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 1.10 2007/06/03 20:51:12 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 #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, 1, 1, 1); 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); 305 if (priv == NULL) 306 return (ENOMEM); 307 bzero(priv, sizeof(*priv)); 308 callout_init(&priv->timer); 309 310 /* Allocate and initialize hash table, etc. */ 311 MALLOC(priv->tab, struct ng_bridge_bucket *, 312 MIN_BUCKETS * sizeof(*priv->tab), M_NETGRAPH, M_NOWAIT); 313 if (priv->tab == NULL) { 314 FREE(priv, M_NETGRAPH); 315 return (ENOMEM); 316 } 317 bzero(priv->tab, MIN_BUCKETS * sizeof(*priv->tab)); /* init SLIST's */ 318 priv->numBuckets = MIN_BUCKETS; 319 priv->hashMask = MIN_BUCKETS - 1; 320 priv->conf.debugLevel = 1; 321 priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT; 322 priv->conf.maxStaleness = DEFAULT_MAX_STALENESS; 323 priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE; 324 325 /* Call superclass constructor */ 326 if ((error = ng_make_node_common(&ng_bridge_typestruct, nodep))) { 327 FREE(priv, M_NETGRAPH); 328 return (error); 329 } 330 (*nodep)->private = priv; 331 priv->node = *nodep; 332 333 /* Start timer; timer is always running while node is alive */ 334 callout_reset(&priv->timer, hz, ng_bridge_timeout, priv->node); 335 336 /* Done */ 337 return (0); 338 } 339 340 /* 341 * Method for attaching a new hook 342 */ 343 static int 344 ng_bridge_newhook(node_p node, hook_p hook, const char *name) 345 { 346 const priv_p priv = node->private; 347 348 /* Check for a link hook */ 349 if (strncmp(name, NG_BRIDGE_HOOK_LINK_PREFIX, 350 strlen(NG_BRIDGE_HOOK_LINK_PREFIX)) == 0) { 351 const char *cp; 352 char *eptr; 353 u_long linkNum; 354 355 cp = name + strlen(NG_BRIDGE_HOOK_LINK_PREFIX); 356 if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0')) 357 return (EINVAL); 358 linkNum = strtoul(cp, &eptr, 10); 359 if (*eptr != '\0' || linkNum >= NG_BRIDGE_MAX_LINKS) 360 return (EINVAL); 361 if (priv->links[linkNum] != NULL) 362 return (EISCONN); 363 MALLOC(priv->links[linkNum], struct ng_bridge_link *, 364 sizeof(*priv->links[linkNum]), M_NETGRAPH, M_NOWAIT); 365 if (priv->links[linkNum] == NULL) 366 return (ENOMEM); 367 bzero(priv->links[linkNum], sizeof(*priv->links[linkNum])); 368 priv->links[linkNum]->hook = hook; 369 LINK_NUM(hook) = linkNum; 370 priv->numLinks++; 371 return (0); 372 } 373 374 /* Unknown hook name */ 375 return (EINVAL); 376 } 377 378 /* 379 * Receive a control message 380 */ 381 static int 382 ng_bridge_rcvmsg(node_p node, struct ng_mesg *msg, 383 const char *retaddr, struct ng_mesg **rptr) 384 { 385 const priv_p priv = node->private; 386 struct ng_mesg *resp = NULL; 387 int error = 0; 388 389 switch (msg->header.typecookie) { 390 case NGM_BRIDGE_COOKIE: 391 switch (msg->header.cmd) { 392 case NGM_BRIDGE_GET_CONFIG: 393 { 394 struct ng_bridge_config *conf; 395 396 NG_MKRESPONSE(resp, msg, 397 sizeof(struct ng_bridge_config), M_NOWAIT); 398 if (resp == NULL) { 399 error = ENOMEM; 400 break; 401 } 402 conf = (struct ng_bridge_config *)resp->data; 403 *conf = priv->conf; /* no sanity checking needed */ 404 break; 405 } 406 case NGM_BRIDGE_SET_CONFIG: 407 { 408 struct ng_bridge_config *conf; 409 int i; 410 411 if (msg->header.arglen 412 != sizeof(struct ng_bridge_config)) { 413 error = EINVAL; 414 break; 415 } 416 conf = (struct