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(r: &inc->i_refcount, n: 1);
48 INIT_LIST_HEAD(list: &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(secs: 0, nsecs: 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(r: &inc->i_refcount, n: 1);
62 INIT_LIST_HEAD(list: &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(secs: 0, nsecs: 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(r: &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(r: &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, addr: &rm->m_flags);
155 }
156 spin_unlock_irqrestore(lock: &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: &pos, buf: &buffer, buflen: &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), force: 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: &pos, buf: &buffer, buflen: &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, peer_gen_num: 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(a1: &conn->c_laddr, a2: &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, dport: 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(hdr: &inc->i_hdr, conn: cp->cp_conn);
349 rds_start_mprds(conn: 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(hdr: &inc->i_hdr, conn: cp->cp_conn);
357 /* if this is a handshake pong, start multipath if necessary */
358 rds_start_mprds(conn: cp->cp_conn);
359 wake_up(&cp->cp_conn->c_hs_waitq);
360 goto out;
361 }
362
363 rs = rds_find_bound(addr: daddr, port: inc->i_hdr.h_dport, scope_id: 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, flag: 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, map: inc->i_conn->c_lcong,
381 be32_to_cpu(inc->i_hdr.h_len),
382 port: inc->i_hdr.h_dport);
383 if (sock_flag(sk, flag: 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(new: &inc->i_item, head: &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(head: &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: *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
429 write_lock_irqsave(&rs->rs_recv_lock, flags);
430 if (!list_empty(head: &inc->i_item)) {
431 ret = 1;
432 if (drop) {
433 /* XXX make sure this i_conn is reliable */
434 rds_recv_rcvbuf_delta(rs, sk, map: inc->i_conn->c_lcong,
435 delta: -be32_to_cpu(inc->i_hdr.h_len),
436 port: inc->i_hdr.h_dport);
437 list_del_init(entry: &inc->i_item);
438 rds_inc_put(inc);
439 }
440 }
441 write_unlock_irqrestore(&rs->rs_recv_lock, flags);
442
443 rdsdebug("inc %p rs %p still %d dropped %d\n", inc, rs, ret, drop);
444 return ret;
445}
446
447/*
448 * Pull errors off the error queue.
449 * If msghdr is NULL, we will just purge the error queue.
450 */
451int rds_notify_queue_get(struct rds_sock *rs, struct msghdr *msghdr)
452{
453 struct rds_notifier *notifier;
454 struct rds_rdma_notify cmsg;
455 unsigned int count = 0, max_messages = ~0U;
456 unsigned long flags;
457 LIST_HEAD(copy);
458 int err = 0;
459
460 memset(&cmsg, 0, sizeof(cmsg)); /* fill holes with zero */
461
462 /* put_cmsg copies to user space and thus may sleep. We can't do this
463 * with rs_lock held, so first grab as many notifications as we can stuff
464 * in the user provided cmsg buffer. We don't try to copy more, to avoid
465 * losing notifications - except when the buffer is so small that it wouldn't
466 * even hold a single notification. Then we give him as much of this single
467 * msg as we can squeeze in, and set MSG_CTRUNC.
