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 */
  61struct 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 */
  74struct publ_list {
  75        struct list_head list;
  76        u32 size;
  77};
  78
  79static struct publ_list publ_zone = {
  80        .list = LIST_HEAD_INIT(publ_zone.list),
  81        .size = 0,
  82};
  83
  84static struct publ_list publ_cluster = {
  85        .list = LIST_HEAD_INIT(publ_cluster.list),
  86        .size = 0,
  87};
  88
  89static struct publ_list publ_node = {
  90        .list = LIST_HEAD_INIT(publ_node.list),
  91        .size = 0,
  92};
  93
  94static 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 */
 105static 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 */
 117static 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
 130static void named_cluster_distribute(struct sk_buff *buf)
 131{
 132        struct sk_buff *buf_copy;
 133        struct tipc_node *n_ptr;
 134
 135        list_for_each_entry(n_ptr, &tipc_node_list, list) {
 136                if (tipc_node_active_links(n_ptr)) {
 137                        buf_copy = skb_copy(buf, GFP_ATOMIC);
 138                        if (!buf_copy)
 139                                break;
 140                        msg_set_destnode(buf_msg(buf_copy), n_ptr->addr);
 141                        tipc_link_send(buf_copy, n_ptr->addr, n_ptr->addr);
 142                }
 143        }
 144
 145        kfree_skb(buf);
 146}
 147
 148/**
 149 * tipc_named_publish - tell other nodes about a new publication by this node
 150 */
 151void tipc_named_publish(struct publication *publ)
 152{
 153        struct sk_buff *buf;
 154        struct distr_item *item;
 155
 156        list_add_tail(&publ->local_list, &publ_lists[publ->scope]->list);
 157        publ_lists[publ->scope]->size++;
 158
 159        if (publ->scope == TIPC_NODE_SCOPE)
 160                return;
 161
 162        buf = named_prepare_buf(PUBLICATION, ITEM_SIZE, 0);
 163        if (!buf) {
 164                pr_warn("Publication distribution failure\n");
 165                return;
 166        }
 167
 168        item = (struct distr_item *)msg_data(buf_msg(buf));
 169        publ_to_item(item, publ);
 170        named_cluster_distribute(buf);
 171}
 172
 173/**
 174 * tipc_named_withdraw - tell other nodes about a withdrawn publication by this node
 175 */
 176void tipc_named_withdraw(struct publication *publ)
 177{
 178        struct sk_buff *buf;
 179        struct distr_item *item;
 180
 181        list_del(&publ->local_list);
 182        publ_lists[publ->scope]->size--;
 183
 184        if (publ->scope == TIPC_NODE_SCOPE)
 185                return;
 186
 187        buf = named_prepare_buf(WITHDRAWAL, ITEM_SIZE, 0);
 188        if (!buf) {
 189                pr_warn("Withdrawal distribution failure\n");
 190                return;
 191        }
 192
 193        item = (struct distr_item *)msg_data(buf_msg(buf));
 194        publ_to_item(item, publ);
 195        named_cluster_distribute(buf);
 196}
 197
 198/*
 199 * named_distribute - prepare name info for bulk distribution to another node
 200 */
 201static void named_distribute(struct list_head *message_list, u32 node,
 202                             struct publ_list *pls, u32 max_item_buf)
 203{
 204        struct publication *publ;
 205        struct sk_buff *buf = NULL;
 206        struct distr_item *item = NULL;
 207        u32 left = 0;
 208        u32 rest = pls->size * ITEM_SIZE;
 209
 210        list_for_each_entry(publ, &pls->list, local_list) {
 211                if (!buf) {
 212                        left = (rest <= max_item_buf) ? rest : max_item_buf;
 213                        rest -= left;
 214                        buf = named_prepare_buf(PUBLICATION, left, node);
 215                        if (!buf) {
 216                                pr_warn("Bulk publication failure\n");
 217                                return;
 218                        }
 219                        item = (struct distr_item *)msg_data(buf_msg(buf));
 220                }
 221                publ_to_item(item, publ);
 222                item++;
 223                left -= ITEM_SIZE;
 224                if (!left) {
 225                        list_add_tail((struct list_head *)buf, message_list);
 226                        buf = NULL;
 227                }
 228        }
 229}
 230
 231/**
 232 * tipc_named_node_up - tell specified node about all publications by this node
 233 */
 234void tipc_named_node_up(unsigned long nodearg)
 235{
 236        struct tipc_node *n_ptr;
 237        struct tipc_link *l_ptr;
 238        struct list_head message_list;
 239        u32 node = (u32)nodearg;
 240        u32 max_item_buf = 0;
 241
 242        /* compute maximum amount of publication data to send per message */
 243        read_lock_bh(&tipc_net_lock);
 244        n_ptr = tipc_node_find(node);
 245        if (n_ptr) {
 246                tipc_node_lock(n_ptr);
 247                l_ptr = n_ptr->active_links[0];
 248                if (l_ptr)
 249                        max_item_buf = ((l_ptr->max_pkt - INT_H_SIZE) /
 250                                ITEM_SIZE) * ITEM_SIZE;
 251                tipc_node_unlock(n_ptr);
 252        }
 253        read_unlock_bh(&tipc_net_lock);
 254        if (!max_item_buf)
 255                return;
 256
 257        /* create list of publication messages, then send them as a unit */
 258        INIT_LIST_HEAD(&message_list);
 259
 260        read_lock_bh(&tipc_nametbl_lock);
 261        named_distribute(&message_list, node, &publ_cluster, max_item_buf);
 262        named_distribute(&message_list, node, &publ_zone, max_item_buf);
 263        read_unlock_bh(&tipc_nametbl_lock);
 264
 265        tipc_link_send_names(&message_list, (u32)node);
 266}
 267
 268/**
 269 * named_purge_publ - remove publication associated with a failed node
 270 *
 271 * Invoked for each publication issued by a newly failed node.
