1 /* 2 * ng_bridge.c 3 */ 4 5 /*- 6 * Copyright (c) 2000 Whistle Communications, Inc. 7 * All rights reserved. 8 * 9 * Subject to the following obligations and disclaimer of warranty, use and 10 * redistribution of this software, in source or object code forms, with or 11 * without modifications are expressly permitted by Whistle Communications; 12 * provided, however, that: 13 * 1. Any and all reproductions of the source or object code must include the 14 * copyright notice above and the following disclaimer of warranties; and 15 * 2. No rights are granted, in any manner or form, to use Whistle 16 * Communications, Inc. trademarks, including the mark "WHISTLE 17 * COMMUNICATIONS" on advertising, endorsements, or otherwise except as 18 * such appears in the above copyright notice or in the software. 19 * 20 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND 21 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO 22 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE, 23 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF 24 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. 25 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY 26 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS 27 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE. 28 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES 29 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING 30 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 31 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR 32 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY 33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 35 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY 36 * OF SUCH DAMAGE. 37 * 38 * Author: Archie Cobbs <archie@freebsd.org> 39 * 40 * $FreeBSD$ 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/lock.h> 65 #include <sys/malloc.h> 66 #include <sys/mbuf.h> 67 #include <sys/errno.h> 68 #include <sys/rwlock.h> 69 #include <sys/syslog.h> 70 #include <sys/socket.h> 71 #include <sys/ctype.h> 72 73 #include <net/if.h> 74 #include <net/ethernet.h> 75 #include <net/vnet.h> 76 77 #include <netinet/in.h> 78 #if 0 /* not used yet */ 79 #include <netinet/ip_fw.h> 80 #endif 81 #include <netgraph/ng_message.h> 82 #include <netgraph/netgraph.h> 83 #include <netgraph/ng_parse.h> 84 #include <netgraph/ng_bridge.h> 85 86 #ifdef NG_SEPARATE_MALLOC 87 MALLOC_DEFINE(M_NETGRAPH_BRIDGE, "netgraph_bridge", "netgraph bridge node "); 88 #else 89 #define M_NETGRAPH_BRIDGE M_NETGRAPH 90 #endif 91 92 /* Per-link private data */ 93 struct ng_bridge_link { 94 hook_p hook; /* netgraph hook */ 95 u_int16_t loopCount; /* loop ignore timer */ 96 struct ng_bridge_link_stats stats; /* link stats */ 97 }; 98 99 /* Per-node private data */ 100 struct ng_bridge_private { 101 struct ng_bridge_bucket *tab; /* hash table bucket array */ 102 struct ng_bridge_link *links[NG_BRIDGE_MAX_LINKS]; 103 struct ng_bridge_config conf; /* node configuration */ 104 node_p node; /* netgraph node */ 105 u_int numHosts; /* num entries in table */ 106 u_int numBuckets; /* num buckets in table */ 107 u_int hashMask; /* numBuckets - 1 */ 108 int numLinks; /* num connected links */ 109 struct callout timer; /* one second periodic timer */ 110 }; 111 typedef struct ng_bridge_private *priv_p; 112 113 /* Information about a host, stored in a hash table entry */ 114 struct ng_bridge_hent { 115 struct ng_bridge_host host; /* actual host info */ 116 SLIST_ENTRY(ng_bridge_hent) next; /* next entry in bucket */ 117 }; 118 119 /* Hash table bucket declaration */ 120 SLIST_HEAD(ng_bridge_bucket, ng_bridge_hent); 121 122 /* Netgraph node methods */ 123 static ng_constructor_t ng_bridge_constructor; 124 static ng_rcvmsg_t ng_bridge_rcvmsg; 125 static ng_shutdown_t ng_bridge_shutdown; 