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 *
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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_rmnode; 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 = {
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270 NG_BRIDGE_NODE_TYPE, 271 NULL, 272 ng_bridge_constructor, 273 ng_bridge_rcvmsg, 274 ng_bridge_rmnode, 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 *nodep) 296{ 297 priv_p priv; 298 int error; 299 300 /* Allocate and initialize private info */ 301 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO); 302 if (priv == NULL) 303 return (ENOMEM); 304 callout_init(&priv->timer, 0); 305 306 /* Allocate and initialize hash table, etc. */ 307 MALLOC(priv->tab, struct ng_bridge_bucket *, 308 MIN_BUCKETS * sizeof(*priv->tab), M_NETGRAPH, M_NOWAIT | M_ZERO); 309 if (priv->tab == NULL) { 310 FREE(priv, M_NETGRAPH); 311 return (ENOMEM); 312 } 313 priv->numBuckets = MIN_BUCKETS; 314 priv->hashMask = MIN_BUCKETS - 1; 315 priv->conf.debugLevel = 1; 316 priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT; 317 priv->conf.maxStaleness = DEFAULT_MAX_STALENESS; 318 priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE; 319 320 /* Call superclass constructor */ 321 if ((error = ng_make_node_common(&ng_bridge_typestruct, nodep))) { 322 FREE(priv, M_NETGRAPH); 323 return (error); 324 } 325 (*nodep)->private = priv; 326 priv->node = *nodep; 327 328 /* Start timer by faking a timeout event */ 329 (*nodep)->refs++; 330 ng_bridge_timeout(*nodep); 331 return (0); 332} 333 334/* 335 * Method for attaching a new hook 336 */ 337static int 338ng_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] == '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|M_ZERO); 359 if (priv->links[linkNum] == NULL) 360 return (ENOMEM); 361 priv->links[linkNum]->hook = hook; 362 LINK_NUM(hook) = linkNum; 363 priv->numLinks++; 364 return (0); 365 } 366 367 /* Unknown hook name */ 368 return (EINVAL); 369} 370 371/* 372 * Receive a control message 373 */ 374static int 375ng_bridge_rcvmsg(node_p node, struct ng_mesg *msg, const char *retaddr, 376 struct ng_mesg **rptr, hook_p lasthook) 377{ 378 const priv_p priv = node->private; 379 struct ng_mesg *resp = NULL; 380 int error = 0; 381 382 switch (msg->header.typecookie) { 383 case NGM_BRIDGE_COOKIE: 384 switch (msg->header.cmd) { 385 case NGM_BRIDGE_GET_CONFIG: 386 { 387 struct ng_bridge_config *conf; 388 389 NG_MKRESPONSE(resp, msg, 390 sizeof(struct ng_bridge_config), M_NOWAIT); 391 if (resp == NULL) { 392 error = ENOMEM; 393 break; 394 } 395 conf = (struct ng_bridge_config *)resp->data; 396 *conf = priv->conf; /* no sanity checking needed */ 397 break; 398 } 399 case NGM_BRIDGE_SET_CONFIG: 400 { 401 struct ng_bridge_config *conf; 402 int i; 403 404 if (msg->header.arglen 405 != sizeof(struct ng_bridge_config)) { 406 error = EINVAL; 407 break; 408 } 409 conf = (struct ng_bridge_config *)msg->data; 410 priv->conf = *conf; 411 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) 412 priv->conf.ipfw[i] = !!priv->conf.ipfw[i]; 413 break; 414 } 415 case NGM_BRIDGE_RESET: 416 { 417 int i; 418 419 /* Flush all entries in the hash table */ 420 ng_bridge_remove_hosts(priv, -1); 421 422 /* Reset all loop detection counters and stats */ 423 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) { 424 if (priv->links[i] == NULL) 425 continue; 426 priv->links[i]->loopCount = 0; 427 bzero(&priv->links[i]->stats, 428 sizeof(priv->links[i]->stats)); 429 } 430 break; 431 } 432 case NGM_BRIDGE_GET_STATS: 433 case NGM_BRIDGE_CLR_STATS: 434 case NGM_BRIDGE_GETCLR_STATS: 435 { 436 struct ng_bridge_link *link; 437 int linkNum; 438 439 /* Get link number */ 440 if (msg->header.arglen != sizeof(u_int32_t)) { 441 error = EINVAL; 442 break; 443 } 444 linkNum = *((u_int32_t *)msg->data); 445 if (linkNum < 0 || linkNum >= NG_BRIDGE_MAX_LINKS) { 