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


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/net/if_ethersubr.c

Version: -  FREEBSD  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-2  -  FREEBSD-11-1  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-4  -  FREEBSD-10-3  -  FREEBSD-10-2  -  FREEBSD-10-1  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-3  -  FREEBSD-9-2  -  FREEBSD-9-1  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-4  -  FREEBSD-8-3  -  FREEBSD-8-2  -  FREEBSD-8-1  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-4  -  FREEBSD-7-3  -  FREEBSD-7-2  -  FREEBSD-7-1  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-4  -  FREEBSD-6-3  -  FREEBSD-6-2  -  FREEBSD-6-1  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-5  -  FREEBSD-5-4  -  FREEBSD-5-3  -  FREEBSD-5-2  -  FREEBSD-5-1  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1 
SearchContext: -  none  -  3  -  10 

    1 /*-
    2  * SPDX-License-Identifier: BSD-3-Clause
    3  *
    4  * Copyright (c) 1982, 1989, 1993
    5  *      The Regents of the University of California.  All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  * 1. Redistributions of source code must retain the above copyright
   11  *    notice, this list of conditions and the following disclaimer.
   12  * 2. Redistributions in binary form must reproduce the above copyright
   13  *    notice, this list of conditions and the following disclaimer in the
   14  *    documentation and/or other materials provided with the distribution.
   15  * 3. Neither the name of the University nor the names of its contributors
   16  *    may be used to endorse or promote products derived from this software
   17  *    without specific prior written permission.
   18  *
   19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   29  * SUCH DAMAGE.
   30  *
   31  *      @(#)if_ethersubr.c      8.1 (Berkeley) 6/10/93
   32  * $FreeBSD: releng/12.0/sys/net/if_ethersubr.c 338324 2018-08-26 12:51:46Z markm $
   33  */
   34 
   35 #include "opt_inet.h"
   36 #include "opt_inet6.h"
   37 #include "opt_netgraph.h"
   38 #include "opt_mbuf_profiling.h"
   39 #include "opt_rss.h"
   40 
   41 #include <sys/param.h>
   42 #include <sys/systm.h>
   43 #include <sys/bus.h>
   44 #include <sys/eventhandler.h>
   45 #include <sys/kernel.h>
   46 #include <sys/lock.h>
   47 #include <sys/malloc.h>
   48 #include <sys/module.h>
   49 #include <sys/mbuf.h>
   50 #include <sys/priv.h>
   51 #include <sys/random.h>
   52 #include <sys/socket.h>
   53 #include <sys/sockio.h>
   54 #include <sys/sysctl.h>
   55 #include <sys/uuid.h>
   56 
   57 #include <net/if.h>
   58 #include <net/if_var.h>
   59 #include <net/if_arp.h>
   60 #include <net/netisr.h>
   61 #include <net/route.h>
   62 #include <net/if_llc.h>
   63 #include <net/if_dl.h>
   64 #include <net/if_types.h>
   65 #include <net/bpf.h>
   66 #include <net/ethernet.h>
   67 #include <net/if_bridgevar.h>
   68 #include <net/if_vlan_var.h>
   69 #include <net/if_llatbl.h>
   70 #include <net/pfil.h>
   71 #include <net/rss_config.h>
   72 #include <net/vnet.h>
   73 
   74 #include <netpfil/pf/pf_mtag.h>
   75 
   76 #if defined(INET) || defined(INET6)
   77 #include <netinet/in.h>
   78 #include <netinet/in_var.h>
   79 #include <netinet/if_ether.h>
   80 #include <netinet/ip_carp.h>
   81 #include <netinet/ip_var.h>
   82 #endif
   83 #ifdef INET6
   84 #include <netinet6/nd6.h>
   85 #endif
   86 #include <security/mac/mac_framework.h>
   87 
   88 #ifdef CTASSERT
   89 CTASSERT(sizeof (struct ether_header) == ETHER_ADDR_LEN * 2 + 2);
   90 CTASSERT(sizeof (struct ether_addr) == ETHER_ADDR_LEN);
   91 #endif
   92 
   93 VNET_DEFINE(struct pfil_head, link_pfil_hook);  /* Packet filter hooks */
   94 
   95 /* netgraph node hooks for ng_ether(4) */
   96 void    (*ng_ether_input_p)(struct ifnet *ifp, struct mbuf **mp);
   97 void    (*ng_ether_input_orphan_p)(struct ifnet *ifp, struct mbuf *m);
   98 int     (*ng_ether_output_p)(struct ifnet *ifp, struct mbuf **mp);
   99 void    (*ng_ether_attach_p)(struct ifnet *ifp);
  100 void    (*ng_ether_detach_p)(struct ifnet *ifp);
  101 
  102 void    (*vlan_input_p)(struct ifnet *, struct mbuf *);
  103 
  104 /* if_bridge(4) support */
  105 void    (*bridge_dn_p)(struct mbuf *, struct ifnet *);
  106 
  107 /* if_lagg(4) support */
  108 struct mbuf *(*lagg_input_p)(struct ifnet *, struct mbuf *); 
  109 
  110 static const u_char etherbroadcastaddr[ETHER_ADDR_LEN] =
  111                         { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
  112 
  113 static  int ether_resolvemulti(struct ifnet *, struct sockaddr **,
  114                 struct sockaddr *);
  115 #ifdef VIMAGE
  116 static  void ether_reassign(struct ifnet *, struct vnet *, char *);
  117 #endif
  118 static  int ether_requestencap(struct ifnet *, struct if_encap_req *);
  119 
  120 
  121 #define senderr(e) do { error = (e); goto bad;} while (0)
  122 
  123 static void
  124 update_mbuf_csumflags(struct mbuf *src, struct mbuf *dst)
  125 {
  126         int csum_flags = 0;
  127 
  128         if (src->m_pkthdr.csum_flags & CSUM_IP)
  129                 csum_flags |= (CSUM_IP_CHECKED|CSUM_IP_VALID);
  130         if (src->m_pkthdr.csum_flags & CSUM_DELAY_DATA)
  131                 csum_flags |= (CSUM_DATA_VALID|CSUM_PSEUDO_HDR);
  132         if (src->m_pkthdr.csum_flags & CSUM_SCTP)
  133                 csum_flags |= CSUM_SCTP_VALID;
  134         dst->m_pkthdr.csum_flags |= csum_flags;
  135         if (csum_flags & CSUM_DATA_VALID)
  136                 dst->m_pkthdr.csum_data = 0xffff;
  137 }
  138 
  139 /*
  140  * Handle link-layer encapsulation requests.
