killer-0.90/ 40755 611 12 0 7050557615 11440 5ustar gerdtsstaffkiller-0.90/ChangeLog100644 611 12 1134 6676766107 13321 0ustar gerdtsstaffFri Mar 26 14:16:50 CST 1999 Mike Gerdts * Initial in-house version completed (no version number). Based on concepts from earlier versions known as bgjk, but free from earlier version's code, algorithms, and shortcomings (I hope!). killer-0.90/Makefile100644 611 12 1124 6676743433 13203 0ustar gerdtsstaffSCRIPTNAME = killer # Man page information SECTION = 1 RELEASE = " " CENTER = " " TARGETS = $(SCRIPTNAME).html $(SCRIPTNAME).$(SECTION) $(SCRIPTNAME).txt all: $(TARGETS) $(SCRIPTNAME).html: $(SCRIPTNAME) pod2html $(SCRIPTNAME) --outfile=$@ $(SCRIPTNAME).$(SECTION): $(SCRIPTNAME) pod2man --section=$(SECTION) --release=$(RELEASE) --center=$(CENTER) $(SCRIPTNAME) > $@ $(SCRIPTNAME).txt: $(SCRIPTNAME) pod2text $(SCRIPTNAME) > $(SCRIPTNAME).txt clean: -rm -f $(TARGETS) pod2html-*cache install: @echo "You probably want to customize the script then copy it into place yourself." 1>&2 killer-0.90/COPYING100644 611 12 43076 6676763627 12641 0ustar gerdtsstaff GNU GENERAL PUBLIC LICENSE Version 2, June 1991 Copyright (C) 1989, 1991 Free Software Foundation, Inc. 675 Mass Ave, Cambridge, MA 02139, 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. 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(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. 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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. 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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 Appendix: 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. Copyright (C) 19yy 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., 675 Mass Ave, Cambridge, MA 02139, 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) 19yy 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. , 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. killer-0.90/killer100755 611 12 102211 7050557615 13002 0ustar gerdtsstaff#! /usr/bin/perl -w # ############################################################################# # # Copyright (C) 1999, 2000 Michael Gerdts (gerdts@cae.wisc.edu) # # This software was written to ease my work at the University of Wisconsin. # The University of Wisconsin may use this software under any terms that # they see fit. The use of an Open Source license, as recognized by the # Open Source Initiative (http://www.opensource.org/), is encouraged by the # author. # # As for everyone else: # # 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., # 675 Mass Ave, Cambridge, MA 02139, USA. # # ############################################################################# my $version = "0.90"; =head1 NAME killer - Background job killer =head1 SYNOPSIS killer [B<-h>] [B<-V>] =head1 DESCRIPTION I is a perl script that gets rid of background jobs. Background jobs are defined as processes that belong to users who are not currently logged into the machine. Jobs can be run in the background (and are expempt from I's acctions) if their scheduling priority has been reduced by increasing their nice(1) value or if they are being run through I. For more details, see the I section of this document. The following sections describe the perl(1) packages that make up the killer program. I don't expect that the version that works for me will work for everyone. I think that the ProcessTable and Terminals packages offer enough flexibility that most modifications can be done in the main package. Command line options =over 4 =item -h Tell me how to get help =item -V Display version number =back =cut use strict; use Sys::Syslog; package ProcessTable; use Sys::Syslog; =head1 PACKAGE ProcessTable Each ProcessTable object contains hashes (or associative arrays) that map various aspects of a job to the process ID (PID). The following hashes are provided: =over 12 =item pid2user Login name associated with the effective UID that the process is running as. =item pid2ruser Login name associate with the real UID that the process is running