26
26
* along with this program. If not, see
27
27
* <http://www.gnu.org/licenses/>.
29
* Contact the authors at <mandos@fukt.bsnet.se>.
29
* Contact the authors at <mandos@recompile.se>.
32
32
/* Needed by GPGME, specifically gpgme_data_seek() */
33
#ifndef _LARGEFILE_SOURCE
33
34
#define _LARGEFILE_SOURCE
36
#ifndef _FILE_OFFSET_BITS
34
37
#define _FILE_OFFSET_BITS 64
36
40
#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */
38
42
#include <stdio.h> /* fprintf(), stderr, fwrite(),
39
stdout, ferror(), sscanf(),
41
#include <stdint.h> /* uint16_t, uint32_t */
43
stdout, ferror(), remove() */
44
#include <stdint.h> /* uint16_t, uint32_t, intptr_t */
42
45
#include <stddef.h> /* NULL, size_t, ssize_t */
43
#include <stdlib.h> /* free(), EXIT_SUCCESS, EXIT_FAILURE,
45
#include <stdbool.h> /* bool, true */
46
#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),
48
#include <stdbool.h> /* bool, false, true */
46
49
#include <string.h> /* memset(), strcmp(), strlen(),
47
50
strerror(), asprintf(), strcpy() */
48
#include <sys/ioctl.h> /* ioctl */
51
#include <sys/ioctl.h> /* ioctl */
49
52
#include <sys/types.h> /* socket(), inet_pton(), sockaddr,
50
53
sockaddr_in6, PF_INET6,
51
SOCK_STREAM, INET6_ADDRSTRLEN,
52
uid_t, gid_t, open(), opendir(),
54
#include <sys/stat.h> /* open() */
54
SOCK_STREAM, uid_t, gid_t, open(),
56
#include <sys/stat.h> /* open(), S_ISREG */
55
57
#include <sys/socket.h> /* socket(), struct sockaddr_in6,
56
struct in6_addr, inet_pton(),
58
inet_pton(), connect(),
58
60
#include <fcntl.h> /* open() */
59
61
#include <dirent.h> /* opendir(), struct dirent, readdir()
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() */
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() */
65
68
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
66
69
SIOCSIFFLAGS, if_indextoname(),
67
70
if_nametoindex(), IF_NAMESIZE */
68
#include <netinet/in.h>
71
#include <netinet/in.h> /* IN6_IS_ADDR_LINKLOCAL,
72
INET_ADDRSTRLEN, INET6_ADDRSTRLEN
69
74
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
70
getuid(), getgid(), setuid(),
72
#include <arpa/inet.h> /* inet_pton(), htons */
73
#include <iso646.h> /* not, and, or */
75
getuid(), getgid(), seteuid(),
76
setgid(), pause(), _exit() */
77
#include <arpa/inet.h> /* inet_pton(), htons() */
78
#include <iso646.h> /* not, or, and */
74
79
#include <argp.h> /* struct argp_option, error_t, struct
75
80
argp_state, struct argp,
76
81
argp_parse(), ARGP_KEY_ARG,
77
82
ARGP_KEY_END, ARGP_ERR_UNKNOWN */
83
#include <signal.h> /* sigemptyset(), sigaddset(),
84
sigaction(), SIGTERM, sig_atomic_t,
86
#include <sysexits.h> /* EX_OSERR, EX_USAGE, EX_UNAVAILABLE,
87
EX_NOHOST, EX_IOERR, EX_PROTOCOL */
88
#include <sys/wait.h> /* waitpid(), WIFEXITED(),
89
WEXITSTATUS(), WTERMSIG() */
90
#include <grp.h> /* setgroups() */
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() */
79
99
#include <sys/klog.h> /* klogctl() */
100
#endif /* __linux__ */
83
103
/* All Avahi types, constants and functions
112
132
#define PATHDIR "/conf/conf.d/mandos"
113
133
#define SECKEY "seckey.txt"
114
134
#define PUBKEY "pubkey.txt"
135
#define HOOKDIR "/lib/mandos/network-hooks.d"
116
137
bool debug = false;
117
138
static const char mandos_protocol_version[] = "1";
118
139
const char *argp_program_version = "mandos-client " VERSION;
119
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
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;
121
158
/* Used for passing in values through the Avahi callback functions */
123
AvahiSimplePoll *simple_poll;
124
160
AvahiServer *server;
125
161
gnutls_certificate_credentials_t cred;
126
162
unsigned int dh_bits;
127
163
gnutls_dh_params_t dh_params;
128
164
const char *priority;
166
server *current_server;
168
size_t interfaces_size;
130
169
} 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));
133
* Make room in "buffer" for at least BUFFER_SIZE additional bytes.
134
* "buffer_capacity" is how much is currently allocated,
197
* Make additional room in "buffer" for at least BUFFER_SIZE more
198
* bytes. "buffer_capacity" is how much is currently allocated,
135
199
* "buffer_length" is how much is already used.
