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_node_id(hdr, tipc_own_id(net)); 98 } 99 100 static void tipc_disc_msg_xmit(struct net *net, u32 mtyp, u32 dst, 101 u32 src, u32 sugg_addr, 102 struct tipc_media_addr *maddr, 103 struct tipc_bearer *b) 104 { 105 struct tipc_msg *hdr; 106 struct sk_buff *skb; 107 108 skb = tipc_buf_acquire(MAX_H_SIZE + NODE_ID_LEN, GFP_ATOMIC); 109 if (!skb) 110 return; 111 hdr = buf_msg(skb); 112 tipc_disc_init_msg(net, skb, mtyp, b); 113 msg_set_sugg_node_addr(hdr, sugg_addr); 114 msg_set_dest_domain(hdr, dst); 115 tipc_bearer_xmit_skb(net, b->identity, skb, maddr); 116 } 117 118 /** 119 * disc_dupl_alert - issue node address duplication alert 120 * @b: pointer to bearer detecting duplication 121 * @node_addr: duplicated node address 122 * @media_addr: media address advertised by duplicated node 123 */ 124 static void disc_dupl_alert(struct tipc_bearer *b, u32 node_addr, 125 struct tipc_media_addr *media_addr) 126 { 127 char media_addr_str[64]; 128 129 tipc_media_addr_printf(media_addr_str, sizeof(media_addr_str), 130 media_addr); 131 pr_warn("Duplicate %x using %s seen on <%s>\n", node_addr, 132 media_addr_str, b->name); 133 } 134 135 /* tipc_disc_addr_trial(): - handle an address uniqueness trial from peer 136 * Returns true if message should be dropped by caller, i.e., if it is a 137 * trial message or we are inside trial period. Otherwise false. 138 */ 139 static bool tipc_disc_addr_trial_msg(struct tipc_discoverer *d, 140 struct tipc_media_addr *maddr, 141 struct tipc_bearer *b, 142 u32 dst, u32 src, 143 u32 sugg_addr, 144 u8 *peer_id, 145 int mtyp) 146 { 147 struct net *net = d->net; 148 struct tipc_net *tn = tipc_net(net); 149 bool trial = time_before(jiffies, tn->addr_trial_end); 150 u32 self = tipc_own_addr(net); 151 152 if (mtyp == DSC_TRIAL_FAIL_MSG) { 153 if (!trial) 154 return true; 155 156 /* Ignore if somebody else already gave new suggestion */ 157 if (dst != tn->trial_addr) 158 return true; 159 160 /* Otherwise update trial address and restart trial period */ 161 tn->trial_addr = sugg_addr; 162 msg_set_prevnode(buf_msg(d->skb), sugg_addr); 163 tn->addr_trial_end = jiffies + msecs_to_jiffies(1000); 164 return true; 165 } 166 167 /* Apply trial address if we just left trial period */ 168 if (!trial && !self) { 169 tipc_net_finalize(net, tn->trial_addr); 170 msg_set_type(buf_msg(d->skb), DSC_REQ_MSG); 171 } 172 173 /* Accept regular link requests/responses only after trial period */ 174 if (mtyp != DSC_TRIAL_MSG) 175 return trial; 176 177 sugg_addr = tipc_node_try_addr(net, peer_id, src); 178 if (sugg_addr) 179 tipc_disc_msg_xmit(net, DSC_TRIAL_FAIL_MSG, src, 180 self, sugg_addr, maddr, b); 181 return true; 182 } 183 184 /** 185 * tipc_disc_rcv - handle incoming discovery message (request or response) 186 * @net: applicable net namespace 187 * @skb: buffer containing message 188 * @b: bearer that message arrived on 189 */ 190 void tipc_disc_rcv(struct net *net, struct sk_buff *skb, 191 struct tipc_bearer *b) 192 { 193 struct tipc_net *tn = tipc_net(net); 194 struct tipc_msg *hdr = buf_msg(skb); 195 u16 caps = msg_node_capabilities(hdr); 196 bool legacy = tn->legacy_addr_format; 197 u32 sugg = msg_sugg_node_addr(hdr); 198 u32 signature = msg_node_sig(hdr); 199 u8 