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sys/netgraph/ng_bridge.c
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1 2 /* 3 * ng_bridge.c 4 * 5 * Copyright (c) 2000 Whistle Communications, Inc. 6 * All rights reserved. 7 * 8 * Subject to the following obligations and disclaimer of warranty, use and 9 * redistribution of this software, in source or object code forms, with or 10 * without modifications are expressly permitted by Whistle Communications; 11 * provided, however, that: 12 * 1. Any and all reproductions of the source or object code must include the 13 * copyright notice above and the following disclaimer of warranties; and 14 * 2. No rights are granted, in any manner or form, to use Whistle 15 * Communications, Inc. trademarks, including the mark "WHISTLE 16 * COMMUNICATIONS" on advertising, endorsements, or otherwise except as 17 * such appears in the above copyright notice or in the software. 18 * 19 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND 20 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO 21 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE, 22 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF 23 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. 24 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY 25 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS 26 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE. 27 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES 28 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING 29 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 30 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR 31 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY 32 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 33 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 34 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY 35 * OF SUCH DAMAGE. 36 * 37 * Author: Archie Cobbs <archie@freebsd.org> 38 * 39 * $FreeBSD: releng/5.3/sys/netgraph/ng_bridge.c 136588 2004-10-16 08:43:07Z cvs2svn $ 40 */ 41 42 /* 43 * ng_bridge(4) netgraph node type 44 * 45 * The node performs standard intelligent Ethernet bridging over 46 * each of its connected hooks, or links. A simple loop detection 47 * algorithm is included which disables a link for priv->conf.loopTimeout 48 * seconds when a host is seen to have jumped from one link to 49 * another within priv->conf.minStableAge seconds. 50 * 51 * We keep a hashtable that maps Ethernet addresses to host info, 52 * which is contained in struct ng_bridge_host's. These structures 53 * tell us on which link the host may be found. A host's entry will 54 * expire after priv->conf.maxStaleness seconds. 55 * 56 * This node is optimzed for stable networks, where machines jump 57 * from one port to the other only rarely. 58 */ 59 60 #include <sys/param.h> 61 #include <sys/systm.h> 62 #include <sys/kernel.h> 63 #include <sys/malloc.h> 64 #include <sys/mbuf.h> 65 #include <sys/errno.h> 66 #include <sys/syslog.h> 67 #include <sys/socket.h> 68 #include <sys/ctype.h> 69 70 #include <net/if.h> 71 #include <net/ethernet.h> 72 73 #include <netinet/in.h> 74 #include <netinet/ip_fw.h> 75 76 #include <netgraph/ng_message.h> 77 #include <netgraph/netgraph.h> 78 #include <netgraph/ng_parse.h> 79 #include <netgraph/ng_bridge.h> 80 81 #ifdef NG_SEPARATE_MALLOC 82 MALLOC_DEFINE(M_NETGRAPH_BRIDGE, "netgraph_bridge", "netgraph bridge node "); 83 #else 84 #define M_NETGRAPH_BRIDGE M_NETGRAPH 85 #endif 86 87 /* Per-link private data */ 88 struct ng_bridge_link { 89 hook_p hook; /* netgraph hook */ 90 u_int16_t loopCount; /* loop ignore timer */ 91 struct ng_bridge_link_stats