bpf, dst: add and use dst_tclassid helper

borkmann · davem330 · commit 808c1b697c3c · 2016-03-18T19:38:46.000-04:00
We can just add a small helper dst_tclassid() for retrieving the
dst-&gt;tclassid value. It makes the code a bit better in that we can
get rid of the ifdef from filter.c by moving this into the header.

Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
diff --git a/include/net/dst.h b/include/net/dst.h
@@ -398,6 +398,18 @@ static inline void skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev,
 	__skb_tunnel_rx(skb, dev, net);
 }
 
+static inline u32 dst_tclassid(const struct sk_buff *skb)
+{
+#ifdef CONFIG_IP_ROUTE_CLASSID
+	const struct dst_entry *dst;
+
+	dst = skb_dst(skb);
+	if (dst)
+		return dst->tclassid;
+#endif
+	return 0;
+}
+
 int dst_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb);
 static inline int dst_discard(struct sk_buff *skb)
 {
diff --git a/net/core/filter.c b/net/core/filter.c
@@ -1682,14 +1682,7 @@ static const struct bpf_func_proto bpf_get_cgroup_classid_proto = {
 
 static u64 bpf_get_route_realm(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
 {
-#ifdef CONFIG_IP_ROUTE_CLASSID
-	const struct dst_entry *dst;
-
-	dst = skb_dst((struct sk_buff *) (unsigned long) r1);
-	if (dst)
-		return dst->tclassid;
-#endif
-	return 0;
+	return dst_tclassid((struct sk_buff *) (unsigned long) r1);
 }
 
 static const struct bpf_func_proto bpf_get_route_realm_proto = {

Original file line number	Diff line number	Diff line change
`@@ -1682,14 +1682,7 @@ static const struct bpf_func_proto bpf_get_cgroup_classid_proto = {`
`1682`	`1682`
`1683`	`1683`	`static u64 bpf_get_route_realm(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)`
`1684`	`1684`	`{`
`1685`		`-#ifdef CONFIG_IP_ROUTE_CLASSID`
`1686`		`- const struct dst_entry *dst;`
`1687`		`-`
`1688`		`- dst = skb_dst((struct sk_buff *) (unsigned long) r1);`
`1689`		`- if (dst)`
`1690`		`- return dst->tclassid;`
`1691`		`-#endif`
`1692`		`- return 0;`
	`1685`	`+ return dst_tclassid((struct sk_buff *) (unsigned long) r1);`
`1693`	`1686`	`}`
`1694`	`1687`
`1695`	`1688`	`static const struct bpf_func_proto bpf_get_route_realm_proto = {`