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 * @mtyp: message type (request or response) 78 * @b: ptr to bearer issuing message 79 */ 80static 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 101static 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 */ 125static 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 */ 140static 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 u32 self = tipc_own_addr(net); 151 bool trial = time_before(jiffies, tn->addr_trial_end) && !self; 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 schedule_work(&tn->work); 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 */ 192void 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 u32 pnet_hash = msg_peer_net_hash(hdr); 198 u16 caps = msg_node_capabilities(hdr); 199 bool legacy = tn->legacy_addr_format; 200 u32 sugg = msg_sugg_node_addr(hdr); 201 u32 signature = msg_node_sig(hdr); 202 u8 peer_id[NODE_ID_LEN] = {0,}; 203 u32 dst = msg_dest_domain(hdr); 204 u32 net_id = msg_bc_netid(hdr); 205 struct tipc_media_addr maddr; 206 u32 src = msg_prevnode(hdr); 207 u32 mtyp = msg_type(hdr); 208 bool dupl_addr = false; 209 bool respond = false; 210 u32 self; 211 int err; 212 213 if (skb_linearize(skb)) { 214 kfree_skb(skb); 215 return; 216 } 217 hdr = buf_msg(skb); 218 219 if (caps & TIPC_NODE_ID128) 220 memcpy(peer_id, msg_node_id(hdr), NODE_ID_LEN); 221 else 222 sprintf(peer_id, "%x", src); 223 224 err = b->media->msg2addr(b, &maddr, msg_media_addr(hdr)); 225 kfree_skb(skb); 226 if (err || maddr.broadcast) { 227 pr_warn_ratelimited("Rcv corrupt discovery message\n"); 228 return; 229 } 230 /* Ignore discovery messages from own node */ 231 if (!memcmp(&maddr, &b->addr, sizeof(maddr))) 232 return; 233 if (net_id != tn->net_id) 234 return; 235 if (tipc_disc_addr_trial_msg(b->disc, &maddr, b, dst, 236 src, sugg, peer_id, mtyp)) 237 return; 238 self = tipc_own_addr(net); 239 240 /* Message from somebody using this node's address */ 241 if (in_own_node(net, src)) { 242 disc_dupl_alert(b, self, &maddr); 243 return; 244 } 245 if (!tipc_in_scope(legacy, dst, self)) 246 return; 247 if (!tipc_in_scope(legacy, b->domain, src)) 248 return; 249 tipc_node_check_dest(net, src, peer_id, b, caps, signature, pnet_hash, 250 &maddr, &respond, &dupl_addr); 251 if (dupl_addr) 252 disc_dupl_alert(b, src, &maddr); 253 if (!respond) 254 return; 255 if (mtyp != DSC_REQ_MSG) 256 return; 257 tipc_disc_msg_xmit(net, DSC_RESP_MSG, src, self, 0, &maddr, b); 258} 259 260/* tipc_disc_add_dest - increment set of discovered nodes 261 */ 262void tipc_disc_add_dest(struct tipc_discoverer *d) 263{ 264 spin_lock_bh(&d->lock); 265 d->num_nodes++; 266 spin_unlock_bh(&d->lock); 267} 268 269/* tipc_disc_remove_dest - decrement set of discovered nodes 270 */ 271void tipc_disc_remove_dest(struct tipc_discoverer *d) 272{ 273 int intv, num; 274 275 spin_lock_bh(&d->lock); 276 d->num_nodes--; 277 num = d->num_nodes; 278 intv = d->timer_intv; 279 if (!num && (intv == TIPC_DISC_INACTIVE || intv > TIPC_DISC_FAST)) { 280 d->timer_intv = TIPC_DISC_INIT; 281 mod_timer(&d->timer, jiffies + d->timer_intv); 282 } 283 spin_unlock_bh(&d->lock); 284} 285 286/* tipc_disc_timeout - send a periodic link setup request 287 * Called whenever a link setup request timer associated with a bearer expires. 