1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* Maintain an RxRPC server socket to do AFS communications through
3  *
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 
17 struct workqueue_struct *afs_async_calls;
18 
19 static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long);
20 static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long);
21 static void afs_process_async_call(struct work_struct *);
22 static void afs_rx_new_call(struct sock *, struct rxrpc_call *, unsigned long);
23 static void afs_rx_discard_new_call(struct rxrpc_call *, unsigned long);
24 static int afs_deliver_cm_op_id(struct afs_call *);
25 
26 /* asynchronous incoming call initial processing */
27 static const struct afs_call_type afs_RXCMxxxx = {
28 	.name		= "CB.xxxx",
29 	.deliver	= afs_deliver_cm_op_id,
30 };
31 
32 /*
33  * open an RxRPC socket and bind it to be a server for callback notifications
34  * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
35  */
afs_open_socket(struct afs_net * net)36 int afs_open_socket(struct afs_net *net)
37 {
38 	struct sockaddr_rxrpc srx;
39 	struct socket *socket;
40 	int ret;
41 
42 	_enter("");
43 
44 	ret = sock_create_kern(net->net, AF_RXRPC, SOCK_DGRAM, PF_INET6, &socket);
45 	if (ret < 0)
46 		goto error_1;
47 
48 	socket->sk->sk_allocation = GFP_NOFS;
49 
50 	/* bind the callback manager's address to make this a server socket */
51 	memset(&srx, 0, sizeof(srx));
52 	srx.srx_family			= AF_RXRPC;
53 	srx.srx_service			= CM_SERVICE;
54 	srx.transport_type		= SOCK_DGRAM;
55 	srx.transport_len		= sizeof(srx.transport.sin6);
56 	srx.transport.sin6.sin6_family	= AF_INET6;
57 	srx.transport.sin6.sin6_port	= htons(AFS_CM_PORT);
58 
59 	ret = rxrpc_sock_set_min_security_level(socket->sk,
60 						RXRPC_SECURITY_ENCRYPT);
61 	if (ret < 0)
62 		goto error_2;
63 
64 	ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
65 	if (ret == -EADDRINUSE) {
66 		srx.transport.sin6.sin6_port = 0;
67 		ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
68 	}
69 	if (ret < 0)
70 		goto error_2;
71 
72 	srx.srx_service = YFS_CM_SERVICE;
73 	ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
74 	if (ret < 0)
75 		goto error_2;
76 
77 	/* Ideally, we'd turn on service upgrade here, but we can't because
78 	 * OpenAFS is buggy and leaks the userStatus field from packet to
79 	 * packet and between FS packets and CB packets - so if we try to do an
80 	 * upgrade on an FS packet, OpenAFS will leak that into the CB packet
81 	 * it sends back to us.
82 	 */
83 
84 	rxrpc_kernel_new_call_notification(socket, afs_rx_new_call,
85 					   afs_rx_discard_new_call);
86 
87 	ret = kernel_listen(socket, INT_MAX);
88 	if (ret < 0)
89 		goto error_2;
90 
91 	net->socket = socket;
92 	afs_charge_preallocation(&net->charge_preallocation_work);
93 	_leave(" = 0");
94 	return 0;
95 
96 error_2:
97 	sock_release(socket);
98 error_1:
99 	_leave(" = %d", ret);
100 	return ret;
101 }
102 
103 /*
104  * close the RxRPC socket AFS was using
105  */
afs_close_socket(struct afs_net * net)106 void afs_close_socket(struct afs_net *net)
107 {
108 	_enter("");
109 
110 	kernel_listen(net->socket, 0);
111 	flush_workqueue(afs_async_calls);
112 
113 	if (net->spare_incoming_call) {
114 		afs_put_call(net->spare_incoming_call);
115 		net->spare_incoming_call = NULL;
116 	}
117 
118 	_debug("outstanding %u", atomic_read(&net->nr_outstanding_calls));
119 	wait_var_event(&net->nr_outstanding_calls,
120 		       !atomic_read(&net->nr_outstanding_calls));
121 	_debug("no outstanding calls");
122 
123 	kernel_sock_shutdown(net->socket, SHUT_RDWR);
124 	flush_workqueue(afs_async_calls);
125 	sock_release(net->socket);
126 
127 	_debug("dework");
128 	_leave("");
129 }
130 
131 /*
132  * Allocate a call.
