Files
U2FDevice/IO.cpp

159 lines
3.8 KiB
C++

/*
U2FDevice - A program to allow Raspberry Pi Zeros to act as U2F tokens
Copyright (C) 2018 Michael Kuc
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
#include "IO.hpp"
#include "Macro.hpp"
#include "Streams.hpp"
#include "U2FDevice.hpp"
#include "u2f.hpp"
#include <android/log.h>
#include <array>
#include <chrono>
#include <cstdio>
#include <ctime>
#include <fcntl.h>
#include <iostream>
#include <memory>
#include <poll.h>
#include <ratio>
#include <stdexcept>
#include <string>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
using namespace std;
bool bytesAvailable(size_t count);
vector<uint8_t>& getBuffer();
#ifdef DEBUG_STREAMS
string cacheDirectory{ DEBUG_STREAMS };
#endif
#ifdef HID_SOCKET
string clientSocket{};
#endif
vector<uint8_t> readNonBlock(const size_t count) {
if (!bytesAvailable(count))
return vector<uint8_t>{};
auto& buffer = getBuffer();
auto buffStart = buffer.begin(), buffEnd = buffer.begin() + count;
vector<uint8_t> bytes{ buffStart, buffEnd };
buffer.erase(buffStart, buffEnd);
errno = 0;
return bytes;
}
void write(const vector<uint8_t>& bytes) {
size_t totalBytes = 0;
auto hostDescriptor = *getHostDescriptor();
while (totalBytes < bytes.size()) {
auto writtenBytes =
send(hostDescriptor, bytes.data() + totalBytes, bytes.size() - totalBytes, 0);
if (writtenBytes > 0)
totalBytes += writtenBytes;
else if (errno != 0 && errno != EAGAIN &&
errno != EWOULDBLOCK) // Expect file blocking behaviour
ERR();
}
errno = 0;
}
bool bytesAvailable(const size_t count) {
auto startTime = std::chrono::high_resolution_clock::now();
chrono::duration<double, milli> delay{ 0 };
while (delay.count() < U2FHID_TRANS_TIMEOUT) {
if (getBuffer().size() >= count) {
#ifdef DEBUG_MSGS
clog << "Requested " << count << " bytes" << endl;
#endif
return true;
}
delay = chrono::high_resolution_clock::now() - startTime;
}
#ifdef DEBUG_MSGS
cerr << "Failed to obtain " << count << " bytes, having " << getBuffer().size() << endl;
#endif
return false;
}
vector<uint8_t>& bufferVar() {
static vector<uint8_t> buffer{};
return buffer;
}
vector<uint8_t>& getBuffer() {
const timespec delay{ 0, 10'000'000 };
auto& buff = bufferVar();
array<uint8_t, HID_RPT_SIZE> bytes{};
auto hostDescriptor = *getHostDescriptor();
pollfd pFD{ hostDescriptor, POLLIN };
while (true) {
ppoll(&pFD, 1, &delay, 0);
if (pFD.revents & POLLIN) {
auto readByteCount = recv(hostDescriptor, bytes.data(), HID_RPT_SIZE, 0);
if (readByteCount > 0 && readByteCount != HID_RPT_SIZE) {
// Failed to copy an entire packet in, so log this packet
#ifdef DEBUG_MSGS
cerr << "Only retrieved " << readByteCount << " bytes from expected full packet."
<< endl;
#endif
}
if (readByteCount > 0) {
copy(bytes.begin(), bytes.begin() + readByteCount, back_inserter(buff));
#ifdef DEBUG_STREAMS
fwrite(bytes.data(), 1, readByteCount, getComHostStream().get());
#endif
} else if (errno != EAGAIN && errno != EWOULDBLOCK) // Expect read would block
{
ERR();
#ifdef DEBUG_MSGS
cerr << "Unknown stream error: " << errno << endl;
#endif
break;
} else {
errno = 0;
break; // Escape loop if blocking would occur
}
} else
break;
}
return buff;
}