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--- a/include/uapi/linux/netfilter_ipv4/ip_tables.h
+++ b/include/uapi/linux/netfilter_ipv4/ip_tables.h
@@ -87,6 +87,7 @@ 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
@@ -82,6 +82,9 @@ 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,
@@ -135,6 +138,29 @@ ip_packet_match(const struct iphdr *ip,
return true;
}
+static void
+ip_checkdefault(struct ipt_ip *ip)
+{
+ static const char iface_mask[IFNAMSIZ] = {};
+
+ if (ip->invflags || ip->flags & IPT_F_FRAG)
+ return;
+
+ if (memcmp(ip->iniface_mask, iface_mask, IFNAMSIZ) != 0)
+ return;
+
+ if (memcmp(ip->outiface_mask, iface_mask, IFNAMSIZ) != 0)
+ return;
+
+ if (ip->smsk.s_addr || ip->dmsk.s_addr)
+ return;
+
+ if (ip->proto)
+ return;
+
+ ip->flags |= IPT_F_NO_DEF_MATCH;
+}
+
static bool
ip_checkentry(const struct ipt_ip *ip)
{
@@ -649,6 +675,8 @@ find_check_entry(struct ipt_entry *e, st
struct xt_mtchk_param mtpar;
struct xt_entry_match *ematch;
+ ip_checkdefault(&e->ip);
+
j = 0;
mtpar.net = net;
mtpar.table = name;
@@ -941,6 +969,7 @@ copy_entries_to_user(unsigned int total_
const struct xt_table_info *private = table->private;
int ret = 0;
const void *loc_cpu_entry;
+ u8 flags;
counters = alloc_counters(table);
if (IS_ERR(counters))
@@ -971,6 +1000,14 @@ copy_entries_to_user(unsigned int total_
ret = -EFAULT;
goto free_counters;
}
+
+ flags = e->ip.flags & IPT_F_MASK;
+ if (copy_to_user(userptr + off
+ + offsetof(struct ipt_entry, ip.flags),
+ &flags, sizeof(flags)) != 0) {
+ ret = -EFAULT;
+ goto free_counters;
+ }
for (i = sizeof(struct ipt_entry);
i < e->target_offset;
|
