Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
[cascardo/linux.git] / net / rxrpc / call_object.c
1 /* RxRPC individual remote procedure call handling
2  *
3  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4  * Written by David Howells (dhowells@redhat.com)
5  *
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.
10  */
11
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14 #include <linux/slab.h>
15 #include <linux/module.h>
16 #include <linux/circ_buf.h>
17 #include <linux/spinlock_types.h>
18 #include <net/sock.h>
19 #include <net/af_rxrpc.h>
20 #include "ar-internal.h"
21
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",
36 };
37
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",
44 };
45
46 const char rxrpc_call_traces[rxrpc_call__nr_trace][4] = {
47         [rxrpc_call_new_client]         = "NWc",
48         [rxrpc_call_new_service]        = "NWs",
49         [rxrpc_call_queued]             = "QUE",
50         [rxrpc_call_queued_ref]         = "QUR",
51         [rxrpc_call_connected]          = "CON",
52         [rxrpc_call_release]            = "RLS",
53         [rxrpc_call_seen]               = "SEE",
54         [rxrpc_call_got]                = "GOT",
55         [rxrpc_call_got_userid]         = "Gus",
56         [rxrpc_call_got_kernel]         = "Gke",
57         [rxrpc_call_put]                = "PUT",
58         [rxrpc_call_put_userid]         = "Pus",
59         [rxrpc_call_put_kernel]         = "Pke",
60         [rxrpc_call_put_noqueue]        = "PNQ",
61         [rxrpc_call_error]              = "*E*",
62 };
63
64 struct kmem_cache *rxrpc_call_jar;
65 LIST_HEAD(rxrpc_calls);
66 DEFINE_RWLOCK(rxrpc_call_lock);
67
68 static void rxrpc_call_timer_expired(unsigned long _call)
69 {
70         struct rxrpc_call *call = (struct rxrpc_call *)_call;
71
72         _enter("%d", call->debug_id);
73
74         if (call->state < RXRPC_CALL_COMPLETE)
75                 rxrpc_set_timer(call, rxrpc_timer_expired, ktime_get_real());
76 }
77
78 /*
79  * find an extant server call
80  * - called in process context with IRQs enabled
81  */
82 struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx,
83                                               unsigned long user_call_ID)
84 {
85         struct rxrpc_call *call;
86         struct rb_node *p;
87
88         _enter("%p,%lx", rx, user_call_ID);
89
90         read_lock(&rx->call_lock);
91
92         p = rx->calls.rb_node;
93         while (p) {
94                 call = rb_entry(p, struct rxrpc_call, sock_node);
95
96                 if (user_call_ID < call->user_call_ID)
97                         p = p->rb_left;
98                 else if (user_call_ID > call->user_call_ID)
99                         p = p->rb_right;
100                 else
101                         goto found_extant_call;
102         }
103
104         read_unlock(&rx->call_lock);
105         _leave(" = NULL");
106         return NULL;
107
108 found_extant_call:
109         rxrpc_get_call(call, rxrpc_call_got);
110         read_unlock(&rx->call_lock);
111         _leave(" = %p [%d]", call, atomic_read(&call->usage));
112         return call;
113 }
114
115 /*
116  * allocate a new call
117  */
118 struct rxrpc_call *rxrpc_alloc_call(gfp_t gfp)
119 {
120         struct rxrpc_call *call;
121
122         call = kmem_cache_zalloc(rxrpc_call_jar, gfp);
123         if (!call)
124                 return NULL;
125
126         call->rxtx_buffer = kcalloc(RXRPC_RXTX_BUFF_SIZE,
127                                     sizeof(struct sk_buff *),
128                                     gfp);
129         if (!call->rxtx_buffer)
130                 goto nomem;
131
132         call->rxtx_annotations = kcalloc(RXRPC_RXTX_BUFF_SIZE, sizeof(u8), gfp);
133         if (!call->rxtx_annotations)
134                 goto nomem_2;
135
136         setup_timer(&call->timer, rxrpc_call_timer_expired,
137                     (unsigned long)call);
138         INIT_WORK(&call->processor, &rxrpc_process_call);
139         INIT_LIST_HEAD(&call->link);
140         INIT_LIST_HEAD(&call->chan_wait_link);
141         INIT_LIST_HEAD(&call->accept_link);
142         INIT_LIST_HEAD(&call->recvmsg_link);
143         INIT_LIST_HEAD(&call->sock_link);
144         init_waitqueue_head(&call->waitq);
145         spin_lock_init(&call->lock);
146         rwlock_init(&call->state_lock);
147         atomic_set(&call->usage, 1);
148         call->debug_id = atomic_inc_return(&rxrpc_debug_id);
149
150         memset(&call->sock_node, 0xed, sizeof(call->sock_node));
151
152         /* Leave space in the ring to handle a maxed-out jumbo packet */
153         call->rx_winsize = rxrpc_rx_window_size;
154         call->tx_winsize = 16;
155         call->rx_expect_next = 1;
156
157         if (RXRPC_TX_SMSS > 2190)
158                 call->cong_cwnd = 2;
159         else if (RXRPC_TX_SMSS > 1095)
160                 call->cong_cwnd = 3;
161         else
162                 call->cong_cwnd = 4;
163         call->cong_ssthresh = RXRPC_RXTX_BUFF_SIZE - 1;
164         return call;
165
166 nomem_2:
167         kfree(call->rxtx_buffer);
168 nomem:
169         kmem_cache_free(rxrpc_call_jar, call);
170         return NULL;
171 }
172
173 /*
174  * Allocate a new client call.
