xref: /linux/net/rxrpc/sendmsg.c (revision b4db9f840283caca0d904436f187ef56a9126eaa)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* AF_RXRPC sendmsg() implementation.
3  *
4  * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
5  * Written by David Howells (dhowells@redhat.com)
6  */
7 
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9 
10 #include <linux/net.h>
11 #include <linux/gfp.h>
12 #include <linux/skbuff.h>
13 #include <linux/export.h>
14 #include <linux/sched/signal.h>
15 
16 #include <net/sock.h>
17 #include <net/af_rxrpc.h>
18 #include "ar-internal.h"
19 
20 /*
21  * Propose an abort to be made in the I/O thread.
22  */
23 bool rxrpc_propose_abort(struct rxrpc_call *call, s32 abort_code, int error,
24 			 enum rxrpc_abort_reason why)
25 {
26 	_enter("{%d},%d,%d,%u", call->debug_id, abort_code, error, why);
27 
28 	if (!call->send_abort && !rxrpc_call_is_complete(call)) {
29 		call->send_abort_why = why;
30 		call->send_abort_err = error;
31 		call->send_abort_seq = 0;
32 		/* Request abort locklessly vs rxrpc_input_call_event(). */
33 		smp_store_release(&call->send_abort, abort_code);
34 		rxrpc_poke_call(call, rxrpc_call_poke_abort);
35 		return true;
36 	}
37 
38 	return false;
39 }
40 
41 /*
42  * Wait for a call to become connected.  Interruption here doesn't cause the
43  * call to be aborted.
44  */
45 static int rxrpc_wait_to_be_connected(struct rxrpc_call *call, long *timeo)
46 {
47 	DECLARE_WAITQUEUE(myself, current);
48 	int ret = 0;
49 
50 	_enter("%d", call->debug_id);
51 
52 	if (rxrpc_call_state(call) != RXRPC_CALL_CLIENT_AWAIT_CONN)
53 		goto no_wait;
54 
55 	add_wait_queue_exclusive(&call->waitq, &myself);
56 
57 	for (;;) {
58 		switch (call->interruptibility) {
59 		case RXRPC_INTERRUPTIBLE:
60 		case RXRPC_PREINTERRUPTIBLE:
61 			set_current_state(TASK_INTERRUPTIBLE);
62 			break;
63 		case RXRPC_UNINTERRUPTIBLE:
64 		default:
65 			set_current_state(TASK_UNINTERRUPTIBLE);
66 			break;
67 		}
68 
69 		if (rxrpc_call_state(call) != RXRPC_CALL_CLIENT_AWAIT_CONN)
70 			break;
71 		if ((call->interruptibility == RXRPC_INTERRUPTIBLE ||
72 		     call->interruptibility == RXRPC_PREINTERRUPTIBLE) &&
73 		    signal_pending(current)) {
74 			ret = sock_intr_errno(*timeo);
75 			break;
76 		}
77 		*timeo = schedule_timeout(*timeo);
78 	}
79 
80 	remove_wait_queue(&call->waitq, &myself);
81 	__set_current_state(TASK_RUNNING);
82 
83 no_wait:
84 	if (ret == 0 && rxrpc_call_is_complete(call))
85 		ret = call->error;
86 
87 	_leave(" = %d", ret);
88 	return ret;
89 }
90 
91 /*
92  * Return true if there's sufficient Tx queue space.
93  */
94 static bool rxrpc_check_tx_space(struct rxrpc_call *call, rxrpc_seq_t *_tx_win)
95 {
96 	if (_tx_win)
97 		*_tx_win = call->tx_bottom;
98 	return call->tx_prepared - call->tx_bottom < 256;
99 }
100 
101 /*
102  * Wait for space to appear in the Tx queue or a signal to occur.
103  */
104 static int rxrpc_wait_for_tx_window_intr(struct rxrpc_sock *rx,
105 					 struct rxrpc_call *call,
106 					 long *timeo)
107 {
108 	for (;;) {
109 		set_current_state(TASK_INTERRUPTIBLE);
110 		if (rxrpc_check_tx_space(call, NULL))
111 			return 0;
112 
113 		if (rxrpc_call_is_complete(call))
114 			return call->error;
115 
116 		if (signal_pending(current))
117 			return sock_intr_errno(*timeo);
118 
119 		trace_rxrpc_txqueue(call, rxrpc_txqueue_wait);
120 		*timeo = schedule_timeout(*timeo);
121 	}
122 }
123 
124 /*
125  * Wait for space to appear in the Tx queue uninterruptibly, but with
126  * a timeout of 2*RTT if no progress was made and a signal occurred.
