From f38d669aab337e496e803d56ab22d09b309a902f Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Tue, 23 Nov 2021 12:50:31 +0100 Subject: [PATCH] netfilter: bridge: add support for pppoe filtering [ Upstream commit 28b78ecffea8078d81466b2e01bb5a154509f1ba ] This makes 'bridge-nf-filter-pppoe-tagged' sysctl work for bridged traffic. Looking at the original commit it doesn't appear this ever worked: static unsigned int br_nf_post_routing(unsigned int hook, struct sk_buff **pskb, [..] if (skb->protocol == htons(ETH_P_8021Q)) { skb_pull(skb, VLAN_HLEN); skb->network_header += VLAN_HLEN; + } else if (skb->protocol == htons(ETH_P_PPP_SES)) { + skb_pull(skb, PPPOE_SES_HLEN); + skb->network_header += PPPOE_SES_HLEN; } [..] NF_HOOK(... POST_ROUTING, ...) ... but the adjusted offsets are never restored. The alternative would be to rip this code out for good, but otoh we'd have to keep this anyway for the vlan handling (which works because vlan tag info is in the skb, not the packet payload). Reported-and-tested-by: Amish Chana Fixes: 516299d2f5b6f97 ("[NETFILTER]: bridge-nf: filter bridged IPv4/IPv6 encapsulated in pppoe traffic") Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- net/bridge/br_netfilter_hooks.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/net/bridge/br_netfilter_hooks.c b/net/bridge/br_netfilter_hooks.c index 8edfb98..68c0d0f 100644 --- a/net/bridge/br_netfilter_hooks.c +++ b/net/bridge/br_netfilter_hooks.c @@ -743,6 +743,9 @@ static int br_nf_dev_queue_xmit(struct net *net, struct sock *sk, struct sk_buff if (nf_bridge->frag_max_size && nf_bridge->frag_max_size < mtu) mtu = nf_bridge->frag_max_size; + nf_bridge_update_protocol(skb); + nf_bridge_push_encap_header(skb); + if (skb_is_gso(skb) || skb->len + mtu_reserved <= mtu) { nf_bridge_info_free(skb); return br_dev_queue_push_xmit(net, sk, skb); @@ -760,8 +763,6 @@ static int br_nf_dev_queue_xmit(struct net *net, struct sock *sk, struct sk_buff IPCB(skb)->frag_max_size = nf_bridge->frag_max_size; - nf_bridge_update_protocol(skb); - data = this_cpu_ptr(&brnf_frag_data_storage); if (skb_vlan_tag_present(skb)) { @@ -789,8 +790,6 @@ static int br_nf_dev_queue_xmit(struct net *net, struct sock *sk, struct sk_buff IP6CB(skb)->frag_max_size = nf_bridge->frag_max_size; - nf_bridge_update_protocol(skb); - data = this_cpu_ptr(&brnf_frag_data_storage); data->encap_size = nf_bridge_encap_header_len(skb); data->size = ETH_HLEN + data->encap_size; -- 2.7.4