From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932949AbcGELeR (ORCPT ); Tue, 5 Jul 2016 07:34:17 -0400 Received: from mail-qt0-f176.google.com ([209.85.216.176]:34898 "EHLO mail-qt0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932826AbcGELeM (ORCPT ); Tue, 5 Jul 2016 07:34:12 -0400 Message-ID: <1467718448.3800.16.camel@redhat.com> Subject: Re: [PATCH v23 06/22] richacl: In-memory representation and helper functions From: Jeff Layton To: Andreas Gruenbacher , Alexander Viro Cc: Christoph Hellwig , "Theodore Ts'o" , Andreas Dilger , "J. Bruce Fields" , Trond Myklebust , Anna Schumaker , Dave Chinner , linux-ext4@vger.kernel.org, xfs@oss.sgi.com, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org, linux-api@vger.kernel.org Date: Tue, 05 Jul 2016 07:34:08 -0400 In-Reply-To: <1467294433-3222-7-git-send-email-agruenba@redhat.com> References: <1467294433-3222-1-git-send-email-agruenba@redhat.com> <1467294433-3222-7-git-send-email-agruenba@redhat.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.18.5.2 (3.18.5.2-1.fc23) Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2016-06-30 at 15:46 +0200, Andreas Gruenbacher wrote: > A richacl consists of an NFSv4 acl and an owner, group, and other mask. > These three masks correspond to the owner, group, and other file > permission bits, but they contain NFSv4 permissions instead of POSIX > permissions. > > Each entry in the NFSv4 acl applies to the file owner (OWNER@), the > owning group (GROUP@), everyone (EVERYONE@), or to a specific uid or > gid. > > As in the standard POSIX file permission model, each process is the > owner, group, or other file class.  A richacl grants a requested access > only if the NFSv4 acl in the richacl grants the access (according to the > NFSv4 permission check algorithm), and the file mask that applies to the > process includes the requested permissions. > > Signed-off-by: Andreas Gruenbacher > Reviewed-by: J. Bruce Fields > --- >  fs/Makefile                  |   1 + >  fs/richacl.c                 |  65 ++++++++++++++++ >  include/linux/richacl.h      | 179 +++++++++++++++++++++++++++++++++++++++++++ >  include/uapi/linux/Kbuild    |   1 + >  include/uapi/linux/richacl.h |  99 ++++++++++++++++++++++++ >  5 files changed, 345 insertions(+) >  create mode 100644 fs/richacl.c >  create mode 100644 include/linux/richacl.h >  create mode 100644 include/uapi/linux/richacl.h > > diff --git a/fs/Makefile b/fs/Makefile > index 85b6e13..2b3e6f1 100644 > --- a/fs/Makefile > +++ b/fs/Makefile > @@ -49,6 +49,7 @@ obj-$(CONFIG_COREDUMP) += coredump.o >  obj-$(CONFIG_SYSCTL) += drop_caches.o >   >  obj-$(CONFIG_FHANDLE) += fhandle.o > +obj-$(CONFIG_FS_RICHACL) += richacl.o >   >  obj-y += quota/ >   > diff --git a/fs/richacl.c b/fs/richacl.c > new file mode 100644 > index 0000000..bcc6591 > --- /dev/null > +++ b/fs/richacl.c > @@ -0,0 +1,65 @@ > +/* > + * Copyright (C) 2006, 2010  Novell, Inc. > + * Copyright (C) 2015  Red Hat, Inc. > + * Written by Andreas Gruenbacher > + * > + * This program is free software; you can redistribute it and/or modify it > + * under the terms of the GNU General Public License as published by the > + * Free Software Foundation; either version 2, or (at your option) any > + * later version. > + * > + * This program is distributed in the hope that it will be useful, but > + * WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU > + * General Public