net/caif/caif_socket.c

   1 /*
   2  * Copyright (C) ST-Ericsson AB 2010
   3  * Author:      Sjur Brendeland sjur.brandeland@stericsson.com
   4  * License terms: GNU General Public License (GPL) version 2
   5  */
   6
   7 #define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__
   8
   9 #include <linux/fs.h>
  10 #include <linux/init.h>
  11 #include <linux/module.h>
  12 #include <linux/sched.h>
  13 #include <linux/spinlock.h>
  14 #include <linux/mutex.h>
  15 #include <linux/list.h>
  16 #include <linux/wait.h>
  17 #include <linux/poll.h>
  18 #include <linux/tcp.h>
  19 #include <linux/uaccess.h>
  20 #include <linux/debugfs.h>
  21 #include <linux/caif/caif_socket.h>
  22 #include <linux/atomic.h>
  23 #include <net/sock.h>
  24 #include <net/tcp_states.h>
  25 #include <net/caif/caif_layer.h>
  26 #include <net/caif/caif_dev.h>
  27 #include <net/caif/cfpkt.h>
  28
  29 MODULE_LICENSE("GPL");
  30 MODULE_ALIAS_NETPROTO(AF_CAIF);
  31
  32 /*
  33  * CAIF state is re-using the TCP socket states.
  34  * caif_states stored in sk_state reflect the state as reported by
  35  * the CAIF stack, while sk_socket->state is the state of the socket.
  36  */
  37 enum caif_states {
  38         CAIF_CONNECTED          = TCP_ESTABLISHED,
  39         CAIF_CONNECTING = TCP_SYN_SENT,
  40         CAIF_DISCONNECTED       = TCP_CLOSE
  41 };
  42
  43 #define TX_FLOW_ON_BIT  1
  44 #define RX_FLOW_ON_BIT  2
  45
  46 static struct dentry *debugfsdir;
  47
  48 #ifdef CONFIG_DEBUG_FS
  49 struct debug_fs_counter {
  50         atomic_t caif_nr_socks;
  51         atomic_t caif_sock_create;
  52         atomic_t num_connect_req;
  53         atomic_t num_connect_resp;
  54         atomic_t num_connect_fail_resp;
  55         atomic_t num_disconnect;
  56         atomic_t num_remote_shutdown_ind;
  57         atomic_t num_tx_flow_off_ind;
  58         atomic_t num_tx_flow_on_ind;
  59         atomic_t num_rx_flow_off;
  60         atomic_t num_rx_flow_on;
  61 };
  62 static struct debug_fs_counter cnt;
  63 #define dbfs_atomic_inc(v) atomic_inc_return(v)
  64 #define dbfs_atomic_dec(v) atomic_dec_return(v)
  65 #else
  66 #define dbfs_atomic_inc(v) 0
  67 #define dbfs_atomic_dec(v) 0
  68 #endif
  69
  70 struct caifsock {
  71         struct sock sk; /* must be first member */
  72         struct cflayer layer;
  73         char name[CAIF_LAYER_NAME_SZ]; /* Used for debugging */
  74         u32 flow_state;
  75         struct caif_connect_request conn_req;
  76         struct mutex readlock;
  77         struct dentry *debugfs_socket_dir;
  78         int headroom, tailroom, maxframe;
  79 };
  80
  81 static int rx_flow_is_on(struct caifsock *cf_sk)
  82 {
  83         return test_bit(RX_FLOW_ON_BIT,
  84                         (void *) &cf_sk->flow_state);
  85 }
  86
  87 static int tx_flow_is_on(struct caifsock *cf_sk)
  88 {
  89         return test_bit(TX_FLOW_ON_BIT,
  90                         (void *) &cf_sk->flow_state);
  91 }
  92
  93 static void set_rx_flow_off(struct caifsock *cf_sk)
  94 {
  95          clear_bit(RX_FLOW_ON_BIT,
  96                  (void *) &cf_sk->flow_state);
  97 }
  98
  99 static void set_rx_flow_on(struct caifsock *cf_sk)
 100 {
 101          set_bit(RX_FLOW_ON_BIT,
 102                         (void *) &cf_sk->flow_state);
 103 }
 104
 105 static void set_tx_flow_off(struct caifsock *cf_sk)
 106 {
 107          clear_bit(TX_FLOW_ON_BIT,
 108                 (void *) &cf_sk->flow_state);
 109 }
 110
 111 static void set_tx_flow_on(struct caifsock *cf_sk)
 112 {
 113          set_bit(TX_FLOW_ON_BIT,
 114                 (void *) &cf_sk->flow_state);
 115 }
 116
 117 static void caif_read_lock(struct sock *sk)
 118 {
 119         struct caifsock *cf_sk;
 120         cf_sk = container_of(sk, struct caifsock, sk);
 121         mutex_lock(&cf_sk->readlock);
 122 }
 123
 124 static void caif_read_unlock(struct sock *sk)
 125 {
 126         struct caifsock *cf_sk;
 127         cf_sk = container_of(sk, struct caifsock, sk);
 128         mutex_unlock(&cf_sk->readlock);
 129 }
 130
 131 static int sk_rcvbuf_lowwater(struct caifsock *cf_sk)
 132 {
 133         /* A quarter of full buffer is used a low water mark */
 134         return cf_sk->sk.sk_rcvbuf / 4;
 135 }
 136
 137 static void caif_flow_ctrl(struct sock *sk, int mode)
 138 {
 139         struct caifsock *cf_sk;
 140         cf_sk = container_of(sk, struct caifsock, sk);
 141         if (cf_sk->layer.dn && cf_sk->layer.dn->modemcmd)
 142                 cf_sk->layer.dn->modemcmd(cf_sk->layer.dn, mode);
 143 }
 144
 145 /*
 146  * Copied from sock.c:sock_queue_rcv_skb(), but changed so packets are
 147  * not dropped, but CAIF is sending flow off instead.
