xref: /linux/net/rxrpc/sendmsg.c (revision 08f3e0873ac203449465c2b8473d684e2f9f41d1)
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  * Return true if there's sufficient Tx queue space.
22  */
23 static bool rxrpc_check_tx_space(struct rxrpc_call *call, rxrpc_seq_t *_tx_win)
24 {
25 	unsigned int win_size =
26 		min_t(unsigned int, call->tx_winsize,
27 		      call->cong_cwnd + call->cong_extra);
28 	rxrpc_seq_t tx_win = READ_ONCE(call->tx_hard_ack);
29 
30 	if (_tx_win)
31 		*_tx_win = tx_win;
32 	return call->tx_top - tx_win < win_size;
33 }
34 
35 /*
36  * Wait for space to appear in the Tx queue or a signal to occur.
37  */
38 static int rxrpc_wait_for_tx_window_intr(struct rxrpc_sock *rx,
39 					 struct rxrpc_call *call,
40 					 long *timeo)
41 {
42 	for (;;) {
43 		set_current_state(TASK_INTERRUPTIBLE);
44 		if (rxrpc_check_tx_space(call, NULL))
45 			return 0;
46 
47 		if (call->state >= RXRPC_CALL_COMPLETE)
48 			return call->error;
49 
50 		if (signal_pending(current))
51 			return sock_intr_errno(*timeo);
52 
53 		trace_rxrpc_transmit(call, rxrpc_transmit_wait);
54 		mutex_unlock(&call->user_mutex);
55 		*timeo = schedule_timeout(*timeo);
56 		if (mutex_lock_interruptible(&call->user_mutex) < 0)
57 			return sock_intr_errno(*timeo);
58 	}
59 }
60 
61 /*
62  * Wait for space to appear in the Tx queue uninterruptibly, but with
63  * a timeout of 2*RTT if no progress was made and a signal occurred.
64  */
65 static int rxrpc_wait_for_tx_window_waitall(struct rxrpc_sock *rx,
66 					    struct rxrpc_call *call)
67 {
68 	rxrpc_seq_t tx_start, tx_win;
69 	signed long rtt, timeout;
70 
71 	rtt = READ_ONCE(call->peer->srtt_us) >> 3;
72 	rtt = usecs_to_jiffies(rtt) * 2;
73 	if (rtt < 2)
74 		rtt = 2;
75 
76 	timeout = rtt;
77 	tx_start = READ_ONCE(call->tx_hard_ack);
78 
79 	for (;;) {
80 		set_current_state(TASK_UNINTERRUPTIBLE);
81 
82 		tx_win = READ_ONCE(call->tx_hard_ack);
83 		if (rxrpc_check_tx_space(call, &tx_win))
84 			return 0;
85 
86 		if (call->state >= RXRPC_CALL_COMPLETE)
87 			return call->error;
88 
89 		if (timeout == 0 &&
90 		    tx_win == tx_start && signal_pending(current))
91 			return -EINTR;
92 
93 		if (tx_win != tx_start) {
94 			timeout = rtt;
95 			tx_start = tx_win;
96 		}
97 
98 		trace_rxrpc_transmit(call, rxrpc_transmit_wait);
99 		timeout = schedule_timeout(timeout);
100 	}
101 }
102 
103 /*
104  * Wait for space to appear in the Tx queue uninterruptibly.
105  */
106 static int rxrpc_wait_for_tx_window_nonintr(struct rxrpc_sock *rx,
107 					    struct rxrpc_call *call,
108 					    long *timeo)
109 {
110 	for (;;) {
111 		set_current_state(TASK_UNINTERRUPTIBLE);
112 		if (rxrpc_check_tx_space(call, NULL))
113 			return 0;
114 
115 		if (call->state >= RXRPC_CALL_COMPLETE)
116 			return call->error;
117 
118 		trace_rxrpc_transmit(call, rxrpc_transmit_wait);
119 		*timeo = schedule_timeout(*timeo);
120 	}
121 }
122 
123 /*
124  * wait for space to appear in the transmit/ACK window
125  * - caller holds the socket locked
126  */
127 static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
128 				    struct rxrpc_call *call,
129 				    long *timeo,
130 				    bool waitall)
131 {
132 	DECLARE_WAITQUEUE(myself, current);
133 	int ret;
134 
135 	_enter(",{%u,%u,%u}",
136 	       call->tx_hard_ack, call->tx_top, call->tx_winsize);
137 
138 	add_wait_queue(&call->waitq, &myself);
139 
140 	switch (call->interruptibility) {
141 	case RXRPC_INTERRUPTIBLE:
142 		if (waitall)
143 			ret = rxrpc_wait_for_tx_window_waitall(rx, call);
144 		else
145 			ret = rxrpc_wait_for_tx_window_intr(rx, call, timeo);
146 		break;
147 	case RXRPC_PREINTERRUPTIBLE:
148 	case RXRPC_UNINTERRUPTIBLE:
149 	default:
150 		ret = rxrpc_wait_for_tx_window_nonintr(rx, call, timeo);
151 		break;
152 	}
153 
154 	remove_wait_queue(&call->waitq, &myself);
155 	set_current_state(TASK_RUNNING);
156 	_leave(" = %d", ret);
157 	return ret;
158 }
159 
160 /*
161  * Schedule an instant Tx resend.
