Return after calling bridge_ouput_p.

[dragonfly.git] / sys / net / if_ethersubr.c

/*
 * 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
 * $FreeBSD: src/sys/net/if_ethersubr.c,v 1.70.2.33 2003/04/28 15:45:53 archie Exp $
 * $DragonFly: src/sys/net/if_ethersubr.c,v 1.61 2008/05/18 04:38:44 sephe Exp $
 */

#include "opt_atalk.h"
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_ipx.h"
#include "opt_netgraph.h"
#include "opt_carp.h"
#include "opt_ethernet.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/globaldata.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/msgport.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/sysctl.h>
#include <sys/thread.h>
#include <sys/thread2.h>

#include <net/if.h>
#include <net/netisr.h>
#include <net/route.h>
#include <net/if_llc.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/ifq_var.h>
#include <net/bpf.h>
#include <net/ethernet.h>
#include <net/vlan/if_vlan_ether.h>

#if defined(INET) || defined(INET6)
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/if_ether.h>
#include <net/ipfw/ip_fw.h>
#include <net/dummynet/ip_dummynet.h>
#endif
#ifdef INET6
#include <netinet6/nd6.h>
#endif

#ifdef CARP
#include <netinet/ip_carp.h>
#endif

#ifdef IPX
#include <netproto/ipx/ipx.h>
#include <netproto/ipx/ipx_if.h>
int (*ef_inputp)(struct ifnet*, const struct ether_header *eh, struct mbuf *m);
int (*ef_outputp)(struct ifnet *ifp, struct mbuf **mp, struct sockaddr *dst,
                  short *tp, int *hlen);
#endif

#ifdef NS
#include <netns/ns.h>
#include <netns/ns_if.h>
ushort ns_nettype;
int ether_outputdebug = 0;
int ether_inputdebug = 0;
#endif

#ifdef NETATALK
#include <netproto/atalk/at.h>
#include <netproto/atalk/at_var.h>
#include <netproto/atalk/at_extern.h>

#define llc_snap_org_code       llc_un.type_snap.org_code
#define llc_snap_ether_type     llc_un.type_snap.ether_type

extern u_char   at_org_code[3];
extern u_char   aarp_org_code[3];
#endif /* NETATALK */

/* netgraph node hooks for ng_ether(4) */
void    (*ng_ether_input_p)(struct ifnet *ifp, struct mbuf **mp);
void    (*ng_ether_input_orphan_p)(struct ifnet *ifp,
                struct mbuf *m, const struct ether_header *eh);
int     (*ng_ether_output_p)(struct ifnet *ifp, struct mbuf **mp);
void    (*ng_ether_attach_p)(struct ifnet *ifp);
void    (*ng_ether_detach_p)(struct ifnet *ifp);

int     (*vlan_input_p)(struct mbuf *, struct mbuf_chain *);

static int ether_output(struct ifnet *, struct mbuf *, struct sockaddr *,
                        struct rtentry *);
static void ether_restore_header(struct mbuf **, const struct ether_header *,
                                 const struct ether_header *);
static void ether_demux_chain(struct ifnet *, struct mbuf *,
                              struct mbuf_chain *);

/*
 * if_bridge support
 */
struct mbuf *(*bridge_input_p)(struct ifnet *, struct mbuf *);
int (*bridge_output_p)(struct ifnet *, struct mbuf *,
                       struct sockaddr *, struct rtentry *);
void (*bridge_dn_p)(struct mbuf *, struct ifnet *);

static int ether_resolvemulti(struct ifnet *, struct sockaddr **,
                              struct sockaddr *);

const uint8_t etherbroadcastaddr[ETHER_ADDR_LEN] = {
        0xff, 0xff, 0xff, 0xff, 0xff, 0xff
};

#define gotoerr(e) do { error = (e); goto bad; } while (0)
#define IFP2AC(ifp) ((struct arpcom *)(ifp))

static boolean_t ether_ipfw_chk(struct mbuf **m0, struct ifnet *dst,
                                struct ip_fw **rule,
                                const struct ether_header *eh);

static int ether_ipfw;
static u_int ether_restore_hdr;
static u_int ether_prepend_hdr;

SYSCTL_DECL(_net_link);
SYSCTL_NODE(_net_link, IFT_ETHER, ether, CTLFLAG_RW, 0, "Ethernet");
SYSCTL_INT(_net_link_ether, OID_AUTO, ipfw, CTLFLAG_RW,
           &ether_ipfw, 0, "Pass ether pkts through firewall");
SYSCTL_UINT(_net_link_ether, OID_AUTO, restore_hdr, CTLFLAG_RW,
            &ether_restore_hdr, 0, "# of ether header restoration");
SYSCTL_UINT(_net_link_ether, OID_AUTO, prepend_hdr, CTLFLAG_RW,
            &ether_prepend_hdr, 0,
            "# of ether header restoration which prepends mbuf");

/*
 * 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.
 */
static int
ether_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
             struct rtentry *rt)
{
        struct ether_header *eh, *deh;
        u_char *edst;
        int loop_copy = 0;
        int hlen = ETHER_HDR_LEN;       /* link layer header length */
        struct arpcom *ac = IFP2AC(ifp);
        int error;

        if (ifp->if_flags & IFF_MONITOR)
                gotoerr(ENETDOWN);
        if ((ifp->if_flags & (IFF_UP | IFF_RUNNING)) != (IFF_UP | IFF_RUNNING))
                gotoerr(ENETDOWN);

