net/phonet/socket.c

   1 /*
   2  * File: socket.c
   3  *
   4  * Phonet sockets
   5  *
   6  * Copyright (C) 2008 Nokia Corporation.
   7  *
   8  * Authors: Sakari Ailus <sakari.ailus@nokia.com>
   9  *          Rémi Denis-Courmont
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * version 2 as published by the Free Software Foundation.
  14  *
  15  * This program is distributed in the hope that it will be useful, but
  16  * WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  23  * 02110-1301 USA
  24  */
  25
  26 #include <linux/gfp.h>
  27 #include <linux/kernel.h>
  28 #include <linux/net.h>
  29 #include <linux/poll.h>
  30 #include <net/sock.h>
  31 #include <net/tcp_states.h>
  32
  33 #include <linux/phonet.h>
  34 #include <linux/export.h>
  35 #include <net/phonet/phonet.h>
  36 #include <net/phonet/pep.h>
  37 #include <net/phonet/pn_dev.h>
  38
  39 static int pn_socket_release(struct socket *sock)
  40 {
  41         struct sock *sk = sock->sk;
  42
  43         if (sk) {
  44                 sock->sk = NULL;
  45                 sk->sk_prot->close(sk, 0);
  46         }
  47         return 0;
  48 }
  49
  50 #define PN_HASHSIZE     16
  51 #define PN_HASHMASK     (PN_HASHSIZE-1)
  52
  53
  54 static struct  {
  55         struct hlist_head hlist[PN_HASHSIZE];
  56         struct mutex lock;
  57 } pnsocks;
  58
  59 void __init pn_sock_init(void)
  60 {
  61         unsigned int i;
  62
  63         for (i = 0; i < PN_HASHSIZE; i++)
  64                 INIT_HLIST_HEAD(pnsocks.hlist + i);
  65         mutex_init(&pnsocks.lock);
  66 }
  67
  68 static struct hlist_head *pn_hash_list(u16 obj)
  69 {
  70         return pnsocks.hlist + (obj & PN_HASHMASK);
  71 }
  72
  73 /*
  74  * Find address based on socket address, match only certain fields.
  75  * Also grab sock if it was found. Remember to sock_put it later.
  76  */
  77 struct sock *pn_find_sock_by_sa(struct net *net, const struct sockaddr_pn *spn)
  78 {
  79         struct sock *sknode;
  80         struct sock *rval = NULL;
  81         u16 obj = pn_sockaddr_get_object(spn);
  82         u8 res = spn->spn_resource;
  83         struct hlist_head *hlist = pn_hash_list(obj);
  84
  85         rcu_read_lock();
  86         sk_for_each_rcu(sknode, hlist) {
  87                 struct pn_sock *pn = pn_sk(sknode);
  88                 BUG_ON(!pn->sobject); /* unbound socket */
  89
  90                 if (!net_eq(sock_net(sknode), net))
  91                         continue;
  92                 if (pn_port(obj)) {
  93                         /* Look up socket by port */
  94                         if (pn_port(pn->sobject) != pn_port(obj))
  95                                 continue;
  96                 } else {
  97                         /* If port is zero, look up by resource */
  98                         if (pn->resource != res)
  99                                 continue;
 100                 }
 101                 if (pn_addr(pn->sobject) &&
 102                     pn_addr(pn->sobject) != pn_addr(obj))
 103                         continue;
 104
 105                 rval = sknode;
 106                 sock_hold(sknode);
 107                 break;
 108         }
 109         rcu_read_unlock();
 110
 111         return rval;
 112 }
 113
 114 /* Deliver a broadcast packet (only in bottom-half) */
 115 void pn_deliver_sock_broadcast(struct net *net, struct sk_buff *skb)
 116 {
 117         struct hlist_head *hlist = pnsocks.hlist;
 118         unsigned int h;
 119
 120         rcu_read_lock();
 121         for (h = 0; h < PN_HASHSIZE; h++) {
 122                 struct sock *sknode;
 123
 124                 sk_for_each(sknode, hlist) {
 125                         struct sk_buff *clone;
 126
 127                         if (!net_eq(sock_net(sknode), net))
 128                                 continue;
 129                         if (!sock_flag(sknode, SOCK_BROADCAST))
 130                                 continue;
 131
