net/tipc/name_distr.c

   1 /*
   2  * net/tipc/name_distr.c: TIPC name distribution code
   3  *
   4  * Copyright (c) 2000-2006, 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 #define ITEM_SIZE sizeof(struct distr_item)
  42
  43 /**
  44  * struct distr_item - publication info distributed to other nodes
  45  * @type: name sequence type
  46  * @lower: name sequence lower bound
  47  * @upper: name sequence upper bound
  48  * @ref: publishing port reference
  49  * @key: publication key
  50  *
  51  * ===> All fields are stored in network byte order. <===
  52  *
  53  * First 3 fields identify (name or) name sequence being published.
  54  * Reference field uniquely identifies port that published name sequence.
  55  * Key field uniquely identifies publication, in the event a port has
  56  * multiple publications of the same name sequence.
  57  *
  58  * Note: There is no field that identifies the publishing node because it is
  59  * the same for all items contained within a publication message.
  60  */
  61 struct distr_item {
  62         __be32 type;
  63         __be32 lower;
  64         __be32 upper;
  65         __be32 ref;
  66         __be32 key;
  67 };
  68
  69 /**
  70  * struct publ_list - list of publications made by this node
  71  * @list: circular list of publications
  72  * @list_size: number of entries in list
  73  */
  74 struct publ_list {
  75         struct list_head list;
  76         u32 size;
  77 };
  78
  79 static struct publ_list publ_zone = {
  80         .list = LIST_HEAD_INIT(publ_zone.list),
  81         .size = 0,
  82 };
  83
  84 static struct publ_list publ_cluster = {
  85         .list = LIST_HEAD_INIT(publ_cluster.list),
  86         .size = 0,
  87 };
  88
  89 static struct publ_list publ_node = {
  90         .list = LIST_HEAD_INIT(publ_node.list),
  91         .size = 0,
  92 };
  93
  94 static struct publ_list *publ_lists[] = {
  95         NULL,
  96         &publ_zone,     /* publ_lists[TIPC_ZONE_SCOPE]          */
  97         &publ_cluster,  /* publ_lists[TIPC_CLUSTER_SCOPE]       */
  98         &publ_node      /* publ_lists[TIPC_NODE_SCOPE]          */
  99 };
 100
 101
 102 /**
 103  * publ_to_item - add publication info to a publication message
 104  */
 105 static void publ_to_item(struct distr_item *i, struct publication *p)
 106 {
 107         i->type = htonl(p->type);
 108         i->lower = htonl(p->lower);
 109         i->upper = htonl(p->upper);
 110         i->ref = htonl(p->ref);
 111         i->key = htonl(p->key);
 112 }
 113
 114 /**
 115  * named_prepare_buf - allocate & initialize a publication message
 116  */
 117 static struct sk_buff *named_prepare_buf(u32 type, u32 size, u32 dest)
 118 {
 119         struct sk_buff *buf = tipc_buf_acquire(INT_H_SIZE + size);
 120         struct tipc_msg *msg;
 121
 122         if (buf != NULL) {
 123                 msg = buf_msg(buf);
 124                 tipc_msg_init(msg, NAME_DISTRIBUTOR, type, INT_H_SIZE, dest);
 125                 msg_set_size(msg, INT_H_SIZE + size);
 126         }
 127         return buf;
 128 }
 129
 130 static void named_cluster_distribute(struct sk_buff *buf)
 131 {
 132         struct sk_buff *buf_copy;
 133         struct tipc_node *n_ptr;
 134         struct tipc_link *l_ptr;
 135
 136         rcu_read_lock();
 137         list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
 138                 spin_lock_bh(&n_ptr->lock);
 139                 l_ptr = n_ptr->active_links[n_ptr->addr & 1];
 140                 if (l_ptr) {
 141                         buf_copy = skb_copy(buf, GFP_ATOMIC);
 142                         if (!buf_copy) {
 143                                 spin_unlock_bh(&n_ptr->lock);
 144                                 break;
 145                         }
 146                         msg_set_destnode(buf_msg(buf_copy), n_ptr->addr);
 147                         __tipc_link_xmit(l_ptr, buf_copy);
 148                 }
 149                 spin_unlock_bh(&n_ptr->lock);
 150         }
 151         rcu_read_unlock();
 152
 153         kfree_skb(buf);
 154 }
 155
 156 /**
 157  * tipc_named_publish - tell other nodes about a new publication by this node
 158  */
 159 void tipc_named_publish(struct publication *publ)
 160 {
 161         struct sk_buff *buf;
 162         struct distr_item *item;
 163
