GNU Linux-libre 4.19.211-gnu1
[releases.git] / net / rds / connection.c
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.. */
49 static DEFINE_SPINLOCK(rds_conn_lock);
50 static unsigned long rds_conn_count;
51 static struct hlist_head rds_conn_hash[RDS_CONNECTION_HASH_ENTRIES];
52 static struct kmem_cache *rds_conn_slab;
53
54 static 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 */
82 static 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                                               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                     net == rds_conn_net(conn) &&
96                     conn->c_dev_if == dev_if) {
97                         ret = conn;
98                         break;
99                 }
100         }
101         rdsdebug("returning conn %p for %pI6c -> %pI6c\n", ret,
102                  laddr, faddr);
103         return ret;
104 }
105
106 /*
107  * This is called by transports as they're bringing down a connection.
108  * It clears partial message state so that the transport can start sending
109  * and receiving over this connection again in the future.  It is up to
110  * the transport to have serialized this call with its send and recv.
111  */
112 static void rds_conn_path_reset(struct rds_conn_path *cp)
113 {
114         struct rds_connection *conn = cp->cp_conn;
115
116         rdsdebug("connection %pI6c to %pI6c reset\n",
117                  &conn->c_laddr, &conn->c_faddr);
118
119         rds_stats_inc(s_conn_reset);
120         rds_send_path_reset(cp);
121         cp->cp_flags = 0;
122
123         /* Do not clear next_rx_seq here, else we cannot distinguish
124          * retransmitted packets from new packets, and will hand all
125          * of them to the application. That is not consistent with the
126          * reliability guarantees of RDS. */
127 }
128
129 static void __rds_conn_path_init(struct rds_connection *conn,
130                                  struct rds_conn_path *cp, bool is_outgoing)
131 {
132         spin_lock_init(&cp->cp_lock);
133         cp->cp_next_tx_seq = 1;
134         init_waitqueue_head(&cp->cp_waitq);
135         INIT_LIST_HEAD(&cp->cp_send_queue);
136         INIT_LIST_HEAD(&cp->cp_retrans);
137
138         cp->cp_conn = conn;
139         atomic_set(&cp->cp_state, RDS_CONN_DOWN);
140         cp->cp_send_gen = 0;
141         cp->cp_reconnect_jiffies = 0;
142         INIT_DELAYED_WORK(&cp->cp_send_w, rds_send_worker);
143         INIT_DELAYED_WORK(&cp->cp_recv_w, rds_recv_worker);
144         INIT_DELAYED_WORK(&cp->cp_conn_w, rds_connect_worker);
145         INIT_WORK(&cp->cp_down_w, rds_shutdown_worker);
146         mutex_init(&cp->cp_cm_lock);
147         cp->cp_flags = 0;
148 }
149
150 /*
151  * There is only every one 'conn' for a given pair of addresses in the
152  * system at a time.  They contain messages to be retransmitted and so
153  * span the lifetime of the actual underlying transport connections.
154  *
155  * For now they are not garbage collected once they're created.  They
156  * are torn down as the module is removed, if ever.
157  */
158 static struct rds_connection *__rds_conn_create(struct net *net,
159                                                 const struct in6_addr *laddr,
160                                                 const struct in6_addr *faddr,
161                                                 struct rds_transport *trans,
162                                                 gfp_t gfp,
163                                                 int is_outgoing,
164                                                 int dev_if)
165 {
166         struct rds_connection *conn, *parent = NULL;
167         struct hlist_head *head = rds_conn_bucket(laddr, faddr);
168         struct rds_transport *loop_trans;
169         unsigned long flags;
170         int ret, i;
171         int npaths = (trans->t_mp_capable ? RDS_MPATH_WORKERS : 1);
172
173         rcu_read_lock();
174         conn = rds_conn_lookup(net, head, laddr, faddr, trans, dev_if);
175         if (conn &&
176             conn->c_loopback &&
177             conn->c_trans != &rds_loop_transport &&
178             ipv6_addr_equal(laddr, faddr) &&
179             !is_outgoing) {
180                 /* This is a looped back IB connection, and we're
181                  * called by the code handling the incoming connect.
