net/nfc/rawsock.c

   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 #include <net/tcp_states.h>
  25 #include <linux/nfc.h>
  26 #include <linux/export.h>
  27
  28 #include "nfc.h"
  29
  30 static void rawsock_write_queue_purge(struct sock *sk)
  31 {
  32         nfc_dbg("sk=%p", sk);
  33
  34         spin_lock_bh(&sk->sk_write_queue.lock);
  35         __skb_queue_purge(&sk->sk_write_queue);
  36         nfc_rawsock(sk)->tx_work_scheduled = false;
  37         spin_unlock_bh(&sk->sk_write_queue.lock);
  38 }
  39
  40 static void rawsock_report_error(struct sock *sk, int err)
  41 {
  42         nfc_dbg("sk=%p err=%d", sk, err);
  43
  44         sk->sk_shutdown = SHUTDOWN_MASK;
  45         sk->sk_err = -err;
  46         sk->sk_error_report(sk);
  47
  48         rawsock_write_queue_purge(sk);
  49 }
  50
  51 static int rawsock_release(struct socket *sock)
  52 {
  53         struct sock *sk = sock->sk;
  54
  55         nfc_dbg("sock=%p", sock);
  56
  57         sock_orphan(sk);
  58         sock_put(sk);
  59
  60         return 0;
  61 }
  62
  63 static int rawsock_connect(struct socket *sock, struct sockaddr *_addr,
  64                                                         int len, int flags)
  65 {
  66         struct sock *sk = sock->sk;
  67         struct sockaddr_nfc *addr = (struct sockaddr_nfc *)_addr;
  68         struct nfc_dev *dev;
  69         int rc = 0;
  70
  71         nfc_dbg("sock=%p sk=%p flags=%d", sock, sk, flags);
  72
  73         if (!addr || len < sizeof(struct sockaddr_nfc) ||
  74                 addr->sa_family != AF_NFC)
  75                 return -EINVAL;
  76
  77         nfc_dbg("addr dev_idx=%u target_idx=%u protocol=%u", addr->dev_idx,
  78                                         addr->target_idx, addr->nfc_protocol);
  79
  80         lock_sock(sk);
  81
  82         if (sock->state == SS_CONNECTED) {
  83                 rc = -EISCONN;
  84                 goto error;
  85         }
  86
  87         dev = nfc_get_device(addr->dev_idx);
  88         if (!dev) {
  89                 rc = -ENODEV;
  90                 goto error;
  91         }
  92
  93         if (addr->target_idx > dev->target_idx - 1 ||
  94                 addr->target_idx < dev->target_idx - dev->n_targets) {
  95                 rc = -EINVAL;
  96                 goto error;
  97         }
  98
  99         if (addr->target_idx > dev->target_idx - 1 ||
 100                 addr->target_idx < dev->target_idx - dev->n_targets) {
 101                 rc = -EINVAL;
 102                 goto error;
 103         }
 104
 105         rc = nfc_activate_target(dev, addr->target_idx, addr->nfc_protocol);
 106         if (rc)
 107                 goto put_dev;
 108
 109         nfc_rawsock(sk)->dev = dev;
 110         nfc_rawsock(sk)->target_idx = addr->target_idx;
 111         sock->state = SS_CONNECTED;
 112         sk->sk_state = TCP_ESTABLISHED;
 113         sk->sk_state_change(sk);
 114
 115         release_sock(sk);
 116         return 0;
 117
 118 put_dev:
 119         nfc_put_device(dev);
 120 error:
 121         release_sock(sk);
 122         return rc;
 123 }
 124
 125 static int rawsock_add_header(struct sk_buff *skb)
 126 {
 127         *skb_push(skb, NFC_HEADER_SIZE) = 0;
 128
 129         return 0;
 130 }
 131
 132 static void rawsock_data_exchange_complete(void *context, struct sk_buff *skb,
 133                                                                 int err)
 134 {
 135         struct sock *sk = (struct sock *) context;
 136
