ng_bridge.c revision 184205
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: head/sys/netgraph/ng_bridge.c 184205 2008-10-23 15:53:51Z des $ 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#include <sys/vimage.h> 71 72#include <net/if.h> 73#include <net/ethernet.h> 74 75#include <netinet/in.h> 76#include <netinet/ip_fw.h> 77 78#include <netgraph/ng_message.h> 79#include <netgraph/netgraph.h> 80#include <netgraph/ng_parse.h> 81#include <netgraph/ng_bridge.h> 82 83#ifdef NG_SEPARATE_MALLOC 84MALLOC_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 */ 90struct 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 */ 97struct 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}; 108typedef struct ng_bridge_private *priv_p; 109 110/* Information about a host, stored in a hash table entry */ 111struct 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 */ 117SLIST_HEAD(ng_bridge_bucket, ng_bridge_hent); 118 119/* Netgraph node methods */ 120static ng_constructor_t ng_bridge_constructor; 121static ng_rcvmsg_t ng_bridge_rcvmsg; 122static ng_shutdown_t ng_bridge_shutdown; 123static ng_newhook_t ng_bridge_newhook; 124static ng_rcvdata_t ng_bridge_rcvdata; 125static ng_disconnect_t ng_bridge_disconnect; 126 127/* Other internal functions */ 128static struct ng_bridge_host *ng_bridge_get(priv_p priv, const u_char *addr); 129static int ng_bridge_put(priv_p priv, const u_char *addr, int linkNum); 130static void ng_bridge_rehash(priv_p priv); 131static void ng_bridge_remove_hosts(priv_p priv, int linkNum); 132static void ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2); 133static const char *ng_bridge_nodename(node_p node); 134 135/* Ethernet broadcast */ 136static 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 */ 164static int 165ng_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 */ 175static const struct ng_parse_struct_field ng_bridge_host_type_fields[] 176 = NG_BRIDGE_HOST_TYPE_INFO(&ng_parse_enaddr_type); 177static const struct ng_parse_type ng_bridge_host_type = { 178 &ng_parse_struct_type, 179 &ng_bridge_host_type_fields 180}; 181static const struct ng_parse_array_info ng_bridge_hary_type_info = { 182 &ng_bridge_host_type, 183 ng_bridge_getTableLength 184}; 185static const struct ng_parse_type ng_bridge_hary_type = { 186 &ng_parse_array_type, 187 &ng_bridge_hary_type_info 188}; 189static const struct ng_parse_struct_field ng_bridge_host_ary_type_fields[] 190 = NG_BRIDGE_HOST_ARY_TYPE_INFO(&ng_bridge_hary_type); 191static 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 */ 197static const struct ng_parse_fixedarray_info ng_bridge_ipfwary_type_info = { 198 &ng_parse_uint8_type, 199 NG_BRIDGE_MAX_LINKS 200}; 201static const struct ng_parse_type ng_bridge_ipfwary_type = { 202 &ng_parse_fixedarray_type, 203 &ng_bridge_ipfwary_type_info 204}; 205static const struct ng_parse_struct_field ng_bridge_config_type_fields[] 206 = NG_BRIDGE_CONFIG_TYPE_INFO(&ng_bridge_ipfwary_type); 207static 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 */ 213static const struct ng_parse_struct_field ng_bridge_stats_type_fields[] 214 = NG_BRIDGE_STATS_TYPE_INFO; 215static 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 */ 221static 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 */ 275static 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}; 286NETGRAPH_INIT(bridge, &ng_bridge_typestruct); 287 288/****************************************************************** 289 NETGRAPH NODE METHODS 