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 #include "socket.h"
  42
  43 #define NODE_HTABLE_SIZE 512
  44
  45 static void node_lost_contact(struct tipc_node *n_ptr);
  46 static void node_established_contact(struct tipc_node *n_ptr);
  47
  48 static struct hlist_head node_htable[NODE_HTABLE_SIZE];
  49 LIST_HEAD(tipc_node_list);
  50 static u32 tipc_num_nodes;
  51 static u32 tipc_num_links;
  52 static DEFINE_SPINLOCK(node_list_lock);
  53
  54 /*
  55  * A trivial power-of-two bitmask technique is used for speed, since this
  56  * operation is done for every incoming TIPC packet. The number of hash table
  57  * entries has been chosen so that no hash chain exceeds 8 nodes and will
  58  * usually be much smaller (typically only a single node).
  59  */
  60 static unsigned int tipc_hashfn(u32 addr)
  61 {
  62         return addr & (NODE_HTABLE_SIZE - 1);
  63 }
  64
  65 /*
  66  * tipc_node_find - locate specified node object, if it exists
  67  */
  68 struct tipc_node *tipc_node_find(u32 addr)
  69 {
  70         struct tipc_node *node;
  71
  72         if (unlikely(!in_own_cluster_exact(addr)))
  73                 return NULL;
  74
  75         rcu_read_lock();
  76         hlist_for_each_entry_rcu(node, &node_htable[tipc_hashfn(addr)], hash) {
  77                 if (node->addr == addr) {
  78                         rcu_read_unlock();
  79                         return node;
  80                 }
  81         }
  82         rcu_read_unlock();
  83         return NULL;
  84 }
  85
  86 struct tipc_node *tipc_node_create(u32 addr)
  87 {
  88         struct tipc_node *n_ptr, *temp_node;
  89
  90         spin_lock_bh(&node_list_lock);
  91
  92         n_ptr = kzalloc(sizeof(*n_ptr), GFP_ATOMIC);
  93         if (!n_ptr) {
  94                 spin_unlock_bh(&node_list_lock);
  95                 pr_warn("Node creation failed, no memory\n");
  96                 return NULL;
  97         }
  98
  99         n_ptr->addr = addr;
 100         spin_lock_init(&n_ptr->lock);
 101         INIT_HLIST_NODE(&n_ptr->hash);
 102         INIT_LIST_HEAD(&n_ptr->list);
 103         INIT_LIST_HEAD(&n_ptr->nsub);
 104         __skb_queue_head_init(&n_ptr->waiting_sks);
 105
 106         hlist_add_head_rcu(&n_ptr->hash, &node_htable[tipc_hashfn(addr)]);
 107
 108         list_for_each_entry_rcu(temp_node, &tipc_node_list, list) {
 109                 if (n_ptr->addr < temp_node->addr)
 110                         break;
 111         }
 112         list_add_tail_rcu(&n_ptr->list, &temp_node->list);
 113         n_ptr->action_flags = TIPC_WAIT_PEER_LINKS_DOWN;
 114         n_ptr->signature = INVALID_NODE_SIG;
 115
 116         tipc_num_nodes++;
 117
 118         spin_unlock_bh(&node_list_lock);
 119         return n_ptr;
 120 }
 121
 122 static void tipc_node_delete(struct tipc_node *n_ptr)
 123 {
 124         list_del_rcu(&n_ptr->list);
 125         hlist_del_rcu(&n_ptr->hash);
 126         kfree_rcu(n_ptr, rcu);
 127
 128         tipc_num_nodes--;
 129 }
 130
 131 void tipc_node_stop(void)
 132 {
 133         struct tipc_node *node, *t_node;
 134
 135         spin_lock_bh(&node_list_lock);
 136         list_for_each_entry_safe(node, t_node, &tipc_node_list, list)
 137                 tipc_node_delete(node);
 138         spin_unlock_bh(&node_list_lock);
 139 }
 140
 141 /**
 142  * tipc_node_link_up - handle addition of link
 143  *
 144  * Link becomes active (alone or shared) or standby, depending on its priority.
