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 (m->msg_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                 clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
 370         }
 371
 372         finish_wait(sk_sleep(sk), &wait);
 373         release_sock(sk);
 374         return timeo;
 375 }
 376
 377
 378 /*
 379  * Copied from unix_stream_recvmsg, but removed credit checks,
 380  * changed locking calls, changed address handling.
 381  */
 382 static int caif_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
 383                                 struct msghdr *msg, size_t size,
 384                                 int flags)
 385 {
 386         struct sock *sk = sock->sk;
 387         int copied = 0;
 388         int target;
 389         int err = 0;
 390         long timeo;
 391
 392         err = -EOPNOTSUPP;
 393         if (flags&MSG_OOB)
 394                 goto out;
 395
 396         msg->msg_namelen = 0;
 397
 398         /*
 399          * Lock the socket to prevent queue disordering
 400          * while sleeps in memcpy_tomsg
 401          */
 402         err = -EAGAIN;
 403         if (sk->sk_state == CAIF_CONNECTING)
 404                 goto out;
 405
 406         caif_read_lock(sk);
 407         target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
 408         timeo = sock_rcvtimeo(sk, flags&MSG_DONTWAIT);
 409
 410         do {
 411                 int chunk;
 412                 struct sk_buff *skb;
 413
 414                 lock_sock(sk);
 415                 skb = skb_dequeue(&sk->sk_receive_queue);
 416                 caif_check_flow_release(sk);
 417
 418                 if (skb == NULL) {
 419                         if (copied >= target)
 420                                 goto unlock;
 421                         /*
 422                          *      POSIX 1003.1g mandates this order.
 423                          */
 424                         err = sock_error(sk);
 425                         if (err)
 426                                 goto unlock;
 427                         err = -ECONNRESET;
 428                         if (sk->sk_shutdown & RCV_SHUTDOWN)
 429                                 goto unlock;
 430
 431                         err = -EPIPE;
 432                         if (sk->sk_state != CAIF_CONNECTED)
 433                                 goto unlock;
 434                         if (sock_flag(sk, SOCK_DEAD))
 435                                 goto unlock;
 436
 437                         release_sock(sk);
 438
 439                         err = -EAGAIN;
 440                         if (!timeo)
 441                                 break;
 442
 443                         caif_read_unlock(sk);
 444
 445                         timeo = caif_stream_data_wait(sk, timeo);
 446
 447                         if (signal_pending(current)) {
 448                                 err = sock_intr_errno(timeo);
 449                                 goto out;
 450                         }
 451                         caif_read_lock(sk);
 452                         continue;
 453 unlock:
 454                         release_sock(sk);
 455                         break;
 456                 }
 457                 release_sock(sk);
 458                 chunk = min_t(unsigned int, skb->len, size);
 459                 if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) {
 460                         skb_queue_head(&sk->sk_receive_queue, skb);
 461                         if (copied == 0)
 462                                 copied = -EFAULT;
 463                         break;
 464                 }
 465                 copied += chunk;
 466                 size -= chunk;
 467
 468                 /* Mark read part of skb as used */
 469                 if (!(flags & MSG_PEEK)) {
 470                         skb_pull(skb, chunk);
 471
 472                         /* put the skb back if we didn't use it up. */
 473                         if (skb->len) {
 474                                 skb_queue_head(&sk->sk_receive_queue, skb);
 475                                 break;
 476                         }
 477                         kfree_skb(skb);
 478
 479                 } else {
 480                         /*
 481                          * It is questionable, see note in unix_dgram_recvmsg.
 482                          */
 483                         /* put message back and return */
 484                         skb_queue_head(&sk->sk_receive_queue, skb);
 485                         break;
 486                 }
 487         } while (size);
 488         caif_read_unlock(sk);
 489
 490 out:
 491         return copied ? : err;
 492 }
 493
 494 /*
 495  * Copied from sock.c:sock_wait_for_wmem, but change to wait for
 496  * CAIF flow-on and sock_writable.
