9
9
* "browse_callback", and parts of "main".
11
11
* Everything else is
12
* Copyright © 2008-2012 Teddy Hogeborn
13
* Copyright © 2008-2012 Björn Påhlsson
12
* Copyright © 2008-2014 Teddy Hogeborn
13
* Copyright © 2008-2014 Björn Påhlsson
15
15
* This program is free software: you can redistribute it and/or
16
16
* modify it under the terms of the GNU General Public License as
56
56
#include <sys/stat.h> /* open(), S_ISREG */
57
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#include <sys/socket.h> /* socket(), struct sockaddr_in6,
58
inet_pton(), connect() */
58
inet_pton(), connect(),
59
60
#include <fcntl.h> /* open() */
60
61
#include <dirent.h> /* opendir(), struct dirent, readdir()
73
74
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
74
75
getuid(), getgid(), seteuid(),
75
76
setgid(), pause(), _exit() */
76
#include <arpa/inet.h> /* inet_pton(), htons, inet_ntop() */
77
#include <arpa/inet.h> /* inet_pton(), htons() */
77
78
#include <iso646.h> /* not, or, and */
78
79
#include <argp.h> /* struct argp_option, error_t, struct
79
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argp_state, struct argp,
91
92
argz_delete(), argz_append(),
92
93
argz_stringify(), argz_add(),
95
#include <netdb.h> /* getnameinfo(), NI_NUMERICHOST,
96
EAI_SYSTEM, gai_strerror() */
96
99
#include <sys/klog.h> /* klogctl() */
180
183
perror(print_text);
183
__attribute__((format (gnu_printf, 2, 3)))
186
__attribute__((format (gnu_printf, 2, 3), nonnull))
184
187
int fprintf_plus(FILE *stream, const char *format, ...){
186
189
va_start (ap, format);
188
191
TEMP_FAILURE_RETRY(fprintf(stream, "Mandos plugin %s: ",
189
192
program_invocation_short_name));
190
return TEMP_FAILURE_RETRY(vfprintf(stream, format, ap));
193
return (int)TEMP_FAILURE_RETRY(vfprintf(stream, format, ap));
195
198
* bytes. "buffer_capacity" is how much is currently allocated,
196
199
* "buffer_length" is how much is already used.
201
__attribute__((nonnull, warn_unused_result))
198
202
size_t incbuffer(char **buffer, size_t buffer_length,
199
203
size_t buffer_capacity){
200
204
if(buffer_length + BUFFER_SIZE > buffer_capacity){
201
*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
205
char *new_buf = realloc(*buffer, buffer_capacity + BUFFER_SIZE);
207
int old_errno = errno;
205
214
buffer_capacity += BUFFER_SIZE;
207
216
return buffer_capacity;
210
219
/* Add server to set of servers to retry periodically */
220
__attribute__((nonnull, warn_unused_result))
211
221
bool add_server(const char *ip, in_port_t port, AvahiIfIndex if_index,
212
222
int af, server **current_server){
224
234
perror_plus("strdup");
237
ret = clock_gettime(CLOCK_MONOTONIC, &(new_server->last_seen));
239
perror_plus("clock_gettime");
227
242
/* Special case of first server */
228
243
if(*current_server == NULL){
229
244
new_server->next = new_server;
230
245
new_server->prev = new_server;
231
246
*current_server = new_server;
232
/* Place the new server last in the list */
248
/* Place the new server last in the list */
234
249
new_server->next = *current_server;
235
250
new_server->prev = (*current_server)->prev;
236
251
new_server->prev->next = new_server;
237
252
(*current_server)->prev = new_server;
239
ret = clock_gettime(CLOCK_MONOTONIC, &(*current_server)->last_seen);
241
perror_plus("clock_gettime");
248
258
* Initialize GPGME.
250
static bool init_gpgme(const char *seckey, const char *pubkey,
251
const char *tempdir, mandos_context *mc){
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,
252
265
gpgme_error_t rc;
253
266
gpgme_engine_info_t engine_info;
256
269
* Helper function to insert pub and seckey to the engine keyring.
