xref: /openbmc/linux/net/rxrpc/sendmsg.c (revision 5d331b7f)
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 		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("");
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 		/* add the packet to the send queue if it's now full */
390 		if (sp->remain <= 0 ||
391 		    (msg_data_left(msg) == 0 && !more)) {
392 			struct rxrpc_connection *conn = call->conn;
393 			uint32_t seq;
394 			size_t pad;
395 
396 			/* pad out if we're using security */
397 			if (conn->security_ix) {
398 				pad = conn->security_size + skb->mark;
399 				pad = conn->size_align - pad;
400 				pad &= conn->size_align - 1;
401 				_debug("pad %zu", pad);
402 				if (pad)
403 					skb_put_zero(skb, pad);
404 			}
405 
406 			seq = call->tx_top + 1;
407 
408 			sp->hdr.seq	= seq;
409 			sp->hdr._rsvd	= 0;
410 			sp->hdr.flags	= conn->out_clientflag;
411 
412 			if (msg_data_left(msg) == 0 && !more)
413 				sp->hdr.flags |= RXRPC_LAST_PACKET;
414 			else if (call->tx_top - call->tx_hard_ack <
415 				 call->tx_winsize)
416 				sp->hdr.flags |= RXRPC_MORE_PACKETS;
417 
418 			ret = conn->security->secure_packet(
419 				call, skb, skb->mark, skb->head);
420 			if (ret < 0)
421 				goto out;
422 
423 			rxrpc_queue_packet(rx, call, skb,
424 					   !msg_data_left(msg) && !more,
425 					   notify_end_tx);
426 			skb = NULL;
427 		}
428 
429 		/* Check for the far side aborting the call or a network error
430 		 * occurring.  If this happens, save any packet that was under
431 		 * construction so that in the case of a network error, the
432 		 * call can be retried or redirected.
433 		 */
434 		if (call->state == RXRPC_CALL_COMPLETE) {
435 			ret = call->error;
436 			goto out;
437 		}
438 	} while (msg_data_left(msg) > 0);
439 
440 success:
441 	ret = copied;
442 out:
443 	call->tx_pending = skb;
444 	_leave(" = %d", ret);
445 	return ret;
446 
447 maybe_error:
448 	if (copied)
449 		goto success;
450 	goto out;
451 
452 efault:
453 	ret = -EFAULT;
454 	goto out;
455 }
456 
457 /*
458  * extract control messages from the sendmsg() control buffer
459  */
460 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
461 {
462 	struct cmsghdr *cmsg;
463 	bool got_user_ID = false;
464 	int len;
465 
466 	if (msg->msg_controllen == 0)
467 		return -EINVAL;
468 
469 	for_each_cmsghdr(cmsg, msg) {
470 		if (!CMSG_OK(msg, cmsg))
471 			return -EINVAL;
472 
473 		len = cmsg->cmsg_len - sizeof(struct cmsghdr);
474 		_debug("CMSG %d, %d, %d",
475 		       cmsg->cmsg_level, cmsg->cmsg_type, len);
476 
477 		if (cmsg->cmsg_level != SOL_RXRPC)
478 			continue;
479 
480 		switch (cmsg->cmsg_type) {
481 		case RXRPC_USER_CALL_ID:
482 			if (msg->msg_flags & MSG_CMSG_COMPAT) {
483 				if (len != sizeof(u32))
484 					return -EINVAL;
485 				p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
486 			} else {
487 				if (len != sizeof(unsigned long))
488 					return -EINVAL;
489 				p->call.user_call_ID = *(unsigned long *)
490 					CMSG_DATA(cmsg);
491 			}
492 			got_user_ID = true;
493 			break;
494 
495 		case RXRPC_ABORT:
496 			if (p->command != RXRPC_CMD_SEND_DATA)
497 				return -EINVAL;
498 			p->command = RXRPC_CMD_SEND_ABORT;
499 			if (len != sizeof(p->abort_code))
500 				return -EINVAL;
501 			p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
502 			if (p->abort_code == 0)