162  */
163 static inline void rxrpc_instant_resend(struct rxrpc_call *call, int ix)
164 {
165 	spin_lock_bh(&call->lock);
166 
167 	if (call->state < RXRPC_CALL_COMPLETE) {
168 		call->rxtx_annotations[ix] =
169 			(call->rxtx_annotations[ix] & RXRPC_TX_ANNO_LAST) |
170 			RXRPC_TX_ANNO_RETRANS;
171 		if (!test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
172 			rxrpc_queue_call(call);
173 	}
174 
175 	spin_unlock_bh(&call->lock);
176 }
177 
178 /*
179  * Notify the owner of the call that the transmit phase is ended and the last
180  * packet has been queued.
181  */
182 static void rxrpc_notify_end_tx(struct rxrpc_sock *rx, struct rxrpc_call *call,
183 				rxrpc_notify_end_tx_t notify_end_tx)
184 {
185 	if (notify_end_tx)
186 		notify_end_tx(&rx->sk, call, call->user_call_ID);
187 }
188 
189 /*
190  * Queue a DATA packet for transmission, set the resend timeout and send
191  * the packet immediately.  Returns the error from rxrpc_send_data_packet()
192  * in case the caller wants to do something with it.
193  */
194 static int rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
195 			      struct sk_buff *skb, bool last,
196 			      rxrpc_notify_end_tx_t notify_end_tx)
197 {
198 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
199 	unsigned long now;
200 	rxrpc_seq_t seq = sp->hdr.seq;
201 	int ret, ix;
202 	u8 annotation = RXRPC_TX_ANNO_UNACK;
203 
204 	_net("queue skb %p [%d]", skb, seq);
205 
206 	ASSERTCMP(seq, ==, call->tx_top + 1);
207 
208 	if (last)
209 		annotation |= RXRPC_TX_ANNO_LAST;
210 
211 	/* We have to set the timestamp before queueing as the retransmit
212 	 * algorithm can see the packet as soon as we queue it.
213 	 */
214 	skb->tstamp = ktime_get_real();
215 
216 	ix = seq & RXRPC_RXTX_BUFF_MASK;
217 	rxrpc_get_skb(skb, rxrpc_skb_got);
218 	call->rxtx_annotations[ix] = annotation;
219 	smp_wmb();
220 	call->rxtx_buffer[ix] = skb;
221 	call->tx_top = seq;
222 	if (last)
223 		trace_rxrpc_transmit(call, rxrpc_transmit_queue_last);
224 	else
225 		trace_rxrpc_transmit(call, rxrpc_transmit_queue);
226 
227 	if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {
228 		_debug("________awaiting reply/ACK__________");
229 		write_lock_bh(&call->state_lock);
230 		switch (call->state) {
231 		case RXRPC_CALL_CLIENT_SEND_REQUEST:
232 			call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
233 			rxrpc_notify_end_tx(rx, call, notify_end_tx);
234 			break;
235 		case RXRPC_CALL_SERVER_ACK_REQUEST:
236 			call->state = RXRPC_CALL_SERVER_SEND_REPLY;
237 			now = jiffies;
238 			WRITE_ONCE(call->ack_at, now + MAX_JIFFY_OFFSET);
239 			if (call->ackr_reason == RXRPC_ACK_DELAY)
240 				call->ackr_reason = 0;
241 			trace_rxrpc_timer(call, rxrpc_timer_init_for_send_reply, now);
242 			if (!last)
243 				break;
244 			fallthrough;
245 		case RXRPC_CALL_SERVER_SEND_REPLY:
