linux/net/nfc/rawsock.c
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   1/*
   2 * Copyright (C) 2011 Instituto Nokia de Tecnologia
   3 *
   4 * Authors:
   5 *    Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
   6 *    Lauro Ramos Venancio <lauro.venancio@openbossa.org>
   7 *
   8 * This program is free software; you can redistribute it and/or modify
   9 * it under the terms of the GNU General Public License as published by
  10 * the Free Software Foundation; either version 2 of the License, or
  11 * (at your option) any later version.
  12 *
  13 * This program is distributed in the hope that it will be useful,
  14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16 * GNU General Public License for more details.
  17 *
  18 * You should have received a copy of the GNU General Public License
  19 * along with this program; if not, write to the
  20 * Free Software Foundation, Inc.,
  21 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  22 */
  23
  24#define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__
  25
  26#include <net/tcp_states.h>
  27#include <linux/nfc.h>
  28#include <linux/export.h>
  29
  30#include "nfc.h"
  31
  32static void rawsock_write_queue_purge(struct sock *sk)
  33{
  34        pr_debug("sk=%p\n", sk);
  35
  36        spin_lock_bh(&sk->sk_write_queue.lock);
  37        __skb_queue_purge(&sk->sk_write_queue);
  38        nfc_rawsock(sk)->tx_work_scheduled = false;
  39        spin_unlock_bh(&sk->sk_write_queue.lock);
  40}
  41
  42static void rawsock_report_error(struct sock *sk, int err)
  43{
  44        pr_debug("sk=%p err=%d\n", sk, err);
  45
  46        sk->sk_shutdown = SHUTDOWN_MASK;
  47        sk->sk_err = -err;
  48        sk->sk_error_report(sk);
  49
  50        rawsock_write_queue_purge(sk);
  51}
  52
  53static int rawsock_release(struct socket *sock)
  54{
  55        struct sock *sk = sock->sk;
  56
  57        pr_debug("sock=%p sk=%p\n", sock, sk);
  58
  59        if (!sk)
  60                return 0;
  61
  62        sock_orphan(sk);
  63        sock_put(sk);
  64
  65        return 0;
  66}
  67
  68static int rawsock_connect(struct socket *sock, struct sockaddr *_addr,
  69                           int len, int flags)
  70{
  71        struct sock *sk = sock->sk;
  72        struct sockaddr_nfc *addr = (struct sockaddr_nfc *)_addr;
  73        struct nfc_dev *dev;
  74        int rc = 0;
  75
  76        pr_debug("sock=%p sk=%p flags=%d\n", sock, sk, flags);
  77
  78        if (!addr || len < sizeof(struct sockaddr_nfc) ||
  79            addr->sa_family != AF_NFC)
  80                return -EINVAL;
  81
  82        pr_debug("addr dev_idx=%u target_idx=%u protocol=%u\n",
  83                 addr->dev_idx, addr->target_idx, addr->nfc_protocol);
  84
  85        lock_sock(sk);
  86
  87        if (sock->state == SS_CONNECTED) {
  88                rc = -EISCONN;
  89                goto error;
  90        }
  91
  92        dev = nfc_get_device(addr->dev_idx);
  93        if (!dev) {
  94                rc = -ENODEV;
  95                goto error;
  96        }
  97
  98        if (addr->target_idx > dev->target_next_idx - 1 ||
  99            addr->target_idx < dev->target_next_idx - dev->n_targets) {
 100                rc = -EINVAL;
 101                goto error;
 102        }
 103
 104        rc = nfc_activate_target(dev, addr->target_idx, addr->nfc_protocol);
 105        if (rc)
 106                goto put_dev;
 107
 108        nfc_rawsock(sk)->dev = dev;
 109        nfc_rawsock(sk)->target_idx = addr->target_idx;
 110        sock->state = SS_CONNECTED;
 111        sk->sk_state = TCP_ESTABLISHED;
