$Id: ppp.8,v 1.4 1995/03/12 12:03:48 amurai Exp $
SH section heading
SS subsection heading
LP paragraph
IP indented paragraph
TP hanging label
This is user process PPP software package. Normally, PPP is implemented as a part of kernel and hard to debug and/or modify its behavior. (i.e. pppd) However, in this implementation, PPP is implemented as a user process with the help of tunnel device driver.
o Provide interactive user interface. Using its command mode, user can easily enter commands to establish the connection with the peer, check the status of connection, and close the connection. And now, all functions has password protected if describe your hostname/password in secret file or exist secret file itself.
o Supports both of manual and automatic dialing. Interactive mode has ``term'' command which enables you to talk to your modem directory. When your modem is connected to the peer, and it starts to speak PPP, PPP software detects it and turns into packet mode automatically. Once you have convinced how to connect with the peer, you can write chat script to define necessary dialing and login procedure for later convenience.
o Supports on-demand dialup capability. By using auto mode, PPP program will act as a daemon and wait for the packet send to the peer. Once packet is found, daemon automatically dials and establish the connection.
o Supports server mode by direct mode. Can act as server which accept incoming PPP connection.
o Supports PAP and CHAP authentification.
o Supports Proxy Arp. PPP is set up as server, you can also set up doing a proxy arp for your connection.
o Supports packet filtering. User can define four kinds of filters; ifilter for incoming packet, ofilter for outgoing packet, dfilter to define dialing trigger packet and afilter to keep alive a connection by trigger packet.
o Tunnel driver supports bpf. That is, user can use tcpdump to check packet flow over the PPP link.
o Supports PPP over TCP capability.
o Supports IETF draft Predictor-1 compression. PPP has a not only a VJ-compress but also Predictor-1 commpression. Normally a modem has a compression (i.e. v42.bis) and system should accept a high speed/expand date from modem. The Predictor-1 compression will compress whole packet data by system not like a VJ-compress. So it will reduce system overhead by SIO's interruption because of reducing data traffic between modem and SIO.
o Runs under BSDI-1.1 and FreeBSD-1.1. Patch for NeXTSTEP 3.2 is also available on the net.
When you run PPP, you might need to check and setup configuration. First your kernel should include a tunnel device. if not, you should re-config your kernel and re- build including follows line.
pseudo-device tun 1
Last word indicates a number of tunnel device as equivalent for number of PPP connection.
Second, check special(device) file for tunnel device named as /dev/tun0. If not, you can create by type "MAKEDEV tun0"
% ppp User Process PPP written by Toshiharu OHNO. -- If you write your hostname and password in ppp.secret, you can't do anything except quit and help command -- ppp on "your hostname"> help passwd : Password for manupilation quit : Quit PPP program help : Display this message ppp on tama> pass <password> -- "on" change to "ON" if you type correct password. ppp ON tama> -- You can specify modem and device name using following commands. ppp ON tama> set line /dev/cuaa0 ppp ON tama> set speed 38400 ppp ON tama> set parity even ppp ON tama> show modem -- Modem related parameters are shown in here ppp ON tama> -- Use term command to talk with your modem ppp ON tama> term at OK atdt123456 CONNECT login: ppp Password: -- PPP started in remote side --- -- When peer start to speak PPP, the program will detect it -- automatically and back to command mode. ppp ON tama> PPP ON TAMA> -- NOW, you are get connected !! Note that prompt has changed to -- capital letters PPP ON tama> show lcp -- You'll see LCP status -- PPP ON tama> show ipcp -- You'll see IPCP status -- -- At this point, your machine has host route to the peer. -- If your want to add default route entry, then enter PPP ON tama> add 0 0 HISADDR -- Here string `HISADDR' represents IP address of connected peer. PPP ON tama> -- Use applications (i.e. ping, telnet, ftp) in other windows PPP ON tama> show log -- Gives you some logging messages PPP ON tama> close -- Connection is closed, and modem will be hanged. ppp ON tama> quit %
To use automatic dialing, you must prepare Dial and Login chat script. See example definition found in ppp.conf.sample (Format of ppp.conf is pretty simple.)
