iodine/src/tun.c
2012-02-04 20:34:02 +01:00

538 lines
13 KiB
C

/*
* Copyright (c) 2006-2009 Bjorn Andersson <flex@kryo.se>, Erik Ekman <yarrick@kryo.se>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <stdint.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#ifdef WINDOWS32
#include <winsock2.h>
#include <winioctl.h>
#include "windows.h"
HANDLE dev_handle;
struct tun_data data;
static void get_name(char *ifname, int namelen, char *dev_name);
#define TAP_CONTROL_CODE(request,method) CTL_CODE(FILE_DEVICE_UNKNOWN, request, method, FILE_ANY_ACCESS)
#define TAP_IOCTL_CONFIG_TUN TAP_CONTROL_CODE(10, METHOD_BUFFERED)
#define TAP_IOCTL_SET_MEDIA_STATUS TAP_CONTROL_CODE(6, METHOD_BUFFERED)
#define TAP_ADAPTER_KEY "SYSTEM\\CurrentControlSet\\Control\\Class\\{4D36E972-E325-11CE-BFC1-08002BE10318}"
#define NETWORK_KEY "SYSTEM\\CurrentControlSet\\Control\\Network\\{4D36E972-E325-11CE-BFC1-08002BE10318}"
#define TAP_DEVICE_SPACE "\\\\.\\Global\\"
#define TAP_VERSION_ID_0801 "tap0801"
#define TAP_VERSION_ID_0901 "tap0901"
#define KEY_COMPONENT_ID "ComponentId"
#define NET_CFG_INST_ID "NetCfgInstanceId"
#else
#include <err.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#define TUN_MAX_TRY 50
#endif
#include "tun.h"
#include "common.h"
char if_name[250];
#ifndef WINDOWS32
#ifdef LINUX
#include <sys/ioctl.h>
#include <net/if.h>
#include <linux/if_tun.h>
int
open_tun(const char *tun_device)
{
int i;
int tun_fd;
struct ifreq ifreq;
char *tunnel = "/dev/net/tun";
if ((tun_fd = open(tunnel, O_RDWR)) < 0) {
warn("open_tun: %s: %s", tunnel, strerror(errno));
return -1;
}
memset(&ifreq, 0, sizeof(ifreq));
ifreq.ifr_flags = IFF_TUN;
if (tun_device != NULL) {
strncpy(ifreq.ifr_name, tun_device, IFNAMSIZ);
ifreq.ifr_name[IFNAMSIZ-1] = '\0';
strncpy(if_name, tun_device, sizeof(if_name));
if_name[sizeof(if_name)-1] = '\0';
if (ioctl(tun_fd, TUNSETIFF, (void *) &ifreq) != -1) {
fprintf(stderr, "Opened %s\n", ifreq.ifr_name);
return tun_fd;
}
if (errno != EBUSY) {
warn("open_tun: ioctl[TUNSETIFF]: %s", strerror(errno));
return -1;
}
} else {
for (i = 0; i < TUN_MAX_TRY; i++) {
snprintf(ifreq.ifr_name, IFNAMSIZ, "dns%d", i);
if (ioctl(tun_fd, TUNSETIFF, (void *) &ifreq) != -1) {
fprintf(stderr, "Opened %s\n", ifreq.ifr_name);
snprintf(if_name, sizeof(if_name), "dns%d", i);
return tun_fd;
}
if (errno != EBUSY) {
warn("open_tun: ioctl[TUNSETIFF]: %s", strerror(errno));
return -1;
}
}
warn("open_tun: Couldn't set interface name");
}
warn("error when opening tun");
return -1;
}
#else /* BSD */
int
open_tun(const char *tun_device)
{
int i;
int tun_fd;
char tun_name[50];
if (tun_device != NULL) {
snprintf(tun_name, sizeof(tun_name), "/dev/%s", tun_device);
strncpy(if_name, tun_device, sizeof(if_name));
if_name[sizeof(if_name)-1] = '\0';
if ((tun_fd = open(tun_name, O_RDWR)) < 0) {
warn("open_tun: %s: %s", tun_name, strerror(errno));
return -1;
}
fprintf(stderr, "Opened %s\n", tun_name);
return tun_fd;
} else {
for (i = 0; i < TUN_MAX_TRY; i++) {
snprintf(tun_name, sizeof(tun_name), "/dev/tun%d", i);
