1 //===-- TCPSocket.cpp -----------------------------------------------------===//
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 #if defined(_MSC_VER)
10 #define _WINSOCK_DEPRECATED_NO_WARNINGS
11 #endif
12 
13 #include "lldb/Host/common/TCPSocket.h"
14 
15 #include "lldb/Host/Config.h"
16 #include "lldb/Host/MainLoop.h"
17 #include "lldb/Utility/LLDBLog.h"
18 #include "lldb/Utility/Log.h"
19 
20 #include "llvm/Config/llvm-config.h"
21 #include "llvm/Support/Errno.h"
22 #include "llvm/Support/WindowsError.h"
23 #include "llvm/Support/raw_ostream.h"
24 
25 #if LLDB_ENABLE_POSIX
26 #include <arpa/inet.h>
27 #include <netinet/tcp.h>
28 #include <sys/socket.h>
29 #endif
30 
31 #if defined(_WIN32)
32 #include <winsock2.h>
33 #endif
34 
35 #ifdef _WIN32
36 #define CLOSE_SOCKET closesocket
37 typedef const char *set_socket_option_arg_type;
38 #else
39 #include <unistd.h>
40 #define CLOSE_SOCKET ::close
41 typedef const void *set_socket_option_arg_type;
42 #endif
43 
44 using namespace lldb;
45 using namespace lldb_private;
46 
47 static Status GetLastSocketError() {
48   std::error_code EC;
49 #ifdef _WIN32
50   EC = llvm::mapWindowsError(WSAGetLastError());
51 #else
52   EC = std::error_code(errno, std::generic_category());
53 #endif
54   return EC;
55 }
56 
57 static const int kType = SOCK_STREAM;
58 
59 TCPSocket::TCPSocket(bool should_close, bool child_processes_inherit)
60     : Socket(ProtocolTcp, should_close, child_processes_inherit) {}
61 
62 TCPSocket::TCPSocket(NativeSocket socket, const TCPSocket &listen_socket)
63     : Socket(ProtocolTcp, listen_socket.m_should_close_fd,
64              listen_socket.m_child_processes_inherit) {
65   m_socket = socket;
66 }
67 
68 TCPSocket::TCPSocket(NativeSocket socket, bool should_close,
69                      bool child_processes_inherit)
70     : Socket(ProtocolTcp, should_close, child_processes_inherit) {
71   m_socket = socket;
72 }
73 
74 TCPSocket::~TCPSocket() { CloseListenSockets(); }
75 
76 bool TCPSocket::IsValid() const {
77   return m_socket != kInvalidSocketValue || m_listen_sockets.size() != 0;
78 }
79 
80 // Return the port number that is being used by the socket.
81 uint16_t TCPSocket::GetLocalPortNumber() const {
82   if (m_socket != kInvalidSocketValue) {
83     SocketAddress sock_addr;
84     socklen_t sock_addr_len = sock_addr.GetMaxLength();
85     if (::getsockname(m_socket, sock_addr, &sock_addr_len) == 0)
86       return sock_addr.GetPort();
87   } else if (!m_listen_sockets.empty()) {
88     SocketAddress sock_addr;
89     socklen_t sock_addr_len = sock_addr.GetMaxLength();
90     if (::getsockname(m_listen_sockets.begin()->first, sock_addr,
91                       &sock_addr_len) == 0)
92       return sock_addr.GetPort();
93   }
94   return 0;
95 }
96 
97 std::string TCPSocket::GetLocalIPAddress() const {
98   // We bound to port zero, so we need to figure out which port we actually
99   // bound to
100   if (m_socket != kInvalidSocketValue) {
101     SocketAddress sock_addr;
102     socklen_t sock_addr_len = sock_addr.GetMaxLength();
103     if (::getsockname(m_socket, sock_addr, &sock_addr_len) == 0)
104       return sock_addr.GetIPAddress();
105   }
106   return "";
107 }
108 
109 uint16_t TCPSocket::GetRemotePortNumber() const {
110   if (m_socket != kInvalidSocketValue) {
111     SocketAddress sock_addr;
112     socklen_t sock_addr_len = sock_addr.GetMaxLength();
113     if (::getpeername(m_socket, sock_addr, &sock_addr_len) == 0)
