xref: /openbmc/linux/net/rxrpc/sendmsg.c (revision 2359ccdd)
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 the
156  * packet immediately
157  */
158 static void rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
159 			       struct sk_buff *skb, bool last,
160 			       rxrpc_notify_end_tx_t notify_end_tx)
161 {
162 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
163 	unsigned long now;
164 	rxrpc_seq_t seq = sp->hdr.seq;
165 	int ret, ix;
166 	u8 annotation = RXRPC_TX_ANNO_UNACK;
167 
168 	_net("queue skb %p [%d]", skb, seq);
169 
170 	ASSERTCMP(seq, ==, call->tx_top + 1);
171 
172 	if (last) {
173 		annotation |= RXRPC_TX_ANNO_LAST;
174 		set_bit(RXRPC_CALL_TX_LASTQ, &call->flags);
175 	}
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 		_debug("need instant resend %d", ret);
227 		rxrpc_instant_resend(call, ix);
228 	} else {
229 		unsigned long now = jiffies, resend_at;
230 
231 		if (call->peer->rtt_usage > 1)
232 			resend_at = nsecs_to_jiffies(call->peer->rtt * 3 / 2);
233 		else
234 			resend_at = rxrpc_resend_timeout;
235 		if (resend_at < 1)
236 			resend_at = 1;
237 
238 		resend_at += now;
239 		WRITE_ONCE(call->resend_at, resend_at);
240 		rxrpc_reduce_call_timer(call, resend_at, now,
241 					rxrpc_timer_set_for_send);
242 	}
243 
244 	rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
245 	_leave("");
246 }
247 
248 /*
249  * send data through a socket
250  * - must be called in process context
251  * - The caller holds the call user access mutex, but not the socket lock.
252  */
253 static int rxrpc_send_data(struct rxrpc_sock *rx,
254 			   struct rxrpc_call *call,
255 			   struct msghdr *msg, size_t len,
256 			   rxrpc_notify_end_tx_t notify_end_tx)
257 {
258 	struct rxrpc_skb_priv *sp;
259 	struct sk_buff *skb;
260 	struct sock *sk = &rx->sk;
261 	long timeo;
262 	bool more;
263 	int ret, copied;
264 
265 	timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
266 
267 	/* this should be in poll */
268 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
269 
270 	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
271 		return -EPIPE;
272 
273 	more = msg->msg_flags & MSG_MORE;
274 
275 	if (call->tx_total_len != -1) {
276 		if (len > call->tx_total_len)
277 			return -EMSGSIZE;
278 		if (!more && len != call->tx_total_len)
279 			return -EMSGSIZE;
280 	}
281 
282 	skb = call->tx_pending;
283 	call->tx_pending = NULL;
284 	rxrpc_see_skb(skb, rxrpc_skb_tx_seen);
285 
286 	copied = 0;
287 	do {
288 		/* Check to see if there's a ping ACK to reply to. */
289 		if (call->ackr_reason == RXRPC_ACK_PING_RESPONSE)
290 			rxrpc_send_ack_packet(call, false, NULL);
291 
292 		if (!skb) {
293 			size_t size, chunk, max, space;
294 
295 			_debug("alloc");
296 
297 			if (call->tx_top - call->tx_hard_ack >=
298 			    min_t(unsigned int, call->tx_winsize,
299 				  call->cong_cwnd + call->cong_extra)) {
300 				ret = -EAGAIN;
301 				if (msg->msg_flags & MSG_DONTWAIT)
302 					goto maybe_error;
303 				ret = rxrpc_wait_for_tx_window(rx, call,
304 							       &timeo,
305 							       msg->msg_flags & MSG_WAITALL);
306 				if (ret < 0)
307 					goto maybe_error;
308 			}
309 
310 			max = RXRPC_JUMBO_DATALEN;
311 			max -= call->conn->security_size;
312 			max &= ~(call->conn->size_align - 1UL);
