1 /* Maintain an RxRPC server socket to do AFS communications through
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
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.
12 #include <linux/slab.h>
14 #include <net/af_rxrpc.h>
15 #include <rxrpc/packet.h>
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;
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 work_struct *);
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);
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,
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,
44 /* asynchronous incoming call management */
45 static const struct afs_wait_mode afs_async_incoming_call = {
46 .rx_wakeup = afs_wake_up_async_call,
49 /* asynchronous incoming call initial processing */
50 static const struct afs_call_type afs_RXCMxxxx = {
52 .deliver = afs_deliver_cm_op_id,
53 .abort_to_error = afs_abort_to_error,
56 static void afs_collect_incoming_call(struct work_struct *);
58 static struct sk_buff_head afs_incoming_calls;
59 static DECLARE_WORK(afs_collect_incoming_call_work, afs_collect_incoming_call);
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
65 int afs_open_socket(void)
67 struct sockaddr_rxrpc srx;
68 struct socket *socket;
73 skb_queue_head_init(&afs_incoming_calls);
75 afs_async_calls = create_singlethread_workqueue("kafsd");
76 if (!afs_async_calls) {
77 _leave(" = -ENOMEM [wq]");
81 ret = sock_create_kern(AF_RXRPC, SOCK_DGRAM, PF_INET, &socket);
83 destroy_workqueue(afs_async_calls);
84 _leave(" = %d [socket]", ret);
88 socket->sk->sk_allocation = GFP_NOFS;
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));
100 ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
102 sock_release(socket);
103 destroy_workqueue(afs_async_calls);
104 _leave(" = %d [bind]", ret);
108 rxrpc_kernel_intercept_rx_messages(socket, afs_rx_interceptor);
116 * close the RxRPC socket AFS was using
118 void afs_close_socket(void)
122 sock_release(afs_socket);
125 destroy_workqueue(afs_async_calls);
127 ASSERTCMP(atomic_read(&afs_outstanding_skbs), ==, 0);
128 ASSERTCMP(atomic_read(&afs_outstanding_calls), ==, 0);
133 * note that the data in a socket buffer is now delivered and that the buffer
136 static void afs_data_delivered(struct sk_buff *skb)
139 _debug("DLVR NULL [%d]", atomic_read(&afs_outstanding_skbs));
142 _debug("DLVR %p{%u} [%d]",
143 skb, skb->mark, atomic_read(&afs_outstanding_skbs));
144 if (atomic_dec_return(&afs_outstanding_skbs) == -1)
146 rxrpc_kernel_data_delivered(skb);
151 * free a socket buffer
153 static void afs_free_skb(struct sk_buff *skb)
156 _debug("FREE NULL [%d]", atomic_read(&afs_outstanding_skbs));
159 _debug("FREE %p{%u} [%d]",
160 skb, skb->mark, atomic_read(&afs_outstanding_skbs));
161 if (atomic_dec_return(&afs_outstanding_skbs) == -1)
163 rxrpc_kernel_free_skb(skb);
170 static void afs_free_call(struct afs_call *call)
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)
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);
182 kfree(call->request);
189 static void afs_end_call(struct afs_call *call)
192 rxrpc_kernel_end_call(call->rxcall);
195 call->type->destructor(call);
200 * allocate a call with flat request and reply buffers
202 struct afs_call *afs_alloc_flat_call(const struct afs_call_type *type,
203 size_t request_size, size_t reply_size)
205 struct afs_call *call;
207 call = kzalloc(sizeof(*call), GFP_NOFS);
211 _debug("CALL %p{%s} [%d]",
212 call, type->name, atomic_read(&afs_outstanding_calls));
213 atomic_inc(&afs_outstanding_calls);
216 call->request_size = request_size;
217 call->reply_max = reply_size;
220 call->request = kmalloc(request_size, GFP_NOFS);
226 call->buffer = kmalloc(reply_size, GFP_NOFS);
231 init_waitqueue_head(&call->waitq);
232 skb_queue_head_init(&call->rx_queue);
242 * clean up a call with flat buffer
244 void afs_flat_call_destructor(struct afs_call *call)
248 kfree(call->request);
