IRC Defender was a malware/bot detector for IRC networks. This is deprecated, non-maintained and listed only for historical purposes. Do not run this in production!
Developed for irc.chatspike.net and the irc community
Lead Developer: Brain Contributors: WhiteWolf, openglx, reed and others Module Developers: ol, typobox43, Azhrarn Website Design: Craig
If you like this software, please drop us an email at [email protected] so that we can get a rough idea of how many users are using this program :-)
To use this program, your irc software must be listed in the table below. Support for other styles of ircd may be added on request however we may ask you for assistance in providing access to the said software so that we may develop a solution.
| irc server | Link module |
|---|---|
| UnrealIRCd 3.1.1 -> 3.2 | unreal |
| Bahamut 1.8.x | bahamut |
| UltimateIRCd 3.x | ultimate |
| Bahamut 1.4.x (unstable) | ultimate |
| Hybrid 7.x | hybrid |
| P10 (IRCu, beware ircd, etc.) | p10 |
| UnrealIRCd client mode (deprecated) | client |
| TR-IRCD | trircd |
| ptlink | ptlink6 |
| ircd 2.10 (RFC 2813) | ircd210 |
| InspIRCd Beta 6 to 1.0.7 | inspircd10 |
| InspIRCd 1.1.0 Beta 2 onwards | inspircd11 |
Thanks to WhiteWolf for submitting the TR-IRCD module used in ircdefender, and thanks to openglx for his ptlink6 module, both of which are available for your use due to their hard work and support of this project. Also a Big thanks to laXity of irc.bongster.de for his support and access to an UltimateIRCd test server which was used to develop the bahamut/ultimate support module, and a big thanks also to beware who and reed who gave advice and code for the P10 link protocol (also thanks for writing such an easy-to-follow spec for what is a complex protocol!).
If you link to an InspIRCd server, you must define a tag for your defender server, for example:
If you link to a hybrid server, you will most likely need to create a shared {} block (equivalent to a U-line), for your server, for example:
shared { name = "defender.mynetwork.net"; };
This will allow the defender server to set global k-lines (which will be used whenever defender wishes to ban a host) Be sure to disable command rate limiting for the defender server, or the "status" command (see below) will be practically useless! Adding a can_flood in the auth {} block or increasing the limits should have the desired effect.
If you link to a p10-compatible server such as ircu, you must add u:lines to all your servers, for example:
U:defender.mynetwork.com:Defender:*
This will serve two purposes, firstly it allows your defender to perform modehacks (e.g. for the flood module etc) and global kills, and secondly it doubles as a Q:line, forbidding normal users from using the nick 'Defender'.
On an ircd2.10 server, glines and globops are emulated by irc defender, and restarts of the service will reset all emulated glines.
Certain server types feature what is known as a 'server numeric'. These are normally allocated to you by the network administration of the network you link your server to. Depending on the module you select you will have to define a line in your conf as follows:
numeric=<your allocated server numeric>
At present, only three of the four modules in this distribution make use of numerics, and the formats are as follows:
| module type | numeric format | example |
|---|---|---|
| unreal | integer number, 1..255 | 156 |
| p10 | two alphanumeric characters | QZ B5 f4 hE |
| trircd | integer number, 1..255 | 28 |
See the example config file for details of configuration. Start the program with "perl defender.pl"
The program will background, and auto join the channel you have defined where the commands given below are accepted. Please be sure to secure your channel (e.g. set +O on it) so that normal users may not access these commands!
The program is modular, therefore you must select the modules you wish to use before proceeding with running the program. There are two special types of module, protocol and log modules, which are special in the regard that you must ALWAYS have at least one of each loaded and running. The protocol module provides the interface to the irc network and the logging module provides the interface to writing logs by redirecting stdout to handlers or files.
Once you have defined these two files in your config you are able to pick other modules, see the config for an example. These modules perform the actual scanning operations on users as they connect or interact with the service.