if ((tun_fd = open(tun_name, O_RDWR)) >= 0) {
fprintf(stderr, "Opened %s\n", tun_name);
snprintf(if_name, sizeof(if_name), "tun%d", i);
return tun_fd;
}
if (errno == ENOENT)
break;
}
warn("open_tun: Failed to open tunneling device");
}
return -1;
}
#endif /* !LINUX */
#else /* WINDOWS32 */
static void
get_device(char *device, int device_len, const char *wanted_dev)
{
LONG status;
HKEY adapter_key;
int index;
index = 0;
status = RegOpenKeyEx(HKEY_LOCAL_MACHINE, TAP_ADAPTER_KEY, 0, KEY_READ, &adapter_key);
if (status != ERROR_SUCCESS) {
warnx("Error opening registry key " TAP_ADAPTER_KEY );
return;
}
while (TRUE) {
char name[256];
char unit[256];
char component[256];
char cid_string[256] = KEY_COMPONENT_ID;
HKEY device_key;
DWORD datatype;
DWORD len;
/* Iterate through all adapter of this kind */
len = sizeof(name);
status = RegEnumKeyEx(adapter_key, index, name, &len, NULL, NULL, NULL, NULL);
if (status == ERROR_NO_MORE_ITEMS) {
break;
} else if (status != ERROR_SUCCESS) {
warnx("Error enumerating subkeys of registry key " TAP_ADAPTER_KEY );
break;
}
snprintf(unit, sizeof(unit), TAP_ADAPTER_KEY "\\%s", name);
status = RegOpenKeyEx(HKEY_LOCAL_MACHINE, unit, 0, KEY_READ, &device_key);
if (status != ERROR_SUCCESS) {
warnx("Error opening registry key %s", unit);
goto next;
}
/* Check component id */
len = sizeof(component);
status = RegQueryValueEx(device_key, cid_string, NULL, &datatype, (LPBYTE)component, &len);
if (status != ERROR_SUCCESS || datatype != REG_SZ) {
goto next;
}
if (strncmp(TAP_VERSION_ID_0801, component, strlen(TAP_VERSION_ID_0801)) == 0 ||
strncmp(TAP_VERSION_ID_0901, component, strlen(TAP_VERSION_ID_0901)) == 0) {
/* We found a TAP32 device, get its NetCfgInstanceId */
char iid_string[256] = NET_CFG_INST_ID;
status = RegQueryValueEx(device_key, iid_string, NULL, &datatype, (LPBYTE) device, (DWORD *) &device_len);
if (status != ERROR_SUCCESS || datatype != REG_SZ) {
warnx("Error reading registry key %s\\%s on TAP device", unit, iid_string);
} else {
/* Done getting GUID of TAP device,
* now check if the name is the requested one */
if (wanted_dev) {
char name[250];
get_name(name, sizeof(name), device);
if (strncmp(name, wanted_dev, strlen(wanted_dev))) {
/* Skip if name mismatch */
goto next;
}
}
/* Get the if name */
get_name(if_name, sizeof(if_name), device);
RegCloseKey(device_key);
return;
}
}
next:
RegCloseKey(device_key);
index++;
}
RegCloseKey(adapter_key);
}
static void
get_name(char *ifname, int namelen, char *dev_name)
{
char path[256];
char name_str[256] = "Name";
LONG status;
HKEY conn_key;
DWORD len;
DWORD datatype;
memset(ifname, 0, namelen);
snprintf(path, sizeof(path), NETWORK_KEY "\\%s\\Connection", dev_name);
status = RegOpenKeyEx(HKEY_LOCAL_MACHINE, path, 0, KEY_READ, &conn_key);
if (status != ERROR_SUCCESS) {
fprintf(stderr, "Could not look up name of interface %s: error opening key\n", dev_name);
RegCloseKey(conn_key);
return;
}
len = namelen;
status = RegQueryValueEx(conn_key, name_str, NULL, &datatype, (LPBYTE)ifname, &len);
