1 /*
2 * net/tipc/server.c: TIPC server infrastructure
3 *
4 * Copyright (c) 2012-2013, Wind River Systems
5 * Copyright (c) 2017-2018, Ericsson AB
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 "subscr.h"
38 #include "topsrv.h"
39 #include "core.h"
40 #include "socket.h"
41 #include "addr.h"
42 #include "msg.h"
43 #include "bearer.h"
44 #include <net/sock.h>
45 #include <linux/module.h>
46 #include <trace/events/sock.h>
47
48 /* Number of messages to send before rescheduling */
49 #define MAX_SEND_MSG_COUNT 25
50 #define MAX_RECV_MSG_COUNT 25
51 #define CF_CONNECTED 1
52
53 #define TIPC_SERVER_NAME_LEN 32
54
55 /**
56 * struct tipc_topsrv - TIPC server structure
57 * @conn_idr: identifier set of connection
58 * @idr_lock: protect the connection identifier set and listener
59 * @idr_in_use: amount of allocated identifier entry
60 * @net: network namespace instance
61 * @awork: accept work item
62 * @rcv_wq: receive workqueue
63 * @send_wq: send workqueue
64 * @listener: topsrv listener socket
65 * @name: server name
66 */
67 struct tipc_topsrv {
68 struct idr conn_idr;
69 spinlock_t idr_lock; /* for idr list */
70 int idr_in_use;
71 struct net *net;
72 struct work_struct awork;
73 struct workqueue_struct *rcv_wq;
74 struct workqueue_struct *send_wq;
75 struct socket *listener;
76 char name[TIPC_SERVER_NAME_LEN];
77 };
78
79 /**
80 * struct tipc_conn - TIPC connection structure
81 * @kref: reference counter to connection object
82 * @conid: connection identifier
83 * @sock: socket handler associated with connection
84 * @flags: indicates connection state
85 * @server: pointer to connected server
86 * @sub_list: list to all pertaining subscriptions
87 * @sub_lock: lock protecting the subscription list
88 * @rwork: receive work item
89 * @outqueue: pointer to first outbound message in queue
90 * @outqueue_lock: control access to the outqueue
91 * @swork: send work item
92 */
93 struct tipc_conn {
94 struct kref kref;
95 int conid;
96 struct socket *sock;
97 unsigned long flags;
98 struct tipc_topsrv *server;
99 struct list_head sub_list;
100 spinlock_t sub_lock; /* for subscription list */
101 struct work_struct rwork;
102 struct list_head outqueue;
103 spinlock_t outqueue_lock; /* for outqueue */
104 struct work_struct swork;
105 };
106
107 /* An entry waiting to be sent */
108 struct outqueue_entry {
109 bool inactive;
110 struct tipc_event evt;
111 struct list_head list;
112 };
113
114 static void tipc_conn_recv_work(struct work_struct *work);
115 static void tipc_conn_send_work(struct work_struct *work);
116 static void tipc_topsrv_kern_evt(struct net *net, struct tipc_event *evt);
117 static void tipc_conn_delete_sub(struct tipc_conn *con, struct tipc_subscr *s);
118
connected(struct tipc_conn * con)119 static bool connected(struct tipc_conn *con)
120 {
121 return con && test_bit(CF_CONNECTED, &con->flags);
122 }
123
tipc_conn_kref_release(struct kref * kref)124 static void tipc_conn_kref_release(struct kref *kref)
125 {
126 struct tipc_conn *con = container_of(kref, struct tipc_conn, kref);
127 struct tipc_topsrv *s = con->server;
