udp: add encap_destroy callback (44046a59) · Commits · 戴 / test

Users of udp encapsulation currently have an encap_rcv callback which they can use to hook into the udp receive path. In situations where a encapsulation user allocates resources associated with a udp encap socket, it may be convenient to be able to also hook the proto .destroy operation. For example, if an encap user holds a reference to the udp socket, the destroy hook might be used to relinquish this reference. This patch adds a socket destroy hook into udp, which is set and enabled in the same way as the existing encap_rcv hook. Signed-off-by:

Tom Parkin <tparkin@katalix.com> Signed-off-by:

James Chapman <jchapman@katalix.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

include/linux/udp.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -68,6 +68,7 @@ struct udp_sock {
		* For encapsulation sockets.
		*/
		int (encap_rcv)(struct sock sk, struct sk_buff *skb);
		void (encap_destroy)(struct sock sk);
		};

		static inline struct udp_sock udp_sk(const struct sock sk)

net/ipv4/udp.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -1762,9 +1762,16 @@ int udp_rcv(struct sk_buff *skb)

		void udp_destroy_sock(struct sock *sk)
		{
		struct udp_sock *up = udp_sk(sk);
		bool slow = lock_sock_fast(sk);
		udp_flush_pending_frames(sk);
		unlock_sock_fast(sk, slow);
		if (static_key_false(&udp_encap_needed) && up->encap_type) {
		void (encap_destroy)(struct sock sk);
		encap_destroy = ACCESS_ONCE(up->encap_destroy);
		if (encap_destroy)
		encap_destroy(sk);
		}
		}

		/*

net/ipv6/udp.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -1285,10 +1285,18 @@ do_confirm:

		void udpv6_destroy_sock(struct sock *sk)
		{
		struct udp_sock *up = udp_sk(sk);
		lock_sock(sk);
		udp_v6_flush_pending_frames(sk);
		release_sock(sk);

		if (static_key_false(&udpv6_encap_needed) && up->encap_type) {
		void (encap_destroy)(struct sock sk);
		encap_destroy = ACCESS_ONCE(up->encap_destroy);
		if (encap_destroy)
		encap_destroy(sk);
		}

		inet6_destroy_sock(sk);
		}

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