as. =item pid2uid Effective UID that the process is running as. =item pid2ruid Real UID that the process is running as. =item pid2tty Terminal associated with the process. =item pid2ppid Parent process of the process =item pid2nice nice(1) value of the process. =item pid2comm Command name of the process. =back Additionally, the %remainingprocs hash provides the list of processes that will be killed. The intended use of this package calls for I to be called to fill in all of the hashes defined above. Then, processes that meet specific requirements are removed from the %remainingprocs hash. Those that are not removed are considered to be background processes and may be killed. =cut # On HP-UX be sure that env var UNIX95 is defined for ps -o to work! my $pscmd = '/usr/bin/ps -e -o "user ruser uid ruid tty pid ppid nice comm"'; my $errmsg; my %pid2user = (); # login name of effective uid my %pid2ruser = (); # login name of real user id my %pid2uid = (); # effective UID of user my %pid2ruid = (); # real UID of user my %pid2tty = (); # tty associated with process my %pid2ppid = (); # parent process ID my %pid2nice = (); # nice value my %pid2comm = (); # Command name being executed my %remainingprocs = (); # The processes that have not been eliminated =head2 new This function creates a new I object. Example: my $ptable = new ProcessTable; =cut sub new { my $this = shift; my $class = ref($this) || $this; my $self = {} ; bless $self, $class; $self->initialize(); $errmsg = ""; return $self; } =head2 initialize This function (re)initializes arrays and any environment variables for external commands. It generally will not need to be called, as it is invoked by new(). Example: # Empty out the process table for reuse $ptable->initialize(); =cut sub initialize() { # This is required for ps(1) to work right on HP's defined($ENV{UNIX95}) || ($ENV{UNIX95} = 1); # Make sure that these are all empty... %pid2user = (); # login name of effective uid %pid2ruser = (); # login name of real user id %pid2uid = (); # effective UID of user %pid2ruid = (); # real UID of user %pid2tty = (); # tty associated with process %pid2ppid = (); # parent process ID %pid2nice = (); # nice value %pid2comm = (); # Command name being executed %remainingprocs = (); # The processes that have not been eliminated return; } =head2 readProcessTable This function executes the ps(1) command to figure out which processes are running. Note that it requires a SYSV style ps(1). Example: # Get a list of processes from the OS $ptable->readProcessTable(); =cut sub readProcessTable { my $self = shift; my ($user, $ruser, $uid, $ruid, $tty, $pid, $ppid, $nice, $comm); open ( PS, "$pscmd|" ) || do { $errmsg = "\"$pscmd\" failed: $!"; return undef; }; # skip the first line of input ; while () { #print "\t$_"; chop; # strip leading white space $_ =~ s/^[ ]*//; ($user, $ruser, $uid, $ruid, $tty, $pid, $ppid, $nice, $comm) = split( /[ \t]+/, $_, 9 ); $pid2user{$pid} = $user; $pid2ruser{$pid} = $ruser; $pid2uid{$pid} = int $uid; $pid2ruid{$pid} = int $ruid; $pid2tty{$pid} = $tty; $pid2ppid{$pid} = int $ppid; $pid2nice{$pid} = $nice; if ( defined $comm ) { $pid2comm{$pid} = $comm; } else { $pid2comm{$pid} = ''; } $remainingprocs{$pid} = 1; } close(PS); } =head2 cleanForkBombs This function looks for a large number of processes owned by one user, and assumes that it is someone that is using fork() for the first time. An effective way to clean up such a mess is to "kill -STOP" each process then "kill -KILL" each process. Note this function ignores such mistakes by root. If root is running a fork(2) bomb, this script wouldn't run, right? Also, you should be sure that the number of processes mentioned below (490) is less (equal to would be better, right?) than the maximum number of processes per user. Also, the OS should have a process limit at least a couple hundred higher than any individual. Otherwise, you will have to use the power switch to get rid of fork bombs. Each time a process is sent a signal, it is logged via syslog(3C). Example: # Get rid of fork bombs. Keep track of who did it in @idiots. my @idiots = $ptable->cleanForkBombs(); =cut sub cleanForkBombs { my $self = shift; my ( @procs, $pid, $user, @bombers); @bombers = (); foreach $user ( $self->getUsers() ) { next if ( $user eq "root" ); @procs = $self->getUserProcessIds($user); if ( $#procs > 490 ) { # first send a SIGSTOP foreach $pid ( @procs ) { if ( kill(23, $pid) > 0 ) { syslog('info', "kill(23, $pid) user=%s command=%s nice=%d", $pid2ruser{$pid}, $pid2comm{$pid}, $pid2nice{$pid}); } } # next send a SIGKILL foreach $pid ( @procs ) { if ( kill(9, $pid) > 0 ) { syslog('info', "kill(9, $pid) user=%s command=%s nice=%d", $pid2ruser{$pid}, $pid2comm{$pid}, $pid2nice{$pid}); } } push @bombers, $user; } } return(@bombers); } =head2 getUserProcessIds user This returns the list of process ID's where the login associated with the real UID of the process matches the argument to the function. Example: # Find all processes owned by httpd my @webservers = $ptable->getUserProcessIds('httpd'); =cut sub getUserProcessIds($) { my $self = shift; my ($login) = @_; my @pids = (); my ( $key, $value ); while ( ($key, $value) = each(%pid2ruser) ) { next unless ( $value eq $login ); push @pids, $key; } return(@pids); } =head2 getUniqueTtys This function returns a list of terminals in use. Note that the format will be the same as given by ps(1), which will generally lack the leading "/dev/". Example: # Get a list of all terminals that processes are attached to my @ttylist = $ptable->getUniqueTtys(); =cut sub getUniqueTtys { my $self = shift; my %ttys; my $tty; foreach $tty ( keys %pid2tty ) { $ttys{$tty} = 1; } return(keys %ttys); } =head2 removeProcessId pid This function removes pid from the list of processes to be killed. That is, it gets rid of a process that should be allowed to run. Most likely this will only be called by other functions in this package. Example: # For some reason I know that PID 1234 should be allowed to run $ptable->removeProcessId(1234); =cut sub removeProcessId($) { my $self = shift; my ($pid) = @_; if (defined $remainingprocs{$pid} ) { delete $remainingprocs{$pid} } } =head2 removeProcesses psfield, psvalue This function removes processes that possess certain traits. For example, if you want to get rid of all processes owned by the user "lp" or all processes that have /dev/console as their controlling terminal, this is the function for you. psfield can be any of the following =over 8 =item pid Removes process id given in second argument. =item user Removes processes with effective UID associated with login name given in second argument. =item ruser Removes processes with real UID associated with login name given in second argument. =item uid Removes processes with effective UID given in second argument. =item ruid Removes processes with real UID given in second argument. =item tty Removes processes with controlling terminal given in second argument. Note that it should NOT start with "/dev/". =item ppid Removes children of process with PID given in second argument. =item nice Removes children with a nice value equal to the second argument. =item comm Removes children with a command name that is the same as the second argument. =back Examples: # Allow all imapd processes to run $ptable->removeProcesses('comm', 'imapd'); # Be sure not to kill print jobs $ptable->removeProcesses('ruser', 'lp'); =cut sub removeProcesses($$) { my $self = shift; my ( $field, $value ) = @_; my ( $pid ); SWITCH: { ($field eq "pid") && do { $self->removeProcessId($value); last SWITCH; }; ($field eq "user") && do { foreach $pid ( keys %pid2user ) { if ( $pid2user{$pid} eq $value ) { $self->removeProcessId($pid); } } last SWITCH; }; ($field eq "ruser") && do { foreach $pid ( keys %pid2ruser ) { if ( $pid2ruser{$pid} eq $value ) { $self->removeProcessId($pid); } } last SWITCH; }; ($field eq "uid") && do { foreach $pid ( keys %pid2uid ) { if ( $pid2uid{$pid} == $value ) { $self->removeProcessId($pid); } } last SWITCH; }; ($field eq "ruid") && do { foreach $pid ( keys %pid2ruid ) { if ( $pid2ruid{$pid} == $value ) { $self->removeProcessId($pid); } } last SWITCH; }; ($field