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/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 */
  42 static DEFINE_SPINLOCK(rds_tcp_tc_list_lock);
  43 static LIST_HEAD(rds_tcp_tc_list);
  44 static unsigned int rds_tcp_tc_count;
  45
  46 /* Track rds_tcp_connection structs so they can be cleaned up */
  47 static DEFINE_SPINLOCK(rds_tcp_conn_lock);
  48 static LIST_HEAD(rds_tcp_conn_list);
  49
  50 static 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() */
  55 void 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
  66 void 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
  83 u32 rds_tcp_snd_nxt(struct rds_tcp_connection *tc)
  84 {
  85         return tcp_sk(tc->t_sock->sk)->snd_nxt;
  86 }
  87
  88 u32 rds_tcp_snd_una(struct rds_tcp_connection *tc)
  89 {
  90         return tcp_sk(tc->t_sock->sk)->snd_una;
  91 }
  92
  93 void 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  */
 120 void 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
 151 static 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
 184 out:
 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
 191 static 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
 198 static 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)
 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
 221 static void rds_tcp_conn_free(void *arg)
 222 {
 223         struct rds_tcp_connection *tc = arg;
 224         unsigned long flags;
 225         rdsdebug("freeing tc %p\n", tc);
 226
 227         spin_lock_irqsave(&rds_tcp_conn_lock, flags);
 228         list_del(&tc->t_tcp_node);
 229         spin_unlock_irqrestore(&rds_tcp_conn_lock, flags);
 230
 231         kmem_cache_free(rds_tcp_conn_slab, tc);
 232 }
 233
 234 static void rds_tcp_destroy_conns(void)
 235 {
 236         struct rds_tcp_connection *tc, *_tc;
 237         LIST_HEAD(tmp_list);
 238
 239         /* avoid calling conn_destroy with irqs off */
 240         spin_lock_irq(&rds_tcp_conn_lock);
 241         list_splice(&rds_tcp_conn_list, &tmp_list);
 242         INIT_LIST_HEAD(&rds_tcp_conn_list);
 243         spin_unlock_irq(&rds_tcp_conn_lock);
 244
 245         list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node) {
 246                 if (tc->conn->c_passive)
 247                         rds_conn_destroy(tc->conn->c_passive);
 248                 rds_conn_destroy(tc->conn);
 249         }
 250 }
 251
 252 static void rds_tcp_exit(void)
 253 {
 254         rds_info_deregister_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);
 255         rds_tcp_listen_stop();
 256         rds_tcp_destroy_conns();
 257         rds_trans_unregister(&rds_tcp_transport);
 258         rds_tcp_recv_exit();
 259         kmem_cache_destroy(rds_tcp_conn_slab);
 260 }
 261 module_exit(rds_tcp_exit);
 262
 263 struct rds_transport rds_tcp_transport = {
 264         .laddr_check            = rds_tcp_laddr_check,
 265         .xmit_prepare           = rds_tcp_xmit_prepare,
 266         .xmit_complete          = rds_tcp_xmit_complete,
 267         .xmit                   = rds_tcp_xmit,
 268         .recv                   = rds_tcp_recv,
 269         .conn_alloc             = rds_tcp_conn_alloc,
 270         .conn_free              = rds_tcp_conn_free,
 271         .conn_connect           = rds_tcp_conn_connect,
 272         .conn_shutdown          = rds_tcp_conn_shutdown,
 273         .inc_copy_to_user       = rds_tcp_inc_copy_to_user,
 274         .inc_free               = rds_tcp_inc_free,
 275         .stats_info_copy        = rds_tcp_stats_info_copy,
 276         .exit                   = rds_tcp_exit,
 277         .t_owner                = THIS_MODULE,
 278         .t_name                 = "tcp",
 279         .t_type                 = RDS_TRANS_TCP,
 280         .t_prefer_loopback      = 1,
 281 };
 282
 283 static int rds_tcp_init(void)
 284 {
 285         int ret;
 286
 287         rds_tcp_conn_slab = kmem_cache_create("rds_tcp_connection",
 288                                               sizeof(struct rds_tcp_connection),
 289                                               0, 0, NULL);
 290         if (!rds_tcp_conn_slab) {
 291                 ret = -ENOMEM;
 292                 goto out;
 293         }
 294
 295         ret = rds_tcp_recv_init();
 296         if (ret)
 297                 goto out_slab;
 298
 299         ret = rds_trans_register(&rds_tcp_transport);
 300         if (ret)
 301                 goto out_recv;
 302
 303         ret = rds_tcp_listen_init();
 304         if (ret)
 305                 goto out_register;
 306
 307         rds_info_register_func(RDS_INFO_TCP_SOCKETS, rds_tcp_tc_info);
 308
 309         goto out;
 310
 311 out_register:
 312         rds_trans_unregister(&rds_tcp_transport);
 313 out_recv:
 314         rds_tcp_recv_exit();
 315 out_slab:
 316         kmem_cache_destroy(rds_tcp_conn_slab);
 317 out:
 318         return ret;
 319 }
 320 module_init(rds_tcp_init);
 321
 322 MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
 323 MODULE_DESCRIPTION("RDS: TCP transport");
 324 MODULE_LICENSE("Dual BSD/GPL");
 325