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