xref: /linux/net/rxrpc/call_object.c (revision 68993ced0f618e36cf33388f1e50223e5e6e78cc)
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_RECV_REQUEST]	= "SvRcvReq",
26 	[RXRPC_CALL_SERVER_ACK_REQUEST]		= "SvAckReq",
27 	[RXRPC_CALL_SERVER_SEND_REPLY]		= "SvSndRpl",
28 	[RXRPC_CALL_SERVER_AWAIT_ACK]		= "SvAwtACK",
29 	[RXRPC_CALL_COMPLETE]			= "Complete",
30 };
31 
32 const char *const rxrpc_call_completions[NR__RXRPC_CALL_COMPLETIONS] = {
33 	[RXRPC_CALL_SUCCEEDED]			= "Complete",
34 	[RXRPC_CALL_REMOTELY_ABORTED]		= "RmtAbort",
35 	[RXRPC_CALL_LOCALLY_ABORTED]		= "LocAbort",
36 	[RXRPC_CALL_LOCAL_ERROR]		= "LocError",
37 	[RXRPC_CALL_NETWORK_ERROR]		= "NetError",
38 };
39 
40 struct kmem_cache *rxrpc_call_jar;
41 
42 static DEFINE_SEMAPHORE(rxrpc_call_limiter, 1000);
43 static DEFINE_SEMAPHORE(rxrpc_kernel_call_limiter, 1000);
44 
rxrpc_poke_call(struct rxrpc_call * call,enum rxrpc_call_poke_trace what)45 void rxrpc_poke_call(struct rxrpc_call *call, enum rxrpc_call_poke_trace what)
46 {
47 	struct rxrpc_local *local = call->local;
48 	bool busy;
49 
50 	if (!test_bit(RXRPC_CALL_DISCONNECTED, &call->flags)) {
51 		spin_lock_irq(&local->lock);
52 		busy = !list_empty(&call->attend_link);
53 		trace_rxrpc_poke_call(call, busy, what);
54 		if (!busy && !rxrpc_try_get_call(call, rxrpc_call_get_poke))
55 			busy = true;
56 		if (!busy) {
57 			list_add_tail(&call->attend_link, &local->call_attend_q);
58 		}
59 		spin_unlock_irq(&local->lock);
60 		if (!busy)
61 			rxrpc_wake_up_io_thread(local);
62 	}
63 }
64 
rxrpc_call_timer_expired(struct timer_list * t)65 static void rxrpc_call_timer_expired(struct timer_list *t)
66 {
67 	struct rxrpc_call *call = timer_container_of(call, t, timer);
68 
69 	_enter("%d", call->debug_id);
70 
71 	if (!__rxrpc_call_is_complete(call)) {
72 		trace_rxrpc_timer_expired(call);
73 		rxrpc_poke_call(call, rxrpc_call_poke_timer);
74 	}
75 }
76 
77 static struct lock_class_key rxrpc_call_user_mutex_lock_class_key;
78 
79 static void rxrpc_destroy_call(struct work_struct *);
80 
81 /*
82  * find an extant server call
83  * - called in process context with IRQs enabled
84  */
rxrpc_find_call_by_user_ID(struct rxrpc_sock * rx,unsigned long user_call_ID)85 struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx,
86 					      unsigned long user_call_ID)
87 {
88 	struct rxrpc_call *call;
89 	struct rb_node *p;
90 
91 	_enter("%p,%lx", rx, user_call_ID);
92 
93 	read_lock(&rx->call_lock);
94 
95 	p = rx->calls.rb_node;
96 	while (p) {
97 		call = rb_entry(p, struct rxrpc_call, sock_node);
98 
99 		if (user_call_ID < call->user_call_ID)
100 			p = p->rb_left;
101 		else if (user_call_ID > call->user_call_ID)
102 			p = p->rb_right;
103 		else
104 			goto found_extant_call;
105 	}
106 
107 	read_unlock(&rx->call_lock);
108 	_leave(" = NULL");
109 	return NULL;
110 
111 found_extant_call:
112 	rxrpc_get_call(call, rxrpc_call_get_sendmsg);
113 	read_unlock(&rx->call_lock);
114 	_leave(" = %p [%d]", call, refcount_read(&call->ref));
115 	return call;
116 }
117 
118 /*
119  * allocate a new call
120  */
rxrpc_alloc_call(struct rxrpc_sock * rx,gfp_t gfp,unsigned int debug_id)121 struct rxrpc_call *rxrpc_alloc_call(struct rxrpc_sock *rx, gfp_t gfp,
122 				    unsigned int debug_id)
123 {
124 	struct rxrpc_call *call;
125 	struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk));
126 
127 	call = kmem_cache_zalloc(rxrpc_call_jar, gfp);
128 	if (!call)
129 		return NULL;
130 
131 	mutex_init(&call->user_mutex);
132 
133 	/* Prevent lockdep reporting a deadlock false positive between the afs
134 	 * filesystem and sys_sendmsg() via the mmap sem.
