sys/netgraph/ng_vlan.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2003 IPNET Internet Communication Company
   5  * Copyright (c) 2011 - 2012 Rozhuk Ivan <rozhuk.im@gmail.com>
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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  * Author: Ruslan Ermilov <ru@FreeBSD.org>
  30  *
  31  * $FreeBSD$
  32  */
  33
  34 #include <sys/param.h>
  35 #include <sys/errno.h>
  36 #include <sys/kernel.h>
  37 #include <sys/malloc.h>
  38 #include <sys/mbuf.h>
  39 #include <sys/queue.h>
  40 #include <sys/socket.h>
  41 #include <sys/systm.h>
  42
  43 #include <net/ethernet.h>
  44 #include <net/if.h>
  45 #include <net/if_vlan_var.h>
  46
  47 #include <netgraph/ng_message.h>
  48 #include <netgraph/ng_parse.h>
  49 #include <netgraph/ng_vlan.h>
  50 #include <netgraph/netgraph.h>
  51
  52 struct ng_vlan_private {
  53         hook_p          downstream_hook;
  54         hook_p          nomatch_hook;
  55         uint32_t        decap_enable;
  56         uint32_t        encap_enable;
  57         uint16_t        encap_proto;
  58         hook_p          vlan_hook[(EVL_VLID_MASK + 1)];
  59 };
  60 typedef struct ng_vlan_private *priv_p;
  61
  62 #define ETHER_VLAN_HDR_LEN (ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN)
  63 #define VLAN_TAG_MASK   0xFFFF
  64 #define HOOK_VLAN_TAG_SET_MASK ((uintptr_t)((~0) & ~(VLAN_TAG_MASK)))
  65 #define IS_HOOK_VLAN_SET(hdata) \
  66             ((((uintptr_t)hdata) & HOOK_VLAN_TAG_SET_MASK) == HOOK_VLAN_TAG_SET_MASK)
  67
  68 static ng_constructor_t ng_vlan_constructor;
  69 static ng_rcvmsg_t      ng_vlan_rcvmsg;
  70 static ng_shutdown_t    ng_vlan_shutdown;
  71 static ng_newhook_t     ng_vlan_newhook;
  72 static ng_rcvdata_t     ng_vlan_rcvdata;
  73 static ng_disconnect_t  ng_vlan_disconnect;
  74
  75 /* Parse type for struct ng_vlan_filter. */
  76 static const struct ng_parse_struct_field ng_vlan_filter_fields[] =
  77         NG_VLAN_FILTER_FIELDS;
  78 static const struct ng_parse_type ng_vlan_filter_type = {
  79         &ng_parse_struct_type,
  80         &ng_vlan_filter_fields
  81 };
  82
  83 static int
  84 ng_vlan_getTableLength(const struct ng_parse_type *type,
  85     const u_char *start, const u_char *buf)
  86 {
  87         const struct ng_vlan_table *const table =
  88             (const struct ng_vlan_table *)(buf - sizeof(u_int32_t));
  89
  90         return table->n;
  91 }
  92
  93 /* Parse type for struct ng_vlan_table. */
  94 static const struct ng_parse_array_info ng_vlan_table_array_info = {
  95         &ng_vlan_filter_type,
  96         ng_vlan_getTableLength
  97 };
  98 static const struct ng_parse_type ng_vlan_table_array_type = {
  99         &ng_parse_array_type,
 100         &ng_vlan_table_array_info
 101 };
 102 static const struct ng_parse_struct_field ng_vlan_table_fields[] =
 103         NG_VLAN_TABLE_FIELDS;
 104 static const struct ng_parse_type ng_vlan_table_type = {
 105         &ng_parse_struct_type,
 106         &ng_vlan_table_fields
 107 };
 108
 109 /* List of commands and how to convert arguments to/from ASCII. */
 110 static const struct ng_cmdlist ng_vlan_cmdlist[] = {
 111         {
 112           NGM_VLAN_COOKIE,
 113           NGM_VLAN_ADD_FILTER,
 114           "addfilter",
 115           &ng_vlan_filter_type,
 116           NULL
 117         },
 118         {
 119           NGM_VLAN_COOKIE,
 120           NGM_VLAN_DEL_FILTER,
 121           "delfilter",
 122           &ng_parse_hookbuf_type,
 123           NULL