126 static ng_newhook_t ng_bridge_newhook; 127 static ng_rcvdata_t ng_bridge_rcvdata; 128 static ng_disconnect_t ng_bridge_disconnect; 129 130 /* Other internal functions */ 131 static struct ng_bridge_host *ng_bridge_get(priv_p priv, const u_char *addr); 132 static int ng_bridge_put(priv_p priv, const u_char *addr, int linkNum); 133 static void ng_bridge_rehash(priv_p priv); 134 static void ng_bridge_remove_hosts(priv_p priv, int linkNum); 135 static void ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2); 136 static const char *ng_bridge_nodename(node_p node); 137 138 /* Ethernet broadcast */ 139 static const u_char ng_bridge_bcast_addr[ETHER_ADDR_LEN] = 140 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; 141 142 /* Store each hook's link number in the private field */ 143 #define LINK_NUM(hook) (*(u_int16_t *)(&(hook)->private)) 144 145 /* Compare Ethernet addresses using 32 and 16 bit words instead of bytewise */ 146 #define ETHER_EQUAL(a,b) (((const u_int32_t *)(a))[0] \ 147 == ((const u_int32_t *)(b))[0] \ 148 && ((const u_int16_t *)(a))[2] \ 149 == ((const u_int16_t *)(b))[2]) 150 151 /* Minimum and maximum number of hash buckets. Must be a power of two. */ 152 #define MIN_BUCKETS (1 << 5) /* 32 */ 153 #define MAX_BUCKETS (1 << 14) /* 16384 */ 154 155 /* Configuration default values */ 156 #define DEFAULT_LOOP_TIMEOUT 60 157 #define DEFAULT_MAX_STALENESS (15 * 60) /* same as ARP timeout */ 158 #define DEFAULT_MIN_STABLE_AGE 1 159 160 /****************************************************************** 161 NETGRAPH PARSE TYPES 162 ******************************************************************/ 163 164 /* 165 * How to determine the length of the table returned by NGM_BRIDGE_GET_TABLE 166 */ 167 static int 168 ng_bridge_getTableLength(const struct ng_parse_type *type, 169 const u_char *start, const u_char *buf) 170 { 171 const struct ng_bridge_host_ary *const hary 172 = (const struct ng_bridge_host_ary *)(buf - sizeof(u_int32_t)); 173 174 return hary->numHosts; 175 } 176 177 /* Parse type for struct ng_bridge_host_ary */ 178 static const struct ng_parse_struct_field ng_bridge_host_type_fields[] 179 = NG_BRIDGE_HOST_TYPE_INFO(&ng_parse_enaddr_type); 180 static const struct ng_parse_type ng_bridge_host_type = { 181 &ng_parse_struct_type, 182 &ng_bridge_host_type_fields 183 }; 184 static const struct ng_parse_array_info ng_bridge_hary_type_info = { 185 &ng_bridge_host_type, 186 ng_bridge_getTableLength 187 }; 188 static const struct ng_parse_type ng_bridge_hary_type = { 189 &ng_parse_array_type, 190 &ng_bridge_hary_type_info 191 }; 192 static const struct ng_parse_struct_field ng_bridge_host_ary_type_fields[] 193 = NG_BRIDGE_HOST_ARY_TYPE_INFO(&ng_bridge_hary_type); 194 static const struct ng_parse_type ng_bridge_host_ary_type = { 195 &ng_parse_struct_type, 196 &ng_bridge_host_ary_type_fields 197 }; 198 199 /* Parse type for struct ng_bridge_config */ 200 static const struct ng_parse_fixedarray_info ng_bridge_ipfwary_type_info = { 201 &ng_parse_uint8_type, 202 NG_BRIDGE_MAX_LINKS 203 }; 204 static const struct ng_parse_type ng_bridge_ipfwary_type = { 205 &ng_parse_fixedarray_type, 206 &ng_bridge_ipfwary_type_info 207 }; 208 static const struct ng_parse_struct_field ng_bridge_config_type_fields[] 209 = NG_BRIDGE_CONFIG_TYPE_INFO(&ng_bridge_ipfwary_type); 210 static const struct ng_parse_type ng_bridge_config_type = { 211 &ng_parse_struct_type, 212 &ng_bridge_config_type_fields 213 }; 214 215 /* Parse type for struct ng_bridge_link_stat */ 216 static const struct ng_parse_struct_field ng_bridge_stats_type_fields[] 217 = NG_BRIDGE_STATS_TYPE_INFO; 218 static const struct ng_parse_type ng_bridge_stats_type = { 219 &ng_parse_struct_type, 220 &ng_bridge_stats_type_fields 221 }; 222 223 /* List of commands