xref: /openbmc/linux/net/tipc/bcast.c (revision 82003e04)
1 /*
2  * net/tipc/bcast.c: TIPC broadcast code
3  *
4  * Copyright (c) 2004-2006, 2014-2015, Ericsson AB
5  * Copyright (c) 2004, Intel Corporation.
6  * Copyright (c) 2005, 2010-2011, Wind River Systems
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. Neither the names of the copyright holders nor the names of its
18  *    contributors may be used to endorse or promote products derived from
19  *    this software without specific prior written permission.
20  *
21  * Alternatively, this software may be distributed under the terms of the
22  * GNU General Public License ("GPL") version 2 as published by the Free
23  * Software Foundation.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
26  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
29  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35  * POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 #include <linux/tipc_config.h>
39 #include "socket.h"
40 #include "msg.h"
41 #include "bcast.h"
42 #include "name_distr.h"
43 #include "link.h"
44 #include "node.h"
45 
46 #define	BCLINK_WIN_DEFAULT	50	/* bcast link window size (default) */
47 #define	BCLINK_WIN_MIN	        32	/* bcast minimum link window size */
48 
49 const char tipc_bclink_name[] = "broadcast-link";
50 
51 /**
52  * struct tipc_bc_base - base structure for keeping broadcast send state
53  * @link: broadcast send link structure
54  * @inputq: data input queue; will only carry SOCK_WAKEUP messages
55  * @dest: array keeping number of reachable destinations per bearer
56  * @primary_bearer: a bearer having links to all broadcast destinations, if any
57  */
58 struct tipc_bc_base {
59 	struct tipc_link *link;
60 	struct sk_buff_head inputq;
61 	int dests[MAX_BEARERS];
62 	int primary_bearer;
63 };
64 
65 static struct tipc_bc_base *tipc_bc_base(struct net *net)
66 {
67 	return tipc_net(net)->bcbase;
68 }
69 
70 int tipc_bcast_get_mtu(struct net *net)
71 {
72 	return tipc_link_mtu(tipc_bc_sndlink(net));
73 }
74 
75 /* tipc_bcbase_select_primary(): find a bearer with links to all destinations,
76  *                               if any, and make it primary bearer
77  */
78 static void tipc_bcbase_select_primary(struct net *net)
79 {
80 	struct tipc_bc_base *bb = tipc_bc_base(net);
81 	int all_dests =  tipc_link_bc_peers(bb->link);
82 	int i, mtu;
83 
84 	bb->primary_bearer = INVALID_BEARER_ID;
85 
86 	if (!all_dests)
87 		return;
88 
89 	for (i = 0; i < MAX_BEARERS; i++) {
90 		if (!bb->dests[i])
91 			continue;
92 
93 		mtu = tipc_bearer_mtu(net, i);
94 		if (mtu < tipc_link_mtu(bb->link))
95 			tipc_link_set_mtu(bb->link, mtu);
96 
97 		if (bb->dests[i] < all_dests)
98 			continue;
99 
100 		bb->primary_bearer = i;
101 
102 		/* Reduce risk that all nodes select same primary */
103 		if ((i ^ tipc_own_addr(net)) & 1)
104 			break;
105 	}
106 }
107 
108 void tipc_bcast_inc_bearer_dst_cnt(struct net *net, int bearer_id)
109 {
110 	struct tipc_bc_base *bb = tipc_bc_base(net);
111 
112 	tipc_bcast_lock(net);
113 	bb->dests[bearer_id]++;
114 	tipc_bcbase_select_primary(net);
115 	tipc_bcast_unlock(net);
116 }
117 
118 void tipc_bcast_dec_bearer_dst_cnt(struct net *net, int bearer_id)
119 {
120 	struct tipc_bc_base *bb = tipc_bc_base(net);
121 
122 	tipc_bcast_lock(net);
123 	bb->dests[bearer_id]--;
124 	tipc_bcbase_select_primary(net);
125 	tipc_bcast_unlock(net);
126 }
127 
128 /* tipc_bcbase_xmit - broadcast a packet queue across one or more bearers
129  *
130  * Note that number of reachable destinations, as indicated in the dests[]
131  * array, may transitionally differ from the number of destinations indicated
132  * in each sent buffer. We can sustain this. Excess destination nodes will
133  * drop and never acknowledge the unexpected packets, and missing destinations
134  * will either require retransmission (if they are just about to be added to
135  * the bearer), or be removed from the buffer's 'ackers' counter (if they
136  * just went down)
137  */
