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 | |
1209966c | 51 | * @num_nodes: number of nodes currently discovered (i.e. with an active link) |
f9a2c80b | 52 | * @lock: spinlock for controlling access to requests |
b97bf3fd PL |
53 | * @buf: request message to be (repeatedly) sent |
54 | * @timer: timer governing period between requests | |
55 | * @timer_intv: current interval between requests (in ms) | |
56 | */ | |
a18c4bc3 | 57 | struct tipc_link_req { |
2d627b92 | 58 | struct tipc_bearer *bearer; |
b97bf3fd | 59 | struct tipc_media_addr dest; |
1209966c | 60 | int num_nodes; |
f9a2c80b | 61 | spinlock_t lock; |
b97bf3fd PL |
62 | struct sk_buff *buf; |
63 | struct timer_list timer; | |
64 | unsigned int timer_intv; | |
65 | }; | |
66 | ||
c4307285 | 67 | /** |
4323add6 | 68 | * tipc_disc_init_msg - initialize a link setup message |
b97bf3fd | 69 | * @type: message type (request or response) |
b97bf3fd PL |
70 | * @b_ptr: ptr to bearer issuing message |
71 | */ | |
16470111 | 72 | static struct sk_buff *tipc_disc_init_msg(u32 type, struct tipc_bearer *b_ptr) |
b97bf3fd | 73 | { |
d901a42b | 74 | struct sk_buff *buf = tipc_buf_acquire(INT_H_SIZE); |
b97bf3fd | 75 | struct tipc_msg *msg; |
16470111 | 76 | u32 dest_domain = b_ptr->domain; |
b97bf3fd PL |
77 | |
78 | if (buf) { | |
79 | msg = buf_msg(buf); | |
d901a42b | 80 | tipc_msg_init(msg, LINK_CONFIG, type, INT_H_SIZE, dest_domain); |
40aecb1b | 81 | msg_set_non_seq(msg, 1); |
fc0eea69 | 82 | msg_set_node_sig(msg, tipc_random); |
b97bf3fd PL |
83 | msg_set_dest_domain(msg, dest_domain); |
84 | msg_set_bc_netid(msg, tipc_net_id); | |
3d749a6a | 85 | b_ptr->media->addr2msg(&b_ptr->addr, msg_media_addr(msg)); |
b97bf3fd PL |
86 | } |
87 | return buf; | |
88 | } | |
89 | ||
e91ed0bc AS |
90 | /** |
91 | * disc_dupl_alert - issue node address duplication alert | |
92 | * @b_ptr: pointer to bearer detecting duplication | |
93 | * @node_addr: duplicated node address | |
94 | * @media_addr: media address advertised by duplicated node | |
95 | */ | |
2d627b92 | 96 | static void disc_dupl_alert(struct tipc_bearer *b_ptr, u32 node_addr, |
e91ed0bc AS |
97 | struct tipc_media_addr *media_addr) |
98 | { | |
99 | char node_addr_str[16]; | |
100 | char media_addr_str[64]; | |
e91ed0bc | 101 | |
c68ca7b7 | 102 | tipc_addr_string_fill(node_addr_str, node_addr); |
dc1aed37 EH |
103 | tipc_media_addr_printf(media_addr_str, sizeof(media_addr_str), |
104 | media_addr); | |
2cf8aa19 EH |
105 | pr_warn("Duplicate %s using %s seen on <%s>\n", node_addr_str, |
106 | media_addr_str, b_ptr->name); | |
e91ed0bc AS |
107 | } |
108 | ||
b97bf3fd | 109 | /** |
247f0f3c | 110 | * tipc_disc_rcv - handle incoming link setup message (request or response) |
b97bf3fd | 111 | * @buf: buffer containing message |
1265a021 | 112 | * @b_ptr: bearer that message arrived on |
b97bf3fd | 113 | */ |
247f0f3c | 114 | void tipc_disc_rcv(struct sk_buff *buf, struct tipc_bearer *b_ptr) |
b97bf3fd | 115 | { |
a728750e | 116 | struct tipc_node *n_ptr; |
a18c4bc3 | 117 | struct tipc_link *link; |
97878a40 | 118 | struct tipc_media_addr media_addr; |
a728750e | 119 | struct sk_buff *rbuf; |
b97bf3fd PL |
120 | struct tipc_msg *msg = buf_msg(buf); |
121 | u32 dest = msg_dest_domain(msg); | |
122 | u32 orig = msg_prevnode(msg); | |
123 | u32 net_id = msg_bc_netid(msg); | |
124 | u32 type = msg_type(msg); | |
