xref: /linux/fs/afs/rxrpc.c (revision 056a5087d87ead77dedbe9cf5bde53b7cd4b4651)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* Maintain an RxRPC server socket to do AFS communications through
3  *
4  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
5  * Written by David Howells (dhowells@redhat.com)
6  */
7 
8 #include <linux/slab.h>
9 #include <linux/sched/signal.h>
10 
11 #include <net/sock.h>
12 #include <net/af_rxrpc.h>
13 #include "internal.h"
14 #include "afs_cm.h"
15 #include "protocol_yfs.h"
16 #define RXRPC_TRACE_ONLY_DEFINE_ENUMS
17 #include <trace/events/rxrpc.h>
18 
19 struct workqueue_struct *afs_async_calls;
20 
21 static void afs_deferred_free_worker(struct work_struct *work);
22 static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long);
23 static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long);
24 static void afs_process_async_call(struct work_struct *);
25 static void afs_rx_new_call(struct sock *, struct rxrpc_call *, unsigned long);
26 static void afs_rx_discard_new_call(struct rxrpc_call *, unsigned long);
27 static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID);
28 static void afs_rx_notify_oob(struct sock *sk, struct sk_buff *oob);
29 static int afs_deliver_cm_op_id(struct afs_call *);
30 
31 static const struct rxrpc_kernel_ops afs_rxrpc_callback_ops = {
32 	.notify_new_call	= afs_rx_new_call,
33 	.discard_new_call	= afs_rx_discard_new_call,
34 	.user_attach_call	= afs_rx_attach,
35 	.notify_oob		= afs_rx_notify_oob,
36 };
37 
38 /* asynchronous incoming call initial processing */
39 static const struct afs_call_type afs_RXCMxxxx = {
40 	.name		= "CB.xxxx",
41 	.deliver	= afs_deliver_cm_op_id,
42 };
43 
44 /*
45  * open an RxRPC socket and bind it to be a server for callback notifications
46  * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
47  */
48 int afs_open_socket(struct afs_net *net)
49 {
50 	struct sockaddr_rxrpc srx;
51 	struct socket *socket;
52 	int ret;
53 
54 	_enter("");
55 
56 	ret = sock_create_kern(net->net, AF_RXRPC, SOCK_DGRAM, PF_INET6, &socket);
57 	if (ret < 0)
58 		goto error_1;
59 
60 	socket->sk->sk_allocation = GFP_NOFS;
61 	socket->sk->sk_user_data = net;
62 
63 	/* bind the callback manager's address to make this a server socket */
64 	memset(&srx, 0, sizeof(srx));
65 	srx.srx_family			= AF_RXRPC;
66 	srx.srx_service			= CM_SERVICE;
67 	srx.transport_type		= SOCK_DGRAM;
68 	srx.transport_len		= sizeof(srx.transport.sin6);
69 	srx.transport.sin6.sin6_family	= AF_INET6;
70 	srx.transport.sin6.sin6_port	= htons(AFS_CM_PORT);
71 
72 	ret = rxrpc_sock_set_min_security_level(socket->sk,
73 						RXRPC_SECURITY_ENCRYPT);
74 	if (ret < 0)
75 		goto error_2;
76 
77 	ret = rxrpc_sock_set_manage_response(socket->sk, true);
78 	if (ret < 0)
79 		goto error_2;
80 
81 	ret = afs_create_token_key(net, socket);
82 	if (ret < 0)
83 		pr_err("Couldn't create RxGK CM key: %d\n", ret);
84 
85 	ret = kernel_bind(socket, (struct sockaddr_unsized *) &srx, sizeof(srx));
86 	if (ret == -EADDRINUSE) {
87 		srx.transport.sin6.sin6_port = 0;
88 		ret = kernel_bind(socket, (struct sockaddr_unsized *) &srx, sizeof(srx));
89 	}
90 	if (ret < 0)
91 		goto error_2;
92 
93 	srx.srx_service = YFS_CM_SERVICE;
94 	ret = kernel_bind(socket, (struct sockaddr_unsized *) &srx, sizeof(srx));
95 	if (ret < 0)
96 		goto error_2;
97 
98 	/* Ideally, we'd turn on service upgrade here, but we can't because
99 	 * OpenAFS is buggy and leaks the userStatus field from packet to
100 	 * packet and between FS packets and CB packets - so if we try to do an
101 	 * upgrade on an FS packet, OpenAFS will leak that into the CB packet
102 	 * it sends back to us.
