26
26
* along with this program. If not, see
27
27
* <http://www.gnu.org/licenses/>.
29
* Contact the authors at <mandos@recompile.se>.
29
* Contact the authors at <mandos@fukt.bsnet.se>.
32
32
/* Needed by GPGME, specifically gpgme_data_seek() */
33
#ifndef _LARGEFILE_SOURCE
34
33
#define _LARGEFILE_SOURCE
36
#ifndef _FILE_OFFSET_BITS
37
34
#define _FILE_OFFSET_BITS 64
40
36
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
42
38
#include <stdio.h> /* fprintf(), stderr, fwrite(),
43
stdout, ferror(), remove() */
44
#include <stdint.h> /* uint16_t, uint32_t, intptr_t */
39
stdout, ferror(), sscanf(),
41
#include <stdint.h> /* uint16_t, uint32_t */
45
42
#include <stddef.h> /* NULL, size_t, ssize_t */
46
#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),
48
#include <stdbool.h> /* bool, false, true */
43
#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
45
#include <stdbool.h> /* bool, true */
49
46
#include <string.h> /* memset(), strcmp(), strlen(),
50
47
strerror(), asprintf(), strcpy() */
51
#include <sys/ioctl.h> /* ioctl */
48
#include <sys/ioctl.h> /* ioctl */
52
49
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
53
50
sockaddr_in6, PF_INET6,
54
SOCK_STREAM, uid_t, gid_t, open(),
56
#include <sys/stat.h> /* open(), S_ISREG */
51
SOCK_STREAM, INET6_ADDRSTRLEN,
52
uid_t, gid_t, open(), opendir(),
54
#include <sys/stat.h> /* open() */
57
55
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
58
inet_pton(), connect(),
56
struct in6_addr, inet_pton(),
60
58
#include <fcntl.h> /* open() */
61
59
#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() */
61
#include <inttypes.h> /* PRIu16, intmax_t, SCNdMAX */
62
#include <assert.h> /* assert() */
63
#include <errno.h> /* perror(), errno */
64
#include <time.h> /* nanosleep(), time() */
68
65
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
69
66
SIOCSIFFLAGS, if_indextoname(),
70
67
if_nametoindex(), IF_NAMESIZE */
71
#include <netinet/in.h> /* IN6_IS_ADDR_LINKLOCAL,
72
INET_ADDRSTRLEN, INET6_ADDRSTRLEN
68
#include <netinet/in.h>
74
69
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
75
getuid(), getgid(), seteuid(),
76
setgid(), pause(), _exit() */
77
#include <arpa/inet.h> /* inet_pton(), htons() */
78
#include <iso646.h> /* not, or, and */
70
getuid(), getgid(), setuid(),
72
#include <arpa/inet.h> /* inet_pton(), htons */
73
#include <iso646.h> /* not, and, or */
79
74
#include <argp.h> /* struct argp_option, error_t, struct
80
75
argp_state, struct argp,
81
76
argp_parse(), ARGP_KEY_ARG,
82
77
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
83
#include <signal.h> /* sigemptyset(), sigaddset(),
84
sigaction(), SIGTERM, sig_atomic_t,
86
#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,
87
EX_NOHOST, EX_IOERR, EX_PROTOCOL */
88
#include <sys/wait.h> /* waitpid(), WIFEXITED(),
89
WEXITSTATUS(), WTERMSIG() */
90
#include <grp.h> /* setgroups() */
91
#include <argz.h> /* argz_add_sep(), argz_next(),
92
argz_delete(), argz_append(),
93
argz_stringify(), argz_add(),
95
#include <netdb.h> /* getnameinfo(), NI_NUMERICHOST,
96
EAI_SYSTEM, gai_strerror() */
99
79
#include <sys/klog.h> /* klogctl() */
100
#endif /* __linux__ */
103
83
/* All Avahi types, constants and functions
132
112
#define PATHDIR "/conf/conf.d/mandos"
133
113
#define SECKEY "seckey.txt"
134
114
#define PUBKEY "pubkey.txt"
135
#define HOOKDIR "/lib/mandos/network-hooks.d"
137
116
bool debug = false;
138
117
static const char mandos_protocol_version[] = "1";
139
118
const char *argp_program_version = "mandos-client " VERSION;
140
const char *argp_program_bug_address = "<mandos@recompile.se>";
141
static const char sys_class_net[] = "/sys/class/net";
142
char *connect_to = NULL;
143
const char *hookdir = HOOKDIR;
147
/* Doubly linked list that need to be circularly linked when used */
148
typedef struct server{
151
AvahiIfIndex if_index;
153
struct timespec last_seen;
119
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
158
121
/* Used for passing in values through the Avahi callback functions */
123
AvahiSimplePoll *simple_poll;
160
124
AvahiServer *server;
161
125
gnutls_certificate_credentials_t cred;
162
126
unsigned int dh_bits;
163
127
gnutls_dh_params_t dh_params;
164
128
const char *priority;
166
server *current_server;
168
size_t interfaces_size;
169
130
} mandos_context;
171
/* global so signal handler can reach it*/
172
AvahiSimplePoll *simple_poll;
174
sig_atomic_t quit_now = 0;
175
int signal_received = 0;
177
/* Function to use when printing errors */
178
void perror_plus(const char *print_text){
180
fprintf(stderr, "Mandos plugin %s: ",
181
program_invocation_short_name);
186
__attribute__((format (gnu_printf, 2, 3), nonnull))
187
int fprintf_plus(FILE *stream, const char *format, ...){
189
va_start (ap, format);
191
TEMP_FAILURE_RETRY(fprintf(stream, "Mandos plugin %s: ",
192
program_invocation_short_name));
193
return (int)TEMP_FAILURE_RETRY(vfprintf(stream, format, ap));
197
* Make additional room in "buffer" for at least BUFFER_SIZE more
198
* bytes. "buffer_capacity" is how much is currently allocated,
133
* Make room in "buffer" for at least BUFFER_SIZE additional bytes.
