net/bluetooth/cmtp/core.c

   1 /*
   2    CMTP implementation for Linux Bluetooth stack (BlueZ).
   3    Copyright (C) 2002-2003 Marcel Holtmann <marcel@holtmann.org>
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License version 2 as
   7    published by the Free Software Foundation;
   8
   9    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  10    OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  11    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
  12    IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
  13    CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
  14    WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15    ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17
  18    ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
  19    COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
  20    SOFTWARE IS DISCLAIMED.
  21 */
  22
  23 #include <linux/module.h>
  24
  25 #include <linux/types.h>
  26 #include <linux/errno.h>
  27 #include <linux/kernel.h>
  28 #include <linux/sched.h>
  29 #include <linux/slab.h>
  30 #include <linux/poll.h>
  31 #include <linux/fcntl.h>
  32 #include <linux/freezer.h>
  33 #include <linux/skbuff.h>
  34 #include <linux/socket.h>
  35 #include <linux/ioctl.h>
  36 #include <linux/file.h>
  37 #include <linux/init.h>
  38 #include <linux/kthread.h>
  39 #include <net/sock.h>
  40
  41 #include <linux/isdn/capilli.h>
  42
  43 #include <net/bluetooth/bluetooth.h>
  44 #include <net/bluetooth/l2cap.h>
  45
  46 #include "cmtp.h"
  47
  48 #define VERSION "1.0"
  49
  50 static DECLARE_RWSEM(cmtp_session_sem);
  51 static LIST_HEAD(cmtp_session_list);
  52
  53 static struct cmtp_session *__cmtp_get_session(bdaddr_t *bdaddr)
  54 {
  55         struct cmtp_session *session;
  56
  57         BT_DBG("");
  58
  59         list_for_each_entry(session, &cmtp_session_list, list)
  60                 if (!bacmp(bdaddr, &session->bdaddr))
  61                         return session;
  62
  63         return NULL;
  64 }
  65
  66 static void __cmtp_link_session(struct cmtp_session *session)
  67 {
  68         list_add(&session->list, &cmtp_session_list);
  69 }
  70
  71 static void __cmtp_unlink_session(struct cmtp_session *session)
  72 {
  73         list_del(&session->list);
  74 }
  75
  76 static void __cmtp_copy_session(struct cmtp_session *session, struct cmtp_conninfo *ci)
  77 {
  78         u32 valid_flags = BIT(CMTP_LOOPBACK);
  79         memset(ci, 0, sizeof(*ci));
  80         bacpy(&ci->bdaddr, &session->bdaddr);
  81
  82         ci->flags = session->flags & valid_flags;
  83         ci->state = session->state;
  84
  85         ci->num = session->num;
  86 }
  87
  88
  89 static inline int cmtp_alloc_block_id(struct cmtp_session *session)
  90 {
  91         int i, id = -1;
  92
  93         for (i = 0; i < 16; i++)
  94                 if (!test_and_set_bit(i, &session->blockids)) {
  95                         id = i;
  96                         break;
  97                 }
  98
  99         return id;
 100 }
 101
 102 static inline void cmtp_free_block_id(struct cmtp_session *session, int id)
 103 {
 104         clear_bit(id, &session->blockids);
 105 }
 106
 107 static inline void cmtp_add_msgpart(struct cmtp_session *session, int id, const unsigned char *buf, int count)
 108 {
 109         struct sk_buff *skb = session->reassembly[id], *nskb;
 110         int size;
 111
 112         BT_DBG("session %p buf %p count %d", session, buf, count);
 113
 114         size = (skb) ? skb->len + count : count;
 115
 116         nskb = alloc_skb(size, GFP_ATOMIC);
 117         if (!nskb) {
 118                 BT_ERR("Can't allocate memory for CAPI message");
 119                 return;
 120         }
 121
 122         if (skb && (skb->len > 0))
 123                 skb_copy_from_linear_data(skb, skb_put(nskb, skb->len), skb->len);
 124
 125         skb_put_data(nskb, buf, count);
 126
 127         session->reassembly[id] = nskb;
 128
 129         kfree_skb(skb);
 130 }
 131
 132 static inline int cmtp_recv_frame(struct cmtp_session *session, struct sk_buff *skb)
 133 {
 134         __u8 hdr, hdrlen, id;
 135         __u16 len;
 136
