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17926a79 DH |
1 | /* RxRPC virtual connection handler |
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/module.h> | |
13 | #include <linux/net.h> | |
14 | #include <linux/skbuff.h> | |
15 | #include <linux/crypto.h> | |
16 | #include <net/sock.h> | |
17 | #include <net/af_rxrpc.h> | |
18 | #include "ar-internal.h" | |
19 | ||
20 | static void rxrpc_connection_reaper(struct work_struct *work); | |
21 | ||
22 | LIST_HEAD(rxrpc_connections); | |
23 | DEFINE_RWLOCK(rxrpc_connection_lock); | |
24 | static unsigned long rxrpc_connection_timeout = 10 * 60; | |
25 | static DECLARE_DELAYED_WORK(rxrpc_connection_reap, rxrpc_connection_reaper); | |
26 | ||
27 | /* | |
28 | * allocate a new client connection bundle | |
29 | */ | |
30 | static struct rxrpc_conn_bundle *rxrpc_alloc_bundle(gfp_t gfp) | |
31 | { | |
32 | struct rxrpc_conn_bundle *bundle; | |
33 | ||
34 | _enter(""); | |
35 | ||
36 | bundle = kzalloc(sizeof(struct rxrpc_conn_bundle), gfp); | |
37 | if (bundle) { | |
38 | INIT_LIST_HEAD(&bundle->unused_conns); | |
39 | INIT_LIST_HEAD(&bundle->avail_conns); | |
40 | INIT_LIST_HEAD(&bundle->busy_conns); | |
41 | init_waitqueue_head(&bundle->chanwait); | |
42 | atomic_set(&bundle->usage, 1); | |
43 | } | |
44 | ||
45 | _leave(" = %p", bundle); | |
46 | return bundle; | |
47 | } | |
48 | ||
49 | /* | |
50 | * compare bundle parameters with what we're looking for | |
51 | * - return -ve, 0 or +ve | |
52 | */ | |
53 | static inline | |
54 | int rxrpc_cmp_bundle(const struct rxrpc_conn_bundle *bundle, | |
55 | struct key *key, __be16 service_id) | |
56 | { | |
57 | return (bundle->service_id - service_id) ?: | |
58 | ((unsigned long) bundle->key - (unsigned long) key); | |
59 | } | |
60 | ||
61 | /* | |
62 | * get bundle of client connections that a client socket can make use of | |
63 | */ | |
64 | struct rxrpc_conn_bundle *rxrpc_get_bundle(struct rxrpc_sock *rx, | |
65 | struct rxrpc_transport *trans, | |
66 | struct key *key, | |
67 | __be16 service_id, | |
68 | gfp_t gfp) | |
69 | { | |
70 | struct rxrpc_conn_bundle *bundle, *candidate; | |
71 | struct rb_node *p, *parent, **pp; | |
72 | ||
73 | _enter("%p{%x},%x,%hx,", | |
74 | rx, key_serial(key), trans->debug_id, ntohl(service_id)); | |
75 | ||
76 | if (rx->trans == trans && rx->bundle) { | |
77 | atomic_inc(&rx->bundle->usage); | |
78 | return rx->bundle; | |
79 | } | |
80 | ||
81 | /* search the extant bundles first for one that matches the specified | |
82 | * user ID */ | |
83 | spin_lock(&trans->client_lock); | |
84 | ||
85 | p = trans->bundles.rb_node; | |
86 | while (p) { | |
87 | bundle = rb_entry(p, struct rxrpc_conn_bundle, node); | |
88 | ||
89 | if (rxrpc_cmp_bundle(bundle, key, service_id) < 0) | |
90 | p = p->rb_left; | |
91 | else if (rxrpc_cmp_bundle(bundle, key, service_id) > 0) | |
92 | p = p->rb_right; | |
93 | else | |
94 | goto found_extant_bundle; | |
95 | } | |
96 | ||
97 | spin_unlock(&trans->client_lock); | |
98 | ||
99 | /* not yet present - create a candidate for a new record and then | |
100 | * redo the search */ | |
101 | candidate = rxrpc_alloc_bundle(gfp); | |
102 | if (!candidate) { | |
103 | _leave(" = -ENOMEM"); | |
104 | return ERR_PTR(-ENOMEM); | |
105 | } | |
106 | ||
107 | candidate->key = key_get(key); | |
108 | candidate->service_id = service_id; | |
109 | ||
110 | spin_lock(&trans->client_lock); | |
111 | ||
112 | pp = &trans->bundles.rb_node; | |
113 | parent = NULL; | |
114 | while (*pp) { | |
115 | parent = *pp; | |
116 | bundle = rb_entry(parent, struct rxrpc_conn_bundle, node); | |
117 | ||
118 | if (rxrpc_cmp_bundle(bundle, key, service_id) < 0) | |
