sys/netgraph7/ng_vlan.c

   1 /*-
   2  * Copyright (c) 2003 IPNET Internet Communication Company
   3  * 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  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  *
  26  * Author: Ruslan Ermilov <ru@FreeBSD.org>
  27  *
  28  * $FreeBSD: src/sys/netgraph/ng_vlan.c,v 1.5 2007/06/11 15:29:02 imp Exp $
  29  */
  30
  31 #include <sys/param.h>
  32 #include <sys/errno.h>
  33 #include <sys/kernel.h>
  34 #include <sys/malloc.h>
  35 #include <sys/mbuf.h>
  36 #include <sys/queue.h>
  37 #include <sys/socket.h>
  38 #include <sys/systm.h>
  39
  40 #include <net/ethernet.h>
  41 #include <net/if.h>
  42 #include <net/if_vlan_var.h>
  43
  44 #include "ng_message.h"
  45 #include "ng_parse.h"
  46 #include "ng_vlan.h"
  47 #include "netgraph.h"
  48
  49 static ng_constructor_t ng_vlan_constructor;
  50 static ng_rcvmsg_t      ng_vlan_rcvmsg;
  51 static ng_shutdown_t    ng_vlan_shutdown;
  52 static ng_newhook_t     ng_vlan_newhook;
  53 static ng_rcvdata_t     ng_vlan_rcvdata;
  54 static ng_disconnect_t  ng_vlan_disconnect;
  55
  56 /* Parse type for struct ng_vlan_filter. */
  57 static const struct ng_parse_struct_field ng_vlan_filter_fields[] =
  58         NG_VLAN_FILTER_FIELDS;
  59 static const struct ng_parse_type ng_vlan_filter_type = {
  60         &ng_parse_struct_type,
  61         &ng_vlan_filter_fields
  62 };
  63
  64 static int
  65 ng_vlan_getTableLength(const struct ng_parse_type *type,
  66     const u_char *start, const u_char *buf)
  67 {
  68         const struct ng_vlan_table *const table =
  69             (const struct ng_vlan_table *)(buf - sizeof(u_int32_t));
  70
  71         return table->n;
  72 }
  73
  74 /* Parse type for struct ng_vlan_table. */
  75 static const struct ng_parse_array_info ng_vlan_table_array_info = {
  76         &ng_vlan_filter_type,
  77         ng_vlan_getTableLength
  78 };
  79 static const struct ng_parse_type ng_vlan_table_array_type = {
  80         &ng_parse_array_type,
  81         &ng_vlan_table_array_info
  82 };
  83 static const struct ng_parse_struct_field ng_vlan_table_fields[] =
  84         NG_VLAN_TABLE_FIELDS;
  85 static const struct ng_parse_type ng_vlan_table_type = {
  86         &ng_parse_struct_type,
  87         &ng_vlan_table_fields
  88 };
  89
  90 /* List of commands and how to convert arguments to/from ASCII. */
  91 static const struct ng_cmdlist ng_vlan_cmdlist[] = {
  92         {
  93           NGM_VLAN_COOKIE,
  94           NGM_VLAN_ADD_FILTER,
  95           "addfilter",
  96           &ng_vlan_filter_type,
  97           NULL
  98         },
  99         {
 100           NGM_VLAN_COOKIE,
 101           NGM_VLAN_DEL_FILTER,
 102           "delfilter",
 103           &ng_parse_hookbuf_type,
 104           NULL
 105         },
 106         {
 107           NGM_VLAN_COOKIE,
 108           NGM_VLAN_GET_TABLE,
 109           "gettable",
 110           NULL,
 111           &ng_vlan_table_type
 112         },
 113         { 0 }
 114 };
 115
 116 static struct ng_type ng_vlan_typestruct = {
 117         .version =      NG_ABI_VERSION,
 118         .name =         NG_VLAN_NODE_TYPE,
 119         .constructor =  ng_vlan_constructor,
 120         .rcvmsg =       ng_vlan_rcvmsg,
 121         .shutdown =     ng_vlan_shutdown,
 122         .newhook =      ng_vlan_newhook,
 123         .rcvdata =      ng_vlan_rcvdata,
 124         .disconnect =   ng_vlan_disconnect,
 125         .cmdlist =      ng_vlan_cmdlist,
 126 };
 127 NETGRAPH_INIT(vlan, &ng_vlan_typestruct);
 128
 129 struct filter {
 130         LIST_ENTRY(filter) next;
 131         u_int16_t       vlan;
 132         hook_p          hook;
 133 };
 134
 135 #define HASHSIZE        16
 136 #define HASH(id)        ((((id) >> 8) ^ ((id) >> 4) ^ (id)) & 0x0f)
 137 LIST_HEAD(filterhead, filter);
 138
 139 typedef struct {
 140         hook_p          downstream_hook;
 141         hook_p          nomatch_hook;
 142         struct filterhead hashtable[HASHSIZE];
 143         u_int32_t       nent;
 144 } *priv_p;
 145
 146 static struct filter *
 147 ng_vlan_findentry(priv_p priv, u_int16_t vlan)
 148 {
 149         struct filterhead *chain = &priv->hashtable[HASH(vlan)];
 150         struct filter *f;
 151
 152         LIST_FOREACH(f, chain, next)
 153                 if (f->vlan == vlan)
 154                         return (f);
 155         return (NULL);
 156 }
 157
 158 static int
 159 ng_vlan_constructor(node_p node)
 160 {
 161         priv_p priv;
 162         int i;
 163
 164         priv = kmalloc(sizeof(*priv), M_NETGRAPH,
