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 | * @skb: buffer containing message |
78 | * @mtyp: message type (request or response) |
79 | * @b: ptr to bearer issuing message |
80 | */ |
81 | static void tipc_disc_init_msg(struct net *net, struct sk_buff *skb, |
82 | u32 mtyp, struct tipc_bearer *b) |
83 | { |
84 | struct tipc_net *tn = tipc_net(net); |
85 | u32 dest_domain = b->domain; |
86 | struct tipc_msg *hdr; |
87 | |
88 | hdr = buf_msg(skb); |
89 | tipc_msg_init(own_addr: tn->trial_addr, m: hdr, LINK_CONFIG, type: mtyp, |
90 | MAX_H_SIZE, destnode: dest_domain); |
91 | msg_set_size(m: hdr, MAX_H_SIZE + NODE_ID_LEN); |
92 | msg_set_non_seq(m: hdr, n: 1); |
93 | msg_set_node_sig(m: hdr, n: tn->random); |
94 | msg_set_node_capabilities(m: hdr, TIPC_NODE_CAPABILITIES); |
95 | msg_set_dest_domain(m: hdr, n: dest_domain); |
96 | msg_set_bc_netid(m: hdr, id: tn->net_id); |
97 | b->media->addr2msg(msg_media_addr(m: hdr), &b->addr); |
98 | msg_set_peer_net_hash(m: hdr, n: tipc_net_hash_mixes(net, tn_rand: tn->random)); |
99 | msg_set_node_id(hdr, id: tipc_own_id(net)); |
100 | } |
101 | |
102 | static void tipc_disc_msg_xmit(struct net *net, u32 mtyp, u32 dst, |
103 | u32 src, u32 sugg_addr, |
104 | struct tipc_media_addr *maddr, |
105 | struct tipc_bearer *b) |
106 | { |
107 | struct tipc_msg *hdr; |
108 | struct sk_buff *skb; |
109 | |
110 | skb = tipc_buf_acquire(MAX_H_SIZE + NODE_ID_LEN, GFP_ATOMIC); |
111 | if (!skb) |
112 | return; |
113 | hdr = buf_msg(skb); |
114 | tipc_disc_init_msg(net, skb, mtyp, b); |
115 | msg_set_sugg_node_addr(m: hdr, n: sugg_addr); |
116 | msg_set_dest_domain(m: hdr, n: dst); |
117 | tipc_bearer_xmit_skb(net, bearer_id: b->identity, skb, dest: maddr); |
118 | } |
119 | |
120 | /** |
121 | * disc_dupl_alert - issue node address duplication alert |
122 | * @b: pointer to bearer detecting duplication |
123 | * @node_addr: duplicated node address |
124 | * @media_addr: media address advertised by duplicated node |
125 | */ |
126 | static void disc_dupl_alert(struct tipc_bearer *b, u32 node_addr, |
127 | struct tipc_media_addr *media_addr) |
128 | { |
129 | char media_addr_str[64]; |
130 | |
131 | tipc_media_addr_printf(buf: media_addr_str, len: sizeof(media_addr_str), |
132 | a: media_addr); |
133 | pr_warn("Duplicate %x using %s seen on <%s>\n" , node_addr, |
134 | media_addr_str, b->name); |
135 | } |
136 | |
137 | /* tipc_disc_addr_trial(): - handle an address uniqueness trial from peer |
138 | * Returns true if message should be dropped by caller, i.e., if it is a |
139 | * trial message or we are inside trial period. Otherwise false. |
140 | */ |
141 | static bool tipc_disc_addr_trial_msg(struct tipc_discoverer *d, |
142 | struct tipc_media_addr *maddr, |
143 | struct tipc_bearer *b, |
144 | u32 dst, u32 src, |
145 | u32 sugg_addr, |
146 | u8 *peer_id, |
147 | int mtyp) |
148 | { |
149 | struct net *net = d->net; |
150 | struct tipc_net *tn = tipc_net(net); |
151 | u32 self = tipc_own_addr(net); |
152 | bool trial = time_before(jiffies, tn->addr_trial_end) && !self; |
153 | |
154 | if (mtyp == DSC_TRIAL_FAIL_MSG) { |
155 | if (!trial) |
156 | return true; |
157 | |
158 | /* Ignore if somebody else already gave new suggestion */ |
