rxrpc: Remove call->state_lock
[platform/kernel/linux-rpi.git] / net / rxrpc / sendmsg.c
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  */
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                 /* Request abort locklessly vs rxrpc_input_call_event(). */
33                 smp_store_release(&call->send_abort, abort_code);
34                 rxrpc_poke_call(call, rxrpc_call_poke_abort);
35                 return true;
36         }
37
38         return false;
39 }
40
41 /*
42  * Return true if there's sufficient Tx queue space.
43  */
44 static bool rxrpc_check_tx_space(struct rxrpc_call *call, rxrpc_seq_t *_tx_win)
45 {
46         if (_tx_win)
47                 *_tx_win = call->tx_bottom;
48         return call->tx_prepared - call->tx_bottom < 256;
49 }
50
51 /*
52  * Wait for space to appear in the Tx queue or a signal to occur.
53  */
54 static int rxrpc_wait_for_tx_window_intr(struct rxrpc_sock *rx,
55                                          struct rxrpc_call *call,
56                                          long *timeo)
57 {
58         for (;;) {
59                 set_current_state(TASK_INTERRUPTIBLE);
60                 if (rxrpc_check_tx_space(call, NULL))
61                         return 0;
62
63                 if (rxrpc_call_is_complete(call))
64                         return call->error;
65
66                 if (signal_pending(current))
67                         return sock_intr_errno(*timeo);
68
69                 trace_rxrpc_txqueue(call, rxrpc_txqueue_wait);
70                 *timeo = schedule_timeout(*timeo);
71         }
72 }
73
74 /*
75  * Wait for space to appear in the Tx queue uninterruptibly, but with
76  * a timeout of 2*RTT if no progress was made and a signal occurred.
77  */
78 static int rxrpc_wait_for_tx_window_waitall(struct rxrpc_sock *rx,
79                                             struct rxrpc_call *call)
80 {
81         rxrpc_seq_t tx_start, tx_win;
82         signed long rtt, timeout;
83
84         rtt = READ_ONCE(call->peer->srtt_us) >> 3;
85         rtt = usecs_to_jiffies(rtt) * 2;
86         if (rtt < 2)
87                 rtt = 2;
88
89         timeout = rtt;
90         tx_start = smp_load_acquire(&call->acks_hard_ack);
91
92         for (;;) {
93                 set_current_state(TASK_UNINTERRUPTIBLE);
94
95                 if (rxrpc_check_tx_space(call, &tx_win))
96                         return 0;
97
98                 if (rxrpc_call_is_complete(call))
99                         return call->error;
100
101                 if (timeout == 0 &&
102                     tx_win == tx_start && signal_pending(current))
103                         return -EINTR;
104
105                 if (tx_win != tx_start) {
106                         timeout = rtt;
107                         tx_start = tx_win;
108                 }
109
110                 trace_rxrpc_txqueue(call, rxrpc_txqueue_wait);
111                 timeout = schedule_timeout(timeout);
112         }
113 }
114
115 /*
116  * Wait for space to appear in the Tx queue uninterruptibly.
117  */
118 static int rxrpc_wait_for_tx_window_nonintr(struct rxrpc_sock *rx,
119                                             struct rxrpc_call *call,
120                                             long *timeo)
121 {
122         for (;;) {
123                 set_current_state(TASK_UNINTERRUPTIBLE);
124                 if (rxrpc_check_tx_space(call, NULL))
125                         return 0;
126
127                 if (rxrpc_call_is_complete(call))
128                         return call->error;
129
130                 trace_rxrpc_txqueue(call, rxrpc_txqueue_wait);
131                 *timeo = schedule_timeout(*timeo);
132         }
133 }
134
135 /*
136  * wait for space to appear in the transmit/ACK window
137  * - caller holds the socket locked
138  */
139 static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
140                                     struct rxrpc_call *call,
141                                     long *timeo,
142                                     bool waitall)
143 {
144         DECLARE_WAITQUEUE(myself, current);
145         int ret;
146
147         _enter(",{%u,%u,%u,%u}",
148                call->tx_bottom, call->acks_hard_ack, call->tx_top, call->tx_winsize);
149
150         add_wait_queue(&call->waitq, &myself);
151
152         switch (call->interruptibility) {
153         case RXRPC_INTERRUPTIBLE:
154                 if (waitall)
155                         ret = rxrpc_wait_for_tx_window_waitall(rx, call);
156                 else
157                         ret = rxrpc_wait_for_tx_window_intr(rx, call, timeo);
158                 break;
159         case RXRPC_PREINTERRUPTIBLE:
160         case RXRPC_UNINTERRUPTIBLE:
161         default:
162                 ret = rxrpc_wait_for_tx_window_nonintr(rx, call, timeo);
163                 break;
164         }
165
166         remove_wait_queue(&call->waitq, &myself);
167         set_current_state(TASK_RUNNING);
168         _leave(" = %d", ret);
169         return ret;
170 }
171
172 /*
173  * Notify the owner of the call that the transmit phase is ended and the last
174  * packet has been queued.