134
* "buffer_capacity" is how much is currently allocated,
199
135
* "buffer_length" is how much is already used.
201
__attribute__((nonnull, warn_unused_result))
202
size_t incbuffer(char **buffer, size_t buffer_length,
203
size_t buffer_capacity){
137
size_t adjustbuffer(char **buffer, size_t buffer_length,
138
size_t buffer_capacity){
204
139
if(buffer_length + BUFFER_SIZE > buffer_capacity){
205
char *new_buf = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
207
int old_errno = errno;
140
*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
214
144
buffer_capacity += BUFFER_SIZE;
216
146
return buffer_capacity;
219
/* Add server to set of servers to retry periodically */
220
__attribute__((nonnull, warn_unused_result))
221
bool add_server(const char *ip, in_port_t port, AvahiIfIndex if_index,
222
int af, server **current_server){
224
server *new_server = malloc(sizeof(server));
225
if(new_server == NULL){
226
perror_plus("malloc");
229
*new_server = (server){ .ip = strdup(ip),
231
.if_index = if_index,
233
if(new_server->ip == NULL){
234
perror_plus("strdup");
237
ret = clock_gettime(CLOCK_MONOTONIC, &(new_server->last_seen));
239
perror_plus("clock_gettime");
242
/* Special case of first server */
243
if(*current_server == NULL){
244
new_server->next = new_server;
245
new_server->prev = new_server;
246
*current_server = new_server;
248
/* Place the new server last in the list */
249
new_server->next = *current_server;
250
new_server->prev = (*current_server)->prev;
251
new_server->prev->next = new_server;
252
(*current_server)->prev = new_server;
258
150
* Initialize GPGME.
260
__attribute__((nonnull, warn_unused_result))
261
static bool init_gpgme(const char *seckey, const char *pubkey,
262
const char *tempdir, mandos_context *mc){
152
static bool init_gpgme(mandos_context *mc, const char *seckey,
153
const char *pubkey, const char *tempdir){
263
155
gpgme_error_t rc;
264
156
gpgme_engine_info_t engine_info;
267
160
* Helper function to insert pub and seckey to the engine keyring.
269
162
bool import_key(const char *filename){
272
164
gpgme_data_t pgp_data;
274
166
fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
280
172
rc = gpgme_data_new_from_fd(&pgp_data, fd);
281
173
if(rc != GPG_ERR_NO_ERROR){
282
fprintf_plus(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
283
gpgme_strsource(rc), gpgme_strerror(rc));
174
fprintf(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
175
gpgme_strsource(rc), gpgme_strerror(rc));
287
179
rc = gpgme_op_import(mc->ctx, pgp_data);
288
180
if(rc != GPG_ERR_NO_ERROR){
289
fprintf_plus(stderr, "bad gpgme_op_import: %s: %s\n",
290
gpgme_strsource(rc), gpgme_strerror(rc));
181
fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
182
gpgme_strsource(rc), gpgme_strerror(rc));
294
186
ret = (int)TEMP_FAILURE_RETRY(close(fd));
296
perror_plus("close");
298
190
gpgme_data_release(pgp_data);
303
fprintf_plus(stderr, "Initializing GPGME\n");
195
fprintf(stderr, "Initialize gpgme\n");
307
199
gpgme_check_version(NULL);
308
200
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
309
201
if(rc != GPG_ERR_NO_ERROR){
310
fprintf_plus(stderr, "bad gpgme_engine_check_version: %s: %s\n",
311
gpgme_strsource(rc), gpgme_strerror(rc));
202
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
203
gpgme_strsource(rc), gpgme_strerror(rc));
315
/* Set GPGME home directory for the OpenPGP engine only */
207
/* Set GPGME home directory for the OpenPGP engine only */
316
208
rc = gpgme_get_engine_info(&engine_info);
317
209
if(rc != GPG_ERR_NO_ERROR){
318
fprintf_plus(stderr, "bad gpgme_get_engine_info: %s: %s\n",
319
gpgme_strsource(rc), gpgme_strerror(rc));
210
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
211
gpgme_strsource(rc), gpgme_strerror(rc));
322
214
while(engine_info != NULL){
637
507
__attribute__((unused)) const char *txt){}
639
509
/* Called when a Mandos server is found */
640
__attribute__((nonnull, warn_unused_result))
641
static int start_mandos_communication(const char *ip, in_port_t port,
510
static int start_mandos_communication(const char *ip, uint16_t port,
642
511
AvahiIfIndex if_index,
643
int af, mandos_context *mc){
644
int ret, tcp_sd = -1;
646
struct sockaddr_storage to;
515
union { struct sockaddr in; struct sockaddr_in6 in6; } to;
647
516
char *buffer = NULL;
648
char *decrypted_buffer = NULL;
517
char *decrypted_buffer;
649
518
size_t buffer_length = 0;
650
519
size_t buffer_capacity = 0;
520
