fec_private.h revision dadd5e33ac00df9a57114487f8441a59fd08bd89 
1/*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef __FEC_PRIVATE_H__
18#define __FEC_PRIVATE_H__
19
20#include <errno.h>
21#include <fcntl.h>
22#include <memory>
23#include <new>
24#include <pthread.h>
25#include <stdio.h>
26#include <string>
27#include <string.h>
28#include <sys/syscall.h>
29#include <unistd.h>
30#include <vector>
31
32#include <utils/Compat.h>
33#include <mincrypt/rsa.h>
34#include <openssl/sha.h>
35#include <fec/io.h>
36#include <fec/ecc.h>
37
38/* processing parameters */
39#define WORK_MIN_THREADS 1
40#define WORK_MAX_THREADS 64
41
42/* verity parameters */
43#define VERITY_CACHE_BLOCKS 4096
44#define VERITY_NO_CACHE UINT64_MAX
45
46/* verity definitions */
47#define VERITY_METADATA_SIZE (8 * FEC_BLOCKSIZE)
48#define VERITY_TABLE_ARGS 10 /* mandatory arguments */
49#define VERITY_MIN_TABLE_SIZE (VERITY_TABLE_ARGS * 2) /* for a sanity check */
50#define VERITY_MAX_TABLE_SIZE (VERITY_METADATA_SIZE - sizeof(verity_header))
51
52/* verity header and metadata */
53#define VERITY_MAGIC 0xB001B001
54#define VERITY_MAGIC_DISABLE 0x46464F56
55#define VERITY_VERSION 0
56#define VERITY_TABLE_FIELDS 10
57#define VERITY_TABLE_VERSION 1
58
59struct verity_header {
60    uint32_t magic;
61    uint32_t version;
62    uint8_t signature[RSANUMBYTES];
63    uint32_t length;
64};
65
66/* file handle */
67struct ecc_info {
68    bool valid;
69    int roots;
70    int rsn;
71    uint32_t size;
72    uint64_t blocks;
73    uint64_t rounds;
74    uint64_t start; /* offset in file */
75};
76
77struct verity_info {
78    bool disabled;
79    char *table;
80    uint32_t hash_data_blocks;
81    uint32_t hash_size;
82    uint64_t hash_data_offset;
83    uint64_t hash_start;
84    uint8_t *hash;
85    uint32_t salt_size;
86    uint8_t *salt;
87    uint64_t data_blocks;
88    uint64_t metadata_start; /* offset in file */
89    uint8_t zero_hash[SHA256_DIGEST_LENGTH];
90    verity_header header;
91};
92
93struct verity_block_info {
94    uint64_t index;
95    bool valid;
96};
97
98struct fec_handle {
99    ecc_info ecc;
100    int fd;
101    int flags; /* additional flags passed to fec_open */
102    int mode; /* mode for open(2) */
103    pthread_mutex_t mutex;
104    uint64_t errors;
105    uint64_t data_size;
106    uint64_t pos;
107    uint64_t size;
108    verity_info verity;
109};
110
111/* I/O helpers */
112extern bool raw_pread(fec_handle *f, void *buf, size_t count,
113        uint64_t offset);
114extern bool raw_pwrite(fec_handle *f, const void *buf, size_t count,
115        uint64_t offset);
116
117/* processing functions */
118typedef ssize_t (*read_func)(fec_handle *f, uint8_t *dest, size_t count,
119        uint64_t offset, size_t *errors);
120
121extern ssize_t process(fec_handle *f, uint8_t *buf, size_t count,
122        uint64_t offset, read_func func);
123
124/* verity functions */
125extern uint64_t verity_get_size(uint64_t file_size, uint32_t *verity_levels,
126        uint32_t *level_hashes);
127
128extern int verity_parse_header(fec_handle *f, uint64_t offset);
129
130extern bool verity_check_block(fec_handle *f, const uint8_t *expected,
131        const uint8_t *block);
132
133/* helper macros */
134#ifndef unlikely
135    #define unlikely(x) __builtin_expect(!!(x), 0)
136    #define likely(x)   __builtin_expect(!!(x), 1)
137#endif
138
139#ifndef stringify
140    #define __stringify(x) #x
141    #define stringify(x) __stringify(x)
142#endif
143
144/*  warnings, errors, debug output */
145#ifdef FEC_NO_KLOG
146    #define __log(func, type, format, args...) \
147        fprintf(stderr, "fec: <%d> " type ": %s: " format "\n", \
148            (int)syscall(SYS_gettid), __FUNCTION__,  ##args)
149#else
150    #include <cutils/klog.h>
151
152    #define __log(func, type, format, args...) \
153        KLOG_##func("fec", "<%d> " type ": %s: " format "\n", \
154            (int)syscall(SYS_gettid), __FUNCTION__, ##args)
155#endif
156
157#ifdef NDEBUG
158    #define debug(format, args...)
159#else
160    #define debug(format, args...) __log(DEBUG, "debug", format, ##args)
161#endif
162
163#define warn(format, args...) __log(WARNING, "warning", format, ##args)
164#define error(format, args...) __log(ERROR, "error", format, ##args)
165
166#define check(p) \
167    if (unlikely(!(p))) { \
168        error("`%s' failed", #p); \
169        errno = EFAULT; \
170        return -1; \
171    }
172
173#endif /* __FEC_PRIVATE_H__ */
174