103 	 */
104 
105 	rxrpc_kernel_set_notifications(socket, &afs_rxrpc_callback_ops);
106 
107 	ret = kernel_listen(socket, INT_MAX);
108 	if (ret < 0)
109 		goto error_2;
110 
111 	net->socket = socket;
112 	afs_charge_preallocation(&net->charge_preallocation_work);
113 	_leave(" = 0");
114 	return 0;
115 
116 error_2:
117 	sock_release(socket);
118 error_1:
119 	_leave(" = %d", ret);
120 	return ret;
121 }
122 
123 /*
124  * close the RxRPC socket AFS was using
125  */
126 void afs_close_socket(struct afs_net *net)
127 {
128 	_enter("");
129 
130 	cancel_work_sync(&net->charge_preallocation_work);
131 	kernel_listen(net->socket, 0);
132 	flush_workqueue(afs_async_calls);
133 
134 	if (net->spare_incoming_call) {
135 		afs_put_call(net->spare_incoming_call);
136 		net->spare_incoming_call = NULL;
137 	}
138 
139 	_debug("outstanding %u", atomic_read(&net->nr_outstanding_calls));
140 	wait_var_event(&net->nr_outstanding_calls,
141 		       !atomic_read(&net->nr_outstanding_calls));
142 	_debug("no outstanding calls");
143 
144 	kernel_sock_shutdown(net->socket, SHUT_RDWR);
145 	flush_workqueue(afs_async_calls);
146 	net->socket->sk->sk_user_data = NULL;
147 	sock_release(net->socket);
148 	key_put(net->fs_cm_token_key);
149 
150 	_debug("dework");
151 	_leave("");
152 }
153 
154 /*
155  * Allocate a call.
156  */
157 static struct afs_call *afs_alloc_call(struct afs_net *net,
158 				       const struct afs_call_type *type,
159 				       gfp_t gfp)
160 {
161 	struct afs_call *call;
162 	int o;
163 
164 	call = kzalloc_obj(*call, gfp);
165 	if (!call)
166 		return NULL;
167 
168 	call->type = type;
169 	call->net = net;
170 	call->debug_id = atomic_inc_return(&rxrpc_debug_id);
171 	refcount_set(&call->ref, 1);
172 	INIT_WORK(&call->async_work, type->async_rx ?: afs_process_async_call);
173 	INIT_WORK(&call->work, call->type->work);
174 	INIT_WORK(&call->free_work, afs_deferred_free_worker);
175 	init_waitqueue_head(&call->waitq);
176 	spin_lock_init(&call->state_lock);
177 	call->iter = &call->def_iter;
178 
179 	o = atomic_inc_return(&net->nr_outstanding_calls);
180 	trace_afs_call(call->debug_id, afs_call_trace_alloc, 1, o,
181 		       __builtin_return_address(0));
182 	return call;
183 }
184 
185 static void afs_free_call(struct afs_call *call)
186 {
187 	struct afs_net *net = call->net;
188 	int o;
189 
190 	ASSERT(!work_pending(&call->async_work));
191 
192 	rxrpc_kernel_put_peer(call->peer);
193 
194 	if (call->rxcall) {
195 		rxrpc_kernel_shutdown_call(net->socket, call->rxcall);
196 		rxrpc_kernel_put_call(net->socket, call->rxcall);
197 		call->rxcall = NULL;
198 	}
199 	if (call->type->destructor)
200 		call->type->destructor(call);
201 
202 	afs_unuse_server_notime(call->net, call->server, afs_server_trace_unuse_call);
203 	kfree(call->request);
204 
205 	o = atomic_read(&net->nr_outstanding_calls);
206 	trace_afs_call(call->debug_id, afs_call_trace_free, 0, o,
207 		       __builtin_return_address(0));
208 	kfree(call);
209 
210 	o = atomic_dec_return(&net->nr_outstanding_calls);
211 	if (o == 0)
212 		wake_up_var(&net->nr_outstanding_calls);
213 }
214 
215 /*
216  * Dispose of a reference on a call.