175  */
176 static struct rxrpc_call *rxrpc_alloc_client_call(struct sockaddr_rxrpc *srx,
177                                                   gfp_t gfp)
178 {
179         struct rxrpc_call *call;
180         ktime_t now;
181
182         _enter("");
183
184         call = rxrpc_alloc_call(gfp);
185         if (!call)
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;
193
194         _leave(" = %p", call);
195         return call;
196 }
197
198 /*
199  * Initiate the call ack/resend/expiry timer.
200  */
201 static void rxrpc_start_call_timer(struct rxrpc_call *call)
202 {
203         ktime_t now = ktime_get_real(), expire_at;
204
205         expire_at = ktime_add_ms(now, rxrpc_max_call_lifetime);
206         call->expire_at = expire_at;
207         call->ack_at = expire_at;
208         call->resend_at = expire_at;
209         call->timer.expires = jiffies + LONG_MAX / 2;
210         rxrpc_set_timer(call, rxrpc_timer_begin, now);
211 }
212
213 /*
214  * set up a call for the given data
215  * - called in process context with IRQs enabled
216  */
217 struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
218                                          struct rxrpc_conn_parameters *cp,
219                                          struct sockaddr_rxrpc *srx,
220                                          unsigned long user_call_ID,
221                                          gfp_t gfp)
222 {
223         struct rxrpc_call *call, *xcall;
224         struct rb_node *parent, **pp;
225         const void *here = __builtin_return_address(0);
226         int ret;
227
228         _enter("%p,%lx", rx, user_call_ID);
229
230         call = rxrpc_alloc_client_call(srx, gfp);
231         if (IS_ERR(call)) {
232                 _leave(" = %ld", PTR_ERR(call));
233                 return call;
234         }
235
236         trace_rxrpc_call(call, rxrpc_call_new_client, atomic_read(&call->usage),
237                          here, (const void *)user_call_ID);
238
239         /* Publish the call, even though it is incompletely set up as yet */
240         write_lock(&rx->call_lock);
241
242         pp = &rx->calls.rb_node;
243         parent = NULL;
244         while (*pp) {
245                 parent = *pp;
246                 xcall = rb_entry(parent, struct rxrpc_call, sock_node);
247
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;
252                 else
253                         goto error_dup_user_ID;
254         }
255
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);
263
264         write_unlock(&rx->call_lock);
265
266         write_lock(&rxrpc_call_lock);
267         list_add_tail(&call->link, &rxrpc_calls);
268         write_unlock(&rxrpc_call_lock);
269
270         /* Set up or get a connection record and set the protocol parameters,
271          * including channel number and call ID.
272          */
273         ret = rxrpc_connect_call(call, cp, srx, gfp);
274         if (ret < 0)
275                 goto error;
276
277         trace_rxrpc_call(call, rxrpc_call_connected, atomic_read(&call->usage),
278                          here, ERR_PTR(ret));
279
280         spin_lock_bh(&call->conn->params.peer->lock);
281         hlist_add_head(&call->error_link,
282                        &call->conn->params.peer->error_targets);
283         spin_unlock_bh(&call->conn->params.peer->lock);
284
285         rxrpc_start_call_timer(call);
286
287         _net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id);
288
289         _leave(" = %p [new]", call);
290         return call;
291
292         /* We unexpectedly found the user ID in the list after taking
293          * the call_lock.  This shouldn't happen unless the user races
294          * with itself and tries to add the same user ID twice at the
295          * same time in different threads.
296          */
297 error_dup_user_ID:
298         write_unlock(&rx->call_lock);
299         ret = -EEXIST;
300
301 error:
302         __rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
303                                     RX_CALL_DEAD, ret);
304         trace_rxrpc_call(call, rxrpc_call_error, atomic_read(&call->usage),
305                          here, ERR_PTR(ret));
306         rxrpc_release_call(rx, call);
307         rxrpc_put_call(call, rxrpc_call_put);
308         _leave(" = %d", ret);
309         return ERR_PTR(ret);
310 }
311
312 /*
313  * Set up an incoming call.  call->conn points to the connection.
