mpls: reduce memory usage of routes

[cascardo/linux.git] / net / mpls / internal.h

diff --git a/net/mpls/internal.h b/net/mpls/internal.h
index d7757be..bde52ce 100644 (file)
--- a/net/mpls/internal.h
+++ b/net/mpls/internal.h
@@ -25,7 +25,8 @@ struct sk_buff;
 #define MAX_NEW_LABELS 2
 
 /* This maximum ha length copied from the definition of struct neighbour */
-#define MAX_VIA_ALEN (ALIGN(MAX_ADDR_LEN, sizeof(unsigned long)))
+#define VIA_ALEN_ALIGN sizeof(unsigned long)
+#define MAX_VIA_ALEN (ALIGN(MAX_ADDR_LEN, VIA_ALEN_ALIGN))
 
 enum mpls_payload_type {
        MPT_UNSPEC, /* IPv4 or IPv6 */
@@ -44,14 +45,35 @@ struct mpls_nh { /* next hop label forwarding entry */
        u8                      nh_labels;
        u8                      nh_via_alen;
        u8                      nh_via_table;
-       u8                      nh_via[MAX_VIA_ALEN];
 };
 
+/* The route, nexthops and vias are stored together in the same memory
+ * block:
+ *
+ * +----------------------+
+ * | mpls_route           |
+ * +----------------------+
+ * | mpls_nh 0            |
+ * +----------------------+
+ * | ...                  |
+ * +----------------------+
+ * | mpls_nh n-1          |
+ * +----------------------+
+ * | alignment padding    |
+ * +----------------------+
+ * | via[rt_max_alen] 0   |
+ * +----------------------+
+ * | ...                  |
+ * +----------------------+
+ * | via[rt_max_alen] n-1 |
+ * +----------------------+
+ */
 struct mpls_route { /* next hop label forwarding entry */
        struct rcu_head         rt_rcu;
        u8                      rt_protocol;
        u8                      rt_payload_type;
-       int                     rt_nhn;
+       u8                      rt_max_alen;
+       unsigned int            rt_nhn;
        struct mpls_nh          rt_nh[0];
 };