net/tipc/node.c

   1 /*
   2  * net/tipc/node.c: TIPC node management routines
   3  *
   4  * Copyright (c) 2000-2006, 2012 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                 return;
 159         }
 160         if (l_ptr->priority < active[0]->priority) {
 161                 pr_info("New link <%s> becomes standby\n", l_ptr->name);
 162                 return;
 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                 return;
 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 }
 174
 175 /**
 176  * node_select_active_links - select active link
 177  */
 178 static void node_select_active_links(struct tipc_node *n_ptr)
 179 {
 180         struct tipc_link **active = &n_ptr->active_links[0];
 181         u32 i;
 182         u32 highest_prio = 0;
 183
 184         active[0] = active[1] = NULL;
 185
 186         for (i = 0; i < MAX_BEARERS; i++) {
 187                 struct tipc_link *l_ptr = n_ptr->links[i];
 188
 189                 if (!l_ptr || !tipc_link_is_up(l_ptr) ||
 190                     (l_ptr->priority < highest_prio))
 191                         continue;
 192
 193                 if (l_ptr->priority > highest_prio) {
 194                         highest_prio = l_ptr->priority;
 195                         active[0] = active[1] = l_ptr;
 196                 } else {
 197                         active[1] = l_ptr;
 198                 }
 199         }
 200 }
 201
 202 /**
 203  * tipc_node_link_down - handle loss of link
 204  */
 205 void tipc_node_link_down(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
 206 {
 207         struct tipc_link **active;
 208         u32 addr = n_ptr->addr;
 209
 210         n_ptr->working_links--;
 211         tipc_nametbl_withdraw(TIPC_LINK_STATE, addr, l_ptr->bearer_id, addr);
 212
 213         if (!tipc_link_is_active(l_ptr)) {
 214                 pr_info("Lost standby link <%s> on network plane %c\n",
 215                         l_ptr->name, l_ptr->net_plane);
 216                 return;
 217         }
 218         pr_info("Lost link <%s> on network plane %c\n",
 219                 l_ptr->name, l_ptr->net_plane);
 220
 221         active = &n_ptr->active_links[0];
 222         if (active[0] == l_ptr)
 223                 active[0] = active[1];
 224         if (active[1] == l_ptr)
 225                 active[1] = active[0];
 226         if (active[0] == l_ptr)
 227                 node_select_active_links(n_ptr);
 228         if (tipc_node_is_up(n_ptr))
 229                 tipc_link_failover_send_queue(l_ptr);
 230         else
 231                 node_lost_contact(n_ptr);
 232 }
 233
 234 int tipc_node_active_links(struct tipc_node *n_ptr)
 235 {
 236         return n_ptr->active_links[0] != NULL;
 237 }
 238
 239 int tipc_node_is_up(struct tipc_node *n_ptr)
 240 {
 241         return tipc_node_active_links(n_ptr);
 242 }
 243
 244 void tipc_node_attach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
 245 {
 246         n_ptr->links[l_ptr->bearer_id] = l_ptr;
 247         spin_lock_bh(&node_list_lock);
 248         tipc_num_links++;
 249         spin_unlock_bh(&node_list_lock);
 250         n_ptr->link_cnt++;
 251 }
 252
 253 void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
 254 {
 255         int i;
 256
 257         for (i = 0; i < MAX_BEARERS; i++) {
 258                 if (l_ptr != n_ptr->links[i])
 259                         continue;
 260                 n_ptr->links[i] = NULL;
 261                 spin_lock_bh(&node_list_lock);
 262                 tipc_num_links--;
 263                 spin_unlock_bh(&node_list_lock);
 264                 n_ptr->link_cnt--;
 265         }
 266 }
 267
 268 static void node_established_contact(struct tipc_node *n_ptr)
 269 {
 270         n_ptr->action_flags |= TIPC_NOTIFY_NODE_UP;
 271         n_ptr->bclink.oos_state = 0;
 272         n_ptr->bclink.acked = tipc_bclink_get_last_sent();
 273         tipc_bclink_add_node(n_ptr->addr);
 274 }
 275
 276 static void node_lost_contact(struct tipc_node *n_ptr)
 277 {
 278         char addr_string[16];
 279         u32 i;
 280
 281         pr_info("Lost contact with %s\n",
