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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/5.2/sys/netgraph/ng_bridge.c 121816 2003-10-31 18:32:15Z brooks $ 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 #include <netgraph/ng_ether.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(void *arg); 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_ether_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 NG_ABI_VERSION, 276 NG_BRIDGE_NODE_TYPE, 277 NULL, 278 ng_bridge_constructor, 279 ng_bridge_rcvmsg, 280 ng_bridge_shutdown, 281 ng_bridge_newhook, 282 NULL, 283 NULL, 284 ng_bridge_rcvdata, 285 ng_bridge_disconnect, 286 ng_bridge_cmdlist, 287 }; 288 NETGRAPH_INIT(bridge, &ng_bridge_typestruct); 289 290 /* Depend on ng_ether so we can use the Ethernet parse type */ 291 MODULE_DEPEND(ng_bridge, ng_ether, 1, 1, 1); 292 293 /****************************************************************** 294 NETGRAPH NODE METHODS 295 ******************************************************************/ 296 297 /* 298 * Node constructor 299 */ 300 static int 301 ng_bridge_constructor(node_p node) 302 { 303 priv_p priv; 304 305 /* Allocate and initialize private info */ 306 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO); 307 if (priv == NULL) 308 return (ENOMEM); 309 callout_init(&priv->timer, 0); 310 311 /* Allocate and initialize hash table, etc. */ 312 MALLOC(priv->tab, struct ng_bridge_bucket *, 313 MIN_BUCKETS * sizeof(*priv->tab), M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO); 314 if (priv->tab == NULL) { 315 FREE(priv, M_NETGRAPH_BRIDGE); 316 return (ENOMEM); 317 } 318 priv->numBuckets = MIN_BUCKETS; 319 priv->hashMask = MIN_BUCKETS - 1; 320 priv->conf.debugLevel = 1; 321 priv->conf.loopTimeout = DEFAULT_LOOP_TIMEOUT; 322 priv->conf.maxStaleness = DEFAULT_MAX_STALENESS; 323 priv->conf.minStableAge = DEFAULT_MIN_STABLE_AGE; 324 325 /* 326 * This node has all kinds of stuff that could be screwed by SMP. 327 * Until it gets it's own internal protection, we go through in 328 * single file. This could hurt a machine bridging beteen two 329 * GB ethernets so it should be fixed. 330 * When it's fixed the process SHOULD NOT SLEEP, spinlocks please! 331 * (and atomic ops ) 332 */ 333 NG_NODE_FORCE_WRITER(node); 334 NG_NODE_SET_PRIVATE(node, priv); 335 priv->node = node; 336 337 /* Start timer; timer is always running while node is alive */ 338 callout_reset(&priv->timer, hz, ng_bridge_timeout, priv->node); 339 340 /* Done */ 341 return (0); 342 } 343 344 /* 345 * Method for attaching a new hook 346 */ 347 static int 348 ng_bridge_newhook(node_p node, hook_p hook, const char *name) 349 { 350 const priv_p priv = NG_NODE_PRIVATE(node); 351 352 /* Check for a link hook */ 353 if (strncmp(name, NG_BRIDGE_HOOK_LINK_PREFIX, 354 strlen(NG_BRIDGE_HOOK_LINK_PREFIX)) == 0) { 355 const char *cp; 356 char *eptr; 357 u_long linkNum; 358 359 cp = name + strlen(NG_BRIDGE_HOOK_LINK_PREFIX); 360 if (!isdigit(*cp) || (cp[0] == '' && cp[1] != '\0')) 361 return (EINVAL); 362 linkNum = strtoul(cp, &eptr, 10); 363 if (*eptr != '\0' || linkNum >= NG_BRIDGE_MAX_LINKS) 364 return (EINVAL); 365 if (priv->links[linkNum] != NULL) 366 return (EISCONN); 367 MALLOC(priv->links[linkNum], struct ng_bridge_link *, 368 sizeof(*priv->links[linkNum]), M_NETGRAPH_BRIDGE, M_NOWAIT|M_ZERO); 369 if (priv->links[linkNum] == NULL) 370 return (ENOMEM); 371 priv->links[linkNum]->hook = hook; 372 NG_HOOK_SET_PRIVATE(hook, (void *)linkNum); 373 priv->numLinks++; 374 return (0); 375 } 376 377 /* Unknown hook name */ 378 return (EINVAL); 379 } 380 381 /* 382 * Receive a control message 383 */ 384 static int 385 ng_bridge_rcvmsg(node_p node, item_p item, hook_p lasthook) 386 { 387 const priv_p priv = NG_NODE_PRIVATE(node); 388 struct ng_mesg *resp = NULL; 389 int error = 0; 390 struct ng_mesg *msg; 391 392 NGI_GET_MSG(item, msg); 393 switch (msg->header.typecookie) { 394 case NGM_BRIDGE_COOKIE: 395 switch (msg->header.cmd) { 396 case NGM_BRIDGE_GET_CONFIG: 397 { 398 struct ng_bridge_config *conf; 399 400 NG_MKRESPONSE(resp, msg, 401 sizeof(struct ng_bridge_config), M_NOWAIT); 402 if (resp == NULL) { 403 error = ENOMEM; 404 break; 405 } 406 conf = (struct ng_bridge_config *)resp->data; 407 *conf = priv->conf; /* no sanity checking needed */ 408 break; 409 } 410 case NGM_BRIDGE_SET_CONFIG: 411 { 412 struct ng_bridge_config *conf; 413 int i; 414 415 if (msg->header.arglen 416 != sizeof(struct ng_bridge_config)) { 417 error = EINVAL; 418 break; 419 } 420 conf = (struct ng_bridge_config *)msg->data; 421 priv->conf = *conf; 422 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) 423 priv->conf.ipfw[i] = !!priv->conf.ipfw[i]; 424 break; 425 } 426 case NGM_BRIDGE_RESET: 427 { 428 int i; 429 430 /* Flush all entries in the hash table */ 431 ng_bridge_remove_hosts(priv, -1); 432 433 /* Reset all loop detection counters and stats */ 434 for (i = 0; i < NG_BRIDGE_MAX_LINKS; i++) { 435 if (priv->links[i] == NULL) 436 continue; 437 priv->links[i]->loopCount = 0; 438 bzero(&priv->links[i]->stats, 439 sizeof(priv->links[i]->stats)); 440 } 441 break; 442 } 443 case NGM_BRIDGE_GET_STATS: 444 case NGM_BRIDGE_CLR_STATS: 445 case NGM_BRIDGE_GETCLR_STATS: 446 { 447 struct ng_bridge_link *link; 448 int linkNum; 449 450 /* Get link number */ 451 if (msg->header.arglen != sizeof(u_int32_t)) { 452 error = EINVAL; 453 break; 454 } 455 linkNum = *((u_int32_t *)msg->data); 456 if (linkNum < 0 || linkNum >= NG_BRIDGE_MAX_LINKS) { 457 error = EINVAL; 458 break; 459 } 460 if ((link = priv->links[linkNum]) == NULL) { 461 error = ENOTCONN; 462 break; 463 } 464 465 /* Get/clear stats */ 466 if (msg->header.cmd != NGM_BRIDGE_CLR_STATS) { 467 NG_MKRESPONSE(resp, msg, 468 sizeof(link->stats), M_NOWAIT); 469 if (resp == NULL) { 470 error = ENOMEM; 471 break; 472 } 473 bcopy(&link->stats, 474 resp->data, sizeof(link->stats)); 475 } 476 if (msg->header.cmd != NGM_BRIDGE_GET_STATS) 477 bzero(&link->stats, sizeof(link->stats)); 478 break; 479 } 480 case NGM_BRIDGE_GET_TABLE: 481 { 482 struct ng_bridge_host_ary *ary; 483 struct ng_bridge_hent *hent; 484 int i = 0, bucket; 485 486 NG_MKRESPONSE(resp, msg, sizeof(*ary) 487 + (priv->numHosts * sizeof(*ary->hosts)), M_NOWAIT); 488 if (resp == NULL) { 489 error = ENOMEM; 490 break; 491 } 492 ary = (struct ng_bridge_host_ary *)resp->data; 493 ary->numHosts = priv->numHosts; 494 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 495 SLIST_FOREACH(hent, &priv->tab[bucket], next) 496 ary->hosts[i++] = hent->host; 