 137         BT_DBG("session %p skb %p len %d", session, skb, skb->len);
 138
 139         while (skb->len > 0) {
 140                 hdr = skb->data[0];
 141
 142                 switch (hdr & 0xc0) {
 143                 case 0x40:
 144                         hdrlen = 2;
 145                         len = skb->data[1];
 146                         break;
 147                 case 0x80:
 148                         hdrlen = 3;
 149                         len = skb->data[1] | (skb->data[2] << 8);
 150                         break;
 151                 default:
 152                         hdrlen = 1;
 153                         len = 0;
 154                         break;
 155                 }
 156
 157                 id = (hdr & 0x3c) >> 2;
 158
 159                 BT_DBG("hdr 0x%02x hdrlen %d len %d id %d", hdr, hdrlen, len, id);
 160
 161                 if (hdrlen + len > skb->len) {
 162                         BT_ERR("Wrong size or header information in CMTP frame");
 163                         break;
 164                 }
 165
 166                 if (len == 0) {
 167                         skb_pull(skb, hdrlen);
 168                         continue;
 169                 }
 170
 171                 switch (hdr & 0x03) {
 172                 case 0x00:
 173                         cmtp_add_msgpart(session, id, skb->data + hdrlen, len);
 174                         cmtp_recv_capimsg(session, session->reassembly[id]);
 175                         session->reassembly[id] = NULL;
 176                         break;
 177                 case 0x01:
 178                         cmtp_add_msgpart(session, id, skb->data + hdrlen, len);
 179                         break;
 180                 default:
 181                         kfree_skb(session->reassembly[id]);
 182                         session->reassembly[id] = NULL;
 183                         break;
 184                 }
 185
 186                 skb_pull(skb, hdrlen + len);
 187         }
 188
 189         kfree_skb(skb);
 190         return 0;
 191 }
 192
 193 static int cmtp_send_frame(struct cmtp_session *session, unsigned char *data, int len)
 194 {
 195         struct socket *sock = session->sock;
 196         struct kvec iv = { data, len };
 197         struct msghdr msg;
 198
 199         BT_DBG("session %p data %p len %d", session, data, len);
 200
 201         if (!len)
 202                 return 0;
 203
 204         memset(&msg, 0, sizeof(msg));
 205
 206         return kernel_sendmsg(sock, &msg, &iv, 1, len);
 207 }
 208
 209 static void cmtp_process_transmit(struct cmtp_session *session)
 210 {
 211         struct sk_buff *skb, *nskb;
 212         unsigned char *hdr;
 213         unsigned int size, tail;
 214
 215         BT_DBG("session %p", session);
 216
 217         nskb = alloc_skb(session->mtu, GFP_ATOMIC);
 218         if (!nskb) {
 219                 BT_ERR("Can't allocate memory for new frame");
 220                 return;
 221         }
 222
 223         while ((skb = skb_dequeue(&session->transmit))) {
 224                 struct cmtp_scb *scb = (void *) skb->cb;
 225
 226                 tail = session->mtu - nskb->len;
 227                 if (tail < 5) {
 228                         cmtp_send_frame(session, nskb->data, nskb->len);
 229                         skb_trim(nskb, 0);
 230                         tail = session->mtu;
 231                 }
 232
 233                 size = min_t(uint, ((tail < 258) ? (tail - 2) : (tail - 3)), skb->len);
 234
 235                 if (scb->id < 0) {
 236                         scb->id = cmtp_alloc_block_id(session);
 237                         if (scb->id < 0) {
 238                                 skb_queue_head(&session->transmit, skb);
 239                                 break;
 240                         }
 241                 }
 242
 243                 if (size < 256) {
 244                         hdr = skb_put(nskb, 2);
 245                         hdr[0] = 0x40
 246                                 | ((scb->id << 2) & 0x3c)
 247                                 | ((skb->len == size) ? 0x00 : 0x01);
 248                         hdr[1] = size;
 249                 } else {
 250                         hdr = skb_put(nskb, 3);
