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 /**
  42  * struct publ_list - list of publications made by this node
  43  * @list: circular list of publications
  44  * @list_size: number of entries in list
  45  */
  46 struct publ_list {
  47         struct list_head list;
  48         u32 size;
  49 };
  50
  51 static struct publ_list publ_zone = {
  52         .list = LIST_HEAD_INIT(publ_zone.list),
  53         .size = 0,
  54 };
  55
  56 static struct publ_list publ_cluster = {
  57         .list = LIST_HEAD_INIT(publ_cluster.list),
  58         .size = 0,
  59 };
  60
  61 static struct publ_list publ_node = {
  62         .list = LIST_HEAD_INIT(publ_node.list),
  63         .size = 0,
  64 };
  65
  66 static struct publ_list *publ_lists[] = {
  67         NULL,
  68         &publ_zone,     /* publ_lists[TIPC_ZONE_SCOPE]          */
  69         &publ_cluster,  /* publ_lists[TIPC_CLUSTER_SCOPE]       */
  70         &publ_node      /* publ_lists[TIPC_NODE_SCOPE]          */
  71 };
  72
  73
  74 int sysctl_tipc_named_timeout __read_mostly = 2000;
  75
  76 /**
  77  * struct tipc_dist_queue - queue holding deferred name table updates
  78  */
  79 static struct list_head tipc_dist_queue = LIST_HEAD_INIT(tipc_dist_queue);
  80
  81 struct distr_queue_item {
  82         struct distr_item i;
  83         u32 dtype;
  84         u32 node;
  85         unsigned long expires;
  86         struct list_head next;
  87 };
  88
  89 /**
  90  * publ_to_item - add publication info to a publication message
  91  */
  92 static void publ_to_item(struct distr_item *i, struct publication *p)
  93 {
  94         i->type = htonl(p->type);
  95         i->lower = htonl(p->lower);
  96         i->upper = htonl(p->upper);
  97         i->ref = htonl(p->ref);
  98         i->key = htonl(p->key);
  99 }
 100
 101 /**
 102  * named_prepare_buf - allocate & initialize a publication message
 103  */
 104 static struct sk_buff *named_prepare_buf(u32 type, u32 size, u32 dest)
 105 {
 106         struct sk_buff *buf = tipc_buf_acquire(INT_H_SIZE + size);
 107         struct tipc_msg *msg;
 108
 109         if (buf != NULL) {
 110                 msg = buf_msg(buf);
 111                 tipc_msg_init(msg, NAME_DISTRIBUTOR, type, INT_H_SIZE, dest);
 112                 msg_set_size(msg, INT_H_SIZE + size);
 113         }
 114         return buf;
 115 }
 116
 117 void named_cluster_distribute(struct sk_buff *buf)
 118 {
 119         struct sk_buff *obuf;
 120         struct tipc_node *node;
 121         u32 dnode;
 122
 123         rcu_read_lock();
 124         list_for_each_entry_rcu(node, &tipc_node_list, list) {
 125                 dnode = node->addr;
 126                 if (in_own_node(dnode))
 127                         continue;
 128                 if (!tipc_node_active_links(node))
 129                         continue;
 130                 obuf = skb_copy(buf, GFP_ATOMIC);
 131                 if (!obuf)
 132                         break;
 133                 msg_set_destnode(buf_msg(obuf), dnode);
 134                 tipc_link_xmit(obuf, dnode, dnode);
 135         }
 136         rcu_read_unlock();
 137
 138         kfree_skb(buf);
 139 }
 140
 141 /**
 142  * tipc_named_publish - tell other nodes about a new publication by this node
 143  */
 144 struct sk_buff *tipc_named_publish(struct publication *publ)
 145 {
 146         struct sk_buff *buf;
 147         struct distr_item *item;
 148
 149         list_add_tail(&publ->local_list, &publ_lists[publ->scope]->list);
 150         publ_lists[publ->scope]->size++;
 151
 152         if (publ->scope == TIPC_NODE_SCOPE)
 153                 return NULL;
 154
 155         buf = named_prepare_buf(PUBLICATION, ITEM_SIZE, 0);
 156         if (!buf) {
 157                 pr_warn("Publication distribution failure\n");
 158                 return NULL;
 159         }
 160
 161         item = (struct distr_item *)msg_data(buf_msg(buf));
 162         publ_to_item(item, publ);
 163         return buf;
 164 }
 165
 166 /**
 167  * tipc_named_withdraw - tell other nodes about a withdrawn publication by this node
 168  */
 169 struct sk_buff *tipc_named_withdraw(struct publication *publ)
 170 {
 171         struct sk_buff *buf;
 172         struct distr_item *item;
 173
 174         list_del(&publ->local_list);
