1 /* RxRPC individual remote procedure call handling
3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 #include <linux/slab.h>
15 #include <linux/module.h>
16 #include <linux/circ_buf.h>
17 #include <linux/spinlock_types.h>
19 #include <net/af_rxrpc.h>
20 #include "ar-internal.h"
22 const char *const rxrpc_call_states[NR__RXRPC_CALL_STATES] = {
23 [RXRPC_CALL_UNINITIALISED] = "Uninit ",
24 [RXRPC_CALL_CLIENT_AWAIT_CONN] = "ClWtConn",
25 [RXRPC_CALL_CLIENT_SEND_REQUEST] = "ClSndReq",
26 [RXRPC_CALL_CLIENT_AWAIT_REPLY] = "ClAwtRpl",
27 [RXRPC_CALL_CLIENT_RECV_REPLY] = "ClRcvRpl",
28 [RXRPC_CALL_SERVER_PREALLOC] = "SvPrealc",
29 [RXRPC_CALL_SERVER_SECURING] = "SvSecure",
30 [RXRPC_CALL_SERVER_ACCEPTING] = "SvAccept",
31 [RXRPC_CALL_SERVER_RECV_REQUEST] = "SvRcvReq",
32 [RXRPC_CALL_SERVER_ACK_REQUEST] = "SvAckReq",
33 [RXRPC_CALL_SERVER_SEND_REPLY] = "SvSndRpl",
34 [RXRPC_CALL_SERVER_AWAIT_ACK] = "SvAwtACK",
35 [RXRPC_CALL_COMPLETE] = "Complete",
38 const char *const rxrpc_call_completions[NR__RXRPC_CALL_COMPLETIONS] = {
39 [RXRPC_CALL_SUCCEEDED] = "Complete",
40 [RXRPC_CALL_REMOTELY_ABORTED] = "RmtAbort",
41 [RXRPC_CALL_LOCALLY_ABORTED] = "LocAbort",
42 [RXRPC_CALL_LOCAL_ERROR] = "LocError",
43 [RXRPC_CALL_NETWORK_ERROR] = "NetError",
46 struct kmem_cache *rxrpc_call_jar;
48 static void rxrpc_call_timer_expired(struct timer_list *t)
50 struct rxrpc_call *call = from_timer(call, t, timer);
52 _enter("%d", call->debug_id);
54 if (call->state < RXRPC_CALL_COMPLETE) {
55 trace_rxrpc_timer(call, rxrpc_timer_expired, jiffies);
56 rxrpc_queue_call(call);
60 static struct lock_class_key rxrpc_call_user_mutex_lock_class_key;
63 * find an extant server call
64 * - called in process context with IRQs enabled
66 struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx,
67 unsigned long user_call_ID)
69 struct rxrpc_call *call;
72 _enter("%p,%lx", rx, user_call_ID);
74 read_lock(&rx->call_lock);
76 p = rx->calls.rb_node;
78 call = rb_entry(p, struct rxrpc_call, sock_node);
80 if (user_call_ID < call->user_call_ID)
82 else if (user_call_ID > call->user_call_ID)
85 goto found_extant_call;
88 read_unlock(&rx->call_lock);
93 rxrpc_get_call(call, rxrpc_call_got);
94 read_unlock(&rx->call_lock);
95 _leave(" = %p [%d]", call, atomic_read(&call->usage));
100 * allocate a new call
102 struct rxrpc_call *rxrpc_alloc_call(struct rxrpc_sock *rx, gfp_t gfp,
103 unsigned int debug_id)
105 struct rxrpc_call *call;
106 struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk));
108 call = kmem_cache_zalloc(rxrpc_call_jar, gfp);
112 call->rxtx_buffer = kcalloc(RXRPC_RXTX_BUFF_SIZE,
113 sizeof(struct sk_buff *),
115 if (!call->rxtx_buffer)
118 call->rxtx_annotations = kcalloc(RXRPC_RXTX_BUFF_SIZE, sizeof(u8), gfp);
119 if (!call->rxtx_annotations)
122 mutex_init(&call->user_mutex);
124 /* Prevent lockdep reporting a deadlock false positive between the afs
125 * filesystem and sys_sendmsg() via the mmap sem.
