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(unsigned long _call)
50 struct rxrpc_call *call = (struct rxrpc_call *)_call;
52 _enter("%d", call->debug_id);
54 if (call->state < RXRPC_CALL_COMPLETE)
55 rxrpc_set_timer(call, rxrpc_timer_expired, ktime_get_real());
58 static struct lock_class_key rxrpc_call_user_mutex_lock_class_key;
61 * find an extant server call
62 * - called in process context with IRQs enabled
64 struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx,
65 unsigned long user_call_ID)
67 struct rxrpc_call *call;
70 _enter("%p,%lx", rx, user_call_ID);
72 read_lock(&rx->call_lock);
74 p = rx->calls.rb_node;
76 call = rb_entry(p, struct rxrpc_call, sock_node);
78 if (user_call_ID < call->user_call_ID)
80 else if (user_call_ID > call->user_call_ID)
83 goto found_extant_call;
86 read_unlock(&rx->call_lock);
91 rxrpc_get_call(call, rxrpc_call_got);
92 read_unlock(&rx->call_lock);
93 _leave(" = %p [%d]", call, atomic_read(&call->usage));
100 struct rxrpc_call *rxrpc_alloc_call(struct rxrpc_sock *rx, gfp_t gfp)
102 struct rxrpc_call *call;
104 call = kmem_cache_zalloc(rxrpc_call_jar, gfp);
108 call->rxtx_buffer = kcalloc(RXRPC_RXTX_BUFF_SIZE,
109 sizeof(struct sk_buff *),
111 if (!call->rxtx_buffer)
114 call->rxtx_annotations = kcalloc(RXRPC_RXTX_BUFF_SIZE, sizeof(u8), gfp);
115 if (!call->rxtx_annotations)
118 mutex_init(&call->user_mutex);
120 /* Prevent lockdep reporting a deadlock false positive between the afs
121 * filesystem and sys_sendmsg() via the mmap sem.
123 if (rx->sk.sk_kern_sock)
124 lockdep_set_class(&call->user_mutex,
125 &rxrpc_call_user_mutex_lock_class_key);
127 setup_timer(&call->timer, rxrpc_call_timer_expired,
128 (unsigned long)call);
129 INIT_WORK(&call->processor, &rxrpc_process_call);
130 INIT_LIST_HEAD(&call->link);
131 INIT_LIST_HEAD(&call->chan_wait_link);
132 INIT_LIST_HEAD(&call->accept_link);
133 INIT_LIST_HEAD(&call->recvmsg_link);
134 INIT_LIST_HEAD(&call->sock_link);
135 init_waitqueue_head(&call->waitq);
136 spin_lock_init(&call->lock);
137 rwlock_init(&call->state_lock);
138 atomic_set(&call->usage, 1);
139 call->debug_id = atomic_inc_return(&rxrpc_debug_id);
140 call->tx_total_len = -1;
142 memset(&call->sock_node, 0xed, sizeof(call->sock_node));
144 /* Leave space in the ring to handle a maxed-out jumbo packet */
145 call->rx_winsize = rxrpc_rx_window_size;
146 call->tx_winsize = 16;
147 call->rx_expect_next = 1;
150 call->cong_ssthresh = RXRPC_RXTX_BUFF_SIZE - 1;
154 kfree(call->rxtx_buffer);
156 kmem_cache_free(rxrpc_call_jar, call);
161 * Allocate a new client call.
163 static struct rxrpc_call *rxrpc_alloc_client_call(struct rxrpc_sock *rx,
164 struct sockaddr_rxrpc *srx,
167 struct rxrpc_call *call;
172 call = rxrpc_alloc_call(rx, gfp);
174 return ERR_PTR(-ENOMEM);
175 call->state = RXRPC_CALL_CLIENT_AWAIT_CONN;
176 call->service_id = srx->srx_service;
177 call->tx_phase = true;
178 now = ktime_get_real();
179 call->acks_latest_ts = now;
180 call->cong_tstamp = now;
182 _leave(" = %p", call);
187 * Initiate the call ack/resend/expiry timer.
189 static void rxrpc_start_call_timer(struct rxrpc_call *call)
191 ktime_t now = ktime_get_real(), expire_at;
193 expire_at = ktime_add_ms(now, rxrpc_max_call_lifetime);
194 call->expire_at = expire_at;
195 call->ack_at = expire_at;
196 call->ping_at = expire_at;
197 call->resend_at = expire_at;
198 call->timer.expires = jiffies + LONG_MAX / 2;
199 rxrpc_set_timer(call, rxrpc_timer_begin, now);
203 * Set up a call for the given parameters.
204 * - Called with the socket lock held, which it must release.
205 * - If it returns a call, the call's lock will need releasing by the caller.