137
size_t adjustbuffer(char **buffer, size_t buffer_length,
138
size_t buffer_capacity){
201
__attribute__((nonnull, warn_unused_result))
202
size_t incbuffer(char **buffer, size_t buffer_length,
203
size_t buffer_capacity){
139
204
if(buffer_length + BUFFER_SIZE > buffer_capacity){
140
*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
205
char *new_buf = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
207
int old_errno = errno;
144
214
buffer_capacity += BUFFER_SIZE;
146
216
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;
150
258
* Initialize GPGME.
152
static bool init_gpgme(mandos_context *mc, const char *seckey,
153
const char *pubkey, const char *tempdir){
260
__attribute__((nonnull, warn_unused_result))
261
static bool init_gpgme(const char * const seckey,
262
const char * const pubkey,
263
const char * const tempdir,
155
265
gpgme_error_t rc;
156
266
gpgme_engine_info_t engine_info;
160
269
* Helper function to insert pub and seckey to the engine keyring.
162
bool import_key(const char *filename){
271
bool import_key(const char * const filename){
164
274
gpgme_data_t pgp_data;
166
276
fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
172
282
rc = gpgme_data_new_from_fd(&pgp_data, fd);
173
283
if(rc != GPG_ERR_NO_ERROR){
174
fprintf(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
175
gpgme_strsource(rc), gpgme_strerror(rc));
284
fprintf_plus(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
285
gpgme_strsource(rc), gpgme_strerror(rc));
179
289
rc = gpgme_op_import(mc->ctx, pgp_data);
180
290
if(rc != GPG_ERR_NO_ERROR){
181
fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
182
gpgme_strsource(rc), gpgme_strerror(rc));
291
fprintf_plus(stderr, "bad gpgme_op_import: %s: %s\n",
292
gpgme_strsource(rc), gpgme_strerror(rc));
186
296
ret = (int)TEMP_FAILURE_RETRY(close(fd));
298
perror_plus("close");
190
300
gpgme_data_release(pgp_data);
195
fprintf(stderr, "Initialize gpgme\n");
305
fprintf_plus(stderr, "Initializing GPGME\n");
199
309
gpgme_check_version(NULL);
200
310
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
201
311
if(rc != GPG_ERR_NO_ERROR){
202
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
203
gpgme_strsource(rc), gpgme_strerror(rc));
312
fprintf_plus(stderr, "bad gpgme_engine_check_version: %s: %s\n",
313
gpgme_strsource(rc), gpgme_strerror(rc));
207
/* Set GPGME home directory for the OpenPGP engine only */
317
/* Set GPGME home directory for the OpenPGP engine only */
208
318
rc = gpgme_get_engine_info(&engine_info);
209
319
if(rc != GPG_ERR_NO_ERROR){
210
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
211
gpgme_strsource(rc), gpgme_strerror(rc));
320
fprintf_plus(stderr, "bad gpgme_get_engine_info: %s: %s\n",
321
gpgme_strsource(rc), gpgme_strerror(rc));
214
324
while(engine_info != NULL){
507
639
__attribute__((unused)) const char *txt){}
509
641
/* Called when a Mandos server is found */
510
static int start_mandos_communication(const char *ip, uint16_t port,
642
__attribute__((nonnull, warn_unused_result))
643
static int start_mandos_communication(const char *ip, in_port_t port,
511
644
AvahiIfIndex if_index,
645
int af, mandos_context *mc){
646
int ret, tcp_sd = -1;
515
union { struct sockaddr in; struct sockaddr_in6 in6; } to;
648
struct sockaddr_storage to;
516
649
char *buffer = NULL;
517
char *decrypted_buffer;
650
char *decrypted_buffer = NULL;
518
651
size_t buffer_length = 0;
519
652
size_t buffer_capacity = 0;
520
ssize_t decrypted_buffer_size;
523
char interface[IF_NAMESIZE];
524
655
gnutls_session_t session;
526
ret = init_gnutls_session(mc, &session);
656
int pf; /* Protocol family */
673
fprintf_plus(stderr, "Bad address family: %d\n", af);
678
/* If the interface is specified and we have a list of interfaces */
679
if(if_index != AVAHI_IF_UNSPEC and mc->interfaces != NULL){
680
/* Check if the interface is one of the interfaces we are using */
683
char *interface = NULL;
684
while((interface=argz_next(mc->interfaces, mc->interfaces_size,
686
if(if_nametoindex(interface) == (unsigned int)if_index){
693
/* This interface does not match any in the list, so we don't
694
connect to the server */
696
char interface[IF_NAMESIZE];
697
if(if_indextoname((unsigned int)if_index, interface) == NULL){
698
perror_plus("if_indextoname");
700
fprintf_plus(stderr, "Skipping server on non-used interface"
702
if_indextoname((unsigned int)if_index,
710
ret = init_gnutls_session(&session, mc);
532
fprintf(stderr, "Setting up a tcp connection to %s, port %" PRIu16
716
fprintf_plus(stderr, "Setting up a TCP connection to %s, port %"
717
PRIuMAX "\n", ip, (uintmax_t)port);
536
tcp_sd = socket(PF_INET6, SOCK_STREAM, 0);
720
tcp_sd = socket(pf, SOCK_STREAM, 0);
723
perror_plus("socket");
543
if(if_indextoname((unsigned int)if_index, interface) == NULL){
544
perror("if_indextoname");
