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 kfree_skb(skb); 544 return -EINVAL; 545 } 546 547 return cf_sk->layer.dn->transmit(cf_sk->layer.dn, pkt); 548 } 549 550 /* Copied from af_unix:unix_dgram_sendmsg, and adapted to CAIF */ 551 static int caif_seqpkt_sendmsg(struct kiocb *kiocb, struct socket *sock, 552 struct msghdr *msg, size_t len) 553 { 554 struct sock *sk = sock->sk; 555 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 556 int buffer_size; 557 int ret = 0; 558 struct sk_buff *skb = NULL; 559 int noblock; 560 long timeo; 561 caif_assert(cf_sk); 562 ret = sock_error(sk); 563 if (ret) 564 goto err; 565 566 ret = -EOPNOTSUPP; 567 if (msg->msg_flags&MSG_OOB) 568 goto err; 569 570 ret = -EOPNOTSUPP; 571 if (msg->msg_namelen) 572 goto err; 573 574 ret = -EINVAL; 575 if (unlikely(msg->msg_iov->iov_base == NULL)) 576 goto err; 577 noblock = msg->msg_flags & MSG_DONTWAIT; 578 579 timeo = sock_sndtimeo(sk, noblock); 580 timeo = caif_wait_for_flow_on(container_of(sk, struct caifsock, sk), 581 1, timeo, &ret); 582 583 if (ret) 584 goto err; 585 ret = -EPIPE; 586 if (cf_sk->sk.sk_state != CAIF_CONNECTED || 587 sock_flag(sk, SOCK_DEAD) || 588 (sk->sk_shutdown & RCV_SHUTDOWN)) 589 goto err; 590 591 /* Error if trying to write more than maximum frame size. */ 592 ret = -EMSGSIZE; 593 if (len > cf_sk->maxframe && cf_sk->sk.sk_protocol != CAIFPROTO_RFM) 594 goto err; 595 596 buffer_size = len + cf_sk->headroom + cf_sk->tailroom; 597 598 ret = -ENOMEM; 599 skb = sock_alloc_send_skb(sk, buffer_size, noblock, &ret); 600 601 if (!skb || skb_tailroom(skb) < buffer_size) 602 goto err; 603 604 skb_reserve(skb, cf_sk->headroom); 605 606 ret = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); 607 608 if (ret) 609 goto err; 610 ret = transmit_skb(skb, cf_sk, noblock, timeo); 611 if (ret < 0) 612 /* skb is already freed */ 613 return ret; 614 615 return len; 616 err: 617 kfree_skb(skb); 618 return ret; 619 } 620 621 /* 622 * Copied from unix_stream_sendmsg and adapted to CAIF: 623 * Changed removed permission handling and added waiting for flow on 624 * and other minor adaptations. 625 */ 626 static int caif_stream_sendmsg(struct kiocb *kiocb, struct socket *sock, 627 struct msghdr *msg, size_t len) 628 { 629 struct sock *sk = sock->sk; 630 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 631 int err, size; 632 struct sk_buff *skb; 633 int sent = 0; 634 long timeo; 635 636 err = -EOPNOTSUPP; 637 if (unlikely(msg->msg_flags&MSG_OOB)) 638 goto out_err; 639 640 if (unlikely(msg->msg_namelen)) 641 goto out_err; 642 643 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); 644 timeo = caif_wait_for_flow_on(cf_sk, 1, timeo, &err); 645 646 if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN)) 647 goto pipe_err; 648 649 while (sent < len) { 650 651 size = len-sent; 652 653 if (size > cf_sk->maxframe) 654 size = cf_sk->maxframe; 655 656 /* If size is more than half of sndbuf, chop up message */ 657 if (size > ((sk->sk_sndbuf >> 1) - 64)) 658 size = (sk->sk_sndbuf >> 1) - 64; 659 660 if (size > SKB_MAX_ALLOC) 661 size = SKB_MAX_ALLOC; 662 663 skb = sock_alloc_send_skb(sk, 664 size + cf_sk->headroom + 665 cf_sk->tailroom, 666 msg->msg_flags&MSG_DONTWAIT, 667 &err); 668 if (skb == NULL) 669 goto out_err; 670 671 