xref: /kernel/linux/linux-5.10/net/rxrpc/sendmsg.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0-or-later
2/* AF_RXRPC sendmsg() implementation.
3 *
4 * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7
8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9
10#include <linux/net.h>
11#include <linux/gfp.h>
12#include <linux/skbuff.h>
13#include <linux/export.h>
14#include <linux/sched/signal.h>
15
16#include <net/sock.h>
17#include <net/af_rxrpc.h>
18#include "ar-internal.h"
19
20/*
21 * Return true if there's sufficient Tx queue space.
22 */
23static bool rxrpc_check_tx_space(struct rxrpc_call *call, rxrpc_seq_t *_tx_win)
24{
25	unsigned int win_size =
26		min_t(unsigned int, call->tx_winsize,
27		      call->cong_cwnd + call->cong_extra);
28	rxrpc_seq_t tx_win = READ_ONCE(call->tx_hard_ack);
29
30	if (_tx_win)
31		*_tx_win = tx_win;
32	return call->tx_top - tx_win < win_size;
33}
34
35/*
36 * Wait for space to appear in the Tx queue or a signal to occur.
37 */
38static int rxrpc_wait_for_tx_window_intr(struct rxrpc_sock *rx,
39					 struct rxrpc_call *call,
40					 long *timeo)
41{
42	for (;;) {
43		set_current_state(TASK_INTERRUPTIBLE);
44		if (rxrpc_check_tx_space(call, NULL))
45			return 0;
46
47		if (call->state >= RXRPC_CALL_COMPLETE)
48			return call->error;
49
50		if (signal_pending(current))
51			return sock_intr_errno(*timeo);
52
53		trace_rxrpc_transmit(call, rxrpc_transmit_wait);
54		*timeo = schedule_timeout(*timeo);
55	}
56}
57
58/*
59 * Wait for space to appear in the Tx queue uninterruptibly, but with
60 * a timeout of 2*RTT if no progress was made and a signal occurred.
61 */
62static int rxrpc_wait_for_tx_window_waitall(struct rxrpc_sock *rx,
63					    struct rxrpc_call *call)
64{
65	rxrpc_seq_t tx_start, tx_win;
66	signed long rtt, timeout;
67
68	rtt = READ_ONCE(call->peer->srtt_us) >> 3;
69	rtt = usecs_to_jiffies(rtt) * 2;
70	if (rtt < 2)
71		rtt = 2;
72
73	timeout = rtt;
74	tx_start = READ_ONCE(call->tx_hard_ack);
75
76	for (;;) {
77		set_current_state(TASK_UNINTERRUPTIBLE);
78
79		tx_win = READ_ONCE(call->tx_hard_ack);
80		if (rxrpc_check_tx_space(call, &tx_win))
81			return 0;
82
83		if (call->state >= RXRPC_CALL_COMPLETE)
84			return call->error;
85
86		if (timeout == 0 &&
87		    tx_win == tx_start && signal_pending(current))
88			return -EINTR;
89
90		if (tx_win != tx_start) {
91			timeout = rtt;
92			tx_start = tx_win;
93		}
94
95		trace_rxrpc_transmit(call, rxrpc_transmit_wait);
96		timeout = schedule_timeout(timeout);
97	}
98}
99
100/*
101 * Wait for space to appear in the Tx queue uninterruptibly.
102 */
103static int rxrpc_wait_for_tx_window_nonintr(struct rxrpc_sock *rx,
104					    struct rxrpc_call *call,
105					    long *timeo)
106{
107	for (;;) {
108		set_current_state(TASK_UNINTERRUPTIBLE);
109		if (rxrpc_check_tx_space(call, NULL))
110			return 0;
111
112		if (call->state >= RXRPC_CALL_COMPLETE)
113			return call->error;
114
115		trace_rxrpc_transmit(call, rxrpc_transmit_wait);
116		*timeo = schedule_timeout(*timeo);
117	}
118}
119
120/*
121 * wait for space to appear in the transmit/ACK window
122 * - caller holds the socket locked
123 */
124static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
125				    struct rxrpc_call *call,
126				    long *timeo,
127				    bool waitall)
128{
129	DECLARE_WAITQUEUE(myself, current);
130	int ret;
131
132	_enter(",{%u,%u,%u}",
133	       call->tx_hard_ack, call->tx_top, call->tx_winsize);
134
135	add_wait_queue(&call->waitq, &myself);
136
137	switch (call->interruptibility) {
138	case RXRPC_INTERRUPTIBLE:
139		if (waitall)
140			ret = rxrpc_wait_for_tx_window_waitall(rx, call);
141		else
142			ret = rxrpc_wait_for_tx_window_intr(rx, call, timeo);
143		break;
144	case RXRPC_PREINTERRUPTIBLE:
145	case RXRPC_UNINTERRUPTIBLE:
146	default:
147		ret = rxrpc_wait_for_tx_window_nonintr(rx, call, timeo);
148		break;
149	}
150
151	remove_wait_queue(&call->waitq, &myself);
152	set_current_state(TASK_RUNNING);
153	_leave(" = %d", ret);
154	return ret;
155}
156
157/*
158 * Schedule an instant Tx resend.
