xref: /linux/fs/afs/rxrpc.c (revision ab93e0dd72c37d378dd936f031ffb83ff2bd87ce)
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 #define RXRPC_TRACE_ONLY_DEFINE_ENUMS
17 #include <trace/events/rxrpc.h>
18 
19 struct workqueue_struct *afs_async_calls;
20 
21 static void afs_deferred_free_worker(struct work_struct *work);
22 static void afs_wake_up_call_waiter(struct sock *, struct rxrpc_call *, unsigned long);
23 static void afs_wake_up_async_call(struct sock *, struct rxrpc_call *, unsigned long);
24 static void afs_process_async_call(struct work_struct *);
25 static void afs_rx_new_call(struct sock *, struct rxrpc_call *, unsigned long);
26 static void afs_rx_discard_new_call(struct rxrpc_call *, unsigned long);
27 static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID);
28 static void afs_rx_notify_oob(struct sock *sk, struct sk_buff *oob);
29 static int afs_deliver_cm_op_id(struct afs_call *);
30 
31 static const struct rxrpc_kernel_ops afs_rxrpc_callback_ops = {
32 	.notify_new_call	= afs_rx_new_call,
33 	.discard_new_call	= afs_rx_discard_new_call,
34 	.user_attach_call	= afs_rx_attach,
35 	.notify_oob		= afs_rx_notify_oob,
36 };
37 
38 /* asynchronous incoming call initial processing */
39 static const struct afs_call_type afs_RXCMxxxx = {
40 	.name		= "CB.xxxx",
41 	.deliver	= afs_deliver_cm_op_id,
42 };
43 
44 /*
45  * open an RxRPC socket and bind it to be a server for callback notifications
46  * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT
47  */
afs_open_socket(struct afs_net * net)48 int afs_open_socket(struct afs_net *net)
49 {
50 	struct sockaddr_rxrpc srx;
51 	struct socket *socket;
52 	int ret;
53 
54 	_enter("");
55 
56 	ret = sock_create_kern(net->net, AF_RXRPC, SOCK_DGRAM, PF_INET6, &socket);
57 	if (ret < 0)
58 		goto error_1;
59 
60 	socket->sk->sk_allocation = GFP_NOFS;
61 	socket->sk->sk_user_data = net;
62 
63 	/* bind the callback manager's address to make this a server socket */
64 	memset(&srx, 0, sizeof(srx));
65 	srx.srx_family			= AF_RXRPC;
66 	srx.srx_service			= CM_SERVICE;
67 	srx.transport_type		= SOCK_DGRAM;
68 	srx.transport_len		= sizeof(srx.transport.sin6);
69 	srx.transport.sin6.sin6_family	= AF_INET6;
70 	srx.transport.sin6.sin6_port	= htons(AFS_CM_PORT);
71 
72 	ret = rxrpc_sock_set_min_security_level(socket->sk,
73 						RXRPC_SECURITY_ENCRYPT);
74 	if (ret < 0)
75 		goto error_2;
76 
77 	ret = rxrpc_sock_set_manage_response(socket->sk, true);
78 	if (ret < 0)
79 		goto error_2;
80 
81 	ret = afs_create_token_key(net, socket);
82 	if (ret < 0)
83 		pr_err("Couldn't create RxGK CM key: %d\n", ret);
84 
85 	ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
86 	if (ret == -EADDRINUSE) {
87 		srx.transport.sin6.sin6_port = 0;
88 		ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
89 	}
90 	if (ret < 0)
91 		goto error_2;
92 
93 	srx.srx_service = YFS_CM_SERVICE;
94 	ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
95 	if (ret < 0)
96 		goto error_2;
97 
98 	/* Ideally, we'd turn on service upgrade here, but we can't because
99 	 * OpenAFS is buggy and leaks the userStatus field from packet to
100 	 * packet and between FS packets and CB packets - so if we try to do an
101 	 * upgrade on an FS packet, OpenAFS will leak that into the CB packet
102 	 * it sends back to us.