246 			call->state = RXRPC_CALL_SERVER_AWAIT_ACK;
247 			rxrpc_notify_end_tx(rx, call, notify_end_tx);
248 			break;
249 		default:
250 			break;
251 		}
252 		write_unlock_bh(&call->state_lock);
253 	}
254 
255 	if (seq == 1 && rxrpc_is_client_call(call))
256 		rxrpc_expose_client_call(call);
257 
258 	ret = rxrpc_send_data_packet(call, skb, false);
259 	if (ret < 0) {
260 		switch (ret) {
261 		case -ENETUNREACH:
262 		case -EHOSTUNREACH:
263 		case -ECONNREFUSED:
264 			rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
265 						  0, ret);
266 			goto out;
267 		}
268 		_debug("need instant resend %d", ret);
269 		rxrpc_instant_resend(call, ix);
270 	} else {
271 		unsigned long now = jiffies;
272 		unsigned long resend_at = now + call->peer->rto_j;
273 
274 		WRITE_ONCE(call->resend_at, resend_at);
275 		rxrpc_reduce_call_timer(call, resend_at, now,
276 					rxrpc_timer_set_for_send);
277 	}
278 
279 out:
280 	rxrpc_free_skb(skb, rxrpc_skb_freed);
281 	_leave(" = %d", ret);
282 	return ret;
283 }
284 
285 /*
286  * send data through a socket
287  * - must be called in process context
288  * - The caller holds the call user access mutex, but not the socket lock.
289  */
290 static int rxrpc_send_data(struct rxrpc_sock *rx,
291 			   struct rxrpc_call *call,
292 			   struct msghdr *msg, size_t len,
293 			   rxrpc_notify_end_tx_t notify_end_tx)
294 {
295 	struct rxrpc_skb_priv *sp;
296 	struct sk_buff *skb;
297 	struct sock *sk = &rx->sk;
298 	long timeo;
299 	bool more;
300 	int ret, copied;
301 
302 	timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
303 
304 	/* this should be in poll */
305 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
306 
307 	if (sk->sk_shutdown & SEND_SHUTDOWN)
308 		return -EPIPE;
309 
310 	more = msg->msg_flags & MSG_MORE;
311 
312 	if (call->tx_total_len != -1) {
313 		if (len > call->tx_total_len)
314 			return -EMSGSIZE;
315 		if (!more && len != call->tx_total_len)
316 			return -EMSGSIZE;
317 	}
318 
319 	skb = call->tx_pending;
320 	call->tx_pending = NULL;
321 	rxrpc_see_skb(skb, rxrpc_skb_seen);
322 
323 	copied = 0;
324 	do {
325 		/* Check to see if there's a ping ACK to reply to. */
326 		if (call->ackr_reason == RXRPC_ACK_PING_RESPONSE)
327 			rxrpc_send_ack_packet(call, false, NULL);
328 
329 		if (!skb) {
330 			size_t remain, bufsize, chunk, offset;
331 
332 			_debug("alloc");
333 
334 			if (!rxrpc_check_tx_space(call, NULL)) {
335 				ret = -EAGAIN;
336 				if (msg->msg_flags & MSG_DONTWAIT)
337 					goto maybe_error;
338 				ret = rxrpc_wait_for_tx_window(rx, call,
339 							       &timeo,
340 							       msg->msg_flags & MSG_WAITALL);
341 				if (ret < 0)
342 					goto maybe_error;
343 			}
344 
345 			/* Work out the maximum size of a packet.  Assume that
346 			 * the security header is going to be in the padded
347 			 * region (enc blocksize), but the trailer is not.