peer_id[NODE_ID_LEN] = {0,}; 200 u32 dst = msg_dest_domain(hdr); 201 u32 net_id = msg_bc_netid(hdr); 202 struct tipc_media_addr maddr; 203 u32 src = msg_prevnode(hdr); 204 u32 mtyp = msg_type(hdr); 205 bool dupl_addr = false; 206 bool respond = false; 207 u32 self; 208 int err; 209 210 skb_linearize(skb); 211 hdr = buf_msg(skb); 212 213 if (caps & TIPC_NODE_ID128) 214 memcpy(peer_id, msg_node_id(hdr), NODE_ID_LEN); 215 else 216 sprintf(peer_id, "%x", src); 217 218 err = b->media->msg2addr(b, &maddr, msg_media_addr(hdr)); 219 kfree_skb(skb); 220 if (err || maddr.broadcast) { 221 pr_warn_ratelimited("Rcv corrupt discovery message\n"); 222 return; 223 } 224 /* Ignore discovery messages from own node */ 225 if (!memcmp(&maddr, &b->addr, sizeof(maddr))) 226 return; 227 if (net_id != tn->net_id) 228 return; 229 if (tipc_disc_addr_trial_msg(b->disc, &maddr, b, dst, 230 src, sugg, peer_id, mtyp)) 231 return; 232 self = tipc_own_addr(net); 233 234 /* Message from somebody using this node's address */ 235 if (in_own_node(net, src)) { 236 disc_dupl_alert(b, self, &maddr); 237 return; 238 } 239 if (!tipc_in_scope(legacy, dst, self)) 240 return; 241 if (!tipc_in_scope(legacy, b->domain, src)) 242 return; 243 tipc_node_check_dest(net, src, peer_id, b, caps, signature, 244 &maddr, &respond, &dupl_addr); 245 if (dupl_addr) 246 disc_dupl_alert(b, src, &maddr); 247 if (!respond) 248 return; 249 if (mtyp != DSC_REQ_MSG) 250 return; 251 tipc_disc_msg_xmit(net, DSC_RESP_MSG, src, self, 0, &maddr, b); 252 } 253 254 /* tipc_disc_add_dest - increment set of discovered nodes 255 */ 256 void tipc_disc_add_dest(struct tipc_discoverer *d) 257 { 258 spin_lock_bh(&d->lock); 259 d->num_nodes++; 260 spin_unlock_bh(&d->lock); 261 } 262 263 /* tipc_disc_remove_dest - decrement set of discovered nodes 264 */ 265 void tipc_disc_remove_dest(struct tipc_discoverer *d) 266 { 267 int intv, num; 268 269 spin_lock_bh(&d->lock); 270 d->num_nodes--; 271 num = d->num_nodes; 272 intv = d->timer_intv; 273 if (!num && (intv == TIPC_DISC_INACTIVE || intv > TIPC_DISC_FAST)) { 274 d->timer_intv = TIPC_DISC_INIT; 275 mod_timer(&d->timer, jiffies + d->timer_intv); 276 } 277 spin_unlock_bh(&d->lock); 278 } 279 280 /* tipc_disc_timeout - send a periodic link setup request 281 * Called whenever a link setup request timer associated with a bearer expires. 282 * - Keep doubling time between sent request until limit is reached; 283 * - Hold at fast polling rate if we don't have any associated nodes 284 * - Otherwise hold at slow polling rate 285 */ 286 static void tipc_disc_timeout(struct timer_list *t) 287 { 288 struct tipc_discoverer *d = from_timer(d, t, timer); 289 struct tipc_net *tn = tipc_net(d->net); 290 struct tipc_media_addr maddr; 291 struct sk_buff *skb = NULL; 292 struct net *net = d->net; 293 u32 bearer_id; 294 295 spin_lock_bh(&d->lock); 296 297 /* Stop searching if only desired node has been found */ 298 if (tipc_node(d->domain) && d->num_nodes) { 299 d->timer_intv = TIPC_DISC_INACTIVE; 300 goto exit; 301 } 302 303 /* Trial period over ? */ 304 if (!time_before(jiffies, tn->addr_trial_end)) { 305 /* Did we just leave it ? */ 306 if (!tipc_own_addr(net)) 307 tipc_net_finalize(net, tn->trial_addr); 308 309 msg_set_type(buf_msg(d->skb), DSC_REQ_MSG); 310 