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 <procpartition/procpartition.h>
18
19 #include <android-base/file.h>
20
21 namespace android {
22 namespace procpartition {
23
operator <<(std::ostream & os,Partition p)24 std::ostream& operator<<(std::ostream& os, Partition p) {
25 switch (p) {
26 case Partition::SYSTEM: return os << "system";
27 case Partition::VENDOR: return os << "vendor";
28 case Partition::ODM: return os << "odm";
29 case Partition::UNKNOWN: // fallthrough
30 default:
31 return os << "(unknown)";
32 }
33 }
34
getExe(pid_t pid)35 std::string getExe(pid_t pid) {
36 std::string exe;
37 std::string real;
38 if (!android::base::Readlink("/proc/" + std::to_string(pid) + "/exe", &exe)) {
39 return "";
40 }
41 if (!android::base::Realpath(exe, &real)) {
42 return "";
43 }
44 return real;
45 }
46
getCmdline(pid_t pid)47 std::string getCmdline(pid_t pid) {
48 std::string content;
49 if (!android::base::ReadFileToString("/proc/" + std::to_string(pid) + "/cmdline", &content,
50 false /* follow symlinks */)) {
51 return "";
52 }
53 return std::string{content.c_str()};
54 }
55
parsePartition(const std::string & s)56 Partition parsePartition(const std::string& s) {
57 if (s == "system") {
58 return Partition::SYSTEM;
59 }
60 if (s == "vendor") {
61 return Partition::VENDOR;
62 }
63 if (s == "odm") {
64 return Partition::ODM;
65 }
66 return Partition::UNKNOWN;
67 }
68
getPartitionFromRealpath(const std::string & path)69 Partition getPartitionFromRealpath(const std::string& path) {
70 if (path == "/system/bin/app_process64" ||
71 path == "/system/bin/app_process32") {
72
73 return Partition::UNKNOWN; // cannot determine
74 }
75 size_t backslash = path.find_first_of('/', 1);
76 std::string partition = (backslash != std::string::npos) ? path.substr(1, backslash - 1) : path;
77
78 return parsePartition(partition);
79 }
80
getPartitionFromCmdline(pid_t pid)81 Partition getPartitionFromCmdline(pid_t pid) {
82 const auto& cmdline = getCmdline(pid);
83 if (cmdline == "system_server") {
84 return Partition::SYSTEM;
85 }
86 if (cmdline.empty() || cmdline.front() != '/') {
87 return Partition::UNKNOWN;
88 }
89 return getPartitionFromRealpath(cmdline);
90 }
91
getPartitionFromExe(pid_t pid)92 Partition getPartitionFromExe(pid_t pid) {
93 const auto& real = getExe(pid);
94 if (real.empty() || real.front() != '/') {
95 return Partition::UNKNOWN;
96 }
97 return getPartitionFromRealpath(real);
98 }
99
100
getPartition(pid_t pid)101 Partition getPartition(pid_t pid) {
102 Partition partition = getPartitionFromExe(pid);
103 if (partition == Partition::UNKNOWN) {
104 partition = getPartitionFromCmdline(pid);
105 }
106 return partition;
107 }
108
109 } // namespace procpartition
110 } // namespace android
111