135 	 */
136 	if (rx->sk.sk_kern_sock)
137 		lockdep_set_class(&call->user_mutex,
138 				  &rxrpc_call_user_mutex_lock_class_key);
139 
140 	timer_setup(&call->timer, rxrpc_call_timer_expired, 0);
141 	INIT_WORK(&call->destroyer, rxrpc_destroy_call);
142 	INIT_LIST_HEAD(&call->link);
143 	INIT_LIST_HEAD(&call->wait_link);
144 	INIT_LIST_HEAD(&call->accept_link);
145 	INIT_LIST_HEAD(&call->recvmsg_link);
146 	INIT_LIST_HEAD(&call->sock_link);
147 	INIT_LIST_HEAD(&call->attend_link);
148 	skb_queue_head_init(&call->recvmsg_queue);
149 	skb_queue_head_init(&call->rx_queue);
150 	skb_queue_head_init(&call->rx_oos_queue);
151 	init_waitqueue_head(&call->waitq);
152 	spin_lock_init(&call->notify_lock);
153 	refcount_set(&call->ref, 1);
154 	call->debug_id		= debug_id;
155 	call->rx_pkt_offset	= USHRT_MAX;
156 	call->tx_total_len	= -1;
157 	call->tx_jumbo_max	= 1;
158 	call->next_rx_timo	= 20 * HZ;
159 	call->next_req_timo	= 1 * HZ;
160 	call->ackr_window	= 1;
161 	call->ackr_wtop		= 1;
162 	call->delay_ack_at	= KTIME_MAX;
163 	call->rack_timo_at	= KTIME_MAX;
164 	call->ping_at		= KTIME_MAX;
165 	call->keepalive_at	= KTIME_MAX;
166 	call->expect_rx_by	= KTIME_MAX;
167 	call->expect_req_by	= KTIME_MAX;
168 	call->expect_term_by	= KTIME_MAX;
169 
170 	memset(&call->sock_node, 0xed, sizeof(call->sock_node));
171 
172 	call->rx_winsize = rxrpc_rx_window_size;
173 	call->tx_winsize = 16;
174 
175 	call->cong_cwnd = RXRPC_MIN_CWND;
176 	call->cong_ssthresh = RXRPC_TX_MAX_WINDOW;
177 
178 	rxrpc_call_init_rtt(call);
179 
180 	call->rxnet = rxnet;
181 	call->rtt_avail = RXRPC_CALL_RTT_AVAIL_MASK;
182 	atomic_inc(&rxnet->nr_calls);
183 	return call;
184 }
185 
186 /*
187  * Allocate a new client call.
