Handle TFTP ERROR from client
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>
diff --git a/slirp/tftp.c b/slirp/tftp.c
index 082f5d0..12dd344 100644
--- a/slirp/tftp.c
+++ b/slirp/tftp.c
@@ -264,6 +264,12 @@
size_t prefix_len;
char *req_fname;
+ /* check if a session already exists and if so terminate it */
+ s = tftp_session_find(slirp, tp);
+ if (s >= 0) {
+ tftp_session_terminate(&slirp->tftp_sessions[s]);
+ }
+
s = tftp_session_allocate(slirp, tp);
if (s < 0) {
@@ -385,6 +391,19 @@
}
}
+static void tftp_handle_error(Slirp *slirp, struct tftp_t *tp, int pktlen)
+{
+ int s;
+
+ s = tftp_session_find(slirp, tp);
+
+ if (s < 0) {
+ return;
+ }
+
+ tftp_session_terminate(&slirp->tftp_sessions[s]);
+}
+
void tftp_input(struct mbuf *m)
{
struct tftp_t *tp = (struct tftp_t *)m->m_data;
@@ -397,5 +416,9 @@
case TFTP_ACK:
tftp_handle_ack(m->slirp, tp, m->m_len);
break;
+
+ case TFTP_ERROR:
+ tftp_handle_error(m->slirp, tp, m->m_len);
+ break;
}
}
