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rxrpc: Use negative error codes in rxrpc_call struct
[mirror_ubuntu-artful-kernel.git] / net / rxrpc / sendmsg.c
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 enum rxrpc_command {
25 RXRPC_CMD_SEND_DATA, /* send data message */
26 RXRPC_CMD_SEND_ABORT, /* request abort generation */
27 RXRPC_CMD_ACCEPT, /* [server] accept incoming call */
28 RXRPC_CMD_REJECT_BUSY, /* [server] reject a call as busy */
29 };
30
31 /*
32 * wait for space to appear in the transmit/ACK window
33 * - caller holds the socket locked
34 */
35 static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
36 struct rxrpc_call *call,
37 long *timeo)
38 {
39 DECLARE_WAITQUEUE(myself, current);
40 int ret;
41
42 _enter(",{%u,%u,%u}",
43 call->tx_hard_ack, call->tx_top, call->tx_winsize);
44
45 add_wait_queue(&call->waitq, &myself);
46
47 for (;;) {
48 set_current_state(TASK_INTERRUPTIBLE);
49 ret = 0;
50 if (call->tx_top - call->tx_hard_ack <
51 min_t(unsigned int, call->tx_winsize,
52 call->cong_cwnd + call->cong_extra))
53 break;
54 if (call->state >= RXRPC_CALL_COMPLETE) {
55 ret = -call->error;
56 break;
57 }
58 if (signal_pending(current)) {
59 ret = sock_intr_errno(*timeo);
60 break;
61 }
62
63 trace_rxrpc_transmit(call, rxrpc_transmit_wait);
64 mutex_unlock(&call->user_mutex);
65 *timeo = schedule_timeout(*timeo);
66 if (mutex_lock_interruptible(&call->user_mutex) < 0) {
67 ret = sock_intr_errno(*timeo);
68 break;
69 }
70 }
71
72 remove_wait_queue(&call->waitq, &myself);
73 set_current_state(TASK_RUNNING);
74 _leave(" = %d", ret);
75 return ret;
76 }
77
78 /*
79 * Schedule an instant Tx resend.
80 */
81 static inline void rxrpc_instant_resend(struct rxrpc_call *call, int ix)
82 {
83 spin_lock_bh(&call->lock);
84
85 if (call->state < RXRPC_CALL_COMPLETE) {
86 call->rxtx_annotations[ix] = RXRPC_TX_ANNO_RETRANS;
87 if (!test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
88 rxrpc_queue_call(call);
89 }
90
91 spin_unlock_bh(&call->lock);
92 }
93
94 /*
95 * Queue a DATA packet for transmission, set the resend timeout and send the
96 * packet immediately
97 */
98 static void rxrpc_queue_packet(struct rxrpc_call *call, struct sk_buff *skb,
99 bool last)
100 {
101 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
102 rxrpc_seq_t seq = sp->hdr.seq;
103 int ret, ix;
104 u8 annotation = RXRPC_TX_ANNO_UNACK;
105
106 _net("queue skb %p [%d]", skb, seq);
107
108 ASSERTCMP(seq, ==, call->tx_top + 1);
109
110 if (last)
111 annotation |= RXRPC_TX_ANNO_LAST;
112
113 /* We have to set the timestamp before queueing as the retransmit
114 * algorithm can see the packet as soon as we queue it.
