vxworks下抓取udp包

最近因为工作需要，要在vxworks的应用层实现对IP包的截取。因为我们用到的是vxworks5.4版本，所以可以使用ipFilterHookAddr函数，通过添加钩子函数实现。

/*************************************************************
 *function : 将16进制IP地址转变成十进制IP地址串
 *paramters:
 *author : rex
 *date : 2010-10-25
 *modify :
**************************************************************/
void hex2ip(unsigned int ipaddr, char *ipbuf)
{
    char *ip;

    ip = (char *)&ipaddr;
    sprintf(ipbuf, "%d.%d.%d.%d", ip[0], ip[1], ip[2], ip[3]);
}

/*************************************************************
 *function : 处理钩子函数抓取的IP数据包
 *paramters:
         struct ifnet *pIf, /@ interface that received the packet @/
             struct mbuf **pPtrMbuf, /@ pointer to pointer to an mbuf chain @/
         struct ip **pPtrIpHdr, /@ pointer to pointer to IP header @/
         int ipHdrLen, /@ IP packet header length @/
 *author : rex
 *date : 2010-10-26
 *modify :
**************************************************************/
BOOL ipFilterHook(struct ifnet *pIf, struct mbuf **pPtrMbuf, struct ip **pPtrIpHdr, int ipHdrLen)
{
    struct ip *pIpHead;
    struct udphdr *pUdpHead;
    struct tcphdr *pTcpHead;
    char    srcIpaddr[17];
    char     dstIpaddr[17];
    char    str[1500];
    unsigned short    udpPacketLen;
    int     i;
    
    M_BLK_ID pMblk = *pPtrMbuf;
    pIpHead = (struct ip *)pMblk->mBlkHdr.mData;    

    /* output the src and des ip addr */
    hex2ip(pIpHead->ip_src.s_addr, srcIpaddr);
    hex2ip(pIpHead->ip_dst.s_addr, dstIpaddr);

    if (!strcmp(dstIpaddr, "255.255.255.255"))     /* 屏蔽广播包 */
        return (FALSE);

    printf("srcIp:%s\t dstIp:%s\r\n", srcIpaddr, dstIpaddr);    /* 打印IP包中源IP地址和目的IP地址 */
        
    switch(pIpHead->ip_p)
    {
    case IPPROTO_ICMP:
        printf("protocol icmp\r\n");
        break;
    case IPPROTO_TCP:
        pTcpHead = (struct tcphdr*)(pMblk->mBlkHdr.mData + ipHdrLen);
        printf("protocol tcp\r\n");    
        break;
    case IPPROTO_UDP:
        pUdpHead = (struct udphdr*)(pMblk->mBlkHdr.mData + ipHdrLen);
        udpPacketLen = ntohs(pUdpHead->uh_ulen);
        memcpy(str, ((char *)pMblk->mBlkHdr.mData + ipHdrLen + sizeof(struct udphdr)), udpPacketLen);
        printf("srcport:%u\t, dstport:%u\t, len:%u\r\n", ntohs(pUdpHead->uh_sport), ntohs(pUdpHead->uh_dport), udpPacketLen);
        for (i = 0; i < udpPacketLen; i++)        /* 打印udp数据包中的内容*/
        {
            printf("%2x", str[i]);
            if ( i%16 == 0)
                printf("\r\n");
        }
        printf("\r\n\r\n");
        break;
    default:
        printf("unknow protocol %d\r\n", pIpHead->ip_p);
        break;
    }

    return (FALSE);
}

/*************************************************************
 *function : 抓取网口收到的IP包
 *paramters:
 *author : rex
 *date : 2010-10-25
 *modify :
**************************************************************/
void catchPacketFunc()
{
    if (ipFilterHookAdd(ipFilterHook) == ERROR)
        perror("ipFilterHookAdd failed\r\n");
}