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".
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* Copyright © 2008-2012 Teddy Hogeborn
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* Copyright © 2008-2012 Björn Påhlsson
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* 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
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* 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.
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see
27
* <http://www.gnu.org/licenses/>.
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* Contact the authors at <mandos@recompile.se>.
32
/* Needed by GPGME, specifically gpgme_data_seek() */
33
#ifndef _LARGEFILE_SOURCE
34
#define _LARGEFILE_SOURCE
36
#ifndef _FILE_OFFSET_BITS
37
#define _FILE_OFFSET_BITS 64
40
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
42
#include <stdio.h> /* fprintf(), stderr, fwrite(),
43
stdout, ferror(), remove() */
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,
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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() */
59
#include <fcntl.h> /* open() */
60
#include <dirent.h> /* opendir(), struct dirent, readdir()
62
#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,
64
#include <errno.h> /* perror(), errno,
65
program_invocation_short_name */
66
#include <time.h> /* nanosleep(), time(), sleep() */
67
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
68
SIOCSIFFLAGS, if_indextoname(),
69
if_nametoindex(), IF_NAMESIZE */
70
#include <netinet/in.h> /* IN6_IS_ADDR_LINKLOCAL,
71
INET_ADDRSTRLEN, INET6_ADDRSTRLEN
73
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
74
getuid(), getgid(), seteuid(),
75
setgid(), pause(), _exit() */
76
#include <arpa/inet.h> /* inet_pton(), htons, inet_ntop() */
77
#include <iso646.h> /* not, or, and */
78
#include <argp.h> /* struct argp_option, error_t, struct
79
argp_state, struct argp,
80
argp_parse(), ARGP_KEY_ARG,
81
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
82
#include <signal.h> /* sigemptyset(), sigaddset(),
83
sigaction(), SIGTERM, sig_atomic_t,
85
#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,
86
EX_NOHOST, EX_IOERR, EX_PROTOCOL */
87
#include <sys/wait.h> /* waitpid(), WIFEXITED(),
88
WEXITSTATUS(), WTERMSIG() */
89
#include <grp.h> /* setgroups() */
90
#include <argz.h> /* argz_add_sep(), argz_next(),
91
argz_delete(), argz_append(),
92
argz_stringify(), argz_add(),
96
#include <sys/klog.h> /* klogctl() */
97
#endif /* __linux__ */
100
/* All Avahi types, constants and functions
103
#include <avahi-core/core.h>
104
#include <avahi-core/lookup.h>
105
#include <avahi-core/log.h>
106
#include <avahi-common/simple-watch.h>
107
#include <avahi-common/malloc.h>
108
#include <avahi-common/error.h>
111
#include <gnutls/gnutls.h> /* All GnuTLS types, constants and
114
init_gnutls_session(),
116
#include <gnutls/openpgp.h>
117
/* gnutls_certificate_set_openpgp_key_file(),
118
GNUTLS_OPENPGP_FMT_BASE64 */
121
#include <gpgme.h> /* All GPGME types, constants and
124
GPGME_PROTOCOL_OpenPGP,
127
#define BUFFER_SIZE 256
129
#define PATHDIR "/conf/conf.d/mandos"
130
#define SECKEY "seckey.txt"
131
#define PUBKEY "pubkey.txt"
132
#define HOOKDIR "/lib/mandos/network-hooks.d"
135
static const char mandos_protocol_version[] = "1";
136
const char *argp_program_version = "mandos-client " VERSION;
137
const char *argp_program_bug_address = "<mandos@recompile.se>";
138
static const char sys_class_net[] = "/sys/class/net";
139
char *connect_to = NULL;
140
const char *hookdir = HOOKDIR;
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/* Doubly linked list that need to be circularly linked when used */
145
typedef struct server{
148
AvahiIfIndex if_index;
150
struct timespec last_seen;
155
/* Used for passing in values through the Avahi callback functions */
157
AvahiSimplePoll *simple_poll;
159
gnutls_certificate_credentials_t cred;
160
unsigned int dh_bits;
161
gnutls_dh_params_t dh_params;
162
const char *priority;
164
server *current_server;
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/* global context so signal handler can reach it*/
168
mandos_context mc = { .simple_poll = NULL, .server = NULL,
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.dh_bits = 1024, .priority = "SECURE256"
170
":!CTYPE-X.509:+CTYPE-OPENPGP",
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.current_server = NULL };
173
sig_atomic_t quit_now = 0;
174
int signal_received = 0;
176
/* Function to use when printing errors */
177
void perror_plus(const char *print_text){
179
fprintf(stderr, "Mandos plugin %s: ",
180
program_invocation_short_name);
185
__attribute__((format (gnu_printf, 2, 3)))
186
int fprintf_plus(FILE *stream, const char *format, ...){
188
va_start (ap, format);
190
TEMP_FAILURE_RETRY(fprintf(stream, "Mandos plugin %s: ",
191
program_invocation_short_name));
192
return TEMP_FAILURE_RETRY(vfprintf(stream, format, ap));
196
* Make additional room in "buffer" for at least BUFFER_SIZE more
197
* bytes. "buffer_capacity" is how much is currently allocated,
198
* "buffer_length" is how much is already used.
200
size_t incbuffer(char **buffer, size_t buffer_length,
201
size_t buffer_capacity){
202
if(buffer_length + BUFFER_SIZE > buffer_capacity){
203
*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
207
buffer_capacity += BUFFER_SIZE;
209
return buffer_capacity;
212
/* Add server to set of servers to retry periodically */
213
bool add_server(const char *ip, in_port_t port, AvahiIfIndex if_index,
216
server *new_server = malloc(sizeof(server));
217
if(new_server == NULL){
218
perror_plus("malloc");
221
*new_server = (server){ .ip = strdup(ip),
223
.if_index = if_index,
225
if(new_server->ip == NULL){
226
perror_plus("strdup");
229
/* Special case of first server */
230
if (mc.current_server == NULL){
231
new_server->next = new_server;
232
new_server->prev = new_server;
233
mc.current_server = new_server;
234
/* Place the new server last in the list */
236
new_server->next = mc.current_server;
237
new_server->prev = mc.current_server->prev;
238
new_server->prev->next = new_server;
239
mc.current_server->prev = new_server;
241
ret = clock_gettime(CLOCK_MONOTONIC, &mc.current_server->last_seen);
243
perror_plus("clock_gettime");
252
static bool init_gpgme(const char *seckey, const char *pubkey,
253
const char *tempdir){
255
gpgme_engine_info_t engine_info;
259
* Helper function to insert pub and seckey to the engine keyring.