497 } 498 break; 499 } 500 default: 501 error = EINVAL; 502 break; 503 } 504 break; 505 default: 506 error = EINVAL; 507 break; 508 } 509 510 /* Done */ 511 NG_RESPOND_MSG(error, node, item, resp); 512 NG_FREE_MSG(msg); 513 return (error); 514 } 515 516 /* 517 * Receive data on a hook 518 */ 519 static int 520 ng_bridge_rcvdata(hook_p hook, item_p item) 521 { 522 const node_p node = NG_HOOK_NODE(hook); 523 const priv_p priv = NG_NODE_PRIVATE(node); 524 struct ng_bridge_host *host; 525 struct ng_bridge_link *link; 526 struct ether_header *eh; 527 int error = 0, linkNum; 528 int manycast; 529 struct mbuf *m; 530 meta_p meta; 531 struct ng_bridge_link *firstLink; 532 533 NGI_GET_M(item, m); 534 /* Get link number */ 535 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook); 536 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 537 ("%s: linkNum=%u", __func__, linkNum)); 538 link = priv->links[linkNum]; 539 KASSERT(link != NULL, ("%s: link%d null", __func__, linkNum)); 540 541 /* Sanity check packet and pull up header */ 542 if (m->m_pkthdr.len < ETHER_HDR_LEN) { 543 link->stats.recvRunts++; 544 NG_FREE_ITEM(item); 545 NG_FREE_M(m); 546 return (EINVAL); 547 } 548 if (m->m_len < ETHER_HDR_LEN && !(m = m_pullup(m, ETHER_HDR_LEN))) { 549 link->stats.memoryFailures++; 550 NG_FREE_ITEM(item); 551 return (ENOBUFS); 552 } 553 eh = mtod(m, struct ether_header *); 554 if ((eh->ether_shost[0] & 1) != 0) { 555 link->stats.recvInvalid++; 556 NG_FREE_ITEM(item); 557 NG_FREE_M(m); 558 return (EINVAL); 559 } 560 561 /* Is link disabled due to a loopback condition? */ 562 if (link->loopCount != 0) { 563 link->stats.loopDrops++; 564 NG_FREE_ITEM(item); 565 NG_FREE_M(m); 566 return (ELOOP); /* XXX is this an appropriate error? */ 567 } 568 569 /* Update stats */ 570 link->stats.recvPackets++; 571 link->stats.recvOctets += m->m_pkthdr.len; 572 if ((manycast = (eh->ether_dhost[0] & 1)) != 0) { 573 if (ETHER_EQUAL(eh->ether_dhost, ng_bridge_bcast_addr)) { 574 link->stats.recvBroadcasts++; 575 manycast = 2; 576 } else 577 link->stats.recvMulticasts++; 578 } 579 580 /* Look up packet's source Ethernet address in hashtable */ 581 if ((host = ng_bridge_get(priv, eh->ether_shost)) != NULL) { 582 583 /* Update time since last heard from this host */ 584 host->staleness = 0; 585 586 /* Did host jump to a different link? */ 587 if (host->linkNum != linkNum) { 588 589 /* 590 * If the host's old link was recently established 591 * on the old link and it's already jumped to a new 592 * link, declare a loopback condition. 593 */ 594 if (host->age < priv->conf.minStableAge) { 595 596 /* Log the problem */ 597 if (priv->conf.debugLevel >= 2) { 598 struct ifnet *ifp = m->m_pkthdr.rcvif; 599 char suffix[32]; 600 601 if (ifp != NULL) 602 snprintf(suffix, sizeof(suffix), 603 " (%s)", ifp->if_xname); 604 else 605 *suffix = '\0'; 606 log(LOG_WARNING, "ng_bridge: %s:" 607 " loopback detected on %s%s\n", 608 ng_bridge_nodename(node), 609 NG_HOOK_NAME(hook), suffix); 610 } 611 612 /* Mark link as linka non grata */ 613 link->loopCount = priv->conf.loopTimeout; 614 link->stats.loopDetects++; 615 616 /* Forget all hosts on this link */ 617 ng_bridge_remove_hosts(priv, linkNum); 618 619 /* Drop packet */ 620 link->stats.loopDrops++; 621 