--- loncom/lond	2018/10/29 02:57:30	1.550
+++ loncom/lond	2020/03/30 11:04:03	1.561
@@ -2,7 +2,7 @@
 # The LearningOnline Network
 # lond "LON Daemon" Server (port "LOND" 5663)
 #
-# $Id: lond,v 1.550 2018/10/29 02:57:30 raeburn Exp $
+# $Id: lond,v 1.561 2020/03/30 11:04:03 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -65,7 +65,7 @@ my $DEBUG = 0;		       # Non zero to ena
 my $status='';
 my $lastlog='';
 
-my $VERSION='$Revision: 1.550 $'; #' stupid emacs
+my $VERSION='$Revision: 1.561 $'; #' stupid emacs
 my $remoteVERSION;
 my $currenthostid="default";
 my $currentdomainid;
@@ -80,11 +80,12 @@ my $clientsamedom;              # LonCAP
                                 # and client.
 my $clientsameinst;             # LonCAPA "internet domain" same for 
                                 # this host and client.
-my $clientremoteok;             # Client allowed to host domain's users.
-                                # (version constraints ignored), not set
-                                # if this host and client share "internet domain". 
-my %clientprohibited;           # Actions prohibited on client;
- 
+my $clientremoteok;             # Current domain permits hosting on client
+                                # (not set if host and client share "internet domain").
+                                # Values are 0 or 1; 1 if allowed.
+my %clientprohibited;           # Commands from client prohibited for domain's
+                                # users.
+
 my $server;
 
