20.10.2017 01:26, Eric Blake wrote:
From: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
Minimal implementation of structured read: one structured reply chunk,
no segmentation.
Minimal structured error implementation: no text message.
Support DF flag, but just ignore it, as there is no segmentation any
way.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
Signed-off-by: Eric Blake <ebl...@redhat.com>
---
v5: correct DF flag spelling, include errname in trace, handle any bogus
payload from option
v4: better _DF flag handling, convert errno to wire format, add
comments and tracing, rework structured error for less churn when adding
text message later, don't kill connection on redundant client option
---
nbd/server.c | 106 +++++++++++++++++++++++++++++++++++++++++++++++++------
nbd/trace-events | 2 ++
2 files changed, 98 insertions(+), 10 deletions(-)
diff --git a/nbd/server.c b/nbd/server.c
index b3f7e0b18e..9be93c4a52 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -100,6 +100,8 @@ struct NBDClient {
QTAILQ_ENTRY(NBDClient) next;
int nb_requests;
bool closing;
+
+ bool structured_reply;
};
/* That's all folks */
@@ -754,6 +756,22 @@ static int nbd_negotiate_options(NBDClient *client,
uint16_t myflags,
"TLS not configured");
}
break;
+
+ case NBD_OPT_STRUCTURED_REPLY:
+ if (length) {
+ ret = nbd_check_zero_length(client, length, option, errp);
here same thing like in previous patch, about success in
nbd_check_zero_length
+ } else if (client->structured_reply) {
+ ret = nbd_negotiate_send_rep_err(
+ client->ioc, NBD_REP_ERR_INVALID, option, errp,
+ "structured reply already negotiated");
+ } else {
+ ret = nbd_negotiate_send_rep(client->ioc, NBD_REP_ACK,
+ option, errp);
+ }
you've dropped "if (ret < 0) { return ret }", but the following two
lines should not be
executed if ret < 0.. May be it doesn't matter (we will abort connection
anyway after switch {}) but
it looks strange.
+ client->structured_reply = true;
+ myflags |= NBD_FLAG_SEND_DF;
+ break;
+
default:
if (nbd_drop(client->ioc, length, errp) < 0) {
return -EIO;
@@ -1228,6 +1246,60 @@ static int nbd_co_send_simple_reply(NBDClient *client,
return nbd_co_send_iov(client, iov, len ? 2 : 1, errp);
}
[...]
--
Best regards,
Vladimir
