xref: /linux/net/rxrpc/sendmsg.c (revision 2dbc0838bcf24ca59cabc3130cf3b1d6809cdcd4)
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  * Wait for space to appear in the Tx queue or a signal to occur.
22  */
23 static int rxrpc_wait_for_tx_window_intr(struct rxrpc_sock *rx,
24 					 struct rxrpc_call *call,
25 					 long *timeo)
26 {
27 	for (;;) {
28 		set_current_state(TASK_INTERRUPTIBLE);
29 		if (call->tx_top - call->tx_hard_ack <
30 		    min_t(unsigned int, call->tx_winsize,
31 			  call->cong_cwnd + call->cong_extra))
32 			return 0;
33 
34 		if (call->state >= RXRPC_CALL_COMPLETE)
35 			return call->error;
36 
37 		if (signal_pending(current))
38 			return sock_intr_errno(*timeo);
39 
40 		trace_rxrpc_transmit(call, rxrpc_transmit_wait);
41 		mutex_unlock(&call->user_mutex);
42 		*timeo = schedule_timeout(*timeo);
43 		if (mutex_lock_interruptible(&call->user_mutex) < 0)
44 			return sock_intr_errno(*timeo);
45 	}
46 }
47 
48 /*
49  * Wait for space to appear in the Tx queue uninterruptibly, but with
50  * a timeout of 2*RTT if no progress was made and a signal occurred.
51  */
52 static int rxrpc_wait_for_tx_window_nonintr(struct rxrpc_sock *rx,
53 					    struct rxrpc_call *call)
54 {
55 	rxrpc_seq_t tx_start, tx_win;
56 	signed long rtt2, timeout;
57 	u64 rtt;
58 
59 	rtt = READ_ONCE(call->peer->rtt);
60 	rtt2 = nsecs_to_jiffies64(rtt) * 2;
61 	if (rtt2 < 1)
62 		rtt2 = 1;
63 
64 	timeout = rtt2;
65 	tx_start = READ_ONCE(call->tx_hard_ack);
66 
67 	for (;;) {
68 		set_current_state(TASK_UNINTERRUPTIBLE);
69 
70 		tx_win = READ_ONCE(call->tx_hard_ack);
71 		if (call->tx_top - tx_win <
72 		    min_t(unsigned int, call->tx_winsize,
73 			  call->cong_cwnd + call->cong_extra))
74 			return 0;
75 
76 		if (call->state >= RXRPC_CALL_COMPLETE)
77 			return call->error;
78 
79 		if (test_bit(RXRPC_CALL_IS_INTR, &call->flags) &&
80 		    timeout == 0 &&
81 		    tx_win == tx_start && signal_pending(current))
82 			return -EINTR;
83 
84 		if (tx_win != tx_start) {
85 			timeout = rtt2;
86 			tx_start = tx_win;
87 		}
88 
89 		trace_rxrpc_transmit(call, rxrpc_transmit_wait);
90 		timeout = schedule_timeout(timeout);
91 	}
92 }
93 
94 /*
95  * wait for space to appear in the transmit/ACK window
96  * - caller holds the socket locked
97  */
98 static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
99 				    struct rxrpc_call *call,
100 				    long *timeo,
101 				    bool waitall)
102 {
103 	DECLARE_WAITQUEUE(myself, current);
104 	int ret;
105 
106 	_enter(",{%u,%u,%u}",
107 	       call->tx_hard_ack, call->tx_top, call->tx_winsize);
108 
109 	add_wait_queue(&call->waitq, &myself);
110 
111 	if (waitall)
112 		ret = rxrpc_wait_for_tx_window_nonintr(rx, call);
113 	else
114 		ret = rxrpc_wait_for_tx_window_intr(rx, call, timeo);
115 
116 	remove_wait_queue(&call->waitq, &myself);
117 	set_current_state(TASK_RUNNING);
118 	_leave(" = %d", ret);
119 	return ret;
120 }
121 
122 /*
123  * Schedule an instant Tx resend.
