ng_bridge.c revision 87599
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 87599 2001-12-10 08:09:49Z obrien $ 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#ifdef NG_SEPARATE_MALLOC 83MALLOC_DEFINE(M_NETGRAPH_BRIDGE, "netgraph_bridge", "netgraph bridge node "); 84#else 85#define M_NETGRAPH_BRIDGE M_NETGRAPH 86#endif 87 88/* Per-link private data */ 89struct ng_bridge_link { 90 hook_p hook; /* netgraph hook */ 91 u_int16_t loopCount; /* loop ignore timer */ 92 struct ng_bridge_link_stats stats; /* link stats */ 93}; 94 95/* Per-node private data */ 96struct ng_bridge_private { 97 struct ng_bridge_bucket *tab; /* hash table bucket array */ 98 struct ng_bridge_link *links[NG_BRIDGE_MAX_LINKS]; 99 struct ng_bridge_config conf; /* node configuration */ 100 node_p node; /* netgraph node */ 101 u_int numHosts; /* num entries in table */ 102 u_int numBuckets; /* num buckets in table */ 103 u_int hashMask; /* numBuckets - 1 */ 104 int numLinks; /* num connected links */ 105 struct callout timer; /* one second periodic timer */ 106}; 107typedef struct ng_bridge_private *priv_p; 108 109/* Information about a host, stored in a hash table entry */ 110struct ng_bridge_hent { 111 struct ng_bridge_host host; /* actual host info */ 112 SLIST_ENTRY(ng_bridge_hent) next; /* next entry in bucket */ 113}; 114 115/* Hash table bucket declaration */ 116SLIST_HEAD(ng_bridge_bucket, ng_bridge_hent); 117 118/* Netgraph node methods */ 119static ng_constructor_t ng_bridge_constructor; 120static ng_rcvmsg_t ng_bridge_rcvmsg; 121static ng_shutdown_t ng_bridge_shutdown; 122static ng_newhook_t ng_bridge_newhook; 123static ng_rcvdata_t ng_bridge_rcvdata; 124static ng_disconnect_t ng_bridge_disconnect; 125 126/* Other internal functions */ 127static struct ng_bridge_host *ng_bridge_get(priv_p priv, const u_char *addr); 128static int ng_bridge_put(priv_p priv, const u_char *addr, int linkNum); 129static void ng_bridge_rehash(priv_p priv); 130static void ng_bridge_remove_hosts(priv_p priv, int linkNum); 131static void ng_bridge_timeout(void *arg); 132static const char *ng_bridge_nodename(node_p node); 133 134/* Ethernet broadcast */ 135static const u_char ng_bridge_bcast_addr[ETHER_ADDR_LEN] = 136 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; 137 138/* Store each hook's link number in the private field */ 139#define LINK_NUM(hook) (*(u_int16_t *)(&(hook)->private)) 140 141/* Compare Ethernet addresses using 32 and 16 bit words instead of bytewise */ 142#define ETHER_EQUAL(a,b) (((const u_int32_t *)(a))[0] \ 143 == ((const u_int32_t *)(b))[0] \ 144 && ((const u_int16_t *)(a))[2] \ 145 == ((const u_int16_t *)(b))[2]) 146 147/* Minimum and maximum number of hash buckets. Must be a power of two. */ 148#define MIN_BUCKETS (1 << 5) /* 32 */ 149#define MAX_BUCKETS (1 << 14) /* 16384 */ 150 151/* Configuration default values */ 152#define DEFAULT_LOOP_TIMEOUT 60 153#define DEFAULT_MAX_STALENESS (15 * 60) /* same as ARP timeout */ 154#define DEFAULT_MIN_STABLE_AGE 1 155 156/****************************************************************** 157 NETGRAPH PARSE TYPES 158******************************************************************/ 159 160/* 161 * How to determine the length of the table returned by NGM_BRIDGE_GET_TABLE 162 */ 163static int 164ng_bridge_getTableLength(const struct ng_parse_type *type, 165 const u_char *start, const u_char *buf) 166{ 167 const struct ng_bridge_host_ary *const hary 168 = (const struct ng_bridge_host_ary *)(buf - sizeof(u_int32_t)); 169 170 return