207 struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
208 struct rxrpc_conn_parameters *cp,
209 struct sockaddr_rxrpc *srx,
210 unsigned long user_call_ID,
213 __releases(&rx->sk.sk_lock.slock)
215 struct rxrpc_call *call, *xcall;
216 struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk));
217 struct rb_node *parent, **pp;
218 const void *here = __builtin_return_address(0);
221 _enter("%p,%lx", rx, user_call_ID);
223 call = rxrpc_alloc_client_call(rx, srx, gfp);
225 release_sock(&rx->sk);
226 _leave(" = %ld", PTR_ERR(call));
230 call->tx_total_len = tx_total_len;
231 trace_rxrpc_call(call, rxrpc_call_new_client, atomic_read(&call->usage),
232 here, (const void *)user_call_ID);
234 /* We need to protect a partially set up call against the user as we
235 * will be acting outside the socket lock.
237 mutex_lock(&call->user_mutex);
239 /* Publish the call, even though it is incompletely set up as yet */
240 write_lock(&rx->call_lock);
242 pp = &rx->calls.rb_node;
246 xcall = rb_entry(parent, struct rxrpc_call, sock_node);
248 if (user_call_ID < xcall->user_call_ID)
249 pp = &(*pp)->rb_left;
250 else if (user_call_ID > xcall->user_call_ID)
251 pp = &(*pp)->rb_right;
253 goto error_dup_user_ID;
256 rcu_assign_pointer(call->socket, rx);
257 call->user_call_ID = user_call_ID;
258 __set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
259 rxrpc_get_call(call, rxrpc_call_got_userid);
260 rb_link_node(&call->sock_node, parent, pp);
261 rb_insert_color(&call->sock_node, &rx->calls);
262 list_add(&call->sock_link, &rx->sock_calls);
264 write_unlock(&rx->call_lock);
266 write_lock(&rxnet->call_lock);
267 list_add_tail(&call->link, &rxnet->calls);
268 write_unlock(&rxnet->call_lock);
270 /* From this point on, the call is protected by its own lock. */
271 release_sock(&rx->sk);
273 /* Set up or get a connection record and set the protocol parameters,
274 * including channel number and call ID.
276 ret = rxrpc_connect_call(call, cp, srx, gfp);
278 goto error_attached_to_socket;
280 trace_rxrpc_call(call, rxrpc_call_connected, atomic_read(&call->usage),
283 rxrpc_start_call_timer(call);
285 _net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id);
287 _leave(" = %p [new]", call);
290 /* We unexpectedly found the user ID in the list after taking
291 * the call_lock. This shouldn't happen unless the user races
292 * with itself and tries to add the same user ID twice at the
293 * same time in different threads.
296 write_unlock(&rx->call_lock);
297 release_sock(&rx->sk);
298 __rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
299 RX_CALL_DEAD, -EEXIST);
300 trace_rxrpc_call(call, rxrpc_call_error, atomic_read(&call->usage),
301 here, ERR_PTR(-EEXIST));
302 rxrpc_release_call(rx, call);
303 mutex_unlock(&call->user_mutex);
304 rxrpc_put_call(call, rxrpc_call_put);
305 _leave(" = -EEXIST");
306 return ERR_PTR(-EEXIST);
308 /* We got an error, but the call is attached to the socket and is in
309 * need of release. However, we might now race with recvmsg() when
310 * completing the call queues it. Return 0 from sys_sendmsg() and
311 * leave the error to recvmsg() to deal with.
313 error_attached_to_socket:
314 trace_rxrpc_call(call, rxrpc_call_error, atomic_read(&call->usage),
316 set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
317 __rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
319 _leave(" = c=%08x [err]", call->debug_id);
324 * Retry a call to a new address. It is expected that the Tx queue of the call
325 * will contain data previously packaged for an old call.
327 int rxrpc_retry_client_call(struct rxrpc_sock *rx,
328 struct rxrpc_call *call,
329 struct rxrpc_conn_parameters *cp,
330 struct sockaddr_rxrpc *srx,
333 const void *here = __builtin_return_address(0);
336 /* Set up or get a connection record and set the protocol parameters,
337 * including channel number and call ID.
339 ret = rxrpc_connect_call(call, cp, srx, gfp);
343 trace_rxrpc_call(call, rxrpc_call_connected, atomic_read(&call->usage),
346 rxrpc_start_call_timer(call);
348 _net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id);
350 if (!test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
351 rxrpc_queue_call(call);
357 rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
359 trace_rxrpc_call(call, rxrpc_call_error, atomic_read(&call->usage),
361 _leave(" = %d", ret);
366 * Set up an incoming call. call->conn points to the connection.
367 * This is called in BH context and isn't allowed to fail.
