linux/net/rds/tcp.c
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   1/*
   2 * Copyright (c) 2006 Oracle.  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/slab.h>
  35#include <linux/in.h>
  36#include <net/tcp.h>
  37
  38#include "rds.h"
  39#include "tcp.h"
  40
  41/* only for info exporting */
  42static DEFINE_SPINLOCK(rds_tcp_tc_list_lock);
  43static LIST_HEAD(rds_tcp_tc_list);
  44unsigned int rds_tcp_tc_count;
  45
  46/* Track rds_tcp_connection structs so they can be cleaned up */
  47static DEFINE_SPINLOCK(rds_tcp_conn_lock);
  48static LIST_HEAD(rds_tcp_conn_list);
  49
  50static struct kmem_cache *rds_tcp_conn_slab;
  51
  52#define RDS_TCP_DEFAULT_BUFSIZE (128 * 1024)
  53
  54/* doing it this way avoids calling tcp_sk() */
  55void rds_tcp_nonagle(struct socket *sock)
  56{
  57        mm_segment_t oldfs = get_fs();
  58        int val = 1;
  59
  60        set_fs(KERNEL_DS);
  61        sock->ops->setsockopt(sock, SOL_TCP, TCP_NODELAY, (char __user *)&val,
  62                              sizeof(val));
  63        set_fs(oldfs);
  64}
  65
  66void rds_tcp_tune(struct socket *sock)
  67{
  68        struct sock *sk = sock->sk;
  69
  70        rds_tcp_nonagle(sock);
  71
  72        /*
  73         * We're trying to saturate gigabit with the default,
  74         * see svc_sock_setbufsize().
  75         */
  76        lock_sock(sk);
  77        sk->sk_sndbuf = RDS_TCP_DEFAULT_BUFSIZE;
  78        sk->sk_rcvbuf = RDS_TCP_DEFAULT_BUFSIZE;
  79        sk->sk_userlocks |= SOCK_SNDBUF_LOCK|SOCK_RCVBUF_LOCK;
  80        release_sock(sk);
  81}
  82
  83u32 rds_tcp_snd_nxt(struct rds_tcp_connection *tc)
  84{
  85        return tcp_sk(tc->t_sock->sk)->snd_nxt;
  86}
  87
  88u32 rds_tcp_snd_una(struct rds_tcp_connection *tc)
  89{
  90        return tcp_sk(tc->t_sock->sk)->snd_una;
  91}
  92
  93void rds_tcp_restore_callbacks(struct socket *sock,
  94                               struct rds_tcp_connection *tc)
  95{
  96        rdsdebug("restoring sock %p callbacks from tc %p\n", sock, tc);
  97        write_lock_bh(&sock->sk->sk_callback_lock);
  98
  99        /* done under the callback_lock to serialize with write_space */
 100        spin_lock(&rds_tcp_tc_list_lock);
 101        list_del_init(&tc->t_list_item);
 102        rds_tcp_tc_count--;
 103        spin_unlock(&rds_tcp_tc_list_lock);
 104
 105        tc->t_sock = NULL;
 106
 107        sock->sk->sk_write_space = tc->t_orig_write_space;
 108        sock->sk->sk_data_ready = tc->t_orig_data_ready;
 109        sock->sk->sk_state_change = tc->t_orig_state_change;
 110        sock->sk->sk_user_data = NULL;
 111
 112        write_unlock_bh(&sock->sk->sk_callback_lock);
 113}
 114
 115/*
 116 * This is the only path that sets tc->t_sock.  Send and receive trust that
 117 * it is set.  The RDS_CONN_CONNECTED bit protects those paths from being
 118 * called while it isn't set.
