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label.h 12.24 KiB
/*
* AppArmor security module
*
* This file contains AppArmor label definitions
*
* Copyright 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_LABEL_H
#define __AA_LABEL_H
#include <linux/atomic.h>
#include <linux/audit.h>
#include <linux/rbtree.h>
#include <linux/rcupdate.h>
#include "apparmor.h"
#include "lib.h"
struct aa_ns;
#define LOCAL_VEC_ENTRIES 8
#define DEFINE_VEC(T, V) \
struct aa_ ## T *(_ ## V ## _localtmp)[LOCAL_VEC_ENTRIES]; \
struct aa_ ## T **(V)
#define vec_setup(T, V, N, GFP) \
({ \
if ((N) <= LOCAL_VEC_ENTRIES) { \
typeof(N) i; \
(V) = (_ ## V ## _localtmp); \
for (i = 0; i < (N); i++) \
(V)[i] = NULL; \
} else \
(V) = kzalloc(sizeof(struct aa_ ## T *) * (N), (GFP)); \
(V) ? 0 : -ENOMEM; \
})
#define vec_cleanup(T, V, N) \
do { \
int i; \
for (i = 0; i < (N); i++) { \
if (!IS_ERR_OR_NULL((V)[i])) \
aa_put_ ## T((V)[i]); \
} \
if ((V) != _ ## V ## _localtmp) \
kfree(V); \
} while (0)
#define vec_last(VEC, SIZE) ((VEC)[(SIZE) - 1])
#define vec_ns(VEC, SIZE) (vec_last((VEC), (SIZE))->ns)
#define vec_labelset(VEC, SIZE) (&vec_ns((VEC), (SIZE))->labels)
#define cleanup_domain_vec(V, L) cleanup_label_vec((V), (L)->size)
struct aa_profile;
#define VEC_FLAG_TERMINATE 1
int aa_vec_unique(struct aa_profile **vec, int n, int flags);
struct aa_label *aa_vec_find_or_create_label(struct aa_profile **vec, int len,
gfp_t gfp);
#define aa_sort_and_merge_vec(N, V) \
aa_sort_and_merge_profiles((N), (struct aa_profile **)(V))
/* struct aa_labelset - set of labels for a namespace
* * Labels are reference counted; aa_labelset does not contribute to label
* reference counts. Once a label's last refcount is put it is removed from
* the set.
*/
struct aa_labelset {
rwlock_t lock;
struct rb_root root;
};
#define __labelset_for_each(LS, N) \
for ((N) = rb_first(&(LS)->root); (N); (N) = rb_next(N))
void aa_labelset_destroy(struct aa_labelset *ls);
void aa_labelset_init(struct aa_labelset *ls);
enum label_flags {
FLAG_HAT = 1, /* profile is a hat */
FLAG_UNCONFINED = 2, /* label unconfined only if all */
FLAG_NULL = 4, /* profile is null learning profile */
FLAG_IX_ON_NAME_ERROR = 8, /* fallback to ix on name lookup fail */
FLAG_IMMUTIBLE = 0x10, /* don't allow changes/replacement */
FLAG_USER_DEFINED = 0x20, /* user based profile - lower privs */
FLAG_NO_LIST_REF = 0x40, /* list doesn't keep profile ref */
FLAG_NS_COUNT = 0x80, /* carries NS ref count */
FLAG_IN_TREE = 0x100, /* label is in tree */
FLAG_PROFILE = 0x200, /* label is a profile */
FLAG_EXPLICIT = 0x400, /* explicit static label */
FLAG_STALE = 0x800, /* replaced/removed */
FLAG_RENAMED = 0x1000, /* label has renaming in it */
FLAG_REVOKED = 0x2000, /* label has revocation in it */
/* These flags must correspond with PATH_flags */
/* TODO: add new path flags */
};
struct aa_label;
struct aa_proxy {
struct kref count;
struct aa_label __rcu *label;
};
struct label_it {
int i, j;
};
/* struct aa_label - lazy labeling struct
* @count: ref count of active users
* @node: rbtree position
* @rcu: rcu callback struct
* @proxy: is set to the label that replaced this label
* @hname: text representation of the label (MAYBE_NULL)
* @flags: stale and other flags - values may change under label set lock
* @secid: secid that references this label
* @size: number of entries in @ent[]
* @ent: set of profiles for label, actual size determined by @size
*/
struct aa_label {
struct kref count;
struct rb_node node;
struct rcu_head rcu;
struct aa_proxy *proxy;
__counted char *hname;
long flags;
u32 secid;
int size;
struct aa_profile *vec[];
};
#define last_error(E, FN) \
do { \
int __subE = (FN); \
if (__subE) \
(E) = __subE; \
} while (0)
#define label_isprofile(X) ((X)->flags & FLAG_PROFILE)
#define label_unconfined(X) ((X)->flags & FLAG_UNCONFINED)