ssize_t decrypted_buffer_size;
523
char interface[IF_NAMESIZE];
653
524
gnutls_session_t session;
654
int pf; /* Protocol family */
671
fprintf_plus(stderr, "Bad address family: %d\n", af);
676
/* If the interface is specified and we have a list of interfaces */
677
if(if_index != AVAHI_IF_UNSPEC and mc->interfaces != NULL){
678
/* Check if the interface is one of the interfaces we are using */
681
char *interface = NULL;
682
while((interface=argz_next(mc->interfaces, mc->interfaces_size,
684
if(if_nametoindex(interface) == (unsigned int)if_index){
691
/* This interface does not match any in the list, so we don't
692
connect to the server */
694
char interface[IF_NAMESIZE];
695
if(if_indextoname((unsigned int)if_index, interface) == NULL){
696
perror_plus("if_indextoname");
698
fprintf_plus(stderr, "Skipping server on non-used interface"
700
if_indextoname((unsigned int)if_index,
708
ret = init_gnutls_session(&session, mc);
526
ret = init_gnutls_session(mc, &session);
714
fprintf_plus(stderr, "Setting up a TCP connection to %s, port %"
715
PRIuMAX "\n", ip, (uintmax_t)port);
532
fprintf(stderr, "Setting up a tcp connection to %s, port %" PRIu16
718
tcp_sd = socket(pf, SOCK_STREAM, 0);
536
tcp_sd = socket(PF_INET6, SOCK_STREAM, 0);
721
perror_plus("socket");
543
if(if_indextoname((unsigned int)if_index, interface) == NULL){
544
perror("if_indextoname");
547
fprintf(stderr, "Binding to interface %s\n", interface);
731
550
memset(&to, 0, sizeof(to));
733
((struct sockaddr_in6 *)&to)->sin6_family = (sa_family_t)af;
734
ret = inet_pton(af, ip, &((struct sockaddr_in6 *)&to)->sin6_addr);
736
((struct sockaddr_in *)&to)->sin_family = (sa_family_t)af;
737
ret = inet_pton(af, ip, &((struct sockaddr_in *)&to)->sin_addr);
551
to.in6.sin6_family = AF_INET6;
552
/* It would be nice to have a way to detect if we were passed an
553
IPv4 address here. Now we assume an IPv6 address. */
554
ret = inet_pton(AF_INET6, ip, &to.in6.sin6_addr);
741
perror_plus("inet_pton");
747
fprintf_plus(stderr, "Bad address: %s\n", ip);
752
((struct sockaddr_in6 *)&to)->sin6_port = htons(port);
753
if(IN6_IS_ADDR_LINKLOCAL
754
(&((struct sockaddr_in6 *)&to)->sin6_addr)){
755
if(if_index == AVAHI_IF_UNSPEC){
756
fprintf_plus(stderr, "An IPv6 link-local address is"
757
" incomplete without a network interface\n");
761
/* Set the network interface number as scope */
762
((struct sockaddr_in6 *)&to)->sin6_scope_id = (uint32_t)if_index;
765
((struct sockaddr_in *)&to)->sin_port = htons(port);
560
fprintf(stderr, "Bad address: %s\n", ip);
563
to.in6.sin6_port = htons(port); /* Spurious warnings from
565
-Wunreachable-code */
567
to.in6.sin6_scope_id = (uint32_t)if_index;
774
if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){
775
char interface[IF_NAMESIZE];
776
if(if_indextoname((unsigned int)if_index, interface) == NULL){
777
perror_plus("if_indextoname");
779
fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIuMAX
780
"\n", ip, interface, (uintmax_t)port);
570
fprintf(stderr, "Connection to: %s, port %" PRIu16 "\n", ip,
572
char addrstr[INET6_ADDRSTRLEN] = "";
573
if(inet_ntop(to.in6.sin6_family, &(to.in6.sin6_addr), addrstr,
574
sizeof(addrstr)) == NULL){
577
if(strcmp(addrstr, ip) != 0){
578
fprintf(stderr, "Canonical address form: %s\n", addrstr);
783
fprintf_plus(stderr, "Connection to: %s, port %" PRIuMAX "\n",
784
ip, (uintmax_t)port);
786
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
787
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
789
ret = getnameinfo((struct sockaddr *)&to,
790
sizeof(struct sockaddr_in6),
791
addrstr, sizeof(addrstr), NULL, 0,
794
ret = getnameinfo((struct sockaddr *)&to,
795
sizeof(struct sockaddr_in),
796
addrstr, sizeof(addrstr), NULL, 0,
799
if(ret == EAI_SYSTEM){
800
perror_plus("getnameinfo");
801
} else if(ret != 0) {
802
fprintf_plus(stderr, "getnameinfo: %s", gai_strerror(ret));
803
} else if(strcmp(addrstr, ip) != 0){
804
fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);
814
ret = connect(tcp_sd, (struct sockaddr *)&to,
815
sizeof(struct sockaddr_in6));
817
ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */
818
sizeof(struct sockaddr_in));
583
ret = connect(tcp_sd, &to.in, sizeof(to));
821
if((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){
823
perror_plus("connect");
834
589
const char *out = mandos_protocol_version;
1156
815
case AVAHI_BROWSER_ALL_FOR_NOW:
1157
816
case AVAHI_BROWSER_CACHE_EXHAUSTED:
1159
fprintf_plus(stderr, "No Mandos server found, still"
