1 files changed, 160 insertions, 190 deletions

diff --git a/fs/nfsd/nfsxdr.c b/fs/nfsd/nfsxdr.c
index 7aa6e8aca2c1..5d79ef6a0c7f 100644
--- a/fs/nfsd/nfsxdr.c
+++ b/fs/nfsd/nfsxdr.c
@@ -23,24 +23,31 @@ static u32	nfs_ftypes[] = {
 
 
 /*
- * XDR functions for basic NFS types
+ * Basic NFSv2 data types (RFC 1094 Section 2.3)
  */
-static __be32 *
-decode_fh(__be32 *p, struct svc_fh *fhp)
+
+/**
+ * svcxdr_decode_fhandle - Decode an NFSv2 file handle
+ * @xdr: XDR stream positioned at an encoded NFSv2 FH
+ * @fhp: OUT: filled-in server file handle
+ *
+ * Return values:
+ *  %false: The encoded file handle was not valid
+ *  %true: @fhp has been initialized
+ */
+bool
+svcxdr_decode_fhandle(struct xdr_stream *xdr, struct svc_fh *fhp)
 {
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, NFS_FHSIZE);
+	if (!p)
+		return false;
 	fh_init(fhp, NFS_FHSIZE);
 	memcpy(&fhp->fh_handle.fh_base, p, NFS_FHSIZE);
 	fhp->fh_handle.fh_size = NFS_FHSIZE;
 
-	/* FIXME: Look up export pointer here and verify
-	 * Sun Secure RPC if requested */
-	return p + (NFS_FHSIZE >> 2);
-}
-
-/* Helper function for NFSv2 ACL code */
-__be32 *nfs2svc_decode_fh(__be32 *p, struct svc_fh *fhp)
-{
-	return decode_fh(p, fhp);
+	return true;
 }
 
 static __be32 *
@@ -50,66 +57,95 @@ encode_fh(__be32 *p, struct svc_fh *fhp)
 	return p + (NFS_FHSIZE>> 2);
 }
 
-/*
- * Decode a file name and make sure that the path contains
- * no slashes or null bytes.
- */
-static __be32 *
-decode_filename(__be32 *p, char **namp, unsigned int *lenp)
+static bool
+svcxdr_decode_filename(struct xdr_stream *xdr, char **name, unsigned int *len)
 {
-	char		*name;
-	unsigned int	i;
-
-	if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXNAMLEN)) != NULL) {
-		for (i = 0, name = *namp; i < *lenp; i++, name++) {
-			if (*name == '\0' || *name == '/')
-				return NULL;
-		}
-	}
+	u32 size, i;
+	__be32 *p;
+	char *c;
+
+	if (xdr_stream_decode_u32(xdr, &size) < 0)
+		return false;
+	if (size == 0 || size > NFS_MAXNAMLEN)
+		return false;
+	p = xdr_inline_decode(xdr, size);
+	if (!p)
+		return false;
 
-	return p;
+	*len = size;
+	*name = (char *)p;
+	for (i = 0, c = *name; i < size; i++, c++)
+		if (*c == '\0' || *c == '/')
+			return false;
+
+	return true;
 }
 
-static __be32 *
-decode_sattr(__be32 *p, struct iattr *iap, struct user_namespace *userns)
+static bool
+svcxdr_decode_diropargs(struct xdr_stream *xdr, struct svc_fh *fhp,
+			char **name, unsigned int *len)
 {
-	u32	tmp, tmp1;
+	return svcxdr_decode_fhandle(xdr, fhp) &&
+		svcxdr_decode_filename(xdr, name, len);
+}
+
+static bool
+svcxdr_decode_sattr(struct svc_rqst *rqstp, struct xdr_stream *xdr,
+		    struct iattr *iap)
+{
+	u32 tmp1, tmp2;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, XDR_UNIT * 8);
+	if (!p)
+		return false;
 
 	iap->ia_valid = 0;
 
