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 * $FreeBSD$ 40 */ 41 42 /* 43 * ng_bridge(4) netgraph node type 44 * 45 * The node performs standard intelligent Ethernet bridging over 46 * each of its connected hooks, or links. A simple loop detection 47 * algorithm is included which disables a link for priv->conf.loopTimeout 48 * seconds when a host is seen to have jumped from one link to 49 * another within priv->conf.minStableAge seconds. 50 * 51 * We keep a hashtable that maps Ethernet addresses to host info, 52 * which is contained in struct ng_bridge_host's. These structures 53 * tell us on which link the host may be found. A host's entry will 54 * expire after priv->conf.maxStaleness seconds. 55 * 56 * This node is optimzed for stable networks, where machines jump 57 * from one port to the other only rarely. 58 */ 59 60 #include <sys/param.h> 61 #include <sys/systm.h> 62 #include <sys/kernel.h> 63 #include <sys/malloc.h> 64 #include <sys/mbuf.h> 65 #include <sys/errno.h> 66 #include <sys/syslog.h> 67 #include <sys/socket.h> 68 #include <sys/ctype.h> 69 70 #include <net/if.h> 71 #include <net/ethernet.h> 72 73 #include <netinet/in.h> 74 #include <netinet/ip_fw.h> 75 76 #include <netgraph/ng_message.h> 77 #include <netgraph/netgraph.h> 78 #include <netgraph/ng_parse.h> 79 #include <netgraph/ng_bridge.h> 80 81 #ifdef NG_SEPARATE_MALLOC 82 MALLOC_DEFINE(M_NETGRAPH_BRIDGE, "netgraph_bridge", "netgraph bridge node "); 83 #else 84 #define M_NETGRAPH_BRIDGE M_NETGRAPH 85 #endif 86 87 /* Per-link private data */ 88 struct ng_bridge_link { 89 hook_p hook; /* netgraph hook */ 90 u_int16_t loopCount; /* loop ignore timer */ 91 struct ng_bridge_link_stats stats; /* link stats */ 92 }; 93 94 /* Per-node private data */ 95 struct ng_bridge_private { 96 struct ng_bridge_bucket *tab; /* hash table bucket array */ 97 struct ng_bridge_link *links[NG_BRIDGE_MAX_LINKS]; 98 struct ng_bridge_config conf; /* node configuration */ 99 node_p node; /* netgraph node */ 100 u_int numHosts; /* num entries in table */ 101 u_int numBuckets; /* num buckets in table */ 102 u_int hashMask; /* numBuckets - 1 */ 103 int numLinks; /* num connected links */ 104 struct callout timer; /* one second periodic timer */ 105 }; 106 typedef struct ng_bridge_private *priv_p; 107 108 /* Information about a host, stored in a hash table entry */ 109 struct ng_bridge_hent { 110 struct ng_bridge_host host; /* actual host info */ 111 SLIST_ENTRY(ng_bridge_hent) next; /* next entry in bucket */ 112 }; 113 114 /* Hash table bucket declaration */ 115 SLIST_HEAD(ng_bridge_bucket, ng_bridge_hent); 116 117 /* Netgraph node methods */ 118 static ng_constructor_t ng_bridge_constructor; 119 static ng_rcvmsg_t ng_bridge_rcvmsg; 120 static ng_shutdown_t ng_bridge_shutdown; 121 static ng_newhook_t ng_bridge_newhook; 122 static ng_rcvdata_t ng_bridge_rcvdata; 123 static ng_disconnect_t ng_bridge_disconnect; 124 125 /* Other internal functions */ 126 static struct ng_bridge_host *ng_bridge_get(priv_p priv, const u_char *addr); 127 static int ng_bridge_put(priv_p priv, const u_char *addr, int linkNum); 128 static void ng_bridge_rehash(priv_p priv); 129 static void ng_bridge_remove_hosts(priv_p priv, int linkNum); 130 static void