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sys/netgraph/ng_bridge.c
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1 2 /* 3 * ng_bridge.c 4 * 5 * Copyright (c) 2000 Whistle Communications, Inc. 6 * All rights reserved. 7 * 8 * Subject to the following obligations and disclaimer of warranty, use and 9 * redistribution of this software, in source or object code forms, with or 10 * without modifications are expressly permitted by Whistle Communications; 11 * provided, however, that: 12 * 1. Any and all reproductions of the source or object code must include the 13 * copyright notice above and the following disclaimer of warranties; and 14 * 2. No rights are granted, in any manner or form, to use Whistle 15 * Communications, Inc. trademarks, including the mark "WHISTLE 16 * COMMUNICATIONS" on advertising, endorsements, or otherwise except as 17 * such appears in the above copyright notice or in the software. 18 * 19 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND 20 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO 21 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE, 22 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF 23 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. 24 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY 25 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS 26 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE. 27 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES 28 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING 29 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 30 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR 31 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY 32 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 33 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 34 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY 35 * OF SUCH DAMAGE. 36 * 37 * Author: Archie Cobbs <archie@freebsd.org> 38 * 39 * $FreeBSD$ 40 */ 41 42 /* 43 * ng_bridge(4) netgraph node type 44 * 45 * The node performs standard intelligent Ethernet bridging over 46 * each of its connected hooks, or links. A simple loop detection 47 * algorithm is included which disables a link for priv->conf.loopTimeout 48 * seconds when a host is seen to have jumped from one link to 49 * another within priv->conf.minStableAge seconds. 50 * 51 * We keep a hashtable that maps Ethernet addresses to host info, 52 * which is contained in struct ng_bridge_host's. These structures 53 * tell us on which link the host may be found. A host's entry will 54 * expire after priv->conf.maxStaleness seconds. 55 * 56 * This node is optimzed for stable networks, where machines jump 57 * from one port to the other only rarely. 58 */ 59 60 #include <sys/param.h> 61 #include <sys/systm.h> 62 #include <sys/kernel.h> 63 #include <sys/malloc.h> 64 #include <sys/mbuf.h> 65 #include <sys/errno.h> 66 #include <sys/syslog.h> 67 #include <sys/socket.h> 68 #include <sys/ctype.h> 69 70 #include <net/if.h> 71 #include <net/ethernet.h> 72 73 #include <netinet/in.h> 74 #include <netinet/ip_fw.h> 75 76 #include <netgraph/ng_message.h> 77 #include <netgraph/netgraph.h> 78 #include <netgraph/ng_parse.h> 79 #include <netgraph/ng_bridge.h> 80 81 /* Per-link private data */ 82 struct ng_bridge_link { 83 hook_p hook; /* netgraph hook */ 84 u_int16_t loopCount; /* loop ignore timer */ 85 struct ng_bridge_link_stats stats; /* link stats */ 86 }; 87 88 /* Per-node private data */ 89 struct ng_bridge_private { 90 struct ng_bridge_bucket *tab; /* hash table bucket array */ 91 struct ng_bridge_link *links[NG_BRIDGE_MAX_LINKS]; 92 struct ng_bridge_config conf; /* node configuration */ 93 node_p node; /* netgraph node */ 94 u_int numHosts; /* num entries in table */ 95 u_int numBuckets; /* num buckets in table */ 96 u_int hashMask; /* numBuckets - 1 */ 97 int numLinks; /* num connected links */ 