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--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -310,6 +310,33 @@ struct ipt_entry *ipt_next_entry(const s
return (void *)entry + entry->next_offset;
}
+static bool
+ipt_handle_default_rule(struct ipt_entry *e, unsigned int *verdict)
+{
+ struct xt_entry_target *t;
+ struct xt_standard_target *st;
+
+ if (e->target_offset != sizeof(struct ipt_entry))
+ return false;
+
+ if (!(e->ip.flags & IPT_F_NO_DEF_MATCH))
+ return false;
+
+ t = ipt_get_target(e);
+ if (t->u.kernel.target->target)
+ return false;
+
+ st = (struct xt_standard_target *) t;
+ if (st->verdict == XT_RETURN)
+ return false;
+
+ if (st->verdict >= 0)
+ return false;
+
+ *verdict = (unsigned)(-st->verdict) - 1;
+ return true;
+}
+
/* Returns one of the generic firewall policies, like NF_ACCEPT. */
unsigned int
ipt_do_table(struct sk_buff *skb,
@@ -334,19 +361,6 @@ ipt_do_table(struct sk_buff *skb,
ip = ip_hdr(skb);
indev = in ? in->name : nulldevname;
outdev = out ? out->name : nulldevname;
- /* We handle fragments by dealing with the first fragment as
- * if it was a normal packet. All other fragments are treated
- * normally, except that they will NEVER match rules that ask
- * things we don't know, ie. tcp syn flag or ports). If the
- * rule is also a fragment-specific rule, non-fragments won't
- * match it. */
- acpar.fragoff = ntohs(ip->frag_off) & IP_OFFSET;
- acpar.thoff = ip_hdrlen(skb);
- acpar.hotdrop = false;
- acpar.in = in;
- acpar.out = out;
- acpar.family = NFPROTO_IPV4;
- acpar.hooknum = hook;
IP_NF_ASSERT(table->valid_hooks & (1 << hook));
local_bh_disable();
@@ -364,6 +378,26 @@ ipt_do_table(struct sk_buff *skb,
origptr = *stackptr;
e = get_entry(table_base, private->hook_entry[hook]);
+ if (ipt_handle_default_rule(e, &verdict)) {
+ ADD_COUNTER(e->counters, skb->len, 1);
+ xt_write_recseq_end(addend);
+ local_bh_enable();
+ return verdict;
+ }
+
+ /* We handle fragments by dealing with the first fragment as
+ * if it was a normal packet. All other fragments are treated
+ * normally, except that they will NEVER match rules that ask
+ * things we don't know, ie. tcp syn flag or ports). If the
+ * rule is also a fragment-specific rule, non-fragments won't
+ * match it. */
+ acpar.fragoff = ntohs(ip->frag_off) & IP_OFFSET;
+ acpar.thoff = ip_hdrlen(skb);
+ acpar.hotdrop = false;
+ acpar.in = in;
+ acpar.out = out;
+ acpar.family = NFPROTO_IPV4;
+ acpar.hooknum = hook;
pr_debug("Entering %s(hook %u); sp at %u (UF %p)\n",
table->name, hook, origptr,
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