net/tipc/name_distr.c

   1 /*
   2  * net/tipc/name_distr.c: TIPC name distribution code
   3  *
   4  * Copyright (c) 2000-2006, 2014, Ericsson AB
   5  * Copyright (c) 2005, 2010-2011, Wind River Systems
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the names of the copyright holders nor the names of its
  17  *    contributors may be used to endorse or promote products derived from
  18  *    this software without specific prior written permission.
  19  *
  20  * Alternatively, this software may be distributed under the terms of the
  21  * GNU General Public License ("GPL") version 2 as published by the Free
  22  * Software Foundation.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  25  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  28  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  31  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  32  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  33  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  34  * POSSIBILITY OF SUCH DAMAGE.
  35  */
  36
  37 #include "core.h"
  38 #include "link.h"
  39 #include "name_distr.h"
  40
  41 int sysctl_tipc_named_timeout __read_mostly = 2000;
  42
  43 struct distr_queue_item {
  44         struct distr_item i;
  45         u32 dtype;
  46         u32 node;
  47         unsigned long expires;
  48         struct list_head next;
  49 };
  50
  51 /**
  52  * publ_to_item - add publication info to a publication message
  53  */
  54 static void publ_to_item(struct distr_item *i, struct publication *p)
  55 {
  56         i->type = htonl(p->type);
  57         i->lower = htonl(p->lower);
  58         i->upper = htonl(p->upper);
  59         i->port = htonl(p->port);
  60         i->key = htonl(p->key);
  61 }
  62
  63 /**
  64  * named_prepare_buf - allocate & initialize a publication message
  65  *
  66  * The buffer returned is of size INT_H_SIZE + payload size
  67  */
  68 static struct sk_buff *named_prepare_buf(struct net *net, u32 type, u32 size,
  69                                          u32 dest)
  70 {
  71         struct sk_buff *buf = tipc_buf_acquire(INT_H_SIZE + size, GFP_ATOMIC);
  72         u32 self = tipc_own_addr(net);
  73         struct tipc_msg *msg;
  74
  75         if (buf != NULL) {
  76                 msg = buf_msg(buf);
  77                 tipc_msg_init(self, msg, NAME_DISTRIBUTOR,
  78                               type, INT_H_SIZE, dest);
  79                 msg_set_size(msg, INT_H_SIZE + size);
  80         }
  81         return buf;
  82 }
  83
  84 /**
  85  * tipc_named_publish - tell other nodes about a new publication by this node
  86  */
  87 struct sk_buff *tipc_named_publish(struct net *net, struct publication *publ)
  88 {
  89         struct name_table *nt = tipc_name_table(net);
  90         struct distr_item *item;
  91         struct sk_buff *skb;
  92
  93         if (publ->scope == TIPC_NODE_SCOPE) {
  94                 list_add_tail_rcu(&publ->binding_node, &nt->node_scope);
  95                 return NULL;
  96         }
  97         write_lock_bh(&nt->cluster_scope_lock);
  98         list_add_tail(&publ->binding_node, &nt->cluster_scope);
  99         write_unlock_bh(&nt->cluster_scope_lock);
 100         skb = named_prepare_buf(net, PUBLICATION, ITEM_SIZE, 0);
 101         if (!skb) {
 102                 pr_warn("Publication distribution failure\n");
 103                 return NULL;
 104         }
 105         msg_set_named_seqno(buf_msg(skb), nt->snd_nxt++);
 106         msg_set_non_legacy(buf_msg(skb));
 107         item = (struct distr_item *)msg_data(buf_msg(skb));
 108         publ_to_item(item, publ);
 109         return skb;
 110 }
 111
 112 /**
 113  * tipc_named_withdraw - tell other nodes about a withdrawn publication by this node
 114  */
 115 struct sk_buff *tipc_named_withdraw(struct net *net, struct publication *publ)
 116 {
 117         struct name_table *nt = tipc_name_table(net);
 118         struct distr_item *item;
 119         struct sk_buff *skb;
 120
 121         write_lock_bh(&nt->cluster_scope_lock);
 122         list_del(&publ->binding_node);
