basil00 8cdddce6ac Send an ICMP(V6) message if the packet is too big
Fix #278

The Miniport driver will reject any outbound
packet that is larger than the MTU.  However the
error flows back to the sending application as
an error code/condition, which is disrupted by
WinDivert, meaning the error is lost.

This change translates the error code into an
ICMP(V6) "packet too big" message, allowing for
the error to flow back to the origin in some
form.

This change required some refactoring.
2021-10-22 07:34:23 +08:00
2019-08-27 09:45:45 +08:00
2018-11-15 08:24:46 +08:00
2019-04-10 07:37:45 +08:00
2019-03-02 08:20:19 +08:00

WinDivert 2.2: Windows Packet Divert
====================================

1. Introduction
---------------

Windows Packet Divert (WinDivert) is a user-mode packet interception library
for Windows 7, Windows 8 and Windows 10.

WinDivert enables user-mode capturing/modifying/dropping of 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, sniffers,
firewalls, NATs, VPNs, IDSs, tunneling applications, etc..

WinDivert supports the following features:
    - 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 (LGPLv3)

For more information see doc/windivert.html

2. Architecture
---------------

The basic architecture of WinDivert is as follows:

                              +-----------------+
                              |                 |
                     +------->|    PROGRAM      |--------+
                     |        | (WinDivert.dll) |        |
                     |        +-----------------+        |
                     |                                   | (3) re-injected
                     | (2a) matching packet              |     packet
                     |                                   |
                     |                                   |
 [user mode]         |                                   |
 ....................|...................................|...................
 [kernel mode]       |                                   |
                     |                                   |
                     |                                   |
              +---------------+                          +----------------->
  (1) packet  |               | (2b) non-matching packet
 ------------>| WinDivert.sys |-------------------------------------------->
              |               |
              +---------------+

The WinDivert.sys driver is installed below the Windows network stack.  The
following actions occur:

(1) A new packet enters the network stack and is intercepted by WinDivert.sys
(2a) If the packet matches the PROGRAM-defined filter, it is diverted.  The
    PROGRAM can then read the packet using a call to WinDivertRecv().
(2b) If the packet does not match the filter, the packet continues as normal.
(3) PROGRAM either drops, modifies, or re-injects the packet.  PROGRAM can
    re-inject the (modified) using a call to WinDivertSend().

3. License
----------

WinDivert is dual-licensed under your choice of the GNU Lesser General Public
License (LGPL) Version 3 or the GNU General Public License (GPL) Version 2.
See the LICENSE file for more information.

4. About
--------

WinDivert was written by basil.

For further information, or bug reports, please contact:

    basil@reqrypt.org

The homepage for WinDivert is:

    https://reqrypt.org/windivert.html

The source code for WinDivert is hosted by GitHub at:

    https://github.com/basil00/Divert

2022-09-17 05:32:57 +03:00
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