RAS::AS5200.pm - PERL Interface to Cisco AS5200 Access Router
Version 1.04, June 9, 2000
RAS::AS5200 is a PERL 5 module for interfacing with a Cisco AS5200 access router. Using this module, one can very easily construct programs to find a particular user in a bank of AS5200s, disconnect users, get usage statistics, or execute arbitrary commands on a AS5200.
This module uses Jay Rogers' Net::Telnet module. If you don't have Net::Telnet, get it from CPAN or this module won't do much for you.
Installation is easy, thanks to MakeMaker:
"perl Makefile.PL && make"
"make test" to run the test suite. Check the test output. It should seem correct. If there are errors, check the hostname and passwords and try again.
If all is good, do a "make install"
Check out the examples in this documentation. Also, some programs based on the RAS:: series of modules will be made available on CPAN at the same place as this module.
At this time, the following methods are implemented:
Use the new() method to create a new object.
Example: use RAS::AS5200; $foo = new RAS::AS5200( hostname => 'dialup1.example.com', login => '!root', password => 'mysecret', truncateusernames => 'true' );
The following variables are useful: hostname - The hostname of the router to connect to login - The login name to get a command-line on the router password - The password to the login name supplied enablepassword - The enable password to the router truncateusernames - See below prompt - See below
Since there's no point in dynamically changing the hostname, login, etc. these settings are static and must be supplied to the constructor. No error will be returned if these settings are not specified (except for the hostname, which is required), but your program will likely not get very far without at least a hostname and a correct password. Some older IOS versions such as Version 11.2(15a) only require a password and not a login name -- if a login name is supplied, it is assumed that your router is not one of these and a full login-and-password script will be used; if a login name is not supplied, it is assumed that your router only requires a password to log in.
The enablepassword is only required if you'll be using commands that require enable status on the router. This includes the userkill() and killexcessoutoctets() methods and would also include, for example, run_command('reload').
If the "truncateusernames" option is set to non-null, then usernames supplied to user-seeking functions such as userkill() and usergrep() will be internally truncated to 10 characters. This is to work around a "feature" of the AS5200 that only the first 10 characters of a login name are displayed, which would cause usergrep('johnjjschmidt') to never work, as the AS5200 displays the login name as 'johnjjschm'. See the TRUNCATING USER NAMES section for more discussion on this.
Prompt handling has been vastly improved. If a prompt is not specified, a reasonable default is assumed that should work just fine. If you want to specify a prompt, supply a regular expression without delimiters or anchors that represents your router's prompt, e.g. prompt => 'as5200[>#]' If you get errors about a bad match operator or a bad delimiter, you likely specified anchros and/or delimiters.
This is for debugging. It prints to STDERR a list of its configuration hash, e.g. the hostname, login, and password. The printenv method does not return a value.
Example: $foo->printenv;
This takes a list of commands to be executed on the AS5200, executes the commands, and returns a list of references to arrays containg the text of each command's output. Repeat: It doesn't return an array, it returns an array of references to arrays. Each array contains the text output of each command. Think of it as an array-enhanced version of PERL's `backtick` operator.
Some router functions (e.g. rebooting) ask for confirmation - confirmation will be automatically supplied by the module's interface routine.
Example: # Execute a command and print the output $command = 'show modems'; ($x) = $foo->run_command($command); print "Output of command \'$command\':\n", @$x ; Example: # Execute a string of commands # and show the output from one of them (@output) = $foo->run_command('show isdn status','show modems'); print "Modems:\n@$output[0]\n\n";; print "Current connections:\n@$output[1]\n\n";;
In Cisco-land, some functions are only available in enabled mode. To specify that a command should be run in enabled mode, prefix the command with "ENABLE " - that's all caps and a single space between the ENABLE and the rest of the command.
Example: # Reboot the router $foo->run_command('ENABLE reload');
Supply a username as an argument, and usergrep will return an array of ports on which that user was found (thus, an empty list if they weren't found). An undefined value is returned if no username was supplied. Internally, this does a run_command('show users') and processes the output.
Example: @ports = $foo->usergrep('gregor'); print "User gregor was found on ports @ports\n";
This does a usergrep, but with a twist: it disconnects the user by resetting the modem on which they're connected. Like usergrep, it returns an array of ports to which the user was connected before they were reset (or an empty list if they weren't found). The undefined value is returned if no username is supplied.
Examples: @foo = $foo->userkill('gregor'); print "Gregor was on ports @foo - HA HA!\n" if @ports ; @duh = $foo->userkill('-'); print "There were ", scalar(@duh), " ports open.\n";
This returns an array: The 1st element is the number of ports. The rest is a list of users who are currently online.
Examples: ($ports,@people) = $foo->portusage; print "There are $ports total ports.\n"; print "There are ", scalar(@people), "people online.\n"; print "They are: @people\n"; ($ports,@people) = $foo->portusage; print "Ports free: ", $ports - scalar(@people), "\n"; print "Ports used: ", scalar(@people), "\n"; print "Ports total: ", $ports, "\n";
This returns a hash with the key of each item being a username. The value of each item is an array of the ports that that username is currently using. This provides some information that a simple usergrep() lacks.
