xref: /openbmc/linux/net/rds/tcp_connect.c (revision 37744fee)
1 /*
2  * Copyright (c) 2006, 2017 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/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_conn_path *cp;
44 	struct rds_tcp_connection *tc;
45 
46 	read_lock_bh(&sk->sk_callback_lock);
47 	cp = sk->sk_user_data;
48 	if (!cp) {
49 		state_change = sk->sk_state_change;
50 		goto out;
51 	}
52 	tc = cp->cp_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 		/* Force the peer to reconnect so that we have the
64 		 * TCP ports going from <smaller-ip>.<transient> to
65 		 * <larger-ip>.<RDS_TCP_PORT>. We avoid marking the
66 		 * RDS connection as RDS_CONN_UP until the reconnect,
67 		 * to avoid RDS datagram loss.
68 		 */
69 		if (rds_addr_cmp(&cp->cp_conn->c_laddr,
70 				 &cp->cp_conn->c_faddr) >= 0 &&
71 		    rds_conn_path_transition(cp, RDS_CONN_CONNECTING,
72 					     RDS_CONN_ERROR)) {
73 			rds_conn_path_drop(cp, false);
74 		} else {
75 			rds_connect_path_complete(cp, RDS_CONN_CONNECTING);
76 		}
77 		break;
78 	case TCP_CLOSE_WAIT:
79 	case TCP_CLOSE:
80 		rds_conn_path_drop(cp, false);
81 	default:
82 		break;
83 	}
84 out:
85 	read_unlock_bh(&sk->sk_callback_lock);
86 	state_change(sk);
87 }
88 
89 int rds_tcp_conn_path_connect(struct rds_conn_path *cp)
90 {
91 	struct socket *sock = NULL;
92 	struct sockaddr_in6 sin6;
93 	struct sockaddr_in sin;
94 	struct sockaddr *addr;
95 	int addrlen;
96 	bool isv6;
97 	int ret;
98 	struct rds_connection *conn = cp->cp_conn;
99 	struct rds_tcp_connection *tc = cp->cp_transport_data;
100 
101 	/* for multipath rds,we only trigger the connection after
102 	 * the handshake probe has determined the number of paths.
103 	 */
104 	if (cp->cp_index > 0 && cp->cp_conn->c_npaths < 2)
105 		return -EAGAIN;
106 
107 	mutex_lock(&tc->t_conn_path_lock);
108 
109 	if (rds_conn_path_up(cp)) {
110 		mutex_unlock(&tc->t_conn_path_lock);
111 		return 0;
112 	}
113 	if (ipv6_addr_v4mapped(&conn->c_laddr)) {
114 		ret = sock_create_kern(rds_conn_net(conn), PF_INET,
115 				       SOCK_STREAM, IPPROTO_TCP, &sock);
116 		isv6 = false;
117 	} else {
118 		ret = sock_create_kern(rds_conn_net(conn), PF_INET6,
119 				       SOCK_STREAM, IPPROTO_TCP, &sock);
120 		isv6 = true;
121 	}
122 
123 	if (ret < 0)
124 		goto out;
125 
126 	rds_tcp_tune(sock);
127 
128 	if (isv6) {
129 		sin6.sin6_family = AF_INET6;
130 		sin6.sin6_addr = conn->c_laddr;
131 		sin6.sin6_port = 0;
132 		sin6.sin6_flowinfo = 0;
133 		sin6.sin6_scope_id = conn->c_dev_if;
134 		addr = (struct sockaddr *)&sin6;
135 		addrlen = sizeof(sin6);
136 	} else {
137 		sin.sin_family = AF_INET;
138 		sin.sin_addr.s_addr = conn->c_laddr.s6_addr32[3];
139 		sin.sin_port = 0;
140 		addr = (struct sockaddr *)&sin;
141 		addrlen = sizeof(sin);
142 	}
143 
144 	ret = sock->ops->bind(sock, addr, addrlen);
145 	if (ret) {
146 		rdsdebug("bind failed with %d at address %pI6c\n",
147 			 ret, &conn->c_laddr);
148 		goto out;
149 	}
150 
151 	if (isv6) {
152 		sin6.sin6_family = AF_INET6;
153 		sin6.sin6_addr = conn->c_faddr;
154 		sin6.sin6_port = htons(RDS_TCP_PORT);
155 		sin6.sin6_flowinfo = 0;
156 		sin6.sin6_scope_id = conn->c_dev_if;
157 		addr = (struct sockaddr *)&sin6;
158 		addrlen = sizeof(sin6);
159 	} else {
160 		sin.sin_family = AF_INET;
161 		sin.sin_addr.s_addr = conn->c_faddr.s6_addr32[3];
162 		sin.sin_port = htons(RDS_TCP_PORT);
163 		addr = (struct sockaddr *)&sin;
164 		addrlen = sizeof(sin);
165 	}
166 
167 	/*
168 	 * once we call connect() we can start getting callbacks and they
169 	 * own the socket
170 	 */
171 	rds_tcp_set_callbacks(sock, cp);
172 	ret = sock->ops->connect(sock, addr, addrlen, O_NONBLOCK);
173 
174 	rdsdebug("connect to address %pI6c returned %d\n", &conn->c_faddr, ret);
175 	if (ret == -EINPROGRESS)
176 		ret = 0;
177 	if (ret == 0) {
178 		rds_tcp_keepalive(sock);
179 		sock = NULL;
180 	} else {
181 		rds_tcp_restore_callbacks(sock, cp->cp_transport_data);
182 	}
183 
184 out:
185 	mutex_unlock(&tc->t_conn_path_lock);
186 	if (sock)
187 		sock_release(sock);
188 	return ret;
189 }
190 
191 /*
192  * Before killing the tcp socket this needs to serialize with callbacks.  The
193  * caller has already grabbed the sending sem so we're serialized with other
194  * senders.
195  *
196  * TCP calls the callbacks with the sock lock so we hold it while we reset the
197  * callbacks to those set by TCP.  Our callbacks won't execute again once we
198  * hold the sock lock.
199  */
200 void rds_tcp_conn_path_shutdown(struct rds_conn_path *cp)
201 {
202 	struct rds_tcp_connection *tc = cp->cp_transport_data;
203 	struct socket *sock = tc->t_sock;
204 
205 	rdsdebug("shutting down conn %p tc %p sock %p\n",
206 		 cp->cp_conn, tc, sock);
207 
208 	if (sock) {
209 		if (rds_destroy_pending(cp->cp_conn))
210 			rds_tcp_set_linger(sock);
211 		sock->ops->shutdown(sock, RCV_SHUTDOWN | SEND_SHUTDOWN);
212 		lock_sock(sock->sk);
213 		rds_tcp_restore_callbacks(sock, tc); /* tc->tc_sock = NULL */
214 
215 		release_sock(sock->sk);
216 		sock_release(sock);
217 	}
218 
219 	if (tc->t_tinc) {
220 		rds_inc_put(&tc->t_tinc->ti_inc);
221 		tc->t_tinc = NULL;
222 	}
223 	tc->t_tinc_hdr_rem = sizeof(struct rds_header);
224 	tc->t_tinc_data_rem = 0;
225 }
226