xref: /openbmc/linux/net/rxrpc/sendmsg.c (revision 9aab6601)
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 size, chunk, max, space;
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 			max = RXRPC_JUMBO_DATALEN;
346 			max -= call->conn->security_size;
347 			max &= ~(call->conn->size_align - 1UL);
348 
349 			chunk = max;
350 			if (chunk > msg_data_left(msg) && !more)
351 				chunk = msg_data_left(msg);
352 
353 			space = chunk + call->conn->size_align;
354 			space &= ~(call->conn->size_align - 1UL);
355 
356 			size = space + call->conn->security_size;
357 
358 			_debug("SIZE: %zu/%zu/%zu", chunk, space, size);
359 
360 			/* create a buffer that we can retain until it's ACK'd */
361 			skb = sock_alloc_send_skb(
362 				sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
363 			if (!skb)
364 				goto maybe_error;
365 
366 			sp = rxrpc_skb(skb);
367 			sp->rx_flags |= RXRPC_SKB_TX_BUFFER;
368 			rxrpc_new_skb(skb, rxrpc_skb_new);
369 
370 			_debug("ALLOC SEND %p", skb);
371 
372 			ASSERTCMP(skb->mark, ==, 0);
373 
374 			_debug("HS: %u", call->conn->security_size);
375 			skb_reserve(skb, call->conn->security_size);
376 			skb->len += call->conn->security_size;
377 
378 			sp->remain = chunk;
379 			if (sp->remain > skb_tailroom(skb))
380 				sp->remain = skb_tailroom(skb);
381 
382 			_net("skb: hr %d, tr %d, hl %d, rm %d",
383 			       skb_headroom(skb),
384 			       skb_tailroom(skb),
385 			       skb_headlen(skb),
386 			       sp->remain);
387 
388 			skb->ip_summed = CHECKSUM_UNNECESSARY;
389 		}
390 
391 		_debug("append");
392 		sp = rxrpc_skb(skb);
393 
394 		/* append next segment of data to the current buffer */
395 		if (msg_data_left(msg) > 0) {
396 			int copy = skb_tailroom(skb);
397 			ASSERTCMP(copy, >, 0);
398 			if (copy > msg_data_left(msg))
399 				copy = msg_data_left(msg);
400 			if (copy > sp->remain)
401 				copy = sp->remain;
402 
403 			_debug("add");
404 			ret = skb_add_data(skb, &msg->msg_iter, copy);
405 			_debug("added");
406 			if (ret < 0)
407 				goto efault;
408 			sp->remain -= copy;
409 			skb->mark += copy;
410 			copied += copy;
411 			if (call->tx_total_len != -1)
412 				call->tx_total_len -= copy;
413 		}
414 
415 		/* check for the far side aborting the call or a network error
416 		 * occurring */
417 		if (call->state == RXRPC_CALL_COMPLETE)
418 			goto call_terminated;
419 
420 		/* add the packet to the send queue if it's now full */
421 		if (sp->remain <= 0 ||
422 		    (msg_data_left(msg) == 0 && !more)) {
423 			struct rxrpc_connection *conn = call->conn;
424 			uint32_t seq;
425 			size_t pad;
426 
427 			/* pad out if we're using security */
428 			if (conn->security_ix) {
429 				pad = conn->security_size + skb->mark;
430 				pad = conn->size_align - pad;
431 				pad &= conn->size_align - 1;
432 				_debug("pad %zu", pad);
433 				if (pad)
434 					skb_put_zero(skb, pad);
435 			}
436 
437 			seq = call->tx_top + 1;
438 
439 			sp->hdr.seq	= seq;
440 			sp->hdr._rsvd	= 0;
441 			sp->hdr.flags	= conn->out_clientflag;
442 
443 			if (msg_data_left(msg) == 0 && !more)
444 				sp->hdr.flags |= RXRPC_LAST_PACKET;
445 			else if (call->tx_top - call->tx_hard_ack <
446 				 call->tx_winsize)
447 				sp->hdr.flags |= RXRPC_MORE_PACKETS;
448 
449 			ret = call->security->secure_packet(
450 				call, skb, skb->mark, skb->head);
451 			if (ret < 0)
452 				goto out;
453 
454 			ret = rxrpc_queue_packet(rx, call, skb,
455 						 !msg_data_left(msg) && !more,