 164         list_add_tail(&publ->local_list, &publ_lists[publ->scope]->list);
 165         publ_lists[publ->scope]->size++;
 166
 167         if (publ->scope == TIPC_NODE_SCOPE)
 168                 return;
 169
 170         buf = named_prepare_buf(PUBLICATION, ITEM_SIZE, 0);
 171         if (!buf) {
 172                 pr_warn("Publication distribution failure\n");
 173                 return;
 174         }
 175
 176         item = (struct distr_item *)msg_data(buf_msg(buf));
 177         publ_to_item(item, publ);
 178         named_cluster_distribute(buf);
 179 }
 180
 181 /**
 182  * tipc_named_withdraw - tell other nodes about a withdrawn publication by this node
 183  */
 184 void tipc_named_withdraw(struct publication *publ)
 185 {
 186         struct sk_buff *buf;
 187         struct distr_item *item;
 188
 189         list_del(&publ->local_list);
 190         publ_lists[publ->scope]->size--;
 191
 192         if (publ->scope == TIPC_NODE_SCOPE)
 193                 return;
 194
 195         buf = named_prepare_buf(WITHDRAWAL, ITEM_SIZE, 0);
 196         if (!buf) {
 197                 pr_warn("Withdrawal distribution failure\n");
 198                 return;
 199         }
 200
 201         item = (struct distr_item *)msg_data(buf_msg(buf));
 202         publ_to_item(item, publ);
 203         named_cluster_distribute(buf);
 204 }
 205
 206 /*
 207  * named_distribute - prepare name info for bulk distribution to another node
 208  */
 209 static void named_distribute(struct list_head *message_list, u32 node,
 210                              struct publ_list *pls, u32 max_item_buf)
 211 {
 212         struct publication *publ;
 213         struct sk_buff *buf = NULL;
 214         struct distr_item *item = NULL;
 215         u32 left = 0;
 216         u32 rest = pls->size * ITEM_SIZE;
 217
 218         list_for_each_entry(publ, &pls->list, local_list) {
 219                 if (!buf) {
 220                         left = (rest <= max_item_buf) ? rest : max_item_buf;
 221                         rest -= left;
 222                         buf = named_prepare_buf(PUBLICATION, left, node);
 223                         if (!buf) {
 224                                 pr_warn("Bulk publication failure\n");
 225                                 return;
 226                         }
 227                         item = (struct distr_item *)msg_data(buf_msg(buf));
 228                 }
 229                 publ_to_item(item, publ);
 230                 item++;
 231                 left -= ITEM_SIZE;
 232                 if (!left) {
 233                         list_add_tail((struct list_head *)buf, message_list);
 234                         buf = NULL;
 235                 }
 236         }
 237 }
 238
 239 /**
 240  * tipc_named_node_up - tell specified node about all publications by this node
 241  */
 242 void tipc_named_node_up(unsigned long nodearg)
 243 {
 244         struct tipc_node *n_ptr;
 245         struct tipc_link *l_ptr;
 246         struct list_head message_list;
 247         u32 node = (u32)nodearg;
 248         u32 max_item_buf = 0;
 249
 250         /* compute maximum amount of publication data to send per message */
 251         read_lock_bh(&tipc_net_lock);
 252         n_ptr = tipc_node_find(node);
 253         if (n_ptr) {
 254                 tipc_node_lock(n_ptr);
 255                 l_ptr = n_ptr->active_links[0];
 256                 if (l_ptr)
 257                         max_item_buf = ((l_ptr->max_pkt - INT_H_SIZE) /
 258                                 ITEM_SIZE) * ITEM_SIZE;
 259                 tipc_node_unlock(n_ptr);
 260         }
 261         read_unlock_bh(&tipc_net_lock);
 262         if (!max_item_buf)
 263                 return;
 264
 265         /* create list of publication messages, then send them as a unit */
 266         INIT_LIST_HEAD(&message_list);
 267
 268         read_lock_bh(&tipc_nametbl_lock);
 269         named_distribute(&message_list, node, &publ_cluster, max_item_buf);
 270         named_distribute(&message_list, node, &publ_zone, max_item_buf);
 271         read_unlock_bh(&tipc_nametbl_lock);
 272
 273         tipc_link_names_xmit(&message_list, node);
 274 }
 275
 276 /**
 277  * named_purge_publ - remove publication associated with a failed node
 278  *
 279  * Invoked for each publication issued by a newly failed node.
