2 * Copyright (C) 2012 Red Hat, Inc.
3 * Copyright (C) 2012 Jeremy Kerr <jeremy.kerr@canonical.com>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
10 #include <linux/efi.h>
12 #include <linux/ctype.h>
13 #include <linux/kmemleak.h>
14 #include <linux/slab.h>
15 #include <linux/uuid.h>
19 struct inode *efivarfs_get_inode(struct super_block *sb,
20 const struct inode *dir, int mode,
21 dev_t dev, bool is_removable)
23 struct inode *inode = new_inode(sb);
26 inode->i_ino = get_next_ino();
28 inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
29 inode->i_flags = is_removable ? 0 : S_IMMUTABLE;
30 switch (mode & S_IFMT) {
32 inode->i_fop = &efivarfs_file_operations;
35 inode->i_op = &efivarfs_dir_inode_operations;
36 inode->i_fop = &simple_dir_operations;
45 * Return true if 'str' is a valid efivarfs filename of the form,
47 * VariableName-12345678-1234-1234-1234-1234567891bc
49 bool efivarfs_valid_name(const char *str, int len)
51 const char *s = str + len - EFI_VARIABLE_GUID_LEN;
54 * We need a GUID, plus at least one letter for the variable name,
55 * plus the '-' separator
57 if (len < EFI_VARIABLE_GUID_LEN + 2)
60 /* GUID must be preceded by a '-' */
65 * Validate that 's' is of the correct format, e.g.
67 * 12345678-1234-1234-1234-123456789abc
69 return uuid_is_valid(s);
72 static int efivarfs_create(struct inode *dir, struct dentry *dentry,
73 umode_t mode, bool excl)
75 struct inode *inode = NULL;
76 struct efivar_entry *var;
77 int namelen, i = 0, err = 0;
78 bool is_removable = false;
80 if (!efivarfs_valid_name(dentry->d_name.name, dentry->d_name.len))
83 var = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL);
87 /* length of the variable name itself: remove GUID and separator */
88 namelen = dentry->d_name.len - EFI_VARIABLE_GUID_LEN - 1;
90 uuid_le_to_bin(dentry->d_name.name + namelen + 1, &var->var.VendorGuid);
92 if (efivar_variable_is_removable(var->var.VendorGuid,
93 dentry->d_name.name, namelen))
96 inode = efivarfs_get_inode(dir->i_sb, dir, mode, 0, is_removable);
102 for (i = 0; i < namelen; i++)
103 var->var.VariableName[i] = dentry->d_name.name[i];
105 var->var.VariableName[i] = '\0';
107 inode->i_private = var;
108 kmemleak_ignore(var);
110 err = efivar_entry_add(var, &efivarfs_list);
114 d_instantiate(dentry, inode);
125 static int efivarfs_unlink(struct inode *dir, struct dentry *dentry)
127 struct efivar_entry *var = d_inode(dentry)->i_private;
129 if (efivar_entry_delete(var))
132 drop_nlink(d_inode(dentry));
137 const struct inode_operations efivarfs_dir_inode_operations = {
138 .lookup = simple_lookup,
139 .unlink = efivarfs_unlink,
140 .create = efivarfs_create,