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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 (trans->t_prefer_loopback) {
244 if (likely(is_outgoing)) {
245 /* "outgoing" connection to local address.
246 * Protocol says it wants the connection
247 * handled by the loopback transport.
248 * This is what TCP does.
249 */
250 trans = &rds_loop_transport;
251 } else {
252 /* No transport currently in use
253 * should end up here, but if it
254 * does, reset/destroy the connection.
255 */
256 kmem_cache_free(rds_conn_slab, conn);
257 conn = ERR_PTR(-EOPNOTSUPP);
258 goto out;
259 }
260 }
261 }
262
263 conn->c_trans = trans;
264
265 init_waitqueue_head(&conn->c_hs_waitq);
266 for (i = 0; i < npaths; i++) {
267 __rds_conn_path_init(conn, &conn->c_path[i],
268 is_outgoing);
269 conn->c_path[i].cp_index = i;
270 }
271 rcu_read_lock();
272 if (rds_destroy_pending(conn))
273 ret = -ENETDOWN;
274 else
275 ret = trans->conn_alloc(conn, GFP_ATOMIC);
276 if (ret) {
277 rcu_read_unlock();
278 kfree(conn->c_path);
279 kmem_cache_free(rds_conn_slab, conn);
280 conn = ERR_PTR(ret);
281 goto out;
282 }
283
284 rdsdebug("allocated conn %p for %pI6c -> %pI6c over %s %s\n",
285 conn, laddr, faddr,
286 strnlen(trans->t_name, sizeof(trans->t_name)) ?
287 trans->t_name : "[unknown]", is_outgoing ? "(outgoing)" : "");
288
289 /*
290 * Since we ran without holding the conn lock, someone could
291 * have created the same conn (either normal or passive) in the
292 * interim. We check while holding the lock. If we won, we complete
293 * init and return our conn. If we lost, we rollback and return the
294 * other one.
295 */
296 spin_lock_irqsave(&rds_conn_lock, flags);
297 if (parent) {
298 /* Creating passive conn */
299 if (parent->c_passive) {
300 trans->conn_free(conn->c_path[0].cp_transport_data);
301 kfree(conn->c_path);
302 kmem_cache_free(rds_conn_slab, conn);
303 conn = parent->c_passive;
304 } else {
305 parent->c_passive = conn;
306 rds_cong_add_conn(conn);
307 rds_conn_count++;
308 }
309 } else {
310 /* Creating normal conn */
311 struct rds_connection *found;
312
313 found = rds_conn_lookup(net, head, laddr, faddr, trans,
314 tos, dev_if);
315 if (found) {
316 struct rds_conn_path *cp;
317 int i;
318
319 for (i = 0; i < npaths; i++) {
320 cp = &conn->c_path[i];
321 /* The ->conn_alloc invocation may have
322 * allocated resource for all paths, so all
323 * of them may have to be freed here.
324 */
325 if (cp->cp_transport_data)
326 trans->conn_free(cp->cp_transport_data);
327 }
328 kfree(conn->c_path);
329 kmem_cache_free(rds_conn_slab, conn);
330 conn = found;
331 } else {
332 conn->c_my_gen_num = rds_gen_num;
333 conn->c_peer_gen_num = 0;
334 hlist_add_head_rcu(&conn->c_hash_node, head);
335 rds_cong_add_conn(conn);
336 rds_conn_count++;
337 }
338 }
339 spin_unlock_irqrestore(&rds_conn_lock, flags);
340 rcu_read_unlock();
341
342out:
343 return conn;
344}
345
346struct rds_connection *rds_conn_create(struct net *net,
347 const struct in6_addr *laddr,
348 const struct in6_addr *faddr,
349 struct rds_transport *trans, u8 tos,
350 gfp_t gfp, int dev_if)
351{
352 return __rds_conn_create(net, laddr, faddr, trans, gfp, tos, 0, dev_if);
353}
354EXPORT_SYMBOL_GPL(rds_conn_create);
355
356struct rds_connection *rds_conn_create_outgoing(struct net *net,
357 const struct in6_addr *laddr,
358 const struct in6_addr *faddr,
359 struct rds_transport *trans,
360 u8 tos, gfp_t gfp, int dev_if)
361{
362 return __rds_conn_create(net, laddr, faddr, trans, gfp, tos, 1, dev_if);
363}
364EXPORT_SYMBOL_GPL(rds_conn_create_outgoing);
365
366void rds_conn_shutdown(struct rds_conn_path *cp)
367{
368 struct rds_connection *conn = cp->cp_conn;
369
370 /* shut it down unless it's down already */
371 if (!rds_conn_path_transition(cp, RDS_CONN_DOWN, RDS_CONN_DOWN)) {
372 /*
373 * Quiesce the connection mgmt handlers before we start tearing
374 * things down. We don't hold the mutex for the entire
375 * duration of the shutdown operation, else we may be
376 * deadlocking with the CM handler. Instead, the CM event
377 * handler is supposed to check for state DISCONNECTING
378 */
379 mutex_lock(&cp->cp_cm_lock);
380 if (!rds_conn_path_transition(cp, RDS_CONN_UP,
381 RDS_CONN_DISCONNECTING) &&
382 !rds_conn_path_transition(cp, RDS_CONN_ERROR,
383 RDS_CONN_DISCONNECTING)) {
384 rds_conn_path_error(cp,
385 "shutdown called in state %d\n",
386 atomic_read(&cp->cp_state));
387 mutex_unlock(&cp->cp_cm_lock);
388 return;
389 }
390 mutex_unlock(&cp->cp_cm_lock);
391
392 wait_event(cp->cp_waitq,
393 !test_bit(RDS_IN_XMIT, &cp->cp_flags));
394 wait_event(cp->cp_waitq,
395 !test_bit(RDS_RECV_REFILL, &cp->cp_flags));
396
397 conn->c_trans->conn_path_shutdown(cp);
398 rds_conn_path_reset(cp);
399
400 if (!rds_conn_path_transition(cp, RDS_CONN_DISCONNECTING,
401 RDS_CONN_DOWN) &&
402 !rds_conn_path_transition(cp, RDS_CONN_ERROR,
403 RDS_CONN_DOWN)) {
404 /* This can happen - eg when we're in the middle of tearing
405 * down the connection, and someone unloads the rds module.
