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1/*
2 * Copyright (c) 2006, 2018 Oracle and/or its affiliates. All rights reserved.
3 *
4 * This software is available to you under a choice of one of two
5 * licenses. You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the
8 * OpenIB.org BSD license below:
9 *
10 * Redistribution and use in source and binary forms, with or
11 * without modification, are permitted provided that the following
12 * conditions are met:
13 *
14 * - Redistributions of source code must retain the above
15 * copyright notice, this list of conditions and the following
16 * disclaimer.
17 *
18 * - Redistributions in binary form must reproduce the above
19 * copyright notice, this list of conditions and the following
20 * disclaimer in the documentation and/or other materials
21 * provided with the distribution.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30 * SOFTWARE.
31 *
32 */
33#include <linux/kernel.h>
34#include <linux/list.h>
35#include <linux/slab.h>
36#include <linux/export.h>
37#include <net/ipv6.h>
38#include <net/inet6_hashtables.h>
39#include <net/addrconf.h>
40
41#include "rds.h"
42#include "loop.h"
43
44#define RDS_CONNECTION_HASH_BITS 12
45#define RDS_CONNECTION_HASH_ENTRIES (1 << RDS_CONNECTION_HASH_BITS)
46#define RDS_CONNECTION_HASH_MASK (RDS_CONNECTION_HASH_ENTRIES - 1)
47
48/* converting this to RCU is a chore for another day.. */
49static DEFINE_SPINLOCK(rds_conn_lock);
50static unsigned long rds_conn_count;
51static struct hlist_head rds_conn_hash[RDS_CONNECTION_HASH_ENTRIES];
52static struct kmem_cache *rds_conn_slab;
53
54static struct hlist_head *rds_conn_bucket(const struct in6_addr *laddr,
55 const struct in6_addr *faddr)
56{
57 static u32 rds6_hash_secret __read_mostly;
58 static u32 rds_hash_secret __read_mostly;
59
60 u32 lhash, fhash, hash;
61
62 net_get_random_once(&rds_hash_secret, sizeof(rds_hash_secret));
63 net_get_random_once(&rds6_hash_secret, sizeof(rds6_hash_secret));
64
65 lhash = (__force u32)laddr->s6_addr32[3];
66#if IS_ENABLED(CONFIG_IPV6)
67 fhash = __ipv6_addr_jhash(faddr, rds6_hash_secret);
68#else
69 fhash = (__force u32)faddr->s6_addr32[3];
70#endif
71 hash = __inet_ehashfn(lhash, 0, fhash, 0, rds_hash_secret);
72
73 return &rds_conn_hash[hash & RDS_CONNECTION_HASH_MASK];
74}
75
76#define rds_conn_info_set(var, test, suffix) do { \
77 if (test) \
78 var |= RDS_INFO_CONNECTION_FLAG_##suffix; \
79} while (0)
80
81/* rcu read lock must be held or the connection spinlock */
82static struct rds_connection *rds_conn_lookup(struct net *net,
83 struct hlist_head *head,
84 const struct in6_addr *laddr,
85 const struct in6_addr *faddr,
86 struct rds_transport *trans,
87 u8 tos, int dev_if)
88{
89 struct rds_connection *conn, *ret = NULL;
90
91 hlist_for_each_entry_rcu(conn, head, c_hash_node) {
92 if (ipv6_addr_equal(&conn->c_faddr, faddr) &&
93 ipv6_addr_equal(&conn->c_laddr, laddr) &&
94 conn->c_trans == trans &&
95 conn->c_tos == tos &&
96 net == rds_conn_net(conn) &&
97 conn->c_dev_if == dev_if) {
98 ret = conn;
99 break;
100 }
101 }
102 rdsdebug("returning conn %p for %pI6c -> %pI6c\n", ret,
103 laddr, faddr);
104 return ret;
105}
106
107/*
108 * This is called by transports as they're bringing down a connection.
109 * It clears partial message state so that the transport can start sending
110 * and receiving over this connection again in the future. It is up to
111 * the transport to have serialized this call with its send and recv.
112 */
113static void rds_conn_path_reset(struct rds_conn_path *cp)
114{
115 struct rds_connection *conn = cp->cp_conn;
116
117 rdsdebug("connection %pI6c to %pI6c reset\n",
118 &conn->c_laddr, &conn->c_faddr);
119
120 rds_stats_inc(s_conn_reset);
121 rds_send_path_reset(cp);
122 cp->cp_flags = 0;
123
124 /* Do not clear next_rx_seq here, else we cannot distinguish
125 * retransmitted packets from new packets, and will hand all
126 * of them to the application. That is not consistent with the
127 * reliability guarantees of RDS. */
128}
129
130static void __rds_conn_path_init(struct rds_connection *conn,
131 struct rds_conn_path *cp, bool is_outgoing)
132{
133 spin_lock_init(&cp->cp_lock);
134 cp->cp_next_tx_seq = 1;
135 init_waitqueue_head(&cp->cp_waitq);
136 INIT_LIST_HEAD(&cp->cp_send_queue);
137 INIT_LIST_HEAD(&cp->cp_retrans);
138
139 cp->cp_conn = conn;
140 atomic_set(&cp->cp_state, RDS_CONN_DOWN);
141 cp->cp_send_gen = 0;
142 cp->cp_reconnect_jiffies = 0;
143 cp->cp_conn->c_proposed_version = RDS_PROTOCOL_VERSION;
144 INIT_DELAYED_WORK(&cp->cp_send_w, rds_send_worker);
145 INIT_DELAYED_WORK(&cp->cp_recv_w, rds_recv_worker);
146 INIT_DELAYED_WORK(&cp->cp_conn_w, rds_connect_worker);
147 INIT_WORK(&cp->cp_down_w, rds_shutdown_worker);
148 mutex_init(&cp->cp_cm_lock);
149 cp->cp_flags = 0;
150}
151
152/*
153 * There is only every one 'conn' for a given pair of addresses in the
154 * system at a time. They contain messages to be retransmitted and so
155 * span the lifetime of the actual underlying transport connections.
156 *
157 * For now they are not garbage collected once they're created. They
158 * are torn down as the module is removed, if ever.
159 */
160static struct rds_connection *__rds_conn_create(struct net *net,
161 const struct in6_addr *laddr,
162 const struct in6_addr *faddr,
163 struct rds_transport *trans,
164 gfp_t gfp, u8 tos,
165 int is_outgoing,
166 int dev_if)
167{
168 struct rds_connection *conn, *parent = NULL;
169 struct hlist_head *head = rds_conn_bucket(laddr, faddr);
170 struct rds_transport *loop_trans;
171 unsigned long flags;
172 int ret, i;
173 int npaths = (trans->t_mp_capable ? RDS_MPATH_WORKERS : 1);
174
175 rcu_read_lock();
176 conn = rds_conn_lookup(net, head, laddr, faddr, trans, tos, dev_if);
177 if (conn &&
178 conn->c_loopback &&
179 conn->c_trans != &rds_loop_transport &&
180 ipv6_addr_equal(laddr, faddr) &&
181 !is_outgoing) {
182 /* This is a looped back IB connection, and we're
183 * called by the code handling the incoming connect.
