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 use Fcntl;
  36
  37 sub LOCK_SH {0x01;}
  38 sub LOCK_EX {0x02;}
  39 sub LOCK_NB {0x04;}
  40 sub LOCK_UN {0x08;}
  41 sub F_SETFD {2;}
  42
  43 $ENV{"PATH"} = "/bin:/sbin:/usr/bin:/usr/sbin";
  44 umask(022);
  45 $whoami = $0;
  46 $passwd_file = "/etc/master.passwd";
  47 $passwd_tmp = "/etc/ptmp";
  48 $group_file = "/etc/group";
  49 $new_group_file = "${group_file}.new.$$";
  50 $mail_dir = "/var/mail";
  51 $crontab_dir = "/var/cron/tabs";
  52 $affirm = 0;
  53
  54 #$debug = 1;
  55
  56 sub cleanup {
  57     local($sig) = @_;
  58
  59     print STDERR "Caught signal SIG$sig -- cleaning up.\n";
  60     &unlockpw;
  61     if (-e $new_passwd_file) {
  62         unlink $new_passwd_file;
  63     }
  64     exit(0);
  65 }
  66
  67 sub lockpw {
  68     # Open the password file for reading
  69     if (!open(MASTER_PW, "$passwd_file")) {
  70         print STDERR "${whoami}: Error: Couldn't open ${passwd_file}: $!\n";
  71         exit(1);
  72     }
  73     # Set the close-on-exec flag just in case
  74     fcntl(MASTER_PW, &F_SETFD, 1);
  75     # Apply an advisory lock the password file
  76     if (!flock(MASTER_PW, &LOCK_EX|&LOCK_NB)) {
  77         print STDERR "${whoami}: Error: Couldn't lock ${passwd_file}: $!\n";
  78         exit(1);
  79     }
  80 }
  81
  82 sub unlockpw {
  83     flock(MASTER_PW, &LOCK_UN);
  84 }
  85
  86 $SIG{'INT'} = 'cleanup';
  87 $SIG{'QUIT'} = 'cleanup';
  88 $SIG{'HUP'} = 'cleanup';
  89 $SIG{'TERM'} = 'cleanup';
  90
  91 if ($#ARGV == 1 && $ARGV[0] eq '-y') {
  92     shift @ARGV;
  93     $affirm = 1;
  94 }
  95
  96 if ($#ARGV > 0) {
  97     print STDERR "usage: ${whoami} [-y] [username]\n";
  98     exit(1);
  99 }
 100
 101 if ($< != 0) {
 102     print STDERR "${whoami}: Error: you must be root to use ${whoami}\n";
 103     exit(1);
 104 }
 105
 106 &lockpw;
 107
 108 if ($#ARGV == 0) {
 109     # Username was given as a parameter
 110     $login_name = pop(@ARGV);
 111 } else {
 112     if ($affirm) {
 113         print STDERR "${whoami}: Error: -y option given without username!\n";
 114         &unlockpw;
 115         exit 1;
 116     }
 117     # Get the user name from the user
 118     $login_name = &get_login_name;
 119 }
 120
 121 ($name, $password, $uid, $gid, $change, $class, $gecos, $home_dir, $shell) =
 122     (getpwnam("$login_name"));
 123
 124 if (!defined $uid) {
 125     print STDERR "${whoami}: Error: User ${login_name} not in password database\n";
 126     &unlockpw;
 127     exit 1;
 128 }
 129
 130 if ($uid == 0) {
 131     print "${whoami}: Error: I'd rather not remove a user with a uid of 0.\n";
 132     &unlockpw;
 133     exit 1;
 134 }
 135
 136 if (! $affirm) {
 137     print "Matching password entry:\n\n$name\:$password\:$uid\:$gid\:$class\:$change\:0\:$gecos\:$home_dir\:$shell\n\n";
 138
 139     $ans = &get_yn("Is this the entry you wish to remove? ");
 140
 141     if ($ans eq 'N') {
 142         print "${whoami}: Informational: User ${login_name} not removed.\n";
 143         &unlockpw;
 144         exit 0;
 145     }
 146 }
 147
 148 #
 149 # Get owner of user's home directory; don't remove home dir if not
 150 # owned by $login_name
 151
 152 $remove_directory = 1;
 153
 154 if (-l $home_dir) {
 155     $real_home_dir = &resolvelink($home_dir);
 156 } else {
 157     $real_home_dir = $home_dir;
 158 }
 159
 160 #
 161 # If home_dir is a symlink and points to something that isn't a directory,
 162 # or if home_dir is not a symlink and is not a directory, don't remove
 163 # home_dir -- seems like a good thing to do, but probably isn't necessary...