133  */
afs_alloc_call(struct afs_net * net,const struct afs_call_type * type,gfp_t gfp)134 static struct afs_call *afs_alloc_call(struct afs_net *net,
135 				       const struct afs_call_type *type,
136 				       gfp_t gfp)
137 {
138 	struct afs_call *call;
139 	int o;
140 
141 	call = kzalloc(sizeof(*call), gfp);
142 	if (!call)
143 		return NULL;
144 
145 	call->type = type;
146 	call->net = net;
147 	call->debug_id = atomic_inc_return(&rxrpc_debug_id);
148 	atomic_set(&call->usage, 1);
149 	INIT_WORK(&call->async_work, afs_process_async_call);
150 	init_waitqueue_head(&call->waitq);
151 	spin_lock_init(&call->state_lock);
152 	call->iter = &call->def_iter;
153 
154 	o = atomic_inc_return(&net->nr_outstanding_calls);
155 	trace_afs_call(call, afs_call_trace_alloc, 1, o,
156 		       __builtin_return_address(0));
157 	return call;
158 }
159 
160 /*
161  * Dispose of a reference on a call.
162  */
afs_put_call(struct afs_call * call)163 void afs_put_call(struct afs_call *call)
164 {
165 	struct afs_net *net = call->net;
166 	int n = atomic_dec_return(&call->usage);
167 	int o = atomic_read(&net->nr_outstanding_calls);
168 
169 	trace_afs_call(call, afs_call_trace_put, n, o,
170 		       __builtin_return_address(0));
171 
172 	ASSERTCMP(n, >=, 0);
173 	if (n == 0) {
174 		ASSERT(!work_pending(&call->async_work));
175 		ASSERT(call->type->name != NULL);
176 
177 		if (call->rxcall) {
178 			rxrpc_kernel_end_call(net->socket, call->rxcall);
179 			call->rxcall = NULL;
180 		}
181 		if (call->type->destructor)
182 			call->type->destructor(call);
183 
184 		afs_unuse_server_notime(call->net, call->server, afs_server_trace_put_call);
185 		afs_put_addrlist(call->alist);
186 		kfree(call->request);
187 
188 		trace_afs_call(call, afs_call_trace_free, 0, o,
189 			       __builtin_return_address(0));
190 		kfree(call);
191 
192 		o = atomic_dec_return(&net->nr_outstanding_calls);
193 		if (o == 0)
194 			wake_up_var(&net->nr_outstanding_calls);
195 	}
196 }
197 
afs_get_call(struct afs_call * call,enum afs_call_trace why)198 static struct afs_call *afs_get_call(struct afs_call *call,
199 				     enum afs_call_trace why)
200 {
201 	int u = atomic_inc_return(&call->usage);
202 
203 	trace_afs_call(call, why, u,
204 		       atomic_read(&call->net->nr_outstanding_calls),
205 		       __builtin_return_address(0));
206 	return call;
207 }
208 
209 /*
210  * Queue the call for actual work.
211  */
afs_queue_call_work(struct afs_call * call)212 static void afs_queue_call_work(struct afs_call *call)
213 {
214 	if (call->type->work) {
215 		INIT_WORK(&call->work, call->type->work);
216 
217 		afs_get_call(call, afs_call_trace_work);
218 		if (!queue_work(afs_wq, &call->work))
219 			afs_put_call(call);
220 	}
221 }
222 
223 /*
224  * allocate a call with flat request and reply buffers
225  */
afs_alloc_flat_call(struct afs_net * net,const struct afs_call_type * type,size_t request_size,size_t reply_max)226 struct afs_call *afs_alloc_flat_call(struct afs_net *net,
227 				     const struct afs_call_type *type,
228 				     size_t request_size, size_t reply_max)
229 {
230 	struct afs_call *call;
231 
232 	call = afs_alloc_call(net, type, GFP_NOFS);
233 	if (!call)
234 		goto nomem_call;
235 
236 	if (request_size) {
237 		call->request_size = request_size;
238 		call->request = kmalloc(request_size, GFP_NOFS);
239 		if (!call->request)
240 			goto nomem_free;
241 	}
242 
243 	if (reply_max) {
244 		call->reply_max = reply_max;
245 		call->buffer = kmalloc(reply_max, GFP_NOFS);
246 		if (!call->buffer)
247 			goto nomem_free;
248 	}
249 
250 	afs_extract_to_buf(call, call->reply_max);
251 	call->operation_ID = type->op;
252 	init_waitqueue_head(&call->waitq);
253 	return call;
254 
255 nomem_free:
256 	afs_put_call(call);
257 nomem_call:
258 	return NULL;
259 }
260 
261 /*
262  * clean up a call with flat buffer
263  */
afs_flat_call_destructor(struct afs_call * call)264 void afs_flat_call_destructor(struct afs_call *call)
265 {
266 	_enter("");
267 
268 	kfree(call->request);
269 	call->request = NULL;
270 	kfree(call->buffer);
271 	call->buffer = NULL;
272 }
273 
274 #define AFS_BVEC_MAX 8
275 
276 /*
277  * Load the given bvec with the next few pages.
