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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  */
rxrpc_wait_for_tx_window_intr(struct rxrpc_sock * rx,struct rxrpc_call * call,long * timeo)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  */
rxrpc_wait_for_tx_window_nonintr(struct rxrpc_sock * rx,struct rxrpc_call * call)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 < 2)
66 		rtt2 = 2;
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  */
rxrpc_wait_for_tx_window(struct rxrpc_sock * rx,struct rxrpc_call * call,long * timeo,bool waitall)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  */
rxrpc_instant_resend(struct rxrpc_call * call,int ix)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  */
rxrpc_notify_end_tx(struct rxrpc_sock * rx,struct rxrpc_call * call,rxrpc_notify_end_tx_t notify_end_tx)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  */
rxrpc_queue_packet(struct rxrpc_sock * rx,struct rxrpc_call * call,struct sk_buff * skb,bool last,rxrpc_notify_end_tx_t notify_end_tx)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 			rxrpc_notify_socket(call);
234 			goto out;
235 		}
236 		_debug("need instant resend %d", ret);
237 		rxrpc_instant_resend(call, ix);
238 	} else {
239 		unsigned long now = jiffies, resend_at;
240 
241 		if (call->peer->rtt_usage > 1)
242 			resend_at = nsecs_to_jiffies(call->peer->rtt * 3 / 2);
243 		else
244 			resend_at = rxrpc_resend_timeout;
245 		if (resend_at < 1)
246 			resend_at = 1;
247 
248 		resend_at += now;
249 		WRITE_ONCE(call->resend_at, resend_at);
250 		rxrpc_reduce_call_timer(call, resend_at, now,
251 					rxrpc_timer_set_for_send);
252 	}
253 
254 out:
255 	rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
256 	_leave("");
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  */
rxrpc_send_data(struct rxrpc_sock * rx,struct rxrpc_call * call,struct msghdr * msg,size_t len,rxrpc_notify_end_tx_t notify_end_tx)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_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 		/* add the packet to the send queue if it's now full */
391 		if (sp->remain <= 0 ||
392 		    (msg_data_left(msg) == 0 && !more)) {
393 			struct rxrpc_connection *conn = call->conn;
394 			uint32_t seq;
395 			size_t pad;
396 
397 			/* pad out if we're using security */
398 			if (conn->security_ix) {
399 				pad = conn->security_size + skb->mark;
400 				pad = conn->size_align - pad;
401 				pad &= conn->size_align - 1;
402 				_debug("pad %zu", pad);
403 				if (pad)
404 					skb_put_zero(skb, pad);
405 			}
406 
407 			seq = call->tx_top + 1;
408 
409 			sp->hdr.seq	= seq;
410 			sp->hdr._rsvd	= 0;
411 			sp->hdr.flags	= conn->out_clientflag;
412 
413 			if (msg_data_left(msg) == 0 && !more)
414 				sp->hdr.flags |= RXRPC_LAST_PACKET;
415 			else if (call->tx_top - call->tx_hard_ack <
416 				 call->tx_winsize)
417 				sp->hdr.flags |= RXRPC_MORE_PACKETS;
418 
419 			ret = conn->security->secure_packet(
420 				call, skb, skb->mark, skb->head);
421 			if (ret < 0)
422 				goto out;
423 
424 			rxrpc_queue_packet(rx, call, skb,
425 					   !msg_data_left(msg) && !more,
426 					   notify_end_tx);
427 			skb = NULL;
428 		}
429 
430 		/* Check for the far side aborting the call or a network error
431 		 * occurring.  If this happens, save any packet that was under
432 		 * construction so that in the case of a network error, the
433 		 * call can be retried or redirected.
