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 #include <sys/types.h>
  69 #include <sys/counter.h>
  70
  71 #include <net/if.h>
  72 #include <net/if_var.h>
  73 #include <net/ethernet.h>
  74 #include <net/vnet.h>
  75
  76 #include <netinet/in.h>
  77 #if 0   /* not used yet */
  78 #include <netinet/ip_fw.h>
  79 #endif
  80 #include <netgraph/ng_message.h>
  81 #include <netgraph/netgraph.h>
  82 #include <netgraph/ng_parse.h>
  83 #include <netgraph/ng_bridge.h>
  84
  85 #ifdef NG_SEPARATE_MALLOC
  86 static MALLOC_DEFINE(M_NETGRAPH_BRIDGE, "netgraph_bridge",
  87     "netgraph bridge node");
  88 #else
  89 #define M_NETGRAPH_BRIDGE M_NETGRAPH
  90 #endif
  91
  92 /* Counter based stats */
  93 struct ng_bridge_link_kernel_stats {
  94         counter_u64_t   recvOctets;     /* total octets rec'd on link */
  95         counter_u64_t   recvPackets;    /* total pkts rec'd on link */
  96         counter_u64_t   recvMulticasts; /* multicast pkts rec'd on link */
  97         counter_u64_t   recvBroadcasts; /* broadcast pkts rec'd on link */
  98         counter_u64_t   recvUnknown;    /* pkts rec'd with unknown dest addr */
  99         counter_u64_t   recvRunts;      /* pkts rec'd less than 14 bytes */
 100         counter_u64_t   recvInvalid;    /* pkts rec'd with bogus source addr */
 101         counter_u64_t   xmitOctets;     /* total octets xmit'd on link */
 102         counter_u64_t   xmitPackets;    /* total pkts xmit'd on link */
 103         counter_u64_t   xmitMulticasts; /* multicast pkts xmit'd on link */
 104         counter_u64_t   xmitBroadcasts; /* broadcast pkts xmit'd on link */
 105         counter_u64_t   loopDrops;      /* pkts dropped due to loopback */
 106         u_int64_t       loopDetects;    /* number of loop detections */
 107         counter_u64_t   memoryFailures; /* times couldn't get mem or mbuf */
 108 };
 109
 110 /* Per-link private data */
 111 struct ng_bridge_link {
 112         hook_p                          hook;           /* netgraph hook */
 113         u_int16_t                       loopCount;      /* loop ignore timer */
 114         unsigned int                    learnMac : 1,   /* autolearn macs */
 115                                         sendUnknown : 1;/* send unknown macs out */
 116         struct ng_bridge_link_kernel_stats stats;       /* link stats */
 117 };
 118 typedef struct ng_bridge_link const *link_cp;   /* read only access */
 119
 120 /* Per-node private data */
 121 struct ng_bridge_private {
 122         struct ng_bridge_bucket *tab;           /* hash table bucket array */
 123         struct ng_bridge_config conf;           /* node configuration */
 124         node_p                  node;           /* netgraph node */
 125         u_int                   numHosts;       /* num entries in table */
 126         u_int                   numBuckets;     /* num buckets in table */
 127         u_int                   hashMask;       /* numBuckets - 1 */
 128         int                     numLinks;       /* num connected links */
 129         unsigned int            persistent : 1, /* can exist w/o hooks */
 130                                 sendUnknown : 1;/* links receive unknowns by default */
 131         struct callout          timer;          /* one second periodic timer */
 132 };
 133 typedef struct ng_bridge_private *priv_p;
 134 typedef struct ng_bridge_private const *priv_cp;        /* read only access */
 135
 136 /* Information about a host, stored in a hash table entry */
 137 struct ng_bridge_host {
 138         u_char          addr[6];        /* ethernet address */
 139         link_p          link;           /* link where addr can be found */
 140         u_int16_t       age;            /* seconds ago entry was created */
 141         u_int16_t       staleness;      /* seconds ago host last heard from */
 142         SLIST_ENTRY(ng_bridge_host)     next;   /* next entry in bucket */
 143 };
 144
 145 /* Hash table bucket declaration */
 146 SLIST_HEAD(ng_bridge_bucket, ng_bridge_host);
 147
 148 /* Netgraph node methods */
 149 static ng_constructor_t ng_bridge_constructor;
 150 static ng_rcvmsg_t      ng_bridge_rcvmsg;
 151 static ng_shutdown_t    ng_bridge_shutdown;
 152 static ng_newhook_t     ng_bridge_newhook;
 153 static ng_rcvdata_t     ng_bridge_rcvdata;
 154 static ng_disconnect_t  ng_bridge_disconnect;
 155
 156 /* Other internal functions */
 157 static void     ng_bridge_free_link(link_p link);
 158 static struct   ng_bridge_host *ng_bridge_get(priv_cp priv, const u_char *addr);
 159 static int      ng_bridge_put(priv_p priv, const u_char *addr, link_p link);
 160 static void     ng_bridge_rehash(priv_p priv);
 161 static void     ng_bridge_remove_hosts(priv_p priv, link_p link);
 162 static void     ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2);
 163 static const    char *ng_bridge_nodename(node_cp node);
 164
 165 /* Ethernet broadcast */
 166 static const u_char ng_bridge_bcast_addr[ETHER_ADDR_LEN] =
 167     { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
 168
 169 /* Compare Ethernet addresses using 32 and 16 bit words instead of bytewise */
 170 #define ETHER_EQUAL(a,b)        (((const u_int32_t *)(a))[0] \
 171                                         == ((const u_int32_t *)(b))[0] \
 172                                     && ((const u_int16_t *)(a))[2] \
 173                                         == ((const u_int16_t *)(b))[2])
 174
 175 /* Minimum and maximum number of hash buckets. Must be a power of two. */
 176 #define MIN_BUCKETS             (1 << 5)        /* 32 */
 177 #define MAX_BUCKETS             (1 << 14)       /* 16384 */
 178
 179 /* Configuration default values */
 180 #define DEFAULT_LOOP_TIMEOUT    60
 181 #define DEFAULT_MAX_STALENESS   (15 * 60)       /* same as ARP timeout */
 182 #define DEFAULT_MIN_STABLE_AGE  1
 183
 184 /******************************************************************
 185                     NETGRAPH PARSE TYPES
 186 ******************************************************************/
 187
 188 /*
 189  * How to determine the length of the table returned by NGM_BRIDGE_GET_TABLE
 190  */
 191 static int
 192 ng_bridge_getTableLength(const struct ng_parse_type *type,
 193         const u_char *start, const u_char *buf)
 194 {
 195         const struct ng_bridge_host_ary *const hary