261
bool import_key(const char *filename){
264
gpgme_data_t pgp_data;
266
fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
272
rc = gpgme_data_new_from_fd(&pgp_data, fd);
273
if(rc != GPG_ERR_NO_ERROR){
274
fprintf_plus(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
275
gpgme_strsource(rc), gpgme_strerror(rc));
279
rc = gpgme_op_import(mc.ctx, pgp_data);
280
if(rc != GPG_ERR_NO_ERROR){
281
fprintf_plus(stderr, "bad gpgme_op_import: %s: %s\n",
282
gpgme_strsource(rc), gpgme_strerror(rc));
286
ret = (int)TEMP_FAILURE_RETRY(close(fd));
288
perror_plus("close");
290
gpgme_data_release(pgp_data);
295
fprintf_plus(stderr, "Initializing GPGME\n");
299
gpgme_check_version(NULL);
300
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
301
if(rc != GPG_ERR_NO_ERROR){
302
fprintf_plus(stderr, "bad gpgme_engine_check_version: %s: %s\n",
303
gpgme_strsource(rc), gpgme_strerror(rc));
307
/* Set GPGME home directory for the OpenPGP engine only */
308
rc = gpgme_get_engine_info(&engine_info);
309
if(rc != GPG_ERR_NO_ERROR){
310
fprintf_plus(stderr, "bad gpgme_get_engine_info: %s: %s\n",
311
gpgme_strsource(rc), gpgme_strerror(rc));
314
while(engine_info != NULL){
315
if(engine_info->protocol == GPGME_PROTOCOL_OpenPGP){
316
gpgme_set_engine_info(GPGME_PROTOCOL_OpenPGP,
317
engine_info->file_name, tempdir);
320
engine_info = engine_info->next;
322
if(engine_info == NULL){
323
fprintf_plus(stderr, "Could not set GPGME home dir to %s\n",
328
/* Create new GPGME "context" */
329
rc = gpgme_new(&(mc.ctx));
330
if(rc != GPG_ERR_NO_ERROR){
331
fprintf_plus(stderr, "Mandos plugin mandos-client: "
332
"bad gpgme_new: %s: %s\n", gpgme_strsource(rc),
337
if(not import_key(pubkey) or not import_key(seckey)){
345
* Decrypt OpenPGP data.
346
* Returns -1 on error
348
static ssize_t pgp_packet_decrypt(const char *cryptotext,
351
gpgme_data_t dh_crypto, dh_plain;
354
size_t plaintext_capacity = 0;
355
ssize_t plaintext_length = 0;
358
fprintf_plus(stderr, "Trying to decrypt OpenPGP data\n");
361
/* Create new GPGME data buffer from memory cryptotext */
362
rc = gpgme_data_new_from_mem(&dh_crypto, cryptotext, crypto_size,
364
if(rc != GPG_ERR_NO_ERROR){
365
fprintf_plus(stderr, "bad gpgme_data_new_from_mem: %s: %s\n",
366
gpgme_strsource(rc), gpgme_strerror(rc));
370
/* Create new empty GPGME data buffer for the plaintext */
371
rc = gpgme_data_new(&dh_plain);
372
if(rc != GPG_ERR_NO_ERROR){
373
fprintf_plus(stderr, "Mandos plugin mandos-client: "
374
"bad gpgme_data_new: %s: %s\n",
375
gpgme_strsource(rc), gpgme_strerror(rc));
376
gpgme_data_release(dh_crypto);
380
/* Decrypt data from the cryptotext data buffer to the plaintext
382
rc = gpgme_op_decrypt(mc.ctx, dh_crypto, dh_plain);
383
if(rc != GPG_ERR_NO_ERROR){
384
fprintf_plus(stderr, "bad gpgme_op_decrypt: %s: %s\n",
385
gpgme_strsource(rc), gpgme_strerror(rc));
386
plaintext_length = -1;
388
gpgme_decrypt_result_t result;
389
result = gpgme_op_decrypt_result(mc.ctx);
391
fprintf_plus(stderr, "gpgme_op_decrypt_result failed\n");
393
fprintf_plus(stderr, "Unsupported algorithm: %s\n",
394
result->unsupported_algorithm);
395
fprintf_plus(stderr, "Wrong key usage: %u\n",
396
result->wrong_key_usage);
397
if(result->file_name != NULL){
398
fprintf_plus(stderr, "File name: %s\n", result->file_name);
400
gpgme_recipient_t recipient;
401
recipient = result->recipients;
402
while(recipient != NULL){
403
fprintf_plus(stderr, "Public key algorithm: %s\n",
404
gpgme_pubkey_algo_name
405
(recipient->pubkey_algo));
406
fprintf_plus(stderr, "Key ID: %s\n", recipient->keyid);
407
fprintf_plus(stderr, "Secret key available: %s\n",
408
recipient->status == GPG_ERR_NO_SECKEY
410
recipient = recipient->next;
418
fprintf_plus(stderr, "Decryption of OpenPGP data succeeded\n");
421
/* Seek back to the beginning of the GPGME plaintext data buffer */
422
if(gpgme_data_seek(dh_plain, (off_t)0, SEEK_SET) == -1){
423
perror_plus("gpgme_data_seek");
424
plaintext_length = -1;
430
plaintext_capacity = incbuffer(plaintext,
431
(size_t)plaintext_length,
433
if(plaintext_capacity == 0){
434
perror_plus("incbuffer");
435
plaintext_length = -1;
439
ret = gpgme_data_read(dh_plain, *plaintext + plaintext_length,
441
/* Print the data, if any */
447
perror_plus("gpgme_data_read");
448
plaintext_length = -1;
451
plaintext_length += ret;
455
fprintf_plus(stderr, "Decrypted password is: ");
456
for(ssize_t i = 0; i < plaintext_length; i++){
457
fprintf(stderr, "%02hhX ", (*plaintext)[i]);
459
fprintf(stderr, "\n");
464
/* Delete the GPGME cryptotext data buffer */
465
gpgme_data_release(dh_crypto);
467
/* Delete the GPGME plaintext data buffer */
468
gpgme_data_release(dh_plain);
469
return plaintext_length;
472
static const char * safer_gnutls_strerror(int value){
473
const char *ret = gnutls_strerror(value);
479
/* GnuTLS log function callback */
480
static void debuggnutls(__attribute__((unused)) int level,
482
fprintf_plus(stderr, "GnuTLS: %s", string);
485
static int init_gnutls_global(const char *pubkeyfilename,
486
const char *seckeyfilename){
490
fprintf_plus(stderr, "Initializing GnuTLS\n");
493
ret = gnutls_global_init();
494
if(ret != GNUTLS_E_SUCCESS){
495
fprintf_plus(stderr, "GnuTLS global_init: %s\n",
496
safer_gnutls_strerror(ret));
501
/* "Use a log level over 10 to enable all debugging options."
