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/gfp.h>
  27 #include <linux/kernel.h>
  28 #include <linux/net.h>
  29 #include <linux/poll.h>
  30 #include <net/sock.h>
  31 #include <net/tcp_states.h>
  32
  33 #include <linux/phonet.h>
  34 #include <net/phonet/phonet.h>
  35 #include <net/phonet/pep.h>
  36 #include <net/phonet/pn_dev.h>
  37
  38 static int pn_socket_release(struct socket *sock)
  39 {
  40         struct sock *sk = sock->sk;
  41
  42         if (sk) {
  43                 sock->sk = NULL;
  44                 sk->sk_prot->close(sk, 0);
  45         }
  46         return 0;
  47 }
  48
  49 #define PN_HASHSIZE     16
  50 #define PN_HASHMASK     (PN_HASHSIZE-1)
  51
  52
  53 static struct  {
  54         struct hlist_head hlist[PN_HASHSIZE];
  55         spinlock_t lock;
  56 } pnsocks;
  57
  58 void __init pn_sock_init(void)
  59 {
  60         unsigned i;
  61
  62         for (i = 0; i < PN_HASHSIZE; i++)
  63                 INIT_HLIST_HEAD(pnsocks.hlist + i);
  64         spin_lock_init(&pnsocks.lock);
  65 }
  66
  67 static struct hlist_head *pn_hash_list(u16 obj)
  68 {
  69         return pnsocks.hlist + (obj & PN_HASHMASK);
  70 }
  71
  72 /*
  73  * Find address based on socket address, match only certain fields.
  74  * Also grab sock if it was found. Remember to sock_put it later.
  75  */
  76 struct sock *pn_find_sock_by_sa(struct net *net, const struct sockaddr_pn *spn)
  77 {
  78         struct hlist_node *node;
  79         struct sock *sknode;
  80         struct sock *rval = NULL;
  81         u16 obj = pn_sockaddr_get_object(spn);
  82         u8 res = spn->spn_resource;
  83         struct hlist_head *hlist = pn_hash_list(obj);
  84
  85         spin_lock_bh(&pnsocks.lock);
  86
  87         sk_for_each(sknode, node, hlist) {
  88                 struct pn_sock *pn = pn_sk(sknode);
  89                 BUG_ON(!pn->sobject); /* unbound socket */
  90
  91                 if (!net_eq(sock_net(sknode), net))
  92                         continue;
  93                 if (pn_port(obj)) {
  94                         /* Look up socket by port */
  95                         if (pn_port(pn->sobject) != pn_port(obj))
  96                                 continue;
  97                 } else {
  98                         /* If port is zero, look up by resource */
  99                         if (pn->resource != res)
 100                                 continue;
 101                 }
 102                 if (pn_addr(pn->sobject) &&
 103                     pn_addr(pn->sobject) != pn_addr(obj))
 104                         continue;
 105
 106                 rval = sknode;
 107                 sock_hold(sknode);
 108                 break;
 109         }
 110
 111         spin_unlock_bh(&pnsocks.lock);
 112
 113         return rval;
 114 }
 115
 116 /* Deliver a broadcast packet (only in bottom-half) */
 117 void pn_deliver_sock_broadcast(struct net *net, struct sk_buff *skb)
 118 {
 119         struct hlist_head *hlist = pnsocks.hlist;
 120         unsigned h;
 121
 122         spin_lock(&pnsocks.lock);
 123         for (h = 0; h < PN_HASHSIZE; h++) {
 124                 struct hlist_node *node;
 125                 struct sock *sknode;
 126
 127                 sk_for_each(sknode, node, hlist) {
 128                         struct sk_buff *clone;
 129
 130                         if (!net_eq(sock_net(sknode), net))
 131                                 continue;
 132                         if (!sock_flag(sknode, SOCK_BROADCAST))
 133                                 continue;
 134
 135                         clone = skb_clone(skb, GFP_ATOMIC);
 136                         if (clone) {
 137                                 sock_hold(sknode);
 138                                 sk_receive_skb(sknode, clone, 0);
 139                         }
