1 /*
2 * Copyright (c) 2006, 2018 Oracle and/or its affiliates. All rights reserved.
3 *
4 * This software is available to you under a choice of one of two
5 * licenses. You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the
8 * OpenIB.org BSD license below:
9 *
10 * Redistribution and use in source and binary forms, with or
11 * without modification, are permitted provided that the following
12 * conditions are met:
13 *
14 * - Redistributions of source code must retain the above
15 * copyright notice, this list of conditions and the following
16 * disclaimer.
17 *
18 * - Redistributions in binary form must reproduce the above
19 * copyright notice, this list of conditions and the following
20 * disclaimer in the documentation and/or other materials
21 * provided with the distribution.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30 * SOFTWARE.
31 *
32 */
33 #include <linux/kernel.h>
34 #include <linux/slab.h>
35 #include <linux/in.h>
36 #include <linux/module.h>
37 #include <net/tcp.h>
38 #include <net/net_namespace.h>
39 #include <net/netns/generic.h>
40 #include <net/addrconf.h>
41
42 #include "rds.h"
43 #include "tcp.h"
44
45 /* only for info exporting */
46 static DEFINE_SPINLOCK(rds_tcp_tc_list_lock);
47 static LIST_HEAD(rds_tcp_tc_list);
48
49 /* rds_tcp_tc_count counts only IPv4 connections.
50 * rds6_tcp_tc_count counts both IPv4 and IPv6 connections.
51 */
52 static unsigned int rds_tcp_tc_count;
53 #if IS_ENABLED(CONFIG_IPV6)
54 static unsigned int rds6_tcp_tc_count;
55 #endif
56
57 /* Track rds_tcp_connection structs so they can be cleaned up */
58 static DEFINE_SPINLOCK(rds_tcp_conn_lock);
59 static LIST_HEAD(rds_tcp_conn_list);
60 static atomic_t rds_tcp_unloading = ATOMIC_INIT(0);
61
62 static struct kmem_cache *rds_tcp_conn_slab;
63
64 static int rds_tcp_skbuf_handler(const struct ctl_table *ctl, int write,
65 void *buffer, size_t *lenp, loff_t *fpos);
66
67 static int rds_tcp_min_sndbuf = SOCK_MIN_SNDBUF;
68 static int rds_tcp_min_rcvbuf = SOCK_MIN_RCVBUF;
69
70 static struct ctl_table rds_tcp_sysctl_table[] = {
71 #define RDS_TCP_SNDBUF 0
72 {
73 .procname = "rds_tcp_sndbuf",
74 /* data is per-net pointer */
75 .maxlen = sizeof(int),
76 .mode = 0644,
77 .proc_handler = rds_tcp_skbuf_handler,
78 .extra1 = &rds_tcp_min_sndbuf,
79 },
80 #define RDS_TCP_RCVBUF 1
81 {
82 .procname = "rds_tcp_rcvbuf",
83 /* data is per-net pointer */
84 .maxlen = sizeof(int),
85 .mode = 0644,
86 .proc_handler = rds_tcp_skbuf_handler,
87 .extra1 = &rds_tcp_min_rcvbuf,
88 },
89 };
90
rds_tcp_write_seq(struct rds_tcp_connection * tc)91 u32 rds_tcp_write_seq(struct rds_tcp_connection *tc)
92 {
93 /* seq# of the last byte of data in tcp send buffer */
94 return tcp_sk(tc->t_sock->sk)->write_seq;
95 }
96
rds_tcp_snd_una(struct rds_tcp_connection * tc)97 u32 rds_tcp_snd_una(struct rds_tcp_connection *tc)
98 {
99 return tcp_sk(tc->t_sock->sk)->snd_una;
100 }
101
rds_tcp_restore_callbacks(struct socket * sock,struct rds_tcp_connection * tc)102 void rds_tcp_restore_callbacks(struct socket *sock,
103 struct rds_tcp_connection *tc)
104 {
105 rdsdebug("restoring sock %p callbacks from tc %p\n", sock, tc);
106 write_lock_bh(&sock->sk->sk_callback_lock);
107
108 /* done under the callback_lock to serialize with write_space */
109 spin_lock(&rds_tcp_tc_list_lock);
110 list_del_init(&tc->t_list_item);
111 #if IS_ENABLED(CONFIG_IPV6)
112 rds6_tcp_tc_count--;
113 #endif
114 if (!tc->t_cpath->cp_conn->c_isv6)
115 rds_tcp_tc_count--;
116 spin_unlock(&rds_tcp_tc_list_lock);
117
118 tc->t_sock = NULL;
119
120 sock->sk->sk_write_space = tc->t_orig_write_space;
121 sock->sk->sk_data_ready = tc->t_orig_data_ready;
122 sock->sk->sk_state_change = tc->t_orig_state_change;
123 sock->sk->sk_user_data = NULL;
124
125 write_unlock_bh(&sock->sk->sk_callback_lock);
126 }
127
128 /*
129 * rds_tcp_reset_callbacks() switches the to the new sock and
130 * returns the existing tc->t_sock.