License for more details. > + */ > + > +#include > +#include > +#include > +#include > +#include > + > +/** > + * richacl_alloc  -  allocate a richacl > + * @count: number of entries > + */ > +struct richacl * > +richacl_alloc(int count, gfp_t gfp) > +{ > + size_t size = sizeof(struct richacl) + count * sizeof(struct richace); > + struct richacl *acl = kzalloc(size, gfp); > + > + if (acl) { > + atomic_set(&acl->a_refcount, 1); > + acl->a_count = count; > + } > + return acl; > +} > +EXPORT_SYMBOL_GPL(richacl_alloc); > + I imagine we could have a lot of these at any given time. It might be nice to consider how to do this with dedicated slabcaches for better packing, but I think that would add to the complexity, unfortunately. > +/** > + * richacl_clone  -  create a copy of a richacl > + */ > +struct richacl * > +richacl_clone(const struct richacl *acl, gfp_t gfp) > +{ > + int count = acl->a_count; > + size_t size = sizeof(struct richacl) + count * sizeof(struct richace); > + struct richacl *dup = kmalloc(size, gfp); > + > + if (dup) { > + memcpy(dup, acl, size); > + atomic_set(&dup->a_refcount, 1); > + } > + return dup; > +} > + > +/** > + * richace_copy  -  copy an acl entry > + */ > +void > +richace_copy(struct richace *to, const struct richace *from) > +{ > + memcpy(to, from, sizeof(struct richace)); > +} > diff --git a/include/linux/richacl.h b/include/linux/richacl.h > new file mode 100644 > index 0000000..edb8480 > --- /dev/null > +++ b/include/linux/richacl.h > @@ -0,0 +1,179 @@ > +/* > + * Copyright (C) 2006, 2010  Novell, Inc. > + * Copyright (C) 2015  Red Hat, Inc. > + * Written by Andreas Gruenbacher > + * > + * This program is free software; you can redistribute it and/or modify it > + * under the terms of the GNU General Public License as published by the > + * Free Software Foundation; either version 2, or (at your option) any > + * later version. > + * > + * This program is distributed in the hope that it will be useful, but > + * WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU > + * General Public License for more details. > + */ > + > +#ifndef __RICHACL_H > +#define __RICHACL_H > + > +#include > + > +struct richace { > + unsigned short e_type; > + unsigned short e_flags; > + unsigned int e_mask; > + union { > + kuid_t uid; > + kgid_t gid; > + unsigned int special; > + } e_id; > +}; > + > +struct richacl { > + atomic_t a_refcount; > + unsigned int a_owner_mask; > + unsigned int a_group_mask; > + unsigned int a_other_mask; > + unsigned short a_count; > + unsigned short a_flags; > + struct richace a_entries[0]; > +}; > + > +#define richacl_for_each_entry(_ace, _acl) \ > + for (_ace = (_acl)->a_entries; \ > +      _ace != (_acl)->a_entries + (_acl)->a_count; \ > +      _ace++) > + > +#define richacl_for_each_entry_reverse(_ace, _acl) \ > + for (_ace = (_acl)->a_entries + (_acl)->a_count - 1; \ > +      _ace != (_acl)->a_entries - 1; \ > +      _ace--) > + > +/** > + * richacl_get  -  grab another reference to a richacl handle > + */ > +static inline struct richacl * > +richacl_get(struct richacl *acl) > +{ > + if (acl) > + atomic_inc(&acl->a_refcount); > + return acl; > +} > + > +/** > + * richacl_put  -  free a richacl handle > + */ > +static inline void > +richacl_put(struct richacl *acl) > +{ > + if (acl && atomic_dec_and_test(&acl->a_refcount)) > + kfree(acl); > +} > + > +/** > + * richace_is_owner  -  check if @ace is an OWNER@ entry > + */ > +static inline bool > +richace_is_owner(const struct richace *ace) > +{ > + return (ace->e_flags & RICHACE_SPECIAL_WHO) && > +        ace->e_id.special == RICHACE_OWNER_SPECIAL_ID; > +} > + > +/** > + * richace_is_group  -  check if @ace is a GROUP@ entry > + */ > +static inline bool > +richace_is_group(const struct richace *ace) > +{ > + return (ace->e_flags & RICHACE_SPECIAL_WHO) && > +        ace->e_id.special == RICHACE_GROUP_SPECIAL_ID; > +} > + > +/** > + * richace_is_everyone  -  check if @ace is an EVERYONE@ entry > + */ > +static inline bool > +richace_is_everyone(const struct richace *ace) > +{ > + return (ace->e_flags & RICHACE_SPECIAL_WHO) && > +        ace->e_id.special == RICHACE_EVERYONE_SPECIAL_ID; > +} > + > +/** > + * richace_is_unix_user  -  check if @ace applies to a specific user > + */ > +static inline bool > +richace_is_unix_user(const struct richace *ace) > +{ > + return !(ace->e_flags & RICHACE_SPECIAL_WHO) && > +        !(ace->e_flags & RICHACE_IDENTIFIER_GROUP); > +} > + > +/** > + * richace_is_unix_group  -  check if @ace applies to a specific group > + */ > +static inline bool > +richace_is_unix_group(const struct richace *ace) > +{ > + return !(ace->e_flags & RICHACE_SPECIAL_WHO) && > +        (ace->e_flags & RICHACE_IDENTIFIER_GROUP); > +} > + > +/** > + * richace_is_inherit_only  -  check if @ace is for inheritance only > + * > + * ACEs with the %RICHACE_INHERIT_ONLY_ACE flag set have no effect during > + * permission checking. > + */ > +static inline bool > +richace_is_inherit_only(const struct richace *ace) > +{ > + return ace->e_flags & RICHACE_INHERIT_ONLY_ACE; > +} > + > +/** > + * richace_is_inheritable  -  check if @ace is inheritable > + */ > +static inline bool > +richace_is_inheritable(const struct richace *ace) > +{ > + return ace->e_flags & (RICHACE_FILE_INHERIT_ACE | > +        RICHACE_DIRECTORY_INHERIT_ACE); > +} > + > +/** > + * richace_is_allow  -  check if @ace is an %ALLOW type entry > + */ > +static inline bool > +richace_is_allow(const struct richace *ace) > +{ > + return ace->e_type == RICHACE_ACCESS_ALLOWED_ACE_TYPE; > +} > + > +/** > + * richace_is_deny  -  check if @ace is a %DENY type entry > + */ > +static inline bool > +richace_is_deny(const struct richace *ace) > +{ > + return ace->e_type == RICHACE_ACCESS_DENIED_ACE_TYPE; > +} > + > +/** > + * richace_is_same_identifier  -  are both identifiers the same? > + */ > +static inline bool > +richace_is_same_identifier(const struct richace *a, const struct richace *b) > +{ > + return !((a->e_flags ^ b->e_flags) & > +  (RICHACE_SPECIAL_WHO | RICHACE_IDENTIFIER_GROUP)) && > +        !memcmp(&a->e_id, &b->e_id, sizeof(a->e_id)); > +} > + > +extern struct richacl *richacl_alloc(int, gfp_t); > +extern struct richacl *richacl_clone(const struct richacl *, gfp_t); > +extern void richace_copy(struct richace *, const struct richace *); > + > +#endif /* __RICHACL_H */ > diff --git a/include/uapi/linux/Kbuild b/include/uapi/linux/Kbuild > index 8bdae34..abeaa98 100644 > --- a/include/uapi/linux/Kbuild > +++ b/include/uapi/linux/Kbuild > @@ -355,6 +355,7 @@ header-y += reboot.h >  header-y += reiserfs_fs.h >  header-y += reiserfs_xattr.h >  header-y += resource.h > +header-y += richacl.h >  header-y += rfkill.h >  header-y += rio_mport_cdev.h >  header-y += romfs_fs.h > diff --git a/include/uapi/linux/richacl.h b/include/uapi/linux/richacl.h > new file mode 100644 > index 