 137         BUG_ON(in_irq());
 138
 139         nfc_dbg("sk=%p err=%d", sk, err);
 140
 141         if (err)
 142                 goto error;
 143
 144         err = rawsock_add_header(skb);
 145         if (err)
 146                 goto error;
 147
 148         err = sock_queue_rcv_skb(sk, skb);
 149         if (err)
 150                 goto error;
 151
 152         spin_lock_bh(&sk->sk_write_queue.lock);
 153         if (!skb_queue_empty(&sk->sk_write_queue))
 154                 schedule_work(&nfc_rawsock(sk)->tx_work);
 155         else
 156                 nfc_rawsock(sk)->tx_work_scheduled = false;
 157         spin_unlock_bh(&sk->sk_write_queue.lock);
 158
 159         sock_put(sk);
 160         return;
 161
 162 error:
 163         rawsock_report_error(sk, err);
 164         sock_put(sk);
 165 }
 166
 167 static void rawsock_tx_work(struct work_struct *work)
 168 {
 169         struct sock *sk = to_rawsock_sk(work);
 170         struct nfc_dev *dev = nfc_rawsock(sk)->dev;
 171         u32 target_idx = nfc_rawsock(sk)->target_idx;
 172         struct sk_buff *skb;
 173         int rc;
 174
 175         nfc_dbg("sk=%p target_idx=%u", sk, target_idx);
 176
 177         if (sk->sk_shutdown & SEND_SHUTDOWN) {
 178                 rawsock_write_queue_purge(sk);
 179                 return;
 180         }
 181
 182         skb = skb_dequeue(&sk->sk_write_queue);
 183
 184         sock_hold(sk);
 185         rc = nfc_data_exchange(dev, target_idx, skb,
 186                                 rawsock_data_exchange_complete, sk);
 187         if (rc) {
 188                 rawsock_report_error(sk, rc);
 189                 sock_put(sk);
 190         }
 191 }
 192
 193 static int rawsock_sendmsg(struct kiocb *iocb, struct socket *sock,
 194                                         struct msghdr *msg, size_t len)
 195 {
 196         struct sock *sk = sock->sk;
 197         struct nfc_dev *dev = nfc_rawsock(sk)->dev;
 198         struct sk_buff *skb;
 199         int rc;
 200
 201         nfc_dbg("sock=%p sk=%p len=%zu", sock, sk, len);
 202
 203         if (msg->msg_namelen)
 204                 return -EOPNOTSUPP;
 205
 206         if (sock->state != SS_CONNECTED)
 207                 return -ENOTCONN;
 208
 209         skb = sock_alloc_send_skb(sk, len + dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE,
 210                                         msg->msg_flags & MSG_DONTWAIT, &rc);
 211         if (!skb)
 212                 return rc;
 213
 214         skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
 215
 216         rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
 217         if (rc < 0) {
 218                 kfree_skb(skb);
 219                 return rc;
 220         }
 221
 222         spin_lock_bh(&sk->sk_write_queue.lock);
 223         __skb_queue_tail(&sk->sk_write_queue, skb);
 224         if (!nfc_rawsock(sk)->tx_work_scheduled) {
 225                 schedule_work(&nfc_rawsock(sk)->tx_work);
 226                 nfc_rawsock(sk)->tx_work_scheduled = true;
 227         }
 228         spin_unlock_bh(&sk->sk_write_queue.lock);
 229
 230         return len;
 231 }
 232
 233 static int rawsock_recvmsg(struct kiocb *iocb, struct socket *sock,
 234                                 struct msghdr *msg, size_t len, int flags)
 235 {
 236         int noblock = flags & MSG_DONTWAIT;
 237         struct sock *sk = sock->sk;
 238         struct sk_buff *skb;
 239         int copied;
 240         int rc;
 241
 242         nfc_dbg("sock=%p sk=%p len=%zu flags=%d", sock, sk, len, flags);