-	/* Sun client bug compatibility check: some sun clients seem to
-	 * put 0xffff in the mode field when they mean 0xffffffff.
-	 * Quoting the 4.4BSD nfs server code: Nah nah nah nah na nah.
+	/*
+	 * Some Sun clients put 0xffff in the mode field when they
+	 * mean 0xffffffff.
 	 */
-	if ((tmp = ntohl(*p++)) != (u32)-1 && tmp != 0xffff) {
+	tmp1 = be32_to_cpup(p++);
+	if (tmp1 != (u32)-1 && tmp1 != 0xffff) {
 		iap->ia_valid |= ATTR_MODE;
-		iap->ia_mode = tmp;
+		iap->ia_mode = tmp1;
 	}
-	if ((tmp = ntohl(*p++)) != (u32)-1) {
-		iap->ia_uid = make_kuid(userns, tmp);
+
+	tmp1 = be32_to_cpup(p++);
+	if (tmp1 != (u32)-1) {
+		iap->ia_uid = make_kuid(nfsd_user_namespace(rqstp), tmp1);
 		if (uid_valid(iap->ia_uid))
 			iap->ia_valid |= ATTR_UID;
 	}
-	if ((tmp = ntohl(*p++)) != (u32)-1) {
-		iap->ia_gid = make_kgid(userns, tmp);
+
+	tmp1 = be32_to_cpup(p++);
+	if (tmp1 != (u32)-1) {
+		iap->ia_gid = make_kgid(nfsd_user_namespace(rqstp), tmp1);
 		if (gid_valid(iap->ia_gid))
 			iap->ia_valid |= ATTR_GID;
 	}
-	if ((tmp = ntohl(*p++)) != (u32)-1) {
+
+	tmp1 = be32_to_cpup(p++);
+	if (tmp1 != (u32)-1) {
 		iap->ia_valid |= ATTR_SIZE;
-		iap->ia_size = tmp;
+		iap->ia_size = tmp1;
 	}
-	tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
-	if (tmp != (u32)-1 && tmp1 != (u32)-1) {
+
+	tmp1 = be32_to_cpup(p++);
+	tmp2 = be32_to_cpup(p++);
+	if (tmp1 != (u32)-1 && tmp2 != (u32)-1) {
 		iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
-		iap->ia_atime.tv_sec = tmp;
-		iap->ia_atime.tv_nsec = tmp1 * 1000; 
+		iap->ia_atime.tv_sec = tmp1;
+		iap->ia_atime.tv_nsec = tmp2 * NSEC_PER_USEC;
 	}
-	tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
-	if (tmp != (u32)-1 && tmp1 != (u32)-1) {
+
+	tmp1 = be32_to_cpup(p++);
+	tmp2 = be32_to_cpup(p++);
+	if (tmp1 != (u32)-1 && tmp2 != (u32)-1) {
 		iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
-		iap->ia_mtime.tv_sec = tmp;
-		iap->ia_mtime.tv_nsec = tmp1 * 1000; 
+		iap->ia_mtime.tv_sec = tmp1;
+		iap->ia_mtime.tv_nsec = tmp2 * NSEC_PER_USEC;
 		/*
 		 * Passing the invalid value useconds=1000000 for mtime
 		 * is a Sun convention for "set both mtime and atime to
@@ -119,10 +155,11 @@ decode_sattr(__be32 *p, struct iattr *iap, struct user_namespace *userns)
 		 * sattr in section 6.1 of "NFS Illustrated" by
 		 * Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5
 		 */
-		if (tmp1 == 1000000)
+		if (tmp2 == 1000000)
 			iap->ia_valid &= ~(ATTR_ATIME_SET|ATTR_MTIME_SET);
 	}
-	return p;
+
+	return true;
 }
 
 static __be32 *
@@ -194,225 +231,158 @@ __be32 *nfs2svc_encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *f
  */
 
 int
-nfssvc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p)
+nfssvc_decode_fhandleargs(struct svc_rqst *rqstp, __be32 *p)
 {
+	struct xdr_stream *xdr = &rqstp->rq_arg_stream;
 	struct nfsd_fhandle *args = rqstp->rq_argp;
 
-	p = decode_fh(p, &args->fh);
-	if (!p)
-		return 0;
-	return xdr_argsize_check(rqstp, p);
+	return svcxdr_decode_fhandle(xdr, &args->fh);
 }
 
 int
 nfssvc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p)
 {
+	struct xdr_stream *xdr = &rqstp->rq_arg_stream;
 	struct nfsd_sattrargs *args = rqstp->rq_argp;
 
-	p = decode_fh(p, &args->fh);
-	if (!p)
-		return 0;
-	p = decode_sattr(p, &args->attrs, nfsd_user_namespace(rqstp));
-
-	return xdr_argsize_check(rqstp, p);
+	return svcxdr_decode_fhandle(xdr, &args->fh) &&
+		svcxdr_decode_sattr(rqstp, xdr, &args->attrs);
 }
 
 int
 nfssvc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p)
 {
+	struct xdr_stream *xdr = &rqstp->rq_arg_stream;
 	struct nfsd_diropargs *args = rqstp->rq_argp;
 
