1 //===-- DomainSocket.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/posix/DomainSocket.h"
10 
11 #include "llvm/Support/Errno.h"
12 #include "llvm/Support/FileSystem.h"
13 
14 #include <stddef.h>
15 #include <sys/socket.h>
16 #include <sys/un.h>
17 
18 using namespace lldb;
19 using namespace lldb_private;
20 
21 #ifdef __ANDROID__
22 // Android does not have SUN_LEN
23 #ifndef SUN_LEN
24 #define SUN_LEN(ptr)                                                           \
25   (offsetof(struct sockaddr_un, sun_path) + strlen((ptr)->sun_path))
26 #endif
27 #endif // #ifdef __ANDROID__
28 
29 namespace {
30 
31 const int kDomain = AF_UNIX;
32 const int kType = SOCK_STREAM;
33 
34 bool SetSockAddr(llvm::StringRef name, const size_t name_offset,
35                  sockaddr_un *saddr_un, socklen_t &saddr_un_len) {
36   if (name.size() + name_offset > sizeof(saddr_un->sun_path))
37     return false;
38 
39   memset(saddr_un, 0, sizeof(*saddr_un));
40   saddr_un->sun_family = kDomain;
41 
42   memcpy(saddr_un->sun_path + name_offset, name.data(), name.size());
43 
44   // For domain sockets we can use SUN_LEN in order to calculate size of
45   // sockaddr_un, but for abstract sockets we have to calculate size manually
46   // because of leading null symbol.
47   if (name_offset == 0)
48     saddr_un_len = SUN_LEN(saddr_un);
49   else
50     saddr_un_len =
51         offsetof(struct sockaddr_un, sun_path) + name_offset + name.size();
52 
53 #if defined(__APPLE__) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__)
54   saddr_un->sun_len = saddr_un_len;
55 #endif
56 
57   return true;
58 }
59 } // namespace
60 
61 DomainSocket::DomainSocket(bool should_close, bool child_processes_inherit)
62     : Socket(ProtocolUnixDomain, should_close, child_processes_inherit) {}
63 
64 DomainSocket::DomainSocket(SocketProtocol protocol,
65                            bool child_processes_inherit)
66     : Socket(protocol, true, child_processes_inherit) {}
67 
68 DomainSocket::DomainSocket(NativeSocket socket,
69                            const DomainSocket &listen_socket)
70     : Socket(ProtocolUnixDomain, listen_socket.m_should_close_fd,
71              listen_socket.m_child_processes_inherit) {
72   m_socket = socket;
73 }
74 
75 Status DomainSocket::Connect(llvm::StringRef name) {
76   sockaddr_un saddr_un;
77   socklen_t saddr_un_len;
78   if (!SetSockAddr(name, GetNameOffset(), &saddr_un, saddr_un_len))
79     return Status("Failed to set socket address");
80 
81   Status error;
82   m_socket = CreateSocket(kDomain, kType, 0, m_child_processes_inherit, error);
83   if (error.Fail())
84     return error;
85   if (llvm::sys::RetryAfterSignal(-1, ::connect, GetNativeSocket(),
86         (struct sockaddr *)&saddr_un, saddr_un_len) < 0)
87     SetLastError(error);
88 
89   return error;
90 }
91 
92 Status DomainSocket::Listen(llvm::StringRef name, int backlog) {
93   sockaddr_un saddr_un;
94   socklen_t saddr_un_len;
95   if (!SetSockAddr(name, GetNameOffset(), &saddr_un, saddr_un_len))
96     return Status("Failed to set socket address");
97 
98   DeleteSocketFile(name);
99 
100   Status error;
101   m_socket = CreateSocket(kDomain, kType, 0, m_child_processes_inherit, error);
102   if (error.Fail())
103     return error;
104   if (::bind(GetNativeSocket(), (struct sockaddr *)&saddr_un, saddr_un_len) ==
105       0)
106     if (::listen(GetNativeSocket(), backlog) == 0)
107       return error;
108 
109   SetLastError(error);
110   return error;
111 }
112 
113 Status DomainSocket::Accept(Socket *&socket) {
114   Status error;
115   auto conn_fd = AcceptSocket(GetNativeSocket(), nullptr, nullptr,
116                               m_child_processes_inherit, error);
117   if (error.Success())
118     socket = new DomainSocket(conn_fd, *this);
119 
120   return error;
121 }
122 
123 size_t DomainSocket::GetNameOffset() const { return 0; }
124 
125 void DomainSocket::DeleteSocketFile(llvm::StringRef name) {
126   llvm::sys::fs::remove(name);
127 }
128 
129 std::string DomainSocket::GetSocketName() const {
130   if (m_socket != kInvalidSocketValue) {
131     struct sockaddr_un saddr_un;
132     saddr_un.sun_family = AF_UNIX;
133     socklen_t sock_addr_len = sizeof(struct sockaddr_un);
134     if (::getpeername(m_socket, (struct sockaddr *)&saddr_un, &sock_addr_len) ==
135         0) {
136       std::string name(saddr_un.sun_path + GetNameOffset(),
137                        sock_addr_len -
138                            offsetof(struct sockaddr_un, sun_path) -
139                            GetNameOffset());
140       if (name.back() == '\0') name.pop_back();
141       return name;
142     }
143   }
144   return "";
145 }
146 
147 std::string DomainSocket::GetRemoteConnectionURI() const {
148   if (m_socket != kInvalidSocketValue) {
149     return llvm::formatv("{0}://{1}",
150                          GetNameOffset() == 0 ? "unix-connect"
151                                               : "unix-abstract-connect",
152                          GetSocketName());
153   }
154   return "";
155 }
156