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  * 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 tipc_net *tn = net_generic(net, tipc_net_id);
  72         struct sk_buff *buf = tipc_buf_acquire(INT_H_SIZE + size);
  73         struct tipc_msg *msg;
  74
  75         if (buf != NULL) {
  76                 msg = buf_msg(buf);
  77                 tipc_msg_init(tn->own_addr, msg, NAME_DISTRIBUTOR, type,
  78                               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 tipc_net *tn = net_generic(net, tipc_net_id);
  90         struct sk_buff *buf;
  91         struct distr_item *item;
  92
  93         list_add_tail_rcu(&publ->local_list,
  94                           &tn->nametbl->publ_list[publ->scope]);
  95
  96         if (publ->scope == TIPC_NODE_SCOPE)
  97                 return NULL;
  98
  99         buf = named_prepare_buf(net, PUBLICATION, ITEM_SIZE, 0);
 100         if (!buf) {
 101                 pr_warn("Publication distribution failure\n");
 102                 return NULL;
 103         }
 104
 105         item = (struct distr_item *)msg_data(buf_msg(buf));
 106         publ_to_item(item, publ);
 107         return buf;
 108 }
 109
 110 /**
 111  * tipc_named_withdraw - tell other nodes about a withdrawn publication by this node
 112  */
 113 struct sk_buff *tipc_named_withdraw(struct net *net, struct publication *publ)
 114 {
 115         struct sk_buff *buf;
 116         struct distr_item *item;
 117
 118         list_del(&publ->local_list);
 119
 120         if (publ->scope == TIPC_NODE_SCOPE)
 121                 return NULL;
 122
 123         buf = named_prepare_buf(net, WITHDRAWAL, ITEM_SIZE, 0);
 124         if (!buf) {
 125                 pr_warn("Withdrawal distribution failure\n");
 126                 return NULL;
 127         }
 128
 129         item = (struct distr_item *)msg_data(buf_msg(buf));
 130         publ_to_item(item, publ);
 131         return buf;
 132 }
 133
 134 /**
 135  * named_distribute - prepare name info for bulk distribution to another node
 136  * @list: list of messages (buffers) to be returned from this function
 137  * @dnode: node to be updated
 138  * @pls: linked list of publication items to be packed into buffer chain
 139  */
 140 static void named_distribute(struct net *net, struct sk_buff_head *list,
 141                              u32 dnode, struct list_head *pls)
 142 {
 143         struct publication *publ;
 144         struct sk_buff *skb = NULL;
 145         struct distr_item *item = NULL;
 146         u32 msg_dsz = ((tipc_node_get_mtu(net, dnode, 0) - INT_H_SIZE) /
 147                         ITEM_SIZE) * ITEM_SIZE;
 148         u32 msg_rem = msg_dsz;
 149
 150         list_for_each_entry(publ, pls, local_list) {
 151                 /* Prepare next buffer: */
 152                 if (!skb) {
 153                         skb = named_prepare_buf(net, PUBLICATION, msg_rem,
 154                                                 dnode);
 155                         if (!skb) {
 156                                 pr_warn("Bulk publication failure\n");
 157                                 return;
 158                         }
 159                         item = (struct distr_item *)msg_data(buf_msg(skb));
 160                 }
 161
 162                 /* Pack publication into message: */
 163                 publ_to_item(item, publ);
 164                 item++;
 165                 msg_rem -= ITEM_SIZE;
 166
 167                 /* Append full buffer to list: */
 168                 if (!msg_rem) {
 169                         __skb_queue_tail(list, skb);
 170                         skb = NULL;
 171                         msg_rem = msg_dsz;
 172                 }
 173         }
 174         if (skb) {
 175                 msg_set_size(buf_msg(skb), INT_H_SIZE + (msg_dsz - msg_rem));
 176                 skb_trim(skb, INT_H_SIZE + (msg_dsz - msg_rem));
 177                 __skb_queue_tail(list, skb);
 178         }
 179 }
 180
 181 /**
 182  * tipc_named_node_up - tell specified node about all publications by this node
 183  */
 184 void tipc_named_node_up(struct net *net, u32 dnode)
 185 {
 186         struct tipc_net *tn = net_generic(net, tipc_net_id);
 187         struct sk_buff_head head;
 188
 189         __skb_queue_head_init(&head);
 190
 191         rcu_read_lock();
 192         named_distribute(net, &head, dnode,
 193                          &tn->nametbl->publ_list[TIPC_CLUSTER_SCOPE]);
