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));
245 __set_bit(RXRPC_CALL_IS_INTR, &call->flags);
246 call->tx_total_len = p->tx_total_len;
247 trace_rxrpc_call(call, rxrpc_call_new_client, atomic_read(&call->usage),
248 here, (const void *)p->user_call_ID);
250 /* We need to protect a partially set up call against the user as we
251 * will be acting outside the socket lock.
253 mutex_lock(&call->user_mutex);
255 /* Publish the call, even though it is incompletely set up as yet */
256 write_lock(&rx->call_lock);
258 pp = &rx->calls.rb_node;
262 xcall = rb_entry(parent, struct rxrpc_call, sock_node);
264 if (p->user_call_ID < xcall->user_call_ID)
265 pp = &(*pp)->rb_left;
266 else if (p->user_call_ID > xcall->user_call_ID)
267 pp = &(*pp)->rb_right;
269 goto error_dup_user_ID;
272 rcu_assign_pointer(call->socket, rx);
273 call->user_call_ID = p->user_call_ID;
274 __set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
275 rxrpc_get_call(call, rxrpc_call_got_userid);
276 rb_link_node(&call->sock_node, parent, pp);
277 rb_insert_color(&call->sock_node, &rx->calls);
278 list_add(&call->sock_link, &rx->sock_calls);
280 write_unlock(&rx->call_lock);
283 write_lock(&rxnet->call_lock);
284 list_add_tail(&call->link, &rxnet->calls);
285 write_unlock(&rxnet->call_lock);
287 /* From this point on, the call is protected by its own lock. */
288 release_sock(&rx->sk);
290 /* Set up or get a connection record and set the protocol parameters,
291 * including channel number and call ID.
293 ret = rxrpc_connect_call(rx, call, cp, srx, gfp);
297 trace_rxrpc_call(call, rxrpc_call_connected, atomic_read(&call->usage),
300 rxrpc_start_call_timer(call);
302 _net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id);
304 _leave(" = %p [new]", call);
307 /* We unexpectedly found the user ID in the list after taking
308 * the call_lock. This shouldn't happen unless the user races
309 * with itself and tries to add the same user ID twice at the
310 * same time in different threads.
313 write_unlock(&rx->call_lock);
314 release_sock(&rx->sk);
318 __rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
320 trace_rxrpc_call(call, rxrpc_call_error, atomic_read(&call->usage),
322 rxrpc_release_call(rx, call);
323 mutex_unlock(&call->user_mutex);
324 rxrpc_put_call(call, rxrpc_call_put);
325 _leave(" = %d", ret);
330 * Set up an incoming call. call->conn points to the connection.
331 * This is called in BH context and isn't allowed to fail.
333 void rxrpc_incoming_call(struct rxrpc_sock *rx,
334 struct rxrpc_call *call,
337 struct rxrpc_connection *conn = call->conn;
338 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
341 _enter(",%d", call->conn->debug_id);
343 rcu_assign_pointer(call->socket, rx);
344 call->call_id = sp->hdr.callNumber;
345 call->service_id = sp->hdr.serviceId;
346 call->cid = sp->hdr.cid;
347 call->state = RXRPC_CALL_SERVER_ACCEPTING;
348 if (sp->hdr.securityIndex > 0)
349 call->state = RXRPC_CALL_SERVER_SECURING;
350 call->cong_tstamp = skb->tstamp;
352 /* Set the channel for this call. We don't get channel_lock as we're
353 * only defending against the data_ready handler (which we're called
354 * from) and the RESPONSE packet parser (which is only really
355 * interested in call_counter and can cope with a disagreement with the
358 chan = sp->hdr.cid & RXRPC_CHANNELMASK;
359 conn->channels[chan].call_counter = call->call_id;
360 conn->channels[chan].call_id = call->call_id;
361 rcu_assign_pointer(conn->channels[chan].call, call);
363 spin_lock(&conn->params.peer->lock);
364 hlist_add_head_rcu(&call->error_link, &conn->params.peer->error_targets);
365 spin_unlock(&conn->params.peer->lock);
367 _net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id);
369 rxrpc_start_call_timer(call);
374 * Queue a call's work processor, getting a ref to pass to the work queue.
376 bool rxrpc_queue_call(struct rxrpc_call *call)
378 const void *here = __builtin_return_address(0);
379 int n = atomic_fetch_add_unless(&call->usage, 1, 0);
382 if (rxrpc_queue_work(&call->processor))
383 trace_rxrpc_call(call, rxrpc_call_queued, n + 1, here, NULL);
385 rxrpc_put_call(call, rxrpc_call_put_noqueue);
390 * Queue a call's work processor, passing the callers ref to the work queue.
392 bool __rxrpc_queue_call(struct rxrpc_call *call)
394 const void *here = __builtin_return_address(0);
395 int n = atomic_read(&call->usage);
397 if (rxrpc_queue_work(&call->processor))
398 trace_rxrpc_call(call, rxrpc_call_queued_ref, n, here, NULL);
400 rxrpc_put_call(call, rxrpc_call_put_noqueue);
405 * Note the re-emergence of a call.
407 void rxrpc_see_call(struct rxrpc_call *call)
409 const void *here = __builtin_return_address(0);
411 int n = atomic_read(&call->usage);
413 trace_rxrpc_call(call, rxrpc_call_seen, n, here, NULL);
418 * Note the addition of a ref on a call.
420 void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
422 const void *here = __builtin_return_address(0);
423 int n = atomic_inc_return(&call->usage);
425 trace_rxrpc_call(call, op, n, here, NULL);
429 * Detach a call from its owning socket.
