| 1 | /* |
| 2 | * net/tipc/node.c: TIPC node management routines |
| 3 | * |
| 4 | * Copyright (c) 2000-2006, 2012 Ericsson AB |
| 5 | * Copyright (c) 2005-2006, 2010-2011, 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 "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 DEFINE_SPINLOCK(node_create_lock); |
| 48 | |
| 49 | static struct hlist_head node_htable[NODE_HTABLE_SIZE]; |
| 50 | LIST_HEAD(tipc_node_list); |
| 51 | static u32 tipc_num_nodes; |
| 52 | |
| 53 | static atomic_t tipc_num_links = ATOMIC_INIT(0); |
| 54 | |
| 55 | /* |
| 56 | * A trivial power-of-two bitmask technique is used for speed, since this |
| 57 | * operation is done for every incoming TIPC packet. The number of hash table |
| 58 | * entries has been chosen so that no hash chain exceeds 8 nodes and will |
| 59 | * usually be much smaller (typically only a single node). |
| 60 | */ |
| 61 | static unsigned int tipc_hashfn(u32 addr) |
| 62 | { |
| 63 | return addr & (NODE_HTABLE_SIZE - 1); |
| 64 | } |
| 65 | |
| 66 | /* |
| 67 | * tipc_node_find - locate specified node object, if it exists |
| 68 | */ |
| 69 | struct tipc_node *tipc_node_find(u32 addr) |
| 70 | { |
| 71 | struct tipc_node *node; |
| 72 | |
| 73 | if (unlikely(!in_own_cluster_exact(addr))) |
| 74 | return NULL; |
| 75 | |
| 76 | hlist_for_each_entry(node, &node_htable[tipc_hashfn(addr)], hash) { |
| 77 | if (node->addr == addr) |
| 78 | return node; |
| 79 | } |
| 80 | return NULL; |
| 81 | } |
| 82 | |
| 83 | /** |
| 84 | * tipc_node_create - create neighboring node |
| 85 | * |
| 86 | * Currently, this routine is called by neighbor discovery code, which holds |
| 87 | * net_lock for reading only. We must take node_create_lock to ensure a node |
| 88 | * isn't created twice if two different bearers discover the node at the same |
| 89 | * time. (It would be preferable to switch to holding net_lock in write mode, |
| 90 | * but this is a non-trivial change.) |
| 91 | */ |
| 92 | struct tipc_node *tipc_node_create(u32 addr) |
| 93 | { |
| 94 | struct tipc_node *n_ptr, *temp_node; |
| 95 | |
| 96 | spin_lock_bh(&node_create_lock); |
| 97 | |
| 98 | n_ptr = tipc_node_find(addr); |
| 99 | if (n_ptr) { |
| 100 | spin_unlock_bh(&node_create_lock); |
| 101 | return n_ptr; |
| 102 | } |
| 103 | |
| 104 | n_ptr = kzalloc(sizeof(*n_ptr), GFP_ATOMIC); |
| 105 | if (!n_ptr) { |
| 106 | spin_unlock_bh(&node_create_lock); |
| 107 | pr_warn("Node creation failed, no memory\n"); |
| 108 | return NULL; |
| 109 | } |
| 110 | |
| 111 | n_ptr->addr = addr; |
| 112 | spin_lock_init(&n_ptr->lock); |
| 113 | INIT_HLIST_NODE(&n_ptr->hash); |
| 114 | INIT_LIST_HEAD(&n_ptr->list); |
| 115 | INIT_LIST_HEAD(&n_ptr->nsub); |
| 116 | |
| 117 | hlist_add_head(&n_ptr->hash, &node_htable[tipc_hashfn(addr)]); |
| 118 | |
| 119 | list_for_each_entry(temp_node, &tipc_node_list, list) { |
| 120 | if (n_ptr->addr < temp_node->addr) |
| 121 | break; |
| 122 | } |
| 123 | list_add_tail(&n_ptr->list, &temp_node->list); |
| 124 | n_ptr->block_setup = WAIT_PEER_DOWN; |
| 125 | n_ptr->signature = INVALID_NODE_SIG; |
| 126 | |
| 127 | tipc_num_nodes++; |
| 128 | |
| 129 | spin_unlock_bh(&node_create_lock); |
| 130 | return n_ptr; |
| 131 | } |
| 132 | |
| 133 | void tipc_node_delete(struct tipc_node *n_ptr) |
| 134 | { |
| 135 | list_del(&n_ptr->list); |
| 136 | hlist_del(&n_ptr->hash); |
| 137 | kfree(n_ptr); |
| 138 | |
