xref: /openbmc/linux/net/tipc/name_distr.c (revision 2208f39c)
1 /*
2  * net/tipc/name_distr.c: TIPC name distribution code
3  *
4  * Copyright (c) 2000-2006, 2014, Ericsson AB
5  * Copyright (c) 2005, 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 "link.h"
39 #include "name_distr.h"
40 
41 int sysctl_tipc_named_timeout __read_mostly = 2000;
42 
43 struct distr_queue_item {
44 	struct distr_item i;
45 	u32 dtype;
46 	u32 node;
47 	unsigned long expires;
48 	struct list_head next;
49 };
50 
51 /**
52  * publ_to_item - add publication info to a publication message
53  */
54 static void publ_to_item(struct distr_item *i, struct publication *p)
55 {
56 	i->type = htonl(p->type);
57 	i->lower = htonl(p->lower);
58 	i->upper = htonl(p->upper);
59 	i->port = htonl(p->port);
60 	i->key = htonl(p->key);
61 }
62 
63 /**
64  * named_prepare_buf - allocate & initialize a publication message
65  *
66  * The buffer returned is of size INT_H_SIZE + payload size
67  */
68 static struct sk_buff *named_prepare_buf(struct net *net, u32 type, u32 size,
69 					 u32 dest)
70 {
71 	struct sk_buff *buf = tipc_buf_acquire(INT_H_SIZE + size, GFP_ATOMIC);
72 	u32 self = tipc_own_addr(net);
73 	struct tipc_msg *msg;
74 
75 	if (buf != NULL) {
76 		msg = buf_msg(buf);
77 		tipc_msg_init(self, msg, NAME_DISTRIBUTOR,
78 			      type, INT_H_SIZE, dest);
79 		msg_set_size(msg, INT_H_SIZE + size);
80 	}
81 	return buf;
82 }
83 
84 /**
85  * tipc_named_publish - tell other nodes about a new publication by this node
86  */
87 struct sk_buff *tipc_named_publish(struct net *net, struct publication *publ)
88 {
89 	struct name_table *nt = tipc_name_table(net);
90 	struct distr_item *item;
91 	struct sk_buff *skb;
92 
93 	if (publ->scope == TIPC_NODE_SCOPE) {
94 		list_add_tail_rcu(&publ->binding_node, &nt->node_scope);
95 		return NULL;
96 	}
97 	write_lock_bh(&nt->cluster_scope_lock);
98 	list_add_tail(&publ->binding_node, &nt->cluster_scope);
99 	write_unlock_bh(&nt->cluster_scope_lock);
100 	skb = named_prepare_buf(net, PUBLICATION, ITEM_SIZE, 0);
101 	if (!skb) {
102 		pr_warn("Publication distribution failure\n");
103 		return NULL;
104 	}
105 	msg_set_named_seqno(buf_msg(skb), nt->snd_nxt++);
106 	msg_set_non_legacy(buf_msg(skb));
107 	item = (struct distr_item *)msg_data(buf_msg(skb));
108 	publ_to_item(item, publ);
109 	return skb;
110 }
111 
112 /**
113  * tipc_named_withdraw - tell other nodes about a withdrawn publication by this node
114  */
115 struct sk_buff *tipc_named_withdraw(struct net *net, struct publication *publ)
116 {
117 	struct name_table *nt = tipc_name_table(net);
118 	struct distr_item *item;
119 	struct sk_buff *skb;
120 
121 	write_lock_bh(&nt->cluster_scope_lock);
122 	list_del(&publ->binding_node);
123 	write_unlock_bh(&nt->cluster_scope_lock);
124 	if (publ->scope == TIPC_NODE_SCOPE)
125 		return NULL;
126 
127 	skb = named_prepare_buf(net, WITHDRAWAL, ITEM_SIZE, 0);
128 	if (!skb) {
129 		pr_warn("Withdrawal distribution failure\n");
130 		return NULL;
131 	}
132 	msg_set_named_seqno(buf_msg(skb), nt->snd_nxt++);
133 	msg_set_non_legacy(buf_msg(skb));
134 	item = (struct distr_item *)msg_data(buf_msg(skb));
135 	publ_to_item(item, publ);
136 	return skb;
137 }
138 
139 /**
140  * named_distribute - prepare name info for bulk distribution to another node
141  * @list: list of messages (buffers) to be returned from this function
142  * @dnode: node to be updated
143  * @pls: linked list of publication items to be packed into buffer chain
144  */
145 static void named_distribute(struct net *net, struct sk_buff_head *list,
146 			     u32 dnode, struct list_head *pls, u16 seqno)
147 {
148 	struct publication *publ;
149 	struct sk_buff *skb = NULL;
150 	struct distr_item *item = NULL;
151 	u32 msg_dsz = ((tipc_node_get_mtu(net, dnode, 0, false) - INT_H_SIZE) /
152 			ITEM_SIZE) * ITEM_SIZE;
153 	u32 msg_rem = msg_dsz;
154 	struct tipc_msg *hdr;
155 
156 	list_for_each_entry(publ, pls, binding_node) {
