1 //===-- Socket.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 #include "lldb/Host/Socket.h"
10 
11 #include "lldb/Host/Config.h"
12 #include "lldb/Host/Host.h"
13 #include "lldb/Host/SocketAddress.h"
14 #include "lldb/Host/common/TCPSocket.h"
15 #include "lldb/Host/common/UDPSocket.h"
16 #include "lldb/Utility/Log.h"
17 
18 #include "llvm/ADT/STLExtras.h"
19 #include "llvm/Support/Errno.h"
20 #include "llvm/Support/Error.h"
21 #include "llvm/Support/WindowsError.h"
22 
23 #if LLDB_ENABLE_POSIX
24 #include "lldb/Host/posix/DomainSocket.h"
25 
26 #include <arpa/inet.h>
27 #include <netdb.h>
28 #include <netinet/in.h>
29 #include <netinet/tcp.h>
30 #include <sys/socket.h>
31 #include <sys/un.h>
32 #include <unistd.h>
33 #endif
34 
35 #ifdef __linux__
36 #include "lldb/Host/linux/AbstractSocket.h"
37 #endif
38 
39 #ifdef __ANDROID__
40 #include <arpa/inet.h>
41 #include <asm-generic/errno-base.h>
42 #include <cerrno>
43 #include <fcntl.h>
44 #include <linux/tcp.h>
45 #include <sys/syscall.h>
46 #include <unistd.h>
47 #endif // __ANDROID__
48 
49 using namespace lldb;
50 using namespace lldb_private;
51 
52 #if defined(_WIN32)
53 typedef const char *set_socket_option_arg_type;
54 typedef char *get_socket_option_arg_type;
55 const NativeSocket Socket::kInvalidSocketValue = INVALID_SOCKET;
56 #else  // #if defined(_WIN32)
57 typedef const void *set_socket_option_arg_type;
58 typedef void *get_socket_option_arg_type;
59 const NativeSocket Socket::kInvalidSocketValue = -1;
60 #endif // #if defined(_WIN32)
61 
62 static bool IsInterrupted() {
63 #if defined(_WIN32)
64   return ::WSAGetLastError() == WSAEINTR;
65 #else
66   return errno == EINTR;
67 #endif
68 }
69 
70 Socket::Socket(SocketProtocol protocol, bool should_close,
71                bool child_processes_inherit)
72     : IOObject(eFDTypeSocket), m_protocol(protocol),
73       m_socket(kInvalidSocketValue),
74       m_child_processes_inherit(child_processes_inherit),
75       m_should_close_fd(should_close) {}
76 
77 Socket::~Socket() { Close(); }
78 
79 llvm::Error Socket::Initialize() {
80 #if defined(_WIN32)
81   auto wVersion = WINSOCK_VERSION;
82   WSADATA wsaData;
83   int err = ::WSAStartup(wVersion, &wsaData);
84   if (err == 0) {
85     if (wsaData.wVersion < wVersion) {
86       WSACleanup();
87       return llvm::make_error<llvm::StringError>(
88           "WSASock version is not expected.", llvm::inconvertibleErrorCode());
89     }
90   } else {
91     return llvm::errorCodeToError(llvm::mapWindowsError(::WSAGetLastError()));
92   }
93 #endif
94 
95   return llvm::Error::success();
96 }
97 
98 void Socket::Terminate() {
99 #if defined(_WIN32)
100   ::WSACleanup();
101 #endif
102 }
103 
104 std::unique_ptr<Socket> Socket::Create(const SocketProtocol protocol,
105                                        bool child_processes_inherit,
106                                        Status &error) {
107   error.Clear();
108 
109   std::unique_ptr<Socket> socket_up;
110   switch (protocol) {
111   case ProtocolTcp:
112     socket_up =
113         std::make_unique<TCPSocket>(true, child_processes_inherit);
114     break;
115   case ProtocolUdp:
116     socket_up =
117         std::make_unique<UDPSocket>(true, child_processes_inherit);
118     break;
119   case ProtocolUnixDomain:
120 #if LLDB_ENABLE_POSIX
121     socket_up =
122         std::make_unique<DomainSocket>(true, child_processes_inherit);
123 #else
124     error.SetErrorString(
125         "Unix domain sockets are not supported on this platform.");
126 #endif
127     break;
128   case ProtocolUnixAbstract:
129 #ifdef __linux__
130     socket_up =
131         std::make_unique<AbstractSocket>(child_processes_inherit);
132 #else
133     error.SetErrorString(
134         "Abstract domain sockets are not supported on this platform.");
135 #endif
136     break;
137   }
138 
139   if (error.Fail())
140     socket_up.reset();
141 
142   return socket_up;
143 }
144 
145 llvm::Expected<std::unique_ptr<Socket>>
146 Socket::TcpConnect(llvm::StringRef host_and_port,
147                    bool child_processes_inherit) {
148   Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_CONNECTION));