ng_bridge_timeout(void *arg); 131 static const char *ng_bridge_nodename(node_p node); 132 133 /* Ethernet broadcast */ 134 static const u_char ng_bridge_bcast_addr[ETHER_ADDR_LEN] = 135 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; 136 137 /* Store each hook's link number in the private field */ 138 #define LINK_NUM(hook) (*(u_int16_t *)(&(hook)->private)) 139 140 /* Compare Ethernet addresses using 32 and 16 bit words instead of bytewise */ 141 #define ETHER_EQUAL(a,b) (((const u_int32_t *)(a))[0] \ 142 == ((const u_int32_t *)(b))[0] \ 143 && ((const u_int16_t *)(a))[2] \ 144 == ((const u_int16_t *)(b))[2]) 145 146 /* Minimum and maximum number of hash buckets. Must be a power of two. */ 147 #define MIN_BUCKETS (1 << 5) /* 32 */ 148 #define MAX_BUCKETS (1 << 14) /* 16384 */ 149 150 /* Configuration default values */ 151 #define DEFAULT_LOOP_TIMEOUT 60 152 #define DEFAULT_MAX_STALENESS (15 * 60) /* same as ARP timeout */ 153 #define DEFAULT_MIN_STABLE_AGE 1 154 155 /****************************************************************** 156 NETGRAPH PARSE TYPES 157 ******************************************************************/ 158 159 /* 160 * How to determine the length of the table returned by NGM_BRIDGE_GET_TABLE 161 */ 162 static int 163 ng_bridge_getTableLength(const struct ng_parse_type *type, 164 const u_char *start, const u_char *buf) 165 { 166 const struct ng_bridge_host_ary *const hary 167 = (const struct ng_bridge_host_ary *)(buf - sizeof(u_int32_t)); 168 169 return hary->numHosts; 170 } 171 172 /* Parse type for struct ng_bridge_host_ary */ 173 static const struct ng_parse_struct_field ng_bridge_host_type_fields[] 174 = NG_BRIDGE_HOST_TYPE_INFO(&ng_parse_enaddr_type); 175 static const struct ng_parse_type ng_bridge_host_type = { 176 &ng_parse_struct_type, 177 &ng_bridge_host_type_fields 178 }; 179 static const struct ng_parse_array_info ng_bridge_hary_type_info = { 180 &ng_bridge_host_type, 181 ng_bridge_getTableLength 182 }; 183 static const struct ng_parse_type ng_bridge_hary_type = { 184 &ng_parse_array_type, 185 &ng_bridge_hary_type_info 186 }; 187 static const struct ng_parse_struct_field ng_bridge_host_ary_type_fields[] 188 = NG_BRIDGE_HOST_ARY_TYPE_INFO(&ng_bridge_hary_type); 189 static const struct ng_parse_type ng_bridge_host_ary_type = { 190 &ng_parse_struct_type, 191 &ng_bridge_host_ary_type_fields 192 }; 193 194 /* Parse type for struct ng_bridge_config */ 195 static const struct ng_parse_fixedarray_info ng_bridge_ipfwary_type_info = { 196 &ng_parse_uint8_type, 197 NG_BRIDGE_MAX_LINKS 198 }; 199 static const struct ng_parse_type ng_bridge_ipfwary_type = { 200 &ng_parse_fixedarray_type, 201 &ng_bridge_ipfwary_type_info 202 }; 203 static const struct ng_parse_struct_field ng_bridge_config_type_fields[] 204 = NG_BRIDGE_CONFIG_TYPE_INFO(&ng_bridge_ipfwary_type); 205 static const struct ng_parse_type ng_bridge_config_type = { 206 &ng_parse_struct_type, 207 &ng_bridge_config_type_fields 208 }; 209 210 /* Parse type for struct ng_bridge_link_stat */ 211 static const struct ng_parse_struct_field ng_bridge_stats_type_fields[] 212 = NG_BRIDGE_STATS_TYPE_INFO; 213 static const struct ng_parse_type ng_bridge_stats_type = { 214 &ng_parse_struct_type, 215 &ng_bridge_stats_type_fields 216 }; 217 218 /* List of commands and how to convert arguments to/from ASCII */ 219 static const struct ng_cmdlist ng_bridge_cmdlist[] = { 220 { 221 NGM_BRIDGE_COOKIE, 222 NGM_BRIDGE_SET_CONFIG, 223 "setconfig", 224 &ng_bridge_config_type, 225 NULL 226 }, 227 { 228 NGM_BRIDGE_COOKIE, 229 NGM_BRIDGE_GET_CONFIG, 230 "getconfig", 231 NULL, 232 &ng_bridge_config_type 233 }, 234 { 235 NGM_BRIDGE_COOKIE, 236 NGM_BRIDGE_RESET, 237 "reset", 238 NULL, 239 NULL 240 }, 241 { 242 NGM_BRIDGE_COOKIE, 243 NGM_BRIDGE_GET_STATS, 244 "getstats", 245 &ng_parse_uint32_type, 246 &ng_bridge_stats_type 247 }, 248 { 249 NGM_BRIDGE_COOKIE, 250 NGM_BRIDGE_CLR_STATS, 251 "clrstats", 252 &ng_parse_uint32_type, 253 NULL 254 }, 255 { 256 NGM_BRIDGE_COOKIE, 257 NGM_BRIDGE_GETCLR_STATS, 258 "getclrstats", 259 &ng_parse_uint32_type, 260 &ng_bridge_stats_type 261 }, 262 { 263 NGM_BRIDGE_COOKIE, 264 NGM_BRIDGE_GET_TABLE, 265 "gettable", 266 NULL, 267 &ng_bridge_host_ary_type 268 }, 269 { 0 } 270 }; 271 272 /* Node type descriptor */ 273 static struct ng_type ng_bridge_typestruct = { 274 NG_ABI_VERSION, 275 NG_BRIDGE_NODE_TYPE, 276 NULL, 277 ng_bridge_constructor, 278 ng_bridge_rcvmsg, 279 ng_bridge_shutdown, 280 ng_bridge_newhook, 281 NULL, 282 NULL, 283 ng_bridge_rcvdata, 284 ng_bridge_disconnect, 285 ng_bridge_cmdlist, 286 }; 287 NETGRAPH_INIT(bridge, &ng_bridge_typestruct); 288 289 /****************************************************************** 290 NETGRAPH NODE METHODS 291 ******************************************************************/ 292 293 /* 294 * Node constructor 295 */ 296 static int 297 ng_bridge_constructor(node_p node) 298 { 299 priv_p priv; 300 301 /* Allocate and initialize private info */ 302 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO); 303 if (priv == NULL) 304 return (ENOMEM); 305 callout_init(&priv->timer, 0); 306 307 /* Allocate and initialize hash table, etc. */ 308 MALLOC(priv->tab, struct ng_bridge_bucket *, 309 MIN_BUCKETS * sizeof(*priv->tab), M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO); 310 if (priv->tab == NULL) { 311 FREE(priv, M_NETGRAPH_BRIDGE); 312 return (ENOMEM); 313 } 314 priv->numBuckets = MIN_BUCKETS; 315 priv->hashMask = MIN_BUCKETS - 1; 316 priv->conf.debugLevel = 1; 317 priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT; 318 priv->conf.maxStaleness = DEFAULT_MAX_STALENESS; 319 priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE; 320 321 /* 322 * This node has all kinds of stuff that could be screwed by SMP. 323 * Until it gets it's own internal protection, we go through in 324 * single file. This could hurt a machine bridging beteen two 325 * GB ethernets so it should be fixed. 326 * When it's fixed the process SHOULD NOT SLEEP, spinlocks please! 