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         counter_u64_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_hent {
 138         struct ng_bridge_host           host;   /* actual host info */
 139         SLIST_ENTRY(ng_bridge_hent)     next;   /* next entry in bucket */
 140 };
 141
 142 /* Hash table bucket declaration */
 143 SLIST_HEAD(ng_bridge_bucket, ng_bridge_hent);
 144
 145 /* Netgraph node methods */
 146 static ng_constructor_t ng_bridge_constructor;
 147 static ng_rcvmsg_t      ng_bridge_rcvmsg;
 148 static ng_shutdown_t    ng_bridge_shutdown;
 149 static ng_newhook_t     ng_bridge_newhook;
 150 static ng_rcvdata_t     ng_bridge_rcvdata;
 151 static ng_disconnect_t  ng_bridge_disconnect;
 152
 153 /* Other internal functions */
 154 static struct   ng_bridge_host *ng_bridge_get(priv_cp priv, const u_char *addr);
 155 static int      ng_bridge_put(priv_p priv, const u_char *addr, link_p link);
 156 static void     ng_bridge_rehash(priv_p priv);
 157 static void     ng_bridge_remove_hosts(priv_p priv, link_p link);
 158 static void     ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2);
 159 static const    char *ng_bridge_nodename(node_cp node);
 160
 161 /* Ethernet broadcast */
 162 static const u_char ng_bridge_bcast_addr[ETHER_ADDR_LEN] =
 163     { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
 164
 165 /* Compare Ethernet addresses using 32 and 16 bit words instead of bytewise */
 166 #define ETHER_EQUAL(a,b)        (((const u_int32_t *)(a))[0] \
 167                                         == ((const u_int32_t *)(b))[0] \
 168                                     && ((const u_int16_t *)(a))[2] \
 169                                         == ((const u_int16_t *)(b))[2])
 170
 171 /* Minimum and maximum number of hash buckets. Must be a power of two. */
 172 #define MIN_BUCKETS             (1 << 5)        /* 32 */
 173 #define MAX_BUCKETS             (1 << 14)       /* 16384 */
 174
 175 /* Configuration default values */
 176 #define DEFAULT_LOOP_TIMEOUT    60
 177 #define DEFAULT_MAX_STALENESS   (15 * 60)       /* same as ARP timeout */
 178 #define DEFAULT_MIN_STABLE_AGE  1
 179
 180 /******************************************************************
 181                     NETGRAPH PARSE TYPES
 182 ******************************************************************/
 183
 184 /*
 185  * How to determine the length of the table returned by NGM_BRIDGE_GET_TABLE
 186  */
 187 static int
 188 ng_bridge_getTableLength(const struct ng_parse_type *type,
 189         const u_char *start, const u_char *buf)
 190 {
 191         const struct ng_bridge_host_ary *const hary
 192             = (const struct ng_bridge_host_ary *)(buf - sizeof(u_int32_t));
 193
 194         return hary->numHosts;
 195 }
 196
 197 /* Parse type for struct ng_bridge_host_ary */
 198 static const struct ng_parse_struct_field ng_bridge_host_type_fields[]
 199         = NG_BRIDGE_HOST_TYPE_INFO(&ng_parse_enaddr_type);
 200 static const struct ng_parse_type ng_bridge_host_type = {
 201         &ng_parse_struct_type,
 202         &ng_bridge_host_type_fields
 203 };
 204 static const struct ng_parse_array_info ng_bridge_hary_type_info = {
 205         &ng_bridge_host_type,
 206         ng_bridge_getTableLength
 207 };
 208 static const struct ng_parse_type ng_bridge_hary_type = {
 209         &ng_parse_array_type,
 210         &ng_bridge_hary_type_info
 211 };
 212 static const struct ng_parse_struct_field ng_bridge_host_ary_type_fields[]
 213         = NG_BRIDGE_HOST_ARY_TYPE_INFO(&ng_bridge_hary_type);
 214 static const struct ng_parse_type ng_bridge_host_ary_type = {
 215         &ng_parse_struct_type,
 216         &ng_bridge_host_ary_type_fields
 217 };
 218
 219 /* Parse type for struct ng_bridge_config */
 220 static const struct ng_parse_struct_field ng_bridge_config_type_fields[]
 221         = NG_BRIDGE_CONFIG_TYPE_INFO;
 222 static const struct ng_parse_type ng_bridge_config_type = {
 223         &ng_parse_struct_type,
 224         &ng_bridge_config_type_fields
 225 };
 226
 227 /* Parse type for struct ng_bridge_link_stat */
 228 static const struct ng_parse_struct_field ng_bridge_stats_type_fields[]
 229         = NG_BRIDGE_STATS_TYPE_INFO;
 230 static const struct ng_parse_type ng_bridge_stats_type = {
 231         &ng_parse_struct_type,
 232         &ng_bridge_stats_type_fields
 233 };
 234
 235 /* List of commands and how to convert arguments to/from ASCII */
 236 static const struct ng_cmdlist ng_bridge_cmdlist[] = {
 237         {
 238           NGM_BRIDGE_COOKIE,
 239           NGM_BRIDGE_SET_CONFIG,
 240           "setconfig",
 241           &ng_bridge_config_type,
 242           NULL
 243         },
 244         {
 245           NGM_BRIDGE_COOKIE,
 246           NGM_BRIDGE_GET_CONFIG,
 247           "getconfig",
 248           NULL,
 249           &ng_bridge_config_type
 250         },
 251         {
 252           NGM_BRIDGE_COOKIE,
 253           NGM_BRIDGE_RESET,
 254           "reset",
 255           NULL,
 256           NULL
 257         },
 258         {
