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  1/* Maintain an RxRPC server socket to do AFS communications through
  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#include <linux/slab.h>
 13#include <net/sock.h>
 14#include <net/af_rxrpc.h>
 15#include <rxrpc/packet.h>
 16#include "internal.h"
 17#include "afs_cm.h"
 18
 19static struct socket *afs_socket; /* my RxRPC socket */
 20static struct workqueue_struct *afs_async_calls;
 21static atomic_t afs_outstanding_calls;
 22static atomic_t afs_outstanding_skbs;
 23
 24static void afs_wake_up_call_waiter(struct afs_call *);
 25static int afs_wait_for_call_to_complete(struct afs_call *);
 26static void afs_wake_up_async_call(struct afs_call *);
 27static int afs_dont_wait_for_call_to_complete(struct afs_call *);
 28static void afs_process_async_call(struct work_struct *);
 29static void afs_rx_interceptor(struct sock *, unsigned long, struct sk_buff *);
 30static int afs_deliver_cm_op_id(struct afs_call *, struct sk_buff *, bool);
 31
 32/* synchronous call management */
 33const struct afs_wait_mode afs_sync_call = {
 34	.rx_wakeup	= afs_wake_up_call_waiter,
 35	.wait		= afs_wait_for_call_to_complete,
 36};
 37
 38/* asynchronous call management */
 39const struct afs_wait_mode afs_async_call = {
 40	.rx_wakeup	= afs_wake_up_async_call,
 41	.wait		= afs_dont_wait_for_call_to_complete,
 42};
 43
 44/* asynchronous incoming call management */
 45static const struct afs_wait_mode afs_async_incoming_call = {
 46	.rx_wakeup	= afs_wake_up_async_call,
 47};
 48
 49/* asynchronous incoming call initial processing */
 50static const struct afs_call_type afs_RXCMxxxx = {
 51	.name		= "CB.xxxx",
 52	.deliver	= afs_deliver_cm_op_id,
 53	.abort_to_error	= afs_abort_to_error,
 54};
 55
 56static void afs_collect_incoming_call(struct work_struct *);
 57
 58static struct sk_buff_head afs_incoming_calls;
 59static DECLARE_WORK(afs_collect_incoming_call_work, afs_collect_incoming_call);
 60
 61/*
 62 * open an RxRPC socket and bind it to be a server for callback notifications
 63 * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
 64 */
 65int afs_open_socket(void)
 66{
 67	struct sockaddr_rxrpc srx;
 68	struct socket *socket;
 69	int ret;
 70
 71	_enter("");
 72
 73	skb_queue_head_init(&afs_incoming_calls);
 74
 75	afs_async_calls = create_singlethread_workqueue("kafsd");
 76	if (!afs_async_calls) {
 77		_leave(" = -ENOMEM [wq]");
 78		return -ENOMEM;
 79	}
 80
 81	ret = sock_create_kern(AF_RXRPC, SOCK_DGRAM, PF_INET, &socket);
 82	if (ret < 0) {
 83		destroy_workqueue(afs_async_calls);
 84		_leave(" = %d [socket]", ret);
 85		return ret;
 86	}
 87
 88	socket->sk->sk_allocation = GFP_NOFS;
 89
 90	/* bind the callback manager's address to make this a server socket */
 91	srx.srx_family			= AF_RXRPC;
 92	srx.srx_service			= CM_SERVICE;
 93	srx.transport_type		= SOCK_DGRAM;
 94	srx.transport_len		= sizeof(srx.transport.sin);
 95	srx.transport.sin.sin_family	= AF_INET;
 96	srx.transport.sin.sin_port	= htons(AFS_CM_PORT);
 97	memset(&srx.transport.sin.sin_addr, 0,
 98	       sizeof(srx.transport.sin.sin_addr));
 99
100	ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
101	if (ret < 0) {
102		sock_release(socket);
103		destroy_workqueue(afs_async_calls);
