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 /**
  88  * tipc_named_publish - tell other nodes about a new publication by this node
  89  */
  90 struct sk_buff *tipc_named_publish(struct net *net, struct publication *publ)
  91 {
  92         struct tipc_net *tn = net_generic(net, tipc_net_id);
  93         struct sk_buff *buf;
  94         struct distr_item *item;
  95
  96         list_add_tail_rcu(&publ->local_list,
  97                           &tn->nametbl->publ_list[publ->scope]);
  98
  99         if (publ->scope == TIPC_NODE_SCOPE)
 100                 return NULL;
 101
 102         buf = named_prepare_buf(net, PUBLICATION, ITEM_SIZE, 0);
 103         if (!buf) {
 104                 pr_warn("Publication distribution failure\n");
 105                 return NULL;
 106         }
 107
 108         item = (struct distr_item *)msg_data(buf_msg(buf));
 109         publ_to_item(item, publ);
 110         return buf;
 111 }
 112
 113 /**
 114  * tipc_named_withdraw - tell other nodes about a withdrawn publication by this node
 115  */
 116 struct sk_buff *tipc_named_withdraw(struct net *net, struct publication *publ)
 117 {
 118         struct sk_buff *buf;
 119         struct distr_item *item;
 120
 121         list_del(&publ->local_list);
 122
 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         uint msg_dsz = (tipc_node_get_mtu(net, dnode, 0) / ITEM_SIZE) *
 150                         ITEM_SIZE;
 151         uint msg_rem = msg_dsz;
 152
 153         list_for_each_entry(publ, pls, local_list) {
 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                         item = (struct distr_item *)msg_data(buf_msg(skb));
 163                 }
 164
 165                 /* Pack publication into message: */
 166                 publ_to_item(item, publ);
 167                 item++;
 168                 msg_rem -= ITEM_SIZE;
 169
 170                 /* Append full buffer to list: */
 171                 if (!msg_rem) {
 172                         __skb_queue_tail(list, skb);
 173                         skb = NULL;
 174                         msg_rem = msg_dsz;
 175                 }
 176         }
 177         if (skb) {
 178                 msg_set_size(buf_msg(skb), INT_H_SIZE + (msg_dsz - msg_rem));
 179                 skb_trim(skb, INT_H_SIZE + (msg_dsz - msg_rem));
 180                 __skb_queue_tail(list, skb);
 181         }
 182 }
 183
 184 /**
 185  * tipc_named_node_up - tell specified node about all publications by this node
 186  */
 187 void tipc_named_node_up(struct net *net, u32 dnode)
 188 {
 189         struct tipc_net *tn = net_generic(net, tipc_net_id);
 190         struct sk_buff_head head;
 191
 192         __skb_queue_head_init(&head);
 193
 194         rcu_read_lock();
 195         named_distribute(net, &head, dnode,
 196                          &tn->nametbl->publ_list[TIPC_CLUSTER_SCOPE]);
 197         named_distribute(net, &head, dnode,
 198                          &tn->nametbl->publ_list[TIPC_ZONE_SCOPE]);
 199         rcu_read_unlock();
 200
 201         tipc_node_xmit(net, &head, dnode, 0);
 202 }
 203
 204 /**
 205  * tipc_publ_purge - remove publication associated with a failed node
 206  *
 207  * Invoked for each publication issued by a newly failed node.
 208  * Removes publication structure from name table & deletes it.
 209  */
 210 static void tipc_publ_purge(struct net *net, struct publication *publ, u32 addr)
 211 {
 212         struct tipc_net *tn = net_generic(net, tipc_net_id);
 213         struct publication *p;
 214
 215         spin_lock_bh(&tn->nametbl_lock);
 216         p = tipc_nametbl_remove_publ(net, publ->type, publ->lower,
 217                                      publ->node, publ->ref, publ->key);
 218         if (p)
 219                 tipc_node_unsubscribe(net, &p->nodesub_list, addr);
 220         spin_unlock_bh(&tn->nametbl_lock);
 221
 222         if (p != publ) {
 223                 pr_err("Unable to remove publication from failed node\n"
 224                        " (type=%u, lower=%u, node=0x%x, ref=%u, key=%u)\n",
 225                        publ->type, publ->lower, publ->node, publ->ref,
 226                        publ->key);
 227         }
 228
 229         kfree_rcu(p, rcu);
 230 }
 231
 232 void tipc_publ_notify(struct net *net, struct list_head *nsub_list, u32 addr)
 233 {
 234         struct publication *publ, *tmp;
 235
 236         list_for_each_entry_safe(publ, tmp, nsub_list, nodesub_list)
 237                 tipc_publ_purge(net, publ, addr);
 238 }
 239
 240 /**
 241  * tipc_update_nametbl - try to process a nametable update and notify
 242  *                       subscribers
 243  *
 244  * tipc_nametbl_lock must be held.
 245  * Returns the publication item if successful, otherwise NULL.
