root/net/rds/tcp_connect.c

DEFINITIONS

1. rds_tcp_state_change
2. rds_tcp_conn_path_connect
3. rds_tcp_conn_path_shutdown

   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 }