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Linux 4.6-rc6
[cris-mirror.git] / fs / afs / rxrpc.c
blobb50642870a43b9675a3b1fe97b1cfadcdbb1c54a
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
19 static struct socket *afs_socket; /* my RxRPC socket */
20 static struct workqueue_struct *afs_async_calls;
21 static atomic_t afs_outstanding_calls;
22 static atomic_t afs_outstanding_skbs;
23
24 static void afs_wake_up_call_waiter(struct afs_call *);
25 static int afs_wait_for_call_to_complete(struct afs_call *);
26 static void afs_wake_up_async_call(struct afs_call *);
27 static int afs_dont_wait_for_call_to_complete(struct afs_call *);
28 static void afs_process_async_call(struct afs_call *);
29 static void afs_rx_interceptor(struct sock *, unsigned long, struct sk_buff *);
30 static int afs_deliver_cm_op_id(struct afs_call *, struct sk_buff *, bool);
31
32 /* synchronous call management */
33 const 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 */
39 const 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 */
45 static 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 */
50 static 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
56 static void afs_collect_incoming_call(struct work_struct *);
57
58 static struct sk_buff_head afs_incoming_calls;
59 static DECLARE_WORK(afs_collect_incoming_call_work, afs_collect_incoming_call);
60
61 static void afs_async_workfn(struct work_struct *work)
62 {
63 struct afs_call *call = container_of(work, struct afs_call, async_work);
64
65 call->async_workfn(call);
66 }
67
68 /*
69 * open an RxRPC socket and bind it to be a server for callback notifications
70 * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
71 */
72 int afs_open_socket(void)
73 {
74 struct sockaddr_rxrpc srx;
75 struct socket *socket;
76 int ret;
77
78 _enter("");
79
80 skb_queue_head_init(&afs_incoming_calls);
81
82 afs_async_calls = create_singlethread_workqueue("kafsd");
83 if (!afs_async_calls) {
84 _leave(" = -ENOMEM [wq]");
85 return -ENOMEM;
86 }
87
88 ret = sock_create_kern(&init_net, AF_RXRPC, SOCK_DGRAM, PF_INET, &socket);
89 if (ret < 0) {
90 destroy_workqueue(afs_async_calls);
91 _leave(" = %d [socket]", ret);
92 return ret;
93 }
94
95 socket->sk->sk_allocation = GFP_NOFS;
96
97 /* bind the callback manager's address to make this a server socket */
98 srx.srx_family = AF_RXRPC;
99 srx.srx_service = CM_SERVICE;
100 srx.transport_type = SOCK_DGRAM;
101 srx.transport_len = sizeof(srx.transport.sin);
102 srx.transport.sin.sin_family = AF_INET;
103 srx.transport.sin.sin_port = htons(AFS_CM_PORT);
104 memset(&srx.transport.sin.sin_addr, 0,
105 sizeof(srx.transport.sin.sin_addr));
106
107 ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
108 if (ret < 0) {
109 sock_release(socket);
110 destroy_workqueue(afs_async_calls);
111 _leave(" = %d [bind]", ret);
112 return ret;
113 }
114
115 rxrpc_kernel_intercept_rx_messages(socket, afs_rx_interceptor);
116
117 afs_socket = socket;
118 _leave(" = 0");
119 return 0;
120 }
121
122 /*
123 * close the RxRPC socket AFS was using
124 */
125 void afs_close_socket(void)
126 {
127 _enter("");
128
129 sock_release(afs_socket);
130
131 _debug("dework");
132 destroy_workqueue(afs_async_calls);
133
134 ASSERTCMP(atomic_read(&afs_outstanding_skbs), ==, 0);
135 ASSERTCMP(atomic_read(&afs_outstanding_calls), ==, 0);
136 _leave("");
137 }
138
139 /*
140 * note that the data in a socket buffer is now delivered and that the buffer
141 * should be freed
142 */
143 static void afs_data_delivered(struct sk_buff *skb)
144 {
145 if (!skb) {
146 _debug("DLVR NULL [%d]", atomic_read(&afs_outstanding_skbs));