119 | pp = &(*pp)->rb_left; | |
120 | else if (rxrpc_cmp_bundle(bundle, key, service_id) > 0) | |
121 | pp = &(*pp)->rb_right; | |
122 | else | |
123 | goto found_extant_second; | |
124 | } | |
125 | ||
126 | /* second search also failed; add the new bundle */ | |
127 | bundle = candidate; | |
128 | candidate = NULL; | |
129 | ||
130 | rb_link_node(&bundle->node, parent, pp); | |
131 | rb_insert_color(&bundle->node, &trans->bundles); | |
132 | spin_unlock(&trans->client_lock); | |
133 | _net("BUNDLE new on trans %d", trans->debug_id); | |
134 | if (!rx->bundle && rx->sk.sk_state == RXRPC_CLIENT_CONNECTED) { | |
135 | atomic_inc(&bundle->usage); | |
136 | rx->bundle = bundle; | |
137 | } | |
138 | _leave(" = %p [new]", bundle); | |
139 | return bundle; | |
140 | ||
141 | /* we found the bundle in the list immediately */ | |
142 | found_extant_bundle: | |
143 | atomic_inc(&bundle->usage); | |
144 | spin_unlock(&trans->client_lock); | |
145 | _net("BUNDLE old on trans %d", trans->debug_id); | |
146 | if (!rx->bundle && rx->sk.sk_state == RXRPC_CLIENT_CONNECTED) { | |
147 | atomic_inc(&bundle->usage); | |
148 | rx->bundle = bundle; | |
149 | } | |
150 | _leave(" = %p [extant %d]", bundle, atomic_read(&bundle->usage)); | |
151 | return bundle; | |
152 | ||
153 | /* we found the bundle on the second time through the list */ | |
154 | found_extant_second: | |
155 | atomic_inc(&bundle->usage); | |
156 | spin_unlock(&trans->client_lock); | |
157 | kfree(candidate); | |
158 | _net("BUNDLE old2 on trans %d", trans->debug_id); | |
159 | if (!rx->bundle && rx->sk.sk_state == RXRPC_CLIENT_CONNECTED) { | |
160 | atomic_inc(&bundle->usage); | |
161 | rx->bundle = bundle; | |
162 | } | |
163 | _leave(" = %p [second %d]", bundle, atomic_read(&bundle->usage)); | |
164 | return bundle; | |
165 | } | |
166 | ||
167 | /* | |
168 | * release a bundle | |
169 | */ | |
170 | void rxrpc_put_bundle(struct rxrpc_transport *trans, | |
171 | struct rxrpc_conn_bundle *bundle) | |
172 | { | |
173 | _enter("%p,%p{%d}",trans, bundle, atomic_read(&bundle->usage)); | |
174 | ||
175 | if (atomic_dec_and_lock(&bundle->usage, &trans->client_lock)) { | |
176 | _debug("Destroy bundle"); | |
177 | rb_erase(&bundle->node, &trans->bundles); | |
178 | spin_unlock(&trans->client_lock); | |
179 | ASSERT(list_empty(&bundle->unused_conns)); | |
180 | ASSERT(list_empty(&bundle->avail_conns)); | |
181 | ASSERT(list_empty(&bundle->busy_conns)); | |
182 | ASSERTCMP(bundle->num_conns, ==, 0); | |
183 | key_put(bundle->key); | |
184 | kfree(bundle); | |
185 | } | |
186 | ||
187 | _leave(""); | |
188 | } | |
189 | ||
190 | /* | |
191 | * allocate a new connection | |
192 | */ | |
193 | static struct rxrpc_connection *rxrpc_alloc_connection(gfp_t gfp) | |
194 | { | |
195 | struct rxrpc_connection *conn; | |
196 | ||
197 | _enter(""); | |
198 | ||
199 | conn = kzalloc(sizeof(struct rxrpc_connection), gfp); | |
200 | if (conn) { | |
201 | INIT_WORK(&conn->processor, &rxrpc_process_connection); | |
202 | INIT_LIST_HEAD(&conn->bundle_link); | |
203 | conn->calls = RB_ROOT; | |
204 | skb_queue_head_init(&conn->rx_queue); | |
205 | rwlock_init(&conn->lock); | |
206 | spin_lock_init(&conn->state_lock); | |
207 | atomic_set(&conn->usage, 1); | |
208 | conn->debug_id = atomic_inc_return(&rxrpc_debug_id); | |
209 | conn->avail_calls = RXRPC_MAXCALLS; | |
210 | conn->size_align = 4; | |
211 | conn->header_size = sizeof(struct rxrpc_header); | |
212 | } | |
213 | ||
214 | _leave(" = %p{%d}", conn, conn->debug_id); | |
215 | return conn; | |
216 | } | |
217 | ||
218 | /* | |
219 | * assign a connection ID to a connection and add it to the transport's | |
