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#include <assert.h> /* assert() */
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#include <errno.h> /* perror(), errno */
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#include <time.h> /* nanosleep(), time() */
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#include <time.h> /* nanosleep(), time(), sleep() */
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#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,
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SIOCSIFFLAGS, if_indextoname(),
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if_nametoindex(), IF_NAMESIZE */
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static const char mandos_protocol_version[] = "1";
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const char *argp_program_version = "mandos-client " VERSION;
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const char *argp_program_bug_address = "<mandos@fukt.bsnet.se>";
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static const char sys_class_net[] = "/sys/class/net";
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char *connect_to = NULL;
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/* Used for passing in values through the Avahi callback functions */
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errno = old_errno;
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* This function determines if a directory entry in /sys/class/net
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* corresponds to an acceptable network device.
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* (This function is passed to scandir(3) as a filter function.)
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int good_interface(const struct dirent *if_entry){
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char *flagname = NULL;
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int ret = asprintf(&flagname, "%s/%s/flags", sys_class_net,
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if(if_entry->d_name[0] == '.'){
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int flags_fd = (int)TEMP_FAILURE_RETRY(open(flagname, O_RDONLY));
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typedef short ifreq_flags; /* ifreq.ifr_flags in netdevice(7) */
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/* read line from flags_fd */
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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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ssret = (ssize_t)TEMP_FAILURE_RETRY(read(flags_fd, flagstring,
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tmpmax = strtoimax(flagstring, &tmp, 0);
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if(errno != 0 or tmp == flagstring or (*tmp != '\0'
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and not (isspace(*tmp)))
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or tmpmax != (ifreq_flags)tmpmax){
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fprintf(stderr, "Invalid flags \"%s\" for interface \"%s\"\n",
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flagstring, if_entry->d_name);
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ifreq_flags flags = (ifreq_flags)tmpmax;
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/* Reject the loopback device */
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if(flags & IFF_LOOPBACK){
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fprintf(stderr, "Rejecting loopback interface \"%s\"\n",
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/* Accept point-to-point devices only if connect_to is specified */
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if(connect_to != NULL and (flags & IFF_POINTOPOINT)){
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fprintf(stderr, "Accepting point-to-point interface \"%s\"\n",
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/* Otherwise, reject non-broadcast-capable devices */
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if(not (flags & IFF_BROADCAST)){
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fprintf(stderr, "Rejecting non-broadcast interface \"%s\"\n",
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/* Accept this device */
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fprintf(stderr, "Interface \"%s\" is acceptable\n",
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int main(int argc, char *argv[]){
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1123
AvahiSServiceBrowser *sb = NULL;
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1126
intmax_t tmpmax;
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1128
int exitcode = EXIT_SUCCESS;
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const char *interface = "eth0";
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const char *interface = "";
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struct ifreq network;
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bool take_down_interface = false;
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char *connect_to = NULL;
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char tempdir[] = "/tmp/mandosXXXXXX";
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bool tempdir_created = false;
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AvahiIfIndex if_index = AVAHI_IF_UNSPEC;
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avahi_set_log_function(empty_log);
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if(interface[0] == '\0'){
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struct dirent **direntries;
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ret = scandir(sys_class_net, &direntries, good_interface,
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/* Pick the first good interface */
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interface = strdup(direntries[0]->d_name);
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fprintf(stderr, "Using interface \"%s\"\n", interface);
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if(interface == NULL){
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exitcode = EXIT_FAILURE;
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fprintf(stderr, "Could not find a network interface\n");
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exitcode = EXIT_FAILURE;
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/* Initialize Avahi early so avahi_simple_poll_quit() can be called
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from the signal handler */
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/* If the interface is down, bring it up */
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if(interface[0] != '\0'){
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if(strcmp(interface, "none") != 0){
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if_index = (AvahiIfIndex) if_nametoindex(interface);
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1400
if(if_index == 0){
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fprintf(stderr, "No such interface: \"%s\"\n", interface);
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ret = start_mandos_communication(address, port, if_index, af);
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exitcode = EX_NOHOST;
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exitcode = EX_USAGE;
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exitcode = EX_IOERR;
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exitcode = EX_PROTOCOL;
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exitcode = EX_OSERR;
1624
while(not quit_now){
1625
ret = start_mandos_communication(address, port, if_index, af);
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if(quit_now or ret == 0){
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exitcode = EXIT_SUCCESS;
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1735
network.ifr_flags &= ~(short)IFF_UP; /* clear flag */
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ret = ioctl(sd, SIOCSIFFLAGS, &network);
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perror("ioctl SIOCSIFFLAGS");
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perror("ioctl SIOCSIFFLAGS -IFF_UP");
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ret = (int)TEMP_FAILURE_RETRY(close(sd));