1 //===-- Socket.cpp ----------------------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "lldb/Host/Socket.h"
11 
12 #include "lldb/Host/Config.h"
13 #include "lldb/Host/Host.h"
14 #include "lldb/Host/SocketAddress.h"
15 #include "lldb/Host/StringConvert.h"
16 #include "lldb/Host/common/TCPSocket.h"
17 #include "lldb/Host/common/UDPSocket.h"
18 #include "lldb/Utility/Log.h"
19 #include "lldb/Utility/RegularExpression.h"
20 
21 #include "llvm/ADT/STLExtras.h"
22 
23 #ifndef LLDB_DISABLE_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 #endif
33 
34 #ifdef __linux__
35 #include "lldb/Host/linux/AbstractSocket.h"
36 #endif
37 
38 #ifdef __ANDROID__
39 #include <arpa/inet.h>
40 #include <asm-generic/errno-base.h>
41 #include <errno.h>
42 #include <linux/tcp.h>
43 #include <fcntl.h>
44 #include <sys/syscall.h>
45 #include <unistd.h>
46 #endif // __ANDROID__
47 
48 using namespace lldb;
49 using namespace lldb_private;
50 
51 #if defined(_WIN32)
52 typedef const char *set_socket_option_arg_type;
53 typedef char *get_socket_option_arg_type;
54 const NativeSocket Socket::kInvalidSocketValue = INVALID_SOCKET;
55 #else  // #if defined(_WIN32)
56 typedef const void *set_socket_option_arg_type;
57 typedef void *get_socket_option_arg_type;
58 const NativeSocket Socket::kInvalidSocketValue = -1;
59 #endif // #if defined(_WIN32)
60 
61 namespace {
62 
63 bool IsInterrupted() {
64 #if defined(_WIN32)
65   return ::WSAGetLastError() == WSAEINTR;
66 #else
67   return errno == EINTR;
68 #endif
69 }
70 }
71 
72 Socket::Socket(SocketProtocol protocol, bool should_close,
73                bool child_processes_inherit)
74     : IOObject(eFDTypeSocket, should_close), m_protocol(protocol),
75       m_socket(kInvalidSocketValue),
76       m_child_processes_inherit(child_processes_inherit) {}
77 
78 Socket::~Socket() { Close(); }
79 
80 std::unique_ptr<Socket> Socket::Create(const SocketProtocol protocol,
81                                        bool child_processes_inherit,
82                                        Error &error) {
83   error.Clear();
84 
85   std::unique_ptr<Socket> socket_up;
86   switch (protocol) {
87   case ProtocolTcp:
88     socket_up = llvm::make_unique<TCPSocket>(true, child_processes_inherit);
89     break;
90   case ProtocolUdp:
91     socket_up = llvm::make_unique<UDPSocket>(true, child_processes_inherit);
92     break;
93   case ProtocolUnixDomain:
94 #ifndef LLDB_DISABLE_POSIX
95     socket_up = llvm::make_unique<DomainSocket>(true, child_processes_inherit);
96 #else
97     error.SetErrorString(
98         "Unix domain sockets are not supported on this platform.");
99 #endif
100     break;
101   case ProtocolUnixAbstract:
102 #ifdef __linux__
103     socket_up =
104         llvm::make_unique<AbstractSocket>(child_processes_inherit);
105 #else
106     error.SetErrorString(
107         "Abstract domain sockets are not supported on this platform.");
108 #endif
109     break;
110   }
111 
112   if (error.Fail())
113     socket_up.reset();
114 
115   return socket_up;
116 }
117 
118 Error Socket::TcpConnect(llvm::StringRef host_and_port,
119                          bool child_processes_inherit, Socket *&socket) {
120   Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_COMMUNICATION));
121   if (log)
122     log->Printf("Socket::%s (host/port = %s)", __FUNCTION__,
123                 host_and_port.data());
124 
125   Error error;
126   std::unique_ptr<Socket> connect_socket(
127       Create(ProtocolTcp, child_processes_inherit, error));
128   if (error.Fail())
129     return error;
130 
131   error = connect_socket->Connect(host_and_port);
132   if (error.Success())
133     socket = connect_socket.release();
134 
135   return error;
136 }
137 
138 Error Socket::TcpListen(llvm::StringRef host_and_port,
139                         bool child_processes_inherit, Socket *&socket,
140                         Predicate<uint16_t> *predicate, int backlog) {
141   Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_CONNECTION));
142   if (log)
143     log->Printf("Socket::%s (%s)", __FUNCTION__, host_and_port.data());
144 
145   Error error;
146   std::string host_str;
147   std::string port_str;
148   int32_t port = INT32_MIN;
149   if (!DecodeHostAndPort(host_and_port, host_str, port_str, port, &error))
150     return error;
151 
152   std::unique_ptr<TCPSocket> listen_socket(
153       new TCPSocket(child_processes_inherit, true));
154   if (error.Fail())
155     return error;
156 
157   error = listen_socket->Listen(host_and_port, backlog);
158   if (error.Success()) {
159     // We were asked to listen on port zero which means we
160     // must now read the actual port that was given to us
161     // as port zero is a special code for "find an open port
162     // for me".
