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v3.5.6
  1/*
  2 * Copyright (c) 2006 Oracle.  All rights reserved.
  3 *
  4 * This software is available to you under a choice of one of two
  5 * licenses.  You may choose to be licensed under the terms of the GNU
  6 * General Public License (GPL) Version 2, available from the file
  7 * COPYING in the main directory of this source tree, or the
  8 * OpenIB.org BSD license below:
  9 *
 10 *     Redistribution and use in source and binary forms, with or
 11 *     without modification, are permitted provided that the following
 12 *     conditions are met:
 13 *
 14 *      - Redistributions of source code must retain the above
 15 *        copyright notice, this list of conditions and the following
 16 *        disclaimer.
 17 *
 18 *      - Redistributions in binary form must reproduce the above
 19 *        copyright notice, this list of conditions and the following
 20 *        disclaimer in the documentation and/or other materials
 21 *        provided with the distribution.
 22 *
 23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 30 * SOFTWARE.
 31 *
 32 */
 33#include <linux/kernel.h>
 34#include <linux/slab.h>
 35#include <net/sock.h>
 36#include <linux/in.h>
 37#include <linux/export.h>
 
 
 
 38
 39#include "rds.h"
 40
 41void rds_inc_init(struct rds_incoming *inc, struct rds_connection *conn,
 42		  __be32 saddr)
 43{
 44	atomic_set(&inc->i_refcount, 1);
 45	INIT_LIST_HEAD(&inc->i_item);
 46	inc->i_conn = conn;
 47	inc->i_saddr = saddr;
 48	inc->i_rdma_cookie = 0;
 
 
 
 49}
 50EXPORT_SYMBOL_GPL(rds_inc_init);
 51
 
 
 
 
 
 
 
 
 
 
 
 
 
 52static void rds_inc_addref(struct rds_incoming *inc)
 53{
 54	rdsdebug("addref inc %p ref %d\n", inc, atomic_read(&inc->i_refcount));
 55	atomic_inc(&inc->i_refcount);
 56}
 57
 58void rds_inc_put(struct rds_incoming *inc)
 59{
 60	rdsdebug("put inc %p ref %d\n", inc, atomic_read(&inc->i_refcount));
 61	if (atomic_dec_and_test(&inc->i_refcount)) {
 62		BUG_ON(!list_empty(&inc->i_item));
 63
 64		inc->i_conn->c_trans->inc_free(inc);
 65	}
 66}
 67EXPORT_SYMBOL_GPL(rds_inc_put);
 68
 69static void rds_recv_rcvbuf_delta(struct rds_sock *rs, struct sock *sk,
 70				  struct rds_cong_map *map,
 71				  int delta, __be16 port)
 72{
 73	int now_congested;
 74
 75	if (delta == 0)
 76		return;
 77
 78	rs->rs_rcv_bytes += delta;
 
 
 
 
 
 
 
 
 
 79	now_congested = rs->rs_rcv_bytes > rds_sk_rcvbuf(rs);
 80
 81	rdsdebug("rs %p (%pI4:%u) recv bytes %d buf %d "
 82	  "now_cong %d delta %d\n",
 83	  rs, &rs->rs_bound_addr,
 84	  ntohs(rs->rs_bound_port), rs->rs_rcv_bytes,
 85	  rds_sk_rcvbuf(rs), now_congested, delta);
 86
 87	/* wasn't -> am congested */
 88	if (!rs->rs_congested && now_congested) {
 89		rs->rs_congested = 1;
 90		rds_cong_set_bit(map, port);
 91		rds_cong_queue_updates(map);
 92	}
 93	/* was -> aren't congested */
 94	/* Require more free space before reporting uncongested to prevent
 95	   bouncing cong/uncong state too often */
 96	else if (rs->rs_congested && (rs->rs_rcv_bytes < (rds_sk_rcvbuf(rs)/2))) {
 97		rs->rs_congested = 0;
 98		rds_cong_clear_bit(map, port);
 99		rds_cong_queue_updates(map);
100	}
101
102	/* do nothing if no change in cong state */
103}
104
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
105/*
106 * Process all extension headers that come with this message.
107 */
108static void rds_recv_incoming_exthdrs(struct rds_incoming *inc, struct rds_sock *rs)
109{
110	struct rds_header *hdr = &inc->i_hdr;
111	unsigned int pos = 0, type, len;
112	union {
113		struct rds_ext_header_version version;
114		struct rds_ext_header_rdma rdma;
115		struct rds_ext_header_rdma_dest rdma_dest;
116	} buffer;
117
118	while (1) {
119		len = sizeof(buffer);
120		type = rds_message_next_extension(hdr, &pos, &buffer, &len);
121		if (type == RDS_EXTHDR_NONE)
122			break;
123		/* Process extension header here */
124		switch (type) {
125		case RDS_EXTHDR_RDMA:
126			rds_rdma_unuse(rs, be32_to_cpu(buffer.rdma.h_rdma_rkey), 0);
127			break;
128
129		case RDS_EXTHDR_RDMA_DEST:
130			/* We ignore the size for now. We could stash it
131			 * somewhere and use it for error checking. */
132			inc->i_rdma_cookie = rds_rdma_make_cookie(
133					be32_to_cpu(buffer.rdma_dest.h_rdma_rkey),
134					be32_to_cpu(buffer.rdma_dest.h_rdma_offset));
135
136			break;
137		}
138	}
139}
140
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
141/*
142 * The transport must make sure that this is serialized against other
143 * rx and conn reset on this specific conn.
144 *
145 * We currently assert that only one fragmented message will be sent
146 * down a connection at a time.  This lets us reassemble in the conn
147 * instead of per-flow which means that we don't have to go digging through
148 * flows to tear down partial reassembly progress on conn failure and
149 * we save flow lookup and locking for each frag arrival.  It does mean
150 * that small messages will wait behind large ones.  Fragmenting at all
151 * is only to reduce the memory consumption of pre-posted buffers.
152 *
153 * The caller passes in saddr and daddr instead of us getting it from the
154 * conn.  This lets loopback, who only has one conn for both directions,
155 * tell us which roles the addrs in the conn are playing for this message.
156 */
157void rds_recv_incoming(struct rds_connection *conn, __be32 saddr, __be32 daddr,
 
158		       struct rds_incoming *inc, gfp_t gfp)
159{
160	struct rds_sock *rs = NULL;
161	struct sock *sk;
162	unsigned long flags;
 
163
164	inc->i_conn = conn;
165	inc->i_rx_jiffies = jiffies;
 
 
 
