freebsd-skq/usr.sbin/adduser/rmuser.perl
yar b4afbb7b01 Found a single point where rmuser(8) wasn't robust to strange
characters in a username:  where it was inserted into a regexp.
Fix it by escaping metacharacters in the name with \Q-\E.
2002-02-11 15:26:20 +00:00

602 lines
16 KiB
Perl

#!/usr/bin/perl
# -*- perl -*-
# Copyright 1995, 1996, 1997 Guy Helmer, Ames, Iowa 50014.
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer as
# the first lines of this file unmodified.
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
# 3. The name of the author may not be used to endorse or promote products
# derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY GUY HELMER ``AS IS'' AND ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
# IN NO EVENT SHALL GUY HELMER BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
# rmuser - Perl script to remove users
#
# Guy Helmer <ghelmer@cs.iastate.edu>, 02/23/97
#
# $FreeBSD$
use Fcntl;
sub LOCK_SH {0x01;}
sub LOCK_EX {0x02;}
sub LOCK_NB {0x04;}
sub LOCK_UN {0x08;}
sub F_SETFD {2;}
$ENV{"PATH"} = "/bin:/sbin:/usr/bin:/usr/sbin";
umask(022);
$whoami = $0;
$passwd_file = "/etc/master.passwd";
$passwd_tmp = "/etc/ptmp";
$group_file = "/etc/group";
$new_group_file = "${group_file}.new.$$";
$mail_dir = "/var/mail";
$crontab_dir = "/var/cron/tabs";
$affirm = 0;
#$debug = 1;
sub cleanup {
local($sig) = @_;
print STDERR "Caught signal SIG$sig -- cleaning up.\n";
&unlockpw;
if (-e $new_passwd_file) {
unlink $new_passwd_file;
}
exit(0);
}
sub lockpw {
# Open the password file for reading
if (!open(MASTER_PW, "$passwd_file")) {
print STDERR "${whoami}: Error: Couldn't open ${passwd_file}: $!\n";
exit(1);
}
# Set the close-on-exec flag just in case
fcntl(MASTER_PW, &F_SETFD, 1);
# Apply an advisory lock the password file
if (!flock(MASTER_PW, &LOCK_EX|&LOCK_NB)) {
print STDERR "${whoami}: Error: Couldn't lock ${passwd_file}: $!\n";
exit(1);
}
}
sub unlockpw {
flock(MASTER_PW, &LOCK_UN);
}
$SIG{'INT'} = 'cleanup';
$SIG{'QUIT'} = 'cleanup';
$SIG{'HUP'} = 'cleanup';
$SIG{'TERM'} = 'cleanup';
if ($#ARGV == 1 && $ARGV[0] eq '-y') {
shift @ARGV;
$affirm = 1;
}
if ($#ARGV > 0) {
print STDERR "usage: ${whoami} [-y] [username]\n";
exit(1);
}
if ($< != 0) {
print STDERR "${whoami}: Error: you must be root to use ${whoami}\n";
exit(1);
}
&lockpw;
if ($#ARGV == 0) {
# Username was given as a parameter
$login_name = pop(@ARGV);
} else {
if ($affirm) {
print STDERR "${whoami}: Error: -y option given without username!\n";
&unlockpw;
exit 1;
}
# Get the user name from the user
$login_name = &get_login_name;
}
($name, $password, $uid, $gid, $change, $class, $gecos, $home_dir, $shell) =
(getpwnam("$login_name"));
if (!defined $uid) {
print STDERR "${whoami}: Error: User ${login_name} not in password database\n";
&unlockpw;
exit 1;
}
if ($uid == 0) {
print "${whoami}: Error: I'd rather not remove a user with a uid of 0.\n";
&unlockpw;
exit 1;
}
if (! $affirm) {
print "Matching password entry:\n\n$name\:$password\:$uid\:$gid\:$class\:$change\:0\:$gecos\:$home_dir\:$shell\n\n";
$ans = &get_yn("Is this the entry you wish to remove? ");
if ($ans eq 'N') {
print "${whoami}: Informational: User ${login_name} not removed.\n";
&unlockpw;
exit 0;
}
}
#
# Get owner of user's home directory; don't remove home dir if not
# owned by $login_name
$remove_directory = 1;
if (-l $home_dir) {
$real_home_dir = &resolvelink($home_dir);
} else {
$real_home_dir = $home_dir;
