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: src/sys/netgraph/ng_bridge.c,v 1.31 2005/02/09 15:14:44 ru Exp $ 41 */ 42 43 /* 44 * ng_bridge(4) netgraph node type 45 * 46 * The node performs standard intelligent Ethernet bridging over 47 * each of its connected hooks, or links. A simple loop detection 48 * algorithm is included which disables a link for priv->conf.loopTimeout 49 * seconds when a host is seen to have jumped from one link to 50 * another within priv->conf.minStableAge seconds. 51 * 52 * We keep a hashtable that maps Ethernet addresses to host info, 53 * which is contained in struct ng_bridge_host's. These structures 54 * tell us on which link the host may be found. A host's entry will 55 * expire after priv->conf.maxStaleness seconds. 56 * 57 * This node is optimzed for stable networks, where machines jump 58 * from one port to the other only rarely. 59 */ 60 61 #include <sys/param.h> 62 #include <sys/systm.h> 63 #include <sys/kernel.h> 64 #include <sys/malloc.h> 65 #include <sys/mbuf.h> 66 #include <sys/errno.h> 67 #include <sys/syslog.h> 68 #include <sys/socket.h> 69 #include <sys/ctype.h> 70 71 #include <net/if.h> 72 #include <net/if_var.h> 73 #include <net/ethernet.h> 74 75 #include <netinet/in.h> 76 #include <net/ipfw/ip_fw.h> 77 78 #include <netgraph7/ng_message.h> 79 #include <netgraph7/netgraph.h> 80 #include <netgraph7/ng_parse.h> 81 #include "ng_bridge.h" 82 83 #ifdef NG_SEPARATE_MALLOC 84 MALLOC_DEFINE(M_NETGRAPH_BRIDGE, "netgraph_bridge", "netgraph bridge node "); 85 #else 86 #define M_NETGRAPH_BRIDGE M_NETGRAPH 87 #endif 88 89 /* Per-link private data */ 90 struct ng_bridge_link { 91 hook_p hook; /* netgraph hook */ 92 u_int16_t loopCount; /* loop ignore timer */ 93 struct ng_bridge_link_stats stats; /* link stats */ 94 }; 95 96 /* Per-node private data */ 97 struct ng_bridge_private { 98 struct ng_bridge_bucket *tab; /* hash table bucket array */ 99 struct ng_bridge_link *links[NG_BRIDGE_MAX_LINKS]; 100 struct ng_bridge_config conf; /* node configuration */ 101 node_p node; /* netgraph node */ 102 u_int numHosts; /* num entries in table */ 103 u_int numBuckets; /* num buckets in table */ 104 u_int hashMask; /* numBuckets - 1 */ 105 int numLinks; /* num connected links */ 106 struct callout timer; /* one second periodic timer */ 107 }; 108 typedef struct ng_bridge_private *priv_p; 109 110 /* Information about a host, stored in a hash table entry */ 111 struct ng_bridge_hent { 112 struct ng_bridge_host host; /* actual host info */ 113 SLIST_ENTRY(ng_bridge_hent) next; /* next entry in bucket */ 114 }; 115 116 /* Hash table bucket declaration */ 117 SLIST_HEAD(ng_bridge_bucket, ng_bridge_hent); 118 119 /* Netgraph node methods */ 120 static ng_constructor_t ng_bridge_constructor; 121 static ng_rcvmsg_t ng_bridge_rcvmsg; 122 static ng_shutdown_t ng_bridge_shutdown; 123 static ng_newhook_t ng_bridge_newhook; 124 static ng_rcvdata_t ng_bridge_rcvdata; 125 static ng_disconnect_t ng_bridge_disconnect; 126 127 /* Other internal functions */ 128 static struct ng_bridge_host *ng_bridge_get(priv_p priv, const u_char *addr); 129 static int ng_bridge_put(priv_p priv, const u_char *addr, int linkNum); 130 static void ng_bridge_rehash(priv_p priv); 131 static void ng_bridge_remove_hosts(priv_p priv, int linkNum); 132 static void ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2); 133 static const char *ng_bridge_nodename(node_p node); 134 135 /* Ethernet broadcast */ 136 static const u_char ng_bridge_bcast_addr[ETHER_ADDR_LEN] = 137 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; 138 139 /* Store each hook's link number in the private field */ 140 #define LINK_NUM(hook) (*(u_int16_t *)(&(hook)->private)) 141 142 /* Compare Ethernet addresses using 32 and 16 bit words instead of bytewise */ 143 #define ETHER_EQUAL(a,b) (((const u_int32_t *)(a))[0] \ 144 == ((const u_int32_t *)(b))[0] \ 145 && ((const u_int16_t *)(a))[2] \ 146 == ((const u_int16_t *)(b))[2]) 147 148 /* Minimum and maximum number of hash buckets. Must be a power of two. */ 149 #define MIN_BUCKETS (1 << 5) /* 32 */ 150 #define MAX_BUCKETS (1 << 14) /* 16384 */ 151 152 /* Configuration default