ip_icmp.c

VXWORKS源代码

/* ip_icmp.c - internet ICMP routines */

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

/*
 * Copyright (c) 1982, 1986, 1988, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)ip_icmp.c	8.2 (Berkeley) 1/4/94
 */

/*
modification history
--------------------
03h,18apr02,vvv  removed incorrect icmpmaskrepl initialization from icmp_init
		 (SPR #74338)
03g,18dec01,vvv  reflect messages with correct source address (SPR #71684)
03f,12oct01,rae  merge from truestack ver 03j, base 03e (SPRs 69344, 69683 etc)
03e,16mar99,spm  recovered orphaned code from tor2_0_x branch (SPR #25770)
03d,09feb99,ham  fixed SPR#24975.
03c,31jan97,vin  changed declaration according to prototype decl in protosw.h
03b,07jan96,vin  added icmp_init(..) for scalability, moved iptime to 
		 ip_input.c
03a,31oct96,vin  changed m_gethdr(..) to mHdrClGet(..).
02u,24aug96,vin  integrated with BSD44 and 02t of ip_icmp.c.
*/

/*
 * ICMP routines: error generation, receive packet processing, and
 * routines to turnaround packets back to the originator, and
 * host table maintenance routines.
 */

#include "vxWorks.h"
#include "net/mbuf.h"
#include "net/protosw.h"
#include "sys/socket.h"
#include "sys/ioctl.h"
#include "net/systm.h"
#include "net/route.h"
#include "net/if.h"
#include "net/if_types.h"

#include "netinet/in.h"
#include "netinet/in_systm.h"
#include "netinet/in_var.h"
#include "netinet/ip.h"
#include "netinet/ip_var.h"
#include "netinet/ip_icmp.h"
#include "netinet/icmp_var.h"

#ifdef WV_INSTRUMENTATION
#ifdef INCLUDE_WVNET
#include "wvNetLib.h"
#endif
#endif

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

/* defines */

#ifndef VIRTUAL_STACK
#define MAXTABLESIZE 64		/*
                                 * smallest cluster limits setsockopt() 
                                 * routine to 64 2-byte integers
                                 */
#endif /* VIRTUAL_STACK */

#define PATHMTU_MIN  68 	/* Lowest allowable path MTU estimate */

/* externs */

extern void pfctlinput ();

#ifndef VIRTUAL_STACK
extern	struct protosw inetsw[];
extern VOIDFUNCPTR	_icmpErrorHook; 
#endif /* VIRTUAL_STACK */

/* globals */

#ifndef VIRTUAL_STACK
struct icmpstat icmpstat;
struct sockaddr_in icmpmask = { 8, 0 };

int	icmpmaskrepl = 0;
#ifdef ICMPPRINTFS
int	icmpprintfs = 0;
#endif
#endif /* VIRTUAL_STACK */

/* locals */

#ifndef VIRTUAL_STACK
static struct sockaddr_in icmpsrc = { sizeof (struct sockaddr_in), AF_INET };
static struct sockaddr_in icmpdst = { sizeof (struct sockaddr_in), AF_INET };
static struct sockaddr_in icmpgw = { sizeof (struct sockaddr_in), AF_INET };

LOCAL u_short mtuTable [MAXTABLESIZE] = {68, 296, 508, 1006, 1492, 2002,
                                         4352, 8166, 17914, 32000, 65535};
LOCAL int mtuTableSize = 11;
#endif /* VIRTUAL_STACK */

/* forward declarations */
static void	icmp_error (struct mbuf *, int, int, n_long, struct ifnet *);
static void	icmp_reflect (struct mbuf *);
static void	icmp_send (struct mbuf *, struct mbuf *);
LOCAL void ip_next_mtu (struct sockaddr *, int);

#ifdef WV_INSTRUMENTATION
#ifdef INCLUDE_WVNET
    /* Set common fields of event identifiers for this module. */

