "Interface \"%s\" is good\n", ifname);
1505
* This function determines if a directory entry in /sys/class/net
1506
* corresponds to an acceptable network device.
1507
* (This function is passed to scandir(3) as a filter function.)
1509
__attribute__((nonnull, warn_unused_result))
1510
int good_interface(const struct dirent *if_entry){
1511
if(if_entry->d_name[0] == '.'){
1516
if(not get_flags(if_entry->d_name, &ifr)){
1518
fprintf_plus(stderr, "Failed to get flags for interface "
1519
"\"%s\"\n", if_entry->d_name);
1524
if(not good_flags(if_entry->d_name, &ifr)){
1531
* This function determines if a network interface is up.
1533
__attribute__((nonnull, warn_unused_result))
1534
bool interface_is_up(const char *interface){
1536
if(not get_flags(interface, &ifr)){
1538
fprintf_plus(stderr, "Failed to get flags for interface "
1539
"\"%s\"\n", interface);
1544
return (bool)(ifr.ifr_flags & IFF_UP);
1548
* This function determines if a network interface is running
1550
__attribute__((nonnull, warn_unused_result))
1551
bool interface_is_running(const char *interface){
1553
if(not get_flags(interface, &ifr)){
1555
fprintf_plus(stderr, "Failed to get flags for interface "
1556
"\"%s\"\n", interface);
1561
return (bool)(ifr.ifr_flags & IFF_RUNNING);
1564
__attribute__((nonnull, pure, warn_unused_result))
1565
int notdotentries(const struct dirent *direntry){
1566
/* Skip "." and ".." */
1567
if(direntry->d_name[0] == '.'
1568
and (direntry->d_name[1] == '\0'
1569
or (direntry->d_name[1] == '.'
1570
and direntry->d_name[2] == '\0'))){
1576
/* Is this directory entry a runnable program? */
1577
__attribute__((nonnull, warn_unused_result))
1578
int runnable_hook(const struct dirent *direntry){
1583
if((direntry->d_name)[0] == '\0'){
1588
sret = strspn(direntry->d_name, "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
1589
"abcdefghijklmnopqrstuvwxyz"
1592
if((direntry->d_name)[sret] != '\0'){
1593
/* Contains non-allowed characters */
1595
fprintf_plus(stderr, "Ignoring hook \"%s\" with bad name\n",
1601
ret = fstatat(hookdir_fd, direntry->d_name, &st, 0);
1604
perror_plus("Could not stat hook");
1608
if(not (S_ISREG(st.st_mode))){
1609
/* Not a regular file */
1611
fprintf_plus(stderr, "Ignoring hook \"%s\" - not a file\n",
1616
if(not (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))){
1617
/* Not executable */
1619
fprintf_plus(stderr, "Ignoring hook \"%s\" - not executable\n",
1625
fprintf_plus(stderr, "Hook \"%s\" is acceptable\n",
1631
__attribute__((nonnull, warn_unused_result))
1632
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,
1633
mandos_context *mc){
1635
struct timespec now;
1636
struct timespec waited_time;
1637
intmax_t block_time;
1640
if(mc->current_server == NULL){
1642
fprintf_plus(stderr, "Wait until first server is found."
1645
ret = avahi_simple_poll_iterate(s, -1);
1648
fprintf_plus(stderr, "Check current_server if we should run"
1651
/* the current time */
1652
ret = clock_gettime(CLOCK_MONOTONIC, &now);
1654
perror_plus("clock_gettime");
1657
/* Calculating in ms how long time between now and server
1658
who we visted longest time ago. Now - last seen. */
1659
waited_time.tv_sec = (now.tv_sec
1660
- mc->current_server->last_seen.tv_sec);
1661
waited_time.tv_nsec = (now.tv_nsec
1662
- mc->current_server->last_seen.tv_nsec);
1663
/* total time is 10s/10,000ms.