 124         },
 125         {
 126           NGM_VLAN_COOKIE,
 127           NGM_VLAN_GET_TABLE,
 128           "gettable",
 129           NULL,
 130           &ng_vlan_table_type
 131         },
 132         {
 133           NGM_VLAN_COOKIE,
 134           NGM_VLAN_DEL_VID_FLT,
 135           "delvidflt",
 136           &ng_parse_uint16_type,
 137           NULL
 138         },
 139         {
 140           NGM_VLAN_COOKIE,
 141           NGM_VLAN_GET_DECAP,
 142           "getdecap",
 143           NULL,
 144           &ng_parse_hint32_type
 145         },
 146         {
 147           NGM_VLAN_COOKIE,
 148           NGM_VLAN_SET_DECAP,
 149           "setdecap",
 150           &ng_parse_hint32_type,
 151           NULL
 152         },
 153         {
 154           NGM_VLAN_COOKIE,
 155           NGM_VLAN_GET_ENCAP,
 156           "getencap",
 157           NULL,
 158           &ng_parse_hint32_type
 159         },
 160         {
 161           NGM_VLAN_COOKIE,
 162           NGM_VLAN_SET_ENCAP,
 163           "setencap",
 164           &ng_parse_hint32_type,
 165           NULL
 166         },
 167         {
 168           NGM_VLAN_COOKIE,
 169           NGM_VLAN_GET_ENCAP_PROTO,
 170           "getencapproto",
 171           NULL,
 172           &ng_parse_hint16_type
 173         },
 174         {
 175           NGM_VLAN_COOKIE,
 176           NGM_VLAN_SET_ENCAP_PROTO,
 177           "setencapproto",
 178           &ng_parse_hint16_type,
 179           NULL
 180         },
 181         { 0 }
 182 };
 183
 184 static struct ng_type ng_vlan_typestruct = {
 185         .version =      NG_ABI_VERSION,
 186         .name =         NG_VLAN_NODE_TYPE,
 187         .constructor =  ng_vlan_constructor,
 188         .rcvmsg =       ng_vlan_rcvmsg,
 189         .shutdown =     ng_vlan_shutdown,
 190         .newhook =      ng_vlan_newhook,
 191         .rcvdata =      ng_vlan_rcvdata,
 192         .disconnect =   ng_vlan_disconnect,
 193         .cmdlist =      ng_vlan_cmdlist,
 194 };
 195 NETGRAPH_INIT(vlan, &ng_vlan_typestruct);
 196
 197
 198 /*
 199  * Helper functions.
 200  */
 201
 202 static __inline int
 203 m_chk(struct mbuf **mp, int len)
 204 {
 205
 206         if ((*mp)->m_pkthdr.len < len) {
 207                 m_freem((*mp));
 208                 (*mp) = NULL;
 209                 return (EINVAL);
 210         }
 211         if ((*mp)->m_len < len && ((*mp) = m_pullup((*mp), len)) == NULL)
 212                 return (ENOBUFS);
 213
 214         return (0);
 215 }
 216
 217
 218 /*
 219  * Netgraph node functions.
 220  */
 221
 222 static int
 223 ng_vlan_constructor(node_p node)
 224 {
 225         priv_p priv;
 226
 227         priv = malloc(sizeof(*priv), M_NETGRAPH, M_WAITOK | M_ZERO);
 228         priv->decap_enable = 0;
 229         priv->encap_enable = VLAN_ENCAP_FROM_FILTER;
 230         priv->encap_proto = htons(ETHERTYPE_VLAN);
 231         NG_NODE_SET_PRIVATE(node, priv);
 232         return (0);
 233 }
 234
 235 static int
 236 ng_vlan_newhook(node_p node, hook_p hook, const char *name)
 237 {
 238         const priv_p priv = NG_NODE_PRIVATE(node);
 239
 240         if (strcmp(name, NG_VLAN_HOOK_DOWNSTREAM) == 0)
 241                 priv->downstream_hook = hook;
 242         else if (strcmp(name, NG_VLAN_HOOK_NOMATCH) == 0)
 243                 priv->nomatch_hook = hook;
 244         else {
 245                 /*
 246                  * Any other hook name is valid and can
 247                  * later be associated with a filter rule.
