1/* 2 * net/tipc/discover.c 3 * 4 * Copyright (c) 2003-2006, 2014-2018, 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 "node.h" 39#include "discover.h" 40 41/* min delay during bearer start up */ 42#define TIPC_DISC_INIT msecs_to_jiffies(125) 43/* max delay if bearer has no links */ 44#define TIPC_DISC_FAST msecs_to_jiffies(1000) 45/* max delay if bearer has links */ 46#define TIPC_DISC_SLOW msecs_to_jiffies(60000) 47/* indicates no timer in use */ 48#define TIPC_DISC_INACTIVE 0xffffffff 49 50/** 51 * struct tipc_discoverer - information about an ongoing link setup request 52 * @bearer_id: identity of bearer issuing requests 53 * @net: network namespace instance 54 * @dest: destination address for request messages 55 * @domain: network domain to which links can be established 56 * @num_nodes: number of nodes currently discovered (i.e. with an active link) 57 * @lock: spinlock for controlling access to requests 58 * @skb: request message to be (repeatedly) sent 59 * @timer: timer governing period between requests 60 * @timer_intv: current interval between requests (in ms) 61 */ 62struct tipc_discoverer { 63 u32 bearer_id; 64 struct tipc_media_addr dest; 65 struct net *net; 66 u32 domain; 67 int num_nodes; 68 spinlock_t lock; 69 struct sk_buff *skb; 70 struct timer_list timer; 71 unsigned long timer_intv; 72}; 73 74/** 75 * tipc_disc_init_msg - initialize a link setup message 76 * @net: the applicable net namespace 77 * @skb: buffer containing message 78 * @mtyp: message type (request or response) 79 * @b: ptr to bearer issuing message 80 */ 81static void tipc_disc_init_msg(struct net *net, struct sk_buff *skb, 82 u32 mtyp, struct tipc_bearer *b) 83{ 84 struct tipc_net *tn = tipc_net(net); 85 u32 dest_domain = b->domain; 86 struct tipc_msg *hdr; 87 88 hdr = buf_msg(skb); 89 tipc_msg_init(tn->trial_addr, hdr, LINK_CONFIG, mtyp, 90 MAX_H_SIZE, dest_domain); 91 msg_set_size(hdr, MAX_H_SIZE + NODE_ID_LEN); 92 msg_set_non_seq(hdr, 1); 93 msg_set_node_sig(hdr, tn->random); 94 msg_set_node_capabilities(hdr, TIPC_NODE_CAPABILITIES); 95 msg_set_dest_domain(hdr, dest_domain); 96 msg_set_bc_netid(hdr, tn->net_id); 97 b->media->addr2msg(msg_media_addr(hdr), &b->addr); 98 msg_set_peer_net_hash(hdr, tipc_net_hash_mixes(net, tn->random)); 99 msg_set_node_id(hdr, tipc_own_id(net)); 100} 101 102static void tipc_disc_msg_xmit(struct net *net, u32 mtyp, u32 dst, 103 u32 src, u32 sugg_addr, 104 struct tipc_media_addr *maddr, 105 struct tipc_bearer *b) 106{ 107 struct tipc_msg *hdr; 108 struct sk_buff *skb; 109 110 skb = tipc_buf_acquire(MAX_H_SIZE + NODE_ID_LEN, GFP_ATOMIC); 111 if (!skb) 112 return; 113 hdr = buf_msg(skb); 114 tipc_disc_init_msg(net, skb, mtyp, b); 115 msg_set_sugg_node_addr(hdr, sugg_addr); 116 msg_set_dest_domain(hdr, dst); 117 tipc_bearer_xmit_skb(net, b->identity, skb, maddr); 118} 119 120/** 121 * disc_dupl_alert - issue node address duplication alert 122 * @b: pointer to bearer detecting duplication 123 * @node_addr: duplicated node address 124 * @media_addr: media