217  */
218 void afs_put_call(struct afs_call *call)
219 {
220 	struct afs_net *net = call->net;
221 	unsigned int debug_id = call->debug_id;
222 	bool zero;
223 	int r, o;
224 
225 	zero = __refcount_dec_and_test(&call->ref, &r);
226 	o = atomic_read(&net->nr_outstanding_calls);
227 	trace_afs_call(debug_id, afs_call_trace_put, r - 1, o,
228 		       __builtin_return_address(0));
229 	if (zero)
230 		afs_free_call(call);
231 }
232 
233 static void afs_deferred_free_worker(struct work_struct *work)
234 {
235 	struct afs_call *call = container_of(work, struct afs_call, free_work);
236 
237 	afs_free_call(call);
238 }
239 
240 /*
241  * Dispose of a reference on a call, deferring the cleanup to a workqueue
242  * to avoid lock recursion.
243  */
244 void afs_deferred_put_call(struct afs_call *call)
245 {
246 	struct afs_net *net = call->net;
247 	unsigned int debug_id = call->debug_id;
248 	bool zero;
249 	int r, o;
250 
251 	zero = __refcount_dec_and_test(&call->ref, &r);
252 	o = atomic_read(&net->nr_outstanding_calls);
253 	trace_afs_call(debug_id, afs_call_trace_put, r - 1, o,
254 		       __builtin_return_address(0));
255 	if (zero)
256 		schedule_work(&call->free_work);
257 }
258 
259 /*
260  * Queue the call for actual work.
261  */
262 static void afs_queue_call_work(struct afs_call *call)
263 {
264 	if (call->type->work) {
265 		afs_get_call(call, afs_call_trace_work);
266 		if (!queue_work(afs_wq, &call->work))
267 			afs_put_call(call);
268 	}
269 }
270 
271 /*
272  * allocate a call with flat request and reply buffers
273  */
274 struct afs_call *afs_alloc_flat_call(struct afs_net *net,
275 				     const struct afs_call_type *type,
276 				     size_t request_size, size_t reply_max)
277 {
278 	struct afs_call *call;
279 
280 	call = afs_alloc_call(net, type, GFP_NOFS);
281 	if (!call)
282 		goto nomem_call;
283 
284 	if (request_size) {
285 		call->request_size = request_size;
286 		call->request = kmalloc(request_size, GFP_NOFS);
287 		if (!call->request)
288 			goto nomem_free;
289 	}
290 
291 	if (reply_max) {
292 		call->reply_max = reply_max;
293 		call->buffer = kmalloc(reply_max, GFP_NOFS);
294 		if (!call->buffer)
295 			goto nomem_free;
296 	}
297 
298 	afs_extract_to_buf(call, call->reply_max);
299 	call->operation_ID = type->op;
300 	init_waitqueue_head(&call->waitq);
301 	return call;
302 
303 nomem_free:
304 	afs_put_call(call);
305 nomem_call:
306 	return NULL;
307 }
308 
309 /*
310  * clean up a call with flat buffer
311  */
312 void afs_flat_call_destructor(struct afs_call *call)
313 {
314 	_enter("");
315 
316 	kfree(call->request);
317 	call->request = NULL;
318 	kfree(call->buffer);
319 	call->buffer = NULL;
320 }
321 
322 /*
323  * Advance the AFS call state when the RxRPC call ends the transmit phase.
324  */
325 static void afs_notify_end_request_tx(struct sock *sock,
326 				      struct rxrpc_call *rxcall,
327 				      unsigned long call_user_ID)
328 {
329 	struct afs_call *call = (struct afs_call *)call_user_ID;
330 
331 	afs_set_call_state(call, AFS_CALL_CL_REQUESTING, AFS_CALL_CL_AWAIT_REPLY);
332 }
333 
334 /*
335  * Initiate a call and synchronously queue up the parameters for dispatch.  Any
336  * error is stored into the call struct, which the caller must check for.
337  */
338 void afs_make_call(struct afs_call *call, gfp_t gfp)
339 {
340 	struct rxrpc_call *rxcall;
341 	struct msghdr msg;
342 	struct kvec iov[1];
343 	size_t len;
344 	s64 tx_total_len;
345 	int ret;
346 
347 	_enter(",{%pISp+%u},", rxrpc_kernel_remote_addr(call->peer), call->service_id);
348 
349 	ASSERT(call->type != NULL);
350 	ASSERT(call->type->name != NULL);
351 
352 	_debug("____MAKE %p{%s,%x} [%d]____",
353 	       call, call->type->name, key_serial(call->key),
354 	       atomic_read(&call->net->nr_outstanding_calls));
355 
356 	trace_afs_make_call(call);
357 
358 	/* Work out the length we're going to transmit.  This is awkward for
359 	 * calls such as FS.StoreData where there's an extra injection of data
360 	 * after the initial fixed part.
