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 1.6 2004/01/06 03:17:27 dillon 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 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, 1, 1, 1); 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 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT); 304 if (priv == NULL) 305 return (ENOMEM); 306 bzero(priv, sizeof(*priv)); 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); 312 if (priv->tab == NULL) { 313 FREE(priv, M_NETGRAPH); 314 return (ENOMEM); 315 } 316 bzero(priv->tab, MIN_BUCKETS * sizeof(*priv->tab)); /* init SLIST's */ 317 priv->numBuckets = MIN_BUCKETS; 318 priv->hashMask = MIN_BUCKETS - 1; 319 priv->conf.debugLevel = 1; 320 priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT; 321 priv->conf.maxStaleness = DEFAULT_MAX_STALENESS; 322 priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE; 323 324 /* Call superclass constructor */ 325 if ((error = ng_make_node_common(&ng_bridge_typestruct, nodep))) { 326 FREE(priv, M_NETGRAPH); 327 return (error); 328 } 329 (*nodep)->private = priv; 330 priv->node = *nodep; 331 332 /* Start timer; timer is always running while node is alive */ 333 callout_reset(&priv->timer, hz, ng_bridge_timeout, priv->node); 334 335 /* Done */ 336 return (0); 337 } 338 339 /* 340 * Method for attaching a new hook 341 */ 342 static int 343 ng_bridge_newhook(node_p node, hook_p hook, const char *name) 344 { 345 const priv_p priv = node->private; 346 347 /* Check for a link hook */ 348 if (strncmp(name, NG_BRIDGE_HOOK_LINK_PREFIX, 349 strlen(NG_BRIDGE_HOOK_LINK_PREFIX)) == 0) { 350 const char *cp; 351 char *eptr; 352 u_long linkNum; 353 354 cp = name + strlen(NG_BRIDGE_HOOK_LINK_PREFIX); 355 if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0')) 356 return (EINVAL); 357 linkNum = strtoul(cp, &eptr, 10); 358 if (*eptr != '\0' || linkNum >= NG_BRIDGE_MAX_LINKS) 359 return (EINVAL); 360 if (priv->links[linkNum] != NULL) 361 return (EISCONN); 362 MALLOC(priv->links[linkNum], struct ng_bridge_link *, 363 sizeof(*priv->links[linkNum]), M_NETGRAPH, M_NOWAIT); 364 if (priv->links[linkNum] == NULL) 365 return (ENOMEM); 366 bzero(priv->links[linkNum], sizeof(*priv->links[linkNum])); 367 priv->links[linkNum]->hook = hook; 368 LINK_NUM(hook) = linkNum; 369 priv->numLinks++; 370 return (0); 371 } 372 373 /* Unknown hook name */ 374 return (EINVAL); 375 } 376 377 /* 378 * Receive a control message 379 */ 380 static int 381 ng_bridge_rcvmsg(node_p node, struct ng_mesg *msg, 382 const char *retaddr, struct ng_mesg **rptr) 383 { 384 const priv_p priv = node->private; 385 struct ng_mesg *resp = NULL; 386 int error = 0; 387 388 switch (msg->header.typecookie) { 389 case NGM_BRIDGE_COOKIE: 390 switch (msg->header.cmd) { 391 case NGM_BRIDGE_GET_CONFIG: 392 { 393 struct ng_bridge_config *conf; 394 395 NG_MKRESPONSE(resp, msg, 396 sizeof(struct ng_bridge_config), M_NOWAIT); 397 if (resp == NULL) { 398 error = ENOMEM; 399 break; 400 } 401 conf = (struct ng_bridge_config *)resp->data; 402 *conf = priv->conf; /* no sanity checking needed */ 403 break; 404 } 405 case NGM_BRIDGE_SET_CONFIG: 406 { 407 struct ng_bridge_config *conf; 408 int i; 409 410 if (msg->header.arglen 411 != sizeof(struct ng_bridge_config)) { 412 error = EINVAL; 413 break; 414 } 415 conf = (struct ng_bridge_config *)msg->data; 416 priv->conf = *conf; 