446 error = EINVAL; 447 break; 448 } 449 if ((link = priv->links[linkNum]) == NULL) { 450 error = ENOTCONN; 451 break; 452 } 453 454 /* Get/clear stats */ 455 if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) { 456 NG_MKRESPONSE(resp, msg, 457 sizeof(link->stats), M_NOWAIT); 458 if (resp == NULL) { 459 error = ENOMEM; 460 break; 461 } 462 bcopy(&link->stats, 463 resp->data, sizeof(link->stats)); 464 } 465 if (msg->header.cmd != NGM_BRIDGE_GET_STATS) 466 bzero(&link->stats, sizeof(link->stats)); 467 break; 468 } 469 case NGM_BRIDGE_GET_TABLE: 470 { 471 struct ng_bridge_host_ary *ary; 472 struct ng_bridge_hent *hent; 473 int i = 0, bucket; 474 475 NG_MKRESPONSE(resp, msg, sizeof(*ary) 476 + (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT); 477 if (resp == NULL) { 478 error = ENOMEM; 479 break; 480 } 481 ary = (struct ng_bridge_host_ary *)resp->data; 482 ary->numHosts = priv->numHosts; 483 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 484 SLIST_FOREACH(hent, &priv->tab[bucket], next) 485 ary->hosts[i++] = hent->host; 486 } 487 break; 488 } 489 default: 490 error = EINVAL; 491 break; 492 } 493 break; 494 default: 495 error = EINVAL; 496 break; 497 } 498 499 /* Done */ 500 if (rptr) 501 *rptr = resp; 502 else if (resp != NULL) 503 FREE(resp, M_NETGRAPH); 504 FREE(msg, M_NETGRAPH); 505 return (error); 506} 507 508/* 509 * Receive data on a hook 510 */ 511static int 512ng_bridge_rcvdata(hook_p hook, struct mbuf *m, meta_p meta, 513 struct mbuf **ret_m, meta_p *ret_meta, struct ng_mesg **resp) 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 i, manycast; 522 523 /* Get link number */ 524 linkNum = LINK_NUM(hook); 525 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 526 ("%s: linkNum=%u", __FUNCTION__, linkNum)); 527 link = priv->links[linkNum]; 528 KASSERT(link != NULL, ("%s: link%d null", __FUNCTION__, linkNum)); 529 530 /* Sanity check packet and pull up header */ 531 if (m->m_pkthdr.len < ETHER_HDR_LEN) { 532 link->stats.recvRunts++; 533 NG_FREE_DATA(m, meta); 534 return (EINVAL); 535 } 536 if (m->m_len < ETHER_HDR_LEN && !(m = m_pullup(m, ETHER_HDR_LEN))) { 537 link->stats.memoryFailures++; 538 NG_FREE_META(meta); 539 return (ENOBUFS); 540 } 541 eh = mtod(m, struct ether_header *); 542 if ((eh->ether_shost[0] & 1) != 0) { 543 link->stats.recvInvalid++; 544 NG_FREE_DATA(m, meta); 545 return (EINVAL); 546 } 547 548 /* Is link disabled due to a loopback condition? */ 549 if (link->loopCount != 0) { 550 link->stats.loopDrops++; 551 NG_FREE_DATA(m, meta); 552 return (ELOOP); /* XXX is this an appropriate error? */ 553 } 554 555 /* Update stats */ 556 link->stats.recvPackets++; 557 link->stats.recvOctets += m->m_pkthdr.len; 558 if ((manycast = (eh->ether_dhost[0] & 1)) != 0) { 559 if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) { 560 link->stats.recvBroadcasts++; 561 manycast = 2; 562 } else 563 link->stats.recvMulticasts++; 564 } 565 566 /* Look up packet's source Ethernet address in hashtable */ 567 if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) { 568 569 /* Update time since last heard from this host */ 570 host->staleness = 0; 571 572 /* Did host jump to a different link? */ 573 if (host->linkNum != linkNum) { 574 575 /* 576 * If the host's old link was recently established 577 * on the old link and it's already jumped to a new 578 * link, declare a loopback condition. 