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