NG_FREE_ITEM(item); 622 NG_FREE_M(m); 623 return (ELOOP); /* XXX appropriate? */ 624 } 625 626 /* Move host over to new link */ 627 host->linkNum = linkNum; 628 host->age = 0; 629 } 630 } else { 631 if (!ng_bridge_put(priv, eh->ether_shost, linkNum)) { 632 link->stats.memoryFailures++; 633 NG_FREE_ITEM(item); 634 NG_FREE_M(m); 635 return (ENOMEM); 636 } 637 } 638 639 /* Run packet through ipfw processing, if enabled */ 640 if (priv->conf.ipfw[linkNum] && fw_enable && ip_fw_chk_ptr != NULL) { 641 /* XXX not implemented yet */ 642 } 643 644 /* 645 * If unicast and destination host known, deliver to host's link, 646 * unless it is the same link as the packet came in on. 647 */ 648 if (!manycast) { 649 650 /* Determine packet destination link */ 651 if ((host = ng_bridge_get(priv, eh->ether_dhost)) != NULL) { 652 struct ng_bridge_link *const destLink 653 = priv->links[host->linkNum]; 654 655 /* If destination same as incoming link, do nothing */ 656 KASSERT(destLink != NULL, 657 ("%s: link%d null", __func__, host->linkNum)); 658 if (destLink == link) { 659 NG_FREE_ITEM(item); 660 NG_FREE_M(m); 661 return (0); 662 } 663 664 /* Deliver packet out the destination link */ 665 destLink->stats.xmitPackets++; 666 destLink->stats.xmitOctets += m->m_pkthdr.len; 667 NG_FWD_NEW_DATA(error, item, destLink->hook, m); 668 return (error); 669 } 670 671 /* Destination host is not known */ 672 link->stats.recvUnknown++; 673 } 674 675 /* Distribute unknown, multicast, broadcast pkts to all other links */ 676 meta = NGI_META(item); /* peek.. */ 677 firstLink = NULL; 678 for (linkNum = 0; linkNum <= priv->numLinks; linkNum++) { 679 struct ng_bridge_link *destLink; 680 meta_p meta2 = NULL; 681 struct mbuf *m2 = NULL; 682 683 /* 684 * If we have checked all the links then now 685 * send the original on its reserved link 686 */ 687 if (linkNum == priv->numLinks) { 688 /* If we never saw a good link, leave. */ 689 if (firstLink == NULL) { 690 NG_FREE_ITEM(item); 691 NG_FREE_M(m); 692 return (0); 693 } 694 destLink = firstLink; 695 } else { 696 destLink = priv->links[linkNum]; 697 /* Skip incoming link and disconnected links */ 698 if (destLink == NULL || destLink == link) { 699 continue; 700 } 701 if (firstLink == NULL) { 702 /* 703 * This is the first usable link we have found. 704 * Reserve it for the originals. 705 * If we never find another we save a copy. 706 */ 707 firstLink = destLink; 708 continue; 709 } 710 711 /* 712 * It's usable link but not the reserved (first) one. 713 * Copy mbuf and meta info for sending. 714 */ 715 m2 = m_dup(m, M_DONTWAIT); /* XXX m_copypacket() */ 716 if (m2 == NULL) { 717 link->stats.memoryFailures++; 718 NG_FREE_ITEM(item); 719 NG_FREE_M(m); 720 return (ENOBUFS); 721 } 722 if (meta != NULL 723 && (meta2 = ng_copy_meta(meta)) == NULL) { 724 link->stats.memoryFailures++; 725 m_freem(m2); 726 NG_FREE_ITEM(item); 727 NG_FREE_M(m); 728 return (ENOMEM); 729 } 730 } 731 732 /* Update stats */ 733 destLink->stats.xmitPackets++; 734 destLink->stats.xmitOctets += m->m_pkthdr.len; 735 switch (manycast) { 736 case 0: /* unicast */ 737 break; 738 case 1: /* multicast */ 739 destLink->stats.xmitMulticasts++; 740 break; 741 case 2: /* broadcast */ 742 destLink->stats.xmitBroadcasts++; 743 break; 744 } 745 746 /* Send packet */ 747 if (destLink == firstLink) { 748 /* 749 * If we've sent all the others, send the original 750 * on the first link we found. 