361 	 */
362 	tx_total_len = call->request_size;
363 	if (call->write_iter)
364 		tx_total_len += iov_iter_count(call->write_iter);
365 
366 	/* If the call is going to be asynchronous, we need an extra ref for
367 	 * the call to hold itself so the caller need not hang on to its ref.
368 	 */
369 	if (call->async) {
370 		afs_get_call(call, afs_call_trace_get);
371 		call->drop_ref = true;
372 	}
373 
374 	/* create a call */
375 	rxcall = rxrpc_kernel_begin_call(call->net->socket, call->peer, call->key,
376 					 (unsigned long)call,
377 					 tx_total_len,
378 					 call->max_lifespan,
379 					 gfp,
380 					 (call->async ?
381 					  afs_wake_up_async_call :
382 					  afs_wake_up_call_waiter),
383 					 call->service_id,
384 					 call->upgrade,
385 					 (call->intr ? RXRPC_PREINTERRUPTIBLE :
386 					  RXRPC_UNINTERRUPTIBLE),
387 					 call->debug_id);
388 	if (IS_ERR(rxcall)) {
389 		ret = PTR_ERR(rxcall);
390 		call->error = ret;
391 		goto error_kill_call;
392 	}
393 
394 	call->rxcall = rxcall;
395 	call->issue_time = ktime_get_real();
396 
397 	/* send the request */
398 	iov[0].iov_base	= call->request;
399 	iov[0].iov_len	= call->request_size;
400 
401 	msg.msg_name		= NULL;
402 	msg.msg_namelen		= 0;
403 	iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, iov, 1, call->request_size);
404 	msg.msg_control		= NULL;
405 	msg.msg_controllen	= 0;
406 	msg.msg_flags		= MSG_WAITALL | (call->write_iter ? MSG_MORE : 0);
407 
408 	ret = rxrpc_kernel_send_data(call->net->socket, rxcall,
409 				     &msg, call->request_size,
410 				     afs_notify_end_request_tx);
411 	if (ret < 0)
412 		goto error_do_abort;
413 
414 	if (call->write_iter) {
415 		msg.msg_iter = *call->write_iter;
416 		msg.msg_flags &= ~MSG_MORE;
417 		trace_afs_send_data(call, &msg);
418 
419 		ret = rxrpc_kernel_send_data(call->net->socket,
420 					     call->rxcall, &msg,
421 					     iov_iter_count(&msg.msg_iter),
422 					     afs_notify_end_request_tx);
423 		*call->write_iter = msg.msg_iter;
424 
425 		trace_afs_sent_data(call, &msg, ret);
426 		if (ret < 0)
427 			goto error_do_abort;
428 	}
429 
430 	/* Note that at this point, we may have received the reply or an abort
431 	 * - and an asynchronous call may already have completed.
432 	 *
433 	 * afs_wait_for_call_to_complete(call)
434 	 * must be called to synchronously clean up.
435 	 */
436 	return;
437 
438 error_do_abort:
439 	if (ret != -ECONNABORTED)
440 		rxrpc_kernel_abort_call(call->net->socket, rxcall,
441 					RX_USER_ABORT, ret,
442 					afs_abort_send_data_error);
443 	if (call->async) {
444 		afs_see_call(call, afs_call_trace_async_abort);
445 		return;
446 	}
447 
448 	if (ret == -ECONNABORTED) {
449 		len = 0;
450 		iov_iter_kvec(&msg.msg_iter, ITER_DEST, NULL, 0, 0);
451 		rxrpc_kernel_recv_data(call->net->socket, rxcall,
452 				       &msg.msg_iter, &len, false,
453 				       &call->abort_code, &call->service_id);
454 		call->responded = true;
455 	}
456 	call->error = ret;
457 	trace_afs_call_done(call);
458 error_kill_call:
459 	if (call->async)
460 		afs_see_call(call, afs_call_trace_async_kill);
461 	if (call->type->immediate_cancel)
462 		call->type->immediate_cancel(call);
463 
464 	/* We need to dispose of the extra ref we grabbed for an async call.
465 	 * The call, however, might be queued on afs_async_calls and we need to
466 	 * make sure we don't get any more notifications that might requeue it.