258
bool import_key(const char *filename){
271
bool import_key(const char * const filename){
261
274
gpgme_data_t pgp_data;
477
492
/* GnuTLS log function callback */
493
__attribute__((nonnull))
478
494
static void debuggnutls(__attribute__((unused)) int level,
479
495
const char* string){
480
496
fprintf_plus(stderr, "GnuTLS: %s", string);
499
__attribute__((nonnull, warn_unused_result))
483
500
static int init_gnutls_global(const char *pubkeyfilename,
484
501
const char *seckeyfilename,
485
502
mandos_context *mc){
621
639
__attribute__((unused)) const char *txt){}
623
641
/* Called when a Mandos server is found */
642
__attribute__((nonnull, warn_unused_result))
624
643
static int start_mandos_communication(const char *ip, in_port_t port,
625
644
AvahiIfIndex if_index,
626
645
int af, mandos_context *mc){
627
646
int ret, tcp_sd = -1;
630
struct sockaddr_in in;
631
struct sockaddr_in6 in6;
648
struct sockaddr_storage to;
633
649
char *buffer = NULL;
634
650
char *decrypted_buffer = NULL;
635
651
size_t buffer_length = 0;
717
733
memset(&to, 0, sizeof(to));
718
734
if(af == AF_INET6){
719
to.in6.sin6_family = (sa_family_t)af;
720
ret = inet_pton(af, 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);
721
737
} else { /* IPv4 */
722
to.in.sin_family = (sa_family_t)af;
723
ret = inet_pton(af, ip, &to.in.sin_addr);
738
((struct sockaddr_in *)&to)->sin_family = (sa_family_t)af;
739
ret = inet_pton(af, ip, &((struct sockaddr_in *)&to)->sin_addr);
737
753
if(af == AF_INET6){
738
to.in6.sin6_port = htons(port);
739
if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */
740
(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower and
754
((struct sockaddr_in6 *)&to)->sin6_port = htons(port);
755
if(IN6_IS_ADDR_LINKLOCAL
756
(&((struct sockaddr_in6 *)&to)->sin6_addr)){
742
757
if(if_index == AVAHI_IF_UNSPEC){
743
758
fprintf_plus(stderr, "An IPv6 link-local address is"
744
759
" incomplete without a network interface\n");
748
763
/* Set the network interface number as scope */
749
to.in6.sin6_scope_id = (uint32_t)if_index;
764
((struct sockaddr_in6 *)&to)->sin6_scope_id = (uint32_t)if_index;
752
to.in.sin_port = htons(port); /* Spurious warnings from
754
-Wunreachable-code */
767
((struct sockaddr_in *)&to)->sin_port = htons(port);
775
788
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
776
789
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
778
790
if(af == AF_INET6){
779
pcret = inet_ntop(af, &(to.in6.sin6_addr), addrstr,
791
ret = getnameinfo((struct sockaddr *)&to,
792
sizeof(struct sockaddr_in6),
793
addrstr, sizeof(addrstr), NULL, 0,
782
pcret = inet_ntop(af, &(to.in.sin_addr), addrstr,
796
ret = getnameinfo((struct sockaddr *)&to,
797
sizeof(struct sockaddr_in),
798
addrstr, sizeof(addrstr), NULL, 0,
786
perror_plus("inet_ntop");
788
if(strcmp(addrstr, ip) != 0){
789
fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);
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);
799
815
if(af == AF_INET6){
800
ret = connect(tcp_sd, &to.in6, sizeof(to));
816
ret = connect(tcp_sd, (struct sockaddr *)&to,
817
sizeof(struct sockaddr_in6));
802
ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */
819
ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */
820
sizeof(struct sockaddr_in));
805
if ((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){
823
if((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){
807
825
perror_plus("connect");
1232
1253
* corresponds to an acceptable network device.
1233
1254
* (This function is passed to scandir(3) as a filter function.)
1256
__attribute__((nonnull, warn_unused_result))
1235
1257
int good_interface(const struct dirent *if_entry){
1236
1258
if(if_entry->d_name[0] == '.'){
1256
1278
* This function determines if a network interface is up.
