The Linux Alphanumeric Pager Gateway Mini-HOWTO by Chris Snell chris@unm.dorm.net http://www.unm.dorm.net/~chris +-----------------------------------------+ | The latest version of this document is | | always available at the Pager FTP site: | | ftp://ftp.unm.dorm.net/pub/paging | +-----------------------------------------+ PREFACE & DISCLAIMER: --------------------- This document sucks. I'm not a technical writer, nor do I plan to be one. I had a hard enough time pasing my English Composition class last semester. If anything, this document provides too much detail. If you have half a brain, some sendmail experience and some experience with modems, skim this thing. Otherwise, read on. If you blow up your computer/pager/modem or ruin your company network trying to set this up, go whine to your mother. Most likely, you won't mess up anything but I should warn you that sendmail is a tricky thing to play with and you will definitely be playing with it if you follow this document. PURPOSE: -------- This mini-HOWTO will describe how to set up an alphanumeric paging gateway on any linux machine. Your gateway will be able to send messages originating from both the World Wide Web and the Internet e-mail system to your alphanumeric pager. This is especially convienent, because no special skills are required for someone to send a message to your pager. All they must be able to do is use e-mail or the World Wide Web. **SPECIAL NOTE: ** This document does not cover the setup of paging gateways which are intended to send messages to non-alphanumeric (ie numbers-only) pagers or voice pagers. You'll need to look elsewhere for that information. REQUIREMENTS: ------------- - one or more alphanumeric pagers (see the ABOUT ALPHANUMERIC PAGERS section) - a machine running linux - a working modem (documentation reccomended!) - a telephone line - an Internet connection (if you wish to use the WWW interface and the net-wide e-mail interface) - compiler tools (gcc, make, etc. and some basic knowledge of their use.) - the sendmail electronic mail handler (you probably have this) - a working httpd (web server) if you want to create a WWW interface ABOUT ALPHANUMERIC PAGERS: -------------------------- Alphanumeric pagers are available from most reputable paging companies (and even some non-reputable ones ;-)). The prices range, but you should be able to pick up a good one for less than $200. I paid $180 for mine (and probably paid too much). Here are some things to look for when you go shopping for your pager: - Is this a name brand (ie. Motorola or the like) pager? - *MOST IMPORTANT* Does this pager support paging via a dialup line provided by your pager company? (See THE DIALUP PAGING LINE section) - Does it's memory have enough room for the pages you wish to recieve? - How reputable is the company? (See THE DIALUP PAGING LINE section) I don't work for any pager manufacturers but I wholeheartedly reccommend the Motorola line of pagers. I own one myself and will testify to their reliability and durability. In fact, mine has been dropped onto the concrete on many occaisions and did not sustain so much as a chipped case. You can find this line of pagers on Motorola's web site at: http://www.mot.com/MIMS/MSPG/Products/Alpha/ THE DIALUP PAGING LINE ---------------------- In order for your gateway to work, we need a way to deliver the messages to your paging company, which encodes them and transmits them over the air to your pager. This is done via a dialup (modem) connection with your paging company. Without this connection, you cannot setup a paging gateway. Therefore, it is very important that your paging company have such a dialup line. Unfortunately, many paging companies either do not have such a dialup line or do not know about the line they have. When inquiring with a paging company about this line, I found it helpful to ask if they could provide "computer software to send an alphanumeric page with". If they make available such software, you can bet that they make the dialup line availble that is necessary to use it. SPECIFICS ON THE DIALUP LINE ---------------------------- The dialup line is simply a modem on a remote computer (or possibly some kind of specialized box). The modem usually connects at 300-1200bps, although some (including my provider's) connect using v.22b at speeds up to 2400bps. Once the connection is made, your computer sends the page to the remote site by using a protocol known as TAP (formerly known as IXO). You do not need to know the details of this protocol, but if you are interested, check out the following document on my ftp site: ftp://pager.phys.unm.edu/pub/paging/ixo.txt HOW YOUR GATEWAY WILL WORK -------------------------- Before we proceed, I will provide a brief explanation of how the e-mail->pager gateway will work. The WWW gateway is similar and will be explained later. 1. A message intended for your pager is sent by someone via e-mail to a special address on your linux machine. 