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1/*
2 * AppArmor security module
3 *
4 * This file contains AppArmor policy dfa matching engine definitions.
5 *
6 * Copyright (C) 1998-2008 Novell/SUSE
7 * Copyright 2009-2012 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#ifndef __AA_MATCH_H
16#define __AA_MATCH_H
17
18#include <linux/kref.h>
19
20#define DFA_NOMATCH 0
21#define DFA_START 1
22
23
24/**
25 * The format used for transition tables is based on the GNU flex table
26 * file format (--tables-file option; see Table File Format in the flex
27 * info pages and the flex sources for documentation). The magic number
28 * used in the header is 0x1B5E783D instead of 0xF13C57B1 though, because
29 * new tables have been defined and others YY_ID_CHK (check) and YY_ID_DEF
30 * (default) tables are used slightly differently (see the apparmor-parser
31 * package).
32 *
33 *
34 * The data in the packed dfa is stored in network byte order, and the tables
35 * are arranged for flexibility. We convert the table data to host native
36 * byte order.
37 *
38 * The dfa begins with a table set header, and is followed by the actual
39 * tables.
40 */
41
42#define YYTH_MAGIC 0x1B5E783D
43
44struct table_set_header {
45 u32 th_magic; /* YYTH_MAGIC */
46 u32 th_hsize;
47 u32 th_ssize;
48 u16 th_flags;
49 char th_version[];
50};
51
52/* The YYTD_ID are one less than flex table mappings. The flex id
53 * has 1 subtracted at table load time, this allows us to directly use the
54 * ID's as indexes.
55 */
56#define YYTD_ID_ACCEPT 0
57#define YYTD_ID_BASE 1
58#define YYTD_ID_CHK 2
59#define YYTD_ID_DEF 3
60#define YYTD_ID_EC 4
61#define YYTD_ID_META 5
62#define YYTD_ID_ACCEPT2 6
63#define YYTD_ID_NXT 7
64#define YYTD_ID_TSIZE 8
65
66#define YYTD_DATA8 1
67#define YYTD_DATA16 2
68#define YYTD_DATA32 4
69#define YYTD_DATA64 8
70
71/* ACCEPT & ACCEPT2 tables gets 6 dedicated flags, YYTD_DATAX define the
72 * first flags
73 */
74#define ACCEPT1_FLAGS(X) ((X) & 0x3f)
75#define ACCEPT2_FLAGS(X) ACCEPT1_FLAGS((X) >> YYTD_ID_ACCEPT2)
76#define TO_ACCEPT1_FLAG(X) ACCEPT1_FLAGS(X)
77#define TO_ACCEPT2_FLAG(X) (ACCEPT1_FLAGS(X) << YYTD_ID_ACCEPT2)
78#define DFA_FLAG_VERIFY_STATES 0x1000
79
80struct table_header {
81 u16 td_id;
82 u16 td_flags;
83 u32 td_hilen;
84 u32 td_lolen;
85 char td_data[];
86};
87
88#define DEFAULT_TABLE(DFA) ((u16 *)((DFA)->tables[YYTD_ID_DEF]->td_data))
89#define BASE_TABLE(DFA) ((u32 *)((DFA)->tables[YYTD_ID_BASE]->td_data))
90#define NEXT_TABLE(DFA) ((u16 *)((DFA)->tables[YYTD_ID_NXT]->td_data))
91#define CHECK_TABLE(DFA) ((u16 *)((DFA)->tables[YYTD_ID_CHK]->td_data))
92#define EQUIV_TABLE(DFA) ((u8 *)((DFA)->tables[YYTD_ID_EC]->td_data))
93#define ACCEPT_TABLE(DFA) ((u32 *)((DFA)->tables[YYTD_ID_ACCEPT]->td_data))
94#define ACCEPT_TABLE2(DFA) ((u32 *)((DFA)->tables[YYTD_ID_ACCEPT2]->td_data))
95
96struct aa_dfa {
97 struct kref count;
98 u16 flags;
99 struct table_header *tables[YYTD_ID_TSIZE];
100};
101
102#define byte_to_byte(X) (X)
103
104#define UNPACK_ARRAY(TABLE, BLOB, LEN, TYPE, NTOHX) \
105 do { \
106 typeof(LEN) __i; \
107 TYPE *__t = (TYPE *) TABLE; \
108 TYPE *__b = (TYPE *) BLOB; \
109 for (__i = 0; __i < LEN; __i++) { \
110 __t[__i] = NTOHX(__b[__i]); \
111 } \
112 } while (0)
113
114static inline size_t table_size(size_t len, size_t el_size)
115{
116 return ALIGN(sizeof(struct table_header) + len * el_size, 8);
117}
118
119struct aa_dfa *aa_dfa_unpack(void *blob, size_t size, int flags);
120unsigned int aa_dfa_match_len(struct aa_dfa *dfa, unsigned int start,
121 const char *str, int len);
122unsigned int aa_dfa_match(struct aa_dfa *dfa, unsigned int start,
123 const char *str);
124unsigned int aa_dfa_next(struct aa_dfa *dfa, unsigned int state,
125 const char c);
126
127void aa_dfa_free_kref(struct kref *kref);
128
129/**
130 * aa_put_dfa - put a dfa refcount
131 * @dfa: dfa to put refcount (MAYBE NULL)
132 *
133 * Requires: if @dfa != NULL that a valid refcount be held
134 */
135static inline void aa_put_dfa(struct aa_dfa *dfa)
136{
137 if (dfa)
138 kref_put(&dfa->count, aa_dfa_free_kref);
139}
140
141#endif /* __AA_MATCH_H */
1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * AppArmor security module
4 *
5 * This file contains AppArmor policy dfa matching engine definitions.
