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