ng_bridge.c revision 70700
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: head/sys/netgraph/ng_bridge.c 70700 2001-01-06 00:46:47Z julian $ 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#include <netgraph/ng_ether.h> 81 82/* Per-link private data */ 83struct ng_bridge_link { 84 hook_p hook; /* netgraph hook */ 85 u_int16_t loopCount; /* loop ignore timer */ 86 struct ng_bridge_link_stats stats; /* link stats */ 87}; 88 89/* Per-node private data */ 90struct ng_bridge_private { 91 struct ng_bridge_bucket *tab; /* hash table bucket array */ 92 struct ng_bridge_link *links[NG_BRIDGE_MAX_LINKS]; 93 struct ng_bridge_config conf; /* node configuration */ 94 node_p node; /* netgraph node */ 95 u_int numHosts; /* num entries in table */ 96 u_int numBuckets; /* num buckets in table */ 97 u_int hashMask; /* numBuckets - 1 */ 98 int numLinks; /* num connected links */ 99 struct callout timer; /* one second periodic timer */ 100}; 101typedef struct ng_bridge_private *priv_p; 102 103/* Information about a host, stored in a hash table entry */ 104struct ng_bridge_hent { 105 struct ng_bridge_host host; /* actual host info */ 106 SLIST_ENTRY(ng_bridge_hent) next; /* next entry in bucket */ 107}; 108 109/* Hash table bucket declaration */ 110SLIST_HEAD(ng_bridge_bucket, ng_bridge_hent); 111 112/* Netgraph node methods */ 113static ng_constructor_t ng_bridge_constructor; 114static ng_rcvmsg_t ng_bridge_rcvmsg; 115static ng_shutdown_t ng_bridge_shutdown; 116static ng_newhook_t ng_bridge_newhook; 117static ng_rcvdata_t ng_bridge_rcvdata; 118static ng_disconnect_t ng_bridge_disconnect; 119 120/* Other internal functions */ 121static struct ng_bridge_host *ng_bridge_get(priv_p priv, const u_char *addr); 122static int ng_bridge_put(priv_p priv, const u_char *addr, int linkNum); 123static void ng_bridge_rehash(priv_p priv); 124static void ng_bridge_remove_hosts(priv_p priv, int linkNum); 125static void ng_bridge_timeout(void *arg); 126static const char *ng_bridge_nodename(node_p node); 127 128/* Ethernet broadcast */ 129static const u_char ng_bridge_bcast_addr[ETHER_ADDR_LEN] = 130 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; 131 132/* Store each hook's link number in the private field */ 133#define LINK_NUM(hook) (*(u_int16_t *)(&(hook)->private)) 134 135/* Compare Ethernet addresses using 32 and 16 bit words instead of bytewise */ 136#define ETHER_EQUAL(a,b) (((const u_int32_t *)(a))[0] \ 137 == ((const u_int32_t *)(b))[0] \ 138 && ((const u_int16_t *)(a))[2] \ 139 == ((const u_int16_t *)(b))[2]) 140 141/* Minimum and maximum number of hash buckets. Must be a power of two. */ 142#define MIN_BUCKETS (1 << 5) /* 32 */ 143#define MAX_BUCKETS (1 << 14) /* 16384 */ 144 145/* Configuration default values */ 146#define DEFAULT_LOOP_TIMEOUT 60 147#define DEFAULT_MAX_STALENESS (15 * 60) /* same as ARP timeout */ 148#define DEFAULT_MIN_STABLE_AGE 1 149 150/****************************************************************** 151 NETGRAPH PARSE TYPES 152******************************************************************/ 153 154/* 155 * How to determine the length of the table returned by NGM_BRIDGE_GET_TABLE 156 */ 157static int 158ng_bridge_getTableLength(const struct ng_parse_type *type, 