sys/netgraph/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  * $FreeBSD$
  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 <netgraph/ng_message.h>
  45 #include <netgraph/ng_parse.h>
  46 #include <netgraph/ng_vlan.h>
  47 #include <netgraph/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 = malloc(sizeof(*priv), M_NETGRAPH, M_WAITOK | M_ZERO);
 165         for (i = 0; i < HASHSIZE; i++)
 166                 LIST_INIT(&priv->hashtable[i]);
 167         NG_NODE_SET_PRIVATE(node, priv);
 168         return (0);
 169 }
 170
 171 static int
 172 ng_vlan_newhook(node_p node, hook_p hook, const char *name)
 173 {
 174         const priv_p priv = NG_NODE_PRIVATE(node);
 175
 176         if (strcmp(name, NG_VLAN_HOOK_DOWNSTREAM) == 0)
 177                 priv->downstream_hook = hook;
 178         else if (strcmp(name, NG_VLAN_HOOK_NOMATCH) == 0)
 179                 priv->nomatch_hook = hook;
 180         else {
 181                 /*
 182                  * Any other hook name is valid and can
 183                  * later be associated with a filter rule.
 184                  */
 185         }
 186         NG_HOOK_SET_PRIVATE(hook, NULL);
 187         return (0);
 188 }
 189
 190 static int
 191 ng_vlan_rcvmsg(node_p node, item_p item, hook_p lasthook)
 192 {
 193         const priv_p priv = NG_NODE_PRIVATE(node);
 194         int error = 0;
 195         struct ng_mesg *msg, *resp = NULL;
 196         struct ng_vlan_filter *vf;
 197         struct filter *f;
 198         hook_p hook;
 199         struct ng_vlan_table *t;
 200         int i;
 201
 202         NGI_GET_MSG(item, msg);
 203         /* Deal with message according to cookie and command. */
 204         switch (msg->header.typecookie) {
 205         case NGM_VLAN_COOKIE:
 206                 switch (msg->header.cmd) {
 207                 case NGM_VLAN_ADD_FILTER:
 208                         /* Check that message is long enough. */
 209                         if (msg->header.arglen != sizeof(*vf)) {
 210                                 error = EINVAL;
 211                                 break;
 212                         }
 213                         vf = (struct ng_vlan_filter *)msg->data;
 214                         /* Sanity check the VLAN ID value. */
 215                         if (vf->vlan & ~EVL_VLID_MASK) {
 216                                 error = EINVAL;
 217                                 break;
 218                         }
 219                         /* Check that a referenced hook exists. */
 220                         hook = ng_findhook(node, vf->hook);
 221                         if (hook == NULL) {
 222                                 error = ENOENT;
 223                                 break;
 224                         }
 225                         /* And is not one of the special hooks. */
 226                         if (hook == priv->downstream_hook ||
 227                             hook == priv->nomatch_hook) {
 228                                 error = EINVAL;
 229                                 break;
 230                         }
 231                         /* And is not already in service. */
 232                         if (NG_HOOK_PRIVATE(hook) != NULL) {
 233                                 error = EEXIST;
 234                                 break;
 235                         }
 236                         /* Check we don't already trap this VLAN. */
 237                         if (ng_vlan_findentry(priv, vf->vlan)) {
 238                                 error = EEXIST;
 239                                 break;
 240                         }
 241                         /* Create filter. */
 242                         f = malloc(sizeof(*f),
 243                             M_NETGRAPH, M_NOWAIT | M_ZERO);
 244                         if (f == NULL) {
 245                                 error = ENOMEM;
 246                                 break;
 247                         }
 248                         /* Link filter and hook together. */
 249                         f->hook = hook;
 250                         f->vlan = vf->vlan;
 251                         NG_HOOK_SET_PRIVATE(hook, f);
 252                         /* Register filter in a hash table. */
 253                         LIST_INSERT_HEAD(
 254                             &priv->hashtable[HASH(f->vlan)], f, next);
 255                         priv->nent++;
 256                         break;
 257                 case NGM_VLAN_DEL_FILTER:
 258                         /* Check that message is long enough. */
 259                         if (msg->header.arglen != NG_HOOKSIZ) {