503 				return -EINVAL;
504 			break;
505 
506 		case RXRPC_ACCEPT:
507 			if (p->command != RXRPC_CMD_SEND_DATA)
508 				return -EINVAL;
509 			p->command = RXRPC_CMD_ACCEPT;
510 			if (len != 0)
511 				return -EINVAL;
512 			break;
513 
514 		case RXRPC_EXCLUSIVE_CALL:
515 			p->exclusive = true;
516 			if (len != 0)
517 				return -EINVAL;
518 			break;
519 
520 		case RXRPC_UPGRADE_SERVICE:
521 			p->upgrade = true;
522 			if (len != 0)
523 				return -EINVAL;
524 			break;
525 
526 		case RXRPC_TX_LENGTH:
527 			if (p->call.tx_total_len != -1 || len != sizeof(__s64))
528 				return -EINVAL;
529 			p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
530 			if (p->call.tx_total_len < 0)
531 				return -EINVAL;
532 			break;
533 
534 		case RXRPC_SET_CALL_TIMEOUT:
535 			if (len & 3 || len < 4 || len > 12)
536 				return -EINVAL;
537 			memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
538 			p->call.nr_timeouts = len / 4;
539 			if (p->call.timeouts.hard > INT_MAX / HZ)
540 				return -ERANGE;
541 			if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
542 				return -ERANGE;
543 			if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
544 				return -ERANGE;
545 			break;
546 
547 		default:
548 			return -EINVAL;
549 		}
550 	}
551 
552 	if (!got_user_ID)
553 		return -EINVAL;
554 	if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
555 		return -EINVAL;
556 	_leave(" = 0");
557 	return 0;
558 }
559 
560 /*
561  * Create a new client call for sendmsg().
562  * - Called with the socket lock held, which it must release.
563  * - If it returns a call, the call's lock will need releasing by the caller.
564  */
565 static struct rxrpc_call *
566 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
567 				  struct rxrpc_send_params *p)
568 	__releases(&rx->sk.sk_lock.slock)
569 	__acquires(&call->user_mutex)
570 {
571 	struct rxrpc_conn_parameters cp;
572 	struct rxrpc_call *call;
573 	struct key *key;
574 
575 	DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
576 
577 	_enter("");
578 
579 	if (!msg->msg_name) {
580 		release_sock(&rx->sk);
581 		return ERR_PTR(-EDESTADDRREQ);
582 	}
583 
584 	key = rx->key;
585 	if (key && !rx->key->payload.data[0])
586 		key = NULL;
587 
588 	memset(&cp, 0, sizeof(cp));
589 	cp.local		= rx->local;
590 	cp.key			= rx->key;
591 	cp.security_level	= rx->min_sec_level;
592 	cp.exclusive		= rx->exclusive | p->exclusive;
593 	cp.upgrade		= p->upgrade;
594 	cp.service_id		= srx->srx_service;
595 	call = rxrpc_new_client_call(rx, &cp, srx, &p->call, GFP_KERNEL,
596 				     atomic_inc_return(&rxrpc_debug_id));
597 	/* The socket is now unlocked */
598 
599 	rxrpc_put_peer(cp.peer);
600 	_leave(" = %p\n", call);
601 	return call;
602 }
603 
604 /*
605  * send a message forming part of a client call through an RxRPC socket
606  * - caller holds the socket locked
607  * - the socket may be either a client socket or a server socket
608  */
609 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
610 	__releases(&rx->sk.sk_lock.slock)
611 	__releases(&call->user_mutex)
612 {
613 	enum rxrpc_call_state state;
614 	struct rxrpc_call *call;
615 	unsigned long now, j;
616 	int ret;
617 
618 	struct rxrpc_send_params p = {
619 		.call.tx_total_len	= -1,
620 		.call.user_call_ID	= 0,
621 		.call.nr_timeouts	= 0,
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