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10#include <linux/efi.h>
11#include <linux/fs.h>
12#include <linux/ctype.h>
13#include <linux/slab.h>
14#include <linux/uuid.h>
15
16#include "internal.h"
17
18struct inode *efivarfs_get_inode(struct super_block *sb,
19 const struct inode *dir, int mode,
20 dev_t dev, bool is_removable)
21{
22 struct inode *inode = new_inode(sb);
23
24 if (inode) {
25 inode->i_ino = get_next_ino();
26 inode->i_mode = mode;
27 inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
28 inode->i_flags = is_removable ? 0 : S_IMMUTABLE;
29 switch (mode & S_IFMT) {
30 case S_IFREG:
31 inode->i_fop = &efivarfs_file_operations;
32 break;
33 case S_IFDIR:
34 inode->i_op = &efivarfs_dir_inode_operations;
35 inode->i_fop = &simple_dir_operations;
36 inc_nlink(inode);
37 break;
38 }
39 }
40 return inode;
41}
42
43
44
45
46
47
48bool efivarfs_valid_name(const char *str, int len)
49{
50 const char *s = str + len - EFI_VARIABLE_GUID_LEN;
51
52
53
54
55
56 if (len < EFI_VARIABLE_GUID_LEN + 2)
57 return false;
58
59
60 if (*(s - 1) != '-')
61 return false;
62
63
64
65
66
67
68 return uuid_is_valid(s);
69}
70
71static int efivarfs_create(struct inode *dir, struct dentry *dentry,
72 umode_t mode, bool excl)
73{
74 struct inode *inode = NULL;
75 struct efivar_entry *var;
76 int namelen, i = 0, err = 0;
77 bool is_removable = false;
78
79 if (!efivarfs_valid_name(dentry->d_name.name, dentry->d_name.len))
80 return -EINVAL;
81
82 var = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL);
83 if (!var)
84 return -ENOMEM;
85
86
87 namelen = dentry->d_name.len - EFI_VARIABLE_GUID_LEN - 1;
88
89 err = guid_parse(dentry->d_name.name + namelen + 1, &var->var.VendorGuid);
90 if (err)
91 goto out;
92
93 if (efivar_variable_is_removable(var->var.VendorGuid,
94 dentry->d_name.name, namelen))
95 is_removable = true;
96
97 inode = efivarfs_get_inode(dir->i_sb, dir, mode, 0, is_removable);
98 if (!inode) {
99 err = -ENOMEM;
100 goto out;
101 }
102
103 for (i = 0; i < namelen; i++)
104 var->var.VariableName[i] = dentry->d_name.name[i];
105
106 var->var.VariableName[i] = '\0';
107
108 inode->i_private = var;
109
110 err = efivar_entry_add(var, &efivarfs_list);
111 if (err)
112 goto out;
113
114 d_instantiate(dentry, inode);
115 dget(dentry);
116out:
117 if (err) {
118 kfree(var);
119 if (inode)
120 iput(inode);
121 }
122 return err;
123}
124
125static int efivarfs_unlink(struct inode *dir, struct dentry *dentry)
126{
127 struct efivar_entry *var = d_inode(dentry)->i_private;
128
129 if (efivar_entry_delete(var))
130 return -EINVAL;
131
132 drop_nlink(d_inode(dentry));
133 dput(dentry);
134 return 0;
135};
136
137const struct inode_operations efivarfs_dir_inode_operations = {
138 .lookup = simple_lookup,
139 .unlink = efivarfs_unlink,
140 .create = efivarfs_create,
141};
142