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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#define CF_SERVER 2
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)
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 spin_unlock_bh(&s->idr_lock);
207
208 set_bit(CF_CONNECTED, &con->flags);
209 con->server = s;
210
211 return con;
212}
213
214static struct tipc_conn *tipc_conn_lookup(struct tipc_topsrv *s, int conid)
215{
216 struct tipc_conn *con;
217
218 spin_lock_bh(&s->idr_lock);
219 con = idr_find(&s->conn_idr, conid);
220 if (!connected(con) || !kref_get_unless_zero(&con->kref))
221 con = NULL;
222 spin_unlock_bh(&s->idr_lock);
223 return con;
224}
225
226/* tipc_conn_delete_sub - delete a specific or all subscriptions
227 * for a given subscriber
228 */
229static void tipc_conn_delete_sub(struct tipc_conn *con, struct tipc_subscr *s)
230{
231 struct tipc_net *tn = tipc_net(con->server->net);
232 struct list_head *sub_list = &con->sub_list;
233 struct tipc_subscription *sub, *tmp;
234
235 spin_lock_bh(&con->sub_lock);
236 list_for_each_entry_safe(sub, tmp, sub_list, sub_list) {
237 if (!s || !memcmp(s, &sub->evt.s, sizeof(*s))) {
238 tipc_sub_unsubscribe(sub);
239 atomic_dec(&tn->subscription_count);
240 if (s)
241 break;
242 }
243 }
244 spin_unlock_bh(&con->sub_lock);
245}
246
247static void tipc_conn_send_to_sock(struct tipc_conn *con)
248{
249 struct list_head *queue = &con->outqueue;
250 struct tipc_topsrv *srv = con->server;
251 struct outqueue_entry *e;
252 struct tipc_event *evt;
253 struct msghdr msg;
254 struct kvec iov;
255 int count = 0;
256 int ret;
257
258 spin_lock_bh(&con->outqueue_lock);
259
260 while (!list_empty(queue)) {
261 e = list_first_entry(queue, struct outqueue_entry, list);
262 evt = &e->evt;
263 spin_unlock_bh(&con->outqueue_lock);
264
265 if (e->inactive)
266 tipc_conn_delete_sub(con, &evt->s);
267
268 memset(&msg, 0, sizeof(msg));
269 msg.msg_flags = MSG_DONTWAIT;
270 iov.iov_base = evt;
271 iov.iov_len = sizeof(*evt);
272 msg.msg_name = NULL;
273
274 if (con->sock) {
275 ret = kernel_sendmsg(con->sock, &msg, &iov,
276 1, sizeof(*evt));
277 if (ret == -EWOULDBLOCK || ret == 0) {
278 cond_resched();
279 return;
280 } else if (ret < 0) {
281 return tipc_conn_close(con);
282 }
283 } else {
284 tipc_topsrv_kern_evt(srv->net, evt);
285 }
286
287 /* Don't starve users filling buffers */
288 if (++count >= MAX_SEND_MSG_COUNT) {
289 cond_resched();
290 count = 0;
291 }
292 spin_lock_bh(&con->outqueue_lock);
293 list_del(&e->list);
294 kfree(e);
295 }
296 spin_unlock_bh(&con->outqueue_lock);
297}
298
299static void tipc_conn_send_work(struct work_struct *work)
300{
301 struct tipc_conn *con = container_of(work, struct tipc_conn, swork);
302
303 if (connected(con))
304 tipc_conn_send_to_sock(con);
305
306 conn_put(con);
307}
308
309/* tipc_topsrv_queue_evt() - interrupt level call from a subscription instance
310 * The queued work is launched into tipc_conn_send_work()->tipc_conn_send_to_sock()
311 */
312void tipc_topsrv_queue_evt(struct net *net, int conid,
313 u32 event, struct tipc_event *evt)
314{
315 struct tipc_topsrv *srv = tipc_topsrv(net);
316 struct outqueue_entry *e;
317 struct tipc_conn *con;
318
319 con = tipc_conn_lookup(srv, conid);
320 if (!con)
321 return;
322
323 if (!connected(con))
324 goto err;
325
326 e = kmalloc(sizeof(*e), GFP_ATOMIC);
