Cleanup and add guards against malformed MIDS files

This commit is contained in:
Cacodemon345 2020-09-14 15:38:26 +06:00
parent 5bfa76c948
commit bff02053be
2 changed files with 26 additions and 20 deletions

View file

@ -240,7 +240,7 @@ protected:
uint32_t *MakeEvents(uint32_t *events, uint32_t *max_events_p, uint32_t max_time) override;
private:
std::vector<uint32_t> midiBuffer;
std::vector<uint32_t> MidsBuffer;
size_t MidsP, MaxMidsP;
int FormatFlags;

View file

@ -1,6 +1,6 @@
/*
** midisource_mids.cpp
** Code to let ZDoom play MIDS MIDI music through the MIDI streaming API.
** Code to let ZMusic play MIDS MIDI music through the MIDI streaming API.
**
**---------------------------------------------------------------------------
** Copyright 2020 Cacodemon345
@ -66,11 +66,19 @@
MIDSSong::MIDSSong(const uint8_t* data, size_t len)
{
if (len <= 52)
return;
if ((len % 4) != 0)
return;
// Validate the header first.
if (data[12] != 'f' || data[13] != 'm' || data[14] != 't' || data[15] != ' ')
{
return;
}
int headerSize = LittleLong(GetInt(&data[16]));
if (headerSize != 12) return;
Division = LittleLong(GetInt(&data[20]));
FormatFlags = LittleLong(GetInt(&data[28]));
// Validate the data chunk.
@ -79,22 +87,21 @@ MIDSSong::MIDSSong(const uint8_t* data, size_t len)
return;
}
int NumBlocks = LittleLong(GetInt(&data[40]));
const uint8_t* midiData = &data[44];
const uint32_t* midiData = (const uint32_t*)&data[44];
uint32_t tkStart = 0;
uint32_t cbBuffer = 0;
while (NumBlocks-- > 0)
{
tkStart = LittleLong(GetInt(midiData));
cbBuffer = LittleLong(GetInt(midiData + 4));
std::vector<uint32_t> midiMessageData;
midiMessageData.resize(cbBuffer / 4);
memcpy(midiMessageData.data(), midiData + 8, cbBuffer);
midiBuffer.insert(midiBuffer.end(), midiMessageData.begin(), midiMessageData.end());
midiData += 8 + cbBuffer;
tkStart = LittleLong(*midiData);
cbBuffer = LittleLong(*(midiData + 1));
midiData += 2;
if ((cbBuffer % (FormatFlags ? 8 : 12)) != 0) return;
MidsBuffer.insert(MidsBuffer.end(), midiData, midiData + (cbBuffer / 4));
midiData += cbBuffer / 4;
}
MidsP = 0;
MaxMidsP = midiBuffer.size() - 1;
for (auto& curMidiData : midiBuffer)
MaxMidsP = MidsBuffer.size() - 1;
for (auto& curMidiData : MidsBuffer)
{
curMidiData = LittleLong(curMidiData);
}
@ -151,9 +158,9 @@ void MIDSSong::DoRestart()
void MIDSSong::ProcessInitialTempoEvents()
{
if (MEVENT_EVENTTYPE(midiBuffer[FormatFlags ? 1 : 2]) == MEVENT_TEMPO)
if (MEVENT_EVENTTYPE(MidsBuffer[FormatFlags ? 1 : 2]) == MEVENT_TEMPO)
{
SetTempo(MEVENT_EVENTPARM(midiBuffer[FormatFlags ? 1 : 2]));
SetTempo(MEVENT_EVENTPARM(MidsBuffer[FormatFlags ? 1 : 2]));
}
}
@ -174,13 +181,12 @@ uint32_t* MIDSSong::MakeEvents(uint32_t* events, uint32_t* max_event_p, uint32_t
max_time = max_time * Division / Tempo;
while (events < max_event_p && tot_time <= max_time)
{
events[0] = time = midiBuffer[MidsP++];
events[1] = FormatFlags ? 0 : midiBuffer[MidsP++];
events[2] = midiBuffer[MidsP++];
events[0] = time = MidsBuffer[MidsP++];
events[1] = FormatFlags ? 0 : MidsBuffer[MidsP++];
events[2] = MidsBuffer[MidsP++];
events += 3;
tot_time += time;
if (MidsP >= MaxMidsP) goto end;
if (MidsP >= MaxMidsP) break;
}
end:
return events;
}