182                  * We need a second connection object into which we
183                  * can stick the other QP. */
184                 parent = conn;
185                 conn = parent->c_passive;
186         }
187         rcu_read_unlock();
188         if (conn)
189                 goto out;
190
191         conn = kmem_cache_zalloc(rds_conn_slab, gfp);
192         if (!conn) {
193                 conn = ERR_PTR(-ENOMEM);
194                 goto out;
195         }
196         conn->c_path = kcalloc(npaths, sizeof(struct rds_conn_path), gfp);
197         if (!conn->c_path) {
198                 kmem_cache_free(rds_conn_slab, conn);
199                 conn = ERR_PTR(-ENOMEM);
200                 goto out;
201         }
202
203         INIT_HLIST_NODE(&conn->c_hash_node);
204         conn->c_laddr = *laddr;
205         conn->c_isv6 = !ipv6_addr_v4mapped(laddr);
206         conn->c_faddr = *faddr;
207         conn->c_dev_if = dev_if;
208
209 #if IS_ENABLED(CONFIG_IPV6)
210         /* If the local address is link local, set c_bound_if to be the
211          * index used for this connection.  Otherwise, set it to 0 as
212          * the socket is not bound to an interface.  c_bound_if is used
213          * to look up a socket when a packet is received
214          */
215         if (ipv6_addr_type(laddr) & IPV6_ADDR_LINKLOCAL)
216                 conn->c_bound_if = dev_if;
217         else
218 #endif
219                 conn->c_bound_if = 0;
220
221         rds_conn_net_set(conn, net);
222
223         ret = rds_cong_get_maps(conn);
224         if (ret) {
225                 kfree(conn->c_path);
226                 kmem_cache_free(rds_conn_slab, conn);
227                 conn = ERR_PTR(ret);
228                 goto out;
229         }
230
231         /*
232          * This is where a connection becomes loopback.  If *any* RDS sockets
233          * can bind to the destination address then we'd rather the messages
234          * flow through loopback rather than either transport.
235          */
236         loop_trans = rds_trans_get_preferred(net, faddr, conn->c_dev_if);
237         if (loop_trans) {
238                 rds_trans_put(loop_trans);
239                 conn->c_loopback = 1;
240                 if (trans->t_prefer_loopback) {
241                         if (likely(is_outgoing)) {
242                                 /* "outgoing" connection to local address.
243                                  * Protocol says it wants the connection
244                                  * handled by the loopback transport.
245                                  * This is what TCP does.
246                                  */
247                                 trans = &rds_loop_transport;
248                         } else {
249                                 /* No transport currently in use
250                                  * should end up here, but if it
251                                  * does, reset/destroy the connection.
252                                  */
253                                 kmem_cache_free(rds_conn_slab, conn);
254                                 conn = ERR_PTR(-EOPNOTSUPP);
255                                 goto out;
256                         }
257                 }
258         }
259
260         conn->c_trans = trans;
261
262         init_waitqueue_head(&conn->c_hs_waitq);
263         for (i = 0; i < npaths; i++) {
264                 __rds_conn_path_init(conn, &conn->c_path[i],
265                                      is_outgoing);
266                 conn->c_path[i].cp_index = i;
267         }
268         rcu_read_lock();
269         if (rds_destroy_pending(conn))
270                 ret = -ENETDOWN;
271         else
272                 ret = trans->conn_alloc(conn, GFP_ATOMIC);
273         if (ret) {
274                 rcu_read_unlock();
275                 kfree(conn->c_path);
276                 kmem_cache_free(rds_conn_slab, conn);
277                 conn = ERR_PTR(ret);
278                 goto out;
279         }
280
281         rdsdebug("allocated conn %p for %pI6c -> %pI6c over %s %s\n",
282                  conn, laddr, faddr,
283                  strnlen(trans->t_name, sizeof(trans->t_name)) ?
284                  trans->t_name : "[unknown]", is_outgoing ? "(outgoing)" : "");
285
286         /*
287          * Since we ran without holding the conn lock, someone could
288          * have created the same conn (either normal or passive) in the
289          * interim. We check while holding the lock. If we won, we complete
290          * init and return our conn. If we lost, we rollback and return the
291          * other one.