147 dump_stack();
148 } else {
149 _debug("DLVR %p{%u} [%d]",
150 skb, skb->mark, atomic_read(&afs_outstanding_skbs));
151 if (atomic_dec_return(&afs_outstanding_skbs) == -1)
152 BUG();
153 rxrpc_kernel_data_delivered(skb);
154 }
155 }
156
157 /*
158 * free a socket buffer
159 */
160 static void afs_free_skb(struct sk_buff *skb)
161 {
162 if (!skb) {
163 _debug("FREE NULL [%d]", atomic_read(&afs_outstanding_skbs));
164 dump_stack();
165 } else {
166 _debug("FREE %p{%u} [%d]",
167 skb, skb->mark, atomic_read(&afs_outstanding_skbs));
168 if (atomic_dec_return(&afs_outstanding_skbs) == -1)
169 BUG();
170 rxrpc_kernel_free_skb(skb);
171 }
172 }
173
174 /*
175 * free a call
176 */
177 static void afs_free_call(struct afs_call *call)
178 {
179 _debug("DONE %p{%s} [%d]",
180 call, call->type->name, atomic_read(&afs_outstanding_calls));
181 if (atomic_dec_return(&afs_outstanding_calls) == -1)
182 BUG();
183
184 ASSERTCMP(call->rxcall, ==, NULL);
185 ASSERT(!work_pending(&call->async_work));
186 ASSERT(skb_queue_empty(&call->rx_queue));
187 ASSERT(call->type->name != NULL);
188
189 kfree(call->request);
190 kfree(call);
191 }
192
193 /*
194 * End a call but do not free it
195 */
196 static void afs_end_call_nofree(struct afs_call *call)
197 {
198 if (call->rxcall) {
199 rxrpc_kernel_end_call(call->rxcall);
200 call->rxcall = NULL;
201 }
202 if (call->type->destructor)
203 call->type->destructor(call);
204 }
205
206 /*
207 * End a call and free it
208 */
209 static void afs_end_call(struct afs_call *call)
210 {
211 afs_end_call_nofree(call);
212 afs_free_call(call);
213 }
214
215 /*
216 * allocate a call with flat request and reply buffers
217 */
218 struct afs_call *afs_alloc_flat_call(const struct afs_call_type *type,
219 size_t request_size, size_t reply_size)
220 {
221 struct afs_call *call;
222
223 call = kzalloc(sizeof(*call), GFP_NOFS);
224 if (!call)
225 goto nomem_call;
226
227 _debug("CALL %p{%s} [%d]",
228 call, type->name, atomic_read(&afs_outstanding_calls));
229 atomic_inc(&afs_outstanding_calls);
230
231 call->type = type;
232 call->request_size = request_size;
233 call->reply_max = reply_size;
234
235 if (request_size) {
236 call->request = kmalloc(request_size, GFP_NOFS);
237 if (!call->request)
238 goto nomem_free;
239 }
240
241 if (reply_size) {
242 call->buffer = kmalloc(reply_size, GFP_NOFS);
243 if (!call->buffer)
244 goto nomem_free;
245 }
246
247 init_waitqueue_head(&call->waitq);
248 skb_queue_head_init(&call->rx_queue);
249 return call;
250
251 nomem_free:
252 afs_free_call(call);
253 nomem_call:
254 return NULL;
255 }
256
257 /*
258 * clean up a call with flat buffer
259 */
260 void afs_flat_call_destructor(struct afs_call *call)
261 {
262 _enter("");
263
264 kfree(call->request);
265 call->request = NULL;
266 kfree(call->buffer);
267 call->buffer = NULL;
268 }
269
270 /*
271 * attach the data from a bunch of pages on an inode to a call
272 */
273 static int afs_send_pages(struct afs_call *call, struct msghdr *msg,
274 struct kvec *iov)
275 {
276 struct page *pages[8];
277 unsigned count, n, loop, offset, to;
278 pgoff_t first = call->first, last = call->last;
279 int ret;
280
281 _enter("");
282
283 offset = call->first_offset;
284 call->first_offset = 0;
285
286 do {
287 _debug("attach %lx-%lx", first, last);
288
289 count = last - first + 1;
290 if (count > ARRAY_SIZE(pages))
291 count = ARRAY_SIZE(pages);
292 n = find_get_pages_contig(call->mapping, first, count, pages);
293 ASSERTCMP(n, ==, count);
294
295 loop = 0;
296 do {
297 msg->msg_flags = 0;
298 to = PAGE_SIZE;
299 if (first + loop >= last)
300 to = call->last_to;
301 else
