From 8cca168fc73058bf8b9bc6f6858ca4b38e5fde16 Mon Sep 17 00:00:00 2001
From: "H. Peter Anvin" <hpa@zytor.com>
Date: Wed, 27 Feb 2008 10:53:40 -0800
Subject: [PATCH] PXELINUX: make TFTP work without any OACK

Make the TFTP stack handle the case where no options are acknowledged,
so we don't even get an OACK; instead we get the first data packet
immediately.
---
 pxelinux.asm | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/pxelinux.asm b/pxelinux.asm
index 8ab223e..a6a847d 100644
--- a/pxelinux.asm
+++ b/pxelinux.asm
@@ -1286,14 +1286,24 @@ searchdir:
 		sub cx,2		; Too short?
 		jb .failure
 		lodsw			; Block number
-		cmp ax,1
+		cmp ax,htons(1)
 		jne .failure
 		mov [bx+tftp_lastpkt],ax
 		cmp cx,TFTP_BLOCKSIZE
 		ja .err_reply		; Corrupt...
-		je .unknown_size
+		je .not_eof
+		; This was the final EOF packet, already...
+		; We know the filesize, but we also want to ack the
+		; packet and set the EOF flag.
 		mov [bx+tftp_filesize],ecx
-.unknown_size:	mov [bx+tftp_bytesleft],cx
+		mov byte [bx+tftp_goteof],1
+		push si
+		mov si,bx
+		; AX = htons(1) already
+		call ack_packet
+		pop si
+.not_eof:
+		mov [bx+tftp_bytesleft],cx
 		mov ax,pktbuf_seg
 		push es
 		mov es,ax
-- 
2.7.4