address advertised by duplicated node 125 */ 126static void disc_dupl_alert(struct tipc_bearer *b, u32 node_addr, 127 struct tipc_media_addr *media_addr) 128{ 129 char media_addr_str[64]; 130 131 tipc_media_addr_printf(media_addr_str, sizeof(media_addr_str), 132 media_addr); 133 pr_warn("Duplicate %x using %s seen on <%s>\n", node_addr, 134 media_addr_str, b->name); 135} 136 137/* tipc_disc_addr_trial(): - handle an address uniqueness trial from peer 138 * Returns true if message should be dropped by caller, i.e., if it is a 139 * trial message or we are inside trial period. Otherwise false. 140 */ 141static bool tipc_disc_addr_trial_msg(struct tipc_discoverer *d, 142 struct tipc_media_addr *maddr, 143 struct tipc_bearer *b, 144 u32 dst, u32 src, 145 u32 sugg_addr, 146 u8 *peer_id, 147 int mtyp) 148{ 149 struct net *net = d->net; 150 struct tipc_net *tn = tipc_net(net); 151 u32 self = tipc_own_addr(net); 152 bool trial = time_before(jiffies, tn->addr_trial_end) && !self; 153 154 if (mtyp == DSC_TRIAL_FAIL_MSG) { 155 if (!trial) 156 return true; 157 158 /* Ignore if somebody else already gave new suggestion */ 159 if (dst != tn->trial_addr) 160 return true; 161 162 /* Otherwise update trial address and restart trial period */ 163 tn->trial_addr = sugg_addr; 164 msg_set_prevnode(buf_msg(d->skb), sugg_addr); 165 tn->addr_trial_end = jiffies + msecs_to_jiffies(1000); 166 return true; 167 } 168 169 /* Apply trial address if we just left trial period */ 170 if (!trial && !self) { 171 schedule_work(&tn->work); 172 msg_set_prevnode(buf_msg(d->skb), tn->trial_addr); 173 msg_set_type(buf_msg(d->skb), DSC_REQ_MSG); 174 } 175 176 /* Accept regular link requests/responses only after trial period */ 177 if (mtyp != DSC_TRIAL_MSG) 178 return trial; 179 180 sugg_addr = tipc_node_try_addr(net, peer_id, src); 181 if (sugg_addr) 182 tipc_disc_msg_xmit(net, DSC_TRIAL_FAIL_MSG, src, 183 self, sugg_addr, maddr, b); 184 return true; 185} 186 187/** 188 * tipc_disc_rcv - handle incoming discovery message (request or response) 189 * @net: applicable net namespace 190 * @skb: buffer containing message 191 * @b: bearer that message arrived on 192 */ 193void tipc_disc_rcv(struct net *net, struct sk_buff *skb, 194 struct tipc_bearer *b) 195{ 196 struct tipc_net *tn = tipc_net(net); 197 struct tipc_msg *hdr = buf_msg(skb); 198 u32 pnet_hash = msg_peer_net_hash(hdr); 199 u16 caps = msg_node_capabilities(hdr); 200 bool legacy = tn->legacy_addr_format; 201 u32 sugg = msg_sugg_node_addr(hdr); 202 u32 signature = msg_node_sig(hdr); 203 u8 peer_id[NODE_ID_LEN] = {0,}; 204 u32 dst = msg_dest_domain(hdr); 205 u32 net_id = msg_bc_netid(hdr); 206 struct tipc_media_addr maddr; 207 u32 src = msg_prevnode(hdr); 208 u32 mtyp = msg_type(hdr); 209 bool dupl_addr = false; 210 bool respond = false; 211 u32 self; 212 int err; 213 214 if (skb_linearize(skb)) { 215 kfree_skb(skb); 216 return; 217 } 218 hdr = buf_msg(skb); 219 220 if (caps & TIPC_NODE_ID128) 221 memcpy(peer_id, msg_node_id(hdr), NODE_ID_LEN); 222 else 223 