if_subr.c

vxworks下的实现网络TCPIP协议的原代码

/* if_subr.c - common routines for network interface drivers */

/* Copyright 1990-1996 Wind River Systems, Inc. */
#include "copyright_wrs.h"

/*
 * Copyright (c) 1982, 1989, 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.
 *
 *	@(#)if_ethersubr.c	8.1 (Berkeley) 6/10/93
 */

/*
modification history
--------------------
01h,21aug98,n_s  updated if_omcast in ether_output () if_noproto in 
                 do_protocol_with_type (). spr21074
01f,19sep97,vin  modified build_cluster to incorporate cluster blks,
		 removed pointers to refcounts.
01g,11aug97,vin  changed mBlkGet to use _pNetDpool.
01e,10jul97,vin  removed unsupported revarpinput() code.
01f,05jun97,vin  corrected processing for promiscuous interfaces in
		 ether_input.
01e,02jun97,spm  updated man page for bcopy_to_mbufs()
01d,15may97,vin  reworked ether_input, cleanup, added copyFromMbufs().
		 removed support for check_trailer().
01c,16dec96,vin  removed unnecessary ntohs(). 
01b,13nov96,vin  replaced m_gethdr with mBlkGet() in buildCluster.
01a,03mar96,vin  created from BSD4.4 stuff,integrated with 02p of if_subr.c
*/

#include "vxWorks.h"
#include "stdlib.h"
#include "stdio.h"
#include "tickLib.h"
#include "logLib.h"
#include "errno.h"
#include "netinet/in.h"
#include "netinet/in_systm.h"
#include "netinet/in_var.h"
#include "netinet/ip.h"
#include "net/if.h"
#include "net/if_arp.h"
#include "netinet/if_ether.h"
#include "net/if_subr.h"
#include "netinet/in_var.h"
#include "net/mbuf.h"
#include "net/route.h"
#include "net/if_llc.h"
#include "net/if_dl.h"
#include "net/if_types.h"
#include "lstLib.h"
#include "netLib.h"

typedef struct net_type
    {
    NODE     	node;
    FUNCPTR     inputRtn;
    int     	etherType;
    } NET_TYPE;

/* externs */

extern	struct ifnet loif;
extern  looutput();

u_char	etherbroadcastaddr[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
u_char	ether_ipmulticast_min[6] = { 0x01, 0x00, 0x5e, 0x00, 0x00, 0x00 };
u_char	ether_ipmulticast_max[6] = { 0x01, 0x00, 0x5e, 0x7f, 0xff, 0xff };

#define senderr(e) { error = (e); goto bad;}

LOCAL LIST netTypeList;

/*
 * Ethernet output routine.
 * Encapsulate a packet of type family for the local net.
 * Use trailer local net encapsulation if enough data in first
 * packet leaves a multiple of 512 bytes of data in remainder.
 * Assumes that ifp is actually pointer to arpcom structure.
 */
int
ether_output(ifp, m0, dst, rt0)
	register struct ifnet *ifp;
	struct mbuf *m0;
	struct sockaddr *dst;
	struct rtentry *rt0;
{
	u_short etype;
	int s, error = 0;
 	u_char edst[6];
	register struct mbuf *m = m0;
	register struct rtentry *rt;
	struct mbuf *mcopy = (struct mbuf *)0;
	register struct ether_header *eh;
	int off, len = m->m_pkthdr.len;
	struct arpcom *ac = (struct arpcom *)ifp;

	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING))
		senderr(ENETDOWN);
	ifp->if_lastchange = tickGet();
	if ((rt = rt0)) {
		if ((rt->rt_flags & RTF_UP) == 0) {
			if ((rt0 = rt = rtalloc1(dst, 1)))
				rt->rt_refcnt--;
			else 
				senderr(EHOSTUNREACH);
		}
		if (rt->rt_flags & RTF_GATEWAY) {
			if (rt->rt_gwroute == 0)
				goto lookup;
			if (((rt = rt->rt_gwroute)->rt_flags & RTF_UP) == 0) {
				rtfree(rt); rt = rt0;
			lookup: rt->rt_gwroute = rtalloc1(rt->rt_gateway, 1);
				if ((rt = rt->rt_gwroute) == 0)
					senderr(EHOSTUNREACH);
			}
		}
		if (rt->rt_flags & RTF_REJECT)
			if (rt->rt_rmx.rmx_expire == 0 ||
			    tickGet() < rt->rt_rmx.rmx_expire)
				senderr(rt == rt0 ? EHOSTDOWN : EHOSTUNREACH);
	}
	switch (dst->sa_family) {