115 */
116 skb->tstamp = ktime_get_real();
117
118 ix = seq & RXRPC_RXTX_BUFF_MASK;
119 rxrpc_get_skb(skb, rxrpc_skb_tx_got);
120 call->rxtx_annotations[ix] = annotation;
121 smp_wmb();
122 call->rxtx_buffer[ix] = skb;
123 call->tx_top = seq;
124 if (last)
125 trace_rxrpc_transmit(call, rxrpc_transmit_queue_last);
126 else
127 trace_rxrpc_transmit(call, rxrpc_transmit_queue);
128
129 if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {
130 _debug("________awaiting reply/ACK__________");
131 write_lock_bh(&call->state_lock);
132 switch (call->state) {
133 case RXRPC_CALL_CLIENT_SEND_REQUEST:
134 call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
135 break;
136 case RXRPC_CALL_SERVER_ACK_REQUEST:
137 call->state = RXRPC_CALL_SERVER_SEND_REPLY;
138 call->ack_at = call->expire_at;
139 if (call->ackr_reason == RXRPC_ACK_DELAY)
140 call->ackr_reason = 0;
141 __rxrpc_set_timer(call, rxrpc_timer_init_for_send_reply,
142 ktime_get_real());
143 if (!last)
144 break;
145 case RXRPC_CALL_SERVER_SEND_REPLY:
146 call->state = RXRPC_CALL_SERVER_AWAIT_ACK;
147 break;
148 default:
149 break;
150 }
151 write_unlock_bh(&call->state_lock);
152 }
153
154 if (seq == 1 && rxrpc_is_client_call(call))
155 rxrpc_expose_client_call(call);
156
157 ret = rxrpc_send_data_packet(call, skb, false);
158 if (ret < 0) {
159 _debug("need instant resend %d", ret);
160 rxrpc_instant_resend(call, ix);
161 } else {
162 ktime_t now = ktime_get_real(), resend_at;
163
164 resend_at = ktime_add_ms(now, rxrpc_resend_timeout);
165
166 if (ktime_before(resend_at, call->resend_at)) {
167 call->resend_at = resend_at;
168 rxrpc_set_timer(call, rxrpc_timer_set_for_send, now);
169 }
170 }
171
172 rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
173 _leave("");
174 }
175
176 /*
177 * send data through a socket
178 * - must be called in process context
179 * - The caller holds the call user access mutex, but not the socket lock.
180 */
181 static int rxrpc_send_data(struct rxrpc_sock *rx,
182 struct rxrpc_call *call,
183 struct msghdr *msg, size_t len)
184 {
185 struct rxrpc_skb_priv *sp;
186 struct sk_buff *skb;
187 struct sock *sk = &rx->sk;
188 long timeo;
189 bool more;
190 int ret, copied;
191
192 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
193
194 /* this should be in poll */
195 sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
196
197 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
198 return -EPIPE;
199
200 more = msg->msg_flags & MSG_MORE;
201
202 skb = call->tx_pending;
203 call->tx_pending = NULL;
204 rxrpc_see_skb(skb, rxrpc_skb_tx_seen);
205
206 copied = 0;
207 do {
208 /* Check to see if there's a ping ACK to reply to. */
209 if (call->ackr_reason == RXRPC_ACK_PING_RESPONSE)
210 rxrpc_send_ack_packet(call, false);
211
212 if (!skb) {
213 size_t size, chunk, max, space;
214
215 _debug("alloc");
216
217 if (call->tx_top - call->tx_hard_ack >=
218 min_t(unsigned int, call->tx_winsize,
219 call->cong_cwnd + call->cong_extra)) {
220 ret = -EAGAIN;
221 if (msg->msg_flags & MSG_DONTWAIT)
222 goto maybe_error;
223 ret = rxrpc_wait_for_tx_window(rx, call,
224 &timeo);
225 if (ret < 0)
226 goto maybe_error;
227 }
228
229 max = RXRPC_JUMBO_DATALEN;
230 max -= call->conn->security_size;
231 max &= ~(call->conn->size_align - 1UL);
232
233 chunk = max;
234 if (chunk > msg_data_left(msg) && !more)
235 chunk = msg_data_left(msg);
236
237 space = chunk + call->conn->size_align;
238 space &= ~(call->conn->size_align - 1UL);
239
240 size = space + call->conn->security_size;
241
242 _debug("SIZE: %zu/%zu/%zu", chunk, space, size);
243
244 /* create a buffer that we can retain until it's ACK'd */
245 skb = sock_alloc_send_skb(
246 sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
247 if (!skb)
248 goto maybe_error;
249
250 rxrpc_new_skb(skb, rxrpc_skb_tx_new);
251
252 _debug("ALLOC SEND %p", skb);
253
254 ASSERTCMP(skb->mark, ==, 0);
255
256 _debug("HS: %u", call->conn->security_size);
257 skb_reserve(skb, call->conn->security_size);
258 skb->len += call->conn->security_size;
259
260 sp = rxrpc_skb(skb);
261 sp->remain = chunk;
262 if (sp->remain > skb_tailroom(skb))
263 sp->remain = skb_tailroom(skb);
264
