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(rds_connection, 0);
833	if (!rds_conn_slab) {
834		rds_loop_net_exit();
835		return -ENOMEM;
836	}
837
838	rds_info_register_func(RDS_INFO_CONNECTIONS, rds_conn_info);
839	rds_info_register_func(RDS_INFO_SEND_MESSAGES,
840			       rds_conn_message_info_send);
841	rds_info_register_func(RDS_INFO_RETRANS_MESSAGES,
842			       rds_conn_message_info_retrans);
843#if IS_ENABLED(CONFIG_IPV6)
844	rds_info_register_func(RDS6_INFO_CONNECTIONS, rds6_conn_info);
845	rds_info_register_func(RDS6_INFO_SEND_MESSAGES,
846			       rds6_conn_message_info_send);
847	rds_info_register_func(RDS6_INFO_RETRANS_MESSAGES,
848			       rds6_conn_message_info_retrans);
849#endif
850	return 0;
851}
852
853void rds_conn_exit(void)
854{
855	rds_loop_net_exit(); /* unregister pernet callback */
856	rds_loop_exit();
857
858	WARN_ON(!hlist_empty(rds_conn_hash));
859
860	kmem_cache_destroy(rds_conn_slab);
861
862	rds_info_deregister_func(RDS_INFO_CONNECTIONS, rds_conn_info);
863	rds_info_deregister_func(RDS_INFO_SEND_MESSAGES,
864				 rds_conn_message_info_send);
865	rds_info_deregister_func(RDS_INFO_RETRANS_MESSAGES,
866				 rds_conn_message_info_retrans);
867#if IS_ENABLED(CONFIG_IPV6)
868	rds_info_deregister_func(RDS6_INFO_CONNECTIONS, rds6_conn_info);
869	rds_info_deregister_func(RDS6_INFO_SEND_MESSAGES,
870				 rds6_conn_message_info_send);
871	rds_info_deregister_func(RDS6_INFO_RETRANS_MESSAGES,
872				 rds6_conn_message_info_retrans);
873#endif
874}
875
876/*
877 * Force a disconnect
878 */
879void rds_conn_path_drop(struct rds_conn_path *cp, bool destroy)
880{
881	atomic_set(&cp->cp_state, RDS_CONN_ERROR);
882
883	rcu_read_lock();
884	if (!destroy && rds_destroy_pending(cp->cp_conn)) {
885		rcu_read_unlock();
886		return;
887	}
888	queue_work(rds_wq, &cp->cp_down_w);
889	rcu_read_unlock();
890}
891EXPORT_SYMBOL_GPL(rds_conn_path_drop);
892
893void rds_conn_drop(struct rds_connection *conn)
894{
895	WARN_ON(conn->c_trans->t_mp_capable);
896	rds_conn_path_drop(&conn->c_path[0], false);
897}
898EXPORT_SYMBOL_GPL(rds_conn_drop);
899
900/*
901 * If the connection is down, trigger a connect. We may have scheduled a
902 * delayed reconnect however - in this case we should not interfere.
903 */
904void rds_conn_path_connect_if_down(struct rds_conn_path *cp)
905{
906	rcu_read_lock();
907	if (rds_destroy_pending(cp->cp_conn)) {
908		rcu_read_unlock();
909		return;
910	}
911	if (rds_conn_path_state(cp) == RDS_CONN_DOWN &&
912	    !test_and_set_bit(RDS_RECONNECT_PENDING, &cp->cp_flags))
913		queue_delayed_work(rds_wq, &cp->cp_conn_w, 0);
914	rcu_read_unlock();
915}
916EXPORT_SYMBOL_GPL(rds_conn_path_connect_if_down);
917
918/* Check connectivity of all paths
919 */
920void rds_check_all_paths(struct rds_connection *conn)
921{
922	int i = 0;
923
924	do {
925		rds_conn_path_connect_if_down(&conn->c_path[i]);
926	} while (++i < conn->c_npaths);
927}
928
929void rds_conn_connect_if_down(struct rds_connection *conn)
930{
931	WARN_ON(conn->c_trans->t_mp_capable);
932	rds_conn_path_connect_if_down(&conn->c_path[0]);
933}
934EXPORT_SYMBOL_GPL(rds_conn_connect_if_down);
935
936void
937__rds_conn_path_error(struct rds_conn_path *cp, const char *fmt, ...)
938{
939	va_list ap;
940
941	va_start(ap, fmt);
942	vprintk(fmt, ap);
943	va_end(ap);
944
945	rds_conn_path_drop(cp, false);
946}