 148  */
 149 static int caif_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 150 {
 151         int err;
 152         int skb_len;
 153         unsigned long flags;
 154         struct sk_buff_head *list = &sk->sk_receive_queue;
 155         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
 156
 157         if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
 158                 (unsigned)sk->sk_rcvbuf && rx_flow_is_on(cf_sk)) {
 159                 if (net_ratelimit())
 160                         pr_debug("sending flow OFF (queue len = %d %d)\n",
 161                                         atomic_read(&cf_sk->sk.sk_rmem_alloc),
 162                                         sk_rcvbuf_lowwater(cf_sk));
 163                 set_rx_flow_off(cf_sk);
 164                 dbfs_atomic_inc(&cnt.num_rx_flow_off);
 165                 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
 166         }
 167
 168         err = sk_filter(sk, skb);
 169         if (err)
 170                 return err;
 171         if (!sk_rmem_schedule(sk, skb->truesize) && rx_flow_is_on(cf_sk)) {
 172                 set_rx_flow_off(cf_sk);
 173                 if (net_ratelimit())
 174                         pr_debug("sending flow OFF due to rmem_schedule\n");
 175                 dbfs_atomic_inc(&cnt.num_rx_flow_off);
 176                 caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_OFF_REQ);
 177         }
 178         skb->dev = NULL;
 179         skb_set_owner_r(skb, sk);
 180         /* Cache the SKB length before we tack it onto the receive
 181          * queue. Once it is added it no longer belongs to us and
 182          * may be freed by other threads of control pulling packets
 183          * from the queue.
 184          */
 185         skb_len = skb->len;
 186         spin_lock_irqsave(&list->lock, flags);
 187         if (!sock_flag(sk, SOCK_DEAD))
 188                 __skb_queue_tail(list, skb);
 189         spin_unlock_irqrestore(&list->lock, flags);
 190
 191         if (!sock_flag(sk, SOCK_DEAD))
 192                 sk->sk_data_ready(sk, skb_len);
 193         else
 194                 kfree_skb(skb);
 195         return 0;
 196 }
 197
 198 /* Packet Receive Callback function called from CAIF Stack */
 199 static int caif_sktrecv_cb(struct cflayer *layr, struct cfpkt *pkt)
 200 {
 201         struct caifsock *cf_sk;
 202         struct sk_buff *skb;
 203
 204         cf_sk = container_of(layr, struct caifsock, layer);
 205         skb = cfpkt_tonative(pkt);
 206
 207         if (unlikely(cf_sk->sk.sk_state != CAIF_CONNECTED)) {
 208                 kfree_skb(skb);
 209                 return 0;
 210         }
 211         caif_queue_rcv_skb(&cf_sk->sk, skb);
 212         return 0;
 213 }
 214
 215 static void cfsk_hold(struct cflayer *layr)
 216 {
 217         struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
 218         sock_hold(&cf_sk->sk);
 219 }
 220
 221 static void cfsk_put(struct cflayer *layr)
 222 {
 223         struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
 224         sock_put(&cf_sk->sk);
 225 }
 226
 227 /* Packet Control Callback function called from CAIF */
 228 static void caif_ctrl_cb(struct cflayer *layr,
 229                                 enum caif_ctrlcmd flow,
 230                                 int phyid)
 231 {
 232         struct caifsock *cf_sk = container_of(layr, struct caifsock, layer);
 233         switch (flow) {
 234         case CAIF_CTRLCMD_FLOW_ON_IND:
 235                 /* OK from modem to start sending again */
 236                 dbfs_atomic_inc(&cnt.num_tx_flow_on_ind);
 237                 set_tx_flow_on(cf_sk);
 238                 cf_sk->sk.sk_state_change(&cf_sk->sk);
 239                 break;
 240
 241         case CAIF_CTRLCMD_FLOW_OFF_IND:
 242                 /* Modem asks us to shut up */
 243                 dbfs_atomic_inc(&cnt.num_tx_flow_off_ind);
 244                 set_tx_flow_off(cf_sk);
 245                 cf_sk->sk.sk_state_change(&cf_sk->sk);
 246                 break;
 247
 248         case CAIF_CTRLCMD_INIT_RSP:
 249                 /* We're now connected */
 250                 caif_client_register_refcnt(&cf_sk->layer,
 251                                                 cfsk_hold, cfsk_put);
 252                 dbfs_atomic_inc(&cnt.num_connect_resp);
 253                 cf_sk->sk.sk_state = CAIF_CONNECTED;
 254                 set_tx_flow_on(cf_sk);
 255                 cf_sk->sk.sk_state_change(&cf_sk->sk);
 256                 break;
 257
 258         case CAIF_CTRLCMD_DEINIT_RSP:
 259                 /* We're now disconnected */
 260                 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
 261                 cf_sk->sk.sk_state_change(&cf_sk->sk);
 262                 break;
 263
 264         case CAIF_CTRLCMD_INIT_FAIL_RSP:
 265                 /* Connect request failed */
 266                 dbfs_atomic_inc(&cnt.num_connect_fail_resp);
 267                 cf_sk->sk.sk_err = ECONNREFUSED;
 268                 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
 269                 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
 270                 /*
 271                  * Socket "standards" seems to require POLLOUT to
 272                  * be set at connect failure.
 273                  */
 274                 set_tx_flow_on(cf_sk);
 275                 cf_sk->sk.sk_state_change(&cf_sk->sk);
 276                 break;
 277
 278         case CAIF_CTRLCMD_REMOTE_SHUTDOWN_IND:
 279                 /* Modem has closed this connection, or device is down. */
 280                 dbfs_atomic_inc(&cnt.num_remote_shutdown_ind);
 281                 cf_sk->sk.sk_shutdown = SHUTDOWN_MASK;
 282                 cf_sk->sk.sk_err = ECONNRESET;
 283                 set_rx_flow_on(cf_sk);
 284                 cf_sk->sk.sk_error_report(&cf_sk->sk);
 285                 break;
 286
 287         default:
 288                 pr_debug("Unexpected flow command %d\n", flow);
 289         }
 290 }
 291
 292 static void caif_check_flow_release(struct sock *sk)
 293 {
 294         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
 295
 296         if (rx_flow_is_on(cf_sk))
 297                 return;
 298
 299         if (atomic_read(&sk->sk_rmem_alloc) <= sk_rcvbuf_lowwater(cf_sk)) {
 300                         dbfs_atomic_inc(&cnt.num_rx_flow_on);
 301                         set_rx_flow_on(cf_sk);
 302                         caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_ON_REQ);
 303         }
 304 }
 305
 306 /*
 307  * Copied from unix_dgram_recvmsg, but removed credit checks,
 308  * changed locking, address handling and added MSG_TRUNC.