104		_leave(" = %d [bind]", ret);
105		return ret;
106	}
107
108	rxrpc_kernel_intercept_rx_messages(socket, afs_rx_interceptor);
109
110	afs_socket = socket;
111	_leave(" = 0");
112	return 0;
113}
114
115/*
116 * close the RxRPC socket AFS was using
117 */
118void afs_close_socket(void)
119{
120	_enter("");
121
122	sock_release(afs_socket);
123
124	_debug("dework");
125	destroy_workqueue(afs_async_calls);
126
127	ASSERTCMP(atomic_read(&afs_outstanding_skbs), ==, 0);
128	ASSERTCMP(atomic_read(&afs_outstanding_calls), ==, 0);
129	_leave("");
130}
131
132/*
133 * note that the data in a socket buffer is now delivered and that the buffer
134 * should be freed
135 */
136static void afs_data_delivered(struct sk_buff *skb)
137{
138	if (!skb) {
139		_debug("DLVR NULL [%d]", atomic_read(&afs_outstanding_skbs));
140		dump_stack();
141	} else {
142		_debug("DLVR %p{%u} [%d]",
143		       skb, skb->mark, atomic_read(&afs_outstanding_skbs));
144		if (atomic_dec_return(&afs_outstanding_skbs) == -1)
145			BUG();
146		rxrpc_kernel_data_delivered(skb);
147	}
148}
149
150/*
151 * free a socket buffer
152 */
153static void afs_free_skb(struct sk_buff *skb)
154{
155	if (!skb) {
156		_debug("FREE NULL [%d]", atomic_read(&afs_outstanding_skbs));
157		dump_stack();
158	} else {
159		_debug("FREE %p{%u} [%d]",
160		       skb, skb->mark, atomic_read(&afs_outstanding_skbs));
161		if (atomic_dec_return(&afs_outstanding_skbs) == -1)
162			BUG();
163		rxrpc_kernel_free_skb(skb);
164	}
165}
166
167/*
168 * free a call
169 */
170static void afs_free_call(struct afs_call *call)
171{
172	_debug("DONE %p{%s} [%d]",
173	       call, call->type->name, atomic_read(&afs_outstanding_calls));
174	if (atomic_dec_return(&afs_outstanding_calls) == -1)
175		BUG();
176
177	ASSERTCMP(call->rxcall, ==, NULL);
178	ASSERT(!work_pending(&call->async_work));
179	ASSERT(skb_queue_empty(&call->rx_queue));
180	ASSERT(call->type->name != NULL);
181
182	kfree(call->request);
183	kfree(call);
184}
185
186/*
187 * allocate a call with flat request and reply buffers
188 */
189struct afs_call *afs_alloc_flat_call(const struct afs_call_type *type,
190				     size_t request_size, size_t reply_size)
191{
192	struct afs_call *call;
193
194	call = kzalloc(sizeof(*call), GFP_NOFS);
195	if (!call)
196		goto nomem_call;
197
198	_debug("CALL %p{%s} [%d]",
199	       call, type->name, atomic_read(&afs_outstanding_calls));
200	atomic_inc(&afs_outstanding_calls);
201
202	call->type = type;
203	call->request_size = request_size;
204	call->reply_max = reply_size;
205
206	if (request_size) {
207		call->request = kmalloc(request_size, GFP_NOFS);
208		if (!call->request)
209			goto nomem_free;
210	}
211
212	if (reply_size) {
213		call->buffer = kmalloc(reply_size, GFP_NOFS);
214		if (!call->buffer)
215			goto nomem_free;
216	}
217
218	init_waitqueue_head(&call->waitq);
219	skb_queue_head_init(&call->rx_queue);
220	return call;
221
222nomem_free:
223	afs_free_call(call);
224nomem_call:
225	return NULL;
226}
227
228/*
229 * clean up a call with flat buffer
230 */
231void afs_flat_call_destructor(struct afs_call *call)
232{
233	_enter("");
234
235	kfree(call->request);
236	call->request = NULL;
237	kfree(call->buffer);
238	call->buffer = NULL;
239}
240
241/*
