1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* RxRPC individual remote procedure call handling
3  *
4  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
5  * Written by David Howells (dhowells@redhat.com)
6  */
7 
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9 
10 #include <linux/slab.h>
11 #include <linux/module.h>
12 #include <linux/circ_buf.h>
13 #include <linux/spinlock_types.h>
14 #include <net/sock.h>
15 #include <net/af_rxrpc.h>
16 #include "ar-internal.h"
17 
18 const char *const rxrpc_call_states[NR__RXRPC_CALL_STATES] = {
19 	[RXRPC_CALL_UNINITIALISED]		= "Uninit  ",
20 	[RXRPC_CALL_CLIENT_AWAIT_CONN]		= "ClWtConn",
21 	[RXRPC_CALL_CLIENT_SEND_REQUEST]	= "ClSndReq",
22 	[RXRPC_CALL_CLIENT_AWAIT_REPLY]		= "ClAwtRpl",
23 	[RXRPC_CALL_CLIENT_RECV_REPLY]		= "ClRcvRpl",
24 	[RXRPC_CALL_SERVER_PREALLOC]		= "SvPrealc",
25 	[RXRPC_CALL_SERVER_SECURING]		= "SvSecure",
26 	[RXRPC_CALL_SERVER_RECV_REQUEST]	= "SvRcvReq",
27 	[RXRPC_CALL_SERVER_ACK_REQUEST]		= "SvAckReq",
28 	[RXRPC_CALL_SERVER_SEND_REPLY]		= "SvSndRpl",
29 	[RXRPC_CALL_SERVER_AWAIT_ACK]		= "SvAwtACK",
30 	[RXRPC_CALL_COMPLETE]			= "Complete",
31 };
32 
33 const char *const rxrpc_call_completions[NR__RXRPC_CALL_COMPLETIONS] = {
34 	[RXRPC_CALL_SUCCEEDED]			= "Complete",
35 	[RXRPC_CALL_REMOTELY_ABORTED]		= "RmtAbort",
36 	[RXRPC_CALL_LOCALLY_ABORTED]		= "LocAbort",
37 	[RXRPC_CALL_LOCAL_ERROR]		= "LocError",
38 	[RXRPC_CALL_NETWORK_ERROR]		= "NetError",
39 };
40 
41 struct kmem_cache *rxrpc_call_jar;
42 
43 static struct semaphore rxrpc_call_limiter =
44 	__SEMAPHORE_INITIALIZER(rxrpc_call_limiter, 1000);
45 static struct semaphore rxrpc_kernel_call_limiter =
46 	__SEMAPHORE_INITIALIZER(rxrpc_kernel_call_limiter, 1000);
47 
rxrpc_call_timer_expired(struct timer_list * t)48 static void rxrpc_call_timer_expired(struct timer_list *t)
49 {
50 	struct rxrpc_call *call = from_timer(call, t, timer);
51 
52 	_enter("%d", call->debug_id);
53 
54 	if (call->state < RXRPC_CALL_COMPLETE) {
55 		trace_rxrpc_timer(call, rxrpc_timer_expired, jiffies);
56 		__rxrpc_queue_call(call);
57 	} else {
58 		rxrpc_put_call(call, rxrpc_call_put);
59 	}
60 }
61 
rxrpc_reduce_call_timer(struct rxrpc_call * call,unsigned long expire_at,unsigned long now,enum rxrpc_timer_trace why)62 void rxrpc_reduce_call_timer(struct rxrpc_call *call,
63 			     unsigned long expire_at,
64 			     unsigned long now,
65 			     enum rxrpc_timer_trace why)
66 {
67 	if (rxrpc_try_get_call(call, rxrpc_call_got_timer)) {
68 		trace_rxrpc_timer(call, why, now);
69 		if (timer_reduce(&call->timer, expire_at))
70 			rxrpc_put_call(call, rxrpc_call_put_notimer);
71 	}
72 }
73 
rxrpc_delete_call_timer(struct rxrpc_call * call)74 void rxrpc_delete_call_timer(struct rxrpc_call *call)
75 {
76 	if (del_timer_sync(&call->timer))
77 		rxrpc_put_call(call, rxrpc_call_put_timer);
78 }
79 
80 static struct lock_class_key rxrpc_call_user_mutex_lock_class_key;
81 
82 /*
83  * find an extant server call
84  * - called in process context with IRQs enabled
85  */
rxrpc_find_call_by_user_ID(struct rxrpc_sock * rx,unsigned long user_call_ID)86 struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx,
