if_ethersubr.c

MIPS处理器的bootloader,龙芯就是用的修改过的PMON2

		    sizeof(etherbroadcastaddr)) == 0)
			m->m_flags |= M_BCAST;
		else
			m->m_flags |= M_MCAST;
	}
	if (m->m_flags & (M_BCAST|M_MCAST))
		ifp->if_imcasts++;

#if NBRIDGE > 0
	/*
	 * Tap the packet off here for a bridge, if configured and
	 * active for this interface.  bridge_input returns
	 * NULL if it has consumed the packet, otherwise, it
	 * gets processed as normal.
	 */
	if (ifp->if_bridge) {
		m = bridge_input(ifp, eh, m);
		if (m == NULL)
			return;
		/* The bridge has determined it's for us. */
		goto decapsulate;
	}
#endif
	/*
	 * If packet is unicast and we're in promiscuous mode, make sure it
	 * is for us.  Drop otherwise.
	 */
	if ((m->m_flags & (M_BCAST|M_MCAST)) == 0 &&
	    (ifp->if_flags & IFF_PROMISC)) {
		if (bcmp(ac->ac_enaddr, (caddr_t)eh->ether_dhost,
		    ETHER_ADDR_LEN)) {
			m_freem(m);
			return;
		}
	}

decapsulate:
	etype = ntohs(eh->ether_type);
	switch (etype) {
#ifdef INET
	case ETHERTYPE_IP:
		schednetisr(NETISR_IP);
		inq = &ipintrq;
		break;

	case ETHERTYPE_ARP:
		if (ifp->if_flags & IFF_NOARP)
			goto dropanyway;
		schednetisr(NETISR_ARP);
		inq = &arpintrq;
		break;

	case ETHERTYPE_REVARP:
		if (ifp->if_flags & IFF_NOARP)
			goto dropanyway;
		revarpinput(m);	/* XXX queue? */
		return;

#endif
#ifdef INET6
	/*
	 * Schedule IPv6 software interrupt for incoming IPv6 packet.
	 */
	case ETHERTYPE_IPV6:
		schednetisr(NETISR_IPV6);
		inq = &ipv6intrq;
		break;
#endif /* INET6 */
#ifdef IPX
	case ETHERTYPE_IPX:
		schednetisr(NETISR_IPX);
		inq = &ipxintrq;
		break;
#endif
#ifdef NS
	case ETHERTYPE_NS:
		schednetisr(NETISR_NS);
		inq = &nsintrq;
		break;
#endif
#ifdef NETATALK
	case ETHERTYPE_AT:
		schednetisr(NETISR_ATALK);
		inq = &atintrq1;
		break;
	case ETHERTYPE_AARP:
		/* probably this should be done with a NETISR as well */
		/* XXX queue this */
		aarpinput((struct arpcom *)ifp, m);
		return;
#endif
	default:
		if (llcfound || etype > ETHERMTU)
			goto dropanyway;
		llcfound = 1;
		l = mtod(m, struct llc *);
		switch (l->llc_dsap) {
		case LLC_SNAP_LSAP:
#ifdef NETATALK
			/*
			 * Some protocols (like Appletalk) need special
			 * handling depending on if they are type II
			 * or SNAP encapsulated. Everything else
			 * gets handled by stripping off the SNAP header
			 * and going back up to decapsulate.
			 */
			if (l->llc_control == LLC_UI &&
			    l->llc_ssap == LLC_SNAP_LSAP &&
			    Bcmp(&(l->llc_snap_org_code)[0],
			    at_org_code, sizeof(at_org_code)) == 0 &&
			    ntohs(l->llc_snap_ether_type) == ETHERTYPE_AT) {
				inq = &atintrq2;
				m_adj(m, AT_LLC_SIZE);
				schednetisr(NETISR_ATALK);
				break;
			}

