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 <linux/sched/signal.h>
  31
  32 #include <net/sock.h>
  33 #include <net/tcp_states.h>
  34
  35 #include <linux/phonet.h>
  36 #include <linux/export.h>
  37 #include <net/phonet/phonet.h>
  38 #include <net/phonet/pep.h>
  39 #include <net/phonet/pn_dev.h>
  40
  41 static int pn_socket_release(struct socket *sock)
  42 {
  43         struct sock *sk = sock->sk;
  44
  45         if (sk) {
  46                 sock->sk = NULL;
  47                 sk->sk_prot->close(sk, 0);
  48         }
  49         return 0;
  50 }
  51
  52 #define PN_HASHSIZE     16
  53 #define PN_HASHMASK     (PN_HASHSIZE-1)
  54
  55
  56 static struct  {
  57         struct hlist_head hlist[PN_HASHSIZE];
  58         struct mutex lock;
  59 } pnsocks;
  60
  61 void __init pn_sock_init(void)
  62 {
  63         unsigned int i;
  64
  65         for (i = 0; i < PN_HASHSIZE; i++)
  66                 INIT_HLIST_HEAD(pnsocks.hlist + i);
  67         mutex_init(&pnsocks.lock);
  68 }
  69
  70 static struct hlist_head *pn_hash_list(u16 obj)
  71 {
  72         return pnsocks.hlist + (obj & PN_HASHMASK);
  73 }
  74
  75 /*
  76  * Find address based on socket address, match only certain fields.
  77  * Also grab sock if it was found. Remember to sock_put it later.
  78  */
  79 struct sock *pn_find_sock_by_sa(struct net *net, const struct sockaddr_pn *spn)
  80 {
  81         struct sock *sknode;
  82         struct sock *rval = NULL;
  83         u16 obj = pn_sockaddr_get_object(spn);
  84         u8 res = spn->spn_resource;
  85         struct hlist_head *hlist = pn_hash_list(obj);
  86
  87         rcu_read_lock();
  88         sk_for_each_rcu(sknode, hlist) {
  89                 struct pn_sock *pn = pn_sk(sknode);
  90                 BUG_ON(!pn->sobject); /* unbound socket */
  91
  92                 if (!net_eq(sock_net(sknode), net))
  93                         continue;
  94                 if (pn_port(obj)) {
  95                         /* Look up socket by port */
  96                         if (pn_port(pn->sobject) != pn_port(obj))
  97                                 continue;
  98                 } else {
  99                         /* If port is zero, look up by resource */
 100                         if (pn->resource != res)
 101                                 continue;
 102                 }
 103                 if (pn_addr(pn->sobject) &&
 104                     pn_addr(pn->sobject) != pn_addr(obj))
 105                         continue;
 106
 107                 rval = sknode;
 108                 sock_hold(sknode);
 109                 break;
 110         }
 111         rcu_read_unlock();
 112
 113         return rval;
 114 }
 115
 116 /* Deliver a broadcast packet (only in bottom-half) */
 117 void pn_deliver_sock_broadcast(struct net *net, struct sk_buff *skb)
 118 {
 119         struct hlist_head *hlist = pnsocks.hlist;
 120         unsigned int h;
 121
 122         rcu_read_lock();
 123         for (h = 0; h < PN_HASHSIZE; h++) {
 124                 struct sock *sknode;
 125
 126                 sk_for_each(sknode, hlist) {
 127                         struct sk_buff *clone;
 128
 129                         if (!net_eq(sock_net(sknode), net))
 130                                 continue;
 131                         if (!sock_flag(sknode, SOCK_BROADCAST))
 132                                 continue;
 133
 134                         clone = skb_clone(skb, GFP_ATOMIC);
 135                         if (clone) {
 136                                 sock_hold(sknode);
 137                                 sk_receive_skb(sknode, clone, 0);
 138                         }
 139                 }
 140                 hlist++;
 141         }
 142         rcu_read_unlock();
 143 }
 144
 145 int pn_sock_hash(struct sock *sk)
 146 {
 147         struct hlist_head *hlist = pn_hash_list(pn_sk(sk)->sobject);