 259           NGM_BRIDGE_COOKIE,
 260           NGM_BRIDGE_GET_STATS,
 261           "getstats",
 262           &ng_parse_uint32_type,
 263           &ng_bridge_stats_type
 264         },
 265         {
 266           NGM_BRIDGE_COOKIE,
 267           NGM_BRIDGE_CLR_STATS,
 268           "clrstats",
 269           &ng_parse_uint32_type,
 270           NULL
 271         },
 272         {
 273           NGM_BRIDGE_COOKIE,
 274           NGM_BRIDGE_GETCLR_STATS,
 275           "getclrstats",
 276           &ng_parse_uint32_type,
 277           &ng_bridge_stats_type
 278         },
 279         {
 280           NGM_BRIDGE_COOKIE,
 281           NGM_BRIDGE_GET_TABLE,
 282           "gettable",
 283           NULL,
 284           &ng_bridge_host_ary_type
 285         },
 286         {
 287           NGM_BRIDGE_COOKIE,
 288           NGM_BRIDGE_SET_PERSISTENT,
 289           "setpersistent",
 290           NULL,
 291           NULL
 292         },
 293         { 0 }
 294 };
 295
 296 /* Node type descriptor */
 297 static struct ng_type ng_bridge_typestruct = {
 298         .version =      NG_ABI_VERSION,
 299         .name =         NG_BRIDGE_NODE_TYPE,
 300         .constructor =  ng_bridge_constructor,
 301         .rcvmsg =       ng_bridge_rcvmsg,
 302         .shutdown =     ng_bridge_shutdown,
 303         .newhook =      ng_bridge_newhook,
 304         .rcvdata =      ng_bridge_rcvdata,
 305         .disconnect =   ng_bridge_disconnect,
 306         .cmdlist =      ng_bridge_cmdlist,
 307 };
 308 NETGRAPH_INIT(bridge, &ng_bridge_typestruct);
 309
 310 /******************************************************************
 311                     NETGRAPH NODE METHODS
 312 ******************************************************************/
 313
 314 /*
 315  * Node constructor
 316  */
 317 static int
 318 ng_bridge_constructor(node_p node)
 319 {
 320         priv_p priv;
 321
 322         /* Allocate and initialize private info */
 323         priv = malloc(sizeof(*priv), M_NETGRAPH_BRIDGE, M_WAITOK | M_ZERO);
 324         ng_callout_init(&priv->timer);
 325
 326         /* Allocate and initialize hash table, etc. */
 327         priv->tab = malloc(MIN_BUCKETS * sizeof(*priv->tab),
 328             M_NETGRAPH_BRIDGE, M_WAITOK | M_ZERO);
 329         priv->numBuckets = MIN_BUCKETS;
 330         priv->hashMask = MIN_BUCKETS - 1;
 331         priv->conf.debugLevel = 1;
 332         priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT;
 333         priv->conf.maxStaleness = DEFAULT_MAX_STALENESS;
 334         priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE;
 335         priv->sendUnknown = 1;         /* classic bridge */
 336
 337         /*
 338          * This node has all kinds of stuff that could be screwed by SMP.
 339          * Until it gets it's own internal protection, we go through in
 340          * single file. This could hurt a machine bridging between two
 341          * GB ethernets so it should be fixed.
 342          * When it's fixed the process SHOULD NOT SLEEP, spinlocks please!
 343          * (and atomic ops )
 344          */
 345         NG_NODE_FORCE_WRITER(node);
 346         NG_NODE_SET_PRIVATE(node, priv);
 347         priv->node = node;
 348
 349         /* Start timer; timer is always running while node is alive */
 350         ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0);
 351
 352         /* Done */
 353         return (0);
 354 }
 355
 356 /*
 357  * Method for attaching a new hook
 358  */
 359 static  int
 360 ng_bridge_newhook(node_p node, hook_p hook, const char *name)
 361 {
 362         const priv_p priv = NG_NODE_PRIVATE(node);
 363         char linkName[NG_HOOKSIZ];
 364         u_int32_t linkNum;
 365         link_p link;
 366         const char *prefix = NG_BRIDGE_HOOK_LINK_PREFIX;
 367         bool isUplink;
 368
 369         /* Check for a link hook */
 370         if (strlen(name) <= strlen(prefix))
 371                 return (EINVAL);       /* Unknown hook name */
 372
 373         isUplink = (name[0] == 'u');
 374         if (isUplink)
 375                 prefix = NG_BRIDGE_HOOK_UPLINK_PREFIX;
 376
 377         /* primitive parsing */
 378         linkNum = strtoul(name + strlen(prefix), NULL, 10);
 379         /* validation by comparing against the reconstucted name  */
 380         snprintf(linkName, sizeof(linkName), "%s%u", prefix, linkNum);
 381         if (strcmp(linkName, name) != 0)
 382                 return (EINVAL);
 383
 384         if (linkNum == 0 && isUplink)
 385                 return (EINVAL);
 386
 387         if(NG_PEER_NODE(hook) == node)
 388                 return (ELOOP);
 389
 390         link = malloc(sizeof(*link), M_NETGRAPH_BRIDGE, M_ZERO);
 391         if (link == NULL)
 392                 return (ENOMEM);
 393
 394         link->stats.recvOctets = counter_u64_alloc(M_WAITOK);
 395         link->stats.recvPackets = counter_u64_alloc(M_WAITOK);
 396         link->stats.recvMulticasts = counter_u64_alloc(M_WAITOK);
 397         link->stats.recvBroadcasts = counter_u64_alloc(M_WAITOK);