 119 */
 120void rds_tcp_set_callbacks(struct socket *sock, struct rds_connection *conn)
 121{
 122        struct rds_tcp_connection *tc = conn->c_transport_data;
 123
 124        rdsdebug("setting sock %p callbacks to tc %p\n", sock, tc);
 125        write_lock_bh(&sock->sk->sk_callback_lock);
 126
 127        /* done under the callback_lock to serialize with write_space */
 128        spin_lock(&rds_tcp_tc_list_lock);
 129        list_add_tail(&tc->t_list_item, &rds_tcp_tc_list);
 130        rds_tcp_tc_count++;
 131        spin_unlock(&rds_tcp_tc_list_lock);
 132
 133        /* accepted sockets need our listen data ready undone */
 134        if (sock->sk->sk_data_ready == rds_tcp_listen_data_ready)
 135                sock->sk->sk_data_ready = sock->sk->sk_user_data;
 136
 137        tc->t_sock = sock;
 138        tc->conn = conn;
 139        tc->t_orig_data_ready = sock->sk->sk_data_ready;
 140        tc->t_orig_write_space = sock->sk->sk_write_space;
 141        tc->t_orig_state_change = sock->sk->sk_state_change;
 142
 143        sock->sk->sk_user_data = conn;
 144        sock->sk->sk_data_ready = rds_tcp_data_ready;
 145        sock->sk->sk_write_space = rds_tcp_write_space;
 146        sock->sk->sk_state_change = rds_tcp_state_change;
 147
 148        write_unlock_bh(&sock->sk->sk_callback_lock);
 149}
 150
 151static void rds_tcp_tc_info(struct socket *sock, unsigned int len,
 152                            struct rds_info_iterator *iter,
 153                            struct rds_info_lengths *lens)
 154{
 155        struct rds_info_tcp_socket tsinfo;
 156        struct rds_tcp_connection *tc;
 157        unsigned long flags;
 158        struct sockaddr_in sin;
 159        int sinlen;
 160
 161        spin_lock_irqsave(&rds_tcp_tc_list_lock, flags);
 162
 163        if (len / sizeof(tsinfo) < rds_tcp_tc_count)
 164                goto out;
 165
 166        list_for_each_entry(tc, &rds_tcp_tc_list, t_list_item) {
 167
 168                sock->ops->getname(sock, (struct sockaddr *)&sin, &sinlen, 0);
 169                tsinfo.local_addr = sin.sin_addr.s_addr;
 170                tsinfo.local_port = sin.sin_port;
 171                sock->ops->getname(sock, (struct sockaddr *)&sin, &sinlen, 1);
 172                tsinfo.peer_addr = sin.sin_addr.s_addr;
 173                tsinfo.peer_port = sin.sin_port;
 174
 175                tsinfo.hdr_rem = tc->t_tinc_hdr_rem;
 176                tsinfo.data_rem = tc->t_tinc_data_rem;
 177                tsinfo.last_sent_nxt = tc->t_last_sent_nxt;
 178                tsinfo.last_expected_una = tc->t_last_expected_una;
 179                tsinfo.last_seen_una = tc->t_last_seen_una;
 180
 181                rds_info_copy(iter, &tsinfo, sizeof(tsinfo));
 182        }
 183
 184out:
 185        lens->nr = rds_tcp_tc_count;
 186        lens->each = sizeof(tsinfo);
 187
 188        spin_unlock_irqrestore(&rds_tcp_tc_list_lock, flags);
 189}
 190
 191static int rds_tcp_laddr_check(__be32 addr)
 192{
 193        if (inet_addr_type(&init_net, addr) == RTN_LOCAL)
 194                return 0;
 195        return -EADDRNOTAVAIL;
 196}
 197
 198static int rds_tcp_conn_alloc(struct rds_connection *conn, gfp_t gfp)
 199{
 200        struct rds_tcp_connection *tc;
 201
 202        tc = kmem_cache_alloc(rds_tcp_conn_slab, gfp);
 203        if (tc == NULL)
 204                return -ENOMEM;
 205
 206        tc->t_sock = NULL;
 207        tc->t_tinc = NULL;
 208        tc->t_tinc_hdr_rem = sizeof(struct rds_header);
 209        tc->t_tinc_data_rem = 0;
 210
 211        conn->c_transport_data = tc;
 212
 213        spin_lock_irq(&rds_tcp_conn_lock);
 214        list_add_tail(&tc->t_tcp_node, &rds_tcp_conn_list);
 215        spin_unlock_irq(&rds_tcp_conn_lock);