 148
 149         mutex_lock(&pnsocks.lock);
 150         sk_add_node_rcu(sk, hlist);
 151         mutex_unlock(&pnsocks.lock);
 152
 153         return 0;
 154 }
 155 EXPORT_SYMBOL(pn_sock_hash);
 156
 157 void pn_sock_unhash(struct sock *sk)
 158 {
 159         mutex_lock(&pnsocks.lock);
 160         sk_del_node_init_rcu(sk);
 161         mutex_unlock(&pnsocks.lock);
 162         pn_sock_unbind_all_res(sk);
 163         synchronize_rcu();
 164 }
 165 EXPORT_SYMBOL(pn_sock_unhash);
 166
 167 static DEFINE_MUTEX(port_mutex);
 168
 169 static int pn_socket_bind(struct socket *sock, struct sockaddr *addr, int len)
 170 {
 171         struct sock *sk = sock->sk;
 172         struct pn_sock *pn = pn_sk(sk);
 173         struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
 174         int err;
 175         u16 handle;
 176         u8 saddr;
 177
 178         if (sk->sk_prot->bind)
 179                 return sk->sk_prot->bind(sk, addr, len);
 180
 181         if (len < sizeof(struct sockaddr_pn))
 182                 return -EINVAL;
 183         if (spn->spn_family != AF_PHONET)
 184                 return -EAFNOSUPPORT;
 185
 186         handle = pn_sockaddr_get_object((struct sockaddr_pn *)addr);
 187         saddr = pn_addr(handle);
 188         if (saddr && phonet_address_lookup(sock_net(sk), saddr))
 189                 return -EADDRNOTAVAIL;
 190
 191         lock_sock(sk);
 192         if (sk->sk_state != TCP_CLOSE || pn_port(pn->sobject)) {
 193                 err = -EINVAL; /* attempt to rebind */
 194                 goto out;
 195         }
 196         WARN_ON(sk_hashed(sk));
 197         mutex_lock(&port_mutex);
 198         err = sk->sk_prot->get_port(sk, pn_port(handle));
 199         if (err)
 200                 goto out_port;
 201
 202         /* get_port() sets the port, bind() sets the address if applicable */
 203         pn->sobject = pn_object(saddr, pn_port(pn->sobject));
 204         pn->resource = spn->spn_resource;
 205
 206         /* Enable RX on the socket */
 207         err = sk->sk_prot->hash(sk);
 208 out_port:
 209         mutex_unlock(&port_mutex);
 210 out:
 211         release_sock(sk);
 212         return err;
 213 }
 214
 215 static int pn_socket_autobind(struct socket *sock)
 216 {
 217         struct sockaddr_pn sa;
 218         int err;
 219
 220         memset(&sa, 0, sizeof(sa));
 221         sa.spn_family = AF_PHONET;
 222         err = pn_socket_bind(sock, (struct sockaddr *)&sa,
 223                                 sizeof(struct sockaddr_pn));
 224         if (err != -EINVAL)
 225                 return err;
 226         BUG_ON(!pn_port(pn_sk(sock->sk)->sobject));
 227         return 0; /* socket was already bound */
 228 }
 229
 230 static int pn_socket_connect(struct socket *sock, struct sockaddr *addr,
 231                 int len, int flags)
 232 {
 233         struct sock *sk = sock->sk;
 234         struct pn_sock *pn = pn_sk(sk);
 235         struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
 236         struct task_struct *tsk = current;
 237         long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
 238         int err;
 239
 240         if (pn_socket_autobind(sock))
 241                 return -ENOBUFS;
 242         if (len < sizeof(struct sockaddr_pn))
 243                 return -EINVAL;
 244         if (spn->spn_family != AF_PHONET)
 245                 return -EAFNOSUPPORT;
 246
 247         lock_sock(sk);
 248
 249         switch (sock->state) {
 250         case SS_UNCONNECTED:
 251                 if (sk->sk_state != TCP_CLOSE) {
 252                         err = -EISCONN;
 253                         goto out;
 254                 }
 255                 break;
 256         case SS_CONNECTING:
 257                 err = -EALREADY;
 258                 goto out;
 259         default:
 260                 err = -EISCONN;
 261                 goto out;
