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 #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 84 MALLOC_DEFINE(M_NETGRAPH_BRIDGE, "netgraph_bridge", "netgraph bridge node "); 85 #else 86 #define M_NETGRAPH_BRIDGE M_NETGRAPH 87 #endif 88 89 /* Per-link private data */ 90 struct ng_bridge_link { 91 hook_p hook; /* netgraph hook */ 92 u_int16_t loopCount; /* loop ignore timer */ 93 struct ng_bridge_link_stats stats; /* link stats */ 94 }; 95 96 /* Per-node private data */ 97 struct ng_bridge_private { 98 struct ng_bridge_bucket *tab; /* hash table bucket array */ 99 struct ng_bridge_link *links[NG_BRIDGE_MAX_LINKS]; 100 struct ng_bridge_config conf; /* node configuration */ 101 node_p node; /* netgraph node */ 102 u_int numHosts; /* num entries in table */ 103 u_int numBuckets; /* num buckets in table */ 104 u_int hashMask; /* numBuckets - 1 */ 105 int numLinks; /* num connected links */ 106 struct callout timer; /* one second periodic timer */ 107 }; 108 typedef struct ng_bridge_private *priv_p; 109 110 /* Information about a host, stored in a hash table entry */ 111 struct ng_bridge_hent { 112 struct ng_bridge_host host; /* actual host info */ 113 SLIST_ENTRY(ng_bridge_hent) next; /* next entry in bucket */ 114 }; 115 116 /* Hash table bucket declaration */ 117 SLIST_HEAD(ng_bridge_bucket, ng_bridge_hent); 118 119 /* Netgraph node methods */ 120 static ng_constructor_t ng_bridge_constructor; 121 static ng_rcvmsg_t ng_bridge_rcvmsg; 122 static ng_shutdown_t ng_bridge_shutdown; 123 static ng_newhook_t ng_bridge_newhook; 124 static ng_rcvdata_t ng_bridge_rcvdata; 125 static ng_disconnect_t ng_bridge_disconnect; 126 127 /* Other internal functions */ 128 static struct ng_bridge_host *ng_bridge_get(priv_p priv, const u_char *addr); 129 static int ng_bridge_put(priv_p priv, const u_char *addr, int linkNum); 130 static void ng_bridge_rehash(priv_p priv); 131 static void ng_bridge_remove_hosts(priv_p priv, int linkNum); 132 static void ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2); 133 static const char *ng_bridge_nodename(node_p node); 134 135 /* Ethernet broadcast */ 136 static const u_char ng_bridge_bcast_addr[ETHER_ADDR_LEN] = 137 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; 138 139 /* Store each hook's link number in the private field */ 140 #define LINK_NUM(hook) (*(u_int16_t *)(&(hook)->private)) 141 142 /* Compare Ethernet addresses using 32 and 16 bit words instead of bytewise */ 143 #define ETHER_EQUAL(a,b) (((const u_int32_t *)(a))[0] \ 144 == ((const u_int32_t *)(b))[0] \ 145 && ((const u_int16_t *)(a))[2] \ 146 == ((const u_int16_t *)(b))[2]) 147 148 /* Minimum and maximum number of hash buckets. Must be a power of two. */ 149 #define MIN_BUCKETS (1 << 5) /* 32 */ 150 #define MAX_BUCKETS (1 << 14) /* 16384 */ 151 152 /* Configuration default values */ 153 #define DEFAULT_LOOP_TIMEOUT 60 154 #define DEFAULT_MAX_STALENESS (15 * 60) /* same as ARP timeout */ 155 #define DEFAULT_MIN_STABLE_AGE 1 156 157 /****************************************************************** 158 NETGRAPH PARSE TYPES 159 ******************************************************************/ 160 161 /* 162 * How to determine the length of the table returned by NGM_BRIDGE_GET_TABLE 163 */ 164 static int 165 ng_bridge_getTableLength(const