62
62
#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,
64
64
#include <assert.h> /* assert() */
65
#include <errno.h> /* perror(), errno */
65
#include <errno.h> /* perror(), errno,
66
program_invocation_short_name */
66
67
#include <time.h> /* nanosleep(), time(), sleep() */
67
68
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
68
69
SIOCSIFFLAGS, if_indextoname(),
73
74
#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
74
75
getuid(), getgid(), seteuid(),
75
76
setgid(), pause() */
76
#include <arpa/inet.h> /* inet_pton(), htons */
77
#include <arpa/inet.h> /* inet_pton(), htons, inet_ntop() */
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,
122
123
#define PATHDIR "/conf/conf.d/mandos"
123
124
#define SECKEY "seckey.txt"
124
125
#define PUBKEY "pubkey.txt"
126
#define HOOKDIR "/lib/mandos/network-hooks.d"
126
128
bool debug = false;
127
129
static const char mandos_protocol_version[] = "1";
128
130
const char *argp_program_version = "mandos-client " VERSION;
129
const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
131
const char *argp_program_bug_address = "<mandos@recompile.se>";
130
132
static const char sys_class_net[] = "/sys/class/net";
131
133
char *connect_to = NULL;
135
/* Doubly linked list that need to be circularly linked when used */
136
typedef struct server{
139
AvahiIfIndex if_index;
141
struct timespec last_seen;
133
146
/* Used for passing in values through the Avahi callback functions */
135
148
AvahiSimplePoll *simple_poll;
139
152
gnutls_dh_params_t dh_params;
140
153
const char *priority;
155
server *current_server;
142
156
} mandos_context;
144
158
/* global context so signal handler can reach it*/
145
159
mandos_context mc = { .simple_poll = NULL, .server = NULL,
146
160
.dh_bits = 1024, .priority = "SECURE256"
147
":!CTYPE-X.509:+CTYPE-OPENPGP" };
161
":!CTYPE-X.509:+CTYPE-OPENPGP",
162
.current_server = NULL };
149
164
sig_atomic_t quit_now = 0;
150
165
int signal_received = 0;
167
/* Function to use when printing errors */
168
void perror_plus(const char *print_text){
169
fprintf(stderr, "Mandos plugin %s: ",
170
program_invocation_short_name);
153
175
* Make additional room in "buffer" for at least BUFFER_SIZE more
154
176
* bytes. "buffer_capacity" is how much is currently allocated,
166
188
return buffer_capacity;
191
/* Add server to set of servers to retry periodically */
192
int add_server(const char *ip, uint16_t port,
193
AvahiIfIndex if_index,
196
server *new_server = malloc(sizeof(server));
197
if(new_server == NULL){
198
perror_plus("malloc");
201
*new_server = (server){ .ip = strdup(ip),
203
.if_index = if_index,
205
if(new_server->ip == NULL){
206
perror_plus("strdup");
209
/* Special case of first server */
210
if (mc.current_server == NULL){
211
new_server->next = new_server;
212
new_server->prev = new_server;
213
mc.current_server = new_server;
214
/* Place the new server last in the list */
216
new_server->next = mc.current_server;
217
new_server->prev = mc.current_server->prev;
218
new_server->prev->next = new_server;
219
mc.current_server->prev = new_server;
221
ret = clock_gettime(CLOCK_MONOTONIC, &mc.current_server->last_seen);
223
perror_plus("clock_gettime");
170
230
* Initialize GPGME.