278  */
afs_load_bvec(struct afs_call * call,struct msghdr * msg,struct bio_vec * bv,pgoff_t first,pgoff_t last,unsigned offset)279 static void afs_load_bvec(struct afs_call *call, struct msghdr *msg,
280 			  struct bio_vec *bv, pgoff_t first, pgoff_t last,
281 			  unsigned offset)
282 {
283 	struct afs_operation *op = call->op;
284 	struct page *pages[AFS_BVEC_MAX];
285 	unsigned int nr, n, i, to, bytes = 0;
286 
287 	nr = min_t(pgoff_t, last - first + 1, AFS_BVEC_MAX);
288 	n = find_get_pages_contig(op->store.mapping, first, nr, pages);
289 	ASSERTCMP(n, ==, nr);
290 
291 	msg->msg_flags |= MSG_MORE;
292 	for (i = 0; i < nr; i++) {
293 		to = PAGE_SIZE;
294 		if (first + i >= last) {
295 			to = op->store.last_to;
296 			msg->msg_flags &= ~MSG_MORE;
297 		}
298 		bv[i].bv_page = pages[i];
299 		bv[i].bv_len = to - offset;
300 		bv[i].bv_offset = offset;
301 		bytes += to - offset;
302 		offset = 0;
303 	}
304 
305 	iov_iter_bvec(&msg->msg_iter, WRITE, bv, nr, bytes);
306 }
307 
308 /*
309  * Advance the AFS call state when the RxRPC call ends the transmit phase.
310  */
afs_notify_end_request_tx(struct sock * sock,struct rxrpc_call * rxcall,unsigned long call_user_ID)311 static void afs_notify_end_request_tx(struct sock *sock,
312 				      struct rxrpc_call *rxcall,
313 				      unsigned long call_user_ID)
314 {
315 	struct afs_call *call = (struct afs_call *)call_user_ID;
316 
317 	afs_set_call_state(call, AFS_CALL_CL_REQUESTING, AFS_CALL_CL_AWAIT_REPLY);
318 }
319 
320 /*
321  * attach the data from a bunch of pages on an inode to a call
322  */
afs_send_pages(struct afs_call * call,struct msghdr * msg)323 static int afs_send_pages(struct afs_call *call, struct msghdr *msg)
324 {
325 	struct afs_operation *op = call->op;
326 	struct bio_vec bv[AFS_BVEC_MAX];
327 	unsigned int bytes, nr, loop, offset;
328 	pgoff_t first = op->store.first, last = op->store.last;
329 	int ret;
330 
331 	offset = op->store.first_offset;
332 	op->store.first_offset = 0;
333 
334 	do {
335 		afs_load_bvec(call, msg, bv, first, last, offset);
336 		trace_afs_send_pages(call, msg, first, last, offset);
337 
338 		offset = 0;
339 		bytes = msg->msg_iter.count;
340 		nr = msg->msg_iter.nr_segs;
341 
342 		ret = rxrpc_kernel_send_data(op->net->socket, call->rxcall, msg,
343 					     bytes, afs_notify_end_request_tx);
344 		for (loop = 0; loop < nr; loop++)
345 			put_page(bv[loop].bv_page);
346 		if (ret < 0)
347 			break;
348 
349 		first += nr;
350 	} while (first <= last);
351 
352 	trace_afs_sent_pages(call, op->store.first, last, first, ret);
353 	return ret;
354 }
355 
356 /*
357  * Initiate a call and synchronously queue up the parameters for dispatch.  Any
358  * error is stored into the call struct, which the caller must check for.