290******************************************************************/ 291 292/* 293 * Node constructor 294 */ 295static int 296ng_bridge_constructor(node_p node) 297{ 298 priv_p priv; 299 300 /* Allocate and initialize private info */ 301 priv = malloc(sizeof(*priv), M_NETGRAPH_BRIDGE, M_NOWAIT | 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 = malloc( MIN_BUCKETS * sizeof(*priv->tab), M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO); 308 if (priv->tab == NULL) { 309 free(priv, M_NETGRAPH_BRIDGE); 310 return (ENOMEM); 311 } 312 priv->numBuckets = MIN_BUCKETS; 313 priv->hashMask = MIN_BUCKETS - 1; 314 priv->conf.debugLevel = 1; 315 priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT; 316 priv->conf.maxStaleness = DEFAULT_MAX_STALENESS; 317 priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE; 318 319 /* 320 * This node has all kinds of stuff that could be screwed by SMP. 321 * Until it gets it's own internal protection, we go through in 322 * single file. This could hurt a machine bridging beteen two 323 * GB ethernets so it should be fixed. 324 * When it's fixed the process SHOULD NOT SLEEP, spinlocks please! 325 * (and atomic ops ) 326 */ 327 NG_NODE_FORCE_WRITER(node); 328 NG_NODE_SET_PRIVATE(node, priv); 329 priv->node = node; 330 331 /* Start timer; timer is always running while node is alive */ 332 ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0); 333 334 /* Done */ 335 return (0); 336} 337 338/* 339 * Method for attaching a new hook 340 */ 341static int 342ng_bridge_newhook(node_p node, hook_p hook, const char *name) 343{ 344 const priv_p priv = NG_NODE_PRIVATE(node); 345 346 /* Check for a link hook */ 347 if (strncmp(name, NG_BRIDGE_HOOK_LINK_PREFIX, 348 strlen(NG_BRIDGE_HOOK_LINK_PREFIX)) == 0) { 349 const char *cp; 350 char *eptr; 351 u_long linkNum; 352 353 cp = name + strlen(NG_BRIDGE_HOOK_LINK_PREFIX); 354 if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0')) 355 return (EINVAL); 356 linkNum = strtoul(cp, &eptr, 10); 357 if (*eptr != '\0' || linkNum >= NG_BRIDGE_MAX_LINKS) 358 return (EINVAL); 359 if (priv->links[linkNum] != NULL) 360 return (EISCONN); 361 priv->links[linkNum] = malloc( sizeof(*priv->links[linkNum]), M_NETGRAPH_BRIDGE, M_NOWAIT|M_ZERO); 362 if (priv->links[linkNum] == NULL) 363 return (ENOMEM); 364 priv->links[linkNum]->hook = hook; 365 NG_HOOK_SET_PRIVATE(hook, (void *)linkNum); 366 priv->numLinks++; 367 return (0); 368 } 369 370 /* Unknown hook name */ 371 return (EINVAL); 372} 373 374/* 375 * Receive a control message 376 */ 377static int 378ng_bridge_rcvmsg(node_p node, item_p item, hook_p lasthook) 379{ 380 const priv_p priv = NG_NODE_PRIVATE(node); 381 struct ng_mesg *resp = NULL; 382 int error = 0; 383 struct ng_mesg *msg; 384 385 NGI_GET_MSG(item, msg); 386 switch (msg->header.typecookie) { 387 case NGM_BRIDGE_COOKIE: 388 switch (msg->header.cmd) { 389 case NGM_BRIDGE_GET_CONFIG: 390 { 391 struct ng_bridge_config *conf; 392 393 NG_MKRESPONSE(resp, msg, 394 sizeof(struct ng_bridge_config), M_NOWAIT); 395 if (resp == NULL) { 396 error = ENOMEM; 397 break; 398 } 399 conf = (struct ng_bridge_config *)resp->data; 400 *conf = priv->conf; /* no sanity checking needed */ 401 break; 402 } 403 case NGM_BRIDGE_SET_CONFIG: 404 { 405 struct ng_bridge_config *conf; 406 int i; 407 408 if (msg->header.arglen 409 != sizeof(struct ng_bridge_config)) { 410 error = EINVAL; 411 break; 412 } 413 conf = (struct ng_bridge_config *)msg->data; 414 priv->conf = *conf; 415 