103 	 */
104 
105 	rxrpc_kernel_set_notifications(socket, &afs_rxrpc_callback_ops);
106 
107 	ret = kernel_listen(socket, INT_MAX);
108 	if (ret < 0)
109 		goto error_2;
110 
111 	net->socket = socket;
112 	afs_charge_preallocation(&net->charge_preallocation_work);
113 	_leave(" = 0");
114 	return 0;
115 
116 error_2:
117 	sock_release(socket);
118 error_1:
119 	_leave(" = %d", ret);
120 	return ret;
121 }
122 
123 /*
124  * close the RxRPC socket AFS was using
125  */
afs_close_socket(struct afs_net * net)126 void afs_close_socket(struct afs_net *net)
127 {
128 	_enter("");
129 
130 	kernel_listen(net->socket, 0);
131 	flush_workqueue(afs_async_calls);
132 
133 	if (net->spare_incoming_call) {
134 		afs_put_call(net->spare_incoming_call);
135 		net->spare_incoming_call = NULL;
136 	}
137 
138 	_debug("outstanding %u", atomic_read(&net->nr_outstanding_calls));
139 	wait_var_event(&net->nr_outstanding_calls,
140 		       !atomic_read(&net->nr_outstanding_calls));
141 	_debug("no outstanding calls");
142 
143 	kernel_sock_shutdown(net->socket, SHUT_RDWR);
144 	flush_workqueue(afs_async_calls);
145 	net->socket->sk->sk_user_data = NULL;
146 	sock_release(net->socket);
147 	key_put(net->fs_cm_token_key);
148 
149 	_debug("dework");
150 	_leave("");
151 }
152 
153 /*
154  * Allocate a call.
155  */
afs_alloc_call(struct afs_net * net,const struct afs_call_type * type,gfp_t gfp)156 static struct afs_call *afs_alloc_call(struct afs_net *net,
157 				       const struct afs_call_type *type,
158 				       gfp_t gfp)
159 {
160 	struct afs_call *call;
161 	int o;
162 
163 	call = kzalloc(sizeof(*call), gfp);
164 	if (!call)
165 		return NULL;
166 
167 	call->type = type;
168 	call->net = net;
169 	call->debug_id = atomic_inc_return(&rxrpc_debug_id);
170 	refcount_set(&call->ref, 1);
171 	INIT_WORK(&call->async_work, type->async_rx ?: afs_process_async_call);
172 	INIT_WORK(&call->work, call->type->work);
173 	INIT_WORK(&call->free_work, afs_deferred_free_worker);
174 	init_waitqueue_head(&call->waitq);
175 	spin_lock_init(&call->state_lock);
176 	call->iter = &call->def_iter;
177 
178 	o = atomic_inc_return(&net->nr_outstanding_calls);
179 	trace_afs_call(call->debug_id, afs_call_trace_alloc, 1, o,
180 		       __builtin_return_address(0));
181 	return call;
182 }
183 
afs_free_call(struct afs_call * call)184 static void afs_free_call(struct afs_call *call)
185 {
186 	struct afs_net *net = call->net;
187 	int o;
188 
189 	ASSERT(!work_pending(&call->async_work));
190 
191 	rxrpc_kernel_put_peer(call->peer);
192 
193 	if (call->rxcall) {
194 		rxrpc_kernel_shutdown_call(net->socket, call->rxcall);
195 		rxrpc_kernel_put_call(net->socket, call->rxcall);
196 		call->rxcall = NULL;
197 	}
198 	if (call->type->destructor)
199 		call->type->destructor(call);
200 
201 	afs_unuse_server_notime(call->net, call->server, afs_server_trace_unuse_call);
202 	kfree(call->request);
203 
204 	o = atomic_read(&net->nr_outstanding_calls);
205 	trace_afs_call(call->debug_id, afs_call_trace_free, 0, o,
206 		       __builtin_return_address(0));
207 	kfree(call);
208 
209 	o = atomic_dec_return(&net->nr_outstanding_calls);
210 	if (o == 0)
211 		wake_up_var(&net->nr_outstanding_calls);
212 }
213 
214 /*
215  * Dispose of a reference on a call.
216  */
afs_put_call(struct afs_call * call)217 void afs_put_call(struct afs_call *call)
218 {
219 	struct afs_net *net = call->net;
220 	unsigned int debug_id = call->debug_id;
221 	bool zero;
222 	int r, o;
223 
224 	zero = __refcount_dec_and_test(&call->ref, &r);
225 	o = atomic_read(&net->nr_outstanding_calls);
226 	trace_afs_call(debug_id, afs_call_trace_put, r - 1, o,
227 		       __builtin_return_address(0));
228 	if (zero)
229 		afs_free_call(call);
230 }
231 
afs_deferred_free_worker(struct work_struct * work)232 static void afs_deferred_free_worker(struct work_struct *work)
233 {
234 	struct afs_call *call = container_of(work, struct afs_call, free_work);
235 
236 	afs_free_call(call);
237 }
238 
239 /*
240  * Dispose of a reference on a call, deferring the cleanup to a workqueue
241  * to avoid lock recursion.
