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b97bf3fd PL |
1 | /* |
2 | * net/tipc/discover.c | |
c4307285 | 3 | * |
b45db71b | 4 | * Copyright (c) 2003-2006, 2014-2015, Ericsson AB |
2d627b92 | 5 | * Copyright (c) 2005-2006, 2010-2011, Wind River Systems |
b97bf3fd PL |
6 | * All rights reserved. |
7 | * | |
9ea1fd3c | 8 | * Redistribution and use in source and binary forms, with or without |
b97bf3fd PL |
9 | * modification, are permitted provided that the following conditions are met: |
10 | * | |
9ea1fd3c PL |
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. | |
b97bf3fd | 19 | * |
9ea1fd3c PL |
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 | |
b97bf3fd PL |
34 | * POSSIBILITY OF SUCH DAMAGE. |
35 | */ | |
36 | ||
37 | #include "core.h" | |
b97bf3fd | 38 | #include "link.h" |
b97bf3fd | 39 | #include "discover.h" |
b97bf3fd | 40 | |
2f55c437 YX |
41 | /* min delay during bearer start up */ |
42 | #define TIPC_LINK_REQ_INIT msecs_to_jiffies(125) | |
43 | /* max delay if bearer has no links */ | |
44 | #define TIPC_LINK_REQ_FAST msecs_to_jiffies(1000) | |
45 | /* max delay if bearer has links */ | |
46 | #define TIPC_LINK_REQ_SLOW msecs_to_jiffies(60000) | |
47 | /* indicates no timer in use */ | |
48 | #define TIPC_LINK_REQ_INACTIVE 0xffffffff | |
b97bf3fd | 49 | |
b97bf3fd | 50 | /** |
a18c4bc3 | 51 | * struct tipc_link_req - information about an ongoing link setup request |
7a2f7d18 | 52 | * @bearer_id: identity of bearer issuing requests |
7f9f95d9 | 53 | * @net: network namespace instance |
b97bf3fd | 54 | * @dest: destination address for request messages |
7a2f7d18 | 55 | * @domain: network domain to which links can be established |
1209966c | 56 | * @num_nodes: number of nodes currently discovered (i.e. with an active link) |
f9a2c80b | 57 | * @lock: spinlock for controlling access to requests |
b97bf3fd PL |
58 | * @buf: request message to be (repeatedly) sent |
59 | * @timer: timer governing period between requests | |
60 | * @timer_intv: current interval between requests (in ms) | |
61 | */ | |
a18c4bc3 | 62 | struct tipc_link_req { |
7a2f7d18 | 63 | u32 bearer_id; |
b97bf3fd | 64 | struct tipc_media_addr dest; |
7f9f95d9 | 65 | struct net *net; |
7a2f7d18 | 66 | u32 domain; |
1209966c | 67 | int num_nodes; |
f9a2c80b | 68 | spinlock_t lock; |
b97bf3fd PL |
69 | struct sk_buff *buf; |
70 | struct timer_list timer; | |
2f55c437 | 71 | unsigned long timer_intv; |
b97bf3fd PL |
72 | }; |
73 | ||
c4307285 | 74 | /** |
4323add6 | 75 | * tipc_disc_init_msg - initialize a link setup message |
c93d3baa | 76 | * @net: the applicable net namespace |
b97bf3fd | 77 | * @type: message type (request or response) |
b97bf3fd PL |
78 | * @b_ptr: ptr to bearer issuing message |
79 | */ | |
c93d3baa | 80 | static void tipc_disc_init_msg(struct net *net, struct sk_buff *buf, u32 type, |
a8b9b96e | 81 | struct tipc_bearer *b_ptr) |
b97bf3fd | 82 | { |
c93d3baa | 83 | struct tipc_net *tn = net_generic(net, tipc_net_id); |
b97bf3fd | 84 | struct tipc_msg *msg; |
16470111 | 85 | u32 dest_domain = b_ptr->domain; |
b97bf3fd | 86 | |
a8b9b96e | 87 | msg = buf_msg(buf); |
c5898636 | 88 | tipc_msg_init(tn->own_addr, msg, LINK_CONFIG, type, |
948fa2d1 | 89 | MAX_H_SIZE, dest_domain); |
a8b9b96e | 90 | msg_set_non_seq(msg, 1); |
bafa29e3 | 91 | msg_set_node_sig(msg, tn->random); |
7764d6e8 | 92 | msg_set_node_capabilities(msg, 0); |
a8b9b96e | 93 | msg_set_dest_domain(msg, dest_domain); |
c93d3baa | 94 | msg_set_bc_netid(msg, tn->net_id); |