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) 416 priv->conf.ipfw[i] = !!priv->conf.ipfw[i]; 417 break; 418 } 419 case NGM_BRIDGE_RESET: 420 { 421 int i; 422 423 /* Flush all entries in the hash table */ 424 ng_bridge_remove_hosts(priv, -1); 425 426 /* Reset all loop detection counters and stats */ 427 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) { 428 if (priv->links[i] == NULL) 429 continue; 430 priv->links[i]->loopCount = 0; 431 bzero(&priv->links[i]->stats, 432 sizeof(priv->links[i]->stats)); 433 } 434 break; 435 } 436 case NGM_BRIDGE_GET_STATS: 437 case NGM_BRIDGE_CLR_STATS: 438 case NGM_BRIDGE_GETCLR_STATS: 439 { 440 struct ng_bridge_link *link; 441 int linkNum; 442 443 /* Get link number */ 444 if (msg->header.arglen != sizeof(u_int32_t)) { 445 error = EINVAL; 446 break; 447 } 448 linkNum = *((u_int32_t *)msg->data); 449 if (linkNum < 0 || linkNum >= NG_BRIDGE_MAX_LINKS) { 450 error = EINVAL; 451 break; 452 } 453 if ((link = priv->links[linkNum]) == NULL) { 454 error = ENOTCONN; 455 break; 456 } 457 458 /* Get/clear stats */ 459 if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) { 460 NG_MKRESPONSE(resp, msg, 461 sizeof(link->stats), M_NOWAIT); 462 if (resp == NULL) { 463 error = ENOMEM; 464 break; 465 } 466 bcopy(&link->stats, 467 resp->data, sizeof(link->stats)); 468 } 469 if (msg->header.cmd != NGM_BRIDGE_GET_STATS) 470 bzero(&link->stats, sizeof(link->stats)); 471 break; 472 } 473 case NGM_BRIDGE_GET_TABLE: 474 { 475 struct ng_bridge_host_ary *ary; 476 struct ng_bridge_hent *hent; 477 int i = 0, bucket; 478 479 NG_MKRESPONSE(resp, msg, sizeof(*ary) 480 + (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT); 481 if (resp == NULL) { 482 error = ENOMEM; 483 break; 484 } 485 ary = (struct ng_bridge_host_ary *)resp->data; 486 ary->numHosts = priv->numHosts; 487 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 488 SLIST_FOREACH(hent, &priv->tab[bucket], next) 489 ary->hosts[i++] = hent->host; 490 } 491 break; 492 } 493 default: 494 error = EINVAL; 495 break; 496 } 497 break; 498 default: 499 error = EINVAL; 500 break; 501 } 502 503 /* Done */ 504 NG_RESPOND_MSG(error, node, item, resp); 505 NG_FREE_MSG(msg); 506 return (error); 507} 508 509/* 510 * Receive data on a hook 511 */ 512static int 513ng_bridge_rcvdata(hook_p hook, item_p item) 514{ 515 const node_p node = NG_HOOK_NODE(hook); 516 const priv_p priv = NG_NODE_PRIVATE(node); 517 struct ng_bridge_host *host; 518 struct ng_bridge_link *link; 519 struct ether_header *eh; 520 int error = 0, linkNum, linksSeen; 521 int manycast; 522 struct mbuf *m; 523 struct ng_bridge_link *firstLink; 524 525 NGI_GET_M(item, m); 526 /* Get link number */ 527 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook); 528 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 529 ("%s: linkNum=%u", __func__, linkNum)); 530 link = priv->links[linkNum]; 531 KASSERT(link != NULL, ("%s: link%d null", __func__, linkNum)); 532 533 /* Sanity check packet and pull up header */ 534 if (m->m_pkthdr.len < ETHER_HDR_LEN) { 535 link->stats.recvRunts++; 536 NG_FREE_ITEM(item); 537 NG_FREE_M(m); 538 return (EINVAL); 539 } 540 if (m->m_len < ETHER_HDR_LEN && !