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(),
59
58
#include <fcntl.h> /* open() */
60
59
#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() */
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() */
67
65
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
68
66
SIOCSIFFLAGS, if_indextoname(),
69
67
if_nametoindex(), IF_NAMESIZE */
70
#include <netinet/in.h> /* IN6_IS_ADDR_LINKLOCAL,
71
INET_ADDRSTRLEN, INET6_ADDRSTRLEN
68
#include <netinet/in.h>
73
69
#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 */
70
getuid(), getgid(), setuid(),
72
#include <arpa/inet.h> /* inet_pton(), htons */
73
#include <iso646.h> /* not, and, or */
78
74
#include <argp.h> /* struct argp_option, error_t, struct
79
75
argp_state, struct argp,
80
76
argp_parse(), ARGP_KEY_ARG,
81
77
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
79
#include <sys/klog.h> /* klogctl() */
97
#endif /* __linux__ */
100
83
/* All Avahi types, constants and functions
129
112
#define PATHDIR "/conf/conf.d/mandos"
130
113
#define SECKEY "seckey.txt"
131
114
#define PUBKEY "pubkey.txt"
132
#define HOOKDIR "/lib/mandos/network-hooks.d"
134
116
bool debug = false;
135
117
static const char mandos_protocol_version[] = "1";
136
118
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;
144
/* Doubly linked list that need to be circularly linked when used */
145
typedef struct server{
148
AvahiIfIndex if_index;
150
struct timespec last_seen;
119
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
155
121
/* Used for passing in values through the Avahi callback functions */
123
AvahiSimplePoll *simple_poll;
157
124
AvahiServer *server;
158
125
gnutls_certificate_credentials_t cred;
159
126
unsigned int dh_bits;
160
127
gnutls_dh_params_t dh_params;
161
128
const char *priority;
163
server *current_server;
165
size_t interfaces_size;
166
130
} mandos_context;
168
/* global so signal handler can reach it*/
169
AvahiSimplePoll *simple_poll;
171
sig_atomic_t quit_now = 0;
172
int signal_received = 0;
174
/* Function to use when printing errors */
175
void perror_plus(const char *print_text){
177
fprintf(stderr, "Mandos plugin %s: ",
178
program_invocation_short_name);
183
__attribute__((format (gnu_printf, 2, 3)))
184
int fprintf_plus(FILE *stream, const char *format, ...){
186
va_start (ap, format);
188
TEMP_FAILURE_RETRY(fprintf(stream, "Mandos plugin %s: ",
189
program_invocation_short_name));
190
return (int)TEMP_FAILURE_RETRY(vfprintf(stream, format, ap));
194
* Make additional room in "buffer" for at least BUFFER_SIZE more
195
* 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,
196
135
* "buffer_length" is how much is already used.
198
size_t incbuffer(char **buffer, size_t buffer_length,
199
size_t buffer_capacity){
137
size_t adjustbuffer(char **buffer, size_t buffer_length,
138
size_t buffer_capacity){
200
139
if(buffer_length + BUFFER_SIZE > buffer_capacity){
201
char *new_buf = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
203
int old_errno = errno;
140
*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
210
144
buffer_capacity += BUFFER_SIZE;
212
146
return buffer_capacity;
215
/* Add server to set of servers to retry periodically */
216
bool add_server(const char *ip, in_port_t port, AvahiIfIndex if_index,
217
int af, server **current_server){
219
server *new_server = malloc(sizeof(server));
220
if(new_server == NULL){
221
perror_plus("malloc");
224
*new_server = (server){ .ip = strdup(ip),
226
.if_index = if_index,
228
if(new_server->ip == NULL){
229
perror_plus("strdup");
232
/* Special case of first server */
233
if(*current_server == NULL){
234
new_server->next = new_server;
235
new_server->prev = new_server;
236
*current_server = new_server;
237
/* Place the new server last in the list */
239
new_server->next = *current_server;
240
new_server->prev = (*current_server)->prev;
241
new_server->prev->next = new_server;
242
(*current_server)->prev = new_server;
244
ret = clock_gettime(CLOCK_MONOTONIC, &(*current_server)->last_seen);
246
perror_plus("clock_gettime");
253
150
* Initialize GPGME.