220 | * connection lookup tree | |
221 | * - called with transport client lock held | |
222 | */ | |
223 | static void rxrpc_assign_connection_id(struct rxrpc_connection *conn) | |
224 | { | |
225 | struct rxrpc_connection *xconn; | |
226 | struct rb_node *parent, **p; | |
227 | __be32 epoch; | |
228 | u32 real_conn_id; | |
229 | ||
230 | _enter(""); | |
231 | ||
232 | epoch = conn->epoch; | |
233 | ||
234 | write_lock_bh(&conn->trans->conn_lock); | |
235 | ||
236 | conn->trans->conn_idcounter += RXRPC_CID_INC; | |
237 | if (conn->trans->conn_idcounter < RXRPC_CID_INC) | |
238 | conn->trans->conn_idcounter = RXRPC_CID_INC; | |
239 | real_conn_id = conn->trans->conn_idcounter; | |
240 | ||
241 | attempt_insertion: | |
242 | parent = NULL; | |
243 | p = &conn->trans->client_conns.rb_node; | |
244 | ||
245 | while (*p) { | |
246 | parent = *p; | |
247 | xconn = rb_entry(parent, struct rxrpc_connection, node); | |
248 | ||
249 | if (epoch < xconn->epoch) | |
250 | p = &(*p)->rb_left; | |
251 | else if (epoch > xconn->epoch) | |
252 | p = &(*p)->rb_right; | |
253 | else if (real_conn_id < xconn->real_conn_id) | |
254 | p = &(*p)->rb_left; | |
255 | else if (real_conn_id > xconn->real_conn_id) | |
256 | p = &(*p)->rb_right; | |
257 | else | |
258 | goto id_exists; | |
259 | } | |
260 | ||
261 | /* we've found a suitable hole - arrange for this connection to occupy | |
262 | * it */ | |
263 | rb_link_node(&conn->node, parent, p); | |
264 | rb_insert_color(&conn->node, &conn->trans->client_conns); | |
265 | ||
266 | conn->real_conn_id = real_conn_id; | |
267 | conn->cid = htonl(real_conn_id); | |
268 | write_unlock_bh(&conn->trans->conn_lock); | |
269 | _leave(" [CONNID %x CID %x]", real_conn_id, ntohl(conn->cid)); | |
270 | return; | |
271 | ||
272 | /* we found a connection with the proposed ID - walk the tree from that | |
273 | * point looking for the next unused ID */ | |
274 | id_exists: | |
275 | for (;;) { | |
276 | real_conn_id += RXRPC_CID_INC; | |
277 | if (real_conn_id < RXRPC_CID_INC) { | |
278 | real_conn_id = RXRPC_CID_INC; | |
279 | conn->trans->conn_idcounter = real_conn_id; | |
280 | goto attempt_insertion; | |
281 | } | |
282 | ||
283 | parent = rb_next(parent); | |
284 | if (!parent) | |
285 | goto attempt_insertion; | |
286 | ||
287 | xconn = rb_entry(parent, struct rxrpc_connection, node); | |
288 | if (epoch < xconn->epoch || | |
289 | real_conn_id < xconn->real_conn_id) | |
290 | goto attempt_insertion; | |
291 | } | |
292 | } | |
293 | ||
294 | /* | |
295 | * add a call to a connection's call-by-ID tree | |
296 | */ | |
297 | static void rxrpc_add_call_ID_to_conn(struct rxrpc_connection *conn, | |
298 | struct rxrpc_call *call) | |
299 | { | |
300 | struct rxrpc_call *xcall; | |
301 | struct rb_node *parent, **p; | |
302 | __be32 call_id; | |
303 | ||
304 | write_lock_bh(&conn->lock); | |
305 | ||
306 | call_id = call->call_id; | |
307 | p = &conn->calls.rb_node; | |
308 | parent = NULL; | |
309 | while (*p) { | |
310 | parent = *p; | |
311 | xcall = rb_entry(parent, struct rxrpc_call, conn_node); | |
312 | ||
313 | if (call_id < xcall->call_id) | |
314 | p = &(*p)->rb_left; | |
315 | else if (call_id > xcall->call_id) | |
316 | p = &(*p)->rb_right; | |
317 | else | |
318 | BUG(); | |
319 | } | |
320 | ||
321 | rb_link_node(&call->conn_node, parent, p); | |
322 | rb_insert_color(&call->conn_node, &conn->calls); | |
323 | ||
324 | write_unlock_bh(&conn->lock); | |
325 | } | |
326 | ||
327 | /* | |
328 | * connect a call on an exclusive connection | |
329 | */ | |
330 | static int rxrpc_connect_exclusive(struct rxrpc_sock *rx, | |
331 | struct rxrpc_transport *trans, | |
332 | __be16 service_id, | |
