| Message ID | 1467294433-3222-19-git-send-email-agruenba@redhat.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
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 <agruenba@redhat.com> > --- > 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 <agruenba@redhat.com> > + * > + * 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 <agruenba@redhat.com> > + * > + * 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 <agruenba@redhat.com> > + * > + * 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 <jlayton@redhat.com>
On Tue, Jul 12, 2016 at 2:02 PM, Jeff Layton <jlayton@redhat.com> wrote: > 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 <agruenba@redhat.com> >> --- >> 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 <agruenba@redhat.com> >> + * >> + * 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 <agruenba@redhat.com> >> + * >> + * 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 <agruenba@redhat.com> >> + * >> + * 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? Xattrs are intended for exactly this kind of auxiliary file information. They are used for POSIX ACLs as well, and they are not going to go away. A number of utilities now include support for xattrs. By using xattrs for Richacls, those tools will automatically have at least basic Richacl support (for backup/restore and similar purposes, for example). In the kernel, supporting a new set of xattrs is pretty cheap and easy. So I really don't see the point of inventing yet another interface for basically the same type of information. > Regardless, this patch looks fine to me, assuming that we really do > want to do this xattrs: > > Reviewed-by: Jeff Layton <jlayton@redhat.com> Thanks, Andreas
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 <agruenba@redhat.com> + * + * 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 <linux/sched.h> +#include <linux/fs.h> +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/richacl_xattr.h> + +/** + * 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 <agruenba@redhat.com> + * + * 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 <uapi/linux/richacl_xattr.h> +#include <linux/richacl.h> + +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 <agruenba@redhat.com> + * + * 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 <linux/types.h> +#include <linux/limits.h> + +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 */
Map between "system.richacl" xattrs and the in-kernel representation. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> --- 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