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