333 | struct rxrpc_call *call, | |
334 | gfp_t gfp) | |
335 | { | |
336 | struct rxrpc_connection *conn; | |
337 | int chan, ret; | |
338 | ||
339 | _enter(""); | |
340 | ||
341 | conn = rx->conn; | |
342 | if (!conn) { | |
343 | /* not yet present - create a candidate for a new connection | |
344 | * and then redo the check */ | |
345 | conn = rxrpc_alloc_connection(gfp); | |
346 | if (IS_ERR(conn)) { | |
347 | _leave(" = %ld", PTR_ERR(conn)); | |
348 | return PTR_ERR(conn); | |
349 | } | |
350 | ||
351 | conn->trans = trans; | |
352 | conn->bundle = NULL; | |
353 | conn->service_id = service_id; | |
354 | conn->epoch = rxrpc_epoch; | |
355 | conn->in_clientflag = 0; | |
356 | conn->out_clientflag = RXRPC_CLIENT_INITIATED; | |
357 | conn->cid = 0; | |
358 | conn->state = RXRPC_CONN_CLIENT; | |
359 | conn->avail_calls = RXRPC_MAXCALLS; | |
360 | conn->security_level = rx->min_sec_level; | |
361 | conn->key = key_get(rx->key); | |
362 | ||
363 | ret = rxrpc_init_client_conn_security(conn); | |
364 | if (ret < 0) { | |
365 | key_put(conn->key); | |
366 | kfree(conn); | |
367 | _leave(" = %d [key]", ret); | |
368 | return ret; | |
369 | } | |
370 | ||
371 | write_lock_bh(&rxrpc_connection_lock); | |
372 | list_add_tail(&conn->link, &rxrpc_connections); | |
373 | write_unlock_bh(&rxrpc_connection_lock); | |
374 | ||
375 | spin_lock(&trans->client_lock); | |
376 | atomic_inc(&trans->usage); | |
377 | ||
378 | _net("CONNECT EXCL new %d on TRANS %d", | |
379 | conn->debug_id, conn->trans->debug_id); | |
380 | ||
381 | rxrpc_assign_connection_id(conn); | |
382 | rx->conn = conn; | |
383 | } | |
384 | ||
385 | /* we've got a connection with a free channel and we can now attach the | |
386 | * call to it | |
387 | * - we're holding the transport's client lock | |
388 | * - we're holding a reference on the connection | |
389 | */ | |
390 | for (chan = 0; chan < RXRPC_MAXCALLS; chan++) | |
391 | if (!conn->channels[chan]) | |
392 | goto found_channel; | |
393 | goto no_free_channels; | |
394 | ||
395 | found_channel: | |
396 | atomic_inc(&conn->usage); | |
397 | conn->channels[chan] = call; | |
398 | call->conn = conn; | |
399 | call->channel = chan; | |
400 | call->cid = conn->cid | htonl(chan); | |
401 | call->call_id = htonl(++conn->call_counter); | |
402 | ||
403 | _net("CONNECT client on conn %d chan %d as call %x", | |
404 | conn->debug_id, chan, ntohl(call->call_id)); | |
405 | ||
406 | spin_unlock(&trans->client_lock); | |
407 | ||
408 | rxrpc_add_call_ID_to_conn(conn, call); | |
409 | _leave(" = 0"); | |
410 | return 0; | |
411 | ||
412 | no_free_channels: | |
413 | spin_unlock(&trans->client_lock); | |
414 | _leave(" = -ENOSR"); | |
415 | return -ENOSR; | |
416 | } | |
417 | ||
418 | /* | |
419 | * find a connection for a call | |
420 | * - called in process context with IRQs enabled | |
421 | */ | |
422 | int rxrpc_connect_call(struct rxrpc_sock *rx, | |
423 | struct rxrpc_transport *trans, | |
424 | struct rxrpc_conn_bundle *bundle, | |
425 | struct rxrpc_call *call, | |
426 | gfp_t gfp) | |
427 | { | |
428 | struct rxrpc_connection *conn, *candidate; | |
429 | int chan, ret; | |
430 | ||
431 | DECLARE_WAITQUEUE(myself, current); | |
432 | ||
433 | _enter("%p,%lx,", rx, call->user_call_ID); | |
434 | ||
435 | if (test_bit(RXRPC_SOCK_EXCLUSIVE_CONN, &rx->flags)) | |
436 | return rxrpc_connect_exclusive(rx, trans, bundle->service_id, | |
437 | call, gfp); | |
438 | ||
439 | spin_lock(&trans->client_lock); | |
440 | for (;;) { | |
441 | /* see if the bundle has a call slot available */ | |
442 | if (!list_empty(&bundle->avail_conns)) { | |
443 | _debug("avail"); | |
444 | conn = list_entry(bundle->avail_conns.next, | |
