--- loncom/lond	2004/08/28 15:52:51	1.244
+++ loncom/lond	2004/09/08 18:57:33	1.252
@@ -2,7 +2,7 @@
 # The LearningOnline Network
 # lond "LON Daemon" Server (port "LOND" 5663)
 #
-# $Id: lond,v 1.244 2004/08/28 15:52:51 banghart Exp $
+# $Id: lond,v 1.252 2004/09/08 18:57:33 albertel Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -57,7 +57,7 @@ my $DEBUG = 0;		       # Non zero to ena
 my $status='';
 my $lastlog='';
 
-my $VERSION='$Revision: 1.244 $'; #' stupid emacs
+my $VERSION='$Revision: 1.252 $'; #' stupid emacs
 my $remoteVERSION;
 my $currenthostid="default";
 my $currentdomainid;
@@ -331,8 +331,43 @@ sub InsecureConnection {
     
 
 }
-
 #
+#   Safely execute a command (as long as it's not a shel command and doesn
+#   not require/rely on shell escapes.   The function operates by doing a
+#   a pipe based fork and capturing stdout and stderr  from the pipe.
+#
+# Formal Parameters:
+#     $line                    - A line of text to be executed as a command.
+# Returns:
+#     The output from that command.  If the output is multiline the caller
+#     must know how to split up the output.
+#
+#
+sub execute_command {
+    my ($line)    = @_;
+    my @words     = split(/\s/, $line);	# Bust the command up into words.
+    my $output    = "";
+
+    my $pid = open(CHILD, "-|");
+    
+    if($pid) {			# Parent process
+	Debug("In parent process for execute_command");
+	my @data = <CHILD>;	# Read the child's outupt...
+	close CHILD;
+	foreach my $output_line (@data) {
+	    Debug("Adding $output_line");
+	    $output .= $output_line; # Presumably has a \n on it.
+	}
+
+    } else {			# Child process
+	close (STDERR);
+	open  (STDERR, ">&STDOUT");# Combine stderr, and stdout...
+	exec(@words);		# won't return.
+    }
+    return $output;
+}
+
+
 #   GetCertificate: Given a transaction that requires a certificate,
 #   this function will extract the certificate from the transaction
 #   request.  Note that at this point, the only concept of a certificate
@@ -1013,7 +1048,7 @@ sub tie_user_hash {
 	   $how, 0640)) {
 	# If this is a namespace for which a history is kept,
 	# make the history log entry:    
-	if (($namespace =~/^nohist\_/) && (defined($loghead))) {
+	if (($namespace !~/^nohist\_/) && (defined($loghead))) {
 	    my $args = scalar @_;
 	    Debug(" Opening history: $namespace $args");
 	    my $hfh = IO::File->new(">>$proname/$namespace.hist"); 
@@ -1302,12 +1337,33 @@ sub push_file_handler {
 
 sub du_handler {
     my ($cmd, $ududir, $client) = @_;
+    my ($ududir) = split(/:/,$ududir); # Make 'telnet' testing easier.
     my $userinput = "$cmd:$ududir";
-    my $duout='';
-    my $du_cmd;
-    $du_cmd = 'du -ks '.$ududir.' 2>/dev/null)';
-    $duout = qx[$du_cmd];
-    print $client "$du_cmd -- $ududir -- $duout\n";
+
+    if ($ududir=~/\.\./ || $ududir!~m|^/home/httpd/|) {
+	&Failure($client,"refused\n","$cmd:$ududir");
+	return 1;
+    }
+    #  Since $ududir could have some nasties in it,
+    #  we will require that ududir is a valid
+    #  directory.  Just in case someone tries to
+    #  slip us a  line like .;(cd /home/httpd rm -rf*)
+    #  etc.
+    #
+    if (-d $ududir) {
+	#  And as Shakespeare would say to make
+	#  assurance double sure, 
+	# use execute_command to ensure that the command is not executed in
+	# a shell that can screw us up.
+
+	my $duout = execute_command("du -ks $ududir");
+	$duout=~s/[^\d]//g; #preserve only the numbers
+	&Reply($client,"$duout\n","$cmd:$ududir");
+    } else {
+
+	&Failure($client, "bad_directory:$ududir\n","$cmd:$ududir"); 
+
+    }
     return 1;
 }
 &register_handler("du", \&du_handler, 0, 1, 0);
@@ -1369,7 +1425,7 @@ sub ls_handler {
 	$ulsout='no_such_dir';
     }
     if ($ulsout eq '') { $ulsout='empty'; }
-    print $client "$ulsout\n";
+    &Reply($client, "$ulsout\n", $userinput); # This supports debug logging.
     
