net/rds/af_rds.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/module.h>
  34 #include <linux/errno.h>
  35 #include <linux/kernel.h>
  36 #include <linux/gfp.h>
  37 #include <linux/in.h>
  38 #include <linux/poll.h>
  39 #include <net/sock.h>
  40
  41 #include "rds.h"
  42
  43 /* this is just used for stats gathering :/ */
  44 static DEFINE_SPINLOCK(rds_sock_lock);
  45 static unsigned long rds_sock_count;
  46 static LIST_HEAD(rds_sock_list);
  47 DECLARE_WAIT_QUEUE_HEAD(rds_poll_waitq);
  48
  49 /*
  50  * This is called as the final descriptor referencing this socket is closed.
  51  * We have to unbind the socket so that another socket can be bound to the
  52  * address it was using.
  53  *
  54  * We have to be careful about racing with the incoming path.  sock_orphan()
  55  * sets SOCK_DEAD and we use that as an indicator to the rx path that new
  56  * messages shouldn't be queued.
  57  */
  58 static int rds_release(struct socket *sock)
  59 {
  60         struct sock *sk = sock->sk;
  61         struct rds_sock *rs;
  62
  63         if (!sk)
  64                 goto out;
  65
  66         rs = rds_sk_to_rs(sk);
  67
  68         sock_orphan(sk);
  69         /* Note - rds_clear_recv_queue grabs rs_recv_lock, so
  70          * that ensures the recv path has completed messing
  71          * with the socket. */
  72         rds_clear_recv_queue(rs);
  73         rds_cong_remove_socket(rs);
  74
  75         /*
  76          * the binding lookup hash uses rcu, we need to
  77          * make sure we synchronize_rcu before we free our
  78          * entry
  79          */
  80         rds_remove_bound(rs);
  81         synchronize_rcu();
  82
  83         rds_send_drop_to(rs, NULL);
  84         rds_rdma_drop_keys(rs);
  85         rds_notify_queue_get(rs, NULL);
  86
  87         spin_lock_bh(&rds_sock_lock);
  88         list_del_init(&rs->rs_item);
  89         rds_sock_count--;
  90         spin_unlock_bh(&rds_sock_lock);
  91
  92         rds_trans_put(rs->rs_transport);
  93
  94         sock->sk = NULL;
  95         sock_put(sk);
  96 out:
  97         return 0;
  98 }
  99
 100 /*
 101  * Careful not to race with rds_release -> sock_orphan which clears sk_sleep.
 102  * _bh() isn't OK here, we're called from interrupt handlers.  It's probably OK
 103  * to wake the waitqueue after sk_sleep is clear as we hold a sock ref, but
 104  * this seems more conservative.
 105  * NB - normally, one would use sk_callback_lock for this, but we can
 106  * get here from interrupts, whereas the network code grabs sk_callback_lock
 107  * with _lock_bh only - so relying on sk_callback_lock introduces livelocks.
 108  */
 109 void rds_wake_sk_sleep(struct rds_sock *rs)
 110 {
 111         unsigned long flags;
 112
 113         read_lock_irqsave(&rs->rs_recv_lock, flags);
 114         __rds_wake_sk_sleep(rds_rs_to_sk(rs));
 115         read_unlock_irqrestore(&rs->rs_recv_lock, flags);
 116 }
 117
 118 static int rds_getname(struct socket *sock, struct sockaddr *uaddr,
 119                        int *uaddr_len, int peer)
 120 {
 121         struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
 122         struct rds_sock *rs = rds_sk_to_rs(sock->sk);
 123
 124         memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
 125
 126         /* racey, don't care */
 127         if (peer) {
 128                 if (!rs->rs_conn_addr)
 129                         return -ENOTCONN;
 130
 131                 sin->sin_port = rs->rs_conn_port;
 132                 sin->sin_addr.s_addr = rs->rs_conn_addr;
 133         } else {
 134                 sin->sin_port = rs->rs_bound_port;
 135                 sin->sin_addr.s_addr = rs->rs_bound_addr;
 136         }
 137
 138         sin->sin_family = AF_INET;
 139
 140         *uaddr_len = sizeof(*sin);
 141         return 0;
 142 }
 143
 144 /*
 145  * RDS' poll is without a doubt the least intuitive part of the interface,
 146  * as POLLIN and POLLOUT do not behave entirely as you would expect from
 147  * a network protocol.
 148  *
 149  * POLLIN is asserted if
 150  *  -   there is data on the receive queue.
