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 /**
  44  * struct tipc_dist_queue - queue holding deferred name table updates
  45  */
  46 static struct list_head tipc_dist_queue = LIST_HEAD_INIT(tipc_dist_queue);
  47
  48 struct distr_queue_item {
  49         struct distr_item i;
  50         u32 dtype;
  51         u32 node;
  52         unsigned long expires;
  53         struct list_head next;
  54 };
  55
  56 /**
  57  * publ_to_item - add publication info to a publication message
  58  */
  59 static void publ_to_item(struct distr_item *i, struct publication *p)
  60 {
  61         i->type = htonl(p->type);
  62         i->lower = htonl(p->lower);
  63         i->upper = htonl(p->upper);
  64         i->ref = htonl(p->ref);
  65         i->key = htonl(p->key);
  66 }
  67
  68 /**
  69  * named_prepare_buf - allocate & initialize a publication message
  70  */
  71 static struct sk_buff *named_prepare_buf(struct net *net, u32 type, u32 size,
  72                                          u32 dest)
  73 {
  74         struct tipc_net *tn = net_generic(net, tipc_net_id);
  75         struct sk_buff *buf = tipc_buf_acquire(INT_H_SIZE + size);
  76         struct tipc_msg *msg;
  77
  78         if (buf != NULL) {
  79                 msg = buf_msg(buf);
  80                 tipc_msg_init(tn->own_addr, msg, NAME_DISTRIBUTOR, type,
  81                               INT_H_SIZE, dest);
  82                 msg_set_size(msg, INT_H_SIZE + size);
  83         }
  84         return buf;
  85 }
  86
  87 void named_cluster_distribute(struct net *net, struct sk_buff *skb)
  88 {
  89         struct tipc_net *tn = net_generic(net, tipc_net_id);
  90         struct sk_buff *oskb;
  91         struct tipc_node *node;
  92         u32 dnode;
  93
  94         rcu_read_lock();
  95         list_for_each_entry_rcu(node, &tn->node_list, list) {
  96                 dnode = node->addr;
  97                 if (in_own_node(net, dnode))
  98                         continue;
  99                 if (!tipc_node_active_links(node))
 100                         continue;
 101                 oskb = skb_copy(skb, GFP_ATOMIC);
 102                 if (!oskb)
 103                         break;
 104                 msg_set_destnode(buf_msg(oskb), dnode);
 105                 tipc_link_xmit_skb(net, oskb, dnode, dnode);
 106         }
 107         rcu_read_unlock();
 108
 109         kfree_skb(skb);
 110 }
 111
 112 /**
 113  * tipc_named_publish - tell other nodes about a new publication by this node
 114  */
 115 struct sk_buff *tipc_named_publish(struct net *net, struct publication *publ)
 116 {
 117         struct tipc_net *tn = net_generic(net, tipc_net_id);
 118         struct sk_buff *buf;
 119         struct distr_item *item;
 120
 121         list_add_tail_rcu(&publ->local_list,
 122                           &tn->nametbl->publ_list[publ->scope]);
 123
 124         if (publ->scope == TIPC_NODE_SCOPE)
 125                 return NULL;
 126
 127         buf = named_prepare_buf(net, PUBLICATION, ITEM_SIZE, 0);
 128         if (!buf) {
 129                 pr_warn("Publication distribution failure\n");
 130                 return NULL;
 131         }
 132
 133         item = (struct distr_item *)msg_data(buf_msg(buf));
 134         publ_to_item(item, publ);
 135         return buf;
 136 }
 137
 138 /**
 139  * tipc_named_withdraw - tell other nodes about a withdrawn publication by this node
 140  */
 141 struct sk_buff *tipc_named_withdraw(struct net *net, struct publication *publ)
 142 {
 143         struct sk_buff *buf;
 144         struct distr_item *item;
 145
 146         list_del(&publ->local_list);
 147
 148         if (publ->scope == TIPC_NODE_SCOPE)
 149                 return NULL;
 150
 151         buf = named_prepare_buf(net, WITHDRAWAL, ITEM_SIZE, 0);
 152         if (!buf) {
 153                 pr_warn("Withdrawal distribution failure\n");
 154                 return NULL;
 155         }
 156
 157         item = (struct distr_item *)msg_data(buf_msg(buf));
 158         publ_to_item(item, publ);
 159         return buf;
 160 }
 161
 162 /**
 163  * named_distribute - prepare name info for bulk distribution to another node
 164  * @list: list of messages (buffers) to be returned from this function
 165  * @dnode: node to be updated
 166  * @pls: linked list of publication items to be packed into buffer chain
 167  */
 168 static void named_distribute(struct net *net, struct sk_buff_head *list,
 169                              u32 dnode, struct list_head *pls)
 170 {
 171         struct publication *publ;
 172         struct sk_buff *skb = NULL;
 173         struct distr_item *item = NULL;
 174         uint msg_dsz = (tipc_node_get_mtu(net, dnode, 0) / ITEM_SIZE) *
