1//===-- Acceptor.cpp --------------------------------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "Acceptor.h"
10
11#include "llvm/ADT/StringRef.h"
12#include "llvm/Support/ScopedPrinter.h"
13
14#include "lldb/Host/ConnectionFileDescriptor.h"
15#include "lldb/Host/common/TCPSocket.h"
16#include "lldb/Utility/StreamString.h"
17#include "lldb/Utility/UriParser.h"
18#include <optional>
19
20using namespace lldb;
21using namespace lldb_private;
22using namespace lldb_private::lldb_server;
23using namespace llvm;
24
25namespace {
26
27struct SocketScheme {
28  const char *m_scheme;
29  const Socket::SocketProtocol m_protocol;
30};
31
32SocketScheme socket_schemes[] = {
33    {"tcp", Socket::ProtocolTcp},
34    {"udp", Socket::ProtocolUdp},
35    {"unix", Socket::ProtocolUnixDomain},
36    {"unix-abstract", Socket::ProtocolUnixAbstract},
37};
38
39bool FindProtocolByScheme(const char *scheme,
40                          Socket::SocketProtocol &protocol) {
41  for (auto s : socket_schemes) {
42    if (!strcmp(s.m_scheme, scheme)) {
43      protocol = s.m_protocol;
44      return true;
45    }
46  }
47  return false;
48}
49
50const char *FindSchemeByProtocol(const Socket::SocketProtocol protocol) {
51  for (auto s : socket_schemes) {
52    if (s.m_protocol == protocol)
53      return s.m_scheme;
54  }
55  return nullptr;
56}
57}
58
59Status Acceptor::Listen(int backlog) {
60  return m_listener_socket_up->Listen(StringRef(m_name), backlog);
61}
62
63Status Acceptor::Accept(const bool child_processes_inherit, Connection *&conn) {
64  Socket *conn_socket = nullptr;
65  auto error = m_listener_socket_up->Accept(conn_socket);
66  if (error.Success())
67    conn = new ConnectionFileDescriptor(conn_socket);
68
69  return error;
70}
71
72Socket::SocketProtocol Acceptor::GetSocketProtocol() const {
73  return m_listener_socket_up->GetSocketProtocol();
74}
75
76const char *Acceptor::GetSocketScheme() const {
77  return FindSchemeByProtocol(GetSocketProtocol());
78}
79
80std::string Acceptor::GetLocalSocketId() const { return m_local_socket_id(); }
81
82std::unique_ptr<Acceptor> Acceptor::Create(StringRef name,
83                                           const bool child_processes_inherit,
84                                           Status &error) {
85  error.Clear();
86
87  Socket::SocketProtocol socket_protocol = Socket::ProtocolUnixDomain;
88  // Try to match socket name as URL - e.g., tcp://localhost:5555
89  if (std::optional<URI> res = URI::Parse(name)) {
90    if (!FindProtocolByScheme(res->scheme.str().c_str(), socket_protocol))
91      error.SetErrorStringWithFormat("Unknown protocol scheme \"%s\"",
92                                     res->scheme.str().c_str());
93    else
94      name = name.drop_front(res->scheme.size() + strlen("://"));
95  } else {
96    // Try to match socket name as $host:port - e.g., localhost:5555
97    if (!llvm::errorToBool(Socket::DecodeHostAndPort(name).takeError()))
98      socket_protocol = Socket::ProtocolTcp;
99  }
100
101  if (error.Fail())
102    return std::unique_ptr<Acceptor>();
103
104  std::unique_ptr<Socket> listener_socket_up =
105      Socket::Create(socket_protocol, child_processes_inherit, error);
106
107  LocalSocketIdFunc local_socket_id;
108  if (error.Success()) {
109    if (listener_socket_up->GetSocketProtocol() == Socket::ProtocolTcp) {
110      TCPSocket *tcp_socket =
111          static_cast<TCPSocket *>(listener_socket_up.get());
112      local_socket_id = [tcp_socket]() {
113        auto local_port = tcp_socket->GetLocalPortNumber();
114        return (local_port != 0) ? llvm::to_string(local_port) : "";
115      };
116    } else {
117      const std::string socket_name = std::string(name);
118      local_socket_id = [socket_name]() { return socket_name; };
119    }
120
121    return std::unique_ptr<Acceptor>(
122        new Acceptor(std::move(listener_socket_up), name, local_socket_id));
123  }
124
125  return std::unique_ptr<Acceptor>();
126}
127
128Acceptor::Acceptor(std::unique_ptr<Socket> &&listener_socket, StringRef name,
129                   const LocalSocketIdFunc &local_socket_id)
130    : m_listener_socket_up(std::move(listener_socket)), m_name(name.str()),
131      m_local_socket_id(local_socket_id) {}
132