llvm-project/lldb/tools/lldb-server/Acceptor.cpp

//===-- Acceptor.cpp --------------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "Acceptor.h"

#include "llvm/ADT/StringRef.h"

#include "lldb/Core/StreamString.h"
#include "lldb/Host/ConnectionFileDescriptor.h"
#include "lldb/Host/common/TCPSocket.h"

#include "Utility/UriParser.h"

using namespace lldb;
using namespace lldb_private;
using namespace lldb_private::lldb_server;
using namespace llvm;

namespace {

struct SocketScheme
{
    const char* m_scheme;
    const Socket::SocketProtocol m_protocol;
};

SocketScheme socket_schemes[] = {
    {"tcp", Socket::ProtocolTcp},
    {"udp", Socket::ProtocolUdp},
    {"unix", Socket::ProtocolUnixDomain},
    {"unix-abstract", Socket::ProtocolUnixAbstract},
};

bool
FindProtocolByScheme(const char* scheme, Socket::SocketProtocol& protocol)
{
    for (auto s: socket_schemes)
    {
        if (!strcmp(s.m_scheme, scheme))
        {
            protocol = s.m_protocol;
            return true;
        }
    }
    return false;
}

const char*
FindSchemeByProtocol(const Socket::SocketProtocol protocol)
{
    for (auto s: socket_schemes)
    {
        if (s.m_protocol == protocol)
            return s.m_scheme;
    }
    return nullptr;
}

}

Error
Acceptor::Listen(int backlog)
{
    return m_listener_socket_up->Listen(StringRef(m_name.c_str()),
                                        backlog);
}

Error
Acceptor::Accept(const bool child_processes_inherit, Connection *&conn)
{
    Socket* conn_socket = nullptr;
    auto error = m_listener_socket_up->Accept(StringRef(m_name.c_str()),
                                              child_processes_inherit,
                                              conn_socket);
    if (error.Success())
        conn = new ConnectionFileDescriptor(conn_socket);

    return error;
}

Socket::SocketProtocol
Acceptor::GetSocketProtocol() const
{
    return m_listener_socket_up->GetSocketProtocol();
}

const char*
Acceptor::GetSocketScheme() const
{
    return FindSchemeByProtocol(GetSocketProtocol());
}

std::string
Acceptor::GetLocalSocketId() const
{
    return m_local_socket_id();
}

std::unique_ptr<Acceptor>
Acceptor::Create(StringRef name, const bool child_processes_inherit, Error &error)
{
    error.Clear();

    Socket::SocketProtocol socket_protocol = Socket::ProtocolUnixDomain;
    int port;
    std::string scheme, host, path;
    // Try to match socket name as URL - e.g., tcp://localhost:5555
    if (UriParser::Parse(name.str(), scheme, host, port, path))
    {
        if (!FindProtocolByScheme(scheme.c_str(), socket_protocol))
            error.SetErrorStringWithFormat("Unknown protocol scheme \"%s\"", scheme.c_str());
        else
            name = name.drop_front(scheme.size() + strlen("://"));
    }
    else
    {
        std::string host_str;
        std::string port_str;
        int32_t port = INT32_MIN;
        // Try to match socket name as $host:port - e.g., localhost:5555
        if (Socket::DecodeHostAndPort (name, host_str, port_str, port, nullptr))
            socket_protocol = Socket::ProtocolTcp;
    }

    if (error.Fail())
        return std::unique_ptr<Acceptor>();

    std::unique_ptr<Socket> listener_socket_up = Socket::Create(
        socket_protocol, child_processes_inherit, error);

    LocalSocketIdFunc local_socket_id;
    if (error.Success())
    {
        if (listener_socket_up->GetSocketProtocol() == Socket::ProtocolTcp)
        {
            TCPSocket* tcp_socket = static_cast<TCPSocket*>(listener_socket_up.get());
            local_socket_id = [tcp_socket]() {
                auto local_port = tcp_socket->GetLocalPortNumber();
                return (local_port != 0) ? std::to_string(local_port) : "";
            };
        }
        else
        {
            const std::string socket_name = name;
            local_socket_id = [socket_name](){
                return socket_name;
            };
        }

        return std::unique_ptr<Acceptor>(
            new Acceptor(std::move(listener_socket_up), name, local_socket_id));
    }

    return std::unique_ptr<Acceptor>();
}

Acceptor::Acceptor(std::unique_ptr<Socket> &&listener_socket,
                   StringRef name,
                   const LocalSocketIdFunc &local_socket_id)
    : m_listener_socket_up(std::move(listener_socket)),
      m_name(name.str()),
      m_local_socket_id(local_socket_id)
{
}