xref: /openbmc/linux/net/rxrpc/sendmsg.c (revision cb1aaebe)
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 (test_bit(RXRPC_CALL_IS_INTR, &call->flags) &&
84 		    timeout == 0 &&
85 		    tx_win == tx_start && signal_pending(current))
86 			return -EINTR;
87 
88 		if (tx_win != tx_start) {
89 			timeout = rtt2;
90 			tx_start = tx_win;
91 		}
92 
93 		trace_rxrpc_transmit(call, rxrpc_transmit_wait);
94 		timeout = schedule_timeout(timeout);
95 	}
96 }
97 
98 /*
99  * wait for space to appear in the transmit/ACK window
100  * - caller holds the socket locked
101  */
102 static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
103 				    struct rxrpc_call *call,
104 				    long *timeo,
105 				    bool waitall)
106 {
107 	DECLARE_WAITQUEUE(myself, current);
108 	int ret;
109 
110 	_enter(",{%u,%u,%u}",
111 	       call->tx_hard_ack, call->tx_top, call->tx_winsize);
112 
113 	add_wait_queue(&call->waitq, &myself);
114 
115 	if (waitall)
116 		ret = rxrpc_wait_for_tx_window_nonintr(rx, call);
117 	else
118 		ret = rxrpc_wait_for_tx_window_intr(rx, call, timeo);
119 
120 	remove_wait_queue(&call->waitq, &myself);
121 	set_current_state(TASK_RUNNING);
122 	_leave(" = %d", ret);
123 	return ret;
124 }
125 
126 /*
127  * Schedule an instant Tx resend.
128  */
129 static inline void rxrpc_instant_resend(struct rxrpc_call *call, int ix)
130 {
131 	spin_lock_bh(&call->lock);
132 
133 	if (call->state < RXRPC_CALL_COMPLETE) {
134 		call->rxtx_annotations[ix] =
135 			(call->rxtx_annotations[ix] & RXRPC_TX_ANNO_LAST) |
136 			RXRPC_TX_ANNO_RETRANS;
137 		if (!test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
138 			rxrpc_queue_call(call);
139 	}
140 
141 	spin_unlock_bh(&call->lock);
142 }
143 
144 /*
145  * Notify the owner of the call that the transmit phase is ended and the last
146  * packet has been queued.
147  */
148 static void rxrpc_notify_end_tx(struct rxrpc_sock *rx, struct rxrpc_call *call,
149 				rxrpc_notify_end_tx_t notify_end_tx)
150 {
151 	if (notify_end_tx)
152 		notify_end_tx(&rx->sk, call, call->user_call_ID);
153 }
154 
155 /*
156  * Queue a DATA packet for transmission, set the resend timeout and send
157  * the packet immediately.  Returns the error from rxrpc_send_data_packet()
158  * in case the caller wants to do something with it.
159  */
160 static int rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
161 			      struct sk_buff *skb, bool last,
162 			      rxrpc_notify_end_tx_t notify_end_tx)
163 {
164 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
165 	unsigned long now;
166 	rxrpc_seq_t seq = sp->hdr.seq;
167 	int ret, ix;
168 	u8 annotation = RXRPC_TX_ANNO_UNACK;
169 
170 	_net("queue skb %p [%d]", skb, seq);
171 
172 	ASSERTCMP(seq, ==, call->tx_top + 1);
173 
174 	if (last)
175 		annotation |= RXRPC_TX_ANNO_LAST;
176 
177 	/* We have to set the timestamp before queueing as the retransmit
178 	 * algorithm can see the packet as soon as we queue it.