 
166
167	rdsdebug("conn %p next %llu inc %p seq %llu len %u sport %u dport %u "
168		 "flags 0x%x rx_jiffies %lu\n", conn,
169		 (unsigned long long)conn->c_next_rx_seq,
170		 inc,
171		 (unsigned long long)be64_to_cpu(inc->i_hdr.h_sequence),
172		 be32_to_cpu(inc->i_hdr.h_len),
173		 be16_to_cpu(inc->i_hdr.h_sport),
174		 be16_to_cpu(inc->i_hdr.h_dport),
175		 inc->i_hdr.h_flags,
176		 inc->i_rx_jiffies);
177
178	/*
179	 * Sequence numbers should only increase.  Messages get their
180	 * sequence number as they're queued in a sending conn.  They
181	 * can be dropped, though, if the sending socket is closed before
182	 * they hit the wire.  So sequence numbers can skip forward
183	 * under normal operation.  They can also drop back in the conn
184	 * failover case as previously sent messages are resent down the
185	 * new instance of a conn.  We drop those, otherwise we have
186	 * to assume that the next valid seq does not come after a
187	 * hole in the fragment stream.
188	 *
189	 * The headers don't give us a way to realize if fragments of
190	 * a message have been dropped.  We assume that frags that arrive
191	 * to a flow are part of the current message on the flow that is
192	 * being reassembled.  This means that senders can't drop messages
193	 * from the sending conn until all their frags are sent.
194	 *
195	 * XXX we could spend more on the wire to get more robust failure
196	 * detection, arguably worth it to avoid data corruption.
197	 */
198	if (be64_to_cpu(inc->i_hdr.h_sequence) < conn->c_next_rx_seq &&
199	    (inc->i_hdr.h_flags & RDS_FLAG_RETRANSMITTED)) {
200		rds_stats_inc(s_recv_drop_old_seq);
201		goto out;
202	}
203	conn->c_next_rx_seq = be64_to_cpu(inc->i_hdr.h_sequence) + 1;
204
205	if (rds_sysctl_ping_enable && inc->i_hdr.h_dport == 0) {
 
 
 
 
 
206		rds_stats_inc(s_recv_ping);
207		rds_send_pong(conn, inc->i_hdr.h_sport);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
208		goto out;
209	}
210
211	rs = rds_find_bound(daddr, inc->i_hdr.h_dport);
212	if (!rs) {
213		rds_stats_inc(s_recv_drop_no_sock);
214		goto out;
215	}
216
217	/* Process extension headers */
218	rds_recv_incoming_exthdrs(inc, rs);
219
220	/* We can be racing with rds_release() which marks the socket dead. */
221	sk = rds_rs_to_sk(rs);
222
223	/* serialize with rds_release -> sock_orphan */
224	write_lock_irqsave(&rs->rs_recv_lock, flags);
225	if (!sock_flag(sk, SOCK_DEAD)) {
226		rdsdebug("adding inc %p to rs %p's recv queue\n", inc, rs);
227		rds_stats_inc(s_recv_queued);
228		rds_recv_rcvbuf_delta(rs, sk, inc->i_conn->c_lcong,
229				      be32_to_cpu(inc->i_hdr.h_len),
230				      inc->i_hdr.h_dport);
 
 
231		rds_inc_addref(inc);
 
232		list_add_tail(&inc->i_item, &rs->rs_recv_queue);
233		__rds_wake_sk_sleep(sk);
234	} else {
235		rds_stats_inc(s_recv_drop_dead_sock);
236	}
237	write_unlock_irqrestore(&rs->rs_recv_lock, flags);
238
239out:
240	if (rs)
241		rds_sock_put(rs);
242}
243EXPORT_SYMBOL_GPL(rds_recv_incoming);
244
245/*
246 * be very careful here.  This is being called as the condition in
247 * wait_event_*() needs to cope with being called many times.
248 */
249static int rds_next_incoming(struct rds_sock *rs, struct rds_incoming **inc)
250{
251	unsigned long flags;
252
253	if (!*inc) {
254		read_lock_irqsave(&rs->rs_recv_lock, flags);
255		if (!list_empty(&rs->rs_recv_queue)) {
256			*inc = list_entry(rs->rs_recv_queue.next,
257					  struct rds_incoming,
258					  i_item);
259			rds_inc_addref(*inc);
260		}
261		read_unlock_irqrestore(&rs->rs_recv_lock, flags);
262	}
263
264	return *inc != NULL;
265}
266
267static int rds_still_queued(struct rds_sock *rs, struct rds_incoming *inc,
268			    int drop)
269{
270	struct sock *sk = rds_rs_to_sk(rs);
271	int ret = 0;
272	unsigned long flags;
 
273
274	write_lock_irqsave(&rs->rs_recv_lock, flags);
275	if (!list_empty(&inc->i_item)) {
276		ret = 1;
277		if (drop) {
278			/* XXX make sure this i_conn is reliable */
279			rds_recv_rcvbuf_delta(rs, sk, inc->i_conn->c_lcong,
280					      -be32_to_cpu(inc->i_hdr.h_len),
281					      inc->i_hdr.h_dport);
282			list_del_init(&inc->i_item);
283			rds_inc_put(inc);
284		}
285	}
286	write_unlock_irqrestore(&rs->rs_recv_lock, flags);
287
 
 
 
288	rdsdebug("inc %p rs %p still %d dropped %d\n", inc, rs, ret, drop);
289	return ret;
290}
291
292/*
293 * Pull errors off the error queue.
294 * If msghdr is NULL, we will just purge the error queue.
295 */
296int rds_notify_queue_get(struct rds_sock *rs, struct msghdr *msghdr)
297{
298	struct rds_notifier *notifier;
299	struct rds_rdma_notify cmsg = { 0 }; /* fill holes with zero */
300	unsigned int count = 0, max_messages = ~0U;
301	unsigned long flags;
302	LIST_HEAD(copy);
303	int err = 0;
304
 