406 * Quite reproducible with loopback connections.
407 * Mostly harmless.
408 *
409 * Note that this also happens with rds-tcp because
410 * we could have triggered rds_conn_path_drop in irq
411 * mode from rds_tcp_state change on the receipt of
412 * a FIN, thus we need to recheck for RDS_CONN_ERROR
413 * here.
414 */
415 rds_conn_path_error(cp, "%s: failed to transition "
416 "to state DOWN, current state "
417 "is %d\n", __func__,
418 atomic_read(&cp->cp_state));
419 return;
420 }
421 }
422
423 /* Then reconnect if it's still live.
424 * The passive side of an IB loopback connection is never added
425 * to the conn hash, so we never trigger a reconnect on this
426 * conn - the reconnect is always triggered by the active peer. */
427 cancel_delayed_work_sync(&cp->cp_conn_w);
428 rcu_read_lock();
429 if (!hlist_unhashed(&conn->c_hash_node)) {
430 rcu_read_unlock();
431 rds_queue_reconnect(cp);
432 } else {
433 rcu_read_unlock();
434 }
435}
436
437/* destroy a single rds_conn_path. rds_conn_destroy() iterates over
438 * all paths using rds_conn_path_destroy()
439 */
440static void rds_conn_path_destroy(struct rds_conn_path *cp)
441{
442 struct rds_message *rm, *rtmp;
443
444 if (!cp->cp_transport_data)
445 return;
446
447 /* make sure lingering queued work won't try to ref the conn */
448 cancel_delayed_work_sync(&cp->cp_send_w);
449 cancel_delayed_work_sync(&cp->cp_recv_w);
450
451 rds_conn_path_drop(cp, true);
452 flush_work(&cp->cp_down_w);
453
454 /* tear down queued messages */
455 list_for_each_entry_safe(rm, rtmp,
456 &cp->cp_send_queue,
457 m_conn_item) {
458 list_del_init(&rm->m_conn_item);
459 BUG_ON(!list_empty(&rm->m_sock_item));
460 rds_message_put(rm);
461 }
462 if (cp->cp_xmit_rm)
463 rds_message_put(cp->cp_xmit_rm);
464
465 WARN_ON(delayed_work_pending(&cp->cp_send_w));
466 WARN_ON(delayed_work_pending(&cp->cp_recv_w));
467 WARN_ON(delayed_work_pending(&cp->cp_conn_w));
468 WARN_ON(work_pending(&cp->cp_down_w));
469
470 cp->cp_conn->c_trans->conn_free(cp->cp_transport_data);
471}
472
473/*
474 * Stop and free a connection.
475 *
476 * This can only be used in very limited circumstances. It assumes that once
477 * the conn has been shutdown that no one else is referencing the connection.
478 * We can only ensure this in the rmmod path in the current code.
479 */
480void rds_conn_destroy(struct rds_connection *conn)
481{
482 unsigned long flags;
483 int i;
484 struct rds_conn_path *cp;
485 int npaths = (conn->c_trans->t_mp_capable ? RDS_MPATH_WORKERS : 1);
486
487 rdsdebug("freeing conn %p for %pI4 -> "
488 "%pI4\n", conn, &conn->c_laddr,
489 &conn->c_faddr);
490
491 /* Ensure conn will not be scheduled for reconnect */
492 spin_lock_irq(&rds_conn_lock);
493 hlist_del_init_rcu(&conn->c_hash_node);
494 spin_unlock_irq(&rds_conn_lock);
495 synchronize_rcu();
496
497 /* shut the connection down */
498 for (i = 0; i < npaths; i++) {
499 cp = &conn->c_path[i];
500 rds_conn_path_destroy(cp);
501 BUG_ON(!list_empty(&cp->cp_retrans));
502 }
503
504 /*
505 * The congestion maps aren't freed up here. They're
506 * freed by rds_cong_exit() after all the connections
507 * have been freed.
508 */
509 rds_cong_remove_conn(conn);
510
511 kfree(conn->c_path);
512 kmem_cache_free(rds_conn_slab, conn);
513
514 spin_lock_irqsave(&rds_conn_lock, flags);
515 rds_conn_count--;
516 spin_unlock_irqrestore(&rds_conn_lock, flags);
517}
518EXPORT_SYMBOL_GPL(rds_conn_destroy);
519
520static void __rds_inc_msg_cp(struct rds_incoming *inc,
521 struct rds_info_iterator *iter,
522 void *saddr, void *daddr, int flip, bool isv6)
523{
524#if IS_ENABLED(CONFIG_IPV6)
525 if (isv6)
526 rds6_inc_info_copy(inc, iter, saddr, daddr, flip);
527 else
528#endif
529 rds_inc_info_copy(inc, iter, *(__be32 *)saddr,
530 *(__be32 *)daddr, flip);
531}
532
533static void rds_conn_message_info_cmn(struct socket *sock, unsigned int len,
534 struct rds_info_iterator *iter,
535 struct rds_info_lengths *lens,
536 int want_send, bool isv6)
537{
538 struct hlist_head *head;
539 struct list_head *list;
540 struct rds_connection *conn;
541 struct rds_message *rm;
542 unsigned int total = 0;
543 unsigned long flags;
544 size_t i;
545 int j;
546
547 if (isv6)
548 len /= sizeof(struct rds6_info_message);
549 else
550 len /= sizeof(struct rds_info_message);
551
552 rcu_read_lock();
553
554 for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
555 i++, head++) {
556 hlist_for_each_entry_rcu(conn, head, c_hash_node) {
557 struct rds_conn_path *cp;
558 int npaths;
559
560 if (!isv6 && conn->c_isv6)
561 continue;
562
563 npaths = (conn->c_trans->t_mp_capable ?
