[3.11.y.z extended stable] Patch "{pktgen, xfrm} Update IPv4 header total len and checksum after" has been added to staging queue

Luis Henriques luis.henriques at canonical.com
Wed Dec 11 14:40:31 UTC 2013


This is a note to let you know that I have just added a patch titled

    {pktgen, xfrm} Update IPv4 header total len and checksum after

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 2d5472d57f77acd459334391a23aca3a445e220d Mon Sep 17 00:00:00 2001
From: "fan.du" <fan.du at windriver.com>
Date: Sun, 1 Dec 2013 16:28:48 +0800
Subject: {pktgen, xfrm} Update IPv4 header total len and checksum after
 tranformation

commit 3868204d6b89ea373a273e760609cb08020beb1a upstream.

commit a553e4a6317b2cfc7659542c10fe43184ffe53da ("[PKTGEN]: IPSEC support")
tried to support IPsec ESP transport transformation for pktgen, but acctually
this doesn't work at all for two reasons(The orignal transformed packet has
bad IPv4 checksum value, as well as wrong auth value, reported by wireshark)

- After transpormation, IPv4 header total length needs update,
  because encrypted payload's length is NOT same as that of plain text.

- After transformation, IPv4 checksum needs re-caculate because of payload
  has been changed.

With this patch, armmed pktgen with below cofiguration, Wireshark is able to
decrypted ESP packet generated by pktgen without any IPv4 checksum error or
auth value error.

pgset "flag IPSEC"
pgset "flows 1"

Signed-off-by: Fan Du <fan.du at windriver.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/core/pktgen.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index 9640972..d2c2e39 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -2515,6 +2515,8 @@ static int process_ipsec(struct pktgen_dev *pkt_dev,
 		if (x) {
 			int ret;
 			__u8 *eth;
+			struct iphdr *iph;
+
 			nhead = x->props.header_len - skb_headroom(skb);
 			if (nhead > 0) {
 				ret = pskb_expand_head(skb, nhead, 0, GFP_ATOMIC);
@@ -2536,6 +2538,11 @@ static int process_ipsec(struct pktgen_dev *pkt_dev,
 			eth = (__u8 *) skb_push(skb, ETH_HLEN);
 			memcpy(eth, pkt_dev->hh, 12);
 			*(u16 *) &eth[12] = protocol;
+
+			/* Update IPv4 header len as well as checksum value */
+			iph = ip_hdr(skb);
+			iph->tot_len = htons(skb->len - ETH_HLEN);
+			ip_send_check(iph);
 		}
 	}
 	return 1;
--
1.8.3.2





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