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>
13 #include <linux/sched/signal.h>
16 #include <net/af_rxrpc.h>
20 struct socket *afs_socket; /* my RxRPC socket */
21 static struct workqueue_struct *afs_async_calls;
22 static struct afs_call *afs_spare_incoming_call;
23 atomic_t afs_outstanding_calls;
25 static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long);
26 static int afs_wait_for_call_to_complete(struct afs_call *);
27 static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long);
28 static void afs_process_async_call(struct work_struct *);
29 static void afs_rx_new_call(struct sock *, struct rxrpc_call *, unsigned long);
30 static void afs_rx_discard_new_call(struct rxrpc_call *, unsigned long);
31 static int afs_deliver_cm_op_id(struct afs_call *);
33 /* asynchronous incoming call initial processing */
34 static const struct afs_call_type afs_RXCMxxxx = {
36 .deliver = afs_deliver_cm_op_id,
37 .abort_to_error = afs_abort_to_error,
40 static void afs_charge_preallocation(struct work_struct *);
42 static DECLARE_WORK(afs_charge_preallocation_work, afs_charge_preallocation);
44 static int afs_wait_atomic_t(atomic_t *p)
51 * open an RxRPC socket and bind it to be a server for callback notifications
52 * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
54 int afs_open_socket(void)
56 struct sockaddr_rxrpc srx;
57 struct socket *socket;
58 unsigned int min_level;
64 afs_async_calls = alloc_workqueue("kafsd", WQ_MEM_RECLAIM, 0);
68 ret = sock_create_kern(&init_net, AF_RXRPC, SOCK_DGRAM, PF_INET, &socket);
72 socket->sk->sk_allocation = GFP_NOFS;
74 /* bind the callback manager's address to make this a server socket */
75 srx.srx_family = AF_RXRPC;
76 srx.srx_service = CM_SERVICE;
77 srx.transport_type = SOCK_DGRAM;
78 srx.transport_len = sizeof(srx.transport.sin);
79 srx.transport.sin.sin_family = AF_INET;
80 srx.transport.sin.sin_port = htons(AFS_CM_PORT);
81 memset(&srx.transport.sin.sin_addr, 0,
82 sizeof(srx.transport.sin.sin_addr));
84 min_level = RXRPC_SECURITY_ENCRYPT;
85 ret = kernel_setsockopt(socket, SOL_RXRPC, RXRPC_MIN_SECURITY_LEVEL,
86 (void *)&min_level, sizeof(min_level));
90 ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
94 rxrpc_kernel_new_call_notification(socket, afs_rx_new_call,
95 afs_rx_discard_new_call);
97 ret = kernel_listen(socket, INT_MAX);
102 afs_charge_preallocation(NULL);
107 sock_release(socket);
109 destroy_workqueue(afs_async_calls);
111 _leave(" = %d", ret);
116 * close the RxRPC socket AFS was using
118 void afs_close_socket(void)
122 kernel_listen(afs_socket, 0);
123 flush_workqueue(afs_async_calls);
125 if (afs_spare_incoming_call) {
126 afs_put_call(afs_spare_incoming_call);
127 afs_spare_incoming_call = NULL;
130 _debug("outstanding %u", atomic_read(&afs_outstanding_calls));
131 wait_on_atomic_t(&afs_outstanding_calls, afs_wait_atomic_t,
132 TASK_UNINTERRUPTIBLE);
133 _debug("no outstanding calls");
135 kernel_sock_shutdown(afs_socket, SHUT_RDWR);
136 flush_workqueue(afs_async_calls);
137 sock_release(afs_socket);
140 destroy_workqueue(afs_async_calls);
147 static struct afs_call *afs_alloc_call(const struct afs_call_type *type,
150 struct afs_call *call;
153 call = kzalloc(sizeof(*call), gfp);
158 atomic_set(&call->usage, 1);
159 INIT_WORK(&call->async_work, afs_process_async_call);
160 init_waitqueue_head(&call->waitq);
162 o = atomic_inc_return(&afs_outstanding_calls);
163 trace_afs_call(call, afs_call_trace_alloc, 1, o,
164 __builtin_return_address(0));
169 * Dispose of a reference on a call.