While the program is running, you may edit its config file then do a remote rehash (e.g. via /rehash defender.*) to cause its configuration files to be re-read. When you do this any modules you have removed from the configuration will be unloaded, and any you have added will be freshly loaded. Any that remain unchanged will be re-initialised as though the bot was just reloaded by hand. It your server software does not support remote rehashing, then you may do this instead on the bot's control channel:
botnick rehash
which will have the same effect as a /rehash on servers which support it.
As with most modular programs, the load order of your modules is important. Each module in defender has a set of dependencies, and a set of features it provides, so that modules can safely depend on each other in a stable and reliable way. It is up to you to ensure your modules are loaded in the right order not to cause conflicts and are not loaded multiple times. For example, if module A depends on module B, you must ensure that B appears before A in your modules= line in the config. Modules are loaded in order entered into the config file, from left to right.
To list all loaded modules, and show the program uptime, simply type:
status
on it's control channel.
If you wish for (very) verbose output you may type:
status all
if you want the program to report verbose information for one module only you may do this by typing:
status [module-name]
where module-name is the name of a module which is loaded.
The following modules are included in the base distribution:
This module scans for anatoly/fyle drones, e.g. bots with nicks such as `|{{] which join and part large channels in search of people to spam infection urls to. It will ban them by heuristics, giving virus like gecos, nick and ident combinations a heavier weighting. The paranoia= score in the config indicates how sensitive this should be, you are STRONGLY recommended to leave it at the default of 7.
Supported commands: fyle scan [nick] [ident] [gecos]
Note that to make this module work you will require the words.txt file from the project page at http://www.sourceforge.net/projects/ircdefender/
The killchan module will deny users access to specified channels. To use the killchan module, use the following commands on the control channel:
killchan add [channel] [reason]
killchan list
killchan del [channel]
When a non-oper joins a blacklisted channel, they will be temporarily G-Lined (the default is for 30 minutes). If an oper joins the forbidden channel they will just be warned that the channel is blacklisted, so they dont accidentally tell any non-opers to join.
TIP: It is a GOOD idea to put a killchan on your defender control channel, if your ircd only supports the most basic of channel security features such as +i, +s and +k. This way, if a normal user splitrides into the control channel, gets invited by an oper by accident (or on purpose!) or obtains the key, the killchan setting will G-Line them as soon as they join, while still letting opers gain access to the pseudoclient. This will also protect the channel whenever defender is running even if for example services, GNUWorld or whatever enforces the channel security on your control channel is unavailable due to DoS or netsplit, so that while ever there is a pseudoclient to issue commands to, it will ALWAYS be inaccessible to non-opers.
This simple module replies with a server notice if the bot is messaged, asking users to refer to your support channel for help.
This module eliminates fizzer drones. It has no configuration options or commands.
This module allows you to send a notice to all users on your network which match a given regular expression pattern. For example, you could send a message to all AOL users, or to all users in finland, or to all users with broken idents (or even all users whose ident contains a number, the possibilities are huge!) The module supports one command:
re_notice [regexp] [message]
The regexp is not automatically anchored, so where required remember to use ^ and $ to anchor your regexp. (if you are unsure on the syntax of regular expressions, google is as good source of help as anything).
This module detects nickfloods. You must add a value to your config file as follows:
nickflood_limit=5
This will /KILL all users who exceed 5 nickchanges in 5 seconds. When a user is killed, a message is put onto the control channel to announce it.
This module prevents large-scale botnet flooding of channels on your network. It provides a layer of protection which a channel cannot disable accidentally or otherwise (however they can override any locks by setting chanserv modelocks). The module has three thresholds and an interval, which can be set in the config file as follows:
flood_log=5
flood_globops=10
flood_lock=15
flood_interval=5
The first value is how many joins and parts constitute logging to the channel. If a channel has this many joins and parts, it will be logged on the channel you designated as Defender's "home" channel, e.g.:
<Defender> Channel #test has had 6 joins/parts in the past 5 seconds, 10 triggers oper alert.
The second value, if exceeded, causes the service to put out a GLOBOPS similar to above except sent to all opers.
