62
62
#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,
64
64
#include <assert.h> /* assert() */
65
#include <errno.h> /* perror(), errno */
66
#include <time.h> /* nanosleep(), time() */
65
#include <errno.h> /* perror(), errno,
66
program_invocation_short_name */
67
#include <time.h> /* nanosleep(), time(), sleep() */
67
68
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
68
69
SIOCSIFFLAGS, if_indextoname(),
69
70
if_nametoindex(), IF_NAMESIZE */
137
151
gnutls_dh_params_t dh_params;
138
152
const char *priority;
154
server *current_server;
140
155
} mandos_context;
142
157
/* global context so signal handler can reach it*/
143
158
mandos_context mc = { .simple_poll = NULL, .server = NULL,
144
159
.dh_bits = 1024, .priority = "SECURE256"
145
":!CTYPE-X.509:+CTYPE-OPENPGP" };
160
":!CTYPE-X.509:+CTYPE-OPENPGP",
161
.current_server = NULL };
147
163
sig_atomic_t quit_now = 0;
148
164
int signal_received = 0;
166
/* Function to use when printing errors */
167
void perror_plus(const char *print_text){
168
fprintf(stderr, "Mandos plugin %s: ",
169
program_invocation_short_name);
151
174
* Make additional room in "buffer" for at least BUFFER_SIZE more
152
175
* bytes. "buffer_capacity" is how much is currently allocated,
164
187
return buffer_capacity;
190
/* Add server to set of servers to retry periodically */
191
int add_server(const char *ip, uint16_t port,
192
AvahiIfIndex if_index,
195
server *new_server = malloc(sizeof(server));
196
if(new_server == NULL){
197
perror_plus("malloc");
200
*new_server = (server){ .ip = strdup(ip),
202
.if_index = if_index,
204
if(new_server->ip == NULL){
205
perror_plus("strdup");
208
/* Special case of first server */
209
if (mc.current_server == NULL){
210
new_server->next = new_server;
211
new_server->prev = new_server;
212
mc.current_server = new_server;
213
/* Place the new server last in the list */
215
new_server->next = mc.current_server;
216
new_server->prev = mc.current_server->prev;
217
new_server->prev->next = new_server;
218
mc.current_server->prev = new_server;
220
ret = clock_gettime(CLOCK_MONOTONIC, &mc.current_server->last_seen);
222
perror_plus("clock_gettime");
168
229
* Initialize GPGME.
1015
1079
signal_received = sig;
1016
1080
int old_errno = errno;
1081
/* set main loop to exit */
1017
1082
if(mc.simple_poll != NULL){
1018
1083
avahi_simple_poll_quit(mc.simple_poll);
1020
1085
errno = old_errno;
1089
* This function determines if a directory entry in /sys/class/net
1090
* corresponds to an acceptable network device.
1091
* (This function is passed to scandir(3) as a filter function.)
1093
int good_interface(const struct dirent *if_entry){
1095
char *flagname = NULL;
1096
if(if_entry->d_name[0] == '.'){
1099
int ret = asprintf(&flagname, "%s/%s/flags", sys_class_net,
1102
perror_plus("asprintf");
1105
int flags_fd = (int)TEMP_FAILURE_RETRY(open(flagname, O_RDONLY));
1107
perror_plus("open");
1112
typedef short ifreq_flags; /* ifreq.ifr_flags in netdevice(7) */
1113
/* read line from flags_fd */
1114
ssize_t to_read = 2+(sizeof(ifreq_flags)*2)+1; /* "0x1003\n" */
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char *flagstring = malloc((size_t)to_read+1); /* +1 for final \0 */
1116
flagstring[(size_t)to_read] = '\0';
1117
if(flagstring == NULL){
1118
perror_plus("malloc");
1123
ssret = (ssize_t)TEMP_FAILURE_RETRY(read(flags_fd, flagstring,
1126
perror_plus("read");
1140
tmpmax = strtoimax(flagstring, &tmp, 0);
1141
if(errno != 0 or tmp == flagstring or (*tmp != '\0'
1142
and not (isspace(*tmp)))
1143
or tmpmax != (ifreq_flags)tmpmax){
1145
fprintf(stderr, "Invalid flags \"%s\" for interface \"%s\"\n",
1146
flagstring, if_entry->d_name);
1152
ifreq_flags flags = (ifreq_flags)tmpmax;
1153
/* Reject the loopback device */
1154
if(flags & IFF_LOOPBACK){
1156
fprintf(stderr, "Rejecting loopback interface \"%s\"\n",
1161
/* Accept point-to-point devices only if connect_to is specified */
1162
if(connect_to != NULL and (flags & IFF_POINTOPOINT)){
1164
fprintf(stderr, "Accepting point-to-point interface \"%s\"\n",
1169
/* Otherwise, reject non-broadcast-capable devices */
1170
if(not (flags & IFF_BROADCAST)){
1172
fprintf(stderr, "Rejecting non-broadcast interface \"%s\"\n",
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/* Reject non-ARP interfaces (including dummy interfaces) */
1178
if(flags & IFF_NOARP){
1180
fprintf(stderr, "Rejecting non-ARP interface \"%s\"\n",
1185
/* Accept this device */
1187
fprintf(stderr, "Interface \"%s\" is acceptable\n",
1193
int notdotentries(const struct dirent *direntry){
1194
/* Skip "." and ".." */
1195
if(direntry->d_name[0] == '.'