159 | if (dst != tn->trial_addr) |
160 | return true; |
161 | |
162 | /* Otherwise update trial address and restart trial period */ |
163 | tn->trial_addr = sugg_addr; |
164 | msg_set_prevnode(m: buf_msg(skb: d->skb), a: sugg_addr); |
165 | tn->addr_trial_end = jiffies + msecs_to_jiffies(m: 1000); |
166 | return true; |
167 | } |
168 | |
169 | /* Apply trial address if we just left trial period */ |
170 | if (!trial && !self) { |
171 | schedule_work(work: &tn->work); |
172 | msg_set_prevnode(m: buf_msg(skb: d->skb), a: tn->trial_addr); |
173 | msg_set_type(m: buf_msg(skb: d->skb), DSC_REQ_MSG); |
174 | } |
175 | |
176 | /* Accept regular link requests/responses only after trial period */ |
177 | if (mtyp != DSC_TRIAL_MSG) |
178 | return trial; |
179 | |
180 | sugg_addr = tipc_node_try_addr(net, id: peer_id, addr: src); |
181 | if (sugg_addr) |
182 | tipc_disc_msg_xmit(net, DSC_TRIAL_FAIL_MSG, dst: src, |
183 | src: self, sugg_addr, maddr, b); |
184 | return true; |
185 | } |
186 | |
187 | /** |
188 | * tipc_disc_rcv - handle incoming discovery message (request or response) |
189 | * @net: applicable net namespace |
190 | * @skb: buffer containing message |
191 | * @b: bearer that message arrived on |
192 | */ |
193 | void tipc_disc_rcv(struct net *net, struct sk_buff *skb, |
194 | struct tipc_bearer *b) |
195 | { |
196 | struct tipc_net *tn = tipc_net(net); |
197 | struct tipc_msg *hdr = buf_msg(skb); |
198 | u32 pnet_hash = msg_peer_net_hash(m: hdr); |
199 | u16 caps = msg_node_capabilities(m: hdr); |
200 | bool legacy = tn->legacy_addr_format; |
201 | u32 sugg = msg_sugg_node_addr(m: hdr); |
202 | u32 signature = msg_node_sig(m: hdr); |
203 | u8 peer_id[NODE_ID_LEN] = {0,}; |
204 | u32 dst = msg_dest_domain(m: hdr); |
205 | u32 net_id = msg_bc_netid(m: hdr); |
206 | struct tipc_media_addr maddr; |
207 | u32 src = msg_prevnode(m: hdr); |
208 | u32 mtyp = msg_type(m: hdr); |
209 | bool dupl_addr = false; |
210 | bool respond = false; |
211 | u32 self; |
212 | int err; |
213 | |
214 | if (skb_linearize(skb)) { |
215 | kfree_skb(skb); |
216 | return; |
217 | } |
218 | hdr = buf_msg(skb); |
219 | |
220 | if (caps & TIPC_NODE_ID128) |
221 | memcpy(peer_id, msg_node_id(hdr), NODE_ID_LEN); |
222 | else |
223 | sprintf(buf: peer_id, fmt: "%x" , src); |
224 | |
225 | err = b->media->msg2addr(b, &maddr, msg_media_addr(m: hdr)); |
226 | kfree_skb(skb); |
227 | if (err || maddr.broadcast) { |
228 | pr_warn_ratelimited("Rcv corrupt discovery message\n" ); |
229 | return; |
230 | } |
231 | /* Ignore discovery messages from own node */ |
232 | if (!memcmp(p: &maddr, q: &b->addr, size: sizeof(maddr))) |
233 | return; |
234 | if (net_id != tn->net_id) |
235 | return; |
236 | if (tipc_disc_addr_trial_msg(d: b->disc, maddr: &maddr, b, dst, |
237 | src, sugg_addr: sugg, peer_id, mtyp)) |
238 | return; |
239 | self = tipc_own_addr(net); |
240 | |
241 | /* Message from somebody using this node's address */ |
242 | if (in_own_node(net, addr: src)) { |
243 | disc_dupl_alert(b, node_addr: self, media_addr: &maddr); |
244 | return; |
245 | } |
246 | if (!tipc_in_scope(legacy_format: legacy, domain: dst, addr: self)) |
247 | return; |
248 | if (!tipc_in_scope(legacy_format: legacy, domain: b->domain, addr: src)) |