| 139 | tipc_num_nodes--; |
| 140 | } |
| 141 | |
| 142 | /** |
| 143 | * tipc_node_link_up - handle addition of link |
| 144 | * |
| 145 | * Link becomes active (alone or shared) or standby, depending on its priority. |
| 146 | */ |
| 147 | void tipc_node_link_up(struct tipc_node *n_ptr, struct tipc_link *l_ptr) |
| 148 | { |
| 149 | struct tipc_link **active = &n_ptr->active_links[0]; |
| 150 | |
| 151 | n_ptr->working_links++; |
| 152 | |
| 153 | pr_info("Established link <%s> on network plane %c\n", |
| 154 | l_ptr->name, l_ptr->b_ptr->net_plane); |
| 155 | |
| 156 | if (!active[0]) { |
| 157 | active[0] = active[1] = l_ptr; |
| 158 | node_established_contact(n_ptr); |
| 159 | return; |
| 160 | } |
| 161 | if (l_ptr->priority < active[0]->priority) { |
| 162 | pr_info("New link <%s> becomes standby\n", l_ptr->name); |
| 163 | return; |
| 164 | } |
| 165 | tipc_link_send_duplicate(active[0], l_ptr); |
| 166 | if (l_ptr->priority == active[0]->priority) { |
| 167 | active[0] = l_ptr; |
| 168 | return; |
| 169 | } |
| 170 | pr_info("Old link <%s> becomes standby\n", active[0]->name); |
| 171 | if (active[1] != active[0]) |
| 172 | pr_info("Old link <%s> becomes standby\n", active[1]->name); |
| 173 | active[0] = active[1] = l_ptr; |
| 174 | } |
| 175 | |
| 176 | /** |
| 177 | * node_select_active_links - select active link |
| 178 | */ |
| 179 | static void node_select_active_links(struct tipc_node *n_ptr) |
| 180 | { |
| 181 | struct tipc_link **active = &n_ptr->active_links[0]; |
| 182 | u32 i; |
| 183 | u32 highest_prio = 0; |
| 184 | |
| 185 | active[0] = active[1] = NULL; |
| 186 | |
| 187 | for (i = 0; i < MAX_BEARERS; i++) { |
| 188 | struct tipc_link *l_ptr = n_ptr->links[i]; |
| 189 | |
| 190 | if (!l_ptr || !tipc_link_is_up(l_ptr) || |
| 191 | (l_ptr->priority < highest_prio)) |
| 192 | continue; |
| 193 | |
| 194 | if (l_ptr->priority > highest_prio) { |
| 195 | highest_prio = l_ptr->priority; |
| 196 | active[0] = active[1] = l_ptr; |
| 197 | } else { |
| 198 | active[1] = l_ptr; |
| 199 | } |
| 200 | } |
| 201 | } |
| 202 | |
| 203 | /** |
| 204 | * tipc_node_link_down - handle loss of link |
| 205 | */ |
| 206 | void tipc_node_link_down(struct tipc_node *n_ptr, struct tipc_link *l_ptr) |
| 207 | { |
| 208 | struct tipc_link **active; |
| 209 | |
| 210 | n_ptr->working_links--; |
| 211 | |
| 212 | if (!tipc_link_is_active(l_ptr)) { |
| 213 | pr_info("Lost standby link <%s> on network plane %c\n", |
| 214 | l_ptr->name, l_ptr->b_ptr->net_plane); |
| 215 | return; |
| 216 | } |
| 217 | pr_info("Lost link <%s> on network plane %c\n", |
| 218 | l_ptr->name, l_ptr->b_ptr->net_plane); |
| 219 | |
| 220 | active = &n_ptr->active_links[0]; |
| 221 | if (active[0] == l_ptr) |
| 222 | active[0] = active[1]; |
| 223 | if (active[1] == l_ptr) |
| 224 | active[1] = active[0]; |
| 225 | if (active[0] == l_ptr) |
| 226 | node_select_active_links(n_ptr); |
| 227 | if (tipc_node_is_up(n_ptr)) |
| 228 | tipc_link_changeover(l_ptr); |
| 229 | else |
| 230 | node_lost_contact(n_ptr); |
| 231 | } |
| 232 | |
| 233 | int tipc_node_active_links(struct tipc_node *n_ptr) |
| 234 | { |
| 235 | return n_ptr->active_links[0] != NULL; |
| 236 | } |
| 237 | |
| 238 | int tipc_node_redundant_links(struct tipc_node *n_ptr) |
| 239 | { |
| 240 | return n_ptr->working_links > 1; |
| 241 | } |
| 242 | |
| 243 | int tipc_node_is_up(struct tipc_node *n_ptr) |
| 244 | { |
