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