WinDivert - Windows Packet Divert

Windows Packet Divert (WinDivert) is a user-mode packet capture-and-divert
package for Windows Vista, Windows 2008, Windows 7, Windows 8 and Windows 10.

WinDivert allows user-mode programs to capture/modify/drop network packets
sent to/from the Windows network stack.
In summary, WinDivert can
    - capture network packets
    - filter/drop network packets
    - sniff network packets
    - (re)inject network packets
    - modify network packets
WinDivert can be used to implement user-mode packet filters, packet sniffers,
firewalls, NAT, VPNs, tunneling applications, etc., etc..

The features of WinDivert include:
    - packet interception, sniffing, or dropping modes
    - support for loopback (localhost) traffic
    - full IPv6 support
    - network layer
    - simple yet powerful API
    - high-level filtering language
    - filter priorities
    - freely available under the terms of the GNU Lesser General Public
      License (LGPL)

Github Project