188  */
rxrpc_alloc_client_call(struct rxrpc_sock * rx,struct rxrpc_conn_parameters * cp,struct rxrpc_call_params * p,gfp_t gfp,unsigned int debug_id)189 static struct rxrpc_call *rxrpc_alloc_client_call(struct rxrpc_sock *rx,
190 						  struct rxrpc_conn_parameters *cp,
191 						  struct rxrpc_call_params *p,
192 						  gfp_t gfp,
193 						  unsigned int debug_id)
194 {
195 	struct rxrpc_call *call;
196 	ktime_t now;
197 	int ret;
198 
199 	_enter("");
200 
201 	call = rxrpc_alloc_call(rx, gfp, debug_id);
202 	if (!call)
203 		return ERR_PTR(-ENOMEM);
204 	now = ktime_get_real();
205 	call->acks_latest_ts	= now;
206 	call->cong_tstamp	= now;
207 	call->dest_srx		= cp->peer->srx;
208 	call->dest_srx.srx_service = cp->service_id;
209 	call->interruptibility	= p->interruptibility;
210 	call->tx_total_len	= p->tx_total_len;
211 	call->key		= key_get(cp->key);
212 	call->peer		= rxrpc_get_peer(cp->peer, rxrpc_peer_get_call);
213 	call->local		= rxrpc_get_local(cp->local, rxrpc_local_get_call);
214 	call->security_level	= cp->security_level;
215 	if (p->kernel)
216 		__set_bit(RXRPC_CALL_KERNEL, &call->flags);
217 	if (cp->upgrade)
218 		__set_bit(RXRPC_CALL_UPGRADE, &call->flags);
219 	if (cp->exclusive)
220 		__set_bit(RXRPC_CALL_EXCLUSIVE, &call->flags);
221 
222 	if (p->timeouts.normal)
223 		call->next_rx_timo = umin(p->timeouts.normal, 1);
224 	if (p->timeouts.idle)
225 		call->next_req_timo = umin(p->timeouts.idle, 1);
226 	if (p->timeouts.hard)
227 		call->hard_timo = p->timeouts.hard;
228 
229 	ret = rxrpc_init_client_call_security(call);
230 	if (ret < 0) {
231 		rxrpc_prefail_call(call, RXRPC_CALL_LOCAL_ERROR, ret);
232 		rxrpc_put_call(call, rxrpc_call_put_discard_error);
233 		return ERR_PTR(ret);
234 	}
235 
236 	rxrpc_set_call_state(call, RXRPC_CALL_CLIENT_AWAIT_CONN);
237 
238 	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref),
239 			 p->user_call_ID, rxrpc_call_new_client);
240 
241 	_leave(" = %p", call);
242 	return call;
243 }
244 
245 /*
246  * Initiate the call ack/resend/expiry timer.
247  */
rxrpc_start_call_timer(struct rxrpc_call * call)248 void rxrpc_start_call_timer(struct rxrpc_call *call)
249 {
250 	if (call->hard_timo) {
251 		ktime_t delay = ms_to_ktime(call->hard_timo * 1000);
252 
253 		call->expect_term_by = ktime_add(ktime_get_real(), delay);
254 		trace_rxrpc_timer_set(call, delay, rxrpc_timer_trace_hard);
255 	}
256 	call->timer.expires = jiffies;
257 }
258 
259 /*
260  * Wait for a call slot to become available.
261  */
rxrpc_get_call_slot(struct rxrpc_call_params * p,gfp_t gfp)262 static struct semaphore *rxrpc_get_call_slot(struct rxrpc_call_params *p, gfp_t gfp)
263 {
264 	struct semaphore *limiter = &rxrpc_call_limiter;
265 
266 	if (p->kernel)
267 		limiter = &rxrpc_kernel_call_limiter;
268 	if (p->interruptibility == RXRPC_UNINTERRUPTIBLE) {
269 		down(limiter);
270 		return limiter;
271 	}
272 	return down_interruptible(limiter) < 0 ? NULL : limiter;
273 }
274 
275 /*
276  * Release a call slot.
