[PATCH net 0/2] net: improve vxlan option process in net_sched and lwtunnel

[PATCH net 0/2] net: improve vxlan option process in net_sched and lwtunnel

[Xin Long]

This patch is to do some mask when setting vxlan option in net_sched
and lwtunnel, so that only available bits can be set on vxlan md gbp.

This would help when users don't know exactly vxlan's gbp bits, and
avoid some mismatch because of some unavailable bits set by users.

Xin Long (2):
  net: sched: only keep the available bits when setting vxlan md->gbp
  lwtunnel: only keep the available bits when setting vxlan md->gbp

 include/net/vxlan.h        | 3 +++
 net/ipv4/ip_tunnel_core.c  | 1 +
 net/sched/act_tunnel_key.c | 1 +
 net/sched/cls_flower.c     | 4 +++-
 4 files changed, 8 insertions(+), 1 deletion(-)

-- 
2.1.0

[PATCH net 1/2] net: sched: only keep the available bits when setting vxlan md->gbp

[Xin Long]

As we can see from vxlan_build/parse_gbp_hdr(), when processing metadata
on vxlan rx/tx path, only dont_learn/policy_applied/policy_id fields can
be set to or parse from the packet for vxlan gbp option.

So we'd better do the mask when set it in act_tunnel_key and cls_flower.
Otherwise, when users don't know these bits, they may configure with a
value which can never be matched.

Reported-by: Shuang Li <shuali@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
 include/net/vxlan.h        | 3 +++
 net/sched/act_tunnel_key.c | 1 +
 net/sched/cls_flower.c     | 4 +++-
 3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/include/net/vxlan.h b/include/net/vxlan.h
index 3a41627c..08537aa 100644
--- a/include/net/vxlan.h
+++ b/include/net/vxlan.h
@@ -121,6 +121,9 @@ struct vxlanhdr_gbp {
 #define VXLAN_GBP_POLICY_APPLIED	(BIT(3) << 16)
 #define VXLAN_GBP_ID_MASK		(0xFFFF)
 
+#define VXLAN_GBP_MASK (VXLAN_GBP_DONT_LEARN | VXLAN_GBP_POLICY_APPLIED | \
+			VXLAN_GBP_ID_MASK)
+
 /*
  * VXLAN Generic Protocol Extension (VXLAN_F_GPE):
  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
diff --git a/net/sched/act_tunnel_key.c b/net/sched/act_tunnel_key.c
index 536c4bc..37f1e10 100644
--- a/net/sched/act_tunnel_key.c
+++ b/net/sched/act_tunnel_key.c
@@ -156,6 +156,7 @@ tunnel_key_copy_vxlan_opt(const struct nlattr *nla, void *dst, int dst_len,
 		struct vxlan_metadata *md = dst;
 
 		md->gbp = nla_get_u32(tb[TCA_TUNNEL_KEY_ENC_OPT_VXLAN_GBP]);
+		md->gbp &= VXLAN_GBP_MASK;
 	}
 
 	return sizeof(struct vxlan_metadata);
diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index 19a8fa2..fed18fd 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -1175,8 +1175,10 @@ static int fl_set_vxlan_opt(const struct nlattr *nla, struct fl_flow_key *key,
 		return -EINVAL;
 	}
 
-	if (tb[TCA_FLOWER_KEY_ENC_OPT_VXLAN_GBP])
+	if (tb[TCA_FLOWER_KEY_ENC_OPT_VXLAN_GBP]) {
 		md->gbp = nla_get_u32(tb[TCA_FLOWER_KEY_ENC_OPT_VXLAN_GBP]);
+		md->gbp &= VXLAN_GBP_MASK;
+	}
 
 	return sizeof(*md);
 }
-- 
2.1.0

[PATCH net 2/2] lwtunnel: only keep the available bits when setting vxlan md->gbp

[Xin Long]

As we can see from vxlan_build/parse_gbp_hdr(), when processing metadata
on vxlan rx/tx path, only dont_learn/policy_applied/policy_id fields can
be set to or parse from the packet for vxlan gbp option.

So do the mask when set it in lwtunnel, as it does in act_tunnel_key and
cls_flower.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
 net/ipv4/ip_tunnel_core.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c
index 75c6013..b2ea1a8 100644
--- a/net/ipv4/ip_tunnel_core.c
+++ b/net/ipv4/ip_tunnel_core.c
@@ -554,6 +554,7 @@ static int ip_tun_parse_opts_vxlan(struct nlattr *attr,
 
 		attr = tb[LWTUNNEL_IP_OPT_VXLAN_GBP];
 		md->gbp = nla_get_u32(attr);
+		md->gbp &= VXLAN_GBP_MASK;
 		info->key.tun_flags |= TUNNEL_VXLAN_OPT;
 	}
 
-- 
2.1.0

Re: [PATCH net 0/2] net: improve vxlan option process in net_sched and lwtunnel

[David Miller]

From: Xin Long <lucien.xin@gmail.com>
Date: Sun, 13 Sep 2020 19:51:49 +0800

> This patch is to do some mask when setting vxlan option in net_sched
> and lwtunnel, so that only available bits can be set on vxlan md gbp.
> 
> This would help when users don't know exactly vxlan's gbp bits, and
> avoid some mismatch because of some unavailable bits set by users.

Series applied, thank you.