818
fprintf(stderr, "No Mandos server found, still searching...\n");
1166
/* Signal handler that stops main loop after SIGTERM */
1167
static void handle_sigterm(int sig){
1172
signal_received = sig;
1173
int old_errno = errno;
1174
/* set main loop to exit */
1175
if(simple_poll != NULL){
1176
avahi_simple_poll_quit(simple_poll);
1181
__attribute__((nonnull, warn_unused_result))
1182
bool get_flags(const char *ifname, struct ifreq *ifr){
1186
int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1189
perror_plus("socket");
1193
strcpy(ifr->ifr_name, ifname);
1194
ret = ioctl(s, SIOCGIFFLAGS, ifr);
1198
perror_plus("ioctl SIOCGIFFLAGS");
1206
__attribute__((nonnull, warn_unused_result))
1207
bool good_flags(const char *ifname, const struct ifreq *ifr){
1209
/* Reject the loopback device */
1210
if(ifr->ifr_flags & IFF_LOOPBACK){
1212
fprintf_plus(stderr, "Rejecting loopback interface \"%s\"\n",
1217
/* Accept point-to-point devices only if connect_to is specified */
1218
if(connect_to != NULL and (ifr->ifr_flags & IFF_POINTOPOINT)){
1220
fprintf_plus(stderr, "Accepting point-to-point interface"
1221
" \"%s\"\n", ifname);
1225
/* Otherwise, reject non-broadcast-capable devices */
1226
if(not (ifr->ifr_flags & IFF_BROADCAST)){
1228
fprintf_plus(stderr, "Rejecting non-broadcast interface"
1229
" \"%s\"\n", ifname);
1233
/* Reject non-ARP interfaces (including dummy interfaces) */
1234
if(ifr->ifr_flags & IFF_NOARP){
1236
fprintf_plus(stderr, "Rejecting non-ARP interface \"%s\"\n",
1242
/* Accept this device */
1244
fprintf_plus(stderr, "Interface \"%s\" is good\n", ifname);
1250
* This function determines if a directory entry in /sys/class/net
1251
* corresponds to an acceptable network device.
1252
* (This function is passed to scandir(3) as a filter function.)
1254
__attribute__((nonnull, warn_unused_result))
1255
int good_interface(const struct dirent *if_entry){
1256
if(if_entry->d_name[0] == '.'){
1261
if(not get_flags(if_entry->d_name, &ifr)){
1263
fprintf_plus(stderr, "Failed to get flags for interface "
1264
"\"%s\"\n", if_entry->d_name);
1269
if(not good_flags(if_entry->d_name, &ifr)){
1276
* This function determines if a network interface is up.
1278
__attribute__((nonnull, warn_unused_result))
1279
bool interface_is_up(const char *interface){
1281
if(not get_flags(interface, &ifr)){
1283
fprintf_plus(stderr, "Failed to get flags for interface "
1284
"\"%s\"\n", interface);
1289
return (bool)(ifr.ifr_flags & IFF_UP);
1293
* This function determines if a network interface is running
1295
__attribute__((nonnull, warn_unused_result))
1296
bool interface_is_running(const char *interface){
1298
if(not get_flags(interface, &ifr)){
1300
fprintf_plus(stderr, "Failed to get flags for interface "
1301
"\"%s\"\n", interface);
1306
return (bool)(ifr.ifr_flags & IFF_RUNNING);
1309
__attribute__((nonnull, pure, warn_unused_result))
1310
int notdotentries(const struct dirent *direntry){
1311
/* Skip "." and ".." */
1312
if(direntry->d_name[0] == '.'
1313
and (direntry->d_name[1] == '\0'
1314
or (direntry->d_name[1] == '.'
1315
and direntry->d_name[2] == '\0'))){
1321
/* Is this directory entry a runnable program? */
1322
__attribute__((nonnull, warn_unused_result))
1323
int runnable_hook(const struct dirent *direntry){
1328
if((direntry->d_name)[0] == '\0'){
1333
sret = strspn(direntry->d_name, "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
1334
"abcdefghijklmnopqrstuvwxyz"
1337
if((direntry->d_name)[sret] != '\0'){
1338
/* Contains non-allowed characters */
1340
fprintf_plus(stderr, "Ignoring hook \"%s\" with bad name\n",
1346
char *fullname = NULL;
1347
ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);
1349
perror_plus("asprintf");
1353
ret = stat(fullname, &st);
1356
perror_plus("Could not stat hook");
1360
if(not (S_ISREG(st.st_mode))){
1361
/* Not a regular file */
1363
fprintf_plus(stderr, "Ignoring hook \"%s\" - not a file\n",
1368
if(not (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))){
1369
/* Not executable */
1371
fprintf_plus(stderr, "Ignoring hook \"%s\" - not executable\n",
1377
fprintf_plus(stderr, "Hook \"%s\" is acceptable\n",
1383
__attribute__((nonnull, warn_unused_result))
1384
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,
1385
mandos_context *mc){
1387
struct timespec now;
1388
struct timespec waited_time;
1389
intmax_t block_time;
1392
if(mc->current_server == NULL){
1394
fprintf_plus(stderr, "Wait until first server is found."