ng_bridge_config *)msg->data; 417 priv->conf = *conf; 418 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) 419 priv->conf.ipfw[i] = !!priv->conf.ipfw[i]; 420 break; 421 } 422 case NGM_BRIDGE_RESET: 423 { 424 int i; 425 426 /* Flush all entries in the hash table */ 427 ng_bridge_remove_hosts(priv, -1); 428 429 /* Reset all loop detection counters and stats */ 430 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) { 431 if (priv->links[i] == NULL) 432 continue; 433 priv->links[i]->loopCount = 0; 434 bzero(&priv->links[i]->stats, 435 sizeof(priv->links[i]->stats)); 436 } 437 break; 438 } 439 case NGM_BRIDGE_GET_STATS: 440 case NGM_BRIDGE_CLR_STATS: 441 case NGM_BRIDGE_GETCLR_STATS: 442 { 443 struct ng_bridge_link *link; 444 int linkNum; 445 446 /* Get link number */ 447 if (msg->header.arglen != sizeof(u_int32_t)) { 448 error = EINVAL; 449 break; 450 } 451 linkNum = *((u_int32_t *)msg->data); 452 if (linkNum < 0 || linkNum >= NG_BRIDGE_MAX_LINKS) { 453 error = EINVAL; 454 break; 455 } 456 if ((link = priv->links[linkNum]) == NULL) { 457 error = ENOTCONN; 458 break; 459 } 460 461 /* Get/clear stats */ 462 if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) { 463 NG_MKRESPONSE(resp, msg, 464 sizeof(link->stats), M_NOWAIT); 465 if (resp == NULL) { 466 error = ENOMEM; 467 break; 468 } 469 bcopy(&link->stats, 470 resp->data, sizeof(link->stats)); 471 } 472 if (msg->header.cmd != NGM_BRIDGE_GET_STATS) 473 bzero(&link->stats, sizeof(link->stats)); 474 break; 475 } 476 case NGM_BRIDGE_GET_TABLE: 477 { 478 struct ng_bridge_host_ary *ary; 479 struct ng_bridge_hent *hent; 480 int i = 0, bucket; 481 482 NG_MKRESPONSE(resp, msg, sizeof(*ary) 483 + (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT); 484 if (resp == NULL) { 485 error = ENOMEM; 486 break; 487 } 488 ary = (struct ng_bridge_host_ary *)resp->data; 489 ary->numHosts = priv->numHosts; 490 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 491 SLIST_FOREACH(hent, &priv->tab[bucket], next) 492 ary->hosts[i++] = hent->host; 493 } 494 break; 495 } 496 default: 497 error = EINVAL; 498 break; 499 } 500 break; 501 default: 502 error = EINVAL; 503 break; 504 } 505 506 /* Done */ 507 if (rptr) 508 *rptr = resp; 509 else if (resp != NULL) 510 FREE(resp, M_NETGRAPH); 511 FREE(msg, M_NETGRAPH); 512 return (error); 513 } 514 515 /* 516 * Receive data on a hook 517 */ 518 static int 519 ng_bridge_rcvdata(hook_p hook, struct mbuf *m, meta_p meta) 520 { 521 const node_p node = hook->node; 522 const priv_p priv = node->private; 523 struct ng_bridge_host *host; 524 struct ng_bridge_link *link; 525 struct ether_header *eh; 526 int error = 0, linkNum; 527 int i, manycast; 528 529 /* Get link number */ 530 linkNum = LINK_NUM(hook); 531 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 532 ("%s: linkNum=%u", __func__, linkNum)); 533 link = priv->links[linkNum]; 534 KASSERT(link != NULL, ("%s: link%d null", __func__, linkNum)); 535 536 /* Sanity check packet and pull up header */ 537 if (m->m_pkthdr.len < ETHER_HDR_LEN) { 538 link->stats.recvRunts++; 539 NG_FREE_DATA(m, meta); 540 return (EINVAL); 541 } 542 if (m->m_len < ETHER_HDR_LEN && !