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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 "port.h"
40#include "subscr.h"
41
42/**
43 * struct tipc_subscriber - TIPC network topology subscriber
44 * @conid: connection identifier to server connecting to subscriber
45 * @lock: control access to subscriber
46 * @subscription_list: list of subscription objects for this subscriber
47 */
48struct tipc_subscriber {
49 int conid;
50 spinlock_t lock;
51 struct list_head subscription_list;
52};
53
54static void subscr_conn_msg_event(int conid, struct sockaddr_tipc *addr,
55 void *usr_data, void *buf, size_t len);
56static void *subscr_named_msg_event(int conid);
57static void subscr_conn_shutdown_event(int conid, void *usr_data);
58
59static atomic_t subscription_count = ATOMIC_INIT(0);
60
61static struct sockaddr_tipc topsrv_addr __read_mostly = {
62 .family = AF_TIPC,
63 .addrtype = TIPC_ADDR_NAMESEQ,
64 .addr.nameseq.type = TIPC_TOP_SRV,
65 .addr.nameseq.lower = TIPC_TOP_SRV,
66 .addr.nameseq.upper = TIPC_TOP_SRV,
67 .scope = TIPC_NODE_SCOPE
68};
69
70static struct tipc_server topsrv __read_mostly = {
71 .saddr = &topsrv_addr,
72 .imp = TIPC_CRITICAL_IMPORTANCE,
73 .type = SOCK_SEQPACKET,
74 .max_rcvbuf_size = sizeof(struct tipc_subscr),
75 .name = "topology_server",
76 .tipc_conn_recvmsg = subscr_conn_msg_event,
77 .tipc_conn_new = subscr_named_msg_event,
78 .tipc_conn_shutdown = subscr_conn_shutdown_event,
79};
80
81/**
82 * htohl - convert value to endianness used by destination
83 * @in: value to convert
84 * @swap: non-zero if endianness must be reversed
85 *
86 * Returns converted value
87 */
88static u32 htohl(u32 in, int swap)
89{
90 return swap ? swab32(in) : in;
91}
92
93static void subscr_send_event(struct tipc_subscription *sub, u32 found_lower,
94 u32 found_upper, u32 event, u32 port_ref,
95 u32 node)
96{
97 struct tipc_subscriber *subscriber = sub->subscriber;
98 struct kvec msg_sect;
99
100 msg_sect.iov_base = (void *)&sub->evt;
101 msg_sect.iov_len = sizeof(struct tipc_event);
102 sub->evt.event = htohl(event, sub->swap);
103 sub->evt.found_lower = htohl(found_lower, sub->swap);
104 sub->evt.found_upper = htohl(found_upper, sub->swap);
105 sub->evt.port.ref = htohl(port_ref, sub->swap);
106 sub->evt.port.node = htohl(node, sub->swap);
107 tipc_conn_sendmsg(&topsrv, subscriber->conid, NULL, msg_sect.iov_base,
108 msg_sect.iov_len);
109}
110
111/**
112 * tipc_subscr_overlap - test for subscription overlap with the given values
113 *
114 * Returns 1 if there is overlap, otherwise 0.
115 */
116int tipc_subscr_overlap(struct tipc_subscription *sub, u32 found_lower,
117 u32 found_upper)
118{
119 if (found_lower < sub->seq.lower)
120 found_lower = sub->seq.lower;
121 if (found_upper > sub->seq.upper)
122 found_upper = sub->seq.upper;
123 if (found_lower > found_upper)
124 return 0;
125 return 1;
126}
127
128/**
129 * tipc_subscr_report_overlap - issue event if there is subscription overlap
130 *
131 * Protected by nameseq.lock in name_table.c
132 */
133void tipc_subscr_report_overlap(struct tipc_subscription *sub, u32 found_lower,
134 u32 found_upper, u32 event, u32 port_ref,
135 u32 node, int must)
136{
137 if (!tipc_subscr_overlap(sub, found_lower, found_upper))
138 return;
139 if (!must && !(sub->filter & TIPC_SUB_PORTS))
140 return;
141
142 subscr_send_event(sub, found_lower, found_upper, event, port_ref, node);
143}
144
145static void subscr_timeout(struct tipc_subscription *sub)
146{
147 struct tipc_subscriber *subscriber = sub->subscriber;
148
149 /* The spin lock per subscriber is used to protect its members */
150 spin_lock_bh(&subscriber->lock);
151
152 /* Validate timeout (in case subscription is being cancelled) */
153 if (sub->timeout == TIPC_WAIT_FOREVER) {
154 spin_unlock_bh(&subscriber->lock);
155 return;
156 }
157
158 /* Unlink subscription from name table */
159 tipc_nametbl_unsubscribe(sub);
160
161 /* Unlink subscription from subscriber */
162 list_del(&sub->subscription_list);
163
164 spin_unlock_bh(&subscriber->lock);
165
166 /* Notify subscriber of timeout */
167 subscr_send_event(sub, sub->evt.s.seq.lower, sub->evt.s.seq.upper,
168 TIPC_SUBSCR_TIMEOUT, 0, 0);
169
170 /* Now destroy subscription */
171 k_term_timer(&sub->timer);
172 kfree(sub);
173 atomic_dec(&subscription_count);
174}
175
176/**
177 * subscr_del - delete a subscription within a subscription list
178 *
179 * Called with subscriber lock held.