}
#
# If home_dir is a symlink and points to something that isn't a directory,
# or if home_dir is not a symlink and is not a directory, don't remove
# home_dir -- seems like a good thing to do, but probably isn't necessary...
if (((-l $home_dir) && ((-e $real_home_dir) && !(-d $real_home_dir))) ||
(!(-l $home_dir) && !(-d $home_dir))) {
print STDERR "${whoami}: Informational: Home ${home_dir} is not a directory, so it won't be removed\n";
$remove_directory = 0;
}
if (length($real_home_dir) && -d $real_home_dir) {
$dir_owner = (stat($real_home_dir))[4]; # UID
if ($dir_owner != $uid) {
print STDERR "${whoami}: Informational: Home dir ${real_home_dir} is" .
" not owned by ${login_name} (uid ${dir_owner})\n," .
"\tso it won't be removed\n";
$remove_directory = 0;
}
}
if ($remove_directory && ! $affirm) {
$ans = &get_yn("Remove user's home directory ($home_dir)? ");
if ($ans eq 'N') {
$remove_directory = 0;
}
}
#exit 0 if $debug;
#
# Remove the user's crontab, if there is one
# (probably needs to be done before password databases are updated)
if (-e "$crontab_dir/$login_name") {
print STDERR "Removing user's crontab:";
system('/usr/bin/crontab', '-u', $login_name, '-r');
print STDERR " done.\n";
}
#
# Remove the user's at jobs, if any
# (probably also needs to be done before password databases are updated)
&remove_at_jobs($login_name);
#
# Kill all the user's processes
&kill_users_processes($login_name, $uid);
#
# Copy master password file to new file less removed user's entry
&update_passwd_file;
#
# Remove the user from all groups in /etc/group
&update_group_file($login_name);
#
# Remove the user's home directory
if ($remove_directory) {
print STDERR "Removing user's home directory ($home_dir):";
&remove_dir($home_dir);
print STDERR " done.\n";
}
#
# Remove files related to the user from the mail directory
#&remove_files_from_dir($mail_dir, $login_name, $uid);
$file = "$mail_dir/$login_name";
if (-e $file || -l $file) {
print STDERR "Removing user's incoming mail file ${file}:";
unlink $file ||
print STDERR "\n${whoami}: Warning: unlink on $file failed ($!) - continuing\n";
print STDERR " done.\n";
}
#
# Remove some pop daemon's leftover file
$file = "$mail_dir/.${login_name}.pop";
if (-e $file || -l $file) {
print STDERR "Removing pop daemon's temporary mail file ${file}:";
unlink $file ||
print STDERR "\n${whoami}: Warning: unlink on $file failed ($!) - continuing\n";
print STDERR " done.\n";
}
#
# Remove files belonging to the user from the directories /tmp, /var/tmp,
# and /var/tmp/vi.recover. Note that this doesn't take care of the
# problem where a user may have directories or symbolic links in those
# directories -- only regular files are removed.
&remove_files_from_dir('/tmp', $login_name, $uid);
&remove_files_from_dir('/var/tmp', $login_name, $uid);
&remove_files_from_dir('/var/tmp/vi.recover', $login_name, $uid)
if (-e '/var/tmp/vi.recover');
#
# All done!
exit 0;
sub get_login_name {
#
# Get new user's name
local($done, $login_name);
for ($done = 0; ! $done; ) {
print "Enter login name for user to remove: ";
$login_name = <>;
chomp $login_name;
if (not getpwnam("$login_name")) {
print STDERR "Sorry, login name not in password database.\n";
} else {
$done = 1;
}
}
print "User name is ${login_name}\n" if $debug;
return($login_name);
}
sub get_yn {
#
# Get a yes or no answer; return 'Y' or 'N'
local($prompt) = @_;
local($done, $ans);
for ($done = 0; ! $done; ) {
print $prompt;
$ans = <>;
chop $ans;
$ans =~ tr/a-z/A-Z/;
if (!($ans =~ /^[YN]/)) {
print STDERR "Please answer (y)es or (n)o.\n";
} else {
$done = 1;
}
}
return(substr($ans, 0, 1));
}
sub update_passwd_file {
local($skipped);
print STDERR "Updating password file,";
seek(MASTER_PW, 0, 0);
sysopen(NEW_PW, $passwd_tmp, O_RDWR|O_CREAT|O_EXCL, 0600) ||
die "\n${whoami}: Error: Couldn't open file ${passwd_tmp}:\n $!\n";
$skipped = 0;
while (<MASTER_PW>) {
if (/^\Q$login_name:/o) {
print STDERR "Dropped entry for $login_name\n" if $debug;
$skipped = 1;
} else {
print NEW_PW;