242  */
afs_deferred_put_call(struct afs_call * call)243 void afs_deferred_put_call(struct afs_call *call)
244 {
245 	struct afs_net *net = call->net;
246 	unsigned int debug_id = call->debug_id;
247 	bool zero;
248 	int r, o;
249 
250 	zero = __refcount_dec_and_test(&call->ref, &r);
251 	o = atomic_read(&net->nr_outstanding_calls);
252 	trace_afs_call(debug_id, afs_call_trace_put, r - 1, o,
253 		       __builtin_return_address(0));
254 	if (zero)
255 		schedule_work(&call->free_work);
256 }
257 
258 /*
259  * Queue the call for actual work.
260  */
afs_queue_call_work(struct afs_call * call)261 static void afs_queue_call_work(struct afs_call *call)
262 {
263 	if (call->type->work) {
264 		afs_get_call(call, afs_call_trace_work);
265 		if (!queue_work(afs_wq, &call->work))
266 			afs_put_call(call);
267 	}
268 }
269 
270 /*
271  * allocate a call with flat request and reply buffers
272  */
afs_alloc_flat_call(struct afs_net * net,const struct afs_call_type * type,size_t request_size,size_t reply_max)273 struct afs_call *afs_alloc_flat_call(struct afs_net *net,
274 				     const struct afs_call_type *type,
275 				     size_t request_size, size_t reply_max)
276 {
277 	struct afs_call *call;
278 
279 	call = afs_alloc_call(net, type, GFP_NOFS);
280 	if (!call)
281 		goto nomem_call;
282 
283 	if (request_size) {
284 		call->request_size = request_size;
285 		call->request = kmalloc(request_size, GFP_NOFS);
286 		if (!call->request)
287 			goto nomem_free;
288 	}
289 
290 	if (reply_max) {
291 		call->reply_max = reply_max;
292 		call->buffer = kmalloc(reply_max, GFP_NOFS);
293 		if (!call->buffer)
294 			goto nomem_free;
295 	}
296 
297 	afs_extract_to_buf(call, call->reply_max);
298 	call->operation_ID = type->op;
299 	init_waitqueue_head(&call->waitq);
300 	return call;
301 
302 nomem_free:
303 	afs_put_call(call);
304 nomem_call:
305 	return NULL;
306 }
307 
308 /*
309  * clean up a call with flat buffer
310  */
afs_flat_call_destructor(struct afs_call * call)311 void afs_flat_call_destructor(struct afs_call *call)
312 {
313 	_enter("");
314 
315 	kfree(call->request);
316 	call->request = NULL;
317 	kfree(call->buffer);
318 	call->buffer = NULL;
319 }
320 
321 /*
322  * Advance the AFS call state when the RxRPC call ends the transmit phase.
323  */
afs_notify_end_request_tx(struct sock * sock,struct rxrpc_call * rxcall,unsigned long call_user_ID)324 static void afs_notify_end_request_tx(struct sock *sock,
325 				      struct rxrpc_call *rxcall,
326 				      unsigned long call_user_ID)
327 {
328 	struct afs_call *call = (struct afs_call *)call_user_ID;
329 
330 	afs_set_call_state(call, AFS_CALL_CL_REQUESTING, AFS_CALL_CL_AWAIT_REPLY);
331 }
332 
333 /*
334  * Initiate a call and synchronously queue up the parameters for dispatch.  Any
335  * error is stored into the call struct, which the caller must check for.
336  */
afs_make_call(struct afs_call * call,gfp_t gfp)337 void afs_make_call(struct afs_call *call, gfp_t gfp)
338 {
339 	struct rxrpc_call *rxcall;
340 	struct msghdr msg;
341 	struct kvec iov[1];
342 	size_t len;
343 	s64 tx_total_len;
344 	int ret;
345 
346 	_enter(",{%pISp+%u},", rxrpc_kernel_remote_addr(call->peer), call->service_id);
347 
348 	ASSERT(call->type != NULL);
349 	ASSERT(call->type->name != NULL);
350 
351 	_debug("____MAKE %p{%s,%x} [%d]____",
352 	       call, call->type->name, key_serial(call->key),
353 	       atomic_read(&call->net->nr_outstanding_calls));
354 
355 	trace_afs_make_call(call);
356 
357 	/* Work out the length we're going to transmit.  This is awkward for
358 	 * calls such as FS.StoreData where there's an extra injection of data
359 	 * after the initial fixed part.
