Merge remote-tracking branch 'docs/docs-move'
[linux-2.6/next.git] / security / apparmor / apparmorfs.c
blob0848292982a2315f9e491728afe2714ad767bca0
1 /*
2 * AppArmor security module
4 * This file contains AppArmor /sys/kernel/security/apparmor interface functions
6 * Copyright (C) 1998-2008 Novell/SUSE
7 * Copyright 2009-2010 Canonical Ltd.
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation, version 2 of the
12 * License.
15 #include <linux/security.h>
16 #include <linux/vmalloc.h>
17 #include <linux/module.h>
18 #include <linux/seq_file.h>
19 #include <linux/uaccess.h>
20 #include <linux/namei.h>
22 #include "include/apparmor.h"
23 #include "include/apparmorfs.h"
24 #include "include/audit.h"
25 #include "include/context.h"
26 #include "include/policy.h"
28 /**
29 * aa_simple_write_to_buffer - common routine for getting policy from user
30 * @op: operation doing the user buffer copy
31 * @userbuf: user buffer to copy data from (NOT NULL)
32 * @alloc_size: size of user buffer (REQUIRES: @alloc_size >= @copy_size)
33 * @copy_size: size of data to copy from user buffer
34 * @pos: position write is at in the file (NOT NULL)
36 * Returns: kernel buffer containing copy of user buffer data or an
37 * ERR_PTR on failure.
39 static char *aa_simple_write_to_buffer(int op, const char __user *userbuf,
40 size_t alloc_size, size_t copy_size,
41 loff_t *pos)
43 char *data;
45 BUG_ON(copy_size > alloc_size);
47 if (*pos != 0)
48 /* only writes from pos 0, that is complete writes */
49 return ERR_PTR(-ESPIPE);
52 * Don't allow profile load/replace/remove from profiles that don't
53 * have CAP_MAC_ADMIN
55 if (!aa_may_manage_policy(op))
56 return ERR_PTR(-EACCES);
58 /* freed by caller to simple_write_to_buffer */
59 data = kvmalloc(alloc_size);
60 if (data == NULL)
61 return ERR_PTR(-ENOMEM);
63 if (copy_from_user(data, userbuf, copy_size)) {
64 kvfree(data);
65 return ERR_PTR(-EFAULT);
68 return data;
72 /* .load file hook fn to load policy */
73 static ssize_t profile_load(struct file *f, const char __user *buf, size_t size,
74 loff_t *pos)
76 char *data;
77 ssize_t error;
79 data = aa_simple_write_to_buffer(OP_PROF_LOAD, buf, size, size, pos);
81 error = PTR_ERR(data);
82 if (!IS_ERR(data)) {
83 error = aa_replace_profiles(data, size, PROF_ADD);
84 kvfree(data);
87 return error;
90 static const struct file_operations aa_fs_profile_load = {
91 .write = profile_load,
92 .llseek = default_llseek,
95 /* .replace file hook fn to load and/or replace policy */
96 static ssize_t profile_replace(struct file *f, const char __user *buf,
97 size_t size, loff_t *pos)
99 char *data;
100 ssize_t error;
102 data = aa_simple_write_to_buffer(OP_PROF_REPL, buf, size, size, pos);
103 error = PTR_ERR(data);
104 if (!IS_ERR(data)) {
105 error = aa_replace_profiles(data, size, PROF_REPLACE);
106 kvfree(data);
109 return error;
112 static const struct file_operations aa_fs_profile_replace = {
113 .write = profile_replace,
114 .llseek = default_llseek,
117 /* .remove file hook fn to remove loaded policy */
118 static ssize_t profile_remove(struct file *f, const char __user *buf,
119 size_t size, loff_t *pos)
121 char *data;
122 ssize_t error;
125 * aa_remove_profile needs a null terminated string so 1 extra
126 * byte is allocated and the copied data is null terminated.
128 data = aa_simple_write_to_buffer(OP_PROF_RM, buf, size + 1, size, pos);
130 error = PTR_ERR(data);
131 if (!IS_ERR(data)) {
132 data[size] = 0;
133 error = aa_remove_profiles(data, size);
134 kvfree(data);
137 return error;
140 static const struct file_operations aa_fs_profile_remove = {
141 .write = profile_remove,
142 .llseek = default_llseek,
145 /** Base file system setup **/
147 static struct dentry *aa_fs_dentry __initdata;
149 static void __init aafs_remove(const char *name)
151 struct dentry *dentry;
153 dentry = lookup_one_len(name, aa_fs_dentry, strlen(name));
154 if (!IS_ERR(dentry)) {
155 securityfs_remove(dentry);
156 dput(dentry);
161 * aafs_create - create an entry in the apparmor filesystem
162 * @name: name of the entry (NOT NULL)
163 * @mask: file permission mask of the file
164 * @fops: file operations for the file (NOT NULL)
166 * Used aafs_remove to remove entries created with this fn.
168 static int __init aafs_create(const char *name, int mask,
169 const struct file_operations *fops)
171 struct dentry *dentry;
173 dentry = securityfs_create_file(name, S_IFREG | mask, aa_fs_dentry,
174 NULL, fops);
176 return IS_ERR(dentry) ? PTR_ERR(dentry) : 0;
180 * aa_destroy_aafs - cleanup and free aafs
182 * releases dentries allocated by aa_create_aafs
184 void __init aa_destroy_aafs(void)
186 if (aa_fs_dentry) {
187 aafs_remove(".remove");
188 aafs_remove(".replace");
189 aafs_remove(".load");
191 securityfs_remove(aa_fs_dentry);
192 aa_fs_dentry = NULL;
197 * aa_create_aafs - create the apparmor security filesystem
199 * dentries created here are released by aa_destroy_aafs
201 * Returns: error on failure
203 int __init aa_create_aafs(void)
205 int error;
207 if (!apparmor_initialized)
208 return 0;
210 if (aa_fs_dentry) {
211 AA_ERROR("%s: AppArmor securityfs already exists\n", __func__);
212 return -EEXIST;
215 aa_fs_dentry = securityfs_create_dir("apparmor", NULL);
216 if (IS_ERR(aa_fs_dentry)) {
217 error = PTR_ERR(aa_fs_dentry);
218 aa_fs_dentry = NULL;
219 goto error;
222 error = aafs_create(".load", 0640, &aa_fs_profile_load);
223 if (error)
224 goto error;
225 error = aafs_create(".replace", 0640, &aa_fs_profile_replace);
226 if (error)
227 goto error;
228 error = aafs_create(".remove", 0640, &aa_fs_profile_remove);
229 if (error)
230 goto error;
232 /* TODO: add support for apparmorfs_null and apparmorfs_mnt */
234 /* Report that AppArmor fs is enabled */
235 aa_info_message("AppArmor Filesystem Enabled");
236 return 0;
238 error:
239 aa_destroy_aafs();
240 AA_ERROR("Error creating AppArmor securityfs\n");
241 return error;
244 fs_initcall(aa_create_aafs);