179 	 */
180 	skb->tstamp = ktime_get_real();
181 
182 	ix = seq & RXRPC_RXTX_BUFF_MASK;
183 	rxrpc_get_skb(skb, rxrpc_skb_tx_got);
184 	call->rxtx_annotations[ix] = annotation;
185 	smp_wmb();
186 	call->rxtx_buffer[ix] = skb;
187 	call->tx_top = seq;
188 	if (last)
189 		trace_rxrpc_transmit(call, rxrpc_transmit_queue_last);
190 	else
191 		trace_rxrpc_transmit(call, rxrpc_transmit_queue);
192 
193 	if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {
194 		_debug("________awaiting reply/ACK__________");
195 		write_lock_bh(&call->state_lock);
196 		switch (call->state) {
197 		case RXRPC_CALL_CLIENT_SEND_REQUEST:
198 			call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
199 			rxrpc_notify_end_tx(rx, call, notify_end_tx);
200 			break;
201 		case RXRPC_CALL_SERVER_ACK_REQUEST:
202 			call->state = RXRPC_CALL_SERVER_SEND_REPLY;
203 			now = jiffies;
204 			WRITE_ONCE(call->ack_at, now + MAX_JIFFY_OFFSET);
205 			if (call->ackr_reason == RXRPC_ACK_DELAY)
206 				call->ackr_reason = 0;
207 			trace_rxrpc_timer(call, rxrpc_timer_init_for_send_reply, now);
208 			if (!last)
209 				break;
210 			/* Fall through */
211 		case RXRPC_CALL_SERVER_SEND_REPLY:
212 			call->state = RXRPC_CALL_SERVER_AWAIT_ACK;
213 			rxrpc_notify_end_tx(rx, call, notify_end_tx);
214 			break;
215 		default:
216 			break;
217 		}
218 		write_unlock_bh(&call->state_lock);
219 	}
220 
221 	if (seq == 1 && rxrpc_is_client_call(call))
222 		rxrpc_expose_client_call(call);
223 
224 	ret = rxrpc_send_data_packet(call, skb, false);
225 	if (ret < 0) {
226 		switch (ret) {
227 		case -ENETUNREACH:
228 		case -EHOSTUNREACH:
229 		case -ECONNREFUSED:
230 			rxrpc_set_call_completion(call,
231 						  RXRPC_CALL_LOCAL_ERROR,
232 						  0, ret);
233 			goto out;
234 		}
235 		_debug("need instant resend %d", ret);
236 		rxrpc_instant_resend(call, ix);
237 	} else {
238 		unsigned long now = jiffies, resend_at;
239 
240 		if (call->peer->rtt_usage > 1)
241 			resend_at = nsecs_to_jiffies(call->peer->rtt * 3 / 2);
242 		else
243 			resend_at = rxrpc_resend_timeout;
244 		if (resend_at < 1)
245 			resend_at = 1;
246 
247 		resend_at += now;
248 		WRITE_ONCE(call->resend_at, resend_at);
249 		rxrpc_reduce_call_timer(call, resend_at, now,
250 					rxrpc_timer_set_for_send);
251 	}
252 
253 out:
254 	rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
255 	_leave(" = %d", ret);
256 	return ret;
257 }
258 
259 /*
260  * send data through a socket
261  * - must be called in process context
262  * - The caller holds the call user access mutex, but not the socket lock.