313 
314 			chunk = max;
315 			if (chunk > msg_data_left(msg) && !more)
316 				chunk = msg_data_left(msg);
317 
318 			space = chunk + call->conn->size_align;
319 			space &= ~(call->conn->size_align - 1UL);
320 
321 			size = space + call->conn->security_size;
322 
323 			_debug("SIZE: %zu/%zu/%zu", chunk, space, size);
324 
325 			/* create a buffer that we can retain until it's ACK'd */
326 			skb = sock_alloc_send_skb(
327 				sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
328 			if (!skb)
329 				goto maybe_error;
330 
331 			rxrpc_new_skb(skb, rxrpc_skb_tx_new);
332 
333 			_debug("ALLOC SEND %p", skb);
334 
335 			ASSERTCMP(skb->mark, ==, 0);
336 
337 			_debug("HS: %u", call->conn->security_size);
338 			skb_reserve(skb, call->conn->security_size);
339 			skb->len += call->conn->security_size;
340 
341 			sp = rxrpc_skb(skb);
342 			sp->remain = chunk;
343 			if (sp->remain > skb_tailroom(skb))
344 				sp->remain = skb_tailroom(skb);
345 
346 			_net("skb: hr %d, tr %d, hl %d, rm %d",
347 			       skb_headroom(skb),
348 			       skb_tailroom(skb),
349 			       skb_headlen(skb),
350 			       sp->remain);
351 
352 			skb->ip_summed = CHECKSUM_UNNECESSARY;
353 		}
354 
355 		_debug("append");
356 		sp = rxrpc_skb(skb);
357 
358 		/* append next segment of data to the current buffer */
359 		if (msg_data_left(msg) > 0) {
360 			int copy = skb_tailroom(skb);
361 			ASSERTCMP(copy, >, 0);
362 			if (copy > msg_data_left(msg))
363 				copy = msg_data_left(msg);
364 			if (copy > sp->remain)
365 				copy = sp->remain;
366 
367 			_debug("add");
368 			ret = skb_add_data(skb, &msg->msg_iter, copy);
369 			_debug("added");
370 			if (ret < 0)
371 				goto efault;
372 			sp->remain -= copy;
373 			skb->mark += copy;
374 			copied += copy;
375 			if (call->tx_total_len != -1)
376 				call->tx_total_len -= copy;
377 		}
378 
379 		/* add the packet to the send queue if it's now full */
380 		if (sp->remain <= 0 ||
381 		    (msg_data_left(msg) == 0 && !more)) {
382 			struct rxrpc_connection *conn = call->conn;
383 			uint32_t seq;
384 			size_t pad;
385 
386 			/* pad out if we're using security */
387 			if (conn->security_ix) {
388 				pad = conn->security_size + skb->mark;
389 				pad = conn->size_align - pad;
390 				pad &= conn->size_align - 1;
391 				_debug("pad %zu", pad);
392 				if (pad)
393 					skb_put_zero(skb, pad);
394 			}
395 
396 			seq = call->tx_top + 1;
397 
398 			sp->hdr.seq	= seq;
399 			sp->hdr._rsvd	= 0;
400 			sp->hdr.flags	= conn->out_clientflag;
401 
402 			if (msg_data_left(msg) == 0 && !more)
403 				sp->hdr.flags |= RXRPC_LAST_PACKET;
404 			else if (call->tx_top - call->tx_hard_ack <
405 				 call->tx_winsize)
406 				sp->hdr.flags |= RXRPC_MORE_PACKETS;
407 
408 			ret = conn->security->secure_packet(
409 				call, skb, skb->mark, skb->head);
410 			if (ret < 0)
411 				goto out;
412 
413 			rxrpc_queue_packet(rx, call, skb,
414 					   !msg_data_left(msg) && !more,
415 					   notify_end_tx);
416 			skb = NULL;
417 		}
418 
419 		/* Check for the far side aborting the call or a network error
420 		 * occurring.  If this happens, save any packet that was under
421 		 * construction so that in the case of a network error, the
422 		 * call can be retried or redirected.