114       return sock_addr.GetPort();
115   }
116   return 0;
117 }
118 
119 std::string TCPSocket::GetRemoteIPAddress() const {
120   // We bound to port zero, so we need to figure out which port we actually
121   // bound to
122   if (m_socket != kInvalidSocketValue) {
123     SocketAddress sock_addr;
124     socklen_t sock_addr_len = sock_addr.GetMaxLength();
125     if (::getpeername(m_socket, sock_addr, &sock_addr_len) == 0)
126       return sock_addr.GetIPAddress();
127   }
128   return "";
129 }
130 
131 std::string TCPSocket::GetRemoteConnectionURI() const {
132   if (m_socket != kInvalidSocketValue) {
133     return std::string(llvm::formatv(
134         "connect://[{0}]:{1}", GetRemoteIPAddress(), GetRemotePortNumber()));
135   }
136   return "";
137 }
138 
139 Status TCPSocket::CreateSocket(int domain) {
140   Status error;
141   if (IsValid())
142     error = Close();
143   if (error.Fail())
144     return error;
145   m_socket = Socket::CreateSocket(domain, kType, IPPROTO_TCP,
146                                   m_child_processes_inherit, error);
147   return error;
148 }
149 
150 Status TCPSocket::Connect(llvm::StringRef name) {
151 
152   Log *log = GetLog(LLDBLog::Communication);
153   LLDB_LOGF(log, "TCPSocket::%s (host/port = %s)", __FUNCTION__, name.data());
154 
155   Status error;
156   llvm::Expected<HostAndPort> host_port = DecodeHostAndPort(name);
157   if (!host_port)
158     return Status(host_port.takeError());
159 
160   std::vector<SocketAddress> addresses =
161       SocketAddress::GetAddressInfo(host_port->hostname.c_str(), nullptr,
162                                     AF_UNSPEC, SOCK_STREAM, IPPROTO_TCP);
163   for (SocketAddress &address : addresses) {
164     error = CreateSocket(address.GetFamily());
165     if (error.Fail())
166       continue;
167 
168     address.SetPort(host_port->port);
169 
170     if (-1 == llvm::sys::RetryAfterSignal(-1, ::connect, GetNativeSocket(),
171                                           &address.sockaddr(),
172                                           address.GetLength())) {
173       Close();
174       continue;
175     }
176 
177     SetOptionNoDelay();
178 
179     error.Clear();
180     return error;
181   }
182 
183   error.SetErrorString("Failed to connect port");
184   return error;
185 }
186 
187 Status TCPSocket::Listen(llvm::StringRef name, int backlog) {
188   Log *log = GetLog(LLDBLog::Connection);
189   LLDB_LOGF(log, "TCPSocket::%s (%s)", __FUNCTION__, name.data());
190 
191   Status error;
192   llvm::Expected<HostAndPort> host_port = DecodeHostAndPort(name);
193   if (!host_port)
194     return Status(host_port.takeError());
195 
196   if (host_port->hostname == "*")
197     host_port->hostname = "0.0.0.0";
198   std::vector<SocketAddress> addresses = SocketAddress::GetAddressInfo(
199       host_port->hostname.c_str(), nullptr, AF_UNSPEC, SOCK_STREAM, IPPROTO_TCP);
200   for (SocketAddress &address : addresses) {
201     int fd = Socket::CreateSocket(address.GetFamily(), kType, IPPROTO_TCP,
202                                   m_child_processes_inherit, error);
203     if (error.Fail())
204       continue;
205 
206     // enable local address reuse
207     int option_value = 1;
208     set_socket_option_arg_type option_value_p =
209         reinterpret_cast<set_socket_option_arg_type>(&option_value);
210     ::setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, option_value_p,
