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  * Redistributions of source code must retain the above copyright notice, this
  13  * list of conditions and the following disclaimer.
  14  * Redistributions in binary form must reproduce the above copyright notice,
  15  * this list of conditions and the following disclaimer in the documentation
  16  * and/or other materials provided with the distribution.
  17  * Neither the names of the copyright holders nor the names of its
  18  * contributors may be used to endorse or promote products derived from this
  19  * software without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  22  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  25  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  30  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  31  * POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 #include "core.h"
  35 #include "cluster.h"
  36 #include "dbg.h"
  37 #include "link.h"
  38 #include "msg.h"
  39 #include "name_distr.h"
  40
  41 #undef  DBG_OUTPUT
  42 #define DBG_OUTPUT NULL
  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         u32 type;
  67         u32 lower;
  68         u32 upper;
  69         u32 ref;
  70         u32 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  * named_publish - tell other nodes about a new publication by this node
 115  */
 116
 117 void named_publish(struct publication *publ)
 118 {
 119         struct sk_buff *buf;
 120         struct distr_item *item;
 121
 122         list_add(&publ->local_list, &publ_root);
 123         publ_cnt++;
 124
 125         buf = named_prepare_buf(PUBLICATION, ITEM_SIZE, 0);
 126         if (!buf) {
 127                 warn("Memory squeeze; failed to distribute publication\n");
 128                 return;
 129         }
 130
 131         item = (struct distr_item *)msg_data(buf_msg(buf));
 132         publ_to_item(item, publ);
 133         dbg("named_withdraw: broadcasting publish msg\n");
 134         cluster_broadcast(buf);
 135 }
 136
 137 /**
 138  * named_withdraw - tell other nodes about a withdrawn publication by this node
 139  */
 140
 141 void 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("Memory squeeze; failed to distribute withdrawal\n");
 152                 return;
 153         }
 154
 155         item = (struct distr_item *)msg_data(buf_msg(buf));
 156         publ_to_item(item, publ);
 157         dbg("named_withdraw: broadcasting withdraw msg\n");
 158         cluster_broadcast(buf);
 159 }
 160
 161 /**
 162  * named_node_up - tell specified node about all publications by this node
 163  */
 164
 165 void named_node_up(unsigned long node)
 166 {
 167         struct publication *publ;
 168         struct distr_item *item = 0;
 169         struct sk_buff *buf = 0;
 170         u32 left = 0;
 171         u32 rest;
 172         u32 max_item_buf;
 173
 174         assert(in_own_cluster(node));
 175         read_lock_bh(&nametbl_lock);
 176         max_item_buf = TIPC_MAX_USER_MSG_SIZE / ITEM_SIZE;
 177         max_item_buf *= ITEM_SIZE;
 178         rest = publ_cnt * ITEM_SIZE;
 179
 180         list_for_each_entry(publ, &publ_root, local_list) {
 181                 if (!buf) {
 182                         left = (rest <= max_item_buf) ? rest : max_item_buf;
 183                         rest -= left;
 184                         buf = named_prepare_buf(PUBLICATION, left, node);
 185                         if (buf == NULL) {
 186                                 warn("Memory Squeeze; could not send publication\n");
 187                                 goto exit;
 188                         }
 189                         item = (struct distr_item *)msg_data(buf_msg(buf));
 190                 }
 191                 publ_to_item(item, publ);
 192                 item++;
 193                 left -= ITEM_SIZE;
 194                 if (!left) {
 195                         msg_set_link_selector(buf_msg(buf), node);
 196                         dbg("named_node_up: sending publish msg to "
 197                             "<%u.%u.%u>\n", tipc_zone(node),
 198                             tipc_cluster(node), tipc_node(node));
 199                         link_send(buf, node, node);
 200                         buf = 0;
 201                 }
 202         }
 203 exit:
 204         read_unlock_bh(&nametbl_lock);
 205 }
 206
 207 /**
 208  * node_is_down - remove publication associated with a failed node
 209  *
 210  * Invoked for each publication issued by a newly failed node.
 211  * Removes publication structure from name table & deletes it.
 212  * In rare cases the link may have come back up again when this
 213  * function is called, and we have two items representing the same
 214  * publication. Nudge this item's key to distinguish it from the other.
 215  * (Note: Publication's node subscription is already unsubscribed.)
 216  */
 217
 218 static void node_is_down(struct publication *publ)
 219 {
 220         struct publication *p;
 221         write_lock_bh(&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 = nametbl_remove_publ(publ->type, publ->lower,
 226                                 publ->node, publ->ref, publ->key);
 227         assert(p == publ);
 228         write_unlock_bh(&nametbl_lock);
 229         if (publ)
 230                 kfree(publ);
 231 }
 232
 233 /**
 234  * named_recv - process name table update message sent by another node
 235  */
 236
 237 void named_recv(struct sk_buff *buf)
 238 {
 239         struct publication *publ;
 240         struct tipc_msg *msg = buf_msg(buf);
 241         struct distr_item *item = (struct distr_item *)msg_data(msg);
 242         u32 count = msg_data_sz(msg) / ITEM_SIZE;
 243
 244         write_lock_bh(&nametbl_lock);
 245         while (count--) {
 246                 if (msg_type(msg) == PUBLICATION) {
 247                         dbg("named_recv: got publication for %u, %u, %u\n",
 248                             ntohl(item->type), ntohl(item->lower),
 249                             ntohl(item->upper));
 250                         publ = nametbl_insert_publ(ntohl(item->type),
 251                                                    ntohl(item->lower),
 252                                                    ntohl(item->upper),
 253                                                    TIPC_CLUSTER_SCOPE,
 254                                                    msg_orignode(msg),
 255                                                    ntohl(item->ref),
 256                                                    ntohl(item->key));
 257                         if (publ) {
 258                                 nodesub_subscribe(&publ->subscr,
 259                                                   msg_orignode(msg),
 260                                                   publ,
 261                                                   (net_ev_handler)node_is_down);
 262                         }
 263                 } else if (msg_type(msg) == WITHDRAWAL) {
 264                         dbg("named_recv: got withdrawl for %u, %u, %u\n",
 265                             ntohl(item->type), ntohl(item->lower),
 266                             ntohl(item->upper));
 267                         publ = nametbl_remove_publ(ntohl(item->type),
 268                                                    ntohl(item->lower),
 269                                                    msg_orignode(msg),
 270                                                    ntohl(item->ref),
 271                                                    ntohl(item->key));
 272
 273                         if (publ) {
 274                                 nodesub_unsubscribe(&publ->subscr);
 275                                 kfree(publ);
 276                         }
 277                 } else {
 278                         warn("named_recv: unknown msg\n");
 279                 }
 280                 item++;
 281         }
 282         write_unlock_bh(&nametbl_lock);
 283         buf_discard(buf);
 284 }
 285
 286 /**
 287  * named_reinit - re-initialize local publication list
 288  *
 289  * This routine is called whenever TIPC networking is (re)enabled.
 290  * All existing publications by this node that have "cluster" or "zone" scope
 291  * are updated to reflect the node's current network address.
 292  * (If the node's address is unchanged, the update loop terminates immediately.)
 293  */
 294
 295 void named_reinit(void)
 296 {
 297         struct publication *publ;
 298
 299         write_lock_bh(&nametbl_lock);
 300         list_for_each_entry(publ, &publ_root, local_list) {
 301                 if (publ->node == tipc_own_addr)
 302                         break;
 303                 publ->node = tipc_own_addr;
 304         }
 305         write_unlock_bh(&nametbl_lock);
 306 }