467 	 */
468 	if (call->rxcall)
469 		rxrpc_kernel_shutdown_call(call->net->socket, call->rxcall);
470 	if (call->async) {
471 		if (cancel_work_sync(&call->async_work))
472 			afs_put_call(call);
473 		afs_set_call_complete(call, ret, 0);
474 	}
475 
476 	call->error = ret;
477 	call->state = AFS_CALL_COMPLETE;
478 	_leave(" = %d", ret);
479 }
480 
481 /*
482  * Log remote abort codes that indicate that we have a protocol disagreement
483  * with the server.
484  */
485 static void afs_log_error(struct afs_call *call, s32 remote_abort)
486 {
487 	static int max = 0;
488 	const char *msg;
489 	int m;
490 
491 	switch (remote_abort) {
492 	case RX_EOF:		 msg = "unexpected EOF";	break;
493 	case RXGEN_CC_MARSHAL:	 msg = "client marshalling";	break;
494 	case RXGEN_CC_UNMARSHAL: msg = "client unmarshalling";	break;
495 	case RXGEN_SS_MARSHAL:	 msg = "server marshalling";	break;
496 	case RXGEN_SS_UNMARSHAL: msg = "server unmarshalling";	break;
497 	case RXGEN_DECODE:	 msg = "opcode decode";		break;
498 	case RXGEN_SS_XDRFREE:	 msg = "server XDR cleanup";	break;
499 	case RXGEN_CC_XDRFREE:	 msg = "client XDR cleanup";	break;
500 	case -32:		 msg = "insufficient data";	break;
501 	default:
502 		return;
503 	}
504 
505 	m = max;
506 	if (m < 3) {
507 		max = m + 1;
508 		pr_notice("kAFS: Peer reported %s failure on %s [%pISp]\n",
509 			  msg, call->type->name,
510 			  rxrpc_kernel_remote_addr(call->peer));
511 	}
512 }
513 
514 /*
515  * deliver messages to a call
516  */
517 void afs_deliver_to_call(struct afs_call *call)
518 {
519 	enum afs_call_state state;
520 	size_t len;
521 	u32 abort_code, remote_abort = 0;
522 	int ret;
523 
524 	_enter("%s", call->type->name);
525 
526 	while (state = READ_ONCE(call->state),
527 	       state == AFS_CALL_CL_AWAIT_REPLY ||
528 	       state == AFS_CALL_SV_AWAIT_OP_ID ||
529 	       state == AFS_CALL_SV_AWAIT_REQUEST ||
530 	       state == AFS_CALL_SV_AWAIT_ACK
531 	       ) {
532 		if (state == AFS_CALL_SV_AWAIT_ACK) {
533 			len = 0;
534 			iov_iter_kvec(&call->def_iter, ITER_DEST, NULL, 0, 0);
535 			ret = rxrpc_kernel_recv_data(call->net->socket,
536 						     call->rxcall, &call->def_iter,
537 						     &len, false, &remote_abort,
538 						     &call->service_id);
539 			trace_afs_receive_data(call, &call->def_iter, false, ret);
540 
541 			if (ret == -EINPROGRESS || ret == -EAGAIN)
542 				return;
543 			if (ret < 0 || ret == 1) {
544 				if (ret == 1)
545 					ret = 0;
546 				goto call_complete;
547 			}
548 			return;
549 		}
550 
551 		ret = call->type->deliver(call);
552 		state = READ_ONCE(call->state);
553 		if (ret == 0 && call->unmarshalling_error)
554 			ret = -EBADMSG;
555 		switch (ret) {
556 		case 0:
557 			call->responded = true;
558 			afs_queue_call_work(call);
559 			if (state == AFS_CALL_CL_PROC_REPLY) {
560 				if (call->op)
561 					set_bit(AFS_SERVER_FL_MAY_HAVE_CB,
562 						&call->op->server->flags);
563 				goto call_complete;
564 			}
565 			ASSERTCMP(state, >, AFS_CALL_CL_PROC_REPLY);
566 			goto done;
567 		case -EINPROGRESS:
568 		case -EAGAIN:
569 			goto out;
570 		case -ECONNABORTED:
571 			ASSERTCMP(state, ==, AFS_CALL_COMPLETE);
572 			call->responded = true;
573 			afs_log_error(call, call->abort_code);
574 			goto done;
575 		case -ENOTSUPP:
576 			call->responded = true;
577 			abort_code = RXGEN_OPCODE;
578 			rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
579 						abort_code, ret,
580 						afs_abort_op_not_supported);
581 			goto local_abort;
582 		case -EIO:
583 			pr_err("kAFS: Call %u in bad state %u\n",
584 			       call->debug_id, state);
585 			fallthrough;
586 		case -ENODATA:
587 		case -EBADMSG:
588 		case -EMSGSIZE:
589 		case -ENOMEM:
590 		case -EFAULT:
591 			abort_code = RXGEN_CC_UNMARSHAL;
592 			if (state != AFS_CALL_CL_AWAIT_REPLY)
593 				abort_code = RXGEN_SS_UNMARSHAL;
594 			rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
595 						abort_code, ret,
596 						afs_abort_unmarshal_error);
597 			goto local_abort;
598 		default:
599 			abort_code = RX_CALL_DEAD;
600 			rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
601 						abort_code, ret,
602 						afs_abort_general_error);
603 			goto local_abort;
604 		}
605 	}
606 
607 done:
608 	if (call->type->done)
609 		call->type->done(call);
610 out:
611 	_leave("");
612 	return;
613 
614 local_abort:
615 	abort_code = 0;
616 call_complete:
617 	afs_set_call_complete(call, ret, remote_abort);
618 	goto done;
619 }
620 
621 /*
622  * Wait synchronously for a call to complete.
