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 <linux/module.h>
  37#include <net/tcp.h>
  38
  39#include "rds.h"
  40#include "tcp.h"
  41
  42/* only for info exporting */
  43static DEFINE_SPINLOCK(rds_tcp_tc_list_lock);
  44static LIST_HEAD(rds_tcp_tc_list);
  45static unsigned int rds_tcp_tc_count;
  46
  47/* Track rds_tcp_connection structs so they can be cleaned up */
  48static DEFINE_SPINLOCK(rds_tcp_conn_lock);
  49static LIST_HEAD(rds_tcp_conn_list);
  50
  51static struct kmem_cache *rds_tcp_conn_slab;
  52
  53#define RDS_TCP_DEFAULT_BUFSIZE (128 * 1024)
  54
  55/* doing it this way avoids calling tcp_sk() */
  56void rds_tcp_nonagle(struct socket *sock)
  57{
  58        mm_segment_t oldfs = get_fs();
  59        int val = 1;
  60
  61        set_fs(KERNEL_DS);
  62        sock->ops->setsockopt(sock, SOL_TCP, TCP_NODELAY, (char __user *)&val,
  63                              sizeof(val));
  64        set_fs(oldfs);
  65}
  66
  67void rds_tcp_tune(struct socket *sock)
  68{
  69        struct sock *sk = sock->sk;
  70
  71        rds_tcp_nonagle(sock);
  72
  73        /*
  74         * We're trying to saturate gigabit with the default,
  75         * see svc_sock_setbufsize().
  76         */
  77        lock_sock(sk);
  78        sk->sk_sndbuf = RDS_TCP_DEFAULT_BUFSIZE;
  79        sk->sk_rcvbuf = RDS_TCP_DEFAULT_BUFSIZE;
  80        sk->sk_userlocks |= SOCK_SNDBUF_LOCK|SOCK_RCVBUF_LOCK;
  81        release_sock(sk);
  82}
  83
  84u32 rds_tcp_snd_nxt(struct rds_tcp_connection *tc)
  85{
  86        return tcp_sk(tc->t_sock->sk)->snd_nxt;
  87}
  88
  89u32 rds_tcp_snd_una(struct rds_tcp_connection *tc)
  90{
  91        return tcp_sk(tc->t_sock->sk)->snd_una;
  92}
  93
  94void rds_tcp_restore_callbacks(struct socket *sock,
  95                               struct rds_tcp_connection *tc)
  96{
  97        rdsdebug("restoring sock %p callbacks from tc %p\n", sock, tc);
  98        write_lock_bh(&sock->sk->sk_callback_lock);
  99
 100        /* done under the callback_lock to serialize with write_space */
 101        spin_lock(&rds_tcp_tc_list_lock);
 102        list_del_init(&tc->t_list_item);
 103        rds_tcp_tc_count--;
 104        spin_unlock(&rds_tcp_tc_list_lock);
 105
 106        tc->t_sock = NULL;
 107
 108        sock->sk->sk_write_space = tc->t_orig_write_space;
 109        sock->sk->sk_data_ready = tc->t_orig_data_ready;
 110        sock->sk->sk_state_change = tc->t_orig_state_change;
 111        sock->sk->sk_user_data = NULL;
 112
 113        write_unlock_bh(&sock->sk->sk_callback_lock);
 114}
 115
 116/*
 117 * This is the only path that sets tc->t_sock.  Send and receive trust that
 118 * it is set.  The RDS_CONN_CONNECTED bit protects those paths from being
 119 * called while it isn't set.
