The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


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sys/net/if_ethersubr.c

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    1 /*-
    2  * Copyright (c) 1982, 1989, 1993
    3  *      The Regents of the University of California.  All rights reserved.
    4  *
    5  * Redistribution and use in source and binary forms, with or without
    6  * modification, are permitted provided that the following conditions
    7  * are met:
    8  * 1. Redistributions of source code must retain the above copyright
    9  *    notice, this list of conditions and the following disclaimer.
   10  * 2. Redistributions in binary form must reproduce the above copyright
   11  *    notice, this list of conditions and the following disclaimer in the
   12  *    documentation and/or other materials provided with the distribution.
   13  * 4. Neither the name of the University nor the names of its contributors
   14  *    may be used to endorse or promote products derived from this software
   15  *    without specific prior written permission.
   16  *
   17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   27  * SUCH DAMAGE.
   28  *
   29  *      @(#)if_ethersubr.c      8.1 (Berkeley) 6/10/93
   30  * $FreeBSD: releng/8.1/sys/net/if_ethersubr.c 205511 2010-03-23 09:58:59Z luigi $
   31  */
   32 
   33 #include "opt_atalk.h"
   34 #include "opt_inet.h"
   35 #include "opt_inet6.h"
   36 #include "opt_ipx.h"
   37 #include "opt_netgraph.h"
   38 #include "opt_carp.h"
   39 #include "opt_mbuf_profiling.h"
   40 
   41 #include <sys/param.h>
   42 #include <sys/systm.h>
   43 #include <sys/kernel.h>
   44 #include <sys/lock.h>
   45 #include <sys/malloc.h>
   46 #include <sys/module.h>
   47 #include <sys/mbuf.h>
   48 #include <sys/random.h>
   49 #include <sys/rwlock.h>
   50 #include <sys/socket.h>
   51 #include <sys/sockio.h>
   52 #include <sys/sysctl.h>
   53 
   54 #include <net/if.h>
   55 #include <net/if_arp.h>
   56 #include <net/netisr.h>
   57 #include <net/route.h>
   58 #include <net/if_llc.h>
   59 #include <net/if_dl.h>
   60 #include <net/if_types.h>
   61 #include <net/bpf.h>
   62 #include <net/ethernet.h>
   63 #include <net/if_bridgevar.h>
   64 #include <net/if_vlan_var.h>
   65 #include <net/if_llatbl.h>
   66 #include <net/pf_mtag.h>
   67 #include <net/vnet.h>
   68 
   69 #if defined(INET) || defined(INET6)
   70 #include <netinet/in.h>
   71 #include <netinet/in_var.h>
   72 #include <netinet/if_ether.h>
   73 #include <netinet/ip_var.h>
   74 #include <netinet/ip_fw.h>
   75 #include <netinet/ipfw/ip_fw_private.h>
   76 #endif
   77 #ifdef INET6
   78 #include <netinet6/nd6.h>
   79 #endif
   80 
   81 #if defined(INET) || defined(INET6)
   82 #ifdef DEV_CARP
   83 #include <netinet/ip_carp.h>
   84 #endif
   85 #endif
   86 
   87 #ifdef IPX
   88 #include <netipx/ipx.h>
   89 #include <netipx/ipx_if.h>
   90 #endif
   91 
   92 int (*ef_inputp)(struct ifnet*, struct ether_header *eh, struct mbuf *m);
   93 int (*ef_outputp)(struct ifnet *ifp, struct mbuf **mp,
   94                 struct sockaddr *dst, short *tp, int *hlen);
   95 
   96 #ifdef NETATALK
   97 #include <netatalk/at.h>
   98 #include <netatalk/at_var.h>
   99 #include <netatalk/at_extern.h>
  100 
  101 #define llc_snap_org_code llc_un.type_snap.org_code
  102 #define llc_snap_ether_type llc_un.type_snap.ether_type
  103 
  104 extern u_char   at_org_code[3];
  105 extern u_char   aarp_org_code[3];
  106 #endif /* NETATALK */
  107 
  108 #include <security/mac/mac_framework.h>
  109 
  110 #ifdef CTASSERT
  111 CTASSERT(sizeof (struct ether_header) == ETHER_ADDR_LEN * 2 + 2);
  112 CTASSERT(sizeof (struct ether_addr) == ETHER_ADDR_LEN);
  113 #endif
  114 
  115 /* netgraph node hooks for ng_ether(4) */
  116 void    (*ng_ether_input_p)(struct ifnet *ifp, struct mbuf **mp);
  117 void    (*ng_ether_input_orphan_p)(struct ifnet *ifp, struct mbuf *m);
  118 int     (*ng_ether_output_p)(struct ifnet *ifp, struct mbuf **mp);
  119 void    (*ng_ether_attach_p)(struct ifnet *ifp);
  120 void    (*ng_ether_detach_p)(struct ifnet *ifp);
  121 
  122 void    (*vlan_input_p)(struct ifnet *, struct mbuf *);
  123 
  124 /* if_bridge(4) support */
  125 struct mbuf *(*bridge_input_p)(struct ifnet *, struct mbuf *); 
  126 int     (*bridge_output_p)(struct ifnet *, struct mbuf *, 
  127                 struct sockaddr *, struct rtentry *);
  128 void    (*bridge_dn_p)(struct mbuf *, struct ifnet *);
  129 
  130 /* if_lagg(4) support */
  131 struct mbuf *(*lagg_input_p)(struct ifnet *, struct mbuf *); 
  132 
  133 static const u_char etherbroadcastaddr[ETHER_ADDR_LEN] =
  134                         { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
  135 
  136 static  int ether_resolvemulti(struct ifnet *, struct sockaddr **,
  137                 struct sockaddr *);
  138 
  139 /* XXX: should be in an arp support file, not here */
  140 MALLOC_DEFINE(M_ARPCOM, "arpcom", "802.* interface internals");
  141 
  142 #define ETHER_IS_BROADCAST(addr) \
  143         (bcmp(etherbroadcastaddr, (addr), ETHER_ADDR_LEN) == 0)
  144 
  145 #define senderr(e) do { error = (e); goto bad;} while (0)
  146 
  147 #if defined(INET) || defined(INET6)
  148 int
  149 ether_ipfw_chk(struct mbuf **m0, struct ifnet *dst, int shared);
  150 static VNET_DEFINE(int, ether_ipfw);
  151 #define V_ether_ipfw    VNET(ether_ipfw)
  152 #endif
  153 
  154 
  155 /*
  156  * Ethernet output routine.
  157  * Encapsulate a packet of type family for the local net.
  158  * Use trailer local net encapsulation if enough data in first
  159  * packet leaves a multiple of 512 bytes of data in remainder.
  160  */
  161 int
  162 ether_output(struct ifnet *ifp, struct mbuf *m,
  163         struct sockaddr *dst, struct route *ro)
  164 {
  165         short type;
  166         int error = 0, hdrcmplt = 0;
  167         u_char esrc[ETHER_ADDR_LEN], edst[ETHER_ADDR_LEN];
  168         struct llentry *lle = NULL;
  169         struct rtentry *rt0 = NULL;
  170         struct ether_header *eh;
  171         struct pf_mtag *t;
  172         int loop_copy = 1;
  173         int hlen;       /* link layer header length */
  174 
  175         if (ro != NULL) {
  176                 if (!(m->m_flags & (M_BCAST | M_MCAST)))
  177                         lle = ro->ro_lle;
  178                 rt0 = ro->ro_rt;
  179         }
  180 #ifdef MAC
  181         error = mac_ifnet_check_transmit(ifp, m);
  182         if (error)
  183                 senderr(error);
  184 #endif
  185 
  186         M_PROFILE(m);
  187         if (ifp->if_flags & IFF_MONITOR)
  188                 senderr(ENETDOWN);
  189         if (!((ifp->if_flags & IFF_UP) &&
  190             (ifp->if_drv_flags & IFF_DRV_RUNNING)))
  191                 senderr(ENETDOWN);
  192 
  193         hlen = ETHER_HDR_LEN;
  194         switch (dst->sa_family) {
  195 #ifdef INET
  196         case AF_INET:
  197                 if (lle != NULL && (lle->la_flags & LLE_VALID))
  198                         memcpy(edst, &lle->ll_addr.mac16, sizeof(edst));
  199                 else
  200                         error = arpresolve(ifp, rt0, m, dst, edst, &lle);
  201                 if (error)
  202                         return (error == EWOULDBLOCK ? 0 : error);
  203                 type = htons(ETHERTYPE_IP);
  204                 break;
  205         case AF_ARP:
  206         {
  207                 struct arphdr *ah;
  208                 ah = mtod(m, struct arphdr *);
  209                 ah->ar_hrd = htons(ARPHRD_ETHER);
  210 
  211                 loop_copy = 0; /* if this is for us, don't do it */
  212 
  213                 switch(ntohs(ah->ar_op)) {
  214                 case ARPOP_REVREQUEST:
  215                 case ARPOP_REVREPLY:
  216                         type = htons(ETHERTYPE_REVARP);
  217                         break;
  218                 case ARPOP_REQUEST:
  219                 case ARPOP_REPLY:
  220                 default:
  221                         type = htons(ETHERTYPE_ARP);
  222                         break;
  223                 }
  224 
  225                 if (m->m_flags & M_BCAST)
  226                         bcopy(ifp->if_broadcastaddr, edst, ETHER_ADDR_LEN);
  227                 else
  228                         bcopy(ar_tha(ah), edst, ETHER_ADDR_LEN);
  229 
  230         }
  231         break;
  232 #endif
  233 #ifdef INET6
  234         case AF_INET6:
  235                 if (lle != NULL && (lle->la_flags & LLE_VALID))
  236                         memcpy(edst, &lle->ll_addr.mac16, sizeof(edst));
  237                 else
  238                         error = nd6_storelladdr(ifp, m, dst, (u_char *)edst, &lle);
  239                 if (error)
  240                         return error;
  241                 type = htons(ETHERTYPE_IPV6);
  242                 break;
  243 #endif
  244 #ifdef IPX
  245         case AF_IPX:
  246                 if (ef_outputp) {
  247                     error = ef_outputp(ifp, &m, dst, &type, &hlen);
  248                     if (error)
  249                         goto bad;
  250                 } else
  251                     type = htons(ETHERTYPE_IPX);
  252                 bcopy((caddr_t)&(((struct sockaddr_ipx *)dst)->sipx_addr.x_host),
  253                     (caddr_t)edst, sizeof (edst));
  254                 break;
  255 #endif
  256 #ifdef NETATALK
  257         case AF_APPLETALK:
  258           {
  259             struct at_ifaddr *aa;
  260 
  261             if ((aa = at_ifawithnet((struct sockaddr_at *)dst)) == NULL)
  262                     senderr(EHOSTUNREACH); /* XXX */
  263             if (!aarpresolve(ifp, m, (struct sockaddr_at *)dst, edst)) {
  264                     ifa_free(&aa->aa_ifa);
  265                     return (0);
  266             }
  267             /*
  268              * In the phase 2 case, need to prepend an mbuf for the llc header.
  269              */
  270             if ( aa->aa_flags & AFA_PHASE2 ) {
  271                 struct llc llc;
  272 
  273                 ifa_free(&aa->aa_ifa);
  274                 M_PREPEND(m, LLC_SNAPFRAMELEN, M_DONTWAIT);
  275                 if (m == NULL)
  276                         senderr(ENOBUFS);
  277                 llc.llc_dsap = llc.llc_ssap = LLC_SNAP_LSAP;
  278                 llc.llc_control = LLC_UI;
  279                 bcopy(at_org_code, llc.llc_snap_org_code, sizeof(at_org_code));
  280                 llc.llc_snap_ether_type = htons( ETHERTYPE_AT );
  281                 bcopy(&llc, mtod(m, caddr_t), LLC_SNAPFRAMELEN);
  282                 type = htons(m->m_pkthdr.len);
  283                 hlen = LLC_SNAPFRAMELEN + ETHER_HDR_LEN;
  284             } else {
  285                 ifa_free(&aa->aa_ifa);
  286                 type = htons(ETHERTYPE_AT);
  287             }
  288             break;
  289           }
  290 #endif /* NETATALK */
  291 
  292         case pseudo_AF_HDRCMPLT:
  293                 hdrcmplt = 1;
  294                 eh = (struct ether_header *)dst->sa_data;
  295                 (void)memcpy(esrc, eh->ether_shost, sizeof (esrc));
  296                 /* FALLTHROUGH */
  297 
  298         case AF_UNSPEC:
  299                 loop_copy = 0; /* if this is for us, don't do it */
  300                 eh = (struct ether_header *)dst->sa_data;
  301                 (void)memcpy(edst, eh->ether_dhost, sizeof (edst));
  302                 type = eh->ether_type;
  303                 break;
  304 
  305         default:
  306                 if_printf(ifp, "can't handle af%d\n", dst->sa_family);
  307                 senderr(EAFNOSUPPORT);
  308         }
  309 
  310         if (lle != NULL && (lle->la_flags & LLE_IFADDR)) {
  311                 int csum_flags = 0;
  312                 if (m->m_pkthdr.csum_flags & CSUM_IP)
  313                         csum_flags |= (CSUM_IP_CHECKED|CSUM_IP_VALID);
  314                 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA)
  315                         csum_flags |= (CSUM_DATA_VALID|CSUM_PSEUDO_HDR);
  316                 if (m->m_pkthdr.csum_flags & CSUM_SCTP)
  317                         csum_flags |= CSUM_SCTP_VALID;
  318                 m->m_pkthdr.csum_flags |= csum_flags;
  319                 m->m_pkthdr.csum_data = 0xffff;
  320                 return (if_simloop(ifp, m, dst->sa_family, 0));
  321         }
  322 
  323         /*
  324          * Add local net header.  If no space in first mbuf,
  325          * allocate another.
