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