131 *
132 * The only functions that set tc->t_sock are rds_tcp_set_callbacks
133 * and rds_tcp_reset_callbacks. Send and receive trust that
134 * it is set. The absence of RDS_CONN_UP bit protects those paths
135 * from being called while it isn't set.
136 */
rds_tcp_reset_callbacks(struct socket * sock,struct rds_conn_path * cp)137 void rds_tcp_reset_callbacks(struct socket *sock,
138 struct rds_conn_path *cp)
139 {
140 struct rds_tcp_connection *tc = cp->cp_transport_data;
141 struct socket *osock = tc->t_sock;
142
143 if (!osock)
144 goto newsock;
145
146 /* Need to resolve a duelling SYN between peers.
147 * We have an outstanding SYN to this peer, which may
148 * potentially have transitioned to the RDS_CONN_UP state,
149 * so we must quiesce any send threads before resetting
150 * cp_transport_data. We quiesce these threads by setting
151 * cp_state to something other than RDS_CONN_UP, and then
152 * waiting for any existing threads in rds_send_xmit to
153 * complete release_in_xmit(). (Subsequent threads entering
154 * rds_send_xmit() will bail on !rds_conn_up().
155 *
156 * However an incoming syn-ack at this point would end up
157 * marking the conn as RDS_CONN_UP, and would again permit
158 * rds_send_xmi() threads through, so ideally we would
159 * synchronize on RDS_CONN_UP after lock_sock(), but cannot
160 * do that: waiting on !RDS_IN_XMIT after lock_sock() may
161 * end up deadlocking with tcp_sendmsg(), and the RDS_IN_XMIT
162 * would not get set. As a result, we set c_state to
163 * RDS_CONN_RESETTTING, to ensure that rds_tcp_state_change
164 * cannot mark rds_conn_path_up() in the window before lock_sock()
165 */
166 atomic_set(&cp->cp_state, RDS_CONN_RESETTING);
167 wait_event(cp->cp_waitq, !test_bit(RDS_IN_XMIT, &cp->cp_flags));
168 /* reset receive side state for rds_tcp_data_recv() for osock */
169 cancel_delayed_work_sync(&cp->cp_send_w);
170 cancel_delayed_work_sync(&cp->cp_recv_w);
171 lock_sock(osock->sk);
172 if (tc->t_tinc) {
173 rds_inc_put(&tc->t_tinc->ti_inc);
174 tc->t_tinc = NULL;
175 }
176 tc->t_tinc_hdr_rem = sizeof(struct rds_header);
177 tc->t_tinc_data_rem = 0;
178 rds_tcp_restore_callbacks(osock, tc);
179 release_sock(osock->sk);
180 sock_release(osock);
181 newsock:
182 rds_send_path_reset(cp);
183 lock_sock(sock->sk);
184 rds_tcp_set_callbacks(sock, cp);
185 release_sock(sock->sk);
186 }
187
188 /* Add tc to rds_tcp_tc_list and set tc->t_sock. See comments
189 * above rds_tcp_reset_callbacks for notes about synchronization
190 * with data path
191 */
rds_tcp_set_callbacks(struct socket * sock,struct rds_conn_path * cp)192 void rds_tcp_set_callbacks(struct socket *sock, struct rds_conn_path *cp)
193 {
194 struct rds_tcp_connection *tc = cp->cp_transport_data;
195