348 			 */
349 			remain = more ? INT_MAX : msg_data_left(msg);
350 			ret = call->conn->security->how_much_data(call, remain,
351 								  &bufsize, &chunk, &offset);
352 			if (ret < 0)
353 				goto maybe_error;
354 
355 			_debug("SIZE: %zu/%zu @%zu", chunk, bufsize, offset);
356 
357 			/* create a buffer that we can retain until it's ACK'd */
358 			skb = sock_alloc_send_skb(
359 				sk, bufsize, msg->msg_flags & MSG_DONTWAIT, &ret);
360 			if (!skb)
361 				goto maybe_error;
362 
363 			sp = rxrpc_skb(skb);
364 			sp->rx_flags |= RXRPC_SKB_TX_BUFFER;
365 			rxrpc_new_skb(skb, rxrpc_skb_new);
366 
367 			_debug("ALLOC SEND %p", skb);
368 
369 			ASSERTCMP(skb->mark, ==, 0);
370 
371 			__skb_put(skb, offset);
372 
373 			sp->remain = chunk;
374 			if (sp->remain > skb_tailroom(skb))
375 				sp->remain = skb_tailroom(skb);
376 
377 			_net("skb: hr %d, tr %d, hl %d, rm %d",
378 			       skb_headroom(skb),
379 			       skb_tailroom(skb),
380 			       skb_headlen(skb),
381 			       sp->remain);
382 
383 			skb->ip_summed = CHECKSUM_UNNECESSARY;
384 		}
385 
386 		_debug("append");
387 		sp = rxrpc_skb(skb);
388 
389 		/* append next segment of data to the current buffer */
390 		if (msg_data_left(msg) > 0) {
391 			int copy = skb_tailroom(skb);
392 			ASSERTCMP(copy, >, 0);
393 			if (copy > msg_data_left(msg))
394 				copy = msg_data_left(msg);
395 			if (copy > sp->remain)
396 				copy = sp->remain;
397 
398 			_debug("add");
399 			ret = skb_add_data(skb, &msg->msg_iter, copy);
400 			_debug("added");
401 			if (ret < 0)
402 				goto efault;
403 			sp->remain -= copy;
404 			skb->mark += copy;
405 			copied += copy;
406 			if (call->tx_total_len != -1)
407 				call->tx_total_len -= copy;
408 		}
409 
410 		/* check for the far side aborting the call or a network error
411 		 * occurring */
412 		if (call->state == RXRPC_CALL_COMPLETE)
413 			goto call_terminated;
414 
415 		/* add the packet to the send queue if it's now full */
416 		if (sp->remain <= 0 ||
417 		    (msg_data_left(msg) == 0 && !more)) {
418 			struct rxrpc_connection *conn = call->conn;
419 			uint32_t seq;
420 
421 			seq = call->tx_top + 1;
422 
423 			sp->hdr.seq	= seq;
424 			sp->hdr._rsvd	= 0;
425 			sp->hdr.flags	= conn->out_clientflag;
426 
427 			if (msg_data_left(msg) == 0 && !more)
428 				sp->hdr.flags |= RXRPC_LAST_PACKET;
429 			else if (call->tx_top - call->tx_hard_ack <
430 				 call->tx_winsize)
431 				sp->hdr.flags |= RXRPC_MORE_PACKETS;
432 
433 			ret = call->security->secure_packet(call, skb, skb->mark);
434 			if (ret < 0)
435 				goto out;
436 
437 			ret = rxrpc_queue_packet(rx, call, skb,
438 						 !msg_data_left(msg) && !more,
439 						 notify_end_tx);
440 			/* Should check for failure here */
441 			skb = NULL;
442 		}
443 	} while (msg_data_left(msg) > 0);
444 
445 success:
446 	ret = copied;
447 out:
448 	call->tx_pending = skb;
449 	_leave(" = %d", ret);
450 	return ret;
451 
452 call_terminated:
453 	rxrpc_free_skb(skb, rxrpc_skb_freed);
454 	_leave(" = %d", call->error);
455 	return call->error;
456 
457 maybe_error:
458 	if (copied)
459 		goto success;
460 	goto out;
461 
462 efault:
463 	ret = -EFAULT;
464 	goto out;
465 }
466 
467 /*
468  * extract control messages from the sendmsg() control buffer
469  */
470 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
471 {
472 	struct cmsghdr *cmsg;
473 	bool got_user_ID = false;
474 	int len;
475 
476 	if (msg->msg_controllen == 0)
477 		return -EINVAL;
478 
479 	for_each_cmsghdr(cmsg, msg) {
480 		if (!CMSG_OK(msg, cmsg))
481 			return -EINVAL;
482 
483 		len = cmsg->cmsg_len - sizeof(struct cmsghdr);
484 		_debug("CMSG %d, %d, %d",
485 		       cmsg->cmsg_level, cmsg->cmsg_type, len);
486 
487 		if (cmsg->cmsg_level != SOL_RXRPC)
488 			continue;
489 
490 		switch (cmsg->cmsg_type) {
491 		case RXRPC_USER_CALL_ID:
492 			if (msg->msg_flags & MSG_CMSG_COMPAT) {
493 				if (len != sizeof(u32))
494 					return -EINVAL;
495 				p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
496 			} else {
497 				if (len != sizeof(unsigned long))
498 					return -EINVAL;
499 				p->call.user_call_ID = *(unsigned long *)
500 					CMSG_DATA(cmsg);
501 			}
502 			got_user_ID = true;
503 			break;
504 
505 		case RXRPC_ABORT:
506 			if (p->command != RXRPC_CMD_SEND_DATA)
507 				return -EINVAL;
508 			p->command = RXRPC_CMD_SEND_ABORT;
509 			if (len != sizeof(p->abort_code))
510 				return -EINVAL;
511 			p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
512 			if (p->abort_code == 0)
513 				return -EINVAL;
514 			break;
515 
516 		case RXRPC_CHARGE_ACCEPT:
517 			if (p->command != RXRPC_CMD_SEND_DATA)
518 				return -EINVAL;
519 			p->command = RXRPC_CMD_CHARGE_ACCEPT;
520 			if (len != 0)
521 				return -EINVAL;
522 			break;
523 
524 		case RXRPC_EXCLUSIVE_CALL:
525 			p->exclusive = true;
526 			if (len != 0)
527 				return -EINVAL;
528 			break;
529 
530 		case RXRPC_UPGRADE_SERVICE:
531 			p->upgrade = true;
532 			if (len != 0)
533 				return -EINVAL;
534 			break;
535 
536 		case RXRPC_TX_LENGTH:
537 			if (p->call.tx_total_len != -1 || len != sizeof(__s64))
538 				return -EINVAL;
539 			p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
540 			if (p->call.tx_total_len < 0)
541 				return -EINVAL;
542 			break;
543 
544 		case RXRPC_SET_CALL_TIMEOUT:
545 			if (len & 3 || len < 4 || len > 12)
546 				return -EINVAL;
547 			memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
548 			p->call.nr_timeouts = len / 4;
549 			if (p->call.timeouts.hard > INT_MAX / HZ)
550 				return -ERANGE;
551 			if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
552 				return -ERANGE;
553 			if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
554 				return -ERANGE;
555 			break;
556 
557 		default:
558 			return -EINVAL;
559 		}
560 	}
561 
562 	if (!got_user_ID)
563 		return -EINVAL;
564 	if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
565 		return -EINVAL;
566 	_leave(" = 0");
567 	return 0;
568 }
569 
570 /*
571  * Create a new client call for sendmsg().
572  * - Called with the socket lock held, which it must release.
573  * - If it returns a call, the call's lock will need releasing by the caller.
574  */
575 static struct rxrpc_call *
576 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
577 				  struct rxrpc_send_params *p)
578 	__releases(&rx->sk.sk_lock.slock)
579 	__acquires(&call->user_mutex)
580 {
581 	struct rxrpc_conn_parameters cp;
582 	struct rxrpc_call *call;
583 	struct key *key;
584 
585 	DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
586 
587 	_enter("");
588 
589 	if (!msg->msg_name) {
590 		release_sock(&rx->sk);
591 		return ERR_PTR(-EDESTADDRREQ);
592 	}
593 
594 	key = rx->key;
595 	if (key && !rx->key->payload.data[0])
596 		key = NULL;
597 
598 	memset(&cp, 0, sizeof(cp));
599 	cp.local		= rx->local;
600 	cp.key			= rx->key;
601 	cp.security_level	= rx->min_sec_level;
602 	cp.exclusive		= rx->exclusive | p->exclusive;
603 	cp.upgrade		= p->upgrade;
604 	cp.service_id		= srx->srx_service;
605 	call = rxrpc_new_client_call(rx, &cp, srx, &p->call, GFP_KERNEL,
606 				     atomic_inc_return(&rxrpc_debug_id));
607 	/* The socket is now unlocked */
608 
609 	rxrpc_put_peer(cp.peer);
610 	_leave(" = %p\n", call);
611 	return call;
612 }
613 
614 /*
615  * send a message forming part of a client call through an RxRPC socket
616  * - caller holds the socket locked
617  * - the socket may be either a client socket or a server socket
618  */
619 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
620 	__releases(&rx->sk.sk_lock.slock)
621 	__releases(&call->user_mutex)
622 {
623 	enum rxrpc_call_state state;
624 	struct rxrpc_call *call;
625 	unsigned long now, j;
626 	int ret;
627 
628 	struct rxrpc_send_params p = {
629 		.call.tx_total_len	= -1,
630 		.call.user_call_ID	= 0,
631 		.call.nr_timeouts	= 0,
632 		.call.interruptibility	= RXRPC_INTERRUPTIBLE,
633 		.abort_code		= 0,
634 		.command		= RXRPC_CMD_SEND_DATA,
635 		.exclusive		= false,
636 		.upgrade		= false,
637 	};
638 
639 	_enter("");
640 
641 	ret = rxrpc_sendmsg_cmsg(msg, &p);
642 	if (ret < 0)
643 		goto error_release_sock;
644 
645 	if (p.command == RXRPC_CMD_CHARGE_ACCEPT) {
646 		ret = -EINVAL;
647 		if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
648 			goto error_release_sock;
649 		ret = rxrpc_user_charge_accept(rx, p.call.user_call_ID);
650 		goto error_release_sock;
651 	}
652 
653 	call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
654 	if (!call) {
655 		ret = -EBADSLT;
656 		if (p.command != RXRPC_CMD_SEND_DATA)
657 			goto error_release_sock;
658 		call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
659 		/* The socket is now unlocked... */
660 		if (IS_ERR(call))
661 			return PTR_ERR(call);
662 		/* ... and we have the call lock. */
663 		ret = 0;
664 		if (READ_ONCE(call->state) == RXRPC_CALL_COMPLETE)
665 			goto out_put_unlock;
666 	} else {
667 		switch (READ_ONCE(call->state)) {
668 		case RXRPC_CALL_UNINITIALISED:
669 		case RXRPC_CALL_CLIENT_AWAIT_CONN:
670 		case RXRPC_CALL_SERVER_PREALLOC:
671 		case RXRPC_CALL_SERVER_SECURING:
672 			rxrpc_put_call(call, rxrpc_call_put);
673 			ret = -EBUSY;
674 			goto error_release_sock;
675 		default:
676 			break;
677 		}
678 
679 		ret = mutex_lock_interruptible(&call->user_mutex);
680 		release_sock(&rx->sk);
681 		if (ret < 0) {
682 			ret = -ERESTARTSYS;
683 			goto error_put;
684 		}
685 
686 		if (p.call.tx_total_len != -1) {
687 			ret = -EINVAL;
688 			if (call->tx_total_len != -1 ||
689 			    call->tx_pending ||
690 			    call->tx_top != 0)
691 				goto error_put;
692 			call->tx_total_len = p.call.tx_total_len;
693 		}
694 	}
695 
696 	switch (p.call.nr_timeouts) {
697 	case 3:
698 		j = msecs_to_jiffies(p.call.timeouts.normal);
699 		if (p.call.timeouts.normal > 0 && j == 0)
700 			j = 1;
701 		WRITE_ONCE(call->next_rx_timo, j);
702 		fallthrough;
703 	case 2:
704 		j = msecs_to_jiffies(p.call.timeouts.idle);
705 		if (p.call.timeouts.idle > 0 && j == 0)
706 			j = 1;
707 		WRITE_ONCE(call->next_req_timo, j);
708 		fallthrough;
709 	case 1:
710 		if (p.call.timeouts.hard > 0) {
711 			j = msecs_to_jiffies(p.call.timeouts.hard);
712 			now = jiffies;
713 			j += now;
714 			WRITE_ONCE(call->expect_term_by, j);
715 			rxrpc_reduce_call_timer(call, j, now,
716 						rxrpc_timer_set_for_hard);
717 		}
718 		break;
719 	}
720 
721 	state = READ_ONCE(call->state);
722 	_debug("CALL %d USR %lx ST %d on CONN %p",
723 	       call->debug_id, call->user_call_ID, state, call->conn);
724 
725 	if (state >= RXRPC_CALL_COMPLETE) {
726 		/* it's too late for this call */
727 		ret = -ESHUTDOWN;
728 	} else if (p.command == RXRPC_CMD_SEND_ABORT) {
729 		ret = 0;
730 		if (rxrpc_abort_call("CMD", call, 0, p.abort_code, -ECONNABORTED))
731 			ret = rxrpc_send_abort_packet(call);
732 	} else if (p.command != RXRPC_CMD_SEND_DATA) {
733 		ret = -EINVAL;
734 	} else if (rxrpc_is_client_call(call) &&
735 		   state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
736 		/* request phase complete for this client call */
737 		ret = -EPROTO;
738 	} else if (rxrpc_is_service_call(call) &&
739 		   state != RXRPC_CALL_SERVER_ACK_REQUEST &&
740 		   state != RXRPC_CALL_SERVER_SEND_REPLY) {
741 		/* Reply phase not begun or not complete for service call. */
742 		ret = -EPROTO;
743 	} else {
744 		ret = rxrpc_send_data(rx, call, msg, len, NULL);
745 	}
746 
747 out_put_unlock:
748 	mutex_unlock(&call->user_mutex);
749 error_put:
750 	rxrpc_put_call(call, rxrpc_call_put);
751 	_leave(" = %d", ret);
752 	return ret;
753 
754 error_release_sock:
755 	release_sock(&rx->sk);
756 	return ret;
757 }
758 
759 /**
760  * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
761  * @sock: The socket the call is on
762  * @call: The call to send data through
763  * @msg: The data to send
764  * @len: The amount of data to send
765  * @notify_end_tx: Notification that the last packet is queued.
