net/phonet/socket.c

   1 /*
   2  * File: socket.c
   3  *
   4  * Phonet sockets
   5  *
   6  * Copyright (C) 2008 Nokia Corporation.
   7  *
   8  * Contact: Remi Denis-Courmont <remi.denis-courmont@nokia.com>
   9  * Original author: Sakari Ailus <sakari.ailus@nokia.com>
  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 <net/phonet/phonet.h>
  35 #include <net/phonet/pep.h>
  36 #include <net/phonet/pn_dev.h>
  37
  38 static int pn_socket_release(struct socket *sock)
  39 {
  40         struct sock *sk = sock->sk;
  41
  42         if (sk) {
  43                 sock->sk = NULL;
  44                 sk->sk_prot->close(sk, 0);
  45         }
  46         return 0;
  47 }
  48
  49 #define PN_HASHSIZE     16
  50 #define PN_HASHMASK     (PN_HASHSIZE-1)
  51
  52
  53 static struct  {
  54         struct hlist_head hlist[PN_HASHSIZE];
  55         spinlock_t lock;
  56 } pnsocks;
  57
  58 void __init pn_sock_init(void)
  59 {
  60         unsigned i;
  61
  62         for (i = 0; i < PN_HASHSIZE; i++)
  63                 INIT_HLIST_HEAD(pnsocks.hlist + i);
  64         spin_lock_init(&pnsocks.lock);
  65 }
  66
  67 static struct hlist_head *pn_hash_list(u16 obj)
  68 {
  69         return pnsocks.hlist + (obj & PN_HASHMASK);
  70 }
  71
  72 /*
  73  * Find address based on socket address, match only certain fields.
  74  * Also grab sock if it was found. Remember to sock_put it later.
  75  */
  76 struct sock *pn_find_sock_by_sa(struct net *net, const struct sockaddr_pn *spn)
  77 {
  78         struct hlist_node *node;
  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         spin_lock_bh(&pnsocks.lock);
  86
  87         sk_for_each(sknode, node, hlist) {
  88                 struct pn_sock *pn = pn_sk(sknode);
  89                 BUG_ON(!pn->sobject); /* unbound socket */
  90
  91                 if (!net_eq(sock_net(sknode), net))
  92                         continue;
  93                 if (pn_port(obj)) {
  94                         /* Look up socket by port */
  95                         if (pn_port(pn->sobject) != pn_port(obj))
  96                                 continue;
  97                 } else {
  98                         /* If port is zero, look up by resource */
  99                         if (pn->resource != res)
 100                                 continue;
 101                 }
 102                 if (pn_addr(pn->sobject) &&
 103                     pn_addr(pn->sobject) != pn_addr(obj))
 104                         continue;
 105
 106                 rval = sknode;
 107                 sock_hold(sknode);
 108                 break;
 109         }
 110
 111         spin_unlock_bh(&pnsocks.lock);
 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 h;
 121
 122         spin_lock(&pnsocks.lock);
 123         for (h = 0; h < PN_HASHSIZE; h++) {
 124                 struct hlist_node *node;
 125                 struct sock *sknode;
 126
 127                 sk_for_each(sknode, node, hlist) {
 128                         struct sk_buff *clone;
 129
 130                         if (!net_eq(sock_net(sknode), net))
 131                                 continue;
 132                         if (!sock_flag(sknode, SOCK_BROADCAST))
 133                                 continue;
 134
 135                         clone = skb_clone(skb, GFP_ATOMIC);
 136                         if (clone) {
 137                                 sock_hold(sknode);
 138                                 sk_receive_skb(sknode, clone, 0);
 139                         }
 140                 }
 141                 hlist++;
 142         }
 143         spin_unlock(&pnsocks.lock);
 144 }
 145
 146 void pn_sock_hash(struct sock *sk)
 147 {
 148         struct hlist_head *hlist = pn_hash_list(pn_sk(sk)->sobject);
 149
 150         spin_lock_bh(&pnsocks.lock);
 151         sk_add_node(sk, hlist);
 152         spin_unlock_bh(&pnsocks.lock);
 153 }
 154 EXPORT_SYMBOL(pn_sock_hash);
 155
 156 void pn_sock_unhash(struct sock *sk)
 157 {
 158         spin_lock_bh(&pnsocks.lock);
 159         sk_del_node_init(sk);
 160         spin_unlock_bh(&pnsocks.lock);
 161         pn_sock_unbind_all_res(sk);
 162 }
 163 EXPORT_SYMBOL(pn_sock_unhash);
 164
 165 static DEFINE_MUTEX(port_mutex);
 166
 167 static int pn_socket_bind(struct socket *sock, struct sockaddr *addr, int len)
 168 {
 169         struct sock *sk = sock->sk;
 170         struct pn_sock *pn = pn_sk(sk);
 171         struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
 172         int err;
 173         u16 handle;
 174         u8 saddr;
 175
 176         if (sk->sk_prot->bind)
 177                 return sk->sk_prot->bind(sk, addr, len);
 178
 179         if (len < sizeof(struct sockaddr_pn))
 180                 return -EINVAL;
 181         if (spn->spn_family != AF_PHONET)
 182                 return -EAFNOSUPPORT;
 183
 184         handle = pn_sockaddr_get_object((struct sockaddr_pn *)addr);
 185         saddr = pn_addr(handle);
 186         if (saddr && phonet_address_lookup(sock_net(sk), saddr))
 187                 return -EADDRNOTAVAIL;
 188
 189         lock_sock(sk);
 190         if (sk->sk_state != TCP_CLOSE || pn_port(pn->sobject)) {
 191                 err = -EINVAL; /* attempt to rebind */
 192                 goto out;
 193         }
 194         WARN_ON(sk_hashed(sk));
 195         mutex_lock(&port_mutex);
 196         err = sk->sk_prot->get_port(sk, pn_port(handle));
 197         if (err)
 198                 goto out_port;
 199
 200         /* get_port() sets the port, bind() sets the address if applicable */
 201         pn->sobject = pn_object(saddr, pn_port(pn->sobject));
 202         pn->resource = spn->spn_resource;
 203
 204         /* Enable RX on the socket */
 205         sk->sk_prot->hash(sk);
 206 out_port:
 207         mutex_unlock(&port_mutex);
 208 out:
 209         release_sock(sk);
 210         return err;
 211 }
 212
 213 static int pn_socket_autobind(struct socket *sock)
 214 {
 215         struct sockaddr_pn sa;
 216         int err;
 217
 218         memset(&sa, 0, sizeof(sa));
 219         sa.spn_family = AF_PHONET;
 220         err = pn_socket_bind(sock, (struct sockaddr *)&sa,
 221                                 sizeof(struct sockaddr_pn));
 222         if (err != -EINVAL)
 223                 return err;
 224         BUG_ON(!pn_port(pn_sk(sock->sk)->sobject));
 225         return 0; /* socket was already bound */
 226 }
 227
 228 #ifdef CONFIG_PHONET_PIPECTRLR
 229 static int pn_socket_connect(struct socket *sock, struct sockaddr *addr,
 230                 int len, int flags)
 231 {
 232         struct sock *sk = sock->sk;
 233         struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
 234         long timeo;
 235         int err;
 236
 237         if (len < sizeof(struct sockaddr_pn))
 238                 return -EINVAL;
 239         if (spn->spn_family != AF_PHONET)
 240                 return -EAFNOSUPPORT;
 241
 242         lock_sock(sk);
 243
 244         switch (sock->state) {
 245         case SS_UNCONNECTED:
 246                 sk->sk_state = TCP_CLOSE;
 247                 break;
 248         case SS_CONNECTING:
 249                 switch (sk->sk_state) {
 250                 case TCP_SYN_RECV:
 251                         sock->state = SS_CONNECTED;
 252                         err = -EISCONN;
 253                         goto out;
 254                 case TCP_CLOSE:
 255                         err = -EALREADY;
 256                         if (flags & O_NONBLOCK)
 257                                 goto out;
 258                         goto wait_connect;
 259                 }
 260                 break;
 261         case SS_CONNECTED:
 262                 switch (sk->sk_state) {
 263                 case TCP_SYN_RECV:
 264                         err = -EISCONN;
 265                         goto out;
 266                 case TCP_CLOSE:
 267                         sock->state = SS_UNCONNECTED;
