xref: /openbmc/linux/net/rxrpc/sendmsg.c (revision cbdf59ad)
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 			rxrpc_notify_socket(call);
230 			goto out;
231 		}
232 		_debug("need instant resend %d", ret);
233 		rxrpc_instant_resend(call, ix);
234 	} else {
235 		unsigned long now = jiffies, resend_at;
236 
237 		if (call->peer->rtt_usage > 1)
238 			resend_at = nsecs_to_jiffies(call->peer->rtt * 3 / 2);
239 		else
240 			resend_at = rxrpc_resend_timeout;
241 		if (resend_at < 1)
242 			resend_at = 1;
243 
244 		resend_at += now;
245 		WRITE_ONCE(call->resend_at, resend_at);
246 		rxrpc_reduce_call_timer(call, resend_at, now,
247 					rxrpc_timer_set_for_send);
248 	}
249 
250 out:
251 	rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
252 	_leave(" = %d", ret);
253 	return ret;
254 }
255 
256 /*
257  * send data through a socket
258  * - must be called in process context
259  * - The caller holds the call user access mutex, but not the socket lock.
260  */
261 static int rxrpc_send_data(struct rxrpc_sock *rx,
262 			   struct rxrpc_call *call,
263 			   struct msghdr *msg, size_t len,
264 			   rxrpc_notify_end_tx_t notify_end_tx)
265 {
266 	struct rxrpc_skb_priv *sp;
267 	struct sk_buff *skb;
268 	struct sock *sk = &rx->sk;
269 	long timeo;
270 	bool more;
271 	int ret, copied;
272 
273 	timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
274 
275 	/* this should be in poll */
276 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
277 
278 	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
279 		return -EPIPE;
280 
281 	more = msg->msg_flags & MSG_MORE;
282 
283 	if (call->tx_total_len != -1) {
284 		if (len > call->tx_total_len)
285 			return -EMSGSIZE;
286 		if (!more && len != call->tx_total_len)
287 			return -EMSGSIZE;
288 	}
289 
290 	skb = call->tx_pending;
291 	call->tx_pending = NULL;
292 	rxrpc_see_skb(skb, rxrpc_skb_tx_seen);
293 
294 	copied = 0;
295 	do {
296 		/* Check to see if there's a ping ACK to reply to. */
297 		if (call->ackr_reason == RXRPC_ACK_PING_RESPONSE)
298 			rxrpc_send_ack_packet(call, false, NULL);
299 
300 		if (!skb) {
301 			size_t size, chunk, max, space;
302 
303 			_debug("alloc");
304 
305 			if (call->tx_top - call->tx_hard_ack >=
306 			    min_t(unsigned int, call->tx_winsize,
307 				  call->cong_cwnd + call->cong_extra)) {
308 				ret = -EAGAIN;
309 				if (msg->msg_flags & MSG_DONTWAIT)
310 					goto maybe_error;
311 				ret = rxrpc_wait_for_tx_window(rx, call,
312 							       &timeo,
313 							       msg->msg_flags & MSG_WAITALL);
314 				if (ret < 0)
315 					goto maybe_error;
316 			}
317 
318 			max = RXRPC_JUMBO_DATALEN;
319 			max -= call->conn->security_size;
320 			max &= ~(call->conn->size_align - 1UL);
321 
322 			chunk = max;
323 			if (chunk > msg_data_left(msg) && !more)
324 				chunk = msg_data_left(msg);
325 
326 			space = chunk + call->conn->size_align;
327 			space &= ~(call->conn->size_align - 1UL);
328 
329 			size = space + call->conn->security_size;
330 
331 			_debug("SIZE: %zu/%zu/%zu", chunk, space, size);
332 
333 			/* create a buffer that we can retain until it's ACK'd */
334 			skb = sock_alloc_send_skb(
335 				sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
336 			if (!skb)
337 				goto maybe_error;
338 
339 			rxrpc_new_skb(skb, rxrpc_skb_tx_new);
340 
341 			_debug("ALLOC SEND %p", skb);
342 
343 			ASSERTCMP(skb->mark, ==, 0);
344 
345 			_debug("HS: %u", call->conn->security_size);
346 			skb_reserve(skb, call->conn->security_size);
347 			skb->len += call->conn->security_size;
348 
349 			sp = rxrpc_skb(skb);
350 			sp->remain = chunk;
351 			if (sp->remain > skb_tailroom(skb))
352 				sp->remain = skb_tailroom(skb);
353 
354 			_net("skb: hr %d, tr %d, hl %d, rm %d",
355 			       skb_headroom(skb),