504
gnutls_global_set_log_level(11);
505
gnutls_global_set_log_function(debuggnutls);
508
/* OpenPGP credentials */
509
ret = gnutls_certificate_allocate_credentials(&mc.cred);
510
if(ret != GNUTLS_E_SUCCESS){
511
fprintf_plus(stderr, "GnuTLS memory error: %s\n",
512
safer_gnutls_strerror(ret));
513
gnutls_global_deinit();
518
fprintf_plus(stderr, "Attempting to use OpenPGP public key %s and"
519
" secret key %s as GnuTLS credentials\n",
524
ret = gnutls_certificate_set_openpgp_key_file
525
(mc.cred, pubkeyfilename, seckeyfilename,
526
GNUTLS_OPENPGP_FMT_BASE64);
527
if(ret != GNUTLS_E_SUCCESS){
529
"Error[%d] while reading the OpenPGP key pair ('%s',"
530
" '%s')\n", ret, pubkeyfilename, seckeyfilename);
531
fprintf_plus(stderr, "The GnuTLS error is: %s\n",
532
safer_gnutls_strerror(ret));
536
/* GnuTLS server initialization */
537
ret = gnutls_dh_params_init(&mc.dh_params);
538
if(ret != GNUTLS_E_SUCCESS){
539
fprintf_plus(stderr, "Error in GnuTLS DH parameter"
540
" initialization: %s\n",
541
safer_gnutls_strerror(ret));
544
ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);
545
if(ret != GNUTLS_E_SUCCESS){
546
fprintf_plus(stderr, "Error in GnuTLS prime generation: %s\n",
547
safer_gnutls_strerror(ret));
551
gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);
557
gnutls_certificate_free_credentials(mc.cred);
558
gnutls_global_deinit();
559
gnutls_dh_params_deinit(mc.dh_params);
563
static int init_gnutls_session(gnutls_session_t *session){
565
/* GnuTLS session creation */
567
ret = gnutls_init(session, GNUTLS_SERVER);
571
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
572
if(ret != GNUTLS_E_SUCCESS){
574
"Error in GnuTLS session initialization: %s\n",
575
safer_gnutls_strerror(ret));
581
ret = gnutls_priority_set_direct(*session, mc.priority, &err);
583
gnutls_deinit(*session);
586
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
587
if(ret != GNUTLS_E_SUCCESS){
588
fprintf_plus(stderr, "Syntax error at: %s\n", err);
589
fprintf_plus(stderr, "GnuTLS error: %s\n",
590
safer_gnutls_strerror(ret));
591
gnutls_deinit(*session);
597
ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,
600
gnutls_deinit(*session);
603
} while(ret == GNUTLS_E_INTERRUPTED or ret == GNUTLS_E_AGAIN);
604
if(ret != GNUTLS_E_SUCCESS){
605
fprintf_plus(stderr, "Error setting GnuTLS credentials: %s\n",
606
safer_gnutls_strerror(ret));
607
gnutls_deinit(*session);
611
/* ignore client certificate if any. */
612
gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);
614
gnutls_dh_set_prime_bits(*session, mc.dh_bits);
619
/* Avahi log function callback */
620
static void empty_log(__attribute__((unused)) AvahiLogLevel level,
621
__attribute__((unused)) const char *txt){}
623
/* Called when a Mandos server is found */
624
static int start_mandos_communication(const char *ip, in_port_t port,
625
AvahiIfIndex if_index,
627
int ret, tcp_sd = -1;
630
struct sockaddr_in in;
631
struct sockaddr_in6 in6;
634
char *decrypted_buffer = NULL;
635
size_t buffer_length = 0;
636
size_t buffer_capacity = 0;
639
gnutls_session_t session;
640
int pf; /* Protocol family */
657
fprintf_plus(stderr, "Bad address family: %d\n", af);
662
ret = init_gnutls_session(&session);
668
fprintf_plus(stderr, "Setting up a TCP connection to %s, port %"
669
PRIuMAX "\n", ip, (uintmax_t)port);
672
tcp_sd = socket(pf, SOCK_STREAM, 0);
675
perror_plus("socket");
685
memset(&to, 0, sizeof(to));
687
to.in6.sin6_family = (sa_family_t)af;
688
ret = inet_pton(af, ip, &to.in6.sin6_addr);
690
to.in.sin_family = (sa_family_t)af;
691
ret = inet_pton(af, ip, &to.in.sin_addr);
695
perror_plus("inet_pton");
701
fprintf_plus(stderr, "Bad address: %s\n", ip);
706
to.in6.sin6_port = htons(port);
707
if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */
708
(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower and
710
if(if_index == AVAHI_IF_UNSPEC){
711
fprintf_plus(stderr, "An IPv6 link-local address is"
712
" incomplete without a network interface\n");
716
/* Set the network interface number as scope */
717
to.in6.sin6_scope_id = (uint32_t)if_index;
720
to.in.sin_port = htons(port); /* Spurious warnings from
722
-Wunreachable-code */
731
if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){
732
char interface[IF_NAMESIZE];
733
if(if_indextoname((unsigned int)if_index, interface) == NULL){
734
perror_plus("if_indextoname");
736
fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIuMAX
737
"\n", ip, interface, (uintmax_t)port);
740
fprintf_plus(stderr, "Connection to: %s, port %" PRIuMAX "\n",
741
ip, (uintmax_t)port);
743
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
744
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
747
pcret = inet_ntop(af, &(to.in6.sin6_addr), addrstr,
750
pcret = inet_ntop(af, &(to.in.sin_addr), addrstr,
754
perror_plus("inet_ntop");
756
if(strcmp(addrstr, ip) != 0){
757
fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);
768
ret = connect(tcp_sd, &to.in6, sizeof(to));
770
ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */
773
if ((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){
775
perror_plus("connect");
786
const char *out = mandos_protocol_version;
789
size_t out_size = strlen(out);
790
ret = (int)TEMP_FAILURE_RETRY(write(tcp_sd, out + written,
791
out_size - written));
794
perror_plus("write");
798
written += (size_t)ret;
799
if(written < out_size){
802
if(out == mandos_protocol_version){
817
fprintf_plus(stderr, "Establishing TLS session with %s\n", ip);
825
/* This casting via intptr_t is to eliminate warning about casting
826
an int to a pointer type. This is exactly how the GnuTLS Guile
827
function "set-session-transport-fd!" does it. */
828
gnutls_transport_set_ptr(session,
829
(gnutls_transport_ptr_t)(intptr_t)tcp_sd);
837
ret = gnutls_handshake(session);
842
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
844
if(ret != GNUTLS_E_SUCCESS){
846
