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netfilter: bridge: reduce nf_bridge_info to 32 bytes again

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We can use union for most of the temporary cruft (original ipv4/ipv6
address, source mac, physoutdev) since they're used during different
stages of br netfilter traversal.

Also get rid of the last two ->mask users.

Shrinks struct from 48 to 32 on 64bit arch.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Florian Westphal 2015-07-23 16:21:30 +02:00 committed by Pablo Neira Ayuso
parent d7ee351904
commit 72b1e5e4ca
6 changed files with 33 additions and 28 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

12
include/linux/netfilter_bridge.h
View file

@ -17,9 +17,6 @@ enum nf_br_hook_priorities {
#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
#define BRNF_BRIDGED_DNAT 0x02
#define BRNF_NF_BRIDGE_PREROUTING 0x08
int br_handle_frame_finish(struct sock *sk, struct sk_buff *skb);
static inline void br_drop_fake_rtable(struct sk_buff *skb)
@ -63,8 +60,17 @@ nf_bridge_get_physoutdev(const struct sk_buff *skb)
{
return skb->nf_bridge ? skb->nf_bridge->physoutdev : NULL;
}
static inline bool nf_bridge_in_prerouting(const struct sk_buff *skb)
{
return skb->nf_bridge && skb->nf_bridge->in_prerouting;
}
#else
#define br_drop_fake_rtable(skb) do { } while (0)
static inline bool nf_bridge_in_prerouting(const struct sk_buff *skb)
{
return false;
}
#endif /* CONFIG_BRIDGE_NETFILTER */
#endif

19
include/linux/skbuff.h
View file

@ -173,17 +173,24 @@ struct nf_bridge_info {
BRNF_PROTO_8021Q,
BRNF_PROTO_PPPOE
} orig_proto:8;
bool pkt_otherhost;
u8 pkt_otherhost:1;
u8 in_prerouting:1;
u8 bridged_dnat:1;
__u16 frag_max_size;
unsigned int mask;
struct net_device *physindev;
union {
struct net_device *physoutdev;
char neigh_header[8];
};
union {
/* prerouting: detect dnat in orig/reply direction */
__be32 ipv4_daddr;
struct in6_addr ipv6_daddr;
/* after prerouting + nat detected: store original source
* mac since neigh resolution overwrites it, only used while
* skb is out in neigh layer.
*/
char neigh_header[8];
/* always valid & non-NULL from FORWARD on, for physdev match */
struct net_device *physoutdev;
};
};
#endif

14
net/bridge/br_netfilter_hooks.c
View file

@ -284,7 +284,7 @@ int br_nf_pre_routing_finish_bridge(struct sock *sk, struct sk_buff *skb)
nf_bridge->neigh_header,
ETH_HLEN-ETH_ALEN);
/* tell br_dev_xmit to continue with forwarding */
nf_bridge->mask |= BRNF_BRIDGED_DNAT;
nf_bridge->bridged_dnat = 1;
/* FIXME Need to refragment */
ret = neigh->output(neigh, skb);
}
@ -356,7 +356,7 @@ static int br_nf_pre_routing_finish(struct sock *sk, struct sk_buff *skb)
skb->pkt_type = PACKET_OTHERHOST;
nf_bridge->pkt_otherhost = false;
}
nf_bridge->mask &= ~BRNF_NF_BRIDGE_PREROUTING;
nf_bridge->in_prerouting = 0;
if (br_nf_ipv4_daddr_was_changed(skb, nf_bridge)) {
if ((err = ip_route_input(skb, iph->daddr, iph->saddr, iph->tos, dev))) {
struct in_device *in_dev = __in_dev_get_rcu(dev);
@ -444,7 +444,7 @@ struct net_device *setup_pre_routing(struct sk_buff *skb)
nf_bridge->pkt_otherhost = true;
}
nf_bridge->mask |= BRNF_NF_BRIDGE_PREROUTING;
nf_bridge->in_prerouting = 1;
nf_bridge->physindev = skb->dev;
skb->dev = brnf_get_logical_dev(skb, skb->dev);
@ -850,10 +850,8 @@ static unsigned int ip_sabotage_in(const struct nf_hook_ops *ops,
struct sk_buff *skb,
const struct nf_hook_state *state)
{
if (skb->nf_bridge &&
!(skb->nf_bridge->mask & BRNF_NF_BRIDGE_PREROUTING)) {
if (skb->nf_bridge && !skb->nf_bridge->in_prerouting)
return NF_STOP;
}
return NF_ACCEPT;
}
@ -872,7 +870,7 @@ static void br_nf_pre_routing_finish_bridge_slow(struct sk_buff *skb)
struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
skb_pull(skb, ETH_HLEN);
nf_bridge->mask &= ~BRNF_BRIDGED_DNAT;
nf_bridge->bridged_dnat = 0;
BUILD_BUG_ON(sizeof(nf_bridge->neigh_header) != (ETH_HLEN - ETH_ALEN));
@ -887,7 +885,7 @@ static void br_nf_pre_routing_finish_bridge_slow(struct sk_buff *skb)
static int br_nf_dev_xmit(struct sk_buff *skb)
{
if (skb->nf_bridge && (skb->nf_bridge->mask & BRNF_BRIDGED_DNAT)) {
if (skb->nf_bridge && skb->nf_bridge->bridged_dnat) {
br_nf_pre_routing_finish_bridge_slow(skb);
return 1;
}

2
net/bridge/br_netfilter_ipv6.c
View file

@ -174,7 +174,7 @@ static int br_nf_pre_routing_finish_ipv6(struct sock *sk, struct sk_buff *skb)
skb->pkt_type = PACKET_OTHERHOST;
nf_bridge->pkt_otherhost = false;
}
nf_bridge->mask &= ~BRNF_NF_BRIDGE_PREROUTING;
nf_bridge->in_prerouting = 0;
if (br_nf_ipv6_daddr_was_changed(skb, nf_bridge)) {
skb_dst_drop(skb);
v6ops->route_input(skb);

7
net/ipv4/netfilter/nf_defrag_ipv4.c
View file

@ -49,12 +49,9 @@ static enum ip_defrag_users nf_ct_defrag_user(unsigned int hooknum,
if (skb->nfct)
zone = nf_ct_zone((struct nf_conn *)skb->nfct);
#endif
#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
if (skb->nf_bridge &&
skb->nf_bridge->mask & BRNF_NF_BRIDGE_PREROUTING)
if (nf_bridge_in_prerouting(skb))
return IP_DEFRAG_CONNTRACK_BRIDGE_IN + zone;
#endif
if (hooknum == NF_INET_PRE_ROUTING)
return IP_DEFRAG_CONNTRACK_IN + zone;
else

7
net/ipv6/netfilter/nf_defrag_ipv6_hooks.c
View file

@ -39,12 +39,9 @@ static enum ip6_defrag_users nf_ct6_defrag_user(unsigned int hooknum,
if (skb->nfct)
zone = nf_ct_zone((struct nf_conn *)skb->nfct);
#endif
#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
if (skb->nf_bridge &&
skb->nf_bridge->mask & BRNF_NF_BRIDGE_PREROUTING)
if (nf_bridge_in_prerouting(skb))
return IP6_DEFRAG_CONNTRACK_BRIDGE_IN + zone;
#endif
if (hooknum == NF_INET_PRE_ROUTING)
return IP6_DEFRAG_CONNTRACK_IN + zone;
else