425
485
/* OpenPGP credentials */
426
gnutls_certificate_allocate_credentials(&mc.cred);
486
ret = gnutls_certificate_allocate_credentials(&mc.cred);
427
487
if(ret != GNUTLS_E_SUCCESS){
428
fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning
488
fprintf(stderr, "GnuTLS memory error: %s\n",
432
489
safer_gnutls_strerror(ret));
433
490
gnutls_global_deinit();
1019
1080
signal_received = sig;
1020
1081
int old_errno = errno;
1082
/* set main loop to exit */
1021
1083
if(mc.simple_poll != NULL){
1022
1084
avahi_simple_poll_quit(mc.simple_poll);
1024
1086
errno = old_errno;
1089
bool get_flags(const char *ifname, struct ifreq *ifr){
1092
int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);
1094
perror_plus("socket");
1097
strcpy(ifr->ifr_name, ifname);
1098
ret = ioctl(s, SIOCGIFFLAGS, ifr);
1101
perror_plus("ioctl SIOCGIFFLAGS");
1108
bool good_flags(const char *ifname, const struct ifreq *ifr){
1110
/* Reject the loopback device */
1111
if(ifr->ifr_flags & IFF_LOOPBACK){
1113
fprintf(stderr, "Rejecting loopback interface \"%s\"\n",
1118
/* Accept point-to-point devices only if connect_to is specified */
1119
if(connect_to != NULL and (ifr->ifr_flags & IFF_POINTOPOINT)){
1121
fprintf(stderr, "Accepting point-to-point interface \"%s\"\n",
1126
/* Otherwise, reject non-broadcast-capable devices */
1127
if(not (ifr->ifr_flags & IFF_BROADCAST)){
1129
fprintf(stderr, "Rejecting non-broadcast interface \"%s\"\n",
1134
/* Reject non-ARP interfaces (including dummy interfaces) */
1135
if(ifr->ifr_flags & IFF_NOARP){
1137
fprintf(stderr, "Rejecting non-ARP interface \"%s\"\n", ifname);
1142
/* Accept this device */
1144
fprintf(stderr, "Interface \"%s\" is good\n", ifname);
1028
1150
* This function determines if a directory entry in /sys/class/net
1029
1151
* corresponds to an acceptable network device.
1030
1152
* (This function is passed to scandir(3) as a filter function.)
1032
1154
int good_interface(const struct dirent *if_entry){
1156
if(if_entry->d_name[0] == '.'){
1161
if(not get_flags(if_entry->d_name, &ifr)){
1165
if(not good_flags(if_entry->d_name, &ifr)){
1172
* This function determines if a directory entry in /sys/class/net
1173
* corresponds to an acceptable network device which is up.
1174
* (This function is passed to scandir(3) as a filter function.)
1176
int up_interface(const struct dirent *if_entry){
1034
1178
char *flagname = NULL;
1179
if(if_entry->d_name[0] == '.'){
1035
1182
int ret = asprintf(&flagname, "%s/%s/flags", sys_class_net,
1036
1183
if_entry->d_name);
1041
if(if_entry->d_name[0] == '.'){
1185
perror_plus("asprintf");
1044
1188
int flags_fd = (int)TEMP_FAILURE_RETRY(open(flagname, O_RDONLY));
1045
1189
if(flags_fd == -1){
1190
perror_plus("open");
1049
1195
typedef short ifreq_flags; /* ifreq.ifr_flags in netdevice(7) */
1050
1196
/* read line from flags_fd */
1051
ssize_t to_read = (sizeof(ifreq_flags)*2)+3; /* "0x1003\n" */
1197
ssize_t to_read = 2+(sizeof(ifreq_flags)*2)+1; /* "0x1003\n" */
1052
1198
char *flagstring = malloc((size_t)to_read+1); /* +1 for final \0 */
1053
1199
flagstring[(size_t)to_read] = '\0';
1054
1200
if(flagstring == NULL){
1201
perror_plus("malloc");
1056
1202
close(flags_fd);
1282
int notdotentries(const struct dirent *direntry){
1283
/* Skip "." and ".." */
1284
if(direntry->d_name[0] == '.'
1285
and (direntry->d_name[1] == '\0'
1286
or (direntry->d_name[1] == '.'
1287
and direntry->d_name[2] == '\0'))){
1293
/* Is this directory entry a runnable program? */
1294
int runnable_hook(const struct dirent *direntry){
1298
if((direntry->d_name)[0] == '\0'){
1303
/* Save pointer to last character */
1304
char *end = strchr(direntry->d_name, '\0')-1;
1311
if(((direntry->d_name)[0] == '#')
1313
/* Temporary #name# */
1317
/* XXX more rules here */
1319
ret = stat(direntry->d_name, &st);
1322
perror_plus("Could not stat plugin");
1326
if(not (st.st_mode & S_ISREG)){
1327
/* Not a regular file */
1330
if(not (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))){
1331
/* Not executable */
1337
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){
1339
struct timespec now;
1340
struct timespec waited_time;
1341
intmax_t block_time;
1344
if(mc.current_server == NULL){
1347
"Wait until first server is found. No timeout!\n");
1349
ret = avahi_simple_poll_iterate(s, -1);
1352
fprintf(stderr, "Check current_server if we should run it,"
1355
/* the current time */
1356
ret = clock_gettime(CLOCK_MONOTONIC, &now);
1358
perror_plus("clock_gettime");
1361
/* Calculating in ms how long time between now and server
1362
who we visted longest time ago. Now - last seen. */
1363
waited_time.tv_sec = (now.tv_sec
1364
- mc.current_server->last_seen.tv_sec);
1365
waited_time.tv_nsec = (now.tv_nsec
1366
- mc.current_server->last_seen.tv_nsec);
1367
/* total time is 10s/10,000ms.
