xref: /linux/net/rxrpc/sendmsg.c (revision 95f68e06b41b9e88291796efa3969409d13fdd4c)
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 		trace_rxrpc_abort_call(call, abort_code);
33 		/* Request abort locklessly vs rxrpc_input_call_event(). */
34 		smp_store_release(&call->send_abort, abort_code);
35 		rxrpc_poke_call(call, rxrpc_call_poke_abort);
36 		return true;
37 	}
38 
39 	return false;
40 }
41 
42 /*
43  * Wait for a call to become connected.  Interruption here doesn't cause the
44  * call to be aborted.
45  */
46 static int rxrpc_wait_to_be_connected(struct rxrpc_call *call, long *timeo)
47 {
48 	DECLARE_WAITQUEUE(myself, current);
49 	int ret = 0;
50 
51 	_enter("%d", call->debug_id);
52 
53 	if (rxrpc_call_state(call) != RXRPC_CALL_CLIENT_AWAIT_CONN)
54 		goto no_wait;
55 
56 	add_wait_queue_exclusive(&call->waitq, &myself);
57 
58 	for (;;) {
59 		switch (call->interruptibility) {
60 		case RXRPC_INTERRUPTIBLE:
61 		case RXRPC_PREINTERRUPTIBLE:
62 			set_current_state(TASK_INTERRUPTIBLE);
63 			break;
64 		case RXRPC_UNINTERRUPTIBLE:
65 		default:
66 			set_current_state(TASK_UNINTERRUPTIBLE);
67 			break;
68 		}
69 
70 		if (rxrpc_call_state(call) != RXRPC_CALL_CLIENT_AWAIT_CONN)
71 			break;
72 		if ((call->interruptibility == RXRPC_INTERRUPTIBLE ||
73 		     call->interruptibility == RXRPC_PREINTERRUPTIBLE) &&
74 		    signal_pending(current)) {
75 			ret = sock_intr_errno(*timeo);
76 			break;
77 		}
78 		*timeo = schedule_timeout(*timeo);
79 	}
80 
81 	remove_wait_queue(&call->waitq, &myself);
82 	__set_current_state(TASK_RUNNING);
83 
84 no_wait:
85 	if (ret == 0 && rxrpc_call_is_complete(call))
86 		ret = call->error;
87 
88 	_leave(" = %d", ret);
89 	return ret;
90 }
91 
92 /*
93  * Return true if there's sufficient Tx queue space.
94  */
95 static bool rxrpc_check_tx_space(struct rxrpc_call *call, rxrpc_seq_t *_tx_win)
96 {
97 	rxrpc_seq_t tx_bottom = READ_ONCE(call->tx_bottom);
98 
99 	if (_tx_win)
100 		*_tx_win = tx_bottom;
101 	return call->send_top - tx_bottom < 256;
102 }
103 
104 /*
105  * Wait for space to appear in the Tx queue or a signal to occur.
106  */
107 static int rxrpc_wait_for_tx_window_intr(struct rxrpc_sock *rx,
108 					 struct rxrpc_call *call,
109 					 long *timeo)
110 {
111 	for (;;) {
112 		set_current_state(TASK_INTERRUPTIBLE);
113 		if (rxrpc_check_tx_space(call, NULL))
114 			return 0;
115 
116 		if (rxrpc_call_is_complete(call))
117 			return call->error;
118 
119 		if (signal_pending(current))
120 			return sock_intr_errno(*timeo);
121 
122 		trace_rxrpc_txqueue(call, rxrpc_txqueue_wait);
123 		*timeo = schedule_timeout(*timeo);
124 	}
125 }
126 
127 /*
128  * Wait for space to appear in the Tx queue uninterruptibly, but with
129  * a timeout of 2*RTT if no progress was made and a signal occurred.
