sendmsg.c

  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 */
 23bool 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 */
 46static 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
 84no_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 */
 95static 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 */
107static 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 */
131static 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 */
171static 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 */
192static 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 */
229static 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 */
241static 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 */
281static 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 */
320static 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
355reload:
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->data + 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			rxrpc_queue_packet(rx, call, txb, notify_end_tx);
449			txb = NULL;
450		}
451	} while (msg_data_left(msg) > 0);
452
453success:
454	ret = copied;
455	if (rxrpc_call_is_complete(call) &&
456	    call->error < 0)
457		ret = call->error;
458out:
459	call->tx_pending = txb;
460	_leave(" = %d", ret);
461	return ret;
462
463call_terminated:
464	rxrpc_put_txbuf(txb, rxrpc_txbuf_put_send_aborted);
465	_leave(" = %d", call->error);
466	return call->error;
467
468maybe_error:
469	if (copied)
470		goto success;
471	goto out;
472
473efault:
474	ret = -EFAULT;
475	goto out;
476
477wait_for_space:
478	ret = -EAGAIN;
479	if (msg->msg_flags & MSG_DONTWAIT)
480		goto maybe_error;
481	mutex_unlock(&call->user_mutex);
482	*_dropped_lock = true;
483	ret = rxrpc_wait_for_tx_window(rx, call, &timeo,
484				       msg->msg_flags & MSG_WAITALL);
485	if (ret < 0)
486		goto maybe_error;
487	if (call->interruptibility == RXRPC_INTERRUPTIBLE) {
488		if (mutex_lock_interruptible(&call->user_mutex) < 0) {
489			ret = sock_intr_errno(timeo);
490			goto maybe_error;
491		}
492	} else {
493		mutex_lock(&call->user_mutex);
494	}
495	*_dropped_lock = false;
496	goto reload;
497}
498
499/*
500 * extract control messages from the sendmsg() control buffer
501 */
502static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
503{
504	struct cmsghdr *cmsg;
505	bool got_user_ID = false;
506	int len;
507
508	if (msg->msg_controllen == 0)
509		return -EINVAL;
510
511	for_each_cmsghdr(cmsg, msg) {
512		if (!CMSG_OK(msg, cmsg))
513			return -EINVAL;
514
515		len = cmsg->cmsg_len - sizeof(struct cmsghdr);
516		_debug("CMSG %d, %d, %d",
517		       cmsg->cmsg_level, cmsg->cmsg_type, len);
518
519		if (cmsg->cmsg_level != SOL_RXRPC)
520			continue;
521
522		switch (cmsg->cmsg_type) {
523		case RXRPC_USER_CALL_ID:
524			if (msg->msg_flags & MSG_CMSG_COMPAT) {
525				if (len != sizeof(u32))
526					return -EINVAL;
527				p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
528			} else {
529				if (len != sizeof(unsigned long))
530					return -EINVAL;
531				p->call.user_call_ID = *(unsigned long *)
532					CMSG_DATA(cmsg);
533			}
534			got_user_ID = true;
535			break;
536
537		case RXRPC_ABORT:
538			if (p->command != RXRPC_CMD_SEND_DATA)
539				return -EINVAL;
540			p->command = RXRPC_CMD_SEND_ABORT;
541			if (len != sizeof(p->abort_code))
542				return -EINVAL;
543			p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
544			if (p->abort_code == 0)
545				return -EINVAL;
546			break;
547
548		case RXRPC_CHARGE_ACCEPT:
549			if (p->command != RXRPC_CMD_SEND_DATA)
550				return -EINVAL;
551			p->command = RXRPC_CMD_CHARGE_ACCEPT;
552			if (len != 0)
553				return -EINVAL;
554			break;
555
556		case RXRPC_EXCLUSIVE_CALL:
557			p->exclusive = true;
558			if (len != 0)
559				return -EINVAL;
560			break;
561
562		case RXRPC_UPGRADE_SERVICE:
563			p->upgrade = true;
564			if (len != 0)
565				return -EINVAL;
566			break;
567
568		case RXRPC_TX_LENGTH:
569			if (p->call.tx_total_len != -1 || len != sizeof(__s64))
570				return -EINVAL;
571			p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
572			if (p->call.tx_total_len < 0)
573				return -EINVAL;
574			break;
575
576		case RXRPC_SET_CALL_TIMEOUT:
577			if (len & 3 || len < 4 || len > 12)
578				return -EINVAL;
579			memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
580			p->call.nr_timeouts = len / 4;
581			if (p->call.timeouts.hard > INT_MAX / HZ)
582				return -ERANGE;
583			if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
584				return -ERANGE;
585			if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
586				return -ERANGE;
587			break;
588
589		default:
590			return -EINVAL;
591		}
592	}
593
594	if (!got_user_ID)
595		return -EINVAL;
596	if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
597		return -EINVAL;
598	_leave(" = 0");
599	return 0;
600}
601
602/*
603 * Create a new client call for sendmsg().
