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 #define PN_HASHSIZE     16
  49 #define PN_HASHMASK     (PN_HASHSIZE-1)
  50
  51
  52 static struct  {
  53         struct hlist_head hlist[PN_HASHSIZE];
  54         spinlock_t lock;
  55 } pnsocks;
  56
  57 void __init pn_sock_init(void)
  58 {
  59         unsigned i;
  60
  61         for (i = 0; i < PN_HASHSIZE; i++)
  62                 INIT_HLIST_HEAD(pnsocks.hlist + i);
  63         spin_lock_init(&pnsocks.lock);
  64 }
  65
  66 static struct hlist_head *pn_hash_list(u16 obj)
  67 {
  68         return pnsocks.hlist + (obj & PN_HASHMASK);
  69 }
  70
  71 /*
  72  * Find address based on socket address, match only certain fields.
  73  * Also grab sock if it was found. Remember to sock_put it later.
  74  */
  75 struct sock *pn_find_sock_by_sa(struct net *net, const struct sockaddr_pn *spn)
  76 {
  77         struct hlist_node *node;
  78         struct sock *sknode;
  79         struct sock *rval = NULL;
  80         u16 obj = pn_sockaddr_get_object(spn);
  81         u8 res = spn->spn_resource;
  82         struct hlist_head *hlist = pn_hash_list(obj);
  83
  84         spin_lock_bh(&pnsocks.lock);
  85
  86         sk_for_each(sknode, node, 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
 110         spin_unlock_bh(&pnsocks.lock);
 111
 112         return rval;
 113 }
 114
 115 /* Deliver a broadcast packet (only in bottom-half) */
 116 void pn_deliver_sock_broadcast(struct net *net, struct sk_buff *skb)
 117 {
 118         struct hlist_head *hlist = pnsocks.hlist;
 119         unsigned h;
 120
 121         spin_lock(&pnsocks.lock);
 122         for (h = 0; h < PN_HASHSIZE; h++) {
 123                 struct hlist_node *node;
 124                 struct sock *sknode;
 125
 126                 sk_for_each(sknode, node, hlist) {
 127                         struct sk_buff *clone;
 128
 129                         if (!net_eq(sock_net(sknode), net))
 130                                 continue;
 131                         if (!sock_flag(sknode, SOCK_BROADCAST))
 132                                 continue;
 133
 134                         clone = skb_clone(skb, GFP_ATOMIC);
 135                         if (clone) {
 136                                 sock_hold(sknode);
 137                                 sk_receive_skb(sknode, clone, 0);
 138                         }
 139                 }
 140                 hlist++;
 141         }
 142         spin_unlock(&pnsocks.lock);
 143 }
 144
 145 void pn_sock_hash(struct sock *sk)
 146 {
 147         struct hlist_head *hlist = pn_hash_list(pn_sk(sk)->sobject);
 148
 149         spin_lock_bh(&pnsocks.lock);
 150         sk_add_node(sk, hlist);
 151         spin_unlock_bh(&pnsocks.lock);
 152 }
 153 EXPORT_SYMBOL(pn_sock_hash);
 154
 155 void pn_sock_unhash(struct sock *sk)
 156 {
 157         spin_lock_bh(&pnsocks.lock);
 158         sk_del_node_init(sk);
 159         spin_unlock_bh(&pnsocks.lock);
 160 }
 161 EXPORT_SYMBOL(pn_sock_unhash);
 162
 163 static DEFINE_MUTEX(port_mutex);
 164
 165 static 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);
 204 out_port:
 205         mutex_unlock(&port_mutex);
 206 out:
 207         release_sock(sk);
 208         return err;
 209 }
 210
 211 static 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
 226 static int pn_socket_accept(struct socket *sock, struct socket *newsock,
 227                                 int flags)
 228 {
 229         struct sock *sk = sock->sk;
 230         struct sock *newsk;
 231         int err;
 232
 233         newsk = sk->sk_prot->accept(sk, flags, &err);
 234         if (!newsk)
 235                 return err;
 236
 237         lock_sock(newsk);
 238         sock_graft(newsk, newsock);
 239         newsock->state = SS_CONNECTED;
 240         release_sock(newsk);
 241         return 0;
 242 }
 243
 244 static int pn_socket_getname(struct socket *sock, struct sockaddr *addr,
 245                                 int *sockaddr_len, int peer)
 246 {
 247         struct sock *sk = sock->sk;
 248         struct pn_sock *pn = pn_sk(sk);
 249
 250         memset(addr, 0, sizeof(struct sockaddr_pn));
 251         addr->sa_family = AF_PHONET;
 252         if (!peer) /* Race with bind() here is userland's problem. */
 253                 pn_sockaddr_set_object((struct sockaddr_pn *)addr,
 254                                         pn->sobject);
 255
 256         *sockaddr_len = sizeof(struct sockaddr_pn);
 257         return 0;
 258 }
 259
 260 static unsigned int pn_socket_poll(struct file *file, struct socket *sock,
 261                                         poll_table *wait)
 262 {
 263         struct sock *sk = sock->sk;
 264         struct pep_sock *pn = pep_sk(sk);
 265         unsigned int mask = 0;
 266
 267         poll_wait(file, &sock->wait, wait);
 268
 269         switch (sk->sk_state) {
 270         case TCP_LISTEN:
 271                 return hlist_empty(&pn->ackq) ? 0 : POLLIN;
 272         case TCP_CLOSE:
 273                 return POLLERR;
 274         }
 275
 276         if (!skb_queue_empty(&sk->sk_receive_queue))
 277                 mask |= POLLIN | POLLRDNORM;
 278         if (!skb_queue_empty(&pn->ctrlreq_queue))
 279                 mask |= POLLPRI;
 280         if (!mask && sk->sk_state == TCP_CLOSE_WAIT)
 281                 return POLLHUP;
 282
 283         if (sk->sk_state == TCP_ESTABLISHED && atomic_read(&pn->tx_credits))
 284                 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
 285
 286         return mask;
 287 }
 288
 289 static int pn_socket_ioctl(struct socket *sock, unsigned int cmd,
 290                                 unsigned long arg)
 291 {
 292         struct sock *sk = sock->sk;
 293         struct pn_sock *pn = pn_sk(sk);
 294
 295         if (cmd == SIOCPNGETOBJECT) {
 296                 struct net_device *dev;
 297                 u16 handle;
 298                 u8 saddr;
 299
 300                 if (get_user(handle, (__u16 __user *)arg))
 301                         return -EFAULT;
 302
 303                 lock_sock(sk);
 304                 if (sk->sk_bound_dev_if)
 305                         dev = dev_get_by_index(sock_net(sk),
 306                                                 sk->sk_bound_dev_if);
 307                 else
 308                         dev = phonet_device_get(sock_net(sk));
 309                 if (dev && (dev->flags & IFF_UP))
 310                         saddr = phonet_address_get(dev, pn_addr(handle));
 311                 else
 312                         saddr = PN_NO_ADDR;
 313                 release_sock(sk);
 314
 315                 if (dev)
 316                         dev_put(dev);
 317                 if (saddr == PN_NO_ADDR)
 318                         return -EHOSTUNREACH;
 319
 320                 handle = pn_object(saddr, pn_port(pn->sobject));
 321                 return put_user(handle, (__u16 __user *)arg);
 322         }
 323
 324         return sk->sk_prot->ioctl(sk, cmd, arg);
 325 }
 326
 327 static int pn_socket_listen(struct socket *sock, int backlog)
 328 {
 329         struct sock *sk = sock->sk;
 330         int err = 0;
 331
 332         if (sock->state != SS_UNCONNECTED)
 333                 return -EINVAL;
 334         if (pn_socket_autobind(sock))
 335                 return -ENOBUFS;
 336
 337         lock_sock(sk);
 338         if (sk->sk_state != TCP_CLOSE) {
 339                 err = -EINVAL;
 340                 goto out;
 341         }
 342
 343         sk->sk_state = TCP_LISTEN;
 344         sk->sk_ack_backlog = 0;
 345         sk->sk_max_ack_backlog = backlog;
 346 out:
 347         release_sock(sk);
 348         return err;
 349 }
 350
 351 static int pn_socket_sendmsg(struct kiocb *iocb, struct socket *sock,
 352                                 struct msghdr *m, size_t total_len)
 353 {
 354         struct sock *sk = sock->sk;