 165                        M_WAITOK | M_NULLOK | M_ZERO);
 166         if (priv == NULL)
 167                 return (ENOMEM);
 168         for (i = 0; i < HASHSIZE; i++)
 169                 LIST_INIT(&priv->hashtable[i]);
 170         NG_NODE_SET_PRIVATE(node, priv);
 171         return (0);
 172 }
 173
 174 static int
 175 ng_vlan_newhook(node_p node, hook_p hook, const char *name)
 176 {
 177         const priv_p priv = NG_NODE_PRIVATE(node);
 178
 179         if (strcmp(name, NG_VLAN_HOOK_DOWNSTREAM) == 0)
 180                 priv->downstream_hook = hook;
 181         else if (strcmp(name, NG_VLAN_HOOK_NOMATCH) == 0)
 182                 priv->nomatch_hook = hook;
 183         else {
 184                 /*
 185                  * Any other hook name is valid and can
 186                  * later be associated with a filter rule.
 187                  */
 188         }
 189         NG_HOOK_SET_PRIVATE(hook, NULL);
 190         return (0);
 191 }
 192
 193 static int
 194 ng_vlan_rcvmsg(node_p node, item_p item, hook_p lasthook)
 195 {
 196         const priv_p priv = NG_NODE_PRIVATE(node);
 197         int error = 0;
 198         struct ng_mesg *msg, *resp = NULL;
 199         struct ng_vlan_filter *vf;
 200         struct filter *f;
 201         hook_p hook;
 202         struct ng_vlan_table *t;
 203         int i;
 204
 205         NGI_GET_MSG(item, msg);
 206         /* Deal with message according to cookie and command. */
 207         switch (msg->header.typecookie) {
 208         case NGM_VLAN_COOKIE:
 209                 switch (msg->header.cmd) {
 210                 case NGM_VLAN_ADD_FILTER:
 211                         /* Check that message is long enough. */
 212                         if (msg->header.arglen != sizeof(*vf)) {
 213                                 error = EINVAL;
 214                                 break;
 215                         }
 216                         vf = (struct ng_vlan_filter *)msg->data;
 217                         /* Sanity check the VLAN ID value. */
 218                         if (vf->vlan & ~EVL_VLID_MASK) {
 219                                 error = EINVAL;
 220                                 break;
 221                         }
 222                         /* Check that a referenced hook exists. */
 223                         hook = ng_findhook(node, vf->hook);
 224                         if (hook == NULL) {
 225                                 error = ENOENT;
 226                                 break;
 227                         }
 228                         /* And is not one of the special hooks. */
 229                         if (hook == priv->downstream_hook ||
 230                             hook == priv->nomatch_hook) {
 231                                 error = EINVAL;
 232                                 break;
 233                         }
 234                         /* And is not already in service. */
 235                         if (NG_HOOK_PRIVATE(hook) != NULL) {
 236                                 error = EEXIST;
 237                                 break;
 238                         }
 239                         /* Check we don't already trap this VLAN. */
 240                         if (ng_vlan_findentry(priv, vf->vlan)) {
 241                                 error = EEXIST;
 242                                 break;
 243                         }
 244                         /* Create filter. */
 245                         f = kmalloc(sizeof(*f), M_NETGRAPH,
 246                                     M_WAITOK | M_NULLOK | M_ZERO);
 247                         if (f == NULL) {
 248                                 error = ENOMEM;
 249                                 break;
 250                         }
 251                         /* Link filter and hook together. */
 252                         f->hook = hook;
 253                         f->vlan = vf->vlan;
 254                         NG_HOOK_SET_PRIVATE(hook, f);
 255                         /* Register filter in a hash table. */
 256                         LIST_INSERT_HEAD(
 257                             &priv->hashtable[HASH(f->vlan)], f, next);
 258                         priv->nent++;
 259                         break;
 260                 case NGM_VLAN_DEL_FILTER:
 261                         /* Check that message is long enough. */
 262                         if (msg->header.arglen != NG_HOOKSIZ) {
 263                                 error = EINVAL;
 264                                 break;
 265                         }
 266                         /* Check that hook exists and is active. */