124  */
125 static inline void rxrpc_instant_resend(struct rxrpc_call *call, int ix)
126 {
127 	spin_lock_bh(&call->lock);
128 
129 	if (call->state < RXRPC_CALL_COMPLETE) {
130 		call->rxtx_annotations[ix] =
131 			(call->rxtx_annotations[ix] & RXRPC_TX_ANNO_LAST) |
132 			RXRPC_TX_ANNO_RETRANS;
133 		if (!test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
134 			rxrpc_queue_call(call);
135 	}
136 
137 	spin_unlock_bh(&call->lock);
138 }
139 
140 /*
141  * Notify the owner of the call that the transmit phase is ended and the last
142  * packet has been queued.
143  */
144 static void rxrpc_notify_end_tx(struct rxrpc_sock *rx, struct rxrpc_call *call,
145 				rxrpc_notify_end_tx_t notify_end_tx)
146 {
147 	if (notify_end_tx)
148 		notify_end_tx(&rx->sk, call, call->user_call_ID);
149 }
150 
151 /*
152  * Queue a DATA packet for transmission, set the resend timeout and send
153  * the packet immediately.  Returns the error from rxrpc_send_data_packet()
154  * in case the caller wants to do something with it.
155  */
156 static int rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
157 			      struct sk_buff *skb, bool last,
158 			      rxrpc_notify_end_tx_t notify_end_tx)
159 {
160 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
161 	unsigned long now;
162 	rxrpc_seq_t seq = sp->hdr.seq;
163 	int ret, ix;
164 	u8 annotation = RXRPC_TX_ANNO_UNACK;
165 
166 	_net("queue skb %p [%d]", skb, seq);
167 
168 	ASSERTCMP(seq, ==, call->tx_top + 1);
169 
170 	if (last)
171 		annotation |= RXRPC_TX_ANNO_LAST;
172 
173 	/* We have to set the timestamp before queueing as the retransmit
174 	 * algorithm can see the packet as soon as we queue it.
175 	 */
176 	skb->tstamp = ktime_get_real();
177 
178 	ix = seq & RXRPC_RXTX_BUFF_MASK;
179 	rxrpc_get_skb(skb, rxrpc_skb_tx_got);
180 	call->rxtx_annotations[ix] = annotation;
181 	smp_wmb();
182 	call->rxtx_buffer[ix] = skb;
183 	call->tx_top = seq;
184 	if (last)
185 		trace_rxrpc_transmit(call, rxrpc_transmit_queue_last);
186 	else
187 		trace_rxrpc_transmit(call, rxrpc_transmit_queue);
188 
189 	if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {
190 		_debug("________awaiting reply/ACK__________");
191 		write_lock_bh(&call->state_lock);
192 		switch (call->state) {
193 		case RXRPC_CALL_CLIENT_SEND_REQUEST:
194 			call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
195 			rxrpc_notify_end_tx(rx, call, notify_end_tx);
196 			break;
197 		case RXRPC_CALL_SERVER_ACK_REQUEST:
198 			call->state = RXRPC_CALL_SERVER_SEND_REPLY;
199 			now = jiffies;
200 			WRITE_ONCE(call->ack_at, now + MAX_JIFFY_OFFSET);
201 			if (call->ackr_reason == RXRPC_ACK_DELAY)
202 				call->ackr_reason = 0;
203 			trace_rxrpc_timer(call, rxrpc_timer_init_for_send_reply, now);
204 			if (!last)
205 				break;
206 			/* Fall through */
207 		case RXRPC_CALL_SERVER_SEND_REPLY:
208 			call->state = RXRPC_CALL_SERVER_AWAIT_ACK;
209 			rxrpc_notify_end_tx(rx, call, notify_end_tx);
210 			break;
211 		default:
212 			break;
213 		}
214 		write_unlock_bh(&call->state_lock);
215 	}
216 
217 	if (seq == 1 && rxrpc_is_client_call(call))
218 		rxrpc_expose_client_call(call);
219 
220 	ret = rxrpc_send_data_packet(call, skb, false);
221 	if (ret < 0) {
222 		switch (ret) {
223 		case -ENETUNREACH:
224 		case -EHOSTUNREACH:
225 		case -ECONNREFUSED:
226 			rxrpc_set_call_completion(call,
227 						  RXRPC_CALL_LOCAL_ERROR,
228 						  0, ret);
229 			goto out;
230 		}
231 		_debug("need instant resend %d", ret);
232 		rxrpc_instant_resend(call, ix);
233 	} else {
234 		unsigned long now = jiffies, resend_at;
235 
236 		if (call->peer->rtt_usage > 1)
237 			resend_at = nsecs_to_jiffies(call->peer->rtt * 3 / 2);
238 		else
239 			resend_at = rxrpc_resend_timeout;
240 		if (resend_at < 1)
241 			resend_at = 1;
242 
243 		resend_at += now;
244 		WRITE_ONCE(call->resend_at, resend_at);
245 		rxrpc_reduce_call_timer(call, resend_at, now,
246 					rxrpc_timer_set_for_send);
247 	}
248 
249 out:
250 	rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
251 	_leave(" = %d", ret);
252 	return ret;
253 }
254 
255 /*
256  * send data through a socket
257  * - must be called in process context
258  * - The caller holds the call user access mutex, but not the socket lock.
