xref: /linux/net/rxrpc/sendmsg.c (revision ec8c17e5ecb4a5a74069687ccb6d2cfe1851302e)
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  * Propose an abort to be made in the I/O thread.
22  */
rxrpc_propose_abort(struct rxrpc_call * call,s32 abort_code,int error,enum rxrpc_abort_reason why)23 bool rxrpc_propose_abort(struct rxrpc_call *call, s32 abort_code, int error,
24 			 enum rxrpc_abort_reason why)
25 {
26 	_enter("{%d},%d,%d,%u", call->debug_id, abort_code, error, why);
27 
28 	if (!call->send_abort && !rxrpc_call_is_complete(call)) {
29 		call->send_abort_why = why;
30 		call->send_abort_err = error;
31 		call->send_abort_seq = 0;
32 		trace_rxrpc_abort_call(call, abort_code);
33 		/* Request abort locklessly vs rxrpc_input_call_event(). */
34 		smp_store_release(&call->send_abort, abort_code);
35 		rxrpc_poke_call(call, rxrpc_call_poke_abort);
36 		return true;
37 	}
38 
39 	return false;
40 }
41 
42 /*
43  * Wait for a call to become connected.  Interruption here doesn't cause the
44  * call to be aborted.
45  */
rxrpc_wait_to_be_connected(struct rxrpc_call * call,long * timeo)46 static int rxrpc_wait_to_be_connected(struct rxrpc_call *call, long *timeo)
47 {
48 	DECLARE_WAITQUEUE(myself, current);
49 	int ret = 0;
50 
51 	_enter("%d", call->debug_id);
52 
53 	if (rxrpc_call_state(call) != RXRPC_CALL_CLIENT_AWAIT_CONN)
54 		goto no_wait;
55 
56 	add_wait_queue_exclusive(&call->waitq, &myself);
57 
58 	for (;;) {
59 		switch (call->interruptibility) {
60 		case RXRPC_INTERRUPTIBLE:
61 		case RXRPC_PREINTERRUPTIBLE:
62 			set_current_state(TASK_INTERRUPTIBLE);
63 			break;
64 		case RXRPC_UNINTERRUPTIBLE:
65 		default:
66 			set_current_state(TASK_UNINTERRUPTIBLE);
67 			break;
68 		}
69 
70 		if (rxrpc_call_state(call) != RXRPC_CALL_CLIENT_AWAIT_CONN)
71 			break;
72 		if ((call->interruptibility == RXRPC_INTERRUPTIBLE ||
73 		     call->interruptibility == RXRPC_PREINTERRUPTIBLE) &&
74 		    signal_pending(current)) {
75 			ret = sock_intr_errno(*timeo);
76 			break;
77 		}
78 		*timeo = schedule_timeout(*timeo);
79 	}
80 
81 	remove_wait_queue(&call->waitq, &myself);
82 	__set_current_state(TASK_RUNNING);
83 
84 no_wait:
85 	if (ret == 0 && rxrpc_call_is_complete(call))
86 		ret = call->error;
87 
88 	_leave(" = %d", ret);
89 	return ret;
90 }
91 
92 /*
93  * Return true if there's sufficient Tx queue space.
94  */
rxrpc_check_tx_space(struct rxrpc_call * call,rxrpc_seq_t * _tx_win)95 static bool rxrpc_check_tx_space(struct rxrpc_call *call, rxrpc_seq_t *_tx_win)
96 {
97 	if (_tx_win)
98 		*_tx_win = call->tx_bottom;
99 	return call->tx_prepared - call->tx_bottom < 256;
100 }
101 
102 /*
103  * Wait for space to appear in the Tx queue or a signal to occur.
104  */
rxrpc_wait_for_tx_window_intr(struct rxrpc_sock * rx,struct rxrpc_call * call,long * timeo)105 static int rxrpc_wait_for_tx_window_intr(struct rxrpc_sock *rx,
106 					 struct rxrpc_call *call,
107 					 long *timeo)
108 {
109 	for (;;) {
110 		set_current_state(TASK_INTERRUPTIBLE);
111 		if (rxrpc_check_tx_space(call, NULL))
112 			return 0;
113 
114 		if (rxrpc_call_is_complete(call))
115 			return call->error;
116 
117 		if (signal_pending(current))
118 			return sock_intr_errno(*timeo);
119 
120 		trace_rxrpc_txqueue(call, rxrpc_txqueue_wait);
121 		*timeo = schedule_timeout(*timeo);
122 	}
123 }
124 
125 /*
126  * Wait for space to appear in the Tx queue uninterruptibly, but with
127  * a timeout of 2*RTT if no progress was made and a signal occurred.