fprintf_plus(stderr, "*** GnuTLS Handshake failed ***\n");
853
/* Read OpenPGP packet that contains the wanted password */
856
fprintf_plus(stderr, "Retrieving OpenPGP encrypted password from"
867
buffer_capacity = incbuffer(&buffer, buffer_length,
869
if(buffer_capacity == 0){
871
perror_plus("incbuffer");
881
sret = gnutls_record_recv(session, buffer+buffer_length,
888
case GNUTLS_E_INTERRUPTED:
891
case GNUTLS_E_REHANDSHAKE:
893
ret = gnutls_handshake(session);
899
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
901
fprintf_plus(stderr, "*** GnuTLS Re-handshake failed "
909
fprintf_plus(stderr, "Unknown error while reading data from"
910
" encrypted session with Mandos server\n");
911
gnutls_bye(session, GNUTLS_SHUT_RDWR);
916
buffer_length += (size_t) sret;
921
fprintf_plus(stderr, "Closing TLS session\n");
930
ret = gnutls_bye(session, GNUTLS_SHUT_RDWR);
935
} while(ret == GNUTLS_E_AGAIN or ret == GNUTLS_E_INTERRUPTED);
937
if(buffer_length > 0){
938
ssize_t decrypted_buffer_size;
939
decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,
941
if(decrypted_buffer_size >= 0){
944
while(written < (size_t) decrypted_buffer_size){
950
ret = (int)fwrite(decrypted_buffer + written, 1,
951
(size_t)decrypted_buffer_size - written,
953
if(ret == 0 and ferror(stdout)){
956
fprintf_plus(stderr, "Error writing encrypted data: %s\n",
962
written += (size_t)ret;
968
/* Shutdown procedure */
973
free(decrypted_buffer);
976
ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));
982
perror_plus("close");
984
gnutls_deinit(session);
994
static void resolve_callback(AvahiSServiceResolver *r,
995
AvahiIfIndex interface,
997
AvahiResolverEvent event,
1001
const char *host_name,
1002
const AvahiAddress *address,
1004
AVAHI_GCC_UNUSED AvahiStringList *txt,
1005
AVAHI_GCC_UNUSED AvahiLookupResultFlags
1007
AVAHI_GCC_UNUSED void* userdata){
1012
/* Called whenever a service has been resolved successfully or
1021
case AVAHI_RESOLVER_FAILURE:
1022
fprintf_plus(stderr, "(Avahi Resolver) Failed to resolve service "
1023
"'%s' of type '%s' in domain '%s': %s\n", name, type,
1025
avahi_strerror(avahi_server_errno(mc.server)));
1028
case AVAHI_RESOLVER_FOUND:
1030
char ip[AVAHI_ADDRESS_STR_MAX];
1031
avahi_address_snprint(ip, sizeof(ip), address);
1033
fprintf_plus(stderr, "Mandos server \"%s\" found on %s (%s, %"
1034
PRIdMAX ") on port %" PRIu16 "\n", name,
1035
host_name, ip, (intmax_t)interface, port);
1037
int ret = start_mandos_communication(ip, (in_port_t)port,
1039
avahi_proto_to_af(proto));
1041
avahi_simple_poll_quit(mc.simple_poll);
1043
if(not add_server(ip, (in_port_t)port, interface,
1044
avahi_proto_to_af(proto))){
1045
fprintf_plus(stderr, "Failed to add server \"%s\" to server"
1051
avahi_s_service_resolver_free(r);
1054
static void browse_callback(AvahiSServiceBrowser *b,
1055
AvahiIfIndex interface,
1056
AvahiProtocol protocol,
1057
AvahiBrowserEvent event,
1061
AVAHI_GCC_UNUSED AvahiLookupResultFlags
1063
AVAHI_GCC_UNUSED void* userdata){
1068
/* Called whenever a new services becomes available on the LAN or
1069
is removed from the LAN */
1077
case AVAHI_BROWSER_FAILURE:
1079
fprintf_plus(stderr, "(Avahi browser) %s\n",
1080
avahi_strerror(avahi_server_errno(mc.server)));
1081
avahi_simple_poll_quit(mc.simple_poll);
1084
case AVAHI_BROWSER_NEW:
1085
/* We ignore the returned Avahi resolver object. In the callback
1086
function we free it. If the Avahi server is terminated before
1087
the callback function is called the Avahi server will free the
1090
if(avahi_s_service_resolver_new(mc.server, interface, protocol,
1091
name, type, domain, protocol, 0,
1092
resolve_callback, NULL) == NULL)
1093
fprintf_plus(stderr, "Avahi: Failed to resolve service '%s':"
1095
avahi_strerror(avahi_server_errno(mc.server)));
1098
case AVAHI_BROWSER_REMOVE:
1101
case AVAHI_BROWSER_ALL_FOR_NOW:
1102
case AVAHI_BROWSER_CACHE_EXHAUSTED:
1104
fprintf_plus(stderr, "No Mandos server found, still"
1111
/* Signal handler that stops main loop after SIGTERM */
1112
static void handle_sigterm(int sig){
1117
signal_received = sig;
1118
int old_errno = errno;
1119
/* set main loop to exit */
1120
if(mc.simple_poll != NULL){
1121
avahi_simple_poll_quit(mc.simple_poll);
1126
bool get_flags(const char *ifname, struct ifreq *ifr){
1130
int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1133
perror_plus("socket");
1137
strcpy(ifr->ifr_name, ifname);
1138
ret = ioctl(s, SIOCGIFFLAGS, ifr);
1142
perror_plus("ioctl SIOCGIFFLAGS");
1150
bool good_flags(const char *ifname, const struct ifreq *ifr){
1152
/* Reject the loopback device */
1153
if(ifr->ifr_flags & IFF_LOOPBACK){
1155
fprintf_plus(stderr, "Rejecting loopback interface \"%s\"\n",
1160
/* Accept point-to-point devices only if connect_to is specified */
1161
if(connect_to != NULL and (ifr->ifr_flags & IFF_POINTOPOINT)){
1163
fprintf_plus(stderr, "Accepting point-to-point interface"
1164
" \"%s\"\n", ifname);
1168
/* Otherwise, reject non-broadcast-capable devices */
1169
if(not (ifr->ifr_flags & IFF_BROADCAST)){
1171
fprintf_plus(stderr, "Rejecting non-broadcast interface"
1172
" \"%s\"\n", ifname);
1176
/* Reject non-ARP interfaces (including dummy interfaces) */
1177
if(ifr->ifr_flags & IFF_NOARP){
1179
fprintf_plus(stderr, "Rejecting non-ARP interface \"%s\"\n",
1185
/* Accept this device */
1187
fprintf_plus(stderr, "Interface \"%s\" is good\n", ifname);
1193
* This function determines if a directory entry in /sys/class/net
1194
* corresponds to an acceptable network device.
1195
* (This function is passed to scandir(3) as a filter function.)
1197
int good_interface(const struct dirent *if_entry){
1198
if(if_entry->d_name[0] == '.'){
1203
if(not get_flags(if_entry->d_name, &ifr)){
1205
fprintf_plus(stderr, "Failed to get flags for interface "
1206
"\"%s\"\n", if_entry->d_name);
1211
if(not good_flags(if_entry->d_name, &ifr)){
1218
* This function determines if a network interface is up.