259  */
260 static int rxrpc_send_data(struct rxrpc_sock *rx,
261 			   struct rxrpc_call *call,
262 			   struct msghdr *msg, size_t len,
263 			   rxrpc_notify_end_tx_t notify_end_tx)
264 {
265 	struct rxrpc_skb_priv *sp;
266 	struct sk_buff *skb;
267 	struct sock *sk = &rx->sk;
268 	long timeo;
269 	bool more;
270 	int ret, copied;
271 
272 	timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
273 
274 	/* this should be in poll */
275 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
276 
277 	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
278 		return -EPIPE;
279 
280 	more = msg->msg_flags & MSG_MORE;
281 
282 	if (call->tx_total_len != -1) {
283 		if (len > call->tx_total_len)
284 			return -EMSGSIZE;
285 		if (!more && len != call->tx_total_len)
286 			return -EMSGSIZE;
287 	}
288 
289 	skb = call->tx_pending;
290 	call->tx_pending = NULL;
291 	rxrpc_see_skb(skb, rxrpc_skb_tx_seen);
292 
293 	copied = 0;
294 	do {
295 		/* Check to see if there's a ping ACK to reply to. */
296 		if (call->ackr_reason == RXRPC_ACK_PING_RESPONSE)
297 			rxrpc_send_ack_packet(call, false, NULL);
298 
299 		if (!skb) {
300 			size_t size, chunk, max, space;
301 
302 			_debug("alloc");
303 
304 			if (call->tx_top - call->tx_hard_ack >=
305 			    min_t(unsigned int, call->tx_winsize,
306 				  call->cong_cwnd + call->cong_extra)) {
307 				ret = -EAGAIN;
308 				if (msg->msg_flags & MSG_DONTWAIT)
309 					goto maybe_error;
310 				ret = rxrpc_wait_for_tx_window(rx, call,
311 							       &timeo,
312 							       msg->msg_flags & MSG_WAITALL);
313 				if (ret < 0)
314 					goto maybe_error;
315 			}
316 
317 			max = RXRPC_JUMBO_DATALEN;
318 			max -= call->conn->security_size;
319 			max &= ~(call->conn->size_align - 1UL);
320 
321 			chunk = max;
322 			if (chunk > msg_data_left(msg) && !more)
323 				chunk = msg_data_left(msg);
324 
325 			space = chunk + call->conn->size_align;
326 			space &= ~(call->conn->size_align - 1UL);
327 
328 			size = space + call->conn->security_size;
329 
330 			_debug("SIZE: %zu/%zu/%zu", chunk, space, size);
331 
332 			/* create a buffer that we can retain until it's ACK'd */
333 			skb = sock_alloc_send_skb(
334 				sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
335 			if (!skb)
336 				goto maybe_error;
337 
338 			rxrpc_new_skb(skb, rxrpc_skb_tx_new);
339 
340 			_debug("ALLOC SEND %p", skb);
341 
342 			ASSERTCMP(skb->mark, ==, 0);
343 
344 			_debug("HS: %u", call->conn->security_size);
345 			skb_reserve(skb, call->conn->security_size);
346 			skb->len += call->conn->security_size;
347 
348 			sp = rxrpc_skb(skb);
349 			sp->remain = chunk;
350 			if (sp->remain > skb_tailroom(skb))
351 				sp->remain = skb_tailroom(skb);
352 
353 			_net("skb: hr %d, tr %d, hl %d, rm %d",
354 			       skb_headroom(skb),
355 			       skb_tailroom(skb),
356 			       skb_headlen(skb),
357 			       sp->remain);
358 
359 			skb->ip_summed = CHECKSUM_UNNECESSARY;
360 		}
361 
362 		_debug("append");
363 		sp = rxrpc_skb(skb);
364 
365 		/* append next segment of data to the current buffer */
366 		if (msg_data_left(msg) > 0) {
367 			int copy = skb_tailroom(skb);
368 			ASSERTCMP(copy, >, 0);
369 			if (copy > msg_data_left(msg))
370 				copy = msg_data_left(msg);
371 			if (copy > sp->remain)
372 				copy = sp->remain;
373 
374 			_debug("add");
375 			ret = skb_add_data(skb, &msg->msg_iter, copy);
376 			_debug("added");
377 			if (ret < 0)
378 				goto efault;
379 			sp->remain -= copy;
380 			skb->mark += copy;
381 			copied += copy;
