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(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
  98 void 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 }
 104 EXPORT_SYMBOL(pn_sock_hash);
 105
 106 void 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 }
 112 EXPORT_SYMBOL(pn_sock_unhash);
 113
 114 static 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);
 151 out:
 152         release_sock(sk);
 153         return err;
 154 }
 155
 156 static 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
 171 static 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
 189 static 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
 205 static 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
 234 static 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
 272 static 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;
 291 out:
 292         release_sock(sk);
 293         return err;
 294 }
 295
 296 static 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
 307 const 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
 332 const 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 };
 356 EXPORT_SYMBOL(phonet_stream_ops);
 357
 358 static DEFINE_MUTEX(port_mutex);
 359
 360 /* allocate port for a socket */
 361 int 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
 406 found:
 407         mutex_unlock(&port_mutex);
 408         pn->sobject = pn_object(pn_addr(pn->sobject), sport);
 409         return 0;
 410 }
 411 EXPORT_SYMBOL(pn_sock_get_port);