128 struct outqueue_entry *e, *safe;
129
130 spin_lock_bh(&s->idr_lock);
131 idr_remove(&s->conn_idr, con->conid);
132 s->idr_in_use--;
133 spin_unlock_bh(&s->idr_lock);
134 if (con->sock)
135 sock_release(con->sock);
136
137 spin_lock_bh(&con->outqueue_lock);
138 list_for_each_entry_safe(e, safe, &con->outqueue, list) {
139 list_del(&e->list);
140 kfree(e);
141 }
142 spin_unlock_bh(&con->outqueue_lock);
143 kfree(con);
144 }
145
conn_put(struct tipc_conn * con)146 static void conn_put(struct tipc_conn *con)
147 {
148 kref_put(&con->kref, tipc_conn_kref_release);
149 }
150
conn_get(struct tipc_conn * con)151 static void conn_get(struct tipc_conn *con)
152 {
153 kref_get(&con->kref);
154 }
155
tipc_conn_close(struct tipc_conn * con)156 static void tipc_conn_close(struct tipc_conn *con)
157 {
158 struct sock *sk = con->sock->sk;
159 bool disconnect = false;
160
161 write_lock_bh(&sk->sk_callback_lock);
162 disconnect = test_and_clear_bit(CF_CONNECTED, &con->flags);
163
164 if (disconnect) {
165 sk->sk_user_data = NULL;
166 tipc_conn_delete_sub(con, NULL);
167 }
168 write_unlock_bh(&sk->sk_callback_lock);
169
170 /* Handle concurrent calls from sending and receiving threads */
171 if (!disconnect)
172 return;
173
174 /* Don't flush pending works, -just let them expire */
175 kernel_sock_shutdown(con->sock, SHUT_RDWR);
176
177 conn_put(con);
178 }
179
tipc_conn_alloc(struct tipc_topsrv * s,struct socket * sock)180 static struct tipc_conn *tipc_conn_alloc(struct tipc_topsrv *s, struct socket *sock)
181 {
182 struct tipc_conn *con;
183 int ret;
184
185 con = kzalloc_obj(*con, GFP_ATOMIC);
186 if (!con)
187 return ERR_PTR(-ENOMEM);
188
189 kref_init(&con->kref);
190 INIT_LIST_HEAD(&con->outqueue);
191 INIT_LIST_HEAD(&con->sub_list);
192 spin_lock_init(&con->outqueue_lock);
193 spin_lock_init(&con->sub_lock);
194 INIT_WORK(&con->swork, tipc_conn_send_work);
195 INIT_WORK(&con->rwork, tipc_conn_recv_work);
196
197 spin_lock_bh(&s->idr_lock);
198 ret = idr_alloc(&s->conn_idr, con, 0, 0, GFP_ATOMIC);
199 if (ret < 0) {
200 kfree(con);
201 spin_unlock_bh(&s->idr_lock);
202 return ERR_PTR(-ENOMEM);
203 }
204 con->conid = ret;
205 s->idr_in_use++;
206
207 set_bit(CF_CONNECTED, &con->flags);
208 con->server = s;
209 con->sock = sock;
210 conn_get(con);
211 spin_unlock_bh(&s->idr_lock);
212
213 return con;
214 }
215
tipc_conn_lookup(struct tipc_topsrv * s,int conid)216 static struct tipc_conn *tipc_conn_lookup(struct tipc_topsrv *s, int conid)
217 {
218 struct tipc_conn *con;
219
220 spin_lock_bh(&s->idr_lock);
221 if (!s->listener) {
222 spin_unlock_bh(&s->idr_lock);
223 return NULL;
224 }
225 con = idr_find(&s->conn_idr, conid);
226 if (!connected(con) || !kref_get_unless_zero(&con->kref))
227 con = NULL;
228 spin_unlock_bh(&s->idr_lock);
229 return con;
230 }
231
232 /* tipc_conn_delete_sub - delete a specific or all subscriptions
233 * for a given subscriber
234 */
tipc_conn_delete_sub(struct tipc_conn * con,struct tipc_subscr * s)235 static void tipc_conn_delete_sub(struct tipc_conn *con, struct tipc_subscr *s)
236 {
237 struct tipc_net *tn = tipc_net(con->server->net);
