2 * net/tipc/server.c: TIPC server infrastructure
4 * Copyright (c) 2012-2013, Wind River Systems
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8 * modification, are permitted provided that the following conditions are met:
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16 * contributors may be used to endorse or promote products derived from
17 * this software without specific prior written permission.
19 * Alternatively, this software may be distributed under the terms of the
20 * GNU General Public License ("GPL") version 2 as published by the Free
21 * Software Foundation.
23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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41 /* Number of messages to send before rescheduling */
42 #define MAX_SEND_MSG_COUNT 25
43 #define MAX_RECV_MSG_COUNT 25
44 #define CF_CONNECTED 1
46 #define sock2con(x) ((struct tipc_conn *)(x)->sk_user_data)
49 * struct tipc_conn - TIPC connection structure
50 * @kref: reference counter to connection object
51 * @conid: connection identifier
52 * @sock: socket handler associated with connection
53 * @flags: indicates connection state
54 * @server: pointer to connected server
55 * @rwork: receive work item
56 * @usr_data: user-specified field
57 * @rx_action: what to do when connection socket is active
58 * @outqueue: pointer to first outbound message in queue
59 * @outqueue_lock: control access to the outqueue
60 * @outqueue: list of connection objects for its server
61 * @swork: send work item
68 struct tipc_server *server;
69 struct work_struct rwork;
70 int (*rx_action) (struct tipc_conn *con);
72 struct list_head outqueue;
73 spinlock_t outqueue_lock;
74 struct work_struct swork;
77 /* An entry waiting to be sent */
78 struct outqueue_entry {
79 struct list_head list;
81 struct sockaddr_tipc dest;
84 static void tipc_recv_work(struct work_struct *work);
85 static void tipc_send_work(struct work_struct *work);
86 static void tipc_clean_outqueues(struct tipc_conn *con);
88 static void tipc_conn_kref_release(struct kref *kref)
90 struct tipc_conn *con = container_of(kref, struct tipc_conn, kref);
93 tipc_sock_release_local(con->sock);
97 tipc_clean_outqueues(con);
101 static void conn_put(struct tipc_conn *con)
103 kref_put(&con->kref, tipc_conn_kref_release);
106 static void conn_get(struct tipc_conn *con)
108 kref_get(&con->kref);
111 static struct tipc_conn *tipc_conn_lookup(struct tipc_server *s, int conid)
113 struct tipc_conn *con;
115 spin_lock_bh(&s->idr_lock);
116 con = idr_find(&s->conn_idr, conid);
119 spin_unlock_bh(&s->idr_lock);
123 static void sock_data_ready(struct sock *sk)
125 struct tipc_conn *con;
127 read_lock(&sk->sk_callback_lock);
129 if (con && test_bit(CF_CONNECTED, &con->flags)) {
131 if (!queue_work(con->server->rcv_wq, &con->rwork))
134 read_unlock(&sk->sk_callback_lock);
137 static void sock_write_space(struct sock *sk)
139 struct tipc_conn *con;
141 read_lock(&sk->sk_callback_lock);
143 if (con && test_bit(CF_CONNECTED, &con->flags)) {
145 if (!queue_work(con->server->send_wq, &con->swork))
148 read_unlock(&sk->sk_callback_lock);
151 static void tipc_register_callbacks(struct socket *sock, struct tipc_conn *con)
153 struct sock *sk = sock->sk;
155 write_lock_bh(&sk->sk_callback_lock);
157 sk->sk_data_ready = sock_data_ready;
158 sk->sk_write_space = sock_write_space;
159 sk->sk_user_data = con;
163 write_unlock_bh(&sk->sk_callback_lock);
166 static void tipc_unregister_callbacks(struct tipc_conn *con)
168 struct sock *sk = con->sock->sk;
170 write_lock_bh(&sk->sk_callback_lock);
171 sk->sk_user_data = NULL;
172 write_unlock_bh(&sk->sk_callback_lock);
175 static void tipc_close_conn(struct tipc_conn *con)
177 struct tipc_server *s = con->server;
179 if (test_and_clear_bit(CF_CONNECTED, &con->flags)) {
181 s->tipc_conn_shutdown(con->conid, con->usr_data);
183 spin_lock_bh(&s->idr_lock);
184 idr_remove(&s->conn_idr, con->conid);
186 spin_unlock_bh(&s->idr_lock);
188 tipc_unregister_callbacks(con);
190 /* We shouldn't flush pending works as we may be in the
191 * thread. In fact the races with pending rx/tx work structs
192 * are harmless for us here as we have already deleted this
193 * connection from server connection list and set
194 * sk->sk_user_data to 0 before releasing connection object.