1220
bool interface_is_up(const char *interface){
1222
if(not get_flags(interface, &ifr)){
1224
fprintf_plus(stderr, "Failed to get flags for interface "
1225
"\"%s\"\n", interface);
1230
return (bool)(ifr.ifr_flags & IFF_UP);
1234
* This function determines if a network interface is running
1236
bool interface_is_running(const char *interface){
1238
if(not get_flags(interface, &ifr)){
1240
fprintf_plus(stderr, "Failed to get flags for interface "
1241
"\"%s\"\n", interface);
1246
return (bool)(ifr.ifr_flags & IFF_RUNNING);
1249
int notdotentries(const struct dirent *direntry){
1250
/* Skip "." and ".." */
1251
if(direntry->d_name[0] == '.'
1252
and (direntry->d_name[1] == '\0'
1253
or (direntry->d_name[1] == '.'
1254
and direntry->d_name[2] == '\0'))){
1260
/* Is this directory entry a runnable program? */
1261
int runnable_hook(const struct dirent *direntry){
1266
if((direntry->d_name)[0] == '\0'){
1271
sret = strspn(direntry->d_name, "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
1272
"abcdefghijklmnopqrstuvwxyz"
1275
if((direntry->d_name)[sret] != '\0'){
1276
/* Contains non-allowed characters */
1278
fprintf_plus(stderr, "Ignoring hook \"%s\" with bad name\n",
1284
char *fullname = NULL;
1285
ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);
1287
perror_plus("asprintf");
1291
ret = stat(fullname, &st);
1294
perror_plus("Could not stat hook");
1298
if(not (S_ISREG(st.st_mode))){
1299
/* Not a regular file */
1301
fprintf_plus(stderr, "Ignoring hook \"%s\" - not a file\n",
1306
if(not (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))){
1307
/* Not executable */
1309
fprintf_plus(stderr, "Ignoring hook \"%s\" - not executable\n",
1315
fprintf_plus(stderr, "Hook \"%s\" is acceptable\n",
1321
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){
1323
struct timespec now;
1324
struct timespec waited_time;
1325
intmax_t block_time;
1328
if(mc.current_server == NULL){
1330
fprintf_plus(stderr, "Wait until first server is found."
1333
ret = avahi_simple_poll_iterate(s, -1);
1336
fprintf_plus(stderr, "Check current_server if we should run"
1339
/* the current time */
1340
ret = clock_gettime(CLOCK_MONOTONIC, &now);
1342
perror_plus("clock_gettime");
1345
/* Calculating in ms how long time between now and server
1346
who we visted longest time ago. Now - last seen. */
1347
waited_time.tv_sec = (now.tv_sec
1348
- mc.current_server->last_seen.tv_sec);
1349
waited_time.tv_nsec = (now.tv_nsec
1350
- mc.current_server->last_seen.tv_nsec);
1351
/* total time is 10s/10,000ms.
1352
Converting to s from ms by dividing by 1,000,
1353
and ns to ms by dividing by 1,000,000. */
1354
block_time = ((retry_interval
1355
- ((intmax_t)waited_time.tv_sec * 1000))
1356
- ((intmax_t)waited_time.tv_nsec / 1000000));
1359
fprintf_plus(stderr, "Blocking for %" PRIdMAX " ms\n",
1363
if(block_time <= 0){
1364
ret = start_mandos_communication(mc.current_server->ip,
1365
mc.current_server->port,
1366
mc.current_server->if_index,
1367
mc.current_server->af);
1369
avahi_simple_poll_quit(mc.simple_poll);
1372
ret = clock_gettime(CLOCK_MONOTONIC,
1373
&mc.current_server->last_seen);
1375
perror_plus("clock_gettime");
1378
mc.current_server = mc.current_server->next;
1379
block_time = 0; /* Call avahi to find new Mandos
1380
servers, but don't block */
1383
ret = avahi_simple_poll_iterate(s, (int)block_time);
1386
if (ret > 0 or errno != EINTR){
1387
return (ret != 1) ? ret : 0;
1393
/* Set effective uid to 0, return errno */
1394
error_t raise_privileges(void){
1395
error_t old_errno = errno;
1396
error_t ret_errno = 0;
1397
if(seteuid(0) == -1){
1399
perror_plus("seteuid");
1405
/* Set effective and real user ID to 0. Return errno. */
1406
error_t raise_privileges_permanently(void){
1407
error_t old_errno = errno;
1408
error_t ret_errno = raise_privileges();
1413
if(setuid(0) == -1){
1415
perror_plus("seteuid");
1421
/* Set effective user ID to unprivileged saved user ID */
1422
error_t lower_privileges(void){
1423
error_t old_errno = errno;
1424
error_t ret_errno = 0;
1425
if(seteuid(uid) == -1){
1427
perror_plus("seteuid");
1433
/* Lower privileges permanently */
1434
error_t lower_privileges_permanently(void){
1435
error_t old_errno = errno;
1436
error_t ret_errno = 0;
1437
if(setuid(uid) == -1){
1439
perror_plus("setuid");
1445
bool run_network_hooks(const char *mode, const char *interface,
1447
struct dirent **direntries;
1448
struct dirent *direntry;
1450
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1453
perror_plus("scandir");
1455
int devnull = open("/dev/null", O_RDONLY);
1456
for(int i = 0; i < numhooks; i++){
1457
direntry = direntries[i];
1458
char *fullname = NULL;
1459
ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);
1461
perror_plus("asprintf");
1465
fprintf_plus(stderr, "Running network hook \"%s\"\n",
1468
pid_t hook_pid = fork();
1471
/* Raise privileges */
1472
raise_privileges_permanently();
1477
perror_plus("setgid");
1479
/* Reset supplementary groups */
1481
ret = setgroups(0, NULL);
1483
perror_plus("setgroups");
1485
dup2(devnull, STDIN_FILENO);
1487
dup2(STDERR_FILENO, STDOUT_FILENO);
1488
ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);
1490
perror_plus("setenv");
1493
ret = setenv("DEVICE", interface, 1);
1495
perror_plus("setenv");
1498
ret = setenv("VERBOSITY", debug ? "1" : "0", 1);
1500
perror_plus("setenv");
1503
ret = setenv("MODE", mode, 1);
1505
perror_plus("setenv");
1509
ret = asprintf(&delaystring, "%f", delay);
1511
perror_plus("asprintf");
1514
ret = setenv("DELAY", delaystring, 1);
1517
perror_plus("setenv");
1521
if(connect_to != NULL){
1522
ret = setenv("CONNECT", connect_to, 1);
1524
perror_plus("setenv");
1528
if(execl(fullname, direntry->d_name, mode, NULL) == -1){
1529
perror_plus("execl");
1530
_exit(EXIT_FAILURE);
1534
if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){
1535
perror_plus("waitpid");
1539
if(WIFEXITED(status)){
1540
if(WEXITSTATUS(status) != 0){
1541
