/*
- * linux/fs/posix_acl.c
+ * Copyright (C) 2002,2003 by Andreas Gruenbacher <a.gruenbacher@computer.org>
*
- * Copyright (C) 2002 by Andreas Gruenbacher <a.gruenbacher@computer.org>
- *
- * Fixes from William Schumacher incorporated on 15 March 2001.
- * (Reported by Charles Bertsch, <CBertsch@microtest.com>).
+ * Fixes from William Schumacher incorporated on 15 March 2001.
+ * (Reported by Charles Bertsch, <CBertsch@microtest.com>).
*/
/*
#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/posix_acl.h>
+#include <linux/posix_acl_xattr.h>
+#include <linux/xattr.h>
#include <linux/export.h>
+#include <linux/user_namespace.h>
-#include <linux/errno.h>
+struct posix_acl **acl_by_type(struct inode *inode, int type)
+{
+ switch (type) {
+ case ACL_TYPE_ACCESS:
+ return &inode->i_acl;
+ case ACL_TYPE_DEFAULT:
+ return &inode->i_default_acl;
+ default:
+ BUG();
+ }
+}
+EXPORT_SYMBOL(acl_by_type);
-EXPORT_SYMBOL(posix_acl_init);
-EXPORT_SYMBOL(posix_acl_alloc);
-EXPORT_SYMBOL(posix_acl_valid);
-EXPORT_SYMBOL(posix_acl_equiv_mode);
-EXPORT_SYMBOL(posix_acl_from_mode);
+struct posix_acl *get_cached_acl(struct inode *inode, int type)
+{
+ struct posix_acl **p = acl_by_type(inode, type);
+ struct posix_acl *acl = ACCESS_ONCE(*p);
+ if (acl) {
+ spin_lock(&inode->i_lock);
+ acl = *p;
+ if (acl != ACL_NOT_CACHED)
+ acl = posix_acl_dup(acl);
+ spin_unlock(&inode->i_lock);
+ }
+ return acl;
+}
+EXPORT_SYMBOL(get_cached_acl);
+
+struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type)
+{
+ return rcu_dereference(*acl_by_type(inode, type));
+}
+EXPORT_SYMBOL(get_cached_acl_rcu);
+
+void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl)
+{
+ struct posix_acl **p = acl_by_type(inode, type);
+ struct posix_acl *old;
+ spin_lock(&inode->i_lock);
+ old = *p;
+ rcu_assign_pointer(*p, posix_acl_dup(acl));
+ spin_unlock(&inode->i_lock);
+ if (old != ACL_NOT_CACHED)
+ posix_acl_release(old);
+}
+EXPORT_SYMBOL(set_cached_acl);
+
+void forget_cached_acl(struct inode *inode, int type)
+{
+ struct posix_acl **p = acl_by_type(inode, type);
+ struct posix_acl *old;
+ spin_lock(&inode->i_lock);
+ old = *p;
+ *p = ACL_NOT_CACHED;
+ spin_unlock(&inode->i_lock);
+ if (old != ACL_NOT_CACHED)
+ posix_acl_release(old);
+}
+EXPORT_SYMBOL(forget_cached_acl);
+
+void forget_all_cached_acls(struct inode *inode)
+{
+ struct posix_acl *old_access, *old_default;
+ spin_lock(&inode->i_lock);
+ old_access = inode->i_acl;
+ old_default = inode->i_default_acl;
+ inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED;
+ spin_unlock(&inode->i_lock);
+ if (old_access != ACL_NOT_CACHED)
+ posix_acl_release(old_access);
+ if (old_default != ACL_NOT_CACHED)
+ posix_acl_release(old_default);
+}
+EXPORT_SYMBOL(forget_all_cached_acls);
+
+struct posix_acl *get_acl(struct inode *inode, int type)
+{
+ struct posix_acl *acl;
+
+ acl = get_cached_acl(inode, type);
+ if (acl != ACL_NOT_CACHED)
+ return acl;
+
+ if (!IS_POSIXACL(inode))
+ return NULL;
+
+ /*
+ * A filesystem can force a ACL callback by just never filling the
+ * ACL cache. But normally you'd fill the cache either at inode
+ * instantiation time, or on the first ->get_acl call.
