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 DEFINE_MUTEX(port_mutex);
 117
 118 static int pn_socket_bind(struct socket *sock, struct sockaddr *addr, int len)
 119 {
 120         struct sock *sk = sock->sk;
 121         struct pn_sock *pn = pn_sk(sk);
 122         struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
 123         int err;
 124         u16 handle;
 125         u8 saddr;
 126
 127         if (sk->sk_prot->bind)
 128                 return sk->sk_prot->bind(sk, addr, len);
 129
 130         if (len < sizeof(struct sockaddr_pn))
 131                 return -EINVAL;
 132         if (spn->spn_family != AF_PHONET)
 133                 return -EAFNOSUPPORT;
 134
 135         handle = pn_sockaddr_get_object((struct sockaddr_pn *)addr);
 136         saddr = pn_addr(handle);
 137         if (saddr && phonet_address_lookup(sock_net(sk), saddr))
 138                 return -EADDRNOTAVAIL;
 139
 140         lock_sock(sk);
 141         if (sk->sk_state != TCP_CLOSE || pn_port(pn->sobject)) {
 142                 err = -EINVAL; /* attempt to rebind */
 143                 goto out;
 144         }
 145         WARN_ON(sk_hashed(sk));
 146         mutex_lock(&port_mutex);
 147         err = sk->sk_prot->get_port(sk, pn_port(handle));
 148         if (err)
 149                 goto out_port;
 150
 151         /* get_port() sets the port, bind() sets the address if applicable */
 152         pn->sobject = pn_object(saddr, pn_port(pn->sobject));
 153         pn->resource = spn->spn_resource;
 154
 155         /* Enable RX on the socket */
 156         sk->sk_prot->hash(sk);
 157 out_port:
 158         mutex_unlock(&port_mutex);
 159 out:
 160         release_sock(sk);
 161         return err;
 162 }
 163
 164 static int pn_socket_autobind(struct socket *sock)
 165 {
 166         struct sockaddr_pn sa;
 167         int err;
 168
 169         memset(&sa, 0, sizeof(sa));
 170         sa.spn_family = AF_PHONET;
 171         err = pn_socket_bind(sock, (struct sockaddr *)&sa,
 172                                 sizeof(struct sockaddr_pn));
 173         if (err != -EINVAL)
 174                 return err;
 175         BUG_ON(!pn_port(pn_sk(sock->sk)->sobject));
 176         return 0; /* socket was already bound */
 177 }
 178
 179 static int pn_socket_accept(struct socket *sock, struct socket *newsock,
 180                                 int flags)
 181 {
 182         struct sock *sk = sock->sk;
 183         struct sock *newsk;
 184         int err;
 185
 186         newsk = sk->sk_prot->accept(sk, flags, &err);
 187         if (!newsk)
 188                 return err;
 189
 190         lock_sock(newsk);
 191         sock_graft(newsk, newsock);
 192         newsock->state = SS_CONNECTED;
 193         release_sock(newsk);
 194         return 0;
 195 }
 196
 197 static int pn_socket_getname(struct socket *sock, struct sockaddr *addr,
 198                                 int *sockaddr_len, int peer)
 199 {
 200         struct sock *sk = sock->sk;
 201         struct pn_sock *pn = pn_sk(sk);
 202
 203         memset(addr, 0, sizeof(struct sockaddr_pn));
 204         addr->sa_family = AF_PHONET;
 205         if (!peer) /* Race with bind() here is userland's problem. */
 206                 pn_sockaddr_set_object((struct sockaddr_pn *)addr,
 207                                         pn->sobject);
 208
 209         *sockaddr_len = sizeof(struct sockaddr_pn);
 210         return 0;
 211 }
 212
 213 static unsigned int pn_socket_poll(struct file *file, struct socket *sock,
 214                                         poll_table *wait)
 215 {
 216         struct sock *sk = sock->sk;
 217         struct pep_sock *pn = pep_sk(sk);
 218         unsigned int mask = 0;
 219
 220         poll_wait(file, &sock->wait, wait);
 221
 222         switch (sk->sk_state) {
 223         case TCP_LISTEN:
 224                 return hlist_empty(&pn->ackq) ? 0 : POLLIN;
 225         case TCP_CLOSE:
 226                 return POLLERR;
 227         }
 228
 229         if (!skb_queue_empty(&sk->sk_receive_queue))
 230                 mask |= POLLIN | POLLRDNORM;
 231         if (!skb_queue_empty(&pn->ctrlreq_queue))
 232                 mask |= POLLPRI;
 233         if (!mask && sk->sk_state == TCP_CLOSE_WAIT)
 234                 return POLLHUP;
 235
 236         if (sk->sk_state == TCP_ESTABLISHED && atomic_read(&pn->tx_credits))
 237                 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
 238
 239         return mask;
 240 }
 241
 242 static int pn_socket_ioctl(struct socket *sock, unsigned int cmd,
 243                                 unsigned long arg)
 244 {
 245         struct sock *sk = sock->sk;
 246         struct pn_sock *pn = pn_sk(sk);
 247
 248         if (cmd == SIOCPNGETOBJECT) {