159 const u_char *start, const u_char *buf) 160{ 161 const struct ng_bridge_host_ary *const hary 162 = (const struct ng_bridge_host_ary *)(buf - sizeof(u_int32_t)); 163 164 return hary->numHosts; 165} 166 167/* Parse type for struct ng_bridge_host_ary */ 168static const struct ng_parse_struct_info ng_bridge_host_type_info 169 = NG_BRIDGE_HOST_TYPE_INFO(&ng_ether_enaddr_type); 170static const struct ng_parse_type ng_bridge_host_type = { 171 &ng_parse_struct_type, 172 &ng_bridge_host_type_info 173}; 174static const struct ng_parse_array_info ng_bridge_hary_type_info = { 175 &ng_bridge_host_type, 176 ng_bridge_getTableLength 177}; 178static const struct ng_parse_type ng_bridge_hary_type = { 179 &ng_parse_array_type, 180 &ng_bridge_hary_type_info 181}; 182static const struct ng_parse_struct_info ng_bridge_host_ary_type_info 183 = NG_BRIDGE_HOST_ARY_TYPE_INFO(&ng_bridge_hary_type); 184static const struct ng_parse_type ng_bridge_host_ary_type = { 185 &ng_parse_struct_type, 186 &ng_bridge_host_ary_type_info 187}; 188 189/* Parse type for struct ng_bridge_config */ 190static const struct ng_parse_fixedarray_info ng_bridge_ipfwary_type_info = { 191 &ng_parse_uint8_type, 192 NG_BRIDGE_MAX_LINKS 193}; 194static const struct ng_parse_type ng_bridge_ipfwary_type = { 195 &ng_parse_fixedarray_type, 196 &ng_bridge_ipfwary_type_info 197}; 198static const struct ng_parse_struct_info ng_bridge_config_type_info 199 = NG_BRIDGE_CONFIG_TYPE_INFO(&ng_bridge_ipfwary_type); 200static const struct ng_parse_type ng_bridge_config_type = { 201 &ng_parse_struct_type, 202 &ng_bridge_config_type_info 203}; 204 205/* Parse type for struct ng_bridge_link_stat */ 206static const struct ng_parse_struct_info 207 ng_bridge_stats_type_info = NG_BRIDGE_STATS_TYPE_INFO; 208static const struct ng_parse_type ng_bridge_stats_type = { 209 &ng_parse_struct_type, 210 &ng_bridge_stats_type_info 211}; 212 213/* List of commands and how to convert arguments to/from ASCII */ 214static const struct ng_cmdlist ng_bridge_cmdlist[] = { 215 { 216 NGM_BRIDGE_COOKIE, 217 NGM_BRIDGE_SET_CONFIG, 218 "setconfig", 219 &ng_bridge_config_type, 220 NULL 221 }, 222 { 223 NGM_BRIDGE_COOKIE, 224 NGM_BRIDGE_GET_CONFIG, 225 "getconfig", 226 NULL, 227 &ng_bridge_config_type 228 }, 229 { 230 NGM_BRIDGE_COOKIE, 231 NGM_BRIDGE_RESET, 232 "reset", 233 NULL, 234 NULL 235 }, 236 { 237 NGM_BRIDGE_COOKIE, 238 NGM_BRIDGE_GET_STATS, 239 "getstats", 240 &ng_parse_uint32_type, 241 &ng_bridge_stats_type 242 }, 243 { 244 NGM_BRIDGE_COOKIE, 245 NGM_BRIDGE_CLR_STATS, 246 "clrstats", 247 &ng_parse_uint32_type, 248 NULL 249 }, 250 { 251 NGM_BRIDGE_COOKIE, 252 NGM_BRIDGE_GETCLR_STATS, 253 "getclrstats", 254 &ng_parse_uint32_type, 255 &ng_bridge_stats_type 256 }, 257 { 258 NGM_BRIDGE_COOKIE, 259 NGM_BRIDGE_GET_TABLE, 260 "gettable", 261 NULL, 262 &ng_bridge_host_ary_type 263 }, 264 { 0 } 265}; 266 267/* Node type descriptor */ 268static struct ng_type ng_bridge_typestruct = { 269 NG_ABI_VERSION, 270 NG_BRIDGE_NODE_TYPE, 271 NULL, 272 ng_bridge_constructor, 273 ng_bridge_rcvmsg, 274 ng_bridge_shutdown, 275 ng_bridge_newhook, 276 NULL, 277 NULL, 278 ng_bridge_rcvdata, 279 ng_bridge_disconnect, 280 ng_bridge_cmdlist, 281}; 282NETGRAPH_INIT(bridge, &ng_bridge_typestruct); 