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 * $DragonFly: src/sys/netgraph/bridge/ng_bridge.c,v 1.11 2008/01/05 14:02:39 swildner Exp $ 41 */ 42 43 /* 44 * ng_bridge(4) netgraph node type 45 * 46 * The node performs standard intelligent Ethernet bridging over 47 * each of its connected hooks, or links. A simple loop detection 48 * algorithm is included which disables a link for priv->conf.loopTimeout 49 * seconds when a host is seen to have jumped from one link to 50 * another within priv->conf.minStableAge seconds. 51 * 52 * We keep a hashtable that maps Ethernet addresses to host info, 53 * which is contained in struct ng_bridge_host's. These structures 54 * tell us on which link the host may be found. A host's entry will 55 * expire after priv->conf.maxStaleness seconds. 56 * 57 * This node is optimzed for stable networks, where machines jump 58 * from one port to the other only rarely. 59 */ 60 61 #include <sys/param.h> 62 #include <sys/systm.h> 63 #include <sys/kernel.h> 64 #include <sys/malloc.h> 65 #include <sys/mbuf.h> 66 #include <sys/errno.h> 67 #include <sys/syslog.h> 68 #include <sys/socket.h> 69 #include <sys/ctype.h> 70 #include <sys/thread2.h> 71 72 #include <net/if.h> 73 #include <net/ethernet.h> 74 75 #include <netinet/in.h> 76 #include <net/ipfw/ip_fw.h> 77 78 #include <netgraph/ng_message.h> 79 #include <netgraph/netgraph.h> 80 #include <netgraph/ng_parse.h> 81 #include "ng_bridge.h" 82 #include <netgraph/ether/ng_ether.h> 83 84 /* Per-link private data */ 85 struct ng_bridge_link { 86 hook_p hook; /* netgraph hook */ 87 u_int16_t loopCount; /* loop ignore timer */ 88 struct ng_bridge_link_stats stats; /* link stats */ 89 }; 90 91 /* Per-node private data */ 92 struct ng_bridge_private { 93 struct ng_bridge_bucket *tab; /* hash table bucket array */ 94 struct ng_bridge_link *links[NG_BRIDGE_MAX_LINKS]; 95 struct ng_bridge_config conf; /* node configuration */ 96 node_p node; /* netgraph node */ 97 u_int numHosts; /* num entries in table */ 98 u_int numBuckets; /* num buckets in table */ 99 u_int hashMask; /* numBuckets - 1 */ 100 int numLinks; /* num connected links */ 101 struct callout timer; /* one second periodic timer */ 102 }; 103 typedef struct ng_bridge_private *priv_p; 104 105 /* Information about a host, stored in a hash table entry */ 106 struct ng_bridge_hent { 107 struct ng_bridge_host host; /* actual host info */ 108 SLIST_ENTRY(ng_bridge_hent) next; /* next entry in bucket */ 109 }; 110 111 /* Hash table bucket declaration */ 112 SLIST_HEAD(ng_bridge_bucket, ng_bridge_hent); 113 114 /* Netgraph node methods */ 115 static ng_constructor_t ng_bridge_constructor; 116 static ng_rcvmsg_t ng_bridge_rcvmsg; 117 static ng_shutdown_t ng_bridge_rmnode; 118 static ng_newhook_t ng_bridge_newhook; 119 static ng_rcvdata_t ng_bridge_rcvdata; 120 static ng_disconnect_t ng_bridge_disconnect; 121 122 /* Other internal functions */ 123 static struct ng_bridge_host *ng_bridge_get(priv_p priv, const u_char *addr); 124 static int ng_bridge_put(priv_p priv, const u_char *addr, int linkNum); 125 static void ng_bridge_rehash(priv_p priv); 126 static void ng_bridge_remove_hosts(priv_p priv, int linkNum); 127 static void ng_bridge_timeout(void *arg); 128 static const char *ng_bridge_nodename(node_p node); 129 130 /* Ethernet broadcast */ 131 static const u_char ng_bridge_bcast_addr[ETHER_ADDR_LEN] = 132 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; 133 134 /* Store each hook's link number in the private field */ 135 #define LINK_NUM(hook) (*(u_int16_t *)(&(hook)->private)) 