327 * (and atomic ops ) 328 */ 329 NG_NODE_FORCE_WRITER(node); 330 NG_NODE_SET_PRIVATE(node, priv); 331 priv->node = node; 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 = NG_NODE_PRIVATE(node); 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_BRIDGE, M_NOWAIT|M_ZERO); 365 if (priv->links[linkNum] == NULL) 366 return (ENOMEM); 367 priv->links[linkNum]->hook = hook; 368 NG_HOOK_SET_PRIVATE(hook, (void *)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, item_p item, hook_p lasthook) 382 { 383 const priv_p priv = NG_NODE_PRIVATE(node); 384 struct ng_mesg *resp = NULL; 385 int error = 0; 386 struct ng_mesg *msg; 387 388 NGI_GET_MSG(item, msg); 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 NG_RESPOND_MSG(error, node, item, resp); 508 NG_FREE_MSG(msg); 509 return (error); 510 } 511 512 /* 513 * Receive data on a hook 514 */ 515 static int 516 ng_bridge_rcvdata(hook_p hook, item_p item) 517 { 518 const node_p node = NG_HOOK_NODE(hook); 519 const priv_p priv = NG_NODE_PRIVATE(node); 520 struct ng_bridge_host *host; 521 struct ng_bridge_link *link; 522 struct ether_header *eh; 523 int error = 0, linkNum; 524 int manycast; 525 struct mbuf *m; 526 meta_p meta; 527 struct ng_bridge_link *firstLink; 528 529 NGI_GET_M(item, m); 530 /* Get link number */ 531 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook); 532 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 533 ("%s: linkNum=%u", __func__, linkNum)); 534 link = priv->links[linkNum]; 535 KASSERT(link != NULL, ("%s: link%d null", __func__, linkNum)); 536 537 /* Sanity check packet and pull up header */ 538 if (m->m_pkthdr.len < ETHER_HDR_LEN) { 539 link->stats.recvRunts++; 540 NG_FREE_ITEM(item); 541 NG_FREE_M(m); 542 return (EINVAL); 543 } 544 if (m->m_len < ETHER_HDR_LEN && !(m = m_pullup(m, ETHER_HDR_LEN))) { 545 link->stats.memoryFailures++; 546 NG_FREE_ITEM(item); 547 return (ENOBUFS); 548 } 549 eh = mtod(m, struct ether_header *); 550 if ((eh->ether_shost[0] & 1) != 0) { 551 link->stats.recvInvalid++; 552 NG_FREE_ITEM(item); 553 NG_FREE_M(m); 554 return (EINVAL); 555 } 556 557 /* Is link disabled due to a loopback condition? */ 558 if (link->loopCount != 0) { 559 link->stats.loopDrops++; 560 NG_FREE_ITEM(item); 561 NG_FREE_M(m); 562 return (ELOOP); /* XXX is this an appropriate error? */ 563 } 564 565 /* Update stats */ 566 link->stats.recvPackets++; 567 link->stats.recvOctets += m->m_pkthdr.len; 568 if ((manycast = (eh->ether_dhost[0] & 1)) != 0) { 569 if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) { 570 link->stats.recvBroadcasts++; 571 manycast = 2; 572 } else 573 link->stats.recvMulticasts++; 574 } 575 576 /* Look up packet's source Ethernet address in hashtable */ 577 if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) { 578 579 /* Update time since last heard from this host */ 580 host->staleness = 0; 581 582 /* Did host jump to a different link? */ 583 if (host->linkNum != linkNum) { 584 585 /* 586 * If the host's old link was recently established 587 * on the old link and it's already jumped to a new 588 * link, declare a loopback condition. 589 */ 590 if (host->age < priv->conf.minStableAge) { 591 592 /* Log the problem */ 593 if (priv->conf.debugLevel >= 2) { 594 struct ifnet *ifp = m->m_pkthdr.rcvif; 595 char suffix[32]; 596 597 if (ifp != NULL) 598 snprintf(suffix, sizeof(suffix), 599 " (%s)", ifp->if_xname); 600 else 601 *suffix = '\0'; 602 log(LOG_WARNING, "ng_bridge: %s:" 603 " loopback detected on %s%s\n", 604 ng_bridge_nodename(node), 605 NG_HOOK_NAME(hook), suffix); 606 } 607 608 /* Mark link as linka non grata */ 609 link->loopCount = priv->conf.loopTimeout; 610 link->stats.loopDetects++; 611 612 /* Forget all hosts on this link */ 