adduser/rmuser.perl

   1 #!/usr/bin/perl
   2 # -*- perl -*-
   3 # Copyright 1995, 1996, 1997 Guy Helmer, Ames, Iowa 50014.
   4 # All rights reserved.
   5 #
   6 # Redistribution and use in source and binary forms, with or without
   7 # modification, are permitted provided that the following conditions
   8 # are met:
   9 # 1. Redistributions of source code must retain the above copyright
  10 #    notice, this list of conditions and the following disclaimer as
  11 #    the first lines of this file unmodified.
  12 # 2. Redistributions in binary form must reproduce the above copyright
  13 #    notice, this list of conditions and the following disclaimer in the
  14 #    documentation and/or other materials provided with the distribution.
  15 # 3. The name of the author may not be used to endorse or promote products
  16 #    derived from this software without specific prior written permission.
  17 #
  18 # THIS SOFTWARE IS PROVIDED BY GUY HELMER ``AS IS'' AND ANY EXPRESS OR
  19 # IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  20 # OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  21 # IN NO EVENT SHALL GUY HELMER BE LIABLE FOR ANY DIRECT, INDIRECT,
  22 # INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  23 # NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  24 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  25 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  26 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  27 # THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28 #
  29 # rmuser - Perl script to remove users
  30 #
  31 # Guy Helmer <ghelmer@cs.iastate.edu>, 02/23/97
  32 #
  33 # $FreeBSD$
  34
  35 sub LOCK_SH {0x01;}
  36 sub LOCK_EX {0x02;}
  37 sub LOCK_NB {0x04;}
  38 sub LOCK_UN {0x08;}
  39 sub F_SETFD {2;}
  40
  41 $ENV{"PATH"} = "/bin:/sbin:/usr/bin:/usr/sbin";
  42 umask(022);
  43 $whoami = $0;
  44 $passwd_file = "/etc/master.passwd";
  45 $new_passwd_file = "${passwd_file}.new.$$";
  46 $group_file = "/etc/group";
  47 $new_group_file = "${group_file}.new.$$";
  48 $mail_dir = "/var/mail";
  49 $crontab_dir = "/var/cron/tabs";
  50 $atjob_dir = "/var/at/jobs";
  51 $affirm = 0;
  52
  53 #$debug = 1;
  54
  55 sub cleanup {
  56     local($sig) = @_;
  57
  58     print STDERR "Caught signal SIG$sig -- cleaning up.\n";
  59     &unlockpw;
  60     if (-e $new_passwd_file) {
  61         unlink $new_passwd_file;
  62     }
  63     exit(0);
  64 }
  65
  66 sub lockpw {
  67     # Open the password file for reading
  68     if (!open(MASTER_PW, "$passwd_file")) {
  69         print STDERR "${whoami}: Error: Couldn't open ${passwd_file}: $!\n";
  70         exit(1);
  71     }
  72     # Set the close-on-exec flag just in case
  73     fcntl(MASTER_PW, &F_SETFD, 1);
  74     # Apply an advisory lock the password file
  75     if (!flock(MASTER_PW, &LOCK_EX|&LOCK_NB)) {
  76         print STDERR "${whoami}: Error: Couldn't lock ${passwd_file}: $!\n";
  77         exit(1);
  78     }
  79 }
  80
  81 sub unlockpw {
  82     flock(MASTER_PW, &LOCK_UN);
  83 }
  84
  85 $SIG{'INT'} = 'cleanup';
  86 $SIG{'QUIT'} = 'cleanup';
  87 $SIG{'HUP'} = 'cleanup';
  88 $SIG{'TERM'} = 'cleanup';
  89
  90 if ($#ARGV == 1 && $ARGV[0] eq '-y') {
  91     shift @ARGV;
  92     $affirm = 1;
  93 }
  94
  95 if ($#ARGV > 0) {
  96     print STDERR "usage: ${whoami} [-y] [username]\n";
  97     exit(1);
  98 }
  99
 100 if ($< != 0) {
 101     print STDERR "${whoami}: Error: you must be root to use ${whoami}\n";
 102     exit(1);
 103 }
 104
 105 &lockpw;
 106
 107 if ($#ARGV == 0) {
 108     # Username was given as a parameter
 109     $login_name = pop(@ARGV);
 110 } else {
 111     if ($affirm) {
 112         print STDERR "${whoami}: Error: -y option given without username!\n";
