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