1397
ret = avahi_simple_poll_iterate(s, -1);
1400
fprintf_plus(stderr, "Check current_server if we should run"
1403
/* the current time */
1404
ret = clock_gettime(CLOCK_MONOTONIC, &now);
1406
perror_plus("clock_gettime");
1409
/* Calculating in ms how long time between now and server
1410
who we visted longest time ago. Now - last seen. */
1411
waited_time.tv_sec = (now.tv_sec
1412
- mc->current_server->last_seen.tv_sec);
1413
waited_time.tv_nsec = (now.tv_nsec
1414
- mc->current_server->last_seen.tv_nsec);
1415
/* total time is 10s/10,000ms.
1416
Converting to s from ms by dividing by 1,000,
1417
and ns to ms by dividing by 1,000,000. */
1418
block_time = ((retry_interval
1419
- ((intmax_t)waited_time.tv_sec * 1000))
1420
- ((intmax_t)waited_time.tv_nsec / 1000000));
1423
fprintf_plus(stderr, "Blocking for %" PRIdMAX " ms\n",
1427
if(block_time <= 0){
1428
ret = start_mandos_communication(mc->current_server->ip,
1429
mc->current_server->port,
1430
mc->current_server->if_index,
1431
mc->current_server->af, mc);
1433
avahi_simple_poll_quit(s);
1436
ret = clock_gettime(CLOCK_MONOTONIC,
1437
&mc->current_server->last_seen);
1439
perror_plus("clock_gettime");
1442
mc->current_server = mc->current_server->next;
1443
block_time = 0; /* Call avahi to find new Mandos
1444
servers, but don't block */
1447
ret = avahi_simple_poll_iterate(s, (int)block_time);
1450
if(ret > 0 or errno != EINTR){
1451
return (ret != 1) ? ret : 0;
1457
/* Set effective uid to 0, return errno */
1458
__attribute__((warn_unused_result))
1459
error_t raise_privileges(void){
1460
error_t old_errno = errno;
1461
error_t ret_errno = 0;
1462
if(seteuid(0) == -1){
1464
perror_plus("seteuid");
1470
/* Set effective and real user ID to 0. Return errno. */
1471
__attribute__((warn_unused_result))
1472
error_t raise_privileges_permanently(void){
1473
error_t old_errno = errno;
1474
error_t ret_errno = raise_privileges();
1479
if(setuid(0) == -1){
1481
perror_plus("seteuid");
1487
/* Set effective user ID to unprivileged saved user ID */
1488
__attribute__((warn_unused_result))
1489
error_t lower_privileges(void){
1490
error_t old_errno = errno;
1491
error_t ret_errno = 0;
1492
if(seteuid(uid) == -1){
1494
perror_plus("seteuid");
1500
/* Lower privileges permanently */
1501
__attribute__((warn_unused_result))
1502
error_t lower_privileges_permanently(void){
1503
error_t old_errno = errno;
1504
error_t ret_errno = 0;
1505
if(setuid(uid) == -1){
1507
perror_plus("setuid");
1513
__attribute__((nonnull))
1514
void run_network_hooks(const char *mode, const char *interface,
1516
struct dirent **direntries;
1517
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1520
if(errno == ENOENT){
1522
fprintf_plus(stderr, "Network hook directory \"%s\" not"
1523
" found\n", hookdir);
1526
perror_plus("scandir");
1529
struct dirent *direntry;
1531
int devnull = open("/dev/null", O_RDONLY);
1532
for(int i = 0; i < numhooks; i++){
1533
direntry = direntries[i];
1534
char *fullname = NULL;
1535
ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);
1537
perror_plus("asprintf");
1541
fprintf_plus(stderr, "Running network hook \"%s\"\n",
1544
pid_t hook_pid = fork();
1547
/* Raise privileges */
1548
if(raise_privileges_permanently() != 0){
1549
perror_plus("Failed to raise privileges");
1556
perror_plus("setgid");
1559
/* Reset supplementary groups */
1561
ret = setgroups(0, NULL);
1563
perror_plus("setgroups");
1566
ret = dup2(devnull, STDIN_FILENO);
1568
perror_plus("dup2(devnull, STDIN_FILENO)");
1571
ret = close(devnull);
1573
perror_plus("close");
1576
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
1578
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
1581
ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);
1583
perror_plus("setenv");
1586
ret = setenv("DEVICE", interface, 1);
1588
perror_plus("setenv");
1591
ret = setenv("VERBOSITY", debug ? "1" : "0", 1);
1593
perror_plus("setenv");
1596
ret = setenv("MODE", mode, 1);
1598
perror_plus("setenv");
1602
ret = asprintf(&delaystring, "%f", (double)delay);
1604
perror_plus("asprintf");
1607
ret = setenv("DELAY", delaystring, 1);
1610
perror_plus("setenv");
1614
if(connect_to != NULL){
1615
ret = setenv("CONNECT", connect_to, 1);
1617
perror_plus("setenv");
1621
if(execl(fullname, direntry->d_name, mode, NULL) == -1){
1622
perror_plus("execl");
1623
_exit(EXIT_FAILURE);
1627
if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){
1628
perror_plus("waitpid");
1632
if(WIFEXITED(status)){
1633
if(WEXITSTATUS(status) != 0){
1634
fprintf_plus(stderr, "Warning: network hook \"%s\" exited"
1635
" with status %d\n", direntry->d_name,
1636
WEXITSTATUS(status));
1640
} else if(WIFSIGNALED(status)){
1641
fprintf_plus(stderr, "Warning: network hook \"%s\" died by"
1642
" signal %d\n", direntry->d_name,