766  *
767  * Allow a kernel service to send data on a call.  The call must be in an state
768  * appropriate to sending data.  No control data should be supplied in @msg,
769  * nor should an address be supplied.  MSG_MORE should be flagged if there's
770  * more data to come, otherwise this data will end the transmission phase.
771  */
772 int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
773 			   struct msghdr *msg, size_t len,
774 			   rxrpc_notify_end_tx_t notify_end_tx)
775 {
776 	int ret;
777 
778 	_enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
779 
780 	ASSERTCMP(msg->msg_name, ==, NULL);
781 	ASSERTCMP(msg->msg_control, ==, NULL);
782 
783 	mutex_lock(&call->user_mutex);
784 
785 	_debug("CALL %d USR %lx ST %d on CONN %p",
786 	       call->debug_id, call->user_call_ID, call->state, call->conn);
787 
788 	switch (READ_ONCE(call->state)) {
789 	case RXRPC_CALL_CLIENT_SEND_REQUEST:
790 	case RXRPC_CALL_SERVER_ACK_REQUEST:
791 	case RXRPC_CALL_SERVER_SEND_REPLY:
792 		ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
793 				      notify_end_tx);
794 		break;
795 	case RXRPC_CALL_COMPLETE:
796 		read_lock_bh(&call->state_lock);
797 		ret = call->error;
798 		read_unlock_bh(&call->state_lock);
799 		break;
800 	default:
801 		/* Request phase complete for this client call */
802 		trace_rxrpc_rx_eproto(call, 0, tracepoint_string("late_send"));
803 		ret = -EPROTO;
804 		break;
805 	}
806 
807 	mutex_unlock(&call->user_mutex);
808 	_leave(" = %d", ret);
809 	return ret;
810 }
811 EXPORT_SYMBOL(rxrpc_kernel_send_data);
812 
813 /**
814  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
815  * @sock: The socket the call is on
816  * @call: The call to be aborted
817  * @abort_code: The abort code to stick into the ABORT packet
818  * @error: Local error value
819  * @why: 3-char string indicating why.
820  *
821  * Allow a kernel service to abort a call, if it's still in an abortable state
822  * and return true if the call was aborted, false if it was already complete.
823  */
824 bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
825 			     u32 abort_code, int error, const char *why)
826 {
827 	bool aborted;
828 
829 	_enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
830 
831 	mutex_lock(&call->user_mutex);
832 
833 	aborted = rxrpc_abort_call(why, call, 0, abort_code, error);
834 	if (aborted)
835 		rxrpc_send_abort_packet(call);
836 
837 	mutex_unlock(&call->user_mutex);
838 	return aborted;
839 }
840 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
841 
842 /**
843  * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
844  * @sock: The socket the call is on
845  * @call: The call to be informed
846  * @tx_total_len: The amount of data to be transmitted for this call
847  *
848  * Allow a kernel service to set the total transmit length on a call.  This
849  * allows buffer-to-packet encrypt-and-copy to be performed.
850  *
851  * This function is primarily for use for setting the reply length since the
852  * request length can be set when beginning the call.
853  */
854 void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
855 				s64 tx_total_len)
856 {
857 	WARN_ON(call->tx_total_len != -1);
858 	call->tx_total_len = tx_total_len;
859 }
860 EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);
861