/
sockopt_freebsd.go
231 lines (209 loc) · 6.24 KB
/
sockopt_freebsd.go
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package internet
import (
"encoding/binary"
"net"
"os"
"syscall"
"unsafe"
"golang.org/x/sys/unix"
)
const (
sysPFINOUT = 0x0
sysPFIN = 0x1
sysPFOUT = 0x2
sysPFFWD = 0x3
sysDIOCNATLOOK = 0xc04c4417
)
type pfiocNatlook struct {
Saddr [16]byte /* pf_addr */
Daddr [16]byte /* pf_addr */
Rsaddr [16]byte /* pf_addr */
Rdaddr [16]byte /* pf_addr */
Sport uint16
Dport uint16
Rsport uint16
Rdport uint16
Af uint8
Proto uint8
Direction uint8
Pad [1]byte
}
const (
sizeofPfiocNatlook = 0x4c
soReUsePort = 0x00000200
soReUsePortLB = 0x00010000
)
func ioctl(s uintptr, ioc int, b []byte) error {
if _, _, errno := syscall.Syscall(syscall.SYS_IOCTL, s, uintptr(ioc), uintptr(unsafe.Pointer(&b[0]))); errno != 0 {
return error(errno)
}
return nil
}
func (nl *pfiocNatlook) rdPort() int {
return int(binary.BigEndian.Uint16((*[2]byte)(unsafe.Pointer(&nl.Rdport))[:]))
}
func (nl *pfiocNatlook) setPort(remote, local int) {
binary.BigEndian.PutUint16((*[2]byte)(unsafe.Pointer(&nl.Sport))[:], uint16(remote))
binary.BigEndian.PutUint16((*[2]byte)(unsafe.Pointer(&nl.Dport))[:], uint16(local))
}
// OriginalDst uses ioctl to read original destination from /dev/pf
func OriginalDst(la, ra net.Addr) (net.IP, int, error) {
f, err := os.Open("/dev/pf")
if err != nil {
return net.IP{}, -1, newError("failed to open device /dev/pf").Base(err)
}
defer f.Close()
fd := f.Fd()
b := make([]byte, sizeofPfiocNatlook)
nl := (*pfiocNatlook)(unsafe.Pointer(&b[0]))
var raIP, laIP net.IP
var raPort, laPort int
switch la.(type) {
case *net.TCPAddr:
raIP = ra.(*net.TCPAddr).IP
laIP = la.(*net.TCPAddr).IP
raPort = ra.(*net.TCPAddr).Port
laPort = la.(*net.TCPAddr).Port
nl.Proto = syscall.IPPROTO_TCP
case *net.UDPAddr:
raIP = ra.(*net.UDPAddr).IP
laIP = la.(*net.UDPAddr).IP
raPort = ra.(*net.UDPAddr).Port
laPort = la.(*net.UDPAddr).Port
nl.Proto = syscall.IPPROTO_UDP
}
if raIP.To4() != nil {
if laIP.IsUnspecified() {
laIP = net.ParseIP("127.0.0.1")
}
copy(nl.Saddr[:net.IPv4len], raIP.To4())
copy(nl.Daddr[:net.IPv4len], laIP.To4())
nl.Af = syscall.AF_INET
}
if raIP.To16() != nil && raIP.To4() == nil {
if laIP.IsUnspecified() {
laIP = net.ParseIP("::1")
}
copy(nl.Saddr[:], raIP)
copy(nl.Daddr[:], laIP)
nl.Af = syscall.AF_INET6
}
nl.setPort(raPort, laPort)
ioc := uintptr(sysDIOCNATLOOK)
for _, dir := range []byte{sysPFOUT, sysPFIN} {
nl.Direction = dir
err = ioctl(fd, int(ioc), b)
if err == nil || err != syscall.ENOENT {
break
}
}
if err != nil {
return net.IP{}, -1, os.NewSyscallError("ioctl", err)
}
odPort := nl.rdPort()
var odIP net.IP
switch nl.Af {
case syscall.AF_INET:
odIP = make(net.IP, net.IPv4len)
copy(odIP, nl.Rdaddr[:net.IPv4len])
case syscall.AF_INET6:
odIP = make(net.IP, net.IPv6len)
copy(odIP, nl.Rdaddr[:])
}
return odIP, odPort, nil
}
func applyOutboundSocketOptions(network string, address string, fd uintptr, config *SocketConfig) error {
if config.Mark != 0 {
if err := syscall.SetsockoptInt(int(fd), syscall.SOL_SOCKET, syscall.SO_USER_COOKIE, int(config.Mark)); err != nil {