283 284/* Depend on ng_ether so we can use the Ethernet parse type */ 285MODULE_DEPEND(ng_bridge, ng_ether, 1, 1, 1); 286 287/****************************************************************** 288 NETGRAPH NODE METHODS 289******************************************************************/ 290 291/* 292 * Node constructor 293 */ 294static int 295ng_bridge_constructor(node_p node) 296{ 297 priv_p priv; 298 299 /* Allocate and initialize private info */ 300 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO); 301 if (priv == NULL) 302 return (ENOMEM); 303 callout_init(&priv->timer, 0); 304 305 /* Allocate and initialize hash table, etc. */ 306 MALLOC(priv->tab, struct ng_bridge_bucket *, 307 MIN_BUCKETS * sizeof(*priv->tab), M_NETGRAPH, M_NOWAIT | M_ZERO); 308 if (priv->tab == NULL) { 309 FREE(priv, M_NETGRAPH); 310 return (ENOMEM); 311 } 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 /* 320 * This node has all kinds of stuff that could be screwed by SMP. 321 * Until it gets it's own internal protection, we go through in 322 * single file. This could hurt a machine bridging beteen two 323 * GB ethernets so it should be fixed. 324 * When it's fixed the process SHOULD NOT SLEEP, spinlocks please! 325 * (and atomic ops ) 326 */ 327 node->flags |= NG_FORCE_WRITER; 328 node->private = priv; 329 priv->node = node; 330 331 /* Start timer by faking a timeout event */ 332 node->refs++; /* XXX ???? because of the timeout?*/ 333 ng_bridge_timeout(node); 334 return (0); 335} 336 337/* 338 * Method for attaching a new hook 339 */ 340static int 341ng_bridge_newhook(node_p node, hook_p hook, const char *name) 342{ 343 const priv_p priv = node->private; 344 345 /* Check for a link hook */ 346 if (strncmp(name, NG_BRIDGE_HOOK_LINK_PREFIX, 347 strlen(NG_BRIDGE_HOOK_LINK_PREFIX)) == 0) { 348 const char *cp; 349 char *eptr; 350 u_long linkNum; 351 352 cp = name + strlen(NG_BRIDGE_HOOK_LINK_PREFIX); 353 if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0')) 354 return (EINVAL); 355 linkNum = strtoul(cp, &eptr, 10); 356 if (*eptr != '\0' || linkNum >= NG_BRIDGE_MAX_LINKS) 357 return (EINVAL); 358 if (priv->links[linkNum] != NULL) 359 return (EISCONN); 360 MALLOC(priv->links[linkNum], struct ng_bridge_link *, 361 sizeof(*priv->links[linkNum]), M_NETGRAPH, M_NOWAIT|M_ZERO); 362 if (priv->links[linkNum] == NULL) 363 return (ENOMEM); 364 priv->links[linkNum]->hook = hook; 365 LINK_NUM(hook) = linkNum; 366 priv->numLinks++; 367 return (0); 368 } 369 370 /* Unknown hook name */ 371 return (EINVAL); 372} 373 374/* 375 * Receive a control message 376 */ 377static int 378ng_bridge_rcvmsg(node_p node, item_p item, hook_p lasthook) 379{ 380 const priv_p priv = node->private; 381 struct ng_mesg *resp = NULL; 382 int error = 0; 383 struct ng_mesg *msg; 384 385 NGI_GET_MSG(item, msg); 386 switch (msg->header.typecookie) { 387 case NGM_BRIDGE_COOKIE: 388 switch (msg->header.cmd) { 389 case NGM_BRIDGE_GET_CONFIG: 390 { 391 struct ng_bridge_config *conf; 392 393 NG_MKRESPONSE(resp, msg, 394 sizeof(struct ng_bridge_config), M_NOWAIT); 395 if (resp == NULL) { 396 error = ENOMEM; 397 break; 398 } 399 conf = (struct ng_bridge_config *)resp->data; 400 *conf = priv->conf; /* no sanity checking needed */ 401 