 164
 165 if (((-l $home_dir) && ((-e $real_home_dir) && !(-d $real_home_dir))) ||
 166     (!(-l $home_dir) && !(-d $home_dir))) {
 167     print STDERR "${whoami}: Informational: Home ${home_dir} is not a directory, so it won't be removed\n";
 168     $remove_directory = 0;
 169 }
 170
 171 if (length($real_home_dir) && -d $real_home_dir) {
 172     $dir_owner = (stat($real_home_dir))[4]; # UID
 173     if ($dir_owner != $uid) {
 174         print STDERR "${whoami}: Informational: Home dir ${real_home_dir} is" .
 175             " not owned by ${login_name} (uid ${dir_owner})\n," .
 176                 "\tso it won't be removed\n";
 177         $remove_directory = 0;
 178     }
 179 }
 180
 181 if ($remove_directory && ! $affirm) {
 182     $ans = &get_yn("Remove user's home directory ($home_dir)? ");
 183     if ($ans eq 'N') {
 184         $remove_directory = 0;
 185     }
 186 }
 187
 188 #exit 0 if $debug;
 189
 190 #
 191 # Remove the user's crontab, if there is one
 192 # (probably needs to be done before password databases are updated)
 193
 194 if (-e "$crontab_dir/$login_name") {
 195     print STDERR "Removing user's crontab:";
 196     system('/usr/bin/crontab', '-u', $login_name, '-r');
 197     print STDERR " done.\n";
 198 }
 199
 200 #
 201 # Remove the user's at jobs, if any
 202 # (probably also needs to be done before password databases are updated)
 203
 204 &remove_at_jobs($login_name);
 205
 206 #
 207 # Kill all the user's processes
 208
 209 &kill_users_processes($login_name, $uid);
 210
 211 #
 212 # Copy master password file to new file less removed user's entry
 213
 214 &update_passwd_file;
 215
 216 #
 217 # Remove the user from all groups in /etc/group
 218
 219 &update_group_file($login_name);
 220
 221 #
 222 # Remove the user's home directory
 223
 224 if ($remove_directory) {
 225     print STDERR "Removing user's home directory ($home_dir):";
 226     &remove_dir($home_dir);
 227     print STDERR " done.\n";
 228 }
 229
 230 #
 231 # Remove files related to the user from the mail directory
 232
 233 #&remove_files_from_dir($mail_dir, $login_name, $uid);
 234 $file = "$mail_dir/$login_name";
 235 if (-e $file || -l $file) {
 236     print STDERR "Removing user's incoming mail file ${file}:";
 237     unlink $file ||
 238         print STDERR "\n${whoami}: Warning: unlink on $file failed ($!) - continuing\n";
 239     print STDERR " done.\n";
 240 }
 241
 242 #
 243 # Remove some pop daemon's leftover file
 244
 245 $file = "$mail_dir/.${login_name}.pop";
 246 if (-e $file || -l $file) {
 247     print STDERR "Removing pop daemon's temporary mail file ${file}:";
 248     unlink $file ||
 249         print STDERR "\n${whoami}: Warning: unlink on $file failed ($!) - continuing\n";
 250     print STDERR " done.\n";
 251 }
 252
 253 #
 254 # Remove files belonging to the user from the directories /tmp, /var/tmp,
 255 # and /var/tmp/vi.recover.  Note that this doesn't take care of the
 256 # problem where a user may have directories or symbolic links in those
 257 # directories -- only regular files are removed.
 258
 259 &remove_files_from_dir('/tmp', $login_name, $uid);
 260 &remove_files_from_dir('/var/tmp', $login_name, $uid);
 261 &remove_files_from_dir('/var/tmp/vi.recover', $login_name, $uid)
 262     if (-e '/var/tmp/vi.recover');
 263
 264 #
 265 # All done!