175  */
176 static void rxrpc_notify_end_tx(struct rxrpc_sock *rx, struct rxrpc_call *call,
177                                 rxrpc_notify_end_tx_t notify_end_tx)
178 {
179         if (notify_end_tx)
180                 notify_end_tx(&rx->sk, call, call->user_call_ID);
181 }
182
183 /*
184  * Queue a DATA packet for transmission, set the resend timeout and send
185  * the packet immediately.  Returns the error from rxrpc_send_data_packet()
186  * in case the caller wants to do something with it.
187  */
188 static void rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
189                                struct rxrpc_txbuf *txb,
190                                rxrpc_notify_end_tx_t notify_end_tx)
191 {
192         rxrpc_seq_t seq = txb->seq;
193         bool last = test_bit(RXRPC_TXBUF_LAST, &txb->flags), poke;
194
195         rxrpc_inc_stat(call->rxnet, stat_tx_data);
196
197         ASSERTCMP(txb->seq, ==, call->tx_prepared + 1);
198
199         /* We have to set the timestamp before queueing as the retransmit
200          * algorithm can see the packet as soon as we queue it.
201          */
202         txb->last_sent = ktime_get_real();
203
204         if (last)
205                 trace_rxrpc_txqueue(call, rxrpc_txqueue_queue_last);
206         else
207                 trace_rxrpc_txqueue(call, rxrpc_txqueue_queue);
208
209         /* Add the packet to the call's output buffer */
210         spin_lock(&call->tx_lock);
211         poke = list_empty(&call->tx_sendmsg);
212         list_add_tail(&txb->call_link, &call->tx_sendmsg);
213         call->tx_prepared = seq;
214         if (last)
215                 rxrpc_notify_end_tx(rx, call, notify_end_tx);
216         spin_unlock(&call->tx_lock);
217
218         if (poke)
219                 rxrpc_poke_call(call, rxrpc_call_poke_start);
220 }
221
222 /*
223  * send data through a socket
224  * - must be called in process context
225  * - The caller holds the call user access mutex, but not the socket lock.
226  */
227 static int rxrpc_send_data(struct rxrpc_sock *rx,
228                            struct rxrpc_call *call,
229                            struct msghdr *msg, size_t len,
230                            rxrpc_notify_end_tx_t notify_end_tx,
231                            bool *_dropped_lock)
232 {
233         struct rxrpc_txbuf *txb;
234         struct sock *sk = &rx->sk;
235         enum rxrpc_call_state state;
236         long timeo;
237         bool more = msg->msg_flags & MSG_MORE;
238         int ret, copied = 0;
239
240         timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
241
242         /* this should be in poll */
243         sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
244
245 reload:
246         ret = -EPIPE;
247         if (sk->sk_shutdown & SEND_SHUTDOWN)
248                 goto maybe_error;
249         state = rxrpc_call_state(call);
250         ret = -ESHUTDOWN;
251         if (state >= RXRPC_CALL_COMPLETE)
252                 goto maybe_error;
253         ret = -EPROTO;
254         if (state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
255             state != RXRPC_CALL_SERVER_ACK_REQUEST &&
256             state != RXRPC_CALL_SERVER_SEND_REPLY) {
257                 /* Request phase complete for this client call */
258                 trace_rxrpc_abort(call->debug_id, rxrpc_sendmsg_late_send,
259                                   call->cid, call->call_id, call->rx_consumed,
260                                   0, -EPROTO);
261                 goto maybe_error;
262         }
263
264         ret = -EMSGSIZE;
265         if (call->tx_total_len != -1) {
266                 if (len - copied > call->tx_total_len)
267                         goto maybe_error;
268                 if (!more && len - copied != call->tx_total_len)
269                         goto maybe_error;
270         }
271
272         txb = call->tx_pending;
273         call->tx_pending = NULL;
274         if (txb)
275                 rxrpc_see_txbuf(txb, rxrpc_txbuf_see_send_more);
276
277         do {
278                 if (!txb) {
279                         size_t remain, bufsize, chunk, offset;
280
281                         _debug("alloc");
282
283                         if (!rxrpc_check_tx_space(call, NULL))
284                                 goto wait_for_space;
285
286                         /* Work out the maximum size of a packet.  Assume that
287                          * the security header is going to be in the padded
288                          * region (enc blocksize), but the trailer is not.
