icmplib.c

VXWORKS源代码

/* icmpLib.c - VxWorks library for ICMP routines */

/* Copyright 1984 - 2002 Wind River Systems, Inc. */
#include "copyright_wrs.h"

/*
modification history
--------------------
01q,29jan02,vvv  fixed icmpMaskGet to use unfreed mblk when retransmitting
		 (SPR #72867)
01p,15oct01,rae  merge from truestack ver 01t, base 01o (no ether hooks)
01o,17mar99,spm  added support for identical unit numbers (SPR #20913)
01n,17nov98,n_s  fixed icmpMaskGet for non-END devices. spr 23005.
01m,08dec97,gnn  END code review fixes.
01l,05oct97,vin  added header file ip_var.h
01k,03oct97,gnn  removed necessity for endDriver global
01j,25sep97,gnn  SENS beta feedback fixes
01i,12aug97,gnn  changes necessitated by MUX/END update.
01h,20jan97,vin  added icmpLibInit for scaling.
01g,17dec96,gnn  added code to handle the new etherHooks and END stuff.
01f,05aug94,dzb  set IP address of interface in arpcom struct (SPR #2706).
01e,30jun92,jmm  moved checksum() to vxLib
01d,11jun92,elh	 changed parameters to ipHeaderCreate.
01c,26may92,rrr  the tree shuffle
		  -changed includes to have absolute path from h/
01b,16apr92,elh	 moved routines shared by bootpLib here.
01a,11mar91,elh	 written.
*/

/*
DESCRIPTION
icmpLib contains routines that use ICMP.  icmpMaskGet is currently the only 
routine in this library.  icmpMaskGet generates and sends an ICMP address
mask request to obtain the subnet mask of the network.

The routine icmpLibInit() is responsible for configuring the ICMP protocol
with various parameters.

To use this feature, include the following component:
INCLUDE_ICMP
*/

/* includes */

#include "vxWorks.h"
#include "net/protosw.h"
#include "net/domain.h"
#include "netinet/in.h"
#include "netinet/in_systm.h"
#include "netinet/in_pcb.h"
#include "netinet/ip_var.h"
#include "netinet/ip.h"
#include "netinet/ip_icmp.h"
#include "netLib.h"
#include "errno.h"
#include "icmpLib.h"
#include "sysLib.h"
#include "string.h"
#include "taskLib.h"
#include "stdio.h"
#include "tickLib.h"
#include "inetLib.h"
#include "vxLib.h"
#include "end.h"
#include "ipProto.h"
#include "muxLib.h"
#include "muxTkLib.h"
#include "private/muxLibP.h"

#ifdef VIRTUAL_STACK
#include "netinet/vsLib.h"
#endif

/* externs */

#ifndef VIRTUAL_STACK
IMPORT int		_protoSwIndex;
IMPORT struct protosw 	inetsw [IP_PROTO_NUM_MAX]; 
IMPORT int		icmpmaskrepl;
#endif

/* defines */

#define ICMP_REXMT_DELAY	1	/* retransmit delay (secs) */
#define ICMP_MAX_SEND		2	/* maximum requests */

/* locals */

#ifndef VIRTUAL_STACK
LOCAL	BOOL	      maskReplyReceived = FALSE; /* recv mask reply 	*/
LOCAL	int	      icmpMask = 0;		/* replied icmp mask    */

LOCAL struct
    {
    struct ip	ih;				/* IP header		*/
    struct icmp	icmph;				/* ICMP header		*/
    } icmpMsg;
#endif

LOCAL BOOL icmpMaskEndInput (void * pCookie, long type, M_BLK_ID pBuff,
			     LL_HDR_INFO * pLinkHdrInfo, void * pSpare);

LOCAL BOOL icmpMaskNptInput (void * callbackId ,long type, M_BLK_ID pBuff,
			     void * pSpareData);

/* forward declarations */

IMPORT int in_broadcast ();

/******************************************************************************
 *
 * icmpLibInit - initialize icmpLib 
 *
 * This routine initializes icmpLib.
 *
 * RETURNS: OK if successful, otherwise ERROR.
 *
 * NOMANUAL
 */

STATUS icmpLibInit 
    (
    ICMP_CFG_PARAMS * 	icmpCfg		/* icmp configuration parameters */
    )
    {
    FAST struct protosw	* pProtoSwitch; 

    if (_protoSwIndex >= sizeof(inetsw)/sizeof(inetsw[0]))
	return (ERROR) ;

    pProtoSwitch = &inetsw [_protoSwIndex]; 

    if (pProtoSwitch->pr_domain != NULL)
	return (OK); 				/* already initialized */

    pProtoSwitch->pr_type   	=  SOCK_RAW;
    pProtoSwitch->pr_domain   	=  &inetdomain;
    pProtoSwitch->pr_protocol   =  IPPROTO_ICMP;
    pProtoSwitch->pr_flags	=  PR_ATOMIC | PR_ADDR;
    pProtoSwitch->pr_input	=  icmp_input;
    pProtoSwitch->pr_output	=  rip_output;
    pProtoSwitch->pr_ctlinput	=  0;
    pProtoSwitch->pr_ctloutput	=  rip_ctloutput;
    pProtoSwitch->pr_usrreq	=  rip_usrreq;
    pProtoSwitch->pr_init	=  icmp_init;
    pProtoSwitch->pr_fasttimo	=  0;
    pProtoSwitch->pr_slowtimo	=  0;
    pProtoSwitch->pr_drain	=  0;
    pProtoSwitch->pr_sysctl	=  0;