 my $keymode;
@@ -176,6 +177,7 @@ my @installerrors = ("ok",
 # shared    ("Access to other domain's content by this domain")
 # enroll    ("Enrollment in this domain's courses by others")
 # coaurem   ("Co-author roles for this domain's users elsewhere")
+# othcoau   ("Co-author roles in this domain for others")
 # domroles  ("Domain roles in this domain assignable to others")
 # catalog   ("Course Catalog for this domain displayed elsewhere")
 # reqcrs    ("Requests for creation of courses in this domain by others")
@@ -218,12 +220,15 @@ my %trust = (
                courseidput => {remote => 1, domroles => 1, enroll => 1},
                courseidputhash => {remote => 1, domroles => 1, enroll => 1},
                courselastaccess => {remote => 1, domroles => 1, enroll => 1},
+               coursesessions => {institutiononly => 1},
                currentauth => {remote => 1, domroles => 1, enroll => 1},
                currentdump => {remote => 1, enroll => 1},
                currentversion => {remote=> 1, content => 1},
                dcmaildump => {remote => 1, domroles => 1},
                dcmailput => {remote => 1, domroles => 1},
                del => {remote => 1, domroles => 1, enroll => 1, content => 1},
+               delbalcookie => {institutiononly => 1},
+               delusersession => {institutiononly => 1},
                deldom => {remote => 1, domroles => 1}, # not currently used
                devalidatecache => {institutiononly => 1},
                domroleput => {remote => 1, enroll => 1},
@@ -234,7 +239,7 @@ my %trust = (
                edit => {institutiononly => 1},  #not used currently
                eget => {remote => 1, domroles => 1, enroll => 1}, #not used currently
                egetdom => {remote => 1, domroles => 1, enroll => 1, },
-               ekey => {}, #not used currently
+               ekey => {anywhere => 1},
                exit => {anywhere => 1},
                fetchuserfile => {remote => 1, enroll => 1},
                get => {remote => 1, domroles => 1, enroll => 1},
@@ -299,9 +304,9 @@ my %trust = (
                store => {remote => 1, enroll => 1, reqcrs => 1,},
                studentphoto => {remote => 1, enroll => 1},
                sub => {content => 1,},
-               tmpdel => {anywhere => 1},
-               tmpget => {anywhere => 1},
-               tmpput => {anywhere => 1},
+               tmpdel => {institutiononly => 1},
+               tmpget => {institutiononly => 1},
+               tmpput => {remote => 1, othcoau => 1},
                tokenauthuserfile => {anywhere => 1},
                unsub => {content => 1,},
                update => {shared => 1},
@@ -831,8 +836,8 @@ sub PushFile {
     #   hosts.tab  ($filename eq host).
     #   domain.tab ($filename eq domain).
     #   dns_hosts.tab ($filename eq dns_host).
-    #   dns_domain.tab ($filename eq dns_domain). 
-    #   loncapaCAcrl.pem ($filename eq loncapaCAcrl);   
+    #   dns_domain.tab ($filename eq dns_domain).
+    #   loncapaCAcrl.pem ($filename eq loncapaCAcrl).
     # Construct the destination filename or reject the request.
     #
     # lonManage is supposed to ensure this, however this session could be
@@ -2027,7 +2032,7 @@ sub read_lonnet_global {
                 }
                 if ($what eq 'perlvar') {
                     if (!exists($packagevars{$what}{'lonBalancer'})) {
-                        if ($dist =~ /^(centos|rhes|fedora|scientific)/) {
+                        if ($dist =~ /^(centos|rhes|fedora|scientific|oracle)/) {
                             my $othervarref=LONCAPA::Configuration::read_conf('httpd.conf');
                             if (ref($othervarref) eq 'HASH') {
                                 $items->{'lonBalancer'} = $othervarref->{'lonBalancer'};
@@ -2345,12 +2350,84 @@ sub change_password_handler {
     }
     if($validated) {
 	my $realpasswd  = &get_auth_type($udom, $uname); # Defined since authd.
-	
 	my ($howpwd,$contentpwd)=split(/:/,$realpasswd);
+        my $notunique;
 	if ($howpwd eq 'internal') {
 	    &Debug("internal auth");
             my $ncpass = &hash_passwd($udom,$npass);
-	    if(&rewrite_password_file($udom, $uname, "internal:$ncpass")) {
+            my (undef,$method,@rest) = split(/!/,$contentpwd);
+            if ($method eq 'bcrypt') {
+                my %passwdconf = &Apache::lonnet::get_passwdconf($udom);
+                if (($passwdconf{'numsaved'}) && ($passwdconf{'numsaved'} =~ /^\d+$/)) {
+                    my @oldpasswds;
+                    my $userpath = &propath($udom,$uname);
+                    my $fullpath = $userpath.'/oldpasswds';
+                    if (-d $userpath) {
+                        my @oldfiles;
+                        if (-e $fullpath) {
+                            if (opendir(my $dir,$fullpath)) {
+                                (@oldfiles) = grep(/^\d+$/,readdir($dir));
+                                closedir($dir);
+                            }
+                            if (@oldfiles) {
+                                @oldfiles = sort { $b <=> $a } (@oldfiles);
+                                my $numremoved = 0;
+                                for (my $i=0; $i<@oldfiles; $i++) {
+                                    if ($i>=$passwdconf{'numsaved'}) {
+                                        if (-f "$fullpath/$oldfiles[$i]") {
+                                            if (unlink("$fullpath/$oldfiles[$i]")) {
+                                                $numremoved ++;
+                                            }
+                                        }
+                                    } elsif (open(my $fh,'<',"$fullpath/$oldfiles[$i]")) {
+                                        while (my $line = <$fh>) {
+                                            push(@oldpasswds,$line);
+                                        }
+                                        close($fh);
+                                    }
+                                }
+                                if ($numremoved) {
+                                    &logthis("unlinked $numremoved old password files for $uname:$udom");
+                                }
+                            }
+                        }
+                        push(@oldpasswds,$contentpwd);
+                        foreach my $item (@oldpasswds) {
+                            my (undef,$method,@rest) = split(/!/,$item);
+                            if ($method eq 'bcrypt') {
+                                my $result = &hash_passwd($udom,$npass,@rest);
+                                if ($result eq $item) {
+                                    $notunique = 1;
+                                    last;
+                                }
+                            }
+                        }
+                        unless ($notunique) {
+                            unless (-e $fullpath) {
+                                if (&mkpath("$fullpath/")) {
+                                    chmod(0700,$fullpath);
+                                }
+                            }
+                            if (-d $fullpath) {
+                                my $now = time;
+                                if (open(my $fh,'>',"$fullpath/$now")) {
+                                    print $fh $contentpwd;
+                                    close($fh);
+                                    chmod(0400,"$fullpath/$now");
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+            if ($notunique) {
+                my $msg="Result of password change for $uname:$udom - password matches one used before";
+                if ($lonhost) {
+                    $msg .= " - request originated from: $lonhost";
+                }
+                &logthis($msg);
+                &Reply($client, "prioruse\n", $userinput);
+	    } elsif (&rewrite_password_file($udom, $uname, "internal:$ncpass")) {
 		my $msg="Result of password change for $uname: pwchange_success";
                 if ($lonhost) {
                     $msg .= " - request originated from: $lonhost";
@@ -2367,7 +2444,7 @@ sub change_password_handler {
 	    my $result = &change_unix_password($uname, $npass);
             if ($result eq 'ok') {
                 &update_passwd_history($uname,$udom,$howpwd,$context);
-             }
+            }
 	    &logthis("Result of password change for $uname: ".
 		     $result);
 	    &Reply($client, \$result, $userinput);
@@ -2378,7 +2455,6 @@ sub change_password_handler {
 	    #
 	    &Failure( $client, "auth_mode_error\n", $userinput);
 	}  
-	
     } else {
 	if ($failure eq '') {
 	    $failure = 'non_authorized';
@@ -2959,6 +3035,54 @@ sub user_has_session_handler {
 }
 &register_handler("userhassession", \&user_has_session_handler, 0,1,0);
 