359  */
afs_make_call(struct afs_addr_cursor * ac,struct afs_call * call,gfp_t gfp)360 void afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call, gfp_t gfp)
361 {
362 	struct sockaddr_rxrpc *srx = &ac->alist->addrs[ac->index];
363 	struct rxrpc_call *rxcall;
364 	struct msghdr msg;
365 	struct kvec iov[1];
366 	s64 tx_total_len;
367 	int ret;
368 
369 	_enter(",{%pISp},", &srx->transport);
370 
371 	ASSERT(call->type != NULL);
372 	ASSERT(call->type->name != NULL);
373 
374 	_debug("____MAKE %p{%s,%x} [%d]____",
375 	       call, call->type->name, key_serial(call->key),
376 	       atomic_read(&call->net->nr_outstanding_calls));
377 
378 	call->addr_ix = ac->index;
379 	call->alist = afs_get_addrlist(ac->alist);
380 
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.
384 	 */
385 	tx_total_len = call->request_size;
386 	if (call->send_pages) {
387 		struct afs_operation *op = call->op;
388 
389 		if (op->store.last == op->store.first) {
390 			tx_total_len += op->store.last_to - op->store.first_offset;
391 		} else {
392 			/* It looks mathematically like you should be able to
393 			 * combine the following lines with the ones above, but
394 			 * unsigned arithmetic is fun when it wraps...
395 			 */
396 			tx_total_len += PAGE_SIZE - op->store.first_offset;
397 			tx_total_len += op->store.last_to;
398 			tx_total_len += (op->store.last - op->store.first - 1) * PAGE_SIZE;
399 		}
400 	}
401 
402 	/* If the call is going to be asynchronous, we need an extra ref for
403 	 * the call to hold itself so the caller need not hang on to its ref.
404 	 */
405 	if (call->async) {
406 		afs_get_call(call, afs_call_trace_get);
407 		call->drop_ref = true;
408 	}
409 
410 	/* create a call */
411 	rxcall = rxrpc_kernel_begin_call(call->net->socket, srx, call->key,
412 					 (unsigned long)call,
413 					 tx_total_len, gfp,
414 					 (call->async ?
415 					  afs_wake_up_async_call :
416 					  afs_wake_up_call_waiter),
417 					 call->upgrade,
418 					 (call->intr ? RXRPC_PREINTERRUPTIBLE :
419 					  RXRPC_UNINTERRUPTIBLE),
420 					 call->debug_id);
421 	if (IS_ERR(rxcall)) {
422 		ret = PTR_ERR(rxcall);
423 		call->error = ret;
424 		goto error_kill_call;
425 	}
426 
427 	call->rxcall = rxcall;
428 
429 	if (call->max_lifespan)
430 		rxrpc_kernel_set_max_life(call->net->socket, rxcall,
431 					  call->max_lifespan);
432 
433 	/* send the request */
434 	iov[0].iov_base	= call->request;
435 	iov[0].iov_len	= call->request_size;
436 
437 	msg.msg_name		= NULL;
438 	msg.msg_namelen		= 0;
439 	iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, call->request_size);
440 	msg.msg_control		= NULL;
441 	msg.msg_controllen	= 0;
442 	msg.msg_flags		= MSG_WAITALL | (call->send_pages ? MSG_MORE : 0);
443 
444 	ret = rxrpc_kernel_send_data(call->net->socket, rxcall,
445 				     &msg, call->request_size,
446 				     afs_notify_end_request_tx);
447 	if (ret < 0)
448 		goto error_do_abort;
449 
450 	if (call->send_pages) {
451 		ret = afs_send_pages(call, &msg);
452 		if (ret < 0)
453 			goto error_do_abort;
454 	}
455 
456 	/* Note that at this point, we may have received the reply or an abort
457 	 * - and an asynchronous call may already have completed.
458 	 *
459 	 * afs_wait_for_call_to_complete(call, ac)
460 	 * must be called to synchronously clean up.