(m = m_pullup(m, ETHER_HDR_LEN))) { 541 link->stats.memoryFailures++; 542 NG_FREE_ITEM(item); 543 return (ENOBUFS); 544 } 545 eh = mtod(m, struct ether_header *); 546 if ((eh->ether_shost[0] & 1) != 0) { 547 link->stats.recvInvalid++; 548 NG_FREE_ITEM(item); 549 NG_FREE_M(m); 550 return (EINVAL); 551 } 552 553 /* Is link disabled due to a loopback condition? */ 554 if (link->loopCount != 0) { 555 link->stats.loopDrops++; 556 NG_FREE_ITEM(item); 557 NG_FREE_M(m); 558 return (ELOOP); /* XXX is this an appropriate error? */ 559 } 560 561 /* Update stats */ 562 link->stats.recvPackets++; 563 link->stats.recvOctets += m->m_pkthdr.len; 564 if ((manycast = (eh->ether_dhost[0] & 1)) != 0) { 565 if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) { 566 link->stats.recvBroadcasts++; 567 manycast = 2; 568 } else 569 link->stats.recvMulticasts++; 570 } 571 572 /* Look up packet's source Ethernet address in hashtable */ 573 if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) { 574 575 /* Update time since last heard from this host */ 576 host->staleness = 0; 577 578 /* Did host jump to a different link? */ 579 if (host->linkNum != linkNum) { 580 581 /* 582 * If the host's old link was recently established 583 * on the old link and it's already jumped to a new 584 * link, declare a loopback condition. 585 */ 586 if (host->age < priv->conf.minStableAge) { 587 588 /* Log the problem */ 589 if (priv->conf.debugLevel >= 2) { 590 struct ifnet *ifp = m->m_pkthdr.rcvif; 591 char suffix[32]; 592 593 if (ifp != NULL) 594 snprintf(suffix, sizeof(suffix), 595 " (%s)", ifp->if_xname); 596 else 597 *suffix = '\0'; 598 log(LOG_WARNING, "ng_bridge: %s:" 599 " loopback detected on %s%s\n", 600 ng_bridge_nodename(node), 601 NG_HOOK_NAME(hook), suffix); 602 } 603 604 /* Mark link as linka non grata */ 605 link->loopCount = priv->conf.loopTimeout; 606 link->stats.loopDetects++; 607 608 /* Forget all hosts on this link */ 609 ng_bridge_remove_hosts(priv, linkNum); 610 611 /* Drop packet */ 612 link->stats.loopDrops++; 613 NG_FREE_ITEM(item); 614 NG_FREE_M(m); 615 return (ELOOP); /* XXX appropriate? */ 616 } 617 618 /* Move host over to new link */ 619 host->linkNum = linkNum; 620 host->age = 0; 621 } 622 } else { 623 if (!ng_bridge_put(priv, eh->ether_shost, linkNum)) { 624 link->stats.memoryFailures++; 625 NG_FREE_ITEM(item); 626 NG_FREE_M(m); 627 return (ENOMEM); 628 } 629 } 630 631 /* Run packet through ipfw processing, if enabled */ 632#if 0 633 if (priv->conf.ipfw[linkNum] && V_fw_enable && ip_fw_chk_ptr != NULL) { 634 /* XXX not implemented yet */ 635 } 636#endif 637 638 /* 639 * If unicast and destination host known, deliver to host's link, 640 * unless it is the same link as the packet came in on. 641 */ 642 if (!manycast) { 643 644 /* Determine packet destination link */ 645 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) { 646 struct ng_bridge_link *const destLink 647 = priv->links[host->linkNum]; 648 649 /* If destination same as incoming link, do nothing */ 650 KASSERT(destLink != NULL, 651 ("%s: link%d null", __func__, host->linkNum)); 652 if (destLink == link) { 653 NG_FREE_ITEM(item); 654 NG_FREE_M(m); 655 return (0); 656 } 657 658 /* Deliver packet out the destination link */ 659 destLink->stats.xmitPackets++; 660 destLink->stats.xmitOctets += m->m_pkthdr.len; 661 NG_FWD_NEW_DATA(error, item, destLink->hook, m); 662 return (error); 663 } 664 665 /* Destination host is not known */ 666 link->stats.recvUnknown++; 667 } 668 669 /* Distribute unknown, multicast, broadcast pkts to all other links */ 670 firstLink = NULL; 671 for (linkNum = linksSeen = 0; linksSeen <= priv->numLinks; linkNum++) { 672 struct ng_bridge_link *destLink; 673 struct mbuf *m2 = NULL; 674 675 /* 676 * If we have checked all the links then now 677 * send the original on its reserved link 678 */ 679 if (linksSeen == priv->numLinks) { 680 /* If we never saw a good link, leave. */ 681 if (firstLink == NULL) { 682 NG_FREE_ITEM(item); 683 NG_FREE_M(m); 684 return (0); 685 } 686 destLink = firstLink; 687 } else { 688 destLink = priv->links[linkNum]; 689 if (destLink != NULL) 690 linksSeen++; 691 /* Skip incoming link and disconnected links */ 692 if (destLink == NULL || destLink == link) { 693 continue; 694 } 695 if (firstLink == NULL) { 696 /* 697 * This is the first usable link we have found. 