571a41fd5a324705a30e78304833b39c8c501380
[cascardo/linux.git] / net / rxrpc / ar-call.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 #include <linux/slab.h>
13 #include <linux/module.h>
14 #include <linux/circ_buf.h>
15 #include <linux/hashtable.h>
16 #include <linux/spinlock_types.h>
17 #include <net/sock.h>
18 #include <net/af_rxrpc.h>
19 #include "ar-internal.h"
20
21 /*
22  * Maximum lifetime of a call (in jiffies).
23  */
24 unsigned int rxrpc_max_call_lifetime = 60 * HZ;
25
26 /*
27  * Time till dead call expires after last use (in jiffies).
28  */
29 unsigned int rxrpc_dead_call_expiry = 2 * HZ;
30
31 const char *const rxrpc_call_states[NR__RXRPC_CALL_STATES] = {
32         [RXRPC_CALL_CLIENT_SEND_REQUEST]        = "ClSndReq",
33         [RXRPC_CALL_CLIENT_AWAIT_REPLY]         = "ClAwtRpl",
34         [RXRPC_CALL_CLIENT_RECV_REPLY]          = "ClRcvRpl",
35         [RXRPC_CALL_CLIENT_FINAL_ACK]           = "ClFnlACK",
36         [RXRPC_CALL_SERVER_SECURING]            = "SvSecure",
37         [RXRPC_CALL_SERVER_ACCEPTING]           = "SvAccept",
38         [RXRPC_CALL_SERVER_RECV_REQUEST]        = "SvRcvReq",
39         [RXRPC_CALL_SERVER_ACK_REQUEST]         = "SvAckReq",
40         [RXRPC_CALL_SERVER_SEND_REPLY]          = "SvSndRpl",
41         [RXRPC_CALL_SERVER_AWAIT_ACK]           = "SvAwtACK",
42         [RXRPC_CALL_COMPLETE]                   = "Complete",
43         [RXRPC_CALL_SERVER_BUSY]                = "SvBusy  ",
44         [RXRPC_CALL_REMOTELY_ABORTED]           = "RmtAbort",
45         [RXRPC_CALL_LOCALLY_ABORTED]            = "LocAbort",
46         [RXRPC_CALL_NETWORK_ERROR]              = "NetError",
47         [RXRPC_CALL_DEAD]                       = "Dead    ",
48 };
49
50 struct kmem_cache *rxrpc_call_jar;
51 LIST_HEAD(rxrpc_calls);
52 DEFINE_RWLOCK(rxrpc_call_lock);
53
54 static void rxrpc_destroy_call(struct work_struct *work);
55 static void rxrpc_call_life_expired(unsigned long _call);
56 static void rxrpc_dead_call_expired(unsigned long _call);
57 static void rxrpc_ack_time_expired(unsigned long _call);
58 static void rxrpc_resend_time_expired(unsigned long _call);
59
60 static DEFINE_SPINLOCK(rxrpc_call_hash_lock);
61 static DEFINE_HASHTABLE(rxrpc_call_hash, 10);
62
63 /*
64  * Hash function for rxrpc_call_hash
65  */
66 static unsigned long rxrpc_call_hashfunc(
67         u8              in_clientflag,
68         u32             cid,
69         u32             call_id,
70         u32             epoch,
71         u16             service_id,
72         sa_family_t     proto,
73         void            *localptr,
74         unsigned int    addr_size,
75         const u8        *peer_addr)
76 {
77         const u16 *p;
78         unsigned int i;
79         unsigned long key;
80
81         _enter("");
82
83         key = (unsigned long)localptr;
84         /* We just want to add up the __be32 values, so forcing the
85          * cast should be okay.
