1 // Copyright 2014 The Chromium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "base/big_endian.h"
6
7 #include <stdint.h>
8
9 #include <limits>
10
11 #include "base/strings/string_piece.h"
12 #include "testing/gtest/include/gtest/gtest.h"
13
14 namespace base {
15
TEST(ReadBigEndianTest,ReadSignedPositive)16 TEST(ReadBigEndianTest, ReadSignedPositive) {
17 uint8_t data[] = {0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x1A, 0x2A};
18 int8_t s8 = 0;
19 int16_t s16 = 0;
20 int32_t s32 = 0;
21 int64_t s64 = 0;
22 ReadBigEndian(data, &s8);
23 ReadBigEndian(data, &s16);
24 ReadBigEndian(data, &s32);
25 ReadBigEndian(data, &s64);
26 EXPECT_EQ(0x0A, s8);
27 EXPECT_EQ(0x0A0B, s16);
28 EXPECT_EQ(int32_t{0x0A0B0C0D}, s32);
29 EXPECT_EQ(int64_t{0x0A0B0C0D0E0F1A2All}, s64);
30 }
31
TEST(ReadBigEndianTest,ReadSignedNegative)32 TEST(ReadBigEndianTest, ReadSignedNegative) {
33 uint8_t data[] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
34 int8_t s8 = 0;
35 int16_t s16 = 0;
36 int32_t s32 = 0;
37 int64_t s64 = 0;
38 ReadBigEndian(data, &s8);
39 ReadBigEndian(data, &s16);
40 ReadBigEndian(data, &s32);
41 ReadBigEndian(data, &s64);
42 EXPECT_EQ(-1, s8);
43 EXPECT_EQ(-1, s16);
44 EXPECT_EQ(-1, s32);
45 EXPECT_EQ(-1, s64);
46 }
47
TEST(ReadBigEndianTest,ReadUnsignedSigned)48 TEST(ReadBigEndianTest, ReadUnsignedSigned) {
49 uint8_t data[] = {0xA0, 0xB0, 0xC0, 0xD0, 0xE0, 0xF0, 0xA1, 0xA2};
50 uint8_t u8 = 0;
51 uint16_t u16 = 0;
52 uint32_t u32 = 0;
53 uint64_t u64 = 0;
54 ReadBigEndian(data, &u8);
55 ReadBigEndian(data, &u16);
56 ReadBigEndian(data, &u32);
57 ReadBigEndian(data, &u64);
58 EXPECT_EQ(0xA0, u8);
59 EXPECT_EQ(0xA0B0, u16);
60 EXPECT_EQ(0xA0B0C0D0, u32);
61 EXPECT_EQ(0xA0B0C0D0E0F0A1A2ull, u64);
62 }
63
TEST(ReadBigEndianTest,TryAll16BitValues)64 TEST(ReadBigEndianTest, TryAll16BitValues) {
65 using signed_type = int16_t;
66 uint8_t data[sizeof(signed_type)];
67 for (int i = std::numeric_limits<signed_type>::min();
68 i <= std::numeric_limits<signed_type>::max(); i++) {
69 signed_type expected = i;
70 signed_type actual = 0;
71 WriteBigEndian(reinterpret_cast<char*>(data), expected);
72 ReadBigEndian(data, &actual);
73 EXPECT_EQ(expected, actual);
74 }
75 }
76
TEST(BigEndianReaderTest,ReadsValues)77 TEST(BigEndianReaderTest, ReadsValues) {
78 uint8_t data[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0xA,
79 0xB, 0xC, 0xD, 0xE, 0xF, 0x1A, 0x2B, 0x3C, 0x4D, 0x5E};
80 char buf[2];
81 uint8_t u8;
82 uint16_t u16;
83 uint32_t u32;
84 uint64_t u64;
85 base::StringPiece piece;
86 BigEndianReader reader(data, sizeof(data));
87
88 EXPECT_TRUE(reader.Skip(2));
89 EXPECT_EQ(data + 2, reader.ptr());
90 EXPECT_EQ(reader.remaining(), sizeof(data) - 2);
91 EXPECT_TRUE(reader.ReadBytes(buf, sizeof(buf)));
92 EXPECT_EQ(0x2, buf[0]);
93 EXPECT_EQ(0x3, buf[1]);
94 EXPECT_TRUE(reader.ReadU8(&u8));
95 EXPECT_EQ(0x4, u8);
96 EXPECT_TRUE(reader.ReadU16(&u16));
97 EXPECT_EQ(0x0506, u16);
98 EXPECT_TRUE(reader.ReadU32(&u32));
99 EXPECT_EQ(0x0708090Au, u32);
100 EXPECT_TRUE(reader.ReadU64(&u64));
101 EXPECT_EQ(0x0B0C0D0E0F1A2B3Cllu, u64);
102 base::StringPiece expected(reinterpret_cast<const char*>(reader.ptr()), 2);
103 EXPECT_TRUE(reader.ReadPiece(&piece, 2));
104 EXPECT_EQ(2u, piece.size());
105 EXPECT_EQ(expected.data(), piece.data());
106 }
107
TEST(BigEndianReaderTest,ReadsLengthPrefixedValues)108 TEST(BigEndianReaderTest, ReadsLengthPrefixedValues) {
109 {
110 uint8_t u8_prefixed_data[] = {8, 8, 9, 0xA, 0xB, 0xC, 0xD,
111 0xE, 0xF, 0x1A, 0x2B, 0x3C, 0x4D, 0x5E};
112 BigEndianReader reader(u8_prefixed_data, sizeof(u8_prefixed_data));
113
114 base::StringPiece piece;
115 ASSERT_TRUE(reader.ReadU8LengthPrefixed(&piece));
116 // |reader| should skip both a u8 and the length-8 length-prefixed field.
