platform_system_core/init/util.h
Adam Langley ecc14a5958 init: Add option to listen on sockets before starting service.
Review note: Original change was a p-o-c by agl in
https://r.android.com/2094350 which I think is actually
production quality.  I'm just taking it over so that he doesn't
get spammed by any review comments as that's not a good use
of his time.

Needed for the hardware entropy daemon (see bug).

Original commit message:
If one needs to create a service that synchronously starts listening on
a socket then there are currently no good options.

The traditional UNIX solution is to have the service create the socket
and then daemonise. In this situation, init could start the service with
`exec_start` and yet not block forever because the service forks and
exits. However, when the initial child process exits, init kills the
daemon process:

> init: Killed 1 additional processes from a oneshot process group for
> service 'foo'. This is new behavior, previously child processes
> would not be killed in this case.

Next, there is a `socket` option for services and (although the
documentation didn't nail this down), the socket is created
synchronously by `start`. However, init doesn't call `listen` on the
socket so, until the service starts listening on the socket itself,
clients will get ECONNREFUSED.

This this change adds a `+listen` option, similar to `+passcred` which
allows a socket service to reliably handle connections.

Bug: 243933553
Test: Started prng_seeder from init using the new listen flag
Change-Id: I91b3b2b1fd38cc3d96e19e92b76c8e95788191d5
2022-09-12 15:16:35 +01:00

119 lines
4 KiB
C++

/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#pragma once
#include <sys/stat.h>
#include <sys/types.h>
#include <chrono>
#include <functional>
#include <string>
#include <vector>
#include <android-base/chrono_utils.h>
#include "fscrypt_init_extensions.h"
#include "result.h"
using android::base::boot_clock;
namespace android {
namespace init {
enum mount_mode {
MOUNT_MODE_DEFAULT = 0,
MOUNT_MODE_EARLY = 1,
MOUNT_MODE_LATE = 2,
};
static const char kColdBootDoneProp[] = "ro.cold_boot_done";
extern void (*trigger_shutdown)(const std::string& command);
Result<int> CreateSocket(const std::string& name, int type, bool passcred, bool should_listen,
mode_t perm, uid_t uid, gid_t gid, const std::string& socketcon);
Result<std::string> ReadFile(const std::string& path);
Result<void> WriteFile(const std::string& path, const std::string& content);
Result<uid_t> DecodeUid(const std::string& name);
bool mkdir_recursive(const std::string& pathname, mode_t mode);
int wait_for_file(const char *filename, std::chrono::nanoseconds timeout);
void ImportKernelCmdline(const std::function<void(const std::string&, const std::string&)>&);
void ImportBootconfig(const std::function<void(const std::string&, const std::string&)>&);
bool make_dir(const std::string& path, mode_t mode);
bool is_dir(const char* pathname);
Result<std::string> ExpandProps(const std::string& src);
// Returns the platform's Android DT directory as specified in the kernel cmdline.
// If the platform does not configure a custom DT path, returns the standard one (based in procfs).
const std::string& get_android_dt_dir();
// Reads or compares the content of device tree file under the platform's Android DT directory.
bool read_android_dt_file(const std::string& sub_path, std::string* dt_content);
bool is_android_dt_value_expected(const std::string& sub_path, const std::string& expected_content);
bool IsLegalPropertyName(const std::string& name);
Result<void> IsLegalPropertyValue(const std::string& name, const std::string& value);
std::string CleanDirPath(const std::string& path);
struct MkdirOptions {
std::string target;
mode_t mode;
uid_t uid;
gid_t gid;
FscryptAction fscrypt_action;
std::string ref_option;
};
Result<MkdirOptions> ParseMkdir(const std::vector<std::string>& args);
struct MountAllOptions {
std::vector<std::string> rc_paths;
std::string fstab_path;
mount_mode mode;
bool import_rc;
};
Result<MountAllOptions> ParseMountAll(const std::vector<std::string>& args);
Result<std::pair<int, std::vector<std::string>>> ParseRestorecon(
const std::vector<std::string>& args);
Result<std::string> ParseSwaponAll(const std::vector<std::string>& args);
Result<std::string> ParseUmountAll(const std::vector<std::string>& args);
void SetStdioToDevNull(char** argv);
void InitKernelLogging(char** argv);
bool IsRecoveryMode();
bool IsDefaultMountNamespaceReady();
void SetDefaultMountNamespaceReady();
bool IsMicrodroid();
bool Has32BitAbi();
std::string GetApexNameFromFileName(const std::string& path);
// Compare all files */path.#rc and */path.rc with the same path prefix.
// Keep the one with the highest # that doesn't exceed the system's SDK.
// (.rc == .0rc for ranking purposes)
std::vector<std::string> FilterVersionedConfigs(const std::vector<std::string>& configs,
int active_sdk);
} // namespace init
} // namespace android