linux/net/tipc/name_distr.c
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   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
  62struct 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
  75static LIST_HEAD(publ_root);
  76static u32 publ_cnt;
  77
  78/**
  79 * publ_to_item - add publication info to a publication message
  80 */
  81
  82static 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
  95static struct sk_buff *named_prepare_buf(u32 type, u32 size, u32 dest)
  96{
  97        struct sk_buff *buf = tipc_buf_acquire(INT_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, INT_H_SIZE, dest);
 103                msg_set_size(msg, INT_H_SIZE + size);
 104        }
 105        return buf;
 106}
 107
 108static void named_cluster_distribute(struct sk_buff *buf)
 109{
 110        struct sk_buff *buf_copy;
 111        struct tipc_node *n_ptr;
 112
 113        list_for_each_entry(n_ptr, &tipc_node_list, list) {
 114                if (tipc_node_active_links(n_ptr)) {
 115                        buf_copy = skb_copy(buf, GFP_ATOMIC);
 116                        if (!buf_copy)
 117                                break;
 118                        msg_set_destnode(buf_msg(buf_copy), n_ptr->addr);
 119                        tipc_link_send(buf_copy, n_ptr->addr, n_ptr->addr);
 120                }
 121        }
 122
 123        buf_discard(buf);
 124}
 125
 126/**
 127 * tipc_named_publish - tell other nodes about a new publication by this node
 128 */
 129
 130void tipc_named_publish(struct publication *publ)
 131{
 132        struct sk_buff *buf;
 133        struct distr_item *item;
 134
 135        list_add_tail(&publ->local_list, &publ_root);
 136        publ_cnt++;
 137
 138        buf = named_prepare_buf(PUBLICATION, ITEM_SIZE, 0);
 139        if (!buf) {
 140                warn("Publication distribution failure\n");
 141                return;
 142        }
 143
 144        item = (struct distr_item *)msg_data(buf_msg(buf));
 145        publ_to_item(item, publ);
 146        named_cluster_distribute(buf);
 147}
 148
 149/**
 150 * tipc_named_withdraw - tell other nodes about a withdrawn publication by this node
 151 */
 152
 153void tipc_named_withdraw(struct publication *publ)
 154{
 155        struct sk_buff *buf;
 156        struct distr_item *item;
 157
 158        list_del(&publ->local_list);
 159        publ_cnt--;
 160
 161        buf = named_prepare_buf(WITHDRAWAL, ITEM_SIZE, 0);
 162        if (!buf) {
 163                warn("Withdrawal distribution failure\n");
 164                return;
 165        }
 166
 167        item = (struct distr_item *)msg_data(buf_msg(buf));
 168        publ_to_item(item, publ);
 169        named_cluster_distribute(buf);
 170}
 171
 172/**
 173 * tipc_named_node_up - tell specified node about all publications by this node
 174 */
 175
 176void tipc_named_node_up(unsigned long nodearg)
 177{
 178        struct tipc_node *n_ptr;
 179        struct tipc_link *l_ptr;
 180        struct publication *publ;
 181        struct distr_item *item = NULL;
 182        struct sk_buff *buf = NULL;
 183        struct list_head message_list;
 184        u32 node = (u32)nodearg;
 185        u32 left = 0;
 186        u32 rest;
 187        u32 max_item_buf = 0;
 188
 189        /* compute maximum amount of publication data to send per message */
 190
 191        read_lock_bh(&tipc_net_lock);
 192        n_ptr = tipc_node_find(node);
 193        if (n_ptr) {
 194                tipc_node_lock(n_ptr);
 195                l_ptr = n_ptr->active_links[0];
 196                if (l_ptr)
 197                        max_item_buf = ((l_ptr->max_pkt - INT_H_SIZE) /
 198                                ITEM_SIZE) * ITEM_SIZE;
 199                tipc_node_unlock(n_ptr);
 200        }
 201        read_unlock_bh(&tipc_net_lock);
 202        if (!max_item_buf)
 203                return;
 204
 205        /* create list of publication messages, then send them as a unit */
 206
 207        INIT_LIST_HEAD(&message_list);
 208
 209        read_lock_bh(&tipc_nametbl_lock);
 210        rest = publ_cnt * ITEM_SIZE;
 211
 212        list_for_each_entry(publ, &publ_root, local_list) {
 213                if (!buf) {
 214                        left = (rest <= max_item_buf) ? rest : max_item_buf;
 215                        rest -= left;
 216                        buf = named_prepare_buf(PUBLICATION, left, node);
 217                        if (!buf) {
 218                                warn("Bulk publication distribution failure\n");
 219                                goto exit;
 220                        }
 221                        item = (struct distr_item *)msg_data(buf_msg(buf));
 222                }
 223                publ_to_item(item, publ);
 224                item++;
 225                left -= ITEM_SIZE;
 226                if (!left) {
 227                        list_add_tail((struct list_head *)buf, &message_list);
 228                        buf = NULL;
 229                }
 230        }
 231exit:
 232        read_unlock_bh(&tipc_nametbl_lock);
 233
 234        tipc_link_send_names(&message_list, (u32)node);
 235}
 236
 237/**
 238 * named_purge_publ - remove publication associated with a failed node
 239 *
 240 * Invoked for each publication issued by a newly failed node.
