udp: add encap_destroy callback
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>
diff --git a/include/linux/udp.h b/include/linux/udp.h
index 9d81de1..42278bb 100644
--- a/include/linux/udp.h
+++ b/include/linux/udp.h
@@ -68,6 +68,7 @@
* 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)
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 265c42c..0a073a2 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1762,9 +1762,16 @@
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);
+ }
}
/*
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 599e1ba6..d8e5e85 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -1285,10 +1285,18 @@
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);
}