163     if (port == 0)
164       port = listen_socket->GetLocalPortNumber();
165 
166     // Set the port predicate since when doing a listen://<host>:<port>
167     // it often needs to accept the incoming connection which is a blocking
168     // system call. Allowing access to the bound port using a predicate allows
169     // us to wait for the port predicate to be set to a non-zero value from
170     // another thread in an efficient manor.
171     if (predicate)
172       predicate->SetValue(port, eBroadcastAlways);
173     socket = listen_socket.release();
174   }
175 
176   return error;
177 }
178 
179 Error Socket::UdpConnect(llvm::StringRef host_and_port,
180                          bool child_processes_inherit, Socket *&socket) {
181   Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_CONNECTION));
182   if (log)
183     log->Printf("Socket::%s (host/port = %s)", __FUNCTION__,
184                 host_and_port.data());
185 
186   return UDPSocket::Connect(host_and_port, child_processes_inherit, socket);
187 }
188 
189 Error Socket::UnixDomainConnect(llvm::StringRef name,
190                                 bool child_processes_inherit, Socket *&socket) {
191   Error error;
192   std::unique_ptr<Socket> connect_socket(
193       Create(ProtocolUnixDomain, child_processes_inherit, error));
194   if (error.Fail())
195     return error;
196 
197   error = connect_socket->Connect(name);
198   if (error.Success())
199     socket = connect_socket.release();
200 
201   return error;
202 }
203 
204 Error Socket::UnixDomainAccept(llvm::StringRef name,
205                                bool child_processes_inherit, Socket *&socket) {
206   Error error;
207   std::unique_ptr<Socket> listen_socket(
208       Create(ProtocolUnixDomain, child_processes_inherit, error));
209   if (error.Fail())
210     return error;
211 
212   error = listen_socket->Listen(name, 5);
213   if (error.Fail())
214     return error;
215 
216   error = listen_socket->Accept(socket);
217   return error;
218 }
219 
220 Error Socket::UnixAbstractConnect(llvm::StringRef name,
221                                   bool child_processes_inherit,
222                                   Socket *&socket) {
223   Error error;
224   std::unique_ptr<Socket> connect_socket(
225       Create(ProtocolUnixAbstract, child_processes_inherit, error));
226   if (error.Fail())
227     return error;
228 
229   error = connect_socket->Connect(name);
230   if (error.Success())
231     socket = connect_socket.release();
232   return error;
233 }
234 
235 Error Socket::UnixAbstractAccept(llvm::StringRef name,
236                                  bool child_processes_inherit,
237                                  Socket *&socket) {
238   Error error;
239   std::unique_ptr<Socket> listen_socket(
240       Create(ProtocolUnixAbstract, child_processes_inherit, error));
241   if (error.Fail())
242     return error;
243 
244   error = listen_socket->Listen(name, 5);
245   if (error.Fail())
246     return error;
247 
248   error = listen_socket->Accept(socket);
249   return error;
250 }
251 
252 bool Socket::DecodeHostAndPort(llvm::StringRef host_and_port,
253                                std::string &host_str, std::string &port_str,
254                                int32_t &port, Error *error_ptr) {
255   static RegularExpression g_regex(
256       llvm::StringRef("([^:]+|\\[[0-9a-fA-F:]+.*\\]):([0-9]+)"));
257   RegularExpression::Match regex_match(2);
258   if (g_regex.Execute(host_and_port, &regex_match)) {
259     if (regex_match.GetMatchAtIndex(host_and_port.data(), 1, host_str) &&