184 * We need a second connection object into which we
185 * can stick the other QP. */
186 parent = conn;
187 conn = parent->c_passive;
188 }
189 rcu_read_unlock();
190 if (conn)
191 goto out;
192
193 conn = kmem_cache_zalloc(rds_conn_slab, gfp);
194 if (!conn) {
195 conn = ERR_PTR(-ENOMEM);
196 goto out;
197 }
198 conn->c_path = kcalloc(npaths, sizeof(struct rds_conn_path), gfp);
199 if (!conn->c_path) {
200 kmem_cache_free(rds_conn_slab, conn);
201 conn = ERR_PTR(-ENOMEM);
202 goto out;
203 }
204
205 INIT_HLIST_NODE(&conn->c_hash_node);
206 conn->c_laddr = *laddr;
207 conn->c_isv6 = !ipv6_addr_v4mapped(laddr);
208 conn->c_faddr = *faddr;
209 conn->c_dev_if = dev_if;
210 conn->c_tos = tos;
211
212#if IS_ENABLED(CONFIG_IPV6)
213 /* If the local address is link local, set c_bound_if to be the
214 * index used for this connection. Otherwise, set it to 0 as
215 * the socket is not bound to an interface. c_bound_if is used
216 * to look up a socket when a packet is received
217 */
218 if (ipv6_addr_type(laddr) & IPV6_ADDR_LINKLOCAL)
219 conn->c_bound_if = dev_if;
220 else
221#endif
222 conn->c_bound_if = 0;
223
224 rds_conn_net_set(conn, net);
225
226 ret = rds_cong_get_maps(conn);
227 if (ret) {
228 kfree(conn->c_path);
229 kmem_cache_free(rds_conn_slab, conn);
230 conn = ERR_PTR(ret);
231 goto out;
232 }
233
234 /*
235 * This is where a connection becomes loopback. If *any* RDS sockets
236 * can bind to the destination address then we'd rather the messages
237 * flow through loopback rather than either transport.
238 */
239 loop_trans = rds_trans_get_preferred(net, faddr, conn->c_dev_if);
240 if (loop_trans) {
241 rds_trans_put(loop_trans);
242 conn->c_loopback = 1;
243 if (is_outgoing && trans->t_prefer_loopback) {
244 /* "outgoing" connection - and the transport
245 * says it wants the connection handled by the
246 * loopback transport. This is what TCP does.
247 */
248 trans = &rds_loop_transport;
249 }
250 }
251
252 conn->c_trans = trans;
253
254 init_waitqueue_head(&conn->c_hs_waitq);
255 for (i = 0; i < npaths; i++) {
256 __rds_conn_path_init(conn, &conn->c_path[i],
257 is_outgoing);
258 conn->c_path[i].cp_index = i;
259 }
260 rcu_read_lock();
261 if (rds_destroy_pending(conn))
262 ret = -ENETDOWN;
263 else
264 ret = trans->conn_alloc(conn, GFP_ATOMIC);
265 if (ret) {
266 rcu_read_unlock();
267 kfree(conn->c_path);
268 kmem_cache_free(rds_conn_slab, conn);
269 conn = ERR_PTR(ret);
270 goto out;
271 }
272
273 rdsdebug("allocated conn %p for %pI6c -> %pI6c over %s %s\n",
274 conn, laddr, faddr,
275 strnlen(trans->t_name, sizeof(trans->t_name)) ?
276 trans->t_name : "[unknown]", is_outgoing ? "(outgoing)" : "");
277
278 /*
279 * Since we ran without holding the conn lock, someone could
280 * have created the same conn (either normal or passive) in the
281 * interim. We check while holding the lock. If we won, we complete
282 * init and return our conn. If we lost, we rollback and return the
283 * other one.
284 */
285 spin_lock_irqsave(&rds_conn_lock, flags);
286 if (parent) {
287 /* Creating passive conn */
288 if (parent->c_passive) {
289 trans->conn_free(conn->c_path[0].cp_transport_data);
290 kfree(conn->c_path);
291 kmem_cache_free(rds_conn_slab, conn);
292 conn = parent->c_passive;
293 } else {
294 parent->c_passive = conn;
295 rds_cong_add_conn(conn);
296 rds_conn_count++;
297 }
298 } else {
299 /* Creating normal conn */
300 struct rds_connection *found;
301
302 found = rds_conn_lookup(net, head, laddr, faddr, trans,
303 tos, dev_if);
304 if (found) {
305 struct rds_conn_path *cp;
306 int i;
307
308 for (i = 0; i < npaths; i++) {
309 cp = &conn->c_path[i];
310 /* The ->conn_alloc invocation may have
311 * allocated resource for all paths, so all
312 * of them may have to be freed here.
313 */
314 if (cp->cp_transport_data)
315 trans->conn_free(cp->cp_transport_data);
316 }
317 kfree(conn->c_path);
318 kmem_cache_free(rds_conn_slab, conn);
319 conn = found;
320 } else {
321 conn->c_my_gen_num = rds_gen_num;
322 conn->c_peer_gen_num = 0;
323 hlist_add_head_rcu(&conn->c_hash_node, head);
324 rds_cong_add_conn(conn);
325 rds_conn_count++;
326 }
327 }
328 spin_unlock_irqrestore(&rds_conn_lock, flags);
329 rcu_read_unlock();
330
331out:
332 return conn;
333}
334
335struct rds_connection *rds_conn_create(struct net *net,
336 const struct in6_addr *laddr,
337 const struct in6_addr *faddr,
338 struct rds_transport *trans, u8 tos,
339 gfp_t gfp, int dev_if)
340{
341 return __rds_conn_create(net, laddr, faddr, trans, gfp, tos, 0, dev_if);
342}
343EXPORT_SYMBOL_GPL(rds_conn_create);
344
345struct rds_connection *rds_conn_create_outgoing(struct net *net,
346 const struct in6_addr *laddr,
347 const struct in6_addr *faddr,
348 struct rds_transport *trans,
349 u8 tos, gfp_t gfp, int dev_if)
350{
351 return __rds_conn_create(net, laddr, faddr, trans, gfp, tos, 1, dev_if);
352}
353EXPORT_SYMBOL_GPL(rds_conn_create_outgoing);
354
355void rds_conn_shutdown(struct rds_conn_path *cp)
356{
357 struct rds_connection *conn = cp->cp_conn;
358
359 /* shut it down unless it's down already */
360 if (!rds_conn_path_transition(cp, RDS_CONN_DOWN, RDS_CONN_DOWN)) {
361 /*
362 * Quiesce the connection mgmt handlers before we start tearing
363 * things down. We don't hold the mutex for the entire
364 * duration of the shutdown operation, else we may be
365 * deadlocking with the CM handler. Instead, the CM event
366 * handler is supposed to check for state DISCONNECTING
367 */
368 mutex_lock(&cp->cp_cm_lock);
369 if (!rds_conn_path_transition(cp, RDS_CONN_UP,
370 RDS_CONN_DISCONNECTING) &&
371 !rds_conn_path_transition(cp, RDS_CONN_ERROR,
372 RDS_CONN_DISCONNECTING)) {
373 rds_conn_path_error(cp,
374 "shutdown called in state %d\n",
375 atomic_read(&cp->cp_state));
376 mutex_unlock(&cp->cp_cm_lock);
377 return;
378 }
379 mutex_unlock(&cp->cp_cm_lock);
380
381 wait_event(cp->cp_waitq,
382 !test_bit(RDS_IN_XMIT, &cp->cp_flags));
383 wait_event(cp->cp_waitq,
384 !test_bit(RDS_RECV_REFILL, &cp->cp_flags));
385
386 conn->c_trans->conn_path_shutdown(cp);
387 rds_conn_path_reset(cp);
388
389 if (!rds_conn_path_transition(cp, RDS_CONN_DISCONNECTING,
390 RDS_CONN_DOWN) &&
391 !rds_conn_path_transition(cp, RDS_CONN_ERROR,
392 RDS_CONN_DOWN)) {
393 /* This can happen - eg when we're in the middle of tearing
394 * down the connection, and someone unloads the rds module.
