ipv6: allow to cache dst for a connected sk in ip6_sk_dst_lookup_flow()
Add 'connected' parameter to ip6_sk_dst_lookup_flow() and update
the cache only if ip6_sk_dst_check() returns NULL and a socket
is connected.
The function is used as before, the new behavior for UDP sockets
in udpv6_sendmsg() will be enabled in the next patch.
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index e6eaa4d..66a768b 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1105,23 +1105,32 @@ EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow);
* @sk: socket which provides the dst cache and route info
* @fl6: flow to lookup
* @final_dst: final destination address for ipsec lookup
+ * @connected: whether @sk is connected or not
*
* This function performs a route lookup on the given flow with the
* possibility of using the cached route in the socket if it is valid.
* It will take the socket dst lock when operating on the dst cache.
* As a result, this function can only be used in process context.
*
+ * In addition, for a connected socket, cache the dst in the socket
+ * if the current cache is not valid.
+ *
* It returns a valid dst pointer on success, or a pointer encoded
* error code.
*/
struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6,
- const struct in6_addr *final_dst)
+ const struct in6_addr *final_dst,
+ bool connected)
{
struct dst_entry *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie);
dst = ip6_sk_dst_check(sk, dst, fl6);
- if (!dst)
- dst = ip6_dst_lookup_flow(sk, fl6, final_dst);
+ if (dst)
+ return dst;
+
+ dst = ip6_dst_lookup_flow(sk, fl6, final_dst);
+ if (connected && !IS_ERR(dst))
+ ip6_sk_dst_store_flow(sk, dst_clone(dst), fl6);
return dst;
}
