ipv6: introduce a hash table to store dst cache
Add a hash table into struct rt6_info in order to store dst caches
created by pmtu discovery and ip redirect in ipv6 routing code.
APIs to add dst cache, delete dst cache, find dst cache and update
dst cache in the hash table are implemented and will be used in later
commits.
This is a preparation work to move all cache routes into the exception
table instead of getting inserted into the fib6 tree.
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index 152b7b1..c4864c1 100644
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -98,6 +98,22 @@ struct rt6key {
struct fib6_table;
+struct rt6_exception_bucket {
+ struct hlist_head chain;
+ int depth;
+};
+
+struct rt6_exception {
+ struct hlist_node hlist;
+ struct rt6_info *rt6i;
+ unsigned long stamp;
+ struct rcu_head rcu;
+};
+
+#define FIB6_EXCEPTION_BUCKET_SIZE_SHIFT 10
+#define FIB6_EXCEPTION_BUCKET_SIZE (1 << FIB6_EXCEPTION_BUCKET_SIZE_SHIFT)
+#define FIB6_MAX_DEPTH 5
+
struct rt6_info {
struct dst_entry dst;
@@ -134,12 +150,15 @@ struct rt6_info {
struct inet6_dev *rt6i_idev;
struct rt6_info * __percpu *rt6i_pcpu;
+ struct rt6_exception_bucket __rcu *rt6i_exception_bucket;
u32 rt6i_metric;
u32 rt6i_pmtu;
/* more non-fragment space at head required */
unsigned short rt6i_nfheader_len;
u8 rt6i_protocol;
+ u8 exception_bucket_flushed:1,
+ unused:7;
};
static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst)