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 <net/sock.h>
  39
  40 #include <linux/isdn/capilli.h>
  41
  42 #include <net/bluetooth/bluetooth.h>
  43 #include <net/bluetooth/l2cap.h>
  44
  45 #include "cmtp.h"
  46
  47 #ifndef CONFIG_BT_CMTP_DEBUG
  48 #undef  BT_DBG
  49 #define BT_DBG(D...)
  50 #endif
  51
  52 #define VERSION "1.0"
  53
  54 static DECLARE_RWSEM(cmtp_session_sem);
  55 static LIST_HEAD(cmtp_session_list);
  56
  57 static struct cmtp_session *__cmtp_get_session(bdaddr_t *bdaddr)
  58 {
  59         struct cmtp_session *session;
  60         struct list_head *p;
  61
  62         BT_DBG("");
  63
  64         list_for_each(p, &cmtp_session_list) {
  65                 session = list_entry(p, struct cmtp_session, list);
  66                 if (!bacmp(bdaddr, &session->bdaddr))
  67                         return session;
  68         }
  69         return NULL;
  70 }
  71
  72 static void __cmtp_link_session(struct cmtp_session *session)
  73 {
  74         __module_get(THIS_MODULE);
  75         list_add(&session->list, &cmtp_session_list);
  76 }
  77
  78 static void __cmtp_unlink_session(struct cmtp_session *session)
  79 {
  80         list_del(&session->list);
  81         module_put(THIS_MODULE);
  82 }
  83
  84 static void __cmtp_copy_session(struct cmtp_session *session, struct cmtp_conninfo *ci)
  85 {
  86         bacpy(&ci->bdaddr, &session->bdaddr);
  87
  88         ci->flags = session->flags;
  89         ci->state = session->state;
  90
  91         ci->num = session->num;
  92 }
  93
  94
  95 static inline int cmtp_alloc_block_id(struct cmtp_session *session)
  96 {
  97         int i, id = -1;
  98
  99         for (i = 0; i < 16; i++)
 100                 if (!test_and_set_bit(i, &session->blockids)) {
 101                         id = i;
 102                         break;
 103                 }
 104
 105         return id;
 106 }
 107
 108 static inline void cmtp_free_block_id(struct cmtp_session *session, int id)
 109 {
 110         clear_bit(id, &session->blockids);
 111 }
 112
 113 static inline void cmtp_add_msgpart(struct cmtp_session *session, int id, const unsigned char *buf, int count)
 114 {
 115         struct sk_buff *skb = session->reassembly[id], *nskb;
 116         int size;
 117
 118         BT_DBG("session %p buf %p count %d", session, buf, count);
 119
 120         size = (skb) ? skb->len + count : count;
 121
 122         if (!(nskb = alloc_skb(size, GFP_ATOMIC))) {
 123                 BT_ERR("Can't allocate memory for CAPI message");
 124                 return;
 125         }
 126
 127         if (skb && (skb->len > 0))
 128                 skb_copy_from_linear_data(skb, skb_put(nskb, skb->len), skb->len);
 129
 130         memcpy(skb_put(nskb, count), buf, count);
 131
 132         session->reassembly[id] = nskb;
 133
 134         if (skb)
 135                 kfree_skb(skb);
 136 }
 137
 138 static inline int cmtp_recv_frame(struct cmtp_session *session, struct sk_buff *skb)
 139 {
 140         __u8 hdr, hdrlen, id;
 141         __u16 len;
 142
 143         BT_DBG("session %p skb %p len %d", session, skb, skb->len);
 144
 145         while (skb->len > 0) {
 146                 hdr = skb->data[0];
 147
 148                 switch (hdr & 0xc0) {
 149                 case 0x40:
 150                         hdrlen = 2;
 151                         len = skb->data[1];
 152                         break;
 153                 case 0x80:
 154                         hdrlen = 3;
 155                         len = skb->data[1] | (skb->data[2] << 8);
 156                         break;
 157                 default:
 158                         hdrlen = 1;
 159                         len = 0;
 160                         break;
 161                 }
 162
 163                 id = (hdr & 0x3c) >> 2;
 164
 165                 BT_DBG("hdr 0x%02x hdrlen %d len %d id %d", hdr, hdrlen, len, id);
 166
 167                 if (hdrlen + len > skb->len) {
 168                         BT_ERR("Wrong size or header information in CMTP frame");
 169                         break;
 170                 }
 171
 172                 if (len == 0) {
 173                         skb_pull(skb, hdrlen);
 174                         continue;
 175                 }
 176
 177                 switch (hdr & 0x03) {
 178                 case 0x00:
 179                         cmtp_add_msgpart(session, id, skb->data + hdrlen, len);
 180                         cmtp_recv_capimsg(session, session->reassembly[id]);
 181                         session->reassembly[id] = NULL;
 182                         break;
 183                 case 0x01:
 184                         cmtp_add_msgpart(session, id, skb->data + hdrlen, len);
 185                         break;
 186                 default:
 187                         if (session->reassembly[id] != NULL)
