1 /* 1 /*
2 * net/tipc/subscr.c: TIPC network topology se 2 * net/tipc/subscr.c: TIPC network topology service
3 * 3 *
4 * Copyright (c) 2000-2017, Ericsson AB !! 4 * Copyright (c) 2000-2006, Ericsson AB
5 * Copyright (c) 2005-2007, 2010-2013, Wind Ri !! 5 * Copyright (c) 2005-2007, 2010-2011, Wind River Systems
6 * Copyright (c) 2020-2021, Red Hat Inc <<
7 * All rights reserved. 6 * All rights reserved.
8 * 7 *
9 * Redistribution and use in source and binary 8 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that t 9 * modification, are permitted provided that the following conditions are met:
11 * 10 *
12 * 1. Redistributions of source code must reta 11 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the 12 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must repr 13 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the 14 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials pro 15 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the names of the copyright holde 16 * 3. Neither the names of the copyright holders nor the names of its
18 * contributors may be used to endorse or p 17 * contributors may be used to endorse or promote products derived from
19 * this software without specific prior wri 18 * this software without specific prior written permission.
20 * 19 *
21 * Alternatively, this software may be distrib 20 * Alternatively, this software may be distributed under the terms of the
22 * GNU General Public License ("GPL") version 21 * GNU General Public License ("GPL") version 2 as published by the Free
23 * Software Foundation. 22 * Software Foundation.
24 * 23 *
25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT 24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
26 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCL 25 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND F 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYR 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
29 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL 28 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT L 29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THE 31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUD 32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 * ARISING IN ANY WAY OUT OF THE USE OF THIS S 33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35 * POSSIBILITY OF SUCH DAMAGE. 34 * POSSIBILITY OF SUCH DAMAGE.
36 */ 35 */
37 36
38 #include "core.h" 37 #include "core.h"
39 #include "name_table.h" 38 #include "name_table.h"
>> 39 #include "port.h"
40 #include "subscr.h" 40 #include "subscr.h"
41 41
42 static void tipc_sub_send_event(struct tipc_su !! 42 /**
43 struct publica !! 43 * struct tipc_subscriber - TIPC network topology subscriber
44 u32 event) !! 44 * @port_ref: object reference to server port connecting to subscriber
45 { !! 45 * @lock: pointer to spinlock controlling access to subscriber's server port
46 struct tipc_subscr *s = &sub->evt.s; !! 46 * @subscriber_list: adjacent subscribers in top. server's list of subscribers
47 struct tipc_event *evt = &sub->evt; !! 47 * @subscription_list: list of subscription objects for this subscriber
48 !! 48 */
49 if (sub->inactive) !! 49 struct tipc_subscriber {
50 return; !! 50 u32 port_ref;
51 tipc_evt_write(evt, event, event); !! 51 spinlock_t *lock;
52 if (p) { !! 52 struct list_head subscriber_list;
53 tipc_evt_write(evt, found_lowe !! 53 struct list_head subscription_list;
54 tipc_evt_write(evt, found_uppe !! 54 };
55 tipc_evt_write(evt, port.ref, !! 55
56 tipc_evt_write(evt, port.node, !! 56 /**
57 } else { !! 57 * struct top_srv - TIPC network topology subscription service
58 tipc_evt_write(evt, found_lowe !! 58 * @setup_port: reference to TIPC port that handles subscription requests
59 tipc_evt_write(evt, found_uppe !! 59 * @subscription_count: number of active subscriptions (not subscribers!)
