netdev - [PATCH net] gre: do not keep the GRE header around in collect medata mode

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <208ed3349bdc26bb9af1fe7e8ff64895e0e2c088.1462974784.git.jbenc@redhat.com>
Date:	Wed, 11 May 2016 15:53:57 +0200
From:	Jiri Benc <jbenc@...hat.com>
To:	netdev@...r.kernel.org
Cc:	Pravin Shelar <pshelar@....org>,
	Simon Horman <simon.horman@...ronome.com>
Subject: [PATCH net] gre: do not keep the GRE header around in collect medata mode

For ipgre interface in collect metadata mode, it doesn't make sense for the
interface to be of ARPHRD_IPGRE type. The outer header of received packets
is not needed, as all the information from it is present in metadata_dst. We
already don't set ipgre_header_ops for collect metadata interfaces, which is
the only consumer of mac_header pointing to the outer IP header.

Just set the interface type to ARPHRD_NONE in collect metadata mode for
ipgre (not gretap, that still correctly stays ARPHRD_ETHER) and reset
mac_header.

Fixes: a64b04d86d14 ("gre: do not assign header_ops in collect metadata mode")
Fixes: 2e15ea390e6f4 ("ip_gre: Add support to collect tunnel metadata.")
Signed-off-by: Jiri Benc <jbenc@...hat.com>
---
 net/ipv4/ip_gre.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 205a2b8a5a84..4cc84212cce1 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -398,7 +398,10 @@ static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi)
 				  iph->saddr, iph->daddr, tpi->key);
 
 	if (tunnel) {
-		skb_pop_mac_header(skb);
+		if (tunnel->dev->type != ARPHRD_NONE)
+			skb_pop_mac_header(skb);
+		else
+			skb_reset_mac_header(skb);
 		if (tunnel->collect_md) {
 			__be16 flags;
 			__be64 tun_id;
@@ -1031,6 +1034,8 @@ static void ipgre_netlink_parms(struct net_device *dev,
 		struct ip_tunnel *t = netdev_priv(dev);
 
 		t->collect_md = true;
+		if (dev->type == ARPHRD_IPGRE)
+			dev->type = ARPHRD_NONE;
 	}
 }
 
-- 
1.8.3.1