86          */
87         key += epoch;
88         key += service_id;
89         key += call_id;
90         key += (cid & RXRPC_CIDMASK) >> RXRPC_CIDSHIFT;
91         key += cid & RXRPC_CHANNELMASK;
92         key += in_clientflag;
93         key += proto;
94         /* Step through the peer address in 16-bit portions for speed */
95         for (i = 0, p = (const u16 *)peer_addr; i < addr_size >> 1; i++, p++)
96                 key += *p;
97         _leave(" key = 0x%lx", key);
98         return key;
99 }
100
101 /*
102  * Add a call to the hashtable
103  */
104 static void rxrpc_call_hash_add(struct rxrpc_call *call)
105 {
106         unsigned long key;
107         unsigned int addr_size = 0;
108
109         _enter("");
110         switch (call->proto) {
111         case AF_INET:
112                 addr_size = sizeof(call->peer_ip.ipv4_addr);
113                 break;
114         case AF_INET6:
115                 addr_size = sizeof(call->peer_ip.ipv6_addr);
116                 break;
117         default:
118                 break;
119         }
120         key = rxrpc_call_hashfunc(call->in_clientflag, call->cid,
121                                   call->call_id, call->epoch,
122                                   call->service_id, call->proto,
123                                   call->conn->trans->local, addr_size,
124                                   call->peer_ip.ipv6_addr);
125         /* Store the full key in the call */
126         call->hash_key = key;
127         spin_lock(&rxrpc_call_hash_lock);
128         hash_add_rcu(rxrpc_call_hash, &call->hash_node, key);
129         spin_unlock(&rxrpc_call_hash_lock);
130         _leave("");
131 }
132
133 /*
134  * Remove a call from the hashtable
135  */
136 static void rxrpc_call_hash_del(struct rxrpc_call *call)
137 {
138         _enter("");
139         spin_lock(&rxrpc_call_hash_lock);
140         hash_del_rcu(&call->hash_node);
141         spin_unlock(&rxrpc_call_hash_lock);
142         _leave("");
143 }
144
145 /*
146  * Find a call in the hashtable and return it, or NULL if it
147  * isn't there.
148  */
149 struct rxrpc_call *rxrpc_find_call_hash(
150         struct rxrpc_host_header *hdr,
151         void            *localptr,
152         sa_family_t     proto,
153         const void      *peer_addr)
154 {
155         unsigned long key;
156         unsigned int addr_size = 0;
157         struct rxrpc_call *call = NULL;
158         struct rxrpc_call *ret = NULL;
159         u8 in_clientflag = hdr->flags & RXRPC_CLIENT_INITIATED;
160
161         _enter("");
162         switch (proto) {
163         case AF_INET:
164                 addr_size = sizeof(call->peer_ip.ipv4_addr);
165                 break;
166         case AF_INET6:
167                 addr_size = sizeof(call->peer_ip.ipv6_addr);
168                 break;
169         default:
170                 break;
171         }
172
173         key = rxrpc_call_hashfunc(in_clientflag, hdr->cid, hdr->callNumber,
174                                   hdr->epoch, hdr->serviceId,
175                                   proto, localptr, addr_size,
176                                   peer_addr);
177         hash_for_each_possible_rcu(rxrpc_call_hash, call, hash_node, key) {
178                 if (call->hash_key == key &&
179                     call->call_id == hdr->callNumber &&
180                     call->cid == hdr->cid &&
181                     call->in_clientflag == in_clientflag &&
182                     call->service_id == hdr->serviceId &&
183                     call->proto == proto &&
184                     call->local == localptr &&
185                     memcmp(call->peer_ip.ipv6_addr, peer_addr,
186                            addr_size) == 0 &&
187                     call->epoch == hdr->epoch) {
188                         ret = call;
189                         break;
190                 }
191         }
192         _leave(" = %p", ret);
193         return ret;
194 }
195
196 /*
197  * allocate a new call
198  */
199 static struct rxrpc_call *rxrpc_alloc_call(gfp_t gfp)
200 {
201         struct rxrpc_call *call;
202
203         call = kmem_cache_zalloc(rxrpc_call_jar, gfp);
204         if (!call)
205                 return NULL;
206
207         call->acks_winsz = 16;
208         call->acks_window = kmalloc(call->acks_winsz * sizeof(unsigned long),
209                                     gfp);
210         if (!call->acks_window) {
211                 kmem_cache_free(rxrpc_call_jar, call);
212                 return NULL;
213         }
214
215         setup_timer(&call->lifetimer, &rxrpc_call_life_expired,
216                     (unsigned long) call);
217         setup_timer(&call->deadspan, &rxrpc_dead_call_expired,
218                     (unsigned long) call);
219         setup_timer(&call->ack_timer, &rxrpc_ack_time_expired,
220                     (unsigned long) call);
221         setup_timer(&call->resend_timer, &rxrpc_resend_time_expired,
222                     (unsigned long) call);
223         INIT_WORK(&call->destroyer, &rxrpc_destroy_call);
