From e2a9d9a39d55fc3a0df387df05497b4b47d2dd83 Mon Sep 17 00:00:00 2001 From: "Daniel P. Berrange" Date: Wed, 10 Feb 2016 18:41:07 +0000 Subject: [PATCH] nbd: make client request fixed new style if advertised If the server advertises support for the fixed new style negotiation, the client should in turn enable new style. This will allow the client to negotiate further NBD options besides the export name. Signed-off-by: Daniel P. Berrange Message-Id: <1455129674-17255-10-git-send-email-berrange@redhat.com> Signed-off-by: Paolo Bonzini --- nbd/client.c | 27 +++++++++++++++++---------- 1 file changed, 17 insertions(+), 10 deletions(-) diff --git a/nbd/client.c b/nbd/client.c index 5064788bb1..88f2adab0d 100644 --- a/nbd/client.c +++ b/nbd/client.c @@ -76,7 +76,6 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint32_t *flags, { char buf[256]; uint64_t magic, s; - uint16_t tmp; int rc; TRACE("Receiving negotiation."); @@ -117,19 +116,26 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint32_t *flags, TRACE("Magic is 0x%" PRIx64, magic); if (magic == NBD_OPTS_MAGIC) { - uint32_t reserved = 0; + uint32_t clientflags = 0; uint32_t opt; uint32_t namesize; + uint16_t globalflags; + uint16_t exportflags; - if (read_sync(ioc, &tmp, sizeof(tmp)) != sizeof(tmp)) { + if (read_sync(ioc, &globalflags, sizeof(globalflags)) != + sizeof(globalflags)) { error_setg(errp, "Failed to read server flags"); goto fail; } - *flags = be16_to_cpu(tmp) << 16; - /* reserved for future use */ - if (write_sync(ioc, &reserved, sizeof(reserved)) != - sizeof(reserved)) { - error_setg(errp, "Failed to read reserved field"); + *flags = be16_to_cpu(globalflags) << 16; + if (globalflags & NBD_FLAG_FIXED_NEWSTYLE) { + TRACE("Server supports fixed new style"); + clientflags |= NBD_FLAG_C_FIXED_NEWSTYLE; + } + /* client requested flags */ + if (write_sync(ioc, &clientflags, sizeof(clientflags)) != + sizeof(clientflags)) { + error_setg(errp, "Failed to send clientflags field"); goto fail; } /* write the export name */ @@ -165,11 +171,12 @@ int nbd_receive_negotiate(QIOChannel *ioc, const char *name, uint32_t *flags, *size = be64_to_cpu(s); TRACE("Size is %" PRIu64, *size); - if (read_sync(ioc, &tmp, sizeof(tmp)) != sizeof(tmp)) { + if (read_sync(ioc, &exportflags, sizeof(exportflags)) != + sizeof(exportflags)) { error_setg(errp, "Failed to read export flags"); goto fail; } - *flags |= be16_to_cpu(tmp); + *flags |= be16_to_cpu(exportflags); } else if (magic == NBD_CLIENT_MAGIC) { if (name) { error_setg(errp, "Server does not support export names"); -- 2.11.4.GIT