127 if (rx->sk.sk_kern_sock)
128 lockdep_set_class(&call->user_mutex,
129 &rxrpc_call_user_mutex_lock_class_key);
131 timer_setup(&call->timer, rxrpc_call_timer_expired, 0);
132 INIT_WORK(&call->processor, &rxrpc_process_call);
133 INIT_LIST_HEAD(&call->link);
134 INIT_LIST_HEAD(&call->chan_wait_link);
135 INIT_LIST_HEAD(&call->accept_link);
136 INIT_LIST_HEAD(&call->recvmsg_link);
137 INIT_LIST_HEAD(&call->sock_link);
138 init_waitqueue_head(&call->waitq);
139 spin_lock_init(&call->lock);
140 spin_lock_init(&call->notify_lock);
141 spin_lock_init(&call->input_lock);
142 rwlock_init(&call->state_lock);
143 atomic_set(&call->usage, 1);
144 call->debug_id = debug_id;
145 call->tx_total_len = -1;
146 call->next_rx_timo = 20 * HZ;
147 call->next_req_timo = 1 * HZ;
149 memset(&call->sock_node, 0xed, sizeof(call->sock_node));
151 /* Leave space in the ring to handle a maxed-out jumbo packet */
152 call->rx_winsize = rxrpc_rx_window_size;
153 call->tx_winsize = 16;
154 call->rx_expect_next = 1;
157 call->cong_ssthresh = RXRPC_RXTX_BUFF_SIZE - 1;
160 atomic_inc(&rxnet->nr_calls);
164 kfree(call->rxtx_buffer);
166 kmem_cache_free(rxrpc_call_jar, call);
171 * Allocate a new client call.
173 static struct rxrpc_call *rxrpc_alloc_client_call(struct rxrpc_sock *rx,
174 struct sockaddr_rxrpc *srx,
176 unsigned int debug_id)
178 struct rxrpc_call *call;
183 call = rxrpc_alloc_call(rx, gfp, debug_id);
185 return ERR_PTR(-ENOMEM);
186 call->state = RXRPC_CALL_CLIENT_AWAIT_CONN;
187 call->service_id = srx->srx_service;
188 call->tx_phase = true;
189 now = ktime_get_real();
190 call->acks_latest_ts = now;
191 call->cong_tstamp = now;
193 _leave(" = %p", call);
198 * Initiate the call ack/resend/expiry timer.
200 static void rxrpc_start_call_timer(struct rxrpc_call *call)
202 unsigned long now = jiffies;
203 unsigned long j = now + MAX_JIFFY_OFFSET;
206 call->ack_lost_at = j;
209 call->expect_rx_by = j;
210 call->expect_req_by = j;
211 call->expect_term_by = j;
212 call->timer.expires = now;
216 * Set up a call for the given parameters.
217 * - Called with the socket lock held, which it must release.
218 * - If it returns a call, the call's lock will need releasing by the caller.
220 struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
221 struct rxrpc_conn_parameters *cp,
222 struct sockaddr_rxrpc *srx,
223 struct rxrpc_call_params *p,
225 unsigned int debug_id)
226 __releases(&rx->sk.sk_lock.slock)
227 __acquires(&call->user_mutex)
229 struct rxrpc_call *call, *xcall;
230 struct rxrpc_net *rxnet;
231 struct rb_node *parent, **pp;
232 const void *here = __builtin_return_address(0);
235 _enter("%p,%lx", rx, p->user_call_ID);
237 call = rxrpc_alloc_client_call(rx, srx, gfp, debug_id);
239 release_sock(&rx->sk);
240 _leave(" = %ld", PTR_ERR(call));
244 call->tx_total_len = p->tx_total_len;
245 trace_rxrpc_call(call, rxrpc_call_new_client, atomic_read(&call->usage),
246 here, (const void *)p->user_call_ID);
248 /* We need to protect a partially set up call against the user as we
249 * will be acting outside the socket lock.
251 mutex_lock(&call->user_mutex);
253 /* Publish the call, even though it is incompletely set up as yet */
254 write_lock(&rx->call_lock);
256 pp = &rx->calls.rb_node;
260 xcall = rb_entry(parent, struct rxrpc_call, sock_node);
262 if (p->user_call_ID < xcall->user_call_ID)
263 pp = &(*pp)->rb_left;
264 else if (p->user_call_ID > xcall->user_call_ID)
265 pp = &(*pp)->rb_right;
267 goto error_dup_user_ID;
270 rcu_assign_pointer(call->socket, rx);
271 call->user_call_ID = p->user_call_ID;
272 __set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
273 rxrpc_get_call(call, rxrpc_call_got_userid);
274 rb_link_node(&call->sock_node, parent, pp);
275 rb_insert_color(&call->sock_node, &rx->calls);
276 list_add(&call->sock_link, &rx->sock_calls);
278 write_unlock(&rx->call_lock);
281 write_lock(&rxnet->call_lock);
282 list_add_tail(&call->link, &rxnet->calls);
283 write_unlock(&rxnet->call_lock);
285 /* From this point on, the call is protected by its own lock. */
286 release_sock(&rx->sk);
288 /* Set up or get a connection record and set the protocol parameters,
289 * including channel number and call ID.