263  */
264 static int rxrpc_send_data(struct rxrpc_sock *rx,
265 			   struct rxrpc_call *call,
266 			   struct msghdr *msg, size_t len,
267 			   rxrpc_notify_end_tx_t notify_end_tx)
268 {
269 	struct rxrpc_skb_priv *sp;
270 	struct sk_buff *skb;
271 	struct sock *sk = &rx->sk;
272 	long timeo;
273 	bool more;
274 	int ret, copied;
275 
276 	timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
277 
278 	/* this should be in poll */
279 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
280 
281 	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
282 		return -EPIPE;
283 
284 	more = msg->msg_flags & MSG_MORE;
285 
286 	if (call->tx_total_len != -1) {
287 		if (len > call->tx_total_len)
288 			return -EMSGSIZE;
289 		if (!more && len != call->tx_total_len)
290 			return -EMSGSIZE;
291 	}
292 
293 	skb = call->tx_pending;
294 	call->tx_pending = NULL;
295 	rxrpc_see_skb(skb, rxrpc_skb_tx_seen);
296 
297 	copied = 0;
298 	do {
299 		/* Check to see if there's a ping ACK to reply to. */
300 		if (call->ackr_reason == RXRPC_ACK_PING_RESPONSE)
301 			rxrpc_send_ack_packet(call, false, NULL);
302 
303 		if (!skb) {
304 			size_t size, chunk, max, space;
305 
306 			_debug("alloc");
307 
308 			if (call->tx_top - call->tx_hard_ack >=
309 			    min_t(unsigned int, call->tx_winsize,
310 				  call->cong_cwnd + call->cong_extra)) {
311 				ret = -EAGAIN;
312 				if (msg->msg_flags & MSG_DONTWAIT)
313 					goto maybe_error;
314 				ret = rxrpc_wait_for_tx_window(rx, call,
315 							       &timeo,
316 							       msg->msg_flags & MSG_WAITALL);
317 				if (ret < 0)
318 					goto maybe_error;
319 			}
320 
321 			max = RXRPC_JUMBO_DATALEN;
322 			max -= call->conn->security_size;
323 			max &= ~(call->conn->size_align - 1UL);
324 
325 			chunk = max;
326 			if (chunk > msg_data_left(msg) && !more)
327 				chunk = msg_data_left(msg);
328 
329 			space = chunk + call->conn->size_align;
330 			space &= ~(call->conn->size_align - 1UL);
331 
332 			size = space + call->conn->security_size;
333 
334 			_debug("SIZE: %zu/%zu/%zu", chunk, space, size);
335 
336 			/* create a buffer that we can retain until it's ACK'd */
337 			skb = sock_alloc_send_skb(
338 				sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
339 			if (!skb)
340 				goto maybe_error;
341 
342 			rxrpc_new_skb(skb, rxrpc_skb_tx_new);
343 
344 			_debug("ALLOC SEND %p", skb);
345 
346 			ASSERTCMP(skb->mark, ==, 0);
347 
348 			_debug("HS: %u", call->conn->security_size);
349 			skb_reserve(skb, call->conn->security_size);
350 			skb->len += call->conn->security_size;
351 
352 			sp = rxrpc_skb(skb);
353 			sp->remain = chunk;
354 			if (sp->remain > skb_tailroom(skb))
355 				sp->remain = skb_tailroom(skb);
356 
357 			_net("skb: hr %d, tr %d, hl %d, rm %d",
358 			       skb_headroom(skb),
359 			       skb_tailroom(skb),
360 			       skb_headlen(skb),
361 			       sp->remain);
362 
363 			skb->ip_summed = CHECKSUM_UNNECESSARY;
364 		}
365 
366 		_debug("append");
367 		sp = rxrpc_skb(skb);
368 
369 		/* append next segment of data to the current buffer */
370 		if (msg_data_left(msg) > 0) {
371 			int copy = skb_tailroom(skb);
372 			ASSERTCMP(copy, >, 0);
373 			if (copy > msg_data_left(msg))
374 				copy = msg_data_left(msg);
375 			if (copy > sp->remain)
376 				copy = sp->remain;
377 
378 			_debug("add");
379 			ret = skb_add_data(skb, &msg->msg_iter, copy);
380 			_debug("added");
381 			if (ret < 0)
382 				goto efault;
383 			sp->remain -= copy;
384 			skb->mark += copy;
385 			copied += copy;