 175                         ITEM_SIZE;
 176         uint msg_rem = msg_dsz;
 177
 178         list_for_each_entry(publ, pls, local_list) {
 179                 /* Prepare next buffer: */
 180                 if (!skb) {
 181                         skb = named_prepare_buf(net, PUBLICATION, msg_rem,
 182                                                 dnode);
 183                         if (!skb) {
 184                                 pr_warn("Bulk publication failure\n");
 185                                 return;
 186                         }
 187                         item = (struct distr_item *)msg_data(buf_msg(skb));
 188                 }
 189
 190                 /* Pack publication into message: */
 191                 publ_to_item(item, publ);
 192                 item++;
 193                 msg_rem -= ITEM_SIZE;
 194
 195                 /* Append full buffer to list: */
 196                 if (!msg_rem) {
 197                         __skb_queue_tail(list, skb);
 198                         skb = NULL;
 199                         msg_rem = msg_dsz;
 200                 }
 201         }
 202         if (skb) {
 203                 msg_set_size(buf_msg(skb), INT_H_SIZE + (msg_dsz - msg_rem));
 204                 skb_trim(skb, INT_H_SIZE + (msg_dsz - msg_rem));
 205                 __skb_queue_tail(list, skb);
 206         }
 207 }
 208
 209 /**
 210  * tipc_named_node_up - tell specified node about all publications by this node
 211  */
 212 void tipc_named_node_up(struct net *net, u32 dnode)
 213 {
 214         struct tipc_net *tn = net_generic(net, tipc_net_id);
 215         struct sk_buff_head head;
 216
 217         __skb_queue_head_init(&head);
 218
 219         rcu_read_lock();
 220         named_distribute(net, &head, dnode,
 221                          &tn->nametbl->publ_list[TIPC_CLUSTER_SCOPE]);
 222         named_distribute(net, &head, dnode,
 223                          &tn->nametbl->publ_list[TIPC_ZONE_SCOPE]);
 224         rcu_read_unlock();
 225
 226         tipc_link_xmit(net, &head, dnode, dnode);
 227 }
 228
 229 static void tipc_publ_subscribe(struct net *net, struct publication *publ,
 230                                 u32 addr)
 231 {
 232         struct tipc_node *node;
 233
 234         if (in_own_node(net, addr))
 235                 return;
 236
 237         node = tipc_node_find(net, addr);
 238         if (!node) {
 239                 pr_warn("Node subscription rejected, unknown node 0x%x\n",
 240                         addr);
 241                 return;
 242         }
 243
 244         tipc_node_lock(node);
 245         list_add_tail(&publ->nodesub_list, &node->publ_list);
 246         tipc_node_unlock(node);
 247 }
 248
 249 static void tipc_publ_unsubscribe(struct net *net, struct publication *publ,
 250                                   u32 addr)
 251 {
 252         struct tipc_node *node;
 253
 254         node = tipc_node_find(net, addr);
 255         if (!node)
 256                 return;
 257
 258         tipc_node_lock(node);
 259         list_del_init(&publ->nodesub_list);
 260         tipc_node_unlock(node);
 261 }
 262
 263 /**
 264  * tipc_publ_purge - remove publication associated with a failed node
 265  *
 266  * Invoked for each publication issued by a newly failed node.
 267  * Removes publication structure from name table & deletes it.
 268  */
 269 static void tipc_publ_purge(struct net *net, struct publication *publ, u32 addr)
 270 {
 271         struct tipc_net *tn = net_generic(net, tipc_net_id);
 272         struct publication *p;
 273
 274         spin_lock_bh(&tn->nametbl_lock);
 275         p = tipc_nametbl_remove_publ(net, publ->type, publ->lower,
 276                                      publ->node, publ->ref, publ->key);
 277         if (p)
 278                 tipc_publ_unsubscribe(net, p, addr);
 279         spin_unlock_bh(&tn->nametbl_lock);
 280
 281         if (p != publ) {
 282                 pr_err("Unable to remove publication from failed node\n"
 283                        " (type=%u, lower=%u, node=0x%x, ref=%u, key=%u)\n",
 284                        publ->type, publ->lower, publ->node, publ->ref,
 285                        publ->key);
 286         }
 287
 288         kfree_rcu(p, rcu);
 289 }
 290
 291 void tipc_publ_notify(struct net *net, struct list_head *nsub_list, u32 addr)
 292 {
 293         struct publication *publ, *tmp;
 294
 295         list_for_each_entry_safe(publ, tmp, nsub_list, nodesub_list)
 296                 tipc_publ_purge(net, publ, addr);
 297 }
 298
 299 /**
 300  * tipc_update_nametbl - try to process a nametable update and notify
 301  *                       subscribers
 302  *
 303  * tipc_nametbl_lock must be held.
 304  * Returns the publication item if successful, otherwise NULL.
