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