1 /* 2 * net/tipc/bcast.c: TIPC broadcast code 3 * 4 * Copyright (c) 2004-2006, 2014-2016, Ericsson AB 5 * Copyright (c) 2004, Intel Corporation. 6 * Copyright (c) 2005, 2010-2011, Wind River Systems 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the names of the copyright holders nor the names of its 18 * contributors may be used to endorse or promote products derived from 19 * this software without specific prior written permission. 20 * 21 * Alternatively, this software may be distributed under the terms of the 22 * GNU General Public License ("GPL") version 2 as published by the Free 23 * Software Foundation. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 26 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 29 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 35 * POSSIBILITY OF SUCH DAMAGE. 36 */ 37 38 #include <linux/tipc_config.h> 39 #include "socket.h" 40 #include "msg.h" 41 #include "bcast.h" 42 #include "link.h" 43 #include "name_table.h" 44 45 #define BCLINK_WIN_DEFAULT 50 /* bcast link window size (default) */ 46 #define BCLINK_WIN_MIN 32 /* bcast minimum link window size */ 47 48 const char tipc_bclink_name[] = "broadcast-link"; 49 50 /** 51 * struct tipc_bc_base - base structure for keeping broadcast send state 52 * @link: broadcast send link structure 53 * @inputq: data input queue; will only carry SOCK_WAKEUP messages 54 * @dest: array keeping number of reachable destinations per bearer 55 * @primary_bearer: a bearer having links to all broadcast destinations, if any 56 * @bcast_support: indicates if primary bearer, if any, supports broadcast 57 * @rcast_support: indicates if all peer nodes support replicast 58 * @rc_ratio: dest count as percentage of cluster size where send method changes 59 * @bc_threshold: calculated drom rc_ratio; if dests > threshold use broadcast 60 */ 61 struct tipc_bc_base { 62 struct tipc_link *link; 63 struct sk_buff_head inputq; 64 int dests[MAX_BEARERS]; 65 int primary_bearer; 66 bool bcast_support; 67 bool rcast_support; 68 int rc_ratio; 69 int bc_threshold; 70 }; 71 72 static struct tipc_bc_base *tipc_bc_base(struct net *net) 73 { 74 return tipc_net(net)->bcbase; 75 } 76 77 int tipc_bcast_get_mtu(struct net *net) 78 { 79 return tipc_link_mtu(tipc_bc_sndlink(net)) - INT_H_SIZE; 80 } 81 82 void tipc_bcast_disable_rcast(struct net *net) 83 { 84 tipc_bc_base(net)->rcast_support = false; 85 } 86 87 static void tipc_bcbase_calc_bc_threshold(struct net *net) 88 { 89 struct tipc_bc_base *bb = tipc_bc_base(net); 90 int cluster_size = tipc_link_bc_peers(tipc_bc_sndlink(net)); 91 92 bb->bc_threshold = 1 + (cluster_size * bb->rc_ratio / 100); 93 } 94 95 /* tipc_bcbase_select_primary(): find a bearer with links to all destinations, 96 * if any, and make it primary bearer 97 */ 98 static void tipc_bcbase_select_primary(struct net *net) 99 { 100 struct tipc_bc_base *bb = tipc_bc_base(net); 101 int all_dests = tipc_link_bc_peers(bb->link); 102 int i, mtu, prim; 103 104 bb->primary_bearer = INVALID_BEARER_ID; 105 bb->bcast_support = true; 106 107 if (!all_dests) 108 return; 109 110 for (i = 0; i < MAX_BEARERS; i++) { 111 if (!bb->dests[i]) 112 continue; 113 114 mtu = tipc_bearer_mtu(net, i); 115 if (mtu < tipc_link_mtu(bb->link)) 116 tipc_link_set_mtu(bb->link, mtu); 117 bb->bcast_support &= tipc_bearer_bcast_support(net, i); 118 if (bb->dests[i] < all_dests) 119 continue; 120 121 bb->primary_bearer = i; 122 123 /* Reduce risk that all nodes select same primary */ 124 if ((i ^ tipc_own_addr(net)) & 1) 125 break; 126 } 127 prim = bb->primary_bearer; 128 if (prim != INVALID_BEARER_ID) 129 bb->bcast_support = tipc_bearer_bcast_support(net, prim); 130 } 131 132 void tipc_bcast_inc_bearer_dst_cnt(struct net *net, int bearer_id) 133 { 134 struct tipc_bc_base *bb = tipc_bc_base(net); 135 136 tipc_bcast_lock(net); 137 bb->dests[bearer_id]++; 138 tipc_bcbase_select_primary(net); 139 tipc_bcast_unlock(net); 140 } 141 142 void tipc_bcast_dec_bearer_dst_cnt(struct net *net, int bearer_id) 143 { 144 struct tipc_bc_base *bb = tipc_bc_base(net); 145 146 tipc_bcast_lock(net); 147 bb->dests[bearer_id]--; 148 tipc_bcbase_select_primary(net); 149 tipc_bcast_unlock(net); 150 } 151 152 /* tipc_bcbase_xmit - broadcast a packet queue across one or more bearers 153 * 154 * Note that number of reachable destinations, as indicated in the dests[] 155 * array, may transitionally differ from the number of destinations indicated 156 * in each sent buffer. We can sustain this. Excess destination nodes will 157 * drop and never acknowledge the unexpected packets, and missing destinations 158 * will either require retransmission (if they are just about to be added to 159 * the bearer), or be removed from the buffer's 'ackers' counter (if they 160 * just went down) 161 */ 162 static void tipc_bcbase_xmit(struct net *net, struct sk_buff_head *xmitq) 163 { 164 int bearer_id; 165 struct tipc_bc_base *bb = tipc_bc_base(net); 166 struct sk_buff *skb, *_skb; 167 struct sk_buff_head _xmitq; 168 169 if (skb_queue_empty(xmitq)) 170 return; 171 172 /* The typical case: at least one bearer has links to all nodes */ 173 bearer_id = bb->primary_bearer; 174 if (bearer_id >= 0) { 175 tipc_bearer_bc_xmit(net, bearer_id, xmitq); 176 return; 177 } 178 179 /* We have to transmit across all bearers */ 180 skb_queue_head_init(&_xmitq); 181 for (bearer_id = 0; bearer_id < MAX_BEARERS; bearer_id++) { 182 if (!bb->dests[bearer_id]) 183 continue; 184 185 skb_queue_walk(xmitq, skb) { 186 _skb = pskb_copy_for_clone(skb, GFP_ATOMIC); 187 if (!_skb) 188 break; 189 __skb_queue_tail(&_xmitq, _skb); 190 } 191 tipc_bearer_bc_xmit(net, bearer_id, &_xmitq); 192 } 193 __skb_queue_purge(xmitq); 194 __skb_queue_purge(&_xmitq); 195 } 196 197 static void tipc_bcast_select_xmit_method(struct net *net, int dests, 198 struct tipc_mc_method *method) 199 { 200 struct tipc_bc_base *bb = tipc_bc_base(net); 201 unsigned long exp = method->expires; 202 203 /* Broadcast supported by used bearer/bearers? */ 204 if (!bb->bcast_support) { 205 method->rcast = true; 206 return; 207 } 208 /* Any destinations which don't support replicast ? */ 209 if (!bb->rcast_support) { 210 method->rcast = false; 211 return; 212 } 213 /* Can current method be changed ? */ 214 method->expires = jiffies + TIPC_METHOD_EXPIRE; 215 if (method->mandatory || time_before(jiffies, exp)) 216 return; 217 218 /* Determine method to use now */ 219 method->rcast = dests <= bb->bc_threshold; 220 } 221 222 /* tipc_bcast_xmit - broadcast the buffer chain to all external nodes 223 * @net: the applicable net namespace 224 * @pkts: chain of buffers containing message 225 * @cong_link_cnt: set to 1 if broadcast link is congested, otherwise 0 226 * Consumes the buffer chain. 