291 ret = rxrpc_connect_call(rx, call, cp, srx, gfp);
293 goto error_attached_to_socket;
295 trace_rxrpc_call(call, rxrpc_call_connected, atomic_read(&call->usage),
298 rxrpc_start_call_timer(call);
300 _net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id);
302 _leave(" = %p [new]", call);
305 /* We unexpectedly found the user ID in the list after taking
306 * the call_lock. This shouldn't happen unless the user races
307 * with itself and tries to add the same user ID twice at the
308 * same time in different threads.
311 write_unlock(&rx->call_lock);
312 release_sock(&rx->sk);
313 __rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
314 RX_CALL_DEAD, -EEXIST);
315 trace_rxrpc_call(call, rxrpc_call_error, atomic_read(&call->usage),
316 here, ERR_PTR(-EEXIST));
317 rxrpc_release_call(rx, call);
318 mutex_unlock(&call->user_mutex);
319 rxrpc_put_call(call, rxrpc_call_put);
320 _leave(" = -EEXIST");
321 return ERR_PTR(-EEXIST);
323 /* We got an error, but the call is attached to the socket and is in
324 * need of release. However, we might now race with recvmsg() when
325 * completing the call queues it. Return 0 from sys_sendmsg() and
326 * leave the error to recvmsg() to deal with.
328 error_attached_to_socket:
329 trace_rxrpc_call(call, rxrpc_call_error, atomic_read(&call->usage),
331 set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
332 __rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
334 _leave(" = c=%08x [err]", call->debug_id);
339 * Retry a call to a new address. It is expected that the Tx queue of the call
340 * will contain data previously packaged for an old call.
342 int rxrpc_retry_client_call(struct rxrpc_sock *rx,
343 struct rxrpc_call *call,
344 struct rxrpc_conn_parameters *cp,
345 struct sockaddr_rxrpc *srx,
348 const void *here = __builtin_return_address(0);
351 /* Set up or get a connection record and set the protocol parameters,
352 * including channel number and call ID.
354 ret = rxrpc_connect_call(rx, call, cp, srx, gfp);
358 trace_rxrpc_call(call, rxrpc_call_connected, atomic_read(&call->usage),
361 rxrpc_start_call_timer(call);
363 _net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id);
365 if (!test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
366 rxrpc_queue_call(call);
372 rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
374 trace_rxrpc_call(call, rxrpc_call_error, atomic_read(&call->usage),
376 _leave(" = %d", ret);
381 * Set up an incoming call. call->conn points to the connection.
382 * This is called in BH context and isn't allowed to fail.
384 void rxrpc_incoming_call(struct rxrpc_sock *rx,
385 struct rxrpc_call *call,
388 struct rxrpc_connection *conn = call->conn;
389 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
392 _enter(",%d", call->conn->debug_id);
394 rcu_assign_pointer(call->socket, rx);
395 call->call_id = sp->hdr.callNumber;
396 call->service_id = sp->hdr.serviceId;
397 call->cid = sp->hdr.cid;
398 call->state = RXRPC_CALL_SERVER_ACCEPTING;
399 if (sp->hdr.securityIndex > 0)
400 call->state = RXRPC_CALL_SERVER_SECURING;
401 call->cong_tstamp = skb->tstamp;
403 /* Set the channel for this call. We don't get channel_lock as we're
404 * only defending against the data_ready handler (which we're called
405 * from) and the RESPONSE packet parser (which is only really
406 * interested in call_counter and can cope with a disagreement with the
409 chan = sp->hdr.cid & RXRPC_CHANNELMASK;
410 conn->channels[chan].call_counter = call->call_id;
411 conn->channels[chan].call_id = call->call_id;
412 rcu_assign_pointer(conn->channels[chan].call, call);
414 spin_lock(&conn->params.peer->lock);
415 hlist_add_head_rcu(&call->error_link, &conn->params.peer->error_targets);
416 spin_unlock(&conn->params.peer->lock);
418 _net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id);
420 rxrpc_start_call_timer(call);
425 * Queue a call's work processor, getting a ref to pass to the work queue.