struct ng_parse_type *type, 166 const u_char *start, const u_char *buf) 167 { 168 const struct ng_bridge_host_ary *const hary 169 = (const struct ng_bridge_host_ary *)(buf - sizeof(u_int32_t)); 170 171 return hary->numHosts; 172 } 173 174 /* Parse type for struct ng_bridge_host_ary */ 175 static const struct ng_parse_struct_field ng_bridge_host_type_fields[] 176 = NG_BRIDGE_HOST_TYPE_INFO(&ng_parse_enaddr_type); 177 static const struct ng_parse_type ng_bridge_host_type = { 178 &ng_parse_struct_type, 179 &ng_bridge_host_type_fields 180 }; 181 static const struct ng_parse_array_info ng_bridge_hary_type_info = { 182 &ng_bridge_host_type, 183 ng_bridge_getTableLength 184 }; 185 static const struct ng_parse_type ng_bridge_hary_type = { 186 &ng_parse_array_type, 187 &ng_bridge_hary_type_info 188 }; 189 static const struct ng_parse_struct_field ng_bridge_host_ary_type_fields[] 190 = NG_BRIDGE_HOST_ARY_TYPE_INFO(&ng_bridge_hary_type); 191 static const struct ng_parse_type ng_bridge_host_ary_type = { 192 &ng_parse_struct_type, 193 &ng_bridge_host_ary_type_fields 194 }; 195 196 /* Parse type for struct ng_bridge_config */ 197 static const struct ng_parse_fixedarray_info ng_bridge_ipfwary_type_info = { 198 &ng_parse_uint8_type, 199 NG_BRIDGE_MAX_LINKS 200 }; 201 static const struct ng_parse_type ng_bridge_ipfwary_type = { 202 &ng_parse_fixedarray_type, 203 &ng_bridge_ipfwary_type_info 204 }; 205 static const struct ng_parse_struct_field ng_bridge_config_type_fields[] 206 = NG_BRIDGE_CONFIG_TYPE_INFO(&ng_bridge_ipfwary_type); 207 static const struct ng_parse_type ng_bridge_config_type = { 208 &ng_parse_struct_type, 209 &ng_bridge_config_type_fields 210 }; 211 212 /* Parse type for struct ng_bridge_link_stat */ 213 static const struct ng_parse_struct_field ng_bridge_stats_type_fields[] 214 = NG_BRIDGE_STATS_TYPE_INFO; 215 static const struct ng_parse_type ng_bridge_stats_type = { 216 &ng_parse_struct_type, 217 &ng_bridge_stats_type_fields 218 }; 219 220 /* List of commands and how to convert arguments to/from ASCII */ 221 static const struct ng_cmdlist ng_bridge_cmdlist[] = { 222 { 223 NGM_BRIDGE_COOKIE, 224 NGM_BRIDGE_SET_CONFIG, 225 "setconfig", 226 &ng_bridge_config_type, 227 NULL 228 }, 229 { 230 NGM_BRIDGE_COOKIE, 231 NGM_BRIDGE_GET_CONFIG, 232 "getconfig", 233 NULL, 234 &ng_bridge_config_type 235 }, 236 { 237 NGM_BRIDGE_COOKIE, 238 NGM_BRIDGE_RESET, 239 "reset", 240 NULL, 241 NULL 242 }, 243 { 244 NGM_BRIDGE_COOKIE, 245 NGM_BRIDGE_GET_STATS, 246 "getstats", 247 &ng_parse_uint32_type, 248 &ng_bridge_stats_type 249 }, 250 { 251 NGM_BRIDGE_COOKIE, 252 NGM_BRIDGE_CLR_STATS, 253 "clrstats", 254 &ng_parse_uint32_type, 255 NULL 256 }, 257 { 258 NGM_BRIDGE_COOKIE, 259 NGM_BRIDGE_GETCLR_STATS, 260 "getclrstats", 261 &ng_parse_uint32_type, 262 &ng_bridge_stats_type 263 }, 264 { 265 NGM_BRIDGE_COOKIE, 266 NGM_BRIDGE_GET_TABLE, 267 "gettable", 268 NULL, 269 &ng_bridge_host_ary_type 270 }, 271 { 0 } 272 }; 273 274 /* Node type descriptor */ 275 static struct ng_type ng_bridge_typestruct = { 276 .version = NG_ABI_VERSION, 277 .name = NG_BRIDGE_NODE_TYPE, 278 .constructor = ng_bridge_constructor, 279 .rcvmsg = ng_bridge_rcvmsg, 280 .shutdown = ng_bridge_shutdown, 281 .newhook = ng_bridge_newhook, 282 .rcvdata = ng_bridge_rcvdata, 283 .disconnect = ng_bridge_disconnect, 284 .cmdlist = ng_bridge_cmdlist, 285 }; 286 NETGRAPH_INIT(bridge, &ng_bridge_typestruct); 287 288 /****************************************************************** 289 NETGRAPH NODE METHODS 290 ******************************************************************/ 291 292 /* 293 * Node constructor 294 */ 295 static int 296 ng_bridge_constructor(node_p node) 297 { 298 priv_p priv; 299 300 /* Allocate and initialize private info */ 301 MALLOC(priv, priv_p, 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 MALLOC(priv->tab, struct ng_bridge_bucket *, 308 MIN_BUCKETS * sizeof(*priv->tab), M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO); 309 if (priv->tab == NULL) { 310 FREE(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 MALLOC(priv->links[linkNum], struct ng_bridge_link *, 363 sizeof(*priv->links[linkNum]), M_NETGRAPH_BRIDGE, M_NOWAIT|M_ZERO); 364 if (priv->links[linkNum] == NULL) 365 return (ENOMEM); 366 priv->links[linkNum]->hook = hook; 367 NG_HOOK_SET_PRIVATE(hook, (void *)linkNum); 368 priv->numLinks++; 369 return (0); 370 } 371 372 /* Unknown hook name */ 373 return (EINVAL); 374 } 375 376 /* 377 * Receive a control message 378 */ 379 static int 380 ng_bridge_rcvmsg(node_p node, item_p item, hook_p lasthook) 381 { 382 const priv_p priv = NG_NODE_PRIVATE(node); 383 struct ng_mesg *resp = NULL; 384 int error = 0; 385 struct ng_mesg *msg; 386 387 NGI_GET_MSG(item, msg); 388 switch (msg->header.typecookie) { 389 case NGM_BRIDGE_COOKIE: 390 switch (msg->header.cmd) { 391 case NGM_BRIDGE_GET_CONFIG: 392 { 393 struct ng_bridge_config *conf; 394 395 NG_MKRESPONSE(resp, msg, 396 sizeof(struct ng_bridge_config), M_NOWAIT); 397 if (resp == NULL) { 398 error = ENOMEM; 399 break; 400 } 401 conf = (struct ng_bridge_config *)resp->data; 402 *conf = priv->conf; /* no sanity checking needed */ 403 break; 404 } 405 case NGM_BRIDGE_SET_CONFIG: 406 { 407 struct ng_bridge_config *conf; 408 int i; 409 410 if (msg->header.arglen 411 != sizeof(struct ng_bridge_config)) { 412 error = EINVAL; 413 break; 414 } 415 conf = (struct ng_bridge_config *)msg->data; 416 priv->conf = *conf; 417 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) 418 priv->conf.ipfw[i] = !!priv->conf.ipfw[i]; 419 break; 420 } 421 case NGM_BRIDGE_RESET: 422 { 423 int i; 424 425 /* Flush all entries in the hash table */ 426 ng_bridge_remove_hosts(priv, -1); 427 428 /* Reset all loop detection counters and stats */ 429 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) { 430 if (priv->links[i] == NULL) 431 continue; 432 priv->links[i]->loopCount = 0; 433 bzero(&priv->links[i]->stats, 434 sizeof(priv->links[i]->stats)); 435 } 436 break; 437 } 438 case NGM_BRIDGE_GET_STATS: 439 case NGM_BRIDGE_CLR_STATS: 440 case NGM_BRIDGE_GETCLR_STATS: 441 { 442 struct ng_bridge_link *link; 443 int linkNum; 444 445 /* Get link number */ 446 if (msg->header.arglen != sizeof(u_int32_t)) { 447 error = EINVAL; 448 break; 449 } 450 linkNum = *((u_int32_t *)msg->data); 451 if (linkNum < 0 || linkNum >= NG_BRIDGE_MAX_LINKS) { 452 error = EINVAL; 453 break; 454 } 455 if ((link = priv->links[linkNum]) == NULL) { 456 error = ENOTCONN; 457 break; 458 } 459 460 /* Get/clear stats */ 461 if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) { 462 NG_MKRESPONSE(resp, msg, 463 