and how to convert arguments to/from ASCII */ 224 static const struct ng_cmdlist ng_bridge_cmdlist[] = { 225 { 226 NGM_BRIDGE_COOKIE, 227 NGM_BRIDGE_SET_CONFIG, 228 "setconfig", 229 &ng_bridge_config_type, 230 NULL 231 }, 232 { 233 NGM_BRIDGE_COOKIE, 234 NGM_BRIDGE_GET_CONFIG, 235 "getconfig", 236 NULL, 237 &ng_bridge_config_type 238 }, 239 { 240 NGM_BRIDGE_COOKIE, 241 NGM_BRIDGE_RESET, 242 "reset", 243 NULL, 244 NULL 245 }, 246 { 247 NGM_BRIDGE_COOKIE, 248 NGM_BRIDGE_GET_STATS, 249 "getstats", 250 &ng_parse_uint32_type, 251 &ng_bridge_stats_type 252 }, 253 { 254 NGM_BRIDGE_COOKIE, 255 NGM_BRIDGE_CLR_STATS, 256 "clrstats", 257 &ng_parse_uint32_type, 258 NULL 259 }, 260 { 261 NGM_BRIDGE_COOKIE, 262 NGM_BRIDGE_GETCLR_STATS, 263 "getclrstats", 264 &ng_parse_uint32_type, 265 &ng_bridge_stats_type 266 }, 267 { 268 NGM_BRIDGE_COOKIE, 269 NGM_BRIDGE_GET_TABLE, 270 "gettable", 271 NULL, 272 &ng_bridge_host_ary_type 273 }, 274 { 0 } 275 }; 276 277 /* Node type descriptor */ 278 static struct ng_type ng_bridge_typestruct = { 279 .version = NG_ABI_VERSION, 280 .name = NG_BRIDGE_NODE_TYPE, 281 .constructor = ng_bridge_constructor, 282 .rcvmsg = ng_bridge_rcvmsg, 283 .shutdown = ng_bridge_shutdown, 284 .newhook = ng_bridge_newhook, 285 .rcvdata = ng_bridge_rcvdata, 286 .disconnect = ng_bridge_disconnect, 287 .cmdlist = ng_bridge_cmdlist, 288 }; 289 NETGRAPH_INIT(bridge, &ng_bridge_typestruct); 290 291 /****************************************************************** 292 NETGRAPH NODE METHODS 293 ******************************************************************/ 294 295 /* 296 * Node constructor 297 */ 298 static int 299 ng_bridge_constructor(node_p node) 300 { 301 priv_p priv; 302 303 /* Allocate and initialize private info */ 304 priv = malloc(sizeof(*priv), M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO); 305 if (priv == NULL) 306 return (ENOMEM); 307 ng_callout_init(&priv->timer); 308 309 /* Allocate and initialize hash table, etc. */ 310 priv->tab = malloc(MIN_BUCKETS * sizeof(*priv->tab), 311 M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO); 312 if (priv->tab == NULL) { 313 free(priv, M_NETGRAPH_BRIDGE); 314 return (ENOMEM); 315 } 316 priv->numBuckets = MIN_BUCKETS; 317 priv->hashMask = MIN_BUCKETS - 1; 318 priv->conf.debugLevel = 1; 319 priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT; 320 priv->conf.maxStaleness = DEFAULT_MAX_STALENESS; 321 priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE; 322 323 /* 324 * This node has all kinds of stuff that could be screwed by SMP. 325 * Until it gets it's own internal protection, we go through in 326 * single file. This could hurt a machine bridging beteen two 327 * GB ethernets so it should be fixed. 328 * When it's fixed the process SHOULD NOT SLEEP, spinlocks please! 329 * (and atomic ops ) 330 */ 331 NG_NODE_FORCE_WRITER(node); 332 NG_NODE_SET_PRIVATE(node, priv); 333 priv->node = node; 334 335 /* Start timer; timer is always running while node is alive */ 336 ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0); 337 338 /* Done */ 339 return (0); 340 } 341 342 /* 343 * Method for attaching a new hook 344 */ 345 static int 346 ng_bridge_newhook(node_p node, hook_p hook, const char *name) 347 { 348 const priv_p priv = NG_NODE_PRIVATE(node); 349 350 /* Check for a link hook */ 351 if (strncmp(name, NG_BRIDGE_HOOK_LINK_PREFIX, 352 strlen(NG_BRIDGE_HOOK_LINK_PREFIX)) == 0) { 353 const char *cp; 354 char *eptr; 355 u_long linkNum; 356 357 cp = name + strlen(NG_BRIDGE_HOOK_LINK_PREFIX); 358 if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0')) 359 return (EINVAL); 360 linkNum = strtoul(cp, &eptr, 10); 361 if (*eptr != '\0' || linkNum >= NG_BRIDGE_MAX_LINKS) 362 return (EINVAL); 363 if (priv->links[linkNum] != NULL) 364 return (EISCONN); 