 196             = (const struct ng_bridge_host_ary *)(buf - sizeof(u_int32_t));
 197
 198         return hary->numHosts;
 199 }
 200
 201 /* Parse type for struct ng_bridge_host_ary */
 202 static const struct ng_parse_struct_field ng_bridge_host_type_fields[]
 203         = NG_BRIDGE_HOST_TYPE_INFO(&ng_parse_enaddr_type);
 204 static const struct ng_parse_type ng_bridge_host_type = {
 205         &ng_parse_struct_type,
 206         &ng_bridge_host_type_fields
 207 };
 208 static const struct ng_parse_array_info ng_bridge_hary_type_info = {
 209         &ng_bridge_host_type,
 210         ng_bridge_getTableLength
 211 };
 212 static const struct ng_parse_type ng_bridge_hary_type = {
 213         &ng_parse_array_type,
 214         &ng_bridge_hary_type_info
 215 };
 216 static const struct ng_parse_struct_field ng_bridge_host_ary_type_fields[]
 217         = NG_BRIDGE_HOST_ARY_TYPE_INFO(&ng_bridge_hary_type);
 218 static const struct ng_parse_type ng_bridge_host_ary_type = {
 219         &ng_parse_struct_type,
 220         &ng_bridge_host_ary_type_fields
 221 };
 222
 223 /* Parse type for struct ng_bridge_config */
 224 static const struct ng_parse_struct_field ng_bridge_config_type_fields[]
 225         = NG_BRIDGE_CONFIG_TYPE_INFO;
 226 static const struct ng_parse_type ng_bridge_config_type = {
 227         &ng_parse_struct_type,
 228         &ng_bridge_config_type_fields
 229 };
 230
 231 /* Parse type for struct ng_bridge_link_stat */
 232 static const struct ng_parse_struct_field ng_bridge_stats_type_fields[]
 233         = NG_BRIDGE_STATS_TYPE_INFO;
 234 static const struct ng_parse_type ng_bridge_stats_type = {
 235         &ng_parse_struct_type,
 236         &ng_bridge_stats_type_fields
 237 };
 238 /* Parse type for struct ng_bridge_move_host */
 239 static const struct ng_parse_struct_field ng_bridge_move_host_type_fields[]
 240         = NG_BRIDGE_MOVE_HOST_TYPE_INFO(&ng_parse_enaddr_type);
 241 static const struct ng_parse_type ng_bridge_move_host_type = {
 242         &ng_parse_struct_type,
 243         &ng_bridge_move_host_type_fields
 244 };
 245
 246 /* List of commands and how to convert arguments to/from ASCII */
 247 static const struct ng_cmdlist ng_bridge_cmdlist[] = {
 248         {
 249           NGM_BRIDGE_COOKIE,
 250           NGM_BRIDGE_SET_CONFIG,
 251           "setconfig",
 252           &ng_bridge_config_type,
 253           NULL
 254         },
 255         {
 256           NGM_BRIDGE_COOKIE,
 257           NGM_BRIDGE_GET_CONFIG,
 258           "getconfig",
 259           NULL,
 260           &ng_bridge_config_type
 261         },
 262         {
 263           NGM_BRIDGE_COOKIE,
 264           NGM_BRIDGE_RESET,
 265           "reset",
 266           NULL,
 267           NULL
 268         },
 269         {
 270           NGM_BRIDGE_COOKIE,
 271           NGM_BRIDGE_GET_STATS,
 272           "getstats",
 273           &ng_parse_uint32_type,
 274           &ng_bridge_stats_type
 275         },
 276         {
 277           NGM_BRIDGE_COOKIE,
 278           NGM_BRIDGE_CLR_STATS,
 279           "clrstats",
 280           &ng_parse_uint32_type,
 281           NULL
 282         },
 283         {
 284           NGM_BRIDGE_COOKIE,
 285           NGM_BRIDGE_GETCLR_STATS,
 286           "getclrstats",
 287           &ng_parse_uint32_type,
 288           &ng_bridge_stats_type
 289         },
 290         {
 291           NGM_BRIDGE_COOKIE,
 292           NGM_BRIDGE_GET_TABLE,
 293           "gettable",
 294           NULL,
 295           &ng_bridge_host_ary_type
 296         },
 297         {
 298           NGM_BRIDGE_COOKIE,
 299           NGM_BRIDGE_SET_PERSISTENT,
 300           "setpersistent",
 301           NULL,
 302           NULL
 303         },
 304         {
 305           NGM_BRIDGE_COOKIE,
 306           NGM_BRIDGE_MOVE_HOST,
 307           "movehost",
 308           &ng_bridge_move_host_type,
 309           NULL
 310         },
 311         { 0 }
 312 };
 313
 314 /* Node type descriptor */
 315 static struct ng_type ng_bridge_typestruct = {
 316         .version =      NG_ABI_VERSION,
 317         .name =         NG_BRIDGE_NODE_TYPE,
 318         .constructor =  ng_bridge_constructor,
 319         .rcvmsg =       ng_bridge_rcvmsg,
 320         .shutdown =     ng_bridge_shutdown,
 321         .newhook =      ng_bridge_newhook,
 322         .rcvdata =      ng_bridge_rcvdata,
 323         .disconnect =   ng_bridge_disconnect,
 324         .cmdlist =      ng_bridge_cmdlist,
 325 };
 326 NETGRAPH_INIT(bridge, &ng_bridge_typestruct);
 327
 328 /******************************************************************
 329                     NETGRAPH NODE METHODS
 330 ******************************************************************/
 331
 332 /*
 333  * Node constructor
 334  */
 335 static int
 336 ng_bridge_constructor(node_p node)
 337 {
 338         priv_p priv;
 339
 340         /* Allocate and initialize private info */
 341         priv = malloc(sizeof(*priv), M_NETGRAPH_BRIDGE, M_WAITOK | M_ZERO);
 342         ng_callout_init(&priv->timer);
 343
 344         /* Allocate and initialize hash table, etc. */
 345         priv->tab = malloc(MIN_BUCKETS * sizeof(*priv->tab),
 346             M_NETGRAPH_BRIDGE, M_WAITOK | M_ZERO);
 347         priv->numBuckets = MIN_BUCKETS;
 348         priv->hashMask = MIN_BUCKETS - 1;
 349         priv->conf.debugLevel = 1;
 350         priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT;
 351         priv->conf.maxStaleness = DEFAULT_MAX_STALENESS;
 352         priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE;
 353         priv->sendUnknown = 1;         /* classic bridge */
 354
 355         NG_NODE_SET_PRIVATE(node, priv);
 356         priv->node = node;
 357
 358         /* Start timer; timer is always running while node is alive */
 359         ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0);
 360
 361         /* Done */
 362         return (0);
 363 }
 364
 365 /*
 366  * Method for attaching a new hook
 367  */
 368 static  int
 369 ng_bridge_newhook(node_p node, hook_p hook, const char *name)
 370 {
 371         const priv_p priv = NG_NODE_PRIVATE(node);
 372         char linkName[NG_HOOKSIZ];
 373         u_int32_t linkNum;
 374         link_p link;
 375         const char *prefix = NG_BRIDGE_HOOK_LINK_PREFIX;
 376         bool isUplink;
