Feature: add REDIRECT IPv6 support for FreeBSD. (#2768)

Upstream patch from FreeBSD ports which adds IPv6 support.
This commit is contained in:
Yonas Yanfa 2023-05-25 09:13:42 -04:00 committed by GitHub
parent ccd6d321cd
commit 2b6dd2a909
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 29 additions and 15 deletions

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@ -1,12 +1,16 @@
package redir
import (
"encoding/binary"
"errors"
"net"
"net/netip"
"syscall"
"unsafe"
"github.com/Dreamacro/clash/transport/socks5"
"golang.org/x/sys/unix"
)
const (
@ -25,28 +29,38 @@ func parserPacket(conn net.Conn) (socks5.Addr, error) {
return nil, err
}
var addr socks5.Addr
var addr netip.AddrPort
rc.Control(func(fd uintptr) {
addr, err = getorigdst(fd)
if ip4 := c.LocalAddr().(*net.TCPAddr).IP.To4(); ip4 != nil {
addr, err = getorigdst(fd)
} else {
addr, err = getorigdst6(fd)
}
})
return addr, err
return socks5.AddrFromStdAddrPort(addr), err
}
// Call getorigdst() from linux/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
func getorigdst(fd uintptr) (socks5.Addr, error) {
raw := syscall.RawSockaddrInet4{}
siz := unsafe.Sizeof(raw)
_, _, err := syscall.Syscall6(syscall.SYS_GETSOCKOPT, fd, syscall.IPPROTO_IP, SO_ORIGINAL_DST, uintptr(unsafe.Pointer(&raw)), uintptr(unsafe.Pointer(&siz)), 0)
func getorigdst(fd uintptr) (netip.AddrPort, error) {
addr := unix.RawSockaddrInet4{}
size := uint32(unsafe.Sizeof(addr))
_, _, err := syscall.Syscall6(syscall.SYS_GETSOCKOPT, fd, syscall.IPPROTO_IP, SO_ORIGINAL_DST, uintptr(unsafe.Pointer(&addr)), uintptr(unsafe.Pointer(&size)), 0)
if err != 0 {
return nil, err
return netip.AddrPort{}, err
}
addr := make([]byte, 1+net.IPv4len+2)
addr[0] = socks5.AtypIPv4
copy(addr[1:1+net.IPv4len], raw.Addr[:])
port := (*[2]byte)(unsafe.Pointer(&raw.Port)) // big-endian
addr[1+net.IPv4len], addr[1+net.IPv4len+1] = port[0], port[1]
return addr, nil
port := binary.BigEndian.Uint16((*(*[2]byte)(unsafe.Pointer(&addr.Port)))[:])
return netip.AddrPortFrom(netip.AddrFrom4(addr.Addr), port), nil
}
func getorigdst6(fd uintptr) (netip.AddrPort, error) {
addr := unix.RawSockaddrInet6{}
size := uint32(unsafe.Sizeof(addr))
_, _, err := syscall.Syscall6(syscall.SYS_GETSOCKOPT, fd, syscall.IPPROTO_IPV6, IP6T_SO_ORIGINAL_DST, uintptr(unsafe.Pointer(&addr)), uintptr(unsafe.Pointer(&size)), 0);
if err != 0 {
return netip.AddrPort{}, err
}
port := binary.BigEndian.Uint16((*(*[2]byte)(unsafe.Pointer(&addr.Port)))[:])
return netip.AddrPortFrom(netip.AddrFrom16(addr.Addr), port), nil
}