Messages in this thread Patch in this message | | | Subject | [PATCH 3/5] Add POSIX Access Control Lists to ext2/3 | From | tytso@mit ... | Date | Tue, 15 Oct 2002 18:21:11 -0400 |
| |
This patch provides converts extended attributes passed in from user space to a generic Posix ACL representation.
- Ted
# This is a BitKeeper generated patch for the following project: # Project Name: Linux kernel tree # # fs/Makefile | 4 - # fs/xattr_acl.c | 99 ++++++++++++++++++++++++++++++++++++++++++++++ # include/linux/xattr_acl.h | 50 +++++++++++++++++++++++ # 3 files changed, 151 insertions(+), 2 deletions(-) # # The following is the BitKeeper ChangeSet Log # -------------------------------------------- # 02/10/15 tytso@snap.thunk.org 1.856 # Port 0.8.50 acl-xattr patch to 2.5 # # This patch provides converts extended attributes passed in from user # space to a generic Posix ACL representation. # -------------------------------------------- # diff -Nru a/fs/Makefile b/fs/Makefile --- a/fs/Makefile Tue Oct 15 16:59:35 2002 +++ b/fs/Makefile Tue Oct 15 16:59:35 2002 @@ -6,7 +6,7 @@ # export-objs := open.o dcache.o buffer.o bio.o inode.o dquot.o mpage.o aio.o \ - fcntl.o read_write.o mbcache.o + fcntl.o read_write.o mbcache.o xattr_acl.o obj-y := open.o read_write.o devices.o file_table.o buffer.o \ bio.o super.o block_dev.o char_dev.o stat.o exec.o pipe.o \ @@ -31,7 +31,7 @@ obj-$(CONFIG_BINFMT_ELF) += binfmt_elf.o obj-$(CONFIG_FS_MBCACHE) += mbcache.o -obj-$(CONFIG_FS_POSIX_ACL) += posix_acl.o +obj-$(CONFIG_FS_POSIX_ACL) += posix_acl.o xattr_acl.o obj-$(CONFIG_QUOTA) += dquot.o obj-$(CONFIG_QFMT_V1) += quota_v1.o diff -Nru a/fs/xattr_acl.c b/fs/xattr_acl.c --- /dev/null Wed Dec 31 16:00:00 1969 +++ b/fs/xattr_acl.c Tue Oct 15 16:59:35 2002 @@ -0,0 +1,99 @@ +/* + * linux/fs/xattr_acl.c + * + * Almost all from linux/fs/ext2/acl.c: + * Copyright (C) 2001 by Andreas Gruenbacher, <a.gruenbacher@computer.org> + */ + +#include <linux/module.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/fs.h> +#include <linux/xattr_acl.h> + + +/* + * Convert from extended attribute to in-memory representation. + */ +struct posix_acl * +posix_acl_from_xattr(const void *value, size_t size) +{ + xattr_acl_header *header = (xattr_acl_header *)value; + xattr_acl_entry *entry = (xattr_acl_entry *)(header+1), *end; + int count; + struct posix_acl *acl; + struct posix_acl_entry *acl_e; + + if (!value) + return NULL; + if (size < sizeof(xattr_acl_header)) + return ERR_PTR(-EINVAL); + if (header->a_version != cpu_to_le32(XATTR_ACL_VERSION)) + return ERR_PTR(-EINVAL); + + count = xattr_acl_count(size); + if (count < 0) + return ERR_PTR(-EINVAL); + if (count == 0) + return NULL; + + acl = posix_acl_alloc(count, GFP_KERNEL); + if (!acl) + return ERR_PTR(-ENOMEM); + acl_e = acl->a_entries; + + for (end = entry + count; entry != end; acl_e++, entry++) { + acl_e->e_tag = le16_to_cpu(entry->e_tag); + acl_e->e_perm = le16_to_cpu(entry->e_perm); + + switch(acl_e->e_tag) { + case ACL_USER_OBJ: + case ACL_GROUP_OBJ: + case ACL_MASK: + case ACL_OTHER: + acl_e->e_id = ACL_UNDEFINED_ID; + break; + + case ACL_USER: + case ACL_GROUP: + acl_e->e_id = le32_to_cpu(entry->e_id); + break; + + default: + goto fail; + } + } + return acl; + +fail: + posix_acl_release(acl); + return ERR_PTR(-EINVAL); +} +EXPORT_SYMBOL (posix_acl_from_xattr); + +/* + * Convert from in-memory to extended attribute representation. + */ +int +posix_acl_to_xattr(const struct posix_acl *acl, void *buffer, size_t size) +{ + xattr_acl_header *ext_acl = (xattr_acl_header *)buffer; + xattr_acl_entry *ext_entry = ext_acl->a_entries; + int real_size, n; + + real_size = xattr_acl_size(acl->a_count); + if (!buffer) + return real_size; + if (real_size > size) + return -ERANGE; + + ext_acl->a_version = cpu_to_le32(XATTR_ACL_VERSION); + + for (n=0; n < acl->a_count; n++, ext_entry++) { + ext_entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag); + ext_entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm); + ext_entry->e_id = cpu_to_le32(acl->a_entries[n].e_id); + } + return real_size; +} +EXPORT_SYMBOL (posix_acl_to_xattr); diff -Nru a/include/linux/xattr_acl.h b/include/linux/xattr_acl.h --- /dev/null Wed Dec 31 16:00:00 1969 +++ b/include/linux/xattr_acl.h Tue Oct 15 16:59:35 2002 @@ -0,0 +1,50 @@ +/* + File: linux/xattr_acl.h + + (extended attribute representation of access control lists) + + (C) 2000 Andreas Gruenbacher, <a.gruenbacher@computer.org> +*/ + +#ifndef _LINUX_XATTR_ACL_H +#define _LINUX_XATTR_ACL_H + +#include <linux/posix_acl.h> + +#define XATTR_NAME_ACL_ACCESS "system.posix_acl_access" +#define XATTR_NAME_ACL_DEFAULT "system.posix_acl_default" + +#define XATTR_ACL_VERSION 0x0002 + +typedef struct { + __u16 e_tag; + __u16 e_perm; + __u32 e_id; +} xattr_acl_entry; + +typedef struct { + __u32 a_version; + xattr_acl_entry a_entries[0]; +} xattr_acl_header; + +static inline size_t xattr_acl_size(int count) +{ + return sizeof(xattr_acl_header) + count * sizeof(xattr_acl_entry); +} + +static inline int xattr_acl_count(size_t size) +{ + if (size < sizeof(xattr_acl_header)) + return -1; + size -= sizeof(xattr_acl_header); + if (size % sizeof(xattr_acl_entry)) + return -1; + return size / sizeof(xattr_acl_entry); +} + +struct posix_acl * posix_acl_from_xattr(const void *value, size_t size); +int posix_acl_to_xattr(const struct posix_acl *acl, void *buffer, size_t size); + + + +#endif /* _LINUX_XATTR_ACL_H */ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |