Commit | Line | Data |
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b97bf3fd PL |
1 | /* |
2 | * net/tipc/discover.c | |
c4307285 | 3 | * |
9da1c8b6 | 4 | * Copyright (c) 2003-2006, 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 |
b97bf3fd PL |
49 | * @bearer: bearer issuing requests |
50 | * @dest: destination address for request messages | |
66e019a6 | 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 { |
2d627b92 | 59 | struct tipc_bearer *bearer; |
b97bf3fd | 60 | struct tipc_media_addr dest; |
66e019a6 | 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 | * @dest_domain: network domain of node(s) which should respond to message |
73 | * @b_ptr: ptr to bearer issuing message | |
74 | */ | |
ae8509c4 | 75 | static struct sk_buff *tipc_disc_init_msg(u32 type, u32 dest_domain, |
2d627b92 | 76 | struct tipc_bearer *b_ptr) |
b97bf3fd | 77 | { |
d901a42b | 78 | struct sk_buff *buf = tipc_buf_acquire(INT_H_SIZE); |
b97bf3fd PL |
79 | struct tipc_msg *msg; |
80 | ||
81 | if (buf) { | |
82 | msg = buf_msg(buf); | |
d901a42b | 83 | tipc_msg_init(msg, LINK_CONFIG, type, INT_H_SIZE, dest_domain); |
40aecb1b | 84 | msg_set_non_seq(msg, 1); |
fc0eea69 | 85 | msg_set_node_sig(msg, tipc_random); |
b97bf3fd PL |
86 | msg_set_dest_domain(msg, dest_domain); |
87 | msg_set_bc_netid(msg, tipc_net_id); | |
3d749a6a | 88 | b_ptr->media->addr2msg(&b_ptr->addr, msg_media_addr(msg)); |
b97bf3fd PL |
89 | } |
90 | return buf; | |
91 | } | |
92 | ||
e91ed0bc AS |
93 | /** |
94 | * disc_dupl_alert - issue node address duplication alert | |
95 | * @b_ptr: pointer to bearer detecting duplication | |
96 | * @node_addr: duplicated node address | |
97 | * @media_addr: media address advertised by duplicated node | |
98 | */ | |
2d627b92 | 99 | static void disc_dupl_alert(struct tipc_bearer *b_ptr, u32 node_addr, |
e91ed0bc AS |
100 | struct tipc_media_addr *media_addr) |
101 | { | |
102 | char node_addr_str[16]; | |
103 | char media_addr_str[64]; | |
e91ed0bc | 104 | |
c68ca7b7 | 105 | tipc_addr_string_fill(node_addr_str, node_addr); |
dc1aed37 EH |
106 | tipc_media_addr_printf(media_addr_str, sizeof(media_addr_str), |
107 | media_addr); | |
2cf8aa19 EH |
108 | pr_warn("Duplicate %s using %s seen on <%s>\n", node_addr_str, |
109 | media_addr_str, b_ptr->name); | |
e91ed0bc AS |
110 | } |
111 | ||
b97bf3fd | 112 | /** |
4323add6 | 113 | * tipc_disc_recv_msg - handle incoming link setup message (request or response) |
b97bf3fd | 114 | * @buf: buffer containing message |
1265a021 | 115 | * @b_ptr: bearer that message arrived on |
b97bf3fd | 116 | */ |
2d627b92 | 117 | void tipc_disc_recv_msg(struct sk_buff *buf, struct tipc_bearer *b_ptr) |
b97bf3fd | 118 | { |
a728750e | 119 | struct tipc_node *n_ptr; |
a18c4bc3 | 120 | struct tipc_link *link; |
97878a40 | 121 | struct tipc_media_addr media_addr; |
a728750e | 122 | struct sk_buff *rbuf; |
b97bf3fd PL |
123 | struct tipc_msg *msg = buf_msg(buf); |
124 | u32 dest = msg_dest_domain(msg); | |
125 | u32 orig = msg_prevnode(msg); | |
126 | u32 net_id = msg_bc_netid(msg); | |
127 | u32 type = msg_type(msg); | |
