//===-- PipeWindows.cpp ---------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "lldb/Host/windows/PipeWindows.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Support/Process.h"
#include "llvm/Support/raw_ostream.h"
#include <fcntl.h>
#include <io.h>
#include <rpc.h>
#include <atomic>
#include <string>
using namespace lldb;
using namespace lldb_private;
static std::atomic<uint32_t> g_pipe_serial(0);
static constexpr llvm::StringLiteral g_pipe_name_prefix = "\\\\.\\Pipe\\";
PipeWindows::PipeWindows()
: m_read(INVALID_HANDLE_VALUE), m_write(INVALID_HANDLE_VALUE),
m_read_fd(PipeWindows::kInvalidDescriptor),
m_write_fd(PipeWindows::kInvalidDescriptor) {
ZeroMemory(&m_read_overlapped, sizeof(m_read_overlapped));
ZeroMemory(&m_write_overlapped, sizeof(m_write_overlapped));
}
PipeWindows::PipeWindows(pipe_t read, pipe_t write)
: m_read((HANDLE)read), m_write((HANDLE)write),
m_read_fd(PipeWindows::kInvalidDescriptor),
m_write_fd(PipeWindows::kInvalidDescriptor) {
assert(read != LLDB_INVALID_PIPE || write != LLDB_INVALID_PIPE);
// Don't risk in passing file descriptors and getting handles from them by
// _get_osfhandle since the retrieved handles are highly likely unrecognized
// in the current process and usually crashes the program. Pass handles
// instead since the handle can be inherited.
if (read != LLDB_INVALID_PIPE) {
m_read_fd = _open_osfhandle((intptr_t)read, _O_RDONLY);
// Make sure the fd and native handle are consistent.
if (m_read_fd < 0)
m_read = INVALID_HANDLE_VALUE;
}
if (write != LLDB_INVALID_PIPE) {
m_write_fd = _open_osfhandle((intptr_t)write, _O_WRONLY);
if (m_write_fd < 0)
m_write = INVALID_HANDLE_VALUE;
}
ZeroMemory(&m_read_overlapped, sizeof(m_read_overlapped));
m_read_overlapped.hEvent = ::CreateEventA(nullptr, TRUE, FALSE, nullptr);
ZeroMemory(&m_write_overlapped, sizeof(m_write_overlapped));
m_write_overlapped.hEvent = ::CreateEventA(nullptr, TRUE, FALSE, nullptr);
}
PipeWindows::~PipeWindows() { Close(); }
Status PipeWindows::CreateNew(bool child_process_inherit) {
// Even for anonymous pipes, we open a named pipe. This is because you
// cannot get overlapped i/o on Windows without using a named pipe. So we
// synthesize a unique name.
uint32_t serial = g_pipe_serial.fetch_add(1);
std::string pipe_name;
llvm::raw_string_ostream pipe_name_stream(pipe_name);
pipe_name_stream << "lldb.pipe." << ::GetCurrentProcessId() << "." << serial;
pipe_name_stream.flush();
return CreateNew(pipe_name.c_str(), child_process_inherit);
}
Status PipeWindows::CreateNew(llvm::StringRef name,
bool child_process_inherit) {
if (name.empty())
return Status(ERROR_INVALID_PARAMETER, eErrorTypeWin32);
if (CanRead() || CanWrite())
return Status(ERROR_ALREADY_EXISTS, eErrorTypeWin32);
std::string pipe_path = g_pipe_name_prefix.str();
pipe_path.append(name.str());
SECURITY_ATTRIBUTES sa{sizeof(SECURITY_ATTRIBUTES), 0,
child_process_inherit ? TRUE : FALSE};
// Always open for overlapped i/o. We implement blocking manually in Read
// and Write.
DWORD read_mode = FILE_FLAG_OVERLAPPED;
m_read =
::CreateNamedPipeA(pipe_path.c_str(), PIPE_ACCESS_INBOUND | read_mode,
PIPE_TYPE_BYTE | PIPE_WAIT, /*nMaxInstances=*/1,
/*nOutBufferSize=*/1024,
/*nInBufferSize=*/1024,
/*nDefaultTimeOut=*/0, &sa);
if (INVALID_HANDLE_VALUE == m_read)
return Status(::GetLastError(), eErrorTypeWin32);
m_read_fd = _open_osfhandle((intptr_t)m_read, _O_RDONLY);
ZeroMemory(&m_read_overlapped, sizeof(m_read_overlapped));
m_read_overlapped.hEvent = ::CreateEvent(nullptr, TRUE, FALSE, nullptr);
// Open the write end of the pipe. Note that closing either the read or
// write end of the pipe could directly close the pipe itself.