238 struct list_head *sub_list = &con->sub_list;
239 struct tipc_subscription *sub, *tmp;
240
241 spin_lock_bh(&con->sub_lock);
242 list_for_each_entry_safe(sub, tmp, sub_list, sub_list) {
243 if (!s || !memcmp(s, &sub->evt.s, sizeof(*s))) {
244 tipc_sub_unsubscribe(sub);
245 atomic_dec(&tn->subscription_count);
246 if (s)
247 break;
248 }
249 }
250 spin_unlock_bh(&con->sub_lock);
251 }
252
tipc_conn_send_to_sock(struct tipc_conn * con)253 static void tipc_conn_send_to_sock(struct tipc_conn *con)
254 {
255 struct list_head *queue = &con->outqueue;
256 struct tipc_topsrv *srv = con->server;
257 struct outqueue_entry *e;
258 struct tipc_event *evt;
259 struct msghdr msg;
260 struct kvec iov;
261 int count = 0;
262 int ret;
263
264 spin_lock_bh(&con->outqueue_lock);
265
266 while (!list_empty(queue)) {
267 e = list_first_entry(queue, struct outqueue_entry, list);
268 evt = &e->evt;
269 spin_unlock_bh(&con->outqueue_lock);
270
271 if (e->inactive)
272 tipc_conn_delete_sub(con, &evt->s);
273
274 memset(&msg, 0, sizeof(msg));
275 msg.msg_flags = MSG_DONTWAIT;
276 iov.iov_base = evt;
277 iov.iov_len = sizeof(*evt);
278 msg.msg_name = NULL;
279
280 if (con->sock) {
281 ret = kernel_sendmsg(con->sock, &msg, &iov,
282 1, sizeof(*evt));
283 if (ret == -EWOULDBLOCK || ret == 0) {
284 cond_resched();
285 return;
286 } else if (ret < 0) {
287 return tipc_conn_close(con);
288 }
289 } else {
290 tipc_topsrv_kern_evt(srv->net, evt);
291 }
292
293 /* Don't starve users filling buffers */
294 if (++count >= MAX_SEND_MSG_COUNT) {
295 cond_resched();
296 count = 0;
297 }
298 spin_lock_bh(&con->outqueue_lock);
299 list_del(&e->list);
300 kfree(e);
301 }
302 spin_unlock_bh(&con->outqueue_lock);
303 }
304
tipc_conn_send_work(struct work_struct * work)305 static void tipc_conn_send_work(struct work_struct *work)
306 {
307 struct tipc_conn *con = container_of(work, struct tipc_conn, swork);
308 struct tipc_topsrv *srv;
309
310 srv = con->server;
311 spin_lock_bh(&srv->idr_lock);
312 if (!srv->listener) {
313 spin_unlock_bh(&srv->idr_lock);
314 goto out;
315 }
316 spin_unlock_bh(&srv->idr_lock);
317
318 if (connected(con))
319 tipc_conn_send_to_sock(con);
320
321 out:
322 conn_put(con);
323 }
324
325 /* tipc_topsrv_queue_evt() - interrupt level call from a subscription instance
326 * The queued work is launched into tipc_conn_send_work()->tipc_conn_send_to_sock()
327 */
tipc_topsrv_queue_evt(struct net * net,int conid,u32 event,struct tipc_event * evt)328 void tipc_topsrv_queue_evt(struct net *net, int conid,
329 u32 event, struct tipc_event *evt)
330 {
331 struct tipc_topsrv *srv = tipc_topsrv(net);
332 struct outqueue_entry *e;
333 struct tipc_conn *con;
334
335 con = tipc_conn_lookup(srv, conid);
336 if (!con)
337 return;
338
339 if (!connected(con))
340 goto err;
341
342 e = kmalloc_obj(*e, GFP_ATOMIC);
343 if (!e)
344 goto err;
345 e->inactive = (event == TIPC_SUBSCR_TIMEOUT);
346 memcpy(&e->evt, evt, sizeof(*evt));
347 spin_lock_bh(&con->outqueue_lock);
348 list_add_tail(&e->list, &con->outqueue);
349 spin_unlock_bh(&con->outqueue_lock);
350
351 spin_lock_bh(&srv->idr_lock);
352 if (srv->listener) {