87 					      unsigned long user_call_ID)
88 {
89 	struct rxrpc_call *call;
90 	struct rb_node *p;
91 
92 	_enter("%p,%lx", rx, user_call_ID);
93 
94 	read_lock(&rx->call_lock);
95 
96 	p = rx->calls.rb_node;
97 	while (p) {
98 		call = rb_entry(p, struct rxrpc_call, sock_node);
99 
100 		if (user_call_ID < call->user_call_ID)
101 			p = p->rb_left;
102 		else if (user_call_ID > call->user_call_ID)
103 			p = p->rb_right;
104 		else
105 			goto found_extant_call;
106 	}
107 
108 	read_unlock(&rx->call_lock);
109 	_leave(" = NULL");
110 	return NULL;
111 
112 found_extant_call:
113 	rxrpc_get_call(call, rxrpc_call_got);
114 	read_unlock(&rx->call_lock);
115 	_leave(" = %p [%d]", call, refcount_read(&call->ref));
116 	return call;
117 }
118 
119 /*
120  * allocate a new call
121  */
rxrpc_alloc_call(struct rxrpc_sock * rx,gfp_t gfp,unsigned int debug_id)122 struct rxrpc_call *rxrpc_alloc_call(struct rxrpc_sock *rx, gfp_t gfp,
123 				    unsigned int debug_id)
124 {
125 	struct rxrpc_call *call;
126 	struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk));
127 
128 	call = kmem_cache_zalloc(rxrpc_call_jar, gfp);
129 	if (!call)
130 		return NULL;
131 
132 	call->rxtx_buffer = kcalloc(RXRPC_RXTX_BUFF_SIZE,
133 				    sizeof(struct sk_buff *),
134 				    gfp);
135 	if (!call->rxtx_buffer)
136 		goto nomem;
137 
138 	call->rxtx_annotations = kcalloc(RXRPC_RXTX_BUFF_SIZE, sizeof(u8), gfp);
139 	if (!call->rxtx_annotations)
140 		goto nomem_2;
141 
142 	mutex_init(&call->user_mutex);
143 
144 	/* Prevent lockdep reporting a deadlock false positive between the afs
145 	 * filesystem and sys_sendmsg() via the mmap sem.
146 	 */
147 	if (rx->sk.sk_kern_sock)
148 		lockdep_set_class(&call->user_mutex,
149 				  &rxrpc_call_user_mutex_lock_class_key);
150 
151 	timer_setup(&call->timer, rxrpc_call_timer_expired, 0);
152 	INIT_WORK(&call->processor, &rxrpc_process_call);
153 	INIT_LIST_HEAD(&call->link);
154 	INIT_LIST_HEAD(&call->chan_wait_link);
155 	INIT_LIST_HEAD(&call->accept_link);
156 	INIT_LIST_HEAD(&call->recvmsg_link);
157 	INIT_LIST_HEAD(&call->sock_link);
158 	init_waitqueue_head(&call->waitq);
159 	spin_lock_init(&call->lock);
160 	spin_lock_init(&call->notify_lock);
161 	spin_lock_init(&call->input_lock);
162 	rwlock_init(&call->state_lock);
163 	refcount_set(&call->ref, 1);
164 	call->debug_id = debug_id;
165 	call->tx_total_len = -1;
166 	call->next_rx_timo = 20 * HZ;
167 	call->next_req_timo = 1 * HZ;
168 
169 	memset(&call->sock_node, 0xed, sizeof(call->sock_node));
170 
171 	/* Leave space in the ring to handle a maxed-out jumbo packet */
172 	call->rx_winsize = rxrpc_rx_window_size;
173 	call->tx_winsize = 16;
174 	call->rx_expect_next = 1;
175 
176 	call->cong_cwnd = 2;
177 	call->cong_ssthresh = RXRPC_RXTX_BUFF_SIZE - 1;
178 
179 	call->rxnet = rxnet;
180 	call->rtt_avail = RXRPC_CALL_RTT_AVAIL_MASK;
181 	atomic_inc(&rxnet->nr_calls);
182 	return call;
183 
184 nomem_2:
185 	kfree(call->rxtx_buffer);
186 nomem:
187 	kmem_cache_free(rxrpc_call_jar, call);
188 	return NULL;
189 }
190 
191 /*
192  * Allocate a new client call.