305
306	/* put_cmsg copies to user space and thus may sleep. We can't do this
307	 * with rs_lock held, so first grab as many notifications as we can stuff
308	 * in the user provided cmsg buffer. We don't try to copy more, to avoid
309	 * losing notifications - except when the buffer is so small that it wouldn't
310	 * even hold a single notification. Then we give him as much of this single
311	 * msg as we can squeeze in, and set MSG_CTRUNC.
312	 */
313	if (msghdr) {
314		max_messages = msghdr->msg_controllen / CMSG_SPACE(sizeof(cmsg));
315		if (!max_messages)
316			max_messages = 1;
317	}
318
319	spin_lock_irqsave(&rs->rs_lock, flags);
320	while (!list_empty(&rs->rs_notify_queue) && count < max_messages) {
321		notifier = list_entry(rs->rs_notify_queue.next,
322				struct rds_notifier, n_list);
323		list_move(&notifier->n_list, &copy);
324		count++;
325	}
326	spin_unlock_irqrestore(&rs->rs_lock, flags);
327
328	if (!count)
329		return 0;
330
331	while (!list_empty(&copy)) {
332		notifier = list_entry(copy.next, struct rds_notifier, n_list);
333
334		if (msghdr) {
335			cmsg.user_token = notifier->n_user_token;
336			cmsg.status = notifier->n_status;
337
338			err = put_cmsg(msghdr, SOL_RDS, RDS_CMSG_RDMA_STATUS,
339				       sizeof(cmsg), &cmsg);
340			if (err)
341				break;
342		}
343
344		list_del_init(&notifier->n_list);
345		kfree(notifier);
346	}
347
348	/* If we bailed out because of an error in put_cmsg,
349	 * we may be left with one or more notifications that we
350	 * didn't process. Return them to the head of the list. */
351	if (!list_empty(&copy)) {
352		spin_lock_irqsave(&rs->rs_lock, flags);
353		list_splice(&copy, &rs->rs_notify_queue);
354		spin_unlock_irqrestore(&rs->rs_lock, flags);
355	}
356
357	return err;
358}
359
360/*
361 * Queue a congestion notification
362 */
363static int rds_notify_cong(struct rds_sock *rs, struct msghdr *msghdr)
364{
365	uint64_t notify = rs->rs_cong_notify;
366	unsigned long flags;
367	int err;
368
369	err = put_cmsg(msghdr, SOL_RDS, RDS_CMSG_CONG_UPDATE,
370			sizeof(notify), &notify);
371	if (err)
372		return err;
373
374	spin_lock_irqsave(&rs->rs_lock, flags);
375	rs->rs_cong_notify &= ~notify;
376	spin_unlock_irqrestore(&rs->rs_lock, flags);
377
378	return 0;
379}
380
381/*
382 * Receive any control messages.
383 */
384static int rds_cmsg_recv(struct rds_incoming *inc, struct msghdr *msg)
 
385{
386	int ret = 0;
387
388	if (inc->i_rdma_cookie) {
389		ret = put_cmsg(msg, SOL_RDS, RDS_CMSG_RDMA_DEST,
390				sizeof(inc->i_rdma_cookie), &inc->i_rdma_cookie);
 
391		if (ret)
392			return ret;
393	}
394
395	return 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
396}
397
398int rds_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
399		size_t size, int msg_flags)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
400{
401	struct sock *sk = sock->sk;
402	struct rds_sock *rs = rds_sk_to_rs(sk);
403	long timeo;
404	int ret = 0, nonblock = msg_flags & MSG_DONTWAIT;
405	struct sockaddr_in *sin;
 
406	struct rds_incoming *inc = NULL;
407
408	/* udp_recvmsg()->sock_recvtimeo() gets away without locking too.. */
409	timeo = sock_rcvtimeo(sk, nonblock);
410
411	rdsdebug("size %zu flags 0x%x timeo %ld\n", size, msg_flags, timeo);
412
413	msg->msg_namelen = 0;
414
415	if (msg_flags & MSG_OOB)
416		goto out;
 
 
417
418	while (1) {
419		/* If there are pending notifications, do those - and nothing else */
420		if (!list_empty(&rs->rs_notify_queue)) {
421			ret = rds_notify_queue_get(rs, msg);
422			break;
423		}
424
425		if (rs->rs_cong_notify) {
426			ret = rds_notify_cong(rs, msg);
427			break;
428		}
429
430		if (!rds_next_incoming(rs, &inc)) {
431			if (nonblock) {
432				ret = -EAGAIN;
 
 
433				break;
434			}
435
436			timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
437					(!list_empty(&rs->rs_notify_queue) ||
438					 rs->rs_cong_notify ||
439					 rds_next_incoming(rs, &inc)), timeo);
440			rdsdebug("recvmsg woke inc %p timeo %ld\n", inc,
441				 timeo);
442			if (timeo > 0 || timeo == MAX_SCHEDULE_TIMEOUT)
443				continue;
444
445			ret = timeo;
446			if (ret == 0)
447				ret = -ETIMEDOUT;
448			break;
449		}
450
451		rdsdebug("copying inc %p from %pI4:%u to user\n", inc,
452			 &inc->i_conn->c_faddr,
453			 ntohs(inc->i_hdr.h_sport));
454		ret = inc->i_conn->c_trans->inc_copy_to_user(inc, msg->msg_iov,
455							     size);
456		if (ret < 0)
457			break;
458
459		/*
460		 * if the message we just copied isn't at the head of the
461		 * recv queue then someone else raced us to return it, try
462		 * to get the next message.
463		 */
464		if (!rds_still_queued(rs, inc, !(msg_flags & MSG_PEEK))) {
465			rds_inc_put(inc);
466			inc = NULL;
467			rds_stats_inc(s_recv_deliver_raced);
 
468			continue;
469		}
470
471		if (ret < be32_to_cpu(inc->i_hdr.h_len)) {
472			if (msg_flags & MSG_TRUNC)
473				ret = be32_to_cpu(inc->i_hdr.h_len);
474			msg->msg_flags |= MSG_TRUNC;
475		}
476
477		if (rds_cmsg_recv(inc, msg)) {
478			ret = -EFAULT;
479			goto out;
480		}
 
481
482		rds_stats_inc(s_recv_delivered);
483
484		sin = (struct sockaddr_in *)msg->msg_name;
485		if (sin) {
486			sin->sin_family = AF_INET;
487			sin->sin_port = inc->i_hdr.h_sport;
488			sin->sin_addr.s_addr = inc->i_saddr;
489			memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
490			msg->msg_namelen = sizeof(*sin);
 
 
 
 
 
 
 
 
 
491		}
492		break;
493	}
494
495	if (inc)
496		rds_inc_put(inc);
497
498out:
499	return ret;
500}
501
502/*
503 * The socket is being shut down and we're asked to drop messages that were
504 * queued for recvmsg.  The caller has unbound the socket so the receive path
505 * won't queue any more incoming fragments or messages on the socket.
506 */
507void rds_clear_recv_queue(struct rds_sock *rs)
508{
509	struct sock *sk = rds_rs_to_sk(rs);
510	struct rds_incoming *inc, *tmp;
511	unsigned long flags;
 
512
513	write_lock_irqsave(&rs->rs_recv_lock, flags);
514	list_for_each_entry_safe(inc, tmp, &rs->rs_recv_queue, i_item) {
515		rds_recv_rcvbuf_delta(rs, sk, inc->i_conn->c_lcong,
516				      -be32_to_cpu(inc->i_hdr.h_len),
517				      inc->i_hdr.h_dport);
 
 
 
 
 
