From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C81CDC43460 for ; Tue, 20 Apr 2021 15:44:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8AD4C613B2 for ; Tue, 20 Apr 2021 15:44:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233100AbhDTPo6 (ORCPT ); Tue, 20 Apr 2021 11:44:58 -0400 Received: from smtp-fw-6001.amazon.com ([52.95.48.154]:60957 "EHLO smtp-fw-6001.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232910AbhDTPot (ORCPT ); Tue, 20 Apr 2021 11:44:49 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.co.jp; i=@amazon.co.jp; q=dns/txt; s=amazon201209; t=1618933459; x=1650469459; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=Ace2/yQjy3YabkwxzWoQwnwDO/gFnCB+2fW1JZYyE8g=; b=cGnLnR4L8dqWvagb9N22orgYCCSV37L6bMRPMM6u935cxtVVC3HWTV7P XpoNOAcJC1o0o6YeZdg4x1NwWN8qIsvsiW7WPpifNzEDksXnzk1bnD0ye p8q1vAUyq1Ex7lF366reHpZ3R8qak80mQhRRky5/JH4w586WB99t69JcZ M=; X-IronPort-AV: E=Sophos;i="5.82,237,1613433600"; d="scan'208";a="108636730" Received: from iad12-co-svc-p1-lb1-vlan2.amazon.com (HELO email-inbound-relay-2b-baacba05.us-west-2.amazon.com) ([10.43.8.2]) by smtp-border-fw-out-6001.iad6.amazon.com with ESMTP; 20 Apr 2021 15:44:17 +0000 Received: from EX13MTAUWB001.ant.amazon.com (pdx1-ws-svc-p6-lb9-vlan2.pdx.amazon.com [10.236.137.194]) by email-inbound-relay-2b-baacba05.us-west-2.amazon.com (Postfix) with ESMTPS id 78D53A1C2A; Tue, 20 Apr 2021 15:44:13 +0000 (UTC) Received: from EX13D04ANC001.ant.amazon.com (10.43.157.89) by EX13MTAUWB001.ant.amazon.com (10.43.161.207) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Tue, 20 Apr 2021 15:44:12 +0000 Received: from 88665a182662.ant.amazon.com (10.43.161.41) by EX13D04ANC001.ant.amazon.com (10.43.157.89) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Tue, 20 Apr 2021 15:44:07 +0000 From: Kuniyuki Iwashima To: "David S . Miller" , Jakub Kicinski , Eric Dumazet , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau CC: Benjamin Herrenschmidt , Kuniyuki Iwashima , Kuniyuki Iwashima , , , Subject: [PATCH v3 bpf-next 05/11] tcp: Migrate TCP_ESTABLISHED/TCP_SYN_RECV sockets in accept queues. Date: Wed, 21 Apr 2021 00:41:34 +0900 Message-ID: <20210420154140.80034-6-kuniyu@amazon.co.jp> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210420154140.80034-1-kuniyu@amazon.co.jp> References: <20210420154140.80034-1-kuniyu@amazon.co.jp> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.43.161.41] X-ClientProxiedBy: EX13P01UWB001.ant.amazon.com (10.43.161.59) To EX13D04ANC001.ant.amazon.com (10.43.157.89) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When we call close() or shutdown() for listening sockets, each child socket in the accept queue are freed at inet_csk_listen_stop(). If we can get a new listener by reuseport_migrate_sock() and clone the request by reqsk_clone(), we try to add it into the new listener's accept queue by inet_csk_reqsk_queue_add(). If it fails, we have to call __reqsk_free() to call sock_put() for its listener and free the cloned request. After putting the full socket into ehash, tcp_v[46]_syn_recv_sock() sets NULL to ireq_opt/pktopts in struct inet_request_sock, but ipv6_opt can be non-NULL. So, we have to set NULL to ipv6_opt of the old request to avoid double free. Note that we do not update req->rsk_listener and instead clone the req to migrate because another path may reference the original request. If we protected it by RCU, we would need to add rcu_read_lock() in many places. Link: https://lore.kernel.org/netdev/20201209030903.hhow5r53l6fmozjn@kafai-mbp.dhcp.thefacebook.com/ Suggested-by: Martin KaFai