Commit 6bb844b4 authored by Chuck Lever's avatar Chuck Lever
Browse files

NFSD: Add an xdr_stream-based decoder for NFSv2/3 ACLs 



Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent 635a45d3

fs/nfs_common/nfsacl.c

+52 −0
Original line number Diff line number Diff line
@@ -295,3 +295,55 @@ int nfsacl_decode(struct xdr_buf *buf, unsigned int base, unsigned int *aclcnt, 
		   nfsacl_desc.desc.array_len;

}

EXPORT_SYMBOL_GPL(nfsacl_decode);



/**

 * nfs_stream_decode_acl - Decode an NFSv3 ACL

 *

 * @xdr: an xdr_stream positioned at an encoded ACL

 * @aclcnt: OUT: count of ACEs in decoded posix_acl

 * @pacl: OUT: a dynamically-allocated buffer containing the decoded posix_acl

 *

 * Return values:

 *   %false: The encoded ACL is not valid

 *   %true: @pacl contains a decoded ACL, and @xdr is advanced

 *

 * On a successful return, caller must release *pacl using posix_acl_release().

 */

bool nfs_stream_decode_acl(struct xdr_stream *xdr, unsigned int *aclcnt,

			   struct posix_acl **pacl)

{

	const size_t elem_size = XDR_UNIT * 3;

	struct nfsacl_decode_desc nfsacl_desc = {

		.desc = {

			.elem_size = elem_size,

			.xcode = pacl ? xdr_nfsace_decode : NULL,

		},

	};

	unsigned int base;

	u32 entries;



	if (xdr_stream_decode_u32(xdr, &entries) < 0)

		return false;

	if (entries > NFS_ACL_MAX_ENTRIES)

		return false;



	base = xdr_stream_pos(xdr);

	if (!xdr_inline_decode(xdr, XDR_UNIT + elem_size * entries))

		return false;

	nfsacl_desc.desc.array_maxlen = entries;

	if (xdr_decode_array2(xdr->buf, base, &nfsacl_desc.desc))

		return false;



	if (pacl) {

		if (entries != nfsacl_desc.desc.array_len ||

		    posix_acl_from_nfsacl(nfsacl_desc.acl) != 0) {

			posix_acl_release(nfsacl_desc.acl);

			return false;

		}

		*pacl = nfsacl_desc.acl;

	}

	if (aclcnt)

		*aclcnt = entries;

	return true;

}

EXPORT_SYMBOL_GPL(nfs_stream_decode_acl);

include/linux/nfsacl.h

+3 −0
Original line number Diff line number Diff line
@@ -38,5 +38,8 @@ nfsacl_encode(struct xdr_buf *buf, unsigned int base, struct inode *inode, 
extern int

nfsacl_decode(struct xdr_buf *buf, unsigned int base, unsigned int *aclcnt,

	      struct posix_acl **pacl);

extern bool

nfs_stream_decode_acl(struct xdr_stream *xdr, unsigned int *aclcnt,

		      struct posix_acl **pacl);



#endif  /* __LINUX_NFSACL_H */