nbd/client: Initial support for extended headers

Update the client code to be able to send an extended request, and
parse an extended header from the server.  Note that since we reject
any structured reply with a too-large payload, we can always normalize
a valid header back into the compact form, so that the caller need not
deal with two branches of a union.  Still, until a later patch lets
the client negotiate extended headers, the code added here should not
be reached.  Note that because of the different magic numbers, it is
just as easy to trace and then tolerate a non-compliant server sending
the wrong header reply as it would be to insist that the server is
compliant.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-ID: <20230925192229.3186470-21-eblake@redhat.com>
[eblake: fix trace format]
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>

1 files changed, 1 insertions, 1 deletions

diff --git a/block/nbd.c b/block/nbd.c
index 22d3cb1..7646143 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -458,7 +458,7 @@ static coroutine_fn int nbd_receive_replies(BDRVNBDState *s, uint64_t cookie,
 
         /* We are under mutex and cookie is 0. We have to do the dirty work. */
         assert(s->reply.cookie == 0);
-        ret = nbd_receive_reply(s->bs, s->ioc, &s->reply, errp);
+        ret = nbd_receive_reply(s->bs, s->ioc, &s->reply, s->info.mode, errp);
         if (ret == 0) {
             ret = -EIO;
             error_setg(errp, "server dropped connection");