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| Newer page: | version 3 | Last edited on Thursday, October 21, 2004 5:19:40 pm | by AristotlePagaltzis | Revert |
| Older page: | version 2 | Last edited on Friday, June 7, 2002 1:06:22 am | by perry | Revert |
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-
-
-
-call-back mini HOWTO
-
-
-
-----
-
-!!!call-back mini HOWTO
-
-!!by Pawel Skonecki,
-stona@kft.umcs.lublin.plv2.1a, 2001-10-06
-
-
-----
-''This document describes how to set up call-back by using the Linux
-system and modem. I would like to thank Anna for her patience.''
-----
-
-
-
-
-!!1. Introduction
-
-
-*1.1 OPINION
-
-*1.2 PUBLISHING
-
-
-
-
-
-!!2. Procedure
-
-
-*2.1 PART I: Net at home ?
-
-*2.2 PART II: The first steps with modem.
-
-*2.3 PART III Call Linux
-
-*2.4 PART IV Linux calls us
-
-*2.5 PART V Summary
-
-----
-
-!!1. Introduction
-
-!!1.1 OPINION
-
-
-
-I will be waiting for all opinions about this document. I have
-tried to gather information as complete as possible. Tell me when your
-find any mistakes. I'll be grateful to people who will send me any
-suggestions or corrections. Their contributions will make this
-document better. I don't mind answering your questions but I'd rather
-you read the whole article first.
-
-!!1.2 PUBLISHING
-
-
-
-This document can by published under the conditions of Linux Documentation
-Project. Get in touch with the author if you can't get this license.
-This document is free.
-
-
-
-----
-
-!!2. Procedure
-
-!!2.1 PART I: Net at home ?
-
-
-
-Most of us use the Internet in a place of work. However we offen need
-the net at home or outside the place of work. It may be possible that
-the work from home is cheaper then from a company building. I think
-that the best solution is to install call-back software on the Linux
-server. Call-back makes it possible to re-call index number at the
-cost of the company. I'll try to present how it works. An entitled
-person who calls the modem is varied for the first time in Linux server.
-Then on the user's side the "hang up modem" is switched on. At the same
-time Linux calls the user. User is verified again. We have connection
-and the server is charged. The user pays only for the initiation of the
-connection. The double verification and extra options in the call-back
-program unable the unsuitable persons to charge our bill. We can
-restrict the access to the connection only to corporation network or the
-Internet. Call-back is very flexible. Below, I'll try to present the
-configuration of a call-back server on Linux system and I'll show you
-how to set up your computer for re-calling the connection. I don't
-describe configuration of ISDN call-back because I don't use ISDN in
-my connection to the Internet. If you set call-back on ISDN send me
-your configuration.
-I had some problem when I changed my kernel from 2.2.x to 2.4.x. I will
-describe new option for a new kernel. Remember that if you change your
-kernel for high version you will have to change pppd, too.
-I don't create a new section for description of new possibility in kernels
-2.4.x but I write a new configurations in old section.
-I would like to apologise to people who asked me about options for new
-kernels.
-I didn't have time to write a new version of HOW-TO. I have changed my
-job and place of liveing. Sorry.
-
-
-
-
-!!2.2 PART II: The first steps with modem.
-
-
-
-The administrators prefer different modem but while buying a modem
-we should remember certain guidelines:
-
-
-
-
-
-*If you have USR !WinModems see Linmodem-HOWTO.
-
-*
-
-*The externale modem is moust flexible you have more place inste your computer.
-
-*
-
-*The internal modem with ISA slot is better then the are with PCI
-slot (you can use your PCI slot for something different )
-
-*
-
-*Don't use Plug modem see Plag-and-Play-HOWTO.
-
-*
-
-
-
-
-
-
-When we have the suitable modem we have to set it up in our system.