hary->numHosts; 171} 172 173/* Parse type for struct ng_bridge_host_ary */ 174static const struct ng_parse_struct_info ng_bridge_host_type_info 175 = NG_BRIDGE_HOST_TYPE_INFO(&ng_ether_enaddr_type); 176static const struct ng_parse_type ng_bridge_host_type = { 177 &ng_parse_struct_type, 178 &ng_bridge_host_type_info 179}; 180static const struct ng_parse_array_info ng_bridge_hary_type_info = { 181 &ng_bridge_host_type, 182 ng_bridge_getTableLength 183}; 184static const struct ng_parse_type ng_bridge_hary_type = { 185 &ng_parse_array_type, 186 &ng_bridge_hary_type_info 187}; 188static const struct ng_parse_struct_info ng_bridge_host_ary_type_info 189 = NG_BRIDGE_HOST_ARY_TYPE_INFO(&ng_bridge_hary_type); 190static const struct ng_parse_type ng_bridge_host_ary_type = { 191 &ng_parse_struct_type, 192 &ng_bridge_host_ary_type_info 193}; 194 195/* Parse type for struct ng_bridge_config */ 196static const struct ng_parse_fixedarray_info ng_bridge_ipfwary_type_info = { 197 &ng_parse_uint8_type, 198 NG_BRIDGE_MAX_LINKS 199}; 200static const struct ng_parse_type ng_bridge_ipfwary_type = { 201 &ng_parse_fixedarray_type, 202 &ng_bridge_ipfwary_type_info 203}; 204static const struct ng_parse_struct_info ng_bridge_config_type_info 205 = NG_BRIDGE_CONFIG_TYPE_INFO(&ng_bridge_ipfwary_type); 206static const struct ng_parse_type ng_bridge_config_type = { 207 &ng_parse_struct_type, 208 &ng_bridge_config_type_info 209}; 210 211/* Parse type for struct ng_bridge_link_stat */ 212static const struct ng_parse_struct_info 213 ng_bridge_stats_type_info = NG_BRIDGE_STATS_TYPE_INFO; 214static const struct ng_parse_type ng_bridge_stats_type = { 215 &ng_parse_struct_type, 216 &ng_bridge_stats_type_info 217}; 218 219/* List of commands and how to convert arguments to/from ASCII */ 220static const struct ng_cmdlist ng_bridge_cmdlist[] = { 221 { 222 NGM_BRIDGE_COOKIE, 223 NGM_BRIDGE_SET_CONFIG, 224 "setconfig", 225 &ng_bridge_config_type, 226 NULL 227 }, 228 { 229 NGM_BRIDGE_COOKIE, 230 NGM_BRIDGE_GET_CONFIG, 231 "getconfig", 232 NULL, 233 &ng_bridge_config_type 234 }, 235 { 236 NGM_BRIDGE_COOKIE, 237 NGM_BRIDGE_RESET, 238 "reset", 239 NULL, 240 NULL 241 }, 242 { 243 NGM_BRIDGE_COOKIE, 244 NGM_BRIDGE_GET_STATS, 245 "getstats", 246 &ng_parse_uint32_type, 247 &ng_bridge_stats_type 248 }, 249 { 250 NGM_BRIDGE_COOKIE, 251 NGM_BRIDGE_CLR_STATS, 252 "clrstats", 253 &ng_parse_uint32_type, 254 NULL 255 }, 256 { 257 NGM_BRIDGE_COOKIE, 258 NGM_BRIDGE_GETCLR_STATS, 259 "getclrstats", 260 &ng_parse_uint32_type, 261 &ng_bridge_stats_type 262 }, 263 { 264 NGM_BRIDGE_COOKIE, 265 NGM_BRIDGE_GET_TABLE, 266 "gettable", 267 NULL, 268 &ng_bridge_host_ary_type 269 }, 270 { 0 } 271}; 272 273/* Node type descriptor */ 274static struct ng_type ng_bridge_typestruct = { 275 NG_ABI_VERSION, 276 NG_BRIDGE_NODE_TYPE, 277 NULL, 278 ng_bridge_constructor, 279 ng_bridge_rcvmsg, 280 ng_bridge_shutdown, 281 ng_bridge_newhook, 282 NULL, 283 NULL, 284 ng_bridge_rcvdata, 285 ng_bridge_disconnect, 286 ng_bridge_cmdlist, 287}; 288NETGRAPH_INIT(bridge, &ng_bridge_typestruct); 289 290/* Depend on ng_ether so we can use the Ethernet parse type */ 291MODULE_DEPEND(ng_bridge, ng_ether, 1, 1, 1); 292 293/****************************************************************** 294 NETGRAPH NODE METHODS 295******************************************************************/ 296 297/* 298 * Node constructor 299 */ 300static int 301ng_bridge_constructor(node_p node) 302{ 303 priv_p priv; 304 305 /* Allocate and initialize private info */ 306 