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: src/sys/netgraph/ng_bridge.c,v 1.1.2.5 2002/07/02 23:44:02 archie Exp $ 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 #include <sys/thread2.h> 70 71 #include <net/if.h> 72 #include <net/ethernet.h> 73 74 #include <netinet/in.h> 75 #include <net/ipfw/ip_fw.h> 76 77 #include <netgraph/ng_message.h> 78 #include <netgraph/netgraph.h> 79 #include <netgraph/ng_parse.h> 80 #include "ng_bridge.h" 81 #include <netgraph/ether/ng_ether.h> 82 83 /* Per-link private data */ 84 struct ng_bridge_link { 85 hook_p hook; /* netgraph hook */ 86 u_int16_t loopCount; /* loop ignore timer */ 87 struct ng_bridge_link_stats stats; /* link stats */ 88 }; 89 90 /* Per-node private data */ 91 struct ng_bridge_private { 92 struct ng_bridge_bucket *tab; /* hash table bucket array */ 93 struct ng_bridge_link *links[NG_BRIDGE_MAX_LINKS]; 94 struct ng_bridge_config conf; /* node configuration */ 95 node_p node; /* netgraph node */ 96 u_int numHosts; /* num entries in table */ 97 u_int numBuckets; /* num buckets in table */ 98 u_int hashMask; /* numBuckets - 1 */ 99 int numLinks; /* num connected links */ 100 struct callout timer; /* one second periodic timer */ 101 }; 102 typedef struct ng_bridge_private *priv_p; 103 104 /* Information about a host, stored in a hash table entry */ 105 struct ng_bridge_hent { 106 struct ng_bridge_host host; /* actual host info */ 107 SLIST_ENTRY(ng_bridge_hent) next; /* next entry in bucket */ 108 }; 109 110 /* Hash table bucket declaration */ 111 SLIST_HEAD(ng_bridge_bucket, ng_bridge_hent); 112 113 /* Netgraph node methods */ 114 static ng_constructor_t ng_bridge_constructor; 115 static ng_rcvmsg_t ng_bridge_rcvmsg; 116 static ng_shutdown_t ng_bridge_rmnode; 117 static ng_newhook_t ng_bridge_newhook; 118 static ng_rcvdata_t ng_bridge_rcvdata; 119 static ng_disconnect_t ng_bridge_disconnect; 120 121 /* Other internal functions */ 122 static struct ng_bridge_host *ng_bridge_get(priv_p priv, const u_char *addr); 123 static int ng_bridge_put(priv_p priv, const u_char *addr, int linkNum); 124 static void ng_bridge_rehash(priv_p priv); 125 static void ng_bridge_remove_hosts(priv_p priv, int linkNum); 126 static void ng_bridge_timeout(void *arg); 127 static const char *ng_bridge_nodename(node_p node); 128 129 /* Ethernet broadcast */ 130 static const u_char ng_bridge_bcast_addr[ETHER_ADDR_LEN] = 131 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; 132 133 /* Store each hook's link number in the private field */ 134 #define LINK_NUM(hook) (*(u_int16_t *)(&(hook)->private)) 135 136 /* Compare Ethernet addresses using 32 and 16 bit words instead of bytewise */ 137 #define ETHER_EQUAL(a,b) (((const u_int32_t *)(a))[0] \ 138 == ((const u_int32_t *)(b))[0] \ 139 && ((const u_int16_t *)(a))[2] \ 140 == ((const u_int16_t *)(b))[2]) 141 142 /* Minimum and maximum number of hash buckets. Must be a power of two. */ 143 #define MIN_BUCKETS (1 << 5) /* 32 */ 144 #define MAX_BUCKETS (1 << 14) /* 16384 */ 145 146 /* Configuration default values */ 147 #define DEFAULT_LOOP_TIMEOUT 60 148 #define DEFAULT_MAX_STALENESS (15 * 60) /* same as ARP timeout */ 149 #define DEFAULT_MIN_STABLE_AGE 1 150 151 /****************************************************************** 152 NETGRAPH PARSE TYPES 153 ******************************************************************/ 154 155 /* 156 * How to determine the length of the table returned by