xref: /netbsd-src/external/bsd/ppp/dist/README (revision d16b7486a53dcb8072b60ec6fcb4373a2d0c27b7)
1This is the README file for ppp-2.4, a package which implements the
2Point-to-Point Protocol (PPP) to provide Internet connections over
3serial lines.
4
5
6Introduction.
7*************
8
9The Point-to-Point Protocol (PPP) provides a standard way to establish
10a network connection over a serial link.  At present, this package
11supports IP and IPV6 and the protocols layered above them, such as TCP
12and UDP.  The Linux port of this package also has support for IPX.
13
14This PPP implementation consists of two parts:
15
16- Kernel code, which establishes a network interface and passes
17packets between the serial port, the kernel networking code and the
18PPP daemon (pppd).  This code is implemented using STREAMS modules on
19Solaris, and as a line discipline under Linux.
20
21- The PPP daemon (pppd), which negotiates with the peer to establish
22the link and sets up the ppp network interface.  Pppd includes support
23for authentication, so you can control which other systems may make a
24PPP connection and what IP addresses they may use.
25
26The platforms supported by this package are Linux and Solaris.  I have
27code for NeXTStep, FreeBSD, SunOS 4.x, SVR4, Tru64 (Digital Unix), AIX
28and Ultrix but no active maintainers for these platforms.  Code for
29all of these except AIX is included in the ppp-2.3.11 release.
30
31The kernel code for Linux is no longer distributed with this package,
32since the relevant kernel code is in the official Linux kernel source
33(and has been for many years) and is included in all reasonably modern
34Linux distributions.  The Linux kernel code supports using PPP over
35things other than serial ports, such as PPP over Ethernet and PPP over
36ATM.
37
38
39Installation.
40*************
41
42The file SETUP contains general information about setting up your
43system for using PPP.  There is also a README file for each supported
44system, which contains more specific details for installing PPP on
45that system.  The supported systems, and the corresponding README
46files, are:
47
48	Linux				README.linux
49	Solaris				README.sol2
50
51In each case you start by running the ./configure script.  This works
52out which operating system you are using and creates the appropriate
53makefiles.  You then run `make' to compile the user-level code, and
54(as root) `make install' to install the user-level programs pppd, chat
55and pppstats.
56
57N.B. Since 2.3.0, leaving the permitted IP addresses column of the
58pap-secrets or chap-secrets file empty means that no addresses are
59permitted.  You need to put a "*" in that column to allow the peer to
60use any IP address.  (This only applies where the peer is
61authenticating itself to you, of course.)
62
63
64What's new in ppp-2.4.9.
65************************
66
67* Support for new EAP (Extensible Authentication Protocol) methods:
68  - Support for EAP-TLS, from Jan Just Keijser and others
69  - Support for EAP-MSCHAPv2, from Eivind Næss, Thomas Omerzu, Tijs
70    Van Buggenhout and others
71
72* New pppd options:
73  - chap-timeout
74  - chapms-strip-domain
75  - replacedefaultroute
76  - noreplacedefaultroute
77  - ipv6cp-accept-remote
78  - lcp-echo-adaptive
79  - ip-up-script
80  - ip-down-script
81  - ca
82  - capath
83  - cert
84  - key
85  - crl-dir
86  - crl
87  - max-tls-version
88  - need-peer-eap
89
90* Fixes for CVE-2020-8597 and CVE-2015-3310.
91
92* libpcap is now required when compiling on Linux (previously, if
93  libpcap was not present, pppd would be compiled without packet
94  filtering support).
95
96* The rp-pppoe plugin has been renamed to pppoe, to distinguish it
97  from the upstream rp-pppoe code.  Its options have changed names,
98  but the old names are kept as aliases.
99
100* The configure script now supports cross-compilation.
101
102* Many bug fixes and cleanups.
103
104
105What was new in ppp-2.4.8.
106**************************
107
108* New pppd options have been added:
109  - ifname, to set the name for the PPP interface device
110  - defaultroute-metric, to set the metric for the default route
111  - defaultroute6, to add an IPv6 default route (with nodefaultroute6
112    to prevent adding an IPv6 default route)
113  - up_sdnotify, to have pppd notify systemd when the link is up.
114
115* The rp-pppoe plugin has new options:
116  - host-uniq, to set the Host-Uniq value to send
117  - pppoe-padi-timeout, to set the timeout for discovery packets
118  - pppoe-padi-attempts, to set the number of discovery attempts.
119
120* Added the CLASS attribute in radius packets.
121
122* Sundry bug fixes.
123
124* Fixed warnings and issues found by static analysis.
125
126* Added Submitting-patches.md.
