xref: /openbmc/linux/net/rxrpc/sendmsg.c (revision 62e59c4e)
1 /* AF_RXRPC sendmsg() implementation.
2  *
3  * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
4  * Written by David Howells (dhowells@redhat.com)
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public Licence
8  * as published by the Free Software Foundation; either version
9  * 2 of the Licence, or (at your option) any later version.
10  */
11 
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13 
14 #include <linux/net.h>
15 #include <linux/gfp.h>
16 #include <linux/skbuff.h>
17 #include <linux/export.h>
18 #include <linux/sched/signal.h>
19 
20 #include <net/sock.h>
21 #include <net/af_rxrpc.h>
22 #include "ar-internal.h"
23 
24 /*
25  * Wait for space to appear in the Tx queue or a signal to occur.
26  */
27 static int rxrpc_wait_for_tx_window_intr(struct rxrpc_sock *rx,
28 					 struct rxrpc_call *call,
29 					 long *timeo)
30 {
31 	for (;;) {
32 		set_current_state(TASK_INTERRUPTIBLE);
33 		if (call->tx_top - call->tx_hard_ack <
34 		    min_t(unsigned int, call->tx_winsize,
35 			  call->cong_cwnd + call->cong_extra))
36 			return 0;
37 
38 		if (call->state >= RXRPC_CALL_COMPLETE)
39 			return call->error;
40 
41 		if (signal_pending(current))
42 			return sock_intr_errno(*timeo);
43 
44 		trace_rxrpc_transmit(call, rxrpc_transmit_wait);
45 		mutex_unlock(&call->user_mutex);
46 		*timeo = schedule_timeout(*timeo);
47 		if (mutex_lock_interruptible(&call->user_mutex) < 0)
48 			return sock_intr_errno(*timeo);
49 	}
50 }
51 
52 /*
53  * Wait for space to appear in the Tx queue uninterruptibly, but with
54  * a timeout of 2*RTT if no progress was made and a signal occurred.
55  */
56 static int rxrpc_wait_for_tx_window_nonintr(struct rxrpc_sock *rx,
57 					    struct rxrpc_call *call)
58 {
59 	rxrpc_seq_t tx_start, tx_win;
60 	signed long rtt2, timeout;
61 	u64 rtt;
62 
63 	rtt = READ_ONCE(call->peer->rtt);
64 	rtt2 = nsecs_to_jiffies64(rtt) * 2;
65 	if (rtt2 < 1)
66 		rtt2 = 1;
67 
68 	timeout = rtt2;
69 	tx_start = READ_ONCE(call->tx_hard_ack);
70 
71 	for (;;) {
72 		set_current_state(TASK_UNINTERRUPTIBLE);
73 
74 		tx_win = READ_ONCE(call->tx_hard_ack);
75 		if (call->tx_top - tx_win <
76 		    min_t(unsigned int, call->tx_winsize,
77 			  call->cong_cwnd + call->cong_extra))
78 			return 0;
79 
80 		if (call->state >= RXRPC_CALL_COMPLETE)
81 			return call->error;
82 
83 		if (timeout == 0 &&
84 		    tx_win == tx_start && signal_pending(current))
85 			return -EINTR;
86 
87 		if (tx_win != tx_start) {
88 			timeout = rtt2;
89 			tx_start = tx_win;
90 		}
91 
92 		trace_rxrpc_transmit(call, rxrpc_transmit_wait);
93 		timeout = schedule_timeout(timeout);
94 	}
95 }
96 
97 /*
98  * wait for space to appear in the transmit/ACK window
99  * - caller holds the socket locked
100  */
101 static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
102 				    struct rxrpc_call *call,
103 				    long *timeo,
104 				    bool waitall)
105 {
106 	DECLARE_WAITQUEUE(myself, current);
107 	int ret;
108 
109 	_enter(",{%u,%u,%u}",
110 	       call->tx_hard_ack, call->tx_top, call->tx_winsize);
111 
112 	add_wait_queue(&call->waitq, &myself);
113 
114 	if (waitall)
115 		ret = rxrpc_wait_for_tx_window_nonintr(rx, call);
116 	else
117 		ret = rxrpc_wait_for_tx_window_intr(rx, call, timeo);
118 
119 	remove_wait_queue(&call->waitq, &myself);
120 	set_current_state(TASK_RUNNING);
121 	_leave(" = %d", ret);
122 	return ret;
123 }
124 
125 /*
126  * Schedule an instant Tx resend.
