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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/gfp.h>
35#include <linux/in.h>
36#include <net/tcp.h>
37
38#include "rds.h"
39#include "tcp.h"
40
41/*
42 * cheesy, but simple..
43 */
44static void rds_tcp_accept_worker(struct work_struct *work);
45static DECLARE_WORK(rds_tcp_listen_work, rds_tcp_accept_worker);
46static struct socket *rds_tcp_listen_sock;
47
48static int rds_tcp_accept_one(struct socket *sock)
49{
50 struct socket *new_sock = NULL;
51 struct rds_connection *conn;
52 int ret;
53 struct inet_sock *inet;
54
55 ret = sock_create_lite(sock->sk->sk_family, sock->sk->sk_type,
56 sock->sk->sk_protocol, &new_sock);
57 if (ret)
58 goto out;
59
60 new_sock->type = sock->type;
61 new_sock->ops = sock->ops;
62 ret = sock->ops->accept(sock, new_sock, O_NONBLOCK);
63 if (ret < 0)
64 goto out;
65
66 rds_tcp_tune(new_sock);
67
68 inet = inet_sk(new_sock->sk);
69
70 rdsdebug("accepted tcp %pI4:%u -> %pI4:%u\n",
71 &inet->inet_saddr, ntohs(inet->inet_sport),
72 &inet->inet_daddr, ntohs(inet->inet_dport));
73
74 conn = rds_conn_create(inet->inet_saddr, inet->inet_daddr,
75 &rds_tcp_transport, GFP_KERNEL);
76 if (IS_ERR(conn)) {
77 ret = PTR_ERR(conn);
78 goto out;
79 }
80
81 /*
82 * see the comment above rds_queue_delayed_reconnect()
83 */
84 if (!rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_CONNECTING)) {
85 if (rds_conn_state(conn) == RDS_CONN_UP)
86 rds_tcp_stats_inc(s_tcp_listen_closed_stale);
87 else
88 rds_tcp_stats_inc(s_tcp_connect_raced);
89 rds_conn_drop(conn);
90 ret = 0;
91 goto out;
92 }
93
94 rds_tcp_set_callbacks(new_sock, conn);
95 rds_connect_complete(conn);
96 new_sock = NULL;
97 ret = 0;
98
99out:
100 if (new_sock)
101 sock_release(new_sock);
102 return ret;
103}
104
105static void rds_tcp_accept_worker(struct work_struct *work)
106{
107 while (rds_tcp_accept_one(rds_tcp_listen_sock) == 0)
108 cond_resched();
109}
110
111void rds_tcp_listen_data_ready(struct sock *sk, int bytes)
112{
113 void (*ready)(struct sock *sk, int bytes);
114
115 rdsdebug("listen data ready sk %p\n", sk);
116
117 read_lock_bh(&sk->sk_callback_lock);
118 ready = sk->sk_user_data;
119 if (!ready) { /* check for teardown race */
120 ready = sk->sk_data_ready;
121 goto out;
122 }
123
124 /*
125 * ->sk_data_ready is also called for a newly established child socket
126 * before it has been accepted and the accepter has set up their
127 * data_ready.. we only want to queue listen work for our listening
128 * socket
129 */
130 if (sk->sk_state == TCP_LISTEN)
131 queue_work(rds_wq, &rds_tcp_listen_work);
132
133out:
134 read_unlock_bh(&sk->sk_callback_lock);
135 ready(sk, bytes);
136}
137
138int rds_tcp_listen_init(void)
139{
140 struct sockaddr_in sin;
141 struct socket *sock = NULL;
142 int ret;
143
144 ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
145 if (ret < 0)
146 goto out;
147
148 sock->sk->sk_reuse = SK_CAN_REUSE;
149 rds_tcp_nonagle(sock);
150
151 write_lock_bh(&sock->sk->sk_callback_lock);
152 sock->sk->sk_user_data = sock->sk->sk_data_ready;
153 sock->sk->sk_data_ready = rds_tcp_listen_data_ready;
154 write_unlock_bh(&sock->sk->sk_callback_lock);
155
156 sin.sin_family = PF_INET,
