62
62
#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,
64
64
#include <assert.h> /* assert() */
65
#include <errno.h> /* perror(), errno,
66
program_invocation_short_name */
65
#include <errno.h> /* perror(), errno */
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66
#include <time.h> /* nanosleep(), time(), sleep() */
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67
#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
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SIOCSIFFLAGS, if_indextoname(),
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#include <unistd.h> /* close(), SEEK_SET, off_t, write(),
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getuid(), getgid(), seteuid(),
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setgid(), pause() */
77
#include <arpa/inet.h> /* inet_pton(), htons, inet_ntop() */
76
#include <arpa/inet.h> /* inet_pton(), htons */
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#include <iso646.h> /* not, or, and */
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78
#include <argp.h> /* struct argp_option, error_t, struct
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79
argp_state, struct argp,
151
139
gnutls_dh_params_t dh_params;
152
140
const char *priority;
154
server *current_server;
155
142
} mandos_context;
157
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/* global context so signal handler can reach it*/
158
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mandos_context mc = { .simple_poll = NULL, .server = NULL,
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.dh_bits = 1024, .priority = "SECURE256"
160
":!CTYPE-X.509:+CTYPE-OPENPGP",
161
.current_server = NULL };
147
":!CTYPE-X.509:+CTYPE-OPENPGP" };
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149
sig_atomic_t quit_now = 0;
164
150
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);
174
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* Make additional room in "buffer" for at least BUFFER_SIZE more
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154
* bytes. "buffer_capacity" is how much is currently allocated,
187
166
return buffer_capacity;
190
int add_server(const char *ip, uint16_t port,
191
AvahiIfIndex if_index,
194
server *new_server = malloc(sizeof(server));
195
if(new_server == NULL){
196
perror_plus("malloc");
199
*new_server = (server){ .ip = strdup(ip),
201
.if_index = if_index,
203
if(new_server->ip == NULL){
204
perror_plus("strdup");
207
/* unique case of first server */
208
if (mc.current_server == NULL){
209
new_server->next = new_server;
210
new_server->prev = new_server;
211
mc.current_server = new_server;
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/* Placing the new server last in the list */
214
new_server->next = mc.current_server;
215
new_server->prev = mc.current_server->prev;
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new_server->prev->next = new_server;
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mc.current_server->prev = new_server;
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ret = clock_gettime(CLOCK_MONOTONIC, &mc.current_server->last_seen);
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perror_plus("clock_gettime");
228
170
* Initialize GPGME.
483
425
/* OpenPGP credentials */
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ret = gnutls_certificate_allocate_credentials(&mc.cred);
426
gnutls_certificate_allocate_credentials(&mc.cred);
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if(ret != GNUTLS_E_SUCCESS){
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fprintf(stderr, "GnuTLS memory error: %s\n",
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fprintf(stderr, "GnuTLS memory error: %s\n", /* Spurious warning
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safer_gnutls_strerror(ret));
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gnutls_global_deinit();
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if(af == AF_INET6 and if_index != AVAHI_IF_UNSPEC){
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652
char interface[IF_NAMESIZE];
708
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if(if_indextoname((unsigned int)if_index, interface) == NULL){
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perror_plus("if_indextoname");
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perror("if_indextoname");
711
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fprintf(stderr, "Connection to: %s%%%s, port %" PRIu16 "\n",
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657
ip, interface, port);
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1032
int good_interface(const struct dirent *if_entry){
1094
1034
char *flagname = NULL;
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if(if_entry->d_name[0] == '.'){
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1035
int ret = asprintf(&flagname, "%s/%s/flags", sys_class_net,
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1036
if_entry->d_name);
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perror_plus("asprintf");
1041
if(if_entry->d_name[0] == '.'){
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1044
int flags_fd = (int)TEMP_FAILURE_RETRY(open(flagname, O_RDONLY));
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1045
if(flags_fd == -1){
1106
perror_plus("open");
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1049
typedef short ifreq_flags; /* ifreq.ifr_flags in netdevice(7) */
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1050
/* read line from flags_fd */
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ssize_t to_read = 2+(sizeof(ifreq_flags)*2)+1; /* "0x1003\n" */
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ssize_t to_read = (sizeof(ifreq_flags)*2)+3; /* "0x1003\n" */
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char *flagstring = malloc((size_t)to_read+1); /* +1 for final \0 */
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flagstring[(size_t)to_read] = '\0';
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if(flagstring == NULL){
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perror_plus("malloc");
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1056
close(flags_fd);
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int notdotentries(const struct dirent *direntry){
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/* Skip "." and ".." */
1194
if(direntry->d_name[0] == '.'