128  */
rxrpc_wait_for_tx_window_waitall(struct rxrpc_sock * rx,struct rxrpc_call * call)129 static int rxrpc_wait_for_tx_window_waitall(struct rxrpc_sock *rx,
130 					    struct rxrpc_call *call)
131 {
132 	rxrpc_seq_t tx_start, tx_win;
133 	signed long rtt, timeout;
134 
135 	rtt = READ_ONCE(call->peer->srtt_us) >> 3;
136 	rtt = usecs_to_jiffies(rtt) * 2;
137 	if (rtt < 2)
138 		rtt = 2;
139 
140 	timeout = rtt;
141 	tx_start = smp_load_acquire(&call->acks_hard_ack);
142 
143 	for (;;) {
144 		set_current_state(TASK_UNINTERRUPTIBLE);
145 
146 		if (rxrpc_check_tx_space(call, &tx_win))
147 			return 0;
148 
149 		if (rxrpc_call_is_complete(call))
150 			return call->error;
151 
152 		if (timeout == 0 &&
153 		    tx_win == tx_start && signal_pending(current))
154 			return -EINTR;
155 
156 		if (tx_win != tx_start) {
157 			timeout = rtt;
158 			tx_start = tx_win;
159 		}
160 
161 		trace_rxrpc_txqueue(call, rxrpc_txqueue_wait);
162 		timeout = schedule_timeout(timeout);
163 	}
164 }
165 
166 /*
167  * Wait for space to appear in the Tx queue uninterruptibly.
168  */
rxrpc_wait_for_tx_window_nonintr(struct rxrpc_sock * rx,struct rxrpc_call * call,long * timeo)169 static int rxrpc_wait_for_tx_window_nonintr(struct rxrpc_sock *rx,
170 					    struct rxrpc_call *call,
171 					    long *timeo)
172 {
173 	for (;;) {
174 		set_current_state(TASK_UNINTERRUPTIBLE);
175 		if (rxrpc_check_tx_space(call, NULL))
176 			return 0;
177 
178 		if (rxrpc_call_is_complete(call))
179 			return call->error;
180 
181 		trace_rxrpc_txqueue(call, rxrpc_txqueue_wait);
182 		*timeo = schedule_timeout(*timeo);
183 	}
184 }
185 
186 /*
187  * wait for space to appear in the transmit/ACK window
188  * - caller holds the socket locked
189  */
rxrpc_wait_for_tx_window(struct rxrpc_sock * rx,struct rxrpc_call * call,long * timeo,bool waitall)190 static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
191 				    struct rxrpc_call *call,
192 				    long *timeo,
193 				    bool waitall)
194 {
195 	DECLARE_WAITQUEUE(myself, current);
196 	int ret;
197 
198 	_enter(",{%u,%u,%u,%u}",
199 	       call->tx_bottom, call->acks_hard_ack, call->tx_top, call->tx_winsize);
200 
201 	add_wait_queue(&call->waitq, &myself);
202 
203 	switch (call->interruptibility) {
204 	case RXRPC_INTERRUPTIBLE:
205 		if (waitall)
206 			ret = rxrpc_wait_for_tx_window_waitall(rx, call);
207 		else
208 			ret = rxrpc_wait_for_tx_window_intr(rx, call, timeo);
209 		break;
210 	case RXRPC_PREINTERRUPTIBLE:
211 	case RXRPC_UNINTERRUPTIBLE:
212 	default:
213 		ret = rxrpc_wait_for_tx_window_nonintr(rx, call, timeo);
214 		break;
215 	}
216 
217 	remove_wait_queue(&call->waitq, &myself);
218 	set_current_state(TASK_RUNNING);
219 	_leave(" = %d", ret);
220 	return ret;
221 }
222 
223 /*
224  * Notify the owner of the call that the transmit phase is ended and the last
225  * packet has been queued.