  141  */
  142 static int
  143 ether_requestencap(struct ifnet *ifp, struct if_encap_req *req)
  144 {
  145         struct ether_header *eh;
  146         struct arphdr *ah;
  147         uint16_t etype;
  148         const u_char *lladdr;
  149 
  150         if (req->rtype != IFENCAP_LL)
  151                 return (EOPNOTSUPP);
  152 
  153         if (req->bufsize < ETHER_HDR_LEN)
  154                 return (ENOMEM);
  155 
  156         eh = (struct ether_header *)req->buf;
  157         lladdr = req->lladdr;
  158         req->lladdr_off = 0;
  159 
  160         switch (req->family) {
  161         case AF_INET:
  162                 etype = htons(ETHERTYPE_IP);
  163                 break;
  164         case AF_INET6:
  165                 etype = htons(ETHERTYPE_IPV6);
  166                 break;
  167         case AF_ARP:
  168                 ah = (struct arphdr *)req->hdata;
  169                 ah->ar_hrd = htons(ARPHRD_ETHER);
  170 
  171                 switch(ntohs(ah->ar_op)) {
  172                 case ARPOP_REVREQUEST:
  173                 case ARPOP_REVREPLY:
  174                         etype = htons(ETHERTYPE_REVARP);
  175                         break;
  176                 case ARPOP_REQUEST:
  177                 case ARPOP_REPLY:
  178                 default:
  179                         etype = htons(ETHERTYPE_ARP);
  180                         break;
  181                 }
  182 
  183                 if (req->flags & IFENCAP_FLAG_BROADCAST)
  184                         lladdr = ifp->if_broadcastaddr;
  185                 break;
  186         default:
  187                 return (EAFNOSUPPORT);
  188         }
  189 
  190         memcpy(&eh->ether_type, &etype, sizeof(eh->ether_type));
  191         memcpy(eh->ether_dhost, lladdr, ETHER_ADDR_LEN);
  192         memcpy(eh->ether_shost, IF_LLADDR(ifp), ETHER_ADDR_LEN);
  193         req->bufsize = sizeof(struct ether_header);
  194 
  195         return (0);
  196 }
  197 
  198 
  199 static int
  200 ether_resolve_addr(struct ifnet *ifp, struct mbuf *m,
  201         const struct sockaddr *dst, struct route *ro, u_char *phdr,
  202         uint32_t *pflags, struct llentry **plle)
  203 {
  204         struct ether_header *eh;
  205         uint32_t lleflags = 0;
  206         int error = 0;
  207 #if defined(INET) || defined(INET6)
  208         uint16_t etype;
  209 #endif
  210 
  211         if (plle)
  212                 *plle = NULL;
  213         eh = (struct ether_header *)phdr;
  214 
  215         switch (dst->sa_family) {
  216 #ifdef INET
  217         case AF_INET:
  218                 if ((m->m_flags & (M_BCAST | M_MCAST)) == 0)
  219                         error = arpresolve(ifp, 0, m, dst, phdr, &lleflags,
  220                             plle);
  221                 else {
  222                         if (m->m_flags & M_BCAST)
  223                                 memcpy(eh->ether_dhost, ifp->if_broadcastaddr,
  224                                     ETHER_ADDR_LEN);
  225                         else {
  226                                 const struct in_addr *a;
  227                                 a = &(((const struct sockaddr_in *)dst)->sin_addr);
  228                                 ETHER_MAP_IP_MULTICAST(a, eh->ether_dhost);
  229                         }
  230                         etype = htons(ETHERTYPE_IP);
  231                         memcpy(&eh->ether_type, &etype, sizeof(etype));
  232                         memcpy(eh->ether_shost, IF_LLADDR(ifp), ETHER_ADDR_LEN);
  233                 }
  234                 break;
  235 #endif
  236 #ifdef INET6
  237         case AF_INET6:
  238                 if ((m->m_flags & M_MCAST) == 0)
  239                         error = nd6_resolve(ifp, 0, m, dst, phdr, &lleflags,
  240                             plle);
  241                 else {
  242                         const struct in6_addr *a6;
  243                         a6 = &(((const struct sockaddr_in6 *)dst)->sin6_addr);
  244                         ETHER_MAP_IPV6_MULTICAST(a6, eh->ether_dhost);
  245                         etype = htons(ETHERTYPE_IPV6);
  246                         memcpy(&eh->ether_type, &etype, sizeof(etype));
  247                         memcpy(eh->ether_shost, IF_LLADDR(ifp), ETHER_ADDR_LEN);
  248                 }
  249                 break;
  250 #endif
  251         default:
  252                 if_printf(ifp, "can't handle af%d\n", dst->sa_family);
  253                 if (m != NULL)
  254                         m_freem(m);
  255                 return (EAFNOSUPPORT);
  256         }
  257 
  258         if (error == EHOSTDOWN) {
  259                 if (ro != NULL && (ro->ro_flags & RT_HAS_GW) != 0)
  260                         error = EHOSTUNREACH;
  261         }
  262 
  263         if (error != 0)
  264                 return (error);
  265 
  266         *pflags = RT_MAY_LOOP;
  267         if (lleflags & LLE_IFADDR)
  268                 *pflags |= RT_L2_ME;
  269 
  270         return (0);
  271 }
  272 
  273 /*
  274  * Ethernet output routine.
  275  * Encapsulate a packet of type family for the local net.
  276  * Use trailer local net encapsulation if enough data in first
  277  * packet leaves a multiple of 512 bytes of data in remainder.
  278  */
  279 int
  280 ether_output(struct ifnet *ifp, struct mbuf *m,
  281         const struct sockaddr *dst, struct route *ro)
  282 {
  283         int error = 0;
  284         char linkhdr[ETHER_HDR_LEN], *phdr;
  285         struct ether_header *eh;
  286         struct pf_mtag *t;
  287         int loop_copy = 1;
  288         int hlen;       /* link layer header length */
  289         uint32_t pflags;
  290         struct llentry *lle = NULL;
  291         int addref = 0;
  292 
  293         phdr = NULL;
  294         pflags = 0;
  295         if (ro != NULL) {
  296                 /* XXX BPF uses ro_prepend */
  297                 if (ro->ro_prepend != NULL) {
  298                         phdr = ro->ro_prepend;
  299                         hlen = ro->ro_plen;
  300                 } else if (!(m->m_flags & (M_BCAST | M_MCAST))) {
  301                         if ((ro->ro_flags & RT_LLE_CACHE) != 0) {
  302                                 lle = ro->ro_lle;
  303                                 if (lle != NULL &&
  304                                     (lle->la_flags & LLE_VALID) == 0) {
  305                                         LLE_FREE(lle);
  306                                         lle = NULL;     /* redundant */
  307                                         ro->ro_lle = NULL;
  308                                 }
  309                                 if (lle == NULL) {
  310                                         /* if we lookup, keep cache */
  311                                         addref = 1;
  312                                 } else
  313                                         /*
  314                                          * Notify LLE code that
  315                                          * the entry was used
  316                                          * by datapath.