224         INIT_WORK(&call->processor, &rxrpc_process_call);
225         INIT_LIST_HEAD(&call->accept_link);
226         skb_queue_head_init(&call->rx_queue);
227         skb_queue_head_init(&call->rx_oos_queue);
228         init_waitqueue_head(&call->tx_waitq);
229         spin_lock_init(&call->lock);
230         rwlock_init(&call->state_lock);
231         atomic_set(&call->usage, 1);
232         call->debug_id = atomic_inc_return(&rxrpc_debug_id);
233         call->state = RXRPC_CALL_CLIENT_SEND_REQUEST;
234
235         memset(&call->sock_node, 0xed, sizeof(call->sock_node));
236
237         call->rx_data_expect = 1;
238         call->rx_data_eaten = 0;
239         call->rx_first_oos = 0;
240         call->ackr_win_top = call->rx_data_eaten + 1 + rxrpc_rx_window_size;
241         call->creation_jif = jiffies;
242         return call;
243 }
244
245 /*
246  * allocate a new client call and attempt to get a connection slot for it
247  */
248 static struct rxrpc_call *rxrpc_alloc_client_call(
249         struct rxrpc_sock *rx,
250         struct rxrpc_transport *trans,
251         struct rxrpc_conn_bundle *bundle,
252         gfp_t gfp)
253 {
254         struct rxrpc_call *call;
255         int ret;
256
257         _enter("");
258
259         ASSERT(rx != NULL);
260         ASSERT(trans != NULL);
261         ASSERT(bundle != NULL);
262
263         call = rxrpc_alloc_call(gfp);
264         if (!call)
265                 return ERR_PTR(-ENOMEM);
266
267         sock_hold(&rx->sk);
268         call->socket = rx;
269         call->rx_data_post = 1;
270
271         ret = rxrpc_connect_call(rx, trans, bundle, call, gfp);
272         if (ret < 0) {
273                 kmem_cache_free(rxrpc_call_jar, call);
274                 return ERR_PTR(ret);
275         }
276
277         /* Record copies of information for hashtable lookup */
278         call->proto = rx->proto;
279         call->local = trans->local;
280         switch (call->proto) {
281         case AF_INET:
282                 call->peer_ip.ipv4_addr =
283                         trans->peer->srx.transport.sin.sin_addr.s_addr;
284                 break;
285         case AF_INET6:
286                 memcpy(call->peer_ip.ipv6_addr,
287                        trans->peer->srx.transport.sin6.sin6_addr.in6_u.u6_addr8,
288                        sizeof(call->peer_ip.ipv6_addr));
289                 break;
290         }
291         call->epoch = call->conn->epoch;
292         call->service_id = call->conn->service_id;
293         call->in_clientflag = call->conn->in_clientflag;
294         /* Add the new call to the hashtable */
295         rxrpc_call_hash_add(call);
296
297         spin_lock(&call->conn->trans->peer->lock);
298         list_add(&call->error_link, &call->conn->trans->peer->error_targets);
299         spin_unlock(&call->conn->trans->peer->lock);
300
301         call->lifetimer.expires = jiffies + rxrpc_max_call_lifetime;
302         add_timer(&call->lifetimer);
303
304         _leave(" = %p", call);
305         return call;
306 }
307
308 /*
309  * set up a call for the given data
310  * - called in process context with IRQs enabled
311  */
312 struct rxrpc_call *rxrpc_get_client_call(struct rxrpc_sock *rx,
313                                          struct rxrpc_transport *trans,
314                                          struct rxrpc_conn_bundle *bundle,
315                                          unsigned long user_call_ID,
316                                          int create,
317                                          gfp_t gfp)
318 {
319         struct rxrpc_call *call, *candidate;
320         struct rb_node *p, *parent, **pp;
321
322         _enter("%p,%d,%d,%lx,%d",
323                rx, trans ? trans->debug_id : -1, bundle ? bundle->debug_id : -1,
324                user_call_ID, create);
325
326         /* search the extant calls first for one that matches the specified
327          * user ID */
328         read_lock(&rx->call_lock);
329
330         p = rx->calls.rb_node;
331         while (p) {
332                 call = rb_entry(p, struct rxrpc_call, sock_node);
333
334                 if (user_call_ID < call->user_call_ID)
335                         p = p->rb_left;
336                 else if (user_call_ID > call->user_call_ID)
337                         p = p->rb_right;
338                 else
339                         goto found_extant_call;
340         }
341
342         read_unlock(&rx->call_lock);
343
344         if (!create || !trans)
345                 return ERR_PTR(-EBADSLT);
346
347         /* not yet present - create a candidate for a new record and then
348          * redo the search */
349         candidate = rxrpc_alloc_client_call(rx, trans, bundle, gfp);
350         if (IS_ERR(candidate)) {
351                 _leave(" = %ld", PTR_ERR(candidate));
352                 return candidate;
353         }
354
355         candidate->user_call_ID = user_call_ID;
356         __set_bit(RXRPC_CALL_HAS_USERID, &candidate->flags);
357
358         write_lock(&rx->call_lock);
359
360         pp = &rx->calls.rb_node;
361         parent = NULL;