382 			if (call->tx_total_len != -1)
383 				call->tx_total_len -= copy;
384 		}
385 
386 		/* check for the far side aborting the call or a network error
387 		 * occurring */
388 		if (call->state == RXRPC_CALL_COMPLETE)
389 			goto call_terminated;
390 
391 		/* add the packet to the send queue if it's now full */
392 		if (sp->remain <= 0 ||
393 		    (msg_data_left(msg) == 0 && !more)) {
394 			struct rxrpc_connection *conn = call->conn;
395 			uint32_t seq;
396 			size_t pad;
397 
398 			/* pad out if we're using security */
399 			if (conn->security_ix) {
400 				pad = conn->security_size + skb->mark;
401 				pad = conn->size_align - pad;
402 				pad &= conn->size_align - 1;
403 				_debug("pad %zu", pad);
404 				if (pad)
405 					skb_put_zero(skb, pad);
406 			}
407 
408 			seq = call->tx_top + 1;
409 
410 			sp->hdr.seq	= seq;
411 			sp->hdr._rsvd	= 0;
412 			sp->hdr.flags	= conn->out_clientflag;
413 
414 			if (msg_data_left(msg) == 0 && !more)
415 				sp->hdr.flags |= RXRPC_LAST_PACKET;
416 			else if (call->tx_top - call->tx_hard_ack <
417 				 call->tx_winsize)
418 				sp->hdr.flags |= RXRPC_MORE_PACKETS;
419 
420 			ret = conn->security->secure_packet(
421 				call, skb, skb->mark, skb->head);
422 			if (ret < 0)
423 				goto out;
424 
425 			ret = rxrpc_queue_packet(rx, call, skb,
426 						 !msg_data_left(msg) && !more,
427 						 notify_end_tx);
428 			/* Should check for failure here */
429 			skb = NULL;
430 		}
431 	} while (msg_data_left(msg) > 0);
432 
433 success:
434 	ret = copied;
435 out:
436 	call->tx_pending = skb;
437 	_leave(" = %d", ret);
438 	return ret;
439 
440 call_terminated:
441 	rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
442 	_leave(" = %d", call->error);
443 	return call->error;
444 
445 maybe_error:
446 	if (copied)
447 		goto success;
448 	goto out;
449 
450 efault:
451 	ret = -EFAULT;
452 	goto out;
453 }
454 
455 /*
456  * extract control messages from the sendmsg() control buffer
457  */
458 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
459 {
460 	struct cmsghdr *cmsg;
461 	bool got_user_ID = false;
462 	int len;
463 
464 	if (msg->msg_controllen == 0)
465 		return -EINVAL;
466 
467 	for_each_cmsghdr(cmsg, msg) {
468 		if (!CMSG_OK(msg, cmsg))
469 			return -EINVAL;
470 
471 		len = cmsg->cmsg_len - sizeof(struct cmsghdr);
472 		_debug("CMSG %d, %d, %d",
473 		       cmsg->cmsg_level, cmsg->cmsg_type, len);
474 
475 		if (cmsg->cmsg_level != SOL_RXRPC)
476 			continue;
477 
478 		switch (cmsg->cmsg_type) {
479 		case RXRPC_USER_CALL_ID:
480 			if (msg->msg_flags & MSG_CMSG_COMPAT) {
481 				if (len != sizeof(u32))
482 					return -EINVAL;
483 				p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
484 			} else {
485 				if (len != sizeof(unsigned long))
486 					return -EINVAL;
487 				p->call.user_call_ID = *(unsigned long *)
488 					CMSG_DATA(cmsg);
489 			}
490 			got_user_ID = true;
491 			break;
492 
493 		case RXRPC_ABORT:
494 			if (p->command != RXRPC_CMD_SEND_DATA)
495 				return -EINVAL;
496 			p->command = RXRPC_CMD_SEND_ABORT;
497 			if (len != sizeof(p->abort_code))
498 				return -EINVAL;
499 			p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
500 			if (p->abort_code == 0)
501 				return -EINVAL;
502 			break;
503 
504 		case RXRPC_ACCEPT:
505 			if (p->command != RXRPC_CMD_SEND_DATA)
506 				return -EINVAL;
507 			p->command = RXRPC_CMD_ACCEPT;
508 			if (len != 0)
509 				return -EINVAL;
510 			break;
511 
512 		case RXRPC_EXCLUSIVE_CALL:
513 			p->exclusive = true;
514 			if (len != 0)