sizeof(link->stats), M_NOWAIT); 464 if (resp == NULL) { 465 error = ENOMEM; 466 break; 467 } 468 bcopy(&link->stats, 469 resp->data, sizeof(link->stats)); 470 } 471 if (msg->header.cmd != NGM_BRIDGE_GET_STATS) 472 bzero(&link->stats, sizeof(link->stats)); 473 break; 474 } 475 case NGM_BRIDGE_GET_TABLE: 476 { 477 struct ng_bridge_host_ary *ary; 478 struct ng_bridge_hent *hent; 479 int i = 0, bucket; 480 481 NG_MKRESPONSE(resp, msg, sizeof(*ary) 482 + (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT); 483 if (resp == NULL) { 484 error = ENOMEM; 485 break; 486 } 487 ary = (struct ng_bridge_host_ary *)resp->data; 488 ary->numHosts = priv->numHosts; 489 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 490 SLIST_FOREACH(hent, &priv->tab[bucket], next) 491 ary->hosts[i++] = hent->host; 492 } 493 break; 494 } 495 default: 496 error = EINVAL; 497 break; 498 } 499 break; 500 default: 501 error = EINVAL; 502 break; 503 } 504 505 /* Done */ 506 NG_RESPOND_MSG(error, node, item, resp); 507 NG_FREE_MSG(msg); 508 return (error); 509 } 510 511 /* 512 * Receive data on a hook 513 */ 514 static int 515 ng_bridge_rcvdata(hook_p hook, item_p item) 516 { 517 const node_p node = NG_HOOK_NODE(hook); 518 const priv_p priv = NG_NODE_PRIVATE(node); 519 struct ng_bridge_host *host; 520 struct ng_bridge_link *link; 521 struct ether_header *eh; 522 int error = 0, linkNum, linksSeen; 523 int manycast; 524 struct mbuf *m; 525 struct ng_bridge_link *firstLink; 526 527 NGI_GET_M(item, m); 528 /* Get link number */ 529 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook); 530 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 531 ("%s: linkNum=%u", __func__, linkNum)); 532 link = priv->links[linkNum]; 533 KASSERT(link != NULL, ("%s: link%d null", __func__, linkNum)); 534 535 /* Sanity check packet and pull up header */ 536 if (m->m_pkthdr.len < ETHER_HDR_LEN) { 537 link->stats.recvRunts++; 538 NG_FREE_ITEM(item); 539 NG_FREE_M(m); 540 return (EINVAL); 541 } 542 if (m->m_len < ETHER_HDR_LEN && !(m = m_pullup(m, ETHER_HDR_LEN))) { 543 link->stats.memoryFailures++; 544 NG_FREE_ITEM(item); 545 return (ENOBUFS); 546 } 547 eh = mtod(m, struct ether_header *); 548 if ((eh->ether_shost[0] & 1) != 0) { 549 link->stats.recvInvalid++; 550 NG_FREE_ITEM(item); 551 NG_FREE_M(m); 552 return (EINVAL); 553 } 554 555 /* Is link disabled due to a loopback condition? */ 556 if (link->loopCount != 0) { 557 link->stats.loopDrops++; 558 NG_FREE_ITEM(item); 559 NG_FREE_M(m); 560 return (ELOOP); /* XXX is this an appropriate error? */ 561 } 562 563 /* Update stats */ 564 link->stats.recvPackets++; 565 link->stats.recvOctets += m->m_pkthdr.len; 566 if ((manycast = (eh->ether_dhost[0] & 1)) != 0) { 567 if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) { 568 link->stats.recvBroadcasts++; 569 manycast = 2; 570 } else 571 link->stats.recvMulticasts++; 572 } 573 574 /* Look up packet's source Ethernet address in hashtable */ 575 if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) { 576 577 /* Update time since last heard from this host */ 578 host->staleness = 0; 579 580 /* Did host jump to a different link? */ 581 if (host->linkNum != linkNum) { 582 583 /* 584 * If the host's old link was recently established 585 * on the old link and it's already jumped to a new 586 * link, declare a loopback condition. 