返回信息流最近学习《网络安全开发包详解》，运行第七章的程序时编译时能通过，但是获取不了想要的包，使用tcpdump能抓到通过网卡的包。同一个程序在其他机器上跑没问题，能补到包。我的系统是ubuntu11.10，那三个包pcap，libnet，libnids都装上了，百思不得其解，求大神指导啊。附个程序：
#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;
}
/*
=======================================================================================================================
下面的函数是对浏览器接收的数据进行分析
=======================================================================================================================
*/
void parse_client_data(char content[], int number)
{
char temp[1024];
char str1[1024];
char str2[1024];
char str3[1024];
int i;
int k;
int j;
char entity_content[1024];
if (content[0] != 'H' && content[1] != 'T' && content[2] != 'T' && content[3] != 'P')
{
printf("实体内容为（续）：\n");
for (i = 0; i < number; i++)
{
printf("%s", char_to_ascii(content[i]));
}
printf("\n");
}
else
{
for (i = 0; i < strlen(content); i++)
{
if (content[i] != '\n')
{
k++;
continue;
}
for (j = 0; j < k; j++)
temp[j] = content[j + i - k];
temp[j] = '\0';
if (strstr(temp, "HTTP"))
{
printf("状态行为：");
printf("%s\n", temp);
sscanf(temp, "%s %s %s", str1, str2);
printf("HTTP协议为:%s\n", str1);
printf("状态代码为:%s\n", str2);
}
if (strstr(temp, "Date"))
{
printf("当前的时间为（Date）:%s\n", temp + strlen("Date:"));
printf("%s\n", temp);
}
if (strstr(temp, "Server"))
{
printf("服务器为（Server）:%s\n", temp + strlen("Server:"));
printf("%s\n", temp);
}
if (strstr(temp, "Cache-Control"))
{
printf("缓存机制为（Cache-Control）:%s\n", temp + strlen("Cache-Control:"));
printf("%s\n", temp);
}
if (strstr(temp, "Expires"))
{
printf("资源期限为（Expires）:%s\n", temp + strlen("Expires:"));
printf("%s\n", temp);
}
if (strstr(temp, "Last-Modified"))
{
printf("最后一次修改的时间为（Last-Modified）:%s\n", temp + strlen("Last-Modified:"));
printf("%s\n", temp);
}
if (strstr(temp, "ETag"))
{
printf("Etag为（ETag）:%s\n", temp + strlen("Etag:"));
printf("%s\n", temp);
}
if (strstr(temp, "Accept-Ranges"))
{
printf("Accept-Ranges（Accept-Ranges）:%s\n", temp + strlen("Accept-Ranges:"));
printf("%s\n", temp);
}
if (strstr(temp, "Content-Length"))
{
printf("内容长度为（Content-Length）:%s\n", temp + strlen("Content-Length:"));
printf("%s\n", temp);
}
if (strstr(temp, "Connection"))
{
printf("连接状态为（Connection）:%s\n", temp + strlen("Connection:"));
printf("%s\n", temp);
}
if (strstr(temp, "Content-Type"))
{
printf("内容类型为（Content-Type）:%s\n", temp + strlen("Content-Type:"));
printf("%s\n", temp);
}
/* 获取实体内容 */
if ((content[i] == '\n') && (content[i + 1] == '\r'))
{
if (i + 3 == strlen(content))
{
printf("无实体内容\n");
break;
}
for (j = 0; j < number - i - 3; j++)
entity_content[j] = content[i + 3+j];
entity_content[j] = '\0';
printf("实体内容为：\n");
for (i = 0; i < j; i++)
{
printf("%s", char_to_ascii(entity_content[i]));
}
printf("\n");
break;
}
k = 0;
}
}
}
/*
=======================================================================================================================
下面的函数是对WEB服务器接收到的数据进行分析
=======================================================================================================================
*/
void parse_server_data(char content[], int number)
{
char temp[1024];
