1 /* 2 * ng_bridge.c 3 */ 4 5 /*- 6 * Copyright (c) 2000 Whistle Communications, Inc. 7 * All rights reserved. 8 * 9 * Subject to the following obligations and disclaimer of warranty, use and 10 * redistribution of this software, in source or object code forms, with or 11 * without modifications are expressly permitted by Whistle Communications; 12 * provided, however, that: 13 * 1. Any and all reproductions of the source or object code must include the 14 * copyright notice above and the following disclaimer of warranties; and 15 * 2. No rights are granted, in any manner or form, to use Whistle 16 * Communications, Inc. trademarks, including the mark "WHISTLE 17 * COMMUNICATIONS" on advertising, endorsements, or otherwise except as 18 * such appears in the above copyright notice or in the software. 19 * 20 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND 21 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO 22 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE, 23 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF 24 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. 25 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY 26 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS 27 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE. 28 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES 29 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING 30 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 31 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR 32 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY 33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 35 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY 36 * OF SUCH DAMAGE. 37 * 38 * Author: Archie Cobbs <archie@freebsd.org> 39 * 40 * $FreeBSD$ 41 */ 42 43 /* 44 * ng_bridge(4) netgraph node type 45 * 46 * The node performs standard intelligent Ethernet bridging over 47 * each of its connected hooks, or links. A simple loop detection 48 * algorithm is included which disables a link for priv->conf.loopTimeout 49 * seconds when a host is seen to have jumped from one link to 50 * another within priv->conf.minStableAge seconds. 51 * 52 * We keep a hashtable that maps Ethernet addresses to host info, 53 * which is contained in struct ng_bridge_host's. These structures 54 * tell us on which link the host may be found. A host's entry will 55 * expire after priv->conf.maxStaleness seconds. 56 * 57 * This node is optimzed for stable networks, where machines jump 58 * from one port to the other only rarely. 59 */ 60 61 #include <sys/param.h> 62 #include <sys/systm.h> 63 #include <sys/kernel.h> 64 #include <sys/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 <netinet/ip_fw.h> 76 77 #include <netgraph/ng_message.h> 78 #include <netgraph/netgraph.h> 79 #include <netgraph/ng_parse.h> 80 #include <netgraph/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 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO); 301 if (priv == NULL) 302 return (ENOMEM); 303 ng_callout_init(&priv->timer); 304 305 /* Allocate and initialize hash table, etc. */ 306 MALLOC(priv->tab, struct ng_bridge_bucket *, 307 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 */ 341 static int 342 ng_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 MALLOC(priv->links[linkNum], struct ng_bridge_link *, 362 sizeof(*priv->links[linkNum]), M_NETGRAPH_BRIDGE, M_NOWAIT|M_ZERO); 363 if (priv->links[linkNum] == NULL) 364 return (ENOMEM); 365 priv->links[linkNum]->hook = hook; 366 NG_HOOK_SET_PRIVATE(hook, (void *)linkNum); 367 priv->numLinks++; 368 return (0); 369 } 370 371 /* Unknown hook name */ 372 return (EINVAL); 373 } 374 375 /* 376 * Receive a control message 377 */ 378 