456 						 notify_end_tx);
457 			/* Should check for failure here */
458 			skb = NULL;
459 		}
460 	} while (msg_data_left(msg) > 0);
461 
462 success:
463 	ret = copied;
464 out:
465 	call->tx_pending = skb;
466 	_leave(" = %d", ret);
467 	return ret;
468 
469 call_terminated:
470 	rxrpc_free_skb(skb, rxrpc_skb_freed);
471 	_leave(" = %d", call->error);
472 	return call->error;
473 
474 maybe_error:
475 	if (copied)
476 		goto success;
477 	goto out;
478 
479 efault:
480 	ret = -EFAULT;
481 	goto out;
482 }
483 
484 /*
485  * extract control messages from the sendmsg() control buffer
486  */
487 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
488 {
489 	struct cmsghdr *cmsg;
490 	bool got_user_ID = false;
491 	int len;
492 
493 	if (msg->msg_controllen == 0)
494 		return -EINVAL;
495 
496 	for_each_cmsghdr(cmsg, msg) {
497 		if (!CMSG_OK(msg, cmsg))
498 			return -EINVAL;
499 
500 		len = cmsg->cmsg_len - sizeof(struct cmsghdr);
501 		_debug("CMSG %d, %d, %d",
502 		       cmsg->cmsg_level, cmsg->cmsg_type, len);
503 
504 		if (cmsg->cmsg_level != SOL_RXRPC)
505 			continue;
506 
507 		switch (cmsg->cmsg_type) {
508 		case RXRPC_USER_CALL_ID:
509 			if (msg->msg_flags & MSG_CMSG_COMPAT) {
510 				if (len != sizeof(u32))
511 					return -EINVAL;
512 				p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
513 			} else {
514 				if (len != sizeof(unsigned long))
515 					return -EINVAL;
516 				p->call.user_call_ID = *(unsigned long *)
517 					CMSG_DATA(cmsg);
518 			}
519 			got_user_ID = true;
520 			break;
521 
522 		case RXRPC_ABORT:
523 			if (p->command != RXRPC_CMD_SEND_DATA)
524 				return -EINVAL;
525 			p->command = RXRPC_CMD_SEND_ABORT;
526 			if (len != sizeof(p->abort_code))
527 				return -EINVAL;
528 			p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
529 			if (p->abort_code == 0)
530 				return -EINVAL;
531 			break;
532 
533 		case RXRPC_ACCEPT:
534 			if (p->command != RXRPC_CMD_SEND_DATA)
535 				return -EINVAL;
536 			p->command = RXRPC_CMD_ACCEPT;
537 			if (len != 0)
538 				return -EINVAL;
539 			break;
540 
541 		case RXRPC_EXCLUSIVE_CALL:
542 			p->exclusive = true;
543 			if (len != 0)
544 				return -EINVAL;
545 			break;
546 
547 		case RXRPC_UPGRADE_SERVICE:
548 			p->upgrade = true;
549 			if (len != 0)
550 				return -EINVAL;
551 			break;
552 
553 		case RXRPC_TX_LENGTH:
554 			if (p->call.tx_total_len != -1 || len != sizeof(__s64))
555 				return -EINVAL;
556 			p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
557 			if (p->call.tx_total_len < 0)
558 				return -EINVAL;
559 			break;
560 
561 		case RXRPC_SET_CALL_TIMEOUT:
562 			if (len & 3 || len < 4 || len > 12)
563 				return -EINVAL;
564 			memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
565 			p->call.nr_timeouts = len / 4;
566 			if (p->call.timeouts.hard > INT_MAX / HZ)
567 				return -ERANGE;
568 			if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
569 				return -ERANGE;
570 			if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
571 				return -ERANGE;
572 			break;
573 
574 		default:
575 			return -EINVAL;
576 		}
577 	}
578 
579 	if (!got_user_ID)
580 		return -EINVAL;
581 	if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
582 		return -EINVAL;
583 	_leave(" = 0");
584 	return 0;
585 }
586 
587 /*
588  * Create a new client call for sendmsg().
589  * - Called with the socket lock held, which it must release.
590  * - If it returns a call, the call's lock will need releasing by the caller.