+ *
+ * If the filesystem doesn't have a get_acl() function at all, we'll
+ * just create the negative cache entry.
+ */
+ if (!inode->i_op->get_acl) {
+ set_cached_acl(inode, type, NULL);
+ return NULL;
+ }
+ return inode->i_op->get_acl(inode, type);
+}
+EXPORT_SYMBOL(get_acl);
/*
* Init a fresh posix_acl
atomic_set(&acl->a_refcount, 1);
acl->a_count = count;
}
+EXPORT_SYMBOL(posix_acl_init);
/*
* Allocate a new ACL with the specified number of entries.
posix_acl_init(acl, count);
return acl;
}
+EXPORT_SYMBOL(posix_acl_alloc);
/*
* Clone an ACL.
{
const struct posix_acl_entry *pa, *pe;
int state = ACL_USER_OBJ;
- kuid_t prev_uid = INVALID_UID;
- kgid_t prev_gid = INVALID_GID;
int needs_mask = 0;
FOREACH_ACL_ENTRY(pa, acl, pe) {
return -EINVAL;
if (!uid_valid(pa->e_uid))
return -EINVAL;
- if (uid_valid(prev_uid) &&
- uid_lte(pa->e_uid, prev_uid))
- return -EINVAL;
- prev_uid = pa->e_uid;
needs_mask = 1;
break;
return -EINVAL;
if (!gid_valid(pa->e_gid))
return -EINVAL;
- if (gid_valid(prev_gid) &&
- gid_lte(pa->e_gid, prev_gid))
- return -EINVAL;
- prev_gid = pa->e_gid;
needs_mask = 1;
break;
return 0;
return -EINVAL;
}
+EXPORT_SYMBOL(posix_acl_valid);
/*
* Returns 0 if the acl can be exactly represented in the traditional
umode_t mode = 0;
int not_equiv = 0;
+ /*
+ * A null ACL can always be presented as mode bits.
+ */
+ if (!acl)
+ return 0;
+
FOREACH_ACL_ENTRY(pa, acl, pe) {
switch (pa->e_tag) {
case ACL_USER_OBJ:
*mode_p = (*mode_p & ~S_IRWXUGO) | mode;
return not_equiv;
}
+EXPORT_SYMBOL(posix_acl_equiv_mode);
/*
* Create an ACL representing the file mode permission bits of an inode.
acl->a_entries[2].e_perm = (mode & S_IRWXO);
return acl;
}
+EXPORT_SYMBOL(posix_acl_from_mode);
/*
* Return 0 if current is granted want access to the inode
/*
* Modify the ACL for the chmod syscall.
*/
-static int posix_acl_chmod_masq(struct posix_acl *acl, umode_t mode)
+static int __posix_acl_chmod_masq(struct posix_acl *acl, umode_t mode)
{
struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL;
struct posix_acl_entry *pa, *pe;
}
int
-posix_acl_create(struct posix_acl **acl, gfp_t gfp, umode_t *mode_p)
+__posix_acl_create(struct posix_acl **acl, gfp_t gfp, umode_t *mode_p)
{
struct posix_acl *clone = posix_acl_clone(*acl, gfp);
int err = -ENOMEM;
*acl = clone;
return err;
}
-EXPORT_SYMBOL(posix_acl_create);
+EXPORT_SYMBOL(__posix_acl_create);
int
-posix_acl_chmod(struct posix_acl **acl, gfp_t gfp, umode_t mode)
+__posix_acl_chmod(struct posix_acl **acl, gfp_t gfp, umode_t mode)
{
struct posix_acl *clone = posix_acl_clone(*acl, gfp);
int err = -ENOMEM;
if (clone) {