365 priv->links[linkNum] = malloc(sizeof(*priv->links[linkNum]), 366 M_NETGRAPH_BRIDGE, M_NOWAIT|M_ZERO); 367 if (priv->links[linkNum] == NULL) 368 return (ENOMEM); 369 priv->links[linkNum]->hook = hook; 370 NG_HOOK_SET_PRIVATE(hook, (void *)linkNum); 371 priv->numLinks++; 372 return (0); 373 } 374 375 /* Unknown hook name */ 376 return (EINVAL); 377 } 378 379 /* 380 * Receive a control message 381 */ 382 static int 383 ng_bridge_rcvmsg(node_p node, item_p item, hook_p lasthook) 384 { 385 const priv_p priv = NG_NODE_PRIVATE(node); 386 struct ng_mesg *resp = NULL; 387 int error = 0; 388 struct ng_mesg *msg; 389 390 NGI_GET_MSG(item, msg); 391 switch (msg->header.typecookie) { 392 case NGM_BRIDGE_COOKIE: 393 switch (msg->header.cmd) { 394 case NGM_BRIDGE_GET_CONFIG: 395 { 396 struct ng_bridge_config *conf; 397 398 NG_MKRESPONSE(resp, msg, 399 sizeof(struct ng_bridge_config), M_NOWAIT); 400 if (resp == NULL) { 401 error = ENOMEM; 402 break; 403 } 404 conf = (struct ng_bridge_config *)resp->data; 405 *conf = priv->conf; /* no sanity checking needed */ 406 break; 407 } 408 case NGM_BRIDGE_SET_CONFIG: 409 { 410 struct ng_bridge_config *conf; 411 int i; 412 413 if (msg->header.arglen 414 != sizeof(struct ng_bridge_config)) { 415 error = EINVAL; 416 break; 417 } 418 conf = (struct ng_bridge_config *)msg->data; 419 priv->conf = *conf; 420 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) 421 priv->conf.ipfw[i] = !!priv->conf.ipfw[i]; 422 break; 423 } 424 case NGM_BRIDGE_RESET: 425 { 426 int i; 427 428 /* Flush all entries in the hash table */ 429 ng_bridge_remove_hosts(priv, -1); 430 431 /* Reset all loop detection counters and stats */ 432 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) { 433 if (priv->links[i] == NULL) 434 continue; 435 priv->links[i]->loopCount = 0; 436 bzero(&priv->links[i]->stats, 437 sizeof(priv->links[i]->stats)); 438 } 439 break; 440 } 441 case NGM_BRIDGE_GET_STATS: 442 case NGM_BRIDGE_CLR_STATS: 443 case NGM_BRIDGE_GETCLR_STATS: 444 { 445 struct ng_bridge_link *link; 446 int linkNum; 447 448 /* Get link number */ 449 if (msg->header.arglen != sizeof(u_int32_t)) { 450 error = EINVAL; 451 break; 452 } 453 linkNum = *((u_int32_t *)msg->data); 454 if (linkNum < 0 || linkNum >= NG_BRIDGE_MAX_LINKS) { 455 error = EINVAL; 456 break; 457 } 458 if ((link = priv->links[linkNum]) == NULL) { 459 error = ENOTCONN; 460 break; 461 } 462 463 /* Get/clear stats */ 464 if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) { 465 NG_MKRESPONSE(resp, msg, 466 sizeof(link->stats), M_NOWAIT); 467 if (resp == NULL) { 468 error = ENOMEM; 469 break; 470 } 471 bcopy(&link->stats, 472 resp->data, sizeof(link->stats)); 473 } 474 if (msg->header.cmd != NGM_BRIDGE_GET_STATS) 475 bzero(&link->stats, sizeof(link->stats)); 476 break; 477 } 478 case NGM_BRIDGE_GET_TABLE: 479 { 480 struct ng_bridge_host_ary *ary; 481 struct ng_bridge_hent *hent; 482 int i = 0, bucket; 483 484 NG_MKRESPONSE(resp, msg, sizeof(*ary) 485 + (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT); 486 if (resp == NULL) { 487 error = ENOMEM; 488 break; 489 } 490 ary = (struct ng_bridge_host_ary *)resp->data; 491 ary->numHosts = priv->numHosts; 492 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 493 SLIST_FOREACH(hent, &priv->tab[bucket], next) 494 ary->hosts[i++] = hent->host; 495 } 496 break; 497 } 498 default: 499 error = EINVAL; 500 break; 501 } 502 break; 503 default: 504 error = EINVAL; 505 break; 506 } 507 508 /* Done */ 509 NG_RESPOND_MSG(error, node, item, resp); 510 NG_FREE_MSG(msg); 511 return (error); 512 } 513 514 /* 515 * Receive data on a hook 516 */ 517 static int 518 ng_bridge_rcvdata(hook_p hook, item_p item) 519 { 520 const node_p node = NG_HOOK_NODE(hook); 521 const priv_p priv = NG_NODE_PRIVATE(node); 522 struct