260         regex_match.GetMatchAtIndex(host_and_port.data(), 2, port_str)) {
261       // IPv6 addresses are wrapped in [] when specified with ports
262       if (host_str.front() == '[' && host_str.back() == ']')
263         host_str = host_str.substr(1, host_str.size() - 2);
264       bool ok = false;
265       port = StringConvert::ToUInt32(port_str.c_str(), UINT32_MAX, 10, &ok);
266       if (ok && port <= UINT16_MAX) {
267         if (error_ptr)
268           error_ptr->Clear();
269         return true;
270       }
271       // port is too large
272       if (error_ptr)
273         error_ptr->SetErrorStringWithFormat(
274             "invalid host:port specification: '%s'", host_and_port.data());
275       return false;
276     }
277   }
278 
279   // If this was unsuccessful, then check if it's simply a signed 32-bit
280   // integer, representing
281   // a port with an empty host.
282   host_str.clear();
283   port_str.clear();
284   bool ok = false;
285   port = StringConvert::ToUInt32(host_and_port.data(), UINT32_MAX, 10, &ok);
286   if (ok && port < UINT16_MAX) {
287     port_str = host_and_port;
288     if (error_ptr)
289       error_ptr->Clear();
290     return true;
291   }
292 
293   if (error_ptr)
294     error_ptr->SetErrorStringWithFormat("invalid host:port specification: '%s'",
295                                         host_and_port.data());
296   return false;
297 }
298 
299 IOObject::WaitableHandle Socket::GetWaitableHandle() {
300   // TODO: On Windows, use WSAEventSelect
301   return m_socket;
302 }
303 
304 Error Socket::Read(void *buf, size_t &num_bytes) {
305   Error error;
306   int bytes_received = 0;
307   do {
308     bytes_received = ::recv(m_socket, static_cast<char *>(buf), num_bytes, 0);
309   } while (bytes_received < 0 && IsInterrupted());
310 
311   if (bytes_received < 0) {
312     SetLastError(error);
313     num_bytes = 0;
314   } else
315     num_bytes = bytes_received;
316 
317   Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_COMMUNICATION));
318   if (log) {
319     log->Printf("%p Socket::Read() (socket = %" PRIu64
320                 ", src = %p, src_len = %" PRIu64 ", flags = 0) => %" PRIi64
321                 " (error = %s)",
322                 static_cast<void *>(this), static_cast<uint64_t>(m_socket), buf,
323                 static_cast<uint64_t>(num_bytes),
324                 static_cast<int64_t>(bytes_received), error.AsCString());
325   }
326 
327   return error;
328 }
329 
330 Error Socket::Write(const void *buf, size_t &num_bytes) {
331   Error error;
332   int bytes_sent = 0;
333   do {
334     bytes_sent = Send(buf, num_bytes);
335   } while (bytes_sent < 0 && IsInterrupted());
336 
337   if (bytes_sent < 0) {
338     SetLastError(error);
339     num_bytes = 0;
340   } else
341     num_bytes = bytes_sent;
342 
343   Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_COMMUNICATION));
344   if (log) {
345     log->Printf("%p Socket::Write() (socket = %" PRIu64
346                 ", src = %p, src_len = %" PRIu64 ", flags = 0) => %" PRIi64
347                 " (error = %s)",
348                 static_cast<void *>(this), static_cast<uint64_t>(m_socket), buf,
349                 static_cast<uint64_t>(num_bytes),
350                 static_cast<int64_t>(bytes_sent), error.AsCString());
351   }
352 
353   return error;
354 }
355 
356 Error Socket::PreDisconnect() {
357   Error error;
358   return error;
359 }
360 
361 Error Socket::Close() {
362   Error error;
363   if (!IsValid() || !m_should_close_fd)