130  */
131 static int rxrpc_wait_for_tx_window_waitall(struct rxrpc_sock *rx,
132 					    struct rxrpc_call *call)
133 {
134 	rxrpc_seq_t tx_start, tx_win;
135 	signed long rtt, timeout;
136 
137 	rtt = READ_ONCE(call->srtt_us) >> 3;
138 	rtt = usecs_to_jiffies(rtt) * 2;
139 	if (rtt < 2)
140 		rtt = 2;
141 
142 	timeout = rtt;
143 	tx_start = READ_ONCE(call->tx_bottom);
144 
145 	for (;;) {
146 		set_current_state(TASK_UNINTERRUPTIBLE);
147 
148 		if (rxrpc_check_tx_space(call, &tx_win))
149 			return 0;
150 
151 		if (rxrpc_call_is_complete(call))
152 			return call->error;
153 
154 		if (timeout == 0 &&
155 		    tx_win == tx_start && signal_pending(current))
156 			return -EINTR;
157 
158 		if (tx_win != tx_start) {
159 			timeout = rtt;
160 			tx_start = tx_win;
161 		}
162 
163 		trace_rxrpc_txqueue(call, rxrpc_txqueue_wait);
164 		timeout = schedule_timeout(timeout);
165 	}
166 }
167 
168 /*
169  * Wait for space to appear in the Tx queue uninterruptibly.
170  */
171 static int rxrpc_wait_for_tx_window_nonintr(struct rxrpc_sock *rx,
172 					    struct rxrpc_call *call,
173 					    long *timeo)
174 {
175 	for (;;) {
176 		set_current_state(TASK_UNINTERRUPTIBLE);
177 		if (rxrpc_check_tx_space(call, NULL))
178 			return 0;
179 
180 		if (rxrpc_call_is_complete(call))
181 			return call->error;
182 
183 		trace_rxrpc_txqueue(call, rxrpc_txqueue_wait);
184 		*timeo = schedule_timeout(*timeo);
185 	}
186 }
187 
188 /*
189  * wait for space to appear in the transmit/ACK window
190  * - caller holds the socket locked
191  */
192 static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
193 				    struct rxrpc_call *call,
194 				    long *timeo,
195 				    bool waitall)
196 {
197 	DECLARE_WAITQUEUE(myself, current);
198 	int ret;
199 
200 	_enter(",{%u,%u,%u}",
201 	       call->tx_bottom, call->tx_top, call->tx_winsize);
202 
203 	add_wait_queue(&call->waitq, &myself);
204 
205 	switch (call->interruptibility) {
206 	case RXRPC_INTERRUPTIBLE:
207 		if (waitall)
208 			ret = rxrpc_wait_for_tx_window_waitall(rx, call);
209 		else
210 			ret = rxrpc_wait_for_tx_window_intr(rx, call, timeo);
211 		break;
212 	case RXRPC_PREINTERRUPTIBLE:
213 	case RXRPC_UNINTERRUPTIBLE:
214 	default:
215 		ret = rxrpc_wait_for_tx_window_nonintr(rx, call, timeo);
216 		break;
217 	}
218 
219 	remove_wait_queue(&call->waitq, &myself);
220 	set_current_state(TASK_RUNNING);
221 	_leave(" = %d", ret);
222 	return ret;
223 }
224 
225 /*
226  * Notify the owner of the call that the transmit phase is ended and the last
227  * packet has been queued.
228  */
229 static void rxrpc_notify_end_tx(struct rxrpc_sock *rx, struct rxrpc_call *call,
230 				rxrpc_notify_end_tx_t notify_end_tx)
231 {
232 	if (notify_end_tx)
233 		notify_end_tx(&rx->sk, call, call->user_call_ID);
234 }
235 
236 /*
237  * Queue a DATA packet for transmission, set the resend timeout and send
238  * the packet immediately.  Returns the error from rxrpc_send_data_packet()
239  * in case the caller wants to do something with it.
240  */
241 static void rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
242 			       struct rxrpc_txbuf *txb,
243 			       rxrpc_notify_end_tx_t notify_end_tx)
244 {
245 	struct rxrpc_txqueue *sq = call->send_queue;
246 	rxrpc_seq_t seq = txb->seq;
247 	bool poke, last = txb->flags & RXRPC_LAST_PACKET;
248 	int ix = seq & RXRPC_TXQ_MASK;
249 	rxrpc_inc_stat(call->rxnet, stat_tx_data);
250 
251 	ASSERTCMP(txb->seq, ==, call->send_top + 1);
252 
253 	if (last)
254 		trace_rxrpc_txqueue(call, rxrpc_txqueue_queue_last);
255 	else
256 		trace_rxrpc_txqueue(call, rxrpc_txqueue_queue);
257 
258 	if (WARN_ON_ONCE(sq->bufs[ix]))
259 		trace_rxrpc_tq(call, sq, seq, rxrpc_tq_queue_dup);
260 	else
261 		trace_rxrpc_tq(call, sq, seq, rxrpc_tq_queue);
262 
263 	/* Add the packet to the call's output buffer */
264 	poke = (READ_ONCE(call->tx_bottom) == call->send_top);
265 	sq->bufs[ix] = txb;
266 	/* Order send_top after the queue->next pointer and txb content. */
267 	smp_store_release(&call->send_top, seq);
268 	if (last) {
269 		set_bit(RXRPC_CALL_TX_NO_MORE, &call->flags);
270 		rxrpc_notify_end_tx(rx, call, notify_end_tx);
271 		call->send_queue = NULL;
272 	}
273 
274 	if (poke)
275 		rxrpc_poke_call(call, rxrpc_call_poke_start);
276 }
277 
278 /*
279  * Allocate a new txqueue unit and add it to the transmission queue.
