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