1//===-- HostInfoPosix.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/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 <climits>
19#include <cstdlib>
20#include <grp.h>
21#include <mutex>
22#include <optional>
23#include <pwd.h>
24#include <sys/types.h>
25#include <sys/utsname.h>
26#include <unistd.h>
27
28using namespace lldb_private;
29
30size_t HostInfoPosix::GetPageSize() { return ::getpagesize(); }
31
32bool HostInfoPosix::GetHostname(std::string &s) {
33  char hostname[PATH_MAX];
34  hostname[sizeof(hostname) - 1] = '\0';
35  if (::gethostname(hostname, sizeof(hostname) - 1) == 0) {
36    s.assign(hostname);
37    return true;
38  }
39  return false;
40}
41
42std::optional<std::string> HostInfoPosix::GetOSKernelDescription() {
43  struct utsname un;
44  if (uname(&un) < 0)
45    return std::nullopt;
46
47  return std::string(un.version);
48}
49
50#ifdef __ANDROID__
51#include <android/api-level.h>
52#endif
53#if defined(__ANDROID_API__) && __ANDROID_API__ < 21
54#define USE_GETPWUID
55#endif
56
57namespace {
58class PosixUserIDResolver : public UserIDResolver {
59protected:
60  std::optional<std::string> DoGetUserName(id_t uid) override;
61  std::optional<std::string> DoGetGroupName(id_t gid) override;
62};
63} // namespace
64
65struct PasswdEntry {
66  std::string username;
67  std::string shell;
68};
69
70static std::optional<PasswdEntry> GetPassword(id_t uid) {
71#ifdef USE_GETPWUID
72  // getpwuid_r is missing from android-9
73  // The caller should provide some thread safety by making sure no one calls
74  // this function concurrently, because using getpwuid is ultimately not
75  // thread-safe as we don't know who else might be calling it.
76  if (auto *user_info_ptr = ::getpwuid(uid))
77    return PasswdEntry{user_info_ptr->pw_name, user_info_ptr->pw_shell};
78#else
79  struct passwd user_info;
80  struct passwd *user_info_ptr = &user_info;
81  char user_buffer[PATH_MAX];
82  size_t user_buffer_size = sizeof(user_buffer);
83  if (::getpwuid_r(uid, &user_info, user_buffer, user_buffer_size,
84                   &user_info_ptr) == 0 &&
85      user_info_ptr) {
86    return PasswdEntry{user_info_ptr->pw_name, user_info_ptr->pw_shell};
87  }
88#endif
89  return std::nullopt;
90}
91
92std::optional<std::string> PosixUserIDResolver::DoGetUserName(id_t uid) {
93  if (std::optional<PasswdEntry> password = GetPassword(uid))
94    return password->username;
95  return std::nullopt;
96}
97
98std::optional<std::string> PosixUserIDResolver::DoGetGroupName(id_t gid) {
99#ifndef __ANDROID__
100  char group_buffer[PATH_MAX];
101  size_t group_buffer_size = sizeof(group_buffer);
102  struct group group_info;
103  struct group *group_info_ptr = &group_info;
104  // Try the threadsafe version first
105  if (::getgrgid_r(gid, &group_info, group_buffer, group_buffer_size,
106                   &group_info_ptr) == 0) {
107    if (group_info_ptr)
108      return std::string(group_info_ptr->gr_name);
109  } else {
110    // The threadsafe version isn't currently working for me on darwin, but the
111    // non-threadsafe version is, so I am calling it below.
112    group_info_ptr = ::getgrgid(gid);
113    if (group_info_ptr)
114      return std::string(group_info_ptr->gr_name);
115  }
116#endif
117  return std::nullopt;
118}
119
120static llvm::ManagedStatic<PosixUserIDResolver> g_user_id_resolver;
121
122UserIDResolver &HostInfoPosix::GetUserIDResolver() {
123  return *g_user_id_resolver;
124}
125
126uint32_t HostInfoPosix::GetUserID() { return getuid(); }
127
128uint32_t HostInfoPosix::GetGroupID() { return getgid(); }
129
130uint32_t HostInfoPosix::GetEffectiveUserID() { return geteuid(); }
131
132uint32_t HostInfoPosix::GetEffectiveGroupID() { return getegid(); }
133
134FileSpec HostInfoPosix::GetDefaultShell() {
135  if (const char *v = ::getenv("SHELL"))
136    return FileSpec(v);
137  if (std::optional<PasswdEntry> password = GetPassword(::geteuid()))
138    return FileSpec(password->shell);
139  return FileSpec("/bin/sh");
140}
141
142bool HostInfoPosix::ComputeSupportExeDirectory(FileSpec &file_spec) {
143  return ComputePathRelativeToLibrary(file_spec, "/bin");
144}
145
146bool HostInfoPosix::ComputeHeaderDirectory(FileSpec &file_spec) {
147  FileSpec temp_file("/opt/local/include/lldb");
148  file_spec.SetDirectory(temp_file.GetPath());
149  return true;
150}
151
152bool HostInfoPosix::GetEnvironmentVar(const std::string &var_name,
153                                      std::string &var) {
154  if (const char *pvar = ::getenv(var_name.c_str())) {
155    var = std::string(pvar);
156    return true;
157  }
158  return false;
159}
160