255
static bool init_gpgme(const char *seckey, const char *pubkey,
256
const char *tempdir, mandos_context *mc){
152
static bool init_gpgme(mandos_context *mc, const char *seckey,
153
const char *pubkey, const char *tempdir){
257
155
gpgme_error_t rc;
258
156
gpgme_engine_info_t engine_info;
261
160
* Helper function to insert pub and seckey to the engine keyring.
263
162
bool import_key(const char *filename){
266
164
gpgme_data_t pgp_data;
268
166
fd = (int)TEMP_FAILURE_RETRY(open(filename, O_RDONLY));
274
172
rc = gpgme_data_new_from_fd(&pgp_data, fd);
275
173
if(rc != GPG_ERR_NO_ERROR){
276
fprintf_plus(stderr, "bad gpgme_data_new_from_fd: %s: %s\n",
277
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));
281
179
rc = gpgme_op_import(mc->ctx, pgp_data);
282
180
if(rc != GPG_ERR_NO_ERROR){
283
fprintf_plus(stderr, "bad gpgme_op_import: %s: %s\n",
284
gpgme_strsource(rc), gpgme_strerror(rc));
181
fprintf(stderr, "bad gpgme_op_import: %s: %s\n",
182
gpgme_strsource(rc), gpgme_strerror(rc));
288
186
ret = (int)TEMP_FAILURE_RETRY(close(fd));
290
perror_plus("close");
292
190
gpgme_data_release(pgp_data);
297
fprintf_plus(stderr, "Initializing GPGME\n");
195
fprintf(stderr, "Initialize gpgme\n");
301
199
gpgme_check_version(NULL);
302
200
rc = gpgme_engine_check_version(GPGME_PROTOCOL_OpenPGP);
303
201
if(rc != GPG_ERR_NO_ERROR){
304
fprintf_plus(stderr, "bad gpgme_engine_check_version: %s: %s\n",
305
gpgme_strsource(rc), gpgme_strerror(rc));
202
fprintf(stderr, "bad gpgme_engine_check_version: %s: %s\n",
203
gpgme_strsource(rc), gpgme_strerror(rc));
309
/* Set GPGME home directory for the OpenPGP engine only */
207
/* Set GPGME home directory for the OpenPGP engine only */
310
208
rc = gpgme_get_engine_info(&engine_info);
311
209
if(rc != GPG_ERR_NO_ERROR){
312
fprintf_plus(stderr, "bad gpgme_get_engine_info: %s: %s\n",
313
gpgme_strsource(rc), gpgme_strerror(rc));
210
fprintf(stderr, "bad gpgme_get_engine_info: %s: %s\n",
211
gpgme_strsource(rc), gpgme_strerror(rc));
316
214
while(engine_info != NULL){
626
507
__attribute__((unused)) const char *txt){}
628
509
/* Called when a Mandos server is found */
629
static int start_mandos_communication(const char *ip, in_port_t port,
510
static int start_mandos_communication(const char *ip, uint16_t port,
630
511
AvahiIfIndex if_index,
631
int af, mandos_context *mc){
632
int ret, tcp_sd = -1;
635
struct sockaddr_in in;
636
struct sockaddr_in6 in6;
515
union { struct sockaddr in; struct sockaddr_in6 in6; } to;
638
516
char *buffer = NULL;
639
char *decrypted_buffer = NULL;
517
char *decrypted_buffer;
640
518
size_t buffer_length = 0;
641
519
size_t buffer_capacity = 0;
520
ssize_t decrypted_buffer_size;
523
char interface[IF_NAMESIZE];
644
524
gnutls_session_t session;
645
int pf; /* Protocol family */
662
fprintf_plus(stderr, "Bad address family: %d\n", af);
667
/* If the interface is specified and we have a list of interfaces */
668
if(if_index != AVAHI_IF_UNSPEC and mc->interfaces != NULL){
669
/* Check if the interface is one of the interfaces we are using */
672
char *interface = NULL;
673
while((interface=argz_next(mc->interfaces, mc->interfaces_size,
675
if(if_nametoindex(interface) == (unsigned int)if_index){
682
/* This interface does not match any in the list, so we don't
683
connect to the server */
685
char interface[IF_NAMESIZE];
686
if(if_indextoname((unsigned int)if_index, interface) == NULL){
687
perror_plus("if_indextoname");
689
fprintf_plus(stderr, "Skipping server on non-used interface"
691
if_indextoname((unsigned int)if_index,
699
ret = init_gnutls_session(&session, mc);
526
ret = init_gnutls_session(mc, &session);
705
fprintf_plus(stderr, "Setting up a TCP connection to %s, port %"
706
PRIuMAX "\n", ip, (uintmax_t)port);
532
fprintf(stderr, "Setting up a tcp connection to %s, port %" PRIu16
709
tcp_sd = socket(pf, SOCK_STREAM, 0);
536
tcp_sd = socket(PF_INET6, SOCK_STREAM, 0);
712