| 245 | return tipc_node_active_links(n_ptr); |
| 246 | } |
| 247 | |
| 248 | void tipc_node_attach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr) |
| 249 | { |
| 250 | n_ptr->links[l_ptr->b_ptr->identity] = l_ptr; |
| 251 | atomic_inc(&tipc_num_links); |
| 252 | n_ptr->link_cnt++; |
| 253 | } |
| 254 | |
| 255 | void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr) |
| 256 | { |
| 257 | n_ptr->links[l_ptr->b_ptr->identity] = NULL; |
| 258 | atomic_dec(&tipc_num_links); |
| 259 | n_ptr->link_cnt--; |
| 260 | } |
| 261 | |
| 262 | static void node_established_contact(struct tipc_node *n_ptr) |
| 263 | { |
| 264 | tipc_k_signal((Handler)tipc_named_node_up, n_ptr->addr); |
| 265 | n_ptr->bclink.oos_state = 0; |
| 266 | n_ptr->bclink.acked = tipc_bclink_get_last_sent(); |
| 267 | tipc_bclink_add_node(n_ptr->addr); |
| 268 | } |
| 269 | |
| 270 | static void node_name_purge_complete(unsigned long node_addr) |
| 271 | { |
| 272 | struct tipc_node *n_ptr; |
| 273 | |
| 274 | read_lock_bh(&tipc_net_lock); |
| 275 | n_ptr = tipc_node_find(node_addr); |
| 276 | if (n_ptr) { |
| 277 | tipc_node_lock(n_ptr); |
| 278 | n_ptr->block_setup &= ~WAIT_NAMES_GONE; |
| 279 | tipc_node_unlock(n_ptr); |
| 280 | } |
| 281 | read_unlock_bh(&tipc_net_lock); |
| 282 | } |
| 283 | |
| 284 | static void node_lost_contact(struct tipc_node *n_ptr) |
| 285 | { |
| 286 | char addr_string[16]; |
| 287 | u32 i; |
| 288 | |
| 289 | pr_info("Lost contact with %s\n", |
| 290 | tipc_addr_string_fill(addr_string, n_ptr->addr)); |
| 291 | |
| 292 | /* Flush broadcast link info associated with lost node */ |
| 293 | if (n_ptr->bclink.recv_permitted) { |
| 294 | while (n_ptr->bclink.deferred_head) { |
| 295 | struct sk_buff *buf = n_ptr->bclink.deferred_head; |
| 296 | n_ptr->bclink.deferred_head = buf->next; |
| 297 | kfree_skb(buf); |
| 298 | } |
| 299 | n_ptr->bclink.deferred_size = 0; |
| 300 | |
| 301 | if (n_ptr->bclink.defragm) { |
| 302 | kfree_skb(n_ptr->bclink.defragm); |
| 303 | n_ptr->bclink.defragm = NULL; |
| 304 | } |
| 305 | |
| 306 | tipc_bclink_remove_node(n_ptr->addr); |
| 307 | tipc_bclink_acknowledge(n_ptr, INVALID_LINK_SEQ); |
| 308 | |
| 309 | n_ptr->bclink.recv_permitted = false; |
| 310 | } |
| 311 | |
| 312 | /* Abort link changeover */ |
| 313 | for (i = 0; i < MAX_BEARERS; i++) { |
| 314 | struct tipc_link *l_ptr = n_ptr->links[i]; |
| 315 | if (!l_ptr) |
| 316 | continue; |
| 317 | l_ptr->reset_checkpoint = l_ptr->next_in_no; |
| 318 | l_ptr->exp_msg_count = 0; |
| 319 | tipc_link_reset_fragments(l_ptr); |
| 320 | } |
| 321 | |
| 322 | /* Notify subscribers */ |
| 323 | tipc_nodesub_notify(n_ptr); |
| 324 | |
| 325 | /* Prevent re-contact with node until cleanup is done */ |
| 326 | n_ptr->block_setup = WAIT_PEER_DOWN | WAIT_NAMES_GONE; |
| 327 | tipc_k_signal((Handler)node_name_purge_complete, n_ptr->addr); |
| 328 | } |
| 329 | |
| 330 | struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space) |
| 331 | { |
| 332 | u32 domain; |
| 333 | struct sk_buff *buf; |
| 334 | struct tipc_node *n_ptr; |
| 335 | struct tipc_node_info node_info; |
| 336 | u32 payload_size; |
| 337 | |
| 338 | if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR)) |
| 339 | return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR); |
| 340 | |
| 341 | domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area)); |
| 342 | if (!tipc_addr_domain_valid(domain)) |