302 msg->msg_flags = MSG_MORE;
303 iov->iov_base = kmap(pages[loop]) + offset;
304 iov->iov_len = to - offset;
305 offset = 0;
306
307 _debug("- range %u-%u%s",
308 offset, to, msg->msg_flags ? " [more]" : "");
309 iov_iter_kvec(&msg->msg_iter, WRITE | ITER_KVEC,
310 iov, 1, to - offset);
311
312 /* have to change the state *before* sending the last
313 * packet as RxRPC might give us the reply before it
314 * returns from sending the request */
315 if (first + loop >= last)
316 call->state = AFS_CALL_AWAIT_REPLY;
317 ret = rxrpc_kernel_send_data(call->rxcall, msg,
318 to - offset);
319 kunmap(pages[loop]);
320 if (ret < 0)
321 break;
322 } while (++loop < count);
323 first += count;
324
325 for (loop = 0; loop < count; loop++)
326 put_page(pages[loop]);
327 if (ret < 0)
328 break;
329 } while (first <= last);
330
331 _leave(" = %d", ret);
332 return ret;
333 }
334
335 /*
336 * initiate a call
337 */
338 int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
339 const struct afs_wait_mode *wait_mode)
340 {
341 struct sockaddr_rxrpc srx;
342 struct rxrpc_call *rxcall;
343 struct msghdr msg;
344 struct kvec iov[1];
345 int ret;
346 struct sk_buff *skb;
347
348 _enter("%x,{%d},", addr->s_addr, ntohs(call->port));
349
350 ASSERT(call->type != NULL);
351 ASSERT(call->type->name != NULL);
352
353 _debug("____MAKE %p{%s,%x} [%d]____",
354 call, call->type->name, key_serial(call->key),
355 atomic_read(&afs_outstanding_calls));
356
357 call->wait_mode = wait_mode;
358 call->async_workfn = afs_process_async_call;
359 INIT_WORK(&call->async_work, afs_async_workfn);
360
361 memset(&srx, 0, sizeof(srx));
362 srx.srx_family = AF_RXRPC;
363 srx.srx_service = call->service_id;
364 srx.transport_type = SOCK_DGRAM;
365 srx.transport_len = sizeof(srx.transport.sin);
366 srx.transport.sin.sin_family = AF_INET;
367 srx.transport.sin.sin_port = call->port;
368 memcpy(&srx.transport.sin.sin_addr, addr, 4);
369
370 /* create a call */
371 rxcall = rxrpc_kernel_begin_call(afs_socket, &srx, call->key,
372 (unsigned long) call, gfp);
373 call->key = NULL;
374 if (IS_ERR(rxcall)) {
375 ret = PTR_ERR(rxcall);
376 goto error_kill_call;
377 }
378
379 call->rxcall = rxcall;
380
381 /* send the request */
382 iov[0].iov_base = call->request;
383 iov[0].iov_len = call->request_size;
384
385 msg.msg_name = NULL;
386 msg.msg_namelen = 0;
387 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1,
388 call->request_size);
389 msg.msg_control = NULL;
390 msg.msg_controllen = 0;
391 msg.msg_flags = (call->send_pages ? MSG_MORE : 0);
392
393 /* have to change the state *before* sending the last packet as RxRPC
394 * might give us the reply before it returns from sending the
395 * request */
396 if (!call->send_pages)
397 call->state = AFS_CALL_AWAIT_REPLY;
398 ret = rxrpc_kernel_send_data(rxcall, &msg, call->request_size);
399 if (ret < 0)
400 goto error_do_abort;
401
402 if (call->send_pages) {
403 ret = afs_send_pages(call, &msg, iov);
404 if (ret < 0)
405 goto error_do_abort;
406 }
407
408 /* at this point, an async call may no longer exist as it may have
409 * already completed */
410 return wait_mode->wait(call);
411
412 error_do_abort:
413 rxrpc_kernel_abort_call(rxcall, RX_USER_ABORT);
414 while ((skb = skb_dequeue(&call->rx_queue)))
415 afs_free_skb(skb);
416 error_kill_call:
417 afs_end_call(call);
418 _leave(" = %d", ret);
419 return ret;
420 }
421
422 /*
423 * handles intercepted messages that were arriving in the socket's Rx queue
424 * - called with the socket receive queue lock held to ensure message ordering
425 * - called with softirqs disabled
426 */
