Some potential bindToDevice issues

[dyhkwong]

There may be some issues for bindToDevice but I did no further investigation.

• According to Microsoft documents and other proxy software, interface index should be a DWORD (uint32) in network byte order for IP_UNICAST_IF, and in host byte order for IPV6_UNICAST_IF.
  

  v2ray-core/transport/internet/sockopt_windows.go

  Lines 42 to 53 in 458db39

  	if config.BindToDevice != "" {
  	iface, err := net.InterfaceByName(config.BindToDevice)
  	if err != nil {
  	return newError("failed to get interface ", config.BindToDevice).Base(err)
  	}
  	if err := windows.SetsockoptInt(windows.Handle(fd), windows.IPPROTO_IP, IP_UNICAST_IF, iface.Index); err != nil {
  	return newError("failed to set IP_UNICAST_IF", err)
  	}
  	if err := windows.SetsockoptInt(windows.Handle(fd), windows.IPPROTO_IPV6, IPV6_UNICAST_IF, iface.Index); err != nil {
  	return newError("failed to set IPV6_UNICAST_IF", err)
  	}
  	}

• On Darwin and Windows, it tries to set both IP_(UNICAST|BOUND)_IF and IPV6_(UNICAST|BOUND)_IF for a single socket without ignoring expected errors. Normally only one of them should be set.
• On Windows, only applyOutboundSocketOptions calls bindToDevice. But on Darwin and Linux both applyOutboundSocketOptions and applyInboundSocketOptions call bindToDevice.

[grqz]

The binary patch below seems to fix the windows IP_UNICAST_IF issue.

IPS patch (xxd dump) for v2ray.exe unpacked from v2ray-windows-64.zip, v5.53.0

00:50 41 54 43 48    ; PATCH

05:4c 3e 32
08:00 14             ; size = 20

0a:48 8d 7c 24 30    ; lea rdi, [rsp+0x30]
0f:6a 1f             ; push 0x1f
11:59                ; pop rcx
12:8b 37             ; mov esi, dword [rdi]
14:0f ce             ; bswap esi
16:89 37             ; mov dword [rdi], esi
18:90                ; nop
19:e8 8c 04 00 00    ; call stub

1e:4c 42 d2          ; stub:
21:00 08             ; size = 8

23:6a 04             ; push 0x4
25:5e                ; pop rsi
26:e9 86 52 ff ff    ; jmp SetsockoptInt

2b:45 4f 46          ; END