If the third value is exceeded, the channel is locked down with the modes +miCKc to prevent further flooding, and the lock is automatically undone after a minute.
The fourth value is the 'interval', e.g. how long to let the counters build up for. For example if you set this to 5, all the counters will be X joins/5 secs.
This module watches for oper-ups. It can only be run when your defender is running using a server protocol and not when your defender is operating as an opered client. It will also require you to U:Line the server on your network so that it can deoper clients. You must define a list of regexp nicknames in the file opernicks.conf (in the config directory), seperated by newlines. For example, \[Brain\] (remember to escape characters such as [ and !) Any users that oper up who's nicks do not match nicks in the config file will be de-opered by the service, providing a second level of security against:
- Users who try to add o:lines for themselves for example during trial links
- Admins who may try and add local oper status for their friends
- Containment of compromised boxes where o:lines are added by intruders
etc etc...
You might think that these situations can be limited if your selection process is strict enough, but why take the risk? :-)
This module blocks cgi:irc users from accessing your network without accessing it from an authorised site.
As of version 1.4.0 this module maintains a list of authorised CGI:IRC sites, each of which is a regexp which matches the sites hostname. Edit the config file cgiirc.conf, and place into the config file a list of regexps (one per line) which match the hostnames which are allowed to use CGI:IRC.
As of v1.3.6, this module will set a timed G-line (ten minutes) when it detects a cgi:irc client, to prevent hammering of the server and spamming of the control channel.
This module allows you to set regexp based akills on users based on nick, ident, host and gecos. Please see the comments in the module file for examples.
Supported commands:
regexp_akill add [hostmask] [reason]
regexp_akill del [hostmask]
regexp_akill list
As of v1.3.6, this module will set a timed G-line (ten minutes) when it matches a banned nick, host or GECOS to prevent hammering of the server and spamming of the control channel.
This module serves two purposes. Firstly it can maintain a version blacklist to stop blacklisted client versions from connecting to your network. You should create a tab-separated file in your data dir, formatted as follows:
regexp G ban-reason
regexp2 G ban-reason2
regexp3 W warning-1
The first field is a regexp. If the regexp matches the version of a connecting client (e.g. "mirc.+6..+") then an action will be taken. The action to be taken is represented by the second field, which can be a G or a W. placing a G in this field makes the module G-line the user, the third parameter being placed into the ban reason. Placing a W in this field makes the module warn the user via privmsg, notifying them so that they may fix the problem. In this case the text given in the third field is sent to the user as-is.
Bottler.+ G XDCC Looker bots are not allowed here!
mIRC.+5\.+Bey W You are running an insecure mirc version, please upgrade
mIRC.+3\.+ W Why are you running a 10 year old copy of mirc?
eggdrop.+ G NO BOTS!
x-chat\s2\.0\.5 W Insecure x-chat version, please upgrade asap
This module also supports simple surveying of client verisons, so that you can for example determine what number of users are using mIRC, or x-chat, or irssi.
As of v1.3.6, this module will set a timed G-line (ten minutes) when it detects a banned version response, to prevent hammering of the server and spamming of the control channel.
This module will monitor the connections per minute on all your servers and fire off an alert via GLOBOPS if the limit increases past an administrator defined level. You must add a line such as the following to your defender.conf:
conn_average_max=100
This indicates that if the connections per minute over the entire network increases past 100, the notice should be sent out.
The spammage module is new to 1.4.x, and will detect repeated lines in a channel, wether or not these lines actually come from seperate clients, or the same client. Once triggered, all clients which repeat this line will be G-lined for ten minutes.
Because this is relatively resource intensive, a channel must be monitored explicitly by issuing the 'monitor' command on the control channel. The valid commands are as follows:
spammage monitor [#channel] [threshold] [reason]
spammage unmonitor [#channel]
When a channel is being monitored, a line must be repeated [threshold] times before the protection is activated. Once the protection is activated, users sending the line as privmsg or notice will be glined with the given reason. Any user who types any other line resets the spam counter to zero. Note that this makes this module particularly effective against certain types of spambots, but weak against others. Use this module where you think it would have a noticable effect (e.g. where all the bots repeat the same phrase).