362         while (*pp) {
363                 parent = *pp;
364                 call = rb_entry(parent, struct rxrpc_call, sock_node);
365
366                 if (user_call_ID < call->user_call_ID)
367                         pp = &(*pp)->rb_left;
368                 else if (user_call_ID > call->user_call_ID)
369                         pp = &(*pp)->rb_right;
370                 else
371                         goto found_extant_second;
372         }
373
374         /* second search also failed; add the new call */
375         call = candidate;
376         candidate = NULL;
377         rxrpc_get_call(call);
378
379         rb_link_node(&call->sock_node, parent, pp);
380         rb_insert_color(&call->sock_node, &rx->calls);
381         write_unlock(&rx->call_lock);
382
383         write_lock_bh(&rxrpc_call_lock);
384         list_add_tail(&call->link, &rxrpc_calls);
385         write_unlock_bh(&rxrpc_call_lock);
386
387         _net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id);
388
389         _leave(" = %p [new]", call);
390         return call;
391
392         /* we found the call in the list immediately */
393 found_extant_call:
394         rxrpc_get_call(call);
395         read_unlock(&rx->call_lock);
396         _leave(" = %p [extant %d]", call, atomic_read(&call->usage));
397         return call;
398
399         /* we found the call on the second time through the list */
400 found_extant_second:
401         rxrpc_get_call(call);
402         write_unlock(&rx->call_lock);
403         rxrpc_put_call(candidate);
404         _leave(" = %p [second %d]", call, atomic_read(&call->usage));
405         return call;
406 }
407
408 /*
409  * set up an incoming call
410  * - called in process context with IRQs enabled
411  */
412 struct rxrpc_call *rxrpc_incoming_call(struct rxrpc_sock *rx,
413                                        struct rxrpc_connection *conn,
414                                        struct rxrpc_host_header *hdr)
415 {
416         struct rxrpc_call *call, *candidate;
417         struct rb_node **p, *parent;
418         u32 call_id;
419
420         _enter(",%d", conn->debug_id);
421
422         ASSERT(rx != NULL);
423
424         candidate = rxrpc_alloc_call(GFP_NOIO);
425         if (!candidate)
426                 return ERR_PTR(-EBUSY);
427
428         candidate->socket = rx;
429         candidate->conn = conn;
430         candidate->cid = hdr->cid;
431         candidate->call_id = hdr->callNumber;
432         candidate->channel = hdr->cid & RXRPC_CHANNELMASK;
433         candidate->rx_data_post = 0;
434         candidate->state = RXRPC_CALL_SERVER_ACCEPTING;
435         if (conn->security_ix > 0)
436                 candidate->state = RXRPC_CALL_SERVER_SECURING;
437
438         write_lock_bh(&conn->lock);
439
440         /* set the channel for this call */
441         call = conn->channels[candidate->channel];
442         _debug("channel[%u] is %p", candidate->channel, call);
443         if (call && call->call_id == hdr->callNumber) {
444                 /* already set; must've been a duplicate packet */
445                 _debug("extant call [%d]", call->state);
446                 ASSERTCMP(call->conn, ==, conn);
447
448                 read_lock(&call->state_lock);
449                 switch (call->state) {
450                 case RXRPC_CALL_LOCALLY_ABORTED:
451                         if (!test_and_set_bit(RXRPC_CALL_EV_ABORT, &call->events))
452                                 rxrpc_queue_call(call);
453                 case RXRPC_CALL_REMOTELY_ABORTED:
454                         read_unlock(&call->state_lock);
455                         goto aborted_call;
456                 default:
457                         rxrpc_get_call(call);
458                         read_unlock(&call->state_lock);
459                         goto extant_call;
460                 }
461         }
462
463         if (call) {
464                 /* it seems the channel is still in use from the previous call
465                  * - ditch the old binding if its call is now complete */
466                 _debug("CALL: %u { %s }",
467                        call->debug_id, rxrpc_call_states[call->state]);
468
469                 if (call->state >= RXRPC_CALL_COMPLETE) {
470                         conn->channels[call->channel] = NULL;
471                 } else {
472                         write_unlock_bh(&conn->lock);
473                         kmem_cache_free(rxrpc_call_jar, candidate);
474                         _leave(" = -EBUSY");
475                         return ERR_PTR(-EBUSY);
476                 }
477         }
478
479         /* check the call number isn't duplicate */
480         _debug("check dup");
481         call_id = hdr->callNumber;
482         p = &conn->calls.rb_node;
483         parent = NULL;
484         while (*p) {
485                 parent = *p;
486                 call = rb_entry(parent, struct rxrpc_call, conn_node);
487
488                 /* The tree is sorted in order of the __be32 value without
489                  * turning it into host order.