434 		 */
435 		if (call->state == RXRPC_CALL_COMPLETE) {
436 			ret = call->error;
437 			goto out;
438 		}
439 	} while (msg_data_left(msg) > 0);
440 
441 success:
442 	ret = copied;
443 out:
444 	call->tx_pending = skb;
445 	_leave(" = %d", ret);
446 	return ret;
447 
448 maybe_error:
449 	if (copied)
450 		goto success;
451 	goto out;
452 
453 efault:
454 	ret = -EFAULT;
455 	goto out;
456 }
457 
458 /*
459  * extract control messages from the sendmsg() control buffer
460  */
rxrpc_sendmsg_cmsg(struct msghdr * msg,struct rxrpc_send_params * p)461 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
462 {
463 	struct cmsghdr *cmsg;
464 	bool got_user_ID = false;
465 	int len;
466 
467 	if (msg->msg_controllen == 0)
468 		return -EINVAL;
469 
470 	for_each_cmsghdr(cmsg, msg) {
471 		if (!CMSG_OK(msg, cmsg))
472 			return -EINVAL;
473 
474 		len = cmsg->cmsg_len - sizeof(struct cmsghdr);
475 		_debug("CMSG %d, %d, %d",
476 		       cmsg->cmsg_level, cmsg->cmsg_type, len);
477 
478 		if (cmsg->cmsg_level != SOL_RXRPC)
479 			continue;
480 
481 		switch (cmsg->cmsg_type) {
482 		case RXRPC_USER_CALL_ID:
483 			if (msg->msg_flags & MSG_CMSG_COMPAT) {
484 				if (len != sizeof(u32))
485 					return -EINVAL;
486 				p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
487 			} else {
488 				if (len != sizeof(unsigned long))
489 					return -EINVAL;
490 				p->call.user_call_ID = *(unsigned long *)
491 					CMSG_DATA(cmsg);
492 			}
493 			got_user_ID = true;
494 			break;
495 
496 		case RXRPC_ABORT:
497 			if (p->command != RXRPC_CMD_SEND_DATA)
498 				return -EINVAL;
499 			p->command = RXRPC_CMD_SEND_ABORT;
500 			if (len != sizeof(p->abort_code))
501 				return -EINVAL;
502 			p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
503 			if (p->abort_code == 0)
504 				return -EINVAL;
505 			break;
506 
507 		case RXRPC_ACCEPT:
508 			if (p->command != RXRPC_CMD_SEND_DATA)
509 				return -EINVAL;
510 			p->command = RXRPC_CMD_ACCEPT;
511 			if (len != 0)
512 				return -EINVAL;
513 			break;
514 
515 		case RXRPC_EXCLUSIVE_CALL:
516 			p->exclusive = true;
517 			if (len != 0)
518 				return -EINVAL;
519 			break;
520 
521 		case RXRPC_UPGRADE_SERVICE:
522 			p->upgrade = true;
523 			if (len != 0)
524 				return -EINVAL;
525 			break;
526 
527 		case RXRPC_TX_LENGTH:
528 			if (p->call.tx_total_len != -1 || len != sizeof(__s64))
529 				return -EINVAL;
530 			p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
531 			if (p->call.tx_total_len < 0)
532 				return -EINVAL;
533 			break;
534 
535 		case RXRPC_SET_CALL_TIMEOUT:
536 			if (len & 3 || len < 4 || len > 12)
537 				return -EINVAL;
538 			memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
539 			p->call.nr_timeouts = len / 4;
540 			if (p->call.timeouts.hard > INT_MAX / HZ)
541 				return -ERANGE;
542 			if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
543 				return -ERANGE;
544 			if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
545 				return -ERANGE;
546 			break;
547 
548 		default:
549 			return -EINVAL;
550 		}
551 	}
552 
553 	if (!got_user_ID)
554 		return -EINVAL;
555 	if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
556 		return -EINVAL;
557 	_leave(" = 0");
558 	return 0;
559 }
560 
561 /*
562  * Create a new client call for sendmsg().
563  * - Called with the socket lock held, which it must release.
564  * - If it returns a call, the call's lock will need releasing by the caller.
565  */
566 static struct rxrpc_call *
rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock * rx,struct msghdr * msg,struct rxrpc_send_params * p)567 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
568 				  struct rxrpc_send_params *p)
569 	__releases(&rx->sk.sk_lock.slock)
570 	__acquires(&call->user_mutex)
571 {
572 	struct rxrpc_conn_parameters cp;
573 	struct rxrpc_call *call;
574 	struct key *key;
575 
576 	DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
577 
578 	_enter("");
579 
580 	if (!msg->msg_name) {
581 		release_sock(&rx->sk);
582 		return ERR_PTR(-EDESTADDRREQ);
583 	}
584 
585 	key = rx->key;
586 	if (key && !rx->key->payload.data[0])
587 		key = NULL;
588 
589 	memset(&cp, 0, sizeof(cp));
590 	cp.local		= rx->local;
591 	cp.key			= rx->key;
592 	cp.security_level	= rx->min_sec_level;
593 	cp.exclusive		= rx->exclusive | p->exclusive;
594 	cp.upgrade		= p->upgrade;
595 	cp.service_id		= srx->srx_service;
596 	call = rxrpc_new_client_call(rx, &cp, srx, &p->call, GFP_KERNEL,
597 				     atomic_inc_return(&rxrpc_debug_id));
598 	/* The socket is now unlocked */
599 
600 	rxrpc_put_peer(cp.peer);
601 	_leave(" = %p\n", call);
602 	return call;
603 }
604 
605 /*
606  * send a message forming part of a client call through an RxRPC socket