547
fprintf(stderr, "Binding to interface %s\n", interface);
550
733
memset(&to, 0, sizeof(to));
551
to.in6.sin6_family = AF_INET6;
552
/* It would be nice to have a way to detect if we were passed an
553
IPv4 address here. Now we assume an IPv6 address. */
554
ret = inet_pton(AF_INET6, ip, &to.in6.sin6_addr);
735
((struct sockaddr_in6 *)&to)->sin6_family = (sa_family_t)af;
736
ret = inet_pton(af, ip, &((struct sockaddr_in6 *)&to)->sin6_addr);
738
((struct sockaddr_in *)&to)->sin_family = (sa_family_t)af;
739
ret = inet_pton(af, ip, &((struct sockaddr_in *)&to)->sin_addr);
743
perror_plus("inet_pton");
560
fprintf(stderr, "Bad address: %s\n", ip);
563
to.in6.sin6_port = htons(port); /* Spurious warnings from
565
-Wunreachable-code */
749
fprintf_plus(stderr, "Bad address: %s\n", ip);
754
((struct sockaddr_in6 *)&to)->sin6_port = htons(port);
755
if(IN6_IS_ADDR_LINKLOCAL
756
(&((struct sockaddr_in6 *)&to)->sin6_addr)){
757
if(if_index == AVAHI_IF_UNSPEC){
758
fprintf_plus(stderr, "An IPv6 link-local address is"
759
" incomplete without a network interface\n");
763
/* Set the network interface number as scope */
764
((struct sockaddr_in6 *)&to)->sin6_scope_id = (uint32_t)if_index;
767
((struct sockaddr_in *)&to)->sin_port = htons(port);
567
to.in6.sin6_scope_id = (uint32_t)if_index;
570
fprintf(stderr, "Connection to: %s, port %" PRIu16 "\n", ip,
572
char addrstr[INET6_ADDRSTRLEN] = "";
573
if(inet_ntop(to.in6.sin6_family, &(to.in6.sin6_addr), addrstr,
574
sizeof(addrstr)) == NULL){
577
if(strcmp(addrstr, ip) != 0){
578
fprintf(stderr, "Canonical address form: %s\n", addrstr);
776
if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){
777
char interface[IF_NAMESIZE];
778
if(if_indextoname((unsigned int)if_index, interface) == NULL){
779
perror_plus("if_indextoname");
781
fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIuMAX
782
"\n", ip, interface, (uintmax_t)port);
583
ret = connect(tcp_sd, &to.in, sizeof(to));
785
fprintf_plus(stderr, "Connection to: %s, port %" PRIuMAX "\n",
786
ip, (uintmax_t)port);
788
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
789
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
791
ret = getnameinfo((struct sockaddr *)&to,
792
sizeof(struct sockaddr_in6),
793
addrstr, sizeof(addrstr), NULL, 0,
796
ret = getnameinfo((struct sockaddr *)&to,
797
sizeof(struct sockaddr_in),
798
addrstr, sizeof(addrstr), NULL, 0,
801
if(ret == EAI_SYSTEM){
802
perror_plus("getnameinfo");
803
} else if(ret != 0) {
804
fprintf_plus(stderr, "getnameinfo: %s", gai_strerror(ret));
805
} else if(strcmp(addrstr, ip) != 0){
806
fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);
816
ret = connect(tcp_sd, (struct sockaddr *)&to,
817
sizeof(struct sockaddr_in6));
819
ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */
820
sizeof(struct sockaddr_in));
823
if((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){
825
perror_plus("connect");
589
836
const char *out = mandos_protocol_version;
815
1158
case AVAHI_BROWSER_ALL_FOR_NOW:
816
1159
case AVAHI_BROWSER_CACHE_EXHAUSTED:
818
fprintf(stderr, "No Mandos server found, still searching...\n");
1161
fprintf_plus(stderr, "No Mandos server found, still"
1168
/* Signal handler that stops main loop after SIGTERM */
1169
static void handle_sigterm(int sig){
1174
signal_received = sig;
1175
int old_errno = errno;
1176
/* set main loop to exit */
1177
if(simple_poll != NULL){
1178
avahi_simple_poll_quit(simple_poll);
1183
__attribute__((nonnull, warn_unused_result))
1184
bool get_flags(const char *ifname, struct ifreq *ifr){
1188
int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1191
perror_plus("socket");
1195
strcpy(ifr->ifr_name, ifname);
1196
ret = ioctl(s, SIOCGIFFLAGS, ifr);
1200
perror_plus("ioctl SIOCGIFFLAGS");
1208
__attribute__((nonnull, warn_unused_result))
1209
bool good_flags(const char *ifname, const struct ifreq *ifr){
1211
/* Reject the loopback device */
1212
if(ifr->ifr_flags & IFF_LOOPBACK){
1214
fprintf_plus(stderr, "Rejecting loopback interface \"%s\"\n",
1219
/* Accept point-to-point devices only if connect_to is specified */
1220
if(connect_to != NULL and (ifr->ifr_flags & IFF_POINTOPOINT)){
1222
fprintf_plus(stderr, "Accepting point-to-point interface"
1223
" \"%s\"\n", ifname);
1227
/* Otherwise, reject non-broadcast-capable devices */
1228
if(not (ifr->ifr_flags & IFF_BROADCAST)){
1230
fprintf_plus(stderr, "Rejecting non-broadcast interface"
1231
" \"%s\"\n", ifname);
1235
/* Reject non-ARP interfaces (including dummy interfaces) */
1236
if(ifr->ifr_flags & IFF_NOARP){
1238
fprintf_plus(stderr, "Rejecting non-ARP interface \"%s\"\n",
1244
/* Accept this device */
1246
fprintf_plus(stderr, "Interface \"%s\" is good\n", ifname);
1252
* This function determines if a directory entry in /sys/class/net
1253
* corresponds to an acceptable network device.