579 */ 580 if (host->age < priv->conf.minStableAge) { 581 582 /* Log the problem */ 583 if (priv->conf.debugLevel >= 2) { 584 struct ifnet *ifp = m->m_pkthdr.rcvif; 585 char suffix[32]; 586 587 if (ifp != NULL) 588 snprintf(suffix, sizeof(suffix), 589 " (%s%d)", ifp->if_name, 590 ifp->if_unit); 591 else 592 *suffix = '\0'; 593 log(LOG_WARNING, "ng_bridge: %s:" 594 " loopback detected on %s%s\n", 595 ng_bridge_nodename(node), 596 hook->name, suffix); 597 } 598 599 /* Mark link as linka non grata */ 600 link->loopCount = priv->conf.loopTimeout; 601 link->stats.loopDetects++; 602 603 /* Forget all hosts on this link */ 604 ng_bridge_remove_hosts(priv, linkNum); 605 606 /* Drop packet */ 607 link->stats.loopDrops++; 608 NG_FREE_DATA(m, meta); 609 return (ELOOP); /* XXX appropriate? */ 610 } 611 612 /* Move host over to new link */ 613 host->linkNum = linkNum; 614 host->age = 0; 615 } 616 } else { 617 if (!ng_bridge_put(priv, eh->ether_shost, linkNum)) { 618 link->stats.memoryFailures++; 619 NG_FREE_DATA(m, meta); 620 return (ENOMEM); 621 } 622 } 623 624 /* Run packet through ipfw processing, if enabled */ 625 if (priv->conf.ipfw[linkNum] && fw_enable && ip_fw_chk_ptr != NULL) { 626 /* XXX not implemented yet */ 627 } 628 629 /* 630 * If unicast and destination host known, deliver to host's link, 631 * unless it is the same link as the packet came in on. 632 */ 633 if (!manycast) { 634 635 /* Determine packet destination link */ 636 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) { 637 struct ng_bridge_link *const destLink 638 = priv->links[host->linkNum]; 639 640 /* If destination same as incoming link, do nothing */ 641 KASSERT(destLink != NULL, 642 ("%s: link%d null", __FUNCTION__, host->linkNum)); 643 if (destLink == link) { 644 NG_FREE_DATA(m, meta); 645 return (0); 646 } 647 648 /* Deliver packet out the destination link */ 649 destLink->stats.xmitPackets++; 650 destLink->stats.xmitOctets += m->m_pkthdr.len; 651 NG_SEND_DATA(error, destLink->hook, m, meta); 652 return (error); 653 } 654 655 /* Destination host is not known */ 656 link->stats.recvUnknown++; 657 } 658 659 /* Distribute unknown, multicast, broadcast pkts to all other links */ 660 for (linkNum = i = 0; i < priv->numLinks - 1; linkNum++) { 661 struct ng_bridge_link *const destLink = priv->links[linkNum]; 662 meta_p meta2 = NULL; 663 struct mbuf *m2; 664 665 /* Skip incoming link and disconnected links */ 666 if (destLink == NULL || destLink == link) 667 continue; 668 669 /* Copy mbuf and meta info */ 670 if (++i == priv->numLinks - 1) { /* last link */ 671 m2 = m; 672 meta2 = meta; 673 } else { 674 m2 = m_dup(m, M_NOWAIT); /* XXX m_copypacket() */ 675 if (m2 == NULL) { 676 link->stats.memoryFailures++; 677 NG_FREE_DATA(m, meta); 678 return (ENOBUFS); 679 } 680 if (meta != NULL 681 && (meta2 = ng_copy_meta(meta)) == NULL) { 682 link->stats.memoryFailures++; 683 m_freem(m2); 684 NG_FREE_DATA(m, meta); 685 return (ENOMEM); 686 } 687 } 688 689 /* Update stats */ 690 destLink->stats.xmitPackets++; 691 destLink->stats.xmitOctets += m->m_pkthdr.len; 692 switch (manycast) { 693 case 0: /* unicast */ 694 break; 695 case 1: /* multicast */ 696 destLink->stats.xmitMulticasts++; 697 break; 698 case 2: /* broadcast */ 699 destLink->stats.xmitBroadcasts++; 700 break; 701 } 702 703 /* Send packet */ 704 NG_SEND_DATA(error, destLink->hook, m2, meta2); 705 } 706 return (error); 707} 708 709/* 710 * Shutdown node 711 */ 712static int 713ng_bridge_rmnode(node_p node) 714{ 715 const priv_p priv = node->private; 716 717 ng_unname(node); 718 ng_cutlinks(node); /* frees all link and host info */ 719 KASSERT(priv->numLinks == 0 && priv->numHosts == 0, 720 ("%s: numLinks=%d numHosts=%d", 721 __FUNCTION__, priv->numLinks, priv->numHosts)); 722 FREE(priv->tab, M_NETGRAPH); 723 FREE(priv, M_NETGRAPH); 724 node->private = NULL; 725 ng_unref(node); 726 return (0); 727} 728 729/* 730 * Hook disconnection. 