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