 262         }
 263
 264         pn->dobject = pn_sockaddr_get_object(spn);
 265         pn->resource = pn_sockaddr_get_resource(spn);
 266         sock->state = SS_CONNECTING;
 267
 268         err = sk->sk_prot->connect(sk, addr, len);
 269         if (err) {
 270                 sock->state = SS_UNCONNECTED;
 271                 pn->dobject = 0;
 272                 goto out;
 273         }
 274
 275         while (sk->sk_state == TCP_SYN_SENT) {
 276                 DEFINE_WAIT(wait);
 277
 278                 if (!timeo) {
 279                         err = -EINPROGRESS;
 280                         goto out;
 281                 }
 282                 if (signal_pending(tsk)) {
 283                         err = sock_intr_errno(timeo);
 284                         goto out;
 285                 }
 286
 287                 prepare_to_wait_exclusive(sk_sleep(sk), &wait,
 288                                                 TASK_INTERRUPTIBLE);
 289                 release_sock(sk);
 290                 timeo = schedule_timeout(timeo);
 291                 lock_sock(sk);
 292                 finish_wait(sk_sleep(sk), &wait);
 293         }
 294
 295         if ((1 << sk->sk_state) & (TCPF_SYN_RECV|TCPF_ESTABLISHED))
 296                 err = 0;
 297         else if (sk->sk_state == TCP_CLOSE_WAIT)
 298                 err = -ECONNRESET;
 299         else
 300                 err = -ECONNREFUSED;
 301         sock->state = err ? SS_UNCONNECTED : SS_CONNECTED;
 302 out:
 303         release_sock(sk);
 304         return err;
 305 }
 306
 307 static int pn_socket_accept(struct socket *sock, struct socket *newsock,
 308                                 int flags)
 309 {
 310         struct sock *sk = sock->sk;
 311         struct sock *newsk;
 312         int err;
 313
 314         if (unlikely(sk->sk_state != TCP_LISTEN))
 315                 return -EINVAL;
 316
 317         newsk = sk->sk_prot->accept(sk, flags, &err);
 318         if (!newsk)
 319                 return err;
 320
 321         lock_sock(newsk);
 322         sock_graft(newsk, newsock);
 323         newsock->state = SS_CONNECTED;
 324         release_sock(newsk);
 325         return 0;
 326 }
 327
 328 static int pn_socket_getname(struct socket *sock, struct sockaddr *addr,
 329                                 int *sockaddr_len, int peer)
 330 {
 331         struct sock *sk = sock->sk;
 332         struct pn_sock *pn = pn_sk(sk);
 333
 334         memset(addr, 0, sizeof(struct sockaddr_pn));
 335         addr->sa_family = AF_PHONET;
 336         if (!peer) /* Race with bind() here is userland's problem. */
 337                 pn_sockaddr_set_object((struct sockaddr_pn *)addr,
 338                                         pn->sobject);
 339
 340         *sockaddr_len = sizeof(struct sockaddr_pn);
 341         return 0;
 342 }
 343
 344 static unsigned int pn_socket_poll(struct file *file, struct socket *sock,
 345                                         poll_table *wait)
 346 {
 347         struct sock *sk = sock->sk;
 348         struct pep_sock *pn = pep_sk(sk);
 349         unsigned int mask = 0;
 350
 351         poll_wait(file, sk_sleep(sk), wait);
 352
 353         if (sk->sk_state == TCP_CLOSE)
 354                 return POLLERR;
 355         if (!skb_queue_empty(&sk->sk_receive_queue))
 356                 mask |= POLLIN | POLLRDNORM;
 357         if (!skb_queue_empty(&pn->ctrlreq_queue))
 358                 mask |= POLLPRI;
 359         if (!mask && sk->sk_state == TCP_CLOSE_WAIT)
 360                 return POLLHUP;
 361
 362         if (sk->sk_state == TCP_ESTABLISHED &&
 363                 atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf &&
 364                 atomic_read(&pn->tx_credits))
 365                 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
 366
 367         return mask;
 368 }
 369
 370 static int pn_socket_ioctl(struct socket *sock, unsigned int cmd,