1664
Converting to s from ms by dividing by 1,000,
1665
and ns to ms by dividing by 1,000,000. */
1666
block_time = ((retry_interval
1667
- ((intmax_t)waited_time.tv_sec * 1000))
1668
- ((intmax_t)waited_time.tv_nsec / 1000000));
1671
fprintf_plus(stderr, "Blocking for %" PRIdMAX " ms\n",
1675
if(block_time <= 0){
1676
ret = start_mandos_communication(mc->current_server->ip,
1677
mc->current_server->port,
1678
mc->current_server->if_index,
1679
mc->current_server->af, mc);
1681
avahi_simple_poll_quit(s);
1684
ret = clock_gettime(CLOCK_MONOTONIC,
1685
&mc->current_server->last_seen);
1687
perror_plus("clock_gettime");
1690
mc->current_server = mc->current_server->next;
1691
block_time = 0; /* Call avahi to find new Mandos
1692
servers, but don't block */
1695
ret = avahi_simple_poll_iterate(s, (int)block_time);
1698
if(ret > 0 or errno != EINTR){
1699
return (ret != 1) ? ret : 0;
1705
__attribute__((nonnull))
1706
void run_network_hooks(const char *mode, const char *interface,
1708
struct dirent **direntries = NULL;
1709
if(hookdir_fd == -1){
1710
hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH
1712
if(hookdir_fd == -1){
1713
if(errno == ENOENT){
1715
fprintf_plus(stderr, "Network hook directory \"%s\" not"
1716
" found\n", hookdir);
1719
perror_plus("open");
1725
#if __GLIBC_PREREQ(2, 15)
1726
int numhooks = scandirat(hookdir_fd, ".", &direntries,
1727
runnable_hook, alphasort);
1728
#else /* not __GLIBC_PREREQ(2, 15) */
1729
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1731
#endif /* not __GLIBC_PREREQ(2, 15) */
1732
#else /* not __GLIBC__ */
1733
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1735
#endif /* not __GLIBC__ */
1737
perror_plus("scandir");
1740
struct dirent *direntry;
1742
int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));
1744
perror_plus("open(\"/dev/null\", O_RDONLY)");
1747
for(int i = 0; i < numhooks; i++){
1748
direntry = direntries[i];
1750
fprintf_plus(stderr, "Running network hook \"%s\"\n",
1753
pid_t hook_pid = fork();
1756
/* Raise privileges */
1757
errno = raise_privileges_permanently();
1759
perror_plus("Failed to raise privileges");
1766
perror_plus("setgid");
1769
/* Reset supplementary groups */
1771
ret = setgroups(0, NULL);
1773
perror_plus("setgroups");
1776
ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);
1778
perror_plus("setenv");
1781
ret = setenv("DEVICE", interface, 1);
1783
perror_plus("setenv");
1786
ret = setenv("VERBOSITY", debug ? "1" : "0", 1);
1788
perror_plus("setenv");
1791
ret = setenv("MODE", mode, 1);
1793
perror_plus("setenv");
1797
ret = asprintf(&delaystring, "%f", (double)delay);
1799
perror_plus("asprintf");
1802
ret = setenv("DELAY", delaystring, 1);
1805
perror_plus("setenv");
1809
if(connect_to != NULL){
1810
ret = setenv("CONNECT", connect_to, 1);
1812
perror_plus("setenv");
1816
int hook_fd = TEMP_FAILURE_RETRY(openat(hookdir_fd,
1820
perror_plus("openat");
1821
_exit(EXIT_FAILURE);
1823
if((int)TEMP_FAILURE_RETRY(close(hookdir_fd)) == -1){
1824
perror_plus("close");
1825
_exit(EXIT_FAILURE);
1827
ret = dup2(devnull, STDIN_FILENO);
1829
perror_plus("dup2(devnull, STDIN_FILENO)");
1832
ret = close(devnull);
1834
perror_plus("close");
1837
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
1839
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
1842
if(fexecve(hook_fd, (char *const []){ direntry->d_name, NULL },
1844
perror_plus("fexecve");
1845
_exit(EXIT_FAILURE);
1849
perror_plus("fork");
1854
if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){
1855
perror_plus("waitpid");
1859
