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

Revert f6ae9f120d ("netfilter: nft_payload: add C-VLAN support").

f41f72d09e ("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: f6ae9f120d ("netfilter: nft_payload: add C-VLAN support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Pablo Neira Ayuso 2024-05-09 23:02:24 +02:00
parent c1193d9bbb
commit aff5c01fa1

View File

@ -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;