1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* RxRPC individual remote procedure call handling
4 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10 #include <linux/slab.h>
11 #include <linux/module.h>
12 #include <linux/circ_buf.h>
13 #include <linux/spinlock_types.h>
15 #include <net/af_rxrpc.h>
16 #include "ar-internal.h"
18 const char *const rxrpc_call_states[NR__RXRPC_CALL_STATES] = {
19 [RXRPC_CALL_UNINITIALISED] = "Uninit ",
20 [RXRPC_CALL_CLIENT_AWAIT_CONN] = "ClWtConn",
21 [RXRPC_CALL_CLIENT_SEND_REQUEST] = "ClSndReq",
22 [RXRPC_CALL_CLIENT_AWAIT_REPLY] = "ClAwtRpl",
23 [RXRPC_CALL_CLIENT_RECV_REPLY] = "ClRcvRpl",
24 [RXRPC_CALL_SERVER_PREALLOC] = "SvPrealc",
25 [RXRPC_CALL_SERVER_SECURING] = "SvSecure",
26 [RXRPC_CALL_SERVER_RECV_REQUEST] = "SvRcvReq",
27 [RXRPC_CALL_SERVER_ACK_REQUEST] = "SvAckReq",
28 [RXRPC_CALL_SERVER_SEND_REPLY] = "SvSndRpl",
29 [RXRPC_CALL_SERVER_AWAIT_ACK] = "SvAwtACK",
30 [RXRPC_CALL_COMPLETE] = "Complete",
33 const char *const rxrpc_call_completions[NR__RXRPC_CALL_COMPLETIONS] = {
34 [RXRPC_CALL_SUCCEEDED] = "Complete",
35 [RXRPC_CALL_REMOTELY_ABORTED] = "RmtAbort",
36 [RXRPC_CALL_LOCALLY_ABORTED] = "LocAbort",
37 [RXRPC_CALL_LOCAL_ERROR] = "LocError",
38 [RXRPC_CALL_NETWORK_ERROR] = "NetError",
41 struct kmem_cache *rxrpc_call_jar;
43 static struct semaphore rxrpc_call_limiter =
44 __SEMAPHORE_INITIALIZER(rxrpc_call_limiter, 1000);
45 static struct semaphore rxrpc_kernel_call_limiter =
46 __SEMAPHORE_INITIALIZER(rxrpc_kernel_call_limiter, 1000);
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 call->rtt_avail = RXRPC_CALL_RTT_AVAIL_MASK;
161 atomic_inc(&rxnet->nr_calls);
165 kfree(call->rxtx_buffer);
167 kmem_cache_free(rxrpc_call_jar, call);
172 * Allocate a new client call.
174 static struct rxrpc_call *rxrpc_alloc_client_call(struct rxrpc_sock *rx,
175 struct sockaddr_rxrpc *srx,
177 unsigned int debug_id)
179 struct rxrpc_call *call;
184 call = rxrpc_alloc_call(rx, gfp, debug_id);
186 return ERR_PTR(-ENOMEM);
187 call->state = RXRPC_CALL_CLIENT_AWAIT_CONN;
188 call->service_id = srx->srx_service;
189 call->tx_phase = true;
190 now = ktime_get_real();
191 call->acks_latest_ts = now;
192 call->cong_tstamp = now;
194 _leave(" = %p", call);
199 * Initiate the call ack/resend/expiry timer.
201 static void rxrpc_start_call_timer(struct rxrpc_call *call)
203 unsigned long now = jiffies;
204 unsigned long j = now + MAX_JIFFY_OFFSET;
207 call->ack_lost_at = j;
210 call->expect_rx_by = j;
211 call->expect_req_by = j;
212 call->expect_term_by = j;
213 call->timer.expires = now;
217 * Wait for a call slot to become available.
219 static struct semaphore *rxrpc_get_call_slot(struct rxrpc_call_params *p, gfp_t gfp)
221 struct semaphore *limiter = &rxrpc_call_limiter;
224 limiter = &rxrpc_kernel_call_limiter;
225 if (p->interruptibility == RXRPC_UNINTERRUPTIBLE) {
229 return down_interruptible(limiter) < 0 ? NULL : limiter;
233 * Release a call slot.
235 static void rxrpc_put_call_slot(struct rxrpc_call *call)
237 struct semaphore *limiter = &rxrpc_call_limiter;
239 if (test_bit(RXRPC_CALL_KERNEL, &call->flags))
240 limiter = &rxrpc_kernel_call_limiter;
245 * Set up a call for the given parameters.