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);
722
550
memset(&to, 0, sizeof(to));
724
to.in6.sin6_family = (sa_family_t)af;
725
ret = inet_pton(af, ip, &to.in6.sin6_addr);
727
to.in.sin_family = (sa_family_t)af;
728
ret = inet_pton(af, ip, &to.in.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);
732
perror_plus("inet_pton");
738
fprintf_plus(stderr, "Bad address: %s\n", ip);
743
to.in6.sin6_port = htons(port);
745
#pragma GCC diagnostic push
746
#pragma GCC diagnostic ignored "-Wstrict-aliasing"
748
if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */
749
(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower */
751
#pragma GCC diagnostic pop
753
if(if_index == AVAHI_IF_UNSPEC){
754
fprintf_plus(stderr, "An IPv6 link-local address is"
755
" incomplete without a network interface\n");
759
/* Set the network interface number as scope */
760
to.in6.sin6_scope_id = (uint32_t)if_index;
763
to.in.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;
772
if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){
773
char interface[IF_NAMESIZE];
774
if(if_indextoname((unsigned int)if_index, interface) == NULL){
775
perror_plus("if_indextoname");
777
fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIuMAX
778
"\n", ip, interface, (uintmax_t)port);
781
fprintf_plus(stderr, "Connection to: %s, port %" PRIuMAX "\n",
782
ip, (uintmax_t)port);
784
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
785
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
788
pcret = inet_ntop(af, &(to.in6.sin6_addr), addrstr,
791
pcret = inet_ntop(af, &(to.in.sin_addr), addrstr,
795
perror_plus("inet_ntop");
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){
797
577
if(strcmp(addrstr, ip) != 0){
798
fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);
578
fprintf(stderr, "Canonical address form: %s\n", addrstr);
809
ret = connect(tcp_sd, &to.in6, sizeof(to));
811
ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */
583
ret = connect(tcp_sd, &to.in, sizeof(to));
814
if ((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){
816
perror_plus("connect");
827
589
const char *out = mandos_protocol_version;
1148
815
case AVAHI_BROWSER_ALL_FOR_NOW:
1149
816
case AVAHI_BROWSER_CACHE_EXHAUSTED:
1151
fprintf_plus(stderr, "No Mandos server found, still"
818
fprintf(stderr, "No Mandos server found, still searching...\n");
1158
/* Signal handler that stops main loop after SIGTERM */
1159
static void handle_sigterm(int sig){
1164
signal_received = sig;
1165
int old_errno = errno;
1166
/* set main loop to exit */
1167
if(simple_poll != NULL){
1168
avahi_simple_poll_quit(simple_poll);
1173
bool get_flags(const char *ifname, struct ifreq *ifr){
1177
int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1180
perror_plus("socket");
1184
strcpy(ifr->ifr_name, ifname);
1185
ret = ioctl(s, SIOCGIFFLAGS, ifr);
1189
perror_plus("ioctl SIOCGIFFLAGS");
1197
bool good_flags(const char *ifname, const struct ifreq *ifr){
1199
/* Reject the loopback device */
1200
if(ifr->ifr_flags & IFF_LOOPBACK){
1202
fprintf_plus(stderr, "Rejecting loopback interface \"%s\"\n",
1207
/* Accept point-to-point devices only if connect_to is specified */
1208
if(connect_to != NULL and (ifr->ifr_flags & IFF_POINTOPOINT)){
1210
fprintf_plus(stderr, "Accepting point-to-point interface"
1211
" \"%s\"\n", ifname);
1215
/* Otherwise, reject non-broadcast-capable devices */
1216
if(not (ifr->ifr_flags & IFF_BROADCAST)){
1218
fprintf_plus(stderr, "Rejecting non-broadcast interface"
1219
" \"%s\"\n", ifname);
1223
/* Reject non-ARP interfaces (including dummy interfaces) */
1224
if(ifr->ifr_flags & IFF_NOARP){
1226
fprintf_plus(stderr, "Rejecting non-ARP interface \"%s\"\n",
1232
/* Accept this device */
1234
fprintf_plus(stderr, "Interface \"%s\" is good\n", ifname);
1240
* This function determines if a directory entry in /sys/class/net
1241
* corresponds to an acceptable network device.