+sub del_usersession_handler {
+    my ($cmd, $tail, $client) = @_;
+
+    my $result;
+    my ($udom, $uname) = map { &unescape($_) } (split(/:/, $tail));
+    if (($udom =~ /^$LONCAPA::match_domain$/) && ($uname =~ /^$LONCAPA::match_username$/)) {
+        my $lonidsdir = $perlvar{'lonIDsDir'};
+        if (-d $lonidsdir) {
+            if (opendir(DIR,$lonidsdir)) {
+                my $filename;
+                while ($filename=readdir(DIR)) {
+                    if ($filename=~/^\Q$uname\E_\d+_\Q$udom\E_/) {
+                        if (tie(my %oldenv,'GDBM_File',"$lonidsdir/$filename",
+                                &GDBM_READER(),0640)) {
+                            my $linkedfile;
+                            if (exists($oldenv{'user.linkedenv'})) {
+                                $linkedfile = $oldenv{'user.linkedenv'};
+                            }
+                            untie(%oldenv);
+                            $result = unlink("$lonidsdir/$filename");
+                            if ($result) {
+                                if ($linkedfile =~ /^[a-f0-9]+_linked$/) {
+                                    if (-l "$lonidsdir/$linkedfile.id") {
+                                        unlink("$lonidsdir/$linkedfile.id");
+                                    }
+                                }
+                            }
+                        } else {
+                            $result = unlink("$lonidsdir/$filename");
+                        }
+                        last;
+                    }
+                }
+            }
+        }
+        if ($result == 1) {
+            &Reply($client, "$result\n", "$cmd:$tail");
+        } else {
+            &Reply($client, "not_found\n", "$cmd:$tail");
+        }
+    } else {
+        &Failure($client, "invalid_user\n", "$cmd:$tail");
+    }
+    return 1;
+}
+
+&register_handler("delusersession", \&del_usersession_handler, 0,1,0);
+
 #
 #  Authenticate access to a user file by checking that the token the user's 
 #  passed also exists in their session file
@@ -4750,6 +4874,45 @@ sub course_lastaccess_handler {
 }
 &register_handler("courselastaccess",\&course_lastaccess_handler, 0, 1, 0);
 