 246  */
 247 static bool tipc_update_nametbl(struct net *net, struct distr_item *i,
 248                                 u32 node, u32 dtype)
 249 {
 250         struct publication *publ = NULL;
 251
 252         if (dtype == PUBLICATION) {
 253                 publ = tipc_nametbl_insert_publ(net, ntohl(i->type),
 254                                                 ntohl(i->lower),
 255                                                 ntohl(i->upper),
 256                                                 TIPC_CLUSTER_SCOPE, node,
 257                                                 ntohl(i->ref), ntohl(i->key));
 258                 if (publ) {
 259                         tipc_node_subscribe(net, &publ->nodesub_list, node);
 260                         return true;
 261                 }
 262         } else if (dtype == WITHDRAWAL) {
 263                 publ = tipc_nametbl_remove_publ(net, ntohl(i->type),
 264                                                 ntohl(i->lower),
 265                                                 node, ntohl(i->ref),
 266                                                 ntohl(i->key));
 267                 if (publ) {
 268                         tipc_node_unsubscribe(net, &publ->nodesub_list, node);
 269                         kfree_rcu(publ, rcu);
 270                         return true;
 271                 }
 272         } else {
 273                 pr_warn("Unrecognized name table message received\n");
 274         }
 275         return false;
 276 }
 277
 278 /**
 279  * tipc_named_add_backlog - add a failed name table update to the backlog
 280  *
 281  */
 282 static void tipc_named_add_backlog(struct distr_item *i, u32 type, u32 node)
 283 {
 284         struct distr_queue_item *e;
 285         unsigned long now = get_jiffies_64();
 286
 287         e = kzalloc(sizeof(*e), GFP_ATOMIC);
 288         if (!e)
 289                 return;
 290         e->dtype = type;
 291         e->node = node;
 292         e->expires = now + msecs_to_jiffies(sysctl_tipc_named_timeout);
 293         memcpy(e, i, sizeof(*i));
 294         list_add_tail(&e->next, &tipc_dist_queue);
 295 }
 296
 297 /**
 298  * tipc_named_process_backlog - try to process any pending name table updates
 299  * from the network.
 300  */
 301 void tipc_named_process_backlog(struct net *net)
 302 {
 303         struct distr_queue_item *e, *tmp;
 304         char addr[16];
 305         unsigned long now = get_jiffies_64();
 306
 307         list_for_each_entry_safe(e, tmp, &tipc_dist_queue, next) {
 308                 if (time_after(e->expires, now)) {
 309                         if (!tipc_update_nametbl(net, &e->i, e->node, e->dtype))
 310                                 continue;
 311                 } else {
 312                         tipc_addr_string_fill(addr, e->node);
 313                         pr_warn_ratelimited("Dropping name table update (%d) of {%u, %u, %u} from %s key=%u\n",
 314                                             e->dtype, ntohl(e->i.type),
 315                                             ntohl(e->i.lower),
 316                                             ntohl(e->i.upper),
 317                                             addr, ntohl(e->i.key));
 318                 }
 319                 list_del(&e->next);
 320                 kfree(e);
 321         }
 322 }
 323
 324 /**
 325  * tipc_named_rcv - process name table update messages sent by another node
 326  */
 327 void tipc_named_rcv(struct net *net, struct sk_buff_head *inputq)
 328 {
 329         struct tipc_net *tn = net_generic(net, tipc_net_id);
 330         struct tipc_msg *msg;
 331         struct distr_item *item;
 332         uint count;
 333         u32 node;
 334         struct sk_buff *skb;
 335         int mtype;
 336
 337         spin_lock_bh(&tn->nametbl_lock);
 338         for (skb = skb_dequeue(inputq); skb; skb = skb_dequeue(inputq)) {
 339                 skb_linearize(skb);
 340                 msg = buf_msg(skb);
 341                 mtype = msg_type(msg);
 342                 item = (struct distr_item *)msg_data(msg);
 343                 count = msg_data_sz(msg) / ITEM_SIZE;
 344                 node = msg_orignode(msg);
 345                 while (count--) {
 346                         if (!tipc_update_nametbl(net, item, node, mtype))
 347                                 tipc_named_add_backlog(item, mtype, node);
 348                         item++;
 349                 }
 350                 kfree_skb(skb);
 351                 tipc_named_process_backlog(net);
 352         }
 353         spin_unlock_bh(&tn->nametbl_lock);
 354 }
 355
 356 /**
 357  * tipc_named_reinit - re-initialize local publications
 358  *
 359  * This routine is called whenever TIPC networking is enabled.
 360  * All name table entries published by this node are updated to reflect
 361  * the node's new network address.
 362  */
 363 void tipc_named_reinit(struct net *net)
 364 {
 365         struct tipc_net *tn = net_generic(net, tipc_net_id);
 366         struct publication *publ;
 367         int scope;
 368
 369         spin_lock_bh(&tn->nametbl_lock);
 370
 371         for (scope = TIPC_ZONE_SCOPE; scope <= TIPC_NODE_SCOPE; scope++)
 372                 list_for_each_entry_rcu(publ, &tn->nametbl->publ_list[scope],
 373                                         local_list)
 374                         publ->node = tn->own_addr;
 375
 376         spin_unlock_bh(&tn->nametbl_lock);
 377 }