if(WIFEXITED(status)){
1860
if(WEXITSTATUS(status) != 0){
1861
fprintf_plus(stderr, "Warning: network hook \"%s\" exited"
1862
" with status %d\n", direntry->d_name,
1863
WEXITSTATUS(status));
1867
} else if(WIFSIGNALED(status)){
1868
fprintf_plus(stderr, "Warning: network hook \"%s\" died by"
1869
" signal %d\n", direntry->d_name,
1874
fprintf_plus(stderr, "Warning: network hook \"%s\""
1875
" crashed\n", direntry->d_name);
1881
fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",
1887
if((int)TEMP_FAILURE_RETRY(close(hookdir_fd)) == -1){
1888
perror_plus("close");
1895
__attribute__((nonnull, warn_unused_result))
1896
error_t bring_up_interface(const char *const interface,
1898
error_t old_errno = errno;
1900
struct ifreq network;
1901
unsigned int if_index = if_nametoindex(interface);
1903
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1913
if(not interface_is_up(interface)){
1914
error_t ret_errno = 0, ioctl_errno = 0;
1915
if(not get_flags(interface, &network)){
1917
fprintf_plus(stderr, "Failed to get flags for interface "
1918
"\"%s\"\n", interface);
1922
network.ifr_flags |= IFF_UP; /* set flag */
1924
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1927
perror_plus("socket");
1933
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1935
perror_plus("close");
1942
fprintf_plus(stderr, "Bringing up interface \"%s\"\n",
1946
/* Raise privileges */
1947
ret_errno = raise_privileges();
1950
perror_plus("Failed to raise privileges");
1955
bool restore_loglevel = false;
1957
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1958
messages about the network interface to mess up the prompt */
1959
ret_linux = klogctl(8, NULL, 5);
1960
if(ret_linux == -1){
1961
perror_plus("klogctl");
1963
restore_loglevel = true;
1966
#endif /* __linux__ */
1967
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1968
ioctl_errno = errno;
1970
if(restore_loglevel){
1971
ret_linux = klogctl(7, NULL, 0);
1972
if(ret_linux == -1){
1973
perror_plus("klogctl");
1976
#endif /* __linux__ */
1978
/* If raise_privileges() succeeded above */
1980
/* Lower privileges */
1981
ret_errno = lower_privileges();
1984
perror_plus("Failed to lower privileges");
1988
/* Close the socket */
1989
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1991
perror_plus("close");
1994
if(ret_setflags == -1){
1995
errno = ioctl_errno;
1996
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
2001
fprintf_plus(stderr, "Interface \"%s\" is already up; good\n",
2005
/* Sleep checking until interface is running.
2006
Check every 0.25s, up to total time of delay */
2007
for(int i=0; i < delay * 4; i++){
2008
if(interface_is_running(interface)){
2011
struct timespec sleeptime = { .tv_nsec = 250000000 };
2012
ret = nanosleep(&sleeptime, NULL);
2013
if(ret == -1 and errno != EINTR){
2014
perror_plus("nanosleep");
2022
__attribute__((nonnull, warn_unused_result))
2023
error_t take_down_interface(const char *const interface){
2024
error_t old_errno = errno;
2025
struct ifreq network;
2026
unsigned int if_index = if_nametoindex(interface);
2028
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
2032
if(interface_is_up(interface)){
2033
error_t ret_errno = 0, ioctl_errno = 0;
2034
if(not get_flags(interface, &network) and debug){
2036
fprintf_plus(stderr, "Failed to get flags for interface "
2037
"\"%s\"\n", interface);
2041
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
2043
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
2046
perror_plus("socket");
2052
fprintf_plus(stderr, "Taking down interface \"%s\"\n",