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and (direntry->d_name[1] == '\0'
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or (direntry->d_name[1] == '.'
1197
and direntry->d_name[2] == '\0'))){
1203
int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){
1205
struct timespec now;
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struct timespec waited_time;
1207
intmax_t block_time;
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if(mc.current_server == NULL){
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"Wait until first server is found. No timeout!\n");
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ret = avahi_simple_poll_iterate(s, -1);
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fprintf(stderr, "Check current_server if we should run it,"
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/* the current time */
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ret = clock_gettime(CLOCK_MONOTONIC, &now);
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perror_plus("clock_gettime");
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/* Calculating in ms how long time between now and server
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who we visted longest time ago. Now - last seen. */
1229
waited_time.tv_sec = (now.tv_sec
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- mc.current_server->last_seen.tv_sec);
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waited_time.tv_nsec = (now.tv_nsec
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- mc.current_server->last_seen.tv_nsec);
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/* total time is 10s/10,000ms.
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Converting to s from ms by dividing by 1,000,
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and ns to ms by dividing by 1,000,000. */
1236
block_time = ((retry_interval
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- ((intmax_t)waited_time.tv_sec * 1000))
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- ((intmax_t)waited_time.tv_nsec / 1000000));
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fprintf(stderr, "Blocking for %ld ms\n", block_time);
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if(block_time <= 0){
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ret = start_mandos_communication(mc.current_server->ip,
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mc.current_server->port,
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mc.current_server->if_index,
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mc.current_server->af);
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avahi_simple_poll_quit(mc.simple_poll);
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ret = clock_gettime(CLOCK_MONOTONIC,
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&mc.current_server->last_seen);
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perror_plus("clock_gettime");
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mc.current_server = mc.current_server->next;
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block_time = 0; /* Call avahi to find new Mandos
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servers, but don't block */
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ret = avahi_simple_poll_iterate(s, (int)block_time);
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if (ret > 0 or errno != EINTR) {
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return (ret != 1) ? ret : 0;
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int main(int argc, char *argv[]){
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1123
AvahiSServiceBrowser *sb = NULL;
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bool gnutls_initialized = false;
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bool gpgme_initialized = false;
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float delay = 2.5f;
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double retry_interval = 10; /* 10s between trying a server and
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retrying the same server again */
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struct sigaction old_sigterm_action = { .sa_handler = SIG_DFL };
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struct sigaction sigterm_action = { .sa_handler = handle_sigterm };
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if(errno != 0 or tmp == arg or *tmp != '\0'){
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argp_error(state, "Bad delay");
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case 132: /* --retry */
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retry_interval = strtod(arg, &tmp);
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if(errno != 0 or tmp == arg or *tmp != '\0'
1414
or (retry_interval * 1000) > INT_MAX){
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argp_error(state, "Bad retry interval");
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* These reproduce what we would get without ARGP_NO_HELP
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sigemptyset(&sigterm_action.sa_mask);
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ret = sigaddset(&sigterm_action.sa_mask, SIGINT);
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perror_plus("sigaddset");
1337
perror("sigaddset");
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1338
exitcode = EX_OSERR;
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ret = sigaddset(&sigterm_action.sa_mask, SIGHUP);
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perror_plus("sigaddset");
1343
perror("sigaddset");
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1344
exitcode = EX_OSERR;
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1347
ret = sigaddset(&sigterm_action.sa_mask, SIGTERM);
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perror_plus("sigaddset");
1349
perror("sigaddset");
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1350
exitcode = EX_OSERR;
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1357
ret = sigaction(SIGINT, NULL, &old_sigterm_action);
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perror_plus("sigaction");
1359
perror("sigaction");
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return EX_OSERR;
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1362
if(old_sigterm_action.sa_handler != SIG_IGN){
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ret = sigaction(SIGINT, &sigterm_action, NULL);
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perror_plus("sigaction");
1365
perror("sigaction");
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1366
exitcode = EX_OSERR;
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1370
ret = sigaction(SIGHUP, NULL, &old_sigterm_action);
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perror_plus("sigaction");
1372
perror("sigaction");
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1373
return EX_OSERR;
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1375
if(old_sigterm_action.sa_handler != SIG_IGN){
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1376
ret = sigaction(SIGHUP, &sigterm_action, NULL);
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perror_plus("sigaction");
1378
perror("sigaction");
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1379
exitcode = EX_OSERR;
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1383
ret = sigaction(SIGTERM, NULL, &old_sigterm_action);
1550
perror_plus("sigaction");
1385
perror("sigaction");
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1386
return EX_OSERR;
1553
1388
if(old_sigterm_action.sa_handler != SIG_IGN){
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1389
ret = sigaction(SIGTERM, &sigterm_action, NULL);
1556
perror_plus("sigaction");
1391
perror("sigaction");
1557
1392
exitcode = EX_OSERR;
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1442
ret = seteuid(uid);
1609
perror_plus("seteuid");
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1448
strcpy(network.ifr_name, interface);
1614
1449
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1616
perror_plus("ioctl SIOCGIFFLAGS");
1451
perror("ioctl SIOCGIFFLAGS");
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1452
#ifdef __linux__
1618
1453
if(restore_loglevel){
1619
1454
ret = klogctl(7, NULL, 0);
1621
perror_plus("klogctl");
1624
1459
#endif /* __linux__ */
1637
1472
ret = ioctl(sd, SIOCSIFFLAGS, &network);
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1474
take_down_interface = false;
1640
perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");
1475
perror("ioctl SIOCSIFFLAGS +IFF_UP");
1641
1476
exitcode = EX_OSERR;
1642
1477
#ifdef __linux__
1643
1478
if(restore_loglevel){
1644
1479
ret = klogctl(7, NULL, 0);
1646
perror_plus("klogctl");
1649
1484
#endif /* __linux__ */
1652
1487
ret = seteuid(uid);
1654
perror_plus("seteuid");
1659
/* Sleep checking until interface is running.
