[PATCH v1 07/10] svcrdma: Hook up the logic to return ERR_CHUNK
From: Chuck Lever <hidden>
Date: 2016-02-03 15:52:19
Also in:
linux-nfs
Subsystem:
kernel nfsd, sunrpc, and lockd servers, networking [general], nfs, sunrpc, and lockd clients, the rest · Maintainers:
Chuck Lever, Jeff Layton, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Trond Myklebust, Anna Schumaker, Linus Torvalds
Possibly related (same subject, not in this thread)
- 2016-02-05 · Re: [PATCH v1 07/10] svcrdma: Hook up the logic to return ERR_CHUNK · Devesh Sharma <hidden>
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 <redacted> --- net/sunrpc/xprtrdma/svc_rdma_marshal.c | 55 ++++++++++++++++++++++++------- net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 4 ++ 2 files changed, 46 insertions(+), 13 deletions(-)
diff --git a/net/sunrpc/xprtrdma/svc_rdma_marshal.c b/net/sunrpc/xprtrdma/svc_rdma_marshal.c
index c011b12..7df4f07 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_marshal.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_marshal.c@@ -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 -ENOSYS; + } - /* 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;
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 @@ 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 @@ out_err: 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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