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/ethernet.h> 73 74 #include <netinet/in.h> 75 #include <net/ipfw/ip_fw.h> 76 77 #include <netgraph7/ng_message.h> 78 #include <netgraph7/netgraph.h> 79 #include <netgraph7/ng_parse.h> 80 #include "ng_bridge.h" 81 82 #ifdef NG_SEPARATE_MALLOC 83 MALLOC_DEFINE(M_NETGRAPH_BRIDGE, "netgraph_bridge", "netgraph bridge node "); 84 #else 85 #define M_NETGRAPH_BRIDGE M_NETGRAPH 86 #endif 87 88 /* Per-link private data */ 89 struct ng_bridge_link { 90 hook_p hook; /* netgraph hook */ 91 u_int16_t loopCount; /* loop ignore timer */ 92 struct ng_bridge_link_stats stats; /* link stats */ 93 }; 94 95 /* Per-node private data */ 96 struct ng_bridge_private { 97 struct ng_bridge_bucket *tab; /* hash table bucket array */ 98 struct ng_bridge_link *links[NG_BRIDGE_MAX_LINKS]; 99 struct ng_bridge_config conf; /* node configuration */ 100 node_p node; /* netgraph node */ 101 u_int numHosts; /* num entries in table */ 102 u_int numBuckets; /* num buckets in table */ 103 u_int hashMask; /* numBuckets - 1 */ 104 int numLinks; /* num connected links */ 105 struct callout timer; /* one second periodic timer */ 106 }; 107 typedef struct ng_bridge_private *priv_p; 108 109 /* Information about a host, stored in a hash table entry */ 110 struct ng_bridge_hent { 111 struct ng_bridge_host host; /* actual host info */ 112 SLIST_ENTRY(ng_bridge_hent) next; /* next entry in bucket */ 113 }; 114 115 /* Hash table bucket declaration */ 116 SLIST_HEAD(ng_bridge_bucket, ng_bridge_hent); 117 118 /* Netgraph node methods */ 119 static ng_constructor_t ng_bridge_constructor; 120 static ng_rcvmsg_t ng_bridge_rcvmsg; 121 static ng_shutdown_t ng_bridge_shutdown; 122 static ng_newhook_t ng_bridge_newhook; 123 static ng_rcvdata_t ng_bridge_rcvdata; 124 static ng_disconnect_t ng_bridge_disconnect; 125 126 /* Other internal functions */ 127 static struct ng_bridge_host *ng_bridge_get(priv_p priv, const u_char *addr); 128 static int ng_bridge_put(priv_p priv, const u_char *addr, int linkNum); 129 static void ng_bridge_rehash(priv_p priv); 130 static void ng_bridge_remove_hosts(priv_p priv, int linkNum); 131 static void ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2); 132 static const char *ng_bridge_nodename(node_p node); 133 134 /* Ethernet broadcast */ 135 static const u_char ng_bridge_bcast_addr[ETHER_ADDR_LEN] = 136 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; 137 138 /* Store each hook's link number in the private field */ 139 #define LINK_NUM(hook) (*(u_int16_t *)(&(hook)->private)) 140 141 /* Compare Ethernet addresses using 32 and 16 bit words instead of bytewise */ 142 #define ETHER_EQUAL(a,b) (((const u_int32_t *)(a))[0] \ 143 == ((const u_int32_t *)(b))[0] \ 144 && ((const u_int16_t *)(a))[2] \ 145 == ((const u_int16_t *)(b))[2]) 146 147 /* Minimum and maximum number of hash buckets. Must be a power of two. */ 148 #define MIN_BUCKETS (1 << 5) /* 32 */ 149 #define MAX_BUCKETS (1 << 14) /* 16384 */ 150 151 /* Configuration default values */ 152 #define DEFAULT_LOOP_TIMEOUT 60 153 #define DEFAULT_MAX_STALENESS (15 * 60) /* same as ARP timeout */ 154 #define DEFAULT_MIN_STABLE_AGE 1 155 156 /****************************************************************** 157 NETGRAPH PARSE TYPES 158 ******************************************************************/ 