1647
fprintf_plus(stderr, "Warning: network hook \"%s\""
1648
" crashed\n", direntry->d_name);
1655
fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",
1663
__attribute__((nonnull, warn_unused_result))
1664
error_t bring_up_interface(const char *const interface,
1666
error_t old_errno = errno;
1668
struct ifreq network;
1669
unsigned int if_index = if_nametoindex(interface);
1671
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1681
if(not interface_is_up(interface)){
1682
error_t ret_errno = 0, ioctl_errno = 0;
1683
if(not get_flags(interface, &network)){
1685
fprintf_plus(stderr, "Failed to get flags for interface "
1686
"\"%s\"\n", interface);
1690
network.ifr_flags |= IFF_UP; /* set flag */
1692
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1695
perror_plus("socket");
1701
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1703
perror_plus("close");
1710
fprintf_plus(stderr, "Bringing up interface \"%s\"\n",
1714
/* Raise privileges */
1715
ret_errno = raise_privileges();
1716
bool restore_loglevel = false;
1718
perror_plus("Failed to raise privileges");
1723
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1724
messages about the network interface to mess up the prompt */
1725
ret_linux = klogctl(8, NULL, 5);
1726
if(ret_linux == -1){
1727
perror_plus("klogctl");
1729
restore_loglevel = true;
1732
#endif /* __linux__ */
1733
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1734
ioctl_errno = errno;
1736
if(restore_loglevel){
1737
ret_linux = klogctl(7, NULL, 0);
1738
if(ret_linux == -1){
1739
perror_plus("klogctl");
1742
#endif /* __linux__ */
1744
/* If raise_privileges() succeeded above */
1746
/* Lower privileges */
1747
ret_errno = lower_privileges();
1750
perror_plus("Failed to lower privileges");
1754
/* Close the socket */
1755
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1757
perror_plus("close");
1760
if(ret_setflags == -1){
1761
errno = ioctl_errno;
1762
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1767
fprintf_plus(stderr, "Interface \"%s\" is already up; good\n",
1771
/* Sleep checking until interface is running.
1772
Check every 0.25s, up to total time of delay */
1773
for(int i=0; i < delay * 4; i++){
1774
if(interface_is_running(interface)){
1777
struct timespec sleeptime = { .tv_nsec = 250000000 };
1778
ret = nanosleep(&sleeptime, NULL);
1779
if(ret == -1 and errno != EINTR){
1780
perror_plus("nanosleep");
1788
__attribute__((nonnull, warn_unused_result))
1789
error_t take_down_interface(const char *const interface){
1790
error_t old_errno = errno;
1791
struct ifreq network;
1792
unsigned int if_index = if_nametoindex(interface);
1794
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1798
if(interface_is_up(interface)){
1799
error_t ret_errno = 0, ioctl_errno = 0;
1800
if(not get_flags(interface, &network) and debug){
1802
fprintf_plus(stderr, "Failed to get flags for interface "
1803
"\"%s\"\n", interface);
1807
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1809
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1812
perror_plus("socket");
1818
fprintf_plus(stderr, "Taking down interface \"%s\"\n",
1822
/* Raise privileges */
1823
ret_errno = raise_privileges();
1825
perror_plus("Failed to raise privileges");
1827
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1828
ioctl_errno = errno;
1830
/* If raise_privileges() succeeded above */
1832
/* Lower privileges */
1833
ret_errno = lower_privileges();
1836
perror_plus("Failed to lower privileges");
1840
/* Close the socket */
1841
int ret = (int)TEMP_FAILURE_RETRY(close(sd));
1843
perror_plus("close");
1846
if(ret_setflags == -1){
1847
errno = ioctl_errno;
1848
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
1853
fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",
1861
824
int main(int argc, char *argv[]){
1862
mandos_context mc = { .server = NULL, .dh_bits = 1024,
1863
.priority = "SECURE256:!CTYPE-X.509:"
1864
"+CTYPE-OPENPGP", .current_server = NULL,
1865
.interfaces = NULL, .interfaces_size = 0 };
1866
825
AvahiSServiceBrowser *sb = NULL;
1869
828
intmax_t tmpmax;
1871
830
int exitcode = EXIT_SUCCESS;
1872
char *interfaces_to_take_down = NULL;
1873
size_t interfaces_to_take_down_size = 0;
831
const char *interface = "eth0";
832
struct ifreq network;
836
char *connect_to = NULL;
1874
837
char tempdir[] = "/tmp/mandosXXXXXX";
1875
838
bool tempdir_created = false;
1876
839
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
1877
840
const char *seckey = PATHDIR "/" SECKEY;
1878
841
const char *pubkey = PATHDIR "/" PUBKEY;
1879
char *interfaces_hooks = NULL;
843
mandos_context mc = { .simple_poll = NULL, .server = NULL,
844
.dh_bits = 1024, .priority = "SECURE256"
845
":!CTYPE-X.509:+CTYPE-OPENPGP" };
1881
846
bool gnutls_initialized = false;
1882