364     return error;
365 
366   Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_CONNECTION));
367   if (log)
368     log->Printf("%p Socket::Close (fd = %i)", static_cast<void *>(this),
369                 m_socket);
370 
371 #if defined(_WIN32)
372   bool success = !!closesocket(m_socket);
373 #else
374   bool success = !!::close(m_socket);
375 #endif
376   // A reference to a FD was passed in, set it to an invalid value
377   m_socket = kInvalidSocketValue;
378   if (!success) {
379     SetLastError(error);
380   }
381 
382   return error;
383 }
384 
385 int Socket::GetOption(int level, int option_name, int &option_value) {
386   get_socket_option_arg_type option_value_p =
387       reinterpret_cast<get_socket_option_arg_type>(&option_value);
388   socklen_t option_value_size = sizeof(int);
389   return ::getsockopt(m_socket, level, option_name, option_value_p,
390                       &option_value_size);
391 }
392 
393 int Socket::SetOption(int level, int option_name, int option_value) {
394   set_socket_option_arg_type option_value_p =
395       reinterpret_cast<get_socket_option_arg_type>(&option_value);
396   return ::setsockopt(m_socket, level, option_name, option_value_p,
397                       sizeof(option_value));
398 }
399 
400 size_t Socket::Send(const void *buf, const size_t num_bytes) {
401   return ::send(m_socket, static_cast<const char *>(buf), num_bytes, 0);
402 }
403 
404 void Socket::SetLastError(Error &error) {
405 #if defined(_WIN32)
406   error.SetError(::WSAGetLastError(), lldb::eErrorTypeWin32);
407 #else
408   error.SetErrorToErrno();
409 #endif
410 }
411 
412 NativeSocket Socket::CreateSocket(const int domain, const int type,
413                                   const int protocol,
414                                   bool child_processes_inherit, Error &error) {
415   error.Clear();
416   auto socket_type = type;
417 #ifdef SOCK_CLOEXEC
418   if (!child_processes_inherit)
419     socket_type |= SOCK_CLOEXEC;
420 #endif
421   auto sock = ::socket(domain, socket_type, protocol);
422   if (sock == kInvalidSocketValue)
423     SetLastError(error);
424 
425   return sock;
426 }
427 
428 NativeSocket Socket::AcceptSocket(NativeSocket sockfd, struct sockaddr *addr,
429                                   socklen_t *addrlen,
430                                   bool child_processes_inherit, Error &error) {
431   error.Clear();
432 #if defined(ANDROID_USE_ACCEPT_WORKAROUND)
433   // Hack:
434   // This enables static linking lldb-server to an API 21 libc, but still having
435   // it run on older devices. It is necessary because API 21 libc's
436   // implementation of accept() uses the accept4 syscall(), which is not
437   // available in older kernels. Using an older libc would fix this issue, but
438   // introduce other ones, as the old libraries were quite buggy.
439   int fd = syscall(__NR_accept, sockfd, addr, addrlen);
440   if (fd >= 0 && !child_processes_inherit) {
441     int flags = ::fcntl(fd, F_GETFD);
442     if (flags != -1 && ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC) != -1)
443       return fd;
444     SetLastError(error);
445     close(fd);
446   }
447   return fd;
448 #elif defined(SOCK_CLOEXEC)
449   int flags = 0;
450   if (!child_processes_inherit) {
451     flags |= SOCK_CLOEXEC;
452   }
453   NativeSocket fd = ::accept4(sockfd, addr, addrlen, flags);
454 #else
455   NativeSocket fd = ::accept(sockfd, addr, addrlen);
456 #endif
457   if (fd == kInvalidSocketValue)
458     SetLastError(error);
459   return fd;
460 }
461