2. Your machine, using sendmail, accepts the message and routes it to a filter program, which strips the message of it's header and parses out important information like the sender's name and e-mail address and the subject of the message. This filter also strips the message of any .signature lines so that they do not clog your pager with unimportant information. 3. The paging filter passes the message onwards to the "sendpage" paging software which queues it for delivery. 4. Sendpage then dials your paging company's dialup line and (using TAP) sends the message. 5. Your paging company then beams the message to your pager over the radio waves. BEGINNING THE SETUP ------------------- The setup of the gateway will consist of four parts: - setting up sendpage - (optionally) getting a special DNS entry added for your paging gateway - setting up linux to handle multiple IP addresses - setting up sendmail to handle the message routing - setting up the World Wide Web interface GETTING THE SOFTWARE -------------------- Every peice of software necessary to set up this product can be obtained from my home site, ftp://pager.phys.unm.edu/pub/paging. I will try to keep these files current but will also list the alternate sites for the packages required. SENDPAGE SETUP -------------- Sendpage is the most important component of your paging gateway. To get anywhere in this project, you will need to obtain this software and compile it on your machine. The sendpage software can be obtained via ftp at: ftp://ftp.net.ohio-state.edu/pub/pagers/sendpage7a.tar.Z or from my machine: ftp://pager.phys.unm.edu/pub/paging/sendpage/sendpage7a.tar.Z Create a "paging" subdirectory somewhere. Fetch this software and unpack it (tar zxvf) in the paging directory. At this point, I would strongly suggest that you read over all the configuration information and README and INSTALL files in the sendpage package. However, you should probably ignore all the discussion on the setup of sendmail and instead rely on my procedure. Follow the instructions in the INSTALL file for compiling sendpage. Here are a few notes about the settings in the sendpage.h file which you will need to edit: - Make sure you have the "#define ARSYSTEM_NOTIFIER" line commented out (using "/*" and "*/") unless you own the commercial Remedy system monitor package. - Following the ARSYSTEM_NOTIFIER line, there are a few Linux (POSIX) specific lines that need to be defined: #define POSIX_SIGNALS #define POSIX_OPEN - For the modem definition, I recommend using: #define MODEM_DEV "/dev/modem" or "/dev/cua0" [com 1] or "/dev/cua1" [com 2] etc.... - For the modem init, I use the simple string and rely on NVRAM settings instead: #define MODEM_INIT ATEVXH - I use RTS/CTS flow control: #define C_FLAG CTRSCTS|HUPCL - and DTR toggle #define TOGGLE_DTR *** If you are interested, my sendpage.cf is available in it's entirety from my ftp site at: ftp://pager.phys.unm.edu/pub/paging/sendpage/sendpage.h.example CONFIGURING YOUR MODEM ---------------------- I use a ZyXEL 1496+ which seems to work fine with sendpage. With other modems, your milage may vary (possibly for the better). Although your paging company's modem (referred to by sendpage as "Paging Central") could very well be different from mine, you may want to try this setup to see if it works. You should have your modem manual handy as a reference for the proper init string. Here is what I have set: - Modem set to v.22bis 2400/1200 protocol (*no* auto-negotiate) - Serial port at 1200bps Your init string (sendpage.h) should already take care of: - Numeric (non-text) responses [these are a must!] ie: 0 for "OK" 5 for "CONNECT 1200" 7 for "BUSY" In order for sendpage to work, it must be able to access the modem. This requires read/write permissions to the modem device. On my system, sendpage is run set-uid to the username "sendpage". In my /etc/group file, I have a group called "modem" of which the user "sendpage" is a member. The device file for my modem (/dev/cua1) is owned by user "root" and group "modem". It is readable and writeable by both the owner and the group (chown root.modem /dev/cua1 ; chmod og+w /dev/cua1). SENDPAGE MAKEFILE SETUP ----------------------- Here are the build options I use for Linux: CC = gcc CFLAGS = -DLINUX -O2 -m486 -I/usr/include LIBS = -ldb -lbsd *** If you are interested, my Makefile is available in it's entirety from my ftp site at: ftp://pager.phys.unm.edu/pub/paging/sendpage/Makefile.example CONTINUING THE SETUP -------------------- Hopefully, you were able to get sendpage to compile correctly on the first try. Now you must set up sendpage for the initial testing. Following the INSTALL file's instructions, you will set up the queue directory and begin setting up the sendpage.cf file (I keep mine in /etc). A few notes on setting up the /etc/sendpage.cf: - I had to comment out (using "#") the