break; 402 } 403 case NGM_BRIDGE_SET_CONFIG: 404 { 405 struct ng_bridge_config *conf; 406 int i; 407 408 if (msg->header.arglen 409 != sizeof(struct ng_bridge_config)) { 410 error = EINVAL; 411 break; 412 } 413 conf = (struct ng_bridge_config *)msg->data; 414 priv->conf = *conf; 415 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) 416 priv->conf.ipfw[i] = !!priv->conf.ipfw[i]; 417 break; 418 } 419 case NGM_BRIDGE_RESET: 420 { 421 int i; 422 423 /* Flush all entries in the hash table */ 424 ng_bridge_remove_hosts(priv, -1); 425 426 /* Reset all loop detection counters and stats */ 427 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) { 428 if (priv->links[i] == NULL) 429 continue; 430 priv->links[i]->loopCount = 0; 431 bzero(&priv->links[i]->stats, 432 sizeof(priv->links[i]->stats)); 433 } 434 break; 435 } 436 case NGM_BRIDGE_GET_STATS: 437 case NGM_BRIDGE_CLR_STATS: 438 case NGM_BRIDGE_GETCLR_STATS: 439 { 440 struct ng_bridge_link *link; 441 int linkNum; 442 443 /* Get link number */ 444 if (msg->header.arglen != sizeof(u_int32_t)) { 445 error = EINVAL; 446 break; 447 } 448 linkNum = *((u_int32_t *)msg->data); 449 if (linkNum < 0 || linkNum >= NG_BRIDGE_MAX_LINKS) { 450 error = EINVAL; 451 break; 452 } 453 if ((link = priv->links[linkNum]) == NULL) { 454 error = ENOTCONN; 455 break; 456 } 457 458 /* Get/clear stats */ 459 if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) { 460 NG_MKRESPONSE(resp, msg, 461 sizeof(link->stats), M_NOWAIT); 462 if (resp == NULL) { 463 error = ENOMEM; 464 break; 465 } 466 bcopy(&link->stats, 467 resp->data, sizeof(link->stats)); 468 } 469 if (msg->header.cmd != NGM_BRIDGE_GET_STATS) 470 bzero(&link->stats, sizeof(link->stats)); 471 break; 472 } 473 case NGM_BRIDGE_GET_TABLE: 474 { 475 struct ng_bridge_host_ary *ary; 476 struct ng_bridge_hent *hent; 477 int i = 0, bucket; 478 479 NG_MKRESPONSE(resp, msg, sizeof(*ary) 480 + (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT); 481 if (resp == NULL) { 482 error = ENOMEM; 483 break; 484 } 485 ary = (struct ng_bridge_host_ary *)resp->data; 486 ary->numHosts = priv->numHosts; 487 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 488 SLIST_FOREACH(hent, &priv->tab[bucket], next) 489 ary->hosts[i++] = hent->host; 490 } 491 break; 492 } 493 default: 494 error = EINVAL; 495 break; 496 } 497 break; 498 default: 499 error = EINVAL; 500 break; 501 } 502 503 /* Done */ 504 NG_RESPOND_MSG(error, node, item, resp); 505 NG_FREE_MSG(msg); 506 return (error); 507} 508 509/* 510 * Receive data on a hook 511 */ 512static int 513ng_bridge_rcvdata(hook_p hook, item_p item) 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; 521 int manycast; 522 struct mbuf *m; 523 meta_p meta; 524 struct ng_bridge_link *firstLink; 525 526 NGI_GET_M(item, m); 527 /* Get link number */ 528 linkNum = LINK_NUM(hook); 529 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 530 ("%s: linkNum=%u", __FUNCTION__, linkNum)); 531 link = priv->links[linkNum]; 532 KASSERT(link != NULL, ("%s: link%d null", __FUNCTION__, linkNum)); 533 534 /* Sanity check packet and pull up header */ 535 if (m->m_pkthdr.len < ETHER_HDR_LEN) { 536 link->stats.recvRunts++; 537 NG_FREE_ITEM(item); 538 NG_FREE_M(m); 539 return (EINVAL); 540 } 541 if (m->m_len < ETHER_HDR_LEN && !