 377
 378         /* Check for a link hook */
 379         if (strlen(name) <= strlen(prefix))
 380                 return (EINVAL);       /* Unknown hook name */
 381
 382         isUplink = (name[0] == 'u');
 383         if (isUplink)
 384                 prefix = NG_BRIDGE_HOOK_UPLINK_PREFIX;
 385
 386         /* primitive parsing */
 387         linkNum = strtoul(name + strlen(prefix), NULL, 10);
 388         /* validation by comparing against the reconstucted name  */
 389         snprintf(linkName, sizeof(linkName), "%s%u", prefix, linkNum);
 390         if (strcmp(linkName, name) != 0)
 391                 return (EINVAL);
 392
 393         if (linkNum == 0 && isUplink)
 394                 return (EINVAL);
 395
 396         if(NG_PEER_NODE(hook) == node)
 397                 return (ELOOP);
 398
 399         link = malloc(sizeof(*link), M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO);
 400         if (link == NULL)
 401                 return (ENOMEM);
 402
 403 #define NG_BRIDGE_COUNTER_ALLOC(f) do {                 \
 404         link->stats.f = counter_u64_alloc(M_NOWAIT);    \
 405         if (link->stats.f == NULL)                      \
 406                 goto nomem;                             \
 407 } while (0)
 408         NG_BRIDGE_COUNTER_ALLOC(recvOctets);
 409         NG_BRIDGE_COUNTER_ALLOC(recvPackets);
 410         NG_BRIDGE_COUNTER_ALLOC(recvMulticasts);
 411         NG_BRIDGE_COUNTER_ALLOC(recvBroadcasts);
 412         NG_BRIDGE_COUNTER_ALLOC(recvUnknown);
 413         NG_BRIDGE_COUNTER_ALLOC(recvRunts);
 414         NG_BRIDGE_COUNTER_ALLOC(recvInvalid);
 415         NG_BRIDGE_COUNTER_ALLOC(xmitOctets);
 416         NG_BRIDGE_COUNTER_ALLOC(xmitPackets);
 417         NG_BRIDGE_COUNTER_ALLOC(xmitMulticasts);
 418         NG_BRIDGE_COUNTER_ALLOC(xmitBroadcasts);
 419         NG_BRIDGE_COUNTER_ALLOC(loopDrops);
 420         NG_BRIDGE_COUNTER_ALLOC(memoryFailures);
 421 #undef NG_BRIDGE_COUNTER_ALLOC
 422
 423         link->hook = hook;
 424         if (isUplink) {
 425                 link->learnMac = 0;
 426                 link->sendUnknown = 1;
 427                 if (priv->numLinks == 0)        /* if the first link is an uplink */
 428                         priv->sendUnknown = 0;  /* switch to restrictive mode */
 429         } else {
 430                 link->learnMac = 1;
 431                 link->sendUnknown = priv->sendUnknown;
 432         }
 433
 434         NG_HOOK_SET_PRIVATE(hook, link);
 435         priv->numLinks++;
 436         return (0);
 437
 438 nomem:
 439         ng_bridge_free_link(link);
 440         return (ENOMEM);
 441 }
 442
 443 /*
 444  * Receive a control message
 445  */
 446 static void
 447 ng_bridge_clear_link_stats(struct ng_bridge_link_kernel_stats *p)
 448 {
 449         counter_u64_zero(p->recvOctets);
 450         counter_u64_zero(p->recvPackets);
 451         counter_u64_zero(p->recvMulticasts);
 452         counter_u64_zero(p->recvBroadcasts);
 453         counter_u64_zero(p->recvUnknown);
 454         counter_u64_zero(p->recvRunts);
 455         counter_u64_zero(p->recvInvalid);
 456         counter_u64_zero(p->xmitOctets);
 457         counter_u64_zero(p->xmitPackets);
 458         counter_u64_zero(p->xmitMulticasts);
 459         counter_u64_zero(p->xmitBroadcasts);
 460         counter_u64_zero(p->loopDrops);
 461         p->loopDetects = 0;
 462         counter_u64_zero(p->memoryFailures);
 463 }
 464
 465 static void
 466 ng_bridge_free_link(link_p link)
 467 {
 468         counter_u64_free(link->stats.recvOctets);
 469         counter_u64_free(link->stats.recvPackets);
 470         counter_u64_free(link->stats.recvMulticasts);
 471         counter_u64_free(link->stats.recvBroadcasts);
 472         counter_u64_free(link->stats.recvUnknown);
 473         counter_u64_free(link->stats.recvRunts);
 474         counter_u64_free(link->stats.recvInvalid);
 475         counter_u64_free(link->stats.xmitOctets);
 476         counter_u64_free(link->stats.xmitPackets);
 477         counter_u64_free(link->stats.xmitMulticasts);
 478         counter_u64_free(link->stats.xmitBroadcasts);
 479         counter_u64_free(link->stats.loopDrops);
 480         counter_u64_free(link->stats.memoryFailures);
 481         free(link, M_NETGRAPH_BRIDGE);
 482 }
 483
 484 static int
 485 ng_bridge_reset_link(hook_p hook, void *arg __unused)
 486 {
 487         link_p priv = NG_HOOK_PRIVATE(hook);
 488
 489         priv->loopCount = 0;
 490         ng_bridge_clear_link_stats(&priv->stats);
 491         return (1);
 492 }
 493
 494 static int
 495 ng_bridge_rcvmsg(node_p node, item_p item, hook_p lasthook)
 496 {
 497         const priv_p priv = NG_NODE_PRIVATE(node);
 498         struct ng_mesg *resp = NULL;
 499         int error = 0;
 500         struct ng_mesg *msg;
 501
 502         NGI_GET_MSG(item, msg);
 503         switch (msg->header.typecookie) {
 504 #ifdef NGM_BRIDGE_TABLE_ABI
 505         case NGM_BRIDGE_COOKIE_TBL:
 506                 switch (msg->header.cmd) {
 507                 case NGM_BRIDGE_GET_CONFIG:
 508                     {
 509                         struct ng_bridge_config_tbl *conf;
 510
 511                         NG_MKRESPONSE(resp, msg, sizeof(*conf),
 512                             M_NOWAIT|M_ZERO);
 513                         if (resp == NULL) {
 514                                 error = ENOMEM;
 515                                 break;
 516                         }
 517                         conf = (struct ng_bridge_config_tbl *)resp->data;
 518                         conf->cfg = priv->conf;
 519                         break;
 520                     }
 521                 case NGM_BRIDGE_SET_CONFIG:
 522                     {
 523                         struct ng_bridge_config_tbl *conf;
 524
 525                         if (msg->header.arglen != sizeof(*conf)) {
 526                                 error = EINVAL;
 527                                 break;
 528                         }
 529                         conf = (struct ng_bridge_config_tbl *)msg->data;
 530                         priv->conf = conf->cfg;
 531                         break;
 532                     }
 533                 case NGM_BRIDGE_GET_TABLE:
 534                     {
 535                         struct ng_bridge_host_tbl_ary *ary;
