linux/net/phonet/socket.c
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   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
  38static 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
  53static struct  {
  54        struct hlist_head hlist[PN_HASHSIZE];
  55        spinlock_t lock;
  56} pnsocks;
  57
  58void __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
  67static 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 */
  76struct 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) */
 117void 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
 146void 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}
 154EXPORT_SYMBOL(pn_sock_hash);
 155
 156void 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}
 162EXPORT_SYMBOL(pn_sock_unhash);
 163
 164static DEFINE_MUTEX(port_mutex);
 165
 166static 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);
 205out_port:
 206        mutex_unlock(&port_mutex);
 207out:
 208        release_sock(sk);
 209        return err;
 210}
 211
 212static 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
 227static 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
 245static 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
 261static 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 && atomic_read(&pn->tx_credits))
 285                mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
 286
 287        return mask;
 288}
 289
 290static int pn_socket_ioctl(struct socket *sock, unsigned int cmd,
 291                                unsigned long arg)
 292{
 293        struct sock *sk = sock->sk;
 294        struct pn_sock *pn = pn_sk(sk);
 295
 296        if (cmd == SIOCPNGETOBJECT) {
 297                struct net_device *dev;
 298                u16 handle;
 299                u8 saddr;
 300
 301                if (get_user(handle, (__u16 __user *)arg))
 302                        return -EFAULT;
 303
 304                lock_sock(sk);
 305                if (sk->sk_bound_dev_if)
 306                        dev = dev_get_by_index(sock_net(sk),
 307                                                sk->sk_bound_dev_if);
 308                else
 309                        dev = phonet_device_get(sock_net(sk));
 310                if (dev && (dev->flags & IFF_UP))
 311                        saddr = phonet_address_get(dev, pn_addr(handle));
 312                else
 313                        saddr = PN_NO_ADDR;
 314                release_sock(sk);
 315
 316                if (dev)
 317                        dev_put(dev);
 318                if (saddr == PN_NO_ADDR)
 319                        return -EHOSTUNREACH;
 320
 321                handle = pn_object(saddr, pn_port(pn->sobject));
 322                return put_user(handle, (__u16 __user *)arg);
 323        }
 324
 325        return sk->sk_prot->ioctl(sk, cmd, arg);
 326}
 327
 328static int pn_socket_listen(struct socket *sock, int backlog)
 329{
 330        struct sock *sk = sock->sk;
 331        int err = 0;
 332
 333        if (sock->state != SS_UNCONNECTED)
 334                return -EINVAL;
 335        if (pn_socket_autobind(sock))
 336                return -ENOBUFS;
 337
 338        lock_sock(sk);
 339        if (sk->sk_state != TCP_CLOSE) {
 340                err = -EINVAL;
 341                goto out;
 342        }
 343
 344        sk->sk_state = TCP_LISTEN;
 345        sk->sk_ack_backlog = 0;
 346        sk->sk_max_ack_backlog = backlog;
 347out:
 348        release_sock(sk);
 349        return err;
 350}
 351
 352static int pn_socket_sendmsg(struct kiocb *iocb, struct socket *sock,
 353                                struct msghdr *m, size_t total_len)
 354{
 355        struct sock *sk = sock->sk;
 356
 357        if (pn_socket_autobind(sock))
 358                return -EAGAIN;
 359
 360        return sk->sk_prot->sendmsg(iocb, sk, m, total_len);
 361}
 362
 363const struct proto_ops phonet_dgram_ops = {
 364        .family         = AF_PHONET,
 365        .owner          = THIS_MODULE,
 366        .release        = pn_socket_release,
 367        .bind           = pn_socket_bind,
 368        .connect        = sock_no_connect,
 369        .socketpair     = sock_no_socketpair,
 370        .accept         = sock_no_accept,
 371        .getname        = pn_socket_getname,
 372        .poll           = datagram_poll,
 373        .ioctl          = pn_socket_ioctl,
 374        .listen         = sock_no_listen,
 375        .shutdown       = sock_no_shutdown,
 376        .setsockopt     = sock_no_setsockopt,
 377        .getsockopt     = sock_no_getsockopt,
 378#ifdef CONFIG_COMPAT
 379        .compat_setsockopt = sock_no_setsockopt,
 380        .compat_getsockopt = sock_no_getsockopt,
 381#endif
 382        .sendmsg        = pn_socket_sendmsg,
 383        .recvmsg        = sock_common_recvmsg,
 384        .mmap           = sock_no_mmap,
 385        .sendpage       = sock_no_sendpage,
 386};
 387
 388const struct proto_ops phonet_stream_ops = {
 389        .family         = AF_PHONET,
 390        .owner          = THIS_MODULE,
 391        .release        = pn_socket_release,
 392        .bind           = pn_socket_bind,
 393        .connect        = sock_no_connect,
 394        .socketpair     = sock_no_socketpair,
 395        .accept         = pn_socket_accept,
 396        .getname        = pn_socket_getname,
 397        .poll           = pn_socket_poll,
 398        .ioctl          = pn_socket_ioctl,
 399        .listen         = pn_socket_listen,
 400        .shutdown       = sock_no_shutdown,
 401        .setsockopt     = sock_common_setsockopt,
 402        .getsockopt     = sock_common_getsockopt,
 403#ifdef CONFIG_COMPAT
 404        .compat_setsockopt = compat_sock_common_setsockopt,
