[NETFILTER]: nf_conntrack: add helper function for expectation initialization

Expectation address masks need to be differently initialized depending
on the address family, create helper function to avoid cluttering up
the code too much.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/netfilter/nf_conntrack_expect.h

@@ -68,6 +68,10 @@ void nf_conntrack_unexpect_related(struct nf_conntrack_expect *exp);
 /* Allocate space for an expectation: this is mandatory before calling
    nf_conntrack_expect_related.  You will have to call put afterwards. */
 struct nf_conntrack_expect *nf_conntrack_expect_alloc(struct nf_conn *me);
+void nf_conntrack_expect_init(struct nf_conntrack_expect *, int,
+			      union nf_conntrack_address *,
+			      union nf_conntrack_address *,
+			      u_int8_t, __be16 *, __be16 *);
 void nf_conntrack_expect_put(struct nf_conntrack_expect *exp);
 int nf_conntrack_expect_related(struct nf_conntrack_expect *expect);
 

include/net/netfilter/nf_conntrack_tuple.h

@@ -24,7 +24,7 @@
 
 /* The l3 protocol-specific manipulable parts of the tuple: always in
    network order! */
-union nf_conntrack_man_l3proto {
+union nf_conntrack_address {
 	u_int32_t all[NF_CT_TUPLE_L3SIZE];
 	__be32 ip;
 	__be32 ip6[4];
@@ -54,7 +54,7 @@ union nf_conntrack_man_proto
 /* The manipulable part of the tuple. */
 struct nf_conntrack_man
 {
-	union nf_conntrack_man_l3proto u3;
+	union nf_conntrack_address u3;
 	union nf_conntrack_man_proto u;
 	/* Layer 3 protocol */
 	u_int16_t l3num;
@@ -67,11 +67,7 @@ struct nf_conntrack_tuple
 
 	/* These are the parts of the tuple which are fixed. */
 	struct {
-		union {
-			u_int32_t all[NF_CT_TUPLE_L3SIZE];
-			u_int32_t ip;
-			u_int32_t ip6[4];
-		} u3;
+		union nf_conntrack_address u3;
 		union {
 			/* Add other protocols here. */
 			u_int16_t all;

net/netfilter/nf_conntrack_expect.c

@@ -196,6 +196,74 @@ struct nf_conntrack_expect *nf_conntrack_expect_alloc(struct nf_conn *me)
 	return new;
 }
 
+void nf_conntrack_expect_init(struct nf_conntrack_expect *exp, int family,
+			      union nf_conntrack_address *saddr,
+			      union nf_conntrack_address *daddr,
+			      u_int8_t proto, __be16 *src, __be16 *dst)
+{
+	int len;
+
+	if (family == AF_INET)
+		len = 4;
+	else
+		len = 16;
+
+	exp->flags = 0;
+	exp->expectfn = NULL;
+	exp->helper = NULL;
+	exp->tuple.src.l3num = family;
+	exp->tuple.dst.protonum = proto;
+	exp->mask.src.l3num = 0xFFFF;
+	exp->mask.dst.protonum = 0xFF;
+
+	if (saddr) {
+		memcpy(&exp->tuple.src.u3, saddr, len);
+		if (sizeof(exp->tuple.src.u3) > len)
+			/* address needs to be cleared for nf_ct_tuple_equal */
+			memset((void *)&exp->tuple.src.u3 + len, 0x00,
+			       sizeof(exp->tuple.src.u3) - len);
+		memset(&exp->mask.src.u3, 0xFF, len);
+		if (sizeof(exp->mask.src.u3) > len)
+			memset((void *)&exp->mask.src.u3 + len, 0x00,
+			       sizeof(exp->mask.src.u3) - len);
+	} else {
+		memset(&exp->tuple.src.u3, 0x00, sizeof(exp->tuple.src.u3));
+		memset(&exp->mask.src.u3, 0x00, sizeof(exp->mask.src.u3));
+	}
+
+	if (daddr) {
+		memcpy(&exp->tuple.dst.u3, daddr, len);
+		if (sizeof(exp->tuple.dst.u3) > len)
+			/* address needs to be cleared for nf_ct_tuple_equal */
+			memset((void *)&exp->tuple.dst.u3 + len, 0x00,
+			       sizeof(exp->tuple.dst.u3) - len);
+		memset(&exp->mask.dst.u3, 0xFF, len);
+		if (sizeof(exp->mask.dst.u3) > len)
+			memset((void *)&exp->mask.dst.u3 + len, 0x00,
+			       sizeof(exp->mask.dst.u3) - len);
+	} else {
+		memset(&exp->tuple.dst.u3, 0x00, sizeof(exp->tuple.dst.u3));
+		memset(&exp->mask.dst.u3, 0x00, sizeof(exp->mask.dst.u3));
+	}
+
+	if (src) {
+		exp->tuple.src.u.all = (__force u16)*src;
+		exp->mask.src.u.all = 0xFFFF;
+	} else {
+		exp->tuple.src.u.all = 0;
+		exp->mask.src.u.all = 0;
+	}
+
+	if (dst) {
+		exp->tuple.dst.u.all = (__force u16)*dst;
+		exp->mask.dst.u.all = 0xFFFF;
+	} else {
+		exp->tuple.dst.u.all = 0;
+		exp->mask.dst.u.all = 0;
+	}
+}
+EXPORT_SYMBOL_GPL(nf_conntrack_expect_init);
+
 void nf_conntrack_expect_put(struct nf_conntrack_expect *exp)
 {
 	if (atomic_dec_and_test(&exp->use))