(m = m_pullup(m, ETHER_HDR_LEN))) { 542 link->stats.memoryFailures++; 543 NG_FREE_ITEM(item); 544 return (ENOBUFS); 545 } 546 eh = mtod(m, struct ether_header *); 547 if ((eh->ether_shost[0] & 1) != 0) { 548 link->stats.recvInvalid++; 549 NG_FREE_ITEM(item); 550 NG_FREE_M(m); 551 return (EINVAL); 552 } 553 554 /* Is link disabled due to a loopback condition? */ 555 if (link->loopCount != 0) { 556 link->stats.loopDrops++; 557 NG_FREE_ITEM(item); 558 NG_FREE_M(m); 559 return (ELOOP); /* XXX is this an appropriate error? */ 560 } 561 562 /* Update stats */ 563 link->stats.recvPackets++; 564 link->stats.recvOctets += m->m_pkthdr.len; 565 if ((manycast = (eh->ether_dhost[0] & 1)) != 0) { 566 if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) { 567 link->stats.recvBroadcasts++; 568 manycast = 2; 569 } else 570 link->stats.recvMulticasts++; 571 } 572 573 /* Look up packet's source Ethernet address in hashtable */ 574 if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) { 575 576 /* Update time since last heard from this host */ 577 host->staleness = 0; 578 579 /* Did host jump to a different link? */ 580 if (host->linkNum != linkNum) { 581 582 /* 583 * If the host's old link was recently established 584 * on the old link and it's already jumped to a new 585 * link, declare a loopback condition. 586 */ 587 if (host->age < priv->conf.minStableAge) { 588 589 /* Log the problem */ 590 if (priv->conf.debugLevel >= 2) { 591 struct ifnet *ifp = m->m_pkthdr.rcvif; 592 char suffix[32]; 593 594 if (ifp != NULL) 595 snprintf(suffix, sizeof(suffix), 596 " (%s%d)", ifp->if_name, 597 ifp->if_unit); 598 else 599 *suffix = '\0'; 600 log(LOG_WARNING, "ng_bridge: %s:" 601 " loopback detected on %s%s\n", 602 ng_bridge_nodename(node), 603 hook->name, suffix); 604 } 605 606 /* Mark link as linka non grata */ 607 link->loopCount = priv->conf.loopTimeout; 608 link->stats.loopDetects++; 609 610 /* Forget all hosts on this link */ 611 ng_bridge_remove_hosts(priv, linkNum); 612 613 /* Drop packet */ 614 link->stats.loopDrops++; 615 NG_FREE_ITEM(item); 616 NG_FREE_M(m); 617 return (ELOOP); /* XXX appropriate? */ 618 } 619 620 /* Move host over to new link */ 621 host->linkNum = linkNum; 622 host->age = 0; 623 } 624 } else { 625 if (!ng_bridge_put(priv, eh->ether_shost, linkNum)) { 626 link->stats.memoryFailures++; 627 NG_FREE_ITEM(item); 628 NG_FREE_M(m); 629 return (ENOMEM); 630 } 631 } 632 633 /* Run packet through ipfw processing, if enabled */ 634 if (priv->conf.ipfw[linkNum] && fw_enable && ip_fw_chk_ptr != NULL) { 635 /* XXX not implemented yet */ 636 } 637 638 /* 639 * If unicast and destination host known, deliver to host's link, 640 * unless it is the same link as the packet came in on. 641 */ 642 if (!manycast) { 643 644 /* Determine packet destination link */ 645 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) { 646 struct ng_bridge_link *const destLink 647 = priv->links[host->linkNum]; 648 649 /* If destination same as incoming link, do nothing */ 650 KASSERT(destLink != NULL, 651 ("%s: link%d null", __FUNCTION__, host->linkNum)); 652 if (destLink == link) { 653 NG_FREE_ITEM(item); 654 NG_FREE_M(m); 655 return (0); 656 } 657 658 /* Deliver packet