353 if (queue_work(srv->send_wq, &con->swork)) {
354 spin_unlock_bh(&srv->idr_lock);
355 return;
356 }
357 }
358 spin_unlock_bh(&srv->idr_lock);
359 err:
360 conn_put(con);
361 }
362
363 /* tipc_conn_write_space - interrupt callback after a sendmsg EAGAIN
364 * Indicates that there now is more space in the send buffer
365 * The queued work is launched into tipc_send_work()->tipc_conn_send_to_sock()
366 */
tipc_conn_write_space(struct sock * sk)367 static void tipc_conn_write_space(struct sock *sk)
368 {
369 struct tipc_topsrv *srv;
370 struct tipc_conn *con;
371
372 read_lock_bh(&sk->sk_callback_lock);
373 con = sk->sk_user_data;
374 if (connected(con)) {
375 srv = con->server;
376 spin_lock_bh(&srv->idr_lock);
377 if (srv->listener) {
378 conn_get(con);
379 if (!queue_work(srv->send_wq, &con->swork))
380 conn_put(con);
381 }
382 spin_unlock_bh(&srv->idr_lock);
383 }
384 read_unlock_bh(&sk->sk_callback_lock);
385 }
386
tipc_conn_rcv_sub(struct tipc_topsrv * srv,struct tipc_conn * con,struct tipc_subscr * s)387 static int tipc_conn_rcv_sub(struct tipc_topsrv *srv,
388 struct tipc_conn *con,
389 struct tipc_subscr *s)
390 {
391 struct tipc_net *tn = tipc_net(srv->net);
392 struct tipc_subscription *sub;
393 u32 s_filter = tipc_sub_read(s, filter);
394
395 if (s_filter & TIPC_SUB_CANCEL) {
396 tipc_sub_write(s, filter, s_filter & ~TIPC_SUB_CANCEL);
397 tipc_conn_delete_sub(con, s);
398 return 0;
399 }
400 if (atomic_read(&tn->subscription_count) >= TIPC_MAX_SUBSCR) {
401 pr_warn("Subscription rejected, max (%u)\n", TIPC_MAX_SUBSCR);
402 return -1;
403 }
404 sub = tipc_sub_subscribe(srv->net, s, con->conid);
405 if (!sub)
406 return -1;
407 atomic_inc(&tn->subscription_count);
408 spin_lock_bh(&con->sub_lock);
409 list_add(&sub->sub_list, &con->sub_list);
410 spin_unlock_bh(&con->sub_lock);
411 return 0;
412 }
413
tipc_conn_rcv_from_sock(struct tipc_conn * con)414 static int tipc_conn_rcv_from_sock(struct tipc_conn *con)
415 {
416 struct tipc_topsrv *srv = con->server;
417 struct sock *sk = con->sock->sk;
418 struct msghdr msg = {};
419 struct tipc_subscr s;
420 struct kvec iov;
421 int ret;
422
423 iov.iov_base = &s;
424 iov.iov_len = sizeof(s);
425 msg.msg_name = NULL;
426 iov_iter_kvec(&msg.msg_iter, ITER_DEST, &iov, 1, iov.iov_len);
427 ret = sock_recvmsg(con->sock, &msg, MSG_DONTWAIT);
428 if (ret == -EWOULDBLOCK)
429 return -EWOULDBLOCK;
430 if (ret == sizeof(s)) {
431 read_lock_bh(&sk->sk_callback_lock);
432 /* RACE: the connection can be closed in the meantime */
433 if (likely(connected(con)))
434 ret = tipc_conn_rcv_sub(srv, con, &s);
435 read_unlock_bh(&sk->sk_callback_lock);
436 if (!ret)
437 return 0;
438 }
439
440 tipc_conn_close(con);
441 return ret;
442 }
443
tipc_conn_recv_work(struct work_struct * work)444 static void tipc_conn_recv_work(struct work_struct *work)
445 {
446 struct tipc_conn *con = container_of(work, struct tipc_conn, rwork);
447 struct tipc_topsrv *srv;
448 int count = 0;
449
450 srv = con->server;
451 spin_lock_bh(&srv->idr_lock);
452 if (!srv->listener) {
453 spin_unlock_bh(&srv->idr_lock);
454 goto out;
455 }