  317                                          */
  318                                         llentry_mark_used(lle);
  319                         }
  320                         if (lle != NULL) {
  321                                 phdr = lle->r_linkdata;
  322                                 hlen = lle->r_hdrlen;
  323                                 pflags = lle->r_flags;
  324                         }
  325                 }
  326         }
  327 
  328 #ifdef MAC
  329         error = mac_ifnet_check_transmit(ifp, m);
  330         if (error)
  331                 senderr(error);
  332 #endif
  333 
  334         M_PROFILE(m);
  335         if (ifp->if_flags & IFF_MONITOR)
  336                 senderr(ENETDOWN);
  337         if (!((ifp->if_flags & IFF_UP) &&
  338             (ifp->if_drv_flags & IFF_DRV_RUNNING)))
  339                 senderr(ENETDOWN);
  340 
  341         if (phdr == NULL) {
  342                 /* No prepend data supplied. Try to calculate ourselves. */
  343                 phdr = linkhdr;
  344                 hlen = ETHER_HDR_LEN;
  345                 error = ether_resolve_addr(ifp, m, dst, ro, phdr, &pflags,
  346                     addref ? &lle : NULL);
  347                 if (addref && lle != NULL)
  348                         ro->ro_lle = lle;
  349                 if (error != 0)
  350                         return (error == EWOULDBLOCK ? 0 : error);
  351         }
  352 
  353         if ((pflags & RT_L2_ME) != 0) {
  354                 update_mbuf_csumflags(m, m);
  355                 return (if_simloop(ifp, m, dst->sa_family, 0));
  356         }
  357         loop_copy = pflags & RT_MAY_LOOP;
  358 
  359         /*
  360          * Add local net header.  If no space in first mbuf,
  361          * allocate another.
  362          *
  363          * Note that we do prepend regardless of RT_HAS_HEADER flag.
  364          * This is done because BPF code shifts m_data pointer
  365          * to the end of ethernet header prior to calling if_output().
  366          */
  367         M_PREPEND(m, hlen, M_NOWAIT);
  368         if (m == NULL)
  369                 senderr(ENOBUFS);
  370         if ((pflags & RT_HAS_HEADER) == 0) {
  371                 eh = mtod(m, struct ether_header *);
  372                 memcpy(eh, phdr, hlen);
  373         }
  374 
  375         /*
  376          * If a simplex interface, and the packet is being sent to our
  377          * Ethernet address or a broadcast address, loopback a copy.
  378          * XXX To make a simplex device behave exactly like a duplex
  379          * device, we should copy in the case of sending to our own
  380          * ethernet address (thus letting the original actually appear
  381          * on the wire). However, we don't do that here for security
  382          * reasons and compatibility with the original behavior.
  383          */
  384         if ((m->m_flags & M_BCAST) && loop_copy && (ifp->if_flags & IFF_SIMPLEX) &&
  385             ((t = pf_find_mtag(m)) == NULL || !t->routed)) {
  386                 struct mbuf *n;
  387 
  388                 /*
  389                  * Because if_simloop() modifies the packet, we need a
  390                  * writable copy through m_dup() instead of a readonly
  391                  * one as m_copy[m] would give us. The alternative would
  392                  * be to modify if_simloop() to handle the readonly mbuf,
  393                  * but performancewise it is mostly equivalent (trading
  394                  * extra data copying vs. extra locking).
  395                  *
  396                  * XXX This is a local workaround.  A number of less
  397                  * often used kernel parts suffer from the same bug.
  398                  * See PR kern/105943 for a proposed general solution.
  399                  */
  400                 if ((n = m_dup(m, M_NOWAIT)) != NULL) {
  401                         update_mbuf_csumflags(m, n);
  402                         (void)if_simloop(ifp, n, dst->sa_family, hlen);
  403                 } else
  404                         if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
  405         }
  406 
  407        /*
  408         * Bridges require special output handling.
  409         */
  410         if (ifp->if_bridge) {
  411                 BRIDGE_OUTPUT(ifp, m, error);
  412                 return (error);
  413         }
  414 
  415 #if defined(INET) || defined(INET6)
  416         if (ifp->if_carp &&
  417             (error = (*carp_output_p)(ifp, m, dst)))
  418                 goto bad;
  419 #endif
  420 
  421         /* Handle ng_ether(4) processing, if any */
  422         if (ifp->if_l2com != NULL) {
  423                 KASSERT(ng_ether_output_p != NULL,
  424                     ("ng_ether_output_p is NULL"));
  425                 if ((error = (*ng_ether_output_p)(ifp, &m)) != 0) {
  426 bad:                    if (m != NULL)
  427                                 m_freem(m);
  428                         return (error);
  429                 }
  430                 if (m == NULL)
  431                         return (0);
  432         }
  433 
  434         /* Continue with link-layer output */
  435         return ether_output_frame(ifp, m);
  436 }
  437 
  438 static bool
  439 ether_set_pcp(struct mbuf **mp, struct ifnet *ifp, uint8_t pcp)
  440 {
  441         struct ether_header *eh;
  442 
  443         eh = mtod(*mp, struct ether_header *);
  444         if (ntohs(eh->ether_type) == ETHERTYPE_VLAN ||
  445             ether_8021q_frame(mp, ifp, ifp, 0, pcp))
  446                 return (true);
  447         if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
  448         return (false);
  449 }
  450 
  451 /*
  452  * Ethernet link layer output routine to send a raw frame to the device.
  453  *
  454  * This assumes that the 14 byte Ethernet header is present and contiguous
  455  * in the first mbuf (if BRIDGE'ing).
  456  */
  457 int
  458 ether_output_frame(struct ifnet *ifp, struct mbuf *m)
  459 {
  460         int error;
  461         uint8_t pcp;
  462 
  463         pcp = ifp->if_pcp;
  464         if (pcp != IFNET_PCP_NONE && ifp->if_type != IFT_L2VLAN &&
  465             !ether_set_pcp(&m, ifp, pcp))
  466                 return (0);
  467 
  468         if (PFIL_HOOKED(&V_link_pfil_hook)) {
  469                 error = pfil_run_hooks(&V_link_pfil_hook, &m, ifp,
  470                     PFIL_OUT, 0, NULL);
  471                 if (error != 0)
  472                         return (EACCES);
  473 
  474                 if (m == NULL)
  475                         return (0);
  476         }
  477 
  478         /*
  479          * Queue message on interface, update output statistics if
  480          * successful, and start output if interface not yet active.
  481          */
  482         return ((ifp->if_transmit)(ifp, m));
  483 }
  484 
  485 /*
  486  * Process a received Ethernet packet; the packet is in the
  487  * mbuf chain m with the ethernet header at the front.
  488  */
  489 static void
  490 ether_input_internal(struct ifnet *ifp, struct mbuf *m)
  491 {
  492         struct ether_header *eh;
  493         u_short etype;
  494 
  495         if ((ifp->if_flags & IFF_UP) == 0) {
  496                 m_freem(m);
  497                 return;
  498         }
  499 #ifdef DIAGNOSTIC
  500         if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
  501                 if_printf(ifp, "discard frame at !IFF_DRV_RUNNING\n");
  502                 m_freem(m);
  503                 return;
  504         }
  505 #endif
  506         if (m->m_len < ETHER_HDR_LEN) {
  507                 /* XXX maybe should pullup? */
  508                 if_printf(ifp, "discard frame w/o leading ethernet "
  509                                 "header (len %u pkt len %u)\n",
  510                                 m->m_len, m->m_pkthdr.len);
  511                 if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
  512                 m_freem(m);
  513                 return;
  514         }
  515         eh = mtod(m, struct ether_header *);
  516         etype = ntohs(eh->ether_type);
  517         random_harvest_queue_ether(m, sizeof(*m));
  518 
  519         CURVNET_SET_QUIET(ifp->if_vnet);
  520 
  521         if (ETHER_IS_MULTICAST(eh->ether_dhost)) {
  522                 if (ETHER_IS_BROADCAST(eh->ether_dhost))
  523                         m->m_flags |= M_BCAST;
  524                 else
  525                         m->m_flags |= M_MCAST;
  526                 if_inc_counter(ifp, IFCOUNTER_IMCASTS, 1);
  527         }
  528 
  529 #ifdef MAC
  530         /*
  531          * Tag the mbuf with an appropriate MAC label before any other
  532          * consumers can get to it.