static int 379 ng_bridge_rcvmsg(node_p node, item_p item, hook_p lasthook) 380 { 381 const priv_p priv = NG_NODE_PRIVATE(node); 382 struct ng_mesg *resp = NULL; 383 int error = 0; 384 struct ng_mesg *msg; 385 386 NGI_GET_MSG(item, msg); 387 switch (msg->header.typecookie) { 388 case NGM_BRIDGE_COOKIE: 389 switch (msg->header.cmd) { 390 case NGM_BRIDGE_GET_CONFIG: 391 { 392 struct ng_bridge_config *conf; 393 394 NG_MKRESPONSE(resp, msg, 395 sizeof(struct ng_bridge_config), M_NOWAIT); 396 if (resp == NULL) { 397 error = ENOMEM; 398 break; 399 } 400 conf = (struct ng_bridge_config *)resp->data; 401 *conf = priv->conf; /* no sanity checking needed */ 402 break; 403 } 404 case NGM_BRIDGE_SET_CONFIG: 405 { 406 struct ng_bridge_config *conf; 407 int i; 408 409 if (msg->header.arglen 410 != sizeof(struct ng_bridge_config)) { 411 error = EINVAL; 412 break; 413 } 414 conf = (struct ng_bridge_config *)msg->data; 415 priv->conf = *conf; 416 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) 417 priv->conf.ipfw[i] = !!priv->conf.ipfw[i]; 418 break; 419 } 420 case NGM_BRIDGE_RESET: 421 { 422 int i; 423 424 /* Flush all entries in the hash table */ 425 ng_bridge_remove_hosts(priv, -1); 426 427 /* Reset all loop detection counters and stats */ 428 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) { 429 if (priv->links[i] == NULL) 430 continue; 431 priv->links[i]->loopCount = 0; 432 bzero(&priv->links[i]->stats, 433 sizeof(priv->links[i]->stats)); 434 } 435 break; 436 } 437 case NGM_BRIDGE_GET_STATS: 438 case NGM_BRIDGE_CLR_STATS: 439 case NGM_BRIDGE_GETCLR_STATS: 440 { 441 struct ng_bridge_link *link; 442 int linkNum; 443 444 /* Get link number */ 445 if (msg->header.arglen != sizeof(u_int32_t)) { 446 error = EINVAL; 447 break; 448 } 449 linkNum = *((u_int32_t *)msg->data); 450 if (linkNum < 0 || linkNum >= NG_BRIDGE_MAX_LINKS) { 451 error = EINVAL; 452 break; 453 } 454 if ((link = priv->links[linkNum]) == NULL) { 455 error = ENOTCONN; 456 break; 457 } 458 459 /* Get/clear stats */ 460 if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) { 461 NG_MKRESPONSE(resp, msg, 462 sizeof(link->stats), M_NOWAIT); 463 if (resp == NULL) { 464 error = ENOMEM; 465 break; 466 } 467 bcopy(&link->stats, 468 resp->data, sizeof(link->stats)); 469 } 470 if (msg->header.cmd != NGM_BRIDGE_GET_STATS) 471 bzero(&link->stats, sizeof(link->stats)); 472 break; 473 } 474 case NGM_BRIDGE_GET_TABLE: 475 { 476 struct ng_bridge_host_ary *ary; 477 struct ng_bridge_hent *hent; 478 int i = 0, bucket; 479 480 NG_MKRESPONSE(resp, msg, sizeof(*ary) 481 + (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT); 482 if (resp == NULL) { 483 error = ENOMEM; 484 break; 485 } 486 ary = (struct ng_bridge_host_ary *)resp->data; 487 ary->numHosts = priv->numHosts; 488 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 489 SLIST_FOREACH(hent, &priv->tab[bucket], next) 490 ary->hosts[i++] = hent->host; 491 } 492 break; 493 } 494 default: 495 error = EINVAL; 496 break; 497 } 498 break; 499 default: 500 error = EINVAL; 501 break; 502 } 503 504 /* Done */ 505 NG_RESPOND_MSG(error, node, item, resp); 506 NG_FREE_MSG(msg); 507 return (error); 508 } 509 510 /* 511 * Receive data on a hook 512 */ 513 static int 514 ng_bridge_rcvdata(hook_p hook, item_p item) 515 { 516 const node_p node = NG_HOOK_NODE(hook); 517 const priv_p priv = NG_NODE_PRIVATE(node); 518 struct ng_bridge_host *host; 519 struct ng_bridge_link *link; 520 struct ether_header *eh; 521 int error = 0, linkNum, linksSeen; 522 int manycast; 523 struct mbuf *m; 524 struct ng_bridge_link *firstLink; 525 526 NGI_GET_M(item, m); 527 /* Get link number */ 528 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook); 529 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 530 ("%s: linkNum=%u", __func__, linkNum)); 531 link = priv->links[linkNum]; 532 KASSERT(link != NULL, ("%s: link%d null", __func__, linkNum)); 533 534 /* Sanity check packet and pull up header */ 535 if (m->m_pkthdr.len < ETHER_HDR_LEN) { 536 link->stats.recvRunts++; 537 NG_FREE_ITEM(item); 538 NG_FREE_M(m); 539 return (EINVAL); 540 } 541 if (m->m_len < ETHER_HDR_LEN && !