rxrpc.c

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