 536                         struct ng_bridge_hent *hent;
 537                         int i, bucket;
 538
 539                         NG_MKRESPONSE(resp, msg, sizeof(*ary) +
 540                             (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT);
 541                         if (resp == NULL) {
 542                                 error = ENOMEM;
 543                                 break;
 544                         }
 545                         ary = (struct ng_bridge_host_tbl_ary *)resp->data;
 546                         ary->numHosts = priv->numHosts;
 547                         i = 0;
 548                         for (bucket = 0; bucket < priv->numBuckets; bucket++) {
 549                                 SLIST_FOREACH(hent, &priv->tab[bucket], next) {
 550                                         const char *name = NG_HOOK_NAME(hent->host.link->hook);
 551                                         const char *prefix = name[0] == 'u' ?
 552                                             NG_BRIDGE_HOOK_UPLINK_PREFIX :
 553                                             NG_BRIDGE_HOOK_LINK_PREFIX;
 554
 555                                         memcpy(ary->hosts[i].addr,
 556                                             hent->host.addr,
 557                                             sizeof(ary->hosts[i].addr));
 558                                         ary->hosts[i].age = hent->host.age;
 559                                         ary->hosts[i].staleness =
 560                                              hent->host.staleness;
 561                                         ary->hosts[i].linkNum = strtol(
 562                                             name + strlen(prefix), NULL, 10);
 563                                         i++;
 564                                 }
 565                         }
 566                         break;
 567                     }
 568                 }
 569                 /* If already handled break, otherwise use new ABI. */
 570                 if (resp != NULL || error != 0)
 571                     break;
 572 #endif /* NGM_BRIDGE_TABLE_ABI */
 573         case NGM_BRIDGE_COOKIE:
 574                 switch (msg->header.cmd) {
 575                 case NGM_BRIDGE_GET_CONFIG:
 576                     {
 577                         struct ng_bridge_config *conf;
 578
 579                         NG_MKRESPONSE(resp, msg,
 580                             sizeof(struct ng_bridge_config), M_NOWAIT);
 581                         if (resp == NULL) {
 582                                 error = ENOMEM;
 583                                 break;
 584                         }
 585                         conf = (struct ng_bridge_config *)resp->data;
 586                         *conf = priv->conf;     /* no sanity checking needed */
 587                         break;
 588                     }
 589                 case NGM_BRIDGE_SET_CONFIG:
 590                     {
 591                         struct ng_bridge_config *conf;
 592
 593                         if (msg->header.arglen
 594                             != sizeof(struct ng_bridge_config)) {
 595                                 error = EINVAL;
 596                                 break;
 597                         }
 598                         conf = (struct ng_bridge_config *)msg->data;
 599                         priv->conf = *conf;
 600                         break;
 601                     }
 602                 case NGM_BRIDGE_RESET:
 603                     {
 604                         hook_p rethook;
 605
 606                         /* Flush all entries in the hash table */
 607                         ng_bridge_remove_hosts(priv, NULL);
 608
 609                         /* Reset all loop detection counters and stats */
 610                         NG_NODE_FOREACH_HOOK(node, ng_bridge_reset_link, NULL,
 611                             rethook);
 612                         break;
 613                     }
 614                 case NGM_BRIDGE_GET_STATS:
 615                 case NGM_BRIDGE_CLR_STATS:
 616                 case NGM_BRIDGE_GETCLR_STATS:
 617                     {
 618                         hook_p hook;
 619                         link_p link;
 620                         char linkName[NG_HOOKSIZ];
 621                         int linkNum;
 622
 623                         /* Get link number */
 624                         if (msg->header.arglen != sizeof(u_int32_t)) {
 625                                 error = EINVAL;
 626                                 break;
 627                         }
 628                         linkNum = *((int32_t *)msg->data);
 629                         if (linkNum < 0)
 630                                 snprintf(linkName, sizeof(linkName),
 631                                     "%s%u", NG_BRIDGE_HOOK_UPLINK_PREFIX, -linkNum);
 632                         else
 633                                 snprintf(linkName, sizeof(linkName),
 634                                     "%s%u", NG_BRIDGE_HOOK_LINK_PREFIX, linkNum);
 635
 636                         if ((hook = ng_findhook(node, linkName)) == NULL) {
 637                                 error = ENOTCONN;
 638                                 break;
 639                         }
 640                         link = NG_HOOK_PRIVATE(hook);
 641
 642                         /* Get/clear stats */
 643                         if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) {
 644                                 struct ng_bridge_link_stats *rs;
 645
 646                                 NG_MKRESPONSE(resp, msg,
 647                                     sizeof(link->stats), M_NOWAIT);
 648                                 if (resp == NULL) {
 649                                         error = ENOMEM;
 650                                         break;
 651                                 }
 652                                 rs = (struct ng_bridge_link_stats *)resp->data;
 653 #define FETCH(x)        rs->x = counter_u64_fetch(link->stats.x)
 654                                 FETCH(recvOctets);
 655                                 FETCH(recvPackets);
 656                                 FETCH(recvMulticasts);
 657                                 FETCH(recvBroadcasts);
 658                                 FETCH(recvUnknown);
