From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53820) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gO98m-0006Ed-LL for qemu-devel@nongnu.org; Sat, 17 Nov 2018 17:32:37 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gO98l-0008CR-RC for qemu-devel@nongnu.org; Sat, 17 Nov 2018 17:32:36 -0500 From: Eric Blake Date: Sat, 17 Nov 2018 16:32:21 -0600 Message-Id: <20181117223221.2198751-1-eblake@redhat.com> In-Reply-To: <353b130c-aefb-ec4c-411b-571a79ec76e2@redhat.com> References: <353b130c-aefb-ec4c-411b-571a79ec76e2@redhat.com> Subject: [Qemu-devel] [PATCH 1.5/6] nbd/server: Ignore write errors when replying to NBD_OPT_ABORT List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: berrange@redhat.com, "open list:Network Block Dev..." Commit 37ec36f6 intentionally ignores errors when trying to reply to an NBD_OPT_ABORT request for plaintext clients, but did not make the same change for a TLS server. Since NBD_OPT_ABORT is documented as being a potential for an EPIPE when the client hangs up without waiting for our reply, we don't need to pollute the server's output with that failure. Signed-off-by: Eric Blake --- nbd/server.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/nbd/server.c b/nbd/server.c index 056cfa5ad47..dc04513de70 100644 --- a/nbd/server.c +++ b/nbd/server.c @@ -1134,12 +1134,16 @@ static int nbd_negotiate_options(NBDClient *client, uint16_t myflags, return -EINVAL; default: - ret = nbd_opt_drop(client, NBD_REP_ERR_TLS_REQD, errp, + /* Let the client keep trying, unless they asked to + * quit. Always try to give an error back to the + * client; but when replying to OPT_ABORT, be aware + * that the client may hang up before receiving the + * error, in which case we are fine ignoring the + * resulting EPIPE. */ + ret = nbd_opt_drop(client, NBD_REP_ERR_TLS_REQD, + option == NBD_OPT_ABORT ? NULL : errp, "Option 0x%" PRIx32 " not permitted before TLS", option); - /* Let the client keep trying, unless they asked to - * quit. In this mode, we've already sent an error, so - * we can't ack the abort. */ if (option == NBD_OPT_ABORT) { return 1; } -- 2.17.2