280  */
281 static int rxrpc_alloc_txqueue(struct sock *sk, struct rxrpc_call *call)
282 {
283 	struct rxrpc_txqueue *tq;
284 
285 	tq = kzalloc(sizeof(*tq), sk->sk_allocation);
286 	if (!tq)
287 		return -ENOMEM;
288 
289 	tq->xmit_ts_base = KTIME_MIN;
290 	for (int i = 0; i < RXRPC_NR_TXQUEUE; i++)
291 		tq->segment_xmit_ts[i] = UINT_MAX;
292 
293 	if (call->send_queue) {
294 		tq->qbase = call->send_top + 1;
295 		call->send_queue->next = tq;
296 		call->send_queue = tq;
297 	} else if (WARN_ON(call->tx_queue)) {
298 		kfree(tq);
299 		return -ENOMEM;
300 	} else {
301 		/* We start at seq 1, so pretend seq 0 is hard-acked. */
302 		tq->nr_reported_acks = 1;
303 		tq->segment_acked = 1UL;
304 		tq->qbase = 0;
305 		call->tx_qbase = 0;
306 		call->send_queue = tq;
307 		call->tx_qtail = tq;
308 		call->tx_queue = tq;
309 	}
310 
311 	trace_rxrpc_tq(call, tq, call->send_top, rxrpc_tq_alloc);
312 	return 0;
313 }
314 
315 /*
316  * send data through a socket
317  * - must be called in process context
318  * - The caller holds the call user access mutex, but not the socket lock.
319  */
320 static int rxrpc_send_data(struct rxrpc_sock *rx,
321 			   struct rxrpc_call *call,
322 			   struct msghdr *msg, size_t len,
323 			   rxrpc_notify_end_tx_t notify_end_tx,
324 			   bool *_dropped_lock)
325 {
326 	struct rxrpc_txbuf *txb;
327 	struct sock *sk = &rx->sk;
328 	enum rxrpc_call_state state;
329 	long timeo;
330 	bool more = msg->msg_flags & MSG_MORE;
331 	int ret, copied = 0;
332 
333 	if (test_bit(RXRPC_CALL_TX_NO_MORE, &call->flags)) {
334 		trace_rxrpc_abort(call->debug_id, rxrpc_sendmsg_late_send,
335 				  call->cid, call->call_id, call->rx_consumed,
336 				  0, -EPROTO);
337 		return -EPROTO;
338 	}
339 
340 	timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
341 
342 	ret = rxrpc_wait_to_be_connected(call, &timeo);
343 	if (ret < 0)
344 		return ret;
345 
346 	if (call->conn->state == RXRPC_CONN_CLIENT_UNSECURED) {
347 		ret = rxrpc_init_client_conn_security(call->conn);
348 		if (ret < 0)
349 			return ret;
350 	}
351 
352 	/* this should be in poll */
353 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
354 
355 reload:
356 	txb = call->tx_pending;
357 	call->tx_pending = NULL;
358 	if (txb)
359 		rxrpc_see_txbuf(txb, rxrpc_txbuf_see_send_more);
360 
361 	ret = -EPIPE;
362 	if (sk->sk_shutdown & SEND_SHUTDOWN)
363 		goto maybe_error;
364 	state = rxrpc_call_state(call);
365 	ret = -ESHUTDOWN;
366 	if (state >= RXRPC_CALL_COMPLETE)
367 		goto maybe_error;
368 	ret = -EPROTO;
369 	if (state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
370 	    state != RXRPC_CALL_SERVER_ACK_REQUEST &&
371 	    state != RXRPC_CALL_SERVER_SEND_REPLY) {
372 		/* Request phase complete for this client call */
373 		trace_rxrpc_abort(call->debug_id, rxrpc_sendmsg_late_send,
374 				  call->cid, call->call_id, call->rx_consumed,
375 				  0, -EPROTO);
376 		goto maybe_error;
377 	}
378 
379 	ret = -EMSGSIZE;
380 	if (call->tx_total_len != -1) {
381 		if (len - copied > call->tx_total_len)
382 			goto maybe_error;
383 		if (!more && len - copied != call->tx_total_len)
384 			goto maybe_error;
385 	}
386 
387 	do {
388 		if (!txb) {
389 			size_t remain;
390 
391 			_debug("alloc");
392 
393 			if (!rxrpc_check_tx_space(call, NULL))
394 				goto wait_for_space;
395 
396 			/* See if we need to begin/extend the Tx queue. */
397 			if (!call->send_queue || !((call->send_top + 1) & RXRPC_TXQ_MASK)) {
398 				ret = rxrpc_alloc_txqueue(sk, call);
399 				if (ret < 0)
400 					goto maybe_error;
401 			}
402 
403 			/* Work out the maximum size of a packet.  Assume that
404 			 * the security header is going to be in the padded
405 			 * region (enc blocksize), but the trailer is not.