return newError("failed to set SO_USER_COOKIE").Base(err)
}
}
if isTCPSocket(network) {
switch config.Tfo {
case SocketConfig_Enable:
if err := syscall.SetsockoptInt(int(fd), syscall.IPPROTO_TCP, unix.TCP_FASTOPEN, 1); err != nil {
return newError("failed to set TCP_FASTOPEN_CONNECT=1").Base(err)
}
case SocketConfig_Disable:
if err := syscall.SetsockoptInt(int(fd), syscall.IPPROTO_TCP, unix.TCP_FASTOPEN, 0); err != nil {
return newError("failed to set TCP_FASTOPEN_CONNECT=0").Base(err)
}
}
}
if config.Tproxy.IsEnabled() {
ip, _, _ := net.SplitHostPort(address)
if net.ParseIP(ip).To4() != nil {
if err := syscall.SetsockoptInt(int(fd), syscall.IPPROTO_IP, syscall.IP_BINDANY, 1); err != nil {
return newError("failed to set outbound IP_BINDANY").Base(err)
}
} else {
if err := syscall.SetsockoptInt(int(fd), syscall.IPPROTO_IPV6, syscall.IPV6_BINDANY, 1); err != nil {
return newError("failed to set outbound IPV6_BINDANY").Base(err)
}
}
}
return nil
}
func applyInboundSocketOptions(network string, fd uintptr, config *SocketConfig) error {
if config.Mark != 0 {
if err := syscall.SetsockoptInt(int(fd), syscall.SOL_SOCKET, syscall.SO_USER_COOKIE, int(config.Mark)); err != nil {
return newError("failed to set SO_USER_COOKIE").Base(err)
}
}
if isTCPSocket(network) {
switch config.Tfo {
case SocketConfig_Enable:
if err := syscall.SetsockoptInt(int(fd), syscall.IPPROTO_TCP, unix.TCP_FASTOPEN, int(config.TfoQueueLength)); err != nil {
return newError("failed to set TCP_FASTOPEN=", config.TfoQueueLength).Base(err)
}
case SocketConfig_Disable:
if err := syscall.SetsockoptInt(int(fd), syscall.IPPROTO_TCP, unix.TCP_FASTOPEN, 0); err != nil {
return newError("failed to set TCP_FASTOPEN=0").Base(err)
}
}
}
if config.Tproxy.IsEnabled() {
if err := syscall.SetsockoptInt(int(fd), syscall.IPPROTO_IPV6, syscall.IPV6_BINDANY, 1); err != nil {
if err := syscall.SetsockoptInt(int(fd), syscall.IPPROTO_IP, syscall.IP_BINDANY, 1); err != nil {
return newError("failed to set inbound IP_BINDANY").Base(err)
}
}
}
return nil
}
func bindAddr(fd uintptr, ip []byte, port uint32) error {
setReuseAddr(fd)
setReusePort(fd)
var sockaddr syscall.Sockaddr
switch len(ip) {
case net.IPv4len:
a4 := &syscall.SockaddrInet4{
Port: int(port),
}
copy(a4.Addr[:], ip)
sockaddr = a4
case net.IPv6len:
a6 := &syscall.SockaddrInet6{
Port: int(port),
}
copy(a6.Addr[:], ip)
sockaddr = a6
default:
return newError("unexpected length of ip")
}
return syscall.Bind(int(fd), sockaddr)
}
func setReuseAddr(fd uintptr) error {
if err := syscall.SetsockoptInt(int(fd), syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1); err != nil {
return newError("failed to set SO_REUSEADDR").Base(err).AtWarning()
}
return nil
}
func setReusePort(fd uintptr) error {
if err := syscall.SetsockoptInt(int(fd), syscall.SOL_SOCKET, soReUsePortLB, 1); err != nil {
if err := syscall.SetsockoptInt(int(fd), syscall.SOL_SOCKET, soReUsePort, 1); err != nil {
return newError("failed to set SO_REUSEPORT").Base(err).AtWarning()
}
}
return nil
}