607  * - caller holds the socket locked
608  * - the socket may be either a client socket or a server socket
609  */
rxrpc_do_sendmsg(struct rxrpc_sock * rx,struct msghdr * msg,size_t len)610 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
611 	__releases(&rx->sk.sk_lock.slock)
612 	__releases(&call->user_mutex)
613 {
614 	enum rxrpc_call_state state;
615 	struct rxrpc_call *call;
616 	unsigned long now, j;
617 	int ret;
618 
619 	struct rxrpc_send_params p = {
620 		.call.tx_total_len	= -1,
621 		.call.user_call_ID	= 0,
622 		.call.nr_timeouts	= 0,
623 		.abort_code		= 0,
624 		.command		= RXRPC_CMD_SEND_DATA,
625 		.exclusive		= false,
626 		.upgrade		= false,
627 	};
628 
629 	_enter("");
630 
631 	ret = rxrpc_sendmsg_cmsg(msg, &p);
632 	if (ret < 0)
633 		goto error_release_sock;
634 
635 	if (p.command == RXRPC_CMD_ACCEPT) {
636 		ret = -EINVAL;
637 		if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
638 			goto error_release_sock;
639 		call = rxrpc_accept_call(rx, p.call.user_call_ID, NULL);
640 		/* The socket is now unlocked. */
641 		if (IS_ERR(call))
642 			return PTR_ERR(call);
643 		ret = 0;
644 		goto out_put_unlock;
645 	}
646 
647 	call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
648 	if (!call) {
649 		ret = -EBADSLT;
650 		if (p.command != RXRPC_CMD_SEND_DATA)
651 			goto error_release_sock;
652 		call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
653 		/* The socket is now unlocked... */
654 		if (IS_ERR(call))
655 			return PTR_ERR(call);
656 		/* ... and we have the call lock. */
657 		ret = 0;
658 		if (READ_ONCE(call->state) == RXRPC_CALL_COMPLETE)
659 			goto out_put_unlock;
660 	} else {
661 		switch (READ_ONCE(call->state)) {
662 		case RXRPC_CALL_UNINITIALISED:
663 		case RXRPC_CALL_CLIENT_AWAIT_CONN:
664 		case RXRPC_CALL_SERVER_PREALLOC:
665 		case RXRPC_CALL_SERVER_SECURING:
666 		case RXRPC_CALL_SERVER_ACCEPTING:
667 			rxrpc_put_call(call, rxrpc_call_put);
668 			ret = -EBUSY;
669 			goto error_release_sock;
670 		default:
671 			break;
672 		}
673 
674 		ret = mutex_lock_interruptible(&call->user_mutex);
675 		release_sock(&rx->sk);
676 		if (ret < 0) {
677 			ret = -ERESTARTSYS;
678 			goto error_put;
679 		}
680 
681 		if (p.call.tx_total_len != -1) {
682 			ret = -EINVAL;
683 			if (call->tx_total_len != -1 ||
684 			    call->tx_pending ||
685 			    call->tx_top != 0)
686 				goto error_put;
687 			call->tx_total_len = p.call.tx_total_len;
688 		}
689 	}
690 
691 	switch (p.call.nr_timeouts) {
692 	case 3:
693 		j = msecs_to_jiffies(p.call.timeouts.normal);
694 		if (p.call.timeouts.normal > 0 && j == 0)
695 			j = 1;
696 		WRITE_ONCE(call->next_rx_timo, j);
697 		/* Fall through */
698 	case 2:
699 		j = msecs_to_jiffies(p.call.timeouts.idle);
700 		if (p.call.timeouts.idle > 0 && j == 0)
701 			j = 1;
702 		WRITE_ONCE(call->next_req_timo, j);
703 		/* Fall through */
704 	case 1:
705 		if (p.call.timeouts.hard > 0) {
706 			j = msecs_to_jiffies(p.call.timeouts.hard);
707 			now = jiffies;
708 			j += now;
709 			WRITE_ONCE(call->expect_term_by, j);
710 			rxrpc_reduce_call_timer(call, j, now,
711 						rxrpc_timer_set_for_hard);
712 		}
713 		break;
714 	}
715 
716 	state = READ_ONCE(call->state);
717 	_debug("CALL %d USR %lx ST %d on CONN %p",
718 	       call->debug_id, call->user_call_ID, state, call->conn);
719 
720 	if (state >= RXRPC_CALL_COMPLETE) {
721 		/* it's too late for this call */
722 		ret = -ESHUTDOWN;
723 	} else if (p.command == RXRPC_CMD_SEND_ABORT) {
724 		ret = 0;
725 		if (rxrpc_abort_call("CMD", call, 0, p.abort_code, -ECONNABORTED))
726 			ret = rxrpc_send_abort_packet(call);
727 	} else if (p.command != RXRPC_CMD_SEND_DATA) {
728 		ret = -EINVAL;
729 	} else if (rxrpc_is_client_call(call) &&
730 		   state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
731 		/* request phase complete for this client call */
732 		ret = -EPROTO;
733 	} else if (rxrpc_is_service_call(call) &&
734 		   state != RXRPC_CALL_SERVER_ACK_REQUEST &&
735 		   state != RXRPC_CALL_SERVER_SEND_REPLY) {
736 		/* Reply phase not begun or not complete for service call. */
737 		ret = -EPROTO;
738 	} else {
739 		ret = rxrpc_send_data(rx, call, msg, len, NULL);
740 	}
741 
742 out_put_unlock:
743 	mutex_unlock(&call->user_mutex);
744 error_put:
745 	rxrpc_put_call(call, rxrpc_call_put);
746 	_leave(" = %d", ret);
747 	return ret;
748 
749 error_release_sock:
750 	release_sock(&rx->sk);
751 	return ret;
752 }
753 
754 /**
755  * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
756  * @sock: The socket the call is on
757  * @call: The call to send data through
758  * @msg: The data to send
759  * @len: The amount of data to send
760  * @notify_end_tx: Notification that the last packet is queued.