 241 * Removes publication structure from name table & deletes it.
 242 * In rare cases the link may have come back up again when this
 243 * function is called, and we have two items representing the same
 244 * publication. Nudge this item's key to distinguish it from the other.
 245 */
 246
 247static void named_purge_publ(struct publication *publ)
 248{
 249        struct publication *p;
 250
 251        write_lock_bh(&tipc_nametbl_lock);
 252        publ->key += 1222345;
 253        p = tipc_nametbl_remove_publ(publ->type, publ->lower,
 254                                     publ->node, publ->ref, publ->key);
 255        if (p)
 256                tipc_nodesub_unsubscribe(&p->subscr);
 257        write_unlock_bh(&tipc_nametbl_lock);
 258
 259        if (p != publ) {
 260                err("Unable to remove publication from failed node\n"
 261                    "(type=%u, lower=%u, node=0x%x, ref=%u, key=%u)\n",
 262                    publ->type, publ->lower, publ->node, publ->ref, publ->key);
 263        }
 264
 265        kfree(p);
 266}
 267
 268/**
 269 * tipc_named_recv - process name table update message sent by another node
 270 */
 271
 272void tipc_named_recv(struct sk_buff *buf)
 273{
 274        struct publication *publ;
 275        struct tipc_msg *msg = buf_msg(buf);
 276        struct distr_item *item = (struct distr_item *)msg_data(msg);
 277        u32 count = msg_data_sz(msg) / ITEM_SIZE;
 278
 279        write_lock_bh(&tipc_nametbl_lock);
 280        while (count--) {
 281                if (msg_type(msg) == PUBLICATION) {
 282                        publ = tipc_nametbl_insert_publ(ntohl(item->type),
 283                                                        ntohl(item->lower),
 284                                                        ntohl(item->upper),
 285                                                        TIPC_CLUSTER_SCOPE,
 286                                                        msg_orignode(msg),
 287                                                        ntohl(item->ref),
 288                                                        ntohl(item->key));
 289                        if (publ) {
 290                                tipc_nodesub_subscribe(&publ->subscr,
 291                                                       msg_orignode(msg),
 292                                                       publ,
 293                                                       (net_ev_handler)
 294                                                       named_purge_publ);
 295                        }
 296                } else if (msg_type(msg) == WITHDRAWAL) {
 297                        publ = tipc_nametbl_remove_publ(ntohl(item->type),
 298                                                        ntohl(item->lower),
 299                                                        msg_orignode(msg),
 300                                                        ntohl(item->ref),
 301                                                        ntohl(item->key));
 302
 303                        if (publ) {
 304                                tipc_nodesub_unsubscribe(&publ->subscr);
 305                                kfree(publ);
 306                        } else {
 307                                err("Unable to remove publication by node 0x%x\n"
 308                                    "(type=%u, lower=%u, ref=%u, key=%u)\n",
 309                                    msg_orignode(msg),
 310                                    ntohl(item->type), ntohl(item->lower),
 311                                    ntohl(item->ref), ntohl(item->key));
 312                        }
 313                } else {
 314                        warn("Unrecognized name table message received\n");
 315                }
 316                item++;
 317        }
 318        write_unlock_bh(&tipc_nametbl_lock);
 319        buf_discard(buf);
 320}
 321
 322/**
 323 * tipc_named_reinit - re-initialize local publication list
 324 *
 325 * This routine is called whenever TIPC networking is enabled.
 326 * All existing publications by this node that have "cluster" or "zone" scope
 327 * are updated to reflect the node's new network address.
 328 */
 329
 330void tipc_named_reinit(void)
 331{
 332        struct publication *publ;
 333
 334        write_lock_bh(&tipc_nametbl_lock);
 335
 336        list_for_each_entry(publ, &publ_root, local_list)
 337                publ->node = tipc_own_addr;
 338
 339        write_unlock_bh(&tipc_nametbl_lock);
 340}
 341