sys/netgraph/ng_bridge.c

   1 /*-
   2  * Copyright (c) 2000 Whistle Communications, Inc.
   3  * All rights reserved.
   4  *
   5  * Subject to the following obligations and disclaimer of warranty, use and
   6  * redistribution of this software, in source or object code forms, with or
   7  * without modifications are expressly permitted by Whistle Communications;
   8  * provided, however, that:
   9  * 1. Any and all reproductions of the source or object code must include the
  10  *    copyright notice above and the following disclaimer of warranties; and
  11  * 2. No rights are granted, in any manner or form, to use Whistle
  12  *    Communications, Inc. trademarks, including the mark "WHISTLE
  13  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
  14  *    such appears in the above copyright notice or in the software.
  15  *
  16  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
  17  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
  18  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
  19  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
  21  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
  22  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
  23  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
  24  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
  25  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
  26  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
  27  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
  28  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
  29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  31  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
  32  * OF SUCH DAMAGE.
  33  *
  34  * Author: Archie Cobbs <archie@freebsd.org>
  35  *
  36  * $FreeBSD$
  37  */
  38
  39 /*
  40  * ng_bridge(4) netgraph node type
  41  *
  42  * The node performs standard intelligent Ethernet bridging over
  43  * each of its connected hooks, or links.  A simple loop detection
  44  * algorithm is included which disables a link for priv->conf.loopTimeout
  45  * seconds when a host is seen to have jumped from one link to
  46  * another within priv->conf.minStableAge seconds.
  47  *
  48  * We keep a hashtable that maps Ethernet addresses to host info,
  49  * which is contained in struct ng_bridge_host's. These structures
  50  * tell us on which link the host may be found. A host's entry will
  51  * expire after priv->conf.maxStaleness seconds.
  52  *
  53  * This node is optimzed for stable networks, where machines jump
  54  * from one port to the other only rarely.
  55  */
  56
  57 #include <sys/param.h>
  58 #include <sys/systm.h>
  59 #include <sys/kernel.h>
  60 #include <sys/lock.h>
  61 #include <sys/malloc.h>
  62 #include <sys/mbuf.h>
  63 #include <sys/errno.h>
  64 #include <sys/rwlock.h>
  65 #include <sys/syslog.h>
  66 #include <sys/socket.h>
  67 #include <sys/ctype.h>
  68
  69 #include <net/if.h>
  70 #include <net/if_var.h>
  71 #include <net/ethernet.h>
  72 #include <net/vnet.h>
  73
  74 #include <netinet/in.h>
  75 #if 0   /* not used yet */
  76 #include <netinet/ip_fw.h>
  77 #endif
  78 #include <netgraph/ng_message.h>
  79 #include <netgraph/netgraph.h>
  80 #include <netgraph/ng_parse.h>
  81 #include <netgraph/ng_bridge.h>
  82
  83 #ifdef NG_SEPARATE_MALLOC
  84 static MALLOC_DEFINE(M_NETGRAPH_BRIDGE, "netgraph_bridge",
  85     "netgraph bridge node");
  86 #else
  87 #define M_NETGRAPH_BRIDGE M_NETGRAPH
  88 #endif
  89
  90 /* Per-link private data */
  91 struct ng_bridge_link {
  92         hook_p                          hook;           /* netgraph hook */
  93         u_int16_t                       loopCount;      /* loop ignore timer */
  94         struct ng_bridge_link_stats     stats;          /* link stats */
  95 };
  96
  97 /* Per-node private data */
  98 struct ng_bridge_private {
  99         struct ng_bridge_bucket *tab;           /* hash table bucket array */
 100         struct ng_bridge_config conf;           /* node configuration */
 101         node_p                  node;           /* netgraph node */
 102         u_int                   numHosts;       /* num entries in table */
 103         u_int                   numBuckets;     /* num buckets in table */
 104         u_int                   hashMask;       /* numBuckets - 1 */
 105         int                     numLinks;       /* num connected links */
 106         int                     persistent;     /* can exist w/o hooks */
 107         struct callout          timer;          /* one second periodic timer */
 108 };
 109 typedef struct ng_bridge_private *priv_p;
 110
 111 /* Information about a host, stored in a hash table entry */
 112 struct ng_bridge_hent {
 113         struct ng_bridge_host           host;   /* actual host info */
 114         SLIST_ENTRY(ng_bridge_hent)     next;   /* next entry in bucket */
 115 };
 116
 117 /* Hash table bucket declaration */
 118 SLIST_HEAD(ng_bridge_bucket, ng_bridge_hent);
 119
 120 /* Netgraph node methods */
 121 static ng_constructor_t ng_bridge_constructor;
 122 static ng_rcvmsg_t      ng_bridge_rcvmsg;
 123 static ng_shutdown_t    ng_bridge_shutdown;
 124 static ng_newhook_t     ng_bridge_newhook;
 125 static ng_rcvdata_t     ng_bridge_rcvdata;
 126 static ng_disconnect_t  ng_bridge_disconnect;
 127
 128 /* Other internal functions */
 129 static struct   ng_bridge_host *ng_bridge_get(priv_p priv, const u_char *addr);
 130 static int      ng_bridge_put(priv_p priv, const u_char *addr, link_p link);
 131 static void     ng_bridge_rehash(priv_p priv);
 132 static void     ng_bridge_remove_hosts(priv_p priv, link_p link);
 133 static void     ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2);
 134 static const    char *ng_bridge_nodename(node_p node);
 135
 136 /* Ethernet broadcast */
 137 static const u_char ng_bridge_bcast_addr[ETHER_ADDR_LEN] =