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO); 307 if (priv == NULL) 308 return (ENOMEM); 309 callout_init(&priv->timer, 0); 310 311 /* Allocate and initialize hash table, etc. */ 312 MALLOC(priv->tab, struct ng_bridge_bucket *, 313 MIN_BUCKETS * sizeof(*priv->tab), M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO); 314 if (priv->tab == NULL) { 315 FREE(priv, M_NETGRAPH_BRIDGE); 316 return (ENOMEM); 317 } 318 priv->numBuckets = MIN_BUCKETS; 319 priv->hashMask = MIN_BUCKETS - 1; 320 priv->conf.debugLevel = 1; 321 priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT; 322 priv->conf.maxStaleness = DEFAULT_MAX_STALENESS; 323 priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE; 324 325 /* 326 * This node has all kinds of stuff that could be screwed by SMP. 327 * Until it gets it's own internal protection, we go through in 328 * single file. This could hurt a machine bridging beteen two 329 * GB ethernets so it should be fixed. 330 * When it's fixed the process SHOULD NOT SLEEP, spinlocks please! 331 * (and atomic ops ) 332 */ 333 NG_NODE_FORCE_WRITER(node); 334 NG_NODE_SET_PRIVATE(node, priv); 335 priv->node = node; 336 337 /* Start timer by faking a timeout event */ 338 NG_NODE_REF(node); /* because the timeout will drop a reference */ 339 ng_bridge_timeout(node); 340 return (0); 341} 342 343/* 344 * Method for attaching a new hook 345 */ 346static int 347ng_bridge_newhook(node_p node, hook_p hook, const char *name) 348{ 349 const priv_p priv = NG_NODE_PRIVATE(node); 350 351 /* Check for a link hook */ 352 if (strncmp(name, NG_BRIDGE_HOOK_LINK_PREFIX, 353 strlen(NG_BRIDGE_HOOK_LINK_PREFIX)) == 0) { 354 const char *cp; 355 char *eptr; 356 u_long linkNum; 357 358 cp = name + strlen(NG_BRIDGE_HOOK_LINK_PREFIX); 359 if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0')) 360 return (EINVAL); 361 linkNum = strtoul(cp, &eptr, 10); 362 if (*eptr != '\0' || linkNum >= NG_BRIDGE_MAX_LINKS) 363 return (EINVAL); 364 if (priv->links[linkNum] != NULL) 365 return (EISCONN); 366 MALLOC(priv->links[linkNum], struct ng_bridge_link *, 367 sizeof(*priv->links[linkNum]), M_NETGRAPH_BRIDGE, M_NOWAIT|M_ZERO); 368 if (priv->links[linkNum] == NULL) 369 return (ENOMEM); 370 priv->links[linkNum]->hook = hook; 371 NG_HOOK_SET_PRIVATE(hook, (void *)linkNum); 372 priv->numLinks++; 373 return (0); 374 } 375 376 /* Unknown hook name */ 377 return (EINVAL); 378} 379 380/* 381 * Receive a control message 382 */ 383static int 384ng_bridge_rcvmsg(node_p node, item_p item, hook_p lasthook) 385{ 386 const priv_p priv = NG_NODE_PRIVATE(node); 387 struct ng_mesg *resp = NULL; 388 int error = 0; 389 struct ng_mesg *msg; 390 391 NGI_GET_MSG(item, msg); 392 switch (msg->header.typecookie) { 393 case NGM_BRIDGE_COOKIE: 394 switch (msg->header.cmd) { 395 case NGM_BRIDGE_GET_CONFIG: 396 { 397 struct ng_bridge_config *conf; 398 399 NG_MKRESPONSE(resp, msg, 400 sizeof(struct ng_bridge_config), M_NOWAIT); 401 if (resp == NULL) { 402 error = ENOMEM; 403 break; 404 } 405 conf = (struct ng_bridge_config *)resp->data; 406 *conf = priv->conf; /* no sanity checking needed */ 407 break; 408 } 409 case NGM_BRIDGE_SET_CONFIG: 410 { 411 struct ng_bridge_config *conf; 412 int i; 413 414 if (msg->header.arglen 415 != sizeof(struct ng_bridge_config)) { 416 error = EINVAL; 417 break; 418 } 419 conf = (struct ng_bridge_config *)msg->data; 420 priv->conf = *conf; 421 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) 422 priv->conf.ipfw[i] = !!priv->conf.ipfw[i]; 423 break; 424 } 425 case