Changeset 703

Timestamp:

01/18/16 10:12:04 (9 years ago)

Author:

Kris Deugau

Message:

/trunk

Switch to hand-crafting TXT records for export, instead of using tinydns'
native handling. Some idiot DNS clients (and some... less than experienced
IT support people) don't seem to like it autosplitting TXT records at
127 characters. So we'll split them by hand at 255 characters, and pray
nobody complains.

For mid-length DKIM key records, this generally means the record won't be
split at all, and for not-completely-loony SPF records, it will be split less.

Hooray for auditing checkboxes.

File:

• trunk/DNSDB.pm (modified) (1 diff)

trunk/DNSDB.pm

@@ -6240 +6240 @@
 
     ($host,$val) = __revswap($host,$val) if $revrec eq 'y';
-##fixme:  split v-e-r-y long TXT strings?  will need to do so for BIND export, at least
-    $val =~ s/:/\\072/g;        # may need to replace other symbols
-    print $datafile "'$host:$val:$ttl:$stamp:$loc\n" or die $!;
+# le sigh.  Some idiot DNS implementations don't seem to like tinydns autosplitting
+# long TXT records at 127 characters instead of 255.  Hand-crafting a record seems
+# to paper over the remote stupid.  We will NOT try to split on whitespace;  the
+# contents of a TXT record are opaque and clients who can't deal are even more broken
+# than the ones that don't like them split at 127 characters...  because BIND tries
+# to "intelligently" split TXT data, and abso-by-damn-lutely generates chunks <255
+# characters, and anything that can't interpret BIND's DNS responses has no business
+# trying to interpret DNS data at all.
+
+    print $datafile ":$host:16:";
+    my @txtsegs = $val =~ /.{1,255}/g;
+    foreach (@txtsegs) {
+      my $len = length($_);
+      s/:/\\072/g;
+      printf $datafile "\\%0.3o%s", $len, $_;
+    }
+    print $datafile ":$ttl:$stamp:$loc\n";
+
+#    $val =~ s/:/\\072/g;       # may need to replace other symbols
+#make this an option?
+#    print $datafile "'$host:$val:$ttl:$stamp:$loc\n" or die $!;
 
 # by-hand TXT