98 struct callout timer; /* one second periodic timer */ 99 }; 100 typedef struct ng_bridge_private *priv_p; 101 102 /* Information about a host, stored in a hash table entry */ 103 struct ng_bridge_hent { 104 struct ng_bridge_host host; /* actual host info */ 105 SLIST_ENTRY(ng_bridge_hent) next; /* next entry in bucket */ 106 }; 107 108 /* Hash table bucket declaration */ 109 SLIST_HEAD(ng_bridge_bucket, ng_bridge_hent); 110 111 /* Netgraph node methods */ 112 static ng_constructor_t ng_bridge_constructor; 113 static ng_rcvmsg_t ng_bridge_rcvmsg; 114 static ng_shutdown_t ng_bridge_rmnode; 115 static ng_newhook_t ng_bridge_newhook; 116 static ng_rcvdata_t ng_bridge_rcvdata; 117 static ng_disconnect_t ng_bridge_disconnect; 118 119 /* Other internal functions */ 120 static struct ng_bridge_host *ng_bridge_get(priv_p priv, const u_char *addr); 121 static int ng_bridge_put(priv_p priv, const u_char *addr, int linkNum); 122 static void ng_bridge_rehash(priv_p priv); 123 static void ng_bridge_remove_hosts(priv_p priv, int linkNum); 124 static void ng_bridge_timeout(void *arg); 125 static const char *ng_bridge_nodename(node_p node); 126 127 /* Ethernet broadcast */ 128 static const u_char ng_bridge_bcast_addr[ETHER_ADDR_LEN] = 129 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; 130 131 /* Store each hook's link number in the private field */ 132 #define LINK_NUM(hook) (*(u_int16_t *)(&(hook)->private)) 133 134 /* Compare Ethernet addresses using 32 and 16 bit words instead of bytewise */ 135 #define ETHER_EQUAL(a,b) (((const u_int32_t *)(a))[0] \ 136 == ((const u_int32_t *)(b))[0] \ 137 && ((const u_int16_t *)(a))[2] \ 138 == ((const u_int16_t *)(b))[2]) 139 140 /* Minimum and maximum number of hash buckets. Must be a power of two. */ 141 #define MIN_BUCKETS (1 << 5) /* 32 */ 142 #define MAX_BUCKETS (1 << 14) /* 16384 */ 143 144 /* Configuration default values */ 145 #define DEFAULT_LOOP_TIMEOUT 60 146 #define DEFAULT_MAX_STALENESS (15 * 60) /* same as ARP timeout */ 147 #define DEFAULT_MIN_STABLE_AGE 1 148 149 /****************************************************************** 150 NETGRAPH PARSE TYPES 151 ******************************************************************/ 152 153 /* 154 * How to determine the length of the table returned by NGM_BRIDGE_GET_TABLE 155 */ 156 static int 157 ng_bridge_getTableLength(const struct ng_parse_type *type, 158 const u_char *start, const u_char *buf) 159 { 160 const struct ng_bridge_host_ary *const hary 161 = (const struct ng_bridge_host_ary *)(buf - sizeof(u_int32_t)); 162 163 return hary->numHosts; 164 } 165 166 /* Parse type for struct ng_bridge_host_ary */ 167 static const struct ng_parse_struct_field ng_bridge_host_type_fields[] 168 = NG_BRIDGE_HOST_TYPE_INFO(&ng_parse_enaddr_type); 169 static const struct ng_parse_type ng_bridge_host_type = { 170 &ng_parse_struct_type, 171 &ng_bridge_host_type_fields 172 }; 173 static const struct ng_parse_array_info ng_bridge_hary_type_info = { 174 &ng_bridge_host_type, 175 ng_bridge_getTableLength 176 }; 177 static const struct ng_parse_type ng_bridge_hary_type = { 178 &ng_parse_array_type, 179 &ng_bridge_hary_type_info 180 }; 181 static const struct ng_parse_struct_field ng_bridge_host_ary_type_fields[] 182 = NG_BRIDGE_HOST_ARY_TYPE_INFO(&ng_bridge_hary_type); 183 static const struct ng_parse_type ng_bridge_host_ary_type = { 184 &ng_parse_struct_type, 185 &ng_bridge_host_ary_type_fields 186 }; 187 188 /* Parse type for struct ng_bridge_config */ 189 static const struct ng_parse_fixedarray_info ng_bridge_ipfwary_type_info = { 190 &ng_parse_uint8_type, 191 NG_BRIDGE_MAX_LINKS 192 }; 193 static const struct ng_parse_type ng_bridge_ipfwary_type = { 194 &ng_parse_fixedarray_type, 195 &ng_bridge_ipfwary_type_info 196 }; 197 static const struct ng_parse_struct_field ng_bridge_config_type_fields[] 198 = NG_BRIDGE_CONFIG_TYPE_INFO(&ng_bridge_ipfwary_type); 