 260                                 error = EINVAL;
 261                                 break;
 262                         }
 263                         /* Check that hook exists and is active. */
 264                         hook = ng_findhook(node, (char *)msg->data);
 265                         if (hook == NULL ||
 266                             (f = NG_HOOK_PRIVATE(hook)) == NULL) {
 267                                 error = ENOENT;
 268                                 break;
 269                         }
 270                         /* Purge a rule that refers to this hook. */
 271                         NG_HOOK_SET_PRIVATE(hook, NULL);
 272                         LIST_REMOVE(f, next);
 273                         priv->nent--;
 274                         free(f, M_NETGRAPH);
 275                         break;
 276                 case NGM_VLAN_GET_TABLE:
 277                         NG_MKRESPONSE(resp, msg, sizeof(*t) +
 278                             priv->nent * sizeof(*t->filter), M_NOWAIT);
 279                         if (resp == NULL) {
 280                                 error = ENOMEM;
 281                                 break;
 282                         }
 283                         t = (struct ng_vlan_table *)resp->data;
 284                         t->n = priv->nent;
 285                         vf = &t->filter[0];
 286                         for (i = 0; i < HASHSIZE; i++) {
 287                                 LIST_FOREACH(f, &priv->hashtable[i], next) {
 288                                         vf->vlan = f->vlan;
 289                                         strncpy(vf->hook, NG_HOOK_NAME(f->hook),
 290                                             NG_HOOKSIZ);
 291                                         vf++;
 292                                 }
 293                         }
 294                         break;
 295                 default:                /* Unknown command. */
 296                         error = EINVAL;
 297                         break;
 298                 }
 299                 break;
 300         case NGM_FLOW_COOKIE:
 301             {
 302                 struct ng_mesg *copy;
 303                 struct filterhead *chain;
 304                 struct filter *f;
 305
 306                 /*
 307                  * Flow control messages should come only
 308                  * from downstream.
 309                  */
 310
 311                 if (lasthook == NULL)
 312                         break;
 313                 if (lasthook != priv->downstream_hook)
 314                         break;
 315
 316                 /* Broadcast the event to all uplinks. */
 317                 for (i = 0, chain = priv->hashtable; i < HASHSIZE;
 318                     i++, chain++)
 319                 LIST_FOREACH(f, chain, next) {
 320                         NG_COPYMESSAGE(copy, msg, M_NOWAIT);
 321                         if (copy == NULL)
 322                                 continue;
 323                         NG_SEND_MSG_HOOK(error, node, copy, f->hook, 0);
 324                 }
 325
 326                 break;
 327             }
 328         default:                        /* Unknown type cookie. */
 329                 error = EINVAL;
 330                 break;
 331         }
 332         NG_RESPOND_MSG(error, node, item, resp);
 333         NG_FREE_MSG(msg);
 334         return (error);
 335 }
 336
 337 static int
 338 ng_vlan_rcvdata(hook_p hook, item_p item)
 339 {
 340         const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 341         struct ether_header *eh;
 342         struct ether_vlan_header *evl = NULL;
 343         int error;
 344         u_int16_t vlan;
 345         struct mbuf *m;
 346         struct filter *f;
 347
 348         /* Make sure we have an entire header. */
 349         NGI_GET_M(item, m);
 350         if (m->m_len < sizeof(*eh) &&
 351             (m = m_pullup(m, sizeof(*eh))) == NULL) {
 352                 NG_FREE_ITEM(item);
 353                 return (EINVAL);
 354         }
 355         eh = mtod(m, struct ether_header *);
 356         if (hook == priv->downstream_hook) {
 357                 /*
 358                  * If from downstream, select between a match hook
 359                  * or the nomatch hook.
 360                  */
 361                 if (m->m_flags & M_VLANTAG ||
 362                     eh->ether_type == htons(ETHERTYPE_VLAN)) {
 363                         if (m->m_flags & M_VLANTAG) {
 364                                 /*
 365                                  * Packet is tagged, m contains a normal
 366                                  * Ethernet frame; tag is stored out-of-band.
