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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. However, in this implementation, PPP is implemented as a user process with the help of tunnel device driver.
2 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.
2 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.
2 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.
2 o Can act as server which accept incoming PPP connection.
2 o Supports PAP and CHAP authentification.
2 o Supports packet filtering. User can define three kinds of filters; ifilter for incoming packet, ofilter for outgoing packet and dfilter to define dialing trigger packet.
2 o Tunnel driver supports bpf. That is, user can use tcpdump to check packet flow over the PPP link.
2 o Supports PPP over TCP capability.
2 o Supports IETF draft Predictor-1 compression.
2 o Runs under BSDI-1.1 and FreeBSD-1.1. Patch for NeXTSTEP 3.2 is also available on the net.
% ppp User Process PPP written by Toshiharu OHNO. -- You can specify modem and device name using following commands. ppp> set line /dev/cua01 ppp> set speed 38400 ppp> set parity even ppp> show modem -- Modem related parameters are shown in here ppp> -- Use term command to talk with your modem ppp> 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> PPP> -- NOW, you are get connected !! Note that prompt has changed to -- capital letters PPP> show lcp -- You'll see LCP status -- PPP> 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> add 0 0 HISADDR -- Here string `HISADDR' represents IP address of connected peer. PPP> -- Use applications (i.e. ping, telnet, ftp) in other windows PPP> show log -- Gives you some logging messages PPP> close -- Connection is closed, and modem will be hanged. ppp> 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>. % ppp pm2 ... ppp> dial dial OK! login OK! PPP> 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 ... PPP> show ipcp ....
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, another trigger packet cause dialing action. Note that automatic re-dialing is NOT implemented.
To terminate program, use PPP> close ppp> 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.
2 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.
2 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).
2 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) Prepare bidir entry in your /etc/gettytab bidir.38400:\ :bi:ap:hf:tc=38400-baud: b) Edit /etc/ttys to enable getty on the port where modem is attached. cua00 "/usr/libexec/getty stdir.38400" dialup on Don't forget to send HUP signal to init process. # kill -HUP 1 c) Prepare account for incoming user. ppp:*:21:0:PPP Login User:/home/ppp:/usr/local/bin/ppplogin d) Create /usr/local/bin/ppplogin file with next contents. #!/bin/sh /usr/local/bin/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> 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.
3 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.
3 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.
2 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.
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.
2 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
2 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.
2 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. Notes:
2 o As you may have already noticed, 192.244.177.2 is equivalent to say 192.244.177.2/32.
2 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.
2 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/example/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.[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.