159 */
160static inline void rxrpc_instant_resend(struct rxrpc_call *call, int ix)
161{
162	spin_lock_bh(&call->lock);
163
164	if (call->state < RXRPC_CALL_COMPLETE) {
165		call->rxtx_annotations[ix] =
166			(call->rxtx_annotations[ix] & RXRPC_TX_ANNO_LAST) |
167			RXRPC_TX_ANNO_RETRANS;
168		if (!test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
169			rxrpc_queue_call(call);
170	}
171
172	spin_unlock_bh(&call->lock);
173}
174
175/*
176 * Notify the owner of the call that the transmit phase is ended and the last
177 * packet has been queued.
178 */
179static void rxrpc_notify_end_tx(struct rxrpc_sock *rx, struct rxrpc_call *call,
180				rxrpc_notify_end_tx_t notify_end_tx)
181{
182	if (notify_end_tx)
183		notify_end_tx(&rx->sk, call, call->user_call_ID);
184}
185
186/*
187 * Queue a DATA packet for transmission, set the resend timeout and send
188 * the packet immediately.  Returns the error from rxrpc_send_data_packet()
189 * in case the caller wants to do something with it.
190 */
191static int rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
192			      struct sk_buff *skb, bool last,
193			      rxrpc_notify_end_tx_t notify_end_tx)
194{
195	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
196	unsigned long now;
197	rxrpc_seq_t seq = sp->hdr.seq;
198	int ret, ix;
199	u8 annotation = RXRPC_TX_ANNO_UNACK;
200
201	_net("queue skb %p [%d]", skb, seq);
202
203	ASSERTCMP(seq, ==, call->tx_top + 1);
204
205	if (last)
206		annotation |= RXRPC_TX_ANNO_LAST;
207
208	/* We have to set the timestamp before queueing as the retransmit
209	 * algorithm can see the packet as soon as we queue it.
210	 */
211	skb->tstamp = ktime_get_real();
212
213	ix = seq & RXRPC_RXTX_BUFF_MASK;
214	rxrpc_get_skb(skb, rxrpc_skb_got);
215	call->rxtx_annotations[ix] = annotation;
216	smp_wmb();
217	call->rxtx_buffer[ix] = skb;
218	call->tx_top = seq;
219	if (last)
220		trace_rxrpc_transmit(call, rxrpc_transmit_queue_last);
221	else
222		trace_rxrpc_transmit(call, rxrpc_transmit_queue);
223
224	if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {
225		_debug("________awaiting reply/ACK__________");
226		write_lock_bh(&call->state_lock);
227		switch (call->state) {
228		case RXRPC_CALL_CLIENT_SEND_REQUEST:
229			call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
230			rxrpc_notify_end_tx(rx, call, notify_end_tx);
231			break;
232		case RXRPC_CALL_SERVER_ACK_REQUEST:
233			call->state = RXRPC_CALL_SERVER_SEND_REPLY;
234			now = jiffies;
235			WRITE_ONCE(call->ack_at, now + MAX_JIFFY_OFFSET);
236			if (call->ackr_reason == RXRPC_ACK_DELAY)
237				call->ackr_reason = 0;
238			trace_rxrpc_timer(call, rxrpc_timer_init_for_send_reply, now);
239			if (!last)
240				break;
241			fallthrough;
242		case RXRPC_CALL_SERVER_SEND_REPLY:
243			call->state = RXRPC_CALL_SERVER_AWAIT_ACK;
244			rxrpc_notify_end_tx(rx, call, notify_end_tx);
245			break;
246		default:
247			break;
248		}
249		write_unlock_bh(&call->state_lock);
250	}
251
252	if (seq == 1 && rxrpc_is_client_call(call))
253		rxrpc_expose_client_call(call);
254
255	ret = rxrpc_send_data_packet(call, skb, false);
256	if (ret < 0) {
257		switch (ret) {
258		case -ENETUNREACH:
259		case -EHOSTUNREACH:
260		case -ECONNREFUSED:
261			rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
262						  0, ret);
263			goto out;
264		}
265		_debug("need instant resend %d", ret);
266		rxrpc_instant_resend(call, ix);
267	} else {
268		unsigned long now = jiffies;
269		unsigned long resend_at = now + call->peer->rto_j;
270
271		WRITE_ONCE(call->resend_at, resend_at);
272		rxrpc_reduce_call_timer(call, resend_at, now,
273					rxrpc_timer_set_for_send);
274	}
275
276out:
277	rxrpc_free_skb(skb, rxrpc_skb_freed);
278	_leave(" = %d", ret);
279	return ret;
280}
281
282/*
283 * send data through a socket
284 * - must be called in process context
285 * - The caller holds the call user access mutex, but not the socket lock.