     return 1;
 
@@ -1711,7 +1767,7 @@ sub change_authentication_handler {
 	    my $result=&make_passwd_file($uname, $umode,$npass,$passfilename);
 	    &Reply($client, $result, $userinput);
 	} else {	       
-	    &Failure($client, "non_authorized", $userinput); # Fail the user now.
+	    &Failure($client, "non_authorized\n", $userinput); # Fail the user now.
 	}
     }
     return 1;
@@ -2062,14 +2118,14 @@ sub token_auth_user_file_handler {
     my ($fname, $session) = split(/:/, $tail);
     
     chomp($session);
-    my $reply='non_auth';
+    my $reply="non_auth\n";
     if (open(ENVIN,$perlvar{'lonIDsDir'}.'/'.
 	     $session.'.id')) {
 	while (my $line=<ENVIN>) {
-	    if ($line=~ m|userfile\.\Q$fname\E\=|) { $reply='ok'; }
+	    if ($line=~ m|userfile\.\Q$fname\E\=|) { $reply="ok\n"; }
 	}
 	close(ENVIN);
-	&Reply($client, $reply);
+	&Reply($client, $reply, "$cmd:$tail");
     } else {
 	&Failure($client, "invalid_token\n", "$cmd:$tail");
     }
@@ -3368,6 +3424,374 @@ sub tmp_del_handler {
 }
 &register_handler("tmpdel", \&tmp_del_handler, 0, 1, 0);
 #
+#   Processes the setannounce command.  This command
+#   creates a file named announce.txt in the top directory of
+#   the documentn root and sets its contents.  The announce.txt file is
+#   printed in its entirety at the LonCAPA login page.  Note:
+#   once the announcement.txt fileis created it cannot be deleted.
+#   However, setting the contents of the file to empty removes the
+#   announcement from the login page of loncapa so who cares.
+#
+# Parameters:
+#    $cmd          - The command that got us dispatched.
+#    $announcement - The text of the announcement.
+#    $client       - Socket open on the client process.
+# Retunrns:
+#   1             - Indicating request processing should continue
+# Side Effects:
+#   The file {DocRoot}/announcement.txt is created.
+#   A reply is sent to $client.
+#
+sub set_announce_handler {
+    my ($cmd, $announcement, $client) = @_;
+  
+    my $userinput    = "$cmd:$announcement";
+
+    chomp($announcement);
+    $announcement=&unescape($announcement);
+    if (my $store=IO::File->new('>'.$perlvar{'lonDocRoot'}.
+				'/announcement.txt')) {
+	print $store $announcement;
+	close $store;
+	&Reply($client, "ok\n", $userinput);
+    } else {
+	&Failure($client, "error: ".($!+0)."\n", $userinput);
+    }
+
+    return 1;
+}
+&register_handler("setannounce", \&set_announce_handler, 0, 1, 0);
+#
+#  Return the version of the daemon.  This can be used to determine
+#  the compatibility of cross version installations or, alternatively to
+#  simply know who's out of date and who isn't.  Note that the version
+#  is returned concatenated with the tail.
+# Parameters:
+#   $cmd        - the request that dispatched to us.
+#   $tail       - Tail of the request (client's version?).
+#   $client     - Socket open on the client.
+#Returns:
+#   1 - continue processing requests.
+# Side Effects:
+#   Replies with version to $client.
+sub get_version_handler {
+    my ($cmd, $tail, $client) = @_;
+
+    my $userinput  = $cmd.$tail;
+    
+    &Reply($client, &version($userinput)."\n", $userinput);
+
+
+    return 1;
+}
+&register_handler("version", \&get_version_handler, 0, 1, 0);
+#  Set the current host and domain.  This is used to support
+#  multihomed systems.  Each IP of the system, or even separate daemons
+#  on the same IP can be treated as handling a separate lonCAPA virtual
+#  machine.  This command selects the virtual lonCAPA.  The client always
+#  knows the right one since it is lonc and it is selecting the domain/system
+#  from the hosts.tab file.
+# Parameters:
+#    $cmd      - Command that dispatched us.
+#    $tail     - Tail of the command (domain/host requested).
+#    $socket   - Socket open on the client.
+#
+# Returns:
+#     1   - Indicates the program should continue to process requests.
+# Side-effects:
+#     The default domain/system context is modified for this daemon.
+#     a reply is sent to the client.
+#
+sub set_virtual_host_handler {
+    my ($cmd, $tail, $socket) = @_;
+  
+    my $userinput  ="$cmd:$tail";
+
+    &Reply($client, &sethost($userinput)."\n", $userinput);
+
+
+    return 1;
+}
+&register_handler("sethost", \&set_virtual_host_handler, 0, 1, 0);
+
+#  Process a request to exit:
+#   - "bye" is sent to the client.
+#   - The client socket is shutdown and closed.
+#   - We indicate to the caller that we should exit.
+# Formal Parameters:
+#   $cmd                - The command that got us here.
+#   $tail               - Tail of the command (empty).
+#   $client             - Socket open on the tail.
+# Returns:
+#   0      - Indicating the program should exit!!