			if (l->llc_control == LLC_UI &&
			    l->llc_ssap == LLC_SNAP_LSAP &&
			    Bcmp(&(l->llc_snap_org_code)[0],
			    aarp_org_code, sizeof(aarp_org_code)) == 0 &&
			    ntohs(l->llc_snap_ether_type) == ETHERTYPE_AARP) {
				m_adj(m, AT_LLC_SIZE);
				/* XXX Really this should use netisr too */
				aarpinput((struct arpcom *)ifp, m);
				return;
			}
#endif /* NETATALK */
			if (l->llc_control == LLC_UI &&
			    l->llc_dsap == LLC_SNAP_LSAP &&
			    l->llc_ssap == LLC_SNAP_LSAP) {
				/* SNAP */
				if (m->m_pkthdr.len > etype)
					m_adj(m, etype - m->m_pkthdr.len);
				m->m_data += 6;		/* XXX */
				m->m_len -= 6;		/* XXX */
				m->m_pkthdr.len -= 6;	/* XXX */
				M_PREPEND(m, sizeof *eh, M_DONTWAIT);
				if (m == 0)
					return;
				*mtod(m, struct ether_header *) = *eh;
				goto decapsulate;
			}
			goto dropanyway;
#ifdef	ISO
		case LLC_ISO_LSAP:
			switch (l->llc_control) {
			case LLC_UI:
				/* LLC_UI_P forbidden in class 1 service */
				if ((l->llc_dsap == LLC_ISO_LSAP) &&
				    (l->llc_ssap == LLC_ISO_LSAP)) {
					/* LSAP for ISO */
					if (m->m_pkthdr.len > etype)
						m_adj(m, etype - m->m_pkthdr.len);
					m->m_data += 3;		/* XXX */
					m->m_len -= 3;		/* XXX */
					m->m_pkthdr.len -= 3;	/* XXX */
					M_PREPEND(m, sizeof *eh, M_DONTWAIT);
					if (m == 0)
						return;
					*mtod(m, struct ether_header *) = *eh;
#ifdef ARGO_DEBUG
					if (argo_debug[D_ETHER])
						printf("clnp packet");
#endif
					schednetisr(NETISR_ISO);
					inq = &clnlintrq;
					break;
				}
				goto dropanyway;

			case LLC_XID:
			case LLC_XID_P:
				if(m->m_len < 6)
					goto dropanyway;
				l->llc_window = 0;
				l->llc_fid = 9;
				l->llc_class = 1;
				l->llc_dsap = l->llc_ssap = 0;
				/* Fall through to */
			case LLC_TEST:
			case LLC_TEST_P:
			{
				struct sockaddr sa;
				register struct ether_header *eh2;
				int i;
				u_char c = l->llc_dsap;

				l->llc_dsap = l->llc_ssap;
				l->llc_ssap = c;
				if (m->m_flags & (M_BCAST | M_MCAST))
					bcopy(ac->ac_enaddr,
					    eh->ether_dhost, 6);
				sa.sa_family = AF_UNSPEC;
				sa.sa_len = sizeof(sa);
				eh2 = (struct ether_header *)sa.sa_data;
				for (i = 0; i < 6; i++) {
					eh2->ether_shost[i] = c = eh->ether_dhost[i];
					eh2->ether_dhost[i] =
						eh->ether_dhost[i] = eh->ether_shost[i];
					eh->ether_shost[i] = c;
				}
				ifp->if_output(ifp, m, &sa, NULL);
				return;
			}
			break;
			}
#endif /* ISO */
#ifdef CCITT
		case LLC_X25_LSAP:
			if (m->m_pkthdr.len > etype)
				m_adj(m, etype - m->m_pkthdr.len);
			M_PREPEND(m, sizeof(struct sdl_hdr) , M_DONTWAIT);
			if (m == 0)
				return;
			if (!sdl_sethdrif(ifp, eh->ether_shost, LLC_X25_LSAP,
			    eh->ether_dhost, LLC_X25_LSAP, 6,
			    mtod(m, struct sdl_hdr *)))
				panic("ETHER cons addr failure");
			mtod(m, struct sdl_hdr *)->sdlhdr_len = etype;
#ifdef LLC_DEBUG
			printf("llc packet\n");
#endif /* LLC_DEBUG */
			schednetisr(NETISR_CCITT);
			inq = &llcintrq;
			break;
#endif /* CCITT */
		dropanyway:
		default:
			m_freem(m);
			return;
		}
	}

	s = splimp();
	if (IF_QFULL(inq)) {
		IF_DROP(inq);
		m_freem(m);
	} else
		IF_ENQUEUE(inq, m);
	splx(s);
}

/*
 * Convert Ethernet address to printable (loggable) representation.
 */
static char digits[] = "0123456789abcdef";
char *
ether_sprintf(ap)
	register u_char *ap;
{
	register int i;
	static char etherbuf[18];
	register char *cp = etherbuf;

	for (i = 0; i < 6; i++) {
		*cp++ = digits[*ap >> 4];
		*cp++ = digits[*ap++ & 0xf];
		*cp++ = ':';
	}
	*--cp = 0;
	return (etherbuf);
}

