Loading...
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, 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 kfree(conn->c_path);
257 kmem_cache_free(rds_conn_slab, conn);
258 conn = ERR_PTR(-EOPNOTSUPP);
259 goto out;
260 }
261 }
262 }
263
264 conn->c_trans = trans;
265
266 init_waitqueue_head(&conn->c_hs_waitq);
267 for (i = 0; i < npaths; i++) {
268 __rds_conn_path_init(conn, &conn->c_path[i],
269 is_outgoing);
270 conn->c_path[i].cp_index = i;
271 }
272 rcu_read_lock();
273 if (rds_destroy_pending(conn))
274 ret = -ENETDOWN;
275 else
276 ret = trans->conn_alloc(conn, GFP_ATOMIC);
277 if (ret) {
278 rcu_read_unlock();
279 kfree(conn->c_path);
280 kmem_cache_free(rds_conn_slab, conn);
281 conn = ERR_PTR(ret);
282 goto out;
283 }
284
285 rdsdebug("allocated conn %p for %pI6c -> %pI6c over %s %s\n",
286 conn, laddr, faddr,
287 strnlen(trans->t_name, sizeof(trans->t_name)) ?
288 trans->t_name : "[unknown]", is_outgoing ? "(outgoing)" : "");
289
290 /*
291 * Since we ran without holding the conn lock, someone could
292 * have created the same conn (either normal or passive) in the
293 * interim. We check while holding the lock. If we won, we complete
294 * init and return our conn. If we lost, we rollback and return the
295 * other one.
296 */
297 spin_lock_irqsave(&rds_conn_lock, flags);
298 if (parent) {
299 /* Creating passive conn */
300 if (parent->c_passive) {
301 trans->conn_free(conn->c_path[0].cp_transport_data);
302 kfree(conn->c_path);
303 kmem_cache_free(rds_conn_slab, conn);
304 conn = parent->c_passive;
305 } else {
306 parent->c_passive = conn;
307 rds_cong_add_conn(conn);
308 rds_conn_count++;
309 }
310 } else {
311 /* Creating normal conn */
312 struct rds_connection *found;
313
314 found = rds_conn_lookup(net, head, laddr, faddr, trans,
315 tos, dev_if);
316 if (found) {
317 struct rds_conn_path *cp;
318 int i;
319
320 for (i = 0; i < npaths; i++) {
321 cp = &conn->c_path[i];
322 /* The ->conn_alloc invocation may have
323 * allocated resource for all paths, so all
324 * of them may have to be freed here.
325 */
326 if (cp->cp_transport_data)
327 trans->conn_free(cp->cp_transport_data);
328 }
329 kfree(conn->c_path);
330 kmem_cache_free(rds_conn_slab, conn);
331 conn = found;
332 } else {
333 conn->c_my_gen_num = rds_gen_num;
334 conn->c_peer_gen_num = 0;
335 hlist_add_head_rcu(&conn->c_hash_node, head);
336 rds_cong_add_conn(conn);
337 rds_conn_count++;
338 }
339 }
340 spin_unlock_irqrestore(&rds_conn_lock, flags);
341 rcu_read_unlock();
342
343out:
344 return conn;
345}
346
347struct rds_connection *rds_conn_create(struct net *net,
348 const struct in6_addr *laddr,
349 const struct in6_addr *faddr,
350 struct rds_transport *trans, u8 tos,
351 gfp_t gfp, int dev_if)
352{
353 return __rds_conn_create(net, laddr, faddr, trans, gfp, tos, 0, dev_if);
354}
355EXPORT_SYMBOL_GPL(rds_conn_create);
356
357struct rds_connection *rds_conn_create_outgoing(struct net *net,
358 const struct in6_addr *laddr,
359 const struct in6_addr *faddr,
360 struct rds_transport *trans,
361 u8 tos, gfp_t gfp, int dev_if)
362{
363 return __rds_conn_create(net, laddr, faddr, trans, gfp, tos, 1, dev_if);
364}
365EXPORT_SYMBOL_GPL(rds_conn_create_outgoing);
366
367void rds_conn_shutdown(struct rds_conn_path *cp)
368{
369 struct rds_connection *conn = cp->cp_conn;
370
371 /* shut it down unless it's down already */