249 call->request = NULL;
255 * attach the data from a bunch of pages on an inode to a call
257 static int afs_send_pages(struct afs_call *call, struct msghdr *msg,
260 struct page *pages[8];
261 unsigned count, n, loop, offset, to;
262 pgoff_t first = call->first, last = call->last;
267 offset = call->first_offset;
268 call->first_offset = 0;
271 _debug("attach %lx-%lx", first, last);
273 count = last - first + 1;
274 if (count > ARRAY_SIZE(pages))
275 count = ARRAY_SIZE(pages);
276 n = find_get_pages_contig(call->mapping, first, count, pages);
277 ASSERTCMP(n, ==, count);
283 if (first + loop >= last)
286 msg->msg_flags = MSG_MORE;
287 iov->iov_base = kmap(pages[loop]) + offset;
288 iov->iov_len = to - offset;
291 _debug("- range %u-%u%s",
292 offset, to, msg->msg_flags ? " [more]" : "");
293 msg->msg_iov = (struct iovec *) iov;
296 /* have to change the state *before* sending the last
297 * packet as RxRPC might give us the reply before it
298 * returns from sending the request */
299 if (first + loop >= last)
300 call->state = AFS_CALL_AWAIT_REPLY;
301 ret = rxrpc_kernel_send_data(call->rxcall, msg,
306 } while (++loop < count);
309 for (loop = 0; loop < count; loop++)
310 put_page(pages[loop]);
313 } while (first <= last);
315 _leave(" = %d", ret);
322 int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
323 const struct afs_wait_mode *wait_mode)
325 struct sockaddr_rxrpc srx;
326 struct rxrpc_call *rxcall;
332 _enter("%x,{%d},", addr->s_addr, ntohs(call->port));
334 ASSERT(call->type != NULL);
335 ASSERT(call->type->name != NULL);
337 _debug("____MAKE %p{%s,%x} [%d]____",
338 call, call->type->name, key_serial(call->key),
339 atomic_read(&afs_outstanding_calls));
341 call->wait_mode = wait_mode;
342 INIT_WORK(&call->async_work, afs_process_async_call);
344 memset(&srx, 0, sizeof(srx));
345 srx.srx_family = AF_RXRPC;
346 srx.srx_service = call->service_id;
347 srx.transport_type = SOCK_DGRAM;
348 srx.transport_len = sizeof(srx.transport.sin);
349 srx.transport.sin.sin_family = AF_INET;
350 srx.transport.sin.sin_port = call->port;
351 memcpy(&srx.transport.sin.sin_addr, addr, 4);
354 rxcall = rxrpc_kernel_begin_call(afs_socket, &srx, call->key,
355 (unsigned long) call, gfp);
357 if (IS_ERR(rxcall)) {
358 ret = PTR_ERR(rxcall);
359 goto error_kill_call;
362 call->rxcall = rxcall;
364 /* send the request */
365 iov[0].iov_base = call->request;
366 iov[0].iov_len = call->request_size;
370 msg.msg_iov = (struct iovec *) iov;
372 msg.msg_control = NULL;
373 msg.msg_controllen = 0;
374 msg.msg_flags = (call->send_pages ? MSG_MORE : 0);
376 /* have to change the state *before* sending the last packet as RxRPC
377 * might give us the reply before it returns from sending the
379 if (!call->send_pages)
380 call->state = AFS_CALL_AWAIT_REPLY;
381 ret = rxrpc_kernel_send_data(rxcall, &msg, call->request_size);
385 if (call->send_pages) {
386 ret = afs_send_pages(call, &msg, iov);
391 /* at this point, an async call may no longer exist as it may have
392 * already completed */
393 return wait_mode->wait(call);
396 rxrpc_kernel_abort_call(rxcall, RX_USER_ABORT);
397 while ((skb = skb_dequeue(&call->rx_queue)))
401 _leave(" = %d", ret);
406 * handles intercepted messages that were arriving in the socket's Rx queue
407 * - called with the socket receive queue lock held to ensure message ordering
408 * - called with softirqs disabled
410 static void afs_rx_interceptor(struct sock *sk, unsigned long user_call_ID,
413 struct afs_call *call = (struct afs_call *) user_call_ID;
415 _enter("%p,,%u", call, skb->mark);
417 _debug("ICPT %p{%u} [%d]",
418 skb, skb->mark, atomic_read(&afs_outstanding_skbs));
420 ASSERTCMP(sk, ==, afs_socket->sk);
421 atomic_inc(&afs_outstanding_skbs);
424 /* its an incoming call for our callback service */
425 skb_queue_tail(&afs_incoming_calls, skb);
426 queue_work(afs_wq, &afs_collect_incoming_call_work);
