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