From patchwork Fri Feb 15 10:25:14 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [RFC,1/6] udp: add encap_destroy callback From: Tom Parkin X-Patchwork-Id: 220713 Message-Id: <1360923919-7203-2-git-send-email-tparkin@katalix.com> To: netdev@vger.kernel.org Cc: jchapman@katalix.com, celston@katalix.com, Tom Parkin Date: Fri, 15 Feb 2013 10:25:14 +0000 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. --- include/linux/udp.h | 1 + net/ipv4/udp.c | 7 +++++++ net/ipv6/udp.c | 8 ++++++++ 3 files changed, 16 insertions(+) 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 @@ 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) diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 6791aac..48e2366 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -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); + } } /* 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 @@ 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); }