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brintos / linux-shallow public Read only

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1// SPDX-License-Identifier: GPL-2.0-or-later2/* Maintain an RxRPC server socket to do AFS communications through3 *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_ENUMS17#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 int afs_deliver_cm_op_id(struct afs_call *);28 29/* asynchronous incoming call initial processing */30static const struct afs_call_type afs_RXCMxxxx = {31	.name		= "CB.xxxx",32	.deliver	= afs_deliver_cm_op_id,33};34 35/*36 * open an RxRPC socket and bind it to be a server for callback notifications37 * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT38 */39int afs_open_socket(struct afs_net *net)40{41	struct sockaddr_rxrpc srx;42	struct socket *socket;43	int ret;44 45	_enter("");46 47	ret = sock_create_kern(net->net, AF_RXRPC, SOCK_DGRAM, PF_INET6, &socket);48	if (ret < 0)49		goto error_1;50 51	socket->sk->sk_allocation = GFP_NOFS;52 53	/* bind the callback manager's address to make this a server socket */54	memset(&srx, 0, sizeof(srx));55	srx.srx_family			= AF_RXRPC;56	srx.srx_service			= CM_SERVICE;57	srx.transport_type		= SOCK_DGRAM;58	srx.transport_len		= sizeof(srx.transport.sin6);59	srx.transport.sin6.sin6_family	= AF_INET6;60	srx.transport.sin6.sin6_port	= htons(AFS_CM_PORT);61 62	ret = rxrpc_sock_set_min_security_level(socket->sk,63						RXRPC_SECURITY_ENCRYPT);64	if (ret < 0)65		goto error_2;66 67	ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));68	if (ret == -EADDRINUSE) {69		srx.transport.sin6.sin6_port = 0;70		ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));71	}72	if (ret < 0)73		goto error_2;74 75	srx.srx_service = YFS_CM_SERVICE;76	ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));77	if (ret < 0)78		goto error_2;79 80	/* Ideally, we'd turn on service upgrade here, but we can't because81	 * OpenAFS is buggy and leaks the userStatus field from packet to82	 * packet and between FS packets and CB packets - so if we try to do an83	 * upgrade on an FS packet, OpenAFS will leak that into the CB packet84	 * it sends back to us.85	 */86 87	rxrpc_kernel_new_call_notification(socket, afs_rx_new_call,88					   afs_rx_discard_new_call);89 90	ret = kernel_listen(socket, INT_MAX);91	if (ret < 0)92		goto error_2;93 94	net->socket = socket;95	afs_charge_preallocation(&net->charge_preallocation_work);96	_leave(" = 0");97	return 0;98 99error_2:100	sock_release(socket);101error_1:102	_leave(" = %d", ret);103	return ret;104}105 106/*107 * close the RxRPC socket AFS was using108 */109void afs_close_socket(struct afs_net *net)110{111	_enter("");112 113	kernel_listen(net->socket, 0);114	flush_workqueue(afs_async_calls);115 116	if (net->spare_incoming_call) {117		afs_put_call(net->spare_incoming_call);118		net->spare_incoming_call = NULL;119	}120 121	_debug("outstanding %u", atomic_read(&net->nr_outstanding_calls));122	wait_var_event(&net->nr_outstanding_calls,123		       !atomic_read(&net->nr_outstanding_calls));124	_debug("no outstanding calls");125 126	kernel_sock_shutdown(net->socket, SHUT_RDWR);127	flush_workqueue(afs_async_calls);128	sock_release(net->socket);129 130	_debug("dework");131	_leave("");132}133 134/*135 * Allocate a call.136 */137static struct afs_call *afs_alloc_call(struct afs_net *net,138				       const struct afs_call_type *type,139				       gfp_t gfp)140{141	struct afs_call *call;142	int o;143 144	call = kzalloc(sizeof(*call), gfp);145	if (!call)146		return NULL;147 148	call->type = type;149	call->net = net;150	call->debug_id = atomic_inc_return(&rxrpc_debug_id);151	