461 	 */
462 	return;
463 
464 error_do_abort:
465 	if (ret != -ECONNABORTED) {
466 		rxrpc_kernel_abort_call(call->net->socket, rxcall,
467 					RX_USER_ABORT, ret, "KSD");
468 	} else {
469 		iov_iter_kvec(&msg.msg_iter, READ, NULL, 0, 0);
470 		rxrpc_kernel_recv_data(call->net->socket, rxcall,
471 				       &msg.msg_iter, false,
472 				       &call->abort_code, &call->service_id);
473 		ac->abort_code = call->abort_code;
474 		ac->responded = true;
475 	}
476 	call->error = ret;
477 	trace_afs_call_done(call);
478 error_kill_call:
479 	if (call->type->done)
480 		call->type->done(call);
481 
482 	/* We need to dispose of the extra ref we grabbed for an async call.
483 	 * The call, however, might be queued on afs_async_calls and we need to
484 	 * make sure we don't get any more notifications that might requeue it.
485 	 */
486 	if (call->rxcall) {
487 		rxrpc_kernel_end_call(call->net->socket, call->rxcall);
488 		call->rxcall = NULL;
489 	}
490 	if (call->async) {
491 		if (cancel_work_sync(&call->async_work))
492 			afs_put_call(call);
493 		afs_put_call(call);
494 	}
495 
496 	ac->error = ret;
497 	call->state = AFS_CALL_COMPLETE;
498 	_leave(" = %d", ret);
499 }
500 
501 /*
502  * deliver messages to a call
503  */
afs_deliver_to_call(struct afs_call * call)504 static void afs_deliver_to_call(struct afs_call *call)
505 {
506 	enum afs_call_state state;
507 	u32 abort_code, remote_abort = 0;
508 	int ret;
509 
510 	_enter("%s", call->type->name);
511 
512 	while (state = READ_ONCE(call->state),
513 	       state == AFS_CALL_CL_AWAIT_REPLY ||
514 	       state == AFS_CALL_SV_AWAIT_OP_ID ||
515 	       state == AFS_CALL_SV_AWAIT_REQUEST ||
516 	       state == AFS_CALL_SV_AWAIT_ACK
517 	       ) {
518 		if (state == AFS_CALL_SV_AWAIT_ACK) {
519 			iov_iter_kvec(&call->def_iter, READ, NULL, 0, 0);
520 			ret = rxrpc_kernel_recv_data(call->net->socket,
521 						     call->rxcall, &call->def_iter,
522 						     false, &remote_abort,
523 						     &call->service_id);
524 			trace_afs_receive_data(call, &call->def_iter, false, ret);
525 
526 			if (ret == -EINPROGRESS || ret == -EAGAIN)
527 				return;
528 			if (ret < 0 || ret == 1) {
529 				if (ret == 1)
530 					ret = 0;
531 				goto call_complete;
532 			}
533 			return;
534 		}
535 
536 		if (!call->have_reply_time &&
537 		    rxrpc_kernel_get_reply_time(call->net->socket,
538 						call->rxcall,
539 						&call->reply_time))
540 			call->have_reply_time = true;
541 
542 		ret = call->type->deliver(call);
543 		state = READ_ONCE(call->state);
544 		if (ret == 0 && call->unmarshalling_error)
545 			ret = -EBADMSG;
546 		switch (ret) {
547 		case 0:
548 			afs_queue_call_work(call);
549 			if (state == AFS_CALL_CL_PROC_REPLY) {
550 				if (call->op)
551 					set_bit(AFS_SERVER_FL_MAY_HAVE_CB,
552 						&call->op->server->flags);
553 				goto call_complete;
554 			}
555 			ASSERTCMP(state, >, AFS_CALL_CL_PROC_REPLY);
556 			goto done;
557 		case -EINPROGRESS:
558 		case -EAGAIN:
559 			goto out;
560 		case -ECONNABORTED:
561 			ASSERTCMP(state, ==, AFS_CALL_COMPLETE);
562 			goto done;
563 		case -ENOTSUPP:
564 			abort_code = RXGEN_OPCODE;
565 			rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
566 						abort_code, ret, "KIV");
567 			goto local_abort;
568 		case -EIO:
569 			pr_err("kAFS: Call %u in bad state %u\n",
570 			       call->debug_id, state);
571 			fallthrough;
572 		case -ENODATA:
573 		case -EBADMSG:
574 		case -EMSGSIZE:
575 			abort_code = RXGEN_CC_UNMARSHAL;
576 			if (state != AFS_CALL_CL_AWAIT_REPLY)
577 				abort_code = RXGEN_SS_UNMARSHAL;
578 			rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
579 						abort_code, ret, "KUM");
580 			goto local_abort;
581 		default:
582 			abort_code = RX_USER_ABORT;
583 			rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
584 						abort_code, ret, "KER");
585 			goto local_abort;
586 		}
587 	}
588 
589 done:
590 	if (call->type->done)
591 		call->type->done(call);
592 out:
593 	_leave("");
594 	return;
595 
596 local_abort:
597 	abort_code = 0;
598 call_complete:
599 	afs_set_call_complete(call, ret, remote_abort);
600 	state = AFS_CALL_COMPLETE;
601 	goto done;
602 }
603 
604 /*
605  * Wait synchronously for a call to complete and clean up the call struct.