NGM_BRIDGE_GET_TABLE 157 */ 158 static int 159 ng_bridge_getTableLength(const struct ng_parse_type *type, 160 const u_char *start, const u_char *buf) 161 { 162 const struct ng_bridge_host_ary *const hary 163 = (const struct ng_bridge_host_ary *)(buf - sizeof(u_int32_t)); 164 165 return hary->numHosts; 166 } 167 168 /* Parse type for struct ng_bridge_host_ary */ 169 static const struct ng_parse_struct_field ng_bridge_host_type_fields[] 170 = NG_BRIDGE_HOST_TYPE_INFO(&ng_ether_enaddr_type); 171 static const struct ng_parse_type ng_bridge_host_type = { 172 &ng_parse_struct_type, 173 &ng_bridge_host_type_fields 174 }; 175 static const struct ng_parse_array_info ng_bridge_hary_type_info = { 176 &ng_bridge_host_type, 177 ng_bridge_getTableLength 178 }; 179 static const struct ng_parse_type ng_bridge_hary_type = { 180 &ng_parse_array_type, 181 &ng_bridge_hary_type_info 182 }; 183 static const struct ng_parse_struct_field ng_bridge_host_ary_type_fields[] 184 = NG_BRIDGE_HOST_ARY_TYPE_INFO(&ng_bridge_hary_type); 185 static const struct ng_parse_type ng_bridge_host_ary_type = { 186 &ng_parse_struct_type, 187 &ng_bridge_host_ary_type_fields 188 }; 189 190 /* Parse type for struct ng_bridge_config */ 191 static const struct ng_parse_fixedarray_info ng_bridge_ipfwary_type_info = { 192 &ng_parse_uint8_type, 193 NG_BRIDGE_MAX_LINKS 194 }; 195 static const struct ng_parse_type ng_bridge_ipfwary_type = { 196 &ng_parse_fixedarray_type, 197 &ng_bridge_ipfwary_type_info 198 }; 199 static const struct ng_parse_struct_field ng_bridge_config_type_fields[] 200 = NG_BRIDGE_CONFIG_TYPE_INFO(&ng_bridge_ipfwary_type); 201 static const struct ng_parse_type ng_bridge_config_type = { 202 &ng_parse_struct_type, 203 &ng_bridge_config_type_fields 204 }; 205 206 /* Parse type for struct ng_bridge_link_stat */ 207 static const struct ng_parse_struct_field ng_bridge_stats_type_fields[] 208 = NG_BRIDGE_STATS_TYPE_INFO; 209 static const struct ng_parse_type ng_bridge_stats_type = { 210 &ng_parse_struct_type, 211 &ng_bridge_stats_type_fields 212 }; 213 214 /* List of commands and how to convert arguments to/from ASCII */ 215 static const struct ng_cmdlist ng_bridge_cmdlist[] = { 216 { 217 NGM_BRIDGE_COOKIE, 218 NGM_BRIDGE_SET_CONFIG, 219 "setconfig", 220 &ng_bridge_config_type, 221 NULL 222 }, 223 { 224 NGM_BRIDGE_COOKIE, 225 NGM_BRIDGE_GET_CONFIG, 226 "getconfig", 227 NULL, 228 &ng_bridge_config_type 229 }, 230 { 231 NGM_BRIDGE_COOKIE, 232 NGM_BRIDGE_RESET, 233 "reset", 234 NULL, 235 NULL 236 }, 237 { 238 NGM_BRIDGE_COOKIE, 239 NGM_BRIDGE_GET_STATS, 240 "getstats", 241 &ng_parse_uint32_type, 242 &ng_bridge_stats_type 243 }, 244 { 245 NGM_BRIDGE_COOKIE, 246 NGM_BRIDGE_CLR_STATS, 247 "clrstats", 248 &ng_parse_uint32_type, 249 NULL 250 }, 251 { 252 NGM_BRIDGE_COOKIE, 253 NGM_BRIDGE_GETCLR_STATS, 254 "getclrstats", 255 &ng_parse_uint32_type, 256 &ng_bridge_stats_type 257 }, 258 { 259 NGM_BRIDGE_COOKIE, 260 NGM_BRIDGE_GET_TABLE, 261 "gettable", 262 NULL, 263 &ng_bridge_host_ary_type 264 }, 265 { 0 } 266 }; 267 268 /* Node type descriptor */ 269 static struct ng_type ng_bridge_typestruct = { 270 NG_VERSION, 271 NG_BRIDGE_NODE_TYPE, 272 NULL, 273 ng_bridge_constructor, 274 ng_bridge_rcvmsg, 275 ng_bridge_rmnode, 276 ng_bridge_newhook, 277 NULL, 278 NULL, 279 ng_bridge_rcvdata, 280 ng_bridge_rcvdata, 281 ng_bridge_disconnect, 282 ng_bridge_cmdlist, 283 }; 284 NETGRAPH_INIT(bridge, &ng_bridge_typestruct); 285 286 /* Depend on