2056
/* Raise privileges */
2057
ret_errno = raise_privileges();
2060
perror_plus("Failed to raise privileges");
2063
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
2064
ioctl_errno = errno;
2066
/* If raise_privileges() succeeded above */
2068
/* Lower privileges */
2069
ret_errno = lower_privileges();
2072
perror_plus("Failed to lower privileges");
2076
/* Close the socket */
2077
int ret = (int)TEMP_FAILURE_RETRY(close(sd));
2079
perror_plus("close");
2082
if(ret_setflags == -1){
2083
errno = ioctl_errno;
2084
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
2089
fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",
2097
int main(int argc, char *argv[]){
2098
mandos_context mc = { .server = NULL, .dh_bits = 1024,
2099
.priority = "SECURE256:!CTYPE-X.509:"
2100
"+CTYPE-OPENPGP", .current_server = NULL,
2101
.interfaces = NULL, .interfaces_size = 0 };
2102
AvahiSServiceBrowser *sb = NULL;
2107
int exitcode = EXIT_SUCCESS;
2108
char *interfaces_to_take_down = NULL;
2109
size_t interfaces_to_take_down_size = 0;
2110
char run_tempdir[] = "/run/tmp/mandosXXXXXX";
2111
char old_tempdir[] = "/tmp/mandosXXXXXX";
2112
char *tempdir = NULL;
2113
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
2114
const char *seckey = PATHDIR "/" SECKEY;
2115
const char *pubkey = PATHDIR "/" PUBKEY;
2116
char *interfaces_hooks = NULL;
2118
bool gnutls_initialized = false;
2119
bool gpgme_initialized = false;
2121
double retry_interval = 10; /* 10s between trying a server and
2122
retrying the same server again */
2124
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
2125
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
2130
/* Lower any group privileges we might have, just to be safe */
2134
perror_plus("setgid");
2137
/* Lower user privileges (temporarily) */
2141
perror_plus("seteuid");
2149
struct argp_option options[] = {
2150
{ .name = "debug", .key = 128,
2151
.doc = "Debug mode", .group = 3 },
2152
{ .name = "connect", .key = 'c',
2153
.arg = "ADDRESS:PORT",
2154
.doc = "Connect directly to a specific Mandos server",
2156
{ .name = "interface", .key = 'i',
2158
.doc = "Network interface that will be used to search for"
2161
{ .name = "seckey", .key = 's',
2163
.doc = "OpenPGP secret key file base name",
2165
{ .name = "pubkey", .key = 'p',
2167
.doc = "OpenPGP public key file base name",
2169
{ .name = "dh-bits", .key = 129,
2171
.doc = "Bit length of the prime number used in the"
2172
" Diffie-Hellman key exchange",
2174
{ .name = "priority", .key = 130,
2176
.doc = "GnuTLS priority string for the TLS handshake",
2178
{ .name = "delay", .key = 131,
2180
.doc = "Maximum delay to wait for interface startup",
2182
{ .name = "retry", .key = 132,
2184
.doc = "Retry interval used when denied by the Mandos server",
2186
{ .name = "network-hook-dir", .key = 133,
2188
.doc = "Directory where network hooks are located",
2191
* These reproduce what we would get without ARGP_NO_HELP
2193
{ .name = "help", .key = '?',
2194
.doc = "Give this help list", .group = -1 },
2195
{ .name = "usage", .key = -3,
2196
.doc = "Give a short usage message", .group = -1 },
2197
{ .name = "version", .key = 'V',
2198
.doc = "Print program version", .group = -1 },
2202
error_t parse_opt(int key, char *arg,
2203
struct argp_state *state){
2206
case 128: /* --debug */
2209
case 'c': /* --connect */
2212
case 'i': /* --interface */
2213
ret_errno = argz_add_sep(&mc.interfaces, &mc.interfaces_size,
2216
argp_error(state, "%s", strerror(ret_errno));
2219
case 's': /* --seckey */
2222
case 'p': /* --pubkey */
2225