292          */
293         spin_lock_irqsave(&rds_conn_lock, flags);
294         if (parent) {
295                 /* Creating passive conn */
296                 if (parent->c_passive) {
297                         trans->conn_free(conn->c_path[0].cp_transport_data);
298                         kfree(conn->c_path);
299                         kmem_cache_free(rds_conn_slab, conn);
300                         conn = parent->c_passive;
301                 } else {
302                         parent->c_passive = conn;
303                         rds_cong_add_conn(conn);
304                         rds_conn_count++;
305                 }
306         } else {
307                 /* Creating normal conn */
308                 struct rds_connection *found;
309
310                 found = rds_conn_lookup(net, head, laddr, faddr, trans,
311                                         dev_if);
312                 if (found) {
313                         struct rds_conn_path *cp;
314                         int i;
315
316                         for (i = 0; i < npaths; i++) {
317                                 cp = &conn->c_path[i];
318                                 /* The ->conn_alloc invocation may have
319                                  * allocated resource for all paths, so all
320                                  * of them may have to be freed here.
321                                  */
322                                 if (cp->cp_transport_data)
323                                         trans->conn_free(cp->cp_transport_data);
324                         }
325                         kfree(conn->c_path);
326                         kmem_cache_free(rds_conn_slab, conn);
327                         conn = found;
328                 } else {
329                         conn->c_my_gen_num = rds_gen_num;
330                         conn->c_peer_gen_num = 0;
331                         hlist_add_head_rcu(&conn->c_hash_node, head);
332                         rds_cong_add_conn(conn);
333                         rds_conn_count++;
334                 }
335         }
336         spin_unlock_irqrestore(&rds_conn_lock, flags);
337         rcu_read_unlock();
338
339 out:
340         return conn;
341 }
342
343 struct rds_connection *rds_conn_create(struct net *net,
344                                        const struct in6_addr *laddr,
345                                        const struct in6_addr *faddr,
346                                        struct rds_transport *trans, gfp_t gfp,
347                                        int dev_if)
348 {
349         return __rds_conn_create(net, laddr, faddr, trans, gfp, 0, dev_if);
350 }
351 EXPORT_SYMBOL_GPL(rds_conn_create);
352
353 struct rds_connection *rds_conn_create_outgoing(struct net *net,
354                                                 const struct in6_addr *laddr,
355                                                 const struct in6_addr *faddr,
356                                                 struct rds_transport *trans,
357                                                 gfp_t gfp, int dev_if)
358 {
359         return __rds_conn_create(net, laddr, faddr, trans, gfp, 1, dev_if);
360 }
361 EXPORT_SYMBOL_GPL(rds_conn_create_outgoing);
362
363 void rds_conn_shutdown(struct rds_conn_path *cp)
364 {
365         struct rds_connection *conn = cp->cp_conn;
366
367         /* shut it down unless it's down already */
368         if (!rds_conn_path_transition(cp, RDS_CONN_DOWN, RDS_CONN_DOWN)) {
369                 /*
370                  * Quiesce the connection mgmt handlers before we start tearing
371                  * things down. We don't hold the mutex for the entire
372                  * duration of the shutdown operation, else we may be
373                  * deadlocking with the CM handler. Instead, the CM event
374                  * handler is supposed to check for state DISCONNECTING
375                  */
376                 mutex_lock(&cp->cp_cm_lock);
377                 if (!rds_conn_path_transition(cp, RDS_CONN_UP,
378                                               RDS_CONN_DISCONNECTING) &&
379                     !rds_conn_path_transition(cp, RDS_CONN_ERROR,
380                                               RDS_CONN_DISCONNECTING)) {
381                         rds_conn_path_error(cp,
382                                             "shutdown called in state %d\n",
383                                             atomic_read(&cp->cp_state));
384                         mutex_unlock(&cp->cp_cm_lock);
385                         return;
386                 }
387                 mutex_unlock(&cp->cp_cm_lock);
388
389                 wait_event(cp->cp_waitq,
390                            !test_bit(RDS_IN_XMIT, &cp->cp_flags));
391                 wait_event(cp->cp_waitq,
392                            !test_bit(RDS_RECV_REFILL, &cp->cp_flags));
393
394                 conn->c_trans->conn_path_shutdown(cp);
395                 rds_conn_path_reset(cp);
396
397                 if (!rds_conn_path_transition(cp, RDS_CONN_DISCONNECTING,
398                                               RDS_CONN_DOWN) &&
399                     !rds_conn_path_transition(cp, RDS_CONN_ERROR,
400                                               RDS_CONN_DOWN)) {
401                         /* This can happen - eg when we're in the middle of tearing
402                          * down the connection, and someone unloads the rds module.
