Changeset 1054 for branches/stable/DNSDB.pm

Timestamp:

03/13/26 14:00:58 (27 hours ago)

Author:

Kris Deugau

Message:

/branches/stable

Merge CNAME collision

Location:

branches/stable

Files:

• . (modified) (1 prop)
• DNSDB.pm (modified) (15 diffs)

branches/stable/DNSDB.pm

@@ -33 +33 @@
 use Fcntl qw(:flock);
 use Time::TAI64 qw(:tai64);
+use Date::Parse;
 
 use vars qw($VERSION @ISA @EXPORT @EXPORT_OK %EXPORT_TAGS);
@@ -213 +214 @@
                 force_refresh   => 1,
                 lowercase       => 0,   # mangle as little as possible by default
+                # tinker with timestamps if adding or updating a record would
+                # cause overlapping CNAME and other in some way
+                coerce_cname_timestamp => 'none',
                 # show IPs and CIDR blocks as-is for reverse zones.  valid values are
                 # 'none' (default, show natural IP or CIDR)
@@ -275 +279 @@
     $self->{showrev_arpa} = 'none';
   }
+  if (!grep /$self->{coerce_cname_timestamp}/, ('none','adjust','full')) {
+    warn "Bad coerce_cname_timestamp setting $self->{coerce_cname_timestamp}, using default\n";
+    $self->{coerce_cname_timestamp} = 'none';
+  }
 