227 * Returns 0 if success, otherwise errno: -EHOSTUNREACH,-EMSGSIZE 228 */ 229 static int tipc_bcast_xmit(struct net *net, struct sk_buff_head *pkts, 230 u16 *cong_link_cnt) 231 { 232 struct tipc_link *l = tipc_bc_sndlink(net); 233 struct sk_buff_head xmitq; 234 int rc = 0; 235 236 skb_queue_head_init(&xmitq); 237 tipc_bcast_lock(net); 238 if (tipc_link_bc_peers(l)) 239 rc = tipc_link_xmit(l, pkts, &xmitq); 240 tipc_bcast_unlock(net); 241 tipc_bcbase_xmit(net, &xmitq); 242 __skb_queue_purge(pkts); 243 if (rc == -ELINKCONG) { 244 *cong_link_cnt = 1; 245 rc = 0; 246 } 247 return rc; 248 } 249 250 /* tipc_rcast_xmit - replicate and send a message to given destination nodes 251 * @net: the applicable net namespace 252 * @pkts: chain of buffers containing message 253 * @dests: list of destination nodes 254 * @cong_link_cnt: returns number of congested links 255 * @cong_links: returns identities of congested links 256 * Returns 0 if success, otherwise errno 257 */ 258 static int tipc_rcast_xmit(struct net *net, struct sk_buff_head *pkts, 259 struct tipc_nlist *dests, u16 *cong_link_cnt) 260 { 261 struct sk_buff_head _pkts; 262 struct u32_item *n, *tmp; 263 u32 dst, selector; 264 265 selector = msg_link_selector(buf_msg(skb_peek(pkts))); 266 skb_queue_head_init(&_pkts); 267 268 list_for_each_entry_safe(n, tmp, &dests->list, list) { 269 dst = n->value; 270 if (!tipc_msg_pskb_copy(dst, pkts, &_pkts)) 271 return -ENOMEM; 272 273 /* Any other return value than -ELINKCONG is ignored */ 274 if (tipc_node_xmit(net, &_pkts, dst, selector) == -ELINKCONG) 275 (*cong_link_cnt)++; 276 } 277 return 0; 278 } 279 280 /* tipc_mcast_xmit - deliver message to indicated destination nodes 281 * and to identified node local sockets 282 * @net: the applicable net namespace 283 * @pkts: chain of buffers containing message 284 * @method: send method to be used 285 * @dests: destination nodes for message. 286 * @cong_link_cnt: returns number of encountered congested destination links 287 * Consumes buffer chain. 288 * Returns 0 if success, otherwise errno 289 */ 290 int tipc_mcast_xmit(struct net *net, struct sk_buff_head *pkts, 291 struct tipc_mc_method *method, struct tipc_nlist *dests, 292 u16 *cong_link_cnt) 293 { 294 struct sk_buff_head inputq, localq; 295 int rc = 0; 296 297 skb_queue_head_init(&inputq); 298 skb_queue_head_init(&localq); 299 300 /* Clone packets before they are consumed by next call */ 301 if (dests->local && !tipc_msg_reassemble(pkts, &localq)) { 302 rc = -ENOMEM; 303 goto exit; 304 } 305 /* Send according to determined transmit method */ 306 if (dests->remote) { 307 tipc_bcast_select_xmit_method(net, dests->remote, method); 308 if (method->rcast) 309 rc = tipc_rcast_xmit(net, pkts, dests, cong_link_cnt); 310 else 311 rc = tipc_bcast_xmit(net, pkts, cong_link_cnt); 312 } 313 314 if (dests->local) 315 tipc_sk_mcast_rcv(net, &localq, &inputq); 316 exit: 317 /* This