  326          */
  327         M_PREPEND(m, ETHER_HDR_LEN, M_DONTWAIT);
  328         if (m == NULL)
  329                 senderr(ENOBUFS);
  330         eh = mtod(m, struct ether_header *);
  331         (void)memcpy(&eh->ether_type, &type,
  332                 sizeof(eh->ether_type));
  333         (void)memcpy(eh->ether_dhost, edst, sizeof (edst));
  334         if (hdrcmplt)
  335                 (void)memcpy(eh->ether_shost, esrc,
  336                         sizeof(eh->ether_shost));
  337         else
  338                 (void)memcpy(eh->ether_shost, IF_LLADDR(ifp),
  339                         sizeof(eh->ether_shost));
  340 
  341         /*
  342          * If a simplex interface, and the packet is being sent to our
  343          * Ethernet address or a broadcast address, loopback a copy.
  344          * XXX To make a simplex device behave exactly like a duplex
  345          * device, we should copy in the case of sending to our own
  346          * ethernet address (thus letting the original actually appear
  347          * on the wire). However, we don't do that here for security
  348          * reasons and compatibility with the original behavior.
  349          */
  350         if ((ifp->if_flags & IFF_SIMPLEX) && loop_copy &&
  351             ((t = pf_find_mtag(m)) == NULL || !t->routed)) {
  352                 int csum_flags = 0;
  353 
  354                 if (m->m_pkthdr.csum_flags & CSUM_IP)
  355                         csum_flags |= (CSUM_IP_CHECKED|CSUM_IP_VALID);
  356                 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA)
  357                         csum_flags |= (CSUM_DATA_VALID|CSUM_PSEUDO_HDR);
  358                 if (m->m_pkthdr.csum_flags & CSUM_SCTP)
  359                         csum_flags |= CSUM_SCTP_VALID;
  360 
  361                 if (m->m_flags & M_BCAST) {
  362                         struct mbuf *n;
  363 
  364                         /*
  365                          * Because if_simloop() modifies the packet, we need a
  366                          * writable copy through m_dup() instead of a readonly
  367                          * one as m_copy[m] would give us. The alternative would
  368                          * be to modify if_simloop() to handle the readonly mbuf,
  369                          * but performancewise it is mostly equivalent (trading
  370                          * extra data copying vs. extra locking).
  371                          *
  372                          * XXX This is a local workaround.  A number of less
  373                          * often used kernel parts suffer from the same bug.
  374                          * See PR kern/105943 for a proposed general solution.
  375                          */
  376                         if ((n = m_dup(m, M_DONTWAIT)) != NULL) {
  377                                 n->m_pkthdr.csum_flags |= csum_flags;
  378                                 if (csum_flags & CSUM_DATA_VALID)
  379                                         n->m_pkthdr.csum_data = 0xffff;
  380                                 (void)if_simloop(ifp, n, dst->sa_family, hlen);
  381                         } else
  382                                 ifp->if_iqdrops++;
  383                 } else if (bcmp(eh->ether_dhost, eh->ether_shost,
  384                                 ETHER_ADDR_LEN) == 0) {
  385                         m->m_pkthdr.csum_flags |= csum_flags;
  386                         if (csum_flags & CSUM_DATA_VALID)
  387                                 m->m_pkthdr.csum_data = 0xffff;
  388                         (void) if_simloop(ifp, m, dst->sa_family, hlen);
  389                         return (0);     /* XXX */
  390                 }
  391         }
  392 
  393        /*
  394         * Bridges require special output handling.
  395         */
  396         if (ifp->if_bridge) {
  397                 BRIDGE_OUTPUT(ifp, m, error);
  398                 return (error);
  399         }
  400 
  401 #if defined(INET) || defined(INET6)
  402 #ifdef DEV_CARP
  403         if (ifp->if_carp &&
  404             (error = carp_output(ifp, m, dst, NULL)))
  405                 goto bad;
  406 #endif
  407 #endif
  408 
  409         /* Handle ng_ether(4) processing, if any */
  410         if (IFP2AC(ifp)->ac_netgraph != NULL) {
  411                 KASSERT(ng_ether_output_p != NULL,
  412                     ("ng_ether_output_p is NULL"));
  413                 if ((error = (*ng_ether_output_p)(ifp, &m)) != 0) {
  414 bad:                    if (m != NULL)
  415                                 m_freem(m);
  416                         return (error);
  417                 }
  418                 if (m == NULL)
  419                         return (0);
  420         }
  421 
  422         /* Continue with link-layer output */
  423         return ether_output_frame(ifp, m);
  424 }
  425 
  426 /*
  427  * Ethernet link layer output routine to send a raw frame to the device.
  428  *
  429  * This assumes that the 14 byte Ethernet header is present and contiguous
  430  * in the first mbuf (if BRIDGE'ing).
  431  */
  432 int
  433 ether_output_frame(struct ifnet *ifp, struct mbuf *m)
  434 {
  435 #if defined(INET) || defined(INET6)
  436 
  437         if (V_ip_fw_chk_ptr && V_ether_ipfw != 0) {
  438                 if (ether_ipfw_chk(&m, ifp, 0) == 0) {
  439                         if (m) {
  440                                 m_freem(m);
  441                                 return EACCES;  /* pkt dropped */
  442                         } else
  443                                 return 0;       /* consumed e.g. in a pipe */
  444                 }
  445         }
  446 #endif
  447 
  448         /*
  449          * Queue message on interface, update output statistics if
  450          * successful, and start output if interface not yet active.
  451          */
  452         return ((ifp->if_transmit)(ifp, m));
  453 }
  454 
  455 #if defined(INET) || defined(INET6)
  456 /*
  457  * ipfw processing for ethernet packets (in and out).
  458  * The second parameter is NULL from ether_demux, and ifp from
  459  * ether_output_frame.
  460  */
  461 int
  462 ether_ipfw_chk(struct mbuf **m0, struct ifnet *dst, int shared)
  463 {
  464         struct ether_header *eh;
  465         struct ether_header save_eh;
  466         struct mbuf *m;
  467         int i;
  468         struct ip_fw_args args;
  469         struct m_tag *mtag;
  470 
  471         /* fetch start point from rule, if any */
  472         mtag = m_tag_locate(*m0, MTAG_IPFW_RULE, 0, NULL);
  473         if (mtag == NULL) {
  474                 args.rule.slot = 0;
  475         } else {
  476                         /* dummynet packet, already partially processed */
  477                 struct ipfw_rule_ref *r;
  478 
  479                 /* XXX can we free it after use ? */
  480                 mtag->m_tag_id = PACKET_TAG_NONE;
  481                 r = (struct ipfw_rule_ref *)(mtag + 1);
  482                 if (r->info & IPFW_ONEPASS)
  483                         return (1);
  484                 args.rule = *r;
  485         }
  486 
  487         /*
  488          * I need some amt of data to be contiguous, and in case others need
  489          * the packet (shared==1) also better be in the first mbuf.