604 * - Called with the socket lock held, which it must release.
605 * - If it returns a call, the call's lock will need releasing by the caller.
606 */
607static struct rxrpc_call *
608rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
609				  struct rxrpc_send_params *p)
610	__releases(&rx->sk.sk_lock)
611	__acquires(&call->user_mutex)
612{
613	struct rxrpc_conn_parameters cp;
614	struct rxrpc_peer *peer;
615	struct rxrpc_call *call;
616	struct key *key;
617
618	DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
619
620	_enter("");
621
622	if (!msg->msg_name) {
623		release_sock(&rx->sk);
624		return ERR_PTR(-EDESTADDRREQ);
625	}
626
627	peer = rxrpc_lookup_peer(rx->local, srx, GFP_KERNEL);
628	if (!peer) {
629		release_sock(&rx->sk);
630		return ERR_PTR(-ENOMEM);
631	}
632
633	key = rx->key;
634	if (key && !rx->key->payload.data[0])
635		key = NULL;
636
637	memset(&cp, 0, sizeof(cp));
638	cp.local		= rx->local;
639	cp.peer			= peer;
640	cp.key			= key;
641	cp.security_level	= rx->min_sec_level;
642	cp.exclusive		= rx->exclusive | p->exclusive;
643	cp.upgrade		= p->upgrade;
644	cp.service_id		= srx->srx_service;
645	call = rxrpc_new_client_call(rx, &cp, &p->call, GFP_KERNEL,
646				     atomic_inc_return(&rxrpc_debug_id));
647	/* The socket is now unlocked */
648
649	rxrpc_put_peer(peer, rxrpc_peer_put_application);
650	_leave(" = %p\n", call);
651	return call;
652}
653
654/*
655 * send a message forming part of a client call through an RxRPC socket
656 * - caller holds the socket locked
657 * - the socket may be either a client socket or a server socket
658 */
659int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
660{
661	struct rxrpc_call *call;
662	bool dropped_lock = false;
663	int ret;
664
665	struct rxrpc_send_params p = {
666		.call.tx_total_len	= -1,
667		.call.user_call_ID	= 0,
668		.call.nr_timeouts	= 0,
669		.call.interruptibility	= RXRPC_INTERRUPTIBLE,
670		.abort_code		= 0,
671		.command		= RXRPC_CMD_SEND_DATA,
672		.exclusive		= false,
673		.upgrade		= false,
674	};
675
676	_enter("");
677
678	ret = rxrpc_sendmsg_cmsg(msg, &p);
679	if (ret < 0)
680		goto error_release_sock;
681
682	if (p.command == RXRPC_CMD_CHARGE_ACCEPT) {
683		ret = -EINVAL;
684		if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
685			goto error_release_sock;
686		ret = rxrpc_user_charge_accept(rx, p.call.user_call_ID);
687		goto error_release_sock;
688	}
689
690	call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
691	if (!call) {
692		ret = -EBADSLT;
693		if (p.command != RXRPC_CMD_SEND_DATA)
694			goto error_release_sock;
695		call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
696		/* The socket is now unlocked... */
697		if (IS_ERR(call))
698			return PTR_ERR(call);
699		/* ... and we have the call lock. */
700		p.call.nr_timeouts = 0;
701		ret = 0;
702		if (rxrpc_call_is_complete(call))
703			goto out_put_unlock;
704	} else {
705		switch (rxrpc_call_state(call)) {
706		case RXRPC_CALL_CLIENT_AWAIT_CONN:
707		case RXRPC_CALL_SERVER_RECV_REQUEST:
708			if (p.command == RXRPC_CMD_SEND_ABORT)
709				break;
710			fallthrough;
711		case RXRPC_CALL_UNINITIALISED:
712		case RXRPC_CALL_SERVER_PREALLOC:
713			rxrpc_put_call(call, rxrpc_call_put_sendmsg);
714			ret = -EBUSY;
715			goto error_release_sock;
716		default:
717			break;
718		}
719
720		ret = mutex_lock_interruptible(&call->user_mutex);
721		release_sock(&rx->sk);
722		if (ret < 0) {
723			ret = -ERESTARTSYS;
724			goto error_put;
725		}
726
727		if (p.call.tx_total_len != -1) {
728			ret = -EINVAL;
729			if (call->tx_total_len != -1 ||
730			    call->tx_pending ||
731			    call->tx_top != 0)
732				goto out_put_unlock;
733			call->tx_total_len = p.call.tx_total_len;
734		}
735	}
736
737	switch (p.call.nr_timeouts) {
738	case 3:
739		WRITE_ONCE(call->next_rx_timo, p.call.timeouts.normal);
740		fallthrough;
741	case 2:
742		WRITE_ONCE(call->next_req_timo, p.call.timeouts.idle);
743		fallthrough;
744	case 1:
745		if (p.call.timeouts.hard > 0) {
746			ktime_t delay = ms_to_ktime(p.call.timeouts.hard * MSEC_PER_SEC);
