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
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
|
//
// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2018
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#pragma once
#include "td/utils/buffer.h"
#include "td/utils/common.h"
#include "td/utils/format.h"
#include "td/utils/logging.h"
#include "td/utils/misc.h"
#include "td/utils/Slice.h"
#include "td/utils/Status.h"
#include "td/utils/utf8.h"
#include <array>
#include <cstring>
#include <limits>
#include <string>
namespace td {
class TlParser {
const unsigned char *data = nullptr;
size_t data_len = 0;
size_t left_len = 0;
size_t error_pos = std::numeric_limits<size_t>::max();
std::string error;
unique_ptr<int32[]> data_buf;
static constexpr size_t SMALL_DATA_ARRAY_SIZE = 6;
std::array<int32, SMALL_DATA_ARRAY_SIZE> small_data_array;
alignas(4) static const unsigned char empty_data[sizeof(UInt256)];
public:
explicit TlParser(Slice slice) {
if (slice.size() % sizeof(int32) != 0) {
set_error("Wrong length");
return;
}
data_len = left_len = slice.size();
if (is_aligned_pointer<4>(slice.begin())) {
data = slice.ubegin();
} else {
int32 *buf;
if (data_len <= small_data_array.size() * sizeof(int32)) {
buf = &small_data_array[0];
} else {
LOG(ERROR) << "Unexpected big unaligned data pointer of length " << slice.size() << " at " << slice.begin();
data_buf = make_unique<int32[]>(data_len / sizeof(int32));
buf = data_buf.get();
}
std::memcpy(static_cast<void *>(buf), static_cast<const void *>(slice.begin()), slice.size());
data = reinterpret_cast<unsigned char *>(buf);
}
}
TlParser(const TlParser &other) = delete;
TlParser &operator=(const TlParser &other) = delete;
void set_error(const string &error_message);
const char *get_error() const {
if (error.empty()) {
return nullptr;
}
return error.c_str();
}
size_t get_error_pos() const {
return error_pos;
}
Status get_status() const {
if (error.empty()) {
return Status::OK();
}
return Status::Error(PSLICE() << error << " at " << error_pos);
}
void check_len(const size_t len) {
if (unlikely(left_len < len)) {
set_error("Not enough data to read");
} else {
left_len -= len;
}
}
int32 fetch_int_unsafe() {
int32 result = *reinterpret_cast<const int32 *>(data);
data += sizeof(int32);
return result;
}
int32 fetch_int() {
check_len(sizeof(int32));
return fetch_int_unsafe();
}
int64 fetch_long_unsafe() {
int64 result;
std::memcpy(reinterpret_cast<unsigned char *>(&result), data, sizeof(int64));
data += sizeof(int64);
return result;
}
int64 fetch_long() {
check_len(sizeof(int64));
return fetch_long_unsafe();
}
double fetch_double_unsafe() {
double result;
std::memcpy(reinterpret_cast<unsigned char *>(&result), data, sizeof(double));
data += sizeof(double);
return result;
}
double fetch_double() {
check_len(sizeof(double));
return fetch_double_unsafe();
}
template <class T>
T fetch_binary_unsafe() {
T result;
std::memcpy(reinterpret_cast<unsigned char *>(&result), data, sizeof(T));
data += sizeof(T);
return result;
}
template <class T>
T fetch_binary() {
static_assert(sizeof(T) <= sizeof(empty_data), "too big fetch_binary");
static_assert(sizeof(T) % sizeof(int32) == 0, "wrong call to fetch_binary");
check_len(sizeof(T));
return fetch_binary_unsafe<T>();
}
template <class T>
T fetch_string() {
check_len(sizeof(int32));
size_t result_len = *data;
const char *result_begin;
size_t result_aligned_len;
if (result_len < 254) {
result_begin = reinterpret_cast<const char *>(data + 1);
result_aligned_len = (result_len >> 2) << 2;
} else if (result_len == 254) {
result_len = data[1] + (data[2] << 8) + (data[3] << 16);
result_begin = reinterpret_cast<const char *>(data + 4);
result_aligned_len = ((result_len + 3) >> 2) << 2;
} else {
set_error("Can't fetch string, 255 found");
return T();
}
check_len(result_aligned_len);
data += result_aligned_len + sizeof(int32);
return T(result_begin, result_len);
}
template <class T>
T fetch_string_raw(const size_t size) {
CHECK(size % sizeof(int32) == 0);
check_len(size);
const char *result = reinterpret_cast<const char *>(data);
data += size;
return T(result, size);
}
void fetch_end() {
if (left_len) {
set_error("Too much data to fetch");
}
}
size_t get_left_len() const {
return left_len;
}
};
class TlBufferParser : public TlParser {
public:
explicit TlBufferParser(const BufferSlice *buffer_slice) : TlParser(buffer_slice->as_slice()), parent_(buffer_slice) {
}
template <class T>
T fetch_string() {
auto result = TlParser::fetch_string<T>();
for (auto &c : result) {
if (c == '\0') {
c = ' ';
}
}
if (check_utf8(result)) {
return result;
}
CHECK(!result.empty());
LOG(WARNING) << "Wrong UTF-8 string [[" << result << "]] in " << format::as_hex_dump<4>(parent_->as_slice());
// trying to remove last character
size_t new_size = result.size() - 1;
while (new_size != 0 && !is_utf8_character_first_code_unit(static_cast<unsigned char>(result[new_size]))) {
new_size--;
}
result.resize(new_size);
if (check_utf8(result)) {
return result;
}
return T();
}
template <class T>
T fetch_string_raw(const size_t size) {
return TlParser::fetch_string_raw<T>(size);
}
private:
const BufferSlice *parent_;
BufferSlice as_buffer_slice(Slice slice) {
if (is_aligned_pointer<4>(slice.data())) {
return parent_->from_slice(slice);
}
return BufferSlice(slice);
}
};
template <>
inline BufferSlice TlBufferParser::fetch_string<BufferSlice>() {
return as_buffer_slice(TlParser::fetch_string<Slice>());
}
template <>
inline BufferSlice TlBufferParser::fetch_string_raw<BufferSlice>(const size_t size) {
return as_buffer_slice(TlParser::fetch_string_raw<Slice>(size));
}
} // namespace td
|