242 * attach the data from a bunch of pages on an inode to a call
243 */
244static int afs_send_pages(struct afs_call *call, struct msghdr *msg,
245			  struct kvec *iov)
246{
247	struct page *pages[8];
248	unsigned count, n, loop, offset, to;
249	pgoff_t first = call->first, last = call->last;
250	int ret;
251
252	_enter("");
253
254	offset = call->first_offset;
255	call->first_offset = 0;
256
257	do {
258		_debug("attach %lx-%lx", first, last);
259
260		count = last - first + 1;
261		if (count > ARRAY_SIZE(pages))
262			count = ARRAY_SIZE(pages);
263		n = find_get_pages_contig(call->mapping, first, count, pages);
264		ASSERTCMP(n, ==, count);
265
266		loop = 0;
267		do {
268			msg->msg_flags = 0;
269			to = PAGE_SIZE;
270			if (first + loop >= last)
271				to = call->last_to;
272			else
273				msg->msg_flags = MSG_MORE;
274			iov->iov_base = kmap(pages[loop]) + offset;
275			iov->iov_len = to - offset;
276			offset = 0;
277
278			_debug("- range %u-%u%s",
279			       offset, to, msg->msg_flags ? " [more]" : "");
280			msg->msg_iov = (struct iovec *) iov;
281			msg->msg_iovlen = 1;
282
283			/* have to change the state *before* sending the last
284			 * packet as RxRPC might give us the reply before it
285			 * returns from sending the request */
286			if (first + loop >= last)
287				call->state = AFS_CALL_AWAIT_REPLY;
288			ret = rxrpc_kernel_send_data(call->rxcall, msg,
289						     to - offset);
290			kunmap(pages[loop]);
291			if (ret < 0)
292				break;
293		} while (++loop < count);
294		first += count;
295
296		for (loop = 0; loop < count; loop++)
297			put_page(pages[loop]);
298		if (ret < 0)
299			break;
300	} while (first <= last);
301
302	_leave(" = %d", ret);
303	return ret;
304}
305
306/*
307 * initiate a call
308 */
309int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
310		  const struct afs_wait_mode *wait_mode)
311{
312	struct sockaddr_rxrpc srx;
313	struct rxrpc_call *rxcall;
314	struct msghdr msg;
315	struct kvec iov[1];
316	int ret;
317	struct sk_buff *skb;
318
319	_enter("%x,{%d},", addr->s_addr, ntohs(call->port));
320
321	ASSERT(call->type != NULL);
322	ASSERT(call->type->name != NULL);
323
324	_debug("____MAKE %p{%s,%x} [%d]____",
325	       call, call->type->name, key_serial(call->key),
326	       atomic_read(&afs_outstanding_calls));
327
328	call->wait_mode = wait_mode;
329	INIT_WORK(&call->async_work, afs_process_async_call);
330
331	memset(&srx, 0, sizeof(srx));
332	srx.srx_family = AF_RXRPC;
333	srx.srx_service = call->service_id;
334	srx.transport_type = SOCK_DGRAM;
335	srx.transport_len = sizeof(srx.transport.sin);
336	srx.transport.sin.sin_family = AF_INET;
337	srx.transport.sin.sin_port = call->port;
338	memcpy(&srx.transport.sin.sin_addr, addr, 4);
339
340	/* create a call */
341	rxcall = rxrpc_kernel_begin_call(afs_socket, &srx, call->key,
342					 (unsigned long) call, gfp);
343	call->key = NULL;
344	if (IS_ERR(rxcall)) {
345		ret = PTR_ERR(rxcall);
346		goto error_kill_call;
347	}
348
349	call->rxcall = rxcall;
350
351	/* send the request */
352	iov[0].iov_base	= call->request;
353	iov[0].iov_len	= call->request_size;
354
355	msg.msg_name		= NULL;
356	msg.msg_namelen		= 0;
357	msg.msg_iov		= (struct iovec *) iov;
358	msg.msg_iovlen		= 1;
359	msg.msg_control		= NULL;
360	msg.msg_controllen	= 0;