 175         publ_lists[publ->scope]->size--;
 176
 177         if (publ->scope == TIPC_NODE_SCOPE)
 178                 return NULL;
 179
 180         buf = named_prepare_buf(WITHDRAWAL, ITEM_SIZE, 0);
 181         if (!buf) {
 182                 pr_warn("Withdrawal distribution failure\n");
 183                 return NULL;
 184         }
 185
 186         item = (struct distr_item *)msg_data(buf_msg(buf));
 187         publ_to_item(item, publ);
 188         return buf;
 189 }
 190
 191 /**
 192  * named_distribute - prepare name info for bulk distribution to another node
 193  * @msg_list: list of messages (buffers) to be returned from this function
 194  * @dnode: node to be updated
 195  * @pls: linked list of publication items to be packed into buffer chain
 196  */
 197 static void named_distribute(struct list_head *msg_list, u32 dnode,
 198                              struct publ_list *pls)
 199 {
 200         struct publication *publ;
 201         struct sk_buff *buf = NULL;
 202         struct distr_item *item = NULL;
 203         uint dsz = pls->size * ITEM_SIZE;
 204         uint msg_dsz = (tipc_node_get_mtu(dnode, 0) / ITEM_SIZE) * ITEM_SIZE;
 205         uint rem = dsz;
 206         uint msg_rem = 0;
 207
 208         list_for_each_entry(publ, &pls->list, local_list) {
 209                 /* Prepare next buffer: */
 210                 if (!buf) {
 211                         msg_rem = min_t(uint, rem, msg_dsz);
 212                         rem -= msg_rem;
 213                         buf = named_prepare_buf(PUBLICATION, msg_rem, dnode);
 214                         if (!buf) {
 215                                 pr_warn("Bulk publication failure\n");
 216                                 return;
 217                         }
 218                         item = (struct distr_item *)msg_data(buf_msg(buf));
 219                 }
 220
 221                 /* Pack publication into message: */
 222                 publ_to_item(item, publ);
 223                 item++;
 224                 msg_rem -= ITEM_SIZE;
 225
 226                 /* Append full buffer to list: */
 227                 if (!msg_rem) {
 228                         list_add_tail((struct list_head *)buf, msg_list);
 229                         buf = NULL;
 230                 }
 231         }
 232 }
 233
 234 /**
 235  * tipc_named_node_up - tell specified node about all publications by this node
 236  */
 237 void tipc_named_node_up(u32 dnode)
 238 {
 239         LIST_HEAD(msg_list);
 240         struct sk_buff *buf_chain;
 241
 242         read_lock_bh(&tipc_nametbl_lock);
 243         named_distribute(&msg_list, dnode, &publ_cluster);
 244         named_distribute(&msg_list, dnode, &publ_zone);
 245         read_unlock_bh(&tipc_nametbl_lock);
 246
 247         /* Convert circular list to linear list and send: */
 248         buf_chain = (struct sk_buff *)msg_list.next;
 249         ((struct sk_buff *)msg_list.prev)->next = NULL;
 250         tipc_link_xmit(buf_chain, dnode, dnode);
 251 }
 252
 253 /**
 254  * named_purge_publ - remove publication associated with a failed node
 255  *
 256  * Invoked for each publication issued by a newly failed node.
 257  * Removes publication structure from name table & deletes it.
 258  */
 259 static void named_purge_publ(struct publication *publ)
 260 {
 261         struct publication *p;
 262
 263         write_lock_bh(&tipc_nametbl_lock);
 264         p = tipc_nametbl_remove_publ(publ->type, publ->lower,
 265                                      publ->node, publ->ref, publ->key);
 266         if (p)
 267                 tipc_nodesub_unsubscribe(&p->subscr);
 268         write_unlock_bh(&tipc_nametbl_lock);
 269
 270         if (p != publ) {
 271                 pr_err("Unable to remove publication from failed node\n"
 272                        " (type=%u, lower=%u, node=0x%x, ref=%u, key=%u)\n",
 273                        publ->type, publ->lower, publ->node, publ->ref,
 274                        publ->key);
 275         }
 276
 277         kfree(p);
 278 }
 279
 280 /**
 281  * tipc_update_nametbl - try to process a nametable update and notify
 282  *                       subscribers
 283  *
 284  * tipc_nametbl_lock must be held.
 285  * Returns the publication item if successful, otherwise NULL.
