vxlan: vxlan_rcv(): Drop unparsed

The code currently validates the VXLAN header in two ways: first by
comparing it with the set of reserved bits, constructed ahead of time
during the netdevice construction; and second by gradually clearing the
bits off a separate copy of VXLAN header, "unparsed". Drop the latter
validation method.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/4559f16c5664c189b3a4ee6f5da91f552ad4821c.1733412063.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index 92832a396ab795f2f6e4be5d8a976bed426cb85a..ff5684a2103a855c4ca03b3c83eb2f37d1e60728 100644 (file)
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -1670,7 +1670,6 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
        const struct vxlanhdr *vh;
        struct vxlan_dev *vxlan;
        struct vxlan_sock *vs;
-       struct vxlanhdr unparsed;
        struct vxlan_metadata _md;
        struct vxlan_metadata *md = &_md;
        __be16 protocol = htons(ETH_P_TEB);
@@ -1685,7 +1684,6 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
        if (reason)
                goto drop;
 
-       unparsed = *vxlan_hdr(skb);
        vh = vxlan_hdr(skb);
        /* VNI flag always required to be set */
        if (!(vh->vx_flags & VXLAN_HF_VNI)) {
@@ -1695,8 +1693,6 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
                /* Return non vxlan pkt */
                goto drop;
        }
-       unparsed.vx_flags &= ~VXLAN_HF_VNI;
-       unparsed.vx_vni &= ~VXLAN_VNI_MASK;
 
        vs = rcu_dereference_sk_user_data(sk);
        if (!vs)
@@ -1731,7 +1727,6 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
        if (vxlan->cfg.flags & VXLAN_F_GPE) {
                if (!vxlan_parse_gpe_proto(vh, &protocol))
                        goto drop;
-               unparsed.vx_flags &= ~VXLAN_GPE_USED_BITS;
                raw_proto = true;
        }
 
@@ -1745,8 +1740,6 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
                reason = vxlan_remcsum(skb, vxlan->cfg.flags);
                if (unlikely(reason))
                        goto drop;
-               unparsed.vx_flags &= ~VXLAN_HF_RCO;
-               unparsed.vx_vni &= VXLAN_VNI_MASK;
        }
 
        if (vxlan_collect_metadata(vs)) {
@@ -1769,19 +1762,12 @@ static int vxlan_rcv(struct sock *sk, struct sk_buff *skb)
                memset(md, 0, sizeof(*md));
        }
 
-       if (vxlan->cfg.flags & VXLAN_F_GBP) {
+       if (vxlan->cfg.flags & VXLAN_F_GBP)
                vxlan_parse_gbp_hdr(skb, vxlan->cfg.flags, md);
-               unparsed.vx_flags &= ~VXLAN_GBP_USED_BITS;
-       }
        /* Note that GBP and GPE can never be active together. This is
         * ensured in vxlan_dev_configure.
         */
 
-       if (unparsed.vx_flags || unparsed.vx_vni) {
-               reason = SKB_DROP_REASON_VXLAN_INVALID_HDR;
-               goto drop;
-       }
-
        if (!raw_proto) {
                reason = vxlan_set_mac(vxlan, vs, skb, vni);
                if (reason)