431 void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
433 const void *here = __builtin_return_address(0);
434 struct rxrpc_connection *conn = call->conn;
438 _enter("{%d,%d}", call->debug_id, atomic_read(&call->usage));
440 trace_rxrpc_call(call, rxrpc_call_release, atomic_read(&call->usage),
441 here, (const void *)call->flags);
443 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
445 spin_lock_bh(&call->lock);
446 if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
448 spin_unlock_bh(&call->lock);
450 del_timer_sync(&call->timer);
452 /* Make sure we don't get any more notifications */
453 write_lock_bh(&rx->recvmsg_lock);
455 if (!list_empty(&call->recvmsg_link)) {
456 _debug("unlinking once-pending call %p { e=%lx f=%lx }",
457 call, call->events, call->flags);
458 list_del(&call->recvmsg_link);
462 /* list_empty() must return false in rxrpc_notify_socket() */
463 call->recvmsg_link.next = NULL;
464 call->recvmsg_link.prev = NULL;
466 write_unlock_bh(&rx->recvmsg_lock);
468 rxrpc_put_call(call, rxrpc_call_put);
470 write_lock(&rx->call_lock);
472 if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
473 rb_erase(&call->sock_node, &rx->calls);
474 memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
475 rxrpc_put_call(call, rxrpc_call_put_userid);
478 list_del(&call->sock_link);
479 write_unlock(&rx->call_lock);
481 _debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
484 rxrpc_disconnect_call(call);
486 for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) {
487 rxrpc_free_skb(call->rxtx_buffer[i],
488 (call->tx_phase ? rxrpc_skb_tx_cleaned :
489 rxrpc_skb_rx_cleaned));
490 call->rxtx_buffer[i] = NULL;
497 * release all the calls associated with a socket
499 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
501 struct rxrpc_call *call;
505 while (!list_empty(&rx->to_be_accepted)) {
506 call = list_entry(rx->to_be_accepted.next,
507 struct rxrpc_call, accept_link);
508 list_del(&call->accept_link);
509 rxrpc_abort_call("SKR", call, 0, RX_CALL_DEAD, -ECONNRESET);
510 rxrpc_put_call(call, rxrpc_call_put);
513 while (!list_empty(&rx->sock_calls)) {
514 call = list_entry(rx->sock_calls.next,
515 struct rxrpc_call, sock_link);
516 rxrpc_get_call(call, rxrpc_call_got);
517 rxrpc_abort_call("SKT", call, 0, RX_CALL_DEAD, -ECONNRESET);
518 rxrpc_send_abort_packet(call);
519 rxrpc_release_call(rx, call);
520 rxrpc_put_call(call, rxrpc_call_put);
529 void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
531 struct rxrpc_net *rxnet = call->rxnet;
532 const void *here = __builtin_return_address(0);
535 ASSERT(call != NULL);
537 n = atomic_dec_return(&call->usage);
538 trace_rxrpc_call(call, op, n, here, NULL);
541 _debug("call %d dead", call->debug_id);
542 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
544 if (!list_empty(&call->link)) {
545 write_lock(&rxnet->call_lock);
546 list_del_init(&call->link);
547 write_unlock(&rxnet->call_lock);
550 rxrpc_cleanup_call(call);
555 * Final call destruction under RCU.
557 static void rxrpc_rcu_destroy_call(struct rcu_head *rcu)
559 struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
560 struct rxrpc_net *rxnet = call->rxnet;
562 rxrpc_put_peer(call->peer);
563 kfree(call->rxtx_buffer);
564 kfree(call->rxtx_annotations);
565 kmem_cache_free(rxrpc_call_jar, call);
566 if (atomic_dec_and_test(&rxnet->nr_calls))
567 wake_up_var(&rxnet->nr_calls);
573 void rxrpc_cleanup_call(struct rxrpc_call *call)
577 _net("DESTROY CALL %d", call->debug_id);
579 memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
581 del_timer_sync(&call->timer);
583 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
584 ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
585 ASSERTCMP(call->conn, ==, NULL);
587 /* Clean up the Rx/Tx buffer */
588 for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++)
589 rxrpc_free_skb(call->rxtx_buffer[i],
590 (call->tx_phase ? rxrpc_skb_tx_cleaned :
591 rxrpc_skb_rx_cleaned));
593 rxrpc_free_skb(call->tx_pending, rxrpc_skb_tx_cleaned);
595 call_rcu(&call->rcu, rxrpc_rcu_destroy_call);
599 * Make sure that all calls are gone from a network namespace. To reach this
600 * point, any open UDP sockets in that namespace must have been closed, so any
601 * outstanding calls cannot be doing I/O.
603 void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet)
605 struct rxrpc_call *call;
609 if (!list_empty(&rxnet->calls)) {
610 write_lock(&rxnet->call_lock);
612 while (!list_empty(&rxnet->calls)) {
613 call = list_entry(rxnet->calls.next,
614 struct rxrpc_call, link);
615 _debug("Zapping call %p", call);
617 rxrpc_see_call(call);
618 list_del_init(&call->link);
620 pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
621 call, atomic_read(&call->usage),
622 rxrpc_call_states[call->state],
623 call->flags, call->events);
625 write_unlock(&rxnet->call_lock);
627 write_lock(&rxnet->call_lock);
630 write_unlock(&rxnet->call_lock);
633 atomic_dec(&rxnet->nr_calls);
634 wait_var_event(&rxnet->nr_calls, !atomic_read(&rxnet->nr_calls));