327 if (!e)
328 goto err;
329 e->inactive = (event == TIPC_SUBSCR_TIMEOUT);
330 memcpy(&e->evt, evt, sizeof(*evt));
331 spin_lock_bh(&con->outqueue_lock);
332 list_add_tail(&e->list, &con->outqueue);
333 spin_unlock_bh(&con->outqueue_lock);
334
335 if (queue_work(srv->send_wq, &con->swork))
336 return;
337err:
338 conn_put(con);
339}
340
341/* tipc_conn_write_space - interrupt callback after a sendmsg EAGAIN
342 * Indicates that there now is more space in the send buffer
343 * The queued work is launched into tipc_send_work()->tipc_conn_send_to_sock()
344 */
345static void tipc_conn_write_space(struct sock *sk)
346{
347 struct tipc_conn *con;
348
349 read_lock_bh(&sk->sk_callback_lock);
350 con = sk->sk_user_data;
351 if (connected(con)) {
352 conn_get(con);
353 if (!queue_work(con->server->send_wq, &con->swork))
354 conn_put(con);
355 }
356 read_unlock_bh(&sk->sk_callback_lock);
357}
358
359static int tipc_conn_rcv_sub(struct tipc_topsrv *srv,
360 struct tipc_conn *con,
361 struct tipc_subscr *s)
362{
363 struct tipc_net *tn = tipc_net(srv->net);
364 struct tipc_subscription *sub;
365 u32 s_filter = tipc_sub_read(s, filter);
366
367 if (s_filter & TIPC_SUB_CANCEL) {
368 tipc_sub_write(s, filter, s_filter & ~TIPC_SUB_CANCEL);
369 tipc_conn_delete_sub(con, s);
370 return 0;
371 }
372 if (atomic_read(&tn->subscription_count) >= TIPC_MAX_SUBSCR) {
373 pr_warn("Subscription rejected, max (%u)\n", TIPC_MAX_SUBSCR);
374 return -1;
375 }
376 sub = tipc_sub_subscribe(srv->net, s, con->conid);
377 if (!sub)
378 return -1;
379 atomic_inc(&tn->subscription_count);
380 spin_lock_bh(&con->sub_lock);
381 list_add(&sub->sub_list, &con->sub_list);
382 spin_unlock_bh(&con->sub_lock);
383 return 0;
384}
385
386static int tipc_conn_rcv_from_sock(struct tipc_conn *con)
387{
388 struct tipc_topsrv *srv = con->server;
389 struct sock *sk = con->sock->sk;
390 struct msghdr msg = {};
391 struct tipc_subscr s;
392 struct kvec iov;
393 int ret;
394
395 iov.iov_base = &s;
396 iov.iov_len = sizeof(s);
397 msg.msg_name = NULL;
398 iov_iter_kvec(&msg.msg_iter, READ, &iov, 1, iov.iov_len);
399 ret = sock_recvmsg(con->sock, &msg, MSG_DONTWAIT);
400 if (ret == -EWOULDBLOCK)
401 return -EWOULDBLOCK;
402 if (ret == sizeof(s)) {
403 read_lock_bh(&sk->sk_callback_lock);
404 /* RACE: the connection can be closed in the meantime */
405 if (likely(connected(con)))
406 ret = tipc_conn_rcv_sub(srv, con, &s);
407 read_unlock_bh(&sk->sk_callback_lock);
408 if (!ret)
409 return 0;
410 }
411
412 tipc_conn_close(con);
413 return ret;
414}
415
416static void tipc_conn_recv_work(struct work_struct *work)
417{
418 struct tipc_conn *con = container_of(work, struct tipc_conn, rwork);
419 int count = 0;
420
421 while (connected(con)) {
422 if (tipc_conn_rcv_from_sock(con))
423 break;
424
425 /* Don't flood Rx machine */
426 if (++count >= MAX_RECV_MSG_COUNT) {
427 cond_resched();
428 count = 0;
429 }
430 }
431 conn_put(con);
432}
433
434/* tipc_conn_data_ready - interrupt callback indicating the socket has data
435 * The queued work is launched into tipc_recv_work()->tipc_conn_rcv_from_sock()
436 */
437static void tipc_conn_data_ready(struct sock *sk)
438{
439 struct tipc_conn *con;
440
441 read_lock_bh(&sk->sk_callback_lock);
442 con = sk->sk_user_data;
443 if (connected(con)) {
444 conn_get(con);
445 if (!queue_work(con->server->rcv_wq, &con->rwork))
