ppp: A C repository from Paul's PPP Package

This is the README file for ppp-2.5, a package which implements the
Point-to-Point Protocol (PPP) to provide Internet connections over
serial lines and other types of links which can be considered to be
point-to-point links.


Introduction.
*************

The Point-to-Point Protocol (PPP) provides a standard way to establish
a network connection over a serial link.  At present, this package
supports IP and IPV6 and the protocols layered above them, such as TCP
and UDP.

This PPP implementation consists of two parts:

- Kernel code, which establishes a network interface and passes
packets between the serial port, the kernel networking code and the
PPP daemon (pppd).  This code is implemented using STREAMS modules on
Solaris, and as a line discipline under Linux.

- The PPP daemon (pppd), which negotiates with the peer to establish
the link and sets up the ppp network interface.  Pppd includes support
for authentication, so you can control which other systems may make a
PPP connection and what IP addresses they may use.

The platforms supported by this package are Linux and Solaris.
(There is also code to support various old flavours of Unix in the git
repository, but it is quite old and unmaintained.)

The kernel code for Linux is no longer distributed with this package,
since the relevant kernel code is in the official Linux kernel source
(and has been for many years) and is included in all reasonably modern
Linux distributions.  The Linux kernel code supports using PPP over
things other than serial ports, such as PPP over Ethernet and PPP over
ATM.

Similarly, the kernel code for Solaris is no longer distributed with
this package.  See the Illumos web site for pointers to the kernel
module source code and build environment.

  https://www.illumos.org/


Installation.
*************

The file SETUP contains general information about setting up your
system for using PPP.  There is also a README file for each supported
system, which contains more specific details for installing PPP on
that system.  The supported systems, and the corresponding README
files, are:

	Linux				README.linux
	Solaris				README.sol2

In each case you start by running the ./configure script.  This works
out which operating system you are using and creates the appropriate
makefiles.  You then run `make' to compile the user-level code, and
(as root) `make install' to install the user-level programs pppd, chat
and pppstats.

N.B. Since 2.3.0, leaving the permitted IP addresses column of the
pap-secrets or chap-secrets file empty means that no addresses are
permitted.  You need to put a "*" in that column to allow the peer to
use any IP address.  (This only applies where the peer is
authenticating itself to you, of course.)


What's new in ppp-2.5.1
***********************

* The files copied to /etc/ppp (or <sysconfdir>/ppp) now have
  ".example" appended to their filenames, so as to indicate that they
  are just examples, and to avoid overwriting existing configuration
  files.

* Pppd can now measure and log the round-trip time (RTT) of LCP
  echo-requests and record them in a binary file structured as a
  circular buffer.  Other programs or scripts can examine the file and
  provide real-time statistics on link latency.  This is enabled by a
  new "lcp-rtt-file" option.

* New scripts net-init, net-pre-up and net-down are executed in the
  process of bringing the network interface up and down.  They provide
  additional, more deterministic ways for pppd to interact with the
  rest of the networking configuration.

* New options have been added to allow the system administrator to
  set the location of various scripts and secrets files.

* A new "noresolvconf" option tells pppd not to write the
  /etc/ppp/resolv.conf file; DNS server addresses, if obtained from
  the peer, are still passed to scripts in the environment.

* Pppd will now create the directory for the TDB connection database
  if it doesn't already exist.

* Kernel module code for Solaris is no longer included.

* Support for decompressing compressed packets has been removed from
  pppdump, because the zlib code used was old and potentially
  vulnerable.

* Some old code has been removed.

* Various other bug fixes and minor enhancements.


What was new in ppp-2.5.0.
**************************

The 2.5.0 release is a major release of pppd which contains breaking 
changes for third-party plugins, a complete revamp of the build-system
and that allows for flexibility of configuring features as needed.

In Summary:
* Support for PEAP authentication by Eivind Næss and Rustam Kovhaev
* Support for loading PKCS12 certificate envelopes 
* Adoption of GNU Autoconf / Automake build environment, by Eivind Næss
  and others.
* Support for pkgconfig tool has been added by Eivind Næss.
* Bunch of fixes and cleanup to PPPoE and IPv6 support by Pali Rohár.
* Major revision to PPPD's Plugin API by Eivind Næss.
  - Defines in which describes what features was included in pppd
  - Functions now prefixed with explicit ppp_* to indicate that
    pppd functions being called.
  - Header files were renamed to better align with their features,
    and now use proper include guards
  - A pppdconf.h file is supplied to allow third-party modules to use
    the same feature defines pppd was compiled with.
  - No extern declarations of internal variable names of pppd, 
    continued use of these extern variables are considered 
    unstable.
* Lots of internal fixes and cleanups for Radius and PPPoE by Jaco Kroon
* Dropped IPX support, as Linux has dropped support in version 5.15
  for this protocol.
* Many more fixes and cleanups.
* Pppd is no longer installed setuid-root.
* New pppd options:
  - ipv6cp-noremote, ipv6cp-nosend, ipv6cp-use-remotenumber,
    ipv6-up-script, ipv6-down-script
  - -v, show-options
  - usepeerwins, ipcp-no-address, ipcp-no-addresses, nosendip
* On Linux, any baud rate can be set on a serial port provided the
  kernel serial driver supports that.

Note that if you have built and installed previous versions of this
package and you want to continue having configuration and TDB files in
/etc/ppp, you will need to use the --sysconfdir option to ./configure.

For a list of the changes made during the 2.4 series releases of this
package, see the Changes-2.4 file.


Compression methods.
********************

This package supports two packet compression methods: Deflate and
BSD-Compress.  Other compression methods which are in common use
include Predictor, LZS, and MPPC.  These methods are not supported for
two reasons - they are patent-encumbered, and they cause some packets
to expand slightly, which pppd doesn't currently allow for.
BSD-Compress and Deflate (which uses the same algorithm as gzip) don't
ever expand packets.


Contacts.
*********

Most communication relating to this package happens on github at
https://github.com/ppp-project/ppp/.  The linux-ppp@vger.kernel.org
mailing list also exists and can be used.

If you find bugs in this package, the best thing to do is to create an
issue on github.  If you can't or don't want to do that, you can post
to linux-ppp@vger.kernel.org, or report them to the maintainer for the
port for the operating system you are using:

Linux			Paul Mackerras <paulus@ozlabs.org>
Solaris			James Carlson <carlsonj@workingcode.com>


Copyrights:
***********

All of the code can be freely used and redistributed.  The individual
source files each have their own copyright and permission notice.
Pppd, pppstats and pppdump are under BSD-style notices.  Some of the
pppd plugins are GPL'd.  Chat has an MIT licence notice.


Distribution:
*************

The primary site for releases of this software is:

	ftp://ftp.samba.org/pub/ppp/