net/rds/tcp.c

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