(m = m_pullup(m, ETHER_HDR_LEN))) { 542 link->stats.memoryFailures++; 543 NG_FREE_ITEM(item); 544 return (ENOBUFS); 545 } 546 eh = mtod(m, struct ether_header *); 547 if ((eh->ether_shost[0] & 1) != 0) { 548 link->stats.recvInvalid++; 549 NG_FREE_ITEM(item); 550 NG_FREE_M(m); 551 return (EINVAL); 552 } 553 554 /* Is link disabled due to a loopback condition? */ 555 if (link->loopCount != 0) { 556 link->stats.loopDrops++; 557 NG_FREE_ITEM(item); 558 NG_FREE_M(m); 559 return (ELOOP); /* XXX is this an appropriate error? */ 560 } 561 562 /* Update stats */ 563 link->stats.recvPackets++; 564 link->stats.recvOctets += m->m_pkthdr.len; 565 if ((manycast = (eh->ether_dhost[0] & 1)) != 0) { 566 if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) { 567 link->stats.recvBroadcasts++; 568 manycast = 2; 569 } else 570 link->stats.recvMulticasts++; 571 } 572 573 /* Look up packet's source Ethernet address in hashtable */ 574 if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) { 575 576 /* Update time since last heard from this host */ 577 host->staleness = 0; 578 579 /* Did host jump to a different link? */ 580 if (host->linkNum != linkNum) { 581 582 /* 583 * If the host's old link was recently established 584 * on the old link and it's already jumped to a new 585 * link, declare a loopback condition. 586 */ 587 if (host->age < priv->conf.minStableAge) { 588 589 /* Log the problem */ 590 if (priv->conf.debugLevel >= 2) { 591 struct ifnet *ifp = m->m_pkthdr.rcvif; 592 char suffix[32]; 593 594 if (ifp != NULL) 595 snprintf(suffix, sizeof(suffix), 596 " (%s)", ifp->if_xname); 597 else 598 *suffix = '\0'; 599 log(LOG_WARNING, "ng_bridge: %s:" 600 " loopback detected on %s%s\n", 601 ng_bridge_nodename(node), 602 NG_HOOK_NAME(hook), suffix); 603 } 604 605 /* Mark link as linka non grata */ 606 link->loopCount = priv->conf.loopTimeout; 607 link->stats.loopDetects++; 608 609 /* Forget all hosts on this link */ 610 ng_bridge_remove_hosts(priv, linkNum); 611 612 /* Drop packet */ 613 link->stats.loopDrops++; 614 NG_FREE_ITEM(item); 615 NG_FREE_M(m); 616 return (ELOOP); /* XXX appropriate? */ 617 } 618 619 /* Move host over to new link */ 620 host->linkNum = linkNum; 621 host->age = 0; 622 } 623 } else { 624 if (!ng_bridge_put(priv, eh->ether_shost, linkNum)) { 625 link->stats.memoryFailures++; 626 NG_FREE_ITEM(item); 627 NG_FREE_M(m); 628 return (ENOMEM); 629 } 630 } 631 632 /* Run packet through ipfw processing, if enabled */ 633 #if 0 634 if (priv->conf.ipfw[linkNum] && fw_enable && ip_fw_chk_ptr != NULL) { 635 /* XXX not implemented yet */ 636 } 637 #endif 638 639 /* 640 * If unicast and destination host known, deliver to host's link, 641 * unless it is the same link as the packet came in on. 642 */ 643 if (!manycast) { 644 645 /* Determine packet destination link */ 646 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) { 647 struct ng_bridge_link *const destLink 648 = priv->links[host->linkNum]; 649 650 /* If destination same as incoming link, do nothing */ 651 KASSERT(destLink != NULL, 652 ("%s: link%d null", __func__, host->linkNum)); 653 if (destLink == link) { 654 NG_FREE_ITEM(item); 655 NG_FREE_M(m); 656 return (0); 657 } 658 659 /* Deliver packet out the destination link */ 660 destLink->stats.xmitPackets++; 661 destLink->stats.xmitOctets += m->m_pkthdr.len; 662 NG_FWD_NEW_DATA(error, item, destLink->hook, m); 663 return (error); 664 } 665 666 /* Destination host is not known */ 667 link->stats.recvUnknown++; 668 } 669 670 /* Distribute unknown, multicast, broadcast pkts to all other links */ 671 firstLink = NULL; 672 for (linkNum = linksSeen = 0; linksSeen <= priv->numLinks; linkNum++) { 673 struct ng_bridge_link *destLink; 674 struct mbuf *m2 = NULL; 675 676 /* 677 * If we have checked all the links then now 678 * send the original on its reserved link 679 */ 680 if (linksSeen == priv->numLinks) { 681 /* If we never saw a good link, leave. */ 682 if (firstLink == NULL) { 683 NG_FREE_ITEM(item); 684 NG_FREE_M(m); 685 return (0); 686 } 687 destLink = firstLink; 688 } else { 689 destLink = priv->links[linkNum]; 690 if (destLink != NULL) 691 linksSeen++; 692 /* Skip incoming link and disconnected links */ 693 if (destLink == NULL || destLink == link) { 694 continue; 695 } 696 if (firstLink == NULL) { 697 /* 698 * This is the first usable link we have found. 699 * Reserve it for the originals. 700 * If we never find another we save a copy. 701 */ 702 firstLink = destLink; 703 continue; 704 } 705 706 /* 707 * It's usable link but not the reserved (first) one. 708 * Copy mbuf info for sending. 709 */ 710 m2 = m_dup(m, M_DONTWAIT); /* XXX m_copypacket() */ 711 if (m2 == NULL) { 712 link->stats.memoryFailures++; 713 NG_FREE_ITEM(item); 714 NG_FREE_M(m); 715 return (ENOBUFS); 716 } 717 } 718 719 /* Update stats */ 720 destLink->stats.xmitPackets++; 721 destLink->stats.xmitOctets += m->m_pkthdr.len; 722 switch (manycast) { 723 case 0: /* unicast */ 724 break; 725 case 1: /* multicast */ 726 destLink->stats.xmitMulticasts++; 727 break; 728 case 2: /* broadcast */ 729 destLink->stats.xmitBroadcasts++; 730 break; 731 } 732 733 /* Send packet */ 734 if (destLink == firstLink) { 735 /* 736 * If we've sent all the others, send the original 737 * on the first link we found. 738 */ 739 NG_FWD_NEW_DATA(error, item, destLink->hook, m); 740 break; /* always done last - not really needed. */ 741 } else { 742 NG_SEND_DATA_ONLY(error, destLink->hook, m2); 743 } 744 } 745 return (error); 746 } 747 748 /* 749 * Shutdown node 750 */ 751 static int 752 ng_bridge_shutdown(node_p node) 753 { 754 const priv_p priv = NG_NODE_PRIVATE(node); 755 756 /* 757 * Shut down everything including the timer. Even if the 758 * callout has already been dequeued and is about to be 759 * run, ng_bridge_timeout() won't be fired as the node 760 * is already marked NGF_INVALID, so we're safe to free 761 * the node now. 762 */ 763 KASSERT(priv->numLinks == 0 && priv->numHosts == 0, 764 ("%s: numLinks=%d numHosts=%d", 765 __func__, priv->numLinks, priv->numHosts)); 766 ng_uncallout(&priv->timer, node); 767 NG_NODE_SET_PRIVATE(node, NULL); 768 NG_NODE_UNREF(node); 769 FREE(priv->tab, M_NETGRAPH_BRIDGE); 770 FREE(priv, M_NETGRAPH_BRIDGE); 771 return (0); 772 } 773 774 /* 775 * Hook disconnection. 776 */ 777 static int 778 ng_bridge_disconnect(hook_p hook) 779 { 780 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); 781 int linkNum; 782 783 /* Get link number */ 784 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook); 785 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 786 ("%s: linkNum=%u", __func__, linkNum)); 787 788 /* Remove all hosts associated with this link */ 789 ng_bridge_remove_hosts(priv, linkNum); 790 791 /* Free associated link information */ 792 KASSERT(priv->links[linkNum] != NULL, ("%s: no link", __func__)); 793 FREE(priv->links[linkNum], M_NETGRAPH_BRIDGE); 794 priv->links[linkNum] = NULL; 795 priv->numLinks--; 796 797 /* If no more hooks, go away */ 798 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) 799 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) { 800 ng_rmnode_self(NG_HOOK_NODE(hook)); 801 } 802 return (0); 803 } 804 805 /****************************************************************** 806 HASH TABLE FUNCTIONS 807 ******************************************************************/ 808 809 /* 810 * Hash algorithm 811 */ 812 #define HASH(addr,mask) ( (((const u_int16_t *)(addr))[0] \ 813 ^ ((const u_int16_t *)(addr))[1] \ 814 ^ ((const u_int16_t *)(addr))[2]) & (mask) ) 815 816 /* 817 * Find a host entry in the table. 