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 * @mtyp: message type (request or response)
78 * @b: ptr to bearer issuing message
79 */
tipc_disc_init_msg(struct net * net,struct sk_buff * skb,u32 mtyp,struct tipc_bearer * b)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
tipc_disc_msg_xmit(struct net * net,u32 mtyp,u32 dst,u32 src,u32 sugg_addr,struct tipc_media_addr * maddr,struct tipc_bearer * b)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 */
disc_dupl_alert(struct tipc_bearer * b,u32 node_addr,struct tipc_media_addr * media_addr)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 */
tipc_disc_addr_trial_msg(struct tipc_discoverer * d,struct tipc_media_addr * maddr,struct tipc_bearer * b,u32 dst,u32 src,u32 sugg_addr,u8 * peer_id,int mtyp)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 u32 self = tipc_own_addr(net);
151 bool trial = time_before(jiffies, tn->addr_trial_end) && !self;
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 schedule_work(&tn->work);
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 */
tipc_disc_rcv(struct net * net,struct sk_buff * skb,struct tipc_bearer * b)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 if (skb_linearize(skb)) {
214 kfree_skb(skb);
215 return;
216 }
217 hdr = buf_msg(skb);
218
219 if (caps & TIPC_NODE_ID128)
220 memcpy(peer_id, msg_node_id(hdr), NODE_ID_LEN);
221 else
222 sprintf(peer_id, "%x", src);
223
224 err = b->media->msg2addr(b, &maddr, msg_media_addr(hdr));
225 kfree_skb(skb);
226 if (err || maddr.broadcast) {
227 pr_warn_ratelimited("Rcv corrupt discovery message\n");
228 return;
229 }
230 /* Ignore discovery messages from own node */
231 if (!memcmp(&maddr, &b->addr, sizeof(maddr)))
232 return;
233 if (net_id != tn->net_id)
234 return;
235 if (tipc_disc_addr_trial_msg(b->disc, &maddr, b, dst,
236 src, sugg, peer_id, mtyp))
237 return;
238 self = tipc_own_addr(net);
239
240 /* Message from somebody using this node's address */
241 if (in_own_node(net, src)) {
242 disc_dupl_alert(b, self, &maddr);
243 return;
244 }
245 if (!tipc_in_scope(legacy, dst, self))
246 return;
247 if (!tipc_in_scope(legacy, b->domain, src))
248 return;
249 tipc_node_check_dest(net, src, peer_id, b, caps, signature, pnet_hash,
250 &maddr, &respond, &dupl_addr);
251 if (dupl_addr)
252 disc_dupl_alert(b, src, &maddr);
253 if (!respond)
254 return;
255 if (mtyp != DSC_REQ_MSG)
256 return;
257 tipc_disc_msg_xmit(net, DSC_RESP_MSG, src, self, 0, &maddr, b);
258 }
259
260 /* tipc_disc_add_dest - increment set of discovered nodes
261 */
tipc_disc_add_dest(struct tipc_discoverer * d)262 void tipc_disc_add_dest(struct tipc_discoverer *d)
263 {
264 spin_lock_bh(&d->lock);
265 d->num_nodes++;
266 spin_unlock_bh(&d->lock);
267 }
268
269 /* tipc_disc_remove_dest - decrement set of discovered nodes
270 */
tipc_disc_remove_dest(struct tipc_discoverer * d)271 void tipc_disc_remove_dest(struct tipc_discoverer *d)
272 {
273 int intv, num;
274
275 spin_lock_bh(&d->lock);
276 d->num_nodes--;
277 num = d->num_nodes;
278 intv = d->timer_intv;
279 if (!num && (intv == TIPC_DISC_INACTIVE || intv > TIPC_DISC_FAST)) {
280 d->timer_intv = TIPC_DISC_INIT;
281 mod_timer(&d->timer, jiffies + d->timer_intv);
282 }
283 spin_unlock_bh(&d->lock);
284 }
285
286 /* tipc_disc_timeout - send a periodic link setup request
287 * Called whenever a link setup request timer associated with a bearer expires.