#define unconfined(X) label_unconfined(X)
#define label_is_stale(X) ((X)->flags & FLAG_STALE)
#define __label_make_stale(X) ((X)->flags |= FLAG_STALE)
#define labels_ns(X) (vec_ns(&((X)->vec[0]), (X)->size))
#define labels_set(X) (&labels_ns(X)->labels)
#define labels_profile(X) ((X)->vec[(X)->size - 1])
int aa_label_next_confined(struct aa_label *l, int i);
/* for each profile in a label */
#define label_for_each(I, L, P) \
for ((I).i = 0; ((P) = (L)->vec[(I).i]); ++((I).i))
/* assumes break/goto ended label_for_each */
#define label_for_each_cont(I, L, P) \
for (++((I).i); ((P) = (L)->vec[(I).i]); ++((I).i))
#define next_comb(I, L1, L2) \
do { \
(I).j++; \
if ((I).j >= (L2)->size) { \
(I).i++; \
(I).j = 0; \
} \
} while (0)
/* for each combination of P1 in L1, and P2 in L2 */
#define label_for_each_comb(I, L1, L2, P1, P2) \
for ((I).i = (I).j = 0; \
((P1) = (L1)->vec[(I).i]) && ((P2) = (L2)->vec[(I).j]); \
(I) = next_comb(I, L1, L2))
#define fn_for_each_comb(L1, L2, P1, P2, FN) \
({ \
struct label_it i; \
int __E = 0; \
label_for_each_comb(i, (L1), (L2), (P1), (P2)) { \
last_error(__E, (FN)); \
} \
__E; \
})
/* for each profile that is enforcing confinement in a label */
#define label_for_each_confined(I, L, P) \
for ((I).i = aa_label_next_confined((L), 0); \
((P) = (L)->vec[(I).i]); \
(I).i = aa_label_next_confined((L), (I).i + 1))
#define label_for_each_in_merge(I, A, B, P) \
for ((I).i = (I).j = 0; \
((P) = aa_label_next_in_merge(&(I), (A), (B))); \
)
#define label_for_each_not_in_set(I, SET, SUB, P) \
for ((I).i = (I).j = 0; \
((P) = __aa_label_next_not_in_set(&(I), (SET), (SUB))); \
)
#define next_in_ns(i, NS, L) \({ \
typeof(i) ___i = (i); \
while ((L)->vec[___i] && (L)->vec[___i]->ns != (NS)) \
(___i)++; \
(___i); \
})
#define label_for_each_in_ns(I, NS, L, P) \
for ((I).i = next_in_ns(0, (NS), (L)); \
((P) = (L)->vec[(I).i]); \
(I).i = next_in_ns((I).i + 1, (NS), (L)))
#define fn_for_each_in_ns(L, P, FN) \
({ \
struct label_it __i; \
struct aa_ns *__ns = labels_ns(L); \
int __E = 0; \
label_for_each_in_ns(__i, __ns, (L), (P)) { \
last_error(__E, (FN)); \
} \
__E; \
})
#define fn_for_each_XXX(L, P, FN, ...) \
({ \
struct label_it i; \
int __E = 0; \
label_for_each ## __VA_ARGS__(i, (L), (P)) { \
last_error(__E, (FN)); \
} \
__E; \
})
#define fn_for_each(L, P, FN) fn_for_each_XXX(L, P, FN)
#define fn_for_each_confined(L, P, FN) fn_for_each_XXX(L, P, FN, _confined)
#define fn_for_each2_XXX(L1, L2, P, FN, ...) \
({ \
struct label_it i; \
int __E = 0; \
label_for_each ## __VA_ARGS__(i, (L1), (L2), (P)) { \
last_error(__E, (FN)); \
} \
__E; \
})
#define fn_for_each_in_merge(L1, L2, P, FN) \
fn_for_each2_XXX((L1), (L2), P, FN, _in_merge)
#define fn_for_each_not_in_set(L1, L2, P, FN) \
fn_for_each2_XXX((L1), (L2), P, FN, _not_in_set)
#define LABEL_MEDIATES(L, C) \
({ \
struct aa_profile *profile; \
struct label_it i; \
int ret = 0; \
label_for_each(i, (L), profile) { \
if (PROFILE_MEDIATES(profile, (C))) { \
ret = 1; \
break; \
} \
} \
ret; \
})
void aa_labelset_destroy(struct aa_labelset *ls);
void aa_labelset_init(struct aa_labelset *ls);
void __aa_labelset_update_subtree(struct aa_ns *ns);
void aa_label_free(struct aa_label *label);
void aa_label_kref(struct kref *kref);
bool aa_label_init(struct aa_label *label, int size);
struct aa_label *aa_label_alloc(int size, struct aa_proxy *proxy, gfp_t gfp);
bool aa_label_is_subset(struct aa_label *set, struct aa_label *sub);
struct aa_profile *__aa_label_next_not_in_set(struct label_it *I,
struct aa_label *set,
struct aa_label *sub);
bool aa_label_remove(struct aa_label *label);
struct aa_label *aa_label_insert(struct aa_labelset *ls, struct aa_label *l);
bool aa_label_replace(struct aa_label *old, struct aa_label *new);
bool aa_label_make_newest(struct aa_labelset *ls, struct aa_label *old,