 355
 356         if (pn_socket_autobind(sock))
 357                 return -EAGAIN;
 358
 359         return sk->sk_prot->sendmsg(iocb, sk, m, total_len);
 360 }
 361
 362 const struct proto_ops phonet_dgram_ops = {
 363         .family         = AF_PHONET,
 364         .owner          = THIS_MODULE,
 365         .release        = pn_socket_release,
 366         .bind           = pn_socket_bind,
 367         .connect        = sock_no_connect,
 368         .socketpair     = sock_no_socketpair,
 369         .accept         = sock_no_accept,
 370         .getname        = pn_socket_getname,
 371         .poll           = datagram_poll,
 372         .ioctl          = pn_socket_ioctl,
 373         .listen         = sock_no_listen,
 374         .shutdown       = sock_no_shutdown,
 375         .setsockopt     = sock_no_setsockopt,
 376         .getsockopt     = sock_no_getsockopt,
 377 #ifdef CONFIG_COMPAT
 378         .compat_setsockopt = sock_no_setsockopt,
 379         .compat_getsockopt = sock_no_getsockopt,
 380 #endif
 381         .sendmsg        = pn_socket_sendmsg,
 382         .recvmsg        = sock_common_recvmsg,
 383         .mmap           = sock_no_mmap,
 384         .sendpage       = sock_no_sendpage,
 385 };
 386
 387 const struct proto_ops phonet_stream_ops = {
 388         .family         = AF_PHONET,
 389         .owner          = THIS_MODULE,
 390         .release        = pn_socket_release,
 391         .bind           = pn_socket_bind,
 392         .connect        = sock_no_connect,
 393         .socketpair     = sock_no_socketpair,
 394         .accept         = pn_socket_accept,
 395         .getname        = pn_socket_getname,
 396         .poll           = pn_socket_poll,
 397         .ioctl          = pn_socket_ioctl,
 398         .listen         = pn_socket_listen,
 399         .shutdown       = sock_no_shutdown,
 400         .setsockopt     = sock_common_setsockopt,
 401         .getsockopt     = sock_common_getsockopt,
 402 #ifdef CONFIG_COMPAT
 403         .compat_setsockopt = compat_sock_common_setsockopt,
 404         .compat_getsockopt = compat_sock_common_getsockopt,
 405 #endif
 406         .sendmsg        = pn_socket_sendmsg,
 407         .recvmsg        = sock_common_recvmsg,
 408         .mmap           = sock_no_mmap,
 409         .sendpage       = sock_no_sendpage,
 410 };
 411 EXPORT_SYMBOL(phonet_stream_ops);
 412
 413 /* allocate port for a socket */
 414 int pn_sock_get_port(struct sock *sk, unsigned short sport)
 415 {
 416         static int port_cur;
 417         struct net *net = sock_net(sk);
 418         struct pn_sock *pn = pn_sk(sk);
 419         struct sockaddr_pn try_sa;
 420         struct sock *tmpsk;
 421
 422         memset(&try_sa, 0, sizeof(struct sockaddr_pn));
 423         try_sa.spn_family = AF_PHONET;
 424         WARN_ON(!mutex_is_locked(&port_mutex));
 425         if (!sport) {
 426                 /* search free port */
 427                 int port, pmin, pmax;
 428
 429                 phonet_get_local_port_range(&pmin, &pmax);
 430                 for (port = pmin; port <= pmax; port++) {
 431                         port_cur++;
 432                         if (port_cur < pmin || port_cur > pmax)
 433                                 port_cur = pmin;
 434
 435                         pn_sockaddr_set_port(&try_sa, port_cur);
 436                         tmpsk = pn_find_sock_by_sa(net, &try_sa);
 437                         if (tmpsk == NULL) {
 438                                 sport = port_cur;
 439                                 goto found;
 440                         } else
 441                                 sock_put(tmpsk);
 442                 }
 443         } else {
 444                 /* try to find specific port */
 445                 pn_sockaddr_set_port(&try_sa, sport);
 446                 tmpsk = pn_find_sock_by_sa(net, &try_sa);
 447                 if (tmpsk == NULL)