 497  */
 498 static long caif_wait_for_flow_on(struct caifsock *cf_sk,
 499                                 int wait_writeable, long timeo, int *err)
 500 {
 501         struct sock *sk = &cf_sk->sk;
 502         DEFINE_WAIT(wait);
 503         for (;;) {
 504                 *err = 0;
 505                 if (tx_flow_is_on(cf_sk) &&
 506                         (!wait_writeable || sock_writeable(&cf_sk->sk)))
 507                         break;
 508                 *err = -ETIMEDOUT;
 509                 if (!timeo)
 510                         break;
 511                 *err = -ERESTARTSYS;
 512                 if (signal_pending(current))
 513                         break;
 514                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 515                 *err = -ECONNRESET;
 516                 if (sk->sk_shutdown & SHUTDOWN_MASK)
 517                         break;
 518                 *err = -sk->sk_err;
 519                 if (sk->sk_err)
 520                         break;
 521                 *err = -EPIPE;
 522                 if (cf_sk->sk.sk_state != CAIF_CONNECTED)
 523                         break;
 524                 timeo = schedule_timeout(timeo);
 525         }
 526         finish_wait(sk_sleep(sk), &wait);
 527         return timeo;
 528 }
 529
 530 /*
 531  * Transmit a SKB. The device may temporarily request re-transmission
 532  * by returning EAGAIN.
 533  */
 534 static int transmit_skb(struct sk_buff *skb, struct caifsock *cf_sk,
 535                         int noblock, long timeo)
 536 {
 537         struct cfpkt *pkt;
 538
 539         pkt = cfpkt_fromnative(CAIF_DIR_OUT, skb);
 540         memset(skb->cb, 0, sizeof(struct caif_payload_info));
 541
 542         if (cf_sk->layer.dn == NULL)
 543                 return -EINVAL;
 544
 545         return cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt);
 546 }
 547
 548 /* Copied from af_unix:unix_dgram_sendmsg, and adapted to CAIF */
 549 static int caif_seqpkt_sendmsg(struct kiocb *kiocb, struct socket *sock,
 550                         struct msghdr *msg, size_t len)
 551 {
 552         struct sock *sk = sock->sk;
 553         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
 554         int buffer_size;
 555         int ret = 0;
 556         struct sk_buff *skb = NULL;
 557         int noblock;
 558         long timeo;
 559         caif_assert(cf_sk);
 560         ret = sock_error(sk);
 561         if (ret)
 562                 goto err;
 563
 564         ret = -EOPNOTSUPP;
 565         if (msg->msg_flags&MSG_OOB)
 566                 goto err;
 567
 568         ret = -EOPNOTSUPP;
 569         if (msg->msg_namelen)
 570                 goto err;
 571
 572         ret = -EINVAL;
 573         if (unlikely(msg->msg_iov->iov_base == NULL))
 574                 goto err;
 575         noblock = msg->msg_flags & MSG_DONTWAIT;
 576
 577         timeo = sock_sndtimeo(sk, noblock);
 578         timeo = caif_wait_for_flow_on(container_of(sk, struct caifsock, sk),
 579                                 1, timeo, &ret);
 580
 581         if (ret)
 582                 goto err;
 583         ret = -EPIPE;
 584         if (cf_sk->sk.sk_state != CAIF_CONNECTED ||
 585                 sock_flag(sk, SOCK_DEAD) ||
 586                 (sk->sk_shutdown & RCV_SHUTDOWN))
 587                 goto err;
 588
 589         /* Error if trying to write more than maximum frame size. */
 590         ret = -EMSGSIZE;
 591         if (len > cf_sk->maxframe && cf_sk->sk.sk_protocol != CAIFPROTO_RFM)
 592                 goto err;
 593
 594         buffer_size = len + cf_sk->headroom + cf_sk->tailroom;
 595
 596         ret = -ENOMEM;
 597         skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret);
 598
 599         if (!skb || skb_tailroom(skb) < buffer_size)
 600                 goto err;
 601
 602         skb_reserve(skb, cf_sk->headroom);
 603
 604         ret = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
 605
 606         if (ret)
 607                 goto err;
 608         ret = transmit_skb(skb, cf_sk, noblock, timeo);
 609         if (ret < 0)
 610                 /* skb is already freed */
 611                 return ret;
 612
 613         return len;
 614 err:
 615         kfree_skb(skb);
 616         return ret;
 617 }
 618
 619 /*
 620  * Copied from unix_stream_sendmsg and adapted to CAIF:
 621  * Changed removed permission handling and added waiting for flow on
 622  * and other minor adaptations.
