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bridge: reduce size of input cb to 16 bytes

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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: Florian Westphal <fw@strlen.de>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Florian Westphal 2019-04-11 16:36:40 +02:00 committed by Pablo Neira Ayuso
parent 26f7fe4a5d
commit f12064d1b4
3 changed files with 16 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
net/bridge/br_arp_nd_proxy.c
View File

@ -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);
}

2
net/bridge/br_input.c
View File

@ -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,

12
net/bridge/br_private.h
View File

@ -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