        M_PREPEND(m, sizeof(struct ether_header), MB_DONTWAIT);
        if (m == NULL)
                return (ENOBUFS);
        eh = mtod(m, struct ether_header *);
        edst = eh->ether_dhost;

        /*
         * Fill in the destination ethernet address and frame type.
         */
        switch (dst->sa_family) {
#ifdef INET
        case AF_INET:
                if (!arpresolve(ifp, rt, m, dst, edst))
                        return (0);     /* if not yet resolved */
                eh->ether_type = htons(ETHERTYPE_IP);
                break;
#endif
#ifdef INET6
        case AF_INET6:
                if (!nd6_storelladdr(&ac->ac_if, rt, m, dst, edst))
                        return (0);             /* Something bad happenned. */
                eh->ether_type = htons(ETHERTYPE_IPV6);
                break;
#endif
#ifdef IPX
        case AF_IPX:
                if (ef_outputp != NULL) {
                        error = ef_outputp(ifp, &m, dst, &eh->ether_type,
                                           &hlen);
                        if (error)
                                goto bad;
                } else {
                        eh->ether_type = htons(ETHERTYPE_IPX);
                        bcopy(&(((struct sockaddr_ipx *)dst)->sipx_addr.x_host),
                              edst, ETHER_ADDR_LEN);
                }
                break;
#endif
#ifdef NETATALK
        case AF_APPLETALK: {
                struct at_ifaddr *aa;

                if ((aa = at_ifawithnet((struct sockaddr_at *)dst)) == NULL) {
                        error = 0;      /* XXX */
                        goto bad;
                }
                /*
                 * In the phase 2 case, need to prepend an mbuf for
                 * the llc header.  Since we must preserve the value
                 * of m, which is passed to us by value, we m_copy()
                 * the first mbuf, and use it for our llc header.
                 */
                if (aa->aa_flags & AFA_PHASE2) {
                        struct llc llc;

                        M_PREPEND(m, sizeof(struct llc), MB_DONTWAIT);
                        eh = mtod(m, struct ether_header *);
                        edst = eh->ether_dhost;
                        llc.llc_dsap = llc.llc_ssap = LLC_SNAP_LSAP;
                        llc.llc_control = LLC_UI;
                        bcopy(at_org_code, llc.llc_snap_org_code,
                              sizeof at_org_code);
                        llc.llc_snap_ether_type = htons(ETHERTYPE_AT);
                        bcopy(&llc,
                              mtod(m, caddr_t) + sizeof(struct ether_header),
                              sizeof(struct llc));
                        eh->ether_type = htons(m->m_pkthdr.len);
                        hlen = sizeof(struct llc) + ETHER_HDR_LEN;
                } else {
                        eh->ether_type = htons(ETHERTYPE_AT);
                }
                if (!aarpresolve(ac, m, (struct sockaddr_at *)dst, edst))
                        return (0);
                break;
          }
#endif
#ifdef NS
        case AF_NS:
                switch(ns_nettype) {
                default:
                case 0x8137:    /* Novell Ethernet_II Ethernet TYPE II */
                        eh->ether_type = 0x8137;
                        break;
                case 0x0:       /* Novell 802.3 */
                        eh->ether_type = htons(m->m_pkthdr.len);
                        break;
                case 0xe0e0:    /* Novell 802.2 and Token-Ring */
                        M_PREPEND(m, 3, MB_DONTWAIT);
                        eh = mtod(m, struct ether_header *);
                        edst = eh->ether_dhost;
                        eh->ether_type = htons(m->m_pkthdr.len);
                        cp = mtod(m, u_char *) + sizeof(struct ether_header);
                        *cp++ = 0xE0;
                        *cp++ = 0xE0;
                        *cp++ = 0x03;
                        break;
                }
                bcopy(&(((struct sockaddr_ns *)dst)->sns_addr.x_host), edst,
                      ETHER_ADDR_LEN);
                /*
                 * XXX if ns_thishost is the same as the node's ethernet
                 * address then just the default code will catch this anyhow.
                 * So I'm not sure if this next clause should be here at all?
                 * [JRE]
                 */
                if (bcmp(edst, &ns_thishost, ETHER_ADDR_LEN) == 0) {
                        m->m_pkthdr.rcvif = ifp;
                        netisr_dispatch(NETISR_NS, m);
                        return (error);
                }
                if (bcmp(edst, &ns_broadhost, ETHER_ADDR_LEN) == 0)
                        m->m_flags |= M_BCAST;
                break;
#endif
        case pseudo_AF_HDRCMPLT:
        case AF_UNSPEC:
                loop_copy = -1; /* if this is for us, don't do it */
                deh = (struct ether_header *)dst->sa_data;
                memcpy(edst, deh->ether_dhost, ETHER_ADDR_LEN);
                eh->ether_type = deh->ether_type;
                break;

        default:
                if_printf(ifp, "can't handle af%d\n", dst->sa_family);
                gotoerr(EAFNOSUPPORT);
        }

        if (dst->sa_family == pseudo_AF_HDRCMPLT)       /* unlikely */
                memcpy(eh->ether_shost,
                       ((struct ether_header *)dst->sa_data)->ether_shost,
                       ETHER_ADDR_LEN);
        else
                memcpy(eh->ether_shost, ac->ac_enaddr, ETHER_ADDR_LEN);