518		list_del_init(&inc->i_item);
519		rds_inc_put(inc);
520	}
521	write_unlock_irqrestore(&rs->rs_recv_lock, flags);
522}
523
524/*
525 * inc->i_saddr isn't used here because it is only set in the receive
526 * path.
527 */
528void rds_inc_info_copy(struct rds_incoming *inc,
529		       struct rds_info_iterator *iter,
530		       __be32 saddr, __be32 daddr, int flip)
531{
532	struct rds_info_message minfo;
533
534	minfo.seq = be64_to_cpu(inc->i_hdr.h_sequence);
535	minfo.len = be32_to_cpu(inc->i_hdr.h_len);
 
536
537	if (flip) {
538		minfo.laddr = daddr;
539		minfo.faddr = saddr;
540		minfo.lport = inc->i_hdr.h_dport;
541		minfo.fport = inc->i_hdr.h_sport;
542	} else {
543		minfo.laddr = saddr;
544		minfo.faddr = daddr;
545		minfo.lport = inc->i_hdr.h_sport;
546		minfo.fport = inc->i_hdr.h_dport;
547	}
548
 
 
549	rds_info_copy(iter, &minfo, sizeof(minfo));
550}
v6.13.7
  1/*
  2 * Copyright (c) 2006, 2019 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/slab.h>
 35#include <net/sock.h>
 36#include <linux/in.h>
 37#include <linux/export.h>
 38#include <linux/sched/clock.h>
 39#include <linux/time.h>
 40#include <linux/rds.h>
 41
 42#include "rds.h"
 43
 44void rds_inc_init(struct rds_incoming *inc, struct rds_connection *conn,
 45		 struct in6_addr *saddr)
 46{
 47	refcount_set(&inc->i_refcount, 1);
 48	INIT_LIST_HEAD(&inc->i_item);
 49	inc->i_conn = conn;
 50	inc->i_saddr = *saddr;
 51	inc->i_usercopy.rdma_cookie = 0;
 52	inc->i_usercopy.rx_tstamp = ktime_set(0, 0);
 53
 54	memset(inc->i_rx_lat_trace, 0, sizeof(inc->i_rx_lat_trace));
 55}
 56EXPORT_SYMBOL_GPL(rds_inc_init);
 57
 58void rds_inc_path_init(struct rds_incoming *inc, struct rds_conn_path *cp,
 59		       struct in6_addr  *saddr)
 60{
 61	refcount_set(&inc->i_refcount, 1);
 62	INIT_LIST_HEAD(&inc->i_item);
 63	inc->i_conn = cp->cp_conn;
 64	inc->i_conn_path = cp;
 65	inc->i_saddr = *saddr;
 66	inc->i_usercopy.rdma_cookie = 0;
 67	inc->i_usercopy.rx_tstamp = ktime_set(0, 0);
 68}
 69EXPORT_SYMBOL_GPL(rds_inc_path_init);
 70
 71static void rds_inc_addref(struct rds_incoming *inc)
 72{
 73	rdsdebug("addref inc %p ref %d\n", inc, refcount_read(&inc->i_refcount));
 74	refcount_inc(&inc->i_refcount);
 75}
 76
 77void rds_inc_put(struct rds_incoming *inc)
 78{
 79	rdsdebug("put inc %p ref %d\n", inc, refcount_read(&inc->i_refcount));
 80	if (refcount_dec_and_test(&inc->i_refcount)) {
 81		BUG_ON(!list_empty(&inc->i_item));
 82
 83		inc->i_conn->c_trans->inc_free(inc);
 84	}
 85}
 86EXPORT_SYMBOL_GPL(rds_inc_put);
 87
 88static void rds_recv_rcvbuf_delta(struct rds_sock *rs, struct sock *sk,
 89				  struct rds_cong_map *map,
 90				  int delta, __be16 port)
 91{
 92	int now_congested;
 93
 94	if (delta == 0)
 95		return;
 96
 97	rs->rs_rcv_bytes += delta;
 98	if (delta > 0)
 99		rds_stats_add(s_recv_bytes_added_to_socket, delta);
100	else
101		rds_stats_add(s_recv_bytes_removed_from_socket, -delta);
102
103	/* loop transport doesn't send/recv congestion updates */
104	if (rs->rs_transport->t_type == RDS_TRANS_LOOP)
105		return;
106
107	now_congested = rs->rs_rcv_bytes > rds_sk_rcvbuf(rs);
108
109	rdsdebug("rs %p (%pI6c:%u) recv bytes %d buf %d "
110	  "now_cong %d delta %d\n",
111	  rs, &rs->rs_bound_addr,
112	  ntohs(rs->rs_bound_port), rs->rs_rcv_bytes,
113	  rds_sk_rcvbuf(rs), now_congested, delta);
114
115	/* wasn't -> am congested */
116	if (!rs->rs_congested && now_congested) {
117		rs->rs_congested = 1;
118		rds_cong_set_bit(map, port);
119		rds_cong_queue_updates(map);
120	}
121	/* was -> aren't congested */
122	/* Require more free space before reporting uncongested to prevent
123	   bouncing cong/uncong state too often */
124	else if (rs->rs_congested && (rs->rs_rcv_bytes < (rds_sk_rcvbuf(rs)/2))) {
125		rs->rs_congested = 0;
126		rds_cong_clear_bit(map, port);
127		rds_cong_queue_updates(map);
128	}
129
130	/* do nothing if no change in cong state */
131}
132
133static void rds_conn_peer_gen_update(struct rds_connection *conn,
134				     u32 peer_gen_num)
135{
136	int i;
137	struct rds_message *rm, *tmp;
138	unsigned long flags;
139
140	WARN_ON(conn->c_trans->t_type != RDS_TRANS_TCP);
141	if (peer_gen_num != 0) {
142		if (conn->c_peer_gen_num != 0 &&
143		    peer_gen_num != conn->c_peer_gen_num) {
144			for (i = 0; i < RDS_MPATH_WORKERS; i++) {
145				struct rds_conn_path *cp;
146
147				cp = &conn->c_path[i];
148				spin_lock_irqsave(&cp->cp_lock, flags);
149				cp->cp_next_tx_seq = 1;
150				cp->cp_next_rx_seq = 0;
151				list_for_each_entry_safe(rm, tmp,
152							 &cp->cp_retrans,
153							 m_conn_item) {
154					set_bit(RDS_MSG_FLUSH, &rm->m_flags);
155				}
156				spin_unlock_irqrestore(&cp->cp_lock, flags);
157			}
158		}
159		conn->c_peer_gen_num = peer_gen_num;
160	}
161}
162
163/*
164 * Process all extension headers that come with this message.
165 */
166static void rds_recv_incoming_exthdrs(struct rds_incoming *inc, struct rds_sock *rs)
167{
168	struct rds_header *hdr = &inc->i_hdr;
169	unsigned int pos = 0, type, len;
170	union {
171		struct rds_ext_header_version version;
172		struct rds_ext_header_rdma rdma;
173		struct rds_ext_header_rdma_dest rdma_dest;
174	} buffer;
175
176	while (1) {
177		len = sizeof(buffer);
178		type = rds_message_next_extension(hdr, &pos, &buffer, &len);
179		if (type == RDS_EXTHDR_NONE)
180			break;
181		/* Process extension header here */
182		switch (type) {
183		case RDS_EXTHDR_RDMA:
184			rds_rdma_unuse(rs, be32_to_cpu(buffer.rdma.h_rdma_rkey), 0);
185			break;
186
187		case RDS_EXTHDR_RDMA_DEST:
188			/* We ignore the size for now. We could stash it
189			 * somewhere and use it for error checking. */
190			inc->i_usercopy.rdma_cookie = rds_rdma_make_cookie(
191					be32_to_cpu(buffer.rdma_dest.h_rdma_rkey),
192					be32_to_cpu(buffer.rdma_dest.h_rdma_offset));
193
194			break;
195		}
196	}
197}
198
199static void rds_recv_hs_exthdrs(struct rds_header *hdr,
200				struct rds_connection *conn)
201{
202	unsigned int pos = 0, type, len;
203	union {
204		struct rds_ext_header_version version;
205		u16 rds_npaths;
206		u32 rds_gen_num;
207	} buffer;
208	u32 new_peer_gen_num = 0;
209
210	while (1) {
211		len = sizeof(buffer);
212		type = rds_message_next_extension(hdr, &pos, &buffer, &len);
213		if (type == RDS_EXTHDR_NONE)
214			break;
215		/* Process extension header here */
216		switch (type) {
217		case RDS_EXTHDR_NPATHS:
218			conn->c_npaths = min_t(int, RDS_MPATH_WORKERS,
219					       be16_to_cpu(buffer.rds_npaths));
220			break;
221		case RDS_EXTHDR_GEN_NUM:
222			new_peer_gen_num = be32_to_cpu(buffer.rds_gen_num);
223			break;
224		default:
225			pr_warn_ratelimited("ignoring unknown exthdr type "
226					     "0x%x\n", type);
227		}
228	}
229	/* if RDS_EXTHDR_NPATHS was not found, default to a single-path */
230	conn->c_npaths = max_t(int, conn->c_npaths, 1);
231	conn->c_ping_triggered = 0;
232	rds_conn_peer_gen_update(conn, new_peer_gen_num);
233}
234
235/* rds_start_mprds() will synchronously start multiple paths when appropriate.
236 * The scheme is based on the following rules:
237 *
238 * 1. rds_sendmsg on first connect attempt sends the probe ping, with the
239 *    sender's npaths (s_npaths)
240 * 2. rcvr of probe-ping knows the mprds_paths = min(s_npaths, r_npaths). It
241 *    sends back a probe-pong with r_npaths. After that, if rcvr is the
242 *    smaller ip addr, it starts rds_conn_path_connect_if_down on all
243 *    mprds_paths.
244 * 3. sender gets woken up, and can move to rds_conn_path_connect_if_down.
245 *    If it is the smaller ipaddr, rds_conn_path_connect_if_down can be
246 *    called after reception of the probe-pong on all mprds_paths.
247 *    Otherwise (sender of probe-ping is not the smaller ip addr): just call
248 *    rds_conn_path_connect_if_down on the hashed path. (see rule 4)
249 * 4. rds_connect_worker must only trigger a connection if laddr < faddr.
250 * 5. sender may end up queuing the packet on the cp. will get sent out later.
251 *    when connection is completed.
252 */
253static void rds_start_mprds(struct rds_connection *conn)
254{
255	int i;
256	struct rds_conn_path *cp;
257
258	if (conn->c_npaths > 1 &&
259	    rds_addr_cmp(&conn->c_laddr, &conn->c_faddr) < 0) {
260		for (i = 0; i < conn->c_npaths; i++) {
261			cp = &conn->c_path[i];
262			rds_conn_path_connect_if_down(cp);
263		}
264	}
265}
266
267/*
268 * The transport must make sure that this is serialized against other
269 * rx and conn reset on this specific conn.
270 *
271 * We currently assert that only one fragmented message will be sent
272 * down a connection at a time.  This lets us reassemble in the conn
273 * instead of per-flow which means that we don't have to go digging through
274 * flows to tear down partial reassembly progress on conn failure and
275 * we save flow lookup and locking for each frag arrival.  It does mean
276 * that small messages will wait behind large ones.  Fragmenting at all
277 * is only to reduce the memory consumption of pre-posted buffers.
278 *
279 * The caller passes in saddr and daddr instead of us getting it from the
280 * conn.  This lets loopback, who only has one conn for both directions,
281 * tell us which roles the addrs in the conn are playing for this message.
282 */
283void rds_recv_incoming(struct rds_connection *conn, struct in6_addr *saddr,
284		       struct in6_addr *daddr,
285		       struct rds_incoming *inc, gfp_t gfp)
286{
287	struct rds_sock *rs = NULL;
288	struct sock *sk;
289	unsigned long flags;
290	struct rds_conn_path *cp;
291
292	inc->i_conn = conn;
293	inc->i_rx_jiffies = jiffies;
294	if (conn->c_trans->t_mp_capable)
295		cp = inc->i_conn_path;
296	else
297		cp = &conn->c_path[0];
298
299	rdsdebug("conn %p next %llu inc %p seq %llu len %u sport %u dport %u "
300		 "flags 0x%x rx_jiffies %lu\n", conn,
301		 (unsigned long long)cp->cp_next_rx_seq,
302		 inc,
303		 (unsigned long long)be64_to_cpu(inc->i_hdr.h_sequence),
304		 be32_to_cpu(inc->i_hdr.h_len),
305		 be16_to_cpu(inc->i_hdr.h_sport),
306		 be16_to_cpu(inc->i_hdr.h_dport),
307		 inc->i_hdr.h_flags,
308		 inc->i_rx_jiffies);
309
310	/*
311	 * Sequence numbers should only increase.  Messages get their
312	 * sequence number as they're queued in a sending conn.  They
313	 * can be dropped, though, if the sending socket is closed before
314	 * they hit the wire.  So sequence numbers can skip forward
315	 * under normal operation.  They can also drop back in the conn