 140                 }
 141                 hlist++;
 142         }
 143         spin_unlock(&pnsocks.lock);
 144 }
 145
 146 void pn_sock_hash(struct sock *sk)
 147 {
 148         struct hlist_head *hlist = pn_hash_list(pn_sk(sk)->sobject);
 149
 150         spin_lock_bh(&pnsocks.lock);
 151         sk_add_node(sk, hlist);
 152         spin_unlock_bh(&pnsocks.lock);
 153 }
 154 EXPORT_SYMBOL(pn_sock_hash);
 155
 156 void pn_sock_unhash(struct sock *sk)
 157 {
 158         spin_lock_bh(&pnsocks.lock);
 159         sk_del_node_init(sk);
 160         spin_unlock_bh(&pnsocks.lock);
 161 }
 162 EXPORT_SYMBOL(pn_sock_unhash);
 163
 164 static DEFINE_MUTEX(port_mutex);
 165
 166 static int pn_socket_bind(struct socket *sock, struct sockaddr *addr, int len)
 167 {
 168         struct sock *sk = sock->sk;
 169         struct pn_sock *pn = pn_sk(sk);
 170         struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
 171         int err;
 172         u16 handle;
 173         u8 saddr;
 174
 175         if (sk->sk_prot->bind)
 176                 return sk->sk_prot->bind(sk, addr, len);
 177
 178         if (len < sizeof(struct sockaddr_pn))
 179                 return -EINVAL;
 180         if (spn->spn_family != AF_PHONET)
 181                 return -EAFNOSUPPORT;
 182
 183         handle = pn_sockaddr_get_object((struct sockaddr_pn *)addr);
 184         saddr = pn_addr(handle);
 185         if (saddr && phonet_address_lookup(sock_net(sk), saddr))
 186                 return -EADDRNOTAVAIL;
 187
 188         lock_sock(sk);
 189         if (sk->sk_state != TCP_CLOSE || pn_port(pn->sobject)) {
 190                 err = -EINVAL; /* attempt to rebind */
 191                 goto out;
 192         }
 193         WARN_ON(sk_hashed(sk));
 194         mutex_lock(&port_mutex);
 195         err = sk->sk_prot->get_port(sk, pn_port(handle));
 196         if (err)
 197                 goto out_port;
 198
 199         /* get_port() sets the port, bind() sets the address if applicable */
 200         pn->sobject = pn_object(saddr, pn_port(pn->sobject));
 201         pn->resource = spn->spn_resource;
 202
 203         /* Enable RX on the socket */
 204         sk->sk_prot->hash(sk);
 205 out_port:
 206         mutex_unlock(&port_mutex);
 207 out:
 208         release_sock(sk);
 209         return err;
 210 }
 211
 212 static int pn_socket_autobind(struct socket *sock)
 213 {
 214         struct sockaddr_pn sa;
 215         int err;
 216
 217         memset(&sa, 0, sizeof(sa));
 218         sa.spn_family = AF_PHONET;
 219         err = pn_socket_bind(sock, (struct sockaddr *)&sa,
 220                                 sizeof(struct sockaddr_pn));
 221         if (err != -EINVAL)
 222                 return err;
 223         BUG_ON(!pn_port(pn_sk(sock->sk)->sobject));
 224         return 0; /* socket was already bound */
 225 }
 226
 227 static int pn_socket_accept(struct socket *sock, struct socket *newsock,
 228                                 int flags)
 229 {
 230         struct sock *sk = sock->sk;
 231         struct sock *newsk;
 232         int err;
 233
 234         newsk = sk->sk_prot->accept(sk, flags, &err);
 235         if (!newsk)
 236                 return err;
 237
 238         lock_sock(newsk);
 239         sock_graft(newsk, newsock);
 240         newsock->state = SS_CONNECTED;
 241         release_sock(newsk);
 242         return 0;
 243 }
 244
 245 static int pn_socket_getname(struct socket *sock, struct sockaddr *addr,
 246                                 int *sockaddr_len, int peer)
 247 {
 248         struct sock *sk = sock->sk;
 249         struct pn_sock *pn = pn_sk(sk);
 250
 251         memset(addr, 0, sizeof(struct sockaddr_pn));
 252         addr->sa_family = AF_PHONET;
 253         if (!peer) /* Race with bind() here is userland's problem. */
 254                 pn_sockaddr_set_object((struct sockaddr_pn *)addr,