out the destination link */ 659 destLink->stats.xmitPackets++; 660 destLink->stats.xmitOctets += m->m_pkthdr.len; 661 NG_FWD_NEW_DATA(error, item, destLink->hook, m); 662 return (error); 663 } 664 665 /* Destination host is not known */ 666 link->stats.recvUnknown++; 667 } 668 669 /* Distribute unknown, multicast, broadcast pkts to all other links */ 670 meta = NGI_META(item); /* peek.. */ 671 firstLink = NULL; 672 for (linkNum = 0; linkNum <= priv->numLinks; linkNum++) { 673 struct ng_bridge_link *destLink; 674 meta_p meta2 = NULL; 675 struct mbuf *m2 = NULL; 676 677 /* 678 * If we have checked all the links then now 679 * send the original on its reserved link 680 */ 681 if (linkNum == priv->numLinks) { 682 /* If we never saw a good link, leave. */ 683 if (firstLink == NULL) { 684 NG_FREE_ITEM(item); 685 NG_FREE_M(m); 686 return (0); 687 } 688 destLink = firstLink; 689 } else { 690 destLink = priv->links[linkNum]; 691 /* Skip incoming link and disconnected links */ 692 if (destLink == NULL || destLink == link) { 693 continue; 694 } 695 if (firstLink == NULL) { 696 /* 697 * This is the first usable link we have found. 698 * Reserve it for the originals. 699 * If we never find another we save a copy. 700 */ 701 firstLink = destLink; 702 continue; 703 } 704 705 /* 706 * It's usable link but not the reserved (first) one. 707 * Copy mbuf and meta info for sending. 708 */ 709 m2 = m_dup(m, M_NOWAIT); /* XXX m_copypacket() */ 710 if (m2 == NULL) { 711 link->stats.memoryFailures++; 712 NG_FREE_ITEM(item); 713 NG_FREE_M(m); 714 return (ENOBUFS); 715 } 716 if (meta != NULL 717 && (meta2 = ng_copy_meta(meta)) == NULL) { 718 link->stats.memoryFailures++; 719 m_freem(m2); 720 NG_FREE_ITEM(item); 721 NG_FREE_M(m); 722 return (ENOMEM); 723 } 724 } 725 726 /* Update stats */ 727 destLink->stats.xmitPackets++; 728 destLink->stats.xmitOctets += m->m_pkthdr.len; 729 switch (manycast) { 730 case 0: /* unicast */ 731 break; 732 case 1: /* multicast */ 733 destLink->stats.xmitMulticasts++; 734 break; 735 case 2: /* broadcast */ 736 destLink->stats.xmitBroadcasts++; 737 break; 738 } 739 740 /* Send packet */ 741 if (destLink == firstLink) { 742 /* 743 * If we've sent all the others, send the original 744 * on the first link we found. 745 */ 746 NG_FWD_NEW_DATA(error, item, destLink->hook, m); 747 break; /* always done last - not really needed. */ 748 } else { 749 NG_SEND_DATA(error, destLink->hook, m2, meta2); 750 } 751 } 752 return (error); 753} 754 755/* 756 * Shutdown node 757 */ 758static int 759ng_bridge_shutdown(node_p node) 760{ 761 const priv_p priv = node->private; 762 763 KASSERT(priv->numLinks == 0 && priv->numHosts == 0, 764 ("%s: numLinks=%d numHosts=%d", 765 __FUNCTION__, priv->numLinks, priv->numHosts)); 766 FREE(priv->tab, M_NETGRAPH); 767 FREE(priv, M_NETGRAPH); 768 node->private = NULL; 769 ng_unref(node); 770 return (0); 771} 772 773/* 774 * Hook disconnection. 