468 */
469 if (msghdr) {
470 max_messages = msghdr->msg_controllen / CMSG_SPACE(sizeof(cmsg));
471 if (!max_messages)
472 max_messages = 1;
473 }
474
475 spin_lock_irqsave(&rs->rs_lock, flags);
476 while (!list_empty(head: &rs->rs_notify_queue) && count < max_messages) {
477 notifier = list_entry(rs->rs_notify_queue.next,
478 struct rds_notifier, n_list);
479 list_move(list: &notifier->n_list, head: &copy);
480 count++;
481 }
482 spin_unlock_irqrestore(lock: &rs->rs_lock, flags);
483
484 if (!count)
485 return 0;
486
487 while (!list_empty(head: &copy)) {
488 notifier = list_entry(copy.next, struct rds_notifier, n_list);
489
490 if (msghdr) {
491 cmsg.user_token = notifier->n_user_token;
492 cmsg.status = notifier->n_status;
493
494 err = put_cmsg(msghdr, SOL_RDS, RDS_CMSG_RDMA_STATUS,
495 len: sizeof(cmsg), data: &cmsg);
496 if (err)
497 break;
498 }
499
500 list_del_init(entry: &notifier->n_list);
501 kfree(objp: notifier);
502 }
503
504 /* If we bailed out because of an error in put_cmsg,
505 * we may be left with one or more notifications that we
506 * didn't process. Return them to the head of the list. */
507 if (!list_empty(head: &copy)) {
508 spin_lock_irqsave(&rs->rs_lock, flags);
509 list_splice(list: &copy, head: &rs->rs_notify_queue);
510 spin_unlock_irqrestore(lock: &rs->rs_lock, flags);
511 }
512
513 return err;
514}
515
516/*
517 * Queue a congestion notification
518 */
519static int rds_notify_cong(struct rds_sock *rs, struct msghdr *msghdr)
520{
521 uint64_t notify = rs->rs_cong_notify;
522 unsigned long flags;
523 int err;
524
525 err = put_cmsg(msghdr, SOL_RDS, RDS_CMSG_CONG_UPDATE,
526 len: sizeof(notify), data: &notify);
527 if (err)
528 return err;
529
530 spin_lock_irqsave(&rs->rs_lock, flags);
531 rs->rs_cong_notify &= ~notify;
532 spin_unlock_irqrestore(lock: &rs->rs_lock, flags);
533
534 return 0;
535}
536
537/*
538 * Receive any control messages.
539 */
540static int rds_cmsg_recv(struct rds_incoming *inc, struct msghdr *msg,
541 struct rds_sock *rs)
542{
543 int ret = 0;
544
545 if (inc->i_usercopy.rdma_cookie) {
546 ret = put_cmsg(msg, SOL_RDS, RDS_CMSG_RDMA_DEST,
547 len: sizeof(inc->i_usercopy.rdma_cookie),
548 data: &inc->i_usercopy.rdma_cookie);
549 if (ret)
550 goto out;
551 }
552
553 if ((inc->i_usercopy.rx_tstamp != 0) &&
554 sock_flag(sk: rds_rs_to_sk(rs), flag: SOCK_RCVTSTAMP)) {
555 struct __kernel_old_timeval tv =
556 ns_to_kernel_old_timeval(nsec: inc->i_usercopy.rx_tstamp);
557
558 if (!sock_flag(sk: rds_rs_to_sk(rs), flag: SOCK_TSTAMP_NEW)) {
559 ret = put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_OLD,
560 len: sizeof(tv), data: &tv);
561 } else {
562 struct __kernel_sock_timeval sk_tv;
563
564 sk_tv.tv_sec = tv.tv_sec;
565 sk_tv.tv_usec = tv.tv_usec;
566
567 ret = put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_NEW,
568 len: sizeof(sk_tv), data: &sk_tv);
569 }
570
571 if (ret)
572 goto out;
573 }
574
575 if (rs->rs_rx_traces) {
576 struct rds_cmsg_rx_trace t;
577 int i, j;
578
579 memset(&t, 0, sizeof(t));
580 inc->i_rx_lat_trace[RDS_MSG_RX_CMSG] = local_clock();
581 t.rx_traces = rs->rs_rx_traces;
582 for (i = 0; i < rs->rs_rx_traces; i++) {
583 j = rs->rs_rx_trace[i];
584 t.rx_trace_pos[i] = j;
585 t.rx_trace[i] = inc->i_rx_lat_trace[j + 1] -
586 inc->i_rx_lat_trace[j];