403                          * Quite reproducible with loopback connections.
404                          * Mostly harmless.
405                          *
406                          * Note that this also happens with rds-tcp because
407                          * we could have triggered rds_conn_path_drop in irq
408                          * mode from rds_tcp_state change on the receipt of
409                          * a FIN, thus we need to recheck for RDS_CONN_ERROR
410                          * here.
411                          */
412                         rds_conn_path_error(cp, "%s: failed to transition "
413                                             "to state DOWN, current state "
414                                             "is %d\n", __func__,
415                                             atomic_read(&cp->cp_state));
416                         return;
417                 }
418         }
419
420         /* Then reconnect if it's still live.
421          * The passive side of an IB loopback connection is never added
422          * to the conn hash, so we never trigger a reconnect on this
423          * conn - the reconnect is always triggered by the active peer. */
424         cancel_delayed_work_sync(&cp->cp_conn_w);
425         rcu_read_lock();
426         if (!hlist_unhashed(&conn->c_hash_node)) {
427                 rcu_read_unlock();
428                 rds_queue_reconnect(cp);
429         } else {
430                 rcu_read_unlock();
431         }
432 }
433
434 /* destroy a single rds_conn_path. rds_conn_destroy() iterates over
435  * all paths using rds_conn_path_destroy()
436  */
437 static void rds_conn_path_destroy(struct rds_conn_path *cp)
438 {
439         struct rds_message *rm, *rtmp;
440
441         if (!cp->cp_transport_data)
442                 return;
443
444         /* make sure lingering queued work won't try to ref the conn */
445         cancel_delayed_work_sync(&cp->cp_send_w);
446         cancel_delayed_work_sync(&cp->cp_recv_w);
447
448         rds_conn_path_drop(cp, true);
449         flush_work(&cp->cp_down_w);
450
451         /* tear down queued messages */
452         list_for_each_entry_safe(rm, rtmp,
453                                  &cp->cp_send_queue,
454                                  m_conn_item) {
455                 list_del_init(&rm->m_conn_item);
456                 BUG_ON(!list_empty(&rm->m_sock_item));
457                 rds_message_put(rm);
458         }
459         if (cp->cp_xmit_rm)
460                 rds_message_put(cp->cp_xmit_rm);
461
462         WARN_ON(delayed_work_pending(&cp->cp_send_w));
463         WARN_ON(delayed_work_pending(&cp->cp_recv_w));
464         WARN_ON(delayed_work_pending(&cp->cp_conn_w));
465         WARN_ON(work_pending(&cp->cp_down_w));
466
467         cp->cp_conn->c_trans->conn_free(cp->cp_transport_data);
468 }
469
470 /*
471  * Stop and free a connection.
472  *
473  * This can only be used in very limited circumstances.  It assumes that once
474  * the conn has been shutdown that no one else is referencing the connection.
475  * We can only ensure this in the rmmod path in the current code.
476  */
477 void rds_conn_destroy(struct rds_connection *conn)
478 {
479         unsigned long flags;
480         int i;
481         struct rds_conn_path *cp;
482         int npaths = (conn->c_trans->t_mp_capable ? RDS_MPATH_WORKERS : 1);
483
484         rdsdebug("freeing conn %p for %pI4 -> "
485                  "%pI4\n", conn, &conn->c_laddr,
486                  &conn->c_faddr);
487
488         /* Ensure conn will not be scheduled for reconnect */
489         spin_lock_irq(&rds_conn_lock);
490         hlist_del_init_rcu(&conn->c_hash_node);
491         spin_unlock_irq(&rds_conn_lock);
492         synchronize_rcu();
493
494         /* shut the connection down */
495         for (i = 0; i < npaths; i++) {
496                 cp = &conn->c_path[i];
497                 rds_conn_path_destroy(cp);
498                 BUG_ON(!list_empty(&cp->cp_retrans));
499         }
500
501         /*
502          * The congestion maps aren't freed up here.  They're
503          * freed by rds_cong_exit() after all the connections
504          * have been freed.