127  */
128 static inline void rxrpc_instant_resend(struct rxrpc_call *call, int ix)
129 {
130 	spin_lock_bh(&call->lock);
131 
132 	if (call->state < RXRPC_CALL_COMPLETE) {
133 		call->rxtx_annotations[ix] =
134 			(call->rxtx_annotations[ix] & RXRPC_TX_ANNO_LAST) |
135 			RXRPC_TX_ANNO_RETRANS;
136 		if (!test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
137 			rxrpc_queue_call(call);
138 	}
139 
140 	spin_unlock_bh(&call->lock);
141 }
142 
143 /*
144  * Notify the owner of the call that the transmit phase is ended and the last
145  * packet has been queued.
146  */
147 static void rxrpc_notify_end_tx(struct rxrpc_sock *rx, struct rxrpc_call *call,
148 				rxrpc_notify_end_tx_t notify_end_tx)
149 {
150 	if (notify_end_tx)
151 		notify_end_tx(&rx->sk, call, call->user_call_ID);
152 }
153 
154 /*
155  * Queue a DATA packet for transmission, set the resend timeout and send
156  * the packet immediately.  Returns the error from rxrpc_send_data_packet()
157  * in case the caller wants to do something with it.
158  */
159 static int rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
160 			      struct sk_buff *skb, bool last,
161 			      rxrpc_notify_end_tx_t notify_end_tx)
162 {
163 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
164 	unsigned long now;
165 	rxrpc_seq_t seq = sp->hdr.seq;
166 	int ret, ix;
167 	u8 annotation = RXRPC_TX_ANNO_UNACK;
168 
169 	_net("queue skb %p [%d]", skb, seq);
170 
171 	ASSERTCMP(seq, ==, call->tx_top + 1);
172 
173 	if (last)
174 		annotation |= RXRPC_TX_ANNO_LAST;
175 
176 	/* We have to set the timestamp before queueing as the retransmit
177 	 * algorithm can see the packet as soon as we queue it.
178 	 */
179 	skb->tstamp = ktime_get_real();
180 
181 	ix = seq & RXRPC_RXTX_BUFF_MASK;
182 	rxrpc_get_skb(skb, rxrpc_skb_tx_got);
183 	call->rxtx_annotations[ix] = annotation;
184 	smp_wmb();
185 	call->rxtx_buffer[ix] = skb;
186 	call->tx_top = seq;
187 	if (last)
188 		trace_rxrpc_transmit(call, rxrpc_transmit_queue_last);
189 	else
190 		trace_rxrpc_transmit(call, rxrpc_transmit_queue);
191 
192 	if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {
193 		_debug("________awaiting reply/ACK__________");
194 		write_lock_bh(&call->state_lock);
195 		switch (call->state) {
196 		case RXRPC_CALL_CLIENT_SEND_REQUEST:
197 			call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
198 			rxrpc_notify_end_tx(rx, call, notify_end_tx);
199 			break;
200 		case RXRPC_CALL_SERVER_ACK_REQUEST:
201 			call->state = RXRPC_CALL_SERVER_SEND_REPLY;
202 			now = jiffies;
203 			WRITE_ONCE(call->ack_at, now + MAX_JIFFY_OFFSET);
204 			if (call->ackr_reason == RXRPC_ACK_DELAY)
205 				call->ackr_reason = 0;
206 			trace_rxrpc_timer(call, rxrpc_timer_init_for_send_reply, now);
207 			if (!last)
208 				break;
209 			/* Fall through */
210 		case RXRPC_CALL_SERVER_SEND_REPLY:
211 			call->state = RXRPC_CALL_SERVER_AWAIT_ACK;
212 			rxrpc_notify_end_tx(rx, call, notify_end_tx);
213 			break;
214 		default:
215 			break;
216 		}
217 		write_unlock_bh(&call->state_lock);
218 	}
219 
220 	if (seq == 1 && rxrpc_is_client_call(call))
221 		rxrpc_expose_client_call(call);
222 
223 	ret = rxrpc_send_data_packet(call, skb, false);
224 	if (ret < 0) {
225 		switch (ret) {
226 		case -ENETUNREACH:
227 		case -EHOSTUNREACH:
228 		case -ECONNREFUSED:
229 			rxrpc_set_call_completion(call,
230 						  RXRPC_CALL_LOCAL_ERROR,
231 						  0, ret);
232 			goto out;
233 		}
234 		_debug("need instant resend %d", ret);
235 		rxrpc_instant_resend(call, ix);
236 	} else {
237 		unsigned long now = jiffies, resend_at;
238 
239 		if (call->peer->rtt_usage > 1)
240 			resend_at = nsecs_to_jiffies(call->peer->rtt * 3 / 2);
241 		else
242 			resend_at = rxrpc_resend_timeout;
243 		if (resend_at < 1)
244 			resend_at = 1;
245 
246 		resend_at += now;
247 		WRITE_ONCE(call->resend_at, resend_at);
248 		rxrpc_reduce_call_timer(call, resend_at, now,
249 					rxrpc_timer_set_for_send);
250 	}
251 
252 out:
253 	rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
254 	_leave(" = %d", ret);
255 	return ret;
256 }
257 
258 /*
259  * send data through a socket
260  * - must be called in process context
261  * - The caller holds the call user access mutex, but not the socket lock.