60 tipc_evt_write(evt, port.ref, !! 60 * @subscriber_list: list of ports subscribing to service
61 tipc_evt_write(evt, port.node, !! 61 * @lock: spinlock govering access to subscriber list
62 } !! 62 */
63 tipc_topsrv_queue_evt(sub->net, sub->c !! 63 struct top_srv {
>> 64 u32 setup_port;
>> 65 atomic_t subscription_count;
>> 66 struct list_head subscriber_list;
>> 67 spinlock_t lock;
>> 68 };
>> 69
>> 70 static struct top_srv topsrv;
>> 71
>> 72 /**
>> 73 * htohl - convert value to endianness used by destination
>> 74 * @in: value to convert
>> 75 * @swap: non-zero if endianness must be reversed
>> 76 *
>> 77 * Returns converted value
>> 78 */
>> 79 static u32 htohl(u32 in, int swap)
>> 80 {
>> 81 return swap ? swab32(in) : in;
64 } 82 }
65 83
66 /** 84 /**
67 * tipc_sub_check_overlap - test for subscript !! 85 * subscr_send_event - send a message containing a tipc_event to the subscriber
68 * @subscribed: the service range subscribed f <<
69 * @found: the service range we are checking f <<
70 * 86 *
71 * Returns true if there is overlap, otherwise !! 87 * Note: Must not hold subscriber's server port lock, since tipc_send() will
>> 88 * try to take the lock if the message is rejected and returned!
72 */ 89 */
73 static bool tipc_sub_check_overlap(struct tipc !! 90 static void subscr_send_event(struct tipc_subscription *sub,
74 struct tipc !! 91 u32 found_lower,
>> 92 u32 found_upper,
>> 93 u32 event,
>> 94 u32 port_ref,
>> 95 u32 node)
75 { 96 {
76 u32 found_lower = found->lower; !! 97 struct iovec msg_sect;
77 u32 found_upper = found->upper; !! 98
>> 99 msg_sect.iov_base = (void *)&sub->evt;
>> 100 msg_sect.iov_len = sizeof(struct tipc_event);
78 101
79 if (found_lower < subscribed->lower) !! 102 sub->evt.event = htohl(event, sub->swap);
80 found_lower = subscribed->lowe !! 103 sub->evt.found_lower = htohl(found_lower, sub->swap);
81 if (found_upper > subscribed->upper) !! 104 sub->evt.found_upper = htohl(found_upper, sub->swap);
82 found_upper = subscribed->uppe !! 105 sub->evt.port.ref = htohl(port_ref, sub->swap);
83 return found_lower <= found_upper; !! 106 sub->evt.port.node = htohl(node, sub->swap);
>> 107 tipc_send(sub->server_ref, 1, &msg_sect, msg_sect.iov_len);
84 } 108 }
85 109
86 void tipc_sub_report_overlap(struct tipc_subsc !! 110 /**
87 struct publicatio !! 111 * tipc_subscr_overlap - test for subscription overlap with the given values
88 u32 event, bool m !! 112 *
>> 113 * Returns 1 if there is overlap, otherwise 0.
>> 114 */
>> 115 int tipc_subscr_overlap(struct tipc_subscription *sub,
>> 116 u32 found_lower,
>> 117 u32 found_upper)
>> 118
89 { 119 {
90 struct tipc_service_range *sr = &sub-> !! 120 if (found_lower < sub->seq.lower)
91 u32 filter = sub->s.filter; !! 121 found_lower = sub->seq.lower;
>> 122 if (found_upper > sub->seq.upper)
>> 123 found_upper = sub->seq.upper;
>> 124 if (found_lower > found_upper)
>> 125 return 0;
>> 126 return 1;
>> 127 }
92 128
93 if (!tipc_sub_check_overlap(sr, &p->sr !! 129 /**
94 return; !! 130 * tipc_subscr_report_overlap - issue event if there is subscription overlap
95 if (!must && !(filter & TIPC_SUB_PORTS !! 131 *
96 return; !! 132 * Protected by nameseq.lock in name_table.c