Parts of this software based on PotBot (a simple perl bot: http://potbot.lv6.net/)
You may contact the authors of this software at #Defender on irc.chatspike.net, or by the sourceforge project page at http://ircdefender.sourceforge.net/
GNU GENERAL PUBLIC LICENSE
Version 2, June 1991
Copyright (C) 1989, 1991 Free Software Foundation, Inc.
59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
Preamble
The licenses for most software are designed to take away your
freedom to share and change it. By contrast, the GNU General Public
License is intended to guarantee your freedom to share and change free
software--to make sure the software is free for all its users. This
General Public License applies to most of the Free Software
Foundation's software and to any other program whose authors commit to
using it. (Some other Free Software Foundation software is covered by
the GNU Library General Public License instead.) You can apply it to
your programs, too.
When we speak of free software, we are referring to freedom, not
price. Our General Public Licenses are designed to make sure that you
have the freedom to distribute copies of free software (and charge for
this service if you wish), that you receive source code or can get it
if you want it, that you can change the software or use pieces of it
in new free programs; and that you know you can do these things.
To protect your rights, we need to make restrictions that forbid
anyone to deny you these rights or to ask you to surrender the rights.
These restrictions translate to certain responsibilities for you if you
distribute copies of the software, or if you modify it.
For example, if you distribute copies of such a program, whether
gratis or for a fee, you must give the recipients all the rights that
you have. You must make sure that they, too, receive or can get the
source code. And you must show them these terms so they know their
rights.
We protect your rights with two steps: (1) copyright the software, and
(2) offer you this license which gives you legal permission to copy,
distribute and/or modify the software.
Also, for each author's protection and ours, we want to make certain
that everyone understands that there is no warranty for this free
software. If the software is modified by someone else and passed on, we
want its recipients to know that what they have is not the original, so
that any problems introduced by others will not reflect on the original
authors' reputations.
Finally, any free program is threatened constantly by software
patents. We wish to avoid the danger that redistributors of a free
program will individually obtain patent licenses, in effect making the
program proprietary. To prevent this, we have made it clear that any
patent must be licensed for everyone's free use or not licensed at all.
The precise terms and conditions for copying, distribution and
modification follow.
GNU GENERAL PUBLIC LICENSE
TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
0. This License applies to any program or other work which contains
a notice placed by the copyright holder saying it may be distributed
under the terms of this General Public License. The "Program", below,
refers to any such program or work, and a "work based on the Program"
means either the Program or any derivative work under copyright law:
that is to say, a work containing the Program or a portion of it,
either verbatim or with modifications and/or translated into another
language. (Hereinafter, translation is included without limitation in
the term "modification".) Each licensee is addressed as "you".
Activities other than copying, distribution and modification are not
covered by this License; they are outside its scope. The act of
running the Program is not restricted, and the output from the Program
is covered only if its contents constitute a work based on the
Program (independent of having been made by running the Program).
Whether that is true depends on what the Program does.
1. You may copy and distribute verbatim copies of the Program's
source code as you receive it, in any medium, provided that you
conspicuously and appropriately publish on each copy an appropriate
copyright notice and disclaimer of warranty; keep intact all the
notices that refer to this License and to the absence of any warranty;
and give any other recipients of the Program a copy of this License
along with the Program.
You may charge a fee for the physical act of transferring a copy, and
you may at your option offer warranty protection in exchange for a fee.