356 			       skb_tailroom(skb),
357 			       skb_headlen(skb),
358 			       sp->remain);
359 
360 			skb->ip_summed = CHECKSUM_UNNECESSARY;
361 		}
362 
363 		_debug("append");
364 		sp = rxrpc_skb(skb);
365 
366 		/* append next segment of data to the current buffer */
367 		if (msg_data_left(msg) > 0) {
368 			int copy = skb_tailroom(skb);
369 			ASSERTCMP(copy, >, 0);
370 			if (copy > msg_data_left(msg))
371 				copy = msg_data_left(msg);
372 			if (copy > sp->remain)
373 				copy = sp->remain;
374 
375 			_debug("add");
376 			ret = skb_add_data(skb, &msg->msg_iter, copy);
377 			_debug("added");
378 			if (ret < 0)
379 				goto efault;
380 			sp->remain -= copy;
381 			skb->mark += copy;
382 			copied += copy;
383 			if (call->tx_total_len != -1)
384 				call->tx_total_len -= copy;
385 		}
386 
387 		/* check for the far side aborting the call or a network error
388 		 * occurring */
389 		if (call->state == RXRPC_CALL_COMPLETE)
390 			goto call_terminated;
391 
392 		/* add the packet to the send queue if it's now full */
393 		if (sp->remain <= 0 ||
394 		    (msg_data_left(msg) == 0 && !more)) {
395 			struct rxrpc_connection *conn = call->conn;
396 			uint32_t seq;
397 			size_t pad;
398 
399 			/* pad out if we're using security */
400 			if (conn->security_ix) {
401 				pad = conn->security_size + skb->mark;
402 				pad = conn->size_align - pad;
403 				pad &= conn->size_align - 1;
404 				_debug("pad %zu", pad);
405 				if (pad)
406 					skb_put_zero(skb, pad);
407 			}
408 
409 			seq = call->tx_top + 1;
410 
411 			sp->hdr.seq	= seq;
412 			sp->hdr._rsvd	= 0;
413 			sp->hdr.flags	= conn->out_clientflag;
414 
415 			if (msg_data_left(msg) == 0 && !more)
416 				sp->hdr.flags |= RXRPC_LAST_PACKET;
417 			else if (call->tx_top - call->tx_hard_ack <
418 				 call->tx_winsize)
419 				sp->hdr.flags |= RXRPC_MORE_PACKETS;
420 
421 			ret = conn->security->secure_packet(
422 				call, skb, skb->mark, skb->head);
423 			if (ret < 0)
424 				goto out;
425 
426 			ret = rxrpc_queue_packet(rx, call, skb,
427 						 !msg_data_left(msg) && !more,
428 						 notify_end_tx);
429 			/* Should check for failure here */
430 			skb = NULL;
431 		}
432 	} while (msg_data_left(msg) > 0);
433 
434 success:
435 	ret = copied;
436 out:
437 	call->tx_pending = skb;
438 	_leave(" = %d", ret);
439 	return ret;
440 
441 call_terminated:
442 	rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
443 	_leave(" = %d", call->error);
444 	return call->error;
445 
446 maybe_error:
447 	if (copied)
448 		goto success;
449 	goto out;
450 
451 efault:
452 	ret = -EFAULT;
453 	goto out;
454 }
455 
456 /*
457  * extract control messages from the sendmsg() control buffer
458  */
459 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
460 {
461 	struct cmsghdr *cmsg;
462 	bool got_user_ID = false;
463 	int len;
464 
465 	if (msg->msg_controllen == 0)
466 		return -EINVAL;
467 
468 	for_each_cmsghdr(cmsg, msg) {
469 		if (!CMSG_OK(msg, cmsg))
470 			return -EINVAL;
471 
472 		len = cmsg->cmsg_len - sizeof(struct cmsghdr);
473 		_debug("CMSG %d, %d, %d",
474 		       cmsg->cmsg_level, cmsg->cmsg_type, len);
475 
476 		if (cmsg->cmsg_level != SOL_RXRPC)
477 			continue;
478 
479 		switch (cmsg->cmsg_type) {
480 		case RXRPC_USER_CALL_ID:
481 			if (msg->msg_flags & MSG_CMSG_COMPAT) {
482 				if (len != sizeof(u32))
483 					return -EINVAL;
484 				p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
485 			} else {
486 				if (len != sizeof(unsigned long))
487 					return -EINVAL;
488 				p->call.user_call_ID = *(unsigned long *)
489 					CMSG_DATA(cmsg);
490 			}
491 			got_user_ID = true;
492 			break;
493 
494 		case RXRPC_ABORT:
495 			if (p->command != RXRPC_CMD_SEND_DATA)
496 				return -EINVAL;
497 			p->command = RXRPC_CMD_SEND_ABORT;
