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, 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
  62 struct distr_item {
  63         __be32 type;
  64         __be32 lower;
  65         __be32 upper;
  66         __be32 ref;
  67         __be32 key;
  68 };
  69
  70 /**
  71  * List of externally visible publications by this node --
  72  * that is, all publications having scope > TIPC_NODE_SCOPE.
  73  */
  74
  75 static LIST_HEAD(publ_root);
  76 static u32 publ_cnt;
  77
  78 /**
  79  * publ_to_item - add publication info to a publication message
  80  */
  81
  82 static void publ_to_item(struct distr_item *i, struct publication *p)
  83 {
  84         i->type = htonl(p->type);
  85         i->lower = htonl(p->lower);
  86         i->upper = htonl(p->upper);
  87         i->ref = htonl(p->ref);
  88         i->key = htonl(p->key);
  89 }
  90
  91 /**
  92  * named_prepare_buf - allocate & initialize a publication message
  93  */
  94
  95 static struct sk_buff *named_prepare_buf(u32 type, u32 size, u32 dest)
  96 {
  97         struct sk_buff *buf = tipc_buf_acquire(LONG_H_SIZE + size);
  98         struct tipc_msg *msg;
  99
 100         if (buf != NULL) {
 101                 msg = buf_msg(buf);
 102                 tipc_msg_init(msg, NAME_DISTRIBUTOR, type, LONG_H_SIZE, dest);
 103                 msg_set_size(msg, LONG_H_SIZE + size);
 104         }
 105         return buf;
 106 }
 107
 108 static void named_cluster_distribute(struct sk_buff *buf)
 109 {
 110         struct sk_buff *buf_copy;
 111         struct tipc_node *n_ptr;
 112         u32 n_num;
 113
 114         for (n_num = 1; n_num <= tipc_net.highest_node; n_num++) {
 115                 n_ptr = tipc_net.nodes[n_num];
 116                 if (n_ptr && tipc_node_has_active_links(n_ptr)) {
 117                         buf_copy = skb_copy(buf, GFP_ATOMIC);
 118                         if (!buf_copy)
 119                                 break;
 120                         msg_set_destnode(buf_msg(buf_copy), n_ptr->addr);
 121                         tipc_link_send(buf_copy, n_ptr->addr, n_ptr->addr);
 122                 }
 123         }
 124
 125         buf_discard(buf);
 126 }
 127
 128 /**
 129  * tipc_named_publish - tell other nodes about a new publication by this node
 130  */
 131
 132 void tipc_named_publish(struct publication *publ)
 133 {
 134         struct sk_buff *buf;
 135         struct distr_item *item;
 136
 137         list_add_tail(&publ->local_list, &publ_root);
 138         publ_cnt++;
 139
 140         buf = named_prepare_buf(PUBLICATION, ITEM_SIZE, 0);
 141         if (!buf) {
 142                 warn("Publication distribution failure\n");
 143                 return;
 144         }
 145
 146         item = (struct distr_item *)msg_data(buf_msg(buf));
 147         publ_to_item(item, publ);
 148         named_cluster_distribute(buf);
 149 }
 150
 151 /**
 152  * tipc_named_withdraw - tell other nodes about a withdrawn publication by this node
 153  */
 154
 155 void tipc_named_withdraw(struct publication *publ)
 156 {
 157         struct sk_buff *buf;
 158         struct distr_item *item;
 159
 160         list_del(&publ->local_list);
 161         publ_cnt--;
 162
 163         buf = named_prepare_buf(WITHDRAWAL, ITEM_SIZE, 0);
 164         if (!buf) {
 165                 warn("Withdrawl distribution failure\n");
 166                 return;
 167         }
 168
 169         item = (struct distr_item *)msg_data(buf_msg(buf));
 170         publ_to_item(item, publ);
 171         named_cluster_distribute(buf);
 172 }
 173
 174 /**
 175  * tipc_named_node_up - tell specified node about all publications by this node
 176  */
 177
 178 void tipc_named_node_up(unsigned long node)
 179 {
 180         struct publication *publ;
 181         struct distr_item *item = NULL;
 182         struct sk_buff *buf = NULL;
 183         u32 left = 0;
 184         u32 rest;
 185         u32 max_item_buf;
 186
 187         read_lock_bh(&tipc_nametbl_lock);
 188         max_item_buf = TIPC_MAX_USER_MSG_SIZE / ITEM_SIZE;
 189         max_item_buf *= ITEM_SIZE;
 190         rest = publ_cnt * ITEM_SIZE;
 191
 192         list_for_each_entry(publ, &publ_root, local_list) {
 193                 if (!buf) {
 194                         left = (rest <= max_item_buf) ? rest : max_item_buf;
 195                         rest -= left;
 196                         buf = named_prepare_buf(PUBLICATION, left, node);
 197                         if (!buf) {
 198                                 warn("Bulk publication distribution failure\n");
 199                                 goto exit;
 200                         }
 201                         item = (struct distr_item *)msg_data(buf_msg(buf));
 202                 }
 203                 publ_to_item(item, publ);
 204                 item++;
 205                 left -= ITEM_SIZE;
 206                 if (!left) {
 207                         msg_set_link_selector(buf_msg(buf), node);
 208                         tipc_link_send(buf, node, node);
 209                         buf = NULL;
 210                 }
 211         }
 212 exit:
 213         read_unlock_bh(&tipc_nametbl_lock);
 214 }
 215
 216 /**
 217  * node_is_down - remove publication associated with a failed node
 218  *
 219  * Invoked for each publication issued by a newly failed node.