 132                         clone = skb_clone(skb, GFP_ATOMIC);
 133                         if (clone) {
 134                                 sock_hold(sknode);
 135                                 sk_receive_skb(sknode, clone, 0);
 136                         }
 137                 }
 138                 hlist++;
 139         }
 140         rcu_read_unlock();
 141 }
 142
 143 void pn_sock_hash(struct sock *sk)
 144 {
 145         struct hlist_head *hlist = pn_hash_list(pn_sk(sk)->sobject);
 146
 147         mutex_lock(&pnsocks.lock);
 148         sk_add_node_rcu(sk, hlist);
 149         mutex_unlock(&pnsocks.lock);
 150 }
 151 EXPORT_SYMBOL(pn_sock_hash);
 152
 153 void pn_sock_unhash(struct sock *sk)
 154 {
 155         mutex_lock(&pnsocks.lock);
 156         sk_del_node_init_rcu(sk);
 157         mutex_unlock(&pnsocks.lock);
 158         pn_sock_unbind_all_res(sk);
 159         synchronize_rcu();
 160 }
 161 EXPORT_SYMBOL(pn_sock_unhash);
 162
 163 static DEFINE_MUTEX(port_mutex);
 164
 165 static int pn_socket_bind(struct socket *sock, struct sockaddr *addr, int len)
 166 {
 167         struct sock *sk = sock->sk;
 168         struct pn_sock *pn = pn_sk(sk);
 169         struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
 170         int err;
 171         u16 handle;
 172         u8 saddr;
 173
 174         if (sk->sk_prot->bind)
 175                 return sk->sk_prot->bind(sk, addr, len);
 176
 177         if (len < sizeof(struct sockaddr_pn))
 178                 return -EINVAL;
 179         if (spn->spn_family != AF_PHONET)
 180                 return -EAFNOSUPPORT;
 181
 182         handle = pn_sockaddr_get_object((struct sockaddr_pn *)addr);
 183         saddr = pn_addr(handle);
 184         if (saddr && phonet_address_lookup(sock_net(sk), saddr))
 185                 return -EADDRNOTAVAIL;
 186
 187         lock_sock(sk);
 188         if (sk->sk_state != TCP_CLOSE || pn_port(pn->sobject)) {
 189                 err = -EINVAL; /* attempt to rebind */
 190                 goto out;
 191         }
 192         WARN_ON(sk_hashed(sk));
 193         mutex_lock(&port_mutex);
 194         err = sk->sk_prot->get_port(sk, pn_port(handle));
 195         if (err)
 196                 goto out_port;
 197
 198         /* get_port() sets the port, bind() sets the address if applicable */
 199         pn->sobject = pn_object(saddr, pn_port(pn->sobject));
 200         pn->resource = spn->spn_resource;
 201
 202         /* Enable RX on the socket */
 203         sk->sk_prot->hash(sk);
 204 out_port:
 205         mutex_unlock(&port_mutex);
 206 out:
 207         release_sock(sk);
 208         return err;
 209 }
 210
 211 static int pn_socket_autobind(struct socket *sock)
 212 {
 213         struct sockaddr_pn sa;
 214         int err;
 215
 216         memset(&sa, 0, sizeof(sa));
 217         sa.spn_family = AF_PHONET;
 218         err = pn_socket_bind(sock, (struct sockaddr *)&sa,
 219                                 sizeof(struct sockaddr_pn));
 220         if (err != -EINVAL)
 221                 return err;
 222         BUG_ON(!pn_port(pn_sk(sock->sk)->sobject));
 223         return 0; /* socket was already bound */
 224 }
 225
 226 static int pn_socket_connect(struct socket *sock, struct sockaddr *addr,
 227                 int len, int flags)
 228 {
 229         struct sock *sk = sock->sk;
 230         struct pn_sock *pn = pn_sk(sk);
 231         struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
 232         struct task_struct *tsk = current;
 233         long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
 234         int err;
 235
 236         if (pn_socket_autobind(sock))
 237                 return -ENOBUFS;
 238         if (len < sizeof(struct sockaddr_pn))
 239                 return -EINVAL;
 240         if (spn->spn_family != AF_PHONET)
 241                 return -EAFNOSUPPORT;
 242
 243         lock_sock(sk);
 244
 245         switch (sock->state) {
 246         case SS_UNCONNECTED:
 247                 if (sk->sk_state != TCP_CLOSE) {