149   LLDB_LOG(log, "host_and_port = {0}", host_and_port);
150 
151   Status error;
152   std::unique_ptr<Socket> connect_socket(
153       Create(ProtocolTcp, child_processes_inherit, error));
154   if (error.Fail())
155     return error.ToError();
156 
157   error = connect_socket->Connect(host_and_port);
158   if (error.Success())
159     return std::move(connect_socket);
160 
161   return error.ToError();
162 }
163 
164 llvm::Expected<std::unique_ptr<TCPSocket>>
165 Socket::TcpListen(llvm::StringRef host_and_port, bool child_processes_inherit,
166                   int backlog) {
167   Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_CONNECTION));
168   LLDB_LOG(log, "host_and_port = {0}", host_and_port);
169 
170   std::unique_ptr<TCPSocket> listen_socket(
171       new TCPSocket(true, child_processes_inherit));
172 
173   Status error = listen_socket->Listen(host_and_port, backlog);
174   if (error.Fail())
175     return error.ToError();
176 
177   return std::move(listen_socket);
178 }
179 
180 llvm::Expected<std::unique_ptr<UDPSocket>>
181 Socket::UdpConnect(llvm::StringRef host_and_port,
182                    bool child_processes_inherit) {
183   return UDPSocket::Connect(host_and_port, child_processes_inherit);
184 }
185 
186 Status Socket::UnixDomainConnect(llvm::StringRef name,
187                                  bool child_processes_inherit,
188                                  Socket *&socket) {
189   Status error;
190   std::unique_ptr<Socket> connect_socket(
191       Create(ProtocolUnixDomain, child_processes_inherit, error));
192   if (error.Fail())
193     return error;
194 
195   error = connect_socket->Connect(name);
196   if (error.Success())
197     socket = connect_socket.release();
198 
199   return error;
200 }
201 
202 Status Socket::UnixDomainAccept(llvm::StringRef name,
203                                 bool child_processes_inherit, Socket *&socket) {
204   Status error;
205   std::unique_ptr<Socket> listen_socket(
206       Create(ProtocolUnixDomain, child_processes_inherit, error));
207   if (error.Fail())
208     return error;
209 
210   error = listen_socket->Listen(name, 5);
211   if (error.Fail())
212     return error;
213 
214   error = listen_socket->Accept(socket);
215   return error;
216 }
217 
218 Status Socket::UnixAbstractConnect(llvm::StringRef name,
219                                    bool child_processes_inherit,
220                                    Socket *&socket) {
221   Status error;
222   std::unique_ptr<Socket> connect_socket(
223       Create(ProtocolUnixAbstract, child_processes_inherit, error));
224   if (error.Fail())
225     return error;
226 
227   error = connect_socket->Connect(name);
228   if (error.Success())
229     socket = connect_socket.release();
230   return error;
231 }
232 
233 Status Socket::UnixAbstractAccept(llvm::StringRef name,
234                                   bool child_processes_inherit,
235                                   Socket *&socket) {
236   Status error;
237   std::unique_ptr<Socket> listen_socket(
238       Create(ProtocolUnixAbstract, child_processes_inherit, error));
239   if (error.Fail())
240     return error;
241 
242   error = listen_socket->Listen(name, 5);
243   if (error.Fail())
244     return error;
245 
246   error = listen_socket->Accept(socket);
247   return error;
248 }
249 
250 llvm::Expected<Socket::HostAndPort> Socket::DecodeHostAndPort(llvm::StringRef host_and_port) {
251   static llvm::Regex g_regex("([^:]+|\\[[0-9a-fA-F:]+.*\\]):([0-9]+)");
252   HostAndPort ret;
253   llvm::SmallVector<llvm::StringRef, 3> matches;
254   if (g_regex.match(host_and_port, &matches)) {
255     ret.hostname = matches[1].str();
256     // IPv6 addresses are wrapped in [] when specified with ports
257     if (ret.hostname.front() == '[' && ret.hostname.back() == ']')
258       ret.hostname = ret.hostname.substr(1, ret.hostname.size() - 2);
259     if (to_integer(matches[2], ret.port, 10))
260       return ret;
261   } else {
262     // If this was unsuccessful, then check if it's simply an unsigned 16-bit
263     // integer, representing a port with an empty host.