2 o Each line contains one command, label or comment.
2 o Line stating with # is treated as a comment line.
2 o Label name has to start from first column and should be followed by colon (:).
2 o Command line must contains space or tab at first column.
If ppp.conf is ready, specify destination label name when you invoke ppp. Commands associated with destination label is executed when ppp command is invoked. Note that commands associated with ``default'' label is ALWAYS executed. Once connection is made, you'll find that prompt is changed to capital PPP on tama>. % ppp pm2 ... ppp ON tama> dial dial OK! login OK! PPP ON tama> If ppp.linkup file is available, its contents are executed when PPP link is connected. See example which add default route. The string HISADDR matches with IP address of connected peer.
To play with demand dialing, you must use -auto option. Also, you must specify destination label with proper setup in ppp.conf. It must contain ``ifaddr'' command to define peer's IP address. (refer /etc/ppp/ppp.conf.sample) % ppp -auto pm2demand ... %
When -auto is specified, PPP program works as a daemon. But, you are still able to use command features to check its behavior. % telnet localhost 3000 Trying 127.0.0.1... Connected to localhost.spec.co.jp. Escape character is '^]'. User Process PPP. Written by Toshiharu OHNO. Working as auto mode. PPP on tama> show ipcp what ? PPP on tama> pass xxxx PPP ON tama> show ipcp IPCP [OPEND] his side: xxxx ....
Each ppp has associated port number, which is computed as "3000 + tunnel_device_number". If 3000 is not good base number, edit defs.h. When packet toward to remote network is detected, PPP will take dialing action and try to connect with the peer. If dialing is failed, program will wait for 30 seconds. Once this hold time expired, It's re-dialing with previous trigger packets. To terminate program, type PPP ON tama> close ppp ON tama> quit all
Simple ``quit'' command will terminates telnet connection, but PPP program itself is not terminated. You must use ``quit all'' to terminate the program running as daemon.
This implementation supports packet filtering. There are three filters; ifilter, ofilter and dfilter. Here's some basics.
o Filter definition has next syntax. set filter-name rule-no action [src_addr/src_width] [dst_addr/dst_width] [proto [src [lt|eq|gt] port ] [dst [lt|eq|gt] port] [estab] a) filter-name should be ifilter, ofilter or dfiler. b) There are two actions permit and deny. If given packet is matched against the rule, action is taken immediately. c) src_width and dst_width works like a netmask to represent address range. d) proto must be one of icmp, udp or tcp.
o Each filter can hold upto 20 rules. Rule number starts from 0. Entire rule set is not effective until rule 0 is defined.
2 o If no rule is matched with a packet, that packet will be discarded (blocked).
o Use ``set filer-name -1'' to flush all rules.
See /etc/ppp/ppp.conf.filter.example
To receive incoming PPP connection request, follow next steps.
a) Make sure modem and /etc/rc.serial is setting up correctly. - Use HardWare Handshake (CTS/RTS) for flow controlling. - Modem should be setup NO echo back (ATE0) and No results string (ATQ1) b) Edit /etc/ttys to enable getty on the port where modem is attached. ttyd1 "/usr/libexec/getty std.38400" dialup on secure Don't forget to send HUP signal to init process. # kill -HUP 1 c) Prepare account for incoming user. ppp:xxxx:66:66:PPP Login User:/home/ppp:/usr/local/bin/ppplogin d) Create /usr/local/bin/ppplogin file with next contents. #!/bin/sh /usr/sbin/ppp -direct You can specify label name for further control.
Direct mode (-direct) lets PPP to work with standard in and out. Again, you can telnet to 3000 to get command mode control.
To check/set idletimer, use ``show timeout'' and ``set timeout'' command.
Ex. ppp ON tama> set timeout 600
Timeout period is measured in secs and default value is 180 or 3 min. To disable idle timer function, use ``set timeout 0''.
In -auto mode, idle timeout cause PPP session closed. However, PPP program itself is keep running. Another trigger packet cause dialing action.
This version supports CCP and Predictor type 1 compression based on current IETF-draft specs. As a default behavior, PPP will propose to use (or willing to accept) this capability and use it if peer agrees (or requests).