 123         write_unlock_bh(&nt->cluster_scope_lock);
 124         if (publ->scope == TIPC_NODE_SCOPE)
 125                 return NULL;
 126
 127         skb = named_prepare_buf(net, WITHDRAWAL, ITEM_SIZE, 0);
 128         if (!skb) {
 129                 pr_warn("Withdrawal distribution failure\n");
 130                 return NULL;
 131         }
 132         msg_set_named_seqno(buf_msg(skb), nt->snd_nxt++);
 133         msg_set_non_legacy(buf_msg(skb));
 134         item = (struct distr_item *)msg_data(buf_msg(skb));
 135         publ_to_item(item, publ);
 136         return skb;
 137 }
 138
 139 /**
 140  * named_distribute - prepare name info for bulk distribution to another node
 141  * @list: list of messages (buffers) to be returned from this function
 142  * @dnode: node to be updated
 143  * @pls: linked list of publication items to be packed into buffer chain
 144  */
 145 static void named_distribute(struct net *net, struct sk_buff_head *list,
 146                              u32 dnode, struct list_head *pls, u16 seqno)
 147 {
 148         struct publication *publ;
 149         struct sk_buff *skb = NULL;
 150         struct distr_item *item = NULL;
 151         u32 msg_dsz = ((tipc_node_get_mtu(net, dnode, 0, false) - INT_H_SIZE) /
 152                         ITEM_SIZE) * ITEM_SIZE;
 153         u32 msg_rem = msg_dsz;
 154         struct tipc_msg *hdr;
 155
 156         list_for_each_entry(publ, pls, binding_node) {
 157                 /* Prepare next buffer: */
 158                 if (!skb) {
 159                         skb = named_prepare_buf(net, PUBLICATION, msg_rem,
 160                                                 dnode);
 161                         if (!skb) {
 162                                 pr_warn("Bulk publication failure\n");
 163                                 return;
 164                         }
 165                         hdr = buf_msg(skb);
 166                         msg_set_bc_ack_invalid(hdr, true);
 167                         msg_set_bulk(hdr);
 168                         msg_set_non_legacy(hdr);
 169                         item = (struct distr_item *)msg_data(hdr);
 170                 }
 171
 172                 /* Pack publication into message: */
 173                 publ_to_item(item, publ);
 174                 item++;
 175                 msg_rem -= ITEM_SIZE;
 176
 177                 /* Append full buffer to list: */
 178                 if (!msg_rem) {
 179                         __skb_queue_tail(list, skb);
 180                         skb = NULL;
 181                         msg_rem = msg_dsz;
 182                 }
 183         }
 184         if (skb) {
 185                 hdr = buf_msg(skb);
 186                 msg_set_size(hdr, INT_H_SIZE + (msg_dsz - msg_rem));
 187                 skb_trim(skb, INT_H_SIZE + (msg_dsz - msg_rem));
 188                 __skb_queue_tail(list, skb);
 189         }
 190         hdr = buf_msg(skb_peek_tail(list));
 191         msg_set_last_bulk(hdr);
 192         msg_set_named_seqno(hdr, seqno);
 193 }
 194
 195 /**
 196  * tipc_named_node_up - tell specified node about all publications by this node
 197  */
 198 void tipc_named_node_up(struct net *net, u32 dnode, u16 capabilities)
 199 {
 200         struct name_table *nt = tipc_name_table(net);
 201         struct tipc_net *tn = tipc_net(net);
 202         struct sk_buff_head head;
 203         u16 seqno;
 204
 205         __skb_queue_head_init(&head);
 206         spin_lock_bh(&tn->nametbl_lock);
 207         if (!(capabilities & TIPC_NAMED_BCAST))
 208                 nt->rc_dests++;
 209         seqno = nt->snd_nxt;
 210         spin_unlock_bh(&tn->nametbl_lock);
 211
 212         read_lock_bh(&nt->cluster_scope_lock);
 213         named_distribute(net, &head, dnode, &nt->cluster_scope, seqno);
 214         tipc_node_xmit(net, &head, dnode, 0);
 215         read_unlock_bh(&nt->cluster_scope_lock);
 216 }
 217
 218 /**
 219  * tipc_publ_purge - remove publication associated with a failed node
 220  *
 221  * Invoked for each publication issued by a newly failed node.