   # Try to connect to the DB, and initialize a number of handy globals.
@@ -561 +569 @@
 ## Record validation subs.
 ##
+
+# Check for name collisions relating to CNAMEs.  Needs to be called from all other validators.
+sub _cname_collision {
+  my $self = shift;
+  my $dbh = $self->{dbh};
+
+  my %args = @_;
+
+  my $hcheck = ($args{revrec} eq 'y' ? ${$args{val}} : ${$args{host}});
+  my $hfield = ($args{revrec} eq 'y' ? 'val' : 'host');
+
+  # $hcheck should be normalized by the time this sub is called.  Convert to the formal .arpa name for error reporting in reverse zones.
+  my $arpaname = '';
+  if ($args{revrec} eq 'y') {
+    $arpaname = NetAddr::IP->new($hcheck);
+##fixme:  more voodoo if global and/or per-user ARPA display mode flag set this way or that
+    $arpaname = _ZONE($arpaname, 'ZONE', 'r', '.').($arpaname->{isv6} ? '.ip6.arpa' : '.in-addr.arpa');
+  }
+
+  # The record type comparison is the only difference between two passes through this chunk of code.
+  # CNAME records require both passes, where other records only need the second one.  Downside is
+  # that returning error messages needs to check the loop variable on top of whatever else it references.
+  foreach my $tcompare ('<>', '=') {
+    next if $tcompare eq '<>' && ${$args{rectype}} != 5;
+
+    # Merging these sets of SQL statements is far too messy and doesn't reasonably
+    # allow for more fine-grained error/warning messages to be returned
+
+    # First lookup fails out collisions with records without timestamps or default records (which can not have timestamps)
+    my $sql = "SELECT count(*) FROM "._rectable($args{defrec}, $args{revrec}).
+        " WHERE "._recparent($args{defrec}, $args{revrec})." = ? AND type $tcompare 5 AND $hfield = ?";
+    my @lookupargs = ($args{id}, $hcheck);
+    $sql .= " AND stampactive = 'f'" if $args{defrec} eq 'n';
+    if ($args{update}) {
+      $sql .= " AND record_id <> ?";
+      push @lookupargs, $args{update};
+    }
+    my @t = $dbh->selectrow_array($sql, undef, @lookupargs);
+    if ($t[0] > 0) {
+      if ($tcompare eq '<>') {
+        return ('FAIL', "One or more non-CNAME records already exist for ".($args{revrec} eq 'y' ? $arpaname : $hcheck).
+                ".  CNAME records cannot use the same name as other records.");
+      } else {
+        return ('FAIL', "There is already a CNAME present for ".($args{revrec} eq 'y' ? $arpaname : $hcheck).
+                ".  Only one CNAME may be present for a given name.");
+      }
+    }
+
+    # By this point, all failure cases for default records have been checked.
+    # Default records cannot carry timestamps, so cannot have timestamp-based collisions
+    return ('OK','OK') if $args{defrec} ne 'n';
+
+    # Second lookup fails out various timestamp-exists collision cases when adding/updating with a timestamp
+    $sql = "SELECT count(*) FROM "._rectable($args{defrec}, $args{revrec}).
+        " WHERE "._recparent($args{defrec}, $args{revrec})." = ? AND type $tcompare 5 AND $hfield = ?".
+        " AND stampactive = 't'";
+    @lookupargs = ($args{id}, $hcheck);
+    if (${$args{stamp}} && ${$args{expires}}) {
+      $sql .= " AND expires = ?";
+      push @lookupargs, ${$args{expires}};
+      if ($self->{coerce_cname_timestamp} eq 'none') {
+        # no coercion means new valid-after < existing expires or new expires > existing valid-after will fail
+        $sql .= " AND ". (${$args{expires}} eq 'f' ? "expires = 't' AND stamp <= ?)" : "expires = 'f' AND stamp >= ?");
+        push @lookupargs, ${$args{stamp}};
+      }
+    }
+    if ($args{update}) {
+      $sql .= " AND record_id <> ?";
+      push @lookupargs, $args{update};
+    }
+    @t = $dbh->selectrow_array($sql, undef, @lookupargs);
+    if ($t[0] > 0) {
+      if ($tcompare eq '<>') {
+        return ('FAIL', "One or more non-CNAME records with timestamps already exist for ".($args{revrec} eq 'y' ? $arpaname : $hcheck).
+                ".  CNAME records must expire before or become valid after any records with the same name.");
+      } else {
+        return ('FAIL', "There is already a CNAME with a timestamp present for ".($args{revrec} eq 'y' ? $arpaname : $hcheck).
+                ".  Records with a matching name must expire before or become valid after this CNAME.");
+      }
+    }
+
+    # Third check starts retrieving actual timestamps to see if we need to,
+    # and then if we can, coerce the new/updated record's timestamp to match
+    $sql = "SELECT extract(epoch from stamp),expires,stamp < now() FROM "._rectable($args{defrec}, $args{revrec}).
+        " WHERE "._recparent($args{defrec}, $args{revrec})." = ? AND type $tcompare 5 AND $hfield = ?".
+        " AND stampactive = 't'";
+    @lookupargs = ($args{id}, $hcheck);
+    if ($args{update}) {
+      $sql .= " AND record_id <> ?";
+      push @lookupargs, $args{update};
+    }
+    if (${$args{stamp}}) {
+      $sql .= " ORDER BY stamp ".(${$args{expires}} eq 'f' ? 'ASC' : 'DESC' )." LIMIT 1";
+    } else {
+      $sql .= " ORDER BY stamp LIMIT 1";
+    }
+    @t = $dbh->selectrow_array($sql, undef, @lookupargs);
+    if (@t) {
+      # caller requested an expiry time
+      my $reqstamp = str2time(${$args{stamp}});
+      if (${$args{expires}} eq 'f') {
+        if ($reqstamp > $t[0]) {
+          # do nothing, new record goes valid after the expiring record we found
+        } else {
+          if ($self->{coerce_cname_timestamp} eq 'adjust') {
+            # coerce the valid-after timestamp
+            ${$args{stamp}} = strftime('%Y-%m-%d %H:%M:%S', localtime($t[0]));
+            return ('WARN', $typemap{${$args{rectype}}}." ".($args{update} ? 'updated' : 'added').
+                " with modified valid-after time;  conflicting expiring record found");
+          } else {
+            # New valid-after overlaps existing expiry, and not configured to adjust it
+            my $fill = ($tcompare eq '<>' ? ' CNAME, another record' : $typemap{${$args{rectype}}}.', a CNAME');
+            return ('FAIL', "Cannot ".($args{update} ? 'update' : 'add').$fill.
+                " with a valid-after time already exists for this name");
+          }
+        } # else ($reqstamp < $t[0])
+      } else {
+        if ($reqstamp < $t[0]) {
+          # do nothing, new record will expire before the one we found
+        } else {
+          if ($self->{coerce_cname_timestamp} eq 'adjust') {
+            if ($t[2] == 1) {
+              # found a valid-after, but it's in the past, so adding an expiring record to match doesn't make
+              # sense since it's effectively expired.
+##fixme:  should probably remove this case once we get around to stripping valid-after timestamps once exported as active
+              return ('FAIL', "Cannot ".($args{update} ? 'update' : 'add')." ".$typemap{${$args{rectype}}}.
+                ", an existing valid-after record is already active for this name");
+            } else {
+              # coerce the expiry timestamp
+              ${$args{stamp}} = strftime('%Y-%m-%d %H:%M:%S', localtime($t[0]));
+              return ('WARN', $typemap{${$args{rectype}}}." ".($args{update} ? 'updated' : 'added').
+                " with modified expiry time;  conflicting valid-after record found");
+            }
+          } else {
+            return ('FAIL', "Cannot ".($args{update} ? 'update' : 'add')." ".$typemap{${$args{rectype}}}.
+                ", another record with an overlapping valid-after timestamp already exists for this name");
+          }
+        }
+      } # args{expires} ne 'f'
+    } # if @t
+
+  } # each $tcompare
+
+  return ('OK', 'OK');
+} # _cname_collision()
 
