From: Andreas Gruenbacher Subject: Re: [PATCH v23 06/22] richacl: In-memory representation and helper functions Date: Mon, 11 Jul 2016 12:11:56 +0200 Message-ID: References: <1467294433-3222-1-git-send-email-agruenba@redhat.com> <1467294433-3222-7-git-send-email-agruenba@redhat.com> <1467718448.3800.16.camel@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: Alexander Viro , Christoph Hellwig , "Theodore Ts'o" , Andreas Dilger , "J. Bruce Fields" , Trond Myklebust , Anna Schumaker , Dave Chinner , linux-ext4 , XFS Developers , LKML , linux-fsdevel , Linux NFS Mailing List , linux-cifs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Linux API To: Jeff Layton Return-path: In-Reply-To: <1467718448.3800.16.camel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> Sender: linux-cifs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-ext4.vger.kernel.org On Tue, Jul 5, 2016 at 1:34 PM, Jeff Layton wrote: > 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. The objects are variable in size, so that wouldn't work. >> +/** >> + * 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 Thanks, Andreas