0000000..08856f8 > --- /dev/null > +++ b/include/uapi/linux/richacl.h > @@ -0,0 +1,99 @@ > +/* > + * Copyright (C) 2006, 2010  Novell, Inc. > + * Copyright (C) 2015  Red Hat, Inc. > + * Written by Andreas Gruenbacher > + * > + * This file is free software; you can redistribute it and/or > + * modify it under the terms of the GNU Lesser General Public > + * License as published by the Free Software Foundation; either > + * version 2.1 of the License, or (at your option) any later version. > + * > + * This file is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU > + * Lesser General Public License for more details. > + */ > + > +#ifndef __UAPI_RICHACL_H > +#define __UAPI_RICHACL_H > + > +/* a_flags values */ > +#define RICHACL_WRITE_THROUGH 0x40 > +#define RICHACL_MASKED 0x80 > + > +/* e_type values */ > +#define RICHACE_ACCESS_ALLOWED_ACE_TYPE 0x0000 > +#define RICHACE_ACCESS_DENIED_ACE_TYPE 0x0001 > + > +/* e_flags bitflags */ > +#define RICHACE_FILE_INHERIT_ACE 0x0001 > +#define RICHACE_DIRECTORY_INHERIT_ACE 0x0002 > +#define RICHACE_NO_PROPAGATE_INHERIT_ACE 0x0004 > +#define RICHACE_INHERIT_ONLY_ACE 0x0008 > +#define RICHACE_IDENTIFIER_GROUP 0x0040 > +#define RICHACE_SPECIAL_WHO 0x4000 > + > +/* e_mask bitflags */ > +#define RICHACE_READ_DATA 0x00000001 > +#define RICHACE_LIST_DIRECTORY 0x00000001 > +#define RICHACE_WRITE_DATA 0x00000002 > +#define RICHACE_ADD_FILE 0x00000002 > +#define RICHACE_APPEND_DATA 0x00000004 > +#define RICHACE_ADD_SUBDIRECTORY 0x00000004 > +#define RICHACE_READ_NAMED_ATTRS 0x00000008 > +#define RICHACE_WRITE_NAMED_ATTRS 0x00000010 > +#define RICHACE_EXECUTE 0x00000020 > +#define RICHACE_DELETE_CHILD 0x00000040 > +#define RICHACE_READ_ATTRIBUTES 0x00000080 > +#define RICHACE_WRITE_ATTRIBUTES 0x00000100 > +#define RICHACE_WRITE_RETENTION 0x00000200 > +#define RICHACE_WRITE_RETENTION_HOLD 0x00000400 > +#define RICHACE_DELETE 0x00010000 > +#define RICHACE_READ_ACL 0x00020000 > +#define RICHACE_WRITE_ACL 0x00040000 > +#define RICHACE_WRITE_OWNER 0x00080000 > +#define RICHACE_SYNCHRONIZE 0x00100000 > + > +/* e_id values */ > +#define RICHACE_OWNER_SPECIAL_ID 0 > +#define RICHACE_GROUP_SPECIAL_ID 1 > +#define RICHACE_EVERYONE_SPECIAL_ID 2 > + > +#define RICHACL_VALID_FLAGS ( \ > + RICHACL_WRITE_THROUGH | \ > + RICHACL_MASKED ) > + > +#define RICHACE_VALID_FLAGS ( \ > + RICHACE_FILE_INHERIT_ACE | \ > + RICHACE_DIRECTORY_INHERIT_ACE | \ > + RICHACE_NO_PROPAGATE_INHERIT_ACE | \ > + RICHACE_INHERIT_ONLY_ACE | \ > + RICHACE_IDENTIFIER_GROUP | \ > + RICHACE_SPECIAL_WHO ) > + > +#define RICHACE_INHERITANCE_FLAGS ( \ > + RICHACE_FILE_INHERIT_ACE | \ > + RICHACE_DIRECTORY_INHERIT_ACE | \ > + RICHACE_NO_PROPAGATE_INHERIT_ACE | \ > + RICHACE_INHERIT_ONLY_ACE ) > + > +/* Valid RICHACE_* flags for directories and non-directories */ > +#define RICHACE_VALID_MASK ( \ > + RICHACE_READ_DATA | RICHACE_LIST_DIRECTORY | \ > + RICHACE_WRITE_DATA | RICHACE_ADD_FILE | \ > + RICHACE_APPEND_DATA | RICHACE_ADD_SUBDIRECTORY | \ > + RICHACE_READ_NAMED_ATTRS | \ > + RICHACE_WRITE_NAMED_ATTRS | \ > + RICHACE_EXECUTE | \ > + RICHACE_DELETE_CHILD | \ > + RICHACE_READ_ATTRIBUTES | \ > + RICHACE_WRITE_ATTRIBUTES | \ > + RICHACE_WRITE_RETENTION | \ > + RICHACE_WRITE_RETENTION_HOLD | \ > + RICHACE_DELETE | \ > + RICHACE_READ_ACL | \ > + RICHACE_WRITE_ACL | \ > + RICHACE_WRITE_OWNER | \ > + RICHACE_SYNCHRONIZE ) > + > +#endif /* __UAPI_RICHACL_H */ Reviewed-by: Jeff Layton