361	msg.msg_flags		= (call->send_pages ? MSG_MORE : 0);
362
363	/* have to change the state *before* sending the last packet as RxRPC
364	 * might give us the reply before it returns from sending the
365	 * request */
366	if (!call->send_pages)
367		call->state = AFS_CALL_AWAIT_REPLY;
368	ret = rxrpc_kernel_send_data(rxcall, &msg, call->request_size);
369	if (ret < 0)
370		goto error_do_abort;
371
372	if (call->send_pages) {
373		ret = afs_send_pages(call, &msg, iov);
374		if (ret < 0)
375			goto error_do_abort;
376	}
377
378	/* at this point, an async call may no longer exist as it may have
379	 * already completed */
380	return wait_mode->wait(call);
381
382error_do_abort:
383	rxrpc_kernel_abort_call(rxcall, RX_USER_ABORT);
384	while ((skb = skb_dequeue(&call->rx_queue)))
385		afs_free_skb(skb);
386	rxrpc_kernel_end_call(rxcall);
387	call->rxcall = NULL;
388error_kill_call:
389	call->type->destructor(call);
390	afs_free_call(call);
391	_leave(" = %d", ret);
392	return ret;
393}
394
395/*
396 * handles intercepted messages that were arriving in the socket's Rx queue
397 * - called with the socket receive queue lock held to ensure message ordering
398 * - called with softirqs disabled
399 */
400static void afs_rx_interceptor(struct sock *sk, unsigned long user_call_ID,
401			       struct sk_buff *skb)
402{
403	struct afs_call *call = (struct afs_call *) user_call_ID;
404
405	_enter("%p,,%u", call, skb->mark);
406
407	_debug("ICPT %p{%u} [%d]",
408	       skb, skb->mark, atomic_read(&afs_outstanding_skbs));
409
410	ASSERTCMP(sk, ==, afs_socket->sk);
411	atomic_inc(&afs_outstanding_skbs);
412
413	if (!call) {
414		/* its an incoming call for our callback service */
415		skb_queue_tail(&afs_incoming_calls, skb);
416		queue_work(afs_wq, &afs_collect_incoming_call_work);
417	} else {
418		/* route the messages directly to the appropriate call */
419		skb_queue_tail(&call->rx_queue, skb);
420		call->wait_mode->rx_wakeup(call);
421	}
422
423	_leave("");
424}
425
426/*
427 * deliver messages to a call
428 */
429static void afs_deliver_to_call(struct afs_call *call)
430{
431	struct sk_buff *skb;
432	bool last;
433	u32 abort_code;
434	int ret;
435
436	_enter("");
437
438	while ((call->state == AFS_CALL_AWAIT_REPLY ||
439		call->state == AFS_CALL_AWAIT_OP_ID ||
440		call->state == AFS_CALL_AWAIT_REQUEST ||
441		call->state == AFS_CALL_AWAIT_ACK) &&
442	       (skb = skb_dequeue(&call->rx_queue))) {
443		switch (skb->mark) {
444		case RXRPC_SKB_MARK_DATA:
445			_debug("Rcv DATA");
446			last = rxrpc_kernel_is_data_last(skb);
447			ret = call->type->deliver(call, skb, last);
448			switch (ret) {
449			case 0:
450				if (last &&
451				    call->state == AFS_CALL_AWAIT_REPLY)
452					call->state = AFS_CALL_COMPLETE;
453				break;
454			case -ENOTCONN:
455				abort_code = RX_CALL_DEAD;
456				goto do_abort;
457			case -ENOTSUPP:
458				abort_code = RX_INVALID_OPERATION;
459				goto do_abort;
460			default:
461				abort_code = RXGEN_CC_UNMARSHAL;
462				if (call->state != AFS_CALL_AWAIT_REPLY)
463					abort_code = RXGEN_SS_UNMARSHAL;
464			do_abort:
465				rxrpc_kernel_abort_call(call->rxcall,
466							abort_code);
467				call->error = ret;
468				call->state = AFS_CALL_ERROR;
469				break;
470			}
471			afs_data_delivered(skb);
