#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <fcntl.h>
#include <string.h>
#include <time.h>
#include <signal.h>
#include <sys/wait.h>
#include <curl/curl.h>

#define CENTOS_SYSTEM 1
#define DEBISN_SYSTEM 2
#define UNKNOWN_SYSTEM 3

#define BUFFER 1024
#define LONG_BUFFER 1024*100
#define TOP_IP 10
#define AWK " | awk -v num=%d '{a[$1]+=1;} END {for(i in a){if (a[i] >= num) {print i;}}}' "
#define GE_10 "grep -E \"^$(LC_ALL=\"C\" date \"+%h\").$(LC_ALL=\"C\" date \"+%d\")\" /var/log/auth.log | grep failure | grep rhost"
#define LE_10 "grep -E \"^$(LC_ALL=\"C\" date \"+%h\")..$(LC_ALL=\"C\" date | awk '{print $3}')\" /var/log/auth.log | grep failure | grep rhost"

#define CENTOS_GE_10 "grep -E \"^$(LC_ALL=\"C\" date \"+%h\").$(LC_ALL=\"C\" date \"+%d\")\" /var/log/secure | grep failure | grep rhost"
#define CENTOS_LE_10 "grep -E \"^$(LC_ALL=\"C\" date \"+%h\")..$(LC_ALL=\"C\" date | awk '{print $3}')\" /var/log/secure | grep failure | grep rhost"

#define IPTABLES "iptables -I INPUT -s %s -j DROP"
#define IPTABLES_CHECK "iptables -C INPUT -s %s -j DROP"

#define TIME 60

#define IS_DIND 1
#define PHONE "155659790"
#define DING_CURL "https://oapi.dingtalk.com/robot/send?access_token=7f069c672cb878987aa6772cca336740eece4ce36bde12b51b45e9f440e"

#define IS_MAIL 0

#define IS_QQMAIL 0
#define QQMAIL "qqMail -l smtp.qq.com -p 25 -f 1605227279 -e caczsjchvyibi -q NIUYULING -r 1605227279@QQ.COM -n NIUYULING -s \"System ban IP\" -t \"%s\""

// 存储公网IP
char public_ip[BUFFER];

// 检测系统
int check_system()
{
    if (0 == access("/etc/debian_version", F_OK)) {
        return DEBISN_SYSTEM;
    } else if (0 == access("/etc/centos-release", F_OK)) {
        return CENTOS_SYSTEM;
    }

    return UNKNOWN_SYSTEM;
}

// 获取公网IP
char *get_public_ip(char *ip)
{
    FILE *fp;
    char buff[BUFFER];

    memset(buff, 0, BUFFER);
    if (NULL == (fp = popen("curl members.3322.org/dyndns/getip --silent", "r"))) {
        perror("popen curl");
    }

    while (fgets(buff, BUFFER, fp) != NULL) {
        buff[strlen(buff) - 1] = '\0';
    }

    if (NULL != fp)
        pclose(fp);

    return strcpy(ip, buff);
}

// 替换字符串
int strReplaceAll(char *str, char *sub, char *replace)
{
    if (NULL == str || NULL == sub || NULL == replace) {
        printf("strReplaceAll param error\n");
        return 1;
    }

    char *p = NULL;
    char *t = NULL;
    char *q = NULL;
    char *dst = NULL;
    char *src = NULL;

    int str_len = strlen(str);
    int sub_len = strlen(sub);
    int replace_len = strlen(replace);

    p = str;
    while ('\0' != *p) {
        t = str + str_len;
        q = strstr(str, sub);
        if (NULL == q)                      /* 没有子串了，那么直接返回吧 */
            break;

        src = q + sub_len;                  /* 源头, 原有sub后的一个字符 */
        dst = q + replace_len;              /* 目的，放完replace后的一个字符 */
        memcpy(dst, src, t - src);          /* 原有字符串后移，放出空间 */
        memcpy(q, replace, replace_len);    /* 将replace字符拷贝进来 */
        str_len = str_len + replace_len - sub_len;

        p = q + replace_len;                /* p 下一轮replace后的一个字符 */
    }

    str[str_len] = '\0';                    /* 通过'\0'表示结尾 */

    return 0;
}

// 钉钉告警
int dingding_warning(char *illegal_ip, char *public_ip)
{
    CURL *curl;
    CURLcode res;

    curl_global_init(CURL_GLOBAL_ALL);
    curl = curl_easy_init();
    if (curl == NULL) {
        return 1;
    }

    char jsonObj[BUFFER] = "{  \
            \"msgtype\": \"text\",  \
            \"text\": { \
                \"content\": \"Alert @PHONE 主机PUBLIC 非法主机IP被封禁！ Warning!\" \
            },  \
            \"at\": {   \
                \"atMobiles\": [\"PHONE\"], \
                \"isAtAll\": false  \
            }   \
        }";

    strReplaceAll(jsonObj, "IP", illegal_ip);
    strReplaceAll(jsonObj, "PHONE", PHONE);
    strReplaceAll(jsonObj, "PUBLIC", public_ip);
    printf("%s\n", jsonObj);

    struct curl_slist *headers = NULL;
    headers = curl_slist_append(headers, "Accept: application/json");
    headers = curl_slist_append(headers, "Content-Type: application/json");
    headers = curl_slist_append(headers, "charset: utf-8");

    curl_easy_setopt(curl, CURLOPT_URL, DING_CURL);
    curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0);
    curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0);
    curl_easy_setopt(curl, CURLOPT_POST, 1);
    curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
    curl_easy_setopt(curl, CURLOPT_POSTFIELDS, jsonObj);
    curl_easy_setopt(curl, CURLOPT_USERAGENT, "libcurl/0.1");