606  */
afs_wait_for_call_to_complete(struct afs_call * call,struct afs_addr_cursor * ac)607 long afs_wait_for_call_to_complete(struct afs_call *call,
608 				   struct afs_addr_cursor *ac)
609 {
610 	long ret;
611 	bool rxrpc_complete = false;
612 
613 	DECLARE_WAITQUEUE(myself, current);
614 
615 	_enter("");
616 
617 	ret = call->error;
618 	if (ret < 0)
619 		goto out;
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 	if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {
650 		if (rxrpc_complete) {
651 			afs_set_call_complete(call, call->error, call->abort_code);
652 		} else {
653 			/* Kill off the call if it's still live. */
654 			_debug("call interrupted");
655 			if (rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
656 						    RX_USER_ABORT, -EINTR, "KWI"))
657 				afs_set_call_complete(call, -EINTR, 0);
658 		}
659 	}
660 
661 	spin_lock_bh(&call->state_lock);
662 	ac->abort_code = call->abort_code;
663 	ac->error = call->error;
664 	spin_unlock_bh(&call->state_lock);
665 
666 	ret = ac->error;
667 	switch (ret) {
668 	case 0:
669 		ret = call->ret0;
670 		call->ret0 = 0;
671 
672 		fallthrough;
673 	case -ECONNABORTED:
674 		ac->responded = true;
675 		break;
676 	}
677 
678 out:
679 	_debug("call complete");
680 	afs_put_call(call);
681 	_leave(" = %p", (void *)ret);
682 	return ret;
683 }
684 
685 /*
686  * wake up a waiting call
687  */
afs_wake_up_call_waiter(struct sock * sk,struct rxrpc_call * rxcall,unsigned long call_user_ID)688 static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
689 				    unsigned long call_user_ID)
690 {
691 	struct afs_call *call = (struct afs_call *)call_user_ID;
692 
693 	call->need_attention = true;
694 	wake_up(&call->waitq);
695 }
696 
697 /*
698  * wake up an asynchronous call
699  */
afs_wake_up_async_call(struct sock * sk,struct rxrpc_call * rxcall,unsigned long call_user_ID)700 static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
701 				   unsigned long call_user_ID)
702 {
703 	struct afs_call *call = (struct afs_call *)call_user_ID;
704 	int u;
705 
706 	trace_afs_notify_call(rxcall, call);
707 	call->need_attention = true;
708 
709 	u = atomic_fetch_add_unless(&call->usage, 1, 0);
710 	if (u != 0) {
711 		trace_afs_call(call, afs_call_trace_wake, u + 1,
712 			       atomic_read(&call->net->nr_outstanding_calls),
713 			       __builtin_return_address(0));
714 
715 		if (!queue_work(afs_async_calls, &call->async_work))
716 			afs_put_call(call);
717 	}
718 }
719 
720 /*
721  * Perform I/O processing on an asynchronous call.  The work item carries a ref
722  * to the call struct that we either need to release or to pass on.