LOCAL UCHAR wvNetModuleId = WV_NET_IPICMP_MODULE;   /* Value for ip_icmp.c */
LOCAL UCHAR wvNetLocalFilter = WV_NET_NONE;     /* Available event filter */

LOCAL ULONG wvNetEventId;       /* Event identifier: see wvNetLib.h */
#endif    /* INCLUDE_WVNET */
#endif

void
icmp_init()
{
	if (_icmpErrorHook == NULL)	/* initialize the hook if not null */
	    _icmpErrorHook = icmp_error; 

#ifdef ICMPPRINTFS
        icmpprintfs = 0;
#endif

        icmpsrc.sin_len = sizeof(struct sockaddr_in);
        icmpsrc.sin_family = AF_INET;
        icmpdst.sin_len = sizeof(struct sockaddr_in);
        icmpdst.sin_family = AF_INET;
        icmpgw.sin_len = sizeof(struct sockaddr_in);
        icmpgw.sin_family = AF_INET;

        mtuTable[0] = 68;
        mtuTable[1] = 296;
        mtuTable[2] = 508;
        mtuTable[3] = 1006;
        mtuTable[4] = 1492;
        mtuTable[5] = 2002;
        mtuTable[6] = 4352;
        mtuTable[7] = 8166;
        mtuTable[8] = 17914;
        mtuTable[9] = 32000;
        mtuTable[10] = 65535;
        mtuTableSize = 11;
}

/*
 * ICMP routines: error generation, receive packet processing, and
 * routines to turnaround packets back to the originator, and
 * host table maintenance routines.
 */

/*
 * Generate an error packet of type error
 * in response to bad packet ip.
 */
static void
icmp_error(n, type, code, dest, destifp)
	struct mbuf *n;
	int type, code;
	n_long dest;
	struct ifnet *destifp;
{
	register struct ip *oip = mtod(n, struct ip *), *nip;
	register unsigned oiplen = oip->ip_hl << 2;
	register struct icmp *icp;
	register struct mbuf *m;
        MTU_QUERY mtuQuery;
	unsigned icmplen;
	short    offset;

#ifdef WV_INSTRUMENTATION
#ifdef INCLUDE_WVNET    /* WV_NET_EMERGENCY or WV_NET_ALERT event */
        if (type == ICMP_SOURCEQUENCH) 	/* ENOBUFS error: out of memory. */
            {
            WV_NET_MARKER_2 (NET_CORE_EVENT, WV_NET_EMERGENCY, 9, 2, 
                             WV_NETEVENT_ICMPERR_START, type, code)
            }
        else
            {
            WV_NET_MARKER_2 (NET_CORE_EVENT, WV_NET_CRITICAL, 8, 2, 
                             WV_NETEVENT_ICMPERR_START, type, code)
            }
#endif  /* INCLUDE_WVNET */
#endif

#ifdef ICMPPRINTFS
	if (icmpprintfs)
		printf("icmp_error(%x, %d, %d)\n", oip, type, code);
#endif
	if (type != ICMP_REDIRECT)
	    {
#ifdef VIRTUAL_STACK
	    _icmpstat.icps_error++;
#else
	    icmpstat.icps_error++;
#endif /* VIRTUAL_STACK */
            offset = oip->ip_off;
	    }
        else
	    {
            /* 
	     * If ICMP_REDIRECT, offset field is in network host order
	     * (changed when ip_output forwarded this packet). We need it 
	     * to be in host order for the processing.
	     */