171 void afs_put_call(struct afs_call *call)
173 int n = atomic_dec_return(&call->usage);
174 int o = atomic_read(&afs_outstanding_calls);
176 trace_afs_call(call, afs_call_trace_put, n, o,
177 __builtin_return_address(0));
181 ASSERT(!work_pending(&call->async_work));
182 ASSERT(call->type->name != NULL);
185 rxrpc_kernel_end_call(afs_socket, call->rxcall);
188 if (call->type->destructor)
189 call->type->destructor(call);
191 kfree(call->request);
194 o = atomic_dec_return(&afs_outstanding_calls);
195 trace_afs_call(call, afs_call_trace_free, 0, o,
196 __builtin_return_address(0));
198 wake_up_atomic_t(&afs_outstanding_calls);
203 * Queue the call for actual work. Returns 0 unconditionally for convenience.
205 int afs_queue_call_work(struct afs_call *call)
207 int u = atomic_inc_return(&call->usage);
209 trace_afs_call(call, afs_call_trace_work, u,
210 atomic_read(&afs_outstanding_calls),
211 __builtin_return_address(0));
213 INIT_WORK(&call->work, call->type->work);
215 if (!queue_work(afs_wq, &call->work))
221 * allocate a call with flat request and reply buffers
223 struct afs_call *afs_alloc_flat_call(const struct afs_call_type *type,
224 size_t request_size, size_t reply_max)
226 struct afs_call *call;
228 call = afs_alloc_call(type, GFP_NOFS);
233 call->request_size = request_size;
234 call->request = kmalloc(request_size, GFP_NOFS);
240 call->reply_max = reply_max;
241 call->buffer = kmalloc(reply_max, GFP_NOFS);
246 init_waitqueue_head(&call->waitq);
256 * clean up a call with flat buffer
258 void afs_flat_call_destructor(struct afs_call *call)
262 kfree(call->request);
263 call->request = NULL;
268 #define AFS_BVEC_MAX 8
271 * Load the given bvec with the next few pages.
273 static void afs_load_bvec(struct afs_call *call, struct msghdr *msg,
274 struct bio_vec *bv, pgoff_t first, pgoff_t last,
277 struct page *pages[AFS_BVEC_MAX];
278 unsigned int nr, n, i, to, bytes = 0;
280 nr = min_t(pgoff_t, last - first + 1, AFS_BVEC_MAX);
281 n = find_get_pages_contig(call->mapping, first, nr, pages);
282 ASSERTCMP(n, ==, nr);
284 msg->msg_flags |= MSG_MORE;
285 for (i = 0; i < nr; i++) {
287 if (first + i >= last) {
289 msg->msg_flags &= ~MSG_MORE;
291 bv[i].bv_page = pages[i];
292 bv[i].bv_len = to - offset;
293 bv[i].bv_offset = offset;
294 bytes += to - offset;
298 iov_iter_bvec(&msg->msg_iter, WRITE | ITER_BVEC, bv, nr, bytes);
302 * Advance the AFS call state when the RxRPC call ends the transmit phase.