196 rdsdebug("setting sock %p callbacks to tc %p\n", sock, tc);
197 write_lock_bh(&sock->sk->sk_callback_lock);
198
199 /* done under the callback_lock to serialize with write_space */
200 spin_lock(&rds_tcp_tc_list_lock);
201 list_add_tail(&tc->t_list_item, &rds_tcp_tc_list);
202 #if IS_ENABLED(CONFIG_IPV6)
203 rds6_tcp_tc_count++;
204 #endif
205 if (!tc->t_cpath->cp_conn->c_isv6)
206 rds_tcp_tc_count++;
207 spin_unlock(&rds_tcp_tc_list_lock);
208
209 /* accepted sockets need our listen data ready undone */
210 if (sock->sk->sk_data_ready == rds_tcp_listen_data_ready)
211 sock->sk->sk_data_ready = sock->sk->sk_user_data;
212
213 tc->t_sock = sock;
214 tc->t_cpath = cp;
215 tc->t_orig_data_ready = sock->sk->sk_data_ready;
216 tc->t_orig_write_space = sock->sk->sk_write_space;
217 tc->t_orig_state_change = sock->sk->sk_state_change;
218
219 sock->sk->sk_user_data = cp;
220 sock->sk->sk_data_ready = rds_tcp_data_ready;
221 sock->sk->sk_write_space = rds_tcp_write_space;
222 sock->sk->sk_state_change = rds_tcp_state_change;
223
224 write_unlock_bh(&sock->sk->sk_callback_lock);
225 }
226
227 /* Handle RDS_INFO_TCP_SOCKETS socket option. It only returns IPv4
228 * connections for backward compatibility.
229 */
rds_tcp_tc_info(struct socket * rds_sock,unsigned int len,struct rds_info_iterator * iter,struct rds_info_lengths * lens)230 static void rds_tcp_tc_info(struct socket *rds_sock, unsigned int len,
231 struct rds_info_iterator *iter,
232 struct rds_info_lengths *lens)
233 {
234 struct rds_info_tcp_socket tsinfo;
235 struct rds_tcp_connection *tc;
236 unsigned long flags;
237
238 spin_lock_irqsave(&rds_tcp_tc_list_lock, flags);
239
240 if (len / sizeof(tsinfo) < rds_tcp_tc_count)
241 goto out;
242
243 list_for_each_entry(tc, &rds_tcp_tc_list, t_list_item) {
244 struct inet_sock *inet = inet_sk(tc->t_sock->sk);
245
246 if (tc->t_cpath->cp_conn->c_isv6)
247 continue;
248
249 tsinfo.local_addr = inet->inet_saddr;
250 tsinfo.local_port = inet->inet_sport;
251 tsinfo.peer_addr = inet->inet_daddr;
252 tsinfo.peer_port = inet->inet_dport;
253
254 tsinfo.hdr_rem = tc->t_tinc_hdr_rem;
255 tsinfo.data_rem = tc->t_tinc_data_rem;
256 tsinfo.last_sent_nxt = tc->t_last_sent_nxt;
257 tsinfo.last_expected_una = tc->t_last_expected_una;
258 tsinfo.last_seen_una = tc->t_last_seen_una;
259 tsinfo.tos = tc->t_cpath->cp_conn->c_tos;
260
261 rds_info_copy(iter, &tsinfo, sizeof(tsinfo));
262 }
263
264 out:
265 lens->nr = rds_tcp_tc_count;
266 lens->each = sizeof(tsinfo);
267
268 spin_unlock_irqrestore(&rds_tcp_tc_list_lock, flags);
269 }
270
271 #if IS_ENABLED(CONFIG_IPV6)
272 /* Handle RDS6_INFO_TCP_SOCKETS socket option. It returns both IPv4 and
273 * IPv6 connections. IPv4 connection address is returned in an IPv4 mapped
274 * address.