 282                 tipc_addr_string_fill(addr_string, n_ptr->addr));
 283
 284         /* Flush broadcast link info associated with lost node */
 285         if (n_ptr->bclink.recv_permitted) {
 286                 kfree_skb_list(n_ptr->bclink.deferred_head);
 287                 n_ptr->bclink.deferred_size = 0;
 288
 289                 if (n_ptr->bclink.reasm_buf) {
 290                         kfree_skb(n_ptr->bclink.reasm_buf);
 291                         n_ptr->bclink.reasm_buf = NULL;
 292                 }
 293
 294                 tipc_bclink_remove_node(n_ptr->addr);
 295                 tipc_bclink_acknowledge(n_ptr, INVALID_LINK_SEQ);
 296
 297                 n_ptr->bclink.recv_permitted = false;
 298         }
 299
 300         /* Abort link changeover */
 301         for (i = 0; i < MAX_BEARERS; i++) {
 302                 struct tipc_link *l_ptr = n_ptr->links[i];
 303                 if (!l_ptr)
 304                         continue;
 305                 l_ptr->reset_checkpoint = l_ptr->next_in_no;
 306                 l_ptr->exp_msg_count = 0;
 307                 tipc_link_reset_fragments(l_ptr);
 308         }
 309
 310         n_ptr->action_flags &= ~TIPC_WAIT_OWN_LINKS_DOWN;
 311
 312         /* Notify subscribers and prevent re-contact with node until
 313          * cleanup is done.
 314          */
 315         n_ptr->action_flags |= TIPC_WAIT_PEER_LINKS_DOWN |
 316                                TIPC_NOTIFY_NODE_DOWN;
 317 }
 318
 319 struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space)
 320 {
 321         u32 domain;
 322         struct sk_buff *buf;
 323         struct tipc_node *n_ptr;
 324         struct tipc_node_info node_info;
 325         u32 payload_size;
 326
 327         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
 328                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
 329
 330         domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
 331         if (!tipc_addr_domain_valid(domain))
 332                 return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
 333                                                    " (network address)");
 334
 335         spin_lock_bh(&node_list_lock);
 336         if (!tipc_num_nodes) {
 337                 spin_unlock_bh(&node_list_lock);
 338                 return tipc_cfg_reply_none();
 339         }
 340
 341         /* For now, get space for all other nodes */
 342         payload_size = TLV_SPACE(sizeof(node_info)) * tipc_num_nodes;
 343         if (payload_size > 32768u) {
 344                 spin_unlock_bh(&node_list_lock);
 345                 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
 346                                                    " (too many nodes)");
 347         }
 348         spin_unlock_bh(&node_list_lock);
 349
 350         buf = tipc_cfg_reply_alloc(payload_size);
 351         if (!buf)
 352                 return NULL;
 353
 354         /* Add TLVs for all nodes in scope */
 355         rcu_read_lock();
 356         list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
 357                 if (!tipc_in_scope(domain, n_ptr->addr))
 358                         continue;
 359                 node_info.addr = htonl(n_ptr->addr);
 360                 node_info.up = htonl(tipc_node_is_up(n_ptr));
 361                 tipc_cfg_append_tlv(buf, TIPC_TLV_NODE_INFO,
 362                                     &node_info, sizeof(node_info));
 363         }
 364         rcu_read_unlock();
 365         return buf;
 366 }
 367
 368 struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space)
 369 {
 370         u32 domain;
 371         struct sk_buff *buf;
 372         struct tipc_node *n_ptr;
 373         struct tipc_link_info link_info;
 374         u32 payload_size;
 375
 376         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
 377                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
 378
 379         domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
 380         if (!tipc_addr_domain_valid(domain))
 381                 return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
 382                                                    " (network address)");