445 | struct rxrpc_connection, | |
446 | bundle_link); | |
447 | if (--conn->avail_calls == 0) | |
448 | list_move(&conn->bundle_link, | |
449 | &bundle->busy_conns); | |
450 | atomic_inc(&conn->usage); | |
451 | break; | |
452 | } | |
453 | ||
454 | if (!list_empty(&bundle->unused_conns)) { | |
455 | _debug("unused"); | |
456 | conn = list_entry(bundle->unused_conns.next, | |
457 | struct rxrpc_connection, | |
458 | bundle_link); | |
459 | atomic_inc(&conn->usage); | |
460 | list_move(&conn->bundle_link, &bundle->avail_conns); | |
461 | break; | |
462 | } | |
463 | ||
464 | /* need to allocate a new connection */ | |
465 | _debug("get new conn [%d]", bundle->num_conns); | |
466 | ||
467 | spin_unlock(&trans->client_lock); | |
468 | ||
469 | if (signal_pending(current)) | |
470 | goto interrupted; | |
471 | ||
472 | if (bundle->num_conns >= 20) { | |
473 | _debug("too many conns"); | |
474 | ||
475 | if (!(gfp & __GFP_WAIT)) { | |
476 | _leave(" = -EAGAIN"); | |
477 | return -EAGAIN; | |
478 | } | |
479 | ||
480 | add_wait_queue(&bundle->chanwait, &myself); | |
481 | for (;;) { | |
482 | set_current_state(TASK_INTERRUPTIBLE); | |
483 | if (bundle->num_conns < 20 || | |
484 | !list_empty(&bundle->unused_conns) || | |
485 | !list_empty(&bundle->avail_conns)) | |
486 | break; | |
487 | if (signal_pending(current)) | |
488 | goto interrupted_dequeue; | |
489 | schedule(); | |
490 | } | |
491 | remove_wait_queue(&bundle->chanwait, &myself); | |
492 | __set_current_state(TASK_RUNNING); | |
493 | spin_lock(&trans->client_lock); | |
494 | continue; | |
495 | } | |
496 | ||
497 | /* not yet present - create a candidate for a new connection and then | |
498 | * redo the check */ | |
499 | candidate = rxrpc_alloc_connection(gfp); | |
500 | if (IS_ERR(candidate)) { | |
501 | _leave(" = %ld", PTR_ERR(candidate)); | |
502 | return PTR_ERR(candidate); | |
503 | } | |
504 | ||
505 | candidate->trans = trans; | |
506 | candidate->bundle = bundle; | |
507 | candidate->service_id = bundle->service_id; | |
508 | candidate->epoch = rxrpc_epoch; | |
509 | candidate->in_clientflag = 0; | |
510 | candidate->out_clientflag = RXRPC_CLIENT_INITIATED; | |
511 | candidate->cid = 0; | |
512 | candidate->state = RXRPC_CONN_CLIENT; | |
513 | candidate->avail_calls = RXRPC_MAXCALLS; | |
514 | candidate->security_level = rx->min_sec_level; | |
515 | candidate->key = key_get(rx->key); | |
516 | ||
517 | ret = rxrpc_init_client_conn_security(candidate); | |
518 | if (ret < 0) { | |
519 | key_put(candidate->key); | |
520 | kfree(candidate); | |
521 | _leave(" = %d [key]", ret); | |
522 | return ret; | |
523 | } | |
524 | ||
525 | write_lock_bh(&rxrpc_connection_lock); | |
526 | list_add_tail(&candidate->link, &rxrpc_connections); | |
527 | write_unlock_bh(&rxrpc_connection_lock); | |
528 | ||
529 | spin_lock(&trans->client_lock); | |
530 | ||
531 | list_add(&candidate->bundle_link, &bundle->unused_conns); | |
532 | bundle->num_conns++; | |
533 | atomic_inc(&bundle->usage); | |
534 | atomic_inc(&trans->usage); | |
535 | ||
536 | _net("CONNECT new %d on TRANS %d", | |
537 | candidate->debug_id, candidate->trans->debug_id); | |
538 | ||
539 | rxrpc_assign_connection_id(candidate); | |
540 | if (candidate->security) | |
541 | candidate->security->prime_packet_security(candidate); | |
542 | ||
543 | /* leave the candidate lurking in zombie mode attached to the | |
544 | * bundle until we're ready for it */ | |
545 | rxrpc_put_connection(candidate); | |
546 | candidate = NULL; | |
547 | } | |
548 | ||
549 | /* we've got a connection with a free channel and we can now attach the | |
550 | * call to it | |
551 | * - we're holding the transport's client lock | |
