net/tipc/node.c

   1 /*
   2  * net/tipc/node.c: TIPC node management routines
   3  *
   4  * Copyright (c) 2000-2006, 2012-2014, Ericsson AB
   5  * Copyright (c) 2005-2006, 2010-2014, 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 "config.h"
  39 #include "node.h"
  40 #include "name_distr.h"
  41
  42 #define NODE_HTABLE_SIZE 512
  43
  44 static void node_lost_contact(struct tipc_node *n_ptr);
  45 static void node_established_contact(struct tipc_node *n_ptr);
  46
  47 static struct hlist_head node_htable[NODE_HTABLE_SIZE];
  48 LIST_HEAD(tipc_node_list);
  49 static u32 tipc_num_nodes;
  50 static u32 tipc_num_links;
  51 static DEFINE_SPINLOCK(node_list_lock);
  52
  53 /*
  54  * A trivial power-of-two bitmask technique is used for speed, since this
  55  * operation is done for every incoming TIPC packet. The number of hash table
  56  * entries has been chosen so that no hash chain exceeds 8 nodes and will
  57  * usually be much smaller (typically only a single node).
  58  */
  59 static unsigned int tipc_hashfn(u32 addr)
  60 {
  61         return addr & (NODE_HTABLE_SIZE - 1);
  62 }
  63
  64 /*
  65  * tipc_node_find - locate specified node object, if it exists
  66  */
  67 struct tipc_node *tipc_node_find(u32 addr)
  68 {
  69         struct tipc_node *node;
  70
  71         if (unlikely(!in_own_cluster_exact(addr)))
  72                 return NULL;
  73
  74         rcu_read_lock();
  75         hlist_for_each_entry_rcu(node, &node_htable[tipc_hashfn(addr)], hash) {
  76                 if (node->addr == addr) {
  77                         rcu_read_unlock();
  78                         return node;
  79                 }
  80         }
  81         rcu_read_unlock();
  82         return NULL;
  83 }
  84
  85 struct tipc_node *tipc_node_create(u32 addr)
  86 {
  87         struct tipc_node *n_ptr, *temp_node;
  88
  89         spin_lock_bh(&node_list_lock);
  90
  91         n_ptr = kzalloc(sizeof(*n_ptr), GFP_ATOMIC);
  92         if (!n_ptr) {
  93                 spin_unlock_bh(&node_list_lock);
  94                 pr_warn("Node creation failed, no memory\n");
  95                 return NULL;
  96         }
  97
  98         n_ptr->addr = addr;
  99         spin_lock_init(&n_ptr->lock);
 100         INIT_HLIST_NODE(&n_ptr->hash);
 101         INIT_LIST_HEAD(&n_ptr->list);
 102         INIT_LIST_HEAD(&n_ptr->nsub);
 103
 104         hlist_add_head_rcu(&n_ptr->hash, &node_htable[tipc_hashfn(addr)]);
 105
 106         list_for_each_entry_rcu(temp_node, &tipc_node_list, list) {
 107                 if (n_ptr->addr < temp_node->addr)
 108                         break;
 109         }
 110         list_add_tail_rcu(&n_ptr->list, &temp_node->list);
 111         n_ptr->action_flags = TIPC_WAIT_PEER_LINKS_DOWN;
 112         n_ptr->signature = INVALID_NODE_SIG;
 113
 114         tipc_num_nodes++;
 115
 116         spin_unlock_bh(&node_list_lock);
 117         return n_ptr;
 118 }
 119
 120 static void tipc_node_delete(struct tipc_node *n_ptr)
 121 {
 122         list_del_rcu(&n_ptr->list);
 123         hlist_del_rcu(&n_ptr->hash);
 124         kfree_rcu(n_ptr, rcu);
 125
 126         tipc_num_nodes--;
 127 }
 128
 129 void tipc_node_stop(void)
 130 {
 131         struct tipc_node *node, *t_node;
 132
 133         spin_lock_bh(&node_list_lock);
 134         list_for_each_entry_safe(node, t_node, &tipc_node_list, list)
 135                 tipc_node_delete(node);
 136         spin_unlock_bh(&node_list_lock);
 137 }
 138
 139 /**
 140  * tipc_node_link_up - handle addition of link
 141  *
 142  * Link becomes active (alone or shared) or standby, depending on its priority.
