my_list.c

一个使用raw socket 构造数据包的实例

/**********************************************************
* 版权所有 (C)2007, 深圳市中兴通讯股份有限公司。
*
* 文件名称：my_list.c
* 文件标识：
* 内容摘要： 转发表的处理函数
* 其它说明：
* 当前版本：
* 作    者：丁 鹏
* 完成日期：2007/12/11
*
* 修改记录1：   
*    修改日期： 
*    版 本 号：
*    修 改 人：                    
*    修改内容：
**********************************************************/

/***********************************************************
 *                      头文件                             *
***********************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <linux/if_ether.h>
#include <linux/if_packet.h>
#include <netinet/ip.h>
#include <sys/ioctl.h>
#include <net/if.h>
#define __FAVOR_BSD
#include <netinet/tcp.h>
#include <netinet/udp.h>
#undef __FAVOR_BSD
#include <netinet/in.h>
#include <errno.h>
#include <string.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <strings.h>
#include "packet_gen.h"
#include "my_list.h"



/***********************************************************
 *                     全局变量                            *
***********************************************************/ 
struct fib_rules  *g_fibTable;
struct fib_rules  *fibTableHead;


/***********************************************************
 *                     全局函数                            *
***********************************************************/
int rules_memcmp(const void * cs,const void * ct,size_t count);
void rules_print();
int fib_rules_init(void);
int fib_rules_destroy(void);
int fib_rules_length(void);
int fib_rules_insert(struct fib_key *pfib_key);
int fib_rules_remove(struct fib_key *pfib_key);
int rules_memcmp(const void * cs,const void * ct,size_t count);
int fib_rules_removeRule(struct  in_addr *pip_src);
FIB_RULE *rules_isExist(struct in_addr *ip_src);

/**********************************************************************
* 函数名称：fib_rules_init
* 功能描述：转发表初始化
* 输入参数：
* 输出参数：无
* 返 回 值：无
* 其它说明：无
* 修改日期      版本号  修改人      修改内容
* ---------------------------------------------------------------------
* 2007/12/11             丁鹏              创建
************************************************************************/
int fib_rules_init(void)
{
    fibTableHead = malloc(sizeof(struct fib_rules));
    if(fibTableHead == NULL)
    {
        printf("fib_rules_int: malloc fib memory err\n");
        return -1;
    }
    memset(fibTableHead, 0x00, sizeof(struct fib_rules));
    fibTableHead->next = fibTableHead->prev = NULL;
    return 1;
}

/**********************************************************************
* 函数名称：fib_rules_destroy
* 功能描述：转发表销毁
* 输入参数：
* 输出参数：无
* 返 回 值：无
* 其它说明：无
* 修改日期      版本号  修改人      修改内容
* ---------------------------------------------------------------------
* 2007/12/11             丁鹏              创建
************************************************************************/
int fib_rules_destroy(void)
{
    struct fib_rules    *pFibRule, *pNode = fibTableHead;
    struct  fib_address *pAddr, *pAddNode;
    int i=0;
    int j = 0;
    pNode = pNode->next;
    while(pNode != NULL)
    {
        pFibRule = pNode;
          /* find dst address */
        pAddr = pNode->pdstaddr;
        while(pAddr != NULL)
        {
            pAddNode = pAddr;
            pAddNode->next = NULL;
            free(pAddNode);
            pAddr = pAddr->next;
            i++;
            printf("i = %d\n" , i);
        }    
        
        pNode->pdstaddr  = NULL;
        free(pNode);
        pNode    = pFibRule->next;
        j++;
        printf("j = %d\n" , j);
    }
    free(fibTableHead);
    fibTableHead = NULL;
    return 1;
}


/**********************************************************************
* 函数名称：fib_rules_length
* 功能描述：取得转发表长度
* 输入参数：
* 输出参数：无
* 返 回 值：无
* 其它说明：无
* 修改日期      版本号  修改人      修改内容
* ---------------------------------------------------------------------
* 2007/12/11             丁鹏              创建
************************************************************************/
int fib_rules_length(void)
{
    unsigned int num = 0;
    struct fib_rules *pNode = fibTableHead;
     
    while(pNode != NULL)
    {
        num ++;
        pNode = pNode->next;
    }
    
    return num;
}

/**********************************************************************
* 函数名称：fib_rules_insert
* 功能描述：在转发表中插入一个规则
* 输入参数：pfib_key  规则关键字
* 输出参数：无
* 返 回 值：无
* 其它说明：转发表 转发项中根据src 源ip地址确定转发策略
            转发策略有 转发给外网
                            1. 转发到一个外网口
                            2. 转发到多个外网口
                       转发给内网
                            1. 转发到一个内网口
                            2. 转发到一个内网口
* 修改日期      版本号  修改人      修改内容
* ---------------------------------------------------------------------
* 2007/12/11             丁鹏              创建
************************************************************************/
int fib_rules_insert(struct fib_key *pfib_key)
{  
    struct fib_rules *pNode = fibTableHead;
     struct fib_rules *pTail = fibTableHead;
    
    struct fib_rules *new_rules;
    struct fib_address *fib_addr = NULL;
    struct fib_address *fib_addr_next;
    struct fib_address *new_addr;

    unsigned char *key;
    unsigned char *rule_key;
    int            keylen;
    /*链表头为空,说明链表还没有初始化*/
    
    if (fibTableHead == NULL)
    {
        printf("error! fibtable has not been inited! \n");
        fib_rules_init();
    }    
    