265 _net("skb: hr %d, tr %d, hl %d, rm %d",
266 skb_headroom(skb),
267 skb_tailroom(skb),
268 skb_headlen(skb),
269 sp->remain);
270
271 skb->ip_summed = CHECKSUM_UNNECESSARY;
272 }
273
274 _debug("append");
275 sp = rxrpc_skb(skb);
276
277 /* append next segment of data to the current buffer */
278 if (msg_data_left(msg) > 0) {
279 int copy = skb_tailroom(skb);
280 ASSERTCMP(copy, >, 0);
281 if (copy > msg_data_left(msg))
282 copy = msg_data_left(msg);
283 if (copy > sp->remain)
284 copy = sp->remain;
285
286 _debug("add");
287 ret = skb_add_data(skb, &msg->msg_iter, copy);
288 _debug("added");
289 if (ret < 0)
290 goto efault;
291 sp->remain -= copy;
292 skb->mark += copy;
293 copied += copy;
294 }
295
296 /* check for the far side aborting the call or a network error
297 * occurring */
298 if (call->state == RXRPC_CALL_COMPLETE)
299 goto call_terminated;
300
301 /* add the packet to the send queue if it's now full */
302 if (sp->remain <= 0 ||
303 (msg_data_left(msg) == 0 && !more)) {
304 struct rxrpc_connection *conn = call->conn;
305 uint32_t seq;
306 size_t pad;
307
308 /* pad out if we're using security */
309 if (conn->security_ix) {
310 pad = conn->security_size + skb->mark;
311 pad = conn->size_align - pad;
312 pad &= conn->size_align - 1;
313 _debug("pad %zu", pad);
314 if (pad)
315 memset(skb_put(skb, pad), 0, pad);
316 }
317
318 seq = call->tx_top + 1;
319
320 sp->hdr.seq = seq;
321 sp->hdr._rsvd = 0;
322 sp->hdr.flags = conn->out_clientflag;
323
324 if (msg_data_left(msg) == 0 && !more)
325 sp->hdr.flags |= RXRPC_LAST_PACKET;
326 else if (call->tx_top - call->tx_hard_ack <
327 call->tx_winsize)
328 sp->hdr.flags |= RXRPC_MORE_PACKETS;
329
330 ret = conn->security->secure_packet(
331 call, skb, skb->mark, skb->head);
332 if (ret < 0)
333 goto out;
334
335 rxrpc_queue_packet(call, skb, !msg_data_left(msg) && !more);
336 skb = NULL;
337 }
338 } while (msg_data_left(msg) > 0);
339
340 success:
341 ret = copied;
342 out:
343 call->tx_pending = skb;
344 _leave(" = %d", ret);
345 return ret;
346
347 call_terminated:
348 rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
349 _leave(" = %d", -call->error);
350 return -call->error;
351
352 maybe_error:
353 if (copied)
354 goto success;
355 goto out;
356
357 efault:
358 ret = -EFAULT;
359 goto out;
360 }
361
362 /*
363 * extract control messages from the sendmsg() control buffer
364 */
365 static int rxrpc_sendmsg_cmsg(struct msghdr *msg,
366 unsigned long *user_call_ID,
367 enum rxrpc_command *command,
368 u32 *abort_code,
369 bool *_exclusive)
370 {
371 struct cmsghdr *cmsg;
372 bool got_user_ID = false;
373 int len;
374
375 *command = RXRPC_CMD_SEND_DATA;
376
377 if (msg->msg_controllen == 0)
378 return -EINVAL;
379
380 for_each_cmsghdr(cmsg, msg) {
381 if (!CMSG_OK(msg, cmsg))
382 return -EINVAL;
383
384 len = cmsg->cmsg_len - sizeof(struct cmsghdr);
385 _debug("CMSG %d, %d, %d",
386 cmsg->cmsg_level, cmsg->cmsg_type, len);
387
388 if (cmsg->cmsg_level != SOL_RXRPC)
389 continue;
390
391 switch (cmsg->cmsg_type) {
392 case RXRPC_USER_CALL_ID:
393 if (msg->msg_flags & MSG_CMSG_COMPAT) {
394 if (len != sizeof(u32))
395 return -EINVAL;
396 *user_call_ID = *(u32 *) CMSG_DATA(cmsg);
397 } else {
398 if (len != sizeof(unsigned long))
399 return -EINVAL;
400 *user_call_ID = *(unsigned long *)
401 CMSG_DATA(cmsg);
402 }
403 _debug("User Call ID %lx", *user_call_ID);
404 got_user_ID = true;
405 break;
406
407 case RXRPC_ABORT:
408 if (*command != RXRPC_CMD_SEND_DATA)
409 return -EINVAL;
410 *command = RXRPC_CMD_SEND_ABORT;
411 if (len != sizeof(*abort_code))
412 return -EINVAL;
413 *abort_code = *(unsigned int *) CMSG_DATA(cmsg);
414 _debug("Abort %x", *abort_code);
415 if (*abort_code == 0)
416 return -EINVAL;
417 break;
418
419 case RXRPC_ACCEPT:
420 if (*command != RXRPC_CMD_SEND_DATA)
421 return -EINVAL;
422 *command = RXRPC_CMD_ACCEPT;
423 if (len != 0)
424 return -EINVAL;
425 break;
426
427 case RXRPC_EXCLUSIVE_CALL:
428 *_exclusive = true;
429 if (len != 0)
430 return -EINVAL;
431 break;
432 default:
433 return -EINVAL;
434 }
435 }
436
437 if (!got_user_ID)
438 return -EINVAL;
439 _leave(" = 0");
440 return 0;
441 }
442
443 /*
444 * Create a new client call for sendmsg().
