| /* |
| * 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; |
| } |
| |
| /* 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; |
| bool peer_is_smaller = (conn->c_faddr < conn->c_laddr); |
| int npaths = max_t(int, 1, conn->c_npaths); |
| |
| /* for mprds, all paths MUST be initiated by the peer |
| * with the smaller address. |
| */ |
| if (!peer_is_smaller) { |
| /* 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; |
| |
| 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, true); |
| 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 = 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) { |
| /* 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) || |
| !cp->cp_outgoing) { |
| goto rst_nsk; |
| } else { |
| rds_tcp_reset_callbacks(new_sock, cp); |
| cp->cp_outgoing = 0; |
| /* 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; |
| goto out; |
| rst_nsk: |
| /* reset the newly returned accept sock and bail */ |
| 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); |
| |
| 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) |
| { |
| 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 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); |
| } |