ng_ether so we can use the Ethernet parse type */ 287 MODULE_DEPEND(ng_bridge, ng_ether, NG_ABI_VERSION, NG_ABI_VERSION, NG_ABI_VERSION); 288 289 /****************************************************************** 290 NETGRAPH NODE METHODS 291 ******************************************************************/ 292 293 /* 294 * Node constructor 295 */ 296 static int 297 ng_bridge_constructor(node_p *nodep) 298 { 299 priv_p priv; 300 int error; 301 302 /* Allocate and initialize private info */ 303 priv = kmalloc(sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO); 304 if (priv == NULL) 305 return (ENOMEM); 306 callout_init(&priv->timer); 307 308 /* Allocate and initialize hash table, etc. */ 309 priv->tab = kmalloc(MIN_BUCKETS * sizeof(*priv->tab), M_NETGRAPH, 310 M_NOWAIT | M_ZERO); 311 if (priv->tab == NULL) { 312 kfree(priv, M_NETGRAPH); 313 return (ENOMEM); 314 } 315 priv->numBuckets = MIN_BUCKETS; 316 priv->hashMask = MIN_BUCKETS - 1; 317 priv->conf.debugLevel = 1; 318 priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT; 319 priv->conf.maxStaleness = DEFAULT_MAX_STALENESS; 320 priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE; 321 322 /* Call superclass constructor */ 323 if ((error = ng_make_node_common(&ng_bridge_typestruct, nodep))) { 324 kfree(priv, M_NETGRAPH); 325 return (error); 326 } 327 (*nodep)->private = priv; 328 priv->node = *nodep; 329 330 /* Start timer; timer is always running while node is alive */ 331 callout_reset(&priv->timer, hz, ng_bridge_timeout, priv->node); 332 333 /* Done */ 334 return (0); 335 } 336 337 /* 338 * Method for attaching a new hook 339 */ 340 static int 341 ng_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 priv->links[linkNum] = kmalloc(sizeof(*priv->links[linkNum]), 361 M_NETGRAPH, M_NOWAIT); 362 if (priv->links[linkNum] == NULL) 363 return (ENOMEM); 364 bzero(priv->links[linkNum], sizeof(*priv->links[linkNum])); 365 priv->links[linkNum]->hook = hook; 366 LINK_NUM(hook) = linkNum; 367 priv->numLinks++; 368 return (0); 369 } 370 371 /* Unknown hook name */ 372 return (EINVAL); 373 } 374 375 /* 376 * Receive a control message 377 */ 378 static int 379 ng_bridge_rcvmsg(node_p node, struct ng_mesg *msg, 380 const char *retaddr, struct ng_mesg **rptr) 381 { 382 const priv_p priv = node->private; 383 struct ng_mesg *resp = NULL; 384 int error = 0; 385 386 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 if (rptr) 505 *rptr = resp; 506 else if (resp != NULL) 507 kfree(resp, M_NETGRAPH); 508 kfree(msg, M_NETGRAPH); 509 return (error); 510 } 511 512 /* 513 * Receive data on a hook 514 */ 515 static int 516 ng_bridge_rcvdata(hook_p hook, struct mbuf *m, meta_p meta) 517 { 518 const node_p node = hook->node; 519 const priv_p priv = node->private; 520 struct ng_bridge_host *host; 521 struct ng_bridge_link *link; 522 struct ether_header *eh; 523 int error = 0, linkNum; 524 int i, manycast; 525 526 /* Get link number */ 527 linkNum = LINK_NUM(hook); 528 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 529 ("%s: linkNum=%u", __func__, linkNum)); 530 link = priv->links[linkNum]; 531 KASSERT(link != NULL, ("%s: link%d null", __func__, linkNum)); 532 533 /* Sanity check packet and pull up header */ 534 if (m->m_pkthdr.len < ETHER_HDR_LEN) { 535 link->stats.recvRunts++; 536 NG_FREE_DATA(m, meta); 537 return (EINVAL); 538 } 539 if (m->m_len < ETHER_HDR_LEN && !