275 */
rds6_tcp_tc_info(struct socket * sock,unsigned int len,struct rds_info_iterator * iter,struct rds_info_lengths * lens)276 static void rds6_tcp_tc_info(struct socket *sock, unsigned int len,
277 struct rds_info_iterator *iter,
278 struct rds_info_lengths *lens)
279 {
280 struct rds6_info_tcp_socket tsinfo6;
281 struct rds_tcp_connection *tc;
282 unsigned long flags;
283
284 spin_lock_irqsave(&rds_tcp_tc_list_lock, flags);
285
286 if (len / sizeof(tsinfo6) < rds6_tcp_tc_count)
287 goto out;
288
289 list_for_each_entry(tc, &rds_tcp_tc_list, t_list_item) {
290 struct sock *sk = tc->t_sock->sk;
291 struct inet_sock *inet = inet_sk(sk);
292
293 tsinfo6.local_addr = sk->sk_v6_rcv_saddr;
294 tsinfo6.local_port = inet->inet_sport;
295 tsinfo6.peer_addr = sk->sk_v6_daddr;
296 tsinfo6.peer_port = inet->inet_dport;
297
298 tsinfo6.hdr_rem = tc->t_tinc_hdr_rem;
299 tsinfo6.data_rem = tc->t_tinc_data_rem;
300 tsinfo6.last_sent_nxt = tc->t_last_sent_nxt;
301 tsinfo6.last_expected_una = tc->t_last_expected_una;
302 tsinfo6.last_seen_una = tc->t_last_seen_una;
303
304 rds_info_copy(iter, &tsinfo6, sizeof(tsinfo6));
305 }
306
307 out:
308 lens->nr = rds6_tcp_tc_count;
309 lens->each = sizeof(tsinfo6);
310
311 spin_unlock_irqrestore(&rds_tcp_tc_list_lock, flags);
312 }
313 #endif
314
rds_tcp_laddr_check(struct net * net,const struct in6_addr * addr,__u32 scope_id)315 int rds_tcp_laddr_check(struct net *net, const struct in6_addr *addr,
316 __u32 scope_id)
317 {
318 struct net_device *dev = NULL;
319 #if IS_ENABLED(CONFIG_IPV6)
320 int ret;
321 #endif
322
323 if (ipv6_addr_v4mapped(addr)) {
324 if (inet_addr_type(net, addr->s6_addr32[3]) == RTN_LOCAL)
325 return 0;
326 return -EADDRNOTAVAIL;
327 }
328
329 /* If the scope_id is specified, check only those addresses
330 * hosted on the specified interface.
