Annotation of loncom/lcuserdel, revision 1.16
1.1 harris41 1: #!/usr/bin/perl
2: #
3: # lcuserdel
4: #
5:
6: use strict;
7:
1.16 ! albertel 8: # $Id: lond,v 1.378 2007/08/08 22:24:36 albertel Exp $
! 9:
1.2 harris41 10: # This script is a setuid script (chmod 6755) that should
1.1 harris41 11: # be run by user 'www'. It DOES NOT delete directories.
12: # All it does is remove a user's entries from
13: # /etc/passwd, /etc/groups, and /etc/smbpasswd.
1.5 harris41 14: # It also disables user directory access by making the directory
15: # to be owned by user=www (as opposed to the former "username").
16: # This command only returns an error if it is
17: # invoked incorrectly (by passing bad command-line arguments, etc).
1.1 harris41 18:
1.3 harris41 19: # This script works under the same process control mechanism
20: # as lcuseradd and lcpasswd, to make sure that only one of these
21: # processes is running at any one time on the system.
1.1 harris41 22:
23: # Standard input usage
24: # First line is USERNAME
25:
1.10 harris41 26: # Valid user names must consist of ascii
27: # characters that are alphabetical characters
28: # (A-Z,a-z), numeric (0-9), or the underscore
29: # mark (_). (Essentially, the perl regex \w).
30:
1.1 harris41 31: # Command-line arguments [USERNAME]
32: # Yes, but be very careful here (don't pass shell commands)
33: # and this is only supported to allow perl-system calls.
34:
1.2 harris41 35: # Usage within code
36: #
1.3 harris41 37: # $exitcode=system("/home/httpd/perl/lcuserdel","NAME")/256;
1.2 harris41 38: # print "uh-oh" if $exitcode;
39:
40: # These are the exit codes.
1.9 harris41 41: # ( (0,"ok"),
42: # (1,"User ID mismatch. This program must be run as user 'www'"),
1.11 harris41 43: # (2,"Error. This program needs just 1 command-line argument (username).") )
1.9 harris41 44: # (3,"Error. Only one line should be entered into standard input."),
1.11 harris41 45: # (4,"Error. Too many other simultaneous password change requests being made."),
46: # (5,"Error. The user name specified has invalid characters.") )
1.2 harris41 47:
1.1 harris41 48: # Security
49: $ENV{'PATH'}=""; # Nullify path information.
50: $ENV{'BASH_ENV'}=""; # Nullify shell environment information.
1.2 harris41 51:
52: # Do not print error messages if there are command-line arguments
53: my $noprint=0;
54: if (@ARGV) {
55: $noprint=1;
56: }
57:
1.3 harris41 58: # Read in /etc/passwd, and make sure this process is running from user=www
1.2 harris41 59: open (IN, "</etc/passwd");
60: my @lines=<IN>;
61: close IN;
62: my $wwwid;
63: for my $l (@lines) {
64: chop $l;
65: my @F=split(/\:/,$l);
66: if ($F[0] eq 'www') {$wwwid=$F[2];}
67: }
68: if ($wwwid!=$<) {
69: print("User ID mismatch. This program must be run as user 'www'\n") unless $noprint;
70: exit 1;
71: }
72: &disable_root_capability;
73:
1.3 harris41 74: # Handle case of another lcpasswd process
75: unless (&try_to_lock("/tmp/lock_lcpasswd")) {
76: print "Error. Too many other simultaneous password change requests being made.\n" unless $noprint;
77: exit 4;
78: }
79:
80: # Gather input. Should only be 1 value (user name).