  533          */
  534         mac_ifnet_create_mbuf(ifp, m);
  535 #endif
  536 
  537         /*
  538          * Give bpf a chance at the packet.
  539          */
  540         ETHER_BPF_MTAP(ifp, m);
  541 
  542         /*
  543          * If the CRC is still on the packet, trim it off. We do this once
  544          * and once only in case we are re-entered. Nothing else on the
  545          * Ethernet receive path expects to see the FCS.
  546          */
  547         if (m->m_flags & M_HASFCS) {
  548                 m_adj(m, -ETHER_CRC_LEN);
  549                 m->m_flags &= ~M_HASFCS;
  550         }
  551 
  552         if (!(ifp->if_capenable & IFCAP_HWSTATS))
  553                 if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
  554 
  555         /* Allow monitor mode to claim this frame, after stats are updated. */
  556         if (ifp->if_flags & IFF_MONITOR) {
  557                 m_freem(m);
  558                 CURVNET_RESTORE();
  559                 return;
  560         }
  561 
  562         /* Handle input from a lagg(4) port */
  563         if (ifp->if_type == IFT_IEEE8023ADLAG) {
  564                 KASSERT(lagg_input_p != NULL,
  565                     ("%s: if_lagg not loaded!", __func__));
  566                 m = (*lagg_input_p)(ifp, m);
  567                 if (m != NULL)
  568                         ifp = m->m_pkthdr.rcvif;
  569                 else {
  570                         CURVNET_RESTORE();
  571                         return;
  572                 }
  573         }
  574 
  575         /*
  576          * If the hardware did not process an 802.1Q tag, do this now,
  577          * to allow 802.1P priority frames to be passed to the main input
  578          * path correctly.
  579          * TODO: Deal with Q-in-Q frames, but not arbitrary nesting levels.
  580          */
  581         if ((m->m_flags & M_VLANTAG) == 0 && etype == ETHERTYPE_VLAN) {
  582                 struct ether_vlan_header *evl;
  583 
  584                 if (m->m_len < sizeof(*evl) &&
  585                     (m = m_pullup(m, sizeof(*evl))) == NULL) {
  586 #ifdef DIAGNOSTIC
  587                         if_printf(ifp, "cannot pullup VLAN header\n");
  588 #endif
  589                         if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
  590                         CURVNET_RESTORE();
  591                         return;
  592                 }
  593 
  594                 evl = mtod(m, struct ether_vlan_header *);
  595                 m->m_pkthdr.ether_vtag = ntohs(evl->evl_tag);
  596                 m->m_flags |= M_VLANTAG;
  597 
  598                 bcopy((char *)evl, (char *)evl + ETHER_VLAN_ENCAP_LEN,
  599                     ETHER_HDR_LEN - ETHER_TYPE_LEN);
  600                 m_adj(m, ETHER_VLAN_ENCAP_LEN);
  601                 eh = mtod(m, struct ether_header *);
  602         }
  603 
  604         M_SETFIB(m, ifp->if_fib);
  605 
  606         /* Allow ng_ether(4) to claim this frame. */
  607         if (ifp->if_l2com != NULL) {
  608                 KASSERT(ng_ether_input_p != NULL,
  609                     ("%s: ng_ether_input_p is NULL", __func__));
  610                 m->m_flags &= ~M_PROMISC;
  611                 (*ng_ether_input_p)(ifp, &m);
  612                 if (m == NULL) {
  613                         CURVNET_RESTORE();
  614                         return;
  615                 }
  616                 eh = mtod(m, struct ether_header *);
  617         }
  618 
  619         /*
  620          * Allow if_bridge(4) to claim this frame.
  621          * The BRIDGE_INPUT() macro will update ifp if the bridge changed it
  622          * and the frame should be delivered locally.
  623          */
  624         if (ifp->if_bridge != NULL) {
  625                 m->m_flags &= ~M_PROMISC;
  626                 BRIDGE_INPUT(ifp, m);
  627                 if (m == NULL) {
  628                         CURVNET_RESTORE();
  629                         return;
  630                 }
  631                 eh = mtod(m, struct ether_header *);
  632         }
  633 
  634 #if defined(INET) || defined(INET6)
  635         /*
  636          * Clear M_PROMISC on frame so that carp(4) will see it when the
  637          * mbuf flows up to Layer 3.
  638          * FreeBSD's implementation of carp(4) uses the inprotosw
  639          * to dispatch IPPROTO_CARP. carp(4) also allocates its own
  640          * Ethernet addresses of the form 00:00:5e:00:01:xx, which
  641          * is outside the scope of the M_PROMISC test below.
  642          * TODO: Maintain a hash table of ethernet addresses other than
  643          * ether_dhost which may be active on this ifp.
  644          */
  645         if (ifp->if_carp && (*carp_forus_p)(ifp, eh->ether_dhost)) {
  646                 m->m_flags &= ~M_PROMISC;
  647         } else
  648 #endif
  649         {
  650                 /*
  651                  * If the frame received was not for our MAC address, set the
  652                  * M_PROMISC flag on the mbuf chain. The frame may need to
  653                  * be seen by the rest of the Ethernet input path in case of
  654                  * re-entry (e.g. bridge, vlan, netgraph) but should not be
  655                  * seen by upper protocol layers.
  656                  */
  657                 if (!ETHER_IS_MULTICAST(eh->ether_dhost) &&
  658                     bcmp(IF_LLADDR(ifp), eh->ether_dhost, ETHER_ADDR_LEN) != 0)
  659                         m->m_flags |= M_PROMISC;
  660         }
  661 
  662         ether_demux(ifp, m);
  663         CURVNET_RESTORE();
  664 }
  665 
  666 /*
  667  * Ethernet input dispatch; by default, direct dispatch here regardless of
  668  * global configuration.  However, if RSS is enabled, hook up RSS affinity
  669  * so that when deferred or hybrid dispatch is enabled, we can redistribute
  670  * load based on RSS.
  671  *
  672  * XXXRW: Would be nice if the ifnet passed up a flag indicating whether or
  673  * not it had already done work distribution via multi-queue.  Then we could
  674  * direct dispatch in the event load balancing was already complete and
  675  * handle the case of interfaces with different capabilities better.
  676  *
  677  * XXXRW: Sort of want an M_DISTRIBUTED flag to avoid multiple distributions
  678  * at multiple layers?
  679  *
  680  * XXXRW: For now, enable all this only if RSS is compiled in, although it
  681  * works fine without RSS.  Need to characterise the performance overhead
  682  * of the detour through the netisr code in the event the result is always
  683  * direct dispatch.
