Changeset 709

Timestamp:

03/09/16 15:38:09 (9 years ago)

Author:

Kris Deugau

Message:

/trunk

Tweak addLoc() to optionally accept a suggested or required location
ID and a flag to indicate of the ID is "must choose this or fail" or
"next available after this". Update the automatic-location-ID-finder
code to start with the requested ID.

Location:

trunk

Files:

• DNSDB.pm (modified) (4 diffs)
• dns.cgi (modified) (1 diff)

trunk/DNSDB.pm

@@ -3707 +3707 @@
   my $self = shift;
   my $dbh = $self->{dbh};
-  my $grp = shift;
-  my $shdesc = shift;
-  my $comments = shift;
-  my $iplist = shift;
+  my %args = @_;
+
+  my $grp = $args{group};
+  my $shdesc = $args{desc};
+  my $comments = $args{comments};
+  my $iplist = $args{iplist};
 
   # $shdesc gets set to the generated location ID if possible, but these can be de-undefined here.
@@ -3716 +3718 @@
   $iplist = '' if !$iplist;
 
-  my $loc;
+  # allow requesting a specific location entry.
+  my $loc = $args{loc};
 
   # Generate a location ID.  This is, by spec, a two-character widget.  We'll use [a-z][a-z]
   # for now;  676 locations should satisfy all but the largest of the huge networks.
-  # Not sure whether these are case-sensitive, or what other rules might apply - in any case
-  # the absolute maximum is 16K (256*256) since it's parsed by tinydns as a two-character field.
-
-  # and just to be as clear as possible;  as per http://cr.yp.to/djbdns/tinydns-data.html:
+
+  # just to be as clear as possible;  as per http://cr.yp.to/djbdns/tinydns-data.html:
 
 #For versions 1.04 and above: You may include a client location on each line. The line is ignored for clients 
@@ -3732 +3733 @@
 #means that IP addresses starting with ipprefix are in location lo. lo is a sequence of one or two ASCII letters.
 
-  # so locations could probably include both upper and lower case.
+  # this has been confirmed by experiment;  locations "lo", "Lo", and "lO" are all distinct.
 
 # add just after "my $origloc = $loc;":
@@ -3754 +3755 @@
   eval {
     # Get the "last" location.  Note this is the only use for loc_id, because selecting on location Does Funky Things
-    ($loc) = $dbh->selectrow_array("SELECT location FROM locations ORDER BY loc_id DESC LIMIT 1");
-    ($loc) = ($loc =~ /^(..)/) if $loc;
-    my $origloc = $loc;
-    $loc = 'aa' if !$loc;       
+    my ($newloc) = $dbh->selectrow_array("SELECT location FROM locations ORDER BY loc_id DESC LIMIT 1");
+
+    no warnings qw(uninitialized);
+
+    my $ecnt = $dbh->prepare("SELECT count(*) FROM locations WHERE location LIKE ?");
+
+    if ($loc) {
+      $ecnt->execute($loc);
+      if (($ecnt->fetchrow_array())[0]) {
+        # too bad, so sad, requested location is unavailable.
+##fixme:  known failure case:  caller requests a location ID that is not two characters.
+        die "Requested location is already defined\n" if $args{reqonly};
+        # fall back to autoincrement
+      }
+      $newloc = $loc;
+    }
+
+    # Either the requested location ID is unavailable and the caller isn't too attached
+    # to it, OR, the caller hasn't specified a location ID.  (The second case should be
+    # far more common.)  Find the "next available" location identifier.
+
+    ($newloc) = ($newloc =~ /^(..)/) if $newloc;
+    my $origloc = $newloc;
+    $newloc = 'aa' if !$newloc; 
     # Make a change...
-    $loc++;
     # ... and keep changing if it exists
-    while ($dbh->selectrow_array("SELECT count(*) FROM locations WHERE location LIKE ?", undef, ($loc.'%'))) {
-      $loc++;
-      ($loc) = ($loc =~ /^(..)/);
-      die "too many locations in use, can't add another one\n" if $loc eq $origloc;
+    while ($dbh->selectrow_array("SELECT count(*) FROM locations WHERE location LIKE ?", undef, ($newloc.'%'))) {
+      $newloc++;
+      ($newloc) = ($newloc =~ /^(..)/);
+      die "too many locations in use, can't add another one\n" if $newloc eq $origloc;
 ##fixme: really need to handle this case faster somehow
 #if $loc eq $origloc die "<thwap> bad admin:  all locations used, your network is too fragmented";
     }
-    # And now we should have a unique location.  tinydns fundamentally limits the
-    # number of these but there's no doc on what characters are valid.
-    $shdesc = $loc if !$shdesc;
+    # And now we should have a unique location.
+    $shdesc = $newloc if !$shdesc;
     $dbh->do("INSERT INTO locations (location, group_id, iplist, description, comments) VALUES (?,?,?,?,?)", 
-        undef, ($loc, $grp, $iplist, $shdesc, $comments) );
+        undef, ($newloc, $grp, $iplist, $shdesc, $comments) );
     $self->_log(entry => "Added location ($shdesc, '$iplist')");
+    $loc = $newloc;
     $dbh->commit;
   };

trunk/dns.cgi

@@ -1525 +1525 @@
         unless ($permissions{admin} || $permissions{location_create});
 
-    my ($code,$msg) = $dnsdb->addLoc($curgroup, $webvar{locname}, $webvar{comments}, $webvar{iplist});
+    my ($code,$msg) = $dnsdb->addLoc(group => $curgroup, desc => $webvar{locname},
+        comments => $webvar{comments}, iplist => $webvar{iplist});
 
     if ($code eq 'OK' || $code eq 'WARN') {