[net-next PATCH RFC 3/3] ip_vti/ip6_vti: Preserve skb->mark after rcv_cb call

Alexander Duyck
2015-05-26T22:41:30Z

The vti6_rcv_cb and vti_rcv_cb calls were leaving the skb->mark modified
after completing the function. This resulted in the original skb->mark
value being lost. Since we only need skb->mark to be set for
xfrm_policy_check we can pull the assignment into the rcv_cb calls and then
just restore the original mark after xfrm_policy_check has been completed.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
---
net/ipv4/ip_vti.c | 9 +++++++--
net/ipv6/ip6_vti.c | 9 +++++++--
2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/net/ipv4/ip_vti.c b/net/ipv4/ip_vti.c
index 4c318e1c13c8..0c152087ca15 100644
--- a/net/ipv4/ip_vti.c
+++ b/net/ipv4/ip_vti.c
@@ -65,7 +65,6 @@ static int vti_input(struct sk_buff *skb, int nexthdr, __be32 spi,
goto drop;

XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = tunnel;
- skb->mark = be32_to_cpu(tunnel->parms.i_key);

return xfrm_input(skb, nexthdr, spi, encap_type);
}
@@ -91,6 +90,8 @@ static int vti_rcv_cb(struct sk_buff *skb, int err)
struct pcpu_sw_netstats *tstats;
struct xfrm_state *x;
struct ip_tunnel *tunnel = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4;
+ u32 orig_mark = skb->mark;
+ int ret;

if (!tunnel)
return 1;
@@ -107,7 +108,11 @@ static int vti_rcv_cb(struct sk_buff *skb, int err)
x = xfrm_input_state(skb);
family = x->inner_mode->afinfo->family;

- if (!xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family))
+ skb->mark = be32_to_cpu(tunnel->parms.i_key);
+ ret = xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family);
+ skb->mark = orig_mark;
+
+ if (!ret)
return -EPERM;

skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(skb->dev)));
diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c
index 104de4da3ff3..ff3bd863fa03 100644
--- a/net/ipv6/ip6_vti.c
+++ b/net/ipv6/ip6_vti.c
@@ -322,7 +322,6 @@ static int vti6_rcv(struct sk_buff *skb)
}

XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = t;
- skb->mark = be32_to_cpu(t->parms.i_key);

rcu_read_unlock();

@@ -342,6 +341,8 @@ static int vti6_rcv_cb(struct sk_buff *skb, int err)
struct pcpu_sw_netstats *tstats;
struct xfrm_state *x;
struct ip6_tnl *t = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6;
+ u32 orig_mark = skb->mark;
+ int ret;

if (!t)
return 1;
@@ -358,7 +359,11 @@ static int vti6_rcv_cb(struct sk_buff *skb, int err)
x = xfrm_input_state(skb);
family = x->inner_mode->afinfo->family;

- if (!xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family))
+ skb->mark = be32_to_cpu(t->parms.i_key);
+ ret = xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family);
+ skb->mark = orig_mark;
+
+ if (!ret)
return -EPERM;

skb_scrub_packet(skb, !net_eq(t->net, dev_net(skb->dev)));