 248                  */
 249         }
 250         NG_HOOK_SET_PRIVATE(hook, NULL);
 251         return (0);
 252 }
 253
 254 static int
 255 ng_vlan_rcvmsg(node_p node, item_p item, hook_p lasthook)
 256 {
 257         const priv_p priv = NG_NODE_PRIVATE(node);
 258         struct ng_mesg *msg, *resp = NULL;
 259         struct ng_vlan_filter *vf;
 260         hook_p hook;
 261         struct ng_vlan_table *t;
 262         uintptr_t hook_data;
 263         int i, vlan_count;
 264         uint16_t vid;
 265         int error = 0;
 266
 267         NGI_GET_MSG(item, msg);
 268         /* Deal with message according to cookie and command. */
 269         switch (msg->header.typecookie) {
 270         case NGM_VLAN_COOKIE:
 271                 switch (msg->header.cmd) {
 272                 case NGM_VLAN_ADD_FILTER:
 273                         /* Check that message is long enough. */
 274                         if (msg->header.arglen != sizeof(*vf)) {
 275                                 error = EINVAL;
 276                                 break;
 277                         }
 278                         vf = (struct ng_vlan_filter *)msg->data;
 279                         /* Sanity check the VLAN ID value. */
 280 #ifdef  NG_VLAN_USE_OLD_VLAN_NAME
 281                         if (vf->vid == 0 && vf->vid != vf->vlan) {
 282                                 vf->vid = vf->vlan;
 283                         } else if (vf->vid != 0 && vf->vlan != 0 &&
 284                             vf->vid != vf->vlan) {
 285                                 error = EINVAL;
 286                                 break;
 287                         }
 288 #endif
 289                         if (vf->vid & ~EVL_VLID_MASK ||
 290                             vf->pcp & ~7 ||
 291                             vf->cfi & ~1) {
 292                                 error = EINVAL;
 293                                 break;
 294                         }
 295                         /* Check that a referenced hook exists. */
 296                         hook = ng_findhook(node, vf->hook_name);
 297                         if (hook == NULL) {
 298                                 error = ENOENT;
 299                                 break;
 300                         }
 301                         /* And is not one of the special hooks. */
 302                         if (hook == priv->downstream_hook ||
 303                             hook == priv->nomatch_hook) {
 304                                 error = EINVAL;
 305                                 break;
 306                         }
 307                         /* And is not already in service. */
 308                         if (IS_HOOK_VLAN_SET(NG_HOOK_PRIVATE(hook))) {
 309                                 error = EEXIST;
 310                                 break;
 311                         }
 312                         /* Check we don't already trap this VLAN. */
 313                         if (priv->vlan_hook[vf->vid] != NULL) {
 314                                 error = EEXIST;
 315                                 break;
 316                         }
 317                         /* Link vlan and hook together. */
 318                         NG_HOOK_SET_PRIVATE(hook,
 319                             (void *)(HOOK_VLAN_TAG_SET_MASK |
 320                             EVL_MAKETAG(vf->vid, vf->pcp, vf->cfi)));
 321                         priv->vlan_hook[vf->vid] = hook;
 322                         break;
 323                 case NGM_VLAN_DEL_FILTER:
 324                         /* Check that message is long enough. */
 325                         if (msg->header.arglen != NG_HOOKSIZ) {
 326                                 error = EINVAL;
 327                                 break;
 328                         }
 329                         /* Check that hook exists and is active. */
 330                         hook = ng_findhook(node, (char *)msg->data);
 331                         if (hook == NULL) {
 332                                 error = ENOENT;
 333                                 break;
 334                         }
 335                         hook_data = (uintptr_t)NG_HOOK_PRIVATE(hook);
 336                         if (IS_HOOK_VLAN_SET(hook_data) == 0) {
 337                                 error = ENOENT;
 338                                 break;
 339                         }
 340
 341                         KASSERT(priv->vlan_hook[EVL_VLANOFTAG(hook_data)] == hook,
 342                             ("%s: NGM_VLAN_DEL_FILTER: Invalid VID for Hook = %s\n",
 343                             __func__, (char *)msg->data));
