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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/Log.h"
18 
19 #include "llvm/Config/llvm-config.h"
20 #include "llvm/Support/Errno.h"
21 #include "llvm/Support/WindowsError.h"
22 #include "llvm/Support/raw_ostream.h"
23 
24 #if LLDB_ENABLE_POSIX
25 #include <arpa/inet.h>
26 #include <netinet/tcp.h>
27 #include <sys/socket.h>
28 #endif
29 
30 #if defined(_WIN32)
31 #include <winsock2.h>
32 #endif
33 
34 #ifdef _WIN32
35 #define CLOSE_SOCKET closesocket
36 typedef const char *set_socket_option_arg_type;
37 #else
38 #include <unistd.h>
39 #define CLOSE_SOCKET ::close
40 typedef const void *set_socket_option_arg_type;
41 #endif
42 
43 using namespace lldb;
44 using namespace lldb_private;
45 
GetLastSocketError()46 static Status GetLastSocketError() {
47   std::error_code EC;
48 #ifdef _WIN32
49   EC = llvm::mapWindowsError(WSAGetLastError());
50 #else
51   EC = std::error_code(errno, std::generic_category());
52 #endif
53   return EC;
54 }
55 
56 namespace {
57 const int kType = SOCK_STREAM;
58 }
59 
TCPSocket(bool should_close,bool child_processes_inherit)60 TCPSocket::TCPSocket(bool should_close, bool child_processes_inherit)
61     : Socket(ProtocolTcp, should_close, child_processes_inherit) {}
62 
TCPSocket(NativeSocket socket,const TCPSocket & listen_socket)63 TCPSocket::TCPSocket(NativeSocket socket, const TCPSocket &listen_socket)
64     : Socket(ProtocolTcp, listen_socket.m_should_close_fd,
65              listen_socket.m_child_processes_inherit) {
66   m_socket = socket;
67 }
68 
TCPSocket(NativeSocket socket,bool should_close,bool child_processes_inherit)69 TCPSocket::TCPSocket(NativeSocket socket, bool should_close,
70                      bool child_processes_inherit)
71     : Socket(ProtocolTcp, should_close, child_processes_inherit) {
72   m_socket = socket;
73 }
74 
~TCPSocket()75 TCPSocket::~TCPSocket() { CloseListenSockets(); }
76 
IsValid() const77 bool TCPSocket::IsValid() const {
78   return m_socket != kInvalidSocketValue || m_listen_sockets.size() != 0;
79 }
80 
81 // Return the port number that is being used by the socket.
GetLocalPortNumber() const82 uint16_t TCPSocket::GetLocalPortNumber() const {
83   if (m_socket != kInvalidSocketValue) {
84     SocketAddress sock_addr;
85     socklen_t sock_addr_len = sock_addr.GetMaxLength();
86     if (::getsockname(m_socket, sock_addr, &sock_addr_len) == 0)
87       return sock_addr.GetPort();
88   } else if (!m_listen_sockets.empty()) {
89     SocketAddress sock_addr;
90     socklen_t sock_addr_len = sock_addr.GetMaxLength();
91     if (::getsockname(m_listen_sockets.begin()->first, sock_addr,
92                       &sock_addr_len) == 0)
93       return sock_addr.GetPort();
94   }
95   return 0;
96 }
97 
GetLocalIPAddress() const98 std::string TCPSocket::GetLocalIPAddress() const {
99   // We bound to port zero, so we need to figure out which port we actually
100   // bound to
101   if (m_socket != kInvalidSocketValue) {
102     SocketAddress sock_addr;
103     socklen_t sock_addr_len = sock_addr.GetMaxLength();
104     if (::getsockname(m_socket, sock_addr, &sock_addr_len) == 0)
105       return sock_addr.GetIPAddress();
106   }
107   return "";
108 }
109 
GetRemotePortNumber() const110 uint16_t TCPSocket::GetRemotePortNumber() const {
111   if (m_socket != kInvalidSocketValue) {
112     SocketAddress sock_addr;
113     socklen_t sock_addr_len = sock_addr.GetMaxLength();
114     if (::getpeername(m_socket, sock_addr, &sock_addr_len) == 0)