456 spin_unlock_bh(&srv->idr_lock);
457
458 while (connected(con)) {
459 if (tipc_conn_rcv_from_sock(con))
460 break;
461
462 /* Don't flood Rx machine */
463 if (++count >= MAX_RECV_MSG_COUNT) {
464 cond_resched();
465 count = 0;
466 }
467 }
468 out:
469 conn_put(con);
470 }
471
472 /* tipc_conn_data_ready - interrupt callback indicating the socket has data
473 * The queued work is launched into tipc_recv_work()->tipc_conn_rcv_from_sock()
474 */
tipc_conn_data_ready(struct sock * sk)475 static void tipc_conn_data_ready(struct sock *sk)
476 {
477 struct tipc_topsrv *srv;
478 struct tipc_conn *con;
479
480 trace_sk_data_ready(sk);
481
482 read_lock_bh(&sk->sk_callback_lock);
483 con = sk->sk_user_data;
484 if (connected(con)) {
485 srv = con->server;
486 spin_lock_bh(&srv->idr_lock);
487 if (srv->listener) {
488 conn_get(con);
489 if (!queue_work(srv->rcv_wq, &con->rwork))
490 conn_put(con);
491 }
492 spin_unlock_bh(&srv->idr_lock);
493 }
494 read_unlock_bh(&sk->sk_callback_lock);
495 }
496
tipc_topsrv_accept(struct work_struct * work)497 static void tipc_topsrv_accept(struct work_struct *work)
498 {
499 struct tipc_topsrv *srv = container_of(work, struct tipc_topsrv, awork);
500 struct socket *newsock, *lsock;
501 struct tipc_conn *con;
502 struct sock *newsk;
503 int ret;
504
505 spin_lock_bh(&srv->idr_lock);
506 if (!srv->listener) {
507 spin_unlock_bh(&srv->idr_lock);
508 return;
509 }
510 lsock = srv->listener;
511 spin_unlock_bh(&srv->idr_lock);
512
513 while (1) {
514 ret = kernel_accept(lsock, &newsock, O_NONBLOCK);
515 if (ret < 0)
516 return;
517 con = tipc_conn_alloc(srv, newsock);
518 if (IS_ERR(con)) {
519 ret = PTR_ERR(con);
520 sock_release(newsock);
521 return;
522 }
523 /* Register callbacks */
524 newsk = newsock->sk;
525 write_lock_bh(&newsk->sk_callback_lock);
526 newsk->sk_data_ready = tipc_conn_data_ready;
527 newsk->sk_write_space = tipc_conn_write_space;
528 newsk->sk_user_data = con;
529 write_unlock_bh(&newsk->sk_callback_lock);
530
531 /* Wake up receive process in case of 'SYN+' message */
532 newsk->sk_data_ready(newsk);
533 conn_put(con);
534 }
535 }
536
537 /* tipc_topsrv_listener_data_ready - interrupt callback with connection request
538 * The queued job is launched into tipc_topsrv_accept()
539 */
tipc_topsrv_listener_data_ready(struct sock * sk)540 static void tipc_topsrv_listener_data_ready(struct sock *sk)
541 {
542 struct tipc_topsrv *srv;
543
544 trace_sk_data_ready(sk);
545
546 read_lock_bh(&sk->sk_callback_lock);
547 srv = sk->sk_user_data;
548 if (srv) {
549 spin_lock_bh(&srv->idr_lock);
550 if (srv->listener)
551 queue_work(srv->rcv_wq, &srv->awork);
552 spin_unlock_bh(&srv->idr_lock);
553 }
554 read_unlock_bh(&sk->sk_callback_lock);
555 }
556
tipc_topsrv_create_listener(struct tipc_topsrv * srv)557 static int tipc_topsrv_create_listener(struct tipc_topsrv *srv)
558 {
559 struct socket *lsock = NULL;
560 struct sockaddr_tipc saddr;
561 struct sock *sk;
562 int rc;
563
564 rc = sock_create_kern(srv->net, AF_TIPC, SOCK_SEQPACKET, 0, &lsock);
565 if (rc < 0)
566 return rc;
567
568 srv->listener = lsock;
569 sk = lsock->sk;