 268                         break;
 269                 }
 270                 break;
 271         case SS_DISCONNECTING:
 272         case SS_FREE:
 273                 break;
 274         }
 275         sk->sk_state = TCP_CLOSE;
 276         sk_stream_kill_queues(sk);
 277
 278         sock->state = SS_CONNECTING;
 279         err = sk->sk_prot->connect(sk, addr, len);
 280         if (err < 0) {
 281                 sock->state = SS_UNCONNECTED;
 282                 sk->sk_state = TCP_CLOSE;
 283                 goto out;
 284         }
 285
 286         err = -EINPROGRESS;
 287 wait_connect:
 288         if (sk->sk_state != TCP_SYN_RECV && (flags & O_NONBLOCK))
 289                 goto out;
 290
 291         timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
 292         release_sock(sk);
 293
 294         err = -ERESTARTSYS;
 295         timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
 296                         sk->sk_state != TCP_CLOSE,
 297                         timeo);
 298
 299         lock_sock(sk);
 300         if (timeo < 0)
 301                 goto out; /* -ERESTARTSYS */
 302
 303         err = -ETIMEDOUT;
 304         if (timeo == 0 && sk->sk_state != TCP_SYN_RECV)
 305                 goto out;
 306
 307         if (sk->sk_state != TCP_SYN_RECV) {
 308                 sock->state = SS_UNCONNECTED;
 309                 err = sock_error(sk);
 310                 if (!err)
 311                         err = -ECONNREFUSED;
 312                 goto out;
 313         }
 314         sock->state = SS_CONNECTED;
 315         err = 0;
 316
 317 out:
 318         release_sock(sk);
 319         return err;
 320 }
 321 #endif
 322
 323 static int pn_socket_accept(struct socket *sock, struct socket *newsock,
 324                                 int flags)
 325 {
 326         struct sock *sk = sock->sk;
 327         struct sock *newsk;
 328         int err;
 329
 330         newsk = sk->sk_prot->accept(sk, flags, &err);
 331         if (!newsk)
 332                 return err;
 333
 334         lock_sock(newsk);
 335         sock_graft(newsk, newsock);
 336         newsock->state = SS_CONNECTED;
 337         release_sock(newsk);
 338         return 0;
 339 }
 340
 341 static int pn_socket_getname(struct socket *sock, struct sockaddr *addr,
 342                                 int *sockaddr_len, int peer)
 343 {
 344         struct sock *sk = sock->sk;
 345         struct pn_sock *pn = pn_sk(sk);
 346
 347         memset(addr, 0, sizeof(struct sockaddr_pn));
 348         addr->sa_family = AF_PHONET;
 349         if (!peer) /* Race with bind() here is userland's problem. */
 350                 pn_sockaddr_set_object((struct sockaddr_pn *)addr,
 351                                         pn->sobject);
 352
 353         *sockaddr_len = sizeof(struct sockaddr_pn);
 354         return 0;
 355 }
 356
 357 static unsigned int pn_socket_poll(struct file *file, struct socket *sock,
 358                                         poll_table *wait)
 359 {
 360         struct sock *sk = sock->sk;
 361         struct pep_sock *pn = pep_sk(sk);
 362         unsigned int mask = 0;
 363
 364         poll_wait(file, sk_sleep(sk), wait);
 365
 366         switch (sk->sk_state) {
 367         case TCP_LISTEN:
 368                 return hlist_empty(&pn->ackq) ? 0 : POLLIN;
 369         case TCP_CLOSE:
 370                 return POLLERR;
 371         }
 372
 373         if (!skb_queue_empty(&sk->sk_receive_queue))
 374                 mask |= POLLIN | POLLRDNORM;
 375         if (!skb_queue_empty(&pn->ctrlreq_queue))
 376                 mask |= POLLPRI;
 377         if (!mask && sk->sk_state == TCP_CLOSE_WAIT)
 378                 return POLLHUP;
 379
 380         if (sk->sk_state == TCP_ESTABLISHED &&
 381                 atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf &&
 382                 atomic_read(&pn->tx_credits))
 383                 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
 384
 385         return mask;
 386 }
 387
 388 static int pn_socket_ioctl(struct socket *sock, unsigned int cmd,
 389                                 unsigned long arg)
 390 {
 391         struct sock *sk = sock->sk;
 392         struct pn_sock *pn = pn_sk(sk);
 393
 394         if (cmd == SIOCPNGETOBJECT) {
 395                 struct net_device *dev;
 396                 u16 handle;
 397                 u8 saddr;
 398
 399                 if (get_user(handle, (__u16 __user *)arg))
 400                         return -EFAULT;
 401
 402                 lock_sock(sk);
 403                 if (sk->sk_bound_dev_if)
 404                         dev = dev_get_by_index(sock_net(sk),
 405                                                 sk->sk_bound_dev_if);
 406                 else
 407                         dev = phonet_device_get(sock_net(sk));
 408                 if (dev && (dev->flags & IFF_UP))
 409                         saddr = phonet_address_get(dev, pn_addr(handle));
 410                 else
 411                         saddr = PN_NO_ADDR;
 412                 release_sock(sk);
 413
 414                 if (dev)
 415                         dev_put(dev);
 416                 if (saddr == PN_NO_ADDR)
 417                         return -EHOSTUNREACH;
 418
 419                 handle = pn_object(saddr, pn_port(pn->sobject));
 420                 return put_user(handle, (__u16 __user *)arg);
 421         }
 422
 423         return sk->sk_prot->ioctl(sk, cmd, arg);
 424 }
 425
 426 static int pn_socket_listen(struct socket *sock, int backlog)
 427 {
 428         struct sock *sk = sock->sk;
 429         int err = 0;
 430
 431         if (sock->state != SS_UNCONNECTED)
 432                 return -EINVAL;
 433         if (pn_socket_autobind(sock))
 434                 return -ENOBUFS;
 435
 436         lock_sock(sk);
 437         if (sk->sk_state != TCP_CLOSE) {
 438                 err = -EINVAL;
 439                 goto out;
 440         }
 441
 442         sk->sk_state = TCP_LISTEN;
 443         sk->sk_ack_backlog = 0;
 444         sk->sk_max_ack_backlog = backlog;
 445 out:
 446         release_sock(sk);
 447         return err;
 448 }
 449
 450 static int pn_socket_sendmsg(struct kiocb *iocb, struct socket *sock,
 451                                 struct msghdr *m, size_t total_len)
 452 {
 453         struct sock *sk = sock->sk;
 454
 455         if (pn_socket_autobind(sock))
 456                 return -EAGAIN;
 457
 458         return sk->sk_prot->sendmsg(iocb, sk, m, total_len);
 459 }
 460
 461 const struct proto_ops phonet_dgram_ops = {
 462         .family         = AF_PHONET,
 463         .owner          = THIS_MODULE,
 464         .release        = pn_socket_release,
 465         .bind           = pn_socket_bind,
 466         .connect        = sock_no_connect,
 467         .socketpair     = sock_no_socketpair,
 468         .accept         = sock_no_accept,
 469         .getname        = pn_socket_getname,
 470         .poll           = datagram_poll,
 471         .ioctl          = pn_socket_ioctl,
 472         .listen         = sock_no_listen,
 473         .shutdown       = sock_no_shutdown,
 474         .setsockopt     = sock_no_setsockopt,
 475         .getsockopt     = sock_no_getsockopt,
 476 #ifdef CONFIG_COMPAT
 477         .compat_setsockopt = sock_no_setsockopt,
 478         .compat_getsockopt = sock_no_getsockopt,
 479 #endif
 480         .sendmsg        = pn_socket_sendmsg,
 481         .recvmsg        = sock_common_recvmsg,
 482         .mmap           = sock_no_mmap,
 483         .sendpage       = sock_no_sendpage,
 484 };
 485
 486 const struct proto_ops phonet_stream_ops = {
 487         .family         = AF_PHONET,
 488         .owner          = THIS_MODULE,
 489         .release        = pn_socket_release,
 490         .bind           = pn_socket_bind,
 491 #ifdef CONFIG_PHONET_PIPECTRLR
 492         .connect        = pn_socket_connect,
 493 #else