331 */
332 if (scope_id != 0) {
333 rcu_read_lock();
334 dev = dev_get_by_index_rcu(net, scope_id);
335 /* scope_id is not valid... */
336 if (!dev) {
337 rcu_read_unlock();
338 return -EADDRNOTAVAIL;
339 }
340 rcu_read_unlock();
341 }
342 #if IS_ENABLED(CONFIG_IPV6)
343 ret = ipv6_chk_addr(net, addr, dev, 0);
344 if (ret)
345 return 0;
346 #endif
347 return -EADDRNOTAVAIL;
348 }
349
rds_tcp_conn_free(void * arg)350 static void rds_tcp_conn_free(void *arg)
351 {
352 struct rds_tcp_connection *tc = arg;
353 unsigned long flags;
354
355 rdsdebug("freeing tc %p\n", tc);
356
357 spin_lock_irqsave(&rds_tcp_conn_lock, flags);
358 if (!tc->t_tcp_node_detached)
359 list_del(&tc->t_tcp_node);
360 spin_unlock_irqrestore(&rds_tcp_conn_lock, flags);
361
362 kmem_cache_free(rds_tcp_conn_slab, tc);
363 }
364
rds_tcp_conn_alloc(struct rds_connection * conn,gfp_t gfp)365 static int rds_tcp_conn_alloc(struct rds_connection *conn, gfp_t gfp)
366 {
367 struct rds_tcp_connection *tc;
368 int i, j;
369 int ret = 0;
370
371 for (i = 0; i < RDS_MPATH_WORKERS; i++) {
372 tc = kmem_cache_alloc(rds_tcp_conn_slab, gfp);
373 if (!tc) {
374 ret = -ENOMEM;
375 goto fail;
376 }
377 mutex_init(&tc->t_conn_path_lock);
378 tc->t_sock = NULL;
379 tc->t_tinc = NULL;
380 tc->t_tinc_hdr_rem = sizeof(struct rds_header);
381 tc->t_tinc_data_rem = 0;
382
383 conn->c_path[i].cp_transport_data = tc;
384 tc->t_cpath = &conn->c_path[i];
385 tc->t_tcp_node_detached = true;
386
387 rdsdebug("rds_conn_path [%d] tc %p\n", i,
388 conn->c_path[i].cp_transport_data);
389 }
390 spin_lock_irq(&rds_tcp_conn_lock);
391 for (i = 0; i < RDS_MPATH_WORKERS; i++) {
392 tc = conn->c_path[i].cp_transport_data;
393 tc->t_tcp_node_detached = false;
394 list_add_tail(&tc->t_tcp_node, &rds_tcp_conn_list);
395 }
396 spin_unlock_irq(&rds_tcp_conn_lock);
397 fail:
398 if (ret) {
399 for (j = 0; j < i; j++)
400 rds_tcp_conn_free(conn->c_path[j].cp_transport_data);
401 }
402 return ret;
403 }
404
list_has_conn(struct list_head * list,struct rds_connection * conn)405 static bool list_has_conn(struct list_head *list, struct rds_connection *conn)
406 {
407 struct rds_tcp_connection *tc, *_tc;
408
409 list_for_each_entry_safe(tc, _tc, list, t_tcp_node) {
410 if (tc->t_cpath->cp_conn == conn)
411 return true;
412 }
413 return false;
414 }
415
rds_tcp_set_unloading(void)416 static void rds_tcp_set_unloading(void)
417 {
418 atomic_set(&rds_tcp_unloading, 1);
419 }
420
rds_tcp_is_unloading(struct rds_connection * conn)421 static bool rds_tcp_is_unloading(struct rds_connection *conn)
422 {
423 return atomic_read(&rds_tcp_unloading) != 0;
424 }
425
rds_tcp_destroy_conns(void)426 static void rds_tcp_destroy_conns(void)
427 {
428 struct rds_tcp_connection *tc, *_tc;
429 LIST_HEAD(tmp_list);
430
431 /* avoid calling conn_destroy with irqs off */
432 spin_lock_irq(&rds_tcp_conn_lock);
433 list_for_each_entry_safe(tc, _tc, &rds_tcp_conn_list, t_tcp_node) {
434 if (!list_has_conn(&tmp_list, tc->t_cpath->cp_conn))
435 list_move_tail(&tc->t_tcp_node, &tmp_list);
436 }
437 spin_unlock_irq(&rds_tcp_conn_lock);
438
439 list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node)
440 rds_conn_destroy(tc->t_cpath->cp_conn);
441 }
442
443 static void rds_tcp_exit(void);
444
rds_tcp_get_tos_map(u8 tos)445 static u8 rds_tcp_get_tos_map(u8 tos)
446 {
447 /* all user tos mapped to default 0 for TCP transport */