 344
 345                         /* Purge a rule that refers to this hook. */
 346                         priv->vlan_hook[EVL_VLANOFTAG(hook_data)] = NULL;
 347                         NG_HOOK_SET_PRIVATE(hook, NULL);
 348                         break;
 349                 case NGM_VLAN_DEL_VID_FLT:
 350                         /* Check that message is long enough. */
 351                         if (msg->header.arglen != sizeof(uint16_t)) {
 352                                 error = EINVAL;
 353                                 break;
 354                         }
 355                         vid = (*((uint16_t *)msg->data));
 356                         /* Sanity check the VLAN ID value. */
 357                         if (vid & ~EVL_VLID_MASK) {
 358                                 error = EINVAL;
 359                                 break;
 360                         }
 361                         /* Check that hook exists and is active. */
 362                         hook = priv->vlan_hook[vid];
 363                         if (hook == NULL) {
 364                                 error = ENOENT;
 365                                 break;
 366                         }
 367                         hook_data = (uintptr_t)NG_HOOK_PRIVATE(hook);
 368                         if (IS_HOOK_VLAN_SET(hook_data) == 0) {
 369                                 error = ENOENT;
 370                                 break;
 371                         }
 372
 373                         KASSERT(EVL_VLANOFTAG(hook_data) == vid,
 374                             ("%s: NGM_VLAN_DEL_VID_FLT:"
 375                             " Invalid VID Hook = %us, must be: %us\n",
 376                             __func__, (uint16_t )EVL_VLANOFTAG(hook_data),
 377                             vid));
 378
 379                         /* Purge a rule that refers to this hook. */
 380                         priv->vlan_hook[vid] = NULL;
 381                         NG_HOOK_SET_PRIVATE(hook, NULL);
 382                         break;
 383                 case NGM_VLAN_GET_TABLE:
 384                         /* Calculate vlans. */
 385                         vlan_count = 0;
 386                         for (i = 0; i < (EVL_VLID_MASK + 1); i ++) {
 387                                 if (priv->vlan_hook[i] != NULL &&
 388                                     NG_HOOK_IS_VALID(priv->vlan_hook[i]))
 389                                         vlan_count ++;
 390                         }
 391
 392                         /* Allocate memory for response. */
 393                         NG_MKRESPONSE(resp, msg, sizeof(*t) +
 394                             vlan_count * sizeof(*t->filter), M_NOWAIT);
 395                         if (resp == NULL) {
 396                                 error = ENOMEM;
 397                                 break;
 398                         }
 399
 400                         /* Pack data to response. */
 401                         t = (struct ng_vlan_table *)resp->data;
 402                         t->n = 0;
 403                         vf = &t->filter[0];
 404                         for (i = 0; i < (EVL_VLID_MASK + 1); i ++) {
 405                                 hook = priv->vlan_hook[i];
 406                                 if (hook == NULL || NG_HOOK_NOT_VALID(hook))
 407                                         continue;
 408                                 hook_data = (uintptr_t)NG_HOOK_PRIVATE(hook);
 409                                 if (IS_HOOK_VLAN_SET(hook_data) == 0)
 410                                         continue;
 411
 412                                 KASSERT(EVL_VLANOFTAG(hook_data) == i,
 413                                     ("%s: NGM_VLAN_GET_TABLE:"
 414                                     " hook %s VID = %us, must be: %i\n",
 415                                     __func__, NG_HOOK_NAME(hook),
 416                                     (uint16_t)EVL_VLANOFTAG(hook_data), i));
 417
 418 #ifdef  NG_VLAN_USE_OLD_VLAN_NAME
 419                                 vf->vlan = i;
 420 #endif
 421                                 vf->vid = i;
 422                                 vf->pcp = EVL_PRIOFTAG(hook_data);
 423                                 vf->cfi = EVL_CFIOFTAG(hook_data);
 424                                 strncpy(vf->hook_name,
 425                                     NG_HOOK_NAME(hook), NG_HOOKSIZ);
 426                                 vf ++;
 427                                 t->n ++;
 428                         }
 429                         break;
 430                 case NGM_VLAN_GET_DECAP:
 431                         NG_MKRESPONSE(resp, msg, sizeof(uint32_t), M_NOWAIT);
 432                         if (resp == NULL) {
 433                                 error = ENOMEM;
 434                                 break;
 435                         }
 436                         (*((uint32_t *)resp->data)) = priv->decap_enable;
 437                         break;
 438                 case NGM_VLAN_SET_DECAP:
 439                         if (msg->header.arglen != sizeof(uint32_t)) {
 440                                 error = EINVAL;
 441                                 break;
 442                         }
 443                         priv->decap_enable = (*((uint32_t *)msg->data));
 444                         break;
 445                 case NGM_VLAN_GET_ENCAP:
 446                         NG_MKRESPONSE(resp, msg, sizeof(uint32_t), M_NOWAIT);
 447                         if (resp == NULL) {
 448                                 error = ENOMEM;
 449                                 break;
 450                         }
 451                         (*((uint32_t *)resp->data)) = priv->encap_enable;
 452                         break;
 453                 case NGM_VLAN_SET_ENCAP:
 454                         if (msg->header.arglen != sizeof(uint32_t)) {
 455                                 error = EINVAL;
 456                                 break;
 457                         }
 458                         priv->encap_enable = (*((uint32_t *)msg->data));
 459                         break;
 460                 case NGM_VLAN_GET_ENCAP_PROTO:
 461                         NG_MKRESPONSE(resp, msg, sizeof(uint16_t), M_NOWAIT);
 462                         if (resp == NULL) {
 463                                 error = ENOMEM;
 464                                 break;
 465                         }
 466                         (*((uint16_t *)resp->data)) = ntohs(priv->encap_proto);
 467                         break;
 468                 case NGM_VLAN_SET_ENCAP_PROTO:
 469                         if (msg->header.arglen != sizeof(uint16_t)) {
 470                                 error = EINVAL;
 471                                 break;
 472                         }
 473                         priv->encap_proto = htons((*((uint16_t *)msg->data)));
 474                         break;
 475                 default: /* Unknown command. */
 476                         error = EINVAL;
 477                         break;
 478                 }
 479                 break;
 480         case NGM_FLOW_COOKIE:
 481             {
 482                 struct ng_mesg *copy;
 483
 484                 /*
 485                  * Flow control messages should come only
 486                  * from downstream.
 487                  */
 488
 489                 if (lasthook == NULL)
 490                         break;
 491                 if (lasthook != priv->downstream_hook)
 492                         break;
 493                 /* Broadcast the event to all uplinks. */
 494                 for (i = 0; i < (EVL_VLID_MASK + 1); i ++) {
 495                         if (priv->vlan_hook[i] == NULL)
 496                                 continue;
 497
 498                         NG_COPYMESSAGE(copy, msg, M_NOWAIT);
 499                         if (copy == NULL)
 500                                 continue;
 501                         NG_SEND_MSG_HOOK(error, node, copy,
 502                             priv->vlan_hook[i], 0);
 503                 }
 504                 break;
 505             }
 506         default: /* Unknown type cookie. */
 507                 error = EINVAL;
 508                 break;
 509         }
 510         NG_RESPOND_MSG(error, node, item, resp);
 511         NG_FREE_MSG(msg);
 512         return (error);
 513 }
 514
 515 static int
 516 ng_vlan_rcvdata(hook_p hook, item_p item)
 517 {
 518         const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 519         struct ether_header *eh;
 520         struct ether_vlan_header *evl;
 521         int error;
 522         uintptr_t hook_data;
 523         uint16_t vid, eth_vtag;
 524         struct mbuf *m;
 525         hook_p dst_hook;
 526
 527
 528         NGI_GET_M(item, m);
 529
 530         /* Make sure we have an entire header. */
 531         error = m_chk(&m, ETHER_HDR_LEN);
 532         if (error != 0)
 533                 goto mchk_err;
 534
 535         eh = mtod(m, struct ether_header *);
 536         if (hook == priv->downstream_hook) {
 537                 /*
 538                  * If from downstream, select between a match hook
 539                  * or the nomatch hook.