193  */
rxrpc_alloc_client_call(struct rxrpc_sock * rx,struct sockaddr_rxrpc * srx,gfp_t gfp,unsigned int debug_id)194 static struct rxrpc_call *rxrpc_alloc_client_call(struct rxrpc_sock *rx,
195 						  struct sockaddr_rxrpc *srx,
196 						  gfp_t gfp,
197 						  unsigned int debug_id)
198 {
199 	struct rxrpc_call *call;
200 	ktime_t now;
201 
202 	_enter("");
203 
204 	call = rxrpc_alloc_call(rx, gfp, debug_id);
205 	if (!call)
206 		return ERR_PTR(-ENOMEM);
207 	call->state = RXRPC_CALL_CLIENT_AWAIT_CONN;
208 	call->service_id = srx->srx_service;
209 	call->tx_phase = true;
210 	now = ktime_get_real();
211 	call->acks_latest_ts = now;
212 	call->cong_tstamp = now;
213 
214 	_leave(" = %p", call);
215 	return call;
216 }
217 
218 /*
219  * Initiate the call ack/resend/expiry timer.
220  */
rxrpc_start_call_timer(struct rxrpc_call * call)221 static void rxrpc_start_call_timer(struct rxrpc_call *call)
222 {
223 	unsigned long now = jiffies;
224 	unsigned long j = now + MAX_JIFFY_OFFSET;
225 
226 	call->ack_at = j;
227 	call->ack_lost_at = j;
228 	call->resend_at = j;
229 	call->ping_at = j;
230 	call->expect_rx_by = j;
231 	call->expect_req_by = j;
232 	call->expect_term_by = j;
233 	call->timer.expires = now;
234 }
235 
236 /*
237  * Wait for a call slot to become available.
238  */
rxrpc_get_call_slot(struct rxrpc_call_params * p,gfp_t gfp)239 static struct semaphore *rxrpc_get_call_slot(struct rxrpc_call_params *p, gfp_t gfp)
240 {
241 	struct semaphore *limiter = &rxrpc_call_limiter;
242 
243 	if (p->kernel)
244 		limiter = &rxrpc_kernel_call_limiter;
245 	if (p->interruptibility == RXRPC_UNINTERRUPTIBLE) {
246 		down(limiter);
247 		return limiter;
248 	}
249 	return down_interruptible(limiter) < 0 ? NULL : limiter;
250 }
251 
252 /*
253  * Release a call slot.
254  */
rxrpc_put_call_slot(struct rxrpc_call * call)255 static void rxrpc_put_call_slot(struct rxrpc_call *call)
256 {
257 	struct semaphore *limiter = &rxrpc_call_limiter;
258 
259 	if (test_bit(RXRPC_CALL_KERNEL, &call->flags))
260 		limiter = &rxrpc_kernel_call_limiter;
261 	up(limiter);
262 }
263 
264 /*
265  * Set up a call for the given parameters.
266  * - Called with the socket lock held, which it must release.
267  * - If it returns a call, the call's lock will need releasing by the caller.
268  */
rxrpc_new_client_call(struct rxrpc_sock * rx,struct rxrpc_conn_parameters * cp,struct sockaddr_rxrpc * srx,struct rxrpc_call_params * p,gfp_t gfp,unsigned int debug_id)269 struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
270 					 struct rxrpc_conn_parameters *cp,
271 					 struct sockaddr_rxrpc *srx,
272 					 struct rxrpc_call_params *p,
273 					 gfp_t gfp,
274 					 unsigned int debug_id)
275 	__releases(&rx->sk.sk_lock.slock)
276 	__acquires(&call->user_mutex)
277 {
278 	struct rxrpc_call *call, *xcall;
279 	struct rxrpc_net *rxnet;
280 	struct semaphore *limiter;
281 	struct rb_node *parent, **pp;
282 	const void *here = __builtin_return_address(0);
283 	int ret;
284 
285 	_enter("%p,%lx", rx, p->user_call_ID);
286 
287 	limiter = rxrpc_get_call_slot(p, gfp);
288 	if (!limiter) {
289 		release_sock(&rx->sk);
290 		return ERR_PTR(-ERESTARTSYS);
291 	}
292 
293 	call = rxrpc_alloc_client_call(rx, srx, gfp, debug_id);
294 	if (IS_ERR(call)) {
295 		release_sock(&rx->sk);
296 		up(limiter);
297 		_leave(" = %ld", PTR_ERR(call));
298 		return call;
299 	}
300 
301 	call->interruptibility = p->interruptibility;
302 	call->tx_total_len = p->tx_total_len;
303 	trace_rxrpc_call(call->debug_id, rxrpc_call_new_client,
304 			 refcount_read(&call->ref),
305 			 here, (const void *)p->user_call_ID);
306 	if (p->kernel)
307 		__set_bit(RXRPC_CALL_KERNEL, &call->flags);
308 
309 	/* We need to protect a partially set up call against the user as we
310 	 * will be acting outside the socket lock.