NGM_BRIDGE_RESET: 426 { 427 int i; 428 429 /* Flush all entries in the hash table */ 430 ng_bridge_remove_hosts(priv, -1); 431 432 /* Reset all loop detection counters and stats */ 433 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) { 434 if (priv->links[i] == NULL) 435 continue; 436 priv->links[i]->loopCount = 0; 437 bzero(&priv->links[i]->stats, 438 sizeof(priv->links[i]->stats)); 439 } 440 break; 441 } 442 case NGM_BRIDGE_GET_STATS: 443 case NGM_BRIDGE_CLR_STATS: 444 case NGM_BRIDGE_GETCLR_STATS: 445 { 446 struct ng_bridge_link *link; 447 int linkNum; 448 449 /* Get link number */ 450 if (msg->header.arglen != sizeof(u_int32_t)) { 451 error = EINVAL; 452 break; 453 } 454 linkNum = *((u_int32_t *)msg->data); 455 if (linkNum < 0 || linkNum >= NG_BRIDGE_MAX_LINKS) { 456 error = EINVAL; 457 break; 458 } 459 if ((link = priv->links[linkNum]) == NULL) { 460 error = ENOTCONN; 461 break; 462 } 463 464 /* Get/clear stats */ 465 if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) { 466 NG_MKRESPONSE(resp, msg, 467 sizeof(link->stats), M_NOWAIT); 468 if (resp == NULL) { 469 error = ENOMEM; 470 break; 471 } 472 bcopy(&link->stats, 473 resp->data, sizeof(link->stats)); 474 } 475 if (msg->header.cmd != NGM_BRIDGE_GET_STATS) 476 bzero(&link->stats, sizeof(link->stats)); 477 break; 478 } 479 case NGM_BRIDGE_GET_TABLE: 480 { 481 struct ng_bridge_host_ary *ary; 482 struct ng_bridge_hent *hent; 483 int i = 0, bucket; 484 485 NG_MKRESPONSE(resp, msg, sizeof(*ary) 486 + (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT); 487 if (resp == NULL) { 488 error = ENOMEM; 489 break; 490 } 491 ary = (struct ng_bridge_host_ary *)resp->data; 492 ary->numHosts = priv->numHosts; 493 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 494 SLIST_FOREACH(hent, &priv->tab[bucket], next) 495 ary->hosts[i++] = hent->host; 496 } 497 break; 498 } 499 default: 500 error = EINVAL; 501 break; 502 } 503 break; 504 default: 505 error = EINVAL; 506 break; 507 } 508 509 /* Done */ 510 NG_RESPOND_MSG(error, node, item, resp); 511 NG_FREE_MSG(msg); 512 return (error); 513} 514 515/* 516 * Receive data on a hook 517 */ 518static int 519ng_bridge_rcvdata(hook_p hook, item_p item) 520{ 521 const node_p node = NG_HOOK_NODE(hook); 522 const priv_p priv = NG_NODE_PRIVATE(node); 523 struct ng_bridge_host *host; 524 struct ng_bridge_link *link; 525 struct ether_header *eh; 526 int error = 0, linkNum; 527 int manycast; 528 struct mbuf *m; 529 meta_p meta; 530 struct ng_bridge_link *firstLink; 531 532 NGI_GET_M(item, m); 533 /* Get link number */ 534 linkNum = (int)NG_HOOK_PRIVATE(hook); 535 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 536 ("%s: linkNum=%u", __func__, linkNum)); 537 link = priv->links[linkNum]; 538 KASSERT(link != NULL, ("%s: link%d null", __func__, linkNum)); 539 540 /* Sanity check packet and pull up header */ 541 if (m->m_pkthdr.len < ETHER_HDR_LEN) { 542 link->stats.recvRunts++; 543 NG_FREE_ITEM(item); 544 NG_FREE_M(m); 545 return (EINVAL); 546 } 547 if (m->m_len < ETHER_HDR_LEN && !