731 */ 732static int 733ng_bridge_disconnect(hook_p hook) 734{ 735 const priv_p priv = hook->node->private; 736 int linkNum; 737 738 /* Get link number */ 739 linkNum = LINK_NUM(hook); 740 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 741 ("%s: linkNum=%u", __FUNCTION__, linkNum)); 742 743 /* Remove all hosts associated with this link */ 744 ng_bridge_remove_hosts(priv, linkNum); 745 746 /* Free associated link information */ 747 KASSERT(priv->links[linkNum] != NULL, ("%s: no link", __FUNCTION__)); 748 FREE(priv->links[linkNum], M_NETGRAPH); 749 priv->links[linkNum] = NULL; 750 priv->numLinks--; 751 752 /* If no more hooks, go away */ 753 if (hook->node->numhooks == 0) 754 ng_rmnode(hook->node); 755 return (0); 756} 757 758/****************************************************************** 759 HASH TABLE FUNCTIONS 760******************************************************************/ 761 762/* 763 * Hash algorithm 764 * 765 * Only hashing bytes 3-6 of the Ethernet address is sufficient and fast. 766 */ 767#define HASH(addr,mask) ( (((const u_int16_t *)(addr))[0] \ 768 ^ ((const u_int16_t *)(addr))[1] \ 769 ^ ((const u_int16_t *)(addr))[2]) & (mask) ) 770 771/* 772 * Find a host entry in the table. 773 */ 774static struct ng_bridge_host * 775ng_bridge_get(priv_p priv, const u_char *addr) 776{ 777 const int bucket = HASH(addr, priv->hashMask); 778 struct ng_bridge_hent *hent; 779 780 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 781 if (ETHER_EQUAL(hent->host.addr, addr)) 782 return (&hent->host); 783 } 784 return (NULL); 785} 786 787/* 788 * Add a new host entry to the table. This assumes the host doesn't 789 * already exist in the table. Returns 1 on success, 0 if there 790 * was a memory allocation failure. 791 */ 792static int 793ng_bridge_put(priv_p priv, const u_char *addr, int linkNum) 794{ 795 const int bucket = HASH(addr, priv->hashMask); 796 struct ng_bridge_hent *hent; 797 798#ifdef INVARIANTS 799 /* Assert that entry does not already exist in hashtable */ 800 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 801 KASSERT(!ETHER_EQUAL(hent->host.addr, addr), 802 ("%s: entry %6D exists in table", __FUNCTION__, addr, ":")); 803 } 804#endif 805 806 /* Allocate and initialize new hashtable entry */ 807 MALLOC(hent, struct ng_bridge_hent *, 808 sizeof(*hent), M_NETGRAPH, M_NOWAIT); 809 if (hent == NULL) 810 return (0); 811 bcopy(addr, hent->host.addr, ETHER_ADDR_LEN); 812 hent->host.linkNum = linkNum; 813 hent->host.staleness = 0; 814 hent->host.age = 0; 815 816 /* Add new element to hash bucket */ 817 SLIST_INSERT_HEAD(&priv->tab[bucket], hent, next); 818 priv->numHosts++; 819 820 /* Resize table if necessary */ 821 ng_bridge_rehash(priv); 822 return (1); 823} 824 825/* 826 * Resize the hash table. We try to maintain the number of buckets 827 * such that the load factor is in the range 0.25 to 1.0. 828 * 829 * If we can't get the new memory then we silently fail. This is OK 830 * because things will still work and we'll try again soon anyway. 831 */ 832static void 833ng_bridge_rehash(priv_p priv) 834{ 835 struct ng_bridge_bucket *newTab; 836 int oldBucket, newBucket; 837 int newNumBuckets; 838 u_int newMask; 839 840 /* Is table too full or too empty? */ 841 if (priv->numHosts > priv->numBuckets 842 && (priv->numBuckets << 1) <= MAX_BUCKETS) 843 newNumBuckets = priv->numBuckets << 1; 844 else if (priv->numHosts < (priv->numBuckets >> 2) 845 && (priv->numBuckets >> 2) >= MIN_BUCKETS) 846 newNumBuckets = priv->numBuckets >> 2; 847 else 848 return; 849 newMask = newNumBuckets - 1; 850 851 /* Allocate and initialize new table */ 852 MALLOC(newTab, struct ng_bridge_bucket *, 853 newNumBuckets * sizeof(*newTab), M_NETGRAPH, M_NOWAIT | M_ZERO); 854 if (newTab == NULL) 855 return; 856 857 /* Move all entries from old table to new table */ 858 for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) { 859 struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket]; 860 861 while (!SLIST_EMPTY(oldList)) { 862 struct ng_bridge_hent *const hent 863 = SLIST_FIRST(oldList); 864 865 SLIST_REMOVE_HEAD(oldList, next); 866 newBucket = HASH(hent->host.addr, newMask); 867 SLIST_INSERT_HEAD(&newTab[newBucket], hent, next); 868 } 869 } 870 871 /* Replace old table with new one */ 872 if (priv->conf.debugLevel >= 3) { 873 log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n", 874 ng_bridge_nodename(priv->node), 875 priv->numBuckets, newNumBuckets); 876 } 877 FREE(priv->tab, M_NETGRAPH); 878 priv->numBuckets = newNumBuckets; 879 priv->hashMask = newMask; 880 priv->tab = newTab; 881 return; 882} 883 884/****************************************************************** 885 MISC FUNCTIONS 886******************************************************************/ 887 888/* 889 * Remove all hosts associated with a specific link from the hashtable. 