 113         &unlockpw;
 114         exit 1;
 115     }
 116     # Get the user name from the user
 117     $login_name = &get_login_name;
 118 }
 119
 120 ($name, $password, $uid, $gid, $change, $class, $gecos, $home_dir, $shell) =
 121     (getpwnam("$login_name"));
 122
 123 if ($?) {
 124     print STDERR "${whoami}: Error: User ${login_name} not in password database\n";
 125     &unlockpw;
 126     exit 1;
 127 }
 128
 129 if ($uid == 0) {
 130     print "${whoami}: Error: I'd rather not remove a user with a uid of 0.\n";
 131     &unlockpw;
 132     exit 1;
 133 }
 134
 135 if (! $affirm) {
 136     print "Matching password entry:\n\n$name\:$password\:$uid\:$gid\:$class\:$change\:0\:$gecos\:$home_dir\:$shell\n\n";
 137
 138     $ans = &get_yn("Is this the entry you wish to remove? ");
 139
 140     if ($ans eq 'N') {
 141         print "${whoami}: Informational: User ${login_name} not removed.\n";
 142         &unlockpw;
 143         exit 0;
 144     }
 145 }
 146
 147 #
 148 # Get owner of user's home directory; don't remove home dir if not
 149 # owned by $login_name
 150
 151 $remove_directory = 1;
 152
 153 if (-l $home_dir) {
 154     $real_home_dir = &resolvelink($home_dir);
 155 } else {
 156     $real_home_dir = $home_dir;
 157 }
 158
 159 #
 160 # If home_dir is a symlink and points to something that isn't a directory,
 161 # or if home_dir is not a symlink and is not a directory, don't remove
 162 # home_dir -- seems like a good thing to do, but probably isn't necessary...
 163
 164 if (((-l $home_dir) && ((-e $real_home_dir) && !(-d $real_home_dir))) ||
 165     (!(-l $home_dir) && !(-d $home_dir))) {
 166     print STDERR "${whoami}: Informational: Home ${home_dir} is not a directory, so it won't be removed\n";
 167     $remove_directory = 0;
 168 }
 169
 170 if (length($real_home_dir) && -d $real_home_dir) {
 171     $dir_owner = (stat($real_home_dir))[4]; # UID
 172     if ($dir_owner != $uid) {
 173         print STDERR "${whoami}: Informational: Home dir ${real_home_dir} is" .
 174             " not owned by ${login_name} (uid ${dir_owner})\n," .
 175                 "\tso it won't be removed\n";
 176         $remove_directory = 0;
 177     }
 178 }
 179
 180 if ($remove_directory && ! $affirm) {
 181     $ans = &get_yn("Remove user's home directory ($home_dir)? ");
 182     if ($ans eq 'N') {
 183         $remove_directory = 0;
 184     }
 185 }
 186
 187 #exit 0 if $debug;
 188
 189 #
 190 # Remove the user's crontab, if there is one
 191 # (probably needs to be done before password databases are updated)
 192
 193 if (-e "$crontab_dir/$login_name") {
 194     print STDERR "Removing user's crontab:";
 195     system('/usr/bin/crontab', '-u', $login_name, '-r');
 196     print STDERR " done.\n";
 197 }
 198
 199 #
 200 # Remove the user's at jobs, if any
 201 # (probably also needs to be done before password databases are updated)
 202
 203 &remove_at_jobs($login_name, $uid);
 204
 205 #
 206 # Kill all the user's processes
 207
 208 &kill_users_processes($login_name, $uid);
 209
 210 #
 211 # Copy master password file to new file less removed user's entry
 212
 213 &update_passwd_file;
 214
 215 #
 216 # Remove the user from all groups in /etc/group
 217
 218 &update_group_file($login_name);
 219
 220 #
 221 # Remove the user's home directory
 222
 223 if ($remove_directory) {
 224     print STDERR "Removing user's home directory ($home_dir):";
 225     &remove_dir($home_dir);
 226     print STDERR " done.\n";
 227 }
 228
 229 #
 230 # Remove files related to the user from the mail directory
 231
 232 #&remove_files_from_dir($mail_dir, $login_name, $uid);
 233 $file = "$mail_dir/$login_name";
 234 if (-e $file || -l $file) {
 235     print STDERR "Removing user's incoming mail file ${file}:";