 138     { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
 139
 140 /* Compare Ethernet addresses using 32 and 16 bit words instead of bytewise */
 141 #define ETHER_EQUAL(a,b)        (((const u_int32_t *)(a))[0] \
 142                                         == ((const u_int32_t *)(b))[0] \
 143                                     && ((const u_int16_t *)(a))[2] \
 144                                         == ((const u_int16_t *)(b))[2])
 145
 146 /* Minimum and maximum number of hash buckets. Must be a power of two. */
 147 #define MIN_BUCKETS             (1 << 5)        /* 32 */
 148 #define MAX_BUCKETS             (1 << 14)       /* 16384 */
 149
 150 /* Configuration default values */
 151 #define DEFAULT_LOOP_TIMEOUT    60
 152 #define DEFAULT_MAX_STALENESS   (15 * 60)       /* same as ARP timeout */
 153 #define DEFAULT_MIN_STABLE_AGE  1
 154
 155 /******************************************************************
 156                     NETGRAPH PARSE TYPES
 157 ******************************************************************/
 158
 159 /*
 160  * How to determine the length of the table returned by NGM_BRIDGE_GET_TABLE
 161  */
 162 static int
 163 ng_bridge_getTableLength(const struct ng_parse_type *type,
 164         const u_char *start, const u_char *buf)
 165 {
 166         const struct ng_bridge_host_ary *const hary
 167             = (const struct ng_bridge_host_ary *)(buf - sizeof(u_int32_t));
 168
 169         return hary->numHosts;
 170 }
 171
 172 /* Parse type for struct ng_bridge_host_ary */
 173 static const struct ng_parse_struct_field ng_bridge_host_type_fields[]
 174         = NG_BRIDGE_HOST_TYPE_INFO(&ng_parse_enaddr_type);
 175 static const struct ng_parse_type ng_bridge_host_type = {
 176         &ng_parse_struct_type,
 177         &ng_bridge_host_type_fields
 178 };
 179 static const struct ng_parse_array_info ng_bridge_hary_type_info = {
 180         &ng_bridge_host_type,
 181         ng_bridge_getTableLength
 182 };
 183 static const struct ng_parse_type ng_bridge_hary_type = {
 184         &ng_parse_array_type,
 185         &ng_bridge_hary_type_info
 186 };
 187 static const struct ng_parse_struct_field ng_bridge_host_ary_type_fields[]
 188         = NG_BRIDGE_HOST_ARY_TYPE_INFO(&ng_bridge_hary_type);
 189 static const struct ng_parse_type ng_bridge_host_ary_type = {
 190         &ng_parse_struct_type,
 191         &ng_bridge_host_ary_type_fields
 192 };
 193
 194 /* Parse type for struct ng_bridge_config */
 195 static const struct ng_parse_struct_field ng_bridge_config_type_fields[]
 196         = NG_BRIDGE_CONFIG_TYPE_INFO;
 197 static const struct ng_parse_type ng_bridge_config_type = {
 198         &ng_parse_struct_type,
 199         &ng_bridge_config_type_fields
 200 };
 201
 202 /* Parse type for struct ng_bridge_link_stat */
 203 static const struct ng_parse_struct_field ng_bridge_stats_type_fields[]
 204         = NG_BRIDGE_STATS_TYPE_INFO;
 205 static const struct ng_parse_type ng_bridge_stats_type = {
 206         &ng_parse_struct_type,
 207         &ng_bridge_stats_type_fields
 208 };
 209
 210 /* List of commands and how to convert arguments to/from ASCII */
 211 static const struct ng_cmdlist ng_bridge_cmdlist[] = {
 212         {
 213           NGM_BRIDGE_COOKIE,
 214           NGM_BRIDGE_SET_CONFIG,
 215           "setconfig",
 216           &ng_bridge_config_type,
 217           NULL
 218         },
 219         {
 220           NGM_BRIDGE_COOKIE,
 221           NGM_BRIDGE_GET_CONFIG,
 222           "getconfig",
 223           NULL,
 224           &ng_bridge_config_type
 225         },
 226         {
 227           NGM_BRIDGE_COOKIE,
 228           NGM_BRIDGE_RESET,
 229           "reset",
 230           NULL,
 231           NULL
 232         },
 233         {
 234           NGM_BRIDGE_COOKIE,
 235           NGM_BRIDGE_GET_STATS,
 236           "getstats",
 237           &ng_parse_uint32_type,
 238           &ng_bridge_stats_type
 239         },
 240         {
 241           NGM_BRIDGE_COOKIE,
 242           NGM_BRIDGE_CLR_STATS,
 243           "clrstats",
 244           &ng_parse_uint32_type,
 245           NULL
 246         },
 247         {
 248           NGM_BRIDGE_COOKIE,
 249           NGM_BRIDGE_GETCLR_STATS,
 250           "getclrstats",
 251           &ng_parse_uint32_type,
 252           &ng_bridge_stats_type
 253         },
 254         {
 255           NGM_BRIDGE_COOKIE,
 256           NGM_BRIDGE_GET_TABLE,
 257           "gettable",
 258           NULL,
 259           &ng_bridge_host_ary_type
 260         },
 261         {
 262           NGM_BRIDGE_COOKIE,
 263           NGM_BRIDGE_SET_PERSISTENT,
 264           "setpersistent",
 265           NULL,
 266           NULL
 267         },
 268         { 0 }
 269 };
 270
 271 /* Node type descriptor */
 272 static struct ng_type ng_bridge_typestruct = {
 273         .version =      NG_ABI_VERSION,
 274         .name =         NG_BRIDGE_NODE_TYPE,
 275         .constructor =  ng_bridge_constructor,
 276         .rcvmsg =       ng_bridge_rcvmsg,
 277         .shutdown =     ng_bridge_shutdown,
 278         .newhook =      ng_bridge_newhook,
 279         .rcvdata =      ng_bridge_rcvdata,
 280         .disconnect =   ng_bridge_disconnect,
 281         .cmdlist =      ng_bridge_cmdlist,
 282 };
 283 NETGRAPH_INIT(bridge, &ng_bridge_typestruct);
 284
 285 /******************************************************************
 286                     NETGRAPH NODE METHODS
 287 ******************************************************************/
 288
 289 /*
 290  * Node constructor
 291  */
 292 static int
 293 ng_bridge_constructor(node_p node)
 294 {
 295         priv_p priv;
 296
 297         /* Allocate and initialize private info */
 298         priv = malloc(sizeof(*priv), M_NETGRAPH_BRIDGE, M_WAITOK | M_ZERO);
 299         ng_callout_init(&priv->timer);
 300
 301         /* Allocate and initialize hash table, etc. */
 302         priv->tab = malloc(MIN_BUCKETS * sizeof(*priv->tab),