445 * - Called with the socket lock held, which it must release.
446 * - If it returns a call, the call's lock will need releasing by the caller.
447 */
448 static struct rxrpc_call *
449 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
450 unsigned long user_call_ID, bool exclusive)
451 __releases(&rx->sk.sk_lock.slock)
452 {
453 struct rxrpc_conn_parameters cp;
454 struct rxrpc_call *call;
455 struct key *key;
456
457 DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
458
459 _enter("");
460
461 if (!msg->msg_name) {
462 release_sock(&rx->sk);
463 return ERR_PTR(-EDESTADDRREQ);
464 }
465
466 key = rx->key;
467 if (key && !rx->key->payload.data[0])
468 key = NULL;
469
470 memset(&cp, 0, sizeof(cp));
471 cp.local = rx->local;
472 cp.key = rx->key;
473 cp.security_level = rx->min_sec_level;
474 cp.exclusive = rx->exclusive | exclusive;
475 cp.service_id = srx->srx_service;
476 call = rxrpc_new_client_call(rx, &cp, srx, user_call_ID, GFP_KERNEL);
477 /* The socket is now unlocked */
478
479 _leave(" = %p\n", call);
480 return call;
481 }
482
483 /*
484 * send a message forming part of a client call through an RxRPC socket
485 * - caller holds the socket locked
486 * - the socket may be either a client socket or a server socket
487 */
488 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
489 __releases(&rx->sk.sk_lock.slock)
490 {
491 enum rxrpc_call_state state;
492 enum rxrpc_command cmd;
493 struct rxrpc_call *call;
494 unsigned long user_call_ID = 0;
495 bool exclusive = false;
496 u32 abort_code = 0;
497 int ret;
498
499 _enter("");
500
501 ret = rxrpc_sendmsg_cmsg(msg, &user_call_ID, &cmd, &abort_code,
502 &exclusive);
503 if (ret < 0)
504 goto error_release_sock;
505
506 if (cmd == RXRPC_CMD_ACCEPT) {
507 ret = -EINVAL;
508 if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
509 goto error_release_sock;
510 call = rxrpc_accept_call(rx, user_call_ID, NULL);
511 /* The socket is now unlocked. */
512 if (IS_ERR(call))
513 return PTR_ERR(call);
514 rxrpc_put_call(call, rxrpc_call_put);
515 return 0;
516 }
517
518 call = rxrpc_find_call_by_user_ID(rx, user_call_ID);
519 if (!call) {
520 ret = -EBADSLT;
521 if (cmd != RXRPC_CMD_SEND_DATA)
522 goto error_release_sock;
523 call = rxrpc_new_client_call_for_sendmsg(rx, msg, user_call_ID,
524 exclusive);
525 /* The socket is now unlocked... */
526 if (IS_ERR(call))
527 return PTR_ERR(call);
528 /* ... and we have the call lock. */
529 } else {
530 switch (READ_ONCE(call->state)) {
531 case RXRPC_CALL_UNINITIALISED:
532 case RXRPC_CALL_CLIENT_AWAIT_CONN:
533 case RXRPC_CALL_SERVER_PREALLOC:
534 case RXRPC_CALL_SERVER_SECURING:
535 case RXRPC_CALL_SERVER_ACCEPTING:
536 ret = -EBUSY;
537 goto error_release_sock;
538 default:
539 break;
540 }
541
542 ret = mutex_lock_interruptible(&call->user_mutex);
543 release_sock(&rx->sk);
544 if (ret < 0) {
545 ret = -ERESTARTSYS;
546 goto error_put;
547 }
548 }
549
550 state = READ_ONCE(call->state);
551 _debug("CALL %d USR %lx ST %d on CONN %p",
552 call->debug_id, call->user_call_ID, state, call->conn);
553
554 if (state >= RXRPC_CALL_COMPLETE) {
555 /* it's too late for this call */
556 ret = -ESHUTDOWN;
557 } else if (cmd == RXRPC_CMD_SEND_ABORT) {
558 ret = 0;
559 if (rxrpc_abort_call("CMD", call, 0, abort_code, -ECONNABORTED))