286 */
287static int rxrpc_send_data(struct rxrpc_sock *rx,
288			   struct rxrpc_call *call,
289			   struct msghdr *msg, size_t len,
290			   rxrpc_notify_end_tx_t notify_end_tx,
291			   bool *_dropped_lock)
292{
293	struct rxrpc_skb_priv *sp;
294	struct sk_buff *skb;
295	struct sock *sk = &rx->sk;
296	enum rxrpc_call_state state;
297	long timeo;
298	bool more = msg->msg_flags & MSG_MORE;
299	int ret, copied = 0;
300
301	timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
302
303	/* this should be in poll */
304	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
305
306reload:
307	ret = -EPIPE;
308	if (sk->sk_shutdown & SEND_SHUTDOWN)
309		goto maybe_error;
310	state = READ_ONCE(call->state);
311	ret = -ESHUTDOWN;
312	if (state >= RXRPC_CALL_COMPLETE)
313		goto maybe_error;
314	ret = -EPROTO;
315	if (state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
316	    state != RXRPC_CALL_SERVER_ACK_REQUEST &&
317	    state != RXRPC_CALL_SERVER_SEND_REPLY)
318		goto maybe_error;
319
320	ret = -EMSGSIZE;
321	if (call->tx_total_len != -1) {
322		if (len - copied > call->tx_total_len)
323			goto maybe_error;
324		if (!more && len - copied != call->tx_total_len)
325			goto maybe_error;
326	}
327
328	skb = call->tx_pending;
329	call->tx_pending = NULL;
330	rxrpc_see_skb(skb, rxrpc_skb_seen);
331
332	do {
333		/* Check to see if there's a ping ACK to reply to. */
334		if (call->ackr_reason == RXRPC_ACK_PING_RESPONSE)
335			rxrpc_send_ack_packet(call, false, NULL);
336
337		if (!skb) {
338			size_t size, chunk, max, space;
339
340			_debug("alloc");
341
342			if (!rxrpc_check_tx_space(call, NULL))
343				goto wait_for_space;
344
345			max = RXRPC_JUMBO_DATALEN;
346			max -= call->conn->security_size;
347			max &= ~(call->conn->size_align - 1UL);
348
349			chunk = max;
350			if (chunk > msg_data_left(msg) && !more)
351				chunk = msg_data_left(msg);
352
353			space = chunk + call->conn->size_align;
354			space &= ~(call->conn->size_align - 1UL);
355
356			size = space + call->conn->security_size;
357
358			_debug("SIZE: %zu/%zu/%zu", chunk, space, size);
359
360			/* create a buffer that we can retain until it's ACK'd */
361			skb = sock_alloc_send_skb(
362				sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
363			if (!skb)
364				goto maybe_error;
365
366			sp = rxrpc_skb(skb);
367			sp->rx_flags |= RXRPC_SKB_TX_BUFFER;
368			rxrpc_new_skb(skb, rxrpc_skb_new);
369
370			_debug("ALLOC SEND %p", skb);
371
372			ASSERTCMP(skb->mark, ==, 0);
373
374			_debug("HS: %u", call->conn->security_size);
375			skb_reserve(skb, call->conn->security_size);
376			skb->len += call->conn->security_size;
377
378			sp->remain = chunk;
379			if (sp->remain > skb_tailroom(skb))
380				sp->remain = skb_tailroom(skb);
381
382			_net("skb: hr %d, tr %d, hl %d, rm %d",
383			       skb_headroom(skb),
384			       skb_tailroom(skb),
385			       skb_headlen(skb),
386			       sp->remain);
387
388			skb->ip_summed = CHECKSUM_UNNECESSARY;
389		}
390
391		_debug("append");