288 * - Keep doubling time between sent request until limit is reached;
289 * - Hold at fast polling rate if we don't have any associated nodes
290 * - Otherwise hold at slow polling rate
291 */
tipc_disc_timeout(struct timer_list * t)292 static void tipc_disc_timeout(struct timer_list *t)
293 {
294 struct tipc_discoverer *d = from_timer(d, t, timer);
295 struct tipc_net *tn = tipc_net(d->net);
296 struct tipc_media_addr maddr;
297 struct sk_buff *skb = NULL;
298 struct net *net = d->net;
299 u32 bearer_id;
300
301 spin_lock_bh(&d->lock);
302
303 /* Stop searching if only desired node has been found */
304 if (tipc_node(d->domain) && d->num_nodes) {
305 d->timer_intv = TIPC_DISC_INACTIVE;
306 goto exit;
307 }
308
309 /* Did we just leave trial period ? */
310 if (!time_before(jiffies, tn->addr_trial_end) && !tipc_own_addr(net)) {
311 mod_timer(&d->timer, jiffies + TIPC_DISC_INIT);
312 spin_unlock_bh(&d->lock);
313 schedule_work(&tn->work);
314 return;
315 }
316
317 /* Adjust timeout interval according to discovery phase */
318 if (time_before(jiffies, tn->addr_trial_end)) {
319 d->timer_intv = TIPC_DISC_INIT;
320 } else {
321 d->timer_intv *= 2;
322 if (d->num_nodes && d->timer_intv > TIPC_DISC_SLOW)
323 d->timer_intv = TIPC_DISC_SLOW;
324 else if (!d->num_nodes && d->timer_intv > TIPC_DISC_FAST)
325 d->timer_intv = TIPC_DISC_FAST;
326 msg_set_type(buf_msg(d->skb), DSC_REQ_MSG);
327 msg_set_prevnode(buf_msg(d->skb), tn->trial_addr);
328 }
329
330 mod_timer(&d->timer, jiffies + d->timer_intv);
331 memcpy(&maddr, &d->dest, sizeof(maddr));
332 skb = skb_clone(d->skb, GFP_ATOMIC);
333 bearer_id = d->bearer_id;
334 exit:
335 spin_unlock_bh(&d->lock);
336 if (skb)
337 tipc_bearer_xmit_skb(net, bearer_id, skb, &maddr);
338 }
339
340 /**
341 * tipc_disc_create - create object to send periodic link setup requests
342 * @net: the applicable net namespace
343 * @b: ptr to bearer issuing requests
344 * @dest: destination address for request messages
345 * @skb: pointer to created frame
346 *
347 * Returns 0 if successful, otherwise -errno.
348 */
tipc_disc_create(struct net * net,struct tipc_bearer * b,struct tipc_media_addr * dest,struct sk_buff ** skb)349 int tipc_disc_create(struct net *net, struct tipc_bearer *b,
350 struct tipc_media_addr *dest, struct sk_buff **skb)
351 {
352 struct tipc_net *tn = tipc_net(net);
353 struct tipc_discoverer *d;
354
355 d = kmalloc(sizeof(*d), GFP_ATOMIC);
356 if (!d)
357 return -ENOMEM;
358 d->skb = tipc_buf_acquire(MAX_H_SIZE + NODE_ID_LEN, GFP_ATOMIC);
359 if (!d->skb) {
360 kfree(d);
361 return -ENOMEM;
362 }
363 tipc_disc_init_msg(net, d->skb, DSC_REQ_MSG, b);
364
365 /* Do we need an address trial period first ? */
366 if (!tipc_own_addr(net)) {
367 tn->addr_trial_end = jiffies + msecs_to_jiffies(1000);
368 msg_set_type(buf_msg(d->skb), DSC_TRIAL_MSG);
369 }
370 memcpy(&d->dest, dest, sizeof(*dest));
371 d->net = net;
372 d->bearer_id = b->identity;
373 d->domain = b->domain;
374 d->num_nodes = 0;
375 d->timer_intv = TIPC_DISC_INIT;
376 spin_lock_init(&d->lock);
377 timer_setup(&d->timer, tipc_disc_timeout, 0);
378 mod_timer(&d->timer, jiffies + d->timer_intv);
379 b->disc = d;
380 *skb = skb_clone(d->skb, GFP_ATOMIC);
381 return 0;
382 }
383
384 /**
385 * tipc_disc_delete - destroy object sending periodic link setup requests
386 * @d: ptr to link duest structure
387 */
tipc_disc_delete(struct tipc_discoverer * d)388 void tipc_disc_delete(struct tipc_discoverer *d)
389 {
390 del_timer_sync(&d->timer);
391 kfree_skb(d->skb);
392 kfree(d);
393 }
394
395 /**
396 * tipc_disc_reset - reset object to send periodic link setup requests
397 * @net: the applicable net namespace
398 * @b: ptr to bearer issuing requests
399 */
tipc_disc_reset(struct net * net,struct tipc_bearer * b)400 void tipc_disc_reset(struct net *net, struct tipc_bearer *b)
401 {
402 struct tipc_discoverer *d = b->disc;
403 struct tipc_media_addr maddr;
404 struct sk_buff *skb;
405
406 spin_lock_bh(&d->lock);
407 tipc_disc_init_msg(net, d->skb, DSC_REQ_MSG, b);
408 d->net = net;
409 d->bearer_id = b->identity;
410 d->domain = b->domain;
411 d->num_nodes = 0;
412 d->timer_intv = TIPC_DISC_INIT;
413 memcpy(&maddr, &d->dest, sizeof(maddr));
414 mod_timer(&d->timer, jiffies + d->timer_intv);
415 skb = skb_clone(d->skb, GFP_ATOMIC);
416 spin_unlock_bh(&d->lock);
417 if (skb)
418 tipc_bearer_xmit_skb(net, b->identity, skb, &maddr);
419 }
420