 623  */
 624 static int caif_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
 625                                 struct msghdr *msg, size_t len)
 626 {
 627         struct sock *sk = sock->sk;
 628         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
 629         int err, size;
 630         struct sk_buff *skb;
 631         int sent = 0;
 632         long timeo;
 633
 634         err = -EOPNOTSUPP;
 635         if (unlikely(msg->msg_flags&MSG_OOB))
 636                 goto out_err;
 637
 638         if (unlikely(msg->msg_namelen))
 639                 goto out_err;
 640
 641         timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
 642         timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err);
 643
 644         if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN))
 645                 goto pipe_err;
 646
 647         while (sent < len) {
 648
 649                 size = len-sent;
 650
 651                 if (size > cf_sk->maxframe)
 652                         size = cf_sk->maxframe;
 653
 654                 /* If size is more than half of sndbuf, chop up message */
 655                 if (size > ((sk->sk_sndbuf >> 1) - 64))
 656                         size = (sk->sk_sndbuf >> 1) - 64;
 657
 658                 if (size > SKB_MAX_ALLOC)
 659                         size = SKB_MAX_ALLOC;
 660
 661                 skb = sock_alloc_send_skb(sk,
 662                                         size + cf_sk->headroom +
 663                                         cf_sk->tailroom,
 664                                         msg->msg_flags&MSG_DONTWAIT,
 665                                         &err);
 666                 if (skb == NULL)
 667                         goto out_err;
 668
 669                 skb_reserve(skb, cf_sk->headroom);
 670                 /*
 671                  *      If you pass two values to the sock_alloc_send_skb
 672                  *      it tries to grab the large buffer with GFP_NOFS
 673                  *      (which can fail easily), and if it fails grab the
 674                  *      fallback size buffer which is under a page and will
 675                  *      succeed. [Alan]
 676                  */
 677                 size = min_t(int, size, skb_tailroom(skb));
 678
 679                 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size);
 680                 if (err) {
 681                         kfree_skb(skb);
 682                         goto out_err;
 683                 }
 684                 err = transmit_skb(skb, cf_sk,
 685                                 msg->msg_flags&MSG_DONTWAIT, timeo);
 686                 if (err < 0) {
 687                         kfree_skb(skb);
 688                         goto pipe_err;
 689                 }
 690                 sent += size;
 691         }
 692
 693         return sent;
 694
 695 pipe_err:
 696         if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL))
 697                 send_sig(SIGPIPE, current, 0);
 698         err = -EPIPE;
 699 out_err:
 700         return sent ? : err;
 701 }
 702
 703 static int setsockopt(struct socket *sock,
 704                         int lvl, int opt, char __user *ov, unsigned int ol)
 705 {
 706         struct sock *sk = sock->sk;
 707         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
 708         int linksel;
 709
 710         if (cf_sk->sk.sk_socket->state != SS_UNCONNECTED)
 711                 return -ENOPROTOOPT;
 712
 713         switch (opt) {
 714         case CAIFSO_LINK_SELECT:
 715                 if (ol < sizeof(int))
 716                         return -EINVAL;
 717                 if (lvl != SOL_CAIF)
 718                         goto bad_sol;
 719                 if (copy_from_user(&linksel, ov, sizeof(int)))
 720                         return -EINVAL;
 721                 lock_sock(&(cf_sk->sk));
 722                 cf_sk->conn_req.link_selector = linksel;
 723                 release_sock(&cf_sk->sk);
 724                 return 0;
 725
 726         case CAIFSO_REQ_PARAM:
 727                 if (lvl != SOL_CAIF)
 728                         goto bad_sol;
 729                 if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL)
 730                         return -ENOPROTOOPT;
 731                 lock_sock(&(cf_sk->sk));
 732                 if (ol > sizeof(cf_sk->conn_req.param.data) ||
 733                         copy_from_user(&cf_sk->conn_req.param.data, ov, ol)) {
 734                         release_sock(&cf_sk->sk);
 735                         return -EINVAL;
 736                 }
 737                 cf_sk->conn_req.param.size = ol;
 738                 release_sock(&cf_sk->sk);
 739                 return 0;
 740
 741         default:
 742                 return -ENOPROTOOPT;
 743         }
 744
 745         return 0;
 746 bad_sol:
 747         return -ENOPROTOOPT;
 748
 749 }
 750
 751 /*
 752  * caif_connect() - Connect a CAIF Socket
 753  * Copied and modified af_irda.c:irda_connect().
