Peter Qiu | 326b6cf | 2015-09-02 11:11:42 -0700 | [diff] [blame] | 1 | // |
| 2 | // Copyright (C) 2014 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 | // |
Peter Qiu | 5dd242d | 2014-10-14 12:23:21 -0700 | [diff] [blame] | 16 | |
| 17 | #include <vector> |
| 18 | |
| 19 | #include <base/bind.h> |
| 20 | #include <base/command_line.h> |
| 21 | #include <base/logging.h> |
Alex Vakulenko | 8d0c31b | 2015-10-13 09:14:24 -0700 | [diff] [blame] | 22 | #include <brillo/minijail/minijail.h> |
| 23 | #include <brillo/syslog_logging.h> |
Peter Qiu | 5dd242d | 2014-10-14 12:23:21 -0700 | [diff] [blame] | 24 | |
| 25 | #include "apmanager/daemon.h" |
| 26 | |
| 27 | using std::vector; |
| 28 | |
| 29 | namespace { |
| 30 | |
| 31 | namespace switches { |
| 32 | |
| 33 | // Don't daemon()ize; run in foreground. |
| 34 | const char kForeground[] = "foreground"; |
| 35 | // Flag that causes apmanager to show the help message and exit. |
| 36 | const char kHelp[] = "help"; |
| 37 | |
| 38 | // The help message shown if help flag is passed to the program. |
| 39 | const char kHelpMessage[] = "\n" |
| 40 | "Available Switches: \n" |
| 41 | " --foreground\n" |
| 42 | " Don\'t daemon()ize; run in foreground.\n"; |
| 43 | } // namespace switches |
| 44 | |
| 45 | } // namespace |
| 46 | |
| 47 | namespace { |
| 48 | |
Peter Qiu | 771952d | 2015-09-28 08:08:24 -0700 | [diff] [blame] | 49 | #if !defined(__ANDROID__) |
Peter Qiu | 5dd242d | 2014-10-14 12:23:21 -0700 | [diff] [blame] | 50 | const char kLoggerCommand[] = "/usr/bin/logger"; |
| 51 | const char kLoggerUser[] = "syslog"; |
Peter Qiu | 771952d | 2015-09-28 08:08:24 -0700 | [diff] [blame] | 52 | #endif // __ANDROID__ |
| 53 | |
Peter Qiu | 58676b6 | 2014-12-16 16:47:12 -0800 | [diff] [blame] | 54 | const char kSeccompFilePath[] = "/usr/share/policy/apmanager-seccomp.policy"; |
Peter Qiu | 5dd242d | 2014-10-14 12:23:21 -0700 | [diff] [blame] | 55 | |
| 56 | } // namespace |
| 57 | |
| 58 | // Always logs to the syslog and logs to stderr if |
| 59 | // we are running in the foreground. |
Alex Vakulenko | 8d0c31b | 2015-10-13 09:14:24 -0700 | [diff] [blame] | 60 | void SetupLogging(brillo::Minijail* minijail, |
Peter Qiu | 5dd242d | 2014-10-14 12:23:21 -0700 | [diff] [blame] | 61 | bool foreground, |
| 62 | const char* daemon_name) { |
| 63 | int log_flags = 0; |
Alex Vakulenko | 8d0c31b | 2015-10-13 09:14:24 -0700 | [diff] [blame] | 64 | log_flags |= brillo::kLogToSyslog; |
| 65 | log_flags |= brillo::kLogHeader; |
Peter Qiu | 5dd242d | 2014-10-14 12:23:21 -0700 | [diff] [blame] | 66 | if (foreground) { |
Alex Vakulenko | 8d0c31b | 2015-10-13 09:14:24 -0700 | [diff] [blame] | 67 | log_flags |= brillo::kLogToStderr; |
Peter Qiu | 5dd242d | 2014-10-14 12:23:21 -0700 | [diff] [blame] | 68 | } |
Alex Vakulenko | 8d0c31b | 2015-10-13 09:14:24 -0700 | [diff] [blame] | 69 | brillo::InitLog(log_flags); |
Peter Qiu | 5dd242d | 2014-10-14 12:23:21 -0700 | [diff] [blame] | 70 | |
Peter Qiu | 771952d | 2015-09-28 08:08:24 -0700 | [diff] [blame] | 71 | #if !defined(__ANDROID__) |
| 72 | // Logger utility doesn't exist on Android, so do not run it on Android. |
| 73 | // TODO(zqiu): add support to redirect stderr logs from child processes |
| 74 | // to Android logging facility. |
Peter Qiu | 5dd242d | 2014-10-14 12:23:21 -0700 | [diff] [blame] | 75 | if (!foreground) { |
| 76 | vector<char*> logger_command_line; |
| 77 | int logger_stdin_fd; |
| 78 | logger_command_line.push_back(const_cast<char*>(kLoggerCommand)); |
| 79 | logger_command_line.push_back(const_cast<char*>("--priority")); |
| 80 | logger_command_line.push_back(const_cast<char*>("daemon.err")); |
| 81 | logger_command_line.push_back(const_cast<char*>("--tag")); |
| 82 | logger_command_line.push_back(const_cast<char*>(daemon_name)); |
| 83 | logger_command_line.push_back(nullptr); |
| 84 | |