 309  */
 310 static int caif_seqpkt_recvmsg(struct kiocb *iocb, struct socket *sock,
 311                                 struct msghdr *m, size_t len, int flags)
 312
 313 {
 314         struct sock *sk = sock->sk;
 315         struct sk_buff *skb;
 316         int ret;
 317         int copylen;
 318
 319         ret = -EOPNOTSUPP;
 320         if (flags & MSG_OOB)
 321                 goto read_error;
 322
 323         skb = skb_recv_datagram(sk, flags, 0 , &ret);
 324         if (!skb)
 325                 goto read_error;
 326         copylen = skb->len;
 327         if (len < copylen) {
 328                 m->msg_flags |= MSG_TRUNC;
 329                 copylen = len;
 330         }
 331
 332         ret = skb_copy_datagram_iovec(skb, 0, m->msg_iov, copylen);
 333         if (ret)
 334                 goto out_free;
 335
 336         ret = (flags & MSG_TRUNC) ? skb->len : copylen;
 337 out_free:
 338         skb_free_datagram(sk, skb);
 339         caif_check_flow_release(sk);
 340         return ret;
 341
 342 read_error:
 343         return ret;
 344 }
 345
 346
 347 /* Copied from unix_stream_wait_data, identical except for lock call. */
 348 static long caif_stream_data_wait(struct sock *sk, long timeo)
 349 {
 350         DEFINE_WAIT(wait);
 351         lock_sock(sk);
 352
 353         for (;;) {
 354                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 355
 356                 if (!skb_queue_empty(&sk->sk_receive_queue) ||
 357                         sk->sk_err ||
 358                         sk->sk_state != CAIF_CONNECTED ||
 359                         sock_flag(sk, SOCK_DEAD) ||
 360                         (sk->sk_shutdown & RCV_SHUTDOWN) ||
 361                         signal_pending(current) ||
 362                         !timeo)
 363                         break;
 364
 365                 set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
 366                 release_sock(sk);
 367                 timeo = schedule_timeout(timeo);
 368                 lock_sock(sk);
 369
 370                 if (sock_flag(sk, SOCK_DEAD))
 371                         break;
 372
 373                 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
 374         }
 375
 376         finish_wait(sk_sleep(sk), &wait);
 377         release_sock(sk);
 378         return timeo;
 379 }
 380
 381
 382 /*
 383  * Copied from unix_stream_recvmsg, but removed credit checks,
 384  * changed locking calls, changed address handling.
 385  */
 386 static int caif_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
 387                                 struct msghdr *msg, size_t size,
 388                                 int flags)
 389 {
 390         struct sock *sk = sock->sk;
 391         int copied = 0;
 392         int target;
 393         int err = 0;
 394         long timeo;
 395
 396         err = -EOPNOTSUPP;
 397         if (flags&MSG_OOB)
 398                 goto out;
 399
 400         /*
 401          * Lock the socket to prevent queue disordering
 402          * while sleeps in memcpy_tomsg
 403          */
 404         err = -EAGAIN;
 405         if (sk->sk_state == CAIF_CONNECTING)
 406                 goto out;
 407
 408         caif_read_lock(sk);
 409         target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
 410         timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
 411
 412         do {
 413                 int chunk;
 414                 struct sk_buff *skb;
 415
 416                 lock_sock(sk);
 417                 if (sock_flag(sk, SOCK_DEAD)) {
 418                         err = -ECONNRESET;
 419                         goto unlock;
 420                 }
 421                 skb = skb_dequeue(&sk->sk_receive_queue);
 422                 caif_check_flow_release(sk);
 423
 424                 if (skb == NULL) {
 425                         if (copied >= target)
 426                                 goto unlock;
 427                         /*
 428                          *      POSIX 1003.1g mandates this order.
 429                          */
 430                         err = sock_error(sk);
 431                         if (err)
 432                                 goto unlock;
 433                         err = -ECONNRESET;
 434                         if (sk->sk_shutdown & RCV_SHUTDOWN)
 435                                 goto unlock;
 436
 437                         err = -EPIPE;
 438                         if (sk->sk_state != CAIF_CONNECTED)
 439                                 goto unlock;
 440                         if (sock_flag(sk, SOCK_DEAD))
 441                                 goto unlock;
 442
 443                         release_sock(sk);
 444
 445                         err = -EAGAIN;
 446                         if (!timeo)
 447                                 break;
 448
 449                         caif_read_unlock(sk);
 450
 451                         timeo = caif_stream_data_wait(sk, timeo);
 452
 453                         if (signal_pending(current)) {
 454                                 err = sock_intr_errno(timeo);
 455                                 goto out;
 456                         }
 457                         caif_read_lock(sk);
 458                         continue;
 459 unlock:
 460                         release_sock(sk);
 461                         break;
 462                 }
 463                 release_sock(sk);
 464                 chunk = min_t(unsigned int, skb->len, size);
 465                 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) {
 466                         skb_queue_head(&sk->sk_receive_queue, skb);
 467                         if (copied == 0)
 468                                 copied = -EFAULT;
 469                         break;
 470                 }
 471                 copied += chunk;
 472                 size -= chunk;
 473
 474                 /* Mark read part of skb as used */
 475                 if (!(flags & MSG_PEEK)) {
 476                         skb_pull(skb, chunk);
 477
 478                         /* put the skb back if we didn't use it up. */
 479                         if (skb->len) {
 480                                 skb_queue_head(&sk->sk_receive_queue, skb);
 481                                 break;
 482                         }
 483                         kfree_skb(skb);
 484
 485                 } else {
 486                         /*
 487                          * It is questionable, see note in unix_dgram_recvmsg.