472			skb = NULL;
473			continue;
474		case RXRPC_SKB_MARK_FINAL_ACK:
475			_debug("Rcv ACK");
476			call->state = AFS_CALL_COMPLETE;
477			break;
478		case RXRPC_SKB_MARK_BUSY:
479			_debug("Rcv BUSY");
480			call->error = -EBUSY;
481			call->state = AFS_CALL_BUSY;
482			break;
483		case RXRPC_SKB_MARK_REMOTE_ABORT:
484			abort_code = rxrpc_kernel_get_abort_code(skb);
485			call->error = call->type->abort_to_error(abort_code);
486			call->state = AFS_CALL_ABORTED;
487			_debug("Rcv ABORT %u -> %d", abort_code, call->error);
488			break;
489		case RXRPC_SKB_MARK_NET_ERROR:
490			call->error = -rxrpc_kernel_get_error_number(skb);
491			call->state = AFS_CALL_ERROR;
492			_debug("Rcv NET ERROR %d", call->error);
493			break;
494		case RXRPC_SKB_MARK_LOCAL_ERROR:
495			call->error = -rxrpc_kernel_get_error_number(skb);
496			call->state = AFS_CALL_ERROR;
497			_debug("Rcv LOCAL ERROR %d", call->error);
498			break;
499		default:
500			BUG();
501			break;
502		}
503
504		afs_free_skb(skb);
505	}
506
507	/* make sure the queue is empty if the call is done with (we might have
508	 * aborted the call early because of an unmarshalling error) */
509	if (call->state >= AFS_CALL_COMPLETE) {
510		while ((skb = skb_dequeue(&call->rx_queue)))
511			afs_free_skb(skb);
512		if (call->incoming) {
513			rxrpc_kernel_end_call(call->rxcall);
514			call->rxcall = NULL;
515			call->type->destructor(call);
516			afs_free_call(call);
517		}
518	}
519
520	_leave("");
521}
522
523/*
524 * wait synchronously for a call to complete
525 */
526static int afs_wait_for_call_to_complete(struct afs_call *call)
527{
528	struct sk_buff *skb;
529	int ret;
530
531	DECLARE_WAITQUEUE(myself, current);
532
533	_enter("");
534
535	add_wait_queue(&call->waitq, &myself);
536	for (;;) {
537		set_current_state(TASK_INTERRUPTIBLE);
538
539		/* deliver any messages that are in the queue */
540		if (!skb_queue_empty(&call->rx_queue)) {
541			__set_current_state(TASK_RUNNING);
542			afs_deliver_to_call(call);
543			continue;
544		}
545
546		ret = call->error;
547		if (call->state >= AFS_CALL_COMPLETE)
548			break;
549		ret = -EINTR;
550		if (signal_pending(current))
551			break;
552		schedule();
553	}
554
555	remove_wait_queue(&call->waitq, &myself);
556	__set_current_state(TASK_RUNNING);
557
558	/* kill the call */
559	if (call->state < AFS_CALL_COMPLETE) {
560		_debug("call incomplete");
561		rxrpc_kernel_abort_call(call->rxcall, RX_CALL_DEAD);
562		while ((skb = skb_dequeue(&call->rx_queue)))
563			afs_free_skb(skb);
564	}
565
566	_debug("call complete");
567	rxrpc_kernel_end_call(call->rxcall);
568	call->rxcall = NULL;
569	call->type->destructor(call);
570	afs_free_call(call);
571	_leave(" = %d", ret);
572	return ret;
573}
574
575/*
576 * wake up a waiting call
577 */
578static void afs_wake_up_call_waiter(struct afs_call *call)
579{
580	wake_up(&call->waitq);
581}
582
583/*
584 * wake up an asynchronous call
585 */
586static void afs_wake_up_async_call(struct afs_call *call)
587{
588	_enter("");
589	queue_work(afs_async_calls, &call->async_work);
590}
591
592/*
593 * put a call into asynchronous mode
594 * - mustn't touch the call descriptor as the call my have completed by the
595 *   time we get here
596 */
597static int afs_dont_wait_for_call_to_complete(struct afs_call *call)