entire trMap section for "bofh", leaving only the trMap section for "std" in order to get sendpage to work. - My "Global Options" section looks like: global maxMsgSize=480 maxMsgSplit=5 syslogFacility=LOG_MAIL\ timeFormat=dayFirst replyToSender=no\ emailFrom="sendpage@pager.phys.unm.edu (UNM Pager Gateway)" - My "Paging Central Definiton" section looks like: pc name=westlink phone=92437243 speed=1200 parity=even\ databits=7 stopbits=1 protocol=pet-pg1 msgretries=10\ answertime=25 modemdial=atdt dialer=internal\ modeminit=atevxh modemdev=/dev/cua1\ emailFrom="sendpage@pager.phys.unm.edu (UNM Pager Gateway)" - Here is my "Aliases" section. The 'chrisauto' definition does not send an e-mail reply when a page is sent and is used for hourly system stats that are sent to my page. alias chris 9246403.westlink alias chrisauto 9246403.westlink emailReply=no msgIncTime=yes alias nicolas 2515025.westlink - And finally, the "Profile" section: profile default emailReplyErr=yes emailReply=yes msgIncSender=yes\ msgIncDate=yes msgIncTime=yes profile numeric emailReplyErr=yes emailReply=yes msgIncSender=no\ msgIncDate=no msgIncTime=no set profile=default *** If you are interested, my sendpage.cf is available in it's entirety from my ftp site at: ftp://pager.phys.unm.edu/pub/paging/sendpage/sendpage.cf.example MOVING RIGHT ALONG... --------------------- Alright. At this point, I am assuming you have been able to at least send a page to your pager using sendpage's command-line interface. If you haven't been able to do this, re-read the INSTALL file and re-check your sendpage.h and sendpage.cf. If all else fails, subscribe to the IXO mailing list and ask there. SETTING UP A SPECIAL HOSTNAME ----------------------------- If you want to have a special virtual hostname for your paging gateway (ie. pager.yourcompany.com), there are a few steps that you will need to follow. If you do not want to (or cannot) set up an extra virtual hostname, skip ahead to the section entitiled "SETTING UP /etc/aliases". The first thing you need to do to set up your new hostname is to ask your network adminstrator to add a new ip address and hostname to the DNS tables. I would reccommend using the hostname "pager" but it really doesn't matter. Now that you have your new address and the associated IP number, you need to add it to your machine. This will be done in one of two ways, depending on the type of your linux distribution. * If you use the Linux kernel 1.2.xx series Get the IP aliasing patches from: ftp://pager.phys.unm.edu/pub/paging/ip_alias and follow the instructions in the file README.alias, substituting your newly-assigned IP address and gateway address for the ones mentioned in this README file. * If you are using Linux kernel 2.0.xx and above Enable the following options for your kernel and recompile: Network aliasing IP: aliasing support In your startup scripts (/etc/rc.d/rc.inet1 for Slackware users, /etc/sysconfig/network-scripts/ifup-eth for RedHat users) add the following lines: ifconfig eth0:0 191.59.16.224 route add -host 191.59.16.224 dev eth0:0 replacing 191.59.16.224 with your new IP address SETTING UP SENDMAIL ------------------- We need to make some aliases so that sendmail can distinguish between a message sent to you@somemachine.dink.com and you@pager.dink.com, when "somemachine" and "pager" are actually the same machine. To do this, we need to set up a sendmail alias database. The following information is based upon the info I got from http://www.qosina.com/~awm/apache/sendmail.html . *** Create a file, /etc/domainalias with translations from the pager hostname to the "real" hostname. On my machine (lonestar), my translation file looks like this: chris@pager.phys.unm.edu cjs-pager@lonestar.phys.unm.edu droux@pager.phys.unm.edu nicolas-pager@lonestar.phys.unm.edu That's it for that file. We are almost done now. I hope you have a sendmail binary that was compiled with the following switches: -DNDBM -DNEWDB These are to enable the database-handling code needed to read the domainalias.db file that we are about to create. *** Make sure that you have the makemap utility (part of the sendmail distribution). Compile it like this if you haven't already: ( This may not be neccessary, check to see if hash, dbm, or btree are supported or not, check next step on how to do this. ) # cd /usr/src/sendmail-8.7.x/makemap # rm Makefile makemap # make CFLAGS='-m486 -O2 -I../src -DNDBM -DNEWDB' LDFLAGS='-s -lgdbm -ldb' makemap # cp makemap /usr/bin *** Add a line to your /etc/sendmail.cf to make sendmail accept mail for the new virtual hostname: Cw pager.yourdomain.com *** Compile /etc/domainaliases into a database format: makemap btree domainaliases.db < domainalisaes *** Add another line to your /etc/sendmail.cf to tell sendmail about the domainaliases.db translation file which we just compiled. Kdomainaliases btree /etc/domainaliases.db *** Now for the rule-set, make