skb_reserve(skb, cf_sk->headroom); 672 /* 673 * If you pass two values to the sock_alloc_send_skb 674 * it tries to grab the large buffer with GFP_NOFS 675 * (which can fail easily), and if it fails grab the 676 * fallback size buffer which is under a page and will 677 * succeed. [Alan] 678 */ 679 size = min_t(int, size, skb_tailroom(skb)); 680 681 err = memcpy_fromiovec(skb_put(skb, size), msg->msg_iov, size); 682 if (err) { 683 kfree_skb(skb); 684 goto out_err; 685 } 686 err = transmit_skb(skb, cf_sk, 687 msg->msg_flags&MSG_DONTWAIT, timeo); 688 if (err < 0) 689 /* skb is already freed */ 690 goto pipe_err; 691 692 sent += size; 693 } 694 695 return sent; 696 697 pipe_err: 698 if (sent == 0 && !(msg->msg_flags&MSG_NOSIGNAL)) 699 send_sig(SIGPIPE, current, 0); 700 err = -EPIPE; 701 out_err: 702 return sent ? : err; 703 } 704 705 static int setsockopt(struct socket *sock, 706 int lvl, int opt, char __user *ov, unsigned int ol) 707 { 708 struct sock *sk = sock->sk; 709 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 710 int linksel; 711 712 if (cf_sk->sk.sk_socket->state != SS_UNCONNECTED) 713 return -ENOPROTOOPT; 714 715 switch (opt) { 716 case CAIFSO_LINK_SELECT: 717 if (ol < sizeof(int)) 718 return -EINVAL; 719 if (lvl != SOL_CAIF) 720 goto bad_sol; 721 if (copy_from_user(&linksel, ov, sizeof(int))) 722 return -EINVAL; 723 lock_sock(&(cf_sk->sk)); 724 cf_sk->conn_req.link_selector = linksel; 725 release_sock(&cf_sk->sk); 726 return 0; 727 728 case CAIFSO_REQ_PARAM: 729 if (lvl != SOL_CAIF) 730 goto bad_sol; 731 if (cf_sk->sk.sk_protocol != CAIFPROTO_UTIL) 732 return -ENOPROTOOPT; 733 lock_sock(&(cf_sk->sk)); 734 if (ol > sizeof(cf_sk->conn_req.param.data) || 735 copy_from_user(&cf_sk->conn_req.param.data, ov, ol)) { 736 release_sock(&cf_sk->sk); 737 return -EINVAL; 738 } 739 cf_sk->conn_req.param.size = ol; 740 release_sock(&cf_sk->sk); 741 return 0; 742 743 default: 744 return -ENOPROTOOPT; 745 } 746 747 return 0; 748 bad_sol: 749 return -ENOPROTOOPT; 750 751 } 752 753 /* 754 * caif_connect() - Connect a CAIF Socket 755 * Copied and modified af_irda.c:irda_connect(). 756 * 757 * Note : by consulting "errno", the user space caller may learn the cause 758 * of the failure. Most of them are visible in the function, others may come 759 * from subroutines called and are listed here : 760 * o -EAFNOSUPPORT: bad socket family or type. 761 * o -ESOCKTNOSUPPORT: bad socket type or protocol 762 * o -EINVAL: bad socket address, or CAIF link type 763 * o -ECONNREFUSED: remote end refused the connection. 764 * o -EINPROGRESS: connect request sent but timed out (or non-blocking) 765 * o -EISCONN: already connected. 766 * o -ETIMEDOUT: Connection timed out (send timeout) 767 * o -ENODEV: No link layer to send request 768 * o -ECONNRESET: Received Shutdown indication or lost link layer 769 * o -ENOMEM: Out of memory 770 * 771 * State Strategy: 772 * o sk_state: holds the CAIF_* protocol state, it's updated by 773 * caif_ctrl_cb. 774 * o sock->state: holds the SS_* socket state and is updated by connect and 775 * disconnect. 