  490          */
  491         m = *m0;
  492         i = min( m->m_pkthdr.len, max_protohdr);
  493         if ( shared || m->m_len < i) {
  494                 m = m_pullup(m, i);
  495                 if (m == NULL) {
  496                         *m0 = m;
  497                         return 0;
  498                 }
  499         }
  500         eh = mtod(m, struct ether_header *);
  501         save_eh = *eh;                  /* save copy for restore below */
  502         m_adj(m, ETHER_HDR_LEN);        /* strip ethernet header */
  503 
  504         args.m = m;             /* the packet we are looking at         */
  505         args.oif = dst;         /* destination, if any                  */
  506         args.next_hop = NULL;   /* we do not support forward yet        */
  507         args.eh = &save_eh;     /* MAC header for bridged/MAC packets   */
  508         args.inp = NULL;        /* used by ipfw uid/gid/jail rules      */
  509         i = V_ip_fw_chk_ptr(&args);
  510         m = args.m;
  511         if (m != NULL) {
  512                 /*
  513                  * Restore Ethernet header, as needed, in case the
  514                  * mbuf chain was replaced by ipfw.
  515                  */
  516                 M_PREPEND(m, ETHER_HDR_LEN, M_DONTWAIT);
  517                 if (m == NULL) {
  518                         *m0 = m;
  519                         return 0;
  520                 }
  521                 if (eh != mtod(m, struct ether_header *))
  522                         bcopy(&save_eh, mtod(m, struct ether_header *),
  523                                 ETHER_HDR_LEN);
  524         }
  525         *m0 = m;
  526 
  527         if (i == IP_FW_DENY) /* drop */
  528                 return 0;
  529 
  530         KASSERT(m != NULL, ("ether_ipfw_chk: m is NULL"));
  531 
  532         if (i == IP_FW_PASS) /* a PASS rule.  */
  533                 return 1;
  534 
  535         if (ip_dn_io_ptr && (i == IP_FW_DUMMYNET)) {
  536                 int dir;
  537                 /*
  538                  * Pass the pkt to dummynet, which consumes it.
  539                  * If shared, make a copy and keep the original.
  540                  */
  541                 if (shared) {
  542                         m = m_copypacket(m, M_DONTWAIT);
  543                         if (m == NULL)
  544                                 return 0;
  545                 } else {
  546                         /*
  547                          * Pass the original to dummynet and
  548                          * nothing back to the caller
  549                          */
  550                         *m0 = NULL ;
  551                 }
  552                 dir = PROTO_LAYER2 | (dst ? DIR_OUT : DIR_IN);
  553                 ip_dn_io_ptr(&m, dir, &args);
  554                 return 0;
  555         }
  556         /*
  557          * XXX at some point add support for divert/forward actions.
  558          * If none of the above matches, we have to drop the pkt.
  559          */
  560         return 0;
  561 }
  562 #endif
  563 
  564 /*
  565  * Process a received Ethernet packet; the packet is in the
  566  * mbuf chain m with the ethernet header at the front.
  567  */
  568 static void
  569 ether_input(struct ifnet *ifp, struct mbuf *m)
  570 {
  571         struct ether_header *eh;
  572         u_short etype;
  573 
  574         if ((ifp->if_flags & IFF_UP) == 0) {
  575                 m_freem(m);
  576                 return;
  577         }
  578 #ifdef DIAGNOSTIC
  579         if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
  580                 if_printf(ifp, "discard frame at !IFF_DRV_RUNNING\n");
  581                 m_freem(m);
  582                 return;
  583         }
  584 #endif
  585         /*
  586          * Do consistency checks to verify assumptions
  587          * made by code past this point.
  588          */
  589         if ((m->m_flags & M_PKTHDR) == 0) {
  590                 if_printf(ifp, "discard frame w/o packet header\n");
  591                 ifp->if_ierrors++;
  592                 m_freem(m);
  593                 return;
  594         }
  595         if (m->m_len < ETHER_HDR_LEN) {
  596                 /* XXX maybe should pullup? */
  597                 if_printf(ifp, "discard frame w/o leading ethernet "
  598                                 "header (len %u pkt len %u)\n",
  599                                 m->m_len, m->m_pkthdr.len);
  600                 ifp->if_ierrors++;
  601                 m_freem(m);
  602                 return;
  603         }
  604         eh = mtod(m, struct ether_header *);
  605         etype = ntohs(eh->ether_type);
  606         if (m->m_pkthdr.rcvif == NULL) {
  607                 if_printf(ifp, "discard frame w/o interface pointer\n");
  608                 ifp->if_ierrors++;
  609                 m_freem(m);
  610                 return;
  611         }
  612 #ifdef DIAGNOSTIC
  613         if (m->m_pkthdr.rcvif != ifp) {
  614                 if_printf(ifp, "Warning, frame marked as received on %s\n",
  615                         m->m_pkthdr.rcvif->if_xname);
  616         }
  617 #endif
  618 
  619         CURVNET_SET_QUIET(ifp->if_vnet);
  620 
  621         if (ETHER_IS_MULTICAST(eh->ether_dhost)) {
  622                 if (ETHER_IS_BROADCAST(eh->ether_dhost))
  623                         m->m_flags |= M_BCAST;
  624                 else
  625                         m->m_flags |= M_MCAST;
  626                 ifp->if_imcasts++;
  627         }
  628 
  629 #ifdef MAC
  630         /*
  631          * Tag the mbuf with an appropriate MAC label before any other
  632          * consumers can get to it.
  633          */
  634         mac_ifnet_create_mbuf(ifp, m);
  635 #endif
  636 
  637         /*
  638          * Give bpf a chance at the packet.
  639          */
  640         ETHER_BPF_MTAP(ifp, m);
  641 
  642         /*
  643          * If the CRC is still on the packet, trim it off. We do this once
  644          * and once only in case we are re-entered. Nothing else on the
  645          * Ethernet receive path expects to see the FCS.
  646          */
  647         if (m->m_flags & M_HASFCS) {
  648                 m_adj(m, -ETHER_CRC_LEN);
  649                 m->m_flags &= ~M_HASFCS;
  650         }
  651 
  652         ifp->if_ibytes += m->m_pkthdr.len;
  653 
  654         /* Allow monitor mode to claim this frame, after stats are updated. */
  655         if (ifp->if_flags & IFF_MONITOR) {
  656                 m_freem(m);
  657                 CURVNET_RESTORE();
  658                 return;
  659         }
  660 
  661         /* Handle input from a lagg(4) port */
  662         if (ifp->if_type == IFT_IEEE8023ADLAG) {
  663                 KASSERT(lagg_input_p != NULL,
  664                     ("%s: if_lagg not loaded!", __func__));
  665                 m = (*lagg_input_p)(ifp, m);
  666                 if (m != NULL)
  667                         ifp = m->m_pkthdr.rcvif;
  668                 else 
  669                         return;
  670         }
  671 
  672         /*
  673          * If the hardware did not process an 802.1Q tag, do this now,
  674          * to allow 802.1P priority frames to be passed to the main input
  675          * path correctly.