 659                                 FETCH(recvRunts);
 660                                 FETCH(recvInvalid);
 661                                 FETCH(xmitOctets);
 662                                 FETCH(xmitPackets);
 663                                 FETCH(xmitMulticasts);
 664                                 FETCH(xmitBroadcasts);
 665                                 FETCH(loopDrops);
 666                                 rs->loopDetects = link->stats.loopDetects;
 667                                 FETCH(memoryFailures);
 668 #undef FETCH
 669                         }
 670                         if (msg->header.cmd != NGM_BRIDGE_GET_STATS)
 671                                 ng_bridge_clear_link_stats(&link->stats);
 672                         break;
 673                     }
 674                 case NGM_BRIDGE_GET_TABLE:
 675                     {
 676                         struct ng_bridge_host_ary *ary;
 677                         struct ng_bridge_host *host;
 678                         int i = 0, bucket;
 679
 680                         NG_MKRESPONSE(resp, msg, sizeof(*ary)
 681                             + (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT);
 682                         if (resp == NULL) {
 683                                 error = ENOMEM;
 684                                 break;
 685                         }
 686                         ary = (struct ng_bridge_host_ary *)resp->data;
 687                         ary->numHosts = priv->numHosts;
 688                         for (bucket = 0; bucket < priv->numBuckets; bucket++) {
 689                                 SLIST_FOREACH(host, &priv->tab[bucket], next) {
 690                                         memcpy(ary->hosts[i].addr,
 691                                                host->addr,
 692                                                sizeof(ary->hosts[i].addr));
 693                                         ary->hosts[i].age       = host->age;
 694                                         ary->hosts[i].staleness = host->staleness;
 695                                         strncpy(ary->hosts[i].hook,
 696                                                 NG_HOOK_NAME(host->link->hook),
 697                                                 sizeof(ary->hosts[i].hook));
 698                                         i++;
 699                                 }
 700                         }
 701                         break;
 702                     }
 703                 case NGM_BRIDGE_SET_PERSISTENT:
 704                     {
 705                         priv->persistent = 1;
 706                         break;
 707                     }
 708                 case NGM_BRIDGE_MOVE_HOST:
 709                 {
 710                         struct ng_bridge_move_host *mh;
 711                         hook_p hook;
 712
 713                         if (msg->header.arglen < sizeof(*mh)) {
 714                                 error = EINVAL;
 715                                 break;
 716                         }
 717                         mh = (struct ng_bridge_move_host *)msg->data;
 718                         hook = (mh->hook[0] == 0)
 719                             ? lasthook
 720                             : ng_findhook(node, mh->hook);
 721                         if (hook == NULL) {
 722                                 error = ENOENT;
 723                                 break;
 724                         }
 725                         error = ng_bridge_put(priv, mh->addr, NG_HOOK_PRIVATE(hook));
 726                         break;
 727                 }
 728                 default:
 729                         error = EINVAL;
 730                         break;
 731                 }
 732                 break;
 733         default:
 734                 error = EINVAL;
 735                 break;
 736         }
 737
 738         /* Done */
 739         NG_RESPOND_MSG(error, node, item, resp);
 740         NG_FREE_MSG(msg);
 741         return (error);
 742 }
 743
 744 /*
 745  * Receive data on a hook
 746  */
 747 struct ng_bridge_send_ctx {
 748         link_p foundFirst, incoming;
 749         struct mbuf * m;
 750         int manycast, error;
 751 };
 752
 753 /*
 754  * Update stats and send out
 755  */
 756 static inline int
 757 ng_bridge_send_data(link_cp dst, int manycast, struct mbuf *m, item_p item) {
 758         int error = 0;
 759         size_t len = m->m_pkthdr.len;
 760
 761         if(item != NULL)
 762                 NG_FWD_NEW_DATA(error, item, dst->hook, m);
 763         else
 764                 NG_SEND_DATA_ONLY(error, dst->hook, m);
 765
 766         if (error) {
 767                 /* The packet is still ours */
 768                 if (item != NULL)
 769                         NG_FREE_ITEM(item);
 770                 if (m != NULL)
 771                         NG_FREE_M(m);
 772                 return (error);
 773         }
 774
 775         counter_u64_add(dst->stats.xmitPackets, 1);
 776         counter_u64_add(dst->stats.xmitOctets, len);
 777         switch (manycast) {
 778         default:                       /* unknown unicast */
 779                 break;
 780         case 1:                        /* multicast */
 781                 counter_u64_add(dst->stats.xmitMulticasts, 1);
 782                 break;
 783         case 2:                        /* broadcast */
 784                 counter_u64_add(dst->stats.xmitBroadcasts, 1);
 785                 break;
 786         }
 787         return (0);
 788 }
 789
 790 /*
 791  * Loop body for sending to multiple destinations
 792  * return 0 to stop looping
 793  */
 794 static int
 795 ng_bridge_send_ctx(hook_p dst, void *arg)
 796 {
 797         struct ng_bridge_send_ctx *ctx = arg;
 798         link_p destLink = NG_HOOK_PRIVATE(dst);
 799         struct mbuf *m2 = NULL;
 800         int error = 0;
 801
 802         /* Skip incoming link */
 803         if (destLink == ctx->incoming) {
 804                 return (1);
 805         }
 806
 807         /* Skip sending unknowns to undesired links  */
 808         if (!ctx->manycast && !destLink->sendUnknown)
 809                 return (1);
 810
 811         if (ctx->foundFirst == NULL) {
 812                 /*
 813                  * This is the first usable link we have found.