127
128
129What was new in ppp-2.4.7.
130**************************
131
132* Fixed a potential security issue in parsing option files (CVE-2014-3158).
133
134* There is a new "stop-bits" option, which takes an argument of 1 or 2,
135  indicating the number of stop bits to use for async serial ports.
136
137* Various bug fixes.
138
139
140What was new in ppp-2.4.6.
141**************************
142
143* Man page updates.
144
145* Several bug fixes.
146
147* Options files can now set and unset environment variables for
148  scripts.
149
150* The timeout for chat scripts can now be taken from an environment
151  variable.
152
153* There is a new option, master_detach, which allows pppd to detach
154  from the controlling terminal when it is the multilink bundle master
155  but its own link has terminated, even if the nodetach option has
156  been given.
157
158
159What was new in ppp-2.4.5.
160**************************
161
162* Under Linux, pppd can now operate in a mode where it doesn't request
163  the peer's IP address, as some peers refuse to supply an IP address.
164  Since Linux supports device routes as well as gateway routes, it's
165  possible to have no remote IP address assigned to the ppp interface
166  and still route traffic over it.
167
168* Pppd now works better with 3G modems that do strange things such as
169  sending IPCP Configure-Naks with the same values over and over again.
170
171* The PPP over L2TP plugin is included, which works with the pppol2tp
172  PPP channel code in the Linux kernel.  This allows pppd to be used
173  to set up tunnels using the Layer 2 Tunneling Protocol.
174
175* A new 'enable-session' option has been added, which enables session
176  accounting via PAM or wtwp/wtmpx, as appropriate.  See the pppd man
177  page for details.
178
179* Several bugs have been fixed.
180
181
182What was new in ppp-2.4.4.
183**************************
184
185* Pppd will now run /etc/ppp/ip-pre-up, if it exists, after creating
186  the ppp interface and configuring its IP addresses but before
187  bringing it up.  This can be used, for example, for adding firewall
188  rules for the interface.
189
190* Lots of bugs fixed, particularly in the area of demand-dialled and
191  persistent connections.
192
193* The rp-pppoe plugin now accepts any interface name (that isn't an
194  existing pppd option name) without putting "nic-" on the front of
195  it, not just eth*, nas*, tap* and br*.
196
197
198What was new in ppp-2.4.3.
199**************************
200
201* The configure script now accepts --prefix and --sysconfdir options.
202  These default to /usr/local and /etc.  If you want pppd put in
203  /usr/sbin as before, use ./configure --prefix=/usr.
204
205* Doing `make install' no longer puts example configuration files in
206  /etc/ppp.  Use `make install-etcppp' if you want that.
207
208* The code has been updated to work with version 0.8.3 of libpcap.
209  Unfortunately the libpcap maintainers removed support for the
210  "inbound" and "outbound" keywords on PPP links, meaning that if you
211  link pppd with libpcap-0.8.3, you can't use those keywords in the
212  active-filter and pass-filter expressions.  The support has been
213  reinstated in the CVS version and should be in future libpcap
214  releases.  If you need the in/outbound keywords, use a later release
215  than 0.8.3, or get the CVS version from http://www.tcpdump.org.
216
217* There is a new option, child-timeout, which sets the length of time
218  that pppd will wait for child processes (such as the command
219  specified with the pty option) to exit before exiting itself.  It
220  defaults to 5 seconds.  After the timeout, pppd will send a SIGTERM
221  to any remaining child processes and exit.  A value of 0 means no
222  timeout.
223
224* Various bugs have been fixed, including some CBCP packet parsing
225  bugs that could lead to the peer being able to crash pppd if CBCP
226  support is enabled.
227
228* Various fixes and enhancements to the radius and rp-pppoe plugins
229  have been added.
230
231* There is a new winbind plugin, from Andrew Bartlet of the Samba
232  team, which provides the ability to authenticate the peer against an
233  NT domain controller using MS-CHAP or MS-CHAPV2.
234
235* There is a new pppoatm plugin, by various authors, sent in by David
236  Woodhouse.
237
238* The multilink code has been substantially reworked.  The first pppd
239  for a bundle still controls the ppp interface, but it doesn't exit
240  until all the links in the bundle have terminated.  If the first
241  pppd is signalled to exit, it signals all the other pppds
242  controlling links in the bundle.
243
244* The TDB code has been updated to the latest version.  This should
245  eliminate the problem that some people have seen where the database
246  file (/var/run/pppd.tdb) keeps on growing.  Unfortunately, however,
247  the new code uses an incompatible database format.  For this reason,
248  pppd now uses /var/run/pppd2.tdb as the database filename.
249
250
251What was new in ppp-2.4.2.
