1 // Copyright 2020 The Pigweed Authors
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not
4 // use this file except in compliance with the License. You may obtain a copy of
5 // the License at
6 //
7 // https://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
12 // License for the specific language governing permissions and limitations under
13 // the License.
14
15 #include "pw_hdlc/decoder.h"
16
17 #include <array>
18 #include <cstddef>
19
20 #include "gtest/gtest.h"
21 #include "pw_bytes/array.h"
22 #include "pw_hdlc/internal/protocol.h"
23
24 namespace pw::hdlc {
25 namespace {
26
27 using std::byte;
28
TEST(Frame,Fields)29 TEST(Frame, Fields) {
30 static constexpr auto kFrameData =
31 bytes::String("\x05\xab\x42\x24\xf9\x54\xfb\x3d");
32 auto result = Frame::Parse(kFrameData);
33 ASSERT_TRUE(result.ok());
34 Frame& frame = result.value();
35
36 EXPECT_EQ(frame.address(), 2u);
37 EXPECT_EQ(frame.control(), byte{0xab});
38
39 EXPECT_EQ(frame.data().size(), 2u);
40 EXPECT_EQ(frame.data()[0], byte{0x42});
41 EXPECT_EQ(frame.data()[1], byte{0x24});
42 }
43
TEST(Frame,MultibyteAddress)44 TEST(Frame, MultibyteAddress) {
45 static constexpr auto kFrameData =
46 bytes::String("\x2c\xd9\x33\x01\x02\xaf\xc8\x77\x48");
47 auto result = Frame::Parse(kFrameData);
48 ASSERT_TRUE(result.ok());
49 Frame& frame = result.value();
50
51 EXPECT_EQ(frame.address(), 0b11011000010110u);
52 EXPECT_EQ(frame.control(), byte{0x33});
53
54 EXPECT_EQ(frame.data().size(), 2u);
55 EXPECT_EQ(frame.data()[0], byte{0x01});
56 EXPECT_EQ(frame.data()[1], byte{0x02});
57 }
58
TEST(Frame,MultibyteAddressTooLong)59 TEST(Frame, MultibyteAddressTooLong) {
60 // 11-byte encoded address.
61 constexpr auto kLongAddress =
62 bytes::String("\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01");
63 static constexpr auto kFrameData = bytes::Concat(
64 kLongAddress, bytes::String("\x33\x01\x02\xaf\xc8\x77\x48"));
65 auto result = Frame::Parse(kFrameData);
66 EXPECT_EQ(result.status(), Status::DataLoss());
67 }
68
TEST(Decoder,Clear)69 TEST(Decoder, Clear) {
70 DecoderBuffer<8> decoder;
71
72 // Process a partial packet
73 decoder.Process(bytes::String("~1234abcd"),
74 [](const Result<Frame>&) { FAIL(); });
75
76 decoder.Clear();
77 Status status = Status::Unknown();
78
79 decoder.Process(
80 bytes::String("~1234\xa3\xe0\xe3\x9b~"),
81 [&status](const Result<Frame>& result) { status = result.status(); });
82
83 EXPECT_EQ(OkStatus(), status);
84 }
85
TEST(Decoder,ExactFit)86 TEST(Decoder, ExactFit) {
87 DecoderBuffer<8> decoder;
88
89 for (byte b : bytes::String("~1234\xa3\xe0\xe3\x9b")) {
90 EXPECT_EQ(Status::Unavailable(), decoder.Process(b).status());
91 }
92 auto result = decoder.Process(kFlag);
93 ASSERT_EQ(OkStatus(), result.status());
94 ASSERT_EQ(result.value().data().size(), 2u);
95 ASSERT_EQ(result.value().data()[0], byte{'3'});
96 ASSERT_EQ(result.value().data()[1], byte{'4'});
97 }
98
TEST(Decoder,MinimumSizedBuffer)99 TEST(Decoder, MinimumSizedBuffer) {
100 DecoderBuffer<6> decoder;
101
102 for (byte b : bytes::String("~12\xcd\x44\x53\x4f")) {
103 EXPECT_EQ(Status::Unavailable(), decoder.Process(b).status());
104 }
105
106 auto result = decoder.Process(kFlag);
107 ASSERT_EQ(OkStatus(), result.status());
108 EXPECT_EQ(result.value().data().size(), 0u);
109 }
110
TEST(Decoder,TooLargeForBuffer_ReportsResourceExhausted)111 TEST(Decoder, TooLargeForBuffer_ReportsResourceExhausted) {
112 DecoderBuffer<8> decoder;
113
114 for (byte b : bytes::String("~12345\x1c\x3a\xf5\xcb")) {
115 EXPECT_EQ(Status::Unavailable(), decoder.Process(b).status());
116 }
117 EXPECT_EQ(Status::ResourceExhausted(), decoder.Process(kFlag).status());
118
119 for (byte b : bytes::String("~12345678901234567890\xf2\x19\x63\x90")) {
120 EXPECT_EQ(Status::Unavailable(), decoder.Process(b).status());
121 }
122 EXPECT_EQ(Status::ResourceExhausted(), decoder.Process(kFlag).status());
123 }
124
TEST(Decoder,TooLargeForBuffer_StaysWithinBufferBoundaries)125 TEST(Decoder, TooLargeForBuffer_StaysWithinBufferBoundaries) {
126 std::array<byte, 16> buffer = bytes::Initialized<16>('?');
127
128 Decoder decoder(std::span(buffer.data(), 8));
129
130 for (byte b : bytes::String("~12345678901234567890\xf2\x19\x63\x90")) {
131 EXPECT_EQ(Status::Unavailable(), decoder.Process(b).status());
132 }
133
134 for (size_t i = 8; i < buffer.size(); ++i) {
135 ASSERT_EQ(byte{'?'}, buffer[i]);
136 }
137
138 EXPECT_EQ(Status::ResourceExhausted(), decoder.Process(kFlag).status());
139 }
140
TEST(Decoder,TooLargeForBuffer_DecodesNextFrame)141 TEST(Decoder, TooLargeForBuffer_DecodesNextFrame) {
142 DecoderBuffer<8> decoder;
143
144 for (byte b : bytes::String("~12345678901234567890\xf2\x19\x63\x90")) {
145 EXPECT_EQ(Status::Unavailable(), decoder.Process(b).status());
146 }
147 EXPECT_EQ(Status::ResourceExhausted(), decoder.Process(kFlag).status());
148
149 for (byte b : bytes::String("1234\xa3\xe0\xe3\x9b")) {
150 EXPECT_EQ(Status::Unavailable(), decoder.Process(b).status());
151 }
152 EXPECT_EQ(OkStatus(), decoder.Process(kFlag).status());
153 }
154
155 } // namespace
156 } // namespace pw::hdlc
157