From patchwork Fri Nov 30 22:03:39 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Blake X-Patchwork-Id: 10707337 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 48C7914BD for ; Fri, 30 Nov 2018 22:11:54 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 38A5E3047E for ; Fri, 30 Nov 2018 22:11:54 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2AF5430489; Fri, 30 Nov 2018 22:11:54 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 751403047E for ; Fri, 30 Nov 2018 22:11:53 +0000 (UTC) Received: from localhost ([::1]:34862 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gSr0q-0003f0-Ke for patchwork-qemu-devel@patchwork.kernel.org; Fri, 30 Nov 2018 17:11:52 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56072) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gSqtO-0004Rs-1x for qemu-devel@nongnu.org; Fri, 30 Nov 2018 17:04:11 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gSqtK-0004cM-PL for qemu-devel@nongnu.org; Fri, 30 Nov 2018 17:04:09 -0500 Received: from mx1.redhat.com ([209.132.183.28]:55228) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gSqtF-00045I-QP; Fri, 30 Nov 2018 17:04:02 -0500 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 0D0D91F8C5; Fri, 30 Nov 2018 22:04:01 +0000 (UTC) Received: from red.redhat.com (ovpn-117-105.phx2.redhat.com [10.3.117.105]) by smtp.corp.redhat.com (Postfix) with ESMTP id 699B51057073; Fri, 30 Nov 2018 22:04:00 +0000 (UTC) From: Eric Blake To: qemu-devel@nongnu.org Date: Fri, 30 Nov 2018 16:03:39 -0600 Message-Id: <20181130220344.3350618-11-eblake@redhat.com> In-Reply-To: <20181130220344.3350618-1-eblake@redhat.com> References: <20181130220344.3350618-1-eblake@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Fri, 30 Nov 2018 22:04:01 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH 10/14] nbd/client: Split handshake into two functions X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: nsoffer@redhat.com, vsementsov@virtuozzo.com, jsnow@redhat.com, rjones@redhat.com, qemu-block@nongnu.org Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP An upcoming patch will add the ability for qemu-nbd to list the services provided by an NBD server. Share the common code of the TLS handshake by splitting the initial exchange into a separate function, leaving only the export handling in the original function. Functionally, there should be no change in behavior in this patch, although some of the code motion may be difficult to follow due to indentation changes (view with 'git diff -w' for a smaller changeset). Signed-off-by: Eric Blake Reviewed-by: Richard W.M. Jones Reviewed-by: Vladimir Sementsov-Ogievskiy --- nbd/client.c | 142 ++++++++++++++++++++++++++++++----------------- nbd/trace-events | 2 +- 2 files changed, 92 insertions(+), 52 deletions(-) diff --git a/nbd/client.c b/nbd/client.c index 1ed5009642e..a282712724d 100644 --- a/nbd/client.c +++ b/nbd/client.c @@ -768,21 +768,22 @@ static int nbd_negotiate_simple_meta_context(QIOChannel *ioc, return received || opt == NBD_OPT_LIST_META_CONTEXT; } -int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, - const char *hostname, QIOChannel **outioc, - NBDExportInfo *info, Error **errp) +/* Start the handshake to the server. After a positive return, the server + * is ready to accept additional NBD_OPT requests. + * Returns: negative errno: failure talking to server + * 0: server is oldstyle, client must still parse export size + * 1: server is newstyle, but can only accept EXPORT_NAME + * 2: server is newstyle, but lacks structured replies + * 3: server is newstyle and set up for structured replies + */ +static int nbd_start_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, + const char *hostname, QIOChannel **outioc, + bool structured_reply, bool *zeroes, + Error **errp) { uint64_t magic; - bool zeroes = true; - bool structured_reply = info->structured_reply; - bool base_allocation = info->base_allocation; - trace_nbd_receive_negotiate(tlscreds, hostname ? hostname : ""); - - assert(info->name); - trace_nbd_receive_negotiate_name(info->name); - info->structured_reply = false; - info->base_allocation = false; + trace_nbd_start_negotiate(tlscreds, hostname ? hostname : ""); if (outioc) { *outioc = NULL; @@ -827,7 +828,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, clientflags |= NBD_FLAG_C_FIXED_NEWSTYLE; } if (globalflags & NBD_FLAG_NO_ZEROES) { - zeroes = false; + *zeroes = false; clientflags |= NBD_FLAG_C_NO_ZEROES; } /* client requested flags */ @@ -849,7 +850,7 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, } } if (fixedNewStyle) { - int result; + int result = 0; if (structured_reply) { result = nbd_request_simple_option(ioc, @@ -858,42 +859,86 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, if (result < 0) { return -EINVAL; } - info->structured_reply = result == 1; } + return 2 + result; + } else { + return 1; + } + } else