 236     unlink $file ||
 237         print STDERR "\n${whoami}: Warning: unlink on $file failed ($!) - continuing\n";
 238     print STDERR " done.\n";
 239 }
 240
 241 #
 242 # Remove some pop daemon's leftover file
 243
 244 $file = "$mail_dir/.${login_name}.pop";
 245 if (-e $file || -l $file) {
 246     print STDERR "Removing pop daemon's temporary mail file ${file}:";
 247     unlink $file ||
 248         print STDERR "\n${whoami}: Warning: unlink on $file failed ($!) - continuing\n";
 249     print STDERR " done.\n";
 250 }
 251
 252 #
 253 # Remove files belonging to the user from the directories /tmp, /var/tmp,
 254 # and /var/tmp/vi.recover.  Note that this doesn't take care of the
 255 # problem where a user may have directories or symbolic links in those
 256 # directories -- only regular files are removed.
 257
 258 &remove_files_from_dir('/tmp', $login_name, $uid);
 259 &remove_files_from_dir('/var/tmp', $login_name, $uid);
 260 &remove_files_from_dir('/var/tmp/vi.recover', $login_name, $uid)
 261     if (-e '/var/tmp/vi.recover');
 262
 263 #
 264 # All done!
 265
 266 exit 0;
 267
 268 sub get_login_name {
 269     #
 270     # Get new user's name
 271     local($done, $login_name);
 272
 273     for ($done = 0; ! $done; ) {
 274         print "Enter login name for user to remove: ";
 275         $login_name = <>;
 276         chomp $login_name;
 277         if (not getpwnam("$login_name")) {
 278             print STDERR "Sorry, login name not in password database.\n";
 279         } else {
 280             $done = 1;
 281         }
 282     }
 283
 284     print "User name is ${login_name}\n" if $debug;
 285     return($login_name);
 286 }
 287
 288 sub get_yn {
 289     #
 290     # Get a yes or no answer; return 'Y' or 'N'
 291     local($prompt) = @_;
 292     local($done, $ans);
 293
 294     for ($done = 0; ! $done; ) {
 295         print $prompt;
 296         $ans = <>;
 297         chop $ans;
 298         $ans =~ tr/a-z/A-Z/;
 299         if (!($ans =~ /^[YN]/)) {
 300             print STDERR "Please answer (y)es or (n)o.\n";
 301         } else {
 302             $done = 1;
 303         }
 304     }
 305
 306     return(substr($ans, 0, 1));
 307 }
 308
 309 sub update_passwd_file {
 310     local($skipped);
 311
 312     print STDERR "Updating password file,";
 313     seek(MASTER_PW, 0, 0);
 314     open(NEW_PW, ">$new_passwd_file") ||
 315         die "\n${whoami}: Error: Couldn't open file ${new_passwd_file}:\n $!\n";
 316     chmod(0600, $new_passwd_file) ||
 317         print STDERR "\n${whoami}: Warning: couldn't set mode of $new_passwd_file to 0600 ($!)\n\tcontinuing, but please check mode of /etc/master.passwd!\n";
 318     $skipped = 0;
 319     while (<MASTER_PW>) {
 320         if (not /^\Q$login_name:/io) {
 321             print NEW_PW;
 322         } else {
 323             print STDERR "Dropped entry for $login_name\n" if $debug;
 324             $skipped = 1;
 325         }
 326     }
 327     close(NEW_PW);
 328     seek(MASTER_PW, 0, 0);
 329
 330     if ($skipped == 0) {
 331         print STDERR "\n${whoami}: Whoops! Didn't find ${login_name}'s entry second time around!\n";
 332         unlink($new_passwd_file) ||
 333             print STDERR "\n${whoami}: Warning: couldn't unlink $new_passwd_file ($!)\n\tPlease investigate, as this file should not be left in the filesystem\n";
 334         &unlockpw;
 335         exit 1;
 336     }
 337
 338     #
 339     # Run pwd_mkdb to install the updated password files and databases
 340
 341     print STDERR " updating databases,";
 342     system('/usr/sbin/pwd_mkdb', '-p', ${new_passwd_file});
 343     print STDERR " done.\n";
 344
 345     close(MASTER_PW);           # Not useful anymore
 346 }
 347
 348 sub update_group_file {