 488                          */
 489                         /* put message back and return */
 490                         skb_queue_head(&sk->sk_receive_queue, skb);
 491                         break;
 492                 }
 493         } while (size);
 494         caif_read_unlock(sk);
 495
 496 out:
 497         return copied ? : err;
 498 }
 499
 500 /*
 501  * Copied from sock.c:sock_wait_for_wmem, but change to wait for
 502  * CAIF flow-on and sock_writable.
 503  */
 504 static long caif_wait_for_flow_on(struct caifsock *cf_sk,
 505                                 int wait_writeable, long timeo, int *err)
 506 {
 507         struct sock *sk = &cf_sk->sk;
 508         DEFINE_WAIT(wait);
 509         for (;;) {
 510                 *err = 0;
 511                 if (tx_flow_is_on(cf_sk) &&
 512                         (!wait_writeable || sock_writeable(&cf_sk->sk)))
 513                         break;
 514                 *err = -ETIMEDOUT;
 515                 if (!timeo)
 516                         break;
 517                 *err = -ERESTARTSYS;
 518                 if (signal_pending(current))
 519                         break;
 520                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 521                 *err = -ECONNRESET;
 522                 if (sk->sk_shutdown & SHUTDOWN_MASK)
 523                         break;
 524                 *err = -sk->sk_err;
 525                 if (sk->sk_err)
 526                         break;
 527                 *err = -EPIPE;
 528                 if (cf_sk->sk.sk_state != CAIF_CONNECTED)
 529                         break;
 530                 timeo = schedule_timeout(timeo);
 531         }
 532         finish_wait(sk_sleep(sk), &wait);
 533         return timeo;
 534 }
 535
 536 /*
 537  * Transmit a SKB. The device may temporarily request re-transmission
 538  * by returning EAGAIN.
 539  */
 540 static int transmit_skb(struct sk_buff *skb, struct caifsock *cf_sk,
 541                         int noblock, long timeo)
 542 {
 543         struct cfpkt *pkt;
 544
 545         pkt = cfpkt_fromnative(CAIF_DIR_OUT, skb);
 546         memset(skb->cb, 0, sizeof(struct caif_payload_info));
 547
 548         if (cf_sk->layer.dn == NULL)
 549                 return -EINVAL;
 550
 551         return cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt);
 552 }
 553
 554 /* Copied from af_unix:unix_dgram_sendmsg, and adapted to CAIF */
 555 static int caif_seqpkt_sendmsg(struct kiocb *kiocb, struct socket *sock,
 556                         struct msghdr *msg, size_t len)
 557 {
 558         struct sock *sk = sock->sk;
 559         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
 560         int buffer_size;
 561         int ret = 0;
 562         struct sk_buff *skb = NULL;
 563         int noblock;
 564         long timeo;
 565         caif_assert(cf_sk);
 566         ret = sock_error(sk);
 567         if (ret)
 568                 goto err;
 569
 570         ret = -EOPNOTSUPP;
 571         if (msg->msg_flags&MSG_OOB)
 572                 goto err;
 573
 574         ret = -EOPNOTSUPP;
 575         if (msg->msg_namelen)
 576                 goto err;
 577
 578         ret = -EINVAL;
 579         if (unlikely(msg->msg_iov->iov_base == NULL))
 580                 goto err;
 581         noblock = msg->msg_flags & MSG_DONTWAIT;
 582
 583         timeo = sock_sndtimeo(sk, noblock);
 584         timeo = caif_wait_for_flow_on(container_of(sk, struct caifsock, sk),
 585                                 1, timeo, &ret);
 586
 587         if (ret)
 588                 goto err;
 589         ret = -EPIPE;
 590         if (cf_sk->sk.sk_state != CAIF_CONNECTED ||
 591                 sock_flag(sk, SOCK_DEAD) ||
 592                 (sk->sk_shutdown & RCV_SHUTDOWN))
 593                 goto err;
 594
 595         /* Error if trying to write more than maximum frame size. */
 596         ret = -EMSGSIZE;
 597         if (len > cf_sk->maxframe && cf_sk->sk.sk_protocol != CAIFPROTO_RFM)
 598                 goto err;
 599
 600         buffer_size = len + cf_sk->headroom + cf_sk->tailroom;
 601
 602         ret = -ENOMEM;
 603         skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret);
 604
 605         if (!skb || skb_tailroom(skb) < buffer_size)
 606                 goto err;
 607
 608         skb_reserve(skb, cf_sk->headroom);
 609
 610         ret = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
 611
 612         if (ret)
 613                 goto err;
 614         ret = transmit_skb(skb, cf_sk, noblock, timeo);
 615         if (ret < 0)
 616                 /* skb is already freed */
 617                 return ret;
 618
 619         return len;
 620 err:
 621         kfree_skb(skb);
 622         return ret;
 623 }
 624
 625 /*
 626  * Copied from unix_stream_sendmsg and adapted to CAIF:
 627  * Changed removed permission handling and added waiting for flow on
 628  * and other minor adaptations.
