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->sk_sleep, wait);
 162
 163         poll_wait(file, &rds_poll_waitq, wait);
 164
 165         read_lock_irqsave(&rs->rs_recv_lock, flags);
 166         if (!rs->rs_cong_monitor) {
 167                 /* When a congestion map was updated, we signal POLLIN for
 168                  * "historical" reasons. Applications can also poll for
 169                  * WRBAND instead. */
 170                 if (rds_cong_updated_since(&rs->rs_cong_track))
 171                         mask |= (POLLIN | POLLRDNORM | POLLWRBAND);
 172         } else {
 173                 spin_lock(&rs->rs_lock);
 174                 if (rs->rs_cong_notify)
 175                         mask |= (POLLIN | POLLRDNORM);
 176                 spin_unlock(&rs->rs_lock);
 177         }
 178         if (!list_empty(&rs->rs_recv_queue) ||
 179             !list_empty(&rs->rs_notify_queue))
 180                 mask |= (POLLIN | POLLRDNORM);
 181         if (rs->rs_snd_bytes < rds_sk_sndbuf(rs))
 182                 mask |= (POLLOUT | POLLWRNORM);
 183         read_unlock_irqrestore(&rs->rs_recv_lock, flags);
 184
 185         return mask;
 186 }
 187
 188 static int rds_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 189 {
 190         return -ENOIOCTLCMD;
 191 }
 192
 193 static int rds_cancel_sent_to(struct rds_sock *rs, char __user *optval,
 194                               int len)
 195 {
 196         struct sockaddr_in sin;
 197         int ret = 0;
 198
 199         /* racing with another thread binding seems ok here */
 200         if (rs->rs_bound_addr == 0) {
 201                 ret = -ENOTCONN; /* XXX not a great errno */
 202                 goto out;
 203         }
 204
 205         if (len < sizeof(struct sockaddr_in)) {
 206                 ret = -EINVAL;
 207                 goto out;
 208         }
 209
 210         if (copy_from_user(&sin, optval, sizeof(sin))) {
 211                 ret = -EFAULT;
 212                 goto out;
 213         }
 214
 215         rds_send_drop_to(rs, &sin);
 216 out:
 217         return ret;
 218 }
 219
 220 static int rds_set_bool_option(unsigned char *optvar, char __user *optval,
 221                                int optlen)
 222 {
 223         int value;
 224
 225         if (optlen < sizeof(int))
 226                 return -EINVAL;
 227         if (get_user(value, (int __user *) optval))
 228                 return -EFAULT;
 229         *optvar = !!value;
 230         return 0;
 231 }
 232
 233 static int rds_cong_monitor(struct rds_sock *rs, char __user *optval,
 234                             int optlen)
 235 {
 236         int ret;
 237
 238         ret = rds_set_bool_option(&rs->rs_cong_monitor, optval, optlen);
 239         if (ret == 0) {
 240                 if (rs->rs_cong_monitor) {
 241                         rds_cong_add_socket(rs);
 242                 } else {
 243                         rds_cong_remove_socket(rs);
 244                         rs->rs_cong_mask = 0;
 245                         rs->rs_cong_notify = 0;
 246                 }
 247         }
 248         return ret;
 249 }
 250
 251 static int rds_setsockopt(struct socket *sock, int level, int optname,
 252                           char __user *optval, unsigned int optlen)
 253 {
 254         struct rds_sock *rs = rds_sk_to_rs(sock->sk);
 255         int ret;
 256
 257         if (level != SOL_RDS) {
 258                 ret = -ENOPROTOOPT;
 259                 goto out;
 260         }
 261
 262         switch (optname) {
 263         case RDS_CANCEL_SENT_TO:
 264                 ret = rds_cancel_sent_to(rs, optval, optlen);
 265                 break;
 266         case RDS_GET_MR:
 267                 ret = rds_get_mr(rs, optval, optlen);
 268                 break;
 269         case RDS_GET_MR_FOR_DEST:
 270                 ret = rds_get_mr_for_dest(rs, optval, optlen);
 271                 break;
 272         case RDS_FREE_MR:
 273                 ret = rds_free_mr(rs, optval, optlen);
 274                 break;
 275         case RDS_RECVERR:
 276                 ret = rds_set_bool_option(&rs->rs_recverr, optval, optlen);
 277                 break;
 278         case RDS_CONG_MONITOR:
 279                 ret = rds_cong_monitor(rs, optval, optlen);
 280                 break;
 281         default:
 282                 ret = -ENOPROTOOPT;
 283         }
 284 out:
 285         return ret;
 286 }
 287
 288 static int rds_getsockopt(struct socket *sock, int level, int optname,
 289                           char __user *optval, int __user *optlen)
 290 {
 291         struct rds_sock *rs = rds_sk_to_rs(sock->sk);
 292         int ret = -ENOPROTOOPT, len;
 293
 294         if (level != SOL_RDS)