1242
* (This function is passed to scandir(3) as a filter function.)
1244
int good_interface(const struct dirent *if_entry){
1245
if(if_entry->d_name[0] == '.'){
1250
if(not get_flags(if_entry->d_name, &ifr)){
1252
fprintf_plus(stderr, "Failed to get flags for interface "
1253
"\"%s\"\n", if_entry->d_name);
1258
if(not good_flags(if_entry->d_name, &ifr)){
1265
* This function determines if a network interface is up.
1267
bool interface_is_up(const char *interface){
1269
if(not get_flags(interface, &ifr)){
1271
fprintf_plus(stderr, "Failed to get flags for interface "
1272
"\"%s\"\n", interface);
1277
return (bool)(ifr.ifr_flags & IFF_UP);
1281
* This function determines if a network interface is running
1283
bool interface_is_running(const char *interface){
1285
if(not get_flags(interface, &ifr)){
1287
fprintf_plus(stderr, "Failed to get flags for interface "
1288
"\"%s\"\n", interface);
1293
return (bool)(ifr.ifr_flags & IFF_RUNNING);
1296
int notdotentries(const struct dirent *direntry){
1297
/* Skip "." and ".." */
1298
if(direntry->d_name[0] == '.'
1299
and (direntry->d_name[1] == '\0'
1300
or (direntry->d_name[1] == '.'
1301
and direntry->d_name[2] == '\0'))){
1307
/* Is this directory entry a runnable program? */
1308
int runnable_hook(const struct dirent *direntry){
1313
if((direntry->d_name)[0] == '\0'){
1318
sret = strspn(direntry->d_name, "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
1319
"abcdefghijklmnopqrstuvwxyz"
1322
if((direntry->d_name)[sret] != '\0'){
1323
/* Contains non-allowed characters */
1325
fprintf_plus(stderr, "Ignoring hook \"%s\" with bad name\n",
1331
char *fullname = NULL;
1332
ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);
1334
perror_plus("asprintf");
1338
ret = stat(fullname, &st);
1341
perror_plus("Could not stat hook");
1345
if(not (S_ISREG(st.st_mode))){
1346
/* Not a regular file */
1348
fprintf_plus(stderr, "Ignoring hook \"%s\" - not a file\n",
1353
if(not (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))){
1354
/* Not executable */
1356
fprintf_plus(stderr, "Ignoring hook \"%s\" - not executable\n",
1362
fprintf_plus(stderr, "Hook \"%s\" is acceptable\n",
1368
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,
1369
mandos_context *mc){
1371
struct timespec now;
1372
struct timespec waited_time;
1373
intmax_t block_time;
1376
if(mc->current_server == NULL){
1378
fprintf_plus(stderr, "Wait until first server is found."
1381
ret = avahi_simple_poll_iterate(s, -1);
1384
fprintf_plus(stderr, "Check current_server if we should run"
1387
/* the current time */
1388
ret = clock_gettime(CLOCK_MONOTONIC, &now);
1390
perror_plus("clock_gettime");
1393
/* Calculating in ms how long time between now and server
1394
who we visted longest time ago. Now - last seen. */
1395
waited_time.tv_sec = (now.tv_sec
1396
- mc->current_server->last_seen.tv_sec);
1397
waited_time.tv_nsec = (now.tv_nsec
1398
- mc->current_server->last_seen.tv_nsec);
1399
/* total time is 10s/10,000ms.
