From patchwork Tue Aug 4 11:53:19 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: 6937631 Return-Path: X-Original-To: patchwork-cifs-client@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id DA8CAC05AD for ; Tue, 4 Aug 2015 12:04:51 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id F13CD20481 for ; Tue, 4 Aug 2015 12:04:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0CAC72039E for ; Tue, 4 Aug 2015 12:04:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933686AbbHDLzR (ORCPT ); Tue, 4 Aug 2015 07:55:17 -0400 Received: from mail-wi0-f175.google.com ([209.85.212.175]:36830 "EHLO mail-wi0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933484AbbHDLzQ (ORCPT ); Tue, 4 Aug 2015 07:55:16 -0400 Received: by wicgj17 with SMTP id gj17so146763639wic.1; Tue, 04 Aug 2015 04:55:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=3PLT8T/CVGZjsX2DPdC/cgvS/ulCZK1bwrHS4txwodc=; b=WOgCCDUMBNL/KOSv5YOqce+olcxqU2VCYP3dM9ABGRJofRqtrB5kbTb5wNiRofi5Bg PEpHW6rt4f9n7tR9Z2Cx5sUN162W0XdEdkQwRGaxlZXh6aq9PiOE19Cm4QiXlJp7KHYQ LjY4seWtJRPz6uvFsRRUfAwGx4kEqcEbsLPEtRBwyhVjiZKc04kuCL8rjUNgGRHxwsi0 QltIwhr9a1km0TN/6en2pSTtXZY1Xi6RJ7BtXafYTlrAodNAlDUAciZzFGkMLTx3gLRE wMGSFRb9PcnYQJ8YsYa8qHA3R5EYQLjD6tonS3NYNzdnQhv08/0zURg3tDYeX1MzLu+n ym0Q== X-Received: by 10.194.110.100 with SMTP id hz4mr7359448wjb.6.1438689314240; Tue, 04 Aug 2015 04:55:14 -0700 (PDT) Received: from schleppi.home.com (p54980F84.dip0.t-ipconnect.de. [84.152.15.132]) by smtp.gmail.com with ESMTPSA id u7sm2018458wif.3.2015.08.04.04.55.12 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 04 Aug 2015 04:55:13 -0700 (PDT) From: Andreas Gruenbacher X-Google-Original-From: Andreas Gruenbacher To: linux-kernel@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-api@vger.kernel.org, linux-cifs@vger.kernel.org, linux-security-module@vger.kernel.org, Andreas Gruenbacher , Andreas Gruenbacher Subject: [RFC v6 21/40] richacl: Move everyone@ aces down the acl Date: Tue, 4 Aug 2015 13:53:19 +0200 Message-Id: <1438689218-6921-22-git-send-email-agruenba@redhat.com> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1438689218-6921-1-git-send-email-agruenba@redhat.com> References: <1438689218-6921-1-git-send-email-agruenba@redhat.com> Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, T_DKIM_INVALID, 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 The POSIX standard puts processes which are not the owner or a member in the owning group or which match any ace other then everyone@ on the other file class. We only know if a process is in the other class after processing the entire acl. Move all everyone@ aces in the acl down in the acl so that at most a single everyone@ allow ace remains at the end. Permissions which are not explicitly allowed are implicitly denied, so an everyone@ deny ace is unneeded. The everyone@ aces can be moved down the acl without changing the permissions that the acl grants. This transformation simplifies the following algorithms, and eventually allows us to turn the final everyone@ allow ace into an entry for the other class. Signed-off-by: Andreas Gruenbacher --- fs/richacl_compat.c | 65 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) diff --git a/fs/richacl_compat.c b/fs/richacl_compat.c index 6ea3f57..5295c1c 100644 --- a/fs/richacl_compat.c +++ b/fs/richacl_compat.c @@ -152,3 +152,68 @@ richace_change_mask(struct richacl_alloc *alloc, struct richace **ace, } return 0; } + +/** + * richacl_move_everyone_aces_down - move everyone@ aces to the end of the acl + * @alloc: acl and number of allocated entries + * + * Move all everyone aces to the end of the acl so that only a single everyone@ + * allow ace remains at the end, and update the mask fields of all aces on the + * way. The last ace of the resulting acl will be an everyone@ allow ace only + * if @acl grants any permissions to @everyone. No @everyone deny aces will + * remain. + * + * This transformation does not alter the permissions that the acl grants. + * Having at most one everyone@ allow ace at the end of the acl helps us in the + * following algorithms. + */ +static int +richacl_move_everyone_aces_down(struct richacl_alloc *alloc) +{ + struct richace *ace; + unsigned int allowed = 0, denied = 0; + + richacl_for_each_entry(ace, alloc->acl) { + if (richace_is_inherit_only(ace)) + continue; + if (richace_is_everyone(ace)) { + if (richace_is_allow(ace)) + allowed |= (ace->e_mask & ~denied); + else if (richace_is_deny(ace)) + denied |= (ace->e_mask & ~allowed); + else + continue; + if (richace_change_mask(alloc, &ace, 0)) + return -1; + } else { + if (richace_is_allow(ace)) { + if (richace_change_mask(alloc, &ace, allowed | + (ace->e_mask & ~denied))) + return -1; + } else if (richace_is_deny(ace)) { + if (richace_change_mask(alloc, &ace, denied | + (ace->e_mask & ~allowed))) + return -1; + } + } + } + if (allowed & ~RICHACE_POSIX_ALWAYS_ALLOWED) { + struct richace *last_ace = ace - 1; + + if (alloc->acl->a_entries && + richace_is_everyone(last_ace) && + richace_is_allow(last_ace) && + richace_is_inherit_only(last_ace) && + last_ace->e_mask == allowed) + last_ace->e_flags &= ~RICHACE_INHERIT_ONLY_ACE; + else { + if (richacl_insert_entry(alloc, &ace)) + return -1; + ace->e_type = RICHACE_ACCESS_ALLOWED_ACE_TYPE; + ace->e_flags = RICHACE_SPECIAL_WHO; + ace->e_mask = allowed; + ace->e_id.special = RICHACE_EVERYONE_SPECIAL_ID; + } + } + return 0; +}