316	 * failover case as previously sent messages are resent down the
317	 * new instance of a conn.  We drop those, otherwise we have
318	 * to assume that the next valid seq does not come after a
319	 * hole in the fragment stream.
320	 *
321	 * The headers don't give us a way to realize if fragments of
322	 * a message have been dropped.  We assume that frags that arrive
323	 * to a flow are part of the current message on the flow that is
324	 * being reassembled.  This means that senders can't drop messages
325	 * from the sending conn until all their frags are sent.
326	 *
327	 * XXX we could spend more on the wire to get more robust failure
328	 * detection, arguably worth it to avoid data corruption.
329	 */
330	if (be64_to_cpu(inc->i_hdr.h_sequence) < cp->cp_next_rx_seq &&
331	    (inc->i_hdr.h_flags & RDS_FLAG_RETRANSMITTED)) {
332		rds_stats_inc(s_recv_drop_old_seq);
333		goto out;
334	}
335	cp->cp_next_rx_seq = be64_to_cpu(inc->i_hdr.h_sequence) + 1;
336
337	if (rds_sysctl_ping_enable && inc->i_hdr.h_dport == 0) {
338		if (inc->i_hdr.h_sport == 0) {
339			rdsdebug("ignore ping with 0 sport from %pI6c\n",
340				 saddr);
341			goto out;
342		}
343		rds_stats_inc(s_recv_ping);
344		rds_send_pong(cp, inc->i_hdr.h_sport);
345		/* if this is a handshake ping, start multipath if necessary */
346		if (RDS_HS_PROBE(be16_to_cpu(inc->i_hdr.h_sport),
347				 be16_to_cpu(inc->i_hdr.h_dport))) {
348			rds_recv_hs_exthdrs(&inc->i_hdr, cp->cp_conn);
349			rds_start_mprds(cp->cp_conn);
350		}
351		goto out;
352	}
353
354	if (be16_to_cpu(inc->i_hdr.h_dport) ==  RDS_FLAG_PROBE_PORT &&
355	    inc->i_hdr.h_sport == 0) {
356		rds_recv_hs_exthdrs(&inc->i_hdr, cp->cp_conn);
357		/* if this is a handshake pong, start multipath if necessary */
358		rds_start_mprds(cp->cp_conn);
359		wake_up(&cp->cp_conn->c_hs_waitq);
360		goto out;
361	}
362
363	rs = rds_find_bound(daddr, inc->i_hdr.h_dport, conn->c_bound_if);
364	if (!rs) {
365		rds_stats_inc(s_recv_drop_no_sock);
366		goto out;
367	}
368
369	/* Process extension headers */
370	rds_recv_incoming_exthdrs(inc, rs);
371
372	/* We can be racing with rds_release() which marks the socket dead. */
373	sk = rds_rs_to_sk(rs);
374
375	/* serialize with rds_release -> sock_orphan */
376	write_lock_irqsave(&rs->rs_recv_lock, flags);
377	if (!sock_flag(sk, SOCK_DEAD)) {
378		rdsdebug("adding inc %p to rs %p's recv queue\n", inc, rs);
379		rds_stats_inc(s_recv_queued);
380		rds_recv_rcvbuf_delta(rs, sk, inc->i_conn->c_lcong,
381				      be32_to_cpu(inc->i_hdr.h_len),
382				      inc->i_hdr.h_dport);
383		if (sock_flag(sk, SOCK_RCVTSTAMP))
384			inc->i_usercopy.rx_tstamp = ktime_get_real();
385		rds_inc_addref(inc);
386		inc->i_rx_lat_trace[RDS_MSG_RX_END] = local_clock();
387		list_add_tail(&inc->i_item, &rs->rs_recv_queue);
388		__rds_wake_sk_sleep(sk);
389	} else {
390		rds_stats_inc(s_recv_drop_dead_sock);
391	}
392	write_unlock_irqrestore(&rs->rs_recv_lock, flags);
393
394out:
395	if (rs)
396		rds_sock_put(rs);
397}
398EXPORT_SYMBOL_GPL(rds_recv_incoming);
399
400/*
401 * be very careful here.  This is being called as the condition in
402 * wait_event_*() needs to cope with being called many times.
403 */
404static int rds_next_incoming(struct rds_sock *rs, struct rds_incoming **inc)
405{
406	unsigned long flags;
407
408	if (!*inc) {
409		read_lock_irqsave(&rs->rs_recv_lock, flags);
410		if (!list_empty(&rs->rs_recv_queue)) {
411			*inc = list_entry(rs->rs_recv_queue.next,
412					  struct rds_incoming,
413					  i_item);
414			rds_inc_addref(*inc);
415		}
416		read_unlock_irqrestore(&rs->rs_recv_lock, flags);
417	}
418
419	return *inc != NULL;
420}
421
422static int rds_still_queued(struct rds_sock *rs, struct rds_incoming *inc,
423			    int drop)
424{
425	struct sock *sk = rds_rs_to_sk(rs);
426	int ret = 0;
427	unsigned long flags;
428	struct rds_incoming *to_drop = NULL;
429
430	write_lock_irqsave(&rs->rs_recv_lock, flags);
431	if (!list_empty(&inc->i_item)) {
432		ret = 1;
433		if (drop) {
434			/* XXX make sure this i_conn is reliable */
435			rds_recv_rcvbuf_delta(rs, sk, inc->i_conn->c_lcong,
436					      -be32_to_cpu(inc->i_hdr.h_len),
437					      inc->i_hdr.h_dport);
438			list_del_init(&inc->i_item);
439			to_drop = inc;
440		}
441	}
442	write_unlock_irqrestore(&rs->rs_recv_lock, flags);
443
444	if (to_drop)
445		rds_inc_put(to_drop);
446
447	rdsdebug("inc %p rs %p still %d dropped %d\n", inc, rs, ret, drop);
448	return ret;
449}
450
451/*
452 * Pull errors off the error queue.
453 * If msghdr is NULL, we will just purge the error queue.
454 */
455int rds_notify_queue_get(struct rds_sock *rs, struct msghdr *msghdr)
456{
457	struct rds_notifier *notifier;
458	struct rds_rdma_notify cmsg;
459	unsigned int count = 0, max_messages = ~0U;
460	unsigned long flags;
461	LIST_HEAD(copy);
462	int err = 0;
463
464	memset(&cmsg, 0, sizeof(cmsg));	/* fill holes with zero */
465
466	/* put_cmsg copies to user space and thus may sleep. We can't do this
467	 * with rs_lock held, so first grab as many notifications as we can stuff
468	 * in the user provided cmsg buffer. We don't try to copy more, to avoid
469	 * losing notifications - except when the buffer is so small that it wouldn't
470	 * even hold a single notification. Then we give him as much of this single
471	 * msg as we can squeeze in, and set MSG_CTRUNC.
472	 */
473	if (msghdr) {
474		max_messages = msghdr->msg_controllen / CMSG_SPACE(sizeof(cmsg));
475		if (!max_messages)
476			max_messages = 1;
477	}
478
479	spin_lock_irqsave(&rs->rs_lock, flags);
480	while (!list_empty(&rs->rs_notify_queue) && count < max_messages) {
481		notifier = list_entry(rs->rs_notify_queue.next,
482				struct rds_notifier, n_list);
483		list_move(&notifier->n_list, &copy);
484		count++;
485	}
486	spin_unlock_irqrestore(&rs->rs_lock, flags);
487
488	if (!count)
489		return 0;
490
491	while (!list_empty(&copy)) {
492		notifier = list_entry(copy.next, struct rds_notifier, n_list);
493
494		if (msghdr) {
495			cmsg.user_token = notifier->n_user_token;
496			cmsg.status = notifier->n_status;
497
498			err = put_cmsg(msghdr, SOL_RDS, RDS_CMSG_RDMA_STATUS,
499				       sizeof(cmsg), &cmsg);
500			if (err)
501				break;
502		}
503
504		list_del_init(&notifier->n_list);
505		kfree(notifier);
506	}
507
508	/* If we bailed out because of an error in put_cmsg,
509	 * we may be left with one or more notifications that we
510	 * didn't process. Return them to the head of the list. */
511	if (!list_empty(&copy)) {
512		spin_lock_irqsave(&rs->rs_lock, flags);
513		list_splice(&copy, &rs->rs_notify_queue);
514		spin_unlock_irqrestore(&rs->rs_lock, flags);
515	}
516
517	return err;
518}
519
520/*
521 * Queue a congestion notification
522 */
523static int rds_notify_cong(struct rds_sock *rs, struct msghdr *msghdr)
524{
525	uint64_t notify = rs->rs_cong_notify;
526	unsigned long flags;
527	int err;
528
529	err = put_cmsg(msghdr, SOL_RDS, RDS_CMSG_CONG_UPDATE,
530			sizeof(notify), &notify);
531	if (err)
532		return err;
533
534	spin_lock_irqsave(&rs->rs_lock, flags);
535	rs->rs_cong_notify &= ~notify;
536	spin_unlock_irqrestore(&rs->rs_lock, flags);
537
538	return 0;
539}
540
541/*
542 * Receive any control messages.
543 */
544static int rds_cmsg_recv(struct rds_incoming *inc, struct msghdr *msg,
545			 struct rds_sock *rs)
546{
547	int ret = 0;
548
549	if (inc->i_usercopy.rdma_cookie) {
550		ret = put_cmsg(msg, SOL_RDS, RDS_CMSG_RDMA_DEST,
551				sizeof(inc->i_usercopy.rdma_cookie),
552				&inc->i_usercopy.rdma_cookie);
553		if (ret)
554			goto out;
555	}
556
557	if ((inc->i_usercopy.rx_tstamp != 0) &&
558	    sock_flag(rds_rs_to_sk(rs), SOCK_RCVTSTAMP)) {
559		struct __kernel_old_timeval tv =
560			ns_to_kernel_old_timeval(inc->i_usercopy.rx_tstamp);
561
562		if (!sock_flag(rds_rs_to_sk(rs), SOCK_TSTAMP_NEW)) {
563			ret = put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_OLD,
564				       sizeof(tv), &tv);
565		} else {
566			struct __kernel_sock_timeval sk_tv;
567
568			sk_tv.tv_sec = tv.tv_sec;
569			sk_tv.tv_usec = tv.tv_usec;
570
571			ret = put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_NEW,
572				       sizeof(sk_tv), &sk_tv);
573		}
574
575		if (ret)
576			goto out;
577	}
578
579	if (rs->rs_rx_traces) {
580		struct rds_cmsg_rx_trace t;
581		int i, j;
582
583		memset(&t, 0, sizeof(t));
584		inc->i_rx_lat_trace[RDS_MSG_RX_CMSG] = local_clock();
585		t.rx_traces =  rs->rs_rx_traces;
586		for (i = 0; i < rs->rs_rx_traces; i++) {
587			j = rs->rs_rx_trace[i];
588			t.rx_trace_pos[i] = j;
589			t.rx_trace[i] = inc->i_rx_lat_trace[j + 1] -
590					  inc->i_rx_lat_trace[j];
591		}
592
593		ret = put_cmsg(msg, SOL_RDS, RDS_CMSG_RXPATH_LATENCY,
594			       sizeof(t), &t);
595		if (ret)
596			goto out;
597	}
598
599out:
600	return ret;
601}
602
603static bool rds_recvmsg_zcookie(struct rds_sock *rs, struct msghdr *msg)
604{
605	struct rds_msg_zcopy_queue *q = &rs->rs_zcookie_queue;
606	struct rds_msg_zcopy_info *info = NULL;
607	struct rds_zcopy_cookies *done;
608	unsigned long flags;
609
610	if (!msg->msg_control)
611		return false;
612
613	if (!sock_flag(rds_rs_to_sk(rs), SOCK_ZEROCOPY) ||
614	    msg->msg_controllen < CMSG_SPACE(sizeof(*done)))
615		return false;
616
617	spin_lock_irqsave(&q->lock, flags);
618	if (!list_empty(&q->zcookie_head)) {
619		info = list_entry(q->zcookie_head.next,
620				  struct rds_msg_zcopy_info, rs_zcookie_next);
621		list_del(&info->rs_zcookie_next);
622	}
623	spin_unlock_irqrestore(&q->lock, flags);
624	if (!info)
625		return false;
626	done = &info->zcookies;
627	if (put_cmsg(msg, SOL_RDS, RDS_CMSG_ZCOPY_COMPLETION, sizeof(*done),
628		     done)) {
629		spin_lock_irqsave(&q->lock, flags);
630		list_add(&info->rs_zcookie_next, &q->zcookie_head);
631		spin_unlock_irqrestore(&q->lock, flags);
632		return false;
633	}
634	kfree(info);
635	return true;
636}
637
638int rds_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
639		int msg_flags)
640{
641	struct sock *sk = sock->sk;
642	struct rds_sock *rs = rds_sk_to_rs(sk);
643	long timeo;
644	int ret = 0, nonblock = msg_flags & MSG_DONTWAIT;
645	DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
646	DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
647	struct rds_incoming *inc = NULL;
648
649	/* udp_recvmsg()->sock_recvtimeo() gets away without locking too.. */
650	timeo = sock_rcvtimeo(sk, nonblock);
651
652	rdsdebug("size %zu flags 0x%x timeo %ld\n", size, msg_flags, timeo);
653
 