 151  *  -   to signal that a previously congested destination may have become
 152  *      uncongested
 153  *  -   A notification has been queued to the socket (this can be a congestion
 154  *      update, or a RDMA completion).
 155  *
 156  * POLLOUT is asserted if there is room on the send queue. This does not mean
 157  * however, that the next sendmsg() call will succeed. If the application tries
 158  * to send to a congested destination, the system call may still fail (and
 159  * return ENOBUFS).
 160  */
 161 static unsigned int rds_poll(struct file *file, struct socket *sock,
 162                              poll_table *wait)
 163 {
 164         struct sock *sk = sock->sk;
 165         struct rds_sock *rs = rds_sk_to_rs(sk);
 166         unsigned int mask = 0;
 167         unsigned long flags;
 168
 169         poll_wait(file, sk_sleep(sk), wait);
 170
 171         if (rs->rs_seen_congestion)
 172                 poll_wait(file, &rds_poll_waitq, wait);
 173
 174         read_lock_irqsave(&rs->rs_recv_lock, flags);
 175         if (!rs->rs_cong_monitor) {
 176                 /* When a congestion map was updated, we signal POLLIN for
 177                  * "historical" reasons. Applications can also poll for
 178                  * WRBAND instead. */
 179                 if (rds_cong_updated_since(&rs->rs_cong_track))
 180                         mask |= (POLLIN | POLLRDNORM | POLLWRBAND);
 181         } else {
 182                 spin_lock(&rs->rs_lock);
 183                 if (rs->rs_cong_notify)
 184                         mask |= (POLLIN | POLLRDNORM);
 185                 spin_unlock(&rs->rs_lock);
 186         }
 187         if (!list_empty(&rs->rs_recv_queue) ||
 188             !list_empty(&rs->rs_notify_queue))
 189                 mask |= (POLLIN | POLLRDNORM);
 190         if (rs->rs_snd_bytes < rds_sk_sndbuf(rs))
 191                 mask |= (POLLOUT | POLLWRNORM);
 192         read_unlock_irqrestore(&rs->rs_recv_lock, flags);
 193
 194         /* clear state any time we wake a seen-congested socket */
 195         if (mask)
 196                 rs->rs_seen_congestion = 0;
 197
 198         return mask;
 199 }
 200
 201 static int rds_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 202 {
 203         return -ENOIOCTLCMD;
 204 }
 205
 206 static int rds_cancel_sent_to(struct rds_sock *rs, char __user *optval,
 207                               int len)
 208 {
 209         struct sockaddr_in sin;
 210         int ret = 0;
 211
 212         /* racing with another thread binding seems ok here */
 213         if (rs->rs_bound_addr == 0) {
 214                 ret = -ENOTCONN; /* XXX not a great errno */
 215                 goto out;
 216         }
 217
 218         if (len < sizeof(struct sockaddr_in)) {
 219                 ret = -EINVAL;
 220                 goto out;
 221         }
 222
 223         if (copy_from_user(&sin, optval, sizeof(sin))) {
 224                 ret = -EFAULT;
 225                 goto out;
 226         }
 227
 228         rds_send_drop_to(rs, &sin);
 229 out:
 230         return ret;
 231 }
 232
 233 static int rds_set_bool_option(unsigned char *optvar, char __user *optval,
 234                                int optlen)
 235 {
 236         int value;
 237
 238         if (optlen < sizeof(int))
 239                 return -EINVAL;
 240         if (get_user(value, (int __user *) optval))
 241                 return -EFAULT;
 242         *optvar = !!value;
 243         return 0;
 244 }
 245
 246 static int rds_cong_monitor(struct rds_sock *rs, char __user *optval,
 247                             int optlen)
 248 {
 249         int ret;
 250
 251         ret = rds_set_bool_option(&rs->rs_cong_monitor, optval, optlen);
 252         if (ret == 0) {
 253                 if (rs->rs_cong_monitor) {
 254                         rds_cong_add_socket(rs);
 255                 } else {
 256                         rds_cong_remove_socket(rs);
 257                         rs->rs_cong_mask = 0;
 258                         rs->rs_cong_notify = 0;
 259                 }
 260         }
 261         return ret;
 262 }
 263
 264 static int rds_set_transport(struct rds_sock *rs, char __user *optval,