 255                                         pn->sobject);
 256
 257         *sockaddr_len = sizeof(struct sockaddr_pn);
 258         return 0;
 259 }
 260
 261 static unsigned int pn_socket_poll(struct file *file, struct socket *sock,
 262                                         poll_table *wait)
 263 {
 264         struct sock *sk = sock->sk;
 265         struct pep_sock *pn = pep_sk(sk);
 266         unsigned int mask = 0;
 267
 268         poll_wait(file, sk_sleep(sk), wait);
 269
 270         switch (sk->sk_state) {
 271         case TCP_LISTEN:
 272                 return hlist_empty(&pn->ackq) ? 0 : POLLIN;
 273         case TCP_CLOSE:
 274                 return POLLERR;
 275         }
 276
 277         if (!skb_queue_empty(&sk->sk_receive_queue))
 278                 mask |= POLLIN | POLLRDNORM;
 279         if (!skb_queue_empty(&pn->ctrlreq_queue))
 280                 mask |= POLLPRI;
 281         if (!mask && sk->sk_state == TCP_CLOSE_WAIT)
 282                 return POLLHUP;
 283
 284         if (sk->sk_state == TCP_ESTABLISHED &&
 285                 atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf &&
 286                 atomic_read(&pn->tx_credits))
 287                 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
 288
 289         return mask;
 290 }
 291
 292 static int pn_socket_ioctl(struct socket *sock, unsigned int cmd,
 293                                 unsigned long arg)
 294 {
 295         struct sock *sk = sock->sk;
 296         struct pn_sock *pn = pn_sk(sk);
 297
 298         if (cmd == SIOCPNGETOBJECT) {
 299                 struct net_device *dev;
 300                 u16 handle;
 301                 u8 saddr;
 302
 303                 if (get_user(handle, (__u16 __user *)arg))
 304                         return -EFAULT;
 305
 306                 lock_sock(sk);
 307                 if (sk->sk_bound_dev_if)
 308                         dev = dev_get_by_index(sock_net(sk),
 309                                                 sk->sk_bound_dev_if);
 310                 else
 311                         dev = phonet_device_get(sock_net(sk));
 312                 if (dev && (dev->flags & IFF_UP))
 313                         saddr = phonet_address_get(dev, pn_addr(handle));
 314                 else
 315                         saddr = PN_NO_ADDR;
 316                 release_sock(sk);
 317
 318                 if (dev)
 319                         dev_put(dev);
 320                 if (saddr == PN_NO_ADDR)
 321                         return -EHOSTUNREACH;
 322
 323                 handle = pn_object(saddr, pn_port(pn->sobject));
 324                 return put_user(handle, (__u16 __user *)arg);
 325         }
 326
 327         return sk->sk_prot->ioctl(sk, cmd, arg);
 328 }
 329
 330 static int pn_socket_listen(struct socket *sock, int backlog)
 331 {
 332         struct sock *sk = sock->sk;
 333         int err = 0;
 334
 335         if (sock->state != SS_UNCONNECTED)
 336                 return -EINVAL;
 337         if (pn_socket_autobind(sock))
 338                 return -ENOBUFS;
 339
 340         lock_sock(sk);
 341         if (sk->sk_state != TCP_CLOSE) {
 342                 err = -EINVAL;
 343                 goto out;
 344         }
 345
 346         sk->sk_state = TCP_LISTEN;
 347         sk->sk_ack_backlog = 0;
 348         sk->sk_max_ack_backlog = backlog;
 349 out:
 350         release_sock(sk);
 351         return err;
 352 }
 353
 354 static int pn_socket_sendmsg(struct kiocb *iocb, struct socket *sock,
 355                                 struct msghdr *m, size_t total_len)
 356 {
 357         struct sock *sk = sock->sk;
 358
 359         if (pn_socket_autobind(sock))
 360                 return -EAGAIN;
 361
 362         return sk->sk_prot->sendmsg(iocb, sk, m, total_len);
 363 }
 364