598{
599	_enter("");
600	return -EINPROGRESS;
601}
602
603/*
604 * delete an asynchronous call
605 */
606static void afs_delete_async_call(struct work_struct *work)
607{
608	struct afs_call *call =
609		container_of(work, struct afs_call, async_work);
610
611	_enter("");
612
613	afs_free_call(call);
614
615	_leave("");
616}
617
618/*
619 * perform processing on an asynchronous call
620 * - on a multiple-thread workqueue this work item may try to run on several
621 *   CPUs at the same time
622 */
623static void afs_process_async_call(struct work_struct *work)
624{
625	struct afs_call *call =
626		container_of(work, struct afs_call, async_work);
627
628	_enter("");
629
630	if (!skb_queue_empty(&call->rx_queue))
631		afs_deliver_to_call(call);
632
633	if (call->state >= AFS_CALL_COMPLETE && call->wait_mode) {
634		if (call->wait_mode->async_complete)
635			call->wait_mode->async_complete(call->reply,
636							call->error);
637		call->reply = NULL;
638
639		/* kill the call */
640		rxrpc_kernel_end_call(call->rxcall);
641		call->rxcall = NULL;
642		if (call->type->destructor)
643			call->type->destructor(call);
644
645		/* we can't just delete the call because the work item may be
646		 * queued */
647		PREPARE_WORK(&call->async_work, afs_delete_async_call);
648		queue_work(afs_async_calls, &call->async_work);
649	}
650
651	_leave("");
652}
653
654/*
655 * empty a socket buffer into a flat reply buffer
656 */
657void afs_transfer_reply(struct afs_call *call, struct sk_buff *skb)
658{
659	size_t len = skb->len;
660
661	if (skb_copy_bits(skb, 0, call->buffer + call->reply_size, len) < 0)
662		BUG();
663	call->reply_size += len;
664}
665
666/*
667 * accept the backlog of incoming calls
668 */
669static void afs_collect_incoming_call(struct work_struct *work)
670{
671	struct rxrpc_call *rxcall;
672	struct afs_call *call = NULL;
673	struct sk_buff *skb;
674
675	while ((skb = skb_dequeue(&afs_incoming_calls))) {
676		_debug("new call");
677
678		/* don't need the notification */
679		afs_free_skb(skb);
680
681		if (!call) {
682			call = kzalloc(sizeof(struct afs_call), GFP_KERNEL);
683			if (!call) {
684				rxrpc_kernel_reject_call(afs_socket);
685				return;
686			}
687
688			INIT_WORK(&call->async_work, afs_process_async_call);
689			call->wait_mode = &afs_async_incoming_call;
690			call->type = &afs_RXCMxxxx;
691			init_waitqueue_head(&call->waitq);
692			skb_queue_head_init(&call->rx_queue);
693			call->state = AFS_CALL_AWAIT_OP_ID;
694
695			_debug("CALL %p{%s} [%d]",
696			       call, call->type->name,
697			       atomic_read(&afs_outstanding_calls));
698			atomic_inc(&afs_outstanding_calls);
699		}
700
701		rxcall = rxrpc_kernel_accept_call(afs_socket,
702						  (unsigned long) call);
703		if (!IS_ERR(rxcall)) {
704			call->rxcall = rxcall;
705			call = NULL;
706		}
707	}
708
709	if (call)
710		afs_free_call(call);
711}
712
713/*
714 * grab the operation ID from an incoming cache manager call
715 */
716static int afs_deliver_cm_op_id(struct afs_call *call, struct sk_buff *skb,
717				bool last)
718{
719	size_t len = skb->len;
720	void *oibuf = (void *) &call->operation_ID;
721
722	_enter("{%u},{%zu},%d", call->offset, len, last);
723
724	ASSERTCMP(call->offset, <, 4);
725
