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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0B8E5C636D0 for ; Mon, 30 Jan 2023 14:04:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236946AbjA3OEa (ORCPT ); Mon, 30 Jan 2023 09:04:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46564 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236989AbjA3OEX (ORCPT ); Mon, 30 Jan 2023 09:04:23 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C38F6193F2 for ; Mon, 30 Jan 2023 06:04:22 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 7BB55B80C9B for ; Mon, 30 Jan 2023 14:04:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C8593C433D2; Mon, 30 Jan 2023 14:04:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1675087460; bh=M2iVxVjjRJlpNjPZWgAqDm81DU7ZJe6FFbF92Hwt9P0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=f6aTwIk/z0cI21gbi1vUl0hl+g4BeZ+co96I9eUK/JaOTXzhuRq8FCCzDS2THNMyj 2sLOpbPCOA1lz3ZytSjh6N+B3V/3Pb3xAO3cI2iBwGMUn5yDXscRvlww8oh0UHuseE QYfLk6BkRh3aJv/oKOMBd9UHxHda9We+Es8rw8wY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sergey Senozhatsky , Namjae Jeon , Steve French Subject: [PATCH 6.1 216/313] ksmbd: add max connections parameter Date: Mon, 30 Jan 2023 14:50:51 +0100 Message-Id: <20230130134346.764594957@linuxfoundation.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230130134336.532886729@linuxfoundation.org> References: <20230130134336.532886729@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Namjae Jeon commit 0d0d4680db22eda1eea785c47bbf66a9b33a8b16 upstream. Add max connections parameter to limit number of maximum simultaneous connections. Fixes: 0626e6641f6b ("cifsd: add server handler for central processing and tranport layers") Cc: stable@vger.kernel.org Reviewed-by: Sergey Senozhatsky Signed-off-by: Namjae Jeon Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman --- fs/ksmbd/ksmbd_netlink.h | 3 ++- fs/ksmbd/server.h | 1 + fs/ksmbd/transport_ipc.c | 3 +++ fs/ksmbd/transport_tcp.c | 17 ++++++++++++++++- 4 files changed, 22 insertions(+), 2 deletions(-) --- a/fs/ksmbd/ksmbd_netlink.h +++ b/fs/ksmbd/ksmbd_netlink.h @@ -105,7 +105,8 @@ struct ksmbd_startup_request { __u32 sub_auth[3]; /* Subauth value for Security ID */ __u32 smb2_max_credits; /* MAX credits */ __u32 smbd_max_io_size; /* smbd read write size */ - __u32 reserved[127]; /* Reserved room */ + __u32 max_connections; /* Number of maximum simultaneous connections */ + __u32 reserved[126]; /* Reserved room */ __u32 ifc_list_sz; /* interfaces list size */ __s8 ____payload[]; }; --- a/fs/ksmbd/server.h +++ b/fs/ksmbd/server.h @@ -41,6 +41,7 @@ struct ksmbd_server_config { unsigned int share_fake_fscaps; struct smb_sid domain_sid; unsigned int auth_mechs; + unsigned int max_connections; char *conf[SERVER_CONF_WORK_GROUP + 1]; }; --- a/fs/ksmbd/transport_ipc.c +++ b/fs/ksmbd/transport_ipc.c @@ -308,6 +308,9 @@ static int ipc_server_config_on_startup( if (req->smbd_max_io_size) init_smbd_max_io_size(req->smbd_max_io_size); + if (req->max_connections) + server_conf.max_connections = req->max_connections; + ret = ksmbd_set_netbios_name(req->netbios_name); ret |= ksmbd_set_server_string(req->server_string); ret |= ksmbd_set_work_group(req->work_group); --- a/fs/ksmbd/transport_tcp.c +++ b/fs/ksmbd/transport_tcp.c @@ -15,6 +15,8 @@ #define IFACE_STATE_DOWN BIT(0) #define IFACE_STATE_CONFIGURED BIT(1) +static atomic_t active_num_conn; + struct interface { struct task_struct *ksmbd_kthread; struct socket *ksmbd_socket; @@ -185,8 +187,10 @@ static int ksmbd_tcp_new_connection(stru struct tcp_transport *t; t = alloc_transport(client_sk); - if (!t) + if (!t) { + sock_release(client_sk); return -ENOMEM; + } csin = KSMBD_TCP_PEER_SOCKADDR(KSMBD_TRANS(t)->conn); if (kernel_getpeername(client_sk, csin) < 0) { @@ -239,6 +243,15 @@ static int ksmbd_kthread_fn(void *p) continue; } + if (server_conf.max_connections && + atomic_inc_return(&active_num_conn) >= server_conf.max_connections) { + pr_info_ratelimited("Limit the maximum number of connections(%u)\n", + atomic_read(&active_num_conn)); + atomic_dec(&active_num_conn); + sock_release(client_sk); + continue; + } + ksmbd_debug(CONN, "connect success: accepted new connection\n"); client_sk->sk->sk_rcvtimeo = KSMBD_TCP_RECV_TIMEOUT; client_sk->sk->sk_sndtimeo = KSMBD_TCP_SEND_TIMEOUT; @@ -368,6 +381,8 @@ static int ksmbd_tcp_writev(struct ksmbd static void ksmbd_tcp_disconnect(struct ksmbd_transport *t) { free_transport(TCP_TRANS(t)); + if (server_conf.max_connections) + atomic_dec(&active_num_conn); } static void tcp_destroy_socket(struct socket *ksmbd_socket)