6 *
7 * Copyright (C) 1998-2008 Novell/SUSE
8 * Copyright 2009-2012 Canonical Ltd.
9 */
10
11#ifndef __AA_MATCH_H
12#define __AA_MATCH_H
13
14#include <linux/kref.h>
15
16#define DFA_NOMATCH 0
17#define DFA_START 1
18
19
20/**
21 * The format used for transition tables is based on the GNU flex table
22 * file format (--tables-file option; see Table File Format in the flex
23 * info pages and the flex sources for documentation). The magic number
24 * used in the header is 0x1B5E783D instead of 0xF13C57B1 though, because
25 * new tables have been defined and others YY_ID_CHK (check) and YY_ID_DEF
26 * (default) tables are used slightly differently (see the apparmor-parser
27 * package).
28 *
29 *
30 * The data in the packed dfa is stored in network byte order, and the tables
31 * are arranged for flexibility. We convert the table data to host native
32 * byte order.
33 *
34 * The dfa begins with a table set header, and is followed by the actual
35 * tables.
36 */
37
38#define YYTH_MAGIC 0x1B5E783D
39#define YYTH_FLAG_DIFF_ENCODE 1
40#define YYTH_FLAG_OOB_TRANS 2
41#define YYTH_FLAGS (YYTH_FLAG_DIFF_ENCODE | YYTH_FLAG_OOB_TRANS)
42
43#define MAX_OOB_SUPPORTED 1
44
45struct table_set_header {
46 u32 th_magic; /* YYTH_MAGIC */
47 u32 th_hsize;
48 u32 th_ssize;
49 u16 th_flags;
50 char th_version[];
51};
52
53/* The YYTD_ID are one less than flex table mappings. The flex id
54 * has 1 subtracted at table load time, this allows us to directly use the
55 * ID's as indexes.
56 */
57#define YYTD_ID_ACCEPT 0
58#define YYTD_ID_BASE 1
59#define YYTD_ID_CHK 2
60#define YYTD_ID_DEF 3
61#define YYTD_ID_EC 4
62#define YYTD_ID_META 5
63#define YYTD_ID_ACCEPT2 6
64#define YYTD_ID_NXT 7
65#define YYTD_ID_TSIZE 8
66#define YYTD_ID_MAX 8
67
68#define YYTD_DATA8 1
69#define YYTD_DATA16 2
70#define YYTD_DATA32 4
71#define YYTD_DATA64 8
72
73/* ACCEPT & ACCEPT2 tables gets 6 dedicated flags, YYTD_DATAX define the
74 * first flags
75 */
76#define ACCEPT1_FLAGS(X) ((X) & 0x3f)
77#define ACCEPT2_FLAGS(X) ACCEPT1_FLAGS((X) >> YYTD_ID_ACCEPT2)
78#define TO_ACCEPT1_FLAG(X) ACCEPT1_FLAGS(X)
79#define TO_ACCEPT2_FLAG(X) (ACCEPT1_FLAGS(X) << YYTD_ID_ACCEPT2)
80#define DFA_FLAG_VERIFY_STATES 0x1000
81
82struct table_header {
83 u16 td_id;
84 u16 td_flags;
85 u32 td_hilen;
86 u32 td_lolen;
87 char td_data[];
88};
89
90#define DEFAULT_TABLE(DFA) ((u16 *)((DFA)->tables[YYTD_ID_DEF]->td_data))
91#define BASE_TABLE(DFA) ((u32 *)((DFA)->tables[YYTD_ID_BASE]->td_data))
92#define NEXT_TABLE(DFA) ((u16 *)((DFA)->tables[YYTD_ID_NXT]->td_data))
93#define CHECK_TABLE(DFA) ((u16 *)((DFA)->tables[YYTD_ID_CHK]->td_data))
94#define EQUIV_TABLE(DFA) ((u8 *)((DFA)->tables[YYTD_ID_EC]->td_data))
95#define ACCEPT_TABLE(DFA) ((u32 *)((DFA)->tables[YYTD_ID_ACCEPT]->td_data))
96#define ACCEPT_TABLE2(DFA) ((u32 *)((DFA)->tables[YYTD_ID_ACCEPT2]->td_data))
97
98struct aa_dfa {
99 struct kref count;
100 u16 flags;
