release/src-rt-6.x.4708/linux/linux-2.6.36/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 "cluster.h"
  39 #include "dbg.h"
  40 #include "link.h"
  41 #include "msg.h"
  42 #include "name_distr.h"
  43
  44 #define ITEM_SIZE sizeof(struct distr_item)
  45
  46 /**
  47  * struct distr_item - publication info distributed to other nodes
  48  * @type: name sequence type
  49  * @lower: name sequence lower bound
  50  * @upper: name sequence upper bound
  51  * @ref: publishing port reference
  52  * @key: publication key
  53  *
  54  * ===> All fields are stored in network byte order. <===
  55  *
  56  * First 3 fields identify (name or) name sequence being published.
  57  * Reference field uniquely identifies port that published name sequence.
  58  * Key field uniquely identifies publication, in the event a port has
  59  * multiple publications of the same name sequence.
  60  *
  61  * Note: There is no field that identifies the publishing node because it is
  62  * the same for all items contained within a publication message.
  63  */
  64
  65 struct distr_item {
  66         __be32 type;
  67         __be32 lower;
  68         __be32 upper;
  69         __be32 ref;
  70         __be32 key;
  71 };
  72
  73 /**
  74  * List of externally visible publications by this node --
  75  * that is, all publications having scope > TIPC_NODE_SCOPE.
  76  */
  77
  78 static LIST_HEAD(publ_root);
  79 static u32 publ_cnt = 0;
  80
  81 /**
  82  * publ_to_item - add publication info to a publication message
  83  */
  84
  85 static void publ_to_item(struct distr_item *i, struct publication *p)
  86 {
  87         i->type = htonl(p->type);
  88         i->lower = htonl(p->lower);
  89         i->upper = htonl(p->upper);
  90         i->ref = htonl(p->ref);
  91         i->key = htonl(p->key);
  92         dbg("publ_to_item: %u, %u, %u\n", p->type, p->lower, p->upper);
  93 }
  94
  95 /**
  96  * named_prepare_buf - allocate & initialize a publication message
  97  */
  98
  99 static struct sk_buff *named_prepare_buf(u32 type, u32 size, u32 dest)
 100 {
 101         struct sk_buff *buf = buf_acquire(LONG_H_SIZE + size);
 102         struct tipc_msg *msg;
 103
 104         if (buf != NULL) {
 105                 msg = buf_msg(buf);
 106                 tipc_msg_init(msg, NAME_DISTRIBUTOR, type, LONG_H_SIZE, dest);
 107                 msg_set_size(msg, LONG_H_SIZE + size);
 108         }
 109         return buf;
 110 }
 111
 112 /**
 113  * tipc_named_publish - tell other nodes about a new publication by this node
 114  */
 115
 116 void tipc_named_publish(struct publication *publ)
 117 {
 118         struct sk_buff *buf;
 119         struct distr_item *item;
 120
 121         list_add_tail(&publ->local_list, &publ_root);
 122         publ_cnt++;
 123
 124         buf = named_prepare_buf(PUBLICATION, ITEM_SIZE, 0);
 125         if (!buf) {
 126                 warn("Publication distribution failure\n");
 127                 return;
 128         }
 129
 130         item = (struct distr_item *)msg_data(buf_msg(buf));
 131         publ_to_item(item, publ);
 132         dbg("tipc_named_withdraw: broadcasting publish msg\n");
 133         tipc_cltr_broadcast(buf);
 134 }
 135
 136 /**
 137  * tipc_named_withdraw - tell other nodes about a withdrawn publication by this node
 138  */
 139
 140 void tipc_named_withdraw(struct publication *publ)
 141 {
 142         struct sk_buff *buf;
 143         struct distr_item *item;
 144
 145         list_del(&publ->local_list);
 146         publ_cnt--;
 147
 148         buf = named_prepare_buf(WITHDRAWAL, ITEM_SIZE, 0);
 149         if (!buf) {
 150                 warn("Withdrawl distribution failure\n");
 151                 return;
 152         }
 153
 154         item = (struct distr_item *)msg_data(buf_msg(buf));
 155         publ_to_item(item, publ);
 156         dbg("tipc_named_withdraw: broadcasting withdraw msg\n");
 157         tipc_cltr_broadcast(buf);
 158 }
 159
 160 /**
 161  * tipc_named_node_up - tell specified node about all publications by this node
 162  */
 163
 164 void tipc_named_node_up(unsigned long node)
 165 {
 166         struct publication *publ;
 167         struct distr_item *item = NULL;
 168         struct sk_buff *buf = NULL;
 169         u32 left = 0;
 170         u32 rest;
 171         u32 max_item_buf;
 172
 173         read_lock_bh(&tipc_nametbl_lock);
 174         max_item_buf = TIPC_MAX_USER_MSG_SIZE / ITEM_SIZE;
 175         max_item_buf *= ITEM_SIZE;
 176         rest = publ_cnt * ITEM_SIZE;
 177
 178         list_for_each_entry(publ, &publ_root, local_list) {
 179                 if (!buf) {
 180                         left = (rest <= max_item_buf) ? rest : max_item_buf;
 181                         rest -= left;
 182                         buf = named_prepare_buf(PUBLICATION, left, node);
 183                         if (!buf) {
 184                                 warn("Bulk publication distribution failure\n");
 185                                 goto exit;
 186                         }
 187                         item = (struct distr_item *)msg_data(buf_msg(buf));
 188                 }
 189                 publ_to_item(item, publ);
 190                 item++;
 191                 left -= ITEM_SIZE;
 192                 if (!left) {
 193                         msg_set_link_selector(buf_msg(buf), node);
 194                         dbg("tipc_named_node_up: sending publish msg to "
 195                             "<%u.%u.%u>\n", tipc_zone(node),
 196                             tipc_cluster(node), tipc_node(node));
 197                         tipc_link_send(buf, node, node);
 198                         buf = NULL;
 199                 }
 200         }
 201 exit:
 202         read_unlock_bh(&tipc_nametbl_lock);
 203 }
 204
 205 /**
 206  * node_is_down - remove publication associated with a failed node
 207  *
 208  * Invoked for each publication issued by a newly failed node.
