From patchwork Wed Aug 7 17:43:28 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Eric Blake X-Patchwork-Id: 13756550 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 76F9CC3DA7F for ; Wed, 7 Aug 2024 17:50:44 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sbknR-00076s-NG; Wed, 07 Aug 2024 13:50:01 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sbknP-000724-R7 for qemu-devel@nongnu.org; Wed, 07 Aug 2024 13:49:59 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sbknO-0000RV-0M for qemu-devel@nongnu.org; Wed, 07 Aug 2024 13:49:59 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1723052997; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=8xrc1r3NaGmUxA1XHAispy7DXme7ap+ScyWyMJR1bS8=; b=eg38c6MANajuhv1oQ93VqZDzQcKeaUdfEqCXrl3Z1AhtAlE0o1axYt+BRsBRT6SJfTwR5i YKDCiXBh7FC8VWpWjg+uc0ww3Kp5HZr8l0nhmM7bo0LbRlOL/T6g0+KTLtRNSMp6l09WxW 8mVogx6zuCi/oQf2LeTKLGxlD7W5/Dk= Received: from mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-284-UCfuqWf9MRSlIyAqQChiKA-1; Wed, 07 Aug 2024 13:49:56 -0400 X-MC-Unique: UCfuqWf9MRSlIyAqQChiKA-1 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id CE06C1955F38; Wed, 7 Aug 2024 17:49:54 +0000 (UTC) Received: from green.redhat.com (unknown [10.2.16.114]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id D2AD2300018D; Wed, 7 Aug 2024 17:49:52 +0000 (UTC) From: Eric Blake To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, hreitz@redhat.com, berrange@redhat.com, qemu-block@nongnu.org, den@virtuozzo.com, andrey.drobyshev@virtuozzo.com, alexander.ivanov@virtuozzo.com, vsementsov@yandex-team.ru Subject: [PATCH v4 2/7] nbd/server: Plumb in new args to nbd_client_add() Date: Wed, 7 Aug 2024 12:43:28 -0500 Message-ID: <20240807174943.771624-11-eblake@redhat.com> In-Reply-To: <20240807174943.771624-9-eblake@redhat.com> References: <20240807174943.771624-9-eblake@redhat.com> MIME-Version: 1.0 Content-type: text/plain X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Received-SPF: pass client-ip=170.10.133.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.144, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Upcoming patches to fix a CVE need to track an opaque pointer passed in by the owner of a client object, as well as reequest for a time limit on how fast negotiation must complete. Prepare for that by changing the signature of nbd_client_new() and adding an accessor to get at the opaque pointer, although for now the two servers (qemu-nbd.c and blockdev-nbd.c) do not change behavior. Suggested-by: Vladimir Sementsov-Ogievskiy Signed-off-by: Eric Blake Reviewed-by: Daniel P. Berrangé --- include/block/nbd.h | 11 ++++++++++- blockdev-nbd.c | 6 ++++-- nbd/server.c | 20 +++++++++++++++++--- qemu-nbd.c | 4 +++- 4 files changed, 34 insertions(+), 7 deletions(-) diff --git a/include/block/nbd.h b/include/block/nbd.h index 4e7bd6342f9..5fe14786414 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -33,6 +33,12 @@ typedef struct NBDMetaContexts NBDMetaContexts; extern const BlockExportDriver blk_exp_nbd; +/* + * NBD_DEFAULT_HANDSHAKE_LIMIT: Number of seconds in which client must + * succeed at NBD_OPT_GO before being forcefully dropped as too slow. + */ +#define NBD_DEFAULT_HANDSHAKE_LIMIT 10 + /* Handshake phase structs - this struct is passed on the wire */ typedef struct NBDOption { @@ -403,9 +409,12 @@ AioContext *nbd_export_aio_context(NBDExport *exp); NBDExport *nbd_export_find(const char *name); void nbd_client_new(QIOChannelSocket *sioc, + uint32_t handshake_limit, QCryptoTLSCreds *tlscreds, const char *tlsauthz, - void (*close_fn)(NBDClient *, bool)); + void (*close_fn)(NBDClient *, bool), + void *owner); +void *nbd_client_owner(NBDClient *client); void nbd_client_get(NBDClient *client); void nbd_client_put(NBDClient *client); diff --git a/blockdev-nbd.c b/blockdev-nbd.c index 213012435f4..11f878b6db3 100644 --- a/blockdev-nbd.c +++ b/blockdev-nbd.c @@ -64,8 +64,10 @@ static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc, nbd_update_server_watch(nbd_server); qio_channel_set_name(QIO_CHANNEL(cioc), "nbd-server"); - nbd_client_new(cioc, nbd_server->tlscreds, nbd_server->tlsauthz, - nbd_blockdev_client_closed); + /* TODO - expose handshake limit as QMP option */ + nbd_client_new(cioc, NBD_DEFAULT_HANDSHAKE_LIMIT, + nbd_server->tlscreds, nbd_server->tlsauthz, + nbd_blockdev_client_closed, NULL); } static void nbd_update_server_watch(NBDServerData *s) diff --git a/nbd/server.c b/nbd/server.c index ecd9366ba64..31b77bf0d4f 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -124,12 +124,14 @@ struct NBDMetaContexts { struct NBDClient { int refcount; /* atomic */ void (*close_fn)(NBDClient *client, bool negotiated); + void *owner; QemuMutex lock; NBDExport *exp; QCryptoTLSCreds *tlscreds; char *tlsauthz; + uint32_t handshake_limit; QIOChannelSocket *sioc; /* The underlying data channel */ QIOChannel *ioc; /* The current I/O channel which may differ (eg TLS) */ @@ -3191,6 +3193,7 @@ static coroutine_fn void nbd_co_client_start(void *opaque) qemu_co_mutex_init(&client->send_lock); + /* TODO - utilize client->handshake_limit */ if (nbd_negotiate(client, &local_err)) { if (local_err) { error_report_err(local_err); @@ -3205,14 +3208,17 @@ static coroutine_fn void nbd_co_client_start(void *opaque) } /* - * Create a new client listener using the given channel @sioc. + * Create a new client listener using the given channel @sioc and @owner. * Begin servicing it in a coroutine. When the connection closes, call - * @close_fn with an indication of whether the client completed negotiation. + * @close_fn with an indication of whether the client completed negotiation + * within @handshake_limit seconds (0 for unbounded). */ void nbd_client_new(QIOChannelSocket *sioc, + uint32_t handshake_limit, QCryptoTLSCreds *tlscreds, const char *tlsauthz, - void (*close_fn)(NBDClient *, bool)) + void (*close_fn)(NBDClient *, bool), + void *owner) { NBDClient *client; Coroutine *co; @@ -3225,13 +3231,21 @@ void nbd_client_new(QIOChannelSocket *sioc, object_ref(OBJECT(client->tlscreds)); } client->tlsauthz = g_strdup(tlsauthz); + client->handshake_limit = handshake_limit; client->sioc = sioc; qio_channel_set_delay(QIO_CHANNEL(sioc), false); object_ref(OBJECT(client->sioc)); client->ioc = QIO_CHANNEL(sioc); object_ref(OBJECT(client->ioc)); client->close_fn = close_fn; + client->owner = owner; co = qemu_coroutine_create(nbd_co_client_start, client); qemu_coroutine_enter(co); } + +void * +nbd_client_owner(NBDClient *client) +{ + return client->owner; +} diff --git a/qemu-nbd.c b/qemu-nbd.c index 8e104ef22c3..7bf86a6566b 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -390,7 +390,9 @@ static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc, nb_fds++; nbd_update_server_watch(); - nbd_client_new(cioc, tlscreds, tlsauthz, nbd_client_closed); + /* TODO - expose handshake limit as command line option */ + nbd_client_new(cioc, NBD_DEFAULT_HANDSHAKE_LIMIT, + tlscreds, tlsauthz, nbd_client_closed, NULL); } static void nbd_update_server_watch(void)