515 				return -EINVAL;
516 			break;
517 
518 		case RXRPC_UPGRADE_SERVICE:
519 			p->upgrade = true;
520 			if (len != 0)
521 				return -EINVAL;
522 			break;
523 
524 		case RXRPC_TX_LENGTH:
525 			if (p->call.tx_total_len != -1 || len != sizeof(__s64))
526 				return -EINVAL;
527 			p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
528 			if (p->call.tx_total_len < 0)
529 				return -EINVAL;
530 			break;
531 
532 		case RXRPC_SET_CALL_TIMEOUT:
533 			if (len & 3 || len < 4 || len > 12)
534 				return -EINVAL;
535 			memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
536 			p->call.nr_timeouts = len / 4;
537 			if (p->call.timeouts.hard > INT_MAX / HZ)
538 				return -ERANGE;
539 			if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
540 				return -ERANGE;
541 			if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
542 				return -ERANGE;
543 			break;
544 
545 		default:
546 			return -EINVAL;
547 		}
548 	}
549 
550 	if (!got_user_ID)
551 		return -EINVAL;
552 	if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
553 		return -EINVAL;
554 	_leave(" = 0");
555 	return 0;
556 }
557 
558 /*
559  * Create a new client call for sendmsg().
560  * - Called with the socket lock held, which it must release.
561  * - If it returns a call, the call's lock will need releasing by the caller.
562  */
563 static struct rxrpc_call *
564 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
565 				  struct rxrpc_send_params *p)
566 	__releases(&rx->sk.sk_lock.slock)
567 	__acquires(&call->user_mutex)
568 {
569 	struct rxrpc_conn_parameters cp;
570 	struct rxrpc_call *call;
571 	struct key *key;
572 
573 	DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
574 
575 	_enter("");
576 
577 	if (!msg->msg_name) {
578 		release_sock(&rx->sk);
579 		return ERR_PTR(-EDESTADDRREQ);
580 	}
581 
582 	key = rx->key;
583 	if (key && !rx->key->payload.data[0])
584 		key = NULL;
585 
586 	memset(&cp, 0, sizeof(cp));
587 	cp.local		= rx->local;
588 	cp.key			= rx->key;
589 	cp.security_level	= rx->min_sec_level;
590 	cp.exclusive		= rx->exclusive | p->exclusive;
591 	cp.upgrade		= p->upgrade;
592 	cp.service_id		= srx->srx_service;
593 	call = rxrpc_new_client_call(rx, &cp, srx, &p->call, GFP_KERNEL,
594 				     atomic_inc_return(&rxrpc_debug_id));
595 	/* The socket is now unlocked */
596 
597 	rxrpc_put_peer(cp.peer);
598 	_leave(" = %p\n", call);
599 	return call;
600 }
601 
602 /*
603  * send a message forming part of a client call through an RxRPC socket
604  * - caller holds the socket locked
605  * - the socket may be either a client socket or a server socket
606  */
607 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
608 	__releases(&rx->sk.sk_lock.slock)
609 	__releases(&call->user_mutex)
610 {
611 	enum rxrpc_call_state state;
612 	struct rxrpc_call *call;
613 	unsigned long now, j;
614 	int ret;
615 
616 	struct rxrpc_send_params p = {
617 		.call.tx_total_len	= -1,
618 		.call.user_call_ID	= 0,
619 		.call.nr_timeouts	= 0,
620 		.call.intr		= true,
621 		.abort_code		= 0,
622 		.command		= RXRPC_CMD_SEND_DATA,
623 		.exclusive		= false,
624 		.upgrade		= false,
625 	};
626 
627 	_enter("");
628 
629 	ret = rxrpc_sendmsg_cmsg(msg, &p);
630 	if (ret < 0)
631 		goto error_release_sock;
632 
633 	if (p.command == RXRPC_CMD_ACCEPT) {
634 		ret = -EINVAL;
635 		if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
636 			goto error_release_sock;
637 		call = rxrpc_accept_call(rx, p.call.user_call_ID, NULL);
638 		/* The socket is now unlocked. */
