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 #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
  32 static 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
  42 static 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
  53 static 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
  68 static 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
 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         *skb_push(skb, NFC_HEADER_SIZE) = 0;
 127
 128         return 0;
 129 }
 130
 131 static 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_skb;
 146
 147         err = sock_queue_rcv_skb(sk, skb);
 148         if (err)
 149                 goto error_skb;
 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
 161 error_skb:
 162         kfree_skb(skb);
 163
 164 error:
 165         rawsock_report_error(sk, err);
 166         sock_put(sk);
 167 }
 168
 169 static void rawsock_tx_work(struct work_struct *work)
 170 {
 171         struct sock *sk = to_rawsock_sk(work);
 172         struct nfc_dev *dev = nfc_rawsock(sk)->dev;
 173         u32 target_idx = nfc_rawsock(sk)->target_idx;
 174         struct sk_buff *skb;
 175         int rc;
 176
 177         pr_debug("sk=%p target_idx=%u\n", sk, target_idx);
 178
 179         if (sk->sk_shutdown & SEND_SHUTDOWN) {
 180                 rawsock_write_queue_purge(sk);
 181                 return;
 182         }
 183
 184         skb = skb_dequeue(&sk->sk_write_queue);
 185
 186         sock_hold(sk);
 187         rc = nfc_data_exchange(dev, target_idx, skb,
 188                                rawsock_data_exchange_complete, sk);
 189         if (rc) {
 190                 rawsock_report_error(sk, rc);
 191                 sock_put(sk);
 192         }
 193 }
 194
 195 static int rawsock_sendmsg(struct kiocb *iocb, struct socket *sock,
 196                            struct msghdr *msg, size_t len)
 197 {
 198         struct sock *sk = sock->sk;
 199         struct nfc_dev *dev = nfc_rawsock(sk)->dev;
 200         struct sk_buff *skb;
 201         int rc;
 202
 203         pr_debug("sock=%p sk=%p len=%zu\n", 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 = nfc_alloc_send_skb(dev, sk, msg->msg_flags, len, &rc);
 212         if (skb == NULL)
 213                 return rc;
 214
 215         rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
 216         if (rc < 0) {
 217                 kfree_skb(skb);
 218                 return rc;
 219         }
 220
 221         spin_lock_bh(&sk->sk_write_queue.lock);
 222         __skb_queue_tail(&sk->sk_write_queue, skb);
 223         if (!nfc_rawsock(sk)->tx_work_scheduled) {
 224                 schedule_work(&nfc_rawsock(sk)->tx_work);
 225                 nfc_rawsock(sk)->tx_work_scheduled = true;
 226         }
 227         spin_unlock_bh(&sk->sk_write_queue.lock);
 228
 229         return len;
 230 }
 231
 232 static int rawsock_recvmsg(struct kiocb *iocb, struct socket *sock,
 233                            struct msghdr *msg, size_t len, int flags)
 234 {
 235         int noblock = flags & MSG_DONTWAIT;
 236         struct sock *sk = sock->sk;
 237         struct sk_buff *skb;
 238         int copied;
 239         int rc;
 240
 241         pr_debug("sock=%p sk=%p len=%zu flags=%d\n", sock, sk, len, flags);
 242
 243         skb = skb_recv_datagram(sk, flags, noblock, &rc);
 244         if (!skb)
 245                 return rc;
 246
 247         msg->msg_namelen = 0;
 248
 249         copied = skb->len;
 250         if (len < copied) {
 251                 msg->msg_flags |= MSG_TRUNC;
 252                 copied = len;
 253         }
 254
 255         rc = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 256
 257         skb_free_datagram(sk, skb);
 258
 259         return rc ? : copied;
 260 }
 261
 262 static const struct proto_ops rawsock_ops = {
 263         .family         = PF_NFC,
 264         .owner          = THIS_MODULE,
 265         .release        = rawsock_release,
 266         .bind           = sock_no_bind,
 267         .connect        = rawsock_connect,
 268         .socketpair     = sock_no_socketpair,
 269         .accept         = sock_no_accept,
 270         .getname        = sock_no_getname,
 271         .poll           = datagram_poll,
 272         .ioctl          = sock_no_ioctl,
 273         .listen         = sock_no_listen,
 274         .shutdown       = sock_no_shutdown,
 275         .setsockopt     = sock_no_setsockopt,
 276         .getsockopt     = sock_no_getsockopt,
 277         .sendmsg        = rawsock_sendmsg,
 278         .recvmsg        = rawsock_recvmsg,
 279         .mmap           = sock_no_mmap,
 280 };
 281
 282 static void rawsock_destruct(struct sock *sk)
 283 {
 284         pr_debug("sk=%p\n", sk);
 285
 286         if (sk->sk_state == TCP_ESTABLISHED) {
 287                 nfc_deactivate_target(nfc_rawsock(sk)->dev,
 288                                       nfc_rawsock(sk)->target_idx);
 289                 nfc_put_device(nfc_rawsock(sk)->dev);
 290         }
 291
 292         skb_queue_purge(&sk->sk_receive_queue);
 293
 294         if (!sock_flag(sk, SOCK_DEAD)) {
 295                 pr_err("Freeing alive NFC raw socket %p\n", sk);
 296                 return;
 297         }
 298 }
 299
 300 static int rawsock_create(struct net *net, struct socket *sock,
 301                           const struct nfc_protocol *nfc_proto)
 302 {
 303         struct sock *sk;
 304
 305         pr_debug("sock=%p\n", sock);
 306
 307         if (sock->type != SOCK_SEQPACKET)
 308                 return -ESOCKTNOSUPPORT;
 309
 310         sock->ops = &rawsock_ops;
 311
 312         sk = sk_alloc(net, PF_NFC, GFP_ATOMIC, nfc_proto->proto);
 313         if (!sk)
 314                 return -ENOMEM;
 315
 316         sock_init_data(sock, sk);
 317         sk->sk_protocol = nfc_proto->id;
 318         sk->sk_destruct = rawsock_destruct;
 319         sock->state = SS_UNCONNECTED;
 320
 321         INIT_WORK(&nfc_rawsock(sk)->tx_work, rawsock_tx_work);
 322         nfc_rawsock(sk)->tx_work_scheduled = false;
 323
 324         return 0;
 325 }
 326
 327 static struct proto rawsock_proto = {
 328         .name     = "NFC_RAW",
 329         .owner    = THIS_MODULE,
 330         .obj_size = sizeof(struct nfc_rawsock),
 331 };
 332
 333 static const struct nfc_protocol rawsock_nfc_proto = {
 334         .id       = NFC_SOCKPROTO_RAW,
 335         .proto    = &rawsock_proto,
 336         .owner    = THIS_MODULE,
 337         .create   = rawsock_create
 338 };
 339
 340 int __init rawsock_init(void)
 341 {
 342         int rc;
 343
 344         rc = nfc_proto_register(&rawsock_nfc_proto);
 345
 346         return rc;
 347 }
 348
 349 void rawsock_exit(void)
 350 {
 351         nfc_proto_unregister(&rawsock_nfc_proto);
 352 }