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 #include <netinet/ip_fw.h> 79 80 #include <netgraph/ng_message.h> 81 #include <netgraph/netgraph.h> 82 #include <netgraph/ng_parse.h> 83 #include <netgraph/ng_bridge.h> 84 85 #ifdef NG_SEPARATE_MALLOC 86 MALLOC_DEFINE(M_NETGRAPH_BRIDGE, "netgraph_bridge", "netgraph bridge node "); 87 #else 88 #define M_NETGRAPH_BRIDGE M_NETGRAPH 89 #endif 90 91 /* Per-link private data */ 92 struct ng_bridge_link { 93 hook_p hook; /* netgraph hook */ 94 u_int16_t loopCount; /* loop ignore timer */ 95 struct ng_bridge_link_stats stats; /* link stats */ 96 }; 97 98 /* Per-node private data */ 99 struct ng_bridge_private { 100 struct ng_bridge_bucket *tab; /* hash table bucket array */ 101 struct ng_bridge_link *links[NG_BRIDGE_MAX_LINKS]; 102 struct ng_bridge_config conf; /* node configuration */ 103 node_p node; /* netgraph node */ 104 u_int numHosts; /* num entries in table */ 105 u_int numBuckets; /* num buckets in table */ 106 u_int hashMask; /* numBuckets - 1 */ 107 int numLinks; /* num connected links */ 108 struct callout timer; /* one second periodic timer */ 109 }; 110 typedef struct ng_bridge_private *priv_p; 111 112 /* Information about a host, stored in a hash table entry */ 113 struct ng_bridge_hent { 114 struct ng_bridge_host host; /* actual host info */ 115 SLIST_ENTRY(ng_bridge_hent) next; /* next entry in bucket */ 116 }; 117 118 /* Hash table bucket declaration */ 119 SLIST_HEAD(ng_bridge_bucket, ng_bridge_hent); 120 121 /* Netgraph node methods */ 122 static ng_constructor_t ng_bridge_constructor; 123 static ng_rcvmsg_t ng_bridge_rcvmsg; 124 static ng_shutdown_t ng_bridge_shutdown; 125 static ng_newhook_t ng_bridge_newhook; 126 static ng_rcvdata_t ng_bridge_rcvdata; 127 static ng_disconnect_t ng_bridge_disconnect; 128 129 /* Other internal functions */ 130 static struct ng_bridge_host *ng_bridge_get(priv_p priv, const u_char *addr); 131 static int ng_bridge_put(priv_p priv, const u_char *addr, int linkNum); 132 static void ng_bridge_rehash(priv_p priv); 133 static void ng_bridge_remove_hosts(priv_p priv, int linkNum); 134 static void ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2); 135 static const char *ng_bridge_nodename(node_p node); 136 137 /* Ethernet broadcast */ 138 static const u_char ng_bridge_bcast_addr[ETHER_ADDR_LEN] = 139 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; 140 141 /* Store each hook's link number in the private field */ 142 #define LINK_NUM(hook) (*(u_int16_t *)(&(hook)->private)) 143 144 /* Compare Ethernet addresses using 32 and 16 bit words instead of bytewise */ 145 #define ETHER_EQUAL(a,b) (((const u_int32_t *)(a))[0] \ 146 == ((const u_int32_t *)(b))[0] \ 147 && ((const u_int16_t *)(a))[2] \ 148 == ((const u_int16_t *)(b))[2]) 149 150 /* Minimum and maximum number of hash buckets. Must be a power of two. */ 151 #define MIN_BUCKETS (1 << 5) /* 32 */ 152 #define MAX_BUCKETS (1 << 14) /* 16384 */ 153 154 /* Configuration default values */ 155 #define DEFAULT_LOOP_TIMEOUT 60 156 #define DEFAULT_MAX_STALENESS (15 * 60) /* same as ARP timeout */ 157 #define DEFAULT_MIN_STABLE_AGE 1 158 159 /****************************************************************** 160 NETGRAPH PARSE TYPES 161 ******************************************************************/ 162 163 /* 164 * How to determine the length of the table returned by NGM_BRIDGE_GET_TABLE 165 */ 166 static int 167 ng_bridge_getTableLength(const struct ng_parse_type *type, 168 const u_char *start, const u_char *buf) 169 { 