289                          */
290                         remain = more ? INT_MAX : msg_data_left(msg);
291                         ret = call->conn->security->how_much_data(call, remain,
292                                                                   &bufsize, &chunk, &offset);
293                         if (ret < 0)
294                                 goto maybe_error;
295
296                         _debug("SIZE: %zu/%zu @%zu", chunk, bufsize, offset);
297
298                         /* create a buffer that we can retain until it's ACK'd */
299                         ret = -ENOMEM;
300                         txb = rxrpc_alloc_txbuf(call, RXRPC_PACKET_TYPE_DATA,
301                                                 GFP_KERNEL);
302                         if (!txb)
303                                 goto maybe_error;
304
305                         txb->offset = offset;
306                         txb->space -= offset;
307                         txb->space = min_t(size_t, chunk, txb->space);
308                 }
309
310                 _debug("append");
311
312                 /* append next segment of data to the current buffer */
313                 if (msg_data_left(msg) > 0) {
314                         size_t copy = min_t(size_t, txb->space, msg_data_left(msg));
315
316                         _debug("add %zu", copy);
317                         if (!copy_from_iter_full(txb->data + txb->offset, copy,
318                                                  &msg->msg_iter))
319                                 goto efault;
320                         _debug("added");
321                         txb->space -= copy;
322                         txb->len += copy;
323                         txb->offset += copy;
324                         copied += copy;
325                         if (call->tx_total_len != -1)
326                                 call->tx_total_len -= copy;
327                 }
328
329                 /* check for the far side aborting the call or a network error
330                  * occurring */
331                 if (rxrpc_call_is_complete(call))
332                         goto call_terminated;
333
334                 /* add the packet to the send queue if it's now full */
335                 if (!txb->space ||
336                     (msg_data_left(msg) == 0 && !more)) {
337                         if (msg_data_left(msg) == 0 && !more) {
338                                 txb->wire.flags |= RXRPC_LAST_PACKET;
339                                 __set_bit(RXRPC_TXBUF_LAST, &txb->flags);
340                         }
341                         else if (call->tx_top - call->acks_hard_ack <
342                                  call->tx_winsize)
343                                 txb->wire.flags |= RXRPC_MORE_PACKETS;
344
345                         ret = call->security->secure_packet(call, txb);
346                         if (ret < 0)
347                                 goto out;
348
349                         rxrpc_queue_packet(rx, call, txb, notify_end_tx);
350                         txb = NULL;
351                 }
352         } while (msg_data_left(msg) > 0);
353
354 success:
355         ret = copied;
356         if (rxrpc_call_is_complete(call) &&
357             call->error < 0)
358                 ret = call->error;
359 out:
360         call->tx_pending = txb;
361         _leave(" = %d", ret);
362         return ret;
363
364 call_terminated:
365         rxrpc_put_txbuf(txb, rxrpc_txbuf_put_send_aborted);
366         _leave(" = %d", call->error);
367         return call->error;
368
369 maybe_error:
370         if (copied)
371                 goto success;
372         goto out;
373
374 efault:
375         ret = -EFAULT;
376         goto out;
377
378 wait_for_space:
379         ret = -EAGAIN;
380         if (msg->msg_flags & MSG_DONTWAIT)
381                 goto maybe_error;
382         mutex_unlock(&call->user_mutex);
383         *_dropped_lock = true;
384         ret = rxrpc_wait_for_tx_window(rx, call, &timeo,
385                                        msg->msg_flags & MSG_WAITALL);
386         if (ret < 0)
387                 goto maybe_error;
388         if (call->interruptibility == RXRPC_INTERRUPTIBLE) {
389                 if (mutex_lock_interruptible(&call->user_mutex) < 0) {
390                         ret = sock_intr_errno(timeo);
391                         goto maybe_error;
392                 }
393         } else {
394                 mutex_lock(&call->user_mutex);
395         }
396         *_dropped_lock = false;
397         goto reload;
398 }
399
400 /*
