1//===-- DomainSocket.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/posix/DomainSocket.h"
10
11#include "llvm/Support/Errno.h"
12#include "llvm/Support/FileSystem.h"
13
14#include <cstddef>
15#include <sys/socket.h>
16#include <sys/un.h>
17
18using namespace lldb;
19using 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
29static const int kDomain = AF_UNIX;
30static const int kType = SOCK_STREAM;
31
32static bool SetSockAddr(llvm::StringRef name, const size_t name_offset,
33                        sockaddr_un *saddr_un, socklen_t &saddr_un_len) {
34  if (name.size() + name_offset > sizeof(saddr_un->sun_path))
35    return false;
36
37  memset(saddr_un, 0, sizeof(*saddr_un));
38  saddr_un->sun_family = kDomain;
39
40  memcpy(saddr_un->sun_path + name_offset, name.data(), name.size());
41
42  // For domain sockets we can use SUN_LEN in order to calculate size of
43  // sockaddr_un, but for abstract sockets we have to calculate size manually
44  // because of leading null symbol.
45  if (name_offset == 0)
46    saddr_un_len = SUN_LEN(saddr_un);
47  else
48    saddr_un_len =
49        offsetof(struct sockaddr_un, sun_path) + name_offset + name.size();
50
51#if defined(__APPLE__) || defined(__FreeBSD__) || defined(__NetBSD__) ||       \
52    defined(__OpenBSD__)
53  saddr_un->sun_len = saddr_un_len;
54#endif
55
56  return true;
57}
58
59DomainSocket::DomainSocket(bool should_close, bool child_processes_inherit)
60    : Socket(ProtocolUnixDomain, should_close, child_processes_inherit) {}
61
62DomainSocket::DomainSocket(SocketProtocol protocol,
63                           bool child_processes_inherit)
64    : Socket(protocol, true, child_processes_inherit) {}
65
66DomainSocket::DomainSocket(NativeSocket socket,
67                           const DomainSocket &listen_socket)
68    : Socket(ProtocolUnixDomain, listen_socket.m_should_close_fd,
69             listen_socket.m_child_processes_inherit) {
70  m_socket = socket;
71}
72
73Status 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 Status("Failed to set socket address");
78
79  Status error;
80  m_socket = CreateSocket(kDomain, kType, 0, m_child_processes_inherit, error);
81  if (error.Fail())
82    return error;
83  if (llvm::sys::RetryAfterSignal(-1, ::connect, GetNativeSocket(),
84        (struct sockaddr *)&saddr_un, saddr_un_len) < 0)
85    SetLastError(error);
86
87  return error;
88}
89
90Status DomainSocket::Listen(llvm::StringRef name, int backlog) {
91  sockaddr_un saddr_un;
92  socklen_t saddr_un_len;
93  if (!SetSockAddr(name, GetNameOffset(), &saddr_un, saddr_un_len))
94    return Status("Failed to set socket address");
95
96  DeleteSocketFile(name);
97
98  Status error;
99  m_socket = CreateSocket(kDomain, kType, 0, m_child_processes_inherit, error);
100  if (error.Fail())
101    return error;
102  if (::bind(GetNativeSocket(), (struct sockaddr *)&saddr_un, saddr_un_len) ==
103      0)
104    if (::listen(GetNativeSocket(), backlog) == 0)
105      return error;
106
107  SetLastError(error);
108  return error;
109}
110
111Status DomainSocket::Accept(Socket *&socket) {
112  Status error;
113  auto conn_fd = AcceptSocket(GetNativeSocket(), nullptr, nullptr,
114                              m_child_processes_inherit, error);
115  if (error.Success())
116    socket = new DomainSocket(conn_fd, *this);
117
118  return error;
119}
120
121size_t DomainSocket::GetNameOffset() const { return 0; }
122
123void DomainSocket::DeleteSocketFile(llvm::StringRef name) {
124  llvm::sys::fs::remove(name);
125}
126
127std::string DomainSocket::GetSocketName() const {
128  if (m_socket == kInvalidSocketValue)
129    return "";
130
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    return "";
137
138  if (sock_addr_len <= offsetof(struct sockaddr_un, sun_path))
139    return ""; // Unnamed domain socket
140
141  llvm::StringRef name(saddr_un.sun_path + GetNameOffset(),
142                       sock_addr_len - offsetof(struct sockaddr_un, sun_path) -
143                           GetNameOffset());
144  name = name.rtrim('\0');
145
146  return name.str();
147}
148
149std::string DomainSocket::GetRemoteConnectionURI() const {
150  std::string name = GetSocketName();
151  if (name.empty())
152    return name;
153
154  return llvm::formatv(
155      "{0}://{1}",
156      GetNameOffset() == 0 ? "unix-connect" : "unix-abstract-connect", name);
157}
158