From patchwork Tue Jul 23 13:51:29 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Chapman X-Patchwork-Id: 13740073 X-Patchwork-Delegate: kuba@kernel.org Received: from mail.katalix.com (mail.katalix.com [3.9.82.81]) by smtp.subspace.kernel.org (Postfix) with ESMTP id A6AA1137C34 for ; Tue, 23 Jul 2024 13:51:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=3.9.82.81 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721742713; cv=none; b=JveQMNchu/H6xubi8WwYM0pbv18LvnMgAa1UqZVdIZUZ6udndvB5JTBHqAZ54IFr8SUbLwXg5ncUgG26yqzv7MQ5oWHRtxjfYrP3A3rcDiPHgr0c3NKgx+a/rQFp3rXnuTdc4nsBOXKOi4x/rPtl9f3eBkNc055b72H4DhbQIOU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721742713; c=relaxed/simple; bh=HHt4Rs59ItJk4kyCZ0wktex/LLSJEG72yOzbJlah1tA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=aZVdv3zVfobt+buPGUrXCjY21nG+ETv6rSM4WiVicunvkelcXLxwbM3fePV+wbI2wEoB1mpajHB7E0yaWRT0CYGTHMN6jj8GLbd6B6Ic5wqrrUWJ0VRoaZYuUEjyWBWviyHv4+4eYomKFgxI9Q4VkmaoiHdwumIPZGm6ORVuNHk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=katalix.com; spf=pass smtp.mailfrom=katalix.com; dkim=pass (2048-bit key) header.d=katalix.com header.i=@katalix.com header.b=3L6hj6/I; arc=none smtp.client-ip=3.9.82.81 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=katalix.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=katalix.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=katalix.com header.i=@katalix.com header.b="3L6hj6/I" Received: from katalix.com (unknown [IPv6:2a02:8010:6359:1:47:b279:6330:ae0d]) (Authenticated sender: james) by mail.katalix.com (Postfix) with ESMTPSA id 18E187DBBB; Tue, 23 Jul 2024 14:51:45 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=katalix.com; s=mail; t=1721742705; bh=HHt4Rs59ItJk4kyCZ0wktex/LLSJEG72yOzbJlah1tA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:From; z=From:=20James=20Chapman=20|To:=20netdev@vge r.kernel.org|Cc:=20davem@davemloft.net,=0D=0A=09edumazet@google.co m,=0D=0A=09kuba@kernel.org,=0D=0A=09pabeni@redhat.com,=0D=0A=09dsa hern@kernel.org,=0D=0A=09tparkin@katalix.com|Subject:=20[RFC=20PAT CH=2001/15]=20l2tp:=20lookup=20tunnel=20from=20socket=20without=20 using=20sk_user_data|Date:=20Tue,=2023=20Jul=202024=2014:51:29=20+ 0100|Message-Id:=20|In-Reply-To:=20|References:=20|MIME-Version:=201.0; b=3L6hj6/I3H0ZXfo37H+vv51k3yOGRZ8xPQzc13KDq0cN/ClalPJEQ97ujb2wmz/yD 4gol+pIMYQv/RxuV1WBW/cqhfBEHmfT6pWwtWUHgpfl7UQmvfzVdhF+i9ymqX9LdF3 fpJG6zOk5aGCLeRnxhyrmN1yZp4696Tt3PnRFyUQRGbncusE+QaVDUY39+JLfXzYJa AO5zPqDcsmaXh+WI52VXZrWRiQGaXvhla1h6d4es2fnm8Cm8D48O0PnrvMfSwzbHhP DLSFtzJiezp/4uRwCG6yfs9hrlVC6yMQNhI5cA2CYsRiMYKpciSFJ/fB1CxuYfsweT pdVCsdf4uBtIw== From: James Chapman To: netdev@vger.kernel.org Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, dsahern@kernel.org, tparkin@katalix.com Subject: [RFC PATCH 01/15] l2tp: lookup tunnel from socket without using sk_user_data Date: Tue, 23 Jul 2024 14:51:29 +0100 Message-Id: X-Mailer: git-send-email 2.34.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org X-Patchwork-State: RFC l2tp_sk_to_tunnel derives the tunnel from sk_user_data. Instead, lookup the tunnel by walking the tunnel IDR for a tunnel using the indicated sock. This is slow but l2tp_sk_to_tunnel is not used in the datapath so performance isn't critical. l2tp_tunnel_destruct needs a variant of l2tp_sk_to_tunnel which does not bump the tunnel refcount since the tunnel refcount is already 0. Change l2tp_sk_to_tunnel sk arg to const since it does not modify sk. --- net/l2tp/l2tp_core.c | 52 ++++++++++++++++++++++++++++++++++++-------- net/l2tp/l2tp_core.h | 5 +---- net/l2tp/l2tp_ip.c | 7 ++++-- net/l2tp/l2tp_ip6.c | 7 ++++-- 4 files changed, 54 insertions(+), 17 deletions(-) diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index c80ab3f26084..c97cd0fd8514 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -150,15 +150,43 @@ static void l2tp_session_free(struct l2tp_session *session) kfree(session); } -struct l2tp_tunnel *l2tp_sk_to_tunnel(struct sock *sk) +static struct l2tp_tunnel *__l2tp_sk_to_tunnel(const struct sock *sk) { - struct l2tp_tunnel *tunnel = sk->sk_user_data; + const struct net *net = sock_net(sk); + unsigned long tunnel_id, tmp; + struct l2tp_tunnel *tunnel; + struct l2tp_net *pn; + + WARN_ON_ONCE(!rcu_read_lock_bh_held()); + pn = l2tp_pernet(net); + idr_for_each_entry_ul(&pn->l2tp_tunnel_idr, tunnel, tmp, tunnel_id) { + if (tunnel && tunnel->sock == sk) + return tunnel; + } + + return NULL; +} - if (tunnel) - if (WARN_ON(tunnel->magic != L2TP_TUNNEL_MAGIC)) - return NULL; +struct l2tp_tunnel *l2tp_sk_to_tunnel(const struct sock *sk) +{ + const struct net *net = sock_net(sk); + unsigned long tunnel_id, tmp; + struct l2tp_tunnel *tunnel; + struct l2tp_net *pn; + + rcu_read_lock_bh(); + pn = l2tp_pernet(net); + idr_for_each_entry_ul(&pn->l2tp_tunnel_idr, tunnel, tmp, tunnel_id) { + if (tunnel && + tunnel->sock == sk && + refcount_inc_not_zero(&tunnel->ref_count)) { + rcu_read_unlock_bh(); + return tunnel; + } + } + rcu_read_unlock_bh(); - return tunnel; + return NULL; } EXPORT_SYMBOL_GPL(l2tp_sk_to_tunnel); @@ -1213,8 +1241,10 @@ EXPORT_SYMBOL_GPL(l2tp_xmit_skb); */ static void l2tp_tunnel_destruct(struct sock *sk) { - struct l2tp_tunnel *tunnel = l2tp_sk_to_tunnel(sk); + struct l2tp_tunnel *tunnel; + rcu_read_lock_bh(); + tunnel = __l2tp_sk_to_tunnel(sk); if (!tunnel) goto end; @@ -1242,6 +1272,7 @@ static void l2tp_tunnel_destruct(struct sock *sk) kfree_rcu(tunnel, rcu); end: + rcu_read_unlock_bh(); return; } @@ -1308,10 +1339,13 @@ static void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel) /* Tunnel socket destroy hook for UDP encapsulation */ static void l2tp_udp_encap_destroy(struct sock *sk) { - struct l2tp_tunnel *tunnel = l2tp_sk_to_tunnel(sk); + struct l2tp_tunnel *tunnel; - if (tunnel) + tunnel = l2tp_sk_to_tunnel(sk); + if (tunnel) { l2tp_tunnel_delete(tunnel); + l2tp_tunnel_dec_refcount(tunnel); + } } static void l2tp_tunnel_remove(struct net *net, struct l2tp_tunnel *tunnel) diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h index 8ac81bc1bc6f..a41cf6795df0 100644 --- a/net/l2tp/l2tp_core.h +++ b/net/l2tp/l2tp_core.h @@ -273,10 +273,7 @@ void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type); /* IOCTL helper for IP encap modules. */ int l2tp_ioctl(struct sock *sk, int cmd, int *karg); -/* Extract the tunnel structure from a socket's sk_user_data pointer, - * validating the tunnel magic feather. - */ -struct l2tp_tunnel *l2tp_sk_to_tunnel(struct sock *sk); +struct l2tp_tunnel *l2tp_sk_to_tunnel(const struct sock *sk); static inline int l2tp_get_l2specific_len(struct l2tp_session *session) { diff --git a/net/l2tp/l2tp_ip.c b/net/l2tp/l2tp_ip.c index e48aa177d74c..78243f993cda 100644 --- a/net/l2tp/l2tp_ip.c +++ b/net/l2tp/l2tp_ip.c @@ -235,14 +235,17 @@ static void l2tp_ip_close(struct sock *sk, long timeout) static void l2tp_ip_destroy_sock(struct sock *sk) { - struct l2tp_tunnel *tunnel = l2tp_sk_to_tunnel(sk); + struct l2tp_tunnel *tunnel; struct sk_buff *skb; while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) kfree_skb(skb); - if (tunnel) + tunnel = l2tp_sk_to_tunnel(sk); + if (tunnel) { l2tp_tunnel_delete(tunnel); + l2tp_tunnel_dec_refcount(tunnel); + } } static int l2tp_ip_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) diff --git a/net/l2tp/l2tp_ip6.c b/net/l2tp/l2tp_ip6.c index d217ff1f229e..3b0465f2d60d 100644 --- a/net/l2tp/l2tp_ip6.c +++ b/net/l2tp/l2tp_ip6.c @@ -246,14 +246,17 @@ static void l2tp_ip6_close(struct sock *sk, long timeout) static void l2tp_ip6_destroy_sock(struct sock *sk) { - struct l2tp_tunnel *tunnel = l2tp_sk_to_tunnel(sk); + struct l2tp_tunnel *tunnel; lock_sock(sk); ip6_flush_pending_frames(sk); release_sock(sk); - if (tunnel) + tunnel = l2tp_sk_to_tunnel(sk); + if (tunnel) { l2tp_tunnel_delete(tunnel); + l2tp_tunnel_dec_refcount(tunnel); + } } static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)