38504c28 | 95 | b_ptr->media->addr2msg(msg_media_addr(msg), &b_ptr->addr); |
b97bf3fd PL |
96 | } |
97 | ||
e91ed0bc AS |
98 | /** |
99 | * disc_dupl_alert - issue node address duplication alert | |
100 | * @b_ptr: pointer to bearer detecting duplication | |
101 | * @node_addr: duplicated node address | |
102 | * @media_addr: media address advertised by duplicated node | |
103 | */ | |
2d627b92 | 104 | static void disc_dupl_alert(struct tipc_bearer *b_ptr, u32 node_addr, |
e91ed0bc AS |
105 | struct tipc_media_addr *media_addr) |
106 | { | |
107 | char node_addr_str[16]; | |
108 | char media_addr_str[64]; | |
e91ed0bc | 109 | |
c68ca7b7 | 110 | tipc_addr_string_fill(node_addr_str, node_addr); |
dc1aed37 EH |
111 | tipc_media_addr_printf(media_addr_str, sizeof(media_addr_str), |
112 | media_addr); | |
2cf8aa19 EH |
113 | pr_warn("Duplicate %s using %s seen on <%s>\n", node_addr_str, |
114 | media_addr_str, b_ptr->name); | |
e91ed0bc AS |
115 | } |
116 | ||
b97bf3fd | 117 | /** |
c82910e2 | 118 | * tipc_disc_rcv - handle incoming discovery message (request or response) |
c93d3baa | 119 | * @net: the applicable net namespace |
b97bf3fd | 120 | * @buf: buffer containing message |
c82910e2 | 121 | * @bearer: bearer that message arrived on |
b97bf3fd | 122 | */ |
c93d3baa YX |
123 | void tipc_disc_rcv(struct net *net, struct sk_buff *buf, |
124 | struct tipc_bearer *bearer) | |
b97bf3fd | 125 | { |
c93d3baa | 126 | struct tipc_net *tn = net_generic(net, tipc_net_id); |
c82910e2 | 127 | struct tipc_node *node; |
a18c4bc3 | 128 | struct tipc_link *link; |
c82910e2 | 129 | struct tipc_media_addr maddr; |
a728750e | 130 | struct sk_buff *rbuf; |
b97bf3fd | 131 | struct tipc_msg *msg = buf_msg(buf); |
c82910e2 JPM |
132 | u32 ddom = msg_dest_domain(msg); |
133 | u32 onode = msg_prevnode(msg); | |
b97bf3fd | 134 | u32 net_id = msg_bc_netid(msg); |
c82910e2 | 135 | u32 mtyp = msg_type(msg); |
fc0eea69 | 136 | u32 signature = msg_node_sig(msg); |
7764d6e8 | 137 | u16 caps = msg_node_capabilities(msg); |
c82910e2 JPM |
138 | bool addr_match = false; |
139 | bool sign_match = false; | |
140 | bool link_up = false; | |
141 | bool accept_addr = false; | |
142 | bool accept_sign = false; | |
143 | bool respond = false; | |
b97bf3fd | 144 | |
c82910e2 | 145 | bearer->media->msg2addr(bearer, &maddr, msg_media_addr(msg)); |
5f6d9123 | 146 | kfree_skb(buf); |
b97bf3fd | 147 | |
97878a40 | 148 | /* Ensure message from node is valid and communication is permitted */ |
c93d3baa | 149 | if (net_id != tn->net_id) |
b97bf3fd | 150 | return; |
c82910e2 | 151 | if (maddr.broadcast) |
d6d4577a | 152 | return; |
c82910e2 | 153 | if (!tipc_addr_domain_valid(ddom)) |
b97bf3fd | 154 | return; |
c82910e2 | 155 | if (!tipc_addr_node_valid(onode)) |
b97bf3fd | 156 | return; |
c82910e2 | 157 | |
34747539 | 158 | if (in_own_node(net, onode)) { |
c82910e2 | 159 | if (memcmp(&maddr, &bearer->addr, sizeof(maddr))) |
34747539 | 160 | disc_dupl_alert(bearer, tn->own_addr, &maddr); |
b97bf3fd | 161 | return; |
e91ed0bc | 162 | } |
34747539 | 163 | if (!tipc_in_scope(ddom, tn->own_addr)) |
b97bf3fd | 164 | return; |
c82910e2 | 165 | if (!tipc_in_scope(bearer->domain, onode)) |
a728750e | 166 | return; |
5a68d5ee | 167 | |
b45db71b | 168 | node = tipc_node_create(net, onode); |
c82910e2 JPM |
169 | if (!node) |
170 | return; | |
c82910e2 | 171 | tipc_node_lock(node); |
7764d6e8 | 172 | node->capabilities = caps; |
9d13ec65 | 173 | link = node->links[bearer->identity].link; |
a728750e | 174 | |