 188                                 kfree_skb(session->reassembly[id]);
 189                         session->reassembly[id] = NULL;
 190                         break;
 191                 }
 192
 193                 skb_pull(skb, hdrlen + len);
 194         }
 195
 196         kfree_skb(skb);
 197         return 0;
 198 }
 199
 200 static int cmtp_send_frame(struct cmtp_session *session, unsigned char *data, int len)
 201 {
 202         struct socket *sock = session->sock;
 203         struct kvec iv = { data, len };
 204         struct msghdr msg;
 205
 206         BT_DBG("session %p data %p len %d", session, data, len);
 207
 208         if (!len)
 209                 return 0;
 210
 211         memset(&msg, 0, sizeof(msg));
 212
 213         return kernel_sendmsg(sock, &msg, &iv, 1, len);
 214 }
 215
 216 static void cmtp_process_transmit(struct cmtp_session *session)
 217 {
 218         struct sk_buff *skb, *nskb;
 219         unsigned char *hdr;
 220         unsigned int size, tail;
 221
 222         BT_DBG("session %p", session);
 223
 224         if (!(nskb = alloc_skb(session->mtu, GFP_ATOMIC))) {
 225                 BT_ERR("Can't allocate memory for new frame");
 226                 return;
 227         }
 228
 229         while ((skb = skb_dequeue(&session->transmit))) {
 230                 struct cmtp_scb *scb = (void *) skb->cb;
 231
 232                 if ((tail = (session->mtu - nskb->len)) < 5) {
 233                         cmtp_send_frame(session, nskb->data, nskb->len);
 234                         skb_trim(nskb, 0);
 235                         tail = session->mtu;
 236                 }
 237
 238                 size = min_t(uint, ((tail < 258) ? (tail - 2) : (tail - 3)), skb->len);
 239
 240                 if ((scb->id < 0) && ((scb->id = cmtp_alloc_block_id(session)) < 0)) {
 241                         skb_queue_head(&session->transmit, skb);
 242                         break;
 243                 }
 244
 245                 if (size < 256) {
 246                         hdr = skb_put(nskb, 2);
 247                         hdr[0] = 0x40
 248                                 | ((scb->id << 2) & 0x3c)
 249                                 | ((skb->len == size) ? 0x00 : 0x01);
 250                         hdr[1] = size;
 251                 } else {
 252                         hdr = skb_put(nskb, 3);
 253                         hdr[0] = 0x80
 254                                 | ((scb->id << 2) & 0x3c)
 255                                 | ((skb->len == size) ? 0x00 : 0x01);
 256                         hdr[1] = size & 0xff;
 257                         hdr[2] = size >> 8;
 258                 }
 259
 260                 skb_copy_from_linear_data(skb, skb_put(nskb, size), size);
 261                 skb_pull(skb, size);
 262
 263                 if (skb->len > 0) {
 264                         skb_queue_head(&session->transmit, skb);
 265                 } else {
 266                         cmtp_free_block_id(session, scb->id);
 267                         if (scb->data) {
 268                                 cmtp_send_frame(session, nskb->data, nskb->len);
 269                                 skb_trim(nskb, 0);
 270                         }
 271                         kfree_skb(skb);
 272                 }
 273         }
 274
 275         cmtp_send_frame(session, nskb->data, nskb->len);
 276
 277         kfree_skb(nskb);
 278 }
 279
 280 static int cmtp_session(void *arg)
 281 {
 282         struct cmtp_session *session = arg;
 283         struct sock *sk = session->sock->sk;
 284         struct sk_buff *skb;
 285         wait_queue_t wait;
 286
 287         BT_DBG("session %p", session);
 288
 289         daemonize("kcmtpd_ctr_%d", session->num);
 290         set_user_nice(current, -15);
 291
 292         init_waitqueue_entry(&wait, current);
 293         add_wait_queue(sk->sk_sleep, &wait);
 294         while (!atomic_read(&session->terminate)) {
 295                 set_current_state(TASK_INTERRUPTIBLE);
 296
 297                 if (sk->sk_state != BT_CONNECTED)
 298                         break;
 299
 300                 while ((skb = skb_dequeue(&sk->sk_receive_queue))) {
 301                         skb_orphan(skb);
 302                         cmtp_recv_frame(session, skb);
 303                 }
 304
 305                 cmtp_process_transmit(session);
 306
 307                 schedule();
 308         }
 309         set_current_state(TASK_RUNNING);
 310         remove_wait_queue(sk->sk_sleep, &wait);
 311
 312         down_write(&cmtp_session_sem);
 313
 314         if (!(session->flags & (1 << CMTP_LOOPBACK)))
 315                 cmtp_detach_device(session);
 316
 317         fput(session->sock->file);
 318
 319         __cmtp_unlink_session(session);
 320
 321         up_write(&cmtp_session_sem);
 322
 323         kfree(session);