262  */
263 static int rxrpc_send_data(struct rxrpc_sock *rx,
264 			   struct rxrpc_call *call,
265 			   struct msghdr *msg, size_t len,
266 			   rxrpc_notify_end_tx_t notify_end_tx)
267 {
268 	struct rxrpc_skb_priv *sp;
269 	struct sk_buff *skb;
270 	struct sock *sk = &rx->sk;
271 	long timeo;
272 	bool more;
273 	int ret, copied;
274 
275 	timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
276 
277 	/* this should be in poll */
278 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
279 
280 	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
281 		return -EPIPE;
282 
283 	more = msg->msg_flags & MSG_MORE;
284 
285 	if (call->tx_total_len != -1) {
286 		if (len > call->tx_total_len)
287 			return -EMSGSIZE;
288 		if (!more && len != call->tx_total_len)
289 			return -EMSGSIZE;
290 	}
291 
292 	skb = call->tx_pending;
293 	call->tx_pending = NULL;
294 	rxrpc_see_skb(skb, rxrpc_skb_tx_seen);
295 
296 	copied = 0;
297 	do {
298 		/* Check to see if there's a ping ACK to reply to. */
299 		if (call->ackr_reason == RXRPC_ACK_PING_RESPONSE)
300 			rxrpc_send_ack_packet(call, false, NULL);
301 
302 		if (!skb) {
303 			size_t size, chunk, max, space;
304 
305 			_debug("alloc");
306 
307 			if (call->tx_top - call->tx_hard_ack >=
308 			    min_t(unsigned int, call->tx_winsize,
309 				  call->cong_cwnd + call->cong_extra)) {
310 				ret = -EAGAIN;
311 				if (msg->msg_flags & MSG_DONTWAIT)
312 					goto maybe_error;
313 				ret = rxrpc_wait_for_tx_window(rx, call,
314 							       &timeo,
315 							       msg->msg_flags & MSG_WAITALL);
316 				if (ret < 0)
317 					goto maybe_error;
318 			}
319 
320 			max = RXRPC_JUMBO_DATALEN;
321 			max -= call->conn->security_size;
322 			max &= ~(call->conn->size_align - 1UL);
323 
324 			chunk = max;
325 			if (chunk > msg_data_left(msg) && !more)
326 				chunk = msg_data_left(msg);
327 
328 			space = chunk + call->conn->size_align;
329 			space &= ~(call->conn->size_align - 1UL);
330 
331 			size = space + call->conn->security_size;
332 
333 			_debug("SIZE: %zu/%zu/%zu", chunk, space, size);
334 
335 			/* create a buffer that we can retain until it's ACK'd */
336 			skb = sock_alloc_send_skb(
337 				sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
338 			if (!skb)
339 				goto maybe_error;
340 
341 			rxrpc_new_skb(skb, rxrpc_skb_tx_new);
342 
343 			_debug("ALLOC SEND %p", skb);
344 
345 			ASSERTCMP(skb->mark, ==, 0);
346 
347 			_debug("HS: %u", call->conn->security_size);
348 			skb_reserve(skb, call->conn->security_size);
349 			skb->len += call->conn->security_size;
350 
351 			sp = rxrpc_skb(skb);
352 			sp->remain = chunk;
353 			if (sp->remain > skb_tailroom(skb))
354 				sp->remain = skb_tailroom(skb);
355 
356 			_net("skb: hr %d, tr %d, hl %d, rm %d",
357 			       skb_headroom(skb),
358 			       skb_tailroom(skb),
359 			       skb_headlen(skb),
360 			       sp->remain);
361 
362 			skb->ip_summed = CHECKSUM_UNNECESSARY;
363 		}
364 
365 		_debug("append");
366 		sp = rxrpc_skb(skb);
367 
368 		/* append next segment of data to the current buffer */
369 		if (msg_data_left(msg) > 0) {
370 			int copy = skb_tailroom(skb);
371 			ASSERTCMP(copy, >, 0);
372 			if (copy > msg_data_left(msg))
373 				copy = msg_data_left(msg);
374 			if (copy > sp->remain)
375 				copy = sp->remain;
376 
377 			_debug("add");
378 			ret = skb_add_data(skb, &msg->msg_iter, copy);
379 			_debug("added");
380 			if (ret < 0)
381 				goto efault;
382 			sp->remain -= copy;
383 			skb->mark += copy;
384 			copied += copy;