170 const struct ng_bridge_host_ary *const hary 171 = (const struct ng_bridge_host_ary *)(buf - sizeof(u_int32_t)); 172 173 return hary->numHosts; 174 } 175 176 /* Parse type for struct ng_bridge_host_ary */ 177 static const struct ng_parse_struct_field ng_bridge_host_type_fields[] 178 = NG_BRIDGE_HOST_TYPE_INFO(&ng_parse_enaddr_type); 179 static const struct ng_parse_type ng_bridge_host_type = { 180 &ng_parse_struct_type, 181 &ng_bridge_host_type_fields 182 }; 183 static const struct ng_parse_array_info ng_bridge_hary_type_info = { 184 &ng_bridge_host_type, 185 ng_bridge_getTableLength 186 }; 187 static const struct ng_parse_type ng_bridge_hary_type = { 188 &ng_parse_array_type, 189 &ng_bridge_hary_type_info 190 }; 191 static const struct ng_parse_struct_field ng_bridge_host_ary_type_fields[] 192 = NG_BRIDGE_HOST_ARY_TYPE_INFO(&ng_bridge_hary_type); 193 static const struct ng_parse_type ng_bridge_host_ary_type = { 194 &ng_parse_struct_type, 195 &ng_bridge_host_ary_type_fields 196 }; 197 198 /* Parse type for struct ng_bridge_config */ 199 static const struct ng_parse_fixedarray_info ng_bridge_ipfwary_type_info = { 200 &ng_parse_uint8_type, 201 NG_BRIDGE_MAX_LINKS 202 }; 203 static const struct ng_parse_type ng_bridge_ipfwary_type = { 204 &ng_parse_fixedarray_type, 205 &ng_bridge_ipfwary_type_info 206 }; 207 static const struct ng_parse_struct_field ng_bridge_config_type_fields[] 208 = NG_BRIDGE_CONFIG_TYPE_INFO(&ng_bridge_ipfwary_type); 209 static const struct ng_parse_type ng_bridge_config_type = { 210 &ng_parse_struct_type, 211 &ng_bridge_config_type_fields 212 }; 213 214 /* Parse type for struct ng_bridge_link_stat */ 215 static const struct ng_parse_struct_field ng_bridge_stats_type_fields[] 216 = NG_BRIDGE_STATS_TYPE_INFO; 217 static const struct ng_parse_type ng_bridge_stats_type = { 218 &ng_parse_struct_type, 219 &ng_bridge_stats_type_fields 220 }; 221 222 /* List of commands and how to convert arguments to/from ASCII */ 223 static const struct ng_cmdlist ng_bridge_cmdlist[] = { 224 { 225 NGM_BRIDGE_COOKIE, 226 NGM_BRIDGE_SET_CONFIG, 227 "setconfig", 228 &ng_bridge_config_type, 229 NULL 230 }, 231 { 232 NGM_BRIDGE_COOKIE, 233 NGM_BRIDGE_GET_CONFIG, 234 "getconfig", 235 NULL, 236 &ng_bridge_config_type 237 }, 238 { 239 NGM_BRIDGE_COOKIE, 240 NGM_BRIDGE_RESET, 241 "reset", 242 NULL, 243 NULL 244 }, 245 { 246 NGM_BRIDGE_COOKIE, 247 NGM_BRIDGE_GET_STATS, 248 "getstats", 249 &ng_parse_uint32_type, 250 &ng_bridge_stats_type 251 }, 252 { 253 NGM_BRIDGE_COOKIE, 254 NGM_BRIDGE_CLR_STATS, 255 "clrstats", 256 &ng_parse_uint32_type, 257 NULL 258 }, 259 { 260 NGM_BRIDGE_COOKIE, 261 NGM_BRIDGE_GETCLR_STATS, 262 "getclrstats", 263 &ng_parse_uint32_type, 264 &ng_bridge_stats_type 265 }, 266 { 267 NGM_BRIDGE_COOKIE, 268 NGM_BRIDGE_GET_TABLE, 269 "gettable", 270 NULL, 271 &ng_bridge_host_ary_type 272 }, 273 { 0 } 274 }; 275 276 /* Node type descriptor */ 277 static struct ng_type ng_bridge_typestruct = { 278 .version = NG_ABI_VERSION, 279 .name = NG_BRIDGE_NODE_TYPE, 280 .constructor = ng_bridge_constructor, 281 .rcvmsg = ng_bridge_rcvmsg, 282 .shutdown = ng_bridge_shutdown, 283 .newhook = ng_bridge_newhook, 284 .rcvdata = ng_bridge_rcvdata, 285 .disconnect = ng_bridge_disconnect, 286 .cmdlist = ng_bridge_cmdlist, 287 }; 288 NETGRAPH_INIT(bridge, &ng_bridge_typestruct); 289 290 /****************************************************************** 291 NETGRAPH NODE METHODS 292 ******************************************************************/ 293 294 /* 295 * Node constructor 296 */ 297 static int 298 ng_bridge_constructor(node_p node) 299 { 300 priv_p priv; 301 302 /* Allocate and initialize private info */ 303 priv = malloc(sizeof(*priv), M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO); 304 if (priv == NULL) 305 return (ENOMEM); 306 ng_callout_init(&priv->timer); 307 308 /* Allocate and initialize hash table, etc. */ 309 priv->tab = malloc(MIN_BUCKETS * sizeof(*priv->tab), 310 M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO); 311 if (priv->tab == NULL) { 312 free(priv, M_NETGRAPH_BRIDGE); 313 return (ENOMEM); 314 } 315 priv->numBuckets = MIN_BUCKETS; 316 priv->hashMask = MIN_BUCKETS - 1; 317 priv->conf.debugLevel = 1; 318 priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT; 319 priv->conf.maxStaleness = DEFAULT_MAX_STALENESS; 320 priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE; 321 322 /* 323 * This node has all kinds of stuff that could be screwed by SMP. 324 * Until it gets it's own internal protection, we go through in 325 * single file. This could hurt a machine bridging beteen two 326 * GB ethernets so it should be fixed. 327 * When it's fixed the process SHOULD NOT SLEEP, spinlocks please! 328 * (and atomic ops ) 329 */ 330 NG_NODE_FORCE_WRITER(node); 331 NG_NODE_SET_PRIVATE(node, priv); 332 priv->node = node; 333 334 /* Start timer; timer is always running while node is alive */ 335 ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0); 336 337 /* Done */ 338 return (0); 339 } 340 341 /* 342 * Method for attaching a new hook 343 */ 344 static int 345 ng_bridge_newhook(node_p node, hook_p hook, const char *name) 346 { 347 const priv_p priv = NG_NODE_PRIVATE(node); 348 349 /* Check for a link hook */ 350 if (strncmp(name, NG_BRIDGE_HOOK_LINK_PREFIX, 351 strlen(NG_BRIDGE_HOOK_LINK_PREFIX)) == 0) { 352 const char *cp; 353 char *eptr; 354 u_long linkNum; 355 356 cp = name + strlen(NG_BRIDGE_HOOK_LINK_PREFIX); 357 if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0')) 358 return (EINVAL); 359 linkNum = strtoul(cp, &eptr, 10); 360 if (*eptr != '\0' || linkNum >= NG_BRIDGE_MAX_LINKS) 361 return (EINVAL); 362 if (priv->links[linkNum] != NULL) 363 return (EISCONN); 364 priv->links[linkNum] = malloc(sizeof(*priv->links[linkNum]), 365 M_NETGRAPH_BRIDGE, M_NOWAIT|M_ZERO); 366 if (priv->links[linkNum] == NULL) 367 return (ENOMEM); 368 priv->links[linkNum]->hook = hook; 369 NG_HOOK_SET_PRIVATE(hook, (void *)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, item_p item, hook_p lasthook) 383 { 384 const priv_p priv = NG_NODE_PRIVATE(node); 385 struct ng_mesg *resp = NULL; 386 int error = 0; 387 struct ng_mesg *msg; 388 389 NGI_GET_MSG(item, msg); 390 switch (msg->header.typecookie) { 391 case NGM_BRIDGE_COOKIE: 392 switch (msg->header.cmd) { 393 case NGM_BRIDGE_GET_CONFIG: 394 { 395 struct ng_bridge_config *conf; 396 397 NG_MKRESPONSE(resp, msg, 398 sizeof(struct ng_bridge_config), M_NOWAIT); 399 if (resp == NULL) { 400 error = ENOMEM; 401 break; 402 } 403 conf = (struct ng_bridge_config *)resp->data; 404 *conf = priv->conf; /* no sanity checking needed */ 405 break; 406 } 407 case NGM_BRIDGE_SET_CONFIG: 408 { 409 struct ng_bridge_config *conf; 410 int i; 411 412 if (msg->header.arglen 413 != sizeof(struct ng_bridge_config)) { 414 error = EINVAL; 415 break; 416 } 417 conf = (struct ng_bridge_config *)msg->data; 418 priv->conf = *conf; 419 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) 420 priv->conf.ipfw[i] = !!priv->conf.ipfw[i]; 421 break; 422 } 423 case NGM_BRIDGE_RESET: 424 { 425 int i; 426 427 /* Flush all entries in the hash table */ 428 ng_bridge_remove_hosts(priv, -1); 429 430 /* Reset all loop detection counters and stats */ 431 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) { 432 if (priv->links[i] == NULL) 433 continue; 434 priv->links[i]->loopCount = 0; 435 bzero(&priv->links[i]->stats, 436 sizeof(priv->links[i]->stats)); 437 } 438 break; 439 } 440 case NGM_BRIDGE_GET_STATS: 441 case NGM_BRIDGE_CLR_STATS: 442 case NGM_BRIDGE_GETCLR_STATS: 443 { 444 struct ng_bridge_link *link; 445 int linkNum; 446 447 /* Get link number */ 448 if (msg->header.arglen != sizeof(u_int32_t)) { 449 error = EINVAL; 450 break; 451 } 452 linkNum = *((u_int32_t *)msg->data); 453 if (linkNum < 0 || linkNum >= NG_BRIDGE_MAX_LINKS) { 454 error = EINVAL; 455 break; 456 } 457 if ((link = priv->links[linkNum]) == NULL) { 458 error = ENOTCONN; 459 break; 460 } 461 462 /* Get/clear stats */ 463 if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) { 464 NG_MKRESPONSE(resp, msg, 465 sizeof(link->stats), M_NOWAIT); 466 if (resp == NULL) { 467 error = ENOMEM; 468 break; 469 } 470 bcopy(&link->stats, 471 resp->data, sizeof(link->stats)); 472 } 473 if (msg->header.cmd != NGM_BRIDGE_GET_STATS) 474 bzero(&link->stats, sizeof(link->stats)); 475 break; 476 } 477 case NGM_BRIDGE_GET_TABLE: 478 { 479 struct ng_bridge_host_ary *ary; 480 struct ng_bridge_hent *hent; 481 int i = 0, bucket; 482 483 NG_MKRESPONSE(resp, msg, sizeof(*ary) 484 + (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT); 485 if (resp == NULL) { 486 error = ENOMEM; 487 break; 488 } 489 ary = (struct ng_bridge_host_ary *)resp->data; 490 ary->numHosts = priv->numHosts; 491 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 492 SLIST_FOREACH(hent, &priv->tab[bucket], next) 493 ary->hosts[i++] = hent->host; 494 } 495 break; 496 } 497 default: 498 error = EINVAL; 499 break; 500 } 501 break; 502 default: 503 error = EINVAL; 504 break; 505 } 506 507 /* Done */ 508 NG_RESPOND_MSG(error, node, item, resp); 509 NG_FREE_MSG(msg); 510 return (error); 511 } 512 513 /* 514 * Receive data on a hook 515 */ 516 static int 517 ng_bridge_rcvdata(hook_p hook, item_p item) 518 { 519 const node_p node = NG_HOOK_NODE(hook); 520 const priv_p priv = NG_NODE_PRIVATE(node); 521 struct ng_bridge_host *host; 522 struct ng_bridge_link *link; 523 struct ether_header *eh; 524 int error = 0, linkNum, linksSeen; 525 int manycast; 526 struct mbuf *m; 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 0 637 if (priv->conf.ipfw[linkNum] && V_fw_enable && ip_fw_chk_ptr != NULL) { 638 /* XXX not implemented yet */ 639 } 640 #endif 641 642 /* 643 * If unicast and destination host known, deliver to host's link, 644 * unless it is the same link as the packet came in on. 645 */ 646 if (!manycast) { 647 648 /* Determine packet destination link */ 649 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) { 650 struct ng_bridge_link *const destLink 651 = priv->links[host->linkNum]; 652 653 /* If destination same as incoming link, do nothing */ 654 KASSERT(destLink != NULL, 655 ("%s: link%d null", __func__, host->linkNum)); 656 if (destLink == link) { 657 NG_FREE_ITEM(item); 658 NG_FREE_M(m); 659 return (0); 660 } 661 662 /* Deliver packet out the destination link */ 663 destLink->stats.xmitPackets++; 664 destLink->stats.xmitOctets += m->m_pkthdr.len; 665 NG_FWD_NEW_DATA(error, item, destLink->hook, m); 666 return (error); 667 } 668 669 /* Destination host is not known */ 670 link->stats.recvUnknown++; 671 } 672 673 /* Distribute unknown, multicast, broadcast