xref: /openbmc/linux/net/tipc/bcast.c (revision fa7f32422ea1ac276b45b96a540ed5981caaa61f)
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, u32 acked)
251 {
252 	struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
253 	struct sk_buff_head xmitq;
254 
255 	__skb_queue_head_init(&xmitq);
256 
257 	tipc_bcast_lock(net);
258 	tipc_link_bc_ack_rcv(l, acked, &xmitq);
259 	tipc_bcast_unlock(net);
260 
261 	tipc_bcbase_xmit(net, &xmitq);
262 
263 	/* Any socket wakeup messages ? */
264 	if (!skb_queue_empty(inputq))
265 		tipc_sk_rcv(net, inputq);
266 }
267 
268 /* tipc_bcast_synch_rcv -  check and update rcv link with peer's send state
269  *
270  * RCU is locked, no other locks set
271  */
272 int tipc_bcast_sync_rcv(struct net *net, struct tipc_link *l,
273 			struct tipc_msg *hdr)
274 {
275 	struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
276 	struct sk_buff_head xmitq;
277 	int rc = 0;
278 
279 	__skb_queue_head_init(&xmitq);
280 
281 	tipc_bcast_lock(net);
282 	if (msg_type(hdr) == STATE_MSG) {
283 		tipc_link_bc_ack_rcv(l, msg_bcast_ack(hdr), &xmitq);
284 		rc = tipc_link_bc_sync_rcv(l, hdr, &xmitq);
285 	} else {
286 		tipc_link_bc_init_rcv(l, hdr);
287 	}
288 	tipc_bcast_unlock(net);
289 
290 	tipc_bcbase_xmit(net, &xmitq);
291 
292 	/* Any socket wakeup messages ? */
293 	if (!skb_queue_empty(inputq))
294 		tipc_sk_rcv(net, inputq);
295 	return rc;
296 }
297 
298 /* tipc_bcast_add_peer - add a peer node to broadcast link and bearer
299  *
300  * RCU is locked, node lock is set
301  */
302 void tipc_bcast_add_peer(struct net *net, struct tipc_link *uc_l,
303 			 struct sk_buff_head *xmitq)
304 {
305 	struct tipc_link *snd_l = tipc_bc_sndlink(net);
306 
307 	tipc_bcast_lock(net);
308 	tipc_link_add_bc_peer(snd_l, uc_l, xmitq);
309 	tipc_bcbase_select_primary(net);
310 	tipc_bcast_unlock(net);
311 }
312 
313 /* tipc_bcast_remove_peer - remove a peer node from broadcast link and bearer
314  *
315  * RCU is locked, node lock is set
316  */
317 void tipc_bcast_remove_peer(struct net *net, struct tipc_link *rcv_l)
318 {
319 	struct tipc_link *snd_l = tipc_bc_sndlink(net);
320 	struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
321 	struct sk_buff_head xmitq;
322 
323 	__skb_queue_head_init(&xmitq);
324 
325 	tipc_bcast_lock(net);
326 	tipc_link_remove_bc_peer(snd_l, rcv_l, &xmitq);
327 	tipc_bcbase_select_primary(net);
328 	tipc_bcast_unlock(net);
329 
330 	tipc_bcbase_xmit(net, &xmitq);
331 
332 	/* Any socket wakeup messages ? */
333 	if (!skb_queue_empty(inputq))
334 		tipc_sk_rcv(net, inputq);
335 }
336 
337 int tipc_bclink_reset_stats(struct net *net)
338 {
339 	struct tipc_link *l = tipc_bc_sndlink(net);
340 
341 	if (!l)
342 		return -ENOPROTOOPT;
343 
344 	tipc_bcast_lock(net);
345 	tipc_link_reset_stats(l);
346 	tipc_bcast_unlock(net);
347 	return 0;
348 }
349 
350 static int tipc_bc_link_set_queue_limits(struct net *net, u32 limit)
351 {
352 	struct tipc_link *l = tipc_bc_sndlink(net);
353 
354 	if (!l)
355 		return -ENOPROTOOPT;
356 	if (limit < BCLINK_WIN_MIN)
357 		limit = BCLINK_WIN_MIN;
358 	if (limit > TIPC_MAX_LINK_WIN)
359 		return -EINVAL;
360 	tipc_bcast_lock(net);
361 	tipc_link_set_queue_limits(l, limit);
362 	tipc_bcast_unlock(net);
363 	return 0;
364 }
365 
366 int tipc_nl_bc_link_set(struct net *net, struct nlattr *attrs[])
367 {
368 	int err;
369 	u32 win;
370 	struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
371 
372 	if (!attrs[TIPC_NLA_LINK_PROP])
373 		return -EINVAL;
374 
375 	err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP], props);
376 	if (err)
377 		return err;
378 
379 	if (!props[TIPC_NLA_PROP_WIN])
380 		return -EOPNOTSUPP;
381 
382 	win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
383 
384 	return tipc_bc_link_set_queue_limits(net, win);
385 }
386 
387 int tipc_bcast_init(struct net *net)
388 {
389 	struct tipc_net *tn = tipc_net(net);
390 	struct tipc_bc_base *bb = NULL;
391 	struct tipc_link *l = NULL;
392 
393 	bb = kzalloc(sizeof(*bb), GFP_ATOMIC);
394 	if (!bb)
395 		goto enomem;
396 	tn->bcbase = bb;
397 	spin_lock_init(&tipc_net(net)->bclock);
398 
399 	if (!tipc_link_bc_create(net, 0, 0,
400 				 U16_MAX,
401 				 BCLINK_WIN_DEFAULT,
402 				 0,
403 				 &bb->inputq,
404 				 NULL,
405 				 NULL,
406 				 &l))
407 		goto enomem;
408 	bb->link = l;
409 	tn->bcl = l;
410 	return 0;
411 enomem:
412 	kfree(bb);
413 	kfree(l);
414 	return -ENOMEM;
415 }
416 
417 void tipc_bcast_stop(struct net *net)
418 {
419 	struct tipc_net *tn = net_generic(net, tipc_net_id);
420 
421 	synchronize_net();
422 	kfree(tn->bcbase);
423 	kfree(tn->bcl);
424 }
425