747
748			WRITE_ONCE(call->expect_term_by,
749				   ktime_add(p.call.timeouts.hard,
750					     ktime_get_real()));
751			trace_rxrpc_timer_set(call, delay, rxrpc_timer_trace_hard);
752			rxrpc_poke_call(call, rxrpc_call_poke_set_timeout);
753
754		}
755		break;
756	}
757
758	if (rxrpc_call_is_complete(call)) {
759		/* it's too late for this call */
760		ret = -ESHUTDOWN;
761		goto out_put_unlock;
762	}
763
764	switch (p.command) {
765	case RXRPC_CMD_SEND_ABORT:
766		rxrpc_propose_abort(call, p.abort_code, -ECONNABORTED,
767				    rxrpc_abort_call_sendmsg);
768		ret = 0;
769		break;
770	case RXRPC_CMD_SEND_DATA:
771		ret = rxrpc_send_data(rx, call, msg, len, NULL, &dropped_lock);
772		break;
773	default:
774		ret = -EINVAL;
775		break;
776	}
777
778out_put_unlock:
779	if (!dropped_lock)
780		mutex_unlock(&call->user_mutex);
781error_put:
782	rxrpc_put_call(call, rxrpc_call_put_sendmsg);
783	_leave(" = %d", ret);
784	return ret;
785
786error_release_sock:
787	release_sock(&rx->sk);
788	return ret;
789}
790
791/**
792 * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
793 * @sock: The socket the call is on
794 * @call: The call to send data through
795 * @msg: The data to send
796 * @len: The amount of data to send
797 * @notify_end_tx: Notification that the last packet is queued.
798 *
799 * Allow a kernel service to send data on a call.  The call must be in an state
800 * appropriate to sending data.  No control data should be supplied in @msg,
801 * nor should an address be supplied.  MSG_MORE should be flagged if there's
802 * more data to come, otherwise this data will end the transmission phase.
803 *
804 * Return: %0 if successful and a negative error code otherwise.
805 */
806int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
807			   struct msghdr *msg, size_t len,
808			   rxrpc_notify_end_tx_t notify_end_tx)
809{
810	bool dropped_lock = false;
811	int ret;
812
813	_enter("{%d},", call->debug_id);
814
815	ASSERTCMP(msg->msg_name, ==, NULL);
816	ASSERTCMP(msg->msg_control, ==, NULL);
817
818	mutex_lock(&call->user_mutex);
819
820	ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
821			      notify_end_tx, &dropped_lock);
822	if (ret == -ESHUTDOWN)
823		ret = call->error;
824
825	if (!dropped_lock)
826		mutex_unlock(&call->user_mutex);
827	_leave(" = %d", ret);
828	return ret;
829}
830EXPORT_SYMBOL(rxrpc_kernel_send_data);
831
832/**
833 * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
834 * @sock: The socket the call is on
835 * @call: The call to be aborted
836 * @abort_code: The abort code to stick into the ABORT packet
837 * @error: Local error value
838 * @why: Indication as to why.
839 *
840 * Allow a kernel service to abort a call if it's still in an abortable state.
841 *
842 * Return: %true if the call was aborted, %false if it was already complete.
843 */
844bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
845			     u32 abort_code, int error, enum rxrpc_abort_reason why)
846{
847	bool aborted;
848
849	_enter("{%d},%d,%d,%u", call->debug_id, abort_code, error, why);
850
851	mutex_lock(&call->user_mutex);
852	aborted = rxrpc_propose_abort(call, abort_code, error, why);
853	mutex_unlock(&call->user_mutex);
854	return aborted;
855}
856EXPORT_SYMBOL(rxrpc_kernel_abort_call);
857
858/**
859 * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
860 * @sock: The socket the call is on
861 * @call: The call to be informed
862 * @tx_total_len: The amount of data to be transmitted for this call
863 *
864 * Allow a kernel service to set the total transmit length on a call.  This
865 * allows buffer-to-packet encrypt-and-copy to be performed.
866 *
867 * This function is primarily for use for setting the reply length since the
868 * request length can be set when beginning the call.
869 */
870void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
871				s64 tx_total_len)
872{
873	WARN_ON(call->tx_total_len != -1);
874	call->tx_total_len = tx_total_len;
875}
876EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);