	    offset = ntohs (oip->ip_off);
	    }

	/*
	 * Don't send error if not the first fragment of message.
	 * Don't error if the old packet protocol was ICMP
	 * error message, only known informational types.
	 */
	if (offset &~ (IP_MF|IP_DF))
		goto freeit;
	if (oip->ip_p == IPPROTO_ICMP && type != ICMP_REDIRECT &&
	  n->m_len >= oiplen + ICMP_MINLEN &&
	  !ICMP_INFOTYPE(((struct icmp *)((caddr_t)oip + oiplen))->icmp_type)) {
#ifdef VIRTUAL_STACK
		_icmpstat.icps_oldicmp++;
#else
		icmpstat.icps_oldicmp++;
#endif /* VIRTUAL_STACK */
		goto freeit;
	}
	/* Don't send error in response to a multicast or broadcast packet */
	if (n->m_flags & (M_BCAST|M_MCAST))
		goto freeit;
	/*
	 * First, formulate icmp message
	 */
	if ((m = mHdrClGet(M_DONTWAIT, MT_HEADER, CL_SIZE_128, TRUE)) == NULL)
		goto freeit;
	icmplen = oiplen + min(8, oip->ip_len);
	m->m_len = icmplen + ICMP_MINLEN;
	MH_ALIGN(m, m->m_len);
	icp = mtod(m, struct icmp *);
	if ((u_int)type > ICMP_MAXTYPE)
            {
#ifdef WV_INSTRUMENTATION
#ifdef INCLUDE_WVNET    /* WV_NET_EMERGENCY event */
            WV_NET_MARKER_1 (NET_CORE_EVENT, WV_NET_EMERGENCY, 14, 1, 
                             WV_NETEVENT_ICMPERR_PANIC, type)
#endif  /* INCLUDE_WVNET */
#endif

            panic("icmp_error");
            }
#ifdef VIRTUAL_STACK
	_icmpstat.icps_outhist[type]++;
#else
	icmpstat.icps_outhist[type]++;
#endif /* VIRTUAL_STACK */
	icp->icmp_type = type;
	if (type == ICMP_REDIRECT)
		icp->icmp_gwaddr.s_addr = dest;
	else {
		icp->icmp_void = 0;
		/* 
		 * The following assignments assume an overlay with the
		 * zeroed icmp_void field.
		 */
		if (type == ICMP_PARAMPROB) {
			icp->icmp_pptr = code;
			code = 0;
		} else if (type == ICMP_UNREACH &&
			code == ICMP_UNREACH_NEEDFRAG && destifp) {

                        /*
                         * Point-to-multipoint devices allow a separate MTU
                         * for each destination address. Get that value or
                         * leave the next MTU unspecified if not available.
                         */

                        if (destifp->if_type == IFT_PMP)
                            {
                            mtuQuery.family = AF_INET;
                            mtuQuery.dstIpAddr = dest;
                            if (destifp->if_ioctl (destifp, SIOCGMTU,
                                                   (caddr_t) &mtuQuery) == 0)
                                {
                                icp->icmp_nextmtu = htons (mtuQuery.mtu);
                                }
                            }
                        else
                            {
                            icp->icmp_nextmtu = htons(destifp->if_mtu);
                            }
		}
	}

	icp->icmp_code = code;
	bcopy((caddr_t)oip, (caddr_t)&icp->icmp_ip, icmplen);
	nip = &icp->icmp_ip;

	if (type != ICMP_REDIRECT)
	    {
	    /*
	     * If ICMP_REDIRECT, these changes have already been made in 
	     * ip_output when the packet was forwarded.
	     */

	    nip->ip_len = htons((u_short)(nip->ip_len + oiplen));
	    HTONS (nip->ip_id);
	    HTONS (nip->ip_off);
	    }

	/*
	 * Now, copy old ip header (without options)
	 * in front of icmp message.
	 */
	if (m->m_data - sizeof(struct ip) < m->m_extBuf)
		panic("icmp len");
	m->m_data -= sizeof(struct ip);
	m->m_len += sizeof(struct ip);
	m->m_pkthdr.len = m->m_len;
	m->m_pkthdr.rcvif = n->m_pkthdr.rcvif;
	nip = mtod(m, struct ip *);
	bcopy((caddr_t)oip, (caddr_t)nip, sizeof(struct ip));
	nip->ip_len = m->m_len;
	nip->ip_hl = sizeof(struct ip) >> 2;
	nip->ip_p = IPPROTO_ICMP;
	nip->ip_tos = 0;
	icmp_reflect(m);

freeit:
	m_freem(n);
}

/*
 * Process a received ICMP message.
 */
void