if (status != ERROR_SUCCESS || datatype != REG_SZ) {
fprintf(stderr, "Could not look up name of interface %s: error reading value\n", dev_name);
RegCloseKey(conn_key);
return;
}
RegCloseKey(conn_key);
}
DWORD WINAPI tun_reader(LPVOID arg)
{
struct tun_data *tun = arg;
char buf[64*1024];
int len;
int res;
OVERLAPPED olpd;
int sock;
sock = open_dns(0, INADDR_ANY);
olpd.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
while(TRUE) {
olpd.Offset = 0;
olpd.OffsetHigh = 0;
res = ReadFile(tun->tun, buf, sizeof(buf), (LPDWORD) &len, &olpd);
if (!res) {
WaitForSingleObject(olpd.hEvent, INFINITE);
res = GetOverlappedResult(dev_handle, &olpd, (LPDWORD) &len, FALSE);
res = sendto(sock, buf, len, 0, (struct sockaddr*) &(tun->addr),
sizeof(struct sockaddr_in));
}
}
return 0;
}
int
open_tun(const char *tun_device)
{
char adapter[256];
char tapfile[512];
int tunfd;
in_addr_t local;
memset(adapter, 0, sizeof(adapter));
memset(if_name, 0, sizeof(if_name));
get_device(adapter, sizeof(adapter), tun_device);
if (strlen(adapter) == 0 || strlen(if_name) == 0) {
if (tun_device) {
warnx("No TAP adapters found. Try without -d.");
} else {
warnx("No TAP adapters found. Version 0801 and 0901 are supported.");
}
return -1;
}
fprintf(stderr, "Opening device %s\n", if_name);
snprintf(tapfile, sizeof(tapfile), "%s%s.tap", TAP_DEVICE_SPACE, adapter);
dev_handle = CreateFile(tapfile, GENERIC_WRITE | GENERIC_READ, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_SYSTEM | FILE_FLAG_OVERLAPPED, NULL);
if (dev_handle == INVALID_HANDLE_VALUE) {
warnx("Could not open device!");
return -1;
}
/* Use a UDP connection to forward packets from tun,
* so we can still use select() in main code.
* A thread does blocking reads on tun device and
* sends data as udp to this socket */
local = htonl(0x7f000001); /* 127.0.0.1 */
tunfd = open_dns(55353, local);
data.tun = dev_handle;
memset(&(data.addr), 0, sizeof(data.addr));
data.addr.sin_family = AF_INET;
data.addr.sin_port = htons(55353);
data.addr.sin_addr.s_addr = local;
CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)tun_reader, &data, 0, NULL);
return tunfd;
}
#endif
void
close_tun(int tun_fd)
{
if (tun_fd >= 0)
close(tun_fd);
}
int
write_tun(int tun_fd, char *data, size_t len)
{
#if defined (FREEBSD) || defined (DARWIN) || defined(NETBSD) || defined(WINDOWS32)
data += 4;
len -= 4;
#else /* !FREEBSD/DARWIN */
#ifdef LINUX
data[0] = 0x00;
data[1] = 0x00;
data[2] = 0x08;
data[3] = 0x00;
#else /* OPENBSD */
data[0] = 0x00;
data[1] = 0x00;
data[2] = 0x00;
data[3] = 0x02;
#endif /* !LINUX */
#endif /* FREEBSD */
#ifndef WINDOWS32
if (write(tun_fd, data, len) != len) {
warn("write_tun");
return 1;
}
#else /* WINDOWS32 */
{
DWORD written;
DWORD res;
OVERLAPPED olpd;
olpd.Offset = 0;
olpd.OffsetHigh = 0;
olpd.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
res = WriteFile(dev_handle, data, len, &written, &olpd);
if (!res && GetLastError() == ERROR_IO_PENDING) {
WaitForSingleObject(olpd.hEvent, INFINITE);
