pinglib.c

VXWORKS源代码

/* pingLib.c - Packet InterNet Groper (PING) library */

/* Copyright 1994 - 2002 Wind River Systems, Inc. */
#include "copyright_wrs.h"

/*
modification history
--------------------
01r,22apr02,rae  Note that PING_OPT_DONTROUTE affects pinging localhost
                 (SPR #72917), other minor changes
01q,11mar02,rae  Print stats when task killed (SPR #73570)
01p,08jan02,rae  Don't print error messages when PING_OPT_SILENT (SPR #69537)
01o,15oct01,rae  merge from truestack ver 01q, base 01k (SPRs 67440,
                 30151, 66062, etc.)
01n,30oct00,gnn  Added PING_OPT_NOHOST flag to deal with SPR 22766
01m,08nov99,pul  T2 cumulative patch 2
01l,22sep99,cno  corrected ping error for pingRxPrint() (SPR22571)
01k,14mar99,jdi  doc: removed refs to config.h and/or configAll.h (SPR 25663).
01j,12mar99,p_m  Fixed SPR 8742 by documentating ping() configuration global
                 variables.
01i,05feb99,dgp  document errno values
01h,17mar98,jmb  merge jmb patch of 04apr97 from HPSIM: corrected
                 creation/deletion of task delete hook.
01g,30oct97,cth  changed stack size of tPingTxn from 3000 to 6000 (SPR 8222).
01f,26aug97,spm  removed compiler warnings (SPR #7866)
01e,30sep96,spm  corrected ping error for little-endian machines (SPR #4235)
01d,13mar95,dzb  changed to use free() instead of cfree() (SPR #4113)
01c,24jan95,jdi  doc tweaks
01b,10nov94,rhp  minor edits to man pages
01a,25oct94,dzb  written
*/

/*
DESCRIPTION
This library contains the ping() utility, which tests the reachability
of a remote host.

The routine ping() is typically called from the VxWorks shell to check the
network connection to another VxWorks target or to a UNIX host.  ping()
may also be used programmatically by applications that require such a test.
The remote host must be running TCP/IP networking code that responds to
ICMP echo request packets.  The ping() routine is re-entrant, thus may
be called by many tasks concurrently.

The routine pingLibInit() initializes the ping() utility and allocates
resources used by this library.  It is called automatically when
INCLUDE_PING is defined.
*/

/* includes */

#include "vxWorks.h"
#include "string.h"
#include "stdioLib.h"
#include "wdLib.h"
#include "netLib.h"
#include "sockLib.h"
#include "inetLib.h"
#include "semLib.h"
#include "taskLib.h"
#include "hostLib.h"
#include "ioLib.h"
#include "tickLib.h"
#include "taskHookLib.h"
#include "sysLib.h"
#include "vxLib.h"
#include "netinet/in_systm.h"
#include "netinet/ip.h"
#include "netinet/ip_icmp.h"
#include "netinet/icmp_var.h"
#include "pingLib.h"
#include "errnoLib.h"
#include "kernelLib.h"

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

/* defines */

#define pingError(pPS)	{ pPS->flags |= PING_OPT_SILENT; goto release; }

/* globals */

int	_pingTxLen = 64;			/* size of icmp echo packet */
int	_pingTxInterval = PING_INTERVAL;	/* packet interval in seconds */
int	_pingTxTmo = PING_TMO;			/* packet timeout in seconds */
extern	int errno;

/* locals */

LOCAL PING_STAT	*	pingHead = NULL;	/* ping list head */
LOCAL SEM_ID		pingSem = NULL;		/* mutex for list access */

/* static forward declarations */

LOCAL STATUS pingRxPrint (PING_STAT *pPS, int len, struct sockaddr_in *from,
                          ulong_t now);
LOCAL void pingFinish (WIND_TCB *);

/*******************************************************************************
*
* pingLibInit - initialize the ping() utility
*
* This routine allocates resources used by the ping() utility.
* It is called automatically when INCLUDE_PING is defined.
*
* RETURNS:
* OK
*/

STATUS pingLibInit (void)
    {
    if (pingSem == NULL)			/* already initialized ? */
	{
	if ((pingSem = semMCreate (SEM_Q_PRIORITY | SEM_DELETE_SAFE |
	    SEM_INVERSION_SAFE)) == NULL)
	    return (ERROR);
        }