  684  */
  685 static void
  686 ether_nh_input(struct mbuf *m)
  687 {
  688 
  689         M_ASSERTPKTHDR(m);
  690         KASSERT(m->m_pkthdr.rcvif != NULL,
  691             ("%s: NULL interface pointer", __func__));
  692         ether_input_internal(m->m_pkthdr.rcvif, m);
  693 }
  694 
  695 static struct netisr_handler    ether_nh = {
  696         .nh_name = "ether",
  697         .nh_handler = ether_nh_input,
  698         .nh_proto = NETISR_ETHER,
  699 #ifdef RSS
  700         .nh_policy = NETISR_POLICY_CPU,
  701         .nh_dispatch = NETISR_DISPATCH_DIRECT,
  702         .nh_m2cpuid = rss_m2cpuid,
  703 #else
  704         .nh_policy = NETISR_POLICY_SOURCE,
  705         .nh_dispatch = NETISR_DISPATCH_DIRECT,
  706 #endif
  707 };
  708 
  709 static void
  710 ether_init(__unused void *arg)
  711 {
  712 
  713         netisr_register(&ether_nh);
  714 }
  715 SYSINIT(ether, SI_SUB_INIT_IF, SI_ORDER_ANY, ether_init, NULL);
  716 
  717 static void
  718 vnet_ether_init(__unused void *arg)
  719 {
  720         int i;
  721 
  722         /* Initialize packet filter hooks. */
  723         V_link_pfil_hook.ph_type = PFIL_TYPE_AF;
  724         V_link_pfil_hook.ph_af = AF_LINK;
  725         if ((i = pfil_head_register(&V_link_pfil_hook)) != 0)
  726                 printf("%s: WARNING: unable to register pfil link hook, "
  727                         "error %d\n", __func__, i);
  728 #ifdef VIMAGE
  729         netisr_register_vnet(&ether_nh);
  730 #endif
  731 }
  732 VNET_SYSINIT(vnet_ether_init, SI_SUB_PROTO_IF, SI_ORDER_ANY,
  733     vnet_ether_init, NULL);
  734  
  735 #ifdef VIMAGE
  736 static void
  737 vnet_ether_pfil_destroy(__unused void *arg)
  738 {
  739         int i;
  740 
  741         if ((i = pfil_head_unregister(&V_link_pfil_hook)) != 0)
  742                 printf("%s: WARNING: unable to unregister pfil link hook, "
  743                         "error %d\n", __func__, i);
  744 }
  745 VNET_SYSUNINIT(vnet_ether_pfil_uninit, SI_SUB_PROTO_PFIL, SI_ORDER_ANY,
  746     vnet_ether_pfil_destroy, NULL);
  747 
  748 static void
  749 vnet_ether_destroy(__unused void *arg)
  750 {
  751 
  752         netisr_unregister_vnet(&ether_nh);
  753 }
  754 VNET_SYSUNINIT(vnet_ether_uninit, SI_SUB_PROTO_IF, SI_ORDER_ANY,
  755     vnet_ether_destroy, NULL);
  756 #endif
  757 
  758 
  759 
  760 static void
  761 ether_input(struct ifnet *ifp, struct mbuf *m)
  762 {
  763 
  764         struct mbuf *mn;
  765 
  766         /*
  767          * The drivers are allowed to pass in a chain of packets linked with
  768          * m_nextpkt. We split them up into separate packets here and pass
  769          * them up. This allows the drivers to amortize the receive lock.
  770          */
  771         while (m) {
  772                 mn = m->m_nextpkt;
  773                 m->m_nextpkt = NULL;
  774 
  775                 /*
  776                  * We will rely on rcvif being set properly in the deferred context,
  777                  * so assert it is correct here.
  778                  */
  779                 KASSERT(m->m_pkthdr.rcvif == ifp, ("%s: ifnet mismatch m %p "
  780                     "rcvif %p ifp %p", __func__, m, m->m_pkthdr.rcvif, ifp));
  781                 CURVNET_SET_QUIET(ifp->if_vnet);
  782                 netisr_dispatch(NETISR_ETHER, m);
  783                 CURVNET_RESTORE();
  784                 m = mn;
  785         }
  786 }
  787 
  788 /*
  789  * Upper layer processing for a received Ethernet packet.
  790  */
  791 void
  792 ether_demux(struct ifnet *ifp, struct mbuf *m)
  793 {
  794         struct ether_header *eh;
  795         int i, isr;
  796         u_short ether_type;
  797 
  798         KASSERT(ifp != NULL, ("%s: NULL interface pointer", __func__));
  799 
  800         /* Do not grab PROMISC frames in case we are re-entered. */
  801         if (PFIL_HOOKED(&V_link_pfil_hook) && !(m->m_flags & M_PROMISC)) {
  802                 i = pfil_run_hooks(&V_link_pfil_hook, &m, ifp, PFIL_IN, 0,
  803                     NULL);
  804 
  805                 if (i != 0 || m == NULL)
  806                         return;
  807         }
  808 
  809         eh = mtod(m, struct ether_header *);
  810         ether_type = ntohs(eh->ether_type);
  811 
  812         /*
  813          * If this frame has a VLAN tag other than 0, call vlan_input()
  814          * if its module is loaded. Otherwise, drop.
  815          */
  816         if ((m->m_flags & M_VLANTAG) &&
  817             EVL_VLANOFTAG(m->m_pkthdr.ether_vtag) != 0) {
  818                 if (ifp->if_vlantrunk == NULL) {
  819                         if_inc_counter(ifp, IFCOUNTER_NOPROTO, 1);
  820                         m_freem(m);
  821                         return;
  822                 }
  823                 KASSERT(vlan_input_p != NULL,("%s: VLAN not loaded!",
  824                     __func__));
  825                 /* Clear before possibly re-entering ether_input(). */
  826                 m->m_flags &= ~M_PROMISC;
  827                 (*vlan_input_p)(ifp, m);
  828                 return;
  829         }
  830 
  831         /*
  832          * Pass promiscuously received frames to the upper layer if the user
  833          * requested this by setting IFF_PPROMISC. Otherwise, drop them.
  834          */
  835         if ((ifp->if_flags & IFF_PPROMISC) == 0 && (m->m_flags & M_PROMISC)) {
  836                 m_freem(m);
  837                 return;
  838         }
  839 
  840         /*
  841          * Reset layer specific mbuf flags to avoid confusing upper layers.
  842          * Strip off Ethernet header.
  843          */
  844         m->m_flags &= ~M_VLANTAG;
  845         m_clrprotoflags(m);
  846         m_adj(m, ETHER_HDR_LEN);
  847 
  848         /*
  849          * Dispatch frame to upper layer.
  850          */
  851         switch (ether_type) {
  852 #ifdef INET
  853         case ETHERTYPE_IP:
  854                 isr = NETISR_IP;
  855                 break;
  856 
  857         case ETHERTYPE_ARP:
  858                 if (ifp->if_flags & IFF_NOARP) {
  859                         /* Discard packet if ARP is disabled on interface */
  860                         m_freem(m);
  861                         return;
  862                 }
  863                 isr = NETISR_ARP;
  864                 break;
  865 #endif
  866 #ifdef INET6
  867         case ETHERTYPE_IPV6:
  868                 isr = NETISR_IPV6;
  869                 break;
  870 #endif
  871         default:
  872                 goto discard;
  873         }
  874         netisr_dispatch(isr, m);
  875         return;
  876 
  877 discard:
  878         /*
  879          * Packet is to be discarded.  If netgraph is present,
  880          * hand the packet to it for last chance processing;
  881          * otherwise dispose of it.