        /*
         * Bridges require special output handling.
         */
        if (ifp->if_bridge) {
                KASSERT(bridge_output_p != NULL,
                        ("%s: if_bridge not loaded!", __func__));
                lwkt_serialize_enter(ifp->if_serializer);
                error = bridge_output_p(ifp, m, NULL, NULL);
                lwkt_serialize_exit(ifp->if_serializer);
                return error;
        }

        /*
         * If a simplex interface, and the packet is being sent to our
         * Ethernet address or a broadcast address, loopback a copy.
         * XXX To make a simplex device behave exactly like a duplex
         * device, we should copy in the case of sending to our own
         * ethernet address (thus letting the original actually appear
         * on the wire). However, we don't do that here for security
         * reasons and compatibility with the original behavior.
         */
        if ((ifp->if_flags & IFF_SIMPLEX) && (loop_copy != -1)) {
                int csum_flags = 0;

                if (m->m_pkthdr.csum_flags & CSUM_IP)
                        csum_flags |= (CSUM_IP_CHECKED | CSUM_IP_VALID);
                if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA)
                        csum_flags |= (CSUM_DATA_VALID | CSUM_PSEUDO_HDR);
                if ((m->m_flags & M_BCAST) || (loop_copy > 0)) {
                        struct mbuf *n;

                        if ((n = m_copypacket(m, MB_DONTWAIT)) != NULL) {
                                n->m_pkthdr.csum_flags |= csum_flags;
                                if (csum_flags & CSUM_DATA_VALID)
                                        n->m_pkthdr.csum_data = 0xffff;
                                if_simloop(ifp, n, dst->sa_family, hlen);
                        } else
                                ifp->if_iqdrops++;
                } else if (bcmp(eh->ether_dhost, eh->ether_shost,
                                ETHER_ADDR_LEN) == 0) {
                        m->m_pkthdr.csum_flags |= csum_flags;
                        if (csum_flags & CSUM_DATA_VALID)
                                m->m_pkthdr.csum_data = 0xffff;
                        if_simloop(ifp, m, dst->sa_family, hlen);
                        return (0);     /* XXX */
                }
        }

#ifdef CARP
        if (ifp->if_carp && (error = carp_output(ifp, m, dst, NULL)))
                goto bad;
#endif
 

        /* Handle ng_ether(4) processing, if any */
        if (ng_ether_output_p != NULL) {
                if ((error = (*ng_ether_output_p)(ifp, &m)) != 0)
                        goto bad;
                if (m == NULL)
                        return (0);
        }

        /* Continue with link-layer output */
        return ether_output_frame(ifp, m);

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

/*
 * Ethernet link layer output routine to send a raw frame to the device.
 *
 * This assumes that the 14 byte Ethernet header is present and contiguous
 * in the first mbuf.
 */
int
ether_output_frame(struct ifnet *ifp, struct mbuf *m)
{
        struct ip_fw *rule = NULL;
        int error = 0;
        struct altq_pktattr pktattr;
        struct m_tag *mtag;

        /* Extract info from dummynet tag */
        mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL);
        if (mtag != NULL) {
                rule = ((struct dn_pkt *)m_tag_data(mtag))->dn_priv;

                m_tag_delete(m, mtag);
                mtag = NULL;
        }

        if (ifq_is_enabled(&ifp->if_snd))
                altq_etherclassify(&ifp->if_snd, m, &pktattr);
        crit_enter();
        if (IPFW_LOADED && ether_ipfw != 0) {
                struct ether_header save_eh, *eh;

                eh = mtod(m, struct ether_header *);
                save_eh = *eh;
                m_adj(m, ETHER_HDR_LEN);
                if (!ether_ipfw_chk(&m, ifp, &rule, eh)) {
                        crit_exit();
                        if (m != NULL) {
                                m_freem(m);
                                return ENOBUFS; /* pkt dropped */
                        } else
                                return 0;       /* consumed e.g. in a pipe */
                }

                /* packet was ok, restore the ethernet header */
                ether_restore_header(&m, eh, &save_eh);
                if (m == NULL) {
                        crit_exit();
                        return ENOBUFS;
                }
        }
        crit_exit();

        /*
         * Queue message on interface, update output statistics if
         * successful, and start output if interface not yet active.
         */
        error = ifq_dispatch(ifp, m, &pktattr);
        return (error);
}

/*
 * ipfw processing for ethernet packets (in and out).
 * The second parameter is NULL from ether_demux(), and ifp from
 * ether_output_frame().
 */
static boolean_t
ether_ipfw_chk(struct mbuf **m0, struct ifnet *dst, struct ip_fw **rule,
               const struct ether_header *eh)
{
        struct ether_header save_eh = *eh;      /* might be a ptr in m */
        struct ip_fw_args args;
        struct m_tag *mtag;
        int i;

        if (*rule != NULL && fw_one_pass)
                return TRUE; /* dummynet packet, already partially processed */