623  */
624 void afs_wait_for_call_to_complete(struct afs_call *call)
625 {
626 	bool rxrpc_complete = false;
627 
628 	_enter("");
629 
630 	if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {
631 		DECLARE_WAITQUEUE(myself, current);
632 
633 		add_wait_queue(&call->waitq, &myself);
634 		for (;;) {
635 			set_current_state(TASK_UNINTERRUPTIBLE);
636 
637 			/* deliver any messages that are in the queue */
638 			if (!afs_check_call_state(call, AFS_CALL_COMPLETE) &&
639 			    call->need_attention) {
640 				call->need_attention = false;
641 				__set_current_state(TASK_RUNNING);
642 				afs_deliver_to_call(call);
643 				continue;
644 			}
645 
646 			if (afs_check_call_state(call, AFS_CALL_COMPLETE))
647 				break;
648 
649 			if (!rxrpc_kernel_check_life(call->net->socket, call->rxcall)) {
650 				/* rxrpc terminated the call. */
651 				rxrpc_complete = true;
652 				break;
653 			}
654 
655 			schedule();
656 		}
657 
658 		remove_wait_queue(&call->waitq, &myself);
659 		__set_current_state(TASK_RUNNING);
660 	}
661 
662 	if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {
663 		if (rxrpc_complete) {
664 			afs_set_call_complete(call, call->error, call->abort_code);
665 		} else {
666 			/* Kill off the call if it's still live. */
667 			_debug("call interrupted");
668 			if (rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
669 						    RX_USER_ABORT, -EINTR,
670 						    afs_abort_interrupted))
671 				afs_set_call_complete(call, -EINTR, 0);
672 		}
673 	}
674 }
675 
676 /*
677  * wake up a waiting call
678  */
679 static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
680 				    unsigned long call_user_ID)
681 {
682 	struct afs_call *call = (struct afs_call *)call_user_ID;
683 
684 	call->need_attention = true;
685 	wake_up(&call->waitq);
686 }
687 
688 /*
689  * Wake up an asynchronous call.  The caller is holding the call notify
690  * spinlock around this, so we can't call afs_put_call().
691  */
692 static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
693 				   unsigned long call_user_ID)
694 {
695 	struct afs_call *call = (struct afs_call *)call_user_ID;
696 	int r;
697 
698 	trace_afs_notify_call(rxcall, call);
699 	call->need_attention = true;
700 
701 	if (__refcount_inc_not_zero(&call->ref, &r)) {
702 		trace_afs_call(call->debug_id, afs_call_trace_wake, r + 1,
703 			       atomic_read(&call->net->nr_outstanding_calls),
704 			       __builtin_return_address(0));
705 
706 		if (!queue_work(afs_async_calls, &call->async_work))
707 			afs_deferred_put_call(call);
708 	}
709 }
710 
711 /*
712  * Perform I/O processing on an asynchronous call.  The work item carries a ref
713  * to the call struct that we either need to release or to pass on.