127  */
128 static int rxrpc_wait_for_tx_window_waitall(struct rxrpc_sock *rx,
129 					    struct rxrpc_call *call)
130 {
131 	rxrpc_seq_t tx_start, tx_win;
132 	signed long rtt, timeout;
133 
134 	rtt = READ_ONCE(call->peer->srtt_us) >> 3;
135 	rtt = usecs_to_jiffies(rtt) * 2;
136 	if (rtt < 2)
137 		rtt = 2;
138 
139 	timeout = rtt;
140 	tx_start = smp_load_acquire(&call->acks_hard_ack);
141 
142 	for (;;) {
143 		set_current_state(TASK_UNINTERRUPTIBLE);
144 
145 		if (rxrpc_check_tx_space(call, &tx_win))
146 			return 0;
147 
148 		if (rxrpc_call_is_complete(call))
149 			return call->error;
150 
151 		if (timeout == 0 &&
152 		    tx_win == tx_start && signal_pending(current))
153 			return -EINTR;
154 
155 		if (tx_win != tx_start) {
156 			timeout = rtt;
157 			tx_start = tx_win;
158 		}
159 
160 		trace_rxrpc_txqueue(call, rxrpc_txqueue_wait);
161 		timeout = schedule_timeout(timeout);
162 	}
163 }
164 
165 /*
166  * Wait for space to appear in the Tx queue uninterruptibly.
167  */
168 static int rxrpc_wait_for_tx_window_nonintr(struct rxrpc_sock *rx,
169 					    struct rxrpc_call *call,
170 					    long *timeo)
171 {
172 	for (;;) {
173 		set_current_state(TASK_UNINTERRUPTIBLE);
174 		if (rxrpc_check_tx_space(call, NULL))
175 			return 0;
176 
177 		if (rxrpc_call_is_complete(call))
178 			return call->error;
179 
180 		trace_rxrpc_txqueue(call, rxrpc_txqueue_wait);
181 		*timeo = schedule_timeout(*timeo);
182 	}
183 }
184 
185 /*
186  * wait for space to appear in the transmit/ACK window
187  * - caller holds the socket locked
188  */
189 static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
190 				    struct rxrpc_call *call,
191 				    long *timeo,
192 				    bool waitall)
193 {
194 	DECLARE_WAITQUEUE(myself, current);
195 	int ret;
196 
197 	_enter(",{%u,%u,%u,%u}",
198 	       call->tx_bottom, call->acks_hard_ack, call->tx_top, call->tx_winsize);
199 
200 	add_wait_queue(&call->waitq, &myself);
201 
202 	switch (call->interruptibility) {
203 	case RXRPC_INTERRUPTIBLE:
204 		if (waitall)
205 			ret = rxrpc_wait_for_tx_window_waitall(rx, call);
206 		else
207 			ret = rxrpc_wait_for_tx_window_intr(rx, call, timeo);
208 		break;
209 	case RXRPC_PREINTERRUPTIBLE:
210 	case RXRPC_UNINTERRUPTIBLE:
211 	default:
212 		ret = rxrpc_wait_for_tx_window_nonintr(rx, call, timeo);
213 		break;
214 	}
215 
216 	remove_wait_queue(&call->waitq, &myself);
217 	set_current_state(TASK_RUNNING);
218 	_leave(" = %d", ret);
219 	return ret;
220 }
221 
222 /*
223  * Notify the owner of the call that the transmit phase is ended and the last
224  * packet has been queued.
225  */
226 static void rxrpc_notify_end_tx(struct rxrpc_sock *rx, struct rxrpc_call *call,
227 				rxrpc_notify_end_tx_t notify_end_tx)
228 {
229 	if (notify_end_tx)
230 		notify_end_tx(&rx->sk, call, call->user_call_ID);
231 }
232 
233 /*
234  * Queue a DATA packet for transmission, set the resend timeout and send
235  * the packet immediately.  Returns the error from rxrpc_send_data_packet()
236  * in case the caller wants to do something with it.