775 */ 776static int 777ng_bridge_disconnect(hook_p hook) 778{ 779 const priv_p priv = hook->node->private; 780 int linkNum; 781 782 /* Get link number */ 783 linkNum = LINK_NUM(hook); 784 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 785 ("%s: linkNum=%u", __FUNCTION__, linkNum)); 786 787 /* Remove all hosts associated with this link */ 788 ng_bridge_remove_hosts(priv, linkNum); 789 790 /* Free associated link information */ 791 KASSERT(priv->links[linkNum] != NULL, ("%s: no link", __FUNCTION__)); 792 FREE(priv->links[linkNum], M_NETGRAPH); 793 priv->links[linkNum] = NULL; 794 priv->numLinks--; 795 796 /* If no more hooks, go away */ 797 if ((hook->node->numhooks == 0) 798 && (( hook->node->flags & NG_INVALID) == 0)) 799 ng_rmnode_self(hook->node); 800 return (0); 801} 802 803/****************************************************************** 804 HASH TABLE FUNCTIONS 805******************************************************************/ 806 807/* 808 * Hash algorithm 809 * 810 * Only hashing bytes 3-6 of the Ethernet address is sufficient and fast. 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 */ 819static struct ng_bridge_host * 820ng_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 */ 837static int 838ng_bridge_put(priv_p priv, const u_char *addr, int linkNum) 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", __FUNCTION__, addr, ":")); 848 } 849#endif 850 851 /* Allocate and initialize new hashtable entry */ 852 MALLOC(hent, struct ng_bridge_hent *, 853 sizeof(*hent), M_NETGRAPH, M_NOWAIT); 854 if (hent == NULL) 855 return (0); 856 bcopy(addr, hent->host.addr, ETHER_ADDR_LEN); 857 hent->host.linkNum = linkNum; 858 hent->host.staleness = 0; 859 hent->host.age = 0; 860 861 /* Add new element to hash bucket */ 862 SLIST_INSERT_HEAD(&priv->tab[bucket], hent, next); 863 priv->numHosts++; 864 865 /* Resize table if necessary */ 866 ng_bridge_rehash(priv); 867 return (1); 868} 869 870/* 871 * Resize the hash table. We try to maintain the number of buckets 872 * such that the load factor is in the range 0.25 to 1.0. 873 * 874 * If we can't get the new memory then we silently fail. This is OK 875 * because things will still work and we'll try again soon anyway. 876 */ 877static void 878ng_bridge_rehash(priv_p priv) 879{ 880 struct ng_bridge_bucket *newTab; 881 int oldBucket, newBucket; 882 int newNumBuckets; 883 u_int newMask; 884 885 /* Is table too full or too empty? */ 886 if (priv->numHosts > priv->numBuckets 887 && (priv->numBuckets << 1) <= MAX_BUCKETS) 888 newNumBuckets = priv->numBuckets << 1; 889 else if (priv->numHosts < (priv->numBuckets >> 2) 890 && (priv->numBuckets >> 2) >= MIN_BUCKETS) 891 newNumBuckets = priv->numBuckets >> 2; 892 else 893 return; 894 newMask = newNumBuckets - 1; 895 896 /* Allocate and initialize new table */ 897 MALLOC(newTab, struct ng_bridge_bucket *, 898 newNumBuckets * sizeof(*newTab), M_NETGRAPH, M_NOWAIT | M_ZERO); 899 if (newTab == NULL) 900 return; 901 902 /* Move all entries from old table to new table */ 903 for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) { 904 struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket]; 905 906 while (!SLIST_EMPTY(oldList)) { 907 struct ng_bridge_hent *const hent 908 = SLIST_FIRST(oldList); 909 910 SLIST_REMOVE_HEAD(oldList, next); 911 newBucket = HASH(hent->host.addr, newMask); 912 SLIST_INSERT_HEAD(&newTab[newBucket], hent, next); 913 } 914 } 915 916 /* Replace old table with new one */ 917 if (priv->conf.debugLevel >= 3) { 918 log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n", 