linux/net/phonet/socket.c
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   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
  38static 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
  53static struct  {
  54        struct hlist_head hlist[PN_HASHSIZE];
  55        struct mutex lock;
  56} pnsocks;
  57
  58void __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
  67static 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 */
  76struct 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) */
 115void 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
 144void 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}
 152EXPORT_SYMBOL(pn_sock_hash);
 153
 154void 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}
 162EXPORT_SYMBOL(pn_sock_unhash);
 163
 164static DEFINE_MUTEX(port_mutex);
 165
 166static 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);
 205out_port:
 206        mutex_unlock(&port_mutex);
 207out:
 208        release_sock(sk);
 209        return err;
 210}
 211
 212static 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
 227static 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;
 299out:
 300        release_sock(sk);
 301        return err;
 302}
 303
 304static 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
 325static 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
 341static 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
 367static 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
 405static 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;
 424out:
 425        release_sock(sk);
 426        return err;
 427}
 428
 429static 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
 440const 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
 465const 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};
 489EXPORT_SYMBOL(phonet_stream_ops);
 490
 491/* allocate port for a socket */
 492int 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
 534found:
 535        pn->sobject = pn_object(pn_addr(pn->sobject), sport);
 536        return 0;
 537}
 538EXPORT_SYMBOL(pn_sock_get_port);
 539
 540#ifdef CONFIG_PROC_FS
 541static 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
 562static 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
 573static 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
 580static 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
 592static void pn_sock_seq_stop(struct seq_file *seq, void *v)
 593        __releases(rcu)
 594{
 595        rcu_read_unlock();
 596}
 597
 598static 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
 622static 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
 629static 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
 635const 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
 644static struct  {
 645        struct sock *sk[256];
 646} pnres;
 647
 648/*
 649 * Find and hold socket based on resource.
 650 */
 651struct 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
 666static DEFINE_MUTEX(resource_mutex);
 667
 668int 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
 689int 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
 710void 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
 731static 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
 749static 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
 762static 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
 769static 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
 781static void pn_res_seq_stop(struct seq_file *seq, void *v)
 782        __releases(resource_mutex)
 783{
 784        mutex_unlock(&resource_mutex);
 785}
 786
 787static 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
 805static 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
 812static 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
 818const 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
 826