395 * Quite reproducible with loopback connections.
396 * Mostly harmless.
397 *
398 * Note that this also happens with rds-tcp because
399 * we could have triggered rds_conn_path_drop in irq
400 * mode from rds_tcp_state change on the receipt of
401 * a FIN, thus we need to recheck for RDS_CONN_ERROR
402 * here.
403 */
404 rds_conn_path_error(cp, "%s: failed to transition "
405 "to state DOWN, current state "
406 "is %d\n", __func__,
407 atomic_read(&cp->cp_state));
408 return;
409 }
410 }
411
412 /* Then reconnect if it's still live.
413 * The passive side of an IB loopback connection is never added
414 * to the conn hash, so we never trigger a reconnect on this
415 * conn - the reconnect is always triggered by the active peer. */
416 cancel_delayed_work_sync(&cp->cp_conn_w);
417 rcu_read_lock();
418 if (!hlist_unhashed(&conn->c_hash_node)) {
419 rcu_read_unlock();
420 rds_queue_reconnect(cp);
421 } else {
422 rcu_read_unlock();
423 }
424}
425
426/* destroy a single rds_conn_path. rds_conn_destroy() iterates over
427 * all paths using rds_conn_path_destroy()
428 */
429static void rds_conn_path_destroy(struct rds_conn_path *cp)
430{
431 struct rds_message *rm, *rtmp;
432
433 if (!cp->cp_transport_data)
434 return;
435
436 /* make sure lingering queued work won't try to ref the conn */
437 cancel_delayed_work_sync(&cp->cp_send_w);
438 cancel_delayed_work_sync(&cp->cp_recv_w);
439
440 rds_conn_path_drop(cp, true);
441 flush_work(&cp->cp_down_w);
442
443 /* tear down queued messages */
444 list_for_each_entry_safe(rm, rtmp,
445 &cp->cp_send_queue,
446 m_conn_item) {
447 list_del_init(&rm->m_conn_item);
448 BUG_ON(!list_empty(&rm->m_sock_item));
449 rds_message_put(rm);
450 }
451 if (cp->cp_xmit_rm)
452 rds_message_put(cp->cp_xmit_rm);
453
454 WARN_ON(delayed_work_pending(&cp->cp_send_w));
455 WARN_ON(delayed_work_pending(&cp->cp_recv_w));
456 WARN_ON(delayed_work_pending(&cp->cp_conn_w));
457 WARN_ON(work_pending(&cp->cp_down_w));
458
459 cp->cp_conn->c_trans->conn_free(cp->cp_transport_data);
460}
461
462/*
463 * Stop and free a connection.
464 *
465 * This can only be used in very limited circumstances. It assumes that once
466 * the conn has been shutdown that no one else is referencing the connection.
467 * We can only ensure this in the rmmod path in the current code.
468 */
469void rds_conn_destroy(struct rds_connection *conn)
470{
471 unsigned long flags;
472 int i;
473 struct rds_conn_path *cp;
474 int npaths = (conn->c_trans->t_mp_capable ? RDS_MPATH_WORKERS : 1);
475
476 rdsdebug("freeing conn %p for %pI4 -> "
477 "%pI4\n", conn, &conn->c_laddr,
478 &conn->c_faddr);
479
480 /* Ensure conn will not be scheduled for reconnect */
481 spin_lock_irq(&rds_conn_lock);
482 hlist_del_init_rcu(&conn->c_hash_node);
483 spin_unlock_irq(&rds_conn_lock);
484 synchronize_rcu();
485
486 /* shut the connection down */
487 for (i = 0; i < npaths; i++) {
488 cp = &conn->c_path[i];
489 rds_conn_path_destroy(cp);
490 BUG_ON(!list_empty(&cp->cp_retrans));
491 }
492
493 /*
494 * The congestion maps aren't freed up here. They're
495 * freed by rds_cong_exit() after all the connections
496 * have been freed.
497 */
498 rds_cong_remove_conn(conn);
499
500 kfree(conn->c_path);
501 kmem_cache_free(rds_conn_slab, conn);
502
503 spin_lock_irqsave(&rds_conn_lock, flags);
504 rds_conn_count--;
505 spin_unlock_irqrestore(&rds_conn_lock, flags);
506}
507EXPORT_SYMBOL_GPL(rds_conn_destroy);
508
509static void __rds_inc_msg_cp(struct rds_incoming *inc,
510 struct rds_info_iterator *iter,
511 void *saddr, void *daddr, int flip, bool isv6)
512{
513#if IS_ENABLED(CONFIG_IPV6)
514 if (isv6)
515 rds6_inc_info_copy(inc, iter, saddr, daddr, flip);
516 else
517#endif
518 rds_inc_info_copy(inc, iter, *(__be32 *)saddr,
519 *(__be32 *)daddr, flip);
520}
521
522static void rds_conn_message_info_cmn(struct socket *sock, unsigned int len,
523 struct rds_info_iterator *iter,
524 struct rds_info_lengths *lens,
525 int want_send, bool isv6)
526{
527 struct hlist_head *head;
528 struct list_head *list;
529 struct rds_connection *conn;
530 struct rds_message *rm;
531 unsigned int total = 0;
532 unsigned long flags;
533 size_t i;
534 int j;
535
536 if (isv6)
537 len /= sizeof(struct rds6_info_message);
538 else
539 len /= sizeof(struct rds_info_message);
540
541 rcu_read_lock();
542
543 for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
544 i++, head++) {
545 hlist_for_each_entry_rcu(conn, head, c_hash_node) {
546 struct rds_conn_path *cp;
547 int npaths;
548
549 if (!isv6 && conn->c_isv6)
550 continue;
551
552 npaths = (conn->c_trans->t_mp_capable ?
