1e06f75a6SJohn Johansen /* 2e06f75a6SJohn Johansen * AppArmor security module 3e06f75a6SJohn Johansen * 4e06f75a6SJohn Johansen * This file contains AppArmor policy dfa matching engine definitions. 5e06f75a6SJohn Johansen * 6e06f75a6SJohn Johansen * Copyright (C) 1998-2008 Novell/SUSE 7e06f75a6SJohn Johansen * Copyright 2009-2010 Canonical Ltd. 8e06f75a6SJohn Johansen * 9e06f75a6SJohn Johansen * This program is free software; you can redistribute it and/or 10e06f75a6SJohn Johansen * modify it under the terms of the GNU General Public License as 11e06f75a6SJohn Johansen * published by the Free Software Foundation, version 2 of the 12e06f75a6SJohn Johansen * License. 13e06f75a6SJohn Johansen */ 14e06f75a6SJohn Johansen 15e06f75a6SJohn Johansen #ifndef __AA_MATCH_H 16e06f75a6SJohn Johansen #define __AA_MATCH_H 17e06f75a6SJohn Johansen 1857cc7215SAlexey Dobriyan #include <linux/kref.h> 19e06f75a6SJohn Johansen #include <linux/workqueue.h> 20e06f75a6SJohn Johansen 21e06f75a6SJohn Johansen #define DFA_NOMATCH 0 22e06f75a6SJohn Johansen #define DFA_START 1 23e06f75a6SJohn Johansen 24e06f75a6SJohn Johansen #define DFA_VALID_PERM_MASK 0xffffffff 25e06f75a6SJohn Johansen #define DFA_VALID_PERM2_MASK 0xffffffff 26e06f75a6SJohn Johansen 27e06f75a6SJohn Johansen /** 28e06f75a6SJohn Johansen * The format used for transition tables is based on the GNU flex table 29e06f75a6SJohn Johansen * file format (--tables-file option; see Table File Format in the flex 30e06f75a6SJohn Johansen * info pages and the flex sources for documentation). The magic number 31e06f75a6SJohn Johansen * used in the header is 0x1B5E783D insted of 0xF13C57B1 though, because 32e06f75a6SJohn Johansen * the YY_ID_CHK (check) and YY_ID_DEF (default) tables are used 33e06f75a6SJohn Johansen * slightly differently (see the apparmor-parser package). 34e06f75a6SJohn Johansen */ 35e06f75a6SJohn Johansen 36e06f75a6SJohn Johansen #define YYTH_MAGIC 0x1B5E783D 37e06f75a6SJohn Johansen #define YYTH_DEF_RECURSE 0x1 /* DEF Table is recursive */ 38e06f75a6SJohn Johansen 39e06f75a6SJohn Johansen struct table_set_header { 40e06f75a6SJohn Johansen u32 th_magic; /* YYTH_MAGIC */ 41e06f75a6SJohn Johansen u32 th_hsize; 42e06f75a6SJohn Johansen u32 th_ssize; 43e06f75a6SJohn Johansen u16 th_flags; 44e06f75a6SJohn Johansen char th_version[]; 45e06f75a6SJohn Johansen }; 46e06f75a6SJohn Johansen 47e06f75a6SJohn Johansen /* The YYTD_ID are one less than flex table mappings. The flex id 48e06f75a6SJohn Johansen * has 1 subtracted at table load time, this allows us to directly use the 49e06f75a6SJohn Johansen * ID's as indexes. 50e06f75a6SJohn Johansen */ 51e06f75a6SJohn Johansen #define YYTD_ID_ACCEPT 0 52e06f75a6SJohn Johansen #define YYTD_ID_BASE 1 53e06f75a6SJohn Johansen #define YYTD_ID_CHK 2 54e06f75a6SJohn Johansen #define YYTD_ID_DEF 3 55e06f75a6SJohn Johansen #define YYTD_ID_EC 4 56e06f75a6SJohn Johansen #define YYTD_ID_META 5 57e06f75a6SJohn Johansen #define YYTD_ID_ACCEPT2 6 58e06f75a6SJohn Johansen #define YYTD_ID_NXT 7 59e06f75a6SJohn Johansen #define YYTD_ID_TSIZE 8 60e06f75a6SJohn Johansen 61e06f75a6SJohn Johansen #define YYTD_DATA8 1 62e06f75a6SJohn Johansen #define YYTD_DATA16 2 63e06f75a6SJohn Johansen #define YYTD_DATA32 4 64e06f75a6SJohn Johansen #define YYTD_DATA64 8 65e06f75a6SJohn Johansen 66e06f75a6SJohn Johansen /* Each ACCEPT2 table gets 6 dedicated flags, YYTD_DATAX define the 67e06f75a6SJohn Johansen * first flags 68e06f75a6SJohn Johansen */ 69e06f75a6SJohn Johansen #define