 629  */
 630 static int caif_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
 631                                 struct msghdr *msg, size_t len)
 632 {
 633         struct sock *sk = sock->sk;
 634         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
 635         int err, size;
 636         struct sk_buff *skb;
 637         int sent = 0;
 638         long timeo;
 639
 640         err = -EOPNOTSUPP;
 641         if (unlikely(msg->msg_flags&MSG_OOB))
 642                 goto out_err;
 643
 644         if (unlikely(msg->msg_namelen))
 645                 goto out_err;
 646
 647         timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
 648         timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err);
 649
 650         if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN))
 651                 goto pipe_err;
 652
 653         while (sent < len) {
 654
 655                 size = len-sent;
 656
 657                 if (size > cf_sk->maxframe)
 658                         size = cf_sk->maxframe;
 659
 660                 /* If size is more than half of sndbuf, chop up message */
 661                 if (size > ((sk->sk_sndbuf >> 1) - 64))
 662                         size = (sk->sk_sndbuf >> 1) - 64;
 663
 664                 if (size > SKB_MAX_ALLOC)
 665                         size = SKB_MAX_ALLOC;
 666
 667                 skb = sock_alloc_send_skb(sk,
 668                                         size + cf_sk->headroom +
 669                                         cf_sk->tailroom,
 670                                         msg->msg_flags&MSG_DONTWAIT,
 671                                         &err);
 672                 if (skb == NULL)
 673                         goto out_err;
 674
 675                 skb_reserve(skb, cf_sk->headroom);
 676                 /*
 677                  *      If you pass two values to the sock_alloc_send_skb
 678                  *      it tries to grab the large buffer with GFP_NOFS
 679                  *      (which can fail easily), and if it fails grab the
 680                  *      fallback size buffer which is under a page and will
 681                  *      succeed. [Alan]
 682                  */
 683                 size = min_t(int, size, skb_tailroom(skb));
 684
 685                 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
 686                 if (err) {
 687                         kfree_skb(skb);
 688                         goto out_err;
 689                 }
 690                 err = transmit_skb(skb, cf_sk,
 691                                 msg->msg_flags&MSG_DONTWAIT, timeo);
 692                 if (err < 0) {
 693                         kfree_skb(skb);
 694                         goto pipe_err;
 695                 }
 696                 sent += size;
 697         }
 698
 699         return sent;
 700
 701 pipe_err:
 702         if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
 703                 send_sig(SIGPIPE, current, 0);
 704         err = -EPIPE;
 705 out_err:
 706         return sent ? : err;
 707 }
 708
 709 static int setsockopt(struct socket *sock,
 710                         int lvl, int opt, char __user *ov, unsigned int ol)
 711 {
 712         struct sock *sk = sock->sk;
 713         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
 714         int linksel;
 715
 716         if (cf_sk->sk.sk_socket->state != SS_UNCONNECTED)
 717                 return -ENOPROTOOPT;
 718
 719         switch (opt) {
 720         case CAIFSO_LINK_SELECT:
 721                 if (ol < sizeof(int))
 722                         return -EINVAL;
 723                 if (lvl != SOL_CAIF)
 724                         goto bad_sol;
 725                 if (copy_from_user(&linksel, ov, sizeof(int)))
 726                         return -EINVAL;
 727                 lock_sock(&(cf_sk->sk));
 728                 cf_sk->conn_req.link_selector = linksel;
 729                 release_sock(&cf_sk->sk);
 730                 return 0;
 731
 732         case CAIFSO_REQ_PARAM:
 733                 if (lvl != SOL_CAIF)
 734                         goto bad_sol;
 735                 if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL)
 736                         return -ENOPROTOOPT;
 737                 lock_sock(&(cf_sk->sk));
 738                 if (ol > sizeof(cf_sk->conn_req.param.data) ||
 739                         copy_from_user(&cf_sk->conn_req.param.data, ov, ol)) {
 740                         release_sock(&cf_sk->sk);
 741                         return -EINVAL;
 742                 }
 743                 cf_sk->conn_req.param.size = ol;
 744                 release_sock(&cf_sk->sk);
 745                 return 0;
 746
 747         default:
 748                 return -ENOPROTOOPT;
 749         }
 750
 751         return 0;
 752 bad_sol:
 753         return -ENOPROTOOPT;
 754
 755 }
 756
 757 /*
 758  * caif_connect() - Connect a CAIF Socket
 759  * Copied and modified af_irda.c:irda_connect().
 760  *
 761  * Note : by consulting "errno", the user space caller may learn the cause
 762  * of the failure. Most of them are visible in the function, others may come
 763  * from subroutines called and are listed here :
 764  *  o -EAFNOSUPPORT: bad socket family or type.
 765  *  o -ESOCKTNOSUPPORT: bad socket type or protocol
 766  *  o -EINVAL: bad socket address, or CAIF link type
 767  *  o -ECONNREFUSED: remote end refused the connection.
 768  *  o -EINPROGRESS: connect request sent but timed out (or non-blocking)
 769  *  o -EISCONN: already connected.
 770  *  o -ETIMEDOUT: Connection timed out (send timeout)
 771  *  o -ENODEV: No link layer to send request
 772  *  o -ECONNRESET: Received Shutdown indication or lost link layer
 773  *  o -ENOMEM: Out of memory
 774  *
 775  *  State Strategy:
 776  *  o sk_state: holds the CAIF_* protocol state, it's updated by
 777  *      caif_ctrl_cb.
 778  *  o sock->state: holds the SS_* socket state and is updated by connect and
 779  *      disconnect.