448 return 0;
449 }
450
451 struct rds_transport rds_tcp_transport = {
452 .laddr_check = rds_tcp_laddr_check,
453 .xmit_path_prepare = rds_tcp_xmit_path_prepare,
454 .xmit_path_complete = rds_tcp_xmit_path_complete,
455 .xmit = rds_tcp_xmit,
456 .recv_path = rds_tcp_recv_path,
457 .conn_alloc = rds_tcp_conn_alloc,
458 .conn_free = rds_tcp_conn_free,
459 .conn_path_connect = rds_tcp_conn_path_connect,
460 .conn_path_shutdown = rds_tcp_conn_path_shutdown,
461 .inc_copy_to_user = rds_tcp_inc_copy_to_user,
462 .inc_free = rds_tcp_inc_free,
463 .stats_info_copy = rds_tcp_stats_info_copy,
464 .exit = rds_tcp_exit,
465 .get_tos_map = rds_tcp_get_tos_map,
466 .t_owner = THIS_MODULE,
467 .t_name = "tcp",
468 .t_type = RDS_TRANS_TCP,
469 .t_prefer_loopback = 1,
470 .t_mp_capable = 1,
471 .t_unloading = rds_tcp_is_unloading,
472 };
473
474 static unsigned int rds_tcp_netid;
475
476 /* per-network namespace private data for this module */
477 struct rds_tcp_net {
478 struct socket *rds_tcp_listen_sock;
479 struct work_struct rds_tcp_accept_w;
480 struct ctl_table_header *rds_tcp_sysctl;
481 struct ctl_table *ctl_table;
482 int sndbuf_size;
483 int rcvbuf_size;
484 };
485
486 /* All module specific customizations to the RDS-TCP socket should be done in
487 * rds_tcp_tune() and applied after socket creation.
488 */
rds_tcp_tune(struct socket * sock)489 bool rds_tcp_tune(struct socket *sock)
490 {
491 struct sock *sk = sock->sk;
492 struct net *net = sock_net(sk);
493 struct rds_tcp_net *rtn;
494
495 tcp_sock_set_nodelay(sock->sk);
496 lock_sock(sk);
497 /* TCP timer functions might access net namespace even after
498 * a process which created this net namespace terminated.
499 */
500 if (!sk->sk_net_refcnt) {
501 if (!maybe_get_net(net)) {
502 release_sock(sk);
503 return false;
504 }
505 /* Update ns_tracker to current stack trace and refcounted tracker */
506 __netns_tracker_free(net, &sk->ns_tracker, false);
507
508 sk->sk_net_refcnt = 1;
509 netns_tracker_alloc(net, &sk->ns_tracker, GFP_KERNEL);
510 sock_inuse_add(net, 1);
511 }
512 rtn = net_generic(net, rds_tcp_netid);
513 if (rtn->sndbuf_size > 0) {
514 sk->sk_sndbuf = rtn->sndbuf_size;
515 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
516 }
517 if (rtn->rcvbuf_size > 0) {
518 sk->sk_rcvbuf = rtn->rcvbuf_size;
519 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
520 }
521 release_sock(sk);
522 return true;
523 }
524
rds_tcp_accept_worker(struct work_struct * work)525 static void rds_tcp_accept_worker(struct work_struct *work)
526 {
527 struct rds_tcp_net *rtn = container_of(work,
528 struct rds_tcp_net,
529 rds_tcp_accept_w);
530
531 while (rds_tcp_accept_one(rtn->rds_tcp_listen_sock) == 0)
532 cond_resched();
533 }
534
rds_tcp_accept_work(struct sock * sk)535 void rds_tcp_accept_work(struct sock *sk)
536 {
537 struct net *net = sock_net(sk);
538 struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);
539
540 queue_work(rds_wq, &rtn->rds_tcp_accept_w);
541 }
542
rds_tcp_init_net(struct net * net)543 static __net_init int rds_tcp_init_net(struct net *net)
544 {
545 struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);
546 struct ctl_table *tbl;
547 int err = 0;
548
549 memset(rtn, 0, sizeof(*rtn));
550
551 /* {snd, rcv}buf_size default to 0, which implies we let the
552 * stack pick the value, and permit auto-tuning of buffer size.