237  */
238 static void rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
239 			       struct rxrpc_txbuf *txb,
240 			       rxrpc_notify_end_tx_t notify_end_tx)
241 {
242 	rxrpc_seq_t seq = txb->seq;
243 	bool poke, last = txb->flags & RXRPC_LAST_PACKET;
244 
245 	rxrpc_inc_stat(call->rxnet, stat_tx_data);
246 
247 	ASSERTCMP(txb->seq, ==, call->tx_prepared + 1);
248 
249 	/* We have to set the timestamp before queueing as the retransmit
250 	 * algorithm can see the packet as soon as we queue it.
251 	 */
252 	txb->last_sent = ktime_get_real();
253 
254 	if (last)
255 		trace_rxrpc_txqueue(call, rxrpc_txqueue_queue_last);
256 	else
257 		trace_rxrpc_txqueue(call, rxrpc_txqueue_queue);
258 
259 	/* Add the packet to the call's output buffer */
260 	spin_lock(&call->tx_lock);
261 	poke = list_empty(&call->tx_sendmsg);
262 	list_add_tail(&txb->call_link, &call->tx_sendmsg);
263 	call->tx_prepared = seq;
264 	if (last)
265 		rxrpc_notify_end_tx(rx, call, notify_end_tx);
266 	spin_unlock(&call->tx_lock);
267 
268 	if (poke)
269 		rxrpc_poke_call(call, rxrpc_call_poke_start);
270 }
271 
272 /*
273  * send data through a socket
274  * - must be called in process context
275  * - The caller holds the call user access mutex, but not the socket lock.
276  */
277 static int rxrpc_send_data(struct rxrpc_sock *rx,
278 			   struct rxrpc_call *call,
279 			   struct msghdr *msg, size_t len,
280 			   rxrpc_notify_end_tx_t notify_end_tx,
281 			   bool *_dropped_lock)
282 {
283 	struct rxrpc_txbuf *txb;
284 	struct sock *sk = &rx->sk;
285 	enum rxrpc_call_state state;
286 	long timeo;
287 	bool more = msg->msg_flags & MSG_MORE;
288 	int ret, copied = 0;
289 
290 	timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
291 
292 	ret = rxrpc_wait_to_be_connected(call, &timeo);
293 	if (ret < 0)
294 		return ret;
295 
296 	if (call->conn->state == RXRPC_CONN_CLIENT_UNSECURED) {
297 		ret = rxrpc_init_client_conn_security(call->conn);
298 		if (ret < 0)
299 			return ret;
300 	}
301 
302 	/* this should be in poll */
303 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
304 
305 reload:
306 	ret = -EPIPE;
307 	if (sk->sk_shutdown & SEND_SHUTDOWN)
308 		goto maybe_error;
309 	state = rxrpc_call_state(call);
310 	ret = -ESHUTDOWN;
311 	if (state >= RXRPC_CALL_COMPLETE)
312 		goto maybe_error;
313 	ret = -EPROTO;
314 	if (state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
315 	    state != RXRPC_CALL_SERVER_ACK_REQUEST &&
316 	    state != RXRPC_CALL_SERVER_SEND_REPLY) {
317 		/* Request phase complete for this client call */
318 		trace_rxrpc_abort(call->debug_id, rxrpc_sendmsg_late_send,
319 				  call->cid, call->call_id, call->rx_consumed,
320 				  0, -EPROTO);
321 		goto maybe_error;
322 	}
323 
324 	ret = -EMSGSIZE;
325 	if (call->tx_total_len != -1) {
326 		if (len - copied > call->tx_total_len)
327 			goto maybe_error;
328 		if (!more && len - copied != call->tx_total_len)
329 			goto maybe_error;
330 	}
331 
332 	txb = call->tx_pending;
333 	call->tx_pending = NULL;
334 	if (txb)
335 		rxrpc_see_txbuf(txb, rxrpc_txbuf_see_send_more);
336 
337 	do {
338 		if (!txb) {
339 			size_t remain;
340 
341 			_debug("alloc");
342 
343 			if (!rxrpc_check_tx_space(call, NULL))
344 				goto wait_for_space;
345 
346 			/* Work out the maximum size of a packet.  Assume that
347 			 * the security header is going to be in the padded
348 			 * region (enc blocksize), but the trailer is not.