847
bool gpgme_initialized = false;
1884
double retry_interval = 10; /* 10s between trying a server and
1885
retrying the same server again */
1887
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
1888
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
1893
/* Lower any group privileges we might have, just to be safe */
1897
perror_plus("setgid");
1900
/* Lower user privileges (temporarily) */
1904
perror_plus("seteuid");
1912
851
struct argp_option options[] = {
1998
915
mc.priority = arg;
2000
917
case 131: /* --delay */
2002
delay = strtof(arg, &tmp);
2003
if(errno != 0 or tmp == arg or *tmp != '\0'){
2004
argp_error(state, "Bad delay");
2006
case 132: /* --retry */
2008
retry_interval = strtod(arg, &tmp);
2009
if(errno != 0 or tmp == arg or *tmp != '\0'
2010
or (retry_interval * 1000) > INT_MAX
2011
or retry_interval < 0){
2012
argp_error(state, "Bad retry interval");
2015
case 133: /* --network-hook-dir */
2019
* These reproduce what we would get without ARGP_NO_HELP
2021
case '?': /* --help */
2022
argp_state_help(state, state->out_stream,
2023
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
2024
& ~(unsigned int)ARGP_HELP_EXIT_OK);
2025
case -3: /* --usage */
2026
argp_state_help(state, state->out_stream,
2027
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
2028
case 'V': /* --version */
2029
fprintf_plus(state->out_stream, "%s\n", argp_program_version);
2030
exit(argp_err_exit_status);
918
ret = sscanf(arg, "%lf%n", &delay, &numchars);
919
if(ret < 1 or arg[numchars] != '\0'){
920
fprintf(stderr, "Bad delay\n");
2033
929
return ARGP_ERR_UNKNOWN;
2038
934
struct argp argp = { .options = options, .parser = parse_opt,
2040
936
.doc = "Mandos client -- Get and decrypt"
2041
937
" passwords from a Mandos server" };
2042
ret = argp_parse(&argp, argc, argv,
2043
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
2050
perror_plus("argp_parse");
2051
exitcode = EX_OSERR;
2054
exitcode = EX_USAGE;
2060
/* Work around Debian bug #633582:
2061
<http://bugs.debian.org/633582> */
2063
/* Re-raise privileges */
2064
ret_errno = raise_privileges();
2067
perror_plus("Failed to raise privileges");
2071
if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){
2072
int seckey_fd = open(seckey, O_RDONLY);
2073
if(seckey_fd == -1){
2074
perror_plus("open");
2076
ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));
2078
perror_plus("fstat");
2080
if(S_ISREG(st.st_mode)
2081
and st.st_uid == 0 and st.st_gid == 0){
2082
ret = fchown(seckey_fd, uid, gid);
2084
perror_plus("fchown");
2088
TEMP_FAILURE_RETRY(close(seckey_fd));
2092
if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){
2093
int pubkey_fd = open(pubkey, O_RDONLY);
2094
if(pubkey_fd == -1){
2095
perror_plus("open");
2097
ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));
2099
perror_plus("fstat");
2101
if(S_ISREG(st.st_mode)
2102
and st.st_uid == 0 and st.st_gid == 0){
2103
ret = fchown(pubkey_fd, uid, gid);
2105
perror_plus("fchown");
2109
TEMP_FAILURE_RETRY(close(pubkey_fd));
2113
/* Lower privileges */
2114
ret_errno = lower_privileges();
2117
perror_plus("Failed to lower privileges");
2122
/* Remove invalid interface names (except "none") */
2124
char *interface = NULL;
2125
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2127
if(strcmp(interface, "none") != 0
2128
and if_nametoindex(interface) == 0){
2129
if(interface[0] != '\0'){
2130
fprintf_plus(stderr, "Not using nonexisting interface"
2131
" \"%s\"\n", interface);
2133
argz_delete(&mc.interfaces, &mc.interfaces_size, interface);
2139
/* Run network hooks */
2141
if(mc.interfaces != NULL){
2142
interfaces_hooks = malloc(mc.interfaces_size);
2143
if(interfaces_hooks == NULL){
2144
perror_plus("malloc");
938
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
939
if(ret == ARGP_ERR_UNKNOWN){
940
fprintf(stderr, "Unknown error while parsing arguments\n");
941
exitcode = EXIT_FAILURE;
946
/* If the interface is down, bring it up */
949
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
950
messages to mess up the prompt */
951
ret = klogctl(8, NULL, 5);
957
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
960
exitcode = EXIT_FAILURE;
962
ret = klogctl(7, NULL, 0);
969
strcpy(network.ifr_name, interface);
970
ret = ioctl(sd, SIOCGIFFLAGS, &network);
972
perror("ioctl SIOCGIFFLAGS");
974
ret = klogctl(7, NULL, 0);
979
exitcode = EXIT_FAILURE;
982
if((network.ifr_flags & IFF_UP) == 0){
983
network.ifr_flags |= IFF_UP;
984
ret = ioctl(sd, SIOCSIFFLAGS, &network);
986
perror("ioctl SIOCSIFFLAGS");
987
exitcode = EXIT_FAILURE;
989
ret = klogctl(7, NULL, 0);
2147
memcpy(interfaces_hooks, mc.interfaces, mc.interfaces_size);
2148
argz_stringify(interfaces_hooks, mc.interfaces_size, (int)',');
2150
run_network_hooks("start", interfaces_hooks != NULL ?