427 static void afs_rx_interceptor(struct sock *sk, unsigned long user_call_ID,
428 struct sk_buff *skb)
429 {
430 struct afs_call *call = (struct afs_call *) user_call_ID;
431
432 _enter("%p,,%u", call, skb->mark);
433
434 _debug("ICPT %p{%u} [%d]",
435 skb, skb->mark, atomic_read(&afs_outstanding_skbs));
436
437 ASSERTCMP(sk, ==, afs_socket->sk);
438 atomic_inc(&afs_outstanding_skbs);
439
440 if (!call) {
441 /* its an incoming call for our callback service */
442 skb_queue_tail(&afs_incoming_calls, skb);
443 queue_work(afs_wq, &afs_collect_incoming_call_work);
444 } else {
445 /* route the messages directly to the appropriate call */
446 skb_queue_tail(&call->rx_queue, skb);
447 call->wait_mode->rx_wakeup(call);
448 }
449
450 _leave("");
451 }
452
453 /*
454 * deliver messages to a call
455 */
456 static void afs_deliver_to_call(struct afs_call *call)
457 {
458 struct sk_buff *skb;
459 bool last;
460 u32 abort_code;
461 int ret;
462
463 _enter("");
464
465 while ((call->state == AFS_CALL_AWAIT_REPLY ||
466 call->state == AFS_CALL_AWAIT_OP_ID ||
467 call->state == AFS_CALL_AWAIT_REQUEST ||
468 call->state == AFS_CALL_AWAIT_ACK) &&
469 (skb = skb_dequeue(&call->rx_queue))) {
470 switch (skb->mark) {
471 case RXRPC_SKB_MARK_DATA:
472 _debug("Rcv DATA");
473 last = rxrpc_kernel_is_data_last(skb);
474 ret = call->type->deliver(call, skb, last);
475 switch (ret) {
476 case 0:
477 if (last &&
478 call->state == AFS_CALL_AWAIT_REPLY)
479 call->state = AFS_CALL_COMPLETE;
480 break;
481 case -ENOTCONN:
482 abort_code = RX_CALL_DEAD;
483 goto do_abort;
484 case -ENOTSUPP:
485 abort_code = RX_INVALID_OPERATION;
486 goto do_abort;
487 default:
488 abort_code = RXGEN_CC_UNMARSHAL;
489 if (call->state != AFS_CALL_AWAIT_REPLY)
490 abort_code = RXGEN_SS_UNMARSHAL;
491 do_abort:
492 rxrpc_kernel_abort_call(call->rxcall,
493 abort_code);
494 call->error = ret;
495 call->state = AFS_CALL_ERROR;
496 break;
497 }
498 afs_data_delivered(skb);
499 skb = NULL;
500 continue;
501 case RXRPC_SKB_MARK_FINAL_ACK:
502 _debug("Rcv ACK");
503 call->state = AFS_CALL_COMPLETE;
504 break;
505 case RXRPC_SKB_MARK_BUSY:
506 _debug("Rcv BUSY");
507 call->error = -EBUSY;
508 call->state = AFS_CALL_BUSY;
509 break;
510 case RXRPC_SKB_MARK_REMOTE_ABORT:
511 abort_code = rxrpc_kernel_get_abort_code(skb);
512 call->error = call->type->abort_to_error(abort_code);
513 call->state = AFS_CALL_ABORTED;
514 _debug("Rcv ABORT %u -> %d", abort_code, call->error);
515 break;
516 case RXRPC_SKB_MARK_NET_ERROR:
517 call->error = -rxrpc_kernel_get_error_number(skb);
518 call->state = AFS_CALL_ERROR;
519 _debug("Rcv NET ERROR %d", call->error);
520 break;
521 case RXRPC_SKB_MARK_LOCAL_ERROR:
522 call->error = -rxrpc_kernel_get_error_number(skb);
523 call->state = AFS_CALL_ERROR;
524 _debug("Rcv LOCAL ERROR %d", call->error);
525 break;
526 default:
527 BUG();
528 break;
529 }
530
531 afs_free_skb(skb);
532 }
533
534 /* make sure the queue is empty if the call is done with (we might have
535 * aborted the call early because of an unmarshalling error) */
536 if (call->state >= AFS_CALL_COMPLETE) {
537 while ((skb = skb_dequeue(&call->rx_queue)))
538 afs_free_skb(skb);
539 if (call->incoming)
540 afs_end_call(call);
541 }
542
543 _leave("");
544 }
545
546 /*
547 * wait synchronously for a call to complete
548 */
549 static int afs_wait_for_call_to_complete(struct afs_call *call)
550 {
551 struct sk_buff *skb;
552 int ret;
553
554 DECLARE_WAITQUEUE(myself, current);
555
556 _enter("");
557
558 add_wait_queue(&call->waitq, &myself);
559 for (;;) {
560 set_current_state(TASK_INTERRUPTIBLE);
561
562 /* deliver any messages that are in the queue */