fprintf_plus(stderr, "Warning: network hook \"%s\" exited"
1542
" with status %d\n", direntry->d_name,
1543
WEXITSTATUS(status));
1547
} else if(WIFSIGNALED(status)){
1548
fprintf_plus(stderr, "Warning: network hook \"%s\" died by"
1549
" signal %d\n", direntry->d_name,
1554
fprintf_plus(stderr, "Warning: network hook \"%s\""
1555
" crashed\n", direntry->d_name);
1562
fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",
1571
error_t bring_up_interface(const char *const interface,
1574
error_t old_errno = errno;
1575
error_t ret_errno = 0;
1576
int ret, ret_setflags;
1577
struct ifreq network;
1578
unsigned int if_index = if_nametoindex(interface);
1580
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1590
if(not interface_is_up(interface)){
1591
if(not get_flags(interface, &network) and debug){
1593
fprintf_plus(stderr, "Failed to get flags for interface "
1594
"\"%s\"\n", interface);
1597
network.ifr_flags |= IFF_UP;
1599
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1602
perror_plus("socket");
1614
fprintf_plus(stderr, "Bringing up interface \"%s\"\n",
1618
/* Raise priviliges */
1622
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1623
messages about the network interface to mess up the prompt */
1624
int ret_linux = klogctl(8, NULL, 5);
1625
bool restore_loglevel = true;
1626
if(ret_linux == -1){
1627
restore_loglevel = false;
1628
perror_plus("klogctl");
1630
#endif /* __linux__ */
1631
ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1634
if(restore_loglevel){
1635
ret_linux = klogctl(7, NULL, 0);
1636
if(ret_linux == -1){
1637
perror_plus("klogctl");
1640
#endif /* __linux__ */
1642
/* Lower privileges */
1645
/* Close the socket */
1646
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1648
perror_plus("close");
1651
if(ret_setflags == -1){
1653
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1658
fprintf_plus(stderr, "Interface \"%s\" is already up; good\n",
1662
/* Sleep checking until interface is running.
1663
Check every 0.25s, up to total time of delay */
1664
for(int i=0; i < delay * 4; i++){
1665
if(interface_is_running(interface)){
1668
struct timespec sleeptime = { .tv_nsec = 250000000 };
1669
ret = nanosleep(&sleeptime, NULL);
1670
if(ret == -1 and errno != EINTR){
1671
perror_plus("nanosleep");
1679
error_t take_down_interface(const char *const interface){
1681
error_t old_errno = errno;
1682
error_t ret_errno = 0;
1683
int ret, ret_setflags;
1684
struct ifreq network;
1685
unsigned int if_index = if_nametoindex(interface);
1687
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1691
if(interface_is_up(interface)){
1692
if(not get_flags(interface, &network) and debug){
1694
fprintf_plus(stderr, "Failed to get flags for interface "
1695
"\"%s\"\n", interface);
1698
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1700
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1703
perror_plus("socket");
1709
fprintf_plus(stderr, "Taking down interface \"%s\"\n",
1713
/* Raise priviliges */
1716
ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1719
/* Lower privileges */
1722
/* Close the socket */
1723
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1725
perror_plus("close");
1728
if(ret_setflags == -1){
1730
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
1735
fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",
1743
int main(int argc, char *argv[]){
1744
AvahiSServiceBrowser *sb = NULL;
1749
int exitcode = EXIT_SUCCESS;
1750
char *interfaces = NULL;
1751
size_t interfaces_size = 0;
1752
char *interfaces_to_take_down = NULL;
1753
size_t interfaces_to_take_down_size = 0;
1754
char tempdir[] = "/tmp/mandosXXXXXX";
1755
bool tempdir_created = false;
1756
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
1757
const char *seckey = PATHDIR "/" SECKEY;
1758
const char *pubkey = PATHDIR "/" PUBKEY;
1759
char *interfaces_hooks = NULL;
1760
size_t interfaces_hooks_size = 0;
1762
bool gnutls_initialized = false;
1763
bool gpgme_initialized = false;
1765
double retry_interval = 10; /* 10s between trying a server and
1766
retrying the same server again */
1768
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
1769
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
1774
/* Lower any group privileges we might have, just to be safe */
1778
perror_plus("setgid");
1781
/* Lower user privileges (temporarily) */
1785
perror_plus("seteuid");
1793
struct argp_option options[] = {
1794
{ .name = "debug", .key = 128,
1795
.doc = "Debug mode", .group = 3 },
1796
{ .name = "connect", .key = 'c',
1797
.arg = "ADDRESS:PORT",
1798
.doc = "Connect directly to a specific Mandos server",
1800
{ .name = "interface", .key = 'i',
1802
.doc = "Network interface that will be used to search for"
1805
{ .name = "seckey", .key = 's',
1807
.doc = "OpenPGP secret key file base name",
1809
{ .name = "pubkey", .key = 'p',
1811
.doc = "OpenPGP public key file base name",
1813
{ .name = "dh-bits", .key = 129,
1815
.doc = "Bit length of the prime number used in the"
1816
" Diffie-Hellman key exchange",
1818
{ .name = "priority", .key = 130,
1820
.doc = "GnuTLS priority string for the TLS handshake",
1822
{ .name = "delay", .key = 131,
1824
.doc = "Maximum delay to wait for interface startup",
1826
{ .name = "retry", .key = 132,
1828
.doc = "Retry interval used when denied by the Mandos server",
1830
{ .name = "network-hook-dir", .key = 133,
1832
.doc = "Directory where network hooks are located",
1835
* These reproduce what we would get without ARGP_NO_HELP
1837
{ .name = "help", .key = '?',
1838
.doc = "Give this help list", .group = -1 },
1839
{ .name = "usage", .key = -3,
1840
.doc = "Give a short usage message", .group = -1 },
1841
{ .name = "version", .key = 'V',
1842
.doc = "Print program version", .group = -1 },
1846
error_t parse_opt(int key, char *arg,
1847
struct argp_state *state){
1850
case 128: /* --debug */
1853
case 'c': /* --connect */
1856
case 'i': /* --interface */
1857
ret_errno = argz_add_sep(&interfaces, &interfaces_size, arg,
