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 */ 62 struct 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 */ 81 static 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 } 101 102 static 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 */ 126 static 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 */ 141 static 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 */ 193 void 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 skb_linearize(skb); 215 hdr = buf_msg(skb); 216 217 if (caps & TIPC_NODE_ID128) 218 memcpy(peer_id, msg_node_id(hdr), NODE_ID_LEN); 219 else 220 sprintf(peer_id, "%x", src); 221 222 err = b->media->msg2addr(b, &maddr, msg_media_addr(hdr)); 223 kfree_skb(skb); 224 if (err || maddr.broadcast) { 225 pr_warn_ratelimited("Rcv corrupt discovery message\n"); 226 return; 227 } 228 /* Ignore discovery messages from own node */ 229 if (!memcmp(&maddr, &b->addr, sizeof(maddr))) 230 return; 231 if (net_id != tn->net_id) 232 return; 233 if (tipc_disc_addr_trial_msg(b->disc, &maddr, b, dst, 234 src, sugg, peer_id, mtyp)) 235 return; 236 self = tipc_own_addr(net); 237 238 /* Message from somebody using this node's address */ 239 if (in_own_node(net, src)) { 240 disc_dupl_alert(b, self, &maddr); 241 return; 242 } 243 if (!tipc_in_scope(legacy, dst, self)) 244 return; 245 if (!tipc_in_scope(legacy, b->domain, src)) 246 return; 247 tipc_node_check_dest(net, src, peer_id, b, caps, signature, pnet_hash, 248 &maddr, &respond, &dupl_addr); 249 if (dupl_addr) 250 disc_dupl_alert(b, src, &maddr); 251 if (!respond) 252 return; 253 if (mtyp != DSC_REQ_MSG) 254 return; 255 tipc_disc_msg_xmit(net, DSC_RESP_MSG, src, self, 0, &maddr, b); 256 } 257 258 /* tipc_disc_add_dest - increment set of discovered nodes 259 */ 260 void tipc_disc_add_dest(struct tipc_discoverer *d) 261 { 262 spin_lock_bh(&d->lock); 263 d->num_nodes++; 264 spin_unlock_bh(&d->lock); 265 } 266 267 /* tipc_disc_remove_dest - decrement set of discovered nodes 268 */ 269 void tipc_disc_remove_dest(struct tipc_discoverer *d) 270 { 271 int intv, num; 272 273 spin_lock_bh(&d->lock); 274 d->num_nodes--; 275 num = d->num_nodes; 276 intv = d->timer_intv; 277 if (!num && (intv == TIPC_DISC_INACTIVE || intv > TIPC_DISC_FAST)) { 278 d->timer_intv = TIPC_DISC_INIT; 279 mod_timer(&d->timer, jiffies + d->timer_intv); 280 } 281 spin_unlock_bh(&d->lock); 282 } 283 284 /* tipc_disc_timeout - send a periodic link setup request 285 * Called whenever a link setup request timer associated with a bearer expires. 286 * - Keep doubling time between sent request until limit is reached; 287 * - Hold at fast polling rate if we don't have any associated nodes 288 * - Otherwise hold at slow polling rate 289 */ 290 static void tipc_disc_timeout(struct timer_list *t) 291 { 292 struct tipc_discoverer *d = from_timer(d, t, timer); 293 struct tipc_net *tn = tipc_net(d->net); 294 struct tipc_media_addr maddr; 295 struct sk_buff *skb = NULL; 296 struct net *net = d->net; 297 u32 bearer_id; 298 299 spin_lock_bh(&d->lock); 300 301 /* Stop searching if only desired node has been found */ 302 if (tipc_node(d->domain) && d->num_nodes) { 303 d->timer_intv = TIPC_DISC_INACTIVE; 304 goto exit; 305 } 306 307 /* Did we just leave trial period ? */ 308 if (!time_before(jiffies, tn->addr_trial_end) && !tipc_own_addr(net)) { 309 