 286  */
 287 static bool tipc_update_nametbl(struct distr_item *i, u32 node, u32 dtype)
 288 {
 289         struct publication *publ = NULL;
 290
 291         if (dtype == PUBLICATION) {
 292                 publ = tipc_nametbl_insert_publ(ntohl(i->type), ntohl(i->lower),
 293                                                 ntohl(i->upper),
 294                                                 TIPC_CLUSTER_SCOPE, node,
 295                                                 ntohl(i->ref), ntohl(i->key));
 296                 if (publ) {
 297                         tipc_nodesub_subscribe(&publ->subscr, node, publ,
 298                                                (net_ev_handler)
 299                                                named_purge_publ);
 300                         return true;
 301                 }
 302         } else if (dtype == WITHDRAWAL) {
 303                 publ = tipc_nametbl_remove_publ(ntohl(i->type), ntohl(i->lower),
 304                                                 node, ntohl(i->ref),
 305                                                 ntohl(i->key));
 306                 if (publ) {
 307                         tipc_nodesub_unsubscribe(&publ->subscr);
 308                         kfree(publ);
 309                         return true;
 310                 }
 311         } else {
 312                 pr_warn("Unrecognized name table message received\n");
 313         }
 314         return false;
 315 }
 316
 317 /**
 318  * tipc_named_add_backlog - add a failed name table update to the backlog
 319  *
 320  */
 321 static void tipc_named_add_backlog(struct distr_item *i, u32 type, u32 node)
 322 {
 323         struct distr_queue_item *e;
 324         unsigned long now = get_jiffies_64();
 325
 326         e = kzalloc(sizeof(*e), GFP_ATOMIC);
 327         if (!e)
 328                 return;
 329         e->dtype = type;
 330         e->node = node;
 331         e->expires = now + msecs_to_jiffies(sysctl_tipc_named_timeout);
 332         memcpy(e, i, sizeof(*i));
 333         list_add_tail(&e->next, &tipc_dist_queue);
 334 }
 335
 336 /**
 337  * tipc_named_process_backlog - try to process any pending name table updates
 338  * from the network.
 339  */
 340 void tipc_named_process_backlog(void)
 341 {
 342         struct distr_queue_item *e, *tmp;
 343         char addr[16];
 344         unsigned long now = get_jiffies_64();
 345
 346         list_for_each_entry_safe(e, tmp, &tipc_dist_queue, next) {
 347                 if (time_after(e->expires, now)) {
 348                         if (!tipc_update_nametbl(&e->i, e->node, e->dtype))
 349                                 continue;
 350                 } else {
 351                         tipc_addr_string_fill(addr, e->node);
 352                         pr_warn_ratelimited("Dropping name table update (%d) of {%u, %u, %u} from %s key=%u\n",
 353                                             e->dtype, ntohl(e->i.type),
 354                                             ntohl(e->i.lower),
 355                                             ntohl(e->i.upper),
 356                                             addr, ntohl(e->i.key));
 357                 }
 358                 list_del(&e->next);
 359                 kfree(e);
 360         }
 361 }
 362
 363 /**
 364  * tipc_named_rcv - process name table update message sent by another node
 365  */
 366 void tipc_named_rcv(struct sk_buff *buf)
 367 {
 368         struct tipc_msg *msg = buf_msg(buf);
 369         struct distr_item *item = (struct distr_item *)msg_data(msg);
 370         u32 count = msg_data_sz(msg) / ITEM_SIZE;
 371         u32 node = msg_orignode(msg);
 372
 373         write_lock_bh(&tipc_nametbl_lock);
 374         while (count--) {
 375                 if (!tipc_update_nametbl(item, node, msg_type(msg)))
 376                         tipc_named_add_backlog(item, msg_type(msg), node);
 377                 item++;
 378         }
 379         tipc_named_process_backlog();
 380         write_unlock_bh(&tipc_nametbl_lock);
 381         kfree_skb(buf);
 382 }
 383
 384 /**
 385  * tipc_named_reinit - re-initialize local publications
 386  *
 387  * This routine is called whenever TIPC networking is enabled.
 388  * All name table entries published by this node are updated to reflect
 389  * the node's new network address.
 390  */
 391 void tipc_named_reinit(void)
 392 {
 393         struct publication *publ;
 394         int scope;
 395
 396         write_lock_bh(&tipc_nametbl_lock);
 397
 398         for (scope = TIPC_ZONE_SCOPE; scope <= TIPC_NODE_SCOPE; scope++)
 399                 list_for_each_entry(publ, &publ_lists[scope]->list, local_list)
 400                         publ->node = tipc_own_addr;
 401
 402         write_unlock_bh(&tipc_nametbl_lock);
 403 }