2151
interfaces_hooks : "", delay);
2155
avahi_set_log_function(empty_log);
2158
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
2159
from the signal handler */
2160
/* Initialize the pseudo-RNG for Avahi */
2161
srand((unsigned int) time(NULL));
2162
simple_poll = avahi_simple_poll_new();
2163
if(simple_poll == NULL){
2164
fprintf_plus(stderr,
2165
"Avahi: Failed to create simple poll object.\n");
2166
exitcode = EX_UNAVAILABLE;
2170
sigemptyset(&sigterm_action.sa_mask);
2171
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
2173
perror_plus("sigaddset");
2174
exitcode = EX_OSERR;
2177
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
2179
perror_plus("sigaddset");
2180
exitcode = EX_OSERR;
2183
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
2185
perror_plus("sigaddset");
2186
exitcode = EX_OSERR;
2189
/* Need to check if the handler is SIG_IGN before handling:
2190
| [[info:libc:Initial Signal Actions]] |
2191
| [[info:libc:Basic Signal Handling]] |
2193
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
2195
perror_plus("sigaction");
2198
if(old_sigterm_action.sa_handler != SIG_IGN){
2199
ret = sigaction(SIGINT, &sigterm_action, NULL);
2201
perror_plus("sigaction");
2202
exitcode = EX_OSERR;
2206
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
2208
perror_plus("sigaction");
2211
if(old_sigterm_action.sa_handler != SIG_IGN){
2212
ret = sigaction(SIGHUP, &sigterm_action, NULL);
2214
perror_plus("sigaction");
2215
exitcode = EX_OSERR;
2219
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
2221
perror_plus("sigaction");
2224
if(old_sigterm_action.sa_handler != SIG_IGN){
2225
ret = sigaction(SIGTERM, &sigterm_action, NULL);
2227
perror_plus("sigaction");
2228
exitcode = EX_OSERR;
2233
/* If no interfaces were specified, make a list */
2234
if(mc.interfaces == NULL){
2235
struct dirent **direntries;
2236
/* Look for any good interfaces */
2237
ret = scandir(sys_class_net, &direntries, good_interface,
2240
/* Add all found interfaces to interfaces list */
2241
for(int i = 0; i < ret; ++i){
2242
ret_errno = argz_add(&mc.interfaces, &mc.interfaces_size,
2243
direntries[i]->d_name);
2246
perror_plus("argz_add");
2250
fprintf_plus(stderr, "Will use interface \"%s\"\n",
2251
direntries[i]->d_name);
2257
fprintf_plus(stderr, "Could not find a network interface\n");
2258
exitcode = EXIT_FAILURE;
2263
/* Bring up interfaces which are down, and remove any "none"s */
2265
char *interface = NULL;
2266
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2268
/* If interface name is "none", stop bringing up interfaces.
2269
Also remove all instances of "none" from the list */
2270
if(strcmp(interface, "none") == 0){
2271
argz_delete(&mc.interfaces, &mc.interfaces_size,
2274
while((interface = argz_next(mc.interfaces,
2275
mc.interfaces_size, interface))){
2276
if(strcmp(interface, "none") == 0){
2277
argz_delete(&mc.interfaces, &mc.interfaces_size,
997
/* sleep checking until interface is running */
998
for(int i=0; i < delay * 4; i++){
999
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1001
perror("ioctl SIOCGIFFLAGS");
1002
} else if(network.ifr_flags & IFF_RUNNING){
2284
bool interface_was_up = interface_is_up(interface);
2285
errno = bring_up_interface(interface, delay);
2286
if(not interface_was_up){
2288
perror_plus("Failed to bring up interface");
2290
errno = argz_add(&interfaces_to_take_down,
2291
&interfaces_to_take_down_size,
2294
perror_plus("argz_add");
1005
struct timespec sleeptime = { .tv_nsec = 250000000 };
1006
ret = nanosleep(&sleeptime, NULL);
1007
if(ret == -1 and errno != EINTR){
1008
perror("nanosleep");
2299
if(debug and (interfaces_to_take_down == NULL)){
2300
fprintf_plus(stderr, "No interfaces were brought up\n");
2304
/* If we only got one interface, explicitly use only that one */
2305
if(argz_count(mc.interfaces, mc.interfaces_size) == 1){
2307
fprintf_plus(stderr, "Using only interface \"%s\"\n",
2310
if_index = (AvahiIfIndex)if_nametoindex(mc.interfaces);
2317
ret = init_gnutls_global(pubkey, seckey, &mc);
2319
fprintf_plus(stderr, "init_gnutls_global failed\n");
2320
exitcode = EX_UNAVAILABLE;
1011
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1016
/* Restores kernel loglevel to default */
1017
ret = klogctl(7, NULL, 0);
1037
ret = init_gnutls_global(&mc, pubkey, seckey);
1039
fprintf(stderr, "init_gnutls_global failed\n");
1040
exitcode = EXIT_FAILURE;
2323
1043
gnutls_initialized = true;
2330
1046
if(mkdtemp(tempdir) == NULL){
2331
perror_plus("mkdtemp");
2334
1050
tempdir_created = true;
2340
if(not init_gpgme(pubkey, seckey, tempdir, &mc)){
2341
fprintf_plus(stderr, "init_gpgme failed\n");
2342
exitcode = EX_UNAVAILABLE;
1052
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
1053
fprintf(stderr, "init_gpgme failed\n");
1054
exitcode = EXIT_FAILURE;
2345
1057
gpgme_initialized = true;
1060
if_index = (AvahiIfIndex) if_nametoindex(interface);
1062
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1063
exitcode = EXIT_FAILURE;