1860
argp_error(state, "%s", strerror(ret_errno));
1863
case 's': /* --seckey */
1866
case 'p': /* --pubkey */
1869
case 129: /* --dh-bits */
1871
tmpmax = strtoimax(arg, &tmp, 10);
1872
if(errno != 0 or tmp == arg or *tmp != '\0'
1873
or tmpmax != (typeof(mc.dh_bits))tmpmax){
1874
argp_error(state, "Bad number of DH bits");
1876
mc.dh_bits = (typeof(mc.dh_bits))tmpmax;
1878
case 130: /* --priority */
1881
case 131: /* --delay */
1883
delay = strtof(arg, &tmp);
1884
if(errno != 0 or tmp == arg or *tmp != '\0'){
1885
argp_error(state, "Bad delay");
1887
case 132: /* --retry */
1889
retry_interval = strtod(arg, &tmp);
1890
if(errno != 0 or tmp == arg or *tmp != '\0'
1891
or (retry_interval * 1000) > INT_MAX
1892
or retry_interval < 0){
1893
argp_error(state, "Bad retry interval");
1896
case 133: /* --network-hook-dir */
1900
* These reproduce what we would get without ARGP_NO_HELP
1902
case '?': /* --help */
1903
argp_state_help(state, state->out_stream,
1904
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
1905
& ~(unsigned int)ARGP_HELP_EXIT_OK);
1906
case -3: /* --usage */
1907
argp_state_help(state, state->out_stream,
1908
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
1909
case 'V': /* --version */
1910
fprintf_plus(state->out_stream, "%s\n", argp_program_version);
1911
exit(argp_err_exit_status);
1914
return ARGP_ERR_UNKNOWN;
1919
struct argp argp = { .options = options, .parser = parse_opt,
1921
.doc = "Mandos client -- Get and decrypt"
1922
" passwords from a Mandos server" };
1923
ret = argp_parse(&argp, argc, argv,
1924
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
1931
perror_plus("argp_parse");
1932
exitcode = EX_OSERR;
1935
exitcode = EX_USAGE;
1941
/* Work around Debian bug #633582:
1942
<http://bugs.debian.org/633582> */
1944
/* Re-raise priviliges */
1945
if(raise_privileges() == 0){
1948
if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){
1949
int seckey_fd = open(seckey, O_RDONLY);
1950
if(seckey_fd == -1){
1951
perror_plus("open");
1953
ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));
1955
perror_plus("fstat");
1957
if(S_ISREG(st.st_mode)
1958
and st.st_uid == 0 and st.st_gid == 0){
1959
ret = fchown(seckey_fd, uid, gid);
1961
perror_plus("fchown");
1965
TEMP_FAILURE_RETRY(close(seckey_fd));
1969
if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){
1970
int pubkey_fd = open(pubkey, O_RDONLY);
1971
if(pubkey_fd == -1){
1972
perror_plus("open");
1974
ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));
1976
perror_plus("fstat");
1978
if(S_ISREG(st.st_mode)
1979
and st.st_uid == 0 and st.st_gid == 0){
1980
ret = fchown(pubkey_fd, uid, gid);
1982
perror_plus("fchown");
1986
TEMP_FAILURE_RETRY(close(pubkey_fd));
1990
/* Lower privileges */
1994
perror_plus("seteuid");
1999
/* Remove empty interface names */
2001
char *interface = NULL;
2002
while((interface = argz_next(interfaces, interfaces_size,
2004
if(if_nametoindex(interface) == 0){
2005
if(interface[0] != '\0' and strcmp(interface, "none") != 0){
2006
fprintf_plus(stderr, "Not using nonexisting interface"
2007
" \"%s\"\n", interface);
2009
argz_delete(&interfaces, &interfaces_size, interface);
2015
/* Run network hooks */
2017
ret_errno = argz_append(&interfaces_hooks, &interfaces_hooks_size,
2018
interfaces, interfaces_size);
2021
perror_plus("argz_append");
2024
argz_stringify(interfaces_hooks, interfaces_hooks_size, (int)',');
2025
if(not run_network_hooks("start", interfaces_hooks, delay)){
2031
avahi_set_log_function(empty_log);
2034
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
2035
from the signal handler */
2036
/* Initialize the pseudo-RNG for Avahi */
2037
srand((unsigned int) time(NULL));
2038
mc.simple_poll = avahi_simple_poll_new();
2039
if(mc.simple_poll == NULL){
2040
fprintf_plus(stderr,
2041
"Avahi: Failed to create simple poll object.\n");
2042
exitcode = EX_UNAVAILABLE;
2046
sigemptyset(&sigterm_action.sa_mask);
2047
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
2049
perror_plus("sigaddset");
2050
exitcode = EX_OSERR;
2053
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
2055
perror_plus("sigaddset");
2056
exitcode = EX_OSERR;
2059
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
2061
perror_plus("sigaddset");
2062
exitcode = EX_OSERR;
2065
/* Need to check if the handler is SIG_IGN before handling:
2066
| [[info:libc:Initial Signal Actions]] |
2067
| [[info:libc:Basic Signal Handling]] |
2069
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
2071
perror_plus("sigaction");
2074
if(old_sigterm_action.sa_handler != SIG_IGN){
2075
ret = sigaction(SIGINT, &sigterm_action, NULL);
2077
perror_plus("sigaction");
2078
exitcode = EX_OSERR;
2082
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
2084
perror_plus("sigaction");
2087
if(old_sigterm_action.sa_handler != SIG_IGN){
2088
ret = sigaction(SIGHUP, &sigterm_action, NULL);
2090
perror_plus("sigaction");
2091
exitcode = EX_OSERR;
2095
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
2097
perror_plus("sigaction");
2100
if(old_sigterm_action.sa_handler != SIG_IGN){
2101
ret = sigaction(SIGTERM, &sigterm_action, NULL);
2103
perror_plus("sigaction");
2104
exitcode = EX_OSERR;
2109
/* If no interfaces were specified, make a list */
2110
if(interfaces == NULL){
2111
struct dirent **direntries;
2112
/* Look for any good interfaces */
2113
ret = scandir(sys_class_net, &direntries, good_interface,
2116
/* Add all found interfaces to interfaces list */
2117
for(int i = 0; i < ret; ++i){
2118
ret_errno = argz_add(&interfaces, &interfaces_size,
2119
direntries[i]->d_name);
2121
perror_plus("argz_add");
2125
fprintf_plus(stderr, "Will use interface \"%s\"\n",
2126
direntries[i]->d_name);
2132
fprintf_plus(stderr, "Could not find a network interface\n");
2133
exitcode = EXIT_FAILURE;
2138
/* If we only got one interface, explicitly use only that one */
2139
if(argz_count(interfaces, interfaces_size) == 1){
2141
fprintf_plus(stderr, "Using only interface \"%s\"\n",