761  *
762  * Allow a kernel service to send data on a call.  The call must be in an state
763  * appropriate to sending data.  No control data should be supplied in @msg,
764  * nor should an address be supplied.  MSG_MORE should be flagged if there's
765  * more data to come, otherwise this data will end the transmission phase.
766  */
rxrpc_kernel_send_data(struct socket * sock,struct rxrpc_call * call,struct msghdr * msg,size_t len,rxrpc_notify_end_tx_t notify_end_tx)767 int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
768 			   struct msghdr *msg, size_t len,
769 			   rxrpc_notify_end_tx_t notify_end_tx)
770 {
771 	int ret;
772 
773 	_enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
774 
775 	ASSERTCMP(msg->msg_name, ==, NULL);
776 	ASSERTCMP(msg->msg_control, ==, NULL);
777 
778 	mutex_lock(&call->user_mutex);
779 
780 	_debug("CALL %d USR %lx ST %d on CONN %p",
781 	       call->debug_id, call->user_call_ID, call->state, call->conn);
782 
783 	switch (READ_ONCE(call->state)) {
784 	case RXRPC_CALL_CLIENT_SEND_REQUEST:
785 	case RXRPC_CALL_SERVER_ACK_REQUEST:
786 	case RXRPC_CALL_SERVER_SEND_REPLY:
787 		ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
788 				      notify_end_tx);
789 		break;
790 	case RXRPC_CALL_COMPLETE:
791 		read_lock_bh(&call->state_lock);
792 		ret = call->error;
793 		read_unlock_bh(&call->state_lock);
794 		break;
795 	default:
796 		/* Request phase complete for this client call */
797 		trace_rxrpc_rx_eproto(call, 0, tracepoint_string("late_send"));
798 		ret = -EPROTO;
799 		break;
800 	}
801 
802 	mutex_unlock(&call->user_mutex);
803 	_leave(" = %d", ret);
804 	return ret;
805 }
806 EXPORT_SYMBOL(rxrpc_kernel_send_data);
807 
808 /**
809  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
810  * @sock: The socket the call is on
811  * @call: The call to be aborted
812  * @abort_code: The abort code to stick into the ABORT packet
813  * @error: Local error value
814  * @why: 3-char string indicating why.
815  *
816  * Allow a kernel service to abort a call, if it's still in an abortable state
817  * and return true if the call was aborted, false if it was already complete.
818  */
rxrpc_kernel_abort_call(struct socket * sock,struct rxrpc_call * call,u32 abort_code,int error,const char * why)819 bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
820 			     u32 abort_code, int error, const char *why)
821 {
822 	bool aborted;
823 
824 	_enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
825 
826 	mutex_lock(&call->user_mutex);
827 
828 	aborted = rxrpc_abort_call(why, call, 0, abort_code, error);
829 	if (aborted)
830 		rxrpc_send_abort_packet(call);
831 
832 	mutex_unlock(&call->user_mutex);
833 	return aborted;
834 }
835 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
836 
837 /**
838  * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
839  * @sock: The socket the call is on
840  * @call: The call to be informed
841  * @tx_total_len: The amount of data to be transmitted for this call
842  *
843  * Allow a kernel service to set the total transmit length on a call.  This
844  * allows buffer-to-packet encrypt-and-copy to be performed.
845  *
846  * This function is primarily for use for setting the reply length since the
847  * request length can be set when beginning the call.
848  */
rxrpc_kernel_set_tx_length(struct socket * sock,struct rxrpc_call * call,s64 tx_total_len)849 void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
850 				s64 tx_total_len)
851 {
852 	WARN_ON(call->tx_total_len != -1);
853 	call->tx_total_len = tx_total_len;
854 }
855 EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);
856