 754  *
 755  * Note : by consulting "errno", the user space caller may learn the cause
 756  * of the failure. Most of them are visible in the function, others may come
 757  * from subroutines called and are listed here :
 758  *  o -EAFNOSUPPORT: bad socket family or type.
 759  *  o -ESOCKTNOSUPPORT: bad socket type or protocol
 760  *  o -EINVAL: bad socket address, or CAIF link type
 761  *  o -ECONNREFUSED: remote end refused the connection.
 762  *  o -EINPROGRESS: connect request sent but timed out (or non-blocking)
 763  *  o -EISCONN: already connected.
 764  *  o -ETIMEDOUT: Connection timed out (send timeout)
 765  *  o -ENODEV: No link layer to send request
 766  *  o -ECONNRESET: Received Shutdown indication or lost link layer
 767  *  o -ENOMEM: Out of memory
 768  *
 769  *  State Strategy:
 770  *  o sk_state: holds the CAIF_* protocol state, it's updated by
 771  *      caif_ctrl_cb.
 772  *  o sock->state: holds the SS_* socket state and is updated by connect and
 773  *      disconnect.
 774  */
 775 static int caif_connect(struct socket *sock, struct sockaddr *uaddr,
 776                         int addr_len, int flags)
 777 {
 778         struct sock *sk = sock->sk;
 779         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
 780         long timeo;
 781         int err;
 782         int ifindex, headroom, tailroom;
 783         unsigned int mtu;
 784         struct net_device *dev;
 785
 786         lock_sock(sk);
 787
 788         err = -EAFNOSUPPORT;
 789         if (uaddr->sa_family != AF_CAIF)
 790                 goto out;
 791
 792         switch (sock->state) {
 793         case SS_UNCONNECTED:
 794                 /* Normal case, a fresh connect */
 795                 caif_assert(sk->sk_state == CAIF_DISCONNECTED);
 796                 break;
 797         case SS_CONNECTING:
 798                 switch (sk->sk_state) {
 799                 case CAIF_CONNECTED:
 800                         sock->state = SS_CONNECTED;
 801                         err = -EISCONN;
 802                         goto out;
 803                 case CAIF_DISCONNECTED:
 804                         /* Reconnect allowed */
 805                         break;
 806                 case CAIF_CONNECTING:
 807                         err = -EALREADY;
 808                         if (flags & O_NONBLOCK)
 809                                 goto out;
 810                         goto wait_connect;
 811                 }
 812                 break;
 813         case SS_CONNECTED:
 814                 caif_assert(sk->sk_state == CAIF_CONNECTED ||
 815                                 sk->sk_state == CAIF_DISCONNECTED);
 816                 if (sk->sk_shutdown & SHUTDOWN_MASK) {
 817                         /* Allow re-connect after SHUTDOWN_IND */
 818                         caif_disconnect_client(sock_net(sk), &cf_sk->layer);
 819                         caif_free_client(&cf_sk->layer);
 820                         break;
 821                 }
 822                 /* No reconnect on a seqpacket socket */
 823                 err = -EISCONN;
 824                 goto out;
 825         case SS_DISCONNECTING:
 826         case SS_FREE:
 827                 caif_assert(1); /*Should never happen */
 828                 break;
 829         }
 830         sk->sk_state = CAIF_DISCONNECTED;
 831         sock->state = SS_UNCONNECTED;
 832         sk_stream_kill_queues(&cf_sk->sk);
 833
 834         err = -EINVAL;
 835         if (addr_len != sizeof(struct sockaddr_caif))
 836                 goto out;
 837
 838         memcpy(&cf_sk->conn_req.sockaddr, uaddr,
 839                 sizeof(struct sockaddr_caif));