case 129: /* --dh-bits */
2227
tmpmax = strtoimax(arg, &tmp, 10);
2228
if(errno != 0 or tmp == arg or *tmp != '\0'
2229
or tmpmax != (typeof(mc.dh_bits))tmpmax){
2230
argp_error(state, "Bad number of DH bits");
2232
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
2234
case 130: /* --priority */
2237
case 131: /* --delay */
2239
delay = strtof(arg, &tmp);
2240
if(errno != 0 or tmp == arg or *tmp != '\0'){
2241
argp_error(state, "Bad delay");
2243
case 132: /* --retry */
2245
retry_interval = strtod(arg, &tmp);
2246
if(errno != 0 or tmp == arg or *tmp != '\0'
2247
or (retry_interval * 1000) > INT_MAX
2248
or retry_interval < 0){
2249
argp_error(state, "Bad retry interval");
2252
case 133: /* --network-hook-dir */
2256
* These reproduce what we would get without ARGP_NO_HELP
2258
case '?': /* --help */
2259
argp_state_help(state, state->out_stream,
2260
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
2261
& ~(unsigned int)ARGP_HELP_EXIT_OK);
2262
case -3: /* --usage */
2263
argp_state_help(state, state->out_stream,
2264
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
2265
case 'V': /* --version */
2266
fprintf_plus(state->out_stream, "%s\n", argp_program_version);
2267
exit(argp_err_exit_status);
2270
return ARGP_ERR_UNKNOWN;
2275
struct argp argp = { .options = options, .parser = parse_opt,
2277
.doc = "Mandos client -- Get and decrypt"
2278
" passwords from a Mandos server" };
2279
ret = argp_parse(&argp, argc, argv,
2280
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
2287
perror_plus("argp_parse");
2288
exitcode = EX_OSERR;
2291
exitcode = EX_USAGE;
2297
/* Work around Debian bug #633582:
2298
<http://bugs.debian.org/633582> */
2300
/* Re-raise privileges */
2301
ret_errno = raise_privileges();
2304
perror_plus("Failed to raise privileges");
2308
if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){
2309
int seckey_fd = open(seckey, O_RDONLY);
2310
if(seckey_fd == -1){
2311
perror_plus("open");
2313
ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));
2315
perror_plus("fstat");
2317
if(S_ISREG(st.st_mode)
2318
and st.st_uid == 0 and st.st_gid == 0){
2319
ret = fchown(seckey_fd, uid, gid);
2321
perror_plus("fchown");
2325
TEMP_FAILURE_RETRY(close(seckey_fd));
2329
if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){
2330
int pubkey_fd = open(pubkey, O_RDONLY);
2331
if(pubkey_fd == -1){
2332
perror_plus("open");
2334
ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));
2336
perror_plus("fstat");
2338
if(S_ISREG(st.st_mode)
2339
and st.st_uid == 0 and st.st_gid == 0){
2340
ret = fchown(pubkey_fd, uid, gid);
2342
perror_plus("fchown");
2346
TEMP_FAILURE_RETRY(close(pubkey_fd));
2350
/* Lower privileges */
2351
ret_errno = lower_privileges();
2354
perror_plus("Failed to lower privileges");
2359
/* Remove invalid interface names (except "none") */
2361
char *interface = NULL;
2362
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2364
if(strcmp(interface, "none") != 0
2365
and if_nametoindex(interface) == 0){
2366
if(interface[0] != '\0'){
2367
fprintf_plus(stderr, "Not using nonexisting interface"
2368
" \"%s\"\n", interface);
2370
argz_delete(&mc.interfaces, &mc.interfaces_size, interface);
2376
/* Run network hooks */
2378
if(mc.interfaces != NULL){
2379
interfaces_hooks = malloc(mc.interfaces_size);
2380
if(interfaces_hooks == NULL){
2381
perror_plus("malloc");
2384
memcpy(interfaces_hooks, mc.interfaces, mc.interfaces_size);
2385
argz_stringify(interfaces_hooks, mc.interfaces_size, (int)',');
2387
run_network_hooks("start", interfaces_hooks != NULL ?