    _protoSwIndex++; 

    /* initialize icmp configuration parameters */

    icmpmaskrepl = (icmpCfg->icmpCfgFlags & ICMP_DO_MASK_REPLY) ? TRUE : FALSE;

    return (OK); 
    }

/******************************************************************************
*
* icmpMaskGet - obtain the subnet mask 
*
* icmpMask broadcasts an ICMP Address Mask Request over the network
* interface specified by <ifName> to obtain the subnet mask of that
* network.
* This interface must have been previously attached and initialized.
*
* <src> specifies the source IP address, which must be set.
*
* <dst> specifies destination of ICMP request.  A NULL value for
* <dst> results in the request being broadcasted.  However, because
* ICMP mask request/reply behaves differently on each ICMP
* implementation, thus the ICMP mask reply by broadcasting ICMP mask
* request is not guranteed.
*
* The subnet mask gets returned in <pSubnet> in host byte order.
*
* NOTE: This routine can be used for END or NPT driver only.
*
* RETURNS: OK if successful, otherwise ERROR.
*
* ERRNO
*   S_icmpLib_NO_BROADCAST
*   S_icmpLib_INVALID_INTERFACE
*   S_icmpLib_TIMEOUT
*
*/

STATUS icmpMaskGet
    (
    char *		ifName,		/* network interface name */
    char * 		src,		/* optional src address */
    char *		dst,		/* optional dst address */
    int	 *		pSubnet		/* return subnet mask 	*/
    )
    {
    FAST int 		retransmitSecs;	/* retransmit time 	*/
    FAST int		tickCount;
    int			ix;		/* index 		*/
    struct in_addr	srcAddr;	/* source address 	*/
    struct sockaddr_in	dstAddr;	/* destination address	*/
    struct ifnet *	pIf;		/* pointer to interface */
    IP_DRV_CTRL *	pDrvCtrl;
    struct mbuf *	pMbuf;
    void *		pCookie = NULL;
    FUNCPTR		pBoundRtn = NULL;
    int 		level;
    int 		result;

    /* reset flags */

    maskReplyReceived = FALSE;
    icmpMask = 0;

    /* verify arguments and the I/F if attached END/NPT */

    if (pSubnet == NULL                                      ||
        (pIf = ifunit (ifName)) == NULL                      ||
	pIf->if_output == NULL                               ||
	(endFindByName (pIf->if_name, pIf->if_unit)) == NULL ||
	(pDrvCtrl = (IP_DRV_CTRL *)pIf->pCookie) == NULL)
	{
	errno = S_icmpLib_INVALID_INTERFACE;
	goto icmpMaskGetError;
	}


    /* build IP address */

    if (src == NULL)
        {
        errno = S_icmpLib_INVALID_ARGUMENT;
	goto icmpMaskGetError;
        }

    /* bind IP address to ac */

    srcAddr.s_addr = inet_addr (src);
    ((struct arpcom *) pIf)->ac_ipaddr.s_addr = srcAddr.s_addr;

    bzero ((char *)&dstAddr, sizeof (struct sockaddr_in));

    if (dst == NULL)
	{
        if ((pIf->if_flags & IFF_BROADCAST) == 0)
	    {
	    errno = S_icmpLib_NO_BROADCAST;	/* no broadcasts */
	    goto icmpMaskGetError;
	    }
	dstAddr.sin_addr.s_addr = htonl (INADDR_BROADCAST);
	}
    else
	dstAddr.sin_addr.s_addr = inet_addr (dst);

    dstAddr.sin_len = sizeof (struct sockaddr_in);
    dstAddr.sin_family = AF_INET;

    pIf->if_flags |= (IFF_UP | IFF_RUNNING);

    retransmitSecs	= ICMP_REXMT_DELAY; 	/* set delay value */
    maskReplyReceived	= FALSE;


    /* fill in ICMP message and put it in an mbuf */

    bzero ((char *) &icmpMsg, sizeof (icmpMsg));
    icmpMsg.icmph.icmp_type  = ICMP_MASKREQ;
    icmpMsg.icmph.icmp_code  = 0;
    icmpMsg.icmph.icmp_cksum = 0;
    icmpMsg.icmph.icmp_cksum = checksum ((u_short *) &icmpMsg.icmph, 
					 ICMP_MASKLEN);

    ipHeaderCreate (IPPROTO_ICMP, &srcAddr, &dstAddr.sin_addr,
		    &icmpMsg.ih, sizeof (struct ip) + ICMP_MASKLEN);


    /* bind icmpMaskHook as SNARF */

    if (muxTkDrvCheck (pIf->if_name))
	{
	pCookie = muxTkBind (pIf->if_name, pIf->if_unit,
			     (FUNCPTR)icmpMaskNptInput, NULL, NULL, NULL,
			     MUX_PROTO_SNARF, "ICMP HOOK NPT",
			     pDrvCtrl, NULL, NULL);
	pBoundRtn = (FUNCPTR) icmpMaskNptInput;
	}
    else
	{
	pCookie = muxBind (pIf->if_name, pIf->if_unit,
			   (FUNCPTR)icmpMaskEndInput, NULL, NULL, NULL,
			   MUX_PROTO_SNARF, "ICMP HOOK END",
			   pDrvCtrl);
	pBoundRtn = (FUNCPTR) icmpMaskEndInput;
	}