Skip to content

Scan answers, authorities, additionals ignore questions #20

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
blasten merged 4 commits into from
May 3, 2019
Merged

Scan answers, authorities, additionals ignore questions #20

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
5785eb5
Separate record questions and answers
blasten May 3, 2019
bb88fd3
Fix counters
blasten May 3, 2019
0408342
Add tests
blasten May 3, 2019
9c2a1e4
Split into multiple named values
blasten May 3, 2019
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
17 changes: 14 additions & 3 deletions packages/multicast_dns/lib/src/packet.dart
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -222,11 +222,15 @@ List<ResourceRecord> decodeMDnsResponse(List<int> packet) {
final ByteData packetBytes = ByteData.view(data.buffer);

final int answerCount = packetBytes.getUint16(_kAncountOffset);
if (answerCount == 0) {
final int authorityCount = packetBytes.getUint16(_kNscountOffset);
final int additionalCount = packetBytes.getUint16(_kArcountOffset);
final int remainingCount = answerCount + authorityCount + additionalCount;

if (remainingCount == 0) {
return null;
}

final int answerRecordCount = packetBytes.getUint16(_kArcountOffset);
final int questionCount = packetBytes.getUint16(_kQdcountOffset);
int offset = _kHeaderSize;

void checkLength(int required) {
Expand Down Expand Up @@ -346,7 +350,14 @@ List<ResourceRecord> decodeMDnsResponse(List<int> packet) {
final List<ResourceRecord> result = <ResourceRecord>[];

try {
for (int i = 0; i < answerCount + answerRecordCount; i++) {
for (int i = 0; i < questionCount; i++) {
final _FQDNReadResult result =
_readFQDN(data, packetBytes, offset, length);
offset += result.bytesRead;
checkLength(offset + 4);
offset += 4;
}
for (int i = 0; i < remainingCount; i++) {
final ResourceRecord record = readResourceRecord();
if (record != null) {
result.add(record);
Expand Down
346 changes: 346 additions & 0 deletions packages/multicast_dns/test/decode_test.dart
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -122,6 +122,47 @@ void testValidPackages() {
),
]);
});

// Fixes https://github.com/flutter/flutter/issues/31854
test('Can decode packages with question, answer and additional', () {
final List<ResourceRecord> result =
decodeMDnsResponse(packetWithQuestionAnArCount);
expect(result, isNotNull);
expect(result.length, 2);
expect(result, <ResourceRecord>[
PtrResourceRecord(
'_______________.____._____',
result[0].validUntil,
domainName: '_______________________._______________.____._____',
),
PtrResourceRecord(
'_______________.____._____',
result[1].validUntil,
domainName: '____________________________._______________.____._____',
),
]);
});

// Fixes https://github.com/flutter/flutter/issues/31854
test('Can decode packages without question and with answer and additional',
() {
final List<ResourceRecord> result =
decodeMDnsResponse(packetWithoutQuestionWithAnArCount);
expect(result, isNotNull);
expect(result.length, 2);
expect(result, <ResourceRecord>[
PtrResourceRecord(
'_______________.____._____',
result[0].validUntil,
domainName: '______________________._______________.____._____',
),
TxtResourceRecord(
'_______________.____._____',
result[1].validUntil,
text: '\u{14}model=MacBookPro14,3\nosxvers=18\u{12}ecolor=225,225,223',
),
]);
});
}

void testBadPackages() {
Expand Down Expand Up @@ -832,3 +873,308 @@ const List<int> srvRData = <int>[
0x6c,
0x00
];

const List<int> packetWithQuestionAnArCount = <int>[
0,
0,
2,
0,
0,
1,
0,
1,
0,
0,
0,
1,
15,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
4,
95,
95,
95,
95,
5,
95,
95,
95,
95,
95,
0,
0,
12,
0,
1,
192,
12,
0,
12,
0,
1,
0,
0,
14,
13,
0,
26,
23,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
192,
12,
192,
12,
0,
12,
0,
1,
0,
0,
14,
13,
0,
31,
28,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
192,
12,
];

const List<int> packetWithoutQuestionWithAnArCount = <int>[
0,
0,
132,
0,
0,
0,
0,
1,
0,
0,
0,
1,
15,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
4,
95,
95,
95,
95,
5,
95,
95,
95,
95,
95,
0,
0,
12,
0,
1,
0,
0,
17,
148,
0,
25,
22,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
192,
12,
22,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
12,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
95,
192,
28,
0,
16,
0,
1,
0,
0,
17,
148,
0,
51,
20,
109,
111,
100,
101,
108,
61,
77,
97,
99,
66,
111,
111,
107,
80,
114,
111,
49,
52,
44,
51,
10,
111,
115,
120,
118,
101,
114,
115,
61,
49,
56,
18,
101,
99,
111,
108,
111,
114,
61,
50,
50,
53,
44,
50,
50,
53,
44,
50,
50,
51,
];