 398         link->stats.recvUnknown = counter_u64_alloc(M_WAITOK);
 399         link->stats.recvRunts = counter_u64_alloc(M_WAITOK);
 400         link->stats.recvInvalid = counter_u64_alloc(M_WAITOK);
 401         link->stats.xmitOctets = counter_u64_alloc(M_WAITOK);
 402         link->stats.xmitPackets = counter_u64_alloc(M_WAITOK);
 403         link->stats.xmitMulticasts = counter_u64_alloc(M_WAITOK);
 404         link->stats.xmitBroadcasts = counter_u64_alloc(M_WAITOK);
 405         link->stats.loopDrops = counter_u64_alloc(M_WAITOK);
 406         link->stats.loopDetects = counter_u64_alloc(M_WAITOK);
 407         link->stats.memoryFailures = counter_u64_alloc(M_WAITOK);
 408
 409         link->hook = hook;
 410         if (isUplink) {
 411                 link->learnMac = 0;
 412                 link->sendUnknown = 1;
 413                 if (priv->numLinks == 0)        /* if the first link is an uplink */
 414                     priv->sendUnknown = 0;      /* switch to restrictive mode */
 415         } else {
 416                 link->learnMac = 1;
 417                 link->sendUnknown = priv->sendUnknown;
 418         }
 419
 420         NG_HOOK_SET_PRIVATE(hook, link);
 421         priv->numLinks++;
 422         return (0);
 423 }
 424
 425 /*
 426  * Receive a control message
 427  */
 428 static void ng_bridge_clear_link_stats(struct ng_bridge_link_kernel_stats * p)
 429 {
 430         counter_u64_zero(p->recvOctets);
 431         counter_u64_zero(p->recvPackets);
 432         counter_u64_zero(p->recvMulticasts);
 433         counter_u64_zero(p->recvBroadcasts);
 434         counter_u64_zero(p->recvUnknown);
 435         counter_u64_zero(p->recvRunts);
 436         counter_u64_zero(p->recvInvalid);
 437         counter_u64_zero(p->xmitOctets);
 438         counter_u64_zero(p->xmitPackets);
 439         counter_u64_zero(p->xmitMulticasts);
 440         counter_u64_zero(p->xmitBroadcasts);
 441         counter_u64_zero(p->loopDrops);
 442         counter_u64_zero(p->loopDetects);
 443         counter_u64_zero(p->memoryFailures);
 444 };
 445
 446 static int
 447 ng_bridge_reset_link(hook_p hook, void *arg __unused)
 448 {
 449         link_p priv = NG_HOOK_PRIVATE(hook);
 450
 451         priv->loopCount = 0;
 452         ng_bridge_clear_link_stats(&priv->stats);
 453         return (1);
 454 }
 455
 456 static int
 457 ng_bridge_rcvmsg(node_p node, item_p item, hook_p lasthook)
 458 {
 459         const priv_p priv = NG_NODE_PRIVATE(node);
 460         struct ng_mesg *resp = NULL;
 461         int error = 0;
 462         struct ng_mesg *msg;
 463
 464         NGI_GET_MSG(item, msg);
 465         switch (msg->header.typecookie) {
 466 #ifdef NGM_BRIDGE_TABLE_ABI
 467         case NGM_BRIDGE_COOKIE_TBL:
 468                 switch (msg->header.cmd) {
 469                 case NGM_BRIDGE_GET_CONFIG:
 470                     {
 471                         struct ng_bridge_config_tbl *conf;
 472
 473                         NG_MKRESPONSE(resp, msg, sizeof(*conf),
 474                             M_NOWAIT|M_ZERO);
 475                         if (resp == NULL) {
 476                                 error = ENOMEM;
 477                                 break;
 478                         }
 479                         conf = (struct ng_bridge_config_tbl *)resp->data;
 480                         conf->cfg = priv->conf;
 481                         break;
 482                     }
 483                 case NGM_BRIDGE_SET_CONFIG:
 484                     {
 485                         struct ng_bridge_config_tbl *conf;
 486
 487                         if (msg->header.arglen != sizeof(*conf)) {
 488                                 error = EINVAL;
 489                                 break;
 490                         }
 491                         conf = (struct ng_bridge_config_tbl *)msg->data;
 492                         priv->conf = conf->cfg;
 493                         break;
 494                     }
 495                 case NGM_BRIDGE_GET_TABLE:
 496                     {
 497                         struct ng_bridge_host_tbl_ary *ary;
 498                         struct ng_bridge_hent *hent;
 499                         int i, bucket;
 500
 501                         NG_MKRESPONSE(resp, msg, sizeof(*ary) +
 502                             (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT);
 503                         if (resp == NULL) {
 504                                 error = ENOMEM;
 505                                 break;
 506                         }
 507                         ary = (struct ng_bridge_host_tbl_ary *)resp->data;
 508                         ary->numHosts = priv->numHosts;
 509                         i = 0;
 510                         for (bucket = 0; bucket < priv->numBuckets; bucket++) {
 511                                 SLIST_FOREACH(hent, &priv->tab[bucket], next) {
 512                                         const char *name = NG_HOOK_NAME(hent->host.link->hook);
 513                                         const char *prefix = name[0] == 'u' ?