ng_bridge_host *host; 523 struct ng_bridge_link *link; 524 struct ether_header *eh; 525 int error = 0, linkNum, linksSeen; 526 int manycast; 527 struct mbuf *m; 528 struct ng_bridge_link *firstLink; 529 530 NGI_GET_M(item, m); 531 /* Get link number */ 532 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook); 533 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 534 ("%s: linkNum=%u", __func__, linkNum)); 535 link = priv->links[linkNum]; 536 KASSERT(link != NULL, ("%s: link%d null", __func__, linkNum)); 537 538 /* Sanity check packet and pull up header */ 539 if (m->m_pkthdr.len < ETHER_HDR_LEN) { 540 link->stats.recvRunts++; 541 NG_FREE_ITEM(item); 542 NG_FREE_M(m); 543 return (EINVAL); 544 } 545 if (m->m_len < ETHER_HDR_LEN && !(m = m_pullup(m, ETHER_HDR_LEN))) { 546 link->stats.memoryFailures++; 547 NG_FREE_ITEM(item); 548 return (ENOBUFS); 549 } 550 eh = mtod(m, struct ether_header *); 551 if ((eh->ether_shost[0] & 1) != 0) { 552 link->stats.recvInvalid++; 553 NG_FREE_ITEM(item); 554 NG_FREE_M(m); 555 return (EINVAL); 556 } 557 558 /* Is link disabled due to a loopback condition? */ 559 if (link->loopCount != 0) { 560 link->stats.loopDrops++; 561 NG_FREE_ITEM(item); 562 NG_FREE_M(m); 563 return (ELOOP); /* XXX is this an appropriate error? */ 564 } 565 566 /* Update stats */ 567 link->stats.recvPackets++; 568 link->stats.recvOctets += m->m_pkthdr.len; 569 if ((manycast = (eh->ether_dhost[0] & 1)) != 0) { 570 if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) { 571 link->stats.recvBroadcasts++; 572 manycast = 2; 573 } else 574 link->stats.recvMulticasts++; 575 } 576 577 /* Look up packet's source Ethernet address in hashtable */ 578 if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) { 579 580 /* Update time since last heard from this host */ 581 host->staleness = 0; 582 583 /* Did host jump to a different link? */ 584 if (host->linkNum != linkNum) { 585 586 /* 587 * If the host's old link was recently established 588 * on the old link and it's already jumped to a new 589 * link, declare a loopback condition. 590 */ 591 if (host->age < priv->conf.minStableAge) { 592 593 /* Log the problem */ 594 if (priv->conf.debugLevel >= 2) { 595 struct ifnet *ifp = m->m_pkthdr.rcvif; 596 char suffix[32]; 597 598 if (ifp != NULL) 599 snprintf(suffix, sizeof(suffix), 600 " (%s)", ifp->if_xname); 601 else 602 *suffix = '\0'; 603 log(LOG_WARNING, "ng_bridge: %s:" 604 " loopback detected on %s%s\n", 605 ng_bridge_nodename(node), 606 NG_HOOK_NAME(hook), suffix); 607 } 608 609 /* Mark link as linka non grata */ 610 link->loopCount = priv->conf.loopTimeout; 611 link->stats.loopDetects++; 612 613 /* Forget all hosts on this link */ 614 ng_bridge_remove_hosts(priv, linkNum); 615 616 /* Drop packet */ 617 link->stats.loopDrops++; 618 NG_FREE_ITEM(item); 619 NG_FREE_M(m); 620 return (ELOOP); /* XXX appropriate? */ 621 } 622 623 /* Move host over to new link */ 624 host->linkNum = linkNum; 625 host->age = 0; 626 } 627 } else { 628 if (!ng_bridge_put(priv, eh->ether_shost, linkNum)) { 629 link->stats.memoryFailures++; 630 NG_FREE_ITEM(item); 631 NG_FREE_M(m); 632 return (ENOMEM); 633 } 634 } 635 636 /* Run packet through ipfw processing, if enabled */ 637 #if 0 638 if (priv->conf.ipfw[linkNum] && V_fw_enable && V_ip_fw_chk_ptr != NULL) { 639 /* XXX not implemented yet */ 640 } 641 #endif 642 643 /* 644 * If unicast and destination host known, deliver to host's link, 645 * unless it is the same link as the packet came in on. 646 */ 647 if (!manycast) { 648 649 /* Determine packet destination link */ 650 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) { 651 struct ng_bridge_link *const destLink 652 = priv->links[host->linkNum]; 653 654 /* If destination same as incoming link, do nothing */ 655 KASSERT(destLink != NULL, 