char str1[1024];
char str2[1024];
char str3[1024];
int i;
int k;
int j;
char entity_content[1024];
for (i = 0; i < strlen(content); i++)
{
if (content[i] != '\n')
{
k++;
continue;
}
for (j = 0; j < k; j++)
temp[j] = content[j + i - k];
temp[j] = '\0';
if (strstr(temp, "GET"))
{
printf("请求行为：");
printf("%s\n", temp);
sscanf(temp, "%s %s %s", str1, str2, str3);
printf("使用的命令为:%s\n", str1);
printf("获得的资源为:%s\n", str2);
printf("HTTP协议类型为:%s\n", str3);
}
if (strstr(temp, "Accept:"))
{
printf("接收的文件包括（Accept:）:%s\n", temp + strlen("Accept:"));
printf("%s\n", temp);
}
if (strstr(temp, "Referer"))
{
printf("转移地址为（Referer）:%s\n", temp + strlen("Referer:"));
printf("%s\n", temp);
}
if (strstr(temp, "Accept-Language"))
{
printf("使用的语言为（Accept-Language）:%s\n", temp + strlen("Accept-Language:"));
printf("%s\n", temp);
}
if (strstr(temp, "Accept-Encoding"))
{
printf("接收的编码方式为（Accept-Encoding）:%s\n", temp + strlen("Accept-Encoding:"));
printf("%s\n", temp);
}
if (strstr(temp, "If-Modified-Since"))
{
printf("上次修改时间为（If-Modified-Since）:%s\n", temp + strlen("If-Modified-Since:"));
printf("%s\n", temp);
}
if (strstr(temp, "If-None-Match"))
{
printf("If-None-Match为（If-Modified-Since）:%s\n", temp + strlen("If-None-Match:"));
printf("%s\n", temp);
}
if (strstr(temp, "User-Agent"))
{
printf("用户的浏览器信息为（User-Agent）:%s\n", temp + strlen("User-Agent:"));
printf("%s\n", temp);
}
if (strstr(temp, "Host"))
{
printf("访问的主机为（Host）:%s\n", temp + strlen("Host:"));
printf("%s\n", temp);
}
if (strstr(temp, "Connection"))
{
printf("连接状态为（Connection）:%s\n", temp + strlen("Connection:"));
printf("%s\n", temp);
}
if (strstr(temp, "Cookie"))
{
printf("Cookie为（Cookie）:%s\n", temp + strlen("Cookie:"));
printf("%s\n", temp);
}
/* 获取实体内容 */
if ((content[i] == '\n') && (content[i + 1] == '\r') && (content[i + 2] == '\n'))
{
if (i + 3 == strlen(content))
{
printf("无实体内容\n");
break;
}
for (j = 0; j < strlen(content) - i - 3; j++)
entity_content[j] = content[i + 3+j];
entity_content[j] = '\0';
printf("实体内容为：\n");
printf("%s", entity_content);
printf("\n");
break;
}
k = 0;
}
}
/*
=======================================================================================================================
下面是回调函数，实现对HTTP协议的分析
=======================================================================================================================
*/
void http_protocol_callback(struct tcp_stream *tcp_http_connection, void **param)
{
char address_content[1024];
char content[65535];
char content_urgent[65535];
struct tuple4 ip_and_port = tcp_http_connection->addr;
strcpy(address_content, inet_ntoa(*((struct in_addr*) &(ip_and_port.saddr))));
sprintf(address_content + strlen(address_content), " : %i", ip_and_port.source);
strcat(address_content, " <----> ");
strcat(address_content, inet_ntoa(*((struct in_addr*) &(ip_and_port.daddr))));
sprintf(address_content + strlen(address_content), " : %i", ip_and_port.dest);
strcat(address_content, "\n");
if (tcp_http_connection->nids_state == NIDS_JUST_EST)
{
if (tcp_http_connection->addr.dest != 80)
/* 只捕获HTTP协议数据包 */
{
return ;
}