 780  */
 781 static int caif_connect(struct socket *sock, struct sockaddr *uaddr,
 782                         int addr_len, int flags)
 783 {
 784         struct sock *sk = sock->sk;
 785         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
 786         long timeo;
 787         int err;
 788         int ifindex, headroom, tailroom;
 789         unsigned int mtu;
 790         struct net_device *dev;
 791
 792         lock_sock(sk);
 793
 794         err = -EAFNOSUPPORT;
 795         if (uaddr->sa_family != AF_CAIF)
 796                 goto out;
 797
 798         switch (sock->state) {
 799         case SS_UNCONNECTED:
 800                 /* Normal case, a fresh connect */
 801                 caif_assert(sk->sk_state == CAIF_DISCONNECTED);
 802                 break;
 803         case SS_CONNECTING:
 804                 switch (sk->sk_state) {
 805                 case CAIF_CONNECTED:
 806                         sock->state = SS_CONNECTED;
 807                         err = -EISCONN;
 808                         goto out;
 809                 case CAIF_DISCONNECTED:
 810                         /* Reconnect allowed */
 811                         break;
 812                 case CAIF_CONNECTING:
 813                         err = -EALREADY;
 814                         if (flags & O_NONBLOCK)
 815                                 goto out;
 816                         goto wait_connect;
 817                 }
 818                 break;
 819         case SS_CONNECTED:
 820                 caif_assert(sk->sk_state == CAIF_CONNECTED ||
 821                                 sk->sk_state == CAIF_DISCONNECTED);
 822                 if (sk->sk_shutdown & SHUTDOWN_MASK) {
 823                         /* Allow re-connect after SHUTDOWN_IND */
 824                         caif_disconnect_client(sock_net(sk), &cf_sk->layer);
 825                         caif_free_client(&cf_sk->layer);
 826                         break;
 827                 }
 828                 /* No reconnect on a seqpacket socket */
 829                 err = -EISCONN;
 830                 goto out;
 831         case SS_DISCONNECTING:
 832         case SS_FREE:
 833                 caif_assert(1); /*Should never happen */
 834                 break;
 835         }
 836         sk->sk_state = CAIF_DISCONNECTED;
 837         sock->state = SS_UNCONNECTED;
 838         sk_stream_kill_queues(&cf_sk->sk);
 839
 840         err = -EINVAL;
 841         if (addr_len != sizeof(struct sockaddr_caif))
 842                 goto out;
 843
 844         memcpy(&cf_sk->conn_req.sockaddr, uaddr,
 845                 sizeof(struct sockaddr_caif));
 846
 847         /* Move to connecting socket, start sending Connect Requests */
 848         sock->state = SS_CONNECTING;
 849         sk->sk_state = CAIF_CONNECTING;
 850
 851         /* Check priority value comming from socket */
 852         /* if priority value is out of range it will be ajusted */
 853         if (cf_sk->sk.sk_priority > CAIF_PRIO_MAX)
 854                 cf_sk->conn_req.priority = CAIF_PRIO_MAX;
 855         else if (cf_sk->sk.sk_priority < CAIF_PRIO_MIN)
 856                 cf_sk->conn_req.priority = CAIF_PRIO_MIN;
 857         else
 858                 cf_sk->conn_req.priority = cf_sk->sk.sk_priority;
 859
 860         /*ifindex = id of the interface.*/
 861         cf_sk->conn_req.ifindex = cf_sk->sk.sk_bound_dev_if;
 862
 863         dbfs_atomic_inc(&cnt.num_connect_req);
 864         cf_sk->layer.receive = caif_sktrecv_cb;
 865
 866         err = caif_connect_client(sock_net(sk), &cf_sk->conn_req,
 867                                 &cf_sk->layer, &ifindex, &headroom, &tailroom);
 868
 869         if (err < 0) {
 870                 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
 871                 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
 872                 goto out;
 873         }
 874
 875         err = -ENODEV;
 876         rcu_read_lock();
 877         dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
 878         if (!dev) {
 879                 rcu_read_unlock();
 880                 goto out;
 881         }
 882         cf_sk->headroom = LL_RESERVED_SPACE_EXTRA(dev, headroom);
 883         mtu = dev->mtu;
 884         rcu_read_unlock();
 885
 886         cf_sk->tailroom = tailroom;
 887         cf_sk->maxframe = mtu - (headroom + tailroom);
 888         if (cf_sk->maxframe < 1) {
 889                 pr_warn("CAIF Interface MTU too small (%d)\n", dev->mtu);
 890                 err = -ENODEV;
 891                 goto out;
 892         }
 893
 894         err = -EINPROGRESS;
 895 wait_connect:
 896
 897         if (sk->sk_state != CAIF_CONNECTED && (flags & O_NONBLOCK))
 898                 goto out;
 899
 900         timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
 901
 902         release_sock(sk);
 903         err = -ERESTARTSYS;
 904         timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
 905                         sk->sk_state != CAIF_CONNECTING,
 906                         timeo);
 907         lock_sock(sk);
 908         if (timeo < 0)
 909                 goto out; /* -ERESTARTSYS */
 910
 911         err = -ETIMEDOUT;
 912         if (timeo == 0 && sk->sk_state != CAIF_CONNECTED)
 913                 goto out;
 914         if (sk->sk_state != CAIF_CONNECTED) {
 915                 sock->state = SS_UNCONNECTED;
 916                 err = sock_error(sk);
 917                 if (!err)
 918                         err = -ECONNREFUSED;
 919                 goto out;
 920         }
 921         sock->state = SS_CONNECTED;
 922         err = 0;
 923 out:
 924         release_sock(sk);
 925         return err;
 926 }
 927
 928 /*
 929  * caif_release() - Disconnect a CAIF Socket
 930  * Copied and modified af_irda.c:irda_release().
 931  */
 932 static int caif_release(struct socket *sock)
 933 {
 934         struct sock *sk = sock->sk;
 935         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
 936
 937         if (!sk)
 938                 return 0;
 939
 940         set_tx_flow_off(cf_sk);
 941
 942         /*
 943          * Ensure that packets are not queued after this point in time.
 944          * caif_queue_rcv_skb checks SOCK_DEAD holding the queue lock,
 945          * this ensures no packets when sock is dead.