 266
 267 exit 0;
 268
 269 sub get_login_name {
 270     #
 271     # Get new user's name
 272     local($done, $login_name);
 273
 274     for ($done = 0; ! $done; ) {
 275         print "Enter login name for user to remove: ";
 276         $login_name = <>;
 277         chomp $login_name;
 278         if (not getpwnam("$login_name")) {
 279             print STDERR "Sorry, login name not in password database.\n";
 280         } else {
 281             $done = 1;
 282         }
 283     }
 284
 285     print "User name is ${login_name}\n" if $debug;
 286     return($login_name);
 287 }
 288
 289 sub get_yn {
 290     #
 291     # Get a yes or no answer; return 'Y' or 'N'
 292     local($prompt) = @_;
 293     local($done, $ans);
 294
 295     for ($done = 0; ! $done; ) {
 296         print $prompt;
 297         $ans = <>;
 298         chop $ans;
 299         $ans =~ tr/a-z/A-Z/;
 300         if (!($ans =~ /^[YN]/)) {
 301             print STDERR "Please answer (y)es or (n)o.\n";
 302         } else {
 303             $done = 1;
 304         }
 305     }
 306
 307     return(substr($ans, 0, 1));
 308 }
 309
 310 sub update_passwd_file {
 311     local($skipped);
 312
 313     print STDERR "Updating password file,";
 314     seek(MASTER_PW, 0, 0);
 315
 316     sysopen(NEW_PW, $passwd_tmp, O_RDWR|O_CREAT|O_EXCL, 0600) ||
 317         die "\n${whoami}: Error: Couldn't open file ${passwd_tmp}:\n $!\n";
 318
 319     $skipped = 0;
 320     while (<MASTER_PW>) {
 321         if (/^\Q$login_name:/o) {
 322             print STDERR "Dropped entry for $login_name\n" if $debug;
 323             $skipped = 1;
 324         } else {
 325             print NEW_PW;
 326             # The other perl password tools assume all lowercase entries.
 327             # Add a warning to help unsuspecting admins who might be
 328             # using the wrong tool for the job, or might otherwise
 329             # be unwittingly holding a loaded foot-shooting device.
 330             if (/^\Q$login_name:/io) {
 331                 my $name = $_;
 332                 $name =~ s#\:.*\n##;
 333                 print STDERR "\n\n\tThere is also an entry for $name in your",
 334                     "password file.\n\tThis can cause problems in some ",
 335                     "situations.\n\n";
 336             }
 337         }
 338     }
 339     close(NEW_PW);
 340     seek(MASTER_PW, 0, 0);
 341
 342     if ($skipped == 0) {
 343         print STDERR "\n${whoami}: Whoops! Didn't find ${login_name}'s entry second time around!\n";
 344         unlink($passwd_tmp) ||
 345             print STDERR "\n${whoami}: Warning: couldn't unlink $passwd_tmp ($!)\n\tPlease investigate, as this file should not be left in the filesystem\n";
 346         &unlockpw;
 347         exit 1;
 348     }
 349
 350     #
 351     # Run pwd_mkdb to install the updated password files and databases
 352
 353     print STDERR " updating databases,";
 354     system('/usr/sbin/pwd_mkdb', '-p', ${passwd_tmp});
 355     print STDERR " done.\n";
 356
 357     close(MASTER_PW);           # Not useful anymore
 358 }
 359
 360 sub update_group_file {
 361     local($login_name) = @_;
 362
 363     local($i, $j, $grmember_list, $new_grent, $changes);
 364     local($grname, $grpass, $grgid, $grmember_list, @grmembers);
 365
 366     $changes = 0;
 367     print STDERR "Updating group file:";
 368     open(GROUP, $group_file) ||
 369         die "\n${whoami}: Error: couldn't open ${group_file}: $!\n";
 370     if (!flock(GROUP, &LOCK_EX|&LOCK_NB)) {
 371         print STDERR "\n${whoami}: Error: couldn't lock ${group_file}: $!\n";
 372         exit 1;
 373     }
 374     local($group_perms, $group_uid, $group_gid) =
 375         (stat(GROUP))[2, 4, 5]; # File Mode, uid, gid
 376     open(NEW_GROUP, ">$new_group_file") ||
 377         die "\n${whoami}: Error: couldn't open ${new_group_file}: $!\n";
