1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* incoming call handling
3 *
4 * Copyright (C) 2007 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/module.h>
11 #include <linux/net.h>
12 #include <linux/skbuff.h>
13 #include <linux/errqueue.h>
14 #include <linux/udp.h>
15 #include <linux/in.h>
16 #include <linux/in6.h>
17 #include <linux/icmp.h>
18 #include <linux/gfp.h>
19 #include <linux/circ_buf.h>
20 #include <net/sock.h>
21 #include <net/af_rxrpc.h>
22 #include <net/ip.h>
23 #include "ar-internal.h"
24
25 /*
26 * Preallocate a single service call, connection and peer and, if possible,
27 * give them a user ID and attach the user's side of the ID to them.
28 */
rxrpc_service_prealloc_one(struct rxrpc_sock * rx,struct rxrpc_backlog * b,rxrpc_notify_rx_t notify_rx,rxrpc_user_attach_call_t user_attach_call,unsigned long user_call_ID,gfp_t gfp,unsigned int debug_id)29 static int rxrpc_service_prealloc_one(struct rxrpc_sock *rx,
30 struct rxrpc_backlog *b,
31 rxrpc_notify_rx_t notify_rx,
32 rxrpc_user_attach_call_t user_attach_call,
33 unsigned long user_call_ID, gfp_t gfp,
34 unsigned int debug_id)
35 {
36 const void *here = __builtin_return_address(0);
37 struct rxrpc_call *call;
38 struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk));
39 int max, tmp;
40 unsigned int size = RXRPC_BACKLOG_MAX;
41 unsigned int head, tail, call_head, call_tail;
42
43 max = rx->sk.sk_max_ack_backlog;
44 tmp = rx->sk.sk_ack_backlog;
45 if (tmp >= max) {
46 _leave(" = -ENOBUFS [full %u]", max);
47 return -ENOBUFS;
48 }
49 max -= tmp;
50
51 /* We don't need more conns and peers than we have calls, but on the
52 * other hand, we shouldn't ever use more peers than conns or conns
53 * than calls.
54 */
55 call_head = b->call_backlog_head;
56 call_tail = READ_ONCE(b->call_backlog_tail);
57 tmp = CIRC_CNT(call_head, call_tail, size);
58 if (tmp >= max) {
59 _leave(" = -ENOBUFS [enough %u]", tmp);
60 return -ENOBUFS;
61 }
62 max = tmp + 1;
63
64 head = b->peer_backlog_head;
65 tail = READ_ONCE(b->peer_backlog_tail);
66 if (CIRC_CNT(head, tail, size) < max) {
67 struct rxrpc_peer *peer = rxrpc_alloc_peer(rx->local, gfp);
68 if (!peer)
69 return -ENOMEM;
70 b->peer_backlog[head] = peer;
71 smp_store_release(&b->peer_backlog_head,
72 (head + 1) & (size - 1));
73 }
74
75 head = b->conn_backlog_head;
76 tail = READ_ONCE(b->conn_backlog_tail);
77 if (CIRC_CNT(head, tail, size) < max) {
78 struct rxrpc_connection *conn;
79
80 conn = rxrpc_prealloc_service_connection(rxnet, gfp);
81 if (!conn)
82 return -ENOMEM;
83 b->conn_backlog[head] = conn;
84 smp_store_release(&b->conn_backlog_head,
85 (head + 1) & (size - 1));
86
87 trace_rxrpc_conn(conn->debug_id, rxrpc_conn_new_service,
88 atomic_read(&conn->usage), here);
89 }
90
91 /* Now it gets complicated, because calls get registered with the
92 * socket here, particularly if a user ID is preassigned by the user.