498 			if (len != sizeof(p->abort_code))
499 				return -EINVAL;
500 			p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
501 			if (p->abort_code == 0)
502 				return -EINVAL;
503 			break;
504 
505 		case RXRPC_ACCEPT:
506 			if (p->command != RXRPC_CMD_SEND_DATA)
507 				return -EINVAL;
508 			p->command = RXRPC_CMD_ACCEPT;
509 			if (len != 0)
510 				return -EINVAL;
511 			break;
512 
513 		case RXRPC_EXCLUSIVE_CALL:
514 			p->exclusive = true;
515 			if (len != 0)
516 				return -EINVAL;
517 			break;
518 
519 		case RXRPC_UPGRADE_SERVICE:
520 			p->upgrade = true;
521 			if (len != 0)
522 				return -EINVAL;
523 			break;
524 
525 		case RXRPC_TX_LENGTH:
526 			if (p->call.tx_total_len != -1 || len != sizeof(__s64))
527 				return -EINVAL;
528 			p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
529 			if (p->call.tx_total_len < 0)
530 				return -EINVAL;
531 			break;
532 
533 		case RXRPC_SET_CALL_TIMEOUT:
534 			if (len & 3 || len < 4 || len > 12)
535 				return -EINVAL;
536 			memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
537 			p->call.nr_timeouts = len / 4;
538 			if (p->call.timeouts.hard > INT_MAX / HZ)
539 				return -ERANGE;
540 			if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
541 				return -ERANGE;
542 			if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
543 				return -ERANGE;
544 			break;
545 
546 		default:
547 			return -EINVAL;
548 		}
549 	}
550 
551 	if (!got_user_ID)
552 		return -EINVAL;
553 	if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
554 		return -EINVAL;
555 	_leave(" = 0");
556 	return 0;
557 }
558 
559 /*
560  * Create a new client call for sendmsg().
561  * - Called with the socket lock held, which it must release.
562  * - If it returns a call, the call's lock will need releasing by the caller.
563  */
564 static struct rxrpc_call *
565 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
566 				  struct rxrpc_send_params *p)
567 	__releases(&rx->sk.sk_lock.slock)
568 	__acquires(&call->user_mutex)
569 {
570 	struct rxrpc_conn_parameters cp;
571 	struct rxrpc_call *call;
572 	struct key *key;
573 
574 	DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
575 
576 	_enter("");
577 
578 	if (!msg->msg_name) {
579 		release_sock(&rx->sk);
580 		return ERR_PTR(-EDESTADDRREQ);
581 	}
582 
583 	key = rx->key;
584 	if (key && !rx->key->payload.data[0])
585 		key = NULL;
586 
587 	memset(&cp, 0, sizeof(cp));
588 	cp.local		= rx->local;
589 	cp.key			= rx->key;
590 	cp.security_level	= rx->min_sec_level;
591 	cp.exclusive		= rx->exclusive | p->exclusive;
592 	cp.upgrade		= p->upgrade;
593 	cp.service_id		= srx->srx_service;
594 	call = rxrpc_new_client_call(rx, &cp, srx, &p->call, GFP_KERNEL,
595 				     atomic_inc_return(&rxrpc_debug_id));
596 	/* The socket is now unlocked */
597 
598 	rxrpc_put_peer(cp.peer);
599 	_leave(" = %p\n", call);
600 	return call;
601 }
602 
603 /*
604  * send a message forming part of a client call through an RxRPC socket
605  * - caller holds the socket locked
606  * - the socket may be either a client socket or a server socket
607  */
608 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
609 	__releases(&rx->sk.sk_lock.slock)
610 	__releases(&call->user_mutex)
611 {
612 	enum rxrpc_call_state state;
613 	struct rxrpc_call *call;
614 	unsigned long now, j;
615 	int ret;
616 
617 	struct rxrpc_send_params p = {
618 		.call.tx_total_len	= -1,
619 		.call.user_call_ID	= 0,
620 		.call.nr_timeouts	= 0,
621 		.call.intr		= true,
622 		.abort_code		= 0,
623 		.command		= RXRPC_CMD_SEND_DATA,
624 		.exclusive		= false,
625 		.upgrade		= false,
626 	};
627 
628 	_enter("");
629 
630 	ret = rxrpc_sendmsg_cmsg(msg, &p);
631 	if (ret < 0)
632 		goto error_release_sock;
633 