386 			if (call->tx_total_len != -1)
387 				call->tx_total_len -= copy;
388 		}
389 
390 		/* check for the far side aborting the call or a network error
391 		 * occurring */
392 		if (call->state == RXRPC_CALL_COMPLETE)
393 			goto call_terminated;
394 
395 		/* add the packet to the send queue if it's now full */
396 		if (sp->remain <= 0 ||
397 		    (msg_data_left(msg) == 0 && !more)) {
398 			struct rxrpc_connection *conn = call->conn;
399 			uint32_t seq;
400 			size_t pad;
401 
402 			/* pad out if we're using security */
403 			if (conn->security_ix) {
404 				pad = conn->security_size + skb->mark;
405 				pad = conn->size_align - pad;
406 				pad &= conn->size_align - 1;
407 				_debug("pad %zu", pad);
408 				if (pad)
409 					skb_put_zero(skb, pad);
410 			}
411 
412 			seq = call->tx_top + 1;
413 
414 			sp->hdr.seq	= seq;
415 			sp->hdr._rsvd	= 0;
416 			sp->hdr.flags	= conn->out_clientflag;
417 
418 			if (msg_data_left(msg) == 0 && !more)
419 				sp->hdr.flags |= RXRPC_LAST_PACKET;
420 			else if (call->tx_top - call->tx_hard_ack <
421 				 call->tx_winsize)
422 				sp->hdr.flags |= RXRPC_MORE_PACKETS;
423 
424 			ret = conn->security->secure_packet(
425 				call, skb, skb->mark, skb->head);
426 			if (ret < 0)
427 				goto out;
428 
429 			ret = rxrpc_queue_packet(rx, call, skb,
430 						 !msg_data_left(msg) && !more,
431 						 notify_end_tx);
432 			/* Should check for failure here */
433 			skb = NULL;
434 		}
435 	} while (msg_data_left(msg) > 0);
436 
437 success:
438 	ret = copied;
439 out:
440 	call->tx_pending = skb;
441 	_leave(" = %d", ret);
442 	return ret;
443 
444 call_terminated:
445 	rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
446 	_leave(" = %d", call->error);
447 	return call->error;
448 
449 maybe_error:
450 	if (copied)
451 		goto success;
452 	goto out;
453 
454 efault:
455 	ret = -EFAULT;
456 	goto out;
457 }
458 
459 /*
460  * extract control messages from the sendmsg() control buffer
461  */
462 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
463 {
464 	struct cmsghdr *cmsg;
465 	bool got_user_ID = false;
466 	int len;
467 
468 	if (msg->msg_controllen == 0)
469 		return -EINVAL;
470 
471 	for_each_cmsghdr(cmsg, msg) {
472 		if (!CMSG_OK(msg, cmsg))
473 			return -EINVAL;
474 
475 		len = cmsg->cmsg_len - sizeof(struct cmsghdr);
476 		_debug("CMSG %d, %d, %d",
477 		       cmsg->cmsg_level, cmsg->cmsg_type, len);
478 
479 		if (cmsg->cmsg_level != SOL_RXRPC)
480 			continue;
481 
482 		switch (cmsg->cmsg_type) {
483 		case RXRPC_USER_CALL_ID:
484 			if (msg->msg_flags & MSG_CMSG_COMPAT) {
485 				if (len != sizeof(u32))
486 					return -EINVAL;
487 				p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
488 			} else {
489 				if (len != sizeof(unsigned long))
490 					return -EINVAL;
491 				p->call.user_call_ID = *(unsigned long *)
492 					CMSG_DATA(cmsg);
493 			}
494 			got_user_ID = true;
495 			break;
496 
497 		case RXRPC_ABORT:
498 			if (p->command != RXRPC_CMD_SEND_DATA)
499 				return -EINVAL;
500 			p->command = RXRPC_CMD_SEND_ABORT;
501 			if (len != sizeof(p->abort_code))
502 				return -EINVAL;
503 			p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
504 			if (p->abort_code == 0)
505 				return -EINVAL;
506 			break;
507 
508 		case RXRPC_ACCEPT:
509 			if (p->command != RXRPC_CMD_SEND_DATA)
510 				return -EINVAL;
511 			p->command = RXRPC_CMD_ACCEPT;
512 			if (len != 0)
513 				return -EINVAL;
514 			break;
515 
516 		case RXRPC_EXCLUSIVE_CALL:
517 			p->exclusive = true;
518 			if (len != 0)