# The other perl password tools assume all lowercase entries.
# Add a warning to help unsuspecting admins who might be
# using the wrong tool for the job, or might otherwise
# be unwittingly holding a loaded foot-shooting device.
if (/^\Q$login_name:/io) {
my $name = $_;
$name =~ s#\:.*\n##;
print STDERR "\n\n\tThere is also an entry for $name in your",
"password file.\n\tThis can cause problems in some ",
"situations.\n\n";
}
}
}
close(NEW_PW);
seek(MASTER_PW, 0, 0);
if ($skipped == 0) {
print STDERR "\n${whoami}: Whoops! Didn't find ${login_name}'s entry second time around!\n";
unlink($passwd_tmp) ||
print STDERR "\n${whoami}: Warning: couldn't unlink $passwd_tmp ($!)\n\tPlease investigate, as this file should not be left in the filesystem\n";
&unlockpw;
exit 1;
}
#
# Run pwd_mkdb to install the updated password files and databases
print STDERR " updating databases,";
system('/usr/sbin/pwd_mkdb', '-p', ${passwd_tmp});
print STDERR " done.\n";
close(MASTER_PW); # Not useful anymore
}
sub update_group_file {
local($login_name) = @_;
local($i, $j, $grmember_list, $new_grent, $changes);
local($grname, $grpass, $grgid, $grmember_list, @grmembers);
$changes = 0;
print STDERR "Updating group file:";
open(GROUP, $group_file) ||
die "\n${whoami}: Error: couldn't open ${group_file}: $!\n";
if (!flock(GROUP, &LOCK_EX|&LOCK_NB)) {
print STDERR "\n${whoami}: Error: couldn't lock ${group_file}: $!\n";
exit 1;
}
local($group_perms, $group_uid, $group_gid) =
(stat(GROUP))[2, 4, 5]; # File Mode, uid, gid
open(NEW_GROUP, ">$new_group_file") ||
die "\n${whoami}: Error: couldn't open ${new_group_file}: $!\n";
chmod($group_perms, $new_group_file) ||
printf STDERR "\n${whoami}: Warning: could not set permissions of new group file to %o ($!)\n\tContinuing, but please check permissions of $group_file!\n", $group_perms;
chown($group_uid, $group_gid, $new_group_file) ||
print STDERR "\n${whoami}: Warning: could not set owner/group of new group file to ${group_uid}/${group_gid} ($!)\n\rContinuing, but please check ownership of $group_file!\n";
while ($i = <GROUP>) {
if (!($i =~ /\Q$login_name\E/)) {
# Line doesn't contain any references to the user, so just add it
# to the new file
print NEW_GROUP $i;
} else {
#
# Remove the user from the group
if ($i =~ /\n$/) {
chop $i;
}
($grname, $grpass, $grgid, $grmember_list) = split(/:/, $i);
@grmembers = split(/,/, $grmember_list);
undef @new_grmembers;
local(@new_grmembers);
foreach $j (@grmembers) {
if ($j ne $login_name) {
push(@new_grmembers, $j);
} else {
print STDERR " $grname";
$changes = 1;
}
}
if ($grname eq $login_name && $#new_grmembers == -1) {
# Remove a user's personal group if empty
print STDERR " (removing group $grname -- personal group is empty)";
$changes = 1;
} else {
$grmember_list = join(',', @new_grmembers);
$new_grent = join(':', $grname, $grpass, $grgid, $grmember_list);
print NEW_GROUP "$new_grent\n";
}
}
}
close(NEW_GROUP);
rename($new_group_file, $group_file) || # Replace old group file with new
die "\n${whoami}: Error: couldn't rename $new_group_file to $group_file ($!)\n";
close(GROUP); # File handle is worthless now
print STDERR " (no changes)" if (! $changes);
print STDERR " done.\n";
}
sub remove_dir {
# Remove the user's home directory
local($dir) = @_;
local($linkdir);
if (-l $dir) {
$linkdir = &resolvelink($dir);
# Remove the symbolic link
unlink($dir) ||
warn "${whoami}: Warning: could not unlink symlink $dir: $!\n";