564 RDS_MPATH_WORKERS : 1);
565
566 for (j = 0; j < npaths; j++) {
567 cp = &conn->c_path[j];
568 if (want_send)
569 list = &cp->cp_send_queue;
570 else
571 list = &cp->cp_retrans;
572
573 spin_lock_irqsave(&cp->cp_lock, flags);
574
575 /* XXX too lazy to maintain counts.. */
576 list_for_each_entry(rm, list, m_conn_item) {
577 total++;
578 if (total <= len)
579 __rds_inc_msg_cp(&rm->m_inc,
580 iter,
581 &conn->c_laddr,
582 &conn->c_faddr,
583 0, isv6);
584 }
585
586 spin_unlock_irqrestore(&cp->cp_lock, flags);
587 }
588 }
589 }
590 rcu_read_unlock();
591
592 lens->nr = total;
593 if (isv6)
594 lens->each = sizeof(struct rds6_info_message);
595 else
596 lens->each = sizeof(struct rds_info_message);
597}
598
599static void rds_conn_message_info(struct socket *sock, unsigned int len,
600 struct rds_info_iterator *iter,
601 struct rds_info_lengths *lens,
602 int want_send)
603{
604 rds_conn_message_info_cmn(sock, len, iter, lens, want_send, false);
605}
606
607#if IS_ENABLED(CONFIG_IPV6)
608static void rds6_conn_message_info(struct socket *sock, unsigned int len,
609 struct rds_info_iterator *iter,
610 struct rds_info_lengths *lens,
611 int want_send)
612{
613 rds_conn_message_info_cmn(sock, len, iter, lens, want_send, true);
614}
615#endif
616
617static void rds_conn_message_info_send(struct socket *sock, unsigned int len,
618 struct rds_info_iterator *iter,
619 struct rds_info_lengths *lens)
620{
621 rds_conn_message_info(sock, len, iter, lens, 1);
622}
623
624#if IS_ENABLED(CONFIG_IPV6)
625static void rds6_conn_message_info_send(struct socket *sock, unsigned int len,
626 struct rds_info_iterator *iter,
627 struct rds_info_lengths *lens)
628{
629 rds6_conn_message_info(sock, len, iter, lens, 1);
630}
631#endif
632
633static void rds_conn_message_info_retrans(struct socket *sock,
634 unsigned int len,
635 struct rds_info_iterator *iter,
636 struct rds_info_lengths *lens)
637{
638 rds_conn_message_info(sock, len, iter, lens, 0);
639}
640
641#if IS_ENABLED(CONFIG_IPV6)
642static void rds6_conn_message_info_retrans(struct socket *sock,
643 unsigned int len,
644 struct rds_info_iterator *iter,
645 struct rds_info_lengths *lens)
646{
647 rds6_conn_message_info(sock, len, iter, lens, 0);
648}
649#endif
650
651void rds_for_each_conn_info(struct socket *sock, unsigned int len,
652 struct rds_info_iterator *iter,
653 struct rds_info_lengths *lens,
654 int (*visitor)(struct rds_connection *, void *),
655 u64 *buffer,
656 size_t item_len)
657{
658 struct hlist_head *head;
659 struct rds_connection *conn;
660 size_t i;
661
662 rcu_read_lock();
663
664 lens->nr = 0;
665 lens->each = item_len;
666
667 for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
668 i++, head++) {
669 hlist_for_each_entry_rcu(conn, head, c_hash_node) {
670
671 /* XXX no c_lock usage.. */
672 if (!visitor(conn, buffer))
673 continue;
674
675 /* We copy as much as we can fit in the buffer,
676 * but we count all items so that the caller
677 * can resize the buffer. */
678 if (len >= item_len) {
679 rds_info_copy(iter, buffer, item_len);
680 len -= item_len;
681 }
682 lens->nr++;
683 }
684 }
685 rcu_read_unlock();
686}
687EXPORT_SYMBOL_GPL(rds_for_each_conn_info);
688
689static void rds_walk_conn_path_info(struct socket *sock, unsigned int len,
690 struct rds_info_iterator *iter,
691 struct rds_info_lengths *lens,
692 int (*visitor)(struct rds_conn_path *, void *),
693 u64 *buffer,
694 size_t item_len)
695{
696 struct hlist_head *head;
697 struct rds_connection *conn;
698 size_t i;
699
700 rcu_read_lock();
701
702 lens->nr = 0;
703 lens->each = item_len;
704
705 for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
706 i++, head++) {
707 hlist_for_each_entry_rcu(conn, head, c_hash_node) {
708 struct rds_conn_path *cp;
709
710 /* XXX We only copy the information from the first
711 * path for now. The problem is that if there are
712 * more than one underlying paths, we cannot report
713 * information of all of them using the existing
714 * API. For example, there is only one next_tx_seq,
715 * which path's next_tx_seq should we report? It is
716 * a bug in the design of MPRDS.
717 */
718 cp = conn->c_path;
719
720 /* XXX no cp_lock usage.. */
721 if (!visitor(cp, buffer))
722 continue;
723
724 /* We copy as much as we can fit in the buffer,
725 * but we count all items so that the caller
726 * can resize the buffer.