314  * This is called in BH context and isn't allowed to fail.
315  */
316 void rxrpc_incoming_call(struct rxrpc_sock *rx,
317                          struct rxrpc_call *call,
318                          struct sk_buff *skb)
319 {
320         struct rxrpc_connection *conn = call->conn;
321         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
322         u32 chan;
323
324         _enter(",%d", call->conn->debug_id);
325
326         rcu_assign_pointer(call->socket, rx);
327         call->call_id           = sp->hdr.callNumber;
328         call->service_id        = sp->hdr.serviceId;
329         call->cid               = sp->hdr.cid;
330         call->state             = RXRPC_CALL_SERVER_ACCEPTING;
331         if (sp->hdr.securityIndex > 0)
332                 call->state     = RXRPC_CALL_SERVER_SECURING;
333         call->cong_tstamp       = skb->tstamp;
334
335         /* Set the channel for this call.  We don't get channel_lock as we're
336          * only defending against the data_ready handler (which we're called
337          * from) and the RESPONSE packet parser (which is only really
338          * interested in call_counter and can cope with a disagreement with the
339          * call pointer).
340          */
341         chan = sp->hdr.cid & RXRPC_CHANNELMASK;
342         conn->channels[chan].call_counter = call->call_id;
343         conn->channels[chan].call_id = call->call_id;
344         rcu_assign_pointer(conn->channels[chan].call, call);
345
346         spin_lock(&conn->params.peer->lock);
347         hlist_add_head(&call->error_link, &conn->params.peer->error_targets);
348         spin_unlock(&conn->params.peer->lock);
349
350         _net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id);
351
352         rxrpc_start_call_timer(call);
353         _leave("");
354 }
355
356 /*
357  * Queue a call's work processor, getting a ref to pass to the work queue.
358  */
359 bool rxrpc_queue_call(struct rxrpc_call *call)
360 {
361         const void *here = __builtin_return_address(0);
362         int n = __atomic_add_unless(&call->usage, 1, 0);
363         if (n == 0)
364                 return false;
365         if (rxrpc_queue_work(&call->processor))
366                 trace_rxrpc_call(call, rxrpc_call_queued, n + 1, here, NULL);
367         else
368                 rxrpc_put_call(call, rxrpc_call_put_noqueue);
369         return true;
370 }
371
372 /*
373  * Queue a call's work processor, passing the callers ref to the work queue.
374  */
375 bool __rxrpc_queue_call(struct rxrpc_call *call)
376 {
377         const void *here = __builtin_return_address(0);
378         int n = atomic_read(&call->usage);
379         ASSERTCMP(n, >=, 1);
380         if (rxrpc_queue_work(&call->processor))
381                 trace_rxrpc_call(call, rxrpc_call_queued_ref, n, here, NULL);
382         else
383                 rxrpc_put_call(call, rxrpc_call_put_noqueue);
384         return true;
385 }
386
387 /*
388  * Note the re-emergence of a call.
389  */
390 void rxrpc_see_call(struct rxrpc_call *call)
391 {
392         const void *here = __builtin_return_address(0);
393         if (call) {
394                 int n = atomic_read(&call->usage);
395
396                 trace_rxrpc_call(call, rxrpc_call_seen, n, here, NULL);
397         }
398 }
399
400 /*
401  * Note the addition of a ref on a call.
402  */
403 void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
404 {
405         const void *here = __builtin_return_address(0);
406         int n = atomic_inc_return(&call->usage);
407
408         trace_rxrpc_call(call, op, n, here, NULL);
409 }
410
411 /*
412  * Detach a call from its owning socket.