714  */
715 static void afs_process_async_call(struct work_struct *work)
716 {
717 	struct afs_call *call = container_of(work, struct afs_call, async_work);
718 
719 	_enter("");
720 
721 	if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
722 		call->need_attention = false;
723 		afs_deliver_to_call(call);
724 	}
725 
726 	afs_put_call(call);
727 	_leave("");
728 }
729 
730 static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
731 {
732 	struct afs_call *call = (struct afs_call *)user_call_ID;
733 
734 	call->rxcall = rxcall;
735 }
736 
737 /*
738  * Charge the incoming call preallocation.
739  */
740 void afs_charge_preallocation(struct work_struct *work)
741 {
742 	struct afs_net *net =
743 		container_of(work, struct afs_net, charge_preallocation_work);
744 	struct afs_call *call = net->spare_incoming_call;
745 
746 	while (READ_ONCE(net->live)) {
747 		if (!call) {
748 			call = afs_alloc_call(net, &afs_RXCMxxxx, GFP_KERNEL);
749 			if (!call)
750 				break;
751 
752 			call->drop_ref = true;
753 			call->async = true;
754 			call->state = AFS_CALL_SV_AWAIT_OP_ID;
755 			init_waitqueue_head(&call->waitq);
756 			afs_extract_to_tmp(call);
757 		}
758 
759 		if (rxrpc_kernel_charge_accept(net->socket,
760 					       afs_wake_up_async_call,
761 					       (unsigned long)call,
762 					       GFP_KERNEL,
763 					       call->debug_id) < 0)
764 			break;
765 		call = NULL;
766 	}
767 	net->spare_incoming_call = call;
768 }
769 
770 /*
771  * Discard a preallocated call when a socket is shut down.
772  */
773 static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
774 				    unsigned long user_call_ID)
775 {
776 	struct afs_call *call = (struct afs_call *)user_call_ID;
777 
778 	call->rxcall = NULL;
779 	afs_put_call(call);
780 }
781 
782 /*
783  * Notification of an incoming call.
784  */
785 static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
786 			    unsigned long user_call_ID)
787 {
788 	struct afs_call *call = (struct afs_call *)user_call_ID;
789 	struct afs_net *net = afs_sock2net(sk);
790 
791 	call->peer = rxrpc_kernel_get_call_peer(sk->sk_socket, call->rxcall);
792 	call->server = afs_find_server(call->peer);
793 	if (!call->server)
794 		trace_afs_cm_no_server(call, rxrpc_kernel_remote_srx(call->peer));
795 
796 	if (net->live)
797 		queue_work(afs_wq, &net->charge_preallocation_work);
798 }
799 
800 /*
801  * Grab the operation ID from an incoming cache manager call.  The socket
802  * buffer is discarded on error or if we don't yet have sufficient data.
803  */
804 static int afs_deliver_cm_op_id(struct afs_call *call)
805 {
806 	int ret;
807 
808 	_enter("{%zu}", iov_iter_count(call->iter));
809 
810 	/* the operation ID forms the first four bytes of the request data */
811 	ret = afs_extract_data(call, true);
812 	if (ret < 0)
813 		return ret;
814 
815 	call->operation_ID = ntohl(call->tmp);
816 	afs_set_call_state(call, AFS_CALL_SV_AWAIT_OP_ID, AFS_CALL_SV_AWAIT_REQUEST);
817 
818 	/* ask the cache manager to route the call (it'll change the call type
819 	 * if successful) */
820 	if (!afs_cm_incoming_call(call))
821 		return -ENOTSUPP;
822 
823 	call->security_ix = rxrpc_kernel_query_call_security(call->rxcall,
824 							     &call->service_id,
825 							     &call->enctype);
826 
827 	trace_afs_cb_call(call);
828 	call->work.func = call->type->work;
829 
830 	/* pass responsibility for the remainder of this message off to the
831 	 * cache manager op */
832 	return call->type->deliver(call);
833 }
834 
835 /*
836  * Advance the AFS call state when an RxRPC service call ends the transmit
837  * phase.