401  * extract control messages from the sendmsg() control buffer
402  */
403 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
404 {
405         struct cmsghdr *cmsg;
406         bool got_user_ID = false;
407         int len;
408
409         if (msg->msg_controllen == 0)
410                 return -EINVAL;
411
412         for_each_cmsghdr(cmsg, msg) {
413                 if (!CMSG_OK(msg, cmsg))
414                         return -EINVAL;
415
416                 len = cmsg->cmsg_len - sizeof(struct cmsghdr);
417                 _debug("CMSG %d, %d, %d",
418                        cmsg->cmsg_level, cmsg->cmsg_type, len);
419
420                 if (cmsg->cmsg_level != SOL_RXRPC)
421                         continue;
422
423                 switch (cmsg->cmsg_type) {
424                 case RXRPC_USER_CALL_ID:
425                         if (msg->msg_flags & MSG_CMSG_COMPAT) {
426                                 if (len != sizeof(u32))
427                                         return -EINVAL;
428                                 p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
429                         } else {
430                                 if (len != sizeof(unsigned long))
431                                         return -EINVAL;
432                                 p->call.user_call_ID = *(unsigned long *)
433                                         CMSG_DATA(cmsg);
434                         }
435                         got_user_ID = true;
436                         break;
437
438                 case RXRPC_ABORT:
439                         if (p->command != RXRPC_CMD_SEND_DATA)
440                                 return -EINVAL;
441                         p->command = RXRPC_CMD_SEND_ABORT;
442                         if (len != sizeof(p->abort_code))
443                                 return -EINVAL;
444                         p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
445                         if (p->abort_code == 0)
446                                 return -EINVAL;
447                         break;
448
449                 case RXRPC_CHARGE_ACCEPT:
450                         if (p->command != RXRPC_CMD_SEND_DATA)
451                                 return -EINVAL;
452                         p->command = RXRPC_CMD_CHARGE_ACCEPT;
453                         if (len != 0)
454                                 return -EINVAL;
455                         break;
456
457                 case RXRPC_EXCLUSIVE_CALL:
458                         p->exclusive = true;
459                         if (len != 0)
460                                 return -EINVAL;
461                         break;
462
463                 case RXRPC_UPGRADE_SERVICE:
464                         p->upgrade = true;
465                         if (len != 0)
466                                 return -EINVAL;
467                         break;
468
469                 case RXRPC_TX_LENGTH:
470                         if (p->call.tx_total_len != -1 || len != sizeof(__s64))
471                                 return -EINVAL;
472                         p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
473                         if (p->call.tx_total_len < 0)
474                                 return -EINVAL;
475                         break;
476
477                 case RXRPC_SET_CALL_TIMEOUT:
478                         if (len & 3 || len < 4 || len > 12)
479                                 return -EINVAL;
480                         memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
481                         p->call.nr_timeouts = len / 4;
482                         if (p->call.timeouts.hard > INT_MAX / HZ)
483                                 return -ERANGE;
484                         if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
485                                 return -ERANGE;
486                         if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
487                                 return -ERANGE;
488                         break;
489
490                 default:
491                         return -EINVAL;
492                 }
493         }
494
495         if (!got_user_ID)
496                 return -EINVAL;
497         if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
498                 return -EINVAL;
499         _leave(" = 0");
500         return 0;
501 }
502
503 /*
504  * Create a new client call for sendmsg().
505  * - Called with the socket lock held, which it must release.
506  * - If it returns a call, the call's lock will need releasing by the caller.