360 	 */
361 	tx_total_len = call->request_size;
362 	if (call->write_iter)
363 		tx_total_len += iov_iter_count(call->write_iter);
364 
365 	/* If the call is going to be asynchronous, we need an extra ref for
366 	 * the call to hold itself so the caller need not hang on to its ref.
367 	 */
368 	if (call->async) {
369 		afs_get_call(call, afs_call_trace_get);
370 		call->drop_ref = true;
371 	}
372 
373 	/* create a call */
374 	rxcall = rxrpc_kernel_begin_call(call->net->socket, call->peer, call->key,
375 					 (unsigned long)call,
376 					 tx_total_len,
377 					 call->max_lifespan,
378 					 gfp,
379 					 (call->async ?
380 					  afs_wake_up_async_call :
381 					  afs_wake_up_call_waiter),
382 					 call->service_id,
383 					 call->upgrade,
384 					 (call->intr ? RXRPC_PREINTERRUPTIBLE :
385 					  RXRPC_UNINTERRUPTIBLE),
386 					 call->debug_id);
387 	if (IS_ERR(rxcall)) {
388 		ret = PTR_ERR(rxcall);
389 		call->error = ret;
390 		goto error_kill_call;
391 	}
392 
393 	call->rxcall = rxcall;
394 	call->issue_time = ktime_get_real();
395 
396 	/* send the request */
397 	iov[0].iov_base	= call->request;
398 	iov[0].iov_len	= call->request_size;
399 
400 	msg.msg_name		= NULL;
401 	msg.msg_namelen		= 0;
402 	iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, iov, 1, call->request_size);
403 	msg.msg_control		= NULL;
404 	msg.msg_controllen	= 0;
405 	msg.msg_flags		= MSG_WAITALL | (call->write_iter ? MSG_MORE : 0);
406 
407 	ret = rxrpc_kernel_send_data(call->net->socket, rxcall,
408 				     &msg, call->request_size,
409 				     afs_notify_end_request_tx);
410 	if (ret < 0)
411 		goto error_do_abort;
412 
413 	if (call->write_iter) {
414 		msg.msg_iter = *call->write_iter;
415 		msg.msg_flags &= ~MSG_MORE;
416 		trace_afs_send_data(call, &msg);
417 
418 		ret = rxrpc_kernel_send_data(call->net->socket,
419 					     call->rxcall, &msg,
420 					     iov_iter_count(&msg.msg_iter),
421 					     afs_notify_end_request_tx);
422 		*call->write_iter = msg.msg_iter;
423 
424 		trace_afs_sent_data(call, &msg, ret);
425 		if (ret < 0)
426 			goto error_do_abort;
427 	}
428 
429 	/* Note that at this point, we may have received the reply or an abort
430 	 * - and an asynchronous call may already have completed.
431 	 *
432 	 * afs_wait_for_call_to_complete(call)
433 	 * must be called to synchronously clean up.
434 	 */
435 	return;
436 
437 error_do_abort:
438 	if (ret != -ECONNABORTED)
439 		rxrpc_kernel_abort_call(call->net->socket, rxcall,
440 					RX_USER_ABORT, ret,
441 					afs_abort_send_data_error);
442 	if (call->async) {
443 		afs_see_call(call, afs_call_trace_async_abort);
444 		return;
445 	}
446 
447 	if (ret == -ECONNABORTED) {
448 		len = 0;
449 		iov_iter_kvec(&msg.msg_iter, ITER_DEST, NULL, 0, 0);
450 		rxrpc_kernel_recv_data(call->net->socket, rxcall,
451 				       &msg.msg_iter, &len, false,
452 				       &call->abort_code, &call->service_id);
453 		call->responded = true;
454 	}
455 	call->error = ret;
456 	trace_afs_call_done(call);
457 error_kill_call:
458 	if (call->async)
459 		afs_see_call(call, afs_call_trace_async_kill);
460 	if (call->type->immediate_cancel)
461 		call->type->immediate_cancel(call);
462 
463 	/* We need to dispose of the extra ref we grabbed for an async call.
464 	 * The call, however, might be queued on afs_async_calls and we need to
465 	 * make sure we don't get any more notifications that might requeue it.