311 	 */
312 	mutex_lock(&call->user_mutex);
313 
314 	/* Publish the call, even though it is incompletely set up as yet */
315 	write_lock(&rx->call_lock);
316 
317 	pp = &rx->calls.rb_node;
318 	parent = NULL;
319 	while (*pp) {
320 		parent = *pp;
321 		xcall = rb_entry(parent, struct rxrpc_call, sock_node);
322 
323 		if (p->user_call_ID < xcall->user_call_ID)
324 			pp = &(*pp)->rb_left;
325 		else if (p->user_call_ID > xcall->user_call_ID)
326 			pp = &(*pp)->rb_right;
327 		else
328 			goto error_dup_user_ID;
329 	}
330 
331 	rcu_assign_pointer(call->socket, rx);
332 	call->user_call_ID = p->user_call_ID;
333 	__set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
334 	rxrpc_get_call(call, rxrpc_call_got_userid);
335 	rb_link_node(&call->sock_node, parent, pp);
336 	rb_insert_color(&call->sock_node, &rx->calls);
337 	list_add(&call->sock_link, &rx->sock_calls);
338 
339 	write_unlock(&rx->call_lock);
340 
341 	rxnet = call->rxnet;
342 	spin_lock_bh(&rxnet->call_lock);
343 	list_add_tail_rcu(&call->link, &rxnet->calls);
344 	spin_unlock_bh(&rxnet->call_lock);
345 
346 	/* From this point on, the call is protected by its own lock. */
347 	release_sock(&rx->sk);
348 
349 	/* Set up or get a connection record and set the protocol parameters,
350 	 * including channel number and call ID.
351 	 */
352 	ret = rxrpc_connect_call(rx, call, cp, srx, gfp);
353 	if (ret < 0)
354 		goto error_attached_to_socket;
355 
356 	trace_rxrpc_call(call->debug_id, rxrpc_call_connected,
357 			 refcount_read(&call->ref), here, NULL);
358 
359 	rxrpc_start_call_timer(call);
360 
361 	_net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id);
362 
363 	_leave(" = %p [new]", call);
364 	return call;
365 
366 	/* We unexpectedly found the user ID in the list after taking
367 	 * the call_lock.  This shouldn't happen unless the user races
368 	 * with itself and tries to add the same user ID twice at the
369 	 * same time in different threads.
370 	 */
371 error_dup_user_ID:
372 	write_unlock(&rx->call_lock);
373 	release_sock(&rx->sk);
374 	__rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
375 				    RX_CALL_DEAD, -EEXIST);
376 	trace_rxrpc_call(call->debug_id, rxrpc_call_error,
377 			 refcount_read(&call->ref), here, ERR_PTR(-EEXIST));
378 	rxrpc_release_call(rx, call);
379 	mutex_unlock(&call->user_mutex);
380 	rxrpc_put_call(call, rxrpc_call_put);
381 	_leave(" = -EEXIST");
382 	return ERR_PTR(-EEXIST);
383 
384 	/* We got an error, but the call is attached to the socket and is in
385 	 * need of release.  However, we might now race with recvmsg() when
386 	 * completing the call queues it.  Return 0 from sys_sendmsg() and
387 	 * leave the error to recvmsg() to deal with.