1280
__attribute__((nonnull, warn_unused_result))
1258
1281
bool interface_is_up(const char *interface){
1259
1282
struct ifreq ifr;
1260
1283
if(not get_flags(interface, &ifr)){
1272
1295
* This function determines if a network interface is running
1297
__attribute__((nonnull, warn_unused_result))
1274
1298
bool interface_is_running(const char *interface){
1275
1299
struct ifreq ifr;
1276
1300
if(not get_flags(interface, &ifr)){
1284
1308
return (bool)(ifr.ifr_flags & IFF_RUNNING);
1311
__attribute__((nonnull, pure, warn_unused_result))
1287
1312
int notdotentries(const struct dirent *direntry){
1288
1313
/* Skip "." and ".." */
1289
1314
if(direntry->d_name[0] == '.'
1367
1394
if(mc->current_server == NULL){
1369
1396
fprintf_plus(stderr, "Wait until first server is found."
1370
1397
" No timeout!\n");
1372
1399
ret = avahi_simple_poll_iterate(s, -1);
1375
1402
fprintf_plus(stderr, "Check current_server if we should run"
1376
1403
" it, or wait\n");
1422
1449
ret = avahi_simple_poll_iterate(s, (int)block_time);
1425
if (ret > 0 or errno != EINTR){
1452
if(ret > 0 or errno != EINTR){
1426
1453
return (ret != 1) ? ret : 0;
1432
1459
/* Set effective uid to 0, return errno */
1460
__attribute__((warn_unused_result))
1433
1461
error_t raise_privileges(void){
1434
1462
error_t old_errno = errno;
1435
1463
error_t ret_errno = 0;
1444
1472
/* Set effective and real user ID to 0. Return errno. */
1473
__attribute__((warn_unused_result))
1445
1474
error_t raise_privileges_permanently(void){
1446
1475
error_t old_errno = errno;
1447
1476
error_t ret_errno = raise_privileges();
1481
1512
return ret_errno;
1484
bool run_network_hooks(const char *mode, const char *interface,
1515
__attribute__((nonnull))
1516
void run_network_hooks(const char *mode, const char *interface,
1485
1517
const float delay){
1486
1518
struct dirent **direntries;
1487
struct dirent *direntry;
1489
1519
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1491
1521
if(numhooks == -1){
1515
1547
if(hook_pid == 0){
1517
1549
/* Raise privileges */
1518
raise_privileges_permanently();
1550
if(raise_privileges_permanently() != 0){
1551
perror_plus("Failed to raise privileges");
1519
1554
/* Set group */
1521
1556
ret = setgid(0);
1523
1558
perror_plus("setgid");
1525
1561
/* Reset supplementary groups */
1527
1563
ret = setgroups(0, NULL);
1529
1565
perror_plus("setgroups");
1531
dup2(devnull, STDIN_FILENO);
1533
dup2(STDERR_FILENO, STDOUT_FILENO);
1568
ret = dup2(devnull, STDIN_FILENO);
1570
perror_plus("dup2(devnull, STDIN_FILENO)");
1573
ret = close(devnull);
1575
perror_plus("close");
1578
ret = dup2(STDERR_FILENO, STDOUT_FILENO);
1580
perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");
1534
1583
ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);
1536
1585
perror_plus("setenv");
1612
1661
close(devnull);
1665
__attribute__((nonnull, warn_unused_result))
1617
1666
error_t bring_up_interface(const char *const interface,
1618
1667
const float delay){
1620
1668
error_t old_errno = errno;
1621
error_t ret_errno = 0;
1622
int ret, ret_setflags;
1623
1670
struct ifreq network;
1624
1671
unsigned int if_index = if_nametoindex(interface);
1625
1672
if(if_index == 0){
1636
1683
if(not interface_is_up(interface)){
1637
if(not get_flags(interface, &network) and debug){
1684
error_t ret_errno = 0, ioctl_errno = 0;
1685
if(not get_flags(interface, &network)){
1638
1686
ret_errno = errno;
1639
1687
fprintf_plus(stderr, "Failed to get flags for interface "
1640
1688
"\"%s\"\n", interface);
1641
1690
return ret_errno;
1643
network.ifr_flags |= IFF_UP;
1692
network.ifr_flags |= IFF_UP; /* set flag */
1645
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1694
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1647
1696
ret_errno = errno;
1648
1697
perror_plus("socket");
1649
1698
errno = old_errno;
1650
1699
return ret_errno;
1703
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1705
perror_plus("close");
1655
1707
errno = old_errno;
1664
/* Raise priviliges */
1716
/* Raise privileges */
1717
ret_errno = raise_privileges();
1719
perror_plus("Failed to raise privileges");
1667
1722
#ifdef __linux__
1668
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1669