+#
+sub exit_handler {
+    my ($cmd, $tail, $client) = @_;
+
+    my $userinput = "$cmd:$tail";
+
+    &logthis("Client $clientip ($clientname) hanging up: $userinput");
+    &Reply($client, "bye\n", $userinput);
+    $client->shutdown(2);        # shutdown the socket forcibly.
+    $client->close();
+
+    return 0;
+}
+&register_handler("exit", \&exit_handler, 0,1,1);
+&register_handler("init", \&exit_handler, 0,1,1);
+&register_handler("quit", \&exit_handler, 0,1,1);
+
+#  Determine if auto-enrollment is enabled.
+#  Note that the original had what I believe to be a defect.
+#  The original returned 0 if the requestor was not a registerd client.
+#  It should return "refused".
+# Formal Parameters:
+#   $cmd       - The command that invoked us.
+#   $tail      - The tail of the command (Extra command parameters.
+#   $client    - The socket open on the client that issued the request.
+# Returns:
+#    1         - Indicating processing should continue.
+#
+sub enrollment_enabled_handler {
+    my ($cmd, $tail, $client) = @_;
+    my $userinput = $cmd.":".$tail; # For logging purposes.
+
+    
+    my $cdom = split(/:/, $tail);   # Domain we're asking about.
+    my $outcome  = &localenroll::run($cdom);
+    &Reply($client, "$outcome\n", $userinput);
+
+    return 1;
+}
+&register_handler("autorun", \&enrollment_enabled_handler, 0, 1, 0);
+
+#   Get the official sections for which auto-enrollment is possible.
+#   Since the admin people won't know about 'unofficial sections' 
+#   we cannot auto-enroll on them.
+# Formal Parameters:
+#    $cmd     - The command request that got us dispatched here.
+#    $tail    - The remainder of the request.  In our case this
+#               will be split into:
+#               $coursecode   - The course name from the admin point of view.
+#               $cdom         - The course's domain(?).
+#    $client  - Socket open on the client.
+# Returns:
+#    1    - Indiciting processing should continue.
+#
+sub get_sections_handler {
+    my ($cmd, $tail, $client) = @_;
+    my $userinput = "$cmd:$tail";
+
+    my ($coursecode, $cdom) = split(/:/, $tail);
+    my @secs = &localenroll::get_sections($coursecode,$cdom);
+    my $seclist = &escape(join(':',@secs));
+
+    &Reply($client, "$seclist\n", $userinput);
+    
+
+    return 1;
+}
+&register_handler("autogetsections", \&get_sections_handler, 0, 1, 0);
+
+#   Validate the owner of a new course section.  
+#
+# Formal Parameters:
+#   $cmd      - Command that got us dispatched.
+#   $tail     - the remainder of the command.  For us this consists of a
+#               colon separated string containing:
+#                  $inst    - Course Id from the institutions point of view.
+#                  $owner   - Proposed owner of the course.
+#                  $cdom    - Domain of the course (from the institutions
+#                             point of view?)..
+#   $client   - Socket open on the client.
+#
+# Returns:
+#   1        - Processing should continue.
+#
+sub validate_course_owner_handler {
+    my ($cmd, $tail, $client)  = @_;
+    my $userinput = "$cmd:$tail";
+    my ($inst_course_id, $owner, $cdom) = split(/:/, $tail);
+
+    my $outcome = &localenroll::new_course($inst_course_id,$owner,$cdom);
+    &Reply($client, "$outcome\n", $userinput);
+
+
+
+    return 1;
+}
+&register_handler("autonewcourse", \&validate_course_owner_handler, 0, 1, 0);
+#
+#   Validate a course section in the official schedule of classes
+#   from the institutions point of view (part of autoenrollment).
+#
+# Formal Parameters:
+#   $cmd          - The command request that got us dispatched.
+#   $tail         - The tail of the command.  In this case,
+#                   this is a colon separated set of words that will be split
+#                   into:
+#                        $inst_course_id - The course/section id from the
+#                                          institutions point of view.
+#                        $cdom           - The domain from the institutions
+#                                          point of view.
+#   $client       - Socket open on the client.
+# Returns:
+#    1           - Indicating processing should continue.
+#
+sub validate_course_section_handler {
+    my ($cmd, $tail, $client) = @_;
+    my $userinput = "$cmd:$tail";
+    my ($inst_course_id, $cdom) = split(/:/, $tail);
+
+    my $outcome=&localenroll::validate_courseID($inst_course_id,$cdom);
+    &Reply($client, "$outcome\n", $userinput);
+
+
+    return 1;
+}
+&register_handler("autovalidatecourse", \&validate_course_section_handler, 0, 1, 0);
+
+#
+#   Create a password for a new auto-enrollment user.