587 */ 588 if (host->age < priv->conf.minStableAge) { 589 590 /* Log the problem */ 591 if (priv->conf.debugLevel >= 2) { 592 struct ifnet *ifp = m->m_pkthdr.rcvif; 593 char suffix[32]; 594 595 if (ifp != NULL) 596 snprintf(suffix, sizeof(suffix), 597 " (%s)", ifp->if_xname); 598 else 599 *suffix = '\0'; 600 log(LOG_WARNING, "ng_bridge: %s:" 601 " loopback detected on %s%s\n", 602 ng_bridge_nodename(node), 603 NG_HOOK_NAME(hook), suffix); 604 } 605 606 /* Mark link as linka non grata */ 607 link->loopCount = priv->conf.loopTimeout; 608 link->stats.loopDetects++; 609 610 /* Forget all hosts on this link */ 611 ng_bridge_remove_hosts(priv, linkNum); 612 613 /* Drop packet */ 614 link->stats.loopDrops++; 615 NG_FREE_ITEM(item); 616 NG_FREE_M(m); 617 return (ELOOP); /* XXX appropriate? */ 618 } 619 620 /* Move host over to new link */ 621 host->linkNum = linkNum; 622 host->age = 0; 623 } 624 } else { 625 if (!ng_bridge_put(priv, eh->ether_shost, linkNum)) { 626 link->stats.memoryFailures++; 627 NG_FREE_ITEM(item); 628 NG_FREE_M(m); 629 return (ENOMEM); 630 } 631 } 632 633 /* Run packet through ipfw processing, if enabled */ 634 #if 0 635 if (priv->conf.ipfw[linkNum] && V_fw_enable && ip_fw_chk_ptr != NULL) { 636 /* XXX not implemented yet */ 637 } 638 #endif 639 640 /* 641 * If unicast and destination host known, deliver to host's link, 642 * unless it is the same link as the packet came in on. 643 */ 644 if (!manycast) { 645 646 /* Determine packet destination link */ 647 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) { 648 struct ng_bridge_link *const destLink 649 = priv->links[host->linkNum]; 650 651 /* If destination same as incoming link, do nothing */ 652 KASSERT(destLink != NULL, 653 ("%s: link%d null", __func__, host->linkNum)); 654 if (destLink == link) { 655 NG_FREE_ITEM(item); 656 NG_FREE_M(m); 657 return (0); 658 } 659 660 /* Deliver packet out the destination link */ 661 destLink->stats.xmitPackets++; 662 destLink->stats.xmitOctets += m->m_pkthdr.len; 663 NG_FWD_NEW_DATA(error, item, destLink->hook, m); 664 return (error); 665 } 666 667 /* Destination host is not known */ 668 link->stats.recvUnknown++; 669 } 670 671 /* Distribute unknown, multicast, broadcast pkts to all other links */ 672 firstLink = NULL; 673 for (linkNum = linksSeen = 0; linksSeen <= priv->numLinks; linkNum++) { 674 struct ng_bridge_link *destLink; 675 struct mbuf *m2 = NULL; 676 677 /* 678 * If we have checked all the links then now 679 * send the original on its reserved link 680 */ 681 if (linksSeen == priv->numLinks) { 682 /* If we never saw a good link, leave. */ 683 if (firstLink == NULL) { 684 NG_FREE_ITEM(item); 685 NG_FREE_M(m); 686 return (0); 687 } 688 destLink = firstLink; 689 } else { 690 destLink = priv->links[linkNum]; 691 if (destLink != NULL) 692 linksSeen++; 693 /* Skip incoming link and disconnected links */ 694 if (destLink == NULL || destLink == link) { 695 continue; 696 } 697 if (firstLink == NULL) { 698 /* 699 * This is the first usable link we have found. 700 * Reserve it for the originals. 701 * If we never find another we save a copy. 702 */ 703 firstLink = destLink; 704 continue; 705 } 706 707 /* 708 * It's usable link but not the reserved (first) one. 709 * Copy mbuf info for sending. 