@@ -16,14 +16,18 @@
static spinlock_t nf_connlabels_lock;
-static void replace_u32(u32 *address, u32 mask, u32 new)
+static int replace_u32(u32 *address, u32 mask, u32 new)
{
u32 old, tmp;
do {
old = *address;
tmp = (old & mask) ^ new;
+ if (old == tmp)
+ return 0;
} while (cmpxchg(address, old, tmp) != old);
+
+ return 1;
}
int nf_connlabels_replace(struct nf_conn *ct,
@@ -32,6 +36,7 @@ int nf_connlabels_replace(struct nf_conn *ct,
{
struct nf_conn_labels *labels;
unsigned int size, i;
+ int changed = 0;
u32 *dst;
labels = nf_ct_labels_find(ct);
@@ -43,16 +48,15 @@ int nf_connlabels_replace(struct nf_conn *ct,
words32 = size / sizeof(u32);
dst = (u32 *) labels->bits;
- if (words32) {
- for (i = 0; i < words32; i++)
- replace_u32(&dst[i], mask ? ~mask[i] : 0, data[i]);
- }
+ for (i = 0; i < words32; i++)
+ changed |= replace_u32(&dst[i], mask ? ~mask[i] : 0, data[i]);
size /= sizeof(u32);
for (i = words32; i < size; i++) /* pad */
replace_u32(&dst[i], 0, 0);
- nf_conntrack_event_cache(IPCT_LABEL, ct);
+ if (changed)
+ nf_conntrack_event_cache(IPCT_LABEL, ct);
return 0;
}
EXPORT_SYMBOL_GPL(nf_connlabels_replace);
make the replace function only send a ctnetlink event if the contents of the new set is different. Otherwise 'ct label set ct label | bar' will cause netlink event storm since we "replace" labels for each packet. Signed-off-by: Florian Westphal <fw@strlen.de> --- net/netfilter/nf_conntrack_labels.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-)