/*
 * 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:
 *
 * 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
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
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 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
// 版权声明，说明该代码由华为技术有限公司所有，并规定了代码的使用和分发条件。

#include "lt_net_netdb.h"
// 包含一个头文件，可能包含了网络数据库函数的声明和定义。

static int GetHostByAddrRTest(void)
{
    // 定义一个静态函数，用于测试gethostbyaddr_r函数。
    struct in_addr ia;
    struct hostent addr, *result = NULL;
    char buf[1024];
    char buf1[1];
    int err, ret;
    int length = 4;

    // 定义了一些变量，包括用于存储IP地址的in_addr结构体，hostent结构体用于存储查询结果，以及其他辅助变量。
    ia.s_addr = inet_addr("127.0.0.1");
    // 将字符串形式的IP地址"127.0.0.1"转换为网络字节序的二进制形式，并存储在ia结构体中。
    ret = gethostbyaddr_r(&ia, sizeof ia, AF_INET, &addr, buf, sizeof buf, &result, &err);
    // 使用gethostbyaddr_r函数根据IP地址查询主机信息，并将结果存储在result指向的hostent结构体中。
    ICUNIT_ASSERT_EQUAL(ret, 0, ret);
    // 断言函数返回值应为0，表示成功。
    ICUNIT_ASSERT_NOT_EQUAL(result, NULL, -1);
    // 断言result不应为空，表示查询到了主机信息。
    ICUNIT_ASSERT_EQUAL(result->h_addrtype, AF_INET, result->h_addrtype);
    // 断言查询到的主机地址类型应为AF_INET（IPv4）。
    ICUNIT_ASSERT_STRING_EQUAL(result->h_name, "localhost", -1);
    // 断言查询到的主机名应为"localhost"。
    ICUNIT_ASSERT_EQUAL(result->h_length, length, -1);
    // 断言查询到的主机地址长度应为4（IPv4地址长度）。

    errno = 0;
    // 清空errno，用于检测接下来的函数调用是否设置了errno。
    ia.s_addr = inet_addr("127.0.0.0");
    // 将字符串形式的IP地址"127.0.0.0"转换为网络字节序的二进制形式，并存储在ia结构体中。
    ret = gethostbyaddr_r(&ia, sizeof ia, AF_INET, &addr, buf, sizeof buf, &result, &err);
    // 再次调用gethostbyaddr_r函数，但这次传入的是一个无效的IP地址。
    ICUNIT_ASSERT_EQUAL(errno, EINVAL, errno);
    // 断言errno应被设置为EINVAL，表示无效参数。

    ret = gethostbyaddr_r(&ia, sizeof ia, AF_INET, &addr, buf, sizeof buf, &result, &err);
    // 再次调用函数，但errno已经被之前的调用设置，这里检查是否保持不变。
    ICUNIT_ASSERT_EQUAL(errno, EINVAL, errno);
    // 断言errno仍然为EINVAL。

    ret = gethostbyaddr_r(&ia, sizeof ia, AF_INET, &addr, buf1, sizeof buf1, &result, &err);
    // 调用gethostbyaddr_r函数，但这次传入的缓冲区buf1大小不足以存储结果。
    ICUNIT_ASSERT_EQUAL(ret, ERANGE, ret);
    // 断言函数返回值应为ERANGE，表示缓冲区太小。

    return ICUNIT_SUCCESS;
    // 返回测试成功。
}

void NetNetDbTest005(void)
{
    TEST_ADD_CASE(__FUNCTION__, GetHostByAddrRTest, TEST_POSIX, TEST_TCP, TEST_LEVEL0, TEST_FUNCTION);
    // 将当前测试函数添加到测试用例中，指定测试类型、协议、级别和函数。
}