/*
 * 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,
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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,
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 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
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 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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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 GetHostByNameRTest(void)
{
    char host_file[] = "127.0.0.1 localhost\n";
    // 定义一个模拟的hosts文件内容，包含localhost映射到127.0.0.1的条目。
    char *pathList[] = {"/etc/hosts"};
    // 定义hosts文件的路径列表，这里只有一个路径指向系统的hosts文件。
    char *streamList[] = {static_cast<char *>(host_file)};
    // 定义模拟的hosts文件流列表，这里将模拟的hosts文件内容转换为char*类型。
    int streamLen[] = {sizeof(host_file)};
    // 定义模拟的hosts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hosts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。

    struct hostent addr, *result = NULL;
    // 定义hostent结构体变量addr，用于存储gethostbyname_r函数的结果。
    char buf[1024];
    // 定义一个足够大的缓冲区buf，用于gethostbyname_r函数。
    char buf1[1];
    // 定义一个非常小的缓冲区buf1，用于测试gethostbyname_r函数的边界条件。
    int err, ret;

    ret = gethostbyname_r("localhost", &addr, buf, sizeof buf, &result, &err);
    // 使用gethostbyname_r函数根据主机名"localhost"获取hostent结构体指针。
    ICUNIT_ASSERT_EQUAL(ret, 0, ret);
    // 断言返回值ret为0，表示gethostbyname_r函数调用成功。
    ICUNIT_ASSERT_NOT_EQUAL(result, NULL, -1);
    // 断言result不为空，即gethostbyname_r成功。
    ICUNIT_ASSERT_EQUAL(strcmp(result->h_name, "localhost"), 0, -1);
    // 断言返回的主机名与输入的主机名相同。
    ICUNIT_ASSERT_EQUAL(result->h_addrtype, AF_INET, result->h_addrtype);
    // 断言返回的地址类型为AF_INET。
    ICUNIT_ASSERT_NOT_EQUAL(result->h_length, 0, result->h_length);
    // 断言返回的地址长度不为0。

    ret = gethostbyname_r("127.0.0.1", &addr, buf, sizeof buf, &result, &err);
    // 使用gethostbyname_r函数根据IP地址字符串"127.0.0.1"获取hostent结构体指针。
    ICUNIT_ASSERT_EQUAL(ret, 0, ret);
    ICUNIT_ASSERT_NOT_EQUAL(result, NULL, -1);
    ICUNIT_ASSERT_EQUAL(strcmp(result->h_name, "127.0.0.1"), 0, -1);
    ICUNIT_ASSERT_EQUAL(result->h_addrtype, AF_INET, result->h_addrtype);
    ICUNIT_ASSERT_NOT_EQUAL(result->h_length, 0, result->h_length);

    ret = gethostbyname_r("127.0.0.1", &addr, buf1, sizeof buf1, &result, &err);
    // 测试gethostbyname_r函数的边界条件，传入的缓冲区太小。
    ICUNIT_ASSERT_NOT_EQUAL(ret, 0, ret);
    // 断言返回值ret不为0，表示gethostbyname_r函数调用失败。
    ret = gethostbyname_r("127.0.0.0.0", &addr, buf, sizeof buf, &result, &err);
    // 测试一个不存在的IP地址。
    ICUNIT_ASSERT_NOT_EQUAL(ret, 0, ret);
    // 断言返回值ret不为0，表示gethostbyname_r函数调用失败。
    ret = gethostbyname_r("lo", &addr, buf, sizeof buf, &result, &err);
    // 测试一个不存在的主机名。
    ICUNIT_ASSERT_NOT_EQUAL(ret, 0, ret);
    // 断言返回值ret不为0，表示gethostbyname_r函数调用失败。

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

void NetNetDbTest007(void)
{
    TEST_ADD_CASE(__FUNCTION__, GetHostByNameRTest, TEST_POSIX, TEST_TCP, TEST_LEVEL0, TEST_FUNCTION);
}
// 定义测试用例，将GetHostByNameRTest函数注册为一个测试案例。