115       return sock_addr.GetPort();
116   }
117   return 0;
118 }
119 
GetRemoteIPAddress() const120 std::string TCPSocket::GetRemoteIPAddress() const {
121   // We bound to port zero, so we need to figure out which port we actually
122   // bound to
123   if (m_socket != kInvalidSocketValue) {
124     SocketAddress sock_addr;
125     socklen_t sock_addr_len = sock_addr.GetMaxLength();
126     if (::getpeername(m_socket, sock_addr, &sock_addr_len) == 0)
127       return sock_addr.GetIPAddress();
128   }
129   return "";
130 }
131 
GetRemoteConnectionURI() const132 std::string TCPSocket::GetRemoteConnectionURI() const {
133   if (m_socket != kInvalidSocketValue) {
134     return std::string(llvm::formatv(
135         "connect://[{0}]:{1}", GetRemoteIPAddress(), GetRemotePortNumber()));
136   }
137   return "";
138 }
139 
CreateSocket(int domain)140 Status TCPSocket::CreateSocket(int domain) {
141   Status error;
142   if (IsValid())
143     error = Close();
144   if (error.Fail())
145     return error;
146   m_socket = Socket::CreateSocket(domain, kType, IPPROTO_TCP,
147                                   m_child_processes_inherit, error);
148   return error;
149 }
150 
Connect(llvm::StringRef name)151 Status TCPSocket::Connect(llvm::StringRef name) {
152 
153   Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_COMMUNICATION));
154   LLDB_LOGF(log, "TCPSocket::%s (host/port = %s)", __FUNCTION__, name.data());
155 
156   Status error;
157   std::string host_str;
158   std::string port_str;
159   int32_t port = INT32_MIN;
160   if (!DecodeHostAndPort(name, host_str, port_str, port, &error))
161     return error;
162 
163   std::vector<SocketAddress> addresses = SocketAddress::GetAddressInfo(
164       host_str.c_str(), nullptr, AF_UNSPEC, SOCK_STREAM, IPPROTO_TCP);
165   for (SocketAddress &address : addresses) {
166     error = CreateSocket(address.GetFamily());
167     if (error.Fail())
168       continue;
169 
170     address.SetPort(port);
171 
172     if (-1 == llvm::sys::RetryAfterSignal(-1, ::connect,
173           GetNativeSocket(), &address.sockaddr(), address.GetLength())) {
174       CLOSE_SOCKET(GetNativeSocket());
175       continue;
176     }
177 
178     SetOptionNoDelay();
179 
180     error.Clear();
181     return error;
182   }
183 
184   error.SetErrorString("Failed to connect port");
185   return error;
186 }
187 
Listen(llvm::StringRef name,int backlog)188 Status TCPSocket::Listen(llvm::StringRef name, int backlog) {
189   Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_CONNECTION));
190   LLDB_LOGF(log, "TCPSocket::%s (%s)", __FUNCTION__, name.data());
191 
192   Status error;
193   std::string host_str;
194   std::string port_str;
195   int32_t port = INT32_MIN;
196   if (!DecodeHostAndPort(name, host_str, port_str, port, &error))
197     return error;
198 
199   if (host_str == "*")
200     host_str = "0.0.0.0";
201   std::vector<SocketAddress> addresses = SocketAddress::GetAddressInfo(
202       host_str.c_str(), nullptr, AF_UNSPEC, SOCK_STREAM, IPPROTO_TCP);
203   for (SocketAddress &address : addresses) {
204     int fd = Socket::CreateSocket(address.GetFamily(), kType, IPPROTO_TCP,
205                                   m_child_processes_inherit, error);
206     if (error.Fail())
207       continue;
208 
209     // enable local address reuse
210     int option_value = 1;
211     set_socket_option_arg_type option_value_p =
212         reinterpret_cast<set_socket_option_arg_type>(&option_value);
213     ::setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, option_value_p,
