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