97 if (filter & TIPC_SUB_CLUSTER_SCOPE && !! 133 */
>> 134 void tipc_subscr_report_overlap(struct tipc_subscription *sub,
>> 135 u32 found_lower,
>> 136 u32 found_upper,
>> 137 u32 event,
>> 138 u32 port_ref,
>> 139 u32 node,
>> 140 int must)
>> 141 {
>> 142 if (!tipc_subscr_overlap(sub, found_lower, found_upper))
98 return; 143 return;
99 if (filter & TIPC_SUB_NODE_SCOPE && p- !! 144 if (!must && !(sub->filter & TIPC_SUB_PORTS))
100 return; 145 return;
101 spin_lock(&sub->lock); !! 146
102 tipc_sub_send_event(sub, p, event); !! 147 subscr_send_event(sub, found_lower, found_upper, event, port_ref, node);
103 spin_unlock(&sub->lock); <<
104 } 148 }
105 149
106 static void tipc_sub_timeout(struct timer_list !! 150 /**
>> 151 * subscr_timeout - subscription timeout has occurred
>> 152 */
>> 153 static void subscr_timeout(struct tipc_subscription *sub)
107 { 154 {
108 struct tipc_subscription *sub = from_t !! 155 struct tipc_port *server_port;
>> 156
>> 157 /* Validate server port reference (in case subscriber is terminating) */
>> 158 server_port = tipc_port_lock(sub->server_ref);
>> 159 if (server_port == NULL)
>> 160 return;
109 161
110 spin_lock(&sub->lock); !! 162 /* Validate timeout (in case subscription is being cancelled) */
111 tipc_sub_send_event(sub, NULL, TIPC_SU !! 163 if (sub->timeout == TIPC_WAIT_FOREVER) {
112 sub->inactive = true; !! 164 tipc_port_unlock(server_port);
113 spin_unlock(&sub->lock); !! 165 return;
>> 166 }
>> 167
>> 168 /* Unlink subscription from name table */
>> 169 tipc_nametbl_unsubscribe(sub);
>> 170
>> 171 /* Unlink subscription from subscriber */
>> 172 list_del(&sub->subscription_list);
>> 173
>> 174 /* Release subscriber's server port */
>> 175 tipc_port_unlock(server_port);
>> 176
>> 177 /* Notify subscriber of timeout */
>> 178 subscr_send_event(sub, sub->evt.s.seq.lower, sub->evt.s.seq.upper,
>> 179 TIPC_SUBSCR_TIMEOUT, 0, 0);
>> 180
>> 181 /* Now destroy subscription */
>> 182 k_term_timer(&sub->timer);
>> 183 kfree(sub);
>> 184 atomic_dec(&topsrv.subscription_count);
114 } 185 }
115 186
116 static void tipc_sub_kref_release(struct kref !! 187 /**
>> 188 * subscr_del - delete a subscription within a subscription list
>> 189 *
>> 190 * Called with subscriber port locked.
>> 191 */
>> 192 static void subscr_del(struct tipc_subscription *sub)
117 { 193 {
118 kfree(container_of(kref, struct tipc_s !! 194 tipc_nametbl_unsubscribe(sub);
>> 195 list_del(&sub->subscription_list);
>> 196 kfree(sub);
>> 197 atomic_dec(&topsrv.subscription_count);
119 } 198 }
120 199
121 void tipc_sub_put(struct tipc_subscription *su !! 200 /**
>> 201 * subscr_terminate - terminate communication with a subscriber
>> 202 *
>> 203 * Called with subscriber port locked. Routine must temporarily release lock
>> 204 * to enable subscription timeout routine(s) to finish without deadlocking;
>> 205 * the lock is then reclaimed to allow caller to release it upon return.
>> 206 * (This should work even in the unlikely event some other thread creates
>> 207 * a new object reference in the interim that uses this lock; this routine will
>> 208 * simply wait for it to be released, then claim it.)