751 */ 752 NG_FWD_NEW_DATA(error, item, destLink->hook, m); 753 break; /* always done last - not really needed. */ 754 } else { 755 NG_SEND_DATA(error, destLink->hook, m2, meta2); 756 } 757 } 758 return (error); 759 } 760 761 /* 762 * Shutdown node 763 */ 764 static int 765 ng_bridge_shutdown(node_p node) 766 { 767 const priv_p priv = NG_NODE_PRIVATE(node); 768 769 /* 770 * Shut down everything except the timer. There's no way to 771 * avoid another possible timeout event (it may have already 772 * been dequeued), so we can't free the node yet. 773 */ 774 KASSERT(priv->numLinks == 0 && priv->numHosts == 0, 775 ("%s: numLinks=%d numHosts=%d", 776 __func__, priv->numLinks, priv->numHosts)); 777 FREE(priv->tab, M_NETGRAPH_BRIDGE); 778 779 /* NG_INVALID flag is now set so node will be freed at next timeout */ 780 return (0); 781 } 782 783 /* 784 * Hook disconnection. 785 */ 786 static int 787 ng_bridge_disconnect(hook_p hook) 788 { 789 const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); 790 int linkNum; 791 792 /* Get link number */ 793 linkNum = (intptr_t)NG_HOOK_PRIVATE(hook); 794 KASSERT(linkNum >= 0 && linkNum < NG_BRIDGE_MAX_LINKS, 795 ("%s: linkNum=%u", __func__, linkNum)); 796 797 /* Remove all hosts associated with this link */ 798 ng_bridge_remove_hosts(priv, linkNum); 799 800 /* Free associated link information */ 801 KASSERT(priv->links[linkNum] != NULL, ("%s: no link", __func__)); 802 FREE(priv->links[linkNum], M_NETGRAPH_BRIDGE); 803 priv->links[linkNum] = NULL; 804 priv->numLinks--; 805 806 /* If no more hooks, go away */ 807 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) 808 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) { 809 ng_rmnode_self(NG_HOOK_NODE(hook)); 810 } 811 return (0); 812 } 813 814 /****************************************************************** 815 HASH TABLE FUNCTIONS 816 ******************************************************************/ 817 818 /* 819 * Hash algorithm 820 * 821 * Only hashing bytes 3-6 of the Ethernet address is sufficient and fast. 822 */ 823 #define HASH(addr,mask) ( (((const u_int16_t *)(addr))[0] \ 824 ^ ((const u_int16_t *)(addr))[1] \ 825 ^ ((const u_int16_t *)(addr))[2]) & (mask) ) 826 827 /* 828 * Find a host entry in the table. 829 */ 830 static struct ng_bridge_host * 831 ng_bridge_get(priv_p priv, const u_char *addr) 832 { 833 const int bucket = HASH(addr, priv->hashMask); 834 struct ng_bridge_hent *hent; 835 836 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 837 if (ETHER_EQUAL(hent->host.addr, addr)) 838 return (&hent->host); 839 } 840 return (NULL); 841 } 842 843 /* 844 * Add a new host entry to the table. This assumes the host doesn't 845 * already exist in the table. Returns 1 on success, 0 if there 846 * was a memory allocation failure. 