385 			if (call->tx_total_len != -1)
386 				call->tx_total_len -= copy;
387 		}
388 
389 		/* check for the far side aborting the call or a network error
390 		 * occurring */
391 		if (call->state == RXRPC_CALL_COMPLETE)
392 			goto call_terminated;
393 
394 		/* add the packet to the send queue if it's now full */
395 		if (sp->remain <= 0 ||
396 		    (msg_data_left(msg) == 0 && !more)) {
397 			struct rxrpc_connection *conn = call->conn;
398 			uint32_t seq;
399 			size_t pad;
400 
401 			/* pad out if we're using security */
402 			if (conn->security_ix) {
403 				pad = conn->security_size + skb->mark;
404 				pad = conn->size_align - pad;
405 				pad &= conn->size_align - 1;
406 				_debug("pad %zu", pad);
407 				if (pad)
408 					skb_put_zero(skb, pad);
409 			}
410 
411 			seq = call->tx_top + 1;
412 
413 			sp->hdr.seq	= seq;
414 			sp->hdr._rsvd	= 0;
415 			sp->hdr.flags	= conn->out_clientflag;
416 
417 			if (msg_data_left(msg) == 0 && !more)
418 				sp->hdr.flags |= RXRPC_LAST_PACKET;
419 			else if (call->tx_top - call->tx_hard_ack <
420 				 call->tx_winsize)
421 				sp->hdr.flags |= RXRPC_MORE_PACKETS;
422 
423 			ret = conn->security->secure_packet(
424 				call, skb, skb->mark, skb->head);
425 			if (ret < 0)
426 				goto out;
427 
428 			ret = rxrpc_queue_packet(rx, call, skb,
429 						 !msg_data_left(msg) && !more,
430 						 notify_end_tx);
431 			/* Should check for failure here */
432 			skb = NULL;
433 		}
434 	} while (msg_data_left(msg) > 0);
435 
436 success:
437 	ret = copied;
438 out:
439 	call->tx_pending = skb;
440 	_leave(" = %d", ret);
441 	return ret;
442 
443 call_terminated:
444 	rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
445 	_leave(" = %d", call->error);
446 	return call->error;
447 
448 maybe_error:
449 	if (copied)
450 		goto success;
451 	goto out;
452 
453 efault:
454 	ret = -EFAULT;
455 	goto out;
456 }
457 
458 /*
459  * extract control messages from the sendmsg() control buffer
460  */
461 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
462 {
463 	struct cmsghdr *cmsg;
464 	bool got_user_ID = false;
465 	int len;
466 
467 	if (msg->msg_controllen == 0)
468 		return -EINVAL;
469 
470 	for_each_cmsghdr(cmsg, msg) {
471 		if (!CMSG_OK(msg, cmsg))
472 			return -EINVAL;
473 
474 		len = cmsg->cmsg_len - sizeof(struct cmsghdr);
475 		_debug("CMSG %d, %d, %d",
476 		       cmsg->cmsg_level, cmsg->cmsg_type, len);
477 
478 		if (cmsg->cmsg_level != SOL_RXRPC)
479 			continue;
480 
481 		switch (cmsg->cmsg_type) {
482 		case RXRPC_USER_CALL_ID:
483 			if (msg->msg_flags & MSG_CMSG_COMPAT) {
484 				if (len != sizeof(u32))
485 					return -EINVAL;
486 				p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
487 			} else {
488 				if (len != sizeof(unsigned long))
489 					return -EINVAL;
490 				p->call.user_call_ID = *(unsigned long *)
491 					CMSG_DATA(cmsg);
492 			}
493 			got_user_ID = true;
494 			break;
495 
496 		case RXRPC_ABORT:
497 			if (p->command != RXRPC_CMD_SEND_DATA)
498 				return -EINVAL;
499 			p->command = RXRPC_CMD_SEND_ABORT;
500 			if (len != sizeof(p->abort_code))
501 				return -EINVAL;
502 			p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
503 			if (p->abort_code == 0)
504 				return -EINVAL;
505 			break;
506 
507 		case RXRPC_ACCEPT:
508 			if (p->command != RXRPC_CMD_SEND_DATA)
509 				return -EINVAL;
510 			p->command = RXRPC_CMD_ACCEPT;
511 			if (len != 0)
512 				return -EINVAL;
513 			break;
514 
515 		case RXRPC_EXCLUSIVE_CALL:
516 			p->exclusive = true;