messages about the network interface to mess up the prompt */
1670
int ret_linux = klogctl(8, NULL, 5);
1671
bool restore_loglevel = true;
1672
if(ret_linux == -1){
1673
restore_loglevel = false;
1674
perror_plus("klogctl");
1724
bool restore_loglevel = false;
1726
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1727
messages about the network interface to mess up the prompt */
1728
ret_linux = klogctl(8, NULL, 5);
1729
if(ret_linux == -1){
1730
perror_plus("klogctl");
1732
restore_loglevel = true;
1676
1735
#endif /* __linux__ */
1677
ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1736
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1737
ioctl_errno = errno;
1679
1738
#ifdef __linux__
1680
1739
if(restore_loglevel){
1681
1740
ret_linux = klogctl(7, NULL, 0);
1791
__attribute__((nonnull, warn_unused_result))
1725
1792
error_t take_down_interface(const char *const interface){
1727
1793
error_t old_errno = errno;
1728
error_t ret_errno = 0;
1729
int ret, ret_setflags;
1730
1794
struct ifreq network;
1731
1795
unsigned int if_index = if_nametoindex(interface);
1732
1796
if(if_index == 0){
1737
1801
if(interface_is_up(interface)){
1802
error_t ret_errno = 0, ioctl_errno = 0;
1738
1803
if(not get_flags(interface, &network) and debug){
1739
1804
ret_errno = errno;
1740
1805
fprintf_plus(stderr, "Failed to get flags for interface "
1741
1806
"\"%s\"\n", interface);
1742
1808
return ret_errno;
1744
1810
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1746
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1812
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1748
1814
ret_errno = errno;
1749
1815
perror_plus("socket");
1750
1816
errno = old_errno;
1759
/* Raise priviliges */
1762
ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1765
/* Lower privileges */
1825
/* Raise privileges */
1826
ret_errno = raise_privileges();
1828
perror_plus("Failed to raise privileges");
1831
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1832
ioctl_errno = errno;
1834
/* If raise_privileges() succeeded above */
1836
/* Lower privileges */
1837
ret_errno = lower_privileges();
1840
perror_plus("Failed to lower privileges");
1768
1844
/* Close the socket */
1769
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1845
int ret = (int)TEMP_FAILURE_RETRY(close(sd));
1771
1847
perror_plus("close");
1774
1850
if(ret_setflags == -1){
1851
errno = ioctl_errno;
1776
1852
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
1777
1853
errno = old_errno;
1780
1856
} else if(debug){
1781
1857
fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",
1789
1865
int main(int argc, char *argv[]){
1790
1866
mandos_context mc = { .server = NULL, .dh_bits = 1024,
1791
1867
.priority = "SECURE256:!CTYPE-X.509:"
1792
"+CTYPE-OPENPGP", .current_server = NULL,
1868
"+CTYPE-OPENPGP", .current_server = NULL,
1793
1869
.interfaces = NULL, .interfaces_size = 0 };
1794
1870
AvahiSServiceBrowser *sb = NULL;
1795
1871
error_t ret_errno;
1799
1875
int exitcode = EXIT_SUCCESS;
1800
1876
char *interfaces_to_take_down = NULL;
1801
1877
size_t interfaces_to_take_down_size = 0;
1802
char tempdir[] = "/tmp/mandosXXXXXX";
1803
bool tempdir_created = false;
1878
char run_tempdir[] = "/run/tmp/mandosXXXXXX";
1879
char old_tempdir[] = "/tmp/mandosXXXXXX";
1880
char *tempdir = NULL;
1804
1881
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
1805
1882
const char *seckey = PATHDIR "/" SECKEY;
1806
1883
const char *pubkey = PATHDIR "/" PUBKEY;
1807
1884
char *interfaces_hooks = NULL;
1808
size_t interfaces_hooks_size = 0;
1810
1886
bool gnutls_initialized = false;
1811
1887
bool gpgme_initialized = false;
1989
2065
/* Work around Debian bug #633582:
1990
2066
<http://bugs.debian.org/633582> */
1992
/* Re-raise priviliges */
1993
if(raise_privileges() == 0){
2068
/* Re-raise privileges */
2069
ret_errno = raise_privileges();
2072
perror_plus("Failed to raise privileges");
1994
2074
struct stat st;
1996
2076
if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){
2068
2152
memcpy(interfaces_hooks, mc.interfaces, mc.interfaces_size);
2069
interfaces_hooks_size = mc.interfaces_size;
2070
argz_stringify(interfaces_hooks, interfaces_hooks_size,
2073
if(not run_network_hooks("start", interfaces_hooks != NULL ?