226  */
rxrpc_notify_end_tx(struct rxrpc_sock * rx,struct rxrpc_call * call,rxrpc_notify_end_tx_t notify_end_tx)227 static void rxrpc_notify_end_tx(struct rxrpc_sock *rx, struct rxrpc_call *call,
228 				rxrpc_notify_end_tx_t notify_end_tx)
229 {
230 	if (notify_end_tx)
231 		notify_end_tx(&rx->sk, call, call->user_call_ID);
232 }
233 
234 /*
235  * Queue a DATA packet for transmission, set the resend timeout and send
236  * the packet immediately.  Returns the error from rxrpc_send_data_packet()
237  * in case the caller wants to do something with it.
238  */
rxrpc_queue_packet(struct rxrpc_sock * rx,struct rxrpc_call * call,struct rxrpc_txbuf * txb,rxrpc_notify_end_tx_t notify_end_tx)239 static void rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
240 			       struct rxrpc_txbuf *txb,
241 			       rxrpc_notify_end_tx_t notify_end_tx)
242 {
243 	rxrpc_seq_t seq = txb->seq;
244 	bool poke, last = txb->flags & RXRPC_LAST_PACKET;
245 
246 	rxrpc_inc_stat(call->rxnet, stat_tx_data);
247 
248 	ASSERTCMP(txb->seq, ==, call->tx_prepared + 1);
249 
250 	/* We have to set the timestamp before queueing as the retransmit
251 	 * algorithm can see the packet as soon as we queue it.
252 	 */
253 	txb->last_sent = ktime_get_real();
254 
255 	if (last)
256 		trace_rxrpc_txqueue(call, rxrpc_txqueue_queue_last);
257 	else
258 		trace_rxrpc_txqueue(call, rxrpc_txqueue_queue);
259 
260 	/* Add the packet to the call's output buffer */
261 	spin_lock(&call->tx_lock);
262 	poke = list_empty(&call->tx_sendmsg);
263 	list_add_tail(&txb->call_link, &call->tx_sendmsg);
264 	call->tx_prepared = seq;
265 	if (last)
266 		rxrpc_notify_end_tx(rx, call, notify_end_tx);
267 	spin_unlock(&call->tx_lock);
268 
269 	if (poke)
270 		rxrpc_poke_call(call, rxrpc_call_poke_start);
271 }
272 
273 /*
274  * send data through a socket
275  * - must be called in process context
276  * - The caller holds the call user access mutex, but not the socket lock.
277  */
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,bool * _dropped_lock)278 static int rxrpc_send_data(struct rxrpc_sock *rx,
279 			   struct rxrpc_call *call,
280 			   struct msghdr *msg, size_t len,
281 			   rxrpc_notify_end_tx_t notify_end_tx,
282 			   bool *_dropped_lock)
283 {
284 	struct rxrpc_txbuf *txb;
285 	struct sock *sk = &rx->sk;
286 	enum rxrpc_call_state state;
287 	long timeo;
288 	bool more = msg->msg_flags & MSG_MORE;
289 	int ret, copied = 0;
290 
291 	timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
292 
293 	ret = rxrpc_wait_to_be_connected(call, &timeo);
294 	if (ret < 0)
295 		return ret;
296 
297 	if (call->conn->state == RXRPC_CONN_CLIENT_UNSECURED) {
298 		ret = rxrpc_init_client_conn_security(call->conn);
299 		if (ret < 0)
300 			return ret;
301 	}
302 
303 	/* this should be in poll */
304 	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
305 
306 reload:
307 	txb = call->tx_pending;
308 	call->tx_pending = NULL;
309 	if (txb)
310 		rxrpc_see_txbuf(txb, rxrpc_txbuf_see_send_more);
311 
312 	ret = -EPIPE;
313 	if (sk->sk_shutdown & SEND_SHUTDOWN)
314 		goto maybe_error;
315 	state = rxrpc_call_state(call);
316 	ret = -ESHUTDOWN;
317 	if (state >= RXRPC_CALL_COMPLETE)
318 		goto maybe_error;
319 	ret = -EPROTO;
320 	if (state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
321 	    state != RXRPC_CALL_SERVER_ACK_REQUEST &&
322 	    state != RXRPC_CALL_SERVER_SEND_REPLY) {
323 		/* Request phase complete for this client call */
324 		trace_rxrpc_abort(call->debug_id, rxrpc_sendmsg_late_send,
325 				  call->cid, call->call_id, call->rx_consumed,
326 				  0, -EPROTO);
327 		goto maybe_error;
328 	}
329 
330 	ret = -EMSGSIZE;
331 	if (call->tx_total_len != -1) {
332 		if (len - copied > call->tx_total_len)
333 			goto maybe_error;
334 		if (!more && len - copied != call->tx_total_len)
335 			goto maybe_error;
336 	}
337 
338 	do {
339 		if (!txb) {
340 			size_t remain;
341 
342 			_debug("alloc");
343 
344 			if (!rxrpc_check_tx_space(call, NULL))
345 				goto wait_for_space;
346 
347 			/* Work out the maximum size of a packet.  Assume that
348 			 * the security header is going to be in the padded
349 			 * region (enc blocksize), but the trailer is not.