246 * - Called with the socket lock held, which it must release.
247 * - If it returns a call, the call's lock will need releasing by the caller.
249 struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
250 struct rxrpc_conn_parameters *cp,
251 struct sockaddr_rxrpc *srx,
252 struct rxrpc_call_params *p,
254 unsigned int debug_id)
255 __releases(&rx->sk.sk_lock.slock)
256 __acquires(&call->user_mutex)
258 struct rxrpc_call *call, *xcall;
259 struct rxrpc_net *rxnet;
260 struct semaphore *limiter;
261 struct rb_node *parent, **pp;
262 const void *here = __builtin_return_address(0);
265 _enter("%p,%lx", rx, p->user_call_ID);
267 limiter = rxrpc_get_call_slot(p, gfp);
269 return ERR_PTR(-ERESTARTSYS);
271 call = rxrpc_alloc_client_call(rx, srx, gfp, debug_id);
273 release_sock(&rx->sk);
275 _leave(" = %ld", PTR_ERR(call));
279 call->interruptibility = p->interruptibility;
280 call->tx_total_len = p->tx_total_len;
281 trace_rxrpc_call(call->debug_id, rxrpc_call_new_client,
282 atomic_read(&call->usage),
283 here, (const void *)p->user_call_ID);
285 __set_bit(RXRPC_CALL_KERNEL, &call->flags);
287 /* We need to protect a partially set up call against the user as we
288 * will be acting outside the socket lock.
290 mutex_lock(&call->user_mutex);
292 /* Publish the call, even though it is incompletely set up as yet */
293 write_lock(&rx->call_lock);
295 pp = &rx->calls.rb_node;
299 xcall = rb_entry(parent, struct rxrpc_call, sock_node);
301 if (p->user_call_ID < xcall->user_call_ID)
302 pp = &(*pp)->rb_left;
303 else if (p->user_call_ID > xcall->user_call_ID)
304 pp = &(*pp)->rb_right;
306 goto error_dup_user_ID;
309 rcu_assign_pointer(call->socket, rx);
310 call->user_call_ID = p->user_call_ID;
311 __set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
312 rxrpc_get_call(call, rxrpc_call_got_userid);
313 rb_link_node(&call->sock_node, parent, pp);
314 rb_insert_color(&call->sock_node, &rx->calls);
315 list_add(&call->sock_link, &rx->sock_calls);
317 write_unlock(&rx->call_lock);
320 write_lock(&rxnet->call_lock);
321 list_add_tail(&call->link, &rxnet->calls);
322 write_unlock(&rxnet->call_lock);
324 /* From this point on, the call is protected by its own lock. */
325 release_sock(&rx->sk);
327 /* Set up or get a connection record and set the protocol parameters,
328 * including channel number and call ID.
330 ret = rxrpc_connect_call(rx, call, cp, srx, gfp);
332 goto error_attached_to_socket;
334 trace_rxrpc_call(call->debug_id, rxrpc_call_connected,
335 atomic_read(&call->usage), here, NULL);
337 rxrpc_start_call_timer(call);
339 _net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id);
341 _leave(" = %p [new]", call);
344 /* We unexpectedly found the user ID in the list after taking
345 * the call_lock. This shouldn't happen unless the user races
346 * with itself and tries to add the same user ID twice at the
347 * same time in different threads.
350 write_unlock(&rx->call_lock);
351 release_sock(&rx->sk);
352 __rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
353 RX_CALL_DEAD, -EEXIST);
354 trace_rxrpc_call(call->debug_id, rxrpc_call_error,
355 atomic_read(&call->usage), here, ERR_PTR(-EEXIST));
356 rxrpc_release_call(rx, call);
357 mutex_unlock(&call->user_mutex);
358 rxrpc_put_call(call, rxrpc_call_put);
359 _leave(" = -EEXIST");
360 return ERR_PTR(-EEXIST);
362 /* We got an error, but the call is attached to the socket and is in
363 * need of release. However, we might now race with recvmsg() when
364 * completing the call queues it. Return 0 from sys_sendmsg() and
365 * leave the error to recvmsg() to deal with.
367 error_attached_to_socket:
368 trace_rxrpc_call(call->debug_id, rxrpc_call_error,
369 atomic_read(&call->usage), here, ERR_PTR(ret));
370 set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
371 __rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
373 _leave(" = c=%08x [err]", call->debug_id);
378 * Set up an incoming call. call->conn points to the connection.