776 */ 777 static int caif_connect(struct socket *sock, struct sockaddr *uaddr, 778 int addr_len, int flags) 779 { 780 struct sock *sk = sock->sk; 781 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 782 long timeo; 783 int err; 784 int ifindex, headroom, tailroom; 785 unsigned int mtu; 786 struct net_device *dev; 787 788 lock_sock(sk); 789 790 err = -EAFNOSUPPORT; 791 if (uaddr->sa_family != AF_CAIF) 792 goto out; 793 794 switch (sock->state) { 795 case SS_UNCONNECTED: 796 /* Normal case, a fresh connect */ 797 caif_assert(sk->sk_state == CAIF_DISCONNECTED); 798 break; 799 case SS_CONNECTING: 800 switch (sk->sk_state) { 801 case CAIF_CONNECTED: 802 sock->state = SS_CONNECTED; 803 err = -EISCONN; 804 goto out; 805 case CAIF_DISCONNECTED: 806 /* Reconnect allowed */ 807 break; 808 case CAIF_CONNECTING: 809 err = -EALREADY; 810 if (flags & O_NONBLOCK) 811 goto out; 812 goto wait_connect; 813 } 814 break; 815 case SS_CONNECTED: 816 caif_assert(sk->sk_state == CAIF_CONNECTED || 817 sk->sk_state == CAIF_DISCONNECTED); 818 if (sk->sk_shutdown & SHUTDOWN_MASK) { 819 /* Allow re-connect after SHUTDOWN_IND */ 820 caif_disconnect_client(sock_net(sk), &cf_sk->layer); 821 caif_free_client(&cf_sk->layer); 822 break; 823 } 824 /* No reconnect on a seqpacket socket */ 825 err = -EISCONN; 826 goto out; 827 case SS_DISCONNECTING: 828 case SS_FREE: 829 caif_assert(1); /*Should never happen */ 830 break; 831 } 832 sk->sk_state = CAIF_DISCONNECTED; 833 sock->state = SS_UNCONNECTED; 834 sk_stream_kill_queues(&cf_sk->sk); 835 836 err = -EINVAL; 837 if (addr_len != sizeof(struct sockaddr_caif)) 838 goto out; 839 840 memcpy(&cf_sk->conn_req.sockaddr, uaddr, 841 sizeof(struct sockaddr_caif)); 842 843 /* Move to connecting socket, start sending Connect Requests */ 844 sock->state = SS_CONNECTING; 845 sk->sk_state = CAIF_CONNECTING; 846 847 /* Check priority value comming from socket */ 848 /* if priority value is out of range it will be ajusted */ 849 if (cf_sk->sk.sk_priority > CAIF_PRIO_MAX) 850 cf_sk->conn_req.priority = CAIF_PRIO_MAX; 851 else if (cf_sk->sk.sk_priority < CAIF_PRIO_MIN) 852 cf_sk->conn_req.priority = CAIF_PRIO_MIN; 853 else 854 cf_sk->conn_req.priority = cf_sk->sk.sk_priority; 855 856 /*ifindex = id of the interface.*/ 857 cf_sk->conn_req.ifindex = cf_sk->sk.sk_bound_dev_if; 858 859 dbfs_atomic_inc(&cnt.num_connect_req); 860 cf_sk->layer.receive = caif_sktrecv_cb; 861 862 err = caif_connect_client(sock_net(sk), &cf_sk->conn_req, 863 &cf_sk->layer, &ifindex, &headroom, &tailroom); 864 865 if (err < 0) { 866 cf_sk->sk.sk_socket->state = SS_UNCONNECTED; 867 cf_sk->sk.sk_state = CAIF_DISCONNECTED; 868 goto out; 869 } 870 871 err = -ENODEV; 872 rcu_read_lock(); 873 dev = dev_get_by_index_rcu(sock_net(sk), ifindex); 874 if (!dev) { 875 rcu_read_unlock(); 876 goto out; 877 } 878 cf_sk->headroom = LL_RESERVED_SPACE_EXTRA(dev, headroom); 879 mtu = dev->mtu; 880 rcu_read_unlock(); 881 882 cf_sk->tailroom = tailroom; 883 cf_sk->maxframe = mtu - (headroom + tailroom); 884 if (cf_sk->maxframe < 1) { 885 pr_warn("CAIF Interface MTU too small (%d)\n", dev->mtu); 886 err = -ENODEV; 887 goto out; 888 } 889 890 err = -EINPROGRESS; 891 wait_connect: 892 893 if (sk->sk_state != CAIF_CONNECTED && (flags & O_NONBLOCK)) 894 goto out; 895 896 timeo = sock_sndtimeo(sk, flags & O_NONBLOCK); 897 898 release_sock(sk); 899 err = -ERESTARTSYS; 900 timeo = wait_event_interruptible_timeout(*sk_sleep(sk), 901 sk->sk_state != CAIF_CONNECTING, 902 timeo); 