nfsd41: access_valid

For nfs41, the open share flags are used also for
delegation "wants" and "signals".  Check that they are valid.
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

fs/nfsd/nfs4proc.c

@@ -910,6 +910,7 @@ nfsd4_proc_compound(struct svc_rqst *rqstp,
 	resp->tag = args->tag;
 	resp->opcnt = 0;
 	resp->rqstp = rqstp;
+	resp->cstate.minorversion = args->minorversion;
 	resp->cstate.replay_owner = NULL;
 	fh_init(&resp->cstate.current_fh, NFS4_FHSIZE);
 	fh_init(&resp->cstate.save_fh, NFS4_FHSIZE);

fs/nfsd/nfs4state.c

@@ -1943,11 +1943,21 @@ find_file(struct inode *ino)
 	return NULL;
 }
 
-static inline int access_valid(u32 x)
+static inline int access_valid(u32 x, u32 minorversion)
 {
-	if (x < NFS4_SHARE_ACCESS_READ)
+	if ((x & NFS4_SHARE_ACCESS_MASK) < NFS4_SHARE_ACCESS_READ)
 		return 0;
-	if (x > NFS4_SHARE_ACCESS_BOTH)
+	if ((x & NFS4_SHARE_ACCESS_MASK) > NFS4_SHARE_ACCESS_BOTH)
+		return 0;
+	x &= ~NFS4_SHARE_ACCESS_MASK;
+	if (minorversion && x) {
+		if ((x & NFS4_SHARE_WANT_MASK) > NFS4_SHARE_WANT_CANCEL)
+			return 0;
+		if ((x & NFS4_SHARE_WHEN_MASK) > NFS4_SHARE_PUSH_DELEG_WHEN_UNCONTENDED)
+			return 0;
+		x &= ~(NFS4_SHARE_WANT_MASK | NFS4_SHARE_WHEN_MASK);
+	}
+	if (x)
 		return 0;
 	return 1;
 }
@@ -2495,7 +2505,7 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf
 	__be32 status;
 
 	status = nfserr_inval;
-	if (!access_valid(open->op_share_access)
+	if (!access_valid(open->op_share_access, resp->cstate.minorversion)
 			|| !deny_valid(open->op_share_deny))
 		goto out;
 	/*
@@ -3104,7 +3114,7 @@ nfsd4_open_downgrade(struct svc_rqst *rqstp,
 			(int)cstate->current_fh.fh_dentry->d_name.len,
 			cstate->current_fh.fh_dentry->d_name.name);
 
-	if (!access_valid(od->od_share_access)
+	if (!access_valid(od->od_share_access, cstate->minorversion)
 			|| !deny_valid(od->od_share_deny))
 		return nfserr_inval;
 

include/linux/nfsd/xdr4.h

@@ -53,6 +53,7 @@ struct nfsd4_compound_state {
 	struct nfsd4_slot	*slot;
 	__be32			*statp;
 	size_t			iovlen;
+	u32			minorversion;
 	u32			status;
 };