427 bool rxrpc_queue_call(struct rxrpc_call *call)
429 const void *here = __builtin_return_address(0);
430 int n = atomic_fetch_add_unless(&call->usage, 1, 0);
433 if (rxrpc_queue_work(&call->processor))
434 trace_rxrpc_call(call, rxrpc_call_queued, n + 1, here, NULL);
436 rxrpc_put_call(call, rxrpc_call_put_noqueue);
441 * Queue a call's work processor, passing the callers ref to the work queue.
443 bool __rxrpc_queue_call(struct rxrpc_call *call)
445 const void *here = __builtin_return_address(0);
446 int n = atomic_read(&call->usage);
448 if (rxrpc_queue_work(&call->processor))
449 trace_rxrpc_call(call, rxrpc_call_queued_ref, n, here, NULL);
451 rxrpc_put_call(call, rxrpc_call_put_noqueue);
456 * Note the re-emergence of a call.
458 void rxrpc_see_call(struct rxrpc_call *call)
460 const void *here = __builtin_return_address(0);
462 int n = atomic_read(&call->usage);
464 trace_rxrpc_call(call, rxrpc_call_seen, n, here, NULL);
469 * Note the addition of a ref on a call.
471 void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
473 const void *here = __builtin_return_address(0);
474 int n = atomic_inc_return(&call->usage);
476 trace_rxrpc_call(call, op, n, here, NULL);
480 * Detach a call from its owning socket.
482 void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
484 const void *here = __builtin_return_address(0);
485 struct rxrpc_connection *conn = call->conn;
489 _enter("{%d,%d}", call->debug_id, atomic_read(&call->usage));
491 trace_rxrpc_call(call, rxrpc_call_release, atomic_read(&call->usage),
492 here, (const void *)call->flags);
494 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
496 spin_lock_bh(&call->lock);
497 if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
499 spin_unlock_bh(&call->lock);
501 del_timer_sync(&call->timer);
503 /* Make sure we don't get any more notifications */
504 write_lock_bh(&rx->recvmsg_lock);
506 if (!list_empty(&call->recvmsg_link)) {
507 _debug("unlinking once-pending call %p { e=%lx f=%lx }",
508 call, call->events, call->flags);
509 list_del(&call->recvmsg_link);
513 /* list_empty() must return false in rxrpc_notify_socket() */
514 call->recvmsg_link.next = NULL;
515 call->recvmsg_link.prev = NULL;
517 write_unlock_bh(&rx->recvmsg_lock);
519 rxrpc_put_call(call, rxrpc_call_put);
521 write_lock(&rx->call_lock);
523 if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
524 rb_erase(&call->sock_node, &rx->calls);
525 memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
526 rxrpc_put_call(call, rxrpc_call_put_userid);
529 list_del(&call->sock_link);
530 write_unlock(&rx->call_lock);
532 _debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
534 if (conn && !test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
535 rxrpc_disconnect_call(call);
537 for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) {
538 rxrpc_free_skb(call->rxtx_buffer[i],
539 (call->tx_phase ? rxrpc_skb_tx_cleaned :
540 rxrpc_skb_rx_cleaned));
541 call->rxtx_buffer[i] = NULL;
548 * Prepare a kernel service call for retry.