>> 209 */
>> 210 static void subscr_terminate(struct tipc_subscriber *subscriber)
122 { 211 {
123 kref_put(&subscription->kref, tipc_sub !! 212 u32 port_ref;
>> 213 struct tipc_subscription *sub;
>> 214 struct tipc_subscription *sub_temp;
>> 215
>> 216 /* Invalidate subscriber reference */
>> 217 port_ref = subscriber->port_ref;
>> 218 subscriber->port_ref = 0;
>> 219 spin_unlock_bh(subscriber->lock);
>> 220
>> 221 /* Sever connection to subscriber */
>> 222 tipc_shutdown(port_ref);
>> 223 tipc_deleteport(port_ref);
>> 224
>> 225 /* Destroy any existing subscriptions for subscriber */
>> 226 list_for_each_entry_safe(sub, sub_temp, &subscriber->subscription_list,
>> 227 subscription_list) {
>> 228 if (sub->timeout != TIPC_WAIT_FOREVER) {
>> 229 k_cancel_timer(&sub->timer);
>> 230 k_term_timer(&sub->timer);
>> 231 }
>> 232 subscr_del(sub);
>> 233 }
>> 234
>> 235 /* Remove subscriber from topology server's subscriber list */
>> 236 spin_lock_bh(&topsrv.lock);
>> 237 list_del(&subscriber->subscriber_list);
>> 238 spin_unlock_bh(&topsrv.lock);
>> 239
>> 240 /* Reclaim subscriber lock */
>> 241 spin_lock_bh(subscriber->lock);
>> 242
>> 243 /* Now destroy subscriber */
>> 244 kfree(subscriber);
124 } 245 }
125 246
126 void tipc_sub_get(struct tipc_subscription *su !! 247 /**
>> 248 * subscr_cancel - handle subscription cancellation request
>> 249 *
>> 250 * Called with subscriber port locked. Routine must temporarily release lock
>> 251 * to enable the subscription timeout routine to finish without deadlocking;
>> 252 * the lock is then reclaimed to allow caller to release it upon return.
>> 253 *
>> 254 * Note that fields of 's' use subscriber's endianness!
>> 255 */
>> 256 static void subscr_cancel(struct tipc_subscr *s,
>> 257 struct tipc_subscriber *subscriber)
127 { 258 {
128 kref_get(&subscription->kref); !! 259 struct tipc_subscription *sub;
>> 260 struct tipc_subscription *sub_temp;
>> 261 int found = 0;
>> 262
>> 263 /* Find first matching subscription, exit if not found */
>> 264 list_for_each_entry_safe(sub, sub_temp, &subscriber->subscription_list,
>> 265 subscription_list) {
>> 266 if (!memcmp(s, &sub->evt.s, sizeof(struct tipc_subscr))) {
>> 267 found = 1;
>> 268 break;
>> 269 }
>> 270 }
>> 271 if (!found)
>> 272 return;
>> 273
>> 274 /* Cancel subscription timer (if used), then delete subscription */
>> 275 if (sub->timeout != TIPC_WAIT_FOREVER) {
>> 276 sub->timeout = TIPC_WAIT_FOREVER;
>> 277 spin_unlock_bh(subscriber->lock);
>> 278 k_cancel_timer(&sub->timer);
>> 279 k_term_timer(&sub->timer);
>> 280 spin_lock_bh(subscriber->lock);
>> 281 }
>> 282 subscr_del(sub);
129 } 283 }
130 284
131 struct tipc_subscription *tipc_sub_subscribe(s !! 285 /**
132 s !! 286 * subscr_subscribe - create subscription for subscriber
133 i !! 287 *
>> 288 * Called with subscriber port locked.