490                  */
491                 if (call_id < call->call_id)
492                         p = &(*p)->rb_left;
493                 else if (call_id > call->call_id)
494                         p = &(*p)->rb_right;
495                 else
496                         goto old_call;
497         }
498
499         /* make the call available */
500         _debug("new call");
501         call = candidate;
502         candidate = NULL;
503         rb_link_node(&call->conn_node, parent, p);
504         rb_insert_color(&call->conn_node, &conn->calls);
505         conn->channels[call->channel] = call;
506         sock_hold(&rx->sk);
507         atomic_inc(&conn->usage);
508         write_unlock_bh(&conn->lock);
509
510         spin_lock(&conn->trans->peer->lock);
511         list_add(&call->error_link, &conn->trans->peer->error_targets);
512         spin_unlock(&conn->trans->peer->lock);
513
514         write_lock_bh(&rxrpc_call_lock);
515         list_add_tail(&call->link, &rxrpc_calls);
516         write_unlock_bh(&rxrpc_call_lock);
517
518         /* Record copies of information for hashtable lookup */
519         call->proto = rx->proto;
520         call->local = conn->trans->local;
521         switch (call->proto) {
522         case AF_INET:
523                 call->peer_ip.ipv4_addr =
524                         conn->trans->peer->srx.transport.sin.sin_addr.s_addr;
525                 break;
526         case AF_INET6:
527                 memcpy(call->peer_ip.ipv6_addr,
528                        conn->trans->peer->srx.transport.sin6.sin6_addr.in6_u.u6_addr8,
529                        sizeof(call->peer_ip.ipv6_addr));
530                 break;
531         default:
532                 break;
533         }
534         call->epoch = conn->epoch;
535         call->service_id = conn->service_id;
536         call->in_clientflag = conn->in_clientflag;
537         /* Add the new call to the hashtable */
538         rxrpc_call_hash_add(call);
539
540         _net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id);
541
542         call->lifetimer.expires = jiffies + rxrpc_max_call_lifetime;
543         add_timer(&call->lifetimer);
544         _leave(" = %p {%d} [new]", call, call->debug_id);
545         return call;
546
547 extant_call:
548         write_unlock_bh(&conn->lock);
549         kmem_cache_free(rxrpc_call_jar, candidate);
550         _leave(" = %p {%d} [extant]", call, call ? call->debug_id : -1);
551         return call;
552
553 aborted_call:
554         write_unlock_bh(&conn->lock);
555         kmem_cache_free(rxrpc_call_jar, candidate);
556         _leave(" = -ECONNABORTED");
557         return ERR_PTR(-ECONNABORTED);
558
559 old_call:
560         write_unlock_bh(&conn->lock);
561         kmem_cache_free(rxrpc_call_jar, candidate);
562         _leave(" = -ECONNRESET [old]");
563         return ERR_PTR(-ECONNRESET);
564 }
565
566 /*
567  * find an extant server call
568  * - called in process context with IRQs enabled
569  */
570 struct rxrpc_call *rxrpc_find_server_call(struct rxrpc_sock *rx,
571                                           unsigned long user_call_ID)
572 {
573         struct rxrpc_call *call;
574         struct rb_node *p;
575
576         _enter("%p,%lx", rx, user_call_ID);
577
578         /* search the extant calls for one that matches the specified user
579          * ID */
580         read_lock(&rx->call_lock);
581
582         p = rx->calls.rb_node;
583         while (p) {
584                 call = rb_entry(p, struct rxrpc_call, sock_node);
585
586                 if (user_call_ID < call->user_call_ID)
587                         p = p->rb_left;
588                 else if (user_call_ID > call->user_call_ID)
589                         p = p->rb_right;
590                 else
591                         goto found_extant_call;
592         }
593
594         read_unlock(&rx->call_lock);
595         _leave(" = NULL");
596         return NULL;
597
598         /* we found the call in the list immediately */
599 found_extant_call:
600         rxrpc_get_call(call);
601         read_unlock(&rx->call_lock);
602         _leave(" = %p [%d]", call, atomic_read(&call->usage));
603         return call;
604 }
605
606 /*
607  * detach a call from a socket and set up for release
608  */
609 void rxrpc_release_call(struct rxrpc_call *call)
610 {
611         struct rxrpc_connection *conn = call->conn;
612         struct rxrpc_sock *rx = call->socket;
613
614         _enter("{%d,%d,%d,%d}",
615                call->debug_id, atomic_read(&call->usage),
616                atomic_read(&call->ackr_not_idle),
617                call->rx_first_oos);
618
619         spin_lock_bh(&call->lock);
620         if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
621                 BUG();
622         spin_unlock_bh(&call->lock);
623
624         /* dissociate from the socket
625          * - the socket's ref on the call is passed to the death timer