710 */ 711 m2 = m_dup(m, M_DONTWAIT); /* XXX m_copypacket() */ 712 if (m2 == NULL) { 713 link->stats.memoryFailures++; 714 NG_FREE_ITEM(item); 715 NG_FREE_M(m); 716 return (ENOBUFS); 717 } 718 } 719 720 /* Update stats */ 721 destLink->stats.xmitPackets++; 722 destLink->stats.xmitOctets += m->m_pkthdr.len; 723 switch (manycast) { 724 case 0: /* unicast */ 725 break; 726 case 1: /* multicast */ 727 destLink->stats.xmitMulticasts++; 728 break; 729 case 2: /* broadcast */ 730 destLink->stats.xmitBroadcasts++; 731 break; 732 } 733 734 /* Send packet */ 735 if (destLink == firstLink) { 736 /* 737 * If we've sent all the others, send the original 738 * on the first link we found. 739 */ 740 NG_FWD_NEW_DATA(error, item, destLink->hook, m); 741 break; /* always done last - not really needed. */ 742 } else { 743 NG_SEND_DATA_ONLY(error, destLink->hook, m2); 744 } 745 } 746 return (error); 747 } 748 749 /* 750 * Shutdown node 751 */ 752 static int 753 ng_bridge_shutdown(node_p node) 754 { 755 const priv_p priv = NG_NODE_PRIVATE(node); 756 757 /* 758 * Shut down everything including the timer. Even if the 759 * callout has already been dequeued and is about to be 760 * run, ng_bridge_timeout() won't be fired as the node 761 * is already marked NGF_INVALID, so we're safe to free 762 * the node now. 763 */ 764 KASSERT(priv->numLinks == 0 && priv->numHosts == 0, 765 ("%s: numLinks=%d numHosts=%d", 766 __func__, priv->numLinks, priv->numHosts)); 767 ng_uncallout(&priv->timer, node); 768 NG_NODE_SET_PRIVATE(node, NULL); 769 NG_NODE_UNREF(node); 770 FREE(priv->tab, M_NETGRAPH_BRIDGE); 771 FREE(priv, M_NETGRAPH_BRIDGE); 772 return (0); 773 } 774 775 /* 776 * Hook disconnection. 777 */ 778 static int 779 ng_bridge_disconnect(hook_p hook) 780 { 781 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); 782 int linkNum; 783 784 /* Get link number */ 785 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook); 786 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 787 ("%s: linkNum=%u", __func__, linkNum)); 788 789 /* Remove all hosts associated with this link */ 790 ng_bridge_remove_hosts(priv, linkNum); 791 792 /* Free associated link information */ 793 KASSERT(priv->links[linkNum] != NULL, ("%s: no link", __func__)); 794 FREE(priv->links[linkNum], M_NETGRAPH_BRIDGE); 795 priv->links[linkNum] = NULL; 796 priv->numLinks--; 797 798 /* If no more hooks, go away */ 799 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) 800 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) { 801 ng_rmnode_self(NG_HOOK_NODE(hook)); 802 } 803 return (0); 804 } 805 806 /****************************************************************** 807 HASH TABLE FUNCTIONS 808 ******************************************************************/ 809 810 /* 811 * Hash algorithm 812 */ 813 #define HASH(addr,mask) ( (((const u_int16_t *)(addr))[0] \ 814 ^ ((const u_int16_t *)(addr))[1] \ 815 ^ ((const u_int16_t *)(addr))[2]) & (mask) ) 816 817 /* 818 * Find a host entry in the table. 819 */ 820 static struct ng_bridge_host * 821 ng_bridge_get(priv_p priv, const u_char *addr) 822 { 823 const int bucket = HASH(addr, priv->hashMask); 824 struct ng_bridge_hent *hent; 825 826 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 827 if (ETHER_EQUAL(hent->host.addr, addr)) 828 return (&hent->host); 829 } 830 return (NULL); 831 } 832 833 /* 834 * Add a new host entry to the table. This assumes the host doesn't 835 * already exist in the table. Returns 1 on success, 0 if there 836 * was a memory allocation failure. 