NFSD: Update the SYMLINK3args decoder to use struct xdr_stream

Similar to the WRITE decoder, code that checks the sanity of the
payload size is re-wired to work with xdr_stream infrastructure.

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

diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c
index b4071cd..eb17231 100644 (file)
--- a/fs/nfsd/nfs3xdr.c
+++ b/fs/nfsd/nfs3xdr.c
@@ -616,25 +616,28 @@ nfs3svc_decode_mkdirargs(struct svc_rqst *rqstp, __be32 *p)
 int
 nfs3svc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p)
 {
+       struct xdr_stream *xdr = &rqstp->rq_arg_stream;
        struct nfsd3_symlinkargs *args = rqstp->rq_argp;
-       char *base = (char *)p;
-       size_t dlen;
+       struct kvec *head = rqstp->rq_arg.head;
+       struct kvec *tail = rqstp->rq_arg.tail;
+       size_t remaining;
 
-       if (!(p = decode_fh(p, &args->ffh)) ||
-           !(p = decode_filename(p, &args->fname, &args->flen)))
+       if (!svcxdr_decode_diropargs3(xdr, &args->ffh, &args->fname, &args->flen))
+               return 0;
+       if (!svcxdr_decode_sattr3(rqstp, xdr, &args->attrs))
+               return 0;
+       if (xdr_stream_decode_u32(xdr, &args->tlen) < 0)
                return 0;
-       p = decode_sattr3(p, &args->attrs, nfsd_user_namespace(rqstp));
 
-       args->tlen = ntohl(*p++);
+       /* request sanity */
+       remaining = head->iov_len + rqstp->rq_arg.page_len + tail->iov_len;
+       remaining -= xdr_stream_pos(xdr);
+       if (remaining < xdr_align_size(args->tlen))
+               return 0;
 
-       args->first.iov_base = p;
-       args->first.iov_len = rqstp->rq_arg.head[0].iov_len;
-       args->first.iov_len -= (char *)p - base;
+       args->first.iov_base = xdr->p;
+       args->first.iov_len = head->iov_len - xdr_stream_pos(xdr);
 
-       dlen = args->first.iov_len + rqstp->rq_arg.page_len +
-              rqstp->rq_arg.tail[0].iov_len;
-       if (dlen < XDR_QUADLEN(args->tlen) << 2)
-               return 0;
        return 1;
 }