 514                                             NG_BRIDGE_HOOK_UPLINK_PREFIX :
 515                                             NG_BRIDGE_HOOK_LINK_PREFIX;
 516
 517                                         memcpy(ary->hosts[i].addr,
 518                                             hent->host.addr,
 519                                             sizeof(ary->hosts[i].addr));
 520                                         ary->hosts[i].age = hent->host.age;
 521                                         ary->hosts[i].staleness =
 522                                              hent->host.staleness;
 523                                         ary->hosts[i].linkNum = strtol(
 524                                             name + strlen(prefix), NULL, 10);
 525                                         i++;
 526                                 }
 527                         }
 528                         break;
 529                     }
 530                 }
 531                 /* If already handled break, otherwise use new ABI. */
 532                 if (resp != NULL || error != 0)
 533                     break;
 534 #endif /* NGM_BRIDGE_TABLE_ABI */
 535         case NGM_BRIDGE_COOKIE:
 536                 switch (msg->header.cmd) {
 537                 case NGM_BRIDGE_GET_CONFIG:
 538                     {
 539                         struct ng_bridge_config *conf;
 540
 541                         NG_MKRESPONSE(resp, msg,
 542                             sizeof(struct ng_bridge_config), M_NOWAIT);
 543                         if (resp == NULL) {
 544                                 error = ENOMEM;
 545                                 break;
 546                         }
 547                         conf = (struct ng_bridge_config *)resp->data;
 548                         *conf = priv->conf;     /* no sanity checking needed */
 549                         break;
 550                     }
 551                 case NGM_BRIDGE_SET_CONFIG:
 552                     {
 553                         struct ng_bridge_config *conf;
 554
 555                         if (msg->header.arglen
 556                             != sizeof(struct ng_bridge_config)) {
 557                                 error = EINVAL;
 558                                 break;
 559                         }
 560                         conf = (struct ng_bridge_config *)msg->data;
 561                         priv->conf = *conf;
 562                         break;
 563                     }
 564                 case NGM_BRIDGE_RESET:
 565                     {
 566                         hook_p rethook;
 567
 568                         /* Flush all entries in the hash table */
 569                         ng_bridge_remove_hosts(priv, NULL);
 570
 571                         /* Reset all loop detection counters and stats */
 572                         NG_NODE_FOREACH_HOOK(node, ng_bridge_reset_link, NULL,
 573                             rethook);
 574                         break;
 575                     }
 576                 case NGM_BRIDGE_GET_STATS:
 577                 case NGM_BRIDGE_CLR_STATS:
 578                 case NGM_BRIDGE_GETCLR_STATS:
 579                     {
 580                         hook_p hook;
 581                         link_p link;
 582                         char linkName[NG_HOOKSIZ];
 583                         int linkNum;
 584
 585                         /* Get link number */
 586                         if (msg->header.arglen != sizeof(u_int32_t)) {
 587                                 error = EINVAL;
 588                                 break;
 589                         }
 590                         linkNum = *((int32_t *)msg->data);
 591                         if (linkNum < 0)
 592                                 snprintf(linkName, sizeof(linkName),
 593                                     "%s%u", NG_BRIDGE_HOOK_UPLINK_PREFIX, -linkNum);
 594                         else
 595                                 snprintf(linkName, sizeof(linkName),
 596                                     "%s%u", NG_BRIDGE_HOOK_LINK_PREFIX, linkNum);
 597
 598                         if ((hook = ng_findhook(node, linkName)) == NULL) {
 599                                 error = ENOTCONN;
 600                                 break;
 601                         }
 602                         link = NG_HOOK_PRIVATE(hook);
 603
 604                         /* Get/clear stats */
 605                         if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) {
 606                                 struct ng_bridge_link_stats *rs;
 607
 608                                 NG_MKRESPONSE(resp, msg,
 609                                     sizeof(link->stats), M_NOWAIT);
 610                                 if (resp == NULL) {
 611                                         error = ENOMEM;
 612                                         break;
 613                                 }
 614                                 rs = (struct ng_bridge_link_stats *)resp->data;
 615 #define FETCH(x)        rs->x = counter_u64_fetch(link->stats.x)
 616                                 FETCH(recvOctets);
 617                                 FETCH(recvPackets);
 618                                 FETCH(recvMulticasts);
 619                                 FETCH(recvBroadcasts);
 620                                 FETCH(recvUnknown);
 621                                 FETCH(recvRunts);
 622                                 FETCH(recvInvalid);
 623                                 FETCH(xmitOctets);
 624                                 FETCH(xmitPackets);
 625                                 FETCH(xmitMulticasts);
 626                                 FETCH(xmitBroadcasts);
 627                                 FETCH(loopDrops);
 628                                 FETCH(loopDetects);
 629                                 FETCH(memoryFailures);
 630 #undef FETCH
 631                         }
 632                         if (msg->header.cmd != NGM_BRIDGE_GET_STATS)
 633                                 ng_bridge_clear_link_stats(&link->stats);
 634                         break;
 635                     }
 636                 case NGM_BRIDGE_GET_TABLE:
 637                     {
 638                         struct ng_bridge_host_ary *ary;
 639                         struct ng_bridge_hent *hent;
 640                         int i = 0, bucket;
 641
 642                         NG_MKRESPONSE(resp, msg, sizeof(*ary)
 643                             + (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT);
 644                         if (resp == NULL) {
 645                                 error = ENOMEM;
 646                                 break;
 647                         }
 648                         ary = (struct ng_bridge_host_ary *)resp->data;
 649                         ary->numHosts = priv->numHosts;
 650                         for (bucket = 0; bucket < priv->numBuckets; bucket++) {