1400
Converting to s from ms by dividing by 1,000,
1401
and ns to ms by dividing by 1,000,000. */
1402
block_time = ((retry_interval
1403
- ((intmax_t)waited_time.tv_sec * 1000))
1404
- ((intmax_t)waited_time.tv_nsec / 1000000));
1407
fprintf_plus(stderr, "Blocking for %" PRIdMAX " ms\n",
1411
if(block_time <= 0){
1412
ret = start_mandos_communication(mc->current_server->ip,
1413
mc->current_server->port,
1414
mc->current_server->if_index,
1415
mc->current_server->af, mc);
1417
avahi_simple_poll_quit(s);
1420
ret = clock_gettime(CLOCK_MONOTONIC,
1421
&mc->current_server->last_seen);
1423
perror_plus("clock_gettime");
1426
mc->current_server = mc->current_server->next;
1427
block_time = 0; /* Call avahi to find new Mandos
1428
servers, but don't block */
1431
ret = avahi_simple_poll_iterate(s, (int)block_time);
1434
if (ret > 0 or errno != EINTR){
1435
return (ret != 1) ? ret : 0;
1441
/* Set effective uid to 0, return errno */
1442
error_t raise_privileges(void){
1443
error_t old_errno = errno;
1444
error_t ret_errno = 0;
1445
if(seteuid(0) == -1){
1447
perror_plus("seteuid");
1453
/* Set effective and real user ID to 0. Return errno. */
1454
error_t raise_privileges_permanently(void){
1455
error_t old_errno = errno;
1456
error_t ret_errno = raise_privileges();
1461
if(setuid(0) == -1){
1463
perror_plus("seteuid");
1469
/* Set effective user ID to unprivileged saved user ID */
1470
error_t lower_privileges(void){
1471
error_t old_errno = errno;
1472
error_t ret_errno = 0;
1473
if(seteuid(uid) == -1){
1475
perror_plus("seteuid");
1481
/* Lower privileges permanently */
1482
error_t lower_privileges_permanently(void){
1483
error_t old_errno = errno;
1484
error_t ret_errno = 0;
1485
if(setuid(uid) == -1){
1487
perror_plus("setuid");
1493
bool run_network_hooks(const char *mode, const char *interface,
1495
struct dirent **direntries;
1496
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1499
if(errno == ENOENT){
1501
fprintf_plus(stderr, "Network hook directory \"%s\" not"
1502
" found\n", hookdir);
1505
perror_plus("scandir");
1508
struct dirent *direntry;
1510
int devnull = open("/dev/null", O_RDONLY);
1511
for(int i = 0; i < numhooks; i++){
1512
direntry = direntries[i];
1513
char *fullname = NULL;
1514
ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);
1516
perror_plus("asprintf");
1520
fprintf_plus(stderr, "Running network hook \"%s\"\n",
1523
pid_t hook_pid = fork();
1526
/* Raise privileges */
1527
raise_privileges_permanently();
1532
perror_plus("setgid");
1534
/* Reset supplementary groups */
1536
ret = setgroups(0, NULL);
1538
perror_plus("setgroups");
1540
dup2(devnull, STDIN_FILENO);
1542
dup2(STDERR_FILENO, STDOUT_FILENO);
1543
ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);
1545
perror_plus("setenv");
1548
ret = setenv("DEVICE", interface, 1);
1550
perror_plus("setenv");
1553
ret = setenv("VERBOSITY", debug ? "1" : "0", 1);
1555
perror_plus("setenv");
1558
ret = setenv("MODE", mode, 1);
1560
perror_plus("setenv");
1564
ret = asprintf(&delaystring, "%f", delay);
1566
perror_plus("asprintf");
1569
ret = setenv("DELAY", delaystring, 1);
1572
perror_plus("setenv");
1576
if(connect_to != NULL){
1577
ret = setenv("CONNECT", connect_to, 1);
1579
perror_plus("setenv");
1583
if(execl(fullname, direntry->d_name, mode, NULL) == -1){
1584
perror_plus("execl");
1585
_exit(EXIT_FAILURE);
1589
if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){
1590
perror_plus("waitpid");
1594
if(WIFEXITED(status)){
1595
if(WEXITSTATUS(status) != 0){
1596
fprintf_plus(stderr, "Warning: network hook \"%s\" exited"
1597
" with status %d\n", direntry->d_name,
1598
WEXITSTATUS(status));
1602
} else if(WIFSIGNALED(status)){
1603
fprintf_plus(stderr, "Warning: network hook \"%s\" died by"
1604
" signal %d\n", direntry->d_name,
1609