466 	 */
467 	if (call->rxcall)
468 		rxrpc_kernel_shutdown_call(call->net->socket, call->rxcall);
469 	if (call->async) {
470 		if (cancel_work_sync(&call->async_work))
471 			afs_put_call(call);
472 		afs_set_call_complete(call, ret, 0);
473 	}
474 
475 	call->error = ret;
476 	call->state = AFS_CALL_COMPLETE;
477 	_leave(" = %d", ret);
478 }
479 
480 /*
481  * Log remote abort codes that indicate that we have a protocol disagreement
482  * with the server.
483  */
afs_log_error(struct afs_call * call,s32 remote_abort)484 static void afs_log_error(struct afs_call *call, s32 remote_abort)
485 {
486 	static int max = 0;
487 	const char *msg;
488 	int m;
489 
490 	switch (remote_abort) {
491 	case RX_EOF:		 msg = "unexpected EOF";	break;
492 	case RXGEN_CC_MARSHAL:	 msg = "client marshalling";	break;
493 	case RXGEN_CC_UNMARSHAL: msg = "client unmarshalling";	break;
494 	case RXGEN_SS_MARSHAL:	 msg = "server marshalling";	break;
495 	case RXGEN_SS_UNMARSHAL: msg = "server unmarshalling";	break;
496 	case RXGEN_DECODE:	 msg = "opcode decode";		break;
497 	case RXGEN_SS_XDRFREE:	 msg = "server XDR cleanup";	break;
498 	case RXGEN_CC_XDRFREE:	 msg = "client XDR cleanup";	break;
499 	case -32:		 msg = "insufficient data";	break;
500 	default:
501 		return;
502 	}
503 
504 	m = max;
505 	if (m < 3) {
506 		max = m + 1;
507 		pr_notice("kAFS: Peer reported %s failure on %s [%pISp]\n",
508 			  msg, call->type->name,
509 			  rxrpc_kernel_remote_addr(call->peer));
510 	}
511 }
512 
513 /*
514  * deliver messages to a call
515  */
afs_deliver_to_call(struct afs_call * call)516 void afs_deliver_to_call(struct afs_call *call)
517 {
518 	enum afs_call_state state;
519 	size_t len;
520 	u32 abort_code, remote_abort = 0;
521 	int ret;
522 
523 	_enter("%s", call->type->name);
524 
525 	while (state = READ_ONCE(call->state),
526 	       state == AFS_CALL_CL_AWAIT_REPLY ||
527 	       state == AFS_CALL_SV_AWAIT_OP_ID ||
528 	       state == AFS_CALL_SV_AWAIT_REQUEST ||
529 	       state == AFS_CALL_SV_AWAIT_ACK
530 	       ) {
531 		if (state == AFS_CALL_SV_AWAIT_ACK) {
532 			len = 0;
533 			iov_iter_kvec(&call->def_iter, ITER_DEST, NULL, 0, 0);
534 			ret = rxrpc_kernel_recv_data(call->net->socket,
535 						     call->rxcall, &call->def_iter,
536 						     &len, false, &remote_abort,
537 						     &call->service_id);
538 			trace_afs_receive_data(call, &call->def_iter, false, ret);
539 
540 			if (ret == -EINPROGRESS || ret == -EAGAIN)
541 				return;
542 			if (ret < 0 || ret == 1) {
543 				if (ret == 1)
544 					ret = 0;
545 				goto call_complete;
546 			}
547 			return;
548 		}
549 
550 		ret = call->type->deliver(call);
551 		state = READ_ONCE(call->state);
552 		if (ret == 0 && call->unmarshalling_error)
553 			ret = -EBADMSG;
554 		switch (ret) {
555 		case 0:
556 			call->responded = true;
557 			afs_queue_call_work(call);
558 			if (state == AFS_CALL_CL_PROC_REPLY) {
559 				if (call->op)
560 					set_bit(AFS_SERVER_FL_MAY_HAVE_CB,
561 						&call->op->server->flags);
562 				goto call_complete;
563 			}
564 			ASSERTCMP(state, >, AFS_CALL_CL_PROC_REPLY);
565 			goto done;
566 		case -EINPROGRESS:
567 		case -EAGAIN:
568 			goto out;
569 		case -ECONNABORTED:
570 			ASSERTCMP(state, ==, AFS_CALL_COMPLETE);
571 			call->responded = true;
572 			afs_log_error(call, call->abort_code);
573 			goto done;
574 		case -ENOTSUPP:
575 			call->responded = true;
576 			abort_code = RXGEN_OPCODE;
577 			rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
578 						abort_code, ret,
579 						afs_abort_op_not_supported);
580 			goto local_abort;
581 		case -EIO:
582 			pr_err("kAFS: Call %u in bad state %u\n",
583 			       call->debug_id, state);
584 			fallthrough;
585 		case -ENODATA:
586 		case -EBADMSG:
587 		case -EMSGSIZE:
588 		case -ENOMEM:
589 		case -EFAULT:
590 			abort_code = RXGEN_CC_UNMARSHAL;
591 			if (state != AFS_CALL_CL_AWAIT_REPLY)
592 				abort_code = RXGEN_SS_UNMARSHAL;
593 			rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
594 						abort_code, ret,
595 						afs_abort_unmarshal_error);
596 			goto local_abort;
597 		default:
598 			abort_code = RX_CALL_DEAD;
599 			rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
600 						abort_code, ret,
601 						afs_abort_general_error);
602 			goto local_abort;
603 		}
604 	}
605 
606 done:
607 	if (call->type->done)
608 		call->type->done(call);
609 out:
610 	_leave("");
611 	return;
612 
613 local_abort:
614 	abort_code = 0;
615 call_complete:
616 	afs_set_call_complete(call, ret, remote_abort);
617 	goto done;
618 }
619 
620 /*
621  * Wait synchronously for a call to complete.