591  */
592 static struct rxrpc_call *
593 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
594 				  struct rxrpc_send_params *p)
595 	__releases(&rx->sk.sk_lock.slock)
596 	__acquires(&call->user_mutex)
597 {
598 	struct rxrpc_conn_parameters cp;
599 	struct rxrpc_call *call;
600 	struct key *key;
601 
602 	DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
603 
604 	_enter("");
605 
606 	if (!msg->msg_name) {
607 		release_sock(&rx->sk);
608 		return ERR_PTR(-EDESTADDRREQ);
609 	}
610 
611 	key = rx->key;
612 	if (key && !rx->key->payload.data[0])
613 		key = NULL;
614 
615 	memset(&cp, 0, sizeof(cp));
616 	cp.local		= rx->local;
617 	cp.key			= rx->key;
618 	cp.security_level	= rx->min_sec_level;
619 	cp.exclusive		= rx->exclusive | p->exclusive;
620 	cp.upgrade		= p->upgrade;
621 	cp.service_id		= srx->srx_service;
622 	call = rxrpc_new_client_call(rx, &cp, srx, &p->call, GFP_KERNEL,
623 				     atomic_inc_return(&rxrpc_debug_id));
624 	/* The socket is now unlocked */
625 
626 	rxrpc_put_peer(cp.peer);
627 	_leave(" = %p\n", call);
628 	return call;
629 }
630 
631 /*
632  * send a message forming part of a client call through an RxRPC socket
633  * - caller holds the socket locked
634  * - the socket may be either a client socket or a server socket
635  */
636 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
637 	__releases(&rx->sk.sk_lock.slock)
638 	__releases(&call->user_mutex)
639 {
640 	enum rxrpc_call_state state;
641 	struct rxrpc_call *call;
642 	unsigned long now, j;
643 	int ret;
644 
645 	struct rxrpc_send_params p = {
646 		.call.tx_total_len	= -1,
647 		.call.user_call_ID	= 0,
648 		.call.nr_timeouts	= 0,
649 		.call.interruptibility	= RXRPC_INTERRUPTIBLE,
650 		.abort_code		= 0,
651 		.command		= RXRPC_CMD_SEND_DATA,
652 		.exclusive		= false,
653 		.upgrade		= false,
654 	};
655 
656 	_enter("");
657 
658 	ret = rxrpc_sendmsg_cmsg(msg, &p);
659 	if (ret < 0)
660 		goto error_release_sock;
661 
662 	if (p.command == RXRPC_CMD_ACCEPT) {
663 		ret = -EINVAL;
664 		if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
665 			goto error_release_sock;
666 		call = rxrpc_accept_call(rx, p.call.user_call_ID, NULL);
667 		/* The socket is now unlocked. */
668 		if (IS_ERR(call))
669 			return PTR_ERR(call);
670 		ret = 0;
671 		goto out_put_unlock;
672 	}
673 
674 	call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
675 	if (!call) {
676 		ret = -EBADSLT;
677 		if (p.command != RXRPC_CMD_SEND_DATA)
678 			goto error_release_sock;
679 		call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
680 		/* The socket is now unlocked... */
681 		if (IS_ERR(call))
682 			return PTR_ERR(call);
683 		/* ... and we have the call lock. */
684 		ret = 0;
685 		if (READ_ONCE(call->state) == RXRPC_CALL_COMPLETE)
686 			goto out_put_unlock;
687 	} else {
688 		switch (READ_ONCE(call->state)) {
689 		case RXRPC_CALL_UNINITIALISED:
690 		case RXRPC_CALL_CLIENT_AWAIT_CONN:
691 		case RXRPC_CALL_SERVER_PREALLOC:
692 		case RXRPC_CALL_SERVER_SECURING:
693 		case RXRPC_CALL_SERVER_ACCEPTING:
694 			rxrpc_put_call(call, rxrpc_call_put);
695 			ret = -EBUSY;
696 			goto error_release_sock;
697 		default:
698 			break;
699 		}
700 
701 		ret = mutex_lock_interruptible(&call->user_mutex);
702 		release_sock(&rx->sk);
703 		if (ret < 0) {
704 			ret = -ERESTARTSYS;
705 			goto error_put;
706 		}
707 
708 		if (p.call.tx_total_len != -1) {
709 			ret = -EINVAL;
710 			if (call->tx_total_len != -1 ||
711 			    call->tx_pending ||
712 			    call->tx_top != 0)
713 				goto error_put;
714 			call->tx_total_len = p.call.tx_total_len;
715 		}
716 	}
717 
718 	switch (p.call.nr_timeouts) {
719 	case 3:
720 		j = msecs_to_jiffies(p.call.timeouts.normal);
721 		if (p.call.timeouts.normal > 0 && j == 0)
722 			j = 1;
723 		WRITE_ONCE(call->next_rx_timo, j);
724 		fallthrough;
725 	case 2:
726 		j = msecs_to_jiffies(p.call.timeouts.idle);
727 		if (p.call.timeouts.idle > 0 && j == 0)
728 			j = 1;
729 		WRITE_ONCE(call->next_req_timo, j);
730 		fallthrough;
731 	case 1:
732 		if (p.call.timeouts.hard > 0) {
733 			j = msecs_to_jiffies(p.call.timeouts.hard);
734 			now = jiffies;
735 			j += now;
736 			WRITE_ONCE(call->expect_term_by, j);
737 			rxrpc_reduce_call_timer(call, j, now,
738 						rxrpc_timer_set_for_hard);
739 		}
740 		break;
741 	}
742 
743 	state = READ_ONCE(call->state);
744 	_debug("CALL %d USR %lx ST %d on CONN %p",
745 	       call->debug_id, call->user_call_ID, state, call->conn);
746 
747 	if (state >= RXRPC_CALL_COMPLETE) {
748 		/* it's too late for this call */
749 		ret = -ESHUTDOWN;