727 */
728 if (len >= item_len) {
729 rds_info_copy(iter, buffer, item_len);
730 len -= item_len;
731 }
732 lens->nr++;
733 }
734 }
735 rcu_read_unlock();
736}
737
738static int rds_conn_info_visitor(struct rds_conn_path *cp, void *buffer)
739{
740 struct rds_info_connection *cinfo = buffer;
741 struct rds_connection *conn = cp->cp_conn;
742
743 if (conn->c_isv6)
744 return 0;
745
746 cinfo->next_tx_seq = cp->cp_next_tx_seq;
747 cinfo->next_rx_seq = cp->cp_next_rx_seq;
748 cinfo->laddr = conn->c_laddr.s6_addr32[3];
749 cinfo->faddr = conn->c_faddr.s6_addr32[3];
750 cinfo->tos = conn->c_tos;
751 strncpy(cinfo->transport, conn->c_trans->t_name,
752 sizeof(cinfo->transport));
753 cinfo->flags = 0;
754
755 rds_conn_info_set(cinfo->flags, test_bit(RDS_IN_XMIT, &cp->cp_flags),
756 SENDING);
757 /* XXX Future: return the state rather than these funky bits */
758 rds_conn_info_set(cinfo->flags,
759 atomic_read(&cp->cp_state) == RDS_CONN_CONNECTING,
760 CONNECTING);
761 rds_conn_info_set(cinfo->flags,
762 atomic_read(&cp->cp_state) == RDS_CONN_UP,
763 CONNECTED);
764 return 1;
765}
766
767#if IS_ENABLED(CONFIG_IPV6)
768static int rds6_conn_info_visitor(struct rds_conn_path *cp, void *buffer)
769{
770 struct rds6_info_connection *cinfo6 = buffer;
771 struct rds_connection *conn = cp->cp_conn;
772
773 cinfo6->next_tx_seq = cp->cp_next_tx_seq;
774 cinfo6->next_rx_seq = cp->cp_next_rx_seq;
775 cinfo6->laddr = conn->c_laddr;
776 cinfo6->faddr = conn->c_faddr;
777 strncpy(cinfo6->transport, conn->c_trans->t_name,
778 sizeof(cinfo6->transport));
779 cinfo6->flags = 0;
780
781 rds_conn_info_set(cinfo6->flags, test_bit(RDS_IN_XMIT, &cp->cp_flags),
782 SENDING);
783 /* XXX Future: return the state rather than these funky bits */
784 rds_conn_info_set(cinfo6->flags,
785 atomic_read(&cp->cp_state) == RDS_CONN_CONNECTING,
786 CONNECTING);
787 rds_conn_info_set(cinfo6->flags,
788 atomic_read(&cp->cp_state) == RDS_CONN_UP,
789 CONNECTED);
790 /* Just return 1 as there is no error case. This is a helper function
791 * for rds_walk_conn_path_info() and it wants a return value.
792 */
793 return 1;
794}
795#endif
796
797static void rds_conn_info(struct socket *sock, unsigned int len,
798 struct rds_info_iterator *iter,
799 struct rds_info_lengths *lens)
800{
801 u64 buffer[(sizeof(struct rds_info_connection) + 7) / 8];
802
803 rds_walk_conn_path_info(sock, len, iter, lens,
804 rds_conn_info_visitor,
805 buffer,
806 sizeof(struct rds_info_connection));
807}
808
809#if IS_ENABLED(CONFIG_IPV6)
810static void rds6_conn_info(struct socket *sock, unsigned int len,
811 struct rds_info_iterator *iter,
812 struct rds_info_lengths *lens)
813{
814 u64 buffer[(sizeof(struct rds6_info_connection) + 7) / 8];
815
816 rds_walk_conn_path_info(sock, len, iter, lens,
817 rds6_conn_info_visitor,
818 buffer,
819 sizeof(struct rds6_info_connection));
820}
821#endif
822
823int rds_conn_init(void)
824{
825 int ret;
826
827 ret = rds_loop_net_init(); /* register pernet callback */
828 if (ret)
829 return ret;
830
831 rds_conn_slab = kmem_cache_create("rds_connection",
832 sizeof(struct rds_connection),
833 0, 0, NULL);
834 if (!rds_conn_slab) {
835 rds_loop_net_exit();
836 return -ENOMEM;
837 }
838
839 rds_info_register_func(RDS_INFO_CONNECTIONS, rds_conn_info);
840 rds_info_register_func(RDS_INFO_SEND_MESSAGES,
841 rds_conn_message_info_send);
842 rds_info_register_func(RDS_INFO_RETRANS_MESSAGES,
843 rds_conn_message_info_retrans);
844#if IS_ENABLED(CONFIG_IPV6)
845 rds_info_register_func(RDS6_INFO_CONNECTIONS, rds6_conn_info);
846 rds_info_register_func(RDS6_INFO_SEND_MESSAGES,
847 rds6_conn_message_info_send);
848 rds_info_register_func(RDS6_INFO_RETRANS_MESSAGES,
849 rds6_conn_message_info_retrans);
850#endif
851 return 0;
852}
853
854void rds_conn_exit(void)
855{
856 rds_loop_net_exit(); /* unregister pernet callback */
857 rds_loop_exit();
858
859 WARN_ON(!hlist_empty(rds_conn_hash));
860
861 kmem_cache_destroy(rds_conn_slab);
862
863 rds_info_deregister_func(RDS_INFO_CONNECTIONS, rds_conn_info);
864 rds_info_deregister_func(RDS_INFO_SEND_MESSAGES,
865 rds_conn_message_info_send);
866 rds_info_deregister_func(RDS_INFO_RETRANS_MESSAGES,
867 rds_conn_message_info_retrans);
868#if IS_ENABLED(CONFIG_IPV6)
869 rds_info_deregister_func(RDS6_INFO_CONNECTIONS, rds6_conn_info);
870 rds_info_deregister_func(RDS6_INFO_SEND_MESSAGES,
871 rds6_conn_message_info_send);
872 rds_info_deregister_func(RDS6_INFO_RETRANS_MESSAGES,
873 rds6_conn_message_info_retrans);
874#endif
875}
876
877/*
878 * Force a disconnect
879 */
880void rds_conn_path_drop(struct rds_conn_path *cp, bool destroy)
881{
882 atomic_set(&cp->cp_state, RDS_CONN_ERROR);
883
884 rcu_read_lock();
885 if (!destroy && rds_destroy_pending(cp->cp_conn)) {
886 rcu_read_unlock();
887 return;
888 }
889 queue_work(rds_wq, &cp->cp_down_w);
890 rcu_read_unlock();
891}
892EXPORT_SYMBOL_GPL(rds_conn_path_drop);
893
894void rds_conn_drop(struct rds_connection *conn)
895{
896 WARN_ON(conn->c_trans->t_mp_capable);
897 rds_conn_path_drop(&conn->c_path[0], false);
898}
899EXPORT_SYMBOL_GPL(rds_conn_drop);
900
901/*
902 * If the connection is down, trigger a connect. We may have scheduled a
903 * delayed reconnect however - in this case we should not interfere.
