dt-bindings: clock: rk3328: fixup HCLK_I2S1 id
[firefly-linux-kernel-4.4.55.git] / net / tipc / subscr.c
1 /*
2  * net/tipc/subscr.c: TIPC network topology service
3  *
4  * Copyright (c) 2000-2006, Ericsson AB
5  * Copyright (c) 2005-2007, 2010-2013, 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 "name_table.h"
39 #include "subscr.h"
40
41 /**
42  * struct tipc_subscriber - TIPC network topology subscriber
43  * @kref: reference counter to tipc_subscription object
44  * @conid: connection identifier to server connecting to subscriber
45  * @lock: control access to subscriber
46  * @subscrp_list: list of subscription objects for this subscriber
47  */
48 struct tipc_subscriber {
49         struct kref kref;
50         int conid;
51         spinlock_t lock;
52         struct list_head subscrp_list;
53 };
54
55 static void tipc_subscrp_delete(struct tipc_subscription *sub);
56 static void tipc_subscrb_put(struct tipc_subscriber *subscriber);
57
58 /**
59  * htohl - convert value to endianness used by destination
60  * @in: value to convert
61  * @swap: non-zero if endianness must be reversed
62  *
63  * Returns converted value
64  */
65 static u32 htohl(u32 in, int swap)
66 {
67         return swap ? swab32(in) : in;
68 }
69
70 static void tipc_subscrp_send_event(struct tipc_subscription *sub,
71                                     u32 found_lower, u32 found_upper,
72                                     u32 event, u32 port_ref, u32 node)
73 {
74         struct tipc_net *tn = net_generic(sub->net, tipc_net_id);
75         struct tipc_subscriber *subscriber = sub->subscriber;
76         struct kvec msg_sect;
77
78         msg_sect.iov_base = (void *)&sub->evt;
79         msg_sect.iov_len = sizeof(struct tipc_event);
80         sub->evt.event = htohl(event, sub->swap);
81         sub->evt.found_lower = htohl(found_lower, sub->swap);
82         sub->evt.found_upper = htohl(found_upper, sub->swap);
83         sub->evt.port.ref = htohl(port_ref, sub->swap);
84         sub->evt.port.node = htohl(node, sub->swap);
85         tipc_conn_sendmsg(tn->topsrv, subscriber->conid, NULL,
86                           msg_sect.iov_base, msg_sect.iov_len);
87 }
88
89 /**
90  * tipc_subscrp_check_overlap - test for subscription overlap with the
91  * given values
92  *
93  * Returns 1 if there is overlap, otherwise 0.
94  */
95 int tipc_subscrp_check_overlap(struct tipc_subscription *sub, u32 found_lower,
96                                u32 found_upper)
97 {
98         if (found_lower < sub->seq.lower)
99                 found_lower = sub->seq.lower;
100         if (found_upper > sub->seq.upper)
101                 found_upper = sub->seq.upper;
102         if (found_lower > found_upper)
103                 return 0;
104         return 1;
105 }
106
107 void tipc_subscrp_report_overlap(struct tipc_subscription *sub, u32 found_lower,
108                                  u32 found_upper, u32 event, u32 port_ref,
109                                  u32 node, int must)
110 {
111         if (!tipc_subscrp_check_overlap(sub, found_lower, found_upper))
112                 return;
113         if (!must && !(sub->filter & TIPC_SUB_PORTS))
114                 return;
115
116         tipc_subscrp_send_event(sub, found_lower, found_upper, event, port_ref,
117                                 node);
118 }
119
120 static void tipc_subscrp_timeout(unsigned long data)
121 {
122         struct tipc_subscription *sub = (struct tipc_subscription *)data;
123         struct tipc_subscriber *subscriber = sub->subscriber;
124
125         /* Notify subscriber of timeout */
126         tipc_subscrp_send_event(sub, sub->evt.s.seq.lower, sub->evt.s.seq.upper,
127                                 TIPC_SUBSCR_TIMEOUT, 0, 0);
128
129         spin_lock_bh(&subscriber->lock);
130         tipc_subscrp_delete(sub);
131         spin_unlock_bh(&subscriber->lock);
132
133         tipc_subscrb_put(subscriber);
134 }
135
136 static void tipc_subscrb_kref_release(struct kref *kref)
137 {
138         struct tipc_subscriber *subcriber = container_of(kref,
139                                             struct tipc_subscriber, kref);
140
141         kfree(subcriber);
142 }
143
