/*
* AppArmor security module
*
* This file contains AppArmor lib definitions
*
* 2017 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.
*/
#ifndef __AA_LIB_H
#define __AA_LIB_H
#include <linux/slab.h>
#include <linux/fs.h>
#include "match.h"
/* Provide our own test for whether a write lock is held for asserts
* this is because on none SMP systems write_can_lock will always
* resolve to true, which is what you want for code making decisions
* based on it, but wrong for asserts checking that the lock is held
*/
#ifdef CONFIG_SMP
#define write_is_locked(X) !write_can_lock(X)
#else
#define write_is_locked(X) (1)
#endif /* CONFIG_SMP */
/*
* DEBUG remains global (no per profile flag) since it is mostly used in sysctl
* which is not related to profile accesses.
*/
#define DEBUG_ON (aa_g_debug)
#define dbg_printk(__fmt, __args...) pr_debug(__fmt, ##__args)
#define AA_DEBUG(fmt, args...) \
do { \
if (DEBUG_ON) \
pr_debug_ratelimited("AppArmor: " fmt, ##args); \
} while (0)
#define AA_WARN(X) WARN((X), "APPARMOR WARN %s: %s\n", __func__, #X)
#define AA_BUG(X, args...) AA_BUG_FMT((X), "" args)
#ifdef CONFIG_SECURITY_APPARMOR_DEBUG_ASSERTS
#define AA_BUG_FMT(X, fmt, args...) \
WARN((X), "AppArmor WARN %s: (" #X "): " fmt, __func__, ##args)
#else
#define AA_BUG_FMT(X, fmt, args...)
#endif
#define AA_ERROR(fmt, args...) \
pr_err_ratelimited("AppArmor: " fmt, ##args)
/* Flag indicating whether initialization completed */
extern int apparmor_initialized __initdata;
/* fn's in lib */
char *aa_split_fqname(char *args, char **ns_name);
const char *aa_splitn_fqname(const char *fqname, size_t n, const char **ns_name,
size_t *ns_len);
void aa_info_message(const char *str);
void *__aa_kvmalloc(size_t size, gfp_t flags);
static inline void *kvmalloc(size_t size)
{
return __aa_kvmalloc(size, 0);
}
static inline void *kvzalloc(size_t size)
{
return __aa_kvmalloc(size, __GFP_ZERO);
}
/* returns 0 if kref not incremented */
static inline int kref_get_not0(struct kref *kref)
{
return atomic_inc_not_zero(&kref->refcount);
}
/**
* aa_strneq - compare null terminated @str to a non null terminated substring
* @str: a null terminated string
* @sub: a substring, not necessarily null terminated
* @len: length of @sub to compare
*
* The @str string must be full consumed for this to be considered a match
*/
static inline bool aa_strneq(const char *str, const char *sub, int len)
{
return !strncmp(str, sub, len) && !str[len];
}
/**
* aa_dfa_null_transition - step to next state after null character
* @dfa: the dfa to match against
* @start: the state of the dfa to start matching in
*
* aa_dfa_null_transition transitions to the next state after a null
* character which is not used in standard matching and is only
* used to separate pairs.
*/
static inline unsigned int aa_dfa_null_transition(struct aa_dfa *dfa,
unsigned int start)
{
/* the null transition only needs the string's null terminator byte */
return aa_dfa_next(dfa, start, 0);
}
static inline bool path_mediated_fs(struct dentry *dentry)
{
return !(dentry->d_sb->s_flags & MS_NOUSER);
}
/* struct aa_policy - common part of both namespaces and profiles
* @name: name of the object
* @hname - The hierarchical name
* @list: list policy object is on
* @profiles: head of the profiles list contained in the object
*/
struct aa_policy {
char *name;
char *hname;
struct list_head list;
struct list_head profiles;
};
/**
* hname_tail - find the last component of an hname
* @name: hname to find the base profile name component of (NOT NULL)
*
* Returns: the tail (base profile name) name component of an hname
*/
static inline const char *hname_tail(const char *hname)
{
char *split;
hname = strim((char *)hname);
for (split = strstr(hname, "//"); split; split = strstr(hname, "//"))
hname = split + 2;
return hname;
}
/**
* __policy_find - find a policy by @name on a policy list
* @head: list to search (NOT NULL)
* @name: name to search for (NOT NULL)
*
* Requires: rcu_read_lock be held
*
* Returns: unrefcounted policy that match @name or NULL if not found
*/
static inline struct aa_policy *__policy_find(struct list_head *head,
const char *name)
{
struct aa_policy *policy;
list_for_each_entry_rcu(policy, head, list) {
if (!strcmp(policy->name, name))
return policy;
}
return NULL;
}
/**
* __policy_strn_find - find a policy that's name matches @len chars of @str
* @head: list to search (NOT NULL)
* @str: string to search for (NOT NULL)
* @len: length of match required
*
* Requires: rcu_read_lock be held
*
* Returns: unrefcounted policy that match @str or NULL if not found
*
* if @len == strlen(@strlen) then this is equiv to __policy_find
* other wise it allows searching for policy by a partial match of name
*/
static inline struct aa_policy *__policy_strn_find(struct list_head *head,
const char *str, int len)
{
struct aa_policy *policy;
list_for_each_entry_rcu(policy, head, list) {
if (aa_strneq(policy->name, str, len))
return policy;
}
return NULL;
}
bool aa_policy_init(struct aa_policy *policy, const char *prefix,
const char *name);
void aa_policy_destroy(struct aa_policy *policy);
#endif /* AA_LIB_H */
