iodine/src/tun.c
Daniel Schaefer d2f671bdc7 Define searchpath for route with macro
Allows it to be easily overridden using the compiler commmandline.
Just like IFCONFIGPATH.
2019-08-24 16:43:34 +02:00

703 lines
16 KiB
C

/*
* Copyright (c) 2006-2014 Erik Ekman <yarrick@kryo.se>,
* 2006-2009 Bjorn Andersson <flex@kryo.se>
* 2013 Peter Sagerson <psagers.github@ignorare.net>
*
* Permission to use, copy, modify, and/or 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 DARWIN
#include <ctype.h>
#include <sys/kern_control.h>
#include <sys/sys_domain.h>
#include <sys/ioctl.h>
#include <net/if_utun.h>
#include <netinet/ip.h>
#endif
#ifndef IFCONFIGPATH
#define IFCONFIGPATH "PATH=/sbin:/bin "
#endif
#ifndef ROUTEPATH
#define ROUTEPATH "PATH=/sbin:/bin "
#endif
#ifdef WINDOWS32
#include "windows.h"
#include <winioctl.h>
static HANDLE dev_handle;
static 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 <netinet/in.h>
#include <arpa/inet.h>
#define TUN_MAX_TRY 50
#endif
#include "tun.h"
#include "common.h"
static char if_name[250];
#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;
#ifdef ANDROID
char *tunnel = "/dev/tun";
#else
char *tunnel = "/dev/net/tun";
#endif
if ((tun_fd = open(tunnel, O_RDWR)) < 0) {
warn("open_tun: %s", tunnel);
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);
fd_set_close_on_exec(tun_fd);
return tun_fd;
}
if (errno != EBUSY) {
warn("open_tun: ioctl[TUNSETIFF]");
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);
fd_set_close_on_exec(tun_fd);
return tun_fd;
}
if (errno != EBUSY) {
warn("open_tun: ioctl[TUNSETIFF]");
return -1;
}
}
warn("open_tun: Couldn't set interface name");
}
warn("error when opening tun");
return -1;
}
#elif 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_from_host("127.0.0.1", 0, AF_INET, 0);
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),
tun->addrlen);
}
}
return 0;
}
int
open_tun(const char *tun_device)
{
char adapter[256];
char tapfile[512];
int tunfd;
struct sockaddr_storage localsock;
int localsock_len;
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 */
localsock_len = get_addr("127.0.0.1", 55353, AF_INET, 0, &localsock);
tunfd = open_dns(&localsock, localsock_len);
data.tun = dev_handle;
memcpy(&(data.addr), &localsock, localsock_len);
data.addrlen = localsock_len;
CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)tun_reader, &data, 0, NULL);
return tunfd;
}
#else /* BSD and friends */
#ifdef DARWIN
/* Extract the device number from the name, if given. The value returned will
* be suitable for sockaddr_ctl.sc_unit, which means 0 for auto-assign, or
* (n + 1) for manual.
*/
static int
utun_unit(const char *dev)
{
const char *unit_str = dev;
int unit = 0;
while (*unit_str != '\0' && !isdigit(*unit_str))
unit_str++;
if (isdigit(*unit_str))
unit = strtol(unit_str, NULL, 10) + 1;
return unit;
}
static int
open_utun(const char *dev)
{
struct sockaddr_ctl addr;
struct ctl_info info;
char ifname[10];
socklen_t ifname_len = sizeof(ifname);
int fd = -1;
int err = 0;
fd = socket(PF_SYSTEM, SOCK_DGRAM, SYSPROTO_CONTROL);
if (fd < 0) {
warn("open_utun: socket(PF_SYSTEM)");
return -1;
}
/* Look up the kernel controller ID for utun devices. */
bzero(&info, sizeof(info));
strncpy(info.ctl_name, UTUN_CONTROL_NAME, MAX_KCTL_NAME);
err = ioctl(fd, CTLIOCGINFO, &info);
if (err != 0) {
warn("open_utun: ioctl(CTLIOCGINFO)");
close(fd);
return -1;
}
/* Connecting to the socket creates the utun device. */
addr.sc_len = sizeof(addr);
addr.sc_family = AF_SYSTEM;
addr.ss_sysaddr = AF_SYS_CONTROL;
addr.sc_id = info.ctl_id;
addr.sc_unit = utun_unit(dev);
err = connect(fd, (struct sockaddr *)&addr, sizeof(addr));
if (err != 0) {