-We have to check on which com our modem is. Then we have to make a
-symbolic link to this hardware and /dev/modem. For example, if we have
-the modem for the 2nd com we write:
-
-ln -s /dev/cua1 /dev/modem
-
-
-
-We check it
-
-
-
-
-lrwxrwxrwx 1 root uucp 9 Sep 19 19:10 /dev/modem -> /dev/cua1
-
-
-
-If we have the modem on different com we have to remember that
-
-
-
-
-/dev/cua0 is com1
-/dev/cua1 is com2
-/dev/cua2 is com3
-/dev/cua3 is com4
-
-
-
-For new kernels:
-
-
-
-
-/dev/ttyS0 is com1
-/dev/ttyS1 is com2
-/dev/ttyS2 is com3
-/dev/ttyS3 is com4
-
-
-
-Now, we check our configuration using the program minicom.
-
-!!2.3 PART III Call Linux
-
-
-
-The first step to make the call-back on Linux accessible is to set up
-a suitable parameters in kernel. Then we check whether our kernel
-serves the protocol ppp. If you don't have ppp in your kernel or in
-module you will have to compile your kernel and add ppp. You will find
-more information in Kernel-HOWTO.In the kernels 2.4.x series you have to
-mark follow options:
-
-
-CONFIG_PPP=m
-# CONFIG_PPP_MULTILINK is not set
-CONFIG_PPP_ASYNC=m
-CONFIG_PPP_SYNC_TTY=m
-CONFIG_PPP_DEFLATE=m
-CONFIG_PPP_BSDCOMP=m
-
-
-After compilation you have to add some lines for /etc/modules.conf
-
-
-
-
-
-alias /dev/ppp ppp_generic
-alias char-major-108 ppp_generic
-alias tty-ldisc-3 ppp_async
-alias tty-ldisc-14 ppp_synctty
-alias ppp-compress-21 bsd_comp
-alias ppp-compress-24 ppp_deflate
-alias ppp-compress-26 ppp_deflate
-
-
-You can't forget that you need new pppd demon for kernels 2.4.x (for me
-it was ppp-2.4.0 this ppp has some mistake you have to get latest from ftp.samba.org in /pub/ppp
-).
-
-
-
-
-
-OK. We have a good kernel. Now, we have to set up the software to our system.
-The call-back program is a part of mgetty-sendfax and ppp. You will
-find it all in your distribution.
-Because the call-back system has double verification we create a
-user who will be running ppp on the side of server.
-In /etc/passwd you have new user and you have to change their shall.
-
-
-
-
-
-
-
-pppuser:klkIOM89mn65H:230:PPP Dialin:/home/pppuser:/etc/ppp/ppplogin
-
-
-
-I changed the above line for kernel 2.4.x this line in /etc/passwd (I use shadow
-and you don't see password)
-
-
-
-
-pppuser:x:6778:44:PPP Dialin:/etc/ppp/:/usr/sbin/pppd
-
-
-
-I don't use a special script for the running of pppd but I run it directly
-while login pppuser.
-
-
-Then change the password. We have to add information abut password in
-the file /etc/ppp/pap-secrets (more in man pppd)
-
-
-
-
-
-
-
-pppuser * password_for_pppuser *
-
-
-
-In the 2.4.x kernels you have to write in /etc/ppp/pap-secrets
-
-
-
-
-
-
-
-* * "" *
-
-
-
-This user doesn't have a usual shell but a file /etc/ppp/ppplogin.
-We have to make it ourselves. For example vi /etc/ppp/ppplogin and
-we type:
-
-
-
-
-#!/bin/sh
-exec /usr/sbin/pppd -detach 192.168.1.1:192.168.1.2
-
-
-
-where the address 192.168.1.1 is the address of server with modem and
-the address 192.168.1.2 is the address which we assigned to our modem.
-We set up executable options for this file. Because we will use the
-ppp demon we have to set up the options for this demon. We edit file
-/etc/ppp/options:
-
-
-
-
-proxyarp
-lock
-crtscts
-modem
-
-
-
-If it's 2.4.x kernel you write in /etc/ppp/options
-
-
-
-
--detach
-asyncmap
-modem
-crtscts
-proxyarp
-lock
-require-pap
-refuse-chap
-ms-dns 192.168.1.1
-usepeerdns
-
-
-
-The last 3rd option is very important. You use only PAP authentication
-,require-pap. Don't use chap authentication, refuse-chap.
