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