 371                                 unsigned long arg)
 372 {
 373         struct sock *sk = sock->sk;
 374         struct pn_sock *pn = pn_sk(sk);
 375
 376         if (cmd == SIOCPNGETOBJECT) {
 377                 struct net_device *dev;
 378                 u16 handle;
 379                 u8 saddr;
 380
 381                 if (get_user(handle, (__u16 __user *)arg))
 382                         return -EFAULT;
 383
 384                 lock_sock(sk);
 385                 if (sk->sk_bound_dev_if)
 386                         dev = dev_get_by_index(sock_net(sk),
 387                                                 sk->sk_bound_dev_if);
 388                 else
 389                         dev = phonet_device_get(sock_net(sk));
 390                 if (dev && (dev->flags & IFF_UP))
 391                         saddr = phonet_address_get(dev, pn_addr(handle));
 392                 else
 393                         saddr = PN_NO_ADDR;
 394                 release_sock(sk);
 395
 396                 if (dev)
 397                         dev_put(dev);
 398                 if (saddr == PN_NO_ADDR)
 399                         return -EHOSTUNREACH;
 400
 401                 handle = pn_object(saddr, pn_port(pn->sobject));
 402                 return put_user(handle, (__u16 __user *)arg);
 403         }
 404
 405         return sk->sk_prot->ioctl(sk, cmd, arg);
 406 }
 407
 408 static int pn_socket_listen(struct socket *sock, int backlog)
 409 {
 410         struct sock *sk = sock->sk;
 411         int err = 0;
 412
 413         if (pn_socket_autobind(sock))
 414                 return -ENOBUFS;
 415
 416         lock_sock(sk);
 417         if (sock->state != SS_UNCONNECTED) {
 418                 err = -EINVAL;
 419                 goto out;
 420         }
 421
 422         if (sk->sk_state != TCP_LISTEN) {
 423                 sk->sk_state = TCP_LISTEN;
 424                 sk->sk_ack_backlog = 0;
 425         }
 426         sk->sk_max_ack_backlog = backlog;
 427 out:
 428         release_sock(sk);
 429         return err;
 430 }
 431
 432 static int pn_socket_sendmsg(struct socket *sock, struct msghdr *m,
 433                              size_t total_len)
 434 {
 435         struct sock *sk = sock->sk;
 436
 437         if (pn_socket_autobind(sock))
 438                 return -EAGAIN;
 439
 440         return sk->sk_prot->sendmsg(sk, m, total_len);
 441 }
 442
 443 const struct proto_ops phonet_dgram_ops = {
 444         .family         = AF_PHONET,
 445         .owner          = THIS_MODULE,
 446         .release        = pn_socket_release,
 447         .bind           = pn_socket_bind,
 448         .connect        = sock_no_connect,
 449         .socketpair     = sock_no_socketpair,
 450         .accept         = sock_no_accept,
 451         .getname        = pn_socket_getname,
 452         .poll           = datagram_poll,
 453         .ioctl          = pn_socket_ioctl,
 454         .listen         = sock_no_listen,
 455         .shutdown       = sock_no_shutdown,
 456         .setsockopt     = sock_no_setsockopt,
 457         .getsockopt     = sock_no_getsockopt,
 458 #ifdef CONFIG_COMPAT
 459         .compat_setsockopt = sock_no_setsockopt,
 460         .compat_getsockopt = sock_no_getsockopt,
 461 #endif
 462         .sendmsg        = pn_socket_sendmsg,
 463         .recvmsg        = sock_common_recvmsg,
 464         .mmap           = sock_no_mmap,
 465         .sendpage       = sock_no_sendpage,
 466 };
 467
 468 const struct proto_ops phonet_stream_ops = {
 469         .family         = AF_PHONET,
 470         .owner          = THIS_MODULE,
 471         .release        = pn_socket_release,
 472         .bind           = pn_socket_bind,
 473         .connect        = pn_socket_connect,
 474         .socketpair     = sock_no_socketpair,
 475         .accept         = pn_socket_accept,
 476         .getname        = pn_socket_getname,