(m = m_pullup(m, ETHER_HDR_LEN))) { 548 link->stats.memoryFailures++; 549 NG_FREE_ITEM(item); 550 return (ENOBUFS); 551 } 552 eh = mtod(m, struct ether_header *); 553 if ((eh->ether_shost[0] & 1) != 0) { 554 link->stats.recvInvalid++; 555 NG_FREE_ITEM(item); 556 NG_FREE_M(m); 557 return (EINVAL); 558 } 559 560 /* Is link disabled due to a loopback condition? */ 561 if (link->loopCount != 0) { 562 link->stats.loopDrops++; 563 NG_FREE_ITEM(item); 564 NG_FREE_M(m); 565 return (ELOOP); /* XXX is this an appropriate error? */ 566 } 567 568 /* Update stats */ 569 link->stats.recvPackets++; 570 link->stats.recvOctets += m->m_pkthdr.len; 571 if ((manycast = (eh->ether_dhost[0] & 1)) != 0) { 572 if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) { 573 link->stats.recvBroadcasts++; 574 manycast = 2; 575 } else 576 link->stats.recvMulticasts++; 577 } 578 579 /* Look up packet's source Ethernet address in hashtable */ 580 if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) { 581 582 /* Update time since last heard from this host */ 583 host->staleness = 0; 584 585 /* Did host jump to a different link? */ 586 if (host->linkNum != linkNum) { 587 588 /* 589 * If the host's old link was recently established 590 * on the old link and it's already jumped to a new 591 * link, declare a loopback condition. 592 */ 593 if (host->age < priv->conf.minStableAge) { 594 595 /* Log the problem */ 596 if (priv->conf.debugLevel >= 2) { 597 struct ifnet *ifp = m->m_pkthdr.rcvif; 598 char suffix[32]; 599 600 if (ifp != NULL) 601 snprintf(suffix, sizeof(suffix), 602 " (%s%d)", ifp->if_name, 603 ifp->if_unit); 604 else 605 *suffix = '\0'; 606 log(LOG_WARNING, "ng_bridge: %s:" 607 " loopback detected on %s%s\n", 608 ng_bridge_nodename(node), 609 NG_HOOK_NAME(hook), suffix); 610 } 611 612 /* Mark link as linka non grata */ 613 link->loopCount = priv->conf.loopTimeout; 614 link->stats.loopDetects++; 615 616 /* Forget all hosts on this link */ 617 ng_bridge_remove_hosts(priv, linkNum); 618 619 /* Drop packet */ 620 link->stats.loopDrops++; 621 NG_FREE_ITEM(item); 622 NG_FREE_M(m); 623 return (ELOOP); /* XXX appropriate? */ 624 } 625 626 /* Move host over to new link */ 627 host->linkNum = linkNum; 628 host->age = 0; 629 } 630 } else { 631 if (!ng_bridge_put(priv, eh->ether_shost, linkNum)) { 632 link->stats.memoryFailures++; 633 NG_FREE_ITEM(item); 634 NG_FREE_M(m); 635 return (ENOMEM); 636 } 637 } 638 639 /* Run packet through ipfw processing, if enabled */ 640 if (priv->conf.ipfw[linkNum] && fw_enable && ip_fw_chk_ptr != NULL) { 641 /* XXX not implemented yet */ 642 } 643 644 /* 645 * If unicast and destination host known, deliver to host's link, 646 * unless it is the same link as the packet came in on. 647 */ 648 if (!manycast) { 649 650 /* Determine packet destination link */ 651 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) { 652 struct ng_bridge_link *const destLink 653 = priv->links[host->linkNum]; 654 655 /* If destination same as incoming link, do nothing */ 656 KASSERT(destLink != NULL, 657 ("%s: link%d null", __func__, host->linkNum)); 658 if (destLink == link) { 659 NG_FREE_ITEM(item); 660 NG_FREE_M(m); 661 return (0); 662 } 663 664 /* Deliver packet out the destination link */ 665 destLink->stats.xmitPackets++; 666 destLink->stats.xmitOctets += m->m_pkthdr.len; 667 NG_FWD_NEW_DATA(error, item, destLink->hook, m); 668 return (error); 669 } 670 671 /* Destination host is not known */ 672 link->stats.recvUnknown++; 673 } 674 675 /* Distribute unknown, multicast, broadcast pkts to all other links */ 676 meta = NGI_META(item); /* peek.. */ 677 firstLink = NULL; 678 for (linkNum = 0; linkNum <= priv->numLinks; linkNum++) { 679 struct ng_bridge_link *destLink; 680 meta_p meta2 = NULL; 681 struct mbuf *m2 = NULL; 682 683 /* 684 * If we have checked all the links then now 685 * send the original on its reserved link 686 */ 687 if (linkNum == priv->numLinks) { 688 /* If we never saw a good link, leave. */ 689 if (firstLink == NULL) { 690 NG_FREE_ITEM(item); 691 NG_FREE_M(m); 692 return (0); 693 } 694 destLink = firstLink; 695 } else { 696 destLink = priv->links[linkNum]; 697 /* Skip incoming link and disconnected links */ 698 if (destLink == NULL || destLink == link) { 699 continue; 700 } 701 if (firstLink == NULL) { 702 /* 703 * This is the first usable link we have found. 