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authorDaniel P. Berrange <berrange@redhat.com>2016-02-10 18:41:06 +0000
committerPaolo Bonzini <pbonzini@redhat.com>2016-02-16 17:14:24 +0100
commit26afa868dbd8641070c0a8d851b082b603c04fa1 (patch)
treeaf567dd067938490c0c153465dda08ba947230d6 /nbd
parentf72d705f0de9ec49248e72cf888624994f09eda2 (diff)
nbd: make server compliant with fixed newstyle spec
If the client does not request the fixed new style protocol, then we should only accept NBD_OPT_EXPORT_NAME. All other options are only valid when fixed new style has been activated. The qemu-nbd client doesn't currently request fixed new style protocol, but this change won't break qemu-nbd, because it fortunately only ever uses NBD_OPT_EXPORT_NAME, so was never triggering the non-compliant server behaviour. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> Message-Id: <1455129674-17255-9-git-send-email-berrange@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'nbd')
-rw-r--r--nbd/server.c69
1 files changed, 46 insertions, 23 deletions
diff --git a/nbd/server.c b/nbd/server.c
index 15aa03da95..074a1e6d7d 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -310,6 +310,7 @@ fail:
static int nbd_negotiate_options(NBDClient *client)
{
uint32_t flags;
+ bool fixedNewstyle = false;
/* Client sends:
[ 0 .. 3] client flags
@@ -332,14 +333,19 @@ static int nbd_negotiate_options(NBDClient *client)
}
TRACE("Checking client flags");
be32_to_cpus(&flags);
- if (flags != 0 && flags != NBD_FLAG_C_FIXED_NEWSTYLE) {
- LOG("Bad client flags received");
+ if (flags & NBD_FLAG_C_FIXED_NEWSTYLE) {
+ TRACE("Support supports fixed newstyle handshake");
+ fixedNewstyle = true;
+ flags &= ~NBD_FLAG_C_FIXED_NEWSTYLE;
+ }
+ if (flags != 0) {
+ TRACE("Unknown client flags 0x%x received", flags);
return -EIO;
}
while (1) {
int ret;
- uint32_t tmp, length;
+ uint32_t clientflags, length;
uint64_t magic;
if (nbd_negotiate_read(client->ioc, &magic, sizeof(magic)) !=
@@ -353,10 +359,12 @@ static int nbd_negotiate_options(NBDClient *client)
return -EINVAL;
}
- if (nbd_negotiate_read(client->ioc, &tmp, sizeof(tmp)) != sizeof(tmp)) {
+ if (nbd_negotiate_read(client->ioc, &clientflags,
+ sizeof(clientflags)) != sizeof(clientflags)) {
LOG("read failed");
return -EINVAL;
}
+ clientflags = be32_to_cpu(clientflags);
if (nbd_negotiate_read(client->ioc, &length, sizeof(length)) !=
sizeof(length)) {
@@ -365,26 +373,41 @@ static int nbd_negotiate_options(NBDClient *client)
}
length = be32_to_cpu(length);
- TRACE("Checking option");
- switch (be32_to_cpu(tmp)) {
- case NBD_OPT_LIST:
- ret = nbd_negotiate_handle_list(client, length);
- if (ret < 0) {
- return ret;
+ TRACE("Checking option 0x%x", clientflags);
+ if (fixedNewstyle) {
+ switch (clientflags) {
+ case NBD_OPT_LIST:
+ ret = nbd_negotiate_handle_list(client, length);
+ if (ret < 0) {
+ return ret;
+ }
+ break;
+
+ case NBD_OPT_ABORT:
+ return -EINVAL;
+
+ case NBD_OPT_EXPORT_NAME:
+ return nbd_negotiate_handle_export_name(client, length);
+
+ default:
+ TRACE("Unsupported option 0x%x", clientflags);
+ nbd_negotiate_send_rep(client->ioc, NBD_REP_ERR_UNSUP,
+ clientflags);
+ return -EINVAL;
+ }
+ } else {
+ /*
+ * If broken new-style we should drop the connection
+ * for anything except NBD_OPT_EXPORT_NAME
+ */
+ switch (clientflags) {
+ case NBD_OPT_EXPORT_NAME:
+ return nbd_negotiate_handle_export_name(client, length);
+
+ default:
+ TRACE("Unsupported option 0x%x", clientflags);
+ return -EINVAL;
}
- break;
-
- case NBD_OPT_ABORT:
- return -EINVAL;
-
- case NBD_OPT_EXPORT_NAME:
- return nbd_negotiate_handle_export_name(client, length);
-
- default:
- tmp = be32_to_cpu(tmp);
- LOG("Unsupported option 0x%x", tmp);
- nbd_negotiate_send_rep(client->ioc, NBD_REP_ERR_UNSUP, tmp);
- return -EINVAL;
}
}
}