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 */
aa_split_fqname(char * fqname,char ** ns_name)38 char *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 */
aa_info_message(const char * str)64 void aa_info_message(const char *str)
65 {
66 if (audit_enabled) {
67 struct common_audit_data sa;
68 struct apparmor_audit_data aad = {0,};
69 COMMON_AUDIT_DATA_INIT(&sa, NONE);
70 sa.aad = &aad;
71 aad.info = str;
72 aa_audit_msg(AUDIT_APPARMOR_STATUS, &sa, NULL);
73 }
74 printk(KERN_INFO "AppArmor: %s\n", str);
75 }
76
77 /**
78 * kvmalloc - do allocation preferring kmalloc but falling back to vmalloc
79 * @size: size of allocation
80 *
81 * Return: allocated buffer or NULL if failed
82 *
83 * It is possible that policy being loaded from the user is larger than
84 * what can be allocated by kmalloc, in those cases fall back to vmalloc.
85 */
kvmalloc(size_t size)86 void *kvmalloc(size_t size)
87 {
88 void *buffer = NULL;
89
90 if (size == 0)
91 return NULL;
92
93 /* do not attempt kmalloc if we need more than 16 pages at once */
94 if (size <= (16*PAGE_SIZE))
95 buffer = kmalloc(size, GFP_NOIO | __GFP_NOWARN);
96 if (!buffer) {
97 /* see kvfree for why size must be at least work_struct size
98 * when allocated via vmalloc
99 */
100 if (size < sizeof(struct work_struct))
101 size = sizeof(struct work_struct);
102 buffer = vmalloc(size);
103 }
104 return buffer;
105 }
106
107 /**
108 * do_vfree - workqueue routine for freeing vmalloced memory
109 * @work: data to be freed
110 *
111 * The work_struct is overlaid to the data being freed, as at the point
112 * the work is scheduled the data is no longer valid, be its freeing
113 * needs to be delayed until safe.
114 */
do_vfree(struct work_struct * work)115 static void do_vfree(struct work_struct *work)
116 {
117 vfree(work);
118 }
119
120 /**
121 * kvfree - free an allocation do by kvmalloc
122 * @buffer: buffer to free (MAYBE_NULL)
123 *
124 * Free a buffer allocated by kvmalloc
125 */
kvfree(void * buffer)126 void kvfree(void *buffer)
127 {
128 if (is_vmalloc_addr(buffer)) {
129 /* Data is no longer valid so just use the allocated space
130 * as the work_struct
131 */
132 struct work_struct *work = (struct work_struct *) buffer;
133 INIT_WORK(work, do_vfree);
134 schedule_work(work);
135 } else
136 kfree(buffer);
137 }
138