93 */
94 call = rxrpc_alloc_call(rx, gfp, debug_id);
95 if (!call)
96 return -ENOMEM;
97 call->flags |= (1 << RXRPC_CALL_IS_SERVICE);
98 call->state = RXRPC_CALL_SERVER_PREALLOC;
99
100 trace_rxrpc_call(call->debug_id, rxrpc_call_new_service,
101 atomic_read(&call->usage),
102 here, (const void *)user_call_ID);
103
104 write_lock(&rx->call_lock);
105 if (user_attach_call) {
106 struct rxrpc_call *xcall;
107 struct rb_node *parent, **pp;
108
109 /* Check the user ID isn't already in use */
110 pp = &rx->calls.rb_node;
111 parent = NULL;
112 while (*pp) {
113 parent = *pp;
114 xcall = rb_entry(parent, struct rxrpc_call, sock_node);
115 if (user_call_ID < xcall->user_call_ID)
116 pp = &(*pp)->rb_left;
117 else if (user_call_ID > xcall->user_call_ID)
118 pp = &(*pp)->rb_right;
119 else
120 goto id_in_use;
121 }
122
123 call->user_call_ID = user_call_ID;
124 call->notify_rx = notify_rx;
125 rxrpc_get_call(call, rxrpc_call_got_kernel);
126 user_attach_call(call, user_call_ID);
127 rxrpc_get_call(call, rxrpc_call_got_userid);
128 rb_link_node(&call->sock_node, parent, pp);
129 rb_insert_color(&call->sock_node, &rx->calls);
130 set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
131 }
132
133 list_add(&call->sock_link, &rx->sock_calls);
134
135 write_unlock(&rx->call_lock);
136
137 rxnet = call->rxnet;
138 write_lock(&rxnet->call_lock);
139 list_add_tail(&call->link, &rxnet->calls);
140 write_unlock(&rxnet->call_lock);
141
142 b->call_backlog[call_head] = call;
143 smp_store_release(&b->call_backlog_head, (call_head + 1) & (size - 1));
144 _leave(" = 0 [%d -> %lx]", call->debug_id, user_call_ID);
145 return 0;
146
147 id_in_use:
148 write_unlock(&rx->call_lock);
149 rxrpc_cleanup_call(call);
150 _leave(" = -EBADSLT");
151 return -EBADSLT;
152 }
153
154 /*
155 * Preallocate sufficient service connections, calls and peers to cover the
156 * entire backlog of a socket. When a new call comes in, if we don't have
157 * sufficient of each available, the call gets rejected as busy or ignored.
158 *
159 * The backlog is replenished when a connection is accepted or rejected.
160 */
rxrpc_service_prealloc(struct rxrpc_sock * rx,gfp_t gfp)161 int rxrpc_service_prealloc(struct rxrpc_sock *rx, gfp_t gfp)
162 {
163 struct rxrpc_backlog *b = rx->backlog;
164
165 if (!b) {
166 b = kzalloc(sizeof(struct rxrpc_backlog), gfp);
167 if (!b)
168 return -ENOMEM;
169 rx->backlog = b;
170 }
171
172 if (rx->discard_new_call)
173 return 0;
174
175 while (rxrpc_service_prealloc_one(rx, b, NULL, NULL, 0, gfp,
176 atomic_inc_return(&rxrpc_debug_id)) == 0)
177 ;
178
179 return 0;
180 }
181
182 /*
183 * Discard the preallocation on a service.
184 */
rxrpc_discard_prealloc(struct rxrpc_sock * rx)185 void rxrpc_discard_prealloc(struct rxrpc_sock *rx)
186 {
187 struct rxrpc_backlog *b = rx->backlog;
188 struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk));
189 unsigned int size = RXRPC_BACKLOG_MAX, head, tail;
190
191 if (!b)
192 return;
193 rx->backlog = NULL;
194
195 /* Make sure that there aren't any incoming calls in progress before we
196 * clear the preallocation buffers.
197 */
198 spin_lock_bh(&rx->incoming_lock);
199 spin_unlock_bh(&rx->incoming_lock);
200
201 head = b->peer_backlog_head;
202 tail = b->peer_backlog_tail;
203 while (CIRC_CNT(head, tail, size) > 0) {
204 struct rxrpc_peer *peer = b->peer_backlog[tail];
205 kfree(peer);
206 tail = (tail + 1) & (size - 1);
207 }
208
209 head = b->conn_backlog_head;
210 tail = b->conn_backlog_tail;
211 while (CIRC_CNT(head, tail, size) > 0) {
212 struct rxrpc_connection *conn = b->conn_backlog[tail];
213 write_lock(&rxnet->conn_lock);
214 list_del(&conn->link);
215 list_del(&conn->proc_link);
216 write_unlock(&rxnet->conn_lock);
217 kfree(conn);
218 if (atomic_dec_and_test(&rxnet->nr_conns))
219 wake_up_var(&rxnet->nr_conns);
220 tail = (tail + 1) & (size - 1);
221 }
222
223 head = b->call_backlog_head;
224 tail = b->call_backlog_tail;
225 while (CIRC_CNT(head, tail, size) > 0) {
226 struct rxrpc_call *call = b->call_backlog[tail];
227 rcu_assign_pointer(call->socket, rx);
228 if (rx->discard_new_call) {
229 _debug("discard %lx", call->user_call_ID);
230 rx->discard_new_call(call, call->user_call_ID);
231 rxrpc_put_call(call, rxrpc_call_put_kernel);
232 }
233 rxrpc_call_completed(call);
234 rxrpc_release_call(rx, call);
235 rxrpc_put_call(call, rxrpc_call_put);
236 tail = (tail + 1) & (size - 1);
237 }
238
239 kfree(b);
240 }
241
242 /*
243 * Ping the other end to fill our RTT cache and to retrieve the rwind
244 * and MTU parameters.