-You can use ms-dns, If you have M$ Windows system clients you can send
-them information about DNS server. If you wont to send IP of DNS server
-for Linux/UNIX machine you use usepeerdns option, more in man pppd.
-
-
-
-
-
-Proxyarp is the most important from the above options, because you
-can go to Internet by the modem in the server. The remaining options
-are used to control your modem. You can only work on the server if you remove proxyarp option.
-You have to see PPP-HOWTO and man pppd for more information. We will set up our modem now.
-Our server must be ready to receive a connection after start.
-We edit file /etc/inittab
-and we add it's to modem on the 2en com.
-
-
-
-
-s1:2345:respawn:/sbin/mgetty ttyS1 -D /dev/ttyS1 vt100
-
-or
-
-s1:2345:respawn:/sbin/mgetty ttyS1 -s 115200 -D /dev/ttyS1
-
-
-
-For the 1st com line looks as follows:
-
-
-
-
-s0:2345:respawn:/sbin/mgetty ttyS1 -D /dev/ttyS1 vt100
-
-or
-
-s0:2345:respawn:/sbin/mgetty ttyS0 -s 115200 -D /dev/ttyS0
-
-We make init q. If we don't have information about any mistakes in
-logs we go to the next step. We come back to directory /etc/ppp and
-create options.ttyS1 (for modem com1 options.ttyS0)
-
-
-
-
-IP_local: IP_remote
-
-
-
-for our net it will be
-
-
-
-
-192.168.1.1:192.168.1.2
-
-
-
-We have done a lot work so far. Now, we check the file
-/etc/mgetty+sendfax/login.config. The most important line is:
-
-
-
-
-/AutoPPP/ - a_ppp /usr/sbin/pppd auth -chap +pap login detach 7 debug
-
-
-
-If you have 2.4.x kernel you have write in this file:
-
-/AutoPPP/ - a_ppp /usr/sbin/pppd file /etc/ppp/options
-
-The remaining lines can be marked #.
-
-
-
-
-
-We have to set up suid for ppp demon, because pppuser has to run pppd
-and make interface work.
-I insert have to insert opinion of Bill Staehle
-"NOTE: Some distributions think they know better than you, and delete this
-permission when their 'admin' tool (yast in SuSE, linuxconf in many others)
-is used. Read the documentation of the "tool" to see how to stop this crap."
-
-
-
-
-chmod u+s /usr/sbin/pppd
-
-
-
-and its effect is:
-
-
-
-
--rwsr-xr-x 1 root root 106892 Jan 11 1999 /usr/sbin/pppd
-
-
-
-I think that it is a good idea is to add it to cron becouse I had a
-problem after restart of my server pppd changed preference. It's
-normal situation in.
-I add opinion of Bill Staehle
-"COMMENT: This is what I was referring to. In Red Hat, look at
-/usr/lib/linuxconf/redhat/perm/ppp (delete or rename the file)."
-
-
-Our server will work as router. We have to enable IP forwarding and
-we add this line for the file /etc/rc.d/rc.local :
-
-
-
-
-echo "1" > /proc/sys/net/ipv4/ip_forward
-
-
-
-If you are !RedHat user you can change in /etc/sysconfig/network from
-FORWARD_IPV4=false to FORWARD_IPV4=true.
-
-
-
-
-
-For verification we call to Linux. We use scripts for it. If we do this in
-MS Windows we mark options "call out a terminal after connection".
-We login as pppuser with its password. I hope that all is OK.
-
-
-
-
-!!2.4 PART IV Linux calls us
-
-
-
-We can already call our Linux. Now it's time Linux called us. It's
-not very diffucalt. We have to edit only two files. We create a file
-/etc/mgetty+sendfax/callback.conf and we leave it empty.