 814                  * Reserve it for the originals.
 815                  * If we never find another we save a copy.
 816                  */
 817                 ctx->foundFirst = destLink;
 818                 return (1);
 819         }
 820
 821         /*
 822          * It's usable link but not the reserved (first) one.
 823          * Copy mbuf info for sending.
 824          */
 825         m2 = m_dup(ctx->m, M_NOWAIT);
 826         if (m2 == NULL) {
 827                 counter_u64_add(ctx->incoming->stats.memoryFailures, 1);
 828                 ctx->error = ENOBUFS;
 829                 return (0);            /* abort loop, do not try again and again */
 830         }
 831
 832         /* Send packet */
 833         error = ng_bridge_send_data(destLink, ctx->manycast, m2, NULL);
 834         if (error)
 835           ctx->error = error;
 836         return (1);
 837 }
 838
 839 static int
 840 ng_bridge_rcvdata(hook_p hook, item_p item)
 841 {
 842         const node_p node = NG_HOOK_NODE(hook);
 843         const priv_p priv = NG_NODE_PRIVATE(node);
 844         struct ng_bridge_host *host;
 845         struct ether_header *eh;
 846         struct ng_bridge_send_ctx ctx = { 0 };
 847         hook_p ret;
 848
 849         NGI_GET_M(item, ctx.m);
 850
 851         ctx.incoming = NG_HOOK_PRIVATE(hook);
 852         /* Sanity check packet and pull up header */
 853         if (ctx.m->m_pkthdr.len < ETHER_HDR_LEN) {
 854                 counter_u64_add(ctx.incoming->stats.recvRunts, 1);
 855                 NG_FREE_ITEM(item);
 856                 NG_FREE_M(ctx.m);
 857                 return (EINVAL);
 858         }
 859         if (ctx.m->m_len < ETHER_HDR_LEN && !(ctx.m = m_pullup(ctx.m, ETHER_HDR_LEN))) {
 860                 counter_u64_add(ctx.incoming->stats.memoryFailures, 1);
 861                 NG_FREE_ITEM(item);
 862                 return (ENOBUFS);
 863         }
 864         eh = mtod(ctx.m, struct ether_header *);
 865         if ((eh->ether_shost[0] & 1) != 0) {
 866                 counter_u64_add(ctx.incoming->stats.recvInvalid, 1);
 867                 NG_FREE_ITEM(item);
 868                 NG_FREE_M(ctx.m);
 869                 return (EINVAL);
 870         }
 871
 872         /* Is link disabled due to a loopback condition? */
 873         if (ctx.incoming->loopCount != 0) {
 874                 counter_u64_add(ctx.incoming->stats.loopDrops, 1);
 875                 NG_FREE_ITEM(item);
 876                 NG_FREE_M(ctx.m);
 877                 return (ELOOP);
 878         }
 879
 880         /* Update stats */
 881         counter_u64_add(ctx.incoming->stats.recvPackets, 1);
 882         counter_u64_add(ctx.incoming->stats.recvOctets, ctx.m->m_pkthdr.len);
 883         if ((ctx.manycast = (eh->ether_dhost[0] & 1)) != 0) {
 884                 if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) {
 885                         counter_u64_add(ctx.incoming->stats.recvBroadcasts, 1);
 886                         ctx.manycast = 2;
 887                 } else
 888                         counter_u64_add(ctx.incoming->stats.recvMulticasts, 1);
 889         }
 890
 891         /* Look up packet's source Ethernet address in hashtable */
 892         if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL)
 893                 /* Update time since last heard from this host.
 894                  * This is safe without locking, because it's
 895                  * the only operation during shared access.
 896                  */
 897                 if (__predict_false(host->staleness > 0))
 898                         host->staleness = 0;
 899
 900         if ((host == NULL && ctx.incoming->learnMac) ||
 901             (host != NULL && host->link != ctx.incoming)) {
 902                 struct ng_mesg *msg;
 903                 struct ng_bridge_move_host *mh;
 904                 int error = 0;
 905
 906                 NG_MKMESSAGE(msg, NGM_BRIDGE_COOKIE, NGM_BRIDGE_MOVE_HOST,
 907                     sizeof(*mh), M_NOWAIT);
 908                 if (msg == NULL) {
 909                         counter_u64_add(ctx.incoming->stats.memoryFailures, 1);
 910                         NG_FREE_ITEM(item);
 911                         NG_FREE_M(ctx.m);
 912                         return (ENOMEM);
 913                 }
 914                 mh = (struct ng_bridge_move_host *)msg->data;
 915                 strncpy(mh->hook, NG_HOOK_NAME(ctx.incoming->hook),
 916                     sizeof(mh->hook));
 917                 memcpy(mh->addr, eh->ether_shost, sizeof(mh->addr));
 918                 NG_SEND_MSG_ID(error, node, msg, NG_NODE_ID(node),
 919                     NG_NODE_ID(node));
 920                 if (error)
 921                         counter_u64_add(ctx.incoming->stats.memoryFailures, 1);
 922         }
 923
 924         if (host != NULL && host->link != ctx.incoming) {
 925                 if (host->age < priv->conf.minStableAge) {
 926                         /* Drop packet on instable links */
 927                         counter_u64_add(ctx.incoming->stats.loopDrops, 1);
 928                         NG_FREE_ITEM(item);
 929                         NG_FREE_M(ctx.m);
 930                         return (ELOOP);
 931                 }
 932         }
 933
 934         /* Run packet through ipfw processing, if enabled */
 935 #if 0
 936         if (priv->conf.ipfw[linkNum] && V_fw_enable && V_ip_fw_chk_ptr != NULL) {
 937                 /* XXX not implemented yet */
 938         }
 939 #endif
 940
 941         /*
 942          * If unicast and destination host known, deliver to host's link,
 943          * unless it is the same link as the packet came in on.