        /*
         * I need some amount of data to be contiguous.
         */
        i = min((*m0)->m_pkthdr.len, max_protohdr);
        if ((*m0)->m_len < i) {
                *m0 = m_pullup(*m0, i);
                if (*m0 == NULL)
                        return FALSE;
        }

        args.m = *m0;           /* the packet we are looking at         */
        args.oif = dst;         /* destination, if any                  */
        if ((mtag = m_tag_find(*m0, PACKET_TAG_IPFW_DIVERT, NULL)) != NULL)
                m_tag_delete(*m0, mtag);
        args.rule = *rule;      /* matching rule to restart             */
        args.next_hop = NULL;   /* we do not support forward yet        */
        args.eh = &save_eh;     /* MAC header for bridged/MAC packets   */
        i = ip_fw_chk_ptr(&args);
        *m0 = args.m;
        *rule = args.rule;

        if ((i & IP_FW_PORT_DENY_FLAG) || *m0 == NULL)  /* drop */
                return FALSE;

        if (i == 0)                                     /* a PASS rule.  */
                return TRUE;

        if (i & IP_FW_PORT_DYNT_FLAG) {
                /*
                 * Pass the pkt to dummynet, which consumes it.
                 */
                struct mbuf *m;

                m = *m0;        /* pass the original to dummynet */
                *m0 = NULL;     /* and nothing back to the caller */

                ether_restore_header(&m, eh, &save_eh);
                if (m == NULL)
                        return FALSE;

                ip_fw_dn_io_ptr(m, (i & 0xffff),
                        dst ? DN_TO_ETH_OUT: DN_TO_ETH_DEMUX, &args);
                return FALSE;
        }
        /*
         * XXX at some point add support for divert/forward actions.
         * If none of the above matches, we have to drop the pkt.
         */
        return FALSE;
}

/*
 * Process a received Ethernet packet.
 *
 * The ethernet header is assumed to be in the mbuf so the caller
 * MUST MAKE SURE that there are at least sizeof(struct ether_header)
 * bytes in the first mbuf.
 *
 * This allows us to concentrate in one place a bunch of code which
 * is replicated in all device drivers. Also, many functions called
 * from ether_input() try to put the eh back into the mbuf, so we
 * can later propagate the 'contiguous packet' interface to them.
 *
 * NOTA BENE: for all drivers "eh" is a pointer into the first mbuf or
 * cluster, right before m_data. So be very careful when working on m,
 * as you could destroy *eh !!
 *
 * First we perform any link layer operations, then continue to the
 * upper layers with ether_demux().
 */
void
ether_input_chain(struct ifnet *ifp, struct mbuf *m, struct mbuf_chain *chain)
{
        struct ether_header *eh;

        ASSERT_SERIALIZED(ifp->if_serializer);
        M_ASSERTPKTHDR(m);

        /* Discard packet if interface is not up */
        if (!(ifp->if_flags & IFF_UP)) {
                m_freem(m);
                return;
        }

        if (m->m_len < sizeof(struct ether_header)) {
                /* XXX error in the caller. */
                m_freem(m);
                return;
        }
        eh = mtod(m, struct ether_header *);

        if (ntohs(eh->ether_type) == ETHERTYPE_VLAN &&
            (m->m_flags & M_VLANTAG) == 0) {
                /*
                 * Extract vlan tag if hardware does not do it for us
                 */
                vlan_ether_decap(&m);
                if (m == NULL)
                        return;
                eh = mtod(m, struct ether_header *);
        }

        m->m_pkthdr.rcvif = ifp;

        if (ETHER_IS_MULTICAST(eh->ether_dhost)) {
                if (bcmp(ifp->if_broadcastaddr, eh->ether_dhost,
                         ifp->if_addrlen) == 0)
                        m->m_flags |= M_BCAST;
                else
                        m->m_flags |= M_MCAST;
                ifp->if_imcasts++;
        }

        ETHER_BPF_MTAP(ifp, m);

        ifp->if_ibytes += m->m_pkthdr.len;

        if (ifp->if_flags & IFF_MONITOR) {
                /*
                 * Interface marked for monitoring; discard packet.
                 */
                 m_freem(m);
                 return;
        }

        /*
         * Tap the packet off here for a bridge.  bridge_input()
         * will return NULL if it has consumed the packet, otherwise
         * it gets processed as normal.  Note that bridge_input()
         * will always return the original packet if we need to
         * process it locally.
         */
        if (ifp->if_bridge) {
                KASSERT(bridge_input_p != NULL,
                        ("%s: if_bridge not loaded!", __func__));

                if(m->m_flags & M_PROTO1) {
                        m->m_flags &= ~M_PROTO1;
                } else {
                        /* clear M_PROMISC, in case the packets comes from a vlan */
                        /* m->m_flags &= ~M_PROMISC; */
                        lwkt_serialize_exit(ifp->if_serializer);
                        m = (*bridge_input_p)(ifp, m);
                        lwkt_serialize_enter(ifp->if_serializer);
                        if (m == NULL)
                                return;

                        KASSERT(ifp == m->m_pkthdr.rcvif,
                                ("bridge_input_p changed rcvif\n"));

                        /* 'm' may be changed by bridge_input_p() */
                        eh = mtod(m, struct ether_header *);
                }
        }