1254
* (This function is passed to scandir(3) as a filter function.)
1256
__attribute__((nonnull, warn_unused_result))
1257
int good_interface(const struct dirent *if_entry){
1258
if(if_entry->d_name[0] == '.'){
1263
if(not get_flags(if_entry->d_name, &ifr)){
1265
fprintf_plus(stderr, "Failed to get flags for interface "
1266
"\"%s\"\n", if_entry->d_name);
1271
if(not good_flags(if_entry->d_name, &ifr)){
1278
* This function determines if a network interface is up.
1280
__attribute__((nonnull, warn_unused_result))
1281
bool interface_is_up(const char *interface){
1283
if(not get_flags(interface, &ifr)){
1285
fprintf_plus(stderr, "Failed to get flags for interface "
1286
"\"%s\"\n", interface);
1291
return (bool)(ifr.ifr_flags & IFF_UP);
1295
* This function determines if a network interface is running
1297
__attribute__((nonnull, warn_unused_result))
1298
bool interface_is_running(const char *interface){
1300
if(not get_flags(interface, &ifr)){
1302
fprintf_plus(stderr, "Failed to get flags for interface "
1303
"\"%s\"\n", interface);
1308
return (bool)(ifr.ifr_flags & IFF_RUNNING);
1311
__attribute__((nonnull, pure, warn_unused_result))
1312
int notdotentries(const struct dirent *direntry){
1313
/* Skip "." and ".." */
1314
if(direntry->d_name[0] == '.'
1315
and (direntry->d_name[1] == '\0'
1316
or (direntry->d_name[1] == '.'
1317
and direntry->d_name[2] == '\0'))){
1323
/* Is this directory entry a runnable program? */
1324
__attribute__((nonnull, warn_unused_result))
1325
int runnable_hook(const struct dirent *direntry){
1330
if((direntry->d_name)[0] == '\0'){
1335
sret = strspn(direntry->d_name, "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
1336
"abcdefghijklmnopqrstuvwxyz"
1339
if((direntry->d_name)[sret] != '\0'){
1340
/* Contains non-allowed characters */
1342
fprintf_plus(stderr, "Ignoring hook \"%s\" with bad name\n",
1348
char *fullname = NULL;
1349
ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);
1351
perror_plus("asprintf");
1355
ret = stat(fullname, &st);
1358
perror_plus("Could not stat hook");
1363
if(not (S_ISREG(st.st_mode))){
1364
/* Not a regular file */
1366
fprintf_plus(stderr, "Ignoring hook \"%s\" - not a file\n",
1371
if(not (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))){
1372
/* Not executable */
1374
fprintf_plus(stderr, "Ignoring hook \"%s\" - not executable\n",
1380
fprintf_plus(stderr, "Hook \"%s\" is acceptable\n",
1386
__attribute__((nonnull, warn_unused_result))
1387
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,
1388
mandos_context *mc){
1390
struct timespec now;
1391
struct timespec waited_time;
1392
intmax_t block_time;
1395
if(mc->current_server == NULL){
1397
fprintf_plus(stderr, "Wait until first server is found."
1400
ret = avahi_simple_poll_iterate(s, -1);
1403
fprintf_plus(stderr, "Check current_server if we should run"
1406
/* the current time */
1407
ret = clock_gettime(CLOCK_MONOTONIC, &now);
1409
perror_plus("clock_gettime");
1412
/* Calculating in ms how long time between now and server
1413
who we visted longest time ago. Now - last seen. */
1414
waited_time.tv_sec = (now.tv_sec
1415
- mc->current_server->last_seen.tv_sec);
1416
waited_time.tv_nsec = (now.tv_nsec
1417
- mc->current_server->last_seen.tv_nsec);
1418
/* total time is 10s/10,000ms.
