netfilter: nft_payload: restore vlan q-in-q match support

[ Upstream commit aff5c01fa1284d606f8e7cbdaafeef2511bb46c1 ]

Revert f6ae9f120dad ("netfilter: nft_payload: add C-VLAN support").

f41f72d09ee1 ("netfilter: nft_payload: simplify vlan header handling")
already allows to match on inner vlan tags by subtract the vlan header
size to the payload offset which has been popped and stored in skbuff
metadata fields.

Fixes: f6ae9f120dad ("netfilter: nft_payload: add C-VLAN support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c
index 02327ffebc4951e3fc42ce7a19fe12af7b484dcf..4192f0e3665542b3cf514bae54d8a89677d0b4bb 100644 (file)
--- a/net/netfilter/nft_payload.c
+++ b/net/netfilter/nft_payload.c
@@ -45,36 +45,27 @@ nft_payload_copy_vlan(u32 *d, const struct sk_buff *skb, u8 offset, u8 len)
        int mac_off = skb_mac_header(skb) - skb->data;
        u8 *vlanh, *dst_u8 = (u8 *) d;
        struct vlan_ethhdr veth;
-       u8 vlan_hlen = 0;
-
-       if ((skb->protocol == htons(ETH_P_8021AD) ||
-            skb->protocol == htons(ETH_P_8021Q)) &&
-           offset >= VLAN_ETH_HLEN && offset < VLAN_ETH_HLEN + VLAN_HLEN)
-               vlan_hlen += VLAN_HLEN;
 
        vlanh = (u8 *) &veth;
-       if (offset < VLAN_ETH_HLEN + vlan_hlen) {
+       if (offset < VLAN_ETH_HLEN) {
                u8 ethlen = len;
 
-               if (vlan_hlen &&
-                   skb_copy_bits(skb, mac_off, &veth, VLAN_ETH_HLEN) < 0)
-                       return false;
-               else if (!nft_payload_rebuild_vlan_hdr(skb, mac_off, &veth))
+               if (!nft_payload_rebuild_vlan_hdr(skb, mac_off, &veth))
                        return false;
 
-               if (offset + len > VLAN_ETH_HLEN + vlan_hlen)
-                       ethlen -= offset + len - VLAN_ETH_HLEN - vlan_hlen;
+               if (offset + len > VLAN_ETH_HLEN)
+                       ethlen -= offset + len - VLAN_ETH_HLEN;
 
-               memcpy(dst_u8, vlanh + offset - vlan_hlen, ethlen);
+               memcpy(dst_u8, vlanh + offset, ethlen);
 
                len -= ethlen;
                if (len == 0)
                        return true;
 
                dst_u8 += ethlen;
-               offset = ETH_HLEN + vlan_hlen;
+               offset = ETH_HLEN;
        } else {
-               offset -= VLAN_HLEN + vlan_hlen;
+               offset -= VLAN_HLEN;
        }
 
        return skb_copy_bits(skb, offset + mac_off, dst_u8, len) == 0;