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--- a/include/linux/netfilter_ipv4/ip_tables.h
+++ b/include/linux/netfilter_ipv4/ip_tables.h
@@ -62,6 +62,7 @@ struct ipt_ip {
#define IPT_F_FRAG 0x01 /* Set if rule is a fragment rule */
#define IPT_F_GOTO 0x02 /* Set if jump is a goto */
#define IPT_F_MASK 0x03 /* All possible flag bits mask. */
+#define IPT_F_NO_DEF_MATCH 0x80 /* Internal: no default match rules present */
/* Values for "inv" field in struct ipt_ip. */
#define IPT_INV_VIA_IN 0x01 /* Invert the sense of IN IFACE. */
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -88,6 +88,9 @@ ip_packet_match(const struct iphdr *ip,
#define FWINV(bool, invflg) ((bool) ^ !!(ipinfo->invflags & (invflg)))
+ if (ipinfo->flags & IPT_F_NO_DEF_MATCH)
+ return true;
+
if (FWINV((ip->saddr&ipinfo->smsk.s_addr) != ipinfo->src.s_addr,
IPT_INV_SRCIP)
|| FWINV((ip->daddr&ipinfo->dmsk.s_addr) != ipinfo->dst.s_addr,
@@ -151,13 +154,35 @@ ip_packet_match(const struct iphdr *ip,
return false;
}
+#undef FWINV
return true;
}
static bool
-ip_checkentry(const struct ipt_ip *ip)
+ip_checkentry(struct ipt_ip *ip)
{
- if (ip->flags & ~IPT_F_MASK) {
+#define FWINV(bool, invflg) ((bool) || (ip->invflags & (invflg)))
+
+ if (FWINV(ip->smsk.s_addr, IPT_INV_SRCIP) ||
+ FWINV(ip->dmsk.s_addr, IPT_INV_DSTIP))
+ goto has_match_rules;
+
+ if (FWINV(!!((const unsigned long *)ip->iniface_mask)[0],
+ IPT_INV_VIA_IN) ||
+ FWINV(!!((const unsigned long *)ip->outiface_mask)[0],
+ IPT_INV_VIA_OUT))
+ goto has_match_rules;
+
+ if (FWINV(ip->proto, IPT_INV_PROTO))
+ goto has_match_rules;
+
+ if (FWINV(ip->flags&IPT_F_FRAG, IPT_INV_FRAG))
+ goto has_match_rules;
+
+ ip->flags |= IPT_F_NO_DEF_MATCH;
+
+has_match_rules:
+ if (ip->flags & ~(IPT_F_MASK|IPT_F_NO_DEF_MATCH)) {
duprintf("Unknown flag bits set: %08X\n",
ip->flags & ~IPT_F_MASK);
return false;
@@ -167,6 +192,8 @@ ip_checkentry(const struct ipt_ip *ip)
ip->invflags & ~IPT_INV_MASK);
return false;
}
+
+#undef FWINV
return true;
}
@@ -214,7 +241,6 @@ unconditional(const struct ipt_ip *ip)
return 0;
return 1;
-#undef FWINV
}
#if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
@@ -332,8 +358,27 @@ ipt_do_table(struct sk_buff *skb,
struct xt_match_param mtpar;
struct xt_target_param tgpar;
- /* Initialization */
ip = ip_hdr(skb);
+
+ read_lock_bh(&table->lock);
+ IP_NF_ASSERT(table->valid_hooks & (1 << hook));
+ private = table->private;
+ table_base = (void *)private->entries[smp_processor_id()];
+ e = get_entry(table_base, private->hook_entry[hook]);
+ if (e->target_offset <= sizeof(struct ipt_entry) &&
+ (e->ip.flags & IPT_F_NO_DEF_MATCH)) {
+ struct ipt_entry_target *t = ipt_get_target(e);
+ if (!t->u.kernel.target->target) {
+ int v = ((struct ipt_standard_target *)t)->verdict;
+ if ((v < 0) && (v != IPT_RETURN)) {
+ ADD_COUNTER(e->counters, ntohs(ip->tot_len), 1);
+ read_unlock_bh(&table->lock);
+ return (unsigned)(-v) - 1;
+ }
+ }
+ }
+
+ /* Initialization */
datalen = skb->len - ip->ihl * 4;
indev = in ? in->name : nulldevname;
outdev = out ? out->name : nulldevname;
@@ -351,12 +396,6 @@ ipt_do_table(struct sk_buff *skb,
mtpar.family = tgpar.family = NFPROTO_IPV4;
tgpar.hooknum = hook;
- read_lock_bh(&table->lock);
- IP_NF_ASSERT(table->valid_hooks & (1 << hook));
- private = table->private;
- table_base = (void *)private->entries[smp_processor_id()];
- e = get_entry(table_base, private->hook_entry[hook]);
-
/* For return from builtin chain */
back = get_entry(table_base, private->underflow[hook]);
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