199 static const struct ng_parse_type ng_bridge_config_type = { 200 &ng_parse_struct_type, 201 &ng_bridge_config_type_fields 202 }; 203 204 /* Parse type for struct ng_bridge_link_stat */ 205 static const struct ng_parse_struct_field ng_bridge_stats_type_fields[] 206 = NG_BRIDGE_STATS_TYPE_INFO; 207 static const struct ng_parse_type ng_bridge_stats_type = { 208 &ng_parse_struct_type, 209 &ng_bridge_stats_type_fields 210 }; 211 212 /* List of commands and how to convert arguments to/from ASCII */ 213 static const struct ng_cmdlist ng_bridge_cmdlist[] = { 214 { 215 NGM_BRIDGE_COOKIE, 216 NGM_BRIDGE_SET_CONFIG, 217 "setconfig", 218 &ng_bridge_config_type, 219 NULL 220 }, 221 { 222 NGM_BRIDGE_COOKIE, 223 NGM_BRIDGE_GET_CONFIG, 224 "getconfig", 225 NULL, 226 &ng_bridge_config_type 227 }, 228 { 229 NGM_BRIDGE_COOKIE, 230 NGM_BRIDGE_RESET, 231 "reset", 232 NULL, 233 NULL 234 }, 235 { 236 NGM_BRIDGE_COOKIE, 237 NGM_BRIDGE_GET_STATS, 238 "getstats", 239 &ng_parse_uint32_type, 240 &ng_bridge_stats_type 241 }, 242 { 243 NGM_BRIDGE_COOKIE, 244 NGM_BRIDGE_CLR_STATS, 245 "clrstats", 246 &ng_parse_uint32_type, 247 NULL 248 }, 249 { 250 NGM_BRIDGE_COOKIE, 251 NGM_BRIDGE_GETCLR_STATS, 252 "getclrstats", 253 &ng_parse_uint32_type, 254 &ng_bridge_stats_type 255 }, 256 { 257 NGM_BRIDGE_COOKIE, 258 NGM_BRIDGE_GET_TABLE, 259 "gettable", 260 NULL, 261 &ng_bridge_host_ary_type 262 }, 263 { 0 } 264 }; 265 266 /* Node type descriptor */ 267 static struct ng_type ng_bridge_typestruct = { 268 NG_VERSION, 269 NG_BRIDGE_NODE_TYPE, 270 NULL, 271 ng_bridge_constructor, 272 ng_bridge_rcvmsg, 273 ng_bridge_rmnode, 274 ng_bridge_newhook, 275 NULL, 276 NULL, 277 ng_bridge_rcvdata, 278 ng_bridge_rcvdata, 279 ng_bridge_disconnect, 280 ng_bridge_cmdlist, 281 }; 282 NETGRAPH_INIT(bridge, &ng_bridge_typestruct); 283 284 /****************************************************************** 285 NETGRAPH NODE METHODS 286 ******************************************************************/ 287 288 /* 289 * Node constructor 290 */ 291 static int 292 ng_bridge_constructor(node_p *nodep) 293 { 294 priv_p priv; 295 int error; 296 297 /* Allocate and initialize private info */ 298 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT); 299 if (priv == NULL) 300 return (ENOMEM); 301 bzero(priv, sizeof(*priv)); 302 callout_init(&priv->timer); 303 304 /* Allocate and initialize hash table, etc. */ 305 MALLOC(priv->tab, struct ng_bridge_bucket *, 306 MIN_BUCKETS * sizeof(*priv->tab), M_NETGRAPH, M_NOWAIT); 307 if (priv->tab == NULL) { 308 FREE(priv, M_NETGRAPH); 309 return (ENOMEM); 310 } 311 bzero(priv->tab, MIN_BUCKETS * sizeof(*priv->tab)); /* init SLIST's */ 312 priv->numBuckets = MIN_BUCKETS; 313 priv->hashMask = MIN_BUCKETS - 1; 314 priv->conf.debugLevel = 1; 315 priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT; 316 priv->conf.maxStaleness = DEFAULT_MAX_STALENESS; 317 priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE; 318 319 /* Call superclass constructor */ 320 if ((error = ng_make_node_common(&ng_bridge_typestruct, nodep))) { 321 FREE(priv, M_NETGRAPH); 322 return (error); 323 } 324 (*nodep)->private = priv; 325 priv->node = *nodep; 326 327 /* Start timer; timer is always running while node is alive */ 328 callout_reset(&priv->timer, hz, ng_bridge_timeout, priv->node); 329 330 /* Done */ 331 return (0); 332 } 333 334 /* 335 * Method for attaching a new hook 336 */ 337 static int 338 ng_bridge_newhook(node_p node, hook_p hook, const char *name) 339 { 340 const priv_p priv = node->private; 341 342 /* Check for a link hook */ 343 if (strncmp(name, NG_BRIDGE_HOOK_LINK_PREFIX, 344 strlen(NG_BRIDGE_HOOK_LINK_PREFIX)) == 0) { 345 const char *cp; 346 char *eptr; 347 u_long linkNum; 348 349 cp = name + strlen(NG_BRIDGE_HOOK_LINK_PREFIX); 350 if (!isdigit(*cp) || (cp[0] == '' && cp[1] != '\0')) 351 return (EINVAL); 352 linkNum = strtoul(cp, &eptr, 10); 