stats; /* link stats */ 92 }; 93 94 /* Per-node private data */ 95 struct ng_bridge_private { 96 struct ng_bridge_bucket *tab; /* hash table bucket array */ 97 struct ng_bridge_link *links[NG_BRIDGE_MAX_LINKS]; 98 struct ng_bridge_config conf; /* node configuration */ 99 node_p node; /* netgraph node */ 100 u_int numHosts; /* num entries in table */ 101 u_int numBuckets; /* num buckets in table */ 102 u_int hashMask; /* numBuckets - 1 */ 103 int numLinks; /* num connected links */ 104 struct callout timer; /* one second periodic timer */ 105 }; 106 typedef struct ng_bridge_private *priv_p; 107 108 /* Information about a host, stored in a hash table entry */ 109 struct ng_bridge_hent { 110 struct ng_bridge_host host; /* actual host info */ 111 SLIST_ENTRY(ng_bridge_hent) next; /* next entry in bucket */ 112 }; 113 114 /* Hash table bucket declaration */ 115 SLIST_HEAD(ng_bridge_bucket, ng_bridge_hent); 116 117 /* Netgraph node methods */ 118 static ng_constructor_t ng_bridge_constructor; 119 static ng_rcvmsg_t ng_bridge_rcvmsg; 120 static ng_shutdown_t ng_bridge_shutdown; 121 static ng_newhook_t ng_bridge_newhook; 122 static ng_rcvdata_t ng_bridge_rcvdata; 123 static ng_disconnect_t ng_bridge_disconnect; 124 125 /* Other internal functions */ 126 static struct ng_bridge_host *ng_bridge_get(priv_p priv, const u_char *addr); 127 static int ng_bridge_put(priv_p priv, const u_char *addr, int linkNum); 128 static void ng_bridge_rehash(priv_p priv); 129 static void ng_bridge_remove_hosts(priv_p priv, int linkNum); 130 static void ng_bridge_timeout(void *arg); 131 static const char *ng_bridge_nodename(node_p node); 132 133 /* Ethernet broadcast */ 134 static const u_char ng_bridge_bcast_addr[ETHER_ADDR_LEN] = 135 { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; 136 137 /* Store each hook's link number in the private field */ 138 #define LINK_NUM(hook) (*(u_int16_t *)(&(hook)->private)) 139 140 /* Compare Ethernet addresses using 32 and 16 bit words instead of bytewise */ 141 #define ETHER_EQUAL(a,b) (((const u_int32_t *)(a))[0] \ 142 == ((const u_int32_t *)(b))[0] \ 143 && ((const u_int16_t *)(a))[2] \ 144 == ((const u_int16_t *)(b))[2]) 145 146 /* Minimum and maximum number of hash buckets. Must be a power of two. */ 147 #define MIN_BUCKETS (1 << 5) /* 32 */ 148 #define MAX_BUCKETS (1 << 14) /* 16384 */ 149 150 /* Configuration default values */ 151 #define DEFAULT_LOOP_TIMEOUT 60 152 #define DEFAULT_MAX_STALENESS (15 * 60) /* same as ARP timeout */ 153 #define DEFAULT_MIN_STABLE_AGE 1 154 155 /****************************************************************** 156 NETGRAPH PARSE TYPES 157 ******************************************************************/ 158 159 /* 160 * How to determine the length of the table returned by NGM_BRIDGE_GET_TABLE 161 */ 162 static int 163 ng_bridge_getTableLength(const struct ng_parse_type *type, 164 const u_char *start, const u_char *buf) 165 { 166 const struct ng_bridge_host_ary *const hary 167 = (const struct ng_bridge_host_ary *)(buf - sizeof(u_int32_t)); 168 169 return hary->numHosts; 170 } 171 172 /* Parse type for struct ng_bridge_host_ary */ 173 static const struct ng_parse_struct_field ng_bridge_host_type_fields[] 174 = NG_BRIDGE_HOST_TYPE_INFO(&ng_parse_enaddr_type); 175 static const struct ng_parse_type ng_bridge_host_type = { 176 &ng_parse_struct_type, 177 &ng_bridge_host_type_fields 178 }; 179 static const struct ng_parse_array_info ng_bridge_hary_type_info = { 180 &ng_bridge_host_type, 181 ng_bridge_getTableLength 182 }; 183 static const struct ng_parse_type ng_bridge_hary_type = { 184 &ng_parse_array_type, 185 &ng_bridge_hary_type_info 