392		sp = rxrpc_skb(skb);
393
394		/* append next segment of data to the current buffer */
395		if (msg_data_left(msg) > 0) {
396			int copy = skb_tailroom(skb);
397			ASSERTCMP(copy, >, 0);
398			if (copy > msg_data_left(msg))
399				copy = msg_data_left(msg);
400			if (copy > sp->remain)
401				copy = sp->remain;
402
403			_debug("add");
404			ret = skb_add_data(skb, &msg->msg_iter, copy);
405			_debug("added");
406			if (ret < 0)
407				goto efault;
408			sp->remain -= copy;
409			skb->mark += copy;
410			copied += copy;
411			if (call->tx_total_len != -1)
412				call->tx_total_len -= copy;
413		}
414
415		/* check for the far side aborting the call or a network error
416		 * occurring */
417		if (call->state == RXRPC_CALL_COMPLETE)
418			goto call_terminated;
419
420		/* add the packet to the send queue if it's now full */
421		if (sp->remain <= 0 ||
422		    (msg_data_left(msg) == 0 && !more)) {
423			struct rxrpc_connection *conn = call->conn;
424			uint32_t seq;
425			size_t pad;
426
427			/* pad out if we're using security */
428			if (conn->security_ix) {
429				pad = conn->security_size + skb->mark;
430				pad = conn->size_align - pad;
431				pad &= conn->size_align - 1;
432				_debug("pad %zu", pad);
433				if (pad)
434					skb_put_zero(skb, pad);
435			}
436
437			seq = call->tx_top + 1;
438
439			sp->hdr.seq	= seq;
440			sp->hdr._rsvd	= 0;
441			sp->hdr.flags	= conn->out_clientflag;
442
443			if (msg_data_left(msg) == 0 && !more)
444				sp->hdr.flags |= RXRPC_LAST_PACKET;
445			else if (call->tx_top - call->tx_hard_ack <
446				 call->tx_winsize)
447				sp->hdr.flags |= RXRPC_MORE_PACKETS;
448
449			ret = call->security->secure_packet(
450				call, skb, skb->mark, skb->head);
451			if (ret < 0)
452				goto out;
453
454			ret = rxrpc_queue_packet(rx, call, skb,
455						 !msg_data_left(msg) && !more,
456						 notify_end_tx);
457			/* Should check for failure here */
458			skb = NULL;
459		}
460	} while (msg_data_left(msg) > 0);
461
462success:
463	ret = copied;
464	if (READ_ONCE(call->state) == RXRPC_CALL_COMPLETE) {
465		read_lock_bh(&call->state_lock);
466		if (call->error < 0)
467			ret = call->error;
468		read_unlock_bh(&call->state_lock);
469	}
470out:
471	call->tx_pending = skb;
472	_leave(" = %d", ret);
473	return ret;
474
475call_terminated:
476	rxrpc_free_skb(skb, rxrpc_skb_freed);
477	_leave(" = %d", call->error);
478	return call->error;
479
480maybe_error:
481	if (copied)
482		goto success;
483	goto out;
484
485efault:
486	ret = -EFAULT;
487	goto out;
488
489wait_for_space:
490	ret = -EAGAIN;
491	if (msg->msg_flags & MSG_DONTWAIT)
492		goto maybe_error;
493	mutex_unlock(&call->user_mutex);
494	*_dropped_lock = true;
495	ret = rxrpc_wait_for_tx_window(rx, call, &timeo,
496				       msg->msg_flags & MSG_WAITALL);
497	if (ret < 0)
498		goto maybe_error;
499	if (call->interruptibility == RXRPC_INTERRUPTIBLE) {
500		if (mutex_lock_interruptible(&call->user_mutex) < 0) {
501			ret = sock_intr_errno(timeo);
502			goto maybe_error;