 365 const struct proto_ops phonet_dgram_ops = {
 366         .family         = AF_PHONET,
 367         .owner          = THIS_MODULE,
 368         .release        = pn_socket_release,
 369         .bind           = pn_socket_bind,
 370         .connect        = sock_no_connect,
 371         .socketpair     = sock_no_socketpair,
 372         .accept         = sock_no_accept,
 373         .getname        = pn_socket_getname,
 374         .poll           = datagram_poll,
 375         .ioctl          = pn_socket_ioctl,
 376         .listen         = sock_no_listen,
 377         .shutdown       = sock_no_shutdown,
 378         .setsockopt     = sock_no_setsockopt,
 379         .getsockopt     = sock_no_getsockopt,
 380 #ifdef CONFIG_COMPAT
 381         .compat_setsockopt = sock_no_setsockopt,
 382         .compat_getsockopt = sock_no_getsockopt,
 383 #endif
 384         .sendmsg        = pn_socket_sendmsg,
 385         .recvmsg        = sock_common_recvmsg,
 386         .mmap           = sock_no_mmap,
 387         .sendpage       = sock_no_sendpage,
 388 };
 389
 390 const struct proto_ops phonet_stream_ops = {
 391         .family         = AF_PHONET,
 392         .owner          = THIS_MODULE,
 393         .release        = pn_socket_release,
 394         .bind           = pn_socket_bind,
 395         .connect        = sock_no_connect,
 396         .socketpair     = sock_no_socketpair,
 397         .accept         = pn_socket_accept,
 398         .getname        = pn_socket_getname,
 399         .poll           = pn_socket_poll,
 400         .ioctl          = pn_socket_ioctl,
 401         .listen         = pn_socket_listen,
 402         .shutdown       = sock_no_shutdown,
 403         .setsockopt     = sock_common_setsockopt,
 404         .getsockopt     = sock_common_getsockopt,
 405 #ifdef CONFIG_COMPAT
 406         .compat_setsockopt = compat_sock_common_setsockopt,
 407         .compat_getsockopt = compat_sock_common_getsockopt,
 408 #endif
 409         .sendmsg        = pn_socket_sendmsg,
 410         .recvmsg        = sock_common_recvmsg,
 411         .mmap           = sock_no_mmap,
 412         .sendpage       = sock_no_sendpage,
 413 };
 414 EXPORT_SYMBOL(phonet_stream_ops);
 415
 416 /* allocate port for a socket */
 417 int pn_sock_get_port(struct sock *sk, unsigned short sport)
 418 {
 419         static int port_cur;
 420         struct net *net = sock_net(sk);
 421         struct pn_sock *pn = pn_sk(sk);
 422         struct sockaddr_pn try_sa;
 423         struct sock *tmpsk;
 424
 425         memset(&try_sa, 0, sizeof(struct sockaddr_pn));
 426         try_sa.spn_family = AF_PHONET;
 427         WARN_ON(!mutex_is_locked(&port_mutex));
 428         if (!sport) {
 429                 /* search free port */
 430                 int port, pmin, pmax;
 431
 432                 phonet_get_local_port_range(&pmin, &pmax);
 433                 for (port = pmin; port <= pmax; port++) {
 434                         port_cur++;
 435                         if (port_cur < pmin || port_cur > pmax)
 436                                 port_cur = pmin;
 437
 438                         pn_sockaddr_set_port(&try_sa, port_cur);
 439                         tmpsk = pn_find_sock_by_sa(net, &try_sa);
 440                         if (tmpsk == NULL) {
 441                                 sport = port_cur;
 442                                 goto found;
 443                         } else
 444                                 sock_put(tmpsk);
 445                 }
 446         } else {
 447                 /* try to find specific port */
 448                 pn_sockaddr_set_port(&try_sa, sport);
 449                 tmpsk = pn_find_sock_by_sa(net, &try_sa);
 450                 if (tmpsk == NULL)
 451                         /* No sock there! We can use that port... */
 452                         goto found;