 840
 841         /* Move to connecting socket, start sending Connect Requests */
 842         sock->state = SS_CONNECTING;
 843         sk->sk_state = CAIF_CONNECTING;
 844
 845         /* Check priority value comming from socket */
 846         /* if priority value is out of range it will be ajusted */
 847         if (cf_sk->sk.sk_priority > CAIF_PRIO_MAX)
 848                 cf_sk->conn_req.priority = CAIF_PRIO_MAX;
 849         else if (cf_sk->sk.sk_priority < CAIF_PRIO_MIN)
 850                 cf_sk->conn_req.priority = CAIF_PRIO_MIN;
 851         else
 852                 cf_sk->conn_req.priority = cf_sk->sk.sk_priority;
 853
 854         /*ifindex = id of the interface.*/
 855         cf_sk->conn_req.ifindex = cf_sk->sk.sk_bound_dev_if;
 856
 857         dbfs_atomic_inc(&cnt.num_connect_req);
 858         cf_sk->layer.receive = caif_sktrecv_cb;
 859
 860         err = caif_connect_client(sock_net(sk), &cf_sk->conn_req,
 861                                 &cf_sk->layer, &ifindex, &headroom, &tailroom);
 862
 863         if (err < 0) {
 864                 cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
 865                 cf_sk->sk.sk_state = CAIF_DISCONNECTED;
 866                 goto out;
 867         }
 868
 869         err = -ENODEV;
 870         rcu_read_lock();
 871         dev = dev_get_by_index_rcu(sock_net(sk), ifindex);
 872         if (!dev) {
 873                 rcu_read_unlock();
 874                 goto out;
 875         }
 876         cf_sk->headroom = LL_RESERVED_SPACE_EXTRA(dev, headroom);
 877         mtu = dev->mtu;
 878         rcu_read_unlock();
 879
 880         cf_sk->tailroom = tailroom;
 881         cf_sk->maxframe = mtu - (headroom + tailroom);
 882         if (cf_sk->maxframe < 1) {
 883                 pr_warn("CAIF Interface MTU too small (%d)\n", dev->mtu);
 884                 err = -ENODEV;
 885                 goto out;
 886         }
 887
 888         err = -EINPROGRESS;
 889 wait_connect:
 890
 891         if (sk->sk_state != CAIF_CONNECTED && (flags & O_NONBLOCK))
 892                 goto out;
 893
 894         timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
 895
 896         release_sock(sk);
 897         err = -ERESTARTSYS;
 898         timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
 899                         sk->sk_state != CAIF_CONNECTING,
 900                         timeo);
 901         lock_sock(sk);
 902         if (timeo < 0)
 903                 goto out; /* -ERESTARTSYS */
 904
 905         err = -ETIMEDOUT;
 906         if (timeo == 0 && sk->sk_state != CAIF_CONNECTED)
 907                 goto out;
 908         if (sk->sk_state != CAIF_CONNECTED) {
 909                 sock->state = SS_UNCONNECTED;
 910                 err = sock_error(sk);
 911                 if (!err)
 912                         err = -ECONNREFUSED;
 913                 goto out;
 914         }
 915         sock->state = SS_CONNECTED;
 916         err = 0;
 917 out:
 918         release_sock(sk);
 919         return err;
 920 }
 921
 922 /*
 923  * caif_release() - Disconnect a CAIF Socket
 924  * Copied and modified af_irda.c:irda_release().
 925  */
 926 static int caif_release(struct socket *sock)
 927 {
 928         struct sock *sk = sock->sk;
 929         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
 930
 931         if (!sk)
 932                 return 0;
 933
 934         set_tx_flow_off(cf_sk);
 935
 936         /*
 937          * Ensure that packets are not queued after this point in time.
 938          * caif_queue_rcv_skb checks SOCK_DEAD holding the queue lock,
 939          * this ensures no packets when sock is dead.