 303             M_NETGRAPH_BRIDGE, M_WAITOK | M_ZERO);
 304         priv->numBuckets = MIN_BUCKETS;
 305         priv->hashMask = MIN_BUCKETS - 1;
 306         priv->conf.debugLevel = 1;
 307         priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT;
 308         priv->conf.maxStaleness = DEFAULT_MAX_STALENESS;
 309         priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE;
 310
 311         /*
 312          * This node has all kinds of stuff that could be screwed by SMP.
 313          * Until it gets it's own internal protection, we go through in
 314          * single file. This could hurt a machine bridging between two
 315          * GB ethernets so it should be fixed.
 316          * When it's fixed the process SHOULD NOT SLEEP, spinlocks please!
 317          * (and atomic ops )
 318          */
 319         NG_NODE_FORCE_WRITER(node);
 320         NG_NODE_SET_PRIVATE(node, priv);
 321         priv->node = node;
 322
 323         /* Start timer; timer is always running while node is alive */
 324         ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0);
 325
 326         /* Done */
 327         return (0);
 328 }
 329
 330 /*
 331  * Method for attaching a new hook
 332  */
 333 static  int
 334 ng_bridge_newhook(node_p node, hook_p hook, const char *name)
 335 {
 336         const priv_p priv = NG_NODE_PRIVATE(node);
 337
 338         /* Check for a link hook */
 339         if (strlen(name) > strlen(NG_BRIDGE_HOOK_LINK_PREFIX)) {
 340                 char linkName[NG_HOOKSIZ];
 341                 u_int32_t linkNum;
 342                 link_p link;
 343
 344                 /* primitive parsing */
 345                 linkNum = strtoul(name + strlen(NG_BRIDGE_HOOK_LINK_PREFIX),
 346                                   NULL, 10);
 347                 /* validation by comparing against the reconstucted name  */
 348                 snprintf(linkName, sizeof(linkName),
 349                          "%s%u", NG_BRIDGE_HOOK_LINK_PREFIX,
 350                          linkNum);
 351                 if (strcmp(linkName, name) != 0)
 352                         return (EINVAL);
 353
 354                 if(NG_PEER_NODE(hook) == node)
 355                         return (ELOOP);
 356
 357                 link = malloc(sizeof(*link), M_NETGRAPH_BRIDGE,
 358                               M_WAITOK|M_ZERO);
 359                 if (link == NULL)
 360                         return (ENOMEM);
 361                 link->hook = hook;
 362                 NG_HOOK_SET_PRIVATE(hook, link);
 363                 priv->numLinks++;
 364                 return (0);
 365         }
 366
 367         /* Unknown hook name */
 368         return (EINVAL);
 369 }
 370
 371 /*
 372  * Receive a control message
 373  */
 374 static int
 375 ng_bridge_reset_link(hook_p hook, void *arg __unused)
 376 {
 377         link_p priv = NG_HOOK_PRIVATE(hook);
 378
 379         priv->loopCount = 0;
 380         bzero(&priv->stats, sizeof(priv->stats));
 381
 382         return (1);
 383 }
 384
 385 static int
 386 ng_bridge_rcvmsg(node_p node, item_p item, hook_p lasthook)
 387 {
 388         const priv_p priv = NG_NODE_PRIVATE(node);
 389         struct ng_mesg *resp = NULL;
 390         int error = 0;
 391         struct ng_mesg *msg;
 392
 393         NGI_GET_MSG(item, msg);
 394         switch (msg->header.typecookie) {
 395 #ifdef NGM_BRIDGE_TABLE_ABI
 396         case NGM_BRIDGE_COOKIE_TBL:
 397                 switch (msg->header.cmd) {
 398                 case NGM_BRIDGE_GET_CONFIG:
 399                     {
 400                         struct ng_bridge_config_tbl *conf;
 401
 402                         NG_MKRESPONSE(resp, msg, sizeof(*conf),
 403                             M_NOWAIT|M_ZERO);
 404                         if (resp == NULL) {
 405                                 error = ENOMEM;
 406                                 break;
 407                         }
 408                         conf = (struct ng_bridge_config_tbl *)resp->data;
 409                         conf->cfg = priv->conf;
 410                         break;
 411                     }
 412                 case NGM_BRIDGE_SET_CONFIG:
 413                     {
 414                         struct ng_bridge_config_tbl *conf;
 415
 416                         if (msg->header.arglen != sizeof(*conf)) {
 417                                 error = EINVAL;
 418                                 break;
 419                         }
 420                         conf = (struct ng_bridge_config_tbl *)msg->data;
 421                         priv->conf = conf->cfg;
 422                         break;
 423                     }
 424                 case NGM_BRIDGE_GET_TABLE:
 425                     {
 426                         struct ng_bridge_host_tbl_ary *ary;
 427                         struct ng_bridge_hent *hent;
 428                         int i, bucket;
 429
 430                         NG_MKRESPONSE(resp, msg, sizeof(*ary) +
 431                             (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT);
 432                         if (resp == NULL) {
 433                                 error = ENOMEM;
 434                                 break;
 435                         }
 436                         ary = (struct ng_bridge_host_tbl_ary *)resp->data;
 437                         ary->numHosts = priv->numHosts;
 438                         i = 0;
 439                         for (bucket = 0; bucket < priv->numBuckets; bucket++) {
 440                                 SLIST_FOREACH(hent, &priv->tab[bucket], next) {
 441                                         memcpy(ary->hosts[i].addr,
 442                                             hent->host.addr,
 443                                             sizeof(ary->hosts[i].addr));
 444                                         ary->hosts[i].age = hent->host.age;
 445                                         ary->hosts[i].staleness =
