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/kernel.h>
  27#include <linux/net.h>
  28#include <linux/poll.h>
  29#include <net/sock.h>
  30#include <net/tcp_states.h>
  31
  32#include <linux/phonet.h>
  33#include <net/phonet/phonet.h>
  34#include <net/phonet/pep.h>
  35#include <net/phonet/pn_dev.h>
  36
  37static int pn_socket_release(struct socket *sock)
  38{
  39        struct sock *sk = sock->sk;
  40
  41        if (sk) {
  42                sock->sk = NULL;
  43                sk->sk_prot->close(sk, 0);
  44        }
  45        return 0;
  46}
  47
  48static struct  {
  49        struct hlist_head hlist;
  50        spinlock_t lock;
  51} pnsocks = {
  52        .hlist = HLIST_HEAD_INIT,
  53        .lock = __SPIN_LOCK_UNLOCKED(pnsocks.lock),
  54};
  55
  56/*
  57 * Find address based on socket address, match only certain fields.
  58 * Also grab sock if it was found. Remember to sock_put it later.
  59 */
  60struct sock *pn_find_sock_by_sa(const struct sockaddr_pn *spn)
  61{
  62        struct hlist_node *node;
  63        struct sock *sknode;
  64        struct sock *rval = NULL;
  65        u16 obj = pn_sockaddr_get_object(spn);
  66        u8 res = spn->spn_resource;
  67
  68        spin_lock_bh(&pnsocks.lock);
  69
  70        sk_for_each(sknode, node, &pnsocks.hlist) {
  71                struct pn_sock *pn = pn_sk(sknode);
  72                BUG_ON(!pn->sobject); /* unbound socket */
  73
  74                if (pn_port(obj)) {
  75                        /* Look up socket by port */
  76                        if (pn_port(pn->sobject) != pn_port(obj))
  77                                continue;
  78                } else {
  79                        /* If port is zero, look up by resource */
  80                        if (pn->resource != res)
  81                                continue;
  82                }
  83                if (pn_addr(pn->sobject)
  84                 && pn_addr(pn->sobject) != pn_addr(obj))
  85                        continue;
  86
  87                rval = sknode;
  88                sock_hold(sknode);
  89                break;
  90        }
  91
  92        spin_unlock_bh(&pnsocks.lock);
  93
  94        return rval;
  95
  96}
  97
  98void pn_sock_hash(struct sock *sk)
  99{
 100        spin_lock_bh(&pnsocks.lock);
 101        sk_add_node(sk, &pnsocks.hlist);
 102        spin_unlock_bh(&pnsocks.lock);
 103}
 104EXPORT_SYMBOL(pn_sock_hash);
 105
 106void pn_sock_unhash(struct sock *sk)
 107{
 108        spin_lock_bh(&pnsocks.lock);
 109        sk_del_node_init(sk);
 110        spin_unlock_bh(&pnsocks.lock);
 111}
 112EXPORT_SYMBOL(pn_sock_unhash);
 113
 114static int pn_socket_bind(struct socket *sock, struct sockaddr *addr, int len)
 115{
 116        struct sock *sk = sock->sk;
 117        struct pn_sock *pn = pn_sk(sk);
 118        struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
 119        int err;
 120        u16 handle;
 121        u8 saddr;
 122
 123        if (sk->sk_prot->bind)
 124                return sk->sk_prot->bind(sk, addr, len);
 125
 126        if (len < sizeof(struct sockaddr_pn))
 127                return -EINVAL;
 128        if (spn->spn_family != AF_PHONET)
 129                return -EAFNOSUPPORT;
 130
 131        handle = pn_sockaddr_get_object((struct sockaddr_pn *)addr);
 132        saddr = pn_addr(handle);
 133        if (saddr && phonet_address_lookup(saddr))
 134                return -EADDRNOTAVAIL;
 135
 136        lock_sock(sk);
 137        if (sk->sk_state != TCP_CLOSE || pn_port(pn->sobject)) {
 138                err = -EINVAL; /* attempt to rebind */
 139                goto out;
 140        }
 141        err = sk->sk_prot->get_port(sk, pn_port(handle));
 142        if (err)
 143                goto out;
 144
 145        /* get_port() sets the port, bind() sets the address if applicable */
 146        pn->sobject = pn_object(saddr, pn_port(pn->sobject));
 147        pn->resource = spn->spn_resource;
 148
 149        /* Enable RX on the socket */
 150        sk->sk_prot->hash(sk);
 151out:
 152        release_sock(sk);
 153        return err;
 154}
 155
 156static int pn_socket_autobind(struct socket *sock)
 157{
 158        struct sockaddr_pn sa;
 159        int err;
 160
 161        memset(&sa, 0, sizeof(sa));
 162        sa.spn_family = AF_PHONET;
 163        err = pn_socket_bind(sock, (struct sockaddr *)&sa,
 164                                sizeof(struct sockaddr_pn));
 165        if (err != -EINVAL)