 216
 217        rdsdebug("alloced tc %p\n", conn->c_transport_data);
 218        return 0;
 219}
 220
 221static void rds_tcp_conn_free(void *arg)
 222{
 223        struct rds_tcp_connection *tc = arg;
 224        rdsdebug("freeing tc %p\n", tc);
 225        kmem_cache_free(rds_tcp_conn_slab, tc);
 226}
 227
 228static void rds_tcp_destroy_conns(void)
 229{
 230        struct rds_tcp_connection *tc, *_tc;
 231        LIST_HEAD(tmp_list);
 232
 233        /* avoid calling conn_destroy with irqs off */
 234        spin_lock_irq(&rds_tcp_conn_lock);
 235        list_splice(&rds_tcp_conn_list, &tmp_list);
 236        INIT_LIST_HEAD(&rds_tcp_conn_list);
 237        spin_unlock_irq(&rds_tcp_conn_lock);
 238
 239        list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node) {
 240                if (tc->conn->c_passive)
 241                        rds_conn_destroy(tc->conn->c_passive);
 242                rds_conn_destroy(tc->conn);
 243        }
 244}
 245
 246void rds_tcp_exit(void)
 247{
 248        rds_info_deregister_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);
 249        rds_tcp_listen_stop();
 250        rds_tcp_destroy_conns();
 251        rds_trans_unregister(&rds_tcp_transport);
 252        rds_tcp_recv_exit();
 253        kmem_cache_destroy(rds_tcp_conn_slab);
 254}
 255module_exit(rds_tcp_exit);
 256
 257struct rds_transport rds_tcp_transport = {
 258        .laddr_check            = rds_tcp_laddr_check,
 259        .xmit_prepare           = rds_tcp_xmit_prepare,
 260        .xmit_complete          = rds_tcp_xmit_complete,
 261        .xmit_cong_map          = rds_tcp_xmit_cong_map,
 262        .xmit                   = rds_tcp_xmit,
 263        .recv                   = rds_tcp_recv,
 264        .conn_alloc             = rds_tcp_conn_alloc,
 265        .conn_free              = rds_tcp_conn_free,
 266        .conn_connect           = rds_tcp_conn_connect,
 267        .conn_shutdown          = rds_tcp_conn_shutdown,
 268        .inc_copy_to_user       = rds_tcp_inc_copy_to_user,
 269        .inc_purge              = rds_tcp_inc_purge,
 270        .inc_free               = rds_tcp_inc_free,
 271        .stats_info_copy        = rds_tcp_stats_info_copy,
 272        .exit                   = rds_tcp_exit,
 273        .t_owner                = THIS_MODULE,
 274        .t_name                 = "tcp",
 275        .t_type                 = RDS_TRANS_TCP,
 276        .t_prefer_loopback      = 1,
 277};
 278
 279int __init rds_tcp_init(void)
 280{
 281        int ret;
 282
 283        rds_tcp_conn_slab = kmem_cache_create("rds_tcp_connection",
 284                                              sizeof(struct rds_tcp_connection),
 285                                              0, 0, NULL);
 286        if (rds_tcp_conn_slab == NULL) {
 287                ret = -ENOMEM;
 288                goto out;
 289        }
 290
 291        ret = rds_tcp_recv_init();
 292        if (ret)
 293                goto out_slab;
 294
 295        ret = rds_trans_register(&rds_tcp_transport);
 296        if (ret)
 297                goto out_recv;
 298
 299        ret = rds_tcp_listen_init();
 300        if (ret)
 301                goto out_register;
 302
 303        rds_info_register_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);
 304
 305        goto out;
 306
 307out_register:
 308        rds_trans_unregister(&rds_tcp_transport);
 309out_recv:
 310        rds_tcp_recv_exit();
 311out_slab:
 312        kmem_cache_destroy(rds_tcp_conn_slab);
 313out:
 314        return ret;
 315}
 316module_init(rds_tcp_init);
 317
 318MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
 319MODULE_DESCRIPTION("RDS: TCP transport");
 320MODULE_LICENSE("Dual BSD/GPL");
 321
 322