723  */
afs_process_async_call(struct work_struct * work)724 static void afs_process_async_call(struct work_struct *work)
725 {
726 	struct afs_call *call = container_of(work, struct afs_call, async_work);
727 
728 	_enter("");
729 
730 	if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
731 		call->need_attention = false;
732 		afs_deliver_to_call(call);
733 	}
734 
735 	afs_put_call(call);
736 	_leave("");
737 }
738 
afs_rx_attach(struct rxrpc_call * rxcall,unsigned long user_call_ID)739 static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
740 {
741 	struct afs_call *call = (struct afs_call *)user_call_ID;
742 
743 	call->rxcall = rxcall;
744 }
745 
746 /*
747  * Charge the incoming call preallocation.
748  */
afs_charge_preallocation(struct work_struct * work)749 void afs_charge_preallocation(struct work_struct *work)
750 {
751 	struct afs_net *net =
752 		container_of(work, struct afs_net, charge_preallocation_work);
753 	struct afs_call *call = net->spare_incoming_call;
754 
755 	for (;;) {
756 		if (!call) {
757 			call = afs_alloc_call(net, &afs_RXCMxxxx, GFP_KERNEL);
758 			if (!call)
759 				break;
760 
761 			call->drop_ref = true;
762 			call->async = true;
763 			call->state = AFS_CALL_SV_AWAIT_OP_ID;
764 			init_waitqueue_head(&call->waitq);
765 			afs_extract_to_tmp(call);
766 		}
767 
768 		if (rxrpc_kernel_charge_accept(net->socket,
769 					       afs_wake_up_async_call,
770 					       afs_rx_attach,
771 					       (unsigned long)call,
772 					       GFP_KERNEL,
773 					       call->debug_id) < 0)
774 			break;
775 		call = NULL;
776 	}
777 	net->spare_incoming_call = call;
778 }
779 
780 /*
781  * Discard a preallocated call when a socket is shut down.
782  */
afs_rx_discard_new_call(struct rxrpc_call * rxcall,unsigned long user_call_ID)783 static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
784 				    unsigned long user_call_ID)
785 {
786 	struct afs_call *call = (struct afs_call *)user_call_ID;
787 
788 	call->rxcall = NULL;
789 	afs_put_call(call);
790 }
791 
792 /*
793  * Notification of an incoming call.
794  */
afs_rx_new_call(struct sock * sk,struct rxrpc_call * rxcall,unsigned long user_call_ID)795 static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
796 			    unsigned long user_call_ID)
797 {
798 	struct afs_net *net = afs_sock2net(sk);
799 
800 	queue_work(afs_wq, &net->charge_preallocation_work);
801 }
802 
803 /*
804  * Grab the operation ID from an incoming cache manager call.  The socket
805  * buffer is discarded on error or if we don't yet have sufficient data.
806  */
afs_deliver_cm_op_id(struct afs_call * call)807 static int afs_deliver_cm_op_id(struct afs_call *call)
808 {
809 	int ret;
810 
811 	_enter("{%zu}", iov_iter_count(call->iter));
812 
813 	/* the operation ID forms the first four bytes of the request data */
814 	ret = afs_extract_data(call, true);
815 	if (ret < 0)
816 		return ret;
817 
818 	call->operation_ID = ntohl(call->tmp);
819 	afs_set_call_state(call, AFS_CALL_SV_AWAIT_OP_ID, AFS_CALL_SV_AWAIT_REQUEST);
820 
821 	/* ask the cache manager to route the call (it'll change the call type
822 	 * if successful) */
823 	if (!afs_cm_incoming_call(call))
824 		return -ENOTSUPP;
825 
826 	trace_afs_cb_call(call);
827 
828 	/* pass responsibility for the remainer of this message off to the
829 	 * cache manager op */
830 	return call->type->deliver(call);
831 }
832 
833 /*
834  * Advance the AFS call state when an RxRPC service call ends the transmit
835  * phase.