570 write_lock_bh(&sk->sk_callback_lock);
571 sk->sk_data_ready = tipc_topsrv_listener_data_ready;
572 sk->sk_user_data = srv;
573 write_unlock_bh(&sk->sk_callback_lock);
574
575 lock_sock(sk);
576 rc = tsk_set_importance(sk, TIPC_CRITICAL_IMPORTANCE);
577 release_sock(sk);
578 if (rc < 0)
579 goto err;
580
581 saddr.family = AF_TIPC;
582 saddr.addrtype = TIPC_SERVICE_RANGE;
583 saddr.addr.nameseq.type = TIPC_TOP_SRV;
584 saddr.addr.nameseq.lower = TIPC_TOP_SRV;
585 saddr.addr.nameseq.upper = TIPC_TOP_SRV;
586 saddr.scope = TIPC_NODE_SCOPE;
587
588 rc = tipc_sk_bind(lsock, (struct sockaddr *)&saddr, sizeof(saddr));
589 if (rc < 0)
590 goto err;
591 rc = kernel_listen(lsock, 0);
592 if (rc < 0)
593 goto err;
594
595 /* As server's listening socket owner and creator is the same module,
596 * we have to decrease TIPC module reference count to guarantee that
597 * it remains zero after the server socket is created, otherwise,
598 * executing "rmmod" command is unable to make TIPC module deleted
599 * after TIPC module is inserted successfully.
600 *
601 * However, the reference count is ever increased twice in
602 * sock_create_kern(): one is to increase the reference count of owner
603 * of TIPC socket's proto_ops struct; another is to increment the
604 * reference count of owner of TIPC proto struct. Therefore, we must
605 * decrement the module reference count twice to ensure that it keeps
606 * zero after server's listening socket is created. Of course, we
607 * must bump the module reference count twice as well before the socket
608 * is closed.
609 */
610 module_put(lsock->ops->owner);
611 module_put(sk->sk_prot_creator->owner);
612
613 return 0;
614 err:
615 sock_release(lsock);
616 return -EINVAL;
617 }
618
tipc_topsrv_kern_subscr(struct net * net,u32 port,u32 type,u32 lower,u32 upper,u32 filter,int * conid)619 bool tipc_topsrv_kern_subscr(struct net *net, u32 port, u32 type, u32 lower,
620 u32 upper, u32 filter, int *conid)
621 {
622 struct tipc_subscr sub;
623 struct tipc_conn *con;
624 int rc;
625
626 sub.seq.type = type;
627 sub.seq.lower = lower;
628 sub.seq.upper = upper;
629 sub.timeout = TIPC_WAIT_FOREVER;
630 sub.filter = filter;
631 *(u64 *)&sub.usr_handle = (u64)port;
632
633 con = tipc_conn_alloc(tipc_topsrv(net), NULL);
634 if (IS_ERR(con))
635 return false;
636
637 *conid = con->conid;
638 rc = tipc_conn_rcv_sub(tipc_topsrv(net), con, &sub);
639 if (rc)
640 conn_put(con);
641
642 conn_put(con);
643 return !rc;
644 }
645
tipc_topsrv_kern_unsubscr(struct net * net,int conid)646 void tipc_topsrv_kern_unsubscr(struct net *net, int conid)
647 {
648 struct tipc_conn *con;
649
650 con = tipc_conn_lookup(tipc_topsrv(net), conid);
651 if (!con)
652 return;
653
654 test_and_clear_bit(CF_CONNECTED, &con->flags);
655 tipc_conn_delete_sub(con, NULL);
656 conn_put(con);
657 conn_put(con);
658 }
659
tipc_topsrv_kern_evt(struct net * net,struct tipc_event * evt)660 static void tipc_topsrv_kern_evt(struct net *net, struct tipc_event *evt)
661 {
662 u32 port = *(u32 *)&evt->s.usr_handle;
663 u32 self = tipc_own_addr(net);
664 struct sk_buff_head evtq;
665 struct sk_buff *skb;