 222  * Removes publication structure from name table & deletes it.
 223  */
 224 static void tipc_publ_purge(struct net *net, struct publication *publ, u32 addr)
 225 {
 226         struct tipc_net *tn = tipc_net(net);
 227         struct publication *p;
 228
 229         spin_lock_bh(&tn->nametbl_lock);
 230         p = tipc_nametbl_remove_publ(net, publ->type, publ->lower, publ->upper,
 231                                      publ->node, publ->key);
 232         if (p)
 233                 tipc_node_unsubscribe(net, &p->binding_node, addr);
 234         spin_unlock_bh(&tn->nametbl_lock);
 235
 236         if (p != publ) {
 237                 pr_err("Unable to remove publication from failed node\n"
 238                        " (type=%u, lower=%u, node=0x%x, port=%u, key=%u)\n",
 239                        publ->type, publ->lower, publ->node, publ->port,
 240                        publ->key);
 241         }
 242
 243         if (p)
 244                 kfree_rcu(p, rcu);
 245 }
 246
 247 /**
 248  * tipc_dist_queue_purge - remove deferred updates from a node that went down
 249  */
 250 static void tipc_dist_queue_purge(struct net *net, u32 addr)
 251 {
 252         struct tipc_net *tn = net_generic(net, tipc_net_id);
 253         struct distr_queue_item *e, *tmp;
 254
 255         spin_lock_bh(&tn->nametbl_lock);
 256         list_for_each_entry_safe(e, tmp, &tn->dist_queue, next) {
 257                 if (e->node != addr)
 258                         continue;
 259                 list_del(&e->next);
 260                 kfree(e);
 261         }
 262         spin_unlock_bh(&tn->nametbl_lock);
 263 }
 264
 265 void tipc_publ_notify(struct net *net, struct list_head *nsub_list,
 266                       u32 addr, u16 capabilities)
 267 {
 268         struct name_table *nt = tipc_name_table(net);
 269         struct tipc_net *tn = tipc_net(net);
 270
 271         struct publication *publ, *tmp;
 272
 273         list_for_each_entry_safe(publ, tmp, nsub_list, binding_node)
 274                 tipc_publ_purge(net, publ, addr);
 275         tipc_dist_queue_purge(net, addr);
 276         spin_lock_bh(&tn->nametbl_lock);
 277         if (!(capabilities & TIPC_NAMED_BCAST))
 278                 nt->rc_dests--;
 279         spin_unlock_bh(&tn->nametbl_lock);
 280 }
 281
 282 /**
 283  * tipc_update_nametbl - try to process a nametable update and notify
 284  *                       subscribers
 285  *
 286  * tipc_nametbl_lock must be held.
 287  * Returns the publication item if successful, otherwise NULL.