563 if (!skb_queue_empty(&call->rx_queue)) {
564 __set_current_state(TASK_RUNNING);
565 afs_deliver_to_call(call);
566 continue;
567 }
568
569 ret = call->error;
570 if (call->state >= AFS_CALL_COMPLETE)
571 break;
572 ret = -EINTR;
573 if (signal_pending(current))
574 break;
575 schedule();
576 }
577
578 remove_wait_queue(&call->waitq, &myself);
579 __set_current_state(TASK_RUNNING);
580
581 /* kill the call */
582 if (call->state < AFS_CALL_COMPLETE) {
583 _debug("call incomplete");
584 rxrpc_kernel_abort_call(call->rxcall, RX_CALL_DEAD);
585 while ((skb = skb_dequeue(&call->rx_queue)))
586 afs_free_skb(skb);
587 }
588
589 _debug("call complete");
590 afs_end_call(call);
591 _leave(" = %d", ret);
592 return ret;
593 }
594
595 /*
596 * wake up a waiting call
597 */
598 static void afs_wake_up_call_waiter(struct afs_call *call)
599 {
600 wake_up(&call->waitq);
601 }
602
603 /*
604 * wake up an asynchronous call
605 */
606 static void afs_wake_up_async_call(struct afs_call *call)
607 {
608 _enter("");
609 queue_work(afs_async_calls, &call->async_work);
610 }
611
612 /*
613 * put a call into asynchronous mode
614 * - mustn't touch the call descriptor as the call my have completed by the
615 * time we get here
616 */
617 static int afs_dont_wait_for_call_to_complete(struct afs_call *call)
618 {
619 _enter("");
620 return -EINPROGRESS;
621 }
622
623 /*
624 * delete an asynchronous call
625 */
626 static void afs_delete_async_call(struct afs_call *call)
627 {
628 _enter("");
629
630 afs_free_call(call);
631
632 _leave("");
633 }
634
635 /*
636 * perform processing on an asynchronous call
637 * - on a multiple-thread workqueue this work item may try to run on several
638 * CPUs at the same time
639 */
640 static void afs_process_async_call(struct afs_call *call)
641 {
642 _enter("");
643
644 if (!skb_queue_empty(&call->rx_queue))
645 afs_deliver_to_call(call);
646
647 if (call->state >= AFS_CALL_COMPLETE && call->wait_mode) {
648 if (call->wait_mode->async_complete)
649 call->wait_mode->async_complete(call->reply,
650 call->error);
651 call->reply = NULL;
652
653 /* kill the call */
654 afs_end_call_nofree(call);
655
656 /* we can't just delete the call because the work item may be
657 * queued */
658 call->async_workfn = afs_delete_async_call;
659 queue_work(afs_async_calls, &call->async_work);
660 }
661
662 _leave("");
663 }
664
665 /*
666 * empty a socket buffer into a flat reply buffer
667 */
668 void afs_transfer_reply(struct afs_call *call, struct sk_buff *skb)
669 {
670 size_t len = skb->len;
671
672 if (skb_copy_bits(skb, 0, call->buffer + call->reply_size, len) < 0)
673 BUG();
674 call->reply_size += len;
675 }
676
677 /*
678 * accept the backlog of incoming calls
679 */
680 static void afs_collect_incoming_call(struct work_struct *work)
681 {
682 struct rxrpc_call *rxcall;
683 struct afs_call *call = NULL;
684 struct sk_buff *skb;
685
686 while ((skb = skb_dequeue(&afs_incoming_calls))) {
687 _debug("new call");
688
689 /* don't need the notification */
690 afs_free_skb(skb);
691
692 if (!call) {
693 call = kzalloc(sizeof(struct afs_call), GFP_KERNEL);
694 if (!call) {
695 rxrpc_kernel_reject_call(afs_socket);
696 return;
697 }
698
699 call->async_workfn = afs_process_async_call;
700 INIT_WORK(&call->async_work, afs_async_workfn);
701 call->wait_mode = &afs_async_incoming_call;
702 call->type = &afs_RXCMxxxx;
703 init_waitqueue_head(&call->waitq);
704 skb_queue_head_init(&call->rx_queue);
705 call->state = AFS_CALL_AWAIT_OP_ID;
706
707 _debug("CALL %p{%s} [%d]",
708 call, call->type->name,
709 atomic_read(&afs_outstanding_calls));
