Commit f12064d1 authored by Florian Westphal's avatar Florian Westphal Committed by Pablo Neira Ayuso
Browse files

bridge: reduce size of input cb to 16 bytes 



Reduce size of br_input_skb_cb from 24 to 16 bytes by
using bitfield for those values that can only be 0 or 1.

igmp is the igmp type value, so it needs to be at least u8.

Furthermore, the bridge currently relies on step-by-step initialization
of br_input_skb_cb fields as the skb passes through the stack.

Explicitly zero out the bridge input cb instead, this avoids having to
review/validate that no BR_INPUT_SKB_CB(skb)->foo test can see a
'random' value from previous protocol cb.

AFAICS all current fields are always set up before they are read again,
so this is not a bug fix.

Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Acked-by: default avatarDavid S. Miller <davem@davemloft.net>
Acked-by: default avatarNikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 26f7fe4a

net/bridge/br_arp_nd_proxy.c

+9 −9
Original line number Diff line number Diff line
@@ -131,7 +131,7 @@ void br_do_proxy_suppress_arp(struct sk_buff *skb, struct net_bridge *br, 
	u8 *arpptr, *sha;

	__be32 sip, tip;



	BR_INPUT_SKB_CB(skb)->proxyarp_replied = false;

	BR_INPUT_SKB_CB(skb)->proxyarp_replied = 0;



	if ((dev->flags & IFF_NOARP) ||

	    !pskb_may_pull(skb, arp_hdr_len(dev)))
@@ -161,7 +161,7 @@ void br_do_proxy_suppress_arp(struct sk_buff *skb, struct net_bridge *br, 
			return;

		if (ipv4_is_zeronet(sip) || sip == tip) {

			/* prevent flooding to neigh suppress ports */

			BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;

			BR_INPUT_SKB_CB(skb)->proxyarp_replied = 1;

			return;

		}

	}
@@ -181,7 +181,7 @@ void br_do_proxy_suppress_arp(struct sk_buff *skb, struct net_bridge *br, 
		/* its our local ip, so don't proxy reply

		 * and don't forward to neigh suppress ports

		 */

		BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;

		BR_INPUT_SKB_CB(skb)->proxyarp_replied = 1;

		return;

	}
@@ -217,7 +217,7 @@ void br_do_proxy_suppress_arp(struct sk_buff *skb, struct net_bridge *br, 
			 */

			if (replied ||

			    br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED))

				BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;

				BR_INPUT_SKB_CB(skb)->proxyarp_replied = 1;

		}



		neigh_release(n);
@@ -393,7 +393,7 @@ void br_do_suppress_nd(struct sk_buff *skb, struct net_bridge *br, 
	struct ipv6hdr *iphdr;

	struct neighbour *n;



	BR_INPUT_SKB_CB(skb)->proxyarp_replied = false;

	BR_INPUT_SKB_CB(skb)->proxyarp_replied = 0;



	if (p && (p->flags & BR_NEIGH_SUPPRESS))

		return;
@@ -401,7 +401,7 @@ void br_do_suppress_nd(struct sk_buff *skb, struct net_bridge *br, 
	if (msg->icmph.icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT &&

	    !msg->icmph.icmp6_solicited) {

		/* prevent flooding to neigh suppress ports */

		BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;

		BR_INPUT_SKB_CB(skb)->proxyarp_replied = 1;

		return;

	}
@@ -414,7 +414,7 @@ void br_do_suppress_nd(struct sk_buff *skb, struct net_bridge *br, 


	if (ipv6_addr_any(saddr) || !ipv6_addr_cmp(saddr, daddr)) {

		/* prevent flooding to neigh suppress ports */

		BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;

		BR_INPUT_SKB_CB(skb)->proxyarp_replied = 1;

		return;

	}
@@ -432,7 +432,7 @@ void br_do_suppress_nd(struct sk_buff *skb, struct net_bridge *br, 
		/* its our own ip, so don't proxy reply

		 * and don't forward to arp suppress ports

		 */

		BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;

		BR_INPUT_SKB_CB(skb)->proxyarp_replied = 1;

		return;

	}
@@ -465,7 +465,7 @@ void br_do_suppress_nd(struct sk_buff *skb, struct net_bridge *br, 
			 */

			if (replied ||

			    br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED))

				BR_INPUT_SKB_CB(skb)->proxyarp_replied = true;

				BR_INPUT_SKB_CB(skb)->proxyarp_replied = 1;

		}

		neigh_release(n);

	}

net/bridge/br_input.c

+2 −0
Original line number Diff line number Diff line
@@ -227,6 +227,8 @@ rx_handler_result_t br_handle_frame(struct sk_buff **pskb) 
	if (!skb)

		return RX_HANDLER_CONSUMED;



	memset(skb->cb, 0, sizeof(struct br_input_skb_cb));



	p = br_port_get_rcu(skb->dev);

	if (p->flags & BR_VLAN_TUNNEL) {

		if (br_handle_ingress_vlan_tunnel(skb, p,

net/bridge/br_private.h

+5 −7
Original line number Diff line number Diff line
@@ -425,15 +425,13 @@ struct br_input_skb_cb { 
	struct net_device *brdev;



#ifdef CONFIG_BRIDGE_IGMP_SNOOPING

	int igmp;

	int mrouters_only;

	u8 igmp;

	u8 mrouters_only:1;

#endif



	bool proxyarp_replied;

	bool src_port_isolated;



	u8 proxyarp_replied:1;

	u8 src_port_isolated:1;

#ifdef CONFIG_BRIDGE_VLAN_FILTERING

	bool vlan_filtered;

	u8 vlan_filtered:1;

#endif



#ifdef CONFIG_NET_SWITCHDEV

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