- err = posix_acl_chmod_masq(clone, mode);
+ err = __posix_acl_chmod_masq(clone, mode);
if (err) {
posix_acl_release(clone);
clone = NULL;
*acl = clone;
return err;
}
+EXPORT_SYMBOL(__posix_acl_chmod);
+
+int
+posix_acl_chmod(struct inode *inode, umode_t mode)
+{
+ struct posix_acl *acl;
+ int ret = 0;
+
+ if (!IS_POSIXACL(inode))
+ return 0;
+ if (!inode->i_op->set_acl)
+ return -EOPNOTSUPP;
+
+ acl = get_acl(inode, ACL_TYPE_ACCESS);
+ if (IS_ERR_OR_NULL(acl)) {
+ if (acl == ERR_PTR(-EOPNOTSUPP))
+ return 0;
+ return PTR_ERR(acl);
+ }
+
+ ret = __posix_acl_chmod(&acl, GFP_KERNEL, mode);
+ if (ret)
+ return ret;
+ ret = inode->i_op->set_acl(inode, acl, ACL_TYPE_ACCESS);
+ posix_acl_release(acl);
+ return ret;
+}
EXPORT_SYMBOL(posix_acl_chmod);
+
+int
+posix_acl_create(struct inode *dir, umode_t *mode,
+ struct posix_acl **default_acl, struct posix_acl **acl)
+{
+ struct posix_acl *p;
+ struct posix_acl *clone;
+ int ret;
+
+ *acl = NULL;
+ *default_acl = NULL;
+
+ if (S_ISLNK(*mode) || !IS_POSIXACL(dir))
+ return 0;
+
+ p = get_acl(dir, ACL_TYPE_DEFAULT);
+ if (!p || p == ERR_PTR(-EOPNOTSUPP)) {
+ *mode &= ~current_umask();
+ return 0;
+ }
+ if (IS_ERR(p))
+ return PTR_ERR(p);
+
+ clone = posix_acl_clone(p, GFP_NOFS);
+ if (!clone)
+ goto no_mem;
+
+ ret = posix_acl_create_masq(clone, mode);
+ if (ret < 0)
+ goto no_mem_clone;
+
+ if (ret == 0)
+ posix_acl_release(clone);
+ else
+ *acl = clone;
+
+ if (!S_ISDIR(*mode))
+ posix_acl_release(p);
+ else
+ *default_acl = p;
+
+ return 0;
+
+no_mem_clone:
+ posix_acl_release(clone);
+no_mem:
+ posix_acl_release(p);
+ return -ENOMEM;
+}
+EXPORT_SYMBOL_GPL(posix_acl_create);
+
+/**
+ * posix_acl_update_mode - update mode in set_acl
+ *
+ * Update the file mode when setting an ACL: compute the new file permission
+ * bits based on the ACL. In addition, if the ACL is equivalent to the new
+ * file mode, set *acl to NULL to indicate that no ACL should be set.
+ *
+ * As with chmod, clear the setgit bit if the caller is not in the owning group
+ * or capable of CAP_FSETID (see inode_change_ok).
+ *
+ * Called from set_acl inode operations.
+ */
+int posix_acl_update_mode(struct inode *inode, umode_t *mode_p,
+ struct posix_acl **acl)
+{
+ umode_t mode = inode->i_mode;
+ int error;
+
+ error = posix_acl_equiv_mode(*acl, &mode);
+ if (error < 0)
+ return error;
+ if (error == 0)
+ *acl = NULL;
+ if (!in_group_p(inode->i_gid) &&
+ !capable_wrt_inode_uidgid(inode, CAP_FSETID))
+ mode &= ~S_ISGID;
+ *mode_p = mode;
+ return 0;
+}
+EXPORT_SYMBOL(posix_acl_update_mode);
+
+/*
+ * Fix up the uids and gids in posix acl extended attributes in place.