252**************************
253
254* The CHAP code has been rewritten.  Pppd now has support for MS-CHAP
255  V1 and V2 authentication, both as server and client.  The new CHAP
256  code is cleaner than the old code and avoids some copyright problems
257  that existed in the old code.
258
259* MPPE (Microsoft Point-to-Point Encryption) support has been added,
260  although the current implementation shouldn't be considered
261  completely secure.  (There is no assurance that the current code
262  won't ever transmit an unencrypted packet.)
263
264* James Carlson's implementation of the Extensible Authentication
265  Protocol (EAP) has been added.
266
267* Support for the Encryption Control Protocol (ECP) has been added.
268
269* Some new plug-ins have been included:
270  - A plug-in for kernel-mode PPPoE (PPP over Ethernet)
271  - A plug-in for supplying the PAP password over a pipe from another
272    process
273  - A plug-in for authenticating using a Radius server.
274
275* Updates and bug-fixes for the Solaris port.
276
277* The CBCP (Call Back Control Protocol) code has been updated.  There
278  are new options `remotenumber' and `allow-number'.
279
280* Extra hooks for plugins to use have been added.
281
282* There is now a `maxoctets' option, which causes pppd to terminate
283  the link once the number of bytes passed on the link exceeds a given
284  value.
285
286* There are now options to control whether pppd can use the IPCP
287  IP-Address and IP-Addresses options: `ipcp-no-address' and
288  `ipcp-no-addresses'.
289
290* Fixed several bugs, including potential buffer overflows in chat.
291
292
293What was new in ppp-2.4.1.
294**************************
295
296* Pppd can now print out the set of options that are in effect.  The
297  new `dump' option causes pppd to print out the option values after
298  option parsing is complete.  The `dryrun' option causes pppd to
299  print the options and then exit.
300
301* The option parsing code has been fixed so that options in the
302  per-tty options file are parsed correctly, and don't override values
303  from the command line in most cases.
304
305* The plugin option now looks in /usr/lib/pppd/<pppd-version> (for
306  example, /usr/lib/pppd/2.4.1b1) for shared objects for plugins if
307  there is no slash in the plugin name.
308
309* When loading a plugin, pppd will now check the version of pppd for
310  which the plugin was compiled, and refuse to load it if it is
311  different to pppd's version string.  To enable this, the plugin
312  source needs to #include "pppd.h" and have a line saying:
313	char pppd_version[] = VERSION;
314
315* There is a bug in zlib, discovered by James Carlson, which can cause
316  kernel memory corruption if Deflate is used with the lowest setting,
317  8.  As a workaround pppd will now insist on using at least 9.
318
319* Pppd should compile on Solaris and SunOS again.
320
321* Pppd should now set the MTU correctly on demand-dialled interfaces.
322
323
324What was new in ppp-2.4.0.
325**************************
326
327* Multilink: this package now allows you to combine multiple serial
328  links into one logical link or `bundle', for increased bandwidth and
329  reduced latency.  This is currently only supported under the
330  2.4.x and later Linux kernels.
331
332* All the pppd processes running on a system now write information
333  into a common database.  I used the `tdb' code from samba for this.
334
335* New hooks have been added.
336
337For a list of the changes made during the 2.3 series releases of this
338package, see the Changes-2.3 file.
339
340
341Compression methods.
342********************
343
344This package supports two packet compression methods: Deflate and
345BSD-Compress.  Other compression methods which are in common use
346include Predictor, LZS, and MPPC.  These methods are not supported for
347two reasons - they are patent-encumbered, and they cause some packets
348to expand slightly, which pppd doesn't currently allow for.
349BSD-Compress and Deflate (which uses the same algorithm as gzip) don't
350ever expand packets.
351
352
353Contacts.
354*********
355
356The comp.protocols.ppp newsgroup is a useful place to get help if you
357have trouble getting your ppp connections to work.  Please do not send
358me questions of the form "please help me get connected to my ISP" -
359I'm sorry, but I simply do not have the time to answer all the
360questions like this that I get.
361
362If you find bugs in this package, please report them to the maintainer
363for the port for the operating system you are using:
364
365Linux			Paul Mackerras <paulus@samba.org>
366Solaris			James Carlson <carlson@workingcode.com>
367
368
369Copyrights:
370***********
371
372All of the code can be freely used and redistributed.  The individual
373source files each have their own copyright and permission notice.
374Pppd, pppstats and pppdump are under BSD-style notices.  Some of the
375pppd plugins are GPL'd.  Chat is public domain.
376
377
378Distribution:
379*************
380
381The primary site for releases of this software is:
382
383	ftp://ftp.samba.org/pub/ppp/
384
385
386