 651                                 SLIST_FOREACH(hent, &priv->tab[bucket], next) {
 652                                         memcpy(ary->hosts[i].addr,
 653                                                hent->host.addr,
 654                                                sizeof(ary->hosts[i].addr));
 655                                         ary->hosts[i].age       = hent->host.age;
 656                                         ary->hosts[i].staleness = hent->host.staleness;
 657                                         strncpy(ary->hosts[i].hook,
 658                                                 NG_HOOK_NAME(hent->host.link->hook),
 659                                                 sizeof(ary->hosts[i].hook));
 660                                         i++;
 661                                 }
 662                         }
 663                         break;
 664                     }
 665                 case NGM_BRIDGE_SET_PERSISTENT:
 666                     {
 667                         priv->persistent = 1;
 668                         break;
 669                     }
 670                 default:
 671                         error = EINVAL;
 672                         break;
 673                 }
 674                 break;
 675         default:
 676                 error = EINVAL;
 677                 break;
 678         }
 679
 680         /* Done */
 681         NG_RESPOND_MSG(error, node, item, resp);
 682         NG_FREE_MSG(msg);
 683         return (error);
 684 }
 685
 686 /*
 687  * Receive data on a hook
 688  */
 689 struct ng_bridge_send_ctx {
 690         link_p foundFirst, incoming;
 691         struct mbuf * m;
 692         int manycast, error;
 693 };
 694
 695 static int
 696 ng_bridge_send_ctx(hook_p dst, void *arg)
 697 {
 698         struct ng_bridge_send_ctx *ctx = arg;
 699         link_p destLink = NG_HOOK_PRIVATE(dst);
 700         struct mbuf *m2 = NULL;
 701         int error = 0;
 702
 703         /* Skip incoming link */
 704         if (destLink == ctx->incoming) {
 705                 return (1);
 706         }
 707
 708         /* Skip sending unknowns to undesired links  */
 709         if (!ctx->manycast && !destLink->sendUnknown)
 710                 return (1);
 711
 712         if (ctx->foundFirst == NULL) {
 713                 /*
 714                  * This is the first usable link we have found.
 715                  * Reserve it for the originals.
 716                  * If we never find another we save a copy.
 717                  */
 718                 ctx->foundFirst = destLink;
 719                 return (1);
 720         }
 721
 722         /*
 723          * It's usable link but not the reserved (first) one.
 724          * Copy mbuf info for sending.
 725          */
 726         m2 = m_dup(ctx->m, M_NOWAIT);   /* XXX m_copypacket() */
 727         if (m2 == NULL) {
 728                 counter_u64_add(ctx->incoming->stats.memoryFailures, 1);
 729                 ctx->error = ENOBUFS;
 730                 return (0);            /* abort loop */
 731         }
 732
 733         /* Update stats */
 734         counter_u64_add(destLink->stats.xmitPackets, 1);
 735         counter_u64_add(destLink->stats.xmitOctets, m2->m_pkthdr.len);
 736         switch (ctx->manycast) {
 737          default:                                       /* unknown unicast */
 738                 break;
 739          case 1:                                        /* multicast */
 740                 counter_u64_add(destLink->stats.xmitMulticasts, 1);
 741                 break;
 742          case 2:                                        /* broadcast */
 743                 counter_u64_add(destLink->stats.xmitBroadcasts, 1);
 744                 break;
 745         }
 746
 747         /* Send packet */
 748         NG_SEND_DATA_ONLY(error, destLink->hook, m2);
 749         if(error)
 750           ctx->error = error;
 751         return (1);
 752 }
 753
 754 static int
 755 ng_bridge_rcvdata(hook_p hook, item_p item)
 756 {
 757         const node_p node = NG_HOOK_NODE(hook);
 758         const priv_p priv = NG_NODE_PRIVATE(node);
 759         struct ng_bridge_host *host;
 760         struct ether_header *eh;
 761         struct ng_bridge_send_ctx ctx = { 0 };
 762         hook_p ret;
 763
 764         NGI_GET_M(item, ctx.m);
 765
 766         ctx.incoming = NG_HOOK_PRIVATE(hook);
 767         /* Sanity check packet and pull up header */
 768         if (ctx.m->m_pkthdr.len < ETHER_HDR_LEN) {
 769                 counter_u64_add(ctx.incoming->stats.recvRunts, 1);
 770                 NG_FREE_ITEM(item);
 771                 NG_FREE_M(ctx.m);
 772                 return (EINVAL);
 773         }
 774         if (ctx.m->m_len < ETHER_HDR_LEN && !(ctx.m = m_pullup(ctx.m, ETHER_HDR_LEN))) {
 775                 counter_u64_add(ctx.incoming->stats.memoryFailures, 1);
 776                 NG_FREE_ITEM(item);
 777                 return (ENOBUFS);
 778         }
 779         eh = mtod(ctx.m, struct ether_header *);
 780         if ((eh->ether_shost[0] & 1) != 0) {
 781                 counter_u64_add(ctx.incoming->stats.recvInvalid, 1);
 782                 NG_FREE_ITEM(item);
 783                 NG_FREE_M(ctx.m);
 784                 return (EINVAL);
 785         }
 786
 787         /* Is link disabled due to a loopback condition? */
 788         if (ctx.incoming->loopCount != 0) {
 789                 counter_u64_add(ctx.incoming->stats.loopDrops, 1);
 790                 NG_FREE_ITEM(item);
 791                 NG_FREE_M(ctx.m);
 792                 return (ELOOP);         /* XXX is this an appropriate error? */
 793         }
 794
 795         /* Update stats */
 796         counter_u64_add(ctx.incoming->stats.recvPackets, 1);
 797         counter_u64_add(ctx.incoming->stats.recvOctets, ctx.m->m_pkthdr.len);
 798         if ((ctx.manycast = (eh->ether_dhost[0] & 1)) != 0) {
 799                 if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) {
 800                         counter_u64_add(ctx.incoming->stats.recvBroadcasts, 1);
 801                         ctx.manycast = 2;
 802                 } else
 803                         counter_u64_add(ctx.incoming->stats.recvMulticasts, 1);
 804         }
 805
 806         /* Look up packet's source Ethernet address in hashtable */
 807         if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) {
 808                 /* Update time since last heard from this host */
 809                 host->staleness = 0;
 810
 811                 /* Did host jump to a different link? */
 812                 if (host->link != ctx.incoming) {
 813                         /*
 814                          * If the host's old link was recently established
 815                          * on the old link and it's already jumped to a new
 816                          * link, declare a loopback condition.