+ */
+static void posix_acl_fix_xattr_userns(
+ struct user_namespace *to, struct user_namespace *from,
+ void *value, size_t size)
+{
+ posix_acl_xattr_header *header = (posix_acl_xattr_header *)value;
+ posix_acl_xattr_entry *entry = (posix_acl_xattr_entry *)(header+1), *end;
+ int count;
+ kuid_t uid;
+ kgid_t gid;
+
+ if (!value)
+ return;
+ if (size < sizeof(posix_acl_xattr_header))
+ return;
+ if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
+ return;
+
+ count = posix_acl_xattr_count(size);
+ if (count < 0)
+ return;
+ if (count == 0)
+ return;
+
+ for (end = entry + count; entry != end; entry++) {
+ switch(le16_to_cpu(entry->e_tag)) {
+ case ACL_USER:
+ uid = make_kuid(from, le32_to_cpu(entry->e_id));
+ entry->e_id = cpu_to_le32(from_kuid(to, uid));
+ break;
+ case ACL_GROUP:
+ gid = make_kgid(from, le32_to_cpu(entry->e_id));
+ entry->e_id = cpu_to_le32(from_kgid(to, gid));
+ break;
+ default:
+ break;
+ }
+ }
+}
+
+void posix_acl_fix_xattr_from_user(void *value, size_t size)
+{
+ struct user_namespace *user_ns = current_user_ns();
+ if (user_ns == &init_user_ns)
+ return;
+ posix_acl_fix_xattr_userns(&init_user_ns, user_ns, value, size);
+}
+
+void posix_acl_fix_xattr_to_user(void *value, size_t size)
+{
+ struct user_namespace *user_ns = current_user_ns();
+ if (user_ns == &init_user_ns)
+ return;
+ posix_acl_fix_xattr_userns(user_ns, &init_user_ns, value, size);
+}
+
+/*
+ * Convert from extended attribute to in-memory representation.
+ */
+struct posix_acl *
+posix_acl_from_xattr(struct user_namespace *user_ns,
+ const void *value, size_t size)
+{
+ posix_acl_xattr_header *header = (posix_acl_xattr_header *)value;
+ posix_acl_xattr_entry *entry = (posix_acl_xattr_entry *)(header+1), *end;
+ int count;
+ struct posix_acl *acl;
+ struct posix_acl_entry *acl_e;
+
+ if (!value)
+ return NULL;
+ if (size < sizeof(posix_acl_xattr_header))
+ return ERR_PTR(-EINVAL);
+ if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION))
+ return ERR_PTR(-EOPNOTSUPP);
+
+ count = posix_acl_xattr_count(size);
+ if (count < 0)
+ return ERR_PTR(-EINVAL);
+ if (count == 0)
+ return NULL;
+
+ acl = posix_acl_alloc(count, GFP_NOFS);
+ 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:
+ break;
+
+ case ACL_USER:
+ acl_e->e_uid =
+ make_kuid(user_ns,
+ le32_to_cpu(entry->e_id));
+ if (!uid_valid(acl_e->e_uid))
+ goto fail;
+ break;
+ case ACL_GROUP:
+ acl_e->e_gid =
+ make_kgid(user_ns,
+ le32_to_cpu(entry->e_id));
+ if (!gid_valid(acl_e->e_gid))
+ goto fail;
+ 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(struct user_namespace *user_ns, const struct posix_acl *acl,
+ void *buffer, size_t size)
+{
+ posix_acl_xattr_header *ext_acl = (posix_acl_xattr_header *)buffer;
+ posix_acl_xattr_entry *ext_entry;
+ int real_size, n;
+
+ real_size = posix_acl_xattr_size(acl->a_count);
+ if (!buffer)
+ return real_size;
+ if (real_size > size)
+ return -ERANGE;
+
+ ext_entry = ext_acl->a_entries;
+ ext_acl->a_version = cpu_to_le32(POSIX_ACL_XATTR_VERSION);
+
+ for (n=0; n < acl->a_count; n++, ext_entry++) {
+ const struct posix_acl_entry *acl_e = &acl->a_entries[n];
+ ext_entry->e_tag = cpu_to_le16(acl_e->e_tag);
+ ext_entry->e_perm = cpu_to_le16(acl_e->e_perm);
+ switch(acl_e->e_tag) {
+ case ACL_USER:
+ ext_entry->e_id =
+ cpu_to_le32(from_kuid(user_ns, acl_e->e_uid));
+ break;
+ case ACL_GROUP:
+ ext_entry->e_id =
+ cpu_to_le32(from_kgid(user_ns, acl_e->e_gid));
+ break;
+ default:
