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/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
  37 static 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
  48 static 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  */
  60 struct sock *pn_find_sock_by_sa(struct net *net, 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 (!net_eq(sock_net(sknode), net))
  75                         continue;
  76                 if (pn_port(obj)) {
  77                         /* Look up socket by port */
  78                         if (pn_port(pn->sobject) != pn_port(obj))
  79                                 continue;
  80                 } else {
  81                         /* If port is zero, look up by resource */
  82                         if (pn->resource != res)
  83                                 continue;
  84                 }
  85                 if (pn_addr(pn->sobject)
  86                  && pn_addr(pn->sobject) != pn_addr(obj))
  87                         continue;
  88
  89                 rval = sknode;
  90                 sock_hold(sknode);
  91                 break;
  92         }
  93
  94         spin_unlock_bh(&pnsocks.lock);
  95
  96         return rval;
  97
  98 }
  99
 100 void pn_sock_hash(struct sock *sk)
 101 {
 102         spin_lock_bh(&pnsocks.lock);
 103         sk_add_node(sk, &pnsocks.hlist);
 104         spin_unlock_bh(&pnsocks.lock);
 105 }
 106 EXPORT_SYMBOL(pn_sock_hash);
 107
 108 void pn_sock_unhash(struct sock *sk)
 109 {
 110         spin_lock_bh(&pnsocks.lock);
 111         sk_del_node_init(sk);
 112         spin_unlock_bh(&pnsocks.lock);
 113 }
 114 EXPORT_SYMBOL(pn_sock_unhash);
 115
 116 static int pn_socket_bind(struct socket *sock, struct sockaddr *addr, int len)
 117 {
 118         struct sock *sk = sock->sk;
 119         struct pn_sock *pn = pn_sk(sk);
 120         struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
 121         int err;
 122         u16 handle;
 123         u8 saddr;
 124
 125         if (sk->sk_prot->bind)
 126                 return sk->sk_prot->bind(sk, addr, len);
 127
 128         if (len < sizeof(struct sockaddr_pn))
 129                 return -EINVAL;
 130         if (spn->spn_family != AF_PHONET)
 131                 return -EAFNOSUPPORT;
 132
 133         handle = pn_sockaddr_get_object((struct sockaddr_pn *)addr);
 134         saddr = pn_addr(handle);
 135         if (saddr && phonet_address_lookup(sock_net(sk), saddr))
 136                 return -EADDRNOTAVAIL;
 137
 138         lock_sock(sk);
 139         if (sk->sk_state != TCP_CLOSE || pn_port(pn->sobject)) {
 140                 err = -EINVAL; /* attempt to rebind */
 141                 goto out;
 142         }
 143         err = sk->sk_prot->get_port(sk, pn_port(handle));
 144         if (err)
 145                 goto out;
 146
 147         /* get_port() sets the port, bind() sets the address if applicable */
 148         pn->sobject = pn_object(saddr, pn_port(pn->sobject));
 149         pn->resource = spn->spn_resource;
 150
 151         /* Enable RX on the socket */
 152         sk->sk_prot->hash(sk);
 153 out:
 154         release_sock(sk);
 155         return err;
 156 }
 157
 158 static int pn_socket_autobind(struct socket *sock)
 159 {
 160         struct sockaddr_pn sa;
 161         int err;
 162
 163         memset(&sa, 0, sizeof(sa));
 164         sa.spn_family = AF_PHONET;
 165         err = pn_socket_bind(sock, (struct sockaddr *)&sa,
 166                                 sizeof(struct sockaddr_pn));
 167         if (err != -EINVAL)
 168                 return err;
 169         BUG_ON(!pn_port(pn_sk(sock->sk)->sobject));
 170         return 0; /* socket was already bound */
 171 }
 172
 173 static int pn_socket_accept(struct socket *sock, struct socket *newsock,
 174                                 int flags)
 175 {
 176         struct sock *sk = sock->sk;
 177         struct sock *newsk;
 178         int err;
 179
 180         newsk = sk->sk_prot->accept(sk, flags, &err);
 181         if (!newsk)
 182                 return err;
 183
 184         lock_sock(newsk);
 185         sock_graft(newsk, newsock);
 186         newsock->state = SS_CONNECTED;
 187         release_sock(newsk);
 188         return 0;
 189 }