#ifdef INET
	case AF_INET:
		if (!arpresolve(ac, rt, m, dst, edst))
			return (0);	/* if not yet resolved */
		/* If broadcasting on a simplex interface, loopback a copy */
		if ((m->m_flags & M_BCAST) && (ifp->if_flags & IFF_SIMPLEX))
			mcopy = m_copy(m, 0, (int)M_COPYALL);
		off = m->m_pkthdr.len - m->m_len;
		etype = ETHERTYPE_IP;
		break;
#endif
	case AF_UNSPEC:
		eh = (struct ether_header *)dst->sa_data;
 		bcopy((caddr_t)eh->ether_dhost, (caddr_t)edst, sizeof (edst));
		etype = eh->ether_type;
		break;

	default:
		printf("%s%d: can't handle af%d\n", ifp->if_name, ifp->if_unit,
			dst->sa_family);
		senderr(EAFNOSUPPORT);
	}

	if (mcopy)
		(void) looutput(ifp, mcopy, dst, rt);
	/*
	 * Add local net header.  If no space in first mbuf,
	 * allocate another.
	 */
	M_PREPEND(m, sizeof (struct ether_header), M_DONTWAIT);

	if (m == 0)
		senderr(ENOBUFS);
	eh = mtod(m, struct ether_header *);
	etype = htons(etype);
	bcopy((caddr_t)&etype,(caddr_t)&eh->ether_type,
		sizeof(eh->ether_type));
 	bcopy((caddr_t)edst, (caddr_t)eh->ether_dhost, sizeof (edst));
 	bcopy((caddr_t)ac->ac_enaddr, (caddr_t)eh->ether_shost,
	    sizeof(eh->ether_shost));
	s = splimp();
	/*
	 * Queue message on interface, and start output if interface
	 * not yet active.
	 */
	if (IF_QFULL(&ifp->if_snd)) {
		IF_DROP(&ifp->if_snd);
		splx(s);
		senderr(ENOBUFS);
	}
	IF_ENQUEUE(&ifp->if_snd, m);

	if ((ifp->if_flags & IFF_OACTIVE) == 0)
		(*ifp->if_start)(ifp);
	splx(s);
	ifp->if_obytes += len + sizeof (struct ether_header);
	if (m->m_flags & M_MCAST || m->m_flags & M_BCAST)
		ifp->if_omcasts++;
	return (error);

bad:
	if (m)
		m_freem(m);
	return (error);
}

/*******************************************************************************
*
* do_protocol - check the link-level type field and process IP and ARP data
*
* This routine must not be called at interrupt level.
* Process a received Ethernet packet;
* the packet is in the mbuf chain m without
* the ether header, which is provided separately.
*
* NOMANUAL
*/

void
ether_input(ifp, eh, m)
	struct ifnet *ifp;
	register struct ether_header *eh;
	struct mbuf *m;
{
	u_short 		etype;
	struct arpcom *		ac = (struct arpcom *)ifp;

	if ((ifp->if_flags & IFF_UP) == 0) {
		m_freem(m);
		return;
	}
	ifp->if_lastchange = tickGet();
	ifp->if_ibytes += m->m_pkthdr.len + sizeof (*eh);
	if (eh->ether_dhost[0] & 1) {
		if (bcmp((caddr_t)etherbroadcastaddr, (caddr_t)eh->ether_dhost,
		    sizeof(etherbroadcastaddr)) == 0)
			m->m_flags |= M_BCAST;
		else
			m->m_flags |= M_MCAST;
		ifp->if_imcasts++;
	}

        if (ifp->if_flags & IFF_PROMISC)
            {
            /*
             * do not hand over the non multicast packets to the ip stack
             * if they are not destined to us, orelse it confuses the
             * ip forwarding logic and keeps sending unnecessary redirects.
             * If packets destined for other hosts have to be snooped they
             * have to done through driver level hooks.
             */
            
            if (!(m->m_flags & (M_BCAST | M_MCAST)))
                {
                if (bcmp ((caddr_t)ac->ac_enaddr, (caddr_t)eh->ether_dhost,
                          sizeof(eh->ether_dhost)) != 0)
                    {
                    m_freem (m); 	/* free the packet chain */
                    return; 
                    }
                }
            }
        
	etype = ntohs(eh->ether_type);

        /* add code here to process IEEE802.3 LLC format, Hook!! */

        /* demux the packet and hand off the ip layer */
        do_protocol_with_type (etype, m , ac, m->m_pkthdr.len); 
}

/*
 * Perform common duties while attaching to interface list
 */
void
ether_ifattach(ifp)
	register struct ifnet *ifp;
{
	register struct ifaddr *ifa;
	register struct sockaddr_dl *sdl;

	ifp->if_type = IFT_ETHER;
	ifp->if_addrlen = 6;
	ifp->if_hdrlen = 14;
	ifp->if_mtu = ETHERMTU;
	for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next)
		if ((sdl = (struct sockaddr_dl *)ifa->ifa_addr) &&
		    sdl->sdl_family == AF_LINK) {
			sdl->sdl_type = IFT_ETHER;
			sdl->sdl_alen = ifp->if_addrlen;
			bcopy((caddr_t)((struct arpcom *)ifp)->ac_enaddr,
			      LLADDR(sdl), ifp->if_addrlen);
			break;
		}
}