304 static void afs_notify_end_request_tx(struct sock *sock,
305 struct rxrpc_call *rxcall,
306 unsigned long call_user_ID)
308 struct afs_call *call = (struct afs_call *)call_user_ID;
310 if (call->state == AFS_CALL_REQUESTING)
311 call->state = AFS_CALL_AWAIT_REPLY;
315 * attach the data from a bunch of pages on an inode to a call
317 static int afs_send_pages(struct afs_call *call, struct msghdr *msg)
319 struct bio_vec bv[AFS_BVEC_MAX];
320 unsigned int bytes, nr, loop, offset;
321 pgoff_t first = call->first, last = call->last;
324 offset = call->first_offset;
325 call->first_offset = 0;
328 afs_load_bvec(call, msg, bv, first, last, offset);
330 bytes = msg->msg_iter.count;
331 nr = msg->msg_iter.nr_segs;
333 ret = rxrpc_kernel_send_data(afs_socket, call->rxcall, msg,
334 bytes, afs_notify_end_request_tx);
335 for (loop = 0; loop < nr; loop++)
336 put_page(bv[loop].bv_page);
341 } while (first <= last);
349 int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp,
352 struct sockaddr_rxrpc srx;
353 struct rxrpc_call *rxcall;
361 _enter("%x,{%d},", addr->s_addr, ntohs(call->port));
363 ASSERT(call->type != NULL);
364 ASSERT(call->type->name != NULL);
366 _debug("____MAKE %p{%s,%x} [%d]____",
367 call, call->type->name, key_serial(call->key),
368 atomic_read(&afs_outstanding_calls));
372 memset(&srx, 0, sizeof(srx));
373 srx.srx_family = AF_RXRPC;
374 srx.srx_service = call->service_id;
375 srx.transport_type = SOCK_DGRAM;
376 srx.transport_len = sizeof(srx.transport.sin);
377 srx.transport.sin.sin_family = AF_INET;
378 srx.transport.sin.sin_port = call->port;
379 memcpy(&srx.transport.sin.sin_addr, addr, 4);
381 /* Work out the length we're going to transmit. This is awkward for
382 * calls such as FS.StoreData where there's an extra injection of data
383 * after the initial fixed part.
385 tx_total_len = call->request_size;
386 if (call->send_pages) {
387 if (call->last == call->first) {
388 tx_total_len += call->last_to - call->first_offset;
390 /* It looks mathematically like you should be able to
391 * combine the following lines with the ones above, but
392 * unsigned arithmetic is fun when it wraps...
394 tx_total_len += PAGE_SIZE - call->first_offset;
395 tx_total_len += call->last_to;
396 tx_total_len += (call->last - call->first - 1) * PAGE_SIZE;
401 rxcall = rxrpc_kernel_begin_call(afs_socket, &srx, call->key,
405 afs_wake_up_async_call :
406 afs_wake_up_call_waiter));
408 if (IS_ERR(rxcall)) {
409 ret = PTR_ERR(rxcall);
410 goto error_kill_call;
413 call->rxcall = rxcall;
415 /* send the request */
416 iov[0].iov_base = call->request;
417 iov[0].iov_len = call->request_size;
421 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1,
423 msg.msg_control = NULL;
424 msg.msg_controllen = 0;
425 msg.msg_flags = (call->send_pages ? MSG_MORE : 0);
427 /* We have to change the state *before* sending the last packet as
428 * rxrpc might give us the reply before it returns from sending the
429 * request. Further, if the send fails, we may already have been given
430 * a notification and may have collected it.
432 if (!call->send_pages)
433 call->state = AFS_CALL_AWAIT_REPLY;
434 ret = rxrpc_kernel_send_data(afs_socket, rxcall,
435 &msg, call->request_size,
436 afs_notify_end_request_tx);
440 if (call->send_pages) {
441 ret = afs_send_pages(call, &msg);
446 /* at this point, an async call may no longer exist as it may have
447 * already completed */
451 return afs_wait_for_call_to_complete(call);
454 call->state = AFS_CALL_COMPLETE;
455 if (ret != -ECONNABORTED) {
456 rxrpc_kernel_abort_call(afs_socket, rxcall, RX_USER_ABORT,
461 rxrpc_kernel_recv_data(afs_socket, rxcall, NULL, 0, &offset,
463 ret = call->type->abort_to_error(abort_code);
467 _leave(" = %d", ret);
472 * deliver messages to a call
474 static void afs_deliver_to_call(struct afs_call *call)
479 _enter("%s", call->type->name);
481 while (call->state == AFS_CALL_AWAIT_REPLY ||
482 call->state == AFS_CALL_AWAIT_OP_ID ||
483 call->state == AFS_CALL_AWAIT_REQUEST ||
484 call->state == AFS_CALL_AWAIT_ACK
486 if (call->state == AFS_CALL_AWAIT_ACK) {
488 ret = rxrpc_kernel_recv_data(afs_socket, call->rxcall,