413  */
414 void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
415 {
416         const void *here = __builtin_return_address(0);
417         struct rxrpc_connection *conn = call->conn;
418         bool put = false;
419         int i;
420
421         _enter("{%d,%d}", call->debug_id, atomic_read(&call->usage));
422
423         trace_rxrpc_call(call, rxrpc_call_release, atomic_read(&call->usage),
424                          here, (const void *)call->flags);
425
426         ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
427
428         spin_lock_bh(&call->lock);
429         if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
430                 BUG();
431         spin_unlock_bh(&call->lock);
432
433         del_timer_sync(&call->timer);
434
435         /* Make sure we don't get any more notifications */
436         write_lock_bh(&rx->recvmsg_lock);
437
438         if (!list_empty(&call->recvmsg_link)) {
439                 _debug("unlinking once-pending call %p { e=%lx f=%lx }",
440                        call, call->events, call->flags);
441                 list_del(&call->recvmsg_link);
442                 put = true;
443         }
444
445         /* list_empty() must return false in rxrpc_notify_socket() */
446         call->recvmsg_link.next = NULL;
447         call->recvmsg_link.prev = NULL;
448
449         write_unlock_bh(&rx->recvmsg_lock);
450         if (put)
451                 rxrpc_put_call(call, rxrpc_call_put);
452
453         write_lock(&rx->call_lock);
454
455         if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
456                 rb_erase(&call->sock_node, &rx->calls);
457                 memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
458                 rxrpc_put_call(call, rxrpc_call_put_userid);
459         }
460
461         list_del(&call->sock_link);
462         write_unlock(&rx->call_lock);
463
464         _debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
465
466         if (conn)
467                 rxrpc_disconnect_call(call);
468
469         for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) {
470                 rxrpc_free_skb(call->rxtx_buffer[i],
471                                (call->tx_phase ? rxrpc_skb_tx_cleaned :
472                                 rxrpc_skb_rx_cleaned));
473                 call->rxtx_buffer[i] = NULL;
474         }
475
476         _leave("");
477 }
478
479 /*
480  * release all the calls associated with a socket
481  */
482 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
483 {
484         struct rxrpc_call *call;
485
486         _enter("%p", rx);
487
488         while (!list_empty(&rx->to_be_accepted)) {
489                 call = list_entry(rx->to_be_accepted.next,
490                                   struct rxrpc_call, accept_link);
491                 list_del(&call->accept_link);
492                 rxrpc_abort_call("SKR", call, 0, RX_CALL_DEAD, ECONNRESET);
493                 rxrpc_put_call(call, rxrpc_call_put);
494         }
495
496         while (!list_empty(&rx->sock_calls)) {
497                 call = list_entry(rx->sock_calls.next,
498                                   struct rxrpc_call, sock_link);
499                 rxrpc_get_call(call, rxrpc_call_got);
500                 rxrpc_abort_call("SKT", call, 0, RX_CALL_DEAD, ECONNRESET);
501                 rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ABORT);
502                 rxrpc_release_call(rx, call);
503                 rxrpc_put_call(call, rxrpc_call_put);
504         }
505
506         _leave("");
507 }
508
509 /*
510  * release a call
511  */
512 void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
513 {
514         const void *here = __builtin_return_address(0);
515         int n;
516
517         ASSERT(call != NULL);
518
519         n = atomic_dec_return(&call->usage);
520         trace_rxrpc_call(call, op, n, here, NULL);
521         ASSERTCMP(n, >=, 0);
522         if (n == 0) {
523                 _debug("call %d dead", call->debug_id);
524                 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
525
526                 write_lock(&rxrpc_call_lock);
527                 list_del_init(&call->link);
528                 write_unlock(&rxrpc_call_lock);
529
530                 rxrpc_cleanup_call(call);
531         }
532 }
533
534 /*
535  * Final call destruction under RCU.
536  */
537 static void rxrpc_rcu_destroy_call(struct rcu_head *rcu)
538 {
539         struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
540
541         rxrpc_put_peer(call->peer);
542         kfree(call->rxtx_buffer);
543         kfree(call->rxtx_annotations);
544         kmem_cache_free(rxrpc_call_jar, call);
545 }
546
547 /*
548  * clean up a call
549  */
550 void rxrpc_cleanup_call(struct rxrpc_call *call)
551 {
552         int i;
553
554         _net("DESTROY CALL %d", call->debug_id);
555
556         memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
557
558         del_timer_sync(&call->timer);
559
560         ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
561         ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
562         ASSERTCMP(call->conn, ==, NULL);
563
564         /* Clean up the Rx/Tx buffer */
565         for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++)
566                 rxrpc_free_skb(call->rxtx_buffer[i],
567                                (call->tx_phase ? rxrpc_skb_tx_cleaned :
568                                 rxrpc_skb_rx_cleaned));
569
570         rxrpc_free_skb(call->tx_pending, rxrpc_skb_tx_cleaned);
571
572         call_rcu(&call->rcu, rxrpc_rcu_destroy_call);
573 }
574
575 /*
576  * Make sure that all calls are gone.
577  */
578 void __exit rxrpc_destroy_all_calls(void)
579 {
580         struct rxrpc_call *call;
581
582         _enter("");
583
584         if (list_empty(&rxrpc_calls))
585                 return;
586
587         write_lock(&rxrpc_call_lock);
588
589         while (!list_empty(&rxrpc_calls)) {
590                 call = list_entry(rxrpc_calls.next, struct rxrpc_call, link);
591                 _debug("Zapping call %p", call);
592
593                 rxrpc_see_call(call);
594                 list_del_init(&call->link);
595
596                 pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
597                        call, atomic_read(&call->usage),
598                        rxrpc_call_states[call->state],
599                        call->flags, call->events);
600
601                 write_unlock(&rxrpc_call_lock);
602                 cond_resched();
603                 write_lock(&rxrpc_call_lock);
604         }
605
606         write_unlock(&rxrpc_call_lock);
607 }