(m = m_pullup(m, ETHER_HDR_LEN))) { 543 link->stats.memoryFailures++; 544 NG_FREE_META(meta); 545 return (ENOBUFS); 546 } 547 eh = mtod(m, struct ether_header *); 548 if ((eh->ether_shost[0] & 1) != 0) { 549 link->stats.recvInvalid++; 550 NG_FREE_DATA(m, meta); 551 return (EINVAL); 552 } 553 554 /* Is link disabled due to a loopback condition? */ 555 if (link->loopCount != 0) { 556 link->stats.loopDrops++; 557 NG_FREE_DATA(m, meta); 558 return (ELOOP); /* XXX is this an appropriate error? */ 559 } 560 561 /* Update stats */ 562 link->stats.recvPackets++; 563 link->stats.recvOctets += m->m_pkthdr.len; 564 if ((manycast = (eh->ether_dhost[0] & 1)) != 0) { 565 if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) { 566 link->stats.recvBroadcasts++; 567 manycast = 2; 568 } else 569 link->stats.recvMulticasts++; 570 } 571 572 /* Look up packet's source Ethernet address in hashtable */ 573 if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) { 574 575 /* Update time since last heard from this host */ 576 host->staleness = 0; 577 578 /* Did host jump to a different link? */ 579 if (host->linkNum != linkNum) { 580 581 /* 582 * If the host's old link was recently established 583 * on the old link and it's already jumped to a new 584 * link, declare a loopback condition. 585 */ 586 if (host->age < priv->conf.minStableAge) { 587 588 /* Log the problem */ 589 if (priv->conf.debugLevel >= 2) { 590 struct ifnet *ifp = m->m_pkthdr.rcvif; 591 char suffix[32]; 592 593 if (ifp != NULL) 594 ksnprintf(suffix, sizeof(suffix), 595 " (%s)", ifp->if_xname); 596 else 597 *suffix = '\0'; 598 log(LOG_WARNING, "ng_bridge: %s:" 599 " loopback detected on %s%s\n", 600 ng_bridge_nodename(node), 601 hook->name, suffix); 602 } 603 604 /* Mark link as linka non grata */ 605 link->loopCount = priv->conf.loopTimeout; 606 link->stats.loopDetects++; 607 608 /* Forget all hosts on this link */ 609 ng_bridge_remove_hosts(priv, linkNum); 610 611 /* Drop packet */ 612 link->stats.loopDrops++; 613 NG_FREE_DATA(m, meta); 614 return (ELOOP); /* XXX appropriate? */ 615 } 616 617 /* Move host over to new link */ 618 host->linkNum = linkNum; 619 host->age = 0; 620 } 621 } else { 622 if (!ng_bridge_put(priv, eh->ether_shost, linkNum)) { 623 link->stats.memoryFailures++; 624 NG_FREE_DATA(m, meta); 625 return (ENOMEM); 626 } 627 } 628 629 /* Run packet through ipfw processing, if enabled */ 630 if (priv->conf.ipfw[linkNum] && fw_enable && ip_fw_chk_ptr != NULL) { 631 /* XXX not implemented yet */ 632 } 633 634 /* 635 * If unicast and destination host known, deliver to host's link, 636 * unless it is the same link as the packet came in on. 637 */ 638 if (!manycast) { 639 640 /* Determine packet destination link */ 641 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) { 642 struct ng_bridge_link *const destLink 643 = priv->links[host->linkNum]; 644 645 /* If destination same as incoming link, do nothing */ 646 KASSERT(destLink != NULL, 647 ("%s: link%d null", __func__, host->linkNum)); 648 if (destLink == link) { 649 NG_FREE_DATA(m, meta); 650 return (0); 651 } 652 653 /* Deliver packet out the destination link */ 654 destLink->stats.xmitPackets++; 655 destLink->stats.xmitOctets += m->m_pkthdr.len; 656 NG_SEND_DATA(error, destLink->hook, m, meta); 657 return (error); 658 } 659 660 /* Destination host is not known */ 661 link->stats.recvUnknown++; 662 } 663 664 /* Distribute unknown, multicast, broadcast pkts to all other links */ 665 for (linkNum = i = 0; i < priv->numLinks - 1; linkNum++) { 666 struct ng_bridge_link *const destLink = priv->links[linkNum]; 667 meta_p meta2 = NULL; 668 struct mbuf *m2; 669 