 145  */
 146 void tipc_node_link_up(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
 147 {
 148         struct tipc_link **active = &n_ptr->active_links[0];
 149         u32 addr = n_ptr->addr;
 150
 151         n_ptr->working_links++;
 152         tipc_nametbl_publish(TIPC_LINK_STATE, addr, addr, TIPC_NODE_SCOPE,
 153                              l_ptr->bearer_id, addr);
 154         pr_info("Established link <%s> on network plane %c\n",
 155                 l_ptr->name, l_ptr->net_plane);
 156
 157         if (!active[0]) {
 158                 active[0] = active[1] = l_ptr;
 159                 node_established_contact(n_ptr);
 160                 goto exit;
 161         }
 162         if (l_ptr->priority < active[0]->priority) {
 163                 pr_info("New link <%s> becomes standby\n", l_ptr->name);
 164                 goto exit;
 165         }
 166         tipc_link_dup_queue_xmit(active[0], l_ptr);
 167         if (l_ptr->priority == active[0]->priority) {
 168                 active[0] = l_ptr;
 169                 goto exit;
 170         }
 171         pr_info("Old link <%s> becomes standby\n", active[0]->name);
 172         if (active[1] != active[0])
 173                 pr_info("Old link <%s> becomes standby\n", active[1]->name);
 174         active[0] = active[1] = l_ptr;
 175 exit:
 176         /* Leave room for changeover header when returning 'mtu' to users: */
 177         n_ptr->act_mtus[0] = active[0]->max_pkt - INT_H_SIZE;
 178         n_ptr->act_mtus[1] = active[1]->max_pkt - INT_H_SIZE;
 179 }
 180
 181 /**
 182  * node_select_active_links - select active link
 183  */
 184 static void node_select_active_links(struct tipc_node *n_ptr)
 185 {
 186         struct tipc_link **active = &n_ptr->active_links[0];
 187         u32 i;
 188         u32 highest_prio = 0;
 189
 190         active[0] = active[1] = NULL;
 191
 192         for (i = 0; i < MAX_BEARERS; i++) {
 193                 struct tipc_link *l_ptr = n_ptr->links[i];
 194
 195                 if (!l_ptr || !tipc_link_is_up(l_ptr) ||
 196                     (l_ptr->priority < highest_prio))
 197                         continue;
 198
 199                 if (l_ptr->priority > highest_prio) {
 200                         highest_prio = l_ptr->priority;
 201                         active[0] = active[1] = l_ptr;
 202                 } else {
 203                         active[1] = l_ptr;
 204                 }
 205         }
 206 }
 207
 208 /**
 209  * tipc_node_link_down - handle loss of link
 210  */
 211 void tipc_node_link_down(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
 212 {
 213         struct tipc_link **active;
 214         u32 addr = n_ptr->addr;
 215
 216         n_ptr->working_links--;
 217         tipc_nametbl_withdraw(TIPC_LINK_STATE, addr, l_ptr->bearer_id, addr);
 218
 219         if (!tipc_link_is_active(l_ptr)) {
 220                 pr_info("Lost standby link <%s> on network plane %c\n",
 221                         l_ptr->name, l_ptr->net_plane);
 222                 return;
 223         }
 224         pr_info("Lost link <%s> on network plane %c\n",
 225                 l_ptr->name, l_ptr->net_plane);
 226
 227         active = &n_ptr->active_links[0];
 228         if (active[0] == l_ptr)
 229                 active[0] = active[1];
 230         if (active[1] == l_ptr)
 231                 active[1] = active[0];
 232         if (active[0] == l_ptr)
 233                 node_select_active_links(n_ptr);
 234         if (tipc_node_is_up(n_ptr))
 235                 tipc_link_failover_send_queue(l_ptr);
 236         else
 237                 node_lost_contact(n_ptr);
 238
 239         /* Leave room for changeover header when returning 'mtu' to users: */
 240         if (active[0]) {
 241                 n_ptr->act_mtus[0] = active[0]->max_pkt - INT_H_SIZE;
 242                 n_ptr->act_mtus[1] = active[1]->max_pkt - INT_H_SIZE;
 243                 return;
 244         }
 245
 246         /* Loopback link went down? No fragmentation needed from now on. */
 247         if (n_ptr->addr == tipc_own_addr) {
 248                 n_ptr->act_mtus[0] = MAX_MSG_SIZE;
 249                 n_ptr->act_mtus[1] = MAX_MSG_SIZE;
 250         }
 251 }
 252
 253 int tipc_node_active_links(struct tipc_node *n_ptr)
 254 {
 255         return n_ptr->active_links[0] != NULL;
 256 }
 257
 258 int tipc_node_is_up(struct tipc_node *n_ptr)
 259 {
 260         return tipc_node_active_links(n_ptr);
 261 }
 262
 263 void tipc_node_attach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
 264 {
 265         n_ptr->links[l_ptr->bearer_id] = l_ptr;
 266         spin_lock_bh(&node_list_lock);
 267         tipc_num_links++;
 268         spin_unlock_bh(&node_list_lock);