 243
 244         skb = skb_recv_datagram(sk, flags, noblock, &rc);
 245         if (!skb)
 246                 return rc;
 247
 248         msg->msg_namelen = 0;
 249
 250         copied = skb->len;
 251         if (len < copied) {
 252                 msg->msg_flags |= MSG_TRUNC;
 253                 copied = len;
 254         }
 255
 256         rc = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 257
 258         skb_free_datagram(sk, skb);
 259
 260         return rc ? : copied;
 261 }
 262
 263
 264 static const struct proto_ops rawsock_ops = {
 265         .family         = PF_NFC,
 266         .owner          = THIS_MODULE,
 267         .release        = rawsock_release,
 268         .bind           = sock_no_bind,
 269         .connect        = rawsock_connect,
 270         .socketpair     = sock_no_socketpair,
 271         .accept         = sock_no_accept,
 272         .getname        = sock_no_getname,
 273         .poll           = datagram_poll,
 274         .ioctl          = sock_no_ioctl,
 275         .listen         = sock_no_listen,
 276         .shutdown       = sock_no_shutdown,
 277         .setsockopt     = sock_no_setsockopt,
 278         .getsockopt     = sock_no_getsockopt,
 279         .sendmsg        = rawsock_sendmsg,
 280         .recvmsg        = rawsock_recvmsg,
 281         .mmap           = sock_no_mmap,
 282 };
 283
 284 static void rawsock_destruct(struct sock *sk)
 285 {
 286         nfc_dbg("sk=%p", sk);
 287
 288         if (sk->sk_state == TCP_ESTABLISHED) {
 289                 nfc_deactivate_target(nfc_rawsock(sk)->dev,
 290                                         nfc_rawsock(sk)->target_idx);
 291                 nfc_put_device(nfc_rawsock(sk)->dev);
 292         }
 293
 294         skb_queue_purge(&sk->sk_receive_queue);
 295
 296         if (!sock_flag(sk, SOCK_DEAD)) {
 297                 nfc_err("Freeing alive NFC raw socket %p", sk);
 298                 return;
 299         }
 300 }
 301
 302 static int rawsock_create(struct net *net, struct socket *sock,
 303                                 const struct nfc_protocol *nfc_proto)
 304 {
 305         struct sock *sk;
 306
 307         nfc_dbg("sock=%p", sock);
 308
 309         if (sock->type != SOCK_SEQPACKET)
 310                 return -ESOCKTNOSUPPORT;
 311
 312         sock->ops = &rawsock_ops;
 313
 314         sk = sk_alloc(net, PF_NFC, GFP_KERNEL, nfc_proto->proto);
 315         if (!sk)
 316                 return -ENOMEM;
 317
 318         sock_init_data(sock, sk);
 319         sk->sk_protocol = nfc_proto->id;
 320         sk->sk_destruct = rawsock_destruct;
 321         sock->state = SS_UNCONNECTED;
 322
 323         INIT_WORK(&nfc_rawsock(sk)->tx_work, rawsock_tx_work);
 324         nfc_rawsock(sk)->tx_work_scheduled = false;
 325
 326         return 0;
 327 }
 328
 329 static struct proto rawsock_proto = {
 330         .name     = "NFC_RAW",
 331         .owner    = THIS_MODULE,
 332         .obj_size = sizeof(struct nfc_rawsock),
 333 };
 334
 335 static const struct nfc_protocol rawsock_nfc_proto = {
 336         .id       = NFC_SOCKPROTO_RAW,
 337         .proto    = &rawsock_proto,
 338         .owner    = THIS_MODULE,
 339         .create   = rawsock_create
 340 };
 341
 342 int __init rawsock_init(void)
 343 {
 344         int rc;
 345
 346         rc = nfc_proto_register(&rawsock_nfc_proto);
 347
 348         return rc;
 349 }
 350
 351 void rawsock_exit(void)
 352 {
 353         nfc_proto_unregister(&rawsock_nfc_proto);
 354 }