 
654	if (msg_flags & MSG_OOB)
655		goto out;
656	if (msg_flags & MSG_ERRQUEUE)
657		return sock_recv_errqueue(sk, msg, size, SOL_IP, IP_RECVERR);
658
659	while (1) {
660		/* If there are pending notifications, do those - and nothing else */
661		if (!list_empty(&rs->rs_notify_queue)) {
662			ret = rds_notify_queue_get(rs, msg);
663			break;
664		}
665
666		if (rs->rs_cong_notify) {
667			ret = rds_notify_cong(rs, msg);
668			break;
669		}
670
671		if (!rds_next_incoming(rs, &inc)) {
672			if (nonblock) {
673				bool reaped = rds_recvmsg_zcookie(rs, msg);
674
675				ret = reaped ?  0 : -EAGAIN;
676				break;
677			}
678
679			timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
680					(!list_empty(&rs->rs_notify_queue) ||
681					 rs->rs_cong_notify ||
682					 rds_next_incoming(rs, &inc)), timeo);
683			rdsdebug("recvmsg woke inc %p timeo %ld\n", inc,
684				 timeo);
685			if (timeo > 0 || timeo == MAX_SCHEDULE_TIMEOUT)
686				continue;
687
688			ret = timeo;
689			if (ret == 0)
690				ret = -ETIMEDOUT;
691			break;
692		}
693
694		rdsdebug("copying inc %p from %pI6c:%u to user\n", inc,
695			 &inc->i_conn->c_faddr,
696			 ntohs(inc->i_hdr.h_sport));
697		ret = inc->i_conn->c_trans->inc_copy_to_user(inc, &msg->msg_iter);
 