 269         n_ptr->link_cnt++;
 270 }
 271
 272 void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
 273 {
 274         int i;
 275
 276         for (i = 0; i < MAX_BEARERS; i++) {
 277                 if (l_ptr != n_ptr->links[i])
 278                         continue;
 279                 n_ptr->links[i] = NULL;
 280                 spin_lock_bh(&node_list_lock);
 281                 tipc_num_links--;
 282                 spin_unlock_bh(&node_list_lock);
 283                 n_ptr->link_cnt--;
 284         }
 285 }
 286
 287 static void node_established_contact(struct tipc_node *n_ptr)
 288 {
 289         n_ptr->action_flags |= TIPC_NOTIFY_NODE_UP;
 290         n_ptr->bclink.oos_state = 0;
 291         n_ptr->bclink.acked = tipc_bclink_get_last_sent();
 292         tipc_bclink_add_node(n_ptr->addr);
 293 }
 294
 295 static void node_lost_contact(struct tipc_node *n_ptr)
 296 {
 297         char addr_string[16];
 298         u32 i;
 299
 300         pr_info("Lost contact with %s\n",
 301                 tipc_addr_string_fill(addr_string, n_ptr->addr));
 302
 303         /* Flush broadcast link info associated with lost node */
 304         if (n_ptr->bclink.recv_permitted) {
 305                 kfree_skb_list(n_ptr->bclink.deferred_head);
 306                 n_ptr->bclink.deferred_size = 0;
 307
 308                 if (n_ptr->bclink.reasm_buf) {
 309                         kfree_skb(n_ptr->bclink.reasm_buf);
 310                         n_ptr->bclink.reasm_buf = NULL;
 311                 }
 312
 313                 tipc_bclink_remove_node(n_ptr->addr);
 314                 tipc_bclink_acknowledge(n_ptr, INVALID_LINK_SEQ);
 315
 316                 n_ptr->bclink.recv_permitted = false;
 317         }
 318
 319         /* Abort link changeover */
 320         for (i = 0; i < MAX_BEARERS; i++) {
 321                 struct tipc_link *l_ptr = n_ptr->links[i];
 322                 if (!l_ptr)
 323                         continue;
 324                 l_ptr->reset_checkpoint = l_ptr->next_in_no;
 325                 l_ptr->exp_msg_count = 0;
 326                 tipc_link_reset_fragments(l_ptr);
 327         }
 328
 329         n_ptr->action_flags &= ~TIPC_WAIT_OWN_LINKS_DOWN;
 330
 331         /* Notify subscribers and prevent re-contact with node until
 332          * cleanup is done.
 333          */
 334         n_ptr->action_flags |= TIPC_WAIT_PEER_LINKS_DOWN |
 335                                TIPC_NOTIFY_NODE_DOWN;
 336 }
 337
 338 struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space)
 339 {
 340         u32 domain;
 341         struct sk_buff *buf;
 342         struct tipc_node *n_ptr;
 343         struct tipc_node_info node_info;
 344         u32 payload_size;
 345
 346         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
 347                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
 348
 349         domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
 350         if (!tipc_addr_domain_valid(domain))
 351                 return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
 352                                                    " (network address)");
 353
 354         spin_lock_bh(&node_list_lock);
 355         if (!tipc_num_nodes) {
 356                 spin_unlock_bh(&node_list_lock);
 357                 return tipc_cfg_reply_none();
 358         }
 359
 360         /* For now, get space for all other nodes */
 361         payload_size = TLV_SPACE(sizeof(node_info)) * tipc_num_nodes;
 362         if (payload_size > 32768u) {
 363                 spin_unlock_bh(&node_list_lock);
 364                 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
 365                                                    " (too many nodes)");
 366         }
 367         spin_unlock_bh(&node_list_lock);
 368
 369         buf = tipc_cfg_reply_alloc(payload_size);
 370         if (!buf)
 371                 return NULL;
 372
 373         /* Add TLVs for all nodes in scope */
 374         rcu_read_lock();
 375         list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
 376                 if (!tipc_in_scope(domain, n_ptr->addr))
 377                         continue;
 378                 node_info.addr = htonl(n_ptr->addr);
 379                 node_info.up = htonl(tipc_node_is_up(n_ptr));
 380                 tipc_cfg_append_tlv(buf, TIPC_TLV_NODE_INFO,
 381                                     &node_info, sizeof(node_info));
 382         }
 383         rcu_read_unlock();
 384         return buf;
 385 }
 386
 387 struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space)
 388 {
 389         u32 domain;
 390         struct sk_buff *buf;
 391         struct tipc_node *n_ptr;
 392         struct tipc_link_info link_info;