-	if (!(p = decode_fh(p, &args->fh))
-	 || !(p = decode_filename(p, &args->name, &args->len)))
-		return 0;
-
-	return xdr_argsize_check(rqstp, p);
+	return svcxdr_decode_diropargs(xdr, &args->fh, &args->name, &args->len);
 }
 
 int
 nfssvc_decode_readargs(struct svc_rqst *rqstp, __be32 *p)
 {
+	struct xdr_stream *xdr = &rqstp->rq_arg_stream;
 	struct nfsd_readargs *args = rqstp->rq_argp;
-	unsigned int len;
-	int v;
-	p = decode_fh(p, &args->fh);
-	if (!p)
-		return 0;
-
-	args->offset    = ntohl(*p++);
-	len = args->count     = ntohl(*p++);
-	p++; /* totalcount - unused */
+	u32 totalcount;
 
-	len = min_t(unsigned int, len, NFSSVC_MAXBLKSIZE_V2);
+	if (!svcxdr_decode_fhandle(xdr, &args->fh))
+		return 0;
+	if (xdr_stream_decode_u32(xdr, &args->offset) < 0)
+		return 0;
+	if (xdr_stream_decode_u32(xdr, &args->count) < 0)
+		return 0;
+	/* totalcount is ignored */
+	if (xdr_stream_decode_u32(xdr, &totalcount) < 0)
+		return 0;
 
-	/* set up somewhere to store response.
-	 * We take pages, put them on reslist and include in iovec
-	 */
-	v=0;
-	while (len > 0) {
-		struct page *p = *(rqstp->rq_next_page++);
-
-		rqstp->rq_vec[v].iov_base = page_address(p);
-		rqstp->rq_vec[v].iov_len = min_t(unsigned int, len, PAGE_SIZE);
-		len -= rqstp->rq_vec[v].iov_len;
-		v++;
-	}
-	args->vlen = v;
-	return xdr_argsize_check(rqstp, p);
+	return 1;
 }
 
 int
 nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p)
 {
+	struct xdr_stream *xdr = &rqstp->rq_arg_stream;
 	struct nfsd_writeargs *args = rqstp->rq_argp;
-	unsigned int len, hdr, dlen;
 	struct kvec *head = rqstp->rq_arg.head;
+	struct kvec *tail = rqstp->rq_arg.tail;
+	u32 beginoffset, totalcount;
+	size_t remaining;
 
-	p = decode_fh(p, &args->fh);
-	if (!p)
+	if (!svcxdr_decode_fhandle(xdr, &args->fh))
 		return 0;
-
-	p++;				/* beginoffset */
-	args->offset = ntohl(*p++);	/* offset */
-	p++;				/* totalcount */
-	len = args->len = ntohl(*p++);
-	/*
-	 * The protocol specifies a maximum of 8192 bytes.
-	 */
-	if (len > NFSSVC_MAXBLKSIZE_V2)
+	/* beginoffset is ignored */
+	if (xdr_stream_decode_u32(xdr, &beginoffset) < 0)
 		return 0;
-
-	/*
-	 * Check to make sure that we got the right number of
-	 * bytes.
-	 */
-	hdr = (void*)p - head->iov_base;
-	if (hdr > head->iov_len)
+	if (xdr_stream_decode_u32(xdr, &args->offset) < 0)
+		return 0;
+	/* totalcount is ignored */
+	if (xdr_stream_decode_u32(xdr, &totalcount) < 0)
 		return 0;
-	dlen = head->iov_len + rqstp->rq_arg.page_len - hdr;
 
-	/*
-	 * Round the length of the data which was specified up to
-	 * the next multiple of XDR units and then compare that
-	 * against the length which was actually received.
-	 * Note that when RPCSEC/GSS (for example) is used, the
-	 * data buffer can be padded so dlen might be larger
-	 * than required.  It must never be smaller.
-	 */
-	if (dlen < XDR_QUADLEN(len)*4)
+	/* opaque data */
+	if (xdr_stream_decode_u32(xdr, &args->len) < 0)
 		return 0;
+	if (args->len > NFSSVC_MAXBLKSIZE_V2)
+		return 0;
+	remaining = head->iov_len + rqstp->rq_arg.page_len + tail->iov_len;
+	remaining -= xdr_stream_pos(xdr);
+	if (remaining < xdr_align_size(args->len))
+		return 0;
+	args->first.iov_base = xdr->p;
+	args->first.iov_len = head->iov_len - xdr_stream_pos(xdr);
 
-	args->first.iov_base = (void *)p;
-	args->first.iov_len = head->iov_len - hdr;
 	return 1;
 }
 
 int
 nfssvc_decode_createargs(struct svc_rqst *rqstp, __be32 *p)
 {
+	struct xdr_stream *xdr = &rqstp->rq_arg_stream;
 	struct nfsd_createargs *args = rqstp->rq_argp;
 
