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
28 using namespace lldb_private;
29
GetPageSize()30 size_t HostInfoPosix::GetPageSize() { return ::getpagesize(); }
31
GetHostname(std::string & s)32 bool 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
GetOSKernelDescription()42 std::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
57 namespace {
58 class PosixUserIDResolver : public UserIDResolver {
59 protected:
60 std::optional<std::string> DoGetUserName(id_t uid) override;
61 std::optional<std::string> DoGetGroupName(id_t gid) override;
62 };
63 } // namespace
64
65 struct PasswdEntry {
66 std::string username;
67 std::string shell;
68 };
69
GetPassword(id_t uid)70 static 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
DoGetUserName(id_t uid)92 std::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
DoGetGroupName(id_t gid)98 std::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
120 static llvm::ManagedStatic<PosixUserIDResolver> g_user_id_resolver;
121
GetUserIDResolver()122 UserIDResolver &HostInfoPosix::GetUserIDResolver() {
123 return *g_user_id_resolver;
124 }
125
GetUserID()126 uint32_t HostInfoPosix::GetUserID() { return getuid(); }
127
GetGroupID()128 uint32_t HostInfoPosix::GetGroupID() { return getgid(); }
129
GetEffectiveUserID()130 uint32_t HostInfoPosix::GetEffectiveUserID() { return geteuid(); }
131
GetEffectiveGroupID()132 uint32_t HostInfoPosix::GetEffectiveGroupID() { return getegid(); }
133
GetDefaultShell()134 FileSpec 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
ComputeSupportExeDirectory(FileSpec & file_spec)142 bool HostInfoPosix::ComputeSupportExeDirectory(FileSpec &file_spec) {
143 return ComputePathRelativeToLibrary(file_spec, "/bin");
144 }
145
ComputeHeaderDirectory(FileSpec & file_spec)146 bool 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
GetEnvironmentVar(const std::string & var_name,std::string & var)152 bool 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