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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,
@@ -147,13 +150,32 @@ 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->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;
@@ -163,6 +185,8 @@ ip_checkentry(const struct ipt_ip *ip)
ip->invflags & ~IPT_INV_MASK);
return false;
}
+
+#undef FWINV
return true;
}
@@ -210,7 +234,6 @@ unconditional(const struct ipt_ip *ip)
return 0;
return 1;
-#undef FWINV
}
#if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
|