refcount_set(&call->ref, 1);152	INIT_WORK(&call->async_work, afs_process_async_call);153	INIT_WORK(&call->free_work, afs_deferred_free_worker);154	init_waitqueue_head(&call->waitq);155	spin_lock_init(&call->state_lock);156	call->iter = &call->def_iter;157 158	o = atomic_inc_return(&net->nr_outstanding_calls);159	trace_afs_call(call->debug_id, afs_call_trace_alloc, 1, o,160		       __builtin_return_address(0));161	return call;162}163 164static void afs_free_call(struct afs_call *call)165{166	struct afs_net *net = call->net;167	int o;168 169	ASSERT(!work_pending(&call->async_work));170 171	rxrpc_kernel_put_peer(call->peer);172 173	if (call->rxcall) {174		rxrpc_kernel_shutdown_call(net->socket, call->rxcall);175		rxrpc_kernel_put_call(net->socket, call->rxcall);176		call->rxcall = NULL;177	}178	if (call->type->destructor)179		call->type->destructor(call);180 181	afs_unuse_server_notime(call->net, call->server, afs_server_trace_put_call);182	kfree(call->request);183 184	o = atomic_read(&net->nr_outstanding_calls);185	trace_afs_call(call->debug_id, afs_call_trace_free, 0, o,186		       __builtin_return_address(0));187	kfree(call);188 189	o = atomic_dec_return(&net->nr_outstanding_calls);190	if (o == 0)191		wake_up_var(&net->nr_outstanding_calls);192}193 194/*195 * Dispose of a reference on a call.196 */197void afs_put_call(struct afs_call *call)198{199	struct afs_net *net = call->net;200	unsigned int debug_id = call->debug_id;201	bool zero;202	int r, o;203 204	zero = __refcount_dec_and_test(&call->ref, &r);205	o = atomic_read(&net->nr_outstanding_calls);206	trace_afs_call(debug_id, afs_call_trace_put, r - 1, o,207		       __builtin_return_address(0));208	if (zero)209		afs_free_call(call);210}211 212static void afs_deferred_free_worker(struct work_struct *work)213{214	struct afs_call *call = container_of(work, struct afs_call, free_work);215 216	afs_free_call(call);217}218 219/*220 * Dispose of a reference on a call, deferring the cleanup to a workqueue221 * to avoid lock recursion.222 */223void afs_deferred_put_call(struct afs_call *call)224{225	struct afs_net *net = call->net;226	unsigned int debug_id = call->debug_id;227	bool zero;228	int r, o;229 230	zero = __refcount_dec_and_test(&call->ref, &r);231	o = atomic_read(&net->nr_outstanding_calls);232	trace_afs_call(debug_id, afs_call_trace_put, r - 1, o,233		       __builtin_return_address(0));234	if (zero)235		schedule_work(&call->free_work);236}237 238static struct afs_call *afs_get_call(struct afs_call *call,239				     enum afs_call_trace why)240{241	int r;242 243	__refcount_inc(&call->ref, &r);244 245	trace_afs_call(call->debug_id, why, r + 1,246		       atomic_read(&call->net->nr_outstanding_calls),247		       __builtin_return_address(0));248	return call;249}250 251/*252 * Queue the call for actual work.253 */254static void afs_queue_call_work(struct afs_call *call)255{256	if (call->type->work) {257		INIT_WORK(&call->work, call->type->work);258 259		afs_get_call(call, afs_call_trace_work);260		if (!queue_work(afs_wq, &call->work))261			afs_put_call(call);262	}263}264 265/*266 * allocate a call with flat request and reply buffers267 */268struct afs_call *afs_alloc_flat_call(struct afs_net *net,269				     const struct afs_call_type *type,270				     size_t request_size, size_t reply_max)271{272	struct afs_call *call;273 274	call = afs_alloc_call(net, type, GFP_NOFS);275	if (!call)276		goto nomem_call;277 278	if (request_size) {279		call->request_size = request_size;280		call->request = kmalloc(request_size, GFP_NOFS);281		if (!call->request)282			goto nomem_free;283	}284 285	if (reply_max) {286		call->reply_max = reply_max;287		call->buffer = kmalloc(reply_max, GFP_NOFS);288		if (!call->buffer)289			goto nomem_free;290	}291 292	afs_extract_to_buf(call, call->reply_max);293	call->operation_ID = type->op;294	init_waitqueue_head(&call->waitq);295	return call;296 297nomem_free:298	afs_put_call(call);299nomem_call:300	return NULL;301}302 303/*304 * clean up a call with flat buffer305 */306void afs_flat_call_destructor(struct afs_call *call)307{308	_enter("");309 310	kfree(call->request);311	call->request = NULL;312	kfree(call->buffer);313	call->buffer = NULL;314}315 316/*317 * Advance the AFS call state when the RxRPC call ends the transmit phase.318 */319static void afs_notify_end_request_tx(struct sock *sock,320				      struct rxrpc_call *rxcall,321				      unsigned long call_user_ID)322{323	struct afs_call *call = (struct afs_call *)call_user_ID;324 325	afs_set_call_state(call, AFS_CALL_CL_REQUESTING, AFS_CALL_CL_AWAIT_REPLY);326}327 328/*329 * Initiate a call and synchronously queue up the parameters for dispatch.  Any330 * error is stored into the call struct, which the caller must check for.331 */332void afs_make_call(struct afs_call *call, gfp_t gfp)333{334	struct rxrpc_call *rxcall;335	struct msghdr msg;336	struct kvec iov[1];337	size_t len;338	s64 tx_total_len;339	int ret;340 341	_enter(",{%pISp+%u},", rxrpc_kernel_remote_addr(call->peer), call->service_id);342 343	ASSERT(call->type != NULL);344	ASSERT(call->type->name != NULL);345 346	_debug("____MAKE %p{%s,%x} [%d]____",347	       call, call->type->name, key_serial(call->key),348	       atomic_read(&call->net->nr_outstanding_calls));349 350	trace_afs_make_call(call);351 352	/* Work out the length we're going to transmit.  This is awkward for353	 * calls such as FS.StoreData where there's an extra injection of data354	 * after the initial fixed part.355	 */356	tx_total_len = call->request_size;357	if (call->write_iter)358		tx_total_len += iov_iter_count(call->write_iter);359 360	/* If the call is going to be asynchronous, we need an extra ref for361	 * the call to hold itself so the caller need not hang on to its ref.362	 */363	if (call->async) {364		afs_get_call(call, afs_call_trace_get);365		call->drop_ref = true;366	}367 368	/* create a call */369	rxcall = rxrpc_kernel_begin_call(call->net->socket, call->peer, call->key,370					 (unsigned long)call,371					 tx_total_len,372					 call->max_lifespan,373					 gfp,374					 (call->async ?375					  afs_wake_up_async_call :376					  afs_wake_up_call_waiter),377					 call->service_id,378					 call->upgrade,379					 (call->intr ? RXRPC_PREINTERRUPTIBLE :380					  RXRPC_UNINTERRUPTIBLE),381					 call->debug_id);382	if (IS_ERR(rxcall)) {383		ret = PTR_ERR(rxcall);384		call->error = ret;385		goto error_kill_call;386	}387 388	call->rxcall = rxcall;389	call->issue_time = ktime_get_real();390 391	/* send the request */392	iov[0].iov_base	= call->request;393	iov[0].iov_len	= call->request_size;394 395	msg.msg_name		= NULL;396	msg.msg_namelen		= 0;397	iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, iov, 1, call->request_size);398	msg.msg_control		= NULL;399	msg.msg_controllen	= 0;400	msg.msg_flags		= MSG_WAITALL | (call->write_iter ? MSG_MORE : 0);401 402	ret = rxrpc_kernel_send_data(call->net->socket, rxcall,403				     &msg, call->request_size,404				     afs_notify_end_request_tx);405	if (ret < 0)406		goto error_do_abort;407 408	if (call->write_iter) {409		msg.msg_iter = *call->write_iter;410		msg.msg_flags &= ~MSG_MORE;411		trace_afs_send_data(call, &msg);412 413		ret = rxrpc_kernel_send_data(call->net->socket,414					     call->rxcall, &msg,415					     