180 */
181static void subscr_del(struct tipc_subscription *sub)
182{
183 tipc_nametbl_unsubscribe(sub);
184 list_del(&sub->subscription_list);
185 kfree(sub);
186 atomic_dec(&subscription_count);
187}
188
189/**
190 * subscr_terminate - terminate communication with a subscriber
191 *
192 * Note: Must call it in process context since it might sleep.
193 */
194static void subscr_terminate(struct tipc_subscriber *subscriber)
195{
196 tipc_conn_terminate(&topsrv, subscriber->conid);
197}
198
199static void subscr_release(struct tipc_subscriber *subscriber)
200{
201 struct tipc_subscription *sub;
202 struct tipc_subscription *sub_temp;
203
204 spin_lock_bh(&subscriber->lock);
205
206 /* Destroy any existing subscriptions for subscriber */
207 list_for_each_entry_safe(sub, sub_temp, &subscriber->subscription_list,
208 subscription_list) {
209 if (sub->timeout != TIPC_WAIT_FOREVER) {
210 spin_unlock_bh(&subscriber->lock);
211 k_cancel_timer(&sub->timer);
212 k_term_timer(&sub->timer);
213 spin_lock_bh(&subscriber->lock);
214 }
215 subscr_del(sub);
216 }
217 spin_unlock_bh(&subscriber->lock);
218
219 /* Now destroy subscriber */
220 kfree(subscriber);
221}
222
223/**
224 * subscr_cancel - handle subscription cancellation request
225 *
226 * Called with subscriber lock held. Routine must temporarily release lock
227 * to enable the subscription timeout routine to finish without deadlocking;
228 * the lock is then reclaimed to allow caller to release it upon return.
229 *
230 * Note that fields of 's' use subscriber's endianness!
231 */
232static void subscr_cancel(struct tipc_subscr *s,
233 struct tipc_subscriber *subscriber)
234{
235 struct tipc_subscription *sub;
236 struct tipc_subscription *sub_temp;
237 int found = 0;
238
239 /* Find first matching subscription, exit if not found */
240 list_for_each_entry_safe(sub, sub_temp, &subscriber->subscription_list,
241 subscription_list) {
242 if (!memcmp(s, &sub->evt.s, sizeof(struct tipc_subscr))) {
243 found = 1;
244 break;
245 }
246 }
247 if (!found)
248 return;
249
250 /* Cancel subscription timer (if used), then delete subscription */
251 if (sub->timeout != TIPC_WAIT_FOREVER) {
252 sub->timeout = TIPC_WAIT_FOREVER;
253 spin_unlock_bh(&subscriber->lock);
254 k_cancel_timer(&sub->timer);
255 k_term_timer(&sub->timer);
256 spin_lock_bh(&subscriber->lock);
257 }
258 subscr_del(sub);
259}
260
261/**
262 * subscr_subscribe - create subscription for subscriber
263 *
264 * Called with subscriber lock held.