157 sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
158 sin.sin_port = (__force u16)htons(RDS_TCP_PORT);
159
160 ret = sock->ops->bind(sock, (struct sockaddr *)&sin, sizeof(sin));
161 if (ret < 0)
162 goto out;
163
164 ret = sock->ops->listen(sock, 64);
165 if (ret < 0)
166 goto out;
167
168 rds_tcp_listen_sock = sock;
169 sock = NULL;
170out:
171 if (sock)
172 sock_release(sock);
173 return ret;
174}
175
176void rds_tcp_listen_stop(void)
177{
178 struct socket *sock = rds_tcp_listen_sock;
179 struct sock *sk;
180
181 if (!sock)
182 return;
183
184 sk = sock->sk;
185
186 /* serialize with and prevent further callbacks */
187 lock_sock(sk);
188 write_lock_bh(&sk->sk_callback_lock);
189 if (sk->sk_user_data) {
190 sk->sk_data_ready = sk->sk_user_data;
191 sk->sk_user_data = NULL;
192 }
193 write_unlock_bh(&sk->sk_callback_lock);
194 release_sock(sk);
195
196 /* wait for accepts to stop and close the socket */
197 flush_workqueue(rds_wq);
198 sock_release(sock);
199 rds_tcp_listen_sock = NULL;
200}
1/*
2 * Copyright (c) 2006, 2018 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/gfp.h>
35#include <linux/in.h>
36#include <net/tcp.h>
37
38#include "rds.h"
39#include "tcp.h"
40
41int rds_tcp_keepalive(struct socket *sock)
42{
43 /* values below based on xs_udp_default_timeout */
44 int keepidle = 5; /* send a probe 'keepidle' secs after last data */
45 int keepcnt = 5; /* number of unack'ed probes before declaring dead */
46 int keepalive = 1;
47 int ret = 0;
48
49 ret = kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
50 (char *)&keepalive, sizeof(keepalive));
51 if (ret < 0)
52 goto bail;
53
54 ret = kernel_setsockopt(sock, IPPROTO_TCP, TCP_KEEPCNT,
55 (char *)&keepcnt, sizeof(keepcnt));
56 if (ret < 0)
57 goto bail;
58
59 ret = kernel_setsockopt(sock, IPPROTO_TCP, TCP_KEEPIDLE,
60 (char *)&keepidle, sizeof(keepidle));
61 if (ret < 0)
62 goto bail;
63
64 /* KEEPINTVL is the interval between successive probes. We follow
65 * the model in xs_tcp_finish_connecting() and re-use keepidle.
66 */
67 ret = kernel_setsockopt(sock, IPPROTO_TCP, TCP_KEEPINTVL,
68 (char *)&keepidle, sizeof(keepidle));
69bail:
70 return ret;
71}
72
73/* rds_tcp_accept_one_path(): if accepting on cp_index > 0, make sure the
74 * client's ipaddr < server's ipaddr. Otherwise, close the accepted
75 * socket and force a reconneect from smaller -> larger ip addr. The reason
76 * we special case cp_index 0 is to allow the rds probe ping itself to itself
77 * get through efficiently.
78 * Since reconnects are only initiated from the node with the numerically
79 * smaller ip address, we recycle conns in RDS_CONN_ERROR on the passive side
80 * by moving them to CONNECTING in this function.
81 */
82static
83struct rds_tcp_connection *rds_tcp_accept_one_path(struct rds_connection *conn)
84{
85 int i;
86 bool peer_is_smaller = IS_CANONICAL(conn->c_faddr, conn->c_laddr);
87 int npaths = max_t(int, 1, conn->c_npaths);
88
89 /* for mprds, all paths MUST be initiated by the peer
90 * with the smaller address.
91 */
92 if (!peer_is_smaller) {
93 /* Make sure we initiate at least one path if this
94 * has not already been done; rds_start_mprds() will
95 * take care of additional paths, if necessary.