1419
Converting to s from ms by dividing by 1,000,
1420
and ns to ms by dividing by 1,000,000. */
1421
block_time = ((retry_interval
1422
- ((intmax_t)waited_time.tv_sec * 1000))
1423
- ((intmax_t)waited_time.tv_nsec / 1000000));
1426
fprintf_plus(stderr, "Blocking for %" PRIdMAX " ms\n",
1430
if(block_time <= 0){
1431
ret = start_mandos_communication(mc->current_server->ip,
1432
mc->current_server->port,
1433
mc->current_server->if_index,
1434
mc->current_server->af, mc);
1436
avahi_simple_poll_quit(s);
1439
ret = clock_gettime(CLOCK_MONOTONIC,
1440
&mc->current_server->last_seen);
1442
perror_plus("clock_gettime");
1445
mc->current_server = mc->current_server->next;
1446
block_time = 0; /* Call avahi to find new Mandos
1447
servers, but don't block */
1450
ret = avahi_simple_poll_iterate(s, (int)block_time);
1453
if(ret > 0 or errno != EINTR){
1454
return (ret != 1) ? ret : 0;
1460
/* Set effective uid to 0, return errno */
1461
__attribute__((warn_unused_result))
1462
error_t raise_privileges(void){
1463
error_t old_errno = errno;
1464
error_t ret_errno = 0;
1465
if(seteuid(0) == -1){
1467
perror_plus("seteuid");
1473
/* Set effective and real user ID to 0. Return errno. */
1474
__attribute__((warn_unused_result))
1475
error_t raise_privileges_permanently(void){
1476
error_t old_errno = errno;
1477
error_t ret_errno = raise_privileges();
1482
if(setuid(0) == -1){
1484
perror_plus("seteuid");
1490
/* Set effective user ID to unprivileged saved user ID */
1491
__attribute__((warn_unused_result))
1492
error_t lower_privileges(void){
1493
error_t old_errno = errno;
1494
error_t ret_errno = 0;
1495
if(seteuid(uid) == -1){
1497
perror_plus("seteuid");
1503
/* Lower privileges permanently */
1504
__attribute__((warn_unused_result))
1505
error_t lower_privileges_permanently(void){
1506
error_t old_errno = errno;
1507
error_t ret_errno = 0;
1508
if(setuid(uid) == -1){
1510
perror_plus("setuid");
1516
__attribute__((nonnull))
1517
void run_network_hooks(const char *mode, const char *interface,
1519
struct dirent **direntries;
1520
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1523
if(errno == ENOENT){
1525
fprintf_plus(stderr, "Network hook directory \"%s\" not"
1526
" found\n", hookdir);
1529
perror_plus("scandir");
1532
struct dirent *direntry;
1534
int devnull = open("/dev/null", O_RDONLY);
1535
for(int i = 0; i < numhooks; i++){
1536
direntry = direntries[i];
1537
char *fullname = NULL;
1538
ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);
1540
perror_plus("asprintf");
1544
fprintf_plus(stderr, "Running network hook \"%s\"\n",
1547
pid_t hook_pid = fork();
1550
/* Raise privileges */
1551
if(raise_privileges_permanently() != 0){
1552
perror_plus("Failed to raise privileges");
1559
perror_plus("setgid");
1562
/* Reset supplementary groups */
1564
ret = setgroups(0, NULL);
1566
perror_plus("setgroups");
1569
ret = dup2(devnull, STDIN_FILENO);
1571
perror_plus("dup2(devnull, STDIN_FILENO)");
1574
ret = close(devnull);
1576
perror_plus("close");
1579
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
1581
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
1584
ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);
1586
perror_plus("setenv");
1589
ret = setenv("DEVICE", interface, 1);
1591
perror_plus("setenv");
1594
ret = setenv("VERBOSITY", debug ? "1" : "0", 1);
1596
perror_plus("setenv");
1599
ret = setenv("MODE", mode, 1);
1601
perror_plus("setenv");
1605
ret = asprintf(&delaystring, "%f", (double)delay);
1607
perror_plus("asprintf");
1610
ret = setenv("DELAY", delaystring, 1);
1613
perror_plus("setenv");
1617
if(connect_to != NULL){
1618
ret = setenv("CONNECT", connect_to, 1);
1620
perror_plus("setenv");
1624
if(execl(fullname, direntry->d_name, mode, NULL) == -1){
1625
perror_plus("execl");
1626
_exit(EXIT_FAILURE);
1630
if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){
1631
perror_plus("waitpid");
1635
if(WIFEXITED(status)){
1636
if(WEXITSTATUS(status) != 0){
1637
fprintf_plus(stderr, "Warning: network hook \"%s\" exited"
1638
" with status %d\n", direntry->d_name,
1639
WEXITSTATUS(status));
1643
} else if(WIFSIGNALED(status)){
1644
fprintf_plus(stderr, "Warning: network hook \"%s\" died by"
1645
" signal %d\n", direntry->d_name,
1650
fprintf_plus(stderr, "Warning: network hook \"%s\""
1651
" crashed\n", direntry->d_name);
1658
fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",