369 void rxrpc_incoming_call(struct rxrpc_sock *rx,
370 struct rxrpc_call *call,
373 struct rxrpc_connection *conn = call->conn;
374 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
377 _enter(",%d", call->conn->debug_id);
379 rcu_assign_pointer(call->socket, rx);
380 call->call_id = sp->hdr.callNumber;
381 call->service_id = sp->hdr.serviceId;
382 call->cid = sp->hdr.cid;
383 call->state = RXRPC_CALL_SERVER_ACCEPTING;
384 if (sp->hdr.securityIndex > 0)
385 call->state = RXRPC_CALL_SERVER_SECURING;
386 call->cong_tstamp = skb->tstamp;
388 /* Set the channel for this call. We don't get channel_lock as we're
389 * only defending against the data_ready handler (which we're called
390 * from) and the RESPONSE packet parser (which is only really
391 * interested in call_counter and can cope with a disagreement with the
394 chan = sp->hdr.cid & RXRPC_CHANNELMASK;
395 conn->channels[chan].call_counter = call->call_id;
396 conn->channels[chan].call_id = call->call_id;
397 rcu_assign_pointer(conn->channels[chan].call, call);
399 spin_lock(&conn->params.peer->lock);
400 hlist_add_head(&call->error_link, &conn->params.peer->error_targets);
401 spin_unlock(&conn->params.peer->lock);
403 _net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id);
405 rxrpc_start_call_timer(call);
410 * Queue a call's work processor, getting a ref to pass to the work queue.
412 bool rxrpc_queue_call(struct rxrpc_call *call)
414 const void *here = __builtin_return_address(0);
415 int n = __atomic_add_unless(&call->usage, 1, 0);
418 if (rxrpc_queue_work(&call->processor))
419 trace_rxrpc_call(call, rxrpc_call_queued, n + 1, here, NULL);
421 rxrpc_put_call(call, rxrpc_call_put_noqueue);
426 * Queue a call's work processor, passing the callers ref to the work queue.
428 bool __rxrpc_queue_call(struct rxrpc_call *call)
430 const void *here = __builtin_return_address(0);
431 int n = atomic_read(&call->usage);
433 if (rxrpc_queue_work(&call->processor))
434 trace_rxrpc_call(call, rxrpc_call_queued_ref, n, here, NULL);
436 rxrpc_put_call(call, rxrpc_call_put_noqueue);
441 * Note the re-emergence of a call.
443 void rxrpc_see_call(struct rxrpc_call *call)
445 const void *here = __builtin_return_address(0);
447 int n = atomic_read(&call->usage);
449 trace_rxrpc_call(call, rxrpc_call_seen, n, here, NULL);
454 * Note the addition of a ref on a call.
456 void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
458 const void *here = __builtin_return_address(0);
459 int n = atomic_inc_return(&call->usage);
461 trace_rxrpc_call(call, op, n, here, NULL);
465 * Detach a call from its owning socket.
467 void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
469 const void *here = __builtin_return_address(0);
470 struct rxrpc_connection *conn = call->conn;
474 _enter("{%d,%d}", call->debug_id, atomic_read(&call->usage));
476 trace_rxrpc_call(call, rxrpc_call_release, atomic_read(&call->usage),
477 here, (const void *)call->flags);
479 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
481 spin_lock_bh(&call->lock);
482 if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
484 spin_unlock_bh(&call->lock);
486 del_timer_sync(&call->timer);
488 /* Make sure we don't get any more notifications */
489 write_lock_bh(&rx->recvmsg_lock);
491 if (!list_empty(&call->recvmsg_link)) {
492 _debug("unlinking once-pending call %p { e=%lx f=%lx }",
493 call, call->events, call->flags);
494 list_del(&call->recvmsg_link);
498 /* list_empty() must return false in rxrpc_notify_socket() */
499 call->recvmsg_link.next = NULL;
500 call->recvmsg_link.prev = NULL;
502 write_unlock_bh(&rx->recvmsg_lock);
504 rxrpc_put_call(call, rxrpc_call_put);
506 write_lock(&rx->call_lock);
508 if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
509 rb_erase(&call->sock_node, &rx->calls);
510 memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
511 rxrpc_put_call(call, rxrpc_call_put_userid);
514 list_del(&call->sock_link);
515 write_unlock(&rx->call_lock);
517 _debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
519 if (conn && !test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
520 rxrpc_disconnect_call(call);
522 for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) {
523 rxrpc_free_skb(call->rxtx_buffer[i],
524 (call->tx_phase ? rxrpc_skb_tx_cleaned :
525 rxrpc_skb_rx_cleaned));
526 call->rxtx_buffer[i] = NULL;
533 * Prepare a kernel service call for retry.