186 }; 187 static const struct ng_parse_struct_field ng_bridge_host_ary_type_fields[] 188 = NG_BRIDGE_HOST_ARY_TYPE_INFO(&ng_bridge_hary_type); 189 static const struct ng_parse_type ng_bridge_host_ary_type = { 190 &ng_parse_struct_type, 191 &ng_bridge_host_ary_type_fields 192 }; 193 194 /* Parse type for struct ng_bridge_config */ 195 static const struct ng_parse_fixedarray_info ng_bridge_ipfwary_type_info = { 196 &ng_parse_uint8_type, 197 NG_BRIDGE_MAX_LINKS 198 }; 199 static const struct ng_parse_type ng_bridge_ipfwary_type = { 200 &ng_parse_fixedarray_type, 201 &ng_bridge_ipfwary_type_info 202 }; 203 static const struct ng_parse_struct_field ng_bridge_config_type_fields[] 204 = NG_BRIDGE_CONFIG_TYPE_INFO(&ng_bridge_ipfwary_type); 205 static const struct ng_parse_type ng_bridge_config_type = { 206 &ng_parse_struct_type, 207 &ng_bridge_config_type_fields 208 }; 209 210 /* Parse type for struct ng_bridge_link_stat */ 211 static const struct ng_parse_struct_field ng_bridge_stats_type_fields[] 212 = NG_BRIDGE_STATS_TYPE_INFO; 213 static const struct ng_parse_type ng_bridge_stats_type = { 214 &ng_parse_struct_type, 215 &ng_bridge_stats_type_fields 216 }; 217 218 /* List of commands and how to convert arguments to/from ASCII */ 219 static const struct ng_cmdlist ng_bridge_cmdlist[] = { 220 { 221 NGM_BRIDGE_COOKIE, 222 NGM_BRIDGE_SET_CONFIG, 223 "setconfig", 224 &ng_bridge_config_type, 225 NULL 226 }, 227 { 228 NGM_BRIDGE_COOKIE, 229 NGM_BRIDGE_GET_CONFIG, 230 "getconfig", 231 NULL, 232 &ng_bridge_config_type 233 }, 234 { 235 NGM_BRIDGE_COOKIE, 236 NGM_BRIDGE_RESET, 237 "reset", 238 NULL, 239 NULL 240 }, 241 { 242 NGM_BRIDGE_COOKIE, 243 NGM_BRIDGE_GET_STATS, 244 "getstats", 245 &ng_parse_uint32_type, 246 &ng_bridge_stats_type 247 }, 248 { 249 NGM_BRIDGE_COOKIE, 250 NGM_BRIDGE_CLR_STATS, 251 "clrstats", 252 &ng_parse_uint32_type, 253 NULL 254 }, 255 { 256 NGM_BRIDGE_COOKIE, 257 NGM_BRIDGE_GETCLR_STATS, 258 "getclrstats", 259 &ng_parse_uint32_type, 260 &ng_bridge_stats_type 261 }, 262 { 263 NGM_BRIDGE_COOKIE, 264 NGM_BRIDGE_GET_TABLE, 265 "gettable", 266 NULL, 267 &ng_bridge_host_ary_type 268 }, 269 { 0 } 270 }; 271 272 /* Node type descriptor */ 273 static struct ng_type ng_bridge_typestruct = { 274 .version = NG_ABI_VERSION, 275 .name = NG_BRIDGE_NODE_TYPE, 276 .constructor = ng_bridge_constructor, 277 .rcvmsg = ng_bridge_rcvmsg, 278 .shutdown = ng_bridge_shutdown, 279 .newhook = ng_bridge_newhook, 280 .rcvdata = ng_bridge_rcvdata, 281 .disconnect = ng_bridge_disconnect, 282 .cmdlist = ng_bridge_cmdlist, 283 }; 284 NETGRAPH_INIT(bridge, &ng_bridge_typestruct); 285 286 /****************************************************************** 287 NETGRAPH NODE METHODS 288 ******************************************************************/ 289 290 /* 291 * Node constructor 292 */ 293 static int 294 ng_bridge_constructor(node_p node) 295 { 296 priv_p priv; 297 298 /* Allocate and initialize private info */ 299 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO); 300 if (priv == NULL) 301 return (ENOMEM); 302 callout_init(&priv->timer, 0); 303 304 /* Allocate and initialize hash table, etc. */ 305 MALLOC(priv->tab, struct ng_bridge_bucket *, 306 MIN_BUCKETS * sizeof(*priv->tab), M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO); 307 if (priv->tab == NULL) { 308 FREE(priv, M_NETGRAPH_BRIDGE); 309 return (ENOMEM); 310 } 311 priv->numBuckets = MIN_BUCKETS; 312 priv->hashMask = MIN_BUCKETS - 1; 313 priv->conf.debugLevel = 1; 314 priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT; 315 priv->conf.maxStaleness = DEFAULT_MAX_STALENESS; 316 priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE; 317 318 /* 319 * This node has all kinds of stuff that could be screwed by SMP. 320 * Until it gets it's own internal protection, we go through in 321 * single file. This could hurt a machine bridging beteen two 322 * GB ethernets so it should be fixed. 