350 			 */
351 			remain = more ? INT_MAX : msg_data_left(msg);
352 			txb = call->conn->security->alloc_txbuf(call, remain, sk->sk_allocation);
353 			if (!txb) {
354 				ret = -ENOMEM;
355 				goto maybe_error;
356 			}
357 		}
358 
359 		_debug("append");
360 
361 		/* append next segment of data to the current buffer */
362 		if (msg_data_left(msg) > 0) {
363 			size_t copy = min_t(size_t, txb->space, msg_data_left(msg));
364 
365 			_debug("add %zu", copy);
366 			if (!copy_from_iter_full(txb->kvec[0].iov_base + txb->offset,
367 						 copy, &msg->msg_iter))
368 				goto efault;
369 			_debug("added");
370 			txb->space -= copy;
371 			txb->len += copy;
372 			txb->offset += copy;
373 			copied += copy;
374 			if (call->tx_total_len != -1)
375 				call->tx_total_len -= copy;
376 		}
377 
378 		/* check for the far side aborting the call or a network error
379 		 * occurring */
380 		if (rxrpc_call_is_complete(call))
381 			goto call_terminated;
382 
383 		/* add the packet to the send queue if it's now full */
384 		if (!txb->space ||
385 		    (msg_data_left(msg) == 0 && !more)) {
386 			if (msg_data_left(msg) == 0 && !more)
387 				txb->flags |= RXRPC_LAST_PACKET;
388 			else if (call->tx_top - call->acks_hard_ack <
389 				 call->tx_winsize)
390 				txb->flags |= RXRPC_MORE_PACKETS;
391 
392 			ret = call->security->secure_packet(call, txb);
393 			if (ret < 0)
394 				goto out;
395 
396 			txb->kvec[0].iov_len += txb->len;
397 			txb->len = txb->kvec[0].iov_len;
398 			rxrpc_queue_packet(rx, call, txb, notify_end_tx);
399 			txb = NULL;
400 		}
401 	} while (msg_data_left(msg) > 0);
402 
403 success:
404 	ret = copied;
405 	if (rxrpc_call_is_complete(call) &&
406 	    call->error < 0)
407 		ret = call->error;
408 out:
409 	call->tx_pending = txb;
410 	_leave(" = %d", ret);
411 	return ret;
412 
413 call_terminated:
414 	rxrpc_put_txbuf(txb, rxrpc_txbuf_put_send_aborted);
415 	_leave(" = %d", call->error);
416 	return call->error;
417 
418 maybe_error:
419 	if (copied)
420 		goto success;
421 	goto out;
422 
423 efault:
424 	ret = -EFAULT;
425 	goto out;
426 
427 wait_for_space:
428 	ret = -EAGAIN;
429 	if (msg->msg_flags & MSG_DONTWAIT)
430 		goto maybe_error;
431 	mutex_unlock(&call->user_mutex);
432 	*_dropped_lock = true;
433 	ret = rxrpc_wait_for_tx_window(rx, call, &timeo,
434 				       msg->msg_flags & MSG_WAITALL);
435 	if (ret < 0)
436 		goto maybe_error;
437 	if (call->interruptibility == RXRPC_INTERRUPTIBLE) {
438 		if (mutex_lock_interruptible(&call->user_mutex) < 0) {
439 			ret = sock_intr_errno(timeo);
440 			goto maybe_error;
441 		}
442 	} else {
443 		mutex_lock(&call->user_mutex);
444 	}
445 	*_dropped_lock = false;
446 	goto reload;
447 }
448 
449 /*
450  * extract control messages from the sendmsg() control buffer
451  */
rxrpc_sendmsg_cmsg(struct msghdr * msg,struct rxrpc_send_params * p)452 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