372 if (!rds_conn_path_transition(cp, RDS_CONN_DOWN, RDS_CONN_DOWN)) {
373 /*
374 * Quiesce the connection mgmt handlers before we start tearing
375 * things down. We don't hold the mutex for the entire
376 * duration of the shutdown operation, else we may be
377 * deadlocking with the CM handler. Instead, the CM event
378 * handler is supposed to check for state DISCONNECTING
379 */
380 mutex_lock(&cp->cp_cm_lock);
381 if (!rds_conn_path_transition(cp, RDS_CONN_UP,
382 RDS_CONN_DISCONNECTING) &&
383 !rds_conn_path_transition(cp, RDS_CONN_ERROR,
384 RDS_CONN_DISCONNECTING)) {
385 rds_conn_path_error(cp,
386 "shutdown called in state %d\n",
387 atomic_read(&cp->cp_state));
388 mutex_unlock(&cp->cp_cm_lock);
389 return;
390 }
391 mutex_unlock(&cp->cp_cm_lock);
392
393 wait_event(cp->cp_waitq,
394 !test_bit(RDS_IN_XMIT, &cp->cp_flags));
395 wait_event(cp->cp_waitq,
396 !test_bit(RDS_RECV_REFILL, &cp->cp_flags));
397
398 conn->c_trans->conn_path_shutdown(cp);
399 rds_conn_path_reset(cp);
400
401 if (!rds_conn_path_transition(cp, RDS_CONN_DISCONNECTING,
402 RDS_CONN_DOWN) &&
403 !rds_conn_path_transition(cp, RDS_CONN_ERROR,
404 RDS_CONN_DOWN)) {
405 /* This can happen - eg when we're in the middle of tearing
406 * down the connection, and someone unloads the rds module.
407 * Quite reproducible with loopback connections.
408 * Mostly harmless.
409 *
410 * Note that this also happens with rds-tcp because
411 * we could have triggered rds_conn_path_drop in irq
412 * mode from rds_tcp_state change on the receipt of
413 * a FIN, thus we need to recheck for RDS_CONN_ERROR
414 * here.
415 */
416 rds_conn_path_error(cp, "%s: failed to transition "
417 "to state DOWN, current state "
418 "is %d\n", __func__,
419 atomic_read(&cp->cp_state));
420 return;
421 }
422 }
423
424 /* Then reconnect if it's still live.
425 * The passive side of an IB loopback connection is never added
426 * to the conn hash, so we never trigger a reconnect on this
427 * conn - the reconnect is always triggered by the active peer. */
428 cancel_delayed_work_sync(&cp->cp_conn_w);
429 rcu_read_lock();
430 if (!hlist_unhashed(&conn->c_hash_node)) {
431 rcu_read_unlock();
432 rds_queue_reconnect(cp);
433 } else {
434 rcu_read_unlock();
435 }
436}
437
438/* destroy a single rds_conn_path. rds_conn_destroy() iterates over
439 * all paths using rds_conn_path_destroy()
440 */
441static void rds_conn_path_destroy(struct rds_conn_path *cp)
442{
443 struct rds_message *rm, *rtmp;
444
445 if (!cp->cp_transport_data)
446 return;
447
448 /* make sure lingering queued work won't try to ref the conn */
449 cancel_delayed_work_sync(&cp->cp_send_w);
450 cancel_delayed_work_sync(&cp->cp_recv_w);
451
452 rds_conn_path_drop(cp, true);
453 flush_work(&cp->cp_down_w);
454
455 /* tear down queued messages */
456 list_for_each_entry_safe(rm, rtmp,
457 &cp->cp_send_queue,
458 m_conn_item) {
459 list_del_init(&rm->m_conn_item);
460 BUG_ON(!list_empty(&rm->m_sock_item));
461 rds_message_put(rm);
462 }
463 if (cp->cp_xmit_rm)
464 rds_message_put(cp->cp_xmit_rm);
465
466 WARN_ON(delayed_work_pending(&cp->cp_send_w));
467 WARN_ON(delayed_work_pending(&cp->cp_recv_w));
468 WARN_ON(delayed_work_pending(&cp->cp_conn_w));
469 WARN_ON(work_pending(&cp->cp_down_w));
470
471 cp->cp_conn->c_trans->conn_free(cp->cp_transport_data);
472}
473
474/*
475 * Stop and free a connection.