553 RDS_MPATH_WORKERS : 1);
554
555 for (j = 0; j < npaths; j++) {
556 cp = &conn->c_path[j];
557 if (want_send)
558 list = &cp->cp_send_queue;
559 else
560 list = &cp->cp_retrans;
561
562 spin_lock_irqsave(&cp->cp_lock, flags);
563
564 /* XXX too lazy to maintain counts.. */
565 list_for_each_entry(rm, list, m_conn_item) {
566 total++;
567 if (total <= len)
568 __rds_inc_msg_cp(&rm->m_inc,
569 iter,
570 &conn->c_laddr,
571 &conn->c_faddr,
572 0, isv6);
573 }
574
575 spin_unlock_irqrestore(&cp->cp_lock, flags);
576 }
577 }
578 }
579 rcu_read_unlock();
580
581 lens->nr = total;
582 if (isv6)
583 lens->each = sizeof(struct rds6_info_message);
584 else
585 lens->each = sizeof(struct rds_info_message);
586}
587
588static void rds_conn_message_info(struct socket *sock, unsigned int len,
589 struct rds_info_iterator *iter,
590 struct rds_info_lengths *lens,
591 int want_send)
592{
593 rds_conn_message_info_cmn(sock, len, iter, lens, want_send, false);
594}
595
596#if IS_ENABLED(CONFIG_IPV6)
597static void rds6_conn_message_info(struct socket *sock, unsigned int len,
598 struct rds_info_iterator *iter,
599 struct rds_info_lengths *lens,
600 int want_send)
601{
602 rds_conn_message_info_cmn(sock, len, iter, lens, want_send, true);
603}
604#endif
605
606static void rds_conn_message_info_send(struct socket *sock, unsigned int len,
607 struct rds_info_iterator *iter,
608 struct rds_info_lengths *lens)
609{
610 rds_conn_message_info(sock, len, iter, lens, 1);
611}
612
613#if IS_ENABLED(CONFIG_IPV6)
614static void rds6_conn_message_info_send(struct socket *sock, unsigned int len,
615 struct rds_info_iterator *iter,
616 struct rds_info_lengths *lens)
617{
618 rds6_conn_message_info(sock, len, iter, lens, 1);
619}
620#endif
621
622static void rds_conn_message_info_retrans(struct socket *sock,
623 unsigned int len,
624 struct rds_info_iterator *iter,
625 struct rds_info_lengths *lens)
626{
627 rds_conn_message_info(sock, len, iter, lens, 0);
628}
629
630#if IS_ENABLED(CONFIG_IPV6)
631static void rds6_conn_message_info_retrans(struct socket *sock,
632 unsigned int len,
633 struct rds_info_iterator *iter,
634 struct rds_info_lengths *lens)
635{
636 rds6_conn_message_info(sock, len, iter, lens, 0);
637}
638#endif
639
640void rds_for_each_conn_info(struct socket *sock, unsigned int len,
641 struct rds_info_iterator *iter,
642 struct rds_info_lengths *lens,
643 int (*visitor)(struct rds_connection *, void *),
644 u64 *buffer,
645 size_t item_len)
646{
647 struct hlist_head *head;
648 struct rds_connection *conn;
649 size_t i;
650
651 rcu_read_lock();
652
653 lens->nr = 0;
654 lens->each = item_len;
655
656 for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
657 i++, head++) {
658 hlist_for_each_entry_rcu(conn, head, c_hash_node) {
659
660 /* XXX no c_lock usage.. */
661 if (!visitor(conn, buffer))
662 continue;
663
664 /* We copy as much as we can fit in the buffer,
665 * but we count all items so that the caller
666 * can resize the buffer. */
667 if (len >= item_len) {
668 rds_info_copy(iter, buffer, item_len);
669 len -= item_len;
670 }
671 lens->nr++;
672 }
673 }
674 rcu_read_unlock();
675}
676EXPORT_SYMBOL_GPL(rds_for_each_conn_info);
677
678static void rds_walk_conn_path_info(struct socket *sock, unsigned int len,
679 struct rds_info_iterator *iter,
680 struct rds_info_lengths *lens,
681 int (*visitor)(struct rds_conn_path *, void *),
682 u64 *buffer,
683 size_t item_len)
684{
685 struct hlist_head *head;
686 struct rds_connection *conn;
687 size_t i;
688
689 rcu_read_lock();
690
691 lens->nr = 0;
692 lens->each = item_len;
693
694 for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
695 i++, head++) {
696 hlist_for_each_entry_rcu(conn, head, c_hash_node) {
697 struct rds_conn_path *cp;
698
699 /* XXX We only copy the information from the first
700 * path for now. The problem is that if there are
701 * more than one underlying paths, we cannot report
702 * information of all of them using the existing
703 * API. For example, there is only one next_tx_seq,
704 * which path's next_tx_seq should we report? It is
705 * a bug in the design of MPRDS.
706 */
707 cp = conn->c_path;
708
709 /* XXX no cp_lock usage.. */
710 if (!visitor(cp, buffer))
711 continue;
712
713 /* We copy as much as we can fit in the buffer,
714 * but we count all items so that the caller
715 * can resize the buffer.
716 */
717 if (len >= item_len) {
718 rds_info_copy(iter, buffer, item_len);
719 len -= item_len;
720 }
721 lens->nr++;
722 }
723 }
724 rcu_read_unlock();
725}
726
727static int rds_conn_info_visitor(struct rds_conn_path *cp, void *buffer)
728{
729 struct rds_info_connection *cinfo = buffer;
730 struct rds_connection *conn = cp->cp_conn;
731
732 if (conn->c_isv6)
733 return 0;
734
735 cinfo->next_tx_seq = cp->cp_next_tx_seq;
736 cinfo->next_rx_seq = cp->cp_next_rx_seq;
737 cinfo->laddr = conn->c_laddr.s6_addr32[3];
738 cinfo->faddr = conn->c_faddr.s6_addr32[3];
739 cinfo->tos = conn->c_tos;
740 strncpy(cinfo->transport, conn->c_trans->t_name,
741 sizeof(cinfo->transport));
742 cinfo->flags = 0;
743
744 rds_conn_info_set(cinfo->flags, test_bit(RDS_IN_XMIT, &cp->cp_flags),
745 SENDING);
746 /* XXX Future: return the state rather than these funky bits */
747 rds_conn_info_set(cinfo->flags,
748 atomic_read(&cp->cp_state) == RDS_CONN_CONNECTING,
749 CONNECTING);
750 rds_conn_info_set(cinfo->flags,
751 atomic_read(&cp->cp_state) == RDS_CONN_UP,
752 CONNECTED);
753 return 1;
754}
755
756#if IS_ENABLED(CONFIG_IPV6)
757static int rds6_conn_info_visitor(struct rds_conn_path *cp, void *buffer)
758{
759 struct rds6_info_connection *cinfo6 = buffer;
760 struct rds_connection *conn = cp->cp_conn;
761
762 cinfo6->next_tx_seq = cp->cp_next_tx_seq;
763 cinfo6->next_rx_seq = cp->cp_next_rx_seq;
764 cinfo6->laddr = conn->c_laddr;
765 cinfo6->faddr = conn->c_faddr;
766 strncpy(cinfo6->transport, conn->c_trans->t_name,
767 sizeof(cinfo6->transport));
768 cinfo6->flags = 0;
769
770 rds_conn_info_set(cinfo6->flags, test_bit(RDS_IN_XMIT, &cp->cp_flags),
771 SENDING);
772 /* XXX Future: return the state rather than these funky bits */
773 rds_conn_info_set(cinfo6->flags,
774 atomic_read(&cp->cp_state) == RDS_CONN_CONNECTING,
775 CONNECTING);
776 rds_conn_info_set(cinfo6->flags,
777 atomic_read(&cp->cp_state) == RDS_CONN_UP,
778 CONNECTED);
779 /* Just return 1 as there is no error case. This is a helper function
780 * for rds_walk_conn_path_info() and it wants a return value.
