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 <pwd.h>
23 #include <sys/types.h>
24 #include <sys/utsname.h>
25 #include <unistd.h>
26
27 using namespace lldb_private;
28
GetPageSize()29 size_t HostInfoPosix::GetPageSize() { return ::getpagesize(); }
30
GetHostname(std::string & s)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 s.assign(hostname);
36 return true;
37 }
38 return false;
39 }
40
GetOSKernelDescription()41 llvm::Optional<std::string> HostInfoPosix::GetOSKernelDescription() {
42 struct utsname un;
43 if (uname(&un) < 0)
44 return llvm::None;
45
46 return std::string(un.version);
47 }
48
49 #ifdef __ANDROID__
50 #include <android/api-level.h>
51 #endif
52 #if defined(__ANDROID_API__) && __ANDROID_API__ < 21
53 #define USE_GETPWUID
54 #endif
55
56 namespace {
57 class PosixUserIDResolver : public UserIDResolver {
58 protected:
59 llvm::Optional<std::string> DoGetUserName(id_t uid) override;
60 llvm::Optional<std::string> DoGetGroupName(id_t gid) override;
61 };
62 } // namespace
63
64 struct PasswdEntry {
65 std::string username;
66 std::string shell;
67 };
68
GetPassword(id_t uid)69 static llvm::Optional<PasswdEntry> GetPassword(id_t uid) {
70 #ifdef USE_GETPWUID
71 // getpwuid_r is missing from android-9
72 // The caller should provide some thread safety by making sure no one calls
73 // this function concurrently, because using getpwuid is ultimately not
74 // thread-safe as we don't know who else might be calling it.
75 if (auto *user_info_ptr = ::getpwuid(uid))
76 return PasswdEntry{user_info_ptr->pw_name, user_info_ptr->pw_shell};
77 #else
78 struct passwd user_info;
79 struct passwd *user_info_ptr = &user_info;
80 char user_buffer[PATH_MAX];
81 size_t user_buffer_size = sizeof(user_buffer);
82 if (::getpwuid_r(uid, &user_info, user_buffer, user_buffer_size,
83 &user_info_ptr) == 0 &&
84 user_info_ptr) {
85 return PasswdEntry{user_info_ptr->pw_name, user_info_ptr->pw_shell};
86 }
87 #endif
88 return llvm::None;
89 }
90
DoGetUserName(id_t uid)91 llvm::Optional<std::string> PosixUserIDResolver::DoGetUserName(id_t uid) {
92 if (llvm::Optional<PasswdEntry> password = GetPassword(uid))
93 return password->username;
94 return llvm::None;
95 }
96
DoGetGroupName(id_t gid)97 llvm::Optional<std::string> PosixUserIDResolver::DoGetGroupName(id_t gid) {
98 #ifndef __ANDROID__
99 char group_buffer[PATH_MAX];
100 size_t group_buffer_size = sizeof(group_buffer);
101 struct group group_info;
102 struct group *group_info_ptr = &group_info;
103 // Try the threadsafe version first
104 if (::getgrgid_r(gid, &group_info, group_buffer, group_buffer_size,
105 &group_info_ptr) == 0) {
106 if (group_info_ptr)
107 return std::string(group_info_ptr->gr_name);
108 } else {
109 // The threadsafe version isn't currently working for me on darwin, but the
110 // non-threadsafe version is, so I am calling it below.
111 group_info_ptr = ::getgrgid(gid);
112 if (group_info_ptr)
113 return std::string(group_info_ptr->gr_name);
114 }
115 #endif
116 return llvm::None;
117 }
118
119 static llvm::ManagedStatic<PosixUserIDResolver> g_user_id_resolver;
120
GetUserIDResolver()121 UserIDResolver &HostInfoPosix::GetUserIDResolver() {
122 return *g_user_id_resolver;
123 }
124
GetUserID()125 uint32_t HostInfoPosix::GetUserID() { return getuid(); }
126
GetGroupID()127 uint32_t HostInfoPosix::GetGroupID() { return getgid(); }
128
GetEffectiveUserID()129 uint32_t HostInfoPosix::GetEffectiveUserID() { return geteuid(); }
130
GetEffectiveGroupID()131 uint32_t HostInfoPosix::GetEffectiveGroupID() { return getegid(); }
132
GetDefaultShell()133 FileSpec HostInfoPosix::GetDefaultShell() {
134 if (const char *v = ::getenv("SHELL"))
135 return FileSpec(v);
136 if (llvm::Optional<PasswdEntry> password = GetPassword(::geteuid()))
137 return FileSpec(password->shell);
138 return FileSpec("/bin/sh");
139 }
140
ComputeSupportExeDirectory(FileSpec & file_spec)141 bool HostInfoPosix::ComputeSupportExeDirectory(FileSpec &file_spec) {
142 return ComputePathRelativeToLibrary(file_spec, "/bin");
143 }
144
ComputeHeaderDirectory(FileSpec & file_spec)145 bool HostInfoPosix::ComputeHeaderDirectory(FileSpec &file_spec) {
146 FileSpec temp_file("/opt/local/include/lldb");
147 file_spec.GetDirectory().SetCString(temp_file.GetPath().c_str());
148 return true;
149 }
150
GetEnvironmentVar(const std::string & var_name,std::string & var)151 bool HostInfoPosix::GetEnvironmentVar(const std::string &var_name,
152 std::string &var) {
153 if (const char *pvar = ::getenv(var_name.c_str())) {
154 var = std::string(pvar);
155 return true;
156 }
157 return false;
158 }
159