836  */
afs_notify_end_reply_tx(struct sock * sock,struct rxrpc_call * rxcall,unsigned long call_user_ID)837 static void afs_notify_end_reply_tx(struct sock *sock,
838 				    struct rxrpc_call *rxcall,
839 				    unsigned long call_user_ID)
840 {
841 	struct afs_call *call = (struct afs_call *)call_user_ID;
842 
843 	afs_set_call_state(call, AFS_CALL_SV_REPLYING, AFS_CALL_SV_AWAIT_ACK);
844 }
845 
846 /*
847  * send an empty reply
848  */
afs_send_empty_reply(struct afs_call * call)849 void afs_send_empty_reply(struct afs_call *call)
850 {
851 	struct afs_net *net = call->net;
852 	struct msghdr msg;
853 
854 	_enter("");
855 
856 	rxrpc_kernel_set_tx_length(net->socket, call->rxcall, 0);
857 
858 	msg.msg_name		= NULL;
859 	msg.msg_namelen		= 0;
860 	iov_iter_kvec(&msg.msg_iter, WRITE, NULL, 0, 0);
861 	msg.msg_control		= NULL;
862 	msg.msg_controllen	= 0;
863 	msg.msg_flags		= 0;
864 
865 	switch (rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, 0,
866 				       afs_notify_end_reply_tx)) {
867 	case 0:
868 		_leave(" [replied]");
869 		return;
870 
871 	case -ENOMEM:
872 		_debug("oom");
873 		rxrpc_kernel_abort_call(net->socket, call->rxcall,
874 					RX_USER_ABORT, -ENOMEM, "KOO");
875 		fallthrough;
876 	default:
877 		_leave(" [error]");
878 		return;
879 	}
880 }
881 
882 /*
883  * send a simple reply
884  */
afs_send_simple_reply(struct afs_call * call,const void * buf,size_t len)885 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
886 {
887 	struct afs_net *net = call->net;
888 	struct msghdr msg;
889 	struct kvec iov[1];
890 	int n;
891 
892 	_enter("");
893 
894 	rxrpc_kernel_set_tx_length(net->socket, call->rxcall, len);
895 
896 	iov[0].iov_base		= (void *) buf;
897 	iov[0].iov_len		= len;
898 	msg.msg_name		= NULL;
899 	msg.msg_namelen		= 0;
900 	iov_iter_kvec(&msg.msg_iter, WRITE, iov, 1, len);
901 	msg.msg_control		= NULL;
902 	msg.msg_controllen	= 0;
903 	msg.msg_flags		= 0;
904 
905 	n = rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, len,
906 				   afs_notify_end_reply_tx);
907 	if (n >= 0) {
908 		/* Success */
909 		_leave(" [replied]");
910 		return;
911 	}
912 
913 	if (n == -ENOMEM) {
914 		_debug("oom");
915 		rxrpc_kernel_abort_call(net->socket, call->rxcall,
916 					RX_USER_ABORT, -ENOMEM, "KOO");
917 	}
918 	_leave(" [error]");
919 }
920 
921 /*
922  * Extract a piece of data from the received data socket buffers.
923  */
afs_extract_data(struct afs_call * call,bool want_more)924 int afs_extract_data(struct afs_call *call, bool want_more)
925 {
926 	struct afs_net *net = call->net;
927 	struct iov_iter *iter = call->iter;
928 	enum afs_call_state state;
929 	u32 remote_abort = 0;
930 	int ret;
931 
932 	_enter("{%s,%zu},%d", call->type->name, iov_iter_count(iter), want_more);
933 
934 	ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, iter,
935 				     want_more, &remote_abort,
936 				     &call->service_id);
937 	if (ret == 0 || ret == -EAGAIN)
938 		return ret;
939 
940 	state = READ_ONCE(call->state);
941 	if (ret == 1) {
942 		switch (state) {
943 		case AFS_CALL_CL_AWAIT_REPLY:
944 			afs_set_call_state(call, state, AFS_CALL_CL_PROC_REPLY);
945 			break;
946 		case AFS_CALL_SV_AWAIT_REQUEST:
947 			afs_set_call_state(call, state, AFS_CALL_SV_REPLYING);
948 			break;
949 		case AFS_CALL_COMPLETE:
950 			kdebug("prem complete %d", call->error);
951 			return afs_io_error(call, afs_io_error_extract);
952 		default:
953 			break;
954 		}
955 		return 0;
956 	}
957 
958 	afs_set_call_complete(call, ret, remote_abort);
959 	return ret;
960 }
961 
962 /*
963  * Log protocol error production.
964  */
afs_protocol_error(struct afs_call * call,enum afs_eproto_cause cause)965 noinline int afs_protocol_error(struct afs_call *call,
966 				enum afs_eproto_cause cause)
967 {
968 	trace_afs_protocol_error(call, cause);
969 	if (call)
970 		call->unmarshalling_error = true;
971 	return -EBADMSG;
972 }
973