781 */
782 return 1;
783}
784#endif
785
786static void rds_conn_info(struct socket *sock, unsigned int len,
787 struct rds_info_iterator *iter,
788 struct rds_info_lengths *lens)
789{
790 u64 buffer[(sizeof(struct rds_info_connection) + 7) / 8];
791
792 rds_walk_conn_path_info(sock, len, iter, lens,
793 rds_conn_info_visitor,
794 buffer,
795 sizeof(struct rds_info_connection));
796}
797
798#if IS_ENABLED(CONFIG_IPV6)
799static void rds6_conn_info(struct socket *sock, unsigned int len,
800 struct rds_info_iterator *iter,
801 struct rds_info_lengths *lens)
802{
803 u64 buffer[(sizeof(struct rds6_info_connection) + 7) / 8];
804
805 rds_walk_conn_path_info(sock, len, iter, lens,
806 rds6_conn_info_visitor,
807 buffer,
808 sizeof(struct rds6_info_connection));
809}
810#endif
811
812int rds_conn_init(void)
813{
814 int ret;
815
816 ret = rds_loop_net_init(); /* register pernet callback */
817 if (ret)
818 return ret;
819
820 rds_conn_slab = kmem_cache_create("rds_connection",
821 sizeof(struct rds_connection),
822 0, 0, NULL);
823 if (!rds_conn_slab) {
824 rds_loop_net_exit();
825 return -ENOMEM;
826 }
827
828 rds_info_register_func(RDS_INFO_CONNECTIONS, rds_conn_info);
829 rds_info_register_func(RDS_INFO_SEND_MESSAGES,
830 rds_conn_message_info_send);
831 rds_info_register_func(RDS_INFO_RETRANS_MESSAGES,
832 rds_conn_message_info_retrans);
833#if IS_ENABLED(CONFIG_IPV6)
834 rds_info_register_func(RDS6_INFO_CONNECTIONS, rds6_conn_info);
835 rds_info_register_func(RDS6_INFO_SEND_MESSAGES,
836 rds6_conn_message_info_send);
837 rds_info_register_func(RDS6_INFO_RETRANS_MESSAGES,
838 rds6_conn_message_info_retrans);
839#endif
840 return 0;
841}
842
843void rds_conn_exit(void)
844{
845 rds_loop_net_exit(); /* unregister pernet callback */
846 rds_loop_exit();
847
848 WARN_ON(!hlist_empty(rds_conn_hash));
849
850 kmem_cache_destroy(rds_conn_slab);
851
852 rds_info_deregister_func(RDS_INFO_CONNECTIONS, rds_conn_info);
853 rds_info_deregister_func(RDS_INFO_SEND_MESSAGES,
854 rds_conn_message_info_send);
855 rds_info_deregister_func(RDS_INFO_RETRANS_MESSAGES,
856 rds_conn_message_info_retrans);
857#if IS_ENABLED(CONFIG_IPV6)
858 rds_info_deregister_func(RDS6_INFO_CONNECTIONS, rds6_conn_info);
859 rds_info_deregister_func(RDS6_INFO_SEND_MESSAGES,
860 rds6_conn_message_info_send);
861 rds_info_deregister_func(RDS6_INFO_RETRANS_MESSAGES,
862 rds6_conn_message_info_retrans);
863#endif
864}
865
866/*
867 * Force a disconnect
868 */
869void rds_conn_path_drop(struct rds_conn_path *cp, bool destroy)
870{
871 atomic_set(&cp->cp_state, RDS_CONN_ERROR);
872
873 rcu_read_lock();
874 if (!destroy && rds_destroy_pending(cp->cp_conn)) {
875 rcu_read_unlock();
876 return;
877 }
878 queue_work(rds_wq, &cp->cp_down_w);
879 rcu_read_unlock();
880}
881EXPORT_SYMBOL_GPL(rds_conn_path_drop);
882
883void rds_conn_drop(struct rds_connection *conn)
884{
885 WARN_ON(conn->c_trans->t_mp_capable);
886 rds_conn_path_drop(&conn->c_path[0], false);
887}
888EXPORT_SYMBOL_GPL(rds_conn_drop);
889
890/*
891 * If the connection is down, trigger a connect. We may have scheduled a
892 * delayed reconnect however - in this case we should not interfere.
893 */
894void rds_conn_path_connect_if_down(struct rds_conn_path *cp)
895{
896 rcu_read_lock();
897 if (rds_destroy_pending(cp->cp_conn)) {
898 rcu_read_unlock();
899 return;
900 }
901 if (rds_conn_path_state(cp) == RDS_CONN_DOWN &&
902 !test_and_set_bit(RDS_RECONNECT_PENDING, &cp->cp_flags))
903 queue_delayed_work(rds_wq, &cp->cp_conn_w, 0);
904 rcu_read_unlock();
905}
906EXPORT_SYMBOL_GPL(rds_conn_path_connect_if_down);
907
908/* Check connectivity of all paths
909 */
910void rds_check_all_paths(struct rds_connection *conn)
911{
912 int i = 0;
913
914 do {
915 rds_conn_path_connect_if_down(&conn->c_path[i]);
916 } while (++i < conn->c_npaths);
917}
918
919void rds_conn_connect_if_down(struct rds_connection *conn)
920{
921 WARN_ON(conn->c_trans->t_mp_capable);
922 rds_conn_path_connect_if_down(&conn->c_path[0]);
923}
924EXPORT_SYMBOL_GPL(rds_conn_connect_if_down);
925
926void
927__rds_conn_path_error(struct rds_conn_path *cp, const char *fmt, ...)
928{
929 va_list ap;
930
931 va_start(ap, fmt);
932 vprintk(fmt, ap);
933 va_end(ap);
934
935 rds_conn_path_drop(cp, false);
936}
1/*
2 * Copyright (c) 2006 Oracle. All rights reserved.
3 *
4 * This software is available to you under a choice of one of two
5 * licenses. You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the
8 * OpenIB.org BSD license below:
9 *
10 * Redistribution and use in source and binary forms, with or
11 * without modification, are permitted provided that the following
12 * conditions are met:
13 *
14 * - Redistributions of source code must retain the above
15 * copyright notice, this list of conditions and the following
16 * disclaimer.
17 *
18 * - Redistributions in binary form must reproduce the above
19 * copyright notice, this list of conditions and the following
20 * disclaimer in the documentation and/or other materials
21 * provided with the distribution.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30 * SOFTWARE.
31 *
32 */
33#include <linux/kernel.h>
34#include <linux/list.h>
35#include <linux/slab.h>
36#include <linux/export.h>
37#include <net/inet_hashtables.h>
38
39#include "rds.h"
40#include "loop.h"
41
42#define RDS_CONNECTION_HASH_BITS 12
43#define RDS_CONNECTION_HASH_ENTRIES (1 << RDS_CONNECTION_HASH_BITS)
44#define RDS_CONNECTION_HASH_MASK (RDS_CONNECTION_HASH_ENTRIES - 1)
45
46/* converting this to RCU is a chore for another day.. */
47static DEFINE_SPINLOCK(rds_conn_lock);
48static unsigned long rds_conn_count;
49static struct hlist_head rds_conn_hash[RDS_CONNECTION_HASH_ENTRIES];
50static struct kmem_cache *rds_conn_slab;
51
52static struct hlist_head *rds_conn_bucket(__be32 laddr, __be32 faddr)
53{
54 static u32 rds_hash_secret __read_mostly;
55
56 unsigned long hash;
57
58 net_get_random_once(&rds_hash_secret, sizeof(rds_hash_secret));
59
60 /* Pass NULL, don't need struct net for hash */
61 hash = __inet_ehashfn(be32_to_cpu(laddr), 0,
62 be32_to_cpu(faddr), 0,
63 rds_hash_secret);
64 return &rds_conn_hash[hash & RDS_CONNECTION_HASH_MASK];
65}
66
67#define rds_conn_info_set(var, test, suffix) do { \
68 if (test) \
69 var |= RDS_INFO_CONNECTION_FLAG_##suffix; \
70} while (0)
71
72/* rcu read lock must be held or the connection spinlock */
73static struct rds_connection *rds_conn_lookup(struct net *net,
74 struct hlist_head *head,
75 __be32 laddr, __be32 faddr,
76 struct rds_transport *trans)
77{
78 struct rds_connection *conn, *ret = NULL;
79
80 hlist_for_each_entry_rcu(conn, head, c_hash_node) {
81 if (conn->c_faddr == faddr && conn->c_laddr == laddr &&
82 conn->c_trans == trans && net == rds_conn_net(conn)) {
83 ret = conn;
84 break;
85 }
86 }
87 rdsdebug("returning conn %p for %pI4 -> %pI4\n", ret,
88 &laddr, &faddr);
89 return ret;
90}
91
92/*
93 * This is called by transports as they're bringing down a connection.