698		if (ret < 0)
699			break;
700
701		/*
702		 * if the message we just copied isn't at the head of the
703		 * recv queue then someone else raced us to return it, try
704		 * to get the next message.
705		 */
706		if (!rds_still_queued(rs, inc, !(msg_flags & MSG_PEEK))) {
707			rds_inc_put(inc);
708			inc = NULL;
709			rds_stats_inc(s_recv_deliver_raced);
710			iov_iter_revert(&msg->msg_iter, ret);
711			continue;
712		}
713
714		if (ret < be32_to_cpu(inc->i_hdr.h_len)) {
715			if (msg_flags & MSG_TRUNC)
716				ret = be32_to_cpu(inc->i_hdr.h_len);
717			msg->msg_flags |= MSG_TRUNC;
718		}
719
720		if (rds_cmsg_recv(inc, msg, rs)) {
721			ret = -EFAULT;
722			break;
723		}
724		rds_recvmsg_zcookie(rs, msg);
725
726		rds_stats_inc(s_recv_delivered);
727
728		if (msg->msg_name) {
729			if (ipv6_addr_v4mapped(&inc->i_saddr)) {
730				sin->sin_family = AF_INET;
731				sin->sin_port = inc->i_hdr.h_sport;
732				sin->sin_addr.s_addr =
733				    inc->i_saddr.s6_addr32[3];
734				memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
735				msg->msg_namelen = sizeof(*sin);
736			} else {
737				sin6->sin6_family = AF_INET6;
738				sin6->sin6_port = inc->i_hdr.h_sport;
739				sin6->sin6_addr = inc->i_saddr;
740				sin6->sin6_flowinfo = 0;
741				sin6->sin6_scope_id = rs->rs_bound_scope_id;
742				msg->msg_namelen = sizeof(*sin6);
743			}
744		}
745		break;
746	}
747
748	if (inc)
749		rds_inc_put(inc);
750
751out:
752	return ret;
753}
754
755/*
756 * The socket is being shut down and we're asked to drop messages that were
757 * queued for recvmsg.  The caller has unbound the socket so the receive path
758 * won't queue any more incoming fragments or messages on the socket.
759 */
760void rds_clear_recv_queue(struct rds_sock *rs)
761{
762	struct sock *sk = rds_rs_to_sk(rs);
763	struct rds_incoming *inc, *tmp;
764	unsigned long flags;
765	LIST_HEAD(to_drop);
766
767	write_lock_irqsave(&rs->rs_recv_lock, flags);
768	list_for_each_entry_safe(inc, tmp, &rs->rs_recv_queue, i_item) {
769		rds_recv_rcvbuf_delta(rs, sk, inc->i_conn->c_lcong,
770				      -be32_to_cpu(inc->i_hdr.h_len),
771				      inc->i_hdr.h_dport);
772		list_move(&inc->i_item, &to_drop);
773	}
774	write_unlock_irqrestore(&rs->rs_recv_lock, flags);
775
776	list_for_each_entry_safe(inc, tmp, &to_drop, i_item) {
777		list_del_init(&inc->i_item);
778		rds_inc_put(inc);
779	}
 