838  */
839 static void afs_notify_end_reply_tx(struct sock *sock,
840 				    struct rxrpc_call *rxcall,
841 				    unsigned long call_user_ID)
842 {
843 	struct afs_call *call = (struct afs_call *)call_user_ID;
844 
845 	afs_set_call_state(call, AFS_CALL_SV_REPLYING, AFS_CALL_SV_AWAIT_ACK);
846 }
847 
848 /*
849  * send an empty reply
850  */
851 void afs_send_empty_reply(struct afs_call *call)
852 {
853 	struct afs_net *net = call->net;
854 	struct msghdr msg;
855 
856 	_enter("");
857 
858 	rxrpc_kernel_set_tx_length(net->socket, call->rxcall, 0);
859 
860 	msg.msg_name		= NULL;
861 	msg.msg_namelen		= 0;
862 	iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, NULL, 0, 0);
863 	msg.msg_control		= NULL;
864 	msg.msg_controllen	= 0;
865 	msg.msg_flags		= 0;
866 
867 	switch (rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, 0,
868 				       afs_notify_end_reply_tx)) {
869 	case 0:
870 		_leave(" [replied]");
871 		return;
872 
873 	case -ENOMEM:
874 		_debug("oom");
875 		rxrpc_kernel_abort_call(net->socket, call->rxcall,
876 					RXGEN_SS_MARSHAL, -ENOMEM,
877 					afs_abort_oom);
878 		fallthrough;
879 	default:
880 		_leave(" [error]");
881 		return;
882 	}
883 }
884 
885 /*
886  * send a simple reply
887  */
888 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
889 {
890 	struct afs_net *net = call->net;
891 	struct msghdr msg;
892 	struct kvec iov[1];
893 	int n;
894 
895 	_enter("");
896 
897 	rxrpc_kernel_set_tx_length(net->socket, call->rxcall, len);
898 
899 	iov[0].iov_base		= (void *) buf;
900 	iov[0].iov_len		= len;
901 	msg.msg_name		= NULL;
902 	msg.msg_namelen		= 0;
903 	iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, iov, 1, len);
904 	msg.msg_control		= NULL;
905 	msg.msg_controllen	= 0;
906 	msg.msg_flags		= 0;
907 
908 	n = rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, len,
909 				   afs_notify_end_reply_tx);
910 	if (n >= 0) {
911 		/* Success */
912 		_leave(" [replied]");
913 		return;
914 	}
915 
916 	if (n == -ENOMEM) {
917 		_debug("oom");
918 		rxrpc_kernel_abort_call(net->socket, call->rxcall,
919 					RXGEN_SS_MARSHAL, -ENOMEM,
920 					afs_abort_oom);
921 	}
922 	_leave(" [error]");
923 }
924 
925 /*
926  * Extract a piece of data from the received data socket buffers.
927  */
928 int afs_extract_data(struct afs_call *call, bool want_more)
929 {
930 	struct afs_net *net = call->net;
931 	struct iov_iter *iter = call->iter;
932 	enum afs_call_state state;
933 	u32 remote_abort = 0;
934 	int ret;
935 
936 	_enter("{%s,%zu,%zu},%d",
937 	       call->type->name, call->iov_len, iov_iter_count(iter), want_more);
938 
939 	ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, iter,
940 				     &call->iov_len, want_more, &remote_abort,
941 				     &call->service_id);
942 	trace_afs_receive_data(call, call->iter, want_more, ret);
943 	if (ret == 0 || ret == -EAGAIN)
944 		return ret;
945 
946 	state = READ_ONCE(call->state);
947 	if (ret == 1) {
948 		switch (state) {
949 		case AFS_CALL_CL_AWAIT_REPLY:
950 			afs_set_call_state(call, state, AFS_CALL_CL_PROC_REPLY);
951 			break;
952 		case AFS_CALL_SV_AWAIT_REQUEST:
953 			afs_set_call_state(call, state, AFS_CALL_SV_REPLYING);
954 			break;
955 		case AFS_CALL_COMPLETE:
956 			kdebug("prem complete %d", call->error);
957 			return afs_io_error(call, afs_io_error_extract);
958 		default:
959 			break;
960 		}
961 		return 0;
962 	}
963 
964 	afs_set_call_complete(call, ret, remote_abort);
965 	return ret;
966 }
967 
968 /*
969  * Log protocol error production.
970  */
971 noinline int afs_protocol_error(struct afs_call *call,
972 				enum afs_eproto_cause cause)
973 {
974 	trace_afs_protocol_error(call, cause);
975 	if (call)
976 		call->unmarshalling_error = true;
977 	return -EBADMSG;
978 }
979 
980 /*
981  * Wake up OOB notification processing.
982  */
983 static void afs_rx_notify_oob(struct sock *sk, struct sk_buff *oob)
984 {
985 	struct afs_net *net = sk->sk_user_data;
986 
987 	schedule_work(&net->rx_oob_work);
988 }
989