mod_timer(&d->timer, jiffies + TIPC_DISC_INIT); 310 spin_unlock_bh(&d->lock); 311 schedule_work(&tn->work); 312 return; 313 } 314 315 /* Adjust timeout interval according to discovery phase */ 316 if (time_before(jiffies, tn->addr_trial_end)) { 317 d->timer_intv = TIPC_DISC_INIT; 318 } else { 319 d->timer_intv *= 2; 320 if (d->num_nodes && d->timer_intv > TIPC_DISC_SLOW) 321 d->timer_intv = TIPC_DISC_SLOW; 322 else if (!d->num_nodes && d->timer_intv > TIPC_DISC_FAST) 323 d->timer_intv = TIPC_DISC_FAST; 324 msg_set_type(buf_msg(d->skb), DSC_REQ_MSG); 325 msg_set_prevnode(buf_msg(d->skb), tn->trial_addr); 326 } 327 328 mod_timer(&d->timer, jiffies + d->timer_intv); 329 memcpy(&maddr, &d->dest, sizeof(maddr)); 330 skb = skb_clone(d->skb, GFP_ATOMIC); 331 bearer_id = d->bearer_id; 332 exit: 333 spin_unlock_bh(&d->lock); 334 if (skb) 335 tipc_bearer_xmit_skb(net, bearer_id, skb, &maddr); 336 } 337 338 /** 339 * tipc_disc_create - create object to send periodic link setup requests 340 * @net: the applicable net namespace 341 * @b: ptr to bearer issuing requests 342 * @dest: destination address for request messages 343 * @skb: pointer to created frame 344 * 345 * Return: 0 if successful, otherwise -errno. 346 */ 347 int tipc_disc_create(struct net *net, struct tipc_bearer *b, 348 struct tipc_media_addr *dest, struct sk_buff **skb) 349 { 350 struct tipc_net *tn = tipc_net(net); 351 struct tipc_discoverer *d; 352 353 d = kmalloc(sizeof(*d), GFP_ATOMIC); 354 if (!d) 355 return -ENOMEM; 356 d->skb = tipc_buf_acquire(MAX_H_SIZE + NODE_ID_LEN, GFP_ATOMIC); 357 if (!d->skb) { 358 kfree(d); 359 return -ENOMEM; 360 } 361 tipc_disc_init_msg(net, d->skb, DSC_REQ_MSG, b); 362 363 /* Do we need an address trial period first ? */ 364 if (!tipc_own_addr(net)) { 365 tn->addr_trial_end = jiffies + msecs_to_jiffies(1000); 366 msg_set_type(buf_msg(d->skb), DSC_TRIAL_MSG); 367 } 368 memcpy(&d->dest, dest, sizeof(*dest)); 369 d->net = net; 370 d->bearer_id = b->identity; 371 d->domain = b->domain; 372 d->num_nodes = 0; 373 d->timer_intv = TIPC_DISC_INIT; 374 spin_lock_init(&d->lock); 375 timer_setup(&d->timer, tipc_disc_timeout, 0); 376 mod_timer(&d->timer, jiffies + d->timer_intv); 377 b->disc = d; 378 *skb = skb_clone(d->skb, GFP_ATOMIC); 379 return 0; 380 } 381 382 /** 383 * tipc_disc_delete - destroy object sending periodic link setup requests 384 * @d: ptr to link dest structure 385 */ 386 void tipc_disc_delete(struct tipc_discoverer *d) 387 { 388 del_timer_sync(&d->timer); 389 kfree_skb(d->skb); 390 kfree(d); 391 } 392 393 /** 394 * tipc_disc_reset - reset object to send periodic link setup requests 395 * @net: the applicable net namespace 396 * @b: ptr to bearer issuing requests 397 */ 398 void tipc_disc_reset(struct net *net, struct tipc_bearer *b) 399 { 400 struct tipc_discoverer *d = b->disc; 401 struct tipc_media_addr maddr; 402 struct sk_buff *skb; 403 404 spin_lock_bh(&d->lock); 405 tipc_disc_init_msg(net, d->skb, DSC_REQ_MSG, b); 406 d->net = net; 407 d->bearer_id = b->identity; 408 d->domain = b->domain; 409 d->num_nodes = 0; 410 d->timer_intv = TIPC_DISC_INIT; 411 memcpy(&maddr, &d->dest, sizeof(maddr)); 412 mod_timer(&d->timer, jiffies + d->timer_intv); 413 skb = skb_clone(d->skb, GFP_ATOMIC); 414 spin_unlock_bh(&d->lock); 415 if (skb) 416 tipc_bearer_xmit_skb(net, b->identity, skb, &maddr); 417 } 418