lldb/source/Host/posix/DomainSocket.cpp

   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
  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 static const int kDomain = AF_UNIX;
  30 static const int kType = SOCK_STREAM;
  31
  32 static 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   saddr_un->sun_len = saddr_un_len;
  53 #endif
  54
  55   return true;
  56 }
  57
  58 DomainSocket::DomainSocket(bool should_close, bool child_processes_inherit)
  59     : Socket(ProtocolUnixDomain, should_close, child_processes_inherit) {}
  60
  61 DomainSocket::DomainSocket(SocketProtocol protocol,
  62                            bool child_processes_inherit)
  63     : Socket(protocol, true, child_processes_inherit) {}
  64
  65 DomainSocket::DomainSocket(NativeSocket socket,
  66                            const DomainSocket &listen_socket)
  67     : Socket(ProtocolUnixDomain, listen_socket.m_should_close_fd,
  68              listen_socket.m_child_processes_inherit) {
  69   m_socket = socket;
  70 }
  71
  72 Status DomainSocket::Connect(llvm::StringRef name) {
  73   sockaddr_un saddr_un;
  74   socklen_t saddr_un_len;
  75   if (!SetSockAddr(name, GetNameOffset(), &saddr_un, saddr_un_len))
  76     return Status("Failed to set socket address");
  77
  78   Status error;
  79   m_socket = CreateSocket(kDomain, kType, 0, m_child_processes_inherit, error);
  80   if (error.Fail())
  81     return error;
  82   if (llvm::sys::RetryAfterSignal(-1, ::connect, GetNativeSocket(),
  83         (struct sockaddr *)&saddr_un, saddr_un_len) < 0)
  84     SetLastError(error);
  85
  86   return error;
  87 }
  88
  89 Status DomainSocket::Listen(llvm::StringRef name, int backlog) {
  90   sockaddr_un saddr_un;
  91   socklen_t saddr_un_len;
  92   if (!SetSockAddr(name, GetNameOffset(), &saddr_un, saddr_un_len))
  93     return Status("Failed to set socket address");
  94
  95   DeleteSocketFile(name);
  96
  97   Status error;
  98   m_socket = CreateSocket(kDomain, kType, 0, m_child_processes_inherit, error);
  99   if (error.Fail())
 100     return error;
 101   if (::bind(GetNativeSocket(), (struct sockaddr *)&saddr_un, saddr_un_len) ==
 102       0)
 103     if (::listen(GetNativeSocket(), backlog) == 0)
 104       return error;
 105
 106   SetLastError(error);
 107   return error;
 108 }
 109
 110 Status DomainSocket::Accept(Socket *&socket) {
 111   Status error;
 112   auto conn_fd = AcceptSocket(GetNativeSocket(), nullptr, nullptr,
 113                               m_child_processes_inherit, error);
 114   if (error.Success())
 115     socket = new DomainSocket(conn_fd, *this);
 116
 117   return error;
 118 }
 119
 120 size_t DomainSocket::GetNameOffset() const { return 0; }
 121
 122 void DomainSocket::DeleteSocketFile(llvm::StringRef name) {
 123   llvm::sys::fs::remove(name);
 124 }
 125
 126 std::string DomainSocket::GetSocketName() const {
 127   if (m_socket == kInvalidSocketValue)
 128     return "";
 129
 130   struct sockaddr_un saddr_un;
 131   saddr_un.sun_family = AF_UNIX;
 132   socklen_t sock_addr_len = sizeof(struct sockaddr_un);
 133   if (::getpeername(m_socket, (struct sockaddr *)&saddr_un, &sock_addr_len) !=
 134       0)
 135     return "";
 136
 137   if (sock_addr_len <= offsetof(struct sockaddr_un, sun_path))
 138     return ""; // Unnamed domain socket
 139
 140   llvm::StringRef name(saddr_un.sun_path + GetNameOffset(),
 141                        sock_addr_len - offsetof(struct sockaddr_un, sun_path) -
 142                            GetNameOffset());
 143   name = name.rtrim('\0');
 144
 145   return name.str();
 146 }
 147
 148 std::string DomainSocket::GetRemoteConnectionURI() const {
 149   std::string name = GetSocketName();
 150   if (name.empty())
 151     return name;
 152
 153   return llvm::formatv(
 154       "{0}://{1}",
 155       GetNameOffset() == 0 ? "unix-connect" : "unix-abstract-connect", name);
 156 }