+sub course_sessions_handler {
+    my ($cmd, $tail, $client) = @_;
+    my $userinput = "$cmd:$tail";
+    my ($cdom,$cnum,$lastactivity) = split(':',$tail);
+    my $dbsuffix = '_'.$cdom.'_'.$cnum.'.db';
+    my (%sessions,$qresult);
+    my $now=time;
+    if (opendir(DIR,$perlvar{'lonIDsDir'})) {
+        my $filename;
+        while ($filename=readdir(DIR)) {
+            next if ($filename=~/^\./);
+            next if ($filename=~/^publicuser_/);
+            next if ($filename=~/^[a-f0-9]+_(linked|lti_\d+)\.id$/);
+            if ($filename =~ /^($LONCAPA::match_user)_\d+_($LONCAPA::match_domain)_/) {
+                my ($uname,$udom) = ($1,$2);
+                next unless (-e "$perlvar{'lonDaemons'}/$uname$dbsuffix");
+                my $mtime = (stat("$perlvar{'lonIDsDir'}/$filename"))[9];
+                my $since=$now-$mtime;
+                if ($lastactivity < 0) {
+                    next if ($since <= $lastactivity);
+                } else {
+                    next if ($since > $lastactivity);
+                }
+                $sessions{$uname.':'.$udom} = $mtime;
+            }
+        }
+        closedir(DIR); 
+    }
+    foreach my $user (keys(%sessions)) {
+        $qresult.=&escape($user).'='.$sessions{$user}.'&';
+    }
+    if ($qresult) {
+        chop($qresult);
+    }
+    &Reply($client, \$qresult, $userinput);
+    return 1;
+}
+&register_handler("coursesessions",\&course_sessions_handler, 0, 1, 0);
+
 #
 # Puts an unencrypted entry in a namespace db file at the domain level 
 #
@@ -5521,6 +5684,58 @@ sub tmp_del_handler {
 &register_handler("tmpdel", \&tmp_del_handler, 0, 1, 0);
 
 #
+#  Process the delbalcookie command. This command deletes a balancer
+#  cookie in the lonBalancedir directory created by switchserver
+#
+# Parameters:
+#   $cmd      - Command that got us here.
+#   $cookie   - Cookie to be deleted.
+#   $client   - socket open on the client process.
+#
+# Returns:
+#   1     - Indicating processing should continue.
+# Side Effects:
+#   A cookie file is deleted from the lonBalancedir directory
+#   A reply is sent to the client.
+sub del_balcookie_handler {
+    my ($cmd, $cookie, $client) = @_;
+
+    my $userinput= "$cmd:$cookie";
+
+    chomp($cookie);
+    my $deleted = '';
+    if ($cookie =~ /^$LONCAPA::match_domain\_$LONCAPA::match_username\_[a-f0-9]{32}$/) {
+        my $execdir=$perlvar{'lonBalanceDir'};
+        if (-e "$execdir/$cookie.id") {
+            if (open(my $fh,'<',"$execdir/$cookie.id")) {
+                my $dodelete;
+                while (my $line = <$fh>) {
+                    chomp($line);
+                    if ($line eq $clientname) {
+                        $dodelete = 1;
+                        last;
+                    }
+                }
+                close($fh);
+                if ($dodelete) {
+                    if (unlink("$execdir/$cookie.id")) {
+                        $deleted = 1;
+                    }
+                }
+            }
+        }
+    }
+    if ($deleted) {
+        &Reply($client, "ok\n", $userinput);
+    } else {
+        &Failure( $client, "error: ".($!+0)."Unlinking cookie file Failed ".
+                  "while attempting delbalcookie\n", $userinput);
+    }
+    return 1;
+}
+&register_handler("delbalcookie", \&del_balcookie_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
@@ -7045,7 +7260,7 @@ sub UpdateHosts {
 
     my %oldconf = %secureconf;
     my %connchange;
-    if (lonssl::Read_Connect_Config(\%secureconf,\%crlchecked,\%perlvar) eq 'ok') {
+    if (lonssl::Read_Connect_Config(\%secureconf,\%perlvar,\%crlchecked) eq 'ok') {
         logthis('<font color="blue"> Reloaded SSL connection rules and cleared CRL checking history </font>');
     } else {
         logthis('<font color="yellow"> Failed to reload SSL connection rules and clear CRL checking history </font>');
@@ -7327,7 +7542,7 @@ if ($arch eq 'unknown') {
     chomp($arch);
 }
 