 249                 struct net_device *dev;
 250                 u16 handle;
 251                 u8 saddr;
 252
 253                 if (get_user(handle, (__u16 __user *)arg))
 254                         return -EFAULT;
 255
 256                 lock_sock(sk);
 257                 if (sk->sk_bound_dev_if)
 258                         dev = dev_get_by_index(sock_net(sk),
 259                                                 sk->sk_bound_dev_if);
 260                 else
 261                         dev = phonet_device_get(sock_net(sk));
 262                 if (dev && (dev->flags & IFF_UP))
 263                         saddr = phonet_address_get(dev, pn_addr(handle));
 264                 else
 265                         saddr = PN_NO_ADDR;
 266                 release_sock(sk);
 267
 268                 if (dev)
 269                         dev_put(dev);
 270                 if (saddr == PN_NO_ADDR)
 271                         return -EHOSTUNREACH;
 272
 273                 handle = pn_object(saddr, pn_port(pn->sobject));
 274                 return put_user(handle, (__u16 __user *)arg);
 275         }
 276
 277         return sk->sk_prot->ioctl(sk, cmd, arg);
 278 }
 279
 280 static int pn_socket_listen(struct socket *sock, int backlog)
 281 {
 282         struct sock *sk = sock->sk;
 283         int err = 0;
 284
 285         if (sock->state != SS_UNCONNECTED)
 286                 return -EINVAL;
 287         if (pn_socket_autobind(sock))
 288                 return -ENOBUFS;
 289
 290         lock_sock(sk);
 291         if (sk->sk_state != TCP_CLOSE) {
 292                 err = -EINVAL;
 293                 goto out;
 294         }
 295
 296         sk->sk_state = TCP_LISTEN;
 297         sk->sk_ack_backlog = 0;
 298         sk->sk_max_ack_backlog = backlog;
 299 out:
 300         release_sock(sk);
 301         return err;
 302 }
 303
 304 static int pn_socket_sendmsg(struct kiocb *iocb, struct socket *sock,
 305                                 struct msghdr *m, size_t total_len)
 306 {
 307         struct sock *sk = sock->sk;
 308
 309         if (pn_socket_autobind(sock))
 310                 return -EAGAIN;
 311
 312         return sk->sk_prot->sendmsg(iocb, sk, m, total_len);
 313 }
 314
 315 const struct proto_ops phonet_dgram_ops = {
 316         .family         = AF_PHONET,
 317         .owner          = THIS_MODULE,
 318         .release        = pn_socket_release,
 319         .bind           = pn_socket_bind,
 320         .connect        = sock_no_connect,
 321         .socketpair     = sock_no_socketpair,
 322         .accept         = sock_no_accept,
 323         .getname        = pn_socket_getname,
 324         .poll           = datagram_poll,
 325         .ioctl          = pn_socket_ioctl,
 326         .listen         = sock_no_listen,
 327         .shutdown       = sock_no_shutdown,
 328         .setsockopt     = sock_no_setsockopt,
 329         .getsockopt     = sock_no_getsockopt,
 330 #ifdef CONFIG_COMPAT
 331         .compat_setsockopt = sock_no_setsockopt,
 332         .compat_getsockopt = sock_no_getsockopt,
 333 #endif
 334         .sendmsg        = pn_socket_sendmsg,
 335         .recvmsg        = sock_common_recvmsg,
 336         .mmap           = sock_no_mmap,
 337         .sendpage       = sock_no_sendpage,
 338 };
 339
 340 const struct proto_ops phonet_stream_ops = {
 341         .family         = AF_PHONET,
 342         .owner          = THIS_MODULE,
 343         .release        = pn_socket_release,
 344         .bind           = pn_socket_bind,
 345         .connect        = sock_no_connect,
 346         .socketpair     = sock_no_socketpair,
 347         .accept         = pn_socket_accept,
 348         .getname        = pn_socket_getname,
 349         .poll           = pn_socket_poll,
 350         .ioctl          = pn_socket_ioctl,
 351         .listen         = pn_socket_listen,
 352         .shutdown       = sock_no_shutdown,
 353         .setsockopt     = sock_common_setsockopt,
 354         .getsockopt     = sock_common_getsockopt,
 355 #ifdef CONFIG_COMPAT
 356         .compat_setsockopt = compat_sock_common_setsockopt,
 357         .compat_getsockopt = compat_sock_common_getsockopt,
 358 #endif
 359         .sendmsg        = pn_socket_sendmsg,
 360         .recvmsg        = sock_common_recvmsg,
 361         .mmap           = sock_no_mmap,
 362         .sendpage       = sock_no_sendpage,
 363 };
 364 EXPORT_SYMBOL(phonet_stream_ops);
 365
 366 /* allocate port for a socket */
 367 int pn_sock_get_port(struct sock *sk, unsigned short sport)
 368 {
 369         static int port_cur;
 370         struct net *net = sock_net(sk);
 371         struct pn_sock *pn = pn_sk(sk);
 372         struct sockaddr_pn try_sa;
 373         struct sock *tmpsk;
 374