904 */
905void rds_conn_path_connect_if_down(struct rds_conn_path *cp)
906{
907 rcu_read_lock();
908 if (rds_destroy_pending(cp->cp_conn)) {
909 rcu_read_unlock();
910 return;
911 }
912 if (rds_conn_path_state(cp) == RDS_CONN_DOWN &&
913 !test_and_set_bit(RDS_RECONNECT_PENDING, &cp->cp_flags))
914 queue_delayed_work(rds_wq, &cp->cp_conn_w, 0);
915 rcu_read_unlock();
916}
917EXPORT_SYMBOL_GPL(rds_conn_path_connect_if_down);
918
919/* Check connectivity of all paths
920 */
921void rds_check_all_paths(struct rds_connection *conn)
922{
923 int i = 0;
924
925 do {
926 rds_conn_path_connect_if_down(&conn->c_path[i]);
927 } while (++i < conn->c_npaths);
928}
929
930void rds_conn_connect_if_down(struct rds_connection *conn)
931{
932 WARN_ON(conn->c_trans->t_mp_capable);
933 rds_conn_path_connect_if_down(&conn->c_path[0]);
934}
935EXPORT_SYMBOL_GPL(rds_conn_connect_if_down);
936
937void
938__rds_conn_path_error(struct rds_conn_path *cp, const char *fmt, ...)
939{
940 va_list ap;
941
942 va_start(ap, fmt);
943 vprintk(fmt, ap);
944 va_end(ap);
945
946 rds_conn_path_drop(cp, false);
947}
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 <net/inet_hashtables.h>
37
38#include "rds.h"
39#include "loop.h"
40
41#define RDS_CONNECTION_HASH_BITS 12
42#define RDS_CONNECTION_HASH_ENTRIES (1 << RDS_CONNECTION_HASH_BITS)
43#define RDS_CONNECTION_HASH_MASK (RDS_CONNECTION_HASH_ENTRIES - 1)
44
45/* converting this to RCU is a chore for another day.. */
46static DEFINE_SPINLOCK(rds_conn_lock);
47static unsigned long rds_conn_count;
48static struct hlist_head rds_conn_hash[RDS_CONNECTION_HASH_ENTRIES];
49static struct kmem_cache *rds_conn_slab;
50
51static struct hlist_head *rds_conn_bucket(__be32 laddr, __be32 faddr)
52{
53 /* Pass NULL, don't need struct net for hash */
54 unsigned long hash = inet_ehashfn(NULL,
55 be32_to_cpu(laddr), 0,
56 be32_to_cpu(faddr), 0);
57 return &rds_conn_hash[hash & RDS_CONNECTION_HASH_MASK];
58}
59
60#define rds_conn_info_set(var, test, suffix) do { \
61 if (test) \
62 var |= RDS_INFO_CONNECTION_FLAG_##suffix; \
63} while (0)
64
65/* rcu read lock must be held or the connection spinlock */
66static struct rds_connection *rds_conn_lookup(struct hlist_head *head,
67 __be32 laddr, __be32 faddr,
68 struct rds_transport *trans)
69{
70 struct rds_connection *conn, *ret = NULL;
71 struct hlist_node *pos;
72
73 hlist_for_each_entry_rcu(conn, pos, head, c_hash_node) {
74 if (conn->c_faddr == faddr && conn->c_laddr == laddr &&
75 conn->c_trans == trans) {
76 ret = conn;
77 break;
78 }
79 }
80 rdsdebug("returning conn %p for %pI4 -> %pI4\n", ret,
81 &laddr, &faddr);
82 return ret;
83}
84
85/*
86 * This is called by transports as they're bringing down a connection.
87 * It clears partial message state so that the transport can start sending
88 * and receiving over this connection again in the future. It is up to
89 * the transport to have serialized this call with its send and recv.
90 */
91static void rds_conn_reset(struct rds_connection *conn)
92{
93 rdsdebug("connection %pI4 to %pI4 reset\n",
94 &conn->c_laddr, &conn->c_faddr);
95
96 rds_stats_inc(s_conn_reset);
97 rds_send_reset(conn);
98 conn->c_flags = 0;
99
100 /* Do not clear next_rx_seq here, else we cannot distinguish
101 * retransmitted packets from new packets, and will hand all
102 * of them to the application. That is not consistent with the
103 * reliability guarantees of RDS. */
104}
105
106/*
107 * There is only every one 'conn' for a given pair of addresses in the
108 * system at a time. They contain messages to be retransmitted and so
109 * span the lifetime of the actual underlying transport connections.