-	if (   !(p = decode_fh(p, &args->fh))
-	    || !(p = decode_filename(p, &args->name, &args->len)))
-		return 0;
-	p = decode_sattr(p, &args->attrs, nfsd_user_namespace(rqstp));
-
-	return xdr_argsize_check(rqstp, p);
+	return svcxdr_decode_diropargs(xdr, &args->fh,
+				       &args->name, &args->len) &&
+		svcxdr_decode_sattr(rqstp, xdr, &args->attrs);
 }
 
 int
 nfssvc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p)
 {
+	struct xdr_stream *xdr = &rqstp->rq_arg_stream;
 	struct nfsd_renameargs *args = rqstp->rq_argp;
 
-	if (!(p = decode_fh(p, &args->ffh))
-	 || !(p = decode_filename(p, &args->fname, &args->flen))
-	 || !(p = decode_fh(p, &args->tfh))
-	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
-		return 0;
-
-	return xdr_argsize_check(rqstp, p);
-}
-
-int
-nfssvc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p)
-{
-	struct nfsd_readlinkargs *args = rqstp->rq_argp;
-
-	p = decode_fh(p, &args->fh);
-	if (!p)
-		return 0;
-	args->buffer = page_address(*(rqstp->rq_next_page++));
-
-	return xdr_argsize_check(rqstp, p);
+	return svcxdr_decode_diropargs(xdr, &args->ffh,
+				       &args->fname, &args->flen) &&
+		svcxdr_decode_diropargs(xdr, &args->tfh,
+					&args->tname, &args->tlen);
 }
 
 int
 nfssvc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p)
 {
+	struct xdr_stream *xdr = &rqstp->rq_arg_stream;
 	struct nfsd_linkargs *args = rqstp->rq_argp;
 
-	if (!(p = decode_fh(p, &args->ffh))
-	 || !(p = decode_fh(p, &args->tfh))
-	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
-		return 0;
-
-	return xdr_argsize_check(rqstp, p);
+	return svcxdr_decode_fhandle(xdr, &args->ffh) &&
+		svcxdr_decode_diropargs(xdr, &args->tfh,
+					&args->tname, &args->tlen);
 }
 
 int
 nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p)
 {
+	struct xdr_stream *xdr = &rqstp->rq_arg_stream;
 	struct nfsd_symlinkargs *args = rqstp->rq_argp;
-	char *base = (char *)p;
-	size_t xdrlen;
+	struct kvec *head = rqstp->rq_arg.head;
 
-	if (   !(p = decode_fh(p, &args->ffh))
-	    || !(p = decode_filename(p, &args->fname, &args->flen)))
+	if (!svcxdr_decode_diropargs(xdr, &args->ffh, &args->fname, &args->flen))
+		return 0;
+	if (xdr_stream_decode_u32(xdr, &args->tlen) < 0)
 		return 0;
-
-	args->tlen = ntohl(*p++);
 	if (args->tlen == 0)
 		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;
-
-	/* This request is never larger than a page. Therefore,
-	 * transport will deliver either:
-	 * 1. pathname in the pagelist -> sattr is in the tail.
-	 * 2. everything in the head buffer -> sattr is in the head.
-	 */
-	if (rqstp->rq_arg.page_len) {
-		if (args->tlen != rqstp->rq_arg.page_len)
-			return 0;
-		p = rqstp->rq_arg.tail[0].iov_base;
-	} else {
-		xdrlen = XDR_QUADLEN(args->tlen);
-		if (xdrlen > args->first.iov_len - (8 * sizeof(__be32)))
-			return 0;
-		p += xdrlen;
-	}
-	decode_sattr(p, &args->attrs, nfsd_user_namespace(rqstp));
-
-	return 1;
+	args->first.iov_len = head->iov_len - xdr_stream_pos(xdr);
+	args->first.iov_base = xdr_inline_decode(xdr, args->tlen);
+	if (!args->first.iov_base)
+		return 0;
+	return svcxdr_decode_sattr(rqstp, xdr, &args->attrs);
 }
 
 int
 nfssvc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p)
 {
+	struct xdr_stream *xdr = &rqstp->rq_arg_stream;
 	struct nfsd_readdirargs *args = rqstp->rq_argp;
 
-	p = decode_fh(p, &args->fh);
-	if (!p)
+	if (!svcxdr_decode_fhandle(xdr, &args->fh))
+		return 0;
+	if (xdr_stream_decode_u32(xdr, &args->cookie) < 0)
+		return 0;
+	if (xdr_stream_decode_u32(xdr, &args->count) < 0)
 		return 0;
-	args->cookie = ntohl(*p++);
-	args->count  = ntohl(*p++);
-	args->count  = min_t(u32, args->count, PAGE_SIZE);
-	args->buffer = page_address(*(rqstp->rq_next_page++));
 
-	return xdr_argsize_check(rqstp, p);
+	return 1;
 }
 
 /*