diff options
Diffstat (limited to 'net/rds/tcp.c')
| -rw-r--r-- | net/rds/tcp.c | 450 |
1 files changed, 450 insertions, 0 deletions
diff --git a/net/rds/tcp.c b/net/rds/tcp.c new file mode 100644 index 000000000000..465756fe7958 --- /dev/null +++ b/net/rds/tcp.c @@ -0,0 +1,450 @@ +/* + * 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/slab.h> +#include <linux/in.h> +#include <linux/module.h> +#include <net/tcp.h> +#include <net/net_namespace.h> +#include <net/netns/generic.h> +#include <net/tcp.h> + +#include "rds.h" +#include "tcp.h" + +/* only for info exporting */ +static DEFINE_SPINLOCK(rds_tcp_tc_list_lock); +static LIST_HEAD(rds_tcp_tc_list); +static unsigned int rds_tcp_tc_count; + +/* Track rds_tcp_connection structs so they can be cleaned up */ +static DEFINE_SPINLOCK(rds_tcp_conn_lock); +static LIST_HEAD(rds_tcp_conn_list); + +static struct kmem_cache *rds_tcp_conn_slab; + +#define RDS_TCP_DEFAULT_BUFSIZE (128 * 1024) + +/* doing it this way avoids calling tcp_sk() */ +void rds_tcp_nonagle(struct socket *sock) +{ + mm_segment_t oldfs = get_fs(); + int val = 1; + + set_fs(KERNEL_DS); + sock->ops->setsockopt(sock, SOL_TCP, TCP_NODELAY, (char __user *)&val, + sizeof(val)); + set_fs(oldfs); +} + +/* All module specific customizations to the RDS-TCP socket should be done in + * rds_tcp_tune() and applied after socket creation. In general these + * customizations should be tunable via module_param() + */ +void rds_tcp_tune(struct socket *sock) +{ + rds_tcp_nonagle(sock); +} + +u32 rds_tcp_snd_nxt(struct rds_tcp_connection *tc) +{ + return tcp_sk(tc->t_sock->sk)->snd_nxt; +} + +u32 rds_tcp_snd_una(struct rds_tcp_connection *tc) +{ + return tcp_sk(tc->t_sock->sk)->snd_una; +} + +void rds_tcp_restore_callbacks(struct socket *sock, + struct rds_tcp_connection *tc) +{ + rdsdebug("restoring sock %p callbacks from tc %p\n", sock, tc); + write_lock_bh(&sock->sk->sk_callback_lock); + + /* done under the callback_lock to serialize with write_space */ + spin_lock(&rds_tcp_tc_list_lock); + list_del_init(&tc->t_list_item); + rds_tcp_tc_count--; + spin_unlock(&rds_tcp_tc_list_lock); + + tc->t_sock = NULL; + + sock->sk->sk_write_space = tc->t_orig_write_space; + sock->sk->sk_data_ready = tc->t_orig_data_ready; + sock->sk->sk_state_change = tc->t_orig_state_change; + sock->sk->sk_user_data = NULL; + + write_unlock_bh(&sock->sk->sk_callback_lock); +} + +/* + * This is the only path that sets tc->t_sock. Send and receive trust that + * it is set. The RDS_CONN_UP bit protects those paths from being + * called while it isn't set. + */ +void rds_tcp_set_callbacks(struct socket *sock, struct rds_connection *conn) +{ + struct rds_tcp_connection *tc = conn->c_transport_data; + + rdsdebug("setting sock %p callbacks to tc %p\n", sock, tc); + write_lock_bh(&sock->sk->sk_callback_lock); + + /* done under the callback_lock to serialize with write_space */ + spin_lock(&rds_tcp_tc_list_lock); + list_add_tail(&tc->t_list_item, &rds_tcp_tc_list); + rds_tcp_tc_count++; + spin_unlock(&rds_tcp_tc_list_lock); + + /* accepted sockets need our listen data ready undone */ + if (sock->sk->sk_data_ready == rds_tcp_listen_data_ready) + sock->sk->sk_data_ready = sock->sk->sk_user_data; + + tc->t_sock = sock; + tc->conn = conn; + tc->t_orig_data_ready = sock->sk->sk_data_ready; + tc->t_orig_write_space = sock->sk->sk_write_space; + tc->t_orig_state_change = sock->sk->sk_state_change; + + sock->sk->sk_user_data = conn; + sock->sk->sk_data_ready = rds_tcp_data_ready; + sock->sk->sk_write_space = rds_tcp_write_space; + sock->sk->sk_state_change = rds_tcp_state_change; + + write_unlock_bh(&sock->sk->sk_callback_lock); +} + +static void rds_tcp_tc_info(struct socket *sock, unsigned int len, + struct rds_info_iterator *iter, + struct rds_info_lengths *lens) +{ + struct rds_info_tcp_socket tsinfo; + struct rds_tcp_connection *tc; + unsigned long flags; + struct sockaddr_in sin; + int sinlen; + + spin_lock_irqsave(&rds_tcp_tc_list_lock, flags); + + if (len / sizeof(tsinfo) < rds_tcp_tc_count) + goto out; + + list_for_each_entry(tc, &rds_tcp_tc_list, t_list_item) { + + sock->ops->getname(sock, (struct sockaddr *)&sin, &sinlen, 0); + tsinfo.local_addr = sin.sin_addr.s_addr; + tsinfo.local_port = sin.sin_port; + sock->ops->getname(sock, (struct sockaddr *)&sin, &sinlen, 1); + tsinfo.peer_addr = sin.sin_addr.s_addr; + tsinfo.peer_port = sin.sin_port; + + tsinfo.hdr_rem = tc->t_tinc_hdr_rem; + tsinfo.data_rem = tc->t_tinc_data_rem; + tsinfo.last_sent_nxt = tc->t_last_sent_nxt; + tsinfo.last_expected_una = tc->t_last_expected_una; + tsinfo.last_seen_una = tc->t_last_seen_una; + + rds_info_copy(iter, &tsinfo, sizeof(tsinfo)); + } + +out: + lens->nr = rds_tcp_tc_count; + lens->each = sizeof(tsinfo); + + spin_unlock_irqrestore(&rds_tcp_tc_list_lock, flags); +} + +static int rds_tcp_laddr_check(struct net *net, __be32 addr) +{ + if (inet_addr_type(net, addr) == RTN_LOCAL) + return 0; + return -EADDRNOTAVAIL; +} + +static int rds_tcp_conn_alloc(struct rds_connection *conn, gfp_t gfp) +{ + struct rds_tcp_connection *tc; + + tc = kmem_cache_alloc(rds_tcp_conn_slab, gfp); + if (!tc) + return -ENOMEM; + + tc->t_sock = NULL; + tc->t_tinc = NULL; + tc->t_tinc_hdr_rem = sizeof(struct rds_header); + tc->t_tinc_data_rem = 0; + + conn->c_transport_data = tc; + + spin_lock_irq(&rds_tcp_conn_lock); + list_add_tail(&tc->t_tcp_node, &rds_tcp_conn_list); + spin_unlock_irq(&rds_tcp_conn_lock); + + rdsdebug("alloced tc %p\n", conn->c_transport_data); + return 0; +} + +static void rds_tcp_conn_free(void *arg) +{ + struct rds_tcp_connection *tc = arg; + unsigned long flags; + rdsdebug("freeing tc %p\n", tc); + + spin_lock_irqsave(&rds_tcp_conn_lock, flags); + list_del(&tc->t_tcp_node); + spin_unlock_irqrestore(&rds_tcp_conn_lock, flags); + + kmem_cache_free(rds_tcp_conn_slab, tc); +} + +static void rds_tcp_destroy_conns(void) +{ + struct rds_tcp_connection *tc, *_tc; + LIST_HEAD(tmp_list); + + /* avoid calling conn_destroy with irqs off */ + spin_lock_irq(&rds_tcp_conn_lock); + list_splice(&rds_tcp_conn_list, &tmp_list); + INIT_LIST_HEAD(&rds_tcp_conn_list); + spin_unlock_irq(&rds_tcp_conn_lock); + + list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node) { + if (tc->conn->c_passive) + rds_conn_destroy(tc->conn->c_passive); + rds_conn_destroy(tc->conn); + } +} + +static void rds_tcp_exit(void); + +struct rds_transport rds_tcp_transport = { + .laddr_check = rds_tcp_laddr_check, + .xmit_prepare = rds_tcp_xmit_prepare, + .xmit_complete = rds_tcp_xmit_complete, + .xmit = rds_tcp_xmit, + .recv = rds_tcp_recv, + .conn_alloc = rds_tcp_conn_alloc, + .conn_free = rds_tcp_conn_free, + .conn_connect = rds_tcp_conn_connect, + .conn_shutdown = rds_tcp_conn_shutdown, + .inc_copy_to_user = rds_tcp_inc_copy_to_user, + .inc_free = rds_tcp_inc_free, + .stats_info_copy = rds_tcp_stats_info_copy, + .exit = rds_tcp_exit, + .t_owner = THIS_MODULE, + .t_name = "tcp", + .t_type = RDS_TRANS_TCP, + .t_prefer_loopback = 1, +}; + +static int rds_tcp_netid; + +/* per-network namespace private data for this module */ +struct rds_tcp_net { + struct socket *rds_tcp_listen_sock; + struct work_struct rds_tcp_accept_w; +}; + +static void rds_tcp_accept_worker(struct work_struct *work) +{ + struct rds_tcp_net *rtn = container_of(work, + struct rds_tcp_net, + rds_tcp_accept_w); + + while (rds_tcp_accept_one(rtn->rds_tcp_listen_sock) == 0) + cond_resched(); +} + +void rds_tcp_accept_work(struct sock *sk) +{ + struct net *net = sock_net(sk); + struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid); + + queue_work(rds_wq, &rtn->rds_tcp_accept_w); +} + +static __net_init int rds_tcp_init_net(struct net *net) +{ + struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid); + + rtn->rds_tcp_listen_sock = rds_tcp_listen_init(net); + if (!rtn->rds_tcp_listen_sock) { + pr_warn("could not set up listen sock\n"); + return -EAFNOSUPPORT; + } + INIT_WORK(&rtn->rds_tcp_accept_w, rds_tcp_accept_worker); + return 