  676          * TODO: Deal with Q-in-Q frames, but not arbitrary nesting levels.
  677          */
  678         if ((m->m_flags & M_VLANTAG) == 0 && etype == ETHERTYPE_VLAN) {
  679                 struct ether_vlan_header *evl;
  680 
  681                 if (m->m_len < sizeof(*evl) &&
  682                     (m = m_pullup(m, sizeof(*evl))) == NULL) {
  683 #ifdef DIAGNOSTIC
  684                         if_printf(ifp, "cannot pullup VLAN header\n");
  685 #endif
  686                         ifp->if_ierrors++;
  687                         m_freem(m);
  688                         return;
  689                 }
  690 
  691                 evl = mtod(m, struct ether_vlan_header *);
  692                 m->m_pkthdr.ether_vtag = ntohs(evl->evl_tag);
  693                 m->m_flags |= M_VLANTAG;
  694 
  695                 bcopy((char *)evl, (char *)evl + ETHER_VLAN_ENCAP_LEN,
  696                     ETHER_HDR_LEN - ETHER_TYPE_LEN);
  697                 m_adj(m, ETHER_VLAN_ENCAP_LEN);
  698         }
  699 
  700         /* Allow ng_ether(4) to claim this frame. */
  701         if (IFP2AC(ifp)->ac_netgraph != NULL) {
  702                 KASSERT(ng_ether_input_p != NULL,
  703                     ("%s: ng_ether_input_p is NULL", __func__));
  704                 m->m_flags &= ~M_PROMISC;
  705                 (*ng_ether_input_p)(ifp, &m);
  706                 if (m == NULL) {
  707                         CURVNET_RESTORE();
  708                         return;
  709                 }
  710         }
  711 
  712         /*
  713          * Allow if_bridge(4) to claim this frame.
  714          * The BRIDGE_INPUT() macro will update ifp if the bridge changed it
  715          * and the frame should be delivered locally.
  716          */
  717         if (ifp->if_bridge != NULL) {
  718                 m->m_flags &= ~M_PROMISC;
  719                 BRIDGE_INPUT(ifp, m);
  720                 if (m == NULL) {
  721                         CURVNET_RESTORE();
  722                         return;
  723                 }
  724         }
  725 
  726 #if defined(INET) || defined(INET6)
  727 #ifdef DEV_CARP
  728         /*
  729          * Clear M_PROMISC on frame so that carp(4) will see it when the
  730          * mbuf flows up to Layer 3.
  731          * FreeBSD's implementation of carp(4) uses the inprotosw
  732          * to dispatch IPPROTO_CARP. carp(4) also allocates its own
  733          * Ethernet addresses of the form 00:00:5e:00:01:xx, which
  734          * is outside the scope of the M_PROMISC test below.
  735          * TODO: Maintain a hash table of ethernet addresses other than
  736          * ether_dhost which may be active on this ifp.
  737          */
  738         if (ifp->if_carp && carp_forus(ifp->if_carp, eh->ether_dhost)) {
  739                 m->m_flags &= ~M_PROMISC;
  740         } else
  741 #endif
  742 #endif
  743         {
  744                 /*
  745                  * If the frame received was not for our MAC address, set the
  746                  * M_PROMISC flag on the mbuf chain. The frame may need to
  747                  * be seen by the rest of the Ethernet input path in case of
  748                  * re-entry (e.g. bridge, vlan, netgraph) but should not be
  749                  * seen by upper protocol layers.
  750                  */
  751                 if (!ETHER_IS_MULTICAST(eh->ether_dhost) &&
  752                     bcmp(IF_LLADDR(ifp), eh->ether_dhost, ETHER_ADDR_LEN) != 0)
  753                         m->m_flags |= M_PROMISC;
  754         }
  755 
  756         /* First chunk of an mbuf contains good entropy */
  757         if (harvest.ethernet)
  758                 random_harvest(m, 16, 3, 0, RANDOM_NET);
  759 
  760         ether_demux(ifp, m);
  761         CURVNET_RESTORE();
  762 }
  763 
  764 /*
  765  * Upper layer processing for a received Ethernet packet.
  766  */
  767 void
  768 ether_demux(struct ifnet *ifp, struct mbuf *m)
  769 {
  770         struct ether_header *eh;
  771         int isr;
  772         u_short ether_type;
  773 #if defined(NETATALK)
  774         struct llc *l;
  775 #endif
  776 
  777         KASSERT(ifp != NULL, ("%s: NULL interface pointer", __func__));
  778 
  779 #if defined(INET) || defined(INET6)
  780         /*
  781          * Allow dummynet and/or ipfw to claim the frame.
  782          * Do not do this for PROMISC frames in case we are re-entered.
  783          */
  784         if (V_ip_fw_chk_ptr && V_ether_ipfw != 0 && !(m->m_flags & M_PROMISC)) {
  785                 if (ether_ipfw_chk(&m, NULL, 0) == 0) {
  786                         if (m)
  787                                 m_freem(m);     /* dropped; free mbuf chain */
  788                         return;                 /* consumed */
  789                 }
  790         }
  791 #endif
  792         eh = mtod(m, struct ether_header *);
  793         ether_type = ntohs(eh->ether_type);
  794 
  795         /*
  796          * If this frame has a VLAN tag other than 0, call vlan_input()
  797          * if its module is loaded. Otherwise, drop.
  798          */
  799         if ((m->m_flags & M_VLANTAG) &&
  800             EVL_VLANOFTAG(m->m_pkthdr.ether_vtag) != 0) {
  801                 if (ifp->if_vlantrunk == NULL) {
  802                         ifp->if_noproto++;
  803                         m_freem(m);
  804                         return;
  805                 }
  806                 KASSERT(vlan_input_p != NULL,("%s: VLAN not loaded!",
  807                     __func__));
  808                 /* Clear before possibly re-entering ether_input(). */
  809                 m->m_flags &= ~M_PROMISC;
  810                 (*vlan_input_p)(ifp, m);
  811                 return;
  812         }
  813 
  814         /*
  815          * Pass promiscuously received frames to the upper layer if the user
  816          * requested this by setting IFF_PPROMISC. Otherwise, drop them.
  817          */
  818         if ((ifp->if_flags & IFF_PPROMISC) == 0 && (m->m_flags & M_PROMISC)) {
  819                 m_freem(m);
  820                 return;
  821         }
  822 
  823         /*
  824          * Reset layer specific mbuf flags to avoid confusing upper layers.
  825          * Strip off Ethernet header.
