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 109  * tipc_named_withdraw - tell other nodes about a withdrawn publication by this node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