net/tipc/bcast.c

   1 /*
   2  * net/tipc/bcast.c: TIPC broadcast code
   3  *
   4  * Copyright (c) 2004-2006, 2014-2015, 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 "name_distr.h"
  43 #include "link.h"
  44 #include "node.h"
  45
  46 #define BCLINK_WIN_DEFAULT      50      /* bcast link window size (default) */
  47 #define BCLINK_WIN_MIN          32      /* bcast minimum link window size */
  48
  49 const char tipc_bclink_name[] = "broadcast-link";
  50
  51 /**
  52  * struct tipc_bc_base - base structure for keeping broadcast send state
  53  * @link: broadcast send link structure
  54  * @inputq: data input queue; will only carry SOCK_WAKEUP messages
  55  * @dest: array keeping number of reachable destinations per bearer
  56  * @primary_bearer: a bearer having links to all broadcast destinations, if any
  57  */
  58 struct tipc_bc_base {
  59         struct tipc_link *link;
  60         struct sk_buff_head inputq;
  61         int dests[MAX_BEARERS];
  62         int primary_bearer;
  63 };
  64
  65 static struct tipc_bc_base *tipc_bc_base(struct net *net)
  66 {
  67         return tipc_net(net)->bcbase;
  68 }
  69
  70 int tipc_bcast_get_mtu(struct net *net)
  71 {
  72         return tipc_link_mtu(tipc_bc_sndlink(net));
  73 }
  74
  75 /* tipc_bcbase_select_primary(): find a bearer with links to all destinations,
  76  *                               if any, and make it primary bearer
  77  */
  78 static void tipc_bcbase_select_primary(struct net *net)
  79 {
  80         struct tipc_bc_base *bb = tipc_bc_base(net);
  81         int all_dests =  tipc_link_bc_peers(bb->link);
  82         int i, mtu;
  83
  84         bb->primary_bearer = INVALID_BEARER_ID;
  85
  86         if (!all_dests)
  87                 return;
  88
  89         for (i = 0; i < MAX_BEARERS; i++) {
  90                 if (!bb->dests[i])
  91                         continue;
  92
  93                 mtu = tipc_bearer_mtu(net, i);
  94                 if (mtu < tipc_link_mtu(bb->link))
  95                         tipc_link_set_mtu(bb->link, mtu);
  96
  97                 if (bb->dests[i] < all_dests)
  98                         continue;
  99
 100                 bb->primary_bearer = i;
 101
 102                 /* Reduce risk that all nodes select same primary */
 103                 if ((i ^ tipc_own_addr(net)) & 1)
 104                         break;
 105         }
 106 }
 107
 108 void tipc_bcast_inc_bearer_dst_cnt(struct net *net, int bearer_id)
 109 {
 110         struct tipc_bc_base *bb = tipc_bc_base(net);
 111
 112         tipc_bcast_lock(net);
 113         bb->dests[bearer_id]++;
 114         tipc_bcbase_select_primary(net);
 115         tipc_bcast_unlock(net);
 116 }
 117
 118 void tipc_bcast_dec_bearer_dst_cnt(struct net *net, int bearer_id)
 119 {
 120         struct tipc_bc_base *bb = tipc_bc_base(net);
 121
 122         tipc_bcast_lock(net);
 123         bb->dests[bearer_id]--;
 124         tipc_bcbase_select_primary(net);
 125         tipc_bcast_unlock(net);
 126 }
 127
 128 /* tipc_bcbase_xmit - broadcast a packet queue across one or more bearers
 129  *
 130  * Note that number of reachable destinations, as indicated in the dests[]
 131  * array, may transitionally differ from the number of destinations indicated
 132  * in each sent buffer. We can sustain this. Excess destination nodes will
 133  * drop and never acknowledge the unexpected packets, and missing destinations
 134  * will either require retransmission (if they are just about to be added to
 135  * the bearer), or be removed from the buffer's 'ackers' counter (if they
 136  * just went down)
 137  */
 138 static void tipc_bcbase_xmit(struct net *net, struct sk_buff_head *xmitq)
 139 {
 140         int bearer_id;
 141         struct tipc_bc_base *bb = tipc_bc_base(net);
 142         struct sk_buff *skb, *_skb;
 143         struct sk_buff_head _xmitq;
 144
 145         if (skb_queue_empty(xmitq))
 146                 return;
 147
 148         /* The typical case: at least one bearer has links to all nodes */
 149         bearer_id = bb->primary_bearer;
 150         if (bearer_id >= 0) {
 151                 tipc_bearer_bc_xmit(net, bearer_id, xmitq);
 152                 return;
 153         }
 154
 155         /* We have to transmit across all bearers */
 156         skb_queue_head_init(&_xmitq);
 157         for (bearer_id = 0; bearer_id < MAX_BEARERS; bearer_id++) {
 158                 if (!bb->dests[bearer_id])