 446                                              hent->host.staleness;
 447                                         ary->hosts[i].linkNum = strtol(
 448                                             NG_HOOK_NAME(hent->host.link->hook) +
 449                                             strlen(NG_BRIDGE_HOOK_LINK_PREFIX),
 450                                             NULL, 10);
 451                                         i++;
 452                                 }
 453                         }
 454                         break;
 455                     }
 456                 }
 457                 /* If already handled break, otherwise use new ABI. */
 458                 if (resp != NULL || error != 0)
 459                     break;
 460 #endif /* NGM_BRIDGE_TABLE_ABI */
 461         case NGM_BRIDGE_COOKIE:
 462                 switch (msg->header.cmd) {
 463                 case NGM_BRIDGE_GET_CONFIG:
 464                     {
 465                         struct ng_bridge_config *conf;
 466
 467                         NG_MKRESPONSE(resp, msg,
 468                             sizeof(struct ng_bridge_config), M_NOWAIT);
 469                         if (resp == NULL) {
 470                                 error = ENOMEM;
 471                                 break;
 472                         }
 473                         conf = (struct ng_bridge_config *)resp->data;
 474                         *conf = priv->conf;     /* no sanity checking needed */
 475                         break;
 476                     }
 477                 case NGM_BRIDGE_SET_CONFIG:
 478                     {
 479                         struct ng_bridge_config *conf;
 480
 481                         if (msg->header.arglen
 482                             != sizeof(struct ng_bridge_config)) {
 483                                 error = EINVAL;
 484                                 break;
 485                         }
 486                         conf = (struct ng_bridge_config *)msg->data;
 487                         priv->conf = *conf;
 488                         break;
 489                     }
 490                 case NGM_BRIDGE_RESET:
 491                     {
 492                         hook_p rethook;
 493
 494                         /* Flush all entries in the hash table */
 495                         ng_bridge_remove_hosts(priv, NULL);
 496
 497                         /* Reset all loop detection counters and stats */
 498                         NG_NODE_FOREACH_HOOK(node, ng_bridge_reset_link, NULL,
 499                             rethook);
 500                         break;
 501                     }
 502                 case NGM_BRIDGE_GET_STATS:
 503                 case NGM_BRIDGE_CLR_STATS:
 504                 case NGM_BRIDGE_GETCLR_STATS:
 505                     {
 506                         hook_p hook;
 507                         link_p link;
 508                         char linkName[NG_HOOKSIZ];
 509
 510                         /* Get link number */
 511                         if (msg->header.arglen != sizeof(u_int32_t)) {
 512                                 error = EINVAL;
 513                                 break;
 514                         }
 515                         snprintf(linkName, sizeof(linkName),
 516                                  "%s%u", NG_BRIDGE_HOOK_LINK_PREFIX,
 517                                  *((u_int32_t *)msg->data));
 518
 519                         if ((hook = ng_findhook(node, linkName)) == NULL) {
 520                                 error = ENOTCONN;
 521                                 break;
 522                         }
 523                         link = NG_HOOK_PRIVATE(hook);
 524
 525                         /* Get/clear stats */
 526                         if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) {
 527                                 NG_MKRESPONSE(resp, msg,
 528                                     sizeof(link->stats), M_NOWAIT);
 529                                 if (resp == NULL) {
 530                                         error = ENOMEM;
 531                                         break;
 532                                 }
 533                                 bcopy(&link->stats,
 534                                     resp->data, sizeof(link->stats));
 535                         }
 536                         if (msg->header.cmd != NGM_BRIDGE_GET_STATS)
 537                                 bzero(&link->stats, sizeof(link->stats));
 538                         break;
 539                     }
 540                 case NGM_BRIDGE_GET_TABLE:
 541                     {
 542                         struct ng_bridge_host_ary *ary;
 543                         struct ng_bridge_hent *hent;
 544                         int i = 0, bucket;
 545
 546                         NG_MKRESPONSE(resp, msg, sizeof(*ary)
 547                             + (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT);
 548                         if (resp == NULL) {
 549                                 error = ENOMEM;
 550                                 break;
 551                         }
 552                         ary = (struct ng_bridge_host_ary *)resp->data;
 553                         ary->numHosts = priv->numHosts;
 554                         for (bucket = 0; bucket < priv->numBuckets; bucket++) {
 555                                 SLIST_FOREACH(hent, &priv->tab[bucket], next) {
 556                                         memcpy(ary->hosts[i].addr,
 557                                                hent->host.addr,
 558                                                sizeof(ary->hosts[i].addr));
 559                                         ary->hosts[i].age       = hent->host.age;
 560                                         ary->hosts[i].staleness = hent->host.staleness;
 561                                         strncpy(ary->hosts[i].hook,