 112        sk->sk_state_change(sk);
 113
 114        release_sock(sk);
 115        return 0;
 116
 117put_dev:
 118        nfc_put_device(dev);
 119error:
 120        release_sock(sk);
 121        return rc;
 122}
 123
 124static int rawsock_add_header(struct sk_buff *skb)
 125{
 126        *skb_push(skb, NFC_HEADER_SIZE) = 0;
 127
 128        return 0;
 129}
 130
 131static void rawsock_data_exchange_complete(void *context, struct sk_buff *skb,
 132                                           int err)
 133{
 134        struct sock *sk = (struct sock *) context;
 135
 136        BUG_ON(in_irq());
 137
 138        pr_debug("sk=%p err=%d\n", sk, err);
 139
 140        if (err)
 141                goto error;
 142
 143        err = rawsock_add_header(skb);
 144        if (err)
 145                goto error;
 146
 147        err = sock_queue_rcv_skb(sk, skb);
 148        if (err)
 149                goto error;
 150
 151        spin_lock_bh(&sk->sk_write_queue.lock);
 152        if (!skb_queue_empty(&sk->sk_write_queue))
 153                schedule_work(&nfc_rawsock(sk)->tx_work);
 154        else
 155                nfc_rawsock(sk)->tx_work_scheduled = false;
 156        spin_unlock_bh(&sk->sk_write_queue.lock);
 157
 158        sock_put(sk);
 159        return;
 160
 161error:
 162        rawsock_report_error(sk, err);
 163        sock_put(sk);
 164}
 165
 166static void rawsock_tx_work(struct work_struct *work)
 167{
 168        struct sock *sk = to_rawsock_sk(work);
 169        struct nfc_dev *dev = nfc_rawsock(sk)->dev;
 170        u32 target_idx = nfc_rawsock(sk)->target_idx;
 171        struct sk_buff *skb;
 172        int rc;
 173
 174        pr_debug("sk=%p target_idx=%u\n", sk, target_idx);
 175
 176        if (sk->sk_shutdown & SEND_SHUTDOWN) {
 177                rawsock_write_queue_purge(sk);
 178                return;
 179        }
 180
 181        skb = skb_dequeue(&sk->sk_write_queue);
 182
 183        sock_hold(sk);
 184        rc = nfc_data_exchange(dev, target_idx, skb,
 185                               rawsock_data_exchange_complete, sk);
 186        if (rc) {
 187                rawsock_report_error(sk, rc);
 188                sock_put(sk);
 189        }
 190}
 191
 192static int rawsock_sendmsg(struct kiocb *iocb, struct socket *sock,
 193                           struct msghdr *msg, size_t len)
 194{
 195        struct sock *sk = sock->sk;
 196        struct nfc_dev *dev = nfc_rawsock(sk)->dev;
 197        struct sk_buff *skb;
 198        int rc;
 199
 200        pr_debug("sock=%p sk=%p len=%zu\n", sock, sk, len);
 201
 202        if (msg->msg_namelen)
 203                return -EOPNOTSUPP;
 204
 205        if (sock->state != SS_CONNECTED)
 206                return -ENOTCONN;
 207
 208        skb = nfc_alloc_send_skb(dev, sk, msg->msg_flags, len, &rc);
 209        if (skb == NULL)
 210                return rc;
 211
 212        rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
 213        if (rc < 0) {
 214                kfree_skb(skb);
 215                return rc;
 216        }
 217
 218        spin_lock_bh(&sk->sk_write_queue.lock);
 219        __skb_queue_tail(&sk->sk_write_queue, skb);
 220        if (!nfc_rawsock(sk)->tx_work_scheduled) {
 221                schedule_work(&nfc_rawsock(sk)->tx_work);
 222                nfc_rawsock(sk)->tx_work_scheduled = true;
 223        }
 224        spin_unlock_bh(&sk->sk_write_queue.lock);
 225
 226        return len;
 227}
 228
 229static int rawsock_recvmsg(struct kiocb *iocb, struct socket *sock,
 230                           struct msghdr *msg, size_t len, int flags)
 231{
 232        int noblock = flags & MSG_DONTWAIT;