417 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) 418 priv->conf.ipfw[i] = !!priv->conf.ipfw[i]; 419 break; 420 } 421 case NGM_BRIDGE_RESET: 422 { 423 int i; 424 425 /* Flush all entries in the hash table */ 426 ng_bridge_remove_hosts(priv, -1); 427 428 /* Reset all loop detection counters and stats */ 429 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) { 430 if (priv->links[i] == NULL) 431 continue; 432 priv->links[i]->loopCount = 0; 433 bzero(&priv->links[i]->stats, 434 sizeof(priv->links[i]->stats)); 435 } 436 break; 437 } 438 case NGM_BRIDGE_GET_STATS: 439 case NGM_BRIDGE_CLR_STATS: 440 case NGM_BRIDGE_GETCLR_STATS: 441 { 442 struct ng_bridge_link *link; 443 int linkNum; 444 445 /* Get link number */ 446 if (msg->header.arglen != sizeof(u_int32_t)) { 447 error = EINVAL; 448 break; 449 } 450 linkNum = *((u_int32_t *)msg->data); 451 if (linkNum < 0 || linkNum >= NG_BRIDGE_MAX_LINKS) { 452 error = EINVAL; 453 break; 454 } 455 if ((link = priv->links[linkNum]) == NULL) { 456 error = ENOTCONN; 457 break; 458 } 459 460 /* Get/clear stats */ 461 if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) { 462 NG_MKRESPONSE(resp, msg, 463 sizeof(link->stats), M_NOWAIT); 464 if (resp == NULL) { 465 error = ENOMEM; 466 break; 467 } 468 bcopy(&link->stats, 469 resp->data, sizeof(link->stats)); 470 } 471 if (msg->header.cmd != NGM_BRIDGE_GET_STATS) 472 bzero(&link->stats, sizeof(link->stats)); 473 break; 474 } 475 case NGM_BRIDGE_GET_TABLE: 476 { 477 struct ng_bridge_host_ary *ary; 478 struct ng_bridge_hent *hent; 479 int i = 0, bucket; 480 481 NG_MKRESPONSE(resp, msg, sizeof(*ary) 482 + (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT); 483 if (resp == NULL) { 484 error = ENOMEM; 485 break; 486 } 487 ary = (struct ng_bridge_host_ary *)resp->data; 488 ary->numHosts = priv->numHosts; 489 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 490 SLIST_FOREACH(hent, &priv->tab[bucket], next) 491 ary->hosts[i++] = hent->host; 492 } 493 break; 494 } 495 default: 496 error = EINVAL; 497 break; 498 } 499 break; 500 default: 501 error = EINVAL; 502 break; 503 } 504 505 /* Done */ 506 if (rptr) 507 *rptr = resp; 508 else if (resp != NULL) 509 FREE(resp, M_NETGRAPH); 510 FREE(msg, M_NETGRAPH); 511 return (error); 512 } 513 514 /* 515 * Receive data on a hook 516 */ 517 static int 518 ng_bridge_rcvdata(hook_p hook, struct mbuf *m, meta_p meta) 519 { 520 const node_p node = hook->node; 521 const priv_p priv = node->private; 522 struct ng_bridge_host *host; 523 struct ng_bridge_link *link; 524 struct ether_header *eh; 525 int error = 0, linkNum; 526 int i, manycast; 527 528 /* Get link number */ 529 linkNum = LINK_NUM(hook); 530 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 531 ("%s: linkNum=%u", __FUNCTION__, linkNum)); 532 link = priv->links[linkNum]; 533 KASSERT(link != NULL, ("%s: link%d null", __FUNCTION__, linkNum)); 534 535 /* Sanity check packet and pull up header */ 536 if (m->m_pkthdr.len < ETHER_HDR_LEN) { 537 link->stats.recvRunts++; 538 NG_FREE_DATA(m, meta); 539 return (EINVAL); 540 } 541 if (m->m_len < ETHER_HDR_LEN && !