349 			 */
350 			remain = more ? INT_MAX : msg_data_left(msg);
351 			txb = call->conn->security->alloc_txbuf(call, remain, sk->sk_allocation);
352 			if (!txb) {
353 				ret = -ENOMEM;
354 				goto maybe_error;
355 			}
356 		}
357 
358 		_debug("append");
359 
360 		/* append next segment of data to the current buffer */
361 		if (msg_data_left(msg) > 0) {
362 			size_t copy = min_t(size_t, txb->space, msg_data_left(msg));
363 
364 			_debug("add %zu", copy);
365 			if (!copy_from_iter_full(txb->kvec[0].iov_base + txb->offset,
366 						 copy, &msg->msg_iter))
367 				goto efault;
368 			_debug("added");
369 			txb->space -= copy;
370 			txb->len += copy;
371 			txb->offset += copy;
372 			copied += copy;
373 			if (call->tx_total_len != -1)
374 				call->tx_total_len -= copy;
375 		}
376 
377 		/* check for the far side aborting the call or a network error
378 		 * occurring */
379 		if (rxrpc_call_is_complete(call))
380 			goto call_terminated;
381 
382 		/* add the packet to the send queue if it's now full */
383 		if (!txb->space ||
384 		    (msg_data_left(msg) == 0 && !more)) {
385 			if (msg_data_left(msg) == 0 && !more)
386 				txb->flags |= RXRPC_LAST_PACKET;
387 			else if (call->tx_top - call->acks_hard_ack <
388 				 call->tx_winsize)
389 				txb->flags |= RXRPC_MORE_PACKETS;
390 
391 			ret = call->security->secure_packet(call, txb);
392 			if (ret < 0)
393 				goto out;
394 
395 			txb->kvec[0].iov_len += txb->len;
396 			txb->len = txb->kvec[0].iov_len;
397 			rxrpc_queue_packet(rx, call, txb, notify_end_tx);
398 			txb = NULL;
399 		}
400 	} while (msg_data_left(msg) > 0);
401 
402 success:
403 	ret = copied;
404 	if (rxrpc_call_is_complete(call) &&
405 	    call->error < 0)
406 		ret = call->error;
407 out:
408 	call->tx_pending = txb;
409 	_leave(" = %d", ret);
410 	return ret;
411 
412 call_terminated:
413 	rxrpc_put_txbuf(txb, rxrpc_txbuf_put_send_aborted);
414 	_leave(" = %d", call->error);
415 	return call->error;
416 
417 maybe_error:
418 	if (copied)
419 		goto success;
420 	goto out;
421 
422 efault:
423 	ret = -EFAULT;
424 	goto out;
425 
426 wait_for_space:
427 	ret = -EAGAIN;
428 	if (msg->msg_flags & MSG_DONTWAIT)
429 		goto maybe_error;
430 	mutex_unlock(&call->user_mutex);
431 	*_dropped_lock = true;
432 	ret = rxrpc_wait_for_tx_window(rx, call, &timeo,
433 				       msg->msg_flags & MSG_WAITALL);
434 	if (ret < 0)
435 		goto maybe_error;
436 	if (call->interruptibility == RXRPC_INTERRUPTIBLE) {
437 		if (mutex_lock_interruptible(&call->user_mutex) < 0) {
438 			ret = sock_intr_errno(timeo);
439 			goto maybe_error;
440 		}
441 	} else {
442 		mutex_lock(&call->user_mutex);
443 	}
444 	*_dropped_lock = false;
445 	goto reload;
446 }
447 
448 /*
449  * extract control messages from the sendmsg() control buffer
450  */
451 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