353 if (*eptr != '\0' || linkNum >= NG_BRIDGE_MAX_LINKS) 354 return (EINVAL); 355 if (priv->links[linkNum] != NULL) 356 return (EISCONN); 357 MALLOC(priv->links[linkNum], struct ng_bridge_link *, 358 sizeof(*priv->links[linkNum]), M_NETGRAPH, M_NOWAIT); 359 if (priv->links[linkNum] == NULL) 360 return (ENOMEM); 361 bzero(priv->links[linkNum], sizeof(*priv->links[linkNum])); 362 priv->links[linkNum]->hook = hook; 363 LINK_NUM(hook) = linkNum; 364 priv->numLinks++; 365 return (0); 366 } 367 368 /* Unknown hook name */ 369 return (EINVAL); 370 } 371 372 /* 373 * Receive a control message 374 */ 375 static int 376 ng_bridge_rcvmsg(node_p node, struct ng_mesg *msg, 377 const char *retaddr, struct ng_mesg **rptr) 378 { 379 const priv_p priv = node->private; 380 struct ng_mesg *resp = NULL; 381 int error = 0; 382 383 switch (msg->header.typecookie) { 384 case NGM_BRIDGE_COOKIE: 385 switch (msg->header.cmd) { 386 case NGM_BRIDGE_GET_CONFIG: 387 { 388 struct ng_bridge_config *conf; 389 390 NG_MKRESPONSE(resp, msg, 391 sizeof(struct ng_bridge_config), M_NOWAIT); 392 if (resp == NULL) { 393 error = ENOMEM; 394 break; 395 } 396 conf = (struct ng_bridge_config *)resp->data; 397 *conf = priv->conf; /* no sanity checking needed */ 398 break; 399 } 400 case NGM_BRIDGE_SET_CONFIG: 401 { 402 struct ng_bridge_config *conf; 403 int i; 404 405 if (msg->header.arglen 406 != sizeof(struct ng_bridge_config)) { 407 error = EINVAL; 408 break; 409 } 410 conf = (struct ng_bridge_config *)msg->data; 411 priv->conf = *conf; 412 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) 413 priv->conf.ipfw[i] = !!priv->conf.ipfw[i]; 414 break; 415 } 416 case NGM_BRIDGE_RESET: 417 { 418 int i; 419 420 /* Flush all entries in the hash table */ 421 ng_bridge_remove_hosts(priv, -1); 422 423 /* Reset all loop detection counters and stats */ 424 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) { 425 if (priv->links[i] == NULL) 426 continue; 427 priv->links[i]->loopCount = 0; 428 bzero(&priv->links[i]->stats, 429 sizeof(priv->links[i]->stats)); 430 } 431 break; 432 } 433 case NGM_BRIDGE_GET_STATS: 434 case NGM_BRIDGE_CLR_STATS: 435 case NGM_BRIDGE_GETCLR_STATS: 436 { 437 struct ng_bridge_link *link; 438 int linkNum; 439 440 /* Get link number */ 441 if (msg->header.arglen != sizeof(u_int32_t)) { 442 error = EINVAL; 443 break; 444 } 445 linkNum = *((u_int32_t *)msg->data); 446 if (linkNum < 0 || linkNum >= NG_BRIDGE_MAX_LINKS) { 447 error = EINVAL; 448 break; 449 } 450 if ((link = priv->links[linkNum]) == NULL) { 451 error = ENOTCONN; 452 break; 453 } 454 455 /* Get/clear stats */ 456 if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) { 457 NG_MKRESPONSE(resp, msg, 458 sizeof(link->stats), M_NOWAIT); 459 if (resp == NULL) { 460 error = ENOMEM; 461 break; 462 } 463 bcopy(&link->stats, 464 resp->data, sizeof(link->stats)); 465 } 466 if (msg->header.cmd != NGM_BRIDGE_GET_STATS) 467 bzero(&link->stats, sizeof(link->stats)); 468 break; 469 } 470 case NGM_BRIDGE_GET_TABLE: 471 { 472 struct ng_bridge_host_ary *ary; 473 struct ng_bridge_hent *hent; 474 int i = 0, bucket; 475 476 NG_MKRESPONSE(resp, msg, sizeof(*ary) 477 + (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT); 478 if (resp == NULL) { 479 error = ENOMEM; 480 break; 481 } 482 ary = (struct ng_bridge_host_ary *)resp->data; 483 ary->numHosts = priv->numHosts; 484 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 485 SLIST_FOREACH(hent, &priv->tab[bucket], next) 486 ary->hosts[i++] = hent->host; 487 } 488 break; 489 } 490 default: 491 error = EINVAL; 492 break; 493 } 494 break; 495 default: 496 error = EINVAL; 497 break; 498 } 499 500 /* Done */ 501 if (rptr) 502 *rptr = resp; 503 else if (resp != NULL) 504 FREE(resp, M_NETGRAPH); 505 FREE(msg, M_NETGRAPH); 506 return (error); 507 } 508 509 /* 510 * Receive data on a hook 511 */ 512 static int 513 ng_bridge_rcvdata(hook_p hook, struct mbuf *m, meta_p meta) 514 { 515 const node_p node = hook->node; 516 const priv_p priv = node->private; 517 struct ng_bridge_host *host; 518 struct ng_bridge_link *link; 519 struct ether_header *eh; 520 int error = 0, linkNum, linksSeen; 521 int manycast; 522 struct ng_bridge_link *firstLink; 523 524 /* Get link number */ 525 linkNum = LINK_NUM(hook); 526 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 527 ("%s: linkNum=%u", __FUNCTION__, linkNum)); 528 link = priv->links[linkNum]; 529 KASSERT(link != NULL, ("%s: link%d null", __FUNCTION__, linkNum)); 530 531 /* Sanity check packet and pull up header */ 532 if (m->m_pkthdr.len < ETHER_HDR_LEN) { 533 link->stats.recvRunts++; 534 NG_FREE_DATA(m, meta); 535 return (EINVAL); 536 } 537 if (m->m_len < ETHER_HDR_LEN && !(m = m_pullup(m, ETHER_HDR_LEN))) { 538 link->stats.memoryFailures++; 539 NG_FREE_META(meta); 540 return (ENOBUFS); 541 } 542 eh = mtod(m, struct ether_header *); 543 if ((eh->ether_shost[0] & 1) != 0) { 544 link->stats.recvInvalid++; 545 NG_FREE_DATA(m, meta); 546 return (EINVAL); 547 } 548 549 /* Is link disabled due to a loopback condition? */ 550 if (link->loopCount != 0) { 551 link->stats.loopDrops++; 552 NG_FREE_DATA(m, meta); 553 return (ELOOP); /* XXX is this an appropriate error? */ 554 } 555 556 /* Update stats */ 557 link->stats.recvPackets++; 558 link->stats.recvOctets += m->m_pkthdr.len; 559 if ((manycast = (eh->ether_dhost[0] & 1)) != 0) { 560 if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) { 561 link->stats.recvBroadcasts++; 562 manycast = 2; 563 } else 564 link->stats.recvMulticasts++; 565 } 566 567 /* Look up packet's source Ethernet address in hashtable */ 568 if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) { 569 570 /* Update time since last heard from this host */ 571 host->staleness = 0; 572 573 /* Did host jump to a different link? */ 574 if (host->linkNum != linkNum) { 575 576 /* 577 * If the host's old link was recently established 578 * on the old link and it's already jumped to a new 579 * link, declare a loopback condition. 580 */ 581 if (host->age < priv->conf.minStableAge) { 582 583 /* Log the problem */ 584 if (priv->conf.debugLevel >= 2) { 585 struct ifnet *ifp = m->m_pkthdr.rcvif; 586 char suffix[32]; 587 588 if (ifp != NULL) 589 snprintf(suffix, sizeof(suffix), 590 " (%s%d)", ifp->if_name, 591 ifp->if_unit); 592 else 593 *suffix = '\0'; 594 log(LOG_WARNING, "ng_bridge: %s:" 595 " loopback detected on %s%s\n", 596 ng_bridge_nodename(node), 597 hook->name, suffix); 598 } 599 600 /* Mark link as linka non grata */ 601 link->loopCount = priv->conf.loopTimeout; 602 link->stats.loopDetects++; 603 604 /* Forget all hosts on this link */ 605 ng_bridge_remove_hosts(priv, linkNum); 606 607 /* Drop packet */ 608 link->stats.loopDrops++; 609 NG_FREE_DATA(m, meta); 610 return (ELOOP); /* XXX appropriate? */ 611 } 612 613 /* Move host over to new link */ 614 host->linkNum = linkNum; 615 host->age = 0; 616 } 617 } else { 618 if (!ng_bridge_put(priv, eh->ether_shost, linkNum)) { 619 link->stats.memoryFailures++; 620 NG_FREE_DATA(m, meta); 621 return (ENOMEM); 622 } 623 } 624 625 /* Run packet through ipfw processing, if enabled */ 626 if (priv->conf.ipfw[linkNum] && fw_enable && ip_fw_chk_ptr != NULL) { 627 /* XXX not implemented yet */ 628 } 629 630 /* 631 * If unicast and destination host known, deliver to host's link, 632 * unless it is the same link as the packet came in on. 633 */ 634 if (!manycast) { 635 636 /* Determine packet destination link */ 637 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) { 638 struct ng_bridge_link *const destLink 639 = priv->links[host->linkNum]; 640 641 /* If destination same as incoming link, do nothing */ 642 KASSERT(destLink != NULL, 643 ("%s: link%d null", __FUNCTION__, host->linkNum)); 644 if (destLink == link) { 645 NG_FREE_DATA(m, meta); 646 return (0); 647 } 648 649 /* Deliver