1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
|
/*
* Copyright (C) 2016, The CyanogenMod Project
* Copyright (C) 2017, The LineageOS Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <errno.h>
#include <fcntl.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <string>
#include <vector>
#include "edify/expr.h"
#include "otautil/error_code.h"
#define MAX(a, b) (((a) > (b)) ? (a) : (b))
#define ALPHABET_LEN 256
#define MODEM_PART_PATH "/dev/block/bootdevice/by-name/modem"
#define MODEM_VER_STR "Time_Stamp\": \""
#define MODEM_VER_STR_LEN 14
#define MODEM_VER_BUF_LEN 20
/* Boyer-Moore string search implementation from Wikipedia */
/* Return longest suffix length of suffix ending at str[p] */
static int max_suffix_len(const char *str, size_t str_len, size_t p) {
uint32_t i;
for (i = 0; (str[p - i] == str[str_len - 1 - i]) && (i < p); ) {
i++;
}
return i;
}
/* Generate table of distance between last character of pat and rightmost
* occurrence of character c in pat
*/
static void bm_make_delta1(int *delta1, const char *pat, size_t pat_len) {
uint32_t i;
for (i = 0; i < ALPHABET_LEN; i++) {
delta1[i] = pat_len;
}
for (i = 0; i < pat_len - 1; i++) {
uint8_t idx = (uint8_t) pat[i];
delta1[idx] = pat_len - 1 - i;
}
}
/* Generate table of next possible full match from mismatch at pat[p] */
static void bm_make_delta2(int *delta2, const char *pat, size_t pat_len) {
int p;
uint32_t last_prefix = pat_len - 1;
for (p = pat_len - 1; p >= 0; p--) {
/* Compare whether pat[p-pat_len] is suffix of pat */
if (strncmp(pat + p, pat, pat_len - p) == 0) {
last_prefix = p + 1;
}
delta2[p] = last_prefix + (pat_len - 1 - p);
}
for (p = 0; p < (int) pat_len - 1; p++) {
/* Get longest suffix of pattern ending on character pat[p] */
int suf_len = max_suffix_len(pat, pat_len, p);
if (pat[p - suf_len] != pat[pat_len - 1 - suf_len]) {
delta2[pat_len - 1 - suf_len] = pat_len - 1 - p + suf_len;
}
}
}
static char * bm_search(const char *str, size_t str_len, const char *pat,
size_t pat_len) {
int delta1[ALPHABET_LEN];
int delta2[pat_len];
int i;
bm_make_delta1(delta1, pat, pat_len);
bm_make_delta2(delta2, pat, pat_len);
if (pat_len == 0) {
return (char *) str;
}
i = pat_len - 1;
while (i < (int) str_len) {
int j = pat_len - 1;
while (j >= 0 && (str[i] == pat[j])) {
i--;
j--;
}
if (j < 0) {
return (char *) (str + i + 1);
}
i += MAX(delta1[(uint8_t) str[i]], delta2[j]);
}
return NULL;
}
static int get_modem_version(char *ver_str, size_t len) {
int ret = 0;
int fd;
int modem_size;
char *modem_data = NULL;
char *offset = NULL;
fd = open(MODEM_PART_PATH, O_RDONLY);
if (fd < 0) {
ret = errno;
goto err_ret;
}
modem_size = lseek64(fd, 0, SEEK_END);
if (modem_size == -1) {
ret = errno;
goto err_fd_close;
}
modem_data = (char *) mmap(NULL, modem_size, PROT_READ, MAP_PRIVATE, fd, 0);
if (modem_data == (char *)-1) {
ret = errno;
goto err_fd_close;
}
/* Do Boyer-Moore search across MODEM data */
offset = bm_search(modem_data, modem_size, MODEM_VER_STR, MODEM_VER_STR_LEN);
if (offset != NULL) {
snprintf(ver_str, len, "%s", offset + MODEM_VER_STR_LEN);
} else {
ret = -ENOENT;
}
munmap(modem_data, modem_size);
err_fd_close:
close(fd);
err_ret:
return ret;
}
/* verify_modem("MODEM_VERSION", "MODEM_VERSION", ...) */
Value* VerifyModemFn(const char* name, State* state,
const std::vector<std::unique_ptr<Expr>>& argv) {
char current_modem_version[MODEM_VER_BUF_LEN];
int ret;
struct tm tm1, tm2;
ret = get_modem_version(current_modem_version, MODEM_VER_BUF_LEN);
if (ret) {
return ErrorAbort(state, kVendorFailure,
"%s() failed to read current MODEM build time-stamp: %d", name, ret);
}
std::vector<std::string> args;
if (!ReadArgs(state, argv, &args)) {
return ErrorAbort(state, kArgsParsingFailure, "%s() error parsing arguments", name);
}
memset(&tm1, 0, sizeof(tm));
strptime(current_modem_version, "%Y-%m-%d %H:%M:%S", &tm1);
ret = 0;
for (auto& modem_version : args) {
memset(&tm2, 0, sizeof(tm));
strptime(modem_version.c_str(), "%Y-%m-%d %H:%M:%S", &tm2);
if (mktime(&tm1) >= mktime(&tm2)) {
ret = 1;
break;
}
}
return StringValue(strdup(ret ? "1" : "0"));
}
void Register_librecovery_updater_xiaomi() {
RegisterFunction("xiaomi.verify_modem", VerifyModemFn);
}
|
