Add a sample service for testing init.

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BinPackParameters: true

ColumnLimit:     100

ConstructorInitializerAllOnOneLineOrOnePerLine: false

IndentWidth:     4

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LOCAL_CLANG := true

LOCAL_CPPFLAGS := -Wall -Wextra -Werror

include $(BUILD_NATIVE_TEST)

# Include targets in subdirs.

# =========================================================

include $(call all-makefiles-under,$(LOCAL_PATH))

# Copyright (C) 2016 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.

LOCAL_PATH := $(call my-dir)

# Sample service for testing.

# =========================================================

include $(CLEAR_VARS)

LOCAL_MODULE := test_service

LOCAL_SRC_FILES := test_service.cpp

LOCAL_SHARED_LIBRARIES += libbase

LOCAL_INIT_RC := test_service.rc

include $(BUILD_EXECUTABLE)

# Sample service for testing

This is a sample service that can be used for testing init.

## Design

The service includes a `.rc` file that allows starting it from init.

    service test_service /system/bin/test_service CapAmb 0000000000003000

        class main

        user system

        group system

        capabilities NET_ADMIN NET_RAW

        disabled

        oneshot

The service accepts any even number of arguments on the command line

(i.e. any number of pairs of arguments.)

It will attempt to find the first element of each pair of arguments in

`/proc/self/status`, and attempt to exactly match the second element of the pair

to the relevant line of `proc/self/status`.

### Example

In the above case, the service will look for lines containing `CapAmb`:

    cat /proc/self/status

    ...

    CapAmb:	0000000000003000

And then attempt to exactly match the token after `:`, `0000000000003000`,

with the command-line argument.

If they match, the service exits successfully. If not, the service will exit

with an error.

## Usage

	mmma -j <jobs> system/core/init/testservice

	adb root

	adb remount

	adb sync

	adb reboot

	adb root

	adb shell start test_service

	adb logcat -b all -d | grep test_service

Look for an exit status of 0.

// Copyright (C) 2016 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.

#include <unistd.h>

#include <map>

#include <sstream>

#include <string>

#include <android-base/file.h>

#include <android-base/logging.h>

#include <android-base/strings.h>

void Usage(char* argv[]) {

    printf("Usage: %s <status field> <value> [<status field> <value>]*\n", argv[0]);

    printf("E.g.: $ %s Uid \"1000 1000 1000 1000\"\n", argv[0]);

}

int main(int argc, char* argv[]) {

    if (argc < 3) {

        Usage(argv);

        LOG(FATAL) << "no status field requested";

    }

    if (argc % 2 == 0) {

        // Since |argc| counts argv[0], if |argc| is odd, then the number of

        // command-line arguments is even.

        Usage(argv);

        LOG(FATAL) << "need even number of command-line arguments";

    }

    std::string status;

    bool res = android::base::ReadFileToString("/proc/self/status", &status, true);

    if (!res) {

        PLOG(FATAL) << "could not read /proc/self/status";

    }

    std::map<std::string, std::string> fields;

    std::vector<std::string> lines = android::base::Split(status, "\n");

    for (const auto& line : lines) {

        std::vector<std::string> tokens = android::base::Split(line, ":");

        if (tokens.size() >= 2) {

            std::string field = tokens[0];

            std::string value = android::base::Trim(tokens[1]);

            if (field.length() > 0) {

                fields[field] = value;

            }

        }

    }

    bool test_fails = false;

    size_t uargc = static_cast<size_t>(argc);  // |argc| >= 3.

    for (size_t i = 1; i < static_cast<size_t>(argc); i = i + 2) {

        std::string expected_value = argv[i + 1];

        auto f = fields.find(argv[i]);

        if (f != fields.end()) {

            if (f->second != expected_value) {

                LOG(ERROR) << "field '" << argv[i] << "' expected '" << expected_value

                           << "', actual '" << f->second << "'";

                test_fails = true;

            }

        } else {

            LOG(WARNING) << "could not find field '" << argv[i] << "'";

        }

    }

    return test_fails ? 1 : 0;

}