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