 166                return err;
 167        BUG_ON(!pn_port(pn_sk(sock->sk)->sobject));
 168        return 0; /* socket was already bound */
 169}
 170
 171static int pn_socket_accept(struct socket *sock, struct socket *newsock,
 172                                int flags)
 173{
 174        struct sock *sk = sock->sk;
 175        struct sock *newsk;
 176        int err;
 177
 178        newsk = sk->sk_prot->accept(sk, flags, &err);
 179        if (!newsk)
 180                return err;
 181
 182        lock_sock(newsk);
 183        sock_graft(newsk, newsock);
 184        newsock->state = SS_CONNECTED;
 185        release_sock(newsk);
 186        return 0;
 187}
 188
 189static int pn_socket_getname(struct socket *sock, struct sockaddr *addr,
 190                                int *sockaddr_len, int peer)
 191{
 192        struct sock *sk = sock->sk;
 193        struct pn_sock *pn = pn_sk(sk);
 194
 195        memset(addr, 0, sizeof(struct sockaddr_pn));
 196        addr->sa_family = AF_PHONET;
 197        if (!peer) /* Race with bind() here is userland's problem. */
 198                pn_sockaddr_set_object((struct sockaddr_pn *)addr,
 199                                        pn->sobject);
 200
 201        *sockaddr_len = sizeof(struct sockaddr_pn);
 202        return 0;
 203}
 204
 205static unsigned int pn_socket_poll(struct file *file, struct socket *sock,
 206                                        poll_table *wait)
 207{
 208        struct sock *sk = sock->sk;
 209        struct pep_sock *pn = pep_sk(sk);
 210        unsigned int mask = 0;
 211
 212        poll_wait(file, &sock->wait, wait);
 213
 214        switch (sk->sk_state) {
 215        case TCP_LISTEN:
 216                return hlist_empty(&pn->ackq) ? 0 : POLLIN;
 217        case TCP_CLOSE:
 218                return POLLERR;
 219        }
 220
 221        if (!skb_queue_empty(&sk->sk_receive_queue))
 222                mask |= POLLIN | POLLRDNORM;
 223        if (!skb_queue_empty(&pn->ctrlreq_queue))
 224                mask |= POLLPRI;
 225        if (!mask && sk->sk_state == TCP_CLOSE_WAIT)
 226                return POLLHUP;
 227
 228        if (sk->sk_state == TCP_ESTABLISHED && pn->tx_credits)
 229                mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
 230
 231        return mask;
 232}
 233
 234static int pn_socket_ioctl(struct socket *sock, unsigned int cmd,
 235                                unsigned long arg)
 236{
 237        struct sock *sk = sock->sk;
 238        struct pn_sock *pn = pn_sk(sk);
 239
 240        if (cmd == SIOCPNGETOBJECT) {
 241                struct net_device *dev;
 242                u16 handle;
 243                u8 saddr;
 244
 245                if (get_user(handle, (__u16 __user *)arg))
 246                        return -EFAULT;
 247
 248                lock_sock(sk);
 249                if (sk->sk_bound_dev_if)
 250                        dev = dev_get_by_index(sock_net(sk),
 251                                                sk->sk_bound_dev_if);
 252                else
 253                        dev = phonet_device_get(sock_net(sk));
 254                if (dev && (dev->flags & IFF_UP))
 255                        saddr = phonet_address_get(dev, pn_addr(handle));
 256                else
 257                        saddr = PN_NO_ADDR;
 258                release_sock(sk);
 259
 260                if (dev)
 261                        dev_put(dev);
 262                if (saddr == PN_NO_ADDR)
 263                        return -EHOSTUNREACH;
 264
 265                handle = pn_object(saddr, pn_port(pn->sobject));
 266                return put_user(handle, (__u16 __user *)arg);
 267        }
 268
 269        return sk->sk_prot->ioctl(sk, cmd, arg);
 270}
 271
 272static int pn_socket_listen(struct socket *sock, int backlog)
 273{
 274        struct sock *sk = sock->sk;
 275        int err = 0;
 276
 277        if (sock->state != SS_UNCONNECTED)
 278                return -EINVAL;
 279        if (pn_socket_autobind(sock))
 280                return -ENOBUFS;
 281
 282        lock_sock(sk);
 283        if (sk->sk_state != TCP_CLOSE) {
 284                err = -EINVAL;
 285                goto out;
 286        }
 287
 288        sk->sk_state = TCP_LISTEN;
 289        sk->sk_ack_backlog = 0;
 290        sk->sk_max_ack_backlog = backlog;
 291out:
 292        release_sock(sk);
 293        return err;
 294}
 295
 296static int pn_socket_sendmsg(struct kiocb *iocb, struct socket *sock,