613 ng_bridge_remove_hosts(priv, linkNum); 614 615 /* Drop packet */ 616 link->stats.loopDrops++; 617 NG_FREE_ITEM(item); 618 NG_FREE_M(m); 619 return (ELOOP); /* XXX appropriate? */ 620 } 621 622 /* Move host over to new link */ 623 host->linkNum = linkNum; 624 host->age = 0; 625 } 626 } else { 627 if (!ng_bridge_put(priv, eh->ether_shost, linkNum)) { 628 link->stats.memoryFailures++; 629 NG_FREE_ITEM(item); 630 NG_FREE_M(m); 631 return (ENOMEM); 632 } 633 } 634 635 /* Run packet through ipfw processing, if enabled */ 636 if (priv->conf.ipfw[linkNum] && fw_enable && ip_fw_chk_ptr != NULL) { 637 /* XXX not implemented yet */ 638 } 639 640 /* 641 * If unicast and destination host known, deliver to host's link, 642 * unless it is the same link as the packet came in on. 643 */ 644 if (!manycast) { 645 646 /* Determine packet destination link */ 647 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) { 648 struct ng_bridge_link *const destLink 649 = priv->links[host->linkNum]; 650 651 /* If destination same as incoming link, do nothing */ 652 KASSERT(destLink != NULL, 653 ("%s: link%d null", __func__, host->linkNum)); 654 if (destLink == link) { 655 NG_FREE_ITEM(item); 656 NG_FREE_M(m); 657 return (0); 658 } 659 660 /* Deliver packet out the destination link */ 661 destLink->stats.xmitPackets++; 662 destLink->stats.xmitOctets += m->m_pkthdr.len; 663 NG_FWD_NEW_DATA(error, item, destLink->hook, m); 664 return (error); 665 } 666 667 /* Destination host is not known */ 668 link->stats.recvUnknown++; 669 } 670 671 /* Distribute unknown, multicast, broadcast pkts to all other links */ 672 meta = NGI_META(item); /* peek.. */ 673 firstLink = NULL; 674 for (linkNum = 0; linkNum <= priv->numLinks; linkNum++) { 675 struct ng_bridge_link *destLink; 676 meta_p meta2 = NULL; 677 struct mbuf *m2 = NULL; 678 679 /* 680 * If we have checked all the links then now 681 * send the original on its reserved link 682 */ 683 if (linkNum == priv->numLinks) { 684 /* If we never saw a good link, leave. */ 685 if (firstLink == NULL) { 686 NG_FREE_ITEM(item); 687 NG_FREE_M(m); 688 return (0); 689 } 690 destLink = firstLink; 691 } else { 692 destLink = priv->links[linkNum]; 693 /* Skip incoming link and disconnected links */ 694 if (destLink == NULL || destLink == link) { 695 continue; 696 } 697 if (firstLink == NULL) { 698 /* 699 * This is the first usable link we have found. 700 * Reserve it for the originals. 701 * If we never find another we save a copy. 702 */ 703 firstLink = destLink; 704 continue; 705 } 706 707 /* 708 * It's usable link but not the reserved (first) one. 709 * Copy mbuf and meta info for sending. 710 */ 711 m2 = m_dup(m, M_DONTWAIT); /* XXX m_copypacket() */ 712 if (m2 == NULL) { 713 link->stats.memoryFailures++; 714 NG_FREE_ITEM(item); 715 NG_FREE_M(m); 716 return (ENOBUFS); 717 } 718 if (meta != NULL 719 && (meta2 = ng_copy_meta(meta)) == NULL) { 720 link->stats.memoryFailures++; 721 m_freem(m2); 722 NG_FREE_ITEM(item); 723 NG_FREE_M(m); 724 return (ENOMEM); 725 } 726 } 727 728 /* Update stats */ 729 destLink->stats.xmitPackets++; 730 destLink->stats.xmitOctets += m->m_pkthdr.len; 731 switch (manycast) { 732 case 0: /* unicast */ 733 break; 734 case 1: /* multicast */ 735 destLink->stats.xmitMulticasts++; 736 break; 737 case 2: /* broadcast */ 738 destLink->stats.xmitBroadcasts++; 739 break; 740 } 741 742 /* Send packet */ 743 if (destLink == firstLink) { 744 /* 745 * If we've sent all the others, send the original 746 * on the first link we found. 