159 160 /* 161 * How to determine the length of the table returned by NGM_BRIDGE_GET_TABLE 162 */ 163 static int 164 ng_bridge_getTableLength(const struct ng_parse_type *type, 165 const u_char *start, const u_char *buf) 166 { 167 const struct ng_bridge_host_ary *const hary 168 = (const struct ng_bridge_host_ary *)(buf - sizeof(u_int32_t)); 169 170 return hary->numHosts; 171 } 172 173 /* Parse type for struct ng_bridge_host_ary */ 174 static const struct ng_parse_struct_field ng_bridge_host_type_fields[] 175 = NG_BRIDGE_HOST_TYPE_INFO(&ng_parse_enaddr_type); 176 static const struct ng_parse_type ng_bridge_host_type = { 177 &ng_parse_struct_type, 178 &ng_bridge_host_type_fields 179 }; 180 static const struct ng_parse_array_info ng_bridge_hary_type_info = { 181 &ng_bridge_host_type, 182 ng_bridge_getTableLength 183 }; 184 static const struct ng_parse_type ng_bridge_hary_type = { 185 &ng_parse_array_type, 186 &ng_bridge_hary_type_info 187 }; 188 static const struct ng_parse_struct_field ng_bridge_host_ary_type_fields[] 189 = NG_BRIDGE_HOST_ARY_TYPE_INFO(&ng_bridge_hary_type); 190 static const struct ng_parse_type ng_bridge_host_ary_type = { 191 &ng_parse_struct_type, 192 &ng_bridge_host_ary_type_fields 193 }; 194 195 /* Parse type for struct ng_bridge_config */ 196 static const struct ng_parse_fixedarray_info ng_bridge_ipfwary_type_info = { 197 &ng_parse_uint8_type, 198 NG_BRIDGE_MAX_LINKS 199 }; 200 static const struct ng_parse_type ng_bridge_ipfwary_type = { 201 &ng_parse_fixedarray_type, 202 &ng_bridge_ipfwary_type_info 203 }; 204 static const struct ng_parse_struct_field ng_bridge_config_type_fields[] 205 = NG_BRIDGE_CONFIG_TYPE_INFO(&ng_bridge_ipfwary_type); 206 static const struct ng_parse_type ng_bridge_config_type = { 207 &ng_parse_struct_type, 208 &ng_bridge_config_type_fields 209 }; 210 211 /* Parse type for struct ng_bridge_link_stat */ 212 static const struct ng_parse_struct_field ng_bridge_stats_type_fields[] 213 = NG_BRIDGE_STATS_TYPE_INFO; 214 static const struct ng_parse_type ng_bridge_stats_type = { 215 &ng_parse_struct_type, 216 &ng_bridge_stats_type_fields 217 }; 218 219 /* List of commands and how to convert arguments to/from ASCII */ 220 static const struct ng_cmdlist ng_bridge_cmdlist[] = { 221 { 222 NGM_BRIDGE_COOKIE, 223 NGM_BRIDGE_SET_CONFIG, 224 "setconfig", 225 &ng_bridge_config_type, 226 NULL 227 }, 228 { 229 NGM_BRIDGE_COOKIE, 230 NGM_BRIDGE_GET_CONFIG, 231 "getconfig", 232 NULL, 233 &ng_bridge_config_type 234 }, 235 { 236 NGM_BRIDGE_COOKIE, 237 NGM_BRIDGE_RESET, 238 "reset", 239 NULL, 240 NULL 241 }, 242 { 243 NGM_BRIDGE_COOKIE, 244 NGM_BRIDGE_GET_STATS, 245 "getstats", 246 &ng_parse_uint32_type, 247 &ng_bridge_stats_type 248 }, 249 { 250 NGM_BRIDGE_COOKIE, 251 NGM_BRIDGE_CLR_STATS, 252 "clrstats", 253 &ng_parse_uint32_type, 254 NULL 255 }, 256 { 257 NGM_BRIDGE_COOKIE, 258 NGM_BRIDGE_GETCLR_STATS, 259 "getclrstats", 260 &ng_parse_uint32_type, 261 &ng_bridge_stats_type 262 }, 263 { 264 NGM_BRIDGE_COOKIE, 265 NGM_BRIDGE_GET_TABLE, 266 "gettable", 267 NULL, 268 &ng_bridge_host_ary_type 269 }, 270 { 0 } 271 }; 272 273 /* Node type descriptor */ 274 static struct ng_type ng_bridge_typestruct = { 275 .version = NG_ABI_VERSION, 276 .name = NG_BRIDGE_NODE_TYPE, 277 .constructor = ng_bridge_constructor, 