388 	 */
389 error_attached_to_socket:
390 	trace_rxrpc_call(call->debug_id, rxrpc_call_error,
391 			 refcount_read(&call->ref), here, ERR_PTR(ret));
392 	set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
393 	__rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
394 				    RX_CALL_DEAD, ret);
395 	_leave(" = c=%08x [err]", call->debug_id);
396 	return call;
397 }
398 
399 /*
400  * Set up an incoming call.  call->conn points to the connection.
401  * This is called in BH context and isn't allowed to fail.
402  */
rxrpc_incoming_call(struct rxrpc_sock * rx,struct rxrpc_call * call,struct sk_buff * skb)403 void rxrpc_incoming_call(struct rxrpc_sock *rx,
404 			 struct rxrpc_call *call,
405 			 struct sk_buff *skb)
406 {
407 	struct rxrpc_connection *conn = call->conn;
408 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
409 	u32 chan;
410 
411 	_enter(",%d", call->conn->debug_id);
412 
413 	rcu_assign_pointer(call->socket, rx);
414 	call->call_id		= sp->hdr.callNumber;
415 	call->service_id	= sp->hdr.serviceId;
416 	call->cid		= sp->hdr.cid;
417 	call->state		= RXRPC_CALL_SERVER_SECURING;
418 	call->cong_tstamp	= skb->tstamp;
419 
420 	/* Set the channel for this call.  We don't get channel_lock as we're
421 	 * only defending against the data_ready handler (which we're called
422 	 * from) and the RESPONSE packet parser (which is only really
423 	 * interested in call_counter and can cope with a disagreement with the
424 	 * call pointer).
425 	 */
426 	chan = sp->hdr.cid & RXRPC_CHANNELMASK;
427 	conn->channels[chan].call_counter = call->call_id;
428 	conn->channels[chan].call_id = call->call_id;
429 	rcu_assign_pointer(conn->channels[chan].call, call);
430 
431 	spin_lock(&conn->params.peer->lock);
432 	hlist_add_head_rcu(&call->error_link, &conn->params.peer->error_targets);
433 	spin_unlock(&conn->params.peer->lock);
434 
435 	_net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id);
436 
437 	rxrpc_start_call_timer(call);
438 	_leave("");
439 }
440 
441 /*
442  * Queue a call's work processor, getting a ref to pass to the work queue.
443  */
rxrpc_queue_call(struct rxrpc_call * call)444 bool rxrpc_queue_call(struct rxrpc_call *call)
445 {
446 	const void *here = __builtin_return_address(0);
447 	int n;
448 
449 	if (!__refcount_inc_not_zero(&call->ref, &n))
450 		return false;
451 	if (rxrpc_queue_work(&call->processor))
452 		trace_rxrpc_call(call->debug_id, rxrpc_call_queued, n + 1,
453 				 here, NULL);
454 	else
455 		rxrpc_put_call(call, rxrpc_call_put_noqueue);
456 	return true;
457 }
458 
459 /*
460  * Queue a call's work processor, passing the callers ref to the work queue.
461  */
__rxrpc_queue_call(struct rxrpc_call * call)462 bool __rxrpc_queue_call(struct rxrpc_call *call)
463 {
464 	const void *here = __builtin_return_address(0);
465 	int n = refcount_read(&call->ref);
466 	ASSERTCMP(n, >=, 1);
467 	if (rxrpc_queue_work(&call->processor))
468 		trace_rxrpc_call(call->debug_id, rxrpc_call_queued_ref, n,
469 				 here, NULL);
470 	else
471 		rxrpc_put_call(call, rxrpc_call_put_noqueue);
472 	return true;
473 }
474 
475 /*
476  * Note the re-emergence of a call.
477  */
rxrpc_see_call(struct rxrpc_call * call)478 void rxrpc_see_call(struct rxrpc_call *call)
479 {
480 	const void *here = __builtin_return_address(0);
481 	if (call) {
482 		int n = refcount_read(&call->ref);
483 
484 		trace_rxrpc_call(call->debug_id, rxrpc_call_seen, n,
485 				 here, NULL);
486 	}
487 }
488 
rxrpc_try_get_call(struct rxrpc_call * call,enum rxrpc_call_trace op)489 bool rxrpc_try_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
490 {
491 	const void *here = __builtin_return_address(0);
492 	int n;
493 
494 	if (!__refcount_inc_not_zero(&call->ref, &n))
495 		return false;
496 	trace_rxrpc_call(call->debug_id, op, n + 1, here, NULL);
497 	return true;
498 }
499 
500 /*
501  * Note the addition of a ref on a call.