  826          */
  827         m->m_flags &= ~M_VLANTAG;
  828         m->m_flags &= ~(M_PROTOFLAGS);
  829         m_adj(m, ETHER_HDR_LEN);
  830 
  831         /*
  832          * Dispatch frame to upper layer.
  833          */
  834         switch (ether_type) {
  835 #ifdef INET
  836         case ETHERTYPE_IP:
  837                 if ((m = ip_fastforward(m)) == NULL)
  838                         return;
  839                 isr = NETISR_IP;
  840                 break;
  841 
  842         case ETHERTYPE_ARP:
  843                 if (ifp->if_flags & IFF_NOARP) {
  844                         /* Discard packet if ARP is disabled on interface */
  845                         m_freem(m);
  846                         return;
  847                 }
  848                 isr = NETISR_ARP;
  849                 break;
  850 #endif
  851 #ifdef IPX
  852         case ETHERTYPE_IPX:
  853                 if (ef_inputp && ef_inputp(ifp, eh, m) == 0)
  854                         return;
  855                 isr = NETISR_IPX;
  856                 break;
  857 #endif
  858 #ifdef INET6
  859         case ETHERTYPE_IPV6:
  860                 isr = NETISR_IPV6;
  861                 break;
  862 #endif
  863 #ifdef NETATALK
  864         case ETHERTYPE_AT:
  865                 isr = NETISR_ATALK1;
  866                 break;
  867         case ETHERTYPE_AARP:
  868                 isr = NETISR_AARP;
  869                 break;
  870 #endif /* NETATALK */
  871         default:
  872 #ifdef IPX
  873                 if (ef_inputp && ef_inputp(ifp, eh, m) == 0)
  874                         return;
  875 #endif /* IPX */
  876 #if defined(NETATALK)
  877                 if (ether_type > ETHERMTU)
  878                         goto discard;
  879                 l = mtod(m, struct llc *);
  880                 if (l->llc_dsap == LLC_SNAP_LSAP &&
  881                     l->llc_ssap == LLC_SNAP_LSAP &&
  882                     l->llc_control == LLC_UI) {
  883                         if (bcmp(&(l->llc_snap_org_code)[0], at_org_code,
  884                             sizeof(at_org_code)) == 0 &&
  885                             ntohs(l->llc_snap_ether_type) == ETHERTYPE_AT) {
  886                                 m_adj(m, LLC_SNAPFRAMELEN);
  887                                 isr = NETISR_ATALK2;
  888                                 break;
  889                         }
  890                         if (bcmp(&(l->llc_snap_org_code)[0], aarp_org_code,
  891                             sizeof(aarp_org_code)) == 0 &&
  892                             ntohs(l->llc_snap_ether_type) == ETHERTYPE_AARP) {
  893                                 m_adj(m, LLC_SNAPFRAMELEN);
  894                                 isr = NETISR_AARP;
  895                                 break;
  896                         }
  897                 }
  898 #endif /* NETATALK */
  899                 goto discard;
  900         }
  901         netisr_dispatch(isr, m);
  902         return;
  903 
  904 discard:
  905         /*
  906          * Packet is to be discarded.  If netgraph is present,
  907          * hand the packet to it for last chance processing;
  908          * otherwise dispose of it.
  909          */
  910         if (IFP2AC(ifp)->ac_netgraph != NULL) {
  911                 KASSERT(ng_ether_input_orphan_p != NULL,
  912                     ("ng_ether_input_orphan_p is NULL"));
  913                 /*
  914                  * Put back the ethernet header so netgraph has a
  915                  * consistent view of inbound packets.
  916                  */
  917                 M_PREPEND(m, ETHER_HDR_LEN, M_DONTWAIT);
  918                 (*ng_ether_input_orphan_p)(ifp, m);
  919                 return;
  920         }
  921         m_freem(m);
  922 }
  923 
  924 /*
  925  * Convert Ethernet address to printable (loggable) representation.
  926  * This routine is for compatibility; it's better to just use
  927  *
  928  *      printf("%6D", <pointer to address>, ":");
  929  *
  930  * since there's no static buffer involved.
  931  */
  932 char *
  933 ether_sprintf(const u_char *ap)
  934 {
  935         static char etherbuf[18];
  936         snprintf(etherbuf, sizeof (etherbuf), "%6D", ap, ":");
  937         return (etherbuf);
  938 }
  939 
  940 /*
  941  * Perform common duties while attaching to interface list
  942  */
  943 void
  944 ether_ifattach(struct ifnet *ifp, const u_int8_t *lla)
  945 {
  946         int i;
  947         struct ifaddr *ifa;
  948         struct sockaddr_dl *sdl;
  949 
  950         ifp->if_addrlen = ETHER_ADDR_LEN;
  951         ifp->if_hdrlen = ETHER_HDR_LEN;
  952         if_attach(ifp);
  953         ifp->if_mtu = ETHERMTU;
  954         ifp->if_output = ether_output;
  955         ifp->if_input = ether_input;
  956         ifp->if_resolvemulti = ether_resolvemulti;
  957         if (ifp->if_baudrate == 0)
  958                 ifp->if_baudrate = IF_Mbps(10);         /* just a default */
  959         ifp->if_broadcastaddr = etherbroadcastaddr;
  960 
  961         ifa = ifp->if_addr;
  962         KASSERT(ifa != NULL, ("%s: no lladdr!\n", __func__));
  963         sdl = (struct sockaddr_dl *)ifa->ifa_addr;
  964         sdl->sdl_type = IFT_ETHER;
  965         sdl->sdl_alen = ifp->if_addrlen;
  966         bcopy(lla, LLADDR(sdl), ifp->if_addrlen);
  967 
  968         bpfattach(ifp, DLT_EN10MB, ETHER_HDR_LEN);
  969         if (ng_ether_attach_p != NULL)
  970                 (*ng_ether_attach_p)(ifp);
  971 
  972         /* Announce Ethernet MAC address if non-zero. */
  973         for (i = 0; i < ifp->if_addrlen; i++)
  974                 if (lla[i] != 0)
  975                         break; 
  976         if (i != ifp->if_addrlen)
  977                 if_printf(ifp, "Ethernet address: %6D\n", lla, ":");
  978 }
  979 
  980 /*
  981  * Perform common duties while detaching an Ethernet interface
  982  */
  983 void
  984 ether_ifdetach(struct ifnet *ifp)
  985 {
  986         if (IFP2AC(ifp)->ac_netgraph != NULL) {
  987                 KASSERT(ng_ether_detach_p != NULL,
  988                     ("ng_ether_detach_p is NULL"));
  989                 (*ng_ether_detach_p)(ifp);
  990         }
  991 
  992         bpfdetach(ifp);
  993         if_detach(ifp);
  994 }
  995 
  996 SYSCTL_DECL(_net_link);
  997 SYSCTL_NODE(_net_link, IFT_ETHER, ether, CTLFLAG_RW, 0, "Ethernet");
  998 #if defined(INET) || defined(INET6)
  999 SYSCTL_VNET_INT(_net_link_ether, OID_AUTO, ipfw, CTLFLAG_RW,
 1000              &VNET_NAME(ether_ipfw), 0, "Pass ether pkts through firewall");
 1001 #endif
 1002 
 1003 #if 0
 1004 /*
 1005  * This is for reference.  We have a table-driven version
 1006  * of the little-endian crc32 generator, which is faster
 1007  * than the double-loop.