428 /* route the messages directly to the appropriate call */
429 skb_queue_tail(&call->rx_queue, skb);
430 call->wait_mode->rx_wakeup(call);
437 * deliver messages to a call
439 static void afs_deliver_to_call(struct afs_call *call)
448 while ((call->state == AFS_CALL_AWAIT_REPLY ||
449 call->state == AFS_CALL_AWAIT_OP_ID ||
450 call->state == AFS_CALL_AWAIT_REQUEST ||
451 call->state == AFS_CALL_AWAIT_ACK) &&
452 (skb = skb_dequeue(&call->rx_queue))) {
454 case RXRPC_SKB_MARK_DATA:
456 last = rxrpc_kernel_is_data_last(skb);
457 ret = call->type->deliver(call, skb, last);
461 call->state == AFS_CALL_AWAIT_REPLY)
462 call->state = AFS_CALL_COMPLETE;
465 abort_code = RX_CALL_DEAD;
468 abort_code = RX_INVALID_OPERATION;
471 abort_code = RXGEN_CC_UNMARSHAL;
472 if (call->state != AFS_CALL_AWAIT_REPLY)
473 abort_code = RXGEN_SS_UNMARSHAL;
475 rxrpc_kernel_abort_call(call->rxcall,
478 call->state = AFS_CALL_ERROR;
481 afs_data_delivered(skb);
484 case RXRPC_SKB_MARK_FINAL_ACK:
486 call->state = AFS_CALL_COMPLETE;
488 case RXRPC_SKB_MARK_BUSY:
490 call->error = -EBUSY;
491 call->state = AFS_CALL_BUSY;
493 case RXRPC_SKB_MARK_REMOTE_ABORT:
494 abort_code = rxrpc_kernel_get_abort_code(skb);
495 call->error = call->type->abort_to_error(abort_code);
496 call->state = AFS_CALL_ABORTED;
497 _debug("Rcv ABORT %u -> %d", abort_code, call->error);
499 case RXRPC_SKB_MARK_NET_ERROR:
500 call->error = -rxrpc_kernel_get_error_number(skb);
501 call->state = AFS_CALL_ERROR;
502 _debug("Rcv NET ERROR %d", call->error);
504 case RXRPC_SKB_MARK_LOCAL_ERROR:
505 call->error = -rxrpc_kernel_get_error_number(skb);
506 call->state = AFS_CALL_ERROR;
507 _debug("Rcv LOCAL ERROR %d", call->error);
517 /* make sure the queue is empty if the call is done with (we might have
518 * aborted the call early because of an unmarshalling error) */
519 if (call->state >= AFS_CALL_COMPLETE) {
520 while ((skb = skb_dequeue(&call->rx_queue)))
530 * wait synchronously for a call to complete
532 static int afs_wait_for_call_to_complete(struct afs_call *call)
537 DECLARE_WAITQUEUE(myself, current);
541 add_wait_queue(&call->waitq, &myself);
543 set_current_state(TASK_INTERRUPTIBLE);
545 /* deliver any messages that are in the queue */
546 if (!skb_queue_empty(&call->rx_queue)) {
547 __set_current_state(TASK_RUNNING);
548 afs_deliver_to_call(call);
553 if (call->state >= AFS_CALL_COMPLETE)
556 if (signal_pending(current))
561 remove_wait_queue(&call->waitq, &myself);
562 __set_current_state(TASK_RUNNING);
565 if (call->state < AFS_CALL_COMPLETE) {
566 _debug("call incomplete");
567 rxrpc_kernel_abort_call(call->rxcall, RX_CALL_DEAD);
568 while ((skb = skb_dequeue(&call->rx_queue)))
572 _debug("call complete");
574 _leave(" = %d", ret);
579 * wake up a waiting call
581 static void afs_wake_up_call_waiter(struct afs_call *call)
583 wake_up(&call->waitq);
587 * wake up an asynchronous call
589 static void afs_wake_up_async_call(struct afs_call *call)
592 queue_work(afs_async_calls, &call->async_work);
596 * put a call into asynchronous mode
597 * - mustn't touch the call descriptor as the call my have completed by the
600 static int afs_dont_wait_for_call_to_complete(struct afs_call *call)
607 * delete an asynchronous call
609 static void afs_delete_async_call(struct work_struct *work)
611 struct afs_call *call =
612 container_of(work, struct afs_call, async_work);
622 * perform processing on an asynchronous call
623 * - on a multiple-thread workqueue this work item may try to run on several
624 * CPUs at the same time
626 static void afs_process_async_call(struct work_struct *work)
628 struct afs_call *call =
629 container_of(work, struct afs_call, async_work);
633 if (!skb_queue_empty(&call->rx_queue))
634 afs_deliver_to_call(call);
636 if (call->state >= AFS_CALL_COMPLETE && call->wait_mode) {
637 if (call->wait_mode->async_complete)