packet out the destination link */ 650 destLink->stats.xmitPackets++; 651 destLink->stats.xmitOctets += m->m_pkthdr.len; 652 NG_SEND_DATA(error, destLink->hook, m, meta); 653 return (error); 654 } 655 656 /* Destination host is not known */ 657 link->stats.recvUnknown++; 658 } 659 660 /* Distribute unknown, multicast, broadcast pkts to all other links */ 661 firstLink = NULL; 662 for (linkNum = linksSeen = 0; linksSeen <= priv->numLinks; linkNum++) { 663 struct ng_bridge_link *destLink; 664 meta_p meta2 = NULL; 665 struct mbuf *m2 = NULL; 666 667 /* 668 * If we have checked all the links then now 669 * send the original on its reserved link 670 */ 671 if (linksSeen == priv->numLinks) { 672 /* If we never saw a good link, leave. */ 673 if (firstLink == NULL) { 674 NG_FREE_DATA(m, meta); 675 return (0); 676 } 677 destLink = firstLink; 678 } else { 679 destLink = priv->links[linkNum]; 680 if (destLink != NULL) 681 linksSeen++; 682 /* Skip incoming link and disconnected links */ 683 if (destLink == NULL || destLink == link) { 684 continue; 685 } 686 if (firstLink == NULL) { 687 /* 688 * This is the first usable link we have found. 689 * Reserve it for the originals. 690 * If we never find another we save a copy. 691 */ 692 firstLink = destLink; 693 continue; 694 } 695 696 /* 697 * It's usable link but not the reserved (first) one. 698 * Copy mbuf and meta info for sending. 699 */ 700 m2 = m_dup(m, M_NOWAIT); /* XXX m_copypacket() */ 701 if (m2 == NULL) { 702 link->stats.memoryFailures++; 703 NG_FREE_DATA(m, meta); 704 return (ENOBUFS); 705 } 706 if (meta != NULL 707 && (meta2 = ng_copy_meta(meta)) == NULL) { 708 link->stats.memoryFailures++; 709 m_freem(m2); 710 NG_FREE_DATA(m, meta); 711 return (ENOMEM); 712 } 713 } 714 715 /* Update stats */ 716 destLink->stats.xmitPackets++; 717 destLink->stats.xmitOctets += m->m_pkthdr.len; 718 switch (manycast) { 719 case 0: /* unicast */ 720 break; 721 case 1: /* multicast */ 722 destLink->stats.xmitMulticasts++; 723 break; 724 case 2: /* broadcast */ 725 destLink->stats.xmitBroadcasts++; 726 break; 727 } 728 729 /* Send packet */ 730 if (destLink == firstLink) { 731 /* 732 * If we've sent all the others, send the original 733 * on the first link we found. 734 */ 735 NG_SEND_DATA(error, destLink->hook, m, meta); 736 break; /* always done last - not really needed. */ 737 } else { 738 NG_SEND_DATA(error, destLink->hook, m2, meta2); 739 } 740 } 741 return (error); 742 } 743 744 /* 745 * Shutdown node 746 */ 747 static int 748 ng_bridge_rmnode(node_p node) 749 { 750 const priv_p priv = node->private; 751 752 /* 753 * Shut down everything except the timer. There's no way to 754 * avoid another possible timeout event (it may have already 755 * been dequeued), so we can't free the node yet. 756 */ 757 ng_unname(node); 758 ng_cutlinks(node); /* frees all link and host info */ 759 KASSERT(priv->numLinks == 0 && priv->numHosts == 0, 760 ("%s: numLinks=%d numHosts=%d", 761 __FUNCTION__, priv->numLinks, priv->numHosts)); 762 FREE(priv->tab, M_NETGRAPH); 763 764 /* NG_INVALID flag is now set so node will be freed at next timeout */ 765 return (0); 766 } 767 768 /* 769 * Hook disconnection. 770 */ 771 static int 772 ng_bridge_disconnect(hook_p hook) 773 { 774 const priv_p priv = hook->node->private; 775 int linkNum; 776 777 /* Get link number */ 778 linkNum = LINK_NUM(hook); 779 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 780 ("%s: linkNum=%u", __FUNCTION__, linkNum)); 781 782 /* Remove all hosts associated with this link */ 783 ng_bridge_remove_hosts(priv, linkNum); 784 785 /* Free associated link information */ 786 KASSERT(priv->links[linkNum] != NULL, ("%s: no link", __FUNCTION__)); 787 FREE(priv->links[linkNum], M_NETGRAPH); 788 priv->links[linkNum] = NULL; 789 priv->numLinks--; 790 791 /* If no more hooks, go away */ 792 if (hook->node->numhooks == 0) 793 ng_rmnode(hook->node); 794 return (0); 795 } 796 797 /****************************************************************** 798 HASH TABLE FUNCTIONS 799 ******************************************************************/ 800 801 /* 802 * Hash algorithm 803 * 804 * Only hashing bytes 3-6 of the Ethernet address is sufficient and fast. 805 */ 806 #define HASH(addr,mask) ( (((const u_int16_t *)(addr))[0] \ 807 ^ ((const u_int16_t *)(addr))[1] \ 808 ^ ((const u_int16_t *)(addr))[2]) & (mask) ) 809 810 /* 811 * Find a host entry in the table. 