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HostInfoPosix.cpp
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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
10#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 <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
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
123 return *g_user_id_resolver;
124}
125
126uint32_t HostInfoPosix::GetUserID() { return getuid(); }
127
129
131
133
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
143 return ComputePathRelativeToLibrary(file_spec, "/bin");
144}
145
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}
static llvm::ManagedStatic< PosixUserIDResolver > g_user_id_resolver
static std::optional< PasswdEntry > GetPassword(id_t uid)
A file utility class.
Definition: FileSpec.h:56
void SetDirectory(ConstString directory)
Directory string set accessor.
Definition: FileSpec.cpp:334
size_t GetPath(char *path, size_t max_path_length, bool denormalize=true) const
Extract the full path to the file.
Definition: FileSpec.cpp:366
static bool ComputePathRelativeToLibrary(FileSpec &file_spec, llvm::StringRef dir)
static bool ComputeSupportExeDirectory(FileSpec &file_spec)
static bool GetHostname(std::string &s)
static std::optional< std::string > GetOSKernelDescription()
static FileSpec GetDefaultShell()
static uint32_t GetEffectiveUserID()
static bool GetEnvironmentVar(const std::string &var_name, std::string &var)
static uint32_t GetGroupID()
static uint32_t GetEffectiveGroupID()
static UserIDResolver & GetUserIDResolver()
static bool ComputeHeaderDirectory(FileSpec &file_spec)
An abstract interface for things that know how to map numeric user/group IDs into names.
A class that represents a running process on the host machine.
std::string shell
std::string username
#define PATH_MAX