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                 msg_init(msg, NAME_DISTRIBUTOR, type, TIPC_OK,
 107                          LONG_H_SIZE, dest);
 108                 msg_set_size(msg, LONG_H_SIZE + size);
 109         }
 110         return buf;
 111 }
 112
 113 /**
 114  * tipc_named_publish - tell other nodes about a new publication by this node
 115  */
 116
 117 void tipc_named_publish(struct publication *publ)
 118 {
 119         struct sk_buff *buf;
 120         struct distr_item *item;
 121
 122         list_add_tail(&publ->local_list, &publ_root);
 123         publ_cnt++;
 124
 125         buf = named_prepare_buf(PUBLICATION, ITEM_SIZE, 0);
 126         if (!buf) {
 127                 warn("Publication distribution failure\n");
 128                 return;
 129         }
 130
 131         item = (struct distr_item *)msg_data(buf_msg(buf));
 132         publ_to_item(item, publ);
 133         dbg("tipc_named_withdraw: broadcasting publish msg\n");
 134         tipc_cltr_broadcast(buf);
 135 }
 136
 137 /**
 138  * tipc_named_withdraw - tell other nodes about a withdrawn publication by this node
 139  */
 140
 141 void tipc_named_withdraw(struct publication *publ)
 142 {
 143         struct sk_buff *buf;
 144         struct distr_item *item;
 145
 146         list_del(&publ->local_list);
 147         publ_cnt--;
 148
 149         buf = named_prepare_buf(WITHDRAWAL, ITEM_SIZE, 0);
 150         if (!buf) {
 151                 warn("Withdrawl distribution failure\n");
 152                 return;
 153         }
 154
 155         item = (struct distr_item *)msg_data(buf_msg(buf));
 156         publ_to_item(item, publ);
 157         dbg("tipc_named_withdraw: broadcasting withdraw msg\n");
 158         tipc_cltr_broadcast(buf);
 159 }
 160
 161 /**
 162  * tipc_named_node_up - tell specified node about all publications by this node
 163  */
 164
 165 void tipc_named_node_up(unsigned long node)
 166 {
 167         struct publication *publ;
 168         struct distr_item *item = NULL;
 169         struct sk_buff *buf = NULL;
 170         u32 left = 0;
 171         u32 rest;
 172         u32 max_item_buf;
 173
 174         read_lock_bh(&tipc_nametbl_lock);
 175         max_item_buf = TIPC_MAX_USER_MSG_SIZE / ITEM_SIZE;
 176         max_item_buf *= ITEM_SIZE;
 177         rest = publ_cnt * ITEM_SIZE;
 178
 179         list_for_each_entry(publ, &publ_root, local_list) {
 180                 if (!buf) {
 181                         left = (rest <= max_item_buf) ? rest : max_item_buf;
 182                         rest -= left;
 183                         buf = named_prepare_buf(PUBLICATION, left, node);
 184                         if (!buf) {
 185                                 warn("Bulk publication distribution failure\n");
 186                                 goto exit;
 187                         }
 188                         item = (struct distr_item *)msg_data(buf_msg(buf));
 189                 }
 190                 publ_to_item(item, publ);
 191                 item++;
 192                 left -= ITEM_SIZE;
 193                 if (!left) {
 194                         msg_set_link_selector(buf_msg(buf), node);
 195                         dbg("tipc_named_node_up: sending publish msg to "
 196                             "<%u.%u.%u>\n", tipc_zone(node),
 197                             tipc_cluster(node), tipc_node(node));
 198                         tipc_link_send(buf, node, node);
 199                         buf = NULL;
 200                 }
 201         }
 202 exit:
 203         read_unlock_bh(&tipc_nametbl_lock);
 204 }
 205
 206 /**
 207  * node_is_down - remove publication associated with a failed node
 208  *
 209  * Invoked for each publication issued by a newly failed node.
 210  * Removes publication structure from name table & deletes it.
 211  * In rare cases the link may have come back up again when this
 212  * function is called, and we have two items representing the same
 213  * publication. Nudge this item's key to distinguish it from the other.
 214  * (Note: Publication's node subscription is already unsubscribed.)
 215  */
 216
 217 static void node_is_down(struct publication *publ)
 218 {
 219         struct publication *p;
 220
 221         write_lock_bh(&tipc_nametbl_lock);
 222         dbg("node_is_down: withdrawing %u, %u, %u\n",
 223             publ->type, publ->lower, publ->upper);
 224         publ->key += 1222345;
 225         p = tipc_nametbl_remove_publ(publ->type, publ->lower,
 226                                      publ->node, publ->ref, publ->key);
 227         write_unlock_bh(&tipc_nametbl_lock);
 228
 229         if (p != publ) {
 230                 err("Unable to remove publication from failed node\n"
 231                     "(type=%u, lower=%u, node=0x%x, ref=%u, key=%u)\n",
 232                     publ->type, publ->lower, publ->node, publ->ref, publ->key);
 233         }
 234
 235         if (p) {
 236                 kfree(p);
 237         }
 238 }
 239
 240 /**
 241  * tipc_named_recv - process name table update message sent by another node
 242  */
 243
 244 void tipc_named_recv(struct sk_buff *buf)
 245 {
 246         struct publication *publ;
 247         struct tipc_msg *msg = buf_msg(buf);
 248         struct distr_item *item = (struct distr_item *)msg_data(msg);
 249         u32 count = msg_data_sz(msg) / ITEM_SIZE;
 250
 251         write_lock_bh(&tipc_nametbl_lock);
 252         while (count--) {
 253                 if (msg_type(msg) == PUBLICATION) {
 254                         dbg("tipc_named_recv: got publication for %u, %u, %u\n",
 255                             ntohl(item->type), ntohl(item->lower),
 256                             ntohl(item->upper));
 257                         publ = tipc_nametbl_insert_publ(ntohl(item->type),
 258                                                         ntohl(item->lower),
 259                                                         ntohl(item->upper),
 260                                                         TIPC_CLUSTER_SCOPE,
 261                                                         msg_orignode(msg),
 262                                                         ntohl(item->ref),
 263                                                         ntohl(item->key));
 264                         if (publ) {
 265                                 tipc_nodesub_subscribe(&publ->subscr,
 266                                                        msg_orignode(msg),
 267                                                        publ,
 268                                                        (net_ev_handler)node_is_down);
 269                         }
 270                 } else if (msg_type(msg) == WITHDRAWAL) {
 271                         dbg("tipc_named_recv: got withdrawl for %u, %u, %u\n",
 272                             ntohl(item->type), ntohl(item->lower),
 273                             ntohl(item->upper));
 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 }