blob: b82e383beb77937b8b001bc5da67876cde0c4aba [file] [log] [blame]
John Johansencdff2642010-07-29 14:47:57 -07001/*
2 * AppArmor security module
3 *
4 * This file contains basic common functions used in AppArmor
5 *
6 * Copyright (C) 1998-2008 Novell/SUSE
7 * Copyright 2009-2010 Canonical Ltd.
8 *
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.
13 */
14
Alexey Dobriyanb7f080c2011-06-16 11:01:34 +000015#include <linux/mm.h>
John Johansencdff2642010-07-29 14:47:57 -070016#include <linux/slab.h>
17#include <linux/string.h>
18#include <linux/vmalloc.h>
19
20#include "include/audit.h"
21
22
23/**
24 * aa_split_fqname - split a fqname into a profile and namespace name
25 * @fqname: a full qualified name in namespace profile format (NOT NULL)
26 * @ns_name: pointer to portion of the string containing the ns name (NOT NULL)
27 *
28 * Returns: profile name or NULL if one is not specified
29 *
30 * Split a namespace name from a profile name (see policy.c for naming
31 * description). If a portion of the name is missing it returns NULL for
32 * that portion.
33 *
34 * NOTE: may modify the @fqname string. The pointers returned point
35 * into the @fqname string.
36 */
37char *aa_split_fqname(char *fqname, char **ns_name)
38{
39 char *name = strim(fqname);
40
41 *ns_name = NULL;
42 if (name[0] == ':') {
43 char *split = strchr(&name[1], ':');
John Johansen04ccd532010-08-27 18:33:28 -070044 *ns_name = skip_spaces(&name[1]);
John Johansencdff2642010-07-29 14:47:57 -070045 if (split) {
46 /* overwrite ':' with \0 */
47 *split = 0;
48 name = skip_spaces(split + 1);
49 } else
50 /* a ns name without a following profile is allowed */
51 name = NULL;
John Johansencdff2642010-07-29 14:47:57 -070052 }
53 if (name && *name == 0)
54 name = NULL;
55
56 return name;
57}
58
59/**
60 * aa_info_message - log a none profile related status message
61 * @str: message to log
62 */
63void aa_info_message(const char *str)
64{
65 if (audit_enabled) {
66 struct common_audit_data sa;
67 COMMON_AUDIT_DATA_INIT(&sa, NONE);
68 sa.aad.info = str;
69 aa_audit_msg(AUDIT_APPARMOR_STATUS, &sa, NULL);
70 }
71 printk(KERN_INFO "AppArmor: %s\n", str);
72}
73
74/**
75 * kvmalloc - do allocation preferring kmalloc but falling back to vmalloc
76 * @size: size of allocation
77 *
78 * Return: allocated buffer or NULL if failed
79 *
80 * It is possible that policy being loaded from the user is larger than
81 * what can be allocated by kmalloc, in those cases fall back to vmalloc.
82 */
83void *kvmalloc(size_t size)
84{
85 void *buffer = NULL;
86
87 if (size == 0)
88 return NULL;
89
90 /* do not attempt kmalloc if we need more than 16 pages at once */
91 if (size <= (16*PAGE_SIZE))
92 buffer = kmalloc(size, GFP_NOIO | __GFP_NOWARN);
93 if (!buffer) {
94 /* see kvfree for why size must be at least work_struct size
95 * when allocated via vmalloc
96 */
97 if (size < sizeof(struct work_struct))
98 size = sizeof(struct work_struct);
99 buffer = vmalloc(size);
100 }
101 return buffer;
102}
103
104/**
105 * do_vfree - workqueue routine for freeing vmalloced memory
106 * @work: data to be freed
107 *
108 * The work_struct is overlaid to the data being freed, as at the point
109 * the work is scheduled the data is no longer valid, be its freeing
110 * needs to be delayed until safe.
111 */
112static void do_vfree(struct work_struct *work)
113{
114 vfree(work);
115}
116
117/**
118 * kvfree - free an allocation do by kvmalloc
119 * @buffer: buffer to free (MAYBE_NULL)
120 *
121 * Free a buffer allocated by kvmalloc
122 */
123void kvfree(void *buffer)
124{
125 if (is_vmalloc_addr(buffer)) {
126 /* Data is no longer valid so just use the allocated space
127 * as the work_struct
128 */
129 struct work_struct *work = (struct work_struct *) buffer;
130 INIT_WORK(work, do_vfree);
131 schedule_work(work);
132 } else
133 kfree(buffer);
134}