 251                         hdr[0] = 0x80
 252                                 | ((scb->id << 2) & 0x3c)
 253                                 | ((skb->len == size) ? 0x00 : 0x01);
 254                         hdr[1] = size & 0xff;
 255                         hdr[2] = size >> 8;
 256                 }
 257
 258                 skb_copy_from_linear_data(skb, skb_put(nskb, size), size);
 259                 skb_pull(skb, size);
 260
 261                 if (skb->len > 0) {
 262                         skb_queue_head(&session->transmit, skb);
 263                 } else {
 264                         cmtp_free_block_id(session, scb->id);
 265                         if (scb->data) {
 266                                 cmtp_send_frame(session, nskb->data, nskb->len);
 267                                 skb_trim(nskb, 0);
 268                         }
 269                         kfree_skb(skb);
 270                 }
 271         }
 272
 273         cmtp_send_frame(session, nskb->data, nskb->len);
 274
 275         kfree_skb(nskb);
 276 }
 277
 278 static int cmtp_session(void *arg)
 279 {
 280         struct cmtp_session *session = arg;
 281         struct sock *sk = session->sock->sk;
 282         struct sk_buff *skb;
 283         DEFINE_WAIT_FUNC(wait, woken_wake_function);
 284
 285         BT_DBG("session %p", session);
 286
 287         set_user_nice(current, -15);
 288
 289         add_wait_queue(sk_sleep(sk), &wait);
 290         while (1) {
 291                 if (atomic_read(&session->terminate))
 292                         break;
 293                 if (sk->sk_state != BT_CONNECTED)
 294                         break;
 295
 296                 while ((skb = skb_dequeue(&sk->sk_receive_queue))) {
 297                         skb_orphan(skb);
 298                         if (!skb_linearize(skb))
 299                                 cmtp_recv_frame(session, skb);
 300                         else
 301                                 kfree_skb(skb);
 302                 }
 303
 304                 cmtp_process_transmit(session);
 305
 306                 /*
 307                  * wait_woken() performs the necessary memory barriers
 308                  * for us; see the header comment for this primitive.
 309                  */
 310                 wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
 311         }
 312         remove_wait_queue(sk_sleep(sk), &wait);
 313
 314         down_write(&cmtp_session_sem);
 315
 316         if (!(session->flags & BIT(CMTP_LOOPBACK)))
 317                 cmtp_detach_device(session);
 318
 319         fput(session->sock->file);
 320
 321         __cmtp_unlink_session(session);
 322
 323         up_write(&cmtp_session_sem);
 324
 325         kfree(session);
 326         module_put_and_exit(0);
 327         return 0;
 328 }
 329
 330 int cmtp_add_connection(struct cmtp_connadd_req *req, struct socket *sock)
 331 {
 332         u32 valid_flags = BIT(CMTP_LOOPBACK);
 333         struct cmtp_session *session, *s;
 334         int i, err;
 335
 336         BT_DBG("");
 337
 338         if (!l2cap_is_socket(sock))
 339                 return -EBADFD;
 340
 341         if (req->flags & ~valid_flags)
 342                 return -EINVAL;
 343
 344         session = kzalloc(sizeof(struct cmtp_session), GFP_KERNEL);
 345         if (!session)
 346                 return -ENOMEM;
 347
 348         down_write(&cmtp_session_sem);
 349
 350         s = __cmtp_get_session(&l2cap_pi(sock->sk)->chan->dst);
 351         if (s && s->state == BT_CONNECTED) {
 352                 err = -EEXIST;
 353                 goto failed;
 354         }
 355
 356         bacpy(&session->bdaddr, &l2cap_pi(sock->sk)->chan->dst);
 357
 358         session->mtu = min_t(uint, l2cap_pi(sock->sk)->chan->omtu,
 359                                         l2cap_pi(sock->sk)->chan->imtu);
 360
 361         BT_DBG("mtu %d", session->mtu);
 362
 363         sprintf(session->name, "%pMR", &session->bdaddr);
 364
 365         session->sock  = sock;
 366         session->state = BT_CONFIG;
 367
 368         init_waitqueue_head(&session->wait);
 369
 370         session->msgnum = CMTP_INITIAL_MSGNUM;
 371
 372         INIT_LIST_HEAD(&session->applications);