 940          */
 941         spin_lock_bh(&sk->sk_receive_queue.lock);
 942         sock_set_flag(sk, SOCK_DEAD);
 943         spin_unlock_bh(&sk->sk_receive_queue.lock);
 944         sock->sk = NULL;
 945
 946         dbfs_atomic_inc(&cnt.num_disconnect);
 947
 948         WARN_ON(IS_ERR(cf_sk->debugfs_socket_dir));
 949         if (cf_sk->debugfs_socket_dir != NULL)
 950                 debugfs_remove_recursive(cf_sk->debugfs_socket_dir);
 951
 952         lock_sock(&(cf_sk->sk));
 953         sk->sk_state = CAIF_DISCONNECTED;
 954         sk->sk_shutdown = SHUTDOWN_MASK;
 955
 956         caif_disconnect_client(sock_net(sk), &cf_sk->layer);
 957         cf_sk->sk.sk_socket->state = SS_DISCONNECTING;
 958         wake_up_interruptible_poll(sk_sleep(sk), POLLERR|POLLHUP);
 959
 960         sock_orphan(sk);
 961         sk_stream_kill_queues(&cf_sk->sk);
 962         release_sock(sk);
 963         sock_put(sk);
 964         return 0;
 965 }
 966
 967 /* Copied from af_unix.c:unix_poll(), added CAIF tx_flow handling */
 968 static unsigned int caif_poll(struct file *file,
 969                                 struct socket *sock, poll_table *wait)
 970 {
 971         struct sock *sk = sock->sk;
 972         unsigned int mask;
 973         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
 974
 975         sock_poll_wait(file, sk_sleep(sk), wait);
 976         mask = 0;
 977
 978         /* exceptional events? */
 979         if (sk->sk_err)
 980                 mask |= POLLERR;
 981         if (sk->sk_shutdown == SHUTDOWN_MASK)
 982                 mask |= POLLHUP;
 983         if (sk->sk_shutdown & RCV_SHUTDOWN)
 984                 mask |= POLLRDHUP;
 985
 986         /* readable? */
 987         if (!skb_queue_empty(&sk->sk_receive_queue) ||
 988                 (sk->sk_shutdown & RCV_SHUTDOWN))
 989                 mask |= POLLIN | POLLRDNORM;
 990
 991         /*
 992          * we set writable also when the other side has shut down the
 993          * connection. This prevents stuck sockets.
 994          */
 995         if (sock_writeable(sk) && tx_flow_is_on(cf_sk))
 996                 mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
 997
 998         return mask;
 999 }
1000
1001 static const struct proto_ops caif_seqpacket_ops = {
1002         .family = PF_CAIF,
1003         .owner = THIS_MODULE,
1004         .release = caif_release,
1005         .bind = sock_no_bind,
1006         .connect = caif_connect,
1007         .socketpair = sock_no_socketpair,
1008         .accept = sock_no_accept,
1009         .getname = sock_no_getname,
1010         .poll = caif_poll,
1011         .ioctl = sock_no_ioctl,
1012         .listen = sock_no_listen,
1013         .shutdown = sock_no_shutdown,
1014         .setsockopt = setsockopt,
1015         .getsockopt = sock_no_getsockopt,
1016         .sendmsg = caif_seqpkt_sendmsg,
1017         .recvmsg = caif_seqpkt_recvmsg,
1018         .mmap = sock_no_mmap,
1019         .sendpage = sock_no_sendpage,
1020 };
1021
1022 static const struct proto_ops caif_stream_ops = {
1023         .family = PF_CAIF,
1024         .owner = THIS_MODULE,
1025         .release = caif_release,
1026         .bind = sock_no_bind,
1027         .connect = caif_connect,
1028         .socketpair = sock_no_socketpair,
1029         .accept = sock_no_accept,
1030         .getname = sock_no_getname,
1031         .poll = caif_poll,
1032         .ioctl = sock_no_ioctl,
1033         .listen = sock_no_listen,
1034         .shutdown = sock_no_shutdown,
1035         .setsockopt = setsockopt,
1036         .getsockopt = sock_no_getsockopt,
1037         .sendmsg = caif_stream_sendmsg,
1038         .recvmsg = caif_stream_recvmsg,
1039         .mmap = sock_no_mmap,
1040         .sendpage = sock_no_sendpage,
1041 };
1042
1043 /* This function is called when a socket is finally destroyed. */
1044 static void caif_sock_destructor(struct sock *sk)
1045 {
1046         struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
1047         caif_assert(!atomic_read(&sk->sk_wmem_alloc));
1048         caif_assert(sk_unhashed(sk));
1049         caif_assert(!sk->sk_socket);
1050         if (!sock_flag(sk, SOCK_DEAD)) {
1051                 pr_debug("Attempt to release alive CAIF socket: %p\n", sk);
1052                 return;
1053         }
1054         sk_stream_kill_queues(&cf_sk->sk);
1055         dbfs_atomic_dec(&cnt.caif_nr_socks);
1056         caif_free_client(&cf_sk->layer);
1057 }
1058
1059 static int caif_create(struct net *net, struct socket *sock, int protocol,
1060                         int kern)
1061 {
1062         int num;
1063         struct sock *sk = NULL;
1064         struct caifsock *cf_sk = NULL;
1065         static struct proto prot = {.name = "PF_CAIF",
1066                 .owner = THIS_MODULE,
1067                 .obj_size = sizeof(struct caifsock),
1068         };
1069
1070         if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN))
1071                 return -EPERM;
1072         /*
1073          * The sock->type specifies the socket type to use.