1666
__attribute__((nonnull, warn_unused_result))
1667
error_t bring_up_interface(const char *const interface,
1669
error_t old_errno = errno;
1671
struct ifreq network;
1672
unsigned int if_index = if_nametoindex(interface);
1674
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1684
if(not interface_is_up(interface)){
1685
error_t ret_errno = 0, ioctl_errno = 0;
1686
if(not get_flags(interface, &network)){
1688
fprintf_plus(stderr, "Failed to get flags for interface "
1689
"\"%s\"\n", interface);
1693
network.ifr_flags |= IFF_UP; /* set flag */
1695
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1698
perror_plus("socket");
1704
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1706
perror_plus("close");
1713
fprintf_plus(stderr, "Bringing up interface \"%s\"\n",
1717
/* Raise privileges */
1718
ret_errno = raise_privileges();
1720
perror_plus("Failed to raise privileges");
1725
bool restore_loglevel = false;
1727
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1728
messages about the network interface to mess up the prompt */
1729
ret_linux = klogctl(8, NULL, 5);
1730
if(ret_linux == -1){
1731
perror_plus("klogctl");
1733
restore_loglevel = true;
1736
#endif /* __linux__ */
1737
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1738
ioctl_errno = errno;
1740
if(restore_loglevel){
1741
ret_linux = klogctl(7, NULL, 0);
1742
if(ret_linux == -1){
1743
perror_plus("klogctl");
1746
#endif /* __linux__ */
1748
/* If raise_privileges() succeeded above */
1750
/* Lower privileges */
1751
ret_errno = lower_privileges();
1754
perror_plus("Failed to lower privileges");
1758
/* Close the socket */
1759
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1761
perror_plus("close");
1764
if(ret_setflags == -1){
1765
errno = ioctl_errno;
1766
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1771
fprintf_plus(stderr, "Interface \"%s\" is already up; good\n",
1775
/* Sleep checking until interface is running.
1776
Check every 0.25s, up to total time of delay */
1777
for(int i=0; i < delay * 4; i++){
1778
if(interface_is_running(interface)){
1781
struct timespec sleeptime = { .tv_nsec = 250000000 };
1782
ret = nanosleep(&sleeptime, NULL);
1783
if(ret == -1 and errno != EINTR){
1784
perror_plus("nanosleep");
1792
__attribute__((nonnull, warn_unused_result))
1793
error_t take_down_interface(const char *const interface){
1794
error_t old_errno = errno;
1795
struct ifreq network;
1796
unsigned int if_index = if_nametoindex(interface);
1798
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1802
if(interface_is_up(interface)){
1803
error_t ret_errno = 0, ioctl_errno = 0;
1804
if(not get_flags(interface, &network) and debug){
1806
fprintf_plus(stderr, "Failed to get flags for interface "
1807
"\"%s\"\n", interface);
1811
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1813
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1816
perror_plus("socket");
1822
fprintf_plus(stderr, "Taking down interface \"%s\"\n",
1826
/* Raise privileges */
1827
ret_errno = raise_privileges();
1829
perror_plus("Failed to raise privileges");
1832
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1833
ioctl_errno = errno;
1835
/* If raise_privileges() succeeded above */
1837
/* Lower privileges */
1838
ret_errno = lower_privileges();
1841
perror_plus("Failed to lower privileges");
1845
/* Close the socket */
1846
int ret = (int)TEMP_FAILURE_RETRY(close(sd));
1848
perror_plus("close");
1851
if(ret_setflags == -1){
1852
errno = ioctl_errno;
1853
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
1858
fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",
824
1866
int main(int argc, char *argv[]){
1867
mandos_context mc = { .server = NULL, .dh_bits = 1024,
1868
.priority = "SECURE256:!CTYPE-X.509:"
1869
"+CTYPE-OPENPGP", .current_server = NULL,
1870
.interfaces = NULL, .interfaces_size = 0 };
825
1871
AvahiSServiceBrowser *sb = NULL;
828
1874
intmax_t tmpmax;
830
1876
int exitcode = EXIT_SUCCESS;
831
const char *interface = "eth0";
832
struct ifreq network;
836
char *connect_to = NULL;
837
char tempdir[] = "/tmp/mandosXXXXXX";
838
bool tempdir_created = false;
1877
char *interfaces_to_take_down = NULL;
1878
size_t interfaces_to_take_down_size = 0;
1879
char run_tempdir[] = "/run/tmp/mandosXXXXXX";
1880
char old_tempdir[] = "/tmp/mandosXXXXXX";
1881
char *tempdir = NULL;
839
1882
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