 120 */
 121void rds_tcp_set_callbacks(struct socket *sock, struct rds_connection *conn)
 122{
 123        struct rds_tcp_connection *tc = conn->c_transport_data;
 124
 125        rdsdebug("setting sock %p callbacks to tc %p\n", sock, tc);
 126        write_lock_bh(&sock->sk->sk_callback_lock);
 127
 128        /* done under the callback_lock to serialize with write_space */
 129        spin_lock(&rds_tcp_tc_list_lock);
 130        list_add_tail(&tc->t_list_item, &rds_tcp_tc_list);
 131        rds_tcp_tc_count++;
 132        spin_unlock(&rds_tcp_tc_list_lock);
 133
 134        /* accepted sockets need our listen data ready undone */
 135        if (sock->sk->sk_data_ready == rds_tcp_listen_data_ready)
 136                sock->sk->sk_data_ready = sock->sk->sk_user_data;
 137
 138        tc->t_sock = sock;
 139        tc->conn = conn;
 140        tc->t_orig_data_ready = sock->sk->sk_data_ready;
 141        tc->t_orig_write_space = sock->sk->sk_write_space;
 142        tc->t_orig_state_change = sock->sk->sk_state_change;
 143
 144        sock->sk->sk_user_data = conn;
 145        sock->sk->sk_data_ready = rds_tcp_data_ready;
 146        sock->sk->sk_write_space = rds_tcp_write_space;
 147        sock->sk->sk_state_change = rds_tcp_state_change;
 148
 149        write_unlock_bh(&sock->sk->sk_callback_lock);
 150}
 151
 152static void rds_tcp_tc_info(struct socket *sock, unsigned int len,
 153                            struct rds_info_iterator *iter,
 154                            struct rds_info_lengths *lens)
 155{
 156        struct rds_info_tcp_socket tsinfo;
 157        struct rds_tcp_connection *tc;
 158        unsigned long flags;
 159        struct sockaddr_in sin;
 160        int sinlen;
 161
 162        spin_lock_irqsave(&rds_tcp_tc_list_lock, flags);
 163
 164        if (len / sizeof(tsinfo) < rds_tcp_tc_count)
 165                goto out;
 166
 167        list_for_each_entry(tc, &rds_tcp_tc_list, t_list_item) {
 168
 169                sock->ops->getname(sock, (struct sockaddr *)&sin, &sinlen, 0);
 170                tsinfo.local_addr = sin.sin_addr.s_addr;
 171                tsinfo.local_port = sin.sin_port;
 172                sock->ops->getname(sock, (struct sockaddr *)&sin, &sinlen, 1);
 173                tsinfo.peer_addr = sin.sin_addr.s_addr;
 174                tsinfo.peer_port = sin.sin_port;
 175
 176                tsinfo.hdr_rem = tc->t_tinc_hdr_rem;
 177                tsinfo.data_rem = tc->t_tinc_data_rem;
 178                tsinfo.last_sent_nxt = tc->t_last_sent_nxt;
 179                tsinfo.last_expected_una = tc->t_last_expected_una;
 180                tsinfo.last_seen_una = tc->t_last_seen_una;
 181
 182                rds_info_copy(iter, &tsinfo, sizeof(tsinfo));
 183        }
 184
 185out:
 186        lens->nr = rds_tcp_tc_count;
 187        lens->each = sizeof(tsinfo);
 188
 189        spin_unlock_irqrestore(&rds_tcp_tc_list_lock, flags);
 190}
 191
 192static int rds_tcp_laddr_check(__be32 addr)
 193{
 194        if (inet_addr_type(&init_net, addr) == RTN_LOCAL)
 195                return 0;
 196        return -EADDRNOTAVAIL;
 197}
 198
 199static int rds_tcp_conn_alloc(struct rds_connection *conn, gfp_t gfp)
 200{
 201        struct rds_tcp_connection *tc;
 202
 203        tc = kmem_cache_alloc(rds_tcp_conn_slab, gfp);
 204        if (!tc)
 205                return -ENOMEM;
 206
 207        tc->t_sock = NULL;
 208        tc->t_tinc = NULL;
 209        tc->t_tinc_hdr_rem = sizeof(struct rds_header);
 210        tc->t_tinc_data_rem = 0;
 211
 212        conn->c_transport_data = tc;
 213
 214        spin_lock_irq(&rds_tcp_conn_lock);
 215        list_add_tail(&tc->t_tcp_node, &rds_tcp_conn_list);
 216        spin_unlock_irq(&rds_tcp_conn_lock);
 217
 218        rdsdebug("alloced tc %p\n", conn->c_transport_data);