136 137 /* Compare Ethernet addresses using 32 and 16 bit words instead of bytewise */ 138 #define ETHER_EQUAL(a,b) (((const u_int32_t *)(a))[0] \ 139 == ((const u_int32_t *)(b))[0] \ 140 && ((const u_int16_t *)(a))[2] \ 141 == ((const u_int16_t *)(b))[2]) 142 143 /* Minimum and maximum number of hash buckets. Must be a power of two. */ 144 #define MIN_BUCKETS (1 << 5) /* 32 */ 145 #define MAX_BUCKETS (1 << 14) /* 16384 */ 146 147 /* Configuration default values */ 148 #define DEFAULT_LOOP_TIMEOUT 60 149 #define DEFAULT_MAX_STALENESS (15 * 60) /* same as ARP timeout */ 150 #define DEFAULT_MIN_STABLE_AGE 1 151 152 /****************************************************************** 153 NETGRAPH PARSE TYPES 154 ******************************************************************/ 155 156 /* 157 * How to determine the length of the table returned by NGM_BRIDGE_GET_TABLE 158 */ 159 static int 160 ng_bridge_getTableLength(const struct ng_parse_type *type, 161 const u_char *start, const u_char *buf) 162 { 163 const struct ng_bridge_host_ary *const hary 164 = (const struct ng_bridge_host_ary *)(buf - sizeof(u_int32_t)); 165 166 return hary->numHosts; 167 } 168 169 /* Parse type for struct ng_bridge_host_ary */ 170 static const struct ng_parse_struct_field ng_bridge_host_type_fields[] 171 = NG_BRIDGE_HOST_TYPE_INFO(&ng_ether_enaddr_type); 172 static const struct ng_parse_type ng_bridge_host_type = { 173 &ng_parse_struct_type, 174 &ng_bridge_host_type_fields 175 }; 176 static const struct ng_parse_array_info ng_bridge_hary_type_info = { 177 &ng_bridge_host_type, 178 ng_bridge_getTableLength 179 }; 180 static const struct ng_parse_type ng_bridge_hary_type = { 181 &ng_parse_array_type, 182 &ng_bridge_hary_type_info 183 }; 184 static const struct ng_parse_struct_field ng_bridge_host_ary_type_fields[] 185 = NG_BRIDGE_HOST_ARY_TYPE_INFO(&ng_bridge_hary_type); 186 static const struct ng_parse_type ng_bridge_host_ary_type = { 187 &ng_parse_struct_type, 188 &ng_bridge_host_ary_type_fields 189 }; 190 191 /* Parse type for struct ng_bridge_config */ 192 static const struct ng_parse_fixedarray_info ng_bridge_ipfwary_type_info = { 193 &ng_parse_uint8_type, 194 NG_BRIDGE_MAX_LINKS 195 }; 196 static const struct ng_parse_type ng_bridge_ipfwary_type = { 197 &ng_parse_fixedarray_type, 198 &ng_bridge_ipfwary_type_info 199 }; 200 static const struct ng_parse_struct_field ng_bridge_config_type_fields[] 201 = NG_BRIDGE_CONFIG_TYPE_INFO(&ng_bridge_ipfwary_type); 202 static const struct ng_parse_type ng_bridge_config_type = { 203 &ng_parse_struct_type, 204 &ng_bridge_config_type_fields 205 }; 206 207 /* Parse type for struct ng_bridge_link_stat */ 208 static const struct ng_parse_struct_field ng_bridge_stats_type_fields[] 209 = NG_BRIDGE_STATS_TYPE_INFO; 210 static const struct ng_parse_type ng_bridge_stats_type = { 211 &ng_parse_struct_type, 212 &ng_bridge_stats_type_fields 213 }; 214 215 /* List of commands and how to convert arguments to/from ASCII */ 216 static const struct ng_cmdlist ng_bridge_cmdlist[] = { 217 { 218 NGM_BRIDGE_COOKIE, 219 NGM_BRIDGE_SET_CONFIG, 220 "setconfig", 221 &ng_bridge_config_type, 222 NULL 223 }, 224 { 225 NGM_BRIDGE_COOKIE, 226 NGM_BRIDGE_GET_CONFIG, 227 "getconfig", 228 NULL, 229 &ng_bridge_config_type 230 }, 231 { 232 NGM_BRIDGE_COOKIE, 233 NGM_BRIDGE_RESET, 234 "reset", 235 NULL, 236 NULL 237 }, 238 { 239 NGM_BRIDGE_COOKIE, 240 NGM_BRIDGE_GET_STATS, 241 "getstats", 242 &ng_parse_uint32_type, 243 &ng_bridge_stats_type 244 }, 245 { 246 NGM_BRIDGE_COOKIE, 247 NGM_BRIDGE_CLR_STATS, 248 "clrstats", 