890 * If linkNum == -1, then remove all hosts in the table. 891 */ 892static void 893ng_bridge_remove_hosts(priv_p priv, int linkNum) 894{ 895 int bucket; 896 897 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 898 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 899 900 while (*hptr != NULL) { 901 struct ng_bridge_hent *const hent = *hptr; 902 903 if (linkNum == -1 || hent->host.linkNum == linkNum) { 904 *hptr = SLIST_NEXT(hent, next); 905 FREE(hent, M_NETGRAPH); 906 priv->numHosts--; 907 } else 908 hptr = &SLIST_NEXT(hent, next); 909 } 910 } 911} 912 913/* 914 * Handle our once-per-second timeout event. We do two things: 915 * we decrement link->loopCount for those links being muted due to 916 * a detected loopback condition, and we remove any hosts from 917 * the hashtable whom we haven't heard from in a long while. 918 */ 919static void 920ng_bridge_timeout(void *arg) 921{ 922 const node_p node = arg; 923 const priv_p priv = node->private; 924 int s, bucket; 925 int counter = 0; 926 int linkNum; 927 928 /* Avoid race condition with ng_bridge_shutdown() */ 929 s = splnet(); 930 if ((node->flags & NG_INVALID) != 0 || priv == NULL) { 931 ng_unref(node); 932 splx(s); 933 return; 934 } 935 936 /* Register a new timeout, keeping the existing node reference */ 937 callout_reset(&priv->timer, hz, ng_bridge_timeout, node); 938 939 /* Update host time counters and remove stale entries */ 940 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 941 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 942 943 while (*hptr != NULL) { 944 struct ng_bridge_hent *const hent = *hptr; 945 946 /* Make sure host's link really exists */ 947 KASSERT(priv->links[hent->host.linkNum] != NULL, 948 ("%s: host %6D on nonexistent link %d\n", 949 __FUNCTION__, hent->host.addr, ":", 950 hent->host.linkNum)); 951 952 /* Remove hosts we haven't heard from in a while */ 953 if (++hent->host.staleness >= priv->conf.maxStaleness) { 954 *hptr = SLIST_NEXT(hent, next); 955 FREE(hent, M_NETGRAPH); 956 priv->numHosts--; 957 } else { 958 if (hent->host.age < 0xffff) 959 hent->host.age++; 960 hptr = &SLIST_NEXT(hent, next); 961 counter++; 962 } 963 } 964 } 965 KASSERT(priv->numHosts == counter, 966 ("%s: hosts: %d != %d", __FUNCTION__, priv->numHosts, counter)); 967 968 /* Decrease table size if necessary */ 969 ng_bridge_rehash(priv); 970 971 /* Decrease loop counter on muted looped back links */ 972 for (counter = linkNum = 0; linkNum < NG_BRIDGE_MAX_LINKS; linkNum++) { 973 struct ng_bridge_link *const link = priv->links[linkNum]; 974 975 if (link != NULL) { 976 if (link->loopCount != 0) { 977 link->loopCount--; 978 if (link->loopCount == 0 979 && priv->conf.debugLevel >= 2) { 980 log(LOG_INFO, "ng_bridge: %s:" 981 " restoring looped back link%d\n", 982 ng_bridge_nodename(node), linkNum); 983 } 984 } 985 counter++; 986 } 987 } 988 KASSERT(priv->numLinks == counter, 989 ("%s: links: %d != %d", __FUNCTION__, priv->numLinks, counter)); 990 991 /* Done */ 992 splx(s); 993} 994 995/* 996 * Return node's "name", even if it doesn't have one. 997 */ 998static const char * 999ng_bridge_nodename(node_p node) 1000{ 1001 static char name[NG_NODELEN+1]; 1002 1003 if (node->name != NULL) 1004 snprintf(name, sizeof(name), "%s", node->name); 1005 else 1006 snprintf(name, sizeof(name), "[%x]", ng_node2ID(node)); 1007 return name; 1008} 1009
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