 817                          */
 818                         if (host->age < priv->conf.minStableAge) {
 819                                 /* Log the problem */
 820                                 if (priv->conf.debugLevel >= 2) {
 821                                         struct ifnet *ifp = ctx.m->m_pkthdr.rcvif;
 822                                         char suffix[32];
 823
 824                                         if (ifp != NULL)
 825                                                 snprintf(suffix, sizeof(suffix),
 826                                                     " (%s)", ifp->if_xname);
 827                                         else
 828                                                 *suffix = '\0';
 829                                         log(LOG_WARNING, "ng_bridge: %s:"
 830                                             " loopback detected on %s%s\n",
 831                                             ng_bridge_nodename(node),
 832                                             NG_HOOK_NAME(hook), suffix);
 833                                 }
 834
 835                                 /* Mark link as linka non grata */
 836                                 ctx.incoming->loopCount = priv->conf.loopTimeout;
 837                                 counter_u64_add(ctx.incoming->stats.loopDetects, 1);
 838
 839                                 /* Forget all hosts on this link */
 840                                 ng_bridge_remove_hosts(priv, ctx.incoming);
 841
 842                                 /* Drop packet */
 843                                 counter_u64_add(ctx.incoming->stats.loopDrops, 1);
 844                                 NG_FREE_ITEM(item);
 845                                 NG_FREE_M(ctx.m);
 846                                 return (ELOOP);         /* XXX appropriate? */
 847                         }
 848
 849                         /* Move host over to new link */
 850                         host->link = ctx.incoming;
 851                         host->age = 0;
 852                 }
 853         } else if (ctx.incoming->learnMac) {
 854                 if (!ng_bridge_put(priv, eh->ether_shost, ctx.incoming)) {
 855                         counter_u64_add(ctx.incoming->stats.memoryFailures, 1);
 856                         NG_FREE_ITEM(item);
 857                         NG_FREE_M(ctx.m);
 858                         return (ENOMEM);
 859                 }
 860         }
 861
 862         /* Run packet through ipfw processing, if enabled */
 863 #if 0
 864         if (priv->conf.ipfw[linkNum] && V_fw_enable && V_ip_fw_chk_ptr != NULL) {
 865                 /* XXX not implemented yet */
 866         }
 867 #endif
 868
 869         /*
 870          * If unicast and destination host known, deliver to host's link,
 871          * unless it is the same link as the packet came in on.
 872          */
 873         if (!ctx.manycast) {
 874                 /* Determine packet destination link */
 875                 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) {
 876                         link_p destLink = host->link;
 877
 878                         /* If destination same as incoming link, do nothing */
 879                         if (destLink == ctx.incoming) {
 880                                 NG_FREE_ITEM(item);
 881                                 NG_FREE_M(ctx.m);
 882                                 return (0);
 883                         }
 884
 885                         /* Deliver packet out the destination link */
 886                         counter_u64_add(destLink->stats.xmitPackets, 1);
 887                         counter_u64_add(destLink->stats.xmitOctets, ctx.m->m_pkthdr.len);
 888                         NG_FWD_NEW_DATA(ctx.error, item, destLink->hook, ctx.m);
 889                         return (ctx.error);
 890                 }
 891
 892                 /* Destination host is not known */
 893                 counter_u64_add(ctx.incoming->stats.recvUnknown, 1);
 894         }
 895
 896         /* Distribute unknown, multicast, broadcast pkts to all other links */
 897         NG_NODE_FOREACH_HOOK(node, ng_bridge_send_ctx, &ctx, ret);
 898
 899         /* If we never saw a good link, leave. */
 900         if (ctx.foundFirst == NULL || ctx.error != 0) {
 901                 NG_FREE_ITEM(item);
 902                 NG_FREE_M(ctx.m);
 903                 return (ctx.error);
 904         }
 905
 906         /*
 907          * If we've sent all the others, send the original
 908          * on the first link we found.
 909          */
 910         NG_FWD_NEW_DATA(ctx.error, item, ctx.foundFirst->hook, ctx.m);
 911         return (ctx.error);
 912 }
 913
 914 /*
 915  * Shutdown node
 916  */
 917 static int
 918 ng_bridge_shutdown(node_p node)
 919 {
 920         const priv_p priv = NG_NODE_PRIVATE(node);
 921
 922         /*
 923          * Shut down everything including the timer.  Even if the
 924          * callout has already been dequeued and is about to be
 925          * run, ng_bridge_timeout() won't be fired as the node
 926          * is already marked NGF_INVALID, so we're safe to free
 927          * the node now.