157 		/* Prepare next buffer: */
158 		if (!skb) {
159 			skb = named_prepare_buf(net, PUBLICATION, msg_rem,
160 						dnode);
161 			if (!skb) {
162 				pr_warn("Bulk publication failure\n");
163 				return;
164 			}
165 			hdr = buf_msg(skb);
166 			msg_set_bc_ack_invalid(hdr, true);
167 			msg_set_bulk(hdr);
168 			msg_set_non_legacy(hdr);
169 			item = (struct distr_item *)msg_data(hdr);
170 		}
171 
172 		/* Pack publication into message: */
173 		publ_to_item(item, publ);
174 		item++;
175 		msg_rem -= ITEM_SIZE;
176 
177 		/* Append full buffer to list: */
178 		if (!msg_rem) {
179 			__skb_queue_tail(list, skb);
180 			skb = NULL;
181 			msg_rem = msg_dsz;
182 		}
183 	}
184 	if (skb) {
185 		hdr = buf_msg(skb);
186 		msg_set_size(hdr, INT_H_SIZE + (msg_dsz - msg_rem));
187 		skb_trim(skb, INT_H_SIZE + (msg_dsz - msg_rem));
188 		__skb_queue_tail(list, skb);
189 	}
190 	hdr = buf_msg(skb_peek_tail(list));
191 	msg_set_last_bulk(hdr);
192 	msg_set_named_seqno(hdr, seqno);
193 }
194 
195 /**
196  * tipc_named_node_up - tell specified node about all publications by this node
197  */
198 void tipc_named_node_up(struct net *net, u32 dnode, u16 capabilities)
199 {
200 	struct name_table *nt = tipc_name_table(net);
201 	struct tipc_net *tn = tipc_net(net);
202 	struct sk_buff_head head;
203 	u16 seqno;
204 
205 	__skb_queue_head_init(&head);
206 	spin_lock_bh(&tn->nametbl_lock);
207 	if (!(capabilities & TIPC_NAMED_BCAST))
208 		nt->rc_dests++;
209 	seqno = nt->snd_nxt;
210 	spin_unlock_bh(&tn->nametbl_lock);
211 
212 	read_lock_bh(&nt->cluster_scope_lock);
213 	named_distribute(net, &head, dnode, &nt->cluster_scope, seqno);
214 	tipc_node_xmit(net, &head, dnode, 0);
215 	read_unlock_bh(&nt->cluster_scope_lock);
216 }
217 
218 /**
219  * tipc_publ_purge - remove publication associated with a failed node
220  *
221  * Invoked for each publication issued by a newly failed node.
222  * Removes publication structure from name table & deletes it.
223  */
224 static void tipc_publ_purge(struct net *net, struct publication *publ, u32 addr)
225 {
226 	struct tipc_net *tn = tipc_net(net);
227 	struct publication *p;
228 
229 	spin_lock_bh(&tn->nametbl_lock);
230 	p = tipc_nametbl_remove_publ(net, publ->type, publ->lower, publ->upper,
231 				     publ->node, publ->key);
232 	if (p)
233 		tipc_node_unsubscribe(net, &p->binding_node, addr);
234 	spin_unlock_bh(&tn->nametbl_lock);
235 
236 	if (p != publ) {
237 		pr_err("Unable to remove publication from failed node\n"
238 		       " (type=%u, lower=%u, node=0x%x, port=%u, key=%u)\n",
239 		       publ->type, publ->lower, publ->node, publ->port,
240 		       publ->key);
241 	}
242 
243 	if (p)
244 		kfree_rcu(p, rcu);
245 }
246 
247 /**
248  * tipc_dist_queue_purge - remove deferred updates from a node that went down
249  */
250 static void tipc_dist_queue_purge(struct net *net, u32 addr)
251 {
252 	struct tipc_net *tn = net_generic(net, tipc_net_id);
253 	struct distr_queue_item *e, *tmp;
254 
255 	spin_lock_bh(&tn->nametbl_lock);
256 	list_for_each_entry_safe(e, tmp, &tn->dist_queue, next) {
257 		if (e->node != addr)
258 			continue;
259 		list_del(&e->next);
260 		kfree(e);
261 	}
262 	spin_unlock_bh(&tn->nametbl_lock);
263 }
264 
265 void tipc_publ_notify(struct net *net, struct list_head *nsub_list,
266 		      u32 addr, u16 capabilities)
267 {
268 	struct name_table *nt = tipc_name_table(net);
269 	struct tipc_net *tn = tipc_net(net);
270 
271 	struct publication *publ, *tmp;
272 
273 	list_for_each_entry_safe(publ, tmp, nsub_list, binding_node)
274 		tipc_publ_purge(net, publ, addr);
275 	tipc_dist_queue_purge(net, addr);
276 	spin_lock_bh(&tn->nametbl_lock);
277 	if (!(capabilities & TIPC_NAMED_BCAST))
278 		nt->rc_dests--;
279 	spin_unlock_bh(&tn->nametbl_lock);
280 }
281 
282 /**
283  * tipc_update_nametbl - try to process a nametable update and notify
284  *			 subscribers
285  *
286  * tipc_nametbl_lock must be held.
