xref: /openbmc/linux/net/rds/tcp_connect.c (revision ea3b1ea53930879c9847044f5cb9c97411cae797)
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_single_path.h"
38 #include "rds.h"
39 #include "tcp.h"
40 
41 void rds_tcp_state_change(struct sock *sk)
42 {
43 	void (*state_change)(struct sock *sk);
44 	struct rds_conn_path *cp;
45 	struct rds_tcp_connection *tc;
46 
47 	read_lock_bh(&sk->sk_callback_lock);
48 	cp = sk->sk_user_data;
49 	if (!cp) {
50 		state_change = sk->sk_state_change;
51 		goto out;
52 	}
53 	tc = cp->cp_transport_data;
54 	state_change = tc->t_orig_state_change;
55 
56 	rdsdebug("sock %p state_change to %d\n", tc->t_sock, sk->sk_state);
57 
58 	switch (sk->sk_state) {
59 	/* ignore connecting sockets as they make progress */
60 	case TCP_SYN_SENT:
61 	case TCP_SYN_RECV:
62 		break;
63 	case TCP_ESTABLISHED:
64 		rds_connect_path_complete(cp, RDS_CONN_CONNECTING);
65 		break;
66 	case TCP_CLOSE_WAIT:
67 	case TCP_CLOSE:
68 		rds_conn_path_drop(cp);
69 	default:
70 		break;
71 	}
72 out:
73 	read_unlock_bh(&sk->sk_callback_lock);
74 	state_change(sk);
75 }
76 
77 int rds_tcp_conn_connect(struct rds_connection *conn)
78 {
79 	struct socket *sock = NULL;
80 	struct sockaddr_in src, dest;
81 	int ret;
82 	struct rds_tcp_connection *tc = conn->c_transport_data;
83 	struct rds_conn_path *cp = &conn->c_path[0];
84 
85 	mutex_lock(&tc->t_conn_path_lock);
86 
87 	if (rds_conn_up(conn)) {
88 		mutex_unlock(&tc->t_conn_path_lock);
89 		return 0;
90 	}
91 	ret = sock_create_kern(rds_conn_net(conn), PF_INET,
92 			       SOCK_STREAM, IPPROTO_TCP, &sock);
93 	if (ret < 0)
94 		goto out;
95 
96 	rds_tcp_tune(sock);
97 
98 	src.sin_family = AF_INET;
99 	src.sin_addr.s_addr = (__force u32)conn->c_laddr;
100 	src.sin_port = (__force u16)htons(0);
101 
102 	ret = sock->ops->bind(sock, (struct sockaddr *)&src, sizeof(src));
103 	if (ret) {
104 		rdsdebug("bind failed with %d at address %pI4\n",
105 			 ret, &conn->c_laddr);
106 		goto out;
107 	}
108 
109 	dest.sin_family = AF_INET;
110 	dest.sin_addr.s_addr = (__force u32)conn->c_faddr;
111 	dest.sin_port = (__force u16)htons(RDS_TCP_PORT);
112 
113 	/*
114 	 * once we call connect() we can start getting callbacks and they
115 	 * own the socket
116 	 */
117 	rds_tcp_set_callbacks(sock, cp);
118 	ret = sock->ops->connect(sock, (struct sockaddr *)&dest, sizeof(dest),
119 				 O_NONBLOCK);
120 
121 	rdsdebug("connect to address %pI4 returned %d\n", &conn->c_faddr, ret);
122 	if (ret == -EINPROGRESS)
123 		ret = 0;
124 	if (ret == 0) {
125 		rds_tcp_keepalive(sock);
126 		sock = NULL;
127 	} else {
128 		rds_tcp_restore_callbacks(sock, conn->c_transport_data);
129 	}
130 
131 out:
132 	mutex_unlock(&tc->t_conn_path_lock);
133 	if (sock)
134 		sock_release(sock);
135 	return ret;
136 }
137 
138 /*
139  * Before killing the tcp socket this needs to serialize with callbacks.  The
140  * caller has already grabbed the sending sem so we're serialized with other
141  * senders.
142  *
143  * TCP calls the callbacks with the sock lock so we hold it while we reset the
144  * callbacks to those set by TCP.  Our callbacks won't execute again once we
145  * hold the sock lock.
146  */
147 void rds_tcp_conn_path_shutdown(struct rds_conn_path *cp)
148 {
149 	struct rds_tcp_connection *tc = cp->cp_transport_data;
150 	struct socket *sock = tc->t_sock;
151 
152 	rdsdebug("shutting down conn %p tc %p sock %p\n",
153 		 cp->cp_conn, tc, sock);
154 
155 	if (sock) {
156 		sock->ops->shutdown(sock, RCV_SHUTDOWN | SEND_SHUTDOWN);
157 		lock_sock(sock->sk);
158 		rds_tcp_restore_callbacks(sock, tc); /* tc->tc_sock = NULL */
159 
160 		release_sock(sock->sk);
161 		sock_release(sock);
162 	}
163 
164 	if (tc->t_tinc) {
165 		rds_inc_put(&tc->t_tinc->ti_inc);
166 		tc->t_tinc = NULL;
167 	}
168 	tc->t_tinc_hdr_rem = sizeof(struct rds_header);
169 	tc->t_tinc_data_rem = 0;
170 }
171