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); 1221