 1008  */
 1009 uint32_t
 1010 ether_crc32_le(const uint8_t *buf, size_t len)
 1011 {
 1012         size_t i;
 1013         uint32_t crc;
 1014         int bit;
 1015         uint8_t data;
 1016 
 1017         crc = 0xffffffff;       /* initial value */
 1018 
 1019         for (i = 0; i < len; i++) {
 1020                 for (data = *buf++, bit = 0; bit < 8; bit++, data >>= 1) {
 1021                         carry = (crc ^ data) & 1;
 1022                         crc >>= 1;
 1023                         if (carry)
 1024                                 crc = (crc ^ ETHER_CRC_POLY_LE);
 1025                 }
 1026         }
 1027 
 1028         return (crc);
 1029 }
 1030 #else
 1031 uint32_t
 1032 ether_crc32_le(const uint8_t *buf, size_t len)
 1033 {
 1034         static const uint32_t crctab[] = {
 1035                 0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
 1036                 0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
 1037                 0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
 1038                 0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c
 1039         };
 1040         size_t i;
 1041         uint32_t crc;
 1042 
 1043         crc = 0xffffffff;       /* initial value */
 1044 
 1045         for (i = 0; i < len; i++) {
 1046                 crc ^= buf[i];
 1047                 crc = (crc >> 4) ^ crctab[crc & 0xf];
 1048                 crc = (crc >> 4) ^ crctab[crc & 0xf];
 1049         }
 1050 
 1051         return (crc);
 1052 }
 1053 #endif
 1054 
 1055 uint32_t
 1056 ether_crc32_be(const uint8_t *buf, size_t len)
 1057 {
 1058         size_t i;
 1059         uint32_t crc, carry;
 1060         int bit;
 1061         uint8_t data;
 1062 
 1063         crc = 0xffffffff;       /* initial value */
 1064 
 1065         for (i = 0; i < len; i++) {
 1066                 for (data = *buf++, bit = 0; bit < 8; bit++, data >>= 1) {
 1067                         carry = ((crc & 0x80000000) ? 1 : 0) ^ (data & 0x01);
 1068                         crc <<= 1;
 1069                         if (carry)
 1070                                 crc = (crc ^ ETHER_CRC_POLY_BE) | carry;
 1071                 }
 1072         }
 1073 
 1074         return (crc);
 1075 }
 1076 
 1077 int
 1078 ether_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
 1079 {
 1080         struct ifaddr *ifa = (struct ifaddr *) data;
 1081         struct ifreq *ifr = (struct ifreq *) data;
 1082         int error = 0;
 1083 
 1084         switch (command) {
 1085         case SIOCSIFADDR:
 1086                 ifp->if_flags |= IFF_UP;
 1087 
 1088                 switch (ifa->ifa_addr->sa_family) {
 1089 #ifdef INET
 1090                 case AF_INET:
 1091                         ifp->if_init(ifp->if_softc);    /* before arpwhohas */
 1092                         arp_ifinit(ifp, ifa);
 1093                         break;
 1094 #endif
 1095 #ifdef IPX
 1096                 /*
 1097                  * XXX - This code is probably wrong
 1098                  */
 1099                 case AF_IPX:
 1100                         {
 1101                         struct ipx_addr *ina = &(IA_SIPX(ifa)->sipx_addr);
 1102 
 1103                         if (ipx_nullhost(*ina))
 1104                                 ina->x_host =
 1105                                     *(union ipx_host *)
 1106                                     IF_LLADDR(ifp);
 1107                         else {
 1108                                 bcopy((caddr_t) ina->x_host.c_host,
 1109                                       (caddr_t) IF_LLADDR(ifp),
 1110                                       ETHER_ADDR_LEN);
 1111                         }
 1112 
 1113                         /*
 1114                          * Set new address
 1115                          */
 1116                         ifp->if_init(ifp->if_softc);
 1117                         break;
 1118                         }
 1119 #endif
 1120                 default:
 1121                         ifp->if_init(ifp->if_softc);
 1122                         break;
 1123                 }
 1124                 break;
 1125 
 1126         case SIOCGIFADDR:
 1127                 {
 1128                         struct sockaddr *sa;
 1129 
 1130                         sa = (struct sockaddr *) & ifr->ifr_data;
 1131                         bcopy(IF_LLADDR(ifp),
 1132                               (caddr_t) sa->sa_data, ETHER_ADDR_LEN);
 1133                 }
 1134                 break;
 1135 
 1136         case SIOCSIFMTU:
 1137                 /*
 1138                  * Set the interface MTU.
 1139                  */
 1140                 if (ifr->ifr_mtu > ETHERMTU) {
 1141                         error = EINVAL;
 1142                 } else {
 1143                         ifp->if_mtu = ifr->ifr_mtu;
 1144                 }
 1145                 break;
 1146         default:
 1147                 error = EINVAL;                 /* XXX netbsd has ENOTTY??? */
 1148                 break;
 1149         }
 1150         return (error);
 1151 }
 1152 
 1153 static int
 1154 ether_resolvemulti(struct ifnet *ifp, struct sockaddr **llsa,
 1155         struct sockaddr *sa)
 1156 {
 1157         struct sockaddr_dl *sdl;
 1158 #ifdef INET
 1159         struct sockaddr_in *sin;
 1160 #endif
 1161 #ifdef INET6
 1162         struct sockaddr_in6 *sin6;
 1163 #endif
 1164         u_char *e_addr;
 1165 
 1166         switch(sa->sa_family) {
 1167         case AF_LINK:
 1168                 /*
 1169                  * No mapping needed. Just check that it's a valid MC address.