406 			 */
407 			remain = more ? INT_MAX : msg_data_left(msg);
408 			txb = call->conn->security->alloc_txbuf(call, remain, sk->sk_allocation);
409 			if (!txb) {
410 				ret = -ENOMEM;
411 				goto maybe_error;
412 			}
413 		}
414 
415 		_debug("append");
416 
417 		/* append next segment of data to the current buffer */
418 		if (msg_data_left(msg) > 0) {
419 			size_t copy = umin(txb->space, msg_data_left(msg));
420 
421 			_debug("add %zu", copy);
422 			if (!copy_from_iter_full(txb->kvec[0].iov_base + txb->offset,
423 						 copy, &msg->msg_iter))
424 				goto efault;
425 			_debug("added");
426 			txb->space -= copy;
427 			txb->len += copy;
428 			txb->offset += copy;
429 			copied += copy;
430 			if (call->tx_total_len != -1)
431 				call->tx_total_len -= copy;
432 		}
433 
434 		/* check for the far side aborting the call or a network error
435 		 * occurring */
436 		if (rxrpc_call_is_complete(call))
437 			goto call_terminated;
438 
439 		/* add the packet to the send queue if it's now full */
440 		if (!txb->space ||
441 		    (msg_data_left(msg) == 0 && !more)) {
442 			if (msg_data_left(msg) == 0 && !more)
443 				txb->flags |= RXRPC_LAST_PACKET;
444 
445 			ret = call->security->secure_packet(call, txb);
446 			if (ret < 0)
447 				goto out;
448 
449 			txb->kvec[0].iov_len += txb->len;
450 			rxrpc_queue_packet(rx, call, txb, notify_end_tx);
451 			txb = NULL;
452 		}
453 	} while (msg_data_left(msg) > 0);
454 
455 success:
456 	ret = copied;
457 	if (rxrpc_call_is_complete(call) &&
458 	    call->error < 0)
459 		ret = call->error;
460 out:
461 	call->tx_pending = txb;
462 	_leave(" = %d", ret);
463 	return ret;
464 
465 call_terminated:
466 	rxrpc_put_txbuf(txb, rxrpc_txbuf_put_send_aborted);
467 	_leave(" = %d", call->error);
468 	return call->error;
469 
470 maybe_error:
471 	if (copied)
472 		goto success;
473 	goto out;
474 
475 efault:
476 	ret = -EFAULT;
477 	goto out;
478 
479 wait_for_space:
480 	ret = -EAGAIN;
481 	if (msg->msg_flags & MSG_DONTWAIT)
482 		goto maybe_error;
483 	mutex_unlock(&call->user_mutex);
484 	*_dropped_lock = true;
485 	ret = rxrpc_wait_for_tx_window(rx, call, &timeo,
486 				       msg->msg_flags & MSG_WAITALL);
487 	if (ret < 0)
488 		goto maybe_error;
489 	if (call->interruptibility == RXRPC_INTERRUPTIBLE) {
490 		if (mutex_lock_interruptible(&call->user_mutex) < 0) {
491 			ret = sock_intr_errno(timeo);
492 			goto maybe_error;
493 		}
494 	} else {
495 		mutex_lock(&call->user_mutex);
496 	}
497 	*_dropped_lock = false;
498 	goto reload;
499 }
500 
501 /*
502  * extract control messages from the sendmsg() control buffer
503  */
504 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
505 {
506 	struct cmsghdr *cmsg;
507 	bool got_user_ID = false;
508 	int len;
