/*
* Copyright (c) 2006, 2018 Oracle and/or its affiliates. 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 <trace/events/sock.h>
#include "rds.h"
#include "tcp.h"
void 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 */
sock_set_keepalive(sock->sk);
tcp_sock_set_keepcnt(sock->sk, keepcnt);
tcp_sock_set_keepidle(sock->sk, keepidle);
/* KEEPINTVL is the interval between successive probes. We follow
* the model in xs_tcp_finish_connecting() and re-use keepidle.
*/
tcp_sock_set_keepintvl(sock->sk, keepidle);
}
/* rds_tcp_accept_one_path(): if accepting on cp_index > 0, make sure the
* client's ipaddr < server's ipaddr. Otherwise, close the accepted
* socket and force a reconneect from smaller -> larger ip addr. The reason
* we special case cp_index 0 is to allow the rds probe ping itself to itself
* get through efficiently.
* Since reconnects are only initiated from the node with the numerically
* smaller ip address, we recycle conns in RDS_CONN_ERROR on the passive side
* by moving them to CONNECTING in this function.
*/
static
struct rds_tcp_connection *rds_tcp_accept_one_path(struct rds_connection *conn)
{
int i;
int npaths = max_t(int, 1, conn->c_npaths);
/* for mprds, all paths MUST be initiated by the peer
* with the smaller address.
*/
if (rds_addr_cmp(&conn->c_faddr, &conn->c_laddr) >= 0) {
/* Make sure we initiate at least one path if this
* has not already been done; rds_start_mprds() will
* take care of additional paths, if necessary.
*/
if (npaths == 1)
rds_conn_path_connect_if_down(&conn->c_path[0]);
return NULL;
}
for (i = 0; i < npaths; i++) {
struct rds_conn_path *cp = &conn->c_path[i];
if (rds_conn_path_transition(cp, RDS_CONN_DOWN,
RDS_CONN_CONNECTING) ||
rds_conn_path_transition(cp, RDS_CONN_ERROR,
RDS_CONN_CONNECTING)) {
return cp->cp_transport_data;
}
}
return NULL;
}
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 rds_conn_path *cp;
struct in6_addr *my_addr, *peer_addr;
struct proto_accept_arg arg = {
.flags = O_NONBLOCK,
.kern = true,
};
#if !IS_ENABLED(CONFIG_IPV6)
struct in6_addr saddr, daddr;
#endif
int dev_if = 0;
if (!sock) /* module unload or netns delete in progress */
return -ENETUNREACH;
ret = sock_create_lite(sock->sk->sk_family,
sock->sk->sk_type, sock->sk->sk_protocol,
&new_sock);
if (ret)
goto out;
ret = sock->ops->accept(sock, new_sock, &arg);
if (ret < 0)
goto out;
/* sock_create_lite() does not get a hold on the owner module so we
* need to do it here. Note that sock_release() uses sock->ops to
* determine if it needs to decrement the reference count. So set
* sock->ops after calling accept() in case that fails. And there's
* no need to do try_module_get() as the listener should have a hold
* already.
*/
new_sock->ops = sock->ops;
__module_get(new_sock->ops->owner);
rds_tcp_keepalive(new_sock);
if (!rds_tcp_tune(new_sock)) {
ret = -EINVAL;
goto out;
}
inet = inet_sk(new_sock->sk);
#if IS_ENABLED(CONFIG_IPV6)
my_addr = &new_sock->sk->sk_v6_rcv_saddr;
peer_addr = &new_sock->sk->sk_v6_daddr;
#else
ipv6_addr_set_v4mapped(inet->inet_saddr, &saddr);
ipv6_addr_set_v4mapped(inet->inet_daddr, &daddr);
my_addr = &saddr;
peer_addr = &daddr;
#endif
rdsdebug("accepted family %d tcp %pI6c:%u -> %pI6c:%u\n",
sock->sk->sk_family,
my_addr, ntohs(inet->inet_sport),
peer_addr, ntohs(inet->inet_dport));
#if IS_ENABLED(CONFIG_IPV6)
/* sk_bound_dev_if is not set if the peer address is not link local
* address. In this case, it happens that mcast_oif is set. So
* just use it.