 143  */
 144 void tipc_node_link_up(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
 145 {
 146         struct tipc_link **active = &n_ptr->active_links[0];
 147         u32 addr = n_ptr->addr;
 148
 149         n_ptr->working_links++;
 150         tipc_nametbl_publish(TIPC_LINK_STATE, addr, addr, TIPC_NODE_SCOPE,
 151                              l_ptr->bearer_id, addr);
 152         pr_info("Established link <%s> on network plane %c\n",
 153                 l_ptr->name, l_ptr->net_plane);
 154
 155         if (!active[0]) {
 156                 active[0] = active[1] = l_ptr;
 157                 node_established_contact(n_ptr);
 158                 goto exit;
 159         }
 160         if (l_ptr->priority < active[0]->priority) {
 161                 pr_info("New link <%s> becomes standby\n", l_ptr->name);
 162                 goto exit;
 163         }
 164         tipc_link_dup_queue_xmit(active[0], l_ptr);
 165         if (l_ptr->priority == active[0]->priority) {
 166                 active[0] = l_ptr;
 167                 goto exit;
 168         }
 169         pr_info("Old link <%s> becomes standby\n", active[0]->name);
 170         if (active[1] != active[0])
 171                 pr_info("Old link <%s> becomes standby\n", active[1]->name);
 172         active[0] = active[1] = l_ptr;
 173 exit:
 174         /* Leave room for changeover header when returning 'mtu' to users: */
 175         n_ptr->act_mtus[0] = active[0]->max_pkt - INT_H_SIZE;
 176         n_ptr->act_mtus[1] = active[1]->max_pkt - INT_H_SIZE;
 177 }
 178
 179 /**
 180  * node_select_active_links - select active link
 181  */
 182 static void node_select_active_links(struct tipc_node *n_ptr)
 183 {
 184         struct tipc_link **active = &n_ptr->active_links[0];
 185         u32 i;
 186         u32 highest_prio = 0;
 187
 188         active[0] = active[1] = NULL;
 189
 190         for (i = 0; i < MAX_BEARERS; i++) {
 191                 struct tipc_link *l_ptr = n_ptr->links[i];
 192
 193                 if (!l_ptr || !tipc_link_is_up(l_ptr) ||
 194                     (l_ptr->priority < highest_prio))
 195                         continue;
 196
 197                 if (l_ptr->priority > highest_prio) {
 198                         highest_prio = l_ptr->priority;
 199                         active[0] = active[1] = l_ptr;
 200                 } else {
 201                         active[1] = l_ptr;
 202                 }
 203         }
 204 }
 205
 206 /**
 207  * tipc_node_link_down - handle loss of link
 208  */
 209 void tipc_node_link_down(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
 210 {
 211         struct tipc_link **active;
 212         u32 addr = n_ptr->addr;
 213
 214         n_ptr->working_links--;
 215         tipc_nametbl_withdraw(TIPC_LINK_STATE, addr, l_ptr->bearer_id, addr);
 216
 217         if (!tipc_link_is_active(l_ptr)) {
 218                 pr_info("Lost standby link <%s> on network plane %c\n",
 219                         l_ptr->name, l_ptr->net_plane);
 220                 return;
 221         }
 222         pr_info("Lost link <%s> on network plane %c\n",
 223                 l_ptr->name, l_ptr->net_plane);
 224
 225         active = &n_ptr->active_links[0];
 226         if (active[0] == l_ptr)
 227                 active[0] = active[1];
 228         if (active[1] == l_ptr)
 229                 active[1] = active[0];
 230         if (active[0] == l_ptr)
 231                 node_select_active_links(n_ptr);
 232         if (tipc_node_is_up(n_ptr))
 233                 tipc_link_failover_send_queue(l_ptr);
 234         else
 235                 node_lost_contact(n_ptr);
 236
 237         /* Leave room for changeover header when returning 'mtu' to users: */
 238         if (active[0]) {
 239                 n_ptr->act_mtus[0] = active[0]->max_pkt - INT_H_SIZE;
 240                 n_ptr->act_mtus[1] = active[1]->max_pkt - INT_H_SIZE;
 241                 return;
 242         }
 243
 244         /* Loopback link went down? No fragmentation needed from now on. */
 245         if (n_ptr->addr == tipc_own_addr) {
 246                 n_ptr->act_mtus[0] = MAX_MSG_SIZE;
 247                 n_ptr->act_mtus[1] = MAX_MSG_SIZE;
 248         }
 249 }
 250
 251 int tipc_node_active_links(struct tipc_node *n_ptr)
 252 {
 253         return n_ptr->active_links[0] != NULL;
 254 }
 255
 256 int tipc_node_is_up(struct tipc_node *n_ptr)
 257 {
 258         return tipc_node_active_links(n_ptr);
 259 }
 260
 261 void tipc_node_attach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
 262 {
 263         n_ptr->links[l_ptr->bearer_id] = l_ptr;
