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/Log.h"
  11 #include "lldb/Utility/UserIDResolver.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 <pwd.h>
  22 #include <stdlib.h>
  23 #include <sys/types.h>
  24 #include <unistd.h>
  25
  26 using namespace lldb_private;
  27
  28 size_t HostInfoPosix::GetPageSize() { return ::getpagesize(); }
  29
  30 bool HostInfoPosix::GetHostname(std::string &s) {
  31   char hostname[PATH_MAX];
  32   hostname[sizeof(hostname) - 1] = '\0';
  33   if (::gethostname(hostname, sizeof(hostname) - 1) == 0) {
  34     s.assign(hostname);
  35     return true;
  36   }
  37   return false;
  38 }
  39
  40 #ifdef __ANDROID__
  41 #include <android/api-level.h>
  42 #endif
  43 #if defined(__ANDROID_API__) && __ANDROID_API__ < 21
  44 #define USE_GETPWUID
  45 #endif
  46
  47 namespace {
  48 class PosixUserIDResolver : public UserIDResolver {
  49 protected:
  50   llvm::Optional<std::string> DoGetUserName(id_t uid) override;
  51   llvm::Optional<std::string> DoGetGroupName(id_t gid) override;
  52 };
  53 } // namespace
  54
  55 struct PasswdEntry {
  56   std::string username;
  57   std::string shell;
  58 };
  59
  60 static llvm::Optional<PasswdEntry> GetPassword(id_t uid) {
  61 #ifdef USE_GETPWUID
  62   // getpwuid_r is missing from android-9
  63   // The caller should provide some thread safety by making sure no one calls
  64   // this function concurrently, because using getpwuid is ultimately not
  65   // thread-safe as we don't know who else might be calling it.
  66   if (auto *user_info_ptr = ::getpwuid(uid))
  67     return PasswdEntry{user_info_ptr->pw_name, user_info_ptr->pw_shell};
  68 #else
  69   struct passwd user_info;
  70   struct passwd *user_info_ptr = &user_info;
  71   char user_buffer[PATH_MAX];
  72   size_t user_buffer_size = sizeof(user_buffer);
  73   if (::getpwuid_r(uid, &user_info, user_buffer, user_buffer_size,
  74                    &user_info_ptr) == 0 &&
  75       user_info_ptr) {
  76     return PasswdEntry{user_info_ptr->pw_name, user_info_ptr->pw_shell};
  77   }
  78 #endif
  79   return llvm::None;
  80 }
  81
  82 llvm::Optional<std::string> PosixUserIDResolver::DoGetUserName(id_t uid) {
  83   if (llvm::Optional<PasswdEntry> password = GetPassword(uid))
  84     return password->username;
  85   return llvm::None;
  86 }
  87
  88 llvm::Optional<std::string> PosixUserIDResolver::DoGetGroupName(id_t gid) {
  89 #ifndef __ANDROID__
  90   char group_buffer[PATH_MAX];
  91   size_t group_buffer_size = sizeof(group_buffer);
  92   struct group group_info;
  93   struct group *group_info_ptr = &group_info;
  94   // Try the threadsafe version first
  95   if (::getgrgid_r(gid, &group_info, group_buffer, group_buffer_size,
  96                    &group_info_ptr) == 0) {
  97     if (group_info_ptr)
  98       return std::string(group_info_ptr->gr_name);
  99   } else {
 100     // The threadsafe version isn't currently working for me on darwin, but the
 101     // non-threadsafe version is, so I am calling it below.
 102     group_info_ptr = ::getgrgid(gid);
 103     if (group_info_ptr)
 104       return std::string(group_info_ptr->gr_name);
 105   }
 106 #endif
 107   return llvm::None;
 108 }
 109
 110 static llvm::ManagedStatic<PosixUserIDResolver> g_user_id_resolver;
 111
 112 UserIDResolver &HostInfoPosix::GetUserIDResolver() {
 113   return *g_user_id_resolver;
 114 }
 115
 116 uint32_t HostInfoPosix::GetUserID() { return getuid(); }
 117
 118 uint32_t HostInfoPosix::GetGroupID() { return getgid(); }
 119
 120 uint32_t HostInfoPosix::GetEffectiveUserID() { return geteuid(); }
 121
 122 uint32_t HostInfoPosix::GetEffectiveGroupID() { return getegid(); }
 123
 124 FileSpec HostInfoPosix::GetDefaultShell() {
 125   if (const char *v = ::getenv("SHELL"))
 126     return FileSpec(v);
 127   if (llvm::Optional<PasswdEntry> password = GetPassword(::geteuid()))
 128     return FileSpec(password->shell);
 129   return FileSpec("/bin/sh");
 130 }
 131
 132 bool HostInfoPosix::ComputeSupportExeDirectory(FileSpec &file_spec) {
 133   return ComputePathRelativeToLibrary(file_spec, "/bin");
 134 }
 135
 136 bool HostInfoPosix::ComputeHeaderDirectory(FileSpec &file_spec) {
 137   FileSpec temp_file("/opt/local/include/lldb");
 138   file_spec.GetDirectory().SetCString(temp_file.GetPath().c_str());
 139   return true;
 140 }
 141
 142 bool HostInfoPosix::GetEnvironmentVar(const std::string &var_name,
 143                                       std::string &var) {
 144   if (const char *pvar = ::getenv(var_name.c_str())) {
 145     var = std::string(pvar);
 146     return true;
 147   }
 148   return false;
 149 }