iov_iter_count(&msg.msg_iter),416					     afs_notify_end_request_tx);417		*call->write_iter = msg.msg_iter;418 419		trace_afs_sent_data(call, &msg, ret);420		if (ret < 0)421			goto error_do_abort;422	}423 424	/* Note that at this point, we may have received the reply or an abort425	 * - and an asynchronous call may already have completed.426	 *427	 * afs_wait_for_call_to_complete(call)428	 * must be called to synchronously clean up.429	 */430	return;431 432error_do_abort:433	if (ret != -ECONNABORTED) {434		rxrpc_kernel_abort_call(call->net->socket, rxcall,435					RX_USER_ABORT, ret,436					afs_abort_send_data_error);437	} else {438		len = 0;439		iov_iter_kvec(&msg.msg_iter, ITER_DEST, NULL, 0, 0);440		rxrpc_kernel_recv_data(call->net->socket, rxcall,441				       &msg.msg_iter, &len, false,442				       &call->abort_code, &call->service_id);443		call->responded = true;444	}445	call->error = ret;446	trace_afs_call_done(call);447error_kill_call:448	if (call->type->done)449		call->type->done(call);450 451	/* We need to dispose of the extra ref we grabbed for an async call.452	 * The call, however, might be queued on afs_async_calls and we need to453	 * make sure we don't get any more notifications that might requeue it.454	 */455	if (call->rxcall)456		rxrpc_kernel_shutdown_call(call->net->socket, call->rxcall);457	if (call->async) {458		if (cancel_work_sync(&call->async_work))459			afs_put_call(call);460		afs_set_call_complete(call, ret, 0);461	}462 463	call->error = ret;464	call->state = AFS_CALL_COMPLETE;465	_leave(" = %d", ret);466}467 468/*469 * Log remote abort codes that indicate that we have a protocol disagreement470 * with the server.471 */472static void afs_log_error(struct afs_call *call, s32 remote_abort)473{474	static int max = 0;475	const char *msg;476	int m;477 478	switch (remote_abort) {479	case RX_EOF:		 msg = "unexpected EOF";	break;480	case RXGEN_CC_MARSHAL:	 msg = "client marshalling";	break;481	case RXGEN_CC_UNMARSHAL: msg = "client unmarshalling";	break;482	case RXGEN_SS_MARSHAL:	 msg = "server marshalling";	break;483	case RXGEN_SS_UNMARSHAL: msg = "server unmarshalling";	break;484	case RXGEN_DECODE:	 msg = "opcode decode";		break;485	case RXGEN_SS_XDRFREE:	 msg = "server XDR cleanup";	break;486	case RXGEN_CC_XDRFREE:	 msg = "client XDR cleanup";	break;487	case -32:		 msg = "insufficient data";	break;488	default:489		return;490	}491 492	m = max;493	if (m < 3) {494		max = m + 1;495		pr_notice("kAFS: Peer reported %s failure on %s [%pISp]\n",496			  msg, call->type->name,497			  rxrpc_kernel_remote_addr(call->peer));498	}499}500 501/*502 * deliver messages to a call503 */504static void afs_deliver_to_call(struct afs_call *call)505{506	enum afs_call_state state;507	size_t len;508	u32 abort_code, remote_abort = 0;509	int ret;510 511	_enter("%s", call->type->name);512 513	while (state = READ_ONCE(call->state),514	       state == AFS_CALL_CL_AWAIT_REPLY ||515	       state == AFS_CALL_SV_AWAIT_OP_ID ||516	       state == AFS_CALL_SV_AWAIT_REQUEST ||517	       state == AFS_CALL_SV_AWAIT_ACK518	       ) {519		if (state == AFS_CALL_SV_AWAIT_ACK) {520			len = 0;521			iov_iter_kvec(&call->def_iter, ITER_DEST, NULL, 0, 0);522			ret = rxrpc_kernel_recv_data(call->net->socket,523						     call->rxcall, &call->def_iter,524						     &len, false, &remote_abort,525						     &call->service_id);526			trace_afs_receive_data(call, &call->def_iter, false, ret);527 528			if (ret == -EINPROGRESS || ret == -EAGAIN)529				return;530			if (ret < 0 || ret == 1) {531				if (ret == 1)532					ret = 0;533				goto call_complete;534			}535			return;536		}537 538		ret = call->type->deliver(call);539		