489 NULL, 0, &offset, false,
491 trace_afs_recv_data(call, 0, offset, false, ret);
493 if (ret == -EINPROGRESS || ret == -EAGAIN)
495 if (ret == 1 || ret < 0) {
496 call->state = AFS_CALL_COMPLETE;
502 ret = call->type->deliver(call);
505 if (call->state == AFS_CALL_AWAIT_REPLY)
506 call->state = AFS_CALL_COMPLETE;
514 abort_code = RX_CALL_DEAD;
515 rxrpc_kernel_abort_call(afs_socket, call->rxcall,
516 abort_code, ret, "KNC");
519 abort_code = RXGEN_OPCODE;
520 rxrpc_kernel_abort_call(afs_socket, call->rxcall,
521 abort_code, ret, "KIV");
527 abort_code = RXGEN_CC_UNMARSHAL;
528 if (call->state != AFS_CALL_AWAIT_REPLY)
529 abort_code = RXGEN_SS_UNMARSHAL;
530 rxrpc_kernel_abort_call(afs_socket, call->rxcall,
531 abort_code, -EBADMSG, "KUM");
537 if (call->state == AFS_CALL_COMPLETE && call->incoming)
546 call->state = AFS_CALL_COMPLETE;
551 * wait synchronously for a call to complete
553 static int afs_wait_for_call_to_complete(struct afs_call *call)
557 DECLARE_WAITQUEUE(myself, current);
561 add_wait_queue(&call->waitq, &myself);
563 set_current_state(TASK_INTERRUPTIBLE);
565 /* deliver any messages that are in the queue */
566 if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
567 call->need_attention = false;
568 __set_current_state(TASK_RUNNING);
569 afs_deliver_to_call(call);
573 if (call->state == AFS_CALL_COMPLETE ||
574 signal_pending(current))
579 remove_wait_queue(&call->waitq, &myself);
580 __set_current_state(TASK_RUNNING);
582 /* Kill off the call if it's still live. */
583 if (call->state < AFS_CALL_COMPLETE) {
584 _debug("call interrupted");
585 rxrpc_kernel_abort_call(afs_socket, call->rxcall,
586 RX_USER_ABORT, -EINTR, "KWI");
590 _debug("call complete");
592 _leave(" = %d", ret);
597 * wake up a waiting call
599 static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
600 unsigned long call_user_ID)
602 struct afs_call *call = (struct afs_call *)call_user_ID;
604 call->need_attention = true;
605 wake_up(&call->waitq);
609 * wake up an asynchronous call
611 static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
612 unsigned long call_user_ID)
614 struct afs_call *call = (struct afs_call *)call_user_ID;
617 trace_afs_notify_call(rxcall, call);
618 call->need_attention = true;
620 u = __atomic_add_unless(&call->usage, 1, 0);
622 trace_afs_call(call, afs_call_trace_wake, u + 1,
623 atomic_read(&afs_outstanding_calls),
624 __builtin_return_address(0));
626 if (!queue_work(afs_async_calls, &call->async_work))
632 * Delete an asynchronous call. The work item carries a ref to the call struct
633 * that we need to release.
635 static void afs_delete_async_call(struct work_struct *work)
637 struct afs_call *call = container_of(work, struct afs_call, async_work);
647 * Perform I/O processing on an asynchronous call. The work item carries a ref
648 * to the call struct that we either need to release or to pass on.
650 static void afs_process_async_call(struct work_struct *work)
652 struct afs_call *call = container_of(work, struct afs_call, async_work);
656 if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
657 call->need_attention = false;
658 afs_deliver_to_call(call);
661 if (call->state == AFS_CALL_COMPLETE) {
664 /* We have two refs to release - one from the alloc and one
665 * queued with the work item - and we can't just deallocate the
666 * call because the work item may be queued again.
668 call->async_work.func = afs_delete_async_call;
669 if (!queue_work(afs_async_calls, &call->async_work))
677 static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
679 struct afs_call *call = (struct afs_call *)user_call_ID;
681 call->rxcall = rxcall;
685 * Charge the incoming call preallocation.
687 static void afs_charge_preallocation(struct work_struct *work)
689 struct afs_call *call = afs_spare_incoming_call;
693 call = afs_alloc_call(&afs_RXCMxxxx, GFP_KERNEL);
698 call->state = AFS_CALL_AWAIT_OP_ID;
699 init_waitqueue_head(&call->waitq);
702 if (rxrpc_kernel_charge_accept(afs_socket,
703 afs_wake_up_async_call,
710 afs_spare_incoming_call = call;
714 * Discard a preallocated call when a socket is shut down.