2074
interfaces_hooks : "", delay)){
2153
argz_stringify(interfaces_hooks, mc.interfaces_size, (int)',');
2155
run_network_hooks("start", interfaces_hooks != NULL ?
2156
interfaces_hooks : "", delay);
2208
2289
bool interface_was_up = interface_is_up(interface);
2209
ret = bring_up_interface(interface, delay);
2290
errno = bring_up_interface(interface, delay);
2210
2291
if(not interface_was_up){
2213
2293
perror_plus("Failed to bring up interface");
2215
ret_errno = argz_add(&interfaces_to_take_down,
2216
&interfaces_to_take_down_size,
2295
errno = argz_add(&interfaces_to_take_down,
2296
&interfaces_to_take_down_size,
2299
perror_plus("argz_add");
2252
if(mkdtemp(tempdir) == NULL){
2335
/* Try /run/tmp before /tmp */
2336
tempdir = mkdtemp(run_tempdir);
2337
if(tempdir == NULL and errno == ENOENT){
2339
fprintf_plus(stderr, "Tempdir %s did not work, trying %s\n",
2340
run_tempdir, old_tempdir);
2342
tempdir = mkdtemp(old_tempdir);
2344
if(tempdir == NULL){
2253
2345
perror_plus("mkdtemp");
2256
tempdir_created = true;
2445
/* Re-raise priviliges */
2536
/* Re-raise privileges */
2449
/* Run network hooks */
2450
run_network_hooks("stop", interfaces_hooks != NULL ?
2451
interfaces_hooks : "", delay);
2453
/* Take down the network interfaces which were brought up */
2455
char *interface = NULL;
2456
while((interface=argz_next(interfaces_to_take_down,
2457
interfaces_to_take_down_size,
2459
ret_errno = take_down_interface(interface);
2462
perror_plus("Failed to take down interface");
2465
if(debug and (interfaces_to_take_down == NULL)){
2466
fprintf_plus(stderr, "No interfaces needed to be taken"
2471
lower_privileges_permanently();
2538
ret_errno = raise_privileges();
2540
perror_plus("Failed to raise privileges");
2543
/* Run network hooks */
2544
run_network_hooks("stop", interfaces_hooks != NULL ?
2545
interfaces_hooks : "", delay);
2547
/* Take down the network interfaces which were brought up */
2549
char *interface = NULL;
2550
while((interface=argz_next(interfaces_to_take_down,
2551
interfaces_to_take_down_size,
2553
ret_errno = take_down_interface(interface);
2556
perror_plus("Failed to take down interface");
2559
if(debug and (interfaces_to_take_down == NULL)){
2560
fprintf_plus(stderr, "No interfaces needed to be taken"
2566
ret_errno = lower_privileges_permanently();
2568
perror_plus("Failed to lower privileges permanently");
2474
2572
free(interfaces_to_take_down);
2475
2573
free(interfaces_hooks);
2477
2575
/* Removes the GPGME temp directory and all files inside */
2478
if(tempdir_created){
2576
if(tempdir != NULL){
2479
2577
struct dirent **direntries = NULL;
2480
2578
struct dirent *direntry = NULL;
2481
2579
int numentries = scandir(tempdir, &direntries, notdotentries,
2483
if (numentries > 0){
2484
2582
for(int i = 0; i < numentries; i++){
2485
2583
direntry = direntries[i];
2486
2584
char *fullname = NULL;