(m = m_pullup(m, ETHER_HDR_LEN))) { 542 link->stats.memoryFailures++; 543 NG_FREE_META(meta); 544 return (ENOBUFS); 545 } 546 eh = mtod(m, struct ether_header *); 547 if ((eh->ether_shost[0] & 1) != 0) { 548 link->stats.recvInvalid++; 549 NG_FREE_DATA(m, meta); 550 return (EINVAL); 551 } 552 553 /* Is link disabled due to a loopback condition? */ 554 if (link->loopCount != 0) { 555 link->stats.loopDrops++; 556 NG_FREE_DATA(m, meta); 557 return (ELOOP); /* XXX is this an appropriate error? */ 558 } 559 560 /* Update stats */ 561 link->stats.recvPackets++; 562 link->stats.recvOctets += m->m_pkthdr.len; 563 if ((manycast = (eh->ether_dhost[0] & 1)) != 0) { 564 if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) { 565 link->stats.recvBroadcasts++; 566 manycast = 2; 567 } else 568 link->stats.recvMulticasts++; 569 } 570 571 /* Look up packet's source Ethernet address in hashtable */ 572 if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) { 573 574 /* Update time since last heard from this host */ 575 host->staleness = 0; 576 577 /* Did host jump to a different link? */ 578 if (host->linkNum != linkNum) { 579 580 /* 581 * If the host's old link was recently established 582 * on the old link and it's already jumped to a new 583 * link, declare a loopback condition. 584 */ 585 if (host->age < priv->conf.minStableAge) { 586 587 /* Log the problem */ 588 if (priv->conf.debugLevel >= 2) { 589 struct ifnet *ifp = m->m_pkthdr.rcvif; 590 char suffix[32]; 591 592 if (ifp != NULL) 593 snprintf(suffix, sizeof(suffix), 594 " (%s)", ifp->if_xname); 595 else 596 *suffix = '\0'; 597 log(LOG_WARNING, "ng_bridge: %s:" 598 " loopback detected on %s%s\n", 599 ng_bridge_nodename(node), 600 hook->name, suffix); 601 } 602 603 /* Mark link as linka non grata */ 604 link->loopCount = priv->conf.loopTimeout; 605 link->stats.loopDetects++; 606 607 /* Forget all hosts on this link */ 608 ng_bridge_remove_hosts(priv, linkNum); 609 610 /* Drop packet */ 611 link->stats.loopDrops++; 612 NG_FREE_DATA(m, meta); 613 return (ELOOP); /* XXX appropriate? */ 614 } 615 616 /* Move host over to new link */ 617 host->linkNum = linkNum; 618 host->age = 0; 619 } 620 } else { 621 if (!ng_bridge_put(priv, eh->ether_shost, linkNum)) { 622 link->stats.memoryFailures++; 623 NG_FREE_DATA(m, meta); 624 return (ENOMEM); 625 } 626 } 627 628 /* Run packet through ipfw processing, if enabled */ 629 if (priv->conf.ipfw[linkNum] && fw_enable && ip_fw_chk_ptr != NULL) { 630 /* XXX not implemented yet */ 631 } 632 633 /* 634 * If unicast and destination host known, deliver to host's link, 635 * unless it is the same link as the packet came in on. 636 */ 637 if (!manycast) { 638 639 /* Determine packet destination link */ 640 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) { 641 struct ng_bridge_link *const destLink 642 = priv->links[host->linkNum]; 643 644 /* If destination same as incoming link, do nothing */ 645 KASSERT(destLink != NULL, 646 ("%s: link%d null", __FUNCTION__, host->linkNum)); 647 if (destLink == link) { 648 NG_FREE_DATA(m, meta); 649 return (0); 650 } 651 652 /* Deliver packet out the destination link */ 653 destLink->stats.xmitPackets++; 654 destLink->stats.xmitOctets += m->m_pkthdr.len; 655 NG_SEND_DATA(error, destLink->hook, m, meta); 656 return (error); 657 } 658 659 /* Destination host is not known */ 660 link->stats.recvUnknown++; 661 } 662 663 /* Distribute unknown, multicast, broadcast pkts to all other links */ 664 for (linkNum = i = 0; i < priv->numLinks - 1; linkNum++) { 665 struct ng_bridge_link *const destLink = priv->links[linkNum]; 666 meta_p meta2 = NULL; 667 