840
1883
const char *seckey = PATHDIR "/" SECKEY;
841
1884
const char *pubkey = PATHDIR "/" PUBKEY;
1885
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" };
846
1887
bool gnutls_initialized = false;
847
1888
bool gpgme_initialized = false;
1890
double retry_interval = 10; /* 10s between trying a server and
1891
retrying the same server again */
1893
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
1894
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
1899
/* Lower any group privileges we might have, just to be safe */
1903
perror_plus("setgid");
1906
/* Lower user privileges (temporarily) */
1910
perror_plus("seteuid");
851
1918
struct argp_option options[] = {
915
2004
mc.priority = arg;
917
2006
case 131: /* --delay */
918
ret = sscanf(arg, "%lf%n", &delay, &numchars);
919
if(ret < 1 or arg[numchars] != '\0'){
920
fprintf(stderr, "Bad delay\n");
2008
delay = strtof(arg, &tmp);
2009
if(errno != 0 or tmp == arg or *tmp != '\0'){
2010
argp_error(state, "Bad delay");
2012
case 132: /* --retry */
2014
retry_interval = strtod(arg, &tmp);
2015
if(errno != 0 or tmp == arg or *tmp != '\0'
2016
or (retry_interval * 1000) > INT_MAX
2017
or retry_interval < 0){
2018
argp_error(state, "Bad retry interval");
2021
case 133: /* --network-hook-dir */
2025
* These reproduce what we would get without ARGP_NO_HELP
2027
case '?': /* --help */
2028
argp_state_help(state, state->out_stream,
2029
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
2030
& ~(unsigned int)ARGP_HELP_EXIT_OK);
2031
case -3: /* --usage */
2032
argp_state_help(state, state->out_stream,
2033
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
2034
case 'V': /* --version */
2035
fprintf_plus(state->out_stream, "%s\n", argp_program_version);
2036
exit(argp_err_exit_status);
929
2039
return ARGP_ERR_UNKNOWN;
934
2044
struct argp argp = { .options = options, .parser = parse_opt,
936
2046
.doc = "Mandos client -- Get and decrypt"
937
2047
" passwords from a Mandos server" };
938
ret = argp_parse(&argp, argc, argv, 0, 0, NULL);
939
if(ret == ARGP_ERR_UNKNOWN){
940
fprintf(stderr, "Unknown error while parsing arguments\n");
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);
2048
ret = argp_parse(&argp, argc, argv,
2049
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
2056
perror_plus("argp_parse");
2057
exitcode = EX_OSERR;
2060
exitcode = EX_USAGE;
2066
/* Work around Debian bug #633582:
2067
<http://bugs.debian.org/633582> */
2069
/* Re-raise privileges */
2070
ret_errno = raise_privileges();
2073
perror_plus("Failed to raise privileges");
2077
if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){
2078
int seckey_fd = open(seckey, O_RDONLY);
2079
if(seckey_fd == -1){
2080
perror_plus("open");
2082
ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));
2084
perror_plus("fstat");
2086
if(S_ISREG(st.st_mode)
2087
and st.st_uid == 0 and st.st_gid == 0){
2088
ret = fchown(seckey_fd, uid, gid);
2090
perror_plus("fchown");
2094
TEMP_FAILURE_RETRY(close(seckey_fd));
2098
if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){
2099
int pubkey_fd = open(pubkey, O_RDONLY);
2100
if(pubkey_fd == -1){
2101
perror_plus("open");
2103
ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));
2105
perror_plus("fstat");
2107
if(S_ISREG(st.st_mode)
2108
and st.st_uid == 0 and st.st_gid == 0){
2109
ret = fchown(pubkey_fd, uid, gid);
2111
perror_plus("fchown");
2115
TEMP_FAILURE_RETRY(close(pubkey_fd));
2119
/* Lower privileges */
2120
ret_errno = lower_privileges();
2123
perror_plus("Failed to lower privileges");
2128
/* Remove invalid interface names (except "none") */
2130
char *interface = NULL;
2131
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2133
if(strcmp(interface, "none") != 0
2134
and if_nametoindex(interface) == 0){
2135
if(interface[0] != '\0'){
2136
fprintf_plus(stderr, "Not using nonexisting interface"
2137
" \"%s\"\n", interface);
2139
argz_delete(&mc.interfaces, &mc.interfaces_size, interface);
2145
/* Run network hooks */
2147
if(mc.interfaces != NULL){
2148
interfaces_hooks = malloc(mc.interfaces_size);
2149
if(interfaces_hooks == NULL){
2150
perror_plus("malloc");
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){
2153
memcpy(interfaces_hooks, mc.interfaces, mc.interfaces_size);
2154
argz_stringify(interfaces_hooks, mc.interfaces_size, (int)',');
2156
run_network_hooks("start", interfaces_hooks != NULL ?