fc0eea69 | 128 | u32 signature = msg_node_sig(msg); |
97878a40 | 129 | int addr_mismatch; |
a728750e | 130 | int link_fully_up; |
b97bf3fd | 131 | |
d6d4577a | 132 | media_addr.broadcast = 1; |
8aeb89f2 | 133 | b_ptr->media->msg2addr(b_ptr, &media_addr, msg_media_addr(msg)); |
5f6d9123 | 134 | kfree_skb(buf); |
b97bf3fd | 135 | |
97878a40 | 136 | /* Ensure message from node is valid and communication is permitted */ |
b97bf3fd PL |
137 | if (net_id != tipc_net_id) |
138 | return; | |
d6d4577a AS |
139 | if (media_addr.broadcast) |
140 | return; | |
4323add6 | 141 | if (!tipc_addr_domain_valid(dest)) |
b97bf3fd | 142 | return; |
4323add6 | 143 | if (!tipc_addr_node_valid(orig)) |
b97bf3fd | 144 | return; |
e91ed0bc | 145 | if (orig == tipc_own_addr) { |
2d627b92 | 146 | if (memcmp(&media_addr, &b_ptr->addr, sizeof(media_addr))) |
e91ed0bc | 147 | disc_dupl_alert(b_ptr, tipc_own_addr, &media_addr); |
b97bf3fd | 148 | return; |
e91ed0bc | 149 | } |
c68ca7b7 | 150 | if (!tipc_in_scope(dest, tipc_own_addr)) |
b97bf3fd | 151 | return; |
66e019a6 | 152 | if (!tipc_in_scope(b_ptr->link_req->domain, orig)) |
a728750e | 153 | return; |
5a68d5ee | 154 | |
a728750e AS |
155 | /* Locate structure corresponding to requesting node */ |
156 | n_ptr = tipc_node_find(orig); | |
157 | if (!n_ptr) { | |
158 | n_ptr = tipc_node_create(orig); | |
159 | if (!n_ptr) | |
5a68d5ee | 160 | return; |
a728750e AS |
161 | } |
162 | tipc_node_lock(n_ptr); | |
163 | ||
97878a40 | 164 | /* Prepare to validate requesting node's signature and media address */ |
a728750e | 165 | link = n_ptr->links[b_ptr->identity]; |
97878a40 AS |
166 | addr_mismatch = (link != NULL) && |
167 | memcmp(&link->media_addr, &media_addr, sizeof(media_addr)); | |
a728750e | 168 | |
97878a40 AS |
169 | /* |
170 | * Ensure discovery message's signature is correct | |
171 | * | |
172 | * If signature is incorrect and there is no working link to the node, | |
173 | * accept the new signature but invalidate all existing links to the | |
174 | * node so they won't re-activate without a new discovery message. | |
175 | * | |
176 | * If signature is incorrect and the requested link to the node is | |
177 | * working, accept the new signature. (This is an instance of delayed | |
178 | * rediscovery, where a link endpoint was able to re-establish contact | |
179 | * with its peer endpoint on a node that rebooted before receiving a | |
180 | * discovery message from that node.) | |
181 | * | |
182 | * If signature is incorrect and there is a working link to the node | |
183 | * that is not the requested link, reject the request (must be from | |
184 | * a duplicate node). | |
185 | */ | |
186 | if (signature != n_ptr->signature) { | |
187 | if (n_ptr->working_links == 0) { | |
188 | struct tipc_link *curr_link; | |
189 | int i; | |
190 | ||
191 | for (i = 0; i < MAX_BEARERS; i++) { | |
192 | curr_link = n_ptr->links[i]; | |
193 | if (curr_link) { | |
194 | memset(&curr_link->media_addr, 0, | |
195 | sizeof(media_addr)); | |
196 | tipc_link_reset(curr_link); | |
197 | } | |
198 | } | |
199 | addr_mismatch = (link != NULL); | |