 190
 191 static int pn_socket_getname(struct socket *sock, struct sockaddr *addr,
 192                                 int *sockaddr_len, int peer)
 193 {
 194         struct sock *sk = sock->sk;
 195         struct pn_sock *pn = pn_sk(sk);
 196
 197         memset(addr, 0, sizeof(struct sockaddr_pn));
 198         addr->sa_family = AF_PHONET;
 199         if (!peer) /* Race with bind() here is userland's problem. */
 200                 pn_sockaddr_set_object((struct sockaddr_pn *)addr,
 201                                         pn->sobject);
 202
 203         *sockaddr_len = sizeof(struct sockaddr_pn);
 204         return 0;
 205 }
 206
 207 static unsigned int pn_socket_poll(struct file *file, struct socket *sock,
 208                                         poll_table *wait)
 209 {
 210         struct sock *sk = sock->sk;
 211         struct pep_sock *pn = pep_sk(sk);
 212         unsigned int mask = 0;
 213
 214         poll_wait(file, &sock->wait, wait);
 215
 216         switch (sk->sk_state) {
 217         case TCP_LISTEN:
 218                 return hlist_empty(&pn->ackq) ? 0 : POLLIN;
 219         case TCP_CLOSE:
 220                 return POLLERR;
 221         }
 222
 223         if (!skb_queue_empty(&sk->sk_receive_queue))
 224                 mask |= POLLIN | POLLRDNORM;
 225         if (!skb_queue_empty(&pn->ctrlreq_queue))
 226                 mask |= POLLPRI;
 227         if (!mask && sk->sk_state == TCP_CLOSE_WAIT)
 228                 return POLLHUP;
 229
 230         if (sk->sk_state == TCP_ESTABLISHED && atomic_read(&pn->tx_credits))
 231                 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
 232
 233         return mask;
 234 }
 235
 236 static int pn_socket_ioctl(struct socket *sock, unsigned int cmd,
 237                                 unsigned long arg)
 238 {
 239         struct sock *sk = sock->sk;
 240         struct pn_sock *pn = pn_sk(sk);
 241
 242         if (cmd == SIOCPNGETOBJECT) {
 243                 struct net_device *dev;
 244                 u16 handle;
 245                 u8 saddr;
 246
 247                 if (get_user(handle, (__u16 __user *)arg))
 248                         return -EFAULT;
 249
 250                 lock_sock(sk);
 251                 if (sk->sk_bound_dev_if)
 252                         dev = dev_get_by_index(sock_net(sk),
 253                                                 sk->sk_bound_dev_if);
 254                 else
 255                         dev = phonet_device_get(sock_net(sk));
 256                 if (dev && (dev->flags & IFF_UP))
 257                         saddr = phonet_address_get(dev, pn_addr(handle));
 258                 else
 259                         saddr = PN_NO_ADDR;
 260                 release_sock(sk);
 261
 262                 if (dev)
 263                         dev_put(dev);
 264                 if (saddr == PN_NO_ADDR)
 265                         return -EHOSTUNREACH;
 266
 267                 handle = pn_object(saddr, pn_port(pn->sobject));
 268                 return put_user(handle, (__u16 __user *)arg);
 269         }
 270
 271         return sk->sk_prot->ioctl(sk, cmd, arg);
 272 }
 273
 274 static int pn_socket_listen(struct socket *sock, int backlog)
 275 {
 276         struct sock *sk = sock->sk;
 277         int err = 0;
 278
 279         if (sock->state != SS_UNCONNECTED)
 280                 return -EINVAL;
 281         if (pn_socket_autobind(sock))
 282                 return -ENOBUFS;
 283
 284         lock_sock(sk);
 285         if (sk->sk_state != TCP_CLOSE) {
 286                 err = -EINVAL;
 287                 goto out;
 288         }
 289
 290         sk->sk_state = TCP_LISTEN;
 291         sk->sk_ack_backlog = 0;
 292         sk->sk_max_ack_backlog = backlog;
 293 out:
 294         release_sock(sk);
 295         return err;
 296 }
 297
 298 static int pn_socket_sendmsg(struct kiocb *iocb, struct socket *sock,
 299                                 struct msghdr *m, size_t total_len)
 300 {
 301         struct sock *sk = sock->sk;
 302
 303         if (pn_socket_autobind(sock))
 304                 return -EAGAIN;
 305
 306         return sk->sk_prot->sendmsg(iocb, sk, m, total_len);
 307 }
 308
 309 const struct proto_ops phonet_dgram_ops = {
