1 //===-- UDPSocket.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 "lldb/Host/common/UDPSocket.h"
10 
11 #include "lldb/Host/Config.h"
12 #include "lldb/Utility/Log.h"
13 
14 #if LLDB_ENABLE_POSIX
15 #include <arpa/inet.h>
16 #include <sys/socket.h>
17 #endif
18 
19 #include <memory>
20 
21 using namespace lldb;
22 using namespace lldb_private;
23 
24 namespace {
25 
26 const int kDomain = AF_INET;
27 const int kType = SOCK_DGRAM;
28 
29 static const char *g_not_supported_error = "Not supported";
30 }
31 
32 UDPSocket::UDPSocket(NativeSocket socket) : Socket(ProtocolUdp, true, true) {
33   m_socket = socket;
34 }
35 
36 UDPSocket::UDPSocket(bool should_close, bool child_processes_inherit)
37     : Socket(ProtocolUdp, should_close, child_processes_inherit) {}
38 
39 size_t UDPSocket::Send(const void *buf, const size_t num_bytes) {
40   return ::sendto(m_socket, static_cast<const char *>(buf), num_bytes, 0,
41                   m_sockaddr, m_sockaddr.GetLength());
42 }
43 
44 Status UDPSocket::Connect(llvm::StringRef name) {
45   return Status("%s", g_not_supported_error);
46 }
47 
48 Status UDPSocket::Listen(llvm::StringRef name, int backlog) {
49   return Status("%s", g_not_supported_error);
50 }
51 
52 Status UDPSocket::Accept(Socket *&socket) {
53   return Status("%s", g_not_supported_error);
54 }
55 
56 Status UDPSocket::Connect(llvm::StringRef name, bool child_processes_inherit,
57                           Socket *&socket) {
58   std::unique_ptr<UDPSocket> final_socket;
59 
60   Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_CONNECTION));
61   LLDB_LOGF(log, "UDPSocket::%s (host/port = %s)", __FUNCTION__, name.data());
62 
63   Status error;
64   std::string host_str;
65   std::string port_str;
66   int32_t port = INT32_MIN;
67   if (!DecodeHostAndPort(name, host_str, port_str, port, &error))
68     return error;
69 
70   // At this point we have setup the receive port, now we need to setup the UDP
71   // send socket
72 
73   struct addrinfo hints;
74   struct addrinfo *service_info_list = nullptr;
75 
76   ::memset(&hints, 0, sizeof(hints));
77   hints.ai_family = kDomain;
78   hints.ai_socktype = kType;
79   int err = ::getaddrinfo(host_str.c_str(), port_str.c_str(), &hints,
80                           &service_info_list);
81   if (err != 0) {
82     error.SetErrorStringWithFormat(
83 #if defined(_WIN32) && defined(UNICODE)
84         "getaddrinfo(%s, %s, &hints, &info) returned error %i (%S)",
85 #else
86         "getaddrinfo(%s, %s, &hints, &info) returned error %i (%s)",
87 #endif
88         host_str.c_str(), port_str.c_str(), err, gai_strerror(err));
89     return error;
90   }
91 
92   for (struct addrinfo *service_info_ptr = service_info_list;
93        service_info_ptr != nullptr;
94        service_info_ptr = service_info_ptr->ai_next) {
95     auto send_fd = CreateSocket(
96         service_info_ptr->ai_family, service_info_ptr->ai_socktype,
97         service_info_ptr->ai_protocol, child_processes_inherit, error);
98     if (error.Success()) {
99       final_socket.reset(new UDPSocket(send_fd));
100       final_socket->m_sockaddr = service_info_ptr;
101       break;
102     } else
103       continue;
104   }
105 
106   ::freeaddrinfo(service_info_list);
107 
108   if (!final_socket)
109     return error;
110 
111   SocketAddress bind_addr;
112 
113   // Only bind to the loopback address if we are expecting a connection from
114   // localhost to avoid any firewall issues.
115   const bool bind_addr_success = (host_str == "127.0.0.1" || host_str == "localhost")
116                                      ? bind_addr.SetToLocalhost(kDomain, port)
117                                      : bind_addr.SetToAnyAddress(kDomain, port);
118 
119   if (!bind_addr_success) {
120     error.SetErrorString("Failed to get hostspec to bind for");
121     return error;
122   }
123 
124   bind_addr.SetPort(0); // Let the source port # be determined dynamically
125 
126   err = ::bind(final_socket->GetNativeSocket(), bind_addr, bind_addr.GetLength());
127 
128   struct sockaddr_in source_info;
129   socklen_t address_len = sizeof (struct sockaddr_in);
130   err = ::getsockname(final_socket->GetNativeSocket(), (struct sockaddr *) &source_info, &address_len);
131 
132   socket = final_socket.release();
133   error.Clear();
134   return error;
135 }
136 
137 std::string UDPSocket::GetRemoteConnectionURI() const {
138   if (m_socket != kInvalidSocketValue) {
139     return llvm::formatv("udp://[{0}]:{1}", m_sockaddr.GetIPAddress(),
140                          m_sockaddr.GetPort());
141   }
142   return "";
143 }
144