110 *
111 * For now they are not garbage collected once they're created. They
112 * are torn down as the module is removed, if ever.
113 */
114static struct rds_connection *__rds_conn_create(__be32 laddr, __be32 faddr,
115 struct rds_transport *trans, gfp_t gfp,
116 int is_outgoing)
117{
118 struct rds_connection *conn, *parent = NULL;
119 struct hlist_head *head = rds_conn_bucket(laddr, faddr);
120 struct rds_transport *loop_trans;
121 unsigned long flags;
122 int ret;
123
124 rcu_read_lock();
125 conn = rds_conn_lookup(head, laddr, faddr, trans);
126 if (conn && conn->c_loopback && conn->c_trans != &rds_loop_transport &&
127 !is_outgoing) {
128 /* This is a looped back IB connection, and we're
129 * called by the code handling the incoming connect.
130 * We need a second connection object into which we
131 * can stick the other QP. */
132 parent = conn;
133 conn = parent->c_passive;
134 }
135 rcu_read_unlock();
136 if (conn)
137 goto out;
138
139 conn = kmem_cache_zalloc(rds_conn_slab, gfp);
140 if (!conn) {
141 conn = ERR_PTR(-ENOMEM);
142 goto out;
143 }
144
145 INIT_HLIST_NODE(&conn->c_hash_node);
146 conn->c_laddr = laddr;
147 conn->c_faddr = faddr;
148 spin_lock_init(&conn->c_lock);
149 conn->c_next_tx_seq = 1;
150
151 init_waitqueue_head(&conn->c_waitq);
152 INIT_LIST_HEAD(&conn->c_send_queue);
153 INIT_LIST_HEAD(&conn->c_retrans);
154
155 ret = rds_cong_get_maps(conn);
156 if (ret) {
157 kmem_cache_free(rds_conn_slab, conn);
158 conn = ERR_PTR(ret);
159 goto out;
160 }
161
162 /*
163 * This is where a connection becomes loopback. If *any* RDS sockets
164 * can bind to the destination address then we'd rather the messages
165 * flow through loopback rather than either transport.
166 */
167 loop_trans = rds_trans_get_preferred(faddr);
168 if (loop_trans) {
169 rds_trans_put(loop_trans);
170 conn->c_loopback = 1;
171 if (is_outgoing && trans->t_prefer_loopback) {
172 /* "outgoing" connection - and the transport
173 * says it wants the connection handled by the
174 * loopback transport. This is what TCP does.
175 */
176 trans = &rds_loop_transport;
177 }
178 }
179
180 conn->c_trans = trans;
181
182 ret = trans->conn_alloc(conn, gfp);
183 if (ret) {
184 kmem_cache_free(rds_conn_slab, conn);
185 conn = ERR_PTR(ret);
186 goto out;
187 }
188
189 atomic_set(&conn->c_state, RDS_CONN_DOWN);
190 conn->c_reconnect_jiffies = 0;
191 INIT_DELAYED_WORK(&conn->c_send_w, rds_send_worker);
192 INIT_DELAYED_WORK(&conn->c_recv_w, rds_recv_worker);
193 INIT_DELAYED_WORK(&conn->c_conn_w, rds_connect_worker);
194 INIT_WORK(&conn->c_down_w, rds_shutdown_worker);
195 mutex_init(&conn->c_cm_lock);
196 conn->c_flags = 0;
197
198 rdsdebug("allocated conn %p for %pI4 -> %pI4 over %s %s\n",
199 conn, &laddr, &faddr,
200 trans->t_name ? trans->t_name : "[unknown]",
201 is_outgoing ? "(outgoing)" : "");
202
203 /*
204 * Since we ran without holding the conn lock, someone could
205 * have created the same conn (either normal or passive) in the
206 * interim. We check while holding the lock. If we won, we complete
207 * init and return our conn. If we lost, we rollback and return the
208 * other one.
209 */
210 spin_lock_irqsave(&rds_conn_lock, flags);
211 if (parent) {
212 /* Creating passive conn */
213 if (parent->c_passive) {
214 trans->conn_free(conn->c_transport_data);
215 kmem_cache_free(rds_conn_slab, conn);
216 conn = parent->c_passive;
217 } else {
218 parent->c_passive = conn;
219 rds_cong_add_conn(conn);
220 rds_conn_count++;
221 }
222 } else {
223 /* Creating normal conn */
224 struct rds_connection *found;
225
226 found = rds_conn_lookup(head, laddr, faddr, trans);
227 if (found) {
228 trans->conn_free(conn->c_transport_data);
229 kmem_cache_free(rds_conn_slab, conn);
230 conn = found;
231 } else {
232 hlist_add_head_rcu(&conn->c_hash_node, head);
233 rds_cong_add_conn(conn);
234 rds_conn_count++;
235 }
236 }
237 spin_unlock_irqrestore(&rds_conn_lock, flags);
238
239out:
240 return conn;
241}
242
243struct rds_connection *rds_conn_create(__be32 laddr, __be32 faddr,
244 struct rds_transport *trans, gfp_t gfp)
245{
246 return __rds_conn_create(laddr, faddr, trans, gfp, 0);
247}
248EXPORT_SYMBOL_GPL(rds_conn_create);
249
250struct rds_connection *rds_conn_create_outgoing(__be32 laddr, __be32 faddr,
251 struct rds_transport *trans, gfp_t gfp)
252{
253 return __rds_conn_create(laddr, faddr, trans, gfp, 1);
254}
255EXPORT_SYMBOL_GPL(rds_conn_create_outgoing);
256
257void rds_conn_shutdown(struct rds_connection *conn)
258{
259 /* shut it down unless it's down already */
260 if (!rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_DOWN)) {
261 /*
262 * Quiesce the connection mgmt handlers before we start tearing
263 * things down. We don't hold the mutex for the entire
264 * duration of the shutdown operation, else we may be
265 * deadlocking with the CM handler. Instead, the CM event
266 * handler is supposed to check for state DISCONNECTING
267 */
268 mutex_lock(&conn->c_cm_lock);
269 if (!rds_conn_transition(conn, RDS_CONN_UP, RDS_CONN_DISCONNECTING)
270 && !rds_conn_transition(conn, RDS_CONN_ERROR, RDS_CONN_DISCONNECTING)) {
271 rds_conn_error(conn, "shutdown called in state %d\n",
272 atomic_read(&conn->c_state));
273 mutex_unlock(&conn->c_cm_lock);
274 return;
275 }
276 mutex_unlock(&conn->c_cm_lock);
277
278 wait_event(conn->c_waitq,
279 !test_bit(RDS_IN_XMIT, &conn->c_flags));
280
281 conn->c_trans->conn_shutdown(conn);
282 rds_conn_reset(conn);
283
284 if (!rds_conn_transition(conn, RDS_CONN_DISCONNECTING, RDS_CONN_DOWN)) {
285 /* This can happen - eg when we're in the middle of tearing
286 * down the connection, and someone unloads the rds module.