476 *
477 * This can only be used in very limited circumstances. It assumes that once
478 * the conn has been shutdown that no one else is referencing the connection.
479 * We can only ensure this in the rmmod path in the current code.
480 */
481void rds_conn_destroy(struct rds_connection *conn)
482{
483 unsigned long flags;
484 int i;
485 struct rds_conn_path *cp;
486 int npaths = (conn->c_trans->t_mp_capable ? RDS_MPATH_WORKERS : 1);
487
488 rdsdebug("freeing conn %p for %pI4 -> "
489 "%pI4\n", conn, &conn->c_laddr,
490 &conn->c_faddr);
491
492 /* Ensure conn will not be scheduled for reconnect */
493 spin_lock_irq(&rds_conn_lock);
494 hlist_del_init_rcu(&conn->c_hash_node);
495 spin_unlock_irq(&rds_conn_lock);
496 synchronize_rcu();
497
498 /* shut the connection down */
499 for (i = 0; i < npaths; i++) {
500 cp = &conn->c_path[i];
501 rds_conn_path_destroy(cp);
502 BUG_ON(!list_empty(&cp->cp_retrans));
503 }
504
505 /*
506 * The congestion maps aren't freed up here. They're
507 * freed by rds_cong_exit() after all the connections
508 * have been freed.
509 */
510 rds_cong_remove_conn(conn);
511
512 kfree(conn->c_path);
513 kmem_cache_free(rds_conn_slab, conn);
514
515 spin_lock_irqsave(&rds_conn_lock, flags);
516 rds_conn_count--;
517 spin_unlock_irqrestore(&rds_conn_lock, flags);
518}
519EXPORT_SYMBOL_GPL(rds_conn_destroy);
520
521static void __rds_inc_msg_cp(struct rds_incoming *inc,
522 struct rds_info_iterator *iter,
523 void *saddr, void *daddr, int flip, bool isv6)
524{
525#if IS_ENABLED(CONFIG_IPV6)
526 if (isv6)
527 rds6_inc_info_copy(inc, iter, saddr, daddr, flip);
528 else
529#endif
530 rds_inc_info_copy(inc, iter, *(__be32 *)saddr,
531 *(__be32 *)daddr, flip);
532}
533
534static void rds_conn_message_info_cmn(struct socket *sock, unsigned int len,
535 struct rds_info_iterator *iter,
536 struct rds_info_lengths *lens,
537 int want_send, bool isv6)
538{
539 struct hlist_head *head;
540 struct list_head *list;
541 struct rds_connection *conn;
542 struct rds_message *rm;
543 unsigned int total = 0;
544 unsigned long flags;
545 size_t i;
546 int j;
547
548 if (isv6)
549 len /= sizeof(struct rds6_info_message);
550 else
551 len /= sizeof(struct rds_info_message);
552
553 rcu_read_lock();
554
555 for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
556 i++, head++) {
557 hlist_for_each_entry_rcu(conn, head, c_hash_node) {
558 struct rds_conn_path *cp;
559 int npaths;
560
561 if (!isv6 && conn->c_isv6)
562 continue;
563
564 npaths = (conn->c_trans->t_mp_capable ?