if (!(-e $linkdir)) {
#
# Dangling symlink - just return now
return;
}
# Set dir to be the resolved pathname
$dir = $linkdir;
}
if (!(-d $dir)) {
print STDERR "${whoami}: Warning: $dir is not a directory\n";
unlink($dir) || warn "${whoami}: Warning: could not unlink $dir: $!\n";
return;
}
system('/bin/rm', '-rf', $dir);
}
sub remove_files_from_dir {
local($dir, $login_name, $uid) = @_;
local($path, $i, $owner);
print STDERR "Removing files belonging to ${login_name} from ${dir}:";
if (!opendir(DELDIR, $dir)) {
print STDERR "\n${whoami}: Warning: couldn't open directory ${dir} ($!)\n";
return;
}
while ($i = readdir(DELDIR)) {
next if $i eq '.';
next if $i eq '..';
$owner = (stat("$dir/$i"))[4]; # UID
if ($uid == $owner) {
if (-f "$dir/$i") {
print STDERR " $i";
unlink "$dir/$i" ||
print STDERR "\n${whoami}: Warning: unlink on ${dir}/${i} failed ($!) - continuing\n";
} else {
print STDERR " ($i not a regular file - skipped)";
}
}
}
closedir(DELDIR);
printf STDERR " done.\n";
}
sub invoke_atq {
local *ATQ;
my($user) = (shift || "");
my($path_atq) = "/usr/bin/atq";
my(@at) = ();
my($pid, $line);
return @at if ($user eq "");
if (!defined($pid = open(ATQ, "-|"))) {
die("creating pipe to atq: $!\n");
} elsif ($pid == 0) {
exec($path_atq, $user);
die("executing $path_atq: $!\n");
}
while(defined($_ = <ATQ>)) {
chomp;
if (/^\d\d.\d\d.\d\d\s+\d\d.\d\d.\d\d\s+(\S+)\s+\S+\s+(\d+)$/) {
push(@at, $2) if ($1 eq $user);
}
}
close ATQ;
return @at;
}
sub invoke_atrm {
local *ATRM;
my($user) = (shift || "");
my($path_atrm) = "/usr/bin/atrm";
my(@jobs) = @_;
my($pid);
my($txt) = "";
return "Invalid arguments" if (($user eq "") || ($#jobs == -1));
if (!defined($pid = open(ATRM, "-|"))) {
die("creating pipe to atrm: $!\n");
} elsif ($pid == 0) {
exec($path_atrm, $user, @jobs);
}
while(defined($_ = <ATRM>)) {
$txt .= $_;
}
close ATRM;
return $txt;
}
sub remove_at_jobs {
my($user) = (shift || "");
my(@at, $atrm);
return 1 if ($user eq "");
@at = invoke_atq($user);
return 0 if ($#at == -1);
print STDERR "Removing user's at jobs:";
print STDERR " @at:";
$atrm = invoke_atrm($user, @at);
if ($atrm ne "") {
print STDERR " -- $atrm\n";
return 1;
}
print STDERR " done.\n";
return 0;
}
sub resolvelink {
local($path) = @_;
local($l);
while (-l $path && -e $path) {
if (!defined($l = readlink($path))) {
die "${whoami}: readlink on $path failed (but it should have worked!): $!\n";
}
if ($l =~ /^\//) {
# Absolute link
$path = $l;
} else {
# Relative link
$path =~ s/\/[^\/]+\/?$/\/$l/; # Replace last component of path
}
}
return $path;
}
sub kill_users_processes {
local($login_name, $uid) = @_;
local($pid, $result);
#
# Do something a little complex: fork a child that changes its
# real and effective UID to that of the removed user, then issues
# a "kill(9, -1)" to kill all processes of the same uid as the sender
# (see kill(2) for details).
# The parent waits for the exit of the child and then returns.
if ($pid = fork) {
# Parent process
waitpid($pid, 0);
} elsif (defined $pid) {
# Child process
$< = $uid;
$> = $uid;
if ($< != $uid || $> != $uid) {
print STDERR "${whoami}: Error (kill_users_processes):\n" .
"\tCouldn't reset uid/euid to ${uid}: current uid/euid's are $< and $>\n";
exit 1;
}
$result = kill(9, -1);
print STDERR "Killed process(es) belonging to $login_name.\n"
if $result;
exit 0;
} else {
# Couldn't fork!
print STDERR "${whoami}: Error: couldn't fork to kill ${login_name}'s processes - continuing\n";
}
}