 349     local($login_name) = @_;
 350
 351     local($i, $j, $grmember_list, $new_grent, $changes);
 352     local($grname, $grpass, $grgid, $grmember_list, @grmembers);
 353
 354     $changes = 0;
 355     print STDERR "Updating group file:";
 356     open(GROUP, $group_file) ||
 357         die "\n${whoami}: Error: couldn't open ${group_file}: $!\n";
 358     if (!flock(GROUP, &LOCK_EX|&LOCK_NB)) {
 359         print STDERR "\n${whoami}: Error: couldn't lock ${group_file}: $!\n";
 360         exit 1;
 361     }
 362     local($group_perms, $group_uid, $group_gid) =
 363         (stat(GROUP))[2, 4, 5]; # File Mode, uid, gid
 364     open(NEW_GROUP, ">$new_group_file") ||
 365         die "\n${whoami}: Error: couldn't open ${new_group_file}: $!\n";
 366     chmod($group_perms, $new_group_file) ||
 367         printf STDERR "\n${whoami}: Warning: could not set permissions of new group file to %o ($!)\n\tContinuing, but please check permissions of $group_file!\n", $group_perms;
 368     chown($group_uid, $group_gid, $new_group_file) ||
 369         print STDERR "\n${whoami}: Warning: could not set owner/group of new group file to ${group_uid}/${group_gid} ($!)\n\rContinuing, but please check ownership of $group_file!\n";
 370     while ($i = <GROUP>) {
 371         if (!($i =~ /$login_name/)) {
 372             # Line doesn't contain any references to the user, so just add it
 373             # to the new file
 374             print NEW_GROUP $i;
 375         } else {
 376             #
 377             # Remove the user from the group
 378             if ($i =~ /\n$/) {
 379                 chop $i;
 380             }
 381             ($grname, $grpass, $grgid, $grmember_list) = split(/:/, $i);
 382             @grmembers = split(/,/, $grmember_list);
 383             undef @new_grmembers;
 384             local(@new_grmembers);
 385             foreach $j (@grmembers) {
 386                 if ($j ne $login_name) {
 387                     push(@new_grmembers, $j);
 388                 } else {
 389                     print STDERR " $grname";
 390                     $changes = 1;
 391                 }
 392             }
 393             if ($grname eq $login_name && $#new_grmembers == -1) {
 394                 # Remove a user's personal group if empty
 395                 print STDERR " (removing group $grname -- personal group is empty)";
 396                 $changes = 1;
 397             } else {
 398                 $grmember_list = join(',', @new_grmembers);
 399                 $new_grent = join(':', $grname, $grpass, $grgid, $grmember_list);
 400                 print NEW_GROUP "$new_grent\n";
 401             }
 402         }
 403     }
 404     close(NEW_GROUP);
 405     rename($new_group_file, $group_file) || # Replace old group file with new
 406         die "\n${whoami}: Error: couldn't rename $new_group_file to $group_file ($!)\n";
 407     close(GROUP);                       # File handle is worthless now
 408     print STDERR " (no changes)" if (! $changes);
 409     print STDERR " done.\n";
 410 }
 411
 412 sub remove_dir {
 413     # Remove the user's home directory
 414     local($dir) = @_;
 415     local($linkdir);
 416
 417     if (-l $dir) {
 418         $linkdir = &resolvelink($dir);
 419         # Remove the symbolic link
 420         unlink($dir) ||
 421             warn "${whoami}: Warning: could not unlink symlink $dir: $!\n";
 422         if (!(-e $linkdir)) {
 423             #
 424             # Dangling symlink - just return now
 425             return;
 426         }
 427         # Set dir to be the resolved pathname
 428         $dir = $linkdir;
 429     }
 430     if (!(-d $dir)) {
 431         print STDERR "${whoami}: Warning: $dir is not a directory\n";
