bfe4e17242
If a PXE client only wants to find out the size of a file, it will open the file and then abort the transfer by sending a TFTP ERROR packet. The ERROR packet should cause qemu to terminate the session. If not, the sessions will soon run out and cause timeouts in the client. Also, if a TFTP session already exists with same IP/UDP port, it should be terminated when a new RRQ is received, instead of creating a duplicate (which will never be used). A patch for gPXE to send the ERROR packet is also being submitted to gPXE. Together they resolve slowness/hanging when booting pxegrub from qemu's internal TFTP server. The patch from Milan Plzik to return after sending OACK is also required for a complete fix. Signed-off-by: Thomas Horsten <thomas@horsten.com> Signed-off-by: Milan Plzik <milan.plzik@gmail.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>