From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50883) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1evZit-0001dD-OF for qemu-devel@nongnu.org; Mon, 12 Mar 2018 22:31:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1evZis-0007Dk-KC for qemu-devel@nongnu.org; Mon, 12 Mar 2018 22:31:31 -0400 References: <20180312152126.286890-1-vsementsov@virtuozzo.com> <20180312152126.286890-3-vsementsov@virtuozzo.com> From: Eric Blake Message-ID: <3000907b-888d-2164-df16-1ac54acafba5@redhat.com> Date: Mon, 12 Mar 2018 21:31:15 -0500 MIME-Version: 1.0 In-Reply-To: <20180312152126.286890-3-vsementsov@virtuozzo.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v2 2/8] nbd/server: add nbd_read_opt_name helper List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Vladimir Sementsov-Ogievskiy , qemu-devel@nongnu.org, qemu-block@nongnu.org Cc: mreitz@redhat.com, kwolf@redhat.com, pbonzini@redhat.com, den@openvz.org On 03/12/2018 10:21 AM, Vladimir Sementsov-Ogievskiy wrote: > Add helper to read name in format: > > uint32 len (<= NBD_MAX_NAME_SIZE) > len bytes string (not 0-terminated) > > The helper would be reused in following patch. s/would/will/ > > Signed-off-by: Vladimir Sementsov-Ogievskiy > --- > > v2: splitted and changed a lot helper from larger patch of v1 'split' (one of those weird English words whose past and present tense are spelled the same way; there is no 'splitted') > > nbd/server.c | 55 ++++++++++++++++++++++++++++++++++++++++++------------- > 1 file changed, 42 insertions(+), 13 deletions(-) > > diff --git a/nbd/server.c b/nbd/server.c > index d163964cf9..085e14afbf 100644 > --- a/nbd/server.c > +++ b/nbd/server.c > @@ -273,6 +273,47 @@ static int nbd_opt_read(NBDClient *client, void *buffer, size_t size, > return qio_channel_read_all(client->ioc, buffer, size, errp) < 0 ? -EIO : 1; > } > > +/* nbd_opt_read_name > + * > + * Read string in format: Read a string in the format: > + * uint32_t len (<= NBD_MAX_NAME_SIZE) > + * len bytes string (not 0-terminated) > + * > + * @name should be enough to store NBD_MAX_NAME_SIZE+1. > + * if @length is non-zero, it would be set to read string length. s/if/If/ s/would/will/ s/read/the actual/ > + * > + * Return -errno on I/O error, 0 if option was completely handled by > + * sending a reply about inconsistent lengths, or 1 on success. */ > +static int nbd_opt_read_name(NBDClient *client, char *name, uint32_t *length, > + Error **errp) > +{ Function looks good. > @@ -455,19 +496,7 @@ static int nbd_negotiate_handle_info(NBDClient *client, uint16_t myflags, > 2 bytes: N, number of requests (can be 0) > N * 2 bytes: N requests > */ > - rc = nbd_opt_read(client, &namelen, sizeof(namelen), errp); > - if (rc <= 0) { > - return rc; > - } > - be32_to_cpus(&namelen); > - if (namelen >= sizeof(name)) { > - return nbd_opt_invalid(client, errp, "name too long for qemu"); > - } > - rc = nbd_opt_read(client, name, namelen, errp); > - if (rc <= 0) { > - return rc; > - } > - name[namelen] = '\0'; > + rc = nbd_opt_read_name(client, name, &namelen, errp); > trace_nbd_negotiate_handle_export_name_request(name); > > rc = nbd_opt_read(client, &requests, sizeof(requests), errp); Oh, so close. You overwrote rc instead of checking for errors. I'm squashing in the obvious fix, plus the grammar changes, then adding: Reviewed-by: Eric Blake diff --git i/nbd/server.c w/nbd/server.c index 850c6cd2dad..e28526600c4 100644 --- i/nbd/server.c +++ w/nbd/server.c @@ -497,6 +497,9 @@ static int nbd_negotiate_handle_info(NBDClient *client, uint16_t myflags, N * 2 bytes: N requests */ rc = nbd_opt_read_name(client, name, &namelen, errp); + if (rc <= 0) { + return rc; + } trace_nbd_negotiate_handle_export_name_request(name); rc = nbd_opt_read(client, &requests, sizeof(requests), errp); -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org