565 RDS_MPATH_WORKERS : 1);
566
567 for (j = 0; j < npaths; j++) {
568 cp = &conn->c_path[j];
569 if (want_send)
570 list = &cp->cp_send_queue;
571 else
572 list = &cp->cp_retrans;
573
574 spin_lock_irqsave(&cp->cp_lock, flags);
575
576 /* XXX too lazy to maintain counts.. */
577 list_for_each_entry(rm, list, m_conn_item) {
578 total++;
579 if (total <= len)
580 __rds_inc_msg_cp(&rm->m_inc,
581 iter,
582 &conn->c_laddr,
583 &conn->c_faddr,
584 0, isv6);
585 }
586
587 spin_unlock_irqrestore(&cp->cp_lock, flags);
588 }
589 }
590 }
591 rcu_read_unlock();
592
593 lens->nr = total;
594 if (isv6)
595 lens->each = sizeof(struct rds6_info_message);
596 else
597 lens->each = sizeof(struct rds_info_message);
598}
599
600static void rds_conn_message_info(struct socket *sock, unsigned int len,
601 struct rds_info_iterator *iter,
602 struct rds_info_lengths *lens,
603 int want_send)
604{
605 rds_conn_message_info_cmn(sock, len, iter, lens, want_send, false);
606}
607
608#if IS_ENABLED(CONFIG_IPV6)
609static void rds6_conn_message_info(struct socket *sock, unsigned int len,
610 struct rds_info_iterator *iter,
611 struct rds_info_lengths *lens,
612 int want_send)
613{
614 rds_conn_message_info_cmn(sock, len, iter, lens, want_send, true);
615}
616#endif
617
618static void rds_conn_message_info_send(struct socket *sock, unsigned int len,
619 struct rds_info_iterator *iter,
620 struct rds_info_lengths *lens)
621{
622 rds_conn_message_info(sock, len, iter, lens, 1);
623}
624
625#if IS_ENABLED(CONFIG_IPV6)
626static void rds6_conn_message_info_send(struct socket *sock, unsigned int len,
627 struct rds_info_iterator *iter,
628 struct rds_info_lengths *lens)
629{
630 rds6_conn_message_info(sock, len, iter, lens, 1);
631}
632#endif
633
634static void rds_conn_message_info_retrans(struct socket *sock,
635 unsigned int len,
636 struct rds_info_iterator *iter,
637 struct rds_info_lengths *lens)
638{
639 rds_conn_message_info(sock, len, iter, lens, 0);
640}
641
642#if IS_ENABLED(CONFIG_IPV6)
643static void rds6_conn_message_info_retrans(struct socket *sock,
644 unsigned int len,
645 struct rds_info_iterator *iter,
646 struct rds_info_lengths *lens)
647{
648 rds6_conn_message_info(sock, len, iter, lens, 0);
649}
650#endif
651
652void rds_for_each_conn_info(struct socket *sock, unsigned int len,
653 struct rds_info_iterator *iter,
654 struct rds_info_lengths *lens,
655 int (*visitor)(struct rds_connection *, void *),
656 u64 *buffer,
657 size_t item_len)
658{
659 struct hlist_head *head;
660 struct rds_connection *conn;
661 size_t i;
662
663 rcu_read_lock();
664
665 lens->nr = 0;
666 lens->each = item_len;
667
668 for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
669 i++, head++) {
670 hlist_for_each_entry_rcu(conn, head, c_hash_node) {
671
672 /* XXX no c_lock usage.. */
673 if (!visitor(conn, buffer))
674 continue;
675
676 /* We copy as much as we can fit in the buffer,
677 * but we count all items so that the caller
678 * can resize the buffer. */
679 if (len >= item_len) {
680 rds_info_copy(iter, buffer, item_len);
681 len -= item_len;
682 }
683 lens->nr++;
684 }
685 }
686 rcu_read_unlock();
687}
688EXPORT_SYMBOL_GPL(rds_for_each_conn_info);
689
690static void rds_walk_conn_path_info(struct socket *sock, unsigned int len,
691 struct rds_info_iterator *iter,
692 struct rds_info_lengths *lens,
693 int (*visitor)(struct rds_conn_path *, void *),
694 u64 *buffer,
695 size_t item_len)
696{
697 struct hlist_head *head;
698 struct rds_connection *conn;
699 size_t i;
700
701 rcu_read_lock();
702
703 lens->nr = 0;
704 lens->each = item_len;
705
706 for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
707 i++, head++) {
708 hlist_for_each_entry_rcu(conn, head, c_hash_node) {
709 struct rds_conn_path *cp;
710
711 /* XXX We only copy the information from the first
712 * path for now. The problem is that if there are
713 * more than one underlying paths, we cannot report
714 * information of all of them using the existing
715 * API. For example, there is only one next_tx_seq,
716 * which path's next_tx_seq should we report? It is
717 * a bug in the design of MPRDS.
718 */
719 cp = conn->c_path;
720
721 /* XXX no cp_lock usage.. */
722 if (!visitor(cp, buffer))
723 continue;
724
725 /* We copy as much as we can fit in the buffer,
726 * but we count all items so that the caller
727 * can resize the buffer.