503		}
504	} else {
505		mutex_lock(&call->user_mutex);
506	}
507	*_dropped_lock = false;
508	goto reload;
509}
510
511/*
512 * extract control messages from the sendmsg() control buffer
513 */
514static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
515{
516	struct cmsghdr *cmsg;
517	bool got_user_ID = false;
518	int len;
519
520	if (msg->msg_controllen == 0)
521		return -EINVAL;
522
523	for_each_cmsghdr(cmsg, msg) {
524		if (!CMSG_OK(msg, cmsg))
525			return -EINVAL;
526
527		len = cmsg->cmsg_len - sizeof(struct cmsghdr);
528		_debug("CMSG %d, %d, %d",
529		       cmsg->cmsg_level, cmsg->cmsg_type, len);
530
531		if (cmsg->cmsg_level != SOL_RXRPC)
532			continue;
533
534		switch (cmsg->cmsg_type) {
535		case RXRPC_USER_CALL_ID:
536			if (msg->msg_flags & MSG_CMSG_COMPAT) {
537				if (len != sizeof(u32))
538					return -EINVAL;
539				p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
540			} else {
541				if (len != sizeof(unsigned long))
542					return -EINVAL;
543				p->call.user_call_ID = *(unsigned long *)
544					CMSG_DATA(cmsg);
545			}
546			got_user_ID = true;
547			break;
548
549		case RXRPC_ABORT:
550			if (p->command != RXRPC_CMD_SEND_DATA)
551				return -EINVAL;
552			p->command = RXRPC_CMD_SEND_ABORT;
553			if (len != sizeof(p->abort_code))
554				return -EINVAL;
555			p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
556			if (p->abort_code == 0)
557				return -EINVAL;
558			break;
559
560		case RXRPC_CHARGE_ACCEPT:
561			if (p->command != RXRPC_CMD_SEND_DATA)
562				return -EINVAL;
563			p->command = RXRPC_CMD_CHARGE_ACCEPT;
564			if (len != 0)
565				return -EINVAL;
566			break;
567
568		case RXRPC_EXCLUSIVE_CALL:
569			p->exclusive = true;
570			if (len != 0)
571				return -EINVAL;
572			break;
573
574		case RXRPC_UPGRADE_SERVICE:
575			p->upgrade = true;
576			if (len != 0)
577				return -EINVAL;
578			break;
579
580		case RXRPC_TX_LENGTH:
581			if (p->call.tx_total_len != -1 || len != sizeof(__s64))
582				return -EINVAL;
583			p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
584			if (p->call.tx_total_len < 0)
585				return -EINVAL;
586			break;
587
588		case RXRPC_SET_CALL_TIMEOUT:
589			if (len & 3 || len < 4 || len > 12)
590				return -EINVAL;
591			memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
592			p->call.nr_timeouts = len / 4;
593			if (p->call.timeouts.hard > INT_MAX / HZ)
594				return -ERANGE;
595			if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
596				return -ERANGE;
597			if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
598				return -ERANGE;
599			break;
600
601		default:
602			return -EINVAL;
603		}
604	}
605
606	if (!got_user_ID)
607		return -EINVAL;
608	if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
609		return -EINVAL;
610	_leave(" = 0");
611	return 0;
612}
613
614/*
615 * Create a new client call for sendmsg().
616 * - Called with the socket lock held, which it must release.
617 * - If it returns a call, the call's lock will need releasing by the caller.