553 */
554 if (net == &init_net) {
555 tbl = rds_tcp_sysctl_table;
556 } else {
557 tbl = kmemdup(rds_tcp_sysctl_table,
558 sizeof(rds_tcp_sysctl_table), GFP_KERNEL);
559 if (!tbl) {
560 pr_warn("could not set allocate sysctl table\n");
561 return -ENOMEM;
562 }
563 rtn->ctl_table = tbl;
564 }
565 tbl[RDS_TCP_SNDBUF].data = &rtn->sndbuf_size;
566 tbl[RDS_TCP_RCVBUF].data = &rtn->rcvbuf_size;
567 rtn->rds_tcp_sysctl = register_net_sysctl_sz(net, "net/rds/tcp", tbl,
568 ARRAY_SIZE(rds_tcp_sysctl_table));
569 if (!rtn->rds_tcp_sysctl) {
570 pr_warn("could not register sysctl\n");
571 err = -ENOMEM;
572 goto fail;
573 }
574
575 #if IS_ENABLED(CONFIG_IPV6)
576 rtn->rds_tcp_listen_sock = rds_tcp_listen_init(net, true);
577 #else
578 rtn->rds_tcp_listen_sock = rds_tcp_listen_init(net, false);
579 #endif
580 if (!rtn->rds_tcp_listen_sock) {
581 pr_warn("could not set up IPv6 listen sock\n");
582
583 #if IS_ENABLED(CONFIG_IPV6)
584 /* Try IPv4 as some systems disable IPv6 */
585 rtn->rds_tcp_listen_sock = rds_tcp_listen_init(net, false);
586 if (!rtn->rds_tcp_listen_sock) {
587 #endif
588 unregister_net_sysctl_table(rtn->rds_tcp_sysctl);
589 rtn->rds_tcp_sysctl = NULL;
590 err = -EAFNOSUPPORT;
591 goto fail;
592 #if IS_ENABLED(CONFIG_IPV6)
593 }
594 #endif
595 }
596 INIT_WORK(&rtn->rds_tcp_accept_w, rds_tcp_accept_worker);
597 return 0;
598
599 fail:
600 if (net != &init_net)
601 kfree(tbl);
602 return err;
603 }
604
rds_tcp_kill_sock(struct net * net)605 static void rds_tcp_kill_sock(struct net *net)
606 {
607 struct rds_tcp_connection *tc, *_tc;
608 LIST_HEAD(tmp_list);
609 struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);
610 struct socket *lsock = rtn->rds_tcp_listen_sock;
611
612 rtn->rds_tcp_listen_sock = NULL;
613 rds_tcp_listen_stop(lsock, &rtn->rds_tcp_accept_w);
614 spin_lock_irq(&rds_tcp_conn_lock);
615 list_for_each_entry_safe(tc, _tc, &rds_tcp_conn_list, t_tcp_node) {
616 struct net *c_net = read_pnet(&tc->t_cpath->cp_conn->c_net);
617
618 if (net != c_net)
619 continue;
620 if (!list_has_conn(&tmp_list, tc->t_cpath->cp_conn)) {
621 list_move_tail(&tc->t_tcp_node, &tmp_list);
622 } else {
623 list_del(&tc->t_tcp_node);
624 tc->t_tcp_node_detached = true;
625 }
626 }
627 spin_unlock_irq(&rds_tcp_conn_lock);
628 list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node)
629 rds_conn_destroy(tc->t_cpath->cp_conn);
630 }
631
rds_tcp_exit_net(struct net * net)632 static void __net_exit rds_tcp_exit_net(struct net *net)
633 {
634 struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);
635
636 rds_tcp_kill_sock(net);
637
638 if (rtn->rds_tcp_sysctl)
639 unregister_net_sysctl_table(rtn->rds_tcp_sysctl);
640
641 if (net != &init_net)
642 kfree(rtn->ctl_table);
643 }
644
645 static struct pernet_operations rds_tcp_net_ops = {
646 .init = rds_tcp_init_net,
647 .exit = rds_tcp_exit_net,
648 .id = &rds_tcp_netid,
649 .size = sizeof(struct rds_tcp_net),
650 };
651
rds_tcp_listen_sock_def_readable(struct net * net)652 void *rds_tcp_listen_sock_def_readable(struct net *net)
653 {
654 struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid);
655 struct socket *lsock = rtn->rds_tcp_listen_sock;
656
657 if (!lsock)
658 return NULL;
659
660 return lsock->sk->sk_user_data;
661 }
662
663 /* when sysctl is used to modify some kernel socket parameters,this
664 * function resets the RDS connections in that netns so that we can
665 * restart with new parameters. The assumption is that such reset
666 * events are few and far-between.