626          */
627         _debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
628
629         write_lock_bh(&rx->call_lock);
630         if (!list_empty(&call->accept_link)) {
631                 _debug("unlinking once-pending call %p { e=%lx f=%lx }",
632                        call, call->events, call->flags);
633                 ASSERT(!test_bit(RXRPC_CALL_HAS_USERID, &call->flags));
634                 list_del_init(&call->accept_link);
635                 sk_acceptq_removed(&rx->sk);
636         } else if (test_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
637                 rb_erase(&call->sock_node, &rx->calls);
638                 memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
639                 clear_bit(RXRPC_CALL_HAS_USERID, &call->flags);
640         }
641         write_unlock_bh(&rx->call_lock);
642
643         /* free up the channel for reuse */
644         spin_lock(&conn->trans->client_lock);
645         write_lock_bh(&conn->lock);
646         write_lock(&call->state_lock);
647
648         if (conn->channels[call->channel] == call)
649                 conn->channels[call->channel] = NULL;
650
651         if (conn->out_clientflag && conn->bundle) {
652                 conn->avail_calls++;
653                 switch (conn->avail_calls) {
654                 case 1:
655                         list_move_tail(&conn->bundle_link,
656                                        &conn->bundle->avail_conns);
657                 case 2 ... RXRPC_MAXCALLS - 1:
658                         ASSERT(conn->channels[0] == NULL ||
659                                conn->channels[1] == NULL ||
660                                conn->channels[2] == NULL ||
661                                conn->channels[3] == NULL);
662                         break;
663                 case RXRPC_MAXCALLS:
664                         list_move_tail(&conn->bundle_link,
665                                        &conn->bundle->unused_conns);
666                         ASSERT(conn->channels[0] == NULL &&
667                                conn->channels[1] == NULL &&
668                                conn->channels[2] == NULL &&
669                                conn->channels[3] == NULL);
670                         break;
671                 default:
672                         printk(KERN_ERR "RxRPC: conn->avail_calls=%d\n",
673                                conn->avail_calls);
674                         BUG();
675                 }
676         }
677
678         spin_unlock(&conn->trans->client_lock);
679
680         if (call->state < RXRPC_CALL_COMPLETE &&
681             call->state != RXRPC_CALL_CLIENT_FINAL_ACK) {
682                 _debug("+++ ABORTING STATE %d +++\n", call->state);
683                 call->state = RXRPC_CALL_LOCALLY_ABORTED;
684                 call->local_abort = RX_CALL_DEAD;
685                 set_bit(RXRPC_CALL_EV_ABORT, &call->events);
686                 rxrpc_queue_call(call);
687         }
688         write_unlock(&call->state_lock);
689         write_unlock_bh(&conn->lock);
690
691         /* clean up the Rx queue */
692         if (!skb_queue_empty(&call->rx_queue) ||
693             !skb_queue_empty(&call->rx_oos_queue)) {
694                 struct rxrpc_skb_priv *sp;
695                 struct sk_buff *skb;
696
697                 _debug("purge Rx queues");
698
699                 spin_lock_bh(&call->lock);
700                 while ((skb = skb_dequeue(&call->rx_queue)) ||
701                        (skb = skb_dequeue(&call->rx_oos_queue))) {
702                         sp = rxrpc_skb(skb);
703                         if (sp->call) {
704                                 ASSERTCMP(sp->call, ==, call);
705                                 rxrpc_put_call(call);
706                                 sp->call = NULL;
707                         }
708                         skb->destructor = NULL;
709                         spin_unlock_bh(&call->lock);
710
711                         _debug("- zap %s %%%u #%u",
712                                rxrpc_pkts[sp->hdr.type],
713                                sp->hdr.serial, sp->hdr.seq);
714                         rxrpc_free_skb(skb);
715                         spin_lock_bh(&call->lock);
716                 }
717                 spin_unlock_bh(&call->lock);
718
719                 ASSERTCMP(call->state, !=, RXRPC_CALL_COMPLETE);
720         }
721
722         del_timer_sync(&call->resend_timer);
723         del_timer_sync(&call->ack_timer);
724         del_timer_sync(&call->lifetimer);
725         call->deadspan.expires = jiffies + rxrpc_dead_call_expiry;
726         add_timer(&call->deadspan);
727
728         _leave("");
729 }
730
731 /*
732  * handle a dead call being ready for reaping
733  */
734 static void rxrpc_dead_call_expired(unsigned long _call)
735 {
736         struct rxrpc_call *call = (struct rxrpc_call *) _call;
737