214                  sizeof(option_value));
215 
216     SocketAddress listen_address = address;
217     if(!listen_address.IsLocalhost())
218       listen_address.SetToAnyAddress(address.GetFamily(), port);
219     else
220       listen_address.SetPort(port);
221 
222     int err =
223         ::bind(fd, &listen_address.sockaddr(), listen_address.GetLength());
224     if (-1 != err)
225       err = ::listen(fd, backlog);
226 
227     if (-1 == err) {
228       error = GetLastSocketError();
229       CLOSE_SOCKET(fd);
230       continue;
231     }
232 
233     if (port == 0) {
234       socklen_t sa_len = address.GetLength();
235       if (getsockname(fd, &address.sockaddr(), &sa_len) == 0)
236         port = address.GetPort();
237     }
238     m_listen_sockets[fd] = address;
239   }
240 
241   if (m_listen_sockets.empty()) {
242     assert(error.Fail());
243     return error;
244   }
245   return Status();
246 }
247 
CloseListenSockets()248 void TCPSocket::CloseListenSockets() {
249   for (auto socket : m_listen_sockets)
250     CLOSE_SOCKET(socket.first);
251   m_listen_sockets.clear();
252 }
253 
Accept(Socket * & conn_socket)254 Status TCPSocket::Accept(Socket *&conn_socket) {
255   Status error;
256   if (m_listen_sockets.size() == 0) {
257     error.SetErrorString("No open listening sockets!");
258     return error;
259   }
260 
261   int sock = -1;
262   int listen_sock = -1;
263   lldb_private::SocketAddress AcceptAddr;
264   MainLoop accept_loop;
265   std::vector<MainLoopBase::ReadHandleUP> handles;
266   for (auto socket : m_listen_sockets) {
267     auto fd = socket.first;
268     auto inherit = this->m_child_processes_inherit;
269     auto io_sp = IOObjectSP(new TCPSocket(socket.first, false, inherit));
270     handles.emplace_back(accept_loop.RegisterReadObject(
271         io_sp, [fd, inherit, &sock, &AcceptAddr, &error,
272                         &listen_sock](MainLoopBase &loop) {
273           socklen_t sa_len = AcceptAddr.GetMaxLength();
274           sock = AcceptSocket(fd, &AcceptAddr.sockaddr(), &sa_len, inherit,
275                               error);
276           listen_sock = fd;
277           loop.RequestTermination();
278         }, error));
279     if (error.Fail())
280       return error;
281   }
282 
283   bool accept_connection = false;
284   std::unique_ptr<TCPSocket> accepted_socket;
285   // Loop until we are happy with our connection
286   while (!accept_connection) {
287     accept_loop.Run();
288 
289     if (error.Fail())
290         return error;
291 
292     lldb_private::SocketAddress &AddrIn = m_listen_sockets[listen_sock];
293     if (!AddrIn.IsAnyAddr() && AcceptAddr != AddrIn) {
294       CLOSE_SOCKET(sock);
295       llvm::errs() << llvm::formatv(
296           "error: rejecting incoming connection from {0} (expecting {1})",
297           AcceptAddr.GetIPAddress(), AddrIn.GetIPAddress());
298       continue;
299     }
300     accept_connection = true;
301     accepted_socket.reset(new TCPSocket(sock, *this));
302   }
303 
304   if (!accepted_socket)
305     return error;
306 
307   // Keep our TCP packets coming without any delays.
308   accepted_socket->SetOptionNoDelay();
309   error.Clear();
310   conn_socket = accepted_socket.release();
311   return error;
312 }
313 
SetOptionNoDelay()314 int TCPSocket::SetOptionNoDelay() {
315   return SetOption(IPPROTO_TCP, TCP_NODELAY, 1);
316 }
317 
SetOptionReuseAddress()318 int TCPSocket::SetOptionReuseAddress() {
319   return SetOption(SOL_SOCKET, SO_REUSEADDR, 1);
320 }
321