837 */ 838 static int 839 ng_bridge_put(priv_p priv, const u_char *addr, int linkNum) 840 { 841 const int bucket = HASH(addr, priv->hashMask); 842 struct ng_bridge_hent *hent; 843 844 #ifdef INVARIANTS 845 /* Assert that entry does not already exist in hashtable */ 846 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 847 KASSERT(!ETHER_EQUAL(hent->host.addr, addr), 848 ("%s: entry %6D exists in table", __func__, addr, ":")); 849 } 850 #endif 851 852 /* Allocate and initialize new hashtable entry */ 853 MALLOC(hent, struct ng_bridge_hent *, 854 sizeof(*hent), M_NETGRAPH_BRIDGE, M_NOWAIT); 855 if (hent == NULL) 856 return (0); 857 bcopy(addr, hent->host.addr, ETHER_ADDR_LEN); 858 hent->host.linkNum = linkNum; 859 hent->host.staleness = 0; 860 hent->host.age = 0; 861 862 /* Add new element to hash bucket */ 863 SLIST_INSERT_HEAD(&priv->tab[bucket], hent, next); 864 priv->numHosts++; 865 866 /* Resize table if necessary */ 867 ng_bridge_rehash(priv); 868 return (1); 869 } 870 871 /* 872 * Resize the hash table. We try to maintain the number of buckets 873 * such that the load factor is in the range 0.25 to 1.0. 874 * 875 * If we can't get the new memory then we silently fail. This is OK 876 * because things will still work and we'll try again soon anyway. 877 */ 878 static void 879 ng_bridge_rehash(priv_p priv) 880 { 881 struct ng_bridge_bucket *newTab; 882 int oldBucket, newBucket; 883 int newNumBuckets; 884 u_int newMask; 885 886 /* Is table too full or too empty? */ 887 if (priv->numHosts > priv->numBuckets 888 && (priv->numBuckets << 1) <= MAX_BUCKETS) 889 newNumBuckets = priv->numBuckets << 1; 890 else if (priv->numHosts < (priv->numBuckets >> 2) 891 && (priv->numBuckets >> 2) >= MIN_BUCKETS) 892 newNumBuckets = priv->numBuckets >> 2; 893 else 894 return; 895 newMask = newNumBuckets - 1; 896 897 /* Allocate and initialize new table */ 898 MALLOC(newTab, struct ng_bridge_bucket *, 899 newNumBuckets * sizeof(*newTab), M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO); 900 if (newTab == NULL) 901 return; 902 903 /* Move all entries from old table to new table */ 904 for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) { 905 struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket]; 906 907 while (!SLIST_EMPTY(oldList)) { 908 struct ng_bridge_hent *const hent 909 = SLIST_FIRST(oldList); 910 911 SLIST_REMOVE_HEAD(oldList, next); 912 newBucket = HASH(hent->host.addr, newMask); 913 SLIST_INSERT_HEAD(&newTab[newBucket], hent, next); 914 } 915 } 916 917 /* Replace old table with new one */ 918 if (priv->conf.debugLevel >= 3) { 919 log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n", 920 ng_bridge_nodename(priv->node), 921 priv->numBuckets, newNumBuckets); 922 } 923 FREE(priv->tab, M_NETGRAPH_BRIDGE); 924 priv->numBuckets = newNumBuckets; 925 priv->hashMask = newMask; 926 priv->tab = newTab; 927 return; 928 } 929 930 /****************************************************************** 931 MISC FUNCTIONS 932 ******************************************************************/ 933 934 /* 935 * Remove all hosts associated with a specific link from the hashtable. 