 946          */
 947         spin_lock_bh(&sk->sk_receive_queue.lock);
 948         sock_set_flag(sk, SOCK_DEAD);
 949         spin_unlock_bh(&sk->sk_receive_queue.lock);
 950         sock->sk = NULL;
 951
 952         dbfs_atomic_inc(&cnt.num_disconnect);
 953
 954         WARN_ON(IS_ERR(cf_sk->debugfs_socket_dir));
 955         if (cf_sk->debugfs_socket_dir != NULL)
 956                 debugfs_remove_recursive(cf_sk->debugfs_socket_dir);
 957
 958         lock_sock(&(cf_sk->sk));
 959         sk->sk_state = CAIF_DISCONNECTED;
 960         sk->sk_shutdown = SHUTDOWN_MASK;
 961
 962         caif_disconnect_client(sock_net(sk), &cf_sk->layer);
 963         cf_sk->sk.sk_socket->state = SS_DISCONNECTING;
 964         wake_up_interruptible_poll(sk_sleep(sk), POLLERR|POLLHUP);
 965
 966         sock_orphan(sk);
 967         sk_stream_kill_queues(&cf_sk->sk);
 968         release_sock(sk);
 969         sock_put(sk);
 970         return 0;
 971 }
 972
 973 /* Copied from af_unix.c:unix_poll(), added CAIF tx_flow handling */
 974 static unsigned int caif_poll(struct file *file,
 975                                 struct socket *sock, poll_table *wait)
 976 {
 977         struct sock *sk = sock->sk;
 978         unsigned int mask;
 979         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
 980
 981         sock_poll_wait(file, sk_sleep(sk), wait);
 982         mask = 0;
 983
 984         /* exceptional events? */
 985         if (sk->sk_err)
 986                 mask |= POLLERR;
 987         if (sk->sk_shutdown == SHUTDOWN_MASK)
 988                 mask |= POLLHUP;
 989         if (sk->sk_shutdown & RCV_SHUTDOWN)
 990                 mask |= POLLRDHUP;
 991
 992         /* readable? */
 993         if (!skb_queue_empty(&sk->sk_receive_queue) ||
 994                 (sk->sk_shutdown & RCV_SHUTDOWN))
 995                 mask |= POLLIN | POLLRDNORM;
 996
 997         /*
 998          * we set writable also when the other side has shut down the
 999          * connection. This prevents stuck sockets.
1000          */
1001         if (sock_writeable(sk) && tx_flow_is_on(cf_sk))
1002                 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
1003
1004         return mask;
1005 }
1006
1007 static const struct proto_ops caif_seqpacket_ops = {
1008         .family = PF_CAIF,
1009         .owner = THIS_MODULE,
1010         .release = caif_release,
1011         .bind = sock_no_bind,
1012         .connect = caif_connect,
1013         .socketpair = sock_no_socketpair,
1014         .accept = sock_no_accept,
1015         .getname = sock_no_getname,
1016         .poll = caif_poll,
1017         .ioctl = sock_no_ioctl,
1018         .listen = sock_no_listen,
1019         .shutdown = sock_no_shutdown,
1020         .setsockopt = setsockopt,
1021         .getsockopt = sock_no_getsockopt,
1022         .sendmsg = caif_seqpkt_sendmsg,
1023         .recvmsg = caif_seqpkt_recvmsg,
1024         .mmap = sock_no_mmap,
1025         .sendpage = sock_no_sendpage,
1026 };
1027
1028 static const struct proto_ops caif_stream_ops = {
1029         .family = PF_CAIF,
1030         .owner = THIS_MODULE,
1031         .release = caif_release,
1032         .bind = sock_no_bind,
1033         .connect = caif_connect,
1034         .socketpair = sock_no_socketpair,
1035         .accept = sock_no_accept,
1036         .getname = sock_no_getname,
1037         .poll = caif_poll,
1038         .ioctl = sock_no_ioctl,
1039         .listen = sock_no_listen,
1040         .shutdown = sock_no_shutdown,
1041         .setsockopt = setsockopt,
1042         .getsockopt = sock_no_getsockopt,
1043         .sendmsg = caif_stream_sendmsg,
1044         .recvmsg = caif_stream_recvmsg,
1045         .mmap = sock_no_mmap,
1046         .sendpage = sock_no_sendpage,
1047 };
1048
1049 /* This function is called when a socket is finally destroyed. */
1050 static void caif_sock_destructor(struct sock *sk)
1051 {
1052         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
1053         caif_assert(!atomic_read(&sk->sk_wmem_alloc));
1054         caif_assert(sk_unhashed(sk));
1055         caif_assert(!sk->sk_socket);
1056         if (!sock_flag(sk, SOCK_DEAD)) {
1057                 pr_debug("Attempt to release alive CAIF socket: %p\n", sk);
1058                 return;
1059         }
1060         sk_stream_kill_queues(&cf_sk->sk);
1061         dbfs_atomic_dec(&cnt.caif_nr_socks);
1062         caif_free_client(&cf_sk->layer);
1063 }
1064
1065 static int caif_create(struct net *net, struct socket *sock, int protocol,
1066                         int kern)
1067 {
1068         int num;
1069         struct sock *sk = NULL;
1070         struct caifsock *cf_sk = NULL;
1071         static struct proto prot = {.name = "PF_CAIF",
1072                 .owner = THIS_MODULE,
1073                 .obj_size = sizeof(struct caifsock),
1074         };
1075
1076         if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN))
1077                 return -EPERM;
1078         /*
1079          * The sock->type specifies the socket type to use.
1080          * The CAIF socket is a packet stream in the sense
1081          * that it is packet based. CAIF trusts the reliability
1082          * of the link, no resending is implemented.
1083          */
1084         if (sock->type == SOCK_SEQPACKET)
1085                 sock->ops = &caif_seqpacket_ops;
1086         else if (sock->type == SOCK_STREAM)
1087                 sock->ops = &caif_stream_ops;
1088         else
1089                 return -ESOCKTNOSUPPORT;
1090
1091         if (protocol < 0 || protocol >= CAIFPROTO_MAX)
1092                 return -EPROTONOSUPPORT;
1093         /*
1094          * Set the socket state to unconnected.  The socket state
1095          * is really not used at all in the net/core or socket.c but the
1096          * initialization makes sure that sock->state is not uninitialized.
1097          */
1098         sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot);
1099         if (!sk)
1100                 return -ENOMEM;
1101
1102         cf_sk = container_of(sk, struct caifsock, sk);
1103
1104         /* Store the protocol */
1105         sk->sk_protocol = (unsigned char) protocol;
1106
1107         /*
1108          * Lock in order to try to stop someone from opening the socket
1109          * too early.