323 * When it's fixed the process SHOULD NOT SLEEP, spinlocks please! 324 * (and atomic ops ) 325 */ 326 NG_NODE_FORCE_WRITER(node); 327 NG_NODE_SET_PRIVATE(node, priv); 328 priv->node = node; 329 330 /* Start timer; timer is always running while node is alive */ 331 callout_reset(&priv->timer, hz, ng_bridge_timeout, priv->node); 332 333 /* Done */ 334 return (0); 335 } 336 337 /* 338 * Method for attaching a new hook 339 */ 340 static int 341 ng_bridge_newhook(node_p node, hook_p hook, const char *name) 342 { 343 const priv_p priv = NG_NODE_PRIVATE(node); 344 345 /* Check for a link hook */ 346 if (strncmp(name, NG_BRIDGE_HOOK_LINK_PREFIX, 347 strlen(NG_BRIDGE_HOOK_LINK_PREFIX)) == 0) { 348 const char *cp; 349 char *eptr; 350 u_long linkNum; 351 352 cp = name + strlen(NG_BRIDGE_HOOK_LINK_PREFIX); 353 if (!isdigit(*cp) || (cp[0] == '' && cp[1] != '\0')) 354 return (EINVAL); 355 linkNum = strtoul(cp, &eptr, 10); 356 if (*eptr != '\0' || linkNum >= NG_BRIDGE_MAX_LINKS) 357 return (EINVAL); 358 if (priv->links[linkNum] != NULL) 359 return (EISCONN); 360 MALLOC(priv->links[linkNum], struct ng_bridge_link *, 361 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 */ 377 static int 378 ng_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 */ 512 static int 513 ng_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] && 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 */ 750 static int 751 ng_bridge_shutdown(node_p node) 752 { 753 const priv_p priv = NG_NODE_PRIVATE(node); 754 755 /* 756 * Shut down everything except the timer. There's no way to 757 * avoid another possible timeout event (it may have already 758 * been dequeued), so we can't free the node yet. 759 */ 760 KASSERT(priv->numLinks == 0 && priv->numHosts == 0, 761 ("%s: numLinks=%d numHosts=%d", 762 __func__, priv->numLinks, priv->numHosts)); 763 FREE(priv->tab, M_NETGRAPH_BRIDGE); 764 765 /* NGF_INVALID flag is now set so node will be freed at next timeout */ 766 return (0); 767 } 768 769 /* 770 * Hook disconnection. 771 */ 772 static int 773 ng_bridge_disconnect(hook_p hook) 774 { 775 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); 776 int linkNum; 777 778 /* Get link number */ 779 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook); 780 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 781 ("%s: linkNum=%u", __func__, linkNum)); 782 783 /* Remove all hosts associated with this link */ 784 ng_bridge_remove_hosts(priv, linkNum); 785 786 /* Free associated link information */ 787 KASSERT(priv->links[linkNum] != NULL, ("%s: no link", __func__)); 788 FREE(priv->links[linkNum], M_NETGRAPH_BRIDGE); 789 priv->links[linkNum] = NULL; 790 priv->numLinks--; 791 792 /* If no more hooks, go away */ 793 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) 794 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) { 795 ng_rmnode_self(NG_HOOK_NODE(hook)); 796 } 797 return (0); 798 } 799 800 /****************************************************************** 801 HASH TABLE FUNCTIONS 802 ******************************************************************/ 803 804 /* 805 * Hash algorithm 806 */ 807 #define HASH(addr,mask) ( (((const u_int16_t *)(addr))[0] \ 808 ^ ((const u_int16_t *)(addr))[1] \ 809 ^ ((const u_int16_t *)(addr))[2]) & (mask) ) 810 811 /* 812 * Find a host entry in the table. 