698 * Reserve it for the originals. 699 * If we never find another we save a copy. 700 */ 701 firstLink = destLink; 702 continue; 703 } 704 705 /* 706 * It's usable link but not the reserved (first) one. 707 * Copy mbuf info for sending. 708 */ 709 m2 = m_dup(m, M_DONTWAIT); /* XXX m_copypacket() */ 710 if (m2 == NULL) { 711 link->stats.memoryFailures++; 712 NG_FREE_ITEM(item); 713 NG_FREE_M(m); 714 return (ENOBUFS); 715 } 716 } 717 718 /* Update stats */ 719 destLink->stats.xmitPackets++; 720 destLink->stats.xmitOctets += m->m_pkthdr.len; 721 switch (manycast) { 722 case 0: /* unicast */ 723 break; 724 case 1: /* multicast */ 725 destLink->stats.xmitMulticasts++; 726 break; 727 case 2: /* broadcast */ 728 destLink->stats.xmitBroadcasts++; 729 break; 730 } 731 732 /* Send packet */ 733 if (destLink == firstLink) { 734 /* 735 * If we've sent all the others, send the original 736 * on the first link we found. 737 */ 738 NG_FWD_NEW_DATA(error, item, destLink->hook, m); 739 break; /* always done last - not really needed. */ 740 } else { 741 NG_SEND_DATA_ONLY(error, destLink->hook, m2); 742 } 743 } 744 return (error); 745} 746 747/* 748 * Shutdown node 749 */ 750static int 751ng_bridge_shutdown(node_p node) 752{ 753 const priv_p priv = NG_NODE_PRIVATE(node); 754 755 /* 756 * Shut down everything including the timer. Even if the 757 * callout has already been dequeued and is about to be 758 * run, ng_bridge_timeout() won't be fired as the node 759 * is already marked NGF_INVALID, so we're safe to free 760 * the node now. 761 */ 762 KASSERT(priv->numLinks == 0 && priv->numHosts == 0, 763 ("%s: numLinks=%d numHosts=%d", 764 __func__, priv->numLinks, priv->numHosts)); 765 ng_uncallout(&priv->timer, node); 766 NG_NODE_SET_PRIVATE(node, NULL); 767 NG_NODE_UNREF(node); 768 free(priv->tab, M_NETGRAPH_BRIDGE); 769 free(priv, M_NETGRAPH_BRIDGE); 770 return (0); 771} 772 773/* 774 * Hook disconnection. 775 */ 776static int 777ng_bridge_disconnect(hook_p hook) 778{ 779 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); 780 int linkNum; 781 782 /* Get link number */ 783 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook); 784 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 785 ("%s: linkNum=%u", __func__, linkNum)); 786 787 /* Remove all hosts associated with this link */ 788 ng_bridge_remove_hosts(priv, linkNum); 789 790 /* Free associated link information */ 791 KASSERT(priv->links[linkNum] != NULL, ("%s: no link", __func__)); 792 free(priv->links[linkNum], M_NETGRAPH_BRIDGE); 793 priv->links[linkNum] = NULL; 794 priv->numLinks--; 795 796 /* If no more hooks, go away */ 797 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) 798 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) { 799 ng_rmnode_self(NG_HOOK_NODE(hook)); 800 } 801 return (0); 802} 803 804/****************************************************************** 805 HASH TABLE FUNCTIONS 806******************************************************************/ 807 808/* 809 * Hash algorithm 810 */ 811#define HASH(addr,mask) ( (((const u_int16_t *)(addr))[0] \ 812 ^ ((const u_int16_t *)(addr))[1] \ 813 ^ ((const u_int16_t *)(addr))[2]) & (mask) ) 814 815/* 816 * Find a host entry in the table. 