fc0eea69 | 125 | u32 signature = msg_node_sig(msg); |
97878a40 | 126 | int addr_mismatch; |
a728750e | 127 | int link_fully_up; |
b97bf3fd | 128 | |
d6d4577a | 129 | media_addr.broadcast = 1; |
8aeb89f2 | 130 | b_ptr->media->msg2addr(b_ptr, &media_addr, msg_media_addr(msg)); |
5f6d9123 | 131 | kfree_skb(buf); |
b97bf3fd | 132 | |
97878a40 | 133 | /* Ensure message from node is valid and communication is permitted */ |
b97bf3fd PL |
134 | if (net_id != tipc_net_id) |
135 | return; | |
d6d4577a AS |
136 | if (media_addr.broadcast) |
137 | return; | |
4323add6 | 138 | if (!tipc_addr_domain_valid(dest)) |
b97bf3fd | 139 | return; |
4323add6 | 140 | if (!tipc_addr_node_valid(orig)) |
b97bf3fd | 141 | return; |
e91ed0bc | 142 | if (orig == tipc_own_addr) { |
2d627b92 | 143 | if (memcmp(&media_addr, &b_ptr->addr, sizeof(media_addr))) |
e91ed0bc | 144 | disc_dupl_alert(b_ptr, tipc_own_addr, &media_addr); |
b97bf3fd | 145 | return; |
e91ed0bc | 146 | } |
c68ca7b7 | 147 | if (!tipc_in_scope(dest, tipc_own_addr)) |
b97bf3fd | 148 | return; |
16470111 | 149 | if (!tipc_in_scope(b_ptr->domain, orig)) |
a728750e | 150 | return; |
5a68d5ee | 151 | |
a728750e AS |
152 | /* Locate structure corresponding to requesting node */ |
153 | n_ptr = tipc_node_find(orig); | |
154 | if (!n_ptr) { | |
155 | n_ptr = tipc_node_create(orig); | |
156 | if (!n_ptr) | |
5a68d5ee | 157 | return; |
a728750e AS |
158 | } |
159 | tipc_node_lock(n_ptr); | |
160 | ||
97878a40 | 161 | /* Prepare to validate requesting node's signature and media address */ |
a728750e | 162 | link = n_ptr->links[b_ptr->identity]; |
97878a40 AS |
163 | addr_mismatch = (link != NULL) && |
164 | memcmp(&link->media_addr, &media_addr, sizeof(media_addr)); | |
a728750e | 165 | |
97878a40 AS |
166 | /* |
167 | * Ensure discovery message's signature is correct | |
168 | * | |
169 | * If signature is incorrect and there is no working link to the node, | |
170 | * accept the new signature but invalidate all existing links to the | |
171 | * node so they won't re-activate without a new discovery message. | |
172 | * | |
173 | * If signature is incorrect and the requested link to the node is | |
174 | * working, accept the new signature. (This is an instance of delayed | |
175 | * rediscovery, where a link endpoint was able to re-establish contact | |
176 | * with its peer endpoint on a node that rebooted before receiving a | |
177 | * discovery message from that node.) | |
178 | * | |
179 | * If signature is incorrect and there is a working link to the node | |
180 | * that is not the requested link, reject the request (must be from | |
181 | * a duplicate node). | |
182 | */ | |
183 | if (signature != n_ptr->signature) { | |
184 | if (n_ptr->working_links == 0) { | |
185 | struct tipc_link *curr_link; | |
186 | int i; | |
187 | ||
188 | for (i = 0; i < MAX_BEARERS; i++) { | |
189 | curr_link = n_ptr->links[i]; | |
190 | if (curr_link) { | |
191 | memset(&curr_link->media_addr, 0, | |
192 | sizeof(media_addr)); | |
193 | tipc_link_reset(curr_link); | |
194 | } | |
195 | } | |
196 | addr_mismatch = (link != NULL); | |
197 | } else if (tipc_link_is_up(link) && !addr_mismatch) { | |
198 | /* delayed rediscovery */ | |
199 | } else { | |
200 | disc_dupl_alert(b_ptr, orig, &media_addr); | |
a728750e AS |
201 | tipc_node_unlock(n_ptr); |
202 | return; | |
b97bf3fd | 203 | } |
97878a40 | 204 | n_ptr->signature = signature; |