264     if (to_integer(host_and_port, ret.port, 10))
265       return ret;
266   }
267 
268   return llvm::createStringError(llvm::inconvertibleErrorCode(),
269                                  "invalid host:port specification: '%s'",
270                                  host_and_port.str().c_str());
271 }
272 
273 IOObject::WaitableHandle Socket::GetWaitableHandle() {
274   // TODO: On Windows, use WSAEventSelect
275   return m_socket;
276 }
277 
278 Status Socket::Read(void *buf, size_t &num_bytes) {
279   Status error;
280   int bytes_received = 0;
281   do {
282     bytes_received = ::recv(m_socket, static_cast<char *>(buf), num_bytes, 0);
283   } while (bytes_received < 0 && IsInterrupted());
284 
285   if (bytes_received < 0) {
286     SetLastError(error);
287     num_bytes = 0;
288   } else
289     num_bytes = bytes_received;
290 
291   Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_COMMUNICATION));
292   if (log) {
293     LLDB_LOGF(log,
294               "%p Socket::Read() (socket = %" PRIu64
295               ", src = %p, src_len = %" PRIu64 ", flags = 0) => %" PRIi64
296               " (error = %s)",
297               static_cast<void *>(this), static_cast<uint64_t>(m_socket), buf,
298               static_cast<uint64_t>(num_bytes),
299               static_cast<int64_t>(bytes_received), error.AsCString());
300   }
301 
302   return error;
303 }
304 
305 Status Socket::Write(const void *buf, size_t &num_bytes) {
306   const size_t src_len = num_bytes;
307   Status error;
308   int bytes_sent = 0;
309   do {
310     bytes_sent = Send(buf, num_bytes);
311   } while (bytes_sent < 0 && IsInterrupted());
312 
313   if (bytes_sent < 0) {
314     SetLastError(error);
315     num_bytes = 0;
316   } else
317     num_bytes = bytes_sent;
318 
319   Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_COMMUNICATION));
320   if (log) {
321     LLDB_LOGF(log,
322               "%p Socket::Write() (socket = %" PRIu64
323               ", src = %p, src_len = %" PRIu64 ", flags = 0) => %" PRIi64
324               " (error = %s)",
325               static_cast<void *>(this), static_cast<uint64_t>(m_socket), buf,
326               static_cast<uint64_t>(src_len),
327               static_cast<int64_t>(bytes_sent), error.AsCString());
328   }
329 
330   return error;
331 }
332 
333 Status Socket::PreDisconnect() {
334   Status error;
335   return error;
336 }
337 
338 Status Socket::Close() {
339   Status error;
340   if (!IsValid() || !m_should_close_fd)
341     return error;
342 
343   Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_CONNECTION));
344   LLDB_LOGF(log, "%p Socket::Close (fd = %" PRIu64 ")",
345             static_cast<void *>(this), static_cast<uint64_t>(m_socket));
346 
347 #if defined(_WIN32)
348   bool success = !!closesocket(m_socket);
349 #else
350   bool success = !!::close(m_socket);
351 #endif
352   // A reference to a FD was passed in, set it to an invalid value
353   m_socket = kInvalidSocketValue;
354   if (!success) {
355     SetLastError(error);
356   }
357 
358   return error;
359 }
360 
361 int Socket::GetOption(int level, int option_name, int &option_value) {
362   get_socket_option_arg_type option_value_p =