struct mbuf *m2; 668 669 /* Skip incoming link and disconnected links */ 670 if (destLink == NULL || destLink == link) 671 continue; 672 673 /* Copy mbuf and meta info */ 674 if (++i == priv->numLinks - 1) { /* last link */ 675 m2 = m; 676 meta2 = meta; 677 } else { 678 m2 = m_dup(m, M_NOWAIT); /* XXX m_copypacket() */ 679 if (m2 == NULL) { 680 link->stats.memoryFailures++; 681 NG_FREE_DATA(m, meta); 682 return (ENOBUFS); 683 } 684 if (meta != NULL 685 && (meta2 = ng_copy_meta(meta)) == NULL) { 686 link->stats.memoryFailures++; 687 m_freem(m2); 688 NG_FREE_DATA(m, meta); 689 return (ENOMEM); 690 } 691 } 692 693 /* Update stats */ 694 destLink->stats.xmitPackets++; 695 destLink->stats.xmitOctets += m->m_pkthdr.len; 696 switch (manycast) { 697 case 0: /* unicast */ 698 break; 699 case 1: /* multicast */ 700 destLink->stats.xmitMulticasts++; 701 break; 702 case 2: /* broadcast */ 703 destLink->stats.xmitBroadcasts++; 704 break; 705 } 706 707 /* Send packet */ 708 NG_SEND_DATA(error, destLink->hook, m2, meta2); 709 } 710 return (error); 711 } 712 713 /* 714 * Shutdown node 715 */ 716 static int 717 ng_bridge_rmnode(node_p node) 718 { 719 const priv_p priv = node->private; 720 721 /* 722 * Shut down everything except the timer. There's no way to 723 * avoid another possible timeout event (it may have already 724 * been dequeued), so we can't free the node yet. 725 */ 726 ng_unname(node); 727 ng_cutlinks(node); /* frees all link and host info */ 728 KASSERT(priv->numLinks == 0 && priv->numHosts == 0, 729 ("%s: numLinks=%d numHosts=%d", 730 __FUNCTION__, priv->numLinks, priv->numHosts)); 731 FREE(priv->tab, M_NETGRAPH); 732 733 /* NG_INVALID flag is now set so node will be freed at next timeout */ 734 return (0); 735 } 736 737 /* 738 * Hook disconnection. 739 */ 740 static int 741 ng_bridge_disconnect(hook_p hook) 742 { 743 const priv_p priv = hook->node->private; 744 int linkNum; 745 746 /* Get link number */ 747 linkNum = LINK_NUM(hook); 748 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 749 ("%s: linkNum=%u", __FUNCTION__, linkNum)); 750 751 /* Remove all hosts associated with this link */ 752 ng_bridge_remove_hosts(priv, linkNum); 753 754 /* Free associated link information */ 755 KASSERT(priv->links[linkNum] != NULL, ("%s: no link", __FUNCTION__)); 756 FREE(priv->links[linkNum], M_NETGRAPH); 757 priv->links[linkNum] = NULL; 758 priv->numLinks--; 759 760 /* If no more hooks, go away */ 761 if (hook->node->numhooks == 0) 762 ng_rmnode(hook->node); 763 return (0); 764 } 765 766 /****************************************************************** 767 HASH TABLE FUNCTIONS 768 ******************************************************************/ 769 770 /* 771 * Hash algorithm 772 * 773 * Only hashing bytes 3-6 of the Ethernet address is sufficient and fast. 774 */ 775 #define HASH(addr,mask) ( (((const u_int16_t *)(addr))[0] \ 776 ^ ((const u_int16_t *)(addr))[1] \ 777 ^ ((const u_int16_t *)(addr))[2]) & (mask) ) 778 779 /* 780 * Find a host entry in the table. 781 */ 782 static struct ng_bridge_host * 783 ng_bridge_get(priv_p priv, const u_char *addr) 784 { 785 const int bucket = HASH(addr, priv->hashMask); 786 struct ng_bridge_hent *hent; 787 788 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 789 if (ETHER_EQUAL(hent->host.addr, addr)) 790 return (&hent->host); 791 } 792 return (NULL); 793 } 794 795 /* 796 * Add a new host entry to the table. This assumes the host doesn't 797 * already exist in the table. Returns 1 on success, 0 if there 798 * was a memory allocation failure. 