pkts to all other links */ 674 firstLink = NULL; 675 for (linkNum = linksSeen = 0; linksSeen <= priv->numLinks; linkNum++) { 676 struct ng_bridge_link *destLink; 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 (linksSeen == 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 if (destLink != NULL) 694 linksSeen++; 695 /* Skip incoming link and disconnected links */ 696 if (destLink == NULL || destLink == link) { 697 continue; 698 } 699 if (firstLink == NULL) { 700 /* 701 * This is the first usable link we have found. 702 * Reserve it for the originals. 703 * If we never find another we save a copy. 704 */ 705 firstLink = destLink; 706 continue; 707 } 708 709 /* 710 * It's usable link but not the reserved (first) one. 711 * Copy mbuf info for sending. 712 */ 713 m2 = m_dup(m, M_DONTWAIT); /* XXX m_copypacket() */ 714 if (m2 == NULL) { 715 link->stats.memoryFailures++; 716 NG_FREE_ITEM(item); 717 NG_FREE_M(m); 718 return (ENOBUFS); 719 } 720 } 721 722 /* Update stats */ 723 destLink->stats.xmitPackets++; 724 destLink->stats.xmitOctets += m->m_pkthdr.len; 725 switch (manycast) { 726 case 0: /* unicast */ 727 break; 728 case 1: /* multicast */ 729 destLink->stats.xmitMulticasts++; 730 break; 731 case 2: /* broadcast */ 732 destLink->stats.xmitBroadcasts++; 733 break; 734 } 735 736 /* Send packet */ 737 if (destLink == firstLink) { 738 /* 739 * If we've sent all the others, send the original 740 * on the first link we found. 741 */ 742 NG_FWD_NEW_DATA(error, item, destLink->hook, m); 743 break; /* always done last - not really needed. */ 744 } else { 745 NG_SEND_DATA_ONLY(error, destLink->hook, m2); 746 } 747 } 748 return (error); 749 } 750 751 /* 752 * Shutdown node 753 */ 754 static int 755 ng_bridge_shutdown(node_p node) 756 { 757 const priv_p priv = NG_NODE_PRIVATE(node); 758 759 /* 760 * Shut down everything including the timer. Even if the 761 * callout has already been dequeued and is about to be 762 * run, ng_bridge_timeout() won't be fired as the node 763 * is already marked NGF_INVALID, so we're safe to free 764 * the node now. 765 */ 766 KASSERT(priv->numLinks == 0 && priv->numHosts == 0, 767 ("%s: numLinks=%d numHosts=%d", 768 __func__, priv->numLinks, priv->numHosts)); 769 ng_uncallout(&priv->timer, node); 770 NG_NODE_SET_PRIVATE(node, NULL); 771 NG_NODE_UNREF(node); 772 free(priv->tab, M_NETGRAPH_BRIDGE); 773 free(priv, M_NETGRAPH_BRIDGE); 774 return (0); 775 } 776 777 /* 778 * Hook disconnection. 779 */ 780 static int 781 ng_bridge_disconnect(hook_p hook) 782 { 783 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); 784 int linkNum; 785 786 /* Get link number */ 787 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook); 788 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 789 ("%s: linkNum=%u", __func__, linkNum)); 790 791 /* Remove all hosts associated with this link */ 792 ng_bridge_remove_hosts(priv, linkNum); 793 794 /* Free associated link information */ 795 KASSERT(priv->links[linkNum] != NULL, ("%s: no link", __func__)); 796 free(priv->links[linkNum], M_NETGRAPH_BRIDGE); 797 priv->links[linkNum] = NULL; 798 priv->numLinks--; 799 800 /* If no more hooks, go away */ 801 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) 802 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) { 803 ng_rmnode_self(NG_HOOK_NODE(hook)); 804 } 805 return (0); 806 } 807 808 /****************************************************************** 809 HASH TABLE FUNCTIONS 810 ******************************************************************/ 811 812 /* 813 * Hash algorithm 814 */ 815 #define HASH(addr,mask) ( (((const u_int16_t *)(addr))[0] \ 816 ^ ((const u_int16_t *)(addr))[1] \ 817 ^ ((const u_int16_t *)(addr))[2]) & (mask) ) 818 819 /* 820 * Find a host entry in the table. 