278 .rcvmsg = ng_bridge_rcvmsg, 279 .shutdown = ng_bridge_shutdown, 280 .newhook = ng_bridge_newhook, 281 .rcvdata = ng_bridge_rcvdata, 282 .disconnect = ng_bridge_disconnect, 283 .cmdlist = ng_bridge_cmdlist, 284 }; 285 NETGRAPH_INIT(bridge, &ng_bridge_typestruct); 286 287 /****************************************************************** 288 NETGRAPH NODE METHODS 289 ******************************************************************/ 290 291 /* 292 * Node constructor 293 */ 294 static int 295 ng_bridge_constructor(node_p node) 296 { 297 priv_p priv; 298 299 /* Allocate and initialize private info */ 300 priv = kmalloc(sizeof(*priv), M_NETGRAPH_BRIDGE, 301 M_WAITOK | M_NULLOK | M_ZERO); 302 if (priv == NULL) 303 return (ENOMEM); 304 ng_callout_init(&priv->timer); 305 306 /* Allocate and initialize hash table, etc. */ 307 priv->tab = kmalloc(MIN_BUCKETS * sizeof(*priv->tab), 308 M_NETGRAPH_BRIDGE, M_WAITOK | M_NULLOK | M_ZERO); 309 if (priv->tab == NULL) { 310 kfree(priv, M_NETGRAPH_BRIDGE); 311 return (ENOMEM); 312 } 313 priv->numBuckets = MIN_BUCKETS; 314 priv->hashMask = MIN_BUCKETS - 1; 315 priv->conf.debugLevel = 1; 316 priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT; 317 priv->conf.maxStaleness = DEFAULT_MAX_STALENESS; 318 priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE; 319 320 /* 321 * This node has all kinds of stuff that could be screwed by SMP. 322 * Until it gets it's own internal protection, we go through in 323 * single file. This could hurt a machine bridging beteen two 324 * GB ethernets so it should be fixed. 325 * When it's fixed the process SHOULD NOT SLEEP, spinlocks please! 326 * (and atomic ops ) 327 */ 328 NG_NODE_FORCE_WRITER(node); 329 NG_NODE_SET_PRIVATE(node, priv); 330 priv->node = node; 331 332 /* Start timer; timer is always running while node is alive */ 333 ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0); 334 335 /* Done */ 336 return (0); 337 } 338 339 /* 340 * Method for attaching a new hook 341 */ 342 static int 343 ng_bridge_newhook(node_p node, hook_p hook, const char *name) 344 { 345 const priv_p priv = NG_NODE_PRIVATE(node); 346 347 /* Check for a link hook */ 348 if (strncmp(name, NG_BRIDGE_HOOK_LINK_PREFIX, 349 strlen(NG_BRIDGE_HOOK_LINK_PREFIX)) == 0) { 350 const char *cp; 351 char *eptr; 352 u_long linkNum; 353 354 cp = name + strlen(NG_BRIDGE_HOOK_LINK_PREFIX); 355 if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0')) 356 return (EINVAL); 357 linkNum = strtoul(cp, &eptr, 10); 358 if (*eptr != '\0' || linkNum >= NG_BRIDGE_MAX_LINKS) 359 return (EINVAL); 360 if (priv->links[linkNum] != NULL) 361 return (EISCONN); 362 priv->links[linkNum] = kmalloc(sizeof(*priv->links[linkNum]), 363 M_NETGRAPH_BRIDGE, 364 M_WAITOK | M_NULLOK | M_ZERO); 365 if (priv->links[linkNum] == NULL) 366 return (ENOMEM); 367 priv->links[linkNum]->hook = hook; 368 NG_HOOK_SET_PRIVATE(hook, (void *)linkNum); 369 priv->numLinks++; 370 return (0); 371 } 372 373 /* Unknown hook name */ 374 return (EINVAL); 375 } 376 377 /* 378 * Receive a control message 379 */ 380 static int 381 ng_bridge_rcvmsg(node_p node, item_p item, hook_p lasthook) 382 { 383 const priv_p priv = NG_NODE_PRIVATE(node); 384 struct ng_mesg *resp = NULL; 385 int error = 0; 386 struct ng_mesg *msg; 387 388 NGI_GET_MSG(item, msg); 389 switch (msg->header.typecookie) { 390 case NGM_BRIDGE_COOKIE: 391 switch (msg->header.cmd) { 392 case NGM_BRIDGE_GET_CONFIG: 393 { 394 struct ng_bridge_config *conf; 395 396 NG_MKRESPONSE(resp, msg, 397 sizeof(struct ng_bridge_config), M_WAITOK | M_NULLOK); 398 if (resp == NULL) { 399 error = ENOMEM; 400 break; 401 } 402 conf = (struct ng_bridge_config *)resp->data; 403 *conf = priv->conf; /* no sanity checking needed */ 404 break; 405 } 406 case NGM_BRIDGE_SET_CONFIG: 407 { 408 struct ng_bridge_config *conf; 409 int i; 410 411 if (msg->header.arglen 412 != sizeof(struct ng_bridge_config)) { 413 error = EINVAL; 414 break; 415 } 416 conf = (struct ng_bridge_config *)msg->data; 417 priv->conf = *conf; 418 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) 419 priv->conf.ipfw[i] = !!priv->conf.ipfw[i]; 420 break; 421 } 422 case NGM_BRIDGE_RESET: 423 { 424 int i; 425 426 /* Flush all entries in the hash table */ 427 ng_bridge_remove_hosts(priv, -1); 428 429 /* Reset all loop detection counters and stats */ 430 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) { 431 if (priv->links[i] == NULL) 432 continue; 433 priv->links[i]->loopCount = 0; 434 bzero(&priv->links[i]->stats, 435 sizeof(priv->links[i]->stats)); 436 } 437 break; 438 } 439 case NGM_BRIDGE_GET_STATS: 440 case NGM_BRIDGE_CLR_STATS: 441 case NGM_BRIDGE_GETCLR_STATS: 442 { 443 struct ng_bridge_link *link; 444 int linkNum; 445 446 /* Get link number */ 447 if (msg->header.arglen != sizeof(u_int32_t)) { 448 error = EINVAL; 449 break; 450 } 451 linkNum = *((u_int32_t *)msg->data); 452 if (linkNum < 0 || linkNum >= NG_BRIDGE_MAX_LINKS) { 453 error = EINVAL; 454 break; 455 } 456 if ((link = priv->links[linkNum]) == NULL) { 457 error = ENOTCONN; 458 break; 459 } 460 461 /* Get/clear stats */ 462 if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) { 463 NG_MKRESPONSE(resp, msg, 464 sizeof(link->stats), M_WAITOK | M_NULLOK); 465 if (resp == NULL) { 466 error = ENOMEM; 467 break; 468 } 469 bcopy(&link->stats, 470 resp->data, sizeof(link->stats)); 471 } 472 if (msg->header.cmd != NGM_BRIDGE_GET_STATS) 473 bzero(&link->stats, sizeof(link->stats)); 474 break; 475 } 476 case NGM_BRIDGE_GET_TABLE: 477 { 478 struct ng_bridge_host_ary *ary; 479 struct ng_bridge_hent *hent; 480 int i = 0, bucket; 481 482 NG_MKRESPONSE(resp, msg, sizeof(*ary) 483 + (priv->numHosts * sizeof(*ary->hosts)), M_WAITOK | M_NULLOK); 484 if (resp == NULL) { 485 error = ENOMEM; 486 break; 487 } 488 ary = (struct ng_bridge_host_ary *)resp->data; 489 ary->numHosts = priv->numHosts; 490 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 491 SLIST_FOREACH(hent, &priv->tab[bucket], next) 492 ary->hosts[i++] = hent->host; 493 } 494 break; 495 } 496 default: 497 error = EINVAL; 498 break; 499 } 500 break; 501 default: 502 error = EINVAL; 503 break; 504 } 505 506 /* Done */ 507 NG_RESPOND_MSG(error, node, item, resp); 508 NG_FREE_MSG(msg); 509 return (error); 510 } 511 512 /* 513 * Receive data on a hook 514 */ 515 static int 516 ng_bridge_rcvdata(hook_p hook, item_p item) 517 { 518 const node_p node = NG_HOOK_NODE(hook); 519 const priv_p priv = NG_NODE_PRIVATE(node); 520 struct ng_bridge_host *host; 521 struct ng_bridge_link *link; 522 struct ether_header *eh; 523 int error = 0, linkNum, linksSeen; 524 int manycast; 525 struct mbuf *m; 