277  */
rxrpc_put_call_slot(struct rxrpc_call * call)278 static void rxrpc_put_call_slot(struct rxrpc_call *call)
279 {
280 	struct semaphore *limiter = &rxrpc_call_limiter;
281 
282 	if (test_bit(RXRPC_CALL_KERNEL, &call->flags))
283 		limiter = &rxrpc_kernel_call_limiter;
284 	up(limiter);
285 }
286 
287 /*
288  * Start the process of connecting a call.  We obtain a peer and a connection
289  * bundle, but the actual association of a call with a connection is offloaded
290  * to the I/O thread to simplify locking.
291  */
rxrpc_connect_call(struct rxrpc_call * call,gfp_t gfp)292 static int rxrpc_connect_call(struct rxrpc_call *call, gfp_t gfp)
293 {
294 	struct rxrpc_local *local = call->local;
295 	int ret = -ENOMEM;
296 
297 	_enter("{%d,%lx},", call->debug_id, call->user_call_ID);
298 
299 	ret = rxrpc_look_up_bundle(call, gfp);
300 	if (ret < 0)
301 		goto error;
302 
303 	trace_rxrpc_client(NULL, -1, rxrpc_client_queue_new_call);
304 	rxrpc_get_call(call, rxrpc_call_get_io_thread);
305 	spin_lock_irq(&local->client_call_lock);
306 	list_add_tail(&call->wait_link, &local->new_client_calls);
307 	spin_unlock_irq(&local->client_call_lock);
308 	rxrpc_wake_up_io_thread(local);
309 	return 0;
310 
311 error:
312 	__set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
313 	return ret;
314 }
315 
316 /*
317  * Set up a call for the given parameters.
318  * - Called with the socket lock held, which it must release.
319  * - If it returns a call, the call's lock will need releasing by the caller.
320  */
rxrpc_new_client_call(struct rxrpc_sock * rx,struct rxrpc_conn_parameters * cp,struct rxrpc_call_params * p,gfp_t gfp,unsigned int debug_id)321 struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
322 					 struct rxrpc_conn_parameters *cp,
323 					 struct rxrpc_call_params *p,
324 					 gfp_t gfp,
325 					 unsigned int debug_id)
326 	__releases(&rx->sk.sk_lock)
327 	__acquires(&call->user_mutex)
328 {
329 	struct rxrpc_call *call, *xcall;
330 	struct rxrpc_net *rxnet;
331 	struct semaphore *limiter;
332 	struct rb_node *parent, **pp;
333 	int ret;
334 
335 	_enter("%p,%lx", rx, p->user_call_ID);
336 
337 	if (WARN_ON_ONCE(!cp->peer)) {
338 		release_sock(&rx->sk);
339 		return ERR_PTR(-EIO);
340 	}
341 
342 	limiter = rxrpc_get_call_slot(p, gfp);
343 	if (!limiter) {
344 		release_sock(&rx->sk);
345 		return ERR_PTR(-ERESTARTSYS);
346 	}
347 
348 	call = rxrpc_alloc_client_call(rx, cp, p, gfp, debug_id);
349 	if (IS_ERR(call)) {
350 		release_sock(&rx->sk);
351 		up(limiter);
352 		_leave(" = %ld", PTR_ERR(call));
353 		return call;
354 	}
355 
356 	/* We need to protect a partially set up call against the user as we
357 	 * will be acting outside the socket lock.
358 	 */
359 	mutex_lock(&call->user_mutex);
360 
361 	/* Publish the call, even though it is incompletely set up as yet */
362 	write_lock(&rx->call_lock);
363 
364 	pp = &rx->calls.rb_node;
365 	parent = NULL;
366 	while (*pp) {
367 		parent = *pp;
368 		xcall = rb_entry(parent, struct rxrpc_call, sock_node);
369 
370 		if (p->user_call_ID < xcall->user_call_ID)
371 			pp = &(*pp)->rb_left;
372 		else if (p->user_call_ID > xcall->user_call_ID)
373 			pp = &(*pp)->rb_right;
374 		else
375 			goto error_dup_user_ID;
376 	}
377 
378 	rcu_assign_pointer(call->socket, rx);
379 	call->user_call_ID = p->user_call_ID;
380 	__set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
381 	rxrpc_get_call(call, rxrpc_call_get_userid);
382 	rb_link_node(&call->sock_node, parent, pp);
383 	rb_insert_color(&call->sock_node, &rx->calls);
384 	list_add(&call->sock_link, &rx->sock_calls);
385 
386 	write_unlock(&rx->call_lock);
387 
388 	rxnet = call->rxnet;
389 	spin_lock(&rxnet->call_lock);
390 	list_add_tail_rcu(&call->link, &rxnet->calls);
391 	spin_unlock(&rxnet->call_lock);
392 
393 	/* From this point on, the call is protected by its own lock. */
394 	release_sock(&rx->sk);
395 
396 	/* Set up or get a connection record and set the protocol parameters,
397 	 * including channel number and call ID.