 383
 384         if (!tipc_own_addr)
 385                 return tipc_cfg_reply_none();
 386
 387         spin_lock_bh(&node_list_lock);
 388         /* Get space for all unicast links + broadcast link */
 389         payload_size = TLV_SPACE((sizeof(link_info)) * (tipc_num_links + 1));
 390         if (payload_size > 32768u) {
 391                 spin_unlock_bh(&node_list_lock);
 392                 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
 393                                                    " (too many links)");
 394         }
 395         spin_unlock_bh(&node_list_lock);
 396
 397         buf = tipc_cfg_reply_alloc(payload_size);
 398         if (!buf)
 399                 return NULL;
 400
 401         /* Add TLV for broadcast link */
 402         link_info.dest = htonl(tipc_cluster_mask(tipc_own_addr));
 403         link_info.up = htonl(1);
 404         strlcpy(link_info.str, tipc_bclink_name, TIPC_MAX_LINK_NAME);
 405         tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO, &link_info, sizeof(link_info));
 406
 407         /* Add TLVs for any other links in scope */
 408         rcu_read_lock();
 409         list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
 410                 u32 i;
 411
 412                 if (!tipc_in_scope(domain, n_ptr->addr))
 413                         continue;
 414                 tipc_node_lock(n_ptr);
 415                 for (i = 0; i < MAX_BEARERS; i++) {
 416                         if (!n_ptr->links[i])
 417                                 continue;
 418                         link_info.dest = htonl(n_ptr->addr);
 419                         link_info.up = htonl(tipc_link_is_up(n_ptr->links[i]));
 420                         strcpy(link_info.str, n_ptr->links[i]->name);
 421                         tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO,
 422                                             &link_info, sizeof(link_info));
 423                 }
 424                 tipc_node_unlock(n_ptr);
 425         }
 426         rcu_read_unlock();
 427         return buf;
 428 }
 429
 430 /**
 431  * tipc_node_get_linkname - get the name of a link
 432  *
 433  * @bearer_id: id of the bearer
 434  * @node: peer node address
 435  * @linkname: link name output buffer
 436  *
 437  * Returns 0 on success
 438  */
 439 int tipc_node_get_linkname(u32 bearer_id, u32 addr, char *linkname, size_t len)
 440 {
 441         struct tipc_link *link;
 442         struct tipc_node *node = tipc_node_find(addr);
 443
 444         if ((bearer_id >= MAX_BEARERS) || !node)
 445                 return -EINVAL;
 446         tipc_node_lock(node);
 447         link = node->links[bearer_id];
 448         if (link) {
 449                 strncpy(linkname, link->name, len);
 450                 tipc_node_unlock(node);
 451                 return 0;
 452         }
 453         tipc_node_unlock(node);
 454         return -EINVAL;
 455 }
 456
 457 void tipc_node_unlock(struct tipc_node *node)
 458 {
 459         LIST_HEAD(nsub_list);
 460         struct tipc_link *link;
 461         int pkt_sz = 0;
 462         u32 addr = 0;
 463
 464         if (likely(!node->action_flags)) {
 465                 spin_unlock_bh(&node->lock);
 466                 return;
 467         }
 468
 469         if (node->action_flags & TIPC_NOTIFY_NODE_DOWN) {
 470                 list_replace_init(&node->nsub, &nsub_list);
 471                 node->action_flags &= ~TIPC_NOTIFY_NODE_DOWN;
 472         }
 473         if (node->action_flags & TIPC_NOTIFY_NODE_UP) {
 474                 link = node->active_links[0];
 475                 node->action_flags &= ~TIPC_NOTIFY_NODE_UP;
 476                 if (link) {
 477                         pkt_sz = ((link->max_pkt - INT_H_SIZE) / ITEM_SIZE) *
 478                                   ITEM_SIZE;
 479                         addr = node->addr;
 480                 }
 481         }
 482         spin_unlock_bh(&node->lock);
 483
 484         if (!list_empty(&nsub_list))
 485                 tipc_nodesub_notify(&nsub_list);
 486         if (pkt_sz)
 487                 tipc_named_node_up(pkt_sz, addr);
 488 }