245 */
rxrpc_send_ping(struct rxrpc_call * call,struct sk_buff * skb)246 static void rxrpc_send_ping(struct rxrpc_call *call, struct sk_buff *skb)
247 {
248 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
249 ktime_t now = skb->tstamp;
250
251 if (call->peer->rtt_usage < 3 ||
252 ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000), now))
253 rxrpc_propose_ACK(call, RXRPC_ACK_PING, sp->hdr.serial,
254 true, true,
255 rxrpc_propose_ack_ping_for_params);
256 }
257
258 /*
259 * Allocate a new incoming call from the prealloc pool, along with a connection
260 * and a peer as necessary.
261 */
rxrpc_alloc_incoming_call(struct rxrpc_sock * rx,struct rxrpc_local * local,struct rxrpc_peer * peer,struct rxrpc_connection * conn,const struct rxrpc_security * sec,struct key * key,struct sk_buff * skb)262 static struct rxrpc_call *rxrpc_alloc_incoming_call(struct rxrpc_sock *rx,
263 struct rxrpc_local *local,
264 struct rxrpc_peer *peer,
265 struct rxrpc_connection *conn,
266 const struct rxrpc_security *sec,
267 struct key *key,
268 struct sk_buff *skb)
269 {
270 struct rxrpc_backlog *b = rx->backlog;
271 struct rxrpc_call *call;
272 unsigned short call_head, conn_head, peer_head;
273 unsigned short call_tail, conn_tail, peer_tail;
274 unsigned short call_count, conn_count;
275
276 /* #calls >= #conns >= #peers must hold true. */
277 call_head = smp_load_acquire(&b->call_backlog_head);
278 call_tail = b->call_backlog_tail;
279 call_count = CIRC_CNT(call_head, call_tail, RXRPC_BACKLOG_MAX);
280 conn_head = smp_load_acquire(&b->conn_backlog_head);
281 conn_tail = b->conn_backlog_tail;
282 conn_count = CIRC_CNT(conn_head, conn_tail, RXRPC_BACKLOG_MAX);
283 ASSERTCMP(conn_count, >=, call_count);
284 peer_head = smp_load_acquire(&b->peer_backlog_head);
285 peer_tail = b->peer_backlog_tail;
286 ASSERTCMP(CIRC_CNT(peer_head, peer_tail, RXRPC_BACKLOG_MAX), >=,
287 conn_count);
288
289 if (call_count == 0)
290 return NULL;
291
292 if (!conn) {
293 if (peer && !rxrpc_get_peer_maybe(peer))
294 peer = NULL;
295 if (!peer) {
296 peer = b->peer_backlog[peer_tail];
297 if (rxrpc_extract_addr_from_skb(&peer->srx, skb) < 0)
298 return NULL;
299 b->peer_backlog[peer_tail] = NULL;
300 smp_store_release(&b->peer_backlog_tail,
301 (peer_tail + 1) &
302 (RXRPC_BACKLOG_MAX - 1));
303
304 rxrpc_new_incoming_peer(rx, local, peer);
305 }
306
307 /* Now allocate and set up the connection */
308 conn = b->conn_backlog[conn_tail];
309 b->conn_backlog[conn_tail] = NULL;
310 smp_store_release(&b->conn_backlog_tail,
311 (conn_tail + 1) & (RXRPC_BACKLOG_MAX - 1));
312 conn->params.local = rxrpc_get_local(local);
313 conn->params.peer = peer;
314 rxrpc_see_connection(conn);
315 rxrpc_new_incoming_connection(rx, conn, sec, key, skb);
316 } else {
317 rxrpc_get_connection(conn);
318 }
319
320 /* And now we can allocate and set up a new call */
321 call = b->call_backlog[call_tail];
322 b->call_backlog[call_tail] = NULL;
323 smp_store_release(&b->call_backlog_tail,
324 (call_tail + 1) & (RXRPC_BACKLOG_MAX - 1));
325
326 rxrpc_see_call(call);
327 call->conn = conn;
328 call->security = conn->security;
329 call->peer = rxrpc_get_peer(conn->params.peer);
330 call->cong_cwnd = call->peer->cong_cwnd;
331 return call;
332 }
333
334 /*
335 * Set up a new incoming call. Called in BH context with the RCU read lock
336 * held.