msg_set_prevnode(buf_msg(d->skb), tipc_own_addr(net)); 311 } 312 313 /* Adjust timeout interval according to discovery phase */ 314 if (time_before(jiffies, tn->addr_trial_end)) { 315 d->timer_intv = TIPC_DISC_INIT; 316 } else { 317 d->timer_intv *= 2; 318 if (d->num_nodes && d->timer_intv > TIPC_DISC_SLOW) 319 d->timer_intv = TIPC_DISC_SLOW; 320 else if (!d->num_nodes && d->timer_intv > TIPC_DISC_FAST) 321 d->timer_intv = TIPC_DISC_FAST; 322 } 323 324 mod_timer(&d->timer, jiffies + d->timer_intv); 325 memcpy(&maddr, &d->dest, sizeof(maddr)); 326 skb = skb_clone(d->skb, GFP_ATOMIC); 327 bearer_id = d->bearer_id; 328 exit: 329 spin_unlock_bh(&d->lock); 330 if (skb) 331 tipc_bearer_xmit_skb(net, bearer_id, skb, &maddr); 332 } 333 334 /** 335 * tipc_disc_create - create object to send periodic link setup requests 336 * @net: the applicable net namespace 337 * @b: ptr to bearer issuing requests 338 * @dest: destination address for request messages 339 * @dest_domain: network domain to which links can be established 340 * 341 * Returns 0 if successful, otherwise -errno. 342 */ 343 int tipc_disc_create(struct net *net, struct tipc_bearer *b, 344 struct tipc_media_addr *dest, struct sk_buff **skb) 345 { 346 struct tipc_net *tn = tipc_net(net); 347 struct tipc_discoverer *d; 348 349 d = kmalloc(sizeof(*d), GFP_ATOMIC); 350 if (!d) 351 return -ENOMEM; 352 d->skb = tipc_buf_acquire(MAX_H_SIZE + NODE_ID_LEN, GFP_ATOMIC); 353 if (!d->skb) { 354 kfree(d); 355 return -ENOMEM; 356 } 357 tipc_disc_init_msg(net, d->skb, DSC_REQ_MSG, b); 358 359 /* Do we need an address trial period first ? */ 360 if (!tipc_own_addr(net)) { 361 tn->addr_trial_end = jiffies + msecs_to_jiffies(1000); 362 msg_set_type(buf_msg(d->skb), DSC_TRIAL_MSG); 363 } 364 memcpy(&d->dest, dest, sizeof(*dest)); 365 d->net = net; 366 d->bearer_id = b->identity; 367 d->domain = b->domain; 368 d->num_nodes = 0; 369 d->timer_intv = TIPC_DISC_INIT; 370 spin_lock_init(&d->lock); 371 timer_setup(&d->timer, tipc_disc_timeout, 0); 372 mod_timer(&d->timer, jiffies + d->timer_intv); 373 b->disc = d; 374 *skb = skb_clone(d->skb, GFP_ATOMIC); 375 return 0; 376 } 377 378 /** 379 * tipc_disc_delete - destroy object sending periodic link setup requests 380 * @d: ptr to link duest structure 381 */ 382 void tipc_disc_delete(struct tipc_discoverer *d) 383 { 384 del_timer_sync(&d->timer); 385 kfree_skb(d->skb); 386 kfree(d); 387 } 388 389 /** 390 * tipc_disc_reset - reset object to send periodic link setup requests 391 * @net: the applicable net namespace 392 * @b: ptr to bearer issuing requests 393 * @dest_domain: network domain to which links can be established 394 */ 395 void tipc_disc_reset(struct net *net, struct tipc_bearer *b) 396 { 397 struct tipc_discoverer *d = b->disc; 398 struct tipc_media_addr maddr; 399 struct sk_buff *skb; 400 401 spin_lock_bh(&d->lock); 402 tipc_disc_init_msg(net, d->skb, DSC_REQ_MSG, b); 403 d->net = net; 404 d->bearer_id = b->identity; 405 d->domain = b->domain; 406 d->num_nodes = 0; 407 d->timer_intv = TIPC_DISC_INIT; 408 memcpy(&maddr, &d->dest, sizeof(maddr)); 409 mod_timer(&d->timer, jiffies + d->timer_intv); 410 skb = skb_clone(d->skb, GFP_ATOMIC); 411 spin_unlock_bh(&d->lock); 412 if (skb) 413 tipc_bearer_xmit_skb(net, b->identity, skb, &maddr); 414 } 415