 159                         continue;
 160
 161                 skb_queue_walk(xmitq, skb) {
 162                         _skb = pskb_copy_for_clone(skb, GFP_ATOMIC);
 163                         if (!_skb)
 164                                 break;
 165                         __skb_queue_tail(&_xmitq, _skb);
 166                 }
 167                 tipc_bearer_bc_xmit(net, bearer_id, &_xmitq);
 168         }
 169         __skb_queue_purge(xmitq);
 170         __skb_queue_purge(&_xmitq);
 171 }
 172
 173 /* tipc_bcast_xmit - deliver buffer chain to all nodes in cluster
 174  *                    and to identified node local sockets
 175  * @net: the applicable net namespace
 176  * @list: chain of buffers containing message
 177  * Consumes the buffer chain, except when returning -ELINKCONG
 178  * Returns 0 if success, otherwise errno: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE
 179  */
 180 int tipc_bcast_xmit(struct net *net, struct sk_buff_head *list)
 181 {
 182         struct tipc_link *l = tipc_bc_sndlink(net);
 183         struct sk_buff_head xmitq, inputq, rcvq;
 184         int rc = 0;
 185
 186         __skb_queue_head_init(&rcvq);
 187         __skb_queue_head_init(&xmitq);
 188         skb_queue_head_init(&inputq);
 189
 190         /* Prepare message clone for local node */
 191         if (unlikely(!tipc_msg_reassemble(list, &rcvq)))
 192                 return -EHOSTUNREACH;
 193
 194         tipc_bcast_lock(net);
 195         if (tipc_link_bc_peers(l))
 196                 rc = tipc_link_xmit(l, list, &xmitq);
 197         tipc_bcast_unlock(net);
 198
 199         /* Don't send to local node if adding to link failed */
 200         if (unlikely(rc)) {
 201                 __skb_queue_purge(&rcvq);
 202                 return rc;
 203         }
 204
 205         /* Broadcast to all nodes, inluding local node */
 206         tipc_bcbase_xmit(net, &xmitq);
 207         tipc_sk_mcast_rcv(net, &rcvq, &inputq);
 208         __skb_queue_purge(list);
 209         return 0;
 210 }
 211
 212 /* tipc_bcast_rcv - receive a broadcast packet, and deliver to rcv link
 213  *
 214  * RCU is locked, no other locks set
 215  */
 216 int tipc_bcast_rcv(struct net *net, struct tipc_link *l, struct sk_buff *skb)
 217 {
 218         struct tipc_msg *hdr = buf_msg(skb);
 219         struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
 220         struct sk_buff_head xmitq;
 221         int rc;
 222
 223         __skb_queue_head_init(&xmitq);
 224
 225         if (msg_mc_netid(hdr) != tipc_netid(net) || !tipc_link_is_up(l)) {
 226                 kfree_skb(skb);
 227                 return 0;
 228         }
 229
 230         tipc_bcast_lock(net);
 231         if (msg_user(hdr) == BCAST_PROTOCOL)
 232                 rc = tipc_link_bc_nack_rcv(l, skb, &xmitq);
 233         else
 234                 rc = tipc_link_rcv(l, skb, NULL);
 235         tipc_bcast_unlock(net);
 236
 237         tipc_bcbase_xmit(net, &xmitq);
 238
 239         /* Any socket wakeup messages ? */
 240         if (!skb_queue_empty(inputq))
 241                 tipc_sk_rcv(net, inputq);
 242
 243         return rc;
 244 }
 245
 246 /* tipc_bcast_ack_rcv - receive and handle a broadcast acknowledge
 247  *
 248  * RCU is locked, no other locks set
 249  */
 250 void tipc_bcast_ack_rcv(struct net *net, struct tipc_link *l, u32 acked)
 251 {
 252         struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
 253         struct sk_buff_head xmitq;
 254
 255         __skb_queue_head_init(&xmitq);
 256
 257         tipc_bcast_lock(net);
 258         tipc_link_bc_ack_rcv(l, acked, &xmitq);
 259         tipc_bcast_unlock(net);
 260
 261         tipc_bcbase_xmit(net, &xmitq);
 262
 263         /* Any socket wakeup messages ? */
 264         if (!skb_queue_empty(inputq))
 265                 tipc_sk_rcv(net, inputq);
 266 }
 267
 268 /* tipc_bcast_synch_rcv -  check and update rcv link with peer's send state
 269  *
 270  * RCU is locked, no other locks set
 271  */
 272 void tipc_bcast_sync_rcv(struct net *net, struct tipc_link *l,
 273                          struct tipc_msg *hdr)
 274 {
 275         struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
 276         struct sk_buff_head xmitq;
 277
 278         __skb_queue_head_init(&xmitq);
 279
 280         tipc_bcast_lock(net);
 281         if (msg_type(hdr) == STATE_MSG) {
 282                 tipc_link_bc_ack_rcv(l, msg_bcast_ack(hdr), &xmitq);