337 *
338 * If this is for a kernel service, when we allocate the call, it will have
339 * three refs on it: (1) the kernel service, (2) the user_call_ID tree, (3) the
340 * retainer ref obtained from the backlog buffer. Prealloc calls for userspace
341 * services only have the ref from the backlog buffer. We want to pass this
342 * ref to non-BH context to dispose of.
343 *
344 * If we want to report an error, we mark the skb with the packet type and
345 * abort code and return NULL.
346 *
347 * The call is returned with the user access mutex held.
348 */
rxrpc_new_incoming_call(struct rxrpc_local * local,struct rxrpc_sock * rx,struct sk_buff * skb)349 struct rxrpc_call *rxrpc_new_incoming_call(struct rxrpc_local *local,
350 struct rxrpc_sock *rx,
351 struct sk_buff *skb)
352 {
353 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
354 const struct rxrpc_security *sec = NULL;
355 struct rxrpc_connection *conn;
356 struct rxrpc_peer *peer = NULL;
357 struct rxrpc_call *call = NULL;
358 struct key *key = NULL;
359
360 _enter("");
361
362 spin_lock(&rx->incoming_lock);
363 if (rx->sk.sk_state == RXRPC_SERVER_LISTEN_DISABLED ||
364 rx->sk.sk_state == RXRPC_CLOSE) {
365 trace_rxrpc_abort(0, "CLS", sp->hdr.cid, sp->hdr.callNumber,
366 sp->hdr.seq, RX_INVALID_OPERATION, ESHUTDOWN);
367 skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
368 skb->priority = RX_INVALID_OPERATION;
369 goto no_call;
370 }
371
372 /* The peer, connection and call may all have sprung into existence due
373 * to a duplicate packet being handled on another CPU in parallel, so
374 * we have to recheck the routing. However, we're now holding
375 * rx->incoming_lock, so the values should remain stable.
376 */
377 conn = rxrpc_find_connection_rcu(local, skb, &peer);
378
379 if (!conn && !rxrpc_look_up_server_security(local, rx, &sec, &key, skb))
380 goto no_call;
381
382 call = rxrpc_alloc_incoming_call(rx, local, peer, conn, sec, key, skb);
383 key_put(key);
384 if (!call) {
385 skb->mark = RXRPC_SKB_MARK_REJECT_BUSY;
386 goto no_call;
387 }
388
389 trace_rxrpc_receive(call, rxrpc_receive_incoming,
390 sp->hdr.serial, sp->hdr.seq);
391
392 /* Make the call live. */
393 rxrpc_incoming_call(rx, call, skb);
394 conn = call->conn;
395
396 if (rx->notify_new_call)
397 rx->notify_new_call(&rx->sk, call, call->user_call_ID);
398 else
399 sk_acceptq_added(&rx->sk);
400
401 spin_lock(&conn->state_lock);
402 switch (conn->state) {
403 case RXRPC_CONN_SERVICE_UNSECURED:
404 conn->state = RXRPC_CONN_SERVICE_CHALLENGING;
405 set_bit(RXRPC_CONN_EV_CHALLENGE, &call->conn->events);
406 rxrpc_queue_conn(call->conn);
407 break;
408
409 case RXRPC_CONN_SERVICE:
410 write_lock(&call->state_lock);
411 if (call->state < RXRPC_CALL_COMPLETE) {
412 if (rx->discard_new_call)
413 call->state = RXRPC_CALL_SERVER_RECV_REQUEST;
414 else
415 call->state = RXRPC_CALL_SERVER_ACCEPTING;
416 }
417 write_unlock(&call->state_lock);
418 break;
419
420 case RXRPC_CONN_REMOTELY_ABORTED:
421 rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
422 conn->abort_code, conn->error);
423 break;
424 case RXRPC_CONN_LOCALLY_ABORTED:
425 rxrpc_abort_call("CON", call, sp->hdr.seq,
426 conn->abort_code, conn->error);
427 break;
428 default:
429 BUG();
430 }
431 spin_unlock(&conn->state_lock);
432 spin_unlock(&rx->incoming_lock);
433
434 rxrpc_send_ping(call, skb);
435
436 if (call->state == RXRPC_CALL_SERVER_ACCEPTING)
437 rxrpc_notify_socket(call);
438
439 /* We have to discard the prealloc queue's ref here and rely on a
440 * combination of the RCU read lock and refs held either by the socket
441 * (recvmsg queue, to-be-accepted queue or user ID tree) or the kernel
442 * service to prevent the call from being deallocated too early.