>> 289 */
>> 290 static struct tipc_subscription *subscr_subscribe(struct tipc_subscr *s,
>> 291 struct tipc_subscriber *subscriber)
134 { 292 {
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; 293 struct tipc_subscription *sub;
139 u32 timeout; !! 294 int swap;
140 295
141 if ((filter & TIPC_SUB_PORTS && filter !! 296 /* Determine subscriber's endianness */
142 lower > upper) { !! 297 swap = !(s->filter & (TIPC_SUB_PORTS | TIPC_SUB_SERVICE));
143 pr_warn("Subscription rejected !! 298
>> 299 /* Detect & process a subscription cancellation request */
>> 300 if (s->filter & htohl(TIPC_SUB_CANCEL, swap)) {
>> 301 s->filter &= ~htohl(TIPC_SUB_CANCEL, swap);
>> 302 subscr_cancel(s, subscriber);
>> 303 return NULL;
>> 304 }
>> 305
>> 306 /* Refuse subscription if global limit exceeded */
>> 307 if (atomic_read(&topsrv.subscription_count) >= TIPC_MAX_SUBSCRIPTIONS) {
>> 308 pr_warn("Subscription rejected, limit reached (%u)\n",
>> 309 TIPC_MAX_SUBSCRIPTIONS);
>> 310 subscr_terminate(subscriber);
144 return NULL; 311 return NULL;
145 } 312 }
>> 313
>> 314 /* Allocate subscription object */
146 sub = kmalloc(sizeof(*sub), GFP_ATOMIC 315 sub = kmalloc(sizeof(*sub), GFP_ATOMIC);
147 if (!sub) { 316 if (!sub) {
148 pr_warn("Subscription rejected 317 pr_warn("Subscription rejected, no memory\n");
>> 318 subscr_terminate(subscriber);
149 return NULL; 319 return NULL;
150 } 320 }
151 INIT_LIST_HEAD(&sub->service_list); !! 321
152 INIT_LIST_HEAD(&sub->sub_list); !! 322 /* Initialize subscription object */
153 sub->net = net; !! 323 sub->seq.type = htohl(s->seq.type, swap);
154 sub->conid = conid; !! 324 sub->seq.lower = htohl(s->seq.lower, swap);
155 sub->inactive = false; !! 325 sub->seq.upper = htohl(s->seq.upper, swap);
156 memcpy(&sub->evt.s, s, sizeof(*s)); !! 326 sub->timeout = htohl(s->timeout, swap);
157 sub->s.seq.type = tipc_sub_read(s, seq !! 327 sub->filter = htohl(s->filter, swap);
158 sub->s.seq.lower = lower; !! 328 if ((!(sub->filter & TIPC_SUB_PORTS) ==
159 sub->s.seq.upper = upper; !! 329 !(sub->filter & TIPC_SUB_SERVICE)) ||
160 sub->s.filter = filter; !! 330 (sub->seq.lower > sub->seq.upper)) {
161 sub->s.timeout = tipc_sub_read(s, time !! 331 pr_warn("Subscription rejected, illegal request\n");
162 memcpy(sub->s.usr_handle, s->usr_handl <<
163 spin_lock_init(&sub->lock); <<
164 kref_init(&sub->kref); <<
165 if (!tipc_nametbl_subscribe(sub)) { <<
166 kfree(sub); 332 kfree(sub);
>> 333 subscr_terminate(subscriber);
167 return NULL; 334 return NULL;
168 } 335 }
169 timer_setup(&sub->timer, tipc_sub_time !! 336 INIT_LIST_HEAD(&sub->nameseq_list);
170 timeout = tipc_sub_read(&sub->evt.s, t !! 337 list_add(&sub->subscription_list, &subscriber->subscription_list);
171 if (timeout != TIPC_WAIT_FOREVER) !! 338 sub->server_ref = subscriber->port_ref;
172 mod_timer(&sub->timer, jiffies !! 339 sub->swap = swap;
>> 340 memcpy(&sub->evt.s, s, sizeof(struct tipc_subscr));
>> 341 atomic_inc(&topsrv.subscription_count);
>> 342 if (sub->timeout != TIPC_WAIT_FOREVER) {
>> 343 k_init_timer(&sub->timer,
>> 344 (Handler)subscr_timeout, (unsigned long)sub);
>> 345 k_start_timer(&sub->timer, sub->timeout);
>> 346 }
>> 347
173 return sub; 348 return sub;
174 } 349 }
175 350
176 void tipc_sub_unsubscribe(struct tipc_subscrip !! 351 /**
>> 352 * subscr_conn_shutdown_event - handle termination request from subscriber
>> 353 *
>> 354 * Called with subscriber's server port unlocked.
