ftp.c

网络完全开发包 书 所带的、光盘 里面有书上的源代码

#include "nids.h"
char ascii_string[10000];
char *char_to_ascii(char ch)
{
    char *string;
    ascii_string[0] = 0;
    string = ascii_string;
    if (isgraph(ch))
        *string++ = ch;
    else if (ch == ' ')
        *string++ = ch;
    else if (ch == '\n' || ch == '\r')
        *string++ = ch;
    else
        *string++ = '.';
    *string = 0;
    return ascii_string;
}
/*
=======================================================================================================================
下面是分析FTP协议的回调函数
=======================================================================================================================
 */
void ftp_protocol_callback(struct tcp_stream *ftp_connection, void **arg)
{
    int i;
    char address_string[1024];
    char content[65535];
    char content_urgent[65535];
    struct tuple4 ip_and_port = ftp_connection->addr;
    strcpy(address_string, inet_ntoa(*((struct in_addr*) &(ip_and_port.saddr))));
    sprintf(address_string + strlen(address_string), " : %i", ip_and_port.source);
    strcat(address_string, " <---> ");
    strcat(address_string, inet_ntoa(*((struct in_addr*) &(ip_and_port.daddr))));
    sprintf(address_string + strlen(address_string), " : %i", ip_and_port.dest);
    strcat(address_string, "\n");
    switch (ftp_connection->nids_state)
    {
        case NIDS_JUST_EST:
            if ((ftp_connection->addr.dest == 21) || (ftp_connection->addr.source == 20))
            {
                /* FTP客户端和FTP服务器端建立连接 */
                ftp_connection->client.collect++;
                /* FTP客户端接收数据 */
                ftp_connection->server.collect++;
                /* FTP服务器接收数据 */
                ftp_connection->server.collect_urg++;
                /* FTP服务器接收紧急数据 */
                ftp_connection->client.collect_urg++;
                /* FTP客户端接收紧急数据 */
                if (ftp_connection->addr.dest == 21)
                    printf("%s FTP客户端与FTP服务器建立控制连接\n", address_string);
                if (ftp_connection->addr.source == 20)
                    printf("%s FTP服务器与FTP客户端建立数据连接\n", address_string);
            }
            return ;
        case NIDS_CLOSE:
            /* FTP客户端与FTP服务器端连接正常关闭 */
            printf("--------------------------------\n");
            if (ftp_connection->addr.dest == 21)
                printf("%sFTP客户端与FTP服务器的控制连接正常关闭\n", address_string);
            if (ftp_connection->addr.source == 20)
                printf("%sFTP服务器与FTP客户端的数据连接正常关闭\n", address_string);
            return ;
        case NIDS_RESET:
            /* FTP客户端与FTP服务器端连接被RST关闭 */
            printf("--------------------------------\n");
            if (ftp_connection->addr.source == 20)
                printf("%sFTP服务器与FTP客户端的数据连接被RESET关闭\n", address_string);
            if (ftp_connection->addr.dest == 21)
                printf("%sFTP客户端与FTP服务器的控制连接被REST关闭\n", address_string);
            return ;
        case NIDS_DATA:
            {
                /* FTP协议有新的数据达到 */
                struct half_stream *hlf;
                if (ftp_connection->server.count_new_urg)
                {
                    /* FTP服务器接收到新的紧急数据 */
                    printf("--------------------------------\n");
                    strcpy(address_string, inet_ntoa(*((struct in_addr*) &(ip_and_port.saddr))));
                    sprintf(address_string + strlen(address_string), " : %i", ip_and_port.source);
                    strcat(address_string, " urgent---> ");
                    strcat(address_string, inet_ntoa(*((struct in_addr*) &(ip_and_port.daddr))));
                    sprintf(address_string + strlen(address_string), " : %i", ip_and_port.dest);
                    strcat(address_string, "\n");
                    address_string[strlen(address_string) + 1] = 0;
                    address_string[strlen(address_string)] = ftp_connection->server.urgdata;
                    printf("%s", address_string);
                    return ;
                }
                if (ftp_connection->client.count_new_urg)
                {
                    /* FTP客户端接收到新的紧急数据 */
                    printf("--------------------------------\n");
                    strcpy(address_string, inet_ntoa(*((struct in_addr*) &(ip_and_port.saddr))));
                    sprintf(address_string + strlen(address_string), " : %i", ip_and_port.source);
                    strcat(address_string, " <--- urgent ");
                    strcat(address_string, inet_ntoa(*((struct in_addr*) &(ip_and_port.daddr))));
                    sprintf(address_string + strlen(address_string), " : %i", ip_and_port.dest);
                    strcat(address_string, "\n");
                    address_string[strlen(address_string) + 1] = 0;
                    address_string[strlen(address_string)] = ftp_connection->client.urgdata;
                    printf("%s", address_string);
                    return ;
                }
                if (ftp_connection->client.count_new)
                {
                    /* FTP客户端接收到新的数据 */
                    hlf = &ftp_connection->client;
                    strcpy(address_string, inet_ntoa(*((struct in_addr*) &(ip_and_port.saddr))));
                    sprintf(address_string + strlen(address_string), ":%i", ip_and_port.source);
                    strcat(address_string, " <--- ");
                    strcat(address_string, inet_ntoa(*((struct in_addr*) &(ip_and_port.daddr))));
                    sprintf(address_string + strlen(address_string), ":%i", ip_and_port.dest);
                    strcat(address_string, "\n");
                    printf("--------------------------------\n");
                    printf("%s", address_string);
                    /* 输出FTP客户端接收到的新的数据 */
                    memcpy(content, hlf->data, hlf->count_new);
                    content[hlf->count_new] = '\0';
                    if (ftp_connection->addr.source == 20)
                    {
                        printf("传输的数据为:\n");
                        for (i = 0; i < hlf->count_new; i++)
                        {
                            printf("%s", char_to_ascii(content[i]));
                        }
                        printf("\n");
                    }
                    else
                    {
                        if (content[0] == '1' || content[0] == '2' || content[0] == '3' || content[0] == '4' || content[0] == '5')
                            printf("FTP服务器响应状态代码为：%c%c%c\n", content[0], content[1], content[2]);
                        if (strncmp(content, "220", 3) == 0)
                            printf("新连接的用户的服务已经准备就绪\n");
                        if (strncmp(content, "110", 3) == 0)
                            printf("启动标记应答\n");
                        if (strncmp(content, "120", 3) == 0)
                            printf("表示 服务在nnn分钟内可用\n");
                        if (strncmp(content, "125", 3) == 0)
                            printf("表示数据连接已打开，准备传送\n");
                        if (strncmp(content, "150", 3) == 0)
                            printf("表示文件状态正确，正在打开数据连接\n");
                        if (strncmp(content, "200", 3) == 0)
                            printf("表示命令正常执行\n");