/*
 * Add an Ethernet multicast address or range of addresses to the list for a
 * given interface.
 */
int
ether_addmulti(ifr, ac)
	struct ifreq *ifr;
	register struct arpcom *ac;
{
	register struct ether_multi *enm;
	struct sockaddr_in *sin;
	u_char addrlo[6];
	u_char addrhi[6];
	int s = splimp();

	switch (ifr->ifr_addr.sa_family) {

	case AF_UNSPEC:
		bcopy((char *)ifr->ifr_addr.sa_data, (char *)addrlo, 6);
		bcopy((char *) addrlo, (char *)addrhi, 6);
		break;

#ifdef INET
	case AF_INET:
		sin = (struct sockaddr_in *)&(ifr->ifr_addr);
		if (sin->sin_addr.s_addr == INADDR_ANY) {
			/*
			 * An IP address of INADDR_ANY means listen to all
			 * of the Ethernet multicast addresses used for IP.
			 * (This is for the sake of IP multicast routers.)
			 */
			bcopy((char *)ether_ipmulticast_min, (char *)addrlo, 6);
			bcopy((char *)ether_ipmulticast_max, (char *)addrhi, 6);
		}
		else {
			ETHER_MAP_IP_MULTICAST(&sin->sin_addr, addrlo);
			bcopy((char *)addrlo, (char *)addrhi, 6);
		}
		break;
#endif

	default:
		splx(s);
		return (EAFNOSUPPORT);
	}

	/*
	 * Verify that we have valid Ethernet multicast addresses.
	 */
	if ((addrlo[0] & 0x01) != 1 || (addrhi[0] & 0x01) != 1) {
		splx(s);
		return (EINVAL);
	}
	/*
	 * See if the address range is already in the list.
	 */
	ETHER_LOOKUP_MULTI(addrlo, addrhi, ac, enm);
	if (enm != NULL) {
		/*
		 * Found it; just increment the reference count.
		 */
		++enm->enm_refcount;
		splx(s);
		return (0);
	}
	/*
	 * New address or range; malloc a new multicast record
	 * and link it into the interface's multicast list.
	 */
        MALLOC (enm, struct ether_multi *, sizeof(*enm), MT_IFMADDR, 
		M_DONTWAIT);
	if (enm == NULL) {
		splx(s);
		return (ENOBUFS);
	}
	bcopy((char *)addrlo, (char *)enm->enm_addrlo, 6);
	bcopy((char *)addrhi, (char *)enm->enm_addrhi, 6);
	enm->enm_ac = ac;
	enm->enm_refcount = 1;
	enm->enm_next = ac->ac_multiaddrs;
	ac->ac_multiaddrs = enm;
	ac->ac_multicnt++;
	splx(s);
	/*
	 * Return ENETRESET to inform the driver that the list has changed
	 * and its reception filter should be adjusted accordingly.
	 */
	return (ENETRESET);
}

/*
 * Delete a multicast address record.
 */
int
ether_delmulti(ifr, ac)
	struct ifreq *ifr;
	register struct arpcom *ac;
{
	register struct ether_multi *enm;
	register struct ether_multi **p;
	struct sockaddr_in *sin;
	u_char addrlo[6];
	u_char addrhi[6];
	int s = splimp();

	switch (ifr->ifr_addr.sa_family) {

	case AF_UNSPEC:
		bcopy((char *)ifr->ifr_addr.sa_data, (char *)addrlo, 6);
		bcopy((char *)addrlo, (char *)addrhi, 6);
		break;

#ifdef INET
	case AF_INET:
		sin = (struct sockaddr_in *)&(ifr->ifr_addr);
		if (sin->sin_addr.s_addr == INADDR_ANY) {
			/*
			 * An IP address of INADDR_ANY means stop listening
			 * to the range of Ethernet multicast addresses used
			 * for IP.
			 */
			bcopy((char *)ether_ipmulticast_min, (char *)addrlo, 6);
			bcopy((char *)ether_ipmulticast_max, (char *)addrhi, 6);
		}
		else {
			ETHER_MAP_IP_MULTICAST(&sin->sin_addr, addrlo);
			bcopy((char *)addrlo, (char *)addrhi, 6);
		}
		break;
#endif

	default:
		splx(s);
		return (EAFNOSUPPORT);
	}

	/*
	 * Look up the address in our list.
	 */
	ETHER_LOOKUP_MULTI(addrlo, addrhi, ac, enm);
	if (enm == NULL) {
		splx(s);
		return (ENXIO);
	}
	if (--enm->enm_refcount != 0) {
		/*
		 * Still some claims to this record.
		 */
		splx(s);
		return (0);
	}
	/*
	 * No remaining claims to this record; unlink and free it.
	 */
	for (p = &enm->enm_ac->ac_multiaddrs;
	     *p != enm;
	     p = &(*p)->enm_next)
		continue;
	*p = (*p)->enm_next;
	FREE(enm, MT_IFMADDR);
	ac->ac_multicnt--;
	splx(s);
	/*
	 * Return ENETRESET to inform the driver that the list has changed
	 * and its reception filter should be adjusted accordingly.
	 */
	return (ENETRESET);
}

/*******************************************************************************
*
* check_trailer - check ethernet frames that have trailers following them
*