    return (OK);
    }

/*******************************************************************************
*
* ping - test that a remote host is reachable
*
* This routine tests that a remote host is reachable by sending ICMP
* echo request packets, and waiting for replies.  It may called from
* the VxWorks shell as follows:
* .CS
*    -> ping "remoteSystem", 1, 0
* .CE
* where <remoteSystem> is either a host name that has been previously added
* to the remote host table by a call to hostAdd(), or an Internet address in
* dot notation (for example, "90.0.0.2").
*
* The second parameter, <numPackets>, specifies the number of ICMP packets
* to receive from the remote host.  If <numPackets> is 1, this routine waits
* for a single echo reply packet, and then prints a short message
* indicating whether the remote host is reachable.  For all other values
* of <numPackets>, timing and sequence information is printed as echoed
* packets are received.  If <numPackets> is 0, this routine runs continuously.
* 
* If no replies are received within a 5-second timeout period, the
* routine exits.  An ERROR status is returned if no echo replies
* are received from the remote host.
*
* The following flags may be given through the <options> parameter:
* .iP PING_OPT_SILENT
* Suppress output.  This option is useful for applications that 
* use ping() programmatically to examine the return status.
* .iP PING_OPT_DONTROUTE
* Do not route packets past the local network.  This also prevents pinging
* local addresses (i.e. the IP address of the host itself).  The 127.x.x.x 
* addresses will still work however.
* .iP PING_OPT_NOHOST
* Suppress host lookup.  This is useful when you have the DNS resolver
* but the DNS server is down and not returning host names.
* .iP PING_OPT_DEBUG
* Enables debug output.
* .RS 4 4
* \&NOTE: The following global variables can be set from the target shell
* or Windsh to configure the ping() parameters:
* .iP _pingTxLen 
* Size of the ICMP echo packet (default 64).
* .iP _pingTxInterval
* Packet interval in seconds (default 1 second).
* .iP _pingTxTmo
* Packet timeout in seconds (default 5 seconds).
*
*.RE
* 
* RETURNS:
* OK, or ERROR if the remote host is not reachable.
*
* ERRNO: EINVAL, S_pingLib_NOT_INITIALIZED, S_pingLib_TIMEOUT
*
*/

STATUS ping
    (
    char *		host,		/* host to ping */
    int			numPackets,	/* number of packets to receive */
    ulong_t		options		/* option flags */
    )
    {
    PING_STAT *		pPS;			/* current ping stat struct */
    struct sockaddr_in	to;			/* addr of Tx packet */
    struct sockaddr_in	from;			/* addr of Rx packet */
    int			fromlen = sizeof (from);/* size of Rx addr */
    int			ix = 1;			/* bytes read */
    int			txInterval;		/* packet interval in ticks */
    STATUS		status = ERROR;		/* return status */
    struct fd_set	readFd;
    struct timeval	pingTmo;
    ulong_t		now;
    int			sel;

#ifndef ALT_PING_PAR_SEMANTIC
    if (numPackets < 0)                         /* numPackets positive ? */
        {
        errno = EINVAL;
        return (ERROR);
        }
#else /* alternative parameter semantic for numPackets */
    if (numPackets < -1)		/* numPackets positive or -1 ? */
	{
	errno = EINVAL;
	return (ERROR);
	}
    if (numPackets == 0)
    	numPackets = 3;		/* don't do infinite by default */
    if (numPackets == -1)
    	numPackets = 0;		/* infinite */
#endif /* ALT_PING_PAR_SEMANTIC */

    /* allocate size for ping statistics/info structure */
    if ((pPS = (PING_STAT *) calloc (1, sizeof (PING_STAT))) == NULL)
	return (ERROR);

#ifdef VIRTUAL_STACK
    virtualStackIdCheck();
    pPS->vsid = myStackNum;
#endif /* VIRTUAL_STACK */

    semTake (pingSem, WAIT_FOREVER);		/* get access to list */
    pPS->statNext = pingHead;			/* push session onto list */
    if (pingHead == NULL && !(options & PING_OPT_SILENT))
        if (taskDeleteHookAdd ((FUNCPTR) pingFinish) == ERROR)
	    {
	    free ((char *) pPS);
	    semGive (pingSem);			/* give up access to list */
            if (options & PING_OPT_DEBUG)
            	printf ("ping: unable to add task Delete hook\n");
	    return (ERROR);
	    }
    pingHead = pPS;
    semGive (pingSem);				/* give up access to list */

    pPS->tMin = 999999999;			/* init min rt time */
    pPS->numPacket = numPackets;		/* save num to send */
    pPS->flags = options;			/* save flags field */
    pPS->clkTick = sysClkRateGet ();		/* save sys clk rate */

    txInterval = _pingTxInterval * pPS->clkTick;/* init interval value */

    pingTmo.tv_sec = _pingTxTmo;
    pingTmo.tv_usec = 0;

    pPS->pBufIcmp = (struct icmp *) pPS->bufTx;	/* pointer to icmp header out */
    pPS->pBufTime = (ulong_t *) (pPS->bufTx + 8);/* pointer to time out */

    pPS->idRx = taskIdSelf ();			/* get own task Id  */

    /* initialize the socket address struct */

    to.sin_family = AF_INET;
    if ((to.sin_addr.s_addr = inet_addr (host)) == (u_long) ERROR)
	{
	if ((to.sin_addr.s_addr = hostGetByName (host)) == (u_long) ERROR)
	    {
            if (!(options & PING_OPT_SILENT))
	        printf ("ping: unknown host %s\n", host);

	    pingError (pPS);
	    }

	inet_ntoa_b (to.sin_addr, pPS->toInetName);
        }
    
    strcpy (pPS->toHostName, host);		   /* save host name */
    _pingTxLen = max (_pingTxLen, PING_MINPACKET); /* sanity check global */
    _pingTxLen = min (_pingTxLen, PING_MAXPACKET); /* sanity check global */
    pPS->dataLen = _pingTxLen - 8;		   /* compute size of data */

    /* open raw socket for ICMP communication */

    if ((pPS->pingFd = socket (AF_INET, SOCK_RAW, ICMP_PROTO)) < 0)
	pingError (pPS);

    if (options & PING_OPT_DONTROUTE)		/* disallow packet routing ? */
        if (setsockopt (pPS->pingFd, SOL_SOCKET, SO_DONTROUTE, (char *) &ix,
	    sizeof (ix)) == ERROR)