 378     chmod($group_perms, $new_group_file) ||
 379         printf STDERR "\n${whoami}: Warning: could not set permissions of new group file to %o ($!)\n\tContinuing, but please check permissions of $group_file!\n", $group_perms;
 380     chown($group_uid, $group_gid, $new_group_file) ||
 381         print STDERR "\n${whoami}: Warning: could not set owner/group of new group file to ${group_uid}/${group_gid} ($!)\n\rContinuing, but please check ownership of $group_file!\n";
 382     while ($i = <GROUP>) {
 383         if (!($i =~ /\Q$login_name\E/)) {
 384             # Line doesn't contain any references to the user, so just add it
 385             # to the new file
 386             print NEW_GROUP $i;
 387         } else {
 388             #
 389             # Remove the user from the group
 390             if ($i =~ /\n$/) {
 391                 chop $i;
 392             }
 393             ($grname, $grpass, $grgid, $grmember_list) = split(/:/, $i);
 394             @grmembers = split(/,/, $grmember_list);
 395             undef @new_grmembers;
 396             local(@new_grmembers);
 397             foreach $j (@grmembers) {
 398                 if ($j ne $login_name) {
 399                     push(@new_grmembers, $j);
 400                 } else {
 401                     print STDERR " $grname";
 402                     $changes = 1;
 403                 }
 404             }
 405             if ($grname eq $login_name && $#new_grmembers == -1) {
 406                 # Remove a user's personal group if empty
 407                 print STDERR " (removing group $grname -- personal group is empty)";
 408                 $changes = 1;
 409             } else {
 410                 $grmember_list = join(',', @new_grmembers);
 411                 $new_grent = join(':', $grname, $grpass, $grgid, $grmember_list);
 412                 print NEW_GROUP "$new_grent\n";
 413             }
 414         }
 415     }
 416     close(NEW_GROUP);
 417     rename($new_group_file, $group_file) || # Replace old group file with new
 418         die "\n${whoami}: Error: couldn't rename $new_group_file to $group_file ($!)\n";
 419     close(GROUP);                       # File handle is worthless now
 420     print STDERR " (no changes)" if (! $changes);
 421     print STDERR " done.\n";
 422 }
 423
 424 sub remove_dir {
 425     # Remove the user's home directory
 426     local($dir) = @_;
 427     local($linkdir);
 428
 429     if (-l $dir) {
 430         $linkdir = &resolvelink($dir);
 431         # Remove the symbolic link
 432         unlink($dir) ||
 433             warn "${whoami}: Warning: could not unlink symlink $dir: $!\n";
 434         if (!(-e $linkdir)) {
 435             #
 436             # Dangling symlink - just return now
 437             return;
 438         }
 439         # Set dir to be the resolved pathname
 440         $dir = $linkdir;
 441     }
 442     if (!(-d $dir)) {
 443         print STDERR "${whoami}: Warning: $dir is not a directory\n";
 444         unlink($dir) || warn "${whoami}: Warning: could not unlink $dir: $!\n";
 445         return;
 446     }
 447     system('/bin/rm', '-rf', $dir);
 448 }
 449
 450 sub remove_files_from_dir {
 451     local($dir, $login_name, $uid) = @_;
 452     local($path, $i, $owner);
 453
 454     print STDERR "Removing files belonging to ${login_name} from ${dir}:";
 455
 456     if (!opendir(DELDIR, $dir)) {
 457         print STDERR "\n${whoami}: Warning: couldn't open directory ${dir} ($!)\n";
 458         return;
 459     }
 460     while ($i = readdir(DELDIR)) {
 461         next if $i eq '.';
 462         next if $i eq '..';
 463
 464         $owner = (stat("$dir/$i"))[4]; # UID
 465         if ($uid == $owner) {
 466             if (-f "$dir/$i") {
 467                 print STDERR " $i";
 468                 unlink "$dir/$i" ||
 469                     print STDERR "\n${whoami}: Warning: unlink on ${dir}/${i} failed ($!) - continuing\n";