398 	 */
399 	ret = rxrpc_connect_call(call, gfp);
400 	if (ret < 0)
401 		goto error_attached_to_socket;
402 
403 	_leave(" = %p [new]", call);
404 	return call;
405 
406 	/* We unexpectedly found the user ID in the list after taking
407 	 * the call_lock.  This shouldn't happen unless the user races
408 	 * with itself and tries to add the same user ID twice at the
409 	 * same time in different threads.
410 	 */
411 error_dup_user_ID:
412 	write_unlock(&rx->call_lock);
413 	release_sock(&rx->sk);
414 	rxrpc_prefail_call(call, RXRPC_CALL_LOCAL_ERROR, -EEXIST);
415 	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref), 0,
416 			 rxrpc_call_see_userid_exists);
417 	mutex_unlock(&call->user_mutex);
418 	rxrpc_put_call(call, rxrpc_call_put_userid_exists);
419 	_leave(" = -EEXIST");
420 	return ERR_PTR(-EEXIST);
421 
422 	/* We got an error, but the call is attached to the socket and is in
423 	 * need of release.  However, we might now race with recvmsg() when it
424 	 * completion notifies the socket.  Return 0 from sys_sendmsg() and
425 	 * leave the error to recvmsg() to deal with.
426 	 */
427 error_attached_to_socket:
428 	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref), ret,
429 			 rxrpc_call_see_connect_failed);
430 	rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR, 0, ret);
431 	_leave(" = c=%08x [err]", call->debug_id);
432 	return call;
433 }
434 
435 /*
436  * Set up an incoming call.  call->conn points to the connection.
437  * This is called with interrupts disabled and isn't allowed to fail.
438  */
rxrpc_incoming_call(struct rxrpc_sock * rx,struct rxrpc_call * call,struct sk_buff * skb)439 void rxrpc_incoming_call(struct rxrpc_sock *rx,
440 			 struct rxrpc_call *call,
441 			 struct sk_buff *skb)
442 {
443 	struct rxrpc_connection *conn = call->conn;
444 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
445 	u32 chan;
446 
447 	_enter(",%d", call->conn->debug_id);
448 
449 	rcu_assign_pointer(call->socket, rx);
450 	call->call_id		= sp->hdr.callNumber;
451 	call->dest_srx.srx_service = sp->hdr.serviceId;
452 	call->cid		= sp->hdr.cid;
453 	call->cong_tstamp	= skb->tstamp;
454 
455 	__set_bit(RXRPC_CALL_EXPOSED, &call->flags);
456 	rxrpc_set_call_state(call, RXRPC_CALL_SERVER_RECV_REQUEST);
457 
458 	spin_lock(&conn->state_lock);
459 
460 	switch (conn->state) {
461 	case RXRPC_CONN_SERVICE_UNSECURED:
462 	case RXRPC_CONN_SERVICE_CHALLENGING:
463 		__set_bit(RXRPC_CALL_CONN_CHALLENGING, &call->flags);
464 		break;
465 	case RXRPC_CONN_SERVICE:
466 		break;
467 
468 	case RXRPC_CONN_ABORTED:
469 		rxrpc_set_call_completion(call, conn->completion,
470 					  conn->abort_code, conn->error);
471 		break;
472 	default:
473 		BUG();
474 	}
475 
476 	rxrpc_get_call(call, rxrpc_call_get_io_thread);
477 
478 	/* Set the channel for this call.  We don't get channel_lock as we're
479 	 * only defending against the data_ready handler (which we're called
480 	 * from) and the RESPONSE packet parser (which is only really
481 	 * interested in call_counter and can cope with a disagreement with the
482 	 * call pointer).