0; +} + +static void __net_exit rds_tcp_exit_net(struct net *net) +{ + struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid); + + /* If rds_tcp_exit_net() is called as a result of netns deletion, + * the rds_tcp_kill_sock() device notifier would already have cleaned + * up the listen socket, thus there is no work to do in this function. + * + * If rds_tcp_exit_net() is called as a result of module unload, + * i.e., due to rds_tcp_exit() -> unregister_pernet_subsys(), then + * we do need to clean up the listen socket here. + */ + if (rtn->rds_tcp_listen_sock) { + rds_tcp_listen_stop(rtn->rds_tcp_listen_sock); + rtn->rds_tcp_listen_sock = NULL; + flush_work(&rtn->rds_tcp_accept_w); + } +} + +static struct pernet_operations rds_tcp_net_ops = { + .init = rds_tcp_init_net, + .exit = rds_tcp_exit_net, + .id = &rds_tcp_netid, + .size = sizeof(struct rds_tcp_net), +}; + +static void rds_tcp_kill_sock(struct net *net) +{ + struct rds_tcp_connection *tc, *_tc; + struct sock *sk; + LIST_HEAD(tmp_list); + struct rds_tcp_net *rtn = net_generic(net, rds_tcp_netid); + + rds_tcp_listen_stop(rtn->rds_tcp_listen_sock); + rtn->rds_tcp_listen_sock = NULL; + flush_work(&rtn->rds_tcp_accept_w); + spin_lock_irq(&rds_tcp_conn_lock); + list_for_each_entry_safe(tc, _tc, &rds_tcp_conn_list, t_tcp_node) { + struct net *c_net = read_pnet(&tc->conn->c_net); + + if (net != c_net) + continue; + list_move_tail(&tc->t_tcp_node, &tmp_list); + } + spin_unlock_irq(&rds_tcp_conn_lock); + list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node) { + if (tc->t_sock) { + sk = tc->t_sock->sk; + sk->sk_prot->disconnect(sk, 0); + tcp_done(sk); + } + if (tc->conn->c_passive) + rds_conn_destroy(tc->conn->c_passive); + rds_conn_destroy(tc->conn); + } +} + +static int rds_tcp_dev_event(struct notifier_block *this, + unsigned long event, void *ptr) +{ + struct net_device *dev = netdev_notifier_info_to_dev(ptr); + + /* rds-tcp registers as a pernet subys, so the ->exit will only + * get invoked after network acitivity has quiesced. We need to + * clean up all sockets to quiesce network activity, and use + * the unregistration of the per-net loopback device as a trigger + * to start that cleanup. + */ + if (event == NETDEV_UNREGISTER_FINAL && + dev->ifindex == LOOPBACK_IFINDEX) + rds_tcp_kill_sock(dev_net(dev)); + + return NOTIFY_DONE; +} + +static struct notifier_block rds_tcp_dev_notifier = { + .notifier_call = rds_tcp_dev_event, + .priority = -10, /* must be called after other network notifiers */ +}; + +static void rds_tcp_exit(void) +{ + rds_info_deregister_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info); + unregister_pernet_subsys(&rds_tcp_net_ops); + if (unregister_netdevice_notifier(&rds_tcp_dev_notifier)) + pr_warn("could not unregister rds_tcp_dev_notifier\n"); + rds_tcp_destroy_conns(); + rds_trans_unregister(&rds_tcp_transport); + rds_tcp_recv_exit(); + kmem_cache_destroy(rds_tcp_conn_slab); +} +module_exit(rds_tcp_exit); + +static int rds_tcp_init(void) +{ + int ret; + + rds_tcp_conn_slab = kmem_cache_create("rds_tcp_connection", + sizeof(struct rds_tcp_connection), + 0, 0, NULL); + if (!rds_tcp_conn_slab) { + ret = -ENOMEM; + goto out; + } + + ret = register_netdevice_notifier(&rds_tcp_dev_notifier); + if (ret) { + pr_warn("could not register rds_tcp_dev_notifier\n"); + goto out; + } + + ret = register_pernet_subsys(&rds_tcp_net_ops); + if (ret) + goto out_slab; + + ret = rds_tcp_recv_init(); + if (ret) + goto out_pernet; + + ret = rds_trans_register(&rds_tcp_transport); + if (ret) + goto out_recv; + + rds_info_register_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info); + + goto out; + +out_recv: + rds_tcp_recv_exit(); +out_pernet: + unregister_pernet_subsys(&rds_tcp_net_ops); +out_slab: + kmem_cache_destroy(rds_tcp_conn_slab); +out: + return ret; +} +module_init(rds_tcp_init); + +MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>"); +MODULE_DESCRIPTION("RDS: TCP transport"); +MODULE_LICENSE("Dual BSD/GPL"); + |