 267                         hook = ng_findhook(node, (char *)msg->data);
 268                         if (hook == NULL ||
 269                             (f = NG_HOOK_PRIVATE(hook)) == NULL) {
 270                                 error = ENOENT;
 271                                 break;
 272                         }
 273                         /* Purge a rule that refers to this hook. */
 274                         NG_HOOK_SET_PRIVATE(hook, NULL);
 275                         LIST_REMOVE(f, next);
 276                         priv->nent--;
 277                         kfree(f, M_NETGRAPH);
 278                         break;
 279                 case NGM_VLAN_GET_TABLE:
 280                         NG_MKRESPONSE(resp, msg, sizeof(*t) +
 281                             priv->nent * sizeof(*t->filter), M_WAITOK | M_NULLOK);
 282                         if (resp == NULL) {
 283                                 error = ENOMEM;
 284                                 break;
 285                         }
 286                         t = (struct ng_vlan_table *)resp->data;
 287                         t->n = priv->nent;
 288                         vf = &t->filter[0];
 289                         for (i = 0; i < HASHSIZE; i++) {
 290                                 LIST_FOREACH(f, &priv->hashtable[i], next) {
 291                                         vf->vlan = f->vlan;
 292                                         strncpy(vf->hook, NG_HOOK_NAME(f->hook),
 293                                             NG_HOOKSIZ);
 294                                         vf++;
 295                                 }
 296                         }
 297                         break;
 298                 default:                /* Unknown command. */
 299                         error = EINVAL;
 300                         break;
 301                 }
 302                 break;
 303         case NGM_FLOW_COOKIE:
 304             {
 305                 struct ng_mesg *copy;
 306                 struct filterhead *chain;
 307                 struct filter *f;
 308
 309                 /*
 310                  * Flow control messages should come only
 311                  * from downstream.
 312                  */
 313
 314                 if (lasthook == NULL)
 315                         break;
 316                 if (lasthook != priv->downstream_hook)
 317                         break;
 318
 319                 /* Broadcast the event to all uplinks. */
 320                 for (i = 0, chain = priv->hashtable; i < HASHSIZE;
 321                     i++, chain++) {
 322                         LIST_FOREACH(f, chain, next) {
 323                                 NG_COPYMESSAGE(copy, msg, M_WAITOK | M_NULLOK);
 324                                 if (copy == NULL)
 325                                         continue;
 326                                 NG_SEND_MSG_HOOK(error, node, copy, f->hook, 0);
 327                         }
 328                 }
 329
 330                 break;
 331             }
 332         default:                        /* Unknown type cookie. */
 333                 error = EINVAL;
 334                 break;
 335         }
 336         NG_RESPOND_MSG(error, node, item, resp);
 337         NG_FREE_MSG(msg);
 338         return (error);
 339 }
 340
 341 static int
 342 ng_vlan_rcvdata(hook_p hook, item_p item)
 343 {
 344         const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 345         struct ether_header *eh;
 346         struct ether_vlan_header *evl = NULL;
 347         int error;
 348         u_int16_t vlan;
 349         struct mbuf *m;
 350         struct filter *f;
 351
 352         /* Make sure we have an entire header. */
 353         NGI_GET_M(item, m);
 354         if (m->m_len < sizeof(*eh) &&
 355             (m = m_pullup(m, sizeof(*eh))) == NULL) {
 356                 NG_FREE_ITEM(item);
 357                 return (EINVAL);
 358         }
 359         eh = mtod(m, struct ether_header *);
 360         if (hook == priv->downstream_hook) {
 361                 /*
 362                  * If from downstream, select between a match hook
 363                  * or the nomatch hook.
 364                  */
 365                 if (m->m_flags & M_VLANTAG ||
 366                     eh->ether_type == htons(ETHERTYPE_VLAN)) {
 367                         if (m->m_flags & M_VLANTAG) {
 368                                 /*
 369                                  * Packet is tagged, m contains a normal
 370                                  * Ethernet frame; tag is stored out-of-band.