526 struct ng_bridge_link *firstLink; 527 528 NGI_GET_M(item, m); 529 /* Get link number */ 530 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook); 531 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 532 ("%s: linkNum=%u", __func__, linkNum)); 533 link = priv->links[linkNum]; 534 KASSERT(link != NULL, ("%s: link%d null", __func__, linkNum)); 535 536 /* Sanity check packet and pull up header */ 537 if (m->m_pkthdr.len < ETHER_HDR_LEN) { 538 link->stats.recvRunts++; 539 NG_FREE_ITEM(item); 540 NG_FREE_M(m); 541 return (EINVAL); 542 } 543 if (m->m_len < ETHER_HDR_LEN && !(m = m_pullup(m, ETHER_HDR_LEN))) { 544 link->stats.memoryFailures++; 545 NG_FREE_ITEM(item); 546 return (ENOBUFS); 547 } 548 eh = mtod(m, struct ether_header *); 549 if ((eh->ether_shost[0] & 1) != 0) { 550 link->stats.recvInvalid++; 551 NG_FREE_ITEM(item); 552 NG_FREE_M(m); 553 return (EINVAL); 554 } 555 556 /* Is link disabled due to a loopback condition? */ 557 if (link->loopCount != 0) { 558 link->stats.loopDrops++; 559 NG_FREE_ITEM(item); 560 NG_FREE_M(m); 561 return (ELOOP); /* XXX is this an appropriate error? */ 562 } 563 564 /* Update stats */ 565 link->stats.recvPackets++; 566 link->stats.recvOctets += m->m_pkthdr.len; 567 if ((manycast = (eh->ether_dhost[0] & 1)) != 0) { 568 if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) { 569 link->stats.recvBroadcasts++; 570 manycast = 2; 571 } else 572 link->stats.recvMulticasts++; 573 } 574 575 /* Look up packet's source Ethernet address in hashtable */ 576 if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) { 577 578 /* Update time since last heard from this host */ 579 host->staleness = 0; 580 581 /* Did host jump to a different link? */ 582 if (host->linkNum != linkNum) { 583 584 /* 585 * If the host's old link was recently established 586 * on the old link and it's already jumped to a new 587 * link, declare a loopback condition. 588 */ 589 if (host->age < priv->conf.minStableAge) { 590 591 /* Log the problem */ 592 if (priv->conf.debugLevel >= 2) { 593 struct ifnet *ifp = m->m_pkthdr.rcvif; 594 char suffix[32]; 595 596 if (ifp != NULL) 597 ksnprintf(suffix, sizeof(suffix), 598 " (%s)", ifp->if_xname); 599 else 600 *suffix = '\0'; 601 log(LOG_WARNING, "ng_bridge: %s:" 602 " loopback detected on %s%s\n", 603 ng_bridge_nodename(node), 604 NG_HOOK_NAME(hook), suffix); 605 } 606 607 /* Mark link as linka non grata */ 608 link->loopCount = priv->conf.loopTimeout; 609 link->stats.loopDetects++; 610 611 /* Forget all hosts on this link */ 612 ng_bridge_remove_hosts(priv, linkNum); 613 614 /* Drop packet */ 615 link->stats.loopDrops++; 616 NG_FREE_ITEM(item); 617 NG_FREE_M(m); 618 return (ELOOP); /* XXX appropriate? */ 619 } 620 621 /* Move host over to new link */ 622 host->linkNum = linkNum; 623 host->age = 0; 624 } 625 } else { 626 if (!ng_bridge_put(priv, eh->ether_shost, linkNum)) { 627 link->stats.memoryFailures++; 628 NG_FREE_ITEM(item); 629 NG_FREE_M(m); 630 return (ENOMEM); 631 } 632 } 633 634 /* Run packet through ipfw processing, if enabled */ 635 #if 0 636 if (priv->conf.ipfw[linkNum] && fw_enable && ip_fw_chk_ptr != NULL) { 637 /* XXX not implemented yet */ 638 } 639 #endif 640 641 /* 642 * If unicast and destination host known, deliver to host's link, 643 * unless it is the same link as the packet came