| 343 | return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE |
| 344 | " (network address)"); |
| 345 | |
| 346 | read_lock_bh(&tipc_net_lock); |
| 347 | if (!tipc_num_nodes) { |
| 348 | read_unlock_bh(&tipc_net_lock); |
| 349 | return tipc_cfg_reply_none(); |
| 350 | } |
| 351 | |
| 352 | /* For now, get space for all other nodes */ |
| 353 | payload_size = TLV_SPACE(sizeof(node_info)) * tipc_num_nodes; |
| 354 | if (payload_size > 32768u) { |
| 355 | read_unlock_bh(&tipc_net_lock); |
| 356 | return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED |
| 357 | " (too many nodes)"); |
| 358 | } |
| 359 | buf = tipc_cfg_reply_alloc(payload_size); |
| 360 | if (!buf) { |
| 361 | read_unlock_bh(&tipc_net_lock); |
| 362 | return NULL; |
| 363 | } |
| 364 | |
| 365 | /* Add TLVs for all nodes in scope */ |
| 366 | list_for_each_entry(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 | |
| 375 | read_unlock_bh(&tipc_net_lock); |
| 376 | return buf; |
| 377 | } |
| 378 | |
| 379 | struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space) |
| 380 | { |
| 381 | u32 domain; |
| 382 | struct sk_buff *buf; |
| 383 | struct tipc_node *n_ptr; |
| 384 | struct tipc_link_info link_info; |
| 385 | u32 payload_size; |
| 386 | |
| 387 | if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR)) |
| 388 | return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR); |
| 389 | |
| 390 | domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area)); |
| 391 | if (!tipc_addr_domain_valid(domain)) |
| 392 | return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE |
| 393 | " (network address)"); |
| 394 | |
| 395 | if (!tipc_own_addr) |
| 396 | return tipc_cfg_reply_none(); |
| 397 | |
| 398 | read_lock_bh(&tipc_net_lock); |
| 399 | |
| 400 | /* Get space for all unicast links + broadcast link */ |
| 401 | payload_size = TLV_SPACE(sizeof(link_info)) * |
| 402 | (atomic_read(&tipc_num_links) + 1); |
| 403 | if (payload_size > 32768u) { |
| 404 | read_unlock_bh(&tipc_net_lock); |
| 405 | return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED |
| 406 | " (too many links)"); |
| 407 | } |
| 408 | buf = tipc_cfg_reply_alloc(payload_size); |
| 409 | if (!buf) { |
| 410 | read_unlock_bh(&tipc_net_lock); |
| 411 | return NULL; |
| 412 | } |
| 413 | |
| 414 | /* Add TLV for broadcast link */ |
| 415 | link_info.dest = htonl(tipc_cluster_mask(tipc_own_addr)); |
| 416 | link_info.up = htonl(1); |
| 417 | strlcpy(link_info.str, tipc_bclink_name, TIPC_MAX_LINK_NAME); |
| 418 | tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO, &link_info, sizeof(link_info)); |
| 419 | |
| 420 | /* Add TLVs for any other links in scope */ |
| 421 | list_for_each_entry(n_ptr, &tipc_node_list, list) { |
| 422 | u32 i; |
| 423 | |
| 424 | if (!tipc_in_scope(domain, n_ptr->addr)) |
| 425 | continue; |
| 426 | tipc_node_lock(n_ptr); |
| 427 | for (i = 0; i < MAX_BEARERS; i++) { |
| 428 | if (!n_ptr->links[i]) |
| 429 | continue; |
| 430 | link_info.dest = htonl(n_ptr->addr); |
| 431 | link_info.up = htonl(tipc_link_is_up(n_ptr->links[i])); |
| 432 | strcpy(link_info.str, n_ptr->links[i]->name); |
| 433 | tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO, |
| 434 | &link_info, sizeof(link_info)); |
| 435 | } |
| 436 | tipc_node_unlock(n_ptr); |
| 437 | } |
| 438 | |
| 439 | read_unlock_bh(&tipc_net_lock); |
| 440 | return buf; |
| 441 | } |