From 258ccd68170b7279ec7d4805c7b914c90374e711 Mon Sep 17 00:00:00 2001
From: Jason Liu <r64343@freescale.com>
Date: Sun, 14 Nov 2010 12:23:09 +0800
Subject: [PATCH] net: Fix potential empty DHCP Parameter Request List

Can't get IP address with dhcp due to the dhcp server not
allow the empty param list request under some network env

This patch is based on Gray Remlin's initial patch.

Signed-off-by: Jason Liu <r64343@freescale.com>
Signed-off-by: Gray Remlin <g_remlin@rocketmail.com>
---
 net/bootp.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/bootp.c b/net/bootp.c
index e679f8b7f87..1a717867d48 100644
--- a/net/bootp.c
+++ b/net/bootp.c
@@ -456,6 +456,10 @@ static int DhcpExtended (u8 * e, int message_type, IPaddr_t ServerID, IPaddr_t R
 	*e++  = 42;
 	*cnt += 1;
 #endif
+	/* no options, so back up to avoid sending an empty request list */
+	if (*cnt == 0)
+		e -= 2;
+
 	*e++  = 255;		/* End of the list */
 
 	/* Pad to minimal length */
-- 
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