452 {
453 	struct cmsghdr *cmsg;
454 	bool got_user_ID = false;
455 	int len;
456 
457 	if (msg->msg_controllen == 0)
458 		return -EINVAL;
459 
460 	for_each_cmsghdr(cmsg, msg) {
461 		if (!CMSG_OK(msg, cmsg))
462 			return -EINVAL;
463 
464 		len = cmsg->cmsg_len - sizeof(struct cmsghdr);
465 		_debug("CMSG %d, %d, %d",
466 		       cmsg->cmsg_level, cmsg->cmsg_type, len);
467 
468 		if (cmsg->cmsg_level != SOL_RXRPC)
469 			continue;
470 
471 		switch (cmsg->cmsg_type) {
472 		case RXRPC_USER_CALL_ID:
473 			if (msg->msg_flags & MSG_CMSG_COMPAT) {
474 				if (len != sizeof(u32))
475 					return -EINVAL;
476 				p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
477 			} else {
478 				if (len != sizeof(unsigned long))
479 					return -EINVAL;
480 				p->call.user_call_ID = *(unsigned long *)
481 					CMSG_DATA(cmsg);
482 			}
483 			got_user_ID = true;
484 			break;
485 
486 		case RXRPC_ABORT:
487 			if (p->command != RXRPC_CMD_SEND_DATA)
488 				return -EINVAL;
489 			p->command = RXRPC_CMD_SEND_ABORT;
490 			if (len != sizeof(p->abort_code))
491 				return -EINVAL;
492 			p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
493 			if (p->abort_code == 0)
494 				return -EINVAL;
495 			break;
496 
497 		case RXRPC_CHARGE_ACCEPT:
498 			if (p->command != RXRPC_CMD_SEND_DATA)
499 				return -EINVAL;
500 			p->command = RXRPC_CMD_CHARGE_ACCEPT;
501 			if (len != 0)
502 				return -EINVAL;
503 			break;
504 
505 		case RXRPC_EXCLUSIVE_CALL:
506 			p->exclusive = true;
507 			if (len != 0)
508 				return -EINVAL;
509 			break;
510 
511 		case RXRPC_UPGRADE_SERVICE:
512 			p->upgrade = true;
513 			if (len != 0)
514 				return -EINVAL;
515 			break;
516 
517 		case RXRPC_TX_LENGTH:
518 			if (p->call.tx_total_len != -1 || len != sizeof(__s64))
519 				return -EINVAL;
520 			p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
521 			if (p->call.tx_total_len < 0)
522 				return -EINVAL;
523 			break;
524 
525 		case RXRPC_SET_CALL_TIMEOUT:
526 			if (len & 3 || len < 4 || len > 12)
527 				return -EINVAL;
528 			memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
529 			p->call.nr_timeouts = len / 4;
530 			if (p->call.timeouts.hard > INT_MAX / HZ)
531 				return -ERANGE;
532 			if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
533 				return -ERANGE;
534 			if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
535 				return -ERANGE;
536 			break;
537 
538 		default:
539 			return -EINVAL;
540 		}
541 	}
542 
543 	if (!got_user_ID)
544 		return -EINVAL;
545 	if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
546 		return -EINVAL;
547 	_leave(" = 0");
548 	return 0;
549 }
550 
551 /*
552  * Create a new client call for sendmsg().
553  * - Called with the socket lock held, which it must release.
554  * - If it returns a call, the call's lock will need releasing by the caller.