sprintf(peer_id, "%x", src); 224 225 err = b->media->msg2addr(b, &maddr, msg_media_addr(hdr)); 226 kfree_skb(skb); 227 if (err || maddr.broadcast) { 228 pr_warn_ratelimited("Rcv corrupt discovery message\n"); 229 return; 230 } 231 /* Ignore discovery messages from own node */ 232 if (!memcmp(&maddr, &b->addr, sizeof(maddr))) 233 return; 234 if (net_id != tn->net_id) 235 return; 236 if (tipc_disc_addr_trial_msg(b->disc, &maddr, b, dst, 237 src, sugg, peer_id, mtyp)) 238 return; 239 self = tipc_own_addr(net); 240 241 /* Message from somebody using this node's address */ 242 if (in_own_node(net, src)) { 243 disc_dupl_alert(b, self, &maddr); 244 return; 245 } 246 if (!tipc_in_scope(legacy, dst, self)) 247 return; 248 if (!tipc_in_scope(legacy, b->domain, src)) 249 return; 250 tipc_node_check_dest(net, src, peer_id, b, caps, signature, pnet_hash, 251 &maddr, &respond, &dupl_addr); 252 if (dupl_addr) 253 disc_dupl_alert(b, src, &maddr); 254 if (!respond) 255 return; 256 if (mtyp != DSC_REQ_MSG) 257 return; 258 tipc_disc_msg_xmit(net, DSC_RESP_MSG, src, self, 0, &maddr, b); 259} 260 261/* tipc_disc_add_dest - increment set of discovered nodes 262 */ 263void tipc_disc_add_dest(struct tipc_discoverer *d) 264{ 265 spin_lock_bh(&d->lock); 266 d->num_nodes++; 267 spin_unlock_bh(&d->lock); 268} 269 270/* tipc_disc_remove_dest - decrement set of discovered nodes 271 */ 272void tipc_disc_remove_dest(struct tipc_discoverer *d) 273{ 274 int intv, num; 275 276 spin_lock_bh(&d->lock); 277 d->num_nodes--; 278 num = d->num_nodes; 279 intv = d->timer_intv; 280 if (!num && (intv == TIPC_DISC_INACTIVE || intv > TIPC_DISC_FAST)) { 281 d->timer_intv = TIPC_DISC_INIT; 282 mod_timer(&d->timer, jiffies + d->timer_intv); 283 } 284 spin_unlock_bh(&d->lock); 285} 286 287/* tipc_disc_timeout - send a periodic link setup request 288 * Called whenever a link setup request timer associated with a bearer expires. 289 * - Keep doubling time between sent request until limit is reached; 290 * - Hold at fast polling rate if we don't have any associated nodes 291 * - Otherwise hold at slow polling rate 292 */ 293static void tipc_disc_timeout(struct timer_list *t) 294{ 295 struct tipc_discoverer *d = from_timer(d, t, timer); 296 struct tipc_net *tn = tipc_net(d->net); 297 struct tipc_media_addr maddr; 298 struct sk_buff *skb = NULL; 299 struct net *net = d->net; 300 u32 bearer_id; 301 302 spin_lock_bh(&d->lock); 303 304 /* Stop searching if only desired node has been found */ 305 if (tipc_node(d->domain) && d->num_nodes) { 306 d->timer_intv = TIPC_DISC_INACTIVE; 307 goto exit; 308 } 309 310 /* Did we just leave trial period ? */ 311 if (!time_before(jiffies, tn->addr_trial_end) && !tipc_own_addr(net)) { 312 mod_timer(&d->timer, jiffies + TIPC_DISC_INIT); 313 spin_unlock_bh(&d->lock); 314 schedule_work(&tn->work); 315 return; 316 } 317 318 /* Adjust timeout interval according to discovery phase */ 319 if (time_before(jiffies, tn->addr_trial_end)) { 320 d->timer_intv = TIPC_DISC_INIT; 321 } else { 322 d->timer_intv *= 