288 * - Keep doubling time between sent request until limit is reached; 289 * - Hold at fast polling rate if we don't have any associated nodes 290 * - Otherwise hold at slow polling rate 291 */ 292static void tipc_disc_timeout(struct timer_list *t) 293{ 294 struct tipc_discoverer *d = from_timer(d, t, timer); 295 struct tipc_net *tn = tipc_net(d->net); 296 struct tipc_media_addr maddr; 297 struct sk_buff *skb = NULL; 298 struct net *net = d->net; 299 u32 bearer_id; 300 301 spin_lock_bh(&d->lock); 302 303 /* Stop searching if only desired node has been found */ 304 if (tipc_node(d->domain) && d->num_nodes) { 305 d->timer_intv = TIPC_DISC_INACTIVE; 306 goto exit; 307 } 308 309 /* Did we just leave trial period ? */ 310 if (!time_before(jiffies, tn->addr_trial_end) && !tipc_own_addr(net)) { 311 mod_timer(&d->timer, jiffies + TIPC_DISC_INIT); 312 spin_unlock_bh(&d->lock); 313 schedule_work(&tn->work); 314 return; 315 } 316 317 /* Adjust timeout interval according to discovery phase */ 318 if (time_before(jiffies, tn->addr_trial_end)) { 319 d->timer_intv = TIPC_DISC_INIT; 320 } else { 321 d->timer_intv *= 2; 322 if (d->num_nodes && d->timer_intv > TIPC_DISC_SLOW) 323 d->timer_intv = TIPC_DISC_SLOW; 324 else if (!d->num_nodes && d->timer_intv > TIPC_DISC_FAST) 325 d->timer_intv = TIPC_DISC_FAST; 326 msg_set_type(buf_msg(d->skb), DSC_REQ_MSG); 327 msg_set_prevnode(buf_msg(d->skb), tn->trial_addr); 328 } 329 330 mod_timer(&d->timer, jiffies + d->timer_intv); 331 memcpy(&maddr, &d->dest, sizeof(maddr)); 332 skb = skb_clone(d->skb, GFP_ATOMIC); 333 bearer_id = d->bearer_id; 334exit: 335 spin_unlock_bh(&d->lock); 336 if (skb) 337 tipc_bearer_xmit_skb(net, bearer_id, skb, &maddr); 338} 339 340/** 341 * tipc_disc_create - create object to send periodic link setup requests 342 * @net: the applicable net namespace 343 * @b: ptr to bearer issuing requests 344 * @dest: destination address for request messages 345 * @skb: pointer to created frame 346 * 347 * Returns 0 if successful, otherwise -errno. 348 */ 349int tipc_disc_create(struct net *net, struct tipc_bearer *b, 350 struct tipc_media_addr *dest, struct sk_buff **skb) 351{ 352 struct tipc_net *tn = tipc_net(net); 353 struct tipc_discoverer *d; 354 355 d = kmalloc(sizeof(*d), GFP_ATOMIC); 356 if (!d) 357 return -ENOMEM; 358 d->skb = tipc_buf_acquire(MAX_H_SIZE + NODE_ID_LEN, GFP_ATOMIC); 359 if (!d->skb) { 360 kfree(d); 361 return -ENOMEM; 362 } 363 tipc_disc_init_msg(net, d->skb, DSC_REQ_MSG, b); 364 365 /* Do we need an address trial period first ? */ 366 if (!tipc_own_addr(net)) { 367 tn->addr_trial_end = jiffies + msecs_to_jiffies(1000); 368 msg_set_type(buf_msg(d->skb), DSC_TRIAL_MSG); 369 } 370 memcpy(&d->dest, dest, sizeof(*dest)); 371 d->net = net; 372 d->bearer_id = b->identity; 373 d->domain = b->domain; 374 d->num_nodes = 0; 375 d->timer_intv = TIPC_DISC_INIT; 376 spin_lock_init(&d->lock); 377 timer_setup(&d->timer, tipc_disc_timeout, 0); 378 mod_timer(&d->timer, jiffies + d->timer_intv); 379 b->disc = d; 380 *skb = skb_clone(d->skb, GFP_ATOMIC); 381 return 0; 382} 383 384/** 385 * tipc_disc_delete - destroy object sending periodic link setup requests 386 * @d: ptr to link duest structure 387 */ 388void tipc_disc_delete(struct tipc_discoverer *d) 389{ 390 del_timer_sync(&d->timer); 391 kfree_skb(d->skb); 392 kfree(d); 393} 394 395/** 396 * tipc_disc_reset - reset object to send periodic link setup requests 397 * @net: the applicable net namespace 398 * @b: ptr to bearer issuing requests 399 */ 400void tipc_disc_reset(struct net *net, struct tipc_bearer *b) 401{ 402 struct tipc_discoverer *d = b->disc; 403 struct tipc_media_addr maddr; 404 struct sk_buff *skb; 405 406 spin_lock_bh(&d->lock); 407 tipc_disc_init_msg(net, d->skb, DSC_REQ_MSG, b); 408 d->net = net; 409 d->bearer_id = b->identity; 410 d->domain = b->domain; 411 d->num_nodes = 0; 412 d->timer_intv = TIPC_DISC_INIT; 413 memcpy(&maddr, &d->dest, sizeof(maddr)); 414 mod_timer(&d->timer, jiffies + d->timer_intv); 415 skb = skb_clone(d->skb, GFP_ATOMIC); 416 spin_unlock_bh(&d->lock); 417 if (skb) 418 tipc_bearer_xmit_skb(net, b->identity, skb, &maddr); 419} 420