    res = curl_easy_perform(curl);

    curl_easy_cleanup(curl);
    curl_global_cleanup();

    return res;
}

// 邮件告警
int mail_warning(char *illegal_ip, char *public_ip)
{
    FILE *fp = NULL;
    char buff[BUFFER];
    char text[BUFFER] = "echo \"主机:HOST, 禁止IP访问!\" |";

    memset(buff, 0, BUFFER);
    strReplaceAll(text, "IP", illegal_ip);
    strReplaceAll(text, "HOST", public_ip);

    strcat(text, " mail -s \"System ban IP\" 1605227279@qq.com");

    if (NULL == (fp = popen(text, "r"))) {
        perror("popen text");
    }

    while (fgets(buff, BUFFER, fp) != NULL) {
        buff[strlen(buff) - 1] = '\0';
    }

    if (NULL != fp)
        pclose(fp);

    return 0;
}

// 第三方邮箱告警
int QQ_mail_warning(char *illegal_ip, char *public_ip)
{
    
    char string[BUFFER+(sizeof(QQMAIL))];
    char text[BUFFER] = "主机:HOST, 禁止IP访问!";
    
    strReplaceAll(text, "IP", illegal_ip);
    strReplaceAll(text, "HOST", public_ip);
    
    memset(string, 0, BUFFER+(sizeof(QQMAIL)));
    sprintf(string, QQMAIL, text);
    
    system(string);
    
    return 0;
}

// 封禁非法IP
int rule()
{
    FILE *fp, *fc;
    char p[2], splice_command[LONG_BUFFER], command[LONG_BUFFER], *temp, buffer[BUFFER], awk[BUFFER], iptables[BUFFER + (sizeof(IPTABLES))], iptables_check[BUFFER + (sizeof(IPTABLES))];

    time_t timep;
    struct tm *tp;
    time(&timep);
    tp = localtime(&timep);
    memset(splice_command, 0, LONG_BUFFER);
    memset(command, 0, LONG_BUFFER);
    memset(buffer, 0, BUFFER);
    memset(awk, 0, BUFFER);
    memset(iptables, 0, BUFFER+(sizeof(IPTABLES)));
    memset(iptables_check, 0, BUFFER+(sizeof(IPTABLES)));
    fp = NULL;
    fc = NULL;

    if (DEBISN_SYSTEM == check_system()) // Debian 系统规则
    {
        if (tp->tm_mday >= 10) {
            if ((fp = popen(GE_10, "r")) == NULL) {
                perror("GE_10");
                return 1;
            }
        } else {
            if ((fp = popen(LE_10, "r")) == NULL) {
                perror("LE_10");
                return 1;
            }
        }
    } else if (CENTOS_SYSTEM == check_system()) // Centos 7系统规则
    {
        if (tp->tm_mday >= 10) {
            if ((fp = popen(CENTOS_GE_10, "r")) == NULL) {
                perror("CENTOS_GE_10");
                return 1;
            }
        } else {
            if ((fp = popen(CENTOS_LE_10, "r")) == NULL) {
                perror("CENTOS_LE_10");
                return 1;
            }
        }

    } else {
        return UNKNOWN_SYSTEM;
    }

    while (fgets(buffer, BUFFER, fp) != NULL) {
        temp = strstr(buffer, "rhost");
        sscanf(temp, "rhost=%s", temp);
        if (atoi(strncpy(p, temp, 1)) > 0) {
            strcat(splice_command, temp);
            strcat(splice_command, "\n");
        }
    }
    printf("%s", splice_command); // 打印所有非法IP

    // 拼接命令
    sprintf(awk, AWK, TOP_IP);
    strcpy(command, "echo \"");
    strcat(command, splice_command);
    strcat(command, "\"");
    strcat(command, awk);


    if ((fp = popen(command, "r")) == NULL) // 执行命令
    {
        perror("popen command");
        return 1;
    }

    while (fgets(buffer, BUFFER, fp) != NULL)       // 执行命令后, 为空时就不会
    {

        buffer[strlen(buffer) - 1] = '\0';          // 去除回车
        sprintf(iptables, IPTABLES, buffer);
        sprintf(iptables_check, IPTABLES_CHECK, buffer);


        if (0 != system(iptables_check))            // 判断是否存在规则, 不存在时再添加规则
        {
            if (IS_DIND == 1)                       // 钉钉告警
            {
                dingding_warning(buffer, public_ip);
                sleep(3);
            }
            
            if (IS_MAIL == 1)                       // 邮件告警
            {
                mail_warning(buffer, public_ip);
                sleep(3);
            }
            
            if (IS_QQMAIL == 1)                       // 邮件告警
            {
                QQ_mail_warning(buffer, public_ip);
                sleep(3);
            }

            if ((fc = popen(iptables, "r")) == NULL) {
                perror("popen iptables");
                return 1;
            }
        }

    }

    if (fp != NULL)
        pclose(fp);

    if (fc != NULL)
        pclose(fc);

    return 0;
}

static void sig_child(int signo)
{
    pid_t pid;
    int stat;
    // 处理僵尸进程
    while ((pid = waitpid(-1, &stat, WNOHANG)) > 0) ;
    
    return;
}

int main(int argc, char *argv[], char **env)
{
    memset(public_ip, 0, BUFFER);
    get_public_ip(public_ip);
    


    signal(SIGCHLD, sig_child); // 创建捕捉子进程退出信号


    if (argv[1] != NULL && 0 == strcmp(argv[1], "-d"))
    {
        if (daemon(1, 1))       // 守护进程
        {
            perror("daemon");
            return -1;
        }

        while (1) {
            rule();

            sleep(TIME);
        }
    }
    else
    {
        rule();
    }


    return 0;
}