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Commit a1e67951 authored by Florian Westphal's avatar Florian Westphal Committed by Pablo Neira Ayuso
Browse files

netfilter: bridge: make BRNF_PKT_TYPE flag a bool 



nf_bridge_info->mask is used for several things, for example to
remember if skb->pkt_type was set to OTHER_HOST.

For a bridge, OTHER_HOST is expected case. For ip forward its a non-starter
though -- routing expects PACKET_HOST.

Bridge netfilter thus changes OTHER_HOST to PACKET_HOST before hook
invocation and then un-does it after hook traversal.

This information is irrelevant outside of br_netfilter.

After this change, ->mask now only contains flags that need to be
known outside of br_netfilter in fast-path.

Future patch changes mask into a 2bit state field in sk_buff, so that
we can remove skb->nf_bridge pointer for good and consider all remaining
places that access nf_bridge info content a not-so fastpath.

Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 3eaf4025

include/linux/netfilter_bridge.h

+0 −1
Original line number Diff line number Diff line
@@ -17,7 +17,6 @@ enum nf_br_hook_priorities { 


#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)



#define BRNF_PKT_TYPE			0x01

#define BRNF_BRIDGED_DNAT		0x02

#define BRNF_NF_BRIDGE_PREROUTING	0x08

include/linux/skbuff.h

+1 −0
Original line number Diff line number Diff line
@@ -171,6 +171,7 @@ struct nf_bridge_info { 
		BRNF_PROTO_8021Q,

		BRNF_PROTO_PPPOE

	} orig_proto;

	bool			pkt_otherhost;

	unsigned int		mask;

	struct net_device	*physindev;

	struct net_device	*physoutdev;

net/bridge/br_netfilter.c

+9 −9
Original line number Diff line number Diff line
@@ -282,9 +282,9 @@ static int br_nf_pre_routing_finish_ipv6(struct sk_buff *skb) 
	struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);

	struct rtable *rt;



	if (nf_bridge->mask & BRNF_PKT_TYPE) {

	if (nf_bridge->pkt_otherhost) {

		skb->pkt_type = PACKET_OTHERHOST;

		nf_bridge->mask ^= BRNF_PKT_TYPE;

		nf_bridge->pkt_otherhost = false;

	}

	nf_bridge->mask ^= BRNF_NF_BRIDGE_PREROUTING;
@@ -415,9 +415,9 @@ static int br_nf_pre_routing_finish(struct sk_buff *skb) 
	frag_max_size = IPCB(skb)->frag_max_size;

	BR_INPUT_SKB_CB(skb)->frag_max_size = frag_max_size;



	if (nf_bridge->mask & BRNF_PKT_TYPE) {

	if (nf_bridge->pkt_otherhost) {

		skb->pkt_type = PACKET_OTHERHOST;

		nf_bridge->mask ^= BRNF_PKT_TYPE;

		nf_bridge->pkt_otherhost = false;

	}

	nf_bridge->mask ^= BRNF_NF_BRIDGE_PREROUTING;

	if (dnat_took_place(skb)) {
@@ -503,7 +503,7 @@ static struct net_device *setup_pre_routing(struct sk_buff *skb) 


	if (skb->pkt_type == PACKET_OTHERHOST) {

		skb->pkt_type = PACKET_HOST;

		nf_bridge->mask |= BRNF_PKT_TYPE;

		nf_bridge->pkt_otherhost = true;

	}



	nf_bridge->mask |= BRNF_NF_BRIDGE_PREROUTING;
@@ -711,9 +711,9 @@ static int br_nf_forward_finish(struct sk_buff *skb) 
		}



		in = nf_bridge->physindev;

		if (nf_bridge->mask & BRNF_PKT_TYPE) {

		if (nf_bridge->pkt_otherhost) {

			skb->pkt_type = PACKET_OTHERHOST;

			nf_bridge->mask ^= BRNF_PKT_TYPE;

			nf_bridge->pkt_otherhost = false;

		}

		nf_bridge_update_protocol(skb);

	} else {
@@ -769,7 +769,7 @@ static unsigned int br_nf_forward_ip(const struct nf_hook_ops *ops, 


	if (skb->pkt_type == PACKET_OTHERHOST) {

		skb->pkt_type = PACKET_HOST;

		nf_bridge->mask |= BRNF_PKT_TYPE;

		nf_bridge->pkt_otherhost = true;

	}



	if (pf == NFPROTO_IPV4) {
@@ -927,7 +927,7 @@ static unsigned int br_nf_post_routing(const struct nf_hook_ops *ops, 
	 * about the value of skb->pkt_type. */

	if (skb->pkt_type == PACKET_OTHERHOST) {

		skb->pkt_type = PACKET_HOST;

		nf_bridge->mask |= BRNF_PKT_TYPE;

		nf_bridge->pkt_otherhost = true;

	}



	nf_bridge_pull_encap_header(skb);