550 int rxrpc_prepare_call_for_retry(struct rxrpc_sock *rx, struct rxrpc_call *call)
552 const void *here = __builtin_return_address(0);
556 _enter("{%d,%d}", call->debug_id, atomic_read(&call->usage));
558 trace_rxrpc_call(call, rxrpc_call_release, atomic_read(&call->usage),
559 here, (const void *)call->flags);
561 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
562 ASSERTCMP(call->completion, !=, RXRPC_CALL_REMOTELY_ABORTED);
563 ASSERTCMP(call->completion, !=, RXRPC_CALL_LOCALLY_ABORTED);
564 ASSERT(list_empty(&call->recvmsg_link));
566 del_timer_sync(&call->timer);
568 _debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, call->conn);
571 rxrpc_disconnect_call(call);
573 if (rxrpc_is_service_call(call) ||
575 call->tx_hard_ack != 0 ||
576 call->rx_hard_ack != 0 ||
580 call->state = RXRPC_CALL_UNINITIALISED;
581 call->completion = RXRPC_CALL_SUCCEEDED;
585 call->cong_extra = 0;
586 call->cong_ssthresh = 0;
588 call->cong_dup_acks = 0;
589 call->cong_cumul_acks = 0;
590 call->acks_lowest_nak = 0;
592 for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) {
593 last |= call->rxtx_annotations[i];
594 call->rxtx_annotations[i] &= RXRPC_TX_ANNO_LAST;
595 call->rxtx_annotations[i] |= RXRPC_TX_ANNO_RETRANS;
603 * release all the calls associated with a socket
605 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
607 struct rxrpc_call *call;
611 while (!list_empty(&rx->to_be_accepted)) {
612 call = list_entry(rx->to_be_accepted.next,
613 struct rxrpc_call, accept_link);
614 list_del(&call->accept_link);
615 rxrpc_abort_call("SKR", call, 0, RX_CALL_DEAD, -ECONNRESET);
616 rxrpc_put_call(call, rxrpc_call_put);
619 while (!list_empty(&rx->sock_calls)) {
620 call = list_entry(rx->sock_calls.next,
621 struct rxrpc_call, sock_link);
622 rxrpc_get_call(call, rxrpc_call_got);
623 rxrpc_abort_call("SKT", call, 0, RX_CALL_DEAD, -ECONNRESET);
624 rxrpc_send_abort_packet(call);
625 rxrpc_release_call(rx, call);
626 rxrpc_put_call(call, rxrpc_call_put);
635 void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
637 struct rxrpc_net *rxnet = call->rxnet;
638 const void *here = __builtin_return_address(0);
641 ASSERT(call != NULL);
643 n = atomic_dec_return(&call->usage);
644 trace_rxrpc_call(call, op, n, here, NULL);
647 _debug("call %d dead", call->debug_id);
648 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
650 if (!list_empty(&call->link)) {
651 write_lock(&rxnet->call_lock);
652 list_del_init(&call->link);
653 write_unlock(&rxnet->call_lock);
656 rxrpc_cleanup_call(call);
661 * Final call destruction - but must be done in process context.
663 static void rxrpc_destroy_call(struct work_struct *work)
665 struct rxrpc_call *call = container_of(work, struct rxrpc_call, processor);
666 struct rxrpc_net *rxnet = call->rxnet;
668 rxrpc_put_connection(call->conn);
669 rxrpc_put_peer(call->peer);
670 kfree(call->rxtx_buffer);
671 kfree(call->rxtx_annotations);
672 kmem_cache_free(rxrpc_call_jar, call);
673 if (atomic_dec_and_test(&rxnet->nr_calls))
674 wake_up_var(&rxnet->nr_calls);
678 * Final call destruction under RCU.
680 static void rxrpc_rcu_destroy_call(struct rcu_head *rcu)
682 struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
685 INIT_WORK(&call->processor, rxrpc_destroy_call);
686 if (!rxrpc_queue_work(&call->processor))
689 rxrpc_destroy_call(&call->processor);
696 void rxrpc_cleanup_call(struct rxrpc_call *call)
700 _net("DESTROY CALL %d", call->debug_id);
702 memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
704 del_timer_sync(&call->timer);
706 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
707 ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
709 /* Clean up the Rx/Tx buffer */
710 for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++)
711 rxrpc_free_skb(call->rxtx_buffer[i],
712 (call->tx_phase ? rxrpc_skb_tx_cleaned :
713 rxrpc_skb_rx_cleaned));
715 rxrpc_free_skb(call->tx_pending, rxrpc_skb_tx_cleaned);
717 call_rcu(&call->rcu, rxrpc_rcu_destroy_call);
721 * Make sure that all calls are gone from a network namespace. To reach this
722 * point, any open UDP sockets in that namespace must have been closed, so any
723 * outstanding calls cannot be doing I/O.
725 void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet)
727 struct rxrpc_call *call;
731 if (!list_empty(&rxnet->calls)) {
732 write_lock(&rxnet->call_lock);
734 while (!list_empty(&rxnet->calls)) {
735 call = list_entry(rxnet->calls.next,
736 struct rxrpc_call, link);
737 _debug("Zapping call %p", call);
739 rxrpc_see_call(call);
740 list_del_init(&call->link);
742 pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
743 call, atomic_read(&call->usage),
744 rxrpc_call_states[call->state],
745 call->flags, call->events);
747 write_unlock(&rxnet->call_lock);
749 write_lock(&rxnet->call_lock);
752 write_unlock(&rxnet->call_lock);
755 atomic_dec(&rxnet->nr_calls);
756 wait_var_event(&rxnet->nr_calls, !atomic_read(&rxnet->nr_calls));