 280  * Removes publication structure from name table & deletes it.
 281  */
 282 static void named_purge_publ(struct publication *publ)
 283 {
 284         struct publication *p;
 285
 286         write_lock_bh(&tipc_nametbl_lock);
 287         p = tipc_nametbl_remove_publ(publ->type, publ->lower,
 288                                      publ->node, publ->ref, publ->key);
 289         if (p)
 290                 tipc_nodesub_unsubscribe(&p->subscr);
 291         write_unlock_bh(&tipc_nametbl_lock);
 292
 293         if (p != publ) {
 294                 pr_err("Unable to remove publication from failed node\n"
 295                        " (type=%u, lower=%u, node=0x%x, ref=%u, key=%u)\n",
 296                        publ->type, publ->lower, publ->node, publ->ref,
 297                        publ->key);
 298         }
 299
 300         kfree(p);
 301 }
 302
 303 /**
 304  * tipc_named_rcv - process name table update message sent by another node
 305  */
 306 void tipc_named_rcv(struct sk_buff *buf)
 307 {
 308         struct publication *publ;
 309         struct tipc_msg *msg = buf_msg(buf);
 310         struct distr_item *item = (struct distr_item *)msg_data(msg);
 311         u32 count = msg_data_sz(msg) / ITEM_SIZE;
 312
 313         write_lock_bh(&tipc_nametbl_lock);
 314         while (count--) {
 315                 if (msg_type(msg) == PUBLICATION) {
 316                         publ = tipc_nametbl_insert_publ(ntohl(item->type),
 317                                                         ntohl(item->lower),
 318                                                         ntohl(item->upper),
 319                                                         TIPC_CLUSTER_SCOPE,
 320                                                         msg_orignode(msg),
 321                                                         ntohl(item->ref),
 322                                                         ntohl(item->key));
 323                         if (publ) {
 324                                 tipc_nodesub_subscribe(&publ->subscr,
 325                                                        msg_orignode(msg),
 326                                                        publ,
 327                                                        (net_ev_handler)
 328                                                        named_purge_publ);
 329                         }
 330                 } else if (msg_type(msg) == WITHDRAWAL) {
 331                         publ = tipc_nametbl_remove_publ(ntohl(item->type),
 332                                                         ntohl(item->lower),
 333                                                         msg_orignode(msg),
 334                                                         ntohl(item->ref),
 335                                                         ntohl(item->key));
 336
 337                         if (publ) {
 338                                 tipc_nodesub_unsubscribe(&publ->subscr);
 339                                 kfree(publ);
 340                         } else {
 341                                 pr_err("Unable to remove publication by node 0x%x\n"
 342                                        " (type=%u, lower=%u, ref=%u, key=%u)\n",
 343                                        msg_orignode(msg), ntohl(item->type),
 344                                        ntohl(item->lower), ntohl(item->ref),
 345                                        ntohl(item->key));
 346                         }
 347                 } else {
 348                         pr_warn("Unrecognized name table message received\n");
 349                 }
 350                 item++;
 351         }
 352         write_unlock_bh(&tipc_nametbl_lock);
 353         kfree_skb(buf);
 354 }
 355
 356 /**
 357  * tipc_named_reinit - re-initialize local publications
 358  *
 359  * This routine is called whenever TIPC networking is enabled.
 360  * All name table entries published by this node are updated to reflect
 361  * the node's new network address.
 362  */
 363 void tipc_named_reinit(void)
 364 {
 365         struct publication *publ;
 366         int scope;
 367
 368         write_lock_bh(&tipc_nametbl_lock);
 369
 370         for (scope = TIPC_ZONE_SCOPE; scope <= TIPC_NODE_SCOPE; scope++)
 371                 list_for_each_entry(publ, &publ_lists[scope]->list, local_list)
 372                         publ->node = tipc_own_addr;
 373
 374         write_unlock_bh(&tipc_nametbl_lock);
 375 }