        /* Handle ng_ether(4) processing, if any */
        if (ng_ether_input_p != NULL) {
                ng_ether_input_p(ifp, &m);
                if (m == NULL)
                        return;

                /* 'm' may be changed by ng_ether_input_p() */
                eh = mtod(m, struct ether_header *);
        }

        /* Continue with upper layer processing */
        ether_demux_chain(ifp, m, chain);
}

void
ether_input(struct ifnet *ifp, struct mbuf *m)
{
        ether_input_chain(ifp, m, NULL);
}

/*
 * Upper layer processing for a received Ethernet packet.
 */
static void
ether_demux_chain(struct ifnet *ifp, struct mbuf *m, struct mbuf_chain *chain)
{
        struct ether_header save_eh, *eh;
        int isr;
        u_short ether_type;
        struct ip_fw *rule = NULL;
        struct m_tag *mtag;
#ifdef NETATALK
        struct llc *l;
#endif

        M_ASSERTPKTHDR(m);
        KASSERT(m->m_len >= ETHER_HDR_LEN,
                ("ether header is no contiguous!\n"));

        eh = mtod(m, struct ether_header *);
        save_eh = *eh;

        /* XXX old crufty stuff, needs to be removed */
        m_adj(m, sizeof(struct ether_header));

        /* Extract info from dummynet tag */
        mtag = m_tag_find(m, PACKET_TAG_DUMMYNET, NULL);
        if (mtag != NULL) {
                rule = ((struct dn_pkt *)m_tag_data(mtag))->dn_priv;
                KKASSERT(ifp == NULL);
                ifp = m->m_pkthdr.rcvif;

                m_tag_delete(m, mtag);
                mtag = NULL;
        }
        if (rule)       /* packet is passing the second time */
                goto post_stats;

#ifdef CARP
        /*
         * XXX: Okay, we need to call carp_forus() and - if it is for
         * us jump over code that does the normal check
         * "ac_enaddr == ether_dhost". The check sequence is a bit
         * different from OpenBSD, so we jump over as few code as
         * possible, to catch _all_ sanity checks. This needs
         * evaluation, to see if the carp ether_dhost values break any
         * of these checks!
         */
        if (ifp->if_carp && carp_forus(ifp->if_carp, eh->ether_dhost))
                goto post_stats;
#endif

        /*
         * Discard packet if upper layers shouldn't see it because
         * it was unicast to a different Ethernet address.  If the
         * driver is working properly, then this situation can only
         * happen when the interface is in promiscuous mode.
         */
        if (((ifp->if_flags & (IFF_PROMISC | IFF_PPROMISC)) == IFF_PROMISC) &&
            (eh->ether_dhost[0] & 1) == 0 &&
            bcmp(eh->ether_dhost, IFP2AC(ifp)->ac_enaddr, ETHER_ADDR_LEN)) {
                m_freem(m);
                return;
        }

post_stats:
        if (IPFW_LOADED && ether_ipfw != 0) {
                if (!ether_ipfw_chk(&m, NULL, &rule, eh)) {
                        m_freem(m);
                        return;
                }
        }

        ether_type = ntohs(save_eh.ether_type);

        if (m->m_flags & M_VLANTAG) {
                if (ether_type == ETHERTYPE_VLAN) {
                        /*
                         * To prevent possible dangerous recursion,
                         * we don't do vlan-in-vlan
                         */
                        m->m_pkthdr.rcvif->if_noproto++;
                        m_freem(m);
                }

                if (vlan_input_p != NULL) {
                        ether_restore_header(&m, eh, &save_eh);
                        if (m != NULL)
                                vlan_input_p(m, chain);
                } else {
                        m->m_pkthdr.rcvif->if_noproto++;
                        m_freem(m);
                }
                return;
        }
        KKASSERT(ether_type != ETHERTYPE_VLAN);

        switch (ether_type) {
#ifdef INET
        case ETHERTYPE_IP:
                if (ipflow_fastforward(m, ifp->if_serializer))
                        return;
                isr = NETISR_IP;
                break;

        case ETHERTYPE_ARP:
                if (ifp->if_flags & IFF_NOARP) {
                        /* Discard packet if ARP is disabled on interface */
                        m_freem(m);
                        return;
                }
                isr = NETISR_ARP;
                break;
#endif

#ifdef INET6
        case ETHERTYPE_IPV6:
                isr = NETISR_IPV6;
                break;
#endif

#ifdef IPX
        case ETHERTYPE_IPX:
                if (ef_inputp && ef_inputp(ifp, &save_eh, m) == 0)
                        return;
                isr = NETISR_IPX;
                break;
#endif

#ifdef NS
        case 0x8137: /* Novell Ethernet_II Ethernet TYPE II */
                isr = NETISR_NS;
                break;