249 &ng_parse_uint32_type, 250 NULL 251 }, 252 { 253 NGM_BRIDGE_COOKIE, 254 NGM_BRIDGE_GETCLR_STATS, 255 "getclrstats", 256 &ng_parse_uint32_type, 257 &ng_bridge_stats_type 258 }, 259 { 260 NGM_BRIDGE_COOKIE, 261 NGM_BRIDGE_GET_TABLE, 262 "gettable", 263 NULL, 264 &ng_bridge_host_ary_type 265 }, 266 { 0 } 267 }; 268 269 /* Node type descriptor */ 270 static struct ng_type ng_bridge_typestruct = { 271 NG_VERSION, 272 NG_BRIDGE_NODE_TYPE, 273 NULL, 274 ng_bridge_constructor, 275 ng_bridge_rcvmsg, 276 ng_bridge_rmnode, 277 ng_bridge_newhook, 278 NULL, 279 NULL, 280 ng_bridge_rcvdata, 281 ng_bridge_rcvdata, 282 ng_bridge_disconnect, 283 ng_bridge_cmdlist, 284 }; 285 NETGRAPH_INIT(bridge, &ng_bridge_typestruct); 286 287 /* Depend on ng_ether so we can use the Ethernet parse type */ 288 MODULE_DEPEND(ng_bridge, ng_ether, NG_ABI_VERSION, NG_ABI_VERSION, NG_ABI_VERSION); 289 290 /****************************************************************** 291 NETGRAPH NODE METHODS 292 ******************************************************************/ 293 294 /* 295 * Node constructor 296 */ 297 static int 298 ng_bridge_constructor(node_p *nodep) 299 { 300 priv_p priv; 301 int error; 302 303 /* Allocate and initialize private info */ 304 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO); 305 if (priv == NULL) 306 return (ENOMEM); 307 callout_init(&priv->timer); 308 309 /* Allocate and initialize hash table, etc. */ 310 MALLOC(priv->tab, struct ng_bridge_bucket *, 311 MIN_BUCKETS * sizeof(*priv->tab), M_NETGRAPH, M_NOWAIT | M_ZERO); 312 if (priv->tab == NULL) { 313 FREE(priv, M_NETGRAPH); 314 return (ENOMEM); 315 } 316 priv->numBuckets = MIN_BUCKETS; 317 priv->hashMask = MIN_BUCKETS - 1; 318 priv->conf.debugLevel = 1; 319 priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT; 320 priv->conf.maxStaleness = DEFAULT_MAX_STALENESS; 321 priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE; 322 323 /* Call superclass constructor */ 324 if ((error = ng_make_node_common(&ng_bridge_typestruct, nodep))) { 325 FREE(priv, M_NETGRAPH); 326 return (error); 327 } 328 (*nodep)->private = priv; 329 priv->node = *nodep; 330 331 /* Start timer; timer is always running while node is alive */ 332 callout_reset(&priv->timer, hz, ng_bridge_timeout, priv->node); 333 334 /* Done */ 335 return (0); 336 } 337 338 /* 339 * Method for attaching a new hook 340 */ 341 static int 342 ng_bridge_newhook(node_p node, hook_p hook, const char *name) 343 { 344 const priv_p priv = node->private; 345 346 /* Check for a link hook */ 347 if (strncmp(name, NG_BRIDGE_HOOK_LINK_PREFIX, 348 strlen(NG_BRIDGE_HOOK_LINK_PREFIX)) == 0) { 349 const char *cp; 350 char *eptr; 351 u_long linkNum; 352 353 cp = name + strlen(NG_BRIDGE_HOOK_LINK_PREFIX); 354 if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0')) 355 return (EINVAL); 356 linkNum = strtoul(cp, &eptr, 10); 357 if (*eptr != '\0' || linkNum >= NG_BRIDGE_MAX_LINKS) 358 return (EINVAL); 359 if (priv->links[linkNum] != NULL) 360 return (EISCONN); 361 MALLOC(priv->links[linkNum], struct ng_bridge_link *, 362 sizeof(*priv->links[linkNum]), M_NETGRAPH, M_NOWAIT); 363 if (priv->links[linkNum] == NULL) 364 return (ENOMEM); 365 bzero(priv->links[linkNum], sizeof(*priv->links[linkNum])); 366 priv->links[linkNum]->hook = hook; 367 LINK_NUM(hook) = linkNum; 368 priv->numLinks++; 369 return (0); 370 } 371 372 /* Unknown hook name */ 373 return (EINVAL); 374 } 375 376 /* 377 * Receive a control message 378 */ 379 static int 380 ng_bridge_rcvmsg(node_p node, struct ng_mesg *msg, 381 const char *retaddr, struct