 305  */
 306 static bool tipc_update_nametbl(struct net *net, struct distr_item *i,
 307                                 u32 node, u32 dtype)
 308 {
 309         struct publication *publ = NULL;
 310
 311         if (dtype == PUBLICATION) {
 312                 publ = tipc_nametbl_insert_publ(net, ntohl(i->type),
 313                                                 ntohl(i->lower),
 314                                                 ntohl(i->upper),
 315                                                 TIPC_CLUSTER_SCOPE, node,
 316                                                 ntohl(i->ref), ntohl(i->key));
 317                 if (publ) {
 318                         tipc_publ_subscribe(net, publ, node);
 319                         return true;
 320                 }
 321         } else if (dtype == WITHDRAWAL) {
 322                 publ = tipc_nametbl_remove_publ(net, ntohl(i->type),
 323                                                 ntohl(i->lower),
 324                                                 node, ntohl(i->ref),
 325                                                 ntohl(i->key));
 326                 if (publ) {
 327                         tipc_publ_unsubscribe(net, publ, node);
 328                         kfree_rcu(publ, rcu);
 329                         return true;
 330                 }
 331         } else {
 332                 pr_warn("Unrecognized name table message received\n");
 333         }
 334         return false;
 335 }
 336
 337 /**
 338  * tipc_named_add_backlog - add a failed name table update to the backlog
 339  *
 340  */
 341 static void tipc_named_add_backlog(struct distr_item *i, u32 type, u32 node)
 342 {
 343         struct distr_queue_item *e;
 344         unsigned long now = get_jiffies_64();
 345
 346         e = kzalloc(sizeof(*e), GFP_ATOMIC);
 347         if (!e)
 348                 return;
 349         e->dtype = type;
 350         e->node = node;
 351         e->expires = now + msecs_to_jiffies(sysctl_tipc_named_timeout);
 352         memcpy(e, i, sizeof(*i));
 353         list_add_tail(&e->next, &tipc_dist_queue);
 354 }
 355
 356 /**
 357  * tipc_named_process_backlog - try to process any pending name table updates
 358  * from the network.
 359  */
 360 void tipc_named_process_backlog(struct net *net)
 361 {
 362         struct distr_queue_item *e, *tmp;
 363         char addr[16];
 364         unsigned long now = get_jiffies_64();
 365
 366         list_for_each_entry_safe(e, tmp, &tipc_dist_queue, next) {
 367                 if (time_after(e->expires, now)) {
 368                         if (!tipc_update_nametbl(net, &e->i, e->node, e->dtype))
 369                                 continue;
 370                 } else {
 371                         tipc_addr_string_fill(addr, e->node);
 372                         pr_warn_ratelimited("Dropping name table update (%d) of {%u, %u, %u} from %s key=%u\n",
 373                                             e->dtype, ntohl(e->i.type),
 374                                             ntohl(e->i.lower),
 375                                             ntohl(e->i.upper),
 376                                             addr, ntohl(e->i.key));
 377                 }
 378                 list_del(&e->next);
 379                 kfree(e);
 380         }
 381 }
 382
 383 /**
 384  * tipc_named_rcv - process name table update messages sent by another node
 385  */
 386 void tipc_named_rcv(struct net *net, struct sk_buff_head *inputq)
 387 {
 388         struct tipc_net *tn = net_generic(net, tipc_net_id);
 389         struct tipc_msg *msg;
 390         struct distr_item *item;
 391         uint count;
 392         u32 node;
 393         struct sk_buff *skb;
 394         int mtype;
 395
 396         spin_lock_bh(&tn->nametbl_lock);
 397         for (skb = skb_dequeue(inputq); skb; skb = skb_dequeue(inputq)) {
 398                 msg = buf_msg(skb);
 399                 mtype = msg_type(msg);
 400                 item = (struct distr_item *)msg_data(msg);
 401                 count = msg_data_sz(msg) / ITEM_SIZE;
 402                 node = msg_orignode(msg);
 403                 while (count--) {
 404                         if (!tipc_update_nametbl(net, item, node, mtype))
 405                                 tipc_named_add_backlog(item, mtype, node);
 406                         item++;
 407                 }
 408                 kfree_skb(skb);
 409                 tipc_named_process_backlog(net);
 410         }
 411         spin_unlock_bh(&tn->nametbl_lock);
 412 }
 413
 414 /**
 415  * tipc_named_reinit - re-initialize local publications
 416  *
 417  * This routine is called whenever TIPC networking is enabled.
 418  * All name table entries published by this node are updated to reflect
 419  * the node's new network address.
 420  */
 421 void tipc_named_reinit(struct net *net)
 422 {
 423         struct tipc_net *tn = net_generic(net, tipc_net_id);
 424         struct publication *publ;
 425         int scope;
 426
 427         spin_lock_bh(&tn->nametbl_lock);
 428
 429         for (scope = TIPC_ZONE_SCOPE; scope <= TIPC_NODE_SCOPE; scope++)
 430                 list_for_each_entry_rcu(publ, &tn->nametbl->publ_list[scope],
 431                                         local_list)
 432                         publ->node = tn->own_addr;
 433
 434         spin_unlock_bh(&tn->nametbl_lock);
 435 }