2157
interfaces_hooks : "", delay);
2161
avahi_set_log_function(empty_log);
2164
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
2165
from the signal handler */
2166
/* Initialize the pseudo-RNG for Avahi */
2167
srand((unsigned int) time(NULL));
2168
simple_poll = avahi_simple_poll_new();
2169
if(simple_poll == NULL){
2170
fprintf_plus(stderr,
2171
"Avahi: Failed to create simple poll object.\n");
2172
exitcode = EX_UNAVAILABLE;
2176
sigemptyset(&sigterm_action.sa_mask);
2177
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
2179
perror_plus("sigaddset");
2180
exitcode = EX_OSERR;
2183
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
2185
perror_plus("sigaddset");
2186
exitcode = EX_OSERR;
2189
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
2191
perror_plus("sigaddset");
2192
exitcode = EX_OSERR;
2195
/* Need to check if the handler is SIG_IGN before handling:
2196
| [[info:libc:Initial Signal Actions]] |
2197
| [[info:libc:Basic Signal Handling]] |
2199
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
2201
perror_plus("sigaction");
2204
if(old_sigterm_action.sa_handler != SIG_IGN){
2205
ret = sigaction(SIGINT, &sigterm_action, NULL);
2207
perror_plus("sigaction");
2208
exitcode = EX_OSERR;
2212
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
2214
perror_plus("sigaction");
2217
if(old_sigterm_action.sa_handler != SIG_IGN){
2218
ret = sigaction(SIGHUP, &sigterm_action, NULL);
2220
perror_plus("sigaction");
2221
exitcode = EX_OSERR;
2225
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
2227
perror_plus("sigaction");
2230
if(old_sigterm_action.sa_handler != SIG_IGN){
2231
ret = sigaction(SIGTERM, &sigterm_action, NULL);
2233
perror_plus("sigaction");
2234
exitcode = EX_OSERR;
2239
/* If no interfaces were specified, make a list */
2240
if(mc.interfaces == NULL){
2241
struct dirent **direntries;
2242
/* Look for any good interfaces */
2243
ret = scandir(sys_class_net, &direntries, good_interface,
2246
/* Add all found interfaces to interfaces list */
2247
for(int i = 0; i < ret; ++i){
2248
ret_errno = argz_add(&mc.interfaces, &mc.interfaces_size,
2249
direntries[i]->d_name);
2252
perror_plus("argz_add");
2256
fprintf_plus(stderr, "Will use interface \"%s\"\n",
2257
direntries[i]->d_name);
2263
fprintf_plus(stderr, "Could not find a network interface\n");
2264
exitcode = EXIT_FAILURE;
2269
/* Bring up interfaces which are down, and remove any "none"s */
2271
char *interface = NULL;
2272
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2274
/* If interface name is "none", stop bringing up interfaces.
2275
Also remove all instances of "none" from the list */
2276
if(strcmp(interface, "none") == 0){
2277
argz_delete(&mc.interfaces, &mc.interfaces_size,
2280
while((interface = argz_next(mc.interfaces,
2281
mc.interfaces_size, interface))){
2282
if(strcmp(interface, "none") == 0){
2283
argz_delete(&mc.interfaces, &mc.interfaces_size,
1005
struct timespec sleeptime = { .tv_nsec = 250000000 };
1006
ret = nanosleep(&sleeptime, NULL);
1007
if(ret == -1 and errno != EINTR){
1008
perror("nanosleep");
2290
bool interface_was_up = interface_is_up(interface);
2291
errno = bring_up_interface(interface, delay);
2292
if(not interface_was_up){
2294
perror_plus("Failed to bring up interface");
2296
errno = argz_add(&interfaces_to_take_down,
2297
&interfaces_to_take_down_size,
2300
perror_plus("argz_add");
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;
2305
if(debug and (interfaces_to_take_down == NULL)){
2306
fprintf_plus(stderr, "No interfaces were brought up\n");
2310
/* If we only got one interface, explicitly use only that one */
2311
if(argz_count(mc.interfaces, mc.interfaces_size) == 1){
2313
fprintf_plus(stderr, "Using only interface \"%s\"\n",
2316
if_index = (AvahiIfIndex)if_nametoindex(mc.interfaces);
2323
ret = init_gnutls_global(pubkey, seckey, &mc);
2325
fprintf_plus(stderr, "init_gnutls_global failed\n");
2326
exitcode = EX_UNAVAILABLE;
1043
2329
gnutls_initialized = true;
1046
if(mkdtemp(tempdir) == NULL){
1050
tempdir_created = true;
1052
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
1053
fprintf(stderr, "init_gpgme failed\n");
1054
exitcode = EXIT_FAILURE;
2336
/* Try /run/tmp before /tmp */
2337
tempdir = mkdtemp(run_tempdir);
2338
if(tempdir == NULL and errno == ENOENT){
2340
fprintf_plus(stderr, "Tempdir %s did not work, trying %s\n",
2341
run_tempdir, old_tempdir);
2343
tempdir = mkdtemp(old_tempdir);
2345
if(tempdir == NULL){
2346
perror_plus("mkdtemp");
2354
if(not init_gpgme(pubkey, seckey, tempdir, &mc)){
2355
fprintf_plus(stderr, "init_gpgme failed\n");
2356
exitcode = EX_UNAVAILABLE;
1057
2359
gpgme_initialized = true;
1060
if_index = (AvahiIfIndex) if_nametoindex(interface);
1062
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1063
exitcode = EXIT_FAILURE;