747 */ 748 NG_FWD_NEW_DATA(error, item, destLink->hook, m); 749 break; /* always done last - not really needed. */ 750 } else { 751 NG_SEND_DATA(error, destLink->hook, m2, meta2); 752 } 753 } 754 return (error); 755 } 756 757 /* 758 * Shutdown node 759 */ 760 static int 761 ng_bridge_shutdown(node_p node) 762 { 763 const priv_p priv = NG_NODE_PRIVATE(node); 764 765 /* 766 * Shut down everything except the timer. There's no way to 767 * avoid another possible timeout event (it may have already 768 * been dequeued), so we can't free the node yet. 769 */ 770 KASSERT(priv->numLinks == 0 && priv->numHosts == 0, 771 ("%s: numLinks=%d numHosts=%d", 772 __func__, priv->numLinks, priv->numHosts)); 773 FREE(priv->tab, M_NETGRAPH_BRIDGE); 774 775 /* NG_INVALID flag is now set so node will be freed at next timeout */ 776 return (0); 777 } 778 779 /* 780 * Hook disconnection. 781 */ 782 static int 783 ng_bridge_disconnect(hook_p hook) 784 { 785 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); 786 int linkNum; 787 788 /* Get link number */ 789 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook); 790 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 791 ("%s: linkNum=%u", __func__, linkNum)); 792 793 /* Remove all hosts associated with this link */ 794 ng_bridge_remove_hosts(priv, linkNum); 795 796 /* Free associated link information */ 797 KASSERT(priv->links[linkNum] != NULL, ("%s: no link", __func__)); 798 FREE(priv->links[linkNum], M_NETGRAPH_BRIDGE); 799 priv->links[linkNum] = NULL; 800 priv->numLinks--; 801 802 /* If no more hooks, go away */ 803 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) 804 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) { 805 ng_rmnode_self(NG_HOOK_NODE(hook)); 806 } 807 return (0); 808 } 809 810 /****************************************************************** 811 HASH TABLE FUNCTIONS 812 ******************************************************************/ 813 814 /* 815 * Hash algorithm 816 */ 817 #define HASH(addr,mask) ( (((const u_int16_t *)(addr))[0] \ 818 ^ ((const u_int16_t *)(addr))[1] \ 819 ^ ((const u_int16_t *)(addr))[2]) & (mask) ) 820 821 /* 822 * Find a host entry in the table. 823 */ 824 static struct ng_bridge_host * 825 ng_bridge_get(priv_p priv, const u_char *addr) 826 { 827 const int bucket = HASH(addr, priv->hashMask); 828 struct ng_bridge_hent *hent; 829 830 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 831 if (ETHER_EQUAL(hent->host.addr, addr)) 832 return (&hent->host); 833 } 834 return (NULL); 835 } 836 837 /* 838 * Add a new host entry to the table. This assumes the host doesn't 839 * already exist in the table. Returns 1 on success, 0 if there 840 * was a memory allocation failure. 