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