 233        struct sock *sk = sock->sk;
 234        struct sk_buff *skb;
 235        int copied;
 236        int rc;
 237
 238        pr_debug("sock=%p sk=%p len=%zu flags=%d\n", sock, sk, len, flags);
 239
 240        skb = skb_recv_datagram(sk, flags, noblock, &rc);
 241        if (!skb)
 242                return rc;
 243
 244        msg->msg_namelen = 0;
 245
 246        copied = skb->len;
 247        if (len < copied) {
 248                msg->msg_flags |= MSG_TRUNC;
 249                copied = len;
 250        }
 251
 252        rc = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 253
 254        skb_free_datagram(sk, skb);
 255
 256        return rc ? : copied;
 257}
 258
 259
 260static const struct proto_ops rawsock_ops = {
 261        .family         = PF_NFC,
 262        .owner          = THIS_MODULE,
 263        .release        = rawsock_release,
 264        .bind           = sock_no_bind,
 265        .connect        = rawsock_connect,
 266        .socketpair     = sock_no_socketpair,
 267        .accept         = sock_no_accept,
 268        .getname        = sock_no_getname,
 269        .poll           = datagram_poll,
 270        .ioctl          = sock_no_ioctl,
 271        .listen         = sock_no_listen,
 272        .shutdown       = sock_no_shutdown,
 273        .setsockopt     = sock_no_setsockopt,
 274        .getsockopt     = sock_no_getsockopt,
 275        .sendmsg        = rawsock_sendmsg,
 276        .recvmsg        = rawsock_recvmsg,
 277        .mmap           = sock_no_mmap,
 278};
 279
 280static void rawsock_destruct(struct sock *sk)
 281{
 282        pr_debug("sk=%p\n", sk);
 283
 284        if (sk->sk_state == TCP_ESTABLISHED) {
 285                nfc_deactivate_target(nfc_rawsock(sk)->dev,
 286                                      nfc_rawsock(sk)->target_idx);
 287                nfc_put_device(nfc_rawsock(sk)->dev);
 288        }
 289
 290        skb_queue_purge(&sk->sk_receive_queue);
 291
 292        if (!sock_flag(sk, SOCK_DEAD)) {
 293                pr_err("Freeing alive NFC raw socket %p\n", sk);
 294                return;
 295        }
 296}
 297
 298static int rawsock_create(struct net *net, struct socket *sock,
 299                          const struct nfc_protocol *nfc_proto)
 300{
 301        struct sock *sk;
 302
 303        pr_debug("sock=%p\n", sock);
 304
 305        if (sock->type != SOCK_SEQPACKET)
 306                return -ESOCKTNOSUPPORT;
 307
 308        sock->ops = &rawsock_ops;
 309
 310        sk = sk_alloc(net, PF_NFC, GFP_ATOMIC, nfc_proto->proto);
 311        if (!sk)
 312                return -ENOMEM;
 313
 314        sock_init_data(sock, sk);
 315        sk->sk_protocol = nfc_proto->id;
 316        sk->sk_destruct = rawsock_destruct;
 317        sock->state = SS_UNCONNECTED;
 318
 319        INIT_WORK(&nfc_rawsock(sk)->tx_work, rawsock_tx_work);
 320        nfc_rawsock(sk)->tx_work_scheduled = false;
 321
 322        return 0;
 323}
 324
 325static struct proto rawsock_proto = {
 326        .name     = "NFC_RAW",
 327        .owner    = THIS_MODULE,
 328        .obj_size = sizeof(struct nfc_rawsock),
 329};
 330
 331static const struct nfc_protocol rawsock_nfc_proto = {
 332        .id       = NFC_SOCKPROTO_RAW,
 333        .proto    = &rawsock_proto,
 334        .owner    = THIS_MODULE,
 335        .create   = rawsock_create
 336};
 337
 338int __init rawsock_init(void)
 339{
 340        int rc;
 341
 342        rc = nfc_proto_register(&rawsock_nfc_proto);
 343
 344        return rc;
 345}
 346
 347void rawsock_exit(void)
 348{
 349        nfc_proto_unregister(&rawsock_nfc_proto);
 350}
 351
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