780}
781
782/*
783 * inc->i_saddr isn't used here because it is only set in the receive
784 * path.
785 */
786void rds_inc_info_copy(struct rds_incoming *inc,
787		       struct rds_info_iterator *iter,
788		       __be32 saddr, __be32 daddr, int flip)
789{
790	struct rds_info_message minfo;
791
792	minfo.seq = be64_to_cpu(inc->i_hdr.h_sequence);
793	minfo.len = be32_to_cpu(inc->i_hdr.h_len);
794	minfo.tos = inc->i_conn->c_tos;
795
796	if (flip) {
797		minfo.laddr = daddr;
798		minfo.faddr = saddr;
799		minfo.lport = inc->i_hdr.h_dport;
800		minfo.fport = inc->i_hdr.h_sport;
801	} else {
802		minfo.laddr = saddr;
803		minfo.faddr = daddr;
804		minfo.lport = inc->i_hdr.h_sport;
805		minfo.fport = inc->i_hdr.h_dport;
806	}
807
808	minfo.flags = 0;
809
810	rds_info_copy(iter, &minfo, sizeof(minfo));
811}
812
813#if IS_ENABLED(CONFIG_IPV6)
814void rds6_inc_info_copy(struct rds_incoming *inc,
815			struct rds_info_iterator *iter,
816			struct in6_addr *saddr, struct in6_addr *daddr,
817			int flip)
818{
819	struct rds6_info_message minfo6;
820
821	minfo6.seq = be64_to_cpu(inc->i_hdr.h_sequence);
822	minfo6.len = be32_to_cpu(inc->i_hdr.h_len);
823	minfo6.tos = inc->i_conn->c_tos;
824
825	if (flip) {
826		minfo6.laddr = *daddr;
827		minfo6.faddr = *saddr;
828		minfo6.lport = inc->i_hdr.h_dport;
829		minfo6.fport = inc->i_hdr.h_sport;
830	} else {
831		minfo6.laddr = *saddr;
832		minfo6.faddr = *daddr;
833		minfo6.lport = inc->i_hdr.h_sport;
834		minfo6.fport = inc->i_hdr.h_dport;
835	}
836
837	minfo6.flags = 0;
838
839	rds_info_copy(iter, &minfo6, sizeof(minfo6));
840}
841#endif