 194         named_distribute(net, &head, dnode,
 195                          &tn->nametbl->publ_list[TIPC_ZONE_SCOPE]);
 196         rcu_read_unlock();
 197
 198         tipc_node_xmit(net, &head, dnode, 0);
 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 = net_generic(net, tipc_net_id);
 210         struct publication *p;
 211
 212         spin_lock_bh(&tn->nametbl_lock);
 213         p = tipc_nametbl_remove_publ(net, publ->type, publ->lower,
 214                                      publ->node, publ->ref, publ->key);
 215         if (p)
 216                 tipc_node_unsubscribe(net, &p->nodesub_list, 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, ref=%u, key=%u)\n",
 222                        publ->type, publ->lower, publ->node, publ->ref,
 223                        publ->key);
 224         }
 225
 226         kfree_rcu(p, rcu);
 227 }
 228
 229 /**
 230  * tipc_dist_queue_purge - remove deferred updates from a node that went down
 231  */
 232 static void tipc_dist_queue_purge(struct net *net, u32 addr)
 233 {
 234         struct tipc_net *tn = net_generic(net, tipc_net_id);
 235         struct distr_queue_item *e, *tmp;
 236
 237         spin_lock_bh(&tn->nametbl_lock);
 238         list_for_each_entry_safe(e, tmp, &tn->dist_queue, next) {
 239                 if (e->node != addr)
 240                         continue;
 241                 list_del(&e->next);
 242                 kfree(e);
 243         }
 244         spin_unlock_bh(&tn->nametbl_lock);
 245 }
 246
 247 void tipc_publ_notify(struct net *net, struct list_head *nsub_list, u32 addr)
 248 {
 249         struct publication *publ, *tmp;
 250
 251         list_for_each_entry_safe(publ, tmp, nsub_list, nodesub_list)
 252                 tipc_publ_purge(net, publ, addr);
 253         tipc_dist_queue_purge(net, addr);
 254 }
 255
 256 /**
 257  * tipc_update_nametbl - try to process a nametable update and notify
 258  *                       subscribers
 259  *
 260  * tipc_nametbl_lock must be held.
 261  * Returns the publication item if successful, otherwise NULL.
 262  */
 263 static bool tipc_update_nametbl(struct net *net, struct distr_item *i,
 264                                 u32 node, u32 dtype)
 265 {
 266         struct publication *publ = NULL;
 267
 268         if (dtype == PUBLICATION) {
 269                 publ = tipc_nametbl_insert_publ(net, ntohl(i->type),
 270                                                 ntohl(i->lower),
 271                                                 ntohl(i->upper),
 272                                                 TIPC_CLUSTER_SCOPE, node,
 273                                                 ntohl(i->ref), ntohl(i->key));
 274                 if (publ) {
 275                         tipc_node_subscribe(net, &publ->nodesub_list, node);
 276                         return true;
 277                 }
 278         } else if (dtype == WITHDRAWAL) {
 279                 publ = tipc_nametbl_remove_publ(net, ntohl(i->type),
 280                                                 ntohl(i->lower),
 281                                                 node, ntohl(i->ref),
 282                                                 ntohl(i->key));
 283                 if (publ) {
 284                         tipc_node_unsubscribe(net, &publ->nodesub_list, node);
 285                         kfree_rcu(publ, rcu);
 286                         return true;
 287                 }
 288         } else {
 289                 pr_warn("Unrecognized name table message received\n");
 290         }
 291         return false;
 292 }
 293
 294 /**
 295  * tipc_named_add_backlog - add a failed name table update to the backlog
 296  *
 297  */
 298 static void tipc_named_add_backlog(struct net *net, struct distr_item *i,
 299                                    u32 type, u32 node)
 300 {
 301         struct distr_queue_item *e;
 302         struct tipc_net *tn = net_generic(net, tipc_net_id);
 303         unsigned long now = get_jiffies_64();
 304
 305         e = kzalloc(sizeof(*e), GFP_ATOMIC);
 306         if (!e)
 307                 return;
 308         e->dtype = type;
 309         e->node = node;
 310         e->expires = now + msecs_to_jiffies(sysctl_tipc_named_timeout);
 311         memcpy(e, i, sizeof(*i));
 312         list_add_tail(&e->next, &tn->dist_queue);
 313 }
 314
 315 /**
 316  * tipc_named_process_backlog - try to process any pending name table updates
 317  * from the network.