/*
 * 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;
	ifp->if_output = ether_output;
	for (ifa = ifp->if_addrlist.tqh_first; ifa != 0;
	    ifa = ifa->ifa_list.tqe_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;
		}
	LIST_INIT(&((struct arpcom *)ifp)->ac_multiaddrs);
}

void
ether_ifdetach(ifp)
	struct ifnet *ifp;
{
	struct arpcom *ac = (struct arpcom *)ifp;
	struct ether_multi *enm;

	for (enm = LIST_FIRST(&ac->ac_multiaddrs); enm;
	    enm = LIST_FIRST(&ac->ac_multiaddrs)) {
		LIST_REMOVE(enm, enm_list);
		free(enm, M_IFMADDR);
	}
}

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

#ifdef INET6
u_char	ether_ipv6multicast_min[6] = { 0x33, 0x33, 0x00, 0x00, 0x00, 0x00 };
u_char	ether_ipv6multicast_max[6] = { 0x33, 0x33, 0xff, 0xff, 0xff, 0xff };
#endif /* INET6 */

/*
 * 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;
#ifdef INET6
	struct sockaddr_in6 *sin6;
#endif /* INET6 */
	u_char addrlo[6];
	u_char addrhi[6];
	int s = splimp();

	switch (ifr->ifr_addr.sa_family) {

	case AF_UNSPEC:
		bcopy(ifr->ifr_addr.sa_data, addrlo, 6);
		bcopy(addrlo, 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(ether_ipmulticast_min, addrlo, 6);
			bcopy(ether_ipmulticast_max, addrhi, 6);
		}
		else {
			ETHER_MAP_IP_MULTICAST(&sin->sin_addr, addrlo);
			bcopy(addrlo, addrhi, 6);
		}
		break;
#endif
#ifdef INET6
	case AF_INET6:
		sin6 = (struct sockaddr_in6 *)&(ifr->ifr_addr);
		if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
			/*
			 * An unspecified IPv6 address means listen to all
			 * of the IPv6 multicast addresses on this Ethernet.
			 * (Multicast routers like this.)
			 */
			bcopy(ether_ipv6multicast_min, addrlo, ETHER_ADDR_LEN);
			bcopy(ether_ipv6multicast_max, addrhi, ETHER_ADDR_LEN);
		} else {
			ETHER_MAP_IN6_MULTICAST(sin6->sin6_addr, addrlo);
			bcopy(addrlo, addrhi, ETHER_ADDR_LEN);
		}
		break;
#endif /* INET6 */

	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.
	 */
	enm = (struct ether_multi *)malloc(sizeof(*enm), M_IFMADDR, M_NOWAIT);
	if (enm == NULL) {
		splx(s);
		return (ENOBUFS);
	}
	bcopy(addrlo, enm->enm_addrlo, 6);
	bcopy(addrhi, enm->enm_addrhi, 6);
	enm->enm_ac = ac;
	enm->enm_refcount = 1;
	LIST_INSERT_HEAD(&ac->ac_multiaddrs, enm, enm_list);
	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;
	struct sockaddr_in *sin;
#ifdef INET6
	struct sockaddr_in6 *sin6;
#endif /* INET6 */
	u_char addrlo[6];
	u_char addrhi[6];
	int s = splimp();

	switch (ifr->ifr_addr.sa_family) {

	case AF_UNSPEC:
		bcopy(ifr->ifr_addr.sa_data, addrlo, 6);
		bcopy(addrlo, 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(ether_ipmulticast_min, addrlo, 6);
			bcopy(ether_ipmulticast_max, addrhi, 6);
		}
		else {
			ETHER_MAP_IP_MULTICAST(&sin->sin_addr, addrlo);
			bcopy(addrlo, addrhi, 6);
		}
		break;
#endif
#ifdef INET6
	case AF_INET6:
		sin6 = (struct sockaddr_in6 *)&(ifr->ifr_addr);
		if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
			/*
			 * An unspecified IPv6 address means stop listening to
			 * all IPv6 multicast addresses on this Ethernet.'
			 *
			 * (This might not be healthy, given IPv6's reliance on
			 * multicast for things like neighbor discovery.
			 * Perhaps initializing all-nodes, solicited nodes, and
			 * possibly all-routers for this interface afterwards
			 * is not a bad idea.)
			 */
			bcopy(ether_ipv6multicast_min, addrlo, ETHER_ADDR_LEN);
			bcopy(ether_ipv6multicast_max, addrhi, ETHER_ADDR_LEN);
		} else {
			ETHER_MAP_IN6_MULTICAST(sin6->sin6_addr, addrlo);
			bcopy(addrlo, addrhi, ETHER_ADDR_LEN);
		}
		break;
#endif /* INET6 */

	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.
	 */
	LIST_REMOVE(enm, enm_list);
	free(enm, M_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);
}