287 * Quite reproduceable with loopback connections.
288 * Mostly harmless.
289 */
290 rds_conn_error(conn,
291 "%s: failed to transition to state DOWN, "
292 "current state is %d\n",
293 __func__,
294 atomic_read(&conn->c_state));
295 return;
296 }
297 }
298
299 /* Then reconnect if it's still live.
300 * The passive side of an IB loopback connection is never added
301 * to the conn hash, so we never trigger a reconnect on this
302 * conn - the reconnect is always triggered by the active peer. */
303 cancel_delayed_work_sync(&conn->c_conn_w);
304 rcu_read_lock();
305 if (!hlist_unhashed(&conn->c_hash_node)) {
306 rcu_read_unlock();
307 rds_queue_reconnect(conn);
308 } else {
309 rcu_read_unlock();
310 }
311}
312
313/*
314 * Stop and free a connection.
315 *
316 * This can only be used in very limited circumstances. It assumes that once
317 * the conn has been shutdown that no one else is referencing the connection.
318 * We can only ensure this in the rmmod path in the current code.
319 */
320void rds_conn_destroy(struct rds_connection *conn)
321{
322 struct rds_message *rm, *rtmp;
323 unsigned long flags;
324
325 rdsdebug("freeing conn %p for %pI4 -> "
326 "%pI4\n", conn, &conn->c_laddr,
327 &conn->c_faddr);
328
329 /* Ensure conn will not be scheduled for reconnect */
330 spin_lock_irq(&rds_conn_lock);
331 hlist_del_init_rcu(&conn->c_hash_node);
332 spin_unlock_irq(&rds_conn_lock);
333 synchronize_rcu();
334
335 /* shut the connection down */
336 rds_conn_drop(conn);
337 flush_work(&conn->c_down_w);
338
339 /* make sure lingering queued work won't try to ref the conn */
340 cancel_delayed_work_sync(&conn->c_send_w);
341 cancel_delayed_work_sync(&conn->c_recv_w);
342
343 /* tear down queued messages */
344 list_for_each_entry_safe(rm, rtmp,
345 &conn->c_send_queue,
346 m_conn_item) {
347 list_del_init(&rm->m_conn_item);
348 BUG_ON(!list_empty(&rm->m_sock_item));
349 rds_message_put(rm);
350 }
351 if (conn->c_xmit_rm)
352 rds_message_put(conn->c_xmit_rm);
353
354 conn->c_trans->conn_free(conn->c_transport_data);
355
356 /*
357 * The congestion maps aren't freed up here. They're
358 * freed by rds_cong_exit() after all the connections
359 * have been freed.