638 call->wait_mode->async_complete(call->reply,
643 rxrpc_kernel_end_call(call->rxcall);
645 if (call->type->destructor)
646 call->type->destructor(call);
648 /* we can't just delete the call because the work item may be
650 call->async_workfn = afs_delete_async_call;
651 queue_work(afs_async_calls, &call->async_work);
658 * empty a socket buffer into a flat reply buffer
660 void afs_transfer_reply(struct afs_call *call, struct sk_buff *skb)
662 size_t len = skb->len;
664 if (skb_copy_bits(skb, 0, call->buffer + call->reply_size, len) < 0)
666 call->reply_size += len;
669 static void afs_async_workfn(struct work_struct *work)
671 struct afs_call *call = container_of(work, struct afs_call, async_work);
673 call->async_workfn(work);
677 * accept the backlog of incoming calls
679 static void afs_collect_incoming_call(struct work_struct *work)
681 struct rxrpc_call *rxcall;
682 struct afs_call *call = NULL;
685 while ((skb = skb_dequeue(&afs_incoming_calls))) {
688 /* don't need the notification */
692 call = kzalloc(sizeof(struct afs_call), GFP_KERNEL);
694 rxrpc_kernel_reject_call(afs_socket);
698 call->async_workfn = afs_process_async_call;
699 INIT_WORK(&call->async_work, afs_async_workfn);
700 call->wait_mode = &afs_async_incoming_call;
701 call->type = &afs_RXCMxxxx;
702 init_waitqueue_head(&call->waitq);
703 skb_queue_head_init(&call->rx_queue);
704 call->state = AFS_CALL_AWAIT_OP_ID;
706 _debug("CALL %p{%s} [%d]",
707 call, call->type->name,
708 atomic_read(&afs_outstanding_calls));
709 atomic_inc(&afs_outstanding_calls);
712 rxcall = rxrpc_kernel_accept_call(afs_socket,
713 (unsigned long) call);
714 if (!IS_ERR(rxcall)) {
715 call->rxcall = rxcall;
725 * grab the operation ID from an incoming cache manager call
727 static int afs_deliver_cm_op_id(struct afs_call *call, struct sk_buff *skb,
730 size_t len = skb->len;
731 void *oibuf = (void *) &call->operation_ID;
733 _enter("{%u},{%zu},%d", call->offset, len, last);
735 ASSERTCMP(call->offset, <, 4);
737 /* the operation ID forms the first four bytes of the request data */
738 len = min_t(size_t, len, 4 - call->offset);
739 if (skb_copy_bits(skb, 0, oibuf + call->offset, len) < 0)
741 if (!pskb_pull(skb, len))
745 if (call->offset < 4) {
747 _leave(" = -EBADMSG [op ID short]");
750 _leave(" = 0 [incomplete]");
754 call->state = AFS_CALL_AWAIT_REQUEST;
756 /* ask the cache manager to route the call (it'll change the call type
758 if (!afs_cm_incoming_call(call))
761 /* pass responsibility for the remainer of this message off to the
762 * cache manager op */
763 return call->type->deliver(call, skb, last);
767 * send an empty reply
769 void afs_send_empty_reply(struct afs_call *call)
776 iov[0].iov_base = NULL;
782 msg.msg_control = NULL;
783 msg.msg_controllen = 0;
786 call->state = AFS_CALL_AWAIT_ACK;
787 switch (rxrpc_kernel_send_data(call->rxcall, &msg, 0)) {
789 _leave(" [replied]");
794 rxrpc_kernel_abort_call(call->rxcall, RX_USER_ABORT);
803 * send a simple reply
805 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
813 iov[0].iov_base = (void *) buf;
814 iov[0].iov_len = len;
819 msg.msg_control = NULL;
820 msg.msg_controllen = 0;
823 call->state = AFS_CALL_AWAIT_ACK;
824 n = rxrpc_kernel_send_data(call->rxcall, &msg, len);
827 _leave(" [replied]");
833 rxrpc_kernel_abort_call(call->rxcall, RX_USER_ABORT);
840 * extract a piece of data from the received data socket buffers
842 int afs_extract_data(struct afs_call *call, struct sk_buff *skb,
843 bool last, void *buf, size_t count)
845 size_t len = skb->len;
847 _enter("{%u},{%zu},%d,,%zu", call->offset, len, last, count);
849 ASSERTCMP(call->offset, <, count);
851 len = min_t(size_t, len, count - call->offset);
852 if (skb_copy_bits(skb, 0, buf + call->offset, len) < 0 ||
853 !pskb_pull(skb, len))
857 if (call->offset < count) {
859 _leave(" = -EBADMSG [%d < %zu]", call->offset, count);
862 _leave(" = -EAGAIN");