117 EXPECT_EQ(reader.ptr(), u8_prefixed_data + 9);
118 EXPECT_EQ(piece.size(), 8u);
119 EXPECT_EQ(reinterpret_cast<const uint8_t*>(piece.data()),
120 u8_prefixed_data + 1);
121 }
122
123 {
124 uint8_t u16_prefixed_data[] = {0, 8, 0xD, 0xE, 0xF,
125 0x1A, 0x2B, 0x3C, 0x4D, 0x5E};
126 BigEndianReader reader(u16_prefixed_data, sizeof(u16_prefixed_data));
127 base::StringPiece piece;
128 ASSERT_TRUE(reader.ReadU16LengthPrefixed(&piece));
129 // |reader| should skip both a u16 and the length-8 length-prefixed field.
130 EXPECT_EQ(reader.ptr(), u16_prefixed_data + 10);
131 EXPECT_EQ(piece.size(), 8u);
132 EXPECT_EQ(reinterpret_cast<const uint8_t*>(piece.data()),
133 u16_prefixed_data + 2);
134
135 // With no data left, we shouldn't be able to
136 // read another u8 length prefix (or a u16 length prefix,
137 // for that matter).
138 EXPECT_FALSE(reader.ReadU8LengthPrefixed(&piece));
139 EXPECT_FALSE(reader.ReadU16LengthPrefixed(&piece));
140 }
141
142 {
143 // Make sure there's no issue reading a zero-value length prefix.
144 uint8_t u16_prefixed_data[3] = {};
145 BigEndianReader reader(u16_prefixed_data, sizeof(u16_prefixed_data));
146 base::StringPiece piece;
147 ASSERT_TRUE(reader.ReadU16LengthPrefixed(&piece));
148 EXPECT_EQ(reader.ptr(), u16_prefixed_data + 2);
149 EXPECT_EQ(reinterpret_cast<const uint8_t*>(piece.data()),
150 u16_prefixed_data + 2);
151 EXPECT_EQ(piece.size(), 0u);
152 }
153 }
154
TEST(BigEndianReaderTest,LengthPrefixedReadsFailGracefully)155 TEST(BigEndianReaderTest, LengthPrefixedReadsFailGracefully) {
156 // We can't read 0xF (or, for that matter, 0xF8) bytes after the length
157 // prefix: there isn't enough data.
158 uint8_t data[] = {0xF, 8, 9, 0xA, 0xB, 0xC, 0xD,
159 0xE, 0xF, 0x1A, 0x2B, 0x3C, 0x4D, 0x5E};
160 BigEndianReader reader(data, sizeof(data));
161 base::StringPiece piece;
162 EXPECT_FALSE(reader.ReadU8LengthPrefixed(&piece));
163 EXPECT_EQ(data, reader.ptr());
164
165 EXPECT_FALSE(reader.ReadU16LengthPrefixed(&piece));
166 EXPECT_EQ(data, reader.ptr());
167 }
168
TEST(BigEndianReaderTest,RespectsLength)169 TEST(BigEndianReaderTest, RespectsLength) {
170 uint8_t data[8];
171 char buf[2];
172 uint8_t u8;
173 uint16_t u16;
174 uint32_t u32;
175 uint64_t u64;
176 base::StringPiece piece;
177 BigEndianReader reader(data, sizeof(data));
178 // 8 left
179 EXPECT_FALSE(reader.Skip(9));
180 EXPECT_TRUE(reader.Skip(1));
181 // 7 left
182 EXPECT_FALSE(reader.ReadU64(&u64));
183 EXPECT_TRUE(reader.Skip(4));
184 // 3 left
185 EXPECT_FALSE(reader.ReadU32(&u32));
186 EXPECT_FALSE(reader.ReadPiece(&piece, 4));
187 EXPECT_TRUE(reader.Skip(2));
188 // 1 left
189 EXPECT_FALSE(reader.ReadU16(&u16));
190 EXPECT_FALSE(reader.ReadBytes(buf, 2));
191 EXPECT_TRUE(reader.Skip(1));
192 // 0 left
193 EXPECT_FALSE(reader.ReadU8(&u8));
194 EXPECT_EQ(0u, reader.remaining());
195 }
196
TEST(BigEndianReaderTest,SafePointerMath)197 TEST(BigEndianReaderTest, SafePointerMath) {
198 uint8_t data[] = "foo";
199 BigEndianReader reader(data, sizeof(data));
200 // The test should fail without ever dereferencing the |dummy_buf| pointer.
