/**
* Open the tun device.
*
* @param interfaceName the interface name you *want* to use or NULL to let the kernel decide.
* @param assignedInterfaceName the interface name you get.
* @param log
* @param eh
* @return a file descriptor for the tunnel.
*/
void* TUNConfigurator_initTun(const char* interfaceName,
char assignedInterfaceName[TUNConfigurator_IFNAMSIZ],
struct Log* logger,
struct Except* eh)
{
// Open the descriptor
int tunFd = open("/dev/tun", O_RDWR);
//Get the resulting device name
const char* assignedDevname;
assignedDevname = fdevname(tunFd);
// Extract the number eg: 0 from tun0
int ppa = 0;
for (uint32_t i = 0; i < strlen(assignedDevname); i++) {
if (isdigit(assignedDevname[i])) {
ppa = atoi(assignedDevname);
}
}
if (tunFd < 0 || ppa < 0 ) {
enum Errno err = Errno_get();
close(tunFd);
char* error = NULL;
if (tunFd < 0) {
error = "open(\"/dev/tun\")";
} else if (ppa < 0) {
error = "fdevname/getting number from fdevname";
}
Except_raise(eh, TUNConfigurator_initTun_INTERNAL, error, Errno_strerror(err));
}
// Since devices are numbered rather than named, it's not possible to have tun0 and cjdns0
// so we'll skip the pretty names and call everything tunX
snprintf(assignedInterfaceName, TUNConfigurator_IFNAMSIZ, "tun%d", ppa);
char* error = NULL;
// We want to send IPv6 through our tun device, so we need to be able to specify "ethertype"
int tunhead = 1;
if (ioctl(tunFd,TUNSIFHEAD,&tunhead) == -1) {
error = "TUNSIFHEAD";
}
if (error) {
enum Errno err = Errno_get();
close(tunFd);
Except_raise(eh, TUNConfigurator_initTun_INTERNAL, "%s [%s]", error, Errno_strerror(err));
}
intptr_t ret = (intptr_t) tunFd;
return (void*) ret;
}
struct Iface* TUNInterface_new(const char* interfaceName,
char assignedInterfaceName[TUNInterface_IFNAMSIZ],
int isTapMode,
struct EventBase* base,
struct Log* logger,
struct Except* eh,
struct Allocator* alloc)
{
char deviceFile[TUNInterface_IFNAMSIZ];
if (isTapMode) { Except_throw(eh, "tap mode not supported on this platform"); }
// We are on FreeBSD so we just need to read /dev/tunxx to create the tun interface
if (interfaceName) {
snprintf(deviceFile,TUNInterface_IFNAMSIZ,"/dev/%s",interfaceName);
} else {
snprintf(deviceFile,TUNInterface_IFNAMSIZ,"%s","/dev/tun");
}
// Open the descriptor
int tunFd = open(deviceFile, O_RDWR);
//Get the resulting device name
const char* assignedDevname;
assignedDevname = fdevname(tunFd);
// Extract the number eg: 0 from tun0
int ppa = 0;
for (uint32_t i = 0; i < strlen(assignedDevname); i++) {
if (isdigit(assignedDevname[i])) {
ppa = atoi(assignedDevname+i);
break;
}
}
if (tunFd < 0 || ppa < 0 ) {
int err = errno;
close(tunFd);
char* error = NULL;
if (tunFd < 0) {
error = "open(\"/dev/tun\")";
} else if (ppa < 0) {
error = "fdevname/getting number from fdevname";
}
Except_throw(eh, "%s [%s]", error, strerror(err));
}
// Since devices are numbered rather than named, it's not possible to have tun0 and cjdns0
// so we'll skip the pretty names and call everything tunX
if (assignedInterfaceName) {
snprintf(assignedInterfaceName, TUNInterface_IFNAMSIZ, "tun%d", ppa);
}
char* error = NULL;
// We want to send IPv6 through our tun device, so we need to be able to specify "ethertype"
int tunhead = 1;
if (ioctl(tunFd,TUNSIFHEAD,&tunhead) == -1) {
error = "TUNSIFHEAD";
}
if (error) {
int err = errno;
close(tunFd);
Except_throw(eh, "%s [%s]", error, strerror(err));
}
struct Pipe* p = Pipe_forFiles(tunFd, tunFd, base, eh, alloc);
struct BSDMessageTypeWrapper* bmtw = BSDMessageTypeWrapper_new(alloc, logger);
Iface_plumb(&p->iface, &bmtw->wireSide);
return &bmtw->inside;
}