 540                  */
 541
 542                 dst_hook = priv->nomatch_hook;
 543
 544                 /* Skip packets without tag. */
 545                 if ((m->m_flags & M_VLANTAG) == 0 &&
 546                     eh->ether_type != priv->encap_proto) {
 547                         if (dst_hook == NULL)
 548                                 goto net_down;
 549                         goto send_packet;
 550                 }
 551
 552                 /* Process packets with tag. */
 553                 if (m->m_flags & M_VLANTAG) {
 554                         /*
 555                          * Packet is tagged, m contains a normal
 556                          * Ethernet frame; tag is stored out-of-band.
 557                          */
 558                         evl = NULL;
 559                         vid = EVL_VLANOFTAG(m->m_pkthdr.ether_vtag);
 560                 } else { /* eh->ether_type == priv->encap_proto */
 561                         error = m_chk(&m, ETHER_VLAN_HDR_LEN);
 562                         if (error != 0)
 563                                 goto mchk_err;
 564                         evl = mtod(m, struct ether_vlan_header *);
 565                         vid = EVL_VLANOFTAG(ntohs(evl->evl_tag));
 566                 }
 567
 568                 if (priv->vlan_hook[vid] != NULL) {
 569                         /*
 570                          * VLAN filter: always remove vlan tags and
 571                          * decapsulate packet.
 572                          */
 573                         dst_hook = priv->vlan_hook[vid];
 574                         if (evl == NULL) { /* m->m_flags & M_VLANTAG */
 575                                 m->m_pkthdr.ether_vtag = 0;
 576                                 m->m_flags &= ~M_VLANTAG;
 577                                 goto send_packet;
 578                         }
 579                 } else { /* nomatch_hook */
 580                         if (dst_hook == NULL)
 581                                 goto net_down;
 582                         if (evl == NULL || priv->decap_enable == 0)
 583                                 goto send_packet;
 584                         /* Save tag out-of-band. */
 585                         m->m_pkthdr.ether_vtag = ntohs(evl->evl_tag);
 586                         m->m_flags |= M_VLANTAG;
 587                 }
 588
 589                 /*
 590                  * Decapsulate:
 591                  * TPID = ether type encap
 592                  * Move DstMAC and SrcMAC to ETHER_TYPE.
 593                  * Before:
 594                  *  [dmac] [smac] [TPID] [PCP/CFI/VID] [ether_type] [payload]
 595                  *  |-----------| >>>>>>>>>>>>>>>>>>>> |--------------------|
 596                  * After:
 597                  *  [free space ] [dmac] [smac] [ether_type] [payload]
 598                  *                |-----------| |--------------------|
 599                  */
 600                 bcopy((char *)evl, ((char *)evl + ETHER_VLAN_ENCAP_LEN),
 601                     (ETHER_ADDR_LEN * 2));
 602                 m_adj(m, ETHER_VLAN_ENCAP_LEN);
 603         } else {
 604                 /*
 605                  * It is heading towards the downstream.
 606                  * If from nomatch, pass it unmodified.
 607                  * Otherwise, do the VLAN encapsulation.
 608                  */
 609                 dst_hook = priv->downstream_hook;
 610                 if (dst_hook == NULL)
 611                         goto net_down;
 612                 if (hook != priv->nomatch_hook) {/* Filter hook. */
 613                         hook_data = (uintptr_t)NG_HOOK_PRIVATE(hook);
 614                         if (IS_HOOK_VLAN_SET(hook_data) == 0) {
 615                                 /*
 616                                  * Packet from hook not in filter
 617                                  * call addfilter for this hook to fix.