 283                 tipc_link_bc_sync_rcv(l, hdr, &xmitq);
 284         } else {
 285                 tipc_link_bc_init_rcv(l, hdr);
 286         }
 287         tipc_bcast_unlock(net);
 288
 289         tipc_bcbase_xmit(net, &xmitq);
 290
 291         /* Any socket wakeup messages ? */
 292         if (!skb_queue_empty(inputq))
 293                 tipc_sk_rcv(net, inputq);
 294 }
 295
 296 /* tipc_bcast_add_peer - add a peer node to broadcast link and bearer
 297  *
 298  * RCU is locked, node lock is set
 299  */
 300 void tipc_bcast_add_peer(struct net *net, struct tipc_link *uc_l,
 301                          struct sk_buff_head *xmitq)
 302 {
 303         struct tipc_link *snd_l = tipc_bc_sndlink(net);
 304
 305         tipc_bcast_lock(net);
 306         tipc_link_add_bc_peer(snd_l, uc_l, xmitq);
 307         tipc_bcbase_select_primary(net);
 308         tipc_bcast_unlock(net);
 309 }
 310
 311 /* tipc_bcast_remove_peer - remove a peer node from broadcast link and bearer
 312  *
 313  * RCU is locked, node lock is set
 314  */
 315 void tipc_bcast_remove_peer(struct net *net, struct tipc_link *rcv_l)
 316 {
 317         struct tipc_link *snd_l = tipc_bc_sndlink(net);
 318         struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
 319         struct sk_buff_head xmitq;
 320
 321         __skb_queue_head_init(&xmitq);
 322
 323         tipc_bcast_lock(net);
 324         tipc_link_remove_bc_peer(snd_l, rcv_l, &xmitq);
 325         tipc_bcbase_select_primary(net);
 326         tipc_bcast_unlock(net);
 327
 328         tipc_bcbase_xmit(net, &xmitq);
 329
 330         /* Any socket wakeup messages ? */
 331         if (!skb_queue_empty(inputq))
 332                 tipc_sk_rcv(net, inputq);
 333 }
 334
 335 int tipc_bclink_reset_stats(struct net *net)
 336 {
 337         struct tipc_link *l = tipc_bc_sndlink(net);
 338
 339         if (!l)
 340                 return -ENOPROTOOPT;
 341
 342         tipc_bcast_lock(net);
 343         tipc_link_reset_stats(l);
 344         tipc_bcast_unlock(net);
 345         return 0;
 346 }
 347
 348 static int tipc_bc_link_set_queue_limits(struct net *net, u32 limit)
 349 {
 350         struct tipc_link *l = tipc_bc_sndlink(net);
 351
 352         if (!l)
 353                 return -ENOPROTOOPT;
 354         if (limit < BCLINK_WIN_MIN)
 355                 limit = BCLINK_WIN_MIN;
 356         if (limit > TIPC_MAX_LINK_WIN)
 357                 return -EINVAL;
 358         tipc_bcast_lock(net);
 359         tipc_link_set_queue_limits(l, limit);
 360         tipc_bcast_unlock(net);
 361         return 0;
 362 }
 363
 364 int tipc_nl_bc_link_set(struct net *net, struct nlattr *attrs[])
 365 {
 366         int err;
 367         u32 win;
 368         struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
 369
 370         if (!attrs[TIPC_NLA_LINK_PROP])
 371                 return -EINVAL;
 372
 373         err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP], props);
 374         if (err)
 375                 return err;
 376
 377         if (!props[TIPC_NLA_PROP_WIN])
 378                 return -EOPNOTSUPP;
 379
 380         win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
 381
 382         return tipc_bc_link_set_queue_limits(net, win);
 383 }
 384
 385 int tipc_bcast_init(struct net *net)
 386 {
 387         struct tipc_net *tn = tipc_net(net);
 388         struct tipc_bc_base *bb = NULL;
 389         struct tipc_link *l = NULL;
 390
 391         bb = kzalloc(sizeof(*bb), GFP_ATOMIC);
 392         if (!bb)
 393                 goto enomem;
 394         tn->bcbase = bb;
 395         spin_lock_init(&tipc_net(net)->bclock);
 396
 397         if (!tipc_link_bc_create(net, 0, 0,
 398                                  U16_MAX,
 399                                  BCLINK_WIN_DEFAULT,
 400                                  0,
 401                                  &bb->inputq,
 402                                  NULL,
 403                                  NULL,
 404                                  &l))
 405                 goto enomem;
 406         bb->link = l;
 407         tn->bcl = l;
 408         return 0;
 409 enomem:
 410         kfree(bb);
 411         kfree(l);
 412         return -ENOMEM;
 413 }
 414
 415 void tipc_bcast_stop(struct net *net)
 416 {
 417         struct tipc_net *tn = net_generic(net, tipc_net_id);
 418
 419         synchronize_net();
 420         kfree(tn->bcbase);
 421         kfree(tn->bcl);
 422 }