622  */
afs_wait_for_call_to_complete(struct afs_call * call)623 void afs_wait_for_call_to_complete(struct afs_call *call)
624 {
625 	bool rxrpc_complete = false;
626 
627 	_enter("");
628 
629 	if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {
630 		DECLARE_WAITQUEUE(myself, current);
631 
632 		add_wait_queue(&call->waitq, &myself);
633 		for (;;) {
634 			set_current_state(TASK_UNINTERRUPTIBLE);
635 
636 			/* deliver any messages that are in the queue */
637 			if (!afs_check_call_state(call, AFS_CALL_COMPLETE) &&
638 			    call->need_attention) {
639 				call->need_attention = false;
640 				__set_current_state(TASK_RUNNING);
641 				afs_deliver_to_call(call);
642 				continue;
643 			}
644 
645 			if (afs_check_call_state(call, AFS_CALL_COMPLETE))
646 				break;
647 
648 			if (!rxrpc_kernel_check_life(call->net->socket, call->rxcall)) {
649 				/* rxrpc terminated the call. */
650 				rxrpc_complete = true;
651 				break;
652 			}
653 
654 			schedule();
655 		}
656 
657 		remove_wait_queue(&call->waitq, &myself);
658 		__set_current_state(TASK_RUNNING);
659 	}
660 
661 	if (!afs_check_call_state(call, AFS_CALL_COMPLETE)) {
662 		if (rxrpc_complete) {
663 			afs_set_call_complete(call, call->error, call->abort_code);
664 		} else {
665 			/* Kill off the call if it's still live. */
666 			_debug("call interrupted");
667 			if (rxrpc_kernel_abort_call(call->net->socket, call->rxcall,
668 						    RX_USER_ABORT, -EINTR,
669 						    afs_abort_interrupted))
670 				afs_set_call_complete(call, -EINTR, 0);
671 		}
672 	}
673 }
674 
675 /*
676  * wake up a waiting call
677  */
afs_wake_up_call_waiter(struct sock * sk,struct rxrpc_call * rxcall,unsigned long call_user_ID)678 static void afs_wake_up_call_waiter(struct sock *sk, struct rxrpc_call *rxcall,
679 				    unsigned long call_user_ID)
680 {
681 	struct afs_call *call = (struct afs_call *)call_user_ID;
682 
683 	call->need_attention = true;
684 	wake_up(&call->waitq);
685 }
686 
687 /*
688  * Wake up an asynchronous call.  The caller is holding the call notify
689  * spinlock around this, so we can't call afs_put_call().
690  */
afs_wake_up_async_call(struct sock * sk,struct rxrpc_call * rxcall,unsigned long call_user_ID)691 static void afs_wake_up_async_call(struct sock *sk, struct rxrpc_call *rxcall,
692 				   unsigned long call_user_ID)
693 {
694 	struct afs_call *call = (struct afs_call *)call_user_ID;
695 	int r;
696 
697 	trace_afs_notify_call(rxcall, call);
698 	call->need_attention = true;
699 
700 	if (__refcount_inc_not_zero(&call->ref, &r)) {
701 		trace_afs_call(call->debug_id, afs_call_trace_wake, r + 1,
702 			       atomic_read(&call->net->nr_outstanding_calls),
703 			       __builtin_return_address(0));
704 
705 		if (!queue_work(afs_async_calls, &call->async_work))
706 			afs_deferred_put_call(call);
707 	}
708 }
709 
710 /*
711  * Perform I/O processing on an asynchronous call.  The work item carries a ref
712  * to the call struct that we either need to release or to pass on.