 219        return 0;
 220}
 221
 222static void rds_tcp_conn_free(void *arg)
 223{
 224        struct rds_tcp_connection *tc = arg;
 225        unsigned long flags;
 226        rdsdebug("freeing tc %p\n", tc);
 227
 228        spin_lock_irqsave(&rds_tcp_conn_lock, flags);
 229        list_del(&tc->t_tcp_node);
 230        spin_unlock_irqrestore(&rds_tcp_conn_lock, flags);
 231
 232        kmem_cache_free(rds_tcp_conn_slab, tc);
 233}
 234
 235static void rds_tcp_destroy_conns(void)
 236{
 237        struct rds_tcp_connection *tc, *_tc;
 238        LIST_HEAD(tmp_list);
 239
 240        /* avoid calling conn_destroy with irqs off */
 241        spin_lock_irq(&rds_tcp_conn_lock);
 242        list_splice(&rds_tcp_conn_list, &tmp_list);
 243        INIT_LIST_HEAD(&rds_tcp_conn_list);
 244        spin_unlock_irq(&rds_tcp_conn_lock);
 245
 246        list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node) {
 247                if (tc->conn->c_passive)
 248                        rds_conn_destroy(tc->conn->c_passive);
 249                rds_conn_destroy(tc->conn);
 250        }
 251}
 252
 253static void rds_tcp_exit(void)
 254{
 255        rds_info_deregister_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);
 256        rds_tcp_listen_stop();
 257        rds_tcp_destroy_conns();
 258        rds_trans_unregister(&rds_tcp_transport);
 259        rds_tcp_recv_exit();
 260        kmem_cache_destroy(rds_tcp_conn_slab);
 261}
 262module_exit(rds_tcp_exit);
 263
 264struct rds_transport rds_tcp_transport = {
 265        .laddr_check            = rds_tcp_laddr_check,
 266        .xmit_prepare           = rds_tcp_xmit_prepare,
 267        .xmit_complete          = rds_tcp_xmit_complete,
 268        .xmit                   = rds_tcp_xmit,
 269        .recv                   = rds_tcp_recv,
 270        .conn_alloc             = rds_tcp_conn_alloc,
 271        .conn_free              = rds_tcp_conn_free,
 272        .conn_connect           = rds_tcp_conn_connect,
 273        .conn_shutdown          = rds_tcp_conn_shutdown,
 274        .inc_copy_to_user       = rds_tcp_inc_copy_to_user,
 275        .inc_free               = rds_tcp_inc_free,
 276        .stats_info_copy        = rds_tcp_stats_info_copy,
 277        .exit                   = rds_tcp_exit,
 278        .t_owner                = THIS_MODULE,
 279        .t_name                 = "tcp",
 280        .t_type                 = RDS_TRANS_TCP,
 281        .t_prefer_loopback      = 1,
 282};
 283
 284static int rds_tcp_init(void)
 285{
 286        int ret;
 287
 288        rds_tcp_conn_slab = kmem_cache_create("rds_tcp_connection",
 289                                              sizeof(struct rds_tcp_connection),
 290                                              0, 0, NULL);
 291        if (!rds_tcp_conn_slab) {
 292                ret = -ENOMEM;
 293                goto out;
 294        }
 295
 296        ret = rds_tcp_recv_init();
 297        if (ret)
 298                goto out_slab;
 299
 300        ret = rds_trans_register(&rds_tcp_transport);
 301        if (ret)
 302                goto out_recv;
 303
 304        ret = rds_tcp_listen_init();
 305        if (ret)
 306                goto out_register;
 307
 308        rds_info_register_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);
 309
 310        goto out;
 311
 312out_register:
 313        rds_trans_unregister(&rds_tcp_transport);
 314out_recv:
 315        rds_tcp_recv_exit();
 316out_slab:
 317        kmem_cache_destroy(rds_tcp_conn_slab);
 318out:
 319        return ret;
 320}
 321module_init(rds_tcp_init);
 322
 323MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
 324MODULE_DESCRIPTION("RDS: TCP transport");
 325MODULE_LICENSE("Dual BSD/GPL");
 326
 327
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