docs: networking: convert ipddp.txt to ReST

Not much to be done here:

- add SPDX header;
- use a document title from existing text;
- adjust a chapter markup;
- add to networking/index.rst.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 78 insertions, 0 deletions

diff --git a/Documentation/networking/ipddp.rst b/Documentation/networking/ipddp.rst
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+.. SPDX-License-Identifier: GPL-2.0
+
+=========================================================
+AppleTalk-IP Decapsulation and AppleTalk-IP Encapsulation
+=========================================================
+
+Documentation ipddp.c
+
+This file is written by Jay Schulist <jschlst@samba.org>
+
+Introduction
+------------
+
+AppleTalk-IP (IPDDP) is the method computers connected to AppleTalk
+networks can use to communicate via IP. AppleTalk-IP is simply IP datagrams
+inside AppleTalk packets.
+
+Through this driver you can either allow your Linux box to communicate
+IP over an AppleTalk network or you can provide IP gatewaying functions
+for your AppleTalk users.
+
+You can currently encapsulate or decapsulate AppleTalk-IP on LocalTalk,
+EtherTalk and PPPTalk. The only limit on the protocol is that of what
+kernel AppleTalk layer and drivers are available.
+
+Each mode requires its own user space software.
+
+Compiling AppleTalk-IP Decapsulation/Encapsulation
+==================================================
+
+AppleTalk-IP decapsulation needs to be compiled into your kernel. You
+will need to turn on AppleTalk-IP driver support. Then you will need to
+select ONE of the two options; IP to AppleTalk-IP encapsulation support or
+AppleTalk-IP to IP decapsulation support. If you compile the driver
+statically you will only be able to use the driver for the function you have
+enabled in the kernel. If you compile the driver as a module you can
+select what mode you want it to run in via a module loading param.
+ipddp_mode=1 for AppleTalk-IP encapsulation and ipddp_mode=2 for
+AppleTalk-IP to IP decapsulation.
+
+Basic instructions for user space tools
+=======================================
+
+I will briefly describe the operation of the tools, but you will
+need to consult the supporting documentation for each set of tools.
+
+Decapsulation - You will need to download a software package called
+MacGate. In this distribution there will be a tool called MacRoute
+which enables you to add routes to the kernel for your Macs by hand.
+Also the tool MacRegGateWay is included to register the
+proper IP Gateway and IP addresses for your machine. Included in this
+distribution is a patch to netatalk-1.4b2+asun2.0a17.2 (available from
+ftp.u.washington.edu/pub/user-supported/asun/) this patch is optional
+but it allows automatic adding and deleting of routes for Macs. (Handy
+for locations with large Mac installations)
+
+Encapsulation - You will need to download a software daemon called ipddpd.
+This software expects there to be an AppleTalk-IP gateway on the network.
+You will also need to add the proper routes to route your Linux box's IP
+traffic out the ipddp interface.
+
+Common Uses of ipddp.c
+----------------------
+Of course AppleTalk-IP decapsulation and encapsulation, but specifically
+decapsulation is being used most for connecting LocalTalk networks to
+IP networks. Although it has been used on EtherTalk networks to allow
+Macs that are only able to tunnel IP over EtherTalk.
+
+Encapsulation has been used to allow a Linux box stuck on a LocalTalk
+network to use IP. It should work equally well if you are stuck on an
+EtherTalk only network.
+
+Further Assistance
+-------------------
+You can contact me (Jay Schulist <jschlst@samba.org>) with any
+questions regarding decapsulation or encapsulation. Bradford W. Johnson
+<johns393@maroon.tc.umn.edu> originally wrote the ipddp.c driver for IP
+encapsulation in AppleTalk.