1110          */
1111         lock_sock(&(cf_sk->sk));
1112
1113         /* Initialize the nozero default sock structure data. */
1114         sock_init_data(sock, sk);
1115         sk->sk_destruct = caif_sock_destructor;
1116
1117         mutex_init(&cf_sk->readlock); /* single task reading lock */
1118         cf_sk->layer.ctrlcmd = caif_ctrl_cb;
1119         cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
1120         cf_sk->sk.sk_state = CAIF_DISCONNECTED;
1121
1122         set_tx_flow_off(cf_sk);
1123         set_rx_flow_on(cf_sk);
1124
1125         /* Set default options on configuration */
1126         cf_sk->sk.sk_priority = CAIF_PRIO_NORMAL;
1127         cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY;
1128         cf_sk->conn_req.protocol = protocol;
1129         /* Increase the number of sockets created. */
1130         dbfs_atomic_inc(&cnt.caif_nr_socks);
1131         num = dbfs_atomic_inc(&cnt.caif_sock_create);
1132 #ifdef CONFIG_DEBUG_FS
1133         if (!IS_ERR(debugfsdir)) {
1134
1135                 /* Fill in some information concerning the misc socket. */
1136                 snprintf(cf_sk->name, sizeof(cf_sk->name), "cfsk%d", num);
1137
1138                 cf_sk->debugfs_socket_dir =
1139                         debugfs_create_dir(cf_sk->name, debugfsdir);
1140
1141                 debugfs_create_u32("sk_state", S_IRUSR | S_IWUSR,
1142                                 cf_sk->debugfs_socket_dir,
1143                                 (u32 *) &cf_sk->sk.sk_state);
1144                 debugfs_create_u32("flow_state", S_IRUSR | S_IWUSR,
1145                                 cf_sk->debugfs_socket_dir, &cf_sk->flow_state);
1146                 debugfs_create_u32("sk_rmem_alloc", S_IRUSR | S_IWUSR,
1147                                 cf_sk->debugfs_socket_dir,
1148                                 (u32 *) &cf_sk->sk.sk_rmem_alloc);
1149                 debugfs_create_u32("sk_wmem_alloc", S_IRUSR | S_IWUSR,
1150                                 cf_sk->debugfs_socket_dir,
1151                                 (u32 *) &cf_sk->sk.sk_wmem_alloc);
1152                 debugfs_create_u32("identity", S_IRUSR | S_IWUSR,
1153                                 cf_sk->debugfs_socket_dir,
1154                                 (u32 *) &cf_sk->layer.id);
1155         }
1156 #endif
1157         release_sock(&cf_sk->sk);
1158         return 0;
1159 }
1160
1161
1162 static struct net_proto_family caif_family_ops = {
1163         .family = PF_CAIF,
1164         .create = caif_create,
1165         .owner = THIS_MODULE,
1166 };
1167
1168 static int af_caif_init(void)
1169 {
1170         int err = sock_register(&caif_family_ops);
1171         if (!err)
1172                 return err;
1173         return 0;
1174 }
1175
1176 static int __init caif_sktinit_module(void)
1177 {
1178 #ifdef CONFIG_DEBUG_FS
1179         debugfsdir = debugfs_create_dir("caif_sk", NULL);
1180         if (!IS_ERR(debugfsdir)) {
1181                 debugfs_create_u32("num_sockets", S_IRUSR | S_IWUSR,
1182                                 debugfsdir,
1183                                 (u32 *) &cnt.caif_nr_socks);
1184                 debugfs_create_u32("num_create", S_IRUSR | S_IWUSR,
1185                                 debugfsdir,
1186                                 (u32 *) &cnt.caif_sock_create);
1187                 debugfs_create_u32("num_connect_req", S_IRUSR | S_IWUSR,
1188                                 debugfsdir,
1189                                 (u32 *) &cnt.num_connect_req);
1190                 debugfs_create_u32("num_connect_resp", S_IRUSR | S_IWUSR,
1191                                 debugfsdir,
1192                                 (u32 *) &cnt.num_connect_resp);
1193                 debugfs_create_u32("num_connect_fail_resp", S_IRUSR | S_IWUSR,
1194                                 debugfsdir,
1195                                 (u32 *) &cnt.num_connect_fail_resp);
1196                 debugfs_create_u32("num_disconnect", S_IRUSR | S_IWUSR,
1197                                 debugfsdir,
1198                                 (u32 *) &cnt.num_disconnect);
1199                 debugfs_create_u32("num_remote_shutdown_ind",
1200                                 S_IRUSR | S_IWUSR, debugfsdir,
1201                                 (u32 *) &cnt.num_remote_shutdown_ind);
1202                 debugfs_create_u32("num_tx_flow_off_ind", S_IRUSR | S_IWUSR,
1203                                 debugfsdir,
1204                                 (u32 *) &cnt.num_tx_flow_off_ind);
1205                 debugfs_create_u32("num_tx_flow_on_ind", S_IRUSR | S_IWUSR,
1206                                 debugfsdir,
1207                                 (u32 *) &cnt.num_tx_flow_on_ind);
1208                 debugfs_create_u32("num_rx_flow_off", S_IRUSR | S_IWUSR,
1209                                 debugfsdir,
1210                                 (u32 *) &cnt.num_rx_flow_off);
1211                 debugfs_create_u32("num_rx_flow_on", S_IRUSR | S_IWUSR,
1212                                 debugfsdir,
1213                                 (u32 *) &cnt.num_rx_flow_on);
1214         }
1215 #endif
1216         return af_caif_init();
1217 }
1218
1219 static void __exit caif_sktexit_module(void)
1220 {
1221         sock_unregister(PF_CAIF);
1222         if (debugfsdir != NULL)
1223                 debugfs_remove_recursive(debugfsdir);
1224 }
1225 module_init(caif_sktinit_module);
1226 module_exit(caif_sktexit_module);