704 * Reserve it for the originals. 705 * If we never find another we save a copy. 706 */ 707 firstLink = destLink; 708 continue; 709 } 710 711 /* 712 * It's usable link but not the reserved (first) one. 713 * Copy mbuf and meta info for sending. 714 */ 715 m2 = m_dup(m, M_NOWAIT); /* XXX m_copypacket() */ 716 if (m2 == NULL) { 717 link->stats.memoryFailures++; 718 NG_FREE_ITEM(item); 719 NG_FREE_M(m); 720 return (ENOBUFS); 721 } 722 if (meta != NULL 723 && (meta2 = ng_copy_meta(meta)) == NULL) { 724 link->stats.memoryFailures++; 725 m_freem(m2); 726 NG_FREE_ITEM(item); 727 NG_FREE_M(m); 728 return (ENOMEM); 729 } 730 } 731 732 /* Update stats */ 733 destLink->stats.xmitPackets++; 734 destLink->stats.xmitOctets += m->m_pkthdr.len; 735 switch (manycast) { 736 case 0: /* unicast */ 737 break; 738 case 1: /* multicast */ 739 destLink->stats.xmitMulticasts++; 740 break; 741 case 2: /* broadcast */ 742 destLink->stats.xmitBroadcasts++; 743 break; 744 } 745 746 /* Send packet */ 747 if (destLink == firstLink) { 748 /* 749 * If we've sent all the others, send the original 750 * on the first link we found. 751 */ 752 NG_FWD_NEW_DATA(error, item, destLink->hook, m); 753 break; /* always done last - not really needed. */ 754 } else { 755 NG_SEND_DATA(error, destLink->hook, m2, meta2); 756 } 757 } 758 return (error); 759} 760 761/* 762 * Shutdown node 763 */ 764static int 765ng_bridge_shutdown(node_p node) 766{ 767 const priv_p priv = NG_NODE_PRIVATE(node); 768 769 KASSERT(priv->numLinks == 0 && priv->numHosts == 0, 770 ("%s: numLinks=%d numHosts=%d", 771 __func__, priv->numLinks, priv->numHosts)); 772 FREE(priv->tab, M_NETGRAPH_BRIDGE); 773 FREE(priv, M_NETGRAPH_BRIDGE); 774 NG_NODE_SET_PRIVATE(node, NULL); 775 NG_NODE_UNREF(node); 776 return (0); 777} 778 779/* 780 * Hook disconnection. 781 */ 782static int 783ng_bridge_disconnect(hook_p hook) 784{ 785 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); 786 int linkNum; 787 788 /* Get link number */ 789 linkNum = (int)NG_HOOK_PRIVATE(hook); 790 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 791 ("%s: linkNum=%u", __func__, linkNum)); 792 793 /* Remove all hosts associated with this link */ 794 ng_bridge_remove_hosts(priv, linkNum); 795 796 /* Free associated link information */ 797 KASSERT(priv->links[linkNum] != NULL, ("%s: no link", __func__)); 798 FREE(priv->links[linkNum], M_NETGRAPH_BRIDGE); 799 priv->links[linkNum] = NULL; 800 priv->numLinks--; 801 802 /* If no more hooks, go away */ 803 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) 804 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) { 805 ng_rmnode_self(NG_HOOK_NODE(hook)); 806 } 807 return (0); 808} 809 810/****************************************************************** 811 HASH TABLE FUNCTIONS 812******************************************************************/ 813 814/* 815 * Hash algorithm 816 * 817 * Only hashing bytes 3-6 of the Ethernet address is sufficient and fast. 818 */ 819#define HASH(addr,mask) ( (((const u_int16_t *)(addr))[0] \ 820 ^ ((const u_int16_t *)(addr))[1] \ 821 ^ ((const u_int16_t *)(addr))[2]) & (mask) ) 822 823/* 824 * Find a host entry in the table. 