Lau Signed-off-by: Kuniyuki Iwashima --- include/net/request_sock.h | 2 ++ net/core/request_sock.c | 37 +++++++++++++++++++++++++++++++++ net/ipv4/inet_connection_sock.c | 31 ++++++++++++++++++++++++++- 3 files changed, 69 insertions(+), 1 deletion(-) diff --git a/include/net/request_sock.h b/include/net/request_sock.h index 29e41ff3ec93..c6d6cfd3c93b 100644 --- a/include/net/request_sock.h +++ b/include/net/request_sock.h @@ -190,6 +190,8 @@ void reqsk_queue_alloc(struct request_sock_queue *queue); void reqsk_fastopen_remove(struct sock *sk, struct request_sock *req, bool reset); +struct request_sock *reqsk_clone(struct request_sock *req, struct sock *sk); + static inline bool reqsk_queue_empty(const struct request_sock_queue *queue) { return READ_ONCE(queue->rskq_accept_head) == NULL; diff --git a/net/core/request_sock.c b/net/core/request_sock.c index f35c2e998406..82cf9fbe2668 100644 --- a/net/core/request_sock.c +++ b/net/core/request_sock.c @@ -130,3 +130,40 @@ void reqsk_fastopen_remove(struct sock *sk, struct request_sock *req, out: spin_unlock_bh(&fastopenq->lock); } + +struct request_sock *reqsk_clone(struct request_sock *req, struct sock *sk) +{ + struct sock *req_sk, *nreq_sk; + struct request_sock *nreq; + + nreq = kmem_cache_alloc(req->rsk_ops->slab, GFP_ATOMIC | __GFP_NOWARN); + if (!nreq) { + /* paired with refcount_inc_not_zero() in reuseport_migrate_sock() */ + sock_put(sk); + return NULL; + } + + req_sk = req_to_sk(req); + nreq_sk = req_to_sk(nreq); + + memcpy(nreq_sk, req_sk, + offsetof(struct sock, sk_dontcopy_begin)); + memcpy(&nreq_sk->sk_dontcopy_end, &req_sk->sk_dontcopy_end, + req->rsk_ops->obj_size - offsetof(struct sock, sk_dontcopy_end)); + + nreq_sk->sk_tx_queue_mapping = req_sk->sk_tx_queue_mapping; +#ifdef CONFIG_XPS + nreq_sk->sk_rx_queue_mapping = req_sk->sk_rx_queue_mapping; +#endif + nreq_sk->sk_incoming_cpu = req_sk->sk_incoming_cpu; + + nreq->rsk_listener = sk; + + /* We need not acquire fastopenq->lock + * because the child socket is locked in inet_csk_listen_stop(). + */ + if (tcp_rsk(nreq)->tfo_listener) + rcu_assign_pointer(tcp_sk(nreq->sk)->fastopen_rsk, nreq); + + return nreq; +} diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index fa806e9167ec..851992405826 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -695,6 +695,13 @@ int inet_rtx_syn_ack(const struct sock *parent, struct request_sock *req) } EXPORT_SYMBOL(inet_rtx_syn_ack); +static void reqsk_migrate_reset(struct request_sock *req) +{ +#if IS_ENABLED(CONFIG_IPV6) + inet_rsk(req)->ipv6_opt = NULL; +#endif +} + /* return true if req was found in the ehash table */ static bool reqsk_queue_unlink(struct request_sock *req) { @@ -1036,14 +1043,36 @@ void inet_csk_listen_stop(struct sock *sk) * of the variants now. --ANK */ while ((req = reqsk_queue_remove(queue, sk)) != NULL) { - struct sock *child = req->sk; + struct sock *child = req->sk, *nsk; + struct request_sock *nreq; local_bh_disable(); bh_lock_sock(child); WARN_ON(sock_owned_by_user(child)); sock_hold(child); + nsk = reuseport_migrate_sock(sk, child, NULL); + if (nsk) { + nreq = reqsk_clone(req, nsk); + if (nreq) { + refcount_set(&nreq->rsk_refcnt, 1); + + if (inet_csk_reqsk_queue_add(nsk, nreq, child)) { + reqsk_migrate_reset(req); + } else { + reqsk_migrate_reset(nreq); + __reqsk_free(nreq); + } + + /* inet_csk_reqsk_queue_add() has already + * called inet_child_forget() on failure case. + */ + goto skip_child_forget; + } + } + inet_child_forget(sk, req, child); +skip_child_forget: reqsk_put(req); bh_unlock_sock(child); local_bh_enable(); -- 2.30.2