670 /* Skip incoming link and disconnected links */ 671 if (destLink == NULL || destLink == link) 672 continue; 673 674 /* Copy mbuf and meta info */ 675 if (++i == priv->numLinks - 1) { /* last link */ 676 m2 = m; 677 meta2 = meta; 678 } else { 679 m2 = m_dup(m, M_NOWAIT); /* XXX m_copypacket() */ 680 if (m2 == NULL) { 681 link->stats.memoryFailures++; 682 NG_FREE_DATA(m, meta); 683 return (ENOBUFS); 684 } 685 if (meta != NULL 686 && (meta2 = ng_copy_meta(meta)) == NULL) { 687 link->stats.memoryFailures++; 688 m_freem(m2); 689 NG_FREE_DATA(m, meta); 690 return (ENOMEM); 691 } 692 } 693 694 /* Update stats */ 695 destLink->stats.xmitPackets++; 696 destLink->stats.xmitOctets += m->m_pkthdr.len; 697 switch (manycast) { 698 case 0: /* unicast */ 699 break; 700 case 1: /* multicast */ 701 destLink->stats.xmitMulticasts++; 702 break; 703 case 2: /* broadcast */ 704 destLink->stats.xmitBroadcasts++; 705 break; 706 } 707 708 /* Send packet */ 709 NG_SEND_DATA(error, destLink->hook, m2, meta2); 710 } 711 return (error); 712 } 713 714 /* 715 * Shutdown node 716 */ 717 static int 718 ng_bridge_rmnode(node_p node) 719 { 720 const priv_p priv = node->private; 721 722 /* 723 * Shut down everything except the timer. There's no way to 724 * avoid another possible timeout event (it may have already 725 * been dequeued), so we can't free the node yet. 726 */ 727 ng_unname(node); 728 ng_cutlinks(node); /* frees all link and host info */ 729 KASSERT(priv->numLinks == 0 && priv->numHosts == 0, 730 ("%s: numLinks=%d numHosts=%d", 731 __func__, priv->numLinks, priv->numHosts)); 732 FREE(priv->tab, M_NETGRAPH); 733 734 /* NG_INVALID flag is now set so node will be freed at next timeout */ 735 return (0); 736 } 737 738 /* 739 * Hook disconnection. 740 */ 741 static int 742 ng_bridge_disconnect(hook_p hook) 743 { 744 const priv_p priv = hook->node->private; 745 int linkNum; 746 747 /* Get link number */ 748 linkNum = LINK_NUM(hook); 749 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 750 ("%s: linkNum=%u", __func__, linkNum)); 751 752 /* Remove all hosts associated with this link */ 753 ng_bridge_remove_hosts(priv, linkNum); 754 755 /* Free associated link information */ 756 KASSERT(priv->links[linkNum] != NULL, ("%s: no link", __func__)); 757 FREE(priv->links[linkNum], M_NETGRAPH); 758 priv->links[linkNum] = NULL; 759 priv->numLinks--; 760 761 /* If no more hooks, go away */ 762 if (hook->node->numhooks == 0) 763 ng_rmnode(hook->node); 764 return (0); 765 } 766 767 /****************************************************************** 768 HASH TABLE FUNCTIONS 769 ******************************************************************/ 770 771 /* 772 * Hash algorithm 773 * 774 * Only hashing bytes 3-6 of the Ethernet address is sufficient and fast. 775 */ 776 #define HASH(addr,mask) ( (((const u_int16_t *)(addr))[0] \ 777 ^ ((const u_int16_t *)(addr))[1] \ 778 ^ ((const u_int16_t *)(addr))[2]) & (mask) ) 779 780 /* 781 * Find a host entry in the table. 782 */ 783 static struct ng_bridge_host * 784 ng_bridge_get(priv_p priv, const u_char *addr) 785 { 786 const int bucket = HASH(addr, priv->hashMask); 787 struct ng_bridge_hent *hent; 788 789 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 790 if (ETHER_EQUAL(hent->host.addr, addr)) 791 return (&hent->host); 792 } 793 return (NULL); 794 } 795 796 /* 797 * Add a new host entry to the table. This assumes the host doesn't 798 * already exist in the table. Returns 1 on success, 0 if there 799 * was a memory allocation failure. 