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 <stddef.h>
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
29namespace {
30
31const int kDomain = AF_UNIX;
32const int kType = SOCK_STREAM;
33
34bool 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} // namespace
60
61DomainSocket::DomainSocket(bool should_close, bool child_processes_inherit)
62    : Socket(ProtocolUnixDomain, should_close, child_processes_inherit) {}
63
64DomainSocket::DomainSocket(SocketProtocol protocol,
65                           bool child_processes_inherit)
66    : Socket(protocol, true, child_processes_inherit) {}
67
68DomainSocket::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
75Status 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
92Status 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
113Status 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
123size_t DomainSocket::GetNameOffset() const { return 0; }
124
125void DomainSocket::DeleteSocketFile(llvm::StringRef name) {
126  llvm::sys::fs::remove(name);
127}
128
129std::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
147std::string DomainSocket::GetRemoteConnectionURI() const {
148  if (m_socket != kInvalidSocketValue) {
149    return std::string(llvm::formatv(
150        "{0}://{1}",
151        GetNameOffset() == 0 ? "unix-connect" : "unix-abstract-connect",
152        GetSocketName()));
153  }
154  return "";
155}
156