 248                         err = -EISCONN;
 249                         goto out;
 250                 }
 251                 break;
 252         case SS_CONNECTING:
 253                 err = -EALREADY;
 254                 goto out;
 255         default:
 256                 err = -EISCONN;
 257                 goto out;
 258         }
 259
 260         pn->dobject = pn_sockaddr_get_object(spn);
 261         pn->resource = pn_sockaddr_get_resource(spn);
 262         sock->state = SS_CONNECTING;
 263
 264         err = sk->sk_prot->connect(sk, addr, len);
 265         if (err) {
 266                 sock->state = SS_UNCONNECTED;
 267                 pn->dobject = 0;
 268                 goto out;
 269         }
 270
 271         while (sk->sk_state == TCP_SYN_SENT) {
 272                 DEFINE_WAIT(wait);
 273
 274                 if (!timeo) {
 275                         err = -EINPROGRESS;
 276                         goto out;
 277                 }
 278                 if (signal_pending(tsk)) {
 279                         err = sock_intr_errno(timeo);
 280                         goto out;
 281                 }
 282
 283                 prepare_to_wait_exclusive(sk_sleep(sk), &wait,
 284                                                 TASK_INTERRUPTIBLE);
 285                 release_sock(sk);
 286                 timeo = schedule_timeout(timeo);
 287                 lock_sock(sk);
 288                 finish_wait(sk_sleep(sk), &wait);
 289         }
 290
 291         if ((1 << sk->sk_state) & (TCPF_SYN_RECV|TCPF_ESTABLISHED))
 292                 err = 0;
 293         else if (sk->sk_state == TCP_CLOSE_WAIT)
 294                 err = -ECONNRESET;
 295         else
 296                 err = -ECONNREFUSED;
 297         sock->state = err ? SS_UNCONNECTED : SS_CONNECTED;
 298 out:
 299         release_sock(sk);
 300         return err;
 301 }
 302
 303 static int pn_socket_accept(struct socket *sock, struct socket *newsock,
 304                                 int flags)
 305 {
 306         struct sock *sk = sock->sk;
 307         struct sock *newsk;
 308         int err;
 309
 310         if (unlikely(sk->sk_state != TCP_LISTEN))
 311                 return -EINVAL;
 312
 313         newsk = sk->sk_prot->accept(sk, flags, &err);
 314         if (!newsk)
 315                 return err;
 316
 317         lock_sock(newsk);
 318         sock_graft(newsk, newsock);
 319         newsock->state = SS_CONNECTED;
 320         release_sock(newsk);
 321         return 0;
 322 }
 323
 324 static int pn_socket_getname(struct socket *sock, struct sockaddr *addr,
 325                                 int *sockaddr_len, int peer)
 326 {
 327         struct sock *sk = sock->sk;
 328         struct pn_sock *pn = pn_sk(sk);
 329
 330         memset(addr, 0, sizeof(struct sockaddr_pn));
 331         addr->sa_family = AF_PHONET;
 332         if (!peer) /* Race with bind() here is userland's problem. */
 333                 pn_sockaddr_set_object((struct sockaddr_pn *)addr,
 334                                         pn->sobject);
 335
 336         *sockaddr_len = sizeof(struct sockaddr_pn);
 337         return 0;
 338 }
 339
 340 static unsigned int pn_socket_poll(struct file *file, struct socket *sock,
 341                                         poll_table *wait)
 342 {
 343         struct sock *sk = sock->sk;
 344         struct pep_sock *pn = pep_sk(sk);
 345         unsigned int mask = 0;
 346
 347         poll_wait(file, sk_sleep(sk), wait);
 348
 349         if (sk->sk_state == TCP_CLOSE)
 350                 return POLLERR;
 351         if (!skb_queue_empty(&sk->sk_receive_queue))
 352                 mask |= POLLIN | POLLRDNORM;
 353         if (!skb_queue_empty(&pn->ctrlreq_queue))
 354                 mask |= POLLPRI;
 355         if (!mask && sk->sk_state == TCP_CLOSE_WAIT)
 356                 return POLLHUP;
 357
 358         if (sk->sk_state == TCP_ESTABLISHED &&
 359                 atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf &&