94 * It clears partial message state so that the transport can start sending
95 * and receiving over this connection again in the future. It is up to
96 * the transport to have serialized this call with its send and recv.
97 */
98static void rds_conn_path_reset(struct rds_conn_path *cp)
99{
100 struct rds_connection *conn = cp->cp_conn;
101
102 rdsdebug("connection %pI4 to %pI4 reset\n",
103 &conn->c_laddr, &conn->c_faddr);
104
105 rds_stats_inc(s_conn_reset);
106 rds_send_path_reset(cp);
107 cp->cp_flags = 0;
108
109 /* Do not clear next_rx_seq here, else we cannot distinguish
110 * retransmitted packets from new packets, and will hand all
111 * of them to the application. That is not consistent with the
112 * reliability guarantees of RDS. */
113}
114
115static void __rds_conn_path_init(struct rds_connection *conn,
116 struct rds_conn_path *cp, bool is_outgoing)
117{
118 spin_lock_init(&cp->cp_lock);
119 cp->cp_next_tx_seq = 1;
120 init_waitqueue_head(&cp->cp_waitq);
121 INIT_LIST_HEAD(&cp->cp_send_queue);
122 INIT_LIST_HEAD(&cp->cp_retrans);
123
124 cp->cp_conn = conn;
125 atomic_set(&cp->cp_state, RDS_CONN_DOWN);
126 cp->cp_send_gen = 0;
127 /* cp_outgoing is per-path. So we can only set it here
128 * for the single-path transports.
129 */
130 if (!conn->c_trans->t_mp_capable)
131 cp->cp_outgoing = (is_outgoing ? 1 : 0);
132 cp->cp_reconnect_jiffies = 0;
133 INIT_DELAYED_WORK(&cp->cp_send_w, rds_send_worker);
134 INIT_DELAYED_WORK(&cp->cp_recv_w, rds_recv_worker);
135 INIT_DELAYED_WORK(&cp->cp_conn_w, rds_connect_worker);
136 INIT_WORK(&cp->cp_down_w, rds_shutdown_worker);
137 mutex_init(&cp->cp_cm_lock);
138 cp->cp_flags = 0;
139}
140
141/*
142 * There is only every one 'conn' for a given pair of addresses in the
143 * system at a time. They contain messages to be retransmitted and so
144 * span the lifetime of the actual underlying transport connections.
145 *
146 * For now they are not garbage collected once they're created. They
147 * are torn down as the module is removed, if ever.
148 */
149static struct rds_connection *__rds_conn_create(struct net *net,
150 __be32 laddr, __be32 faddr,
151 struct rds_transport *trans, gfp_t gfp,
152 int is_outgoing)
153{
154 struct rds_connection *conn, *parent = NULL;
155 struct hlist_head *head = rds_conn_bucket(laddr, faddr);
156 struct rds_transport *loop_trans;
157 unsigned long flags;
158 int ret, i;
159
160 rcu_read_lock();
161 conn = rds_conn_lookup(net, head, laddr, faddr, trans);
162 if (conn && conn->c_loopback && conn->c_trans != &rds_loop_transport &&
163 laddr == faddr && !is_outgoing) {
164 /* This is a looped back IB connection, and we're
165 * called by the code handling the incoming connect.
166 * We need a second connection object into which we
167 * can stick the other QP. */
168 parent = conn;
169 conn = parent->c_passive;
170 }
171 rcu_read_unlock();
172 if (conn)
173 goto out;
174
175 conn = kmem_cache_zalloc(rds_conn_slab, gfp);
176 if (!conn) {
177 conn = ERR_PTR(-ENOMEM);
178 goto out;
179 }
180
181 INIT_HLIST_NODE(&conn->c_hash_node);
182 conn->c_laddr = laddr;
183 conn->c_faddr = faddr;
184
185 rds_conn_net_set(conn, net);
186
187 ret = rds_cong_get_maps(conn);
188 if (ret) {
189 kmem_cache_free(rds_conn_slab, conn);
190 conn = ERR_PTR(ret);
191 goto out;
192 }
193
194 /*
195 * This is where a connection becomes loopback. If *any* RDS sockets
196 * can bind to the destination address then we'd rather the messages
197 * flow through loopback rather than either transport.
198 */
199 loop_trans = rds_trans_get_preferred(net, faddr);
200 if (loop_trans) {
201 rds_trans_put(loop_trans);
202 conn->c_loopback = 1;
203 if (is_outgoing && trans->t_prefer_loopback) {
204 /* "outgoing" connection - and the transport
205 * says it wants the connection handled by the
206 * loopback transport. This is what TCP does.
207 */
208 trans = &rds_loop_transport;
209 }
210 }
211
212 conn->c_trans = trans;
213
214 init_waitqueue_head(&conn->c_hs_waitq);
215 for (i = 0; i < RDS_MPATH_WORKERS; i++) {
216 __rds_conn_path_init(conn, &conn->c_path[i],
217 is_outgoing);
218 conn->c_path[i].cp_index = i;
219 }
220 ret = trans->conn_alloc(conn, gfp);
221 if (ret) {
222 kmem_cache_free(rds_conn_slab, conn);
223 conn = ERR_PTR(ret);
224 goto out;
225 }
226
227 rdsdebug("allocated conn %p for %pI4 -> %pI4 over %s %s\n",
228 conn, &laddr, &faddr,
229 trans->t_name ? trans->t_name : "[unknown]",
230 is_outgoing ? "(outgoing)" : "");
231
232 /*
233 * Since we ran without holding the conn lock, someone could
234 * have created the same conn (either normal or passive) in the
235 * interim. We check while holding the lock. If we won, we complete
236 * init and return our conn. If we lost, we rollback and return the
237 * other one.
238 */
239 spin_lock_irqsave(&rds_conn_lock, flags);
240 if (parent) {
241 /* Creating passive conn */
242 if (parent->c_passive) {
243 trans->conn_free(conn->c_path[0].cp_transport_data);
244 kmem_cache_free(rds_conn_slab, conn);
245 conn = parent->c_passive;
246 } else {
247 parent->c_passive = conn;
248 rds_cong_add_conn(conn);
249 rds_conn_count++;
250 }
251 } else {
252 /* Creating normal conn */
253 struct rds_connection *found;
254
255 found = rds_conn_lookup(net, head, laddr, faddr, trans);
256 if (found) {
257 struct rds_conn_path *cp;
258 int i;
259
260 for (i = 0; i < RDS_MPATH_WORKERS; i++) {
261 cp = &conn->c_path[i];
262 /* The ->conn_alloc invocation may have
263 * allocated resource for all paths, so all
264 * of them may have to be freed here.