552 | * - we're holding a reference on the connection | |
553 | * - we're holding a reference on the bundle | |
554 | */ | |
555 | for (chan = 0; chan < RXRPC_MAXCALLS; chan++) | |
556 | if (!conn->channels[chan]) | |
557 | goto found_channel; | |
558 | BUG(); | |
559 | ||
560 | found_channel: | |
561 | conn->channels[chan] = call; | |
562 | call->conn = conn; | |
563 | call->channel = chan; | |
564 | call->cid = conn->cid | htonl(chan); | |
565 | call->call_id = htonl(++conn->call_counter); | |
566 | ||
567 | _net("CONNECT client on conn %d chan %d as call %x", | |
568 | conn->debug_id, chan, ntohl(call->call_id)); | |
569 | ||
570 | spin_unlock(&trans->client_lock); | |
571 | ||
572 | rxrpc_add_call_ID_to_conn(conn, call); | |
573 | ||
574 | _leave(" = 0"); | |
575 | return 0; | |
576 | ||
577 | interrupted_dequeue: | |
578 | remove_wait_queue(&bundle->chanwait, &myself); | |
579 | __set_current_state(TASK_RUNNING); | |
580 | interrupted: | |
581 | _leave(" = -ERESTARTSYS"); | |
582 | return -ERESTARTSYS; | |
583 | } | |
584 | ||
585 | /* | |
586 | * get a record of an incoming connection | |
587 | */ | |
588 | struct rxrpc_connection * | |
589 | rxrpc_incoming_connection(struct rxrpc_transport *trans, | |
590 | struct rxrpc_header *hdr, | |
591 | gfp_t gfp) | |
592 | { | |
593 | struct rxrpc_connection *conn, *candidate = NULL; | |
594 | struct rb_node *p, **pp; | |
595 | const char *new = "old"; | |
596 | __be32 epoch; | |
597 | u32 conn_id; | |
598 | ||
599 | _enter(""); | |
600 | ||
601 | ASSERT(hdr->flags & RXRPC_CLIENT_INITIATED); | |
602 | ||
603 | epoch = hdr->epoch; | |
604 | conn_id = ntohl(hdr->cid) & RXRPC_CIDMASK; | |
605 | ||
606 | /* search the connection list first */ | |
607 | read_lock_bh(&trans->conn_lock); | |
608 | ||
609 | p = trans->server_conns.rb_node; | |
610 | while (p) { | |
611 | conn = rb_entry(p, struct rxrpc_connection, node); | |
612 | ||
613 | _debug("maybe %x", conn->real_conn_id); | |
614 | ||
615 | if (epoch < conn->epoch) | |
616 | p = p->rb_left; | |
617 | else if (epoch > conn->epoch) | |
618 | p = p->rb_right; | |
619 | else if (conn_id < conn->real_conn_id) | |
620 | p = p->rb_left; | |
621 | else if (conn_id > conn->real_conn_id) | |
622 | p = p->rb_right; | |
623 | else | |
624 | goto found_extant_connection; | |
625 | } | |
626 | read_unlock_bh(&trans->conn_lock); | |
627 | ||
628 | /* not yet present - create a candidate for a new record and then | |
629 | * redo the search */ | |
630 | candidate = rxrpc_alloc_connection(gfp); | |
631 | if (!candidate) { | |
632 | _leave(" = -ENOMEM"); | |
633 | return ERR_PTR(-ENOMEM); | |
634 | } | |
635 | ||
636 | candidate->trans = trans; | |
637 | candidate->epoch = hdr->epoch; | |
638 | candidate->cid = hdr->cid & __constant_cpu_to_be32(RXRPC_CIDMASK); | |
639 | candidate->service_id = hdr->serviceId; | |
640 | candidate->security_ix = hdr->securityIndex; | |
641 | candidate->in_clientflag = RXRPC_CLIENT_INITIATED; | |
642 | candidate->out_clientflag = 0; | |
643 | candidate->real_conn_id = conn_id; | |
644 | candidate->state = RXRPC_CONN_SERVER; | |
645 | if (candidate->service_id) | |
646 | candidate->state = RXRPC_CONN_SERVER_UNSECURED; | |
647 | ||
648 | write_lock_bh(&trans->conn_lock); | |
649 | ||
650 | pp = &trans->server_conns.rb_node; | |
651 | p = NULL; | |
652 | while (*pp) { | |
653 | p = *pp; | |
654 | conn = rb_entry(p, struct rxrpc_connection, node); | |
655 | ||
656 | if (epoch < conn->epoch) | |
657 | pp = &(*pp)->rb_left; | |
658 | else if (epoch > conn->epoch) | |
659 | pp = &(*pp)->rb_right; | |
660 | else if (conn_id < conn->real_conn_id) | |
661 | pp = &(*pp)->rb_left; | |