 272 * Removes publication structure from name table & deletes it.
 273 */
 274static void named_purge_publ(struct publication *publ)
 275{
 276        struct publication *p;
 277
 278        write_lock_bh(&tipc_nametbl_lock);
 279        p = tipc_nametbl_remove_publ(publ->type, publ->lower,
 280                                     publ->node, publ->ref, publ->key);
 281        if (p)
 282                tipc_nodesub_unsubscribe(&p->subscr);
 283        write_unlock_bh(&tipc_nametbl_lock);
 284
 285        if (p != publ) {
 286                pr_err("Unable to remove publication from failed node\n"
 287                       " (type=%u, lower=%u, node=0x%x, ref=%u, key=%u)\n",
 288                       publ->type, publ->lower, publ->node, publ->ref,
 289                       publ->key);
 290        }
 291
 292        kfree(p);
 293}
 294
 295/**
 296 * tipc_named_recv - process name table update message sent by another node
 297 */
 298void tipc_named_recv(struct sk_buff *buf)
 299{
 300        struct publication *publ;
 301        struct tipc_msg *msg = buf_msg(buf);
 302        struct distr_item *item = (struct distr_item *)msg_data(msg);
 303        u32 count = msg_data_sz(msg) / ITEM_SIZE;
 304
 305        write_lock_bh(&tipc_nametbl_lock);
 306        while (count--) {
 307                if (msg_type(msg) == PUBLICATION) {
 308                        publ = tipc_nametbl_insert_publ(ntohl(item->type),
 309                                                        ntohl(item->lower),
 310                                                        ntohl(item->upper),
 311                                                        TIPC_CLUSTER_SCOPE,
 312                                                        msg_orignode(msg),
 313                                                        ntohl(item->ref),
 314                                                        ntohl(item->key));
 315                        if (publ) {
 316                                tipc_nodesub_subscribe(&publ->subscr,
 317                                                       msg_orignode(msg),
 318                                                       publ,
 319                                                       (net_ev_handler)
 320                                                       named_purge_publ);
 321                        }
 322                } else if (msg_type(msg) == WITHDRAWAL) {
 323                        publ = tipc_nametbl_remove_publ(ntohl(item->type),
 324                                                        ntohl(item->lower),
 325                                                        msg_orignode(msg),
 326                                                        ntohl(item->ref),
 327                                                        ntohl(item->key));
 328
 329                        if (publ) {
 330                                tipc_nodesub_unsubscribe(&publ->subscr);
 331                                kfree(publ);
 332                        } else {
 333                                pr_err("Unable to remove publication by node 0x%x\n"
 334                                       " (type=%u, lower=%u, ref=%u, key=%u)\n",
 335                                       msg_orignode(msg), ntohl(item->type),
 336                                       ntohl(item->lower), ntohl(item->ref),
 337                                       ntohl(item->key));
 338                        }
 339                } else {
 340                        pr_warn("Unrecognized name table message received\n");
 341                }
 342                item++;
 343        }
 344        write_unlock_bh(&tipc_nametbl_lock);
 345        kfree_skb(buf);
 346}
 347
 348/**
 349 * tipc_named_reinit - re-initialize local publications
 350 *
 351 * This routine is called whenever TIPC networking is enabled.
 352 * All name table entries published by this node are updated to reflect
 353 * the node's new network address.
 354 */
 355void tipc_named_reinit(void)
 356{
 357        struct publication *publ;
 358        int scope;
 359
 360        write_lock_bh(&tipc_nametbl_lock);
 361
 362        for (scope = TIPC_ZONE_SCOPE; scope <= TIPC_NODE_SCOPE; scope++)
 363                list_for_each_entry(publ, &publ_lists[scope]->list, local_list)
 364                        publ->node = tipc_own_addr;
 365
 366        write_unlock_bh(&tipc_nametbl_lock);
 367}
 368
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