1.2 harris41 81: my @input;
1.3 harris41 82: if (@ARGV==1) {
1.2 harris41 83: @input=@ARGV;
84: }
85: elsif (@ARGV) {
1.3 harris41 86: print("Error. This program needs just 1 command-line argument (username).\n") unless $noprint;
1.9 harris41 87: unlink('/tmp/lock_lcpasswd');
1.2 harris41 88: exit 2;
89: }
90: else {
91: @input=<>;
1.3 harris41 92: if (@input!=1) {
93: print("Error. Only one line should be entered into standard input.\n") unless $noprint;
1.9 harris41 94: unlink('/tmp/lock_lcpasswd');
1.2 harris41 95: exit 3;
96: }
97: map {chop} @input;
98: }
1.4 harris41 99:
100: my ($username)=@input;
101: $username=~/^(\w+)$/;
102: my $safeusername=$1;
1.10 harris41 103: if ($username ne $safeusername) {
104: print "Error. The user name specified has invalid characters.\n";
105: unlink('/tmp/lock_lcpasswd');
1.11 harris41 106: exit 5;
1.10 harris41 107: }
1.4 harris41 108:
1.5 harris41 109: &enable_root_capability;
110:
1.4 harris41 111: # By using the system userdel command:
112: # Remove entry from /etc/passwd if it exists
113: # Remove entry from /etc/groups if it exists
1.8 harris41 114: # I surround with groupdel command to make absolutely sure the group definition disappears.
1.12 harris41 115: system('/usr/sbin/groupdel',$safeusername); # ignore error message
116: system('/usr/sbin/userdel',$safeusername); # ignore error message
117: system('/usr/sbin/groupdel',$safeusername); # ignore error message
1.4 harris41 118:
119: # Remove entry from /etc/smbpasswd if it exists
1.13 foxr 120: # the safest way to do this is with smbpasswd -x
121: # as that's independent of location of the smbpasswd file.
122: #
123: if (-e '/usr/bin/smbpasswd') {
124: ($>,$<) = (0,0); # fool smbpasswd to think this is not setuid.
125: system('/usr/bin/smbpasswd -x '.$safeusername);
1.14 foxr 126: $< = $wwwid;
1.13 foxr 127: }
1.4 harris41 128:
129:
130: # Change ownership on directory from username:username to www:www
131: # This prevents subsequently added users from having access.
132:
1.5 harris41 133: system('/bin/chown','-R','www:www',"/home/$safeusername");
1.3 harris41 134:
135: &disable_root_capability;
136: unlink("/tmp/lock_lcpasswd");
137: exit 0;
138:
139: # ----------------------------------------------------------- have setuid script run as root
140: sub enable_root_capability {
141: if ($wwwid==$>) {
142: ($<,$>)=($>,$<);
143: ($(,$))=($),$();
144: }
145: else {
146: # root capability is already enabled
147: }
148: return $>;
149: }
150:
151: # ----------------------------------------------------------- have setuid script run as www
152: sub disable_root_capability {
153: if ($wwwid==$<) {
154: ($<,$>)=($>,$<);
155: ($(,$))=($),$();
156: }
157: else {
158: # root capability is already disabled
159: }
1.2 harris41 160: }
161:
1.3 harris41 162: # ----------------------------------- make sure that another lcpasswd process isn't running
163: sub try_to_lock {
164: my ($lockfile)=@_;
165: my $currentpid;
166: my $lastpid;
167: # Do not manipulate lock file as root
168: if ($>==0) {
169: return 0;
170: }
171: # Try to generate lock file.
172: # Wait 3 seconds. If same process id is in
173: # lock file, then assume lock file is stale, and
174: # go ahead. If process id's fluctuate, try
175: # for a maximum of 10 times.
176: for (0..10) {
177: if (-e $lockfile) {
178: open(LOCK,"<$lockfile");
179: $currentpid=<LOCK>;
180: close LOCK;
181: if ($currentpid==$lastpid) {
182: last;
183: }
184: sleep 3;
185: $lastpid=$currentpid;
186: }
187: else {
188: last;
189: }
190: if ($_==10) {
191: return 0;
192: }
193: }
194: open(LOCK,">$lockfile");
195: print LOCK $$;
196: close LOCK;
197: return 1;
198: }
1.2 harris41 199:
1.1 harris41 200:
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>
![[BACK]](/icons/back.gif){kind=icon}
Return to lcuserdel CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [LON-CAPA] / loncom