738         _enter("{%d}", call->debug_id);
739
740         write_lock_bh(&call->state_lock);
741         call->state = RXRPC_CALL_DEAD;
742         write_unlock_bh(&call->state_lock);
743         rxrpc_put_call(call);
744 }
745
746 /*
747  * mark a call as to be released, aborting it if it's still in progress
748  * - called with softirqs disabled
749  */
750 static void rxrpc_mark_call_released(struct rxrpc_call *call)
751 {
752         bool sched;
753
754         write_lock(&call->state_lock);
755         if (call->state < RXRPC_CALL_DEAD) {
756                 sched = false;
757                 if (call->state < RXRPC_CALL_COMPLETE) {
758                         _debug("abort call %p", call);
759                         call->state = RXRPC_CALL_LOCALLY_ABORTED;
760                         call->local_abort = RX_CALL_DEAD;
761                         if (!test_and_set_bit(RXRPC_CALL_EV_ABORT, &call->events))
762                                 sched = true;
763                 }
764                 if (!test_and_set_bit(RXRPC_CALL_EV_RELEASE, &call->events))
765                         sched = true;
766                 if (sched)
767                         rxrpc_queue_call(call);
768         }
769         write_unlock(&call->state_lock);
770 }
771
772 /*
773  * release all the calls associated with a socket
774  */
775 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
776 {
777         struct rxrpc_call *call;
778         struct rb_node *p;
779
780         _enter("%p", rx);
781
782         read_lock_bh(&rx->call_lock);
783
784         /* mark all the calls as no longer wanting incoming packets */
785         for (p = rb_first(&rx->calls); p; p = rb_next(p)) {
786                 call = rb_entry(p, struct rxrpc_call, sock_node);
787                 rxrpc_mark_call_released(call);
788         }
789
790         /* kill the not-yet-accepted incoming calls */
791         list_for_each_entry(call, &rx->secureq, accept_link) {
792                 rxrpc_mark_call_released(call);
793         }
794
795         list_for_each_entry(call, &rx->acceptq, accept_link) {
796                 rxrpc_mark_call_released(call);
797         }
798
799         read_unlock_bh(&rx->call_lock);
800         _leave("");
801 }
802
803 /*
804  * release a call
805  */
806 void __rxrpc_put_call(struct rxrpc_call *call)
807 {
808         ASSERT(call != NULL);
809
810         _enter("%p{u=%d}", call, atomic_read(&call->usage));
811
812         ASSERTCMP(atomic_read(&call->usage), >, 0);
813
814         if (atomic_dec_and_test(&call->usage)) {
815                 _debug("call %d dead", call->debug_id);
816                 ASSERTCMP(call->state, ==, RXRPC_CALL_DEAD);
817                 rxrpc_queue_work(&call->destroyer);
818         }
819         _leave("");
820 }
821
822 /*
823  * clean up a call
824  */
825 static void rxrpc_cleanup_call(struct rxrpc_call *call)
826 {
827         _net("DESTROY CALL %d", call->debug_id);
828
829         ASSERT(call->socket);
830
831         memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
832
833         del_timer_sync(&call->lifetimer);
834         del_timer_sync(&call->deadspan);
835         del_timer_sync(&call->ack_timer);
836         del_timer_sync(&call->resend_timer);
837
838         ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
839         ASSERTCMP(call->events, ==, 0);
840         if (work_pending(&call->processor)) {
841                 _debug("defer destroy");
842                 rxrpc_queue_work(&call->destroyer);
843                 return;
844         }
845
846         if (call->conn) {
847                 spin_lock(&call->conn->trans->peer->lock);
848                 list_del(&call->error_link);
849                 spin_unlock(&call->conn->trans->peer->lock);
850
851                 write_lock_bh(&call->conn->lock);
852                 rb_erase(&call->conn_node, &call->conn->calls);
853                 write_unlock_bh(&call->conn->lock);
854                 rxrpc_put_connection(call->conn);
855         }
856
857         /* Remove the call from the hash */
858         rxrpc_call_hash_del(call);
859
860         if (call->acks_window) {
861                 _debug("kill Tx window %d",
862                        CIRC_CNT(call->acks_head, call->acks_tail,
863                                 call->acks_winsz));
864                 smp_mb();
865                 while (CIRC_CNT(call->acks_head, call->acks_tail,
866                                 call->acks_winsz) > 0) {
867                         struct rxrpc_skb_priv *sp;
868                         unsigned long _skb;
869
870                         _skb = call->acks_window[call->acks_tail] & ~1;
871                         sp = rxrpc_skb((struct sk_buff *)_skb);
872                         _debug("+++ clear Tx %u", sp->hdr.seq);
873                         rxrpc_free_skb((struct sk_buff *)_skb);
874                         call->acks_tail =