    /* 第一个链表元素 */
    /* 第一次创建 */
    if(fibTableHead->next == NULL)
    {
        printf("the fist creat----\n");
        /* 在链表尾部插入 */
        new_rules = (struct fib_rules *)malloc(sizeof(struct fib_rules));
        if(new_rules == NULL)
        {
            printf("fib_rules_insert: malloc the fib_rules err\n");
            return 0;
        }
        new_addr = (struct fib_address *)malloc(sizeof(struct fib_address));
        if(new_addr == NULL)
        {
            printf("fib_rules_insert: malloc the fib_address err\n");
            free(new_rules);
            return 0;
        }
        
        pTail->next = new_rules;
        
        new_rules->direction = pfib_key->direction;
      
   
        memcpy((unsigned char *)&new_rules->ip_src, (unsigned char *)&pfib_key->ip_src, sizeof(struct in_addr));
        new_rules->pdstaddr = (struct fib_address *)new_addr;
        new_rules->next = NULL;
        new_rules->prev = pTail;
        
        if (pfib_key->direction == FIB_EXTERNEL_NETWORK)
        {
            memcpy(&new_addr->ip_dst, &pfib_key->ip_dst, sizeof(struct fib_address));  
        }
        else if(pfib_key->direction == FIB_INTERNEL_NETWORK)
        {
            memcpy(&new_addr->chipnum, &pfib_key->chipnum, sizeof(int));
        }
         
        new_addr->next = NULL;
        new_addr->prev = new_addr;
        new_rules->pdstaddr = new_addr;
        printf("fib_rules_insert: insert a new rule\n");
        return 1;
    }/*end if(fibTableHead->next == NULL) */
    
    pNode = fibTableHead->next;
    while (pNode != NULL)
    {
        printf("1----\n");
        pTail = pNode;
      
        /* 遍历链表,判断是否有满足条件的节点,有则再判断添加的dst是否存在,若dst不存在,则只添加对应的dst */
        if (rules_memcmp(&pNode->ip_src, &pfib_key->ip_src, sizeof(struct in_addr)) == 0)
        { 
       
            printf("ip_src equal----\n");
            /* 从一个ip地址来的只能是转给外网或内网中的一种策略 */
            if(pNode->direction != pfib_key->direction)
            {
                printf("the fib rules's  direction is't equal to pfib_key's direction\n");
                return 0;
            }
                  
            /* 再比较dst */
            printf("direction FIB_EXTERNEL_NETWORK----\n");
            fib_addr_next = pNode->pdstaddr;
            while(fib_addr_next != NULL)
            {
                printf("fib addr != null---\n");
                fib_addr = fib_addr_next;
      
                if (pNode->direction == FIB_EXTERNEL_NETWORK)
                {
                    rule_key = (unsigned char *)&fib_addr->ip_dst;
                    key      = (unsigned char *)&pfib_key->ip_dst;
                    keylen   = sizeof(struct in_addr);
                    /* 再比较dst */
                    printf("direction FIB_INTERNEL_NETWORK----\n");
                }
                else if(pNode->direction == FIB_INTERNEL_NETWORK)
                {
                    rule_key = (unsigned char *)&fib_addr->chipnum;
                    key      = (unsigned char *)&pfib_key->chipnum;
                    keylen   = sizeof(int);
                }/*end  if (pNode->direction == FIB_EXTERNEL_NETWORK) */
   
                if(rules_memcmp(rule_key, key, keylen) == 0)
                {
                    printf("the dst address exist\n");
                    return -1;
                }
                fib_addr_next =   fib_addr_next->next;
            } /* end while */
            new_addr = (struct fib_address *)malloc(sizeof(struct fib_address));
            if(new_addr == NULL)
            {
                printf("fib_rules_insert: malloc the fib_address err\n");
                return 0;
            }
                          
            if (pNode->direction == FIB_EXTERNEL_NETWORK)
            {
                memcpy(&new_addr->ip_dst, &pfib_key->ip_dst, sizeof(struct fib_address));  
            }
            else if(pNode->direction == FIB_INTERNEL_NETWORK)
            {
                memcpy(&new_addr->chipnum, &pfib_key->chipnum, sizeof(int));
            } /* end direction */
            new_addr->next  = NULL;
            /* 这种情况一般不会发生,pdstaddr is null----no fib_address, else has pdstaddr */
            if(fib_addr == NULL)
            {
                printf("unlikely pdstadd null");
                pNode->pdstaddr = new_addr; 
                new_addr->prev = new_addr;
                printf("fib_rules_insert: creat a new dst  list\n");
            }
            else
            {
                fib_addr->next = new_addr;
                new_addr->prev = fib_addr;
                printf("fib_rules_insert: insert a new dst into the list\n");
            } /*end fib_addr */
    
        } /* if (rules_memcmp(&pNode->ip_src, &pfib_key->ip_src, sizeof(struct in_addr)) == 0) */
        pNode = pNode->next;
    } /* end while */
    /* create a new rules */
    if(pNode == NULL)
    {
        printf("create a new rules----\n");
        /* 在链表尾部插入 */
        new_rules = (struct fib_rules *)malloc(sizeof(struct fib_rules));
        if(new_rules == NULL)
        {
            printf("fib_rules_insert: malloc the fib_rules err\n");
            return 0;
        }
        new_addr = (struct fib_address *)malloc(sizeof(struct fib_address));
        if(new_addr == NULL)
        {
            printf("fib_rules_insert: malloc the fib_address err\n");
            free(new_rules);
            return 0;
        }
        new_rules->direction = pfib_key->direction;