555  */
556 static struct rxrpc_call *
557 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
558 				  struct rxrpc_send_params *p)
559 	__releases(&rx->sk.sk_lock.slock)
560 	__acquires(&call->user_mutex)
561 {
562 	struct rxrpc_conn_parameters cp;
563 	struct rxrpc_peer *peer;
564 	struct rxrpc_call *call;
565 	struct key *key;
566 
567 	DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
568 
569 	_enter("");
570 
571 	if (!msg->msg_name) {
572 		release_sock(&rx->sk);
573 		return ERR_PTR(-EDESTADDRREQ);
574 	}
575 
576 	peer = rxrpc_lookup_peer(rx->local, srx, GFP_KERNEL);
577 	if (!peer) {
578 		release_sock(&rx->sk);
579 		return ERR_PTR(-ENOMEM);
580 	}
581 
582 	key = rx->key;
583 	if (key && !rx->key->payload.data[0])
584 		key = NULL;
585 
586 	memset(&cp, 0, sizeof(cp));
587 	cp.local		= rx->local;
588 	cp.peer			= peer;
589 	cp.key			= rx->key;
590 	cp.security_level	= rx->min_sec_level;
591 	cp.exclusive		= rx->exclusive | p->exclusive;
592 	cp.upgrade		= p->upgrade;
593 	cp.service_id		= srx->srx_service;
594 	call = rxrpc_new_client_call(rx, &cp, &p->call, GFP_KERNEL,
595 				     atomic_inc_return(&rxrpc_debug_id));
596 	/* The socket is now unlocked */
597 
598 	rxrpc_put_peer(peer, rxrpc_peer_put_application);
599 	_leave(" = %p\n", call);
600 	return call;
601 }
602 
603 /*
604  * send a message forming part of a client call through an RxRPC socket
605  * - caller holds the socket locked
606  * - the socket may be either a client socket or a server socket
607  */
608 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
609 	__releases(&rx->sk.sk_lock.slock)
610 {
611 	struct rxrpc_call *call;
612 	bool dropped_lock = false;
613 	int ret;
614 
615 	struct rxrpc_send_params p = {
616 		.call.tx_total_len	= -1,
617 		.call.user_call_ID	= 0,
618 		.call.nr_timeouts	= 0,
619 		.call.interruptibility	= RXRPC_INTERRUPTIBLE,
620 		.abort_code		= 0,
621 		.command		= RXRPC_CMD_SEND_DATA,
622 		.exclusive		= false,
623 		.upgrade		= false,
624 	};
625 
626 	_enter("");
627 
628 	ret = rxrpc_sendmsg_cmsg(msg, &p);
629 	if (ret < 0)
630 		goto error_release_sock;
631 
632 	if (p.command == RXRPC_CMD_CHARGE_ACCEPT) {
633 		ret = -EINVAL;
634 		if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
635 			goto error_release_sock;
636 		ret = rxrpc_user_charge_accept(rx, p.call.user_call_ID);
637 		goto error_release_sock;
638 	}
639 
640 	call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
641 	if (!call) {
642 		ret = -EBADSLT;
643 		if (p.command != RXRPC_CMD_SEND_DATA)
644 			goto error_release_sock;
645 		call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
646 		/* The socket is now unlocked... */
647 		if (IS_ERR(call))
648 			return PTR_ERR(call);
649 		/* ... and we have the call lock. */
650 		p.call.nr_timeouts = 0;
651 		ret = 0;
652 		if (rxrpc_call_is_complete(call))
653 			goto out_put_unlock;
654 	} else {
655 		switch (rxrpc_call_state(call)) {
656 		case RXRPC_CALL_CLIENT_AWAIT_CONN:
657 		case RXRPC_CALL_SERVER_SECURING:
658 			if (p.command == RXRPC_CMD_SEND_ABORT)
659 				break;
660 			fallthrough;
661 		case RXRPC_CALL_UNINITIALISED:
662 		case RXRPC_CALL_SERVER_PREALLOC:
663 			rxrpc_put_call(call, rxrpc_call_put_sendmsg);
664 			ret = -EBUSY;
665 			goto error_release_sock;
666 		default:
667 			break;
668 		}
669 
670 		ret = mutex_lock_interruptible(&call->user_mutex);
671 		release_sock(&rx->sk);
672 		if (ret < 0) {
673 			ret = -ERESTARTSYS;
674 			goto error_put;
675 		}
676 
677 		if (p.call.tx_total_len != -1) {
678 			ret = -EINVAL;
679 			if (call->tx_total_len != -1 ||
680 			    call->tx_pending ||
681 			    call->tx_top != 0)
682 				goto out_put_unlock;
683 			call->tx_total_len = p.call.tx_total_len;
684 		}
685 	}
686 
687 	switch (p.call.nr_timeouts) {
688 	case 3:
689 		WRITE_ONCE(call->next_rx_timo, p.call.timeouts.normal);
690 		fallthrough;
691 	case 2:
692 		WRITE_ONCE(call->next_req_timo, p.call.timeouts.idle);
693 		fallthrough;
694 	case 1:
695 		if (p.call.timeouts.hard > 0) {
696 			ktime_t delay = ms_to_ktime(p.call.timeouts.hard * MSEC_PER_SEC);