+#   I think/guess, this password allows access to the institutions 
+#   AIS class list server/services.  Stuart can correct this comment
+#   when he finds out how wrong I am.
+#
+# Formal Parameters:
+#    $cmd     - The command request that got us dispatched.
+#    $tail    - The tail of the command.   In this case this is a colon separated
+#               set of words that will be split into:
+#               $authparam - An authentication parameter (username??).
+#               $cdom      - The domain of the course from the institution's
+#                            point of view.
+#    $client  - The socket open on the client.
+# Returns:
+#    1 - continue processing.
+#
+sub create_auto_enroll_password_handler {
+    my ($cmd, $tail, $client) = @_;
+    my $userinput = "$cmd:$tail";
+
+    my ($authparam, $cdom) = split(/:/, $userinput);
+
+    my ($create_passwd,$authchk);
+    ($authparam,
+     $create_passwd,
+     $authchk) = &localenroll::create_password($authparam,$cdom);
+
+    &Reply($client, &escape($authparam.':'.$create_passwd.':'.$authchk)."\n",
+	   $userinput);
+
+
+    return 1;
+}
+&register_handler("autocreatepassword", \&create_auto_enroll_password_handler, 
+		  0, 1, 0);
+
+#   Retrieve and remove temporary files created by/during autoenrollment.
+#
+# Formal Parameters:
+#    $cmd      - The command that got us dispatched.
+#    $tail     - The tail of the command.  In our case this is a colon 
+#                separated list that will be split into:
+#                $filename - The name of the file to remove.
+#                            The filename is given as a path relative to
+#                            the LonCAPA temp file directory.
+#    $client   - Socket open on the client.
+#
+# Returns:
+#   1     - Continue processing.
+
+sub retrieve_auto_file_handler {
+    my ($cmd, $tail, $client)    = @_;
+    my $userinput                = "cmd:$tail";
+
+    my ($filename)   = split(/:/, $tail);
+
+    my $source = $perlvar{'lonDaemons'}.'/tmp/'.$filename;
+    if ( (-e $source) && ($filename ne '') ) {
+	my $reply = '';
+	if (open(my $fh,$source)) {
+	    while (<$fh>) {
+		chomp($_);
+		$_ =~ s/^\s+//g;
+		$_ =~ s/\s+$//g;
+		$reply .= $_;
+	    }
+	    close($fh);
+	    &Reply($client, &escape($reply)."\n", $userinput);
+
+#   Does this have to be uncommented??!?  (RF).
+#
+#                                unlink($source);
+	} else {
+	    &Failure($client, "error\n", $userinput);
+	}
+    } else {
+	&Failure($client, "error\n", $userinput);
+    }
+    
+
+    return 1;
+}
+&register_handler("autoretrieve", \&retrieve_auto_file_handler, 0,1,0);
+
+#
+#   Read and retrieve institutional code format (for support form).
+# Formal Parameters:
+#    $cmd        - Command that dispatched us.
+#    $tail       - Tail of the command.  In this case it conatins 
+#                  the course domain and the coursename.
+#    $client     - Socket open on the client.
+# Returns:
+#    1     - Continue processing.
+#
+sub get_institutional_code_format_handler {
+    my ($cmd, $tail, $client)   = @_;
+    my $userinput               = "$cmd:$tail";
+
+    my $reply;
+    my($cdom,$course) = split(/:/,$tail);
+    my @pairs = split/\&/,$course;
+    my %instcodes = ();
+    my %codes = ();
+    my @codetitles = ();
+    my %cat_titles = ();
+    my %cat_order = ();
+    foreach (@pairs) {
+	my ($key,$value) = split/=/,$_;
+	$instcodes{&unescape($key)} = &unescape($value);
+    }
+    my $formatreply = &localenroll::instcode_format($cdom,
+						    \%instcodes,
+						    \%codes,
+						    \@codetitles,
+						    \%cat_titles,
+						    \%cat_order);
+    if ($formatreply eq 'ok') {
+	my $codes_str = &hash2str(%codes);
+	my $codetitles_str = &array2str(@codetitles);
+	my $cat_titles_str = &hash2str(%cat_titles);
+	my $cat_order_str = &hash2str(%cat_order);
+	&Reply($client,
+	       $codes_str.':'.$codetitles_str.':'.$cat_titles_str.':'
+	       .$cat_order_str."\n",
+	       $userinput);
+    } else {
+	# this else branch added by RF since if not ok, lonc will
+	# hang waiting on reply until timeout.
+	#
+	&Reply($client, "format_error\n", $userinput);
+    }
+    
+    return 1;
+}
+
+&register_handler("autoinstcodeformat", \&get_institutional_code_format_handler,
+		  0,1,0);
+
+#
+#
 #
 #
 #
@@ -3412,7 +3836,7 @@ sub process_request {
 	$userinput = decipher($userinput);
 	$wasenc=1;
 	if(!$userinput) {	# Cipher not defined.
-	    &Failure($client, "error: Encrypted data without negotated key");
+	    &Failure($client, "error: Encrypted data without negotated key\n");
 	    return 0;
 	}
     }
@@ -3484,52 +3908,8 @@ sub process_request {
 