666
667 skb = tipc_msg_create(TOP_SRV, 0, INT_H_SIZE, sizeof(*evt),
668 self, self, port, port, 0);
669 if (!skb)
670 return;
671 msg_set_dest_droppable(buf_msg(skb), true);
672 memcpy(msg_data(buf_msg(skb)), evt, sizeof(*evt));
673 skb_queue_head_init(&evtq);
674 __skb_queue_tail(&evtq, skb);
675 tipc_loopback_trace(net, &evtq);
676 tipc_sk_rcv(net, &evtq);
677 }
678
tipc_topsrv_work_start(struct tipc_topsrv * s)679 static int tipc_topsrv_work_start(struct tipc_topsrv *s)
680 {
681 s->rcv_wq = alloc_ordered_workqueue("tipc_rcv", 0);
682 if (!s->rcv_wq) {
683 pr_err("can't start tipc receive workqueue\n");
684 return -ENOMEM;
685 }
686
687 s->send_wq = alloc_ordered_workqueue("tipc_send", 0);
688 if (!s->send_wq) {
689 pr_err("can't start tipc send workqueue\n");
690 destroy_workqueue(s->rcv_wq);
691 return -ENOMEM;
692 }
693
694 return 0;
695 }
696
tipc_topsrv_work_stop(struct tipc_topsrv * s)697 static void tipc_topsrv_work_stop(struct tipc_topsrv *s)
698 {
699 destroy_workqueue(s->rcv_wq);
700 destroy_workqueue(s->send_wq);
701 }
702
tipc_topsrv_start(struct net * net)703 static int tipc_topsrv_start(struct net *net)
704 {
705 struct tipc_net *tn = tipc_net(net);
706 const char name[] = "topology_server";
707 struct tipc_topsrv *srv;
708 int ret;
709
710 srv = kzalloc_obj(*srv, GFP_ATOMIC);
711 if (!srv)
712 return -ENOMEM;
713
714 srv->net = net;
715 INIT_WORK(&srv->awork, tipc_topsrv_accept);
716
717 strscpy(srv->name, name, sizeof(srv->name));
718 tn->topsrv = srv;
719 atomic_set(&tn->subscription_count, 0);
720
721 spin_lock_init(&srv->idr_lock);
722 idr_init(&srv->conn_idr);
723 srv->idr_in_use = 0;
724
725 ret = tipc_topsrv_work_start(srv);
726 if (ret < 0)
727 goto err_start;
728
729 ret = tipc_topsrv_create_listener(srv);
730 if (ret < 0)
731 goto err_create;
732
733 return 0;
734
735 err_create:
736 tipc_topsrv_work_stop(srv);
737 err_start:
738 kfree(srv);
739 return ret;
740 }
741
tipc_topsrv_stop(struct net * net)742 static void tipc_topsrv_stop(struct net *net)
743 {
744 struct tipc_topsrv *srv = tipc_topsrv(net);
745 struct socket *lsock = srv->listener;
746 struct tipc_conn *con;
747 int id;
748
749 spin_lock_bh(&srv->idr_lock);
750 srv->listener = NULL;
751 spin_unlock_bh(&srv->idr_lock);
752 tipc_topsrv_work_stop(srv);
753
754 spin_lock_bh(&srv->idr_lock);
755 for (id = 0; srv->idr_in_use; id++) {
756 con = idr_find(&srv->conn_idr, id);
757 if (con) {
758 spin_unlock_bh(&srv->idr_lock);
759 tipc_conn_close(con);
760 spin_lock_bh(&srv->idr_lock);
761 continue;
762 }
763 spin_unlock_bh(&srv->idr_lock);
764 spin_lock_bh(&srv->idr_lock);
765 }
766 __module_get(lsock->ops->owner);
767 __module_get(lsock->sk->sk_prot_creator->owner);
768 spin_unlock_bh(&srv->idr_lock);
769
770 sock_release(lsock);
771 idr_destroy(&srv->conn_idr);
772 kfree(srv);
773 }
774
tipc_topsrv_init_net(struct net * net)775 int __net_init tipc_topsrv_init_net(struct net *net)
776 {
777 return tipc_topsrv_start(net);
778 }
779
tipc_topsrv_exit_net(struct net * net)780 void __net_exit tipc_topsrv_exit_net(struct net *net)
781 {
782 tipc_topsrv_stop(net);
783 }
784