ng_mesg **rptr) 382 { 383 const priv_p priv = node->private; 384 struct ng_mesg *resp = NULL; 385 int error = 0; 386 387 switch (msg->header.typecookie) { 388 case NGM_BRIDGE_COOKIE: 389 switch (msg->header.cmd) { 390 case NGM_BRIDGE_GET_CONFIG: 391 { 392 struct ng_bridge_config *conf; 393 394 NG_MKRESPONSE(resp, msg, 395 sizeof(struct ng_bridge_config), M_NOWAIT); 396 if (resp == NULL) { 397 error = ENOMEM; 398 break; 399 } 400 conf = (struct ng_bridge_config *)resp->data; 401 *conf = priv->conf; /* no sanity checking needed */ 402 break; 403 } 404 case NGM_BRIDGE_SET_CONFIG: 405 { 406 struct ng_bridge_config *conf; 407 int i; 408 409 if (msg->header.arglen 410 != sizeof(struct ng_bridge_config)) { 411 error = EINVAL; 412 break; 413 } 414 conf = (struct ng_bridge_config *)msg->data; 415 priv->conf = *conf; 416 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) 417 priv->conf.ipfw[i] = !!priv->conf.ipfw[i]; 418 break; 419 } 420 case NGM_BRIDGE_RESET: 421 { 422 int i; 423 424 /* Flush all entries in the hash table */ 425 ng_bridge_remove_hosts(priv, -1); 426 427 /* Reset all loop detection counters and stats */ 428 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) { 429 if (priv->links[i] == NULL) 430 continue; 431 priv->links[i]->loopCount = 0; 432 bzero(&priv->links[i]->stats, 433 sizeof(priv->links[i]->stats)); 434 } 435 break; 436 } 437 case NGM_BRIDGE_GET_STATS: 438 case NGM_BRIDGE_CLR_STATS: 439 case NGM_BRIDGE_GETCLR_STATS: 440 { 441 struct ng_bridge_link *link; 442 int linkNum; 443 444 /* Get link number */ 445 if (msg->header.arglen != sizeof(u_int32_t)) { 446 error = EINVAL; 447 break; 448 } 449 linkNum = *((u_int32_t *)msg->data); 450 if (linkNum < 0 || linkNum >= NG_BRIDGE_MAX_LINKS) { 451 error = EINVAL; 452 break; 453 } 454 if ((link = priv->links[linkNum]) == NULL) { 455 error = ENOTCONN; 456 break; 457 } 458 459 /* Get/clear stats */ 460 if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) { 461 NG_MKRESPONSE(resp, msg, 462 sizeof(link->stats), M_NOWAIT); 463 if (resp == NULL) { 464 error = ENOMEM; 465 break; 466 } 467 bcopy(&link->stats, 468 resp->data, sizeof(link->stats)); 469 } 470 if (msg->header.cmd != NGM_BRIDGE_GET_STATS) 471 bzero(&link->stats, sizeof(link->stats)); 472 break; 473 } 474 case NGM_BRIDGE_GET_TABLE: 475 { 476 struct ng_bridge_host_ary *ary; 477 struct ng_bridge_hent *hent; 478 int i = 0, bucket; 479 480 NG_MKRESPONSE(resp, msg, sizeof(*ary) 481 + (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT); 482 if (resp == NULL) { 483 error = ENOMEM; 484 break; 485 } 486 ary = (struct ng_bridge_host_ary *)resp->data; 487 ary->numHosts = priv->numHosts; 488 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 489 SLIST_FOREACH(hent, &priv->tab[bucket], next) 490 ary->hosts[i++] = hent->host; 491 } 492 break; 493 } 494 default: 495 error = EINVAL; 496 break; 497 } 498 break; 499 default: 500 error = EINVAL; 501 break; 502 } 503 504 /* Done */ 505 if (rptr) 506 *rptr = resp; 507 else if (resp != NULL) 508 FREE(resp, M_NETGRAPH); 509 FREE(msg, M_NETGRAPH); 510 return (error); 511 } 512 513 /* 514 * Receive data on a hook 515 */ 516 static int 517 ng_bridge_rcvdata(hook_p hook, struct mbuf *m, meta_p meta) 518 { 519 const node_p node = hook->node; 520 const priv_p priv = node->private; 521 struct ng_bridge_host *host; 522 struct ng_bridge_link *link; 523 struct ether_header *eh; 524 int error = 0, linkNum; 525 int i, manycast; 526 527 /* Get link number */ 528 linkNum = LINK_NUM(hook); 529 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 530 ("%s: linkNum=%u", __func__, linkNum)); 531 link = priv->links[linkNum]; 532 KASSERT(link != NULL, ("%s: link%d null", __func__, 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_DATA(m, meta); 538 return (EINVAL); 539 } 540 if (m->m_len < ETHER_HDR_LEN && !