#endif

#ifdef NETATALK
        case ETHERTYPE_AT:
                isr = NETISR_ATALK1;
                break;
        case ETHERTYPE_AARP:
                isr = NETISR_AARP;
                break;
#endif

        default:
#ifdef IPX
                if (ef_inputp && ef_inputp(ifp, &save_eh, m) == 0)
                        return;
#endif
#ifdef NS
                checksum = mtod(m, ushort *);
                /* Novell 802.3 */
                if ((ether_type <= ETHERMTU) &&
                    ((*checksum == 0xffff) || (*checksum == 0xE0E0))) {
                        if (*checksum == 0xE0E0) {
                                m->m_pkthdr.len -= 3;
                                m->m_len -= 3;
                                m->m_data += 3;
                        }
                        isr = NETISR_NS;
                        break;
                }
#endif
#ifdef NETATALK
                if (ether_type > ETHERMTU)
                        goto dropanyway;
                l = mtod(m, struct llc *);
                if (l->llc_dsap == LLC_SNAP_LSAP &&
                    l->llc_ssap == LLC_SNAP_LSAP &&
                    l->llc_control == LLC_UI) {
                        if (bcmp(&(l->llc_snap_org_code)[0], at_org_code,
                                 sizeof at_org_code) == 0 &&
                            ntohs(l->llc_snap_ether_type) == ETHERTYPE_AT) {
                                m_adj(m, sizeof(struct llc));
                                isr = NETISR_ATALK2;
                                break;
                        }
                        if (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, sizeof(struct llc));
                                isr = NETISR_AARP;
                                break;
                        }
                }
dropanyway:
#endif
                if (ng_ether_input_orphan_p != NULL)
                        (*ng_ether_input_orphan_p)(ifp, m, &save_eh);
                else
                        m_freem(m);
                return;
        }

#ifdef ETHER_INPUT_CHAIN
        if (chain != NULL) {
                struct mbuf_chain *c;
                lwkt_port_t port;
                int cpuid;

                port = netisr_mport(isr, &m);
                if (port == NULL)
                        return;

                m->m_pkthdr.header = port; /* XXX */
                cpuid = port->mpu_td->td_gd->gd_cpuid;

                c = &chain[cpuid];
                if (c->mc_head == NULL) {
                        c->mc_head = c->mc_tail = m;
                } else {
                        c->mc_tail->m_nextpkt = m;
                        c->mc_tail = m;
                }
                m->m_nextpkt = NULL;
        } else
#endif  /* ETHER_INPUT_CHAIN */
                netisr_dispatch(isr, m);
}

void
ether_demux(struct ifnet *ifp, struct mbuf *m)
{
        ether_demux_chain(ifp, m, NULL);
}

/*
 * Perform common duties while attaching to interface list
 */

void
ether_ifattach(struct ifnet *ifp, uint8_t *lla, lwkt_serialize_t serializer)
{
        ether_ifattach_bpf(ifp, lla, DLT_EN10MB, sizeof(struct ether_header),
                           serializer);
}

void
ether_ifattach_bpf(struct ifnet *ifp, uint8_t *lla, u_int dlt, u_int hdrlen,
                   lwkt_serialize_t serializer)
{
        struct sockaddr_dl *sdl;

        ifp->if_type = IFT_ETHER;
        ifp->if_addrlen = ETHER_ADDR_LEN;
        ifp->if_hdrlen = ETHER_HDR_LEN;
        if_attach(ifp, serializer);
        ifp->if_mtu = ETHERMTU;
        if (ifp->if_baudrate == 0)
                ifp->if_baudrate = 10000000;
        ifp->if_output = ether_output;
        ifp->if_input = ether_input;
        ifp->if_resolvemulti = ether_resolvemulti;
        ifp->if_broadcastaddr = etherbroadcastaddr;
        sdl = IF_LLSOCKADDR(ifp);
        sdl->sdl_type = IFT_ETHER;
        sdl->sdl_alen = ifp->if_addrlen;
        bcopy(lla, LLADDR(sdl), ifp->if_addrlen);
        /*
         * XXX Keep the current drivers happy.
         * XXX Remove once all drivers have been cleaned up
         */
        if (lla != IFP2AC(ifp)->ac_enaddr)
                bcopy(lla, IFP2AC(ifp)->ac_enaddr, ifp->if_addrlen);
        bpfattach(ifp, dlt, hdrlen);
        if (ng_ether_attach_p != NULL)
                (*ng_ether_attach_p)(ifp);

        if_printf(ifp, "MAC address: %6D\n", lla, ":");
}

/*
 * Perform common duties while detaching an Ethernet interface
 */
void
ether_ifdetach(struct ifnet *ifp)
{
        if_down(ifp);

        if (ng_ether_detach_p != NULL)
                (*ng_ether_detach_p)(ifp);
        bpfdetach(ifp);
        if_detach(ifp);
}

int
ether_ioctl(struct ifnet *ifp, int command, caddr_t data)
{
        struct ifaddr *ifa = (struct ifaddr *) data;
        struct ifreq *ifr = (struct ifreq *) data;
        int error = 0;

#define IF_INIT(ifp) \
do { \
        if (((ifp)->if_flags & IFF_UP) == 0) { \
                (ifp)->if_flags |= IFF_UP; \
                (ifp)->if_init((ifp)->if_softc); \
        } \
} while (0)

        ASSERT_SERIALIZED(ifp->if_serializer);

        switch (command) {
        case SIOCSIFADDR:
                switch (ifa->ifa_addr->sa_family) {
#ifdef INET
                case AF_INET:
                        IF_INIT(ifp);   /* before arpwhohas */
                        arp_ifinit(ifp, ifa);
                        break;
#endif
#ifdef IPX
                /*
                 * XXX - This code is probably wrong
                 */
                case AF_IPX:
                        {
                        struct ipx_addr *ina = &IA_SIPX(ifa)->sipx_addr;
                        struct arpcom *ac = IFP2AC(ifp);