196 kernel_sock_shutdown(con->sock, SHUT_RDWR);
202 static struct tipc_conn *tipc_alloc_conn(struct tipc_server *s)
204 struct tipc_conn *con;
207 con = kzalloc(sizeof(struct tipc_conn), GFP_ATOMIC);
209 return ERR_PTR(-ENOMEM);
211 kref_init(&con->kref);
212 INIT_LIST_HEAD(&con->outqueue);
213 spin_lock_init(&con->outqueue_lock);
214 INIT_WORK(&con->swork, tipc_send_work);
215 INIT_WORK(&con->rwork, tipc_recv_work);
217 spin_lock_bh(&s->idr_lock);
218 ret = idr_alloc(&s->conn_idr, con, 0, 0, GFP_ATOMIC);
221 spin_unlock_bh(&s->idr_lock);
222 return ERR_PTR(-ENOMEM);
226 spin_unlock_bh(&s->idr_lock);
228 set_bit(CF_CONNECTED, &con->flags);
234 static int tipc_receive_from_sock(struct tipc_conn *con)
236 struct msghdr msg = {};
237 struct tipc_server *s = con->server;
238 struct sockaddr_tipc addr;
243 buf = kmem_cache_alloc(s->rcvbuf_cache, GFP_ATOMIC);
250 iov.iov_len = s->max_rcvbuf_size;
251 msg.msg_name = &addr;
252 ret = kernel_recvmsg(con->sock, &msg, &iov, 1, iov.iov_len,
255 kmem_cache_free(s->rcvbuf_cache, buf);
259 s->tipc_conn_recvmsg(con->conid, &addr, con->usr_data, buf, ret);
261 kmem_cache_free(s->rcvbuf_cache, buf);
266 if (ret != -EWOULDBLOCK)
267 tipc_close_conn(con);
269 /* Don't return success if we really got EOF */
275 static int tipc_accept_from_sock(struct tipc_conn *con)
277 struct tipc_server *s = con->server;
278 struct socket *sock = con->sock;
279 struct socket *newsock;
280 struct tipc_conn *newcon;
283 ret = tipc_sock_accept_local(sock, &newsock, O_NONBLOCK);
287 newcon = tipc_alloc_conn(con->server);
288 if (IS_ERR(newcon)) {
289 ret = PTR_ERR(newcon);
290 sock_release(newsock);
294 newcon->rx_action = tipc_receive_from_sock;
295 tipc_register_callbacks(newsock, newcon);
297 /* Notify that new connection is incoming */
298 newcon->usr_data = s->tipc_conn_new(newcon->conid);
300 /* Wake up receive process in case of 'SYN+' message */
301 newsock->sk->sk_data_ready(newsock->sk);
305 static struct socket *tipc_create_listen_sock(struct tipc_conn *con)
307 struct tipc_server *s = con->server;
308 struct socket *sock = NULL;
311 ret = tipc_sock_create_local(s->type, &sock);
314 ret = kernel_setsockopt(sock, SOL_TIPC, TIPC_IMPORTANCE,
315 (char *)&s->imp, sizeof(s->imp));
318 ret = kernel_bind(sock, (struct sockaddr *)s->saddr, sizeof(*s->saddr));
325 con->rx_action = tipc_accept_from_sock;
327 ret = kernel_listen(sock, 0);
333 con->rx_action = tipc_receive_from_sock;
336 pr_err("Unknown socket type %d\n", s->type);
347 static int tipc_open_listening_sock(struct tipc_server *s)
350 struct tipc_conn *con;
352 con = tipc_alloc_conn(s);
356 sock = tipc_create_listen_sock(con);
358 idr_remove(&s->conn_idr, con->conid);
364 tipc_register_callbacks(sock, con);
368 static struct outqueue_entry *tipc_alloc_entry(void *data, int len)
370 struct outqueue_entry *entry;
373 entry = kmalloc(sizeof(struct outqueue_entry), GFP_ATOMIC);
377 buf = kmalloc(len, GFP_ATOMIC);
383 memcpy(buf, data, len);
384 entry->iov.iov_base = buf;
385 entry->iov.iov_len = len;
390 static void tipc_free_entry(struct outqueue_entry *e)
392 kfree(e->iov.iov_base);
396 static void tipc_clean_outqueues(struct tipc_conn *con)
398 struct outqueue_entry *e, *safe;
400 spin_lock_bh(&con->outqueue_lock);
401 list_for_each_entry_safe(e, safe, &con->outqueue, list) {