936 * If linkNum == -1, then remove all hosts in the table. 937 */ 938 static void 939 ng_bridge_remove_hosts(priv_p priv, int linkNum) 940 { 941 int bucket; 942 943 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 944 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 945 946 while (*hptr != NULL) { 947 struct ng_bridge_hent *const hent = *hptr; 948 949 if (linkNum == -1 || hent->host.linkNum == linkNum) { 950 *hptr = SLIST_NEXT(hent, next); 951 FREE(hent, M_NETGRAPH_BRIDGE); 952 priv->numHosts--; 953 } else 954 hptr = &SLIST_NEXT(hent, next); 955 } 956 } 957 } 958 959 /* 960 * Handle our once-per-second timeout event. We do two things: 961 * we decrement link->loopCount for those links being muted due to 962 * a detected loopback condition, and we remove any hosts from 963 * the hashtable whom we haven't heard from in a long while. 964 */ 965 static void 966 ng_bridge_timeout(node_p node, hook_p hook, void *arg1, int arg2) 967 { 968 const priv_p priv = NG_NODE_PRIVATE(node); 969 int bucket; 970 int counter = 0; 971 int linkNum; 972 973 /* Update host time counters and remove stale entries */ 974 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 975 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 976 977 while (*hptr != NULL) { 978 struct ng_bridge_hent *const hent = *hptr; 979 980 /* Make sure host's link really exists */ 981 KASSERT(priv->links[hent->host.linkNum] != NULL, 982 ("%s: host %6D on nonexistent link %d\n", 983 __func__, hent->host.addr, ":", 984 hent->host.linkNum)); 985 986 /* Remove hosts we haven't heard from in a while */ 987 if (++hent->host.staleness >= priv->conf.maxStaleness) { 988 *hptr = SLIST_NEXT(hent, next); 989 FREE(hent, M_NETGRAPH_BRIDGE); 990 priv->numHosts--; 991 } else { 992 if (hent->host.age < 0xffff) 993 hent->host.age++; 994 hptr = &SLIST_NEXT(hent, next); 995 counter++; 996 } 997 } 998 } 999 KASSERT(priv->numHosts == counter, 1000 ("%s: hosts: %d != %d", __func__, priv->numHosts, counter)); 1001 1002 /* Decrease table size if necessary */ 1003 ng_bridge_rehash(priv); 1004 1005 /* Decrease loop counter on muted looped back links */ 1006 for (counter = linkNum = 0; linkNum < NG_BRIDGE_MAX_LINKS; linkNum++) { 1007 struct ng_bridge_link *const link = priv->links[linkNum]; 1008 1009 if (link != NULL) { 1010 if (link->loopCount != 0) { 1011 link->loopCount--; 1012 if (link->loopCount == 0 1013 && priv->conf.debugLevel >= 2) { 1014 log(LOG_INFO, "ng_bridge: %s:" 1015 " restoring looped back link%d\n", 1016 ng_bridge_nodename(node), linkNum); 1017 } 1018 } 1019 counter++; 1020 } 1021 } 1022 KASSERT(priv->numLinks == counter, 1023 ("%s: links: %d != %d", __func__, priv->numLinks, counter)); 1024 1025 /* Register a new timeout, keeping the existing node reference */ 1026 ng_callout(&priv->timer, node, NULL, hz, ng_bridge_timeout, NULL, 0); 1027 } 1028 1029 /* 1030 * Return node's "name", even if it doesn't have one. 1031 */ 1032 static const char * 1033 ng_bridge_nodename(node_p node) 1034 { 1035 static char name[NG_NODESIZ]; 1036 1037 if (NG_NODE_NAME(node) != NULL) 1038 snprintf(name, sizeof(name), "%s", NG_NODE_NAME(node)); 1039 else 1040 snprintf(name, sizeof(name), "[%x]", ng_node2ID(node)); 1041 return name; 1042 } 1043 1044