618 */
619static struct rxrpc_call *
620rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
621				  struct rxrpc_send_params *p)
622	__releases(&rx->sk.sk_lock.slock)
623	__acquires(&call->user_mutex)
624{
625	struct rxrpc_conn_parameters cp;
626	struct rxrpc_call *call;
627	struct key *key;
628
629	DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
630
631	_enter("");
632
633	if (!msg->msg_name) {
634		release_sock(&rx->sk);
635		return ERR_PTR(-EDESTADDRREQ);
636	}
637
638	key = rx->key;
639	if (key && !rx->key->payload.data[0])
640		key = NULL;
641
642	memset(&cp, 0, sizeof(cp));
643	cp.local		= rx->local;
644	cp.key			= rx->key;
645	cp.security_level	= rx->min_sec_level;
646	cp.exclusive		= rx->exclusive | p->exclusive;
647	cp.upgrade		= p->upgrade;
648	cp.service_id		= srx->srx_service;
649	call = rxrpc_new_client_call(rx, &cp, srx, &p->call, GFP_KERNEL,
650				     atomic_inc_return(&rxrpc_debug_id));
651	/* The socket is now unlocked */
652
653	rxrpc_put_peer(cp.peer);
654	_leave(" = %p\n", call);
655	return call;
656}
657
658/*
659 * send a message forming part of a client call through an RxRPC socket
660 * - caller holds the socket locked
661 * - the socket may be either a client socket or a server socket
662 */
663int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
664	__releases(&rx->sk.sk_lock.slock)
665	__releases(&call->user_mutex)
666{
667	enum rxrpc_call_state state;
668	struct rxrpc_call *call;
669	unsigned long now, j;
670	bool dropped_lock = false;
671	int ret;
672
673	struct rxrpc_send_params p = {
674		.call.tx_total_len	= -1,
675		.call.user_call_ID	= 0,
676		.call.nr_timeouts	= 0,
677		.call.interruptibility	= RXRPC_INTERRUPTIBLE,
678		.abort_code		= 0,
679		.command		= RXRPC_CMD_SEND_DATA,
680		.exclusive		= false,
681		.upgrade		= false,
682	};
683
684	_enter("");
685
686	ret = rxrpc_sendmsg_cmsg(msg, &p);
687	if (ret < 0)
688		goto error_release_sock;
689
690	if (p.command == RXRPC_CMD_CHARGE_ACCEPT) {
691		ret = -EINVAL;
692		if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
693			goto error_release_sock;
694		ret = rxrpc_user_charge_accept(rx, p.call.user_call_ID);
695		goto error_release_sock;
696	}
697
698	call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
699	if (!call) {
700		ret = -EBADSLT;
701		if (p.command != RXRPC_CMD_SEND_DATA)
702			goto error_release_sock;
703		call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
704		/* The socket is now unlocked... */
705		if (IS_ERR(call))
706			return PTR_ERR(call);
707		/* ... and we have the call lock. */
708		ret = 0;
709		if (READ_ONCE(call->state) == RXRPC_CALL_COMPLETE)
710			goto out_put_unlock;
711	} else {
712		switch (READ_ONCE(call->state)) {
713		case RXRPC_CALL_UNINITIALISED:
714		case RXRPC_CALL_CLIENT_AWAIT_CONN:
715		case RXRPC_CALL_SERVER_PREALLOC:
716		case RXRPC_CALL_SERVER_SECURING:
717			rxrpc_put_call(call, rxrpc_call_put);
718			ret = -EBUSY;
719			goto error_release_sock;
720		default:
721			break;
722		}
723
724		ret = mutex_lock_interruptible(&call->user_mutex);
725		release_sock(&rx->sk);
726		if (ret < 0) {
727			ret = -ERESTARTSYS;
728			goto error_put;
729		}
730
731		if (p.call.tx_total_len != -1) {
732			ret = -EINVAL;
733			if (call->tx_total_len != -1 ||
734			    call->tx_pending ||
735			    call->tx_top != 0)
736				goto out_put_unlock;
737			call->tx_total_len = p.call.tx_total_len;
738		}
739	}
740
741	switch (p.call.nr_timeouts) {
742	case 3:
743		j = msecs_to_jiffies(p.call.timeouts.normal);
744		if (p.call.timeouts.normal > 0 && j == 0)
745			j = 1;
746		WRITE_ONCE(call->next_rx_timo, j);
747		fallthrough;
748	case 2:
749		j = msecs_to_jiffies(p.call.timeouts.idle);
750		if (p.call.timeouts.idle > 0 && j == 0)
751			j = 1;
752		WRITE_ONCE(call->next_req_timo, j);
753		fallthrough;
754	case 1:
755		if (p.call.timeouts.hard > 0) {
756			j = p.call.timeouts.hard * HZ;
757			now = jiffies;
758			j += now;
759			WRITE_ONCE(call->expect_term_by, j);
760			rxrpc_reduce_call_timer(call, j, now,
761						rxrpc_timer_set_for_hard);
762		}
763		break;
764	}
765
766	state = READ_ONCE(call->state);
767	_debug("CALL %d USR %lx ST %d on CONN %p",
768	       call->debug_id, call->user_call_ID, state, call->conn);
769
770	if (state >= RXRPC_CALL_COMPLETE) {
771		/* it's too late for this call */
772		ret = -ESHUTDOWN;
773	} else if (p.command == RXRPC_CMD_SEND_ABORT) {
774		ret = 0;
775		if (rxrpc_abort_call("CMD", call, 0, p.abort_code, -ECONNABORTED))
776			ret = rxrpc_send_abort_packet(call);
777	} else if (p.command != RXRPC_CMD_SEND_DATA) {
778		ret = -EINVAL;
779	} else {
780		ret = rxrpc_send_data(rx, call, msg, len, NULL, &dropped_lock);
781	}
782
783out_put_unlock:
784	if (!dropped_lock)
785		mutex_unlock(&call->user_mutex);
786error_put:
787	rxrpc_put_call(call, rxrpc_call_put);
788	_leave(" = %d", ret);
789	return ret;
790
791error_release_sock:
792	release_sock(&rx->sk);
793	return ret;
794}
795
796/**
797 * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
798 * @sock: The socket the call is on
799 * @call: The call to send data through
800 * @msg: The data to send
801 * @len: The amount of data to send
802 * @notify_end_tx: Notification that the last packet is queued.
