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