821 */ 822 static struct ng_bridge_host * 823 ng_bridge_get(priv_p priv, const u_char *addr) 824 { 825 const int bucket = HASH(addr, priv->hashMask); 826 struct ng_bridge_hent *hent; 827 828 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 829 if (ETHER_EQUAL(hent->host.addr, addr)) 830 return (&hent->host); 831 } 832 return (NULL); 833 } 834 835 /* 836 * Add a new host entry to the table. This assumes the host doesn't 837 * already exist in the table. Returns 1 on success, 0 if there 838 * was a memory allocation failure. 839 */ 840 static int 841 ng_bridge_put(priv_p priv, const u_char *addr, int linkNum) 842 { 843 const int bucket = HASH(addr, priv->hashMask); 844 struct ng_bridge_hent *hent; 845 846 #ifdef INVARIANTS 847 /* Assert that entry does not already exist in hashtable */ 848 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 849 KASSERT(!ETHER_EQUAL(hent->host.addr, addr), 850 ("%s: entry %6D exists in table", __func__, addr, ":")); 851 } 852 #endif 853 854 /* Allocate and initialize new hashtable entry */ 855 hent = malloc(sizeof(*hent), M_NETGRAPH_BRIDGE, M_NOWAIT); 856 if (hent == NULL) 857 return (0); 858 bcopy(addr, hent->host.addr, ETHER_ADDR_LEN); 859 hent->host.linkNum = linkNum; 860 hent->host.staleness = 0; 861 hent->host.age = 0; 862 863 /* Add new element to hash bucket */ 864 SLIST_INSERT_HEAD(&priv->tab[bucket], hent, next); 865 priv->numHosts++; 866 867 /* Resize table if necessary */ 868 ng_bridge_rehash(priv); 869 return (1); 870 } 871 872 /* 873 * Resize the hash table. We try to maintain the number of buckets 874 * such that the load factor is in the range 0.25 to 1.0. 875 * 876 * If we can't get the new memory then we silently fail. This is OK 877 * because things will still work and we'll try again soon anyway. 878 */ 879 static void 880 ng_bridge_rehash(priv_p priv) 881 { 882 struct ng_bridge_bucket *newTab; 883 int oldBucket, newBucket; 884 int newNumBuckets; 885 u_int newMask; 886 887 /* Is table too full or too empty? */ 888 if (priv->numHosts > priv->numBuckets 889 && (priv->numBuckets << 1) <= MAX_BUCKETS) 890 newNumBuckets = priv->numBuckets << 1; 891 else if (priv->numHosts < (priv->numBuckets >> 2) 892 && (priv->numBuckets >> 2) >= MIN_BUCKETS) 893 newNumBuckets = priv->numBuckets >> 2; 894 else 895 return; 896 newMask = newNumBuckets - 1; 897 898 /* Allocate and initialize new table */ 899 newTab = malloc(newNumBuckets * sizeof(*newTab), 900 M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO); 901 if (newTab == NULL) 902 return; 903 904 /* Move all entries from old table to new table */ 905 for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) { 906 struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket]; 907 908 while (!SLIST_EMPTY(oldList)) { 909 struct ng_bridge_hent *const hent 910 = SLIST_FIRST(oldList); 911 912 SLIST_REMOVE_HEAD(oldList, next); 913 newBucket = HASH(hent->host.addr, newMask); 914 SLIST_INSERT_HEAD(&newTab[newBucket], hent, next); 915 } 916 } 917 918 /* Replace old table with new one */ 919 if (priv->conf.debugLevel >= 3) { 920 log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n", 921 ng_bridge_nodename(priv->node), 922 priv->numBuckets, newNumBuckets); 923 } 924 free(priv->tab, M_NETGRAPH_BRIDGE); 925 priv->numBuckets = newNumBuckets; 926 priv->hashMask = newMask; 927 priv->tab = newTab; 928 return; 929 } 930 931 /****************************************************************** 932 MISC FUNCTIONS 933 ******************************************************************/ 934 935 /* 936 * Remove all hosts associated with a specific link from the hashtable. 