 562                                                 NG_HOOK_NAME(hent->host.link->hook),
 563                                                 sizeof(ary->hosts[i].hook));
 564                                         i++;
 565                                 }
 566                         }
 567                         break;
 568                     }
 569                 case NGM_BRIDGE_SET_PERSISTENT:
 570                     {
 571                         priv->persistent = 1;
 572                         break;
 573                     }
 574                 default:
 575                         error = EINVAL;
 576                         break;
 577                 }
 578                 break;
 579         default:
 580                 error = EINVAL;
 581                 break;
 582         }
 583
 584         /* Done */
 585         NG_RESPOND_MSG(error, node, item, resp);
 586         NG_FREE_MSG(msg);
 587         return (error);
 588 }
 589
 590 /*
 591  * Receive data on a hook
 592  */
 593 struct ng_bridge_send_ctx {
 594         link_p foundFirst, incoming;
 595         struct mbuf * m;
 596         int manycast, error;
 597 };
 598
 599 static int
 600 ng_bridge_send_ctx(hook_p dst, void *arg)
 601 {
 602         struct ng_bridge_send_ctx *ctx = arg;
 603         link_p destLink = NG_HOOK_PRIVATE(dst);
 604         struct mbuf *m2 = NULL;
 605         int error = 0;
 606
 607         /* Skip incoming link */
 608         if (destLink == ctx->incoming) {
 609                 return (1);
 610         }
 611
 612         if (ctx->foundFirst == NULL) {
 613                 /*
 614                  * This is the first usable link we have found.
 615                  * Reserve it for the originals.
 616                  * If we never find another we save a copy.
 617                  */
 618                 ctx->foundFirst = destLink;
 619                 return (1);
 620         }
 621
 622         /*
 623          * It's usable link but not the reserved (first) one.
 624          * Copy mbuf info for sending.
 625          */
 626         m2 = m_dup(ctx->m, M_NOWAIT);   /* XXX m_copypacket() */
 627         if (m2 == NULL) {
 628                 ctx->incoming->stats.memoryFailures++;
 629                 ctx->error = ENOBUFS;
 630                 return (0);            /* abort loop */
 631         }
 632
 633         /* Update stats */
 634         destLink->stats.xmitPackets++;
 635         destLink->stats.xmitOctets += m2->m_pkthdr.len;
 636         switch (ctx->manycast) {
 637          default:                                       /* unknown unicast */
 638                 break;
 639          case 1:                                        /* multicast */
 640                 destLink->stats.xmitMulticasts++;
 641                 break;
 642          case 2:                                        /* broadcast */
 643                 destLink->stats.xmitBroadcasts++;
 644                 break;
 645         }
 646
 647         /* Send packet */
 648         NG_SEND_DATA_ONLY(error, destLink->hook, m2);
 649         if(error)
 650           ctx->error = error;
 651         return (1);
 652 }
 653
 654 static int
 655 ng_bridge_rcvdata(hook_p hook, item_p item)
 656 {
 657         const node_p node = NG_HOOK_NODE(hook);
 658         const priv_p priv = NG_NODE_PRIVATE(node);
 659         struct ng_bridge_host *host;
 660         struct ether_header *eh;
 661         struct ng_bridge_send_ctx ctx = { 0 };
 662         hook_p ret;
 663
 664         NGI_GET_M(item, ctx.m);
 665
 666         ctx.incoming = NG_HOOK_PRIVATE(hook);
 667         /* Sanity check packet and pull up header */
 668         if (ctx.m->m_pkthdr.len < ETHER_HDR_LEN) {
 669                 ctx.incoming->stats.recvRunts++;
 670                 NG_FREE_ITEM(item);
 671                 NG_FREE_M(ctx.m);
 672                 return (EINVAL);
 673         }
 674         if (ctx.m->m_len < ETHER_HDR_LEN && !(ctx.m = m_pullup(ctx.m, ETHER_HDR_LEN))) {
 675                 ctx.incoming->stats.memoryFailures++;
 676                 NG_FREE_ITEM(item);
 677                 return (ENOBUFS);
 678         }
 679         eh = mtod(ctx.m, struct ether_header *);
 680         if ((eh->ether_shost[0] & 1) != 0) {
 681                 ctx.incoming->stats.recvInvalid++;
 682                 NG_FREE_ITEM(item);
 683                 NG_FREE_M(ctx.m);
 684                 return (EINVAL);
 685         }
 686
 687         /* Is link disabled due to a loopback condition? */
 688         if (ctx.incoming->loopCount != 0) {
 689                 ctx.incoming->stats.loopDrops++;
 690                 NG_FREE_ITEM(item);
 691                 NG_FREE_M(ctx.m);
 692                 return (ELOOP);         /* XXX is this an appropriate error? */
 693         }
 694
 695         /* Update stats */
 696         ctx.incoming->stats.recvPackets++;
 697         ctx.incoming->stats.recvOctets += ctx.m->m_pkthdr.len;
 698         if ((ctx.manycast = (eh->ether_dhost[0] & 1)) != 0) {
 699                 if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) {
 700                         ctx.incoming->stats.recvBroadcasts++;
 701                         ctx.manycast = 2;
 702                 } else
 703                         ctx.incoming->stats.recvMulticasts++;
 704         }
 705
 706         /* Look up packet's source Ethernet address in hashtable */
 707         if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) {
 708                 /* Update time since last heard from this host */
 709                 host->staleness = 0;
 710
 711                 /* Did host jump to a different link? */
 712                 if (host->link != ctx.incoming) {
 713                         /*
 714                          * If the host's old link was recently established
 715                          * on the old link and it's already jumped to a new
 716                          * link, declare a loopback condition.