2388
interfaces_hooks : "", delay);
2392
avahi_set_log_function(empty_log);
2395
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
2396
from the signal handler */
2397
/* Initialize the pseudo-RNG for Avahi */
2398
srand((unsigned int) time(NULL));
2399
simple_poll = avahi_simple_poll_new();
2400
if(simple_poll == NULL){
2401
fprintf_plus(stderr,
2402
"Avahi: Failed to create simple poll object.\n");
2403
exitcode = EX_UNAVAILABLE;
2407
sigemptyset(&sigterm_action.sa_mask);
2408
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
2410
perror_plus("sigaddset");
2411
exitcode = EX_OSERR;
2414
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
2416
perror_plus("sigaddset");
2417
exitcode = EX_OSERR;
2420
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
2422
perror_plus("sigaddset");
2423
exitcode = EX_OSERR;
2426
/* Need to check if the handler is SIG_IGN before handling:
2427
| [[info:libc:Initial Signal Actions]] |
2428
| [[info:libc:Basic Signal Handling]] |
2430
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
2432
perror_plus("sigaction");
2435
if(old_sigterm_action.sa_handler != SIG_IGN){
2436
ret = sigaction(SIGINT, &sigterm_action, NULL);
2438
perror_plus("sigaction");
2439
exitcode = EX_OSERR;
2443
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
2445
perror_plus("sigaction");
2448
if(old_sigterm_action.sa_handler != SIG_IGN){
2449
ret = sigaction(SIGHUP, &sigterm_action, NULL);
2451
perror_plus("sigaction");
2452
exitcode = EX_OSERR;
2456
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
2458
perror_plus("sigaction");
2461
if(old_sigterm_action.sa_handler != SIG_IGN){
2462
ret = sigaction(SIGTERM, &sigterm_action, NULL);
2464
perror_plus("sigaction");
2465
exitcode = EX_OSERR;
2470
/* If no interfaces were specified, make a list */
2471
if(mc.interfaces == NULL){
2472
struct dirent **direntries = NULL;
2473
/* Look for any good interfaces */
2474
ret = scandir(sys_class_net, &direntries, good_interface,
2477
/* Add all found interfaces to interfaces list */
2478
for(int i = 0; i < ret; ++i){
2479
ret_errno = argz_add(&mc.interfaces, &mc.interfaces_size,
2480
direntries[i]->d_name);
2483
perror_plus("argz_add");
2484
free(direntries[i]);
2488
fprintf_plus(stderr, "Will use interface \"%s\"\n",
2489
direntries[i]->d_name);
2491
free(direntries[i]);
2498
fprintf_plus(stderr, "Could not find a network interface\n");
2499
exitcode = EXIT_FAILURE;
2504
/* Bring up interfaces which are down, and remove any "none"s */
2506
char *interface = NULL;
2507
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2509
/* If interface name is "none", stop bringing up interfaces.
2510
Also remove all instances of "none" from the list */
2511
if(strcmp(interface, "none") == 0){
2512
argz_delete(&mc.interfaces, &mc.interfaces_size,
2515
while((interface = argz_next(mc.interfaces,
2516
mc.interfaces_size, interface))){
2517
if(strcmp(interface, "none") == 0){
2518
argz_delete(&mc.interfaces, &mc.interfaces_size,
2525
bool interface_was_up = interface_is_up(interface);
2526
errno = bring_up_interface(interface, delay);
2527
if(not interface_was_up){
2529
perror_plus("Failed to bring up interface");
2531
errno = argz_add(&interfaces_to_take_down,
2532
&interfaces_to_take_down_size,
2535
perror_plus("argz_add");
2540
if(debug and (interfaces_to_take_down == NULL)){