state = READ_ONCE(call->state);540		if (ret == 0 && call->unmarshalling_error)541			ret = -EBADMSG;542		switch (ret) {543		case 0:544			call->responded = true;545			afs_queue_call_work(call);546			if (state == AFS_CALL_CL_PROC_REPLY) {547				if (call->op)548					set_bit(AFS_SERVER_FL_MAY_HAVE_CB,549						&call->op->server->flags);550				goto call_complete;551			}552			ASSERTCMP(state, >, AFS_CALL_CL_PROC_REPLY);553			goto done;554		case -EINPROGRESS:555		case -EAGAIN:556			goto out;557		case -ECONNABORTED:558			ASSERTCMP(state, ==, AFS_CALL_COMPLETE);559			call->responded = true;560			afs_log_error(call, call->abort_code);561			goto done;562		case -ENOTSUPP:563			call->responded = true;564			abort_code = RXGEN_OPCODE;565			rxrpc_kernel_abort_call(call->net->socket, call->rxcall,566						abort_code, ret,567						afs_abort_op_not_supported);568			goto local_abort;569		case -EIO:570			pr_err("kAFS: Call %u in bad state %u\n",571			       call->debug_id, state);572			fallthrough;573		case -ENODATA:574		case -EBADMSG:575		case -EMSGSIZE:576		case -ENOMEM:577		case -EFAULT:578			abort_code = RXGEN_CC_UNMARSHAL;579			if (state != AFS_CALL_CL_AWAIT_REPLY)580				abort_code = RXGEN_SS_UNMARSHAL;581			rxrpc_kernel_abort_call(call->net->socket, call->rxcall,582						abort_code, ret,583						afs_abort_unmarshal_error);584			goto local_abort;585		default:586			abort_code = RX_CALL_DEAD;587			rxrpc_kernel_abort_call(call->net->socket, call->rxcall,588						abort_code, ret,589						afs_abort_general_error);590			goto local_abort;591		}592	}593 594done:595	if (call->type->done)596		call->type->done(call);597out:598	_leave("");599	return;600 601local_abort:602	abort_code = 0;603call_complete:604	afs_set_call_complete(call, ret, remote_abort);605	state = AFS_CALL_COMPLETE;606	goto done;607}608 609/*610 * Wait synchronously for a call to complete.611 */612void afs_wait_for_call_to_complete(struct afs_call *call)613{614	bool rxrpc_complete = false;615 616	_enter("");617 618	if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {619		DECLARE_WAITQUEUE(myself, current);620 621		add_wait_queue(&call->waitq, &myself);622		for (;;) {623			set_current_state(TASK_UNINTERRUPTIBLE);624 625			/* deliver any messages that are in the queue */626			if (!afs_check_call_state(call, AFS_CALL_COMPLETE) &&627			    call->need_attention) {628				call->need_attention = false;629				__set_current_state(TASK_RUNNING);630				afs_deliver_to_call(call);631				continue;632			}633 634			if (afs_check_call_state(call, AFS_CALL_COMPLETE))635				break;636 637			if (!rxrpc_kernel_check_life(call->net->socket, call->rxcall)) {638				/* rxrpc terminated the call. */639				rxrpc_complete = true;640				break;641			}642 643			schedule();644		}645 646		remove_wait_queue(&call->waitq, &myself);647		__set_current_state(TASK_RUNNING);648	}649 650	if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {651		if (rxrpc_complete) {652			afs_set_call_complete(call, call->error, call->abort_code);653		} else {654			/* Kill off the call if it's still live. */655			_debug("call interrupted");656			if (rxrpc_kernel_abort_call(call->net->socket, call->rxcall,657						    RX_USER_ABORT, -EINTR,658						    afs_abort_interrupted))659				afs_set_call_complete(call, -EINTR, 0);660		}661	}662}663 664/*665 * wake up a waiting call666 */667static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,668				    unsigned long call_user_ID)669{670	struct afs_call *call = (struct afs_call *)call_user_ID;671 672	call->need_attention = true;673	wake_up(&call->waitq);674}675 676/*677 * Wake up an asynchronous call.  