446 conn_put(con);
447 }
448 read_unlock_bh(&sk->sk_callback_lock);
449}
450
451static void tipc_topsrv_accept(struct work_struct *work)
452{
453 struct tipc_topsrv *srv = container_of(work, struct tipc_topsrv, awork);
454 struct socket *lsock = srv->listener;
455 struct socket *newsock;
456 struct tipc_conn *con;
457 struct sock *newsk;
458 int ret;
459
460 while (1) {
461 ret = kernel_accept(lsock, &newsock, O_NONBLOCK);
462 if (ret < 0)
463 return;
464 con = tipc_conn_alloc(srv);
465 if (IS_ERR(con)) {
466 ret = PTR_ERR(con);
467 sock_release(newsock);
468 return;
469 }
470 /* Register callbacks */
471 newsk = newsock->sk;
472 write_lock_bh(&newsk->sk_callback_lock);
473 newsk->sk_data_ready = tipc_conn_data_ready;
474 newsk->sk_write_space = tipc_conn_write_space;
475 newsk->sk_user_data = con;
476 con->sock = newsock;
477 write_unlock_bh(&newsk->sk_callback_lock);
478
479 /* Wake up receive process in case of 'SYN+' message */
480 newsk->sk_data_ready(newsk);
481 }
482}
483
484/* tipc_topsrv_listener_data_ready - interrupt callback with connection request
485 * The queued job is launched into tipc_topsrv_accept()
486 */
487static void tipc_topsrv_listener_data_ready(struct sock *sk)
488{
489 struct tipc_topsrv *srv;
490
491 read_lock_bh(&sk->sk_callback_lock);
492 srv = sk->sk_user_data;
493 if (srv->listener)
494 queue_work(srv->rcv_wq, &srv->awork);
495 read_unlock_bh(&sk->sk_callback_lock);
496}
497
498static int tipc_topsrv_create_listener(struct tipc_topsrv *srv)
499{
500 struct socket *lsock = NULL;
501 struct sockaddr_tipc saddr;
502 struct sock *sk;
503 int rc;
504
505 rc = sock_create_kern(srv->net, AF_TIPC, SOCK_SEQPACKET, 0, &lsock);
506 if (rc < 0)
507 return rc;
508
509 srv->listener = lsock;
510 sk = lsock->sk;
511 write_lock_bh(&sk->sk_callback_lock);
512 sk->sk_data_ready = tipc_topsrv_listener_data_ready;
513 sk->sk_user_data = srv;
514 write_unlock_bh(&sk->sk_callback_lock);
515
516 lock_sock(sk);
517 rc = tsk_set_importance(sk, TIPC_CRITICAL_IMPORTANCE);
518 release_sock(sk);
519 if (rc < 0)
520 goto err;
521
522 saddr.family = AF_TIPC;
523 saddr.addrtype = TIPC_ADDR_NAMESEQ;
524 saddr.addr.nameseq.type = TIPC_TOP_SRV;
525 saddr.addr.nameseq.lower = TIPC_TOP_SRV;
526 saddr.addr.nameseq.upper = TIPC_TOP_SRV;
527 saddr.scope = TIPC_NODE_SCOPE;
528
529 rc = kernel_bind(lsock, (struct sockaddr *)&saddr, sizeof(saddr));
530 if (rc < 0)
531 goto err;
532 rc = kernel_listen(lsock, 0);
533 if (rc < 0)
534 goto err;
535
536 /* As server's listening socket owner and creator is the same module,
537 * we have to decrease TIPC module reference count to guarantee that
538 * it remains zero after the server socket is created, otherwise,
539 * executing "rmmod" command is unable to make TIPC module deleted
540 * after TIPC module is inserted successfully.
541 *
542 * However, the reference count is ever increased twice in
543 * sock_create_kern(): one is to increase the reference count of owner
544 * of TIPC socket's proto_ops struct; another is to increment the
545 * reference count of owner of TIPC proto struct. Therefore, we must
546 * decrement the module reference count twice to ensure that it keeps
547 * zero after server's listening socket is created. Of course, we
548 * must bump the module reference count twice as well before the socket
549 * is closed.