138 static void tipc_bcbase_xmit(struct net *net, struct sk_buff_head *xmitq)
139 {
140 	int bearer_id;
141 	struct tipc_bc_base *bb = tipc_bc_base(net);
142 	struct sk_buff *skb, *_skb;
143 	struct sk_buff_head _xmitq;
144 
145 	if (skb_queue_empty(xmitq))
146 		return;
147 
148 	/* The typical case: at least one bearer has links to all nodes */
149 	bearer_id = bb->primary_bearer;
150 	if (bearer_id >= 0) {
151 		tipc_bearer_bc_xmit(net, bearer_id, xmitq);
152 		return;
153 	}
154 
155 	/* We have to transmit across all bearers */
156 	skb_queue_head_init(&_xmitq);
157 	for (bearer_id = 0; bearer_id < MAX_BEARERS; bearer_id++) {
158 		if (!bb->dests[bearer_id])
159 			continue;
160 
161 		skb_queue_walk(xmitq, skb) {
162 			_skb = pskb_copy_for_clone(skb, GFP_ATOMIC);
163 			if (!_skb)
164 				break;
165 			__skb_queue_tail(&_xmitq, _skb);
166 		}
167 		tipc_bearer_bc_xmit(net, bearer_id, &_xmitq);
168 	}
169 	__skb_queue_purge(xmitq);
170 	__skb_queue_purge(&_xmitq);
171 }
172 
173 /* tipc_bcast_xmit - deliver buffer chain to all nodes in cluster
174  *                    and to identified node local sockets
175  * @net: the applicable net namespace
176  * @list: chain of buffers containing message
177  * Consumes the buffer chain, except when returning -ELINKCONG
178  * Returns 0 if success, otherwise errno: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE
179  */
180 int tipc_bcast_xmit(struct net *net, struct sk_buff_head *list)
181 {
182 	struct tipc_link *l = tipc_bc_sndlink(net);
183 	struct sk_buff_head xmitq, inputq, rcvq;
184 	int rc = 0;
185 
186 	__skb_queue_head_init(&rcvq);
187 	__skb_queue_head_init(&xmitq);
188 	skb_queue_head_init(&inputq);
189 
190 	/* Prepare message clone for local node */
191 	if (unlikely(!tipc_msg_reassemble(list, &rcvq)))
192 		return -EHOSTUNREACH;
193 
194 	tipc_bcast_lock(net);
195 	if (tipc_link_bc_peers(l))
196 		rc = tipc_link_xmit(l, list, &xmitq);
197 	tipc_bcast_unlock(net);
198 
199 	/* Don't send to local node if adding to link failed */
200 	if (unlikely(rc)) {
201 		__skb_queue_purge(&rcvq);
202 		return rc;
203 	}
204 
205 	/* Broadcast to all nodes, inluding local node */
206 	tipc_bcbase_xmit(net, &xmitq);
207 	tipc_sk_mcast_rcv(net, &rcvq, &inputq);
208 	__skb_queue_purge(list);
209 	return 0;
210 }
211 
212 /* tipc_bcast_rcv - receive a broadcast packet, and deliver to rcv link
213  *
214  * RCU is locked, no other locks set
215  */
216 int tipc_bcast_rcv(struct net *net, struct tipc_link *l, struct sk_buff *skb)
217 {
218 	struct tipc_msg *hdr = buf_msg(skb);
219 	struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
220 	struct sk_buff_head xmitq;
221 	int rc;
222 
223 	__skb_queue_head_init(&xmitq);
224 
225 	if (msg_mc_netid(hdr) != tipc_netid(net) || !tipc_link_is_up(l)) {
226 		kfree_skb(skb);
227 		return 0;
228 	}
229 
230 	tipc_bcast_lock(net);
231 	if (msg_user(hdr) == BCAST_PROTOCOL)
232 		rc = tipc_link_bc_nack_rcv(l, skb, &xmitq);
233 	else
234 		rc = tipc_link_rcv(l, skb, NULL);
235 	tipc_bcast_unlock(net);
236 
237 	tipc_bcbase_xmit(net, &xmitq);
238 
239 	/* Any socket wakeup messages ? */
240 	if (!skb_queue_empty(inputq))
241 		tipc_sk_rcv(net, inputq);
242 
243 	return rc;
244 }
245 
246 /* tipc_bcast_ack_rcv - receive and handle a broadcast acknowledge
247  *
248  * RCU is locked, no other locks set
249  */
250 void tipc_bcast_ack_rcv(struct net *net, struct tipc_link *l,
251 			struct tipc_msg *hdr)
252 {
253 	struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
254 	u16 acked = msg_bcast_ack(hdr);
255 	struct sk_buff_head xmitq;
256 
257 	/* Ignore bc acks sent by peer before bcast synch point was received */
258 	if (msg_bc_ack_invalid(hdr))
259 		return;
260 
261 	__skb_queue_head_init(&xmitq);
262 
263 	tipc_bcast_lock(net);
264 	tipc_link_bc_ack_rcv(l, acked, &xmitq);
265 	tipc_bcast_unlock(net);
266 
267 	tipc_bcbase_xmit(net, &xmitq);
268 
269 	/* Any socket wakeup messages ? */
270 	if (!skb_queue_empty(inputq))
271 		tipc_sk_rcv(net, inputq);
272 }
273 