 295                 goto out;
 296
 297         if (get_user(len, optlen)) {
 298                 ret = -EFAULT;
 299                 goto out;
 300         }
 301
 302         switch (optname) {
 303         case RDS_INFO_FIRST ... RDS_INFO_LAST:
 304                 ret = rds_info_getsockopt(sock, optname, optval,
 305                                           optlen);
 306                 break;
 307
 308         case RDS_RECVERR:
 309                 if (len < sizeof(int))
 310                         ret = -EINVAL;
 311                 else
 312                 if (put_user(rs->rs_recverr, (int __user *) optval) ||
 313                     put_user(sizeof(int), optlen))
 314                         ret = -EFAULT;
 315                 else
 316                         ret = 0;
 317                 break;
 318         default:
 319                 break;
 320         }
 321
 322 out:
 323         return ret;
 324
 325 }
 326
 327 static int rds_connect(struct socket *sock, struct sockaddr *uaddr,
 328                        int addr_len, int flags)
 329 {
 330         struct sock *sk = sock->sk;
 331         struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
 332         struct rds_sock *rs = rds_sk_to_rs(sk);
 333         int ret = 0;
 334
 335         lock_sock(sk);
 336
 337         if (addr_len != sizeof(struct sockaddr_in)) {
 338                 ret = -EINVAL;
 339                 goto out;
 340         }
 341
 342         if (sin->sin_family != AF_INET) {
 343                 ret = -EAFNOSUPPORT;
 344                 goto out;
 345         }
 346
 347         if (sin->sin_addr.s_addr == htonl(INADDR_ANY)) {
 348                 ret = -EDESTADDRREQ;
 349                 goto out;
 350         }
 351
 352         rs->rs_conn_addr = sin->sin_addr.s_addr;
 353         rs->rs_conn_port = sin->sin_port;
 354
 355 out:
 356         release_sock(sk);
 357         return ret;
 358 }
 359
 360 static struct proto rds_proto = {
 361         .name     = "RDS",
 362         .owner    = THIS_MODULE,
 363         .obj_size = sizeof(struct rds_sock),
 364 };
 365
 366 static const struct proto_ops rds_proto_ops = {
 367         .family =       AF_RDS,
 368         .owner =        THIS_MODULE,
 369         .release =      rds_release,
 370         .bind =         rds_bind,
 371         .connect =      rds_connect,
 372         .socketpair =   sock_no_socketpair,
 373         .accept =       sock_no_accept,
 374         .getname =      rds_getname,
 375         .poll =         rds_poll,
 376         .ioctl =        rds_ioctl,
 377         .listen =       sock_no_listen,
 378         .shutdown =     sock_no_shutdown,
 379         .setsockopt =   rds_setsockopt,
 380         .getsockopt =   rds_getsockopt,
 381         .sendmsg =      rds_sendmsg,
 382         .recvmsg =      rds_recvmsg,
 383         .mmap =         sock_no_mmap,
 384         .sendpage =     sock_no_sendpage,
 385 };
 386
 387 static int __rds_create(struct socket *sock, struct sock *sk, int protocol)
 388 {
 389         unsigned long flags;
 390         struct rds_sock *rs;
 391
 392         sock_init_data(sock, sk);
 393         sock->ops               = &rds_proto_ops;
 394         sk->sk_protocol         = protocol;
 395
 396         rs = rds_sk_to_rs(sk);
 397         spin_lock_init(&rs->rs_lock);
 398         rwlock_init(&rs->rs_recv_lock);
 399         INIT_LIST_HEAD(&rs->rs_send_queue);
 400         INIT_LIST_HEAD(&rs->rs_recv_queue);
 401         INIT_LIST_HEAD(&rs->rs_notify_queue);
 402         INIT_LIST_HEAD(&rs->rs_cong_list);
 403         spin_lock_init(&rs->rs_rdma_lock);
 404         rs->rs_rdma_keys = RB_ROOT;
 405
 406         spin_lock_irqsave(&rds_sock_lock, flags);
 407         list_add_tail(&rs->rs_item, &rds_sock_list);
 408         rds_sock_count++;
 409         spin_unlock_irqrestore(&rds_sock_lock, flags);
 410
 411         return 0;
 412 }
 413
 414 static int rds_create(struct net *net, struct socket *sock, int protocol,
 415                       int kern)
 416 {
 417         struct sock *sk;
 418
 419         if (sock->type != SOCK_SEQPACKET || protocol)
 420                 return -ESOCKTNOSUPPORT;
 421
 422         sk = sk_alloc(net, AF_RDS, GFP_ATOMIC, &rds_proto);
 423         if (!sk)
 424                 return -ENOMEM;
 425
 426         return __rds_create(sock, sk, protocol);
 427 }
 428
 429 void rds_sock_addref(struct rds_sock *rs)
 430 {
 431         sock_hold(rds_rs_to_sk(rs));
 432 }
 433
 434 void rds_sock_put(struct rds_sock *rs)
 435 {
 436         sock_put(rds_rs_to_sk(rs));
 437 }
 438
 439 static const struct net_proto_family rds_family_ops = {
 440         .family =       AF_RDS,
 441         .create =       rds_create,
 442         .owner  =       THIS_MODULE,