96 */
97 if (npaths == 1)
98 rds_conn_path_connect_if_down(&conn->c_path[0]);
99 return NULL;
100 }
101
102 for (i = 0; i < npaths; i++) {
103 struct rds_conn_path *cp = &conn->c_path[i];
104
105 if (rds_conn_path_transition(cp, RDS_CONN_DOWN,
106 RDS_CONN_CONNECTING) ||
107 rds_conn_path_transition(cp, RDS_CONN_ERROR,
108 RDS_CONN_CONNECTING)) {
109 return cp->cp_transport_data;
110 }
111 }
112 return NULL;
113}
114
115void rds_tcp_set_linger(struct socket *sock)
116{
117 struct linger no_linger = {
118 .l_onoff = 1,
119 .l_linger = 0,
120 };
121
122 kernel_setsockopt(sock, SOL_SOCKET, SO_LINGER,
123 (char *)&no_linger, sizeof(no_linger));
124}
125
126int rds_tcp_accept_one(struct socket *sock)
127{
128 struct socket *new_sock = NULL;
129 struct rds_connection *conn;
130 int ret;
131 struct inet_sock *inet;
132 struct rds_tcp_connection *rs_tcp = NULL;
133 int conn_state;
134 struct rds_conn_path *cp;
135
136 if (!sock) /* module unload or netns delete in progress */
137 return -ENETUNREACH;
138
139 ret = sock_create_lite(sock->sk->sk_family,
140 sock->sk->sk_type, sock->sk->sk_protocol,
141 &new_sock);
142 if (ret)
143 goto out;
144
145 ret = sock->ops->accept(sock, new_sock, O_NONBLOCK, true);
146 if (ret < 0)
147 goto out;
148
149 /* sock_create_lite() does not get a hold on the owner module so we
150 * need to do it here. Note that sock_release() uses sock->ops to
151 * determine if it needs to decrement the reference count. So set
152 * sock->ops after calling accept() in case that fails. And there's
153 * no need to do try_module_get() as the listener should have a hold
154 * already.
155 */
156 new_sock->ops = sock->ops;
157 __module_get(new_sock->ops->owner);
158
159 ret = rds_tcp_keepalive(new_sock);
160 if (ret < 0)
161 goto out;
162
163 rds_tcp_tune(new_sock);
164
165 inet = inet_sk(new_sock->sk);
166
167 rdsdebug("accepted tcp %pI4:%u -> %pI4:%u\n",
168 &inet->inet_saddr, ntohs(inet->inet_sport),
169 &inet->inet_daddr, ntohs(inet->inet_dport));
170
171 conn = rds_conn_create(sock_net(sock->sk),
172 inet->inet_saddr, inet->inet_daddr,
173 &rds_tcp_transport, GFP_KERNEL);
174 if (IS_ERR(conn)) {
175 ret = PTR_ERR(conn);
176 goto out;
177 }
178 /* An incoming SYN request came in, and TCP just accepted it.
179 *
180 * If the client reboots, this conn will need to be cleaned up.
181 * rds_tcp_state_change() will do that cleanup
182 */
183 rs_tcp = rds_tcp_accept_one_path(conn);
184 if (!rs_tcp)
185 goto rst_nsk;
186 mutex_lock(&rs_tcp->t_conn_path_lock);
187 cp = rs_tcp->t_cpath;
188 conn_state = rds_conn_path_state(cp);
189 WARN_ON(conn_state == RDS_CONN_UP);
190 if (conn_state != RDS_CONN_CONNECTING && conn_state != RDS_CONN_ERROR)
191 goto rst_nsk;
192 if (rs_tcp->t_sock) {
193 /* Duelling SYN has been handled in rds_tcp_accept_one() */
194 rds_tcp_reset_callbacks(new_sock, cp);
195 /* rds_connect_path_complete() marks RDS_CONN_UP */
196 rds_connect_path_complete(cp, RDS_CONN_RESETTING);
197 } else {
198 rds_tcp_set_callbacks(new_sock, cp);
199 rds_connect_path_complete(cp, RDS_CONN_CONNECTING);
200 }
201 new_sock = NULL;
202 ret = 0;
203 if (conn->c_npaths == 0)
204 rds_send_ping(cp->cp_conn, cp->cp_index);
205 goto out;
206rst_nsk:
207 /* reset the newly returned accept sock and bail.
