contrib/llvm-project/lldb/source/Host/posix/HostInfoPosix.cpp

   1 //===-- HostInfoPosix.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/HostInfoPosix.h"
  10 #include "lldb/Utility/UserIDResolver.h"
  11 #include "lldb/Utility/Log.h"
  12
  13 #include "llvm/ADT/SmallString.h"
  14 #include "llvm/ADT/Twine.h"
  15 #include "llvm/Support/Path.h"
  16 #include "llvm/Support/raw_ostream.h"
  17
  18 #include <grp.h>
  19 #include <limits.h>
  20 #include <mutex>
  21 #include <netdb.h>
  22 #include <pwd.h>
  23 #include <stdlib.h>
  24 #include <sys/types.h>
  25 #include <unistd.h>
  26
  27 using namespace lldb_private;
  28
  29 size_t HostInfoPosix::GetPageSize() { return ::getpagesize(); }
  30
  31 bool HostInfoPosix::GetHostname(std::string &s) {
  32   char hostname[PATH_MAX];
  33   hostname[sizeof(hostname) - 1] = '\0';
  34   if (::gethostname(hostname, sizeof(hostname) - 1) == 0) {
  35     struct hostent *h = ::gethostbyname(hostname);
  36     if (h)
  37       s.assign(h->h_name);
  38     else
  39       s.assign(hostname);
  40     return true;
  41   }
  42   return false;
  43 }
  44
  45 #ifdef __ANDROID__
  46 #include <android/api-level.h>
  47 #endif
  48 #if defined(__ANDROID_API__) && __ANDROID_API__ < 21
  49 #define USE_GETPWUID
  50 #endif
  51
  52 namespace {
  53 class PosixUserIDResolver : public UserIDResolver {
  54 protected:
  55   llvm::Optional<std::string> DoGetUserName(id_t uid) override;
  56   llvm::Optional<std::string> DoGetGroupName(id_t gid) override;
  57 };
  58 } // namespace
  59
  60 llvm::Optional<std::string> PosixUserIDResolver::DoGetUserName(id_t uid) {
  61 #ifdef USE_GETPWUID
  62   // getpwuid_r is missing from android-9
  63   // UserIDResolver provides some thread safety by making sure noone calls this
  64   // function concurrently, but using getpwuid is ultimately not thread-safe as
  65   // we don't know who else might be calling it.
  66   struct passwd *user_info_ptr = ::getpwuid(uid);
  67   if (user_info_ptr)
  68     return std::string(user_info_ptr->pw_name);
  69 #else
  70   struct passwd user_info;
  71   struct passwd *user_info_ptr = &user_info;
  72   char user_buffer[PATH_MAX];
  73   size_t user_buffer_size = sizeof(user_buffer);
  74   if (::getpwuid_r(uid, &user_info, user_buffer, user_buffer_size,
  75                    &user_info_ptr) == 0 &&
  76       user_info_ptr) {
  77     return std::string(user_info_ptr->pw_name);
  78   }
  79 #endif
  80   return llvm::None;
  81 }
  82
  83 llvm::Optional<std::string> PosixUserIDResolver::DoGetGroupName(id_t gid) {
  84 #ifndef __ANDROID__
  85   char group_buffer[PATH_MAX];
  86   size_t group_buffer_size = sizeof(group_buffer);
  87   struct group group_info;
  88   struct group *group_info_ptr = &group_info;
  89   // Try the threadsafe version first
  90   if (::getgrgid_r(gid, &group_info, group_buffer, group_buffer_size,
  91                    &group_info_ptr) == 0) {
  92     if (group_info_ptr)
  93       return std::string(group_info_ptr->gr_name);
  94   } else {
  95     // The threadsafe version isn't currently working for me on darwin, but the
  96     // non-threadsafe version is, so I am calling it below.
  97     group_info_ptr = ::getgrgid(gid);
  98     if (group_info_ptr)
  99       return std::string(group_info_ptr->gr_name);
 100   }
 101 #else
 102   assert(false && "getgrgid_r() not supported on Android");
 103 #endif
 104   return llvm::None;
 105 }
 106
 107 static llvm::ManagedStatic<PosixUserIDResolver> g_user_id_resolver;
 108
 109 UserIDResolver &HostInfoPosix::GetUserIDResolver() {
 110   return *g_user_id_resolver;
 111 }
 112
 113 uint32_t HostInfoPosix::GetUserID() { return getuid(); }
 114
 115 uint32_t HostInfoPosix::GetGroupID() { return getgid(); }
 116
 117 uint32_t HostInfoPosix::GetEffectiveUserID() { return geteuid(); }
 118
 119 uint32_t HostInfoPosix::GetEffectiveGroupID() { return getegid(); }
 120
 121 FileSpec HostInfoPosix::GetDefaultShell() { return FileSpec("/bin/sh"); }
 122
 123 bool HostInfoPosix::ComputeSupportExeDirectory(FileSpec &file_spec) {
 124   return ComputePathRelativeToLibrary(file_spec, "/bin");
 125 }
 126
 127 bool HostInfoPosix::ComputeHeaderDirectory(FileSpec &file_spec) {
 128   FileSpec temp_file("/opt/local/include/lldb");
 129   file_spec.GetDirectory().SetCString(temp_file.GetPath().c_str());
 130   return true;
 131 }
 132
 133 bool HostInfoPosix::GetEnvironmentVar(const std::string &var_name,
 134                                       std::string &var) {
 135   if (const char *pvar = ::getenv(var_name.c_str())) {
 136     var = std::string(pvar);
 137     return true;
 138   }
 139   return false;
 140 }