265 */
266static int subscr_subscribe(struct tipc_subscr *s,
267 struct tipc_subscriber *subscriber,
268 struct tipc_subscription **sub_p) {
269 struct tipc_subscription *sub;
270 int swap;
271
272 /* Determine subscriber's endianness */
273 swap = !(s->filter & (TIPC_SUB_PORTS | TIPC_SUB_SERVICE));
274
275 /* Detect & process a subscription cancellation request */
276 if (s->filter & htohl(TIPC_SUB_CANCEL, swap)) {
277 s->filter &= ~htohl(TIPC_SUB_CANCEL, swap);
278 subscr_cancel(s, subscriber);
279 return 0;
280 }
281
282 /* Refuse subscription if global limit exceeded */
283 if (atomic_read(&subscription_count) >= TIPC_MAX_SUBSCRIPTIONS) {
284 pr_warn("Subscription rejected, limit reached (%u)\n",
285 TIPC_MAX_SUBSCRIPTIONS);
286 return -EINVAL;
287 }
288
289 /* Allocate subscription object */
290 sub = kmalloc(sizeof(*sub), GFP_ATOMIC);
291 if (!sub) {
292 pr_warn("Subscription rejected, no memory\n");
293 return -ENOMEM;
294 }
295
296 /* Initialize subscription object */
297 sub->seq.type = htohl(s->seq.type, swap);
298 sub->seq.lower = htohl(s->seq.lower, swap);
299 sub->seq.upper = htohl(s->seq.upper, swap);
300 sub->timeout = htohl(s->timeout, swap);
301 sub->filter = htohl(s->filter, swap);
302 if ((!(sub->filter & TIPC_SUB_PORTS) ==
303 !(sub->filter & TIPC_SUB_SERVICE)) ||
304 (sub->seq.lower > sub->seq.upper)) {
305 pr_warn("Subscription rejected, illegal request\n");
306 kfree(sub);
307 return -EINVAL;
308 }
309 INIT_LIST_HEAD(&sub->nameseq_list);
310 list_add(&sub->subscription_list, &subscriber->subscription_list);
311 sub->subscriber = subscriber;
312 sub->swap = swap;
313 memcpy(&sub->evt.s, s, sizeof(struct tipc_subscr));
314 atomic_inc(&subscription_count);
315 if (sub->timeout != TIPC_WAIT_FOREVER) {
316 k_init_timer(&sub->timer,
317 (Handler)subscr_timeout, (unsigned long)sub);
318 k_start_timer(&sub->timer, sub->timeout);
319 }
320 *sub_p = sub;
321 return 0;
322}
323
324/* Handle one termination request for the subscriber */
325static void subscr_conn_shutdown_event(int conid, void *usr_data)
326{
327 subscr_release((struct tipc_subscriber *)usr_data);
328}
329
330/* Handle one request to create a new subscription for the subscriber */
331static void subscr_conn_msg_event(int conid, struct sockaddr_tipc *addr,
332 void *usr_data, void *buf, size_t len)
333{
334 struct tipc_subscriber *subscriber = usr_data;
335 struct tipc_subscription *sub = NULL;
336
337 spin_lock_bh(&subscriber->lock);
338 if (subscr_subscribe((struct tipc_subscr *)buf, subscriber, &sub) < 0) {
339 spin_unlock_bh(&subscriber->lock);
340 subscr_terminate(subscriber);
341 return;
342 }
343 if (sub)
344 tipc_nametbl_subscribe(sub);
345 spin_unlock_bh(&subscriber->lock);
346}
347
348
349/* Handle one request to establish a new subscriber */
350static void *subscr_named_msg_event(int conid)
351{
352 struct tipc_subscriber *subscriber;
353
354 /* Create subscriber object */
355 subscriber = kzalloc(sizeof(struct tipc_subscriber), GFP_ATOMIC);
356 if (subscriber == NULL) {
357 pr_warn("Subscriber rejected, no memory\n");
358 return NULL;
359 }
360 INIT_LIST_HEAD(&subscriber->subscription_list);
361 subscriber->conid = conid;
362 spin_lock_init(&subscriber->lock);
363
364 return (void *)subscriber;
365}
366
367int tipc_subscr_start(void)
368{
369 return tipc_server_start(&topsrv);
370}
371
372void tipc_subscr_stop(void)
373{
374 tipc_server_stop(&topsrv);
375}
1/*
2 * net/tipc/subscr.c: TIPC network topology service
3 *
4 * Copyright (c) 2000-2017, Ericsson AB
5 * Copyright (c) 2005-2007, 2010-2013, Wind River Systems
6 * Copyright (c) 2020-2021, Red Hat Inc
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 "core.h"
39#include "name_table.h"
40#include "subscr.h"
41
42static void tipc_sub_send_event(struct tipc_subscription *sub,
43 struct publication *p,
44 u32 event)
45{
46 struct tipc_subscr *s = &sub->evt.s;
47 struct tipc_event *evt = &sub->evt;
48
49 if (sub->inactive)
50 return;
51 tipc_evt_write(evt, event, event);
52 if (p) {
53 tipc_evt_write(evt, found_lower, p->sr.lower);
54 tipc_evt_write(evt, found_upper, p->sr.upper);
55 tipc_evt_write(evt, port.ref, p->sk.ref);
56 tipc_evt_write(evt, port.node, p->sk.node);
57 } else {
58 tipc_evt_write(evt, found_lower, s->seq.lower);
59 tipc_evt_write(evt, found_upper, s->seq.upper);
60 tipc_evt_write(evt, port.ref, 0);
61 tipc_evt_write(evt, port.node, 0);
62 }
63 tipc_topsrv_queue_evt(sub->net, sub->conid, event, evt);
64}
65
66/**
67 * tipc_sub_check_overlap - test for subscription overlap with the given values
68 * @subscribed: the service range subscribed for
69 * @found: the service range we are checking for match
70 *
71 * Returns true if there is overlap, otherwise false.