813 */ 814 static struct ng_bridge_host * 815 ng_bridge_get(priv_p priv, const u_char *addr) 816 { 817 const int bucket = HASH(addr, priv->hashMask); 818 struct ng_bridge_hent *hent; 819 820 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 821 if (ETHER_EQUAL(hent->host.addr, addr)) 822 return (&hent->host); 823 } 824 return (NULL); 825 } 826 827 /* 828 * Add a new host entry to the table. This assumes the host doesn't 829 * already exist in the table. Returns 1 on success, 0 if there 830 * was a memory allocation failure. 831 */ 832 static int 833 ng_bridge_put(priv_p priv, const u_char *addr, int linkNum) 834 { 835 const int bucket = HASH(addr, priv->hashMask); 836 struct ng_bridge_hent *hent; 837 838 #ifdef INVARIANTS 839 /* Assert that entry does not already exist in hashtable */ 840 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 841 KASSERT(!ETHER_EQUAL(hent->host.addr, addr), 842 ("%s: entry %6D exists in table", __func__, addr, ":")); 843 } 844 #endif 845 846 /* Allocate and initialize new hashtable entry */ 847 MALLOC(hent, struct ng_bridge_hent *, 848 sizeof(*hent), M_NETGRAPH_BRIDGE, M_NOWAIT); 849 if (hent == NULL) 850 return (0); 851 bcopy(addr, hent->host.addr, ETHER_ADDR_LEN); 852 hent->host.linkNum = linkNum; 853 hent->host.staleness = 0; 854 hent->host.age = 0; 855 856 /* Add new element to hash bucket */ 857 SLIST_INSERT_HEAD(&priv->tab[bucket], hent, next); 858 priv->numHosts++; 859 860 /* Resize table if necessary */ 861 ng_bridge_rehash(priv); 862 return (1); 863 } 864 865 /* 866 * Resize the hash table. We try to maintain the number of buckets 867 * such that the load factor is in the range 0.25 to 1.0. 868 * 869 * If we can't get the new memory then we silently fail. This is OK 870 * because things will still work and we'll try again soon anyway. 871 */ 872 static void 873 ng_bridge_rehash(priv_p priv) 874 { 875 struct ng_bridge_bucket *newTab; 876 int oldBucket, newBucket; 877 int newNumBuckets; 878 u_int newMask; 879 880 /* Is table too full or too empty? */ 881 if (priv->numHosts > priv->numBuckets 882 && (priv->numBuckets << 1) <= MAX_BUCKETS) 883 newNumBuckets = priv->numBuckets << 1; 884 else if (priv->numHosts < (priv->numBuckets >> 2) 885 && (priv->numBuckets >> 2) >= MIN_BUCKETS) 886 newNumBuckets = priv->numBuckets >> 2; 887 else 888 return; 889 newMask = newNumBuckets - 1; 890 891 /* Allocate and initialize new table */ 892 MALLOC(newTab, struct ng_bridge_bucket *, 893 newNumBuckets * sizeof(*newTab), M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO); 894 if (newTab == NULL) 895 return; 896 897 /* Move all entries from old table to new table */ 898 for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) { 899 struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket]; 900 901 while (!SLIST_EMPTY(oldList)) { 902 struct ng_bridge_hent *const hent 903 = SLIST_FIRST(oldList); 904 905 SLIST_REMOVE_HEAD(oldList, next); 906 newBucket = HASH(hent->host.addr, newMask); 907 SLIST_INSERT_HEAD(&newTab[newBucket], hent, next); 908 } 909 } 910 911 /* Replace old table with new one */ 912 if (priv->conf.debugLevel >= 3) { 913 log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n", 914 ng_bridge_nodename(priv->node), 915 priv->numBuckets, newNumBuckets); 916 } 917 FREE(priv->tab, M_NETGRAPH_BRIDGE); 918 priv->numBuckets = newNumBuckets; 919 priv->hashMask = newMask; 920 priv->tab = newTab; 921 return; 922 } 923 924 /****************************************************************** 925 MISC FUNCTIONS 926 ******************************************************************/ 927 928 /* 929 * Remove all hosts associated with a specific link from the hashtable. 930 * If linkNum == -1, then remove all hosts in the table. 