716 static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
717 unsigned long user_call_ID)
719 struct afs_call *call = (struct afs_call *)user_call_ID;
726 * Notification of an incoming call.
728 static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
729 unsigned long user_call_ID)
731 queue_work(afs_wq, &afs_charge_preallocation_work);
735 * Grab the operation ID from an incoming cache manager call. The socket
736 * buffer is discarded on error or if we don't yet have sufficient data.
738 static int afs_deliver_cm_op_id(struct afs_call *call)
742 _enter("{%zu}", call->offset);
744 ASSERTCMP(call->offset, <, 4);
746 /* the operation ID forms the first four bytes of the request data */
747 ret = afs_extract_data(call, &call->tmp, 4, true);
751 call->operation_ID = ntohl(call->tmp);
752 call->state = AFS_CALL_AWAIT_REQUEST;
755 /* ask the cache manager to route the call (it'll change the call type
757 if (!afs_cm_incoming_call(call))
760 trace_afs_cb_call(call);
762 /* pass responsibility for the remainer of this message off to the
763 * cache manager op */
764 return call->type->deliver(call);
768 * Advance the AFS call state when an RxRPC service call ends the transmit
771 static void afs_notify_end_reply_tx(struct sock *sock,
772 struct rxrpc_call *rxcall,
773 unsigned long call_user_ID)
775 struct afs_call *call = (struct afs_call *)call_user_ID;
777 if (call->state == AFS_CALL_REPLYING)
778 call->state = AFS_CALL_AWAIT_ACK;
782 * send an empty reply
784 void afs_send_empty_reply(struct afs_call *call)
790 rxrpc_kernel_set_tx_length(afs_socket, call->rxcall, 0);
794 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, NULL, 0, 0);
795 msg.msg_control = NULL;
796 msg.msg_controllen = 0;
799 call->state = AFS_CALL_AWAIT_ACK;
800 switch (rxrpc_kernel_send_data(afs_socket, call->rxcall, &msg, 0,
801 afs_notify_end_reply_tx)) {
803 _leave(" [replied]");
808 rxrpc_kernel_abort_call(afs_socket, call->rxcall,
809 RX_USER_ABORT, -ENOMEM, "KOO");
817 * send a simple reply
819 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
827 rxrpc_kernel_set_tx_length(afs_socket, call->rxcall, len);
829 iov[0].iov_base = (void *) buf;
830 iov[0].iov_len = len;
833 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, iov, 1, len);
834 msg.msg_control = NULL;
835 msg.msg_controllen = 0;
838 call->state = AFS_CALL_AWAIT_ACK;
839 n = rxrpc_kernel_send_data(afs_socket, call->rxcall, &msg, len,
840 afs_notify_end_reply_tx);
843 _leave(" [replied]");
849 rxrpc_kernel_abort_call(afs_socket, call->rxcall,
850 RX_USER_ABORT, -ENOMEM, "KOO");
856 * Extract a piece of data from the received data socket buffers.
858 int afs_extract_data(struct afs_call *call, void *buf, size_t count,
863 _enter("{%s,%zu},,%zu,%d",
864 call->type->name, call->offset, count, want_more);
866 ASSERTCMP(call->offset, <=, count);
868 ret = rxrpc_kernel_recv_data(afs_socket, call->rxcall,
869 buf, count, &call->offset,
870 want_more, &call->abort_code);
871 trace_afs_recv_data(call, count, call->offset, want_more, ret);
872 if (ret == 0 || ret == -EAGAIN)
876 switch (call->state) {
877 case AFS_CALL_AWAIT_REPLY:
878 call->state = AFS_CALL_COMPLETE;
880 case AFS_CALL_AWAIT_REQUEST:
881 call->state = AFS_CALL_REPLYING;
889 if (ret == -ECONNABORTED)
890 call->error = call->type->abort_to_error(call->abort_code);
893 call->state = AFS_CALL_COMPLETE;