sure you type it exactly into /etc/sendmail.cf The entries are seperated by a TAB field NOT SPACES!!!! These are to be inserted INSIDE the S98 Ruleset. PRE 8.7.1 R$+ < @ $+ . > $: $1 < @ $2 > . R$+ < @ $+ . > $* $: (domainaliases $1@$2 $: $1 < @ $2 > $3 $) R$+ < @ $+ . > $* $: (domainaliases $2 $: $1 < @ $2 > $3 $) R$+ < @ $+ > . $: $1 < @ $2 . > POST 8.7.1 R$+< $+. > $1< $2 > R$+< $+ > $: < > $(domainaliases $1$2 $) R< > $+ @ $* $: < $1 > $(domainaliases * @ $2 $) R< $+ > * $* $: < > $1 $2 R< > $* $: $>3 $1 *** Now you must kill your sendmail daemon and restart it for the new configurations to take effect. /sbin/killall sendmail sendmail -bd -q15m *** Finally, test your new configuration to make sure you did it correctly, Check /var/log/maillog for any possible error messages. lonestar~> sendmail -bt ADDRESS TEST MODE (ruleset 3 NOT automatically invoked) Enter
> 0 chris@pager.phys.unm.edu rewrite: ruleset 0 input: chris @ pager . phys . unm . edu rewrite: ruleset 98 input: chris @ pager . phys . unm . edu rewrite: ruleset 98 returns: chris @ pager . phys . unm . edu rewrite: ruleset 97 input: chris @ pager . phys . unm . edu rewrite: ruleset 3 input: chris @ pager . phys . unm . edu rewrite: ruleset 96 input: chris < @ pager . phys . unm . edu > rewrite: ruleset 96 returns: chris < @ pager . phys . unm . edu . > rewrite: ruleset 3 returns: chris < @ pager . phys . unm . edu . > rewrite: ruleset 0 input: chris < @ pager . phys . unm . edu . > rewrite: ruleset 98 input: chris < @ pager . phys . unm . edu . > rewrite: ruleset 3 input: cjs-pager @ lonestar . phys . unm . edu rewrite: ruleset 96 input: cjs-pager < @ lonestar . phys . unm . edu > rewrite: ruleset 96 returns: cjs-pager < @ lonestar . phys . unm . edu . > rewrite: ruleset 3 returns: cjs-pager < @ lonestar . phys . unm . edu . > rewrite: ruleset 98 returns: cjs-pager < @ lonestar . phys . unm . edu . > rewrite: ruleset 0 returns: $# local $: @ cjs-pager rewrite: ruleset 97 returns: $# local $: @ cjs-pager rewrite: ruleset 0 returns: $# local $: @ cjs-pager *** If this didn't work or you just don't understand, consult your local sendmail expert. SETTING UP /etc/aliases ----------------------- We're almost done. I swear. Now you need to set up your /etc/aliases file to handle the piping of the e-mail message to the filter which sends the message to sendpage. In the previous section, I demonstrated how I made chris@pager.phys.unm.edu point to cjs-pager@lonestar.phys.unm.edu. To make this work, I had to add a line to my /etc/aliases file to send all mail to cjs-pager to the filter. That line is: cjs-pager: "|/usr/local/bin/sendpagefilter chris" ^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^ This is the This is the full path to the This is a username that alias that paging filter. (see below) you defined in your you created sendpage.cf The filter used in this example can be obtained at: ftp://pager.phys.unm.edu/pub/paging/paging_filter.tar.gz Read the instructions in the included README file, compile the filter, and place it in a directory such as /usr/local/bin. You must now run the 'newaliases' command to process your new alias(es). With this complete, your paging gateway should be working. Try sending mail first to the alias which you created in /etc/aliases (in my example, cjs-pager). If this works, try sending mail to your virtual mail alias which you created in the previous section (in my example, chris@pager.phys.unm.edu). If this works, you are done!!! THE WWW GATEWAY --------------- I am not going to write much here. I'm assuming that you have some HTML skills and have used CGI scripts before. Your gateway will use a CGI script to communicate between the web browser and the sendpage program. I have made an example script and HTML page available: ftp://pager.phys.unm.edu/pub/paging/example_www_gateway.tar.gz This script utilizes two additonal programs, uncgi (to translate CGI data into shell environment variables for easy CGI programming) and d2utxt to strip out the ^M characters in a page message that make sendpage choke. These utilities are available in the same directory on the ftp site that the example HTML is found in. Read the instructions that come with them to compile them. This should be easy. For more help, look at my WWW gateway (http://pager.phys.unm.edu) to get an idea of how I did this. GETTING MORE HELP ----------------- The IXO mailing list To subscribe, send email to ixo-request@plts.org with the single word "subscribe" in the first line of an otherwise-blank message. The Sendpage mailing list To subscribe, issue this command from your unix prompt: echo 'subscribe' | Mail sendpage-hackers-request@lists.net.ohio-state.edu Me I'm a busy college student and employee so think three times before asking me for help. However, if you are a company and wish to hire me for consulting, I will be happy to talk with you. Chris Snell chris@unm.dorm.net chris@cs.unm.edu