 477         .poll           = pn_socket_poll,
 478         .ioctl          = pn_socket_ioctl,
 479         .listen         = pn_socket_listen,
 480         .shutdown       = sock_no_shutdown,
 481         .setsockopt     = sock_common_setsockopt,
 482         .getsockopt     = sock_common_getsockopt,
 483 #ifdef CONFIG_COMPAT
 484         .compat_setsockopt = compat_sock_common_setsockopt,
 485         .compat_getsockopt = compat_sock_common_getsockopt,
 486 #endif
 487         .sendmsg        = pn_socket_sendmsg,
 488         .recvmsg        = sock_common_recvmsg,
 489         .mmap           = sock_no_mmap,
 490         .sendpage       = sock_no_sendpage,
 491 };
 492 EXPORT_SYMBOL(phonet_stream_ops);
 493
 494 /* allocate port for a socket */
 495 int pn_sock_get_port(struct sock *sk, unsigned short sport)
 496 {
 497         static int port_cur;
 498         struct net *net = sock_net(sk);
 499         struct pn_sock *pn = pn_sk(sk);
 500         struct sockaddr_pn try_sa;
 501         struct sock *tmpsk;
 502
 503         memset(&try_sa, 0, sizeof(struct sockaddr_pn));
 504         try_sa.spn_family = AF_PHONET;
 505         WARN_ON(!mutex_is_locked(&port_mutex));
 506         if (!sport) {
 507                 /* search free port */
 508                 int port, pmin, pmax;
 509
 510                 phonet_get_local_port_range(&pmin, &pmax);
 511                 for (port = pmin; port <= pmax; port++) {
 512                         port_cur++;
 513                         if (port_cur < pmin || port_cur > pmax)
 514                                 port_cur = pmin;
 515
 516                         pn_sockaddr_set_port(&try_sa, port_cur);
 517                         tmpsk = pn_find_sock_by_sa(net, &try_sa);
 518                         if (tmpsk == NULL) {
 519                                 sport = port_cur;
 520                                 goto found;
 521                         } else
 522                                 sock_put(tmpsk);
 523                 }
 524         } else {
 525                 /* try to find specific port */
 526                 pn_sockaddr_set_port(&try_sa, sport);
 527                 tmpsk = pn_find_sock_by_sa(net, &try_sa);
 528                 if (tmpsk == NULL)
 529                         /* No sock there! We can use that port... */
 530                         goto found;
 531                 else
 532                         sock_put(tmpsk);
 533         }
 534         /* the port must be in use already */
 535         return -EADDRINUSE;
 536
 537 found:
 538         pn->sobject = pn_object(pn_addr(pn->sobject), sport);
 539         return 0;
 540 }
 541 EXPORT_SYMBOL(pn_sock_get_port);
 542
 543 #ifdef CONFIG_PROC_FS
 544 static struct sock *pn_sock_get_idx(struct seq_file *seq, loff_t pos)
 545 {
 546         struct net *net = seq_file_net(seq);
 547         struct hlist_head *hlist = pnsocks.hlist;
 548         struct sock *sknode;
 549         unsigned int h;
 550
 551         for (h = 0; h < PN_HASHSIZE; h++) {
 552                 sk_for_each_rcu(sknode, hlist) {
 553                         if (!net_eq(net, sock_net(sknode)))
 554                                 continue;
 555                         if (!pos)
 556                                 return sknode;
 557                         pos--;
 558                 }
 559                 hlist++;
 560         }
 561         return NULL;
 562 }
 563
 564 static struct sock *pn_sock_get_next(struct seq_file *seq, struct sock *sk)
 565 {
 566         struct net *net = seq_file_net(seq);
 567
 568         do
 569                 sk = sk_next(sk);
 570         while (sk && !net_eq(net, sock_net(sk)));
 571
 572         return sk;
 573 }
 574
 575 static void *pn_sock_seq_start(struct seq_file *seq, loff_t *pos)
 576         __acquires(rcu)
 577 {
 578         rcu_read_lock();
 579         return *pos ? pn_sock_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 580 }