818 */ 819 static struct ng_bridge_host * 820 ng_bridge_get(priv_p priv, const u_char *addr) 821 { 822 const int bucket = HASH(addr, priv->hashMask); 823 struct ng_bridge_hent *hent; 824 825 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 826 if (ETHER_EQUAL(hent->host.addr, addr)) 827 return (&hent->host); 828 } 829 return (NULL); 830 } 831 832 /* 833 * Add a new host entry to the table. This assumes the host doesn't 834 * already exist in the table. Returns 1 on success, 0 if there 835 * was a memory allocation failure. 836 */ 837 static int 838 ng_bridge_put(priv_p priv, const u_char *addr, int linkNum) 839 { 840 const int bucket = HASH(addr, priv->hashMask); 841 struct ng_bridge_hent *hent; 842 843 #ifdef INVARIANTS 844 /* Assert that entry does not already exist in hashtable */ 845 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 846 KASSERT(!ETHER_EQUAL(hent->host.addr, addr), 847 ("%s: entry %6D exists in table", __func__, addr, ":")); 848 } 849 #endif 850 851 /* Allocate and initialize new hashtable entry */ 852 MALLOC(hent, struct ng_bridge_hent *, 853 sizeof(*hent), M_NETGRAPH_BRIDGE, M_NOWAIT); 854 if (hent == NULL) 855 return (0); 856 bcopy(addr, hent->host.addr, ETHER_ADDR_LEN); 857 hent->host.linkNum = linkNum; 858 hent->host.staleness = 0; 859 hent->host.age = 0; 860 861 /* Add new element to hash bucket */ 862 SLIST_INSERT_HEAD(&priv->tab[bucket], hent, next); 863 priv->numHosts++; 864 865 /* Resize table if necessary */ 866 ng_bridge_rehash(priv); 867 return (1); 868 } 869 870 /* 871 * Resize the hash table. We try to maintain the number of buckets 872 * such that the load factor is in the range 0.25 to 1.0. 873 * 874 * If we can't get the new memory then we silently fail. This is OK 875 * because things will still work and we'll try again soon anyway. 876 */ 877 static void 878 ng_bridge_rehash(priv_p priv) 879 { 880 struct ng_bridge_bucket *newTab; 881 int oldBucket, newBucket; 882 int newNumBuckets; 883 u_int newMask; 884 885 /* Is table too full or too empty? */ 886 if (priv->numHosts > priv->numBuckets 887 && (priv->numBuckets << 1) <= MAX_BUCKETS) 888 newNumBuckets = priv->numBuckets << 1; 889 else if (priv->numHosts < (priv->numBuckets >> 2) 890 && (priv->numBuckets >> 2) >= MIN_BUCKETS) 891 newNumBuckets = priv->numBuckets >> 2; 892 else 893 return; 894 newMask = newNumBuckets - 1; 895 896 /* Allocate and initialize new table */ 897 MALLOC(newTab, struct ng_bridge_bucket *, 898 newNumBuckets * sizeof(*newTab), M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO); 899 if (newTab == NULL) 900 return; 901 902 /* Move all entries from old table to new table */ 903 for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) { 904 struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket]; 905 906 while (!SLIST_EMPTY(oldList)) { 907 struct ng_bridge_hent *const hent 908 = SLIST_FIRST(oldList); 909 910 SLIST_REMOVE_HEAD(oldList, next); 911 newBucket = HASH(hent->host.addr, newMask); 912 SLIST_INSERT_HEAD(&newTab[newBucket], hent, next); 913 } 914 } 915 916 /* Replace old table with new one */ 917 if (priv->conf.debugLevel >= 3) { 918 log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n", 919 ng_bridge_nodename(priv->node), 920 priv->numBuckets, newNumBuckets); 921 } 922 FREE(priv->tab, M_NETGRAPH_BRIDGE); 923 priv->numBuckets = newNumBuckets; 924 priv->hashMask = newMask; 925 priv->tab = newTab; 926 return; 927 } 928 929 /****************************************************************** 930 MISC FUNCTIONS 931 ******************************************************************/ 932 933 /* 934 * Remove all hosts associated with a specific link from the hashtable. 