423 		 */
424 		if (call->state == RXRPC_CALL_COMPLETE) {
425 			ret = call->error;
426 			goto out;
427 		}
428 	} while (msg_data_left(msg) > 0);
429 
430 success:
431 	ret = copied;
432 out:
433 	call->tx_pending = skb;
434 	_leave(" = %d", ret);
435 	return ret;
436 
437 maybe_error:
438 	if (copied)
439 		goto success;
440 	goto out;
441 
442 efault:
443 	ret = -EFAULT;
444 	goto out;
445 }
446 
447 /*
448  * extract control messages from the sendmsg() control buffer
449  */
450 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
451 {
452 	struct cmsghdr *cmsg;
453 	bool got_user_ID = false;
454 	int len;
455 
456 	if (msg->msg_controllen == 0)
457 		return -EINVAL;
458 
459 	for_each_cmsghdr(cmsg, msg) {
460 		if (!CMSG_OK(msg, cmsg))
461 			return -EINVAL;
462 
463 		len = cmsg->cmsg_len - sizeof(struct cmsghdr);
464 		_debug("CMSG %d, %d, %d",
465 		       cmsg->cmsg_level, cmsg->cmsg_type, len);
466 
467 		if (cmsg->cmsg_level != SOL_RXRPC)
468 			continue;
469 
470 		switch (cmsg->cmsg_type) {
471 		case RXRPC_USER_CALL_ID:
472 			if (msg->msg_flags & MSG_CMSG_COMPAT) {
473 				if (len != sizeof(u32))
474 					return -EINVAL;
475 				p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
476 			} else {
477 				if (len != sizeof(unsigned long))
478 					return -EINVAL;
479 				p->call.user_call_ID = *(unsigned long *)
480 					CMSG_DATA(cmsg);
481 			}
482 			got_user_ID = true;
483 			break;
484 
485 		case RXRPC_ABORT:
486 			if (p->command != RXRPC_CMD_SEND_DATA)
487 				return -EINVAL;
488 			p->command = RXRPC_CMD_SEND_ABORT;
489 			if (len != sizeof(p->abort_code))
490 				return -EINVAL;
491 			p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
492 			if (p->abort_code == 0)
493 				return -EINVAL;
494 			break;
495 
496 		case RXRPC_ACCEPT:
497 			if (p->command != RXRPC_CMD_SEND_DATA)
498 				return -EINVAL;
499 			p->command = RXRPC_CMD_ACCEPT;
500 			if (len != 0)
501 				return -EINVAL;
502 			break;
503 
504 		case RXRPC_EXCLUSIVE_CALL:
505 			p->exclusive = true;
506 			if (len != 0)
507 				return -EINVAL;
508 			break;
509 
510 		case RXRPC_UPGRADE_SERVICE:
511 			p->upgrade = true;
512 			if (len != 0)
513 				return -EINVAL;
514 			break;
515 
516 		case RXRPC_TX_LENGTH:
517 			if (p->call.tx_total_len != -1 || len != sizeof(__s64))
518 				return -EINVAL;
519 			p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
520 			if (p->call.tx_total_len < 0)
521 				return -EINVAL;
522 			break;
523 
524 		case RXRPC_SET_CALL_TIMEOUT:
525 			if (len & 3 || len < 4 || len > 12)
526 				return -EINVAL;
527 			memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
528 			p->call.nr_timeouts = len / 4;
529 			if (p->call.timeouts.hard > INT_MAX / HZ)
530 				return -ERANGE;
531 			if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
532 				return -ERANGE;
533 			if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
534 				return -ERANGE;
535 			break;
536 
537 		default:
538 			return -EINVAL;
539 		}
540 	}
541 
542 	if (!got_user_ID)
543 		return -EINVAL;
544 	if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
545 		return -EINVAL;
546 	_leave(" = 0");
547 	return 0;
548 }
549 
550 /*
551  * Create a new client call for sendmsg().
552  * - Called with the socket lock held, which it must release.
553  * - If it returns a call, the call's lock will need releasing by the caller.
554  */
555 static struct rxrpc_call *
556 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
557 				  struct rxrpc_send_params *p)
558 	__releases(&rx->sk.sk_lock.slock)
559 	__acquires(&call->user_mutex)
560 {
561 	struct rxrpc_conn_parameters cp;
562 	struct rxrpc_call *call;
563 	struct key *key;
564 
565 	DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
566 
567 	_enter("");
568 
569 	if (!msg->msg_name) {
570 		release_sock(&rx->sk);
571 		return ERR_PTR(-EDESTADDRREQ);
572 	}
573 
574 	key = rx->key;
575 	if (key && !rx->key->payload.data[0])
576 		key = NULL;
577 
578 	memset(&cp, 0, sizeof(cp));
579 	cp.local		= rx->local;
580 	cp.key			= rx->key;
581 	cp.security_level	= rx->min_sec_level;
582 	cp.exclusive		= rx->exclusive | p->exclusive;
583 	cp.upgrade		= p->upgrade;
584 	cp.service_id		= srx->srx_service;
585 	call = rxrpc_new_client_call(rx, &cp, srx, &p->call, GFP_KERNEL,
586 				     atomic_inc_return(&rxrpc_debug_id));
587 	/* The socket is now unlocked */
588 
589 	rxrpc_put_peer(cp.peer);
590 	_leave(" = %p\n", call);
591 	return call;
592 }
593 
594 /*
595  * send a message forming part of a client call through an RxRPC socket