 264         spin_lock_bh(&node_list_lock);
 265         tipc_num_links++;
 266         spin_unlock_bh(&node_list_lock);
 267         n_ptr->link_cnt++;
 268 }
 269
 270 void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
 271 {
 272         int i;
 273
 274         for (i = 0; i < MAX_BEARERS; i++) {
 275                 if (l_ptr != n_ptr->links[i])
 276                         continue;
 277                 n_ptr->links[i] = NULL;
 278                 spin_lock_bh(&node_list_lock);
 279                 tipc_num_links--;
 280                 spin_unlock_bh(&node_list_lock);
 281                 n_ptr->link_cnt--;
 282         }
 283 }
 284
 285 static void node_established_contact(struct tipc_node *n_ptr)
 286 {
 287         n_ptr->action_flags |= TIPC_NOTIFY_NODE_UP;
 288         n_ptr->bclink.oos_state = 0;
 289         n_ptr->bclink.acked = tipc_bclink_get_last_sent();
 290         tipc_bclink_add_node(n_ptr->addr);
 291 }
 292
 293 static void node_lost_contact(struct tipc_node *n_ptr)
 294 {
 295         char addr_string[16];
 296         u32 i;
 297
 298         pr_info("Lost contact with %s\n",
 299                 tipc_addr_string_fill(addr_string, n_ptr->addr));
 300
 301         /* Flush broadcast link info associated with lost node */
 302         if (n_ptr->bclink.recv_permitted) {
 303                 kfree_skb_list(n_ptr->bclink.deferred_head);
 304                 n_ptr->bclink.deferred_size = 0;
 305
 306                 if (n_ptr->bclink.reasm_buf) {
 307                         kfree_skb(n_ptr->bclink.reasm_buf);
 308                         n_ptr->bclink.reasm_buf = NULL;
 309                 }
 310
 311                 tipc_bclink_remove_node(n_ptr->addr);
 312                 tipc_bclink_acknowledge(n_ptr, INVALID_LINK_SEQ);
 313
 314                 n_ptr->bclink.recv_permitted = false;
 315         }
 316
 317         /* Abort link changeover */
 318         for (i = 0; i < MAX_BEARERS; i++) {
 319                 struct tipc_link *l_ptr = n_ptr->links[i];
 320                 if (!l_ptr)
 321                         continue;
 322                 l_ptr->reset_checkpoint = l_ptr->next_in_no;
 323                 l_ptr->exp_msg_count = 0;
 324                 tipc_link_reset_fragments(l_ptr);
 325         }
 326
 327         n_ptr->action_flags &= ~TIPC_WAIT_OWN_LINKS_DOWN;
 328
 329         /* Notify subscribers and prevent re-contact with node until
 330          * cleanup is done.
 331          */
 332         n_ptr->action_flags |= TIPC_WAIT_PEER_LINKS_DOWN |
 333                                TIPC_NOTIFY_NODE_DOWN;
 334 }
 335
 336 struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space)
 337 {
 338         u32 domain;
 339         struct sk_buff *buf;
 340         struct tipc_node *n_ptr;
 341         struct tipc_node_info node_info;
 342         u32 payload_size;
 343
 344         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
 345                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
 346
 347         domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
 348         if (!tipc_addr_domain_valid(domain))
 349                 return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
 350                                                    " (network address)");
 351
 352         spin_lock_bh(&node_list_lock);
 353         if (!tipc_num_nodes) {
 354                 spin_unlock_bh(&node_list_lock);
 355                 return tipc_cfg_reply_none();
 356         }
 357
 358         /* For now, get space for all other nodes */
 359         payload_size = TLV_SPACE(sizeof(node_info)) * tipc_num_nodes;
 360         if (payload_size > 32768u) {
 361                 spin_unlock_bh(&node_list_lock);
 362                 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
 363                                                    " (too many nodes)");
 364         }
 365         spin_unlock_bh(&node_list_lock);
 366
 367         buf = tipc_cfg_reply_alloc(payload_size);
 368         if (!buf)
 369                 return NULL;
 370
 371         /* Add TLVs for all nodes in scope */
 372         rcu_read_lock();
 373         list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
 374                 if (!tipc_in_scope(domain, n_ptr->addr))
 375                         continue;
 376                 node_info.addr = htonl(n_ptr->addr);
 377                 node_info.up = htonl(tipc_node_is_up(n_ptr));
 378                 tipc_cfg_append_tlv(buf, TIPC_TLV_NODE_INFO,
 379                                     &node_info, sizeof(node_info));