507  */
508 static struct rxrpc_call *
509 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
510                                   struct rxrpc_send_params *p)
511         __releases(&rx->sk.sk_lock.slock)
512         __acquires(&call->user_mutex)
513 {
514         struct rxrpc_conn_parameters cp;
515         struct rxrpc_call *call;
516         struct key *key;
517
518         DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
519
520         _enter("");
521
522         if (!msg->msg_name) {
523                 release_sock(&rx->sk);
524                 return ERR_PTR(-EDESTADDRREQ);
525         }
526
527         key = rx->key;
528         if (key && !rx->key->payload.data[0])
529                 key = NULL;
530
531         memset(&cp, 0, sizeof(cp));
532         cp.local                = rx->local;
533         cp.key                  = rx->key;
534         cp.security_level       = rx->min_sec_level;
535         cp.exclusive            = rx->exclusive | p->exclusive;
536         cp.upgrade              = p->upgrade;
537         cp.service_id           = srx->srx_service;
538         call = rxrpc_new_client_call(rx, &cp, srx, &p->call, GFP_KERNEL,
539                                      atomic_inc_return(&rxrpc_debug_id));
540         /* The socket is now unlocked */
541
542         _leave(" = %p\n", call);
543         return call;
544 }
545
546 /*
547  * send a message forming part of a client call through an RxRPC socket
548  * - caller holds the socket locked
549  * - the socket may be either a client socket or a server socket
550  */
551 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
552         __releases(&rx->sk.sk_lock.slock)
553 {
554         struct rxrpc_call *call;
555         unsigned long now, j;
556         bool dropped_lock = false;
557         int ret;
558
559         struct rxrpc_send_params p = {
560                 .call.tx_total_len      = -1,
561                 .call.user_call_ID      = 0,
562                 .call.nr_timeouts       = 0,
563                 .call.interruptibility  = RXRPC_INTERRUPTIBLE,
564                 .abort_code             = 0,
565                 .command                = RXRPC_CMD_SEND_DATA,
566                 .exclusive              = false,
567                 .upgrade                = false,
568         };
569
570         _enter("");
571
572         ret = rxrpc_sendmsg_cmsg(msg, &p);
573         if (ret < 0)
574                 goto error_release_sock;
575
576         if (p.command == RXRPC_CMD_CHARGE_ACCEPT) {
577                 ret = -EINVAL;
578                 if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
579                         goto error_release_sock;
580                 ret = rxrpc_user_charge_accept(rx, p.call.user_call_ID);
581                 goto error_release_sock;
582         }
583
584         call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
585         if (!call) {
586                 ret = -EBADSLT;
587                 if (p.command != RXRPC_CMD_SEND_DATA)
588                         goto error_release_sock;
589                 call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
590                 /* The socket is now unlocked... */
591                 if (IS_ERR(call))
592                         return PTR_ERR(call);
593                 /* ... and we have the call lock. */
594                 ret = 0;
595                 if (rxrpc_call_is_complete(call))
596                         goto out_put_unlock;
597         } else {
598                 switch (rxrpc_call_state(call)) {
599                 case RXRPC_CALL_UNINITIALISED:
600                 case RXRPC_CALL_CLIENT_AWAIT_CONN:
601                 case RXRPC_CALL_SERVER_PREALLOC:
602                 case RXRPC_CALL_SERVER_SECURING:
603                         rxrpc_put_call(call, rxrpc_call_put_sendmsg);
604                         ret = -EBUSY;
605                         goto error_release_sock;
606                 default:
607                         break;
608                 }
609
610                 ret = mutex_lock_interruptible(&call->user_mutex);
611                 release_sock(&rx->sk);
612                 if (ret < 0) {
613                         ret = -ERESTARTSYS;
614                         goto error_put;
615                 }
616
617                 if (p.call.tx_total_len != -1) {
618                         ret = -EINVAL;
619                         if (call->tx_total_len != -1 ||
620                             call->tx_pending ||
621                             call->tx_top != 0)
622                                 goto out_put_unlock;
623                         call->tx_total_len = p.call.tx_total_len;
624                 }
625         }
626
627         switch (p.call.nr_timeouts) {
628         case 3:
629                 j = msecs_to_jiffies(p.call.timeouts.normal);
630                 if (p.call.timeouts.normal > 0 && j == 0)
631                         j = 1;
632                 WRITE_ONCE(call->next_rx_timo, j);