warn("open_utun: connect");
close(fd);
return -1;
}
/* Retrieve the assigned interface name. */
err = getsockopt(fd, SYSPROTO_CONTROL, UTUN_OPT_IFNAME, ifname, &ifname_len);
if (err != 0) {
warn("open_utun: getsockopt(UTUN_OPT_IFNAME)");
close(fd);
return -1;
}
strncpy(if_name, ifname, sizeof(if_name));
fprintf(stderr, "Opened %s\n", ifname);
fd_set_close_on_exec(fd);
return fd;
}
#endif
int
open_tun(const char *tun_device)
{
int i;
int tun_fd;
char tun_name[50];
#ifdef DARWIN
if (!strncmp(tun_device, "utun", 4)) {
tun_fd = open_utun(tun_device);
if (tun_fd >= 0) {
return tun_fd;
}
}
#endif
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", tun_name);
return -1;
}
fprintf(stderr, "Opened %s\n", tun_name);
fd_set_close_on_exec(tun_fd);
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);
fd_set_close_on_exec(tun_fd);
return tun_fd;
}
if (errno == ENOENT)
break;
}
warn("open_tun: Failed to open tunneling device");
}
return -1;
}
#endif
void
close_tun(int tun_fd)
{
if (tun_fd >= 0)
close(tun_fd);
}
#ifdef WINDOWS32
int
write_tun(int tun_fd, char *data, size_t len)
{
DWORD written;
DWORD res;
OVERLAPPED olpd;
data += 4;
len -= 4;
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;
}
}
return 0;
}
ssize_t
read_tun(int tun_fd, char *buf, size_t len)
{
int bytes;
memset(buf, 0, 4);
bytes = recv(tun_fd, buf + 4, len - 4, 0);
if (bytes < 0) {
return bytes;
} else {
return bytes + 4;
}
}
#else
int
write_tun(int tun_fd, char *data, size_t len)
{
#if defined (FREEBSD) || defined (NETBSD)
/* FreeBSD/NetBSD has no header */
int header = 0;
#elif defined (DARWIN)
/* Darwin tun has no header, Darwin utun does */
int header = !strncmp(if_name, "utun", 4);
#else /* LINUX/OPENBSD */
int header = 1;
#endif
if (!header) {
data += 4;
len -= 4;
} else {
#ifdef LINUX
// Linux prefixes with 32 bits ethertype
// 0x0800 for IPv4, 0x86DD for IPv6
data[0] = 0x00;
data[1] = 0x00;
data[2] = 0x08;
data[3] = 0x00;
#else /* OPENBSD and DARWIN(utun) */
// BSDs prefix with 32 bits address family
// AF_INET for IPv4, AF_INET6 for IPv6
data[0] = 0x00;
data[1] = 0x00;
data[2] = 0x00;
data[3] = 0x02;
#endif
}
if (write(tun_fd, data, len) != len) {
warn("write_tun");
return 1;
}
return 0;
}
ssize_t
read_tun(int tun_fd, char *buf, size_t len)
{
#if defined (FREEBSD) || defined (NETBSD)
/* FreeBSD/NetBSD has no header */
int header = 0;
#elif defined (DARWIN)
/* Darwin tun has no header, Darwin utun does */
int header = !strncmp(if_name, "utun", 4);
#else /* LINUX/OPENBSD */
int header = 1;
#endif
if (!header) {
int bytes;
memset(buf, 0, 4);
bytes = read(tun_fd, buf + 4, len - 4);
if (bytes < 0) {
return bytes;
} else {
return bytes + 4;
}
} else {
return read(tun_fd, buf, len);
}
}
#endif
int
tun_setip(const char *ip, const char *other_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;
#else
const char *display_ip;
#ifndef LINUX
struct in_addr netip;
#endif
#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
# ifdef FREEBSD
display_ip = other_ip; /* FreeBSD wants other IP as second IP */
# else
display_ip = ip;
# endif
snprintf(cmdline, sizeof(cmdline),
IFCONFIGPATH "ifconfig %s %s %s netmask %s",
if_name,
ip,
display_ip,
inet_ntoa(net));
fprintf(stderr, "Setting IP of %s to %s\n", if_name, ip);
#ifndef LINUX
netip.s_addr = inet_addr(ip);
netip.s_addr = netip.s_addr & net.s_addr;
r = system(cmdline);
if(r != 0) {
return r;
} else {
snprintf(cmdline, sizeof(cmdline),
ROUTEPATH "route add %s/%d %s",
inet_ntoa(netip), netbits, ip);
}
fprintf(stderr, "Adding route %s/%d to %s\n", inet_ntoa(netip), 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),
IFCONFIGPATH "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
}