-
-
-
-
-
-Then we have to ask our users for their phone number. It's time to
-write the numbers we have connected earlier. In order to do it we
-edit /etc/mgetty+sendfax/login.conf and add line:
-
-
-
-
-call - - /usr/sbin/callback -S 123456
-
-
-
-where call is a pseudo-user needed to initiate the connection. The
-line in the /etc/mgetty+sendfax/login.conf puts in motion the program
-calling the given number (in this case it's 123456). The same procedures
-can be applied to other users. I'll try to explain how it works. When
-we call a server. It asks us to give verification. We login as pseudo-user,
-in this case it calls. The script in our computer hangs up the modem.
-We wait and the connection is cut off. The program call-back starts
-working and recalls us. We verify ourselves again as pppuser with
-password. We combine the connection and interface ppp. That's all. The
-configuration of work-stations is very simple. When you have MS
-Windows, you have to install dial-up for your number. In the modem
-propriety we find " propriety--->extended---> extra options" where
-we write.
-
-
-
-
-&c0s0=1
-
-
-
-We close the window and call. We log in according to the description
-given above. If we want to use Linux, we must refer to the script.
-It's difficult to give only one good script for our Linux. A good
-configuration of ppp in the system is of primary importance. (You
-can call it as pppuser through the scripts first).The scripts below
-were whiten by A. Gozdz. I suggest putting everything to catalogue.
-It is only my suggestion & you don't have to start the scripts
here.
-Detailed information cocernig writing scripts on Linux can found in
-PPP-HOWTO.
-
-
-
-
-
-The configuration file of daemon ppp (an example for modem on com2)
-__THESE SCRIPTS WORK GOOD WITH LINUX RED HAT 6.x__
-
-
-
-
-
-*/etc/ppp/options
-
-lock
-defaultroute
-noipdefault
-modem
-115200
-crtscts
-debug
-passive
-asyncmap
-
-
-*
-
-*/etc/ppp/pppcallback
-
-TIMEOUT 5
-ABORT 'ERROR'
-ABORT 'BUSY'
-ABORT 'NO ANSWER'
-ABORT 'NO DIALTONE'
-ABORT '\nVOICE\r'
-ABORT '\nRINGING\r\n\r\nRINGING\r'
-'' AT&FH0 'OK-+++\c-OK' 'AT&C0S0=1'
-TIMEOUT 40
-OK ATDT5376443 CONNECT ''
-ogin:-ogin: ppp-pseudo-user
-'\nNO CARRIER\r' ''
-TIMEOUT 180
-'\nRING\r' AT&C1A
-CONNECT ''
-TIMEOUT 20
-ogin:-ogin: pppuser
-sword:-sword password_for_ppuser
-
-
-*
-
-*/usr/bin/ppp-call
-
-#!/bin/bash
-teksta="Connection failed"
-tekstb="Probably, You will be connect"
-# /sbin/setserial /dev/ttyS1 spd_vhi
-killall -INT pppd 2>/dev/null
-rm -f /var/lock/LCK* /var/run/ppp*.pid
-(/usr/sbin/pppd -detach call ppp_call &) || \
-(echo $teksta; ls marsss >/dev/null; exit 1)
-echo $tekstb
-exit
-
-
-*
-
-*You can run ppp-call, now. :)
-
-*
-
-
-
-
-
-
-If you have M$ Windows you can use this script for conection. I don't
-test it (I use terminal) you can ask some more Adrian Debkowski
-(
-adrian@cr-media.pl).
-
-
-
-
-proc main
-delay 1
-waitfor "ogin:"
-transmit "call^M"
-waitfor "RING"
-transmit "ATA^M"
-waitfor "CONNECT"
-waitfor "ogin:"
-transmit "pppuser^M"
-waitfor "word:"
-transmit "ppp^M"
-endproc
-
-
-
-
-
-!!2.5 PART V Summary
-
-
-
-The Configuration of call-back is not complicated. The most important
-thing is a proper arrangement of ppp server on Linux. I don't know a
-better way of setting up an access - server. The configuration
-presented above is a result of numerous attempts and it can be done in
-a different way. That's way I suggest reading all the documents concerning
-the issue man pppd, NET-HOWTO, PPP-HOWTO,ISP-Setup-!RedHat-HOWTO,Modem-HOWTO .
-A special thanks for Bill Staehle.
-----
+Describe [HowToCallback]
here.