1074          * The CAIF socket is a packet stream in the sense
1075          * that it is packet based. CAIF trusts the reliability
1076          * of the link, no resending is implemented.
1077          */
1078         if (sock->type == SOCK_SEQPACKET)
1079                 sock->ops = &caif_seqpacket_ops;
1080         else if (sock->type == SOCK_STREAM)
1081                 sock->ops = &caif_stream_ops;
1082         else
1083                 return -ESOCKTNOSUPPORT;
1084
1085         if (protocol < 0 || protocol >= CAIFPROTO_MAX)
1086                 return -EPROTONOSUPPORT;
1087         /*
1088          * Set the socket state to unconnected.  The socket state
1089          * is really not used at all in the net/core or socket.c but the
1090          * initialization makes sure that sock->state is not uninitialized.
1091          */
1092         sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot);
1093         if (!sk)
1094                 return -ENOMEM;
1095
1096         cf_sk = container_of(sk, struct caifsock, sk);
1097
1098         /* Store the protocol */
1099         sk->sk_protocol = (unsigned char) protocol;
1100
1101         /*
1102          * Lock in order to try to stop someone from opening the socket
1103          * too early.
1104          */
1105         lock_sock(&(cf_sk->sk));
1106
1107         /* Initialize the nozero default sock structure data. */
1108         sock_init_data(sock, sk);
1109         sk->sk_destruct = caif_sock_destructor;
1110
1111         mutex_init(&cf_sk->readlock); /* single task reading lock */
1112         cf_sk->layer.ctrlcmd = caif_ctrl_cb;
1113         cf_sk->sk.sk_socket->state = SS_UNCONNECTED;
1114         cf_sk->sk.sk_state = CAIF_DISCONNECTED;
1115
1116         set_tx_flow_off(cf_sk);
1117         set_rx_flow_on(cf_sk);
1118
1119         /* Set default options on configuration */
1120         cf_sk->sk.sk_priority = CAIF_PRIO_NORMAL;
1121         cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY;
1122         cf_sk->conn_req.protocol = protocol;
1123         /* Increase the number of sockets created. */
1124         dbfs_atomic_inc(&cnt.caif_nr_socks);
1125         num = dbfs_atomic_inc(&cnt.caif_sock_create);
1126 #ifdef CONFIG_DEBUG_FS
1127         if (!IS_ERR(debugfsdir)) {
1128
1129                 /* Fill in some information concerning the misc socket. */
1130                 snprintf(cf_sk->name, sizeof(cf_sk->name), "cfsk%d", num);
1131
1132                 cf_sk->debugfs_socket_dir =
1133                         debugfs_create_dir(cf_sk->name, debugfsdir);
1134
1135                 debugfs_create_u32("sk_state", S_IRUSR | S_IWUSR,
1136                                 cf_sk->debugfs_socket_dir,
1137                                 (u32 *) &cf_sk->sk.sk_state);
1138                 debugfs_create_u32("flow_state", S_IRUSR | S_IWUSR,
1139                                 cf_sk->debugfs_socket_dir, &cf_sk->flow_state);
1140                 debugfs_create_u32("sk_rmem_alloc", S_IRUSR | S_IWUSR,
1141                                 cf_sk->debugfs_socket_dir,
1142                                 (u32 *) &cf_sk->sk.sk_rmem_alloc);
1143                 debugfs_create_u32("sk_wmem_alloc", S_IRUSR | S_IWUSR,
1144                                 cf_sk->debugfs_socket_dir,
1145                                 (u32 *) &cf_sk->sk.sk_wmem_alloc);
