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
  27 #include "nfc.h"
  28
  29 static void rawsock_write_queue_purge(struct sock *sk)
  30 {
  31         nfc_dbg("sk=%p", sk);
  32
  33         spin_lock_bh(&sk->sk_write_queue.lock);
  34         __skb_queue_purge(&sk->sk_write_queue);
  35         nfc_rawsock(sk)->tx_work_scheduled = false;
  36         spin_unlock_bh(&sk->sk_write_queue.lock);
  37 }
  38
  39 static void rawsock_report_error(struct sock *sk, int err)
  40 {
  41         nfc_dbg("sk=%p err=%d", sk, err);
  42
  43         sk->sk_shutdown = SHUTDOWN_MASK;
  44         sk->sk_err = -err;
  45         sk->sk_error_report(sk);
  46
  47         rawsock_write_queue_purge(sk);
  48 }
  49
  50 static int rawsock_release(struct socket *sock)
  51 {
  52         struct sock *sk = sock->sk;
  53
  54         nfc_dbg("sock=%p", sock);
  55
  56         sock_orphan(sk);
  57         sock_put(sk);
  58
  59         return 0;
  60 }
  61
  62 static int rawsock_connect(struct socket *sock, struct sockaddr *_addr,
  63                                                         int len, int flags)
  64 {
  65         struct sock *sk = sock->sk;
  66         struct sockaddr_nfc *addr = (struct sockaddr_nfc *)_addr;
  67         struct nfc_dev *dev;
  68         int rc = 0;
  69
  70         nfc_dbg("sock=%p sk=%p flags=%d", sock, sk, flags);
  71
  72         if (!addr || len < sizeof(struct sockaddr_nfc) ||
  73                 addr->sa_family != AF_NFC)
  74                 return -EINVAL;
  75
  76         nfc_dbg("addr dev_idx=%u target_idx=%u protocol=%u", addr->dev_idx,
  77                                         addr->target_idx, addr->nfc_protocol);
  78
  79         lock_sock(sk);
  80
  81         if (sock->state == SS_CONNECTED) {
  82                 rc = -EISCONN;
  83                 goto error;
  84         }
  85
  86         dev = nfc_get_device(addr->dev_idx);
  87         if (!dev) {
  88                 rc = -ENODEV;
  89                 goto error;
  90         }
  91
  92         if (addr->target_idx > dev->target_idx - 1 ||
  93                 addr->target_idx < dev->target_idx - dev->n_targets) {
  94                 rc = -EINVAL;
  95                 goto error;
  96         }
  97
  98         if (addr->target_idx > dev->target_idx - 1 ||
  99                 addr->target_idx < dev->target_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
 117 put_dev:
 118         nfc_put_device(dev);
 119 error:
 120         release_sock(sk);
 121         return rc;
 122 }
 123
 124 static int rawsock_add_header(struct sk_buff *skb)
 125 {
 126
 127         if (skb_cow_head(skb, 1))
 128                 return -ENOMEM;
 129
 130         *skb_push(skb, 1) = 0;
 131
 132         return 0;
 133 }
 134
 135 static void rawsock_data_exchange_complete(void *context, struct sk_buff *skb,
 136                                                                 int err)
 137 {
 138         struct sock *sk = (struct sock *) context;
 139
 140         BUG_ON(in_irq());
 141
 142         nfc_dbg("sk=%p err=%d", sk, err);
 143
 144         if (err)
 145                 goto error;
 146
 147         err = rawsock_add_header(skb);
 148         if (err)
 149                 goto error;
 150
 151         err = sock_queue_rcv_skb(sk, skb);
 152         if (err)
 153                 goto error;
 154
 155         spin_lock_bh(&sk->sk_write_queue.lock);
 156         if (!skb_queue_empty(&sk->sk_write_queue))
 157                 schedule_work(&nfc_rawsock(sk)->tx_work);
 158         else
 159                 nfc_rawsock(sk)->tx_work_scheduled = false;
 160         spin_unlock_bh(&sk->sk_write_queue.lock);
 161
 162         sock_put(sk);
 163         return;
 164
 165 error:
 166         rawsock_report_error(sk, err);
 167         sock_put(sk);
 168 }
 169
 170 static void rawsock_tx_work(struct work_struct *work)
 171 {
 172         struct sock *sk = to_rawsock_sk(work);
 173         struct nfc_dev *dev = nfc_rawsock(sk)->dev;
 174         u32 target_idx = nfc_rawsock(sk)->target_idx;
 175         struct sk_buff *skb;
 176         int rc;
 177
 178         nfc_dbg("sk=%p target_idx=%u", sk, target_idx);
 179
 180         if (sk->sk_shutdown & SEND_SHUTDOWN) {
 181                 rawsock_write_queue_purge(sk);
 182                 return;
 183         }
 184
 185         skb = skb_dequeue(&sk->sk_write_queue);
 186
 187         sock_hold(sk);
 188         rc = nfc_data_exchange(dev, target_idx, skb,
 189                                 rawsock_data_exchange_complete, sk);
 190         if (rc) {
 191                 rawsock_report_error(sk, rc);
 192                 sock_put(sk);
 193         }
 194 }
 195
 196 static int rawsock_sendmsg(struct kiocb *iocb, struct socket *sock,
 197                                         struct msghdr *msg, size_t len)
 198 {
 199         struct sock *sk = sock->sk;
 200         struct sk_buff *skb;
 201         int rc;
 202
 203         nfc_dbg("sock=%p sk=%p len=%zu", sock, sk, len);
 204
 205         if (msg->msg_namelen)
 206                 return -EOPNOTSUPP;
 207
 208         if (sock->state != SS_CONNECTED)
 209                 return -ENOTCONN;
 210
 211         skb = sock_alloc_send_skb(sk, len, msg->msg_flags & MSG_DONTWAIT,
 212                                                                         &rc);
 213         if (!skb)
 214                 return rc;
 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 }