208 * It is safe to set linger on new_sock because the RDS connection
209 * has not been brought up on new_sock, so no RDS-level data could
210 * be pending on it. By setting linger, we achieve the side-effect
211 * of avoiding TIME_WAIT state on new_sock.
212 */
213 rds_tcp_set_linger(new_sock);
214 kernel_sock_shutdown(new_sock, SHUT_RDWR);
215 ret = 0;
216out:
217 if (rs_tcp)
218 mutex_unlock(&rs_tcp->t_conn_path_lock);
219 if (new_sock)
220 sock_release(new_sock);
221 return ret;
222}
223
224void rds_tcp_listen_data_ready(struct sock *sk)
225{
226 void (*ready)(struct sock *sk);
227
228 rdsdebug("listen data ready sk %p\n", sk);
229
230 read_lock_bh(&sk->sk_callback_lock);
231 ready = sk->sk_user_data;
232 if (!ready) { /* check for teardown race */
233 ready = sk->sk_data_ready;
234 goto out;
235 }
236
237 /*
238 * ->sk_data_ready is also called for a newly established child socket
239 * before it has been accepted and the accepter has set up their
240 * data_ready.. we only want to queue listen work for our listening
241 * socket
242 *
243 * (*ready)() may be null if we are racing with netns delete, and
244 * the listen socket is being torn down.
245 */
246 if (sk->sk_state == TCP_LISTEN)
247 rds_tcp_accept_work(sk);
248 else
249 ready = rds_tcp_listen_sock_def_readable(sock_net(sk));
250
251out:
252 read_unlock_bh(&sk->sk_callback_lock);
253 if (ready)
254 ready(sk);
255}
256
257struct socket *rds_tcp_listen_init(struct net *net)
258{
259 struct sockaddr_in sin;
260 struct socket *sock = NULL;
261 int ret;
262
263 ret = sock_create_kern(net, PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
264 if (ret < 0)
265 goto out;
266
267 sock->sk->sk_reuse = SK_CAN_REUSE;
268 rds_tcp_nonagle(sock);
269
270 write_lock_bh(&sock->sk->sk_callback_lock);
271 sock->sk->sk_user_data = sock->sk->sk_data_ready;
272 sock->sk->sk_data_ready = rds_tcp_listen_data_ready;
273 write_unlock_bh(&sock->sk->sk_callback_lock);
274
275 sin.sin_family = PF_INET;
276 sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
277 sin.sin_port = (__force u16)htons(RDS_TCP_PORT);
278
279 ret = sock->ops->bind(sock, (struct sockaddr *)&sin, sizeof(sin));
280 if (ret < 0)
281 goto out;
282
283 ret = sock->ops->listen(sock, 64);
284 if (ret < 0)
285 goto out;
286
287 return sock;
288out:
289 if (sock)
290 sock_release(sock);
291 return NULL;
292}
293
294void rds_tcp_listen_stop(struct socket *sock, struct work_struct *acceptor)
295{
296 struct sock *sk;
297
298 if (!sock)
299 return;
300
301 sk = sock->sk;
302
303 /* serialize with and prevent further callbacks */
304 lock_sock(sk);
305 write_lock_bh(&sk->sk_callback_lock);
306 if (sk->sk_user_data) {
307 sk->sk_data_ready = sk->sk_user_data;
308 sk->sk_user_data = NULL;
309 }
310 write_unlock_bh(&sk->sk_callback_lock);
311 release_sock(sk);
312
313 /* wait for accepts to stop and close the socket */
314 flush_workqueue(rds_wq);
315 flush_work(acceptor);
316 sock_release(sock);
317}