519 				return -EINVAL;
520 			break;
521 
522 		case RXRPC_UPGRADE_SERVICE:
523 			p->upgrade = true;
524 			if (len != 0)
525 				return -EINVAL;
526 			break;
527 
528 		case RXRPC_TX_LENGTH:
529 			if (p->call.tx_total_len != -1 || len != sizeof(__s64))
530 				return -EINVAL;
531 			p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
532 			if (p->call.tx_total_len < 0)
533 				return -EINVAL;
534 			break;
535 
536 		case RXRPC_SET_CALL_TIMEOUT:
537 			if (len & 3 || len < 4 || len > 12)
538 				return -EINVAL;
539 			memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
540 			p->call.nr_timeouts = len / 4;
541 			if (p->call.timeouts.hard > INT_MAX / HZ)
542 				return -ERANGE;
543 			if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
544 				return -ERANGE;
545 			if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
546 				return -ERANGE;
547 			break;
548 
549 		default:
550 			return -EINVAL;
551 		}
552 	}
553 
554 	if (!got_user_ID)
555 		return -EINVAL;
556 	if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
557 		return -EINVAL;
558 	_leave(" = 0");
559 	return 0;
560 }
561 
562 /*
563  * Create a new client call for sendmsg().
564  * - Called with the socket lock held, which it must release.
565  * - If it returns a call, the call's lock will need releasing by the caller.
566  */
567 static struct rxrpc_call *
568 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
569 				  struct rxrpc_send_params *p)
570 	__releases(&rx->sk.sk_lock.slock)
571 	__acquires(&call->user_mutex)
572 {
573 	struct rxrpc_conn_parameters cp;
574 	struct rxrpc_call *call;
575 	struct key *key;
576 
577 	DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
578 
579 	_enter("");
580 
581 	if (!msg->msg_name) {
582 		release_sock(&rx->sk);
583 		return ERR_PTR(-EDESTADDRREQ);
584 	}
585 
586 	key = rx->key;
587 	if (key && !rx->key->payload.data[0])
588 		key = NULL;
589 
590 	memset(&cp, 0, sizeof(cp));
591 	cp.local		= rx->local;
592 	cp.key			= rx->key;
593 	cp.security_level	= rx->min_sec_level;
594 	cp.exclusive		= rx->exclusive | p->exclusive;
595 	cp.upgrade		= p->upgrade;
596 	cp.service_id		= srx->srx_service;
597 	call = rxrpc_new_client_call(rx, &cp, srx, &p->call, GFP_KERNEL,
598 				     atomic_inc_return(&rxrpc_debug_id));
599 	/* The socket is now unlocked */
600 
601 	rxrpc_put_peer(cp.peer);
602 	_leave(" = %p\n", call);
603 	return call;
604 }
605 
606 /*
607  * send a message forming part of a client call through an RxRPC socket
608  * - caller holds the socket locked
609  * - the socket may be either a client socket or a server socket
610  */
611 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
612 	__releases(&rx->sk.sk_lock.slock)
613 	__releases(&call->user_mutex)
614 {
615 	enum rxrpc_call_state state;
616 	struct rxrpc_call *call;
617 	unsigned long now, j;
618 	int ret;
619 
620 	struct rxrpc_send_params p = {
621 		.call.tx_total_len	= -1,
622 		.call.user_call_ID	= 0,
623 		.call.nr_timeouts	= 0,
624 		.call.intr		= true,
625 		.abort_code		= 0,
626 		.command		= RXRPC_CMD_SEND_DATA,
627 		.exclusive		= false,
628 		.upgrade		= false,
629 	};
630 
631 	_enter("");
632 
633 	ret = rxrpc_sendmsg_cmsg(msg, &p);
634 	if (ret < 0)
635 		goto error_release_sock;
636 
637 	if (p.command == RXRPC_CMD_ACCEPT) {
638 		ret = -EINVAL;
639 		if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
640 			goto error_release_sock;
641 		call = rxrpc_accept_call(rx, p.call.user_call_ID, NULL);
642 		/* The socket is now unlocked. */