634 	if (p.command == RXRPC_CMD_ACCEPT) {
635 		ret = -EINVAL;
636 		if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
637 			goto error_release_sock;
638 		call = rxrpc_accept_call(rx, p.call.user_call_ID, NULL);
639 		/* The socket is now unlocked. */
640 		if (IS_ERR(call))
641 			return PTR_ERR(call);
642 		ret = 0;
643 		goto out_put_unlock;
644 	}
645 
646 	call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
647 	if (!call) {
648 		ret = -EBADSLT;
649 		if (p.command != RXRPC_CMD_SEND_DATA)
650 			goto error_release_sock;
651 		call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
652 		/* The socket is now unlocked... */
653 		if (IS_ERR(call))
654 			return PTR_ERR(call);
655 		/* ... and we have the call lock. */
656 	} else {
657 		switch (READ_ONCE(call->state)) {
658 		case RXRPC_CALL_UNINITIALISED:
659 		case RXRPC_CALL_CLIENT_AWAIT_CONN:
660 		case RXRPC_CALL_SERVER_PREALLOC:
661 		case RXRPC_CALL_SERVER_SECURING:
662 		case RXRPC_CALL_SERVER_ACCEPTING:
663 			ret = -EBUSY;
664 			goto error_release_sock;
665 		default:
666 			break;
667 		}
668 
669 		ret = mutex_lock_interruptible(&call->user_mutex);
670 		release_sock(&rx->sk);
671 		if (ret < 0) {
672 			ret = -ERESTARTSYS;
673 			goto error_put;
674 		}
675 
676 		if (p.call.tx_total_len != -1) {
677 			ret = -EINVAL;
678 			if (call->tx_total_len != -1 ||
679 			    call->tx_pending ||
680 			    call->tx_top != 0)
681 				goto error_put;
682 			call->tx_total_len = p.call.tx_total_len;
683 		}
684 	}
685 
686 	switch (p.call.nr_timeouts) {
687 	case 3:
688 		j = msecs_to_jiffies(p.call.timeouts.normal);
689 		if (p.call.timeouts.normal > 0 && j == 0)
690 			j = 1;
691 		WRITE_ONCE(call->next_rx_timo, j);
692 		/* Fall through */
693 	case 2:
694 		j = msecs_to_jiffies(p.call.timeouts.idle);
695 		if (p.call.timeouts.idle > 0 && j == 0)
696 			j = 1;
697 		WRITE_ONCE(call->next_req_timo, j);
698 		/* Fall through */
699 	case 1:
700 		if (p.call.timeouts.hard > 0) {
701 			j = msecs_to_jiffies(p.call.timeouts.hard);
702 			now = jiffies;
703 			j += now;
704 			WRITE_ONCE(call->expect_term_by, j);
705 			rxrpc_reduce_call_timer(call, j, now,
706 						rxrpc_timer_set_for_hard);
707 		}
708 		break;
709 	}
710 
711 	state = READ_ONCE(call->state);
712 	_debug("CALL %d USR %lx ST %d on CONN %p",
713 	       call->debug_id, call->user_call_ID, state, call->conn);
714 
715 	if (state >= RXRPC_CALL_COMPLETE) {
716 		/* it's too late for this call */
717 		ret = -ESHUTDOWN;
718 	} else if (p.command == RXRPC_CMD_SEND_ABORT) {
719 		ret = 0;
720 		if (rxrpc_abort_call("CMD", call, 0, p.abort_code, -ECONNABORTED))
721 			ret = rxrpc_send_abort_packet(call);
722 	} else if (p.command != RXRPC_CMD_SEND_DATA) {
723 		ret = -EINVAL;
724 	} else if (rxrpc_is_client_call(call) &&
725 		   state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
726 		/* request phase complete for this client call */
727 		ret = -EPROTO;
728 	} else if (rxrpc_is_service_call(call) &&
729 		   state != RXRPC_CALL_SERVER_ACK_REQUEST &&
730 		   state != RXRPC_CALL_SERVER_SEND_REPLY) {
731 		/* Reply phase not begun or not complete for service call. */
732 		ret = -EPROTO;
733 	} else {
734 		ret = rxrpc_send_data(rx, call, msg, len, NULL);
735 	}
736 
737 out_put_unlock:
738 	mutex_unlock(&call->user_mutex);
739 error_put:
740 	rxrpc_put_call(call, rxrpc_call_put);
741 	_leave(" = %d", ret);
742 	return ret;
743 
744 error_release_sock:
745 	release_sock(&rx->sk);
746 	return ret;
747 }
748 
749 /**
750  * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
751  * @sock: The socket the call is on
752  * @call: The call to send data through
753  * @msg: The data to send
754  * @len: The amount of data to send
755  * @notify_end_tx: Notification that the last packet is queued.