800 */ 801 static int 802 ng_bridge_put(priv_p priv, const u_char *addr, int linkNum) 803 { 804 const int bucket = HASH(addr, priv->hashMask); 805 struct ng_bridge_hent *hent; 806 807 #ifdef INVARIANTS 808 /* Assert that entry does not already exist in hashtable */ 809 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 810 KASSERT(!ETHER_EQUAL(hent->host.addr, addr), 811 ("%s: entry %6D exists in table", __func__, addr, ":")); 812 } 813 #endif 814 815 /* Allocate and initialize new hashtable entry */ 816 MALLOC(hent, struct ng_bridge_hent *, 817 sizeof(*hent), M_NETGRAPH, M_NOWAIT); 818 if (hent == NULL) 819 return (0); 820 bcopy(addr, hent->host.addr, ETHER_ADDR_LEN); 821 hent->host.linkNum = linkNum; 822 hent->host.staleness = 0; 823 hent->host.age = 0; 824 825 /* Add new element to hash bucket */ 826 SLIST_INSERT_HEAD(&priv->tab[bucket], hent, next); 827 priv->numHosts++; 828 829 /* Resize table if necessary */ 830 ng_bridge_rehash(priv); 831 return (1); 832 } 833 834 /* 835 * Resize the hash table. We try to maintain the number of buckets 836 * such that the load factor is in the range 0.25 to 1.0. 837 * 838 * If we can't get the new memory then we silently fail. This is OK 839 * because things will still work and we'll try again soon anyway. 840 */ 841 static void 842 ng_bridge_rehash(priv_p priv) 843 { 844 struct ng_bridge_bucket *newTab; 845 int oldBucket, newBucket; 846 int newNumBuckets; 847 u_int newMask; 848 849 /* Is table too full or too empty? */ 850 if (priv->numHosts > priv->numBuckets 851 && (priv->numBuckets << 1) <= MAX_BUCKETS) 852 newNumBuckets = priv->numBuckets << 1; 853 else if (priv->numHosts < (priv->numBuckets >> 2) 854 && (priv->numBuckets >> 2) >= MIN_BUCKETS) 855 newNumBuckets = priv->numBuckets >> 2; 856 else 857 return; 858 newMask = newNumBuckets - 1; 859 860 /* Allocate and initialize new table */ 861 MALLOC(newTab, struct ng_bridge_bucket *, 862 newNumBuckets * sizeof(*newTab), M_NETGRAPH, M_NOWAIT); 863 if (newTab == NULL) 864 return; 865 bzero(newTab, newNumBuckets * sizeof(*newTab)); 866 867 /* Move all entries from old table to new table */ 868 for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) { 869 struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket]; 870 871 while (!SLIST_EMPTY(oldList)) { 872 struct ng_bridge_hent *const hent 873 = SLIST_FIRST(oldList); 874 875 SLIST_REMOVE_HEAD(oldList, next); 876 newBucket = HASH(hent->host.addr, newMask); 877 SLIST_INSERT_HEAD(&newTab[newBucket], hent, next); 878 } 879 } 880 881 /* Replace old table with new one */ 882 if (priv->conf.debugLevel >= 3) { 883 log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n", 884 ng_bridge_nodename(priv->node), 885 priv->numBuckets, newNumBuckets); 886 } 887 FREE(priv->tab, M_NETGRAPH); 888 priv->numBuckets = newNumBuckets; 889 priv->hashMask = newMask; 890 priv->tab = newTab; 891 return; 892 } 893 894 /****************************************************************** 895 MISC FUNCTIONS 896 ******************************************************************/ 897 898 /* 899 * Remove all hosts associated with a specific link from the hashtable. 900 * If linkNum == -1, then remove all hosts in the table. 