Status result = OpenNamedPipe(name, child_process_inherit, false);
if (!result.Success()) {
CloseReadFileDescriptor();
return result;
}
return result;
}
Status PipeWindows::CreateWithUniqueName(llvm::StringRef prefix,
bool child_process_inherit,
llvm::SmallVectorImpl<char> &name) {
llvm::SmallString<128> pipe_name;
Status error;
::UUID unique_id;
RPC_CSTR unique_string;
RPC_STATUS status = ::UuidCreate(&unique_id);
if (status == RPC_S_OK || status == RPC_S_UUID_LOCAL_ONLY)
status = ::UuidToStringA(&unique_id, &unique_string);
if (status == RPC_S_OK) {
pipe_name = prefix;
pipe_name += "-";
pipe_name += reinterpret_cast<char *>(unique_string);
::RpcStringFreeA(&unique_string);
error = CreateNew(pipe_name, child_process_inherit);
} else {
error = Status(status, eErrorTypeWin32);
}
if (error.Success())
name = pipe_name;
return error;
}
Status PipeWindows::OpenAsReader(llvm::StringRef name,
bool child_process_inherit) {
if (CanRead())
return Status(); // Note the name is ignored.
return OpenNamedPipe(name, child_process_inherit, true);
}
Status
PipeWindows::OpenAsWriterWithTimeout(llvm::StringRef name,
bool child_process_inherit,
const std::chrono::microseconds &timeout) {
if (CanWrite())
return Status(); // Note the name is ignored.
return OpenNamedPipe(name, child_process_inherit, false);
}
Status PipeWindows::OpenNamedPipe(llvm::StringRef name,
bool child_process_inherit, bool is_read) {
if (name.empty())
return Status(ERROR_INVALID_PARAMETER, eErrorTypeWin32);
assert(is_read ? !CanRead() : !CanWrite());
SECURITY_ATTRIBUTES attributes{sizeof(SECURITY_ATTRIBUTES), 0,
child_process_inherit ? TRUE : FALSE};
std::string pipe_path = g_pipe_name_prefix.str();
pipe_path.append(name.str());
if (is_read) {
m_read = ::CreateFileA(pipe_path.c_str(), GENERIC_READ, 0, &attributes,
OPEN_EXISTING, FILE_FLAG_OVERLAPPED, NULL);
if (INVALID_HANDLE_VALUE == m_read)
return Status(::GetLastError(), eErrorTypeWin32);
m_read_fd = _open_osfhandle((intptr_t)m_read, _O_RDONLY);
ZeroMemory(&m_read_overlapped, sizeof(m_read_overlapped));
m_read_overlapped.hEvent = ::CreateEvent(nullptr, TRUE, FALSE, nullptr);
} else {
m_write = ::CreateFileA(pipe_path.c_str(), GENERIC_WRITE, 0, &attributes,
OPEN_EXISTING, FILE_FLAG_OVERLAPPED, NULL);
if (INVALID_HANDLE_VALUE == m_write)
return Status(::GetLastError(), eErrorTypeWin32);
m_write_fd = _open_osfhandle((intptr_t)m_write, _O_WRONLY);
ZeroMemory(&m_write_overlapped, sizeof(m_write_overlapped));
m_write_overlapped.hEvent = ::CreateEventA(nullptr, TRUE, FALSE, nullptr);
}
return Status();
}
int PipeWindows::GetReadFileDescriptor() const { return m_read_fd; }
int PipeWindows::GetWriteFileDescriptor() const { return m_write_fd; }
int PipeWindows::ReleaseReadFileDescriptor() {
if (!CanRead())
return PipeWindows::kInvalidDescriptor;
int result = m_read_fd;
m_read_fd = PipeWindows::kInvalidDescriptor;
if (m_read_overlapped.hEvent)
::CloseHandle(m_read_overlapped.hEvent);
m_read = INVALID_HANDLE_VALUE;
ZeroMemory(&m_read_overlapped, sizeof(m_read_overlapped));
return result;
}
int PipeWindows::ReleaseWriteFileDescriptor() {
if (!CanWrite())
return PipeWindows::kInvalidDescriptor;
int result = m_write_fd;
m_write_fd = PipeWindows::kInvalidDescriptor;
if (m_write_overlapped.hEvent)
::CloseHandle(m_write_overlapped.hEvent);
m_write = INVALID_HANDLE_VALUE;
ZeroMemory(&m_write_overlapped, sizeof(m_write_overlapped));
return result;
}
void PipeWindows::CloseReadFileDescriptor() {
if (!CanRead())
return;
if (m_read_overlapped.hEvent)
::CloseHandle(m_read_overlapped.hEvent);
_close(m_read_fd);
m_read = INVALID_HANDLE_VALUE;
m_read_fd = PipeWindows::kInvalidDescriptor;
ZeroMemory(&m_read_overlapped, sizeof(m_read_overlapped));
}
void PipeWindows::CloseWriteFileDescriptor() {
if (!CanWrite())
return;
if (m_write_overlapped.hEvent)
::CloseHandle(m_write_overlapped.hEvent);
_close(m_write_fd);
m_write = INVALID_HANDLE_VALUE;
m_write_fd = PipeWindows::kInvalidDescriptor;
