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