 360                 atomic_read(&pn->tx_credits))
 361                 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
 362
 363         return mask;
 364 }
 365
 366 static int pn_socket_ioctl(struct socket *sock, unsigned int cmd,
 367                                 unsigned long arg)
 368 {
 369         struct sock *sk = sock->sk;
 370         struct pn_sock *pn = pn_sk(sk);
 371
 372         if (cmd == SIOCPNGETOBJECT) {
 373                 struct net_device *dev;
 374                 u16 handle;
 375                 u8 saddr;
 376
 377                 if (get_user(handle, (__u16 __user *)arg))
 378                         return -EFAULT;
 379
 380                 lock_sock(sk);
 381                 if (sk->sk_bound_dev_if)
 382                         dev = dev_get_by_index(sock_net(sk),
 383                                                 sk->sk_bound_dev_if);
 384                 else
 385                         dev = phonet_device_get(sock_net(sk));
 386                 if (dev && (dev->flags & IFF_UP))
 387                         saddr = phonet_address_get(dev, pn_addr(handle));
 388                 else
 389                         saddr = PN_NO_ADDR;
 390                 release_sock(sk);
 391
 392                 if (dev)
 393                         dev_put(dev);
 394                 if (saddr == PN_NO_ADDR)
 395                         return -EHOSTUNREACH;
 396
 397                 handle = pn_object(saddr, pn_port(pn->sobject));
 398                 return put_user(handle, (__u16 __user *)arg);
 399         }
 400
 401         return sk->sk_prot->ioctl(sk, cmd, arg);
 402 }
 403
 404 static int pn_socket_listen(struct socket *sock, int backlog)
 405 {
 406         struct sock *sk = sock->sk;
 407         int err = 0;
 408
 409         if (pn_socket_autobind(sock))
 410                 return -ENOBUFS;
 411
 412         lock_sock(sk);
 413         if (sock->state != SS_UNCONNECTED) {
 414                 err = -EINVAL;
 415                 goto out;
 416         }
 417
 418         if (sk->sk_state != TCP_LISTEN) {
 419                 sk->sk_state = TCP_LISTEN;
 420                 sk->sk_ack_backlog = 0;
 421         }
 422         sk->sk_max_ack_backlog = backlog;
 423 out:
 424         release_sock(sk);
 425         return err;
 426 }
 427
 428 static int pn_socket_sendmsg(struct kiocb *iocb, struct socket *sock,
 429                                 struct msghdr *m, size_t total_len)
 430 {
 431         struct sock *sk = sock->sk;
 432
 433         if (pn_socket_autobind(sock))
 434                 return -EAGAIN;
 435
 436         return sk->sk_prot->sendmsg(iocb, sk, m, total_len);
 437 }
 438
 439 const struct proto_ops phonet_dgram_ops = {
 440         .family         = AF_PHONET,
 441         .owner          = THIS_MODULE,
 442         .release        = pn_socket_release,
 443         .bind           = pn_socket_bind,
 444         .connect        = sock_no_connect,
 445         .socketpair     = sock_no_socketpair,
 446         .accept         = sock_no_accept,
 447         .getname        = pn_socket_getname,
 448         .poll           = datagram_poll,
 449         .ioctl          = pn_socket_ioctl,
 450         .listen         = sock_no_listen,
 451         .shutdown       = sock_no_shutdown,
 452         .setsockopt     = sock_no_setsockopt,
 453         .getsockopt     = sock_no_getsockopt,
 454 #ifdef CONFIG_COMPAT
 455         .compat_setsockopt = sock_no_setsockopt,
 456         .compat_getsockopt = sock_no_getsockopt,
 457 #endif
 458         .sendmsg        = pn_socket_sendmsg,
 459         .recvmsg        = sock_common_recvmsg,
 460         .mmap           = sock_no_mmap,
 461         .sendpage       = sock_no_sendpage,
 462 };
 463
 464 const struct proto_ops phonet_stream_ops = {
 465         .family         = AF_PHONET,
 466         .owner          = THIS_MODULE,
 467         .release        = pn_socket_release,
 468         .bind           = pn_socket_bind,