 470             } else {
 471                 print STDERR " ($i not a regular file - skipped)";
 472             }
 473         }
 474     }
 475     closedir(DELDIR);
 476
 477     printf STDERR " done.\n";
 478 }
 479
 480
 481 sub invoke_atq {
 482     local *ATQ;
 483     my($user) = (shift || "");
 484     my($path_atq) = "/usr/bin/atq";
 485     my(@at) = ();
 486     my($pid, $line);
 487
 488     return @at if ($user eq "");
 489
 490     if (!defined($pid = open(ATQ, "-|"))) {
 491         die("creating pipe to atq: $!\n");
 492     } elsif ($pid == 0) {
 493         exec($path_atq, $user);
 494         die("executing $path_atq: $!\n");
 495     }
 496
 497     while(defined($_ = <ATQ>)) {
 498         chomp;
 499         if (/^\d\d.\d\d.\d\d\s+\d\d.\d\d.\d\d\s+(\S+)\s+\S+\s+(\d+)$/) {
 500             push(@at, $2) if ($1 eq $user);
 501         }
 502     }
 503     close ATQ;
 504     return @at;
 505 }
 506
 507 sub invoke_atrm {
 508     local *ATRM;
 509     my($user) = (shift || "");
 510     my($path_atrm) = "/usr/bin/atrm";
 511     my(@jobs) = @_;
 512     my($pid);
 513     my($txt) = "";
 514
 515     return "Invalid arguments" if (($user eq "") || ($#jobs == -1));
 516
 517     if (!defined($pid = open(ATRM, "-|"))) {
 518         die("creating pipe to atrm: $!\n");
 519     } elsif ($pid == 0) {
 520         exec($path_atrm, $user, @jobs);
 521     }
 522
 523     while(defined($_ = <ATRM>)) {
 524         $txt .= $_;
 525     }
 526     close ATRM;
 527     return $txt;
 528 }
 529
 530 sub remove_at_jobs {
 531     my($user) = (shift || "");
 532     my(@at, $atrm);
 533
 534     return 1 if ($user eq "");
 535
 536     @at = invoke_atq($user);
 537     return 0 if ($#at == -1);
 538
 539     print STDERR "Removing user's at jobs:";
 540     print STDERR " @at:";
 541     $atrm = invoke_atrm($user, @at);
 542     if ($atrm ne "") {
 543         print STDERR " -- $atrm\n";
 544         return 1;
 545     }
 546
 547     print STDERR " done.\n";
 548     return 0;
 549 }
 550
 551 sub resolvelink {
 552     local($path) = @_;
 553     local($l);
 554
 555     while (-l $path && -e $path) {
 556         if (!defined($l = readlink($path))) {
 557             die "${whoami}: readlink on $path failed (but it should have worked!): $!\n";
 558         }
 559         if ($l =~ /^\//) {
 560             # Absolute link
 561             $path = $l;
 562         } else {
 563             # Relative link
 564             $path =~ s/\/[^\/]+\/?$/\/$l/; # Replace last component of path
 565         }
 566     }
 567     return $path;
 568 }
 569
 570 sub kill_users_processes {
 571     local($login_name, $uid) = @_;
 572     local($pid, $result);
 573
 574     #
 575     # Do something a little complex: fork a child that changes its
 576     # real and effective UID to that of the removed user, then issues
 577     # a "kill(9, -1)" to kill all processes of the same uid as the sender
 578     # (see kill(2) for details).
 579     # The parent waits for the exit of the child and then returns.
 580
 581     if ($pid = fork) {
 582         # Parent process
 583         waitpid($pid, 0);
 584     } elsif (defined $pid) {
 585         # Child process
 586         $< = $uid;
 587         $> = $uid;
 588         if ($< != $uid || $> != $uid) {
 589             print STDERR "${whoami}: Error (kill_users_processes):\n" .
 590                 "\tCouldn't reset uid/euid to ${uid}: current uid/euid's are $< and $>\n";
 591             exit 1;
 592         }
 593         $result = kill(9, -1);
 594         print STDERR "Killed process(es) belonging to $login_name.\n"
 595             if $result;
 596         exit 0;
 597     } else {
 598         # Couldn't fork!
 599         print STDERR "${whoami}: Error: couldn't fork to kill ${login_name}'s processes - continuing\n";
 600     }
 601 }