net/tipc/name_distr.c

   1 /*
   2  * net/tipc/name_distr.c: TIPC name distribution code
   3  *
   4  * Copyright (c) 2000-2006, 2014, 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 int sysctl_tipc_named_timeout __read_mostly = 2000;
  42
  43 struct distr_queue_item {
  44         struct distr_item i;
  45         u32 dtype;
  46         u32 node;
  47         unsigned long expires;
  48         struct list_head next;
  49 };
  50
  51 /**
  52  * publ_to_item - add publication info to a publication message
  53  */
  54 static void publ_to_item(struct distr_item *i, struct publication *p)
  55 {
  56         i->type = htonl(p->type);
  57         i->lower = htonl(p->lower);
  58         i->upper = htonl(p->upper);
  59         i->port = htonl(p->port);
  60         i->key = htonl(p->key);
  61 }
  62
  63 /**
  64  * named_prepare_buf - allocate & initialize a publication message
  65  *
  66  * The buffer returned is of size INT_H_SIZE + payload size
  67  */
  68 static struct sk_buff *named_prepare_buf(struct net *net, u32 type, u32 size,
  69                                          u32 dest)
  70 {
  71         struct sk_buff *buf = tipc_buf_acquire(INT_H_SIZE + size, GFP_ATOMIC);
  72         u32 self = tipc_own_addr(net);
  73         struct tipc_msg *msg;
  74
  75         if (buf != NULL) {
  76                 msg = buf_msg(buf);
  77                 tipc_msg_init(self, msg, NAME_DISTRIBUTOR,
  78                               type, INT_H_SIZE, dest);
  79                 msg_set_size(msg, INT_H_SIZE + size);
  80         }
  81         return buf;
  82 }
  83
  84 /**
  85  * tipc_named_publish - tell other nodes about a new publication by this node
  86  */
  87 struct sk_buff *tipc_named_publish(struct net *net, struct publication *publ)
  88 {
  89         struct name_table *nt = tipc_name_table(net);
  90         struct distr_item *item;
  91         struct sk_buff *skb;
  92
  93         if (publ->scope == TIPC_NODE_SCOPE) {
  94                 list_add_tail_rcu(&publ->binding_node, &nt->node_scope);
  95                 return NULL;
  96         }
  97         write_lock_bh(&nt->cluster_scope_lock);
  98         list_add_tail(&publ->binding_node, &nt->cluster_scope);
  99         write_unlock_bh(&nt->cluster_scope_lock);
 100         skb = named_prepare_buf(net, PUBLICATION, ITEM_SIZE, 0);
 101         if (!skb) {
 102                 pr_warn("Publication distribution failure\n");
 103                 return NULL;
 104         }
 105
 106         item = (struct distr_item *)msg_data(buf_msg(skb));
 107         publ_to_item(item, publ);
 108         return skb;
 109 }
 110
 111 /**
 112  * tipc_named_withdraw - tell other nodes about a withdrawn publication by this node
 113  */
 114 struct sk_buff *tipc_named_withdraw(struct net *net, struct publication *publ)
 115 {
 116         struct name_table *nt = tipc_name_table(net);
 117         struct sk_buff *buf;
 118         struct distr_item *item;
 119
 120         write_lock_bh(&nt->cluster_scope_lock);
 121         list_del(&publ->binding_node);
 122         write_unlock_bh(&nt->cluster_scope_lock);
 123         if (publ->scope == TIPC_NODE_SCOPE)
 124                 return NULL;
 125
 126         buf = named_prepare_buf(net, WITHDRAWAL, ITEM_SIZE, 0);
 127         if (!buf) {
 128                 pr_warn("Withdrawal distribution failure\n");
 129                 return NULL;
 130         }
 131
 132         item = (struct distr_item *)msg_data(buf_msg(buf));
 133         publ_to_item(item, publ);
 134         return buf;
 135 }
 136
 137 /**
 138  * named_distribute - prepare name info for bulk distribution to another node
 139  * @list: list of messages (buffers) to be returned from this function
 140  * @dnode: node to be updated
 141  * @pls: linked list of publication items to be packed into buffer chain
 142  */
 143 static void named_distribute(struct net *net, struct sk_buff_head *list,
 144                              u32 dnode, struct list_head *pls)
 145 {
 146         struct publication *publ;
 147         struct sk_buff *skb = NULL;
 148         struct distr_item *item = NULL;
 149         u32 msg_dsz = ((tipc_node_get_mtu(net, dnode, 0) - INT_H_SIZE) /
 150                         ITEM_SIZE) * ITEM_SIZE;