(m = m_pullup(m, ETHER_HDR_LEN))) { 540 link->stats.memoryFailures++; 541 NG_FREE_META(meta); 542 return (ENOBUFS); 543 } 544 eh = mtod(m, struct ether_header *); 545 if ((eh->ether_shost[0] & 1) != 0) { 546 link->stats.recvInvalid++; 547 NG_FREE_DATA(m, meta); 548 return (EINVAL); 549 } 550 551 /* Is link disabled due to a loopback condition? */ 552 if (link->loopCount != 0) { 553 link->stats.loopDrops++; 554 NG_FREE_DATA(m, meta); 555 return (ELOOP); /* XXX is this an appropriate error? */ 556 } 557 558 /* Update stats */ 559 link->stats.recvPackets++; 560 link->stats.recvOctets += m->m_pkthdr.len; 561 if ((manycast = (eh->ether_dhost[0] & 1)) != 0) { 562 if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) { 563 link->stats.recvBroadcasts++; 564 manycast = 2; 565 } else 566 link->stats.recvMulticasts++; 567 } 568 569 /* Look up packet's source Ethernet address in hashtable */ 570 if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) { 571 572 /* Update time since last heard from this host */ 573 host->staleness = 0; 574 575 /* Did host jump to a different link? */ 576 if (host->linkNum != linkNum) { 577 578 /* 579 * If the host's old link was recently established 580 * on the old link and it's already jumped to a new 581 * link, declare a loopback condition. 582 */ 583 if (host->age < priv->conf.minStableAge) { 584 585 /* Log the problem */ 586 if (priv->conf.debugLevel >= 2) { 587 struct ifnet *ifp = m->m_pkthdr.rcvif; 588 char suffix[32]; 589 590 if (ifp != NULL) 591 ksnprintf(suffix, sizeof(suffix), 592 " (%s)", ifp->if_xname); 593 else 594 *suffix = '\0'; 595 log(LOG_WARNING, "ng_bridge: %s:" 596 " loopback detected on %s%s\n", 597 ng_bridge_nodename(node), 598 hook->name, suffix); 599 } 600 601 /* Mark link as linka non grata */ 602 link->loopCount = priv->conf.loopTimeout; 603 link->stats.loopDetects++; 604 605 /* Forget all hosts on this link */ 606 ng_bridge_remove_hosts(priv, linkNum); 607 608 /* Drop packet */ 609 link->stats.loopDrops++; 610 NG_FREE_DATA(m, meta); 611 return (ELOOP); /* XXX appropriate? */ 612 } 613 614 /* Move host over to new link */ 615 host->linkNum = linkNum; 616 host->age = 0; 617 } 618 } else { 619 if (!ng_bridge_put(priv, eh->ether_shost, linkNum)) { 620 link->stats.memoryFailures++; 621 NG_FREE_DATA(m, meta); 622 return (ENOMEM); 623 } 624 } 625 626 /* Run packet through ipfw processing, if enabled */ 627 if (priv->conf.ipfw[linkNum] && fw_enable && ip_fw_chk_ptr != NULL) { 628 /* XXX not implemented yet */ 629 } 630 631 /* 632 * If unicast and destination host known, deliver to host's link, 633 * unless it is the same link as the packet came in on. 634 */ 635 if (!manycast) { 636 637 /* Determine packet destination link */ 638 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) { 639 struct ng_bridge_link *const destLink 640 = priv->links[host->linkNum]; 641 642 /* If destination same as incoming link, do nothing */ 643 KASSERT(destLink != NULL, 644 ("%s: link%d null", __func__, host->linkNum)); 645 if (destLink == link) { 646 NG_FREE_DATA(m, meta); 647 return (0); 648 } 649 650 /* Deliver packet out the destination link */ 651 destLink->stats.xmitPackets++; 652 destLink->stats.xmitOctets += m->m_pkthdr.len; 653 NG_SEND_DATA(error, destLink->hook, m, meta); 654 return (error); 655 } 656 657 /* Destination host is not known */ 658 link->stats.recvUnknown++; 659 } 660 661 /* Distribute unknown, multicast, broadcast pkts to all other links */ 662 for (linkNum = i = 0; i < priv->numLinks - 