 944          */
 945         if (!ctx.manycast) {
 946                 /* Determine packet destination link */
 947                 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) {
 948                         link_p destLink = host->link;
 949
 950                         /* If destination same as incoming link, do nothing */
 951                         if (destLink == ctx.incoming) {
 952                                 NG_FREE_ITEM(item);
 953                                 NG_FREE_M(ctx.m);
 954                                 return (0);
 955                         }
 956
 957                         /* Deliver packet out the destination link */
 958                         return (ng_bridge_send_data(destLink, ctx.manycast, ctx.m, item));
 959                 }
 960
 961                 /* Destination host is not known */
 962                 counter_u64_add(ctx.incoming->stats.recvUnknown, 1);
 963         }
 964
 965         /* Distribute unknown, multicast, broadcast pkts to all other links */
 966         NG_NODE_FOREACH_HOOK(node, ng_bridge_send_ctx, &ctx, ret);
 967
 968         /* Finally send out on the first link found */
 969         if (ctx.foundFirst != NULL) {
 970                 int error = ng_bridge_send_data(ctx.foundFirst, ctx.manycast, ctx.m, item);
 971                 if (error)
 972                         ctx.error = error;
 973         } else {                       /* nothing to send at all */
 974                 NG_FREE_ITEM(item);
 975                 NG_FREE_M(ctx.m);
 976         }
 977
 978         return (ctx.error);
 979 }
 980
 981 /*
 982  * Shutdown node
 983  */
 984 static int
 985 ng_bridge_shutdown(node_p node)
 986 {
 987         const priv_p priv = NG_NODE_PRIVATE(node);
 988
 989         /*
 990          * Shut down everything including the timer.  Even if the
 991          * callout has already been dequeued and is about to be
 992          * run, ng_bridge_timeout() won't be fired as the node
 993          * is already marked NGF_INVALID, so we're safe to free
 994          * the node now.
 995          */
 996         KASSERT(priv->numLinks == 0 && priv->numHosts == 0,
 997             ("%s: numLinks=%d numHosts=%d",
 998             __func__, priv->numLinks, priv->numHosts));
 999         ng_uncallout(&priv->timer, node);
1000         NG_NODE_SET_PRIVATE(node, NULL);
1001         NG_NODE_UNREF(node);
1002         free(priv->tab, M_NETGRAPH_BRIDGE);
1003         free(priv, M_NETGRAPH_BRIDGE);
1004         return (0);
1005 }
1006
1007 /*
1008  * Hook disconnection.
1009  */
1010 static int
1011 ng_bridge_disconnect(hook_p hook)
1012 {
1013         const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
1014         link_p link = NG_HOOK_PRIVATE(hook);
1015
1016         /* Remove all hosts associated with this link */
1017         ng_bridge_remove_hosts(priv, link);
1018
1019         /* Free associated link information */
1020         ng_bridge_free_link(link);
1021         priv->numLinks--;
1022
1023         /* If no more hooks, go away */
1024         if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
1025             && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))
1026             && !priv->persistent) {
1027                 ng_rmnode_self(NG_HOOK_NODE(hook));
1028         }
1029         return (0);
1030 }
1031
1032 /******************************************************************
1033                     HASH TABLE FUNCTIONS
1034 ******************************************************************/
1035
1036 /*
1037  * Hash algorithm
1038  */
1039 #define HASH(addr,mask)         ( (((const u_int16_t *)(addr))[0]       \
1040                                  ^ ((const u_int16_t *)(addr))[1]       \
1041                                  ^ ((const u_int16_t *)(addr))[2]) & (mask) )
1042
1043 /*
1044  * Find a host entry in the table.
1045  */
1046 static struct ng_bridge_host *
1047 ng_bridge_get(priv_cp priv, const u_char *addr)
1048 {
1049         const int bucket = HASH(addr, priv->hashMask);
1050         struct ng_bridge_host *host;
1051
1052         SLIST_FOREACH(host, &priv->tab[bucket], next) {
1053                 if (ETHER_EQUAL(host->addr, addr))
1054                         return (host);
1055         }
1056         return (NULL);
1057 }
1058
1059 /*
1060  * Add a host entry to the table. If it already exists, move it
1061  * to the new link. Returns 0 on success.
1062  */
1063 static int
1064 ng_bridge_put(priv_p priv, const u_char *addr, link_p link)
1065 {
1066         const int bucket = HASH(addr, priv->hashMask);
1067         struct ng_bridge_host *host;
1068
1069         if ((host = ng_bridge_get(priv, addr)) != NULL) {
1070                 /* Host already on the correct link? */
1071                 if (host->link == link)
1072                         return 0;
1073
1074                 /* Move old host over to new link */
1075                 if (host->age >= priv->conf.minStableAge) {
1076                         host->link = link;
1077                         host->age = 0;
1078                         return (0);
1079                 }
1080                 /*
1081                  * If the host was recently moved to the old link and
1082                  * it's now jumping to a new link, declare a loopback
1083                  * condition.
1084                  */
1085                 if (priv->conf.debugLevel >= 2)
1086                     log(LOG_WARNING, "ng_bridge: %s:"
1087                         " loopback detected on %s\n",
1088                         ng_bridge_nodename(priv->node),
1089                         NG_HOOK_NAME(link->hook));
1090
1091                 /* Mark link as linka non grata */
1092                 link->loopCount = priv->conf.loopTimeout;
1093                 link->stats.loopDetects++;
1094
1095                 /* Forget all hosts on this link */
1096                 ng_bridge_remove_hosts(priv, link);
1097                 return (ELOOP);
1098         }
1099
1100         /* Allocate and initialize new hashtable entry */
1101         host = malloc(sizeof(*host), M_NETGRAPH_BRIDGE, M_NOWAIT);
1102         if (host == NULL)
1103                 return (ENOMEM);
1104         bcopy(addr, host->addr, ETHER_ADDR_LEN);
1105         host->link = link;
1106         host->staleness = 0;
1107         host->age = 0;
1108
1109         /* Add new element to hash bucket */
1110         SLIST_INSERT_HEAD(&priv->tab[bucket], host, next);
1111         priv->numHosts++;
1112
1113         /* Resize table if necessary */
1114         ng_bridge_rehash(priv);
1115         return (0);
1116 }
1117
1118 /*
1119  * Resize the hash table. We try to maintain the number of buckets
1120  * such that the load factor is in the range 0.25 to 1.0.
1121  *
1122  * If we can't get the new memory then we silently fail. This is OK
1123  * because things will still work and we'll try again soon anyway.