 324         return 0;
 325 }
 326
 327 int cmtp_add_connection(struct cmtp_connadd_req *req, struct socket *sock)
 328 {
 329         struct cmtp_session *session, *s;
 330         bdaddr_t src, dst;
 331         int i, err;
 332
 333         BT_DBG("");
 334
 335         baswap(&src, &bt_sk(sock->sk)->src);
 336         baswap(&dst, &bt_sk(sock->sk)->dst);
 337
 338         session = kzalloc(sizeof(struct cmtp_session), GFP_KERNEL);
 339         if (!session)
 340                 return -ENOMEM;
 341
 342         down_write(&cmtp_session_sem);
 343
 344         s = __cmtp_get_session(&bt_sk(sock->sk)->dst);
 345         if (s && s->state == BT_CONNECTED) {
 346                 err = -EEXIST;
 347                 goto failed;
 348         }
 349
 350         bacpy(&session->bdaddr, &bt_sk(sock->sk)->dst);
 351
 352         session->mtu = min_t(uint, l2cap_pi(sock->sk)->omtu, l2cap_pi(sock->sk)->imtu);
 353
 354         BT_DBG("mtu %d", session->mtu);
 355
 356         sprintf(session->name, "%s", batostr(&dst));
 357
 358         session->sock  = sock;
 359         session->state = BT_CONFIG;
 360
 361         init_waitqueue_head(&session->wait);
 362
 363         session->msgnum = CMTP_INITIAL_MSGNUM;
 364
 365         INIT_LIST_HEAD(&session->applications);
 366
 367         skb_queue_head_init(&session->transmit);
 368
 369         for (i = 0; i < 16; i++)
 370                 session->reassembly[i] = NULL;
 371
 372         session->flags = req->flags;
 373
 374         __cmtp_link_session(session);
 375
 376         err = kernel_thread(cmtp_session, session, CLONE_KERNEL);
 377         if (err < 0)
 378                 goto unlink;
 379
 380         if (!(session->flags & (1 << CMTP_LOOPBACK))) {
 381                 err = cmtp_attach_device(session);
 382                 if (err < 0)
 383                         goto detach;
 384         }
 385
 386         up_write(&cmtp_session_sem);
 387         return 0;
 388
 389 detach:
 390         cmtp_detach_device(session);
 391
 392 unlink:
 393         __cmtp_unlink_session(session);
 394
 395 failed:
 396         up_write(&cmtp_session_sem);
 397         kfree(session);
 398         return err;
 399 }
 400
 401 int cmtp_del_connection(struct cmtp_conndel_req *req)
 402 {
 403         struct cmtp_session *session;
 404         int err = 0;
 405
 406         BT_DBG("");
 407
 408         down_read(&cmtp_session_sem);
 409
 410         session = __cmtp_get_session(&req->bdaddr);
 411         if (session) {
 412                 /* Flush the transmit queue */
 413                 skb_queue_purge(&session->transmit);
 414
 415                 /* Kill session thread */
 416                 atomic_inc(&session->terminate);
 417                 cmtp_schedule(session);
 418         } else
 419                 err = -ENOENT;
 420
 421         up_read(&cmtp_session_sem);
 422         return err;
 423 }
 424
 425 int cmtp_get_connlist(struct cmtp_connlist_req *req)
 426 {
 427         struct list_head *p;
 428         int err = 0, n = 0;
 429
 430         BT_DBG("");
 431
 432         down_read(&cmtp_session_sem);
 433
 434         list_for_each(p, &cmtp_session_list) {
 435                 struct cmtp_session *session;
 436                 struct cmtp_conninfo ci;
 437
 438                 session = list_entry(p, struct cmtp_session, list);
 439
 440                 __cmtp_copy_session(session, &ci);
 441
 442                 if (copy_to_user(req->ci, &ci, sizeof(ci))) {
 443                         err = -EFAULT;
 444                         break;
 445                 }
 446
 447                 if (++n >= req->cnum)
 448                         break;
 449
 450                 req->ci++;
 451         }
 452         req->cnum = n;
 453
 454         up_read(&cmtp_session_sem);
 455         return err;
 456 }
 457
 458 int cmtp_get_conninfo(struct cmtp_conninfo *ci)
 459 {
 460         struct cmtp_session *session;
 461         int err = 0;
 462
 463         down_read(&cmtp_session_sem);
 464
 465         session = __cmtp_get_session(&ci->bdaddr);
 466         if (session)
 467                 __cmtp_copy_session(session, ci);
 468         else
 469                 err = -ENOENT;
 470
 471         up_read(&cmtp_session_sem);
 472         return err;
 473 }
 474
 475
 476 static int __init cmtp_init(void)
 477 {
 478         l2cap_load();
 479
 480         BT_INFO("CMTP (CAPI Emulation) ver %s", VERSION);
 481
 482         cmtp_init_sockets();
 483
 484         return 0;
 485 }
 486
 487 static void __exit cmtp_exit(void)
 488 {
 489         cmtp_cleanup_sockets();
 490 }
 491
 492 module_init(cmtp_init);
 493 module_exit(cmtp_exit);
 494
 495 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
 496 MODULE_DESCRIPTION("Bluetooth CMTP ver " VERSION);
 497 MODULE_VERSION(VERSION);
 498 MODULE_LICENSE("GPL");
 499 MODULE_ALIAS("bt-proto-5");