639 		if (IS_ERR(call))
640 			return PTR_ERR(call);
641 		ret = 0;
642 		goto out_put_unlock;
643 	}
644 
645 	call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
646 	if (!call) {
647 		ret = -EBADSLT;
648 		if (p.command != RXRPC_CMD_SEND_DATA)
649 			goto error_release_sock;
650 		call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
651 		/* The socket is now unlocked... */
652 		if (IS_ERR(call))
653 			return PTR_ERR(call);
654 		/* ... and we have the call lock. */
655 	} else {
656 		switch (READ_ONCE(call->state)) {
657 		case RXRPC_CALL_UNINITIALISED:
658 		case RXRPC_CALL_CLIENT_AWAIT_CONN:
659 		case RXRPC_CALL_SERVER_PREALLOC:
660 		case RXRPC_CALL_SERVER_SECURING:
661 		case RXRPC_CALL_SERVER_ACCEPTING:
662 			ret = -EBUSY;
663 			goto error_release_sock;
664 		default:
665 			break;
666 		}
667 
668 		ret = mutex_lock_interruptible(&call->user_mutex);
669 		release_sock(&rx->sk);
670 		if (ret < 0) {
671 			ret = -ERESTARTSYS;
672 			goto error_put;
673 		}
674 
675 		if (p.call.tx_total_len != -1) {
676 			ret = -EINVAL;
677 			if (call->tx_total_len != -1 ||
678 			    call->tx_pending ||
679 			    call->tx_top != 0)
680 				goto error_put;
681 			call->tx_total_len = p.call.tx_total_len;
682 		}
683 	}
684 
685 	switch (p.call.nr_timeouts) {
686 	case 3:
687 		j = msecs_to_jiffies(p.call.timeouts.normal);
688 		if (p.call.timeouts.normal > 0 && j == 0)
689 			j = 1;
690 		WRITE_ONCE(call->next_rx_timo, j);
691 		/* Fall through */
692 	case 2:
693 		j = msecs_to_jiffies(p.call.timeouts.idle);
694 		if (p.call.timeouts.idle > 0 && j == 0)
695 			j = 1;
696 		WRITE_ONCE(call->next_req_timo, j);
697 		/* Fall through */
698 	case 1:
699 		if (p.call.timeouts.hard > 0) {
700 			j = msecs_to_jiffies(p.call.timeouts.hard);
701 			now = jiffies;
702 			j += now;
703 			WRITE_ONCE(call->expect_term_by, j);
704 			rxrpc_reduce_call_timer(call, j, now,
705 						rxrpc_timer_set_for_hard);
706 		}
707 		break;
708 	}
709 
710 	state = READ_ONCE(call->state);
711 	_debug("CALL %d USR %lx ST %d on CONN %p",
712 	       call->debug_id, call->user_call_ID, state, call->conn);
713 
714 	if (state >= RXRPC_CALL_COMPLETE) {
715 		/* it's too late for this call */
716 		ret = -ESHUTDOWN;
717 	} else if (p.command == RXRPC_CMD_SEND_ABORT) {
718 		ret = 0;
719 		if (rxrpc_abort_call("CMD", call, 0, p.abort_code, -ECONNABORTED))
720 			ret = rxrpc_send_abort_packet(call);
721 	} else if (p.command != RXRPC_CMD_SEND_DATA) {
722 		ret = -EINVAL;
723 	} else if (rxrpc_is_client_call(call) &&
724 		   state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
725 		/* request phase complete for this client call */
726 		ret = -EPROTO;
727 	} else if (rxrpc_is_service_call(call) &&
728 		   state != RXRPC_CALL_SERVER_ACK_REQUEST &&
729 		   state != RXRPC_CALL_SERVER_SEND_REPLY) {
730 		/* Reply phase not begun or not complete for service call. */
731 		ret = -EPROTO;
732 	} else {
733 		ret = rxrpc_send_data(rx, call, msg, len, NULL);
734 	}
735 
736 out_put_unlock:
737 	mutex_unlock(&call->user_mutex);
738 error_put:
739 	rxrpc_put_call(call, rxrpc_call_put);
740 	_leave(" = %d", ret);
741 	return ret;
742 
743 error_release_sock:
744 	release_sock(&rx->sk);
745 	return ret;
746 }
747 
748 /**
749  * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
750  * @sock: The socket the call is on
751  * @call: The call to send data through
752  * @msg: The data to send
753  * @len: The amount of data to send
754  * @notify_end_tx: Notification that the last packet is queued.