 432         unlink($dir) || warn "${whoami}: Warning: could not unlink $dir: $!\n";
 433         return;
 434     }
 435     system('/bin/rm', '-rf', $dir);
 436 }
 437
 438 sub remove_files_from_dir {
 439     local($dir, $login_name, $uid) = @_;
 440     local($path, $i, $owner);
 441
 442     print STDERR "Removing files belonging to ${login_name} from ${dir}:";
 443
 444     if (!opendir(DELDIR, $dir)) {
 445         print STDERR "\n${whoami}: Warning: couldn't open directory ${dir} ($!)\n";
 446         return;
 447     }
 448     while ($i = readdir(DELDIR)) {
 449         next if $i eq '.';
 450         next if $i eq '..';
 451
 452         $owner = (stat("$dir/$i"))[4]; # UID
 453         if ($uid == $owner) {
 454             if (-f "$dir/$i") {
 455                 print STDERR " $i";
 456                 unlink "$dir/$i" ||
 457                     print STDERR "\n${whoami}: Warning: unlink on ${dir}/${i} failed ($!) - continuing\n";
 458             } else {
 459                 print STDERR " ($i not a regular file - skipped)";
 460             }
 461         }
 462     }
 463     closedir(DELDIR);
 464
 465     printf STDERR " done.\n";
 466 }
 467
 468 sub remove_at_jobs {
 469     local($login_name, $uid) = @_;
 470     local($i, $owner, $found);
 471
 472     $found = 0;
 473     opendir(ATDIR, $atjob_dir) || return;
 474     while ($i = readdir(ATDIR)) {
 475         next if $i eq '.';
 476         next if $i eq '..';
 477         next if $i eq '.lockfile';
 478
 479         $owner = (stat("$atjob_dir/$i"))[4]; # UID
 480         if ($uid == $owner) {
 481             if (!$found) {
 482                 print STDERR "Removing user's at jobs:";
 483                 $found = 1;
 484             }
 485             # Use atrm to remove the job
 486             print STDERR " $i";
 487             system('/usr/bin/atrm', $i);
 488         }
 489     }
 490     closedir(ATDIR);
 491     if ($found) {
 492         print STDERR " done.\n";
 493     }
 494 }
 495
 496 sub resolvelink {
 497     local($path) = @_;
 498     local($l);
 499
 500     while (-l $path && -e $path) {
 501         if (!defined($l = readlink($path))) {
 502             die "${whoami}: readlink on $path failed (but it should have worked!): $!\n";
 503         }
 504         if ($l =~ /^\//) {
 505             # Absolute link
 506             $path = $l;
 507         } else {
 508             # Relative link
 509             $path =~ s/\/[^\/]+\/?$/\/$l/; # Replace last component of path
 510         }
 511     }
 512     return $path;
 513 }
 514
 515 sub kill_users_processes {
 516     local($login_name, $uid) = @_;
 517     local($pid, $result);
 518
 519     #
 520     # Do something a little complex: fork a child that changes its
 521     # real and effective UID to that of the removed user, then issues
 522     # a "kill(9, -1)" to kill all processes of the same uid as the sender
 523     # (see kill(2) for details).
 524     # The parent waits for the exit of the child and then returns.
 525
 526     if ($pid = fork) {
 527         # Parent process
 528         waitpid($pid, 0);
 529     } elsif (defined $pid) {
 530         # Child process
 531         $< = $uid;
 532         $> = $uid;
 533         if ($< != $uid || $> != $uid) {
 534             print STDERR "${whoami}: Error (kill_users_processes):\n" .
 535                 "\tCouldn't reset uid/euid to ${uid}: current uid/euid's are $< and $>\n";
 536             exit 1;
 537         }
 538         $result = kill(9, -1);
 539         print STDERR "Killed process(es) belonging to $login_name.\n"
 540             if $result;
 541         exit 0;
 542     } else {
 543         # Couldn't fork!
 544         print STDERR "${whoami}: Error: couldn't fork to kill ${login_name}'s processes - continuing\n";
 545     }
 546 }