1; linkNum++) { 663 struct ng_bridge_link *const destLink = priv->links[linkNum]; 664 meta_p meta2 = NULL; 665 struct mbuf *m2; 666 667 /* Skip incoming link and disconnected links */ 668 if (destLink == NULL || destLink == link) 669 continue; 670 671 /* Copy mbuf and meta info */ 672 if (++i == priv->numLinks - 1) { /* last link */ 673 m2 = m; 674 meta2 = meta; 675 } else { 676 m2 = m_dup(m, M_NOWAIT); /* XXX m_copypacket() */ 677 if (m2 == NULL) { 678 link->stats.memoryFailures++; 679 NG_FREE_DATA(m, meta); 680 return (ENOBUFS); 681 } 682 if (meta != NULL 683 && (meta2 = ng_copy_meta(meta)) == NULL) { 684 link->stats.memoryFailures++; 685 m_freem(m2); 686 NG_FREE_DATA(m, meta); 687 return (ENOMEM); 688 } 689 } 690 691 /* Update stats */ 692 destLink->stats.xmitPackets++; 693 destLink->stats.xmitOctets += m->m_pkthdr.len; 694 switch (manycast) { 695 case 0: /* unicast */ 696 break; 697 case 1: /* multicast */ 698 destLink->stats.xmitMulticasts++; 699 break; 700 case 2: /* broadcast */ 701 destLink->stats.xmitBroadcasts++; 702 break; 703 } 704 705 /* Send packet */ 706 NG_SEND_DATA(error, destLink->hook, m2, meta2); 707 } 708 return (error); 709 } 710 711 /* 712 * Shutdown node 713 */ 714 static int 715 ng_bridge_rmnode(node_p node) 716 { 717 const priv_p priv = node->private; 718 719 /* 720 * Shut down everything except the timer. There's no way to 721 * avoid another possible timeout event (it may have already 722 * been dequeued), so we can't free the node yet. 723 */ 724 ng_unname(node); 725 ng_cutlinks(node); /* frees all link and host info */ 726 KASSERT(priv->numLinks == 0 && priv->numHosts == 0, 727 ("%s: numLinks=%d numHosts=%d", 728 __func__, priv->numLinks, priv->numHosts)); 729 kfree(priv->tab, M_NETGRAPH); 730 731 /* NG_INVALID flag is now set so node will be freed at next timeout */ 732 return (0); 733 } 734 735 /* 736 * Hook disconnection. 737 */ 738 static int 739 ng_bridge_disconnect(hook_p hook) 740 { 741 const priv_p priv = hook->node->private; 742 int linkNum; 743 744 /* Get link number */ 745 linkNum = LINK_NUM(hook); 746 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 747 ("%s: linkNum=%u", __func__, linkNum)); 748 749 /* Remove all hosts associated with this link */ 750 ng_bridge_remove_hosts(priv, linkNum); 751 752 /* Free associated link information */ 753 KASSERT(priv->links[linkNum] != NULL, ("%s: no link", __func__)); 754 kfree(priv->links[linkNum], M_NETGRAPH); 755 priv->links[linkNum] = NULL; 756 priv->numLinks--; 757 758 /* If no more hooks, go away */ 759 if (hook->node->numhooks == 0) 760 ng_rmnode(hook->node); 761 return (0); 762 } 763 764 /****************************************************************** 765 HASH TABLE FUNCTIONS 766 ******************************************************************/ 767 768 /* 769 * Hash algorithm 770 * 771 * Only hashing bytes 3-6 of the Ethernet address is sufficient and fast. 772 */ 773 #define HASH(addr,mask) ( (((const u_int16_t *)(addr))[0] \ 774 ^ ((const u_int16_t *)(addr))[1] \ 775 ^ ((const u_int16_t *)(addr))[2]) & (mask) ) 776 777 /* 778 * Find a host entry in the table. 779 */ 780 static struct ng_bridge_host * 781 ng_bridge_get(priv_p priv, const u_char *addr) 782 { 783 const int bucket = HASH(addr, priv->hashMask); 784 struct ng_bridge_hent *hent; 785 786 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 787 if (ETHER_EQUAL(hent->host.addr, addr)) 788 return (&hent->host); 789 } 790 return (NULL); 791 } 792 793 /* 794 * Add a new host entry to the table. This assumes the host doesn't 795 * already exist in the table. Returns 1 on success, 0 if there 796 * was a memory allocation failure. 