453 {
454 	struct cmsghdr *cmsg;
455 	bool got_user_ID = false;
456 	int len;
457 
458 	if (msg->msg_controllen == 0)
459 		return -EINVAL;
460 
461 	for_each_cmsghdr(cmsg, msg) {
462 		if (!CMSG_OK(msg, cmsg))
463 			return -EINVAL;
464 
465 		len = cmsg->cmsg_len - sizeof(struct cmsghdr);
466 		_debug("CMSG %d, %d, %d",
467 		       cmsg->cmsg_level, cmsg->cmsg_type, len);
468 
469 		if (cmsg->cmsg_level != SOL_RXRPC)
470 			continue;
471 
472 		switch (cmsg->cmsg_type) {
473 		case RXRPC_USER_CALL_ID:
474 			if (msg->msg_flags & MSG_CMSG_COMPAT) {
475 				if (len != sizeof(u32))
476 					return -EINVAL;
477 				p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
478 			} else {
479 				if (len != sizeof(unsigned long))
480 					return -EINVAL;
481 				p->call.user_call_ID = *(unsigned long *)
482 					CMSG_DATA(cmsg);
483 			}
484 			got_user_ID = true;
485 			break;
486 
487 		case RXRPC_ABORT:
488 			if (p->command != RXRPC_CMD_SEND_DATA)
489 				return -EINVAL;
490 			p->command = RXRPC_CMD_SEND_ABORT;
491 			if (len != sizeof(p->abort_code))
492 				return -EINVAL;
493 			p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
494 			if (p->abort_code == 0)
495 				return -EINVAL;
496 			break;
497 
498 		case RXRPC_CHARGE_ACCEPT:
499 			if (p->command != RXRPC_CMD_SEND_DATA)
500 				return -EINVAL;
501 			p->command = RXRPC_CMD_CHARGE_ACCEPT;
502 			if (len != 0)
503 				return -EINVAL;
504 			break;
505 
506 		case RXRPC_EXCLUSIVE_CALL:
507 			p->exclusive = true;
508 			if (len != 0)
509 				return -EINVAL;
510 			break;
511 
512 		case RXRPC_UPGRADE_SERVICE:
513 			p->upgrade = true;
514 			if (len != 0)
515 				return -EINVAL;
516 			break;
517 
518 		case RXRPC_TX_LENGTH:
519 			if (p->call.tx_total_len != -1 || len != sizeof(__s64))
520 				return -EINVAL;
521 			p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
522 			if (p->call.tx_total_len < 0)
523 				return -EINVAL;
524 			break;
525 
526 		case RXRPC_SET_CALL_TIMEOUT:
527 			if (len & 3 || len < 4 || len > 12)
528 				return -EINVAL;
529 			memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
530 			p->call.nr_timeouts = len / 4;
531 			if (p->call.timeouts.hard > INT_MAX / HZ)
532 				return -ERANGE;
533 			if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
534 				return -ERANGE;
535 			if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
536 				return -ERANGE;
537 			break;
538 
539 		default:
540 			return -EINVAL;
541 		}
542 	}
543 
544 	if (!got_user_ID)
545 		return -EINVAL;
546 	if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
547 		return -EINVAL;
548 	_leave(" = 0");
549 	return 0;
550 }
551 
552 /*
553  * Create a new client call for sendmsg().
554  * - Called with the socket lock held, which it must release.
555  * - If it returns a call, the call's lock will need releasing by the caller.