 373
 374         skb_queue_head_init(&session->transmit);
 375
 376         for (i = 0; i < 16; i++)
 377                 session->reassembly[i] = NULL;
 378
 379         session->flags = req->flags;
 380
 381         __cmtp_link_session(session);
 382
 383         __module_get(THIS_MODULE);
 384         session->task = kthread_run(cmtp_session, session, "kcmtpd_ctr_%d",
 385                                                                 session->num);
 386         if (IS_ERR(session->task)) {
 387                 module_put(THIS_MODULE);
 388                 err = PTR_ERR(session->task);
 389                 goto unlink;
 390         }
 391
 392         if (!(session->flags & BIT(CMTP_LOOPBACK))) {
 393                 err = cmtp_attach_device(session);
 394                 if (err < 0) {
 395                         atomic_inc(&session->terminate);
 396                         wake_up_interruptible(sk_sleep(session->sock->sk));
 397                         up_write(&cmtp_session_sem);
 398                         return err;
 399                 }
 400         }
 401
 402         up_write(&cmtp_session_sem);
 403         return 0;
 404
 405 unlink:
 406         __cmtp_unlink_session(session);
 407
 408 failed:
 409         up_write(&cmtp_session_sem);
 410         kfree(session);
 411         return err;
 412 }
 413
 414 int cmtp_del_connection(struct cmtp_conndel_req *req)
 415 {
 416         u32 valid_flags = 0;
 417         struct cmtp_session *session;
 418         int err = 0;
 419
 420         BT_DBG("");
 421
 422         if (req->flags & ~valid_flags)
 423                 return -EINVAL;
 424
 425         down_read(&cmtp_session_sem);
 426
 427         session = __cmtp_get_session(&req->bdaddr);
 428         if (session) {
 429                 /* Flush the transmit queue */
 430                 skb_queue_purge(&session->transmit);
 431
 432                 /* Stop session thread */
 433                 atomic_inc(&session->terminate);
 434
 435                 /*
 436                  * See the comment preceding the call to wait_woken()
 437                  * in cmtp_session().
 438                  */
 439                 wake_up_interruptible(sk_sleep(session->sock->sk));
 440         } else
 441                 err = -ENOENT;
 442
 443         up_read(&cmtp_session_sem);
 444         return err;
 445 }
 446
 447 int cmtp_get_connlist(struct cmtp_connlist_req *req)
 448 {
 449         struct cmtp_session *session;
 450         int err = 0, n = 0;
 451
 452         BT_DBG("");
 453
 454         down_read(&cmtp_session_sem);
 455
 456         list_for_each_entry(session, &cmtp_session_list, list) {
 457                 struct cmtp_conninfo ci;
 458
 459                 __cmtp_copy_session(session, &ci);
 460
 461                 if (copy_to_user(req->ci, &ci, sizeof(ci))) {
 462                         err = -EFAULT;
 463                         break;
 464                 }
 465
 466                 if (++n >= req->cnum)
 467                         break;
 468
 469                 req->ci++;
 470         }
 471         req->cnum = n;
 472
 473         up_read(&cmtp_session_sem);
 474         return err;
 475 }
 476
 477 int cmtp_get_conninfo(struct cmtp_conninfo *ci)
 478 {
 479         struct cmtp_session *session;
 480         int err = 0;
 481
 482         down_read(&cmtp_session_sem);
 483
 484         session = __cmtp_get_session(&ci->bdaddr);
 485         if (session)
 486                 __cmtp_copy_session(session, ci);
 487         else
 488                 err = -ENOENT;
 489
 490         up_read(&cmtp_session_sem);
 491         return err;
 492 }
 493
 494
 495 static int __init cmtp_init(void)
 496 {
 497         BT_INFO("CMTP (CAPI Emulation) ver %s", VERSION);
 498
 499         cmtp_init_sockets();
 500
 501         return 0;
 502 }
 503
 504 static void __exit cmtp_exit(void)
 505 {
 506         cmtp_cleanup_sockets();
 507 }
 508
 509 module_init(cmtp_init);
 510 module_exit(cmtp_exit);
 511
 512 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
 513 MODULE_DESCRIPTION("Bluetooth CMTP ver " VERSION);
 514 MODULE_VERSION(VERSION);
 515 MODULE_LICENSE("GPL");
 516 MODULE_ALIAS("bt-proto-5");