265 */
266 if (cp->cp_transport_data)
267 trans->conn_free(cp->cp_transport_data);
268 }
269 kmem_cache_free(rds_conn_slab, conn);
270 conn = found;
271 } else {
272 conn->c_my_gen_num = rds_gen_num;
273 conn->c_peer_gen_num = 0;
274 hlist_add_head_rcu(&conn->c_hash_node, head);
275 rds_cong_add_conn(conn);
276 rds_conn_count++;
277 }
278 }
279 spin_unlock_irqrestore(&rds_conn_lock, flags);
280
281out:
282 return conn;
283}
284
285struct rds_connection *rds_conn_create(struct net *net,
286 __be32 laddr, __be32 faddr,
287 struct rds_transport *trans, gfp_t gfp)
288{
289 return __rds_conn_create(net, laddr, faddr, trans, gfp, 0);
290}
291EXPORT_SYMBOL_GPL(rds_conn_create);
292
293struct rds_connection *rds_conn_create_outgoing(struct net *net,
294 __be32 laddr, __be32 faddr,
295 struct rds_transport *trans, gfp_t gfp)
296{
297 return __rds_conn_create(net, laddr, faddr, trans, gfp, 1);
298}
299EXPORT_SYMBOL_GPL(rds_conn_create_outgoing);
300
301void rds_conn_shutdown(struct rds_conn_path *cp)
302{
303 struct rds_connection *conn = cp->cp_conn;
304
305 /* shut it down unless it's down already */
306 if (!rds_conn_path_transition(cp, RDS_CONN_DOWN, RDS_CONN_DOWN)) {
307 /*
308 * Quiesce the connection mgmt handlers before we start tearing
309 * things down. We don't hold the mutex for the entire
310 * duration of the shutdown operation, else we may be
311 * deadlocking with the CM handler. Instead, the CM event
312 * handler is supposed to check for state DISCONNECTING
313 */
314 mutex_lock(&cp->cp_cm_lock);
315 if (!rds_conn_path_transition(cp, RDS_CONN_UP,
316 RDS_CONN_DISCONNECTING) &&
317 !rds_conn_path_transition(cp, RDS_CONN_ERROR,
318 RDS_CONN_DISCONNECTING)) {
319 rds_conn_path_error(cp,
320 "shutdown called in state %d\n",
321 atomic_read(&cp->cp_state));
322 mutex_unlock(&cp->cp_cm_lock);
323 return;
324 }
325 mutex_unlock(&cp->cp_cm_lock);
326
327 wait_event(cp->cp_waitq,
328 !test_bit(RDS_IN_XMIT, &cp->cp_flags));
329 wait_event(cp->cp_waitq,
330 !test_bit(RDS_RECV_REFILL, &cp->cp_flags));
331
332 conn->c_trans->conn_path_shutdown(cp);
333 rds_conn_path_reset(cp);
334
335 if (!rds_conn_path_transition(cp, RDS_CONN_DISCONNECTING,
336 RDS_CONN_DOWN)) {
337 /* This can happen - eg when we're in the middle of tearing
338 * down the connection, and someone unloads the rds module.
339 * Quite reproduceable with loopback connections.
340 * Mostly harmless.
341 */
342 rds_conn_path_error(cp, "%s: failed to transition "
343 "to state DOWN, current state "
344 "is %d\n", __func__,
345 atomic_read(&cp->cp_state));
346 return;
347 }
348 }
349
350 /* Then reconnect if it's still live.
351 * The passive side of an IB loopback connection is never added
352 * to the conn hash, so we never trigger a reconnect on this
353 * conn - the reconnect is always triggered by the active peer. */
354 cancel_delayed_work_sync(&cp->cp_conn_w);
355 rcu_read_lock();
356 if (!hlist_unhashed(&conn->c_hash_node)) {
357 rcu_read_unlock();
358 rds_queue_reconnect(cp);
359 } else {
360 rcu_read_unlock();
361 }
362}
363
364/* destroy a single rds_conn_path. rds_conn_destroy() iterates over
365 * all paths using rds_conn_path_destroy()
366 */
367static void rds_conn_path_destroy(struct rds_conn_path *cp)
368{
369 struct rds_message *rm, *rtmp;
370
371 if (!cp->cp_transport_data)
372 return;
373
374 rds_conn_path_drop(cp);
375 flush_work(&cp->cp_down_w);
376
377 /* make sure lingering queued work won't try to ref the conn */
378 cancel_delayed_work_sync(&cp->cp_send_w);
379 cancel_delayed_work_sync(&cp->cp_recv_w);
380
381 /* tear down queued messages */
382 list_for_each_entry_safe(rm, rtmp,
383 &cp->cp_send_queue,
384 m_conn_item) {
385 list_del_init(&rm->m_conn_item);
386 BUG_ON(!list_empty(&rm->m_sock_item));
387 rds_message_put(rm);
388 }
389 if (cp->cp_xmit_rm)
390 rds_message_put(cp->cp_xmit_rm);
391
392 cp->cp_conn->c_trans->conn_free(cp->cp_transport_data);
393}
394
395/*
396 * Stop and free a connection.
397 *
398 * This can only be used in very limited circumstances. It assumes that once
399 * the conn has been shutdown that no one else is referencing the connection.
400 * We can only ensure this in the rmmod path in the current code.
401 */
402void rds_conn_destroy(struct rds_connection *conn)
403{
404 unsigned long flags;
405 int i;
406 struct rds_conn_path *cp;
407
408 rdsdebug("freeing conn %p for %pI4 -> "
409 "%pI4\n", conn, &conn->c_laddr,
410 &conn->c_faddr);
411
412 /* Ensure conn will not be scheduled for reconnect */
413 spin_lock_irq(&rds_conn_lock);
414 hlist_del_init_rcu(&conn->c_hash_node);
415 spin_unlock_irq(&rds_conn_lock);
416 synchronize_rcu();
417
418 /* shut the connection down */
419 for (i = 0; i < RDS_MPATH_WORKERS; i++) {
420 cp = &conn->c_path[i];
421 rds_conn_path_destroy(cp);
422 BUG_ON(!list_empty(&cp->cp_retrans));
423 }
424
425 /*
426 * The congestion maps aren't freed up here. They're
427 * freed by rds_cong_exit() after all the connections
428 * have been freed.