919 ng_bridge_nodename(priv->node), 920 priv->numBuckets, newNumBuckets); 921 } 922 FREE(priv->tab, M_NETGRAPH); 923 priv->numBuckets = newNumBuckets; 924 priv->hashMask = newMask; 925 priv->tab = newTab; 926 return; 927} 928 929/****************************************************************** 930 MISC FUNCTIONS 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 */ 937static void 938ng_bridge_remove_hosts(priv_p priv, int linkNum) 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 (linkNum == -1 || hent->host.linkNum == linkNum) { 949 *hptr = SLIST_NEXT(hent, next); 950 FREE(hent, M_NETGRAPH); 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 */ 964static void 965ng_bridge_timeout(void *arg) 966{ 967 const node_p node = arg; 968 const priv_p priv = node->private; 969 int s, bucket; 970 int counter = 0; 971 int linkNum; 972 973 /* Avoid race condition with ng_bridge_shutdown() */ 974 s = splnet(); 975 if ((node->flags & NG_INVALID) != 0 || priv == NULL) { 976 ng_unref(node); 977 splx(s); 978 return; 979 } 980 981 /* Register a new timeout, keeping the existing node reference */ 982 callout_reset(&priv->timer, hz, ng_bridge_timeout, node); 983 984 /* Update host time counters and remove stale entries */ 985 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 986 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 987 988 while (*hptr != NULL) { 989 struct ng_bridge_hent *const hent = *hptr; 990 991 /* Make sure host's link really exists */ 992 KASSERT(priv->links[hent->host.linkNum] != NULL, 993 ("%s: host %6D on nonexistent link %d\n", 994 __FUNCTION__, hent->host.addr, ":", 995 hent->host.linkNum)); 996 997 /* Remove hosts we haven't heard from in a while */ 998 if (++hent->host.staleness >= priv->conf.maxStaleness) { 999 *hptr = SLIST_NEXT(hent, next); 1000 FREE(hent, M_NETGRAPH); 1001 priv->numHosts--; 1002 } else { 1003 if (hent->host.age < 0xffff) 1004 hent->host.age++; 1005 hptr = &SLIST_NEXT(hent, next); 1006 counter++; 1007 } 1008 } 1009 } 1010 KASSERT(priv->numHosts == counter, 1011 ("%s: hosts: %d != %d", __FUNCTION__, priv->numHosts, counter)); 1012 1013 /* Decrease table size if necessary */ 1014 ng_bridge_rehash(priv); 1015 1016 /* Decrease loop counter on muted looped back links */ 1017 for (counter = linkNum = 0; linkNum < NG_BRIDGE_MAX_LINKS; linkNum++) { 1018 struct ng_bridge_link *const link = priv->links[linkNum]; 1019 1020 if (link != NULL) { 1021 if (link->loopCount != 0) { 1022 link->loopCount--; 1023 if (link->loopCount == 0 1024 && priv->conf.debugLevel >= 2) { 1025 log(LOG_INFO, "ng_bridge: %s:" 1026 " restoring looped back link%d\n", 1027 ng_bridge_nodename(node), linkNum); 1028 } 1029 } 1030 counter++; 1031 } 1032 } 1033 KASSERT(priv->numLinks == counter, 1034 ("%s: links: %d != %d", __FUNCTION__, priv->numLinks, counter)); 1035 1036 /* Done */ 1037 splx(s); 1038} 1039 1040/* 1041 * Return node's "name", even if it doesn't have one. 1042 */ 1043static const char * 1044ng_bridge_nodename(node_p node) 1045{ 1046 static char name[NG_NODELEN+1]; 1047 1048 if (node->name != NULL) 1049 snprintf(name, sizeof(name), "%s", node->name); 1050 else 1051 snprintf(name, sizeof(name), "[%x]", ng_node2ID(node)); 1052 return name; 1053} 1054 1055