2. You may modify your copy or copies of the Program or any portion
of it, thus forming a work based on the Program, and copy and
distribute such modifications or work under the terms of Section 1
above, provided that you also meet all of these conditions:
a) You must cause the modified files to carry prominent notices
stating that you changed the files and the date of any change.
b) You must cause any work that you distribute or publish, that in
whole or in part contains or is derived from the Program or any
part thereof, to be licensed as a whole at no charge to all third
parties under the terms of this License.
c) If the modified program normally reads commands interactively
when run, you must cause it, when started running for such
interactive use in the most ordinary way, to print or display an
announcement including an appropriate copyright notice and a
notice that there is no warranty (or else, saying that you provide
a warranty) and that users may redistribute the program under
these conditions, and telling the user how to view a copy of this
License. (Exception: if the Program itself is interactive but
does not normally print such an announcement, your work based on
the Program is not required to print an announcement.)
These requirements apply to the modified work as a whole. If
identifiable sections of that work are not derived from the Program,
and can be reasonably considered independent and separate works in
themselves, then this License, and its terms, do not apply to those
sections when you distribute them as separate works. But when you
distribute the same sections as part of a whole which is a work based
on the Program, the distribution of the whole must be on the terms of
this License, whose permissions for other licensees extend to the
entire whole, and thus to each and every part regardless of who wrote it.
Thus, it is not the intent of this section to claim rights or contest
your rights to work written entirely by you; rather, the intent is to
exercise the right to control the distribution of derivative or
collective works based on the Program.
In addition, mere aggregation of another work not based on the Program
with the Program (or with a work based on the Program) on a volume of
a storage or distribution medium does not bring the other work under
the scope of this License.
3. You may copy and distribute the Program (or a work based on it,
under Section 2) in object code or executable form under the terms of
Sections 1 and 2 above provided that you also do one of the following:
a) Accompany it with the complete corresponding machine-readable
source code, which must be distributed under the terms of Sections
1 and 2 above on a medium customarily used for software interchange; or,
b) Accompany it with a written offer, valid for at least three
years, to give any third party, for a charge no more than your
cost of physically performing source distribution, a complete
machine-readable copy of the corresponding source code, to be
distributed under the terms of Sections 1 and 2 above on a medium
customarily used for software interchange; or,
c) Accompany it with the information you received as to the offer
to distribute corresponding source code. (This alternative is
allowed only for noncommercial distribution and only if you
received the program in object code or executable form with such
an offer, in accord with Subsection b above.)
The source code for a work means the preferred form of the work for
making modifications to it. For an executable work, complete source
code means all the source code for all modules it contains, plus any
associated interface definition files, plus the scripts used to
control compilation and installation of the executable. However, as a
special exception, the source code distributed need not include
anything that is normally distributed (in either source or binary
form) with the major components (compiler, kernel, and so on) of the
operating system on which the executable runs, unless that component
itself accompanies the executable.
If distribution of executable or object code is made by offering
access to copy from a designated place, then offering equivalent
access to copy the source code from the same place counts as
distribution of the source code, even though third parties are not
compelled to copy the source along with the object code.
4. You may not copy, modify, sublicense, or distribute the Program
except as expressly provided under this License. Any attempt
otherwise to copy, modify, sublicense or distribute the Program is
void, and will automatically terminate your rights under this License.
However, parties who have received copies, or rights, from you under
this License will not have their licenses terminated so long as such
parties remain in full compliance.
5. You are not required to accept this License, since you have not
signed it. However, nothing else grants you permission to modify or
distribute the Program or its derivative works. These actions are
prohibited by law if you do not accept this License. Therefore, by
modifying or distributing the Program (or any work based on the
Program), you indicate your acceptance of this License to do so, and
all its terms and conditions for copying, distributing or modifying
the Program or works based on it.
6. Each time you redistribute the Program (or any work based on the
Program), the recipient automatically receives a license from the
original licensor to copy, distribute or modify the Program subject to
these terms and conditions. You may not impose any further
restrictions on the recipients' exercise of the rights granted herein.
You are not responsible for enforcing compliance by third parties to
this License.