200 | } else if (tipc_link_is_up(link) && !addr_mismatch) { | |
201 | /* delayed rediscovery */ | |
202 | } else { | |
203 | disc_dupl_alert(b_ptr, orig, &media_addr); | |
a728750e AS |
204 | tipc_node_unlock(n_ptr); |
205 | return; | |
b97bf3fd | 206 | } |
97878a40 | 207 | n_ptr->signature = signature; |
a728750e AS |
208 | } |
209 | ||
210 | /* | |
211 | * Ensure requesting node's media address is correct | |
212 | * | |
213 | * If media address doesn't match and the link is working, reject the | |
214 | * request (must be from a duplicate node). | |
215 | * | |
216 | * If media address doesn't match and the link is not working, accept | |
217 | * the new media address and reset the link to ensure it starts up | |
218 | * cleanly. | |
219 | */ | |
97878a40 AS |
220 | if (addr_mismatch) { |
221 | if (tipc_link_is_up(link)) { | |
a728750e AS |
222 | disc_dupl_alert(b_ptr, orig, &media_addr); |
223 | tipc_node_unlock(n_ptr); | |
b97bf3fd | 224 | return; |
97878a40 AS |
225 | } else { |
226 | memcpy(&link->media_addr, &media_addr, | |
227 | sizeof(media_addr)); | |
228 | tipc_link_reset(link); | |
229 | } | |
230 | } | |
231 | ||
232 | /* Create a link endpoint for this bearer, if necessary */ | |
233 | if (!link) { | |
234 | link = tipc_link_create(n_ptr, b_ptr, &media_addr); | |
235 | if (!link) { | |
236 | tipc_node_unlock(n_ptr); | |
237 | return; | |
b97bf3fd | 238 | } |
a728750e AS |
239 | } |
240 | ||
241 | /* Accept discovery message & send response, if necessary */ | |
242 | link_fully_up = link_working_working(link); | |
fa2bae2d | 243 | |
512137ee | 244 | if ((type == DSC_REQ_MSG) && !link_fully_up) { |
fa2bae2d AS |
245 | rbuf = tipc_disc_init_msg(DSC_RESP_MSG, orig, b_ptr); |
246 | if (rbuf) { | |
3c294cb3 | 247 | tipc_bearer_send(b_ptr, rbuf, &media_addr); |
5f6d9123 | 248 | kfree_skb(rbuf); |
fa2bae2d | 249 | } |
b97bf3fd | 250 | } |
fa2bae2d AS |
251 | |
252 | tipc_node_unlock(n_ptr); | |
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 */ |
972a77fb AS |
309 | if (tipc_node(req->domain) && req->num_nodes) { |
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 | */ | |
512137ee EH |
321 | tipc_bearer_send(req->bearer, req->buf, &req->dest); |
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 | */ |
ae8509c4 PG |
345 | int tipc_disc_create(struct tipc_bearer *b_ptr, struct tipc_media_addr *dest, |
346 | u32 dest_domain) | |
b97bf3fd | 347 | { |
a18c4bc3 | 348 | struct tipc_link_req *req; |
b97bf3fd | 349 | |
9df3f3d2 | 350 | req = kmalloc(sizeof(*req), GFP_ATOMIC); |
b97bf3fd | 351 | if (!req) |
3a777ff8 | 352 | return -ENOMEM; |
b97bf3fd | 353 | |
2e07dda1 | 354 | req->buf = tipc_disc_init_msg(DSC_REQ_MSG, dest_domain, b_ptr); |
b97bf3fd PL |
355 | if (!req->buf) { |
356 | kfree(req); | |
3a777ff8 | 357 | return -ENOMSG; |
b97bf3fd PL |
358 | } |
359 | ||
360 | memcpy(&req->dest, dest, sizeof(*dest)); | |
361 | req->bearer = b_ptr; | |
66e019a6 | 362 | req->domain = dest_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; |
512137ee | 369 | tipc_bearer_send(req->bearer, 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 | } |