 375         memset(&try_sa, 0, sizeof(struct sockaddr_pn));
 376         try_sa.spn_family = AF_PHONET;
 377         WARN_ON(!mutex_is_locked(&port_mutex));
 378         if (!sport) {
 379                 /* search free port */
 380                 int port, pmin, pmax;
 381
 382                 phonet_get_local_port_range(&pmin, &pmax);
 383                 for (port = pmin; port <= pmax; port++) {
 384                         port_cur++;
 385                         if (port_cur < pmin || port_cur > pmax)
 386                                 port_cur = pmin;
 387
 388                         pn_sockaddr_set_port(&try_sa, port_cur);
 389                         tmpsk = pn_find_sock_by_sa(net, &try_sa);
 390                         if (tmpsk == NULL) {
 391                                 sport = port_cur;
 392                                 goto found;
 393                         } else
 394                                 sock_put(tmpsk);
 395                 }
 396         } else {
 397                 /* try to find specific port */
 398                 pn_sockaddr_set_port(&try_sa, sport);
 399                 tmpsk = pn_find_sock_by_sa(net, &try_sa);
 400                 if (tmpsk == NULL)
 401                         /* No sock there! We can use that port... */
 402                         goto found;
 403                 else
 404                         sock_put(tmpsk);
 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);
 415
 416 #ifdef CONFIG_PROC_FS
 417 static struct sock *pn_sock_get_idx(struct seq_file *seq, loff_t pos)
 418 {
 419         struct net *net = seq_file_net(seq);
 420         struct hlist_node *node;
 421         struct sock *sknode;
 422
 423         sk_for_each(sknode, node, &pnsocks.hlist) {
 424                 if (!net_eq(net, sock_net(sknode)))
 425                         continue;
 426                 if (!pos)
 427                         return sknode;
 428                 pos--;
 429         }
 430         return NULL;
 431 }
 432
 433 static struct sock *pn_sock_get_next(struct seq_file *seq, struct sock *sk)
 434 {
 435         struct net *net = seq_file_net(seq);
 436
 437         do
 438                 sk = sk_next(sk);
 439         while (sk && !net_eq(net, sock_net(sk)));
 440
 441         return sk;
 442 }
 443
 444 static void *pn_sock_seq_start(struct seq_file *seq, loff_t *pos)
 445         __acquires(pnsocks.lock)
 446 {
 447         spin_lock_bh(&pnsocks.lock);
 448         return *pos ? pn_sock_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 449 }
 450
 451 static void *pn_sock_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 452 {
 453         struct sock *sk;
 454
 455         if (v == SEQ_START_TOKEN)
 456                 sk = pn_sock_get_idx(seq, 0);
 457         else
 458                 sk = pn_sock_get_next(seq, v);
 459         (*pos)++;
 460         return sk;
 461 }
 462
 463 static void pn_sock_seq_stop(struct seq_file *seq, void *v)
 464         __releases(pnsocks.lock)
 465 {
 466         spin_unlock_bh(&pnsocks.lock);
 467 }
 468
 469 static int pn_sock_seq_show(struct seq_file *seq, void *v)
 470 {
 471         int len;
 472
 473         if (v == SEQ_START_TOKEN)
 474                 seq_printf(seq, "%s%n", "pt  loc  rem rs st tx_queue rx_queue "
 475                         "  uid inode ref pointer drops", &len);
 476         else {
 477                 struct sock *sk = v;
 478                 struct pn_sock *pn = pn_sk(sk);
 479
 480                 seq_printf(seq, "%2d %04X:%04X:%02X %02X %08X:%08X %5d %lu "
 481                         "%d %p %d%n",
 482                         sk->sk_protocol, pn->sobject, 0, pn->resource,
 483                         sk->sk_state,
 484                         sk_wmem_alloc_get(sk), sk_rmem_alloc_get(sk),
 485                         sock_i_uid(sk), sock_i_ino(sk),
 486                         atomic_read(&sk->sk_refcnt), sk,
 487                         atomic_read(&sk->sk_drops), &len);
 488         }
 489         seq_printf(seq, "%*s\n", 127 - len, "");
 490         return 0;
 491 }
 492
 493 static const struct seq_operations pn_sock_seq_ops = {
 494         .start = pn_sock_seq_start,
 495         .next = pn_sock_seq_next,
 496         .stop = pn_sock_seq_stop,
 497         .show = pn_sock_seq_show,
 498 };
 499
 500 static int pn_sock_open(struct inode *inode, struct file *file)
 501 {
 502         return seq_open_net(inode, file, &pn_sock_seq_ops,
 503                                 sizeof(struct seq_net_private));
 504 }
 505
 506 const struct file_operations pn_sock_seq_fops = {
 507         .owner = THIS_MODULE,
 508         .open = pn_sock_open,
 509         .read = seq_read,
 510         .llseek = seq_lseek,
 511         .release = seq_release_net,
 512 };
 513 #endif