net/tipc/name_distr.c

   1 /*
   2  * net/tipc/name_distr.c: TIPC name distribution code
   3  *
   4  * Copyright (c) 2003-2005, Ericsson Research Canada
   5  * Copyright (c) 2005, Wind River Systems
   6  * Copyright (c) 2005-2006, Ericsson AB
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the names of the copyright holders nor the names of its
  18  *    contributors may be used to endorse or promote products derived from
  19  *    this software without specific prior written permission.
  20  *
  21  * Alternatively, this software may be distributed under the terms of the
  22  * GNU General Public License ("GPL") version 2 as published by the Free
  23  * Software Foundation.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  26  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  28  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  29  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  35  * POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38 #include "core.h"
  39 #include "cluster.h"
  40 #include "dbg.h"
  41 #include "link.h"
  42 #include "msg.h"
  43 #include "name_distr.h"
  44
  45 #undef  DBG_OUTPUT
  46 #define DBG_OUTPUT NULL
  47
  48 #define ITEM_SIZE sizeof(struct distr_item)
  49
  50 /**
  51  * struct distr_item - publication info distributed to other nodes
  52  * @type: name sequence type
  53  * @lower: name sequence lower bound
  54  * @upper: name sequence upper bound
  55  * @ref: publishing port reference
  56  * @key: publication key
  57  *
  58  * ===> All fields are stored in network byte order. <===
  59  *
  60  * First 3 fields identify (name or) name sequence being published.
  61  * Reference field uniquely identifies port that published name sequence.
  62  * Key field uniquely identifies publication, in the event a port has
  63  * multiple publications of the same name sequence.
  64  *
  65  * Note: There is no field that identifies the publishing node because it is
  66  * the same for all items contained within a publication message.
  67  */
  68
  69 struct distr_item {
  70         u32 type;
  71         u32 lower;
  72         u32 upper;
  73         u32 ref;
  74         u32 key;
  75 };
  76
  77 /**
  78  * List of externally visible publications by this node --
  79  * that is, all publications having scope > TIPC_NODE_SCOPE.
  80  */
  81
  82 static LIST_HEAD(publ_root);
  83 static u32 publ_cnt = 0;
  84
  85 /**
  86  * publ_to_item - add publication info to a publication message
  87  */
  88
  89 static void publ_to_item(struct distr_item *i, struct publication *p)
  90 {
  91         i->type = htonl(p->type);
  92         i->lower = htonl(p->lower);
  93         i->upper = htonl(p->upper);
  94         i->ref = htonl(p->ref);
  95         i->key = htonl(p->key);
  96         dbg("publ_to_item: %u, %u, %u\n", p->type, p->lower, p->upper);
  97 }
  98
  99 /**
 100  * named_prepare_buf - allocate & initialize a publication message
 101  */
 102
 103 static struct sk_buff *named_prepare_buf(u32 type, u32 size, u32 dest)
 104 {
 105         struct sk_buff *buf = buf_acquire(LONG_H_SIZE + size);
 106         struct tipc_msg *msg;
 107
 108         if (buf != NULL) {
 109                 msg = buf_msg(buf);
 110                 msg_init(msg, NAME_DISTRIBUTOR, type, TIPC_OK,
 111                          LONG_H_SIZE, dest);
 112                 msg_set_size(msg, LONG_H_SIZE + size);
 113         }
 114         return buf;
 115 }
 116
 117 /**
 118  * named_publish - tell other nodes about a new publication by this node
 119  */
 120
 121 void named_publish(struct publication *publ)
 122 {
 123         struct sk_buff *buf;
 124         struct distr_item *item;
 125
 126         list_add(&publ->local_list, &publ_root);
 127         publ_cnt++;
 128
 129         buf = named_prepare_buf(PUBLICATION, ITEM_SIZE, 0);
 130         if (!buf) {
 131                 warn("Memory squeeze; failed to distribute publication\n");
 132                 return;
 133         }
 134
 135         item = (struct distr_item *)msg_data(buf_msg(buf));
 136         publ_to_item(item, publ);
 137         dbg("named_withdraw: broadcasting publish msg\n");
 138         cluster_broadcast(buf);
 139 }
 140
 141 /**
 142  * named_withdraw - tell other nodes about a withdrawn publication by this node
 143  */
 144
 145 void named_withdraw(struct publication *publ)
 146 {
 147         struct sk_buff *buf;
 148         struct distr_item *item;
 149
 150         list_del(&publ->local_list);
 151         publ_cnt--;
 152
 153         buf = named_prepare_buf(WITHDRAWAL, ITEM_SIZE, 0);
 154         if (!buf) {
 155                 warn("Memory squeeze; failed to distribute withdrawal\n");
 156                 return;
 157         }
 158
 159         item = (struct distr_item *)msg_data(buf_msg(buf));
 160         publ_to_item(item, publ);
 161         dbg("named_withdraw: broadcasting withdraw msg\n");
 162         cluster_broadcast(buf);
 163 }
 164
 165 /**
 166  * named_node_up - tell specified node about all publications by this node
 167  */
 168
 169 void named_node_up(unsigned long node)
 170 {
 171         struct publication *publ;
 172         struct distr_item *item = 0;
 173         struct sk_buff *buf = 0;
 174         u32 left = 0;
 175         u32 rest;
 176         u32 max_item_buf;
 177
 178         assert(in_own_cluster(node));
 179         read_lock_bh(&nametbl_lock);
 180         max_item_buf = TIPC_MAX_USER_MSG_SIZE / ITEM_SIZE;
 181         max_item_buf *= ITEM_SIZE;
 182         rest = publ_cnt * ITEM_SIZE;
 183
 184         list_for_each_entry(publ, &publ_root, local_list) {
 185                 if (!buf) {
 186                         left = (rest <= max_item_buf) ? rest : max_item_buf;
 187                         rest -= left;
 188                         buf = named_prepare_buf(PUBLICATION, left, node);
 189                         if (buf == NULL) {
 190                                 warn("Memory Squeeze; could not send publication\n");
 191                                 goto exit;
 192                         }
 193                         item = (struct distr_item *)msg_data(buf_msg(buf));
 194                 }
 195                 publ_to_item(item, publ);
 196                 item++;
 197                 left -= ITEM_SIZE;
 198                 if (!left) {
 199                         msg_set_link_selector(buf_msg(buf), node);
 200                         dbg("named_node_up: sending publish msg to "
 201                             "<%u.%u.%u>\n", tipc_zone(node),
 202                             tipc_cluster(node), tipc_node(node));
 203                         link_send(buf, node, node);
 204                         buf = 0;
 205                 }
 206         }
 207 exit:
 208         read_unlock_bh(&nametbl_lock);
 209 }
 210
 211 /**
 212  * node_is_down - remove publication associated with a failed node
 213  *
 214  * Invoked for each publication issued by a newly failed node.