  882          */
  883         if (ifp->if_l2com != NULL) {
  884                 KASSERT(ng_ether_input_orphan_p != NULL,
  885                     ("ng_ether_input_orphan_p is NULL"));
  886                 /*
  887                  * Put back the ethernet header so netgraph has a
  888                  * consistent view of inbound packets.
  889                  */
  890                 M_PREPEND(m, ETHER_HDR_LEN, M_NOWAIT);
  891                 (*ng_ether_input_orphan_p)(ifp, m);
  892                 return;
  893         }
  894         m_freem(m);
  895 }
  896 
  897 /*
  898  * Convert Ethernet address to printable (loggable) representation.
  899  * This routine is for compatibility; it's better to just use
  900  *
  901  *      printf("%6D", <pointer to address>, ":");
  902  *
  903  * since there's no static buffer involved.
  904  */
  905 char *
  906 ether_sprintf(const u_char *ap)
  907 {
  908         static char etherbuf[18];
  909         snprintf(etherbuf, sizeof (etherbuf), "%6D", ap, ":");
  910         return (etherbuf);
  911 }
  912 
  913 /*
  914  * Perform common duties while attaching to interface list
  915  */
  916 void
  917 ether_ifattach(struct ifnet *ifp, const u_int8_t *lla)
  918 {
  919         int i;
  920         struct ifaddr *ifa;
  921         struct sockaddr_dl *sdl;
  922 
  923         ifp->if_addrlen = ETHER_ADDR_LEN;
  924         ifp->if_hdrlen = ETHER_HDR_LEN;
  925         if_attach(ifp);
  926         ifp->if_mtu = ETHERMTU;
  927         ifp->if_output = ether_output;
  928         ifp->if_input = ether_input;
  929         ifp->if_resolvemulti = ether_resolvemulti;
  930         ifp->if_requestencap = ether_requestencap;
  931 #ifdef VIMAGE
  932         ifp->if_reassign = ether_reassign;
  933 #endif
  934         if (ifp->if_baudrate == 0)
  935                 ifp->if_baudrate = IF_Mbps(10);         /* just a default */
  936         ifp->if_broadcastaddr = etherbroadcastaddr;
  937 
  938         ifa = ifp->if_addr;
  939         KASSERT(ifa != NULL, ("%s: no lladdr!\n", __func__));
  940         sdl = (struct sockaddr_dl *)ifa->ifa_addr;
  941         sdl->sdl_type = IFT_ETHER;
  942         sdl->sdl_alen = ifp->if_addrlen;
  943         bcopy(lla, LLADDR(sdl), ifp->if_addrlen);
  944 
  945         if (ifp->if_hw_addr != NULL)
  946                 bcopy(lla, ifp->if_hw_addr, ifp->if_addrlen);
  947 
  948         bpfattach(ifp, DLT_EN10MB, ETHER_HDR_LEN);
  949         if (ng_ether_attach_p != NULL)
  950                 (*ng_ether_attach_p)(ifp);
  951 
  952         /* Announce Ethernet MAC address if non-zero. */
  953         for (i = 0; i < ifp->if_addrlen; i++)
  954                 if (lla[i] != 0)
  955                         break; 
  956         if (i != ifp->if_addrlen)
  957                 if_printf(ifp, "Ethernet address: %6D\n", lla, ":");
  958 
  959         uuid_ether_add(LLADDR(sdl));
  960 
  961         /* Add necessary bits are setup; announce it now. */
  962         EVENTHANDLER_INVOKE(ether_ifattach_event, ifp);
  963         if (IS_DEFAULT_VNET(curvnet))
  964                 devctl_notify("ETHERNET", ifp->if_xname, "IFATTACH", NULL);
  965 }
  966 
  967 /*
  968  * Perform common duties while detaching an Ethernet interface
  969  */
  970 void
  971 ether_ifdetach(struct ifnet *ifp)
  972 {
  973         struct sockaddr_dl *sdl;
  974 
  975         sdl = (struct sockaddr_dl *)(ifp->if_addr->ifa_addr);
  976         uuid_ether_del(LLADDR(sdl));
  977 
  978         if (ifp->if_l2com != NULL) {
  979                 KASSERT(ng_ether_detach_p != NULL,
  980                     ("ng_ether_detach_p is NULL"));
  981                 (*ng_ether_detach_p)(ifp);
  982         }
  983 
  984         bpfdetach(ifp);
  985         if_detach(ifp);
  986 }
  987 
  988 #ifdef VIMAGE
  989 void
  990 ether_reassign(struct ifnet *ifp, struct vnet *new_vnet, char *unused __unused)
  991 {
  992 
  993         if (ifp->if_l2com != NULL) {
  994                 KASSERT(ng_ether_detach_p != NULL,
  995                     ("ng_ether_detach_p is NULL"));
  996                 (*ng_ether_detach_p)(ifp);
  997         }
  998 
  999         if (ng_ether_attach_p != NULL) {
 1000                 CURVNET_SET_QUIET(new_vnet);
 1001                 (*ng_ether_attach_p)(ifp);
 1002                 CURVNET_RESTORE();
 1003         }
 1004 }
 1005 #endif
 1006 
 1007 SYSCTL_DECL(_net_link);
 1008 SYSCTL_NODE(_net_link, IFT_ETHER, ether, CTLFLAG_RW, 0, "Ethernet");
 1009 
 1010 #if 0
 1011 /*
 1012  * This is for reference.  We have a table-driven version
 1013  * of the little-endian crc32 generator, which is faster
 1014  * than the double-loop.
