xref: /linux/net/rds/tcp_connect.c (revision d524dac9279b6a41ffdf7ff7958c577f2e387db6)
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/in.h>
35 #include <net/tcp.h>
36 
37 #include "rds.h"
38 #include "tcp.h"
39 
40 void rds_tcp_state_change(struct sock *sk)
41 {
42 	void (*state_change)(struct sock *sk);
43 	struct rds_connection *conn;
44 	struct rds_tcp_connection *tc;
45 
46 	read_lock_bh(&sk->sk_callback_lock);
47 	conn = sk->sk_user_data;
48 	if (!conn) {
49 		state_change = sk->sk_state_change;
50 		goto out;
51 	}
52 	tc = conn->c_transport_data;
53 	state_change = tc->t_orig_state_change;
54 
55 	rdsdebug("sock %p state_change to %d\n", tc->t_sock, sk->sk_state);
56 
57 	switch(sk->sk_state) {
58 		/* ignore connecting sockets as they make progress */
59 		case TCP_SYN_SENT:
60 		case TCP_SYN_RECV:
61 			break;
62 		case TCP_ESTABLISHED:
63 			rds_connect_complete(conn);
64 			break;
65 		case TCP_CLOSE:
66 			rds_conn_drop(conn);
67 		default:
68 			break;
69 	}
70 out:
71 	read_unlock_bh(&sk->sk_callback_lock);
72 	state_change(sk);
73 }
74 
75 int rds_tcp_conn_connect(struct rds_connection *conn)
76 {
77 	struct socket *sock = NULL;
78 	struct sockaddr_in src, dest;
79 	int ret;
80 
81 	ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
82 	if (ret < 0)
83 		goto out;
84 
85 	rds_tcp_tune(sock);
86 
87 	src.sin_family = AF_INET;
88 	src.sin_addr.s_addr = (__force u32)conn->c_laddr;
89 	src.sin_port = (__force u16)htons(0);
90 
91 	ret = sock->ops->bind(sock, (struct sockaddr *)&src, sizeof(src));
92 	if (ret) {
93 		rdsdebug("bind failed with %d at address %pI4\n",
94 			 ret, &conn->c_laddr);
95 		goto out;
96 	}
97 
98 	dest.sin_family = AF_INET;
99 	dest.sin_addr.s_addr = (__force u32)conn->c_faddr;
100 	dest.sin_port = (__force u16)htons(RDS_TCP_PORT);
101 
102 	/*
103 	 * once we call connect() we can start getting callbacks and they
104 	 * own the socket
105 	 */
106 	rds_tcp_set_callbacks(sock, conn);
107 	ret = sock->ops->connect(sock, (struct sockaddr *)&dest, sizeof(dest),
108 				 O_NONBLOCK);
109 	sock = NULL;
110 
111 	rdsdebug("connect to address %pI4 returned %d\n", &conn->c_faddr, ret);
112 	if (ret == -EINPROGRESS)
113 		ret = 0;
114 
115 out:
116 	if (sock)
117 		sock_release(sock);
118 	return ret;
119 }
120 
121 /*
122  * Before killing the tcp socket this needs to serialize with callbacks.  The
123  * caller has already grabbed the sending sem so we're serialized with other
124  * senders.
125  *
126  * TCP calls the callbacks with the sock lock so we hold it while we reset the
127  * callbacks to those set by TCP.  Our callbacks won't execute again once we
128  * hold the sock lock.
129  */
130 void rds_tcp_conn_shutdown(struct rds_connection *conn)
131 {
132 	struct rds_tcp_connection *tc = conn->c_transport_data;
133 	struct socket *sock = tc->t_sock;
134 
135 	rdsdebug("shutting down conn %p tc %p sock %p\n", conn, tc, sock);
136 
137 	if (sock) {
138 		sock->ops->shutdown(sock, RCV_SHUTDOWN | SEND_SHUTDOWN);
139 		lock_sock(sock->sk);
140 		rds_tcp_restore_callbacks(sock, tc); /* tc->tc_sock = NULL */
141 
142 		release_sock(sock->sk);
143 		sock_release(sock);
144 	}
145 
146 	if (tc->t_tinc) {
147 		rds_inc_put(&tc->t_tinc->ti_inc);
148 		tc->t_tinc = NULL;
149 	}
150 	tc->t_tinc_hdr_rem = sizeof(struct rds_header);
151 	tc->t_tinc_data_rem = 0;
152 }
153