eq "tty") && do { foreach $pid ( keys %pid2tty ) { if ( $pid2tty{$pid} eq $value ) { $self->removeProcessId($pid); } } last SWITCH; }; ($field eq "ppid") && do { foreach $pid ( keys %pid2ppid ) { if ( $pid2ppid{$pid} == $value ) { $self->removeProcessId($pid); } } last SWITCH; }; ($field eq "nice") && do { foreach $pid ( keys %pid2nice ) { if ( $pid2nice{$pid} eq $value ) { $self->removeProcessId($pid); } } last SWITCH; }; ($field eq "comm") && do { foreach $pid ( keys %pid2comm ) { if ( $pid2comm{$pid} eq $value ) { $self->removeProcessId($pid); } } last SWITCH; }; }; } =head2 removeChildren pid This function removes all decendents of the given pid. That is, if the pid argument is 1, it will ensure that nothing is killed. Example: # Be sure not to kill off any mail deliveries (assumes you have # written getSendmailPid()). (Sendmail changes uid when it does # local delivery.) $ptable->removeChildren(getSendmailPid); =cut sub removeChildren($) { my $self = shift; my ($ppid) = @_; my ( @children); my ( $child, $parent ); while ( ($child, $parent) = each(%pid2ppid) ) { if ( $parent == $ppid ) { push(@children, $child); } } foreach $child ( @children ) { $self->removeChildren($child); $self->removeProcessId($child); } } =head2 removeCondorChildren Condor is a batch job system that allows migration of jobs between machines (see http://www.cs.wisc.edu/condor/). This ensures that condor jobs are left alone. Example: # Be nice to the people that are running their jobs through condor. $ptable->removeCondorChildren(); =cut sub removeCondorChildren { my $self = shift; my $pid; foreach $pid ( keys %pid2comm ) { # find the command with the right name next unless ( $pid2comm{$pid} eq 'condor_master' ); # be sure that it is owned by root next unless ( $pid2uid{$pid} == 0 ); # Remove all of its child processes $self->removeChildren($pid); }; } =head2 findChildProcs pid This function finds and returns a list of all of the processess that are descendents of a the PID given in the first argument. Example: # Find the processes that are decendents of PID 1234 my @procs = $ptable->findChildProcs(1234); =cut sub findChildProcs($) { my $self = shift; my ($ppid) = (@_); my ( $child, $parent, @children, @returnchildren ); while ( ($child, $parent) = each(%pid2ppid) ) { if ( $parent == $ppid ) { push(@children, $child); } } push ( @returnchildren, @children); foreach $child ( @children ) { push @returnchildren, $self->findChildProcs($child); } return(@returnchildren); } =head2 getTtys user This function returns a list of tty's that are in use by processes owned by a particular user. Example: # find all tty's in use by gerdts. my @ttylist = getTtys('gerdts'); =cut sub getTtys ($) { my $self = shift; my ($user) = ( @_ ); my ( $pid, $login, %ttys ); while ( ($pid, $login ) = each(%pid2user) ) { next unless ( $login eq $user ); $ttys{${pid2tty{$pid}}} = 1; } return (keys %ttys); } =head2 getUsers This function lists all the users that have active processes. Example: # Get all users that are logged in my @lusers = $ptable->getUsers() =cut sub getUsers() { my $self = shift; my ( $pid, $login, %logins ); while ( ($pid, $login) = each(%pid2user) ) { $logins{$login} = 1; } return(keys %logins); } =head2 removeNiceJobs This function removes all jobs that have a nice value greater than 20. That is, they have a lower sceduling priority than the default. Example: # Allow people to run background jobs so long as they yield to # those with "foreground" jobs $ptable->removeNiceJobs(); =cut sub removeNiceJobs() { my $self = shift; my ( $key, $val ); while ( ($key, $val) = each(%pid2nice) ) { # Get rid of things not in the "default" scheduling class next unless ($val =~ /^[0-9]+$/); if ( int($val) > 20 ) { $self->removeProcessId($key); } } } =head2 printProcess filehandle, pid This function displays information about the process, kinda like "ps | grep" would. Example: # Print info about init to STDERR $ptable->printProcess(\*STDERR, 1); =cut sub printProcess($$) { my $self = shift; my ( $fh, $pid ) = @_; printf $fh "%8s %8s %5d %5d %s\n", $pid2user{$pid}, $pid2ruser{$pid}, $pid, $pid2ppid{$pid}, $pid2comm{$pid}; } =head2 printProcessTable =head2 printProcessTable filehandle This function prints info about all the processes discoverd by I. If an argument is given, it should be a file handle to which the output should be printed. Examples: # Print the process table to stdout $ptable->printProcessTable(); # Mail the process table to someone open MAIL '|/usr/bin/mail someone'; $ptable->printProcessTable(\*MAIL); close(MAIL); =cut sub printProcessTable { my $self = shift; my ( $fh ) = shift || \*STDOUT; my $pid; print $fh " user ruser pid ppid command\n"; print $fh "======== ======== ===== ===== =================================================\n"; foreach $pid ( sort keys %pid2comm ) { $self->printProcess($fh, $pid); } print $fh "======== ======== ===== ===== =================================================\n"; } =head2 printRemainingProcesses =head2 printRemainingProcesses filehandle This function prints info about all the processes discoverd by I, but not removed from %remainingprocs. If an argument is given, it should be a file handle to which the output should be printed. Examples: # Print the jobs to be killed to stdout $ptable->printRemainingProcesses(); # Mail the jobs to be killed to someone open MAIL '|/usr/bin/mail someone'; $ptable->printRemainingProcesses(\*MAIL); close(MAIL); =cut sub printRemainingProcesses { my $self = shift; my $fh = shift || \*STDOUT; print $fh " user ruser pid ppid command\n"; print $fh "======== ======== ===== ===== =================================================\n"; foreach my $pid ( keys %remainingprocs ) { $self->printProcess($fh, $pid); } print $fh "======== ======== ===== ===== =================================================\n"; } =head2 getRemainingProcesses Returns a list of processes that are likely background jobs. Example: # Get a list of the processes that I plan to kill my @procsToKill = $ptable->getRemainingProcesses(); =cut sub getRemainingProcesses { my $self = shift; return keys %remainingprocs; } =head2 killAll signalNumber Sends the specified signal to all the processes listed. A syslog entry is made for each signal sent. Example: # Send all of the remaining processes a TERM signal, then a # KILL signal $ptable->killAll(15); sleep(10); # Give them a bit of a chance to clean up $ptable->killAll(9); =cut sub killAll($) { my $self = shift; my ( $signum ) = @_; my $killcount = 0; foreach my $pid ( keys %remainingprocs ) { if ( kill($signum, $pid) > 0 ) { $killcount ++; syslog('info', "kill($signum, $pid) user=%s command=%s nice=%d", $pid2ruser{$pid}, $pid2comm{$pid}, $pid2nice{$pid}); } } return $killcount; } package Terminals; =head1 PACKAGE Terminals The Terminals package provides a means for figuring out how long various users have been idle. =cut my %tty2user; my %user2ttys; my %tty2idletime; my $consoleuser; my $whocmd = '/usr/bin/who'; =head2 new This function is used to instantiate a new Terminals object. Example: # Get a new Terminals object. my $term = new Terminals; =cut sub new { my $this = shift; my $class = ref($this) || $this; my $self = {} ; bless $self, $class; $self->initialize(); $errmsg = ""; return $self; } =head2 initialize This function figures out who is on the system and how long they have been idle for. It will generally only be called by new(). Example: # Refresh the state of the terminals. $term->initialize(); =cut sub initialize { my $self = shift; my @parts; $consoleuser = ""; open ( W, "$whocmd|") || return; while ( ) { chop; @parts = split(/[ \t]+/); if ( $parts[1] eq 'console' ) { $consoleuser = $parts[0]; } $self->initializeTty($parts[1], stat("/dev/" . $parts[1])); } close(W); } =head2 showConsoleUser This function returns the login of the person that is physically sitting at the machine. Example: # Print out the login of the person on the console printf "%s is on the console\n", $term->showConsoleUser(); =cut sub showConsoleUser() { my $self = shift; return $consoleuser; } =head2 initializeTty terminal statparts This initializes internal structures for the given terminal. =cut sub