2541
fprintf_plus(stderr, "No interfaces were brought up\n");
2545
/* If we only got one interface, explicitly use only that one */
2546
if(argz_count(mc.interfaces, mc.interfaces_size) == 1){
2548
fprintf_plus(stderr, "Using only interface \"%s\"\n",
2551
if_index = (AvahiIfIndex)if_nametoindex(mc.interfaces);
2558
ret = init_gnutls_global(pubkey, seckey, &mc);
2560
fprintf_plus(stderr, "init_gnutls_global failed\n");
2561
exitcode = EX_UNAVAILABLE;
2564
gnutls_initialized = true;
2571
/* Try /run/tmp before /tmp */
2572
tempdir = mkdtemp(run_tempdir);
2573
if(tempdir == NULL and errno == ENOENT){
2575
fprintf_plus(stderr, "Tempdir %s did not work, trying %s\n",
2576
run_tempdir, old_tempdir);
2578
tempdir = mkdtemp(old_tempdir);
2580
if(tempdir == NULL){
2581
perror_plus("mkdtemp");
2589
if(not init_gpgme(pubkey, seckey, tempdir, &mc)){
2590
fprintf_plus(stderr, "init_gpgme failed\n");
2591
exitcode = EX_UNAVAILABLE;
2594
gpgme_initialized = true;
2601
if(connect_to != NULL){
2602
/* Connect directly, do not use Zeroconf */
2603
/* (Mainly meant for debugging) */
2604
char *address = strrchr(connect_to, ':');
2606
if(address == NULL){
2607
fprintf_plus(stderr, "No colon in address\n");
2608
exitcode = EX_USAGE;
2618
tmpmax = strtoimax(address+1, &tmp, 10);
2619
if(errno != 0 or tmp == address+1 or *tmp != '\0'
2620
or tmpmax != (in_port_t)tmpmax){
2621
fprintf_plus(stderr, "Bad port number\n");
2622
exitcode = EX_USAGE;
2630
port = (in_port_t)tmpmax;
2632
/* Colon in address indicates IPv6 */
2634
if(strchr(connect_to, ':') != NULL){
2636
/* Accept [] around IPv6 address - see RFC 5952 */
2637
if(connect_to[0] == '[' and address[-1] == ']')
2645
address = connect_to;
2651
while(not quit_now){
2652
ret = start_mandos_communication(address, port, if_index, af,
2654
if(quit_now or ret == 0){
2658
fprintf_plus(stderr, "Retrying in %d seconds\n",
2659
(int)retry_interval);
2661
sleep((unsigned int)retry_interval);
2665
exitcode = EXIT_SUCCESS;
2676
AvahiServerConfig config;
2677
/* Do not publish any local Zeroconf records */
2678
avahi_server_config_init(&config);
2679
config.publish_hinfo = 0;
2680
config.publish_addresses = 0;
2681
config.publish_workstation = 0;
2682
config.publish_domain = 0;
2684
/* Allocate a new server */
2685
mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),
2686
&config, NULL, NULL, &ret_errno);
2688
/* Free the Avahi configuration data */
2689
avahi_server_config_free(&config);
2692
/* Check if creating the Avahi server object succeeded */
2693
if(mc.server == NULL){
2694
fprintf_plus(stderr, "Failed to create Avahi server: %s\n",
2695
avahi_strerror(ret_errno));
2696
exitcode = EX_UNAVAILABLE;
2704
/* Create the Avahi service browser */
2705
sb = avahi_s_service_browser_new(mc.server, if_index,
2706
AVAHI_PROTO_UNSPEC, "_mandos._tcp",
2707
NULL, 0, browse_callback,
2710
fprintf_plus(stderr, "Failed to create service browser: %s\n",
2711
avahi_strerror(avahi_server_errno(mc.server)));
2712
exitcode = EX_UNAVAILABLE;
2720
/* Run the main loop */
2723
fprintf_plus(stderr, "Starting Avahi loop search\n");
2726
ret = avahi_loop_with_timeout(simple_poll,
2727
(int)(retry_interval * 1000), &mc);
2729
fprintf_plus(stderr, "avahi_loop_with_timeout exited %s\n",
2730
(ret == 0) ? "successfully" : "with error");
2736
