Commit a0544c94 authored by Chuck Lever's avatar Chuck Lever Committed by J. Bruce Fields

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: default avatarChuck Lever <chuck.lever@oracle.com>
Reviewed-by: default avatarDevesh Sharma <devesh.sharma@broadcom.com>
Tested-by: default avatarDevesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent f3ea53fb
......@@ -148,22 +148,41 @@ static __be32 *decode_reply_array(__be32 *va, __be32 *vaend)
int svc_rdma_xdr_decode_req(struct rpcrdma_msg *rmsgp, struct svc_rqst *rqstp)
{
__be32 *va, *vaend;
unsigned int len;
u32 hdr_len;
/* Verify that there's enough bytes for header + something */
if (rqstp->rq_arg.len <= RPCRDMA_HDRLEN_MIN) {
if (rqstp->rq_arg.len <= RPCRDMA_HDRLEN_ERR) {
dprintk("svcrdma: header too short = %d\n",
rqstp->rq_arg.len);
return -EINVAL;
}
if (rmsgp->rm_vers != rpcrdma_version)
if (rmsgp->rm_vers != rpcrdma_version) {
dprintk("%s: bad version %u\n", __func__,
be32_to_cpu(rmsgp->rm_vers));
return -EPROTONOSUPPORT;
}
/* Pull in the extra for the padded case and bump our pointer */
if (rmsgp->rm_type == rdma_msgp) {
int hdrlen;
switch (be32_to_cpu(rmsgp->rm_type)) {
case RDMA_MSG:
case RDMA_NOMSG:
break;
case RDMA_DONE:
/* Just drop it */
dprintk("svcrdma: dropping RDMA_DONE message\n");
return 0;
case RDMA_ERROR:
/* Possible if this is a backchannel reply.
* XXX: We should cancel this XID, though.
*/
dprintk("svcrdma: dropping RDMA_ERROR message\n");
return 0;
case RDMA_MSGP:
/* Pull in the extra for the padded case, bump our pointer */
rmsgp->rm_body.rm_padded.rm_align =
be32_to_cpu(rmsgp->rm_body.rm_padded.rm_align);
rmsgp->rm_body.rm_padded.rm_thresh =
......@@ -171,11 +190,15 @@ int svc_rdma_xdr_decode_req(struct rpcrdma_msg *rmsgp, struct svc_rqst *rqstp)
va = &rmsgp->rm_body.rm_padded.rm_pempty[4];
rqstp->rq_arg.head[0].iov_base = va;
hdrlen = (u32)((unsigned long)va - (unsigned long)rmsgp);
rqstp->rq_arg.head[0].iov_len -= hdrlen;
if (hdrlen > rqstp->rq_arg.len)
len = (u32)((unsigned long)va - (unsigned long)rmsgp);
rqstp->rq_arg.head[0].iov_len -= len;
if (len > rqstp->rq_arg.len)
return -EINVAL;
return hdrlen;
return len;
default:
dprintk("svcrdma: bad rdma procedure (%u)\n",
be32_to_cpu(rmsgp->rm_type));
return -EINVAL;
}
/* The chunk list may contain either a read chunk list or a write
......@@ -184,14 +207,20 @@ int svc_rdma_xdr_decode_req(struct rpcrdma_msg *rmsgp, struct svc_rqst *rqstp)
va = &rmsgp->rm_body.rm_chunks[0];
vaend = (__be32 *)((unsigned long)rmsgp + rqstp->rq_arg.len);
va = decode_read_list(va, vaend);
if (!va)
if (!va) {
dprintk("svcrdma: failed to decode read list\n");
return -EINVAL;
}
va = decode_write_list(va, vaend);
if (!va)
if (!va) {
dprintk("svcrdma: failed to decode write list\n");
return -EINVAL;
}
va = decode_reply_array(va, vaend);
if (!va)
if (!va) {
dprintk("svcrdma: failed to decode reply chunk\n");
return -EINVAL;
}
rqstp->rq_arg.head[0].iov_base = va;
hdr_len = (unsigned long)va - (unsigned long)rmsgp;
......
......@@ -657,6 +657,8 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp)
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 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp)
defer:
return 0;
out_drop:
svc_rdma_put_context(ctxt, 1);
repost:
return svc_rdma_repost_recv(rdma_xprt, GFP_KERNEL);
}
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