379 * This is called in BH context and isn't allowed to fail.
381 void rxrpc_incoming_call(struct rxrpc_sock *rx,
382 struct rxrpc_call *call,
385 struct rxrpc_connection *conn = call->conn;
386 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
389 _enter(",%d", call->conn->debug_id);
391 rcu_assign_pointer(call->socket, rx);
392 call->call_id = sp->hdr.callNumber;
393 call->service_id = sp->hdr.serviceId;
394 call->cid = sp->hdr.cid;
395 call->state = RXRPC_CALL_SERVER_SECURING;
396 call->cong_tstamp = skb->tstamp;
398 /* Set the channel for this call. We don't get channel_lock as we're
399 * only defending against the data_ready handler (which we're called
400 * from) and the RESPONSE packet parser (which is only really
401 * interested in call_counter and can cope with a disagreement with the
404 chan = sp->hdr.cid & RXRPC_CHANNELMASK;
405 conn->channels[chan].call_counter = call->call_id;
406 conn->channels[chan].call_id = call->call_id;
407 rcu_assign_pointer(conn->channels[chan].call, call);
409 spin_lock(&conn->params.peer->lock);
410 hlist_add_head_rcu(&call->error_link, &conn->params.peer->error_targets);
411 spin_unlock(&conn->params.peer->lock);
413 _net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id);
415 rxrpc_start_call_timer(call);
420 * Queue a call's work processor, getting a ref to pass to the work queue.
422 bool rxrpc_queue_call(struct rxrpc_call *call)
424 const void *here = __builtin_return_address(0);
425 int n = atomic_fetch_add_unless(&call->usage, 1, 0);
428 if (rxrpc_queue_work(&call->processor))
429 trace_rxrpc_call(call->debug_id, rxrpc_call_queued, n + 1,
432 rxrpc_put_call(call, rxrpc_call_put_noqueue);
437 * Queue a call's work processor, passing the callers ref to the work queue.
439 bool __rxrpc_queue_call(struct rxrpc_call *call)
441 const void *here = __builtin_return_address(0);
442 int n = atomic_read(&call->usage);
444 if (rxrpc_queue_work(&call->processor))
445 trace_rxrpc_call(call->debug_id, rxrpc_call_queued_ref, n,
448 rxrpc_put_call(call, rxrpc_call_put_noqueue);
453 * Note the re-emergence of a call.
455 void rxrpc_see_call(struct rxrpc_call *call)
457 const void *here = __builtin_return_address(0);
459 int n = atomic_read(&call->usage);
461 trace_rxrpc_call(call->debug_id, rxrpc_call_seen, n,
467 * Note the addition of a ref on a call.
469 void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
471 const void *here = __builtin_return_address(0);
472 int n = atomic_inc_return(&call->usage);
474 trace_rxrpc_call(call->debug_id, op, n, here, NULL);
478 * Clean up the RxTx skb ring.
480 static void rxrpc_cleanup_ring(struct rxrpc_call *call)
484 for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) {
485 rxrpc_free_skb(call->rxtx_buffer[i], rxrpc_skb_cleaned);
486 call->rxtx_buffer[i] = NULL;
491 * Detach a call from its owning socket.