755  *
756  * Allow a kernel service to send data on a call.  The call must be in an state
757  * appropriate to sending data.  No control data should be supplied in @msg,
758  * nor should an address be supplied.  MSG_MORE should be flagged if there's
759  * more data to come, otherwise this data will end the transmission phase.
760  */
761 int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
762 			   struct msghdr *msg, size_t len,
763 			   rxrpc_notify_end_tx_t notify_end_tx)
764 {
765 	int ret;
766 
767 	_enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
768 
769 	ASSERTCMP(msg->msg_name, ==, NULL);
770 	ASSERTCMP(msg->msg_control, ==, NULL);
771 
772 	mutex_lock(&call->user_mutex);
773 
774 	_debug("CALL %d USR %lx ST %d on CONN %p",
775 	       call->debug_id, call->user_call_ID, call->state, call->conn);
776 
777 	switch (READ_ONCE(call->state)) {
778 	case RXRPC_CALL_CLIENT_SEND_REQUEST:
779 	case RXRPC_CALL_SERVER_ACK_REQUEST:
780 	case RXRPC_CALL_SERVER_SEND_REPLY:
781 		ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
782 				      notify_end_tx);
783 		break;
784 	case RXRPC_CALL_COMPLETE:
785 		read_lock_bh(&call->state_lock);
786 		ret = call->error;
787 		read_unlock_bh(&call->state_lock);
788 		break;
789 	default:
790 		/* Request phase complete for this client call */
791 		trace_rxrpc_rx_eproto(call, 0, tracepoint_string("late_send"));
792 		ret = -EPROTO;
793 		break;
794 	}
795 
796 	mutex_unlock(&call->user_mutex);
797 	_leave(" = %d", ret);
798 	return ret;
799 }
800 EXPORT_SYMBOL(rxrpc_kernel_send_data);
801 
802 /**
803  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
804  * @sock: The socket the call is on
805  * @call: The call to be aborted
806  * @abort_code: The abort code to stick into the ABORT packet
807  * @error: Local error value
808  * @why: 3-char string indicating why.
809  *
810  * Allow a kernel service to abort a call, if it's still in an abortable state
811  * and return true if the call was aborted, false if it was already complete.
812  */
813 bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
814 			     u32 abort_code, int error, const char *why)
815 {
816 	bool aborted;
817 
818 	_enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
819 
820 	mutex_lock(&call->user_mutex);
821 
822 	aborted = rxrpc_abort_call(why, call, 0, abort_code, error);
823 	if (aborted)
824 		rxrpc_send_abort_packet(call);
825 
826 	mutex_unlock(&call->user_mutex);
827 	return aborted;
828 }
829 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
830 
831 /**
832  * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
833  * @sock: The socket the call is on
834  * @call: The call to be informed
835  * @tx_total_len: The amount of data to be transmitted for this call
836  *
837  * Allow a kernel service to set the total transmit length on a call.  This
838  * allows buffer-to-packet encrypt-and-copy to be performed.
839  *
840  * This function is primarily for use for setting the reply length since the
841  * request length can be set when beginning the call.
842  */
843 void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
844 				s64 tx_total_len)
845 {
846 	WARN_ON(call->tx_total_len != -1);
847 	call->tx_total_len = tx_total_len;
848 }
849 EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);
850