queue should normally be empty by now */ 318 __skb_queue_purge(pkts); 319 return rc; 320 } 321 322 /* tipc_bcast_rcv - receive a broadcast packet, and deliver to rcv link 323 * 324 * RCU is locked, no other locks set 325 */ 326 int tipc_bcast_rcv(struct net *net, struct tipc_link *l, struct sk_buff *skb) 327 { 328 struct tipc_msg *hdr = buf_msg(skb); 329 struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq; 330 struct sk_buff_head xmitq; 331 int rc; 332 333 __skb_queue_head_init(&xmitq); 334 335 if (msg_mc_netid(hdr) != tipc_netid(net) || !tipc_link_is_up(l)) { 336 kfree_skb(skb); 337 return 0; 338 } 339 340 tipc_bcast_lock(net); 341 if (msg_user(hdr) == BCAST_PROTOCOL) 342 rc = tipc_link_bc_nack_rcv(l, skb, &xmitq); 343 else 344 rc = tipc_link_rcv(l, skb, NULL); 345 tipc_bcast_unlock(net); 346 347 tipc_bcbase_xmit(net, &xmitq); 348 349 /* Any socket wakeup messages ? */ 350 if (!skb_queue_empty(inputq)) 351 tipc_sk_rcv(net, inputq); 352 353 return rc; 354 } 355 356 /* tipc_bcast_ack_rcv - receive and handle a broadcast acknowledge 357 * 358 * RCU is locked, no other locks set 359 */ 360 void tipc_bcast_ack_rcv(struct net *net, struct tipc_link *l, 361 struct tipc_msg *hdr) 362 { 363 struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq; 364 u16 acked = msg_bcast_ack(hdr); 365 struct sk_buff_head xmitq; 366 367 /* Ignore bc acks sent by peer before bcast synch point was received */ 368 if (msg_bc_ack_invalid(hdr)) 369 return; 370 371 __skb_queue_head_init(&xmitq); 372 373 tipc_bcast_lock(net); 374 tipc_link_bc_ack_rcv(l, acked, &xmitq); 375 tipc_bcast_unlock(net); 376 377 tipc_bcbase_xmit(net, &xmitq); 378 379 /* Any socket wakeup messages ? */ 380 if (!skb_queue_empty(inputq)) 381 tipc_sk_rcv(net, inputq); 382 } 383 384 /* tipc_bcast_synch_rcv - check and update rcv link with peer's send state 385 * 386 * RCU is locked, no other locks set 387 */ 388 int tipc_bcast_sync_rcv(struct net *net, struct tipc_link *l, 389 struct tipc_msg *hdr) 390 { 391 struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq; 392 struct sk_buff_head xmitq; 393 int rc = 0; 394 395 __skb_queue_head_init(&xmitq); 396 397 tipc_bcast_lock(net); 398 if (msg_type(hdr) != STATE_MSG) { 399 tipc_link_bc_init_rcv(l, hdr); 400 } else if (!msg_bc_ack_invalid(hdr)) { 401 tipc_link_bc_ack_rcv(l, msg_bcast_ack(hdr), &xmitq); 402 rc = tipc_link_bc_sync_rcv(l, hdr, &xmitq); 403 } 404 tipc_bcast_unlock(net); 405 406 tipc_bcbase_xmit(net, &xmitq); 407 408 /* Any socket wakeup messages ? */ 409 if (!skb_queue_empty(inputq)) 410 tipc_sk_rcv(net, inputq); 411 return rc; 412 } 413 414 /* tipc_bcast_add_peer - add a peer node to broadcast link and bearer 415 * 416 * RCU is locked, node lock is set 417 */ 418 void tipc_bcast_add_peer(struct net *net, struct tipc_link *uc_l, 419 struct sk_buff_head *xmitq) 420 { 421 struct tipc_link *snd_l = tipc_bc_sndlink(net); 422 423 tipc_bcast_lock(net); 424 tipc_link_add_bc_peer(snd_l, uc_l, xmitq); 425 tipc_bcbase_select_primary(net); 426 tipc_bcbase_calc_bc_threshold(net); 427 tipc_bcast_unlock(net); 428 } 429 430 /* tipc_bcast_remove_peer - remove a peer node from broadcast link and bearer 431 * 432 * RCU is locked, node lock is set 433 */ 434 void