 453                 else
 454                         sock_put(tmpsk);
 455         }
 456         /* the port must be in use already */
 457         return -EADDRINUSE;
 458
 459 found:
 460         pn->sobject = pn_object(pn_addr(pn->sobject), sport);
 461         return 0;
 462 }
 463 EXPORT_SYMBOL(pn_sock_get_port);
 464
 465 #ifdef CONFIG_PROC_FS
 466 static struct sock *pn_sock_get_idx(struct seq_file *seq, loff_t pos)
 467 {
 468         struct net *net = seq_file_net(seq);
 469         struct hlist_head *hlist = pnsocks.hlist;
 470         struct hlist_node *node;
 471         struct sock *sknode;
 472         unsigned h;
 473
 474         for (h = 0; h < PN_HASHSIZE; h++) {
 475                 sk_for_each(sknode, node, hlist) {
 476                         if (!net_eq(net, sock_net(sknode)))
 477                                 continue;
 478                         if (!pos)
 479                                 return sknode;
 480                         pos--;
 481                 }
 482                 hlist++;
 483         }
 484         return NULL;
 485 }
 486
 487 static struct sock *pn_sock_get_next(struct seq_file *seq, struct sock *sk)
 488 {
 489         struct net *net = seq_file_net(seq);
 490
 491         do
 492                 sk = sk_next(sk);
 493         while (sk && !net_eq(net, sock_net(sk)));
 494
 495         return sk;
 496 }
 497
 498 static void *pn_sock_seq_start(struct seq_file *seq, loff_t *pos)
 499         __acquires(pnsocks.lock)
 500 {
 501         spin_lock_bh(&pnsocks.lock);
 502         return *pos ? pn_sock_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 503 }
 504
 505 static void *pn_sock_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 506 {
 507         struct sock *sk;
 508
 509         if (v == SEQ_START_TOKEN)
 510                 sk = pn_sock_get_idx(seq, 0);
 511         else
 512                 sk = pn_sock_get_next(seq, v);
 513         (*pos)++;
 514         return sk;
 515 }
 516
 517 static void pn_sock_seq_stop(struct seq_file *seq, void *v)
 518         __releases(pnsocks.lock)
 519 {
 520         spin_unlock_bh(&pnsocks.lock);
 521 }
 522
 523 static int pn_sock_seq_show(struct seq_file *seq, void *v)
 524 {
 525         int len;
 526
 527         if (v == SEQ_START_TOKEN)
 528                 seq_printf(seq, "%s%n", "pt  loc  rem rs st tx_queue rx_queue "
 529                         "  uid inode ref pointer drops", &len);
 530         else {
 531                 struct sock *sk = v;
 532                 struct pn_sock *pn = pn_sk(sk);
 533
 534                 seq_printf(seq, "%2d %04X:%04X:%02X %02X %08X:%08X %5d %lu "
 535                         "%d %p %d%n",
 536                         sk->sk_protocol, pn->sobject, 0, pn->resource,
 537                         sk->sk_state,
 538                         sk_wmem_alloc_get(sk), sk_rmem_alloc_get(sk),
 539                         sock_i_uid(sk), sock_i_ino(sk),
 540                         atomic_read(&sk->sk_refcnt), sk,
 541                         atomic_read(&sk->sk_drops), &len);
 542         }
 543         seq_printf(seq, "%*s\n", 127 - len, "");
 544         return 0;
 545 }
 546
 547 static const struct seq_operations pn_sock_seq_ops = {
 548         .start = pn_sock_seq_start,
 549         .next = pn_sock_seq_next,
 550         .stop = pn_sock_seq_stop,
 551         .show = pn_sock_seq_show,
 552 };
 553
 554 static int pn_sock_open(struct inode *inode, struct file *file)
 555 {
 556         return seq_open_net(inode, file, &pn_sock_seq_ops,
 557                                 sizeof(struct seq_net_private));
 558 }
 559
 560 const struct file_operations pn_sock_seq_fops = {
 561         .owner = THIS_MODULE,
 562         .open = pn_sock_open,
 563         .read = seq_read,
 564         .llseek = seq_lseek,
 565         .release = seq_release_net,
 566 };
 567 #endif