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