 151         u32 msg_rem = msg_dsz;
 152
 153         list_for_each_entry(publ, pls, binding_node) {
 154                 /* Prepare next buffer: */
 155                 if (!skb) {
 156                         skb = named_prepare_buf(net, PUBLICATION, msg_rem,
 157                                                 dnode);
 158                         if (!skb) {
 159                                 pr_warn("Bulk publication failure\n");
 160                                 return;
 161                         }
 162                         msg_set_bc_ack_invalid(buf_msg(skb), true);
 163                         item = (struct distr_item *)msg_data(buf_msg(skb));
 164                 }
 165
 166                 /* Pack publication into message: */
 167                 publ_to_item(item, publ);
 168                 item++;
 169                 msg_rem -= ITEM_SIZE;
 170
 171                 /* Append full buffer to list: */
 172                 if (!msg_rem) {
 173                         __skb_queue_tail(list, skb);
 174                         skb = NULL;
 175                         msg_rem = msg_dsz;
 176                 }
 177         }
 178         if (skb) {
 179                 msg_set_size(buf_msg(skb), INT_H_SIZE + (msg_dsz - msg_rem));
 180                 skb_trim(skb, INT_H_SIZE + (msg_dsz - msg_rem));
 181                 __skb_queue_tail(list, skb);
 182         }
 183 }
 184
 185 /**
 186  * tipc_named_node_up - tell specified node about all publications by this node
 187  */
 188 void tipc_named_node_up(struct net *net, u32 dnode)
 189 {
 190         struct name_table *nt = tipc_name_table(net);
 191         struct sk_buff_head head;
 192
 193         skb_queue_head_init(&head);
 194
 195         read_lock_bh(&nt->cluster_scope_lock);
 196         named_distribute(net, &head, dnode, &nt->cluster_scope);
 197         tipc_node_xmit(net, &head, dnode, 0);
 198         read_unlock_bh(&nt->cluster_scope_lock);
 199 }
 200
 201 /**
 202  * tipc_publ_purge - remove publication associated with a failed node
 203  *
 204  * Invoked for each publication issued by a newly failed node.
 205  * Removes publication structure from name table & deletes it.
 206  */
 207 static void tipc_publ_purge(struct net *net, struct publication *publ, u32 addr)
 208 {
 209         struct tipc_net *tn = tipc_net(net);
 210         struct publication *p;
 211
 212         spin_lock_bh(&tn->nametbl_lock);
 213         p = tipc_nametbl_remove_publ(net, publ->type, publ->lower, publ->upper,
 214                                      publ->node, publ->key);
 215         if (p)
 216                 tipc_node_unsubscribe(net, &p->binding_node, addr);
 217         spin_unlock_bh(&tn->nametbl_lock);
 218
 219         if (p != publ) {
 220                 pr_err("Unable to remove publication from failed node\n"
 221                        " (type=%u, lower=%u, node=0x%x, port=%u, key=%u)\n",
 222                        publ->type, publ->lower, publ->node, publ->port,
 223                        publ->key);
 224         }
 225
 226         if (p)
 227                 kfree_rcu(p, rcu);
 228 }
 229
 230 /**
 231  * tipc_dist_queue_purge - remove deferred updates from a node that went down
 232  */
 233 static void tipc_dist_queue_purge(struct net *net, u32 addr)
 234 {
 235         struct tipc_net *tn = net_generic(net, tipc_net_id);
 236         struct distr_queue_item *e, *tmp;
 237
 238         spin_lock_bh(&tn->nametbl_lock);
 239         list_for_each_entry_safe(e, tmp, &tn->dist_queue, next) {
 240                 if (e->node != addr)
 241                         continue;
 242                 list_del(&e->next);
 243                 kfree(e);
 244         }
 245         spin_unlock_bh(&tn->nametbl_lock);
 246 }
 247
 248 void tipc_publ_notify(struct net *net, struct list_head *nsub_list, u32 addr)
 249 {
 250         struct publication *publ, *tmp;
 251
 252         list_for_each_entry_safe(publ, tmp, nsub_list, binding_node)
 253                 tipc_publ_purge(net, publ, addr);
 254         tipc_dist_queue_purge(net, addr);
 255 }
 256
 257 /**
 258  * tipc_update_nametbl - try to process a nametable update and notify
 259  *                       subscribers
 260  *
 261  * tipc_nametbl_lock must be held.