274 /* tipc_bcast_synch_rcv -  check and update rcv link with peer's send state
275  *
276  * RCU is locked, no other locks set
277  */
278 int tipc_bcast_sync_rcv(struct net *net, struct tipc_link *l,
279 			struct tipc_msg *hdr)
280 {
281 	struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
282 	struct sk_buff_head xmitq;
283 	int rc = 0;
284 
285 	__skb_queue_head_init(&xmitq);
286 
287 	tipc_bcast_lock(net);
288 	if (msg_type(hdr) != STATE_MSG) {
289 		tipc_link_bc_init_rcv(l, hdr);
290 	} else if (!msg_bc_ack_invalid(hdr)) {
291 		tipc_link_bc_ack_rcv(l, msg_bcast_ack(hdr), &xmitq);
292 		rc = tipc_link_bc_sync_rcv(l, hdr, &xmitq);
293 	}
294 	tipc_bcast_unlock(net);
295 
296 	tipc_bcbase_xmit(net, &xmitq);
297 
298 	/* Any socket wakeup messages ? */
299 	if (!skb_queue_empty(inputq))
300 		tipc_sk_rcv(net, inputq);
301 	return rc;
302 }
303 
304 /* tipc_bcast_add_peer - add a peer node to broadcast link and bearer
305  *
306  * RCU is locked, node lock is set
307  */
308 void tipc_bcast_add_peer(struct net *net, struct tipc_link *uc_l,
309 			 struct sk_buff_head *xmitq)
310 {
311 	struct tipc_link *snd_l = tipc_bc_sndlink(net);
312 
313 	tipc_bcast_lock(net);
314 	tipc_link_add_bc_peer(snd_l, uc_l, xmitq);
315 	tipc_bcbase_select_primary(net);
316 	tipc_bcast_unlock(net);
317 }
318 
319 /* tipc_bcast_remove_peer - remove a peer node from broadcast link and bearer
320  *
321  * RCU is locked, node lock is set
322  */
323 void tipc_bcast_remove_peer(struct net *net, struct tipc_link *rcv_l)
324 {
325 	struct tipc_link *snd_l = tipc_bc_sndlink(net);
326 	struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
327 	struct sk_buff_head xmitq;
328 
329 	__skb_queue_head_init(&xmitq);
330 
331 	tipc_bcast_lock(net);
332 	tipc_link_remove_bc_peer(snd_l, rcv_l, &xmitq);
333 	tipc_bcbase_select_primary(net);
334 	tipc_bcast_unlock(net);
335 
336 	tipc_bcbase_xmit(net, &xmitq);
337 
338 	/* Any socket wakeup messages ? */
339 	if (!skb_queue_empty(inputq))
340 		tipc_sk_rcv(net, inputq);
341 }
342 
343 int tipc_bclink_reset_stats(struct net *net)
344 {
345 	struct tipc_link *l = tipc_bc_sndlink(net);
346 
347 	if (!l)
348 		return -ENOPROTOOPT;
349 
350 	tipc_bcast_lock(net);
351 	tipc_link_reset_stats(l);
352 	tipc_bcast_unlock(net);
353 	return 0;
354 }
355 
356 static int tipc_bc_link_set_queue_limits(struct net *net, u32 limit)
357 {
358 	struct tipc_link *l = tipc_bc_sndlink(net);
359 
360 	if (!l)
361 		return -ENOPROTOOPT;
362 	if (limit < BCLINK_WIN_MIN)
363 		limit = BCLINK_WIN_MIN;
364 	if (limit > TIPC_MAX_LINK_WIN)
365 		return -EINVAL;
366 	tipc_bcast_lock(net);
367 	tipc_link_set_queue_limits(l, limit);
368 	tipc_bcast_unlock(net);
369 	return 0;
370 }
371 
372 int tipc_nl_bc_link_set(struct net *net, struct nlattr *attrs[])
373 {
374 	int err;
375 	u32 win;
376 	struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
377 
378 	if (!attrs[TIPC_NLA_LINK_PROP])
379 		return -EINVAL;
380 
381 	err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP], props);
382 	if (err)
383 		return err;
384 
385 	if (!props[TIPC_NLA_PROP_WIN])
386 		return -EOPNOTSUPP;
387 
388 	win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
389 
390 	return tipc_bc_link_set_queue_limits(net, win);
391 }
392 
393 int tipc_bcast_init(struct net *net)
394 {
395 	struct tipc_net *tn = tipc_net(net);
396 	struct tipc_bc_base *bb = NULL;
397 	struct tipc_link *l = NULL;
398 
399 	bb = kzalloc(sizeof(*bb), GFP_ATOMIC);
400 	if (!bb)
401 		goto enomem;
402 	tn->bcbase = bb;
403 	spin_lock_init(&tipc_net(net)->bclock);
404 
405 	if (!tipc_link_bc_create(net, 0, 0,
406 				 U16_MAX,
407 				 BCLINK_WIN_DEFAULT,
408 				 0,
409 				 &bb->inputq,
410 				 NULL,
411 				 NULL,
412 				 &l))
413 		goto enomem;
414 	bb->link = l;
415 	tn->bcl = l;
416 	return 0;
417 enomem:
418 	kfree(bb);
419 	kfree(l);
420 	return -ENOMEM;
421 }
422 
423 void tipc_bcast_stop(struct net *net)
424 {
425 	struct tipc_net *tn = net_generic(net, tipc_net_id);
426 
427 	synchronize_net();
428 	kfree(tn->bcbase);
429 	kfree(tn->bcl);
430 }
431