517 			if (len != 0)
518 				return -EINVAL;
519 			break;
520 
521 		case RXRPC_UPGRADE_SERVICE:
522 			p->upgrade = true;
523 			if (len != 0)
524 				return -EINVAL;
525 			break;
526 
527 		case RXRPC_TX_LENGTH:
528 			if (p->call.tx_total_len != -1 || len != sizeof(__s64))
529 				return -EINVAL;
530 			p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
531 			if (p->call.tx_total_len < 0)
532 				return -EINVAL;
533 			break;
534 
535 		case RXRPC_SET_CALL_TIMEOUT:
536 			if (len & 3 || len < 4 || len > 12)
537 				return -EINVAL;
538 			memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
539 			p->call.nr_timeouts = len / 4;
540 			if (p->call.timeouts.hard > INT_MAX / HZ)
541 				return -ERANGE;
542 			if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
543 				return -ERANGE;
544 			if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
545 				return -ERANGE;
546 			break;
547 
548 		default:
549 			return -EINVAL;
550 		}
551 	}
552 
553 	if (!got_user_ID)
554 		return -EINVAL;
555 	if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
556 		return -EINVAL;
557 	_leave(" = 0");
558 	return 0;
559 }
560 
561 /*
562  * Create a new client call for sendmsg().
563  * - Called with the socket lock held, which it must release.
564  * - If it returns a call, the call's lock will need releasing by the caller.
565  */
566 static struct rxrpc_call *
567 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
568 				  struct rxrpc_send_params *p)
569 	__releases(&rx->sk.sk_lock.slock)
570 	__acquires(&call->user_mutex)
571 {
572 	struct rxrpc_conn_parameters cp;
573 	struct rxrpc_call *call;
574 	struct key *key;
575 
576 	DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
577 
578 	_enter("");
579 
580 	if (!msg->msg_name) {
581 		release_sock(&rx->sk);
582 		return ERR_PTR(-EDESTADDRREQ);
583 	}
584 
585 	key = rx->key;
586 	if (key && !rx->key->payload.data[0])
587 		key = NULL;
588 
589 	memset(&cp, 0, sizeof(cp));
590 	cp.local		= rx->local;
591 	cp.key			= rx->key;
592 	cp.security_level	= rx->min_sec_level;
593 	cp.exclusive		= rx->exclusive | p->exclusive;
594 	cp.upgrade		= p->upgrade;
595 	cp.service_id		= srx->srx_service;
596 	call = rxrpc_new_client_call(rx, &cp, srx, &p->call, GFP_KERNEL,
597 				     atomic_inc_return(&rxrpc_debug_id));
598 	/* The socket is now unlocked */
599 
600 	rxrpc_put_peer(cp.peer);
601 	_leave(" = %p\n", call);
602 	return call;
603 }
604 
605 /*
606  * send a message forming part of a client call through an RxRPC socket
607  * - caller holds the socket locked
608  * - the socket may be either a client socket or a server socket
609  */
610 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
611 	__releases(&rx->sk.sk_lock.slock)
612 	__releases(&call->user_mutex)
613 {
614 	enum rxrpc_call_state state;
615 	struct rxrpc_call *call;
616 	unsigned long now, j;
617 	int ret;
618 
619 	struct rxrpc_send_params p = {
620 		.call.tx_total_len	= -1,
621 		.call.user_call_ID	= 0,
622 		.call.nr_timeouts	= 0,
623 		.abort_code		= 0,
624 		.command		= RXRPC_CMD_SEND_DATA,
625 		.exclusive		= false,
626 		.upgrade		= false,
627 	};
628 
629 	_enter("");
630 
631 	ret = rxrpc_sendmsg_cmsg(msg, &p);
632 	if (ret < 0)
633 		goto error_release_sock;
634 
635 	if (p.command == RXRPC_CMD_ACCEPT) {
636 		ret = -EINVAL;
637 		if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
638 			goto error_release_sock;
639 		call = rxrpc_accept_call(rx, p.call.user_call_ID, NULL);
640 		/* The socket is now unlocked. */