713  */
afs_process_async_call(struct work_struct * work)714 static void afs_process_async_call(struct work_struct *work)
715 {
716 	struct afs_call *call = container_of(work, struct afs_call, async_work);
717 
718 	_enter("");
719 
720 	if (call->state < AFS_CALL_COMPLETE && call->need_attention) {
721 		call->need_attention = false;
722 		afs_deliver_to_call(call);
723 	}
724 
725 	afs_put_call(call);
726 	_leave("");
727 }
728 
afs_rx_attach(struct rxrpc_call * rxcall,unsigned long user_call_ID)729 static void afs_rx_attach(struct rxrpc_call *rxcall, unsigned long user_call_ID)
730 {
731 	struct afs_call *call = (struct afs_call *)user_call_ID;
732 
733 	call->rxcall = rxcall;
734 }
735 
736 /*
737  * Charge the incoming call preallocation.
738  */
afs_charge_preallocation(struct work_struct * work)739 void afs_charge_preallocation(struct work_struct *work)
740 {
741 	struct afs_net *net =
742 		container_of(work, struct afs_net, charge_preallocation_work);
743 	struct afs_call *call = net->spare_incoming_call;
744 
745 	for (;;) {
746 		if (!call) {
747 			call = afs_alloc_call(net, &afs_RXCMxxxx, GFP_KERNEL);
748 			if (!call)
749 				break;
750 
751 			call->drop_ref = true;
752 			call->async = true;
753 			call->state = AFS_CALL_SV_AWAIT_OP_ID;
754 			init_waitqueue_head(&call->waitq);
755 			afs_extract_to_tmp(call);
756 		}
757 
758 		if (rxrpc_kernel_charge_accept(net->socket,
759 					       afs_wake_up_async_call,
760 					       (unsigned long)call,
761 					       GFP_KERNEL,
762 					       call->debug_id) < 0)
763 			break;
764 		call = NULL;
765 	}
766 	net->spare_incoming_call = call;
767 }
768 
769 /*
770  * Discard a preallocated call when a socket is shut down.
771  */
afs_rx_discard_new_call(struct rxrpc_call * rxcall,unsigned long user_call_ID)772 static void afs_rx_discard_new_call(struct rxrpc_call *rxcall,
773 				    unsigned long user_call_ID)
774 {
775 	struct afs_call *call = (struct afs_call *)user_call_ID;
776 
777 	call->rxcall = NULL;
778 	afs_put_call(call);
779 }
780 
781 /*
782  * Notification of an incoming call.
783  */
afs_rx_new_call(struct sock * sk,struct rxrpc_call * rxcall,unsigned long user_call_ID)784 static void afs_rx_new_call(struct sock *sk, struct rxrpc_call *rxcall,
785 			    unsigned long user_call_ID)
786 {
787 	struct afs_call *call = (struct afs_call *)user_call_ID;
788 	struct afs_net *net = afs_sock2net(sk);
789 
790 	call->peer = rxrpc_kernel_get_call_peer(sk->sk_socket, call->rxcall);
791 	call->server = afs_find_server(call->peer);
792 	if (!call->server)
793 		trace_afs_cm_no_server(call, rxrpc_kernel_remote_srx(call->peer));
794 
795 	queue_work(afs_wq, &net->charge_preallocation_work);
796 }
797 
798 /*
799  * Grab the operation ID from an incoming cache manager call.  The socket
800  * buffer is discarded on error or if we don't yet have sufficient data.