825 */ 826static struct ng_bridge_host * 827ng_bridge_get(priv_p priv, const u_char *addr) 828{ 829 const int bucket = HASH(addr, priv->hashMask); 830 struct ng_bridge_hent *hent; 831 832 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 833 if (ETHER_EQUAL(hent->host.addr, addr)) 834 return (&hent->host); 835 } 836 return (NULL); 837} 838 839/* 840 * Add a new host entry to the table. This assumes the host doesn't 841 * already exist in the table. Returns 1 on success, 0 if there 842 * was a memory allocation failure. 843 */ 844static int 845ng_bridge_put(priv_p priv, const u_char *addr, int linkNum) 846{ 847 const int bucket = HASH(addr, priv->hashMask); 848 struct ng_bridge_hent *hent; 849 850#ifdef INVARIANTS 851 /* Assert that entry does not already exist in hashtable */ 852 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 853 KASSERT(!ETHER_EQUAL(hent->host.addr, addr), 854 ("%s: entry %6D exists in table", __func__, addr, ":")); 855 } 856#endif 857 858 /* Allocate and initialize new hashtable entry */ 859 MALLOC(hent, struct ng_bridge_hent *, 860 sizeof(*hent), M_NETGRAPH_BRIDGE, M_NOWAIT); 861 if (hent == NULL) 862 return (0); 863 bcopy(addr, hent->host.addr, ETHER_ADDR_LEN); 864 hent->host.linkNum = linkNum; 865 hent->host.staleness = 0; 866 hent->host.age = 0; 867 868 /* Add new element to hash bucket */ 869 SLIST_INSERT_HEAD(&priv->tab[bucket], hent, next); 870 priv->numHosts++; 871 872 /* Resize table if necessary */ 873 ng_bridge_rehash(priv); 874 return (1); 875} 876 877/* 878 * Resize the hash table. We try to maintain the number of buckets 879 * such that the load factor is in the range 0.25 to 1.0. 880 * 881 * If we can't get the new memory then we silently fail. This is OK 882 * because things will still work and we'll try again soon anyway. 883 */ 884static void 885ng_bridge_rehash(priv_p priv) 886{ 887 struct ng_bridge_bucket *newTab; 888 int oldBucket, newBucket; 889 int newNumBuckets; 890 u_int newMask; 891 892 /* Is table too full or too empty? */ 893 if (priv->numHosts > priv->numBuckets 894 && (priv->numBuckets << 1) <= MAX_BUCKETS) 895 newNumBuckets = priv->numBuckets << 1; 896 else if (priv->numHosts < (priv->numBuckets >> 2) 897 && (priv->numBuckets >> 2) >= MIN_BUCKETS) 898 newNumBuckets = priv->numBuckets >> 2; 899 else 900 return; 901 newMask = newNumBuckets - 1; 902 903 /* Allocate and initialize new table */ 904 MALLOC(newTab, struct ng_bridge_bucket *, 905 newNumBuckets * sizeof(*newTab), M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO); 906 if (newTab == NULL) 907 return; 908 909 /* Move all entries from old table to new table */ 910 for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) { 911 struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket]; 912 913 while (!SLIST_EMPTY(oldList)) { 914 struct ng_bridge_hent *const hent 915 = SLIST_FIRST(oldList); 916 917 SLIST_REMOVE_HEAD(oldList, next); 918 newBucket = HASH(hent->host.addr, newMask); 919 SLIST_INSERT_HEAD(&newTab[newBucket], hent, next); 920 } 921 } 922 923 /* Replace old table with new one */ 924 if (priv->conf.debugLevel >= 3) { 925 log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n", 926 ng_bridge_nodename(priv->node), 927 priv->numBuckets, newNumBuckets); 928 } 929 FREE(priv->tab, M_NETGRAPH_BRIDGE); 930 priv->numBuckets = newNumBuckets; 931 priv->hashMask = newMask; 932 priv->tab = newTab; 933 return; 934} 935 936/****************************************************************** 937 MISC FUNCTIONS 938******************************************************************/ 939 940/* 941 * Remove all hosts associated with a specific link from the hashtable. 