2144
if_index = (AvahiIfIndex)if_nametoindex(interfaces);
2147
/* Bring up interfaces which are down */
2148
if(not (argz_count(interfaces, interfaces_size) == 1
2149
and strcmp(interfaces, "none") == 0)){
2150
char *interface = NULL;
2151
while((interface = argz_next(interfaces, interfaces_size,
2153
bool interface_was_up = interface_is_up(interface);
2154
ret = bring_up_interface(interface, delay);
2155
if(not interface_was_up){
2158
perror_plus("Failed to bring up interface");
2160
ret_errno = argz_add(&interfaces_to_take_down,
2161
&interfaces_to_take_down_size,
2168
interfaces_size = 0;
2169
if(debug and (interfaces_to_take_down == NULL)){
2170
fprintf_plus(stderr, "No interfaces were brought up\n");
2178
ret = init_gnutls_global(pubkey, seckey);
2180
fprintf_plus(stderr, "init_gnutls_global failed\n");
2181
exitcode = EX_UNAVAILABLE;
2184
gnutls_initialized = true;
2191
if(mkdtemp(tempdir) == NULL){
2192
perror_plus("mkdtemp");
2195
tempdir_created = true;
2201
if(not init_gpgme(pubkey, seckey, tempdir)){
2202
fprintf_plus(stderr, "init_gpgme failed\n");
2203
exitcode = EX_UNAVAILABLE;
2206
gpgme_initialized = true;
2213
if(connect_to != NULL){
2214
/* Connect directly, do not use Zeroconf */
2215
/* (Mainly meant for debugging) */
2216
char *address = strrchr(connect_to, ':');
2218
if(address == NULL){
2219
fprintf_plus(stderr, "No colon in address\n");
2220
exitcode = EX_USAGE;
2230
tmpmax = strtoimax(address+1, &tmp, 10);
2231
if(errno != 0 or tmp == address+1 or *tmp != '\0'
2232
or tmpmax != (in_port_t)tmpmax){
2233
fprintf_plus(stderr, "Bad port number\n");
2234
exitcode = EX_USAGE;
2242
port = (in_port_t)tmpmax;
2244
/* Colon in address indicates IPv6 */
2246
if(strchr(connect_to, ':') != NULL){
2248
/* Accept [] around IPv6 address - see RFC 5952 */
2249
if(connect_to[0] == '[' and address[-1] == ']')
2257
address = connect_to;
2263
while(not quit_now){
2264
ret = start_mandos_communication(address, port, if_index, af);
2265
if(quit_now or ret == 0){
2269
fprintf_plus(stderr, "Retrying in %d seconds\n",
2270
(int)retry_interval);
2272
sleep((int)retry_interval);
2276
exitcode = EXIT_SUCCESS;
2287
AvahiServerConfig config;
2288
/* Do not publish any local Zeroconf records */
2289
avahi_server_config_init(&config);
2290
config.publish_hinfo = 0;
2291
config.publish_addresses = 0;
2292
config.publish_workstation = 0;
2293
config.publish_domain = 0;
2295
/* Allocate a new server */
2296
mc.server = avahi_server_new(avahi_simple_poll_get
2297
(mc.simple_poll), &config, NULL,
2300
/* Free the Avahi configuration data */
2301
avahi_server_config_free(&config);
2304
/* Check if creating the Avahi server object succeeded */
2305
if(mc.server == NULL){
2306
fprintf_plus(stderr, "Failed to create Avahi server: %s\n",
2307
avahi_strerror(ret_errno));
2308
exitcode = EX_UNAVAILABLE;
2316
/* Create the Avahi service browser */
2317
sb = avahi_s_service_browser_new(mc.server, if_index,
2318
AVAHI_PROTO_UNSPEC, "_mandos._tcp",
2319
NULL, 0, browse_callback, NULL);
2321
fprintf_plus(stderr, "Failed to create service browser: %s\n",
2322
avahi_strerror(avahi_server_errno(mc.server)));
2323
exitcode = EX_UNAVAILABLE;
2331
/* Run the main loop */
2334
fprintf_plus(stderr, "Starting Avahi loop search\n");
2337
ret = avahi_loop_with_timeout(mc.simple_poll,
2338
(int)(retry_interval * 1000));
2340
fprintf_plus(stderr, "avahi_loop_with_timeout exited %s\n",
2341
(ret == 0) ? "successfully" : "with error");
2347
fprintf_plus(stderr, "%s exiting\n", argv[0]);
2350
/* Cleanup things */
2352
avahi_s_service_browser_free(sb);
2354
if(mc.server != NULL)
2355
avahi_server_free(mc.server);
2357
if(mc.simple_poll != NULL)
2358
avahi_simple_poll_free(mc.simple_poll);
2360
if(gnutls_initialized){
2361
gnutls_certificate_free_credentials(mc.cred);
2362
gnutls_global_deinit();
2363
gnutls_dh_params_deinit(mc.dh_params);
2366
if(gpgme_initialized){
2367
gpgme_release(mc.ctx);
2370
/* Cleans up the circular linked list of Mandos servers the client
2372
if(mc.current_server != NULL){
2373
mc.current_server->prev->next = NULL;
2374
while(mc.current_server != NULL){
2375
server *next = mc.current_server->next;
2376
free(mc.current_server);
2377
mc.current_server = next;
2381
/* Re-raise priviliges */
2385
/* Run network hooks */
2386
run_network_hooks("stop", interfaces_hooks, delay);
2388
/* Take down the network interfaces which were brought up */
2390
char *interface = NULL;
2391
while((interface=argz_next(interfaces_to_take_down,
2392
interfaces_to_take_down_size,
2394
ret_errno = take_down_interface(interface);
2397
perror_plus("Failed to take down interface");
2400
if(debug and (interfaces_to_take_down == NULL)){
2401
fprintf_plus(stderr, "No interfaces needed to be taken"
2406
lower_privileges_permanently();
2409
free(interfaces_to_take_down);
2410
free(interfaces_hooks);
2412
/* Removes the GPGME temp directory and all files inside */
2413
if(tempdir_created){
2414
struct dirent **direntries = NULL;
2415
struct dirent *direntry = NULL;
2416
int numentries = scandir(tempdir, &direntries, notdotentries,
2418
if (numentries > 0){
2419
for(int i = 0; i < numentries; i++){
2420
direntry = direntries[i];
2421
char *fullname = NULL;
2422
ret = asprintf(&fullname, "%s/%s", tempdir,
2425
perror_plus("asprintf");
2428
ret = remove(fullname);
2430
fprintf_plus(stderr, "remove(\"%s\"): %s\n", fullname,
2437
/* need to clean even if 0 because man page doesn't specify */
2439
if (numentries == -1){
2440
perror_plus("scandir");
2442
ret = rmdir(tempdir);
2443
if(ret == -1 and errno != ENOENT){
2444
perror_plus("rmdir");
2449
sigemptyset(&old_sigterm_action.sa_mask);
2450
old_sigterm_action.sa_handler = SIG_DFL;
2451
ret = (int)TEMP_FAILURE_RETRY(sigaction(signal_received,
2452
&old_sigterm_action,
2455
perror_plus("sigaction");
2458
ret = raise(signal_received);
2459
} while(ret != 0 and errno == EINTR);
2461
perror_plus("raise");
2464
TEMP_FAILURE_RETRY(pause());