LXR linux/net/rds/tcp

   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) {
  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_WAIT:
  66                case TCP_CLOSE:
  67                        rds_conn_drop(conn);
  68                default:
  69                        break;
  70        }
  71out:
  72        read_unlock(&sk->sk_callback_lock);
  73        state_change(sk);
  74}
  75
  76int rds_tcp_conn_connect(struct rds_connection *conn)
  77{
  78        struct socket *sock = NULL;
  79        struct sockaddr_in src, dest;
  80        int ret;
  81        struct rds_tcp_connection *tc = conn->c_transport_data;
  82
  83        mutex_lock(&tc->t_conn_lock);
  84
  85        if (rds_conn_up(conn)) {
  86                mutex_unlock(&tc->t_conn_lock);
  87                return 0;
  88        }
  89        ret = sock_create_kern(rds_conn_net(conn), PF_INET,
  90                               SOCK_STREAM, IPPROTO_TCP, &sock);
  91        if (ret < 0)
  92                goto out;
  93
  94        rds_tcp_tune(sock);
  95
  96        src.sin_family = AF_INET;
  97        src.sin_addr.s_addr = (__force u32)conn->c_laddr;
  98        src.sin_port = (__force u16)htons(0);
  99
 100        ret = sock->ops->bind(sock, (struct sockaddr *)&src, sizeof(src));
 101        if (ret) {
 102                rdsdebug("bind failed with %d at address %pI4\n",
 103                         ret, &conn->c_laddr);
 104                goto out;
 105        }
 106
 107        dest.sin_family = AF_INET;
 108        dest.sin_addr.s_addr = (__force u32)conn->c_faddr;
 109        dest.sin_port = (__force u16)htons(RDS_TCP_PORT);
 110
 111        /*
 112         * once we call connect() we can start getting callbacks and they
 113         * own the socket
 114         */
 115        rds_tcp_set_callbacks(sock, conn);
 116        ret = sock->ops->connect(sock, (struct sockaddr *)&dest, sizeof(dest),
 117                                 O_NONBLOCK);
 118
 119        rdsdebug("connect to address %pI4 returned %d\n", &conn->c_faddr, ret);
 120        if (ret == -EINPROGRESS)
 121                ret = 0;
 122        if (ret == 0) {
 123                rds_tcp_keepalive(sock);
 124                sock = NULL;
 125        } else {
 126                rds_tcp_restore_callbacks(sock, conn->c_transport_data);
 127        }
 128
 129out:
 130        mutex_unlock(&tc->t_conn_lock);
 131        if (sock)
 132                sock_release(sock);
 133        return ret;
 134}
 135
 136/*
 137 * Before killing the tcp socket this needs to serialize with callbacks.  The
 138 * caller has already grabbed the sending sem so we're serialized with other
 139 * senders.
 140 *
 141 * TCP calls the callbacks with the sock lock so we hold it while we reset the
 142 * callbacks to those set by TCP.  Our callbacks won't execute again once we
 143 * hold the sock lock.
 144 */
 145void rds_tcp_conn_shutdown(struct rds_connection *conn)
 146{
 147        struct rds_tcp_connection *tc = conn->c_transport_data;
 148        struct socket *sock = tc->t_sock;
 149
 150        rdsdebug("shutting down conn %p tc %p sock %p\n", conn, tc, sock);
 151
 152        if (sock) {
 153                sock->ops->shutdown(sock, RCV_SHUTDOWN | SEND_SHUTDOWN);
 154                lock_sock(sock->sk);
 155                rds_tcp_restore_callbacks(sock, tc); /* tc->tc_sock = NULL */
 156
 157                release_sock(sock->sk);
 158                sock_release(sock);
 159        }
 160
 161        if (tc->t_tinc) {
 162                rds_inc_put(&tc->t_tinc->ti_inc);
 163                tc->t_tinc = NULL;
 164        }
 165        tc->t_tinc_hdr_rem = sizeof(struct rds_header);
 166        tc->t_tinc_data_rem = 0;
 167}
 168