initializeTty($@) { my $self = shift; my ( $key, @statparts ) = @_; # Argument check return unless defined ( $statparts[4] ); # Figure out how long the tty has been idle $tty2idletime{$key} = time - $statparts[8]; # Figure out who is on the terminal my ( @pwparts ) = getpwuid($statparts[4]); return unless defined ( $pwparts[0] ); $tty2user{$key} = $pwparts[0]; push (@{$user2ttys{$pwparts[0]}}, $key); } =head2 getIdleTime user Figure out how long a user has been idle. This is accomplished by examining all terminals that the user owns and returns the amount of time since the most recently accessed one was used. Additionally, if the user is at the console it is possible that he/she is not typing, yet is quite active with the mouse or typing into an application that does not use a terminal. Example: # Figure out how long the user on the console has been idle my $consoleIdle = $term-getIdleTime($term->showConsoleUser()); =cut sub getIdleTime($) { my $self = shift; my ( $user ) = @_; my $idletime = 99999999; my $tty; return $idletime if ( ! defined $user2ttys{$user} ); my ( @ttys ) = ( @{$user2ttys{$user}} ); foreach $tty ( @ttys ) { next unless defined($tty2idletime{$tty}); if ( int($tty2idletime{$tty}) < int($idletime) ) { $idletime = int($tty2idletime{$tty}); } } if ( $consoleuser eq $user ) { my (@statparts, $device); foreach $device ( '/dev/ps2mouse', '/dev/ps2kbd', '/dev/mouse', '/dev/kbd' ) { @statparts = stat($device); next unless defined($statparts[8]); if ( ( time - $statparts[8] ) < $idletime ) { $idletime = (time - $statparts[8]); } } } return $idletime; } =head2 printEverything Prints to stdout who is on what terminal and how long they have been idle. Only useful for debugging. Example: # Take a look at the contents of structures in my # Terminals object $term->printEverything(); =cut sub printEverything { my $self = shift; my ( $k, $v); print "\ntty -> user\n"; while ( ($k, $v) = each(%tty2user) ) { print "$k -> $v\n"; } print "\ntty -> idle\n"; while ( ($k, $v) = each(%tty2idletime) ) { print "$k -> $v\n"; } print "\nuser -> ttys\n"; while ( ($k, $v) = each(%user2ttys) ) { print "$k -> ", join( ',', @{$v}), "\n"; } } package main; if ( $#ARGV != -1 ) { foreach my $opt ( @ARGV ) { $opt eq '-h' && do { print STDERR "Type \"perldoc $0\" for lots of help.\n"; next; }; $opt eq '-V' && do { print STDERR "killer version $version\n"; next; }; print STDERR "killer: option \"$opt\" not recognized\n"; print STDERR "Type \"perldoc $0\" for lots of help.\n"; } exit(1); } =head1 PACKAGE main The main package is the version used on the Unix workstations at the University of Wisonsin's Computer-Aided Engineering Center (CAE). I suspect that folks at places other than CAE will want to do things slightly differently. Feel free to take this as an example of how you can make effective use of the processTable and Terminals packages. =head2 Configuration options =over 12 =cut # ######## # Configuration options: # ######## my $domainname = `domainname`; chop $domainname; =item $forkadmin Email address to notify of fork bombs =cut my $forkadmin = "killer\@$domainname"; =item $killadmin Email address to notify of run-of-the-mill kills =cut my $killadmin = "killer\@$domainname"; =item $fromaddr Who do email messages claim to be from? =cut my $fromaddr = "\"Background Job Killer v. $version\" "; =item $stubbornadmin Email address to notify when jobs will not die =cut my $stubbornadmin = "killer\@$domainname"; =item @validusers These are the folks that you should never kill off =cut my @validusers = ( 'condor', 'root', 'daemon' ); =item $maxidletime The maximum number of seconds that a user can be idle without being classified as having "background" jobs. =cut my $maxidletime = ( 6 * 60 * 60 ); # ######## # End of (intended) configuration options. # ######## =back If I am a user really trying to avoid a background job killer, I would likely include a signal handler that would wait for signal 15. When I saw it, I would fork causing the parent to die and the child would continue on to do my work. Assuming that everyone thinks like me, I figure