505          */
506         rds_cong_remove_conn(conn);
507
508         kfree(conn->c_path);
509         kmem_cache_free(rds_conn_slab, conn);
510
511         spin_lock_irqsave(&rds_conn_lock, flags);
512         rds_conn_count--;
513         spin_unlock_irqrestore(&rds_conn_lock, flags);
514 }
515 EXPORT_SYMBOL_GPL(rds_conn_destroy);
516
517 static void __rds_inc_msg_cp(struct rds_incoming *inc,
518                              struct rds_info_iterator *iter,
519                              void *saddr, void *daddr, int flip, bool isv6)
520 {
521 #if IS_ENABLED(CONFIG_IPV6)
522         if (isv6)
523                 rds6_inc_info_copy(inc, iter, saddr, daddr, flip);
524         else
525 #endif
526                 rds_inc_info_copy(inc, iter, *(__be32 *)saddr,
527                                   *(__be32 *)daddr, flip);
528 }
529
530 static void rds_conn_message_info_cmn(struct socket *sock, unsigned int len,
531                                       struct rds_info_iterator *iter,
532                                       struct rds_info_lengths *lens,
533                                       int want_send, bool isv6)
534 {
535         struct hlist_head *head;
536         struct list_head *list;
537         struct rds_connection *conn;
538         struct rds_message *rm;
539         unsigned int total = 0;
540         unsigned long flags;
541         size_t i;
542         int j;
543
544         if (isv6)
545                 len /= sizeof(struct rds6_info_message);
546         else
547                 len /= sizeof(struct rds_info_message);
548
549         rcu_read_lock();
550
551         for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
552              i++, head++) {
553                 hlist_for_each_entry_rcu(conn, head, c_hash_node) {
554                         struct rds_conn_path *cp;
555                         int npaths;
556
557                         if (!isv6 && conn->c_isv6)
558                                 continue;
559
560                         npaths = (conn->c_trans->t_mp_capable ?
561                                  RDS_MPATH_WORKERS : 1);
562
563                         for (j = 0; j < npaths; j++) {
564                                 cp = &conn->c_path[j];
565                                 if (want_send)
566                                         list = &cp->cp_send_queue;
567                                 else
568                                         list = &cp->cp_retrans;
569
570                                 spin_lock_irqsave(&cp->cp_lock, flags);
571
572                                 /* XXX too lazy to maintain counts.. */
573                                 list_for_each_entry(rm, list, m_conn_item) {
574                                         total++;
575                                         if (total <= len)
576                                                 __rds_inc_msg_cp(&rm->m_inc,
577                                                                  iter,
578                                                                  &conn->c_laddr,
579                                                                  &conn->c_faddr,
580                                                                  0, isv6);
581                                 }
582
583                                 spin_unlock_irqrestore(&cp->cp_lock, flags);
584                         }
585                 }
586         }
587         rcu_read_unlock();
588
589         lens->nr = total;
590         if (isv6)
591                 lens->each = sizeof(struct rds6_info_message);
592         else
593                 lens->each = sizeof(struct rds_info_message);
594 }
595
596 static void rds_conn_message_info(struct socket *sock, unsigned int len,
597                                   struct rds_info_iterator *iter,
598                                   struct rds_info_lengths *lens,
599                                   int want_send)
600 {
601         rds_conn_message_info_cmn(sock, len, iter, lens, want_send, false);
602 }
603
604 #if IS_ENABLED(CONFIG_IPV6)
605 static void rds6_conn_message_info(struct socket *sock, unsigned int len,
606                                    struct rds_info_iterator *iter,
607                                    struct rds_info_lengths *lens,
608                                    int want_send)
609 {
610         rds_conn_message_info_cmn(sock, len, iter, lens, want_send, true);
611 }
612 #endif
613
614 static void rds_conn_message_info_send(struct socket *sock, unsigned int len,
615                                        struct rds_info_iterator *iter,