937 * If linkNum == -1, then remove all hosts in the table. 938 */ 939 static void 940 ng_bridge_remove_hosts(priv_p priv, int linkNum) 941 { 942 int bucket; 943 944 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 945 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 946 947 while (*hptr != NULL) { 948 struct ng_bridge_hent *const hent = *hptr; 949 950 if (linkNum == -1 || hent->host.linkNum == linkNum) { 951 *hptr = SLIST_NEXT(hent, next); 952 free(hent, M_NETGRAPH_BRIDGE); 953 priv->numHosts--; 954 } else 955 hptr = &SLIST_NEXT(hent, next); 956 } 957 } 958 } 959 960 /* 961 * Handle our once-per-second timeout event. We do two things: 962 * we decrement link->loopCount for those links being muted due to 963 * a detected loopback condition, and we remove any hosts from 964 * the hashtable whom we haven't heard from in a long while. 965 */ 966 static void 967 ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2) 968 { 969 const priv_p priv = NG_NODE_PRIVATE(node); 970 int bucket; 971 int counter = 0; 972 int linkNum; 973 974 /* Update host time counters and remove stale entries */ 975 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 976 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 977 978 while (*hptr != NULL) { 979 struct ng_bridge_hent *const hent = *hptr; 980 981 /* Make sure host's link really exists */ 982 KASSERT(priv->links[hent->host.linkNum] != NULL, 983 ("%s: host %6D on nonexistent link %d\n", 984 __func__, hent->host.addr, ":", 985 hent->host.linkNum)); 986 987 /* Remove hosts we haven't heard from in a while */ 988 if (++hent->host.staleness >= priv->conf.maxStaleness) { 989 *hptr = SLIST_NEXT(hent, next); 990 free(hent, M_NETGRAPH_BRIDGE); 991 priv->numHosts--; 992 } else { 993 if (hent->host.age < 0xffff) 994 hent->host.age++; 995 hptr = &SLIST_NEXT(hent, next); 996 counter++; 997 } 998 } 999 } 1000 KASSERT(priv->numHosts == counter, 1001 ("%s: hosts: %d != %d", __func__, priv->numHosts, counter)); 1002 1003 /* Decrease table size if necessary */ 1004 ng_bridge_rehash(priv); 1005 1006 /* Decrease loop counter on muted looped back links */ 1007 for (counter = linkNum = 0; linkNum < NG_BRIDGE_MAX_LINKS; linkNum++) { 1008 struct ng_bridge_link *const link = priv->links[linkNum]; 1009 1010 if (link != NULL) { 1011 if (link->loopCount != 0) { 1012 link->loopCount--; 1013 if (link->loopCount == 0 1014 && priv->conf.debugLevel >= 2) { 1015 log(LOG_INFO, "ng_bridge: %s:" 1016 " restoring looped back link%d\n", 1017 ng_bridge_nodename(node), linkNum); 1018 } 1019 } 1020 counter++; 1021 } 1022 } 1023 KASSERT(priv->numLinks == counter, 1024 ("%s: links: %d != %d", __func__, priv->numLinks, counter)); 1025 1026 /* Register a new timeout, keeping the existing node reference */ 1027 ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0); 1028 } 1029 1030 /* 1031 * Return node's "name", even if it doesn't have one. 1032 */ 1033 static const char * 1034 ng_bridge_nodename(node_p node) 1035 { 1036 static char name[NG_NODESIZ]; 1037 1038 if (NG_NODE_NAME(node) != NULL) 1039 snprintf(name, sizeof(name), "%s", NG_NODE_NAME(node)); 1040 else 1041 snprintf(name, sizeof(name), "[%x]", ng_node2ID(node)); 1042 return name; 1043 } 1044 1045