550 */
551 module_put(lsock->ops->owner);
552 module_put(sk->sk_prot_creator->owner);
553
554 return 0;
555err:
556 sock_release(lsock);
557 return -EINVAL;
558}
559
560bool tipc_topsrv_kern_subscr(struct net *net, u32 port, u32 type, u32 lower,
561 u32 upper, u32 filter, int *conid)
562{
563 struct tipc_subscr sub;
564 struct tipc_conn *con;
565 int rc;
566
567 sub.seq.type = type;
568 sub.seq.lower = lower;
569 sub.seq.upper = upper;
570 sub.timeout = TIPC_WAIT_FOREVER;
571 sub.filter = filter;
572 *(u32 *)&sub.usr_handle = port;
573
574 con = tipc_conn_alloc(tipc_topsrv(net));
575 if (IS_ERR(con))
576 return false;
577
578 *conid = con->conid;
579 con->sock = NULL;
580 rc = tipc_conn_rcv_sub(tipc_topsrv(net), con, &sub);
581 if (rc >= 0)
582 return true;
583 conn_put(con);
584 return false;
585}
586
587void tipc_topsrv_kern_unsubscr(struct net *net, int conid)
588{
589 struct tipc_conn *con;
590
591 con = tipc_conn_lookup(tipc_topsrv(net), conid);
592 if (!con)
593 return;
594
595 test_and_clear_bit(CF_CONNECTED, &con->flags);
596 tipc_conn_delete_sub(con, NULL);
597 conn_put(con);
598 conn_put(con);
599}
600
601static void tipc_topsrv_kern_evt(struct net *net, struct tipc_event *evt)
602{
603 u32 port = *(u32 *)&evt->s.usr_handle;
604 u32 self = tipc_own_addr(net);
605 struct sk_buff_head evtq;
606 struct sk_buff *skb;
607
608 skb = tipc_msg_create(TOP_SRV, 0, INT_H_SIZE, sizeof(*evt),
609 self, self, port, port, 0);
610 if (!skb)
611 return;
612 msg_set_dest_droppable(buf_msg(skb), true);
613 memcpy(msg_data(buf_msg(skb)), evt, sizeof(*evt));
614 skb_queue_head_init(&evtq);
615 __skb_queue_tail(&evtq, skb);
616 tipc_loopback_trace(net, &evtq);
617 tipc_sk_rcv(net, &evtq);
618}
619
620static int tipc_topsrv_work_start(struct tipc_topsrv *s)
621{
622 s->rcv_wq = alloc_ordered_workqueue("tipc_rcv", 0);
623 if (!s->rcv_wq) {
624 pr_err("can't start tipc receive workqueue\n");
625 return -ENOMEM;
626 }
627
628 s->send_wq = alloc_ordered_workqueue("tipc_send", 0);
629 if (!s->send_wq) {
630 pr_err("can't start tipc send workqueue\n");
631 destroy_workqueue(s->rcv_wq);
632 return -ENOMEM;
633 }
634
635 return 0;
636}
637
638static void tipc_topsrv_work_stop(struct tipc_topsrv *s)
639{
640 destroy_workqueue(s->rcv_wq);
641 destroy_workqueue(s->send_wq);
642}
643
644static int tipc_topsrv_start(struct net *net)
645{
646 struct tipc_net *tn = tipc_net(net);
647 const char name[] = "topology_server";
648 struct tipc_topsrv *srv;
649 int ret;
650
651 srv = kzalloc(sizeof(*srv), GFP_ATOMIC);
652 if (!srv)
653 return -ENOMEM;
654
655 srv->net = net;
656 INIT_WORK(&srv->awork, tipc_topsrv_accept);
657
658 strscpy(srv->name, name, sizeof(srv->name));
659 tn->topsrv = srv;
660 atomic_set(&tn->subscription_count, 0);
661
662 spin_lock_init(&srv->idr_lock);
663 idr_init(&srv->conn_idr);
664 srv->idr_in_use = 0;
665
666 ret = tipc_topsrv_work_start(srv);
667 if (ret < 0)
668 return ret;
669
670 ret = tipc_topsrv_create_listener(srv);
671 if (ret < 0)
672 tipc_topsrv_work_stop(srv);
673
674 return ret;
675}
676
677static void tipc_topsrv_stop(struct net *net)
678{
679 struct tipc_topsrv *srv = tipc_topsrv(net);
680 struct socket *lsock = srv->listener;
681 struct tipc_conn *con;
682 int id;
683
684 spin_lock_bh(&srv->idr_lock);
685 for (id = 0; srv->idr_in_use; id++) {
686 con = idr_find(&srv->conn_idr, id);
687 if (con) {
688 spin_unlock_bh(&srv->idr_lock);
689 tipc_conn_close(con);
690 spin_lock_bh(&srv->idr_lock);
691 }
692 }
693 __module_get(lsock->ops->owner);
694 __module_get(lsock->sk->sk_prot_creator->owner);
695 srv->listener = NULL;
696 spin_unlock_bh(&srv->idr_lock);
697 sock_release(lsock);
698 tipc_topsrv_work_stop(srv);
699 idr_destroy(&srv->conn_idr);
700 kfree(srv);
701}
702
703int __net_init tipc_topsrv_init_net(struct net *net)
704{
705 return tipc_topsrv_start(net);
706}
707
708void __net_exit tipc_topsrv_exit_net(struct net *net)
709{
710 tipc_topsrv_stop(net);
711}
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}