443 */
444 rxrpc_put_call(call, rxrpc_call_put);
445
446 _leave(" = %p{%d}", call, call->debug_id);
447 return call;
448
449 no_call:
450 spin_unlock(&rx->incoming_lock);
451 _leave(" = NULL [%u]", skb->mark);
452 return NULL;
453 }
454
455 /*
456 * handle acceptance of a call by userspace
457 * - assign the user call ID to the call at the front of the queue
458 * - called with the socket locked.
459 */
rxrpc_accept_call(struct rxrpc_sock * rx,unsigned long user_call_ID,rxrpc_notify_rx_t notify_rx)460 struct rxrpc_call *rxrpc_accept_call(struct rxrpc_sock *rx,
461 unsigned long user_call_ID,
462 rxrpc_notify_rx_t notify_rx)
463 __releases(&rx->sk.sk_lock.slock)
464 __acquires(call->user_mutex)
465 {
466 struct rxrpc_call *call;
467 struct rb_node *parent, **pp;
468 int ret;
469
470 _enter(",%lx", user_call_ID);
471
472 ASSERT(!irqs_disabled());
473
474 write_lock(&rx->call_lock);
475
476 if (list_empty(&rx->to_be_accepted)) {
477 write_unlock(&rx->call_lock);
478 release_sock(&rx->sk);
479 kleave(" = -ENODATA [empty]");
480 return ERR_PTR(-ENODATA);
481 }
482
483 /* check the user ID isn't already in use */
484 pp = &rx->calls.rb_node;
485 parent = NULL;
486 while (*pp) {
487 parent = *pp;
488 call = rb_entry(parent, struct rxrpc_call, sock_node);
489
490 if (user_call_ID < call->user_call_ID)
491 pp = &(*pp)->rb_left;
492 else if (user_call_ID > call->user_call_ID)
493 pp = &(*pp)->rb_right;
494 else
495 goto id_in_use;
496 }
497
498 /* Dequeue the first call and check it's still valid. We gain
499 * responsibility for the queue's reference.
500 */
501 call = list_entry(rx->to_be_accepted.next,
502 struct rxrpc_call, accept_link);
503 write_unlock(&rx->call_lock);
504
505 /* We need to gain the mutex from the interrupt handler without
506 * upsetting lockdep, so we have to release it there and take it here.
507 * We are, however, still holding the socket lock, so other accepts
508 * must wait for us and no one can add the user ID behind our backs.
509 */
510 if (mutex_lock_interruptible(&call->user_mutex) < 0) {
511 release_sock(&rx->sk);
512 kleave(" = -ERESTARTSYS");
513 return ERR_PTR(-ERESTARTSYS);
514 }
515
516 write_lock(&rx->call_lock);
517 list_del_init(&call->accept_link);
518 sk_acceptq_removed(&rx->sk);
519 rxrpc_see_call(call);
520
521 /* Find the user ID insertion point. */
522 pp = &rx->calls.rb_node;
523 parent = NULL;
524 while (*pp) {
525 parent = *pp;
526 call = rb_entry(parent, struct rxrpc_call, sock_node);
527
528 if (user_call_ID < call->user_call_ID)
529 pp = &(*pp)->rb_left;
530 else if (user_call_ID > call->user_call_ID)
531 pp = &(*pp)->rb_right;
532 else
533 BUG();
534 }
535
536 write_lock_bh(&call->state_lock);
537 switch (call->state) {
538 case RXRPC_CALL_SERVER_ACCEPTING:
539 call->state = RXRPC_CALL_SERVER_RECV_REQUEST;
540 break;
541 case RXRPC_CALL_COMPLETE:
542 ret = call->error;
543 goto out_release;
544 default:
545 BUG();
546 }
547
548 /* formalise the acceptance */
549 call->notify_rx = notify_rx;
550 call->user_call_ID = user_call_ID;
551 rxrpc_get_call(call, rxrpc_call_got_userid);
552 rb_link_node(&call->sock_node, parent, pp);
553 rb_insert_color(&call->sock_node, &rx->calls);
554 if (test_and_set_bit(RXRPC_CALL_HAS_USERID, &call->flags))
555 BUG();
556
557 write_unlock_bh(&call->state_lock);
558 write_unlock(&rx->call_lock);
559 rxrpc_notify_socket(call);
560 rxrpc_service_prealloc(rx, GFP_KERNEL);