616                                        struct rds_info_lengths *lens)
617 {
618         rds_conn_message_info(sock, len, iter, lens, 1);
619 }
620
621 #if IS_ENABLED(CONFIG_IPV6)
622 static void rds6_conn_message_info_send(struct socket *sock, unsigned int len,
623                                         struct rds_info_iterator *iter,
624                                         struct rds_info_lengths *lens)
625 {
626         rds6_conn_message_info(sock, len, iter, lens, 1);
627 }
628 #endif
629
630 static void rds_conn_message_info_retrans(struct socket *sock,
631                                           unsigned int len,
632                                           struct rds_info_iterator *iter,
633                                           struct rds_info_lengths *lens)
634 {
635         rds_conn_message_info(sock, len, iter, lens, 0);
636 }
637
638 #if IS_ENABLED(CONFIG_IPV6)
639 static void rds6_conn_message_info_retrans(struct socket *sock,
640                                            unsigned int len,
641                                            struct rds_info_iterator *iter,
642                                            struct rds_info_lengths *lens)
643 {
644         rds6_conn_message_info(sock, len, iter, lens, 0);
645 }
646 #endif
647
648 void rds_for_each_conn_info(struct socket *sock, unsigned int len,
649                           struct rds_info_iterator *iter,
650                           struct rds_info_lengths *lens,
651                           int (*visitor)(struct rds_connection *, void *),
652                           u64 *buffer,
653                           size_t item_len)
654 {
655         struct hlist_head *head;
656         struct rds_connection *conn;
657         size_t i;
658
659         rcu_read_lock();
660
661         lens->nr = 0;
662         lens->each = item_len;
663
664         for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
665              i++, head++) {
666                 hlist_for_each_entry_rcu(conn, head, c_hash_node) {
667
668                         /* XXX no c_lock usage.. */
669                         if (!visitor(conn, buffer))
670                                 continue;
671
672                         /* We copy as much as we can fit in the buffer,
673                          * but we count all items so that the caller
674                          * can resize the buffer. */
675                         if (len >= item_len) {
676                                 rds_info_copy(iter, buffer, item_len);
677                                 len -= item_len;
678                         }
679                         lens->nr++;
680                 }
681         }
682         rcu_read_unlock();
683 }
684 EXPORT_SYMBOL_GPL(rds_for_each_conn_info);
685
686 static void rds_walk_conn_path_info(struct socket *sock, unsigned int len,
687                                     struct rds_info_iterator *iter,
688                                     struct rds_info_lengths *lens,
689                                     int (*visitor)(struct rds_conn_path *, void *),
690                                     u64 *buffer,
691                                     size_t item_len)
692 {
693         struct hlist_head *head;
694         struct rds_connection *conn;
695         size_t i;
696
697         rcu_read_lock();
698
699         lens->nr = 0;
700         lens->each = item_len;
701
702         for (i = 0, head = rds_conn_hash; i < ARRAY_SIZE(rds_conn_hash);
703              i++, head++) {
704                 hlist_for_each_entry_rcu(conn, head, c_hash_node) {
705                         struct rds_conn_path *cp;
706
707                         /* XXX We only copy the information from the first
708                          * path for now.  The problem is that if there are
709                          * more than one underlying paths, we cannot report
710                          * information of all of them using the existing
711                          * API.  For example, there is only one next_tx_seq,
712                          * which path's next_tx_seq should we report?  It is
713                          * a bug in the design of MPRDS.
714                          */
715                         cp = conn->c_path;
716
717                         /* XXX no cp_lock usage.. */
718                         if (!visitor(cp, buffer))
719                                 continue;
720
721                         /* We copy as much as we can fit in the buffer,
722                          * but we count all items so that the caller
723                          * can resize the buffer.