483 	 */
484 	chan = sp->hdr.cid & RXRPC_CHANNELMASK;
485 	conn->channels[chan].call_counter = call->call_id;
486 	conn->channels[chan].call_id = call->call_id;
487 	conn->channels[chan].call = call;
488 	spin_unlock(&conn->state_lock);
489 
490 	spin_lock(&conn->peer->lock);
491 	hlist_add_head(&call->error_link, &conn->peer->error_targets);
492 	spin_unlock(&conn->peer->lock);
493 
494 	rxrpc_start_call_timer(call);
495 	_leave("");
496 }
497 
498 /*
499  * Note the re-emergence of a call.
500  */
rxrpc_see_call(struct rxrpc_call * call,enum rxrpc_call_trace why)501 void rxrpc_see_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
502 {
503 	if (call) {
504 		int r = refcount_read(&call->ref);
505 
506 		trace_rxrpc_call(call->debug_id, r, 0, why);
507 	}
508 }
509 
rxrpc_try_get_call(struct rxrpc_call * call,enum rxrpc_call_trace why)510 struct rxrpc_call *rxrpc_try_get_call(struct rxrpc_call *call,
511 				      enum rxrpc_call_trace why)
512 {
513 	int r;
514 
515 	if (!call || !__refcount_inc_not_zero(&call->ref, &r))
516 		return NULL;
517 	trace_rxrpc_call(call->debug_id, r + 1, 0, why);
518 	return call;
519 }
520 
521 /*
522  * Note the addition of a ref on a call.
523  */
rxrpc_get_call(struct rxrpc_call * call,enum rxrpc_call_trace why)524 void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
525 {
526 	int r;
527 
528 	__refcount_inc(&call->ref, &r);
529 	trace_rxrpc_call(call->debug_id, r + 1, 0, why);
530 }
531 
532 /*
533  * Clean up the transmission buffers.
534  */
rxrpc_cleanup_tx_buffers(struct rxrpc_call * call)535 static void rxrpc_cleanup_tx_buffers(struct rxrpc_call *call)
536 {
537 	struct rxrpc_txqueue *tq, *next;
538 
539 	for (tq = call->tx_queue; tq; tq = next) {
540 		next = tq->next;
541 		for (int i = 0; i < RXRPC_NR_TXQUEUE; i++)
542 			if (tq->bufs[i])
543 				rxrpc_put_txbuf(tq->bufs[i], rxrpc_txbuf_put_cleaned);
544 		trace_rxrpc_tq(call, tq, 0, rxrpc_tq_cleaned);
545 		kfree(tq);
546 	}
547 }
548 
549 /*
550  * Clean up the receive buffers.
551  */
rxrpc_cleanup_rx_buffers(struct rxrpc_call * call)552 static void rxrpc_cleanup_rx_buffers(struct rxrpc_call *call)
553 {
554 	rxrpc_purge_queue(&call->recvmsg_queue);
555 	rxrpc_purge_queue(&call->rx_queue);
556 	rxrpc_purge_queue(&call->rx_oos_queue);
557 	kfree(call->rx_dec_buffer);
558 }
559 
560 /*
561  * Detach a call from its owning socket.
562  */
rxrpc_release_call(struct rxrpc_sock * rx,struct rxrpc_call * call)563 void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
564 {
565 	struct rxrpc_connection *conn = call->conn;
566 	bool putu = false;
567 
568 	_enter("{%d,%d}", call->debug_id, refcount_read(&call->ref));
569 
570 	trace_rxrpc_call(call->debug_id, refcount_read(&call->ref),
571 			 call->flags, rxrpc_call_see_release);
572 
573 	if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
574 		BUG();
575 
576 	rxrpc_put_call_slot(call);
577 
578 	/* Note that at this point, the call may still be on or may have been
579 	 * added back on to the socket receive queue.  recvmsg() must discard
580 	 * released calls.  The CALL_RELEASED flag should prevent further
581 	 * notifications.