 469         .connect        = pn_socket_connect,
 470         .socketpair     = sock_no_socketpair,
 471         .accept         = pn_socket_accept,
 472         .getname        = pn_socket_getname,
 473         .poll           = pn_socket_poll,
 474         .ioctl          = pn_socket_ioctl,
 475         .listen         = pn_socket_listen,
 476         .shutdown       = sock_no_shutdown,
 477         .setsockopt     = sock_common_setsockopt,
 478         .getsockopt     = sock_common_getsockopt,
 479 #ifdef CONFIG_COMPAT
 480         .compat_setsockopt = compat_sock_common_setsockopt,
 481         .compat_getsockopt = compat_sock_common_getsockopt,
 482 #endif
 483         .sendmsg        = pn_socket_sendmsg,
 484         .recvmsg        = sock_common_recvmsg,
 485         .mmap           = sock_no_mmap,
 486         .sendpage       = sock_no_sendpage,
 487 };
 488 EXPORT_SYMBOL(phonet_stream_ops);
 489
 490 /* allocate port for a socket */
 491 int pn_sock_get_port(struct sock *sk, unsigned short sport)
 492 {
 493         static int port_cur;
 494         struct net *net = sock_net(sk);
 495         struct pn_sock *pn = pn_sk(sk);
 496         struct sockaddr_pn try_sa;
 497         struct sock *tmpsk;
 498
 499         memset(&try_sa, 0, sizeof(struct sockaddr_pn));
 500         try_sa.spn_family = AF_PHONET;
 501         WARN_ON(!mutex_is_locked(&port_mutex));
 502         if (!sport) {
 503                 /* search free port */
 504                 int port, pmin, pmax;
 505
 506                 phonet_get_local_port_range(&pmin, &pmax);
 507                 for (port = pmin; port <= pmax; port++) {
 508                         port_cur++;
 509                         if (port_cur < pmin || port_cur > pmax)
 510                                 port_cur = pmin;
 511
 512                         pn_sockaddr_set_port(&try_sa, port_cur);
 513                         tmpsk = pn_find_sock_by_sa(net, &try_sa);
 514                         if (tmpsk == NULL) {
 515                                 sport = port_cur;
 516                                 goto found;
 517                         } else
 518                                 sock_put(tmpsk);
 519                 }
 520         } else {
 521                 /* try to find specific port */
 522                 pn_sockaddr_set_port(&try_sa, sport);
 523                 tmpsk = pn_find_sock_by_sa(net, &try_sa);
 524                 if (tmpsk == NULL)
 525                         /* No sock there! We can use that port... */
 526                         goto found;
 527                 else
 528                         sock_put(tmpsk);
 529         }
 530         /* the port must be in use already */
 531         return -EADDRINUSE;
 532
 533 found:
 534         pn->sobject = pn_object(pn_addr(pn->sobject), sport);
 535         return 0;
 536 }
 537 EXPORT_SYMBOL(pn_sock_get_port);
 538
 539 #ifdef CONFIG_PROC_FS
 540 static struct sock *pn_sock_get_idx(struct seq_file *seq, loff_t pos)
 541 {
 542         struct net *net = seq_file_net(seq);
 543         struct hlist_head *hlist = pnsocks.hlist;
 544         struct sock *sknode;
 545         unsigned int h;
 546
 547         for (h = 0; h < PN_HASHSIZE; h++) {
 548                 sk_for_each_rcu(sknode, hlist) {
 549                         if (!net_eq(net, sock_net(sknode)))
 550                                 continue;
 551                         if (!pos)
 552                                 return sknode;
 553                         pos--;
 554                 }
 555                 hlist++;
 556         }
 557         return NULL;
 558 }
 559
 560 static struct sock *pn_sock_get_next(struct seq_file *seq, struct sock *sk)
 561 {
 562         struct net *net = seq_file_net(seq);
 563
 564         do
 565                 sk = sk_next(sk);
 566         while (sk && !net_eq(net, sock_net(sk)));
 567
 568         return sk;
 569 }
 570
 571 static void *pn_sock_seq_start(struct seq_file *seq, loff_t *pos)
 572         __acquires(rcu)
