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1/*
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
15#include <linux/mm.h>
16#include <linux/slab.h>
17#include <linux/string.h>
18#include <linux/vmalloc.h>
19
20#include "include/audit.h"
21#include "include/apparmor.h"
22
23
24/**
25 * aa_split_fqname - split a fqname into a profile and namespace name
26 * @fqname: a full qualified name in namespace profile format (NOT NULL)
27 * @ns_name: pointer to portion of the string containing the ns name (NOT NULL)
28 *
29 * Returns: profile name or NULL if one is not specified
30 *
31 * Split a namespace name from a profile name (see policy.c for naming
32 * description). If a portion of the name is missing it returns NULL for
33 * that portion.
34 *
35 * NOTE: may modify the @fqname string. The pointers returned point
36 * into the @fqname string.
37 */
38char *aa_split_fqname(char *fqname, char **ns_name)
39{
40 char *name = strim(fqname);
41
42 *ns_name = NULL;
43 if (name[0] == ':') {
44 char *split = strchr(&name[1], ':');
45 *ns_name = skip_spaces(&name[1]);
46 if (split) {
47 /* overwrite ':' with \0 */
48 *split = 0;
49 name = skip_spaces(split + 1);
50 } else
51 /* a ns name without a following profile is allowed */
52 name = NULL;
53 }
54 if (name && *name == 0)
55 name = NULL;
56
57 return name;
58}
59
60/**
61 * aa_info_message - log a none profile related status message
62 * @str: message to log
63 */
64void aa_info_message(const char *str)
65{
66 if (audit_enabled) {
67 struct common_audit_data sa;
68 COMMON_AUDIT_DATA_INIT(&sa, NONE);
69 sa.aad.info = str;
70 aa_audit_msg(AUDIT_APPARMOR_STATUS, &sa, NULL);
71 }
72 printk(KERN_INFO "AppArmor: %s\n", str);
73}
74
75/**
76 * kvmalloc - do allocation preferring kmalloc but falling back to vmalloc
77 * @size: size of allocation
78 *
79 * Return: allocated buffer or NULL if failed
80 *
81 * It is possible that policy being loaded from the user is larger than
82 * what can be allocated by kmalloc, in those cases fall back to vmalloc.
83 */
84void *kvmalloc(size_t size)
85{
86 void *buffer = NULL;
87
88 if (size == 0)
89 return NULL;
90
91 /* do not attempt kmalloc if we need more than 16 pages at once */
92 if (size <= (16*PAGE_SIZE))
93 buffer = kmalloc(size, GFP_NOIO | __GFP_NOWARN);
94 if (!buffer) {
95 /* see kvfree for why size must be at least work_struct size
96 * when allocated via vmalloc
97 */
98 if (size < sizeof(struct work_struct))
99 size = sizeof(struct work_struct);
100 buffer = vmalloc(size);
101 }
102 return buffer;
103}
104
105/**
106 * do_vfree - workqueue routine for freeing vmalloced memory
107 * @work: data to be freed
108 *
109 * The work_struct is overlaid to the data being freed, as at the point
110 * the work is scheduled the data is no longer valid, be its freeing
111 * needs to be delayed until safe.
112 */
113static void do_vfree(struct work_struct *work)
114{
115 vfree(work);
116}
117
118/**
119 * kvfree - free an allocation do by kvmalloc
120 * @buffer: buffer to free (MAYBE_NULL)
121 *
122 * Free a buffer allocated by kvmalloc
123 */
124void kvfree(void *buffer)
125{
126 if (is_vmalloc_addr(buffer)) {
127 /* Data is no longer valid so just use the allocated space
128 * as the work_struct
129 */
130 struct work_struct *work = (struct work_struct *) buffer;
131 INIT_WORK(work, do_vfree);
132 schedule_work(work);
133 } else
134 kfree(buffer);
135}