 371                                  */
 372                                 vlan = EVL_VLANOFTAG(m->m_pkthdr.ether_vtag);
 373                         } else {
 374                                 if (m->m_len < sizeof(*evl) &&
 375                                     (m = m_pullup(m, sizeof(*evl))) == NULL) {
 376                                         NG_FREE_ITEM(item);
 377                                         return (EINVAL);
 378                                 }
 379                                 evl = mtod(m, struct ether_vlan_header *);
 380                                 vlan = EVL_VLANOFTAG(ntohs(evl->evl_tag));
 381                         }
 382                         if ((f = ng_vlan_findentry(priv, vlan)) != NULL) {
 383                                 if (m->m_flags & M_VLANTAG) {
 384                                         m->m_pkthdr.ether_vtag = 0;
 385                                         m->m_flags &= ~M_VLANTAG;
 386                                 } else {
 387                                         evl->evl_encap_proto = evl->evl_proto;
 388                                         bcopy(mtod(m, caddr_t),
 389                                             mtod(m, caddr_t) +
 390                                             ETHER_VLAN_ENCAP_LEN,
 391                                             ETHER_HDR_LEN);
 392                                         m_adj(m, ETHER_VLAN_ENCAP_LEN);
 393                                 }
 394                         }
 395                 } else
 396                         f = NULL;
 397                 if (f != NULL)
 398                         NG_FWD_NEW_DATA(error, item, f->hook, m);
 399                 else
 400                         NG_FWD_NEW_DATA(error, item, priv->nomatch_hook, m);
 401         } else {
 402                 /*
 403                  * It is heading towards the downstream.
 404                  * If from nomatch, pass it unmodified.
 405                  * Otherwise, do the VLAN encapsulation.
 406                  */
 407                 if (hook != priv->nomatch_hook) {
 408                         if ((f = NG_HOOK_PRIVATE(hook)) == NULL) {
 409                                 NG_FREE_ITEM(item);
 410                                 NG_FREE_M(m);
 411                                 return (EOPNOTSUPP);
 412                         }
 413                         M_PREPEND(m, ETHER_VLAN_ENCAP_LEN, MB_DONTWAIT);
 414                         /* M_PREPEND takes care of m_len and m_pkthdr.len. */
 415                         if (m == NULL || (m->m_len < sizeof(*evl) &&
 416                             (m = m_pullup(m, sizeof(*evl))) == NULL)) {
 417                                 NG_FREE_ITEM(item);
 418                                 return (ENOMEM);
 419                         }
 420                         /*
 421                          * Transform the Ethernet header into an Ethernet header
 422                          * with 802.1Q encapsulation.
 423                          */
 424                         bcopy(mtod(m, char *) + ETHER_VLAN_ENCAP_LEN,
 425                             mtod(m, char *), ETHER_HDR_LEN);
 426                         evl = mtod(m, struct ether_vlan_header *);
 427                         evl->evl_proto = evl->evl_encap_proto;
 428                         evl->evl_encap_proto = htons(ETHERTYPE_VLAN);
 429                         evl->evl_tag = htons(f->vlan);
 430                 }
 431                 NG_FWD_NEW_DATA(error, item, priv->downstream_hook, m);
 432         }
 433         return (error);
 434 }
 435
 436 static int
 437 ng_vlan_shutdown(node_p node)
 438 {
 439         const priv_p priv = NG_NODE_PRIVATE(node);
 440
 441         NG_NODE_SET_PRIVATE(node, NULL);
 442         NG_NODE_UNREF(node);
 443         kfree(priv, M_NETGRAPH);
 444         return (0);
 445 }
 446
 447 static int
 448 ng_vlan_disconnect(hook_p hook)
 449 {
 450         const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 451         struct filter *f;
 452
 453         if (hook == priv->downstream_hook)
 454                 priv->downstream_hook = NULL;
 455         else if (hook == priv->nomatch_hook)
 456                 priv->nomatch_hook = NULL;
 457         else {
 458                 /* Purge a rule that refers to this hook. */
 459                 if ((f = NG_HOOK_PRIVATE(hook)) != NULL) {
 460                         LIST_REMOVE(f, next);
 461                         priv->nent--;
 462                         kfree(f, M_NETGRAPH);
 463                 }
 464         }
 465         NG_HOOK_SET_PRIVATE(hook, NULL);
 466         if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) &&
 467             (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
 468                 ng_rmnode_self(NG_HOOK_NODE(hook));
 469         return (0);
 470 }