From patchwork Mon Nov 14 22:48:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Blake X-Patchwork-Id: 13042975 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 03444C433FE for ; Mon, 14 Nov 2022 23:57:53 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ouieR-0003cQ-Bq; Mon, 14 Nov 2022 18:14:03 -0500 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 1ouids-0001o2-Dj for qemu-devel@nongnu.org; Mon, 14 Nov 2022 18:13:28 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ouiGF-0002Mr-0b for qemu-devel@nongnu.org; Mon, 14 Nov 2022 17:49:04 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1668466142; 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=1NrkZVHAocJOLpKWjaSIw4pPOaz/H1tbWxK3Giv3VKM=; b=C8/Lw3vyDOgpxP8QdJTkqgtzQsNxoMq3D6FBJ/5gvpNsCk9XKofZG7QSBgpeWp5w/F4nHN IexFLZwH0QnLm2A/jYg+9mSEiXuCyyTkfYHr6S7H6Ey+KRItZ+alh98ldo72sJx4eaIoFj 28RZcmXFxA+xVzkVXl7/tjqL7cT3fLI= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-183-ngUCwPe3OpGx83CvUIPf1w-1; Mon, 14 Nov 2022 17:48:58 -0500 X-MC-Unique: ngUCwPe3OpGx83CvUIPf1w-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 7FB3B101AA45; Mon, 14 Nov 2022 22:48:58 +0000 (UTC) Received: from green.redhat.com (unknown [10.2.16.240]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0940D40AE7EF; Mon, 14 Nov 2022 22:48:57 +0000 (UTC) From: Eric Blake To: qemu-devel@nongnu.org Cc: qemu-block@nongnu.org, libguestfs@redhat.com, nbd@other.debian.org, Vladimir Sementsov-Ogievskiy Subject: [PATCH v2 05/15] nbd/server: Refactor handling of request payload Date: Mon, 14 Nov 2022 16:48:38 -0600 Message-Id: <20221114224848.2186298-6-eblake@redhat.com> In-Reply-To: <20221114224848.2186298-1-eblake@redhat.com> References: <20221114224141.cm5jgyxfmvie5xb5@redhat.com> <20221114224848.2186298-1-eblake@redhat.com> MIME-Version: 1.0 Content-type: text/plain X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 Received-SPF: pass client-ip=170.10.129.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 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_LOW=-0.7, RCVD_IN_MSPIKE_H2=-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 additions to support NBD 64-bit effect lengths allow for the possibility to distinguish between payload length (capped at 32M) and effect length (up to 63 bits). Without that extension, only the NBD_CMD_WRITE request has a payload; but with the extension, it makes sense to allow at least NBD_CMD_BLOCK_STATUS to have both a payload and effect length (where the payload is a limited-size struct that in turns gives the real effect length as well as a subset of known ids for which status is requested). Other future NBD commands may also have a request payload, so the 64-bit extension introduces a new NBD_CMD_FLAG_PAYLOAD_LEN that distinguishes between whether the header length is a payload length or an effect length, rather than hard-coding the decision based on the command. Note that we do not support the payload version of BLOCK_STATUS yet. For this patch, no semantic change is intended for a compliant client. For a non-compliant client, it is possible that the error behavior changes (a different message, a change on whether the connection is killed or remains alive for the next command, or so forth), but all errors should still be handled gracefully. Signed-off-by: Eric Blake --- nbd/server.c | 53 ++++++++++++++++++++++++++++++++---------------- nbd/trace-events | 1 + 2 files changed, 37 insertions(+), 17 deletions(-) diff --git a/nbd/server.c b/nbd/server.c index 7738f5f899..ad5c2052b5 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -2316,6 +2316,8 @@ static int nbd_co_receive_request(NBDRequestData *req, NBDRequest *request, Error **errp) { NBDClient *client = req->client; + bool extended_with_payload; + int payload_len = 0; int valid_flags; int ret; @@ -2329,27 +2331,40 @@ static int nbd_co_receive_request(NBDRequestData *req, NBDRequest *request, trace_nbd_co_receive_request_decode_type(request->handle, request->type, nbd_cmd_lookup(request->type)); - if (request->type != NBD_CMD_WRITE) { - /* No payload, we are ready to read the next request. */ - req->complete = true; - } - if (request->type == NBD_CMD_DISC) { /* Special case: we're going to disconnect without a reply, * whether or not flags, from, or len are bogus */ + req->complete = true; return -EIO; } + /* Payload and buffer handling. */ + extended_with_payload = client->extended_headers && + (request->flags & NBD_CMD_FLAG_PAYLOAD_LEN); if (request->type == NBD_CMD_READ || request->type == NBD_CMD_WRITE || - request->type == NBD_CMD_CACHE) - { + request->type == NBD_CMD_CACHE || extended_with_payload) { if (request->len > NBD_MAX_BUFFER_SIZE) { error_setg(errp, "len (%" PRIu64" ) is larger than max len (%u)", request->len, NBD_MAX_BUFFER_SIZE); return -EINVAL; } - if (request->type != NBD_CMD_CACHE) { + if (request->type == NBD_CMD_WRITE || extended_with_payload) { + payload_len = request->len; + if (request->type != NBD_CMD_WRITE) { + /* + * For now, we don't support payloads on other + * commands; but we can keep the connection alive. + */ + request->len = 0; + } else if (client->extended_headers && !extended_with_payload) { + /* The client is noncompliant. Trace it, but proceed. */ + trace_nbd_co_receive_ext_payload_compliance(request->from, + request->len); + } + } + + if (request->type == NBD_CMD_WRITE || request->type == NBD_CMD_READ) { req->data = blk_try_blockalign(client->exp->common.blk, request->len); if (req->data == NULL) { @@ -2359,18 +2374,20 @@ static int nbd_co_receive_request(NBDRequestData *req, NBDRequest *request, } } - if (request->type == NBD_CMD_WRITE) { - assert(request->len <= NBD_MAX_BUFFER_SIZE); - if (nbd_read(client->ioc, req->data, request->len, "CMD_WRITE data", - errp) < 0) - { + if (payload_len) { + if (req->data) { + ret = nbd_read(client->ioc, req->data, payload_len, + "CMD_WRITE data", errp); + } else { + ret = nbd_drop(client->ioc, payload_len, errp); + } + if (ret < 0) { return -EIO; } - req->complete = true; - trace_nbd_co_receive_request_payload_received(request->handle, - request->len); + payload_len); } + req->complete = true; /* Sanity checks. */ if (client->exp->nbdflags & NBD_FLAG_READ_ONLY && @@ -2400,7 +2417,9 @@ static int nbd_co_receive_request(NBDRequestData *req, NBDRequest *request, client->check_align); } valid_flags = NBD_CMD_FLAG_FUA; - if (request->type == NBD_CMD_READ && client->structured_reply) { + if (request->type == NBD_CMD_WRITE && client->extended_headers) { + valid_flags |= NBD_CMD_FLAG_PAYLOAD_LEN; + } else if (request->type == NBD_CMD_READ && client->structured_reply) { valid_flags |= NBD_CMD_FLAG_DF; } else if (request->type == NBD_CMD_WRITE_ZEROES) { valid_flags |= NBD_CMD_FLAG_NO_HOLE | NBD_CMD_FLAG_FAST_ZERO; diff --git a/nbd/trace-events b/nbd/trace-events index e2c1d68688..adf5666e20 100644 --- a/nbd/trace-events +++ b/nbd/trace-events @@ -71,6 +71,7 @@ nbd_co_send_extents(uint64_t handle, unsigned int extents, uint32_t id, uint64_t nbd_co_send_structured_error(uint64_t handle, int err, const char *errname, const char *msg) "Send structured error reply: handle = %" PRIu64 ", error = %d (%s), msg = '%s'" nbd_co_receive_request_decode_type(uint64_t handle, uint16_t type, const char *name) "Decoding type: handle = %" PRIu64 ", type = %" PRIu16 " (%s)" nbd_co_receive_request_payload_received(uint64_t handle, uint64_t len) "Payload received: handle = %" PRIu64 ", len = %" PRIu64 +nbd_co_receive_ext_payload_compliance(uint64_t from, uint64_t len) "client sent non-compliant write without payload flag: from=0x%" PRIx64 ", len=0x%" PRIx64 nbd_co_receive_align_compliance(const char *op, uint64_t from, uint64_t len, uint32_t align) "client sent non-compliant unaligned %s request: from=0x%" PRIx64 ", len=0x%" PRIx64 ", align=0x%" PRIx32 nbd_trip(void) "Reading request"