#include "conf.h"
#include "rhost.h"
#include "libiptc.h"

// 存储公网IP
char *public_ip;

struct MemoryStruct {
    char *memory;
    size_t size;
};

static size_t WriteMemoryCallback(void *contents, size_t size, size_t nmemb, void *userp)
{
    size_t realsize = size * nmemb;
    struct MemoryStruct *mem = (struct MemoryStruct *)userp;

    // 注意这里根据每次被调用获得的数据重新动态分配缓存区的大小
    char *ptr = realloc(mem->memory, mem->size + realsize + 1);
    if (ptr == NULL) {
        /* 内存不足！ */
        printf("not enough memory (realloc returned NULL)\n");
        return 0;
    }

    mem->memory = ptr;
    memcpy(&(mem->memory[mem->size]), contents, realsize);
    mem->size += realsize;
    mem->memory[mem->size] = 0;

    return realsize;
}

// 获取公网IP
static char *GET_PUBLIC_IP(char *URL)
{
    CURL *curl_handle;
    CURLcode res;

    struct MemoryStruct chunk;

    chunk.memory = malloc(1);   /* 将根据上述再分配的需要增长 */
    chunk.size = 0;             /* 此时没有数据 */

    curl_global_init(CURL_GLOBAL_ALL);

    /* 初始化curl会话 */
    curl_handle = curl_easy_init();

    /* 指定要获取的URL */
    curl_easy_setopt(curl_handle, CURLOPT_URL, URL);
    /* 将所有数据发送到此函数  */
    //对于同一次阻塞的curl_easy_perform而言，在写完获取的数据之前，会多次调用 WriteMemoryCallback
    curl_easy_setopt(curl_handle, CURLOPT_WRITEFUNCTION, WriteMemoryCallback);
    /* 将“chunk”结构传递给回调函数 */
    curl_easy_setopt(curl_handle, CURLOPT_WRITEDATA, (void *)&chunk);
    curl_easy_setopt(curl_handle, CURLOPT_USERAGENT, "libcurl-agent/1.0");
    //对于同一次阻塞的curl_easy_perform而言，在写完获取的数据之前，会多次调用 WriteMemoryCallback
    res = curl_easy_perform(curl_handle);


    if (res != CURLE_OK) {
        fprintf(stderr, "curl_easy_perform() failed: %s\n", curl_easy_strerror(res));
    } else {
        //printf("%lu bytes retrieved\n", (unsigned long)chunk.size);
        printf("%s", chunk.memory);
    }

    curl_easy_cleanup(curl_handle);
    curl_global_cleanup();

    return chunk.memory;
}

// 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;
}

// 钉钉告警
int dingding_warning(char *illegal_ip, char *public_ip, conf *conf)
{
    FILE *fp;
    char temp[64];
    char jsonObj[BUFFER];
    
    
    memset(jsonObj, 0, BUFFER);
    memset(temp, 0, 64);
    strcpy(temp, public_ip);
    temp[strlen(public_ip)-1] = '\0';
    
    if ((fp = fopen("libcurl_ding.log", "wt+")) == NULL){
        return 1;
    }
    
    CURL *curl;
    CURLcode res;

    curl_global_init(CURL_GLOBAL_ALL);
    curl = curl_easy_init();
    if (curl == NULL) {
        return 1;
    }
    
    #define JSIN "{  \
            \"msgtype\": \"text\",  \
            \"text\": { \
                \"content\": \"Alert @%s 服务器地址:%s，封禁非法入侵主机:%s\" \
            },  \
            \"at\": {   \
                \"atMobiles\": [\"%s\"], \
                \"isAtAll\": false  \
            }   \
        }"

    sprintf(jsonObj, JSIN, conf->PHONE, temp, illegal_ip, conf->PHONE);
    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, conf->DING_WEBHOOK);
    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");
    curl_easy_setopt(curl, CURLOPT_WRITEDATA, fp);
    
    res = curl_easy_perform(curl);

    curl_easy_cleanup(curl);
    curl_global_cleanup();
    fclose(fp);
    
    return res;
}

// 邮件告警
int mail_warning(char *illegal_ip, char *public_ip)
{
    FILE *fp = NULL;
    char buff[BUFFER];
    char text[BUFFER];
    char temp[64];
    
    
    memset(buff, 0, BUFFER);
    memset(text, 0, BUFFER);
    memset(temp, 0, 64);
    
    strcpy(temp, public_ip);
    temp[strlen(public_ip)-1] = '\0';

    sprintf(text, "主机:%s, 禁止%s访问", temp, illegal_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, conf *conf)
{
    char string[BUFFER+(sizeof(QQMAIL))];
    char text[BUFFER];
    char temp[32];

    memset(string, 0, BUFFER+(sizeof(QQMAIL)));
    memset(text, 0, BUFFER);
    memset(temp, 0, 32);
    
    
    strcpy(temp, public_ip);
    temp[strlen(public_ip)-1] = '\0';
    
    sprintf(text, "主机:%s, 禁止%s访问", temp, illegal_ip);
    
    sprintf(string, QQMAIL, conf->RECV_MAIL, text);
    printf("%s\n", string);
    system(string);
    
    return 0;
}

// 封禁非法IP
int rule(conf *conf)
{
    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_CHECK))];
    char p[2], splice_command[LONG_BUFFER], command[LONG_BUFFER], *temp, buffer[BUFFER], awk[BUFFER];

    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_CHECK)));
    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, conf->REFUSE_NUMBER);
    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))                    // 调用iptables命令判断是否存在规则, 不存在时再添加规则
        if (0 != show_all_rule(buffer))                     // libiptc库判断
        {
            if (conf->IS_DING_WEBHOOK == 1)                 // 钉钉告警
            {
                dingding_warning(buffer, public_ip, conf);
                sleep(3);
            }
            
            if (conf->IS_MAIL == 1)                         // 邮件告警
            {
                mail_warning(buffer, public_ip);
                sleep(3);
            }
            
            if (conf->IS_QQMAIL == 1)                       // 邮件告警
            {
                QQ_mail_warning(buffer, public_ip, conf);
                sleep(3);
            }
            
            /*
            // 调用命令下发规则
            if ((fc = popen(iptables, "r")) == NULL) {
                perror("popen iptables");
                return 1;
            }
            */
            
            // libiptc 库插入规则 iptables -t filter -A INPUT -p tcp -s xxxx -j DROP
            unsigned int destIp;
            inet_pton(AF_INET, buffer, &destIp);
            iptc_add_rule("filter", "INPUT", IPPROTO_TCP, NULL, NULL, 0, destIp, NULL, NULL, "DROP", NULL, 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)
{
    conf *conf = (struct CONF *)malloc(sizeof(struct CONF));
    read_conf("rhost.conf", conf);
    //ptintf_conf(conf);
    
    
    // 新版本获取公网IP
    public_ip = GET_PUBLIC_IP("http://ip.sb");
    
    //printf("%s", public_ip);
    

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

    if (0 == strcmp(conf->DAEMON, "on"))
    {
        goto goto_daemon;
    }

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

        while (1) {
            rule(conf);

            sleep(conf->TIME);
        }
    }
    else
    {
        rule(conf);
    }


    free_conf(conf);
    free(conf);
    free(public_ip);
    
    return 0;
}