587 }
588
589 ret = put_cmsg(msg, SOL_RDS, RDS_CMSG_RXPATH_LATENCY,
590 len: sizeof(t), data: &t);
591 if (ret)
592 goto out;
593 }
594
595out:
596 return ret;
597}
598
599static bool rds_recvmsg_zcookie(struct rds_sock *rs, struct msghdr *msg)
600{
601 struct rds_msg_zcopy_queue *q = &rs->rs_zcookie_queue;
602 struct rds_msg_zcopy_info *info = NULL;
603 struct rds_zcopy_cookies *done;
604 unsigned long flags;
605
606 if (!msg->msg_control)
607 return false;
608
609 if (!sock_flag(sk: rds_rs_to_sk(rs), flag: SOCK_ZEROCOPY) ||
610 msg->msg_controllen < CMSG_SPACE(sizeof(*done)))
611 return false;
612
613 spin_lock_irqsave(&q->lock, flags);
614 if (!list_empty(head: &q->zcookie_head)) {
615 info = list_entry(q->zcookie_head.next,
616 struct rds_msg_zcopy_info, rs_zcookie_next);
617 list_del(entry: &info->rs_zcookie_next);
618 }
619 spin_unlock_irqrestore(lock: &q->lock, flags);
620 if (!info)
621 return false;
622 done = &info->zcookies;
623 if (put_cmsg(msg, SOL_RDS, RDS_CMSG_ZCOPY_COMPLETION, len: sizeof(*done),
624 data: done)) {
625 spin_lock_irqsave(&q->lock, flags);
626 list_add(new: &info->rs_zcookie_next, head: &q->zcookie_head);
627 spin_unlock_irqrestore(lock: &q->lock, flags);
628 return false;
629 }
630 kfree(objp: info);
631 return true;
632}
633
634int rds_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
635 int msg_flags)
636{
637 struct sock *sk = sock->sk;
638 struct rds_sock *rs = rds_sk_to_rs(sk);
639 long timeo;
640 int ret = 0, nonblock = msg_flags & MSG_DONTWAIT;
641 DECLARE_SOCKADDR(struct sockaddr_in6 *, sin6, msg->msg_name);
642 DECLARE_SOCKADDR(struct sockaddr_in *, sin, msg->msg_name);
643 struct rds_incoming *inc = NULL;
644
645 /* udp_recvmsg()->sock_recvtimeo() gets away without locking too.. */
646 timeo = sock_rcvtimeo(sk, noblock: nonblock);
647
648 rdsdebug("size %zu flags 0x%x timeo %ld\n", size, msg_flags, timeo);
649
650 if (msg_flags & MSG_OOB)
651 goto out;
652 if (msg_flags & MSG_ERRQUEUE)
653 return sock_recv_errqueue(sk, msg, len: size, SOL_IP, IP_RECVERR);
654
655 while (1) {
656 /* If there are pending notifications, do those - and nothing else */
657 if (!list_empty(head: &rs->rs_notify_queue)) {
658 ret = rds_notify_queue_get(rs, msghdr: msg);
659 break;
660 }
661
662 if (rs->rs_cong_notify) {
663 ret = rds_notify_cong(rs, msghdr: msg);
664 break;
665 }
666
667 if (!rds_next_incoming(rs, inc: &inc)) {
668 if (nonblock) {
669 bool reaped = rds_recvmsg_zcookie(rs, msg);
670
671 ret = reaped ? 0 : -EAGAIN;
672 break;
673 }
674
675 timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
676 (!list_empty(&rs->rs_notify_queue) ||
677 rs->rs_cong_notify ||
678 rds_next_incoming(rs, &inc)), timeo);
679 rdsdebug("recvmsg woke inc %p timeo %ld\n", inc,
680 timeo);
681 if (timeo > 0 || timeo == MAX_SCHEDULE_TIMEOUT)
682 continue;
683
684 ret = timeo;
685 if (ret == 0)
686 ret = -ETIMEDOUT;
687 break;
688 }
689
690 rdsdebug("copying inc %p from %pI6c:%u to user\n", inc,
691 &inc->i_conn->c_faddr,
692 ntohs(inc->i_hdr.h_sport));
693 ret = inc->i_conn->c_trans->inc_copy_to_user(inc, &msg->msg_iter);
694 if (ret < 0)
695 break;
696
697 /*
698 * if the message we just copied isn't at the head of the
699 * recv queue then someone else raced us to return it, try
700 * to get the next message.