643 		if (IS_ERR(call))
644 			return PTR_ERR(call);
645 		ret = 0;
646 		goto out_put_unlock;
647 	}
648 
649 	call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
650 	if (!call) {
651 		ret = -EBADSLT;
652 		if (p.command != RXRPC_CMD_SEND_DATA)
653 			goto error_release_sock;
654 		call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
655 		/* The socket is now unlocked... */
656 		if (IS_ERR(call))
657 			return PTR_ERR(call);
658 		/* ... and we have the call lock. */
659 	} else {
660 		switch (READ_ONCE(call->state)) {
661 		case RXRPC_CALL_UNINITIALISED:
662 		case RXRPC_CALL_CLIENT_AWAIT_CONN:
663 		case RXRPC_CALL_SERVER_PREALLOC:
664 		case RXRPC_CALL_SERVER_SECURING:
665 		case RXRPC_CALL_SERVER_ACCEPTING:
666 			ret = -EBUSY;
667 			goto error_release_sock;
668 		default:
669 			break;
670 		}
671 
672 		ret = mutex_lock_interruptible(&call->user_mutex);
673 		release_sock(&rx->sk);
674 		if (ret < 0) {
675 			ret = -ERESTARTSYS;
676 			goto error_put;
677 		}
678 
679 		if (p.call.tx_total_len != -1) {
680 			ret = -EINVAL;
681 			if (call->tx_total_len != -1 ||
682 			    call->tx_pending ||
683 			    call->tx_top != 0)
684 				goto error_put;
685 			call->tx_total_len = p.call.tx_total_len;
686 		}
687 	}
688 
689 	switch (p.call.nr_timeouts) {
690 	case 3:
691 		j = msecs_to_jiffies(p.call.timeouts.normal);
692 		if (p.call.timeouts.normal > 0 && j == 0)
693 			j = 1;
694 		WRITE_ONCE(call->next_rx_timo, j);
695 		/* Fall through */
696 	case 2:
697 		j = msecs_to_jiffies(p.call.timeouts.idle);
698 		if (p.call.timeouts.idle > 0 && j == 0)
699 			j = 1;
700 		WRITE_ONCE(call->next_req_timo, j);
701 		/* Fall through */
702 	case 1:
703 		if (p.call.timeouts.hard > 0) {
704 			j = msecs_to_jiffies(p.call.timeouts.hard);
705 			now = jiffies;
706 			j += now;
707 			WRITE_ONCE(call->expect_term_by, j);
708 			rxrpc_reduce_call_timer(call, j, now,
709 						rxrpc_timer_set_for_hard);
710 		}
711 		break;
712 	}
713 
714 	state = READ_ONCE(call->state);
715 	_debug("CALL %d USR %lx ST %d on CONN %p",
716 	       call->debug_id, call->user_call_ID, state, call->conn);
717 
718 	if (state >= RXRPC_CALL_COMPLETE) {
719 		/* it's too late for this call */
720 		ret = -ESHUTDOWN;
721 	} else if (p.command == RXRPC_CMD_SEND_ABORT) {
722 		ret = 0;
723 		if (rxrpc_abort_call("CMD", call, 0, p.abort_code, -ECONNABORTED))
724 			ret = rxrpc_send_abort_packet(call);
725 	} else if (p.command != RXRPC_CMD_SEND_DATA) {
726 		ret = -EINVAL;
727 	} else if (rxrpc_is_client_call(call) &&
728 		   state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
729 		/* request phase complete for this client call */
730 		ret = -EPROTO;
731 	} else if (rxrpc_is_service_call(call) &&
732 		   state != RXRPC_CALL_SERVER_ACK_REQUEST &&
733 		   state != RXRPC_CALL_SERVER_SEND_REPLY) {
734 		/* Reply phase not begun or not complete for service call. */
735 		ret = -EPROTO;
736 	} else {
737 		ret = rxrpc_send_data(rx, call, msg, len, NULL);
738 	}
739 
740 out_put_unlock:
741 	mutex_unlock(&call->user_mutex);
742 error_put:
743 	rxrpc_put_call(call, rxrpc_call_put);
744 	_leave(" = %d", ret);
745 	return ret;
746 
747 error_release_sock:
748 	release_sock(&rx->sk);
749 	return ret;
750 }
751 
752 /**
753  * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
754  * @sock: The socket the call is on
755  * @call: The call to send data through
756  * @msg: The data to send
757  * @len: The amount of data to send
758  * @notify_end_tx: Notification that the last packet is queued.
