[syslinux] patch to deal with empty filenames

[Kevin D. Clark]

Hi,

I have a tftp client that sends out a tftp file request with an empty
(but null terminated) filename.  IMHO this is a bug, but I still need
to be able to use TFTP with this client.  Modifying the client is out
of the question at this point.

To deal with this situation I modified tftp-hpa in what I hope is an
unobtrusive manner -- I basically modified the code to map ""
filenames into the string "blank".  I believe that this will allow
users to use tftp-hpa's filename remapping capability as well (but I
haven't tried this).

This modification causes one warning associated with "const" to be
emitted.  I am all for making code "const-correct" and am even willing
to do this work if the maintainers of tftp-hpa want me to do this.
Before I embark on this task, can I get a feel for what people think
of this patch?

Regards,

--kevin

PS  Incidently, I couldn't get tftp-hpa-0.37 to configure on my Fedora
    Core 1 box.  I can send the log if this is useful.




$ diff -Naur  tftp-hpa-0.36/tftpd/tftpd.c tftp-hpa-0.36-kevin/tftpd/tftpd.c
--- tftp-hpa-0.36/tftpd/tftpd.c 2004-07-12 17:42:37.000000000 -0400
+++ tftp-hpa-0.36-kevin/tftpd/tftpd.c   2004-08-03 15:37:18.000000000 -0400
@@ -736,10 +736,19 @@
   argn = 0;
   end = (char *)tp + size;
  
+  /*
+   *  Hack to deal with empty filenames.
+   */
+  if (origfilename < end && *origfilename == '\000') {
+    origfilename = "blank";
+  }
+
+
+  while ( cp < end ) {
+
   while ( cp < end && *cp ) {
-    do {
       cp++;
-    } while (cp < end && *cp);
+    }
      
     if ( *cp ) {
       nak(EBADOP, "Request not null-terminated");