 928          */
 929         KASSERT(priv->numLinks == 0 && priv->numHosts == 0,
 930             ("%s: numLinks=%d numHosts=%d",
 931             __func__, priv->numLinks, priv->numHosts));
 932         ng_uncallout(&priv->timer, node);
 933         NG_NODE_SET_PRIVATE(node, NULL);
 934         NG_NODE_UNREF(node);
 935         free(priv->tab, M_NETGRAPH_BRIDGE);
 936         free(priv, M_NETGRAPH_BRIDGE);
 937         return (0);
 938 }
 939
 940 /*
 941  * Hook disconnection.
 942  */
 943 static int
 944 ng_bridge_disconnect(hook_p hook)
 945 {
 946         const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 947         link_p link = NG_HOOK_PRIVATE(hook);
 948
 949         /* Remove all hosts associated with this link */
 950         ng_bridge_remove_hosts(priv, link);
 951
 952         /* Free associated link information */
 953         counter_u64_free(link->stats.recvOctets);
 954         counter_u64_free(link->stats.recvPackets);
 955         counter_u64_free(link->stats.recvMulticasts);
 956         counter_u64_free(link->stats.recvBroadcasts);
 957         counter_u64_free(link->stats.recvUnknown);
 958         counter_u64_free(link->stats.recvRunts);
 959         counter_u64_free(link->stats.recvInvalid);
 960         counter_u64_free(link->stats.xmitOctets);
 961         counter_u64_free(link->stats.xmitPackets);
 962         counter_u64_free(link->stats.xmitMulticasts);
 963         counter_u64_free(link->stats.xmitBroadcasts);
 964         counter_u64_free(link->stats.loopDrops);
 965         counter_u64_free(link->stats.loopDetects);
 966         counter_u64_free(link->stats.memoryFailures);
 967         free(link, M_NETGRAPH_BRIDGE);
 968         priv->numLinks--;
 969
 970         /* If no more hooks, go away */
 971         if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
 972             && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))
 973             && !priv->persistent) {
 974                 ng_rmnode_self(NG_HOOK_NODE(hook));
 975         }
 976         return (0);
 977 }
 978
 979 /******************************************************************
 980                     HASH TABLE FUNCTIONS
 981 ******************************************************************/
 982
 983 /*
 984  * Hash algorithm
 985  */
 986 #define HASH(addr,mask)         ( (((const u_int16_t *)(addr))[0]       \
 987                                  ^ ((const u_int16_t *)(addr))[1]       \
 988                                  ^ ((const u_int16_t *)(addr))[2]) & (mask) )
 989
 990 /*
 991  * Find a host entry in the table.
 992  */
 993 static struct ng_bridge_host *
 994 ng_bridge_get(priv_cp priv, const u_char *addr)
 995 {
 996         const int bucket = HASH(addr, priv->hashMask);
 997         struct ng_bridge_hent *hent;
 998
 999         SLIST_FOREACH(hent, &priv->tab[bucket], next) {
1000                 if (ETHER_EQUAL(hent->host.addr, addr))
1001                         return (&hent->host);
1002         }
1003         return (NULL);
1004 }
1005
1006 /*
1007  * Add a new host entry to the table. This assumes the host doesn't
1008  * already exist in the table. Returns 1 on success, 0 if there
1009  * was a memory allocation failure.
1010  */
1011 static int
1012 ng_bridge_put(priv_p priv, const u_char *addr, link_p link)
1013 {
1014         const int bucket = HASH(addr, priv->hashMask);
1015         struct ng_bridge_hent *hent;
1016
1017 #ifdef INVARIANTS
1018         /* Assert that entry does not already exist in hashtable */
1019         SLIST_FOREACH(hent, &priv->tab[bucket], next) {
1020                 KASSERT(!ETHER_EQUAL(hent->host.addr, addr),
1021                     ("%s: entry %6D exists in table", __func__, addr, ":"));
1022         }
1023 #endif
1024
1025         /* Allocate and initialize new hashtable entry */
1026         hent = malloc(sizeof(*hent), M_NETGRAPH_BRIDGE, M_NOWAIT);
1027         if (hent == NULL)
1028                 return (0);
1029         bcopy(addr, hent->host.addr, ETHER_ADDR_LEN);
1030         hent->host.link = link;
1031         hent->host.staleness = 0;
1032         hent->host.age = 0;
1033
1034         /* Add new element to hash bucket */
1035         SLIST_INSERT_HEAD(&priv->tab[bucket], hent, next);
1036         priv->numHosts++;
1037
1038         /* Resize table if necessary */
1039         ng_bridge_rehash(priv);
1040         return (1);
1041 }
1042
1043 /*
1044  * Resize the hash table. We try to maintain the number of buckets
1045  * such that the load factor is in the range 0.25 to 1.0.
1046  *
1047  * If we can't get the new memory then we silently fail. This is OK
1048  * because things will still work and we'll try again soon anyway.