                        if (ipx_nullhost(*ina))
                                ina->x_host = *(union ipx_host *) ac->ac_enaddr;
                        else
                                bcopy(ina->x_host.c_host, ac->ac_enaddr,
                                      sizeof ac->ac_enaddr);

                        IF_INIT(ifp);   /* Set new address. */
                        break;
                        }
#endif
#ifdef NS
                /*
                 * XXX - This code is probably wrong
                 */
                case AF_NS:
                {
                        struct ns_addr *ina = &(IA_SNS(ifa)->sns_addr);
                        struct arpcom *ac = IFP2AC(ifp);

                        if (ns_nullhost(*ina))
                                ina->x_host = *(union ns_host *)(ac->ac_enaddr);
                        else
                                bcopy(ina->x_host.c_host, ac->ac_enaddr,
                                      sizeof ac->ac_enaddr);

                        /*
                         * Set new address
                         */
                        IF_INIT(ifp);
                        break;
                }
#endif
                default:
                        IF_INIT(ifp);
                        break;
                }
                break;

        case SIOCGIFADDR:
                bcopy(IFP2AC(ifp)->ac_enaddr,
                      ((struct sockaddr *)ifr->ifr_data)->sa_data,
                      ETHER_ADDR_LEN);
                break;

        case SIOCSIFMTU:
                /*
                 * Set the interface MTU.
                 */
                if (ifr->ifr_mtu > ETHERMTU) {
                        error = EINVAL;
                } else {
                        ifp->if_mtu = ifr->ifr_mtu;
                }
                break;
        default:
                error = EINVAL;
                break;
        }
        return (error);

#undef IF_INIT
}

int
ether_resolvemulti(
        struct ifnet *ifp,
        struct sockaddr **llsa,
        struct sockaddr *sa)
{
        struct sockaddr_dl *sdl;
        struct sockaddr_in *sin;
#ifdef INET6
        struct sockaddr_in6 *sin6;
#endif
        u_char *e_addr;

        switch(sa->sa_family) {
        case AF_LINK:
                /*
                 * No mapping needed. Just check that it's a valid MC address.
                 */
                sdl = (struct sockaddr_dl *)sa;
                e_addr = LLADDR(sdl);
                if ((e_addr[0] & 1) != 1)
                        return EADDRNOTAVAIL;
                *llsa = 0;
                return 0;

#ifdef INET
        case AF_INET:
                sin = (struct sockaddr_in *)sa;
                if (!IN_MULTICAST(ntohl(sin->sin_addr.s_addr)))
                        return EADDRNOTAVAIL;
                MALLOC(sdl, struct sockaddr_dl *, sizeof *sdl, M_IFMADDR,
                       M_WAITOK | M_ZERO);
                sdl->sdl_len = sizeof *sdl;
                sdl->sdl_family = AF_LINK;
                sdl->sdl_index = ifp->if_index;
                sdl->sdl_type = IFT_ETHER;
                sdl->sdl_alen = ETHER_ADDR_LEN;
                e_addr = LLADDR(sdl);
                ETHER_MAP_IP_MULTICAST(&sin->sin_addr, e_addr);
                *llsa = (struct sockaddr *)sdl;
                return 0;
#endif
#ifdef INET6
        case AF_INET6:
                sin6 = (struct sockaddr_in6 *)sa;
                if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
                        /*
                         * An IP6 address of 0 means listen to all
                         * of the Ethernet multicast address used for IP6.
                         * (This is used for multicast routers.)
                         */
                        ifp->if_flags |= IFF_ALLMULTI;
                        *llsa = 0;
                        return 0;
                }
                if (!IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
                        return EADDRNOTAVAIL;
                MALLOC(sdl, struct sockaddr_dl *, sizeof *sdl, M_IFMADDR,
                       M_WAITOK | M_ZERO);
                sdl->sdl_len = sizeof *sdl;
                sdl->sdl_family = AF_LINK;
                sdl->sdl_index = ifp->if_index;
                sdl->sdl_type = IFT_ETHER;
                sdl->sdl_alen = ETHER_ADDR_LEN;
                e_addr = LLADDR(sdl);
                ETHER_MAP_IPV6_MULTICAST(&sin6->sin6_addr, e_addr);
                *llsa = (struct sockaddr *)sdl;
                return 0;
#endif

        default:
                /*
                 * Well, the text isn't quite right, but it's the name
                 * that counts...
                 */
                return EAFNOSUPPORT;
        }
}