in on. 644 */ 645 if (!manycast) { 646 647 /* Determine packet destination link */ 648 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) { 649 struct ng_bridge_link *const destLink 650 = priv->links[host->linkNum]; 651 652 /* If destination same as incoming link, do nothing */ 653 KASSERT(destLink != NULL, 654 ("%s: link%d null", __func__, host->linkNum)); 655 if (destLink == link) { 656 NG_FREE_ITEM(item); 657 NG_FREE_M(m); 658 return (0); 659 } 660 661 /* Deliver packet out the destination link */ 662 destLink->stats.xmitPackets++; 663 destLink->stats.xmitOctets += m->m_pkthdr.len; 664 NG_FWD_NEW_DATA(error, item, destLink->hook, m); 665 return (error); 666 } 667 668 /* Destination host is not known */ 669 link->stats.recvUnknown++; 670 } 671 672 /* Distribute unknown, multicast, broadcast pkts to all other links */ 673 firstLink = NULL; 674 for (linkNum = linksSeen = 0; linksSeen <= priv->numLinks; linkNum++) { 675 struct ng_bridge_link *destLink; 676 struct mbuf *m2 = NULL; 677 678 /* 679 * If we have checked all the links then now 680 * send the original on its reserved link 681 */ 682 if (linksSeen == priv->numLinks) { 683 /* If we never saw a good link, leave. */ 684 if (firstLink == NULL) { 685 NG_FREE_ITEM(item); 686 NG_FREE_M(m); 687 return (0); 688 } 689 destLink = firstLink; 690 } else { 691 destLink = priv->links[linkNum]; 692 if (destLink != NULL) 693 linksSeen++; 694 /* Skip incoming link and disconnected links */ 695 if (destLink == NULL || destLink == link) { 696 continue; 697 } 698 if (firstLink == NULL) { 699 /* 700 * This is the first usable link we have found. 701 * Reserve it for the originals. 702 * If we never find another we save a copy. 703 */ 704 firstLink = destLink; 705 continue; 706 } 707 708 /* 709 * It's usable link but not the reserved (first) one. 710 * Copy mbuf info for sending. 711 */ 712 m2 = m_dup(m, MB_DONTWAIT); /* XXX m_copypacket() */ 713 if (m2 == NULL) { 714 link->stats.memoryFailures++; 715 NG_FREE_ITEM(item); 716 NG_FREE_M(m); 717 return (ENOBUFS); 718 } 719 } 720 721 /* Update stats */ 722 destLink->stats.xmitPackets++; 723 destLink->stats.xmitOctets += m->m_pkthdr.len; 724 switch (manycast) { 725 case 0: /* unicast */ 726 break; 727 case 1: /* multicast */ 728 destLink->stats.xmitMulticasts++; 729 break; 730 case 2: /* broadcast */ 731 destLink->stats.xmitBroadcasts++; 732 break; 733 } 734 735 /* Send packet */ 736 if (destLink == firstLink) { 737 /* 738 * If we've sent all the others, send the original 739 * on the first link we found. 740 */ 741 NG_FWD_NEW_DATA(error, item, destLink->hook, m); 742 break; /* always done last - not really needed. */ 743 } else { 744 NG_SEND_DATA_ONLY(error, destLink->hook, m2); 745 } 746 } 747 return (error); 748 } 749 750 /* 751 * Shutdown node 752 */ 753 static int 754 ng_bridge_shutdown(node_p node) 755 { 756 const priv_p priv = NG_NODE_PRIVATE(node); 757 758 /* 759 * Shut down everything including the timer. Even if the 760 * callout has already been dequeued and is about to be 761 * run, ng_bridge_timeout() won't be fired as the node 762 * is already marked NGF_INVALID, so we're safe to free 763 * the node now. 764 */ 765 KASSERT(priv->numLinks == 0 && priv->numHosts == 0, 766 ("%s: numLinks=%d numHosts=%d", 767 __func__, priv->numLinks, priv->numHosts)); 768 ng_uncallout(&priv->timer, node); 769 NG_NODE_SET_PRIVATE(node, NULL); 770 NG_NODE_UNREF(node); 771 kfree(priv->tab, M_NETGRAPH_BRIDGE); 772 kfree(priv, M_NETGRAPH_BRIDGE); 773 return (0); 774 } 775 776 /* 777 * Hook disconnection. 