556  */
557 static struct rxrpc_call *
rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock * rx,struct msghdr * msg,struct rxrpc_send_params * p)558 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
559 				  struct rxrpc_send_params *p)
560 	__releases(&rx->sk.sk_lock.slock)
561 	__acquires(&call->user_mutex)
562 {
563 	struct rxrpc_conn_parameters cp;
564 	struct rxrpc_peer *peer;
565 	struct rxrpc_call *call;
566 	struct key *key;
567 
568 	DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
569 
570 	_enter("");
571 
572 	if (!msg->msg_name) {
573 		release_sock(&rx->sk);
574 		return ERR_PTR(-EDESTADDRREQ);
575 	}
576 
577 	peer = rxrpc_lookup_peer(rx->local, srx, GFP_KERNEL);
578 	if (!peer) {
579 		release_sock(&rx->sk);
580 		return ERR_PTR(-ENOMEM);
581 	}
582 
583 	key = rx->key;
584 	if (key && !rx->key->payload.data[0])
585 		key = NULL;
586 
587 	memset(&cp, 0, sizeof(cp));
588 	cp.local		= rx->local;
589 	cp.peer			= peer;
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, &p->call, GFP_KERNEL,
596 				     atomic_inc_return(&rxrpc_debug_id));
597 	/* The socket is now unlocked */
598 
599 	rxrpc_put_peer(peer, rxrpc_peer_put_application);
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  */
rxrpc_do_sendmsg(struct rxrpc_sock * rx,struct msghdr * msg,size_t len)609 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
610 	__releases(&rx->sk.sk_lock.slock)
611 {
612 	struct rxrpc_call *call;
613 	bool dropped_lock = false;
614 	int ret;
615 
616 	struct rxrpc_send_params p = {
617 		.call.tx_total_len	= -1,
618 		.call.user_call_ID	= 0,
619 		.call.nr_timeouts	= 0,
620 		.call.interruptibility	= RXRPC_INTERRUPTIBLE,
621 		.abort_code		= 0,
622 		.command		= RXRPC_CMD_SEND_DATA,
623 		.exclusive		= false,
624 		.upgrade		= false,
625 	};
626 
627 	_enter("");
628 
629 	ret = rxrpc_sendmsg_cmsg(msg, &p);
630 	if (ret < 0)
631 		goto error_release_sock;
632 
633 	if (p.command == RXRPC_CMD_CHARGE_ACCEPT) {
634 		ret = -EINVAL;
635 		if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
636 			goto error_release_sock;
637 		ret = rxrpc_user_charge_accept(rx, p.call.user_call_ID);
638 		goto error_release_sock;
639 	}
640 
641 	call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
642 	if (!call) {
643 		ret = -EBADSLT;
644 		if (p.command != RXRPC_CMD_SEND_DATA)
645 			goto error_release_sock;
646 		call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
647 		/* The socket is now unlocked... */
648 		if (IS_ERR(call))
649 			return PTR_ERR(call);
650 		/* ... and we have the call lock. */
651 		p.call.nr_timeouts = 0;
652 		ret = 0;
653 		if (rxrpc_call_is_complete(call))
654 			goto out_put_unlock;
655 	} else {
656 		switch (rxrpc_call_state(call)) {
657 		case RXRPC_CALL_CLIENT_AWAIT_CONN:
658 		case RXRPC_CALL_SERVER_SECURING:
659 			if (p.command == RXRPC_CMD_SEND_ABORT)
660 				break;
661 			fallthrough;
662 		case RXRPC_CALL_UNINITIALISED:
663 		case RXRPC_CALL_SERVER_PREALLOC:
664 			rxrpc_put_call(call, rxrpc_call_put_sendmsg);
665 			ret = -EBUSY;
666 			goto error_release_sock;
667 		default:
668 			break;
669 		}
670 
671 		ret = mutex_lock_interruptible(&call->user_mutex);
672 		release_sock(&rx->sk);
673 		if (ret < 0) {
674 			ret = -ERESTARTSYS;
675 			goto error_put;
676 		}
677 
678 		if (p.call.tx_total_len != -1) {
679 			ret = -EINVAL;
680 			if (call->tx_total_len != -1 ||
681 			    call->tx_pending ||
682 			    call->tx_top != 0)
683 				goto out_put_unlock;
684 			call->tx_total_len = p.call.tx_total_len;
685 		}
686 	}
687 
688 	switch (p.call.nr_timeouts) {
689 	case 3:
690 		WRITE_ONCE(call->next_rx_timo, p.call.timeouts.normal);
691 		fallthrough;
692 	case 2:
693 		WRITE_ONCE(call->next_req_timo, p.call.timeouts.idle);
694 		fallthrough;
695 	case 1:
696 		if (p.call.timeouts.hard > 0) {
697 			ktime_t delay = ms_to_ktime(p.call.timeouts.hard * MSEC_PER_SEC);
698 
699 			WRITE_ONCE(call->expect_term_by,
700 				   ktime_add(p.call.timeouts.hard,
701 					     ktime_get_real()));
702 			trace_rxrpc_timer_set(call, delay, rxrpc_timer_trace_hard);