697 
698 			WRITE_ONCE(call->expect_term_by,
699 				   ktime_add(p.call.timeouts.hard,
700 					     ktime_get_real()));
701 			trace_rxrpc_timer_set(call, delay, rxrpc_timer_trace_hard);
702 			rxrpc_poke_call(call, rxrpc_call_poke_set_timeout);
703 
704 		}
705 		break;
706 	}
707 
708 	if (rxrpc_call_is_complete(call)) {
709 		/* it's too late for this call */
710 		ret = -ESHUTDOWN;
711 	} else if (p.command == RXRPC_CMD_SEND_ABORT) {
712 		rxrpc_propose_abort(call, p.abort_code, -ECONNABORTED,
713 				    rxrpc_abort_call_sendmsg);
714 		ret = 0;
715 	} else if (p.command != RXRPC_CMD_SEND_DATA) {
716 		ret = -EINVAL;
717 	} else {
718 		ret = rxrpc_send_data(rx, call, msg, len, NULL, &dropped_lock);
719 	}
720 
721 out_put_unlock:
722 	if (!dropped_lock)
723 		mutex_unlock(&call->user_mutex);
724 error_put:
725 	rxrpc_put_call(call, rxrpc_call_put_sendmsg);
726 	_leave(" = %d", ret);
727 	return ret;
728 
729 error_release_sock:
730 	release_sock(&rx->sk);
731 	return ret;
732 }
733 
734 /**
735  * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
736  * @sock: The socket the call is on
737  * @call: The call to send data through
738  * @msg: The data to send
739  * @len: The amount of data to send
740  * @notify_end_tx: Notification that the last packet is queued.
741  *
742  * Allow a kernel service to send data on a call.  The call must be in an state
743  * appropriate to sending data.  No control data should be supplied in @msg,
744  * nor should an address be supplied.  MSG_MORE should be flagged if there's
745  * more data to come, otherwise this data will end the transmission phase.
746  */
747 int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
748 			   struct msghdr *msg, size_t len,
749 			   rxrpc_notify_end_tx_t notify_end_tx)
750 {
751 	bool dropped_lock = false;
752 	int ret;
753 
754 	_enter("{%d},", call->debug_id);
755 
756 	ASSERTCMP(msg->msg_name, ==, NULL);
757 	ASSERTCMP(msg->msg_control, ==, NULL);
758 
759 	mutex_lock(&call->user_mutex);
760 
761 	ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
762 			      notify_end_tx, &dropped_lock);
763 	if (ret == -ESHUTDOWN)
764 		ret = call->error;
765 
766 	if (!dropped_lock)
767 		mutex_unlock(&call->user_mutex);
768 	_leave(" = %d", ret);
769 	return ret;
770 }
771 EXPORT_SYMBOL(rxrpc_kernel_send_data);
772 
773 /**
774  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
775  * @sock: The socket the call is on
776  * @call: The call to be aborted
777  * @abort_code: The abort code to stick into the ABORT packet
778  * @error: Local error value
779  * @why: Indication as to why.
780  *
781  * Allow a kernel service to abort a call, if it's still in an abortable state
782  * and return true if the call was aborted, false if it was already complete.
783  */
784 bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
785 			     u32 abort_code, int error, enum rxrpc_abort_reason why)
786 {
787 	bool aborted;
788 
789 	_enter("{%d},%d,%d,%u", call->debug_id, abort_code, error, why);
790 
791 	mutex_lock(&call->user_mutex);
792 	aborted = rxrpc_propose_abort(call, abort_code, error, why);
793 	mutex_unlock(&call->user_mutex);
794 	return aborted;
795 }
796 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
797 
798 /**
799  * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
800  * @sock: The socket the call is on
801  * @call: The call to be informed
802  * @tx_total_len: The amount of data to be transmitted for this call
803  *
804  * Allow a kernel service to set the total transmit length on a call.  This
805  * allows buffer-to-packet encrypt-and-copy to be performed.
806  *
807  * This function is primarily for use for setting the reply length since the
808  * request length can be set when beginning the call.
809  */
810 void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
811 				s64 tx_total_len)
812 {
813 	WARN_ON(call->tx_total_len != -1);
814 	call->tx_total_len = tx_total_len;
815 }
816 EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);
817