 265                              int optlen)
 266 {
 267         int t_type;
 268
 269         if (rs->rs_transport)
 270                 return -EOPNOTSUPP; /* previously attached to transport */
 271
 272         if (optlen != sizeof(int))
 273                 return -EINVAL;
 274
 275         if (copy_from_user(&t_type, (int __user *)optval, sizeof(t_type)))
 276                 return -EFAULT;
 277
 278         if (t_type < 0 || t_type >= RDS_TRANS_COUNT)
 279                 return -EINVAL;
 280
 281         rs->rs_transport = rds_trans_get(t_type);
 282
 283         return rs->rs_transport ? 0 : -ENOPROTOOPT;
 284 }
 285
 286 static int rds_setsockopt(struct socket *sock, int level, int optname,
 287                           char __user *optval, unsigned int optlen)
 288 {
 289         struct rds_sock *rs = rds_sk_to_rs(sock->sk);
 290         int ret;
 291
 292         if (level != SOL_RDS) {
 293                 ret = -ENOPROTOOPT;
 294                 goto out;
 295         }
 296
 297         switch (optname) {
 298         case RDS_CANCEL_SENT_TO:
 299                 ret = rds_cancel_sent_to(rs, optval, optlen);
 300                 break;
 301         case RDS_GET_MR:
 302                 ret = rds_get_mr(rs, optval, optlen);
 303                 break;
 304         case RDS_GET_MR_FOR_DEST:
 305                 ret = rds_get_mr_for_dest(rs, optval, optlen);
 306                 break;
 307         case RDS_FREE_MR:
 308                 ret = rds_free_mr(rs, optval, optlen);
 309                 break;
 310         case RDS_RECVERR:
 311                 ret = rds_set_bool_option(&rs->rs_recverr, optval, optlen);
 312                 break;
 313         case RDS_CONG_MONITOR:
 314                 ret = rds_cong_monitor(rs, optval, optlen);
 315                 break;
 316         case SO_RDS_TRANSPORT:
 317                 lock_sock(sock->sk);
 318                 ret = rds_set_transport(rs, optval, optlen);
 319                 release_sock(sock->sk);
 320                 break;
 321         default:
 322                 ret = -ENOPROTOOPT;
 323         }
 324 out:
 325         return ret;
 326 }
 327
 328 static int rds_getsockopt(struct socket *sock, int level, int optname,
 329                           char __user *optval, int __user *optlen)
 330 {
 331         struct rds_sock *rs = rds_sk_to_rs(sock->sk);
 332         int ret = -ENOPROTOOPT, len;
 333         int trans;
 334
 335         if (level != SOL_RDS)
 336                 goto out;
 337
 338         if (get_user(len, optlen)) {
 339                 ret = -EFAULT;
 340                 goto out;
 341         }
 342
 343         switch (optname) {
 344         case RDS_INFO_FIRST ... RDS_INFO_LAST:
 345                 ret = rds_info_getsockopt(sock, optname, optval,
 346                                           optlen);
 347                 break;
 348
 349         case RDS_RECVERR:
 350                 if (len < sizeof(int))
 351                         ret = -EINVAL;
 352                 else
 353                 if (put_user(rs->rs_recverr, (int __user *) optval) ||
 354                     put_user(sizeof(int), optlen))
 355                         ret = -EFAULT;
 356                 else
 357                         ret = 0;
 358                 break;
 359         case SO_RDS_TRANSPORT:
 360                 if (len < sizeof(int)) {
 361                         ret = -EINVAL;
 362                         break;
 363                 }
 364                 trans = (rs->rs_transport ? rs->rs_transport->t_type :
 365                          RDS_TRANS_NONE); /* unbound */
 366                 if (put_user(trans, (int __user *)optval) ||
 367                     put_user(sizeof(int), optlen))
 368                         ret = -EFAULT;
 369                 else
 370                         ret = 0;
 371                 break;
 372         default:
 373                 break;
 374         }
 375
 376 out:
 377         return ret;
 378
 379 }
 380
 381 static int rds_connect(struct socket *sock, struct sockaddr *uaddr,
 382                        int addr_len, int flags)
 383 {
 384         struct sock *sk = sock->sk;