847 */ 848 static int 849 ng_bridge_put(priv_p priv, const u_char *addr, int linkNum) 850 { 851 const int bucket = HASH(addr, priv->hashMask); 852 struct ng_bridge_hent *hent; 853 854 #ifdef INVARIANTS 855 /* Assert that entry does not already exist in hashtable */ 856 SLIST_FOREACH(hent, &priv->tab[bucket], next) { 857 KASSERT(!ETHER_EQUAL(hent->host.addr, addr), 858 ("%s: entry %6D exists in table", __func__, addr, ":")); 859 } 860 #endif 861 862 /* Allocate and initialize new hashtable entry */ 863 MALLOC(hent, struct ng_bridge_hent *, 864 sizeof(*hent), M_NETGRAPH_BRIDGE, M_NOWAIT); 865 if (hent == NULL) 866 return (0); 867 bcopy(addr, hent->host.addr, ETHER_ADDR_LEN); 868 hent->host.linkNum = linkNum; 869 hent->host.staleness = 0; 870 hent->host.age = 0; 871 872 /* Add new element to hash bucket */ 873 SLIST_INSERT_HEAD(&priv->tab[bucket], hent, next); 874 priv->numHosts++; 875 876 /* Resize table if necessary */ 877 ng_bridge_rehash(priv); 878 return (1); 879 } 880 881 /* 882 * Resize the hash table. We try to maintain the number of buckets 883 * such that the load factor is in the range 0.25 to 1.0. 884 * 885 * If we can't get the new memory then we silently fail. This is OK 886 * because things will still work and we'll try again soon anyway. 887 */ 888 static void 889 ng_bridge_rehash(priv_p priv) 890 { 891 struct ng_bridge_bucket *newTab; 892 int oldBucket, newBucket; 893 int newNumBuckets; 894 u_int newMask; 895 896 /* Is table too full or too empty? */ 897 if (priv->numHosts > priv->numBuckets 898 && (priv->numBuckets << 1) <= MAX_BUCKETS) 899 newNumBuckets = priv->numBuckets << 1; 900 else if (priv->numHosts < (priv->numBuckets >> 2) 901 && (priv->numBuckets >> 2) >= MIN_BUCKETS) 902 newNumBuckets = priv->numBuckets >> 2; 903 else 904 return; 905 newMask = newNumBuckets - 1; 906 907 /* Allocate and initialize new table */ 908 MALLOC(newTab, struct ng_bridge_bucket *, 909 newNumBuckets * sizeof(*newTab), M_NETGRAPH_BRIDGE, M_NOWAIT | M_ZERO); 910 if (newTab == NULL) 911 return; 912 913 /* Move all entries from old table to new table */ 914 for (oldBucket = 0; oldBucket < priv->numBuckets; oldBucket++) { 915 struct ng_bridge_bucket *const oldList = &priv->tab[oldBucket]; 916 917 while (!SLIST_EMPTY(oldList)) { 918 struct ng_bridge_hent *const hent 919 = SLIST_FIRST(oldList); 920 921 SLIST_REMOVE_HEAD(oldList, next); 922 newBucket = HASH(hent->host.addr, newMask); 923 SLIST_INSERT_HEAD(&newTab[newBucket], hent, next); 924 } 925 } 926 927 /* Replace old table with new one */ 928 if (priv->conf.debugLevel >= 3) { 929 log(LOG_INFO, "ng_bridge: %s: table size %d -> %d\n", 930 ng_bridge_nodename(priv->node), 931 priv->numBuckets, newNumBuckets); 932 } 933 FREE(priv->tab, M_NETGRAPH_BRIDGE); 934 priv->numBuckets = newNumBuckets; 935 priv->hashMask = newMask; 936 priv->tab = newTab; 937 return; 938 } 939 940 /****************************************************************** 941 MISC FUNCTIONS 942 ******************************************************************/ 943 944 /* 945 * Remove all hosts associated with a specific link from the hashtable. 946 * If linkNum == -1, then remove all hosts in the table. 947 */ 948 static void 949 ng_bridge_remove_hosts(priv_p priv, int linkNum) 950 { 951 int bucket; 952 953 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 954 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 955 956 while (*hptr != NULL) { 957 struct ng_bridge_hent *const hent = *hptr; 958 959 if (linkNum == -1 || hent->host.linkNum == linkNum) { 960 *hptr = SLIST_NEXT(hent, next); 961 FREE(hent, M_NETGRAPH_BRIDGE); 962 priv->numHosts--; 963 } else 964 hptr = &SLIST_NEXT(hent, next); 965 } 966 } 967 } 968 969 /* 970 * Handle our once-per-second timeout event. We do two things: 971 * we decrement link->loopCount for those links being muted due to 972 * a detected loopback condition, and we remove any hosts from 973 * the hashtable whom we haven't heard from in a long while. 