662 | else if (conn_id > conn->real_conn_id) | |
663 | pp = &(*pp)->rb_right; | |
664 | else | |
665 | goto found_extant_second; | |
666 | } | |
667 | ||
668 | /* we can now add the new candidate to the list */ | |
669 | conn = candidate; | |
670 | candidate = NULL; | |
671 | rb_link_node(&conn->node, p, pp); | |
672 | rb_insert_color(&conn->node, &trans->server_conns); | |
673 | atomic_inc(&conn->trans->usage); | |
674 | ||
675 | write_unlock_bh(&trans->conn_lock); | |
676 | ||
677 | write_lock_bh(&rxrpc_connection_lock); | |
678 | list_add_tail(&conn->link, &rxrpc_connections); | |
679 | write_unlock_bh(&rxrpc_connection_lock); | |
680 | ||
681 | new = "new"; | |
682 | ||
683 | success: | |
684 | _net("CONNECTION %s %d {%x}", new, conn->debug_id, conn->real_conn_id); | |
685 | ||
686 | _leave(" = %p {u=%d}", conn, atomic_read(&conn->usage)); | |
687 | return conn; | |
688 | ||
689 | /* we found the connection in the list immediately */ | |
690 | found_extant_connection: | |
691 | if (hdr->securityIndex != conn->security_ix) { | |
692 | read_unlock_bh(&trans->conn_lock); | |
693 | goto security_mismatch; | |
694 | } | |
695 | atomic_inc(&conn->usage); | |
696 | read_unlock_bh(&trans->conn_lock); | |
697 | goto success; | |
698 | ||
699 | /* we found the connection on the second time through the list */ | |
700 | found_extant_second: | |
701 | if (hdr->securityIndex != conn->security_ix) { | |
702 | write_unlock_bh(&trans->conn_lock); | |
703 | goto security_mismatch; | |
704 | } | |
705 | atomic_inc(&conn->usage); | |
706 | write_unlock_bh(&trans->conn_lock); | |
707 | kfree(candidate); | |
708 | goto success; | |
709 | ||
710 | security_mismatch: | |
711 | kfree(candidate); | |
712 | _leave(" = -EKEYREJECTED"); | |
713 | return ERR_PTR(-EKEYREJECTED); | |
714 | } | |
715 | ||
716 | /* | |
717 | * find a connection based on transport and RxRPC connection ID for an incoming | |
718 | * packet | |
719 | */ | |
720 | struct rxrpc_connection *rxrpc_find_connection(struct rxrpc_transport *trans, | |
721 | struct rxrpc_header *hdr) | |
722 | { | |
723 | struct rxrpc_connection *conn; | |
724 | struct rb_node *p; | |
725 | __be32 epoch; | |
726 | u32 conn_id; | |
727 | ||
728 | _enter(",{%x,%x}", ntohl(hdr->cid), hdr->flags); | |
729 | ||
730 | read_lock_bh(&trans->conn_lock); | |
731 | ||
732 | conn_id = ntohl(hdr->cid) & RXRPC_CIDMASK; | |
733 | epoch = hdr->epoch; | |
734 | ||
735 | if (hdr->flags & RXRPC_CLIENT_INITIATED) | |
736 | p = trans->server_conns.rb_node; | |
737 | else | |
738 | p = trans->client_conns.rb_node; | |
739 | ||
740 | while (p) { | |
741 | conn = rb_entry(p, struct rxrpc_connection, node); | |
742 | ||
743 | _debug("maybe %x", conn->real_conn_id); | |
744 | ||
745 | if (epoch < conn->epoch) | |
746 | p = p->rb_left; | |
747 | else if (epoch > conn->epoch) | |
748 | p = p->rb_right; | |
749 | else if (conn_id < conn->real_conn_id) | |
750 | p = p->rb_left; | |
751 | else if (conn_id > conn->real_conn_id) | |
752 | p = p->rb_right; | |
753 | else | |
754 | goto found; | |
755 | } | |
756 | ||
757 | read_unlock_bh(&trans->conn_lock); | |
758 | _leave(" = NULL"); | |
759 | return NULL; | |
760 | ||
761 | found: | |
762 | atomic_inc(&conn->usage); | |
763 | read_unlock_bh(&trans->conn_lock); | |
764 | _leave(" = %p", conn); | |
765 | return conn; | |
766 | } | |
767 | ||
768 | /* | |
769 | * release a virtual connection | |
770 | */ | |
771 | void rxrpc_put_connection(struct rxrpc_connection *conn) | |
772 | { | |
773 | _enter("%p{u=%d,d=%d}", | |
774 | conn, atomic_read(&conn->usage), conn->debug_id); | |
775 | ||
776 | ASSERTCMP(atomic_read(&conn->usage), >, 0); | |
777 | ||