 288  */
 289 static bool tipc_update_nametbl(struct net *net, struct distr_item *i,
 290                                 u32 node, u32 dtype)
 291 {
 292         struct publication *p = NULL;
 293         u32 lower = ntohl(i->lower);
 294         u32 upper = ntohl(i->upper);
 295         u32 type = ntohl(i->type);
 296         u32 port = ntohl(i->port);
 297         u32 key = ntohl(i->key);
 298
 299         if (dtype == PUBLICATION) {
 300                 p = tipc_nametbl_insert_publ(net, type, lower, upper,
 301                                              TIPC_CLUSTER_SCOPE, node,
 302                                              port, key);
 303                 if (p) {
 304                         tipc_node_subscribe(net, &p->binding_node, node);
 305                         return true;
 306                 }
 307         } else if (dtype == WITHDRAWAL) {
 308                 p = tipc_nametbl_remove_publ(net, type, lower,
 309                                              upper, node, key);
 310                 if (p) {
 311                         tipc_node_unsubscribe(net, &p->binding_node, node);
 312                         kfree_rcu(p, rcu);
 313                         return true;
 314                 }
 315                 pr_warn_ratelimited("Failed to remove binding %u,%u from %x\n",
 316                                     type, lower, node);
 317         } else {
 318                 pr_warn("Unrecognized name table message received\n");
 319         }
 320         return false;
 321 }
 322
 323 static struct sk_buff *tipc_named_dequeue(struct sk_buff_head *namedq,
 324                                           u16 *rcv_nxt, bool *open)
 325 {
 326         struct sk_buff *skb, *tmp;
 327         struct tipc_msg *hdr;
 328         u16 seqno;
 329
 330         spin_lock_bh(&namedq->lock);
 331         skb_queue_walk_safe(namedq, skb, tmp) {
 332                 if (unlikely(skb_linearize(skb))) {
 333                         __skb_unlink(skb, namedq);
 334                         kfree_skb(skb);
 335                         continue;
 336                 }
 337                 hdr = buf_msg(skb);
 338                 seqno = msg_named_seqno(hdr);
 339                 if (msg_is_last_bulk(hdr)) {
 340                         *rcv_nxt = seqno;
 341                         *open = true;
 342                 }
 343
 344                 if (msg_is_bulk(hdr) || msg_is_legacy(hdr)) {
 345                         __skb_unlink(skb, namedq);
 346                         spin_unlock_bh(&namedq->lock);
 347                         return skb;
 348                 }
 349
 350                 if (*open && (*rcv_nxt == seqno)) {
 351                         (*rcv_nxt)++;
 352                         __skb_unlink(skb, namedq);
 353                         spin_unlock_bh(&namedq->lock);
 354                         return skb;
 355                 }
 356
 357                 if (less(seqno, *rcv_nxt)) {
 358                         __skb_unlink(skb, namedq);
 359                         kfree_skb(skb);
 360                         continue;
 361                 }
 362         }
 363         spin_unlock_bh(&namedq->lock);
 364         return NULL;
 365 }
 366
 367 /**
 368  * tipc_named_rcv - process name table update messages sent by another node
 369  */
 370 void tipc_named_rcv(struct net *net, struct sk_buff_head *namedq,
 371                     u16 *rcv_nxt, bool *open)
 372 {
 373         struct tipc_net *tn = tipc_net(net);
 374         struct distr_item *item;
 375         struct tipc_msg *hdr;
 376         struct sk_buff *skb;
 377         u32 count, node;
 378
 379         spin_lock_bh(&tn->nametbl_lock);
 380         while ((skb = tipc_named_dequeue(namedq, rcv_nxt, open))) {
 381                 hdr = buf_msg(skb);
 382                 node = msg_orignode(hdr);
 383                 item = (struct distr_item *)msg_data(hdr);
 384                 count = msg_data_sz(hdr) / ITEM_SIZE;
 385                 while (count--) {
 386                         tipc_update_nametbl(net, item, node, msg_type(hdr));
 387                         item++;
 388                 }
 389                 kfree_skb(skb);
 390         }
 391         spin_unlock_bh(&tn->nametbl_lock);
 392 }
 393
 394 /**
 395  * tipc_named_reinit - re-initialize local publications
 396  *
 397  * This routine is called whenever TIPC networking is enabled.
 398  * All name table entries published by this node are updated to reflect
 399  * the node's new network address.
 400  */
 401 void tipc_named_reinit(struct net *net)
 402 {
 403         struct name_table *nt = tipc_name_table(net);
 404         struct tipc_net *tn = tipc_net(net);
 405         struct publication *publ;
 406         u32 self = tipc_own_addr(net);
 407
 408         spin_lock_bh(&tn->nametbl_lock);
 409
 410         list_for_each_entry_rcu(publ, &nt->node_scope, binding_node)
 411                 publ->node = self;
 412         list_for_each_entry_rcu(publ, &nt->cluster_scope, binding_node)
 413                 publ->node = self;
 414         nt->rc_dests = 0;
 415         spin_unlock_bh(&tn->nametbl_lock);
 416 }