817 */ 818static struct ng_bridge_host * 819ng_bridge_get(priv_p priv, const u_char *addr) 820{ 821 const int bucket = HASH(addr, priv->hashMask); 822 struct ng_bridge_hent *hent; 823 824 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 825 if (ETHER_EQUAL(hent->host.addr, addr)) 826 return (&hent->host); 827 } 828 return (NULL); 829} 830 831/* 832 * Add a new host entry to the table. This assumes the host doesn't 833 * already exist in the table. Returns 1 on success, 0 if there 834 * was a memory allocation failure. 835 */ 836static int 837ng_bridge_put(priv_p priv, const u_char *addr, int linkNum) 838{ 839 const int bucket = HASH(addr, priv->hashMask); 840 struct ng_bridge_hent *hent; 841 842#ifdef INVARIANTS 843 /* Assert that entry does not already exist in hashtable */ 844 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 845 KASSERT(!ETHER_EQUAL(hent->host.addr, addr), 846 ("%s: entry %6D exists in table", __func__, addr, ":")); 847 } 848#endif 849 850 /* Allocate and initialize new hashtable entry */ 851 hent = malloc( sizeof(*hent), M_NETGRAPH_BRIDGE, M_NOWAIT); 852 if (hent == NULL) 853 return (0); 854 bcopy(addr, hent->host.addr, ETHER_ADDR_LEN); 855 hent->host.linkNum = linkNum; 856 hent->host.staleness = 0; 857 hent->host.age = 0; 858 859 /* Add new element to hash bucket */ 860 SLIST_INSERT_HEAD(&priv->tab[bucket], hent, next); 861 priv->numHosts++; 862 863 /* Resize table if necessary */ 864 ng_bridge_rehash(priv); 865 return (1); 866} 867 868/* 869 * Resize the hash table. We try to maintain the number of buckets 870 * such that the load factor is in the range 0.25 to 1.0. 871 * 872 * If we can't get the new memory then we silently fail. This is OK 873 * because things will still work and we'll try again soon anyway. 874 */ 875static void 876ng_bridge_rehash(priv_p priv) 877{ 878 struct ng_bridge_bucket *newTab; 879 int oldBucket, newBucket; 880 int newNumBuckets; 881 u_int newMask; 882 883 /* Is table too full or too empty? */ 884 if (priv->numHosts > priv->numBuckets 885 && (priv->numBuckets << 1) <= MAX_BUCKETS) 886 newNumBuckets = priv->numBuckets << 1; 887 else if (priv->numHosts < (priv->numBuckets >> 2) 888 && (priv->numBuckets >> 2) >= MIN_BUCKETS) 889 newNumBuckets = priv->numBuckets >> 2; 890 else 891 return; 892 newMask = newNumBuckets - 1; 893 894 /* Allocate and initialize new table */ 895 newTab = malloc( newNumBuckets * sizeof(*newTab), M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO); 896 if (newTab == NULL) 897 return; 898 899 /* Move all entries from old table to new table */ 900 for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) { 901 struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket]; 902 903 while (!SLIST_EMPTY(oldList)) { 904 struct ng_bridge_hent *const hent 905 = SLIST_FIRST(oldList); 906 907 SLIST_REMOVE_HEAD(oldList, next); 908 newBucket = HASH(hent->host.addr, newMask); 909 SLIST_INSERT_HEAD(&newTab[newBucket], hent, next); 910 } 911 } 912 913 /* Replace old table with new one */ 914 if (priv->conf.debugLevel >= 3) { 915 log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n", 916 ng_bridge_nodename(priv->node), 917 priv->numBuckets, newNumBuckets); 918 } 919 free(priv->tab, M_NETGRAPH_BRIDGE); 920 priv->numBuckets = newNumBuckets; 921 priv->hashMask = newMask; 922 priv->tab = newTab; 923 return; 924} 925 926/****************************************************************** 927 MISC FUNCTIONS 928******************************************************************/ 929 930/* 931 * Remove all hosts associated with a specific link from the hashtable. 