502  */
rxrpc_get_call(struct rxrpc_call * call,enum rxrpc_call_trace op)503 void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
504 {
505 	const void *here = __builtin_return_address(0);
506 	int n;
507 
508 	__refcount_inc(&call->ref, &n);
509 	trace_rxrpc_call(call->debug_id, op, n + 1, here, NULL);
510 }
511 
512 /*
513  * Clean up the RxTx skb ring.
514  */
rxrpc_cleanup_ring(struct rxrpc_call * call)515 static void rxrpc_cleanup_ring(struct rxrpc_call *call)
516 {
517 	int i;
518 
519 	for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) {
520 		rxrpc_free_skb(call->rxtx_buffer[i], rxrpc_skb_cleaned);
521 		call->rxtx_buffer[i] = NULL;
522 	}
523 }
524 
525 /*
526  * Detach a call from its owning socket.
527  */
rxrpc_release_call(struct rxrpc_sock * rx,struct rxrpc_call * call)528 void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
529 {
530 	const void *here = __builtin_return_address(0);
531 	struct rxrpc_connection *conn = call->conn;
532 	bool put = false;
533 
534 	_enter("{%d,%d}", call->debug_id, refcount_read(&call->ref));
535 
536 	trace_rxrpc_call(call->debug_id, rxrpc_call_release,
537 			 refcount_read(&call->ref),
538 			 here, (const void *)call->flags);
539 
540 	ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
541 
542 	spin_lock_bh(&call->lock);
543 	if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
544 		BUG();
545 	spin_unlock_bh(&call->lock);
546 
547 	rxrpc_put_call_slot(call);
548 	rxrpc_delete_call_timer(call);
549 
550 	/* Make sure we don't get any more notifications */
551 	write_lock_bh(&rx->recvmsg_lock);
552 
553 	if (!list_empty(&call->recvmsg_link)) {
554 		_debug("unlinking once-pending call %p { e=%lx f=%lx }",
555 		       call, call->events, call->flags);
556 		list_del(&call->recvmsg_link);
557 		put = true;
558 	}
559 
560 	/* list_empty() must return false in rxrpc_notify_socket() */
561 	call->recvmsg_link.next = NULL;
562 	call->recvmsg_link.prev = NULL;
563 
564 	write_unlock_bh(&rx->recvmsg_lock);
565 	if (put)
566 		rxrpc_put_call(call, rxrpc_call_put);
567 
568 	write_lock(&rx->call_lock);
569 
570 	if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
571 		rb_erase(&call->sock_node, &rx->calls);
572 		memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
573 		rxrpc_put_call(call, rxrpc_call_put_userid);
574 	}
575 
576 	list_del(&call->sock_link);
577 	write_unlock(&rx->call_lock);
578 
579 	_debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
580 
581 	if (conn && !test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
582 		rxrpc_disconnect_call(call);
583 	if (call->security)
584 		call->security->free_call_crypto(call);
585 	_leave("");
586 }
587 
588 /*
589  * release all the calls associated with a socket
590  */
rxrpc_release_calls_on_socket(struct rxrpc_sock * rx)591 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
592 {
593 	struct rxrpc_call *call;
594 
595 	_enter("%p", rx);
596 
597 	while (!list_empty(&rx->to_be_accepted)) {
598 		call = list_entry(rx->to_be_accepted.next,
599 				  struct rxrpc_call, accept_link);
600 		list_del(&call->accept_link);
601 		rxrpc_abort_call("SKR", call, 0, RX_CALL_DEAD, -ECONNRESET);
602 		rxrpc_put_call(call, rxrpc_call_put);
603 	}
604 
605 	while (!list_empty(&rx->sock_calls)) {
606 		call = list_entry(rx->sock_calls.next,
607 				  struct rxrpc_call, sock_link);
608 		rxrpc_get_call(call, rxrpc_call_got);
609 		rxrpc_abort_call("SKT", call, 0, RX_CALL_DEAD, -ECONNRESET);
610 		rxrpc_send_abort_packet(call);
611 		rxrpc_release_call(rx, call);
612 		rxrpc_put_call(call, rxrpc_call_put);
613 	}
614 
615 	_leave("");
616 }
617 
618 /*
619  * release a call
620  */
rxrpc_put_call(struct rxrpc_call * call,enum rxrpc_call_trace op)621 void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
622 {
623 	struct rxrpc_net *rxnet = call->rxnet;
624 	const void *here = __builtin_return_address(0);
625 	unsigned int debug_id = call->debug_id;
626 	bool dead;
627 	int n;
628 
629 	ASSERT(call != NULL);
630 
631 	dead = __refcount_dec_and_test(&call->ref, &n);
632 	trace_rxrpc_call(debug_id, op, n, here, NULL);
633 	if (dead) {
634 		_debug("call %d dead", call->debug_id);
635 		ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
636 
637 		if (!list_empty(&call->link)) {
638 			spin_lock_bh(&rxnet->call_lock);
639 			list_del_init(&call->link);
640 			spin_unlock_bh(&rxnet->call_lock);
641 		}
642 
643 		rxrpc_cleanup_call(call);
644 	}
645 }
646 
647 /*
648  * Final call destruction - but must be done in process context.