fprintf_plus(stderr, "Warning: network hook \"%s\""
1610
" crashed\n", direntry->d_name);
1617
fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",
1626
error_t bring_up_interface(const char *const interface,
1629
error_t old_errno = errno;
1630
error_t ret_errno = 0;
1631
int ret, ret_setflags;
1632
struct ifreq network;
1633
unsigned int if_index = if_nametoindex(interface);
1635
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1645
if(not interface_is_up(interface)){
1646
if(not get_flags(interface, &network) and debug){
1648
fprintf_plus(stderr, "Failed to get flags for interface "
1649
"\"%s\"\n", interface);
1652
network.ifr_flags |= IFF_UP;
1654
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1657
perror_plus("socket");
1669
fprintf_plus(stderr, "Bringing up interface \"%s\"\n",
1673
/* Raise priviliges */
1677
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1678
messages about the network interface to mess up the prompt */
1679
int ret_linux = klogctl(8, NULL, 5);
1680
bool restore_loglevel = true;
1681
if(ret_linux == -1){
1682
restore_loglevel = false;
1683
perror_plus("klogctl");
1685
#endif /* __linux__ */
1686
ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1689
if(restore_loglevel){
1690
ret_linux = klogctl(7, NULL, 0);
1691
if(ret_linux == -1){
1692
perror_plus("klogctl");
1695
#endif /* __linux__ */
1697
/* Lower privileges */
1700
/* Close the socket */
1701
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1703
perror_plus("close");
1706
if(ret_setflags == -1){
1708
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1713
fprintf_plus(stderr, "Interface \"%s\" is already up; good\n",
1717
/* Sleep checking until interface is running.
1718
Check every 0.25s, up to total time of delay */
1719
for(int i=0; i < delay * 4; i++){
1720
if(interface_is_running(interface)){
1723
struct timespec sleeptime = { .tv_nsec = 250000000 };
1724
ret = nanosleep(&sleeptime, NULL);
1725
if(ret == -1 and errno != EINTR){
1726
perror_plus("nanosleep");
1734
error_t take_down_interface(const char *const interface){
1735
error_t old_errno = errno;
1736
struct ifreq network;
1737
unsigned int if_index = if_nametoindex(interface);
1739
fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);
1743
if(interface_is_up(interface)){
1744
error_t ret_errno = 0;
1745
if(not get_flags(interface, &network) and debug){
1747
fprintf_plus(stderr, "Failed to get flags for interface "
1748
"\"%s\"\n", interface);
1751
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1753
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1756
perror_plus("socket");
1762
fprintf_plus(stderr, "Taking down interface \"%s\"\n",
1766
/* Raise priviliges */
1769
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1772
/* Lower privileges */
1775
/* Close the socket */
1776
int ret = (int)TEMP_FAILURE_RETRY(close(sd));
1778
perror_plus("close");
1781
if(ret_setflags == -1){
1783
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
1788
fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",
1796
824
int main(int argc, char *argv[]){
1797
mandos_context mc = { .server = NULL, .dh_bits = 1024,
1798
.priority = "SECURE256:!CTYPE-X.509:"
1799
"+CTYPE-OPENPGP", .current_server = NULL,
1800
.interfaces = NULL, .interfaces_size = 0 };
1801
825
AvahiSServiceBrowser *sb = NULL;
1804
828
intmax_t tmpmax;
1806
830
int exitcode = EXIT_SUCCESS;
1807
char *interfaces_to_take_down = NULL;
1808
size_t interfaces_to_take_down_size = 0;
831
const char *interface = "eth0";
832
struct ifreq network;
836
char *connect_to = NULL;
1809
837
char tempdir[] = "/tmp/mandosXXXXXX";
1810
838
bool tempdir_created = false;
1811
839
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
1812
840
const char *seckey = PATHDIR "/" SECKEY;
1813
841
const char *pubkey = PATHDIR "/" PUBKEY;