726	/* the operation ID forms the first four bytes of the request data */
727	len = min_t(size_t, len, 4 - call->offset);
728	if (skb_copy_bits(skb, 0, oibuf + call->offset, len) < 0)
729		BUG();
730	if (!pskb_pull(skb, len))
731		BUG();
732	call->offset += len;
733
734	if (call->offset < 4) {
735		if (last) {
736			_leave(" = -EBADMSG [op ID short]");
737			return -EBADMSG;
738		}
739		_leave(" = 0 [incomplete]");
740		return 0;
741	}
742
743	call->state = AFS_CALL_AWAIT_REQUEST;
744
745	/* ask the cache manager to route the call (it'll change the call type
746	 * if successful) */
747	if (!afs_cm_incoming_call(call))
748		return -ENOTSUPP;
749
750	/* pass responsibility for the remainer of this message off to the
751	 * cache manager op */
752	return call->type->deliver(call, skb, last);
753}
754
755/*
756 * send an empty reply
757 */
758void afs_send_empty_reply(struct afs_call *call)
759{
760	struct msghdr msg;
761	struct iovec iov[1];
762
763	_enter("");
764
765	iov[0].iov_base		= NULL;
766	iov[0].iov_len		= 0;
767	msg.msg_name		= NULL;
768	msg.msg_namelen		= 0;
769	msg.msg_iov		= iov;
770	msg.msg_iovlen		= 0;
771	msg.msg_control		= NULL;
772	msg.msg_controllen	= 0;
773	msg.msg_flags		= 0;
774
775	call->state = AFS_CALL_AWAIT_ACK;
776	switch (rxrpc_kernel_send_data(call->rxcall, &msg, 0)) {
777	case 0:
778		_leave(" [replied]");
779		return;
780
781	case -ENOMEM:
782		_debug("oom");
783		rxrpc_kernel_abort_call(call->rxcall, RX_USER_ABORT);
784	default:
785		rxrpc_kernel_end_call(call->rxcall);
786		call->rxcall = NULL;
787		call->type->destructor(call);
788		afs_free_call(call);
789		_leave(" [error]");
790		return;
791	}
792}
793
794/*
795 * send a simple reply
796 */
797void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
798{
799	struct msghdr msg;
800	struct iovec iov[1];
801	int n;
802
803	_enter("");
804
805	iov[0].iov_base		= (void *) buf;
806	iov[0].iov_len		= len;
807	msg.msg_name		= NULL;
808	msg.msg_namelen		= 0;
809	msg.msg_iov		= iov;
810	msg.msg_iovlen		= 1;
811	msg.msg_control		= NULL;
812	msg.msg_controllen	= 0;
813	msg.msg_flags		= 0;
814
815	call->state = AFS_CALL_AWAIT_ACK;
816	n = rxrpc_kernel_send_data(call->rxcall, &msg, len);
817	if (n >= 0) {
818		_leave(" [replied]");
819		return;
820	}
821	if (n == -ENOMEM) {
822		_debug("oom");
823		rxrpc_kernel_abort_call(call->rxcall, RX_USER_ABORT);
824	}
825	rxrpc_kernel_end_call(call->rxcall);
826	call->rxcall = NULL;
827	call->type->destructor(call);
828	afs_free_call(call);
829	_leave(" [error]");
830}
831
832/*
833 * extract a piece of data from the received data socket buffers
834 */
835int afs_extract_data(struct afs_call *call, struct sk_buff *skb,
836		     bool last, void *buf, size_t count)
837{
838	size_t len = skb->len;
839
840	_enter("{%u},{%zu},%d,,%zu", call->offset, len, last, count);
841
842	ASSERTCMP(call->offset, <, count);
843
844	len = min_t(size_t, len, count - call->offset);
845	if (skb_copy_bits(skb, 0, buf + call->offset, len) < 0 ||
846	    !pskb_pull(skb, len))
847		BUG();
848	call->offset += len;
849
850	if (call->offset < count) {
851		if (last) {
852			_leave(" = -EBADMSG [%d < %zu]", call->offset, count);
853			return -EBADMSG;
854		}
855		_leave(" = -EAGAIN");
856		return -EAGAIN;
857	}
858	return 0;
859}