struct aa_label *new);
struct aa_label *aa_label_find(struct aa_label *l);
struct aa_profile *aa_label_next_in_merge(struct label_it *I,
struct aa_label *a,
struct aa_label *b);
struct aa_label *aa_label_find_merge(struct aa_label *a, struct aa_label *b);
struct aa_label *aa_label_merge(struct aa_label *a, struct aa_label *b,
gfp_t gfp);
bool aa_update_label_name(struct aa_ns *ns, struct aa_label *label, gfp_t gfp);
#define FLAGS_NONE 0
#define FLAG_SHOW_MODE 1
#define FLAG_VIEW_SUBNS 2
#define FLAG_HIDDEN_UNCONFINED 4
#define FLAG_ABS_ROOT 8
int aa_label_snxprint(char *str, size_t size, struct aa_ns *view,
struct aa_label *label, int flags);
int aa_label_asxprint(char **strp, struct aa_ns *ns, struct aa_label *label,
int flags, gfp_t gfp);
int aa_label_acntsxprint(char __counted **strp, struct aa_ns *ns,
struct aa_label *label, int flags, gfp_t gfp);
void aa_label_xaudit(struct audit_buffer *ab, struct aa_ns *ns,
struct aa_label *label, int flags, gfp_t gfp);
void aa_label_seq_xprint(struct seq_file *f, struct aa_ns *ns,
struct aa_label *label, int flags, gfp_t gfp);
void aa_label_xprintk(struct aa_ns *ns, struct aa_label *label, int flags,
gfp_t gfp);
void aa_label_audit(struct audit_buffer *ab, struct aa_label *label, gfp_t gfp);
void aa_label_seq_print(struct seq_file *f, struct aa_label *label, gfp_t gfp);
void aa_label_printk(struct aa_label *label, gfp_t gfp);
struct aa_label *aa_label_parse(struct aa_label *base, const char *str,
gfp_t gfp, bool create, bool force_stack);
struct aa_perms;
int aa_label_match(struct aa_profile *profile, struct aa_label *label,
unsigned int state, bool subns, u32 request,
struct aa_perms *perms);
/**
* __aa_get_label - get a reference count to uncounted label reference
* @l: reference to get a count on
*
* Returns: pointer to reference OR NULL if race is lost and reference is
* being repeated.
* Requires: lock held, and the return code MUST be checked
*/
static inline struct aa_label *__aa_get_label(struct aa_label *l)
{
if (l && kref_get_unless_zero(&l->count)) return l;
return NULL;
}
static inline struct aa_label *aa_get_label(struct aa_label *l)
{
if (l)
kref_get(&(l->count));
return l;
}
/**
* aa_get_label_rcu - increment refcount on a label that can be replaced
* @l: pointer to label that can be replaced (NOT NULL)
*
* Returns: pointer to a refcounted label.
* else NULL if no label
*/
static inline struct aa_label *aa_get_label_rcu(struct aa_label __rcu **l)
{
struct aa_label *c;
rcu_read_lock();
do {
c = rcu_dereference(*l);
} while (c && !kref_get_unless_zero(&c->count));
rcu_read_unlock();
return c;
}
/**
* aa_get_newest_label - find the newest version of @l
* @l: the label to check for newer versions of
*
* Returns: refcounted newest version of @l taking into account
* replacement, renames and removals
* return @l.
*/
static inline struct aa_label *aa_get_newest_label(struct aa_label *l)
{
if (!l)
return NULL;
if (label_is_stale(l)) {
struct aa_label *tmp;
AA_BUG(!l->proxy);
AA_BUG(!l->proxy->label);
/* BUG: only way this can happen is @l ref count and its
* replacement count have gone to 0 and are on their way
* to destruction. ie. we have a refcounting error
*/
tmp = aa_get_label_rcu(&l->proxy->label);
AA_BUG(!tmp);
return tmp;
}
return aa_get_label(l);
}
static inline void aa_put_label(struct aa_label *l)
{
if (l)
kref_put(&l->count, aa_label_kref);
}
struct aa_proxy *aa_alloc_proxy(struct aa_label *l, gfp_t gfp);
void aa_proxy_kref(struct kref *kref);
static inline struct aa_proxy *aa_get_proxy(struct aa_proxy *proxy)
{
if (proxy)
kref_get(&(proxy->count));
return proxy;
}
static inline void aa_put_proxy(struct aa_proxy *proxy)
{
if (proxy)
kref_put(&proxy->count, aa_proxy_kref);
}
void __aa_proxy_redirect(struct aa_label *orig, struct aa_label *new);
#endif /* __AA_LABEL_H */