1196
and (direntry->d_name[1] == '\0'
1197
or (direntry->d_name[1] == '.'
1198
and direntry->d_name[2] == '\0'))){
1204
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){
1206
struct timespec now;
1207
struct timespec waited_time;
1208
intmax_t block_time;
1211
if(mc.current_server == NULL){
1214
"Wait until first server is found. No timeout!\n");
1216
ret = avahi_simple_poll_iterate(s, -1);
1219
fprintf(stderr, "Check current_server if we should run it,"
1222
/* the current time */
1223
ret = clock_gettime(CLOCK_MONOTONIC, &now);
1225
perror_plus("clock_gettime");
1228
/* Calculating in ms how long time between now and server
1229
who we visted longest time ago. Now - last seen. */
1230
waited_time.tv_sec = (now.tv_sec
1231
- mc.current_server->last_seen.tv_sec);
1232
waited_time.tv_nsec = (now.tv_nsec
1233
- mc.current_server->last_seen.tv_nsec);
1234
/* total time is 10s/10,000ms.
1235
Converting to s from ms by dividing by 1,000,
1236
and ns to ms by dividing by 1,000,000. */
1237
block_time = ((retry_interval
1238
- ((intmax_t)waited_time.tv_sec * 1000))
1239
- ((intmax_t)waited_time.tv_nsec / 1000000));
1242
fprintf(stderr, "Blocking for %" PRIdMAX " ms\n", block_time);
1245
if(block_time <= 0){
1246
ret = start_mandos_communication(mc.current_server->ip,
1247
mc.current_server->port,
1248
mc.current_server->if_index,
1249
mc.current_server->af);
1251
avahi_simple_poll_quit(mc.simple_poll);
1254
ret = clock_gettime(CLOCK_MONOTONIC,
1255
&mc.current_server->last_seen);
1257
perror_plus("clock_gettime");
1260
mc.current_server = mc.current_server->next;
1261
block_time = 0; /* Call avahi to find new Mandos
1262
servers, but don't block */
1265
ret = avahi_simple_poll_iterate(s, (int)block_time);
1268
if (ret > 0 or errno != EINTR) {
1269
return (ret != 1) ? ret : 0;
1023
1275
int main(int argc, char *argv[]){
1024
1276
AvahiSServiceBrowser *sb = NULL;
1462
/* Work around Debian bug #633582:
1463
<http://bugs.debian.org/633582> */
1466
/* Re-raise priviliges */
1470
perror_plus("seteuid");
1473
if(strcmp(seckey, PATHDIR "/" SECKEY) == 0){
1474
int seckey_fd = open(seckey, O_RDONLY);
1475
if(seckey_fd == -1){
1476
perror_plus("open");
1478
ret = (int)TEMP_FAILURE_RETRY(fstat(seckey_fd, &st));
1480
perror_plus("fstat");
1482
if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){
1483
ret = fchown(seckey_fd, uid, gid);
1485
perror_plus("fchown");
1489
TEMP_FAILURE_RETRY(close(seckey_fd));
1493
if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){
1494
int pubkey_fd = open(pubkey, O_RDONLY);
1495
if(pubkey_fd == -1){
1496
perror_plus("open");
1498
ret = (int)TEMP_FAILURE_RETRY(fstat(pubkey_fd, &st));
1500
perror_plus("fstat");
1502
if(S_ISREG(st.st_mode) and st.st_uid == 0 and st.st_gid == 0){
1503
ret = fchown(pubkey_fd, uid, gid);
1505
perror_plus("fchown");
1509
TEMP_FAILURE_RETRY(close(pubkey_fd));
1513
/* Lower privileges */
1517
perror_plus("seteuid");
1197
1522
avahi_set_log_function(empty_log);
1525
if(interface[0] == '\0'){
1526
struct dirent **direntries;
1527
ret = scandir(sys_class_net, &direntries, good_interface,
1530
/* Pick the first good interface */
1531
interface = strdup(direntries[0]->d_name);
1533
fprintf(stderr, "Using interface \"%s\"\n", interface);
1535
if(interface == NULL){
1536
perror_plus("malloc");
1538
exitcode = EXIT_FAILURE;
1544
fprintf(stderr, "Could not find a network interface\n");
1545
exitcode = EXIT_FAILURE;
1200
1550
/* Initialize Avahi early so avahi_simple_poll_quit() can be called
1201
1551
from the signal handler */
1234
1584
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
1236
perror("sigaction");
1586
perror_plus("sigaction");
