svcrdma: Hook up the logic to return ERR_CHUNK
RFC 5666 Section 4.2 states:
> When the peer detects an RPC-over-RDMA header version that it does
> not support (currently this document defines only version 1), it
> replies with an error code of ERR_VERS, and provides the low and
> high inclusive version numbers it does, in fact, support.
And:
> When other decoding errors are detected in the header or chunks,
> either an RPC decode error MAY be returned or the RPC/RDMA error
> code ERR_CHUNK MUST be returned.
The Linux NFS server does throw ERR_VERS when a client sends it
a request whose rdma_version is not "one." But it does not return
ERR_CHUNK when a header decoding error occurs. It just drops the
request.
To improve protocol extensibility, it should reject invalid values
in the rdma_proc field instead of treating them all like RDMA_MSG.
Otherwise clients can't detect when the server doesn't support
new rdma_proc values.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Devesh Sharma <devesh.sharma@broadcom.com>
Tested-by: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
index 8f68cb6..f8b840b 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
@@ -657,6 +657,8 @@
ret = svc_rdma_xdr_decode_req(rmsgp, rqstp);
if (ret < 0)
goto out_err;
+ if (ret == 0)
+ goto out_drop;
rqstp->rq_xprt_hlen = ret;
if (svc_rdma_is_backchannel_reply(xprt, rmsgp)) {
@@ -710,6 +712,8 @@
defer:
return 0;
+out_drop:
+ svc_rdma_put_context(ctxt, 1);
repost:
return svc_rdma_repost_recv(rdma_xprt, GFP_KERNEL);
}