values */ 153 #define DEFAULT_LOOP_TIMEOUT 60 154 #define DEFAULT_MAX_STALENESS (15 * 60) /* same as ARP timeout */ 155 #define DEFAULT_MIN_STABLE_AGE 1 156 157 /****************************************************************** 158 NETGRAPH PARSE TYPES 159 ******************************************************************/ 160 161 /* 162 * How to determine the length of the table returned by NGM_BRIDGE_GET_TABLE 163 */ 164 static int 165 ng_bridge_getTableLength(const struct ng_parse_type *type, 166 const u_char *start, const u_char *buf) 167 { 168 const struct ng_bridge_host_ary *const hary 169 = (const struct ng_bridge_host_ary *)(buf - sizeof(u_int32_t)); 170 171 return hary->numHosts; 172 } 173 174 /* Parse type for struct ng_bridge_host_ary */ 175 static const struct ng_parse_struct_field ng_bridge_host_type_fields[] 176 = NG_BRIDGE_HOST_TYPE_INFO(&ng_parse_enaddr_type); 177 static const struct ng_parse_type ng_bridge_host_type = { 178 &ng_parse_struct_type, 179 &ng_bridge_host_type_fields 180 }; 181 static const struct ng_parse_array_info ng_bridge_hary_type_info = { 182 &ng_bridge_host_type, 183 ng_bridge_getTableLength 184 }; 185 static const struct ng_parse_type ng_bridge_hary_type = { 186 &ng_parse_array_type, 187 &ng_bridge_hary_type_info 188 }; 189 static const struct ng_parse_struct_field ng_bridge_host_ary_type_fields[] 190 = NG_BRIDGE_HOST_ARY_TYPE_INFO(&ng_bridge_hary_type); 191 static const struct ng_parse_type ng_bridge_host_ary_type = { 192 &ng_parse_struct_type, 193 &ng_bridge_host_ary_type_fields 194 }; 195 196 /* Parse type for struct ng_bridge_config */ 197 static const struct ng_parse_fixedarray_info ng_bridge_ipfwary_type_info = { 198 &ng_parse_uint8_type, 199 NG_BRIDGE_MAX_LINKS 200 }; 201 static const struct ng_parse_type ng_bridge_ipfwary_type = { 202 &ng_parse_fixedarray_type, 203 &ng_bridge_ipfwary_type_info 204 }; 205 static const struct ng_parse_struct_field ng_bridge_config_type_fields[] 206 = NG_BRIDGE_CONFIG_TYPE_INFO(&ng_bridge_ipfwary_type); 207 static const struct ng_parse_type ng_bridge_config_type = { 208 &ng_parse_struct_type, 209 &ng_bridge_config_type_fields 210 }; 211 212 /* Parse type for struct ng_bridge_link_stat */ 213 static const struct ng_parse_struct_field ng_bridge_stats_type_fields[] 214 = NG_BRIDGE_STATS_TYPE_INFO; 215 static const struct ng_parse_type ng_bridge_stats_type = { 216 &ng_parse_struct_type, 217 &ng_bridge_stats_type_fields 218 }; 219 220 /* List of commands and how to convert arguments to/from ASCII */ 221 static const struct ng_cmdlist ng_bridge_cmdlist[] = { 222 { 223 NGM_BRIDGE_COOKIE, 224 NGM_BRIDGE_SET_CONFIG, 225 "setconfig", 226 &ng_bridge_config_type, 227 NULL 228 }, 229 { 230 NGM_BRIDGE_COOKIE, 231 NGM_BRIDGE_GET_CONFIG, 232 "getconfig", 233 NULL, 234 &ng_bridge_config_type 235 }, 236 { 237 NGM_BRIDGE_COOKIE, 238 NGM_BRIDGE_RESET, 239 "reset", 240 NULL, 241 NULL 242 }, 243 { 244 NGM_BRIDGE_COOKIE, 245 NGM_BRIDGE_GET_STATS, 246 "getstats", 247 &ng_parse_uint32_type, 248 &ng_bridge_stats_type 249 }, 250 { 251 NGM_BRIDGE_COOKIE, 252 NGM_BRIDGE_CLR_STATS, 253 "clrstats", 254 &ng_parse_uint32_type, 255 NULL 256 }, 257 { 258 NGM_BRIDGE_COOKIE, 259 NGM_BRIDGE_GETCLR_STATS, 260 "getclrstats", 261 &ng_parse_uint32_type, 262 &ng_bridge_stats_type 263 }, 264 { 265 NGM_BRIDGE_COOKIE, 266 NGM_BRIDGE_GET_TABLE, 267 "gettable", 268 NULL, 269 &ng_bridge_host_ary_type 270 }, 271 { 0 } 272 }; 273 274 /* Node type descriptor */ 275 static struct ng_type ng_bridge_typestruct = { 276 .version = NG_ABI_VERSION, 277 .name = NG_BRIDGE_NODE_TYPE, 278 .constructor = ng_bridge_constructor, 279 .rcvmsg = ng_bridge_rcvmsg, 280 .shutdown = ng_bridge_shutdown, 281 .newhook = ng_bridge_newhook, 282 .rcvdata = ng_bridge_rcvdata, 283 .disconnect = ng_bridge_disconnect, 284 .cmdlist = ng_bridge_cmdlist, 285 }; 286 NETGRAPH_INIT(bridge, &ng_bridge_typestruct); 287 288 /****************************************************************** 289 NETGRAPH NODE METHODS 290 ******************************************************************/ 291 292 /* 293 * Node constructor 294 */ 295 static int 296 ng_bridge_constructor(node_p node) 297 { 298 priv_p