703 			rxrpc_poke_call(call, rxrpc_call_poke_set_timeout);
704 
705 		}
706 		break;
707 	}
708 
709 	if (rxrpc_call_is_complete(call)) {
710 		/* it's too late for this call */
711 		ret = -ESHUTDOWN;
712 	} else if (p.command == RXRPC_CMD_SEND_ABORT) {
713 		rxrpc_propose_abort(call, p.abort_code, -ECONNABORTED,
714 				    rxrpc_abort_call_sendmsg);
715 		ret = 0;
716 	} else if (p.command != RXRPC_CMD_SEND_DATA) {
717 		ret = -EINVAL;
718 	} else {
719 		ret = rxrpc_send_data(rx, call, msg, len, NULL, &dropped_lock);
720 	}
721 
722 out_put_unlock:
723 	if (!dropped_lock)
724 		mutex_unlock(&call->user_mutex);
725 error_put:
726 	rxrpc_put_call(call, rxrpc_call_put_sendmsg);
727 	_leave(" = %d", ret);
728 	return ret;
729 
730 error_release_sock:
731 	release_sock(&rx->sk);
732 	return ret;
733 }
734 
735 /**
736  * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
737  * @sock: The socket the call is on
738  * @call: The call to send data through
739  * @msg: The data to send
740  * @len: The amount of data to send
741  * @notify_end_tx: Notification that the last packet is queued.
742  *
743  * Allow a kernel service to send data on a call.  The call must be in an state
744  * appropriate to sending data.  No control data should be supplied in @msg,
745  * nor should an address be supplied.  MSG_MORE should be flagged if there's
746  * more data to come, otherwise this data will end the transmission phase.
747  */
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)748 int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
749 			   struct msghdr *msg, size_t len,
750 			   rxrpc_notify_end_tx_t notify_end_tx)
751 {
752 	bool dropped_lock = false;
753 	int ret;
754 
755 	_enter("{%d},", call->debug_id);
756 
757 	ASSERTCMP(msg->msg_name, ==, NULL);
758 	ASSERTCMP(msg->msg_control, ==, NULL);
759 
760 	mutex_lock(&call->user_mutex);
761 
762 	ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
763 			      notify_end_tx, &dropped_lock);
764 	if (ret == -ESHUTDOWN)
765 		ret = call->error;
766 
767 	if (!dropped_lock)
768 		mutex_unlock(&call->user_mutex);
769 	_leave(" = %d", ret);
770 	return ret;
771 }
772 EXPORT_SYMBOL(rxrpc_kernel_send_data);
773 
774 /**
775  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
776  * @sock: The socket the call is on
777  * @call: The call to be aborted
778  * @abort_code: The abort code to stick into the ABORT packet
779  * @error: Local error value
780  * @why: Indication as to why.
781  *
782  * Allow a kernel service to abort a call, if it's still in an abortable state
783  * and return true if the call was aborted, false if it was already complete.
784  */
rxrpc_kernel_abort_call(struct socket * sock,struct rxrpc_call * call,u32 abort_code,int error,enum rxrpc_abort_reason why)785 bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
786 			     u32 abort_code, int error, enum rxrpc_abort_reason why)
787 {
788 	bool aborted;
789 
790 	_enter("{%d},%d,%d,%u", call->debug_id, abort_code, error, why);
791 
792 	mutex_lock(&call->user_mutex);
793 	aborted = rxrpc_propose_abort(call, abort_code, error, why);
794 	mutex_unlock(&call->user_mutex);
795 	return aborted;
796 }
797 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
798 
799 /**
800  * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
801  * @sock: The socket the call is on
802  * @call: The call to be informed
803  * @tx_total_len: The amount of data to be transmitted for this call
804  *
805  * Allow a kernel service to set the total transmit length on a call.  This
806  * allows buffer-to-packet encrypt-and-copy to be performed.
807  *
808  * This function is primarily for use for setting the reply length since the
809  * request length can be set when beginning the call.
810  */
rxrpc_kernel_set_tx_length(struct socket * sock,struct rxrpc_call * call,s64 tx_total_len)811 void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
812 				s64 tx_total_len)
813 {
814 	WARN_ON(call->tx_total_len != -1);
815 	call->tx_total_len = tx_total_len;
816 }
817 EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);
818