641 		if (IS_ERR(call))
642 			return PTR_ERR(call);
643 		ret = 0;
644 		goto out_put_unlock;
645 	}
646 
647 	call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
648 	if (!call) {
649 		ret = -EBADSLT;
650 		if (p.command != RXRPC_CMD_SEND_DATA)
651 			goto error_release_sock;
652 		call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
653 		/* The socket is now unlocked... */
654 		if (IS_ERR(call))
655 			return PTR_ERR(call);
656 		/* ... and we have the call lock. */
657 	} else {
658 		switch (READ_ONCE(call->state)) {
659 		case RXRPC_CALL_UNINITIALISED:
660 		case RXRPC_CALL_CLIENT_AWAIT_CONN:
661 		case RXRPC_CALL_SERVER_PREALLOC:
662 		case RXRPC_CALL_SERVER_SECURING:
663 		case RXRPC_CALL_SERVER_ACCEPTING:
664 			ret = -EBUSY;
665 			goto error_release_sock;
666 		default:
667 			break;
668 		}
669 
670 		ret = mutex_lock_interruptible(&call->user_mutex);
671 		release_sock(&rx->sk);
672 		if (ret < 0) {
673 			ret = -ERESTARTSYS;
674 			goto error_put;
675 		}
676 
677 		if (p.call.tx_total_len != -1) {
678 			ret = -EINVAL;
679 			if (call->tx_total_len != -1 ||
680 			    call->tx_pending ||
681 			    call->tx_top != 0)
682 				goto error_put;
683 			call->tx_total_len = p.call.tx_total_len;
684 		}
685 	}
686 
687 	switch (p.call.nr_timeouts) {
688 	case 3:
689 		j = msecs_to_jiffies(p.call.timeouts.normal);
690 		if (p.call.timeouts.normal > 0 && j == 0)
691 			j = 1;
692 		WRITE_ONCE(call->next_rx_timo, j);
693 		/* Fall through */
694 	case 2:
695 		j = msecs_to_jiffies(p.call.timeouts.idle);
696 		if (p.call.timeouts.idle > 0 && j == 0)
697 			j = 1;
698 		WRITE_ONCE(call->next_req_timo, j);
699 		/* Fall through */
700 	case 1:
701 		if (p.call.timeouts.hard > 0) {
702 			j = msecs_to_jiffies(p.call.timeouts.hard);
703 			now = jiffies;
704 			j += now;
705 			WRITE_ONCE(call->expect_term_by, j);
706 			rxrpc_reduce_call_timer(call, j, now,
707 						rxrpc_timer_set_for_hard);
708 		}
709 		break;
710 	}
711 
712 	state = READ_ONCE(call->state);
713 	_debug("CALL %d USR %lx ST %d on CONN %p",
714 	       call->debug_id, call->user_call_ID, state, call->conn);
715 
716 	if (state >= RXRPC_CALL_COMPLETE) {
717 		/* it's too late for this call */
718 		ret = -ESHUTDOWN;
719 	} else if (p.command == RXRPC_CMD_SEND_ABORT) {
720 		ret = 0;
721 		if (rxrpc_abort_call("CMD", call, 0, p.abort_code, -ECONNABORTED))
722 			ret = rxrpc_send_abort_packet(call);
723 	} else if (p.command != RXRPC_CMD_SEND_DATA) {
724 		ret = -EINVAL;
725 	} else if (rxrpc_is_client_call(call) &&
726 		   state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
727 		/* request phase complete for this client call */
728 		ret = -EPROTO;
729 	} else if (rxrpc_is_service_call(call) &&
730 		   state != RXRPC_CALL_SERVER_ACK_REQUEST &&
731 		   state != RXRPC_CALL_SERVER_SEND_REPLY) {
732 		/* Reply phase not begun or not complete for service call. */
733 		ret = -EPROTO;
734 	} else {
735 		ret = rxrpc_send_data(rx, call, msg, len, NULL);
736 	}
737 
738 out_put_unlock:
739 	mutex_unlock(&call->user_mutex);
740 error_put:
741 	rxrpc_put_call(call, rxrpc_call_put);
742 	_leave(" = %d", ret);
743 	return ret;
744 
745 error_release_sock:
746 	release_sock(&rx->sk);
747 	return ret;
748 }
749 
750 /**
751  * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
752  * @sock: The socket the call is on
753  * @call: The call to send data through
754  * @msg: The data to send
755  * @len: The amount of data to send
756  * @notify_end_tx: Notification that the last packet is queued.