a728750e AS |
205 | } |
206 | ||
207 | /* | |
208 | * Ensure requesting node's media address is correct | |
209 | * | |
210 | * If media address doesn't match and the link is working, reject the | |
211 | * request (must be from a duplicate node). | |
212 | * | |
213 | * If media address doesn't match and the link is not working, accept | |
214 | * the new media address and reset the link to ensure it starts up | |
215 | * cleanly. | |
216 | */ | |
97878a40 AS |
217 | if (addr_mismatch) { |
218 | if (tipc_link_is_up(link)) { | |
a728750e AS |
219 | disc_dupl_alert(b_ptr, orig, &media_addr); |
220 | tipc_node_unlock(n_ptr); | |
b97bf3fd | 221 | return; |
97878a40 AS |
222 | } else { |
223 | memcpy(&link->media_addr, &media_addr, | |
224 | sizeof(media_addr)); | |
225 | tipc_link_reset(link); | |
226 | } | |
227 | } | |
228 | ||
229 | /* Create a link endpoint for this bearer, if necessary */ | |
230 | if (!link) { | |
231 | link = tipc_link_create(n_ptr, b_ptr, &media_addr); | |
232 | if (!link) { | |
233 | tipc_node_unlock(n_ptr); | |
234 | return; | |
b97bf3fd | 235 | } |
a728750e AS |
236 | } |
237 | ||
238 | /* Accept discovery message & send response, if necessary */ | |
239 | link_fully_up = link_working_working(link); | |
fa2bae2d | 240 | |
512137ee | 241 | if ((type == DSC_REQ_MSG) && !link_fully_up) { |
16470111 | 242 | rbuf = tipc_disc_init_msg(DSC_RESP_MSG, b_ptr); |
fa2bae2d | 243 | if (rbuf) { |
3c294cb3 | 244 | tipc_bearer_send(b_ptr, rbuf, &media_addr); |
5f6d9123 | 245 | kfree_skb(rbuf); |
fa2bae2d | 246 | } |
b97bf3fd | 247 | } |
fa2bae2d AS |
248 | |
249 | tipc_node_unlock(n_ptr); | |
b97bf3fd PL |
250 | } |
251 | ||
b97bf3fd | 252 | /** |
1209966c | 253 | * disc_update - update frequency of periodic link setup requests |
b97bf3fd | 254 | * @req: ptr to link request structure |
972a77fb AS |
255 | * |
256 | * Reinitiates discovery process if discovery object has no associated nodes | |
257 | * and is either not currently searching or is searching at a slow rate | |
b97bf3fd | 258 | */ |
a18c4bc3 | 259 | static void disc_update(struct tipc_link_req *req) |
b97bf3fd | 260 | { |
972a77fb AS |
261 | if (!req->num_nodes) { |
262 | if ((req->timer_intv == TIPC_LINK_REQ_INACTIVE) || | |
263 | (req->timer_intv > TIPC_LINK_REQ_FAST)) { | |
264 | req->timer_intv = TIPC_LINK_REQ_INIT; | |
b97bf3fd PL |
265 | k_start_timer(&req->timer, req->timer_intv); |
266 | } | |
b97bf3fd | 267 | } |
c4307285 | 268 | } |
b97bf3fd | 269 | |
1209966c AS |
270 | /** |
271 | * tipc_disc_add_dest - increment set of discovered nodes | |
272 | * @req: ptr to link request structure | |
273 | */ | |
a18c4bc3 | 274 | void tipc_disc_add_dest(struct tipc_link_req *req) |
1209966c | 275 | { |
f9a2c80b | 276 | spin_lock_bh(&req->lock); |
1209966c | 277 | req->num_nodes++; |
f9a2c80b | 278 | spin_unlock_bh(&req->lock); |
1209966c AS |
279 | } |
280 | ||
281 | /** | |
282 | * tipc_disc_remove_dest - decrement set of discovered nodes | |
283 | * @req: ptr to link request structure | |
284 | */ | |
a18c4bc3 | 285 | void tipc_disc_remove_dest(struct tipc_link_req *req) |
1209966c | 286 | { |
f9a2c80b | 287 | spin_lock_bh(&req->lock); |
1209966c AS |
288 | req->num_nodes--; |
289 | disc_update(req); | |
f9a2c80b | 290 | spin_unlock_bh(&req->lock); |
1209966c AS |
291 | } |
292 | ||
b97bf3fd PL |
293 | /** |
294 | * disc_timeout - send a periodic link setup request | |
