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/*
* AppArmor security module
*
* This file contains basic common functions used in AppArmor
*
* Copyright (C) 1998-2008 Novell/SUSE
* Copyright 2009-2010 Canonical Ltd.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation, version 2 of the
* License.
*/
#include <linux/ctype.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/vmalloc.h>
#include "include/audit.h"
#include "include/apparmor.h"
#include "include/lib.h"
#include "include/policy.h"
/**
* aa_split_fqname - split a fqname into a profile and namespace name
* @fqname: a full qualified name in namespace profile format (NOT NULL)
* @ns_name: pointer to portion of the string containing the ns name (NOT NULL)
*
* Returns: profile name or NULL if one is not specified
*
* Split a namespace name from a profile name (see policy.c for naming
* description). If a portion of the name is missing it returns NULL for
* that portion.
*
* NOTE: may modify the @fqname string. The pointers returned point
* into the @fqname string.
*/
char *aa_split_fqname(char *fqname, char **ns_name)
{
char *name = strim(fqname);
*ns_name = NULL;
if (name[0] == ':') {
char *split = strchr(&name[1], ':');
*ns_name = skip_spaces(&name[1]);
if (split) {
/* overwrite ':' with \0 */
*split++ = 0;
if (strncmp(split, "//", 2) == 0)
split += 2;
name = skip_spaces(split);
} else
/* a ns name without a following profile is allowed */
name = NULL;
}
if (name && *name == 0)
name = NULL;
return name;
}
/**
* skipn_spaces - Removes leading whitespace from @str.
* @str: The string to be stripped.
*
* Returns a pointer to the first non-whitespace character in @str.
* if all whitespace will return NULL
*/
static const char *skipn_spaces(const char *str, size_t n)
{
for (; n && isspace(*str); --n)
++str;
if (n)
return (char *)str;
return NULL;
}
const char *aa_splitn_fqname(const char *fqname, size_t n, const char **ns_name,
size_t *ns_len)
{
const char *end = fqname + n;
const char *name = skipn_spaces(fqname, n);
if (!name)
return NULL;
*ns_name = NULL;
*ns_len = 0;
if (name[0] == ':') {
char *split = strnchr(&name[1], end - &name[1], ':');
*ns_name = skipn_spaces(&name[1], end - &name[1]);
if (!*ns_name)
return NULL;
if (split) {
*ns_len = split - *ns_name;
if (*ns_len == 0)
*ns_name = NULL;
split++;
if (end - split > 1 && strncmp(split, "//", 2) == 0)
split += 2;
name = skipn_spaces(split, end - split);
} else {
/* a ns name without a following profile is allowed */
name = NULL;
*ns_len = end - *ns_name;
}
}
if (name && *name == 0)
name = NULL;
return name;
}
/**
* aa_info_message - log a none profile related status message
* @str: message to log
*/
void aa_info_message(const char *str)
{
if (audit_enabled) {
struct common_audit_data sa;
struct apparmor_audit_data aad = {0,};
sa.type = LSM_AUDIT_DATA_NONE;
sa.aad = &aad;
aad.info = str;
aa_audit_msg(AUDIT_APPARMOR_STATUS, &sa, NULL);
}
printk(KERN_INFO "AppArmor: %s\n", str);
}
/**
* __aa_kvmalloc - do allocation preferring kmalloc but falling back to vmalloc
* @size: how many bytes of memory are required
* @flags: the type of memory to allocate (see kmalloc).
*
* Return: allocated buffer or NULL if failed
*
* It is possible that policy being loaded from the user is larger than
* what can be allocated by kmalloc, in those cases fall back to vmalloc.
*/
void *__aa_kvmalloc(size_t size, gfp_t flags)
{
void *buffer = NULL;
if (size == 0)
return NULL;
/* do not attempt kmalloc if we need more than 16 pages at once */
if (size <= (16*PAGE_SIZE))
buffer = kmalloc(size, flags | GFP_KERNEL | __GFP_NORETRY |
__GFP_NOWARN);
if (!buffer) {
if (flags & __GFP_ZERO)
buffer = vzalloc(size);
else
buffer = vmalloc(size);
}
return buffer;
}
/**
* aa_policy_init - initialize a policy structure
* @policy: policy to initialize (NOT NULL)
* @prefix: prefix name if any is required. (MAYBE NULL)
* @name: name of the policy, init will make a copy of it (NOT NULL)
*
* Note: this fn creates a copy of strings passed in
*
* Returns: true if policy init successful
*/
bool aa_policy_init(struct aa_policy *policy, const char *prefix,
const char *name)
{
/* freed by policy_free */
if (prefix) {
policy->hname = kmalloc(strlen(prefix) + strlen(name) + 3,
GFP_KERNEL);
if (policy->hname)
sprintf(policy->hname, "%s//%s", prefix, name);
} else
policy->hname = kstrdup(name, GFP_KERNEL);
if (!policy->hname)
return 0;
/* base.name is a substring of fqname */
policy->name = (char *)hname_tail(policy->hname);
INIT_LIST_HEAD(&policy->list);
INIT_LIST_HEAD(&policy->profiles);
return 1;
}
/**
* aa_policy_destroy - free the elements referenced by @policy
* @policy: policy that is to have its elements freed (NOT NULL)
*/
void aa_policy_destroy(struct aa_policy *policy)
{
/* still contains profiles -- invalid */
if (on_list_rcu(&policy->profiles)) {
AA_ERROR("%s: internal error, policy '%s' contains profiles\n",
__func__, policy->name);
}
if (on_list_rcu(&policy->list)) {
AA_ERROR("%s: internal error, policy '%s' still on list\n",
__func__, policy->name);
}
/* don't free name as its a subset of hname */
kzfree(policy->hname);
}
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