72 */
73static bool tipc_sub_check_overlap(struct tipc_service_range *subscribed,
74 struct tipc_service_range *found)
75{
76 u32 found_lower = found->lower;
77 u32 found_upper = found->upper;
78
79 if (found_lower < subscribed->lower)
80 found_lower = subscribed->lower;
81 if (found_upper > subscribed->upper)
82 found_upper = subscribed->upper;
83 return found_lower <= found_upper;
84}
85
86void tipc_sub_report_overlap(struct tipc_subscription *sub,
87 struct publication *p,
88 u32 event, bool must)
89{
90 struct tipc_service_range *sr = &sub->s.seq;
91 u32 filter = sub->s.filter;
92
93 if (!tipc_sub_check_overlap(sr, &p->sr))
94 return;
95 if (!must && !(filter & TIPC_SUB_PORTS))
96 return;
97 if (filter & TIPC_SUB_CLUSTER_SCOPE && p->scope == TIPC_NODE_SCOPE)
98 return;
99 if (filter & TIPC_SUB_NODE_SCOPE && p->scope != TIPC_NODE_SCOPE)
100 return;
101 spin_lock(&sub->lock);
102 tipc_sub_send_event(sub, p, event);
103 spin_unlock(&sub->lock);
104}
105
106static void tipc_sub_timeout(struct timer_list *t)
107{
108 struct tipc_subscription *sub = from_timer(sub, t, timer);
109
110 spin_lock(&sub->lock);
111 tipc_sub_send_event(sub, NULL, TIPC_SUBSCR_TIMEOUT);
112 sub->inactive = true;
113 spin_unlock(&sub->lock);
114}
115
116static void tipc_sub_kref_release(struct kref *kref)
117{
118 kfree(container_of(kref, struct tipc_subscription, kref));
119}
120
121void tipc_sub_put(struct tipc_subscription *subscription)
122{
123 kref_put(&subscription->kref, tipc_sub_kref_release);
124}
125
126void tipc_sub_get(struct tipc_subscription *subscription)
127{
128 kref_get(&subscription->kref);
129}
130
131struct tipc_subscription *tipc_sub_subscribe(struct net *net,
132 struct tipc_subscr *s,
133 int conid)
134{
135 u32 lower = tipc_sub_read(s, seq.lower);
136 u32 upper = tipc_sub_read(s, seq.upper);
137 u32 filter = tipc_sub_read(s, filter);
138 struct tipc_subscription *sub;
139 u32 timeout;
140
141 if ((filter & TIPC_SUB_PORTS && filter & TIPC_SUB_SERVICE) ||
142 lower > upper) {
143 pr_warn("Subscription rejected, illegal request\n");
144 return NULL;
145 }
146 sub = kmalloc(sizeof(*sub), GFP_ATOMIC);
147 if (!sub) {
148 pr_warn("Subscription rejected, no memory\n");
149 return NULL;
150 }
151 INIT_LIST_HEAD(&sub->service_list);
152 INIT_LIST_HEAD(&sub->sub_list);
153 sub->net = net;
154 sub->conid = conid;
155 sub->inactive = false;
156 memcpy(&sub->evt.s, s, sizeof(*s));
157 sub->s.seq.type = tipc_sub_read(s, seq.type);
158 sub->s.seq.lower = lower;
159 sub->s.seq.upper = upper;
160 sub->s.filter = filter;
161 sub->s.timeout = tipc_sub_read(s, timeout);
162 memcpy(sub->s.usr_handle, s->usr_handle, 8);
163 spin_lock_init(&sub->lock);
164 kref_init(&sub->kref);
165 if (!tipc_nametbl_subscribe(sub)) {
166 kfree(sub);
167 return NULL;
168 }
169 timer_setup(&sub->timer, tipc_sub_timeout, 0);
170 timeout = tipc_sub_read(&sub->evt.s, timeout);
171 if (timeout != TIPC_WAIT_FOREVER)
172 mod_timer(&sub->timer, jiffies + msecs_to_jiffies(timeout));
173 return sub;
174}
175
176void tipc_sub_unsubscribe(struct tipc_subscription *sub)
177{
178 tipc_nametbl_unsubscribe(sub);
179 if (sub->evt.s.timeout != TIPC_WAIT_FOREVER)
180 del_timer_sync(&sub->timer);
181 list_del(&sub->sub_list);
182 tipc_sub_put(sub);
183}