From patchwork Mon Mar 1 15:18:43 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chuck Lever X-Patchwork-Id: 12110029 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B5E24C433E0 for ; Mon, 1 Mar 2021 15:19:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8957864E2E for ; Mon, 1 Mar 2021 15:19:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237157AbhCAPTP (ORCPT ); Mon, 1 Mar 2021 10:19:15 -0500 Received: from mail.kernel.org ([198.145.29.99]:41146 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237156AbhCAPS7 (ORCPT ); Mon, 1 Mar 2021 10:18:59 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2580264DF5 for ; Mon, 1 Mar 2021 15:18:44 +0000 (UTC) Subject: [PATCH v1 34/42] NFSD: Add an xdr_stream-based encoder for NFSv2/3 ACLs From: Chuck Lever To: linux-nfs@vger.kernel.org Date: Mon, 01 Mar 2021 10:18:43 -0500 Message-ID: <161461192343.8508.18061557905904664325.stgit@klimt.1015granger.net> In-Reply-To: <161461145466.8508.13379815439337754427.stgit@klimt.1015granger.net> References: <161461145466.8508.13379815439337754427.stgit@klimt.1015granger.net> User-Agent: StGit/1.0-5-g755c MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org Signed-off-by: Chuck Lever --- fs/nfs_common/nfsacl.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/nfsacl.h | 3 ++ 2 files changed, 74 insertions(+) diff --git a/fs/nfs_common/nfsacl.c b/fs/nfs_common/nfsacl.c index 79c563c1a5e8..5a5bd85d08f8 100644 --- a/fs/nfs_common/nfsacl.c +++ b/fs/nfs_common/nfsacl.c @@ -136,6 +136,77 @@ int nfsacl_encode(struct xdr_buf *buf, unsigned int base, struct inode *inode, } EXPORT_SYMBOL_GPL(nfsacl_encode); +/** + * nfs_stream_encode_acl - Encode an NFSv3 ACL + * + * @xdr: an xdr_stream positioned to receive an encoded ACL + * @inode: inode of file whose ACL this is + * @acl: posix_acl to encode + * @encode_entries: whether to encode ACEs as well + * @typeflag: ACL type: NFS_ACL_DEFAULT or zero + * + * Return values: + * %false: The ACL could not be encoded + * %true: @xdr is advanced to the next available position + */ +bool nfs_stream_encode_acl(struct xdr_stream *xdr, struct inode *inode, + struct posix_acl *acl, int encode_entries, + int typeflag) +{ + const size_t elem_size = XDR_UNIT * 3; + u32 entries = (acl && acl->a_count) ? max_t(int, acl->a_count, 4) : 0; + struct nfsacl_encode_desc nfsacl_desc = { + .desc = { + .elem_size = elem_size, + .array_len = encode_entries ? entries : 0, + .xcode = xdr_nfsace_encode, + }, + .acl = acl, + .typeflag = typeflag, + .uid = inode->i_uid, + .gid = inode->i_gid, + }; + struct nfsacl_simple_acl aclbuf; + unsigned int base; + int err; + + if (entries > NFS_ACL_MAX_ENTRIES) + return false; + if (xdr_stream_encode_u32(xdr, entries) < 0) + return false; + + if (encode_entries && acl && acl->a_count == 3) { + struct posix_acl *acl2 = &aclbuf.acl; + + /* Avoid the use of posix_acl_alloc(). nfsacl_encode() is + * invoked in contexts where a memory allocation failure is + * fatal. Fortunately this fake ACL is small enough to + * construct on the stack. */ + posix_acl_init(acl2, 4); + + /* Insert entries in canonical order: other orders seem + to confuse Solaris VxFS. */ + acl2->a_entries[0] = acl->a_entries[0]; /* ACL_USER_OBJ */ + acl2->a_entries[1] = acl->a_entries[1]; /* ACL_GROUP_OBJ */ + acl2->a_entries[2] = acl->a_entries[1]; /* ACL_MASK */ + acl2->a_entries[2].e_tag = ACL_MASK; + acl2->a_entries[3] = acl->a_entries[2]; /* ACL_OTHER */ + nfsacl_desc.acl = acl2; + } + + base = xdr_stream_pos(xdr); + if (!xdr_reserve_space(xdr, XDR_UNIT + + elem_size * nfsacl_desc.desc.array_len)) + return false; + err = xdr_encode_array2(xdr->buf, base, &nfsacl_desc.desc); + if (err) + return false; + + return true; +} +EXPORT_SYMBOL_GPL(nfs_stream_encode_acl); + + struct nfsacl_decode_desc { struct xdr_array2_desc desc; unsigned int count; diff --git a/include/linux/nfsacl.h b/include/linux/nfsacl.h index 0ba99c513649..8e76a79cdc6a 100644 --- a/include/linux/nfsacl.h +++ b/include/linux/nfsacl.h @@ -41,5 +41,8 @@ nfsacl_decode(struct xdr_buf *buf, unsigned int base, unsigned int *aclcnt, extern bool nfs_stream_decode_acl(struct xdr_stream *xdr, unsigned int *aclcnt, struct posix_acl **pacl); +extern bool +nfs_stream_encode_acl(struct xdr_stream *xdr, struct inode *inode, + struct posix_acl *acl, int encode_entries, int typeflag); #endif /* __LINUX_NFSACL_H */