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6d848a488a
shmfs wants purely standard POSIX ACL semantics, so we can use the new generic VFS layer POSIX ACL checking rather than cooking our own 'permission()' function. Reviewed-by: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
172 lines
4.0 KiB
C
172 lines
4.0 KiB
C
/*
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* mm/shmem_acl.c
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*
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* (C) 2005 Andreas Gruenbacher <agruen@suse.de>
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*
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* This file is released under the GPL.
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*/
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#include <linux/fs.h>
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#include <linux/shmem_fs.h>
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#include <linux/xattr.h>
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#include <linux/generic_acl.h>
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/**
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* shmem_get_acl - generic_acl_operations->getacl() operation
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*/
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static struct posix_acl *
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shmem_get_acl(struct inode *inode, int type)
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{
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struct posix_acl *acl = NULL;
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spin_lock(&inode->i_lock);
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switch(type) {
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case ACL_TYPE_ACCESS:
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acl = posix_acl_dup(inode->i_acl);
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break;
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case ACL_TYPE_DEFAULT:
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acl = posix_acl_dup(inode->i_default_acl);
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break;
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}
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spin_unlock(&inode->i_lock);
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return acl;
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}
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/**
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* shmem_set_acl - generic_acl_operations->setacl() operation
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*/
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static void
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shmem_set_acl(struct inode *inode, int type, struct posix_acl *acl)
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{
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struct posix_acl *free = NULL;
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spin_lock(&inode->i_lock);
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switch(type) {
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case ACL_TYPE_ACCESS:
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free = inode->i_acl;
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inode->i_acl = posix_acl_dup(acl);
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break;
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case ACL_TYPE_DEFAULT:
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free = inode->i_default_acl;
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inode->i_default_acl = posix_acl_dup(acl);
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break;
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}
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spin_unlock(&inode->i_lock);
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posix_acl_release(free);
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}
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struct generic_acl_operations shmem_acl_ops = {
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.getacl = shmem_get_acl,
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.setacl = shmem_set_acl,
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};
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/**
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* shmem_list_acl_access, shmem_get_acl_access, shmem_set_acl_access,
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* shmem_xattr_acl_access_handler - plumbing code to implement the
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* system.posix_acl_access xattr using the generic acl functions.
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*/
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static size_t
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shmem_list_acl_access(struct inode *inode, char *list, size_t list_size,
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const char *name, size_t name_len)
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{
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return generic_acl_list(inode, &shmem_acl_ops, ACL_TYPE_ACCESS,
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list, list_size);
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}
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static int
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shmem_get_acl_access(struct inode *inode, const char *name, void *buffer,
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size_t size)
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{
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if (strcmp(name, "") != 0)
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return -EINVAL;
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return generic_acl_get(inode, &shmem_acl_ops, ACL_TYPE_ACCESS, buffer,
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size);
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}
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static int
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shmem_set_acl_access(struct inode *inode, const char *name, const void *value,
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size_t size, int flags)
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{
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if (strcmp(name, "") != 0)
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return -EINVAL;
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return generic_acl_set(inode, &shmem_acl_ops, ACL_TYPE_ACCESS, value,
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size);
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}
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struct xattr_handler shmem_xattr_acl_access_handler = {
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.prefix = POSIX_ACL_XATTR_ACCESS,
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.list = shmem_list_acl_access,
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.get = shmem_get_acl_access,
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.set = shmem_set_acl_access,
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};
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/**
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* shmem_list_acl_default, shmem_get_acl_default, shmem_set_acl_default,
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* shmem_xattr_acl_default_handler - plumbing code to implement the
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* system.posix_acl_default xattr using the generic acl functions.
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*/
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static size_t
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shmem_list_acl_default(struct inode *inode, char *list, size_t list_size,
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const char *name, size_t name_len)
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{
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return generic_acl_list(inode, &shmem_acl_ops, ACL_TYPE_DEFAULT,
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list, list_size);
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}
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static int
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shmem_get_acl_default(struct inode *inode, const char *name, void *buffer,
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size_t size)
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{
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if (strcmp(name, "") != 0)
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return -EINVAL;
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return generic_acl_get(inode, &shmem_acl_ops, ACL_TYPE_DEFAULT, buffer,
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size);
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}
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static int
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shmem_set_acl_default(struct inode *inode, const char *name, const void *value,
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size_t size, int flags)
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{
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if (strcmp(name, "") != 0)
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return -EINVAL;
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return generic_acl_set(inode, &shmem_acl_ops, ACL_TYPE_DEFAULT, value,
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size);
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}
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struct xattr_handler shmem_xattr_acl_default_handler = {
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.prefix = POSIX_ACL_XATTR_DEFAULT,
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.list = shmem_list_acl_default,
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.get = shmem_get_acl_default,
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.set = shmem_set_acl_default,
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};
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/**
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* shmem_acl_init - Inizialize the acl(s) of a new inode
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*/
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int
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shmem_acl_init(struct inode *inode, struct inode *dir)
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{
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return generic_acl_init(inode, dir, &shmem_acl_ops);
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}
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/**
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* shmem_check_acl - check_acl() callback for generic_permission()
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*/
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int
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shmem_check_acl(struct inode *inode, int mask)
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{
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struct posix_acl *acl = shmem_get_acl(inode, ACL_TYPE_ACCESS);
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if (acl) {
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int error = posix_acl_permission(inode, acl, mask);
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posix_acl_release(acl);
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return error;
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}
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return -EAGAIN;
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}
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