932 * If linkNum == -1, then remove all hosts in the table. 933 */ 934static void 935ng_bridge_remove_hosts(priv_p priv, int linkNum) 936{ 937 int bucket; 938 939 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 940 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 941 942 while (*hptr != NULL) { 943 struct ng_bridge_hent *const hent = *hptr; 944 945 if (linkNum == -1 || hent->host.linkNum == linkNum) { 946 *hptr = SLIST_NEXT(hent, next); 947 free(hent, M_NETGRAPH_BRIDGE); 948 priv->numHosts--; 949 } else 950 hptr = &SLIST_NEXT(hent, next); 951 } 952 } 953} 954 955/* 956 * Handle our once-per-second timeout event. We do two things: 957 * we decrement link->loopCount for those links being muted due to 958 * a detected loopback condition, and we remove any hosts from 959 * the hashtable whom we haven't heard from in a long while. 960 */ 961static void 962ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2) 963{ 964 const priv_p priv = NG_NODE_PRIVATE(node); 965 int bucket; 966 int counter = 0; 967 int linkNum; 968 969 /* Update host time counters and remove stale entries */ 970 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 971 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 972 973 while (*hptr != NULL) { 974 struct ng_bridge_hent *const hent = *hptr; 975 976 /* Make sure host's link really exists */ 977 KASSERT(priv->links[hent->host.linkNum] != NULL, 978 ("%s: host %6D on nonexistent link %d\n", 979 __func__, hent->host.addr, ":", 980 hent->host.linkNum)); 981 982 /* Remove hosts we haven't heard from in a while */ 983 if (++hent->host.staleness >= priv->conf.maxStaleness) { 984 *hptr = SLIST_NEXT(hent, next); 985 free(hent, M_NETGRAPH_BRIDGE); 986 priv->numHosts--; 987 } else { 988 if (hent->host.age < 0xffff) 989 hent->host.age++; 990 hptr = &SLIST_NEXT(hent, next); 991 counter++; 992 } 993 } 994 } 995 KASSERT(priv->numHosts == counter, 996 ("%s: hosts: %d != %d", __func__, priv->numHosts, counter)); 997 998 /* Decrease table size if necessary */ 999 ng_bridge_rehash(priv); 1000 1001 /* Decrease loop counter on muted looped back links */ 1002 for (counter = linkNum = 0; linkNum < NG_BRIDGE_MAX_LINKS; linkNum++) { 1003 struct ng_bridge_link *const link = priv->links[linkNum]; 1004 1005 if (link != NULL) { 1006 if (link->loopCount != 0) { 1007 link->loopCount--; 1008 if (link->loopCount == 0 1009 && priv->conf.debugLevel >= 2) { 1010 log(LOG_INFO, "ng_bridge: %s:" 1011 " restoring looped back link%d\n", 1012 ng_bridge_nodename(node), linkNum); 1013 } 1014 } 1015 counter++; 1016 } 1017 } 1018 KASSERT(priv->numLinks == counter, 1019 ("%s: links: %d != %d", __func__, priv->numLinks, counter)); 1020 1021 /* Register a new timeout, keeping the existing node reference */ 1022 ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0); 1023} 1024 1025/* 1026 * Return node's "name", even if it doesn't have one. 1027 */ 1028static const char * 1029ng_bridge_nodename(node_p node) 1030{ 1031 static char name[NG_NODESIZ]; 1032 1033 if (NG_NODE_NAME(node) != NULL) 1034 snprintf(name, sizeof(name), "%s", NG_NODE_NAME(node)); 1035 else 1036 snprintf(name, sizeof(name), "[%x]", ng_node2ID(node)); 1037 return name; 1038} 1039 1040