1049  */
1050 static void
1051 ng_bridge_rehash(priv_p priv)
1052 {
1053         struct ng_bridge_bucket *newTab;
1054         int oldBucket, newBucket;
1055         int newNumBuckets;
1056         u_int newMask;
1057
1058         /* Is table too full or too empty? */
1059         if (priv->numHosts > priv->numBuckets
1060             && (priv->numBuckets << 1) <= MAX_BUCKETS)
1061                 newNumBuckets = priv->numBuckets << 1;
1062         else if (priv->numHosts < (priv->numBuckets >> 2)
1063             && (priv->numBuckets >> 2) >= MIN_BUCKETS)
1064                 newNumBuckets = priv->numBuckets >> 2;
1065         else
1066                 return;
1067         newMask = newNumBuckets - 1;
1068
1069         /* Allocate and initialize new table */
1070         newTab = malloc(newNumBuckets * sizeof(*newTab),
1071             M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO);
1072         if (newTab == NULL)
1073                 return;
1074
1075         /* Move all entries from old table to new table */
1076         for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) {
1077                 struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket];
1078
1079                 while (!SLIST_EMPTY(oldList)) {
1080                         struct ng_bridge_hent *const hent
1081                             = SLIST_FIRST(oldList);
1082
1083                         SLIST_REMOVE_HEAD(oldList, next);
1084                         newBucket = HASH(hent->host.addr, newMask);
1085                         SLIST_INSERT_HEAD(&newTab[newBucket], hent, next);
1086                 }
1087         }
1088
1089         /* Replace old table with new one */
1090         if (priv->conf.debugLevel >= 3) {
1091                 log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n",
1092                     ng_bridge_nodename(priv->node),
1093                     priv->numBuckets, newNumBuckets);
1094         }
1095         free(priv->tab, M_NETGRAPH_BRIDGE);
1096         priv->numBuckets = newNumBuckets;
1097         priv->hashMask = newMask;
1098         priv->tab = newTab;
1099         return;
1100 }
1101
1102 /******************************************************************
1103                     MISC FUNCTIONS
1104 ******************************************************************/
1105
1106 /*
1107  * Remove all hosts associated with a specific link from the hashtable.
1108  * If linkNum == -1, then remove all hosts in the table.
1109  */
1110 static void
1111 ng_bridge_remove_hosts(priv_p priv, link_p link)
1112 {
1113         int bucket;
1114
1115         for (bucket = 0; bucket < priv->numBuckets; bucket++) {
1116                 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]);
1117
1118                 while (*hptr != NULL) {
1119                         struct ng_bridge_hent *const hent = *hptr;
1120
1121                         if (link == NULL || hent->host.link == link) {
1122                                 *hptr = SLIST_NEXT(hent, next);
1123                                 free(hent, M_NETGRAPH_BRIDGE);
1124                                 priv->numHosts--;
1125                         } else
1126                                 hptr = &SLIST_NEXT(hent, next);
1127                 }
1128         }
1129 }
1130
1131 /*
1132  * Handle our once-per-second timeout event. We do two things:
1133  * we decrement link->loopCount for those links being muted due to
1134  * a detected loopback condition, and we remove any hosts from
1135  * the hashtable whom we haven't heard from in a long while.
1136  */
1137 static int
1138 ng_bridge_unmute(hook_p hook, void *arg)
1139 {
1140         link_p link = NG_HOOK_PRIVATE(hook);
1141         node_p node = NG_HOOK_NODE(hook);
1142         priv_p priv = NG_NODE_PRIVATE(node);
1143         int *counter = arg;
1144
1145         if (link->loopCount != 0) {
1146                 link->loopCount--;
1147                 if (link->loopCount == 0 && priv->conf.debugLevel >= 2) {
1148                         log(LOG_INFO, "ng_bridge: %s:"
1149                             " restoring looped back %s\n",
1150                             ng_bridge_nodename(node), NG_HOOK_NAME(hook));
1151                 }
1152         }
1153         (*counter)++;
1154         return (1);
1155 }
1156
1157 static void
1158 ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2)
1159 {
1160         const priv_p priv = NG_NODE_PRIVATE(node);
1161         int bucket;
1162         int counter = 0;
1163         hook_p ret;
1164
1165         /* Update host time counters and remove stale entries */
1166         for (bucket = 0; bucket < priv->numBuckets; bucket++) {
1167                 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]);
1168
1169                 while (*hptr != NULL) {
1170                         struct ng_bridge_hent *const hent = *hptr;
1171
1172                         /* Remove hosts we haven't heard from in a while */
1173                         if (++hent->host.staleness >= priv->conf.maxStaleness) {
1174                                 *hptr = SLIST_NEXT(hent, next);
1175                                 free(hent, M_NETGRAPH_BRIDGE);
1176                                 priv->numHosts--;
1177                         } else {
1178                                 if (hent->host.age < 0xffff)
1179                                         hent->host.age++;
1180                                 hptr = &SLIST_NEXT(hent, next);
1181                                 counter++;
1182                         }
1183                 }
1184         }
1185         KASSERT(priv->numHosts == counter,
1186             ("%s: hosts: %d != %d", __func__, priv->numHosts, counter));
1187
1188         /* Decrease table size if necessary */
1189         ng_bridge_rehash(priv);
1190
1191         /* Decrease loop counter on muted looped back links */
1192         counter = 0;
1193         NG_NODE_FOREACH_HOOK(node, ng_bridge_unmute, &counter, ret);
1194         KASSERT(priv->numLinks == counter,
1195             ("%s: links: %d != %d", __func__, priv->numLinks, counter));
1196
1197         /* Register a new timeout, keeping the existing node reference */
1198         ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0);
1199 }
1200
1201 /*
1202  * Return node's "name", even if it doesn't have one.
1203  */
1204 static const char *
1205 ng_bridge_nodename(node_cp node)
1206 {
1207         static char name[NG_NODESIZ];
1208
1209         if (NG_NODE_HAS_NAME(node))
1210                 snprintf(name, sizeof(name), "%s", NG_NODE_NAME(node));
1211         else
1212                 snprintf(name, sizeof(name), "[%x]", ng_node2ID(node));
1213         return name;
1214 }