901 */ 902 static void 903 ng_bridge_remove_hosts(priv_p priv, int linkNum) 904 { 905 int bucket; 906 907 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 908 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 909 910 while (*hptr != NULL) { 911 struct ng_bridge_hent *const hent = *hptr; 912 913 if (linkNum == -1 || hent->host.linkNum == linkNum) { 914 *hptr = SLIST_NEXT(hent, next); 915 FREE(hent, M_NETGRAPH); 916 priv->numHosts--; 917 } else 918 hptr = &SLIST_NEXT(hent, next); 919 } 920 } 921 } 922 923 /* 924 * Handle our once-per-second timeout event. We do two things: 925 * we decrement link->loopCount for those links being muted due to 926 * a detected loopback condition, and we remove any hosts from 927 * the hashtable whom we haven't heard from in a long while. 928 * 929 * If the node has the NG_INVALID flag set, our job is to kill it. 930 */ 931 static void 932 ng_bridge_timeout(void *arg) 933 { 934 const node_p node = arg; 935 const priv_p priv = node->private; 936 int bucket; 937 int counter = 0; 938 int linkNum; 939 940 /* If node was shut down, this is the final lingering timeout */ 941 crit_enter(); 942 if ((node->flags & NG_INVALID) != 0) { 943 FREE(priv, M_NETGRAPH); 944 node->private = NULL; 945 ng_unref(node); 946 crit_exit(); 947 return; 948 } 949 950 /* Register a new timeout, keeping the existing node reference */ 951 callout_reset(&priv->timer, hz, ng_bridge_timeout, node); 952 953 /* Update host time counters and remove stale entries */ 954 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 955 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 956 957 while (*hptr != NULL) { 958 struct ng_bridge_hent *const hent = *hptr; 959 960 /* Make sure host's link really exists */ 961 KASSERT(priv->links[hent->host.linkNum] != NULL, 962 ("%s: host %6D on nonexistent link %d\n", 963 __func__, hent->host.addr, ":", 964 hent->host.linkNum)); 965 966 /* Remove hosts we haven't heard from in a while */ 967 if (++hent->host.staleness >= priv->conf.maxStaleness) { 968 *hptr = SLIST_NEXT(hent, next); 969 FREE(hent, M_NETGRAPH); 970 priv->numHosts--; 971 } else { 972 if (hent->host.age < 0xffff) 973 hent->host.age++; 974 hptr = &SLIST_NEXT(hent, next); 975 counter++; 976 } 977 } 978 } 979 KASSERT(priv->numHosts == counter, 980 ("%s: hosts: %d != %d", __func__, priv->numHosts, counter)); 981 982 /* Decrease table size if necessary */ 983 ng_bridge_rehash(priv); 984 985 /* Decrease loop counter on muted looped back links */ 986 for (counter = linkNum = 0; linkNum < NG_BRIDGE_MAX_LINKS; linkNum++) { 987 struct ng_bridge_link *const link = priv->links[linkNum]; 988 989 if (link != NULL) { 990 if (link->loopCount != 0) { 991 link->loopCount--; 992 if (link->loopCount == 0 993 && priv->conf.debugLevel >= 2) { 994 log(LOG_INFO, "ng_bridge: %s:" 995 " restoring looped back link%d\n", 996 ng_bridge_nodename(node), linkNum); 997 } 998 } 999 counter++; 1000 } 1001 } 1002 KASSERT(priv->numLinks == counter, 1003 ("%s: links: %d != %d", __func__, priv->numLinks, counter)); 1004 1005 /* Done */ 1006 crit_exit(); 1007 } 1008 1009 /* 1010 * Return node's "name", even if it doesn't have one. 1011 */ 1012 static const char * 1013 ng_bridge_nodename(node_p node) 1014 { 1015 static char name[NG_NODESIZ]; 1016 1017 if (node->name != NULL) 1018 ksnprintf(name, sizeof(name), "%s", node->name); 1019 else 1020 ksnprintf(name, sizeof(name), "[%x]", ng_node2ID(node)); 1021 return name; 1022 } 1023 1024