 262  * Returns the publication item if successful, otherwise NULL.
 263  */
 264 static bool tipc_update_nametbl(struct net *net, struct distr_item *i,
 265                                 u32 node, u32 dtype)
 266 {
 267         struct publication *p = NULL;
 268         u32 lower = ntohl(i->lower);
 269         u32 upper = ntohl(i->upper);
 270         u32 type = ntohl(i->type);
 271         u32 port = ntohl(i->port);
 272         u32 key = ntohl(i->key);
 273
 274         if (dtype == PUBLICATION) {
 275                 p = tipc_nametbl_insert_publ(net, type, lower, upper,
 276                                              TIPC_CLUSTER_SCOPE, node,
 277                                              port, key);
 278                 if (p) {
 279                         tipc_node_subscribe(net, &p->binding_node, node);
 280                         return true;
 281                 }
 282         } else if (dtype == WITHDRAWAL) {
 283                 p = tipc_nametbl_remove_publ(net, type, lower,
 284                                              upper, node, key);
 285                 if (p) {
 286                         tipc_node_unsubscribe(net, &p->binding_node, node);
 287                         kfree_rcu(p, rcu);
 288                         return true;
 289                 }
 290                 pr_warn_ratelimited("Failed to remove binding %u,%u from %x\n",
 291                                     type, lower, node);
 292         } else {
 293                 pr_warn("Unrecognized name table message received\n");
 294         }
 295         return false;
 296 }
 297
 298 /**
 299  * tipc_named_rcv - process name table update messages sent by another node
 300  */
 301 void tipc_named_rcv(struct net *net, struct sk_buff_head *inputq)
 302 {
 303         struct tipc_net *tn = net_generic(net, tipc_net_id);
 304         struct tipc_msg *msg;
 305         struct distr_item *item;
 306         uint count;
 307         u32 node;
 308         struct sk_buff *skb;
 309         int mtype;
 310
 311         spin_lock_bh(&tn->nametbl_lock);
 312         for (skb = skb_dequeue(inputq); skb; skb = skb_dequeue(inputq)) {
 313                 skb_linearize(skb);
 314                 msg = buf_msg(skb);
 315                 mtype = msg_type(msg);
 316                 item = (struct distr_item *)msg_data(msg);
 317                 count = msg_data_sz(msg) / ITEM_SIZE;
 318                 node = msg_orignode(msg);
 319                 while (count--) {
 320                         tipc_update_nametbl(net, item, node, mtype);
 321                         item++;
 322                 }
 323                 kfree_skb(skb);
 324         }
 325         spin_unlock_bh(&tn->nametbl_lock);
 326 }
 327
 328 /**
 329  * tipc_named_reinit - re-initialize local publications
 330  *
 331  * This routine is called whenever TIPC networking is enabled.
 332  * All name table entries published by this node are updated to reflect
 333  * the node's new network address.
 334  */
 335 void tipc_named_reinit(struct net *net)
 336 {
 337         struct name_table *nt = tipc_name_table(net);
 338         struct tipc_net *tn = tipc_net(net);
 339         struct publication *publ;
 340         u32 self = tipc_own_addr(net);
 341
 342         spin_lock_bh(&tn->nametbl_lock);
 343
 344         list_for_each_entry_rcu(publ, &nt->node_scope, binding_node)
 345                 publ->node = self;
 346         list_for_each_entry_rcu(publ, &nt->cluster_scope, binding_node)
 347                 publ->node = self;
 348
 349         spin_unlock_bh(&tn->nametbl_lock);
 350 }