97878a40 | 175 | /* Prepare to validate requesting node's signature and media address */ |
c82910e2 JPM |
176 | sign_match = (signature == node->signature); |
177 | addr_match = link && !memcmp(&link->media_addr, &maddr, sizeof(maddr)); | |
178 | link_up = link && tipc_link_is_up(link); | |
a728750e | 179 | |
97878a40 | 180 | |
c82910e2 | 181 | /* These three flags give us eight permutations: */ |
a728750e | 182 | |
c82910e2 JPM |
183 | if (sign_match && addr_match && link_up) { |
184 | /* All is fine. Do nothing. */ | |
185 | } else if (sign_match && addr_match && !link_up) { | |
186 | /* Respond. The link will come up in due time */ | |
187 | respond = true; | |
188 | } else if (sign_match && !addr_match && link_up) { | |
189 | /* Peer has changed i/f address without rebooting. | |
190 | * If so, the link will reset soon, and the next | |
191 | * discovery will be accepted. So we can ignore it. | |
192 | * It may also be an cloned or malicious peer having | |
193 | * chosen the same node address and signature as an | |
194 | * existing one. | |
195 | * Ignore requests until the link goes down, if ever. | |
196 | */ | |
197 | disc_dupl_alert(bearer, onode, &maddr); | |
198 | } else if (sign_match && !addr_match && !link_up) { | |
199 | /* Peer link has changed i/f address without rebooting. | |
200 | * It may also be a cloned or malicious peer; we can't | |
201 | * distinguish between the two. | |
202 | * The signature is correct, so we must accept. | |
203 | */ | |
204 | accept_addr = true; | |
205 | respond = true; | |
206 | } else if (!sign_match && addr_match && link_up) { | |
207 | /* Peer node rebooted. Two possibilities: | |
208 | * - Delayed re-discovery; this link endpoint has already | |
209 | * reset and re-established contact with the peer, before | |
210 | * receiving a discovery message from that node. | |
211 | * (The peer happened to receive one from this node first). | |
212 | * - The peer came back so fast that our side has not | |
213 | * discovered it yet. Probing from this side will soon | |
214 | * reset the link, since there can be no working link | |
215 | * endpoint at the peer end, and the link will re-establish. | |
216 | * Accept the signature, since it comes from a known peer. | |
217 | */ | |
218 | accept_sign = true; | |
219 | } else if (!sign_match && addr_match && !link_up) { | |
220 | /* The peer node has rebooted. | |
221 | * Accept signature, since it is a known peer. | |
222 | */ | |
223 | accept_sign = true; | |
224 | respond = true; | |
225 | } else if (!sign_match && !addr_match && link_up) { | |
226 | /* Peer rebooted with new address, or a new/duplicate peer. | |
227 | * Ignore until the link goes down, if ever. | |
228 | */ | |
229 | disc_dupl_alert(bearer, onode, &maddr); | |
230 | } else if (!sign_match && !addr_match && !link_up) { | |
231 | /* Peer rebooted with new address, or it is a new peer. | |
232 | * Accept signature and address. | |
233 | */ | |
234 | accept_sign = true; | |
235 | accept_addr = true; | |
236 | respond = true; | |
97878a40 AS |
237 | } |
238 | ||
c82910e2 JPM |
239 | if (accept_sign) |
240 | node->signature = signature; | |
241 | ||
242 | if (accept_addr) { | |
243 | if (!link) | |
244 | link = tipc_link_create(node, bearer, &maddr); | |
245 | if (link) { | |
246 | memcpy(&link->media_addr, &maddr, sizeof(maddr)); | |
247 | tipc_link_reset(link); | |
248 | } else { | |
249 | respond = false; | |
b97bf3fd | 250 | } |
a728750e AS |
251 | } |
252 | ||
c82910e2 JPM |
