From patchwork Fri Apr 24 11:04:14 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?q?Andreas_Gr=C3=BCnbacher?= X-Patchwork-Id: 6268401 Return-Path: X-Original-To: patchwork-linux-nfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 2C6969F1C4 for ; Fri, 24 Apr 2015 11:14:58 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 2245A20225 for ; Fri, 24 Apr 2015 11:14:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EE229201E4 for ; Fri, 24 Apr 2015 11:14:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932190AbbDXLFU (ORCPT ); Fri, 24 Apr 2015 07:05:20 -0400 Received: from mail-wi0-f175.google.com ([209.85.212.175]:35962 "EHLO mail-wi0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932263AbbDXLFP (ORCPT ); Fri, 24 Apr 2015 07:05:15 -0400 Received: by wizk4 with SMTP id k4so17545547wiz.1; Fri, 24 Apr 2015 04:05:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:subject:date:message-id:in-reply-to:references:in-reply-to :references; bh=aNjARS/uu8BGAbIpIrBOWJwJ16r67mvHu3v2Hd3H0ew=; b=vXqViKSmy3z8WxvyiAcwjzUexXZ3gH6lLcIv8WUkB6eEj0Bdc8pbjpyVUZQS5wMymK 4C/dtynUEk5yNF2gdoPLZO75Fexp20FGl15IST/EkjtZTh9AfBtYHVcvFCE4PqZpXl0G ANseXgjibDi4vGBOldESyjeYXCCFX2fiAmv9+kZidq1WiIymibHtkC9pJ9lC5HcVCK07 ZszhOxTC80F/JGuNVscShFdjIX/jsQzwp7F47Z1okSxf2zOWd08AmwLhGRHIeIyOOoXi N4UupITMEx/YKc905SlKxbNfzS9+eQeJNKgi581E7SAkl6G5UTk43d8IULnvVv3FY+a8 O7Kw== X-Received: by 10.180.93.7 with SMTP id cq7mr2943889wib.24.1429873513719; Fri, 24 Apr 2015 04:05:13 -0700 (PDT) Received: from nuc.home.com (80-110-112-232.cgn.dynamic.surfer.at. [80.110.112.232]) by mx.google.com with ESMTPSA id ch6sm16410648wjc.3.2015.04.24.04.05.12 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 24 Apr 2015 04:05:13 -0700 (PDT) From: Andreas Gruenbacher X-Google-Original-From: Andreas Gruenbacher To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org Subject: [RFC v3 17/45] richacl: Create-time inheritance Date: Fri, 24 Apr 2015 13:04:14 +0200 Message-Id: X-Mailer: git-send-email 2.1.0 In-Reply-To: References: In-Reply-To: References: Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Spam-Status: No, score=-6.8 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_HI, T_DKIM_INVALID, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When a new file is created, it can inherit an acl from its parent directory; this is similar to how default acls work in POSIX (draft) ACLs. As with POSIX ACLs, if a file inherits an acl from its parent directory, the intersection between the create mode and the permissions granted by the inherited acl determines the file masks and file permission bits, and the umask is ignored. Signed-off-by: Andreas Gruenbacher --- fs/richacl_base.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++++ fs/richacl_inode.c | 60 ++++++++++++++++++++++++++++++++++++++++++ include/linux/richacl.h | 2 ++ 3 files changed, 131 insertions(+) diff --git a/fs/richacl_base.c b/fs/richacl_base.c index 5273ccb..5d45539 100644 --- a/fs/richacl_base.c +++ b/fs/richacl_base.c @@ -368,3 +368,72 @@ richacl_chmod(struct richacl *acl, mode_t mode) return clone; } EXPORT_SYMBOL_GPL(richacl_chmod); + +/** + * richacl_inherit - compute the inherited acl of a new file + * @dir_acl: acl of the containing directory + * @isdir: inherit by a directory or non-directory? + * + * A directory can have acl entries which files and/or directories created + * inside the directory will inherit. This function computes the acl for such + * a new file. If there is no inheritable acl, it will return %NULL. + */ +struct richacl * +richacl_inherit(const struct richacl *dir_acl, int isdir) +{ + const struct richace *dir_ace; + struct richacl *acl = NULL; + struct richace *ace; + int count = 0; + + if (isdir) { + richacl_for_each_entry(dir_ace, dir_acl) { + if (!richace_is_inheritable(dir_ace)) + continue; + count++; + } + if (!count) + return NULL; + acl = richacl_alloc(count, GFP_KERNEL); + if (!acl) + return ERR_PTR(-ENOMEM); + ace = acl->a_entries; + richacl_for_each_entry(dir_ace, dir_acl) { + if (!richace_is_inheritable(dir_ace)) + continue; + memcpy(ace, dir_ace, sizeof(struct richace)); + if (dir_ace->e_flags & RICHACE_NO_PROPAGATE_INHERIT_ACE) + richace_clear_inheritance_flags(ace); + if ((dir_ace->e_flags & RICHACE_FILE_INHERIT_ACE) && + !