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/*
* Copyright (c) 2006 Oracle. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
*/
#include <linux/kernel.h>
#include <linux/gfp.h>
#include <linux/in.h>
#include <net/tcp.h>
#include "rds.h"
#include "tcp.h"
int rds_tcp_keepalive(struct socket *sock)
{
/* values below based on xs_udp_default_timeout */
int keepidle = 5; /* send a probe 'keepidle' secs after last data */
int keepcnt = 5; /* number of unack'ed probes before declaring dead */
int keepalive = 1;
int ret = 0;
ret = kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
(char *)&keepalive, sizeof(keepalive));
if (ret < 0)
goto bail;
ret = kernel_setsockopt(sock, IPPROTO_TCP, TCP_KEEPCNT,
(char *)&keepcnt, sizeof(keepcnt));
if (ret < 0)
goto bail;
ret = kernel_setsockopt(sock, IPPROTO_TCP, TCP_KEEPIDLE,
(char *)&keepidle, sizeof(keepidle));
if (ret < 0)
goto bail;
/* KEEPINTVL is the interval between successive probes. We follow
* the model in xs_tcp_finish_connecting() and re-use keepidle.
*/
ret = kernel_setsockopt(sock, IPPROTO_TCP, TCP_KEEPINTVL,
(char *)&keepidle, sizeof(keepidle));
bail:
return ret;
}
int rds_tcp_accept_one(struct socket *sock)
{
struct socket *new_sock = NULL;
struct rds_connection *conn;
int ret;
struct inet_sock *inet;
struct rds_tcp_connection *rs_tcp = NULL;
int conn_state;
struct sock *nsk;
if (!sock) /* module unload or netns delete in progress */
return -ENETUNREACH;
ret = sock_create_kern(sock_net(sock->sk), sock->sk->sk_family,
sock->sk->sk_type, sock->sk->sk_protocol,
&new_sock);
if (ret)
goto out;
new_sock->type = sock->type;
new_sock->ops = sock->ops;
ret = sock->ops->accept(sock, new_sock, O_NONBLOCK);
if (ret < 0)
goto out;
ret = rds_tcp_keepalive(new_sock);
if (ret < 0)
goto out;
rds_tcp_tune(new_sock);
inet = inet_sk(new_sock->sk);
rdsdebug("accepted tcp %pI4:%u -> %pI4:%u\n",
&inet->inet_saddr, ntohs(inet->inet_sport),
&inet->inet_daddr, ntohs(inet->inet_dport));
conn = rds_conn_create(sock_net(sock->sk),
inet->inet_saddr, inet->inet_daddr,
&rds_tcp_transport, GFP_KERNEL);
if (IS_ERR(conn)) {
ret = PTR_ERR(conn);
goto out;
}
/* An incoming SYN request came in, and TCP just accepted it.
*
* If the client reboots, this conn will need to be cleaned up.
* rds_tcp_state_change() will do that cleanup
*/
rs_tcp = (struct rds_tcp_connection *)conn->c_transport_data;
rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_CONNECTING);
mutex_lock(&rs_tcp->t_conn_lock);
conn_state = rds_conn_state(conn);
if (conn_state != RDS_CONN_CONNECTING && conn_state != RDS_CONN_UP)
goto rst_nsk;
if (rs_tcp->t_sock) {
/* Need to resolve a duelling SYN between peers.
* We have an outstanding SYN to this peer, which may
* potentially have transitioned to the RDS_CONN_UP state,
* so we must quiesce any send threads before resetting
* c_transport_data.
*/
if (ntohl(inet->inet_saddr) < ntohl(inet->inet_daddr) ||
!conn->c_outgoing) {
goto rst_nsk;
} else {
atomic_set(&conn->c_state, RDS_CONN_CONNECTING);
wait_event(conn->c_waitq,
!test_bit(RDS_IN_XMIT, &conn->c_flags));
rds_tcp_restore_callbacks(rs_tcp->t_sock, rs_tcp);
conn->c_outgoing = 0;
}
}
rds_tcp_set_callbacks(new_sock, conn);
rds_connect_complete(conn); /* marks RDS_CONN_UP */
new_sock = NULL;
ret = 0;
goto out;
rst_nsk:
/* reset the newly returned accept sock and bail */
nsk = new_sock->sk;
rds_tcp_stats_inc(s_tcp_listen_closed_stale);
nsk->sk_user_data = NULL;
nsk->sk_prot->disconnect(nsk, 0);
tcp_done(nsk);
new_sock = NULL;
ret = 0;
out:
if (rs_tcp)
mutex_unlock(&rs_tcp->t_conn_lock);
if (new_sock)
sock_release(new_sock);
return ret;
}
void rds_tcp_listen_data_ready(struct sock *sk)
{
void (*ready)(struct sock *sk);
rdsdebug("listen data ready sk %p\n", sk);
read_lock_bh(&sk->sk_callback_lock);
ready = sk->sk_user_data;
if (!ready) { /* check for teardown race */
ready = sk->sk_data_ready;
goto out;
}
/*
* ->sk_data_ready is also called for a newly established child socket
* before it has been accepted and the accepter has set up their
* data_ready.. we only want to queue listen work for our listening
* socket
*/
if (sk->sk_state == TCP_LISTEN)
rds_tcp_accept_work(sk);
out:
read_unlock_bh(&sk->sk_callback_lock);
ready(sk);
}
struct socket *rds_tcp_listen_init(struct net *net)
{
struct sockaddr_in sin;
struct socket *sock = NULL;
int ret;
ret = sock_create_kern(net, PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
if (ret < 0)
goto out;
sock->sk->sk_reuse = SK_CAN_REUSE;
rds_tcp_nonagle(sock);
write_lock_bh(&sock->sk->sk_callback_lock);
sock->sk->sk_user_data = sock->sk->sk_data_ready;
sock->sk->sk_data_ready = rds_tcp_listen_data_ready;
write_unlock_bh(&sock->sk->sk_callback_lock);
sin.sin_family = PF_INET;
sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
sin.sin_port = (__force u16)htons(RDS_TCP_PORT);
ret = sock->ops->bind(sock, (struct sockaddr *)&sin, sizeof(sin));
if (ret < 0)
goto out;
ret = sock->ops->listen(sock, 64);
if (ret < 0)
goto out;
return sock;
out:
if (sock)
sock_release(sock);
return NULL;
}
void rds_tcp_listen_stop(struct socket *sock)
{
struct sock *sk;
if (!sock)
return;
sk = sock->sk;
/* serialize with and prevent further callbacks */
lock_sock(sk);
write_lock_bh(&sk->sk_callback_lock);
if (sk->sk_user_data) {
sk->sk_data_ready = sk->sk_user_data;
sk->sk_user_data = NULL;
}
write_unlock_bh(&sk->sk_callback_lock);
release_sock(sk);
/* wait for accepts to stop and close the socket */
flush_workqueue(rds_wq);
sock_release(sock);
}
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