 #------------------- Commands not yet in spearate handlers. --------------
 
-
-
-# ----------------------------------------------------------------- setannounce
-    if ($userinput =~ /^setannounce/) {
-	if (isClient) {
-	    my ($cmd,$announcement)=split(/:/,$userinput);
-	    chomp($announcement);
-	    $announcement=&unescape($announcement);
-	    if (my $store=IO::File->new('>'.$perlvar{'lonDocRoot'}.
-					'/announcement.txt')) {
-		print $store $announcement;
-		close $store;
-		print $client "ok\n";
-	    } else {
-		print $client "error: ".($!+0)."\n";
-	    }
-	} else {
-	    Reply($client, "refused\n", $userinput);
-	    
-	}
-# ------------------------------------------------------------------ Hanging up
-    } elsif (($userinput =~ /^exit/) ||
-	     ($userinput =~ /^init/)) { # no restrictions.
-	&logthis(
-		 "Client $clientip ($clientname) hanging up: $userinput");
-	print $client "bye\n";
-	$client->shutdown(2);        # shutdown the socket forcibly.
-	$client->close();
-	return 0;
-	
-# ---------------------------------- set current host/domain
-    } elsif ($userinput =~ /^sethost/) {
-	if (isClient) {
-	    print $client &sethost($userinput)."\n";
-	} else {
-	    print $client "refused\n";
-	}
-#---------------------------------- request file (?) version.
-    } elsif ($userinput =~/^version/) {
-	if (isClient) {
-	    print $client &version($userinput)."\n";
-	} else {
-	    print $client "refused\n";
-	}
 #------------------------------- is auto-enrollment enabled?
-    } elsif ($userinput =~/^autorun/) {
+    if ($userinput =~/^autorun/) {
 	if (isClient) {
 	    my ($cmd,$cdom) = split(/:/,$userinput);
 	    my $outcome = &localenroll::run($cdom);
@@ -3601,7 +3981,8 @@ sub process_request {
 	} else {
 	    print $client "refused\n";
 	}
-#---------------------  read and retrieve institutional code format (for support form).
+#---------------------  read and retrieve institutional code format 
+#                          (for support form).
     } elsif ($userinput =~/^autoinstcodeformat/) {
 	if (isClient) {
 	    my $reply;
@@ -4663,7 +5044,8 @@ sub validate_user {
     # At the end of this function. I'll ensure that it's not still that
     # value so we don't just wind up returning some accidental value
     # as a result of executing an unforseen code path that
-    # did not set $validated.
+    # did not set $validated.  At the end of valid execution paths,
+    # validated shoule be 1 for success or 0 for failuer.
 
     my $validated = -3.14159;
 
@@ -4751,7 +5133,11 @@ sub validate_user {
     #
 
     unless ($validated != -3.14159) {
-	die "ValidateUser - failed to set the value of validated";
+	#  I >really really< want to know if this happens.
+	#  since it indicates that user authentication is badly
+	#  broken in some code path.
+        #
+	die "ValidateUser - failed to set the value of validated $domain, $user $password";
     }
     return $validated;
 }