931 */ 932 static void 933 ng_bridge_remove_hosts(priv_p priv, int linkNum) 934 { 935 int bucket; 936 937 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 938 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 939 940 while (*hptr != NULL) { 941 struct ng_bridge_hent *const hent = *hptr; 942 943 if (linkNum == -1 || hent->host.linkNum == linkNum) { 944 *hptr = SLIST_NEXT(hent, next); 945 FREE(hent, M_NETGRAPH_BRIDGE); 946 priv->numHosts--; 947 } else 948 hptr = &SLIST_NEXT(hent, next); 949 } 950 } 951 } 952 953 /* 954 * Handle our once-per-second timeout event. We do two things: 955 * we decrement link->loopCount for those links being muted due to 956 * a detected loopback condition, and we remove any hosts from 957 * the hashtable whom we haven't heard from in a long while. 958 * 959 * If the node has the NGF_INVALID flag set, our job is to kill it. 960 */ 961 static void 962 ng_bridge_timeout(void *arg) 963 { 964 const node_p node = arg; 965 const priv_p priv = NG_NODE_PRIVATE(node); 966 int s, bucket; 967 int counter = 0; 968 int linkNum; 969 970 /* If node was shut down, this is the final lingering timeout */ 971 s = splnet(); 972 if (NG_NODE_NOT_VALID(node)) { 973 FREE(priv, M_NETGRAPH_BRIDGE); 974 NG_NODE_SET_PRIVATE(node, NULL); 975 NG_NODE_UNREF(node); 976 splx(s); 977 return; 978 } 979 980 /* Register a new timeout, keeping the existing node reference */ 981 callout_reset(&priv->timer, hz, ng_bridge_timeout, node); 982 983 /* Update host time counters and remove stale entries */ 984 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 985 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 986 987 while (*hptr != NULL) { 988 struct ng_bridge_hent *const hent = *hptr; 989 990 /* Make sure host's link really exists */ 991 KASSERT(priv->links[hent->host.linkNum] != NULL, 992 ("%s: host %6D on nonexistent link %d\n", 993 __func__, hent->host.addr, ":", 994 hent->host.linkNum)); 995 996 /* Remove hosts we haven't heard from in a while */ 997 if (++hent->host.staleness >= priv->conf.maxStaleness) { 998 *hptr = SLIST_NEXT(hent, next); 999 FREE(hent, M_NETGRAPH_BRIDGE); 1000 priv->numHosts--; 1001 } else { 1002 if (hent->host.age < 0xffff) 1003 hent->host.age++; 1004 hptr = &SLIST_NEXT(hent, next); 1005 counter++; 1006 } 1007 } 1008 } 1009 KASSERT(priv->numHosts == counter, 1010 ("%s: hosts: %d != %d", __func__, priv->numHosts, counter)); 1011 1012 /* Decrease table size if necessary */ 1013 ng_bridge_rehash(priv); 1014 1015 /* Decrease loop counter on muted looped back links */ 1016 for (counter = linkNum = 0; linkNum < NG_BRIDGE_MAX_LINKS; linkNum++) { 1017 struct ng_bridge_link *const link = priv->links[linkNum]; 1018 1019 if (link != NULL) { 1020 if (link->loopCount != 0) { 1021 link->loopCount--; 1022 if (link->loopCount == 0 1023 && priv->conf.debugLevel >= 2) { 1024 log(LOG_INFO, "ng_bridge: %s:" 1025 " restoring looped back link%d\n", 1026 ng_bridge_nodename(node), linkNum); 1027 } 1028 } 1029 counter++; 1030 } 1031 } 1032 KASSERT(priv->numLinks == counter, 1033 ("%s: links: %d != %d", __func__, priv->numLinks, counter)); 1034 1035 /* Done */ 1036 splx(s); 1037 } 1038 1039 /* 1040 * Return node's "name", even if it doesn't have one. 1041 */ 1042 static const char * 1043 ng_bridge_nodename(node_p node) 1044 { 1045 static char name[NG_NODESIZ]; 1046 1047 if (NG_NODE_NAME(node) != NULL) 1048 snprintf(name, sizeof(name), "%s", NG_NODE_NAME(node)); 1049 else 1050 snprintf(name, sizeof(name), "[%x]", ng_node2ID(node)); 1051 return name; 1052 } 1053
Cache object: 29a3249cf511d31c593e09827d4e2e4f
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