360 */
361 rds_cong_remove_conn(conn);
362
363 BUG_ON(!list_empty(&conn->c_retrans));
364 kmem_cache_free(rds_conn_slab, conn);
365
366 spin_lock_irqsave(&rds_conn_lock, flags);
367 rds_conn_count--;
368 spin_unlock_irqrestore(&rds_conn_lock, flags);
369}
370EXPORT_SYMBOL_GPL(rds_conn_destroy);
371
372static void rds_conn_message_info(struct socket *sock, unsigned int len,
373 struct rds_info_iterator *iter,
374 struct rds_info_lengths *lens,
375 int want_send)
376{
377 struct hlist_head *head;
378 struct hlist_node *pos;
379 struct list_head *list;
380 struct rds_connection *conn;
381 struct rds_message *rm;
382 unsigned int total = 0;
383 unsigned long flags;
384 size_t i;
385
386 len /= sizeof(struct rds_info_message);
387
388 rcu_read_lock();
389
390 for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
391 i++, head++) {
392 hlist_for_each_entry_rcu(conn, pos, head, c_hash_node) {
393 if (want_send)
394 list = &conn->c_send_queue;
395 else
396 list = &conn->c_retrans;
397
398 spin_lock_irqsave(&conn->c_lock, flags);
399
400 /* XXX too lazy to maintain counts.. */
401 list_for_each_entry(rm, list, m_conn_item) {
402 total++;
403 if (total <= len)
404 rds_inc_info_copy(&rm->m_inc, iter,
405 conn->c_laddr,
406 conn->c_faddr, 0);
407 }
408
409 spin_unlock_irqrestore(&conn->c_lock, flags);
410 }
411 }
412 rcu_read_unlock();
413
414 lens->nr = total;
415 lens->each = sizeof(struct rds_info_message);
416}
417
418static void rds_conn_message_info_send(struct socket *sock, unsigned int len,
419 struct rds_info_iterator *iter,
420 struct rds_info_lengths *lens)
421{
422 rds_conn_message_info(sock, len, iter, lens, 1);
423}
424
425static void rds_conn_message_info_retrans(struct socket *sock,
426 unsigned int len,
427 struct rds_info_iterator *iter,
428 struct rds_info_lengths *lens)
429{
430 rds_conn_message_info(sock, len, iter, lens, 0);
431}
432
433void rds_for_each_conn_info(struct socket *sock, unsigned int len,
434 struct rds_info_iterator *iter,
435 struct rds_info_lengths *lens,
436 int (*visitor)(struct rds_connection *, void *),
437 size_t item_len)
438{
439 uint64_t buffer[(item_len + 7) / 8];
440 struct hlist_head *head;
441 struct hlist_node *pos;
442 struct rds_connection *conn;
443 size_t i;
444
445 rcu_read_lock();
446
447 lens->nr = 0;
448 lens->each = item_len;
449
450 for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
451 i++, head++) {
452 hlist_for_each_entry_rcu(conn, pos, head, c_hash_node) {
453
454 /* XXX no c_lock usage.. */
455 if (!visitor(conn, buffer))
456 continue;
457
458 /* We copy as much as we can fit in the buffer,
459 * but we count all items so that the caller
460 * can resize the buffer. */
461 if (len >= item_len) {
462 rds_info_copy(iter, buffer, item_len);
463 len -= item_len;
464 }
465 lens->nr++;
466 }
467 }
468 rcu_read_unlock();
469}
470EXPORT_SYMBOL_GPL(rds_for_each_conn_info);
471
472static int rds_conn_info_visitor(struct rds_connection *conn,
473 void *buffer)
474{
475 struct rds_info_connection *cinfo = buffer;
476
477 cinfo->next_tx_seq = conn->c_next_tx_seq;
478 cinfo->next_rx_seq = conn->c_next_rx_seq;
479 cinfo->laddr = conn->c_laddr;
480 cinfo->faddr = conn->c_faddr;
481 strncpy(cinfo->transport, conn->c_trans->t_name,
482 sizeof(cinfo->transport));
483 cinfo->flags = 0;
484
485 rds_conn_info_set(cinfo->flags, test_bit(RDS_IN_XMIT, &conn->c_flags),
486 SENDING);
487 /* XXX Future: return the state rather than these funky bits */
488 rds_conn_info_set(cinfo->flags,
489 atomic_read(&conn->c_state) == RDS_CONN_CONNECTING,
490 CONNECTING);
491 rds_conn_info_set(cinfo->flags,
492 atomic_read(&conn->c_state) == RDS_CONN_UP,
493 CONNECTED);
494 return 1;
495}
496
497static void rds_conn_info(struct socket *sock, unsigned int len,
498 struct rds_info_iterator *iter,
499 struct rds_info_lengths *lens)
500{
501 rds_for_each_conn_info(sock, len, iter, lens,
502 rds_conn_info_visitor,
503 sizeof(struct rds_info_connection));
504}
505
506int rds_conn_init(void)
507{
508 rds_conn_slab = kmem_cache_create("rds_connection",
509 sizeof(struct rds_connection),
510 0, 0, NULL);
511 if (!rds_conn_slab)
512 return -ENOMEM;
513
514 rds_info_register_func(RDS_INFO_CONNECTIONS, rds_conn_info);
515 rds_info_register_func(RDS_INFO_SEND_MESSAGES,
516 rds_conn_message_info_send);
517 rds_info_register_func(RDS_INFO_RETRANS_MESSAGES,
518 rds_conn_message_info_retrans);
519
520 return 0;
521}
522
523void rds_conn_exit(void)
524{
525 rds_loop_exit();
526
527 WARN_ON(!hlist_empty(rds_conn_hash));
528
529 kmem_cache_destroy(rds_conn_slab);
530
531 rds_info_deregister_func(RDS_INFO_CONNECTIONS, rds_conn_info);
532 rds_info_deregister_func(RDS_INFO_SEND_MESSAGES,
533 rds_conn_message_info_send);
534 rds_info_deregister_func(RDS_INFO_RETRANS_MESSAGES,
535 rds_conn_message_info_retrans);
536}
537
538/*
539 * Force a disconnect
540 */
541void rds_conn_drop(struct rds_connection *conn)
542{
543 atomic_set(&conn->c_state, RDS_CONN_ERROR);
544 queue_work(rds_wq, &conn->c_down_w);
545}
546EXPORT_SYMBOL_GPL(rds_conn_drop);
547
548/*
549 * If the connection is down, trigger a connect. We may have scheduled a
550 * delayed reconnect however - in this case we should not interfere.
551 */
552void rds_conn_connect_if_down(struct rds_connection *conn)
553{
554 if (rds_conn_state(conn) == RDS_CONN_DOWN &&
555 !test_and_set_bit(RDS_RECONNECT_PENDING, &conn->c_flags))
556 queue_delayed_work(rds_wq, &conn->c_conn_w, 0);
557}
558EXPORT_SYMBOL_GPL(rds_conn_connect_if_down);
559
560/*
561 * An error occurred on the connection
562 */
563void
564__rds_conn_error(struct rds_connection *conn, const char *fmt, ...)
565{
566 va_list ap;
567
568 va_start(ap, fmt);
569 vprintk(fmt, ap);
570 va_end(ap);
571
572 rds_conn_drop(conn);
573}