211                  sizeof(option_value));
212 
213     SocketAddress listen_address = address;
214     if(!listen_address.IsLocalhost())
215       listen_address.SetToAnyAddress(address.GetFamily(), host_port->port);
216     else
217       listen_address.SetPort(host_port->port);
218 
219     int err =
220         ::bind(fd, &listen_address.sockaddr(), listen_address.GetLength());
221     if (-1 != err)
222       err = ::listen(fd, backlog);
223 
224     if (-1 == err) {
225       error = GetLastSocketError();
226       CLOSE_SOCKET(fd);
227       continue;
228     }
229 
230     if (host_port->port == 0) {
231       socklen_t sa_len = address.GetLength();
232       if (getsockname(fd, &address.sockaddr(), &sa_len) == 0)
233         host_port->port = address.GetPort();
234     }
235     m_listen_sockets[fd] = address;
236   }
237 
238   if (m_listen_sockets.empty()) {
239     assert(error.Fail());
240     return error;
241   }
242   return Status();
243 }
244 
245 void TCPSocket::CloseListenSockets() {
246   for (auto socket : m_listen_sockets)
247     CLOSE_SOCKET(socket.first);
248   m_listen_sockets.clear();
249 }
250 
251 Status TCPSocket::Accept(Socket *&conn_socket) {
252   Status error;
253   if (m_listen_sockets.size() == 0) {
254     error.SetErrorString("No open listening sockets!");
255     return error;
256   }
257 
258   int sock = -1;
259   int listen_sock = -1;
260   lldb_private::SocketAddress AcceptAddr;
261   MainLoop accept_loop;
262   std::vector<MainLoopBase::ReadHandleUP> handles;
263   for (auto socket : m_listen_sockets) {
264     auto fd = socket.first;
265     auto inherit = this->m_child_processes_inherit;
266     auto io_sp = IOObjectSP(new TCPSocket(socket.first, false, inherit));
267     handles.emplace_back(accept_loop.RegisterReadObject(
268         io_sp, [fd, inherit, &sock, &AcceptAddr, &error,
269                         &listen_sock](MainLoopBase &loop) {
270           socklen_t sa_len = AcceptAddr.GetMaxLength();
271           sock = AcceptSocket(fd, &AcceptAddr.sockaddr(), &sa_len, inherit,
272                               error);
273           listen_sock = fd;
274           loop.RequestTermination();
275         }, error));
276     if (error.Fail())
277       return error;
278   }
279 
280   bool accept_connection = false;
281   std::unique_ptr<TCPSocket> accepted_socket;
282   // Loop until we are happy with our connection
283   while (!accept_connection) {
284     accept_loop.Run();
285 
286     if (error.Fail())
287         return error;
288 
289     lldb_private::SocketAddress &AddrIn = m_listen_sockets[listen_sock];
290     if (!AddrIn.IsAnyAddr() && AcceptAddr != AddrIn) {
291       CLOSE_SOCKET(sock);
292       llvm::errs() << llvm::formatv(
293           "error: rejecting incoming connection from {0} (expecting {1})",
294           AcceptAddr.GetIPAddress(), AddrIn.GetIPAddress());
295       continue;
296     }
297     accept_connection = true;
298     accepted_socket.reset(new TCPSocket(sock, *this));
299   }
300 
301   if (!accepted_socket)
302     return error;
303 
304   // Keep our TCP packets coming without any delays.
305   accepted_socket->SetOptionNoDelay();
306   error.Clear();
307   conn_socket = accepted_socket.release();
308   return error;
309 }
310 
311 int TCPSocket::SetOptionNoDelay() {
312   return SetOption(IPPROTO_TCP, TCP_NODELAY, 1);
313 }
314 
315 int TCPSocket::SetOptionReuseAddress() {
316   return SetOption(SOL_SOCKET, SO_REUSEADDR, 1);
317 }
318