903 lock_sock(sk); 904 if (timeo < 0) 905 goto out; /* -ERESTARTSYS */ 906 907 err = -ETIMEDOUT; 908 if (timeo == 0 && sk->sk_state != CAIF_CONNECTED) 909 goto out; 910 if (sk->sk_state != CAIF_CONNECTED) { 911 sock->state = SS_UNCONNECTED; 912 err = sock_error(sk); 913 if (!err) 914 err = -ECONNREFUSED; 915 goto out; 916 } 917 sock->state = SS_CONNECTED; 918 err = 0; 919 out: 920 release_sock(sk); 921 return err; 922 } 923 924 /* 925 * caif_release() - Disconnect a CAIF Socket 926 * Copied and modified af_irda.c:irda_release(). 927 */ 928 static int caif_release(struct socket *sock) 929 { 930 struct sock *sk = sock->sk; 931 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 932 933 if (!sk) 934 return 0; 935 936 set_tx_flow_off(cf_sk); 937 938 /* 939 * Ensure that packets are not queued after this point in time. 940 * caif_queue_rcv_skb checks SOCK_DEAD holding the queue lock, 941 * this ensures no packets when sock is dead. 942 */ 943 spin_lock_bh(&sk->sk_receive_queue.lock); 944 sock_set_flag(sk, SOCK_DEAD); 945 spin_unlock_bh(&sk->sk_receive_queue.lock); 946 sock->sk = NULL; 947 948 dbfs_atomic_inc(&cnt.num_disconnect); 949 950 WARN_ON(IS_ERR(cf_sk->debugfs_socket_dir)); 951 if (cf_sk->debugfs_socket_dir != NULL) 952 debugfs_remove_recursive(cf_sk->debugfs_socket_dir); 953 954 lock_sock(&(cf_sk->sk)); 955 sk->sk_state = CAIF_DISCONNECTED; 956 sk->sk_shutdown = SHUTDOWN_MASK; 957 958 caif_disconnect_client(sock_net(sk), &cf_sk->layer); 959 cf_sk->sk.sk_socket->state = SS_DISCONNECTING; 960 wake_up_interruptible_poll(sk_sleep(sk), POLLERR|POLLHUP); 961 962 sock_orphan(sk); 963 sk_stream_kill_queues(&cf_sk->sk); 964 release_sock(sk); 965 sock_put(sk); 966 return 0; 967 } 968 969 /* Copied from af_unix.c:unix_poll(), added CAIF tx_flow handling */ 970 static unsigned int caif_poll(struct file *file, 971 struct socket *sock, poll_table *wait) 972 { 973 struct sock *sk = sock->sk; 974 unsigned int mask; 975 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 976 977 sock_poll_wait(file, sk_sleep(sk), wait); 978 mask = 0; 979 980 /* exceptional events? */ 981 if (sk->sk_err) 982 mask |= POLLERR; 983 if (sk->sk_shutdown == SHUTDOWN_MASK) 984 mask |= POLLHUP; 985 if (sk->sk_shutdown & RCV_SHUTDOWN) 986 mask |= POLLRDHUP; 987 988 /* readable? */ 989 if (!skb_queue_empty(&sk->sk_receive_queue) || 990 (sk->sk_shutdown & RCV_SHUTDOWN)) 991 mask |= POLLIN | POLLRDNORM; 992 993 /* 994 * we set writable also when the other side has shut down the 995 * connection. This prevents stuck sockets. 996 */ 997 if (sock_writeable(sk) && tx_flow_is_on(cf_sk)) 998 mask |= POLLOUT | POLLWRNORM | POLLWRBAND; 999 1000 return mask; 1001 } 1002 1003 static const struct proto_ops caif_seqpacket_ops = { 1004 .family = PF_CAIF, 1005 .owner = THIS_MODULE, 1006 .release = caif_release, 1007 .bind = sock_no_bind, 1008 .connect = caif_connect, 1009 .socketpair = sock_no_socketpair, 1010 .accept = sock_no_accept, 1011 .getname = sock_no_getname, 1012 .poll = caif_poll, 1013 .ioctl = sock_no_ioctl, 1014 .listen = sock_no_listen, 1015 .shutdown = sock_no_shutdown, 1016 .setsockopt = setsockopt, 1017 .getsockopt = sock_no_getsockopt, 1018 .sendmsg = caif_seqpkt_sendmsg, 1019 .recvmsg = caif_seqpkt_recvmsg, 1020 .mmap = sock_no_mmap, 1021 .sendpage = sock_no_sendpage, 1022 }; 1023 1024 static const struct proto_ops caif_stream_ops = { 1025 .family = PF_CAIF, 1026 .owner = THIS_MODULE, 1027 .release = caif_release, 1028 .bind = sock_no_bind, 1029 .connect = caif_connect, 1030 .socketpair = sock_no_socketpair, 1031 .accept = sock_no_accept, 1032 .getname = sock_no_getname, 1033 .poll = caif_poll, 1034 .ioctl = sock_no_ioctl, 1035 .listen = sock_no_listen, 1036 .shutdown = sock_no_shutdown, 1037 .setsockopt = setsockopt, 1038 .getsockopt = sock_no_getsockopt, 1039 .sendmsg = caif_stream_sendmsg, 1040 .recvmsg = caif_stream_recvmsg, 1041 .mmap = sock_no_mmap, 1042 .sendpage = sock_no_sendpage, 1043 }; 1044 1045 /* This function is called when a socket is finally destroyed. */ 1046 static void caif_sock_destructor(struct sock *sk) 1047 { 1048 struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); 1049 caif_assert(!atomic_read(&sk->sk_wmem_alloc)); 1050 caif_assert(sk_unhashed(sk)); 1051 caif_assert(!sk->sk_socket); 1052 if (!sock_flag(sk, SOCK_DEAD)) { 1053 pr_debug("Attempt to release alive CAIF socket: %p\n", sk); 1054 return; 1055 } 1056 sk_stream_kill_queues(&cf_sk->sk); 1057 dbfs_atomic_dec(&cnt.caif_nr_socks); 1058 caif_free_client(&cf_sk->layer); 1059 } 1060 1061 static int caif_create(struct net *net, struct socket *sock, int protocol, 1062 int kern) 1063 { 1064 int num; 1065 struct sock *sk = NULL; 1066 struct caifsock *cf_sk = NULL; 1067 static struct proto prot = {.name = "PF_CAIF", 1068 .owner = THIS_MODULE, 1069 .obj_size = sizeof(struct caifsock), 1070 }; 1071 1072 if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN)) 1073 return -EPERM; 1074 /* 1075 * The sock->type specifies the socket type to use. 1076 * The CAIF socket is a packet stream in the sense 1077 * that it is packet based. CAIF trusts the reliability 1078 * of the link, no resending is implemented. 1079 */ 1080 if (sock->type == SOCK_SEQPACKET) 1081 sock->ops = &caif_seqpacket_ops; 1082 else if (sock->type == SOCK_STREAM) 1083 sock->ops = &caif_stream_ops; 1084 else 1085 return -ESOCKTNOSUPPORT; 1086 1087 if (protocol < 0 || protocol >= CAIFPROTO_MAX) 1088 return -EPROTONOSUPPORT; 1089 /* 1090 * Set the socket state to unconnected. The socket state 1091 * is really not used at all in the net/core or socket.c but the 1092 * initialization makes sure that sock->state is not uninitialized. 1093 */ 1094 sk = sk_alloc(net, PF_CAIF, GFP_KERNEL, &prot); 1095 if (!sk) 1096 return -ENOMEM; 1097 1098 cf_sk = container_of(sk, struct caifsock, sk); 1099 1100 /* Store the protocol */ 1101 sk->sk_protocol = (unsigned char) protocol; 1102 1103 /* 1104 * Lock in order to try to stop someone from opening the socket 1105 * too early. 1106 */ 1107 lock_sock(&(cf_sk->sk)); 1108 1109 /* Initialize the nozero default sock structure data. */ 1110 sock_init_data(sock, sk); 1111 sk->sk_destruct = caif_sock_destructor; 1112 1113 mutex_init(&cf_sk->readlock); /* single task reading lock */ 1114 cf_sk->layer.ctrlcmd = caif_ctrl_cb; 1115 cf_sk->sk.sk_socket->state = SS_UNCONNECTED; 1116 cf_sk->sk.sk_state = CAIF_DISCONNECTED; 1117 1118 set_tx_flow_off(cf_sk); 1119 set_rx_flow_on(cf_sk); 1120 1121 /* Set default options on configuration */ 1122 cf_sk->sk.sk_priority = CAIF_PRIO_NORMAL; 1123 cf_sk->conn_req.link_selector = CAIF_LINK_LOW_LATENCY; 1124 cf_sk->conn_req.protocol = protocol; 1125 /* Increase the number of sockets created. */ 1126 dbfs_atomic_inc(&cnt.caif_nr_socks); 1127 num = dbfs_atomic_inc(&cnt.caif_sock_create); 1128 #ifdef CONFIG_DEBUG_FS 1129 if (!IS_ERR(debugfsdir)) { 1130 1131 /* Fill in some information concerning the misc socket. */ 1132 snprintf(cf_sk->name, sizeof(cf_sk->name), "cfsk%d", num); 1133 1134 cf_sk->debugfs_socket_dir = 1135 debugfs_create_dir(cf_sk->name, debugfsdir); 1136 1137 debugfs_create_u32("sk_state", S_IRUSR | S_IWUSR, 1138 cf_sk->debugfs_socket_dir, 1139 (u32 *) &cf_sk->sk.sk_state); 1140 debugfs_create_u32("flow_state", S_IRUSR | S_IWUSR, 1141 cf_sk->debugfs_socket_dir, &cf_sk->flow_state); 1142 debugfs_create_u32("sk_rmem_alloc", S_IRUSR | S_IWUSR, 1143 cf_sk->debugfs_socket_dir, 1144 (u32 *) &cf_sk->sk.sk_rmem_alloc); 1145 debugfs_create_u32("sk_wmem_alloc", S_IRUSR | S_IWUSR, 1146 cf_sk->debugfs_socket_dir, 1147 (u32 *) &cf_sk->sk.sk_wmem_alloc); 1148 debugfs_create_u32("identity", S_IRUSR | S_IWUSR, 1149 cf_sk->debugfs_socket_dir, 1150 (u32 *) &cf_sk->layer.id); 1151 } 1152 #endif 1153 release_sock(&cf_sk->sk); 1154 return 0; 1155 } 1156 1157 1158 static struct net_proto_family caif_family_ops = { 1159 .family = PF_CAIF, 1160 .create = caif_create, 1161 .owner = THIS_MODULE, 1162 }; 1163 1164 static int af_caif_init(void) 1165 { 1166 int err = sock_register(&caif_family_ops); 1167 if (!err) 1168 return err; 1169 return 0; 1170 } 1171 1172 static int __init caif_sktinit_module(void) 1173 { 1174 #ifdef CONFIG_DEBUG_FS 1175 debugfsdir = debugfs_create_dir("caif_sk", NULL); 1176 if (!IS_ERR(debugfsdir)) { 1177 debugfs_create_u32("num_sockets", S_IRUSR | S_IWUSR, 1178 debugfsdir, 1179 (u32 *) &cnt.caif_nr_socks); 1180 debugfs_create_u32("num_create", S_IRUSR | S_IWUSR, 1181 debugfsdir, 1182 (u32 *) &cnt.caif_sock_create); 1183 debugfs_create_u32("num_connect_req", S_IRUSR | S_IWUSR, 1184 debugfsdir, 1185 (u32 *) &cnt.num_connect_req); 1186 debugfs_create_u32("num_connect_resp", S_IRUSR | S_IWUSR, 1187 debugfsdir, 1188 (u32 *) &cnt.num_connect_resp); 1189 debugfs_create_u32("num_connect_fail_resp", S_IRUSR | S_IWUSR, 1190 debugfsdir, 1191 (u32 *) &cnt.num_connect_fail_resp); 1192 debugfs_create_u32("num_disconnect", S_IRUSR | S_IWUSR, 1193 debugfsdir, 1194 (u32 *) &cnt.num_disconnect); 1195 debugfs_create_u32("num_remote_shutdown_ind", 1196 S_IRUSR | S_IWUSR, debugfsdir, 1197 (u32 *) &cnt.num_remote_shutdown_ind); 1198 debugfs_create_u32("num_tx_flow_off_ind", S_IRUSR | S_IWUSR, 1199 debugfsdir, 1200 (u32 *) &cnt.num_tx_flow_off_ind); 1201 debugfs_create_u32("num_tx_flow_on_ind", S_IRUSR | S_IWUSR, 1202 debugfsdir, 1203 (u32 *) &cnt.num_tx_flow_on_ind); 1204 debugfs_create_u32("num_rx_flow_off", S_IRUSR | S_IWUSR, 1205 debugfsdir, 1206 (u32 *) &cnt.num_rx_flow_off); 1207 debugfs_create_u32("num_rx_flow_on", S_IRUSR | S_IWUSR, 1208 debugfsdir, 1209 (u32 *) &cnt.num_rx_flow_on); 1210 } 1211 #endif 1212 return af_caif_init(); 1213 } 1214 1215 static void __exit caif_sktexit_module(void) 1216 { 1217 sock_unregister(PF_CAIF); 1218 if (debugfsdir != NULL) 1219 debugfs_remove_recursive(debugfsdir); 1220 } 1221 module_init(caif_sktinit_module); 1222 module_exit(caif_sktexit_module); 1223