429 */
430 rds_cong_remove_conn(conn);
431
432 kmem_cache_free(rds_conn_slab, conn);
433
434 spin_lock_irqsave(&rds_conn_lock, flags);
435 rds_conn_count--;
436 spin_unlock_irqrestore(&rds_conn_lock, flags);
437}
438EXPORT_SYMBOL_GPL(rds_conn_destroy);
439
440static void rds_conn_message_info(struct socket *sock, unsigned int len,
441 struct rds_info_iterator *iter,
442 struct rds_info_lengths *lens,
443 int want_send)
444{
445 struct hlist_head *head;
446 struct list_head *list;
447 struct rds_connection *conn;
448 struct rds_message *rm;
449 unsigned int total = 0;
450 unsigned long flags;
451 size_t i;
452 int j;
453
454 len /= sizeof(struct rds_info_message);
455
456 rcu_read_lock();
457
458 for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
459 i++, head++) {
460 hlist_for_each_entry_rcu(conn, head, c_hash_node) {
461 struct rds_conn_path *cp;
462
463 for (j = 0; j < RDS_MPATH_WORKERS; j++) {
464 cp = &conn->c_path[j];
465 if (want_send)
466 list = &cp->cp_send_queue;
467 else
468 list = &cp->cp_retrans;
469
470 spin_lock_irqsave(&cp->cp_lock, flags);
471
472 /* XXX too lazy to maintain counts.. */
473 list_for_each_entry(rm, list, m_conn_item) {
474 total++;
475 if (total <= len)
476 rds_inc_info_copy(&rm->m_inc,
477 iter,
478 conn->c_laddr,
479 conn->c_faddr,
480 0);
481 }
482
483 spin_unlock_irqrestore(&cp->cp_lock, flags);
484 if (!conn->c_trans->t_mp_capable)
485 break;
486 }
487 }
488 }
489 rcu_read_unlock();
490
491 lens->nr = total;
492 lens->each = sizeof(struct rds_info_message);
493}
494
495static void rds_conn_message_info_send(struct socket *sock, unsigned int len,
496 struct rds_info_iterator *iter,
497 struct rds_info_lengths *lens)
498{
499 rds_conn_message_info(sock, len, iter, lens, 1);
500}
501
502static void rds_conn_message_info_retrans(struct socket *sock,
503 unsigned int len,
504 struct rds_info_iterator *iter,
505 struct rds_info_lengths *lens)
506{
507 rds_conn_message_info(sock, len, iter, lens, 0);
508}
509
510void rds_for_each_conn_info(struct socket *sock, unsigned int len,
511 struct rds_info_iterator *iter,
512 struct rds_info_lengths *lens,
513 int (*visitor)(struct rds_connection *, void *),
514 size_t item_len)
515{
516 uint64_t buffer[(item_len + 7) / 8];
517 struct hlist_head *head;
518 struct rds_connection *conn;
519 size_t i;
520
521 rcu_read_lock();
522
523 lens->nr = 0;
524 lens->each = item_len;
525
526 for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
527 i++, head++) {
528 hlist_for_each_entry_rcu(conn, head, c_hash_node) {
529
530 /* XXX no c_lock usage.. */
531 if (!visitor(conn, buffer))
532 continue;
533
534 /* We copy as much as we can fit in the buffer,
535 * but we count all items so that the caller
536 * can resize the buffer. */
537 if (len >= item_len) {
538 rds_info_copy(iter, buffer, item_len);
539 len -= item_len;
540 }
541 lens->nr++;
542 }
543 }
544 rcu_read_unlock();
545}
546EXPORT_SYMBOL_GPL(rds_for_each_conn_info);
547
548void rds_walk_conn_path_info(struct socket *sock, unsigned int len,
549 struct rds_info_iterator *iter,
550 struct rds_info_lengths *lens,
551 int (*visitor)(struct rds_conn_path *, void *),
552 size_t item_len)
553{
554 u64 buffer[(item_len + 7) / 8];
555 struct hlist_head *head;
556 struct rds_connection *conn;
557 size_t i;
558 int j;
559
560 rcu_read_lock();
561
562 lens->nr = 0;
563 lens->each = item_len;
564
565 for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
566 i++, head++) {
567 hlist_for_each_entry_rcu(conn, head, c_hash_node) {
568 struct rds_conn_path *cp;
569
570 for (j = 0; j < RDS_MPATH_WORKERS; j++) {
571 cp = &conn->c_path[j];
572
573 /* XXX no cp_lock usage.. */
574 if (!visitor(cp, buffer))
575 continue;
576 if (!conn->c_trans->t_mp_capable)
577 break;
578 }
579
580 /* We copy as much as we can fit in the buffer,
581 * but we count all items so that the caller
582 * can resize the buffer.
583 */
584 if (len >= item_len) {
585 rds_info_copy(iter, buffer, item_len);
586 len -= item_len;
587 }
588 lens->nr++;
589 }
590 }
591 rcu_read_unlock();
592}
593
594static int rds_conn_info_visitor(struct rds_conn_path *cp, void *buffer)
595{
596 struct rds_info_connection *cinfo = buffer;
597
598 cinfo->next_tx_seq = cp->cp_next_tx_seq;
599 cinfo->next_rx_seq = cp->cp_next_rx_seq;
600 cinfo->laddr = cp->cp_conn->c_laddr;
601 cinfo->faddr = cp->cp_conn->c_faddr;
602 strncpy(cinfo->transport, cp->cp_conn->c_trans->t_name,
603 sizeof(cinfo->transport));
604 cinfo->flags = 0;
605
606 rds_conn_info_set(cinfo->flags, test_bit(RDS_IN_XMIT, &cp->cp_flags),
607 SENDING);
608 /* XXX Future: return the state rather than these funky bits */
609 rds_conn_info_set(cinfo->flags,
610 atomic_read(&cp->cp_state) == RDS_CONN_CONNECTING,
611 CONNECTING);
612 rds_conn_info_set(cinfo->flags,
613 atomic_read(&cp->cp_state) == RDS_CONN_UP,
614 CONNECTED);
615 return 1;
616}
617
618static void rds_conn_info(struct socket *sock, unsigned int len,
619 struct rds_info_iterator *iter,
620 struct rds_info_lengths *lens)
621{
622 rds_walk_conn_path_info(sock, len, iter, lens,
623 rds_conn_info_visitor,
624 sizeof(struct rds_info_connection));
625}
626
627int rds_conn_init(void)
628{
629 rds_conn_slab = kmem_cache_create("rds_connection",
630 sizeof(struct rds_connection),
631 0, 0, NULL);
632 if (!rds_conn_slab)
633 return -ENOMEM;
634
635 rds_info_register_func(RDS_INFO_CONNECTIONS, rds_conn_info);
636 rds_info_register_func(RDS_INFO_SEND_MESSAGES,
637 rds_conn_message_info_send);
638 rds_info_register_func(RDS_INFO_RETRANS_MESSAGES,
639 rds_conn_message_info_retrans);
640
641 return 0;
642}
643
644void rds_conn_exit(void)
645{
646 rds_loop_exit();
647
648 WARN_ON(!hlist_empty(rds_conn_hash));
649
650 kmem_cache_destroy(rds_conn_slab);
651
652 rds_info_deregister_func(RDS_INFO_CONNECTIONS, rds_conn_info);
653 rds_info_deregister_func(RDS_INFO_SEND_MESSAGES,
654 rds_conn_message_info_send);
655 rds_info_deregister_func(RDS_INFO_RETRANS_MESSAGES,
656 rds_conn_message_info_retrans);
657}
658
659/*
660 * Force a disconnect
661 */
662void rds_conn_path_drop(struct rds_conn_path *cp)
663{
664 atomic_set(&cp->cp_state, RDS_CONN_ERROR);
665 queue_work(rds_wq, &cp->cp_down_w);
666}
667EXPORT_SYMBOL_GPL(rds_conn_path_drop);
668
669void rds_conn_drop(struct rds_connection *conn)
670{
671 WARN_ON(conn->c_trans->t_mp_capable);
672 rds_conn_path_drop(&conn->c_path[0]);
673}
674EXPORT_SYMBOL_GPL(rds_conn_drop);
675
676/*
677 * If the connection is down, trigger a connect. We may have scheduled a
678 * delayed reconnect however - in this case we should not interfere.
679 */
680void rds_conn_path_connect_if_down(struct rds_conn_path *cp)
681{
682 if (rds_conn_path_state(cp) == RDS_CONN_DOWN &&
683 !test_and_set_bit(RDS_RECONNECT_PENDING, &cp->cp_flags))
684 queue_delayed_work(rds_wq, &cp->cp_conn_w, 0);
685}
686EXPORT_SYMBOL_GPL(rds_conn_path_connect_if_down);
687
688void rds_conn_connect_if_down(struct rds_connection *conn)
689{
690 WARN_ON(conn->c_trans->t_mp_capable);
691 rds_conn_path_connect_if_down(&conn->c_path[0]);
692}
693EXPORT_SYMBOL_GPL(rds_conn_connect_if_down);
694
695void
696__rds_conn_path_error(struct rds_conn_path *cp, const char *fmt, ...)
697{
698 va_list ap;
699
700 va_start(ap, fmt);
701 vprintk(fmt, ap);
702 va_end(ap);
703
704 rds_conn_path_drop(cp);
705}