 443 };
 444
 445 static void rds_sock_inc_info(struct socket *sock, unsigned int len,
 446                               struct rds_info_iterator *iter,
 447                               struct rds_info_lengths *lens)
 448 {
 449         struct rds_sock *rs;
 450         struct sock *sk;
 451         struct rds_incoming *inc;
 452         unsigned long flags;
 453         unsigned int total = 0;
 454
 455         len /= sizeof(struct rds_info_message);
 456
 457         spin_lock_irqsave(&rds_sock_lock, flags);
 458
 459         list_for_each_entry(rs, &rds_sock_list, rs_item) {
 460                 sk = rds_rs_to_sk(rs);
 461                 read_lock(&rs->rs_recv_lock);
 462
 463                 /* XXX too lazy to maintain counts.. */
 464                 list_for_each_entry(inc, &rs->rs_recv_queue, i_item) {
 465                         total++;
 466                         if (total <= len)
 467                                 rds_inc_info_copy(inc, iter, inc->i_saddr,
 468                                                   rs->rs_bound_addr, 1);
 469                 }
 470
 471                 read_unlock(&rs->rs_recv_lock);
 472         }
 473
 474         spin_unlock_irqrestore(&rds_sock_lock, flags);
 475
 476         lens->nr = total;
 477         lens->each = sizeof(struct rds_info_message);
 478 }
 479
 480 static void rds_sock_info(struct socket *sock, unsigned int len,
 481                           struct rds_info_iterator *iter,
 482                           struct rds_info_lengths *lens)
 483 {
 484         struct rds_info_socket sinfo;
 485         struct rds_sock *rs;
 486         unsigned long flags;
 487
 488         len /= sizeof(struct rds_info_socket);
 489
 490         spin_lock_irqsave(&rds_sock_lock, flags);
 491
 492         if (len < rds_sock_count)
 493                 goto out;
 494
 495         list_for_each_entry(rs, &rds_sock_list, rs_item) {
 496                 sinfo.sndbuf = rds_sk_sndbuf(rs);
 497                 sinfo.rcvbuf = rds_sk_rcvbuf(rs);
 498                 sinfo.bound_addr = rs->rs_bound_addr;
 499                 sinfo.connected_addr = rs->rs_conn_addr;
 500                 sinfo.bound_port = rs->rs_bound_port;
 501                 sinfo.connected_port = rs->rs_conn_port;
 502                 sinfo.inum = sock_i_ino(rds_rs_to_sk(rs));
 503
 504                 rds_info_copy(iter, &sinfo, sizeof(sinfo));
 505         }
 506
 507 out:
 508         lens->nr = rds_sock_count;
 509         lens->each = sizeof(struct rds_info_socket);
 510
 511         spin_unlock_irqrestore(&rds_sock_lock, flags);
 512 }
 513
 514 static void __exit rds_exit(void)
 515 {
 516         sock_unregister(rds_family_ops.family);
 517         proto_unregister(&rds_proto);
 518         rds_conn_exit();
 519         rds_cong_exit();
 520         rds_sysctl_exit();
 521         rds_threads_exit();
 522         rds_stats_exit();
 523         rds_page_exit();
 524         rds_info_deregister_func(RDS_INFO_SOCKETS, rds_sock_info);
 525         rds_info_deregister_func(RDS_INFO_RECV_MESSAGES, rds_sock_inc_info);
 526 }
 527 module_exit(rds_exit);
 528
 529 static int __init rds_init(void)
 530 {
 531         int ret;
 532
 533         ret = rds_conn_init();
 534         if (ret)
 535                 goto out;
 536         ret = rds_threads_init();
 537         if (ret)
 538                 goto out_conn;
 539         ret = rds_sysctl_init();
 540         if (ret)
 541                 goto out_threads;
 542         ret = rds_stats_init();
 543         if (ret)
 544                 goto out_sysctl;
 545         ret = proto_register(&rds_proto, 1);
 546         if (ret)
 547                 goto out_stats;
 548         ret = sock_register(&rds_family_ops);
 549         if (ret)
 550                 goto out_proto;
 551
 552         rds_info_register_func(RDS_INFO_SOCKETS, rds_sock_info);
 553         rds_info_register_func(RDS_INFO_RECV_MESSAGES, rds_sock_inc_info);
 554
 555         goto out;
 556
 557 out_proto:
 558         proto_unregister(&rds_proto);
 559 out_stats:
 560         rds_stats_exit();
 561 out_sysctl:
 562         rds_sysctl_exit();
 563 out_threads:
 564         rds_threads_exit();
 565 out_conn:
 566         rds_conn_exit();
 567         rds_cong_exit();
 568         rds_page_exit();
 569 out:
 570         return ret;
 571 }
 572 module_init(rds_init);
 573
 574 #define DRV_VERSION     "4.0"
 575 #define DRV_RELDATE     "Feb 12, 2009"
 576
 577 MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
 578 MODULE_DESCRIPTION("RDS: Reliable Datagram Sockets"
 579                    " v" DRV_VERSION " (" DRV_RELDATE ")");
 580 MODULE_VERSION(DRV_VERSION);
 581 MODULE_LICENSE("Dual BSD/GPL");
 582 MODULE_ALIAS_NETPROTO(PF_RDS);