649  */
rxrpc_destroy_call(struct work_struct * work)650 static void rxrpc_destroy_call(struct work_struct *work)
651 {
652 	struct rxrpc_call *call = container_of(work, struct rxrpc_call, processor);
653 	struct rxrpc_net *rxnet = call->rxnet;
654 
655 	rxrpc_delete_call_timer(call);
656 
657 	rxrpc_put_connection(call->conn);
658 	rxrpc_put_peer(call->peer);
659 	kfree(call->rxtx_buffer);
660 	kfree(call->rxtx_annotations);
661 	kmem_cache_free(rxrpc_call_jar, call);
662 	if (atomic_dec_and_test(&rxnet->nr_calls))
663 		wake_up_var(&rxnet->nr_calls);
664 }
665 
666 /*
667  * Final call destruction under RCU.
668  */
rxrpc_rcu_destroy_call(struct rcu_head * rcu)669 static void rxrpc_rcu_destroy_call(struct rcu_head *rcu)
670 {
671 	struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
672 
673 	if (in_softirq()) {
674 		INIT_WORK(&call->processor, rxrpc_destroy_call);
675 		if (!rxrpc_queue_work(&call->processor))
676 			BUG();
677 	} else {
678 		rxrpc_destroy_call(&call->processor);
679 	}
680 }
681 
682 /*
683  * clean up a call
684  */
rxrpc_cleanup_call(struct rxrpc_call * call)685 void rxrpc_cleanup_call(struct rxrpc_call *call)
686 {
687 	_net("DESTROY CALL %d", call->debug_id);
688 
689 	memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
690 
691 	ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
692 	ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
693 
694 	rxrpc_cleanup_ring(call);
695 	rxrpc_free_skb(call->tx_pending, rxrpc_skb_cleaned);
696 
697 	call_rcu(&call->rcu, rxrpc_rcu_destroy_call);
698 }
699 
700 /*
701  * Make sure that all calls are gone from a network namespace.  To reach this
702  * point, any open UDP sockets in that namespace must have been closed, so any
703  * outstanding calls cannot be doing I/O.
704  */
rxrpc_destroy_all_calls(struct rxrpc_net * rxnet)705 void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet)
706 {
707 	struct rxrpc_call *call;
708 
709 	_enter("");
710 
711 	if (!list_empty(&rxnet->calls)) {
712 		spin_lock_bh(&rxnet->call_lock);
713 
714 		while (!list_empty(&rxnet->calls)) {
715 			call = list_entry(rxnet->calls.next,
716 					  struct rxrpc_call, link);
717 			_debug("Zapping call %p", call);
718 
719 			rxrpc_see_call(call);
720 			list_del_init(&call->link);
721 
722 			pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
723 			       call, refcount_read(&call->ref),
724 			       rxrpc_call_states[call->state],
725 			       call->flags, call->events);
726 
727 			spin_unlock_bh(&rxnet->call_lock);
728 			cond_resched();
729 			spin_lock_bh(&rxnet->call_lock);
730 		}
731 
732 		spin_unlock_bh(&rxnet->call_lock);
733 	}
734 
735 	atomic_dec(&rxnet->nr_calls);
736 	wait_var_event(&rxnet->nr_calls, !atomic_read(&rxnet->nr_calls));
737 }
738