509 
510 	if (msg->msg_controllen == 0)
511 		return -EINVAL;
512 
513 	for_each_cmsghdr(cmsg, msg) {
514 		if (!CMSG_OK(msg, cmsg))
515 			return -EINVAL;
516 
517 		len = cmsg->cmsg_len - sizeof(struct cmsghdr);
518 		_debug("CMSG %d, %d, %d",
519 		       cmsg->cmsg_level, cmsg->cmsg_type, len);
520 
521 		if (cmsg->cmsg_level != SOL_RXRPC)
522 			continue;
523 
524 		switch (cmsg->cmsg_type) {
525 		case RXRPC_USER_CALL_ID:
526 			if (msg->msg_flags & MSG_CMSG_COMPAT) {
527 				if (len != sizeof(u32))
528 					return -EINVAL;
529 				p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
530 			} else {
531 				if (len != sizeof(unsigned long))
532 					return -EINVAL;
533 				p->call.user_call_ID = *(unsigned long *)
534 					CMSG_DATA(cmsg);
535 			}
536 			got_user_ID = true;
537 			break;
538 
539 		case RXRPC_ABORT:
540 			if (p->command != RXRPC_CMD_SEND_DATA)
541 				return -EINVAL;
542 			p->command = RXRPC_CMD_SEND_ABORT;
543 			if (len != sizeof(p->abort_code))
544 				return -EINVAL;
545 			p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
546 			if (p->abort_code == 0)
547 				return -EINVAL;
548 			break;
549 
550 		case RXRPC_CHARGE_ACCEPT:
551 			if (p->command != RXRPC_CMD_SEND_DATA)
552 				return -EINVAL;
553 			p->command = RXRPC_CMD_CHARGE_ACCEPT;
554 			if (len != 0)
555 				return -EINVAL;
556 			break;
557 
558 		case RXRPC_EXCLUSIVE_CALL:
559 			p->exclusive = true;
560 			if (len != 0)
561 				return -EINVAL;
562 			break;
563 
564 		case RXRPC_UPGRADE_SERVICE:
565 			p->upgrade = true;
566 			if (len != 0)
567 				return -EINVAL;
568 			break;
569 
570 		case RXRPC_TX_LENGTH:
571 			if (p->call.tx_total_len != -1 || len != sizeof(__s64))
572 				return -EINVAL;
573 			p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
574 			if (p->call.tx_total_len < 0)
575 				return -EINVAL;
576 			break;
577 
578 		case RXRPC_SET_CALL_TIMEOUT:
579 			if (len & 3 || len < 4 || len > 12)
580 				return -EINVAL;
581 			memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
582 			p->call.nr_timeouts = len / 4;
583 			if (p->call.timeouts.hard > INT_MAX / HZ)
584 				return -ERANGE;
585 			if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
586 				return -ERANGE;
587 			if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
588 				return -ERANGE;
589 			break;
590 
591 		default:
592 			return -EINVAL;
593 		}
594 	}
595 
596 	if (!got_user_ID)
597 		return -EINVAL;
598 	if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
599 		return -EINVAL;
600 	_leave(" = 0");
601 	return 0;
602 }
603 
604 /*
605  * Create a new client call for sendmsg().
606  * - Called with the socket lock held, which it must release.
607  * - If it returns a call, the call's lock will need releasing by the caller.