728 */
729 if (len >= item_len) {
730 rds_info_copy(iter, buffer, item_len);
731 len -= item_len;
732 }
733 lens->nr++;
734 }
735 }
736 rcu_read_unlock();
737}
738
739static int rds_conn_info_visitor(struct rds_conn_path *cp, void *buffer)
740{
741 struct rds_info_connection *cinfo = buffer;
742 struct rds_connection *conn = cp->cp_conn;
743
744 if (conn->c_isv6)
745 return 0;
746
747 cinfo->next_tx_seq = cp->cp_next_tx_seq;
748 cinfo->next_rx_seq = cp->cp_next_rx_seq;
749 cinfo->laddr = conn->c_laddr.s6_addr32[3];
750 cinfo->faddr = conn->c_faddr.s6_addr32[3];
751 cinfo->tos = conn->c_tos;
752 strncpy(cinfo->transport, conn->c_trans->t_name,
753 sizeof(cinfo->transport));
754 cinfo->flags = 0;
755
756 rds_conn_info_set(cinfo->flags, test_bit(RDS_IN_XMIT, &cp->cp_flags),
757 SENDING);
758 /* XXX Future: return the state rather than these funky bits */
759 rds_conn_info_set(cinfo->flags,
760 atomic_read(&cp->cp_state) == RDS_CONN_CONNECTING,
761 CONNECTING);
762 rds_conn_info_set(cinfo->flags,
763 atomic_read(&cp->cp_state) == RDS_CONN_UP,
764 CONNECTED);
765 return 1;
766}
767
768#if IS_ENABLED(CONFIG_IPV6)
769static int rds6_conn_info_visitor(struct rds_conn_path *cp, void *buffer)
770{
771 struct rds6_info_connection *cinfo6 = buffer;
772 struct rds_connection *conn = cp->cp_conn;
773
774 cinfo6->next_tx_seq = cp->cp_next_tx_seq;
775 cinfo6->next_rx_seq = cp->cp_next_rx_seq;
776 cinfo6->laddr = conn->c_laddr;
777 cinfo6->faddr = conn->c_faddr;
778 strncpy(cinfo6->transport, conn->c_trans->t_name,
779 sizeof(cinfo6->transport));
780 cinfo6->flags = 0;
781
782 rds_conn_info_set(cinfo6->flags, test_bit(RDS_IN_XMIT, &cp->cp_flags),
783 SENDING);
784 /* XXX Future: return the state rather than these funky bits */
785 rds_conn_info_set(cinfo6->flags,
786 atomic_read(&cp->cp_state) == RDS_CONN_CONNECTING,
787 CONNECTING);
788 rds_conn_info_set(cinfo6->flags,
789 atomic_read(&cp->cp_state) == RDS_CONN_UP,
790 CONNECTED);
791 /* Just return 1 as there is no error case. This is a helper function
792 * for rds_walk_conn_path_info() and it wants a return value.
793 */
794 return 1;
795}
796#endif
797
798static void rds_conn_info(struct socket *sock, unsigned int len,
799 struct rds_info_iterator *iter,
800 struct rds_info_lengths *lens)
801{
802 u64 buffer[(sizeof(struct rds_info_connection) + 7) / 8];
803
804 rds_walk_conn_path_info(sock, len, iter, lens,
805 rds_conn_info_visitor,
806 buffer,
807 sizeof(struct rds_info_connection));
808}
809
810#if IS_ENABLED(CONFIG_IPV6)
811static void rds6_conn_info(struct socket *sock, unsigned int len,
812 struct rds_info_iterator *iter,
813 struct rds_info_lengths *lens)
814{
815 u64 buffer[(sizeof(struct rds6_info_connection) + 7) / 8];
816
817 rds_walk_conn_path_info(sock, len, iter, lens,
818 rds6_conn_info_visitor,
819 buffer,
820 sizeof(struct rds6_info_connection));
821}
822#endif
823
824int rds_conn_init(void)
825{
826 int ret;
827
828 ret = rds_loop_net_init(); /* register pernet callback */
829 if (ret)
830 return ret;
831
832 rds_conn_slab = kmem_cache_create("rds_connection",
833 sizeof(struct rds_connection),
834 0, 0, NULL);
835 if (!rds_conn_slab) {
836 rds_loop_net_exit();