 318  */
 319 void tipc_named_process_backlog(struct net *net)
 320 {
 321         struct distr_queue_item *e, *tmp;
 322         struct tipc_net *tn = net_generic(net, tipc_net_id);
 323         char addr[16];
 324         unsigned long now = get_jiffies_64();
 325
 326         list_for_each_entry_safe(e, tmp, &tn->dist_queue, next) {
 327                 if (time_after(e->expires, now)) {
 328                         if (!tipc_update_nametbl(net, &e->i, e->node, e->dtype))
 329                                 continue;
 330                 } else {
 331                         tipc_addr_string_fill(addr, e->node);
 332                         pr_warn_ratelimited("Dropping name table update (%d) of {%u, %u, %u} from %s key=%u\n",
 333                                             e->dtype, ntohl(e->i.type),
 334                                             ntohl(e->i.lower),
 335                                             ntohl(e->i.upper),
 336                                             addr, ntohl(e->i.key));
 337                 }
 338                 list_del(&e->next);
 339                 kfree(e);
 340         }
 341 }
 342
 343 /**
 344  * tipc_named_rcv - process name table update messages sent by another node
 345  */
 346 void tipc_named_rcv(struct net *net, struct sk_buff_head *inputq)
 347 {
 348         struct tipc_net *tn = net_generic(net, tipc_net_id);
 349         struct tipc_msg *msg;
 350         struct distr_item *item;
 351         uint count;
 352         u32 node;
 353         struct sk_buff *skb;
 354         int mtype;
 355
 356         spin_lock_bh(&tn->nametbl_lock);
 357         for (skb = skb_dequeue(inputq); skb; skb = skb_dequeue(inputq)) {
 358                 skb_linearize(skb);
 359                 msg = buf_msg(skb);
 360                 mtype = msg_type(msg);
 361                 item = (struct distr_item *)msg_data(msg);
 362                 count = msg_data_sz(msg) / ITEM_SIZE;
 363                 node = msg_orignode(msg);
 364                 while (count--) {
 365                         if (!tipc_update_nametbl(net, item, node, mtype))
 366                                 tipc_named_add_backlog(net, item, mtype, node);
 367                         item++;
 368                 }
 369                 kfree_skb(skb);
 370                 tipc_named_process_backlog(net);
 371         }
 372         spin_unlock_bh(&tn->nametbl_lock);
 373 }
 374
 375 /**
 376  * tipc_named_reinit - re-initialize local publications
 377  *
 378  * This routine is called whenever TIPC networking is enabled.
 379  * All name table entries published by this node are updated to reflect
 380  * the node's new network address.
 381  */
 382 void tipc_named_reinit(struct net *net)
 383 {
 384         struct tipc_net *tn = net_generic(net, tipc_net_id);
 385         struct publication *publ;
 386         int scope;
 387
 388         spin_lock_bh(&tn->nametbl_lock);
 389
 390         for (scope = TIPC_ZONE_SCOPE; scope <= TIPC_NODE_SCOPE; scope++)
 391                 list_for_each_entry_rcu(publ, &tn->nametbl->publ_list[scope],
 392                                         local_list)
 393                         publ->node = tn->own_addr;
 394
 395         spin_unlock_bh(&tn->nametbl_lock);
 396 }