942 * If linkNum == -1, then remove all hosts in the table. 943 */ 944static void 945ng_bridge_remove_hosts(priv_p priv, int linkNum) 946{ 947 int bucket; 948 949 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 950 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 951 952 while (*hptr != NULL) { 953 struct ng_bridge_hent *const hent = *hptr; 954 955 if (linkNum == -1 || hent->host.linkNum == linkNum) { 956 *hptr = SLIST_NEXT(hent, next); 957 FREE(hent, M_NETGRAPH_BRIDGE); 958 priv->numHosts--; 959 } else 960 hptr = &SLIST_NEXT(hent, next); 961 } 962 } 963} 964 965/* 966 * Handle our once-per-second timeout event. We do two things: 967 * we decrement link->loopCount for those links being muted due to 968 * a detected loopback condition, and we remove any hosts from 969 * the hashtable whom we haven't heard from in a long while. 970 */ 971static void 972ng_bridge_timeout(void *arg) 973{ 974 const node_p node = arg; 975 const priv_p priv = NG_NODE_PRIVATE(node); 976 int s, bucket; 977 int counter = 0; 978 int linkNum; 979 980 /* Avoid race condition with ng_bridge_shutdown() */ 981 s = splnet(); 982 if ((NG_NODE_NOT_VALID(node)) || priv == NULL) { 983 NG_NODE_UNREF(node); 984 splx(s); 985 return; 986 } 987 988 /* Register a new timeout, keeping the existing node reference */ 989 callout_reset(&priv->timer, hz, ng_bridge_timeout, node); 990 991 /* Update host time counters and remove stale entries */ 992 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 993 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 994 995 while (*hptr != NULL) { 996 struct ng_bridge_hent *const hent = *hptr; 997 998 /* Make sure host's link really exists */ 999 KASSERT(priv->links[hent->host.linkNum] != NULL, 1000 ("%s: host %6D on nonexistent link %d\n", 1001 __func__, hent->host.addr, ":", 1002 hent->host.linkNum)); 1003 1004 /* Remove hosts we haven't heard from in a while */ 1005 if (++hent->host.staleness >= priv->conf.maxStaleness) { 1006 *hptr = SLIST_NEXT(hent, next); 1007 FREE(hent, M_NETGRAPH_BRIDGE); 1008 priv->numHosts--; 1009 } else { 1010 if (hent->host.age < 0xffff) 1011 hent->host.age++; 1012 hptr = &SLIST_NEXT(hent, next); 1013 counter++; 1014 } 1015 } 1016 } 1017 KASSERT(priv->numHosts == counter, 1018 ("%s: hosts: %d != %d", __func__, priv->numHosts, counter)); 1019 1020 /* Decrease table size if necessary */ 1021 ng_bridge_rehash(priv); 1022 1023 /* Decrease loop counter on muted looped back links */ 1024 for (counter = linkNum = 0; linkNum < NG_BRIDGE_MAX_LINKS; linkNum++) { 1025 struct ng_bridge_link *const link = priv->links[linkNum]; 1026 1027 if (link != NULL) { 1028 if (link->loopCount != 0) { 1029 link->loopCount--; 1030 if (link->loopCount == 0 1031 && priv->conf.debugLevel >= 2) { 1032 log(LOG_INFO, "ng_bridge: %s:" 1033 " restoring looped back link%d\n", 1034 ng_bridge_nodename(node), linkNum); 1035 } 1036 } 1037 counter++; 1038 } 1039 } 1040 KASSERT(priv->numLinks == counter, 1041 ("%s: links: %d != %d", __func__, priv->numLinks, counter)); 1042 1043 /* Done */ 1044 splx(s); 1045} 1046 1047/* 1048 * Return node's "name", even if it doesn't have one. 1049 */ 1050static const char * 1051ng_bridge_nodename(node_p node) 1052{ 1053 static char name[NG_NODELEN+1]; 1054 1055 if (NG_NODE_NAME(node) != NULL) 1056 snprintf(name, sizeof(name), "%s", NG_NODE_NAME(node)); 1057 else 1058 snprintf(name, sizeof(name), "[%x]", ng_node2ID(node)); 1059 return name; 1060} 1061 1062