756  *
757  * Allow a kernel service to send data on a call.  The call must be in an state
758  * appropriate to sending data.  No control data should be supplied in @msg,
759  * nor should an address be supplied.  MSG_MORE should be flagged if there's
760  * more data to come, otherwise this data will end the transmission phase.
761  */
762 int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
763 			   struct msghdr *msg, size_t len,
764 			   rxrpc_notify_end_tx_t notify_end_tx)
765 {
766 	int ret;
767 
768 	_enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
769 
770 	ASSERTCMP(msg->msg_name, ==, NULL);
771 	ASSERTCMP(msg->msg_control, ==, NULL);
772 
773 	mutex_lock(&call->user_mutex);
774 
775 	_debug("CALL %d USR %lx ST %d on CONN %p",
776 	       call->debug_id, call->user_call_ID, call->state, call->conn);
777 
778 	switch (READ_ONCE(call->state)) {
779 	case RXRPC_CALL_CLIENT_SEND_REQUEST:
780 	case RXRPC_CALL_SERVER_ACK_REQUEST:
781 	case RXRPC_CALL_SERVER_SEND_REPLY:
782 		ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
783 				      notify_end_tx);
784 		break;
785 	case RXRPC_CALL_COMPLETE:
786 		read_lock_bh(&call->state_lock);
787 		ret = call->error;
788 		read_unlock_bh(&call->state_lock);
789 		break;
790 	default:
791 		/* Request phase complete for this client call */
792 		trace_rxrpc_rx_eproto(call, 0, tracepoint_string("late_send"));
793 		ret = -EPROTO;
794 		break;
795 	}
796 
797 	mutex_unlock(&call->user_mutex);
798 	_leave(" = %d", ret);
799 	return ret;
800 }
801 EXPORT_SYMBOL(rxrpc_kernel_send_data);
802 
803 /**
804  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
805  * @sock: The socket the call is on
806  * @call: The call to be aborted
807  * @abort_code: The abort code to stick into the ABORT packet
808  * @error: Local error value
809  * @why: 3-char string indicating why.
810  *
811  * Allow a kernel service to abort a call, if it's still in an abortable state
812  * and return true if the call was aborted, false if it was already complete.
813  */
814 bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
815 			     u32 abort_code, int error, const char *why)
816 {
817 	bool aborted;
818 
819 	_enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
820 
821 	mutex_lock(&call->user_mutex);
822 
823 	aborted = rxrpc_abort_call(why, call, 0, abort_code, error);
824 	if (aborted)
825 		rxrpc_send_abort_packet(call);
826 
827 	mutex_unlock(&call->user_mutex);
828 	return aborted;
829 }
830 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
831 
832 /**
833  * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
834  * @sock: The socket the call is on
835  * @call: The call to be informed
836  * @tx_total_len: The amount of data to be transmitted for this call
837  *
838  * Allow a kernel service to set the total transmit length on a call.  This
839  * allows buffer-to-packet encrypt-and-copy to be performed.
840  *
841  * This function is primarily for use for setting the reply length since the
842  * request length can be set when beginning the call.
843  */
844 void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
845 				s64 tx_total_len)
846 {
847 	WARN_ON(call->tx_total_len != -1);
848 	call->tx_total_len = tx_total_len;
849 }
850 EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);
851