that I will need to make at least two complete passes to clear up the bad users. The first pass is relatively nice (sends a signal 15, followed a bit later by a signal 9). A well-written program will take the signal 15 as a sign that it should clean up and then shut down. When a process gets a signal 9, it has no choice but to die. The second pass is not so nice. It finds all background processes, sends them a signal 23 (SIGSTOP), then a signal 9 (SIGKILL). This pretty much (but not absolutely) guarantees that processes are unable to find a way around the background job killer. =cut my @ttys; my @users; my $user; =head2 gatherInfo This function gathers information from the Terminals and ProcessTable packages, then based on that information decides which jobs should be allowed to run. Specifically it does the following: =over 2 =cut sub gatherInfo { =item * Instantiates new ProcessTable and Terminals objects. Note that Terminals::new fills in all the necessary structures to catch users that have logged in between calls to I. =cut my $ptable = new ProcessTable; my $term = new Terminals; =item * Reads the process table =cut $ptable->readProcessTable(); =item * Removes condor processes and condor jobs from the list of processes to be killed. =cut $ptable->removeCondorChildren(); =item * Removes all jobs belonging to all users in the configuration array @validusers from the list of processes to be killed. =cut foreach $user ( @validusers ) { $ptable->removeProcesses('ruser', $user); } =item * Removes all nice(1) jobs from the list of jobs to be killed. =cut $ptable->removeNiceJobs(); =item * Removes all jobs belonging to users where the user has less than $maxidletime idle time on at least one terminal. Additionally, jobs associated with ttys that are owned by users that have less than $maxidletime idle time on at least one terminal are preserved. This makes it so that if luser uses su(1) to gain the privileges of boozer, processes owned by boozer will not be killed. =cut foreach $user ( $ptable->getUsers() ) { if ( $term->getIdleTime($user) < $maxidletime ) { $ptable->removeProcesses('ruser', $user); # Be aware that some users may have su'd to others. The two users # will share the same tty. $ptable->removeProcesses('tty', $ptable->getTtys($user)); } } =item * Finally, the process table and terminal objects are returned. =back =cut return($ptable, $term); } openlog('killer', 'pid', 'local4'); my $sendmail; if ( -x '/usr/lib/sendmail' ) { $sendmail = '/usr/lib/sendmail'; } elsif ( -x '/usr/sbin/sendmail' ) { $sendmail = '/usr/sbin/sendmail'; } else { die "Cannot find executable sendmail\n"; } my $outfile; # ######### # Read the process table, then check for fork() bombs. # ######### my ($ptable, $term) = gatherInfo(); my @bombers = $ptable->cleanForkBombs(); if ( $#bombers != -1 ) { if ( open(MAIL, "|$sendmail -t") ) { $outfile = \*MAIL; print $outfile "From: $fromaddr\n"; print $outfile "To: $forkadmin\n"; print $outfile 'Subject: Fork bombs found on ' . `uname -n`; print $outfile "\n"; print $outfile "The following users had lots of processes running on " . `uname -n`; print $outfile "\t", join(' ', @bombers); print $outfile "\nYou can find more information in the syslog logs\n"; close($outfile); } } # ########## # In the first round, try to nicely kill off processes, giving them # time to clean up before they get the kill -9 # ########## my ( @remaining ) = $ptable->getRemainingProcesses(); if ( $#remaining == -1 ) { exit(0); } if ( open(MAIL, "|$sendmail -t") ) { $outfile = \*MAIL; } else { $outfile = \*STDERR; } print $outfile "From: $fromaddr\n"; print $outfile "To: $killadmin\n"; print $outfile 'Subject: Jobs killed on ' . `uname -n`; print $outfile "\n"; print $outfile "Attempt 1: Nicely killing the following processes\n"; $ptable->printRemainingProcesses($outfile); $ptable->killAll(15); sleep(30); $ptable->killAll(9); # ######### # The second time around, assume that when a process got killed # before, it either spawned a new process (at the kill 15) or # freed up a process table entry so that another process could # be spawned. This should catch fork() bombs as well # ########## sleep(5); ($ptable, $term) = gatherInfo(); ( @remaining ) = $ptable->getRemainingProcesses(); if ( $#remaining == -1 ) { close(MAIL); exit(0); } # first send all the processes a STOP. This makes it so that # none of the processes can do anything once they notice that # there are free process slots, etc. print $outfile "\nAttempt 2: Taking care of stubborn jobs\n"; $ptable->printRemainingProcesses($outfile); $ptable->killAll(23); $ptable->killAll(9); # ######## # The third time around, I just can't figure out how to kill # the processes. Let's just whine through email. # ######## sleep(5); ($ptable, $term) = gatherInfo(); ( @remaining ) = $ptable->getRemainingProcesses(); if ( $#remaining == -1 ) { close(MAIL); exit(0); } print $outfile "\nHELP ME: Unable to kill the following jobs\n"; $ptable->printRemainingProcesses($outfile); close(MAIL); if ( open(MAIL, "|$sendmail -t") ) { $outfile = \*MAIL; print $outfile "From: $fromaddr\n"; print $outfile "To: $stubbornadmin\n"; print $outfile 'Subject: Cannot kill some jobs on ' . `uname -n`; print $outfile "\n"; print $outfile "The background job killer could not kill some jobs on " . `uname -n` . "\n"; $ptable->printRemainingProcesses($outfile); print $outfile "\nMore info can be found in syslog and the killer mailbox\n"; close(MAIL); } exit(0); =head1 BUGS There is a small window of opportunity for a user that reaches $maxidletime in the middle of this script to get unfair treatment. This could probably be reconciled by shaving some time off of maxidletime for the second call to main::gatherInfo. It is still possible to get around the background job killer by having a lot of proceses that watch each other to be sure that they are still responding (have not yet gotten a signal 23). As soon as a stopped process is found, the still running process could fork(), thus leaving a background process that is not going to be killed. Different operating systems have different notions of nice values. Some go from -20 to +19. Some go from 0 to 39. Solaris and HP-UX (using System V ps command) report nice values between 0 and 39. It is bad to assume that all systems that run this have the same number of processes per user. The script should ask the OS how many processes normal (non-root) users can run. =head1 TODO The configuration is quite minimalistic. It should be made possible to have per-host configuration directives so that you can, for instance, allow certain people to run background jobs on certain hosts. People that really care about finding habitual offenders will probably want to have a way to add entries to a database and flag those that pop up too often. Thoroughly test on more operating systems. A very close relative of this code has performed well on about 60 Solaris 2.5.1 machines. It has been lightly tested on HP-UX 10.20 as well. Make mailing to someone optional. If you have a lot of workstations killing off boring stuff all the time, too much meaningless mail traffic is generated. If you plan to run this on a machine that runs special processes like a POP or IMAP server, it would be handy to be able to check multiple conditions easily. Perhaps $ptable->removeProcesses( { comm => 'imapd', parentComm => 'inetd', parentUser => 'root' } ); This would make it so that people don't rename the crack binary imapd to escape the wrath of killer. =head1 LICENSE This program is released under the terms of the General Public License (GPL) version 2. The the file COPYING with the distribution. If you have lost your copy, you can get a new one at http://www.gnu.org/copyleft/gpl.html. In particular remember that this code is distributed for free without warranty. If you make use of this code, please send me some email. While I am open to suggestions to improvement, I by no means guarantee that I will implement them. =head1 SEE ALSO nice(1) perl(1) ps(1) su(1) who(1) fork(2) signal(5) http://www.cs.wisc.edu/condor/ http://www.cae.wisc.edu/~gerdts/killer/ =head1 AUTHOR killer was written by Mike Gerdts, gerdts@cae.wisc.edu.