From patchwork Thu Aug 10 17:36:54 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Blake X-Patchwork-Id: 13349749 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 D2B88C41513 for ; Thu, 10 Aug 2023 17:43:19 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qU9g9-00041W-W9; Thu, 10 Aug 2023 13:42:34 -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 1qU9g6-0003x5-Dh for qemu-devel@nongnu.org; Thu, 10 Aug 2023 13:42:30 -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 1qU9g3-0004z5-36 for qemu-devel@nongnu.org; Thu, 10 Aug 2023 13:42:30 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1691689346; 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=F4Nrz5+/qHHSWsoO0SoMCeLa1v25uK7kpVfCLPubuw8=; b=hFJdgXelGpiSlMfiprSlFmh/czH9ex5GxKBkOUtJmUcDvKlznYDgBEDWLSQ+RNwPRjLakh 5HL+RVCJpjLRg1rbDDoQADLfuEz4MVlkN8x1uDNB5/keXCoa0gmwtbtzs/F9G8JRe26jFe CRancLq4Y1bnTjsiioUDpc1YYV5aQes= Received: from mimecast-mx02.redhat.com (66.187.233.73 [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-532-jvnStdDNMoai6hPJ3ztU4A-1; Thu, 10 Aug 2023 13:42:23 -0400 X-MC-Unique: jvnStdDNMoai6hPJ3ztU4A-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id EC7003804522; Thu, 10 Aug 2023 17:42:22 +0000 (UTC) Received: from green.redhat.com (unknown [10.2.16.169]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9AFC01121315; Thu, 10 Aug 2023 17:42:22 +0000 (UTC) From: Eric Blake To: qemu-devel@nongnu.org Cc: qemu-block@nongnu.org, vsementsov@yandex-team.ru Subject: [PATCH v5 07/17] nbd/server: Prepare to receive extended header requests Date: Thu, 10 Aug 2023 12:36:54 -0500 Message-ID: <20230810173646.17695-26-eblake@redhat.com> In-Reply-To: <20230810173646.17695-19-eblake@redhat.com> References: <20230810173646.17695-19-eblake@redhat.com> MIME-Version: 1.0 Content-type: text/plain X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 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: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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=unavailable 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 Although extended mode is not yet enabled, once we do turn it on, we need to accept extended requests for all messages. Previous patches have already taken care of supporting 64-bit lengths, now we just need to read it off the wire. Note that this implementation will block indefinitely on a buggy client that sends a non-extended payload (that is, we try to read a full packet before we ever check the magic number, but a client that mistakenly sends a simple request after negotiating extended headers doesn't send us enough bytes), but it's no different from any other client that stops talking to us partway through a packet and thus not worth coding around. Signed-off-by: Eric Blake Reviewed-by: Vladimir Sementsov-Ogievskiy --- v5: no change v4: new patch, split out from v3 9/14 --- nbd/nbd-internal.h | 5 ++++- nbd/server.c | 43 ++++++++++++++++++++++++++++++------------- 2 files changed, 34 insertions(+), 14 deletions(-) diff --git a/nbd/nbd-internal.h b/nbd/nbd-internal.h index 133b1d94b50..dfa02f77ee4 100644 --- a/nbd/nbd-internal.h +++ b/nbd/nbd-internal.h @@ -34,8 +34,11 @@ * https://github.com/yoe/nbd/blob/master/doc/proto.md */ -/* Size of all NBD_OPT_*, without payload */ +/* Size of all compact NBD_CMD_*, without payload */ #define NBD_REQUEST_SIZE (4 + 2 + 2 + 8 + 8 + 4) +/* Size of all extended NBD_CMD_*, without payload */ +#define NBD_EXTENDED_REQUEST_SIZE (4 + 2 + 2 + 8 + 8 + 8) + /* Size of all NBD_REP_* sent in answer to most NBD_OPT_*, without payload */ #define NBD_REPLY_SIZE (4 + 4 + 8) /* Size of reply to NBD_OPT_EXPORT_NAME */ diff --git a/nbd/server.c b/nbd/server.c index 9b7fb3c55ae..566afe9527c 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -1415,11 +1415,13 @@ nbd_read_eof(NBDClient *client, void *buffer, size_t size, Error **errp) static int coroutine_fn nbd_receive_request(NBDClient *client, NBDRequest *request, Error **errp) { - uint8_t buf[NBD_REQUEST_SIZE]; - uint32_t magic; + uint8_t buf[NBD_EXTENDED_REQUEST_SIZE]; + uint32_t magic, expect; int ret; + size_t size = client->mode >= NBD_MODE_EXTENDED ? + NBD_EXTENDED_REQUEST_SIZE : NBD_REQUEST_SIZE; - ret = nbd_read_eof(client, buf, sizeof(buf), errp); + ret = nbd_read_eof(client, buf, size, errp); if (ret < 0) { return ret; } @@ -1427,13 +1429,21 @@ static int coroutine_fn nbd_receive_request(NBDClient *client, NBDRequest *reque return -EIO; } - /* Request - [ 0 .. 3] magic (NBD_REQUEST_MAGIC) - [ 4 .. 5] flags (NBD_CMD_FLAG_FUA, ...) - [ 6 .. 7] type (NBD_CMD_READ, ...) - [ 8 .. 15] cookie - [16 .. 23] from - [24 .. 27] len + /* + * Compact request + * [ 0 .. 3] magic (NBD_REQUEST_MAGIC) + * [ 4 .. 5] flags (NBD_CMD_FLAG_FUA, ...) + * [ 6 .. 7] type (NBD_CMD_READ, ...) + * [ 8 .. 15] cookie + * [16 .. 23] from + * [24 .. 27] len + * Extended request + * [ 0 .. 3] magic (NBD_EXTENDED_REQUEST_MAGIC) + * [ 4 .. 5] flags (NBD_CMD_FLAG_FUA, NBD_CMD_FLAG_PAYLOAD_LEN, ...) + * [ 6 .. 7] type (NBD_CMD_READ, ...) + * [ 8 .. 15] cookie + * [16 .. 23] from + * [24 .. 31] len */ magic = ldl_be_p(buf); @@ -1441,13 +1451,20 @@ static int coroutine_fn nbd_receive_request(NBDClient *client, NBDRequest *reque request->type = lduw_be_p(buf + 6); request->cookie = ldq_be_p(buf + 8); request->from = ldq_be_p(buf + 16); - request->len = ldl_be_p(buf + 24); /* widen 32 to 64 bits */ + if (client->mode >= NBD_MODE_EXTENDED) { + request->len = ldq_be_p(buf + 24); + expect = NBD_EXTENDED_REQUEST_MAGIC; + } else { + request->len = ldl_be_p(buf + 24); /* widen 32 to 64 bits */ + expect = NBD_REQUEST_MAGIC; + } trace_nbd_receive_request(magic, request->flags, request->type, request->from, request->len); - if (magic != NBD_REQUEST_MAGIC) { - error_setg(errp, "invalid magic (got 0x%" PRIx32 ")", magic); + if (magic != expect) { + error_setg(errp, "invalid magic (got 0x%" PRIx32 ", expected 0x%" + PRIx32 ")", magic, expect); return -EINVAL; } return 0;