 380         }
 381         rcu_read_unlock();
 382         return buf;
 383 }
 384
 385 struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space)
 386 {
 387         u32 domain;
 388         struct sk_buff *buf;
 389         struct tipc_node *n_ptr;
 390         struct tipc_link_info link_info;
 391         u32 payload_size;
 392
 393         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
 394                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
 395
 396         domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
 397         if (!tipc_addr_domain_valid(domain))
 398                 return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
 399                                                    " (network address)");
 400
 401         if (!tipc_own_addr)
 402                 return tipc_cfg_reply_none();
 403
 404         spin_lock_bh(&node_list_lock);
 405         /* Get space for all unicast links + broadcast link */
 406         payload_size = TLV_SPACE((sizeof(link_info)) * (tipc_num_links + 1));
 407         if (payload_size > 32768u) {
 408                 spin_unlock_bh(&node_list_lock);
 409                 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
 410                                                    " (too many links)");
 411         }
 412         spin_unlock_bh(&node_list_lock);
 413
 414         buf = tipc_cfg_reply_alloc(payload_size);
 415         if (!buf)
 416                 return NULL;
 417
 418         /* Add TLV for broadcast link */
 419         link_info.dest = htonl(tipc_cluster_mask(tipc_own_addr));
 420         link_info.up = htonl(1);
 421         strlcpy(link_info.str, tipc_bclink_name, TIPC_MAX_LINK_NAME);
 422         tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO, &link_info, sizeof(link_info));
 423
 424         /* Add TLVs for any other links in scope */
 425         rcu_read_lock();
 426         list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
 427                 u32 i;
 428
 429                 if (!tipc_in_scope(domain, n_ptr->addr))
 430                         continue;
 431                 tipc_node_lock(n_ptr);
 432                 for (i = 0; i < MAX_BEARERS; i++) {
 433                         if (!n_ptr->links[i])
 434                                 continue;
 435                         link_info.dest = htonl(n_ptr->addr);
 436                         link_info.up = htonl(tipc_link_is_up(n_ptr->links[i]));
 437                         strcpy(link_info.str, n_ptr->links[i]->name);
 438                         tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO,
 439                                             &link_info, sizeof(link_info));
 440                 }
 441                 tipc_node_unlock(n_ptr);
 442         }
 443         rcu_read_unlock();
 444         return buf;
 445 }
 446
 447 /**
 448  * tipc_node_get_linkname - get the name of a link
 449  *
 450  * @bearer_id: id of the bearer
 451  * @node: peer node address
 452  * @linkname: link name output buffer
 453  *
 454  * Returns 0 on success
 455  */
 456 int tipc_node_get_linkname(u32 bearer_id, u32 addr, char *linkname, size_t len)
 457 {
 458         struct tipc_link *link;
 459         struct tipc_node *node = tipc_node_find(addr);
 460
 461         if ((bearer_id >= MAX_BEARERS) || !node)
 462                 return -EINVAL;
 463         tipc_node_lock(node);
 464         link = node->links[bearer_id];
 465         if (link) {
 466                 strncpy(linkname, link->name, len);
 467                 tipc_node_unlock(node);
 468                 return 0;
 469         }
 470         tipc_node_unlock(node);
 471         return -EINVAL;
 472 }
 473
 474 void tipc_node_unlock(struct tipc_node *node)
 475 {
 476         LIST_HEAD(nsub_list);
 477         u32 addr = 0;
 478
 479         if (likely(!node->action_flags)) {
 480                 spin_unlock_bh(&node->lock);
 481                 return;
 482         }
 483
 484         if (node->action_flags & TIPC_NOTIFY_NODE_DOWN) {
 485                 list_replace_init(&node->nsub, &nsub_list);
 486                 node->action_flags &= ~TIPC_NOTIFY_NODE_DOWN;
 487         }
 488         if (node->action_flags & TIPC_NOTIFY_NODE_UP) {
 489                 node->action_flags &= ~TIPC_NOTIFY_NODE_UP;
 490                 addr = node->addr;
 491         }
 492         spin_unlock_bh(&node->lock);
 493
 494         if (!list_empty(&nsub_list))
 495                 tipc_nodesub_notify(&nsub_list);
 496         if (addr)
 497                 tipc_named_node_up(addr);
 498 }