icmplib.c

vxworks的完整的源代码

    if (pCookie == NULL)
	goto icmpMaskGetError;


    for (ix = 0; ix < ICMP_MAX_SEND;  ix++)
	{
        if ((pMbuf = bcopy_to_mbufs ((u_char *) &icmpMsg, sizeof (icmpMsg),
				     0, pIf, NONE)) == NULL)
            goto icmpMaskGetError;

        if (dst == NULL)   			/* if broadcasting */
	    pMbuf->mBlkHdr.mFlags |= M_BCAST;


	/* send message */

        level = splnet ();
	result = (* pIf->if_output) ( (struct ifnet *)&pDrvCtrl->idr, pMbuf,
			             (struct sockaddr *)&dstAddr, NULL);
        splx (level);

	if (result)
	    goto icmpMaskGetError;

	/* wait for reply */

	tickCount = retransmitSecs * sysClkRateGet ();

	while (tickCount-- > 0)
	    {
	    if (maskReplyReceived)
		{
		*pSubnet = icmpMask;
		muxUnbind (pCookie, MUX_PROTO_SNARF, pBoundRtn);
		return (OK);
		}

	    taskDelay (1);
	    }
	}

    errno = S_icmpLib_TIMEOUT;

    icmpMaskGetError:
        if (pCookie != NULL && pBoundRtn != NULL)
	    muxUnbind (pCookie, MUX_PROTO_SNARF, pBoundRtn);
    return (ERROR);				/* no subnet */
    }

/******************************************************************************
*
* icmpMaskEndInput - END version of input filter for ICMP Mask Reply
*
* This routine filters out the ICMP Address Mask Reply message from
* incoming link frame.  It is bound to MUX by muxBind as a SNARF
* protocol.
*
* RETURNS:
* TRUE indicating the packet was consumed by this routine and no further
* processing needs to be done.
* FALSE indicating the packet was not consumed by this routine and
* further processing needs to be done.
*/

LOCAL BOOL icmpMaskEndInput
    (
    void *              pCookie,        /* device identifier from driver */
    long                type,           /* Protocol type.  */
    M_BLK_ID            pMblk,          /* The whole packet. */
    LL_HDR_INFO *       pLinkHdrInfo,   /* pointer to link level header info */
    void *              pSpare          /* pointer to IP_DRV_CTRL */
    )
    {
    IP_DRV_CTRL *	pDrvCtrl = (IP_DRV_CTRL *) pSpare;
    struct ifnet *      pIf = NULL;
    struct icmp *	pIcmp;
    M_BLK_ID            pMblkOrig;
    M_BLK		tmpM;


    /* already got a reply, or unknown device */

    if (maskReplyReceived || pDrvCtrl == NULL || pMblk == NULL ||
	(pIf = (struct ifnet *)&pDrvCtrl->idr) == NULL)
	return (FALSE);

    if ((pIf->if_flags & IFF_UP) == 0)
        {
        pIf->if_ierrors++;
        return (FALSE);
        }

    /* Make sure the entire Link Hdr is in the first M_BLK */
 
    pMblkOrig = pMblk;
    if (pMblk->mBlkHdr.mLen < pLinkHdrInfo->dataOffset
        && (pMblk = m_pullup (pMblk, pLinkHdrInfo->dataOffset)) == NULL)
        {
        pMblk = pMblkOrig;
        return (FALSE);
	}
 
    /* point to the ip header, and adjust the length */

    bzero ((char *)&tmpM, sizeof (M_BLK));
    bcopy ((char *)pMblk, (char *)&tmpM, sizeof (M_BLK));
    tmpM.mBlkHdr.mData        += pLinkHdrInfo->dataOffset;
    tmpM.mBlkHdr.mLen         -= pLinkHdrInfo->dataOffset;
    tmpM.mBlkPktHdr.len       -= pLinkHdrInfo->dataOffset;
    tmpM.mBlkPktHdr.rcvif     = &pDrvCtrl->idr.ac_if;
 
    /* get and verify icmp */

    pIcmp = (struct icmp *)
	    ipHeaderVerify ((struct ip *) tmpM.mBlkHdr.mData,
			    tmpM.mBlkHdr.mLen, IPPROTO_ICMP);

    if ((pIcmp == NULL) ||
        (checksum ((u_short *) pIcmp, ICMP_MASKLEN) != 0) ||
        (pIcmp->icmp_type != ICMP_MASKREPLY))
        return (FALSE);

    pIf->if_ipackets++;          /* bump statistic */
    pIf->if_lastchange = tickGet();
    pIf->if_ibytes += pMblk->mBlkPktHdr.len;
  
    maskReplyReceived = TRUE;
    icmpMask = ntohl (pIcmp->icmp_mask);
    netMblkClChainFree (pMblk);
    return (TRUE);
    }

/******************************************************************************
*
* icmpMaskNptInput - NPT version of input filter for ICMP Mask Reply
*
* This routine filters out the ICMP Address Mask Reply message from
* incoming link frame.  It is bound to MUX by muxBind as a SNARF
* protocol.
*
* RETURNS:
* TRUE indicating the packet was consumed by this routine and no further
* processing needs to be done.
* FALSE indicating the packet was not consumed by this routine and
* further processing needs to be done.
*/