803 *
804 * Allow a kernel service to send data on a call.  The call must be in an state
805 * appropriate to sending data.  No control data should be supplied in @msg,
806 * nor should an address be supplied.  MSG_MORE should be flagged if there's
807 * more data to come, otherwise this data will end the transmission phase.
808 */
809int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
810			   struct msghdr *msg, size_t len,
811			   rxrpc_notify_end_tx_t notify_end_tx)
812{
813	bool dropped_lock = false;
814	int ret;
815
816	_enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
817
818	ASSERTCMP(msg->msg_name, ==, NULL);
819	ASSERTCMP(msg->msg_control, ==, NULL);
820
821	mutex_lock(&call->user_mutex);
822
823	_debug("CALL %d USR %lx ST %d on CONN %p",
824	       call->debug_id, call->user_call_ID, call->state, call->conn);
825
826	switch (READ_ONCE(call->state)) {
827	case RXRPC_CALL_CLIENT_SEND_REQUEST:
828	case RXRPC_CALL_SERVER_ACK_REQUEST:
829	case RXRPC_CALL_SERVER_SEND_REPLY:
830		ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
831				      notify_end_tx, &dropped_lock);
832		break;
833	case RXRPC_CALL_COMPLETE:
834		read_lock_bh(&call->state_lock);
835		ret = call->error;
836		read_unlock_bh(&call->state_lock);
837		break;
838	default:
839		/* Request phase complete for this client call */
840		trace_rxrpc_rx_eproto(call, 0, tracepoint_string("late_send"));
841		ret = -EPROTO;
842		break;
843	}
844
845	if (!dropped_lock)
846		mutex_unlock(&call->user_mutex);
847	_leave(" = %d", ret);
848	return ret;
849}
850EXPORT_SYMBOL(rxrpc_kernel_send_data);
851
852/**
853 * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
854 * @sock: The socket the call is on
855 * @call: The call to be aborted
856 * @abort_code: The abort code to stick into the ABORT packet
857 * @error: Local error value
858 * @why: 3-char string indicating why.
859 *
860 * Allow a kernel service to abort a call, if it's still in an abortable state
861 * and return true if the call was aborted, false if it was already complete.
862 */
863bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
864			     u32 abort_code, int error, const char *why)
865{
866	bool aborted;
867
868	_enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
869
870	mutex_lock(&call->user_mutex);
871
872	aborted = rxrpc_abort_call(why, call, 0, abort_code, error);
873	if (aborted)
874		rxrpc_send_abort_packet(call);
875
876	mutex_unlock(&call->user_mutex);
877	return aborted;
878}
879EXPORT_SYMBOL(rxrpc_kernel_abort_call);
880
881/**
882 * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
883 * @sock: The socket the call is on
884 * @call: The call to be informed
885 * @tx_total_len: The amount of data to be transmitted for this call
886 *
887 * Allow a kernel service to set the total transmit length on a call.  This
888 * allows buffer-to-packet encrypt-and-copy to be performed.
889 *
890 * This function is primarily for use for setting the reply length since the
891 * request length can be set when beginning the call.
892 */
893void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
894				s64 tx_total_len)
895{
896	WARN_ON(call->tx_total_len != -1);
897	call->tx_total_len = tx_total_len;
898}
899EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);
900