>> 355 */
>> 356 static void subscr_conn_shutdown_event(void *usr_handle,
>> 357 u32 port_ref,
>> 358 struct sk_buff **buf,
>> 359 unsigned char const *data,
>> 360 unsigned int size,
>> 361 int reason)
>> 362 {
>> 363 struct tipc_subscriber *subscriber = usr_handle;
>> 364 spinlock_t *subscriber_lock;
>> 365
>> 366 if (tipc_port_lock(port_ref) == NULL)
>> 367 return;
>> 368
>> 369 subscriber_lock = subscriber->lock;
>> 370 subscr_terminate(subscriber);
>> 371 spin_unlock_bh(subscriber_lock);
>> 372 }
>> 373
>> 374 /**
>> 375 * subscr_conn_msg_event - handle new subscription request from subscriber
>> 376 *
>> 377 * Called with subscriber's server port unlocked.
>> 378 */
>> 379 static void subscr_conn_msg_event(void *usr_handle,
>> 380 u32 port_ref,
>> 381 struct sk_buff **buf,
>> 382 const unchar *data,
>> 383 u32 size)
177 { 384 {
178 tipc_nametbl_unsubscribe(sub); !! 385 struct tipc_subscriber *subscriber = usr_handle;
179 if (sub->evt.s.timeout != TIPC_WAIT_FO !! 386 spinlock_t *subscriber_lock;
180 del_timer_sync(&sub->timer); !! 387 struct tipc_subscription *sub;
181 list_del(&sub->sub_list); !! 388
182 tipc_sub_put(sub); !! 389 /*
>> 390 * Lock subscriber's server port (& make a local copy of lock pointer,
>> 391 * in case subscriber is deleted while processing subscription request)
>> 392 */
>> 393 if (tipc_port_lock(port_ref) == NULL)
>> 394 return;
>> 395
>> 396 subscriber_lock = subscriber->lock;
>> 397
>> 398 if (size != sizeof(struct tipc_subscr)) {
>> 399 subscr_terminate(subscriber);
>> 400 spin_unlock_bh(subscriber_lock);
>> 401 } else {
>> 402 sub = subscr_subscribe((struct tipc_subscr *)data, subscriber);
>> 403 spin_unlock_bh(subscriber_lock);
>> 404 if (sub != NULL) {
>> 405
>> 406 /*
>> 407 * We must release the server port lock before adding a
>> 408 * subscription to the name table since TIPC needs to be
>> 409 * able to (re)acquire the port lock if an event message
>> 410 * issued by the subscription process is rejected and
>> 411 * returned. The subscription cannot be deleted while
>> 412 * it is being added to the name table because:
>> 413 * a) the single-threading of the native API port code
>> 414 * ensures the subscription cannot be cancelled and
>> 415 * the subscriber connection cannot be broken, and
>> 416 * b) the name table lock ensures the subscription
>> 417 * timeout code cannot delete the subscription,
>> 418 * so the subscription object is still protected.