 1015  */
 1016 uint32_t
 1017 ether_crc32_le(const uint8_t *buf, size_t len)
 1018 {
 1019         size_t i;
 1020         uint32_t crc;
 1021         int bit;
 1022         uint8_t data;
 1023 
 1024         crc = 0xffffffff;       /* initial value */
 1025 
 1026         for (i = 0; i < len; i++) {
 1027                 for (data = *buf++, bit = 0; bit < 8; bit++, data >>= 1) {
 1028                         carry = (crc ^ data) & 1;
 1029                         crc >>= 1;
 1030                         if (carry)
 1031                                 crc = (crc ^ ETHER_CRC_POLY_LE);
 1032                 }
 1033         }
 1034 
 1035         return (crc);
 1036 }
 1037 #else
 1038 uint32_t
 1039 ether_crc32_le(const uint8_t *buf, size_t len)
 1040 {
 1041         static const uint32_t crctab[] = {
 1042                 0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac,
 1043                 0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
 1044                 0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c,
 1045                 0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c
 1046         };
 1047         size_t i;
 1048         uint32_t crc;
 1049 
 1050         crc = 0xffffffff;       /* initial value */
 1051 
 1052         for (i = 0; i < len; i++) {
 1053                 crc ^= buf[i];
 1054                 crc = (crc >> 4) ^ crctab[crc & 0xf];
 1055                 crc = (crc >> 4) ^ crctab[crc & 0xf];
 1056         }
 1057 
 1058         return (crc);
 1059 }
 1060 #endif
 1061 
 1062 uint32_t
 1063 ether_crc32_be(const uint8_t *buf, size_t len)
 1064 {
 1065         size_t i;
 1066         uint32_t crc, carry;
 1067         int bit;
 1068         uint8_t data;
 1069 
 1070         crc = 0xffffffff;       /* initial value */
 1071 
 1072         for (i = 0; i < len; i++) {
 1073                 for (data = *buf++, bit = 0; bit < 8; bit++, data >>= 1) {
 1074                         carry = ((crc & 0x80000000) ? 1 : 0) ^ (data & 0x01);
 1075                         crc <<= 1;
 1076                         if (carry)
 1077                                 crc = (crc ^ ETHER_CRC_POLY_BE) | carry;
 1078                 }
 1079         }
 1080 
 1081         return (crc);
 1082 }
 1083 
 1084 int
 1085 ether_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
 1086 {
 1087         struct ifaddr *ifa = (struct ifaddr *) data;
 1088         struct ifreq *ifr = (struct ifreq *) data;
 1089         int error = 0;
 1090 
 1091         switch (command) {
 1092         case SIOCSIFADDR:
 1093                 ifp->if_flags |= IFF_UP;
 1094 
 1095                 switch (ifa->ifa_addr->sa_family) {
 1096 #ifdef INET
 1097                 case AF_INET:
 1098                         ifp->if_init(ifp->if_softc);    /* before arpwhohas */
 1099                         arp_ifinit(ifp, ifa);
 1100                         break;
 1101 #endif
 1102                 default:
 1103                         ifp->if_init(ifp->if_softc);
 1104                         break;
 1105                 }
 1106                 break;
 1107 
 1108         case SIOCGIFADDR:
 1109                 bcopy(IF_LLADDR(ifp), &ifr->ifr_addr.sa_data[0],
 1110                     ETHER_ADDR_LEN);
 1111                 break;
 1112 
 1113         case SIOCSIFMTU:
 1114                 /*
 1115                  * Set the interface MTU.
 1116                  */
 1117                 if (ifr->ifr_mtu > ETHERMTU) {
 1118                         error = EINVAL;
 1119                 } else {
 1120                         ifp->if_mtu = ifr->ifr_mtu;
 1121                 }
 1122                 break;
 1123 
 1124         case SIOCSLANPCP:
 1125                 error = priv_check(curthread, PRIV_NET_SETLANPCP);
 1126                 if (error != 0)
 1127                         break;
 1128                 if (ifr->ifr_lan_pcp > 7 &&
 1129                     ifr->ifr_lan_pcp != IFNET_PCP_NONE) {
 1130                         error = EINVAL;
 1131                 } else {
 1132                         ifp->if_pcp = ifr->ifr_lan_pcp;
 1133                         /* broadcast event about PCP change */
 1134                         EVENTHANDLER_INVOKE(ifnet_event, ifp, IFNET_EVENT_PCP);
 1135                 }
 1136                 break;
 1137 
 1138         case SIOCGLANPCP:
 1139                 ifr->ifr_lan_pcp = ifp->if_pcp;
 1140                 break;
 1141 
 1142         default:
 1143                 error = EINVAL;                 /* XXX netbsd has ENOTTY??? */
 1144                 break;
 1145         }
 1146         return (error);
 1147 }
 1148 
 1149 static int
 1150 ether_resolvemulti(struct ifnet *ifp, struct sockaddr **llsa,
 1151         struct sockaddr *sa)
 1152 {
 1153         struct sockaddr_dl *sdl;
 1154 #ifdef INET
 1155         struct sockaddr_in *sin;
 1156 #endif
 1157 #ifdef INET6
 1158         struct sockaddr_in6 *sin6;
 1159 #endif
 1160         u_char *e_addr;
 1161 
 1162         switch(sa->sa_family) {
 1163         case AF_LINK:
 1164                 /*
 1165                  * No mapping needed. Just check that it's a valid MC address.
 1166                  */
 1167                 sdl = (struct sockaddr_dl *)sa;
 1168                 e_addr = LLADDR(sdl);
 1169                 if (!ETHER_IS_MULTICAST(e_addr))
 1170                         return EADDRNOTAVAIL;
 1171                 *llsa = NULL;
 1172                 return 0;
 1173 
 1174 #ifdef INET
 1175         case AF_INET:
 1176                 sin = (struct sockaddr_in *)sa;
 1177                 if (!IN_MULTICAST(ntohl(sin->sin_addr.s_addr)))
 1178                         return EADDRNOTAVAIL;
 1179                 sdl = link_init_sdl(ifp, *llsa, IFT_ETHER);
 1180                 sdl->sdl_alen = ETHER_ADDR_LEN;
 1181                 e_addr = LLADDR(sdl);
 1182                 ETHER_MAP_IP_MULTICAST(&sin->sin_addr, e_addr);
 1183                 *llsa = (struct sockaddr *)sdl;
 1184                 return 0;
 1185 #endif
 1186 #ifdef INET6
 1187         case AF_INET6:
 1188                 sin6 = (struct sockaddr_in6 *)sa;
 1189                 if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) {
 1190                         /*
 1191                          * An IP6 address of 0 means listen to all
 1192                          * of the Ethernet multicast address used for IP6.
 1193                          * (This is used for multicast routers.)
 1194                          */
 1195                         ifp->if_flags |= IFF_ALLMULTI;
 1196                         *llsa = NULL;
 1197                         return 0;
 1198                 }
 1199                 if (!IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
 1200                         return EADDRNOTAVAIL;
 1201                 sdl = link_init_sdl(ifp, *llsa, IFT_ETHER);
 1202                 sdl->sdl_alen = ETHER_ADDR_LEN;
 1203                 e_addr = LLADDR(sdl);
 1204                 ETHER_MAP_IPV6_MULTICAST(&sin6->sin6_addr, e_addr);
 1205                 *llsa = (struct sockaddr *)sdl;
 1206                 return 0;
 1207 #endif
 1208 
 1209         default:
 1210                 /*
 1211                  * Well, the text isn't quite right, but it's the name
 1212                  * that counts...