801  */
afs_deliver_cm_op_id(struct afs_call * call)802 static int afs_deliver_cm_op_id(struct afs_call *call)
803 {
804 	int ret;
805 
806 	_enter("{%zu}", iov_iter_count(call->iter));
807 
808 	/* the operation ID forms the first four bytes of the request data */
809 	ret = afs_extract_data(call, true);
810 	if (ret < 0)
811 		return ret;
812 
813 	call->operation_ID = ntohl(call->tmp);
814 	afs_set_call_state(call, AFS_CALL_SV_AWAIT_OP_ID, AFS_CALL_SV_AWAIT_REQUEST);
815 
816 	/* ask the cache manager to route the call (it'll change the call type
817 	 * if successful) */
818 	if (!afs_cm_incoming_call(call))
819 		return -ENOTSUPP;
820 
821 	call->security_ix = rxrpc_kernel_query_call_security(call->rxcall,
822 							     &call->service_id,
823 							     &call->enctype);
824 
825 	trace_afs_cb_call(call);
826 	call->work.func = call->type->work;
827 
828 	/* pass responsibility for the remainder 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, ITER_SOURCE, 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 					RXGEN_SS_MARSHAL, -ENOMEM,
875 					afs_abort_oom);
876 		fallthrough;
877 	default:
878 		_leave(" [error]");
879 		return;
880 	}
881 }
882 
883 /*
884  * send a simple reply
885  */
afs_send_simple_reply(struct afs_call * call,const void * buf,size_t len)886 void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len)
887 {
888 	struct afs_net *net = call->net;
889 	struct msghdr msg;
890 	struct kvec iov[1];
891 	int n;
892 
893 	_enter("");
894 
895 	rxrpc_kernel_set_tx_length(net->socket, call->rxcall, len);
896 
897 	iov[0].iov_base		= (void *) buf;
898 	iov[0].iov_len		= len;
899 	msg.msg_name		= NULL;
900 	msg.msg_namelen		= 0;
901 	iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, iov, 1, len);
902 	msg.msg_control		= NULL;
903 	msg.msg_controllen	= 0;
904 	msg.msg_flags		= 0;
905 
906 	n = rxrpc_kernel_send_data(net->socket, call->rxcall, &msg, len,
907 				   afs_notify_end_reply_tx);
908 	if (n >= 0) {
909 		/* Success */
910 		_leave(" [replied]");
911 		return;
912 	}
913 
914 	if (n == -ENOMEM) {
915 		_debug("oom");
916 		rxrpc_kernel_abort_call(net->socket, call->rxcall,
917 					RXGEN_SS_MARSHAL, -ENOMEM,
918 					afs_abort_oom);
919 	}
920 	_leave(" [error]");
921 }
922 
923 /*
924  * Extract a piece of data from the received data socket buffers.
925  */
afs_extract_data(struct afs_call * call,bool want_more)926 int afs_extract_data(struct afs_call *call, bool want_more)
927 {
928 	struct afs_net *net = call->net;
929 	struct iov_iter *iter = call->iter;
930 	enum afs_call_state state;
931 	u32 remote_abort = 0;
932 	int ret;
933 
934 	_enter("{%s,%zu,%zu},%d",
935 	       call->type->name, call->iov_len, iov_iter_count(iter), want_more);
936 
937 	ret = rxrpc_kernel_recv_data(net->socket, call->rxcall, iter,
938 				     &call->iov_len, want_more, &remote_abort,
939 				     &call->service_id);
940 	trace_afs_receive_data(call, call->iter, want_more, ret);
941 	if (ret == 0 || ret == -EAGAIN)
942 		return ret;
943 
944 	state = READ_ONCE(call->state);
945 	if (ret == 1) {
946 		switch (state) {
947 		case AFS_CALL_CL_AWAIT_REPLY:
948 			afs_set_call_state(call, state, AFS_CALL_CL_PROC_REPLY);
949 			break;
950 		case AFS_CALL_SV_AWAIT_REQUEST:
951 			afs_set_call_state(call, state, AFS_CALL_SV_REPLYING);
952 			break;
953 		case AFS_CALL_COMPLETE:
954 			kdebug("prem complete %d", call->error);
955 			return afs_io_error(call, afs_io_error_extract);
956 		default:
957 			break;
958 		}
959 		return 0;
960 	}
961 
962 	afs_set_call_complete(call, ret, remote_abort);
963 	return ret;
964 }
965 
966 /*
967  * Log protocol error production.
968  */
afs_protocol_error(struct afs_call * call,enum afs_eproto_cause cause)969 noinline int afs_protocol_error(struct afs_call *call,
970 				enum afs_eproto_cause cause)
971 {
972 	trace_afs_protocol_error(call, cause);
973 	if (call)
974 		call->unmarshalling_error = true;
975 	return -EBADMSG;
976 }
977 
978 /*
979  * Wake up OOB notification processing.
980  */
afs_rx_notify_oob(struct sock * sk,struct sk_buff * oob)981 static void afs_rx_notify_oob(struct sock *sk, struct sk_buff *oob)
982 {
983 	struct afs_net *net = sk->sk_user_data;
984 
985 	schedule_work(&net->rx_oob_work);
986 }
987