837 return -ENOMEM;
838 }
839
840 rds_info_register_func(RDS_INFO_CONNECTIONS, rds_conn_info);
841 rds_info_register_func(RDS_INFO_SEND_MESSAGES,
842 rds_conn_message_info_send);
843 rds_info_register_func(RDS_INFO_RETRANS_MESSAGES,
844 rds_conn_message_info_retrans);
845#if IS_ENABLED(CONFIG_IPV6)
846 rds_info_register_func(RDS6_INFO_CONNECTIONS, rds6_conn_info);
847 rds_info_register_func(RDS6_INFO_SEND_MESSAGES,
848 rds6_conn_message_info_send);
849 rds_info_register_func(RDS6_INFO_RETRANS_MESSAGES,
850 rds6_conn_message_info_retrans);
851#endif
852 return 0;
853}
854
855void rds_conn_exit(void)
856{
857 rds_loop_net_exit(); /* unregister pernet callback */
858 rds_loop_exit();
859
860 WARN_ON(!hlist_empty(rds_conn_hash));
861
862 kmem_cache_destroy(rds_conn_slab);
863
864 rds_info_deregister_func(RDS_INFO_CONNECTIONS, rds_conn_info);
865 rds_info_deregister_func(RDS_INFO_SEND_MESSAGES,
866 rds_conn_message_info_send);
867 rds_info_deregister_func(RDS_INFO_RETRANS_MESSAGES,
868 rds_conn_message_info_retrans);
869#if IS_ENABLED(CONFIG_IPV6)
870 rds_info_deregister_func(RDS6_INFO_CONNECTIONS, rds6_conn_info);
871 rds_info_deregister_func(RDS6_INFO_SEND_MESSAGES,
872 rds6_conn_message_info_send);
873 rds_info_deregister_func(RDS6_INFO_RETRANS_MESSAGES,
874 rds6_conn_message_info_retrans);
875#endif
876}
877
878/*
879 * Force a disconnect
880 */
881void rds_conn_path_drop(struct rds_conn_path *cp, bool destroy)
882{
883 atomic_set(&cp->cp_state, RDS_CONN_ERROR);
884
885 rcu_read_lock();
886 if (!destroy && rds_destroy_pending(cp->cp_conn)) {
887 rcu_read_unlock();
888 return;
889 }
890 queue_work(rds_wq, &cp->cp_down_w);
891 rcu_read_unlock();
892}
893EXPORT_SYMBOL_GPL(rds_conn_path_drop);
894
895void rds_conn_drop(struct rds_connection *conn)
896{
897 WARN_ON(conn->c_trans->t_mp_capable);
898 rds_conn_path_drop(&conn->c_path[0], false);
899}
900EXPORT_SYMBOL_GPL(rds_conn_drop);
901
902/*
903 * If the connection is down, trigger a connect. We may have scheduled a
904 * delayed reconnect however - in this case we should not interfere.
905 */
906void rds_conn_path_connect_if_down(struct rds_conn_path *cp)
907{
908 rcu_read_lock();
909 if (rds_destroy_pending(cp->cp_conn)) {
910 rcu_read_unlock();
911 return;
912 }
913 if (rds_conn_path_state(cp) == RDS_CONN_DOWN &&
914 !test_and_set_bit(RDS_RECONNECT_PENDING, &cp->cp_flags))
915 queue_delayed_work(rds_wq, &cp->cp_conn_w, 0);
916 rcu_read_unlock();
917}
918EXPORT_SYMBOL_GPL(rds_conn_path_connect_if_down);
919
920/* Check connectivity of all paths
921 */
922void rds_check_all_paths(struct rds_connection *conn)
923{
924 int i = 0;
925
926 do {
927 rds_conn_path_connect_if_down(&conn->c_path[i]);
928 } while (++i < conn->c_npaths);
929}
930
931void rds_conn_connect_if_down(struct rds_connection *conn)
932{
933 WARN_ON(conn->c_trans->t_mp_capable);
934 rds_conn_path_connect_if_down(&conn->c_path[0]);
935}
936EXPORT_SYMBOL_GPL(rds_conn_connect_if_down);
937
938void
939__rds_conn_path_error(struct rds_conn_path *cp, const char *fmt, ...)
940{
941 va_list ap;
942
943 va_start(ap, fmt);
944 vprintk(fmt, ap);
945 va_end(ap);
946
947 rds_conn_path_drop(cp, false);
948}