 1170                  */
 1171                 sdl = (struct sockaddr_dl *)sa;
 1172                 e_addr = LLADDR(sdl);
 1173                 if (!ETHER_IS_MULTICAST(e_addr))
 1174                         return EADDRNOTAVAIL;
 1175                 *llsa = 0;
 1176                 return 0;
 1177 
 1178 #ifdef INET
 1179         case AF_INET:
 1180                 sin = (struct sockaddr_in *)sa;
 1181                 if (!IN_MULTICAST(ntohl(sin->sin_addr.s_addr)))
 1182                         return EADDRNOTAVAIL;
 1183                 sdl = malloc(sizeof *sdl, M_IFMADDR,
 1184                        M_NOWAIT|M_ZERO);
 1185                 if (sdl == NULL)
 1186                         return ENOMEM;
 1187                 sdl->sdl_len = sizeof *sdl;
 1188                 sdl->sdl_family = AF_LINK;
 1189                 sdl->sdl_index = ifp->if_index;
 1190                 sdl->sdl_type = IFT_ETHER;
 1191                 sdl->sdl_alen = ETHER_ADDR_LEN;
 1192                 e_addr = LLADDR(sdl);
 1193                 ETHER_MAP_IP_MULTICAST(&sin->sin_addr, e_addr);
 1194                 *llsa = (struct sockaddr *)sdl;
 1195                 return 0;
 1196 #endif
 1197 #ifdef INET6
 1198         case AF_INET6:
 1199                 sin6 = (struct sockaddr_in6 *)sa;
 1200                 if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
 1201                         /*
 1202                          * An IP6 address of 0 means listen to all
 1203                          * of the Ethernet multicast address used for IP6.
 1204                          * (This is used for multicast routers.)
 1205                          */
 1206                         ifp->if_flags |= IFF_ALLMULTI;
 1207                         *llsa = 0;
 1208                         return 0;
 1209                 }
 1210                 if (!IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
 1211                         return EADDRNOTAVAIL;
 1212                 sdl = malloc(sizeof *sdl, M_IFMADDR,
 1213                        M_NOWAIT|M_ZERO);
 1214                 if (sdl == NULL)
 1215                         return (ENOMEM);
 1216                 sdl->sdl_len = sizeof *sdl;
 1217                 sdl->sdl_family = AF_LINK;
 1218                 sdl->sdl_index = ifp->if_index;
 1219                 sdl->sdl_type = IFT_ETHER;
 1220                 sdl->sdl_alen = ETHER_ADDR_LEN;
 1221                 e_addr = LLADDR(sdl);
 1222                 ETHER_MAP_IPV6_MULTICAST(&sin6->sin6_addr, e_addr);
 1223                 *llsa = (struct sockaddr *)sdl;
 1224                 return 0;
 1225 #endif
 1226 
 1227         default:
 1228                 /*
 1229                  * Well, the text isn't quite right, but it's the name
 1230                  * that counts...
 1231                  */
 1232                 return EAFNOSUPPORT;
 1233         }
 1234 }
 1235 
 1236 static void*
 1237 ether_alloc(u_char type, struct ifnet *ifp)
 1238 {
 1239         struct arpcom   *ac;
 1240         
 1241         ac = malloc(sizeof(struct arpcom), M_ARPCOM, M_WAITOK | M_ZERO);
 1242         ac->ac_ifp = ifp;
 1243 
 1244         return (ac);
 1245 }
 1246 
 1247 static void
 1248 ether_free(void *com, u_char type)
 1249 {
 1250 
 1251         free(com, M_ARPCOM);
 1252 }
 1253 
 1254 static int
 1255 ether_modevent(module_t mod, int type, void *data)
 1256 {
 1257 
 1258         switch (type) {
 1259         case MOD_LOAD:
 1260                 if_register_com_alloc(IFT_ETHER, ether_alloc, ether_free);
 1261                 break;
 1262         case MOD_UNLOAD:
 1263                 if_deregister_com_alloc(IFT_ETHER);
 1264                 break;
 1265         default:
 1266                 return EOPNOTSUPP;
 1267         }
 1268 
 1269         return (0);
 1270 }
 1271 
 1272 static moduledata_t ether_mod = {
 1273         "ether",
 1274         ether_modevent,
 1275         0
 1276 };
 1277 
 1278 void
 1279 ether_vlan_mtap(struct bpf_if *bp, struct mbuf *m, void *data, u_int dlen)
 1280 {
 1281         struct ether_vlan_header vlan;
 1282         struct mbuf mv, mb;
 1283 
 1284         KASSERT((m->m_flags & M_VLANTAG) != 0,
 1285             ("%s: vlan information not present", __func__));
 1286         KASSERT(m->m_len >= sizeof(struct ether_header),
 1287             ("%s: mbuf not large enough for header", __func__));
 1288         bcopy(mtod(m, char *), &vlan, sizeof(struct ether_header));
 1289         vlan.evl_proto = vlan.evl_encap_proto;
 1290         vlan.evl_encap_proto = htons(ETHERTYPE_VLAN);
 1291         vlan.evl_tag = htons(m->m_pkthdr.ether_vtag);
 1292         m->m_len -= sizeof(struct ether_header);
 1293         m->m_data += sizeof(struct ether_header);
 1294         /*
 1295          * If a data link has been supplied by the caller, then we will need to
 1296          * re-create a stack allocated mbuf chain with the following structure:
 1297          *
 1298          * (1) mbuf #1 will contain the supplied data link
 1299          * (2) mbuf #2 will contain the vlan header
 1300          * (3) mbuf #3 will contain the original mbuf's packet data
 1301          *
 1302          * Otherwise, submit the packet and vlan header via bpf_mtap2().
 1303          */
 1304         if (data != NULL) {
 1305                 mv.m_next = m;
 1306                 mv.m_data = (caddr_t)&vlan;
 1307                 mv.m_len = sizeof(vlan);
 1308                 mb.m_next = &mv;
 1309                 mb.m_data = data;
 1310                 mb.m_len = dlen;
 1311                 bpf_mtap(bp, &mb);
 1312         } else
 1313                 bpf_mtap2(bp, &vlan, sizeof(vlan), m);
 1314         m->m_len += sizeof(struct ether_header);
 1315         m->m_data -= sizeof(struct ether_header);
 1316 }
 1317 
 1318 struct mbuf *
 1319 ether_vlanencap(struct mbuf *m, uint16_t tag)
 1320 {
 1321         struct ether_vlan_header *evl;
 1322 
 1323         M_PREPEND(m, ETHER_VLAN_ENCAP_LEN, M_DONTWAIT);
 1324         if (m == NULL)
 1325                 return (NULL);
 1326         /* M_PREPEND takes care of m_len, m_pkthdr.len for us */
 1327 
 1328         if (m->m_len < sizeof(*evl)) {
 1329                 m = m_pullup(m, sizeof(*evl));
 1330                 if (m == NULL)
 1331                         return (NULL);
 1332         }
 1333 
 1334         /*
 1335          * Transform the Ethernet header into an Ethernet header
 1336          * with 802.1Q encapsulation.
 1337          */
 1338         evl = mtod(m, struct ether_vlan_header *);
 1339         bcopy((char *)evl + ETHER_VLAN_ENCAP_LEN,
 1340             (char *)evl, ETHER_HDR_LEN - ETHER_TYPE_LEN);
 1341         evl->evl_encap_proto = htons(ETHERTYPE_VLAN);
 1342         evl->evl_tag = htons(tag);
 1343         return (m);
 1344 }
 1345 
 1346 DECLARE_MODULE(ether, ether_mod, SI_SUB_INIT_IF, SI_ORDER_ANY);
 1347 MODULE_VERSION(ether, 1);

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