405 spin_unlock_bh(&con->outqueue_lock);
408 int tipc_conn_sendmsg(struct tipc_server *s, int conid,
409 struct sockaddr_tipc *addr, void *data, size_t len)
411 struct outqueue_entry *e;
412 struct tipc_conn *con;
414 con = tipc_conn_lookup(s, conid);
418 e = tipc_alloc_entry(data, len);
425 memcpy(&e->dest, addr, sizeof(struct sockaddr_tipc));
427 spin_lock_bh(&con->outqueue_lock);
428 list_add_tail(&e->list, &con->outqueue);
429 spin_unlock_bh(&con->outqueue_lock);
431 if (test_bit(CF_CONNECTED, &con->flags)) {
432 if (!queue_work(s->send_wq, &con->swork))
440 void tipc_conn_terminate(struct tipc_server *s, int conid)
442 struct tipc_conn *con;
444 con = tipc_conn_lookup(s, conid);
446 tipc_close_conn(con);
451 static void tipc_send_to_sock(struct tipc_conn *con)
454 struct tipc_server *s = con->server;
455 struct outqueue_entry *e;
459 spin_lock_bh(&con->outqueue_lock);
461 e = list_entry(con->outqueue.next, struct outqueue_entry,
463 if ((struct list_head *) e == &con->outqueue)
465 spin_unlock_bh(&con->outqueue_lock);
467 memset(&msg, 0, sizeof(msg));
468 msg.msg_flags = MSG_DONTWAIT;
470 if (s->type == SOCK_DGRAM || s->type == SOCK_RDM) {
471 msg.msg_name = &e->dest;
472 msg.msg_namelen = sizeof(struct sockaddr_tipc);
474 ret = kernel_sendmsg(con->sock, &msg, &e->iov, 1,
476 if (ret == -EWOULDBLOCK || ret == 0) {
479 } else if (ret < 0) {
483 /* Don't starve users filling buffers */
484 if (++count >= MAX_SEND_MSG_COUNT) {
489 spin_lock_bh(&con->outqueue_lock);
493 spin_unlock_bh(&con->outqueue_lock);
498 tipc_close_conn(con);
501 static void tipc_recv_work(struct work_struct *work)
503 struct tipc_conn *con = container_of(work, struct tipc_conn, rwork);
506 while (test_bit(CF_CONNECTED, &con->flags)) {
507 if (con->rx_action(con))
510 /* Don't flood Rx machine */
511 if (++count >= MAX_RECV_MSG_COUNT) {
519 static void tipc_send_work(struct work_struct *work)
521 struct tipc_conn *con = container_of(work, struct tipc_conn, swork);
523 if (test_bit(CF_CONNECTED, &con->flags))
524 tipc_send_to_sock(con);
529 static void tipc_work_stop(struct tipc_server *s)
531 destroy_workqueue(s->rcv_wq);
532 destroy_workqueue(s->send_wq);
535 static int tipc_work_start(struct tipc_server *s)
537 s->rcv_wq = alloc_workqueue("tipc_rcv", WQ_UNBOUND, 1);
539 pr_err("can't start tipc receive workqueue\n");
543 s->send_wq = alloc_workqueue("tipc_send", WQ_UNBOUND, 1);
545 pr_err("can't start tipc send workqueue\n");
546 destroy_workqueue(s->rcv_wq);
553 int tipc_server_start(struct tipc_server *s)
557 spin_lock_init(&s->idr_lock);
558 idr_init(&s->conn_idr);
561 s->rcvbuf_cache = kmem_cache_create(s->name, s->max_rcvbuf_size,
562 0, SLAB_HWCACHE_ALIGN, NULL);
563 if (!s->rcvbuf_cache)
566 ret = tipc_work_start(s);
568 kmem_cache_destroy(s->rcvbuf_cache);
571 ret = tipc_open_listening_sock(s);
574 kmem_cache_destroy(s->rcvbuf_cache);
580 void tipc_server_stop(struct tipc_server *s)
582 struct tipc_conn *con;
586 spin_lock_bh(&s->idr_lock);
587 for (id = 0; total < s->idr_in_use; id++) {
588 con = idr_find(&s->conn_idr, id);
591 spin_unlock_bh(&s->idr_lock);
592 tipc_close_conn(con);
593 spin_lock_bh(&s->idr_lock);
596 spin_unlock_bh(&s->idr_lock);
599 kmem_cache_destroy(s->rcvbuf_cache);
600 idr_destroy(&s->conn_idr);