656 ("%s: link%d null", __func__, host->linkNum)); 657 if (destLink == link) { 658 NG_FREE_ITEM(item); 659 NG_FREE_M(m); 660 return (0); 661 } 662 663 /* Deliver packet out the destination link */ 664 destLink->stats.xmitPackets++; 665 destLink->stats.xmitOctets += m->m_pkthdr.len; 666 NG_FWD_NEW_DATA(error, item, destLink->hook, m); 667 return (error); 668 } 669 670 /* Destination host is not known */ 671 link->stats.recvUnknown++; 672 } 673 674 /* Distribute unknown, multicast, broadcast pkts to all other links */ 675 firstLink = NULL; 676 for (linkNum = linksSeen = 0; linksSeen <= priv->numLinks; linkNum++) { 677 struct ng_bridge_link *destLink; 678 struct mbuf *m2 = NULL; 679 680 /* 681 * If we have checked all the links then now 682 * send the original on its reserved link 683 */ 684 if (linksSeen == priv->numLinks) { 685 /* If we never saw a good link, leave. */ 686 if (firstLink == NULL) { 687 NG_FREE_ITEM(item); 688 NG_FREE_M(m); 689 return (0); 690 } 691 destLink = firstLink; 692 } else { 693 destLink = priv->links[linkNum]; 694 if (destLink != NULL) 695 linksSeen++; 696 /* Skip incoming link and disconnected links */ 697 if (destLink == NULL || destLink == link) { 698 continue; 699 } 700 if (firstLink == NULL) { 701 /* 702 * This is the first usable link we have found. 703 * Reserve it for the originals. 704 * If we never find another we save a copy. 705 */ 706 firstLink = destLink; 707 continue; 708 } 709 710 /* 711 * It's usable link but not the reserved (first) one. 712 * Copy mbuf info for sending. 713 */ 714 m2 = m_dup(m, M_DONTWAIT); /* XXX m_copypacket() */ 715 if (m2 == NULL) { 716 link->stats.memoryFailures++; 717 NG_FREE_ITEM(item); 718 NG_FREE_M(m); 719 return (ENOBUFS); 720 } 721 } 722 723 /* Update stats */ 724 destLink->stats.xmitPackets++; 725 destLink->stats.xmitOctets += m->m_pkthdr.len; 726 switch (manycast) { 727 case 0: /* unicast */ 728 break; 729 case 1: /* multicast */ 730 destLink->stats.xmitMulticasts++; 731 break; 732 case 2: /* broadcast */ 733 destLink->stats.xmitBroadcasts++; 734 break; 735 } 736 737 /* Send packet */ 738 if (destLink == firstLink) { 739 /* 740 * If we've sent all the others, send the original 741 * on the first link we found. 742 */ 743 NG_FWD_NEW_DATA(error, item, destLink->hook, m); 744 break; /* always done last - not really needed. */ 745 } else { 746 NG_SEND_DATA_ONLY(error, destLink->hook, m2); 747 } 748 } 749 return (error); 750 } 751 752 /* 753 * Shutdown node 754 */ 755 static int 756 ng_bridge_shutdown(node_p node) 757 { 758 const priv_p priv = NG_NODE_PRIVATE(node); 759 760 /* 761 * Shut down everything including the timer. Even if the 762 * callout has already been dequeued and is about to be 763 * run, ng_bridge_timeout() won't be fired as the node 764 * is already marked NGF_INVALID, so we're safe to free 765 * the node now. 766 */ 767 KASSERT(priv->numLinks == 0 && priv->numHosts == 0, 768 ("%s: numLinks=%d numHosts=%d", 769 __func__, priv->numLinks, priv->numHosts)); 770 ng_uncallout(&priv->timer, node); 771 NG_NODE_SET_PRIVATE(node, NULL); 772 NG_NODE_UNREF(node); 773 free(priv->tab, M_NETGRAPH_BRIDGE); 774 free(priv, M_NETGRAPH_BRIDGE); 775 return (0); 776 } 777 778 /* 779 * Hook disconnection. 