>> 419 */
>> 420 tipc_nametbl_subscribe(sub);
>> 421 }
>> 422 }
>> 423 }
>> 424
>> 425 /**
>> 426 * subscr_named_msg_event - handle request to establish a new subscriber
>> 427 */
>> 428 static void subscr_named_msg_event(void *usr_handle,
>> 429 u32 port_ref,
>> 430 struct sk_buff **buf,
>> 431 const unchar *data,
>> 432 u32 size,
>> 433 u32 importance,
>> 434 struct tipc_portid const *orig,
>> 435 struct tipc_name_seq const *dest)
>> 436 {
>> 437 struct tipc_subscriber *subscriber;
>> 438 u32 server_port_ref;
>> 439
>> 440 /* Create subscriber object */
>> 441 subscriber = kzalloc(sizeof(struct tipc_subscriber), GFP_ATOMIC);
>> 442 if (subscriber == NULL) {
>> 443 pr_warn("Subscriber rejected, no memory\n");
>> 444 return;
>> 445 }
>> 446 INIT_LIST_HEAD(&subscriber->subscription_list);
>> 447 INIT_LIST_HEAD(&subscriber->subscriber_list);
>> 448
>> 449 /* Create server port & establish connection to subscriber */
>> 450 tipc_createport(subscriber,
>> 451 importance,
>> 452 NULL,
>> 453 NULL,
>> 454 subscr_conn_shutdown_event,
>> 455 NULL,
>> 456 NULL,
>> 457 subscr_conn_msg_event,
>> 458 NULL,
>> 459 &subscriber->port_ref);
>> 460 if (subscriber->port_ref == 0) {
>> 461 pr_warn("Subscriber rejected, unable to create port\n");
>> 462 kfree(subscriber);
>> 463 return;
>> 464 }
>> 465 tipc_connect(subscriber->port_ref, orig);
>> 466
>> 467 /* Lock server port (& save lock address for future use) */
>> 468 subscriber->lock = tipc_port_lock(subscriber->port_ref)->lock;
>> 469
>> 470 /* Add subscriber to topology server's subscriber list */
>> 471 spin_lock_bh(&topsrv.lock);
>> 472 list_add(&subscriber->subscriber_list, &topsrv.subscriber_list);
>> 473 spin_unlock_bh(&topsrv.lock);
>> 474
>> 475 /* Unlock server port */
>> 476 server_port_ref = subscriber->port_ref;
>> 477 spin_unlock_bh(subscriber->lock);
>> 478
>> 479 /* Send an ACK- to complete connection handshaking */
>> 480 tipc_send(server_port_ref, 0, NULL, 0);
>> 481
>> 482 /* Handle optional subscription request */
>> 483 if (size != 0) {
>> 484 subscr_conn_msg_event(subscriber, server_port_ref,
>> 485 buf, data, size);
>> 486 }
>> 487 }
>> 488
>> 489 int tipc_subscr_start(void)
>> 490 {
>> 491 struct tipc_name_seq seq = {TIPC_TOP_SRV, TIPC_TOP_SRV, TIPC_TOP_SRV};
>> 492 int res;
>> 493
>> 494 spin_lock_init(&topsrv.lock);
>> 495 INIT_LIST_HEAD(&topsrv.subscriber_list);
>> 496
>> 497 res = tipc_createport(NULL,
>> 498 TIPC_CRITICAL_IMPORTANCE,
>> 499 NULL,
>> 500 NULL,
>> 501 NULL,
>> 502 NULL,
>> 503 subscr_named_msg_event,
>> 504 NULL,
>> 505 NULL,
>> 506 &topsrv.setup_port);
>> 507 if (res)
>> 508 goto failed;
>> 509
>> 510 res = tipc_publish(topsrv.setup_port, TIPC_NODE_SCOPE, &seq);
>> 511 if (res) {
>> 512 tipc_deleteport(topsrv.setup_port);
>> 513 topsrv.setup_port = 0;
>> 514 goto failed;
>> 515 }
>> 516
>> 517 return 0;
>> 518
>> 519 failed:
>> 520 pr_err("Failed to create subscription service\n");
>> 521 return res;
>> 522 }
>> 523
>> 524 void tipc_subscr_stop(void)
>> 525 {
>> 526 struct tipc_subscriber *subscriber;
>> 527 struct tipc_subscriber *subscriber_temp;
>> 528 spinlock_t *subscriber_lock;
>> 529
>> 530 if (topsrv.setup_port) {
>> 531 tipc_deleteport(topsrv.setup_port);
>> 532 topsrv.setup_port = 0;
>> 533
>> 534 list_for_each_entry_safe(subscriber, subscriber_temp,
>> 535 &topsrv.subscriber_list,
>> 536 subscriber_list) {
>> 537 subscriber_lock = subscriber->lock;
>> 538 spin_lock_bh(subscriber_lock);
>> 539 subscr_terminate(subscriber);
>> 540 spin_unlock_bh(subscriber_lock);
>> 541 }
>> 542 }
183 } 543 }
184 544
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