608  */
609 static struct rxrpc_call *
610 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
611 				  struct rxrpc_send_params *p)
612 	__releases(&rx->sk.sk_lock.slock)
613 	__acquires(&call->user_mutex)
614 {
615 	struct rxrpc_conn_parameters cp;
616 	struct rxrpc_peer *peer;
617 	struct rxrpc_call *call;
618 	struct key *key;
619 
620 	DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
621 
622 	_enter("");
623 
624 	if (!msg->msg_name) {
625 		release_sock(&rx->sk);
626 		return ERR_PTR(-EDESTADDRREQ);
627 	}
628 
629 	peer = rxrpc_lookup_peer(rx->local, srx, GFP_KERNEL);
630 	if (!peer) {
631 		release_sock(&rx->sk);
632 		return ERR_PTR(-ENOMEM);
633 	}
634 
635 	key = rx->key;
636 	if (key && !rx->key->payload.data[0])
637 		key = NULL;
638 
639 	memset(&cp, 0, sizeof(cp));
640 	cp.local		= rx->local;
641 	cp.peer			= peer;
642 	cp.key			= rx->key;
643 	cp.security_level	= rx->min_sec_level;
644 	cp.exclusive		= rx->exclusive | p->exclusive;
645 	cp.upgrade		= p->upgrade;
646 	cp.service_id		= srx->srx_service;
647 	call = rxrpc_new_client_call(rx, &cp, &p->call, GFP_KERNEL,
648 				     atomic_inc_return(&rxrpc_debug_id));
649 	/* The socket is now unlocked */
650 
651 	rxrpc_put_peer(peer, rxrpc_peer_put_application);
652 	_leave(" = %p\n", call);
653 	return call;
654 }
655 
656 /*
657  * send a message forming part of a client call through an RxRPC socket
658  * - caller holds the socket locked
659  * - the socket may be either a client socket or a server socket
660  */
661 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
662 	__releases(&rx->sk.sk_lock.slock)
663 {
664 	struct rxrpc_call *call;
665 	bool dropped_lock = false;
666 	int ret;
667 
668 	struct rxrpc_send_params p = {
669 		.call.tx_total_len	= -1,
670 		.call.user_call_ID	= 0,
671 		.call.nr_timeouts	= 0,
672 		.call.interruptibility	= RXRPC_INTERRUPTIBLE,
673 		.abort_code		= 0,
674 		.command		= RXRPC_CMD_SEND_DATA,
675 		.exclusive		= false,
676 		.upgrade		= false,
677 	};
678 
679 	_enter("");
680 
681 	ret = rxrpc_sendmsg_cmsg(msg, &p);
682 	if (ret < 0)
683 		goto error_release_sock;
684 
685 	if (p.command == RXRPC_CMD_CHARGE_ACCEPT) {
686 		ret = -EINVAL;
687 		if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
688 			goto error_release_sock;
689 		ret = rxrpc_user_charge_accept(rx, p.call.user_call_ID);
690 		goto error_release_sock;
691 	}
692 
693 	call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
694 	if (!call) {
695 		ret = -EBADSLT;
696 		if (p.command != RXRPC_CMD_SEND_DATA)
697 			goto error_release_sock;
698 		call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
699 		/* The socket is now unlocked... */
700 		if (IS_ERR(call))
701 			return PTR_ERR(call);
702 		/* ... and we have the call lock. */
703 		p.call.nr_timeouts = 0;
704 		ret = 0;
705 		if (rxrpc_call_is_complete(call))
706 			goto out_put_unlock;
707 	} else {
708 		switch (rxrpc_call_state(call)) {
709 		case RXRPC_CALL_CLIENT_AWAIT_CONN:
710 		case RXRPC_CALL_SERVER_SECURING:
711 			if (p.command == RXRPC_CMD_SEND_ABORT)
712 				break;
713 			fallthrough;
714 		case RXRPC_CALL_UNINITIALISED:
715 		case RXRPC_CALL_SERVER_PREALLOC:
716 			rxrpc_put_call(call, rxrpc_call_put_sendmsg);
717 			ret = -EBUSY;
718 			goto error_release_sock;
719 		default:
720 			break;
721 		}
722 
723 		ret = mutex_lock_interruptible(&call->user_mutex);
724 		release_sock(&rx->sk);
725 		if (ret < 0) {
726 			ret = -ERESTARTSYS;
727 			goto error_put;
728 		}
729 
730 		if (p.call.tx_total_len != -1) {
731 			ret = -EINVAL;
732 			if (call->tx_total_len != -1 ||
733 			    call->tx_pending ||
734 			    call->tx_top != 0)
735 				goto out_put_unlock;
736 			call->tx_total_len = p.call.tx_total_len;
737 		}
738 	}
739 
740 	switch (p.call.nr_timeouts) {
741 	case 3:
742 		WRITE_ONCE(call->next_rx_timo, p.call.timeouts.normal);
743 		fallthrough;
744 	case 2:
745 		WRITE_ONCE(call->next_req_timo, p.call.timeouts.idle);
746 		fallthrough;
747 	case 1:
748 		if (p.call.timeouts.hard > 0) {
749 			ktime_t delay = ms_to_ktime(p.call.timeouts.hard * MSEC_PER_SEC);