 618                                  */
 619                                 error = EOPNOTSUPP;
 620                                 goto drop;
 621                         }
 622                         eth_vtag = (hook_data & VLAN_TAG_MASK);
 623                         if ((priv->encap_enable & VLAN_ENCAP_FROM_FILTER) == 0) {
 624                                 /* Just set packet header tag and send. */
 625                                 m->m_flags |= M_VLANTAG;
 626                                 m->m_pkthdr.ether_vtag = eth_vtag;
 627                                 goto send_packet;
 628                         }
 629                 } else { /* nomatch_hook */
 630                         if ((priv->encap_enable & VLAN_ENCAP_FROM_NOMATCH) == 0 ||
 631                             (m->m_flags & M_VLANTAG) == 0)
 632                                 goto send_packet;
 633                         /* Encapsulate tagged packet. */
 634                         eth_vtag = m->m_pkthdr.ether_vtag;
 635                         m->m_pkthdr.ether_vtag = 0;
 636                         m->m_flags &= ~M_VLANTAG;
 637                 }
 638
 639                 /*
 640                  * Transform the Ethernet header into an Ethernet header
 641                  * with 802.1Q encapsulation.
 642                  * Mod of: ether_vlanencap.
 643                  *
 644                  * TPID = ether type encap
 645                  * Move DstMAC and SrcMAC from ETHER_TYPE.
 646                  * Before:
 647                  *  [free space ] [dmac] [smac] [ether_type] [payload]
 648                  *  <<<<<<<<<<<<< |-----------| |--------------------|
 649                  * After:
 650                  *  [dmac] [smac] [TPID] [PCP/CFI/VID] [ether_type] [payload]
 651                  *  |-----------| |-- inserted tag --| |--------------------|
 652                  */
 653                 M_PREPEND(m, ETHER_VLAN_ENCAP_LEN, M_NOWAIT);
 654                 if (m == NULL)
 655                         error = ENOMEM;
 656                 else
 657                         error = m_chk(&m, ETHER_VLAN_HDR_LEN);
 658                 if (error != 0)
 659                         goto mchk_err;
 660
 661                 evl = mtod(m, struct ether_vlan_header *);
 662                 bcopy(((char *)evl + ETHER_VLAN_ENCAP_LEN),
 663                     (char *)evl, (ETHER_ADDR_LEN * 2));
 664                 evl->evl_encap_proto = priv->encap_proto;
 665                 evl->evl_tag = htons(eth_vtag);
 666         }
 667
 668 send_packet:
 669         NG_FWD_NEW_DATA(error, item, dst_hook, m);
 670         return (error);
 671 net_down:
 672         error = ENETDOWN;
 673 drop:
 674         m_freem(m);
 675 mchk_err:
 676         NG_FREE_ITEM(item);
 677         return (error);
 678 }
 679
 680 static int
 681 ng_vlan_shutdown(node_p node)
 682 {
 683         const priv_p priv = NG_NODE_PRIVATE(node);
 684
 685         NG_NODE_SET_PRIVATE(node, NULL);
 686         NG_NODE_UNREF(node);
 687         free(priv, M_NETGRAPH);
 688         return (0);
 689 }
 690
 691 static int
 692 ng_vlan_disconnect(hook_p hook)
 693 {
 694         const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 695         uintptr_t hook_data;
 696
 697         if (hook == priv->downstream_hook)
 698                 priv->downstream_hook = NULL;
 699         else if (hook == priv->nomatch_hook)
 700                 priv->nomatch_hook = NULL;
 701         else {
 702                 /* Purge a rule that refers to this hook. */
 703                 hook_data = (uintptr_t)NG_HOOK_PRIVATE(hook);
 704                 if (IS_HOOK_VLAN_SET(hook_data))
 705                         priv->vlan_hook[EVL_VLANOFTAG(hook_data)] = NULL;
 706         }
 707         NG_HOOK_SET_PRIVATE(hook, NULL);
 708         if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) &&
 709             (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
 710                 ng_rmnode_self(NG_HOOK_NODE(hook));
 711         return (0);
 712 }