netfilter: nf_nat: better error handling of nf_ct_expect_related() in helpers
This patch improves the situation in which the expectation table is
full for conntrack NAT helpers. Basically, we give up if we don't
find a place in the table instead of looping over nf_ct_expect_related()
with a different port (we should only do this if it returns -EBUSY, for
-EMFILE or -ESHUTDOWN I think that it's better to skip this).
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/net/ipv4/netfilter/nf_nat_amanda.c b/net/ipv4/netfilter/nf_nat_amanda.c
index c31b876..0f23b3f 100644
--- a/net/ipv4/netfilter/nf_nat_amanda.c
+++ b/net/ipv4/netfilter/nf_nat_amanda.c
@@ -44,9 +44,16 @@
/* Try to get same port: if not, try to change it. */
for (port = ntohs(exp->saved_proto.tcp.port); port != 0; port++) {
+ int ret;
+
exp->tuple.dst.u.tcp.port = htons(port);
- if (nf_ct_expect_related(exp) == 0)
+ ret = nf_ct_expect_related(exp);
+ if (ret == 0)
break;
+ else if (ret != -EBUSY) {
+ port = 0;
+ break;
+ }
}
if (port == 0)