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#pragma once
#include "app.hpp"
#include "websocket.hpp"
#include <boost/beast/core/flat_static_buffer.hpp>
#include <boost/process/async_pipe.hpp>
#include <boost/process/child.hpp>
#include <boost/process/io.hpp>
#include <csignal>
namespace crow
{
namespace obmc_vm
{
// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
static crow::websocket::Connection* session = nullptr;
// The max network block device buffer size is 128kb plus 16bytes
// for the message header:
// https://github.com/NetworkBlockDevice/nbd/blob/master/doc/proto.md#simple-reply-message
static constexpr auto nbdBufferSize = (128 * 1024 + 16) * 4;
class Handler : public std::enable_shared_from_this<Handler>
{
public:
Handler(const std::string& mediaIn, boost::asio::io_context& ios) :
pipeOut(ios), pipeIn(ios), media(mediaIn),
outputBuffer(new boost::beast::flat_static_buffer<nbdBufferSize>),
inputBuffer(new boost::beast::flat_static_buffer<nbdBufferSize>)
{}
~Handler() = default;
Handler(const Handler&) = delete;
Handler(Handler&&) = delete;
Handler& operator=(const Handler&) = delete;
Handler& operator=(Handler&&) = delete;
void doClose()
{
// boost::process::child::terminate uses SIGKILL, need to send SIGTERM
// to allow the proxy to stop nbd-client and the USB device gadget.
int rc = kill(proxy.id(), SIGTERM);
if (rc != 0)
{
BMCWEB_LOG_ERROR("Failed to terminate nbd-proxy: {}", errno);
return;
}
proxy.wait();
}
void connect()
{
std::error_code ec;
proxy = boost::process::child("/usr/sbin/nbd-proxy", media,
boost::process::std_out > pipeOut,
boost::process::std_in < pipeIn, ec);
if (ec)
{
BMCWEB_LOG_ERROR("Couldn't connect to nbd-proxy: {}", ec.message());
if (session != nullptr)
{
session->close("Error connecting to nbd-proxy");
}
return;
}
doWrite();
doRead();
}
void doWrite()
{
if (doingWrite)
{
BMCWEB_LOG_DEBUG("Already writing. Bailing out");
return;
}
if (inputBuffer->size() == 0)
{
BMCWEB_LOG_DEBUG("inputBuffer empty. Bailing out");
return;
}
doingWrite = true;
pipeIn.async_write_some(
inputBuffer->data(),
[this, self(shared_from_this())](const boost::beast::error_code& ec,
std::size_t bytesWritten) {
BMCWEB_LOG_DEBUG("Wrote {}bytes", bytesWritten);
doingWrite = false;
inputBuffer->consume(bytesWritten);
if (session == nullptr)
{
return;
}
if (ec == boost::asio::error::eof)
{
session->close("VM socket port closed");
return;
}
if (ec)
{
session->close("Error in writing to proxy port");
BMCWEB_LOG_ERROR("Error in VM socket write {}", ec);
return;
}
doWrite();
});
}
void doRead()
{
std::size_t bytes = outputBuffer->capacity() - outputBuffer->size();
pipeOut.async_read_some(
outputBuffer->prepare(bytes),
[this, self(shared_from_this())](
const boost::system::error_code& ec, std::size_t bytesRead) {
BMCWEB_LOG_DEBUG("Read done. Read {} bytes", bytesRead);
if (ec)
{
BMCWEB_LOG_ERROR("Couldn't read from VM port: {}", ec);
if (session != nullptr)
{
session->close("Error in connecting to VM port");
}
return;
}
if (session == nullptr)
{
return;
}
outputBuffer->commit(bytesRead);
std::string_view payload(
static_cast<const char*>(outputBuffer->data().data()),
bytesRead);
session->sendBinary(payload);
outputBuffer->consume(bytesRead);
doRead();
});
}
boost::process::async_pipe pipeOut;
boost::process::async_pipe pipeIn;
boost::process::child proxy;
std::string media;
bool doingWrite{false};
std::unique_ptr<boost::beast::flat_static_buffer<nbdBufferSize>>
outputBuffer;
std::unique_ptr<boost::beast::flat_static_buffer<nbdBufferSize>>
inputBuffer;
};
// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
static std::shared_ptr<Handler> handler;
inline void requestRoutes(App& app)
{
BMCWEB_ROUTE(app, "/vm/0/0")
.privileges({{"ConfigureComponents", "ConfigureManager"}})
.websocket()
.onopen([](crow::websocket::Connection& conn) {
BMCWEB_LOG_DEBUG("Connection {} opened", logPtr(&conn));
if (session != nullptr)
{
conn.close("Session already connected");
return;
}
if (handler != nullptr)
{
conn.close("Handler already running");
return;
}
session = &conn;
// media is the last digit of the endpoint /vm/0/0. A future
// enhancement can include supporting different endpoint values.
const char* media = "0";
handler = std::make_shared<Handler>(media, conn.getIoContext());
handler->connect();
})
.onclose([](crow::websocket::Connection& conn,
const std::string& /*reason*/) {
if (&conn != session)
{
return;
}
session = nullptr;
handler->doClose();
handler->inputBuffer->clear();
handler->outputBuffer->clear();
handler.reset();
})
.onmessage([](crow::websocket::Connection& conn,
const std::string& data, bool) {
if (data.length() >
handler->inputBuffer->capacity() - handler->inputBuffer->size())
{
BMCWEB_LOG_ERROR("Buffer overrun when writing {} bytes",
data.length());
conn.close("Buffer overrun");
return;
}
boost::asio::buffer_copy(handler->inputBuffer->prepare(data.size()),
boost::asio::buffer(data));
handler->inputBuffer->commit(data.size());
handler->doWrite();
});
}
} // namespace obmc_vm
} // namespace crow
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