(m = m_pullup(m, ETHER_HDR_LEN))) { 541 link->stats.memoryFailures++; 542 NG_FREE_META(meta); 543 return (ENOBUFS); 544 } 545 eh = mtod(m, struct ether_header *); 546 if ((eh->ether_shost[0] & 1) != 0) { 547 link->stats.recvInvalid++; 548 NG_FREE_DATA(m, meta); 549 return (EINVAL); 550 } 551 552 /* Is link disabled due to a loopback condition? */ 553 if (link->loopCount != 0) { 554 link->stats.loopDrops++; 555 NG_FREE_DATA(m, meta); 556 return (ELOOP); /* XXX is this an appropriate error? */ 557 } 558 559 /* Update stats */ 560 link->stats.recvPackets++; 561 link->stats.recvOctets += m->m_pkthdr.len; 562 if ((manycast = (eh->ether_dhost[0] & 1)) != 0) { 563 if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) { 564 link->stats.recvBroadcasts++; 565 manycast = 2; 566 } else 567 link->stats.recvMulticasts++; 568 } 569 570 /* Look up packet's source Ethernet address in hashtable */ 571 if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) { 572 573 /* Update time since last heard from this host */ 574 host->staleness = 0; 575 576 /* Did host jump to a different link? */ 577 if (host->linkNum != linkNum) { 578 579 /* 580 * If the host's old link was recently established 581 * on the old link and it's already jumped to a new 582 * link, declare a loopback condition. 583 */ 584 if (host->age < priv->conf.minStableAge) { 585 586 /* Log the problem */ 587 if (priv->conf.debugLevel >= 2) { 588 struct ifnet *ifp = m->m_pkthdr.rcvif; 589 char suffix[32]; 590 591 if (ifp != NULL) 592 ksnprintf(suffix, sizeof(suffix), 593 " (%s)", ifp->if_xname); 594 else 595 *suffix = '\0'; 596 log(LOG_WARNING, "ng_bridge: %s:" 597 " loopback detected on %s%s\n", 598 ng_bridge_nodename(node), 599 hook->name, suffix); 600 } 601 602 /* Mark link as linka non grata */ 603 link->loopCount = priv->conf.loopTimeout; 604 link->stats.loopDetects++; 605 606 /* Forget all hosts on this link */ 607 ng_bridge_remove_hosts(priv, linkNum); 608 609 /* Drop packet */ 610 link->stats.loopDrops++; 611 NG_FREE_DATA(m, meta); 612 return (ELOOP); /* XXX appropriate? */ 613 } 614 615 /* Move host over to new link */ 616 host->linkNum = linkNum; 617 host->age = 0; 618 } 619 } else { 620 if (!ng_bridge_put(priv, eh->ether_shost, linkNum)) { 621 link->stats.memoryFailures++; 622 NG_FREE_DATA(m, meta); 623 return (ENOMEM); 624 } 625 } 626 627 /* Run packet through ipfw processing, if enabled */ 628 if (priv->conf.ipfw[linkNum] && fw_enable && ip_fw_chk_ptr != NULL) { 629 /* XXX not implemented yet */ 630 } 631 632 /* 633 * If unicast and destination host known, deliver to host's link, 634 * unless it is the same link as the packet came in on. 635 */ 636 if (!manycast) { 637 638 /* Determine packet destination link */ 639 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) { 640 struct ng_bridge_link *const destLink 641 = priv->links[host->linkNum]; 642 643 /* If destination same as incoming link, do nothing */ 644 KASSERT(destLink != NULL, 645 ("%s: link%d null", __func__, host->linkNum)); 646 if (destLink == link) { 647 NG_FREE_DATA(m, meta); 648 return (0); 649 } 650 651 /* Deliver packet out the destination link */ 652 destLink->stats.xmitPackets++; 653 destLink->stats.xmitOctets += m->m_pkthdr.len; 654 NG_SEND_DATA(error, destLink->hook, m, meta); 655 return (error); 656 } 657 658 /* Destination host is not known */ 659 link->stats.recvUnknown++; 660 } 661 662 /* Distribute unknown, multicast, broadcast pkts to all other links */ 663 for (linkNum = i = 0; i < priv->numLinks - 1; linkNum++) { 664 struct ng_bridge_link *const destLink = priv->links[linkNum]; 665 meta_p meta2 = NULL; 666 struct mbuf *m2; 667 668 /* Skip incoming link and disconnected links */ 669 if (destLink == NULL || destLink == link) 670 continue; 671 672 /* Copy mbuf and meta info */ 673 if (++i == priv->numLinks - 1) { /* last link */ 674 m2 = m; 675 meta2 = meta; 676 } else { 677 m2 = m_dup(m, M_NOWAIT); /* XXX m_copypacket() */ 678 if (m2 == NULL) { 679 link->stats.memoryFailures++; 680 NG_FREE_DATA(m, meta); 681 return (ENOBUFS); 682 } 683 if (meta != NULL 684 && (meta2 = ng_copy_meta(meta)) == NULL) { 685 link->stats.memoryFailures++; 686 m_freem(m2); 687 NG_FREE_DATA(m, meta); 688 return (ENOMEM); 689 } 690 } 691 692 /* Update stats */ 693 destLink->stats.xmitPackets++; 694 destLink->stats.xmitOctets += m->m_pkthdr.len; 695 switch (manycast) { 696 case 0: /* unicast */ 697 break; 698 case 1: /* multicast */ 699 destLink->stats.xmitMulticasts++; 700 break; 701 case 2: /* broadcast */ 702 destLink->stats.xmitBroadcasts++; 703 break; 704 } 705 706 /* Send packet */ 707 NG_SEND_DATA(error, destLink->hook, m2, meta2); 708 } 709 return (error); 710 } 711 712 /* 713 * Shutdown node 714 */ 715 static int 716 ng_bridge_rmnode(node_p node) 717 { 718 const priv_p priv = node->private; 719 720 /* 721 * Shut down everything except the timer. There's no way to 722 * avoid another possible timeout event (it may have already 723 * been dequeued), so we can't free the node yet. 724 */ 725 ng_unname(node); 726 ng_cutlinks(node); /* frees all link and host info */ 727 KASSERT(priv->numLinks == 0 && priv->numHosts == 0, 728 ("%s: numLinks=%d numHosts=%d", 729 __func__, priv->numLinks, priv->numHosts)); 730 FREE(priv->tab, M_NETGRAPH); 731 732 /* NG_INVALID flag is now set so node will be freed at next timeout */ 733 return (0); 734 } 735 736 /* 737 * Hook disconnection. 738 */ 739 static int 740 ng_bridge_disconnect(hook_p hook) 741 { 742 const priv_p priv = hook->node->private; 743 int linkNum; 744 745 /* Get link number */ 746 linkNum = LINK_NUM(hook); 747 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 748 ("%s: linkNum=%u", __func__, linkNum)); 749 750 /* Remove all hosts associated with this link */ 751 ng_bridge_remove_hosts(priv, linkNum); 752 753 /* Free associated link information */ 754 KASSERT(priv->links[linkNum] != NULL, ("%s: no link", __func__)); 755 FREE(priv->links[linkNum], M_NETGRAPH); 756 priv->links[linkNum] = NULL; 757 priv->numLinks--; 758 759 /* If no more hooks, go away */ 760 if (hook->node->numhooks == 0) 761 ng_rmnode(hook->node); 762 return (0); 763 } 764 765 /****************************************************************** 766 HASH TABLE FUNCTIONS 767 ******************************************************************/ 768 769 /* 770 * Hash algorithm 771 * 772 * Only hashing bytes 3-6 of the Ethernet address is sufficient and fast. 773 */ 774 #define HASH(addr,mask) ( (((const u_int16_t *)(addr))[0] \ 775 ^ ((const u_int16_t *)(addr))[1] \ 776 ^ ((const u_int16_t *)(addr))[2]) & (mask) ) 777 778 /* 779 * Find a host entry in the table. 