201 char* dummy_buf = reinterpret_cast<char*>(0xdeadbeef);
202 // Craft an extreme length value that would cause |reader.data() + len| to
203 // overflow.
204 size_t extreme_length = std::numeric_limits<size_t>::max() - 1;
205 base::StringPiece piece;
206 EXPECT_FALSE(reader.Skip(extreme_length));
207 EXPECT_FALSE(reader.ReadBytes(dummy_buf, extreme_length));
208 EXPECT_FALSE(reader.ReadPiece(&piece, extreme_length));
209 }
210
TEST(BigEndianWriterTest,WritesValues)211 TEST(BigEndianWriterTest, WritesValues) {
212 char expected[] = { 0, 0, 2, 3, 4, 5, 6, 7, 8, 9, 0xA, 0xB, 0xC, 0xD, 0xE,
213 0xF, 0x1A, 0x2B, 0x3C };
214 char data[sizeof(expected)];
215 char buf[] = { 0x2, 0x3 };
216 memset(data, 0, sizeof(data));
217 BigEndianWriter writer(data, sizeof(data));
218
219 EXPECT_TRUE(writer.Skip(2));
220 EXPECT_TRUE(writer.WriteBytes(buf, sizeof(buf)));
221 EXPECT_TRUE(writer.WriteU8(0x4));
222 EXPECT_TRUE(writer.WriteU16(0x0506));
223 EXPECT_TRUE(writer.WriteU32(0x0708090A));
224 EXPECT_TRUE(writer.WriteU64(0x0B0C0D0E0F1A2B3Cllu));
225 EXPECT_EQ(0, memcmp(expected, data, sizeof(expected)));
226 }
227
TEST(BigEndianWriterTest,RespectsLength)228 TEST(BigEndianWriterTest, RespectsLength) {
229 char data[8];
230 char buf[2];
231 uint8_t u8 = 0;
232 uint16_t u16 = 0;
233 uint32_t u32 = 0;
234 uint64_t u64 = 0;
235 BigEndianWriter writer(data, sizeof(data));
236 // 8 left
237 EXPECT_FALSE(writer.Skip(9));
238 EXPECT_TRUE(writer.Skip(1));
239 // 7 left
240 EXPECT_FALSE(writer.WriteU64(u64));
241 EXPECT_TRUE(writer.Skip(4));
242 // 3 left
243 EXPECT_FALSE(writer.WriteU32(u32));
244 EXPECT_TRUE(writer.Skip(2));
245 // 1 left
246 EXPECT_FALSE(writer.WriteU16(u16));
247 EXPECT_FALSE(writer.WriteBytes(buf, 2));
248 EXPECT_TRUE(writer.Skip(1));
249 // 0 left
250 EXPECT_FALSE(writer.WriteU8(u8));
251 EXPECT_EQ(0u, writer.remaining());
252 }
253
TEST(BigEndianWriterTest,SafePointerMath)254 TEST(BigEndianWriterTest, SafePointerMath) {
255 char data[3];
256 BigEndianWriter writer(data, sizeof(data));
257 // The test should fail without ever dereferencing the |dummy_buf| pointer.
258 const char* dummy_buf = reinterpret_cast<const char*>(0xdeadbeef);
259 // Craft an extreme length value that would cause |reader.data() + len| to
260 // overflow.
261 size_t extreme_length = std::numeric_limits<size_t>::max() - 1;
262 EXPECT_FALSE(writer.Skip(extreme_length));
263 EXPECT_FALSE(writer.WriteBytes(dummy_buf, extreme_length));
264 }
265
266 } // namespace base
267