974 * 975 * If the node has the NG_INVALID flag set, our job is to kill it. 976 */ 977 static void 978 ng_bridge_timeout(void *arg) 979 { 980 const node_p node = arg; 981 const priv_p priv = NG_NODE_PRIVATE(node); 982 int s, bucket; 983 int counter = 0; 984 int linkNum; 985 986 /* If node was shut down, this is the final lingering timeout */ 987 s = splnet(); 988 if (NG_NODE_NOT_VALID(node)) { 989 FREE(priv, M_NETGRAPH_BRIDGE); 990 NG_NODE_SET_PRIVATE(node, NULL); 991 NG_NODE_UNREF(node); 992 splx(s); 993 return; 994 } 995 996 /* Register a new timeout, keeping the existing node reference */ 997 callout_reset(&priv->timer, hz, ng_bridge_timeout, node); 998 999 /* Update host time counters and remove stale entries */ 1000 for (bucket = 0; bucket < priv->numBuckets; bucket++) { 1001 struct ng_bridge_hent **hptr = &SLIST_FIRST(&priv->tab[bucket]); 1002 1003 while (*hptr != NULL) { 1004 struct ng_bridge_hent *const hent = *hptr; 1005 1006 /* Make sure host's link really exists */ 1007 KASSERT(priv->links[hent->host.linkNum] != NULL, 1008 ("%s: host %6D on nonexistent link %d\n", 1009 __func__, hent->host.addr, ":", 1010 hent->host.linkNum)); 1011 1012 /* Remove hosts we haven't heard from in a while */ 1013 if (++hent->host.staleness >= priv->conf.maxStaleness) { 1014 *hptr = SLIST_NEXT(hent, next); 1015 FREE(hent, M_NETGRAPH_BRIDGE); 1016 priv->numHosts--; 1017 } else { 1018 if (hent->host.age < 0xffff) 1019 hent->host.age++; 1020 hptr = &SLIST_NEXT(hent, next); 1021 counter++; 1022 } 1023 } 1024 } 1025 KASSERT(priv->numHosts == counter, 1026 ("%s: hosts: %d != %d", __func__, priv->numHosts, counter)); 1027 1028 /* Decrease table size if necessary */ 1029 ng_bridge_rehash(priv); 1030 1031 /* Decrease loop counter on muted looped back links */ 1032 for (counter = linkNum = 0; linkNum < NG_BRIDGE_MAX_LINKS; linkNum++) { 1033 struct ng_bridge_link *const link = priv->links[linkNum]; 1034 1035 if (link != NULL) { 1036 if (link->loopCount != 0) { 1037 link->loopCount--; 1038 if (link->loopCount == 0 1039 && priv->conf.debugLevel >= 2) { 1040 log(LOG_INFO, "ng_bridge: %s:" 1041 " restoring looped back link%d\n", 1042 ng_bridge_nodename(node), linkNum); 1043 } 1044 } 1045 counter++; 1046 } 1047 } 1048 KASSERT(priv->numLinks == counter, 1049 ("%s: links: %d != %d", __func__, priv->numLinks, counter)); 1050 1051 /* Done */ 1052 splx(s); 1053 } 1054 1055 /* 1056 * Return node's "name", even if it doesn't have one. 1057 */ 1058 static const char * 1059 ng_bridge_nodename(node_p node) 1060 { 1061 static char name[NG_NODELEN+1]; 1062 1063 if (NG_NODE_NAME(node) != NULL) 1064 snprintf(name, sizeof(name), "%s", NG_NODE_NAME(node)); 1065 else 1066 snprintf(name, sizeof(name), "[%x]", ng_node2ID(node)); 1067 return name; 1068 } 1069
Cache object: 60d831b06a10761a5f98340317516a6e
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