 405        .compat_getsockopt = compat_sock_common_getsockopt,
 406#endif
 407        .sendmsg        = pn_socket_sendmsg,
 408        .recvmsg        = sock_common_recvmsg,
 409        .mmap           = sock_no_mmap,
 410        .sendpage       = sock_no_sendpage,
 411};
 412EXPORT_SYMBOL(phonet_stream_ops);
 413
 414/* allocate port for a socket */
 415int pn_sock_get_port(struct sock *sk, unsigned short sport)
 416{
 417        static int port_cur;
 418        struct net *net = sock_net(sk);
 419        struct pn_sock *pn = pn_sk(sk);
 420        struct sockaddr_pn try_sa;
 421        struct sock *tmpsk;
 422
 423        memset(&try_sa, 0, sizeof(struct sockaddr_pn));
 424        try_sa.spn_family = AF_PHONET;
 425        WARN_ON(!mutex_is_locked(&port_mutex));
 426        if (!sport) {
 427                /* search free port */
 428                int port, pmin, pmax;
 429
 430                phonet_get_local_port_range(&pmin, &pmax);
 431                for (port = pmin; port <= pmax; port++) {
 432                        port_cur++;
 433                        if (port_cur < pmin || port_cur > pmax)
 434                                port_cur = pmin;
 435
 436                        pn_sockaddr_set_port(&try_sa, port_cur);
 437                        tmpsk = pn_find_sock_by_sa(net, &try_sa);
 438                        if (tmpsk == NULL) {
 439                                sport = port_cur;
 440                                goto found;
 441                        } else
 442                                sock_put(tmpsk);
 443                }
 444        } else {
 445                /* try to find specific port */
 446                pn_sockaddr_set_port(&try_sa, sport);
 447                tmpsk = pn_find_sock_by_sa(net, &try_sa);
 448                if (tmpsk == NULL)
 449                        /* No sock there! We can use that port... */
 450                        goto found;
 451                else
 452                        sock_put(tmpsk);
 453        }
 454        /* the port must be in use already */
 455        return -EADDRINUSE;
 456
 457found:
 458        pn->sobject = pn_object(pn_addr(pn->sobject), sport);
 459        return 0;
 460}
 461EXPORT_SYMBOL(pn_sock_get_port);
 462
 463#ifdef CONFIG_PROC_FS
 464static struct sock *pn_sock_get_idx(struct seq_file *seq, loff_t pos)
 465{
 466        struct net *net = seq_file_net(seq);
 467        struct hlist_head *hlist = pnsocks.hlist;
 468        struct hlist_node *node;
 469        struct sock *sknode;
 470        unsigned h;
 471
 472        for (h = 0; h < PN_HASHSIZE; h++) {
 473                sk_for_each(sknode, node, hlist) {
 474                        if (!net_eq(net, sock_net(sknode)))
 475                                continue;
 476                        if (!pos)
 477                                return sknode;
 478                        pos--;
 479                }
 480                hlist++;
 481        }
 482        return NULL;
 483}
 484
 485static struct sock *pn_sock_get_next(struct seq_file *seq, struct sock *sk)
 486{
 487        struct net *net = seq_file_net(seq);
 488
 489        do
 490                sk = sk_next(sk);
 491        while (sk && !net_eq(net, sock_net(sk)));
 492
 493        return sk;
 494}
 495
 496static void *pn_sock_seq_start(struct seq_file *seq, loff_t *pos)
 497        __acquires(pnsocks.lock)
 498{
 499        spin_lock_bh(&pnsocks.lock);
 500        return *pos ? pn_sock_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 501}
 502
 503static void *pn_sock_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 504{
 505        struct sock *sk;
 506
 507        if (v == SEQ_START_TOKEN)
 508                sk = pn_sock_get_idx(seq, 0);
 509        else
 510                sk = pn_sock_get_next(seq, v);
 511        (*pos)++;
 512        return sk;
 513}
 514
 515static void pn_sock_seq_stop(struct seq_file *seq, void *v)
 516        __releases(pnsocks.lock)
 517{
 518        spin_unlock_bh(&pnsocks.lock);
 519}
 520
 521static int pn_sock_seq_show(struct seq_file *seq, void *v)
 522{
 523        int len;
 524
 525        if (v == SEQ_START_TOKEN)
 526                seq_printf(seq, "%s%n", "pt  loc  rem rs st tx_queue rx_queue "
 527                        "  uid inode ref pointer drops", &len);
 528        else {
 529                struct sock *sk = v;
 530                struct pn_sock *pn = pn_sk(sk);
 531
 532                seq_printf(seq, "%2d %04X:%04X:%02X %02X %08X:%08X %5d %lu "
 533                        "%d %p %d%n",
 534                        sk->sk_protocol, pn->sobject, 0, pn->resource,
 535                        sk->sk_state,
 536                        sk_wmem_alloc_get(sk), sk_rmem_alloc_get(sk),
 537                        sock_i_uid(sk), sock_i_ino(sk),
 538                        atomic_read(&sk->sk_refcnt), sk,
 539                        atomic_read(&sk->sk_drops), &len);
 540        }
 541        seq_printf(seq, "%*s\n", 127 - len, "");
 542        return 0;
 543}
 544
 545static const struct seq_operations pn_sock_seq_ops = {
 546        .start = pn_sock_seq_start,
 547        .next = pn_sock_seq_next,
 548        .stop = pn_sock_seq_stop,
 549        .show = pn_sock_seq_show,
 550};
 551
 552static int pn_sock_open(struct inode *inode, struct file *file)
 553{
 554        return seq_open_net(inode, file, &pn_sock_seq_ops,
 555                                sizeof(struct seq_net_private));
 556}
 557
 558const struct file_operations pn_sock_seq_fops = {
 559        .owner = THIS_MODULE,
 560        .open = pn_sock_open,
 561        .read = seq_read,
 562        .llseek = seq_lseek,
 563        .release = seq_release_net,
 564};
 565#endif
 566