The caller is holding the call notify678 * spinlock around this, so we can't call afs_put_call().679 */680static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,681				   unsigned long call_user_ID)682{683	struct afs_call *call = (struct afs_call *)call_user_ID;684	int r;685 686	trace_afs_notify_call(rxcall, call);687	call->need_attention = true;688 689	if (__refcount_inc_not_zero(&call->ref, &r)) {690		trace_afs_call(call->debug_id, afs_call_trace_wake, r + 1,691			       atomic_read(&call->net->nr_outstanding_calls),692			       __builtin_return_address(0));693 694		if (!queue_work(afs_async_calls, &call->async_work))695			afs_deferred_put_call(call);696	}697}698 699/*700 * Perform I/O processing on an asynchronous call.  The work item carries a ref701 * to the call struct that we either need to release or to pass on.702 */703static void afs_process_async_call(struct work_struct *work)704{705	struct afs_call *call = container_of(work, struct afs_call, async_work);706 707	_enter("");708 709	if (call->state < AFS_CALL_COMPLETE && call->need_attention) {710		call->need_attention = false;711		afs_deliver_to_call(call);712	}713 714	afs_put_call(call);715	_leave("");716}717 718static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)719{720	struct afs_call *call = (struct afs_call *)user_call_ID;721 722	call->rxcall = rxcall;723}724 725/*726 * Charge the incoming call preallocation.727 */728void afs_charge_preallocation(struct work_struct *work)729{730	struct afs_net *net =731		container_of(work, struct afs_net, charge_preallocation_work);732	struct afs_call *call = net->spare_incoming_call;733 734	for (;;) {735		if (!call) {736			call = afs_alloc_call(net, &afs_RXCMxxxx, GFP_KERNEL);737			if (!call)738				break;739 740			call->drop_ref = true;741			call->async = true;742			call->state = AFS_CALL_SV_AWAIT_OP_ID;743			init_waitqueue_head(&call->waitq);744			afs_extract_to_tmp(call);745		}746 747		if (rxrpc_kernel_charge_accept(net->socket,748					       afs_wake_up_async_call,749					       afs_rx_attach,750					       (unsigned long)call,751					       GFP_KERNEL,752					       call->debug_id) < 0)753			break;754		call = NULL;755	}756	net->spare_incoming_call = call;757}758 759/*760 * Discard a preallocated call when a socket is shut down.761 */762static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,763				    unsigned long user_call_ID)764{765	struct afs_call *call = (struct afs_call *)user_call_ID;766 767	call->rxcall = NULL;768	afs_put_call(call);769}770 771/*772 * Notification of an incoming call.773 */774static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,775			    unsigned long user_call_ID)776{777	struct afs_net *net = afs_sock2net(sk);778 779	queue_work(afs_wq, &net->charge_preallocation_work);780}781 782/*783 * Grab the operation ID from an incoming cache manager call.  The socket784 * buffer is discarded on error or if we don't yet have sufficient data.785 */786static int afs_deliver_cm_op_id(struct afs_call *call)787{788	int ret;789 790	_enter("{%zu}", iov_iter_count(call->iter));791 792	/* the operation ID forms the first four bytes of the request data */793	ret = afs_extract_data(call, true);794	if (ret < 0)795		return ret;796 797	call->operation_ID = ntohl(call->tmp);798	afs_set_call_state(call, AFS_CALL_SV_AWAIT_OP_ID, AFS_CALL_SV_AWAIT_REQUEST);799 800	/* ask the cache manager to route the call (it'll change the call type801	 * if successful) */802	if (!afs_cm_incoming_call(call))803		return -ENOTSUPP;804 805	trace_afs_cb_call(call);806 807	/* pass responsibility for the remainer of this message off to the808	 * cache manager op */809	return