Example: %userports = $foo->userports; foreach $user (keys(%userports)) { foreach $port (@{$userports{$user}}) { print "User: $user is on $port\n"; } }
Takes a bytelimit as an argument and then checks each port's out-octets count. If the out octet count is higher than the bytelimit, the interface and its counters are reset. This is useful to stop RADIUS counters from wrapping, since a 32-bit signed integer wraps into negative at about 2 gig.
Example: # kills users with outoctets of over about 2 gig $foo->killexcessoutoctets(2100000000);
These are some examples of how you could use this module. Full-fledged applications based on the RAS:: family of modules will be made available at CPAN at the same place as this module. Also, check out the test.pl file included in this distribution for some sample code.
###
portusage.pl - Prints a summary of port usage on a bank of modems use RAS::AS5200; $used = $total = 0; foreach ('dialup1.example.com','dialup2.example.com') { $foo = new RAS::AS5200( hostname => $_, login => '!root', password => 'mysecret' ); local($ports,@ports) = $foo->portusage; $total += $ports; $used += scalar(@ports); } print "$used out of $total ports are in use.\n";
usergrep.pl - Finds a user on a bank of modems ($username) = @ARGV; die "Usage: $0 <username>\nFinds the specified user.\n" unless $username ; use RAS::AS5200; foreach ('dialup1.example.com','dialup2.example.com') { $foo = new RAS::AS5200( hostname => $_, login => '!root', password => 'mysecret' ); @ports = $foo->usergrep($username); (@ports) && print "Found user $username on $_ ports @ports\n"; }
userkill.pl - Kick a user off a bank of modems. Makes a great cron job. ;) ($username) = @ARGV; die "Usage: $0 <username>\nDisconnects the specified user.\n" unless $username ; use RAS::AS5200; foreach ('dialup1.example.com','dialup2.example.com') { $foo = new RAS::AS5200( hostname => $_, login => '!root', password => 'mysecret' ); @ports = $foo->userkill($username); (@ports) && print "$_ : Killed ports @ports\n"; }
A "feature" of the Cisco AS5200 is that only the first 10 characters of login names are displayed. As such, doing a usergrep('johnjjschmidt') would never find the fellow, as the AS5200 truncates the username to 'johnjjschm'.
To work around this, you may set the "truncateusernames" flag in your constructor (see above). This will cause user-matching functions such as usergrep and userkill to internally truncate usernames to 10 characters for matching purposes. This means that usergrep('johnjjschmidt') would internally be treated as usergrep('johnjjschm') so that it would match.
So, you have your choice of two evils. If you don't enable username truncation, you'll miss users with login names over 10 characters in length. If you enable it, you could accidentally userkill user 'johnjjschm' when you meant to kill 'johnjjschmidt'. Sorry - Cisco screwed up and we get to suffer for it.
The set of functions supplied is a bit bare but is growing. If you write a useful function, or if you need a specific function added, please let me know and I'd be glad to check it out on an in-my-free-time basis.
There are no known bugs. There are likely a lot of unexpected features, though. If you find any, PLEASE let me know.
This module has been tested with an AS5300 with some degree of success. Last I heard, the userports() function didn't work properly on the AS5300.
1.04 Fixed some small typos.
1.03 Added the userports() and killexcessoutoctets() methods. Added better prompt support (YAY!). Made error messages more useful. Made the module work with or without a login prompt, as older IOS (11.2 specifically) doesn't require a login name, only a password.
1.02 Cleaned up the code substantially. Fixed a "bug" that truncated usernames at 8 characters. Added the "truncateusernames" option. Tested the userkill() function on ISDN clients - works.
1.01 Improved the error handling a tad. Touched up the docs.
1.00 First released version of RAS::AS5200.
RAS::AS5200 uses the Net::Telnet module by Jay Rogers <jay@rgrs.com> - thank you, Jay!
Gregor Mosheh <stigmata@blackangel.net> wrote RAS::AS5200 and left some significant problems in it, especially the prompt handling.
Luke Robins <luker@vicnet.net.au> worked on the prompt handling and apprised me that later IOSes need different login/password procedures, and he also wrote the userports() and killexcessoutoctets() methods.
Todd Caine <todd_caine@eli.net> helped out substantially with the prompt handling, as well.
Thank you very much, Luke and Robin, for fixing the most annoying bugs in RAS::AS5200!
The maintainer of RAS::AS5200 is Gregor Mosheh, at the address above.
Where would we be if Larry Wall were tight-fisted with PERL itself? For God's sake, it's PERL code. It's free!
This software is hereby released into the Public Domain, where it may be freely distributed, modified, plagiarized, used, abused, and deleted without regard for the original author.
Bug reports and feature requests will be handled ASAP, but without guarantee. The warranty is the same as for most freeware: It Works For Me, Your Mileage May Vary.
1 POD Error
The following errors were encountered while parsing the POD:
You forgot a '=back' before '=head1'
To install RAS::AS5200, copy and paste the appropriate command in to your terminal.
cpanm
cpanm RAS::AS5200
CPAN shell
perl -MCPAN -e shell install RAS::AS5200
For more information on module installation, please visit the detailed CPAN module installation guide.