757  *
758  * Allow a kernel service to send data on a call.  The call must be in an state
759  * appropriate to sending data.  No control data should be supplied in @msg,
760  * nor should an address be supplied.  MSG_MORE should be flagged if there's
761  * more data to come, otherwise this data will end the transmission phase.
762  */
763 int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
764 			   struct msghdr *msg, size_t len,
765 			   rxrpc_notify_end_tx_t notify_end_tx)
766 {
767 	int ret;
768 
769 	_enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
770 
771 	ASSERTCMP(msg->msg_name, ==, NULL);
772 	ASSERTCMP(msg->msg_control, ==, NULL);
773 
774 	mutex_lock(&call->user_mutex);
775 
776 	_debug("CALL %d USR %lx ST %d on CONN %p",
777 	       call->debug_id, call->user_call_ID, call->state, call->conn);
778 
779 	switch (READ_ONCE(call->state)) {
780 	case RXRPC_CALL_CLIENT_SEND_REQUEST:
781 	case RXRPC_CALL_SERVER_ACK_REQUEST:
782 	case RXRPC_CALL_SERVER_SEND_REPLY:
783 		ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
784 				      notify_end_tx);
785 		break;
786 	case RXRPC_CALL_COMPLETE:
787 		read_lock_bh(&call->state_lock);
788 		ret = call->error;
789 		read_unlock_bh(&call->state_lock);
790 		break;
791 	default:
792 		/* Request phase complete for this client call */
793 		trace_rxrpc_rx_eproto(call, 0, tracepoint_string("late_send"));
794 		ret = -EPROTO;
795 		break;
796 	}
797 
798 	mutex_unlock(&call->user_mutex);
799 	_leave(" = %d", ret);
800 	return ret;
801 }
802 EXPORT_SYMBOL(rxrpc_kernel_send_data);
803 
804 /**
805  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
806  * @sock: The socket the call is on
807  * @call: The call to be aborted
808  * @abort_code: The abort code to stick into the ABORT packet
809  * @error: Local error value
810  * @why: 3-char string indicating why.
811  *
812  * Allow a kernel service to abort a call, if it's still in an abortable state
813  * and return true if the call was aborted, false if it was already complete.
814  */
815 bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
816 			     u32 abort_code, int error, const char *why)
817 {
818 	bool aborted;
819 
820 	_enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
821 
822 	mutex_lock(&call->user_mutex);
823 
824 	aborted = rxrpc_abort_call(why, call, 0, abort_code, error);
825 	if (aborted)
826 		rxrpc_send_abort_packet(call);
827 
828 	mutex_unlock(&call->user_mutex);
829 	return aborted;
830 }
831 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
832 
833 /**
834  * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
835  * @sock: The socket the call is on
836  * @call: The call to be informed
837  * @tx_total_len: The amount of data to be transmitted for this call
838  *
839  * Allow a kernel service to set the total transmit length on a call.  This
840  * allows buffer-to-packet encrypt-and-copy to be performed.
841  *
842  * This function is primarily for use for setting the reply length since the
843  * request length can be set when beginning the call.
844  */
845 void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
846 				s64 tx_total_len)
847 {
848 	WARN_ON(call->tx_total_len != -1);
849 	call->tx_total_len = tx_total_len;
850 }
851 EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);
852