if (magic == NBD_CLIENT_MAGIC) { + if (tlscreds) { + error_setg(errp, "Server does not support STARTTLS"); + return -EINVAL; + } + return 0; + } else { + error_setg(errp, "Bad magic received"); + return -EINVAL; + } +} - if (info->structured_reply && base_allocation) { - result = nbd_negotiate_simple_meta_context( +/* Connect to server, complete negotiation, and move into transmission phase. + * Returns: negative errno: failure talking to server + * 0: server is connected + */ +int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, + const char *hostname, QIOChannel **outioc, + NBDExportInfo *info, Error **errp) +{ + int result; + bool zeroes = true; + bool base_allocation = info->base_allocation; + uint32_t oldflags; + + assert(info->name); + trace_nbd_receive_negotiate_name(info->name); + + result = nbd_start_negotiate(ioc, tlscreds, hostname, outioc, + info->structured_reply, &zeroes, errp); + + info->structured_reply = false; + info->base_allocation = false; + if (tlscreds && *outioc) { + ioc = *outioc; + } + + switch (result) { + case 3: /* newstyle, with structured replies */ + info->structured_reply = true; + if (base_allocation) { + result = nbd_negotiate_simple_meta_context( ioc, NBD_OPT_SET_META_CONTEXT, info->x_dirty_bitmap ?: "base:allocation", info, errp); - if (result < 0) { - return -EINVAL; - } - info->base_allocation = result == 1; - } - - /* Try NBD_OPT_GO first - if it works, we are done (it - * also gives us a good message if the server requires - * TLS). If it is not available, fall back to - * NBD_OPT_LIST for nicer error messages about a missing - * export, then use NBD_OPT_EXPORT_NAME. */ - result = nbd_opt_go(ioc, info, errp); if (result < 0) { return -EINVAL; } - if (result > 0) { - return 0; - } - /* Check our desired export is present in the - * server export list. Since NBD_OPT_EXPORT_NAME - * cannot return an error message, running this - * query gives us better error reporting if the - * export name is not available. - */ - if (nbd_receive_query_exports(ioc, info->name, errp) < 0) { - return -EINVAL; - } + info->base_allocation = result == 1; } + /* fall through */ + case 2: /* newstyle, try OPT_GO */ + /* Try NBD_OPT_GO first - if it works, we are done (it + * also gives us a good message if the server requires + * TLS). If it is not available, fall back to + * NBD_OPT_LIST for nicer error messages about a missing + * export, then use NBD_OPT_EXPORT_NAME. */ + result = nbd_opt_go(ioc, info, errp); + if (result < 0) { + return -EINVAL; + } + if (result > 0) { + return 0; + } + /* Check our desired export is present in the + * server export list. Since NBD_OPT_EXPORT_NAME + * cannot return an error message, running this + * query gives us better error reporting if the + * export name is not available. + */ + if (nbd_receive_query_exports(ioc, info->name, errp) < 0) { + return -EINVAL; + } + /* fall through */ + case 1: /* newstyle, but limited to EXPORT_NAME */ /* write the export name request */ if (nbd_send_option_request(ioc, NBD_OPT_EXPORT_NAME, -1, info->name, errp) < 0) { @@ -912,17 +957,12 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, return -EINVAL; } info->flags = be16_to_cpu(info->flags); - } else if (magic == NBD_CLIENT_MAGIC) { - uint32_t oldflags; - + break; + case 0: /* oldstyle, parse length and flags */ if (*info->name) { error_setg(errp, "Server does not support non-empty export names"); return -EINVAL; } - if (tlscreds) { - error_setg(errp, "Server does not support STARTTLS"); - return -EINVAL; - } if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) { error_prepend(errp, "Failed to read export length: "); @@ -940,9 +980,9 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLSCreds *tlscreds, return -EINVAL; } info->flags = oldflags; - } else { - error_setg(errp, "Bad magic received"); - return -EINVAL; + break; + default: + return result; } trace_nbd_receive_negotiate_size_flags(info->size, info->flags); diff --git a/nbd/trace-events b/nbd/trace-events index 5d0d202fad2..570b04997ff 100644 --- a/nbd/trace-events +++ b/nbd/trace-events @@ -12,7 +12,7 @@ nbd_receive_starttls_new_client(void) "Setting up TLS" nbd_receive_starttls_tls_handshake(void) "Starting TLS handshake" nbd_opt_meta_request(const char *opt, const char *context, const char *export) "Requesting to %s %s for export %s" nbd_opt_meta_reply(const char *context, uint32_t id) "Received mapping of context %s to id %" PRIu32 -nbd_receive_negotiate(void *tlscreds, const char *hostname) "Receiving negotiation tlscreds=%p hostname=%s" +nbd_start_negotiate(void *tlscreds, const char *hostname) "Receiving negotiation tlscreds=%p hostname=%s" nbd_receive_negotiate_magic(uint64_t magic) "Magic is 0x%" PRIx64 nbd_receive_negotiate_server_flags(uint32_t globalflags) "Global flags are 0x%" PRIx32 nbd_receive_negotiate_name(const char *name) "Requesting NBD export name \"%s\""