1368
Converting to s from ms by dividing by 1,000,
1369
and ns to ms by dividing by 1,000,000. */
1370
block_time = ((retry_interval
1371
- ((intmax_t)waited_time.tv_sec * 1000))
1372
- ((intmax_t)waited_time.tv_nsec / 1000000));
1375
fprintf(stderr, "Blocking for %" PRIdMAX " ms\n", block_time);
1378
if(block_time <= 0){
1379
ret = start_mandos_communication(mc.current_server->ip,
1380
mc.current_server->port,
1381
mc.current_server->if_index,
1382
mc.current_server->af);
1384
avahi_simple_poll_quit(mc.simple_poll);
1387
ret = clock_gettime(CLOCK_MONOTONIC,
1388
&mc.current_server->last_seen);
1390
perror_plus("clock_gettime");
1393
mc.current_server = mc.current_server->next;
1394
block_time = 0; /* Call avahi to find new Mandos
1395
servers, but don't block */
1398
ret = avahi_simple_poll_iterate(s, (int)block_time);
1401
if (ret > 0 or errno != EINTR) {
1402
return (ret != 1) ? ret : 0;
1122
1408
int main(int argc, char *argv[]){
1123
1409
AvahiSServiceBrowser *sb = NULL;
1595
/* Work around Debian bug #633582:
1596
<http://bugs.debian.org/633582> */
1599
/* Re-raise priviliges */
1603
perror_plus("seteuid");
1606
if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){
1607
int seckey_fd = open(seckey, O_RDONLY);
1608
if(seckey_fd == -1){
1609
perror_plus("open");
1611
ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));
1613
perror_plus("fstat");
1615
if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){
1616
ret = fchown(seckey_fd, uid, gid);
1618
perror_plus("fchown");
1622
TEMP_FAILURE_RETRY(close(seckey_fd));
1626
if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){
1627
int pubkey_fd = open(pubkey, O_RDONLY);
1628
if(pubkey_fd == -1){
1629
perror_plus("open");
1631
ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));
1633
perror_plus("fstat");
1635
if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){
1636
ret = fchown(pubkey_fd, uid, gid);
1638
perror_plus("fchown");
1642
TEMP_FAILURE_RETRY(close(pubkey_fd));
1646
/* Lower privileges */
1650
perror_plus("seteuid");
1654
/* Find network hooks and run them */
1656
struct dirent **direntries;
1657
struct dirent *direntry;
1658
int numhooks = scandir(HOOKDIR, &direntries, runnable_hook,
1660
int devnull = open("/dev/null", O_RDONLY);
1661
for(int i = 0; i < numhooks; i++){
1662
direntry = direntries[0];
1663
char *fullname = NULL;
1664
ret = asprintf(&fullname, "%s/%s", tempdir,
1667
perror_plus("asprintf");
1670
pid_t hook_pid = fork();
1673
dup2(devnull, STDIN_FILENO);
1675
dup2(STDERR_FILENO, STDOUT_FILENO);
1676
setenv("DEVICE", interface, 1);
1677
setenv("VERBOSE", debug ? "1" : "0", 1);
1678
setenv("MODE", "start", 1);
1679
/* setenv( XXX more here */
1680
ret = execl(fullname, direntry->d_name, "start");
1681
perror_plus("execl");
1295
1692
avahi_set_log_function(empty_log);
1298
1695
if(interface[0] == '\0'){
1299
1696
struct dirent **direntries;
1300
1697
ret = scandir(sys_class_net, &direntries, good_interface,
1357
1754
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1359
perror("sigaction");
1756
perror_plus("sigaction");
1360
1757
return EX_OSERR;
1362
1759
if(old_sigterm_action.sa_handler != SIG_IGN){
1363
1760
ret = sigaction(SIGINT, &sigterm_action, NULL);
1365
perror("sigaction");
1762
perror_plus("sigaction");
1366
1763
exitcode = EX_OSERR;
1370
1767
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1372
perror("sigaction");
1769
perror_plus("sigaction");
1373
1770
return EX_OSERR;
1375
1772
if(old_sigterm_action.sa_handler != SIG_IGN){
1376
1773
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1378
perror("sigaction");
1775
perror_plus("sigaction");
1379
1776
exitcode = EX_OSERR;
1383
1780
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1385
perror("sigaction");
1782
perror_plus("sigaction");
1386
1783
return EX_OSERR;
1388
1785
if(old_sigterm_action.sa_handler != SIG_IGN){
1389
1786
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1391
perror("sigaction");
1788
perror_plus("sigaction");
1392
1789
exitcode = EX_OSERR;
1487
1884
ret = seteuid(uid);
1886
perror_plus("seteuid");
1494
/* sleep checking until interface is running */
1891
/* Sleep checking until interface is running.