778 */ 779 static int 780 ng_bridge_disconnect(hook_p hook) 781 { 782 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); 783 int linkNum; 784 785 /* Get link number */ 786 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook); 787 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 788 ("%s: linkNum=%u", __func__, linkNum)); 789 790 /* Remove all hosts associated with this link */ 791 ng_bridge_remove_hosts(priv, linkNum); 792 793 /* Free associated link information */ 794 KASSERT(priv->links[linkNum] != NULL, ("%s: no link", __func__)); 795 kfree(priv->links[linkNum], M_NETGRAPH_BRIDGE); 796 priv->links[linkNum] = NULL; 797 priv->numLinks--; 798 799 /* If no more hooks, go away */ 800 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) 801 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) { 802 ng_rmnode_self(NG_HOOK_NODE(hook)); 803 } 804 return (0); 805 } 806 807 /****************************************************************** 808 HASH TABLE FUNCTIONS 809 ******************************************************************/ 810 811 /* 812 * Hash algorithm 813 */ 814 #define HASH(addr,mask) ( (((const u_int16_t *)(addr))[0] \ 815 ^ ((const u_int16_t *)(addr))[1] \ 816 ^ ((const u_int16_t *)(addr))[2]) & (mask) ) 817 818 /* 819 * Find a host entry in the table. 820 */ 821 static struct ng_bridge_host * 822 ng_bridge_get(priv_p priv, const u_char *addr) 823 { 824 const int bucket = HASH(addr, priv->hashMask); 825 struct ng_bridge_hent *hent; 826 827 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 828 if (ETHER_EQUAL(hent->host.addr, addr)) 829 return (&hent->host); 830 } 831 return (NULL); 832 } 833 834 /* 835 * Add a new host entry to the table. This assumes the host doesn't 836 * already exist in the table. Returns 1 on success, 0 if there 837 * was a memory allocation failure. 838 */ 839 static int 840 ng_bridge_put(priv_p priv, const u_char *addr, int linkNum) 841 { 842 const int bucket = HASH(addr, priv->hashMask); 843 struct ng_bridge_hent *hent; 844 char ethstr[ETHER_ADDRSTRLEN + 1] __debugvar; 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 %s exists in table", __func__, kether_ntoa(addr, ethstr))); 851 } 852 #endif 853 854 /* Allocate and initialize new hashtable entry */ 855 hent = kmalloc(sizeof(*hent), M_NETGRAPH_BRIDGE, M_WAITOK | M_NULLOK); 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 = kmalloc(newNumBuckets * sizeof(*newTab), M_NETGRAPH_BRIDGE, 900 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 kfree(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 kfree(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 char ethstr[ETHER_ADDRSTRLEN + 1] __debugvar; 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 %s on nonexistent link %d", 985 __func__, kether_ntoa(hent->host.addr, ethstr), 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 kfree(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 ksnprintf(name, sizeof(name), "%s", NG_NODE_NAME(node)); 1041 else 1042 ksnprintf(name, sizeof(name), "[%x]", ng_node2ID(node)); 1043 return name; 1044 } 1045 1046