 215  * Removes publication structure from name table & deletes it.
 216  * In rare cases the link may have come back up again when this
 217  * function is called, and we have two items representing the same
 218  * publication. Nudge this item's key to distinguish it from the other.
 219  * (Note: Publication's node subscription is already unsubscribed.)
 220  */
 221
 222 static void node_is_down(struct publication *publ)
 223 {
 224         struct publication *p;
 225         write_lock_bh(&nametbl_lock);
 226         dbg("node_is_down: withdrawing %u, %u, %u\n",
 227             publ->type, publ->lower, publ->upper);
 228         publ->key += 1222345;
 229         p = nametbl_remove_publ(publ->type, publ->lower,
 230                                 publ->node, publ->ref, publ->key);
 231         assert(p == publ);
 232         write_unlock_bh(&nametbl_lock);
 233         if (publ)
 234                 kfree(publ);
 235 }
 236
 237 /**
 238  * named_recv - process name table update message sent by another node
 239  */
 240
 241 void named_recv(struct sk_buff *buf)
 242 {
 243         struct publication *publ;
 244         struct tipc_msg *msg = buf_msg(buf);
 245         struct distr_item *item = (struct distr_item *)msg_data(msg);
 246         u32 count = msg_data_sz(msg) / ITEM_SIZE;
 247
 248         write_lock_bh(&nametbl_lock);
 249         while (count--) {
 250                 if (msg_type(msg) == PUBLICATION) {
 251                         dbg("named_recv: got publication for %u, %u, %u\n",
 252                             ntohl(item->type), ntohl(item->lower),
 253                             ntohl(item->upper));
 254                         publ = nametbl_insert_publ(ntohl(item->type),
 255                                                    ntohl(item->lower),
 256                                                    ntohl(item->upper),
 257                                                    TIPC_CLUSTER_SCOPE,
 258                                                    msg_orignode(msg),
 259                                                    ntohl(item->ref),
 260                                                    ntohl(item->key));
 261                         if (publ) {
 262                                 nodesub_subscribe(&publ->subscr,
 263                                                   msg_orignode(msg),
 264                                                   publ,
 265                                                   (net_ev_handler)node_is_down);
 266                         }
 267                 } else if (msg_type(msg) == WITHDRAWAL) {
 268                         dbg("named_recv: got withdrawl for %u, %u, %u\n",
 269                             ntohl(item->type), ntohl(item->lower),
 270                             ntohl(item->upper));
 271                         publ = nametbl_remove_publ(ntohl(item->type),
 272                                                    ntohl(item->lower),
 273                                                    msg_orignode(msg),
 274                                                    ntohl(item->ref),
 275                                                    ntohl(item->key));
 276
 277                         if (publ) {
 278                                 nodesub_unsubscribe(&publ->subscr);
 279                                 kfree(publ);
 280                         }
 281                 } else {
 282                         warn("named_recv: unknown msg\n");
 283                 }
 284                 item++;
 285         }
 286         write_unlock_bh(&nametbl_lock);
 287         buf_discard(buf);
 288 }
 289
 290 /**
 291  * named_reinit - re-initialize local publication list
 292  *
 293  * This routine is called whenever TIPC networking is (re)enabled.
 294  * All existing publications by this node that have "cluster" or "zone" scope
 295  * are updated to reflect the node's current network address.
 296  * (If the node's address is unchanged, the update loop terminates immediately.)
 297  */
 298
 299 void named_reinit(void)
 300 {
 301         struct publication *publ;
 302
 303         write_lock_bh(&nametbl_lock);
 304         list_for_each_entry(publ, &publ_root, local_list) {
 305                 if (publ->node == tipc_own_addr)
 306                         break;
 307                 publ->node = tipc_own_addr;
 308         }
 309         write_unlock_bh(&nametbl_lock);
 310 }