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
GetPageSize()28 size_t HostInfoPosix::GetPageSize() { return ::getpagesize(); }
29
GetHostname(std::string & s)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
GetPassword(id_t uid)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
DoGetUserName(id_t uid)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
DoGetGroupName(id_t gid)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
GetUserIDResolver()112 UserIDResolver &HostInfoPosix::GetUserIDResolver() {
113 return *g_user_id_resolver;
114 }
115
GetUserID()116 uint32_t HostInfoPosix::GetUserID() { return getuid(); }
117
GetGroupID()118 uint32_t HostInfoPosix::GetGroupID() { return getgid(); }
119
GetEffectiveUserID()120 uint32_t HostInfoPosix::GetEffectiveUserID() { return geteuid(); }
121
GetEffectiveGroupID()122 uint32_t HostInfoPosix::GetEffectiveGroupID() { return getegid(); }
123
GetDefaultShell()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
ComputeSupportExeDirectory(FileSpec & file_spec)132 bool HostInfoPosix::ComputeSupportExeDirectory(FileSpec &file_spec) {
133 return ComputePathRelativeToLibrary(file_spec, "/bin");
134 }
135
ComputeHeaderDirectory(FileSpec & file_spec)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
GetEnvironmentVar(const std::string & var_name,std::string & var)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 }
150