841 */ 842 static int 843 ng_bridge_put(priv_p priv, const u_char *addr, int linkNum) 844 { 845 const int bucket = HASH(addr, priv->hashMask); 846 struct ng_bridge_hent *hent; 847 848 #ifdef INVARIANTS 849 /* Assert that entry does not already exist in hashtable */ 850 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 851 KASSERT(!ETHER_EQUAL(hent->host.addr, addr), 852 ("%s: entry %6D exists in table", __func__, addr, ":")); 853 } 854 #endif 855 856 /* Allocate and initialize new hashtable entry */ 857 MALLOC(hent, struct ng_bridge_hent *, 858 sizeof(*hent), M_NETGRAPH_BRIDGE, M_NOWAIT); 859 if (hent == NULL) 860 return (0); 861 bcopy(addr, hent->host.addr, ETHER_ADDR_LEN); 862 hent->host.linkNum = linkNum; 863 hent->host.staleness = 0; 864 hent->host.age = 0; 865 866 /* Add new element to hash bucket */ 867 SLIST_INSERT_HEAD(&priv->tab[bucket], hent, next); 868 priv->numHosts++; 869 870 /* Resize table if necessary */ 871 ng_bridge_rehash(priv); 872 return (1); 873 } 874 875 /* 876 * Resize the hash table. We try to maintain the number of buckets 877 * such that the load factor is in the range 0.25 to 1.0. 878 * 879 * If we can't get the new memory then we silently fail. This is OK 880 * because things will still work and we'll try again soon anyway. 881 */ 882 static void 883 ng_bridge_rehash(priv_p priv) 884 { 885 struct ng_bridge_bucket *newTab; 886 int oldBucket, newBucket; 887 int newNumBuckets; 888 u_int newMask; 889 890 /* Is table too full or too empty? */ 891 if (priv->numHosts > priv->numBuckets 892 && (priv->numBuckets << 1) <= MAX_BUCKETS) 893 newNumBuckets = priv->numBuckets << 1; 894 else if (priv->numHosts < (priv->numBuckets >> 2) 895 && (priv->numBuckets >> 2) >= MIN_BUCKETS) 896 newNumBuckets = priv->numBuckets >> 2; 897 else 898 return; 899 newMask = newNumBuckets - 1; 900 901 /* Allocate and initialize new table */ 902 MALLOC(newTab, struct ng_bridge_bucket *, 903 newNumBuckets * sizeof(*newTab), M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO); 904 if (newTab == NULL) 905 return; 906 907 /* Move all entries from old table to new table */ 908 for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) { 909 struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket]; 910 911 while (!SLIST_EMPTY(oldList)) { 912 struct ng_bridge_hent *const hent 913 = SLIST_FIRST(oldList); 914 915 SLIST_REMOVE_HEAD(oldList, next); 916 newBucket = HASH(hent->host.addr, newMask); 917 SLIST_INSERT_HEAD(&newTab[newBucket], hent, next); 918 } 919 } 920 921 /* Replace old table with new one */ 922 if (priv->conf.debugLevel >= 3) { 923 log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n", 924 ng_bridge_nodename(priv->node), 925 priv->numBuckets, newNumBuckets); 926 } 927 FREE(priv->tab, M_NETGRAPH_BRIDGE); 928 priv->numBuckets = newNumBuckets; 929 priv->hashMask = newMask; 930 priv->tab = newTab; 931 return; 932 } 933 934 /****************************************************************** 935 MISC FUNCTIONS 936 ******************************************************************/ 937 938 /* 939 * Remove all hosts associated with a specific link from the hashtable. 940 * If linkNum == -1, then remove all hosts in the table. 