560 ret = rxrpc_send_abort_packet(call);
561 } else if (cmd != RXRPC_CMD_SEND_DATA) {
562 ret = -EINVAL;
563 } else if (rxrpc_is_client_call(call) &&
564 state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
565 /* request phase complete for this client call */
566 ret = -EPROTO;
567 } else if (rxrpc_is_service_call(call) &&
568 state != RXRPC_CALL_SERVER_ACK_REQUEST &&
569 state != RXRPC_CALL_SERVER_SEND_REPLY) {
570 /* Reply phase not begun or not complete for service call. */
571 ret = -EPROTO;
572 } else {
573 ret = rxrpc_send_data(rx, call, msg, len);
574 }
575
576 mutex_unlock(&call->user_mutex);
577 error_put:
578 rxrpc_put_call(call, rxrpc_call_put);
579 _leave(" = %d", ret);
580 return ret;
581
582 error_release_sock:
583 release_sock(&rx->sk);
584 return ret;
585 }
586
587 /**
588 * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
589 * @sock: The socket the call is on
590 * @call: The call to send data through
591 * @msg: The data to send
592 * @len: The amount of data to send
593 *
594 * Allow a kernel service to send data on a call. The call must be in an state
595 * appropriate to sending data. No control data should be supplied in @msg,
596 * nor should an address be supplied. MSG_MORE should be flagged if there's
597 * more data to come, otherwise this data will end the transmission phase.
598 */
599 int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
600 struct msghdr *msg, size_t len)
601 {
602 int ret;
603
604 _enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
605
606 ASSERTCMP(msg->msg_name, ==, NULL);
607 ASSERTCMP(msg->msg_control, ==, NULL);
608
609 mutex_lock(&call->user_mutex);
610
611 _debug("CALL %d USR %lx ST %d on CONN %p",
612 call->debug_id, call->user_call_ID, call->state, call->conn);
613
614 switch (READ_ONCE(call->state)) {
615 case RXRPC_CALL_CLIENT_SEND_REQUEST:
616 case RXRPC_CALL_SERVER_ACK_REQUEST:
617 case RXRPC_CALL_SERVER_SEND_REPLY:
618 ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len);
619 break;
620 case RXRPC_CALL_COMPLETE:
621 read_lock_bh(&call->state_lock);
622 ret = -call->error;
623 read_unlock_bh(&call->state_lock);
624 break;
625 default:
626 /* Request phase complete for this client call */
627 ret = -EPROTO;
628 break;
629 }
630
631 mutex_unlock(&call->user_mutex);
632 _leave(" = %d", ret);
633 return ret;
634 }
635 EXPORT_SYMBOL(rxrpc_kernel_send_data);
636
637 /**
638 * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
639 * @sock: The socket the call is on
640 * @call: The call to be aborted
641 * @abort_code: The abort code to stick into the ABORT packet
642 * @error: Local error value
643 * @why: 3-char string indicating why.
644 *
645 * Allow a kernel service to abort a call, if it's still in an abortable state.
646 */
647 void rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
648 u32 abort_code, int error, const char *why)
649 {
650 _enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
651
652 mutex_lock(&call->user_mutex);
653
654 if (rxrpc_abort_call(why, call, 0, abort_code, error))
655 rxrpc_send_abort_packet(call);
656
657 mutex_unlock(&call->user_mutex);
658 _leave("");
659 }
660
661 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
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