2; 323 if (d->num_nodes && d->timer_intv > TIPC_DISC_SLOW) 324 d->timer_intv = TIPC_DISC_SLOW; 325 else if (!d->num_nodes && d->timer_intv > TIPC_DISC_FAST) 326 d->timer_intv = TIPC_DISC_FAST; 327 msg_set_type(buf_msg(d->skb), DSC_REQ_MSG); 328 msg_set_prevnode(buf_msg(d->skb), tn->trial_addr); 329 } 330 331 mod_timer(&d->timer, jiffies + d->timer_intv); 332 memcpy(&maddr, &d->dest, sizeof(maddr)); 333 skb = skb_clone(d->skb, GFP_ATOMIC); 334 bearer_id = d->bearer_id; 335exit: 336 spin_unlock_bh(&d->lock); 337 if (skb) 338 tipc_bearer_xmit_skb(net, bearer_id, skb, &maddr); 339} 340 341/** 342 * tipc_disc_create - create object to send periodic link setup requests 343 * @net: the applicable net namespace 344 * @b: ptr to bearer issuing requests 345 * @dest: destination address for request messages 346 * @skb: pointer to created frame 347 * 348 * Return: 0 if successful, otherwise -errno. 349 */ 350int tipc_disc_create(struct net *net, struct tipc_bearer *b, 351 struct tipc_media_addr *dest, struct sk_buff **skb) 352{ 353 struct tipc_net *tn = tipc_net(net); 354 struct tipc_discoverer *d; 355 356 d = kmalloc(sizeof(*d), GFP_ATOMIC); 357 if (!d) 358 return -ENOMEM; 359 d->skb = tipc_buf_acquire(MAX_H_SIZE + NODE_ID_LEN, GFP_ATOMIC); 360 if (!d->skb) { 361 kfree(d); 362 return -ENOMEM; 363 } 364 tipc_disc_init_msg(net, d->skb, DSC_REQ_MSG, b); 365 366 /* Do we need an address trial period first ? */ 367 if (!tipc_own_addr(net)) { 368 tn->addr_trial_end = jiffies + msecs_to_jiffies(1000); 369 msg_set_type(buf_msg(d->skb), DSC_TRIAL_MSG); 370 } 371 memcpy(&d->dest, dest, sizeof(*dest)); 372 d->net = net; 373 d->bearer_id = b->identity; 374 d->domain = b->domain; 375 d->num_nodes = 0; 376 d->timer_intv = TIPC_DISC_INIT; 377 spin_lock_init(&d->lock); 378 timer_setup(&d->timer, tipc_disc_timeout, 0); 379 mod_timer(&d->timer, jiffies + d->timer_intv); 380 b->disc = d; 381 *skb = skb_clone(d->skb, GFP_ATOMIC); 382 return 0; 383} 384 385/** 386 * tipc_disc_delete - destroy object sending periodic link setup requests 387 * @d: ptr to link dest structure 388 */ 389void tipc_disc_delete(struct tipc_discoverer *d) 390{ 391 timer_shutdown_sync(&d->timer); 392 kfree_skb(d->skb); 393 kfree(d); 394} 395 396/** 397 * tipc_disc_reset - reset object to send periodic link setup requests 398 * @net: the applicable net namespace 399 * @b: ptr to bearer issuing requests 400 */ 401void tipc_disc_reset(struct net *net, struct tipc_bearer *b) 402{ 403 struct tipc_discoverer *d = b->disc; 404 struct tipc_media_addr maddr; 405 struct sk_buff *skb; 406 407 spin_lock_bh(&d->lock); 408 tipc_disc_init_msg(net, d->skb, DSC_REQ_MSG, b); 409 d->net = net; 410 d->bearer_id = b->identity; 411 d->domain = b->domain; 412 d->num_nodes = 0; 413 d->timer_intv = TIPC_DISC_INIT; 414 memcpy(&maddr, &d->dest, sizeof(maddr)); 415 mod_timer(&d->timer, jiffies + d->timer_intv); 416 skb = skb_clone(d->skb, GFP_ATOMIC); 417 spin_unlock_bh(&d->lock); 418 if (skb) 419 tipc_bearer_xmit_skb(net, b->identity, skb, &maddr); 420} 421