780 */ 781 static struct ng_bridge_host * 782 ng_bridge_get(priv_p priv, const u_char *addr) 783 { 784 const int bucket = HASH(addr, priv->hashMask); 785 struct ng_bridge_hent *hent; 786 787 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 788 if (ETHER_EQUAL(hent->host.addr, addr)) 789 return (&hent->host); 790 } 791 return (NULL); 792 } 793 794 /* 795 * Add a new host entry to the table. This assumes the host doesn't 796 * already exist in the table. Returns 1 on success, 0 if there 797 * was a memory allocation failure. 798 */ 799 static int 800 ng_bridge_put(priv_p priv, const u_char *addr, int linkNum) 801 { 802 const int bucket = HASH(addr, priv->hashMask); 803 struct ng_bridge_hent *hent; 804 805 #ifdef INVARIANTS 806 /* Assert that entry does not already exist in hashtable */ 807 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 808 KASSERT(!ETHER_EQUAL(hent->host.addr, addr), 809 ("%s: entry %6D exists in table", __func__, addr, ":")); 810 } 811 #endif 812 813 /* Allocate and initialize new hashtable entry */ 814 MALLOC(hent, struct ng_bridge_hent *, 815 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 MALLOC(newTab, struct ng_bridge_bucket *, 860 newNumBuckets * sizeof(*newTab), M_NETGRAPH, 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 FREE(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 FREE(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; 936 937 /* If node was shut down, this is the final lingering timeout */ 938 crit_enter(); 939 if ((node->flags & NG_INVALID) != 0) { 940 FREE(priv, M_NETGRAPH); 941 node->private = NULL; 942 ng_unref(node); 943 crit_exit(); 944 return; 945 } 946 947 /* Register a new timeout, keeping the existing node reference */ 948 callout_reset(&priv->timer, hz, ng_bridge_timeout, node); 949 950 /* Update host time counters and remove stale entries */ 951 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 952 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 953 954 while (*hptr != NULL) { 955 struct ng_bridge_hent *const hent = *hptr; 956 957 /* Make sure host's link really exists */ 958 KASSERT(priv->links[hent->host.linkNum] != NULL, 959 ("%s: host %6D on nonexistent link %d\n", 960 __func__, hent->host.addr, ":", 961 hent->host.linkNum)); 962 963 /* Remove hosts we haven't heard from in a while */ 964 if (++hent->host.staleness >= priv->conf.maxStaleness) { 965 *hptr = SLIST_NEXT(hent, next); 966 FREE(hent, M_NETGRAPH); 967 priv->numHosts--; 968 } else { 969 if (hent->host.age < 0xffff) 970 hent->host.age++; 971 hptr = &SLIST_NEXT(hent, next); 972 counter++; 973 } 974 } 975 } 976 KASSERT(priv->numHosts == counter, 977 ("%s: hosts: %d != %d", __func__, priv->numHosts, counter)); 978 979 /* Decrease table size if necessary */ 980 ng_bridge_rehash(priv); 981 982 /* Decrease loop counter on muted looped back links */ 983 for (counter = linkNum = 0; linkNum < NG_BRIDGE_MAX_LINKS; linkNum++) { 984 struct ng_bridge_link *const link = priv->links[linkNum]; 985 986 if (link != NULL) { 987 if (link->loopCount != 0) { 988 link->loopCount--; 989 if (link->loopCount == 0 990 && priv->conf.debugLevel >= 2) { 991 log(LOG_INFO, "ng_bridge: %s:" 992 " restoring looped back link%d\n", 993 ng_bridge_nodename(node), linkNum); 994 } 995 } 996 counter++; 997 } 998 } 999 KASSERT(priv->numLinks == counter, 1000 ("%s: links: %d != %d", __func__, priv->numLinks, counter)); 1001 1002 /* Done */ 1003 crit_exit(); 1004 } 1005 1006 /* 1007 * Return node's "name", even if it doesn't have one. 1008 */ 1009 static const char * 1010 ng_bridge_nodename(node_p node) 1011 { 1012 static char name[NG_NODESIZ]; 1013 1014 if (node->name != NULL) 1015 ksnprintf(name, sizeof(name), "%s", node->name); 1016 else 1017 ksnprintf(name, sizeof(name), "[%x]", ng_node2ID(node)); 1018 return name; 1019 } 1020 1021