 717                          */
 718                         if (host->age < priv->conf.minStableAge) {
 719                                 /* Log the problem */
 720                                 if (priv->conf.debugLevel >= 2) {
 721                                         struct ifnet *ifp = ctx.m->m_pkthdr.rcvif;
 722                                         char suffix[32];
 723
 724                                         if (ifp != NULL)
 725                                                 snprintf(suffix, sizeof(suffix),
 726                                                     " (%s)", ifp->if_xname);
 727                                         else
 728                                                 *suffix = '\0';
 729                                         log(LOG_WARNING, "ng_bridge: %s:"
 730                                             " loopback detected on %s%s\n",
 731                                             ng_bridge_nodename(node),
 732                                             NG_HOOK_NAME(hook), suffix);
 733                                 }
 734
 735                                 /* Mark link as linka non grata */
 736                                 ctx.incoming->loopCount = priv->conf.loopTimeout;
 737                                 ctx.incoming->stats.loopDetects++;
 738
 739                                 /* Forget all hosts on this link */
 740                                 ng_bridge_remove_hosts(priv, ctx.incoming);
 741
 742                                 /* Drop packet */
 743                                 ctx.incoming->stats.loopDrops++;
 744                                 NG_FREE_ITEM(item);
 745                                 NG_FREE_M(ctx.m);
 746                                 return (ELOOP);         /* XXX appropriate? */
 747                         }
 748
 749                         /* Move host over to new link */
 750                         host->link = ctx.incoming;
 751                         host->age = 0;
 752                 }
 753         } else {
 754                 if (!ng_bridge_put(priv, eh->ether_shost, ctx.incoming)) {
 755                         ctx.incoming->stats.memoryFailures++;
 756                         NG_FREE_ITEM(item);
 757                         NG_FREE_M(ctx.m);
 758                         return (ENOMEM);
 759                 }
 760         }
 761
 762         /* Run packet through ipfw processing, if enabled */
 763 #if 0
 764         if (priv->conf.ipfw[linkNum] && V_fw_enable && V_ip_fw_chk_ptr != NULL) {
 765                 /* XXX not implemented yet */
 766         }
 767 #endif
 768
 769         /*
 770          * If unicast and destination host known, deliver to host's link,
 771          * unless it is the same link as the packet came in on.
 772          */
 773         if (!ctx.manycast) {
 774                 /* Determine packet destination link */
 775                 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) {
 776                         link_p destLink = host->link;
 777
 778                         /* If destination same as incoming link, do nothing */
 779                         if (destLink == ctx.incoming) {
 780                                 NG_FREE_ITEM(item);
 781                                 NG_FREE_M(ctx.m);
 782                                 return (0);
 783                         }
 784
 785                         /* Deliver packet out the destination link */
 786                         destLink->stats.xmitPackets++;
 787                         destLink->stats.xmitOctets += ctx.m->m_pkthdr.len;
 788                         NG_FWD_NEW_DATA(ctx.error, item, destLink->hook, ctx.m);
 789                         return (ctx.error);
 790                 }
 791
 792                 /* Destination host is not known */
 793                 ctx.incoming->stats.recvUnknown++;
 794         }
 795
 796         /* Distribute unknown, multicast, broadcast pkts to all other links */
 797         NG_NODE_FOREACH_HOOK(node, ng_bridge_send_ctx, &ctx, ret);
 798
 799         /* If we never saw a good link, leave. */
 800         if (ctx.foundFirst == NULL || ctx.error != 0) {
 801                 NG_FREE_ITEM(item);
 802                 NG_FREE_M(ctx.m);
 803                 return (ctx.error);
 804         }
 805
 806         /*
 807          * If we've sent all the others, send the original
 808          * on the first link we found.
