clash/proxy/redir/tcp_darwin.go

59 lines
1.6 KiB
Go

package redir
import (
"net"
"syscall"
"unsafe"
"github.com/Dreamacro/clash/component/socks5"
)
func parserPacket(c net.Conn) (socks5.Addr, error) {
const (
PfInout = 0
PfIn = 1
PfOut = 2
IOCOut = 0x40000000
IOCIn = 0x80000000
IOCInOut = IOCIn | IOCOut
IOCPARMMask = 0x1FFF
LEN = 4*16 + 4*4 + 4*1
// #define _IOC(inout,group,num,len) (inout | ((len & IOCPARMMask) << 16) | ((group) << 8) | (num))
// #define _IOWR(g,n,t) _IOC(IOCInOut, (g), (n), sizeof(t))
// #define DIOCNATLOOK _IOWR('D', 23, struct pfioc_natlook)
DIOCNATLOOK = IOCInOut | ((LEN & IOCPARMMask) << 16) | ('D' << 8) | 23
)
fd, err := syscall.Open("/dev/pf", 0, syscall.O_RDONLY)
if err != nil {
return nil, err
}
defer syscall.Close(fd)
nl := struct { // struct pfioc_natlook
saddr, daddr, rsaddr, rdaddr [16]byte
sxport, dxport, rsxport, rdxport [4]byte
af, proto, protoVariant, direction uint8
}{
af: syscall.AF_INET,
proto: syscall.IPPROTO_TCP,
direction: PfOut,
}
saddr := c.RemoteAddr().(*net.TCPAddr)
daddr := c.LocalAddr().(*net.TCPAddr)
copy(nl.saddr[:], saddr.IP)
copy(nl.daddr[:], daddr.IP)
nl.sxport[0], nl.sxport[1] = byte(saddr.Port>>8), byte(saddr.Port)
nl.dxport[0], nl.dxport[1] = byte(daddr.Port>>8), byte(daddr.Port)
if _, _, errno := syscall.Syscall(syscall.SYS_IOCTL, uintptr(fd), DIOCNATLOOK, uintptr(unsafe.Pointer(&nl))); errno != 0 {
return nil, errno
}
addr := make([]byte, 1+net.IPv4len+2)
addr[0] = socks5.AtypIPv4
copy(addr[1:1+net.IPv4len], nl.rdaddr[:4])
copy(addr[1+net.IPv4len:], nl.rdxport[:2])
return addr, nil
}