493 void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
495 const void *here = __builtin_return_address(0);
496 struct rxrpc_connection *conn = call->conn;
499 _enter("{%d,%d}", call->debug_id, atomic_read(&call->usage));
501 trace_rxrpc_call(call->debug_id, rxrpc_call_release,
502 atomic_read(&call->usage),
503 here, (const void *)call->flags);
505 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
507 spin_lock_bh(&call->lock);
508 if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
510 spin_unlock_bh(&call->lock);
512 rxrpc_put_call_slot(call);
514 del_timer_sync(&call->timer);
516 /* Make sure we don't get any more notifications */
517 write_lock_bh(&rx->recvmsg_lock);
519 if (!list_empty(&call->recvmsg_link)) {
520 _debug("unlinking once-pending call %p { e=%lx f=%lx }",
521 call, call->events, call->flags);
522 list_del(&call->recvmsg_link);
526 /* list_empty() must return false in rxrpc_notify_socket() */
527 call->recvmsg_link.next = NULL;
528 call->recvmsg_link.prev = NULL;
530 write_unlock_bh(&rx->recvmsg_lock);
532 rxrpc_put_call(call, rxrpc_call_put);
534 write_lock(&rx->call_lock);
536 if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
537 rb_erase(&call->sock_node, &rx->calls);
538 memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
539 rxrpc_put_call(call, rxrpc_call_put_userid);
542 list_del(&call->sock_link);
543 write_unlock(&rx->call_lock);
545 _debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
547 if (conn && !test_bit(RXRPC_CALL_DISCONNECTED, &call->flags))
548 rxrpc_disconnect_call(call);
550 call->security->free_call_crypto(call);
552 rxrpc_cleanup_ring(call);
557 * release all the calls associated with a socket
559 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
561 struct rxrpc_call *call;
565 while (!list_empty(&rx->to_be_accepted)) {
566 call = list_entry(rx->to_be_accepted.next,
567 struct rxrpc_call, accept_link);
568 list_del(&call->accept_link);
569 rxrpc_abort_call("SKR", call, 0, RX_CALL_DEAD, -ECONNRESET);
570 rxrpc_put_call(call, rxrpc_call_put);
573 while (!list_empty(&rx->sock_calls)) {
574 call = list_entry(rx->sock_calls.next,
575 struct rxrpc_call, sock_link);
576 rxrpc_get_call(call, rxrpc_call_got);
577 rxrpc_abort_call("SKT", call, 0, RX_CALL_DEAD, -ECONNRESET);
578 rxrpc_send_abort_packet(call);
579 rxrpc_release_call(rx, call);
580 rxrpc_put_call(call, rxrpc_call_put);
589 void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
591 struct rxrpc_net *rxnet = call->rxnet;
592 const void *here = __builtin_return_address(0);
593 unsigned int debug_id = call->debug_id;
596 ASSERT(call != NULL);
598 n = atomic_dec_return(&call->usage);
599 trace_rxrpc_call(debug_id, op, n, here, NULL);
602 _debug("call %d dead", call->debug_id);
603 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
605 if (!list_empty(&call->link)) {
606 write_lock(&rxnet->call_lock);
607 list_del_init(&call->link);
608 write_unlock(&rxnet->call_lock);
611 rxrpc_cleanup_call(call);
616 * Final call destruction - but must be done in process context.
618 static void rxrpc_destroy_call(struct work_struct *work)
620 struct rxrpc_call *call = container_of(work, struct rxrpc_call, processor);
621 struct rxrpc_net *rxnet = call->rxnet;
623 rxrpc_put_connection(call->conn);
624 rxrpc_put_peer(call->peer);
625 kfree(call->rxtx_buffer);
626 kfree(call->rxtx_annotations);
627 kmem_cache_free(rxrpc_call_jar, call);
628 if (atomic_dec_and_test(&rxnet->nr_calls))
629 wake_up_var(&rxnet->nr_calls);
633 * Final call destruction under RCU.
635 static void rxrpc_rcu_destroy_call(struct rcu_head *rcu)
637 struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
640 INIT_WORK(&call->processor, rxrpc_destroy_call);
641 if (!rxrpc_queue_work(&call->processor))
644 rxrpc_destroy_call(&call->processor);
651 void rxrpc_cleanup_call(struct rxrpc_call *call)
653 _net("DESTROY CALL %d", call->debug_id);
655 memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
657 del_timer_sync(&call->timer);
659 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
660 ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
662 rxrpc_cleanup_ring(call);
663 rxrpc_free_skb(call->tx_pending, rxrpc_skb_cleaned);
665 call_rcu(&call->rcu, rxrpc_rcu_destroy_call);
669 * Make sure that all calls are gone from a network namespace. To reach this
670 * point, any open UDP sockets in that namespace must have been closed, so any
671 * outstanding calls cannot be doing I/O.
673 void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet)
675 struct rxrpc_call *call;
679 if (!list_empty(&rxnet->calls)) {
680 write_lock(&rxnet->call_lock);
682 while (!list_empty(&rxnet->calls)) {
683 call = list_entry(rxnet->calls.next,
684 struct rxrpc_call, link);
685 _debug("Zapping call %p", call);
687 rxrpc_see_call(call);
688 list_del_init(&call->link);
690 pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
691 call, atomic_read(&call->usage),
692 rxrpc_call_states[call->state],
693 call->flags, call->events);
695 write_unlock(&rxnet->call_lock);
697 write_lock(&rxnet->call_lock);
700 write_unlock(&rxnet->call_lock);
703 atomic_dec(&rxnet->nr_calls);
704 wait_var_event(&rxnet->nr_calls, !atomic_read(&rxnet->nr_calls));