 367                                  */
 368                                 vlan = EVL_VLANOFTAG(m->m_pkthdr.ether_vtag);
 369                         } else {
 370                                 if (m->m_len < sizeof(*evl) &&
 371                                     (m = m_pullup(m, sizeof(*evl))) == NULL) {
 372                                         NG_FREE_ITEM(item);
 373                                         return (EINVAL);
 374                                 }
 375                                 evl = mtod(m, struct ether_vlan_header *);
 376                                 vlan = EVL_VLANOFTAG(ntohs(evl->evl_tag));
 377                         }
 378                         if ((f = ng_vlan_findentry(priv, vlan)) != NULL) {
 379                                 if (m->m_flags & M_VLANTAG) {
 380                                         m->m_pkthdr.ether_vtag = 0;
 381                                         m->m_flags &= ~M_VLANTAG;
 382                                 } else {
 383                                         evl->evl_encap_proto = evl->evl_proto;
 384                                         bcopy(mtod(m, caddr_t),
 385                                             mtod(m, caddr_t) +
 386                                             ETHER_VLAN_ENCAP_LEN,
 387                                             ETHER_HDR_LEN);
 388                                         m_adj(m, ETHER_VLAN_ENCAP_LEN);
 389                                 }
 390                         }
 391                 } else
 392                         f = NULL;
 393                 if (f != NULL)
 394                         NG_FWD_NEW_DATA(error, item, f->hook, m);
 395                 else
 396                         NG_FWD_NEW_DATA(error, item, priv->nomatch_hook, m);
 397         } else {
 398                 /*
 399                  * It is heading towards the downstream.
 400                  * If from nomatch, pass it unmodified.
 401                  * Otherwise, do the VLAN encapsulation.
 402                  */
 403                 if (hook != priv->nomatch_hook) {
 404                         if ((f = NG_HOOK_PRIVATE(hook)) == NULL) {
 405                                 NG_FREE_ITEM(item);
 406                                 NG_FREE_M(m);
 407                                 return (EOPNOTSUPP);
 408                         }
 409                         M_PREPEND(m, ETHER_VLAN_ENCAP_LEN, M_DONTWAIT);
 410                         /* M_PREPEND takes care of m_len and m_pkthdr.len. */
 411                         if (m == NULL || (m->m_len < sizeof(*evl) &&
 412                             (m = m_pullup(m, sizeof(*evl))) == NULL)) {
 413                                 NG_FREE_ITEM(item);
 414                                 return (ENOMEM);
 415                         }
 416                         /*
 417                          * Transform the Ethernet header into an Ethernet header
 418                          * with 802.1Q encapsulation.
 419                          */
 420                         bcopy(mtod(m, char *) + ETHER_VLAN_ENCAP_LEN,
 421                             mtod(m, char *), ETHER_HDR_LEN);
 422                         evl = mtod(m, struct ether_vlan_header *);
 423                         evl->evl_proto = evl->evl_encap_proto;
 424                         evl->evl_encap_proto = htons(ETHERTYPE_VLAN);
 425                         evl->evl_tag = htons(f->vlan);
 426                 }
 427                 NG_FWD_NEW_DATA(error, item, priv->downstream_hook, m);
 428         }
 429         return (error);
 430 }
 431
 432 static int
 433 ng_vlan_shutdown(node_p node)
 434 {
 435         const priv_p priv = NG_NODE_PRIVATE(node);
 436
 437         NG_NODE_SET_PRIVATE(node, NULL);
 438         NG_NODE_UNREF(node);
 439         free(priv, M_NETGRAPH);
 440         return (0);
 441 }
 442
 443 static int
 444 ng_vlan_disconnect(hook_p hook)
 445 {
 446         const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 447         struct filter *f;
 448
 449         if (hook == priv->downstream_hook)
 450                 priv->downstream_hook = NULL;
 451         else if (hook == priv->nomatch_hook)
 452                 priv->nomatch_hook = NULL;
 453         else {
 454                 /* Purge a rule that refers to this hook. */
 455                 if ((f = NG_HOOK_PRIVATE(hook)) != NULL) {
 456                         LIST_REMOVE(f, next);
 457                         priv->nent--;
 458                         free(f, M_NETGRAPH);
 459                 }
 460         }
 461         NG_HOOK_SET_PRIVATE(hook, NULL);
 462         if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) &&
 463             (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
 464                 ng_rmnode_self(NG_HOOK_NODE(hook));
 465         return (0);
 466 }