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