loader: tftp: Don't let tftp timeout

When we load a kernel or module we open/close it a few times.
Since we're using the same port number each time and that we requested
the same file the ACK that we send are valid on the server side and the
server send us the file multiple times.
This makes tftp loading time very inconsistant due to the UDP "flood" that
we have to process.

Reviewed by:	imp, tsoome
MFC after:	2 weeks
Sponsored by:	Beckhoff Automation GmbH & Co. KG
Differential Revision:	https://reviews.freebsd.org/D33407

1 files changed, 5 insertions, 1 deletions

diff --git a/stand/libsa/tftp.c b/stand/libsa/tftp.c
index 78eedddcb1f6..dcfce29a9968 100644
--- a/stand/libsa/tftp.c
+++ b/stand/libsa/tftp.c
@@ -114,6 +114,8 @@ struct tftp_handle {
 	unsigned long	tftp_tsize;
 	void		*pkt;
 	struct tftphdr	*tftp_hdr;
+	char		*tftp_cache;
+	bool		lastacksent;
 };
 
 struct tftprecv_extra {
@@ -378,6 +380,7 @@ tftp_makereq(struct tftp_handle *h)
 			if (res < h->tftp_blksize) {
 				h->islastblock = 1;	/* very short file */
 				tftp_sendack(h, h->currblock);
+				h->lastacksent = true;
 			}
 			return (0);
 		}
@@ -594,7 +597,8 @@ tftp_close(struct open_file *f)
 	struct tftp_handle *tftpfile;
 	tftpfile = f->f_fsdata;
 
-	/* let it time out ... */
+	if (tftpfile->lastacksent == false)
+		tftp_senderr(tftpfile, 0, "No error: file closed");
 
 	if (tftpfile) {
 		free(tftpfile->path);