 809          */
 810         NG_FWD_NEW_DATA(ctx.error, item, ctx.foundFirst->hook, ctx.m);
 811         return (ctx.error);
 812 }
 813
 814 /*
 815  * Shutdown node
 816  */
 817 static int
 818 ng_bridge_shutdown(node_p node)
 819 {
 820         const priv_p priv = NG_NODE_PRIVATE(node);
 821
 822         /*
 823          * Shut down everything including the timer.  Even if the
 824          * callout has already been dequeued and is about to be
 825          * run, ng_bridge_timeout() won't be fired as the node
 826          * is already marked NGF_INVALID, so we're safe to free
 827          * the node now.
 828          */
 829         KASSERT(priv->numLinks == 0 && priv->numHosts == 0,
 830             ("%s: numLinks=%d numHosts=%d",
 831             __func__, priv->numLinks, priv->numHosts));
 832         ng_uncallout(&priv->timer, node);
 833         NG_NODE_SET_PRIVATE(node, NULL);
 834         NG_NODE_UNREF(node);
 835         free(priv->tab, M_NETGRAPH_BRIDGE);
 836         free(priv, M_NETGRAPH_BRIDGE);
 837         return (0);
 838 }
 839
 840 /*
 841  * Hook disconnection.
 842  */
 843 static int
 844 ng_bridge_disconnect(hook_p hook)
 845 {
 846         const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 847         link_p link = NG_HOOK_PRIVATE(hook);
 848
 849         /* Remove all hosts associated with this link */
 850         ng_bridge_remove_hosts(priv, link);
 851
 852         /* Free associated link information */
 853         free(link, M_NETGRAPH_BRIDGE);
 854         priv->numLinks--;
 855
 856         /* If no more hooks, go away */
 857         if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
 858             && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))
 859             && !priv->persistent) {
 860                 ng_rmnode_self(NG_HOOK_NODE(hook));
 861         }
 862         return (0);
 863 }
 864
 865 /******************************************************************
 866                     HASH TABLE FUNCTIONS
 867 ******************************************************************/
 868
 869 /*
 870  * Hash algorithm
 871  */
 872 #define HASH(addr,mask)         ( (((const u_int16_t *)(addr))[0]       \
 873                                  ^ ((const u_int16_t *)(addr))[1]       \
 874                                  ^ ((const u_int16_t *)(addr))[2]) & (mask) )
 875
 876 /*
 877  * Find a host entry in the table.
 878  */
 879 static struct ng_bridge_host *
 880 ng_bridge_get(priv_p priv, const u_char *addr)
 881 {
 882         const int bucket = HASH(addr, priv->hashMask);
 883         struct ng_bridge_hent *hent;
 884
 885         SLIST_FOREACH(hent, &priv->tab[bucket], next) {
 886                 if (ETHER_EQUAL(hent->host.addr, addr))
 887                         return (&hent->host);
 888         }
 889         return (NULL);
 890 }
 891
 892 /*
 893  * Add a new host entry to the table. This assumes the host doesn't
 894  * already exist in the table. Returns 1 on success, 0 if there
 895  * was a memory allocation failure.
 896  */
 897 static int
 898 ng_bridge_put(priv_p priv, const u_char *addr, link_p link)
 899 {
 900         const int bucket = HASH(addr, priv->hashMask);
 901         struct ng_bridge_hent *hent;
 902
 903 #ifdef INVARIANTS
 904         /* Assert that entry does not already exist in hashtable */
 905         SLIST_FOREACH(hent, &priv->tab[bucket], next) {
 906                 KASSERT(!ETHER_EQUAL(hent->host.addr, addr),
 907                     ("%s: entry %6D exists in table", __func__, addr, ":"));
 908         }
 909 #endif
 910
 911         /* Allocate and initialize new hashtable entry */
 912         hent = malloc(sizeof(*hent), M_NETGRAPH_BRIDGE, M_NOWAIT);
 913         if (hent == NULL)
 914                 return (0);
 915         bcopy(addr, hent->host.addr, ETHER_ADDR_LEN);
 916         hent->host.link = link;
 917         hent->host.staleness = 0;
 918         hent->host.age = 0;
 919
 920         /* Add new element to hash bucket */
 921         SLIST_INSERT_HEAD(&priv->tab[bucket], hent, next);
 922         priv->numHosts++;
 923
 924         /* Resize table if necessary */
 925         ng_bridge_rehash(priv);
 926         return (1);
 927 }
 928
 929 /*
 930  * Resize the hash table. We try to maintain the number of buckets
 931  * such that the load factor is in the range 0.25 to 1.0.
 932  *
 933  * If we can't get the new memory then we silently fail. This is OK
 934  * because things will still work and we'll try again soon anyway.