935 * If linkNum == -1, then remove all hosts in the table. 936 */ 937 static void 938 ng_bridge_remove_hosts(priv_p priv, int linkNum) 939 { 940 int bucket; 941 942 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 943 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 944 945 while (*hptr != NULL) { 946 struct ng_bridge_hent *const hent = *hptr; 947 948 if (linkNum == -1 || hent->host.linkNum == linkNum) { 949 *hptr = SLIST_NEXT(hent, next); 950 FREE(hent, M_NETGRAPH_BRIDGE); 951 priv->numHosts--; 952 } else 953 hptr = &SLIST_NEXT(hent, next); 954 } 955 } 956 } 957 958 /* 959 * Handle our once-per-second timeout event. We do two things: 960 * we decrement link->loopCount for those links being muted due to 961 * a detected loopback condition, and we remove any hosts from 962 * the hashtable whom we haven't heard from in a long while. 963 */ 964 static void 965 ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2) 966 { 967 const priv_p priv = NG_NODE_PRIVATE(node); 968 int bucket; 969 int counter = 0; 970 int linkNum; 971 972 /* Update host time counters and remove stale entries */ 973 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 974 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 975 976 while (*hptr != NULL) { 977 struct ng_bridge_hent *const hent = *hptr; 978 979 /* Make sure host's link really exists */ 980 KASSERT(priv->links[hent->host.linkNum] != NULL, 981 ("%s: host %6D on nonexistent link %d\n", 982 __func__, hent->host.addr, ":", 983 hent->host.linkNum)); 984 985 /* Remove hosts we haven't heard from in a while */ 986 if (++hent->host.staleness >= priv->conf.maxStaleness) { 987 *hptr = SLIST_NEXT(hent, next); 988 FREE(hent, M_NETGRAPH_BRIDGE); 989 priv->numHosts--; 990 } else { 991 if (hent->host.age < 0xffff) 992 hent->host.age++; 993 hptr = &SLIST_NEXT(hent, next); 994 counter++; 995 } 996 } 997 } 998 KASSERT(priv->numHosts == counter, 999 ("%s: hosts: %d != %d", __func__, priv->numHosts, counter)); 1000 1001 /* Decrease table size if necessary */ 1002 ng_bridge_rehash(priv); 1003 1004 /* Decrease loop counter on muted looped back links */ 1005 for (counter = linkNum = 0; linkNum < NG_BRIDGE_MAX_LINKS; linkNum++) { 1006 struct ng_bridge_link *const link = priv->links[linkNum]; 1007 1008 if (link != NULL) { 1009 if (link->loopCount != 0) { 1010 link->loopCount--; 1011 if (link->loopCount == 0 1012 && priv->conf.debugLevel >= 2) { 1013 log(LOG_INFO, "ng_bridge: %s:" 1014 " restoring looped back link%d\n", 1015 ng_bridge_nodename(node), linkNum); 1016 } 1017 } 1018 counter++; 1019 } 1020 } 1021 KASSERT(priv->numLinks == counter, 1022 ("%s: links: %d != %d", __func__, priv->numLinks, counter)); 1023 1024 /* Register a new timeout, keeping the existing node reference */ 1025 ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0); 1026 } 1027 1028 /* 1029 * Return node's "name", even if it doesn't have one. 1030 */ 1031 static const char * 1032 ng_bridge_nodename(node_p node) 1033 { 1034 static char name[NG_NODESIZ]; 1035 1036 if (NG_NODE_NAME(node) != NULL) 1037 snprintf(name, sizeof(name), "%s", NG_NODE_NAME(node)); 1038 else 1039 snprintf(name, sizeof(name), "[%x]", ng_node2ID(node)); 1040 return name; 1041 } 1042 1043