 573 {
 574         rcu_read_lock();
 575         return *pos ? pn_sock_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 576 }
 577
 578 static void *pn_sock_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 579 {
 580         struct sock *sk;
 581
 582         if (v == SEQ_START_TOKEN)
 583                 sk = pn_sock_get_idx(seq, 0);
 584         else
 585                 sk = pn_sock_get_next(seq, v);
 586         (*pos)++;
 587         return sk;
 588 }
 589
 590 static void pn_sock_seq_stop(struct seq_file *seq, void *v)
 591         __releases(rcu)
 592 {
 593         rcu_read_unlock();
 594 }
 595
 596 static int pn_sock_seq_show(struct seq_file *seq, void *v)
 597 {
 598         int len;
 599
 600         if (v == SEQ_START_TOKEN)
 601                 seq_printf(seq, "%s%n", "pt  loc  rem rs st tx_queue rx_queue "
 602                         "  uid inode ref pointer drops", &len);
 603         else {
 604                 struct sock *sk = v;
 605                 struct pn_sock *pn = pn_sk(sk);
 606
 607                 seq_printf(seq, "%2d %04X:%04X:%02X %02X %08X:%08X %5d %lu "
 608                         "%d %pK %d%n",
 609                         sk->sk_protocol, pn->sobject, pn->dobject,
 610                         pn->resource, sk->sk_state,
 611                         sk_wmem_alloc_get(sk), sk_rmem_alloc_get(sk),
 612                         from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk)),
 613                         sock_i_ino(sk),
 614                         atomic_read(&sk->sk_refcnt), sk,
 615                         atomic_read(&sk->sk_drops), &len);
 616         }
 617         seq_printf(seq, "%*s\n", 127 - len, "");
 618         return 0;
 619 }
 620
 621 static const struct seq_operations pn_sock_seq_ops = {
 622         .start = pn_sock_seq_start,
 623         .next = pn_sock_seq_next,
 624         .stop = pn_sock_seq_stop,
 625         .show = pn_sock_seq_show,
 626 };
 627
 628 static int pn_sock_open(struct inode *inode, struct file *file)
 629 {
 630         return seq_open_net(inode, file, &pn_sock_seq_ops,
 631                                 sizeof(struct seq_net_private));
 632 }
 633
 634 const struct file_operations pn_sock_seq_fops = {
 635         .owner = THIS_MODULE,
 636         .open = pn_sock_open,
 637         .read = seq_read,
 638         .llseek = seq_lseek,
 639         .release = seq_release_net,
 640 };
 641 #endif
 642
 643 static struct  {
 644         struct sock *sk[256];
 645 } pnres;
 646
 647 /*
 648  * Find and hold socket based on resource.
 649  */
 650 struct sock *pn_find_sock_by_res(struct net *net, u8 res)
 651 {
 652         struct sock *sk;
 653
 654         if (!net_eq(net, &init_net))
 655                 return NULL;
 656
 657         rcu_read_lock();
 658         sk = rcu_dereference(pnres.sk[res]);
 659         if (sk)
 660                 sock_hold(sk);
 661         rcu_read_unlock();
 662         return sk;
 663 }
 664
 665 static DEFINE_MUTEX(resource_mutex);
 666
 667 int pn_sock_bind_res(struct sock *sk, u8 res)
 668 {
 669         int ret = -EADDRINUSE;
 670
 671         if (!net_eq(sock_net(sk), &init_net))
 672                 return -ENOIOCTLCMD;
 673         if (!capable(CAP_SYS_ADMIN))
 674                 return -EPERM;
 675         if (pn_socket_autobind(sk->sk_socket))
 676                 return -EAGAIN;
 677
 678         mutex_lock(&resource_mutex);
 679         if (pnres.sk[res] == NULL) {
 680                 sock_hold(sk);
 681                 rcu_assign_pointer(pnres.sk[res], sk);
 682                 ret = 0;
 683         }
 684         mutex_unlock(&resource_mutex);
 685         return ret;
 686 }
 687
 688 int pn_sock_unbind_res(struct sock *sk, u8 res)
 689 {
 690         int ret = -ENOENT;
 691
 692         if (!capable(CAP_SYS_ADMIN))
 693                 return -EPERM;
 694
 695         mutex_lock(&resource_mutex);
 696         if (pnres.sk[res] == sk) {
 697                 RCU_INIT_POINTER(pnres.sk[res], NULL);