 ## All of these subs take substantially the same arguments:
@@ -758 +911 @@
       return ('FAIL', "The bare zone name may not be a CNAME") if ${$args{host}} eq $pname || ${$args{host}} =~ /^\@/;
 
-##enhance:  Look up the passed value to see if it exists.  Ooo, fancy.
       return ('FAIL', $errstr) if ! _check_hostname_form(${$args{val}}, ${$args{rectype}}, $args{defrec}, $args{revrec});
+
     } # $zname !~ .rpz
   } # revzone eq 'n'
@@ -1616 +1769 @@
 
   return ('WARN', join("\n", $errstr, $warnmsg) ) if $warnmsg;
-  
+
   return ('OK','OK');
 } # done ALIAS record
@@ -2156 +2309 @@
       $cfg->{lowercase}         = $1 if /^lowercase\s*=\s*([a-z01]+)/i;
       $cfg->{showrev_arpa}      = $1 if /^showrev_arpa\s*=\s*([a-z]+)/i;
+      $cfg->{coerce_cname_timestamp}    = $1 if /^coerce_cname_timestamp\s*=\s*([a-z]+)/i;
       $cfg->{template_skip_0}   = $1 if /^template_skip_0\s*=\s*([a-z01]+)/i;
       $cfg->{template_skip_255} = $1 if /^template_skip_255\s*=\s*([a-z01]+)/i;
@@ -4694 +4848 @@
 
   my $expires = shift || '';
-  $expires = 1 if $expires eq 'until';  # Turn some special values into the appropriate booleans.
-  $expires = 0 if $expires eq 'after';
+  $expires = 't' if $expires eq 'until';        # Turn some special values into the appropriate booleans.
+  $expires = 'f' if $expires eq 'after';
+  $expires = 't' if $expires eq '1';
+  $expires = 'f' if $expires eq '0';
   my $stamp = shift;
   $stamp = '' if !$stamp;        # Timestamp should be a string at this point.
@@ -4705 +4861 @@
   return ('FAIL', "expires must be 1, 't', or 'until',  or 0, 'f', or 'after'")
         if ($stamp && !defined($expires))
-        || ($stamp && $expires ne '0' && $expires ne '1' && $expires ne 't' && $expires ne 'f');
+        || ($stamp && $expires ne 't' && $expires ne 'f');
 