 393         u32 payload_size;
 394
 395         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
 396                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
 397
 398         domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
 399         if (!tipc_addr_domain_valid(domain))
 400                 return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
 401                                                    " (network address)");
 402
 403         if (!tipc_own_addr)
 404                 return tipc_cfg_reply_none();
 405
 406         spin_lock_bh(&node_list_lock);
 407         /* Get space for all unicast links + broadcast link */
 408         payload_size = TLV_SPACE((sizeof(link_info)) * (tipc_num_links + 1));
 409         if (payload_size > 32768u) {
 410                 spin_unlock_bh(&node_list_lock);
 411                 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
 412                                                    " (too many links)");
 413         }
 414         spin_unlock_bh(&node_list_lock);
 415
 416         buf = tipc_cfg_reply_alloc(payload_size);
 417         if (!buf)
 418                 return NULL;
 419
 420         /* Add TLV for broadcast link */
 421         link_info.dest = htonl(tipc_cluster_mask(tipc_own_addr));
 422         link_info.up = htonl(1);
 423         strlcpy(link_info.str, tipc_bclink_name, TIPC_MAX_LINK_NAME);
 424         tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO, &link_info, sizeof(link_info));
 425
 426         /* Add TLVs for any other links in scope */
 427         rcu_read_lock();
 428         list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
 429                 u32 i;
 430
 431                 if (!tipc_in_scope(domain, n_ptr->addr))
 432                         continue;
 433                 tipc_node_lock(n_ptr);
 434                 for (i = 0; i < MAX_BEARERS; i++) {
 435                         if (!n_ptr->links[i])
 436                                 continue;
 437                         link_info.dest = htonl(n_ptr->addr);
 438                         link_info.up = htonl(tipc_link_is_up(n_ptr->links[i]));
 439                         strcpy(link_info.str, n_ptr->links[i]->name);
 440                         tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO,
 441                                             &link_info, sizeof(link_info));
 442                 }
 443                 tipc_node_unlock(n_ptr);
 444         }
 445         rcu_read_unlock();
 446         return buf;
 447 }
 448
 449 /**
 450  * tipc_node_get_linkname - get the name of a link
 451  *
 452  * @bearer_id: id of the bearer
 453  * @node: peer node address
 454  * @linkname: link name output buffer
 455  *
 456  * Returns 0 on success
 457  */
 458 int tipc_node_get_linkname(u32 bearer_id, u32 addr, char *linkname, size_t len)
 459 {
 460         struct tipc_link *link;
 461         struct tipc_node *node = tipc_node_find(addr);
 462
 463         if ((bearer_id >= MAX_BEARERS) || !node)
 464                 return -EINVAL;
 465         tipc_node_lock(node);
 466         link = node->links[bearer_id];
 467         if (link) {
 468                 strncpy(linkname, link->name, len);
 469                 tipc_node_unlock(node);
 470                 return 0;
 471         }
 472         tipc_node_unlock(node);
 473         return -EINVAL;
 474 }
 475
 476 void tipc_node_unlock(struct tipc_node *node)
 477 {
 478         LIST_HEAD(nsub_list);
 479         struct sk_buff_head waiting_sks;
 480         u32 addr = 0;
 481
 482         if (likely(!node->action_flags)) {
 483                 spin_unlock_bh(&node->lock);
 484                 return;
 485         }
 486
 487         __skb_queue_head_init(&waiting_sks);
 488         if (node->action_flags & TIPC_WAKEUP_USERS) {
 489                 skb_queue_splice_init(&node->waiting_sks, &waiting_sks);
 490                 node->action_flags &= ~TIPC_WAKEUP_USERS;
 491         }
 492         if (node->action_flags & TIPC_NOTIFY_NODE_DOWN) {
 493                 list_replace_init(&node->nsub, &nsub_list);
 494                 node->action_flags &= ~TIPC_NOTIFY_NODE_DOWN;
 495         }
 496         if (node->action_flags & TIPC_NOTIFY_NODE_UP) {
 497                 node->action_flags &= ~TIPC_NOTIFY_NODE_UP;
 498                 addr = node->addr;
 499         }
 500         spin_unlock_bh(&node->lock);
 501
 502         while (!skb_queue_empty(&waiting_sks))
 503                 tipc_sk_rcv(__skb_dequeue(&waiting_sks));
 504
 505         if (!list_empty(&nsub_list))
 506                 tipc_nodesub_notify(&nsub_list);
 507
 508         if (addr)
 509                 tipc_named_node_up(addr);
 510 }