NFSD: Add a helper to decode nfs_impl_id4

Refactor for clarity.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 08909c7..8678960 100644 (file)
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -1559,11 +1559,46 @@ nfsd4_decode_state_protect4_a(struct nfsd4_compoundargs *argp,
 }
 
 static __be32
+nfsd4_decode_nfs_impl_id4(struct nfsd4_compoundargs *argp,
+                         struct nfsd4_exchange_id *exid)
+{
+       __be32 status;
+       u32 count;
+
+       if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
+               return nfserr_bad_xdr;
+       switch (count) {
+       case 0:
+               break;
+       case 1:
+               /* Note that RFC 8881 places no length limit on
+                * nii_domain, but this implementation permits no
+                * more than NFS4_OPAQUE_LIMIT bytes */
+               status = nfsd4_decode_opaque(argp, &exid->nii_domain);
+               if (status)
+                       return status;
+               /* Note that RFC 8881 places no length limit on
+                * nii_name, but this implementation permits no
+                * more than NFS4_OPAQUE_LIMIT bytes */
+               status = nfsd4_decode_opaque(argp, &exid->nii_name);
+               if (status)
+                       return status;
+               status = nfsd4_decode_nfstime4(argp, &exid->nii_time);
+               if (status)
+                       return status;
+               break;
+       default:
+               return nfserr_bad_xdr;
+       }
+
+       return nfs_ok;
+}
+
+static __be32
 nfsd4_decode_exchange_id(struct nfsd4_compoundargs *argp,
                         struct nfsd4_exchange_id *exid)
 {
-       DECODE_HEAD;
-       int dummy;
+       __be32 status;
 
        status = nfsd4_decode_verifier4(argp, &exid->verifier);
        if (status)
@@ -1576,29 +1611,7 @@ nfsd4_decode_exchange_id(struct nfsd4_compoundargs *argp,
        status = nfsd4_decode_state_protect4_a(argp, exid);
        if (status)
                return status;
-
-       READ_BUF(4);    /* nfs_impl_id4 array length */
-       dummy = be32_to_cpup(p++);
-
-       if (dummy > 1)
-               goto xdr_error;
-
-       if (dummy == 1) {
-               status = nfsd4_decode_opaque(argp, &exid->nii_domain);
-               if (status)
-                       goto xdr_error;
-
-               /* nii_name */
-               status = nfsd4_decode_opaque(argp, &exid->nii_name);
-               if (status)
-                       goto xdr_error;
-
-               /* nii_date */
-               status = nfsd4_decode_time(argp, &exid->nii_time);
-               if (status)
-                       goto xdr_error;
-       }
-       DECODE_TAIL;
+       return nfsd4_decode_nfs_impl_id4(argp, exid);
 }
 
 static __be32