 494         .connect        = sock_no_connect,
 495 #endif
 496         .socketpair     = sock_no_socketpair,
 497         .accept         = pn_socket_accept,
 498         .getname        = pn_socket_getname,
 499         .poll           = pn_socket_poll,
 500         .ioctl          = pn_socket_ioctl,
 501         .listen         = pn_socket_listen,
 502         .shutdown       = sock_no_shutdown,
 503         .setsockopt     = sock_common_setsockopt,
 504         .getsockopt     = sock_common_getsockopt,
 505 #ifdef CONFIG_COMPAT
 506         .compat_setsockopt = compat_sock_common_setsockopt,
 507         .compat_getsockopt = compat_sock_common_getsockopt,
 508 #endif
 509         .sendmsg        = pn_socket_sendmsg,
 510         .recvmsg        = sock_common_recvmsg,
 511         .mmap           = sock_no_mmap,
 512         .sendpage       = sock_no_sendpage,
 513 };
 514 EXPORT_SYMBOL(phonet_stream_ops);
 515
 516 /* allocate port for a socket */
 517 int pn_sock_get_port(struct sock *sk, unsigned short sport)
 518 {
 519         static int port_cur;
 520         struct net *net = sock_net(sk);
 521         struct pn_sock *pn = pn_sk(sk);
 522         struct sockaddr_pn try_sa;
 523         struct sock *tmpsk;
 524
 525         memset(&try_sa, 0, sizeof(struct sockaddr_pn));
 526         try_sa.spn_family = AF_PHONET;
 527         WARN_ON(!mutex_is_locked(&port_mutex));
 528         if (!sport) {
 529                 /* search free port */
 530                 int port, pmin, pmax;
 531
 532                 phonet_get_local_port_range(&pmin, &pmax);
 533                 for (port = pmin; port <= pmax; port++) {
 534                         port_cur++;
 535                         if (port_cur < pmin || port_cur > pmax)
 536                                 port_cur = pmin;
 537
 538                         pn_sockaddr_set_port(&try_sa, port_cur);
 539                         tmpsk = pn_find_sock_by_sa(net, &try_sa);
 540                         if (tmpsk == NULL) {
 541                                 sport = port_cur;
 542                                 goto found;
 543                         } else
 544                                 sock_put(tmpsk);
 545                 }
 546         } else {
 547                 /* try to find specific port */
 548                 pn_sockaddr_set_port(&try_sa, sport);
 549                 tmpsk = pn_find_sock_by_sa(net, &try_sa);
 550                 if (tmpsk == NULL)
 551                         /* No sock there! We can use that port... */
 552                         goto found;
 553                 else
 554                         sock_put(tmpsk);
 555         }
 556         /* the port must be in use already */
 557         return -EADDRINUSE;
 558
 559 found:
 560         pn->sobject = pn_object(pn_addr(pn->sobject), sport);
 561         return 0;
 562 }
 563 EXPORT_SYMBOL(pn_sock_get_port);
 564
 565 #ifdef CONFIG_PROC_FS
 566 static struct sock *pn_sock_get_idx(struct seq_file *seq, loff_t pos)
 567 {
 568         struct net *net = seq_file_net(seq);
 569         struct hlist_head *hlist = pnsocks.hlist;
 570         struct hlist_node *node;
 571         struct sock *sknode;
 572         unsigned h;
 573
 574         for (h = 0; h < PN_HASHSIZE; h++) {
 575                 sk_for_each(sknode, node, hlist) {
 576                         if (!net_eq(net, sock_net(sknode)))
 577                                 continue;
 578                         if (!pos)
 579                                 return sknode;
 580                         pos--;
 581                 }
 582                 hlist++;
 583         }
 584         return NULL;
 585 }
 586
 587 static struct sock *pn_sock_get_next(struct seq_file *seq, struct sock *sk)
 588 {
 589         struct net *net = seq_file_net(seq);
 590
 591         do
 592                 sk = sk_next(sk);
 593         while (sk && !net_eq(net, sock_net(sk)));
 594
 595         return sk;
 596 }
 597