1237
1587
return EX_OSERR;
1239
1589
if(old_sigterm_action.sa_handler != SIG_IGN){
1240
1590
ret = sigaction(SIGINT, &sigterm_action, NULL);
1242
perror("sigaction");
1592
perror_plus("sigaction");
1243
1593
exitcode = EX_OSERR;
1247
1597
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
1249
perror("sigaction");
1599
perror_plus("sigaction");
1250
1600
return EX_OSERR;
1252
1602
if(old_sigterm_action.sa_handler != SIG_IGN){
1253
1603
ret = sigaction(SIGHUP, &sigterm_action, NULL);
1255
perror("sigaction");
1605
perror_plus("sigaction");
1256
1606
exitcode = EX_OSERR;
1260
1610
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1262
perror("sigaction");
1612
perror_plus("sigaction");
1263
1613
return EX_OSERR;
1265
1615
if(old_sigterm_action.sa_handler != SIG_IGN){
1266
1616
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1268
perror("sigaction");
1618
perror_plus("sigaction");
1269
1619
exitcode = EX_OSERR;
1274
1624
/* If the interface is down, bring it up */
1275
if(interface[0] != '\0'){
1625
if(strcmp(interface, "none") != 0){
1276
1626
if_index = (AvahiIfIndex) if_nametoindex(interface);
1277
1627
if(if_index == 0){
1278
1628
fprintf(stderr, "No such interface: \"%s\"\n", interface);
1364
1714
ret = seteuid(uid);
1716
perror_plus("seteuid");
1371
/* sleep checking until interface is running */
1721
/* Sleep checking until interface is running.
1722
Check every 0.25s, up to total time of delay */
1372
1723
for(int i=0; i < delay * 4; i++){
1373
1724
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1375
perror("ioctl SIOCGIFFLAGS");
1726
perror_plus("ioctl SIOCGIFFLAGS");
1376
1727
} else if(network.ifr_flags & IFF_RUNNING){
1379
1730
struct timespec sleeptime = { .tv_nsec = 250000000 };
1380
1731
ret = nanosleep(&sleeptime, NULL);
1381
1732
if(ret == -1 and errno != EINTR){
1382
perror("nanosleep");
1733
perror_plus("nanosleep");
1385
1736
if(not take_down_interface){
1386
1737
/* We won't need the socket anymore */
1387
1738
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1740
perror_plus("close");
1392
1743
#ifdef __linux__
1615
1979
ret = seteuid(0);
1981
perror_plus("seteuid");
1619
1983
if(geteuid() == 0){
1620
1984
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1622
perror("ioctl SIOCGIFFLAGS");
1986
perror_plus("ioctl SIOCGIFFLAGS");
1623
1987
} else if(network.ifr_flags & IFF_UP) {
1624
1988
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1625
1989
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1627
perror("ioctl SIOCSIFFLAGS");
1991
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
1630
1994
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1996
perror_plus("close");
1634
1998
/* Lower privileges permanently */
1636
2000
ret = setuid(uid);
2002
perror_plus("setuid");
1643
/* Removes the temp directory used by GPGME */
2007
/* Removes the GPGME temp directory and all files inside */
1644
2008
if(tempdir_created){
1646
struct dirent *direntry;
1647
d = opendir(tempdir);
1649
if(errno != ENOENT){
1654
direntry = readdir(d);
1655
if(direntry == NULL){
1658
/* Skip "." and ".." */
1659
if(direntry->d_name[0] == '.'
1660
and (direntry->d_name[1] == '\0'
1661
or (direntry->d_name[1] == '.'
1662
and direntry->d_name[2] == '\0'))){
2009
struct dirent **direntries = NULL;
2010
struct dirent *direntry = NULL;
2011
int numentries = scandir(tempdir, &direntries, notdotentries,
2013
if (numentries > 0){
2014
for(int i = 0; i < numentries; i++){
2015
direntry = direntries[i];
1665
2016
char *fullname = NULL;
1666
2017
ret = asprintf(&fullname, "%s/%s", tempdir,
1667
2018
direntry->d_name);
2020
perror_plus("asprintf");
1672
2023
ret = remove(fullname);