780 */ 781 static int 782 ng_bridge_disconnect(hook_p hook) 783 { 784 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); 785 int linkNum; 786 787 /* Get link number */ 788 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook); 789 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 790 ("%s: linkNum=%u", __func__, linkNum)); 791 792 /* Remove all hosts associated with this link */ 793 ng_bridge_remove_hosts(priv, linkNum); 794 795 /* Free associated link information */ 796 KASSERT(priv->links[linkNum] != NULL, ("%s: no link", __func__)); 797 free(priv->links[linkNum], M_NETGRAPH_BRIDGE); 798 priv->links[linkNum] = NULL; 799 priv->numLinks--; 800 801 /* If no more hooks, go away */ 802 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) 803 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) { 804 ng_rmnode_self(NG_HOOK_NODE(hook)); 805 } 806 return (0); 807 } 808 809 /****************************************************************** 810 HASH TABLE FUNCTIONS 811 ******************************************************************/ 812 813 /* 814 * Hash algorithm 815 */ 816 #define HASH(addr,mask) ( (((const u_int16_t *)(addr))[0] \ 817 ^ ((const u_int16_t *)(addr))[1] \ 818 ^ ((const u_int16_t *)(addr))[2]) & (mask) ) 819 820 /* 821 * Find a host entry in the table. 822 */ 823 static struct ng_bridge_host * 824 ng_bridge_get(priv_p priv, const u_char *addr) 825 { 826 const int bucket = HASH(addr, priv->hashMask); 827 struct ng_bridge_hent *hent; 828 829 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 830 if (ETHER_EQUAL(hent->host.addr, addr)) 831 return (&hent->host); 832 } 833 return (NULL); 834 } 835 836 /* 837 * Add a new host entry to the table. This assumes the host doesn't 838 * already exist in the table. Returns 1 on success, 0 if there 839 * was a memory allocation failure. 840 */ 841 static int 842 ng_bridge_put(priv_p priv, const u_char *addr, int linkNum) 843 { 844 const int bucket = HASH(addr, priv->hashMask); 845 struct ng_bridge_hent *hent; 846 847 #ifdef INVARIANTS 848 /* Assert that entry does not already exist in hashtable */ 849 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 850 KASSERT(!ETHER_EQUAL(hent->host.addr, addr), 851 ("%s: entry %6D exists in table", __func__, addr, ":")); 852 } 853 #endif 854 855 /* Allocate and initialize new hashtable entry */ 856 hent = malloc(sizeof(*hent), M_NETGRAPH_BRIDGE, M_NOWAIT); 857 if (hent == NULL) 858 return (0); 859 bcopy(addr, hent->host.addr, ETHER_ADDR_LEN); 860 hent->host.linkNum = linkNum; 861 hent->host.staleness = 0; 862 hent->host.age = 0; 863 864 /* Add new element to hash bucket */ 865 SLIST_INSERT_HEAD(&priv->tab[bucket], hent, next); 866 priv->numHosts++; 867 868 /* Resize table if necessary */ 869 ng_bridge_rehash(priv); 870 return (1); 871 } 872 873 /* 874 * Resize the hash table. We try to maintain the number of buckets 875 * such that the load factor is in the range 0.25 to 1.0. 876 * 877 * If we can't get the new memory then we silently fail. This is OK 878 * because things will still work and we'll try again soon anyway. 879 */ 880 static void 881 ng_bridge_rehash(priv_p priv) 882 { 883 struct ng_bridge_bucket *newTab; 884 int oldBucket, newBucket; 885 int newNumBuckets; 886 u_int newMask; 887 888 /* Is table too full or too empty? */ 889 if (priv->numHosts > priv->numBuckets 890 && (priv->numBuckets << 1) <= MAX_BUCKETS) 891 newNumBuckets = priv->numBuckets << 1; 892 else if (priv->numHosts < (priv->numBuckets >> 2) 893 && (priv->numBuckets >> 2) >= MIN_BUCKETS) 894 newNumBuckets = priv->numBuckets >> 2; 895 else 896 return; 897 newMask = newNumBuckets - 1; 898 899 /* Allocate and initialize new table */ 900 newTab = malloc(newNumBuckets * sizeof(*newTab), 901 M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO); 902 if (newTab == NULL) 903 return; 904 905 /* Move all entries from old table to new table */ 906 for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) { 907 struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket]; 908 909 while (!SLIST_EMPTY(oldList)) { 910 struct ng_bridge_hent *const hent 911 = SLIST_FIRST(oldList); 912 913 SLIST_REMOVE_HEAD(oldList, next); 914 newBucket = HASH(hent->host.addr, newMask); 915 SLIST_INSERT_HEAD(&newTab[newBucket], hent, next); 916 } 917 } 918 919 /* Replace old table with new one */ 920 if (priv->conf.debugLevel >= 3) { 921 log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n", 922 ng_bridge_nodename(priv->node), 923 priv->numBuckets, newNumBuckets); 924 } 925 free(priv->tab, M_NETGRAPH_BRIDGE); 926 priv->numBuckets = newNumBuckets; 927 priv->hashMask = newMask; 928 priv->tab = newTab; 929 return; 930 } 931 932 /****************************************************************** 933 MISC FUNCTIONS 934 ******************************************************************/ 935 936 /* 937 * Remove all hosts associated with a specific link from the hashtable. 938 * If linkNum == -1, then remove all hosts in the table. 939 */ 940 static void 941 ng_bridge_remove_hosts(priv_p priv, int linkNum) 942 { 943 int bucket; 944 945 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 946 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 947 948 while (*hptr != NULL) { 949 struct ng_bridge_hent *const hent = *hptr; 950 951 if (linkNum == -1 || hent->host.linkNum == linkNum) { 952 *hptr = SLIST_NEXT(hent, next); 953 free(hent, M_NETGRAPH_BRIDGE); 954 priv->numHosts--; 955 } else 956 hptr = &SLIST_NEXT(hent, next); 957 } 958 } 959 } 960 961 /* 962 * Handle our once-per-second timeout event. We do two things: 963 * we decrement link->loopCount for those links being muted due to 964 * a detected loopback condition, and we remove any hosts from 965 * the hashtable whom we haven't heard from in a long while. 966 */ 967 static void 968 ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2) 969 { 970 const priv_p priv = NG_NODE_PRIVATE(node); 971 int bucket; 972 int counter = 0; 973 int linkNum; 974 975 /* Update host time counters and remove stale entries */ 976 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 977 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 978 979 while (*hptr != NULL) { 980 struct ng_bridge_hent *const hent = *hptr; 981 982 /* Make sure host's link really exists */ 983 KASSERT(priv->links[hent->host.linkNum] != NULL, 984 ("%s: host %6D on nonexistent link %d\n", 985 __func__, hent->host.addr, ":", 986 hent->host.linkNum)); 987 988 /* Remove hosts we haven't heard from in a while */ 989 if (++hent->host.staleness >= priv->conf.maxStaleness) { 990 *hptr = SLIST_NEXT(hent, next); 991 free(hent, M_NETGRAPH_BRIDGE); 992 priv->numHosts--; 993 } else { 994 if (hent->host.age < 0xffff) 995 hent->host.age++; 996 hptr = &SLIST_NEXT(hent, next); 997 counter++; 998 } 999 } 1000 } 1001 KASSERT(priv->numHosts == counter, 1002 ("%s: hosts: %d != %d", __func__, priv->numHosts, counter)); 1003 1004 /* Decrease table size if necessary */ 1005 ng_bridge_rehash(priv); 1006 1007 /* Decrease loop counter on muted looped back links */ 1008 for (counter = linkNum = 0; linkNum < NG_BRIDGE_MAX_LINKS; linkNum++) { 1009 struct ng_bridge_link *const link = priv->links[linkNum]; 1010 1011 if (link != NULL) { 1012 if (link->loopCount != 0) { 1013 link->loopCount--; 1014 if (link->loopCount == 0 1015 && priv->conf.debugLevel >= 2) { 1016 log(LOG_INFO, "ng_bridge: %s:" 1017 " restoring looped back link%d\n", 1018 ng_bridge_nodename(node), linkNum); 1019 } 1020 } 1021 counter++; 1022 } 1023 } 1024 KASSERT(priv->numLinks == counter, 1025 ("%s: links: %d != %d", __func__, priv->numLinks, counter)); 1026 1027 /* Register a new timeout, keeping the existing node reference */ 1028 ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0); 1029 } 1030 1031 /* 1032 * Return node's "name", even if it doesn't have one. 1033 */ 1034 static const char * 1035 ng_bridge_nodename(node_p node) 1036 { 1037 static char name[NG_NODESIZ]; 1038 1039 if (NG_NODE_NAME(node) != NULL) 1040 snprintf(name, sizeof(name), "%s", NG_NODE_NAME(node)); 1041 else 1042 snprintf(name, sizeof(name), "[%x]", ng_node2ID(node)); 1043 return name; 1044 } 1045 1046