1146                 debugfs_create_u32("identity", S_IRUSR | S_IWUSR,
1147                                 cf_sk->debugfs_socket_dir,
1148                                 (u32 *) &cf_sk->layer.id);
1149         }
1150 #endif
1151         release_sock(&cf_sk->sk);
1152         return 0;
1153 }
1154
1155
1156 static struct net_proto_family caif_family_ops = {
1157         .family = PF_CAIF,
1158         .create = caif_create,
1159         .owner = THIS_MODULE,
1160 };
1161
1162 static int af_caif_init(void)
1163 {
1164         int err = sock_register(&caif_family_ops);
1165         if (!err)
1166                 return err;
1167         return 0;
1168 }
1169
1170 static int __init caif_sktinit_module(void)
1171 {
1172 #ifdef CONFIG_DEBUG_FS
1173         debugfsdir = debugfs_create_dir("caif_sk", NULL);
1174         if (!IS_ERR(debugfsdir)) {
1175                 debugfs_create_u32("num_sockets", S_IRUSR | S_IWUSR,
1176                                 debugfsdir,
1177                                 (u32 *) &cnt.caif_nr_socks);
1178                 debugfs_create_u32("num_create", S_IRUSR | S_IWUSR,
1179                                 debugfsdir,
1180                                 (u32 *) &cnt.caif_sock_create);
1181                 debugfs_create_u32("num_connect_req", S_IRUSR | S_IWUSR,
1182                                 debugfsdir,
1183                                 (u32 *) &cnt.num_connect_req);
1184                 debugfs_create_u32("num_connect_resp", S_IRUSR | S_IWUSR,
1185                                 debugfsdir,
1186                                 (u32 *) &cnt.num_connect_resp);
1187                 debugfs_create_u32("num_connect_fail_resp", S_IRUSR | S_IWUSR,
1188                                 debugfsdir,
1189                                 (u32 *) &cnt.num_connect_fail_resp);
1190                 debugfs_create_u32("num_disconnect", S_IRUSR | S_IWUSR,
1191                                 debugfsdir,
1192                                 (u32 *) &cnt.num_disconnect);
1193                 debugfs_create_u32("num_remote_shutdown_ind",
1194                                 S_IRUSR | S_IWUSR, debugfsdir,
1195                                 (u32 *) &cnt.num_remote_shutdown_ind);
1196                 debugfs_create_u32("num_tx_flow_off_ind", S_IRUSR | S_IWUSR,
1197                                 debugfsdir,
1198                                 (u32 *) &cnt.num_tx_flow_off_ind);
1199                 debugfs_create_u32("num_tx_flow_on_ind", S_IRUSR | S_IWUSR,
1200                                 debugfsdir,
1201                                 (u32 *) &cnt.num_tx_flow_on_ind);
1202                 debugfs_create_u32("num_rx_flow_off", S_IRUSR | S_IWUSR,
1203                                 debugfsdir,
1204                                 (u32 *) &cnt.num_rx_flow_off);
1205                 debugfs_create_u32("num_rx_flow_on", S_IRUSR | S_IWUSR,
1206                                 debugfsdir,
1207                                 (u32 *) &cnt.num_rx_flow_on);
1208         }
1209 #endif
1210         return af_caif_init();
1211 }
1212
1213 static void __exit caif_sktexit_module(void)
1214 {
1215         sock_unregister(PF_CAIF);
1216         if (debugfsdir != NULL)
1217                 debugfs_remove_recursive(debugfsdir);
1218 }
1219 module_init(caif_sktinit_module);
1220 module_exit(caif_sktexit_module);