LOCAL BOOL icmpMaskNptInput
    (
    void *    ipCallbackId,  /* Sent down in muxTkBind call. */
    long      type,          /* Protocol type.  */
    M_BLK_ID  pMblk,         /* The whole packet. */
    void *    pSpareData     /* out of band data */
    )
    {
    IP_DRV_CTRL *	pDrvCtrl = (IP_DRV_CTRL *)ipCallbackId;
    struct ifnet *	pIf = NULL;
    struct icmp *	pIcmp;
    M_BLK_ID            pMblkOrig;
    M_BLK		tmpM;


    /* already got a reply, or unknown device */

    if (maskReplyReceived || pDrvCtrl == NULL || pMblk == NULL ||
	(pIf = (struct ifnet *)&pDrvCtrl->idr) == NULL)
	return (FALSE);

    if ((pIf->if_flags & IFF_UP) == 0)
        {
        pIf->if_ierrors++;
        return (FALSE);
        }


    /* Make sure the entire interface header is in the first M_BLK */
 
    pMblkOrig = pMblk;
    if (pMblk->mBlkHdr.mLen < pIf->if_hdrlen
        && (pMblk = m_pullup (pMblk, pIf->if_hdrlen)) == NULL)
        {
        pMblk = pMblkOrig;
        return (FALSE);
	}
 

    /* point to the network service header, and adjust the length */

    bzero ((char *)&tmpM, sizeof (M_BLK));
    bcopy ((char *)pMblk, (char *)&tmpM, sizeof (M_BLK));
    tmpM.mBlkHdr.mData        += pIf->if_hdrlen;
    tmpM.mBlkHdr.mLen         -= pIf->if_hdrlen;
    tmpM.mBlkPktHdr.len       -= pIf->if_hdrlen;
    tmpM.mBlkPktHdr.rcvif     = &pDrvCtrl->idr.ac_if;


    /* get and verify icmp */

    pIcmp = (struct icmp *)
	    ipHeaderVerify ((struct ip *) tmpM.mBlkHdr.mData,
			    tmpM.mBlkHdr.mLen, IPPROTO_ICMP);

    if (pIcmp == NULL ||
        (checksum ((u_short *) pIcmp, ICMP_MASKLEN) != 0) ||
        (pIcmp->icmp_type != ICMP_MASKREPLY))
        return (FALSE);

    pIf->if_ipackets++;          /* bump statistic */
    pIf->if_lastchange = tickGet();
    pIf->if_ibytes += pMblk->mBlkPktHdr.len;
  
    maskReplyReceived = TRUE; 
    icmpMask = ntohl (pIcmp->icmp_mask);
    netMblkClChainFree (pMblk);
    return (TRUE);
    }

/******************************************************************************
*
* ipHeaderCreate - create a simple IP header
*
* This generates a simple IP header (with no options) and checksums it.
* <proto> specifies the protocol type. <pSrcAddr> and <pDstAddr> define
* the source and destination internet addresses, respectively.  Both should
* be specified in network byte order.  <pih> is a pointer to an internet
* datagram whose length is <length>.
*
* RETURNS: N/A
*
* NOMANUAL
*/

void ipHeaderCreate
    (
    int			proto,		/* protocol number	*/
    struct in_addr *	pSrcAddr,	/* source ip address 	*/
    struct in_addr *	pDstAddr,	/* dest ip address	*/
    struct ip *		pih,		/* internet header 	*/
    int			length		/* datagram size 	*/
    )

    {
    					/* fill in the IP header */
    pih->ip_v = IPVERSION;
    pih->ip_hl = (sizeof (struct ip) >> 2) & 0xf;  
    pih->ip_len	= htons ((u_short) length);
    pih->ip_id	= (u_short) (tickGet () & 0xffff);
    pih->ip_ttl	= MAXTTL;
    pih->ip_p	= (u_char) proto;
    pih->ip_src.s_addr	= pSrcAddr->s_addr;
    pih->ip_dst.s_addr	= pDstAddr->s_addr;

    pih->ip_sum	= 0;	/* zero out the checksum while computing it */
    pih->ip_sum = checksum ((u_short *) pih, (pih->ip_hl << 2));
    }

/*******************************************************************************
*
* ipHeaderVerify - simple IP header verification
*
* ipHeaderVerify performs simple IP header verification.  It does
* sanity checks and verifies the checksum.  <pih> points to an internet
* datagram of length <length>.  <proto> is the expected protocol.
*
* RETURNS: a pointer to the IP data, or NULL if not a valid IP datagram.
*
* NOMANUAL
*/

u_char * ipHeaderVerify
    (
    struct ip *		pih, 		/* internet header	*/
    int			length,		/* length of datagram 	*/
    int			proto  		/* protocol */
    )

    {
    FAST int		options;	/* options offset 	*/

    /* if not minimum size, or right protocol bail */

    if ((length < sizeof (struct ip)) || (pih->ip_p != (u_char) proto))
	return (NULL);
					/* verify checksum */
    if (checksum ((u_short *) pih, (pih->ip_hl << 2)) != 0)
	return (NULL);

    if ((pih->ip_v != IPVERSION) ||
	(ntohs ((u_short) pih->ip_off) & 0x3FFF))
	return (NULL);
					/* ip_hl is in words */
    options = (pih->ip_hl << 2) - sizeof (struct ip);

    return ((u_char *) pih + sizeof (struct ip) + options);
    }