701 */
702 if (!rds_still_queued(rs, inc, drop: !(msg_flags & MSG_PEEK))) {
703 rds_inc_put(inc);
704 inc = NULL;
705 rds_stats_inc(s_recv_deliver_raced);
706 iov_iter_revert(i: &msg->msg_iter, bytes: ret);
707 continue;
708 }
709
710 if (ret < be32_to_cpu(inc->i_hdr.h_len)) {
711 if (msg_flags & MSG_TRUNC)
712 ret = be32_to_cpu(inc->i_hdr.h_len);
713 msg->msg_flags |= MSG_TRUNC;
714 }
715
716 if (rds_cmsg_recv(inc, msg, rs)) {
717 ret = -EFAULT;
718 break;
719 }
720 rds_recvmsg_zcookie(rs, msg);
721
722 rds_stats_inc(s_recv_delivered);
723
724 if (msg->msg_name) {
725 if (ipv6_addr_v4mapped(a: &inc->i_saddr)) {
726 sin->sin_family = AF_INET;
727 sin->sin_port = inc->i_hdr.h_sport;
728 sin->sin_addr.s_addr =
729 inc->i_saddr.s6_addr32[3];
730 memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
731 msg->msg_namelen = sizeof(*sin);
732 } else {
733 sin6->sin6_family = AF_INET6;
734 sin6->sin6_port = inc->i_hdr.h_sport;
735 sin6->sin6_addr = inc->i_saddr;
736 sin6->sin6_flowinfo = 0;
737 sin6->sin6_scope_id = rs->rs_bound_scope_id;
738 msg->msg_namelen = sizeof(*sin6);
739 }
740 }
741 break;
742 }
743
744 if (inc)
745 rds_inc_put(inc);
746
747out:
748 return ret;
749}
750
751/*
752 * The socket is being shut down and we're asked to drop messages that were
753 * queued for recvmsg. The caller has unbound the socket so the receive path
754 * won't queue any more incoming fragments or messages on the socket.
755 */
756void rds_clear_recv_queue(struct rds_sock *rs)
757{
758 struct sock *sk = rds_rs_to_sk(rs);
759 struct rds_incoming *inc, *tmp;
760 unsigned long flags;
761
762 write_lock_irqsave(&rs->rs_recv_lock, flags);
763 list_for_each_entry_safe(inc, tmp, &rs->rs_recv_queue, i_item) {
764 rds_recv_rcvbuf_delta(rs, sk, map: inc->i_conn->c_lcong,
765 delta: -be32_to_cpu(inc->i_hdr.h_len),
766 port: inc->i_hdr.h_dport);
767 list_del_init(entry: &inc->i_item);
768 rds_inc_put(inc);
769 }
770 write_unlock_irqrestore(&rs->rs_recv_lock, flags);
771}
772
773/*
774 * inc->i_saddr isn't used here because it is only set in the receive
775 * path.
776 */
777void rds_inc_info_copy(struct rds_incoming *inc,
778 struct rds_info_iterator *iter,
779 __be32 saddr, __be32 daddr, int flip)
780{
781 struct rds_info_message minfo;
782
783 minfo.seq = be64_to_cpu(inc->i_hdr.h_sequence);
784 minfo.len = be32_to_cpu(inc->i_hdr.h_len);
785 minfo.tos = inc->i_conn->c_tos;
786
787 if (flip) {
788 minfo.laddr = daddr;
789 minfo.faddr = saddr;
790 minfo.lport = inc->i_hdr.h_dport;
791 minfo.fport = inc->i_hdr.h_sport;
792 } else {
793 minfo.laddr = saddr;
794 minfo.faddr = daddr;
795 minfo.lport = inc->i_hdr.h_sport;
796 minfo.fport = inc->i_hdr.h_dport;
797 }
798
799 minfo.flags = 0;
800
801 rds_info_copy(iter, data: &minfo, bytes: sizeof(minfo));
802}
803
804#if IS_ENABLED(CONFIG_IPV6)
805void rds6_inc_info_copy(struct rds_incoming *inc,
806 struct rds_info_iterator *iter,
807 struct in6_addr *saddr, struct in6_addr *daddr,
808 int flip)
809{
810 struct rds6_info_message minfo6;
811
812 minfo6.seq = be64_to_cpu(inc->i_hdr.h_sequence);
813 minfo6.len = be32_to_cpu(inc->i_hdr.h_len);
814 minfo6.tos = inc->i_conn->c_tos;
815
816 if (flip) {
817 minfo6.laddr = *daddr;
818 minfo6.faddr = *saddr;
819 minfo6.lport = inc->i_hdr.h_dport;
820 minfo6.fport = inc->i_hdr.h_sport;
821 } else {
822 minfo6.laddr = *saddr;
823 minfo6.faddr = *daddr;
824 minfo6.lport = inc->i_hdr.h_sport;
825 minfo6.fport = inc->i_hdr.h_dport;
826 }
827
828 minfo6.flags = 0;
829
830 rds_info_copy(iter, data: &minfo6, bytes: sizeof(minfo6));
831}
832#endif
833

source code of linux/net/rds/recv.c