249 | return; |
250 | tipc_node_check_dest(net, onode: src, peer_id128: peer_id, bearer: b, capabilities: caps, signature, hash_mixes: pnet_hash, |
251 | maddr: &maddr, respond: &respond, dupl_addr: &dupl_addr); |
252 | if (dupl_addr) |
253 | disc_dupl_alert(b, node_addr: src, media_addr: &maddr); |
254 | if (!respond) |
255 | return; |
256 | if (mtyp != DSC_REQ_MSG) |
257 | return; |
258 | tipc_disc_msg_xmit(net, DSC_RESP_MSG, dst: src, src: self, sugg_addr: 0, maddr: &maddr, b); |
259 | } |
260 | |
261 | /* tipc_disc_add_dest - increment set of discovered nodes |
262 | */ |
263 | void tipc_disc_add_dest(struct tipc_discoverer *d) |
264 | { |
265 | spin_lock_bh(lock: &d->lock); |
266 | d->num_nodes++; |
267 | spin_unlock_bh(lock: &d->lock); |
268 | } |
269 | |
270 | /* tipc_disc_remove_dest - decrement set of discovered nodes |
271 | */ |
272 | void tipc_disc_remove_dest(struct tipc_discoverer *d) |
273 | { |
274 | int intv, num; |
275 | |
276 | spin_lock_bh(lock: &d->lock); |
277 | d->num_nodes--; |
278 | num = d->num_nodes; |
279 | intv = d->timer_intv; |
280 | if (!num && (intv == TIPC_DISC_INACTIVE || intv > TIPC_DISC_FAST)) { |
281 | d->timer_intv = TIPC_DISC_INIT; |
282 | mod_timer(timer: &d->timer, expires: jiffies + d->timer_intv); |
283 | } |
284 | spin_unlock_bh(lock: &d->lock); |
285 | } |
286 | |
287 | /* tipc_disc_timeout - send a periodic link setup request |
288 | * Called whenever a link setup request timer associated with a bearer expires. |
289 | * - Keep doubling time between sent request until limit is reached; |
290 | * - Hold at fast polling rate if we don't have any associated nodes |
291 | * - Otherwise hold at slow polling rate |
292 | */ |
293 | static void tipc_disc_timeout(struct timer_list *t) |
294 | { |
295 | struct tipc_discoverer *d = from_timer(d, t, timer); |
296 | struct tipc_net *tn = tipc_net(net: d->net); |
297 | struct tipc_media_addr maddr; |
298 | struct sk_buff *skb = NULL; |
299 | struct net *net = d->net; |
300 | u32 bearer_id; |
301 | |
302 | spin_lock_bh(lock: &d->lock); |
303 | |
304 | /* Stop searching if only desired node has been found */ |
305 | if (tipc_node(addr: d->domain) && d->num_nodes) { |
306 | d->timer_intv = TIPC_DISC_INACTIVE; |
307 | goto exit; |
308 | } |
309 | |
310 | /* Did we just leave trial period ? */ |
311 | if (!time_before(jiffies, tn->addr_trial_end) && !tipc_own_addr(net)) { |
312 | mod_timer(timer: &d->timer, expires: jiffies + TIPC_DISC_INIT); |
313 | spin_unlock_bh(lock: &d->lock); |
314 | schedule_work(work: &tn->work); |
315 | return; |
316 | } |
317 | |
318 | /* Adjust timeout interval according to discovery phase */ |
319 | if (time_before(jiffies, tn->addr_trial_end)) { |
320 | d->timer_intv = TIPC_DISC_INIT; |
321 | } else { |
322 | d->timer_intv *= 2; |
323 | if (d->num_nodes && d->timer_intv > TIPC_DISC_SLOW) |
324 | d->timer_intv = TIPC_DISC_SLOW; |
325 | else if (!d->num_nodes && d->timer_intv > TIPC_DISC_FAST) |
326 | d->timer_intv = TIPC_DISC_FAST; |
327 | msg_set_type(m: buf_msg(skb: d->skb), DSC_REQ_MSG); |
328 | msg_set_prevnode(m: buf_msg(skb: d->skb), a: tn->trial_addr); |
329 | } |
330 | |