ACCEPT1_FLAGS(X) ((X) & 0x3f) 70e06f75a6SJohn Johansen #define ACCEPT2_FLAGS(X) ACCEPT1_FLAGS((X) >> YYTD_ID_ACCEPT2) 71e06f75a6SJohn Johansen #define TO_ACCEPT1_FLAG(X) ACCEPT1_FLAGS(X) 72e06f75a6SJohn Johansen #define TO_ACCEPT2_FLAG(X) (ACCEPT1_FLAGS(X) << YYTD_ID_ACCEPT2) 73e06f75a6SJohn Johansen #define DFA_FLAG_VERIFY_STATES 0x1000 74e06f75a6SJohn Johansen 75e06f75a6SJohn Johansen struct table_header { 76e06f75a6SJohn Johansen u16 td_id; 77e06f75a6SJohn Johansen u16 td_flags; 78e06f75a6SJohn Johansen u32 td_hilen; 79e06f75a6SJohn Johansen u32 td_lolen; 80e06f75a6SJohn Johansen char td_data[]; 81e06f75a6SJohn Johansen }; 82e06f75a6SJohn Johansen 83e06f75a6SJohn Johansen #define DEFAULT_TABLE(DFA) ((u16 *)((DFA)->tables[YYTD_ID_DEF]->td_data)) 84e06f75a6SJohn Johansen #define BASE_TABLE(DFA) ((u32 *)((DFA)->tables[YYTD_ID_BASE]->td_data)) 85e06f75a6SJohn Johansen #define NEXT_TABLE(DFA) ((u16 *)((DFA)->tables[YYTD_ID_NXT]->td_data)) 86e06f75a6SJohn Johansen #define CHECK_TABLE(DFA) ((u16 *)((DFA)->tables[YYTD_ID_CHK]->td_data)) 87e06f75a6SJohn Johansen #define EQUIV_TABLE(DFA) ((u8 *)((DFA)->tables[YYTD_ID_EC]->td_data)) 88e06f75a6SJohn Johansen #define ACCEPT_TABLE(DFA) ((u32 *)((DFA)->tables[YYTD_ID_ACCEPT]->td_data)) 89e06f75a6SJohn Johansen #define ACCEPT_TABLE2(DFA) ((u32 *)((DFA)->tables[YYTD_ID_ACCEPT2]->td_data)) 90e06f75a6SJohn Johansen 91e06f75a6SJohn Johansen struct aa_dfa { 92e06f75a6SJohn Johansen struct kref count; 93e06f75a6SJohn Johansen u16 flags; 94e06f75a6SJohn Johansen struct table_header *tables[YYTD_ID_TSIZE]; 95e06f75a6SJohn Johansen }; 96e06f75a6SJohn Johansen 97e06f75a6SJohn Johansen #define byte_to_byte(X) (X) 98e06f75a6SJohn Johansen 99e06f75a6SJohn Johansen #define UNPACK_ARRAY(TABLE, BLOB, LEN, TYPE, NTOHX) \ 100e06f75a6SJohn Johansen do { \ 101e06f75a6SJohn Johansen typeof(LEN) __i; \ 102e06f75a6SJohn Johansen TYPE *__t = (TYPE *) TABLE; \ 103e06f75a6SJohn Johansen TYPE *__b = (TYPE *) BLOB; \ 104e06f75a6SJohn Johansen for (__i = 0; __i < LEN; __i++) { \ 105e06f75a6SJohn Johansen __t[__i] = NTOHX(__b[__i]); \ 106e06f75a6SJohn Johansen } \ 107e06f75a6SJohn Johansen } while (0) 108e06f75a6SJohn Johansen 109e06f75a6SJohn Johansen static inline size_t table_size(size_t len, size_t el_size) 110e06f75a6SJohn Johansen { 111e06f75a6SJohn Johansen return ALIGN(sizeof(struct table_header) + len * el_size, 8); 112e06f75a6SJohn Johansen } 113e06f75a6SJohn Johansen 114e06f75a6SJohn Johansen struct aa_dfa *aa_dfa_unpack(void *blob, size_t size, int flags); 115e06f75a6SJohn Johansen unsigned int aa_dfa_match_len(struct aa_dfa *dfa, unsigned int start, 116e06f75a6SJohn Johansen const char *str, int len); 117e06f75a6SJohn Johansen unsigned int aa_dfa_match(struct aa_dfa *dfa, unsigned int start, 118e06f75a6SJohn Johansen const char *str); 119e06f75a6SJohn Johansen void aa_dfa_free_kref(struct kref *kref); 120e06f75a6SJohn Johansen 121e06f75a6SJohn Johansen /** 122e06f75a6SJohn Johansen * aa_put_dfa - put a dfa refcount 123e06f75a6SJohn Johansen * @dfa: dfa to put refcount (MAYBE NULL) 124e06f75a6SJohn Johansen * 125e06f75a6SJohn Johansen * Requires: if @dfa != NULL that a valid refcount be held 126e06f75a6SJohn Johansen */ 127e06f75a6SJohn Johansen static inline void aa_put_dfa(struct aa_dfa *dfa) 128e06f75a6SJohn Johansen { 129e06f75a6SJohn Johansen if (dfa) 130e06f75a6SJohn Johansen kref_put(&dfa->count, aa_dfa_free_kref); 131e06f75a6SJohn Johansen } 132e06f75a6SJohn Johansen 133e06f75a6SJohn Johansen #endif /* __AA_MATCH_H */ 134