797 */ 798 static int 799 ng_bridge_put(priv_p priv, const u_char *addr, int linkNum) 800 { 801 const int bucket = HASH(addr, priv->hashMask); 802 struct ng_bridge_hent *hent; 803 804 #ifdef INVARIANTS 805 char ethstr[ETHER_ADDRSTRLEN + 1]; 806 807 /* Assert that entry does not already exist in hashtable */ 808 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 809 KASSERT(!ETHER_EQUAL(hent->host.addr, addr), 810 ("%s: entry %s exists in table", __func__, kether_ntoa(addr, ethstr))); 811 } 812 #endif 813 814 /* Allocate and initialize new hashtable entry */ 815 hent = kmalloc(sizeof(*hent), M_NETGRAPH, M_NOWAIT); 816 if (hent == NULL) 817 return (0); 818 bcopy(addr, hent->host.addr, ETHER_ADDR_LEN); 819 hent->host.linkNum = linkNum; 820 hent->host.staleness = 0; 821 hent->host.age = 0; 822 823 /* Add new element to hash bucket */ 824 SLIST_INSERT_HEAD(&priv->tab[bucket], hent, next); 825 priv->numHosts++; 826 827 /* Resize table if necessary */ 828 ng_bridge_rehash(priv); 829 return (1); 830 } 831 832 /* 833 * Resize the hash table. We try to maintain the number of buckets 834 * such that the load factor is in the range 0.25 to 1.0. 835 * 836 * If we can't get the new memory then we silently fail. This is OK 837 * because things will still work and we'll try again soon anyway. 838 */ 839 static void 840 ng_bridge_rehash(priv_p priv) 841 { 842 struct ng_bridge_bucket *newTab; 843 int oldBucket, newBucket; 844 int newNumBuckets; 845 u_int newMask; 846 847 /* Is table too full or too empty? */ 848 if (priv->numHosts > priv->numBuckets 849 && (priv->numBuckets << 1) <= MAX_BUCKETS) 850 newNumBuckets = priv->numBuckets << 1; 851 else if (priv->numHosts < (priv->numBuckets >> 2) 852 && (priv->numBuckets >> 2) >= MIN_BUCKETS) 853 newNumBuckets = priv->numBuckets >> 2; 854 else 855 return; 856 newMask = newNumBuckets - 1; 857 858 /* Allocate and initialize new table */ 859 newTab = kmalloc(newNumBuckets * sizeof(*newTab), M_NETGRAPH, 860 M_NOWAIT | M_ZERO); 861 if (newTab == NULL) 862 return; 863 864 /* Move all entries from old table to new table */ 865 for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) { 866 struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket]; 867 868 while (!SLIST_EMPTY(oldList)) { 869 struct ng_bridge_hent *const hent 870 = SLIST_FIRST(oldList); 871 872 SLIST_REMOVE_HEAD(oldList, next); 873 newBucket = HASH(hent->host.addr, newMask); 874 SLIST_INSERT_HEAD(&newTab[newBucket], hent, next); 875 } 876 } 877 878 /* Replace old table with new one */ 879 if (priv->conf.debugLevel >= 3) { 880 log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n", 881 ng_bridge_nodename(priv->node), 882 priv->numBuckets, newNumBuckets); 883 } 884 kfree(priv->tab, M_NETGRAPH); 885 priv->numBuckets = newNumBuckets; 886 priv->hashMask = newMask; 887 priv->tab = newTab; 888 return; 889 } 890 891 /****************************************************************** 892 MISC FUNCTIONS 893 ******************************************************************/ 894 895 /* 896 * Remove all hosts associated with a specific link from the hashtable. 897 * If linkNum == -1, then remove all hosts in the table. 