espressif/openthread
1
0
Fork 0
mirror of https://github.com/espressif/openthread.git synced 2026-10-03 14:27:38 +00:00
Code Issues Packages Projects Releases Wiki Activity

[dns] add checks for multi-label looped compressed DNS names (#10215)

Browse Source 
This commit enhances `Dns::Name` to detect and handle cases where a
compressed DNS name contains a loop spanning multiple labels. The
`test_dns` unit test has been updated to include test cases for these
invalid names.
This commit is contained in:
Abtin Keshavarzian
2024-05-08 18:56:02 -07:00
committed by GitHub
parent 226f239c5d
commit 8e3f51da84
3 changed files with 83 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files
tests/unit/test_dns.cpp
+79
View File
@@ -1031,6 +1031,85 @@ void TestDnsCompressedName(void)
printf("- Name3 after `AppendTo()`: \"%s\"\n", name);
// `ReadName()` for name-4 will fail due to first label containing dot char.
printf("----------------------------------------------------------------\n");
printf("Improperly formatted names (looped)\n");
{
// Pointer label jumps forward to offset 6.
static const uint8_t kEncodedName[] = {3, 'F', 'O', 'O', 0xc0, 6, 2, 'A', 'B', 0};
SuccessOrQuit(message->SetLength(0));
SuccessOrQuit(message->Append(kEncodedName));
DumpBuffer("pointer-moving-forward", kEncodedName, sizeof(kEncodedName));
offset = 0;
VerifyOrQuit(Dns::Name::ParseName(*message, offset) == kErrorParse);
VerifyOrQuit(Dns::Name::ReadName(*message, offset, name) == kErrorParse);
}
{
// Pointer label jumps back to offset 0 creating a loop.
static const uint8_t kEncodedName[] = {0xc0, 0};
SuccessOrQuit(message->SetLength(0));
SuccessOrQuit(message->Append(kEncodedName));
DumpBuffer("looped-name", kEncodedName, sizeof(kEncodedName));
offset = 0;
VerifyOrQuit(Dns::Name::ParseName(*message, offset) == kErrorParse);
VerifyOrQuit(Dns::Name::ReadName(*message, offset, name) == kErrorParse);
}
{
// After first label, we have a pointer label jumping back to
// offset 0, creating a loop.
static const uint8_t kEncodedName[] = {3, 'F', 'O', 'O', 0xc0, 0};
SuccessOrQuit(message->SetLength(0));
SuccessOrQuit(message->Append(kEncodedName));
DumpBuffer("looped-one-label", kEncodedName, sizeof(kEncodedName));
offset = 0;
VerifyOrQuit(Dns::Name::ParseName(*message, offset) == kErrorParse);
VerifyOrQuit(Dns::Name::ReadName(*message, offset, name) == kErrorParse);
VerifyOrQuit(Dns::Name::CompareName(*message, offset, "FOO.") == kErrorParse);
}
{
// After two labels we have a pointer label jumping back to
// start of the first label. Name itself starts at offset 3
// (first 3 bytes are unused).
static const uint8_t kEncodedName[] = {0, 0, 0, 3, 'F', 'O', 'O', 2, 'B', 'A', 0xc0, 3};
SuccessOrQuit(message->SetLength(0));
SuccessOrQuit(message->Append(kEncodedName));
DumpBuffer("looped-two-labels", kEncodedName, sizeof(kEncodedName));
offset = 3;
VerifyOrQuit(Dns::Name::ParseName(*message, offset) == kErrorParse);
VerifyOrQuit(Dns::Name::ReadName(*message, offset, name) == kErrorParse);
VerifyOrQuit(Dns::Name::CompareName(*message, offset, "FOO.BA.") == kErrorParse);
}
{
// Same as last case, but pointer label now points to
// immediately before the first label (at offset 2). The name
// is now valid.
static const uint8_t kEncodedName[] = {0, 0, 0, 3, 'F', 'O', 'O', 2, 'B', 'A', 0xc0, 2};
SuccessOrQuit(message->SetLength(0));
SuccessOrQuit(message->Append(kEncodedName));
DumpBuffer("valid-name", kEncodedName, sizeof(kEncodedName));
offset = 3;
SuccessOrQuit(Dns::Name::ParseName(*message, offset));
VerifyOrQuit(offset == sizeof(kEncodedName));
offset = 3;
SuccessOrQuit(Dns::Name::ReadName(*message, offset, name));
VerifyOrQuit(offset == sizeof(kEncodedName));
VerifyOrQuit(strcmp(name, "FOO.BA.") == 0);
printf("Read name =\"%s\"\n", name);
}
message->Free();
message2->Free();
testFreeInstance(instance);