101 u32 max_oob;
102 struct table_header *tables[YYTD_ID_TSIZE];
103};
104
105extern struct aa_dfa *nulldfa;
106extern struct aa_dfa *stacksplitdfa;
107
108#define byte_to_byte(X) (X)
109
110#define UNPACK_ARRAY(TABLE, BLOB, LEN, TTYPE, BTYPE, NTOHX) \
111 do { \
112 typeof(LEN) __i; \
113 TTYPE *__t = (TTYPE *) TABLE; \
114 BTYPE *__b = (BTYPE *) BLOB; \
115 for (__i = 0; __i < LEN; __i++) { \
116 __t[__i] = NTOHX(__b[__i]); \
117 } \
118 } while (0)
119
120static inline size_t table_size(size_t len, size_t el_size)
121{
122 return ALIGN(sizeof(struct table_header) + len * el_size, 8);
123}
124
125int aa_setup_dfa_engine(void);
126void aa_teardown_dfa_engine(void);
127
128#define aa_state_t unsigned int
129
130struct aa_dfa *aa_dfa_unpack(void *blob, size_t size, int flags);
131aa_state_t aa_dfa_match_len(struct aa_dfa *dfa, aa_state_t start,
132 const char *str, int len);
133aa_state_t aa_dfa_match(struct aa_dfa *dfa, aa_state_t start,
134 const char *str);
135aa_state_t aa_dfa_next(struct aa_dfa *dfa, aa_state_t state, const char c);
136aa_state_t aa_dfa_outofband_transition(struct aa_dfa *dfa, aa_state_t state);
137aa_state_t aa_dfa_match_until(struct aa_dfa *dfa, aa_state_t start,
138 const char *str, const char **retpos);
139aa_state_t aa_dfa_matchn_until(struct aa_dfa *dfa, aa_state_t start,
140 const char *str, int n, const char **retpos);
141
142void aa_dfa_free_kref(struct kref *kref);
143
144#define WB_HISTORY_SIZE 24
145struct match_workbuf {
146 unsigned int count;
147 unsigned int pos;
148 unsigned int len;
149 unsigned int size; /* power of 2, same as history size */
150 unsigned int history[WB_HISTORY_SIZE];
151};
152#define DEFINE_MATCH_WB(N) \
153struct match_workbuf N = { \
154 .count = 0, \
155 .pos = 0, \
156 .len = 0, \
157}
158
159aa_state_t aa_dfa_leftmatch(struct aa_dfa *dfa, aa_state_t start,
160 const char *str, unsigned int *count);
161
162/**
163 * aa_get_dfa - increment refcount on dfa @p
164 * @dfa: dfa (MAYBE NULL)
165 *
166 * Returns: pointer to @dfa if @dfa is NULL will return NULL
167 * Requires: @dfa must be held with valid refcount when called
168 */
169static inline struct aa_dfa *aa_get_dfa(struct aa_dfa *dfa)
170{
171 if (dfa)
172 kref_get(&(dfa->count));
173
174 return dfa;
175}
176
177/**
178 * aa_put_dfa - put a dfa refcount
179 * @dfa: dfa to put refcount (MAYBE NULL)
180 *
181 * Requires: if @dfa != NULL that a valid refcount be held
182 */
183static inline void aa_put_dfa(struct aa_dfa *dfa)
184{
185 if (dfa)
186 kref_put(&dfa->count, aa_dfa_free_kref);
187}
188
189#define MATCH_FLAG_DIFF_ENCODE 0x80000000
190#define MARK_DIFF_ENCODE 0x40000000
191#define MATCH_FLAG_OOB_TRANSITION 0x20000000
192#define MATCH_FLAGS_MASK 0xff000000
193#define MATCH_FLAGS_VALID (MATCH_FLAG_DIFF_ENCODE | MATCH_FLAG_OOB_TRANSITION)
194#define MATCH_FLAGS_INVALID (MATCH_FLAGS_MASK & ~MATCH_FLAGS_VALID)
195
196#endif /* __AA_MATCH_H */