1892
Check every 0.25s, up to total time of delay */
1495
1893
for(int i=0; i < delay * 4; i++){
1496
1894
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1498
perror("ioctl SIOCGIFFLAGS");
1896
perror_plus("ioctl SIOCGIFFLAGS");
1499
1897
} else if(network.ifr_flags & IFF_RUNNING){
1502
1900
struct timespec sleeptime = { .tv_nsec = 250000000 };
1503
1901
ret = nanosleep(&sleeptime, NULL);
1504
1902
if(ret == -1 and errno != EINTR){
1505
perror("nanosleep");
1903
perror_plus("nanosleep");
1508
1906
if(not take_down_interface){
1509
1907
/* We won't need the socket anymore */
1510
1908
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1910
perror_plus("close");
1515
1913
#ifdef __linux__
1609
2006
port = (uint16_t)tmpmax;
1610
2007
*address = '\0';
1611
address = connect_to;
1612
2008
/* Colon in address indicates IPv6 */
1614
if(strchr(address, ':') != NULL){
2010
if(strchr(connect_to, ':') != NULL){
2012
/* Accept [] around IPv6 address - see RFC 5952 */
2013
if(connect_to[0] == '[' and address[-1] == ']')
2021
address = connect_to;
1624
2027
while(not quit_now){
1625
2028
ret = start_mandos_communication(address, port, if_index, af);
1626
2029
if(quit_now or ret == 0){
2033
fprintf(stderr, "Retrying in %d seconds\n",
2034
(int)retry_interval);
2036
sleep((int)retry_interval);
1632
2039
if (not quit_now){
1633
2040
exitcode = EXIT_SUCCESS;
1726
2151
ret = seteuid(0);
2153
perror_plus("seteuid");
1730
2155
if(geteuid() == 0){
1731
2156
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1733
perror("ioctl SIOCGIFFLAGS");
2158
perror_plus("ioctl SIOCGIFFLAGS");
1734
2159
} else if(network.ifr_flags & IFF_UP) {
1735
2160
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1736
2161
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1738
perror("ioctl SIOCSIFFLAGS -IFF_UP");
2163
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
1741
2166
ret = (int)TEMP_FAILURE_RETRY(close(sd));
2168
perror_plus("close");
1745
2170
/* Lower privileges permanently */
1747
2172
ret = setuid(uid);
2174
perror_plus("setuid");
1754
/* Removes the temp directory used by GPGME */
2179
/* Removes the GPGME temp directory and all files inside */
1755
2180
if(tempdir_created){
1757
struct dirent *direntry;
1758
d = opendir(tempdir);
1760
if(errno != ENOENT){
1765
direntry = readdir(d);
1766
if(direntry == NULL){
1769
/* Skip "." and ".." */
1770
if(direntry->d_name[0] == '.'
1771
and (direntry->d_name[1] == '\0'
1772
or (direntry->d_name[1] == '.'
1773
and direntry->d_name[2] == '\0'))){
2181
struct dirent **direntries = NULL;
2182
struct dirent *direntry = NULL;
2183
int numentries = scandir(tempdir, &direntries, notdotentries,
2185
if (numentries > 0){
2186
for(int i = 0; i < numentries; i++){
2187
direntry = direntries[i];
1776
2188
char *fullname = NULL;
1777
2189
ret = asprintf(&fullname, "%s/%s", tempdir,
1778
2190
direntry->d_name);
2192
perror_plus("asprintf");
1783
2195
ret = remove(fullname);