875                                 (call->acks_tail + 1) & (call->acks_winsz - 1);
876                 }
877
878                 kfree(call->acks_window);
879         }
880
881         rxrpc_free_skb(call->tx_pending);
882
883         rxrpc_purge_queue(&call->rx_queue);
884         ASSERT(skb_queue_empty(&call->rx_oos_queue));
885         sock_put(&call->socket->sk);
886         kmem_cache_free(rxrpc_call_jar, call);
887 }
888
889 /*
890  * destroy a call
891  */
892 static void rxrpc_destroy_call(struct work_struct *work)
893 {
894         struct rxrpc_call *call =
895                 container_of(work, struct rxrpc_call, destroyer);
896
897         _enter("%p{%d,%d,%p}",
898                call, atomic_read(&call->usage), call->channel, call->conn);
899
900         ASSERTCMP(call->state, ==, RXRPC_CALL_DEAD);
901
902         write_lock_bh(&rxrpc_call_lock);
903         list_del_init(&call->link);
904         write_unlock_bh(&rxrpc_call_lock);
905
906         rxrpc_cleanup_call(call);
907         _leave("");
908 }
909
910 /*
911  * preemptively destroy all the call records from a transport endpoint rather
912  * than waiting for them to time out
913  */
914 void __exit rxrpc_destroy_all_calls(void)
915 {
916         struct rxrpc_call *call;
917
918         _enter("");
919         write_lock_bh(&rxrpc_call_lock);
920
921         while (!list_empty(&rxrpc_calls)) {
922                 call = list_entry(rxrpc_calls.next, struct rxrpc_call, link);
923                 _debug("Zapping call %p", call);
924
925                 list_del_init(&call->link);
926
927                 switch (atomic_read(&call->usage)) {
928                 case 0:
929                         ASSERTCMP(call->state, ==, RXRPC_CALL_DEAD);
930                         break;
931                 case 1:
932                         if (del_timer_sync(&call->deadspan) != 0 &&
933                             call->state != RXRPC_CALL_DEAD)
934                                 rxrpc_dead_call_expired((unsigned long) call);
935                         if (call->state != RXRPC_CALL_DEAD)
936                                 break;
937                 default:
938                         printk(KERN_ERR "RXRPC:"
939                                " Call %p still in use (%d,%d,%s,%lx,%lx)!\n",
940                                call, atomic_read(&call->usage),
941                                atomic_read(&call->ackr_not_idle),
942                                rxrpc_call_states[call->state],
943                                call->flags, call->events);
944                         if (!skb_queue_empty(&call->rx_queue))
945                                 printk(KERN_ERR"RXRPC: Rx queue occupied\n");
946                         if (!skb_queue_empty(&call->rx_oos_queue))
947                                 printk(KERN_ERR"RXRPC: OOS queue occupied\n");
948                         break;
949                 }
950
951                 write_unlock_bh(&rxrpc_call_lock);
952                 cond_resched();
953                 write_lock_bh(&rxrpc_call_lock);
954         }
955
956         write_unlock_bh(&rxrpc_call_lock);
957         _leave("");
958 }
959
960 /*
961  * handle call lifetime being exceeded
962  */
963 static void rxrpc_call_life_expired(unsigned long _call)
964 {
965         struct rxrpc_call *call = (struct rxrpc_call *) _call;
966
967         if (call->state >= RXRPC_CALL_COMPLETE)
968                 return;
969
970         _enter("{%d}", call->debug_id);
971         read_lock_bh(&call->state_lock);
972         if (call->state < RXRPC_CALL_COMPLETE) {
973                 set_bit(RXRPC_CALL_EV_LIFE_TIMER, &call->events);
974                 rxrpc_queue_call(call);
975         }
976         read_unlock_bh(&call->state_lock);
977 }
978
979 /*
980  * handle resend timer expiry
981  * - may not take call->state_lock as this can deadlock against del_timer_sync()
982  */
983 static void rxrpc_resend_time_expired(unsigned long _call)
984 {
985         struct rxrpc_call *call = (struct rxrpc_call *) _call;
986
987         _enter("{%d}", call->debug_id);
988
989         if (call->state >= RXRPC_CALL_COMPLETE)
990                 return;
991
992         clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
993         if (!test_and_set_bit(RXRPC_CALL_EV_RESEND_TIMER, &call->events))
994                 rxrpc_queue_call(call);
995 }
996
997 /*
998  * handle ACK timer expiry
999  */
1000 static void rxrpc_ack_time_expired(unsigned long _call)
1001 {
1002         struct rxrpc_call *call = (struct rxrpc_call *) _call;
1003
1004         _enter("{%d}", call->debug_id);
1005
1006         if (call->state >= RXRPC_CALL_COMPLETE)
1007                 return;
1008
1009         read_lock_bh(&call->state_lock);
1010         if (call->state < RXRPC_CALL_COMPLETE &&
1011             !test_and_set_bit(RXRPC_CALL_EV_ACK, &call->events))
1012                 rxrpc_queue_call(call);
1013         read_unlock_bh(&call->state_lock);
1014 }