561 release_sock(&rx->sk);
562 _leave(" = %p{%d}", call, call->debug_id);
563 return call;
564
565 out_release:
566 _debug("release %p", call);
567 write_unlock_bh(&call->state_lock);
568 write_unlock(&rx->call_lock);
569 rxrpc_release_call(rx, call);
570 rxrpc_put_call(call, rxrpc_call_put);
571 goto out;
572
573 id_in_use:
574 ret = -EBADSLT;
575 write_unlock(&rx->call_lock);
576 out:
577 rxrpc_service_prealloc(rx, GFP_KERNEL);
578 release_sock(&rx->sk);
579 _leave(" = %d", ret);
580 return ERR_PTR(ret);
581 }
582
583 /*
584 * Handle rejection of a call by userspace
585 * - reject the call at the front of the queue
586 */
rxrpc_reject_call(struct rxrpc_sock * rx)587 int rxrpc_reject_call(struct rxrpc_sock *rx)
588 {
589 struct rxrpc_call *call;
590 bool abort = false;
591 int ret;
592
593 _enter("");
594
595 ASSERT(!irqs_disabled());
596
597 write_lock(&rx->call_lock);
598
599 if (list_empty(&rx->to_be_accepted)) {
600 write_unlock(&rx->call_lock);
601 return -ENODATA;
602 }
603
604 /* Dequeue the first call and check it's still valid. We gain
605 * responsibility for the queue's reference.
606 */
607 call = list_entry(rx->to_be_accepted.next,
608 struct rxrpc_call, accept_link);
609 list_del_init(&call->accept_link);
610 sk_acceptq_removed(&rx->sk);
611 rxrpc_see_call(call);
612
613 write_lock_bh(&call->state_lock);
614 switch (call->state) {
615 case RXRPC_CALL_SERVER_ACCEPTING:
616 __rxrpc_abort_call("REJ", call, 1, RX_USER_ABORT, -ECONNABORTED);
617 abort = true;
618 /* fall through */
619 case RXRPC_CALL_COMPLETE:
620 ret = call->error;
621 goto out_discard;
622 default:
623 BUG();
624 }
625
626 out_discard:
627 write_unlock_bh(&call->state_lock);
628 write_unlock(&rx->call_lock);
629 if (abort) {
630 rxrpc_send_abort_packet(call);
631 rxrpc_release_call(rx, call);
632 rxrpc_put_call(call, rxrpc_call_put);
633 }
634 rxrpc_service_prealloc(rx, GFP_KERNEL);
635 _leave(" = %d", ret);
636 return ret;
637 }
638
639 /*
640 * rxrpc_kernel_charge_accept - Charge up socket with preallocated calls
641 * @sock: The socket on which to preallocate
642 * @notify_rx: Event notification function for the call
643 * @user_attach_call: Func to attach call to user_call_ID
644 * @user_call_ID: The tag to attach to the preallocated call
645 * @gfp: The allocation conditions.
646 * @debug_id: The tracing debug ID.
647 *
648 * Charge up the socket with preallocated calls, each with a user ID. A
649 * function should be provided to effect the attachment from the user's side.
650 * The user is given a ref to hold on the call.
651 *
652 * Note that the call may be come connected before this function returns.
653 */
rxrpc_kernel_charge_accept(struct socket * sock,rxrpc_notify_rx_t notify_rx,rxrpc_user_attach_call_t user_attach_call,unsigned long user_call_ID,gfp_t gfp,unsigned int debug_id)654 int rxrpc_kernel_charge_accept(struct socket *sock,
655 rxrpc_notify_rx_t notify_rx,
656 rxrpc_user_attach_call_t user_attach_call,
657 unsigned long user_call_ID, gfp_t gfp,
658 unsigned int debug_id)
659 {
660 struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
661 struct rxrpc_backlog *b = rx->backlog;
662
663 if (sock->sk->sk_state == RXRPC_CLOSE)
664 return -ESHUTDOWN;
665
666 return rxrpc_service_prealloc_one(rx, b, notify_rx,
667 user_attach_call, user_call_ID,
668 gfp, debug_id);
669 }
670 EXPORT_SYMBOL(rxrpc_kernel_charge_accept);
671