 209  * Removes publication structure from name table & deletes it.
 210  * In rare cases the link may have come back up again when this
 211  * function is called, and we have two items representing the same
 212  * publication. Nudge this item's key to distinguish it from the other.
 213  * (Note: Publication's node subscription is already unsubscribed.)
 214  */
 215
 216 static void node_is_down(struct publication *publ)
 217 {
 218         struct publication *p;
 219
 220         write_lock_bh(&tipc_nametbl_lock);
 221         dbg("node_is_down: withdrawing %u, %u, %u\n",
 222             publ->type, publ->lower, publ->upper);
 223         publ->key += 1222345;
 224         p = tipc_nametbl_remove_publ(publ->type, publ->lower,
 225                                      publ->node, publ->ref, publ->key);
 226         write_unlock_bh(&tipc_nametbl_lock);
 227
 228         if (p != publ) {
 229                 err("Unable to remove publication from failed node\n"
 230                     "(type=%u, lower=%u, node=0x%x, ref=%u, key=%u)\n",
 231                     publ->type, publ->lower, publ->node, publ->ref, publ->key);
 232         }
 233
 234         if (p) {
 235                 kfree(p);
 236         }
 237 }
 238
 239 /**
 240  * tipc_named_recv - process name table update message sent by another node
 241  */
 242
 243 void tipc_named_recv(struct sk_buff *buf)
 244 {
 245         struct publication *publ;
 246         struct tipc_msg *msg = buf_msg(buf);
 247         struct distr_item *item = (struct distr_item *)msg_data(msg);
 248         u32 count = msg_data_sz(msg) / ITEM_SIZE;
 249
 250         write_lock_bh(&tipc_nametbl_lock);
 251         while (count--) {
 252                 if (msg_type(msg) == PUBLICATION) {
 253                         dbg("tipc_named_recv: got publication for %u, %u, %u\n",
 254                             ntohl(item->type), ntohl(item->lower),
 255                             ntohl(item->upper));
 256                         publ = tipc_nametbl_insert_publ(ntohl(item->type),
 257                                                         ntohl(item->lower),
 258                                                         ntohl(item->upper),
 259                                                         TIPC_CLUSTER_SCOPE,
 260                                                         msg_orignode(msg),
 261                                                         ntohl(item->ref),
 262                                                         ntohl(item->key));
 263                         if (publ) {
 264                                 tipc_nodesub_subscribe(&publ->subscr,
 265                                                        msg_orignode(msg),
 266                                                        publ,
 267                                                        (net_ev_handler)node_is_down);
 268                         }
 269                 } else if (msg_type(msg) == WITHDRAWAL) {
 270                         dbg("tipc_named_recv: got withdrawl for %u, %u, %u\n",
 271                             ntohl(item->type), ntohl(item->lower),
 272                             ntohl(item->upper));
 273                         publ = tipc_nametbl_remove_publ(ntohl(item->type),
 274                                                         ntohl(item->lower),
 275                                                         msg_orignode(msg),
 276                                                         ntohl(item->ref),
 277                                                         ntohl(item->key));
 278
 279                         if (publ) {
 280                                 tipc_nodesub_unsubscribe(&publ->subscr);
 281                                 kfree(publ);
 282                         } else {
 283                                 err("Unable to remove publication by node 0x%x\n"
 284                                     "(type=%u, lower=%u, ref=%u, key=%u)\n",
 285                                     msg_orignode(msg),
 286                                     ntohl(item->type), ntohl(item->lower),
 287                                     ntohl(item->ref), ntohl(item->key));
 288                         }
 289                 } else {
 290                         warn("Unrecognized name table message received\n");
 291                 }
 292                 item++;
 293         }
 294         write_unlock_bh(&tipc_nametbl_lock);
 295         buf_discard(buf);
 296 }
 297
 298 /**
 299  * tipc_named_reinit - re-initialize local publication list
 300  *
 301  * This routine is called whenever TIPC networking is (re)enabled.
 302  * All existing publications by this node that have "cluster" or "zone" scope
 303  * are updated to reflect the node's current network address.
 304  * (If the node's address is unchanged, the update loop terminates immediately.)
 305  */
 306
 307 void tipc_named_reinit(void)
 308 {
 309         struct publication *publ;
 310
 311         write_lock_bh(&tipc_nametbl_lock);
 312         list_for_each_entry(publ, &publ_root, local_list) {
 313                 if (publ->node == tipc_own_addr)
 314                         break;
 315                 publ->node = tipc_own_addr;
 316         }
 317         write_unlock_bh(&tipc_nametbl_lock);
 318 }