1 //===-- DomainSocket.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/posix/DomainSocket.h"
11 
12 #include "lldb/Host/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__)
54   saddr_un->sun_len = saddr_un_len;
55 #endif
56 
57   return true;
58 }
59 }
60 
61 DomainSocket::DomainSocket(NativeSocket socket)
62     : Socket(socket, ProtocolUnixDomain, true) {}
63 
64 DomainSocket::DomainSocket(bool child_processes_inherit, Error &error)
65     : DomainSocket(
66           CreateSocket(kDomain, kType, 0, child_processes_inherit, error)) {}
67 
68 DomainSocket::DomainSocket(SocketProtocol protocol,
69                            bool child_processes_inherit, Error &error)
70     : Socket(CreateSocket(kDomain, kType, 0, child_processes_inherit, error),
71              protocol, true) {}
72 
73 Error DomainSocket::Connect(llvm::StringRef name) {
74   sockaddr_un saddr_un;
75   socklen_t saddr_un_len;
76   if (!SetSockAddr(name, GetNameOffset(), &saddr_un, saddr_un_len))
77     return Error("Failed to set socket address");
78 
79   Error error;
80   if (::connect(GetNativeSocket(), (struct sockaddr *)&saddr_un, saddr_un_len) <
81       0)
82     SetLastError(error);
83 
84   return error;
85 }
86 
87 Error DomainSocket::Listen(llvm::StringRef name, int backlog) {
88   sockaddr_un saddr_un;
89   socklen_t saddr_un_len;
90   if (!SetSockAddr(name, GetNameOffset(), &saddr_un, saddr_un_len))
91     return Error("Failed to set socket address");
92 
93   DeleteSocketFile(name);
94 
95   Error error;
96   if (::bind(GetNativeSocket(), (struct sockaddr *)&saddr_un, saddr_un_len) ==
97       0)
98     if (::listen(GetNativeSocket(), backlog) == 0)
99       return error;
100 
101   SetLastError(error);
102   return error;
103 }
104 
105 Error DomainSocket::Accept(llvm::StringRef name, bool child_processes_inherit,
106                            Socket *&socket) {
107   Error error;
108   auto conn_fd = AcceptSocket(GetNativeSocket(), nullptr, nullptr,
109                               child_processes_inherit, error);
110   if (error.Success())
111     socket = new DomainSocket(conn_fd);
112 
113   return error;
114 }
115 
116 size_t DomainSocket::GetNameOffset() const { return 0; }
117 
118 void DomainSocket::DeleteSocketFile(llvm::StringRef name) {
119   FileSystem::Unlink(FileSpec{name, true});
120 }
121