582 	 */
583 	spin_lock_irq(&rx->recvmsg_lock);
584 	spin_unlock_irq(&rx->recvmsg_lock);
585 
586 	write_lock(&rx->call_lock);
587 
588 	if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
589 		rb_erase(&call->sock_node, &rx->calls);
590 		memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
591 		putu = true;
592 	}
593 
594 	list_del(&call->sock_link);
595 	write_unlock(&rx->call_lock);
596 
597 	_debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
598 
599 	if (putu)
600 		rxrpc_put_call(call, rxrpc_call_put_userid);
601 
602 	_leave("");
603 }
604 
605 /*
606  * release all the calls associated with a socket
607  */
rxrpc_release_calls_on_socket(struct rxrpc_sock * rx)608 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
609 {
610 	struct rxrpc_call *call;
611 
612 	_enter("%p", rx);
613 
614 	while (!list_empty(&rx->to_be_accepted)) {
615 		call = list_entry(rx->to_be_accepted.next,
616 				  struct rxrpc_call, accept_link);
617 		list_del(&call->accept_link);
618 		rxrpc_propose_abort(call, RX_CALL_DEAD, -ECONNRESET,
619 				    rxrpc_abort_call_sock_release_tba);
620 		rxrpc_put_call(call, rxrpc_call_put_release_sock_tba);
621 	}
622 
623 	while (!list_empty(&rx->sock_calls)) {
624 		call = list_entry(rx->sock_calls.next,
625 				  struct rxrpc_call, sock_link);
626 		rxrpc_get_call(call, rxrpc_call_get_release_sock);
627 		rxrpc_propose_abort(call, RX_CALL_DEAD, -ECONNRESET,
628 				    rxrpc_abort_call_sock_release);
629 		rxrpc_release_call(rx, call);
630 		rxrpc_put_call(call, rxrpc_call_put_release_sock);
631 	}
632 
633 	while ((call = list_first_entry_or_null(&rx->recvmsg_q,
634 						struct rxrpc_call, recvmsg_link))) {
635 		list_del_init(&call->recvmsg_link);
636 		rxrpc_put_call(call, rxrpc_call_put_release_recvmsg_q);
637 	}
638 
639 	_leave("");
640 }
641 
642 /*
643  * release a call
644  */
rxrpc_put_call(struct rxrpc_call * call,enum rxrpc_call_trace why)645 void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace why)
646 {
647 	struct rxrpc_net *rxnet = call->rxnet;
648 	unsigned int debug_id = call->debug_id;
649 	bool dead;
650 	int r;
651 
652 	ASSERT(call != NULL);
653 
654 	dead = __refcount_dec_and_test(&call->ref, &r);
655 	trace_rxrpc_call(debug_id, r - 1, 0, why);
656 	if (dead) {
657 		ASSERTCMP(__rxrpc_call_state(call), ==, RXRPC_CALL_COMPLETE);
658 
659 		spin_lock(&rxnet->call_lock);
660 		list_del_rcu(&call->link);
661 		spin_unlock(&rxnet->call_lock);
662 
663 		rxrpc_cleanup_call(call);
664 	}
665 }
666 
667 /*
668  * Free up the call under RCU.
669  */
rxrpc_rcu_free_call(struct rcu_head * rcu)670 static void rxrpc_rcu_free_call(struct rcu_head *rcu)
671 {
672 	struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
673 	struct rxrpc_net *rxnet = READ_ONCE(call->rxnet);
674 
675 	kmem_cache_free(rxrpc_call_jar, call);
676 	if (atomic_dec_and_test(&rxnet->nr_calls))
677 		wake_up_var(&rxnet->nr_calls);
678 }
679 
680 /*
681  * Final call destruction - but must be done in process context.