 310         .family         = AF_PHONET,
 311         .owner          = THIS_MODULE,
 312         .release        = pn_socket_release,
 313         .bind           = pn_socket_bind,
 314         .connect        = sock_no_connect,
 315         .socketpair     = sock_no_socketpair,
 316         .accept         = sock_no_accept,
 317         .getname        = pn_socket_getname,
 318         .poll           = datagram_poll,
 319         .ioctl          = pn_socket_ioctl,
 320         .listen         = sock_no_listen,
 321         .shutdown       = sock_no_shutdown,
 322         .setsockopt     = sock_no_setsockopt,
 323         .getsockopt     = sock_no_getsockopt,
 324 #ifdef CONFIG_COMPAT
 325         .compat_setsockopt = sock_no_setsockopt,
 326         .compat_getsockopt = sock_no_getsockopt,
 327 #endif
 328         .sendmsg        = pn_socket_sendmsg,
 329         .recvmsg        = sock_common_recvmsg,
 330         .mmap           = sock_no_mmap,
 331         .sendpage       = sock_no_sendpage,
 332 };
 333
 334 const struct proto_ops phonet_stream_ops = {
 335         .family         = AF_PHONET,
 336         .owner          = THIS_MODULE,
 337         .release        = pn_socket_release,
 338         .bind           = pn_socket_bind,
 339         .connect        = sock_no_connect,
 340         .socketpair     = sock_no_socketpair,
 341         .accept         = pn_socket_accept,
 342         .getname        = pn_socket_getname,
 343         .poll           = pn_socket_poll,
 344         .ioctl          = pn_socket_ioctl,
 345         .listen         = pn_socket_listen,
 346         .shutdown       = sock_no_shutdown,
 347         .setsockopt     = sock_common_setsockopt,
 348         .getsockopt     = sock_common_getsockopt,
 349 #ifdef CONFIG_COMPAT
 350         .compat_setsockopt = compat_sock_common_setsockopt,
 351         .compat_getsockopt = compat_sock_common_getsockopt,
 352 #endif
 353         .sendmsg        = pn_socket_sendmsg,
 354         .recvmsg        = sock_common_recvmsg,
 355         .mmap           = sock_no_mmap,
 356         .sendpage       = sock_no_sendpage,
 357 };
 358 EXPORT_SYMBOL(phonet_stream_ops);
 359
 360 static DEFINE_MUTEX(port_mutex);
 361
 362 /* allocate port for a socket */
 363 int pn_sock_get_port(struct sock *sk, unsigned short sport)
 364 {
 365         static int port_cur;
 366         struct net *net = sock_net(sk);
 367         struct pn_sock *pn = pn_sk(sk);
 368         struct sockaddr_pn try_sa;
 369         struct sock *tmpsk;
 370
 371         memset(&try_sa, 0, sizeof(struct sockaddr_pn));
 372         try_sa.spn_family = AF_PHONET;
 373
 374         mutex_lock(&port_mutex);
 375
 376         if (!sport) {
 377                 /* search free port */
 378                 int port, pmin, pmax;
 379
 380                 phonet_get_local_port_range(&pmin, &pmax);
 381                 for (port = pmin; port <= pmax; port++) {
 382                         port_cur++;
 383                         if (port_cur < pmin || port_cur > pmax)
 384                                 port_cur = pmin;
 385
 386                         pn_sockaddr_set_port(&try_sa, port_cur);
 387                         tmpsk = pn_find_sock_by_sa(net, &try_sa);
 388                         if (tmpsk == NULL) {
 389                                 sport = port_cur;
 390                                 goto found;
 391                         } else
 392                                 sock_put(tmpsk);
 393                 }
 394         } else {
 395                 /* try to find specific port */
 396                 pn_sockaddr_set_port(&try_sa, sport);
 397                 tmpsk = pn_find_sock_by_sa(net, &try_sa);
 398                 if (tmpsk == NULL)
 399                         /* No sock there! We can use that port... */
 400                         goto found;
 401                 else
 402                         sock_put(tmpsk);
 403         }
 404         mutex_unlock(&port_mutex);
 405
 406         /* the port must be in use already */
 407         return -EADDRINUSE;
 408
 409 found:
 410         mutex_unlock(&port_mutex);
 411         pn->sobject = pn_object(pn_addr(pn->sobject), sport);
 412         return 0;
 413 }
 414 EXPORT_SYMBOL(pn_sock_get_port);