812 */ 813 static struct ng_bridge_host * 814 ng_bridge_get(priv_p priv, const u_char *addr) 815 { 816 const int bucket = HASH(addr, priv->hashMask); 817 struct ng_bridge_hent *hent; 818 819 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 820 if (ETHER_EQUAL(hent->host.addr, addr)) 821 return (&hent->host); 822 } 823 return (NULL); 824 } 825 826 /* 827 * Add a new host entry to the table. This assumes the host doesn't 828 * already exist in the table. Returns 1 on success, 0 if there 829 * was a memory allocation failure. 830 */ 831 static int 832 ng_bridge_put(priv_p priv, const u_char *addr, int linkNum) 833 { 834 const int bucket = HASH(addr, priv->hashMask); 835 struct ng_bridge_hent *hent; 836 837 #ifdef INVARIANTS 838 /* Assert that entry does not already exist in hashtable */ 839 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 840 KASSERT(!ETHER_EQUAL(hent->host.addr, addr), 841 ("%s: entry %6D exists in table", __FUNCTION__, addr, ":")); 842 } 843 #endif 844 845 /* Allocate and initialize new hashtable entry */ 846 MALLOC(hent, struct ng_bridge_hent *, 847 sizeof(*hent), M_NETGRAPH, M_NOWAIT); 848 if (hent == NULL) 849 return (0); 850 bcopy(addr, hent->host.addr, ETHER_ADDR_LEN); 851 hent->host.linkNum = linkNum; 852 hent->host.staleness = 0; 853 hent->host.age = 0; 854 855 /* Add new element to hash bucket */ 856 SLIST_INSERT_HEAD(&priv->tab[bucket], hent, next); 857 priv->numHosts++; 858 859 /* Resize table if necessary */ 860 ng_bridge_rehash(priv); 861 return (1); 862 } 863 864 /* 865 * Resize the hash table. We try to maintain the number of buckets 866 * such that the load factor is in the range 0.25 to 1.0. 867 * 868 * If we can't get the new memory then we silently fail. This is OK 869 * because things will still work and we'll try again soon anyway. 870 */ 871 static void 872 ng_bridge_rehash(priv_p priv) 873 { 874 struct ng_bridge_bucket *newTab; 875 int oldBucket, newBucket; 876 int newNumBuckets; 877 u_int newMask; 878 879 /* Is table too full or too empty? */ 880 if (priv->numHosts > priv->numBuckets 881 && (priv->numBuckets << 1) <= MAX_BUCKETS) 882 newNumBuckets = priv->numBuckets << 1; 883 else if (priv->numHosts < (priv->numBuckets >> 2) 884 && (priv->numBuckets >> 2) >= MIN_BUCKETS) 885 newNumBuckets = priv->numBuckets >> 2; 886 else 887 return; 888 newMask = newNumBuckets - 1; 889 890 /* Allocate and initialize new table */ 891 MALLOC(newTab, struct ng_bridge_bucket *, 892 newNumBuckets * sizeof(*newTab), M_NETGRAPH, M_NOWAIT); 893 if (newTab == NULL) 894 return; 895 bzero(newTab, newNumBuckets * sizeof(*newTab)); 896 897 /* Move all entries from old table to new table */ 898 for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) { 899 struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket]; 900 901 while (!SLIST_EMPTY(oldList)) { 902 struct ng_bridge_hent *const hent 903 = SLIST_FIRST(oldList); 904 905 SLIST_REMOVE_HEAD(oldList, next); 906 newBucket = HASH(hent->host.addr, newMask); 907 SLIST_INSERT_HEAD(&newTab[newBucket], hent, next); 908 } 909 } 910 911 /* Replace old table with new one */ 912 if (priv->conf.debugLevel >= 3) { 913 log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n", 914 ng_bridge_nodename(priv->node), 915 priv->numBuckets, newNumBuckets); 916 } 917 FREE(priv->tab, M_NETGRAPH); 918 priv->numBuckets = newNumBuckets; 919 priv->hashMask = newMask; 920 priv->tab = newTab; 921 return; 922 } 923 924 /****************************************************************** 925 MISC FUNCTIONS 926 ******************************************************************/ 927 928 /* 929 * Remove all hosts associated with a specific link from the hashtable. 