778 | conn->put_time = xtime.tv_sec; | |
779 | if (atomic_dec_and_test(&conn->usage)) { | |
780 | _debug("zombie"); | |
781 | schedule_delayed_work(&rxrpc_connection_reap, 0); | |
782 | } | |
783 | ||
784 | _leave(""); | |
785 | } | |
786 | ||
787 | /* | |
788 | * destroy a virtual connection | |
789 | */ | |
790 | static void rxrpc_destroy_connection(struct rxrpc_connection *conn) | |
791 | { | |
792 | _enter("%p{%d}", conn, atomic_read(&conn->usage)); | |
793 | ||
794 | ASSERTCMP(atomic_read(&conn->usage), ==, 0); | |
795 | ||
796 | _net("DESTROY CONN %d", conn->debug_id); | |
797 | ||
798 | if (conn->bundle) | |
799 | rxrpc_put_bundle(conn->trans, conn->bundle); | |
800 | ||
801 | ASSERT(RB_EMPTY_ROOT(&conn->calls)); | |
802 | rxrpc_purge_queue(&conn->rx_queue); | |
803 | ||
804 | rxrpc_clear_conn_security(conn); | |
805 | rxrpc_put_transport(conn->trans); | |
806 | kfree(conn); | |
807 | _leave(""); | |
808 | } | |
809 | ||
810 | /* | |
811 | * reap dead connections | |
812 | */ | |
813 | void rxrpc_connection_reaper(struct work_struct *work) | |
814 | { | |
815 | struct rxrpc_connection *conn, *_p; | |
816 | unsigned long now, earliest, reap_time; | |
817 | ||
818 | LIST_HEAD(graveyard); | |
819 | ||
820 | _enter(""); | |
821 | ||
822 | now = xtime.tv_sec; | |
823 | earliest = ULONG_MAX; | |
824 | ||
825 | write_lock_bh(&rxrpc_connection_lock); | |
826 | list_for_each_entry_safe(conn, _p, &rxrpc_connections, link) { | |
827 | _debug("reap CONN %d { u=%d,t=%ld }", | |
828 | conn->debug_id, atomic_read(&conn->usage), | |
829 | (long) now - (long) conn->put_time); | |
830 | ||
831 | if (likely(atomic_read(&conn->usage) > 0)) | |
832 | continue; | |
833 | ||
834 | spin_lock(&conn->trans->client_lock); | |
835 | write_lock(&conn->trans->conn_lock); | |
836 | reap_time = conn->put_time + rxrpc_connection_timeout; | |
837 | ||
838 | if (atomic_read(&conn->usage) > 0) { | |
839 | ; | |
840 | } else if (reap_time <= now) { | |
841 | list_move_tail(&conn->link, &graveyard); | |
842 | if (conn->out_clientflag) | |
843 | rb_erase(&conn->node, | |
844 | &conn->trans->client_conns); | |
845 | else | |
846 | rb_erase(&conn->node, | |
847 | &conn->trans->server_conns); | |
848 | if (conn->bundle) { | |
849 | list_del_init(&conn->bundle_link); | |
850 | conn->bundle->num_conns--; | |
851 | } | |
852 | ||
853 | } else if (reap_time < earliest) { | |
854 | earliest = reap_time; | |
855 | } | |
856 | ||
857 | write_unlock(&conn->trans->conn_lock); | |
858 | spin_unlock(&conn->trans->client_lock); | |
859 | } | |
860 | write_unlock_bh(&rxrpc_connection_lock); | |
861 | ||
862 | if (earliest != ULONG_MAX) { | |
863 | _debug("reschedule reaper %ld", (long) earliest - now); | |
864 | ASSERTCMP(earliest, >, now); | |
865 | schedule_delayed_work(&rxrpc_connection_reap, | |
866 | (earliest - now) * HZ); | |
867 | } | |
868 | ||
869 | /* then destroy all those pulled out */ | |
870 | while (!list_empty(&graveyard)) { | |
871 | conn = list_entry(graveyard.next, struct rxrpc_connection, | |
872 | link); | |
873 | list_del_init(&conn->link); | |
874 | ||
875 | ASSERTCMP(atomic_read(&conn->usage), ==, 0); | |
876 | rxrpc_destroy_connection(conn); | |
877 | } | |
878 | ||
879 | _leave(""); | |
880 | } | |
881 | ||
882 | /* | |
883 | * preemptively destroy all the connection records rather than waiting for them | |
884 | * to time out | |
885 | */ | |
886 | void __exit rxrpc_destroy_all_connections(void) | |
887 | { | |
888 | _enter(""); | |
889 | ||
890 | rxrpc_connection_timeout = 0; | |
891 | cancel_delayed_work(&rxrpc_connection_reap); | |
892 | schedule_delayed_work(&rxrpc_connection_reap, 0); | |
893 | ||
894 | _leave(""); | |
895 | } |