633                 fallthrough;
634         case 2:
635                 j = msecs_to_jiffies(p.call.timeouts.idle);
636                 if (p.call.timeouts.idle > 0 && j == 0)
637                         j = 1;
638                 WRITE_ONCE(call->next_req_timo, j);
639                 fallthrough;
640         case 1:
641                 if (p.call.timeouts.hard > 0) {
642                         j = msecs_to_jiffies(p.call.timeouts.hard);
643                         now = jiffies;
644                         j += now;
645                         WRITE_ONCE(call->expect_term_by, j);
646                         rxrpc_reduce_call_timer(call, j, now,
647                                                 rxrpc_timer_set_for_hard);
648                 }
649                 break;
650         }
651
652         if (rxrpc_call_is_complete(call)) {
653                 /* it's too late for this call */
654                 ret = -ESHUTDOWN;
655         } else if (p.command == RXRPC_CMD_SEND_ABORT) {
656                 rxrpc_propose_abort(call, p.abort_code, -ECONNABORTED,
657                                     rxrpc_abort_call_sendmsg);
658                 ret = 0;
659         } else if (p.command != RXRPC_CMD_SEND_DATA) {
660                 ret = -EINVAL;
661         } else {
662                 ret = rxrpc_send_data(rx, call, msg, len, NULL, &dropped_lock);
663         }
664
665 out_put_unlock:
666         if (!dropped_lock)
667                 mutex_unlock(&call->user_mutex);
668 error_put:
669         rxrpc_put_call(call, rxrpc_call_put_sendmsg);
670         _leave(" = %d", ret);
671         return ret;
672
673 error_release_sock:
674         release_sock(&rx->sk);
675         return ret;
676 }
677
678 /**
679  * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
680  * @sock: The socket the call is on
681  * @call: The call to send data through
682  * @msg: The data to send
683  * @len: The amount of data to send
684  * @notify_end_tx: Notification that the last packet is queued.
685  *
686  * Allow a kernel service to send data on a call.  The call must be in an state
687  * appropriate to sending data.  No control data should be supplied in @msg,
688  * nor should an address be supplied.  MSG_MORE should be flagged if there's
689  * more data to come, otherwise this data will end the transmission phase.
690  */
691 int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
692                            struct msghdr *msg, size_t len,
693                            rxrpc_notify_end_tx_t notify_end_tx)
694 {
695         bool dropped_lock = false;
696         int ret;
697
698         _enter("{%d},", call->debug_id);
699
700         ASSERTCMP(msg->msg_name, ==, NULL);
701         ASSERTCMP(msg->msg_control, ==, NULL);
702
703         mutex_lock(&call->user_mutex);
704
705         ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
706                               notify_end_tx, &dropped_lock);
707         if (ret == -ESHUTDOWN)
708                 ret = call->error;
709
710         if (!dropped_lock)
711                 mutex_unlock(&call->user_mutex);
712         _leave(" = %d", ret);
713         return ret;
714 }
715 EXPORT_SYMBOL(rxrpc_kernel_send_data);
716
717 /**
718  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
719  * @sock: The socket the call is on
720  * @call: The call to be aborted
721  * @abort_code: The abort code to stick into the ABORT packet
722  * @error: Local error value
723  * @why: Indication as to why.
724  *
725  * Allow a kernel service to abort a call, if it's still in an abortable state
726  * and return true if the call was aborted, false if it was already complete.
727  */
728 bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
729                              u32 abort_code, int error, enum rxrpc_abort_reason why)
730 {
731         bool aborted;
732
733         _enter("{%d},%d,%d,%u", call->debug_id, abort_code, error, why);
734
735         mutex_lock(&call->user_mutex);
736         aborted = rxrpc_propose_abort(call, abort_code, error, why);
737         mutex_unlock(&call->user_mutex);
738         return aborted;
739 }
740 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
741
742 /**
743  * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
744  * @sock: The socket the call is on
745  * @call: The call to be informed
746  * @tx_total_len: The amount of data to be transmitted for this call
747  *
748  * Allow a kernel service to set the total transmit length on a call.  This
749  * allows buffer-to-packet encrypt-and-copy to be performed.
750  *
751  * This function is primarily for use for setting the reply length since the
752  * request length can be set when beginning the call.
753  */
754 void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
755                                 s64 tx_total_len)
756 {
757         WARN_ON(call->tx_total_len != -1);
758         call->tx_total_len = tx_total_len;
759 }
760 EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);