295 | * @req: ptr to link request structure | |
c4307285 | 296 | * |
b97bf3fd PL |
297 | * Called whenever a link setup request timer associated with a bearer expires. |
298 | */ | |
a18c4bc3 | 299 | static void disc_timeout(struct tipc_link_req *req) |
b97bf3fd | 300 | { |
972a77fb AS |
301 | int max_delay; |
302 | ||
f9a2c80b | 303 | spin_lock_bh(&req->lock); |
b97bf3fd | 304 | |
972a77fb | 305 | /* Stop searching if only desired node has been found */ |
16470111 | 306 | if (tipc_node(req->bearer->domain) && req->num_nodes) { |
972a77fb AS |
307 | req->timer_intv = TIPC_LINK_REQ_INACTIVE; |
308 | goto exit; | |
b97bf3fd | 309 | } |
b97bf3fd | 310 | |
972a77fb AS |
311 | /* |
312 | * Send discovery message, then update discovery timer | |
313 | * | |
314 | * Keep doubling time between requests until limit is reached; | |
315 | * hold at fast polling rate if don't have any associated nodes, | |
316 | * otherwise hold at slow polling rate | |
317 | */ | |
512137ee EH |
318 | tipc_bearer_send(req->bearer, req->buf, &req->dest); |
319 | ||
972a77fb AS |
320 | |
321 | req->timer_intv *= 2; | |
322 | if (req->num_nodes) | |
323 | max_delay = TIPC_LINK_REQ_SLOW; | |
324 | else | |
325 | max_delay = TIPC_LINK_REQ_FAST; | |
326 | if (req->timer_intv > max_delay) | |
327 | req->timer_intv = max_delay; | |
328 | ||
329 | k_start_timer(&req->timer, req->timer_intv); | |
330 | exit: | |
f9a2c80b | 331 | spin_unlock_bh(&req->lock); |
b97bf3fd PL |
332 | } |
333 | ||
334 | /** | |
3a777ff8 | 335 | * tipc_disc_create - create object to send periodic link setup requests |
b97bf3fd PL |
336 | * @b_ptr: ptr to bearer issuing requests |
337 | * @dest: destination address for request messages | |
66e019a6 | 338 | * @dest_domain: network domain to which links can be established |
c4307285 | 339 | * |
3a777ff8 | 340 | * Returns 0 if successful, otherwise -errno. |
b97bf3fd | 341 | */ |
16470111 | 342 | int tipc_disc_create(struct tipc_bearer *b_ptr, struct tipc_media_addr *dest) |
b97bf3fd | 343 | { |
a18c4bc3 | 344 | struct tipc_link_req *req; |
b97bf3fd | 345 | |
9df3f3d2 | 346 | req = kmalloc(sizeof(*req), GFP_ATOMIC); |
b97bf3fd | 347 | if (!req) |
3a777ff8 | 348 | return -ENOMEM; |
b97bf3fd | 349 | |
16470111 | 350 | req->buf = tipc_disc_init_msg(DSC_REQ_MSG, b_ptr); |
b97bf3fd PL |
351 | if (!req->buf) { |
352 | kfree(req); | |
3a777ff8 | 353 | return -ENOMSG; |
b97bf3fd PL |
354 | } |
355 | ||
356 | memcpy(&req->dest, dest, sizeof(*dest)); | |
357 | req->bearer = b_ptr; | |
1209966c | 358 | req->num_nodes = 0; |
b97bf3fd | 359 | req->timer_intv = TIPC_LINK_REQ_INIT; |
f9a2c80b | 360 | spin_lock_init(&req->lock); |
b97bf3fd PL |
361 | k_init_timer(&req->timer, (Handler)disc_timeout, (unsigned long)req); |
362 | k_start_timer(&req->timer, req->timer_intv); | |
3a777ff8 | 363 | b_ptr->link_req = req; |
512137ee | 364 | tipc_bearer_send(req->bearer, req->buf, &req->dest); |
3a777ff8 AS |
365 | return 0; |
366 | } | |
367 | ||
368 | /** | |
369 | * tipc_disc_delete - destroy object sending periodic link setup requests | |
370 | * @req: ptr to link request structure | |
371 | */ | |
a18c4bc3 | 372 | void tipc_disc_delete(struct tipc_link_req *req) |
3a777ff8 AS |
373 | { |
374 | k_cancel_timer(&req->timer); | |
375 | k_term_timer(&req->timer); | |
5f6d9123 | 376 | kfree_skb(req->buf); |
3a777ff8 | 377 | kfree(req); |
c4307285 | 378 | } |