930 * If linkNum == -1, then remove all hosts in the table. 931 */ 932 static void 933 ng_bridge_remove_hosts(priv_p priv, int linkNum) 934 { 935 int bucket; 936 937 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 938 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 939 940 while (*hptr != NULL) { 941 struct ng_bridge_hent *const hent = *hptr; 942 943 if (linkNum == -1 || hent->host.linkNum == linkNum) { 944 *hptr = SLIST_NEXT(hent, next); 945 FREE(hent, M_NETGRAPH); 946 priv->numHosts--; 947 } else 948 hptr = &SLIST_NEXT(hent, next); 949 } 950 } 951 } 952 953 /* 954 * Handle our once-per-second timeout event. We do two things: 955 * we decrement link->loopCount for those links being muted due to 956 * a detected loopback condition, and we remove any hosts from 957 * the hashtable whom we haven't heard from in a long while. 958 * 959 * If the node has the NG_INVALID flag set, our job is to kill it. 960 */ 961 static void 962 ng_bridge_timeout(void *arg) 963 { 964 const node_p node = arg; 965 const priv_p priv = node->private; 966 int s, bucket; 967 int counter = 0; 968 int linkNum; 969 970 /* If node was shut down, this is the final lingering timeout */ 971 s = splnet(); 972 if ((node->flags & NG_INVALID) != 0) { 973 FREE(priv, M_NETGRAPH); 974 node->private = NULL; 975 ng_unref(node); 976 splx(s); 977 return; 978 } 979 980 /* Register a new timeout, keeping the existing node reference */ 981 callout_reset(&priv->timer, hz, ng_bridge_timeout, node); 982 983 /* Update host time counters and remove stale entries */ 984 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 985 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 986 987 while (*hptr != NULL) { 988 struct ng_bridge_hent *const hent = *hptr; 989 990 /* Make sure host's link really exists */ 991 KASSERT(priv->links[hent->host.linkNum] != NULL, 992 ("%s: host %6D on nonexistent link %d\n", 993 __FUNCTION__, hent->host.addr, ":", 994 hent->host.linkNum)); 995 996 /* Remove hosts we haven't heard from in a while */ 997 if (++hent->host.staleness >= priv->conf.maxStaleness) { 998 *hptr = SLIST_NEXT(hent, next); 999 FREE(hent, M_NETGRAPH); 1000 priv->numHosts--; 1001 } else { 1002 if (hent->host.age < 0xffff) 1003 hent->host.age++; 1004 hptr = &SLIST_NEXT(hent, next); 1005 counter++; 1006 } 1007 } 1008 } 1009 KASSERT(priv->numHosts == counter, 1010 ("%s: hosts: %d != %d", __FUNCTION__, priv->numHosts, counter)); 1011 1012 /* Decrease table size if necessary */ 1013 ng_bridge_rehash(priv); 1014 1015 /* Decrease loop counter on muted looped back links */ 1016 for (counter = linkNum = 0; linkNum < NG_BRIDGE_MAX_LINKS; linkNum++) { 1017 struct ng_bridge_link *const link = priv->links[linkNum]; 1018 1019 if (link != NULL) { 1020 if (link->loopCount != 0) { 1021 link->loopCount--; 1022 if (link->loopCount == 0 1023 && priv->conf.debugLevel >= 2) { 1024 log(LOG_INFO, "ng_bridge: %s:" 1025 " restoring looped back link%d\n", 1026 ng_bridge_nodename(node), linkNum); 1027 } 1028 } 1029 counter++; 1030 } 1031 } 1032 KASSERT(priv->numLinks == counter, 1033 ("%s: links: %d != %d", __FUNCTION__, priv->numLinks, counter)); 1034 1035 /* Done */ 1036 splx(s); 1037 } 1038 1039 /* 1040 * Return node's "name", even if it doesn't have one. 1041 */ 1042 static const char * 1043 ng_bridge_nodename(node_p node) 1044 { 1045 static char name[NG_NODELEN+1]; 1046 1047 if (node->name != NULL) 1048 snprintf(name, sizeof(name), "%s", node->name); 1049 else 1050 snprintf(name, sizeof(name), "[%x]", ng_node2ID(node)); 1051 return name; 1052 } 1053
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