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
rds_tcp_keepalive(struct socket * sock)41 int 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));
69 bail:
70 return ret;
71 }
72
rds_tcp_accept_one(struct socket * sock)73 int rds_tcp_accept_one(struct socket *sock)
74 {
75 struct socket *new_sock = NULL;
76 struct rds_connection *conn;
77 int ret;
78 struct inet_sock *inet;
79 struct rds_tcp_connection *rs_tcp;
80
81 ret = sock_create_lite(sock->sk->sk_family,
82 sock->sk->sk_type, sock->sk->sk_protocol,
83 &new_sock);
84 if (ret)
85 goto out;
86
87 new_sock->type = sock->type;
88 new_sock->ops = sock->ops;
89 ret = sock->ops->accept(sock, new_sock, O_NONBLOCK);
90 if (ret < 0)
91 goto out;
92
93 ret = rds_tcp_keepalive(new_sock);
94 if (ret < 0)
95 goto out;
96
97 rds_tcp_tune(new_sock);
98
99 inet = inet_sk(new_sock->sk);
100
101 rdsdebug("accepted tcp %pI4:%u -> %pI4:%u\n",
102 &inet->inet_saddr, ntohs(inet->inet_sport),
103 &inet->inet_daddr, ntohs(inet->inet_dport));
104
105 conn = rds_conn_create(sock_net(sock->sk),
106 inet->inet_saddr, inet->inet_daddr,
107 &rds_tcp_transport, GFP_KERNEL);
108 if (IS_ERR(conn)) {
109 ret = PTR_ERR(conn);
110 goto out;
111 }
112 /* An incoming SYN request came in, and TCP just accepted it.
113 *
114 * If the client reboots, this conn will need to be cleaned up.
115 * rds_tcp_state_change() will do that cleanup
116 */
117 rs_tcp = (struct rds_tcp_connection *)conn->c_transport_data;
118 rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_CONNECTING);
119 if (rs_tcp->t_sock) {
120 /* Need to resolve a duelling SYN between peers.
121 * We have an outstanding SYN to this peer, which may
122 * potentially have transitioned to the RDS_CONN_UP state,
123 * so we must quiesce any send threads before resetting
124 * c_transport_data.
125 */
126 wait_event(conn->c_waitq,
127 !test_bit(RDS_IN_XMIT, &conn->c_flags));
128 if (ntohl(inet->inet_saddr) < ntohl(inet->inet_daddr)) {
129 struct sock *nsk = new_sock->sk;
130
131 nsk->sk_user_data = NULL;
132 nsk->sk_prot->disconnect(nsk, 0);
133 tcp_done(nsk);
134 new_sock = NULL;
135 ret = 0;
136 goto out;
137 } else if (rs_tcp->t_sock) {
138 rds_tcp_restore_callbacks(rs_tcp->t_sock, rs_tcp);
139 conn->c_outgoing = 0;
140 }
141 }
142 rds_tcp_set_callbacks(new_sock, conn);
143 rds_connect_complete(conn); /* marks RDS_CONN_UP */
144 new_sock = NULL;
145 ret = 0;
146
147 out:
148 if (new_sock)
149 sock_release(new_sock);
150 return ret;
151 }
152
rds_tcp_listen_data_ready(struct sock * sk)153 void rds_tcp_listen_data_ready(struct sock *sk)
154 {
155 void (*ready)(struct sock *sk);
156
157 rdsdebug("listen data ready sk %p\n", sk);
158
159 read_lock(&sk->sk_callback_lock);
160 ready = sk->sk_user_data;
161 if (!ready) { /* check for teardown race */
162 ready = sk->sk_data_ready;
163 goto out;
164 }
165
166 /*
167 * ->sk_data_ready is also called for a newly established child socket
168 * before it has been accepted and the accepter has set up their
169 * data_ready.. we only want to queue listen work for our listening
170 * socket
171 */
172 if (sk->sk_state == TCP_LISTEN)
173 rds_tcp_accept_work(sk);
174
175 out:
176 read_unlock(&sk->sk_callback_lock);
177 ready(sk);
178 }
179
rds_tcp_listen_init(struct net * net)180 struct socket *rds_tcp_listen_init(struct net *net)
181 {
182 struct sockaddr_in sin;
183 struct socket *sock = NULL;
184 int ret;
185
186 ret = sock_create_kern(net, PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
187 if (ret < 0)
188 goto out;
189
190 sock->sk->sk_reuse = SK_CAN_REUSE;
191 rds_tcp_nonagle(sock);
192
193 write_lock_bh(&sock->sk->sk_callback_lock);
194 sock->sk->sk_user_data = sock->sk->sk_data_ready;
195 sock->sk->sk_data_ready = rds_tcp_listen_data_ready;
196 write_unlock_bh(&sock->sk->sk_callback_lock);
197
198 sin.sin_family = PF_INET;
199 sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
200 sin.sin_port = (__force u16)htons(RDS_TCP_PORT);
201
202 ret = sock->ops->bind(sock, (struct sockaddr *)&sin, sizeof(sin));
203 if (ret < 0)
204 goto out;
205
206 ret = sock->ops->listen(sock, 64);
207 if (ret < 0)
208 goto out;
209
210 return sock;
211 out:
212 if (sock)
213 sock_release(sock);
214 return NULL;
215 }
216
rds_tcp_listen_stop(struct socket * sock)217 void rds_tcp_listen_stop(struct socket *sock)
218 {
219 struct sock *sk;
220
221 if (!sock)
222 return;
223
224 sk = sock->sk;
225
226 /* serialize with and prevent further callbacks */
227 lock_sock(sk);
228 write_lock_bh(&sk->sk_callback_lock);
229 if (sk->sk_user_data) {
230 sk->sk_data_ready = sk->sk_user_data;
231 sk->sk_user_data = NULL;
232 }
233 write_unlock_bh(&sk->sk_callback_lock);
234 release_sock(sk);
235
236 /* wait for accepts to stop and close the socket */
237 flush_workqueue(rds_wq);
238 sock_release(sock);
239 }
240