tipc_bcast_remove_peer(struct net *net, struct tipc_link *rcv_l) 435 { 436 struct tipc_link *snd_l = tipc_bc_sndlink(net); 437 struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq; 438 struct sk_buff_head xmitq; 439 440 __skb_queue_head_init(&xmitq); 441 442 tipc_bcast_lock(net); 443 tipc_link_remove_bc_peer(snd_l, rcv_l, &xmitq); 444 tipc_bcbase_select_primary(net); 445 tipc_bcbase_calc_bc_threshold(net); 446 tipc_bcast_unlock(net); 447 448 tipc_bcbase_xmit(net, &xmitq); 449 450 /* Any socket wakeup messages ? */ 451 if (!skb_queue_empty(inputq)) 452 tipc_sk_rcv(net, inputq); 453 } 454 455 int tipc_bclink_reset_stats(struct net *net) 456 { 457 struct tipc_link *l = tipc_bc_sndlink(net); 458 459 if (!l) 460 return -ENOPROTOOPT; 461 462 tipc_bcast_lock(net); 463 tipc_link_reset_stats(l); 464 tipc_bcast_unlock(net); 465 return 0; 466 } 467 468 static int tipc_bc_link_set_queue_limits(struct net *net, u32 limit) 469 { 470 struct tipc_link *l = tipc_bc_sndlink(net); 471 472 if (!l) 473 return -ENOPROTOOPT; 474 if (limit < BCLINK_WIN_MIN) 475 limit = BCLINK_WIN_MIN; 476 if (limit > TIPC_MAX_LINK_WIN) 477 return -EINVAL; 478 tipc_bcast_lock(net); 479 tipc_link_set_queue_limits(l, limit); 480 tipc_bcast_unlock(net); 481 return 0; 482 } 483 484 int tipc_nl_bc_link_set(struct net *net, struct nlattr *attrs[]) 485 { 486 int err; 487 u32 win; 488 struct nlattr *props[TIPC_NLA_PROP_MAX + 1]; 489 490 if (!attrs[TIPC_NLA_LINK_PROP]) 491 return -EINVAL; 492 493 err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP], props); 494 if (err) 495 return err; 496 497 if (!props[TIPC_NLA_PROP_WIN]) 498 return -EOPNOTSUPP; 499 500 win = nla_get_u32(props[TIPC_NLA_PROP_WIN]); 501 502 return tipc_bc_link_set_queue_limits(net, win); 503 } 504 505 int tipc_bcast_init(struct net *net) 506 { 507 struct tipc_net *tn = tipc_net(net); 508 struct tipc_bc_base *bb = NULL; 509 struct tipc_link *l = NULL; 510 511 bb = kzalloc(sizeof(*bb), GFP_ATOMIC); 512 if (!bb) 513 goto enomem; 514 tn->bcbase = bb; 515 spin_lock_init(&tipc_net(net)->bclock); 516 517 if (!tipc_link_bc_create(net, 0, 0, 518 U16_MAX, 519 BCLINK_WIN_DEFAULT, 520 0, 521 &bb->inputq, 522 NULL, 523 NULL, 524 &l)) 525 goto enomem; 526 bb->link = l; 527 tn->bcl = l; 528 bb->rc_ratio = 25; 529 bb->rcast_support = true; 530 return 0; 531 enomem: 532 kfree(bb); 533 kfree(l); 534 return -ENOMEM; 535 } 536 537 void tipc_bcast_stop(struct net *net) 538 { 539 struct tipc_net *tn = net_generic(net, tipc_net_id); 540 541 synchronize_net(); 542 kfree(tn->bcbase); 543 kfree(tn->bcl); 544 } 545 546 void tipc_nlist_init(struct tipc_nlist *nl, u32 self) 547 { 548 memset(nl, 0, sizeof(*nl)); 549 INIT_LIST_HEAD(&nl->list); 550 nl->self = self; 551 } 552 553 void tipc_nlist_add(struct tipc_nlist *nl, u32 node) 554 { 555 if (node == nl->self) 556 nl->local = true; 557 else if (u32_push(&nl->list, node)) 558 nl->remote++; 559 } 560 561 void tipc_nlist_del(struct tipc_nlist *nl, u32 node) 562 { 563 if (node == nl->self) 564 nl->local = false; 565 else if (u32_del(&nl->list, node)) 566 nl->remote--; 567 } 568 569 void tipc_nlist_purge(struct tipc_nlist *nl) 570 { 571 u32_list_purge(&nl->list); 572 nl->remote = 0; 573 nl->local = 0; 574 } 575