535 int rxrpc_prepare_call_for_retry(struct rxrpc_sock *rx, struct rxrpc_call *call)
537 const void *here = __builtin_return_address(0);
541 _enter("{%d,%d}", call->debug_id, atomic_read(&call->usage));
543 trace_rxrpc_call(call, rxrpc_call_release, atomic_read(&call->usage),
544 here, (const void *)call->flags);
546 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
547 ASSERTCMP(call->completion, !=, RXRPC_CALL_REMOTELY_ABORTED);
548 ASSERTCMP(call->completion, !=, RXRPC_CALL_LOCALLY_ABORTED);
549 ASSERT(list_empty(&call->recvmsg_link));
551 del_timer_sync(&call->timer);
553 _debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, call->conn);
556 rxrpc_disconnect_call(call);
558 if (rxrpc_is_service_call(call) ||
560 call->tx_hard_ack != 0 ||
561 call->rx_hard_ack != 0 ||
565 call->state = RXRPC_CALL_UNINITIALISED;
566 call->completion = RXRPC_CALL_SUCCEEDED;
570 call->cong_extra = 0;
571 call->cong_ssthresh = 0;
573 call->cong_dup_acks = 0;
574 call->cong_cumul_acks = 0;
575 call->acks_lowest_nak = 0;
577 for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) {
578 last |= call->rxtx_annotations[i];
579 call->rxtx_annotations[i] &= RXRPC_TX_ANNO_LAST;
580 call->rxtx_annotations[i] |= RXRPC_TX_ANNO_RETRANS;
588 * release all the calls associated with a socket
590 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
592 struct rxrpc_call *call;
596 while (!list_empty(&rx->to_be_accepted)) {
597 call = list_entry(rx->to_be_accepted.next,
598 struct rxrpc_call, accept_link);
599 list_del(&call->accept_link);
600 rxrpc_abort_call("SKR", call, 0, RX_CALL_DEAD, -ECONNRESET);
601 rxrpc_put_call(call, rxrpc_call_put);
604 while (!list_empty(&rx->sock_calls)) {
605 call = list_entry(rx->sock_calls.next,
606 struct rxrpc_call, sock_link);
607 rxrpc_get_call(call, rxrpc_call_got);
608 rxrpc_abort_call("SKT", call, 0, RX_CALL_DEAD, -ECONNRESET);
609 rxrpc_send_abort_packet(call);
610 rxrpc_release_call(rx, call);
611 rxrpc_put_call(call, rxrpc_call_put);
620 void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
622 struct rxrpc_net *rxnet;
623 const void *here = __builtin_return_address(0);
626 ASSERT(call != NULL);
628 n = atomic_dec_return(&call->usage);
629 trace_rxrpc_call(call, op, n, here, NULL);
632 _debug("call %d dead", call->debug_id);
633 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
635 if (!list_empty(&call->link)) {
636 rxnet = rxrpc_net(sock_net(&call->socket->sk));
637 write_lock(&rxnet->call_lock);
638 list_del_init(&call->link);
639 write_unlock(&rxnet->call_lock);
642 rxrpc_cleanup_call(call);
647 * Final call destruction under RCU.
649 static void rxrpc_rcu_destroy_call(struct rcu_head *rcu)
651 struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
653 rxrpc_put_connection(call->conn);
654 rxrpc_put_peer(call->peer);
655 kfree(call->rxtx_buffer);
656 kfree(call->rxtx_annotations);
657 kmem_cache_free(rxrpc_call_jar, call);
663 void rxrpc_cleanup_call(struct rxrpc_call *call)
667 _net("DESTROY CALL %d", call->debug_id);
669 memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
671 del_timer_sync(&call->timer);
673 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
674 ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
676 /* Clean up the Rx/Tx buffer */
677 for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++)
678 rxrpc_free_skb(call->rxtx_buffer[i],
679 (call->tx_phase ? rxrpc_skb_tx_cleaned :
680 rxrpc_skb_rx_cleaned));
682 rxrpc_free_skb(call->tx_pending, rxrpc_skb_tx_cleaned);
684 call_rcu(&call->rcu, rxrpc_rcu_destroy_call);
688 * Make sure that all calls are gone from a network namespace. To reach this
689 * point, any open UDP sockets in that namespace must have been closed, so any
690 * outstanding calls cannot be doing I/O.
692 void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet)
694 struct rxrpc_call *call;
698 if (!list_empty(&rxnet->calls)) {
699 write_lock(&rxnet->call_lock);
701 while (!list_empty(&rxnet->calls)) {
702 call = list_entry(rxnet->calls.next,
703 struct rxrpc_call, link);
704 _debug("Zapping call %p", call);
706 rxrpc_see_call(call);
707 list_del_init(&call->link);
709 pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
710 call, atomic_read(&call->usage),
711 rxrpc_call_states[call->state],
712 call->flags, call->events);
714 write_unlock(&rxnet->call_lock);
716 write_lock(&rxnet->call_lock);
719 write_unlock(&rxnet->call_lock);