From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932935AbcGLMCy (ORCPT ); Tue, 12 Jul 2016 08:02:54 -0400 Received: from mail-qt0-f173.google.com ([209.85.216.173]:33536 "EHLO mail-qt0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753209AbcGLMCt (ORCPT ); Tue, 12 Jul 2016 08:02:49 -0400 Message-ID: <1468324965.7798.17.camel@redhat.com> Subject: Re: [PATCH v23 18/22] richacl: xattr mapping 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, 12 Jul 2016 08:02:45 -0400 In-Reply-To: <1467294433-3222-19-git-send-email-agruenba@redhat.com> References: <1467294433-3222-1-git-send-email-agruenba@redhat.com> <1467294433-3222-19-git-send-email-agruenba@redhat.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.20.3 (3.20.3-1.fc24) 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 15:47 +0200, Andreas Gruenbacher wrote: > Map between "system.richacl" xattrs and the in-kernel representation. > > Signed-off-by: Andreas Gruenbacher > --- >  fs/Makefile                        |   2 +- >  fs/richacl_xattr.c                 | 161 +++++++++++++++++++++++++++++++++++++ >  include/linux/richacl_xattr.h      |  29 +++++++ >  include/uapi/linux/Kbuild          |   1 + >  include/uapi/linux/richacl_xattr.h |  44 ++++++++++ >  include/uapi/linux/xattr.h         |   2 + >  6 files changed, 238 insertions(+), 1 deletion(-) >  create mode 100644 fs/richacl_xattr.c >  create mode 100644 include/linux/richacl_xattr.h >  create mode 100644 include/uapi/linux/richacl_xattr.h > > diff --git a/fs/Makefile b/fs/Makefile > index 2b3e6f1..262fd67 100644 > --- a/fs/Makefile > +++ b/fs/Makefile > @@ -49,7 +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-$(CONFIG_FS_RICHACL) += richacl.o richacl_xattr.o >   >  obj-y += quota/ >   > diff --git a/fs/richacl_xattr.c b/fs/richacl_xattr.c > new file mode 100644 > index 0000000..dc1ad36 > --- /dev/null > +++ b/fs/richacl_xattr.c > @@ -0,0 +1,161 @@ > +/* > + * 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_from_xattr  -  convert a richacl xattr into the in-memory representation > + */ > +struct richacl * > +richacl_from_xattr(struct user_namespace *user_ns, > +    const void *value, size_t size, int invalid_error) > +{ > + const struct richacl_xattr *xattr_acl = value; > + const struct richace_xattr *xattr_ace = (void *)(xattr_acl + 1); > + struct richacl *acl; > + struct richace *ace; > + int count; > + > + if (size < sizeof(*xattr_acl) || > +     xattr_acl->a_version != RICHACL_XATTR_VERSION || > +     (xattr_acl->a_flags & ~RICHACL_VALID_FLAGS)) > + goto invalid; > + size -= sizeof(*xattr_acl); > + count = le16_to_cpu(xattr_acl->a_count); > + if (count > RICHACL_XATTR_MAX_COUNT) > + goto invalid; > + if (size != count * sizeof(*xattr_ace)) > + goto invalid; > + > + acl = richacl_alloc(count, GFP_NOFS); > + if (!acl) > + return ERR_PTR(-ENOMEM); > + > + acl->a_flags = xattr_acl->a_flags; > + acl->a_owner_mask = le32_to_cpu(xattr_acl->a_owner_mask); > + if (acl->a_owner_mask & ~RICHACE_VALID_MASK) > + goto put_invalid; > + acl->a_group_mask = le32_to_cpu(xattr_acl->a_group_mask); > + if (acl->a_group_mask & ~RICHACE_VALID_MASK) > + goto put_invalid; > + acl->a_other_mask = le32_to_cpu(xattr_acl->a_other_mask); > + if (acl->a_other_mask & ~RICHACE_VALID_MASK) > + goto put_invalid; > + > + richacl_for_each_entry(ace, acl) { > + ace->e_type  = le16_to_cpu(xattr_ace->e_type); > + ace->e_flags = le16_to_cpu(xattr_ace->e_flags); > + ace->e_mask  = le32_to_cpu(xattr_ace->e_mask); > + > + if (ace->e_flags & ~RICHACE_VALID_FLAGS) > + goto put_invalid; > + if (ace->e_flags & RICHACE_SPECIAL_WHO) { > + ace->e_id.special = le32_to_cpu(xattr_ace->e_id); > + if (ace->e_id.special > RICHACE_EVERYONE_SPECIAL_ID) > + goto put_invalid; > + } else if (ace->e_flags & RICHACE_IDENTIFIER_GROUP) { > + u32 id = le32_to_cpu(xattr_ace->e_id); > + > + ace->e_id.gid = make_kgid(user_ns, id); > + if (!gid_valid(ace->e_id.gid)) > + goto put_invalid; > + } else { > + u32 id = le32_to_cpu(xattr_ace->e_id); > + > + ace->e_id.uid = make_kuid(user_ns, id); > + if (!uid_valid(ace->e_id.uid)) > + goto put_invalid; > + } > + if (ace->e_type > RICHACE_ACCESS_DENIED_ACE_TYPE || > +     (ace->e_mask & ~RICHACE_VALID_MASK)) > + goto put_invalid; > + > + xattr_ace++; > + } > + > + return acl; > + > +put_invalid: > + richacl_put(acl); > +invalid: > + return ERR_PTR(invalid_error); > +} > +EXPORT_SYMBOL_GPL(richacl_from_xattr); > + > +/** > + * richacl_xattr_size  -  compute the size of the xattr representation of @acl > + */ > +size_t > +richacl_xattr_size(const struct richacl *acl) > +{ > + size_t size = sizeof(struct richacl_xattr); > + > + size += sizeof(struct richace_xattr) * acl->a_count; > + return size; > +} > +EXPORT_SYMBOL_GPL(richacl_xattr_size); > + > +/** > + * richacl_to_xattr  -  convert @acl into its xattr representation > + * @acl: the richacl to convert > + * @buffer: buffer for the result > + * @size: size of @buffer > + */ > +int > +richacl_to_xattr(struct user_namespace *user_ns, > +  const struct richacl *acl, void *buffer, size_t size) > +{ > + struct richacl_xattr *xattr_acl = buffer; > + struct richace_xattr *xattr_ace; > + const struct richace *ace; > + size_t real_size; > + > + real_size = richacl_xattr_size(acl); > + if (!buffer) > + return real_size; > + if (real_size > size) > + return -ERANGE; > + > + xattr_acl->a_version = RICHACL_XATTR_VERSION; > + xattr_acl->a_flags = acl->a_flags; > + xattr_acl->a_count = cpu_to_le16(acl->a_count); > + > + xattr_acl->a_owner_mask = cpu_to_le32(acl->a_owner_mask); > + xattr_acl->a_group_mask = cpu_to_le32(acl->a_group_mask); > + xattr_acl->a_other_mask = cpu_to_le32(acl->a_other_mask); > + > + xattr_ace = (void *)(xattr_acl + 1); > + richacl_for_each_entry(ace, acl) { > + xattr_ace->e_type = cpu_to_le16(ace->e_type); > + xattr_ace->e_flags = cpu_to_le16(ace->e_flags); > + xattr_ace->e_mask = cpu_to_le32(ace->e_mask); > + if (ace->e_flags & RICHACE_SPECIAL_WHO) > + xattr_ace->e_id = cpu_to_le32(ace->e_id.special); > + else if (ace->e_flags & RICHACE_IDENTIFIER_GROUP) > + xattr_ace->e_id = > + cpu_to_le32(from_kgid(user_ns, ace->e_id.gid)); > + else > + xattr_ace->e_id = > + cpu_to_le32(from_kuid(user_ns, ace->e_id.uid)); > + xattr_ace++; > + } > + return real_size; > +} > +EXPORT_SYMBOL_GPL(richacl_to_xattr); > diff --git a/include/linux/richacl_xattr.h b/include/linux/richacl_xattr.h > new file mode 100644 > index 0000000..0efa14b > --- /dev/null > +++ b/include/linux/richacl_xattr.h > @@ -0,0 +1,29 @@ > +/* > + * 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_XATTR_H > +#define __RICHACL_XATTR_H > + > +#include > +#include > + > +extern struct richacl *richacl_from_xattr(struct user_namespace *, const void *, > +   size_t, int); > +extern size_t richacl_xattr_size(const struct richacl *); > +extern int richacl_to_xattr(struct user_namespace *, const struct richacl *, > +     void *, size_t); > + > +#endif /* __RICHACL_XATTR_H */ > diff --git a/include/uapi/linux/Kbuild b/include/uapi/linux/Kbuild > index abeaa98..c24e106 100644 > --- a/include/uapi/linux/Kbuild > +++ b/include/uapi/linux/Kbuild > @@ -356,6 +356,7 @@ header-y += reiserfs_fs.h >  header-y += reiserfs_xattr.h >  header-y += resource.h >  header-y += richacl.h > +header-y += richacl_xattr.h >  header-y += rfkill.h >  header-y += rio_mport_cdev.h >  header-y += romfs_fs.h > diff --git a/include/uapi/linux/richacl_xattr.h b/include/uapi/linux/richacl_xattr.h > new file mode 100644 > index 0000000..20da204 > --- /dev/null > +++ b/include/uapi/linux/richacl_xattr.h > @@ -0,0 +1,44 @@ > +/* > + * 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_XATTR_H > +#define __UAPI_RICHACL_XATTR_H > + > +#include > +#include > + > +struct richace_xattr { > + __le16 e_type; > + __le16 e_flags; > + __le32 e_mask; > + __le32 e_id; > +}; > + > +struct richacl_xattr { > + __u8 a_version; > + __u8 a_flags; > + __le16 a_count; > + __le32 a_owner_mask; > + __le32 a_group_mask; > + __le32 a_other_mask; > +}; > + > +#define RICHACL_XATTR_VERSION 0 > +#define RICHACL_XATTR_MAX_COUNT \ > + ((XATTR_SIZE_MAX - sizeof(struct richacl_xattr)) / \ > +  sizeof(struct richace_xattr)) > + > +#endif  /* __UAPI_RICHACL_XATTR_H */ > diff --git a/include/uapi/linux/xattr.h b/include/uapi/linux/xattr.h > index 1590c49..1996903 100644 > --- a/include/uapi/linux/xattr.h > +++ b/include/uapi/linux/xattr.h > @@ -73,5 +73,7 @@ >  #define XATTR_POSIX_ACL_DEFAULT  "posix_acl_default" >  #define XATTR_NAME_POSIX_ACL_DEFAULT XATTR_SYSTEM_PREFIX XATTR_POSIX_ACL_DEFAULT >   > +#define XATTR_RICHACL "richacl" > +#define XATTR_NAME_RICHACL XATTR_SYSTEM_PREFIX XATTR_RICHACL >   >  #endif /* _UAPI_LINUX_XATTR_H */ Fair enough. I do wonder a bit whether we might be better served with a new set of syscalls for this instead of using xattrs (as I think Christoph has suggested). What _is_ the rationale for doing this with xattrs, btw? Regardless, this patch looks fine to me, assuming that we really do want to do this xattrs: Reviewed-by: Jeff Layton