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->block_setup = WAIT_PEER_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
 148         n_ptr->working_links++;
 149
 150         pr_info("Established link <%s> on network plane %c\n",
 151                 l_ptr->name, l_ptr->b_ptr->net_plane);
 152
 153         if (!active[0]) {
 154                 active[0] = active[1] = l_ptr;
 155                 node_established_contact(n_ptr);
 156                 return;
 157         }
 158         if (l_ptr->priority < active[0]->priority) {
 159                 pr_info("New link <%s> becomes standby\n", l_ptr->name);
 160                 return;
 161         }
 162         tipc_link_dup_queue_xmit(active[0], l_ptr);
 163         if (l_ptr->priority == active[0]->priority) {
 164                 active[0] = l_ptr;
 165                 return;
 166         }
 167         pr_info("Old link <%s> becomes standby\n", active[0]->name);
 168         if (active[1] != active[0])
 169                 pr_info("Old link <%s> becomes standby\n", active[1]->name);
 170         active[0] = active[1] = l_ptr;
 171 }
 172
 173 /**
 174  * node_select_active_links - select active link
 175  */
 176 static void node_select_active_links(struct tipc_node *n_ptr)
 177 {
 178         struct tipc_link **active = &n_ptr->active_links[0];
 179         u32 i;
 180         u32 highest_prio = 0;
 181
 182         active[0] = active[1] = NULL;
 183
 184         for (i = 0; i < MAX_BEARERS; i++) {
 185                 struct tipc_link *l_ptr = n_ptr->links[i];
 186
 187                 if (!l_ptr || !tipc_link_is_up(l_ptr) ||
 188                     (l_ptr->priority < highest_prio))
 189                         continue;
 190
 191                 if (l_ptr->priority > highest_prio) {
 192                         highest_prio = l_ptr->priority;
 193                         active[0] = active[1] = l_ptr;
 194                 } else {
 195                         active[1] = l_ptr;
 196                 }
 197         }
 198 }
 199
 200 /**
 201  * tipc_node_link_down - handle loss of link
 202  */
 203 void tipc_node_link_down(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
 204 {
 205         struct tipc_link **active;
 206
 207         n_ptr->working_links--;
 208
 209         if (!tipc_link_is_active(l_ptr)) {
 210                 pr_info("Lost standby link <%s> on network plane %c\n",
 211                         l_ptr->name, l_ptr->b_ptr->net_plane);
 212                 return;
 213         }
 214         pr_info("Lost link <%s> on network plane %c\n",
 215                 l_ptr->name, l_ptr->b_ptr->net_plane);
 216
 217         active = &n_ptr->active_links[0];
 218         if (active[0] == l_ptr)
 219                 active[0] = active[1];
 220         if (active[1] == l_ptr)
 221                 active[1] = active[0];
 222         if (active[0] == l_ptr)
 223                 node_select_active_links(n_ptr);
 224         if (tipc_node_is_up(n_ptr))
 225                 tipc_link_failover_send_queue(l_ptr);
 226         else
 227                 node_lost_contact(n_ptr);
 228 }
 229
 230 int tipc_node_active_links(struct tipc_node *n_ptr)
 231 {
 232         return n_ptr->active_links[0] != NULL;
 233 }
 234
 235 int tipc_node_is_up(struct tipc_node *n_ptr)
 236 {
 237         return tipc_node_active_links(n_ptr);
 238 }
 239
 240 void tipc_node_attach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
 241 {
 242         n_ptr->links[l_ptr->b_ptr->identity] = l_ptr;
 243         spin_lock_bh(&node_list_lock);
 244         tipc_num_links++;
 245         spin_unlock_bh(&node_list_lock);
 246         n_ptr->link_cnt++;
 247 }
 248
 249 void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
 250 {
 251         int i;
 252
 253         for (i = 0; i < MAX_BEARERS; i++) {
 254                 if (l_ptr != n_ptr->links[i])
 255                         continue;
 256                 n_ptr->links[i] = NULL;
 257                 spin_lock_bh(&node_list_lock);
 258                 tipc_num_links--;
 259                 spin_unlock_bh(&node_list_lock);
 260                 n_ptr->link_cnt--;
 261         }
 262 }
 263
 264 static void node_established_contact(struct tipc_node *n_ptr)
 265 {
 266         tipc_k_signal((Handler)tipc_named_node_up, n_ptr->addr);
 267         n_ptr->bclink.oos_state = 0;
 268         n_ptr->bclink.acked = tipc_bclink_get_last_sent();
 269         tipc_bclink_add_node(n_ptr->addr);
 270 }
 271
 272 static void node_name_purge_complete(unsigned long node_addr)
 273 {
 274         struct tipc_node *n_ptr;
 275
 276         read_lock_bh(&tipc_net_lock);
 277         n_ptr = tipc_node_find(node_addr);
 278         if (n_ptr) {
 279                 tipc_node_lock(n_ptr);
 280                 n_ptr->block_setup &= ~WAIT_NAMES_GONE;
 281                 tipc_node_unlock(n_ptr);
 282         }
 283         read_unlock_bh(&tipc_net_lock);
 284 }
 285
 286 static void node_lost_contact(struct tipc_node *n_ptr)
 287 {
 288         char addr_string[16];
 289         u32 i;
 290
 291         pr_info("Lost contact with %s\n",
 292                 tipc_addr_string_fill(addr_string, n_ptr->addr));
 293
 294         /* Flush broadcast link info associated with lost node */
 295         if (n_ptr->bclink.recv_permitted) {
 296                 kfree_skb_list(n_ptr->bclink.deferred_head);
 297                 n_ptr->bclink.deferred_size = 0;
 298
 299                 if (n_ptr->bclink.reasm_head) {
 300                         kfree_skb(n_ptr->bclink.reasm_head);
 301                         n_ptr->bclink.reasm_head = NULL;
 302                         n_ptr->bclink.reasm_tail = NULL;
 303                 }
 304
 305                 tipc_bclink_remove_node(n_ptr->addr);
 306                 tipc_bclink_acknowledge(n_ptr, INVALID_LINK_SEQ);
 307
 308                 n_ptr->bclink.recv_permitted = false;
 309         }
 310
 311         /* Abort link changeover */
 312         for (i = 0; i < MAX_BEARERS; i++) {
 313                 struct tipc_link *l_ptr = n_ptr->links[i];
 314                 if (!l_ptr)
 315                         continue;
 316                 l_ptr->reset_checkpoint = l_ptr->next_in_no;
 317                 l_ptr->exp_msg_count = 0;
 318                 tipc_link_reset_fragments(l_ptr);
 319         }
 320
 321         /* Notify subscribers */
 322         tipc_nodesub_notify(n_ptr);
 323
 324         /* Prevent re-contact with node until cleanup is done */
 325         n_ptr->block_setup = WAIT_PEER_DOWN | WAIT_NAMES_GONE;
 326         tipc_k_signal((Handler)node_name_purge_complete, n_ptr->addr);
 327 }
 328
 329 struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space)
 330 {
 331         u32 domain;
 332         struct sk_buff *buf;
 333         struct tipc_node *n_ptr;
 334         struct tipc_node_info node_info;
 335         u32 payload_size;
 336
 337         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
 338                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
 339
 340         domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
 341         if (!tipc_addr_domain_valid(domain))
 342                 return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
 343                                                    " (network address)");
 344
 345         spin_lock_bh(&node_list_lock);
 346         if (!tipc_num_nodes) {
 347                 spin_unlock_bh(&node_list_lock);
 348                 return tipc_cfg_reply_none();
 349         }
 350
 351         /* For now, get space for all other nodes */
 352         payload_size = TLV_SPACE(sizeof(node_info)) * tipc_num_nodes;
 353         if (payload_size > 32768u) {
 354                 spin_unlock_bh(&node_list_lock);
 355                 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
 356                                                    " (too many nodes)");
 357         }
 358         spin_unlock_bh(&node_list_lock);
 359
 360         buf = tipc_cfg_reply_alloc(payload_size);
 361         if (!buf)
 362                 return NULL;
 363
 364         /* Add TLVs for all nodes in scope */
 365         rcu_read_lock();
 366         list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
 367                 if (!tipc_in_scope(domain, n_ptr->addr))
 368                         continue;
 369                 node_info.addr = htonl(n_ptr->addr);
 370                 node_info.up = htonl(tipc_node_is_up(n_ptr));
 371                 tipc_cfg_append_tlv(buf, TIPC_TLV_NODE_INFO,
 372                                     &node_info, sizeof(node_info));
 373         }
 374         rcu_read_unlock();
 375         return buf;
 376 }
 377
 378 struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space)
 379 {
 380         u32 domain;
 381         struct sk_buff *buf;
 382         struct tipc_node *n_ptr;
 383         struct tipc_link_info link_info;
 384         u32 payload_size;
 385
 386         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
 387                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
 388
 389         domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
 390         if (!tipc_addr_domain_valid(domain))
 391                 return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
 392                                                    " (network address)");
 393
 394         if (!tipc_own_addr)
 395                 return tipc_cfg_reply_none();
 396
 397         spin_lock_bh(&node_list_lock);
 398         /* Get space for all unicast links + broadcast link */
 399         payload_size = TLV_SPACE((sizeof(link_info)) * (tipc_num_links + 1));
 400         if (payload_size > 32768u) {
 401                 spin_unlock_bh(&node_list_lock);
 402                 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
 403                                                    " (too many links)");
 404         }
 405         spin_unlock_bh(&node_list_lock);
 406
 407         buf = tipc_cfg_reply_alloc(payload_size);
 408         if (!buf)
 409                 return NULL;
 410
 411         /* Add TLV for broadcast link */
 412         link_info.dest = htonl(tipc_cluster_mask(tipc_own_addr));
 413         link_info.up = htonl(1);
 414         strlcpy(link_info.str, tipc_bclink_name, TIPC_MAX_LINK_NAME);
 415         tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO, &link_info, sizeof(link_info));
 416
 417         /* Add TLVs for any other links in scope */
 418         rcu_read_lock();
 419         list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
 420                 u32 i;
 421
 422                 if (!tipc_in_scope(domain, n_ptr->addr))
 423                         continue;
 424                 tipc_node_lock(n_ptr);
 425                 for (i = 0; i < MAX_BEARERS; i++) {
 426                         if (!n_ptr->links[i])
 427                                 continue;
 428                         link_info.dest = htonl(n_ptr->addr);
 429                         link_info.up = htonl(tipc_link_is_up(n_ptr->links[i]));
 430                         strcpy(link_info.str, n_ptr->links[i]->name);
 431                         tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO,
 432                                             &link_info, sizeof(link_info));
 433                 }
 434                 tipc_node_unlock(n_ptr);
 435         }
 436         rcu_read_unlock();
 437         return buf;
 438 }