898 */ 899 static void 900 ng_bridge_remove_hosts(priv_p priv, int linkNum) 901 { 902 int bucket; 903 904 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 905 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 906 907 while (*hptr != NULL) { 908 struct ng_bridge_hent *const hent = *hptr; 909 910 if (linkNum == -1 || hent->host.linkNum == linkNum) { 911 *hptr = SLIST_NEXT(hent, next); 912 kfree(hent, M_NETGRAPH); 913 priv->numHosts--; 914 } else 915 hptr = &SLIST_NEXT(hent, next); 916 } 917 } 918 } 919 920 /* 921 * Handle our once-per-second timeout event. We do two things: 922 * we decrement link->loopCount for those links being muted due to 923 * a detected loopback condition, and we remove any hosts from 924 * the hashtable whom we haven't heard from in a long while. 925 * 926 * If the node has the NG_INVALID flag set, our job is to kill it. 927 */ 928 static void 929 ng_bridge_timeout(void *arg) 930 { 931 const node_p node = arg; 932 const priv_p priv = node->private; 933 int bucket; 934 int counter = 0; 935 int linkNum; 936 char ethstr[ETHER_ADDRSTRLEN + 1] __debugvar; 937 938 /* If node was shut down, this is the final lingering timeout */ 939 crit_enter(); 940 if ((node->flags & NG_INVALID) != 0) { 941 kfree(priv, M_NETGRAPH); 942 node->private = NULL; 943 ng_unref(node); 944 crit_exit(); 945 return; 946 } 947 948 /* Register a new timeout, keeping the existing node reference */ 949 callout_reset(&priv->timer, hz, ng_bridge_timeout, node); 950 951 /* Update host time counters and remove stale entries */ 952 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 953 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 954 955 while (*hptr != NULL) { 956 struct ng_bridge_hent *const hent = *hptr; 957 958 /* Make sure host's link really exists */ 959 KASSERT(priv->links[hent->host.linkNum] != NULL, 960 ("%s: host %s on nonexistent link %d", 961 __func__, kether_ntoa(hent->host.addr, ethstr), 962 hent->host.linkNum)); 963 964 /* Remove hosts we haven't heard from in a while */ 965 if (++hent->host.staleness >= priv->conf.maxStaleness) { 966 *hptr = SLIST_NEXT(hent, next); 967 kfree(hent, M_NETGRAPH); 968 priv->numHosts--; 969 } else { 970 if (hent->host.age < 0xffff) 971 hent->host.age++; 972 hptr = &SLIST_NEXT(hent, next); 973 counter++; 974 } 975 } 976 } 977 KASSERT(priv->numHosts == counter, 978 ("%s: hosts: %d != %d", __func__, priv->numHosts, counter)); 979 980 /* Decrease table size if necessary */ 981 ng_bridge_rehash(priv); 982 983 /* Decrease loop counter on muted looped back links */ 984 for (counter = linkNum = 0; linkNum < NG_BRIDGE_MAX_LINKS; linkNum++) { 985 struct ng_bridge_link *const link = priv->links[linkNum]; 986 987 if (link != NULL) { 988 if (link->loopCount != 0) { 989 link->loopCount--; 990 if (link->loopCount == 0 991 && priv->conf.debugLevel >= 2) { 992 log(LOG_INFO, "ng_bridge: %s:" 993 " restoring looped back link%d\n", 994 ng_bridge_nodename(node), linkNum); 995 } 996 } 997 counter++; 998 } 999 } 1000 KASSERT(priv->numLinks == counter, 1001 ("%s: links: %d != %d", __func__, priv->numLinks, counter)); 1002 1003 /* Done */ 1004 crit_exit(); 1005 } 1006 1007 /* 1008 * Return node's "name", even if it doesn't have one. 1009 */ 1010 static const char * 1011 ng_bridge_nodename(node_p node) 1012 { 1013 static char name[NG_NODESIZ]; 1014 1015 if (node->name != NULL) 1016 ksnprintf(name, sizeof(name), "%s", node->name); 1017 else 1018 ksnprintf(name, sizeof(name), "[%x]", ng_node2ID(node)); 1019 return name; 1020 } 1021 1022