+ ext_entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID);
+ break;
+ }
+ }
+ return real_size;
+}
+EXPORT_SYMBOL (posix_acl_to_xattr);
+
+static int
+posix_acl_xattr_get(const struct xattr_handler *handler,
+ struct dentry *dentry, const char *name,
+ void *value, size_t size)
+{
+ struct posix_acl *acl;
+ int error;
+
+ if (strcmp(name, "") != 0)
+ return -EINVAL;
+ if (!IS_POSIXACL(d_backing_inode(dentry)))
+ return -EOPNOTSUPP;
+ if (d_is_symlink(dentry))
+ return -EOPNOTSUPP;
+
+ acl = get_acl(d_backing_inode(dentry), handler->flags);
+ if (IS_ERR(acl))
+ return PTR_ERR(acl);
+ if (acl == NULL)
+ return -ENODATA;
+
+ error = posix_acl_to_xattr(&init_user_ns, acl, value, size);
+ posix_acl_release(acl);
+
+ return error;
+}
+
+int
+set_posix_acl(struct inode *inode, int type, struct posix_acl *acl)
+{
+ if (!IS_POSIXACL(inode))
+ return -EOPNOTSUPP;
+ if (!inode->i_op->set_acl)
+ return -EOPNOTSUPP;
+
+ if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
+ return acl ? -EACCES : 0;
+ if (!inode_owner_or_capable(inode))
+ return -EPERM;
+
+ if (acl) {
+ int ret = posix_acl_valid(acl);
+ if (ret)
+ return ret;
+ }
+ return inode->i_op->set_acl(inode, acl, type);
+}
+EXPORT_SYMBOL(set_posix_acl);
+
+static int
+posix_acl_xattr_set(const struct xattr_handler *handler,
+ struct dentry *dentry, const char *name,
+ const void *value, size_t size, int flags)
+{
+ struct inode *inode = d_backing_inode(dentry);
+ struct posix_acl *acl = NULL;
+ int ret;
+
+ if (strcmp(name, "") != 0)
+ return -EINVAL;
+
+ if (value) {
+ acl = posix_acl_from_xattr(&init_user_ns, value, size);
+ if (IS_ERR(acl))
+ return PTR_ERR(acl);
+ }
+ ret = set_posix_acl(inode, handler->flags, acl);
+ posix_acl_release(acl);
+ return ret;
+}
+
+static size_t
+posix_acl_xattr_list(const struct xattr_handler *handler,
+ struct dentry *dentry, char *list, size_t list_size,
+ const char *name, size_t name_len)
+{
+ const char *xname = handler->prefix;
+ size_t size;
+
+ if (!IS_POSIXACL(d_backing_inode(dentry)))
+ return 0;
+
+ size = strlen(xname) + 1;
+ if (list && size <= list_size)
+ memcpy(list, xname, size);
+ return size;
+}
+
+const struct xattr_handler posix_acl_access_xattr_handler = {
+ .prefix = POSIX_ACL_XATTR_ACCESS,
+ .flags = ACL_TYPE_ACCESS,
+ .list = posix_acl_xattr_list,
+ .get = posix_acl_xattr_get,
+ .set = posix_acl_xattr_set,
+};
+EXPORT_SYMBOL_GPL(posix_acl_access_xattr_handler);
+
+const struct xattr_handler posix_acl_default_xattr_handler = {
+ .prefix = POSIX_ACL_XATTR_DEFAULT,
+ .flags = ACL_TYPE_DEFAULT,
+ .list = posix_acl_xattr_list,
+ .get = posix_acl_xattr_get,
+ .set = posix_acl_xattr_set,
+};
+EXPORT_SYMBOL_GPL(posix_acl_default_xattr_handler);
+
+int simple_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+{
+ int error;
+
+ if (type == ACL_TYPE_ACCESS) {
+ error = posix_acl_update_mode(inode,
+ &inode->i_mode, &acl);
+ if (error)
+ return error;
+ }
+
+ inode->i_ctime = CURRENT_TIME;
+ set_cached_acl(inode, type, acl);
+ return 0;
+}
+
+int simple_acl_create(struct inode *dir, struct inode *inode)
+{
+ struct posix_acl *default_acl, *acl;
+ int error;
+
+ error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
+ if (error)
+ return error;
+
+ set_cached_acl(inode, ACL_TYPE_DEFAULT, default_acl);
+ set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
+
+ if (default_acl)
+ posix_acl_release(default_acl);
+ if (acl)
+ posix_acl_release(acl);
+ return 0;
+}
projects / firefly-linux-kernel-4.4.55.git / blobdiff