799 */ 800 static int 801 ng_bridge_put(priv_p priv, const u_char *addr, int linkNum) 802 { 803 const int bucket = HASH(addr, priv->hashMask); 804 struct ng_bridge_hent *hent; 805 806 #ifdef INVARIANTS 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 %6D exists in table", __FUNCTION__, addr, ":")); 811 } 812 #endif 813 814 /* Allocate and initialize new hashtable entry */ 815 MALLOC(hent, struct ng_bridge_hent *, 816 sizeof(*hent), M_NETGRAPH, M_NOWAIT); 817 if (hent == NULL) 818 return (0); 819 bcopy(addr, hent->host.addr, ETHER_ADDR_LEN); 820 hent->host.linkNum = linkNum; 821 hent->host.staleness = 0; 822 hent->host.age = 0; 823 824 /* Add new element to hash bucket */ 825 SLIST_INSERT_HEAD(&priv->tab[bucket], hent, next); 826 priv->numHosts++; 827 828 /* Resize table if necessary */ 829 ng_bridge_rehash(priv); 830 return (1); 831 } 832 833 /* 834 * Resize the hash table. We try to maintain the number of buckets 835 * such that the load factor is in the range 0.25 to 1.0. 836 * 837 * If we can't get the new memory then we silently fail. This is OK 838 * because things will still work and we'll try again soon anyway. 839 */ 840 static void 841 ng_bridge_rehash(priv_p priv) 842 { 843 struct ng_bridge_bucket *newTab; 844 int oldBucket, newBucket; 845 int newNumBuckets; 846 u_int newMask; 847 848 /* Is table too full or too empty? */ 849 if (priv->numHosts > priv->numBuckets 850 && (priv->numBuckets << 1) <= MAX_BUCKETS) 851 newNumBuckets = priv->numBuckets << 1; 852 else if (priv->numHosts < (priv->numBuckets >> 2) 853 && (priv->numBuckets >> 2) >= MIN_BUCKETS) 854 newNumBuckets = priv->numBuckets >> 2; 855 else 856 return; 857 newMask = newNumBuckets - 1; 858 859 /* Allocate and initialize new table */ 860 MALLOC(newTab, struct ng_bridge_bucket *, 861 newNumBuckets * sizeof(*newTab), M_NETGRAPH, M_NOWAIT); 862 if (newTab == NULL) 863 return; 864 bzero(newTab, newNumBuckets * sizeof(*newTab)); 865 866 /* Move all entries from old table to new table */ 867 for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) { 868 struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket]; 869 870 while (!SLIST_EMPTY(oldList)) { 871 struct ng_bridge_hent *const hent 872 = SLIST_FIRST(oldList); 873 874 SLIST_REMOVE_HEAD(oldList, next); 875 newBucket = HASH(hent->host.addr, newMask); 876 SLIST_INSERT_HEAD(&newTab[newBucket], hent, next); 877 } 878 } 879 880 /* Replace old table with new one */ 881 if (priv->conf.debugLevel >= 3) { 882 log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n", 883 ng_bridge_nodename(priv->node), 884 priv->numBuckets, newNumBuckets); 885 } 886 FREE(priv->tab, M_NETGRAPH); 887 priv->numBuckets = newNumBuckets; 888 priv->hashMask = newMask; 889 priv->tab = newTab; 890 return; 891 } 892 893 /****************************************************************** 894 MISC FUNCTIONS 895 ******************************************************************/ 896 897 /* 898 * Remove all hosts associated with a specific link from the hashtable. 899 * If linkNum == -1, then remove all hosts in the table. 