682  */
rxrpc_destroy_call(struct work_struct * work)683 static void rxrpc_destroy_call(struct work_struct *work)
684 {
685 	struct rxrpc_call *call = container_of(work, struct rxrpc_call, destroyer);
686 
687 	timer_delete_sync(&call->timer);
688 
689 	rxrpc_cleanup_tx_buffers(call);
690 	rxrpc_cleanup_rx_buffers(call);
691 	rxrpc_put_txbuf(call->tx_pending, rxrpc_txbuf_put_cleaned);
692 	rxrpc_put_connection(call->conn, rxrpc_conn_put_call);
693 	rxrpc_deactivate_bundle(call->bundle);
694 	rxrpc_put_bundle(call->bundle, rxrpc_bundle_put_call);
695 	rxrpc_put_peer(call->peer, rxrpc_peer_put_call);
696 	rxrpc_put_local(call->local, rxrpc_local_put_call);
697 	key_put(call->key);
698 	call_rcu(&call->rcu, rxrpc_rcu_free_call);
699 }
700 
701 /*
702  * clean up a call
703  */
rxrpc_cleanup_call(struct rxrpc_call * call)704 void rxrpc_cleanup_call(struct rxrpc_call *call)
705 {
706 	memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
707 
708 	ASSERTCMP(__rxrpc_call_state(call), ==, RXRPC_CALL_COMPLETE);
709 	ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
710 
711 	timer_delete(&call->timer);
712 
713 	if (rcu_read_lock_held())
714 		/* Can't use the rxrpc workqueue as we need to cancel/flush
715 		 * something that may be running/waiting there.
716 		 */
717 		schedule_work(&call->destroyer);
718 	else
719 		rxrpc_destroy_call(&call->destroyer);
720 }
721 
722 /*
723  * Make sure that all calls are gone from a network namespace.  To reach this
724  * point, any open UDP sockets in that namespace must have been closed, so any
725  * outstanding calls cannot be doing I/O.
726  */
rxrpc_destroy_all_calls(struct rxrpc_net * rxnet)727 void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet)
728 {
729 	struct rxrpc_call *call;
730 
731 	_enter("");
732 
733 	if (!list_empty(&rxnet->calls)) {
734 		int shown = 0;
735 
736 		spin_lock(&rxnet->call_lock);
737 
738 		list_for_each_entry(call, &rxnet->calls, link) {
739 			rxrpc_see_call(call, rxrpc_call_see_still_live);
740 
741 			pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
742 			       call, refcount_read(&call->ref),
743 			       rxrpc_call_states[__rxrpc_call_state(call)],
744 			       call->flags, call->events);
745 
746 			if (++shown >= 10)
747 				break;
748 		}
749 
750 		spin_unlock(&rxnet->call_lock);
751 	}
752 
753 	atomic_dec(&rxnet->nr_calls);
754 	wait_var_event(&rxnet->nr_calls, !atomic_read(&rxnet->nr_calls));
755 }
756 
757 /**
758  * rxrpc_kernel_query_call_security - Query call's security parameters
759  * @call: The call to query
760  * @_service_id: Where to return the service ID
761  * @_enctype: Where to return the "encoding type"
762  *
763  * This queries the security parameters of a call, setting *@_service_id and
764  * *@_enctype and returning the security class.
765  *
766  * Return: The security class protocol number.
767  */
rxrpc_kernel_query_call_security(struct rxrpc_call * call,u16 * _service_id,u32 * _enctype)768 u8 rxrpc_kernel_query_call_security(struct rxrpc_call *call,
769 				    u16 *_service_id, u32 *_enctype)
770 {
771 	*_service_id = call->dest_srx.srx_service;
772 	*_enctype = call->security_enctype;
773 	return call->security_ix;
774 }
775 EXPORT_SYMBOL(rxrpc_kernel_query_call_security);
776