 385         struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
 386         struct rds_sock *rs = rds_sk_to_rs(sk);
 387         int ret = 0;
 388
 389         lock_sock(sk);
 390
 391         if (addr_len != sizeof(struct sockaddr_in)) {
 392                 ret = -EINVAL;
 393                 goto out;
 394         }
 395
 396         if (sin->sin_family != AF_INET) {
 397                 ret = -EAFNOSUPPORT;
 398                 goto out;
 399         }
 400
 401         if (sin->sin_addr.s_addr == htonl(INADDR_ANY)) {
 402                 ret = -EDESTADDRREQ;
 403                 goto out;
 404         }
 405
 406         rs->rs_conn_addr = sin->sin_addr.s_addr;
 407         rs->rs_conn_port = sin->sin_port;
 408
 409 out:
 410         release_sock(sk);
 411         return ret;
 412 }
 413
 414 static struct proto rds_proto = {
 415         .name     = "RDS",
 416         .owner    = THIS_MODULE,
 417         .obj_size = sizeof(struct rds_sock),
 418 };
 419
 420 static const struct proto_ops rds_proto_ops = {
 421         .family =       AF_RDS,
 422         .owner =        THIS_MODULE,
 423         .release =      rds_release,
 424         .bind =         rds_bind,
 425         .connect =      rds_connect,
 426         .socketpair =   sock_no_socketpair,
 427         .accept =       sock_no_accept,
 428         .getname =      rds_getname,
 429         .poll =         rds_poll,
 430         .ioctl =        rds_ioctl,
 431         .listen =       sock_no_listen,
 432         .shutdown =     sock_no_shutdown,
 433         .setsockopt =   rds_setsockopt,
 434         .getsockopt =   rds_getsockopt,
 435         .sendmsg =      rds_sendmsg,
 436         .recvmsg =      rds_recvmsg,
 437         .mmap =         sock_no_mmap,
 438         .sendpage =     sock_no_sendpage,
 439 };
 440
 441 static void rds_sock_destruct(struct sock *sk)
 442 {
 443         struct rds_sock *rs = rds_sk_to_rs(sk);
 444
 445         WARN_ON((&rs->rs_item != rs->rs_item.next ||
 446                  &rs->rs_item != rs->rs_item.prev));
 447 }
 448
 449 static int __rds_create(struct socket *sock, struct sock *sk, int protocol)
 450 {
 451         struct rds_sock *rs;
 452
 453         sock_init_data(sock, sk);
 454         sock->ops               = &rds_proto_ops;
 455         sk->sk_protocol         = protocol;
 456         sk->sk_destruct         = rds_sock_destruct;
 457
 458         rs = rds_sk_to_rs(sk);
 459         spin_lock_init(&rs->rs_lock);
 460         rwlock_init(&rs->rs_recv_lock);
 461         INIT_LIST_HEAD(&rs->rs_send_queue);
 462         INIT_LIST_HEAD(&rs->rs_recv_queue);
 463         INIT_LIST_HEAD(&rs->rs_notify_queue);
 464         INIT_LIST_HEAD(&rs->rs_cong_list);
 465         spin_lock_init(&rs->rs_rdma_lock);
 466         rs->rs_rdma_keys = RB_ROOT;
 467
 468         spin_lock_bh(&rds_sock_lock);
 469         list_add_tail(&rs->rs_item, &rds_sock_list);
 470         rds_sock_count++;
 471         spin_unlock_bh(&rds_sock_lock);
 472
 473         return 0;
 474 }
 475
 476 static int rds_create(struct net *net, struct socket *sock, int protocol,
 477                       int kern)
 478 {
 479         struct sock *sk;
 480
 481         if (sock->type != SOCK_SEQPACKET || protocol)
 482                 return -ESOCKTNOSUPPORT;
 483
 484         sk = sk_alloc(net, AF_RDS, GFP_ATOMIC, &rds_proto, kern);
 485         if (!sk)
 486                 return -ENOMEM;
 487
 488         return __rds_create(sock, sk, protocol);
 489 }
 490
 491 void rds_sock_addref(struct rds_sock *rs)
 492 {
 493         sock_hold(rds_rs_to_sk(rs));
 494 }
 495
 496 void rds_sock_put(struct rds_sock *rs)
 497 {
 498         sock_put(rds_rs_to_sk(rs));
 499 }
 500
 501 static const struct net_proto_family rds_family_ops = {
 502         .family =       AF_RDS,
 503         .create =       rds_create,
 504         .owner  =       THIS_MODULE,
 505 };
 506
 507 static void rds_sock_inc_info(struct socket *sock, unsigned int len,
 508                               struct rds_info_iterator *iter,
 509                               struct rds_info_lengths *lens)
 510 {
 511         struct rds_sock *rs;
 512         struct rds_incoming *inc;
 513         unsigned int total = 0;