710 atomic_inc(&afs_outstanding_calls);
711 }
712
713 rxcall = rxrpc_kernel_accept_call(afs_socket,
714 (unsigned long) call);
715 if (!IS_ERR(rxcall)) {
716 call->rxcall = rxcall;
717 call = NULL;
718 }
719 }
720
721 if (call)
722 afs_free_call(call);
723 }
724
725 /*
726 * grab the operation ID from an incoming cache manager call
727 */
728 static int afs_deliver_cm_op_id(struct afs_call *call, struct sk_buff *skb,
729 bool last)
730 {
731 size_t len = skb->len;
732 void *oibuf = (void *) &call->operation_ID;
733
734 _enter("{%u},{%zu},%d", call->offset, len, last);
735
736 ASSERTCMP(call->offset, <, 4);
737
738 /* the operation ID forms the first four bytes of the request data */
739 len = min_t(size_t, len, 4 - call->offset);
740 if (skb_copy_bits(skb, 0, oibuf + call->offset, len) < 0)
741 BUG();
742 if (!pskb_pull(skb, len))
743 BUG();
744 call->offset += len;
745
746 if (call->offset < 4) {
747 if (last) {
748 _leave(" = -EBADMSG [op ID short]");
749 return -EBADMSG;
750 }
751 _leave(" = 0 [incomplete]");
752 return 0;
753 }
754
755 call->state = AFS_CALL_AWAIT_REQUEST;
756
757 /* ask the cache manager to route the call (it'll change the call type
758 * if successful) */
759 if (!afs_cm_incoming_call(call))
760 return -ENOTSUPP;
761
762 /* pass responsibility for the remainer of this message off to the
763 * cache manager op */
764 return call->type->deliver(call, skb, last);
765 }
766
767 /*
768 * send an empty reply
769 */
770 void afs_send_empty_reply(struct afs_call *call)
771 {
772 struct msghdr msg;
773
774 _enter("");
775
776 msg.msg_name = NULL;
777 msg.msg_namelen = 0;
778 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, NULL, 0, 0);
779 msg.msg_control = NULL;
780 msg.msg_controllen = 0;
781 msg.msg_flags = 0;
782
783 call->state = AFS_CALL_AWAIT_ACK;
784 switch (rxrpc_kernel_send_data(call->rxcall, &msg, 0)) {
785 case 0:
786 _leave(" [replied]");
787 return;
788
789 case -ENOMEM:
790 _debug("oom");
791 rxrpc_kernel_abort_call(call->rxcall, RX_USER_ABORT);
792 default:
793 afs_end_call(call);
794 _leave(" [error]");
795 return;
796 }
797 }
798
799 /*
800 * send a simple reply
801 */
802 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
803 {
804 struct msghdr msg;
805 struct kvec iov[1];
806 int n;
807
808 _enter("");
809
810 iov[0].iov_base = (void *) buf;
811 iov[0].iov_len = len;
812 msg.msg_name = NULL;
813 msg.msg_namelen = 0;
814 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1, len);
815 msg.msg_control = NULL;
816 msg.msg_controllen = 0;
817 msg.msg_flags = 0;
818
819 call->state = AFS_CALL_AWAIT_ACK;
820 n = rxrpc_kernel_send_data(call->rxcall, &msg, len);
821 if (n >= 0) {
822 /* Success */
823 _leave(" [replied]");
824 return;
825 }
826
827 if (n == -ENOMEM) {
828 _debug("oom");
829 rxrpc_kernel_abort_call(call->rxcall, RX_USER_ABORT);
830 }
831 afs_end_call(call);
832 _leave(" [error]");
833 }
834
835 /*
836 * extract a piece of data from the received data socket buffers
837 */
838 int afs_extract_data(struct afs_call *call, struct sk_buff *skb,
839 bool last, void *buf, size_t count)
840 {
841 size_t len = skb->len;
842
843 _enter("{%u},{%zu},%d,,%zu", call->offset, len, last, count);
844
845 ASSERTCMP(call->offset, <, count);
846
847 len = min_t(size_t, len, count - call->offset);
848 if (skb_copy_bits(skb, 0, buf + call->offset, len) < 0 ||
849 !pskb_pull(skb, len))
850 BUG();
851 call->offset += len;
852
853 if (call->offset < count) {
854 if (last) {
855 _leave(" = -EBADMSG [%d < %zu]", call->offset, count);
856 return -EBADMSG;
857 }
858 _leave(" = -EAGAIN");
859 return -EAGAIN;
860 }
861 return 0;
862 }
CRIS linux kernel tree