900 */ 901 static void 902 ng_bridge_remove_hosts(priv_p priv, int linkNum) 903 { 904 int bucket; 905 906 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 907 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 908 909 while (*hptr != NULL) { 910 struct ng_bridge_hent *const hent = *hptr; 911 912 if (linkNum == -1 || hent->host.linkNum == linkNum) { 913 *hptr = SLIST_NEXT(hent, next); 914 FREE(hent, M_NETGRAPH); 915 priv->numHosts--; 916 } else 917 hptr = &SLIST_NEXT(hent, next); 918 } 919 } 920 } 921 922 /* 923 * Handle our once-per-second timeout event. We do two things: 924 * we decrement link->loopCount for those links being muted due to 925 * a detected loopback condition, and we remove any hosts from 926 * the hashtable whom we haven't heard from in a long while. 927 * 928 * If the node has the NG_INVALID flag set, our job is to kill it. 929 */ 930 static void 931 ng_bridge_timeout(void *arg) 932 { 933 const node_p node = arg; 934 const priv_p priv = node->private; 935 int s, bucket; 936 int counter = 0; 937 int linkNum; 938 939 /* If node was shut down, this is the final lingering timeout */ 940 s = splnet(); 941 if ((node->flags & NG_INVALID) != 0) { 942 FREE(priv, M_NETGRAPH); 943 node->private = NULL; 944 ng_unref(node); 945 splx(s); 946 return; 947 } 948 949 /* Register a new timeout, keeping the existing node reference */ 950 callout_reset(&priv->timer, hz, ng_bridge_timeout, node); 951 952 /* Update host time counters and remove stale entries */ 953 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 954 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 955 956 while (*hptr != NULL) { 957 struct ng_bridge_hent *const hent = *hptr; 958 959 /* Make sure host's link really exists */ 960 KASSERT(priv->links[hent->host.linkNum] != NULL, 961 ("%s: host %6D on nonexistent link %d\n", 962 __FUNCTION__, hent->host.addr, ":", 963 hent->host.linkNum)); 964 965 /* Remove hosts we haven't heard from in a while */ 966 if (++hent->host.staleness >= priv->conf.maxStaleness) { 967 *hptr = SLIST_NEXT(hent, next); 968 FREE(hent, M_NETGRAPH); 969 priv->numHosts--; 970 } else { 971 if (hent->host.age < 0xffff) 972 hent->host.age++; 973 hptr = &SLIST_NEXT(hent, next); 974 counter++; 975 } 976 } 977 } 978 KASSERT(priv->numHosts == counter, 979 ("%s: hosts: %d != %d", __FUNCTION__, priv->numHosts, counter)); 980 981 /* Decrease table size if necessary */ 982 ng_bridge_rehash(priv); 983 984 /* Decrease loop counter on muted looped back links */ 985 for (counter = linkNum = 0; linkNum < NG_BRIDGE_MAX_LINKS; linkNum++) { 986 struct ng_bridge_link *const link = priv->links[linkNum]; 987 988 if (link != NULL) { 989 if (link->loopCount != 0) { 990 link->loopCount--; 991 if (link->loopCount == 0 992 && priv->conf.debugLevel >= 2) { 993 log(LOG_INFO, "ng_bridge: %s:" 994 " restoring looped back link%d\n", 995 ng_bridge_nodename(node), linkNum); 996 } 997 } 998 counter++; 999 } 1000 } 1001 KASSERT(priv->numLinks == counter, 1002 ("%s: links: %d != %d", __FUNCTION__, priv->numLinks, counter)); 1003 1004 /* Done */ 1005 splx(s); 1006 } 1007 1008 /* 1009 * Return node's "name", even if it doesn't have one. 1010 */ 1011 static const char * 1012 ng_bridge_nodename(node_p node) 1013 { 1014 static char name[NG_NODELEN+1]; 1015 1016 if (node->name != NULL) 1017 snprintf(name, sizeof(name), "%s", node->name); 1018 else 1019 snprintf(name, sizeof(name), "[%x]", ng_node2ID(node)); 1020 return name; 1021 } 1022 1023