750 	} else if (p.command == RXRPC_CMD_SEND_ABORT) {
751 		ret = 0;
752 		if (rxrpc_abort_call("CMD", call, 0, p.abort_code, -ECONNABORTED))
753 			ret = rxrpc_send_abort_packet(call);
754 	} else if (p.command != RXRPC_CMD_SEND_DATA) {
755 		ret = -EINVAL;
756 	} else if (rxrpc_is_client_call(call) &&
757 		   state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
758 		/* request phase complete for this client call */
759 		ret = -EPROTO;
760 	} else if (rxrpc_is_service_call(call) &&
761 		   state != RXRPC_CALL_SERVER_ACK_REQUEST &&
762 		   state != RXRPC_CALL_SERVER_SEND_REPLY) {
763 		/* Reply phase not begun or not complete for service call. */
764 		ret = -EPROTO;
765 	} else {
766 		ret = rxrpc_send_data(rx, call, msg, len, NULL);
767 	}
768 
769 out_put_unlock:
770 	mutex_unlock(&call->user_mutex);
771 error_put:
772 	rxrpc_put_call(call, rxrpc_call_put);
773 	_leave(" = %d", ret);
774 	return ret;
775 
776 error_release_sock:
777 	release_sock(&rx->sk);
778 	return ret;
779 }
780 
781 /**
782  * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
783  * @sock: The socket the call is on
784  * @call: The call to send data through
785  * @msg: The data to send
786  * @len: The amount of data to send
787  * @notify_end_tx: Notification that the last packet is queued.
788  *
789  * Allow a kernel service to send data on a call.  The call must be in an state
790  * appropriate to sending data.  No control data should be supplied in @msg,
791  * nor should an address be supplied.  MSG_MORE should be flagged if there's
792  * more data to come, otherwise this data will end the transmission phase.
793  */
794 int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
795 			   struct msghdr *msg, size_t len,
796 			   rxrpc_notify_end_tx_t notify_end_tx)
797 {
798 	int ret;
799 
800 	_enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
801 
802 	ASSERTCMP(msg->msg_name, ==, NULL);
803 	ASSERTCMP(msg->msg_control, ==, NULL);
804 
805 	mutex_lock(&call->user_mutex);
806 
807 	_debug("CALL %d USR %lx ST %d on CONN %p",
808 	       call->debug_id, call->user_call_ID, call->state, call->conn);
809 
810 	switch (READ_ONCE(call->state)) {
811 	case RXRPC_CALL_CLIENT_SEND_REQUEST:
812 	case RXRPC_CALL_SERVER_ACK_REQUEST:
813 	case RXRPC_CALL_SERVER_SEND_REPLY:
814 		ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
815 				      notify_end_tx);
816 		break;
817 	case RXRPC_CALL_COMPLETE:
818 		read_lock_bh(&call->state_lock);
819 		ret = call->error;
820 		read_unlock_bh(&call->state_lock);
821 		break;
822 	default:
823 		/* Request phase complete for this client call */
824 		trace_rxrpc_rx_eproto(call, 0, tracepoint_string("late_send"));
825 		ret = -EPROTO;
826 		break;
827 	}
828 
829 	mutex_unlock(&call->user_mutex);
830 	_leave(" = %d", ret);
831 	return ret;
832 }
833 EXPORT_SYMBOL(rxrpc_kernel_send_data);
834 
835 /**
836  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
837  * @sock: The socket the call is on
838  * @call: The call to be aborted
839  * @abort_code: The abort code to stick into the ABORT packet
840  * @error: Local error value
841  * @why: 3-char string indicating why.
842  *
843  * Allow a kernel service to abort a call, if it's still in an abortable state
844  * and return true if the call was aborted, false if it was already complete.
845  */
846 bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
847 			     u32 abort_code, int error, const char *why)
848 {
849 	bool aborted;
850 
851 	_enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
852 
853 	mutex_lock(&call->user_mutex);
854 
855 	aborted = rxrpc_abort_call(why, call, 0, abort_code, error);
856 	if (aborted)
857 		rxrpc_send_abort_packet(call);
858 
859 	mutex_unlock(&call->user_mutex);
860 	return aborted;
861 }
862 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
863 
864 /**
865  * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
866  * @sock: The socket the call is on
867  * @call: The call to be informed
868  * @tx_total_len: The amount of data to be transmitted for this call
869  *
870  * Allow a kernel service to set the total transmit length on a call.  This
871  * allows buffer-to-packet encrypt-and-copy to be performed.
872  *
873  * This function is primarily for use for setting the reply length since the
874  * request length can be set when beginning the call.
875  */
876 void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
877 				s64 tx_total_len)
878 {
879 	WARN_ON(call->tx_total_len != -1);
880 	call->tx_total_len = tx_total_len;
881 }
882 EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);
883