596  * - caller holds the socket locked
597  * - the socket may be either a client socket or a server socket
598  */
599 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
600 	__releases(&rx->sk.sk_lock.slock)
601 	__releases(&call->user_mutex)
602 {
603 	enum rxrpc_call_state state;
604 	struct rxrpc_call *call;
605 	unsigned long now, j;
606 	int ret;
607 
608 	struct rxrpc_send_params p = {
609 		.call.tx_total_len	= -1,
610 		.call.user_call_ID	= 0,
611 		.call.nr_timeouts	= 0,
612 		.abort_code		= 0,
613 		.command		= RXRPC_CMD_SEND_DATA,
614 		.exclusive		= false,
615 		.upgrade		= false,
616 	};
617 
618 	_enter("");
619 
620 	ret = rxrpc_sendmsg_cmsg(msg, &p);
621 	if (ret < 0)
622 		goto error_release_sock;
623 
624 	if (p.command == RXRPC_CMD_ACCEPT) {
625 		ret = -EINVAL;
626 		if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
627 			goto error_release_sock;
628 		call = rxrpc_accept_call(rx, p.call.user_call_ID, NULL);
629 		/* The socket is now unlocked. */
630 		if (IS_ERR(call))
631 			return PTR_ERR(call);
632 		ret = 0;
633 		goto out_put_unlock;
634 	}
635 
636 	call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
637 	if (!call) {
638 		ret = -EBADSLT;
639 		if (p.command != RXRPC_CMD_SEND_DATA)
640 			goto error_release_sock;
641 		call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
642 		/* The socket is now unlocked... */
643 		if (IS_ERR(call))
644 			return PTR_ERR(call);
645 		/* ... and we have the call lock. */
646 	} else {
647 		switch (READ_ONCE(call->state)) {
648 		case RXRPC_CALL_UNINITIALISED:
649 		case RXRPC_CALL_CLIENT_AWAIT_CONN:
650 		case RXRPC_CALL_SERVER_PREALLOC:
651 		case RXRPC_CALL_SERVER_SECURING:
652 		case RXRPC_CALL_SERVER_ACCEPTING:
653 			ret = -EBUSY;
654 			goto error_release_sock;
655 		default:
656 			break;
657 		}
658 
659 		ret = mutex_lock_interruptible(&call->user_mutex);
660 		release_sock(&rx->sk);
661 		if (ret < 0) {
662 			ret = -ERESTARTSYS;
663 			goto error_put;
664 		}
665 
666 		if (p.call.tx_total_len != -1) {
667 			ret = -EINVAL;
668 			if (call->tx_total_len != -1 ||
669 			    call->tx_pending ||
670 			    call->tx_top != 0)
671 				goto error_put;
672 			call->tx_total_len = p.call.tx_total_len;
673 		}
674 	}
675 
676 	switch (p.call.nr_timeouts) {
677 	case 3:
678 		j = msecs_to_jiffies(p.call.timeouts.normal);
679 		if (p.call.timeouts.normal > 0 && j == 0)
680 			j = 1;
681 		WRITE_ONCE(call->next_rx_timo, j);
682 		/* Fall through */
683 	case 2:
684 		j = msecs_to_jiffies(p.call.timeouts.idle);
685 		if (p.call.timeouts.idle > 0 && j == 0)
686 			j = 1;
687 		WRITE_ONCE(call->next_req_timo, j);
688 		/* Fall through */
689 	case 1:
690 		if (p.call.timeouts.hard > 0) {
691 			j = msecs_to_jiffies(p.call.timeouts.hard);
692 			now = jiffies;
693 			j += now;
694 			WRITE_ONCE(call->expect_term_by, j);
695 			rxrpc_reduce_call_timer(call, j, now,
696 						rxrpc_timer_set_for_hard);
697 		}
698 		break;
699 	}
700 
701 	state = READ_ONCE(call->state);
702 	_debug("CALL %d USR %lx ST %d on CONN %p",
703 	       call->debug_id, call->user_call_ID, state, call->conn);
704 
705 	if (state >= RXRPC_CALL_COMPLETE) {
706 		/* it's too late for this call */
707 		ret = -ESHUTDOWN;
708 	} else if (p.command == RXRPC_CMD_SEND_ABORT) {
709 		ret = 0;
710 		if (rxrpc_abort_call("CMD", call, 0, p.abort_code, -ECONNABORTED))
711 			ret = rxrpc_send_abort_packet(call);
712 	} else if (p.command != RXRPC_CMD_SEND_DATA) {
713 		ret = -EINVAL;
714 	} else if (rxrpc_is_client_call(call) &&
715 		   state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
716 		/* request phase complete for this client call */
717 		ret = -EPROTO;
718 	} else if (rxrpc_is_service_call(call) &&
719 		   state != RXRPC_CALL_SERVER_ACK_REQUEST &&
720 		   state != RXRPC_CALL_SERVER_SEND_REPLY) {
721 		/* Reply phase not begun or not complete for service call. */
722 		ret = -EPROTO;
723 	} else {
724 		ret = rxrpc_send_data(rx, call, msg, len, NULL);
725 	}
726 
727 out_put_unlock:
728 	mutex_unlock(&call->user_mutex);
729 error_put:
730 	rxrpc_put_call(call, rxrpc_call_put);
731 	_leave(" = %d", ret);
732 	return ret;
733 
734 error_release_sock:
735 	release_sock(&rx->sk);
736 	return ret;
737 }
738 
739 /**
740  * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
741  * @sock: The socket the call is on
742  * @call: The call to send data through
743  * @msg: The data to send
744  * @len: The amount of data to send
745  * @notify_end_tx: Notification that the last packet is queued.