(dir_ace->e_flags & RICHACE_DIRECTORY_INHERIT_ACE)) + ace->e_flags |= RICHACE_INHERIT_ONLY_ACE; + ace++; + } + } else { + richacl_for_each_entry(dir_ace, dir_acl) { + if (!(dir_ace->e_flags & RICHACE_FILE_INHERIT_ACE)) + continue; + count++; + } + if (!count) + return NULL; + acl = richacl_alloc(count, GFP_KERNEL); + if (!acl) + return ERR_PTR(-ENOMEM); + ace = acl->a_entries; + richacl_for_each_entry(dir_ace, dir_acl) { + if (!(dir_ace->e_flags & RICHACE_FILE_INHERIT_ACE)) + continue; + memcpy(ace, dir_ace, sizeof(struct richace)); + richace_clear_inheritance_flags(ace); + /* + * RICHACE_DELETE_CHILD is meaningless for + * non-directories, so clear it. + */ + ace->e_mask &= ~RICHACE_DELETE_CHILD; + ace++; + } + } + + return acl; +} diff --git a/fs/richacl_inode.c b/fs/richacl_inode.c index b421f68..1a5b868 100644 --- a/fs/richacl_inode.c +++ b/fs/richacl_inode.c @@ -201,3 +201,63 @@ is_everyone: return denied ? -EACCES : 0; } EXPORT_SYMBOL_GPL(richacl_permission); + +/** + * richacl_inherit_inode - compute inherited acl and file mode + * @dir_acl: acl of the containing directory + * @inode: inode of the new file (create mode in i_mode) + * + * The file permission bits in inode->i_mode must be set to the create mode by + * the caller. + * + * If there is an inheritable acl, the maximum permissions that the acl grants + * will be computed and permissions not granted by the acl will be removed from + * inode->i_mode. If there is no inheritable acl, the umask will be applied + * instead. + */ +static struct richacl * +richacl_inherit_inode(const struct richacl *dir_acl, struct inode *inode) +{ + struct richacl *acl; + mode_t mask; + + acl = richacl_inherit(dir_acl, S_ISDIR(inode->i_mode)); + if (acl) { + + richacl_compute_max_masks(acl); + + /* + * Ensure that the acl will not grant any permissions beyond + * the create mode. + */ + acl->a_flags |= RICHACL_MASKED; + acl->a_owner_mask &= richacl_mode_to_mask(inode->i_mode >> 6) | + RICHACE_POSIX_OWNER_ALLOWED; + acl->a_group_mask &= richacl_mode_to_mask(inode->i_mode >> 3); + acl->a_other_mask &= richacl_mode_to_mask(inode->i_mode); + mask = ~S_IRWXUGO | richacl_masks_to_mode(acl); + } else + mask = ~current_umask(); + + inode->i_mode &= mask; + return acl; +} + +struct richacl *richacl_create(struct inode *inode, struct inode *dir) +{ + struct richacl *dir_acl, *acl = NULL; + + if (S_ISLNK(inode->i_mode)) + return NULL; + dir_acl = get_richacl(dir); + if (dir_acl) { + if (IS_ERR(dir_acl)) + return dir_acl; + acl = richacl_inherit_inode(dir_acl, inode); + richacl_put(dir_acl); + } + if (!acl) + inode->i_mode &= ~current_umask(); + return acl; +} +EXPORT_SYMBOL_GPL(richacl_create); diff --git a/include/linux/richacl.h b/include/linux/richacl.h index 6d88ee9..ab9fde1 100644 --- a/include/linux/richacl.h +++ b/include/linux/richacl.h @@ -296,8 +296,10 @@ extern unsigned int richacl_mode_to_mask(mode_t); extern unsigned int richacl_want_to_mask(unsigned int); extern void richacl_compute_max_masks(struct richacl *); extern struct richacl *richacl_chmod(struct richacl *, mode_t); +extern struct richacl *richacl_inherit(const struct richacl *, int); /* richacl_inode.c */ extern int richacl_permission(struct inode *, const struct richacl *, int); +extern struct richacl *richacl_create(struct inode *, struct inode *); #endif /* __RICHACL_H */