Root/net/rds/tcp_connect.c

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
40void 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(&sk->sk_callback_lock);
47    conn = sk->sk_user_data;
48    if (conn == NULL) {
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    }
70out:
71    read_unlock(&sk->sk_callback_lock);
72    state_change(sk);
73}
74
75int 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
115out:
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 */
130void 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

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