1124  */
1125 static void
1126 ng_bridge_rehash(priv_p priv)
1127 {
1128         struct ng_bridge_bucket *newTab;
1129         int oldBucket, newBucket;
1130         int newNumBuckets;
1131         u_int newMask;
1132
1133         /* Is table too full or too empty? */
1134         if (priv->numHosts > priv->numBuckets
1135             && (priv->numBuckets << 1) <= MAX_BUCKETS)
1136                 newNumBuckets = priv->numBuckets << 1;
1137         else if (priv->numHosts < (priv->numBuckets >> 2)
1138             && (priv->numBuckets >> 2) >= MIN_BUCKETS)
1139                 newNumBuckets = priv->numBuckets >> 2;
1140         else
1141                 return;
1142         newMask = newNumBuckets - 1;
1143
1144         /* Allocate and initialize new table */
1145         newTab = malloc(newNumBuckets * sizeof(*newTab),
1146             M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO);
1147         if (newTab == NULL)
1148                 return;
1149
1150         /* Move all entries from old table to new table */
1151         for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) {
1152                 struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket];
1153
1154                 while (!SLIST_EMPTY(oldList)) {
1155                         struct ng_bridge_host *const host
1156                             = SLIST_FIRST(oldList);
1157
1158                         SLIST_REMOVE_HEAD(oldList, next);
1159                         newBucket = HASH(host->addr, newMask);
1160                         SLIST_INSERT_HEAD(&newTab[newBucket], host, next);
1161                 }
1162         }
1163
1164         /* Replace old table with new one */
1165         if (priv->conf.debugLevel >= 3) {
1166                 log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n",
1167                     ng_bridge_nodename(priv->node),
1168                     priv->numBuckets, newNumBuckets);
1169         }
1170         free(priv->tab, M_NETGRAPH_BRIDGE);
1171         priv->numBuckets = newNumBuckets;
1172         priv->hashMask = newMask;
1173         priv->tab = newTab;
1174         return;
1175 }
1176
1177 /******************************************************************
1178                     MISC FUNCTIONS
1179 ******************************************************************/
1180
1181 /*
1182  * Remove all hosts associated with a specific link from the hashtable.
1183  * If linkNum == -1, then remove all hosts in the table.
1184  */
1185 static void
1186 ng_bridge_remove_hosts(priv_p priv, link_p link)
1187 {
1188         int bucket;
1189
1190         for (bucket = 0; bucket < priv->numBuckets; bucket++) {
1191                 struct ng_bridge_host **hptr = &SLIST_FIRST(&priv->tab[bucket]);
1192
1193                 while (*hptr != NULL) {
1194                         struct ng_bridge_host *const host = *hptr;
1195
1196                         if (link == NULL || host->link == link) {
1197                                 *hptr = SLIST_NEXT(host, next);
1198                                 free(host, M_NETGRAPH_BRIDGE);
1199                                 priv->numHosts--;
1200                         } else
1201                                 hptr = &SLIST_NEXT(host, next);
1202                 }
1203         }
1204 }
1205
1206 /*
1207  * Handle our once-per-second timeout event. We do two things:
1208  * we decrement link->loopCount for those links being muted due to
1209  * a detected loopback condition, and we remove any hosts from
1210  * the hashtable whom we haven't heard from in a long while.
1211  */
1212 static int
1213 ng_bridge_unmute(hook_p hook, void *arg)
1214 {
1215         link_p link = NG_HOOK_PRIVATE(hook);
1216         node_p node = NG_HOOK_NODE(hook);
1217         priv_p priv = NG_NODE_PRIVATE(node);
1218         int *counter = arg;
1219
1220         if (link->loopCount != 0) {
1221                 link->loopCount--;
1222                 if (link->loopCount == 0 && priv->conf.debugLevel >= 2) {
1223                         log(LOG_INFO, "ng_bridge: %s:"
1224                             " restoring looped back %s\n",
1225                             ng_bridge_nodename(node), NG_HOOK_NAME(hook));
1226                 }
1227         }
1228         (*counter)++;
1229         return (1);
1230 }
1231
1232 static void
1233 ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2)
1234 {
1235         const priv_p priv = NG_NODE_PRIVATE(node);
1236         int bucket;
1237         int counter = 0;
1238         hook_p ret;
1239
1240         /* Update host time counters and remove stale entries */
1241         for (bucket = 0; bucket < priv->numBuckets; bucket++) {
1242                 struct ng_bridge_host **hptr = &SLIST_FIRST(&priv->tab[bucket]);
1243
1244                 while (*hptr != NULL) {
1245                         struct ng_bridge_host *const host = *hptr;
1246
1247                         /* Remove hosts we haven't heard from in a while */
1248                         if (++host->staleness >= priv->conf.maxStaleness) {
1249                                 *hptr = SLIST_NEXT(host, next);
1250                                 free(host, M_NETGRAPH_BRIDGE);
1251                                 priv->numHosts--;
1252                         } else {
1253                                 if (host->age < 0xffff)
1254                                         host->age++;
1255                                 hptr = &SLIST_NEXT(host, next);
1256                                 counter++;
1257                         }
1258                 }
1259         }
1260         KASSERT(priv->numHosts == counter,
1261             ("%s: hosts: %d != %d", __func__, priv->numHosts, counter));
1262
1263         /* Decrease table size if necessary */
1264         ng_bridge_rehash(priv);
1265
1266         /* Decrease loop counter on muted looped back links */
1267         counter = 0;
1268         NG_NODE_FOREACH_HOOK(node, ng_bridge_unmute, &counter, ret);
1269         KASSERT(priv->numLinks == counter,
1270             ("%s: links: %d != %d", __func__, priv->numLinks, counter));
1271
1272         /* Register a new timeout, keeping the existing node reference */
1273         ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0);
1274 }
1275
1276 /*
1277  * Return node's "name", even if it doesn't have one.
1278  */
1279 static const char *
1280 ng_bridge_nodename(node_cp node)
1281 {
1282         static char name[NG_NODESIZ];
1283
1284         if (NG_NODE_HAS_NAME(node))
1285                 snprintf(name, sizeof(name), "%s", NG_NODE_NAME(node));
1286         else
1287                 snprintf(name, sizeof(name), "[%x]", ng_node2ID(node));
1288         return name;
1289 }