667 */
rds_tcp_sysctl_reset(struct net * net)668 static void rds_tcp_sysctl_reset(struct net *net)
669 {
670 struct rds_tcp_connection *tc, *_tc;
671
672 spin_lock_irq(&rds_tcp_conn_lock);
673 list_for_each_entry_safe(tc, _tc, &rds_tcp_conn_list, t_tcp_node) {
674 struct net *c_net = read_pnet(&tc->t_cpath->cp_conn->c_net);
675
676 if (net != c_net || !tc->t_sock)
677 continue;
678
679 /* reconnect with new parameters */
680 rds_conn_path_drop(tc->t_cpath, false);
681 }
682 spin_unlock_irq(&rds_tcp_conn_lock);
683 }
684
rds_tcp_skbuf_handler(const struct ctl_table * ctl,int write,void * buffer,size_t * lenp,loff_t * fpos)685 static int rds_tcp_skbuf_handler(const struct ctl_table *ctl, int write,
686 void *buffer, size_t *lenp, loff_t *fpos)
687 {
688 struct net *net = current->nsproxy->net_ns;
689 int err;
690
691 err = proc_dointvec_minmax(ctl, write, buffer, lenp, fpos);
692 if (err < 0) {
693 pr_warn("Invalid input. Must be >= %d\n",
694 *(int *)(ctl->extra1));
695 return err;
696 }
697 if (write)
698 rds_tcp_sysctl_reset(net);
699 return 0;
700 }
701
rds_tcp_exit(void)702 static void rds_tcp_exit(void)
703 {
704 rds_tcp_set_unloading();
705 synchronize_rcu();
706 rds_info_deregister_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);
707 #if IS_ENABLED(CONFIG_IPV6)
708 rds_info_deregister_func(RDS6_INFO_TCP_SOCKETS, rds6_tcp_tc_info);
709 #endif
710 unregister_pernet_device(&rds_tcp_net_ops);
711 rds_tcp_destroy_conns();
712 rds_trans_unregister(&rds_tcp_transport);
713 rds_tcp_recv_exit();
714 kmem_cache_destroy(rds_tcp_conn_slab);
715 }
716 module_exit(rds_tcp_exit);
717
rds_tcp_init(void)718 static int __init rds_tcp_init(void)
719 {
720 int ret;
721
722 rds_tcp_conn_slab = KMEM_CACHE(rds_tcp_connection, 0);
723 if (!rds_tcp_conn_slab) {
724 ret = -ENOMEM;
725 goto out;
726 }
727
728 ret = rds_tcp_recv_init();
729 if (ret)
730 goto out_slab;
731
732 ret = register_pernet_device(&rds_tcp_net_ops);
733 if (ret)
734 goto out_recv;
735
736 rds_trans_register(&rds_tcp_transport);
737
738 rds_info_register_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);
739 #if IS_ENABLED(CONFIG_IPV6)
740 rds_info_register_func(RDS6_INFO_TCP_SOCKETS, rds6_tcp_tc_info);
741 #endif
742
743 goto out;
744 out_recv:
745 rds_tcp_recv_exit();
746 out_slab:
747 kmem_cache_destroy(rds_tcp_conn_slab);
748 out:
749 return ret;
750 }
751 module_init(rds_tcp_init);
752
753 MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
754 MODULE_DESCRIPTION("RDS: TCP transport");
755 MODULE_LICENSE("Dual BSD/GPL");
756