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/config.h>
  24 #include <linux/module.h>
  25
  26 #include <linux/types.h>
  27 #include <linux/errno.h>
  28 #include <linux/kernel.h>
  29 #include <linux/sched.h>
  30 #include <linux/slab.h>
  31 #include <linux/poll.h>
  32 #include <linux/fcntl.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                 memcpy(skb_put(nskb, skb->len), skb->data, 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                 memcpy(skb_put(nskb, size), skb->data, 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         current->flags |= PF_NOFREEZE;
 292
 293         init_waitqueue_entry(&wait, current);
 294         add_wait_queue(sk->sk_sleep, &wait);
 295         while (!atomic_read(&session->terminate)) {
 296                 set_current_state(TASK_INTERRUPTIBLE);
 297
 298                 if (sk->sk_state != BT_CONNECTED)
 299                         break;
 300
 301                 while ((skb = skb_dequeue(&sk->sk_receive_queue))) {
 302                         skb_orphan(skb);
 303                         cmtp_recv_frame(session, skb);
 304                 }
 305
 306                 cmtp_process_transmit(session);
 307
 308                 schedule();
 309         }
 310         set_current_state(TASK_RUNNING);
 311         remove_wait_queue(sk->sk_sleep, &wait);
 312
 313         down_write(&cmtp_session_sem);
 314
 315         if (!(session->flags & (1 << CMTP_LOOPBACK)))
 316                 cmtp_detach_device(session);
 317
 318         fput(session->sock->file);
 319
 320         __cmtp_unlink_session(session);
 321
 322         up_write(&cmtp_session_sem);
 323
 324         kfree(session);
 325         return 0;
 326 }
 327
 328 int cmtp_add_connection(struct cmtp_connadd_req *req, struct socket *sock)
 329 {
 330         struct cmtp_session *session, *s;
 331         bdaddr_t src, dst;
 332         int i, err;
 333
 334         BT_DBG("");
 335
 336         baswap(&src, &bt_sk(sock->sk)->src);
 337         baswap(&dst, &bt_sk(sock->sk)->dst);
 338
 339         session = kmalloc(sizeof(struct cmtp_session), GFP_KERNEL);
 340         if (!session)
 341                 return -ENOMEM;
 342         memset(session, 0, sizeof(struct cmtp_session));
 343
 344         down_write(&cmtp_session_sem);
 345
 346         s = __cmtp_get_session(&bt_sk(sock->sk)->dst);
 347         if (s && s->state == BT_CONNECTED) {
 348                 err = -EEXIST;
 349                 goto failed;
 350         }
 351
 352         bacpy(&session->bdaddr, &bt_sk(sock->sk)->dst);
 353
 354         session->mtu = min_t(uint, l2cap_pi(sock->sk)->omtu, l2cap_pi(sock->sk)->imtu);
 355
 356         BT_DBG("mtu %d", session->mtu);
 357
 358         sprintf(session->name, "%s", batostr(&dst));
 359
 360         session->sock  = sock;
 361         session->state = BT_CONFIG;
 362
 363         init_waitqueue_head(&session->wait);
 364
 365         session->msgnum = CMTP_INITIAL_MSGNUM;
 366
 367         INIT_LIST_HEAD(&session->applications);
 368
 369         skb_queue_head_init(&session->transmit);
 370
 371         for (i = 0; i < 16; i++)
 372                 session->reassembly[i] = NULL;
 373
 374         session->flags = req->flags;
 375
 376         __cmtp_link_session(session);
 377
 378         err = kernel_thread(cmtp_session, session, CLONE_KERNEL);
 379         if (err < 0)
 380                 goto unlink;
 381
 382         if (!(session->flags & (1 << CMTP_LOOPBACK))) {
 383                 err = cmtp_attach_device(session);
 384                 if (err < 0)
 385                         goto detach;
 386         }
 387
 388         up_write(&cmtp_session_sem);
 389         return 0;
 390
 391 detach:
 392         cmtp_detach_device(session);
 393
 394 unlink:
 395         __cmtp_unlink_session(session);
 396
 397 failed:
 398         up_write(&cmtp_session_sem);
 399         kfree(session);
 400         return err;
 401 }
 402
 403 int cmtp_del_connection(struct cmtp_conndel_req *req)
 404 {
 405         struct cmtp_session *session;
 406         int err = 0;
 407
 408         BT_DBG("");
 409
 410         down_read(&cmtp_session_sem);
 411
 412         session = __cmtp_get_session(&req->bdaddr);
 413         if (session) {
 414                 /* Flush the transmit queue */
 415                 skb_queue_purge(&session->transmit);
 416
 417                 /* Kill session thread */
 418                 atomic_inc(&session->terminate);
 419                 cmtp_schedule(session);
 420         } else
 421                 err = -ENOENT;
 422
 423         up_read(&cmtp_session_sem);
 424         return err;
 425 }
 426
 427 int cmtp_get_connlist(struct cmtp_connlist_req *req)
 428 {
 429         struct list_head *p;
 430         int err = 0, n = 0;
 431
 432         BT_DBG("");
 433
 434         down_read(&cmtp_session_sem);
 435
 436         list_for_each(p, &cmtp_session_list) {
 437                 struct cmtp_session *session;
 438                 struct cmtp_conninfo ci;
 439
 440                 session = list_entry(p, struct cmtp_session, list);
 441
 442                 __cmtp_copy_session(session, &ci);
 443
 444                 if (copy_to_user(req->ci, &ci, sizeof(ci))) {
 445                         err = -EFAULT;
 446                         break;
 447                 }
 448
 449                 if (++n >= req->cnum)
 450                         break;
 451
 452                 req->ci++;
 453         }
 454         req->cnum = n;
 455
 456         up_read(&cmtp_session_sem);
 457         return err;
 458 }
 459
 460 int cmtp_get_conninfo(struct cmtp_conninfo *ci)
 461 {
 462         struct cmtp_session *session;
 463         int err = 0;
 464
 465         down_read(&cmtp_session_sem);
 466
 467         session = __cmtp_get_session(&ci->bdaddr);
 468         if (session)
 469                 __cmtp_copy_session(session, ci);
 470         else
 471                 err = -ENOENT;
 472
 473         up_read(&cmtp_session_sem);
 474         return err;
 475 }
 476
 477
 478 static int __init cmtp_init(void)
 479 {
 480         l2cap_load();
 481
 482         BT_INFO("CMTP (CAPI Emulation) ver %s", VERSION);
 483
 484         cmtp_init_sockets();
 485
 486         return 0;
 487 }
 488
 489 static void __exit cmtp_exit(void)
 490 {
 491         cmtp_cleanup_sockets();
 492 }
 493
 494 module_init(cmtp_init);
 495 module_exit(cmtp_exit);
 496
 497 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
 498 MODULE_DESCRIPTION("Bluetooth CMTP ver " VERSION);
 499 MODULE_VERSION(VERSION);
 500 MODULE_LICENSE("GPL");
 501 MODULE_ALIAS("bt-proto-5");