 598 static void *pn_sock_seq_start(struct seq_file *seq, loff_t *pos)
 599         __acquires(pnsocks.lock)
 600 {
 601         spin_lock_bh(&pnsocks.lock);
 602         return *pos ? pn_sock_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 603 }
 604
 605 static void *pn_sock_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 606 {
 607         struct sock *sk;
 608
 609         if (v == SEQ_START_TOKEN)
 610                 sk = pn_sock_get_idx(seq, 0);
 611         else
 612                 sk = pn_sock_get_next(seq, v);
 613         (*pos)++;
 614         return sk;
 615 }
 616
 617 static void pn_sock_seq_stop(struct seq_file *seq, void *v)
 618         __releases(pnsocks.lock)
 619 {
 620         spin_unlock_bh(&pnsocks.lock);
 621 }
 622
 623 static int pn_sock_seq_show(struct seq_file *seq, void *v)
 624 {
 625         int len;
 626
 627         if (v == SEQ_START_TOKEN)
 628                 seq_printf(seq, "%s%n", "pt  loc  rem rs st tx_queue rx_queue "
 629                         "  uid inode ref pointer drops", &len);
 630         else {
 631                 struct sock *sk = v;
 632                 struct pn_sock *pn = pn_sk(sk);
 633
 634                 seq_printf(seq, "%2d %04X:%04X:%02X %02X %08X:%08X %5d %lu "
 635                         "%d %p %d%n",
 636                         sk->sk_protocol, pn->sobject, 0, pn->resource,
 637                         sk->sk_state,
 638                         sk_wmem_alloc_get(sk), sk_rmem_alloc_get(sk),
 639                         sock_i_uid(sk), sock_i_ino(sk),
 640                         atomic_read(&sk->sk_refcnt), sk,
 641                         atomic_read(&sk->sk_drops), &len);
 642         }
 643         seq_printf(seq, "%*s\n", 127 - len, "");
 644         return 0;
 645 }
 646
 647 static const struct seq_operations pn_sock_seq_ops = {
 648         .start = pn_sock_seq_start,
 649         .next = pn_sock_seq_next,
 650         .stop = pn_sock_seq_stop,
 651         .show = pn_sock_seq_show,
 652 };
 653
 654 static int pn_sock_open(struct inode *inode, struct file *file)
 655 {
 656         return seq_open_net(inode, file, &pn_sock_seq_ops,
 657                                 sizeof(struct seq_net_private));
 658 }
 659
 660 const struct file_operations pn_sock_seq_fops = {
 661         .owner = THIS_MODULE,
 662         .open = pn_sock_open,
 663         .read = seq_read,
 664         .llseek = seq_lseek,
 665         .release = seq_release_net,
 666 };
 667 #endif
 668
 669 static struct  {
 670         struct sock *sk[256];
 671 } pnres;
 672
 673 /*
 674  * Find and hold socket based on resource.
 675  */
 676 struct sock *pn_find_sock_by_res(struct net *net, u8 res)
 677 {
 678         struct sock *sk;
 679
 680         if (!net_eq(net, &init_net))
 681                 return NULL;
 682
 683         rcu_read_lock();
 684         sk = rcu_dereference(pnres.sk[res]);
 685         if (sk)
 686                 sock_hold(sk);
 687         rcu_read_unlock();
 688         return sk;
 689 }
 690
 691 static DEFINE_MUTEX(resource_mutex);
 692
 693 int pn_sock_bind_res(struct sock *sk, u8 res)
 694 {
 695         int ret = -EADDRINUSE;
 696
 697         if (!net_eq(sock_net(sk), &init_net))
 698                 return -ENOIOCTLCMD;
 699         if (!capable(CAP_SYS_ADMIN))
 700                 return -EPERM;
 701         if (pn_socket_autobind(sk->sk_socket))
 702                 return -EAGAIN;
 703
 704         mutex_lock(&resource_mutex);
 705         if (pnres.sk[res] == NULL) {
 706                 sock_hold(sk);
 707                 rcu_assign_pointer(pnres.sk[res], sk);
 708                 ret = 0;
 709         }
 710         mutex_unlock(&resource_mutex);
 711         return ret;
 712 }
 713
 714 int pn_sock_unbind_res(struct sock *sk, u8 res)
 715 {
 716         int ret = -ENOENT;
 717
 718         if (!capable(CAP_SYS_ADMIN))
 719                 return -EPERM;
 720
 721         mutex_lock(&resource_mutex);
 722         if (pnres.sk[res] == sk) {