 935  */
 936 static void
 937 ng_bridge_rehash(priv_p priv)
 938 {
 939         struct ng_bridge_bucket *newTab;
 940         int oldBucket, newBucket;
 941         int newNumBuckets;
 942         u_int newMask;
 943
 944         /* Is table too full or too empty? */
 945         if (priv->numHosts > priv->numBuckets
 946             && (priv->numBuckets << 1) <= MAX_BUCKETS)
 947                 newNumBuckets = priv->numBuckets << 1;
 948         else if (priv->numHosts < (priv->numBuckets >> 2)
 949             && (priv->numBuckets >> 2) >= MIN_BUCKETS)
 950                 newNumBuckets = priv->numBuckets >> 2;
 951         else
 952                 return;
 953         newMask = newNumBuckets - 1;
 954
 955         /* Allocate and initialize new table */
 956         newTab = malloc(newNumBuckets * sizeof(*newTab),
 957             M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO);
 958         if (newTab == NULL)
 959                 return;
 960
 961         /* Move all entries from old table to new table */
 962         for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) {
 963                 struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket];
 964
 965                 while (!SLIST_EMPTY(oldList)) {
 966                         struct ng_bridge_hent *const hent
 967                             = SLIST_FIRST(oldList);
 968
 969                         SLIST_REMOVE_HEAD(oldList, next);
 970                         newBucket = HASH(hent->host.addr, newMask);
 971                         SLIST_INSERT_HEAD(&newTab[newBucket], hent, next);
 972                 }
 973         }
 974
 975         /* Replace old table with new one */
 976         if (priv->conf.debugLevel >= 3) {
 977                 log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n",
 978                     ng_bridge_nodename(priv->node),
 979                     priv->numBuckets, newNumBuckets);
 980         }
 981         free(priv->tab, M_NETGRAPH_BRIDGE);
 982         priv->numBuckets = newNumBuckets;
 983         priv->hashMask = newMask;
 984         priv->tab = newTab;
 985         return;
 986 }
 987
 988 /******************************************************************
 989                     MISC FUNCTIONS
 990 ******************************************************************/
 991
 992 /*
 993  * Remove all hosts associated with a specific link from the hashtable.
 994  * If linkNum == -1, then remove all hosts in the table.
 995  */
 996 static void
 997 ng_bridge_remove_hosts(priv_p priv, link_p link)
 998 {
 999         int bucket;
1000
1001         for (bucket = 0; bucket < priv->numBuckets; bucket++) {
1002                 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]);
1003
1004                 while (*hptr != NULL) {
1005                         struct ng_bridge_hent *const hent = *hptr;
1006
1007                         if (link == NULL || hent->host.link == link) {
1008                                 *hptr = SLIST_NEXT(hent, next);
1009                                 free(hent, M_NETGRAPH_BRIDGE);
1010                                 priv->numHosts--;
1011                         } else
1012                                 hptr = &SLIST_NEXT(hent, next);
1013                 }
1014         }
1015 }
1016
1017 /*
1018  * Handle our once-per-second timeout event. We do two things:
1019  * we decrement link->loopCount for those links being muted due to
1020  * a detected loopback condition, and we remove any hosts from
1021  * the hashtable whom we haven't heard from in a long while.
1022  */
1023 static int
1024 ng_bridge_unmute(hook_p hook, void *arg)
1025 {
1026         link_p link = NG_HOOK_PRIVATE(hook);
1027         node_p node = NG_HOOK_NODE(hook);
1028         priv_p priv = NG_NODE_PRIVATE(node);
1029         int *counter = arg;
1030
1031         if (link->loopCount != 0) {
1032                 link->loopCount--;
1033                 if (link->loopCount == 0 && priv->conf.debugLevel >= 2) {
1034                         log(LOG_INFO, "ng_bridge: %s:"
1035                             " restoring looped back %s\n",
1036                             ng_bridge_nodename(node), NG_HOOK_NAME(hook));
1037                 }
1038         }
1039         (*counter)++;
1040         return (1);
1041 }
1042
1043 static void
1044 ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2)
1045 {
1046         const priv_p priv = NG_NODE_PRIVATE(node);
1047         int bucket;
1048         int counter = 0;
1049         hook_p ret;
1050
1051         /* Update host time counters and remove stale entries */
1052         for (bucket = 0; bucket < priv->numBuckets; bucket++) {
1053                 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]);
1054
1055                 while (*hptr != NULL) {
1056                         struct ng_bridge_hent *const hent = *hptr;
1057
1058                         /* Remove hosts we haven't heard from in a while */
1059                         if (++hent->host.staleness >= priv->conf.maxStaleness) {
1060                                 *hptr = SLIST_NEXT(hent, next);
1061                                 free(hent, M_NETGRAPH_BRIDGE);
1062                                 priv->numHosts--;
1063                         } else {
1064                                 if (hent->host.age < 0xffff)
1065                                         hent->host.age++;
1066                                 hptr = &SLIST_NEXT(hent, next);
1067                                 counter++;
1068                         }
1069                 }
1070         }
1071         KASSERT(priv->numHosts == counter,
1072             ("%s: hosts: %d != %d", __func__, priv->numHosts, counter));
1073
1074         /* Decrease table size if necessary */
1075         ng_bridge_rehash(priv);
1076
1077         /* Decrease loop counter on muted looped back links */
1078         counter = 0;
1079         NG_NODE_FOREACH_HOOK(node, ng_bridge_unmute, &counter, ret);
1080         KASSERT(priv->numLinks == counter,
1081             ("%s: links: %d != %d", __func__, priv->numLinks, counter));
1082
1083         /* Register a new timeout, keeping the existing node reference */
1084         ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0);
1085 }
1086
1087 /*
1088  * Return node's "name", even if it doesn't have one.
1089  */
1090 static const char *
1091 ng_bridge_nodename(node_p node)
1092 {
1093         static char name[NG_NODESIZ];
1094
1095         if (NG_NODE_HAS_NAME(node))
1096                 snprintf(name, sizeof(name), "%s", NG_NODE_NAME(node));
1097         else
1098                 snprintf(name, sizeof(name), "[%x]", ng_node2ID(node));
1099         return name;
1100 }