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Disk: ExtendedExtractor: Better header parsing

v0.3.0-dev
Paul Hollinsky 2022-03-03 20:19:33 -05:00
parent 0a15adbe91
commit adad9b3761
2 changed files with 34 additions and 26 deletions
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54
disk/extextractordiskreaddriver.cpp
View File

@ -38,44 +38,55 @@ optional<uint64_t> ExtExtractorDiskReadDriver::readLogicalDiskAligned(Communicat
uint16_t receiving = 0; // How much are we about to get before another header or completion
uint64_t received = 0;
uint16_t receivedCurrent = 0;
uint8_t gotHeaderBytes = 0;
std::vector<uint8_t> header;
std::unique_lock<std::mutex> lk(m);
bool error = !com.redirectRead([&](std::vector<uint8_t>&& data) {
std::unique_lock<std::mutex> lk2(m);
size_t offset = 0;
while(offset < data.size()) {
size_t left = data.size() - offset;
if(gotHeaderBytes != headerLength) {
if(gotHeaderBytes == 0 && left && data[offset] != 0xaa) {
if(header.size() != HeaderLength) {
if(header.empty() && left && data[offset] != 0xaa) {
#ifdef ICSNEO_EXTENDED_EXTRACTOR_DEBUG_PRINTS
std::cout << "Incorrect header " << int(data[offset]) << ' ' << int(offset) << std::endl;
#endif
offset++;
continue;
}
// Did we get a correct header and at least one byte of data?
if(int32_t(left) < (headerLength - gotHeaderBytes)) {
#ifdef ICSNEO_EXTENDED_EXTRACTOR_DEBUG_PRINTS
std::cout << "Got " << int(left) << " bytes of header at " << offset << std::endl;
#endif
gotHeaderBytes += uint8_t(left);
error = true;
lk2.unlock();
cv.notify_all();
return;
}
// Did we get a correct header and at least one byte of data?
const auto begin = data.begin() + offset;
int32_t headerLeft = int32_t(HeaderLength - header.size());
if(int32_t(left) < headerLeft) {
// Not enough data here, grab what header we can and continue
header.insert(header.end(), begin, data.end());
#ifdef ICSNEO_EXTENDED_EXTRACTOR_DEBUG_PRINTS
std::cout << "Got " << int(left) << " bytes of header at " << offset << " (incomplete " <<
header.size() << ')' << std::endl;
#endif
return;
}
header.insert(header.end(), begin, begin + headerLeft);
#ifdef ICSNEO_EXTENDED_EXTRACTOR_DEBUG_PRINTS
std::cout << "Got " << int(headerLeft) << " bytes of header at " << offset << " (complete " <<
header.size() << ')' << std::endl;
#endif
offset += headerLeft;
// The device tells us how much it's sending us before the next header
receiving = (data[offset + headerLength-2-gotHeaderBytes] | (data[offset + headerLength-1-gotHeaderBytes] << 8));
receiving = (header[5] | (header[6] << 8));
#ifdef ICSNEO_EXTENDED_EXTRACTOR_DEBUG_PRINTS
std::cout << "Started packet of size " << receiving << " bytes" << std::endl;
#endif
// Skip the header and any bytes necessary for unaligned read
offset += headerLength - gotHeaderBytes;
gotHeaderBytes = headerLength;
}
const auto available = left - offset;
auto count = uint16_t(std::min<uint64_t>(std::min<uint64_t>(receiving - receivedCurrent, available), amount - received));
left = data.size() - offset;
auto count = uint16_t(std::min<uint64_t>(std::min<uint64_t>(receiving - receivedCurrent, left), amount - received));
#ifdef ICSNEO_EXTENDED_EXTRACTOR_DEBUG_PRINTS
std::cout << "With " << int(left) << " bytes " << int(offset) << std::endl;
#endif
memcpy(cache.data() + received, data.data() + offset, count);
received += count;
receivedCurrent += count;
@ -84,6 +95,7 @@ optional<uint64_t> ExtExtractorDiskReadDriver::readLogicalDiskAligned(Communicat
if(amount == received) {
if(receivedCurrent % 2 == 0)
offset++;
header.clear(); // Now we will need another header
lk2.unlock();
cv.notify_all();
lk2.lock();
@ -98,7 +110,7 @@ optional<uint64_t> ExtExtractorDiskReadDriver::readLogicalDiskAligned(Communicat
#endif
if(receivedCurrent % 2 == 0)
offset++;
gotHeaderBytes = 0; // Now we will need another header
header.clear(); // Now we will need another header
receivedCurrent = 0;
} else {
#ifdef ICSNEO_EXTENDED_EXTRACTOR_DEBUG_PRINTS

6
include/icsneo/disk/extextractordiskreaddriver.h
View File

@ -22,19 +22,15 @@ public:
return { static_cast<uint32_t>(SectorSize), static_cast<uint32_t>(MaxSize) };
}
uint8_t getHeaderLength() const { return headerLength; }
void setHeaderLength(uint8_t length) { headerLength = length; }
private:
static constexpr const uint32_t MaxSize = Disk::SectorSize * 512;
static constexpr const std::chrono::seconds CacheTime = std::chrono::seconds(1);
static constexpr const uint8_t HeaderLength = 7;
std::array<uint8_t, MaxSize> cache;
uint64_t cachePos = 0;
std::chrono::time_point<std::chrono::steady_clock> cachedAt;
uint8_t headerLength = 7; // Correct for Ethernet
Access getPossibleAccess() const override { return Access::EntireCard; }
optional<uint64_t> readLogicalDiskAligned(Communication& com, device_eventhandler_t report,