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,
 251                         struct tipc_msg *hdr)
 252 {
 253         struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
 254         u16 acked = msg_bcast_ack(hdr);
 255         struct sk_buff_head xmitq;
 256
 257         /* Ignore bc acks sent by peer before bcast synch point was received */
 258         if (msg_bc_ack_invalid(hdr))
 259                 return;
 260
 261         __skb_queue_head_init(&xmitq);
 262
 263         tipc_bcast_lock(net);
 264         tipc_link_bc_ack_rcv(l, acked, &xmitq);
 265         tipc_bcast_unlock(net);
 266
 267         tipc_bcbase_xmit(net, &xmitq);
 268
 269         /* Any socket wakeup messages ? */
 270         if (!skb_queue_empty(inputq))
 271                 tipc_sk_rcv(net, inputq);
 272 }
 273
 274 /* tipc_bcast_synch_rcv -  check and update rcv link with peer's send state
 275  *
 276  * RCU is locked, no other locks set
 277  */
 278 int tipc_bcast_sync_rcv(struct net *net, struct tipc_link *l,
 279                         struct tipc_msg *hdr)
 280 {
 281         struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
 282         struct sk_buff_head xmitq;
 283         int rc = 0;
 284
 285         __skb_queue_head_init(&xmitq);
 286
 287         tipc_bcast_lock(net);
 288         if (msg_type(hdr) != STATE_MSG) {
 289                 tipc_link_bc_init_rcv(l, hdr);
 290         } else if (!msg_bc_ack_invalid(hdr)) {
 291                 tipc_link_bc_ack_rcv(l, msg_bcast_ack(hdr), &xmitq);
 292                 rc = tipc_link_bc_sync_rcv(l, hdr, &xmitq);
 293         }
 294         tipc_bcast_unlock(net);
 295
 296         tipc_bcbase_xmit(net, &xmitq);
 297
 298         /* Any socket wakeup messages ? */
 299         if (!skb_queue_empty(inputq))
 300                 tipc_sk_rcv(net, inputq);
 301         return rc;
 302 }
 303
 304 /* tipc_bcast_add_peer - add a peer node to broadcast link and bearer
 305  *
 306  * RCU is locked, node lock is set
 307  */
 308 void tipc_bcast_add_peer(struct net *net, struct tipc_link *uc_l,
 309                          struct sk_buff_head *xmitq)
 310 {
 311         struct tipc_link *snd_l = tipc_bc_sndlink(net);
 312
 313         tipc_bcast_lock(net);
 314         tipc_link_add_bc_peer(snd_l, uc_l, xmitq);
 315         tipc_bcbase_select_primary(net);
 316         tipc_bcast_unlock(net);
 317 }
 318
 319 /* tipc_bcast_remove_peer - remove a peer node from broadcast link and bearer
 320  *
 321  * RCU is locked, node lock is set
 322  */
 323 void tipc_bcast_remove_peer(struct net *net, struct tipc_link *rcv_l)
 324 {
 325         struct tipc_link *snd_l = tipc_bc_sndlink(net);
 326         struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
 327         struct sk_buff_head xmitq;
 328
 329         __skb_queue_head_init(&xmitq);
 330
 331         tipc_bcast_lock(net);
 332         tipc_link_remove_bc_peer(snd_l, rcv_l, &xmitq);
 333         tipc_bcbase_select_primary(net);
 334         tipc_bcast_unlock(net);
 335
 336         tipc_bcbase_xmit(net, &xmitq);
 337
 338         /* Any socket wakeup messages ? */
 339         if (!skb_queue_empty(inputq))
 340                 tipc_sk_rcv(net, inputq);
 341 }
 342
 343 int tipc_bclink_reset_stats(struct net *net)
 344 {
 345         struct tipc_link *l = tipc_bc_sndlink(net);
 346
 347         if (!l)
 348                 return -ENOPROTOOPT;
 349
 350         tipc_bcast_lock(net);
 351         tipc_link_reset_stats(l);
 352         tipc_bcast_unlock(net);
 353         return 0;
 354 }
 355
 356 static int tipc_bc_link_set_queue_limits(struct net *net, u32 limit)
 357 {
 358         struct tipc_link *l = tipc_bc_sndlink(net);
 359
 360         if (!l)
 361                 return -ENOPROTOOPT;
 362         if (limit < BCLINK_WIN_MIN)
 363                 limit = BCLINK_WIN_MIN;
 364         if (limit > TIPC_MAX_LINK_WIN)
 365                 return -EINVAL;
 366         tipc_bcast_lock(net);
 367         tipc_link_set_queue_limits(l, limit);
 368         tipc_bcast_unlock(net);
 369         return 0;
 370 }
 371
 372 int tipc_nl_bc_link_set(struct net *net, struct nlattr *attrs[])
 373 {
 374         int err;
 375         u32 win;
 376         struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
 377
 378         if (!attrs[TIPC_NLA_LINK_PROP])
 379                 return -EINVAL;
 380
 381         err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP], props);
 382         if (err)
 383                 return err;
 384
 385         if (!props[TIPC_NLA_PROP_WIN])
 386                 return -EOPNOTSUPP;
 387
 388         win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
 389
 390         return tipc_bc_link_set_queue_limits(net, win);
 391 }
 392
 393 int tipc_bcast_init(struct net *net)
 394 {
 395         struct tipc_net *tn = tipc_net(net);
 396         struct tipc_bc_base *bb = NULL;
 397         struct tipc_link *l = NULL;
 398
 399         bb = kzalloc(sizeof(*bb), GFP_ATOMIC);
 400         if (!bb)
 401                 goto enomem;
 402         tn->bcbase = bb;
 403         spin_lock_init(&tipc_net(net)->bclock);
 404
 405         if (!tipc_link_bc_create(net, 0, 0,
 406                                  U16_MAX,
 407                                  BCLINK_WIN_DEFAULT,
 408                                  0,
 409                                  &bb->inputq,
 410                                  NULL,
 411                                  NULL,
 412                                  &l))
 413                 goto enomem;
 414         bb->link = l;
 415         tn->bcl = l;
 416         return 0;
 417 enomem:
 418         kfree(bb);
 419         kfree(l);
 420         return -ENOMEM;
 421 }
 422
 423 void tipc_bcast_stop(struct net *net)
 424 {
 425         struct tipc_net *tn = net_generic(net, tipc_net_id);
 426
 427         synchronize_net();
 428         kfree(tn->bcbase);
 429         kfree(tn->bcl);
 430 }