To disable CCP/predictor function completely, use ``disable pred'' and ``deny pred'' command.
PPP uses IPCP to negotiate IP addresses. Each side of node informs IP address that willing to use to the peer, and if requested IP address is acceptable, PPP returns ACK to requester. Otherwise, PPP returns NAK to suggest the peer to use different IP address. When both side of nodes agrees to accept the received request (and send ACK), IPCP is reached to open state and network level connection is established.
To control, this IPCP behavior, this implementation has ``set ifaddr'' to define MY and HIS IP address. ifaddr src_addr dst_addr
Where, src_addr is the IP address that my side is willing to use, and dst_addr is the IP address which his side should use.
ifaddr 192.244.177.38 192.244.177.2 For example, above specification means o I strongly want to use 192.244.177.38 as my side. I'll disagree when peer suggest me to use other addresses. o I strongly insists peer to use 192.244.177.2 as his side address. I don't permit him to use any IP address but 192.244.177.2. When peer request other IP address, I always suggest him to use 192.244.177.2. o This is all right, when each side has pre-determined IP address. However, it is often the case one side is acting as a server which controls IP address and the other side should obey the direction from him. In order to allow more flexible behavior, `ifaddr' command allows user to specify IP address more loosely. ifaddr 192.244.177.38/24 192.244.177.2/20 Number followed by slash (/) represents number of bits significant in IP address. That is, this example means o I'd like to use 192.244.177.38 as my side address, if it is possible. But I also accept any IP address between 192.244.177.0 and 192.244.177.255. o I'd like to make him to use 192.244.177.2 as his side address. But I also permit him to use any IP address between 192.244.176.0 and 192.244.191.255. o As you may have already noticed, 192.244.177.2 is equivalent to say 192.244.177.2/32. o As an exception, 0 is equivalent to 0.0.0.0/0. Means, I have no idea about IP address and obey what he says. o 192.244.177.2/0 means that I'll accept/permit any IP address but I'll try to insist to use 192.244.177.2 at first.
1) Describe provider's phone number in DialScript. Use ``set dial'' or ``set phone'' command. 2) Describle login procedure in LoginScript. Use ``set login'' command.
3) Use ``set ifaddr'' command to define IP address. o If you know what IP address provider uses, then use it as his address. o If provider has assigned particular IP address for you, then use it as my address. o If provider assigns your address dynamically, use 0 as my address. o If you have no info on IP addresses, then try set ifaddr 0 0
2 4) If provider request you to use PAP/CHAP auth method, add next lines into your ppp.conf.
3 enable pap (or enable chap)
3 disable chap (or disable pap)
3 set authname MyName
3 set authkey MyPassword
3
Please refer /etc/ppp/ppp.conf.iij for some real examples.
PPP is able to generate following level log info as /var/log/ppp.log
Phase Phase transition log output
Chat Generate Chat script trace log
LQM Generate LQR report
LCP Generate LCP/IPCP packet trace
HDLC Dump HDLC packet in hex
Async Dump async level packet in hex
``set debug'' command allows you to set logging output level, and multiple levels can be specified. Default is equivalent to ``set debug phase lcp''.
2 o Please read Japanese doc for complete explanation. Well, it is not useful for non-japanese readers, but examples in the document may help you to guess.
2 o Please read example configuration files.
2 o Use ``help'', ``show ?'' and ``set ?'' command.
2 o NetBSD and BSDI-1.0 has been supported in previous release, but no longer supported in this release. Please contact to author if you need old driver code.
PPP may refers three files, ppp.conf, ppp.linkup and ppp.secret. These files are placed in /etc/ppp, but user can create his own files under HOME directory as .ppp.conf,.ppp.linkup and .ppp.secret.the ppp always try to consult to user's personal setup first.
$HOME/ppp/.ppp.[conf|linkup|secret] User depend configuration files.
/etc/ppp/ppp.conf System default configuration file.
/etc/ppp/ppp.secret A authorization file for each system.
/etc/ppp/ppp.linkup A checking file when ppp establishes network level connection.
/var/log/ppp.log Logging and debug information file.
/var/spool/lock/Lck..* tty port locking file.