fprintf_plus(stderr, "%s exiting\n", argv[0]);
2739
/* Cleanup things */
2740
free(mc.interfaces);
2743
avahi_s_service_browser_free(sb);
2745
if(mc.server != NULL)
2746
avahi_server_free(mc.server);
2748
if(simple_poll != NULL)
2749
avahi_simple_poll_free(simple_poll);
2751
if(gnutls_initialized){
2752
gnutls_certificate_free_credentials(mc.cred);
2753
gnutls_global_deinit();
2754
gnutls_dh_params_deinit(mc.dh_params);
2757
if(gpgme_initialized){
2758
gpgme_release(mc.ctx);
2761
/* Cleans up the circular linked list of Mandos servers the client
2763
if(mc.current_server != NULL){
2764
mc.current_server->prev->next = NULL;
2765
while(mc.current_server != NULL){
2766
server *next = mc.current_server->next;
2768
#pragma GCC diagnostic push
2769
#pragma GCC diagnostic ignored "-Wcast-qual"
2771
free((char *)(mc.current_server->ip));
2773
#pragma GCC diagnostic pop
2775
free(mc.current_server);
2776
mc.current_server = next;
2780
/* Re-raise privileges */
2782
ret_errno = raise_privileges();
2785
perror_plus("Failed to raise privileges");
2788
/* Run network hooks */
2789
run_network_hooks("stop", interfaces_hooks != NULL ?
2790
interfaces_hooks : "", delay);
2792
/* Take down the network interfaces which were brought up */
2794
char *interface = NULL;
2795
while((interface=argz_next(interfaces_to_take_down,
2796
interfaces_to_take_down_size,
2798
ret_errno = take_down_interface(interface);
2801
perror_plus("Failed to take down interface");
2804
if(debug and (interfaces_to_take_down == NULL)){
2805
fprintf_plus(stderr, "No interfaces needed to be taken"
2811
ret_errno = lower_privileges_permanently();
2814
perror_plus("Failed to lower privileges permanently");
2818
free(interfaces_to_take_down);
2819
free(interfaces_hooks);
2821
/* Removes the GPGME temp directory and all files inside */
2822
if(tempdir != NULL){
2823
struct dirent **direntries = NULL;
2824
int tempdir_fd = (int)TEMP_FAILURE_RETRY(open(tempdir, O_RDONLY
2828
if(tempdir_fd == -1){
2829
perror_plus("open");
2832
#if __GLIBC_PREREQ(2, 15)
2833
int numentries = scandirat(tempdir_fd, ".", &direntries,
2834
notdotentries, alphasort);
2835
#else /* not __GLIBC_PREREQ(2, 15) */
2836
int numentries = scandir(tempdir, &direntries, notdotentries,
2838
#endif /* not __GLIBC_PREREQ(2, 15) */
2839
#else /* not __GLIBC__ */
2840
int numentries = scandir(tempdir, &direntries, notdotentries,
2842
#endif /* not __GLIBC__ */
2843
if(numentries >= 0){
2844
for(int i = 0; i < numentries; i++){
2845
ret = unlinkat(tempdir_fd, direntries[i]->d_name, 0);
2847
fprintf_plus(stderr, "unlinkat(open(\"%s\", O_RDONLY),"
2848
" \"%s\", 0): %s\n", tempdir,
2849
direntries[i]->d_name, strerror(errno));
2851
free(direntries[i]);
2854
/* need to clean even if 0 because man page doesn't specify */
2856
if(numentries == -1){
2857
perror_plus("scandir");
2859
ret = rmdir(tempdir);
2860
if(ret == -1 and errno != ENOENT){
2861
perror_plus("rmdir");
2864
TEMP_FAILURE_RETRY(close(tempdir_fd));
2869
sigemptyset(&old_sigterm_action.sa_mask);
2870
old_sigterm_action.sa_handler = SIG_DFL;
2871
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
2872
&old_sigterm_action,
2875
perror_plus("sigaction");
2878
ret = raise(signal_received);
2879
} while(ret != 0 and errno == EINTR);
2881
perror_plus("raise");
2884
TEMP_FAILURE_RETRY(pause());