 723                 rcu_assign_pointer(pnres.sk[res], NULL);
 724                 ret = 0;
 725         }
 726         mutex_unlock(&resource_mutex);
 727
 728         if (ret == 0) {
 729                 synchronize_rcu();
 730                 sock_put(sk);
 731         }
 732         return ret;
 733 }
 734
 735 void pn_sock_unbind_all_res(struct sock *sk)
 736 {
 737         unsigned res, match = 0;
 738
 739         mutex_lock(&resource_mutex);
 740         for (res = 0; res < 256; res++) {
 741                 if (pnres.sk[res] == sk) {
 742                         rcu_assign_pointer(pnres.sk[res], NULL);
 743                         match++;
 744                 }
 745         }
 746         mutex_unlock(&resource_mutex);
 747
 748         if (match == 0)
 749                 return;
 750         synchronize_rcu();
 751         while (match > 0) {
 752                 sock_put(sk);
 753                 match--;
 754         }
 755 }
 756
 757 #ifdef CONFIG_PROC_FS
 758 static struct sock **pn_res_get_idx(struct seq_file *seq, loff_t pos)
 759 {
 760         struct net *net = seq_file_net(seq);
 761         unsigned i;
 762
 763         if (!net_eq(net, &init_net))
 764                 return NULL;
 765
 766         for (i = 0; i < 256; i++) {
 767                 if (pnres.sk[i] == NULL)
 768                         continue;
 769                 if (!pos)
 770                         return pnres.sk + i;
 771                 pos--;
 772         }
 773         return NULL;
 774 }
 775
 776 static struct sock **pn_res_get_next(struct seq_file *seq, struct sock **sk)
 777 {
 778         struct net *net = seq_file_net(seq);
 779         unsigned i;
 780
 781         BUG_ON(!net_eq(net, &init_net));
 782
 783         for (i = (sk - pnres.sk) + 1; i < 256; i++)
 784                 if (pnres.sk[i])
 785                         return pnres.sk + i;
 786         return NULL;
 787 }
 788
 789 static void *pn_res_seq_start(struct seq_file *seq, loff_t *pos)
 790         __acquires(resource_mutex)
 791 {
 792         mutex_lock(&resource_mutex);
 793         return *pos ? pn_res_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 794 }
 795
 796 static void *pn_res_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 797 {
 798         struct sock **sk;
 799
 800         if (v == SEQ_START_TOKEN)
 801                 sk = pn_res_get_idx(seq, 0);
 802         else
 803                 sk = pn_res_get_next(seq, v);
 804         (*pos)++;
 805         return sk;
 806 }
 807
 808 static void pn_res_seq_stop(struct seq_file *seq, void *v)
 809         __releases(resource_mutex)
 810 {
 811         mutex_unlock(&resource_mutex);
 812 }
 813
 814 static int pn_res_seq_show(struct seq_file *seq, void *v)
 815 {
 816         int len;
 817
 818         if (v == SEQ_START_TOKEN)
 819                 seq_printf(seq, "%s%n", "rs   uid inode", &len);
 820         else {
 821                 struct sock **psk = v;
 822                 struct sock *sk = *psk;
 823
 824                 seq_printf(seq, "%02X %5d %lu%n",
 825                            (int) (psk - pnres.sk), sock_i_uid(sk),
 826                            sock_i_ino(sk), &len);
 827         }
 828         seq_printf(seq, "%*s\n", 63 - len, "");
 829         return 0;
 830 }
 831
 832 static const struct seq_operations pn_res_seq_ops = {
 833         .start = pn_res_seq_start,
 834         .next = pn_res_seq_next,
 835         .stop = pn_res_seq_stop,
 836         .show = pn_res_seq_show,
 837 };
 838
 839 static int pn_res_open(struct inode *inode, struct file *file)
 840 {
 841         return seq_open_net(inode, file, &pn_res_seq_ops,
 842                                 sizeof(struct seq_net_private));
 843 }
 844
 845 const struct file_operations pn_res_seq_fops = {
 846         .owner = THIS_MODULE,
 847         .open = pn_res_open,
 848         .read = seq_read,
 849         .llseek = seq_lseek,
 850         .release = seq_release_net,
 851 };
 852 #endif