-unless (lonssl::Read_Connect_Config(\%secureconf,\%crlchecked,\%perlvar) eq 'ok') {
+unless (lonssl::Read_Connect_Config(\%secureconf,\%perlvar,\%crlchecked) eq 'ok') {
     &logthis('<font color="blue">No connectionrules table. Will fallback to loncapa.conf</font>');
 }
 
@@ -7416,7 +7631,7 @@ sub make_new_child {
         &Authen::Krb5::init_context();
 
         my $no_ets;
-        if ($dist =~ /^(?:centos|rhes|scientific)(\d+)$/) {
+        if ($dist =~ /^(?:centos|rhes|scientific|oracle)(\d+)$/) {
             if ($1 >= 7) {
                 $no_ets = 1;
             }
@@ -7461,7 +7676,7 @@ sub make_new_child {
 	    $ConnectionType = "manager";
 	    $clientname = $managers{$outsideip};
 	}
-	my ($clientok,$clientinfoset);
+	my $clientok;
 
 	if ($clientrec || $ismanager) {
 	    &status("Waiting for init from $clientip $clientname");
@@ -7562,7 +7777,6 @@ sub make_new_child {
 		    }
 	   
 		} else {
-                    $clientinfoset = &set_client_info();
 		    my $ok = InsecureConnection($client);
 		    if($ok) {
 			$clientok = 1;
@@ -7600,34 +7814,7 @@ sub make_new_child {
 # ------------------------------------------------------------ Process requests
 	    my $keep_going = 1;
 	    my $user_input;
-            unless ($clientinfoset) {
-                $clientinfoset = &set_client_info();
-            }
-            $clientremoteok = 0;
-            unless ($clientsameinst) {
-                $clientremoteok = 1;
-                my $defdom = &Apache::lonnet::host_domain($perlvar{'lonHostID'});
-                %clientprohibited = &get_prohibited($defdom);
-                if ($clientintdom) {
-                    my $remsessconf = &get_usersession_config($defdom,'remotesession');
-                    if (ref($remsessconf) eq 'HASH') {
-                        if (ref($remsessconf->{'remote'}) eq 'HASH') {
-                            if (ref($remsessconf->{'remote'}->{'excludedomain'}) eq 'ARRAY') {
-                                if (grep(/^\Q$clientintdom\E$/,@{$remsessconf->{'remote'}->{'excludedomain'}})) {
-                                    $clientremoteok = 0;
-                                }
-                            }
-                            if (ref($remsessconf->{'remote'}->{'includedomain'}) eq 'ARRAY') {
-                                if (grep(/^\Q$clientintdom\E$/,@{$remsessconf->{'remote'}->{'includedomain'}})) {
-                                    $clientremoteok = 1;
-                                } else {
-                                    $clientremoteok = 0;
-                                }
-                            }
-                        }
-                    }
-                }
-            }
+
 	    while(($user_input = get_request) && $keep_going) {
 		alarm(120);
 		Debug("Main: Got $user_input\n");
@@ -7660,22 +7847,30 @@ sub make_new_child {
 
