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