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[NETFILTER]: ctnetlink: avoid unneccessary event message generation

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Avoid unneccessary event message generation by checking for netlink
listeners before building a message.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Patrick McHardy
2006-03-20 18:03:59 -08:00
committed by David S. Miller
parent c4b8851392
commit a242769248
4 changed files with 15 additions and 6 deletions
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1
include/linux/netfilter/nfnetlink.h
View File

@@ -164,6 +164,7 @@ extern void nfattr_parse(struct nfattr *tb[], int maxattr,
__res; \ __res; \
}) })
extern int nfnetlink_has_listeners(unsigned int group);
extern int nfnetlink_send(struct sk_buff *skb, u32 pid, unsigned group, extern int nfnetlink_send(struct sk_buff *skb, u32 pid, unsigned group,
int echo); int echo);
extern int nfnetlink_unicast(struct sk_buff *skb, u_int32_t pid, int flags); extern int nfnetlink_unicast(struct sk_buff *skb, u_int32_t pid, int flags);

7
net/ipv4/netfilter/ip_conntrack_netlink.c
View File

@@ -327,9 +327,10 @@ static int ctnetlink_conntrack_event(struct notifier_block *this,
group = NFNLGRP_CONNTRACK_UPDATE; group = NFNLGRP_CONNTRACK_UPDATE;
} else } else
return NOTIFY_DONE; return NOTIFY_DONE;
/* FIXME: Check if there are any listeners before, don't hurt performance */ if (!nfnetlink_has_listeners(group))
return NOTIFY_DONE;
skb = alloc_skb(NLMSG_GOODSIZE, GFP_ATOMIC); skb = alloc_skb(NLMSG_GOODSIZE, GFP_ATOMIC);
if (!skb) if (!skb)
return NOTIFY_DONE; return NOTIFY_DONE;

7
net/netfilter/nf_conntrack_netlink.c
View File

@@ -338,9 +338,10 @@ static int ctnetlink_conntrack_event(struct notifier_block *this,
group = NFNLGRP_CONNTRACK_UPDATE; group = NFNLGRP_CONNTRACK_UPDATE;
} else } else
return NOTIFY_DONE; return NOTIFY_DONE;
/* FIXME: Check if there are any listeners before, don't hurt performance */ if (!nfnetlink_has_listeners(group))
return NOTIFY_DONE;
skb = alloc_skb(NLMSG_GOODSIZE, GFP_ATOMIC); skb = alloc_skb(NLMSG_GOODSIZE, GFP_ATOMIC);
if (!skb) if (!skb)
return NOTIFY_DONE; return NOTIFY_DONE;

6
net/netfilter/nfnetlink.c
View File

@@ -191,6 +191,12 @@ nfnetlink_check_attributes(struct nfnetlink_subsystem *subsys,
return 0; return 0;
} }
int nfnetlink_has_listeners(unsigned int group)
{
return netlink_has_listeners(nfnl, group);
}
EXPORT_SYMBOL_GPL(nfnetlink_has_listeners);
int nfnetlink_send(struct sk_buff *skb, u32 pid, unsigned group, int echo) int nfnetlink_send(struct sk_buff *skb, u32 pid, unsigned group, int echo)
{ {
gfp_t allocation = in_interrupt() ? GFP_ATOMIC : GFP_KERNEL; gfp_t allocation = in_interrupt() ? GFP_ATOMIC : GFP_KERNEL;