724                          */
725                         if (len >= item_len) {
726                                 rds_info_copy(iter, buffer, item_len);
727                                 len -= item_len;
728                         }
729                         lens->nr++;
730                 }
731         }
732         rcu_read_unlock();
733 }
734
735 static int rds_conn_info_visitor(struct rds_conn_path *cp, void *buffer)
736 {
737         struct rds_info_connection *cinfo = buffer;
738         struct rds_connection *conn = cp->cp_conn;
739
740         if (conn->c_isv6)
741                 return 0;
742
743         cinfo->next_tx_seq = cp->cp_next_tx_seq;
744         cinfo->next_rx_seq = cp->cp_next_rx_seq;
745         cinfo->laddr = conn->c_laddr.s6_addr32[3];
746         cinfo->faddr = conn->c_faddr.s6_addr32[3];
747         strncpy(cinfo->transport, conn->c_trans->t_name,
748                 sizeof(cinfo->transport));
749         cinfo->flags = 0;
750
751         rds_conn_info_set(cinfo->flags, test_bit(RDS_IN_XMIT, &cp->cp_flags),
752                           SENDING);
753         /* XXX Future: return the state rather than these funky bits */
754         rds_conn_info_set(cinfo->flags,
755                           atomic_read(&cp->cp_state) == RDS_CONN_CONNECTING,
756                           CONNECTING);
757         rds_conn_info_set(cinfo->flags,
758                           atomic_read(&cp->cp_state) == RDS_CONN_UP,
759                           CONNECTED);
760         return 1;
761 }
762
763 #if IS_ENABLED(CONFIG_IPV6)
764 static int rds6_conn_info_visitor(struct rds_conn_path *cp, void *buffer)
765 {
766         struct rds6_info_connection *cinfo6 = buffer;
767         struct rds_connection *conn = cp->cp_conn;
768
769         cinfo6->next_tx_seq = cp->cp_next_tx_seq;
770         cinfo6->next_rx_seq = cp->cp_next_rx_seq;
771         cinfo6->laddr = conn->c_laddr;
772         cinfo6->faddr = conn->c_faddr;
773         strncpy(cinfo6->transport, conn->c_trans->t_name,
774                 sizeof(cinfo6->transport));
775         cinfo6->flags = 0;
776
777         rds_conn_info_set(cinfo6->flags, test_bit(RDS_IN_XMIT, &cp->cp_flags),
778                           SENDING);
779         /* XXX Future: return the state rather than these funky bits */
780         rds_conn_info_set(cinfo6->flags,
781                           atomic_read(&cp->cp_state) == RDS_CONN_CONNECTING,
782                           CONNECTING);
783         rds_conn_info_set(cinfo6->flags,
784                           atomic_read(&cp->cp_state) == RDS_CONN_UP,
785                           CONNECTED);
786         /* Just return 1 as there is no error case. This is a helper function
787          * for rds_walk_conn_path_info() and it wants a return value.
788          */
789         return 1;
790 }
791 #endif
792
793 static void rds_conn_info(struct socket *sock, unsigned int len,
794                           struct rds_info_iterator *iter,
795                           struct rds_info_lengths *lens)
796 {
797         u64 buffer[(sizeof(struct rds_info_connection) + 7) / 8];
798
799         rds_walk_conn_path_info(sock, len, iter, lens,
800                                 rds_conn_info_visitor,
801                                 buffer,
802                                 sizeof(struct rds_info_connection));
803 }
804
805 #if IS_ENABLED(CONFIG_IPV6)
806 static void rds6_conn_info(struct socket *sock, unsigned int len,
807                            struct rds_info_iterator *iter,
808                            struct rds_info_lengths *lens)
809 {
810         u64 buffer[(sizeof(struct rds6_info_connection) + 7) / 8];
811
812         rds_walk_conn_path_info(sock, len, iter, lens,
813                                 rds6_conn_info_visitor,
814                                 buffer,
815                                 sizeof(struct rds6_info_connection));
816 }
817 #endif
818
819 int rds_conn_init(void)
820 {
821         int ret;
822