1814
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" };
1816
846
bool gnutls_initialized = false;
1817
847
bool gpgme_initialized = false;
1819
double retry_interval = 10; /* 10s between trying a server and
1820
retrying the same server again */
1822
struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
1823
struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
1828
/* Lower any group privileges we might have, just to be safe */
1832
perror_plus("setgid");
1835
/* Lower user privileges (temporarily) */
1839
perror_plus("seteuid");
1847
851
struct argp_option options[] = {
1933
915
mc.priority = arg;
1935
917
case 131: /* --delay */
1937
delay = strtof(arg, &tmp);
1938
if(errno != 0 or tmp == arg or *tmp != '\0'){
1939
argp_error(state, "Bad delay");
1941
case 132: /* --retry */
1943
retry_interval = strtod(arg, &tmp);
1944
if(errno != 0 or tmp == arg or *tmp != '\0'
1945
or (retry_interval * 1000) > INT_MAX
1946
or retry_interval < 0){
1947
argp_error(state, "Bad retry interval");
1950
case 133: /* --network-hook-dir */
1954
* These reproduce what we would get without ARGP_NO_HELP
1956
case '?': /* --help */
1957
argp_state_help(state, state->out_stream,
1958
(ARGP_HELP_STD_HELP | ARGP_HELP_EXIT_ERR)
1959
& ~(unsigned int)ARGP_HELP_EXIT_OK);
1960
case -3: /* --usage */
1961
argp_state_help(state, state->out_stream,
1962
ARGP_HELP_USAGE | ARGP_HELP_EXIT_ERR);
1963
case 'V': /* --version */
1964
fprintf_plus(state->out_stream, "%s\n", argp_program_version);
1965
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");
1968
929
return ARGP_ERR_UNKNOWN;
1973
934
struct argp argp = { .options = options, .parser = parse_opt,
1975
936
.doc = "Mandos client -- Get and decrypt"
1976
937
" passwords from a Mandos server" };
1977
ret = argp_parse(&argp, argc, argv,
1978
ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);
1985
perror_plus("argp_parse");
1986
exitcode = EX_OSERR;
1989
exitcode = EX_USAGE;
1995
/* Work around Debian bug #633582:
1996
<http://bugs.debian.org/633582> */
1998
/* Re-raise priviliges */
1999
if(raise_privileges() == 0){
2002
if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){
2003
int seckey_fd = open(seckey, O_RDONLY);
2004
if(seckey_fd == -1){
2005
perror_plus("open");
2007
ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));
2009
perror_plus("fstat");
2011
if(S_ISREG(st.st_mode)
2012
and st.st_uid == 0 and st.st_gid == 0){
2013
ret = fchown(seckey_fd, uid, gid);
2015
perror_plus("fchown");
2019
TEMP_FAILURE_RETRY(close(seckey_fd));
2023
if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){
2024
int pubkey_fd = open(pubkey, O_RDONLY);
2025
if(pubkey_fd == -1){
2026
perror_plus("open");
2028
ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));
2030
perror_plus("fstat");
2032
if(S_ISREG(st.st_mode)
2033
and st.st_uid == 0 and st.st_gid == 0){
2034
ret = fchown(pubkey_fd, uid, gid);
2036
perror_plus("fchown");
2040
TEMP_FAILURE_RETRY(close(pubkey_fd));
2044
/* Lower privileges */
2049
/* Remove invalid interface names (except "none") */
2051
char *interface = NULL;
2052
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2054
if(strcmp(interface, "none") != 0
2055
and if_nametoindex(interface) == 0){
2056
if(interface[0] != '\0'){
2057
fprintf_plus(stderr, "Not using nonexisting interface"
2058
" \"%s\"\n", interface);
2060
argz_delete(&mc.interfaces, &mc.interfaces_size, interface);
2066
/* Run network hooks */
2068
if(mc.interfaces != NULL){
2069
interfaces_hooks = malloc(mc.interfaces_size);
2070
if(interfaces_hooks == NULL){
2071
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);
2074
memcpy(interfaces_hooks, mc.interfaces, mc.interfaces_size);
2075
argz_stringify(interfaces_hooks, mc.interfaces_size, (int)',');
2077
if(not run_network_hooks("start", interfaces_hooks != NULL ?