 #
 #  Used to determine if a particular client is from the same domain
-#  as the current server, or from the same internet domain.
+#  as the current server, or from the same internet domain, and
+#  also if the client can host sessions for the domain's users.
+#  A hash is populated with keys set to commands sent by the client
+#  which may not be executed for this domain.
 #
 #  Optional input -- the client to check for domain and internet domain.
 #  If not specified, defaults to the package variable: $clientname
 #
 #  If called in array context will not set package variables, but will
 #  instead return an array of two values - (a) true if client is in the
-#  same domain as the server, and (b) true if client is in the same internet
-#  domain.
+#  same domain as the server, and (b) true if client is in the same 
+#  internet domain.
 #
 #  If called in scalar context, sets package variables for current client:
 #
-#  $clienthomedom  - LonCAPA domain of homeID for client.
-#  $clientsamedom  - LonCAPA domain same for this host and client.
-#  $clientintdom   - LonCAPA "internet domain" for client.
-#  $clientsameinst - LonCAPA "internet domain" same for this host & client.
+#  $clienthomedom    - LonCAPA domain of homeID for client.
+#  $clientsamedom    - LonCAPA domain same for this host and client.
+#  $clientintdom     - LonCAPA "internet domain" for client.
+#  $clientsameinst   - LonCAPA "internet domain" same for this host & client.
+#  $clientremoteok   - If current domain permits hosting on this client: 1
+#  %clientprohibited - Commands prohibited for domain's users for this client.
+#
+#  if the host and client have the same "internet domain", then the value
+#  of $clientremoteok is not used, and no commands are prohibited.
 #
 #  returns 1 to indicate package variables have been set for current client.
 #
@@ -7687,7 +7882,7 @@ sub set_client_info {
     my $clientserverhomeID = &Apache::lonnet::get_server_homeID($clienthost);
     my $homedom = &Apache::lonnet::host_domain($clientserverhomeID);
     my $samedom = 0;
-    if ($perlvar{'lonDefDom'} eq $homedom) {
+    if ($perlvar{'lonDefDomain'} eq $homedom) {
         $samedom = 1;
     }
     my $intdom = &Apache::lonnet::internet_dom($clientserverhomeID);
@@ -7707,6 +7902,13 @@ sub set_client_info {
         $clientsamedom = $samedom;
         $clientintdom = $intdom;
         $clientsameinst = $sameinst;
+        if ($clientsameinst) {
+            undef($clientremoteok);
+            undef(%clientprohibited);
+        } else {
+            $clientremoteok = &get_remote_hostable($currentdomainid);
+            %clientprohibited = &get_prohibited($currentdomainid);
+        }
         return 1;
     }
 }
@@ -8454,6 +8656,7 @@ sub sethost {
 	eq &Apache::lonnet::get_host_ip($hostid)) {
 	$currenthostid  =$hostid;
 	$currentdomainid=&Apache::lonnet::host_domain($hostid);
+        &set_client_info();
 #	&logthis("Setting hostid to $hostid, and domain to $currentdomainid");
     } else {
 	&logthis("Requested host id $hostid not an alias of ".
@@ -8530,6 +8733,32 @@ sub get_prohibited {
     return %prohibited;
 }
 
+sub get_remote_hostable {
+    my ($dom) = @_;
+    my $result;
+    if ($clientintdom) {
+        $result = 1;
+        my $remsessconf = &get_usersession_config($dom,'remotesession');
+        if (ref($remsessconf) eq 'HASH') {
+            if (ref($remsessconf->{'remote'}) eq 'HASH') {
+                if (ref($remsessconf->{'remote'}->{'excludedomain'}) eq 'ARRAY') {
+                    if (grep(/^\Q$clientintdom\E$/,@{$remsessconf->{'remote'}->{'excludedomain'}})) {
+                        $result = 0;
+                    }
+                }
+                if (ref($remsessconf->{'remote'}->{'includedomain'}) eq 'ARRAY') {
+                    if (grep(/^\Q$clientintdom\E$/,@{$remsessconf->{'remote'}->{'includedomain'}})) {
+                        $result = 1;
+                    } else {
+                        $result = 0;
+                    }
+                }
+            }
+        }
+    }
+    return $result;
+}
+
 sub distro_and_arch {
     return $dist.':'.$arch;
 }