144 static void tipc_subscrb_put(struct tipc_subscriber *subscriber)
145 {
146         kref_put(&subscriber->kref, tipc_subscrb_kref_release);
147 }
148
149 static void tipc_subscrb_get(struct tipc_subscriber *subscriber)
150 {
151         kref_get(&subscriber->kref);
152 }
153
154 static struct tipc_subscriber *tipc_subscrb_create(int conid)
155 {
156         struct tipc_subscriber *subscriber;
157
158         subscriber = kzalloc(sizeof(*subscriber), GFP_ATOMIC);
159         if (!subscriber) {
160                 pr_warn("Subscriber rejected, no memory\n");
161                 return NULL;
162         }
163         kref_init(&subscriber->kref);
164         INIT_LIST_HEAD(&subscriber->subscrp_list);
165         subscriber->conid = conid;
166         spin_lock_init(&subscriber->lock);
167
168         return subscriber;
169 }
170
171 static void tipc_subscrb_delete(struct tipc_subscriber *subscriber)
172 {
173         struct tipc_subscription *sub, *temp;
174
175         spin_lock_bh(&subscriber->lock);
176         /* Destroy any existing subscriptions for subscriber */
177         list_for_each_entry_safe(sub, temp, &subscriber->subscrp_list,
178                                  subscrp_list) {
179                 if (del_timer(&sub->timer)) {
180                         tipc_subscrp_delete(sub);
181                         tipc_subscrb_put(subscriber);
182                 }
183         }
184         spin_unlock_bh(&subscriber->lock);
185
186         tipc_subscrb_put(subscriber);
187 }
188
189 static void tipc_subscrp_delete(struct tipc_subscription *sub)
190 {
191         struct tipc_net *tn = net_generic(sub->net, tipc_net_id);
192
193         tipc_nametbl_unsubscribe(sub);
194         list_del(&sub->subscrp_list);
195         kfree(sub);
196         atomic_dec(&tn->subscription_count);
197 }
198
199 static void tipc_subscrp_cancel(struct tipc_subscr *s,
200                                 struct tipc_subscriber *subscriber)
201 {
202         struct tipc_subscription *sub, *temp;
203
204         spin_lock_bh(&subscriber->lock);
205         /* Find first matching subscription, exit if not found */
206         list_for_each_entry_safe(sub, temp, &subscriber->subscrp_list,
207                                  subscrp_list) {
208                 if (!memcmp(s, &sub->evt.s, sizeof(struct tipc_subscr))) {
209                         if (del_timer(&sub->timer)) {
210                                 tipc_subscrp_delete(sub);
211                                 tipc_subscrb_put(subscriber);
212                         }
213                         break;
214                 }
215         }
216         spin_unlock_bh(&subscriber->lock);
217 }
218
219 static int tipc_subscrp_create(struct net *net, struct tipc_subscr *s,
220                                struct tipc_subscriber *subscriber,
221                                struct tipc_subscription **sub_p)
222 {
223         struct tipc_net *tn = net_generic(net, tipc_net_id);
224         struct tipc_subscription *sub;
225         int swap;
226
227         /* Determine subscriber's endianness */
228         swap = !(s->filter & (TIPC_SUB_PORTS | TIPC_SUB_SERVICE));
229
230         /* Detect & process a subscription cancellation request */
231         if (s->filter & htohl(TIPC_SUB_CANCEL, swap)) {
232                 s->filter &= ~htohl(TIPC_SUB_CANCEL, swap);
233                 tipc_subscrp_cancel(s, subscriber);
234                 return 0;
235         }
236
237         /* Refuse subscription if global limit exceeded */
238         if (atomic_read(&tn->subscription_count) >= TIPC_MAX_SUBSCRIPTIONS) {
239                 pr_warn("Subscription rejected, limit reached (%u)\n",
240                         TIPC_MAX_SUBSCRIPTIONS);
241                 return -EINVAL;
242         }
243
244         /* Allocate subscription object */
245         sub = kmalloc(sizeof(*sub), GFP_ATOMIC);
246         if (!sub) {
247                 pr_warn("Subscription rejected, no memory\n");
248                 return -ENOMEM;
249         }
250
251         /* Initialize subscription object */
252         sub->net = net;
253         sub->seq.type = htohl(s->seq.type, swap);