7. If, as a consequence of a court judgment or allegation of patent
infringement or for any other reason (not limited to patent issues),
conditions are imposed on you (whether by court order, agreement or
otherwise) that contradict the conditions of this License, they do not
excuse you from the conditions of this License. If you cannot
distribute so as to satisfy simultaneously your obligations under this
License and any other pertinent obligations, then as a consequence you
may not distribute the Program at all. For example, if a patent
license would not permit royalty-free redistribution of the Program by
all those who receive copies directly or indirectly through you, then
the only way you could satisfy both it and this License would be to
refrain entirely from distribution of the Program.
If any portion of this section is held invalid or unenforceable under
any particular circumstance, the balance of the section is intended to
apply and the section as a whole is intended to apply in other
circumstances.
It is not the purpose of this section to induce you to infringe any
patents or other property right claims or to contest validity of any
such claims; this section has the sole purpose of protecting the
integrity of the free software distribution system, which is
implemented by public license practices. Many people have made
generous contributions to the wide range of software distributed
through that system in reliance on consistent application of that
system; it is up to the author/donor to decide if he or she is willing
to distribute software through any other system and a licensee cannot
impose that choice.
This section is intended to make thoroughly clear what is believed to
be a consequence of the rest of this License.
8. If the distribution and/or use of the Program is restricted in
certain countries either by patents or by copyrighted interfaces, the
original copyright holder who places the Program under this License
may add an explicit geographical distribution limitation excluding
those countries, so that distribution is permitted only in or among
countries not thus excluded. In such case, this License incorporates
the limitation as if written in the body of this License.
9. The Free Software Foundation may publish revised and/or new versions
of the General Public License from time to time. Such new versions will
be similar in spirit to the present version, but may differ in detail to
address new problems or concerns.
Each version is given a distinguishing version number. If the Program
specifies a version number of this License which applies to it and "any
later version", you have the option of following the terms and conditions
either of that version or of any later version published by the Free
Software Foundation. If the Program does not specify a version number of
this License, you may choose any version ever published by the Free Software
Foundation.
10. If you wish to incorporate parts of the Program into other free
programs whose distribution conditions are different, write to the author
to ask for permission. For software which is copyrighted by the Free
Software Foundation, write to the Free Software Foundation; we sometimes
make exceptions for this. Our decision will be guided by the two goals
of preserving the free status of all derivatives of our free software and
of promoting the sharing and reuse of software generally.
NO WARRANTY
11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN
OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED
OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS
TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE
PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING,
REPAIR OR CORRECTION.
12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES,
INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED
TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY
YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES.
END OF TERMS AND CONDITIONS
How to Apply These Terms to Your New Programs
If you develop a new program, and you want it to be of the greatest
possible use to the public, the best way to achieve this is to make it
free software which everyone can redistribute and change under these terms.
To do so, attach the following notices to the program. It is safest
to attach them to the start of each source file to most effectively
convey the exclusion of warranty; and each file should have at least
the "copyright" line and a pointer to where the full notice is found.
<one line to give the program's name and a brief idea of what it does.>
Copyright (C) <year> <name of author>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Also add information on how to contact you by electronic and paper mail.
If the program is interactive, make it output a short notice like this
when it starts in an interactive mode:
Gnomovision version 69, Copyright (C) year name of author
Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
This is free software, and you are welcome to redistribute it
under certain conditions; type `show c' for details.
The hypothetical commands `show w' and `show c' should show the appropriate
parts of the General Public License. Of course, the commands you use may
be called something other than `show w' and `show c'; they could even be
mouse-clicks or menu items--whatever suits your program.
You should also get your employer (if you work as a programmer) or your
school, if any, to sign a "copyright disclaimer" for the program, if
necessary. Here is a sample; alter the names:
Yoyodyne, Inc., hereby disclaims all copyright interest in the program
`Gnomovision' (which makes passes at compilers) written by James Hacker.
<signature of Ty Coon>, 1 April 1989
Ty Coon, President of Vice
This General Public License does not permit incorporating your program into
proprietary programs. If your program is a subroutine library, you may
consider it more useful to permit linking proprietary applications with the
library. If this is what you want to do, use the GNU Library General
Public License instead of this License.