253 | /* Send response, if necessary */ |
254 | if (respond && (mtyp == DSC_REQ_MSG)) { | |
948fa2d1 | 255 | rbuf = tipc_buf_acquire(MAX_H_SIZE); |
fa2bae2d | 256 | if (rbuf) { |
c93d3baa | 257 | tipc_disc_init_msg(net, rbuf, DSC_RESP_MSG, bearer); |
7f9f95d9 | 258 | tipc_bearer_send(net, bearer->identity, rbuf, &maddr); |
5f6d9123 | 259 | kfree_skb(rbuf); |
fa2bae2d | 260 | } |
b97bf3fd | 261 | } |
c82910e2 | 262 | tipc_node_unlock(node); |
8a0f6ebe | 263 | tipc_node_put(node); |
b97bf3fd PL |
264 | } |
265 | ||
b97bf3fd | 266 | /** |
1209966c | 267 | * disc_update - update frequency of periodic link setup requests |
b97bf3fd | 268 | * @req: ptr to link request structure |
972a77fb AS |
269 | * |
270 | * Reinitiates discovery process if discovery object has no associated nodes | |
271 | * and is either not currently searching or is searching at a slow rate | |
b97bf3fd | 272 | */ |
a18c4bc3 | 273 | static void disc_update(struct tipc_link_req *req) |
b97bf3fd | 274 | { |
972a77fb AS |
275 | if (!req->num_nodes) { |
276 | if ((req->timer_intv == TIPC_LINK_REQ_INACTIVE) || | |
277 | (req->timer_intv > TIPC_LINK_REQ_FAST)) { | |
278 | req->timer_intv = TIPC_LINK_REQ_INIT; | |
2f55c437 | 279 | mod_timer(&req->timer, jiffies + req->timer_intv); |
b97bf3fd | 280 | } |
b97bf3fd | 281 | } |
c4307285 | 282 | } |
b97bf3fd | 283 | |
1209966c AS |
284 | /** |
285 | * tipc_disc_add_dest - increment set of discovered nodes | |
286 | * @req: ptr to link request structure | |
287 | */ | |
a18c4bc3 | 288 | void tipc_disc_add_dest(struct tipc_link_req *req) |
1209966c | 289 | { |
f9a2c80b | 290 | spin_lock_bh(&req->lock); |
1209966c | 291 | req->num_nodes++; |
f9a2c80b | 292 | spin_unlock_bh(&req->lock); |
1209966c AS |
293 | } |
294 | ||
295 | /** | |
296 | * tipc_disc_remove_dest - decrement set of discovered nodes | |
297 | * @req: ptr to link request structure | |
298 | */ | |
a18c4bc3 | 299 | void tipc_disc_remove_dest(struct tipc_link_req *req) |
1209966c | 300 | { |
f9a2c80b | 301 | spin_lock_bh(&req->lock); |
1209966c AS |
302 | req->num_nodes--; |
303 | disc_update(req); | |
f9a2c80b | 304 | spin_unlock_bh(&req->lock); |
1209966c AS |
305 | } |
306 | ||
b97bf3fd PL |
307 | /** |
308 | * disc_timeout - send a periodic link setup request | |
2f55c437 | 309 | * @data: ptr to link request structure |
c4307285 | 310 | * |
b97bf3fd PL |
311 | * Called whenever a link setup request timer associated with a bearer expires. |
312 | */ | |
2f55c437 | 313 | static void disc_timeout(unsigned long data) |
b97bf3fd | 314 | { |
2f55c437 | 315 | struct tipc_link_req *req = (struct tipc_link_req *)data; |
972a77fb AS |
316 | int max_delay; |
317 | ||
f9a2c80b | 318 | spin_lock_bh(&req->lock); |
b97bf3fd | 319 | |
972a77fb | 320 | /* Stop searching if only desired node has been found */ |
7a2f7d18 | 321 | if (tipc_node(req->domain) && req->num_nodes) { |
972a77fb AS |
322 | req->timer_intv = TIPC_LINK_REQ_INACTIVE; |
323 | goto exit; | |
b97bf3fd | 324 | } |
b97bf3fd | 325 | |
972a77fb AS |
326 | /* |
327 | * Send discovery message, then update discovery timer | |
328 | * | |
329 | * Keep doubling time between requests until limit is reached; | |
330 | * hold at fast polling rate if don't have any associated nodes, | |
331 | * otherwise hold at slow polling rate | |
332 | */ | |
7f9f95d9 | 333 | tipc_bearer_send(req->net, req->bearer_id, req->buf, &req->dest); |
512137ee | 334 | |
972a77fb AS |
335 | |
336 | req->timer_intv *= 2; | |
337 | if (req->num_nodes) | |