331 | mod_timer(timer: &d->timer, expires: jiffies + d->timer_intv); |
332 | memcpy(&maddr, &d->dest, sizeof(maddr)); |
333 | skb = skb_clone(skb: d->skb, GFP_ATOMIC); |
334 | bearer_id = d->bearer_id; |
335 | exit: |
336 | spin_unlock_bh(lock: &d->lock); |
337 | if (skb) |
338 | tipc_bearer_xmit_skb(net, bearer_id, skb, dest: &maddr); |
339 | } |
340 | |
341 | /** |
342 | * tipc_disc_create - create object to send periodic link setup requests |
343 | * @net: the applicable net namespace |
344 | * @b: ptr to bearer issuing requests |
345 | * @dest: destination address for request messages |
346 | * @skb: pointer to created frame |
347 | * |
348 | * Return: 0 if successful, otherwise -errno. |
349 | */ |
350 | int tipc_disc_create(struct net *net, struct tipc_bearer *b, |
351 | struct tipc_media_addr *dest, struct sk_buff **skb) |
352 | { |
353 | struct tipc_net *tn = tipc_net(net); |
354 | struct tipc_discoverer *d; |
355 | |
356 | d = kmalloc(size: sizeof(*d), GFP_ATOMIC); |
357 | if (!d) |
358 | return -ENOMEM; |
359 | d->skb = tipc_buf_acquire(MAX_H_SIZE + NODE_ID_LEN, GFP_ATOMIC); |
360 | if (!d->skb) { |
361 | kfree(objp: d); |
362 | return -ENOMEM; |
363 | } |
364 | tipc_disc_init_msg(net, skb: d->skb, DSC_REQ_MSG, b); |
365 | |
366 | /* Do we need an address trial period first ? */ |
367 | if (!tipc_own_addr(net)) { |
368 | tn->addr_trial_end = jiffies + msecs_to_jiffies(m: 1000); |
369 | msg_set_type(m: buf_msg(skb: d->skb), DSC_TRIAL_MSG); |
370 | } |
371 | memcpy(&d->dest, dest, sizeof(*dest)); |
372 | d->net = net; |
373 | d->bearer_id = b->identity; |
374 | d->domain = b->domain; |
375 | d->num_nodes = 0; |
376 | d->timer_intv = TIPC_DISC_INIT; |
377 | spin_lock_init(&d->lock); |
378 | timer_setup(&d->timer, tipc_disc_timeout, 0); |
379 | mod_timer(timer: &d->timer, expires: jiffies + d->timer_intv); |
380 | b->disc = d; |
381 | *skb = skb_clone(skb: d->skb, GFP_ATOMIC); |
382 | return 0; |
383 | } |
384 | |
385 | /** |
386 | * tipc_disc_delete - destroy object sending periodic link setup requests |
387 | * @d: ptr to link dest structure |
388 | */ |
389 | void tipc_disc_delete(struct tipc_discoverer *d) |
390 | { |
391 | timer_shutdown_sync(timer: &d->timer); |
392 | kfree_skb(skb: d->skb); |
393 | kfree(objp: d); |
394 | } |
395 | |
396 | /** |
397 | * tipc_disc_reset - reset object to send periodic link setup requests |
398 | * @net: the applicable net namespace |
399 | * @b: ptr to bearer issuing requests |
400 | */ |
401 | void tipc_disc_reset(struct net *net, struct tipc_bearer *b) |
402 | { |
403 | struct tipc_discoverer *d = b->disc; |
404 | struct tipc_media_addr maddr; |
405 | struct sk_buff *skb; |
406 | |
407 | spin_lock_bh(lock: &d->lock); |
408 | tipc_disc_init_msg(net, skb: d->skb, DSC_REQ_MSG, b); |
409 | d->net = net; |
410 | d->bearer_id = b->identity; |
411 | d->domain = b->domain; |
412 | d->num_nodes = 0; |
413 | d->timer_intv = TIPC_DISC_INIT; |
414 | memcpy(&maddr, &d->dest, sizeof(maddr)); |
415 | mod_timer(timer: &d->timer, expires: jiffies + d->timer_intv); |
416 | skb = skb_clone(skb: d->skb, GFP_ATOMIC); |
417 | spin_unlock_bh(lock: &d->lock); |
418 | if (skb) |
419 | tipc_bearer_xmit_skb(net, bearer_id: b->identity, skb, dest: &maddr); |
420 | } |
421 | |