254         sub->seq.lower = htohl(s->seq.lower, swap);
255         sub->seq.upper = htohl(s->seq.upper, swap);
256         sub->timeout = msecs_to_jiffies(htohl(s->timeout, swap));
257         sub->filter = htohl(s->filter, swap);
258         if ((!(sub->filter & TIPC_SUB_PORTS) ==
259              !(sub->filter & TIPC_SUB_SERVICE)) ||
260             (sub->seq.lower > sub->seq.upper)) {
261                 pr_warn("Subscription rejected, illegal request\n");
262                 kfree(sub);
263                 return -EINVAL;
264         }
265         spin_lock_bh(&subscriber->lock);
266         list_add(&sub->subscrp_list, &subscriber->subscrp_list);
267         spin_unlock_bh(&subscriber->lock);
268         sub->subscriber = subscriber;
269         sub->swap = swap;
270         memcpy(&sub->evt.s, s, sizeof(*s));
271         atomic_inc(&tn->subscription_count);
272         setup_timer(&sub->timer, tipc_subscrp_timeout, (unsigned long)sub);
273         if (sub->timeout != TIPC_WAIT_FOREVER)
274                 sub->timeout += jiffies;
275         if (!mod_timer(&sub->timer, sub->timeout))
276                 tipc_subscrb_get(subscriber);
277         *sub_p = sub;
278         return 0;
279 }
280
281 /* Handle one termination request for the subscriber */
282 static void tipc_subscrb_shutdown_cb(int conid, void *usr_data)
283 {
284         tipc_subscrb_delete((struct tipc_subscriber *)usr_data);
285 }
286
287 /* Handle one request to create a new subscription for the subscriber */
288 static void tipc_subscrb_rcv_cb(struct net *net, int conid,
289                                 struct sockaddr_tipc *addr, void *usr_data,
290                                 void *buf, size_t len)
291 {
292         struct tipc_subscriber *subscrb = usr_data;
293         struct tipc_subscription *sub = NULL;
294         struct tipc_net *tn = net_generic(net, tipc_net_id);
295
296         if (tipc_subscrp_create(net, (struct tipc_subscr *)buf, subscrb, &sub))
297                 return tipc_conn_terminate(tn->topsrv, subscrb->conid);
298
299         if (sub)
300                 tipc_nametbl_subscribe(sub);
301 }
302
303 /* Handle one request to establish a new subscriber */
304 static void *tipc_subscrb_connect_cb(int conid)
305 {
306         return (void *)tipc_subscrb_create(conid);
307 }
308
309 int tipc_topsrv_start(struct net *net)
310 {
311         struct tipc_net *tn = net_generic(net, tipc_net_id);
312         const char name[] = "topology_server";
313         struct tipc_server *topsrv;
314         struct sockaddr_tipc *saddr;
315
316         saddr = kzalloc(sizeof(*saddr), GFP_ATOMIC);
317         if (!saddr)
318                 return -ENOMEM;
319         saddr->family                   = AF_TIPC;
320         saddr->addrtype                 = TIPC_ADDR_NAMESEQ;
321         saddr->addr.nameseq.type        = TIPC_TOP_SRV;
322         saddr->addr.nameseq.lower       = TIPC_TOP_SRV;
323         saddr->addr.nameseq.upper       = TIPC_TOP_SRV;
324         saddr->scope                    = TIPC_NODE_SCOPE;
325
326         topsrv = kzalloc(sizeof(*topsrv), GFP_ATOMIC);
327         if (!topsrv) {
328                 kfree(saddr);
329                 return -ENOMEM;
330         }
331         topsrv->net                     = net;
332         topsrv->saddr                   = saddr;
333         topsrv->imp                     = TIPC_CRITICAL_IMPORTANCE;
334         topsrv->type                    = SOCK_SEQPACKET;
335         topsrv->max_rcvbuf_size         = sizeof(struct tipc_subscr);
336         topsrv->tipc_conn_recvmsg       = tipc_subscrb_rcv_cb;
337         topsrv->tipc_conn_new           = tipc_subscrb_connect_cb;
338         topsrv->tipc_conn_shutdown      = tipc_subscrb_shutdown_cb;
339
340         strncpy(topsrv->name, name, strlen(name) + 1);
341         tn->topsrv = topsrv;
342         atomic_set(&tn->subscription_count, 0);
343
344         return tipc_server_start(topsrv);
345 }
346
347 void tipc_topsrv_stop(struct net *net)
348 {
349         struct tipc_net *tn = net_generic(net, tipc_net_id);
350         struct tipc_server *topsrv = tn->topsrv;
351
352         tipc_server_stop(topsrv);
353         kfree(topsrv->saddr);
354         kfree(topsrv);
355 }