From c56eb57316ac0094aa2b5b805762d239a18f0c63 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Stefan=20Br=C3=BCns?= <stefan.bruens@rwth-aachen.de>
Date: Fri, 28 Aug 2015 10:15:54 +0200
Subject: [PATCH] net: Fix parsing of Bootp/DHCP option 0 (Pad)
MIME-Version: 1.0
Content-Type: text/plain; charset=utf8
Content-Transfer-Encoding: 8bit
Pad has no len byte, so the normal parsing code fails.
Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
---
net/bootp.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/net/bootp.c b/net/bootp.c
index 93eff87246..1316f00dd8 100644
--- a/net/bootp.c
+++ b/net/bootp.c
@@ -776,6 +776,9 @@ static void dhcp_process_options(uchar *popt, struct bootp_hdr *bp)
while (popt < end && *popt != 0xff) {
oplen = *(popt + 1);
switch (*popt) {
+ case 0:
+ oplen = -1; /* Pad omits len byte */
+ break;
case 1:
net_copy_ip(&net_netmask, (popt + 2));
break;
@@ -879,7 +882,13 @@ static int dhcp_message_type(unsigned char *popt)
while (*popt != 0xff) {
if (*popt == 53) /* DHCP Message Type */
return *(popt + 2);
- popt += *(popt + 1) + 2; /* Scan through all options */
+ if (*popt == 0) {
+ /* Pad */
+ popt += 1;
+ } else {
+ /* Scan through all options */
+ popt += *(popt + 1) + 2;
+ }
}
return -1;
}
--
2.39.5