56
56
#include <sys/stat.h> /* open(), S_ISREG */
57
57
#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
80
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() */
134
137
bool debug = false;
135
138
static const char mandos_protocol_version[] = "1";
136
const char *argp_program_version = "mandos-client " VERSION;
137
const char *argp_program_bug_address = "<mandos@recompile.se>";
139
const char * argp_program_version = "mandos-client " VERSION;
140
const char * argp_program_bug_address = "<mandos@recompile.se>";
138
141
static const char sys_class_net[] = "/sys/class/net";
139
142
char *connect_to = NULL;
140
143
const char *hookdir = HOOKDIR;
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);
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);
740
#pragma GCC diagnostic push
741
#pragma GCC diagnostic ignored "-Wstrict-aliasing"
743
if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */
744
(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower */
746
#pragma GCC diagnostic pop
754
((struct sockaddr_in6 *)&to)->sin6_port = htons(port);
755
if(IN6_IS_ADDR_LINKLOCAL
756
(&((struct sockaddr_in6 *)&to)->sin6_addr)){
748
757
if(if_index == AVAHI_IF_UNSPEC){
749
758
fprintf_plus(stderr, "An IPv6 link-local address is"
750
759
" incomplete without a network interface\n");
754
763
/* Set the network interface number as scope */
755
to.in6.sin6_scope_id = (uint32_t)if_index;
764
((struct sockaddr_in6 *)&to)->sin6_scope_id = (uint32_t)if_index;
758
to.in.sin_port = htons(port);
767
((struct sockaddr_in *)&to)->sin_port = htons(port);
779
788
char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?
780
789
INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";
782
790
if(af == AF_INET6){
783
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,
786
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,
790
perror_plus("inet_ntop");
792
if(strcmp(addrstr, ip) != 0){
793
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);
803
815
if(af == AF_INET6){
804
ret = connect(tcp_sd, &to.in6, sizeof(to));
816
ret = connect(tcp_sd, (struct sockaddr *)&to,
817
sizeof(struct sockaddr_in6));
806
ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */
819
ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */
820
sizeof(struct sockaddr_in));
809
if ((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){
823
if((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){
811
825
perror_plus("connect");
1236
1253
* corresponds to an acceptable network device.
1237
1254
* (This function is passed to scandir(3) as a filter function.)
1256
__attribute__((nonnull, warn_unused_result))
1239
1257
int good_interface(const struct dirent *if_entry){
1240
1258
if(if_entry->d_name[0] == '.'){
1260
1278
* This function determines if a network interface is up.
1280
__attribute__((nonnull, warn_unused_result))
1262
1281
bool interface_is_up(const char *interface){
1263
1282
struct ifreq ifr;
1264
1283
if(not get_flags(interface, &ifr)){
1276
1295
* This function determines if a network interface is running
1297
__attribute__((nonnull, warn_unused_result))
1278
1298
bool interface_is_running(const char *interface){
1279
1299
struct ifreq ifr;
1280
1300
if(not get_flags(interface, &ifr)){
1288
1308
return (bool)(ifr.ifr_flags & IFF_RUNNING);
1311
__attribute__((nonnull, pure, warn_unused_result))
1291
1312
int notdotentries(const struct dirent *direntry){
1292
1313
/* Skip "." and ".." */
1293
1314
if(direntry->d_name[0] == '.'
1371
1394
if(mc->current_server == NULL){
1373
1396
fprintf_plus(stderr, "Wait until first server is found."
1374
1397
" No timeout!\n");
1376
1399
ret = avahi_simple_poll_iterate(s, -1);
1379
1402
fprintf_plus(stderr, "Check current_server if we should run"
1380
1403
" it, or wait\n");
1426
1449
ret = avahi_simple_poll_iterate(s, (int)block_time);
1429
if (ret > 0 or errno != EINTR){
1452
if(ret > 0 or errno != EINTR){
1430
1453
return (ret != 1) ? ret : 0;
1436
1459
/* Set effective uid to 0, return errno */
1460
__attribute__((warn_unused_result))
1437
1461
error_t raise_privileges(void){
1438
1462
error_t old_errno = errno;
1439
1463
error_t ret_errno = 0;
1448
1472
/* Set effective and real user ID to 0. Return errno. */
1473
__attribute__((warn_unused_result))
1449
1474
error_t raise_privileges_permanently(void){
1450
1475
error_t old_errno = errno;
1451
1476
error_t ret_errno = raise_privileges();
1485
1512
return ret_errno;
1488
bool run_network_hooks(const char *mode, const char *interface,
1515
__attribute__((nonnull))
1516
void run_network_hooks(const char *mode, const char *interface,
1489
1517
const float delay){
1490
1518