 581
 582 static void *pn_sock_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 583 {
 584         struct sock *sk;
 585
 586         if (v == SEQ_START_TOKEN)
 587                 sk = pn_sock_get_idx(seq, 0);
 588         else
 589                 sk = pn_sock_get_next(seq, v);
 590         (*pos)++;
 591         return sk;
 592 }
 593
 594 static void pn_sock_seq_stop(struct seq_file *seq, void *v)
 595         __releases(rcu)
 596 {
 597         rcu_read_unlock();
 598 }
 599
 600 static int pn_sock_seq_show(struct seq_file *seq, void *v)
 601 {
 602         seq_setwidth(seq, 127);
 603         if (v == SEQ_START_TOKEN)
 604                 seq_puts(seq, "pt  loc  rem rs st tx_queue rx_queue "
 605                         "  uid inode ref pointer drops");
 606         else {
 607                 struct sock *sk = v;
 608                 struct pn_sock *pn = pn_sk(sk);
 609
 610                 seq_printf(seq, "%2d %04X:%04X:%02X %02X %08X:%08X %5d %lu "
 611                         "%d %pK %d",
 612                         sk->sk_protocol, pn->sobject, pn->dobject,
 613                         pn->resource, sk->sk_state,
 614                         sk_wmem_alloc_get(sk), sk_rmem_alloc_get(sk),
 615                         from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk)),
 616                         sock_i_ino(sk),
 617                         atomic_read(&sk->sk_refcnt), sk,
 618                         atomic_read(&sk->sk_drops));
 619         }
 620         seq_pad(seq, '\n');
 621         return 0;
 622 }
 623
 624 static const struct seq_operations pn_sock_seq_ops = {
 625         .start = pn_sock_seq_start,
 626         .next = pn_sock_seq_next,
 627         .stop = pn_sock_seq_stop,
 628         .show = pn_sock_seq_show,
 629 };
 630
 631 static int pn_sock_open(struct inode *inode, struct file *file)
 632 {
 633         return seq_open_net(inode, file, &pn_sock_seq_ops,
 634                                 sizeof(struct seq_net_private));
 635 }
 636
 637 const struct file_operations pn_sock_seq_fops = {
 638         .owner = THIS_MODULE,
 639         .open = pn_sock_open,
 640         .read = seq_read,
 641         .llseek = seq_lseek,
 642         .release = seq_release_net,
 643 };
 644 #endif
 645
 646 static struct  {
 647         struct sock *sk[256];
 648 } pnres;
 649
 650 /*
 651  * Find and hold socket based on resource.
 652  */
 653 struct sock *pn_find_sock_by_res(struct net *net, u8 res)
 654 {
 655         struct sock *sk;
 656
 657         if (!net_eq(net, &init_net))
 658                 return NULL;
 659
 660         rcu_read_lock();
 661         sk = rcu_dereference(pnres.sk[res]);
 662         if (sk)
 663                 sock_hold(sk);
 664         rcu_read_unlock();
 665         return sk;
 666 }
 667
 668 static DEFINE_MUTEX(resource_mutex);
 669
 670 int pn_sock_bind_res(struct sock *sk, u8 res)
 671 {
 672         int ret = -EADDRINUSE;
 673
 674         if (!net_eq(sock_net(sk), &init_net))
 675                 return -ENOIOCTLCMD;
 676         if (!capable(CAP_SYS_ADMIN))
 677                 return -EPERM;
 678         if (pn_socket_autobind(sk->sk_socket))
 679                 return -EAGAIN;
 680
 681         mutex_lock(&resource_mutex);
 682         if (pnres.sk[res] == NULL) {
 683                 sock_hold(sk);
 684                 rcu_assign_pointer(pnres.sk[res], sk);
 685                 ret = 0;
 686         }
 687         mutex_unlock(&resource_mutex);
 688         return ret;
 689 }
 690
 691 int pn_sock_unbind_res(struct sock *sk, u8 res)
 692 {
 693         int ret = -ENOENT;
 694
 695         if (!capable(CAP_SYS_ADMIN))
 696                 return -EPERM;
 697
 698         mutex_lock(&resource_mutex);
 699         if (pnres.sk[res] == sk) {
 700                 RCU_INIT_POINTER(pnres.sk[res], NULL);
 701                 ret = 0;
 702         }
