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/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 static const int kDomain = AF_INET;
25 static const int kType = SOCK_DGRAM;
26 
27 static const char *g_not_supported_error = "Not supported";
28 
29 UDPSocket::UDPSocket(NativeSocket socket) : Socket(ProtocolUdp, true, true) {
30   m_socket = socket;
31 }
32 
33 UDPSocket::UDPSocket(bool should_close, bool child_processes_inherit)
34     : Socket(ProtocolUdp, should_close, child_processes_inherit) {}
35 
36 size_t UDPSocket::Send(const void *buf, const size_t num_bytes) {
37   return ::sendto(m_socket, static_cast<const char *>(buf), num_bytes, 0,
38                   m_sockaddr, m_sockaddr.GetLength());
39 }
40 
41 Status UDPSocket::Connect(llvm::StringRef name) {
42   return Status("%s", g_not_supported_error);
43 }
44 
45 Status UDPSocket::Listen(llvm::StringRef name, int backlog) {
46   return Status("%s", g_not_supported_error);
47 }
48 
49 Status UDPSocket::Accept(Socket *&socket) {
50   return Status("%s", g_not_supported_error);
51 }
52 
53 llvm::Expected<std::unique_ptr<UDPSocket>>
54 UDPSocket::Connect(llvm::StringRef name, bool child_processes_inherit) {
55   std::unique_ptr<UDPSocket> socket;
56 
57   Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_CONNECTION));
58   LLDB_LOG(log, "host/port = {0}", name);
59 
60   Status error;
61   std::string host_str;
62   std::string port_str;
63   uint16_t port;
64   if (llvm::Error decode_error =
65           DecodeHostAndPort(name, host_str, port_str, port))
66     return std::move(decode_error);
67 
68   // At this point we have setup the receive port, now we need to setup the UDP
69   // send socket
70 
71   struct addrinfo hints;
72   struct addrinfo *service_info_list = nullptr;
73 
74   ::memset(&hints, 0, sizeof(hints));
75   hints.ai_family = kDomain;
76   hints.ai_socktype = kType;
77   int err = ::getaddrinfo(host_str.c_str(), port_str.c_str(), &hints,
78                           &service_info_list);
79   if (err != 0) {
80     error.SetErrorStringWithFormat(
81 #if defined(_WIN32) && defined(UNICODE)
82         "getaddrinfo(%s, %s, &hints, &info) returned error %i (%S)",
83 #else
84         "getaddrinfo(%s, %s, &hints, &info) returned error %i (%s)",
85 #endif
86         host_str.c_str(), port_str.c_str(), err, gai_strerror(err));
87     return error.ToError();
88   }
89 
90   for (struct addrinfo *service_info_ptr = service_info_list;
91        service_info_ptr != nullptr;
92        service_info_ptr = service_info_ptr->ai_next) {
93     auto send_fd = CreateSocket(
94         service_info_ptr->ai_family, service_info_ptr->ai_socktype,
95         service_info_ptr->ai_protocol, child_processes_inherit, error);
96     if (error.Success()) {
97       socket.reset(new UDPSocket(send_fd));
98       socket->m_sockaddr = service_info_ptr;
99       break;
100     } else
101       continue;
102   }
103 
104   ::freeaddrinfo(service_info_list);
105 
106   if (!socket)
107     return error.ToError();
108 
109   SocketAddress bind_addr;
110 
111   // Only bind to the loopback address if we are expecting a connection from
112   // localhost to avoid any firewall issues.
113   const bool bind_addr_success = (host_str == "127.0.0.1" || host_str == "localhost")
114                                      ? bind_addr.SetToLocalhost(kDomain, port)
115                                      : bind_addr.SetToAnyAddress(kDomain, port);
116 
117   if (!bind_addr_success) {
118     error.SetErrorString("Failed to get hostspec to bind for");
119     return error.ToError();
120   }
121 
122   bind_addr.SetPort(0); // Let the source port # be determined dynamically
123 
124   err = ::bind(socket->GetNativeSocket(), bind_addr, bind_addr.GetLength());
125 
126   struct sockaddr_in source_info;
127   socklen_t address_len = sizeof (struct sockaddr_in);
128   err = ::getsockname(socket->GetNativeSocket(),
129                       (struct sockaddr *)&source_info, &address_len);
130 
131   return std::move(socket);
132 }
133 
134 std::string UDPSocket::GetRemoteConnectionURI() const {
135   if (m_socket != kInvalidSocketValue) {
136     return std::string(llvm::formatv(
137         "udp://[{0}]:{1}", m_sockaddr.GetIPAddress(), m_sockaddr.GetPort()));
138   }
139   return "";
140 }
141