struct dirent **direntries;
1491
struct dirent *direntry;
1493
1519
int numhooks = scandir(hookdir, &direntries, runnable_hook,
1495
1521
if(numhooks == -1){
1519
1547
if(hook_pid == 0){
1521
1549
/* Raise privileges */
1522
raise_privileges_permanently();
1550
if(raise_privileges_permanently() != 0){
1551
perror_plus("Failed to raise privileges");
1523
1554
/* Set group */
1525
1556
ret = setgid(0);
1527
1558
perror_plus("setgid");
1529
1561
/* Reset supplementary groups */
1531
1563
ret = setgroups(0, NULL);
1533
1565
perror_plus("setgroups");
1535
dup2(devnull, STDIN_FILENO);
1537
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)");
1538
1583
ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);
1540
1585
perror_plus("setenv");
1616
1661
close(devnull);
1665
__attribute__((nonnull, warn_unused_result))
1621
1666
error_t bring_up_interface(const char *const interface,
1622
1667
const float delay){
1624
1668
error_t old_errno = errno;
1625
error_t ret_errno = 0;
1626
int ret, ret_setflags;
1627
1670
struct ifreq network;
1628
1671
unsigned int if_index = if_nametoindex(interface);
1629
1672
if(if_index == 0){
1640
1683
if(not interface_is_up(interface)){
1641
if(not get_flags(interface, &network) and debug){
1684
error_t ret_errno = 0, ioctl_errno = 0;
1685
if(not get_flags(interface, &network)){
1642
1686
ret_errno = errno;
1643
1687
fprintf_plus(stderr, "Failed to get flags for interface "
1644
1688
"\"%s\"\n", interface);
1645
1690
return ret_errno;
1647
network.ifr_flags |= IFF_UP;
1692
network.ifr_flags |= IFF_UP; /* set flag */
1649
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1694
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1651
1696
ret_errno = errno;
1652
1697
perror_plus("socket");
1653
1698
errno = old_errno;
1654
1699
return ret_errno;
1703
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1705
perror_plus("close");
1659
1707
errno = old_errno;
1668
/* Raise priviliges */
1716
/* Raise privileges */
1717
ret_errno = raise_privileges();
1718
bool restore_loglevel = false;
1720
perror_plus("Failed to raise privileges");
1671
1722
#ifdef __linux__
1672
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1673
messages about the network interface to mess up the prompt */
1674
int ret_linux = klogctl(8, NULL, 5);
1675
bool restore_loglevel = true;
1676
if(ret_linux == -1){
1677
restore_loglevel = false;
1678
perror_plus("klogctl");
1725
/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO
1726
messages about the network interface to mess up the prompt */
1727
ret_linux = klogctl(8, NULL, 5);
1728
if(ret_linux == -1){
1729
perror_plus("klogctl");
1731
restore_loglevel = true;
1680
1734
#endif /* __linux__ */
1681
ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1735
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1736
ioctl_errno = errno;
1683
1737
#ifdef __linux__
1684
1738
if(restore_loglevel){
1685
1739
ret_linux = klogctl(7, NULL, 0);
1790
__attribute__((nonnull, warn_unused_result))
1729
1791
error_t take_down_interface(const char *const interface){
1731
1792
error_t old_errno = errno;
1732
error_t ret_errno = 0;
1733
int ret, ret_setflags;
1734
1793
struct ifreq network;
1735
1794
unsigned int if_index = if_nametoindex(interface);
1736
1795
if(if_index == 0){
1741
1800
if(interface_is_up(interface)){
1801
error_t ret_errno = 0, ioctl_errno = 0;
1742
1802
if(not get_flags(interface, &network) and debug){
1743
1803
ret_errno = errno;
1744
1804
fprintf_plus(stderr, "Failed to get flags for interface "
1745
1805
"\"%s\"\n", interface);
1746
1807
return ret_errno;
1748
1809
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1750
sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1811
int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1752
1813
ret_errno = errno;
1753
1814
perror_plus("socket");
1754
1815
errno = old_errno;
1763
/* Raise priviliges */
1766
ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1769
/* Lower privileges */
1824
/* Raise privileges */
1825
ret_errno = raise_privileges();
1827
perror_plus("Failed to raise privileges");
1829
int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);
1830
ioctl_errno = errno;
1832
/* If raise_privileges() succeeded above */
1834
/* Lower privileges */
1835
ret_errno = lower_privileges();
1838
perror_plus("Failed to lower privileges");
1772
1842
/* Close the socket */
1773
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1843
int ret = (int)TEMP_FAILURE_RETRY(close(sd));
1775
1845
perror_plus("close");
1778
1848
if(ret_setflags == -1){
1849
errno = ioctl_errno;
1780
1850
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
1781
1851