call->type->deliver(call);810}811 812/*813 * Advance the AFS call state when an RxRPC service call ends the transmit814 * phase.815 */816static void afs_notify_end_reply_tx(struct sock *sock,817				    struct rxrpc_call *rxcall,818				    unsigned long call_user_ID)819{820	struct afs_call *call = (struct afs_call *)call_user_ID;821 822	afs_set_call_state(call, AFS_CALL_SV_REPLYING, AFS_CALL_SV_AWAIT_ACK);823}824 825/*826 * send an empty reply827 */828void afs_send_empty_reply(struct afs_call *call)829{830	struct afs_net *net = call->net;831	struct msghdr msg;832 833	_enter("");834 835	rxrpc_kernel_set_tx_length(net->socket, call->rxcall, 0);836 837	msg.msg_name		= NULL;838	msg.msg_namelen		= 0;839	iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, NULL, 0, 0);840	msg.msg_control		= NULL;841	msg.msg_controllen	= 0;842	msg.msg_flags		= 0;843 844	switch (rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, 0,845				       afs_notify_end_reply_tx)) {846	case 0:847		_leave(" [replied]");848		return;849 850	case -ENOMEM:851		_debug("oom");852		rxrpc_kernel_abort_call(net->socket, call->rxcall,853					RXGEN_SS_MARSHAL, -ENOMEM,854					afs_abort_oom);855		fallthrough;856	default:857		_leave(" [error]");858		return;859	}860}861 862/*863 * send a simple reply864 */865void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)866{867	struct afs_net *net = call->net;868	struct msghdr msg;869	struct kvec iov[1];870	int n;871 872	_enter("");873 874	rxrpc_kernel_set_tx_length(net->socket, call->rxcall, len);875 876	iov[0].iov_base		= (void *) buf;877	iov[0].iov_len		= len;878	msg.msg_name		= NULL;879	msg.msg_namelen		= 0;880	iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, iov, 1, len);881	msg.msg_control		= NULL;882	msg.msg_controllen	= 0;883	msg.msg_flags		= 0;884 885	n = rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, len,886				   afs_notify_end_reply_tx);887	if (n >= 0) {888		/* Success */889		_leave(" [replied]");890		return;891	}892 893	if (n == -ENOMEM) {894		_debug("oom");895		rxrpc_kernel_abort_call(net->socket, call->rxcall,896					RXGEN_SS_MARSHAL, -ENOMEM,897					afs_abort_oom);898	}899	_leave(" [error]");900}901 902/*903 * Extract a piece of data from the received data socket buffers.904 */905int afs_extract_data(struct afs_call *call, bool want_more)906{907	struct afs_net *net = call->net;908	struct iov_iter *iter = call->iter;909	enum afs_call_state state;910	u32 remote_abort = 0;911	int ret;912 913	_enter("{%s,%zu,%zu},%d",914	       call->type->name, call->iov_len, iov_iter_count(iter), want_more);915 916	ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, iter,917				     &call->iov_len, want_more, &remote_abort,918				     &call->service_id);919	trace_afs_receive_data(call, call->iter, want_more, ret);920	if (ret == 0 || ret == -EAGAIN)921		return ret;922 923	state = READ_ONCE(call->state);924	if (ret == 1) {925		switch (state) {926		case AFS_CALL_CL_AWAIT_REPLY:927			afs_set_call_state(call, state, AFS_CALL_CL_PROC_REPLY);928			break;929		case AFS_CALL_SV_AWAIT_REQUEST:930			afs_set_call_state(call, state, AFS_CALL_SV_REPLYING);931			break;932		case AFS_CALL_COMPLETE:933			kdebug("prem complete %d", call->error);934			return afs_io_error(call, afs_io_error_extract);935		default:936			break;937		}938		return 0;939	}940 941	afs_set_call_complete(call, ret, remote_abort);942	return ret;943}944 945/*946 * Log protocol error production.947 */948noinline int afs_protocol_error(struct afs_call *call,949				enum afs_eproto_cause cause)950{951	trace_afs_protocol_error(call, cause);952	if (call)953		call->unmarshalling_error = true;954	return -EBADMSG;955}956