res = GetOverlappedResult(dev_handle, &olpd, &written, FALSE);
if (written != len) {
return -1;
}
}
}
#endif
return 0;
}
ssize_t
read_tun(int tun_fd, char *buf, size_t len)
{
#if defined (FREEBSD) || defined (DARWIN) || defined(NETBSD) || defined(WINDOWS32)
/* FreeBSD/Darwin/NetBSD has no header */
int bytes;
memset(buf, 0, 4);
#ifdef WINDOWS32
/* Windows needs recv() since it is local UDP socket */
bytes = recv(tun_fd, buf + 4, len - 4, 0);
#else
/* The other need read() because fd is not a socket */
bytes = read(tun_fd, buf + 4, len - 4);
#endif /*WINDOWS32*/
if (bytes < 0) {
return bytes;
} else {
return bytes + 4;
}
#else /* !FREEBSD */
return read(tun_fd, buf, len);
#endif /* !FREEBSD */
}
int
tun_setip(const char *ip, int netbits)
{
char cmdline[512];
int netmask;
struct in_addr net;
int i;
#ifndef LINUX
int r;
#endif
#ifdef WINDOWS32
DWORD status;
DWORD ipdata[3];
struct in_addr addr;
DWORD len;
#endif
netmask = 0;
for (i = 0; i < netbits; i++) {
netmask = (netmask << 1) | 1;
}
netmask <<= (32 - netbits);
net.s_addr = htonl(netmask);
if (inet_addr(ip) == INADDR_NONE) {
fprintf(stderr, "Invalid IP: %s!\n", ip);
return 1;
}
#ifndef WINDOWS32
snprintf(cmdline, sizeof(cmdline),
"/sbin/ifconfig %s %s %s netmask %s",
if_name,
ip,
ip,
inet_ntoa(net));
fprintf(stderr, "Setting IP of %s to %s\n", if_name, ip);
#ifndef LINUX
r = system(cmdline);
if(r != 0) {
return r;
} else {
snprintf(cmdline, sizeof(cmdline),
"/sbin/route add %s/%d %s",
ip, netbits, ip);
}
fprintf(stderr, "Adding route %s/%d to %s\n", ip, netbits, ip);
#endif
return system(cmdline);
#else /* WINDOWS32 */
/* Set device as connected */
fprintf(stderr, "Enabling interface '%s'\n", if_name);
status = 1;
r = DeviceIoControl(dev_handle, TAP_IOCTL_SET_MEDIA_STATUS, &status,
sizeof(status), &status, sizeof(status), &len, NULL);
if (!r) {
fprintf(stderr, "Failed to enable interface\n");
return -1;
}
if (inet_aton(ip, &addr)) {
ipdata[0] = (DWORD) addr.s_addr; /* local ip addr */
ipdata[1] = net.s_addr & ipdata[0]; /* network addr */
ipdata[2] = (DWORD) net.s_addr; /* netmask */
} else {
return -1;
}
/* Tell ip/networkaddr/netmask to device for arp use */
r = DeviceIoControl(dev_handle, TAP_IOCTL_CONFIG_TUN, &ipdata,
sizeof(ipdata), &ipdata, sizeof(ipdata), &len, NULL);
if (!r) {
fprintf(stderr, "Failed to set interface in TUN mode\n");
return -1;
}
/* use netsh to set ip address */
fprintf(stderr, "Setting IP of interface '%s' to %s (can take a few seconds)...\n", if_name, ip);
snprintf(cmdline, sizeof(cmdline), "netsh interface ip set address \"%s\" static %s %s",
if_name, ip, inet_ntoa(net));
return system(cmdline);
#endif
}
int
tun_setmtu(const unsigned mtu)
{
#ifndef WINDOWS32
char cmdline[512];
if (mtu > 200 && mtu <= 1500) {
snprintf(cmdline, sizeof(cmdline),
"/sbin/ifconfig %s mtu %u",
if_name,
mtu);
fprintf(stderr, "Setting MTU of %s to %u\n", if_name, mtu);
return system(cmdline);
} else {
warn("MTU out of range: %u\n", mtu);
}
return 1;
#else /* WINDOWS32 */
return 0;
#endif
}