 297                                struct msghdr *m, size_t total_len)
 298{
 299        struct sock *sk = sock->sk;
 300
 301        if (pn_socket_autobind(sock))
 302                return -EAGAIN;
 303
 304        return sk->sk_prot->sendmsg(iocb, sk, m, total_len);
 305}
 306
 307const struct proto_ops phonet_dgram_ops = {
 308        .family         = AF_PHONET,
 309        .owner          = THIS_MODULE,
 310        .release        = pn_socket_release,
 311        .bind           = pn_socket_bind,
 312        .connect        = sock_no_connect,
 313        .socketpair     = sock_no_socketpair,
 314        .accept         = sock_no_accept,
 315        .getname        = pn_socket_getname,
 316        .poll           = datagram_poll,
 317        .ioctl          = pn_socket_ioctl,
 318        .listen         = sock_no_listen,
 319        .shutdown       = sock_no_shutdown,
 320        .setsockopt     = sock_no_setsockopt,
 321        .getsockopt     = sock_no_getsockopt,
 322#ifdef CONFIG_COMPAT
 323        .compat_setsockopt = sock_no_setsockopt,
 324        .compat_getsockopt = sock_no_getsockopt,
 325#endif
 326        .sendmsg        = pn_socket_sendmsg,
 327        .recvmsg        = sock_common_recvmsg,
 328        .mmap           = sock_no_mmap,
 329        .sendpage       = sock_no_sendpage,
 330};
 331
 332const struct proto_ops phonet_stream_ops = {
 333        .family         = AF_PHONET,
 334        .owner          = THIS_MODULE,
 335        .release        = pn_socket_release,
 336        .bind           = pn_socket_bind,
 337        .connect        = sock_no_connect,
 338        .socketpair     = sock_no_socketpair,
 339        .accept         = pn_socket_accept,
 340        .getname        = pn_socket_getname,
 341        .poll           = pn_socket_poll,
 342        .ioctl          = pn_socket_ioctl,
 343        .listen         = pn_socket_listen,
 344        .shutdown       = sock_no_shutdown,
 345        .setsockopt     = sock_common_setsockopt,
 346        .getsockopt     = sock_common_getsockopt,
 347#ifdef CONFIG_COMPAT
 348        .compat_setsockopt = compat_sock_common_setsockopt,
 349        .compat_getsockopt = compat_sock_common_getsockopt,
 350#endif
 351        .sendmsg        = pn_socket_sendmsg,
 352        .recvmsg        = sock_common_recvmsg,
 353        .mmap           = sock_no_mmap,
 354        .sendpage       = sock_no_sendpage,
 355};
 356EXPORT_SYMBOL(phonet_stream_ops);
 357
 358static DEFINE_MUTEX(port_mutex);
 359
 360/* allocate port for a socket */
 361int pn_sock_get_port(struct sock *sk, unsigned short sport)
 362{
 363        static int port_cur;
 364        struct pn_sock *pn = pn_sk(sk);
 365        struct sockaddr_pn try_sa;
 366        struct sock *tmpsk;
 367
 368        memset(&try_sa, 0, sizeof(struct sockaddr_pn));
 369        try_sa.spn_family = AF_PHONET;
 370
 371        mutex_lock(&port_mutex);
 372
 373        if (!sport) {
 374                /* search free port */
 375                int port, pmin, pmax;
 376
 377                phonet_get_local_port_range(&pmin, &pmax);
 378                for (port = pmin; port <= pmax; port++) {
 379                        port_cur++;
 380                        if (port_cur < pmin || port_cur > pmax)
 381                                port_cur = pmin;
 382
 383                        pn_sockaddr_set_port(&try_sa, port_cur);
 384                        tmpsk = pn_find_sock_by_sa(&try_sa);
 385                        if (tmpsk == NULL) {
 386                                sport = port_cur;
 387                                goto found;
 388                        } else
 389                                sock_put(tmpsk);
 390                }
 391        } else {
 392                /* try to find specific port */
 393                pn_sockaddr_set_port(&try_sa, sport);
 394                tmpsk = pn_find_sock_by_sa(&try_sa);
 395                if (tmpsk == NULL)
 396                        /* No sock there! We can use that port... */
 397                        goto found;
 398                else
 399                        sock_put(tmpsk);
 400        }
 401        mutex_unlock(&port_mutex);
 402
 403        /* the port must be in use already */
 404        return -EADDRINUSE;
 405
 406found:
 407        mutex_unlock(&port_mutex);
 408        pn->sobject = pn_object(pn_addr(pn->sobject), sport);
 409        return 0;
 410}
 411EXPORT_SYMBOL(pn_sock_get_port);
 412
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