errno = old_errno;
1784
1854
} else if(debug){
1785
1855
fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",
1793
1863
int main(int argc, char *argv[]){
1794
1864
mandos_context mc = { .server = NULL, .dh_bits = 1024,
1795
1865
.priority = "SECURE256:!CTYPE-X.509:"
1796
"+CTYPE-OPENPGP", .current_server = NULL,
1866
"+CTYPE-OPENPGP", .current_server = NULL,
1797
1867
.interfaces = NULL, .interfaces_size = 0 };
1798
1868
AvahiSServiceBrowser *sb = NULL;
1799
1869
error_t ret_errno;
1803
1873
int exitcode = EXIT_SUCCESS;
1804
1874
char *interfaces_to_take_down = NULL;
1805
1875
size_t interfaces_to_take_down_size = 0;
1806
char tempdir[] = "/tmp/mandosXXXXXX";
1807
bool tempdir_created = false;
1876
char run_tempdir[] = "/run/tmp/mandosXXXXXX";
1877
char old_tempdir[] = "/tmp/mandosXXXXXX";
1878
char *tempdir = NULL;
1808
1879
AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
1809
1880
const char *seckey = PATHDIR "/" SECKEY;
1810
1881
const char *pubkey = PATHDIR "/" PUBKEY;
1811
1882
char *interfaces_hooks = NULL;
1812
size_t interfaces_hooks_size = 0;
1814
1884
bool gnutls_initialized = false;
1815
1885
bool gpgme_initialized = false;
1993
2063
/* Work around Debian bug #633582:
1994
2064
<http://bugs.debian.org/633582> */
1996
/* Re-raise priviliges */
1997
if(raise_privileges() == 0){
2066
/* Re-raise privileges */
2067
ret_errno = raise_privileges();
2070
perror_plus("Failed to raise privileges");
1998
2072
struct stat st;
2000
2074
if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){
2072
2150
memcpy(interfaces_hooks, mc.interfaces, mc.interfaces_size);
2073
interfaces_hooks_size = mc.interfaces_size;
2074
argz_stringify(interfaces_hooks, interfaces_hooks_size,
2077
if(not run_network_hooks("start", interfaces_hooks != NULL ?
2078
interfaces_hooks : "", delay)){
2151
argz_stringify(interfaces_hooks, mc.interfaces_size, (int)',');
2153
run_network_hooks("start", interfaces_hooks != NULL ?
2154
interfaces_hooks : "", delay);
2212
2287
bool interface_was_up = interface_is_up(interface);
2213
ret = bring_up_interface(interface, delay);
2288
errno = bring_up_interface(interface, delay);
2214
2289
if(not interface_was_up){
2217
2291
perror_plus("Failed to bring up interface");
2219
ret_errno = argz_add(&interfaces_to_take_down,
2220
&interfaces_to_take_down_size,
2293
errno = argz_add(&interfaces_to_take_down,
2294
&interfaces_to_take_down_size,
2297
perror_plus("argz_add");
2256
if(mkdtemp(tempdir) == NULL){
2333
/* Try /run/tmp before /tmp */
2334
tempdir = mkdtemp(run_tempdir);
2335
if(tempdir == NULL and errno == ENOENT){
2337
fprintf_plus(stderr, "Tempdir %s did not work, trying %s\n",
2338
run_tempdir, old_tempdir);
2340
tempdir = mkdtemp(old_tempdir);
2342
if(tempdir == NULL){
2257
2343
perror_plus("mkdtemp");
2260
tempdir_created = true;
2449
/* Re-raise priviliges */
2534
/* Re-raise privileges */
2453
/* Run network hooks */
2454
run_network_hooks("stop", interfaces_hooks != NULL ?
2455
interfaces_hooks : "", delay);
2457
/* Take down the network interfaces which were brought up */
2459
char *interface = NULL;
2460
while((interface=argz_next(interfaces_to_take_down,
2461
interfaces_to_take_down_size,
2463
ret_errno = take_down_interface(interface);
2466
perror_plus("Failed to take down interface");
2469
if(debug and (interfaces_to_take_down == NULL)){
2470
fprintf_plus(stderr, "No interfaces needed to be taken"
2475
lower_privileges_permanently();
2536
ret_errno = raise_privileges();
2538
perror_plus("Failed to raise privileges");
2541
/* Run network hooks */
2542
run_network_hooks("stop", interfaces_hooks != NULL ?
2543
interfaces_hooks : "", delay);
2545
/* Take down the network interfaces which were brought up */
2547
char *interface = NULL;
2548
while((interface=argz_next(interfaces_to_take_down,
2549
interfaces_to_take_down_size,
2551
ret_errno = take_down_interface(interface);
2554
perror_plus("Failed to take down interface");
2557
if(debug and (interfaces_to_take_down == NULL)){
2558
fprintf_plus(stderr, "No interfaces needed to be taken"
2563
ret_errno = lower_privileges_permanently();
2565
perror_plus("Failed to lower privileges permanently");
2478
2569
free(interfaces_to_take_down);
2479
2570
free(interfaces_hooks);
2481
2572
/* Removes the GPGME temp directory and all files inside */
2482
if(tempdir_created){
2573
if(tempdir != NULL){
2483
2574
struct dirent **direntries = NULL;
2484
2575
struct dirent *direntry = NULL;
2485
2576
int numentries = scandir(tempdir, &direntries, notdotentries,
2487
if (numentries > 0){
2488
2579
for(int i = 0; i < numentries; i++){
2489
2580
direntry = direntries[i];
2490
2581
char *fullname = NULL;