*/
if ((ipv6_addr_type(my_addr) & IPV6_ADDR_LINKLOCAL) &&
!(ipv6_addr_type(peer_addr) & IPV6_ADDR_LINKLOCAL)) {
struct ipv6_pinfo *inet6;
inet6 = inet6_sk(new_sock->sk);
dev_if = READ_ONCE(inet6->mcast_oif);
} else {
dev_if = new_sock->sk->sk_bound_dev_if;
}
#endif
if (!rds_tcp_laddr_check(sock_net(sock->sk), peer_addr, dev_if)) {
/* local address connection is only allowed via loopback */
ret = -EOPNOTSUPP;
goto out;
}
conn = rds_conn_create(sock_net(sock->sk),
my_addr, peer_addr,
&rds_tcp_transport, 0, GFP_KERNEL, dev_if);
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 = rds_tcp_accept_one_path(conn);
if (!rs_tcp)
goto rst_nsk;
mutex_lock(&rs_tcp->t_conn_path_lock);
cp = rs_tcp->t_cpath;
conn_state = rds_conn_path_state(cp);
WARN_ON(conn_state == RDS_CONN_UP);
if (conn_state != RDS_CONN_CONNECTING && conn_state != RDS_CONN_ERROR)
goto rst_nsk;
if (rs_tcp->t_sock) {
/* Duelling SYN has been handled in rds_tcp_accept_one() */
rds_tcp_reset_callbacks(new_sock, cp);
/* rds_connect_path_complete() marks RDS_CONN_UP */
rds_connect_path_complete(cp, RDS_CONN_RESETTING);
} else {
rds_tcp_set_callbacks(new_sock, cp);
rds_connect_path_complete(cp, RDS_CONN_CONNECTING);
}
new_sock = NULL;
ret = 0;
if (conn->c_npaths == 0)
rds_send_ping(cp->cp_conn, cp->cp_index);
goto out;
rst_nsk:
/* reset the newly returned accept sock and bail.
* It is safe to set linger on new_sock because the RDS connection
* has not been brought up on new_sock, so no RDS-level data could
* be pending on it. By setting linger, we achieve the side-effect
* of avoiding TIME_WAIT state on new_sock.
*/
sock_no_linger(new_sock->sk);
kernel_sock_shutdown(new_sock, SHUT_RDWR);
ret = 0;
out:
if (rs_tcp)
mutex_unlock(&rs_tcp->t_conn_path_lock);
if (new_sock)
sock_release(new_sock);
return ret;
}
void rds_tcp_listen_data_ready(struct sock *sk)
{
void (*ready)(struct sock *sk);
trace_sk_data_ready(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
*
* (*ready)() may be null if we are racing with netns delete, and
* the listen socket is being torn down.
*/
if (sk->sk_state == TCP_LISTEN)
rds_tcp_accept_work(sk);
else
ready = rds_tcp_listen_sock_def_readable(sock_net(sk));
out:
read_unlock_bh(&sk->sk_callback_lock);
if (ready)
ready(sk);
}
struct socket *rds_tcp_listen_init(struct net *net, bool isv6)
{
struct socket *sock = NULL;
struct sockaddr_storage ss;
struct sockaddr_in6 *sin6;
struct sockaddr_in *sin;
int addr_len;
int ret;
ret = sock_create_kern(net, isv6 ? PF_INET6 : PF_INET, SOCK_STREAM,
IPPROTO_TCP, &sock);
if (ret < 0) {
rdsdebug("could not create %s listener socket: %d\n",
isv6 ? "IPv6" : "IPv4", ret);
goto out;
}
sock->sk->sk_reuse = SK_CAN_REUSE;
tcp_sock_set_nodelay(sock->sk);
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);
if (isv6) {
sin6 = (struct sockaddr_in6 *)&ss;
sin6->sin6_family = PF_INET6;
sin6->sin6_addr = in6addr_any;
sin6->sin6_port = (__force u16)htons(RDS_TCP_PORT);
sin6->sin6_scope_id = 0;
sin6->sin6_flowinfo = 0;
addr_len = sizeof(*sin6);
} else {
sin = (struct sockaddr_in *)&ss;
sin->sin_family = PF_INET;
sin->sin_addr.s_addr = INADDR_ANY;
sin->sin_port = (__force u16)htons(RDS_TCP_PORT);
addr_len = sizeof(*sin);
}
ret = kernel_bind(sock, (struct sockaddr *)&ss, addr_len);
if (ret < 0) {
rdsdebug("could not bind %s listener socket: %d\n",
isv6 ? "IPv6" : "IPv4", ret);
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 work_struct *acceptor)
{
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);
flush_work(acceptor);
sock_release(sock);
}
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