941 */ 942 static void 943 ng_bridge_remove_hosts(priv_p priv, int linkNum) 944 { 945 int bucket; 946 947 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 948 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 949 950 while (*hptr != NULL) { 951 struct ng_bridge_hent *const hent = *hptr; 952 953 if (linkNum == -1 || hent->host.linkNum == linkNum) { 954 *hptr = SLIST_NEXT(hent, next); 955 FREE(hent, M_NETGRAPH_BRIDGE); 956 priv->numHosts--; 957 } else 958 hptr = &SLIST_NEXT(hent, next); 959 } 960 } 961 } 962 963 /* 964 * Handle our once-per-second timeout event. We do two things: 965 * we decrement link->loopCount for those links being muted due to 966 * a detected loopback condition, and we remove any hosts from 967 * the hashtable whom we haven't heard from in a long while. 968 * 969 * If the node has the NG_INVALID flag set, our job is to kill it. 970 */ 971 static void 972 ng_bridge_timeout(void *arg) 973 { 974 const node_p node = arg; 975 const priv_p priv = NG_NODE_PRIVATE(node); 976 int s, bucket; 977 int counter = 0; 978 int linkNum; 979 980 /* If node was shut down, this is the final lingering timeout */ 981 s = splnet(); 982 if (NG_NODE_NOT_VALID(node)) { 983 FREE(priv, M_NETGRAPH_BRIDGE); 984 NG_NODE_SET_PRIVATE(node, NULL); 985 NG_NODE_UNREF(node); 986 splx(s); 987 return; 988 } 989 990 /* Register a new timeout, keeping the existing node reference */ 991 callout_reset(&priv->timer, hz, ng_bridge_timeout, node); 992 993 /* Update host time counters and remove stale entries */ 994 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 995 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 996 997 while (*hptr != NULL) { 998 struct ng_bridge_hent *const hent = *hptr; 999 1000 /* Make sure host's link really exists */ 1001 KASSERT(priv->links[hent->host.linkNum] != NULL, 1002 ("%s: host %6D on nonexistent link %d\n", 1003 __func__, hent->host.addr, ":", 1004 hent->host.linkNum)); 1005 1006 /* Remove hosts we haven't heard from in a while */ 1007 if (++hent->host.staleness >= priv->conf.maxStaleness) { 1008 *hptr = SLIST_NEXT(hent, next); 1009 FREE(hent, M_NETGRAPH_BRIDGE); 1010 priv->numHosts--; 1011 } else { 1012 if (hent->host.age < 0xffff) 1013 hent->host.age++; 1014 hptr = &SLIST_NEXT(hent, next); 1015 counter++; 1016 } 1017 } 1018 } 1019 KASSERT(priv->numHosts == counter, 1020 ("%s: hosts: %d != %d", __func__, priv->numHosts, counter)); 1021 1022 /* Decrease table size if necessary */ 1023 ng_bridge_rehash(priv); 1024 1025 /* Decrease loop counter on muted looped back links */ 1026 for (counter = linkNum = 0; linkNum < NG_BRIDGE_MAX_LINKS; linkNum++) { 1027 struct ng_bridge_link *const link = priv->links[linkNum]; 1028 1029 if (link != NULL) { 1030 if (link->loopCount != 0) { 1031 link->loopCount--; 1032 if (link->loopCount == 0 1033 && priv->conf.debugLevel >= 2) { 1034 log(LOG_INFO, "ng_bridge: %s:" 1035 " restoring looped back link%d\n", 1036 ng_bridge_nodename(node), linkNum); 1037 } 1038 } 1039 counter++; 1040 } 1041 } 1042 KASSERT(priv->numLinks == counter, 1043 ("%s: links: %d != %d", __func__, priv->numLinks, counter)); 1044 1045 /* Done */ 1046 splx(s); 1047 } 1048 1049 /* 1050 * Return node's "name", even if it doesn't have one. 1051 */ 1052 static const char * 1053 ng_bridge_nodename(node_p node) 1054 { 1055 static char name[NG_NODESIZ]; 1056 1057 if (NG_NODE_NAME(node) != NULL) 1058 snprintf(name, sizeof(name), "%s", NG_NODE_NAME(node)); 1059 else 1060 snprintf(name, sizeof(name), "[%x]", ng_node2ID(node)); 1061 return name; 1062 } 1063 1064