823         ret = rds_loop_net_init(); /* register pernet callback */
824         if (ret)
825                 return ret;
826
827         rds_conn_slab = kmem_cache_create("rds_connection",
828                                           sizeof(struct rds_connection),
829                                           0, 0, NULL);
830         if (!rds_conn_slab) {
831                 rds_loop_net_exit();
832                 return -ENOMEM;
833         }
834
835         rds_info_register_func(RDS_INFO_CONNECTIONS, rds_conn_info);
836         rds_info_register_func(RDS_INFO_SEND_MESSAGES,
837                                rds_conn_message_info_send);
838         rds_info_register_func(RDS_INFO_RETRANS_MESSAGES,
839                                rds_conn_message_info_retrans);
840 #if IS_ENABLED(CONFIG_IPV6)
841         rds_info_register_func(RDS6_INFO_CONNECTIONS, rds6_conn_info);
842         rds_info_register_func(RDS6_INFO_SEND_MESSAGES,
843                                rds6_conn_message_info_send);
844         rds_info_register_func(RDS6_INFO_RETRANS_MESSAGES,
845                                rds6_conn_message_info_retrans);
846 #endif
847         return 0;
848 }
849
850 void rds_conn_exit(void)
851 {
852         rds_loop_net_exit(); /* unregister pernet callback */
853         rds_loop_exit();
854
855         WARN_ON(!hlist_empty(rds_conn_hash));
856
857         kmem_cache_destroy(rds_conn_slab);
858
859         rds_info_deregister_func(RDS_INFO_CONNECTIONS, rds_conn_info);
860         rds_info_deregister_func(RDS_INFO_SEND_MESSAGES,
861                                  rds_conn_message_info_send);
862         rds_info_deregister_func(RDS_INFO_RETRANS_MESSAGES,
863                                  rds_conn_message_info_retrans);
864 #if IS_ENABLED(CONFIG_IPV6)
865         rds_info_deregister_func(RDS6_INFO_CONNECTIONS, rds6_conn_info);
866         rds_info_deregister_func(RDS6_INFO_SEND_MESSAGES,
867                                  rds6_conn_message_info_send);
868         rds_info_deregister_func(RDS6_INFO_RETRANS_MESSAGES,
869                                  rds6_conn_message_info_retrans);
870 #endif
871 }
872
873 /*
874  * Force a disconnect
875  */
876 void rds_conn_path_drop(struct rds_conn_path *cp, bool destroy)
877 {
878         atomic_set(&cp->cp_state, RDS_CONN_ERROR);
879
880         rcu_read_lock();
881         if (!destroy && rds_destroy_pending(cp->cp_conn)) {
882                 rcu_read_unlock();
883                 return;
884         }
885         queue_work(rds_wq, &cp->cp_down_w);
886         rcu_read_unlock();
887 }
888 EXPORT_SYMBOL_GPL(rds_conn_path_drop);
889
890 void rds_conn_drop(struct rds_connection *conn)
891 {
892         WARN_ON(conn->c_trans->t_mp_capable);
893         rds_conn_path_drop(&conn->c_path[0], false);
894 }
895 EXPORT_SYMBOL_GPL(rds_conn_drop);
896
897 /*
898  * If the connection is down, trigger a connect. We may have scheduled a
899  * delayed reconnect however - in this case we should not interfere.
900  */
901 void rds_conn_path_connect_if_down(struct rds_conn_path *cp)
902 {
903         rcu_read_lock();
904         if (rds_destroy_pending(cp->cp_conn)) {
905                 rcu_read_unlock();
906                 return;
907         }
908         if (rds_conn_path_state(cp) == RDS_CONN_DOWN &&
909             !test_and_set_bit(RDS_RECONNECT_PENDING, &cp->cp_flags))
910                 queue_delayed_work(rds_wq, &cp->cp_conn_w, 0);
911         rcu_read_unlock();
912 }
913 EXPORT_SYMBOL_GPL(rds_conn_path_connect_if_down);
914
915 void rds_conn_connect_if_down(struct rds_connection *conn)
916 {
917         WARN_ON(conn->c_trans->t_mp_capable);
918         rds_conn_path_connect_if_down(&conn->c_path[0]);
919 }
920 EXPORT_SYMBOL_GPL(rds_conn_connect_if_down);
921
922 void
923 __rds_conn_path_error(struct rds_conn_path *cp, const char *fmt, ...)
924 {
925         va_list ap;
926
927         va_start(ap, fmt);
928         vprintk(fmt, ap);
929         va_end(ap);
930
931         rds_conn_path_drop(cp, false);
932 }