 703         mutex_unlock(&resource_mutex);
 704
 705         if (ret == 0) {
 706                 synchronize_rcu();
 707                 sock_put(sk);
 708         }
 709         return ret;
 710 }
 711
 712 void pn_sock_unbind_all_res(struct sock *sk)
 713 {
 714         unsigned int res, match = 0;
 715
 716         mutex_lock(&resource_mutex);
 717         for (res = 0; res < 256; res++) {
 718                 if (pnres.sk[res] == sk) {
 719                         RCU_INIT_POINTER(pnres.sk[res], NULL);
 720                         match++;
 721                 }
 722         }
 723         mutex_unlock(&resource_mutex);
 724
 725         while (match > 0) {
 726                 __sock_put(sk);
 727                 match--;
 728         }
 729         /* Caller is responsible for RCU sync before final sock_put() */
 730 }
 731
 732 #ifdef CONFIG_PROC_FS
 733 static struct sock **pn_res_get_idx(struct seq_file *seq, loff_t pos)
 734 {
 735         struct net *net = seq_file_net(seq);
 736         unsigned int i;
 737
 738         if (!net_eq(net, &init_net))
 739                 return NULL;
 740
 741         for (i = 0; i < 256; i++) {
 742                 if (pnres.sk[i] == NULL)
 743                         continue;
 744                 if (!pos)
 745                         return pnres.sk + i;
 746                 pos--;
 747         }
 748         return NULL;
 749 }
 750
 751 static struct sock **pn_res_get_next(struct seq_file *seq, struct sock **sk)
 752 {
 753         struct net *net = seq_file_net(seq);
 754         unsigned int i;
 755
 756         BUG_ON(!net_eq(net, &init_net));
 757
 758         for (i = (sk - pnres.sk) + 1; i < 256; i++)
 759                 if (pnres.sk[i])
 760                         return pnres.sk + i;
 761         return NULL;
 762 }
 763
 764 static void *pn_res_seq_start(struct seq_file *seq, loff_t *pos)
 765         __acquires(resource_mutex)
 766 {
 767         mutex_lock(&resource_mutex);
 768         return *pos ? pn_res_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 769 }
 770
 771 static void *pn_res_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 772 {
 773         struct sock **sk;
 774
 775         if (v == SEQ_START_TOKEN)
 776                 sk = pn_res_get_idx(seq, 0);
 777         else
 778                 sk = pn_res_get_next(seq, v);
 779         (*pos)++;
 780         return sk;
 781 }
 782
 783 static void pn_res_seq_stop(struct seq_file *seq, void *v)
 784         __releases(resource_mutex)
 785 {
 786         mutex_unlock(&resource_mutex);
 787 }
 788
 789 static int pn_res_seq_show(struct seq_file *seq, void *v)
 790 {
 791         seq_setwidth(seq, 63);
 792         if (v == SEQ_START_TOKEN)
 793                 seq_puts(seq, "rs   uid inode");
 794         else {
 795                 struct sock **psk = v;
 796                 struct sock *sk = *psk;
 797
 798                 seq_printf(seq, "%02X %5u %lu",
 799                            (int) (psk - pnres.sk),
 800                            from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk)),
 801                            sock_i_ino(sk));
 802         }
 803         seq_pad(seq, '\n');
 804         return 0;
 805 }
 806
 807 static const struct seq_operations pn_res_seq_ops = {
 808         .start = pn_res_seq_start,
 809         .next = pn_res_seq_next,
 810         .stop = pn_res_seq_stop,
 811         .show = pn_res_seq_show,
 812 };
 813
 814 static int pn_res_open(struct inode *inode, struct file *file)
 815 {
 816         return seq_open_net(inode, file, &pn_res_seq_ops,
 817                                 sizeof(struct seq_net_private));
 818 }
 819
 820 const struct file_operations pn_res_seq_fops = {
 821         .owner = THIS_MODULE,
 822         .open = pn_res_open,
 823         .read = seq_read,
 824         .llseek = seq_lseek,
 825         .release = seq_release_net,
 826 };
 827 #endif