tcp_http_connection->client.collect++; /* 浏览器接收数据 */
tcp_http_connection->server.collect++; /* WEB服务器端接收数据 */
printf("\n\n\n==============================================\n");
printf("%s 建立连接...\n", address_content);
return ;
}
if (tcp_http_connection->nids_state == NIDS_CLOSE)
{
printf("--------------------------------\n");
printf("%s连接正常关闭...\n", address_content);
/* 连接正常关闭 */
return ;
}
if (tcp_http_connection->nids_state == NIDS_RESET)
{
printf("--------------------------------\n");
printf("%s连接被RST关闭...\n", address_content);
/* 连接被RST关闭 */
return ;
}
if (tcp_http_connection->nids_state == NIDS_DATA)
{
struct half_stream *hlf;
if (tcp_http_connection->client.count_new)
/* 浏览器接收数据 */
{
hlf = &tcp_http_connection->client;
/* hlft表示浏览器接收的数据 */
strcpy(address_content, inet_ntoa(*((struct in_addr*) &(ip_and_port.saddr))));
sprintf(address_content + strlen(address_content), ":%i", ip_and_port.source);
strcat(address_content, " <---- ");
strcat(address_content, inet_ntoa(*((struct in_addr*) &(ip_and_port.daddr))));
sprintf(address_content + strlen(address_content), ":%i", ip_and_port.dest);
strcat(address_content, "\n");
printf("\n");
printf("%s", address_content);
printf("浏览器接收数据...\n");
printf("\n");
memcpy(content, hlf->data, hlf->count_new);
content[hlf->count_new] = '\0';
parse_client_data(content, hlf->count_new);
/* 分析浏览器接收的数据 */
}
else
{
hlf = &tcp_http_connection->server;
/* hlf表示Web服务器的TCP连接端 */
strcpy(address_content, inet_ntoa(*((struct in_addr*) &(ip_and_port.saddr))));
sprintf(address_content + strlen(address_content), " : %i", ip_and_port.source);
strcat(address_content, " ----> ");
strcat(address_content, inet_ntoa(*((struct in_addr*) &(ip_and_port.daddr))));
sprintf(address_content + strlen(address_content), ":%i", ip_and_port.dest);
strcat(address_content, "\n");
printf("\n");
printf("%s", address_content);
printf("服务器接收数据...\n");
printf("\n");
memcpy(content, hlf->data, hlf->count_new);
content[hlf->count_new] = '\0';
parse_server_data(content, hlf->count_new);
/* 分析WEB服务器接收的数据 */
}
}
return ;
}
/*
=======================================================================================================================
主函数
=======================================================================================================================
*/
void main()
{
if (!nids_init())
/* Libnids初始化 */
{
printf("出现错误：%s\n", nids_errbuf);
exit(1);
}
nids_register_tcp(http_protocol_callback);
/* 注册回调函数 */
nids_run(); /* 进入循环捕获数据包状态 */
}
这是一条镜像帖。来源：北邮人论坛 / security / #34322同步于 2012/5/17
该镜像源已超过 30 天没有更新，可能在源站已被删除。
Security机器人发帖
请教libnids程序
leeso
2012/5/17镜像同步3 回复
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3 条回复
在比较低的ubuntu 版本运行没问题 ，在11.10，12.04都不行，求解啊
【 在 cherrug 的大作中提到: 】
: 试下把libnids源码里某个计算检验和的地方注释掉，没准管用
可以试下自己编译下libnids，tcp.c里的process_tcp下边有段代码是
if (my_tcp_check(this_tcphdr, iplen - 4 * this_iphdr->ip_hl,
this_iphdr->ip_src.s_addr, this_iphdr->ip_dst.s_addr)) {
nids_params.syslog(NIDS_WARN_TCP, NIDS_WARN_TCP_HDR, this_iphdr,
this_tcphdr);
return;
}
把这段代码注释掉试下，看是不是这里给return了
【 在 leeso 的大作中提到: 】
: 在比较低的ubuntu 版本运行没问题 ，在11.10，12.04都不行，求解啊