| 85 | struct minijail* jail = minijail->New(); |
| 86 | minijail->DropRoot(jail, kLoggerUser, kLoggerUser); |
| 87 | |
| 88 | if (!minijail->RunPipeAndDestroy(jail, logger_command_line, |
| 89 | nullptr, &logger_stdin_fd)) { |
| 90 | LOG(ERROR) << "Unable to spawn logger. " |
| 91 | << "Writes to stderr will be discarded."; |
| 92 | return; |
| 93 | } |
| 94 | |
| 95 | // Note that we don't set O_CLOEXEC here. This means that stderr |
| 96 | // from any child processes will, by default, be logged to syslog. |
| 97 | if (dup2(logger_stdin_fd, fileno(stderr)) != fileno(stderr)) { |
| 98 | LOG(ERROR) << "Failed to redirect stderr to syslog: " |
| 99 | << strerror(errno); |
| 100 | } |
| 101 | close(logger_stdin_fd); |
| 102 | } |
Peter Qiu | 771952d | 2015-09-28 08:08:24 -0700 | [diff] [blame] | 103 | #endif // __ANDROID__ |
Peter Qiu | 5dd242d | 2014-10-14 12:23:21 -0700 | [diff] [blame] | 104 | } |
| 105 | |
Alex Vakulenko | 8d0c31b | 2015-10-13 09:14:24 -0700 | [diff] [blame] | 106 | void DropPrivileges(brillo::Minijail* minijail) { |
Peter Qiu | 5dd242d | 2014-10-14 12:23:21 -0700 | [diff] [blame] | 107 | struct minijail* jail = minijail->New(); |
| 108 | minijail->DropRoot(jail, apmanager::Daemon::kAPManagerUserName, |
| 109 | apmanager::Daemon::kAPManagerGroupName); |
Peter Qiu | 58676b6 | 2014-12-16 16:47:12 -0800 | [diff] [blame] | 110 | // Permissions needed for the daemon and its child processes for managing |
| 111 | // network interfaces and binding to network sockets. |
| 112 | minijail->UseCapabilities(jail, CAP_TO_MASK(CAP_NET_ADMIN) | |
| 113 | CAP_TO_MASK(CAP_NET_RAW) | |
| 114 | CAP_TO_MASK(CAP_NET_BIND_SERVICE)); |
| 115 | minijail->UseSeccompFilter(jail, kSeccompFilePath); |
Peter Qiu | 5dd242d | 2014-10-14 12:23:21 -0700 | [diff] [blame] | 116 | minijail_enter(jail); |
| 117 | minijail->Destroy(jail); |
| 118 | } |
| 119 | |
Alex Vakulenko | 7f267ab | 2015-04-02 14:31:10 -0700 | [diff] [blame] | 120 | void OnStartup(const char* daemon_name, base::CommandLine* cl) { |
Alex Vakulenko | 8d0c31b | 2015-10-13 09:14:24 -0700 | [diff] [blame] | 121 | brillo::Minijail* minijail = brillo::Minijail::GetInstance(); |
Peter Qiu | 5dd242d | 2014-10-14 12:23:21 -0700 | [diff] [blame] | 122 | SetupLogging(minijail, cl->HasSwitch(switches::kForeground), daemon_name); |
| 123 | |
| 124 | LOG(INFO) << __func__ << ": Dropping privileges"; |
| 125 | |
Peter Qiu | 56e03e7 | 2015-09-28 13:42:48 -0700 | [diff] [blame] | 126 | // TODO(zqiu): apmanager is currently started as the "system" user on Android, |
| 127 | // so there is no need to drop privileges to the "system" user again. |
| 128 | // Drop user privileges when we're running apmanager under a different |
| 129 | // user/group. |
| 130 | #if !defined(__ANDROID__) |
Peter Qiu | 5dd242d | 2014-10-14 12:23:21 -0700 | [diff] [blame] | 131 | // Now that the daemon has all the resources it needs to run, we can drop |
| 132 | // privileges further. |
Peter Qiu | 58676b6 | 2014-12-16 16:47:12 -0800 | [diff] [blame] | 133 | DropPrivileges(minijail); |
Peter Qiu | 56e03e7 | 2015-09-28 13:42:48 -0700 | [diff] [blame] | 134 | #endif // __ANDROID |
Peter Qiu | 5dd242d | 2014-10-14 12:23:21 -0700 | [diff] [blame] | 135 | } |
| 136 | |
| 137 | int main(int argc, char* argv[]) { |
Alex Vakulenko | 7f267ab | 2015-04-02 14:31:10 -0700 | [diff] [blame] | 138 | base::CommandLine::Init(argc, argv); |
| 139 | base::CommandLine* cl = base::CommandLine::ForCurrentProcess(); |
Peter Qiu | 5dd242d | 2014-10-14 12:23:21 -0700 | [diff] [blame] | 140 | |
| 141 | if (cl->HasSwitch(switches::kHelp)) { |
| 142 | LOG(INFO) << switches::kHelpMessage; |
| 143 | return 0; |
| 144 | } |
| 145 | |
Peter Qiu | 5dd242d | 2014-10-14 12:23:21 -0700 | [diff] [blame] | 146 | apmanager::Daemon daemon(base::Bind(&OnStartup, argv[0], cl)); |
| 147 | |
| 148 | daemon.Run(); |
| 149 | |
| 150 | return 0; |
| 151 | } |