 698                 ret = 0;
 699         }
 700         mutex_unlock(&resource_mutex);
 701
 702         if (ret == 0) {
 703                 synchronize_rcu();
 704                 sock_put(sk);
 705         }
 706         return ret;
 707 }
 708
 709 void pn_sock_unbind_all_res(struct sock *sk)
 710 {
 711         unsigned int res, match = 0;
 712
 713         mutex_lock(&resource_mutex);
 714         for (res = 0; res < 256; res++) {
 715                 if (pnres.sk[res] == sk) {
 716                         RCU_INIT_POINTER(pnres.sk[res], NULL);
 717                         match++;
 718                 }
 719         }
 720         mutex_unlock(&resource_mutex);
 721
 722         while (match > 0) {
 723                 __sock_put(sk);
 724                 match--;
 725         }
 726         /* Caller is responsible for RCU sync before final sock_put() */
 727 }
 728
 729 #ifdef CONFIG_PROC_FS
 730 static struct sock **pn_res_get_idx(struct seq_file *seq, loff_t pos)
 731 {
 732         struct net *net = seq_file_net(seq);
 733         unsigned int i;
 734
 735         if (!net_eq(net, &init_net))
 736                 return NULL;
 737
 738         for (i = 0; i < 256; i++) {
 739                 if (pnres.sk[i] == NULL)
 740                         continue;
 741                 if (!pos)
 742                         return pnres.sk + i;
 743                 pos--;
 744         }
 745         return NULL;
 746 }
 747
 748 static struct sock **pn_res_get_next(struct seq_file *seq, struct sock **sk)
 749 {
 750         struct net *net = seq_file_net(seq);
 751         unsigned int i;
 752
 753         BUG_ON(!net_eq(net, &init_net));
 754
 755         for (i = (sk - pnres.sk) + 1; i < 256; i++)
 756                 if (pnres.sk[i])
 757                         return pnres.sk + i;
 758         return NULL;
 759 }
 760
 761 static void *pn_res_seq_start(struct seq_file *seq, loff_t *pos)
 762         __acquires(resource_mutex)
 763 {
 764         mutex_lock(&resource_mutex);
 765         return *pos ? pn_res_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 766 }
 767
 768 static void *pn_res_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 769 {
 770         struct sock **sk;
 771
 772         if (v == SEQ_START_TOKEN)
 773                 sk = pn_res_get_idx(seq, 0);
 774         else
 775                 sk = pn_res_get_next(seq, v);
 776         (*pos)++;
 777         return sk;
 778 }
 779
 780 static void pn_res_seq_stop(struct seq_file *seq, void *v)
 781         __releases(resource_mutex)
 782 {
 783         mutex_unlock(&resource_mutex);
 784 }
 785
 786 static int pn_res_seq_show(struct seq_file *seq, void *v)
 787 {
 788         int len;
 789
 790         if (v == SEQ_START_TOKEN)
 791                 seq_printf(seq, "%s%n", "rs   uid inode", &len);
 792         else {
 793                 struct sock **psk = v;
 794                 struct sock *sk = *psk;
 795
 796                 seq_printf(seq, "%02X %5d %lu%n",
 797                            (int) (psk - pnres.sk),
 798                            from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk)),
 799                            sock_i_ino(sk), &len);
 800         }
 801         seq_printf(seq, "%*s\n", 63 - len, "");
 802         return 0;
 803 }
 804
 805 static const struct seq_operations pn_res_seq_ops = {
 806         .start = pn_res_seq_start,
 807         .next = pn_res_seq_next,
 808         .stop = pn_res_seq_stop,
 809         .show = pn_res_seq_show,
 810 };
 811
 812 static int pn_res_open(struct inode *inode, struct file *file)
 813 {
 814         return seq_open_net(inode, file, &pn_res_seq_ops,
 815                                 sizeof(struct seq_net_private));
 816 }
 817
 818 const struct file_operations pn_res_seq_fops = {
 819         .owner = THIS_MODULE,
 820         .open = pn_res_open,
 821         .read = seq_read,
 822         .llseek = seq_lseek,
 823         .release = seq_release_net,
 824 };
 825 #endif