priv; 299 300 /* Allocate and initialize private info */ 301 priv = kmalloc(sizeof(*priv), M_NETGRAPH_BRIDGE, 302 M_WAITOK | M_NULLOK | M_ZERO); 303 if (priv == NULL) 304 return (ENOMEM); 305 ng_callout_init(&priv->timer); 306 307 /* Allocate and initialize hash table, etc. */ 308 priv->tab = kmalloc(MIN_BUCKETS * sizeof(*priv->tab), 309 M_NETGRAPH_BRIDGE, M_WAITOK | M_NULLOK | M_ZERO); 310 if (priv->tab == NULL) { 311 kfree(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 ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0); 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 priv->links[linkNum] = kmalloc(sizeof(*priv->links[linkNum]), 364 M_NETGRAPH_BRIDGE, 365 M_WAITOK | M_NULLOK | 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_WAITOK | M_NULLOK); 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_WAITOK | M_NULLOK); 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_WAITOK | M_NULLOK); 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 ksnprintf(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] && 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_NOWAIT); /* 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 kfree(priv->tab, M_NETGRAPH_BRIDGE); 773 kfree(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 kfree(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 char ethstr[ETHER_ADDRSTRLEN + 1] __debugvar; 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 %s exists in table", __func__, kether_ntoa(addr, ethstr))); 852 } 853 #endif 854 855 /* Allocate and initialize new hashtable entry */ 856 hent = kmalloc(sizeof(*hent), M_NETGRAPH_BRIDGE, M_WAITOK | M_NULLOK); 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 = kmalloc(newNumBuckets * sizeof(*newTab), M_NETGRAPH_BRIDGE, 901 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 kfree(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 kfree(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 char ethstr[ETHER_ADDRSTRLEN + 1] __debugvar; 975 976 /* Update host time counters and remove stale entries */ 977 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 978 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 979 980 while (*hptr != NULL) { 981 struct ng_bridge_hent *const hent = *hptr; 982 983 /* Make sure host's link really exists */ 984 KASSERT(priv->links[hent->host.linkNum] != NULL, 985 ("%s: host %s on nonexistent link %d", 986 __func__, kether_ntoa(hent->host.addr, ethstr), 987 hent->host.linkNum)); 988 989 /* Remove hosts we haven't heard from in a while */ 990 if (++hent->host.staleness >= priv->conf.maxStaleness) { 991 *hptr = SLIST_NEXT(hent, next); 992 kfree(hent, M_NETGRAPH_BRIDGE); 993 priv->numHosts--; 994 } else { 995 if (hent->host.age < 0xffff) 996 hent->host.age++; 997 hptr = &SLIST_NEXT(hent, next); 998 counter++; 999 } 1000 } 1001 } 1002 KASSERT(priv->numHosts == counter, 1003 ("%s: hosts: %d != %d", __func__, priv->numHosts, counter)); 1004 1005 /* Decrease table size if necessary */ 1006 ng_bridge_rehash(priv); 1007 1008 /* Decrease loop counter on muted looped back links */ 1009 for (counter = linkNum = 0; linkNum < NG_BRIDGE_MAX_LINKS; linkNum++) { 1010 struct ng_bridge_link *const link = priv->links[linkNum]; 1011 1012 if (link != NULL) { 1013 if (link->loopCount != 0) { 1014 link->loopCount--; 1015 if (link->loopCount == 0 1016 && priv->conf.debugLevel >= 2) { 1017 log(LOG_INFO, "ng_bridge: %s:" 1018 " restoring looped back link%d\n", 1019 ng_bridge_nodename(node), linkNum); 1020 } 1021 } 1022 counter++; 1023 } 1024 } 1025 KASSERT(priv->numLinks == counter, 1026 ("%s: links: %d != %d", __func__, priv->numLinks, counter)); 1027 1028 /* Register a new timeout, keeping the existing node reference */ 1029 ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0); 1030 } 1031 1032 /* 1033 * Return node's "name", even if it doesn't have one. 1034 */ 1035 static const char * 1036 ng_bridge_nodename(node_p node) 1037 { 1038 static char name[NG_NODESIZ]; 1039 1040 if (NG_NODE_NAME(node) != NULL) 1041 ksnprintf(name, sizeof(name), "%s", NG_NODE_NAME(node)); 1042 else 1043 ksnprintf(name, sizeof(name), "[%x]", ng_node2ID(node)); 1044 return name; 1045 } 1046 1047