363       reinterpret_cast<get_socket_option_arg_type>(&option_value);
364   socklen_t option_value_size = sizeof(int);
365   return ::getsockopt(m_socket, level, option_name, option_value_p,
366                       &option_value_size);
367 }
368 
369 int Socket::SetOption(int level, int option_name, int option_value) {
370   set_socket_option_arg_type option_value_p =
371       reinterpret_cast<get_socket_option_arg_type>(&option_value);
372   return ::setsockopt(m_socket, level, option_name, option_value_p,
373                       sizeof(option_value));
374 }
375 
376 size_t Socket::Send(const void *buf, const size_t num_bytes) {
377   return ::send(m_socket, static_cast<const char *>(buf), num_bytes, 0);
378 }
379 
380 void Socket::SetLastError(Status &error) {
381 #if defined(_WIN32)
382   error.SetError(::WSAGetLastError(), lldb::eErrorTypeWin32);
383 #else
384   error.SetErrorToErrno();
385 #endif
386 }
387 
388 NativeSocket Socket::CreateSocket(const int domain, const int type,
389                                   const int protocol,
390                                   bool child_processes_inherit, Status &error) {
391   error.Clear();
392   auto socket_type = type;
393 #ifdef SOCK_CLOEXEC
394   if (!child_processes_inherit)
395     socket_type |= SOCK_CLOEXEC;
396 #endif
397   auto sock = ::socket(domain, socket_type, protocol);
398   if (sock == kInvalidSocketValue)
399     SetLastError(error);
400 
401   return sock;
402 }
403 
404 NativeSocket Socket::AcceptSocket(NativeSocket sockfd, struct sockaddr *addr,
405                                   socklen_t *addrlen,
406                                   bool child_processes_inherit, Status &error) {
407   error.Clear();
408 #if defined(ANDROID_USE_ACCEPT_WORKAROUND)
409   // Hack:
410   // This enables static linking lldb-server to an API 21 libc, but still
411   // having it run on older devices. It is necessary because API 21 libc's
412   // implementation of accept() uses the accept4 syscall(), which is not
413   // available in older kernels. Using an older libc would fix this issue, but
414   // introduce other ones, as the old libraries were quite buggy.
415   int fd = syscall(__NR_accept, sockfd, addr, addrlen);
416   if (fd >= 0 && !child_processes_inherit) {
417     int flags = ::fcntl(fd, F_GETFD);
418     if (flags != -1 && ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC) != -1)
419       return fd;
420     SetLastError(error);
421     close(fd);
422   }
423   return fd;
424 #elif defined(SOCK_CLOEXEC) && defined(HAVE_ACCEPT4)
425   int flags = 0;
426   if (!child_processes_inherit) {
427     flags |= SOCK_CLOEXEC;
428   }
429   NativeSocket fd = llvm::sys::RetryAfterSignal(
430       static_cast<NativeSocket>(-1), ::accept4, sockfd, addr, addrlen, flags);
431 #else
432   NativeSocket fd = llvm::sys::RetryAfterSignal(
433       static_cast<NativeSocket>(-1), ::accept, sockfd, addr, addrlen);
434 #endif
435   if (fd == kInvalidSocketValue)
436     SetLastError(error);
437   return fd;
438 }
439 
440 llvm::raw_ostream &lldb_private::operator<<(llvm::raw_ostream &OS,
441                                             const Socket::HostAndPort &HP) {
442   return OS << '[' << HP.hostname << ']' << ':' << HP.port;
443 }
444