/*
 * Copyright (c) 2013-2019 Huawei Technologies Co., Ltd. All rights reserved.
 * Copyright (c) 2020-2021 Huawei Device Co., Ltd. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
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 * 1. Redistributions of source code must retain the above copyright notice, this list of
 * conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice, this list
 * of conditions and the following disclaimer in the documentation and/or other materials
 * provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its contributors may be used
 * to endorse or promote products derived from this software without specific prior written
 * permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
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 */


#include "lt_net_netdb.h"
// 引入头文件，可能包含了网络数据库相关的函数声明和宏定义。

static int GetServByPortTest(void)
{
    // refer to the `/etc/services' file.
    char serv_file[] = "ssh		22/tcp\n";
    // 定义一个模拟的services文件内容，包含ssh服务的条目。
    char *pathList[] = {"/etc/services"};
    // 定义services文件的路径列表，这里只有一个路径指向系统的services文件。
    char *streamList[] = {static_cast<char *>(serv_file)};
    // 定义模拟的services文件流列表，这里将模拟的services文件内容转换为char*类型。
    int streamLen[] = {sizeof(serv_file)};
    // 定义模拟的services文件流长度列表。
    const int file_number = 1;
    // 定义文件数量。
    int flag = PrepareFileEnv(pathList, streamList, streamLen, file_number);
    // 调用PrepareFileEnv函数准备文件环境，模拟services文件。
    if (flag != 0) {
        RecoveryFileEnv(pathList, file_number);
        return -1;
    }
    // 如果准备文件环境失败，则恢复原始文件环境并返回错误码。

    const int test_port_no = 22; // ssh port number is 22
    // 定义测试的端口号，这里是22，即SSH服务的标准端口号。
    struct servent *se1 = nullptr;
    // 定义servent结构体指针变量se1，初始化为nullptr。
    struct servent *se = getservbyport(htons(test_port_no), "tcp");
    // 使用getservbyport函数根据端口号和协议名（"tcp"）获取servent结构体指针。
    ICUNIT_ASSERT_NOT_EQUAL(se, NULL, -1);
    // 断言se不为空，即getservbyport成功。
    ICUNIT_ASSERT_STRING_EQUAL(se->s_name, "ssh", -1);
    // 断言返回的服务名称与"ssh"相同。
    ICUNIT_ASSERT_STRING_EQUAL(se->s_proto, "tcp", -1);
    // 断言返回的服务协议与"tcp"相同。
    ICUNIT_ASSERT_STRING_EQUAL(se->s_aliases[0], "ssh", -1);
    // 断言返回的服务别名与"ssh"相同。

    se1 = getservbyport(htons(test_port_no), "tp");
    // 尝试使用getservbyport函数根据端口号和错误的协议名（"tp"）获取servent结构体指针，预期失败。
    ICUNIT_ASSERT_EQUAL(se1, nullptr, -1);
    // 断言se1为空，即getservbyport失败。

    RecoveryFileEnv(pathList, file_number);
    // 恢复原始文件环境。
    return ICUNIT_SUCCESS;
    // 返回测试成功。
}

void NetNetDbTest011(void)
{
    TEST_ADD_CASE(__FUNCTION__, GetServByPortTest, TEST_POSIX, TEST_TCP, TEST_LEVEL0, TEST_FUNCTION);
}
// 定义测试用例，将GetServByPortTest函数注册为一个测试案例。