759  *
760  * Allow a kernel service to send data on a call.  The call must be in an state
761  * appropriate to sending data.  No control data should be supplied in @msg,
762  * nor should an address be supplied.  MSG_MORE should be flagged if there's
763  * more data to come, otherwise this data will end the transmission phase.
764  */
765 int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
766 			   struct msghdr *msg, size_t len,
767 			   rxrpc_notify_end_tx_t notify_end_tx)
768 {
769 	int ret;
770 
771 	_enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
772 
773 	ASSERTCMP(msg->msg_name, ==, NULL);
774 	ASSERTCMP(msg->msg_control, ==, NULL);
775 
776 	mutex_lock(&call->user_mutex);
777 
778 	_debug("CALL %d USR %lx ST %d on CONN %p",
779 	       call->debug_id, call->user_call_ID, call->state, call->conn);
780 
781 	switch (READ_ONCE(call->state)) {
782 	case RXRPC_CALL_CLIENT_SEND_REQUEST:
783 	case RXRPC_CALL_SERVER_ACK_REQUEST:
784 	case RXRPC_CALL_SERVER_SEND_REPLY:
785 		ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
786 				      notify_end_tx);
787 		break;
788 	case RXRPC_CALL_COMPLETE:
789 		read_lock_bh(&call->state_lock);
790 		ret = call->error;
791 		read_unlock_bh(&call->state_lock);
792 		break;
793 	default:
794 		/* Request phase complete for this client call */
795 		trace_rxrpc_rx_eproto(call, 0, tracepoint_string("late_send"));
796 		ret = -EPROTO;
797 		break;
798 	}
799 
800 	mutex_unlock(&call->user_mutex);
801 	_leave(" = %d", ret);
802 	return ret;
803 }
804 EXPORT_SYMBOL(rxrpc_kernel_send_data);
805 
806 /**
807  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
808  * @sock: The socket the call is on
809  * @call: The call to be aborted
810  * @abort_code: The abort code to stick into the ABORT packet
811  * @error: Local error value
812  * @why: 3-char string indicating why.
813  *
814  * Allow a kernel service to abort a call, if it's still in an abortable state
815  * and return true if the call was aborted, false if it was already complete.
816  */
817 bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
818 			     u32 abort_code, int error, const char *why)
819 {
820 	bool aborted;
821 
822 	_enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
823 
824 	mutex_lock(&call->user_mutex);
825 
826 	aborted = rxrpc_abort_call(why, call, 0, abort_code, error);
827 	if (aborted)
828 		rxrpc_send_abort_packet(call);
829 
830 	mutex_unlock(&call->user_mutex);
831 	return aborted;
832 }
833 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
834 
835 /**
836  * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
837  * @sock: The socket the call is on
838  * @call: The call to be informed
839  * @tx_total_len: The amount of data to be transmitted for this call
840  *
841  * Allow a kernel service to set the total transmit length on a call.  This
842  * allows buffer-to-packet encrypt-and-copy to be performed.
843  *
844  * This function is primarily for use for setting the reply length since the
845  * request length can be set when beginning the call.
846  */
847 void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
848 				s64 tx_total_len)
849 {
850 	WARN_ON(call->tx_total_len != -1);
851 	call->tx_total_len = tx_total_len;
852 }
853 EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);
854