   # Spaces are evil.
@@ -4745 +4901 @@
         host => $host, rectype => $rectype, val => $val, addr => $addr,
         dist => \$dist, port => \$port, weight => \$weight,
+        stamp => \$stamp, expires => \$expires,
         fields => \$fields, vallist => \@vallist);
 
   return ($retcode,$retmsg) if $retcode eq 'FAIL';
+
+  # Check for CNAME collisions.
+##fixme:  should trim the list of arguments, not all of these should be required for CNAME collision checking
+  my ($ccode,$cmsg) = _cname_collision($self, defrec => $defrec, revrec => $revrec, id => $id,
+        host => $host, rectype => $rectype, val => $val, addr => $addr,
+        dist => \$dist, port => \$port, weight => \$weight,
+        stamp => \$stamp, expires => \$expires,
+        fields => \$fields, vallist => \@vallist);
+
+  return ($ccode,$cmsg) if $ccode eq 'FAIL';
+
+  # If both the validator and CNAME collision check return warnings, glue them together
+  if ($ccode eq 'WARN') {
+    if ($retcode eq 'WARN') {
+      $retmsg .= "<br>\n$cmsg";
+    } else {
+      $retmsg = $cmsg;
+    }
+    $retcode = 'WARN';
+  }
 
   # Minor cleanup of invalid DNS labels
@@ -4806 +4983 @@
   $logdata{entry} .= "', TTL $ttl";
   $logdata{entry} .= ", location ".$self->getLoc($location)->{description} if $location;
-  $logdata{entry} .= ($expires ? ', expires at ' : ', valid after ').$stamp if $stamp;
+  $logdata{entry} .= ($expires eq 't' ? ', expires at ' : ', valid after ').$stamp if $stamp;
 
   # Allow transactions, and raise an exception on errors so we can catch it later.
@@ -4866 +5043 @@
 
   my $expires = shift || '';
-  $expires = 1 if $expires eq 'until';  # Turn some special values into the appropriate booleans.
-  $expires = 0 if $expires eq 'after';
+  $expires = 't' if $expires eq 'until';        # Turn some special values into the appropriate booleans.
+  $expires = 'f' if $expires eq 'after';
+  $expires = 't' if $expires eq '1';
+  $expires = 'f' if $expires eq '0';
   my $stamp = shift;
   $stamp = '' if !$stamp;        # Timestamp should be a string at this point.
@@ -4876 +5055 @@
   return ('FAIL', "expires must be 1, 't', or 'until',  or 0, 'f', or 'after'")
         if ($stamp && !defined($expires))
-        || ($stamp && $expires ne '0' && $expires ne '1' && $expires ne 't' && $expires ne 'f');
+        || ($stamp && $expires ne 't' && $expires ne 'f');
 
   # Spaces are evil.
@@ -4922 +5101 @@
         host => $host, rectype => $rectype, val => $val, addr => $addr,
         dist => \$dist, port => \$port, weight => \$weight,
+        stamp => \$stamp, expires => \$expires,
         fields => \$fields, vallist => \@vallist,
         update => $id);
 
   return ($retcode,$retmsg) if $retcode eq 'FAIL';
+
+  # Check for CNAME collisions.
+##fixme:  should trim the list of arguments, not all of these should be required for CNAME collision checking
+  my ($ccode,$cmsg) = _cname_collision($self, defrec => $defrec, revrec => $revrec,
+        id => ($defrec eq 'y' ? $oldrec->{group_id} : ($revrec eq 'n' ? $oldrec->{domain_id} : $oldrec->{rdns_id})),
+        host => $host, rectype => $rectype, val => $val, addr => $addr,
+        dist => \$dist, port => \$port, weight => \$weight,
+        stamp => \$stamp, expires => \$expires,
+        fields => \$fields, vallist => \@vallist,
+        update => $id);
+
+  return ($ccode,$cmsg) if $ccode eq 'FAIL';
+
+  # If both the validator and CNAME collision check return warnings, glue them together
+  if ($ccode eq 'WARN') {
+    if ($retcode eq 'WARN') {
+      $retmsg .= "<br>\n$cmsg";
+    } else {
+      $retmsg = $cmsg;
+    }
+    $retcode = 'WARN';
+  }
 
   # Minor cleanup of invalid DNS labels
@@ -5024 +5226 @@
   $logdata{entry} .= "', TTL $ttl";
   $logdata{entry} .= ", location ".$self->getLoc($location)->{description} if $location;
-  $logdata{entry} .= ($expires ? ', expires at ' : ', valid after ').$stamp if $stamp;
+  $logdata{entry} .= ($expires eq 't' ? ', expires at ' : ', valid after ').$stamp if $stamp;
 
   local $dbh->{AutoCommit} = 0;