746  *
747  * Allow a kernel service to send data on a call.  The call must be in an state
748  * appropriate to sending data.  No control data should be supplied in @msg,
749  * nor should an address be supplied.  MSG_MORE should be flagged if there's
750  * more data to come, otherwise this data will end the transmission phase.
751  */
752 int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
753 			   struct msghdr *msg, size_t len,
754 			   rxrpc_notify_end_tx_t notify_end_tx)
755 {
756 	int ret;
757 
758 	_enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
759 
760 	ASSERTCMP(msg->msg_name, ==, NULL);
761 	ASSERTCMP(msg->msg_control, ==, NULL);
762 
763 	mutex_lock(&call->user_mutex);
764 
765 	_debug("CALL %d USR %lx ST %d on CONN %p",
766 	       call->debug_id, call->user_call_ID, call->state, call->conn);
767 
768 	switch (READ_ONCE(call->state)) {
769 	case RXRPC_CALL_CLIENT_SEND_REQUEST:
770 	case RXRPC_CALL_SERVER_ACK_REQUEST:
771 	case RXRPC_CALL_SERVER_SEND_REPLY:
772 		ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
773 				      notify_end_tx);
774 		break;
775 	case RXRPC_CALL_COMPLETE:
776 		read_lock_bh(&call->state_lock);
777 		ret = call->error;
778 		read_unlock_bh(&call->state_lock);
779 		break;
780 	default:
781 		/* Request phase complete for this client call */
782 		trace_rxrpc_rx_eproto(call, 0, tracepoint_string("late_send"));
783 		ret = -EPROTO;
784 		break;
785 	}
786 
787 	mutex_unlock(&call->user_mutex);
788 	_leave(" = %d", ret);
789 	return ret;
790 }
791 EXPORT_SYMBOL(rxrpc_kernel_send_data);
792 
793 /**
794  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
795  * @sock: The socket the call is on
796  * @call: The call to be aborted
797  * @abort_code: The abort code to stick into the ABORT packet
798  * @error: Local error value
799  * @why: 3-char string indicating why.
800  *
801  * Allow a kernel service to abort a call, if it's still in an abortable state
802  * and return true if the call was aborted, false if it was already complete.
803  */
804 bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
805 			     u32 abort_code, int error, const char *why)
806 {
807 	bool aborted;
808 
809 	_enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
810 
811 	mutex_lock(&call->user_mutex);
812 
813 	aborted = rxrpc_abort_call(why, call, 0, abort_code, error);
814 	if (aborted)
815 		rxrpc_send_abort_packet(call);
816 
817 	mutex_unlock(&call->user_mutex);
818 	return aborted;
819 }
820 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
821 
822 /**
823  * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
824  * @sock: The socket the call is on
825  * @call: The call to be informed
826  * @tx_total_len: The amount of data to be transmitted for this call
827  *
828  * Allow a kernel service to set the total transmit length on a call.  This
829  * allows buffer-to-packet encrypt-and-copy to be performed.
830  *
831  * This function is primarily for use for setting the reply length since the
832  * request length can be set when beginning the call.
833  */
834 void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
835 				s64 tx_total_len)
836 {
837 	WARN_ON(call->tx_total_len != -1);
838 	call->tx_total_len = tx_total_len;
839 }
840 EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);
841