287  * Returns the publication item if successful, otherwise NULL.
288  */
289 static bool tipc_update_nametbl(struct net *net, struct distr_item *i,
290 				u32 node, u32 dtype)
291 {
292 	struct publication *p = NULL;
293 	u32 lower = ntohl(i->lower);
294 	u32 upper = ntohl(i->upper);
295 	u32 type = ntohl(i->type);
296 	u32 port = ntohl(i->port);
297 	u32 key = ntohl(i->key);
298 
299 	if (dtype == PUBLICATION) {
300 		p = tipc_nametbl_insert_publ(net, type, lower, upper,
301 					     TIPC_CLUSTER_SCOPE, node,
302 					     port, key);
303 		if (p) {
304 			tipc_node_subscribe(net, &p->binding_node, node);
305 			return true;
306 		}
307 	} else if (dtype == WITHDRAWAL) {
308 		p = tipc_nametbl_remove_publ(net, type, lower,
309 					     upper, node, key);
310 		if (p) {
311 			tipc_node_unsubscribe(net, &p->binding_node, node);
312 			kfree_rcu(p, rcu);
313 			return true;
314 		}
315 		pr_warn_ratelimited("Failed to remove binding %u,%u from %x\n",
316 				    type, lower, node);
317 	} else {
318 		pr_warn("Unrecognized name table message received\n");
319 	}
320 	return false;
321 }
322 
323 static struct sk_buff *tipc_named_dequeue(struct sk_buff_head *namedq,
324 					  u16 *rcv_nxt, bool *open)
325 {
326 	struct sk_buff *skb, *tmp;
327 	struct tipc_msg *hdr;
328 	u16 seqno;
329 
330 	spin_lock_bh(&namedq->lock);
331 	skb_queue_walk_safe(namedq, skb, tmp) {
332 		if (unlikely(skb_linearize(skb))) {
333 			__skb_unlink(skb, namedq);
334 			kfree_skb(skb);
335 			continue;
336 		}
337 		hdr = buf_msg(skb);
338 		seqno = msg_named_seqno(hdr);
339 		if (msg_is_last_bulk(hdr)) {
340 			*rcv_nxt = seqno;
341 			*open = true;
342 		}
343 
344 		if (msg_is_bulk(hdr) || msg_is_legacy(hdr)) {
345 			__skb_unlink(skb, namedq);
346 			spin_unlock_bh(&namedq->lock);
347 			return skb;
348 		}
349 
350 		if (*open && (*rcv_nxt == seqno)) {
351 			(*rcv_nxt)++;
352 			__skb_unlink(skb, namedq);
353 			spin_unlock_bh(&namedq->lock);
354 			return skb;
355 		}
356 
357 		if (less(seqno, *rcv_nxt)) {
358 			__skb_unlink(skb, namedq);
359 			kfree_skb(skb);
360 			continue;
361 		}
362 	}
363 	spin_unlock_bh(&namedq->lock);
364 	return NULL;
365 }
366 
367 /**
368  * tipc_named_rcv - process name table update messages sent by another node
369  */
370 void tipc_named_rcv(struct net *net, struct sk_buff_head *namedq,
371 		    u16 *rcv_nxt, bool *open)
372 {
373 	struct tipc_net *tn = tipc_net(net);
374 	struct distr_item *item;
375 	struct tipc_msg *hdr;
376 	struct sk_buff *skb;
377 	u32 count, node;
378 
379 	spin_lock_bh(&tn->nametbl_lock);
380 	while ((skb = tipc_named_dequeue(namedq, rcv_nxt, open))) {
381 		hdr = buf_msg(skb);
382 		node = msg_orignode(hdr);
383 		item = (struct distr_item *)msg_data(hdr);
384 		count = msg_data_sz(hdr) / ITEM_SIZE;
385 		while (count--) {
386 			tipc_update_nametbl(net, item, node, msg_type(hdr));
387 			item++;
388 		}
389 		kfree_skb(skb);
390 	}
391 	spin_unlock_bh(&tn->nametbl_lock);
392 }
393 
394 /**
395  * tipc_named_reinit - re-initialize local publications
396  *
397  * This routine is called whenever TIPC networking is enabled.
398  * All name table entries published by this node are updated to reflect
399  * the node's new network address.
400  */
401 void tipc_named_reinit(struct net *net)
402 {
403 	struct name_table *nt = tipc_name_table(net);
404 	struct tipc_net *tn = tipc_net(net);
405 	struct publication *publ;
406 	u32 self = tipc_own_addr(net);
407 
408 	spin_lock_bh(&tn->nametbl_lock);
409 
410 	list_for_each_entry_rcu(publ, &nt->node_scope, binding_node)
411 		publ->node = self;
412 	list_for_each_entry_rcu(publ, &nt->cluster_scope, binding_node)
413 		publ->node = self;
414 	nt->rc_dests = 0;
415 	spin_unlock_bh(&tn->nametbl_lock);
416 }
417