2078
interfaces_hooks : "", delay)){
2084
avahi_set_log_function(empty_log);
2087
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
2088
from the signal handler */
2089
/* Initialize the pseudo-RNG for Avahi */
2090
srand((unsigned int) time(NULL));
2091
simple_poll = avahi_simple_poll_new();
2092
if(simple_poll == NULL){
2093
fprintf_plus(stderr,
2094
"Avahi: Failed to create simple poll object.\n");
2095
exitcode = EX_UNAVAILABLE;
2099
sigemptyset(&sigterm_action.sa_mask);
2100
ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
2102
perror_plus("sigaddset");
2103
exitcode = EX_OSERR;
2106
ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
2108
perror_plus("sigaddset");
2109
exitcode = EX_OSERR;
2112
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
2114
perror_plus("sigaddset");
2115
exitcode = EX_OSERR;
2118
/* Need to check if the handler is SIG_IGN before handling:
2119
| [[info:libc:Initial Signal Actions]] |
2120
| [[info:libc:Basic Signal Handling]] |
2122
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
2124
perror_plus("sigaction");
2127
if(old_sigterm_action.sa_handler != SIG_IGN){
2128
ret = sigaction(SIGINT, &sigterm_action, NULL);
2130
perror_plus("sigaction");
2131
exitcode = EX_OSERR;
2135
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
2137
perror_plus("sigaction");
2140
if(old_sigterm_action.sa_handler != SIG_IGN){
2141
ret = sigaction(SIGHUP, &sigterm_action, NULL);
2143
perror_plus("sigaction");
2144
exitcode = EX_OSERR;
2148
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
2150
perror_plus("sigaction");
2153
if(old_sigterm_action.sa_handler != SIG_IGN){
2154
ret = sigaction(SIGTERM, &sigterm_action, NULL);
2156
perror_plus("sigaction");
2157
exitcode = EX_OSERR;
2162
/* If no interfaces were specified, make a list */
2163
if(mc.interfaces == NULL){
2164
struct dirent **direntries;
2165
/* Look for any good interfaces */
2166
ret = scandir(sys_class_net, &direntries, good_interface,
2169
/* Add all found interfaces to interfaces list */
2170
for(int i = 0; i < ret; ++i){
2171
ret_errno = argz_add(&mc.interfaces, &mc.interfaces_size,
2172
direntries[i]->d_name);
2175
perror_plus("argz_add");
2179
fprintf_plus(stderr, "Will use interface \"%s\"\n",
2180
direntries[i]->d_name);
2186
fprintf_plus(stderr, "Could not find a network interface\n");
2187
exitcode = EXIT_FAILURE;
2192
/* Bring up interfaces which are down, and remove any "none"s */
2194
char *interface = NULL;
2195
while((interface = argz_next(mc.interfaces, mc.interfaces_size,
2197
/* If interface name is "none", stop bringing up interfaces.
2198
Also remove all instances of "none" from the list */
2199
if(strcmp(interface, "none") == 0){
2200
argz_delete(&mc.interfaces, &mc.interfaces_size,
2203
while((interface = argz_next(mc.interfaces,
2204
mc.interfaces_size, interface))){
2205
if(strcmp(interface, "none") == 0){
2206
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){
2213
bool interface_was_up = interface_is_up(interface);
2214
ret = bring_up_interface(interface, delay);
2215
if(not interface_was_up){
2218
perror_plus("Failed to bring up interface");
2220
ret_errno = argz_add(&interfaces_to_take_down,
2221
&interfaces_to_take_down_size,
2225
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");
2230
if(debug and (interfaces_to_take_down == NULL)){
2231
fprintf_plus(stderr, "No interfaces were brought up\n");
2235
/* If we only got one interface, explicitly use only that one */
2236
if(argz_count(mc.interfaces, mc.interfaces_size) == 1){
2238
fprintf_plus(stderr, "Using only interface \"%s\"\n",
2241
if_index = (AvahiIfIndex)if_nametoindex(mc.interfaces);
2248
ret = init_gnutls_global(pubkey, seckey, &mc);
2250
fprintf_plus(stderr, "init_gnutls_global failed\n");
2251
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;
2254
1043
gnutls_initialized = true;
2261
1046
if(mkdtemp(tempdir) == NULL){
2262
perror_plus("mkdtemp");
2265
1050
tempdir_created = true;
2271
if(not init_gpgme(pubkey, seckey, tempdir, &mc)){
2272
fprintf_plus(stderr, "init_gpgme failed\n");
2273
exitcode = EX_UNAVAILABLE;
1052
if(not init_gpgme(&mc, pubkey, seckey, tempdir)){
1053
fprintf(stderr, "init_gpgme failed\n");
1054
exitcode = EXIT_FAILURE;
2276
1057
gpgme_initialized = true;
1060
if_index = (AvahiIfIndex) if_nametoindex(interface);
1062
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1063
exitcode = EXIT_FAILURE;