 448                         /* No sock there! We can use that port... */
 449                         goto found;
 450                 else
 451                         sock_put(tmpsk);
 452         }
 453         /* the port must be in use already */
 454         return -EADDRINUSE;
 455
 456 found:
 457         pn->sobject = pn_object(pn_addr(pn->sobject), sport);
 458         return 0;
 459 }
 460 EXPORT_SYMBOL(pn_sock_get_port);
 461
 462 #ifdef CONFIG_PROC_FS
 463 static struct sock *pn_sock_get_idx(struct seq_file *seq, loff_t pos)
 464 {
 465         struct net *net = seq_file_net(seq);
 466         struct hlist_head *hlist = pnsocks.hlist;
 467         struct hlist_node *node;
 468         struct sock *sknode;
 469         unsigned h;
 470
 471         for (h = 0; h < PN_HASHSIZE; h++) {
 472                 sk_for_each(sknode, node, hlist) {
 473                         if (!net_eq(net, sock_net(sknode)))
 474                                 continue;
 475                         if (!pos)
 476                                 return sknode;
 477                         pos--;
 478                 }
 479                 hlist++;
 480         }
 481         return NULL;
 482 }
 483
 484 static struct sock *pn_sock_get_next(struct seq_file *seq, struct sock *sk)
 485 {
 486         struct net *net = seq_file_net(seq);
 487
 488         do
 489                 sk = sk_next(sk);
 490         while (sk && !net_eq(net, sock_net(sk)));
 491
 492         return sk;
 493 }
 494
 495 static void *pn_sock_seq_start(struct seq_file *seq, loff_t *pos)
 496         __acquires(pnsocks.lock)
 497 {
 498         spin_lock_bh(&pnsocks.lock);
 499         return *pos ? pn_sock_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 500 }
 501
 502 static void *pn_sock_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 503 {
 504         struct sock *sk;
 505
 506         if (v == SEQ_START_TOKEN)
 507                 sk = pn_sock_get_idx(seq, 0);
 508         else
 509                 sk = pn_sock_get_next(seq, v);
 510         (*pos)++;
 511         return sk;
 512 }
 513
 514 static void pn_sock_seq_stop(struct seq_file *seq, void *v)
 515         __releases(pnsocks.lock)
 516 {
 517         spin_unlock_bh(&pnsocks.lock);
 518 }
 519
 520 static int pn_sock_seq_show(struct seq_file *seq, void *v)
 521 {
 522         int len;
 523
 524         if (v == SEQ_START_TOKEN)
 525                 seq_printf(seq, "%s%n", "pt  loc  rem rs st tx_queue rx_queue "
 526                         "  uid inode ref pointer drops", &len);
 527         else {
 528                 struct sock *sk = v;
 529                 struct pn_sock *pn = pn_sk(sk);
 530
 531                 seq_printf(seq, "%2d %04X:%04X:%02X %02X %08X:%08X %5d %lu "
 532                         "%d %p %d%n",
 533                         sk->sk_protocol, pn->sobject, 0, pn->resource,
 534                         sk->sk_state,
 535                         sk_wmem_alloc_get(sk), sk_rmem_alloc_get(sk),
 536                         sock_i_uid(sk), sock_i_ino(sk),
 537                         atomic_read(&sk->sk_refcnt), sk,
 538                         atomic_read(&sk->sk_drops), &len);
 539         }
 540         seq_printf(seq, "%*s\n", 127 - len, "");
 541         return 0;
 542 }
 543
 544 static const struct seq_operations pn_sock_seq_ops = {
 545         .start = pn_sock_seq_start,
 546         .next = pn_sock_seq_next,
 547         .stop = pn_sock_seq_stop,
 548         .show = pn_sock_seq_show,
 549 };
 550
 551 static int pn_sock_open(struct inode *inode, struct file *file)
 552 {
 553         return seq_open_net(inode, file, &pn_sock_seq_ops,
 554                                 sizeof(struct seq_net_private));
 555 }
 556
 557 const struct file_operations pn_sock_seq_fops = {
 558         .owner = THIS_MODULE,
 559         .open = pn_sock_open,
 560         .read = seq_read,
 561         .llseek = seq_lseek,
 562         .release = seq_release_net,
 563 };
 564 #endif