 220  * Removes publication structure from name table & deletes it.
 221  * In rare cases the link may have come back up again when this
 222  * function is called, and we have two items representing the same
 223  * publication. Nudge this item's key to distinguish it from the other.
 224  * (Note: Publication's node subscription is already unsubscribed.)
 225  */
 226
 227 static void node_is_down(struct publication *publ)
 228 {
 229         struct publication *p;
 230
 231         write_lock_bh(&tipc_nametbl_lock);
 232         publ->key += 1222345;
 233         p = tipc_nametbl_remove_publ(publ->type, publ->lower,
 234                                      publ->node, publ->ref, publ->key);
 235         write_unlock_bh(&tipc_nametbl_lock);
 236
 237         if (p != publ) {
 238                 err("Unable to remove publication from failed node\n"
 239                     "(type=%u, lower=%u, node=0x%x, ref=%u, key=%u)\n",
 240                     publ->type, publ->lower, publ->node, publ->ref, publ->key);
 241         }
 242
 243         kfree(p);
 244 }
 245
 246 /**
 247  * tipc_named_recv - process name table update message sent by another node
 248  */
 249
 250 void tipc_named_recv(struct sk_buff *buf)
 251 {
 252         struct publication *publ;
 253         struct tipc_msg *msg = buf_msg(buf);
 254         struct distr_item *item = (struct distr_item *)msg_data(msg);
 255         u32 count = msg_data_sz(msg) / ITEM_SIZE;
 256
 257         write_lock_bh(&tipc_nametbl_lock);
 258         while (count--) {
 259                 if (msg_type(msg) == PUBLICATION) {
 260                         publ = tipc_nametbl_insert_publ(ntohl(item->type),
 261                                                         ntohl(item->lower),
 262                                                         ntohl(item->upper),
 263                                                         TIPC_CLUSTER_SCOPE,
 264                                                         msg_orignode(msg),
 265                                                         ntohl(item->ref),
 266                                                         ntohl(item->key));
 267                         if (publ) {
 268                                 tipc_nodesub_subscribe(&publ->subscr,
 269                                                        msg_orignode(msg),
 270                                                        publ,
 271                                                        (net_ev_handler)node_is_down);
 272                         }
 273                 } else if (msg_type(msg) == WITHDRAWAL) {
 274                         publ = tipc_nametbl_remove_publ(ntohl(item->type),
 275                                                         ntohl(item->lower),
 276                                                         msg_orignode(msg),
 277                                                         ntohl(item->ref),
 278                                                         ntohl(item->key));
 279
 280                         if (publ) {
 281                                 tipc_nodesub_unsubscribe(&publ->subscr);
 282                                 kfree(publ);
 283                         } else {
 284                                 err("Unable to remove publication by node 0x%x\n"
 285                                     "(type=%u, lower=%u, ref=%u, key=%u)\n",
 286                                     msg_orignode(msg),
 287                                     ntohl(item->type), ntohl(item->lower),
 288                                     ntohl(item->ref), ntohl(item->key));
 289                         }
 290                 } else {
 291                         warn("Unrecognized name table message received\n");
 292                 }
 293                 item++;
 294         }
 295         write_unlock_bh(&tipc_nametbl_lock);
 296         buf_discard(buf);
 297 }
 298
 299 /**
 300  * tipc_named_reinit - re-initialize local publication list
 301  *
 302  * This routine is called whenever TIPC networking is (re)enabled.
 303  * All existing publications by this node that have "cluster" or "zone" scope
 304  * are updated to reflect the node's current network address.
 305  * (If the node's address is unchanged, the update loop terminates immediately.)
 306  */
 307
 308 void tipc_named_reinit(void)
 309 {
 310         struct publication *publ;
 311
 312         write_lock_bh(&tipc_nametbl_lock);
 313         list_for_each_entry(publ, &publ_root, local_list) {
 314                 if (publ->node == tipc_own_addr)
 315                         break;
 316                 publ->node = tipc_own_addr;
 317         }
 318         write_unlock_bh(&tipc_nametbl_lock);
 319 }