 514
 515         len /= sizeof(struct rds_info_message);
 516
 517         spin_lock_bh(&rds_sock_lock);
 518
 519         list_for_each_entry(rs, &rds_sock_list, rs_item) {
 520                 read_lock(&rs->rs_recv_lock);
 521
 522                 /* XXX too lazy to maintain counts.. */
 523                 list_for_each_entry(inc, &rs->rs_recv_queue, i_item) {
 524                         total++;
 525                         if (total <= len)
 526                                 rds_inc_info_copy(inc, iter, inc->i_saddr,
 527                                                   rs->rs_bound_addr, 1);
 528                 }
 529
 530                 read_unlock(&rs->rs_recv_lock);
 531         }
 532
 533         spin_unlock_bh(&rds_sock_lock);
 534
 535         lens->nr = total;
 536         lens->each = sizeof(struct rds_info_message);
 537 }
 538
 539 static void rds_sock_info(struct socket *sock, unsigned int len,
 540                           struct rds_info_iterator *iter,
 541                           struct rds_info_lengths *lens)
 542 {
 543         struct rds_info_socket sinfo;
 544         struct rds_sock *rs;
 545
 546         len /= sizeof(struct rds_info_socket);
 547
 548         spin_lock_bh(&rds_sock_lock);
 549
 550         if (len < rds_sock_count)
 551                 goto out;
 552
 553         list_for_each_entry(rs, &rds_sock_list, rs_item) {
 554                 sinfo.sndbuf = rds_sk_sndbuf(rs);
 555                 sinfo.rcvbuf = rds_sk_rcvbuf(rs);
 556                 sinfo.bound_addr = rs->rs_bound_addr;
 557                 sinfo.connected_addr = rs->rs_conn_addr;
 558                 sinfo.bound_port = rs->rs_bound_port;
 559                 sinfo.connected_port = rs->rs_conn_port;
 560                 sinfo.inum = sock_i_ino(rds_rs_to_sk(rs));
 561
 562                 rds_info_copy(iter, &sinfo, sizeof(sinfo));
 563         }
 564
 565 out:
 566         lens->nr = rds_sock_count;
 567         lens->each = sizeof(struct rds_info_socket);
 568
 569         spin_unlock_bh(&rds_sock_lock);
 570 }
 571
 572 static void rds_exit(void)
 573 {
 574         sock_unregister(rds_family_ops.family);
 575         proto_unregister(&rds_proto);
 576         rds_conn_exit();
 577         rds_cong_exit();
 578         rds_sysctl_exit();
 579         rds_threads_exit();
 580         rds_stats_exit();
 581         rds_page_exit();
 582         rds_info_deregister_func(RDS_INFO_SOCKETS, rds_sock_info);
 583         rds_info_deregister_func(RDS_INFO_RECV_MESSAGES, rds_sock_inc_info);
 584 }
 585 module_exit(rds_exit);
 586
 587 static int rds_init(void)
 588 {
 589         int ret;
 590
 591         ret = rds_conn_init();
 592         if (ret)
 593                 goto out;
 594         ret = rds_threads_init();
 595         if (ret)
 596                 goto out_conn;
 597         ret = rds_sysctl_init();
 598         if (ret)
 599                 goto out_threads;
 600         ret = rds_stats_init();
 601         if (ret)
 602                 goto out_sysctl;
 603         ret = proto_register(&rds_proto, 1);
 604         if (ret)
 605                 goto out_stats;
 606         ret = sock_register(&rds_family_ops);
 607         if (ret)
 608                 goto out_proto;
 609
 610         rds_info_register_func(RDS_INFO_SOCKETS, rds_sock_info);
 611         rds_info_register_func(RDS_INFO_RECV_MESSAGES, rds_sock_inc_info);
 612
 613         goto out;
 614
 615 out_proto:
 616         proto_unregister(&rds_proto);
 617 out_stats:
 618         rds_stats_exit();
 619 out_sysctl:
 620         rds_sysctl_exit();
 621 out_threads:
 622         rds_threads_exit();
 623 out_conn:
 624         rds_conn_exit();
 625         rds_cong_exit();
 626         rds_page_exit();
 627 out:
 628         return ret;
 629 }
 630 module_init(rds_init);
 631
 632 #define DRV_VERSION     "4.0"
 633 #define DRV_RELDATE     "Feb 12, 2009"
 634
 635 MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
 636 MODULE_DESCRIPTION("RDS: Reliable Datagram Sockets"
 637                    " v" DRV_VERSION " (" DRV_RELDATE ")");
 638 MODULE_VERSION(DRV_VERSION);
 639 MODULE_LICENSE("Dual BSD/GPL");
 640 MODULE_ALIAS_NETPROTO(PF_RDS);