From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:59629) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1giNaR-0003XG-ES for qemu-devel@nongnu.org; Sat, 12 Jan 2019 13:00:48 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1giNYN-0001tF-4i for qemu-devel@nongnu.org; Sat, 12 Jan 2019 12:58:42 -0500 From: Eric Blake Date: Sat, 12 Jan 2019 11:58:07 -0600 Message-Id: <20190112175812.27068-15-eblake@redhat.com> In-Reply-To: <20190112175812.27068-1-eblake@redhat.com> References: <20190112175812.27068-1-eblake@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] [PATCH v3 14/19] nbd/client: Pull out oldstyle size determination List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: nsoffer@redhat.com, rjones@redhat.com, jsnow@redhat.com, vsementsov@virtuozzo.com, qemu-block@nongnu.org Another refactoring creating nbd_negotiate_finish_oldstyle() for further reuse during 'qemu-nbd --list'. Signed-off-by: Eric Blake Message-Id: <20181215135324.152629-18-eblake@redhat.com> Reviewed-by: Richard W.M. Jones --- nbd/client.c | 49 ++++++++++++++++++++++++++++++++----------------- 1 file changed, 32 insertions(+), 17 deletions(-) diff --git a/nbd/client.c b/nbd/client.c index 5053433ea5e..620fbb5ef01 100644 --- a/nbd/client.c +++ b/nbd/client.c @@ -818,7 +818,7 @@ static int nbd_negotiate_simple_meta_context(QIOChann= el *ioc, * Start the handshake to the server. After a positive return, the serv= er * 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 + * 0: server is oldstyle, must call nbd_negotiate_finish_oldsty= le * 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 @@ -923,6 +923,36 @@ static int nbd_start_negotiate(QIOChannel *ioc, QCry= ptoTLSCreds *tlscreds, } } +/* + * nbd_negotiate_finish_oldstyle: + * Populate @info with the size and export flags from an oldstyle server= , + * but does not consume 124 bytes of reserved zero padding. + * Returns 0 on success, -1 with @errp set on failure + */ +static int nbd_negotiate_finish_oldstyle(QIOChannel *ioc, NBDExportInfo = *info, + Error **errp) +{ + uint32_t oldflags; + + if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) { + error_prepend(errp, "Failed to read export length: "); + return -EINVAL; + } + info->size =3D be64_to_cpu(info->size); + + if (nbd_read(ioc, &oldflags, sizeof(oldflags), errp) < 0) { + error_prepend(errp, "Failed to read export flags: "); + return -EINVAL; + } + oldflags =3D be32_to_cpu(oldflags); + if (oldflags & ~0xffff) { + error_setg(errp, "Unexpected export flags %0x" PRIx32, oldflags)= ; + return -EINVAL; + } + info->flags =3D oldflags; + return 0; +} + /* * nbd_receive_negotiate: * Connect to server, complete negotiation, and move into transmission p= hase. @@ -936,7 +966,6 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCryptoTLS= Creds *tlscreds, int result; bool zeroes =3D true; bool base_allocation =3D info->base_allocation; - uint32_t oldflags; assert(info->name); trace_nbd_receive_negotiate_name(info->name); @@ -1009,23 +1038,9 @@ int nbd_receive_negotiate(QIOChannel *ioc, QCrypto= TLSCreds *tlscreds, error_setg(errp, "Server does not support non-empty export n= ames"); return -EINVAL; } - - if (nbd_read(ioc, &info->size, sizeof(info->size), errp) < 0) { - error_prepend(errp, "Failed to read export length: "); + if (nbd_negotiate_finish_oldstyle(ioc, info, errp) < 0) { return -EINVAL; } - info->size =3D be64_to_cpu(info->size); - - if (nbd_read(ioc, &oldflags, sizeof(oldflags), errp) < 0) { - error_prepend(errp, "Failed to read export flags: "); - return -EINVAL; - } - oldflags =3D be32_to_cpu(oldflags); - if (oldflags & ~0xffff) { - error_setg(errp, "Unexpected export flags %0x" PRIx32, oldfl= ags); - return -EINVAL; - } - info->flags =3D oldflags; break; default: return result; --=20 2.20.1