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