750 
751 			WRITE_ONCE(call->expect_term_by,
752 				   ktime_add(p.call.timeouts.hard,
753 					     ktime_get_real()));
754 			trace_rxrpc_timer_set(call, delay, rxrpc_timer_trace_hard);
755 			rxrpc_poke_call(call, rxrpc_call_poke_set_timeout);
756 
757 		}
758 		break;
759 	}
760 
761 	if (rxrpc_call_is_complete(call)) {
762 		/* it's too late for this call */
763 		ret = -ESHUTDOWN;
764 	} else if (p.command == RXRPC_CMD_SEND_ABORT) {
765 		rxrpc_propose_abort(call, p.abort_code, -ECONNABORTED,
766 				    rxrpc_abort_call_sendmsg);
767 		ret = 0;
768 	} else if (p.command != RXRPC_CMD_SEND_DATA) {
769 		ret = -EINVAL;
770 	} else {
771 		ret = rxrpc_send_data(rx, call, msg, len, NULL, &dropped_lock);
772 	}
773 
774 out_put_unlock:
775 	if (!dropped_lock)
776 		mutex_unlock(&call->user_mutex);
777 error_put:
778 	rxrpc_put_call(call, rxrpc_call_put_sendmsg);
779 	_leave(" = %d", ret);
780 	return ret;
781 
782 error_release_sock:
783 	release_sock(&rx->sk);
784 	return ret;
785 }
786 
787 /**
788  * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
789  * @sock: The socket the call is on
790  * @call: The call to send data through
791  * @msg: The data to send
792  * @len: The amount of data to send
793  * @notify_end_tx: Notification that the last packet is queued.
794  *
795  * Allow a kernel service to send data on a call.  The call must be in an state
796  * appropriate to sending data.  No control data should be supplied in @msg,
797  * nor should an address be supplied.  MSG_MORE should be flagged if there's
798  * more data to come, otherwise this data will end the transmission phase.
799  */
800 int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
801 			   struct msghdr *msg, size_t len,
802 			   rxrpc_notify_end_tx_t notify_end_tx)
803 {
804 	bool dropped_lock = false;
805 	int ret;
806 
807 	_enter("{%d},", call->debug_id);
808 
809 	ASSERTCMP(msg->msg_name, ==, NULL);
810 	ASSERTCMP(msg->msg_control, ==, NULL);
811 
812 	mutex_lock(&call->user_mutex);
813 
814 	ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
815 			      notify_end_tx, &dropped_lock);
816 	if (ret == -ESHUTDOWN)
817 		ret = call->error;
818 
819 	if (!dropped_lock)
820 		mutex_unlock(&call->user_mutex);
821 	_leave(" = %d", ret);
822 	return ret;
823 }
824 EXPORT_SYMBOL(rxrpc_kernel_send_data);
825 
826 /**
827  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
828  * @sock: The socket the call is on
829  * @call: The call to be aborted
830  * @abort_code: The abort code to stick into the ABORT packet
831  * @error: Local error value
832  * @why: Indication as to why.
833  *
834  * Allow a kernel service to abort a call, if it's still in an abortable state
835  * and return true if the call was aborted, false if it was already complete.
836  */
837 bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
838 			     u32 abort_code, int error, enum rxrpc_abort_reason why)
839 {
840 	bool aborted;
841 
842 	_enter("{%d},%d,%d,%u", call->debug_id, abort_code, error, why);
843 
844 	mutex_lock(&call->user_mutex);
845 	aborted = rxrpc_propose_abort(call, abort_code, error, why);
846 	mutex_unlock(&call->user_mutex);
847 	return aborted;
848 }
849 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
850 
851 /**
852  * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
853  * @sock: The socket the call is on
854  * @call: The call to be informed
855  * @tx_total_len: The amount of data to be transmitted for this call
856  *
857  * Allow a kernel service to set the total transmit length on a call.  This
858  * allows buffer-to-packet encrypt-and-copy to be performed.
859  *
860  * This function is primarily for use for setting the reply length since the
861  * request length can be set when beginning the call.
862  */
863 void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
864 				s64 tx_total_len)
865 {
866 	WARN_ON(call->tx_total_len != -1);
867 	call->tx_total_len = tx_total_len;
868 }
869 EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);
870