1660
Check every 0.25s, up to total time of delay */
1494
/* sleep checking until interface is running */
1661
1495
for(int i=0; i < delay * 4; i++){
1662
1496
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1664
perror_plus("ioctl SIOCGIFFLAGS");
1498
perror("ioctl SIOCGIFFLAGS");
1665
1499
} else if(network.ifr_flags & IFF_RUNNING){
1668
1502
struct timespec sleeptime = { .tv_nsec = 250000000 };
1669
1503
ret = nanosleep(&sleeptime, NULL);
1670
1504
if(ret == -1 and errno != EINTR){
1671
perror_plus("nanosleep");
1505
perror("nanosleep");
1674
1508
if(not take_down_interface){
1675
1509
/* We won't need the socket anymore */
1676
1510
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1678
perror_plus("close");
1681
1515
#ifdef __linux__
1856
1691
fprintf(stderr, "Starting Avahi loop search\n");
1859
ret = avahi_loop_with_timeout(mc.simple_poll,
1860
(int)(retry_interval * 1000));
1862
fprintf(stderr, "avahi_loop_with_timeout exited %s\n",
1863
(ret == 0) ? "successfully" : "with error");
1694
avahi_simple_poll_loop(mc.simple_poll);
1888
1718
if(gpgme_initialized){
1889
1719
gpgme_release(mc.ctx);
1892
/* Cleans up the circular linked list of Mandos servers the client
1894
if(mc.current_server != NULL){
1895
mc.current_server->prev->next = NULL;
1896
while(mc.current_server != NULL){
1897
server *next = mc.current_server->next;
1898
free(mc.current_server);
1899
mc.current_server = next;
1903
1722
/* Take down the network interface */
1904
1723
if(take_down_interface){
1907
1726
ret = seteuid(0);
1909
perror_plus("seteuid");
1911
1730
if(geteuid() == 0){
1912
1731
ret = ioctl(sd, SIOCGIFFLAGS, &network);
1914
perror_plus("ioctl SIOCGIFFLAGS");
1733
perror("ioctl SIOCGIFFLAGS");
1915
1734
} else if(network.ifr_flags & IFF_UP) {
1916
1735
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
1917
1736
ret = ioctl(sd, SIOCSIFFLAGS, &network);
1919
perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");
1738
perror("ioctl SIOCSIFFLAGS -IFF_UP");
1922
1741
ret = (int)TEMP_FAILURE_RETRY(close(sd));
1924
perror_plus("close");
1926
1745
/* Lower privileges permanently */
1928
1747
ret = setuid(uid);
1930
perror_plus("setuid");
1935
/* Removes the GPGME temp directory and all files inside */
1754
/* Removes the temp directory used by GPGME */
1936
1755
if(tempdir_created){
1937
struct dirent **direntries = NULL;
1938
struct dirent *direntry = NULL;
1939
ret = scandir(tempdir, &direntries, notdotentries, alphasort);
1941
for(int i = 0; i < ret; i++){
1942
direntry = direntries[i];
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'))){
1943
1776
char *fullname = NULL;
1944
1777
ret = asprintf(&fullname, "%s/%s", tempdir,
1945
1778
direntry->d_name);
1947
perror_plus("asprintf");
1950
1783
ret = remove(fullname);