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