 1213                  */
 1214                 return EAFNOSUPPORT;
 1215         }
 1216 }
 1217 
 1218 static moduledata_t ether_mod = {
 1219         .name = "ether",
 1220 };
 1221 
 1222 void
 1223 ether_vlan_mtap(struct bpf_if *bp, struct mbuf *m, void *data, u_int dlen)
 1224 {
 1225         struct ether_vlan_header vlan;
 1226         struct mbuf mv, mb;
 1227 
 1228         KASSERT((m->m_flags & M_VLANTAG) != 0,
 1229             ("%s: vlan information not present", __func__));
 1230         KASSERT(m->m_len >= sizeof(struct ether_header),
 1231             ("%s: mbuf not large enough for header", __func__));
 1232         bcopy(mtod(m, char *), &vlan, sizeof(struct ether_header));
 1233         vlan.evl_proto = vlan.evl_encap_proto;
 1234         vlan.evl_encap_proto = htons(ETHERTYPE_VLAN);
 1235         vlan.evl_tag = htons(m->m_pkthdr.ether_vtag);
 1236         m->m_len -= sizeof(struct ether_header);
 1237         m->m_data += sizeof(struct ether_header);
 1238         /*
 1239          * If a data link has been supplied by the caller, then we will need to
 1240          * re-create a stack allocated mbuf chain with the following structure:
 1241          *
 1242          * (1) mbuf #1 will contain the supplied data link
 1243          * (2) mbuf #2 will contain the vlan header
 1244          * (3) mbuf #3 will contain the original mbuf's packet data
 1245          *
 1246          * Otherwise, submit the packet and vlan header via bpf_mtap2().
 1247          */
 1248         if (data != NULL) {
 1249                 mv.m_next = m;
 1250                 mv.m_data = (caddr_t)&vlan;
 1251                 mv.m_len = sizeof(vlan);
 1252                 mb.m_next = &mv;
 1253                 mb.m_data = data;
 1254                 mb.m_len = dlen;
 1255                 bpf_mtap(bp, &mb);
 1256         } else
 1257                 bpf_mtap2(bp, &vlan, sizeof(vlan), m);
 1258         m->m_len += sizeof(struct ether_header);
 1259         m->m_data -= sizeof(struct ether_header);
 1260 }
 1261 
 1262 struct mbuf *
 1263 ether_vlanencap(struct mbuf *m, uint16_t tag)
 1264 {
 1265         struct ether_vlan_header *evl;
 1266 
 1267         M_PREPEND(m, ETHER_VLAN_ENCAP_LEN, M_NOWAIT);
 1268         if (m == NULL)
 1269                 return (NULL);
 1270         /* M_PREPEND takes care of m_len, m_pkthdr.len for us */
 1271 
 1272         if (m->m_len < sizeof(*evl)) {
 1273                 m = m_pullup(m, sizeof(*evl));
 1274                 if (m == NULL)
 1275                         return (NULL);
 1276         }
 1277 
 1278         /*
 1279          * Transform the Ethernet header into an Ethernet header
 1280          * with 802.1Q encapsulation.
 1281          */
 1282         evl = mtod(m, struct ether_vlan_header *);
 1283         bcopy((char *)evl + ETHER_VLAN_ENCAP_LEN,
 1284             (char *)evl, ETHER_HDR_LEN - ETHER_TYPE_LEN);
 1285         evl->evl_encap_proto = htons(ETHERTYPE_VLAN);
 1286         evl->evl_tag = htons(tag);
 1287         return (m);
 1288 }
 1289 
 1290 static SYSCTL_NODE(_net_link, IFT_L2VLAN, vlan, CTLFLAG_RW, 0,
 1291     "IEEE 802.1Q VLAN");
 1292 static SYSCTL_NODE(_net_link_vlan, PF_LINK, link, CTLFLAG_RW, 0,
 1293     "for consistency");
 1294 
 1295 VNET_DEFINE_STATIC(int, soft_pad);
 1296 #define V_soft_pad      VNET(soft_pad)
 1297 SYSCTL_INT(_net_link_vlan, OID_AUTO, soft_pad, CTLFLAG_RW | CTLFLAG_VNET,
 1298     &VNET_NAME(soft_pad), 0,
 1299     "pad short frames before tagging");
 1300 
 1301 /*
 1302  * For now, make preserving PCP via an mbuf tag optional, as it increases
 1303  * per-packet memory allocations and frees.  In the future, it would be
 1304  * preferable to reuse ether_vtag for this, or similar.
 1305  */
 1306 int vlan_mtag_pcp = 0;
 1307 SYSCTL_INT(_net_link_vlan, OID_AUTO, mtag_pcp, CTLFLAG_RW,
 1308     &vlan_mtag_pcp, 0,
 1309     "Retain VLAN PCP information as packets are passed up the stack");
 1310 
 1311 bool
 1312 ether_8021q_frame(struct mbuf **mp, struct ifnet *ife, struct ifnet *p,
 1313     uint16_t vid, uint8_t pcp)
 1314 {
 1315         struct m_tag *mtag;
 1316         int n;
 1317         uint16_t tag;
 1318         static const char pad[8];       /* just zeros */
 1319 
 1320         /*
 1321          * Pad the frame to the minimum size allowed if told to.
 1322          * This option is in accord with IEEE Std 802.1Q, 2003 Ed.,
 1323          * paragraph C.4.4.3.b.  It can help to work around buggy
 1324          * bridges that violate paragraph C.4.4.3.a from the same
 1325          * document, i.e., fail to pad short frames after untagging.
 1326          * E.g., a tagged frame 66 bytes long (incl. FCS) is OK, but
 1327          * untagging it will produce a 62-byte frame, which is a runt
 1328          * and requires padding.  There are VLAN-enabled network
 1329          * devices that just discard such runts instead or mishandle
 1330          * them somehow.
 1331          */
 1332         if (V_soft_pad && p->if_type == IFT_ETHER) {
 1333                 for (n = ETHERMIN + ETHER_HDR_LEN - (*mp)->m_pkthdr.len;
 1334                      n > 0; n -= sizeof(pad)) {
 1335                         if (!m_append(*mp, min(n, sizeof(pad)), pad))
 1336                                 break;
 1337                 }
 1338                 if (n > 0) {
 1339                         m_freem(*mp);
 1340                         *mp = NULL;
 1341                         if_printf(ife, "cannot pad short frame");
 1342                         return (false);
 1343                 }
 1344         }
 1345 
 1346         /*
 1347          * If underlying interface can do VLAN tag insertion itself,
 1348          * just pass the packet along. However, we need some way to
 1349          * tell the interface where the packet came from so that it
 1350          * knows how to find the VLAN tag to use, so we attach a
 1351          * packet tag that holds it.
 1352          */
 1353         if (vlan_mtag_pcp && (mtag = m_tag_locate(*mp, MTAG_8021Q,
 1354             MTAG_8021Q_PCP_OUT, NULL)) != NULL)
 1355                 tag = EVL_MAKETAG(vid, *(uint8_t *)(mtag + 1), 0);
 1356         else
 1357                 tag = EVL_MAKETAG(vid, pcp, 0);
 1358         if (p->if_capenable & IFCAP_VLAN_HWTAGGING) {
 1359                 (*mp)->m_pkthdr.ether_vtag = tag;
 1360                 (*mp)->m_flags |= M_VLANTAG;
 1361         } else {
 1362                 *mp = ether_vlanencap(*mp, tag);
 1363                 if (*mp == NULL) {
 1364                         if_printf(ife, "unable to prepend 802.1Q header");
 1365                         return (false);
 1366                 }
 1367         }
 1368         return (true);
 1369 }
 1370 
 1371 DECLARE_MODULE(ether, ether_mod, SI_SUB_INIT_IF, SI_ORDER_ANY);
 1372 MODULE_VERSION(ether, 1);

Cache object: 95282c2e236c82ef3ed00aedbb06fc87


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.