#if 0
/*
 * This is for reference.  We have a table-driven version
 * of the little-endian crc32 generator, which is faster
 * than the double-loop.
 */
uint32_t
ether_crc32_le(const uint8_t *buf, size_t len)
{
        uint32_t c, crc, carry;
        size_t i, j;

        crc = 0xffffffffU;      /* initial value */

        for (i = 0; i < len; i++) {
                c = buf[i];
                for (j = 0; j < 8; j++) {
                        carry = ((crc & 0x01) ? 1 : 0) ^ (c & 0x01);
                        crc >>= 1;
                        c >>= 1;
                        if (carry)
                                crc = (crc ^ ETHER_CRC_POLY_LE);
                }
        }

        return (crc);
}
#else
uint32_t
ether_crc32_le(const uint8_t *buf, size_t len)
{
        static const uint32_t crctab[] = {
                0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
                0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
                0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
                0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c
        };
        uint32_t crc;
        size_t i;

        crc = 0xffffffffU;      /* initial value */

        for (i = 0; i < len; i++) {
                crc ^= buf[i];
                crc = (crc >> 4) ^ crctab[crc & 0xf];
                crc = (crc >> 4) ^ crctab[crc & 0xf];
        }

        return (crc);
}
#endif

uint32_t
ether_crc32_be(const uint8_t *buf, size_t len)
{
        uint32_t c, crc, carry;
        size_t i, j;

        crc = 0xffffffffU;      /* initial value */

        for (i = 0; i < len; i++) {
                c = buf[i];
                for (j = 0; j < 8; j++) {
                        carry = ((crc & 0x80000000U) ? 1 : 0) ^ (c & 0x01);
                        crc <<= 1;
                        c >>= 1;
                        if (carry)
                                crc = (crc ^ ETHER_CRC_POLY_BE) | carry;
                }
        }

        return (crc);
}

/*
 * find the size of ethernet header, and call classifier
 */
void
altq_etherclassify(struct ifaltq *ifq, struct mbuf *m,
                   struct altq_pktattr *pktattr)
{
        struct ether_header *eh;
        uint16_t ether_type;
        int hlen, af, hdrsize;
        caddr_t hdr;

        hlen = sizeof(struct ether_header);
        eh = mtod(m, struct ether_header *);

        ether_type = ntohs(eh->ether_type);
        if (ether_type < ETHERMTU) {
                /* ick! LLC/SNAP */
                struct llc *llc = (struct llc *)(eh + 1);
                hlen += 8;

                if (m->m_len < hlen ||
                    llc->llc_dsap != LLC_SNAP_LSAP ||
                    llc->llc_ssap != LLC_SNAP_LSAP ||
                    llc->llc_control != LLC_UI)
                        goto bad;  /* not snap! */

                ether_type = ntohs(llc->llc_un.type_snap.ether_type);
        }

        if (ether_type == ETHERTYPE_IP) {
                af = AF_INET;
                hdrsize = 20;  /* sizeof(struct ip) */
#ifdef INET6
        } else if (ether_type == ETHERTYPE_IPV6) {
                af = AF_INET6;
                hdrsize = 40;  /* sizeof(struct ip6_hdr) */
#endif
        } else
                goto bad;

        while (m->m_len <= hlen) {
                hlen -= m->m_len;
                m = m->m_next;
        }
        hdr = m->m_data + hlen;
        if (m->m_len < hlen + hdrsize) {
                /*
                 * ip header is not in a single mbuf.  this should not
                 * happen in the current code.
                 * (todo: use m_pulldown in the future)
                 */
                goto bad;
        }
        m->m_data += hlen;
        m->m_len -= hlen;
        ifq_classify(ifq, m, af, pktattr);
        m->m_data -= hlen;
        m->m_len += hlen;

        return;

bad:
        pktattr->pattr_class = NULL;
        pktattr->pattr_hdr = NULL;
        pktattr->pattr_af = AF_UNSPEC;
}

static void
ether_restore_header(struct mbuf **m0, const struct ether_header *eh,
                     const struct ether_header *save_eh)
{
        struct mbuf *m = *m0;

        ether_restore_hdr++;

        /*
         * Prepend the header, optimize for the common case of
         * eh pointing into the mbuf.
         */
        if ((const void *)(eh + 1) == (void *)m->m_data) {
                m->m_data -= ETHER_HDR_LEN;
                m->m_len += ETHER_HDR_LEN;
                m->m_pkthdr.len += ETHER_HDR_LEN;
        } else {
                ether_prepend_hdr++;

                M_PREPEND(m, ETHER_HDR_LEN, MB_DONTWAIT);
                if (m != NULL) {
                        bcopy(save_eh, mtod(m, struct ether_header *),
                              ETHER_HDR_LEN);
                }
        }
        *m0 = m;
}

#ifdef ETHER_INPUT_CHAIN

static void
ether_input_ipifunc(void *arg)
{
        struct mbuf *m, *next;
        lwkt_port_t port;

        m = arg;
        do {
                next = m->m_nextpkt;
                m->m_nextpkt = NULL;

                port = m->m_pkthdr.header;
                m->m_pkthdr.header = NULL;

                lwkt_sendmsg(port,
                &m->m_hdr.mh_netmsg.nm_netmsg.nm_lmsg);

                m = next;
        } while (m != NULL);
}

void
ether_input_dispatch(struct mbuf_chain *chain)
{
#ifdef SMP
        int i;

        for (i = 0; i < ncpus; ++i) {
                if (chain[i].mc_head != NULL) {
                        lwkt_send_ipiq(globaldata_find(i),
                        ether_input_ipifunc, chain[i].mc_head);
                }
        }
#else
        ether_input_ipifunc(chain->mc_head);
#endif
}

#endif  /* ETHER_INPUT_CHAIN */