338 | max_delay = TIPC_LINK_REQ_SLOW; | |
339 | else | |
340 | max_delay = TIPC_LINK_REQ_FAST; | |
341 | if (req->timer_intv > max_delay) | |
342 | req->timer_intv = max_delay; | |
343 | ||
2f55c437 | 344 | mod_timer(&req->timer, jiffies + req->timer_intv); |
972a77fb | 345 | exit: |
f9a2c80b | 346 | spin_unlock_bh(&req->lock); |
b97bf3fd PL |
347 | } |
348 | ||
349 | /** | |
3a777ff8 | 350 | * tipc_disc_create - create object to send periodic link setup requests |
c93d3baa | 351 | * @net: the applicable net namespace |
b97bf3fd PL |
352 | * @b_ptr: ptr to bearer issuing requests |
353 | * @dest: destination address for request messages | |
66e019a6 | 354 | * @dest_domain: network domain to which links can be established |
c4307285 | 355 | * |
3a777ff8 | 356 | * Returns 0 if successful, otherwise -errno. |
b97bf3fd | 357 | */ |
c93d3baa YX |
358 | int tipc_disc_create(struct net *net, struct tipc_bearer *b_ptr, |
359 | struct tipc_media_addr *dest) | |
b97bf3fd | 360 | { |
a18c4bc3 | 361 | struct tipc_link_req *req; |
b97bf3fd | 362 | |
9df3f3d2 | 363 | req = kmalloc(sizeof(*req), GFP_ATOMIC); |
b97bf3fd | 364 | if (!req) |
3a777ff8 | 365 | return -ENOMEM; |
948fa2d1 | 366 | req->buf = tipc_buf_acquire(MAX_H_SIZE); |
22e7987a YX |
367 | if (!req->buf) { |
368 | kfree(req); | |
a8b9b96e | 369 | return -ENOMEM; |
22e7987a | 370 | } |
b97bf3fd | 371 | |
c93d3baa | 372 | tipc_disc_init_msg(net, req->buf, DSC_REQ_MSG, b_ptr); |
b97bf3fd | 373 | memcpy(&req->dest, dest, sizeof(*dest)); |
7f9f95d9 | 374 | req->net = net; |
7a2f7d18 YX |
375 | req->bearer_id = b_ptr->identity; |
376 | req->domain = b_ptr->domain; | |
1209966c | 377 | req->num_nodes = 0; |
b97bf3fd | 378 | req->timer_intv = TIPC_LINK_REQ_INIT; |
f9a2c80b | 379 | spin_lock_init(&req->lock); |
2f55c437 YX |
380 | setup_timer(&req->timer, disc_timeout, (unsigned long)req); |
381 | mod_timer(&req->timer, jiffies + req->timer_intv); | |
3a777ff8 | 382 | b_ptr->link_req = req; |
7f9f95d9 | 383 | tipc_bearer_send(net, req->bearer_id, req->buf, &req->dest); |
3a777ff8 AS |
384 | return 0; |
385 | } | |
386 | ||
387 | /** | |
388 | * tipc_disc_delete - destroy object sending periodic link setup requests | |
389 | * @req: ptr to link request structure | |
390 | */ | |
a18c4bc3 | 391 | void tipc_disc_delete(struct tipc_link_req *req) |
3a777ff8 | 392 | { |
2f55c437 | 393 | del_timer_sync(&req->timer); |
5f6d9123 | 394 | kfree_skb(req->buf); |
3a777ff8 | 395 | kfree(req); |
c4307285 | 396 | } |
a8b9b96e YX |
397 | |
398 | /** | |
399 | * tipc_disc_reset - reset object to send periodic link setup requests | |
c93d3baa | 400 | * @net: the applicable net namespace |
a8b9b96e YX |
401 | * @b_ptr: ptr to bearer issuing requests |
402 | * @dest_domain: network domain to which links can be established | |
403 | */ | |
c93d3baa | 404 | void tipc_disc_reset(struct net *net, struct tipc_bearer *b_ptr) |
a8b9b96e YX |
405 | { |
406 | struct tipc_link_req *req = b_ptr->link_req; | |
407 | ||
408 | spin_lock_bh(&req->lock); | |
c93d3baa | 409 | tipc_disc_init_msg(net, req->buf, DSC_REQ_MSG, b_ptr); |
7f9f95d9 | 410 | req->net = net; |
a8b9b96e YX |
411 | req->bearer_id = b_ptr->identity; |
412 | req->domain = b_ptr->domain; | |
413 | req->num_nodes = 0; | |
414 | req->timer_intv = TIPC_LINK_REQ_INIT; | |
2f55c437 | 415 | mod_timer(&req->timer, jiffies + req->timer_intv); |
7f9f95d9 | 416 | tipc_bearer_send(net, req->bearer_id, req->buf, &req->dest); |
a8b9b96e YX |
417 | spin_unlock_bh(&req->lock); |
418 | } |