ZeroMemory(&m_write_overlapped, sizeof(m_write_overlapped));
}
void PipeWindows::Close() {
CloseReadFileDescriptor();
CloseWriteFileDescriptor();
}
Status PipeWindows::Delete(llvm::StringRef name) { return Status(); }
bool PipeWindows::CanRead() const { return (m_read != INVALID_HANDLE_VALUE); }
bool PipeWindows::CanWrite() const { return (m_write != INVALID_HANDLE_VALUE); }
HANDLE
PipeWindows::GetReadNativeHandle() { return m_read; }
HANDLE
PipeWindows::GetWriteNativeHandle() { return m_write; }
Status PipeWindows::ReadWithTimeout(void *buf, size_t size,
const std::chrono::microseconds &duration,
size_t &bytes_read) {
if (!CanRead())
return Status(ERROR_INVALID_HANDLE, eErrorTypeWin32);
bytes_read = 0;
DWORD sys_bytes_read = 0;
BOOL result =
::ReadFile(m_read, buf, size, &sys_bytes_read, &m_read_overlapped);
if (result) {
bytes_read = sys_bytes_read;
return Status();
}
DWORD failure_error = ::GetLastError();
if (failure_error != ERROR_IO_PENDING)
return Status(failure_error, eErrorTypeWin32);
DWORD timeout = (duration == std::chrono::microseconds::zero())
? INFINITE
: duration.count() / 1000;
DWORD wait_result = ::WaitForSingleObject(m_read_overlapped.hEvent, timeout);
if (wait_result != WAIT_OBJECT_0) {
// The operation probably failed. However, if it timed out, we need to
// cancel the I/O. Between the time we returned from WaitForSingleObject
// and the time we call CancelIoEx, the operation may complete. If that
// hapens, CancelIoEx will fail and return ERROR_NOT_FOUND. If that
// happens, the original operation should be considered to have been
// successful.
bool failed = true;
failure_error = ::GetLastError();
if (wait_result == WAIT_TIMEOUT) {
BOOL cancel_result = ::CancelIoEx(m_read, &m_read_overlapped);
if (!cancel_result && ::GetLastError() == ERROR_NOT_FOUND)
failed = false;
}
if (failed)
return Status(failure_error, eErrorTypeWin32);
}
// Now we call GetOverlappedResult setting bWait to false, since we've
// already waited as long as we're willing to.
if (!::GetOverlappedResult(m_read, &m_read_overlapped, &sys_bytes_read,
FALSE))
return Status(::GetLastError(), eErrorTypeWin32);
bytes_read = sys_bytes_read;
return Status();
}
Status PipeWindows::WriteWithTimeout(const void *buf, size_t size,
const std::chrono::microseconds &duration,
size_t &bytes_written) {
if (!CanWrite())
return Status(ERROR_INVALID_HANDLE, eErrorTypeWin32);
bytes_written = 0;
DWORD sys_bytes_write = 0;
BOOL result =
::WriteFile(m_write, buf, size, &sys_bytes_write, &m_write_overlapped);
if (result) {
bytes_written = sys_bytes_write;
return Status();
}
DWORD failure_error = ::GetLastError();
if (failure_error != ERROR_IO_PENDING)
return Status(failure_error, eErrorTypeWin32);
DWORD timeout = (duration == std::chrono::microseconds::zero())
? INFINITE
: duration.count() / 1000;
DWORD wait_result = ::WaitForSingleObject(m_write_overlapped.hEvent, timeout);
if (wait_result != WAIT_OBJECT_0) {
// The operation probably failed. However, if it timed out, we need to
// cancel the I/O. Between the time we returned from WaitForSingleObject
// and the time we call CancelIoEx, the operation may complete. If that
// hapens, CancelIoEx will fail and return ERROR_NOT_FOUND. If that
// happens, the original operation should be considered to have been
// successful.
bool failed = true;
failure_error = ::GetLastError();
if (wait_result == WAIT_TIMEOUT) {
BOOL cancel_result = ::CancelIoEx(m_write, &m_write_overlapped);
if (!cancel_result && ::GetLastError() == ERROR_NOT_FOUND)
failed = false;
}
if (failed)
return Status(failure_error, eErrorTypeWin32);
}
// Now we call GetOverlappedResult setting bWait to false, since we've
// already waited as long as we're willing to.
if (!::GetOverlappedResult(m_write, &m_write_overlapped, &sys_bytes_write,
FALSE))
return Status(::GetLastError(), eErrorTypeWin32);
bytes_written = sys_bytes_write;
return Status();
}
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