1 /*
2  * Copyright (C) 2018 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include "common/libs/utils/environment.h"
18 
19 #include <sys/utsname.h>
20 
21 #include <cstdio>
22 #include <cstdlib>
23 #include <memory>
24 #include <ostream>
25 #include <string>
26 
27 #include <android-base/logging.h>
28 #include <android-base/no_destructor.h>
29 #include <android-base/strings.h>
30 
31 #include "common/libs/utils/files.h"
32 
33 namespace cuttlefish {
34 
StringFromEnv(const std::string & varname,const std::string & defval)35 std::string StringFromEnv(const std::string& varname,
36                           const std::string& defval) {
37   const char* const valstr = getenv(varname.c_str());
38   if (!valstr) {
39     return defval;
40   }
41   return valstr;
42 }
43 
44 /** Returns e.g. aarch64, x86_64, etc */
HostArchStr()45 const std::string& HostArchStr() {
46   static android::base::NoDestructor<std::string> arch([] {
47     utsname buf;
48     CHECK_EQ(uname(&buf), 0) << strerror(errno);
49     return std::string(buf.machine);
50   }());
51   return *arch;
52 }
53 
HostArch()54 Arch HostArch() {
55   std::string arch_str = HostArchStr();
56   if (arch_str == "aarch64" || arch_str == "arm64") {
57     return Arch::Arm64;
58   } else if (arch_str == "arm") {
59     return Arch::Arm;
60   } else if (arch_str == "riscv64") {
61     return Arch::RiscV64;
62   } else if (arch_str == "x86_64") {
63     return Arch::X86_64;
64   } else if (arch_str.size() == 4 && arch_str[0] == 'i' && arch_str[2] == '8' &&
65              arch_str[3] == '6') {
66     return Arch::X86;
67   } else {
68     LOG(FATAL) << "Unknown host architecture: " << arch_str;
69     return Arch::X86;
70   }
71 }
72 
IsHostCompatible(Arch arch)73 bool IsHostCompatible(Arch arch) {
74   Arch host_arch = HostArch();
75   return arch == host_arch || (arch == Arch::Arm && host_arch == Arch::Arm64) ||
76          (arch == Arch::X86 && host_arch == Arch::X86_64);
77 }
78 
IsRunningInDocker()79 static bool IsRunningInDocker() {
80   // if /.dockerenv exists, it's inside a docker container
81   static std::string docker_env_path("/.dockerenv");
82   static bool ret =
83       FileExists(docker_env_path) || DirectoryExists(docker_env_path);
84   return ret;
85 }
86 
IsRunningInContainer()87 bool IsRunningInContainer() {
88   // TODO: add more if we support other containers than docker
89   return IsRunningInDocker();
90 }
91 
92 }  // namespace cuttlefish
93